gcc/testsuite
[official-gcc.git] / gcc / varasm.c
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1 /* Output variables, constants and external declarations, for GNU compiler.
2 Copyright (C) 1987-2014 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
21 /* This file handles generation of all the assembler code
22 *except* the instructions of a function.
23 This includes declarations of variables and their initial values.
25 We also output the assembler code for constants stored in memory
26 and are responsible for combining constants with the same value. */
28 #include "config.h"
29 #include "system.h"
30 #include "coretypes.h"
31 #include "tm.h"
32 #include "rtl.h"
33 #include "tree.h"
34 #include "stor-layout.h"
35 #include "stringpool.h"
36 #include "gcc-symtab.h"
37 #include "varasm.h"
38 #include "flags.h"
39 #include "function.h"
40 #include "expr.h"
41 #include "hard-reg-set.h"
42 #include "regs.h"
43 #include "output.h"
44 #include "diagnostic-core.h"
45 #include "hashtab.h"
46 #include "ggc.h"
47 #include "langhooks.h"
48 #include "tm_p.h"
49 #include "debug.h"
50 #include "target.h"
51 #include "common/common-target.h"
52 #include "targhooks.h"
53 #include "cgraph.h"
54 #include "hash-set.h"
55 #include "asan.h"
56 #include "basic-block.h"
58 #ifdef XCOFF_DEBUGGING_INFO
59 #include "xcoffout.h" /* Needed for external data
60 declarations for e.g. AIX 4.x. */
61 #endif
63 /* The (assembler) name of the first globally-visible object output. */
64 extern GTY(()) const char *first_global_object_name;
65 extern GTY(()) const char *weak_global_object_name;
67 const char *first_global_object_name;
68 const char *weak_global_object_name;
70 struct addr_const;
71 struct constant_descriptor_rtx;
72 struct rtx_constant_pool;
74 #define n_deferred_constants (crtl->varasm.deferred_constants)
76 /* Number for making the label on the next
77 constant that is stored in memory. */
79 static GTY(()) int const_labelno;
81 /* Carry information from ASM_DECLARE_OBJECT_NAME
82 to ASM_FINISH_DECLARE_OBJECT. */
84 int size_directive_output;
86 /* The last decl for which assemble_variable was called,
87 if it did ASM_DECLARE_OBJECT_NAME.
88 If the last call to assemble_variable didn't do that,
89 this holds 0. */
91 tree last_assemble_variable_decl;
93 /* The following global variable indicates if the first basic block
94 in a function belongs to the cold partition or not. */
96 bool first_function_block_is_cold;
98 /* We give all constants their own alias set. Perhaps redundant with
99 MEM_READONLY_P, but pre-dates it. */
101 static alias_set_type const_alias_set;
103 /* Whether we saw any functions with no_split_stack. */
105 static bool saw_no_split_stack;
107 static const char *strip_reg_name (const char *);
108 static int contains_pointers_p (tree);
109 #ifdef ASM_OUTPUT_EXTERNAL
110 static bool incorporeal_function_p (tree);
111 #endif
112 static void decode_addr_const (tree, struct addr_const *);
113 static hashval_t const_desc_hash (const void *);
114 static int const_desc_eq (const void *, const void *);
115 static hashval_t const_hash_1 (const tree);
116 static int compare_constant (const tree, const tree);
117 static void output_constant_def_contents (rtx);
118 static void output_addressed_constants (tree);
119 static unsigned HOST_WIDE_INT output_constant (tree, unsigned HOST_WIDE_INT,
120 unsigned int);
121 static void globalize_decl (tree);
122 static bool decl_readonly_section_1 (enum section_category);
123 #ifdef BSS_SECTION_ASM_OP
124 #ifdef ASM_OUTPUT_ALIGNED_BSS
125 static void asm_output_aligned_bss (FILE *, tree, const char *,
126 unsigned HOST_WIDE_INT, int)
127 ATTRIBUTE_UNUSED;
128 #endif
129 #endif /* BSS_SECTION_ASM_OP */
130 static void mark_weak (tree);
131 static void output_constant_pool (const char *, tree);
133 /* Well-known sections, each one associated with some sort of *_ASM_OP. */
134 section *text_section;
135 section *data_section;
136 section *readonly_data_section;
137 section *sdata_section;
138 section *ctors_section;
139 section *dtors_section;
140 section *bss_section;
141 section *sbss_section;
143 /* Various forms of common section. All are guaranteed to be nonnull. */
144 section *tls_comm_section;
145 section *comm_section;
146 section *lcomm_section;
148 /* A SECTION_NOSWITCH section used for declaring global BSS variables.
149 May be null. */
150 section *bss_noswitch_section;
152 /* The section that holds the main exception table, when known. The section
153 is set either by the target's init_sections hook or by the first call to
154 switch_to_exception_section. */
155 section *exception_section;
157 /* The section that holds the DWARF2 frame unwind information, when known.
158 The section is set either by the target's init_sections hook or by the
159 first call to switch_to_eh_frame_section. */
160 section *eh_frame_section;
162 /* asm_out_file's current section. This is NULL if no section has yet
163 been selected or if we lose track of what the current section is. */
164 section *in_section;
166 /* True if code for the current function is currently being directed
167 at the cold section. */
168 bool in_cold_section_p;
170 /* A linked list of all the unnamed sections. */
171 static GTY(()) section *unnamed_sections;
173 /* Return a nonzero value if DECL has a section attribute. */
174 #define IN_NAMED_SECTION(DECL) \
175 ((TREE_CODE (DECL) == FUNCTION_DECL || TREE_CODE (DECL) == VAR_DECL) \
176 && DECL_SECTION_NAME (DECL) != NULL)
178 /* Hash table of named sections. */
179 static GTY((param_is (section))) htab_t section_htab;
181 /* A table of object_blocks, indexed by section. */
182 static GTY((param_is (struct object_block))) htab_t object_block_htab;
184 /* The next number to use for internal anchor labels. */
185 static GTY(()) int anchor_labelno;
187 /* A pool of constants that can be shared between functions. */
188 static GTY(()) struct rtx_constant_pool *shared_constant_pool;
190 /* Helper routines for maintaining section_htab. */
192 static int
193 section_entry_eq (const void *p1, const void *p2)
195 const section *old = (const section *) p1;
196 const char *new_name = (const char *) p2;
198 return strcmp (old->named.name, new_name) == 0;
201 static hashval_t
202 section_entry_hash (const void *p)
204 const section *old = (const section *) p;
205 return htab_hash_string (old->named.name);
208 /* Return a hash value for section SECT. */
210 static hashval_t
211 hash_section (section *sect)
213 if (sect->common.flags & SECTION_NAMED)
214 return htab_hash_string (sect->named.name);
215 return sect->common.flags;
218 /* Helper routines for maintaining object_block_htab. */
220 static int
221 object_block_entry_eq (const void *p1, const void *p2)
223 const struct object_block *old = (const struct object_block *) p1;
224 const section *new_section = (const section *) p2;
226 return old->sect == new_section;
229 static hashval_t
230 object_block_entry_hash (const void *p)
232 const struct object_block *old = (const struct object_block *) p;
233 return hash_section (old->sect);
236 /* Return a new unnamed section with the given fields. */
238 section *
239 get_unnamed_section (unsigned int flags, void (*callback) (const void *),
240 const void *data)
242 section *sect;
244 sect = ggc_alloc<section> ();
245 sect->unnamed.common.flags = flags | SECTION_UNNAMED;
246 sect->unnamed.callback = callback;
247 sect->unnamed.data = data;
248 sect->unnamed.next = unnamed_sections;
250 unnamed_sections = sect;
251 return sect;
254 /* Return a SECTION_NOSWITCH section with the given fields. */
256 static section *
257 get_noswitch_section (unsigned int flags, noswitch_section_callback callback)
259 section *sect;
261 sect = ggc_alloc<section> ();
262 sect->noswitch.common.flags = flags | SECTION_NOSWITCH;
263 sect->noswitch.callback = callback;
265 return sect;
268 /* Return the named section structure associated with NAME. Create
269 a new section with the given fields if no such structure exists. */
271 section *
272 get_section (const char *name, unsigned int flags, tree decl)
274 section *sect, **slot;
276 slot = (section **)
277 htab_find_slot_with_hash (section_htab, name,
278 htab_hash_string (name), INSERT);
279 flags |= SECTION_NAMED;
280 if (*slot == NULL)
282 sect = ggc_alloc<section> ();
283 sect->named.common.flags = flags;
284 sect->named.name = ggc_strdup (name);
285 sect->named.decl = decl;
286 *slot = sect;
288 else
290 sect = *slot;
291 if ((sect->common.flags & ~SECTION_DECLARED) != flags
292 && ((sect->common.flags | flags) & SECTION_OVERRIDE) == 0)
294 /* It is fine if one of the section flags is
295 SECTION_WRITE | SECTION_RELRO and the other has none of these
296 flags (i.e. read-only) in named sections and either the
297 section hasn't been declared yet or has been declared as writable.
298 In that case just make sure the resulting flags are
299 SECTION_WRITE | SECTION_RELRO, ie. writable only because of
300 relocations. */
301 if (((sect->common.flags ^ flags) & (SECTION_WRITE | SECTION_RELRO))
302 == (SECTION_WRITE | SECTION_RELRO)
303 && (sect->common.flags
304 & ~(SECTION_DECLARED | SECTION_WRITE | SECTION_RELRO))
305 == (flags & ~(SECTION_WRITE | SECTION_RELRO))
306 && ((sect->common.flags & SECTION_DECLARED) == 0
307 || (sect->common.flags & SECTION_WRITE)))
309 sect->common.flags |= (SECTION_WRITE | SECTION_RELRO);
310 return sect;
312 /* Sanity check user variables for flag changes. */
313 if (sect->named.decl != NULL
314 && DECL_P (sect->named.decl)
315 && decl != sect->named.decl)
317 if (decl != NULL && DECL_P (decl))
318 error ("%+D causes a section type conflict with %D",
319 decl, sect->named.decl);
320 else
321 error ("section type conflict with %D", sect->named.decl);
322 inform (DECL_SOURCE_LOCATION (sect->named.decl),
323 "%qD was declared here", sect->named.decl);
325 else if (decl != NULL && DECL_P (decl))
326 error ("%+D causes a section type conflict", decl);
327 else
328 error ("section type conflict");
329 /* Make sure we don't error about one section multiple times. */
330 sect->common.flags |= SECTION_OVERRIDE;
333 return sect;
336 /* Return true if the current compilation mode benefits from having
337 objects grouped into blocks. */
339 static bool
340 use_object_blocks_p (void)
342 return flag_section_anchors;
345 /* Return the object_block structure for section SECT. Create a new
346 structure if we haven't created one already. Return null if SECT
347 itself is null. */
349 static struct object_block *
350 get_block_for_section (section *sect)
352 struct object_block *block;
353 void **slot;
355 if (sect == NULL)
356 return NULL;
358 slot = htab_find_slot_with_hash (object_block_htab, sect,
359 hash_section (sect), INSERT);
360 block = (struct object_block *) *slot;
361 if (block == NULL)
363 block = ggc_cleared_alloc<object_block> ();
364 block->sect = sect;
365 *slot = block;
367 return block;
370 /* Create a symbol with label LABEL and place it at byte offset
371 OFFSET in BLOCK. OFFSET can be negative if the symbol's offset
372 is not yet known. LABEL must be a garbage-collected string. */
374 static rtx
375 create_block_symbol (const char *label, struct object_block *block,
376 HOST_WIDE_INT offset)
378 rtx symbol;
379 unsigned int size;
381 /* Create the extended SYMBOL_REF. */
382 size = RTX_HDR_SIZE + sizeof (struct block_symbol);
383 symbol = (rtx) ggc_internal_alloc (size);
385 /* Initialize the normal SYMBOL_REF fields. */
386 memset (symbol, 0, size);
387 PUT_CODE (symbol, SYMBOL_REF);
388 PUT_MODE (symbol, Pmode);
389 XSTR (symbol, 0) = label;
390 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_HAS_BLOCK_INFO;
392 /* Initialize the block_symbol stuff. */
393 SYMBOL_REF_BLOCK (symbol) = block;
394 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
396 return symbol;
399 /* Return a section with a particular name and with whatever SECTION_*
400 flags section_type_flags deems appropriate. The name of the section
401 is taken from NAME if nonnull, otherwise it is taken from DECL's
402 DECL_SECTION_NAME. DECL is the decl associated with the section
403 (see the section comment for details) and RELOC is as for
404 section_type_flags. */
406 section *
407 get_named_section (tree decl, const char *name, int reloc)
409 unsigned int flags;
411 if (name == NULL)
413 gcc_assert (decl && DECL_P (decl) && DECL_SECTION_NAME (decl));
414 name = DECL_SECTION_NAME (decl);
417 flags = targetm.section_type_flags (decl, name, reloc);
418 return get_section (name, flags, decl);
421 /* Worker for resolve_unique_section. */
423 static bool
424 set_implicit_section (struct symtab_node *n, void *data ATTRIBUTE_UNUSED)
426 n->implicit_section = true;
427 return false;
430 /* If required, set DECL_SECTION_NAME to a unique name. */
432 void
433 resolve_unique_section (tree decl, int reloc ATTRIBUTE_UNUSED,
434 int flag_function_or_data_sections)
436 if (DECL_SECTION_NAME (decl) == NULL
437 && targetm_common.have_named_sections
438 && (flag_function_or_data_sections
439 || DECL_COMDAT_GROUP (decl)))
441 targetm.asm_out.unique_section (decl, reloc);
442 if (DECL_SECTION_NAME (decl))
443 symtab_node::get (decl)->call_for_symbol_and_aliases
444 (set_implicit_section, NULL, true);
448 #ifdef BSS_SECTION_ASM_OP
450 #ifdef ASM_OUTPUT_ALIGNED_BSS
452 /* Utility function for targets to use in implementing
453 ASM_OUTPUT_ALIGNED_BSS.
454 ??? It is believed that this function will work in most cases so such
455 support is localized here. */
457 static void
458 asm_output_aligned_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
459 const char *name, unsigned HOST_WIDE_INT size,
460 int align)
462 switch_to_section (bss_section);
463 ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
464 #ifdef ASM_DECLARE_OBJECT_NAME
465 last_assemble_variable_decl = decl;
466 ASM_DECLARE_OBJECT_NAME (file, name, decl);
467 #else
468 /* Standard thing is just output label for the object. */
469 ASM_OUTPUT_LABEL (file, name);
470 #endif /* ASM_DECLARE_OBJECT_NAME */
471 ASM_OUTPUT_SKIP (file, size ? size : 1);
474 #endif
476 #endif /* BSS_SECTION_ASM_OP */
478 #ifndef USE_SELECT_SECTION_FOR_FUNCTIONS
479 /* Return the hot section for function DECL. Return text_section for
480 null DECLs. */
482 static section *
483 hot_function_section (tree decl)
485 if (decl != NULL_TREE
486 && DECL_SECTION_NAME (decl) != NULL
487 && targetm_common.have_named_sections)
488 return get_named_section (decl, NULL, 0);
489 else
490 return text_section;
492 #endif
494 /* Return section for TEXT_SECTION_NAME if DECL or DECL_SECTION_NAME (DECL)
495 is NULL.
497 When DECL_SECTION_NAME is non-NULL and it is implicit section and
498 NAMED_SECTION_SUFFIX is non-NULL, then produce section called
499 concatenate the name with NAMED_SECTION_SUFFIX.
500 Otherwise produce "TEXT_SECTION_NAME.IMPLICIT_NAME". */
502 section *
503 get_named_text_section (tree decl,
504 const char *text_section_name,
505 const char *named_section_suffix)
507 if (decl && DECL_SECTION_NAME (decl))
509 if (named_section_suffix)
511 const char *dsn = DECL_SECTION_NAME (decl);
512 const char *stripped_name;
513 char *name, *buffer;
515 name = (char *) alloca (strlen (dsn) + 1);
516 memcpy (name, dsn,
517 strlen (dsn) + 1);
519 stripped_name = targetm.strip_name_encoding (name);
521 buffer = ACONCAT ((stripped_name, named_section_suffix, NULL));
522 return get_named_section (decl, buffer, 0);
524 else if (symtab_node::get (decl)->implicit_section)
526 const char *name;
528 /* Do not try to split gnu_linkonce functions. This gets somewhat
529 slipperly. */
530 if (DECL_COMDAT_GROUP (decl) && !HAVE_COMDAT_GROUP)
531 return NULL;
532 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
533 name = targetm.strip_name_encoding (name);
534 return get_named_section (decl, ACONCAT ((text_section_name, ".",
535 name, NULL)), 0);
537 else
538 return NULL;
540 return get_named_section (decl, text_section_name, 0);
543 /* Choose named function section based on its frequency. */
545 section *
546 default_function_section (tree decl, enum node_frequency freq,
547 bool startup, bool exit)
549 #if defined HAVE_LD_EH_GC_SECTIONS && defined HAVE_LD_EH_GC_SECTIONS_BUG
550 /* Old GNU linkers have buggy --gc-section support, which sometimes
551 results in .gcc_except_table* sections being garbage collected. */
552 if (decl
553 && symtab_node::get (decl)->implicit_section)
554 return NULL;
555 #endif
557 if (!flag_reorder_functions
558 || !targetm_common.have_named_sections)
559 return NULL;
560 /* Startup code should go to startup subsection unless it is
561 unlikely executed (this happens especially with function splitting
562 where we can split away unnecessary parts of static constructors. */
563 if (startup && freq != NODE_FREQUENCY_UNLIKELY_EXECUTED)
565 /* If we do have a profile or(and) LTO phase is executed, we do not need
566 these ELF section. */
567 if (!in_lto_p || !flag_profile_values)
568 return get_named_text_section (decl, ".text.startup", NULL);
569 else
570 return NULL;
573 /* Similarly for exit. */
574 if (exit && freq != NODE_FREQUENCY_UNLIKELY_EXECUTED)
575 return get_named_text_section (decl, ".text.exit", NULL);
577 /* Group cold functions together, similarly for hot code. */
578 switch (freq)
580 case NODE_FREQUENCY_UNLIKELY_EXECUTED:
581 return get_named_text_section (decl, ".text.unlikely", NULL);
582 case NODE_FREQUENCY_HOT:
583 /* If we do have a profile or(and) LTO phase is executed, we do not need
584 these ELF section. */
585 if (!in_lto_p || !flag_profile_values)
586 return get_named_text_section (decl, ".text.hot", NULL);
587 default:
588 return NULL;
592 /* Return the section for function DECL.
594 If DECL is NULL_TREE, return the text section. We can be passed
595 NULL_TREE under some circumstances by dbxout.c at least.
597 If FORCE_COLD is true, return cold function section ignoring
598 the frequency info of cgraph_node. */
600 static section *
601 function_section_1 (tree decl, bool force_cold)
603 section *section = NULL;
604 enum node_frequency freq = NODE_FREQUENCY_NORMAL;
605 bool startup = false, exit = false;
607 if (decl)
609 struct cgraph_node *node = cgraph_node::get (decl);
611 if (node)
613 freq = node->frequency;
614 startup = node->only_called_at_startup;
615 exit = node->only_called_at_exit;
618 if (force_cold)
619 freq = NODE_FREQUENCY_UNLIKELY_EXECUTED;
621 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
622 if (decl != NULL_TREE
623 && DECL_SECTION_NAME (decl) != NULL)
625 if (targetm.asm_out.function_section)
626 section = targetm.asm_out.function_section (decl, freq,
627 startup, exit);
628 if (section)
629 return section;
630 return get_named_section (decl, NULL, 0);
632 else
633 return targetm.asm_out.select_section
634 (decl, freq == NODE_FREQUENCY_UNLIKELY_EXECUTED,
635 DECL_ALIGN (decl));
636 #else
637 if (targetm.asm_out.function_section)
638 section = targetm.asm_out.function_section (decl, freq, startup, exit);
639 if (section)
640 return section;
641 return hot_function_section (decl);
642 #endif
645 /* Return the section for function DECL.
647 If DECL is NULL_TREE, return the text section. We can be passed
648 NULL_TREE under some circumstances by dbxout.c at least. */
650 section *
651 function_section (tree decl)
653 /* Handle cases where function splitting code decides
654 to put function entry point into unlikely executed section
655 despite the fact that the function itself is not cold
656 (i.e. it is called rarely but contains a hot loop that is
657 better to live in hot subsection for the code locality). */
658 return function_section_1 (decl,
659 first_function_block_is_cold);
662 /* Return the section for the current function, take IN_COLD_SECTION_P
663 into account. */
665 section *
666 current_function_section (void)
668 return function_section_1 (current_function_decl, in_cold_section_p);
671 /* Tell assembler to switch to unlikely-to-be-executed text section. */
673 section *
674 unlikely_text_section (void)
676 return function_section_1 (current_function_decl, true);
679 /* When called within a function context, return true if the function
680 has been assigned a cold text section and if SECT is that section.
681 When called outside a function context, return true if SECT is the
682 default cold section. */
684 bool
685 unlikely_text_section_p (section *sect)
687 return sect == function_section_1 (current_function_decl, true);
690 /* Return the read-only data section associated with function DECL. */
692 section *
693 default_function_rodata_section (tree decl)
695 if (decl != NULL_TREE && DECL_SECTION_NAME (decl))
697 const char *name = DECL_SECTION_NAME (decl);
699 if (DECL_COMDAT_GROUP (decl) && HAVE_COMDAT_GROUP)
701 const char *dot;
702 size_t len;
703 char* rname;
705 dot = strchr (name + 1, '.');
706 if (!dot)
707 dot = name;
708 len = strlen (dot) + 8;
709 rname = (char *) alloca (len);
711 strcpy (rname, ".rodata");
712 strcat (rname, dot);
713 return get_section (rname, SECTION_LINKONCE, decl);
715 /* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo. */
716 else if (DECL_COMDAT_GROUP (decl)
717 && strncmp (name, ".gnu.linkonce.t.", 16) == 0)
719 size_t len = strlen (name) + 1;
720 char *rname = (char *) alloca (len);
722 memcpy (rname, name, len);
723 rname[14] = 'r';
724 return get_section (rname, SECTION_LINKONCE, decl);
726 /* For .text.foo we want to use .rodata.foo. */
727 else if (flag_function_sections && flag_data_sections
728 && strncmp (name, ".text.", 6) == 0)
730 size_t len = strlen (name) + 1;
731 char *rname = (char *) alloca (len + 2);
733 memcpy (rname, ".rodata", 7);
734 memcpy (rname + 7, name + 5, len - 5);
735 return get_section (rname, 0, decl);
739 return readonly_data_section;
742 /* Return the read-only data section associated with function DECL
743 for targets where that section should be always the single
744 readonly data section. */
746 section *
747 default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED)
749 return readonly_data_section;
752 /* Return the section to use for string merging. */
754 static section *
755 mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
756 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
757 unsigned int flags ATTRIBUTE_UNUSED)
759 HOST_WIDE_INT len;
761 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
762 && TREE_CODE (decl) == STRING_CST
763 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
764 && align <= 256
765 && (len = int_size_in_bytes (TREE_TYPE (decl))) > 0
766 && TREE_STRING_LENGTH (decl) >= len)
768 enum machine_mode mode;
769 unsigned int modesize;
770 const char *str;
771 HOST_WIDE_INT i;
772 int j, unit;
773 const char *prefix = targetm.asm_out.mergeable_rodata_prefix;
774 char *name = (char *) alloca (strlen (prefix) + 30);
776 mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl)));
777 modesize = GET_MODE_BITSIZE (mode);
778 if (modesize >= 8 && modesize <= 256
779 && (modesize & (modesize - 1)) == 0)
781 if (align < modesize)
782 align = modesize;
784 str = TREE_STRING_POINTER (decl);
785 unit = GET_MODE_SIZE (mode);
787 /* Check for embedded NUL characters. */
788 for (i = 0; i < len; i += unit)
790 for (j = 0; j < unit; j++)
791 if (str[i + j] != '\0')
792 break;
793 if (j == unit)
794 break;
796 if (i == len - unit)
798 sprintf (name, "%s.str%d.%d", prefix,
799 modesize / 8, (int) (align / 8));
800 flags |= (modesize / 8) | SECTION_MERGE | SECTION_STRINGS;
801 return get_section (name, flags, NULL);
806 return readonly_data_section;
809 /* Return the section to use for constant merging. */
811 section *
812 mergeable_constant_section (enum machine_mode mode ATTRIBUTE_UNUSED,
813 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
814 unsigned int flags ATTRIBUTE_UNUSED)
816 unsigned int modesize = GET_MODE_BITSIZE (mode);
818 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
819 && mode != VOIDmode
820 && mode != BLKmode
821 && modesize <= align
822 && align >= 8
823 && align <= 256
824 && (align & (align - 1)) == 0)
826 const char *prefix = targetm.asm_out.mergeable_rodata_prefix;
827 char *name = (char *) alloca (strlen (prefix) + 30);
829 sprintf (name, "%s.cst%d", prefix, (int) (align / 8));
830 flags |= (align / 8) | SECTION_MERGE;
831 return get_section (name, flags, NULL);
833 return readonly_data_section;
836 /* Given NAME, a putative register name, discard any customary prefixes. */
838 static const char *
839 strip_reg_name (const char *name)
841 #ifdef REGISTER_PREFIX
842 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
843 name += strlen (REGISTER_PREFIX);
844 #endif
845 if (name[0] == '%' || name[0] == '#')
846 name++;
847 return name;
850 /* The user has asked for a DECL to have a particular name. Set (or
851 change) it in such a way that we don't prefix an underscore to
852 it. */
853 void
854 set_user_assembler_name (tree decl, const char *name)
856 char *starred = (char *) alloca (strlen (name) + 2);
857 starred[0] = '*';
858 strcpy (starred + 1, name);
859 change_decl_assembler_name (decl, get_identifier (starred));
860 SET_DECL_RTL (decl, NULL_RTX);
863 /* Decode an `asm' spec for a declaration as a register name.
864 Return the register number, or -1 if nothing specified,
865 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
866 or -3 if ASMSPEC is `cc' and is not recognized,
867 or -4 if ASMSPEC is `memory' and is not recognized.
868 Accept an exact spelling or a decimal number.
869 Prefixes such as % are optional. */
872 decode_reg_name_and_count (const char *asmspec, int *pnregs)
874 /* Presume just one register is clobbered. */
875 *pnregs = 1;
877 if (asmspec != 0)
879 int i;
881 /* Get rid of confusing prefixes. */
882 asmspec = strip_reg_name (asmspec);
884 /* Allow a decimal number as a "register name". */
885 for (i = strlen (asmspec) - 1; i >= 0; i--)
886 if (! ISDIGIT (asmspec[i]))
887 break;
888 if (asmspec[0] != 0 && i < 0)
890 i = atoi (asmspec);
891 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
892 return i;
893 else
894 return -2;
897 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
898 if (reg_names[i][0]
899 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
900 return i;
902 #ifdef OVERLAPPING_REGISTER_NAMES
904 static const struct
906 const char *const name;
907 const int number;
908 const int nregs;
909 } table[] = OVERLAPPING_REGISTER_NAMES;
911 for (i = 0; i < (int) ARRAY_SIZE (table); i++)
912 if (table[i].name[0]
913 && ! strcmp (asmspec, table[i].name))
915 *pnregs = table[i].nregs;
916 return table[i].number;
919 #endif /* OVERLAPPING_REGISTER_NAMES */
921 #ifdef ADDITIONAL_REGISTER_NAMES
923 static const struct { const char *const name; const int number; } table[]
924 = ADDITIONAL_REGISTER_NAMES;
926 for (i = 0; i < (int) ARRAY_SIZE (table); i++)
927 if (table[i].name[0]
928 && ! strcmp (asmspec, table[i].name))
929 return table[i].number;
931 #endif /* ADDITIONAL_REGISTER_NAMES */
933 if (!strcmp (asmspec, "memory"))
934 return -4;
936 if (!strcmp (asmspec, "cc"))
937 return -3;
939 return -2;
942 return -1;
946 decode_reg_name (const char *name)
948 int count;
949 return decode_reg_name_and_count (name, &count);
953 /* Return true if DECL's initializer is suitable for a BSS section. */
955 bool
956 bss_initializer_p (const_tree decl)
958 return (DECL_INITIAL (decl) == NULL
959 /* In LTO we have no errors in program; error_mark_node is used
960 to mark offlined constructors. */
961 || (DECL_INITIAL (decl) == error_mark_node
962 && !in_lto_p)
963 || (flag_zero_initialized_in_bss
964 /* Leave constant zeroes in .rodata so they
965 can be shared. */
966 && !TREE_READONLY (decl)
967 && initializer_zerop (DECL_INITIAL (decl))));
970 /* Compute the alignment of variable specified by DECL.
971 DONT_OUTPUT_DATA is from assemble_variable. */
973 void
974 align_variable (tree decl, bool dont_output_data)
976 unsigned int align = DECL_ALIGN (decl);
978 /* In the case for initialing an array whose length isn't specified,
979 where we have not yet been able to do the layout,
980 figure out the proper alignment now. */
981 if (dont_output_data && DECL_SIZE (decl) == 0
982 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
983 align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
985 /* Some object file formats have a maximum alignment which they support.
986 In particular, a.out format supports a maximum alignment of 4. */
987 if (align > MAX_OFILE_ALIGNMENT)
989 error ("alignment of %q+D is greater than maximum object "
990 "file alignment %d", decl,
991 MAX_OFILE_ALIGNMENT/BITS_PER_UNIT);
992 align = MAX_OFILE_ALIGNMENT;
995 if (! DECL_USER_ALIGN (decl))
997 #ifdef DATA_ABI_ALIGNMENT
998 unsigned int data_abi_align
999 = DATA_ABI_ALIGNMENT (TREE_TYPE (decl), align);
1000 /* For backwards compatibility, don't assume the ABI alignment for
1001 TLS variables. */
1002 if (! DECL_THREAD_LOCAL_P (decl) || data_abi_align <= BITS_PER_WORD)
1003 align = data_abi_align;
1004 #endif
1006 /* On some machines, it is good to increase alignment sometimes.
1007 But as DECL_ALIGN is used both for actually emitting the variable
1008 and for code accessing the variable as guaranteed alignment, we
1009 can only increase the alignment if it is a performance optimization
1010 if the references to it must bind to the current definition. */
1011 if (decl_binds_to_current_def_p (decl)
1012 && !DECL_VIRTUAL_P (decl))
1014 #ifdef DATA_ALIGNMENT
1015 unsigned int data_align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
1016 /* Don't increase alignment too much for TLS variables - TLS space
1017 is too precious. */
1018 if (! DECL_THREAD_LOCAL_P (decl) || data_align <= BITS_PER_WORD)
1019 align = data_align;
1020 #endif
1021 #ifdef CONSTANT_ALIGNMENT
1022 if (DECL_INITIAL (decl) != 0
1023 /* In LTO we have no errors in program; error_mark_node is used
1024 to mark offlined constructors. */
1025 && (in_lto_p || DECL_INITIAL (decl) != error_mark_node))
1027 unsigned int const_align
1028 = CONSTANT_ALIGNMENT (DECL_INITIAL (decl), align);
1029 /* Don't increase alignment too much for TLS variables - TLS
1030 space is too precious. */
1031 if (! DECL_THREAD_LOCAL_P (decl) || const_align <= BITS_PER_WORD)
1032 align = const_align;
1034 #endif
1038 /* Reset the alignment in case we have made it tighter, so we can benefit
1039 from it in get_pointer_alignment. */
1040 DECL_ALIGN (decl) = align;
1043 /* Return DECL_ALIGN (decl), possibly increased for optimization purposes
1044 beyond what align_variable returned. */
1046 static unsigned int
1047 get_variable_align (tree decl)
1049 unsigned int align = DECL_ALIGN (decl);
1051 /* For user aligned vars or static vars align_variable already did
1052 everything. */
1053 if (DECL_USER_ALIGN (decl) || !TREE_PUBLIC (decl))
1054 return align;
1056 #ifdef DATA_ABI_ALIGNMENT
1057 if (DECL_THREAD_LOCAL_P (decl))
1058 align = DATA_ABI_ALIGNMENT (TREE_TYPE (decl), align);
1059 #endif
1061 /* For decls that bind to the current definition, align_variable
1062 did also everything, except for not assuming ABI required alignment
1063 of TLS variables. For other vars, increase the alignment here
1064 as an optimization. */
1065 if (!decl_binds_to_current_def_p (decl))
1067 /* On some machines, it is good to increase alignment sometimes. */
1068 #ifdef DATA_ALIGNMENT
1069 unsigned int data_align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
1070 /* Don't increase alignment too much for TLS variables - TLS space
1071 is too precious. */
1072 if (! DECL_THREAD_LOCAL_P (decl) || data_align <= BITS_PER_WORD)
1073 align = data_align;
1074 #endif
1075 #ifdef CONSTANT_ALIGNMENT
1076 if (DECL_INITIAL (decl) != 0
1077 /* In LTO we have no errors in program; error_mark_node is used
1078 to mark offlined constructors. */
1079 && (in_lto_p || DECL_INITIAL (decl) != error_mark_node))
1081 unsigned int const_align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl),
1082 align);
1083 /* Don't increase alignment too much for TLS variables - TLS space
1084 is too precious. */
1085 if (! DECL_THREAD_LOCAL_P (decl) || const_align <= BITS_PER_WORD)
1086 align = const_align;
1088 #endif
1091 return align;
1094 /* Return the section into which the given VAR_DECL or CONST_DECL
1095 should be placed. PREFER_NOSWITCH_P is true if a noswitch
1096 section should be used wherever possible. */
1098 section *
1099 get_variable_section (tree decl, bool prefer_noswitch_p)
1101 addr_space_t as = ADDR_SPACE_GENERIC;
1102 int reloc;
1103 varpool_node *vnode = varpool_node::get (decl);
1104 if (vnode)
1106 vnode = vnode->ultimate_alias_target ();
1107 decl = vnode->decl;
1110 if (TREE_TYPE (decl) != error_mark_node)
1111 as = TYPE_ADDR_SPACE (TREE_TYPE (decl));
1113 /* We need the constructor to figure out reloc flag. */
1114 if (vnode)
1115 vnode->get_constructor ();
1117 if (DECL_COMMON (decl))
1119 /* If the decl has been given an explicit section name, or it resides
1120 in a non-generic address space, then it isn't common, and shouldn't
1121 be handled as such. */
1122 gcc_assert (DECL_SECTION_NAME (decl) == NULL
1123 && ADDR_SPACE_GENERIC_P (as));
1124 if (DECL_THREAD_LOCAL_P (decl))
1125 return tls_comm_section;
1126 else if (TREE_PUBLIC (decl) && bss_initializer_p (decl))
1127 return comm_section;
1130 if (DECL_INITIAL (decl) == error_mark_node)
1131 reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;
1132 else if (DECL_INITIAL (decl))
1133 reloc = compute_reloc_for_constant (DECL_INITIAL (decl));
1134 else
1135 reloc = 0;
1137 resolve_unique_section (decl, reloc, flag_data_sections);
1138 if (IN_NAMED_SECTION (decl))
1139 return get_named_section (decl, NULL, reloc);
1141 if (ADDR_SPACE_GENERIC_P (as)
1142 && !DECL_THREAD_LOCAL_P (decl)
1143 && !(prefer_noswitch_p && targetm.have_switchable_bss_sections)
1144 && bss_initializer_p (decl))
1146 if (!TREE_PUBLIC (decl)
1147 && !((flag_sanitize & SANITIZE_ADDRESS)
1148 && asan_protect_global (decl)))
1149 return lcomm_section;
1150 if (bss_noswitch_section)
1151 return bss_noswitch_section;
1154 return targetm.asm_out.select_section (decl, reloc,
1155 get_variable_align (decl));
1158 /* Return the block into which object_block DECL should be placed. */
1160 static struct object_block *
1161 get_block_for_decl (tree decl)
1163 section *sect;
1165 if (TREE_CODE (decl) == VAR_DECL)
1167 /* The object must be defined in this translation unit. */
1168 if (DECL_EXTERNAL (decl))
1169 return NULL;
1171 /* There's no point using object blocks for something that is
1172 isolated by definition. */
1173 if (DECL_COMDAT_GROUP (decl))
1174 return NULL;
1177 /* We can only calculate block offsets if the decl has a known
1178 constant size. */
1179 if (DECL_SIZE_UNIT (decl) == NULL)
1180 return NULL;
1181 if (!tree_fits_uhwi_p (DECL_SIZE_UNIT (decl)))
1182 return NULL;
1184 /* Find out which section should contain DECL. We cannot put it into
1185 an object block if it requires a standalone definition. */
1186 if (TREE_CODE (decl) == VAR_DECL)
1187 align_variable (decl, 0);
1188 sect = get_variable_section (decl, true);
1189 if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
1190 return NULL;
1192 return get_block_for_section (sect);
1195 /* Make sure block symbol SYMBOL is in block BLOCK. */
1197 static void
1198 change_symbol_block (rtx symbol, struct object_block *block)
1200 if (block != SYMBOL_REF_BLOCK (symbol))
1202 gcc_assert (SYMBOL_REF_BLOCK_OFFSET (symbol) < 0);
1203 SYMBOL_REF_BLOCK (symbol) = block;
1207 /* Return true if it is possible to put DECL in an object_block. */
1209 static bool
1210 use_blocks_for_decl_p (tree decl)
1212 struct symtab_node *snode;
1214 /* Only data DECLs can be placed into object blocks. */
1215 if (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != CONST_DECL)
1216 return false;
1218 /* Detect decls created by dw2_force_const_mem. Such decls are
1219 special because DECL_INITIAL doesn't specify the decl's true value.
1220 dw2_output_indirect_constants will instead call assemble_variable
1221 with dont_output_data set to 1 and then print the contents itself. */
1222 if (DECL_INITIAL (decl) == decl)
1223 return false;
1225 /* If this decl is an alias, then we don't want to emit a
1226 definition. */
1227 if (TREE_CODE (decl) == VAR_DECL
1228 && (snode = symtab_node::get (decl)) != NULL
1229 && snode->alias)
1230 return false;
1232 return targetm.use_blocks_for_decl_p (decl);
1235 /* Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL should
1236 have static storage duration. In other words, it should not be an
1237 automatic variable, including PARM_DECLs.
1239 There is, however, one exception: this function handles variables
1240 explicitly placed in a particular register by the user.
1242 This is never called for PARM_DECL nodes. */
1244 void
1245 make_decl_rtl (tree decl)
1247 const char *name = 0;
1248 int reg_number;
1249 rtx x;
1251 /* Check that we are not being given an automatic variable. */
1252 gcc_assert (TREE_CODE (decl) != PARM_DECL
1253 && TREE_CODE (decl) != RESULT_DECL);
1255 /* A weak alias has TREE_PUBLIC set but not the other bits. */
1256 gcc_assert (TREE_CODE (decl) != VAR_DECL
1257 || TREE_STATIC (decl)
1258 || TREE_PUBLIC (decl)
1259 || DECL_EXTERNAL (decl)
1260 || DECL_REGISTER (decl));
1262 /* And that we were not given a type or a label. */
1263 gcc_assert (TREE_CODE (decl) != TYPE_DECL
1264 && TREE_CODE (decl) != LABEL_DECL);
1266 /* For a duplicate declaration, we can be called twice on the
1267 same DECL node. Don't discard the RTL already made. */
1268 if (DECL_RTL_SET_P (decl))
1270 /* If the old RTL had the wrong mode, fix the mode. */
1271 x = DECL_RTL (decl);
1272 if (GET_MODE (x) != DECL_MODE (decl))
1273 SET_DECL_RTL (decl, adjust_address_nv (x, DECL_MODE (decl), 0));
1275 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1276 return;
1278 /* ??? Another way to do this would be to maintain a hashed
1279 table of such critters. Instead of adding stuff to a DECL
1280 to give certain attributes to it, we could use an external
1281 hash map from DECL to set of attributes. */
1283 /* Let the target reassign the RTL if it wants.
1284 This is necessary, for example, when one machine specific
1285 decl attribute overrides another. */
1286 targetm.encode_section_info (decl, DECL_RTL (decl), false);
1288 /* If the symbol has a SYMBOL_REF_BLOCK field, update it based
1289 on the new decl information. */
1290 if (MEM_P (x)
1291 && GET_CODE (XEXP (x, 0)) == SYMBOL_REF
1292 && SYMBOL_REF_HAS_BLOCK_INFO_P (XEXP (x, 0)))
1293 change_symbol_block (XEXP (x, 0), get_block_for_decl (decl));
1295 return;
1298 /* If this variable belongs to the global constant pool, retrieve the
1299 pre-computed RTL or recompute it in LTO mode. */
1300 if (TREE_CODE (decl) == VAR_DECL && DECL_IN_CONSTANT_POOL (decl))
1302 SET_DECL_RTL (decl, output_constant_def (DECL_INITIAL (decl), 1));
1303 return;
1306 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
1308 if (name[0] != '*' && TREE_CODE (decl) != FUNCTION_DECL
1309 && DECL_REGISTER (decl))
1311 error ("register name not specified for %q+D", decl);
1313 else if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1315 const char *asmspec = name+1;
1316 enum machine_mode mode = DECL_MODE (decl);
1317 reg_number = decode_reg_name (asmspec);
1318 /* First detect errors in declaring global registers. */
1319 if (reg_number == -1)
1320 error ("register name not specified for %q+D", decl);
1321 else if (reg_number < 0)
1322 error ("invalid register name for %q+D", decl);
1323 else if (mode == BLKmode)
1324 error ("data type of %q+D isn%'t suitable for a register",
1325 decl);
1326 else if (!in_hard_reg_set_p (accessible_reg_set, mode, reg_number))
1327 error ("the register specified for %q+D cannot be accessed"
1328 " by the current target", decl);
1329 else if (!in_hard_reg_set_p (operand_reg_set, mode, reg_number))
1330 error ("the register specified for %q+D is not general enough"
1331 " to be used as a register variable", decl);
1332 else if (!HARD_REGNO_MODE_OK (reg_number, mode))
1333 error ("register specified for %q+D isn%'t suitable for data type",
1334 decl);
1335 /* Now handle properly declared static register variables. */
1336 else
1338 int nregs;
1340 if (DECL_INITIAL (decl) != 0 && TREE_STATIC (decl))
1342 DECL_INITIAL (decl) = 0;
1343 error ("global register variable has initial value");
1345 if (TREE_THIS_VOLATILE (decl))
1346 warning (OPT_Wvolatile_register_var,
1347 "optimization may eliminate reads and/or "
1348 "writes to register variables");
1350 /* If the user specified one of the eliminables registers here,
1351 e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
1352 confused with that register and be eliminated. This usage is
1353 somewhat suspect... */
1355 SET_DECL_RTL (decl, gen_rtx_raw_REG (mode, reg_number));
1356 ORIGINAL_REGNO (DECL_RTL (decl)) = reg_number;
1357 REG_USERVAR_P (DECL_RTL (decl)) = 1;
1359 if (TREE_STATIC (decl))
1361 /* Make this register global, so not usable for anything
1362 else. */
1363 #ifdef ASM_DECLARE_REGISTER_GLOBAL
1364 name = IDENTIFIER_POINTER (DECL_NAME (decl));
1365 ASM_DECLARE_REGISTER_GLOBAL (asm_out_file, decl, reg_number, name);
1366 #endif
1367 nregs = hard_regno_nregs[reg_number][mode];
1368 while (nregs > 0)
1369 globalize_reg (decl, reg_number + --nregs);
1372 /* As a register variable, it has no section. */
1373 return;
1376 /* Now handle ordinary static variables and functions (in memory).
1377 Also handle vars declared register invalidly. */
1378 else if (name[0] == '*')
1380 #ifdef REGISTER_PREFIX
1381 if (strlen (REGISTER_PREFIX) != 0)
1383 reg_number = decode_reg_name (name);
1384 if (reg_number >= 0 || reg_number == -3)
1385 error ("register name given for non-register variable %q+D", decl);
1387 #endif
1390 /* Specifying a section attribute on a variable forces it into a
1391 non-.bss section, and thus it cannot be common. */
1392 /* FIXME: In general this code should not be necessary because
1393 visibility pass is doing the same work. But notice_global_symbol
1394 is called early and it needs to make DECL_RTL to get the name.
1395 we take care of recomputing the DECL_RTL after visibility is changed. */
1396 if (TREE_CODE (decl) == VAR_DECL
1397 && (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
1398 && DECL_SECTION_NAME (decl) != NULL
1399 && DECL_INITIAL (decl) == NULL_TREE
1400 && DECL_COMMON (decl))
1401 DECL_COMMON (decl) = 0;
1403 /* Variables can't be both common and weak. */
1404 if (TREE_CODE (decl) == VAR_DECL && DECL_WEAK (decl))
1405 DECL_COMMON (decl) = 0;
1407 if (use_object_blocks_p () && use_blocks_for_decl_p (decl))
1408 x = create_block_symbol (name, get_block_for_decl (decl), -1);
1409 else
1411 enum machine_mode address_mode = Pmode;
1412 if (TREE_TYPE (decl) != error_mark_node)
1414 addr_space_t as = TYPE_ADDR_SPACE (TREE_TYPE (decl));
1415 address_mode = targetm.addr_space.address_mode (as);
1417 x = gen_rtx_SYMBOL_REF (address_mode, name);
1419 SYMBOL_REF_WEAK (x) = DECL_WEAK (decl);
1420 SET_SYMBOL_REF_DECL (x, decl);
1422 x = gen_rtx_MEM (DECL_MODE (decl), x);
1423 if (TREE_CODE (decl) != FUNCTION_DECL)
1424 set_mem_attributes (x, decl, 1);
1425 SET_DECL_RTL (decl, x);
1427 /* Optionally set flags or add text to the name to record information
1428 such as that it is a function name.
1429 If the name is changed, the macro ASM_OUTPUT_LABELREF
1430 will have to know how to strip this information. */
1431 targetm.encode_section_info (decl, DECL_RTL (decl), true);
1434 /* Like make_decl_rtl, but inhibit creation of new alias sets when
1435 calling make_decl_rtl. Also, reset DECL_RTL before returning the
1436 rtl. */
1439 make_decl_rtl_for_debug (tree decl)
1441 unsigned int save_aliasing_flag;
1442 rtx rtl;
1444 if (DECL_RTL_SET_P (decl))
1445 return DECL_RTL (decl);
1447 /* Kludge alert! Somewhere down the call chain, make_decl_rtl will
1448 call new_alias_set. If running with -fcompare-debug, sometimes
1449 we do not want to create alias sets that will throw the alias
1450 numbers off in the comparison dumps. So... clearing
1451 flag_strict_aliasing will keep new_alias_set() from creating a
1452 new set. */
1453 save_aliasing_flag = flag_strict_aliasing;
1454 flag_strict_aliasing = 0;
1456 rtl = DECL_RTL (decl);
1457 /* Reset DECL_RTL back, as various parts of the compiler expects
1458 DECL_RTL set meaning it is actually going to be output. */
1459 SET_DECL_RTL (decl, NULL);
1461 flag_strict_aliasing = save_aliasing_flag;
1462 return rtl;
1465 /* Output a string of literal assembler code
1466 for an `asm' keyword used between functions. */
1468 void
1469 assemble_asm (tree string)
1471 const char *p;
1472 app_enable ();
1474 if (TREE_CODE (string) == ADDR_EXPR)
1475 string = TREE_OPERAND (string, 0);
1477 p = TREE_STRING_POINTER (string);
1478 fprintf (asm_out_file, "%s%s\n", p[0] == '\t' ? "" : "\t", p);
1481 /* Write the address of the entity given by SYMBOL to SEC. */
1482 void
1483 assemble_addr_to_section (rtx symbol, section *sec)
1485 switch_to_section (sec);
1486 assemble_align (POINTER_SIZE);
1487 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1490 /* Return the numbered .ctors.N (if CONSTRUCTOR_P) or .dtors.N (if
1491 not) section for PRIORITY. */
1492 section *
1493 get_cdtor_priority_section (int priority, bool constructor_p)
1495 char buf[16];
1497 /* ??? This only works reliably with the GNU linker. */
1498 sprintf (buf, "%s.%.5u",
1499 constructor_p ? ".ctors" : ".dtors",
1500 /* Invert the numbering so the linker puts us in the proper
1501 order; constructors are run from right to left, and the
1502 linker sorts in increasing order. */
1503 MAX_INIT_PRIORITY - priority);
1504 return get_section (buf, SECTION_WRITE, NULL);
1507 void
1508 default_named_section_asm_out_destructor (rtx symbol, int priority)
1510 section *sec;
1512 if (priority != DEFAULT_INIT_PRIORITY)
1513 sec = get_cdtor_priority_section (priority,
1514 /*constructor_p=*/false);
1515 else
1516 sec = get_section (".dtors", SECTION_WRITE, NULL);
1518 assemble_addr_to_section (symbol, sec);
1521 #ifdef DTORS_SECTION_ASM_OP
1522 void
1523 default_dtor_section_asm_out_destructor (rtx symbol,
1524 int priority ATTRIBUTE_UNUSED)
1526 assemble_addr_to_section (symbol, dtors_section);
1528 #endif
1530 void
1531 default_named_section_asm_out_constructor (rtx symbol, int priority)
1533 section *sec;
1535 if (priority != DEFAULT_INIT_PRIORITY)
1536 sec = get_cdtor_priority_section (priority,
1537 /*constructor_p=*/true);
1538 else
1539 sec = get_section (".ctors", SECTION_WRITE, NULL);
1541 assemble_addr_to_section (symbol, sec);
1544 #ifdef CTORS_SECTION_ASM_OP
1545 void
1546 default_ctor_section_asm_out_constructor (rtx symbol,
1547 int priority ATTRIBUTE_UNUSED)
1549 assemble_addr_to_section (symbol, ctors_section);
1551 #endif
1553 /* CONSTANT_POOL_BEFORE_FUNCTION may be defined as an expression with
1554 a nonzero value if the constant pool should be output before the
1555 start of the function, or a zero value if the pool should output
1556 after the end of the function. The default is to put it before the
1557 start. */
1559 #ifndef CONSTANT_POOL_BEFORE_FUNCTION
1560 #define CONSTANT_POOL_BEFORE_FUNCTION 1
1561 #endif
1563 /* DECL is an object (either VAR_DECL or FUNCTION_DECL) which is going
1564 to be output to assembler.
1565 Set first_global_object_name and weak_global_object_name as appropriate. */
1567 void
1568 notice_global_symbol (tree decl)
1570 const char **type = &first_global_object_name;
1572 if (first_global_object_name
1573 || !TREE_PUBLIC (decl)
1574 || DECL_EXTERNAL (decl)
1575 || !DECL_NAME (decl)
1576 || (TREE_CODE (decl) != FUNCTION_DECL
1577 && (TREE_CODE (decl) != VAR_DECL
1578 || (DECL_COMMON (decl)
1579 && (DECL_INITIAL (decl) == 0
1580 || DECL_INITIAL (decl) == error_mark_node))))
1581 || !MEM_P (DECL_RTL (decl)))
1582 return;
1584 /* We win when global object is found, but it is useful to know about weak
1585 symbol as well so we can produce nicer unique names. */
1586 if (DECL_WEAK (decl) || DECL_ONE_ONLY (decl) || flag_shlib)
1587 type = &weak_global_object_name;
1589 if (!*type)
1591 const char *p;
1592 const char *name;
1593 rtx decl_rtl = DECL_RTL (decl);
1595 p = targetm.strip_name_encoding (XSTR (XEXP (decl_rtl, 0), 0));
1596 name = ggc_strdup (p);
1598 *type = name;
1602 /* If not using flag_reorder_blocks_and_partition, decide early whether the
1603 current function goes into the cold section, so that targets can use
1604 current_function_section during RTL expansion. DECL describes the
1605 function. */
1607 void
1608 decide_function_section (tree decl)
1610 first_function_block_is_cold = false;
1612 if (flag_reorder_blocks_and_partition)
1613 /* We will decide in assemble_start_function. */
1614 return;
1616 if (DECL_SECTION_NAME (decl))
1618 struct cgraph_node *node = cgraph_node::get (current_function_decl);
1619 /* Calls to function_section rely on first_function_block_is_cold
1620 being accurate. */
1621 first_function_block_is_cold = (node
1622 && node->frequency
1623 == NODE_FREQUENCY_UNLIKELY_EXECUTED);
1626 in_cold_section_p = first_function_block_is_cold;
1629 /* Output assembler code for the constant pool of a function and associated
1630 with defining the name of the function. DECL describes the function.
1631 NAME is the function's name. For the constant pool, we use the current
1632 constant pool data. */
1634 void
1635 assemble_start_function (tree decl, const char *fnname)
1637 int align;
1638 char tmp_label[100];
1639 bool hot_label_written = false;
1641 if (flag_reorder_blocks_and_partition)
1643 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTB", const_labelno);
1644 crtl->subsections.hot_section_label = ggc_strdup (tmp_label);
1645 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDB", const_labelno);
1646 crtl->subsections.cold_section_label = ggc_strdup (tmp_label);
1647 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTE", const_labelno);
1648 crtl->subsections.hot_section_end_label = ggc_strdup (tmp_label);
1649 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDE", const_labelno);
1650 crtl->subsections.cold_section_end_label = ggc_strdup (tmp_label);
1651 const_labelno++;
1653 else
1655 crtl->subsections.hot_section_label = NULL;
1656 crtl->subsections.cold_section_label = NULL;
1657 crtl->subsections.hot_section_end_label = NULL;
1658 crtl->subsections.cold_section_end_label = NULL;
1661 /* The following code does not need preprocessing in the assembler. */
1663 app_disable ();
1665 if (CONSTANT_POOL_BEFORE_FUNCTION)
1666 output_constant_pool (fnname, decl);
1668 /* Make sure the not and cold text (code) sections are properly
1669 aligned. This is necessary here in the case where the function
1670 has both hot and cold sections, because we don't want to re-set
1671 the alignment when the section switch happens mid-function. */
1673 if (flag_reorder_blocks_and_partition)
1675 first_function_block_is_cold = false;
1677 switch_to_section (unlikely_text_section ());
1678 assemble_align (DECL_ALIGN (decl));
1679 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.cold_section_label);
1681 /* When the function starts with a cold section, we need to explicitly
1682 align the hot section and write out the hot section label.
1683 But if the current function is a thunk, we do not have a CFG. */
1684 if (!cfun->is_thunk
1685 && BB_PARTITION (ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb) == BB_COLD_PARTITION)
1687 switch_to_section (text_section);
1688 assemble_align (DECL_ALIGN (decl));
1689 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_label);
1690 hot_label_written = true;
1691 first_function_block_is_cold = true;
1693 in_cold_section_p = first_function_block_is_cold;
1697 /* Switch to the correct text section for the start of the function. */
1699 switch_to_section (function_section (decl));
1700 if (flag_reorder_blocks_and_partition
1701 && !hot_label_written)
1702 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_label);
1704 /* Tell assembler to move to target machine's alignment for functions. */
1705 align = floor_log2 (DECL_ALIGN (decl) / BITS_PER_UNIT);
1706 if (align > 0)
1708 ASM_OUTPUT_ALIGN (asm_out_file, align);
1711 /* Handle a user-specified function alignment.
1712 Note that we still need to align to DECL_ALIGN, as above,
1713 because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */
1714 if (! DECL_USER_ALIGN (decl)
1715 && align_functions_log > align
1716 && optimize_function_for_speed_p (cfun))
1718 #ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
1719 ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file,
1720 align_functions_log, align_functions - 1);
1721 #else
1722 ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log);
1723 #endif
1726 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
1727 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
1728 #endif
1730 if (!DECL_IGNORED_P (decl))
1731 (*debug_hooks->begin_function) (decl);
1733 /* Make function name accessible from other files, if appropriate. */
1735 if (TREE_PUBLIC (decl))
1737 notice_global_symbol (decl);
1739 globalize_decl (decl);
1741 maybe_assemble_visibility (decl);
1744 if (DECL_PRESERVE_P (decl))
1745 targetm.asm_out.mark_decl_preserved (fnname);
1747 /* Do any machine/system dependent processing of the function name. */
1748 #ifdef ASM_DECLARE_FUNCTION_NAME
1749 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
1750 #else
1751 /* Standard thing is just output label for the function. */
1752 ASM_OUTPUT_FUNCTION_LABEL (asm_out_file, fnname, current_function_decl);
1753 #endif /* ASM_DECLARE_FUNCTION_NAME */
1755 if (lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (decl)))
1756 saw_no_split_stack = true;
1759 /* Output assembler code associated with defining the size of the
1760 function. DECL describes the function. NAME is the function's name. */
1762 void
1763 assemble_end_function (tree decl, const char *fnname ATTRIBUTE_UNUSED)
1765 #ifdef ASM_DECLARE_FUNCTION_SIZE
1766 /* We could have switched section in the middle of the function. */
1767 if (flag_reorder_blocks_and_partition)
1768 switch_to_section (function_section (decl));
1769 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
1770 #endif
1771 if (! CONSTANT_POOL_BEFORE_FUNCTION)
1773 output_constant_pool (fnname, decl);
1774 switch_to_section (function_section (decl)); /* need to switch back */
1776 /* Output labels for end of hot/cold text sections (to be used by
1777 debug info.) */
1778 if (flag_reorder_blocks_and_partition)
1780 section *save_text_section;
1782 save_text_section = in_section;
1783 switch_to_section (unlikely_text_section ());
1784 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.cold_section_end_label);
1785 if (first_function_block_is_cold)
1786 switch_to_section (text_section);
1787 else
1788 switch_to_section (function_section (decl));
1789 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_end_label);
1790 switch_to_section (save_text_section);
1794 /* Assemble code to leave SIZE bytes of zeros. */
1796 void
1797 assemble_zeros (unsigned HOST_WIDE_INT size)
1799 /* Do no output if -fsyntax-only. */
1800 if (flag_syntax_only)
1801 return;
1803 #ifdef ASM_NO_SKIP_IN_TEXT
1804 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
1805 so we must output 0s explicitly in the text section. */
1806 if (ASM_NO_SKIP_IN_TEXT && (in_section->common.flags & SECTION_CODE) != 0)
1808 unsigned HOST_WIDE_INT i;
1809 for (i = 0; i < size; i++)
1810 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1);
1812 else
1813 #endif
1814 if (size > 0)
1815 ASM_OUTPUT_SKIP (asm_out_file, size);
1818 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
1820 void
1821 assemble_align (int align)
1823 if (align > BITS_PER_UNIT)
1825 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1829 /* Assemble a string constant with the specified C string as contents. */
1831 void
1832 assemble_string (const char *p, int size)
1834 int pos = 0;
1835 int maximum = 2000;
1837 /* If the string is very long, split it up. */
1839 while (pos < size)
1841 int thissize = size - pos;
1842 if (thissize > maximum)
1843 thissize = maximum;
1845 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
1847 pos += thissize;
1848 p += thissize;
1853 /* A noswitch_section_callback for lcomm_section. */
1855 static bool
1856 emit_local (tree decl ATTRIBUTE_UNUSED,
1857 const char *name ATTRIBUTE_UNUSED,
1858 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1859 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1861 #if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL
1862 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name,
1863 size, DECL_ALIGN (decl));
1864 return true;
1865 #elif defined ASM_OUTPUT_ALIGNED_LOCAL
1866 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl));
1867 return true;
1868 #else
1869 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1870 return false;
1871 #endif
1874 /* A noswitch_section_callback for bss_noswitch_section. */
1876 #if defined ASM_OUTPUT_ALIGNED_BSS
1877 static bool
1878 emit_bss (tree decl ATTRIBUTE_UNUSED,
1879 const char *name ATTRIBUTE_UNUSED,
1880 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1881 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1883 #if defined ASM_OUTPUT_ALIGNED_BSS
1884 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size,
1885 get_variable_align (decl));
1886 return true;
1887 #endif
1889 #endif
1891 /* A noswitch_section_callback for comm_section. */
1893 static bool
1894 emit_common (tree decl ATTRIBUTE_UNUSED,
1895 const char *name ATTRIBUTE_UNUSED,
1896 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1897 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1899 #if defined ASM_OUTPUT_ALIGNED_DECL_COMMON
1900 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name,
1901 size, get_variable_align (decl));
1902 return true;
1903 #elif defined ASM_OUTPUT_ALIGNED_COMMON
1904 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size,
1905 get_variable_align (decl));
1906 return true;
1907 #else
1908 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded);
1909 return false;
1910 #endif
1913 /* A noswitch_section_callback for tls_comm_section. */
1915 static bool
1916 emit_tls_common (tree decl ATTRIBUTE_UNUSED,
1917 const char *name ATTRIBUTE_UNUSED,
1918 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1919 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1921 #ifdef ASM_OUTPUT_TLS_COMMON
1922 ASM_OUTPUT_TLS_COMMON (asm_out_file, decl, name, size);
1923 return true;
1924 #else
1925 sorry ("thread-local COMMON data not implemented");
1926 return true;
1927 #endif
1930 /* Assemble DECL given that it belongs in SECTION_NOSWITCH section SECT.
1931 NAME is the name of DECL's SYMBOL_REF. */
1933 static void
1934 assemble_noswitch_variable (tree decl, const char *name, section *sect,
1935 unsigned int align)
1937 unsigned HOST_WIDE_INT size, rounded;
1939 size = tree_to_uhwi (DECL_SIZE_UNIT (decl));
1940 rounded = size;
1942 if ((flag_sanitize & SANITIZE_ADDRESS) && asan_protect_global (decl))
1943 size += asan_red_zone_size (size);
1945 /* Don't allocate zero bytes of common,
1946 since that means "undefined external" in the linker. */
1947 if (size == 0)
1948 rounded = 1;
1950 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1951 so that each uninitialized object starts on such a boundary. */
1952 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
1953 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1954 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1956 if (!sect->noswitch.callback (decl, name, size, rounded)
1957 && (unsigned HOST_WIDE_INT) (align / BITS_PER_UNIT) > rounded)
1958 error ("requested alignment for %q+D is greater than "
1959 "implemented alignment of %wu", decl, rounded);
1962 /* A subroutine of assemble_variable. Output the label and contents of
1963 DECL, whose address is a SYMBOL_REF with name NAME. DONT_OUTPUT_DATA
1964 is as for assemble_variable. */
1966 static void
1967 assemble_variable_contents (tree decl, const char *name,
1968 bool dont_output_data)
1970 /* Do any machine/system dependent processing of the object. */
1971 #ifdef ASM_DECLARE_OBJECT_NAME
1972 last_assemble_variable_decl = decl;
1973 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
1974 #else
1975 /* Standard thing is just output label for the object. */
1976 ASM_OUTPUT_LABEL (asm_out_file, name);
1977 #endif /* ASM_DECLARE_OBJECT_NAME */
1979 if (!dont_output_data)
1981 /* Caller is supposed to use varpool_get_constructor when it wants
1982 to output the body. */
1983 gcc_assert (!in_lto_p || DECL_INITIAL (decl) != error_mark_node);
1984 if (DECL_INITIAL (decl)
1985 && DECL_INITIAL (decl) != error_mark_node
1986 && !initializer_zerop (DECL_INITIAL (decl)))
1987 /* Output the actual data. */
1988 output_constant (DECL_INITIAL (decl),
1989 tree_to_uhwi (DECL_SIZE_UNIT (decl)),
1990 get_variable_align (decl));
1991 else
1992 /* Leave space for it. */
1993 assemble_zeros (tree_to_uhwi (DECL_SIZE_UNIT (decl)));
1997 /* Assemble everything that is needed for a variable or function declaration.
1998 Not used for automatic variables, and not used for function definitions.
1999 Should not be called for variables of incomplete structure type.
2001 TOP_LEVEL is nonzero if this variable has file scope.
2002 AT_END is nonzero if this is the special handling, at end of compilation,
2003 to define things that have had only tentative definitions.
2004 DONT_OUTPUT_DATA if nonzero means don't actually output the
2005 initial value (that will be done by the caller). */
2007 void
2008 assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED,
2009 int at_end ATTRIBUTE_UNUSED, int dont_output_data)
2011 const char *name;
2012 rtx decl_rtl, symbol;
2013 section *sect;
2014 unsigned int align;
2015 bool asan_protected = false;
2017 /* This function is supposed to handle VARIABLES. Ensure we have one. */
2018 gcc_assert (TREE_CODE (decl) == VAR_DECL);
2020 /* Emulated TLS had better not get this far. */
2021 gcc_checking_assert (targetm.have_tls || !DECL_THREAD_LOCAL_P (decl));
2023 last_assemble_variable_decl = 0;
2025 /* Normally no need to say anything here for external references,
2026 since assemble_external is called by the language-specific code
2027 when a declaration is first seen. */
2029 if (DECL_EXTERNAL (decl))
2030 return;
2032 /* Do nothing for global register variables. */
2033 if (DECL_RTL_SET_P (decl) && REG_P (DECL_RTL (decl)))
2035 TREE_ASM_WRITTEN (decl) = 1;
2036 return;
2039 /* If type was incomplete when the variable was declared,
2040 see if it is complete now. */
2042 if (DECL_SIZE (decl) == 0)
2043 layout_decl (decl, 0);
2045 /* Still incomplete => don't allocate it; treat the tentative defn
2046 (which is what it must have been) as an `extern' reference. */
2048 if (!dont_output_data && DECL_SIZE (decl) == 0)
2050 error ("storage size of %q+D isn%'t known", decl);
2051 TREE_ASM_WRITTEN (decl) = 1;
2052 return;
2055 /* The first declaration of a variable that comes through this function
2056 decides whether it is global (in C, has external linkage)
2057 or local (in C, has internal linkage). So do nothing more
2058 if this function has already run. */
2060 if (TREE_ASM_WRITTEN (decl))
2061 return;
2063 /* Make sure targetm.encode_section_info is invoked before we set
2064 ASM_WRITTEN. */
2065 decl_rtl = DECL_RTL (decl);
2067 TREE_ASM_WRITTEN (decl) = 1;
2069 /* Do no output if -fsyntax-only. */
2070 if (flag_syntax_only)
2071 return;
2073 if (! dont_output_data
2074 && ! valid_constant_size_p (DECL_SIZE_UNIT (decl)))
2076 error ("size of variable %q+D is too large", decl);
2077 return;
2080 gcc_assert (MEM_P (decl_rtl));
2081 gcc_assert (GET_CODE (XEXP (decl_rtl, 0)) == SYMBOL_REF);
2082 symbol = XEXP (decl_rtl, 0);
2084 /* If this symbol belongs to the tree constant pool, output the constant
2085 if it hasn't already been written. */
2086 if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
2088 tree decl = SYMBOL_REF_DECL (symbol);
2089 if (!TREE_ASM_WRITTEN (DECL_INITIAL (decl)))
2090 output_constant_def_contents (symbol);
2091 return;
2094 app_disable ();
2096 name = XSTR (symbol, 0);
2097 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
2098 notice_global_symbol (decl);
2100 /* Compute the alignment of this data. */
2102 align_variable (decl, dont_output_data);
2104 if ((flag_sanitize & SANITIZE_ADDRESS)
2105 && asan_protect_global (decl))
2107 asan_protected = true;
2108 DECL_ALIGN (decl) = MAX (DECL_ALIGN (decl),
2109 ASAN_RED_ZONE_SIZE * BITS_PER_UNIT);
2112 set_mem_align (decl_rtl, DECL_ALIGN (decl));
2114 align = get_variable_align (decl);
2116 if (TREE_PUBLIC (decl))
2117 maybe_assemble_visibility (decl);
2119 if (DECL_PRESERVE_P (decl))
2120 targetm.asm_out.mark_decl_preserved (name);
2122 /* First make the assembler name(s) global if appropriate. */
2123 sect = get_variable_section (decl, false);
2124 if (TREE_PUBLIC (decl)
2125 && (sect->common.flags & SECTION_COMMON) == 0)
2126 globalize_decl (decl);
2128 /* Output any data that we will need to use the address of. */
2129 if (DECL_INITIAL (decl) && DECL_INITIAL (decl) != error_mark_node)
2130 output_addressed_constants (DECL_INITIAL (decl));
2132 /* dbxout.c needs to know this. */
2133 if (sect && (sect->common.flags & SECTION_CODE) != 0)
2134 DECL_IN_TEXT_SECTION (decl) = 1;
2136 /* If the decl is part of an object_block, make sure that the decl
2137 has been positioned within its block, but do not write out its
2138 definition yet. output_object_blocks will do that later. */
2139 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
2141 gcc_assert (!dont_output_data);
2142 place_block_symbol (symbol);
2144 else if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
2145 assemble_noswitch_variable (decl, name, sect, align);
2146 else
2148 /* The following bit of code ensures that vtable_map
2149 variables are not only in the comdat section, but that
2150 each variable has its own unique comdat name. If this
2151 code is removed, the variables end up in the same section
2152 with a single comdat name.
2154 FIXME: resolve_unique_section needs to deal better with
2155 decls with both DECL_SECTION_NAME and DECL_ONE_ONLY. Once
2156 that is fixed, this if-else statement can be replaced with
2157 a single call to "switch_to_section (sect)". */
2158 if (sect->named.name
2159 && (strcmp (sect->named.name, ".vtable_map_vars") == 0))
2161 #if defined (OBJECT_FORMAT_ELF)
2162 targetm.asm_out.named_section (sect->named.name,
2163 sect->named.common.flags
2164 | SECTION_LINKONCE,
2165 DECL_NAME (decl));
2166 in_section = sect;
2167 #else
2168 switch_to_section (sect);
2169 #endif
2171 else
2172 switch_to_section (sect);
2173 if (align > BITS_PER_UNIT)
2174 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
2175 assemble_variable_contents (decl, name, dont_output_data);
2176 if (asan_protected)
2178 unsigned HOST_WIDE_INT int size
2179 = tree_to_uhwi (DECL_SIZE_UNIT (decl));
2180 assemble_zeros (asan_red_zone_size (size));
2186 /* Given a function declaration (FN_DECL), this function assembles the
2187 function into the .preinit_array section. */
2189 void
2190 assemble_vtv_preinit_initializer (tree fn_decl)
2192 section *sect;
2193 unsigned flags = SECTION_WRITE;
2194 rtx symbol = XEXP (DECL_RTL (fn_decl), 0);
2196 flags |= SECTION_NOTYPE;
2197 sect = get_section (".preinit_array", flags, fn_decl);
2198 switch_to_section (sect);
2199 assemble_addr_to_section (symbol, sect);
2202 /* Return 1 if type TYPE contains any pointers. */
2204 static int
2205 contains_pointers_p (tree type)
2207 switch (TREE_CODE (type))
2209 case POINTER_TYPE:
2210 case REFERENCE_TYPE:
2211 /* I'm not sure whether OFFSET_TYPE needs this treatment,
2212 so I'll play safe and return 1. */
2213 case OFFSET_TYPE:
2214 return 1;
2216 case RECORD_TYPE:
2217 case UNION_TYPE:
2218 case QUAL_UNION_TYPE:
2220 tree fields;
2221 /* For a type that has fields, see if the fields have pointers. */
2222 for (fields = TYPE_FIELDS (type); fields; fields = DECL_CHAIN (fields))
2223 if (TREE_CODE (fields) == FIELD_DECL
2224 && contains_pointers_p (TREE_TYPE (fields)))
2225 return 1;
2226 return 0;
2229 case ARRAY_TYPE:
2230 /* An array type contains pointers if its element type does. */
2231 return contains_pointers_p (TREE_TYPE (type));
2233 default:
2234 return 0;
2238 /* We delay assemble_external processing until
2239 the compilation unit is finalized. This is the best we can do for
2240 right now (i.e. stage 3 of GCC 4.0) - the right thing is to delay
2241 it all the way to final. See PR 17982 for further discussion. */
2242 static GTY(()) tree pending_assemble_externals;
2244 #ifdef ASM_OUTPUT_EXTERNAL
2245 /* Some targets delay some output to final using TARGET_ASM_FILE_END.
2246 As a result, assemble_external can be called after the list of externals
2247 is processed and the pointer set destroyed. */
2248 static bool pending_assemble_externals_processed;
2250 /* Avoid O(external_decls**2) lookups in the pending_assemble_externals
2251 TREE_LIST in assemble_external. */
2252 static hash_set<tree> *pending_assemble_externals_set;
2254 /* True if DECL is a function decl for which no out-of-line copy exists.
2255 It is assumed that DECL's assembler name has been set. */
2257 static bool
2258 incorporeal_function_p (tree decl)
2260 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
2262 const char *name;
2264 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
2265 && (DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA
2266 || DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA_WITH_ALIGN))
2267 return true;
2269 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
2270 /* Atomic or sync builtins which have survived this far will be
2271 resolved externally and therefore are not incorporeal. */
2272 if (strncmp (name, "__builtin_", 10) == 0)
2273 return true;
2275 return false;
2278 /* Actually do the tests to determine if this is necessary, and invoke
2279 ASM_OUTPUT_EXTERNAL. */
2280 static void
2281 assemble_external_real (tree decl)
2283 rtx rtl = DECL_RTL (decl);
2285 if (MEM_P (rtl) && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
2286 && !SYMBOL_REF_USED (XEXP (rtl, 0))
2287 && !incorporeal_function_p (decl))
2289 /* Some systems do require some output. */
2290 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
2291 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
2294 #endif
2296 void
2297 process_pending_assemble_externals (void)
2299 #ifdef ASM_OUTPUT_EXTERNAL
2300 tree list;
2301 for (list = pending_assemble_externals; list; list = TREE_CHAIN (list))
2302 assemble_external_real (TREE_VALUE (list));
2304 pending_assemble_externals = 0;
2305 pending_assemble_externals_processed = true;
2306 delete pending_assemble_externals_set;
2307 #endif
2310 /* This TREE_LIST contains any weak symbol declarations waiting
2311 to be emitted. */
2312 static GTY(()) tree weak_decls;
2314 /* Output something to declare an external symbol to the assembler,
2315 and qualifiers such as weakness. (Most assemblers don't need
2316 extern declaration, so we normally output nothing.) Do nothing if
2317 DECL is not external. */
2319 void
2320 assemble_external (tree decl ATTRIBUTE_UNUSED)
2322 /* Make sure that the ASM_OUT_FILE is open.
2323 If it's not, we should not be calling this function. */
2324 gcc_assert (asm_out_file);
2326 /* In a perfect world, the following condition would be true.
2327 Sadly, the Java and Go front ends emit assembly *from the front end*,
2328 bypassing the call graph. See PR52739. Fix before GCC 4.8. */
2329 #if 0
2330 /* This function should only be called if we are expanding, or have
2331 expanded, to RTL.
2332 Ideally, only final.c would be calling this function, but it is
2333 not clear whether that would break things somehow. See PR 17982
2334 for further discussion. */
2335 gcc_assert (cgraph_state == CGRAPH_STATE_EXPANSION
2336 || cgraph_state == CGRAPH_STATE_FINISHED);
2337 #endif
2339 if (!DECL_P (decl) || !DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl))
2340 return;
2342 /* We want to output annotation for weak and external symbols at
2343 very last to check if they are references or not. */
2345 if (TARGET_SUPPORTS_WEAK
2346 && DECL_WEAK (decl)
2347 /* TREE_STATIC is a weird and abused creature which is not
2348 generally the right test for whether an entity has been
2349 locally emitted, inlined or otherwise not-really-extern, but
2350 for declarations that can be weak, it happens to be
2351 match. */
2352 && !TREE_STATIC (decl)
2353 && lookup_attribute ("weak", DECL_ATTRIBUTES (decl))
2354 && value_member (decl, weak_decls) == NULL_TREE)
2355 weak_decls = tree_cons (NULL, decl, weak_decls);
2357 #ifdef ASM_OUTPUT_EXTERNAL
2358 if (pending_assemble_externals_processed)
2360 assemble_external_real (decl);
2361 return;
2364 if (! pending_assemble_externals_set->add (decl))
2365 pending_assemble_externals = tree_cons (NULL, decl,
2366 pending_assemble_externals);
2367 #endif
2370 /* Similar, for calling a library function FUN. */
2372 void
2373 assemble_external_libcall (rtx fun)
2375 /* Declare library function name external when first used, if nec. */
2376 if (! SYMBOL_REF_USED (fun))
2378 SYMBOL_REF_USED (fun) = 1;
2379 targetm.asm_out.external_libcall (fun);
2383 /* Assemble a label named NAME. */
2385 void
2386 assemble_label (FILE *file, const char *name)
2388 ASM_OUTPUT_LABEL (file, name);
2391 /* Set the symbol_referenced flag for ID. */
2392 void
2393 mark_referenced (tree id)
2395 TREE_SYMBOL_REFERENCED (id) = 1;
2398 /* Set the symbol_referenced flag for DECL and notify callgraph. */
2399 void
2400 mark_decl_referenced (tree decl)
2402 if (TREE_CODE (decl) == FUNCTION_DECL)
2404 /* Extern inline functions don't become needed when referenced.
2405 If we know a method will be emitted in other TU and no new
2406 functions can be marked reachable, just use the external
2407 definition. */
2408 struct cgraph_node *node = cgraph_node::get_create (decl);
2409 if (!DECL_EXTERNAL (decl)
2410 && !node->definition)
2411 node->mark_force_output ();
2413 else if (TREE_CODE (decl) == VAR_DECL)
2415 varpool_node *node = varpool_node::get_create (decl);
2416 /* C++ frontend use mark_decl_references to force COMDAT variables
2417 to be output that might appear dead otherwise. */
2418 node->force_output = true;
2420 /* else do nothing - we can get various sorts of CST nodes here,
2421 which do not need to be marked. */
2425 /* Follow the IDENTIFIER_TRANSPARENT_ALIAS chain starting at *ALIAS
2426 until we find an identifier that is not itself a transparent alias.
2427 Modify the alias passed to it by reference (and all aliases on the
2428 way to the ultimate target), such that they do not have to be
2429 followed again, and return the ultimate target of the alias
2430 chain. */
2432 static inline tree
2433 ultimate_transparent_alias_target (tree *alias)
2435 tree target = *alias;
2437 if (IDENTIFIER_TRANSPARENT_ALIAS (target))
2439 gcc_assert (TREE_CHAIN (target));
2440 target = ultimate_transparent_alias_target (&TREE_CHAIN (target));
2441 gcc_assert (! IDENTIFIER_TRANSPARENT_ALIAS (target)
2442 && ! TREE_CHAIN (target));
2443 *alias = target;
2446 return target;
2449 /* Output to FILE (an assembly file) a reference to NAME. If NAME
2450 starts with a *, the rest of NAME is output verbatim. Otherwise
2451 NAME is transformed in a target-specific way (usually by the
2452 addition of an underscore). */
2454 void
2455 assemble_name_raw (FILE *file, const char *name)
2457 if (name[0] == '*')
2458 fputs (&name[1], file);
2459 else
2460 ASM_OUTPUT_LABELREF (file, name);
2463 /* Like assemble_name_raw, but should be used when NAME might refer to
2464 an entity that is also represented as a tree (like a function or
2465 variable). If NAME does refer to such an entity, that entity will
2466 be marked as referenced. */
2468 void
2469 assemble_name (FILE *file, const char *name)
2471 const char *real_name;
2472 tree id;
2474 real_name = targetm.strip_name_encoding (name);
2476 id = maybe_get_identifier (real_name);
2477 if (id)
2479 tree id_orig = id;
2481 mark_referenced (id);
2482 ultimate_transparent_alias_target (&id);
2483 if (id != id_orig)
2484 name = IDENTIFIER_POINTER (id);
2485 gcc_assert (! TREE_CHAIN (id));
2488 assemble_name_raw (file, name);
2491 /* Allocate SIZE bytes writable static space with a gensym name
2492 and return an RTX to refer to its address. */
2495 assemble_static_space (unsigned HOST_WIDE_INT size)
2497 char name[12];
2498 const char *namestring;
2499 rtx x;
2501 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
2502 ++const_labelno;
2503 namestring = ggc_strdup (name);
2505 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
2506 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL;
2508 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
2509 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
2510 BIGGEST_ALIGNMENT);
2511 #else
2512 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
2513 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
2514 #else
2516 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
2517 so that each uninitialized object starts on such a boundary. */
2518 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */
2519 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED
2520 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
2521 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
2522 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
2523 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
2525 #endif
2526 #endif
2527 return x;
2530 /* Assemble the static constant template for function entry trampolines.
2531 This is done at most once per compilation.
2532 Returns an RTX for the address of the template. */
2534 static GTY(()) rtx initial_trampoline;
2537 assemble_trampoline_template (void)
2539 char label[256];
2540 const char *name;
2541 int align;
2542 rtx symbol;
2544 gcc_assert (targetm.asm_out.trampoline_template != NULL);
2546 if (initial_trampoline)
2547 return initial_trampoline;
2549 /* By default, put trampoline templates in read-only data section. */
2551 #ifdef TRAMPOLINE_SECTION
2552 switch_to_section (TRAMPOLINE_SECTION);
2553 #else
2554 switch_to_section (readonly_data_section);
2555 #endif
2557 /* Write the assembler code to define one. */
2558 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
2559 if (align > 0)
2560 ASM_OUTPUT_ALIGN (asm_out_file, align);
2562 targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0);
2563 targetm.asm_out.trampoline_template (asm_out_file);
2565 /* Record the rtl to refer to it. */
2566 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
2567 name = ggc_strdup (label);
2568 symbol = gen_rtx_SYMBOL_REF (Pmode, name);
2569 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2571 initial_trampoline = gen_const_mem (BLKmode, symbol);
2572 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
2573 set_mem_size (initial_trampoline, TRAMPOLINE_SIZE);
2575 return initial_trampoline;
2578 /* A and B are either alignments or offsets. Return the minimum alignment
2579 that may be assumed after adding the two together. */
2581 static inline unsigned
2582 min_align (unsigned int a, unsigned int b)
2584 return (a | b) & -(a | b);
2587 /* Return the assembler directive for creating a given kind of integer
2588 object. SIZE is the number of bytes in the object and ALIGNED_P
2589 indicates whether it is known to be aligned. Return NULL if the
2590 assembly dialect has no such directive.
2592 The returned string should be printed at the start of a new line and
2593 be followed immediately by the object's initial value. */
2595 const char *
2596 integer_asm_op (int size, int aligned_p)
2598 struct asm_int_op *ops;
2600 if (aligned_p)
2601 ops = &targetm.asm_out.aligned_op;
2602 else
2603 ops = &targetm.asm_out.unaligned_op;
2605 switch (size)
2607 case 1:
2608 return targetm.asm_out.byte_op;
2609 case 2:
2610 return ops->hi;
2611 case 4:
2612 return ops->si;
2613 case 8:
2614 return ops->di;
2615 case 16:
2616 return ops->ti;
2617 default:
2618 return NULL;
2622 /* Use directive OP to assemble an integer object X. Print OP at the
2623 start of the line, followed immediately by the value of X. */
2625 void
2626 assemble_integer_with_op (const char *op, rtx x)
2628 fputs (op, asm_out_file);
2629 output_addr_const (asm_out_file, x);
2630 fputc ('\n', asm_out_file);
2633 /* The default implementation of the asm_out.integer target hook. */
2635 bool
2636 default_assemble_integer (rtx x ATTRIBUTE_UNUSED,
2637 unsigned int size ATTRIBUTE_UNUSED,
2638 int aligned_p ATTRIBUTE_UNUSED)
2640 const char *op = integer_asm_op (size, aligned_p);
2641 /* Avoid GAS bugs for large values. Specifically negative values whose
2642 absolute value fits in a bfd_vma, but not in a bfd_signed_vma. */
2643 if (size > UNITS_PER_WORD && size > POINTER_SIZE / BITS_PER_UNIT)
2644 return false;
2645 return op && (assemble_integer_with_op (op, x), true);
2648 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
2649 the alignment of the integer in bits. Return 1 if we were able to output
2650 the constant, otherwise 0. We must be able to output the constant,
2651 if FORCE is nonzero. */
2653 bool
2654 assemble_integer (rtx x, unsigned int size, unsigned int align, int force)
2656 int aligned_p;
2658 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT));
2660 /* See if the target hook can handle this kind of object. */
2661 if (targetm.asm_out.integer (x, size, aligned_p))
2662 return true;
2664 /* If the object is a multi-byte one, try splitting it up. Split
2665 it into words it if is multi-word, otherwise split it into bytes. */
2666 if (size > 1)
2668 enum machine_mode omode, imode;
2669 unsigned int subalign;
2670 unsigned int subsize, i;
2671 enum mode_class mclass;
2673 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1;
2674 subalign = MIN (align, subsize * BITS_PER_UNIT);
2675 if (GET_CODE (x) == CONST_FIXED)
2676 mclass = GET_MODE_CLASS (GET_MODE (x));
2677 else
2678 mclass = MODE_INT;
2680 omode = mode_for_size (subsize * BITS_PER_UNIT, mclass, 0);
2681 imode = mode_for_size (size * BITS_PER_UNIT, mclass, 0);
2683 for (i = 0; i < size; i += subsize)
2685 rtx partial = simplify_subreg (omode, x, imode, i);
2686 if (!partial || !assemble_integer (partial, subsize, subalign, 0))
2687 break;
2689 if (i == size)
2690 return true;
2692 /* If we've printed some of it, but not all of it, there's no going
2693 back now. */
2694 gcc_assert (!i);
2697 gcc_assert (!force);
2699 return false;
2702 void
2703 assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align)
2705 long data[4] = {0, 0, 0, 0};
2706 int i;
2707 int bitsize, nelts, nunits, units_per;
2709 /* This is hairy. We have a quantity of known size. real_to_target
2710 will put it into an array of *host* longs, 32 bits per element
2711 (even if long is more than 32 bits). We need to determine the
2712 number of array elements that are occupied (nelts) and the number
2713 of *target* min-addressable units that will be occupied in the
2714 object file (nunits). We cannot assume that 32 divides the
2715 mode's bitsize (size * BITS_PER_UNIT) evenly.
2717 size * BITS_PER_UNIT is used here to make sure that padding bits
2718 (which might appear at either end of the value; real_to_target
2719 will include the padding bits in its output array) are included. */
2721 nunits = GET_MODE_SIZE (mode);
2722 bitsize = nunits * BITS_PER_UNIT;
2723 nelts = CEIL (bitsize, 32);
2724 units_per = 32 / BITS_PER_UNIT;
2726 real_to_target (data, &d, mode);
2728 /* Put out the first word with the specified alignment. */
2729 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1);
2730 nunits -= units_per;
2732 /* Subsequent words need only 32-bit alignment. */
2733 align = min_align (align, 32);
2735 for (i = 1; i < nelts; i++)
2737 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1);
2738 nunits -= units_per;
2742 /* Given an expression EXP with a constant value,
2743 reduce it to the sum of an assembler symbol and an integer.
2744 Store them both in the structure *VALUE.
2745 EXP must be reducible. */
2747 struct addr_const {
2748 rtx base;
2749 HOST_WIDE_INT offset;
2752 static void
2753 decode_addr_const (tree exp, struct addr_const *value)
2755 tree target = TREE_OPERAND (exp, 0);
2756 int offset = 0;
2757 rtx x;
2759 while (1)
2761 if (TREE_CODE (target) == COMPONENT_REF
2762 && tree_fits_shwi_p (byte_position (TREE_OPERAND (target, 1))))
2764 offset += int_byte_position (TREE_OPERAND (target, 1));
2765 target = TREE_OPERAND (target, 0);
2767 else if (TREE_CODE (target) == ARRAY_REF
2768 || TREE_CODE (target) == ARRAY_RANGE_REF)
2770 offset += (tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (target)))
2771 * tree_to_shwi (TREE_OPERAND (target, 1)));
2772 target = TREE_OPERAND (target, 0);
2774 else if (TREE_CODE (target) == MEM_REF
2775 && TREE_CODE (TREE_OPERAND (target, 0)) == ADDR_EXPR)
2777 offset += mem_ref_offset (target).to_short_addr ();
2778 target = TREE_OPERAND (TREE_OPERAND (target, 0), 0);
2780 else if (TREE_CODE (target) == INDIRECT_REF
2781 && TREE_CODE (TREE_OPERAND (target, 0)) == NOP_EXPR
2782 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (target, 0), 0))
2783 == ADDR_EXPR)
2784 target = TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (target, 0), 0), 0);
2785 else
2786 break;
2789 switch (TREE_CODE (target))
2791 case VAR_DECL:
2792 case FUNCTION_DECL:
2793 x = DECL_RTL (target);
2794 break;
2796 case LABEL_DECL:
2797 x = gen_rtx_MEM (FUNCTION_MODE,
2798 gen_rtx_LABEL_REF (Pmode, force_label_rtx (target)));
2799 break;
2801 case REAL_CST:
2802 case FIXED_CST:
2803 case STRING_CST:
2804 case COMPLEX_CST:
2805 case CONSTRUCTOR:
2806 case INTEGER_CST:
2807 x = output_constant_def (target, 1);
2808 break;
2810 default:
2811 gcc_unreachable ();
2814 gcc_assert (MEM_P (x));
2815 x = XEXP (x, 0);
2817 value->base = x;
2818 value->offset = offset;
2822 static GTY((param_is (struct constant_descriptor_tree)))
2823 htab_t const_desc_htab;
2825 static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int);
2827 /* Constant pool accessor function. */
2829 htab_t
2830 constant_pool_htab (void)
2832 return const_desc_htab;
2835 /* Compute a hash code for a constant expression. */
2837 static hashval_t
2838 const_desc_hash (const void *ptr)
2840 return ((const struct constant_descriptor_tree *)ptr)->hash;
2843 static hashval_t
2844 const_hash_1 (const tree exp)
2846 const char *p;
2847 hashval_t hi;
2848 int len, i;
2849 enum tree_code code = TREE_CODE (exp);
2851 /* Either set P and LEN to the address and len of something to hash and
2852 exit the switch or return a value. */
2854 switch (code)
2856 case INTEGER_CST:
2857 p = (char *) &TREE_INT_CST_ELT (exp, 0);
2858 len = TREE_INT_CST_NUNITS (exp) * sizeof (HOST_WIDE_INT);
2859 break;
2861 case REAL_CST:
2862 return real_hash (TREE_REAL_CST_PTR (exp));
2864 case FIXED_CST:
2865 return fixed_hash (TREE_FIXED_CST_PTR (exp));
2867 case STRING_CST:
2868 p = TREE_STRING_POINTER (exp);
2869 len = TREE_STRING_LENGTH (exp);
2870 break;
2872 case COMPLEX_CST:
2873 return (const_hash_1 (TREE_REALPART (exp)) * 5
2874 + const_hash_1 (TREE_IMAGPART (exp)));
2876 case VECTOR_CST:
2878 unsigned i;
2880 hi = 7 + VECTOR_CST_NELTS (exp);
2882 for (i = 0; i < VECTOR_CST_NELTS (exp); ++i)
2883 hi = hi * 563 + const_hash_1 (VECTOR_CST_ELT (exp, i));
2885 return hi;
2888 case CONSTRUCTOR:
2890 unsigned HOST_WIDE_INT idx;
2891 tree value;
2893 hi = 5 + int_size_in_bytes (TREE_TYPE (exp));
2895 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, value)
2896 if (value)
2897 hi = hi * 603 + const_hash_1 (value);
2899 return hi;
2902 case ADDR_EXPR:
2903 case FDESC_EXPR:
2905 struct addr_const value;
2907 decode_addr_const (exp, &value);
2908 switch (GET_CODE (value.base))
2910 case SYMBOL_REF:
2911 /* Don't hash the address of the SYMBOL_REF;
2912 only use the offset and the symbol name. */
2913 hi = value.offset;
2914 p = XSTR (value.base, 0);
2915 for (i = 0; p[i] != 0; i++)
2916 hi = ((hi * 613) + (unsigned) (p[i]));
2917 break;
2919 case LABEL_REF:
2920 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2921 break;
2923 default:
2924 gcc_unreachable ();
2927 return hi;
2929 case PLUS_EXPR:
2930 case POINTER_PLUS_EXPR:
2931 case MINUS_EXPR:
2932 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9
2933 + const_hash_1 (TREE_OPERAND (exp, 1)));
2935 CASE_CONVERT:
2936 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2;
2938 default:
2939 /* A language specific constant. Just hash the code. */
2940 return code;
2943 /* Compute hashing function. */
2944 hi = len;
2945 for (i = 0; i < len; i++)
2946 hi = ((hi * 613) + (unsigned) (p[i]));
2948 return hi;
2951 /* Wrapper of compare_constant, for the htab interface. */
2952 static int
2953 const_desc_eq (const void *p1, const void *p2)
2955 const struct constant_descriptor_tree *const c1
2956 = (const struct constant_descriptor_tree *) p1;
2957 const struct constant_descriptor_tree *const c2
2958 = (const struct constant_descriptor_tree *) p2;
2959 if (c1->hash != c2->hash)
2960 return 0;
2961 return compare_constant (c1->value, c2->value);
2964 /* Compare t1 and t2, and return 1 only if they are known to result in
2965 the same bit pattern on output. */
2967 static int
2968 compare_constant (const tree t1, const tree t2)
2970 enum tree_code typecode;
2972 if (t1 == NULL_TREE)
2973 return t2 == NULL_TREE;
2974 if (t2 == NULL_TREE)
2975 return 0;
2977 if (TREE_CODE (t1) != TREE_CODE (t2))
2978 return 0;
2980 switch (TREE_CODE (t1))
2982 case INTEGER_CST:
2983 /* Integer constants are the same only if the same width of type. */
2984 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2985 return 0;
2986 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2987 return 0;
2988 return tree_int_cst_equal (t1, t2);
2990 case REAL_CST:
2991 /* Real constants are the same only if the same width of type. */
2992 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2993 return 0;
2995 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2997 case FIXED_CST:
2998 /* Fixed constants are the same only if the same width of type. */
2999 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
3000 return 0;
3002 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (t1), TREE_FIXED_CST (t2));
3004 case STRING_CST:
3005 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
3006 return 0;
3008 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
3009 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
3010 TREE_STRING_LENGTH (t1)));
3012 case COMPLEX_CST:
3013 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2))
3014 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2)));
3016 case VECTOR_CST:
3018 unsigned i;
3020 if (VECTOR_CST_NELTS (t1) != VECTOR_CST_NELTS (t2))
3021 return 0;
3023 for (i = 0; i < VECTOR_CST_NELTS (t1); ++i)
3024 if (!compare_constant (VECTOR_CST_ELT (t1, i),
3025 VECTOR_CST_ELT (t2, i)))
3026 return 0;
3028 return 1;
3031 case CONSTRUCTOR:
3033 vec<constructor_elt, va_gc> *v1, *v2;
3034 unsigned HOST_WIDE_INT idx;
3036 typecode = TREE_CODE (TREE_TYPE (t1));
3037 if (typecode != TREE_CODE (TREE_TYPE (t2)))
3038 return 0;
3040 if (typecode == ARRAY_TYPE)
3042 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1));
3043 /* For arrays, check that the sizes all match. */
3044 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))
3045 || size_1 == -1
3046 || size_1 != int_size_in_bytes (TREE_TYPE (t2)))
3047 return 0;
3049 else
3051 /* For record and union constructors, require exact type
3052 equality. */
3053 if (TREE_TYPE (t1) != TREE_TYPE (t2))
3054 return 0;
3057 v1 = CONSTRUCTOR_ELTS (t1);
3058 v2 = CONSTRUCTOR_ELTS (t2);
3059 if (vec_safe_length (v1) != vec_safe_length (v2))
3060 return 0;
3062 for (idx = 0; idx < vec_safe_length (v1); ++idx)
3064 constructor_elt *c1 = &(*v1)[idx];
3065 constructor_elt *c2 = &(*v2)[idx];
3067 /* Check that each value is the same... */
3068 if (!compare_constant (c1->value, c2->value))
3069 return 0;
3070 /* ... and that they apply to the same fields! */
3071 if (typecode == ARRAY_TYPE)
3073 if (!compare_constant (c1->index, c2->index))
3074 return 0;
3076 else
3078 if (c1->index != c2->index)
3079 return 0;
3083 return 1;
3086 case ADDR_EXPR:
3087 case FDESC_EXPR:
3089 struct addr_const value1, value2;
3090 enum rtx_code code;
3091 int ret;
3093 decode_addr_const (t1, &value1);
3094 decode_addr_const (t2, &value2);
3096 if (value1.offset != value2.offset)
3097 return 0;
3099 code = GET_CODE (value1.base);
3100 if (code != GET_CODE (value2.base))
3101 return 0;
3103 switch (code)
3105 case SYMBOL_REF:
3106 ret = (strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0);
3107 break;
3109 case LABEL_REF:
3110 ret = (CODE_LABEL_NUMBER (XEXP (value1.base, 0))
3111 == CODE_LABEL_NUMBER (XEXP (value2.base, 0)));
3112 break;
3114 default:
3115 gcc_unreachable ();
3117 return ret;
3120 case PLUS_EXPR:
3121 case POINTER_PLUS_EXPR:
3122 case MINUS_EXPR:
3123 case RANGE_EXPR:
3124 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
3125 && compare_constant (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
3127 CASE_CONVERT:
3128 case VIEW_CONVERT_EXPR:
3129 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3131 default:
3132 return 0;
3135 gcc_unreachable ();
3138 /* Return the section into which constant EXP should be placed. */
3140 static section *
3141 get_constant_section (tree exp, unsigned int align)
3143 return targetm.asm_out.select_section (exp,
3144 compute_reloc_for_constant (exp),
3145 align);
3148 /* Return the size of constant EXP in bytes. */
3150 static HOST_WIDE_INT
3151 get_constant_size (tree exp)
3153 HOST_WIDE_INT size;
3155 size = int_size_in_bytes (TREE_TYPE (exp));
3156 if (TREE_CODE (exp) == STRING_CST)
3157 size = MAX (TREE_STRING_LENGTH (exp), size);
3158 return size;
3161 /* Subroutine of output_constant_def:
3162 No constant equal to EXP is known to have been output.
3163 Make a constant descriptor to enter EXP in the hash table.
3164 Assign the label number and construct RTL to refer to the
3165 constant's location in memory.
3166 Caller is responsible for updating the hash table. */
3168 static struct constant_descriptor_tree *
3169 build_constant_desc (tree exp)
3171 struct constant_descriptor_tree *desc;
3172 rtx symbol, rtl;
3173 char label[256];
3174 int labelno;
3175 tree decl;
3177 desc = ggc_alloc<constant_descriptor_tree> ();
3178 desc->value = exp;
3180 /* Create a string containing the label name, in LABEL. */
3181 labelno = const_labelno++;
3182 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno);
3184 /* Construct the VAR_DECL associated with the constant. */
3185 decl = build_decl (UNKNOWN_LOCATION, VAR_DECL, get_identifier (label),
3186 TREE_TYPE (exp));
3187 DECL_ARTIFICIAL (decl) = 1;
3188 DECL_IGNORED_P (decl) = 1;
3189 TREE_READONLY (decl) = 1;
3190 TREE_STATIC (decl) = 1;
3191 TREE_ADDRESSABLE (decl) = 1;
3192 /* We don't set the RTL yet as this would cause varpool to assume that the
3193 variable is referenced. Moreover, it would just be dropped in LTO mode.
3194 Instead we set the flag that will be recognized in make_decl_rtl. */
3195 DECL_IN_CONSTANT_POOL (decl) = 1;
3196 DECL_INITIAL (decl) = desc->value;
3197 /* ??? CONSTANT_ALIGNMENT hasn't been updated for vector types on most
3198 architectures so use DATA_ALIGNMENT as well, except for strings. */
3199 if (TREE_CODE (exp) == STRING_CST)
3201 #ifdef CONSTANT_ALIGNMENT
3202 DECL_ALIGN (decl) = CONSTANT_ALIGNMENT (exp, DECL_ALIGN (decl));
3203 #endif
3205 else
3206 align_variable (decl, 0);
3208 /* Now construct the SYMBOL_REF and the MEM. */
3209 if (use_object_blocks_p ())
3211 section *sect = get_constant_section (exp, DECL_ALIGN (decl));
3212 symbol = create_block_symbol (ggc_strdup (label),
3213 get_block_for_section (sect), -1);
3215 else
3216 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3217 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3218 SET_SYMBOL_REF_DECL (symbol, decl);
3219 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3221 rtl = gen_const_mem (TYPE_MODE (TREE_TYPE (exp)), symbol);
3222 set_mem_attributes (rtl, exp, 1);
3223 set_mem_alias_set (rtl, 0);
3224 set_mem_alias_set (rtl, const_alias_set);
3226 /* We cannot share RTX'es in pool entries.
3227 Mark this piece of RTL as required for unsharing. */
3228 RTX_FLAG (rtl, used) = 1;
3230 /* Set flags or add text to the name to record information, such as
3231 that it is a local symbol. If the name is changed, the macro
3232 ASM_OUTPUT_LABELREF will have to know how to strip this
3233 information. This call might invalidate our local variable
3234 SYMBOL; we can't use it afterward. */
3235 targetm.encode_section_info (exp, rtl, true);
3237 desc->rtl = rtl;
3239 return desc;
3242 /* Return an rtx representing a reference to constant data in memory
3243 for the constant expression EXP.
3245 If assembler code for such a constant has already been output,
3246 return an rtx to refer to it.
3247 Otherwise, output such a constant in memory
3248 and generate an rtx for it.
3250 If DEFER is nonzero, this constant can be deferred and output only
3251 if referenced in the function after all optimizations.
3253 `const_desc_table' records which constants already have label strings. */
3256 output_constant_def (tree exp, int defer)
3258 struct constant_descriptor_tree *desc;
3259 struct constant_descriptor_tree key;
3260 void **loc;
3262 /* Look up EXP in the table of constant descriptors. If we didn't find
3263 it, create a new one. */
3264 key.value = exp;
3265 key.hash = const_hash_1 (exp);
3266 loc = htab_find_slot_with_hash (const_desc_htab, &key, key.hash, INSERT);
3268 desc = (struct constant_descriptor_tree *) *loc;
3269 if (desc == 0)
3271 desc = build_constant_desc (exp);
3272 desc->hash = key.hash;
3273 *loc = desc;
3276 maybe_output_constant_def_contents (desc, defer);
3277 return desc->rtl;
3280 /* Subroutine of output_constant_def: Decide whether or not we need to
3281 output the constant DESC now, and if so, do it. */
3282 static void
3283 maybe_output_constant_def_contents (struct constant_descriptor_tree *desc,
3284 int defer)
3286 rtx symbol = XEXP (desc->rtl, 0);
3287 tree exp = desc->value;
3289 if (flag_syntax_only)
3290 return;
3292 if (TREE_ASM_WRITTEN (exp))
3293 /* Already output; don't do it again. */
3294 return;
3296 /* We can always defer constants as long as the context allows
3297 doing so. */
3298 if (defer)
3300 /* Increment n_deferred_constants if it exists. It needs to be at
3301 least as large as the number of constants actually referred to
3302 by the function. If it's too small we'll stop looking too early
3303 and fail to emit constants; if it's too large we'll only look
3304 through the entire function when we could have stopped earlier. */
3305 if (cfun)
3306 n_deferred_constants++;
3307 return;
3310 output_constant_def_contents (symbol);
3313 /* Subroutine of output_constant_def_contents. Output the definition
3314 of constant EXP, which is pointed to by label LABEL. ALIGN is the
3315 constant's alignment in bits. */
3317 static void
3318 assemble_constant_contents (tree exp, const char *label, unsigned int align)
3320 HOST_WIDE_INT size;
3322 size = get_constant_size (exp);
3324 /* Do any machine/system dependent processing of the constant. */
3325 targetm.asm_out.declare_constant_name (asm_out_file, label, exp, size);
3327 /* Output the value of EXP. */
3328 output_constant (exp, size, align);
3331 /* We must output the constant data referred to by SYMBOL; do so. */
3333 static void
3334 output_constant_def_contents (rtx symbol)
3336 tree decl = SYMBOL_REF_DECL (symbol);
3337 tree exp = DECL_INITIAL (decl);
3338 unsigned int align;
3339 bool asan_protected = false;
3341 /* Make sure any other constants whose addresses appear in EXP
3342 are assigned label numbers. */
3343 output_addressed_constants (exp);
3345 /* We are no longer deferring this constant. */
3346 TREE_ASM_WRITTEN (decl) = TREE_ASM_WRITTEN (exp) = 1;
3348 if ((flag_sanitize & SANITIZE_ADDRESS)
3349 && TREE_CODE (exp) == STRING_CST
3350 && asan_protect_global (exp))
3352 asan_protected = true;
3353 DECL_ALIGN (decl) = MAX (DECL_ALIGN (decl),
3354 ASAN_RED_ZONE_SIZE * BITS_PER_UNIT);
3357 /* If the constant is part of an object block, make sure that the
3358 decl has been positioned within its block, but do not write out
3359 its definition yet. output_object_blocks will do that later. */
3360 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
3361 place_block_symbol (symbol);
3362 else
3364 align = DECL_ALIGN (decl);
3365 switch_to_section (get_constant_section (exp, align));
3366 if (align > BITS_PER_UNIT)
3367 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
3368 assemble_constant_contents (exp, XSTR (symbol, 0), align);
3369 if (asan_protected)
3371 HOST_WIDE_INT size = get_constant_size (exp);
3372 assemble_zeros (asan_red_zone_size (size));
3377 /* Look up EXP in the table of constant descriptors. Return the rtl
3378 if it has been emitted, else null. */
3381 lookup_constant_def (tree exp)
3383 struct constant_descriptor_tree *desc;
3384 struct constant_descriptor_tree key;
3386 key.value = exp;
3387 key.hash = const_hash_1 (exp);
3388 desc = (struct constant_descriptor_tree *)
3389 htab_find_with_hash (const_desc_htab, &key, key.hash);
3391 return (desc ? desc->rtl : NULL_RTX);
3394 /* Return a tree representing a reference to constant data in memory
3395 for the constant expression EXP.
3397 This is the counterpart of output_constant_def at the Tree level. */
3399 tree
3400 tree_output_constant_def (tree exp)
3402 struct constant_descriptor_tree *desc, key;
3403 void **loc;
3404 tree decl;
3406 /* Look up EXP in the table of constant descriptors. If we didn't find
3407 it, create a new one. */
3408 key.value = exp;
3409 key.hash = const_hash_1 (exp);
3410 loc = htab_find_slot_with_hash (const_desc_htab, &key, key.hash, INSERT);
3412 desc = (struct constant_descriptor_tree *) *loc;
3413 if (desc == 0)
3415 desc = build_constant_desc (exp);
3416 desc->hash = key.hash;
3417 *loc = desc;
3420 decl = SYMBOL_REF_DECL (XEXP (desc->rtl, 0));
3421 varpool_node::finalize_decl (decl);
3422 return decl;
3425 /* Used in the hash tables to avoid outputting the same constant
3426 twice. Unlike 'struct constant_descriptor_tree', RTX constants
3427 are output once per function, not once per file. */
3428 /* ??? Only a few targets need per-function constant pools. Most
3429 can use one per-file pool. Should add a targetm bit to tell the
3430 difference. */
3432 struct GTY(()) rtx_constant_pool {
3433 /* Pointers to first and last constant in pool, as ordered by offset. */
3434 struct constant_descriptor_rtx *first;
3435 struct constant_descriptor_rtx *last;
3437 /* Hash facility for making memory-constants from constant rtl-expressions.
3438 It is used on RISC machines where immediate integer arguments and
3439 constant addresses are restricted so that such constants must be stored
3440 in memory. */
3441 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab;
3443 /* Current offset in constant pool (does not include any
3444 machine-specific header). */
3445 HOST_WIDE_INT offset;
3448 struct GTY((chain_next ("%h.next"))) constant_descriptor_rtx {
3449 struct constant_descriptor_rtx *next;
3450 rtx mem;
3451 rtx sym;
3452 rtx constant;
3453 HOST_WIDE_INT offset;
3454 hashval_t hash;
3455 enum machine_mode mode;
3456 unsigned int align;
3457 int labelno;
3458 int mark;
3461 /* Hash and compare functions for const_rtx_htab. */
3463 static hashval_t
3464 const_desc_rtx_hash (const void *ptr)
3466 const struct constant_descriptor_rtx *const desc
3467 = (const struct constant_descriptor_rtx *) ptr;
3468 return desc->hash;
3471 static int
3472 const_desc_rtx_eq (const void *a, const void *b)
3474 const struct constant_descriptor_rtx *const x
3475 = (const struct constant_descriptor_rtx *) a;
3476 const struct constant_descriptor_rtx *const y
3477 = (const struct constant_descriptor_rtx *) b;
3479 if (x->mode != y->mode)
3480 return 0;
3481 return rtx_equal_p (x->constant, y->constant);
3484 /* This is the worker function for const_rtx_hash, called via for_each_rtx. */
3486 static int
3487 const_rtx_hash_1 (rtx *xp, void *data)
3489 unsigned HOST_WIDE_INT hwi;
3490 enum machine_mode mode;
3491 enum rtx_code code;
3492 hashval_t h, *hp;
3493 rtx x;
3494 int i;
3496 x = *xp;
3497 code = GET_CODE (x);
3498 mode = GET_MODE (x);
3499 h = (hashval_t) code * 1048573 + mode;
3501 switch (code)
3503 case CONST_INT:
3504 hwi = INTVAL (x);
3506 fold_hwi:
3508 int shift = sizeof (hashval_t) * CHAR_BIT;
3509 const int n = sizeof (HOST_WIDE_INT) / sizeof (hashval_t);
3511 h ^= (hashval_t) hwi;
3512 for (i = 1; i < n; ++i)
3514 hwi >>= shift;
3515 h ^= (hashval_t) hwi;
3518 break;
3520 case CONST_WIDE_INT:
3521 hwi = GET_MODE_PRECISION (mode);
3523 for (i = 0; i < CONST_WIDE_INT_NUNITS (x); i++)
3524 hwi ^= CONST_WIDE_INT_ELT (x, i);
3525 goto fold_hwi;
3528 case CONST_DOUBLE:
3529 if (TARGET_SUPPORTS_WIDE_INT == 0 && mode == VOIDmode)
3531 hwi = CONST_DOUBLE_LOW (x) ^ CONST_DOUBLE_HIGH (x);
3532 goto fold_hwi;
3534 else
3535 h ^= real_hash (CONST_DOUBLE_REAL_VALUE (x));
3536 break;
3538 case CONST_FIXED:
3539 h ^= fixed_hash (CONST_FIXED_VALUE (x));
3540 break;
3542 case CONST_VECTOR:
3544 int i;
3545 for (i = XVECLEN (x, 0); i-- > 0; )
3546 h = h * 251 + const_rtx_hash_1 (&XVECEXP (x, 0, i), data);
3548 break;
3550 case SYMBOL_REF:
3551 h ^= htab_hash_string (XSTR (x, 0));
3552 break;
3554 case LABEL_REF:
3555 h = h * 251 + CODE_LABEL_NUMBER (XEXP (x, 0));
3556 break;
3558 case UNSPEC:
3559 case UNSPEC_VOLATILE:
3560 h = h * 251 + XINT (x, 1);
3561 break;
3563 default:
3564 break;
3567 hp = (hashval_t *) data;
3568 *hp = *hp * 509 + h;
3569 return 0;
3572 /* Compute a hash value for X, which should be a constant. */
3574 static hashval_t
3575 const_rtx_hash (rtx x)
3577 hashval_t h = 0;
3578 for_each_rtx (&x, const_rtx_hash_1, &h);
3579 return h;
3583 /* Create and return a new rtx constant pool. */
3585 static struct rtx_constant_pool *
3586 create_constant_pool (void)
3588 struct rtx_constant_pool *pool;
3590 pool = ggc_alloc<rtx_constant_pool> ();
3591 pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash,
3592 const_desc_rtx_eq, NULL);
3593 pool->first = NULL;
3594 pool->last = NULL;
3595 pool->offset = 0;
3596 return pool;
3599 /* Initialize constant pool hashing for a new function. */
3601 void
3602 init_varasm_status (void)
3604 crtl->varasm.pool = create_constant_pool ();
3605 crtl->varasm.deferred_constants = 0;
3608 /* Given a MINUS expression, simplify it if both sides
3609 include the same symbol. */
3612 simplify_subtraction (rtx x)
3614 rtx r = simplify_rtx (x);
3615 return r ? r : x;
3618 /* Given a constant rtx X, make (or find) a memory constant for its value
3619 and return a MEM rtx to refer to it in memory. */
3622 force_const_mem (enum machine_mode mode, rtx x)
3624 struct constant_descriptor_rtx *desc, tmp;
3625 struct rtx_constant_pool *pool;
3626 char label[256];
3627 rtx def, symbol;
3628 hashval_t hash;
3629 unsigned int align;
3630 void **slot;
3632 /* If we're not allowed to drop X into the constant pool, don't. */
3633 if (targetm.cannot_force_const_mem (mode, x))
3634 return NULL_RTX;
3636 /* Record that this function has used a constant pool entry. */
3637 crtl->uses_const_pool = 1;
3639 /* Decide which pool to use. */
3640 pool = (targetm.use_blocks_for_constant_p (mode, x)
3641 ? shared_constant_pool
3642 : crtl->varasm.pool);
3644 /* Lookup the value in the hashtable. */
3645 tmp.constant = x;
3646 tmp.mode = mode;
3647 hash = const_rtx_hash (x);
3648 slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT);
3649 desc = (struct constant_descriptor_rtx *) *slot;
3651 /* If the constant was already present, return its memory. */
3652 if (desc)
3653 return copy_rtx (desc->mem);
3655 /* Otherwise, create a new descriptor. */
3656 desc = ggc_alloc<constant_descriptor_rtx> ();
3657 *slot = desc;
3659 /* Align the location counter as required by EXP's data type. */
3660 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode);
3661 #ifdef CONSTANT_ALIGNMENT
3663 tree type = lang_hooks.types.type_for_mode (mode, 0);
3664 if (type != NULL_TREE)
3665 align = CONSTANT_ALIGNMENT (make_tree (type, x), align);
3667 #endif
3669 pool->offset += (align / BITS_PER_UNIT) - 1;
3670 pool->offset &= ~ ((align / BITS_PER_UNIT) - 1);
3672 desc->next = NULL;
3673 desc->constant = copy_rtx (tmp.constant);
3674 desc->offset = pool->offset;
3675 desc->hash = hash;
3676 desc->mode = mode;
3677 desc->align = align;
3678 desc->labelno = const_labelno;
3679 desc->mark = 0;
3681 pool->offset += GET_MODE_SIZE (mode);
3682 if (pool->last)
3683 pool->last->next = desc;
3684 else
3685 pool->first = pool->last = desc;
3686 pool->last = desc;
3688 /* Create a string containing the label name, in LABEL. */
3689 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
3690 ++const_labelno;
3692 /* Construct the SYMBOL_REF. Make sure to mark it as belonging to
3693 the constants pool. */
3694 if (use_object_blocks_p () && targetm.use_blocks_for_constant_p (mode, x))
3696 section *sect = targetm.asm_out.select_rtx_section (mode, x, align);
3697 symbol = create_block_symbol (ggc_strdup (label),
3698 get_block_for_section (sect), -1);
3700 else
3701 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3702 desc->sym = symbol;
3703 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3704 CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3705 SET_SYMBOL_REF_CONSTANT (symbol, desc);
3707 /* Construct the MEM. */
3708 desc->mem = def = gen_const_mem (mode, symbol);
3709 set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1);
3710 set_mem_align (def, align);
3712 /* If we're dropping a label to the constant pool, make sure we
3713 don't delete it. */
3714 if (GET_CODE (x) == LABEL_REF)
3715 LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
3717 return copy_rtx (def);
3720 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
3723 get_pool_constant (rtx addr)
3725 return SYMBOL_REF_CONSTANT (addr)->constant;
3728 /* Given a constant pool SYMBOL_REF, return the corresponding constant
3729 and whether it has been output or not. */
3732 get_pool_constant_mark (rtx addr, bool *pmarked)
3734 struct constant_descriptor_rtx *desc;
3736 desc = SYMBOL_REF_CONSTANT (addr);
3737 *pmarked = (desc->mark != 0);
3738 return desc->constant;
3741 /* Similar, return the mode. */
3743 enum machine_mode
3744 get_pool_mode (const_rtx addr)
3746 return SYMBOL_REF_CONSTANT (addr)->mode;
3749 /* Return the size of the constant pool. */
3752 get_pool_size (void)
3754 return crtl->varasm.pool->offset;
3757 /* Worker function for output_constant_pool_1. Emit assembly for X
3758 in MODE with known alignment ALIGN. */
3760 static void
3761 output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align)
3763 switch (GET_MODE_CLASS (mode))
3765 case MODE_FLOAT:
3766 case MODE_DECIMAL_FLOAT:
3768 REAL_VALUE_TYPE r;
3770 gcc_assert (CONST_DOUBLE_AS_FLOAT_P (x));
3771 REAL_VALUE_FROM_CONST_DOUBLE (r, x);
3772 assemble_real (r, mode, align);
3773 break;
3776 case MODE_INT:
3777 case MODE_PARTIAL_INT:
3778 case MODE_FRACT:
3779 case MODE_UFRACT:
3780 case MODE_ACCUM:
3781 case MODE_UACCUM:
3782 assemble_integer (x, GET_MODE_SIZE (mode), align, 1);
3783 break;
3785 case MODE_VECTOR_FLOAT:
3786 case MODE_VECTOR_INT:
3787 case MODE_VECTOR_FRACT:
3788 case MODE_VECTOR_UFRACT:
3789 case MODE_VECTOR_ACCUM:
3790 case MODE_VECTOR_UACCUM:
3792 int i, units;
3793 enum machine_mode submode = GET_MODE_INNER (mode);
3794 unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode));
3796 gcc_assert (GET_CODE (x) == CONST_VECTOR);
3797 units = CONST_VECTOR_NUNITS (x);
3799 for (i = 0; i < units; i++)
3801 rtx elt = CONST_VECTOR_ELT (x, i);
3802 output_constant_pool_2 (submode, elt, i ? subalign : align);
3805 break;
3807 default:
3808 gcc_unreachable ();
3812 /* Worker function for output_constant_pool. Emit constant DESC,
3813 giving it ALIGN bits of alignment. */
3815 static void
3816 output_constant_pool_1 (struct constant_descriptor_rtx *desc,
3817 unsigned int align)
3819 rtx x, tmp;
3821 x = desc->constant;
3823 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3824 whose CODE_LABEL has been deleted. This can occur if a jump table
3825 is eliminated by optimization. If so, write a constant of zero
3826 instead. Note that this can also happen by turning the
3827 CODE_LABEL into a NOTE. */
3828 /* ??? This seems completely and utterly wrong. Certainly it's
3829 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper
3830 functioning even with INSN_DELETED_P and friends. */
3832 tmp = x;
3833 switch (GET_CODE (tmp))
3835 case CONST:
3836 if (GET_CODE (XEXP (tmp, 0)) != PLUS
3837 || GET_CODE (XEXP (XEXP (tmp, 0), 0)) != LABEL_REF)
3838 break;
3839 tmp = XEXP (XEXP (tmp, 0), 0);
3840 /* FALLTHRU */
3842 case LABEL_REF:
3843 tmp = XEXP (tmp, 0);
3844 gcc_assert (!INSN_DELETED_P (tmp));
3845 gcc_assert (!NOTE_P (tmp)
3846 || NOTE_KIND (tmp) != NOTE_INSN_DELETED);
3847 break;
3849 default:
3850 break;
3853 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3854 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode,
3855 align, desc->labelno, done);
3856 #endif
3858 assemble_align (align);
3860 /* Output the label. */
3861 targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno);
3863 /* Output the data. */
3864 output_constant_pool_2 (desc->mode, x, align);
3866 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS
3867 sections have proper size. */
3868 if (align > GET_MODE_BITSIZE (desc->mode)
3869 && in_section
3870 && (in_section->common.flags & SECTION_MERGE))
3871 assemble_align (align);
3873 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3874 done:
3875 #endif
3876 return;
3879 /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
3880 to as used. Emit referenced deferred strings. This function can
3881 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */
3883 static int
3884 mark_constant (rtx *current_rtx, void *data ATTRIBUTE_UNUSED)
3886 rtx x = *current_rtx;
3888 if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF)
3889 return 0;
3891 if (CONSTANT_POOL_ADDRESS_P (x))
3893 struct constant_descriptor_rtx *desc = SYMBOL_REF_CONSTANT (x);
3894 if (desc->mark == 0)
3896 desc->mark = 1;
3897 for_each_rtx (&desc->constant, mark_constant, NULL);
3900 else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
3902 tree decl = SYMBOL_REF_DECL (x);
3903 if (!TREE_ASM_WRITTEN (DECL_INITIAL (decl)))
3905 n_deferred_constants--;
3906 output_constant_def_contents (x);
3910 return -1;
3913 /* Look through appropriate parts of INSN, marking all entries in the
3914 constant pool which are actually being used. Entries that are only
3915 referenced by other constants are also marked as used. Emit
3916 deferred strings that are used. */
3918 static void
3919 mark_constants (rtx insn)
3921 if (!INSN_P (insn))
3922 return;
3924 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3925 insns, not any notes that may be attached. We don't want to mark
3926 a constant just because it happens to appear in a REG_EQUIV note. */
3927 if (GET_CODE (PATTERN (insn)) == SEQUENCE)
3929 rtx seq = PATTERN (insn);
3930 int i, n = XVECLEN (seq, 0);
3931 for (i = 0; i < n; ++i)
3933 rtx subinsn = XVECEXP (seq, 0, i);
3934 if (INSN_P (subinsn))
3935 for_each_rtx (&PATTERN (subinsn), mark_constant, NULL);
3938 else
3939 for_each_rtx (&PATTERN (insn), mark_constant, NULL);
3942 /* Look through the instructions for this function, and mark all the
3943 entries in POOL which are actually being used. Emit deferred constants
3944 which have indeed been used. */
3946 static void
3947 mark_constant_pool (void)
3949 rtx insn;
3951 if (!crtl->uses_const_pool && n_deferred_constants == 0)
3952 return;
3954 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3955 mark_constants (insn);
3958 /* Write all the constants in POOL. */
3960 static void
3961 output_constant_pool_contents (struct rtx_constant_pool *pool)
3963 struct constant_descriptor_rtx *desc;
3965 for (desc = pool->first; desc ; desc = desc->next)
3966 if (desc->mark)
3968 /* If the constant is part of an object_block, make sure that
3969 the constant has been positioned within its block, but do not
3970 write out its definition yet. output_object_blocks will do
3971 that later. */
3972 if (SYMBOL_REF_HAS_BLOCK_INFO_P (desc->sym)
3973 && SYMBOL_REF_BLOCK (desc->sym))
3974 place_block_symbol (desc->sym);
3975 else
3977 switch_to_section (targetm.asm_out.select_rtx_section
3978 (desc->mode, desc->constant, desc->align));
3979 output_constant_pool_1 (desc, desc->align);
3984 /* Mark all constants that are used in the current function, then write
3985 out the function's private constant pool. */
3987 static void
3988 output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
3989 tree fndecl ATTRIBUTE_UNUSED)
3991 struct rtx_constant_pool *pool = crtl->varasm.pool;
3993 /* It is possible for gcc to call force_const_mem and then to later
3994 discard the instructions which refer to the constant. In such a
3995 case we do not need to output the constant. */
3996 mark_constant_pool ();
3998 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3999 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset);
4000 #endif
4002 output_constant_pool_contents (pool);
4004 #ifdef ASM_OUTPUT_POOL_EPILOGUE
4005 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset);
4006 #endif
4009 /* Write the contents of the shared constant pool. */
4011 void
4012 output_shared_constant_pool (void)
4014 output_constant_pool_contents (shared_constant_pool);
4017 /* Determine what kind of relocations EXP may need. */
4020 compute_reloc_for_constant (tree exp)
4022 int reloc = 0, reloc2;
4023 tree tem;
4025 switch (TREE_CODE (exp))
4027 case ADDR_EXPR:
4028 case FDESC_EXPR:
4029 /* Go inside any operations that get_inner_reference can handle and see
4030 if what's inside is a constant: no need to do anything here for
4031 addresses of variables or functions. */
4032 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
4033 tem = TREE_OPERAND (tem, 0))
4036 if (TREE_CODE (tem) == MEM_REF
4037 && TREE_CODE (TREE_OPERAND (tem, 0)) == ADDR_EXPR)
4039 reloc = compute_reloc_for_constant (TREE_OPERAND (tem, 0));
4040 break;
4043 if (!targetm.binds_local_p (tem))
4044 reloc |= 2;
4045 else
4046 reloc |= 1;
4047 break;
4049 case PLUS_EXPR:
4050 case POINTER_PLUS_EXPR:
4051 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
4052 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1));
4053 break;
4055 case MINUS_EXPR:
4056 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
4057 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1));
4058 /* The difference of two local labels is computable at link time. */
4059 if (reloc == 1 && reloc2 == 1)
4060 reloc = 0;
4061 else
4062 reloc |= reloc2;
4063 break;
4065 CASE_CONVERT:
4066 case VIEW_CONVERT_EXPR:
4067 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
4068 break;
4070 case CONSTRUCTOR:
4072 unsigned HOST_WIDE_INT idx;
4073 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
4074 if (tem != 0)
4075 reloc |= compute_reloc_for_constant (tem);
4077 break;
4079 default:
4080 break;
4082 return reloc;
4085 /* Find all the constants whose addresses are referenced inside of EXP,
4086 and make sure assembler code with a label has been output for each one.
4087 Indicate whether an ADDR_EXPR has been encountered. */
4089 static void
4090 output_addressed_constants (tree exp)
4092 tree tem;
4094 switch (TREE_CODE (exp))
4096 case ADDR_EXPR:
4097 case FDESC_EXPR:
4098 /* Go inside any operations that get_inner_reference can handle and see
4099 if what's inside is a constant: no need to do anything here for
4100 addresses of variables or functions. */
4101 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
4102 tem = TREE_OPERAND (tem, 0))
4105 /* If we have an initialized CONST_DECL, retrieve the initializer. */
4106 if (TREE_CODE (tem) == CONST_DECL && DECL_INITIAL (tem))
4107 tem = DECL_INITIAL (tem);
4109 if (CONSTANT_CLASS_P (tem) || TREE_CODE (tem) == CONSTRUCTOR)
4110 output_constant_def (tem, 0);
4112 if (TREE_CODE (tem) == MEM_REF)
4113 output_addressed_constants (TREE_OPERAND (tem, 0));
4114 break;
4116 case PLUS_EXPR:
4117 case POINTER_PLUS_EXPR:
4118 case MINUS_EXPR:
4119 output_addressed_constants (TREE_OPERAND (exp, 1));
4120 /* Fall through. */
4122 CASE_CONVERT:
4123 case VIEW_CONVERT_EXPR:
4124 output_addressed_constants (TREE_OPERAND (exp, 0));
4125 break;
4127 case CONSTRUCTOR:
4129 unsigned HOST_WIDE_INT idx;
4130 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
4131 if (tem != 0)
4132 output_addressed_constants (tem);
4134 break;
4136 default:
4137 break;
4141 /* Whether a constructor CTOR is a valid static constant initializer if all
4142 its elements are. This used to be internal to initializer_constant_valid_p
4143 and has been exposed to let other functions like categorize_ctor_elements
4144 evaluate the property while walking a constructor for other purposes. */
4146 bool
4147 constructor_static_from_elts_p (const_tree ctor)
4149 return (TREE_CONSTANT (ctor)
4150 && (TREE_CODE (TREE_TYPE (ctor)) == UNION_TYPE
4151 || TREE_CODE (TREE_TYPE (ctor)) == RECORD_TYPE
4152 || TREE_CODE (TREE_TYPE (ctor)) == ARRAY_TYPE));
4155 static tree initializer_constant_valid_p_1 (tree value, tree endtype,
4156 tree *cache);
4158 /* A subroutine of initializer_constant_valid_p. VALUE is a MINUS_EXPR,
4159 PLUS_EXPR or POINTER_PLUS_EXPR. This looks for cases of VALUE
4160 which are valid when ENDTYPE is an integer of any size; in
4161 particular, this does not accept a pointer minus a constant. This
4162 returns null_pointer_node if the VALUE is an absolute constant
4163 which can be used to initialize a static variable. Otherwise it
4164 returns NULL. */
4166 static tree
4167 narrowing_initializer_constant_valid_p (tree value, tree endtype, tree *cache)
4169 tree op0, op1;
4171 if (!INTEGRAL_TYPE_P (endtype))
4172 return NULL_TREE;
4174 op0 = TREE_OPERAND (value, 0);
4175 op1 = TREE_OPERAND (value, 1);
4177 /* Like STRIP_NOPS except allow the operand mode to widen. This
4178 works around a feature of fold that simplifies (int)(p1 - p2) to
4179 ((int)p1 - (int)p2) under the theory that the narrower operation
4180 is cheaper. */
4182 while (CONVERT_EXPR_P (op0)
4183 || TREE_CODE (op0) == NON_LVALUE_EXPR)
4185 tree inner = TREE_OPERAND (op0, 0);
4186 if (inner == error_mark_node
4187 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4188 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))
4189 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4190 break;
4191 op0 = inner;
4194 while (CONVERT_EXPR_P (op1)
4195 || TREE_CODE (op1) == NON_LVALUE_EXPR)
4197 tree inner = TREE_OPERAND (op1, 0);
4198 if (inner == error_mark_node
4199 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4200 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))
4201 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4202 break;
4203 op1 = inner;
4206 op0 = initializer_constant_valid_p_1 (op0, endtype, cache);
4207 if (!op0)
4208 return NULL_TREE;
4210 op1 = initializer_constant_valid_p_1 (op1, endtype,
4211 cache ? cache + 2 : NULL);
4212 /* Both initializers must be known. */
4213 if (op1)
4215 if (op0 == op1
4216 && (op0 == null_pointer_node
4217 || TREE_CODE (value) == MINUS_EXPR))
4218 return null_pointer_node;
4220 /* Support differences between labels. */
4221 if (TREE_CODE (op0) == LABEL_DECL
4222 && TREE_CODE (op1) == LABEL_DECL)
4223 return null_pointer_node;
4225 if (TREE_CODE (op0) == STRING_CST
4226 && TREE_CODE (op1) == STRING_CST
4227 && operand_equal_p (op0, op1, 1))
4228 return null_pointer_node;
4231 return NULL_TREE;
4234 /* Helper function of initializer_constant_valid_p.
4235 Return nonzero if VALUE is a valid constant-valued expression
4236 for use in initializing a static variable; one that can be an
4237 element of a "constant" initializer.
4239 Return null_pointer_node if the value is absolute;
4240 if it is relocatable, return the variable that determines the relocation.
4241 We assume that VALUE has been folded as much as possible;
4242 therefore, we do not need to check for such things as
4243 arithmetic-combinations of integers.
4245 Use CACHE (pointer to 2 tree values) for caching if non-NULL. */
4247 static tree
4248 initializer_constant_valid_p_1 (tree value, tree endtype, tree *cache)
4250 tree ret;
4252 switch (TREE_CODE (value))
4254 case CONSTRUCTOR:
4255 if (constructor_static_from_elts_p (value))
4257 unsigned HOST_WIDE_INT idx;
4258 tree elt;
4259 bool absolute = true;
4261 if (cache && cache[0] == value)
4262 return cache[1];
4263 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
4265 tree reloc;
4266 reloc = initializer_constant_valid_p_1 (elt, TREE_TYPE (elt),
4267 NULL);
4268 if (!reloc)
4270 if (cache)
4272 cache[0] = value;
4273 cache[1] = NULL_TREE;
4275 return NULL_TREE;
4277 if (reloc != null_pointer_node)
4278 absolute = false;
4280 /* For a non-absolute relocation, there is no single
4281 variable that can be "the variable that determines the
4282 relocation." */
4283 if (cache)
4285 cache[0] = value;
4286 cache[1] = absolute ? null_pointer_node : error_mark_node;
4288 return absolute ? null_pointer_node : error_mark_node;
4291 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE;
4293 case INTEGER_CST:
4294 case VECTOR_CST:
4295 case REAL_CST:
4296 case FIXED_CST:
4297 case STRING_CST:
4298 case COMPLEX_CST:
4299 return null_pointer_node;
4301 case ADDR_EXPR:
4302 case FDESC_EXPR:
4304 tree op0 = staticp (TREE_OPERAND (value, 0));
4305 if (op0)
4307 /* "&(*a).f" is like unto pointer arithmetic. If "a" turns out
4308 to be a constant, this is old-skool offsetof-like nonsense. */
4309 if (TREE_CODE (op0) == INDIRECT_REF
4310 && TREE_CONSTANT (TREE_OPERAND (op0, 0)))
4311 return null_pointer_node;
4312 /* Taking the address of a nested function involves a trampoline,
4313 unless we don't need or want one. */
4314 if (TREE_CODE (op0) == FUNCTION_DECL
4315 && DECL_STATIC_CHAIN (op0)
4316 && !TREE_NO_TRAMPOLINE (value))
4317 return NULL_TREE;
4318 /* "&{...}" requires a temporary to hold the constructed
4319 object. */
4320 if (TREE_CODE (op0) == CONSTRUCTOR)
4321 return NULL_TREE;
4323 return op0;
4326 case NON_LVALUE_EXPR:
4327 return initializer_constant_valid_p_1 (TREE_OPERAND (value, 0),
4328 endtype, cache);
4330 case VIEW_CONVERT_EXPR:
4332 tree src = TREE_OPERAND (value, 0);
4333 tree src_type = TREE_TYPE (src);
4334 tree dest_type = TREE_TYPE (value);
4336 /* Allow view-conversions from aggregate to non-aggregate type only
4337 if the bit pattern is fully preserved afterwards; otherwise, the
4338 RTL expander won't be able to apply a subsequent transformation
4339 to the underlying constructor. */
4340 if (AGGREGATE_TYPE_P (src_type) && !AGGREGATE_TYPE_P (dest_type))
4342 if (TYPE_MODE (endtype) == TYPE_MODE (dest_type))
4343 return initializer_constant_valid_p_1 (src, endtype, cache);
4344 else
4345 return NULL_TREE;
4348 /* Allow all other kinds of view-conversion. */
4349 return initializer_constant_valid_p_1 (src, endtype, cache);
4352 CASE_CONVERT:
4354 tree src = TREE_OPERAND (value, 0);
4355 tree src_type = TREE_TYPE (src);
4356 tree dest_type = TREE_TYPE (value);
4358 /* Allow conversions between pointer types, floating-point
4359 types, and offset types. */
4360 if ((POINTER_TYPE_P (dest_type) && POINTER_TYPE_P (src_type))
4361 || (FLOAT_TYPE_P (dest_type) && FLOAT_TYPE_P (src_type))
4362 || (TREE_CODE (dest_type) == OFFSET_TYPE
4363 && TREE_CODE (src_type) == OFFSET_TYPE))
4364 return initializer_constant_valid_p_1 (src, endtype, cache);
4366 /* Allow length-preserving conversions between integer types. */
4367 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type)
4368 && (TYPE_PRECISION (dest_type) == TYPE_PRECISION (src_type)))
4369 return initializer_constant_valid_p_1 (src, endtype, cache);
4371 /* Allow conversions between other integer types only if
4372 explicit value. */
4373 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type))
4375 tree inner = initializer_constant_valid_p_1 (src, endtype, cache);
4376 if (inner == null_pointer_node)
4377 return null_pointer_node;
4378 break;
4381 /* Allow (int) &foo provided int is as wide as a pointer. */
4382 if (INTEGRAL_TYPE_P (dest_type) && POINTER_TYPE_P (src_type)
4383 && (TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type)))
4384 return initializer_constant_valid_p_1 (src, endtype, cache);
4386 /* Likewise conversions from int to pointers, but also allow
4387 conversions from 0. */
4388 if ((POINTER_TYPE_P (dest_type)
4389 || TREE_CODE (dest_type) == OFFSET_TYPE)
4390 && INTEGRAL_TYPE_P (src_type))
4392 if (TREE_CODE (src) == INTEGER_CST
4393 && TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type))
4394 return null_pointer_node;
4395 if (integer_zerop (src))
4396 return null_pointer_node;
4397 else if (TYPE_PRECISION (dest_type) <= TYPE_PRECISION (src_type))
4398 return initializer_constant_valid_p_1 (src, endtype, cache);
4401 /* Allow conversions to struct or union types if the value
4402 inside is okay. */
4403 if (TREE_CODE (dest_type) == RECORD_TYPE
4404 || TREE_CODE (dest_type) == UNION_TYPE)
4405 return initializer_constant_valid_p_1 (src, endtype, cache);
4407 break;
4409 case POINTER_PLUS_EXPR:
4410 case PLUS_EXPR:
4411 /* Any valid floating-point constants will have been folded by now;
4412 with -frounding-math we hit this with addition of two constants. */
4413 if (TREE_CODE (endtype) == REAL_TYPE)
4414 return NULL_TREE;
4415 if (cache && cache[0] == value)
4416 return cache[1];
4417 if (! INTEGRAL_TYPE_P (endtype)
4418 || TYPE_PRECISION (endtype) >= TYPE_PRECISION (TREE_TYPE (value)))
4420 tree ncache[4] = { NULL_TREE, NULL_TREE, NULL_TREE, NULL_TREE };
4421 tree valid0
4422 = initializer_constant_valid_p_1 (TREE_OPERAND (value, 0),
4423 endtype, ncache);
4424 tree valid1
4425 = initializer_constant_valid_p_1 (TREE_OPERAND (value, 1),
4426 endtype, ncache + 2);
4427 /* If either term is absolute, use the other term's relocation. */
4428 if (valid0 == null_pointer_node)
4429 ret = valid1;
4430 else if (valid1 == null_pointer_node)
4431 ret = valid0;
4432 /* Support narrowing pointer differences. */
4433 else
4434 ret = narrowing_initializer_constant_valid_p (value, endtype,
4435 ncache);
4437 else
4438 /* Support narrowing pointer differences. */
4439 ret = narrowing_initializer_constant_valid_p (value, endtype, NULL);
4440 if (cache)
4442 cache[0] = value;
4443 cache[1] = ret;
4445 return ret;
4447 case MINUS_EXPR:
4448 if (TREE_CODE (endtype) == REAL_TYPE)
4449 return NULL_TREE;
4450 if (cache && cache[0] == value)
4451 return cache[1];
4452 if (! INTEGRAL_TYPE_P (endtype)
4453 || TYPE_PRECISION (endtype) >= TYPE_PRECISION (TREE_TYPE (value)))
4455 tree ncache[4] = { NULL_TREE, NULL_TREE, NULL_TREE, NULL_TREE };
4456 tree valid0
4457 = initializer_constant_valid_p_1 (TREE_OPERAND (value, 0),
4458 endtype, ncache);
4459 tree valid1
4460 = initializer_constant_valid_p_1 (TREE_OPERAND (value, 1),
4461 endtype, ncache + 2);
4462 /* Win if second argument is absolute. */
4463 if (valid1 == null_pointer_node)
4464 ret = valid0;
4465 /* Win if both arguments have the same relocation.
4466 Then the value is absolute. */
4467 else if (valid0 == valid1 && valid0 != 0)
4468 ret = null_pointer_node;
4469 /* Since GCC guarantees that string constants are unique in the
4470 generated code, a subtraction between two copies of the same
4471 constant string is absolute. */
4472 else if (valid0 && TREE_CODE (valid0) == STRING_CST
4473 && valid1 && TREE_CODE (valid1) == STRING_CST
4474 && operand_equal_p (valid0, valid1, 1))
4475 ret = null_pointer_node;
4476 /* Support narrowing differences. */
4477 else
4478 ret = narrowing_initializer_constant_valid_p (value, endtype,
4479 ncache);
4481 else
4482 /* Support narrowing differences. */
4483 ret = narrowing_initializer_constant_valid_p (value, endtype, NULL);
4484 if (cache)
4486 cache[0] = value;
4487 cache[1] = ret;
4489 return ret;
4491 default:
4492 break;
4495 return NULL_TREE;
4498 /* Return nonzero if VALUE is a valid constant-valued expression
4499 for use in initializing a static variable; one that can be an
4500 element of a "constant" initializer.
4502 Return null_pointer_node if the value is absolute;
4503 if it is relocatable, return the variable that determines the relocation.
4504 We assume that VALUE has been folded as much as possible;
4505 therefore, we do not need to check for such things as
4506 arithmetic-combinations of integers. */
4507 tree
4508 initializer_constant_valid_p (tree value, tree endtype)
4510 return initializer_constant_valid_p_1 (value, endtype, NULL);
4513 /* Return true if VALUE is a valid constant-valued expression
4514 for use in initializing a static bit-field; one that can be
4515 an element of a "constant" initializer. */
4517 bool
4518 initializer_constant_valid_for_bitfield_p (tree value)
4520 /* For bitfields we support integer constants or possibly nested aggregates
4521 of such. */
4522 switch (TREE_CODE (value))
4524 case CONSTRUCTOR:
4526 unsigned HOST_WIDE_INT idx;
4527 tree elt;
4529 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
4530 if (!initializer_constant_valid_for_bitfield_p (elt))
4531 return false;
4532 return true;
4535 case INTEGER_CST:
4536 case REAL_CST:
4537 return true;
4539 case VIEW_CONVERT_EXPR:
4540 case NON_LVALUE_EXPR:
4541 return
4542 initializer_constant_valid_for_bitfield_p (TREE_OPERAND (value, 0));
4544 default:
4545 break;
4548 return false;
4551 /* output_constructor outer state of relevance in recursive calls, typically
4552 for nested aggregate bitfields. */
4554 typedef struct {
4555 unsigned int bit_offset; /* current position in ... */
4556 int byte; /* ... the outer byte buffer. */
4557 } oc_outer_state;
4559 static unsigned HOST_WIDE_INT
4560 output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int,
4561 oc_outer_state *);
4563 /* Output assembler code for constant EXP, with no label.
4564 This includes the pseudo-op such as ".int" or ".byte", and a newline.
4565 Assumes output_addressed_constants has been done on EXP already.
4567 Generate at least SIZE bytes of assembler data, padding at the end
4568 with zeros if necessary. SIZE must always be specified. The returned
4569 value is the actual number of bytes of assembler data generated, which
4570 may be bigger than SIZE if the object contains a variable length field.
4572 SIZE is important for structure constructors,
4573 since trailing members may have been omitted from the constructor.
4574 It is also important for initialization of arrays from string constants
4575 since the full length of the string constant might not be wanted.
4576 It is also needed for initialization of unions, where the initializer's
4577 type is just one member, and that may not be as long as the union.
4579 There a case in which we would fail to output exactly SIZE bytes:
4580 for a structure constructor that wants to produce more than SIZE bytes.
4581 But such constructors will never be generated for any possible input.
4583 ALIGN is the alignment of the data in bits. */
4585 static unsigned HOST_WIDE_INT
4586 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
4588 enum tree_code code;
4589 unsigned HOST_WIDE_INT thissize;
4591 if (size == 0 || flag_syntax_only)
4592 return size;
4594 /* See if we're trying to initialize a pointer in a non-default mode
4595 to the address of some declaration somewhere. If the target says
4596 the mode is valid for pointers, assume the target has a way of
4597 resolving it. */
4598 if (TREE_CODE (exp) == NOP_EXPR
4599 && POINTER_TYPE_P (TREE_TYPE (exp))
4600 && targetm.addr_space.valid_pointer_mode
4601 (TYPE_MODE (TREE_TYPE (exp)),
4602 TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (exp)))))
4604 tree saved_type = TREE_TYPE (exp);
4606 /* Peel off any intermediate conversions-to-pointer for valid
4607 pointer modes. */
4608 while (TREE_CODE (exp) == NOP_EXPR
4609 && POINTER_TYPE_P (TREE_TYPE (exp))
4610 && targetm.addr_space.valid_pointer_mode
4611 (TYPE_MODE (TREE_TYPE (exp)),
4612 TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (exp)))))
4613 exp = TREE_OPERAND (exp, 0);
4615 /* If what we're left with is the address of something, we can
4616 convert the address to the final type and output it that
4617 way. */
4618 if (TREE_CODE (exp) == ADDR_EXPR)
4619 exp = build1 (ADDR_EXPR, saved_type, TREE_OPERAND (exp, 0));
4620 /* Likewise for constant ints. */
4621 else if (TREE_CODE (exp) == INTEGER_CST)
4622 exp = wide_int_to_tree (saved_type, exp);
4626 /* Eliminate any conversions since we'll be outputting the underlying
4627 constant. */
4628 while (CONVERT_EXPR_P (exp)
4629 || TREE_CODE (exp) == NON_LVALUE_EXPR
4630 || TREE_CODE (exp) == VIEW_CONVERT_EXPR)
4632 HOST_WIDE_INT type_size = int_size_in_bytes (TREE_TYPE (exp));
4633 HOST_WIDE_INT op_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (exp, 0)));
4635 /* Make sure eliminating the conversion is really a no-op, except with
4636 VIEW_CONVERT_EXPRs to allow for wild Ada unchecked conversions and
4637 union types to allow for Ada unchecked unions. */
4638 if (type_size > op_size
4639 && TREE_CODE (exp) != VIEW_CONVERT_EXPR
4640 && TREE_CODE (TREE_TYPE (exp)) != UNION_TYPE)
4641 /* Keep the conversion. */
4642 break;
4643 else
4644 exp = TREE_OPERAND (exp, 0);
4647 code = TREE_CODE (TREE_TYPE (exp));
4648 thissize = int_size_in_bytes (TREE_TYPE (exp));
4650 /* Allow a constructor with no elements for any data type.
4651 This means to fill the space with zeros. */
4652 if (TREE_CODE (exp) == CONSTRUCTOR
4653 && vec_safe_is_empty (CONSTRUCTOR_ELTS (exp)))
4655 assemble_zeros (size);
4656 return size;
4659 if (TREE_CODE (exp) == FDESC_EXPR)
4661 #ifdef ASM_OUTPUT_FDESC
4662 HOST_WIDE_INT part = tree_to_shwi (TREE_OPERAND (exp, 1));
4663 tree decl = TREE_OPERAND (exp, 0);
4664 ASM_OUTPUT_FDESC (asm_out_file, decl, part);
4665 #else
4666 gcc_unreachable ();
4667 #endif
4668 return size;
4671 /* Now output the underlying data. If we've handling the padding, return.
4672 Otherwise, break and ensure SIZE is the size written. */
4673 switch (code)
4675 case BOOLEAN_TYPE:
4676 case INTEGER_TYPE:
4677 case ENUMERAL_TYPE:
4678 case POINTER_TYPE:
4679 case REFERENCE_TYPE:
4680 case OFFSET_TYPE:
4681 case FIXED_POINT_TYPE:
4682 case NULLPTR_TYPE:
4683 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
4684 EXPAND_INITIALIZER),
4685 MIN (size, thissize), align, 0))
4686 error ("initializer for integer/fixed-point value is too complicated");
4687 break;
4689 case REAL_TYPE:
4690 if (TREE_CODE (exp) != REAL_CST)
4691 error ("initializer for floating value is not a floating constant");
4692 else
4693 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
4694 break;
4696 case COMPLEX_TYPE:
4697 output_constant (TREE_REALPART (exp), thissize / 2, align);
4698 output_constant (TREE_IMAGPART (exp), thissize / 2,
4699 min_align (align, BITS_PER_UNIT * (thissize / 2)));
4700 break;
4702 case ARRAY_TYPE:
4703 case VECTOR_TYPE:
4704 switch (TREE_CODE (exp))
4706 case CONSTRUCTOR:
4707 return output_constructor (exp, size, align, NULL);
4708 case STRING_CST:
4709 thissize
4710 = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp), size);
4711 assemble_string (TREE_STRING_POINTER (exp), thissize);
4712 break;
4713 case VECTOR_CST:
4715 enum machine_mode inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp)));
4716 unsigned int nalign = MIN (align, GET_MODE_ALIGNMENT (inner));
4717 int elt_size = GET_MODE_SIZE (inner);
4718 output_constant (VECTOR_CST_ELT (exp, 0), elt_size, align);
4719 thissize = elt_size;
4720 for (unsigned int i = 1; i < VECTOR_CST_NELTS (exp); i++)
4722 output_constant (VECTOR_CST_ELT (exp, i), elt_size, nalign);
4723 thissize += elt_size;
4725 break;
4727 default:
4728 gcc_unreachable ();
4730 break;
4732 case RECORD_TYPE:
4733 case UNION_TYPE:
4734 gcc_assert (TREE_CODE (exp) == CONSTRUCTOR);
4735 return output_constructor (exp, size, align, NULL);
4737 case ERROR_MARK:
4738 return 0;
4740 default:
4741 gcc_unreachable ();
4744 if (size > thissize)
4745 assemble_zeros (size - thissize);
4747 return size;
4751 /* Subroutine of output_constructor, used for computing the size of
4752 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array
4753 type with an unspecified upper bound. */
4755 static unsigned HOST_WIDE_INT
4756 array_size_for_constructor (tree val)
4758 tree max_index;
4759 unsigned HOST_WIDE_INT cnt;
4760 tree index, value, tmp;
4761 offset_int i;
4763 /* This code used to attempt to handle string constants that are not
4764 arrays of single-bytes, but nothing else does, so there's no point in
4765 doing it here. */
4766 if (TREE_CODE (val) == STRING_CST)
4767 return TREE_STRING_LENGTH (val);
4769 max_index = NULL_TREE;
4770 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (val), cnt, index, value)
4772 if (TREE_CODE (index) == RANGE_EXPR)
4773 index = TREE_OPERAND (index, 1);
4774 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index))
4775 max_index = index;
4778 if (max_index == NULL_TREE)
4779 return 0;
4781 /* Compute the total number of array elements. */
4782 tmp = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val)));
4783 i = wi::to_offset (max_index) - wi::to_offset (tmp) + 1;
4785 /* Multiply by the array element unit size to find number of bytes. */
4786 i *= wi::to_offset (TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val))));
4788 gcc_assert (wi::fits_uhwi_p (i));
4789 return i.to_uhwi ();
4792 /* Other datastructures + helpers for output_constructor. */
4794 /* output_constructor local state to support interaction with helpers. */
4796 typedef struct {
4798 /* Received arguments. */
4799 tree exp; /* Constructor expression. */
4800 tree type; /* Type of constructor expression. */
4801 unsigned HOST_WIDE_INT size; /* # bytes to output - pad if necessary. */
4802 unsigned int align; /* Known initial alignment. */
4803 tree min_index; /* Lower bound if specified for an array. */
4805 /* Output processing state. */
4806 HOST_WIDE_INT total_bytes; /* # bytes output so far / current position. */
4807 int byte; /* Part of a bitfield byte yet to be output. */
4808 int last_relative_index; /* Implicit or explicit index of the last
4809 array element output within a bitfield. */
4810 bool byte_buffer_in_use; /* Whether BYTE is in use. */
4812 /* Current element. */
4813 tree field; /* Current field decl in a record. */
4814 tree val; /* Current element value. */
4815 tree index; /* Current element index. */
4817 } oc_local_state;
4819 /* Helper for output_constructor. From the current LOCAL state, output a
4820 RANGE_EXPR element. */
4822 static void
4823 output_constructor_array_range (oc_local_state *local)
4825 unsigned HOST_WIDE_INT fieldsize
4826 = int_size_in_bytes (TREE_TYPE (local->type));
4828 HOST_WIDE_INT lo_index
4829 = tree_to_shwi (TREE_OPERAND (local->index, 0));
4830 HOST_WIDE_INT hi_index
4831 = tree_to_shwi (TREE_OPERAND (local->index, 1));
4832 HOST_WIDE_INT index;
4834 unsigned int align2
4835 = min_align (local->align, fieldsize * BITS_PER_UNIT);
4837 for (index = lo_index; index <= hi_index; index++)
4839 /* Output the element's initial value. */
4840 if (local->val == NULL_TREE)
4841 assemble_zeros (fieldsize);
4842 else
4843 fieldsize = output_constant (local->val, fieldsize, align2);
4845 /* Count its size. */
4846 local->total_bytes += fieldsize;
4850 /* Helper for output_constructor. From the current LOCAL state, output a
4851 field element that is not true bitfield or part of an outer one. */
4853 static void
4854 output_constructor_regular_field (oc_local_state *local)
4856 /* Field size and position. Since this structure is static, we know the
4857 positions are constant. */
4858 unsigned HOST_WIDE_INT fieldsize;
4859 HOST_WIDE_INT fieldpos;
4861 unsigned int align2;
4863 if (local->index != NULL_TREE)
4865 /* Perform the index calculation in modulo arithmetic but
4866 sign-extend the result because Ada has negative DECL_FIELD_OFFSETs
4867 but we are using an unsigned sizetype. */
4868 unsigned prec = TYPE_PRECISION (sizetype);
4869 offset_int idx = wi::sext (wi::to_offset (local->index)
4870 - wi::to_offset (local->min_index), prec);
4871 fieldpos = (idx * wi::to_offset (TYPE_SIZE_UNIT (TREE_TYPE (local->val))))
4872 .to_short_addr ();
4874 else if (local->field != NULL_TREE)
4875 fieldpos = int_byte_position (local->field);
4876 else
4877 fieldpos = 0;
4879 /* Output any buffered-up bit-fields preceding this element. */
4880 if (local->byte_buffer_in_use)
4882 assemble_integer (GEN_INT (local->byte), 1, BITS_PER_UNIT, 1);
4883 local->total_bytes++;
4884 local->byte_buffer_in_use = false;
4887 /* Advance to offset of this element.
4888 Note no alignment needed in an array, since that is guaranteed
4889 if each element has the proper size. */
4890 if ((local->field != NULL_TREE || local->index != NULL_TREE)
4891 && fieldpos > local->total_bytes)
4893 assemble_zeros (fieldpos - local->total_bytes);
4894 local->total_bytes = fieldpos;
4897 /* Find the alignment of this element. */
4898 align2 = min_align (local->align, BITS_PER_UNIT * fieldpos);
4900 /* Determine size this element should occupy. */
4901 if (local->field)
4903 fieldsize = 0;
4905 /* If this is an array with an unspecified upper bound,
4906 the initializer determines the size. */
4907 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL,
4908 but we cannot do this until the deprecated support for
4909 initializing zero-length array members is removed. */
4910 if (TREE_CODE (TREE_TYPE (local->field)) == ARRAY_TYPE
4911 && TYPE_DOMAIN (TREE_TYPE (local->field))
4912 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (local->field))))
4914 fieldsize = array_size_for_constructor (local->val);
4915 /* Given a non-empty initialization, this field had
4916 better be last. */
4917 gcc_assert (!fieldsize || !DECL_CHAIN (local->field));
4919 else
4920 fieldsize = tree_to_uhwi (DECL_SIZE_UNIT (local->field));
4922 else
4923 fieldsize = int_size_in_bytes (TREE_TYPE (local->type));
4925 /* Output the element's initial value. */
4926 if (local->val == NULL_TREE)
4927 assemble_zeros (fieldsize);
4928 else
4929 fieldsize = output_constant (local->val, fieldsize, align2);
4931 /* Count its size. */
4932 local->total_bytes += fieldsize;
4935 /* Helper for output_constructor. From the LOCAL state, output an element
4936 that is a true bitfield or part of an outer one. BIT_OFFSET is the offset
4937 from the start of a possibly ongoing outer byte buffer. */
4939 static void
4940 output_constructor_bitfield (oc_local_state *local, unsigned int bit_offset)
4942 /* Bit size of this element. */
4943 HOST_WIDE_INT ebitsize
4944 = (local->field
4945 ? tree_to_uhwi (DECL_SIZE (local->field))
4946 : tree_to_uhwi (TYPE_SIZE (TREE_TYPE (local->type))));
4948 /* Relative index of this element if this is an array component. */
4949 HOST_WIDE_INT relative_index
4950 = (!local->field
4951 ? (local->index
4952 ? (tree_to_shwi (local->index)
4953 - tree_to_shwi (local->min_index))
4954 : local->last_relative_index + 1)
4955 : 0);
4957 /* Bit position of this element from the start of the containing
4958 constructor. */
4959 HOST_WIDE_INT constructor_relative_ebitpos
4960 = (local->field
4961 ? int_bit_position (local->field)
4962 : ebitsize * relative_index);
4964 /* Bit position of this element from the start of a possibly ongoing
4965 outer byte buffer. */
4966 HOST_WIDE_INT byte_relative_ebitpos
4967 = bit_offset + constructor_relative_ebitpos;
4969 /* From the start of a possibly ongoing outer byte buffer, offsets to
4970 the first bit of this element and to the first bit past the end of
4971 this element. */
4972 HOST_WIDE_INT next_offset = byte_relative_ebitpos;
4973 HOST_WIDE_INT end_offset = byte_relative_ebitpos + ebitsize;
4975 local->last_relative_index = relative_index;
4977 if (local->val == NULL_TREE)
4978 local->val = integer_zero_node;
4980 while (TREE_CODE (local->val) == VIEW_CONVERT_EXPR
4981 || TREE_CODE (local->val) == NON_LVALUE_EXPR)
4982 local->val = TREE_OPERAND (local->val, 0);
4984 if (TREE_CODE (local->val) != INTEGER_CST
4985 && TREE_CODE (local->val) != CONSTRUCTOR)
4987 error ("invalid initial value for member %qE", DECL_NAME (local->field));
4988 return;
4991 /* If this field does not start in this (or next) byte, skip some bytes. */
4992 if (next_offset / BITS_PER_UNIT != local->total_bytes)
4994 /* Output remnant of any bit field in previous bytes. */
4995 if (local->byte_buffer_in_use)
4997 assemble_integer (GEN_INT (local->byte), 1, BITS_PER_UNIT, 1);
4998 local->total_bytes++;
4999 local->byte_buffer_in_use = false;
5002 /* If still not at proper byte, advance to there. */
5003 if (next_offset / BITS_PER_UNIT != local->total_bytes)
5005 gcc_assert (next_offset / BITS_PER_UNIT >= local->total_bytes);
5006 assemble_zeros (next_offset / BITS_PER_UNIT - local->total_bytes);
5007 local->total_bytes = next_offset / BITS_PER_UNIT;
5011 /* Set up the buffer if necessary. */
5012 if (!local->byte_buffer_in_use)
5014 local->byte = 0;
5015 if (ebitsize > 0)
5016 local->byte_buffer_in_use = true;
5019 /* If this is nested constructor, recurse passing the bit offset and the
5020 pending data, then retrieve the new pending data afterwards. */
5021 if (TREE_CODE (local->val) == CONSTRUCTOR)
5023 oc_outer_state temp_state;
5024 temp_state.bit_offset = next_offset % BITS_PER_UNIT;
5025 temp_state.byte = local->byte;
5026 local->total_bytes
5027 += output_constructor (local->val, 0, 0, &temp_state);
5028 local->byte = temp_state.byte;
5029 return;
5032 /* Otherwise, we must split the element into pieces that fall within
5033 separate bytes, and combine each byte with previous or following
5034 bit-fields. */
5035 while (next_offset < end_offset)
5037 int this_time;
5038 int shift;
5039 HOST_WIDE_INT value;
5040 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
5041 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
5043 /* Advance from byte to byte within this element when necessary. */
5044 while (next_byte != local->total_bytes)
5046 assemble_integer (GEN_INT (local->byte), 1, BITS_PER_UNIT, 1);
5047 local->total_bytes++;
5048 local->byte = 0;
5051 /* Number of bits we can process at once (all part of the same byte). */
5052 this_time = MIN (end_offset - next_offset, BITS_PER_UNIT - next_bit);
5053 if (BYTES_BIG_ENDIAN)
5055 /* On big-endian machine, take the most significant bits (of the
5056 bits that are significant) first and put them into bytes from
5057 the most significant end. */
5058 shift = end_offset - next_offset - this_time;
5060 /* Don't try to take a bunch of bits that cross
5061 the word boundary in the INTEGER_CST. We can
5062 only select bits from one element. */
5063 if ((shift / HOST_BITS_PER_WIDE_INT)
5064 != ((shift + this_time - 1) / HOST_BITS_PER_WIDE_INT))
5066 const int end = shift + this_time - 1;
5067 shift = end & -HOST_BITS_PER_WIDE_INT;
5068 this_time = end - shift + 1;
5071 /* Now get the bits from the appropriate constant word. */
5072 value = TREE_INT_CST_ELT (local->val, shift / HOST_BITS_PER_WIDE_INT);
5073 shift = shift & (HOST_BITS_PER_WIDE_INT - 1);
5075 /* Get the result. This works only when:
5076 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
5077 local->byte |= (((value >> shift)
5078 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
5079 << (BITS_PER_UNIT - this_time - next_bit));
5081 else
5083 /* On little-endian machines, take the least significant bits of
5084 the value first and pack them starting at the least significant
5085 bits of the bytes. */
5086 shift = next_offset - byte_relative_ebitpos;
5088 /* Don't try to take a bunch of bits that cross
5089 the word boundary in the INTEGER_CST. We can
5090 only select bits from one element. */
5091 if ((shift / HOST_BITS_PER_WIDE_INT)
5092 != ((shift + this_time - 1) / HOST_BITS_PER_WIDE_INT))
5093 this_time
5094 = HOST_BITS_PER_WIDE_INT - (shift & (HOST_BITS_PER_WIDE_INT - 1));
5096 /* Now get the bits from the appropriate constant word. */
5097 value = TREE_INT_CST_ELT (local->val, shift / HOST_BITS_PER_WIDE_INT);
5098 shift = shift & (HOST_BITS_PER_WIDE_INT - 1);
5100 /* Get the result. This works only when:
5101 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
5102 local->byte |= (((value >> shift)
5103 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
5104 << next_bit);
5107 next_offset += this_time;
5108 local->byte_buffer_in_use = true;
5112 /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants).
5113 Generate at least SIZE bytes, padding if necessary. OUTER designates the
5114 caller output state of relevance in recursive invocations. */
5116 static unsigned HOST_WIDE_INT
5117 output_constructor (tree exp, unsigned HOST_WIDE_INT size,
5118 unsigned int align, oc_outer_state *outer)
5120 unsigned HOST_WIDE_INT cnt;
5121 constructor_elt *ce;
5123 oc_local_state local;
5125 /* Setup our local state to communicate with helpers. */
5126 local.exp = exp;
5127 local.type = TREE_TYPE (exp);
5128 local.size = size;
5129 local.align = align;
5130 if (TREE_CODE (local.type) == ARRAY_TYPE && TYPE_DOMAIN (local.type))
5131 local.min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (local.type));
5132 else
5133 local.min_index = NULL_TREE;
5135 local.total_bytes = 0;
5136 local.byte_buffer_in_use = outer != NULL;
5137 local.byte = outer ? outer->byte : 0;
5138 local.last_relative_index = -1;
5140 gcc_assert (HOST_BITS_PER_WIDE_INT >= BITS_PER_UNIT);
5142 /* As CE goes through the elements of the constant, FIELD goes through the
5143 structure fields if the constant is a structure. If the constant is a
5144 union, we override this by getting the field from the TREE_LIST element.
5145 But the constant could also be an array. Then FIELD is zero.
5147 There is always a maximum of one element in the chain LINK for unions
5148 (even if the initializer in a source program incorrectly contains
5149 more one). */
5151 if (TREE_CODE (local.type) == RECORD_TYPE)
5152 local.field = TYPE_FIELDS (local.type);
5153 else
5154 local.field = NULL_TREE;
5156 for (cnt = 0;
5157 vec_safe_iterate (CONSTRUCTOR_ELTS (exp), cnt, &ce);
5158 cnt++, local.field = local.field ? DECL_CHAIN (local.field) : 0)
5160 local.val = ce->value;
5161 local.index = NULL_TREE;
5163 /* The element in a union constructor specifies the proper field
5164 or index. */
5165 if (RECORD_OR_UNION_TYPE_P (local.type) && ce->index != NULL_TREE)
5166 local.field = ce->index;
5168 else if (TREE_CODE (local.type) == ARRAY_TYPE)
5169 local.index = ce->index;
5171 if (local.field && flag_verbose_asm)
5172 fprintf (asm_out_file, "%s %s:\n",
5173 ASM_COMMENT_START,
5174 DECL_NAME (local.field)
5175 ? IDENTIFIER_POINTER (DECL_NAME (local.field))
5176 : "<anonymous>");
5178 /* Eliminate the marker that makes a cast not be an lvalue. */
5179 if (local.val != NULL_TREE)
5180 STRIP_NOPS (local.val);
5182 /* Output the current element, using the appropriate helper ... */
5184 /* For an array slice not part of an outer bitfield. */
5185 if (!outer
5186 && local.index != NULL_TREE
5187 && TREE_CODE (local.index) == RANGE_EXPR)
5188 output_constructor_array_range (&local);
5190 /* For a field that is neither a true bitfield nor part of an outer one,
5191 known to be at least byte aligned and multiple-of-bytes long. */
5192 else if (!outer
5193 && (local.field == NULL_TREE
5194 || !CONSTRUCTOR_BITFIELD_P (local.field)))
5195 output_constructor_regular_field (&local);
5197 /* For a true bitfield or part of an outer one. Only INTEGER_CSTs are
5198 supported for scalar fields, so we may need to convert first. */
5199 else
5201 if (TREE_CODE (local.val) == REAL_CST)
5202 local.val
5203 = fold_unary (VIEW_CONVERT_EXPR,
5204 build_nonstandard_integer_type
5205 (TYPE_PRECISION (TREE_TYPE (local.val)), 0),
5206 local.val);
5207 output_constructor_bitfield (&local, outer ? outer->bit_offset : 0);
5211 /* If we are not at toplevel, save the pending data for our caller.
5212 Otherwise output the pending data and padding zeros as needed. */
5213 if (outer)
5214 outer->byte = local.byte;
5215 else
5217 if (local.byte_buffer_in_use)
5219 assemble_integer (GEN_INT (local.byte), 1, BITS_PER_UNIT, 1);
5220 local.total_bytes++;
5223 if ((unsigned HOST_WIDE_INT)local.total_bytes < local.size)
5225 assemble_zeros (local.size - local.total_bytes);
5226 local.total_bytes = local.size;
5230 return local.total_bytes;
5233 /* Mark DECL as weak. */
5235 static void
5236 mark_weak (tree decl)
5238 DECL_WEAK (decl) = 1;
5240 if (DECL_RTL_SET_P (decl)
5241 && MEM_P (DECL_RTL (decl))
5242 && XEXP (DECL_RTL (decl), 0)
5243 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF)
5244 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1;
5247 /* Merge weak status between NEWDECL and OLDDECL. */
5249 void
5250 merge_weak (tree newdecl, tree olddecl)
5252 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl))
5254 if (DECL_WEAK (newdecl) && TARGET_SUPPORTS_WEAK)
5256 tree *pwd;
5257 /* We put the NEWDECL on the weak_decls list at some point
5258 and OLDDECL as well. Keep just OLDDECL on the list. */
5259 for (pwd = &weak_decls; *pwd; pwd = &TREE_CHAIN (*pwd))
5260 if (TREE_VALUE (*pwd) == newdecl)
5262 *pwd = TREE_CHAIN (*pwd);
5263 break;
5266 return;
5269 if (DECL_WEAK (newdecl))
5271 tree wd;
5273 /* NEWDECL is weak, but OLDDECL is not. */
5275 /* If we already output the OLDDECL, we're in trouble; we can't
5276 go back and make it weak. This should never happen in
5277 unit-at-a-time compilation. */
5278 gcc_assert (!TREE_ASM_WRITTEN (olddecl));
5280 /* If we've already generated rtl referencing OLDDECL, we may
5281 have done so in a way that will not function properly with
5282 a weak symbol. Again in unit-at-a-time this should be
5283 impossible. */
5284 gcc_assert (!TREE_USED (olddecl)
5285 || !TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl)));
5287 if (TARGET_SUPPORTS_WEAK)
5289 /* We put the NEWDECL on the weak_decls list at some point.
5290 Replace it with the OLDDECL. */
5291 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd))
5292 if (TREE_VALUE (wd) == newdecl)
5294 TREE_VALUE (wd) = olddecl;
5295 break;
5297 /* We may not find the entry on the list. If NEWDECL is a
5298 weak alias, then we will have already called
5299 globalize_decl to remove the entry; in that case, we do
5300 not need to do anything. */
5303 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */
5304 mark_weak (olddecl);
5306 else
5307 /* OLDDECL was weak, but NEWDECL was not explicitly marked as
5308 weak. Just update NEWDECL to indicate that it's weak too. */
5309 mark_weak (newdecl);
5312 /* Declare DECL to be a weak symbol. */
5314 void
5315 declare_weak (tree decl)
5317 gcc_assert (TREE_CODE (decl) != FUNCTION_DECL || !TREE_ASM_WRITTEN (decl));
5318 if (! TREE_PUBLIC (decl))
5319 error ("weak declaration of %q+D must be public", decl);
5320 else if (!TARGET_SUPPORTS_WEAK)
5321 warning (0, "weak declaration of %q+D not supported", decl);
5323 mark_weak (decl);
5324 if (!lookup_attribute ("weak", DECL_ATTRIBUTES (decl)))
5325 DECL_ATTRIBUTES (decl)
5326 = tree_cons (get_identifier ("weak"), NULL, DECL_ATTRIBUTES (decl));
5329 static void
5330 weak_finish_1 (tree decl)
5332 #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL)
5333 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5334 #endif
5336 if (! TREE_USED (decl))
5337 return;
5339 #ifdef ASM_WEAKEN_DECL
5340 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL);
5341 #else
5342 #ifdef ASM_WEAKEN_LABEL
5343 ASM_WEAKEN_LABEL (asm_out_file, name);
5344 #else
5345 #ifdef ASM_OUTPUT_WEAK_ALIAS
5347 static bool warn_once = 0;
5348 if (! warn_once)
5350 warning (0, "only weak aliases are supported in this configuration");
5351 warn_once = 1;
5353 return;
5355 #endif
5356 #endif
5357 #endif
5360 /* Fiven an assembly name, find the decl it is associated with. */
5361 static tree
5362 find_decl (tree target)
5364 symtab_node *node = symtab_node_for_asm (target);
5365 if (node)
5366 return node->decl;
5367 return NULL_TREE;
5370 /* This TREE_LIST contains weakref targets. */
5372 static GTY(()) tree weakref_targets;
5374 /* Emit any pending weak declarations. */
5376 void
5377 weak_finish (void)
5379 tree t;
5381 for (t = weakref_targets; t; t = TREE_CHAIN (t))
5383 tree alias_decl = TREE_PURPOSE (t);
5384 tree target = ultimate_transparent_alias_target (&TREE_VALUE (t));
5386 if (! TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (alias_decl)))
5387 /* Remove alias_decl from the weak list, but leave entries for
5388 the target alone. */
5389 target = NULL_TREE;
5390 #ifndef ASM_OUTPUT_WEAKREF
5391 else if (! TREE_SYMBOL_REFERENCED (target))
5393 /* Use ASM_WEAKEN_LABEL only if ASM_WEAKEN_DECL is not
5394 defined, otherwise we and weak_finish_1 would use
5395 different macros. */
5396 # if defined ASM_WEAKEN_LABEL && ! defined ASM_WEAKEN_DECL
5397 ASM_WEAKEN_LABEL (asm_out_file, IDENTIFIER_POINTER (target));
5398 # else
5399 tree decl = find_decl (target);
5401 if (! decl)
5403 decl = build_decl (DECL_SOURCE_LOCATION (alias_decl),
5404 TREE_CODE (alias_decl), target,
5405 TREE_TYPE (alias_decl));
5407 DECL_EXTERNAL (decl) = 1;
5408 TREE_PUBLIC (decl) = 1;
5409 DECL_ARTIFICIAL (decl) = 1;
5410 TREE_NOTHROW (decl) = TREE_NOTHROW (alias_decl);
5411 TREE_USED (decl) = 1;
5414 weak_finish_1 (decl);
5415 # endif
5417 #endif
5420 tree *p;
5421 tree t2;
5423 /* Remove the alias and the target from the pending weak list
5424 so that we do not emit any .weak directives for the former,
5425 nor multiple .weak directives for the latter. */
5426 for (p = &weak_decls; (t2 = *p) ; )
5428 if (TREE_VALUE (t2) == alias_decl
5429 || target == DECL_ASSEMBLER_NAME (TREE_VALUE (t2)))
5430 *p = TREE_CHAIN (t2);
5431 else
5432 p = &TREE_CHAIN (t2);
5435 /* Remove other weakrefs to the same target, to speed things up. */
5436 for (p = &TREE_CHAIN (t); (t2 = *p) ; )
5438 if (target == ultimate_transparent_alias_target (&TREE_VALUE (t2)))
5439 *p = TREE_CHAIN (t2);
5440 else
5441 p = &TREE_CHAIN (t2);
5446 for (t = weak_decls; t; t = TREE_CHAIN (t))
5448 tree decl = TREE_VALUE (t);
5450 weak_finish_1 (decl);
5454 /* Emit the assembly bits to indicate that DECL is globally visible. */
5456 static void
5457 globalize_decl (tree decl)
5460 #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL)
5461 if (DECL_WEAK (decl))
5463 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
5464 tree *p, t;
5466 #ifdef ASM_WEAKEN_DECL
5467 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
5468 #else
5469 ASM_WEAKEN_LABEL (asm_out_file, name);
5470 #endif
5472 /* Remove this function from the pending weak list so that
5473 we do not emit multiple .weak directives for it. */
5474 for (p = &weak_decls; (t = *p) ; )
5476 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5477 *p = TREE_CHAIN (t);
5478 else
5479 p = &TREE_CHAIN (t);
5482 /* Remove weakrefs to the same target from the pending weakref
5483 list, for the same reason. */
5484 for (p = &weakref_targets; (t = *p) ; )
5486 if (DECL_ASSEMBLER_NAME (decl)
5487 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5488 *p = TREE_CHAIN (t);
5489 else
5490 p = &TREE_CHAIN (t);
5493 return;
5495 #endif
5497 targetm.asm_out.globalize_decl_name (asm_out_file, decl);
5500 vec<alias_pair, va_gc> *alias_pairs;
5502 /* Output the assembler code for a define (equate) using ASM_OUTPUT_DEF
5503 or ASM_OUTPUT_DEF_FROM_DECLS. The function defines the symbol whose
5504 tree node is DECL to have the value of the tree node TARGET. */
5506 void
5507 do_assemble_alias (tree decl, tree target)
5509 /* Emulated TLS had better not get this var. */
5510 gcc_assert (!(!targetm.have_tls
5511 && TREE_CODE (decl) == VAR_DECL
5512 && DECL_THREAD_LOCAL_P (decl)));
5514 if (TREE_ASM_WRITTEN (decl))
5515 return;
5517 /* We must force creation of DECL_RTL for debug info generation, even though
5518 we don't use it here. */
5519 make_decl_rtl (decl);
5521 TREE_ASM_WRITTEN (decl) = 1;
5522 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;
5524 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5526 ultimate_transparent_alias_target (&target);
5528 if (!TREE_SYMBOL_REFERENCED (target))
5529 weakref_targets = tree_cons (decl, target, weakref_targets);
5531 #ifdef ASM_OUTPUT_WEAKREF
5532 ASM_OUTPUT_WEAKREF (asm_out_file, decl,
5533 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5534 IDENTIFIER_POINTER (target));
5535 #else
5536 if (!TARGET_SUPPORTS_WEAK)
5538 error_at (DECL_SOURCE_LOCATION (decl),
5539 "weakref is not supported in this configuration");
5540 return;
5542 #endif
5543 return;
5546 #ifdef ASM_OUTPUT_DEF
5547 /* Make name accessible from other files, if appropriate. */
5549 if (TREE_PUBLIC (decl))
5551 globalize_decl (decl);
5552 maybe_assemble_visibility (decl);
5554 if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl)))
5556 #if defined (ASM_OUTPUT_TYPE_DIRECTIVE)
5557 if (targetm.has_ifunc_p ())
5558 ASM_OUTPUT_TYPE_DIRECTIVE
5559 (asm_out_file, IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5560 IFUNC_ASM_TYPE);
5561 else
5562 #endif
5563 error_at (DECL_SOURCE_LOCATION (decl),
5564 "ifunc is not supported on this target");
5567 # ifdef ASM_OUTPUT_DEF_FROM_DECLS
5568 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target);
5569 # else
5570 ASM_OUTPUT_DEF (asm_out_file,
5571 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5572 IDENTIFIER_POINTER (target));
5573 # endif
5574 #elif defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
5576 const char *name;
5577 tree *p, t;
5579 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5580 # ifdef ASM_WEAKEN_DECL
5581 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target));
5582 # else
5583 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
5584 # endif
5585 /* Remove this function from the pending weak list so that
5586 we do not emit multiple .weak directives for it. */
5587 for (p = &weak_decls; (t = *p) ; )
5588 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5589 *p = TREE_CHAIN (t);
5590 else
5591 p = &TREE_CHAIN (t);
5593 /* Remove weakrefs to the same target from the pending weakref
5594 list, for the same reason. */
5595 for (p = &weakref_targets; (t = *p) ; )
5597 if (DECL_ASSEMBLER_NAME (decl)
5598 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5599 *p = TREE_CHAIN (t);
5600 else
5601 p = &TREE_CHAIN (t);
5604 #endif
5607 /* Emit an assembler directive to make the symbol for DECL an alias to
5608 the symbol for TARGET. */
5610 void
5611 assemble_alias (tree decl, tree target)
5613 tree target_decl;
5615 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5617 tree alias = DECL_ASSEMBLER_NAME (decl);
5619 ultimate_transparent_alias_target (&target);
5621 if (alias == target)
5622 error ("weakref %q+D ultimately targets itself", decl);
5623 if (TREE_PUBLIC (decl))
5624 error ("weakref %q+D must have static linkage", decl);
5626 else
5628 #if !defined (ASM_OUTPUT_DEF)
5629 # if !defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL)
5630 error_at (DECL_SOURCE_LOCATION (decl),
5631 "alias definitions not supported in this configuration");
5632 TREE_ASM_WRITTEN (decl) = 1;
5633 return;
5634 # else
5635 if (!DECL_WEAK (decl))
5637 if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl)))
5638 error_at (DECL_SOURCE_LOCATION (decl),
5639 "ifunc is not supported in this configuration");
5640 else
5641 error_at (DECL_SOURCE_LOCATION (decl),
5642 "only weak aliases are supported in this configuration");
5643 TREE_ASM_WRITTEN (decl) = 1;
5644 return;
5646 # endif
5647 #endif
5649 TREE_USED (decl) = 1;
5651 /* Allow aliases to aliases. */
5652 if (TREE_CODE (decl) == FUNCTION_DECL)
5653 cgraph_node::get_create (decl)->alias = true;
5654 else
5655 varpool_node::get_create (decl)->alias = true;
5657 /* If the target has already been emitted, we don't have to queue the
5658 alias. This saves a tad of memory. */
5659 if (cgraph_global_info_ready)
5660 target_decl = find_decl (target);
5661 else
5662 target_decl= NULL;
5663 if ((target_decl && TREE_ASM_WRITTEN (target_decl))
5664 || cgraph_state >= CGRAPH_STATE_EXPANSION)
5665 do_assemble_alias (decl, target);
5666 else
5668 alias_pair p = {decl, target};
5669 vec_safe_push (alias_pairs, p);
5673 /* Record and output a table of translations from original function
5674 to its transaction aware clone. Note that tm_pure functions are
5675 considered to be their own clone. */
5677 static GTY((if_marked ("tree_map_marked_p"), param_is (struct tree_map)))
5678 htab_t tm_clone_hash;
5680 void
5681 record_tm_clone_pair (tree o, tree n)
5683 struct tree_map **slot, *h;
5685 if (tm_clone_hash == NULL)
5686 tm_clone_hash = htab_create_ggc (32, tree_map_hash, tree_map_eq, 0);
5688 h = ggc_alloc<tree_map> ();
5689 h->hash = htab_hash_pointer (o);
5690 h->base.from = o;
5691 h->to = n;
5693 slot = (struct tree_map **)
5694 htab_find_slot_with_hash (tm_clone_hash, h, h->hash, INSERT);
5695 *slot = h;
5698 tree
5699 get_tm_clone_pair (tree o)
5701 if (tm_clone_hash)
5703 struct tree_map *h, in;
5705 in.base.from = o;
5706 in.hash = htab_hash_pointer (o);
5707 h = (struct tree_map *) htab_find_with_hash (tm_clone_hash,
5708 &in, in.hash);
5709 if (h)
5710 return h->to;
5712 return NULL_TREE;
5715 typedef struct tm_alias_pair
5717 unsigned int uid;
5718 tree from;
5719 tree to;
5720 } tm_alias_pair;
5723 /* Helper function for finish_tm_clone_pairs. Dump a hash table entry
5724 into a VEC in INFO. */
5726 static int
5727 dump_tm_clone_to_vec (void **slot, void *info)
5729 struct tree_map *map = (struct tree_map *) *slot;
5730 vec<tm_alias_pair> *tm_alias_pairs = (vec<tm_alias_pair> *) info;
5731 tm_alias_pair p = {DECL_UID (map->base.from), map->base.from, map->to};
5732 tm_alias_pairs->safe_push (p);
5733 return 1;
5736 /* Dump the actual pairs to the .tm_clone_table section. */
5738 static void
5739 dump_tm_clone_pairs (vec<tm_alias_pair> tm_alias_pairs)
5741 unsigned i;
5742 tm_alias_pair *p;
5743 bool switched = false;
5745 FOR_EACH_VEC_ELT (tm_alias_pairs, i, p)
5747 tree src = p->from;
5748 tree dst = p->to;
5749 struct cgraph_node *src_n = cgraph_node::get (src);
5750 struct cgraph_node *dst_n = cgraph_node::get (dst);
5752 /* The function ipa_tm_create_version() marks the clone as needed if
5753 the original function was needed. But we also mark the clone as
5754 needed if we ever called the clone indirectly through
5755 TM_GETTMCLONE. If neither of these are true, we didn't generate
5756 a clone, and we didn't call it indirectly... no sense keeping it
5757 in the clone table. */
5758 if (!dst_n || !dst_n->definition)
5759 continue;
5761 /* This covers the case where we have optimized the original
5762 function away, and only access the transactional clone. */
5763 if (!src_n || !src_n->definition)
5764 continue;
5766 if (!switched)
5768 switch_to_section (targetm.asm_out.tm_clone_table_section ());
5769 assemble_align (POINTER_SIZE);
5770 switched = true;
5773 assemble_integer (XEXP (DECL_RTL (src), 0),
5774 POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
5775 assemble_integer (XEXP (DECL_RTL (dst), 0),
5776 POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
5780 /* Provide a default for the tm_clone_table section. */
5782 section *
5783 default_clone_table_section (void)
5785 return get_named_section (NULL, ".tm_clone_table", 3);
5788 /* Helper comparison function for qsorting by the DECL_UID stored in
5789 alias_pair->emitted_diags. */
5791 static int
5792 tm_alias_pair_cmp (const void *x, const void *y)
5794 const tm_alias_pair *p1 = (const tm_alias_pair *) x;
5795 const tm_alias_pair *p2 = (const tm_alias_pair *) y;
5796 if (p1->uid < p2->uid)
5797 return -1;
5798 if (p1->uid > p2->uid)
5799 return 1;
5800 return 0;
5803 void
5804 finish_tm_clone_pairs (void)
5806 vec<tm_alias_pair> tm_alias_pairs = vNULL;
5808 if (tm_clone_hash == NULL)
5809 return;
5811 /* We need a determenistic order for the .tm_clone_table, otherwise
5812 we will get bootstrap comparison failures, so dump the hash table
5813 to a vector, sort it, and dump the vector. */
5815 /* Dump the hashtable to a vector. */
5816 htab_traverse_noresize (tm_clone_hash, dump_tm_clone_to_vec,
5817 (void *) &tm_alias_pairs);
5818 /* Sort it. */
5819 tm_alias_pairs.qsort (tm_alias_pair_cmp);
5821 /* Dump it. */
5822 dump_tm_clone_pairs (tm_alias_pairs);
5824 htab_delete (tm_clone_hash);
5825 tm_clone_hash = NULL;
5826 tm_alias_pairs.release ();
5830 /* Emit an assembler directive to set symbol for DECL visibility to
5831 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */
5833 void
5834 default_assemble_visibility (tree decl ATTRIBUTE_UNUSED,
5835 int vis ATTRIBUTE_UNUSED)
5837 #ifdef HAVE_GAS_HIDDEN
5838 static const char * const visibility_types[] = {
5839 NULL, "protected", "hidden", "internal"
5842 const char *name, *type;
5844 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5845 type = visibility_types[vis];
5847 fprintf (asm_out_file, "\t.%s\t", type);
5848 assemble_name (asm_out_file, name);
5849 fprintf (asm_out_file, "\n");
5850 #else
5851 if (!DECL_ARTIFICIAL (decl))
5852 warning (OPT_Wattributes, "visibility attribute not supported "
5853 "in this configuration; ignored");
5854 #endif
5857 /* A helper function to call assemble_visibility when needed for a decl. */
5860 maybe_assemble_visibility (tree decl)
5862 enum symbol_visibility vis = DECL_VISIBILITY (decl);
5864 if (vis != VISIBILITY_DEFAULT)
5866 targetm.asm_out.assemble_visibility (decl, vis);
5867 return 1;
5869 else
5870 return 0;
5873 /* Returns 1 if the target configuration supports defining public symbols
5874 so that one of them will be chosen at link time instead of generating a
5875 multiply-defined symbol error, whether through the use of weak symbols or
5876 a target-specific mechanism for having duplicates discarded. */
5879 supports_one_only (void)
5881 if (SUPPORTS_ONE_ONLY)
5882 return 1;
5883 return TARGET_SUPPORTS_WEAK;
5886 /* Set up DECL as a public symbol that can be defined in multiple
5887 translation units without generating a linker error. */
5889 void
5890 make_decl_one_only (tree decl, tree comdat_group)
5892 struct symtab_node *symbol;
5893 gcc_assert (TREE_CODE (decl) == VAR_DECL
5894 || TREE_CODE (decl) == FUNCTION_DECL);
5896 TREE_PUBLIC (decl) = 1;
5898 if (TREE_CODE (decl) == VAR_DECL)
5899 symbol = varpool_node::get_create (decl);
5900 else
5901 symbol = cgraph_node::get_create (decl);
5903 if (SUPPORTS_ONE_ONLY)
5905 #ifdef MAKE_DECL_ONE_ONLY
5906 MAKE_DECL_ONE_ONLY (decl);
5907 #endif
5908 symbol->set_comdat_group (comdat_group);
5910 else if (TREE_CODE (decl) == VAR_DECL
5911 && (DECL_INITIAL (decl) == 0
5912 || (!in_lto_p && DECL_INITIAL (decl) == error_mark_node)))
5913 DECL_COMMON (decl) = 1;
5914 else
5916 gcc_assert (TARGET_SUPPORTS_WEAK);
5917 DECL_WEAK (decl) = 1;
5921 void
5922 init_varasm_once (void)
5924 section_htab = htab_create_ggc (31, section_entry_hash,
5925 section_entry_eq, NULL);
5926 object_block_htab = htab_create_ggc (31, object_block_entry_hash,
5927 object_block_entry_eq, NULL);
5928 const_desc_htab = htab_create_ggc (1009, const_desc_hash,
5929 const_desc_eq, NULL);
5931 const_alias_set = new_alias_set ();
5932 shared_constant_pool = create_constant_pool ();
5934 #ifdef TEXT_SECTION_ASM_OP
5935 text_section = get_unnamed_section (SECTION_CODE, output_section_asm_op,
5936 TEXT_SECTION_ASM_OP);
5937 #endif
5939 #ifdef DATA_SECTION_ASM_OP
5940 data_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5941 DATA_SECTION_ASM_OP);
5942 #endif
5944 #ifdef SDATA_SECTION_ASM_OP
5945 sdata_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5946 SDATA_SECTION_ASM_OP);
5947 #endif
5949 #ifdef READONLY_DATA_SECTION_ASM_OP
5950 readonly_data_section = get_unnamed_section (0, output_section_asm_op,
5951 READONLY_DATA_SECTION_ASM_OP);
5952 #endif
5954 #ifdef CTORS_SECTION_ASM_OP
5955 ctors_section = get_unnamed_section (0, output_section_asm_op,
5956 CTORS_SECTION_ASM_OP);
5957 #endif
5959 #ifdef DTORS_SECTION_ASM_OP
5960 dtors_section = get_unnamed_section (0, output_section_asm_op,
5961 DTORS_SECTION_ASM_OP);
5962 #endif
5964 #ifdef BSS_SECTION_ASM_OP
5965 bss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5966 output_section_asm_op,
5967 BSS_SECTION_ASM_OP);
5968 #endif
5970 #ifdef SBSS_SECTION_ASM_OP
5971 sbss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5972 output_section_asm_op,
5973 SBSS_SECTION_ASM_OP);
5974 #endif
5976 tls_comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5977 | SECTION_COMMON, emit_tls_common);
5978 lcomm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5979 | SECTION_COMMON, emit_local);
5980 comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5981 | SECTION_COMMON, emit_common);
5983 #if defined ASM_OUTPUT_ALIGNED_BSS
5984 bss_noswitch_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS,
5985 emit_bss);
5986 #endif
5988 targetm.asm_out.init_sections ();
5990 if (readonly_data_section == NULL)
5991 readonly_data_section = text_section;
5993 #ifdef ASM_OUTPUT_EXTERNAL
5994 pending_assemble_externals_set = new hash_set<tree>;
5995 #endif
5998 enum tls_model
5999 decl_default_tls_model (const_tree decl)
6001 enum tls_model kind;
6002 bool is_local;
6004 is_local = targetm.binds_local_p (decl);
6005 if (!flag_shlib)
6007 if (is_local)
6008 kind = TLS_MODEL_LOCAL_EXEC;
6009 else
6010 kind = TLS_MODEL_INITIAL_EXEC;
6013 /* Local dynamic is inefficient when we're not combining the
6014 parts of the address. */
6015 else if (optimize && is_local)
6016 kind = TLS_MODEL_LOCAL_DYNAMIC;
6017 else
6018 kind = TLS_MODEL_GLOBAL_DYNAMIC;
6019 if (kind < flag_tls_default)
6020 kind = flag_tls_default;
6022 return kind;
6025 /* Select a set of attributes for section NAME based on the properties
6026 of DECL and whether or not RELOC indicates that DECL's initializer
6027 might contain runtime relocations.
6029 We make the section read-only and executable for a function decl,
6030 read-only for a const data decl, and writable for a non-const data decl. */
6032 unsigned int
6033 default_section_type_flags (tree decl, const char *name, int reloc)
6035 unsigned int flags;
6037 if (decl && TREE_CODE (decl) == FUNCTION_DECL)
6038 flags = SECTION_CODE;
6039 else if (decl)
6041 enum section_category category
6042 = categorize_decl_for_section (decl, reloc);
6043 if (decl_readonly_section_1 (category))
6044 flags = 0;
6045 else if (category == SECCAT_DATA_REL_RO
6046 || category == SECCAT_DATA_REL_RO_LOCAL)
6047 flags = SECTION_WRITE | SECTION_RELRO;
6048 else
6049 flags = SECTION_WRITE;
6051 else
6053 flags = SECTION_WRITE;
6054 if (strcmp (name, ".data.rel.ro") == 0
6055 || strcmp (name, ".data.rel.ro.local") == 0)
6056 flags |= SECTION_RELRO;
6059 if (decl && DECL_P (decl) && DECL_COMDAT_GROUP (decl))
6060 flags |= SECTION_LINKONCE;
6062 if (strcmp (name, ".vtable_map_vars") == 0)
6063 flags |= SECTION_LINKONCE;
6065 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
6066 flags |= SECTION_TLS | SECTION_WRITE;
6068 if (strcmp (name, ".bss") == 0
6069 || strncmp (name, ".bss.", 5) == 0
6070 || strncmp (name, ".gnu.linkonce.b.", 16) == 0
6071 || strcmp (name, ".sbss") == 0
6072 || strncmp (name, ".sbss.", 6) == 0
6073 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0)
6074 flags |= SECTION_BSS;
6076 if (strcmp (name, ".tdata") == 0
6077 || strncmp (name, ".tdata.", 7) == 0
6078 || strncmp (name, ".gnu.linkonce.td.", 17) == 0)
6079 flags |= SECTION_TLS;
6081 if (strcmp (name, ".tbss") == 0
6082 || strncmp (name, ".tbss.", 6) == 0
6083 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
6084 flags |= SECTION_TLS | SECTION_BSS;
6086 /* These three sections have special ELF types. They are neither
6087 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't
6088 want to print a section type (@progbits or @nobits). If someone
6089 is silly enough to emit code or TLS variables to one of these
6090 sections, then don't handle them specially. */
6091 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS))
6092 && (strcmp (name, ".init_array") == 0
6093 || strcmp (name, ".fini_array") == 0
6094 || strcmp (name, ".preinit_array") == 0))
6095 flags |= SECTION_NOTYPE;
6097 return flags;
6100 /* Return true if the target supports some form of global BSS,
6101 either through bss_noswitch_section, or by selecting a BSS
6102 section in TARGET_ASM_SELECT_SECTION. */
6104 bool
6105 have_global_bss_p (void)
6107 return bss_noswitch_section || targetm.have_switchable_bss_sections;
6110 /* Output assembly to switch to section NAME with attribute FLAGS.
6111 Four variants for common object file formats. */
6113 void
6114 default_no_named_section (const char *name ATTRIBUTE_UNUSED,
6115 unsigned int flags ATTRIBUTE_UNUSED,
6116 tree decl ATTRIBUTE_UNUSED)
6118 /* Some object formats don't support named sections at all. The
6119 front-end should already have flagged this as an error. */
6120 gcc_unreachable ();
6123 #ifndef TLS_SECTION_ASM_FLAG
6124 #define TLS_SECTION_ASM_FLAG 'T'
6125 #endif
6127 void
6128 default_elf_asm_named_section (const char *name, unsigned int flags,
6129 tree decl ATTRIBUTE_UNUSED)
6131 char flagchars[10], *f = flagchars;
6133 /* If we have already declared this section, we can use an
6134 abbreviated form to switch back to it -- unless this section is
6135 part of a COMDAT groups, in which case GAS requires the full
6136 declaration every time. */
6137 if (!(HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
6138 && (flags & SECTION_DECLARED))
6140 fprintf (asm_out_file, "\t.section\t%s\n", name);
6141 return;
6144 if (!(flags & SECTION_DEBUG))
6145 *f++ = 'a';
6146 if (flags & SECTION_EXCLUDE)
6147 *f++ = 'e';
6148 if (flags & SECTION_WRITE)
6149 *f++ = 'w';
6150 if (flags & SECTION_CODE)
6151 *f++ = 'x';
6152 if (flags & SECTION_SMALL)
6153 *f++ = 's';
6154 if (flags & SECTION_MERGE)
6155 *f++ = 'M';
6156 if (flags & SECTION_STRINGS)
6157 *f++ = 'S';
6158 if (flags & SECTION_TLS)
6159 *f++ = TLS_SECTION_ASM_FLAG;
6160 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
6161 *f++ = 'G';
6162 *f = '\0';
6164 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);
6166 if (!(flags & SECTION_NOTYPE))
6168 const char *type;
6169 const char *format;
6171 if (flags & SECTION_BSS)
6172 type = "nobits";
6173 else
6174 type = "progbits";
6176 format = ",@%s";
6177 /* On platforms that use "@" as the assembly comment character,
6178 use "%" instead. */
6179 if (strcmp (ASM_COMMENT_START, "@") == 0)
6180 format = ",%%%s";
6181 fprintf (asm_out_file, format, type);
6183 if (flags & SECTION_ENTSIZE)
6184 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
6185 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
6187 if (TREE_CODE (decl) == IDENTIFIER_NODE)
6188 fprintf (asm_out_file, ",%s,comdat", IDENTIFIER_POINTER (decl));
6189 else
6190 fprintf (asm_out_file, ",%s,comdat",
6191 IDENTIFIER_POINTER (DECL_COMDAT_GROUP (decl)));
6195 putc ('\n', asm_out_file);
6198 void
6199 default_coff_asm_named_section (const char *name, unsigned int flags,
6200 tree decl ATTRIBUTE_UNUSED)
6202 char flagchars[8], *f = flagchars;
6204 if (flags & SECTION_WRITE)
6205 *f++ = 'w';
6206 if (flags & SECTION_CODE)
6207 *f++ = 'x';
6208 *f = '\0';
6210 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);
6213 void
6214 default_pe_asm_named_section (const char *name, unsigned int flags,
6215 tree decl)
6217 default_coff_asm_named_section (name, flags, decl);
6219 if (flags & SECTION_LINKONCE)
6221 /* Functions may have been compiled at various levels of
6222 optimization so we can't use `same_size' here.
6223 Instead, have the linker pick one. */
6224 fprintf (asm_out_file, "\t.linkonce %s\n",
6225 (flags & SECTION_CODE ? "discard" : "same_size"));
6229 /* The lame default section selector. */
6231 section *
6232 default_select_section (tree decl, int reloc,
6233 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
6235 if (DECL_P (decl))
6237 if (decl_readonly_section (decl, reloc))
6238 return readonly_data_section;
6240 else if (TREE_CODE (decl) == CONSTRUCTOR)
6242 if (! ((flag_pic && reloc)
6243 || !TREE_READONLY (decl)
6244 || TREE_SIDE_EFFECTS (decl)
6245 || !TREE_CONSTANT (decl)))
6246 return readonly_data_section;
6248 else if (TREE_CODE (decl) == STRING_CST)
6249 return readonly_data_section;
6250 else if (! (flag_pic && reloc))
6251 return readonly_data_section;
6253 return data_section;
6256 enum section_category
6257 categorize_decl_for_section (const_tree decl, int reloc)
6259 enum section_category ret;
6261 if (TREE_CODE (decl) == FUNCTION_DECL)
6262 return SECCAT_TEXT;
6263 else if (TREE_CODE (decl) == STRING_CST)
6265 if ((flag_sanitize & SANITIZE_ADDRESS)
6266 && asan_protect_global (CONST_CAST_TREE (decl)))
6267 /* or !flag_merge_constants */
6268 return SECCAT_RODATA;
6269 else
6270 return SECCAT_RODATA_MERGE_STR;
6272 else if (TREE_CODE (decl) == VAR_DECL)
6274 if (bss_initializer_p (decl))
6275 ret = SECCAT_BSS;
6276 else if (! TREE_READONLY (decl)
6277 || TREE_SIDE_EFFECTS (decl)
6278 || ! TREE_CONSTANT (DECL_INITIAL (decl)))
6280 /* Here the reloc_rw_mask is not testing whether the section should
6281 be read-only or not, but whether the dynamic link will have to
6282 do something. If so, we wish to segregate the data in order to
6283 minimize cache misses inside the dynamic linker. */
6284 if (reloc & targetm.asm_out.reloc_rw_mask ())
6285 ret = reloc == 1 ? SECCAT_DATA_REL_LOCAL : SECCAT_DATA_REL;
6286 else
6287 ret = SECCAT_DATA;
6289 else if (reloc & targetm.asm_out.reloc_rw_mask ())
6290 ret = reloc == 1 ? SECCAT_DATA_REL_RO_LOCAL : SECCAT_DATA_REL_RO;
6291 else if (reloc || flag_merge_constants < 2
6292 || ((flag_sanitize & SANITIZE_ADDRESS)
6293 && asan_protect_global (CONST_CAST_TREE (decl))))
6294 /* C and C++ don't allow different variables to share the same
6295 location. -fmerge-all-constants allows even that (at the
6296 expense of not conforming). */
6297 ret = SECCAT_RODATA;
6298 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST)
6299 ret = SECCAT_RODATA_MERGE_STR_INIT;
6300 else
6301 ret = SECCAT_RODATA_MERGE_CONST;
6303 else if (TREE_CODE (decl) == CONSTRUCTOR)
6305 if ((reloc & targetm.asm_out.reloc_rw_mask ())
6306 || TREE_SIDE_EFFECTS (decl)
6307 || ! TREE_CONSTANT (decl))
6308 ret = SECCAT_DATA;
6309 else
6310 ret = SECCAT_RODATA;
6312 else
6313 ret = SECCAT_RODATA;
6315 /* There are no read-only thread-local sections. */
6316 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
6318 /* Note that this would be *just* SECCAT_BSS, except that there's
6319 no concept of a read-only thread-local-data section. */
6320 if (ret == SECCAT_BSS
6321 || (flag_zero_initialized_in_bss
6322 && initializer_zerop (DECL_INITIAL (decl))))
6323 ret = SECCAT_TBSS;
6324 else
6325 ret = SECCAT_TDATA;
6328 /* If the target uses small data sections, select it. */
6329 else if (targetm.in_small_data_p (decl))
6331 if (ret == SECCAT_BSS)
6332 ret = SECCAT_SBSS;
6333 else if (targetm.have_srodata_section && ret == SECCAT_RODATA)
6334 ret = SECCAT_SRODATA;
6335 else
6336 ret = SECCAT_SDATA;
6339 return ret;
6342 static bool
6343 decl_readonly_section_1 (enum section_category category)
6345 switch (category)
6347 case SECCAT_RODATA:
6348 case SECCAT_RODATA_MERGE_STR:
6349 case SECCAT_RODATA_MERGE_STR_INIT:
6350 case SECCAT_RODATA_MERGE_CONST:
6351 case SECCAT_SRODATA:
6352 return true;
6353 default:
6354 return false;
6358 bool
6359 decl_readonly_section (const_tree decl, int reloc)
6361 return decl_readonly_section_1 (categorize_decl_for_section (decl, reloc));
6364 /* Select a section based on the above categorization. */
6366 section *
6367 default_elf_select_section (tree decl, int reloc,
6368 unsigned HOST_WIDE_INT align)
6370 const char *sname;
6371 switch (categorize_decl_for_section (decl, reloc))
6373 case SECCAT_TEXT:
6374 /* We're not supposed to be called on FUNCTION_DECLs. */
6375 gcc_unreachable ();
6376 case SECCAT_RODATA:
6377 return readonly_data_section;
6378 case SECCAT_RODATA_MERGE_STR:
6379 return mergeable_string_section (decl, align, 0);
6380 case SECCAT_RODATA_MERGE_STR_INIT:
6381 return mergeable_string_section (DECL_INITIAL (decl), align, 0);
6382 case SECCAT_RODATA_MERGE_CONST:
6383 return mergeable_constant_section (DECL_MODE (decl), align, 0);
6384 case SECCAT_SRODATA:
6385 sname = ".sdata2";
6386 break;
6387 case SECCAT_DATA:
6388 return data_section;
6389 case SECCAT_DATA_REL:
6390 sname = ".data.rel";
6391 break;
6392 case SECCAT_DATA_REL_LOCAL:
6393 sname = ".data.rel.local";
6394 break;
6395 case SECCAT_DATA_REL_RO:
6396 sname = ".data.rel.ro";
6397 break;
6398 case SECCAT_DATA_REL_RO_LOCAL:
6399 sname = ".data.rel.ro.local";
6400 break;
6401 case SECCAT_SDATA:
6402 sname = ".sdata";
6403 break;
6404 case SECCAT_TDATA:
6405 sname = ".tdata";
6406 break;
6407 case SECCAT_BSS:
6408 if (bss_section)
6409 return bss_section;
6410 sname = ".bss";
6411 break;
6412 case SECCAT_SBSS:
6413 sname = ".sbss";
6414 break;
6415 case SECCAT_TBSS:
6416 sname = ".tbss";
6417 break;
6418 default:
6419 gcc_unreachable ();
6422 return get_named_section (decl, sname, reloc);
6425 /* Construct a unique section name based on the decl name and the
6426 categorization performed above. */
6428 void
6429 default_unique_section (tree decl, int reloc)
6431 /* We only need to use .gnu.linkonce if we don't have COMDAT groups. */
6432 bool one_only = DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP;
6433 const char *prefix, *name, *linkonce;
6434 char *string;
6436 switch (categorize_decl_for_section (decl, reloc))
6438 case SECCAT_TEXT:
6439 prefix = one_only ? ".t" : ".text";
6440 break;
6441 case SECCAT_RODATA:
6442 case SECCAT_RODATA_MERGE_STR:
6443 case SECCAT_RODATA_MERGE_STR_INIT:
6444 case SECCAT_RODATA_MERGE_CONST:
6445 prefix = one_only ? ".r" : ".rodata";
6446 break;
6447 case SECCAT_SRODATA:
6448 prefix = one_only ? ".s2" : ".sdata2";
6449 break;
6450 case SECCAT_DATA:
6451 prefix = one_only ? ".d" : ".data";
6452 break;
6453 case SECCAT_DATA_REL:
6454 prefix = one_only ? ".d.rel" : ".data.rel";
6455 break;
6456 case SECCAT_DATA_REL_LOCAL:
6457 prefix = one_only ? ".d.rel.local" : ".data.rel.local";
6458 break;
6459 case SECCAT_DATA_REL_RO:
6460 prefix = one_only ? ".d.rel.ro" : ".data.rel.ro";
6461 break;
6462 case SECCAT_DATA_REL_RO_LOCAL:
6463 prefix = one_only ? ".d.rel.ro.local" : ".data.rel.ro.local";
6464 break;
6465 case SECCAT_SDATA:
6466 prefix = one_only ? ".s" : ".sdata";
6467 break;
6468 case SECCAT_BSS:
6469 prefix = one_only ? ".b" : ".bss";
6470 break;
6471 case SECCAT_SBSS:
6472 prefix = one_only ? ".sb" : ".sbss";
6473 break;
6474 case SECCAT_TDATA:
6475 prefix = one_only ? ".td" : ".tdata";
6476 break;
6477 case SECCAT_TBSS:
6478 prefix = one_only ? ".tb" : ".tbss";
6479 break;
6480 default:
6481 gcc_unreachable ();
6484 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
6485 name = targetm.strip_name_encoding (name);
6487 /* If we're using one_only, then there needs to be a .gnu.linkonce
6488 prefix to the section name. */
6489 linkonce = one_only ? ".gnu.linkonce" : "";
6491 string = ACONCAT ((linkonce, prefix, ".", name, NULL));
6493 set_decl_section_name (decl, string);
6496 /* Like compute_reloc_for_constant, except for an RTX. The return value
6497 is a mask for which bit 1 indicates a global relocation, and bit 0
6498 indicates a local relocation. */
6500 static int
6501 compute_reloc_for_rtx_1 (rtx *xp, void *data)
6503 int *preloc = (int *) data;
6504 rtx x = *xp;
6506 switch (GET_CODE (x))
6508 case SYMBOL_REF:
6509 *preloc |= SYMBOL_REF_LOCAL_P (x) ? 1 : 2;
6510 break;
6511 case LABEL_REF:
6512 *preloc |= 1;
6513 break;
6514 default:
6515 break;
6518 return 0;
6521 static int
6522 compute_reloc_for_rtx (rtx x)
6524 int reloc;
6526 switch (GET_CODE (x))
6528 case CONST:
6529 case SYMBOL_REF:
6530 case LABEL_REF:
6531 reloc = 0;
6532 for_each_rtx (&x, compute_reloc_for_rtx_1, &reloc);
6533 return reloc;
6535 default:
6536 return 0;
6540 section *
6541 default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED,
6542 rtx x,
6543 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
6545 if (compute_reloc_for_rtx (x) & targetm.asm_out.reloc_rw_mask ())
6546 return data_section;
6547 else
6548 return readonly_data_section;
6551 section *
6552 default_elf_select_rtx_section (enum machine_mode mode, rtx x,
6553 unsigned HOST_WIDE_INT align)
6555 int reloc = compute_reloc_for_rtx (x);
6557 /* ??? Handle small data here somehow. */
6559 if (reloc & targetm.asm_out.reloc_rw_mask ())
6561 if (reloc == 1)
6562 return get_named_section (NULL, ".data.rel.ro.local", 1);
6563 else
6564 return get_named_section (NULL, ".data.rel.ro", 3);
6567 return mergeable_constant_section (mode, align, 0);
6570 /* Set the generally applicable flags on the SYMBOL_REF for EXP. */
6572 void
6573 default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
6575 rtx symbol;
6576 int flags;
6578 /* Careful not to prod global register variables. */
6579 if (!MEM_P (rtl))
6580 return;
6581 symbol = XEXP (rtl, 0);
6582 if (GET_CODE (symbol) != SYMBOL_REF)
6583 return;
6585 flags = SYMBOL_REF_FLAGS (symbol) & SYMBOL_FLAG_HAS_BLOCK_INFO;
6586 if (TREE_CODE (decl) == FUNCTION_DECL)
6587 flags |= SYMBOL_FLAG_FUNCTION;
6588 if (targetm.binds_local_p (decl))
6589 flags |= SYMBOL_FLAG_LOCAL;
6590 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
6591 flags |= DECL_TLS_MODEL (decl) << SYMBOL_FLAG_TLS_SHIFT;
6592 else if (targetm.in_small_data_p (decl))
6593 flags |= SYMBOL_FLAG_SMALL;
6594 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without
6595 being PUBLIC, the thing *must* be defined in this translation unit.
6596 Prevent this buglet from being propagated into rtl code as well. */
6597 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
6598 flags |= SYMBOL_FLAG_EXTERNAL;
6600 SYMBOL_REF_FLAGS (symbol) = flags;
6603 /* By default, we do nothing for encode_section_info, so we need not
6604 do anything but discard the '*' marker. */
6606 const char *
6607 default_strip_name_encoding (const char *str)
6609 return str + (*str == '*');
6612 #ifdef ASM_OUTPUT_DEF
6613 /* The default implementation of TARGET_ASM_OUTPUT_ANCHOR. Define the
6614 anchor relative to ".", the current section position. */
6616 void
6617 default_asm_output_anchor (rtx symbol)
6619 char buffer[100];
6621 sprintf (buffer, "*. + " HOST_WIDE_INT_PRINT_DEC,
6622 SYMBOL_REF_BLOCK_OFFSET (symbol));
6623 ASM_OUTPUT_DEF (asm_out_file, XSTR (symbol, 0), buffer);
6625 #endif
6627 /* The default implementation of TARGET_USE_ANCHORS_FOR_SYMBOL_P. */
6629 bool
6630 default_use_anchors_for_symbol_p (const_rtx symbol)
6632 section *sect;
6633 tree decl;
6635 /* Don't use anchors for mergeable sections. The linker might move
6636 the objects around. */
6637 sect = SYMBOL_REF_BLOCK (symbol)->sect;
6638 if (sect->common.flags & SECTION_MERGE)
6639 return false;
6641 /* Don't use anchors for small data sections. The small data register
6642 acts as an anchor for such sections. */
6643 if (sect->common.flags & SECTION_SMALL)
6644 return false;
6646 decl = SYMBOL_REF_DECL (symbol);
6647 if (decl && DECL_P (decl))
6649 /* Don't use section anchors for decls that might be defined or
6650 usurped by other modules. */
6651 if (TREE_PUBLIC (decl) && !decl_binds_to_current_def_p (decl))
6652 return false;
6654 /* Don't use section anchors for decls that will be placed in a
6655 small data section. */
6656 /* ??? Ideally, this check would be redundant with the SECTION_SMALL
6657 one above. The problem is that we only use SECTION_SMALL for
6658 sections that should be marked as small in the section directive. */
6659 if (targetm.in_small_data_p (decl))
6660 return false;
6662 return true;
6665 /* Return true when RESOLUTION indicate that symbol will be bound to the
6666 definition provided by current .o file. */
6668 static bool
6669 resolution_to_local_definition_p (enum ld_plugin_symbol_resolution resolution)
6671 return (resolution == LDPR_PREVAILING_DEF
6672 || resolution == LDPR_PREVAILING_DEF_IRONLY_EXP
6673 || resolution == LDPR_PREVAILING_DEF_IRONLY);
6676 /* Return true when RESOLUTION indicate that symbol will be bound locally
6677 within current executable or DSO. */
6679 static bool
6680 resolution_local_p (enum ld_plugin_symbol_resolution resolution)
6682 return (resolution == LDPR_PREVAILING_DEF
6683 || resolution == LDPR_PREVAILING_DEF_IRONLY
6684 || resolution == LDPR_PREVAILING_DEF_IRONLY_EXP
6685 || resolution == LDPR_PREEMPTED_REG
6686 || resolution == LDPR_PREEMPTED_IR
6687 || resolution == LDPR_RESOLVED_IR
6688 || resolution == LDPR_RESOLVED_EXEC);
6691 /* Assume ELF-ish defaults, since that's pretty much the most liberal
6692 wrt cross-module name binding. */
6694 bool
6695 default_binds_local_p (const_tree exp)
6697 return default_binds_local_p_1 (exp, flag_shlib);
6700 bool
6701 default_binds_local_p_1 (const_tree exp, int shlib)
6703 bool local_p;
6704 bool resolved_locally = false;
6705 bool resolved_to_local_def = false;
6707 /* With resolution file in hands, take look into resolutions.
6708 We can't just return true for resolved_locally symbols,
6709 because dynamic linking might overwrite symbols
6710 in shared libraries. */
6711 if (TREE_CODE (exp) == VAR_DECL && TREE_PUBLIC (exp)
6712 && (TREE_STATIC (exp) || DECL_EXTERNAL (exp)))
6714 varpool_node *vnode = varpool_node::get (exp);
6715 if (vnode && (resolution_local_p (vnode->resolution) || vnode->in_other_partition))
6716 resolved_locally = true;
6717 if (vnode
6718 && resolution_to_local_definition_p (vnode->resolution))
6719 resolved_to_local_def = true;
6721 else if (TREE_CODE (exp) == FUNCTION_DECL && TREE_PUBLIC (exp))
6723 struct cgraph_node *node = cgraph_node::get (exp);
6724 if (node
6725 && (resolution_local_p (node->resolution) || node->in_other_partition))
6726 resolved_locally = true;
6727 if (node
6728 && resolution_to_local_definition_p (node->resolution))
6729 resolved_to_local_def = true;
6732 /* A non-decl is an entry in the constant pool. */
6733 if (!DECL_P (exp))
6734 local_p = true;
6735 /* Weakrefs may not bind locally, even though the weakref itself is always
6736 static and therefore local. Similarly, the resolver for ifunc functions
6737 might resolve to a non-local function.
6738 FIXME: We can resolve the weakref case more curefuly by looking at the
6739 weakref alias. */
6740 else if (lookup_attribute ("weakref", DECL_ATTRIBUTES (exp))
6741 || (TREE_CODE (exp) == FUNCTION_DECL
6742 && lookup_attribute ("ifunc", DECL_ATTRIBUTES (exp))))
6743 local_p = false;
6744 /* Static variables are always local. */
6745 else if (! TREE_PUBLIC (exp))
6746 local_p = true;
6747 /* A variable is local if the user has said explicitly that it will
6748 be. */
6749 else if ((DECL_VISIBILITY_SPECIFIED (exp)
6750 || resolved_to_local_def)
6751 && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6752 local_p = true;
6753 /* Variables defined outside this object might not be local. */
6754 else if (DECL_EXTERNAL (exp) && !resolved_locally)
6755 local_p = false;
6756 /* If defined in this object and visibility is not default, must be
6757 local. */
6758 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6759 local_p = true;
6760 /* Default visibility weak data can be overridden by a strong symbol
6761 in another module and so are not local. */
6762 else if (DECL_WEAK (exp)
6763 && !resolved_locally)
6764 local_p = false;
6765 /* If PIC, then assume that any global name can be overridden by
6766 symbols resolved from other modules. */
6767 else if (shlib)
6768 local_p = false;
6769 /* Uninitialized COMMON variable may be unified with symbols
6770 resolved from other modules. */
6771 else if (DECL_COMMON (exp)
6772 && !resolved_locally
6773 && (DECL_INITIAL (exp) == NULL
6774 || (!in_lto_p && DECL_INITIAL (exp) == error_mark_node)))
6775 local_p = false;
6776 /* Otherwise we're left with initialized (or non-common) global data
6777 which is of necessity defined locally. */
6778 else
6779 local_p = true;
6781 return local_p;
6784 /* Return true when references to DECL must bind to current definition in
6785 final executable.
6787 The condition is usually equivalent to whether the function binds to the
6788 current module (shared library or executable), that is to binds_local_p.
6789 We use this fact to avoid need for another target hook and implement
6790 the logic using binds_local_p and just special cases where
6791 decl_binds_to_current_def_p is stronger than binds_local_p. In particular
6792 the weak definitions (that can be overwritten at linktime by other
6793 definition from different object file) and when resolution info is available
6794 we simply use the knowledge passed to us by linker plugin. */
6795 bool
6796 decl_binds_to_current_def_p (const_tree decl)
6798 gcc_assert (DECL_P (decl));
6799 if (!targetm.binds_local_p (decl))
6800 return false;
6801 if (!TREE_PUBLIC (decl))
6802 return true;
6803 /* When resolution is available, just use it. */
6804 if (TREE_CODE (decl) == VAR_DECL
6805 && (TREE_STATIC (decl) || DECL_EXTERNAL (decl)))
6807 varpool_node *vnode = varpool_node::get (decl);
6808 if (vnode
6809 && vnode->resolution != LDPR_UNKNOWN)
6810 return resolution_to_local_definition_p (vnode->resolution);
6812 else if (TREE_CODE (decl) == FUNCTION_DECL)
6814 struct cgraph_node *node = cgraph_node::get (decl);
6815 if (node
6816 && node->resolution != LDPR_UNKNOWN)
6817 return resolution_to_local_definition_p (node->resolution);
6819 /* Otherwise we have to assume the worst for DECL_WEAK (hidden weaks
6820 binds locally but still can be overwritten), DECL_COMMON (can be merged
6821 with a non-common definition somewhere in the same module) or
6822 DECL_EXTERNAL.
6823 This rely on fact that binds_local_p behave as decl_replaceable_p
6824 for all other declaration types. */
6825 if (DECL_WEAK (decl))
6826 return false;
6827 if (DECL_COMMON (decl)
6828 && (DECL_INITIAL (decl) == NULL
6829 || (!in_lto_p && DECL_INITIAL (decl) == error_mark_node)))
6830 return false;
6831 if (DECL_EXTERNAL (decl))
6832 return false;
6833 return true;
6836 /* A replaceable function or variable is one which may be replaced
6837 at link-time with an entirely different definition, provided that the
6838 replacement has the same type. For example, functions declared
6839 with __attribute__((weak)) on most systems are replaceable.
6841 COMDAT functions are not replaceable, since all definitions of the
6842 function must be equivalent. It is important that COMDAT functions
6843 not be treated as replaceable so that use of C++ template
6844 instantiations is not penalized. */
6846 bool
6847 decl_replaceable_p (tree decl)
6849 gcc_assert (DECL_P (decl));
6850 if (!TREE_PUBLIC (decl) || DECL_COMDAT (decl))
6851 return false;
6852 if (!flag_semantic_interposition
6853 && !DECL_WEAK (decl))
6854 return false;
6855 return !decl_binds_to_current_def_p (decl);
6858 /* Default function to output code that will globalize a label. A
6859 target must define GLOBAL_ASM_OP or provide its own function to
6860 globalize a label. */
6861 #ifdef GLOBAL_ASM_OP
6862 void
6863 default_globalize_label (FILE * stream, const char *name)
6865 fputs (GLOBAL_ASM_OP, stream);
6866 assemble_name (stream, name);
6867 putc ('\n', stream);
6869 #endif /* GLOBAL_ASM_OP */
6871 /* Default function to output code that will globalize a declaration. */
6872 void
6873 default_globalize_decl_name (FILE * stream, tree decl)
6875 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
6876 targetm.asm_out.globalize_label (stream, name);
6879 /* Default function to output a label for unwind information. The
6880 default is to do nothing. A target that needs nonlocal labels for
6881 unwind information must provide its own function to do this. */
6882 void
6883 default_emit_unwind_label (FILE * stream ATTRIBUTE_UNUSED,
6884 tree decl ATTRIBUTE_UNUSED,
6885 int for_eh ATTRIBUTE_UNUSED,
6886 int empty ATTRIBUTE_UNUSED)
6890 /* Default function to output a label to divide up the exception table.
6891 The default is to do nothing. A target that needs/wants to divide
6892 up the table must provide it's own function to do this. */
6893 void
6894 default_emit_except_table_label (FILE * stream ATTRIBUTE_UNUSED)
6898 /* This is how to output an internal numbered label where PREFIX is
6899 the class of label and LABELNO is the number within the class. */
6901 void
6902 default_generate_internal_label (char *buf, const char *prefix,
6903 unsigned long labelno)
6905 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
6908 /* This is how to output an internal numbered label where PREFIX is
6909 the class of label and LABELNO is the number within the class. */
6911 void
6912 default_internal_label (FILE *stream, const char *prefix,
6913 unsigned long labelno)
6915 char *const buf = (char *) alloca (40 + strlen (prefix));
6916 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
6917 ASM_OUTPUT_INTERNAL_LABEL (stream, buf);
6921 /* The default implementation of ASM_DECLARE_CONSTANT_NAME. */
6923 void
6924 default_asm_declare_constant_name (FILE *file, const char *name,
6925 const_tree exp ATTRIBUTE_UNUSED,
6926 HOST_WIDE_INT size ATTRIBUTE_UNUSED)
6928 assemble_label (file, name);
6931 /* This is the default behavior at the beginning of a file. It's
6932 controlled by two other target-hook toggles. */
6933 void
6934 default_file_start (void)
6936 if (targetm.asm_file_start_app_off
6937 && !(flag_verbose_asm || flag_debug_asm || flag_dump_rtl_in_asm))
6938 fputs (ASM_APP_OFF, asm_out_file);
6940 if (targetm.asm_file_start_file_directive)
6941 output_file_directive (asm_out_file, main_input_filename);
6944 /* This is a generic routine suitable for use as TARGET_ASM_FILE_END
6945 which emits a special section directive used to indicate whether or
6946 not this object file needs an executable stack. This is primarily
6947 a GNU extension to ELF but could be used on other targets. */
6949 int trampolines_created;
6951 void
6952 file_end_indicate_exec_stack (void)
6954 unsigned int flags = SECTION_DEBUG;
6955 if (trampolines_created)
6956 flags |= SECTION_CODE;
6958 switch_to_section (get_section (".note.GNU-stack", flags, NULL));
6961 /* Emit a special section directive to indicate that this object file
6962 was compiled with -fsplit-stack. This is used to let the linker
6963 detect calls between split-stack code and non-split-stack code, so
6964 that it can modify the split-stack code to allocate a sufficiently
6965 large stack. We emit another special section if there are any
6966 functions in this file which have the no_split_stack attribute, to
6967 prevent the linker from warning about being unable to convert the
6968 functions if they call non-split-stack code. */
6970 void
6971 file_end_indicate_split_stack (void)
6973 if (flag_split_stack)
6975 switch_to_section (get_section (".note.GNU-split-stack", SECTION_DEBUG,
6976 NULL));
6977 if (saw_no_split_stack)
6978 switch_to_section (get_section (".note.GNU-no-split-stack",
6979 SECTION_DEBUG, NULL));
6983 /* Output DIRECTIVE (a C string) followed by a newline. This is used as
6984 a get_unnamed_section callback. */
6986 void
6987 output_section_asm_op (const void *directive)
6989 fprintf (asm_out_file, "%s\n", (const char *) directive);
6992 /* Emit assembly code to switch to section NEW_SECTION. Do nothing if
6993 the current section is NEW_SECTION. */
6995 void
6996 switch_to_section (section *new_section)
6998 if (in_section == new_section)
6999 return;
7001 if (new_section->common.flags & SECTION_FORGET)
7002 in_section = NULL;
7003 else
7004 in_section = new_section;
7006 switch (SECTION_STYLE (new_section))
7008 case SECTION_NAMED:
7009 targetm.asm_out.named_section (new_section->named.name,
7010 new_section->named.common.flags,
7011 new_section->named.decl);
7012 break;
7014 case SECTION_UNNAMED:
7015 new_section->unnamed.callback (new_section->unnamed.data);
7016 break;
7018 case SECTION_NOSWITCH:
7019 gcc_unreachable ();
7020 break;
7023 new_section->common.flags |= SECTION_DECLARED;
7026 /* If block symbol SYMBOL has not yet been assigned an offset, place
7027 it at the end of its block. */
7029 void
7030 place_block_symbol (rtx symbol)
7032 unsigned HOST_WIDE_INT size, mask, offset;
7033 struct constant_descriptor_rtx *desc;
7034 unsigned int alignment;
7035 struct object_block *block;
7036 tree decl;
7038 gcc_assert (SYMBOL_REF_BLOCK (symbol));
7039 if (SYMBOL_REF_BLOCK_OFFSET (symbol) >= 0)
7040 return;
7042 /* Work out the symbol's size and alignment. */
7043 if (CONSTANT_POOL_ADDRESS_P (symbol))
7045 desc = SYMBOL_REF_CONSTANT (symbol);
7046 alignment = desc->align;
7047 size = GET_MODE_SIZE (desc->mode);
7049 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
7051 decl = SYMBOL_REF_DECL (symbol);
7052 alignment = DECL_ALIGN (decl);
7053 size = get_constant_size (DECL_INITIAL (decl));
7054 if ((flag_sanitize & SANITIZE_ADDRESS)
7055 && TREE_CODE (DECL_INITIAL (decl)) == STRING_CST
7056 && asan_protect_global (DECL_INITIAL (decl)))
7057 size += asan_red_zone_size (size);
7059 else
7061 struct symtab_node *snode;
7062 decl = SYMBOL_REF_DECL (symbol);
7064 snode = symtab_node::get (decl);
7065 if (snode->alias)
7067 rtx target = DECL_RTL (snode->ultimate_alias_target ()->decl);
7069 place_block_symbol (target);
7070 SYMBOL_REF_BLOCK_OFFSET (symbol) = SYMBOL_REF_BLOCK_OFFSET (target);
7071 return;
7073 alignment = get_variable_align (decl);
7074 size = tree_to_uhwi (DECL_SIZE_UNIT (decl));
7075 if ((flag_sanitize & SANITIZE_ADDRESS)
7076 && asan_protect_global (decl))
7078 size += asan_red_zone_size (size);
7079 alignment = MAX (alignment,
7080 ASAN_RED_ZONE_SIZE * BITS_PER_UNIT);
7084 /* Calculate the object's offset from the start of the block. */
7085 block = SYMBOL_REF_BLOCK (symbol);
7086 mask = alignment / BITS_PER_UNIT - 1;
7087 offset = (block->size + mask) & ~mask;
7088 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
7090 /* Record the block's new alignment and size. */
7091 block->alignment = MAX (block->alignment, alignment);
7092 block->size = offset + size;
7094 vec_safe_push (block->objects, symbol);
7097 /* Return the anchor that should be used to address byte offset OFFSET
7098 from the first object in BLOCK. MODEL is the TLS model used
7099 to access it. */
7102 get_section_anchor (struct object_block *block, HOST_WIDE_INT offset,
7103 enum tls_model model)
7105 char label[100];
7106 unsigned int begin, middle, end;
7107 unsigned HOST_WIDE_INT min_offset, max_offset, range, bias, delta;
7108 rtx anchor;
7110 /* Work out the anchor's offset. Use an offset of 0 for the first
7111 anchor so that we don't pessimize the case where we take the address
7112 of a variable at the beginning of the block. This is particularly
7113 useful when a block has only one variable assigned to it.
7115 We try to place anchors RANGE bytes apart, so there can then be
7116 anchors at +/-RANGE, +/-2 * RANGE, and so on, up to the limits of
7117 a ptr_mode offset. With some target settings, the lowest such
7118 anchor might be out of range for the lowest ptr_mode offset;
7119 likewise the highest anchor for the highest offset. Use anchors
7120 at the extreme ends of the ptr_mode range in such cases.
7122 All arithmetic uses unsigned integers in order to avoid
7123 signed overflow. */
7124 max_offset = (unsigned HOST_WIDE_INT) targetm.max_anchor_offset;
7125 min_offset = (unsigned HOST_WIDE_INT) targetm.min_anchor_offset;
7126 range = max_offset - min_offset + 1;
7127 if (range == 0)
7128 offset = 0;
7129 else
7131 bias = 1 << (GET_MODE_BITSIZE (ptr_mode) - 1);
7132 if (offset < 0)
7134 delta = -(unsigned HOST_WIDE_INT) offset + max_offset;
7135 delta -= delta % range;
7136 if (delta > bias)
7137 delta = bias;
7138 offset = (HOST_WIDE_INT) (-delta);
7140 else
7142 delta = (unsigned HOST_WIDE_INT) offset - min_offset;
7143 delta -= delta % range;
7144 if (delta > bias - 1)
7145 delta = bias - 1;
7146 offset = (HOST_WIDE_INT) delta;
7150 /* Do a binary search to see if there's already an anchor we can use.
7151 Set BEGIN to the new anchor's index if not. */
7152 begin = 0;
7153 end = vec_safe_length (block->anchors);
7154 while (begin != end)
7156 middle = (end + begin) / 2;
7157 anchor = (*block->anchors)[middle];
7158 if (SYMBOL_REF_BLOCK_OFFSET (anchor) > offset)
7159 end = middle;
7160 else if (SYMBOL_REF_BLOCK_OFFSET (anchor) < offset)
7161 begin = middle + 1;
7162 else if (SYMBOL_REF_TLS_MODEL (anchor) > model)
7163 end = middle;
7164 else if (SYMBOL_REF_TLS_MODEL (anchor) < model)
7165 begin = middle + 1;
7166 else
7167 return anchor;
7170 /* Create a new anchor with a unique label. */
7171 ASM_GENERATE_INTERNAL_LABEL (label, "LANCHOR", anchor_labelno++);
7172 anchor = create_block_symbol (ggc_strdup (label), block, offset);
7173 SYMBOL_REF_FLAGS (anchor) |= SYMBOL_FLAG_LOCAL | SYMBOL_FLAG_ANCHOR;
7174 SYMBOL_REF_FLAGS (anchor) |= model << SYMBOL_FLAG_TLS_SHIFT;
7176 /* Insert it at index BEGIN. */
7177 vec_safe_insert (block->anchors, begin, anchor);
7178 return anchor;
7181 /* Output the objects in BLOCK. */
7183 static void
7184 output_object_block (struct object_block *block)
7186 struct constant_descriptor_rtx *desc;
7187 unsigned int i;
7188 HOST_WIDE_INT offset;
7189 tree decl;
7190 rtx symbol;
7192 if (!block->objects)
7193 return;
7195 /* Switch to the section and make sure that the first byte is
7196 suitably aligned. */
7197 switch_to_section (block->sect);
7198 assemble_align (block->alignment);
7200 /* Define the values of all anchors relative to the current section
7201 position. */
7202 FOR_EACH_VEC_SAFE_ELT (block->anchors, i, symbol)
7203 targetm.asm_out.output_anchor (symbol);
7205 /* Output the objects themselves. */
7206 offset = 0;
7207 FOR_EACH_VEC_ELT (*block->objects, i, symbol)
7209 /* Move to the object's offset, padding with zeros if necessary. */
7210 assemble_zeros (SYMBOL_REF_BLOCK_OFFSET (symbol) - offset);
7211 offset = SYMBOL_REF_BLOCK_OFFSET (symbol);
7212 if (CONSTANT_POOL_ADDRESS_P (symbol))
7214 desc = SYMBOL_REF_CONSTANT (symbol);
7215 output_constant_pool_1 (desc, 1);
7216 offset += GET_MODE_SIZE (desc->mode);
7218 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
7220 HOST_WIDE_INT size;
7221 decl = SYMBOL_REF_DECL (symbol);
7222 assemble_constant_contents (DECL_INITIAL (decl), XSTR (symbol, 0),
7223 DECL_ALIGN (decl));
7224 size = get_constant_size (DECL_INITIAL (decl));
7225 offset += size;
7226 if ((flag_sanitize & SANITIZE_ADDRESS)
7227 && TREE_CODE (DECL_INITIAL (decl)) == STRING_CST
7228 && asan_protect_global (DECL_INITIAL (decl)))
7230 size = asan_red_zone_size (size);
7231 assemble_zeros (size);
7232 offset += size;
7235 else
7237 HOST_WIDE_INT size;
7238 decl = SYMBOL_REF_DECL (symbol);
7239 assemble_variable_contents (decl, XSTR (symbol, 0), false);
7240 size = tree_to_uhwi (DECL_SIZE_UNIT (decl));
7241 offset += size;
7242 if ((flag_sanitize & SANITIZE_ADDRESS)
7243 && asan_protect_global (decl))
7245 size = asan_red_zone_size (size);
7246 assemble_zeros (size);
7247 offset += size;
7253 /* A htab_traverse callback used to call output_object_block for
7254 each member of object_block_htab. */
7256 static int
7257 output_object_block_htab (void **slot, void *data ATTRIBUTE_UNUSED)
7259 output_object_block ((struct object_block *) (*slot));
7260 return 1;
7263 /* Output the definitions of all object_blocks. */
7265 void
7266 output_object_blocks (void)
7268 htab_traverse (object_block_htab, output_object_block_htab, NULL);
7271 /* This function provides a possible implementation of the
7272 TARGET_ASM_RECORD_GCC_SWITCHES target hook for ELF targets. When triggered
7273 by -frecord-gcc-switches it creates a new mergeable, string section in the
7274 assembler output file called TARGET_ASM_RECORD_GCC_SWITCHES_SECTION which
7275 contains the switches in ASCII format.
7277 FIXME: This code does not correctly handle double quote characters
7278 that appear inside strings, (it strips them rather than preserving them).
7279 FIXME: ASM_OUTPUT_ASCII, as defined in config/elfos.h will not emit NUL
7280 characters - instead it treats them as sub-string separators. Since
7281 we want to emit NUL strings terminators into the object file we have to use
7282 ASM_OUTPUT_SKIP. */
7285 elf_record_gcc_switches (print_switch_type type, const char * name)
7287 switch (type)
7289 case SWITCH_TYPE_PASSED:
7290 ASM_OUTPUT_ASCII (asm_out_file, name, strlen (name));
7291 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
7292 break;
7294 case SWITCH_TYPE_DESCRIPTIVE:
7295 if (name == NULL)
7297 /* Distinguish between invocations where name is NULL. */
7298 static bool started = false;
7300 if (!started)
7302 section * sec;
7304 sec = get_section (targetm.asm_out.record_gcc_switches_section,
7305 SECTION_DEBUG
7306 | SECTION_MERGE
7307 | SECTION_STRINGS
7308 | (SECTION_ENTSIZE & 1),
7309 NULL);
7310 switch_to_section (sec);
7311 started = true;
7315 default:
7316 break;
7319 /* The return value is currently ignored by the caller, but must be 0.
7320 For -fverbose-asm the return value would be the number of characters
7321 emitted into the assembler file. */
7322 return 0;
7325 /* Emit text to declare externally defined symbols. It is needed to
7326 properly support non-default visibility. */
7327 void
7328 default_elf_asm_output_external (FILE *file ATTRIBUTE_UNUSED,
7329 tree decl,
7330 const char *name ATTRIBUTE_UNUSED)
7332 /* We output the name if and only if TREE_SYMBOL_REFERENCED is
7333 set in order to avoid putting out names that are never really
7334 used. */
7335 if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))
7336 && targetm.binds_local_p (decl))
7337 maybe_assemble_visibility (decl);
7340 /* The default hook for TARGET_ASM_OUTPUT_SOURCE_FILENAME. */
7342 void
7343 default_asm_output_source_filename (FILE *file, const char *name)
7345 #ifdef ASM_OUTPUT_SOURCE_FILENAME
7346 ASM_OUTPUT_SOURCE_FILENAME (file, name);
7347 #else
7348 fprintf (file, "\t.file\t");
7349 output_quoted_string (file, name);
7350 putc ('\n', file);
7351 #endif
7354 /* Output a file name in the form wanted by System V. */
7356 void
7357 output_file_directive (FILE *asm_file, const char *input_name)
7359 int len;
7360 const char *na;
7362 if (input_name == NULL)
7363 input_name = "<stdin>";
7364 else
7365 input_name = remap_debug_filename (input_name);
7367 len = strlen (input_name);
7368 na = input_name + len;
7370 /* NA gets INPUT_NAME sans directory names. */
7371 while (na > input_name)
7373 if (IS_DIR_SEPARATOR (na[-1]))
7374 break;
7375 na--;
7378 targetm.asm_out.output_source_filename (asm_file, na);
7381 /* Create a DEBUG_EXPR_DECL / DEBUG_EXPR pair from RTL expression
7382 EXP. */
7384 make_debug_expr_from_rtl (const_rtx exp)
7386 tree ddecl = make_node (DEBUG_EXPR_DECL), type;
7387 enum machine_mode mode = GET_MODE (exp);
7388 rtx dval;
7390 DECL_ARTIFICIAL (ddecl) = 1;
7391 if (REG_P (exp) && REG_EXPR (exp))
7392 type = TREE_TYPE (REG_EXPR (exp));
7393 else if (MEM_P (exp) && MEM_EXPR (exp))
7394 type = TREE_TYPE (MEM_EXPR (exp));
7395 else
7396 type = NULL_TREE;
7397 if (type && TYPE_MODE (type) == mode)
7398 TREE_TYPE (ddecl) = type;
7399 else
7400 TREE_TYPE (ddecl) = lang_hooks.types.type_for_mode (mode, 1);
7401 DECL_MODE (ddecl) = mode;
7402 dval = gen_rtx_DEBUG_EXPR (mode);
7403 DEBUG_EXPR_TREE_DECL (dval) = ddecl;
7404 SET_DECL_RTL (ddecl, dval);
7405 return dval;
7408 #ifdef ELF_ASCII_ESCAPES
7409 /* Default ASM_OUTPUT_LIMITED_STRING for ELF targets. */
7411 void
7412 default_elf_asm_output_limited_string (FILE *f, const char *s)
7414 int escape;
7415 unsigned char c;
7417 fputs (STRING_ASM_OP, f);
7418 putc ('"', f);
7419 while (*s != '\0')
7421 c = *s;
7422 escape = ELF_ASCII_ESCAPES[c];
7423 switch (escape)
7425 case 0:
7426 putc (c, f);
7427 break;
7428 case 1:
7429 /* TODO: Print in hex with fast function, important for -flto. */
7430 fprintf (f, "\\%03o", c);
7431 break;
7432 default:
7433 putc ('\\', f);
7434 putc (escape, f);
7435 break;
7437 s++;
7439 putc ('\"', f);
7440 putc ('\n', f);
7443 /* Default ASM_OUTPUT_ASCII for ELF targets. */
7445 void
7446 default_elf_asm_output_ascii (FILE *f, const char *s, unsigned int len)
7448 const char *limit = s + len;
7449 const char *last_null = NULL;
7450 unsigned bytes_in_chunk = 0;
7451 unsigned char c;
7452 int escape;
7454 for (; s < limit; s++)
7456 const char *p;
7458 if (bytes_in_chunk >= 60)
7460 putc ('\"', f);
7461 putc ('\n', f);
7462 bytes_in_chunk = 0;
7465 if (s > last_null)
7467 for (p = s; p < limit && *p != '\0'; p++)
7468 continue;
7469 last_null = p;
7471 else
7472 p = last_null;
7474 if (p < limit && (p - s) <= (long) ELF_STRING_LIMIT)
7476 if (bytes_in_chunk > 0)
7478 putc ('\"', f);
7479 putc ('\n', f);
7480 bytes_in_chunk = 0;
7483 default_elf_asm_output_limited_string (f, s);
7484 s = p;
7486 else
7488 if (bytes_in_chunk == 0)
7489 fputs (ASCII_DATA_ASM_OP "\"", f);
7491 c = *s;
7492 escape = ELF_ASCII_ESCAPES[c];
7493 switch (escape)
7495 case 0:
7496 putc (c, f);
7497 bytes_in_chunk++;
7498 break;
7499 case 1:
7500 /* TODO: Print in hex with fast function, important for -flto. */
7501 fprintf (f, "\\%03o", c);
7502 bytes_in_chunk += 4;
7503 break;
7504 default:
7505 putc ('\\', f);
7506 putc (escape, f);
7507 bytes_in_chunk += 2;
7508 break;
7514 if (bytes_in_chunk > 0)
7516 putc ('\"', f);
7517 putc ('\n', f);
7520 #endif
7522 static GTY(()) section *elf_init_array_section;
7523 static GTY(()) section *elf_fini_array_section;
7525 static section *
7526 get_elf_initfini_array_priority_section (int priority,
7527 bool constructor_p)
7529 section *sec;
7530 if (priority != DEFAULT_INIT_PRIORITY)
7532 char buf[18];
7533 sprintf (buf, "%s.%.5u",
7534 constructor_p ? ".init_array" : ".fini_array",
7535 priority);
7536 sec = get_section (buf, SECTION_WRITE | SECTION_NOTYPE, NULL_TREE);
7538 else
7540 if (constructor_p)
7542 if (elf_init_array_section == NULL)
7543 elf_init_array_section
7544 = get_section (".init_array",
7545 SECTION_WRITE | SECTION_NOTYPE, NULL_TREE);
7546 sec = elf_init_array_section;
7548 else
7550 if (elf_fini_array_section == NULL)
7551 elf_fini_array_section
7552 = get_section (".fini_array",
7553 SECTION_WRITE | SECTION_NOTYPE, NULL_TREE);
7554 sec = elf_fini_array_section;
7557 return sec;
7560 /* Use .init_array section for constructors. */
7562 void
7563 default_elf_init_array_asm_out_constructor (rtx symbol, int priority)
7565 section *sec = get_elf_initfini_array_priority_section (priority,
7566 true);
7567 assemble_addr_to_section (symbol, sec);
7570 /* Use .fini_array section for destructors. */
7572 void
7573 default_elf_fini_array_asm_out_destructor (rtx symbol, int priority)
7575 section *sec = get_elf_initfini_array_priority_section (priority,
7576 false);
7577 assemble_addr_to_section (symbol, sec);
7580 /* Default TARGET_ASM_OUTPUT_IDENT hook.
7582 This is a bit of a cheat. The real default is a no-op, but this
7583 hook is the default for all targets with a .ident directive. */
7585 void
7586 default_asm_output_ident_directive (const char *ident_str)
7588 const char *ident_asm_op = "\t.ident\t";
7590 /* If we are still in the front end, do not write out the string
7591 to asm_out_file. Instead, add a fake top-level asm statement.
7592 This allows the front ends to use this hook without actually
7593 writing to asm_out_file, to handle #ident or Pragma Ident. */
7594 if (cgraph_state == CGRAPH_STATE_PARSING)
7596 char *buf = ACONCAT ((ident_asm_op, "\"", ident_str, "\"\n", NULL));
7597 add_asm_node (build_string (strlen (buf), buf));
7599 else
7600 fprintf (asm_out_file, "%s\"%s\"\n", ident_asm_op, ident_str);
7603 #include "gt-varasm.h"