2008-05-20 Kai Tietz <kai.tietz@onevision.com>
[official-gcc.git] / gcc / varasm.c
blobd9468c4997dcd068ba90e04e475c1ac9d1260dc5
1 /* Output variables, constants and external declarations, for GNU compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
23 /* This file handles generation of all the assembler code
24 *except* the instructions of a function.
25 This includes declarations of variables and their initial values.
27 We also output the assembler code for constants stored in memory
28 and are responsible for combining constants with the same value. */
30 #include "config.h"
31 #include "system.h"
32 #include "coretypes.h"
33 #include "tm.h"
34 #include "rtl.h"
35 #include "tree.h"
36 #include "flags.h"
37 #include "function.h"
38 #include "expr.h"
39 #include "hard-reg-set.h"
40 #include "regs.h"
41 #include "real.h"
42 #include "output.h"
43 #include "toplev.h"
44 #include "hashtab.h"
45 #include "c-pragma.h"
46 #include "ggc.h"
47 #include "langhooks.h"
48 #include "tm_p.h"
49 #include "debug.h"
50 #include "target.h"
51 #include "targhooks.h"
52 #include "tree-mudflap.h"
53 #include "cgraph.h"
54 #include "cfglayout.h"
55 #include "basic-block.h"
56 #include "tree-iterator.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 static const char *strip_reg_name (const char *);
104 static int contains_pointers_p (tree);
105 #ifdef ASM_OUTPUT_EXTERNAL
106 static bool incorporeal_function_p (tree);
107 #endif
108 static void decode_addr_const (tree, struct addr_const *);
109 static hashval_t const_desc_hash (const void *);
110 static int const_desc_eq (const void *, const void *);
111 static hashval_t const_hash_1 (const tree);
112 static int compare_constant (const tree, const tree);
113 static tree copy_constant (tree);
114 static void output_constant_def_contents (rtx);
115 static void output_addressed_constants (tree);
116 static unsigned HOST_WIDE_INT array_size_for_constructor (tree);
117 static unsigned min_align (unsigned, unsigned);
118 static void output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int);
119 static void globalize_decl (tree);
120 #ifdef BSS_SECTION_ASM_OP
121 #ifdef ASM_OUTPUT_BSS
122 static void asm_output_bss (FILE *, tree, const char *,
123 unsigned HOST_WIDE_INT, unsigned HOST_WIDE_INT);
124 #endif
125 #ifdef ASM_OUTPUT_ALIGNED_BSS
126 static void asm_output_aligned_bss (FILE *, tree, const char *,
127 unsigned HOST_WIDE_INT, int)
128 ATTRIBUTE_UNUSED;
129 #endif
130 #endif /* BSS_SECTION_ASM_OP */
131 static void mark_weak (tree);
132 static void output_constant_pool (const char *, tree);
134 /* Well-known sections, each one associated with some sort of *_ASM_OP. */
135 section *text_section;
136 section *data_section;
137 section *readonly_data_section;
138 section *sdata_section;
139 section *ctors_section;
140 section *dtors_section;
141 section *bss_section;
142 section *sbss_section;
144 /* Various forms of common section. All are guaranteed to be nonnull. */
145 section *tls_comm_section;
146 section *comm_section;
147 section *lcomm_section;
149 /* A SECTION_NOSWITCH section used for declaring global BSS variables.
150 May be null. */
151 section *bss_noswitch_section;
153 /* The section that holds the main exception table, when known. The section
154 is set either by the target's init_sections hook or by the first call to
155 switch_to_exception_section. */
156 section *exception_section;
158 /* The section that holds the DWARF2 frame unwind information, when known.
159 The section is set either by the target's init_sections hook or by the
160 first call to switch_to_eh_frame_section. */
161 section *eh_frame_section;
163 /* asm_out_file's current section. This is NULL if no section has yet
164 been selected or if we lose track of what the current section is. */
165 section *in_section;
167 /* True if code for the current function is currently being directed
168 at the cold section. */
169 bool in_cold_section_p;
171 /* A linked list of all the unnamed sections. */
172 static GTY(()) section *unnamed_sections;
174 /* Return a nonzero value if DECL has a section attribute. */
175 #ifndef IN_NAMED_SECTION
176 #define IN_NAMED_SECTION(DECL) \
177 ((TREE_CODE (DECL) == FUNCTION_DECL || TREE_CODE (DECL) == VAR_DECL) \
178 && DECL_SECTION_NAME (DECL) != NULL_TREE)
179 #endif
181 /* Hash table of named sections. */
182 static GTY((param_is (section))) htab_t section_htab;
184 /* A table of object_blocks, indexed by section. */
185 static GTY((param_is (struct object_block))) htab_t object_block_htab;
187 /* The next number to use for internal anchor labels. */
188 static GTY(()) int anchor_labelno;
190 /* A pool of constants that can be shared between functions. */
191 static GTY(()) struct rtx_constant_pool *shared_constant_pool;
193 /* TLS emulation. */
195 static GTY ((if_marked ("tree_map_marked_p"), param_is (struct tree_map)))
196 htab_t emutls_htab;
197 static GTY (()) tree emutls_object_type;
198 /* Emulated TLS objects have the TLS model TLS_MODEL_EMULATED. This
199 macro can be used on them to distinguish the control variable from
200 the initialization template. */
201 #define DECL_EMUTLS_VAR_P(D) (TREE_TYPE (D) == emutls_object_type)
203 #if !defined (NO_DOT_IN_LABEL)
204 # define EMUTLS_SEPARATOR "."
205 #elif !defined (NO_DOLLAR_IN_LABEL)
206 # define EMUTLS_SEPARATOR "$"
207 #else
208 # define EMUTLS_SEPARATOR "_"
209 #endif
211 /* Create an IDENTIFIER_NODE by prefixing PREFIX to the
212 IDENTIFIER_NODE NAME's name. */
214 static tree
215 prefix_name (const char *prefix, tree name)
217 unsigned plen = strlen (prefix);
218 unsigned nlen = strlen (IDENTIFIER_POINTER (name));
219 char *toname = alloca (plen + nlen + 1);
221 memcpy (toname, prefix, plen);
222 memcpy (toname + plen, IDENTIFIER_POINTER (name), nlen + 1);
224 return get_identifier (toname);
227 /* Create an identifier for the struct __emutls_object, given an identifier
228 of the DECL_ASSEMBLY_NAME of the original object. */
230 static tree
231 get_emutls_object_name (tree name)
233 const char *prefix = (targetm.emutls.var_prefix
234 ? targetm.emutls.var_prefix
235 : "__emutls_v" EMUTLS_SEPARATOR);
236 return prefix_name (prefix, name);
239 tree
240 default_emutls_var_fields (tree type, tree *name ATTRIBUTE_UNUSED)
242 tree word_type_node, field, next_field;
244 field = build_decl (FIELD_DECL, get_identifier ("__templ"), ptr_type_node);
245 DECL_CONTEXT (field) = type;
246 next_field = field;
248 field = build_decl (FIELD_DECL, get_identifier ("__offset"),
249 ptr_type_node);
250 DECL_CONTEXT (field) = type;
251 TREE_CHAIN (field) = next_field;
252 next_field = field;
254 word_type_node = lang_hooks.types.type_for_mode (word_mode, 1);
255 field = build_decl (FIELD_DECL, get_identifier ("__align"),
256 word_type_node);
257 DECL_CONTEXT (field) = type;
258 TREE_CHAIN (field) = next_field;
259 next_field = field;
261 field = build_decl (FIELD_DECL, get_identifier ("__size"), word_type_node);
262 DECL_CONTEXT (field) = type;
263 TREE_CHAIN (field) = next_field;
265 return field;
268 /* Create the structure for struct __emutls_object. This should match the
269 structure at the top of emutls.c, modulo the union there. */
271 static tree
272 get_emutls_object_type (void)
274 tree type, type_name, field;
276 type = emutls_object_type;
277 if (type)
278 return type;
280 emutls_object_type = type = lang_hooks.types.make_type (RECORD_TYPE);
281 type_name = NULL;
282 field = targetm.emutls.var_fields (type, &type_name);
283 if (!type_name)
284 type_name = get_identifier ("__emutls_object");
285 type_name = build_decl (TYPE_DECL, type_name, type);
286 TYPE_NAME (type) = type_name;
287 TYPE_FIELDS (type) = field;
288 layout_type (type);
290 return type;
293 /* Create a read-only variable like DECL, with the same DECL_INITIAL.
294 This will be used for initializing the emulated tls data area. */
296 static tree
297 get_emutls_init_templ_addr (tree decl)
299 tree name, to;
301 if (targetm.emutls.register_common && !DECL_INITIAL (decl)
302 && !DECL_SECTION_NAME (decl))
303 return null_pointer_node;
305 name = DECL_ASSEMBLER_NAME (decl);
306 if (!targetm.emutls.tmpl_prefix || targetm.emutls.tmpl_prefix[0])
308 const char *prefix = (targetm.emutls.tmpl_prefix
309 ? targetm.emutls.tmpl_prefix
310 : "__emutls_t" EMUTLS_SEPARATOR);
311 name = prefix_name (prefix, name);
314 to = build_decl (VAR_DECL, name, TREE_TYPE (decl));
315 SET_DECL_ASSEMBLER_NAME (to, DECL_NAME (to));
316 DECL_TLS_MODEL (to) = TLS_MODEL_EMULATED;
317 DECL_ARTIFICIAL (to) = 1;
318 TREE_USED (to) = TREE_USED (decl);
319 TREE_READONLY (to) = 1;
320 DECL_IGNORED_P (to) = 1;
321 DECL_CONTEXT (to) = DECL_CONTEXT (decl);
322 DECL_SECTION_NAME (to) = DECL_SECTION_NAME (decl);
324 DECL_WEAK (to) = DECL_WEAK (decl);
325 if (DECL_ONE_ONLY (decl))
327 make_decl_one_only (to);
328 TREE_STATIC (to) = TREE_STATIC (decl);
329 TREE_PUBLIC (to) = TREE_PUBLIC (decl);
330 DECL_VISIBILITY (to) = DECL_VISIBILITY (decl);
332 else
333 TREE_STATIC (to) = 1;
335 DECL_INITIAL (to) = DECL_INITIAL (decl);
336 DECL_INITIAL (decl) = NULL;
338 varpool_finalize_decl (to);
339 return build_fold_addr_expr (to);
342 /* When emulating tls, we use a control structure for use by the runtime.
343 Create and return this structure. */
345 tree
346 emutls_decl (tree decl)
348 tree name, to;
349 struct tree_map *h, in;
350 void **loc;
352 if (targetm.have_tls || decl == NULL || decl == error_mark_node
353 || TREE_CODE (decl) != VAR_DECL || ! DECL_THREAD_LOCAL_P (decl))
354 return decl;
356 /* Look up the object in the hash; return the control structure if
357 it has already been created. */
358 if (! emutls_htab)
359 emutls_htab = htab_create_ggc (512, tree_map_hash, tree_map_eq, 0);
361 name = DECL_ASSEMBLER_NAME (decl);
363 /* Note that we use the hash of the decl's name, rather than a hash
364 of the decl's pointer. In emutls_finish we iterate through the
365 hash table, and we want this traversal to be predictable. */
366 in.hash = htab_hash_string (IDENTIFIER_POINTER (name));
367 in.base.from = decl;
368 loc = htab_find_slot_with_hash (emutls_htab, &in, in.hash, INSERT);
369 h = *loc;
370 if (h != NULL)
371 to = h->to;
372 else
374 to = build_decl (VAR_DECL, get_emutls_object_name (name),
375 get_emutls_object_type ());
377 h = ggc_alloc (sizeof (struct tree_map));
378 h->hash = in.hash;
379 h->base.from = decl;
380 h->to = to;
381 *(struct tree_map **) loc = h;
383 DECL_TLS_MODEL (to) = TLS_MODEL_EMULATED;
384 DECL_ARTIFICIAL (to) = 1;
385 DECL_IGNORED_P (to) = 1;
386 TREE_READONLY (to) = 0;
387 SET_DECL_ASSEMBLER_NAME (to, DECL_NAME (to));
388 if (DECL_ONE_ONLY (decl))
389 make_decl_one_only (to);
390 DECL_CONTEXT (to) = DECL_CONTEXT (decl);
391 if (targetm.emutls.var_align_fixed)
392 /* If we're not allowed to change the proxy object's
393 alignment, pretend it's been set by the user. */
394 DECL_USER_ALIGN (to) = 1;
397 /* Note that these fields may need to be updated from time to time from
398 the original decl. Consider:
399 extern __thread int i;
400 int foo() { return i; }
401 __thread int i = 1;
402 in which I goes from external to locally defined and initialized. */
404 TREE_STATIC (to) = TREE_STATIC (decl);
405 TREE_USED (to) = TREE_USED (decl);
406 TREE_PUBLIC (to) = TREE_PUBLIC (decl);
407 DECL_EXTERNAL (to) = DECL_EXTERNAL (decl);
408 DECL_COMMON (to) = DECL_COMMON (decl);
409 DECL_WEAK (to) = DECL_WEAK (decl);
410 DECL_VISIBILITY (to) = DECL_VISIBILITY (decl);
412 return to;
415 static int
416 emutls_common_1 (void **loc, void *xstmts)
418 struct tree_map *h = *(struct tree_map **) loc;
419 tree args, x, *pstmts = (tree *) xstmts;
420 tree word_type_node;
422 if (! DECL_COMMON (h->base.from)
423 || (DECL_INITIAL (h->base.from)
424 && DECL_INITIAL (h->base.from) != error_mark_node))
425 return 1;
427 word_type_node = lang_hooks.types.type_for_mode (word_mode, 1);
429 /* The idea was to call get_emutls_init_templ_addr here, but if we
430 do this and there is an initializer, -fanchor_section loses,
431 because it would be too late to ensure the template is
432 output. */
433 x = null_pointer_node;
434 args = tree_cons (NULL, x, NULL);
435 x = build_int_cst (word_type_node, DECL_ALIGN_UNIT (h->base.from));
436 args = tree_cons (NULL, x, args);
437 x = fold_convert (word_type_node, DECL_SIZE_UNIT (h->base.from));
438 args = tree_cons (NULL, x, args);
439 x = build_fold_addr_expr (h->to);
440 args = tree_cons (NULL, x, args);
442 x = built_in_decls[BUILT_IN_EMUTLS_REGISTER_COMMON];
443 x = build_function_call_expr (x, args);
445 append_to_statement_list (x, pstmts);
446 return 1;
449 void
450 emutls_finish (void)
452 if (!targetm.emutls.register_common)
454 tree body = NULL_TREE;
456 if (emutls_htab == NULL)
457 return;
459 htab_traverse_noresize (emutls_htab, emutls_common_1, &body);
460 if (body == NULL_TREE)
461 return;
463 cgraph_build_static_cdtor ('I', body, DEFAULT_INIT_PRIORITY);
467 /* Helper routines for maintaining section_htab. */
469 static int
470 section_entry_eq (const void *p1, const void *p2)
472 const section *old = p1;
473 const char *new = p2;
475 return strcmp (old->named.name, new) == 0;
478 static hashval_t
479 section_entry_hash (const void *p)
481 const section *old = p;
482 return htab_hash_string (old->named.name);
485 /* Return a hash value for section SECT. */
487 static hashval_t
488 hash_section (section *sect)
490 if (sect->common.flags & SECTION_NAMED)
491 return htab_hash_string (sect->named.name);
492 return sect->common.flags;
495 /* Helper routines for maintaining object_block_htab. */
497 static int
498 object_block_entry_eq (const void *p1, const void *p2)
500 const struct object_block *old = p1;
501 const section *new = p2;
503 return old->sect == new;
506 static hashval_t
507 object_block_entry_hash (const void *p)
509 const struct object_block *old = p;
510 return hash_section (old->sect);
513 /* Return a new unnamed section with the given fields. */
515 section *
516 get_unnamed_section (unsigned int flags, void (*callback) (const void *),
517 const void *data)
519 section *sect;
521 sect = ggc_alloc (sizeof (struct unnamed_section));
522 sect->unnamed.common.flags = flags | SECTION_UNNAMED;
523 sect->unnamed.callback = callback;
524 sect->unnamed.data = data;
525 sect->unnamed.next = unnamed_sections;
527 unnamed_sections = sect;
528 return sect;
531 /* Return a SECTION_NOSWITCH section with the given fields. */
533 static section *
534 get_noswitch_section (unsigned int flags, noswitch_section_callback callback)
536 section *sect;
538 sect = ggc_alloc (sizeof (struct unnamed_section));
539 sect->noswitch.common.flags = flags | SECTION_NOSWITCH;
540 sect->noswitch.callback = callback;
542 return sect;
545 /* Return the named section structure associated with NAME. Create
546 a new section with the given fields if no such structure exists. */
548 section *
549 get_section (const char *name, unsigned int flags, tree decl)
551 section *sect, **slot;
553 slot = (section **)
554 htab_find_slot_with_hash (section_htab, name,
555 htab_hash_string (name), INSERT);
556 flags |= SECTION_NAMED;
557 if (*slot == NULL)
559 sect = ggc_alloc (sizeof (struct named_section));
560 sect->named.common.flags = flags;
561 sect->named.name = ggc_strdup (name);
562 sect->named.decl = decl;
563 *slot = sect;
565 else
567 sect = *slot;
568 if ((sect->common.flags & ~SECTION_DECLARED) != flags
569 && ((sect->common.flags | flags) & SECTION_OVERRIDE) == 0)
571 /* Sanity check user variables for flag changes. */
572 if (decl == 0)
573 decl = sect->named.decl;
574 gcc_assert (decl);
575 error ("%+D causes a section type conflict", decl);
578 return sect;
581 /* Return true if the current compilation mode benefits from having
582 objects grouped into blocks. */
584 static bool
585 use_object_blocks_p (void)
587 return flag_section_anchors;
590 /* Return the object_block structure for section SECT. Create a new
591 structure if we haven't created one already. Return null if SECT
592 itself is null. */
594 static struct object_block *
595 get_block_for_section (section *sect)
597 struct object_block *block;
598 void **slot;
600 if (sect == NULL)
601 return NULL;
603 slot = htab_find_slot_with_hash (object_block_htab, sect,
604 hash_section (sect), INSERT);
605 block = (struct object_block *) *slot;
606 if (block == NULL)
608 block = (struct object_block *)
609 ggc_alloc_cleared (sizeof (struct object_block));
610 block->sect = sect;
611 *slot = block;
613 return block;
616 /* Create a symbol with label LABEL and place it at byte offset
617 OFFSET in BLOCK. OFFSET can be negative if the symbol's offset
618 is not yet known. LABEL must be a garbage-collected string. */
620 static rtx
621 create_block_symbol (const char *label, struct object_block *block,
622 HOST_WIDE_INT offset)
624 rtx symbol;
625 unsigned int size;
627 /* Create the extended SYMBOL_REF. */
628 size = RTX_HDR_SIZE + sizeof (struct block_symbol);
629 symbol = ggc_alloc_zone (size, &rtl_zone);
631 /* Initialize the normal SYMBOL_REF fields. */
632 memset (symbol, 0, size);
633 PUT_CODE (symbol, SYMBOL_REF);
634 PUT_MODE (symbol, Pmode);
635 XSTR (symbol, 0) = label;
636 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_HAS_BLOCK_INFO;
638 /* Initialize the block_symbol stuff. */
639 SYMBOL_REF_BLOCK (symbol) = block;
640 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
642 return symbol;
645 static void
646 initialize_cold_section_name (void)
648 const char *stripped_name;
649 char *name, *buffer;
650 tree dsn;
652 gcc_assert (cfun && current_function_decl);
653 if (crtl->subsections.unlikely_text_section_name)
654 return;
656 dsn = DECL_SECTION_NAME (current_function_decl);
657 if (flag_function_sections && dsn)
659 name = alloca (TREE_STRING_LENGTH (dsn) + 1);
660 memcpy (name, TREE_STRING_POINTER (dsn), TREE_STRING_LENGTH (dsn) + 1);
662 stripped_name = targetm.strip_name_encoding (name);
664 buffer = ACONCAT ((stripped_name, "_unlikely", NULL));
665 crtl->subsections.unlikely_text_section_name = ggc_strdup (buffer);
667 else
668 crtl->subsections.unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
671 /* Tell assembler to switch to unlikely-to-be-executed text section. */
673 section *
674 unlikely_text_section (void)
676 if (cfun)
678 if (!crtl->subsections.unlikely_text_section_name)
679 initialize_cold_section_name ();
681 return get_named_section (NULL, crtl->subsections.unlikely_text_section_name, 0);
683 else
684 return get_named_section (NULL, UNLIKELY_EXECUTED_TEXT_SECTION_NAME, 0);
687 /* When called within a function context, return true if the function
688 has been assigned a cold text section and if SECT is that section.
689 When called outside a function context, return true if SECT is the
690 default cold section. */
692 bool
693 unlikely_text_section_p (section *sect)
695 const char *name;
697 if (cfun)
698 name = crtl->subsections.unlikely_text_section_name;
699 else
700 name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
702 return (name
703 && sect
704 && SECTION_STYLE (sect) == SECTION_NAMED
705 && strcmp (name, sect->named.name) == 0);
708 /* Return a section with a particular name and with whatever SECTION_*
709 flags section_type_flags deems appropriate. The name of the section
710 is taken from NAME if nonnull, otherwise it is taken from DECL's
711 DECL_SECTION_NAME. DECL is the decl associated with the section
712 (see the section comment for details) and RELOC is as for
713 section_type_flags. */
715 section *
716 get_named_section (tree decl, const char *name, int reloc)
718 unsigned int flags;
720 gcc_assert (!decl || DECL_P (decl));
721 if (name == NULL)
722 name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
724 flags = targetm.section_type_flags (decl, name, reloc);
726 return get_section (name, flags, decl);
729 /* If required, set DECL_SECTION_NAME to a unique name. */
731 void
732 resolve_unique_section (tree decl, int reloc ATTRIBUTE_UNUSED,
733 int flag_function_or_data_sections)
735 if (DECL_SECTION_NAME (decl) == NULL_TREE
736 && targetm.have_named_sections
737 && (flag_function_or_data_sections
738 || DECL_ONE_ONLY (decl)))
739 targetm.asm_out.unique_section (decl, reloc);
742 #ifdef BSS_SECTION_ASM_OP
744 #ifdef ASM_OUTPUT_BSS
746 /* Utility function for ASM_OUTPUT_BSS for targets to use if
747 they don't support alignments in .bss.
748 ??? It is believed that this function will work in most cases so such
749 support is localized here. */
751 static void
752 asm_output_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
753 const char *name,
754 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
755 unsigned HOST_WIDE_INT rounded)
757 gcc_assert (strcmp (XSTR (XEXP (DECL_RTL (decl), 0), 0), name) == 0);
758 targetm.asm_out.globalize_decl_name (file, decl);
759 switch_to_section (bss_section);
760 #ifdef ASM_DECLARE_OBJECT_NAME
761 last_assemble_variable_decl = decl;
762 ASM_DECLARE_OBJECT_NAME (file, name, decl);
763 #else
764 /* Standard thing is just output label for the object. */
765 ASM_OUTPUT_LABEL (file, name);
766 #endif /* ASM_DECLARE_OBJECT_NAME */
767 ASM_OUTPUT_SKIP (file, rounded ? rounded : 1);
770 #endif
772 #ifdef ASM_OUTPUT_ALIGNED_BSS
774 /* Utility function for targets to use in implementing
775 ASM_OUTPUT_ALIGNED_BSS.
776 ??? It is believed that this function will work in most cases so such
777 support is localized here. */
779 static void
780 asm_output_aligned_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
781 const char *name, unsigned HOST_WIDE_INT size,
782 int align)
784 switch_to_section (bss_section);
785 ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
786 #ifdef ASM_DECLARE_OBJECT_NAME
787 last_assemble_variable_decl = decl;
788 ASM_DECLARE_OBJECT_NAME (file, name, decl);
789 #else
790 /* Standard thing is just output label for the object. */
791 ASM_OUTPUT_LABEL (file, name);
792 #endif /* ASM_DECLARE_OBJECT_NAME */
793 ASM_OUTPUT_SKIP (file, size ? size : 1);
796 #endif
798 #endif /* BSS_SECTION_ASM_OP */
800 #ifndef USE_SELECT_SECTION_FOR_FUNCTIONS
801 /* Return the hot section for function DECL. Return text_section for
802 null DECLs. */
804 static section *
805 hot_function_section (tree decl)
807 if (decl != NULL_TREE
808 && DECL_SECTION_NAME (decl) != NULL_TREE
809 && targetm.have_named_sections)
810 return get_named_section (decl, NULL, 0);
811 else
812 return text_section;
814 #endif
816 /* Return the section for function DECL.
818 If DECL is NULL_TREE, return the text section. We can be passed
819 NULL_TREE under some circumstances by dbxout.c at least. */
821 section *
822 function_section (tree decl)
824 int reloc = 0;
826 if (first_function_block_is_cold)
827 reloc = 1;
829 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
830 if (decl != NULL_TREE
831 && DECL_SECTION_NAME (decl) != NULL_TREE)
832 return reloc ? unlikely_text_section ()
833 : get_named_section (decl, NULL, 0);
834 else
835 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
836 #else
837 return reloc ? unlikely_text_section () : hot_function_section (decl);
838 #endif
841 section *
842 current_function_section (void)
844 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
845 if (current_function_decl != NULL_TREE
846 && DECL_SECTION_NAME (current_function_decl) != NULL_TREE)
847 return in_cold_section_p ? unlikely_text_section ()
848 : get_named_section (current_function_decl,
849 NULL, 0);
850 else
851 return targetm.asm_out.select_section (current_function_decl,
852 in_cold_section_p,
853 DECL_ALIGN (current_function_decl));
854 #else
855 return (in_cold_section_p
856 ? unlikely_text_section ()
857 : hot_function_section (current_function_decl));
858 #endif
861 /* Return the read-only data section associated with function DECL. */
863 section *
864 default_function_rodata_section (tree decl)
866 if (decl != NULL_TREE && DECL_SECTION_NAME (decl))
868 const char *name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
870 if (DECL_ONE_ONLY (decl) && HAVE_COMDAT_GROUP)
872 size_t len = strlen (name) + 3;
873 char* rname = alloca (len);
875 strcpy (rname, ".rodata");
876 strcat (rname, name + 5);
877 return get_section (rname, SECTION_LINKONCE, decl);
879 /* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo. */
880 else if (DECL_ONE_ONLY (decl)
881 && strncmp (name, ".gnu.linkonce.t.", 16) == 0)
883 size_t len = strlen (name) + 1;
884 char *rname = alloca (len);
886 memcpy (rname, name, len);
887 rname[14] = 'r';
888 return get_section (rname, SECTION_LINKONCE, decl);
890 /* For .text.foo we want to use .rodata.foo. */
891 else if (flag_function_sections && flag_data_sections
892 && strncmp (name, ".text.", 6) == 0)
894 size_t len = strlen (name) + 1;
895 char *rname = alloca (len + 2);
897 memcpy (rname, ".rodata", 7);
898 memcpy (rname + 7, name + 5, len - 5);
899 return get_section (rname, 0, decl);
903 return readonly_data_section;
906 /* Return the read-only data section associated with function DECL
907 for targets where that section should be always the single
908 readonly data section. */
910 section *
911 default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED)
913 return readonly_data_section;
916 /* Return the section to use for string merging. */
918 static section *
919 mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
920 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
921 unsigned int flags ATTRIBUTE_UNUSED)
923 HOST_WIDE_INT len;
925 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
926 && TREE_CODE (decl) == STRING_CST
927 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
928 && align <= 256
929 && (len = int_size_in_bytes (TREE_TYPE (decl))) > 0
930 && TREE_STRING_LENGTH (decl) >= len)
932 enum machine_mode mode;
933 unsigned int modesize;
934 const char *str;
935 HOST_WIDE_INT i;
936 int j, unit;
937 char name[30];
939 mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl)));
940 modesize = GET_MODE_BITSIZE (mode);
941 if (modesize >= 8 && modesize <= 256
942 && (modesize & (modesize - 1)) == 0)
944 if (align < modesize)
945 align = modesize;
947 str = TREE_STRING_POINTER (decl);
948 unit = GET_MODE_SIZE (mode);
950 /* Check for embedded NUL characters. */
951 for (i = 0; i < len; i += unit)
953 for (j = 0; j < unit; j++)
954 if (str[i + j] != '\0')
955 break;
956 if (j == unit)
957 break;
959 if (i == len - unit)
961 sprintf (name, ".rodata.str%d.%d", modesize / 8,
962 (int) (align / 8));
963 flags |= (modesize / 8) | SECTION_MERGE | SECTION_STRINGS;
964 return get_section (name, flags, NULL);
969 return readonly_data_section;
972 /* Return the section to use for constant merging. */
974 section *
975 mergeable_constant_section (enum machine_mode mode ATTRIBUTE_UNUSED,
976 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
977 unsigned int flags ATTRIBUTE_UNUSED)
979 unsigned int modesize = GET_MODE_BITSIZE (mode);
981 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
982 && mode != VOIDmode
983 && mode != BLKmode
984 && modesize <= align
985 && align >= 8
986 && align <= 256
987 && (align & (align - 1)) == 0)
989 char name[24];
991 sprintf (name, ".rodata.cst%d", (int) (align / 8));
992 flags |= (align / 8) | SECTION_MERGE;
993 return get_section (name, flags, NULL);
995 return readonly_data_section;
998 /* Given NAME, a putative register name, discard any customary prefixes. */
1000 static const char *
1001 strip_reg_name (const char *name)
1003 #ifdef REGISTER_PREFIX
1004 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
1005 name += strlen (REGISTER_PREFIX);
1006 #endif
1007 if (name[0] == '%' || name[0] == '#')
1008 name++;
1009 return name;
1012 /* The user has asked for a DECL to have a particular name. Set (or
1013 change) it in such a way that we don't prefix an underscore to
1014 it. */
1015 void
1016 set_user_assembler_name (tree decl, const char *name)
1018 char *starred = alloca (strlen (name) + 2);
1019 starred[0] = '*';
1020 strcpy (starred + 1, name);
1021 change_decl_assembler_name (decl, get_identifier (starred));
1022 SET_DECL_RTL (decl, NULL_RTX);
1025 /* Decode an `asm' spec for a declaration as a register name.
1026 Return the register number, or -1 if nothing specified,
1027 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
1028 or -3 if ASMSPEC is `cc' and is not recognized,
1029 or -4 if ASMSPEC is `memory' and is not recognized.
1030 Accept an exact spelling or a decimal number.
1031 Prefixes such as % are optional. */
1034 decode_reg_name (const char *asmspec)
1036 if (asmspec != 0)
1038 int i;
1040 /* Get rid of confusing prefixes. */
1041 asmspec = strip_reg_name (asmspec);
1043 /* Allow a decimal number as a "register name". */
1044 for (i = strlen (asmspec) - 1; i >= 0; i--)
1045 if (! ISDIGIT (asmspec[i]))
1046 break;
1047 if (asmspec[0] != 0 && i < 0)
1049 i = atoi (asmspec);
1050 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
1051 return i;
1052 else
1053 return -2;
1056 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1057 if (reg_names[i][0]
1058 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
1059 return i;
1061 #ifdef ADDITIONAL_REGISTER_NAMES
1063 static const struct { const char *const name; const int number; } table[]
1064 = ADDITIONAL_REGISTER_NAMES;
1066 for (i = 0; i < (int) ARRAY_SIZE (table); i++)
1067 if (table[i].name[0]
1068 && ! strcmp (asmspec, table[i].name))
1069 return table[i].number;
1071 #endif /* ADDITIONAL_REGISTER_NAMES */
1073 if (!strcmp (asmspec, "memory"))
1074 return -4;
1076 if (!strcmp (asmspec, "cc"))
1077 return -3;
1079 return -2;
1082 return -1;
1085 /* Return true if DECL's initializer is suitable for a BSS section. */
1087 static bool
1088 bss_initializer_p (const_tree decl)
1090 return (DECL_INITIAL (decl) == NULL
1091 || DECL_INITIAL (decl) == error_mark_node
1092 || (flag_zero_initialized_in_bss
1093 /* Leave constant zeroes in .rodata so they
1094 can be shared. */
1095 && !TREE_READONLY (decl)
1096 && initializer_zerop (DECL_INITIAL (decl))));
1099 /* Compute the alignment of variable specified by DECL.
1100 DONT_OUTPUT_DATA is from assemble_variable. */
1102 void
1103 align_variable (tree decl, bool dont_output_data)
1105 unsigned int align = DECL_ALIGN (decl);
1107 /* In the case for initialing an array whose length isn't specified,
1108 where we have not yet been able to do the layout,
1109 figure out the proper alignment now. */
1110 if (dont_output_data && DECL_SIZE (decl) == 0
1111 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
1112 align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
1114 /* Some object file formats have a maximum alignment which they support.
1115 In particular, a.out format supports a maximum alignment of 4. */
1116 if (align > MAX_OFILE_ALIGNMENT)
1118 warning (0, "alignment of %q+D is greater than maximum object "
1119 "file alignment. Using %d", decl,
1120 MAX_OFILE_ALIGNMENT/BITS_PER_UNIT);
1121 align = MAX_OFILE_ALIGNMENT;
1124 /* On some machines, it is good to increase alignment sometimes. */
1125 if (! DECL_USER_ALIGN (decl))
1127 #ifdef DATA_ALIGNMENT
1128 unsigned int data_align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
1129 /* Don't increase alignment too much for TLS variables - TLS space
1130 is too precious. */
1131 if (! DECL_THREAD_LOCAL_P (decl) || data_align <= BITS_PER_WORD)
1132 align = data_align;
1133 #endif
1134 #ifdef CONSTANT_ALIGNMENT
1135 if (DECL_INITIAL (decl) != 0 && DECL_INITIAL (decl) != error_mark_node)
1137 unsigned int const_align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl),
1138 align);
1139 /* Don't increase alignment too much for TLS variables - TLS space
1140 is too precious. */
1141 if (! DECL_THREAD_LOCAL_P (decl) || const_align <= BITS_PER_WORD)
1142 align = const_align;
1144 #endif
1147 /* Reset the alignment in case we have made it tighter, so we can benefit
1148 from it in get_pointer_alignment. */
1149 DECL_ALIGN (decl) = align;
1152 /* Return the section into which the given VAR_DECL or CONST_DECL
1153 should be placed. PREFER_NOSWITCH_P is true if a noswitch
1154 section should be used wherever possible. */
1156 static section *
1157 get_variable_section (tree decl, bool prefer_noswitch_p)
1159 int reloc;
1161 /* If the decl has been given an explicit section name, then it
1162 isn't common, and shouldn't be handled as such. */
1163 if (DECL_COMMON (decl) && DECL_SECTION_NAME (decl) == NULL)
1165 if (DECL_THREAD_LOCAL_P (decl))
1166 return tls_comm_section;
1167 /* This cannot be common bss for an emulated TLS object without
1168 a register_common hook. */
1169 else if (DECL_TLS_MODEL (decl) == TLS_MODEL_EMULATED
1170 && !targetm.emutls.register_common)
1172 else if (TREE_PUBLIC (decl) && bss_initializer_p (decl))
1173 return comm_section;
1176 if (DECL_INITIAL (decl) == error_mark_node)
1177 reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;
1178 else if (DECL_INITIAL (decl))
1179 reloc = compute_reloc_for_constant (DECL_INITIAL (decl));
1180 else
1181 reloc = 0;
1183 resolve_unique_section (decl, reloc, flag_data_sections);
1184 if (IN_NAMED_SECTION (decl))
1185 return get_named_section (decl, NULL, reloc);
1187 if (!DECL_THREAD_LOCAL_P (decl)
1188 && !(prefer_noswitch_p && targetm.have_switchable_bss_sections)
1189 && bss_initializer_p (decl))
1191 if (!TREE_PUBLIC (decl))
1192 return lcomm_section;
1193 if (bss_noswitch_section)
1194 return bss_noswitch_section;
1197 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
1200 /* Return the block into which object_block DECL should be placed. */
1202 static struct object_block *
1203 get_block_for_decl (tree decl)
1205 section *sect;
1207 if (TREE_CODE (decl) == VAR_DECL)
1209 /* The object must be defined in this translation unit. */
1210 if (DECL_EXTERNAL (decl))
1211 return NULL;
1213 /* There's no point using object blocks for something that is
1214 isolated by definition. */
1215 if (DECL_ONE_ONLY (decl))
1216 return NULL;
1219 /* We can only calculate block offsets if the decl has a known
1220 constant size. */
1221 if (DECL_SIZE_UNIT (decl) == NULL)
1222 return NULL;
1223 if (!host_integerp (DECL_SIZE_UNIT (decl), 1))
1224 return NULL;
1226 /* Find out which section should contain DECL. We cannot put it into
1227 an object block if it requires a standalone definition. */
1228 if (TREE_CODE (decl) == VAR_DECL)
1229 align_variable (decl, 0);
1230 sect = get_variable_section (decl, true);
1231 if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
1232 return NULL;
1234 return get_block_for_section (sect);
1237 /* Make sure block symbol SYMBOL is in block BLOCK. */
1239 static void
1240 change_symbol_block (rtx symbol, struct object_block *block)
1242 if (block != SYMBOL_REF_BLOCK (symbol))
1244 gcc_assert (SYMBOL_REF_BLOCK_OFFSET (symbol) < 0);
1245 SYMBOL_REF_BLOCK (symbol) = block;
1249 /* Return true if it is possible to put DECL in an object_block. */
1251 static bool
1252 use_blocks_for_decl_p (tree decl)
1254 /* Only data DECLs can be placed into object blocks. */
1255 if (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != CONST_DECL)
1256 return false;
1258 /* Detect decls created by dw2_force_const_mem. Such decls are
1259 special because DECL_INITIAL doesn't specify the decl's true value.
1260 dw2_output_indirect_constants will instead call assemble_variable
1261 with dont_output_data set to 1 and then print the contents itself. */
1262 if (DECL_INITIAL (decl) == decl)
1263 return false;
1265 /* If this decl is an alias, then we don't want to emit a definition. */
1266 if (lookup_attribute ("alias", DECL_ATTRIBUTES (decl)))
1267 return false;
1269 return true;
1272 /* Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL should
1273 have static storage duration. In other words, it should not be an
1274 automatic variable, including PARM_DECLs.
1276 There is, however, one exception: this function handles variables
1277 explicitly placed in a particular register by the user.
1279 This is never called for PARM_DECL nodes. */
1281 void
1282 make_decl_rtl (tree decl)
1284 const char *name = 0;
1285 int reg_number;
1286 rtx x;
1288 /* Check that we are not being given an automatic variable. */
1289 gcc_assert (TREE_CODE (decl) != PARM_DECL
1290 && TREE_CODE (decl) != RESULT_DECL);
1292 /* A weak alias has TREE_PUBLIC set but not the other bits. */
1293 gcc_assert (TREE_CODE (decl) != VAR_DECL
1294 || TREE_STATIC (decl)
1295 || TREE_PUBLIC (decl)
1296 || DECL_EXTERNAL (decl)
1297 || DECL_REGISTER (decl));
1299 /* And that we were not given a type or a label. */
1300 gcc_assert (TREE_CODE (decl) != TYPE_DECL
1301 && TREE_CODE (decl) != LABEL_DECL);
1303 /* For a duplicate declaration, we can be called twice on the
1304 same DECL node. Don't discard the RTL already made. */
1305 if (DECL_RTL_SET_P (decl))
1307 /* If the old RTL had the wrong mode, fix the mode. */
1308 x = DECL_RTL (decl);
1309 if (GET_MODE (x) != DECL_MODE (decl))
1310 SET_DECL_RTL (decl, adjust_address_nv (x, DECL_MODE (decl), 0));
1312 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1313 return;
1315 /* ??? Another way to do this would be to maintain a hashed
1316 table of such critters. Instead of adding stuff to a DECL
1317 to give certain attributes to it, we could use an external
1318 hash map from DECL to set of attributes. */
1320 /* Let the target reassign the RTL if it wants.
1321 This is necessary, for example, when one machine specific
1322 decl attribute overrides another. */
1323 targetm.encode_section_info (decl, DECL_RTL (decl), false);
1325 /* If the symbol has a SYMBOL_REF_BLOCK field, update it based
1326 on the new decl information. */
1327 if (MEM_P (x)
1328 && GET_CODE (XEXP (x, 0)) == SYMBOL_REF
1329 && SYMBOL_REF_HAS_BLOCK_INFO_P (XEXP (x, 0)))
1330 change_symbol_block (XEXP (x, 0), get_block_for_decl (decl));
1332 /* Make this function static known to the mudflap runtime. */
1333 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
1334 mudflap_enqueue_decl (decl);
1336 return;
1339 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
1341 if (name[0] != '*' && TREE_CODE (decl) != FUNCTION_DECL
1342 && DECL_REGISTER (decl))
1344 error ("register name not specified for %q+D", decl);
1346 else if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1348 const char *asmspec = name+1;
1349 reg_number = decode_reg_name (asmspec);
1350 /* First detect errors in declaring global registers. */
1351 if (reg_number == -1)
1352 error ("register name not specified for %q+D", decl);
1353 else if (reg_number < 0)
1354 error ("invalid register name for %q+D", decl);
1355 else if (TYPE_MODE (TREE_TYPE (decl)) == BLKmode)
1356 error ("data type of %q+D isn%'t suitable for a register",
1357 decl);
1358 else if (! HARD_REGNO_MODE_OK (reg_number, TYPE_MODE (TREE_TYPE (decl))))
1359 error ("register specified for %q+D isn%'t suitable for data type",
1360 decl);
1361 /* Now handle properly declared static register variables. */
1362 else
1364 int nregs;
1366 if (DECL_INITIAL (decl) != 0 && TREE_STATIC (decl))
1368 DECL_INITIAL (decl) = 0;
1369 error ("global register variable has initial value");
1371 if (TREE_THIS_VOLATILE (decl))
1372 warning (OPT_Wvolatile_register_var,
1373 "optimization may eliminate reads and/or "
1374 "writes to register variables");
1376 /* If the user specified one of the eliminables registers here,
1377 e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
1378 confused with that register and be eliminated. This usage is
1379 somewhat suspect... */
1381 SET_DECL_RTL (decl, gen_rtx_raw_REG (DECL_MODE (decl), reg_number));
1382 ORIGINAL_REGNO (DECL_RTL (decl)) = reg_number;
1383 REG_USERVAR_P (DECL_RTL (decl)) = 1;
1385 if (TREE_STATIC (decl))
1387 /* Make this register global, so not usable for anything
1388 else. */
1389 #ifdef ASM_DECLARE_REGISTER_GLOBAL
1390 name = IDENTIFIER_POINTER (DECL_NAME (decl));
1391 ASM_DECLARE_REGISTER_GLOBAL (asm_out_file, decl, reg_number, name);
1392 #endif
1393 nregs = hard_regno_nregs[reg_number][DECL_MODE (decl)];
1394 while (nregs > 0)
1395 globalize_reg (reg_number + --nregs);
1398 /* As a register variable, it has no section. */
1399 return;
1402 /* Now handle ordinary static variables and functions (in memory).
1403 Also handle vars declared register invalidly. */
1404 else if (name[0] == '*')
1406 #ifdef REGISTER_PREFIX
1407 if (strlen (REGISTER_PREFIX) != 0)
1409 reg_number = decode_reg_name (name);
1410 if (reg_number >= 0 || reg_number == -3)
1411 error ("register name given for non-register variable %q+D", decl);
1413 #endif
1416 /* Specifying a section attribute on a variable forces it into a
1417 non-.bss section, and thus it cannot be common. */
1418 if (TREE_CODE (decl) == VAR_DECL
1419 && DECL_SECTION_NAME (decl) != NULL_TREE
1420 && DECL_INITIAL (decl) == NULL_TREE
1421 && DECL_COMMON (decl))
1422 DECL_COMMON (decl) = 0;
1424 /* Variables can't be both common and weak. */
1425 if (TREE_CODE (decl) == VAR_DECL && DECL_WEAK (decl))
1426 DECL_COMMON (decl) = 0;
1428 if (use_object_blocks_p () && use_blocks_for_decl_p (decl))
1429 x = create_block_symbol (name, get_block_for_decl (decl), -1);
1430 else
1431 x = gen_rtx_SYMBOL_REF (Pmode, name);
1432 SYMBOL_REF_WEAK (x) = DECL_WEAK (decl);
1433 SET_SYMBOL_REF_DECL (x, decl);
1435 x = gen_rtx_MEM (DECL_MODE (decl), x);
1436 if (TREE_CODE (decl) != FUNCTION_DECL)
1437 set_mem_attributes (x, decl, 1);
1438 SET_DECL_RTL (decl, x);
1440 /* Optionally set flags or add text to the name to record information
1441 such as that it is a function name.
1442 If the name is changed, the macro ASM_OUTPUT_LABELREF
1443 will have to know how to strip this information. */
1444 targetm.encode_section_info (decl, DECL_RTL (decl), true);
1446 /* Make this function static known to the mudflap runtime. */
1447 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
1448 mudflap_enqueue_decl (decl);
1451 /* Output a string of literal assembler code
1452 for an `asm' keyword used between functions. */
1454 void
1455 assemble_asm (tree string)
1457 app_enable ();
1459 if (TREE_CODE (string) == ADDR_EXPR)
1460 string = TREE_OPERAND (string, 0);
1462 fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string));
1465 /* Record an element in the table of global destructors. SYMBOL is
1466 a SYMBOL_REF of the function to be called; PRIORITY is a number
1467 between 0 and MAX_INIT_PRIORITY. */
1469 void
1470 default_stabs_asm_out_destructor (rtx symbol ATTRIBUTE_UNUSED,
1471 int priority ATTRIBUTE_UNUSED)
1473 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1474 /* Tell GNU LD that this is part of the static destructor set.
1475 This will work for any system that uses stabs, most usefully
1476 aout systems. */
1477 dbxout_begin_simple_stabs ("___DTOR_LIST__", 22 /* N_SETT */);
1478 dbxout_stab_value_label (XSTR (symbol, 0));
1479 #else
1480 sorry ("global destructors not supported on this target");
1481 #endif
1484 /* Write the address of the entity given by SYMBOL to SEC. */
1485 void
1486 assemble_addr_to_section (rtx symbol, section *sec)
1488 switch_to_section (sec);
1489 assemble_align (POINTER_SIZE);
1490 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1493 /* Return the numbered .ctors.N (if CONSTRUCTOR_P) or .dtors.N (if
1494 not) section for PRIORITY. */
1495 section *
1496 get_cdtor_priority_section (int priority, bool constructor_p)
1498 char buf[16];
1500 /* ??? This only works reliably with the GNU linker. */
1501 sprintf (buf, "%s.%.5u",
1502 constructor_p ? ".ctors" : ".dtors",
1503 /* Invert the numbering so the linker puts us in the proper
1504 order; constructors are run from right to left, and the
1505 linker sorts in increasing order. */
1506 MAX_INIT_PRIORITY - priority);
1507 return get_section (buf, SECTION_WRITE, NULL);
1510 void
1511 default_named_section_asm_out_destructor (rtx symbol, int priority)
1513 section *sec;
1515 if (priority != DEFAULT_INIT_PRIORITY)
1516 sec = get_cdtor_priority_section (priority,
1517 /*constructor_p=*/false);
1518 else
1519 sec = get_section (".dtors", SECTION_WRITE, NULL);
1521 assemble_addr_to_section (symbol, sec);
1524 #ifdef DTORS_SECTION_ASM_OP
1525 void
1526 default_dtor_section_asm_out_destructor (rtx symbol,
1527 int priority ATTRIBUTE_UNUSED)
1529 assemble_addr_to_section (symbol, dtors_section);
1531 #endif
1533 /* Likewise for global constructors. */
1535 void
1536 default_stabs_asm_out_constructor (rtx symbol ATTRIBUTE_UNUSED,
1537 int priority ATTRIBUTE_UNUSED)
1539 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1540 /* Tell GNU LD that this is part of the static destructor set.
1541 This will work for any system that uses stabs, most usefully
1542 aout systems. */
1543 dbxout_begin_simple_stabs ("___CTOR_LIST__", 22 /* N_SETT */);
1544 dbxout_stab_value_label (XSTR (symbol, 0));
1545 #else
1546 sorry ("global constructors not supported on this target");
1547 #endif
1550 void
1551 default_named_section_asm_out_constructor (rtx symbol, int priority)
1553 section *sec;
1555 if (priority != DEFAULT_INIT_PRIORITY)
1556 sec = get_cdtor_priority_section (priority,
1557 /*constructor_p=*/true);
1558 else
1559 sec = get_section (".ctors", SECTION_WRITE, NULL);
1561 assemble_addr_to_section (symbol, sec);
1564 #ifdef CTORS_SECTION_ASM_OP
1565 void
1566 default_ctor_section_asm_out_constructor (rtx symbol,
1567 int priority ATTRIBUTE_UNUSED)
1569 assemble_addr_to_section (symbol, ctors_section);
1571 #endif
1573 /* CONSTANT_POOL_BEFORE_FUNCTION may be defined as an expression with
1574 a nonzero value if the constant pool should be output before the
1575 start of the function, or a zero value if the pool should output
1576 after the end of the function. The default is to put it before the
1577 start. */
1579 #ifndef CONSTANT_POOL_BEFORE_FUNCTION
1580 #define CONSTANT_POOL_BEFORE_FUNCTION 1
1581 #endif
1583 /* DECL is an object (either VAR_DECL or FUNCTION_DECL) which is going
1584 to be output to assembler.
1585 Set first_global_object_name and weak_global_object_name as appropriate. */
1587 void
1588 notice_global_symbol (tree decl)
1590 const char **type = &first_global_object_name;
1592 if (first_global_object_name
1593 || !TREE_PUBLIC (decl)
1594 || DECL_EXTERNAL (decl)
1595 || !DECL_NAME (decl)
1596 || (TREE_CODE (decl) != FUNCTION_DECL
1597 && (TREE_CODE (decl) != VAR_DECL
1598 || (DECL_COMMON (decl)
1599 && (DECL_INITIAL (decl) == 0
1600 || DECL_INITIAL (decl) == error_mark_node))))
1601 || !MEM_P (DECL_RTL (decl)))
1602 return;
1604 /* We win when global object is found, but it is useful to know about weak
1605 symbol as well so we can produce nicer unique names. */
1606 if (DECL_WEAK (decl) || DECL_ONE_ONLY (decl) || flag_shlib)
1607 type = &weak_global_object_name;
1609 if (!*type)
1611 const char *p;
1612 const char *name;
1613 rtx decl_rtl = DECL_RTL (decl);
1615 p = targetm.strip_name_encoding (XSTR (XEXP (decl_rtl, 0), 0));
1616 name = ggc_strdup (p);
1618 *type = name;
1622 /* Output assembler code for the constant pool of a function and associated
1623 with defining the name of the function. DECL describes the function.
1624 NAME is the function's name. For the constant pool, we use the current
1625 constant pool data. */
1627 void
1628 assemble_start_function (tree decl, const char *fnname)
1630 int align;
1631 char tmp_label[100];
1632 bool hot_label_written = false;
1634 crtl->subsections.unlikely_text_section_name = NULL;
1636 first_function_block_is_cold = false;
1637 if (flag_reorder_blocks_and_partition)
1639 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTB", const_labelno);
1640 crtl->subsections.hot_section_label = ggc_strdup (tmp_label);
1641 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDB", const_labelno);
1642 crtl->subsections.cold_section_label = ggc_strdup (tmp_label);
1643 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTE", const_labelno);
1644 crtl->subsections.hot_section_end_label = ggc_strdup (tmp_label);
1645 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDE", const_labelno);
1646 crtl->subsections.cold_section_end_label = ggc_strdup (tmp_label);
1647 const_labelno++;
1649 else
1651 crtl->subsections.hot_section_label = NULL;
1652 crtl->subsections.cold_section_label = NULL;
1653 crtl->subsections.hot_section_end_label = NULL;
1654 crtl->subsections.cold_section_end_label = NULL;
1657 /* The following code does not need preprocessing in the assembler. */
1659 app_disable ();
1661 if (CONSTANT_POOL_BEFORE_FUNCTION)
1662 output_constant_pool (fnname, decl);
1664 resolve_unique_section (decl, 0, flag_function_sections);
1666 /* Make sure the not and cold text (code) sections are properly
1667 aligned. This is necessary here in the case where the function
1668 has both hot and cold sections, because we don't want to re-set
1669 the alignment when the section switch happens mid-function. */
1671 if (flag_reorder_blocks_and_partition)
1673 switch_to_section (unlikely_text_section ());
1674 assemble_align (DECL_ALIGN (decl));
1675 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.cold_section_label);
1677 /* When the function starts with a cold section, we need to explicitly
1678 align the hot section and write out the hot section label.
1679 But if the current function is a thunk, we do not have a CFG. */
1680 if (!crtl->is_thunk
1681 && BB_PARTITION (ENTRY_BLOCK_PTR->next_bb) == BB_COLD_PARTITION)
1683 switch_to_section (text_section);
1684 assemble_align (DECL_ALIGN (decl));
1685 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_label);
1686 hot_label_written = true;
1687 first_function_block_is_cold = true;
1690 else if (DECL_SECTION_NAME (decl))
1692 /* Calls to function_section rely on first_function_block_is_cold
1693 being accurate. The first block may be cold even if we aren't
1694 doing partitioning, if the entire function was decided by
1695 choose_function_section (predict.c) to be cold. */
1697 initialize_cold_section_name ();
1699 if (crtl->subsections.unlikely_text_section_name
1700 && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
1701 crtl->subsections.unlikely_text_section_name) == 0)
1702 first_function_block_is_cold = true;
1705 in_cold_section_p = first_function_block_is_cold;
1707 /* Switch to the correct text section for the start of the function. */
1709 switch_to_section (function_section (decl));
1710 if (flag_reorder_blocks_and_partition
1711 && !hot_label_written)
1712 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_label);
1714 /* Tell assembler to move to target machine's alignment for functions. */
1715 align = floor_log2 (DECL_ALIGN (decl) / BITS_PER_UNIT);
1716 if (align > 0)
1718 ASM_OUTPUT_ALIGN (asm_out_file, align);
1721 /* Handle a user-specified function alignment.
1722 Note that we still need to align to DECL_ALIGN, as above,
1723 because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */
1724 if (! DECL_USER_ALIGN (decl)
1725 && align_functions_log > align
1726 && cfun->function_frequency != FUNCTION_FREQUENCY_UNLIKELY_EXECUTED)
1728 #ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
1729 ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file,
1730 align_functions_log, align_functions - 1);
1731 #else
1732 ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log);
1733 #endif
1736 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
1737 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
1738 #endif
1740 (*debug_hooks->begin_function) (decl);
1742 /* Make function name accessible from other files, if appropriate. */
1744 if (TREE_PUBLIC (decl))
1746 notice_global_symbol (decl);
1748 globalize_decl (decl);
1750 maybe_assemble_visibility (decl);
1753 if (DECL_PRESERVE_P (decl))
1754 targetm.asm_out.mark_decl_preserved (fnname);
1756 /* Do any machine/system dependent processing of the function name. */
1757 #ifdef ASM_DECLARE_FUNCTION_NAME
1758 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
1759 #else
1760 /* Standard thing is just output label for the function. */
1761 ASM_OUTPUT_LABEL (asm_out_file, fnname);
1762 #endif /* ASM_DECLARE_FUNCTION_NAME */
1765 /* Output assembler code associated with defining the size of the
1766 function. DECL describes the function. NAME is the function's name. */
1768 void
1769 assemble_end_function (tree decl, const char *fnname ATTRIBUTE_UNUSED)
1771 #ifdef ASM_DECLARE_FUNCTION_SIZE
1772 /* We could have switched section in the middle of the function. */
1773 if (flag_reorder_blocks_and_partition)
1774 switch_to_section (function_section (decl));
1775 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
1776 #endif
1777 if (! CONSTANT_POOL_BEFORE_FUNCTION)
1779 output_constant_pool (fnname, decl);
1780 switch_to_section (function_section (decl)); /* need to switch back */
1782 /* Output labels for end of hot/cold text sections (to be used by
1783 debug info.) */
1784 if (flag_reorder_blocks_and_partition)
1786 section *save_text_section;
1788 save_text_section = in_section;
1789 switch_to_section (unlikely_text_section ());
1790 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.cold_section_end_label);
1791 if (first_function_block_is_cold)
1792 switch_to_section (text_section);
1793 else
1794 switch_to_section (function_section (decl));
1795 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_end_label);
1796 switch_to_section (save_text_section);
1800 /* Assemble code to leave SIZE bytes of zeros. */
1802 void
1803 assemble_zeros (unsigned HOST_WIDE_INT size)
1805 /* Do no output if -fsyntax-only. */
1806 if (flag_syntax_only)
1807 return;
1809 #ifdef ASM_NO_SKIP_IN_TEXT
1810 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
1811 so we must output 0s explicitly in the text section. */
1812 if (ASM_NO_SKIP_IN_TEXT && (in_section->common.flags & SECTION_CODE) != 0)
1814 unsigned HOST_WIDE_INT i;
1815 for (i = 0; i < size; i++)
1816 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1);
1818 else
1819 #endif
1820 if (size > 0)
1821 ASM_OUTPUT_SKIP (asm_out_file, size);
1824 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
1826 void
1827 assemble_align (int align)
1829 if (align > BITS_PER_UNIT)
1831 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1835 /* Assemble a string constant with the specified C string as contents. */
1837 void
1838 assemble_string (const char *p, int size)
1840 int pos = 0;
1841 int maximum = 2000;
1843 /* If the string is very long, split it up. */
1845 while (pos < size)
1847 int thissize = size - pos;
1848 if (thissize > maximum)
1849 thissize = maximum;
1851 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
1853 pos += thissize;
1854 p += thissize;
1859 /* A noswitch_section_callback for lcomm_section. */
1861 static bool
1862 emit_local (tree decl ATTRIBUTE_UNUSED,
1863 const char *name ATTRIBUTE_UNUSED,
1864 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1865 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1867 #if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL
1868 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name,
1869 size, DECL_ALIGN (decl));
1870 return true;
1871 #elif defined ASM_OUTPUT_ALIGNED_LOCAL
1872 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl));
1873 return true;
1874 #else
1875 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1876 return false;
1877 #endif
1880 /* A noswitch_section_callback for bss_noswitch_section. */
1882 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
1883 static bool
1884 emit_bss (tree decl ATTRIBUTE_UNUSED,
1885 const char *name ATTRIBUTE_UNUSED,
1886 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1887 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1889 #if defined ASM_OUTPUT_ALIGNED_BSS
1890 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl));
1891 return true;
1892 #else
1893 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded);
1894 return false;
1895 #endif
1897 #endif
1899 /* A noswitch_section_callback for comm_section. */
1901 static bool
1902 emit_common (tree decl ATTRIBUTE_UNUSED,
1903 const char *name ATTRIBUTE_UNUSED,
1904 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1905 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1907 #if defined ASM_OUTPUT_ALIGNED_DECL_COMMON
1908 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name,
1909 size, DECL_ALIGN (decl));
1910 return true;
1911 #elif defined ASM_OUTPUT_ALIGNED_COMMON
1912 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl));
1913 return true;
1914 #else
1915 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded);
1916 return false;
1917 #endif
1920 /* A noswitch_section_callback for tls_comm_section. */
1922 static bool
1923 emit_tls_common (tree decl ATTRIBUTE_UNUSED,
1924 const char *name ATTRIBUTE_UNUSED,
1925 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1926 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1928 #ifdef ASM_OUTPUT_TLS_COMMON
1929 ASM_OUTPUT_TLS_COMMON (asm_out_file, decl, name, size);
1930 return true;
1931 #else
1932 sorry ("thread-local COMMON data not implemented");
1933 return true;
1934 #endif
1937 /* Assemble DECL given that it belongs in SECTION_NOSWITCH section SECT.
1938 NAME is the name of DECL's SYMBOL_REF. */
1940 static void
1941 assemble_noswitch_variable (tree decl, const char *name, section *sect)
1943 unsigned HOST_WIDE_INT size, rounded;
1945 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
1946 rounded = size;
1948 /* Don't allocate zero bytes of common,
1949 since that means "undefined external" in the linker. */
1950 if (size == 0)
1951 rounded = 1;
1953 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1954 so that each uninitialized object starts on such a boundary. */
1955 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
1956 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1957 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1959 if (!sect->noswitch.callback (decl, name, size, rounded)
1960 && (unsigned HOST_WIDE_INT) DECL_ALIGN_UNIT (decl) > rounded)
1961 warning (0, "requested alignment for %q+D is greater than "
1962 "implemented alignment of %wu", decl, rounded);
1965 /* A subroutine of assemble_variable. Output the label and contents of
1966 DECL, whose address is a SYMBOL_REF with name NAME. DONT_OUTPUT_DATA
1967 is as for assemble_variable. */
1969 static void
1970 assemble_variable_contents (tree decl, const char *name,
1971 bool dont_output_data)
1973 /* Do any machine/system dependent processing of the object. */
1974 #ifdef ASM_DECLARE_OBJECT_NAME
1975 last_assemble_variable_decl = decl;
1976 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
1977 #else
1978 /* Standard thing is just output label for the object. */
1979 ASM_OUTPUT_LABEL (asm_out_file, name);
1980 #endif /* ASM_DECLARE_OBJECT_NAME */
1982 if (!dont_output_data)
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_low_cst (DECL_SIZE_UNIT (decl), 1),
1990 DECL_ALIGN (decl));
1991 else
1992 /* Leave space for it. */
1993 assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1));
1997 /* Initialize emulated tls object TO, which refers to TLS variable
1998 DECL and is initialized by PROXY. */
2000 tree
2001 default_emutls_var_init (tree to, tree decl, tree proxy)
2003 VEC(constructor_elt,gc) *v = VEC_alloc (constructor_elt, gc, 4);
2004 constructor_elt *elt;
2005 tree type = TREE_TYPE (to);
2006 tree field = TYPE_FIELDS (type);
2008 elt = VEC_quick_push (constructor_elt, v, NULL);
2009 elt->index = field;
2010 elt->value = fold_convert (TREE_TYPE (field), DECL_SIZE_UNIT (decl));
2012 elt = VEC_quick_push (constructor_elt, v, NULL);
2013 field = TREE_CHAIN (field);
2014 elt->index = field;
2015 elt->value = build_int_cst (TREE_TYPE (field),
2016 DECL_ALIGN_UNIT (decl));
2018 elt = VEC_quick_push (constructor_elt, v, NULL);
2019 field = TREE_CHAIN (field);
2020 elt->index = field;
2021 elt->value = null_pointer_node;
2023 elt = VEC_quick_push (constructor_elt, v, NULL);
2024 field = TREE_CHAIN (field);
2025 elt->index = field;
2026 elt->value = proxy;
2028 return build_constructor (type, v);
2031 /* Assemble everything that is needed for a variable or function declaration.
2032 Not used for automatic variables, and not used for function definitions.
2033 Should not be called for variables of incomplete structure type.
2035 TOP_LEVEL is nonzero if this variable has file scope.
2036 AT_END is nonzero if this is the special handling, at end of compilation,
2037 to define things that have had only tentative definitions.
2038 DONT_OUTPUT_DATA if nonzero means don't actually output the
2039 initial value (that will be done by the caller). */
2041 void
2042 assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED,
2043 int at_end ATTRIBUTE_UNUSED, int dont_output_data)
2045 const char *name;
2046 rtx decl_rtl, symbol;
2047 section *sect;
2049 if (! targetm.have_tls
2050 && TREE_CODE (decl) == VAR_DECL
2051 && DECL_THREAD_LOCAL_P (decl))
2053 tree to = emutls_decl (decl);
2055 /* If this variable is defined locally, then we need to initialize the
2056 control structure with size and alignment information. We do this
2057 at the last moment because tentative definitions can take a locally
2058 defined but uninitialized variable and initialize it later, which
2059 would result in incorrect contents. */
2060 if (! DECL_EXTERNAL (to)
2061 && (! DECL_COMMON (to)
2062 || (DECL_INITIAL (decl)
2063 && DECL_INITIAL (decl) != error_mark_node)))
2065 DECL_INITIAL (to) = targetm.emutls.var_init
2066 (to, decl, get_emutls_init_templ_addr (decl));
2068 /* Make sure the template is marked as needed early enough.
2069 Without this, if the variable is placed in a
2070 section-anchored block, the template will only be marked
2071 when it's too late. */
2072 record_references_in_initializer (to);
2075 decl = to;
2078 last_assemble_variable_decl = 0;
2080 /* Normally no need to say anything here for external references,
2081 since assemble_external is called by the language-specific code
2082 when a declaration is first seen. */
2084 if (DECL_EXTERNAL (decl))
2085 return;
2087 /* Output no assembler code for a function declaration.
2088 Only definitions of functions output anything. */
2090 if (TREE_CODE (decl) == FUNCTION_DECL)
2091 return;
2093 /* Do nothing for global register variables. */
2094 if (DECL_RTL_SET_P (decl) && REG_P (DECL_RTL (decl)))
2096 TREE_ASM_WRITTEN (decl) = 1;
2097 return;
2100 /* If type was incomplete when the variable was declared,
2101 see if it is complete now. */
2103 if (DECL_SIZE (decl) == 0)
2104 layout_decl (decl, 0);
2106 /* Still incomplete => don't allocate it; treat the tentative defn
2107 (which is what it must have been) as an `extern' reference. */
2109 if (!dont_output_data && DECL_SIZE (decl) == 0)
2111 error ("storage size of %q+D isn%'t known", decl);
2112 TREE_ASM_WRITTEN (decl) = 1;
2113 return;
2116 /* The first declaration of a variable that comes through this function
2117 decides whether it is global (in C, has external linkage)
2118 or local (in C, has internal linkage). So do nothing more
2119 if this function has already run. */
2121 if (TREE_ASM_WRITTEN (decl))
2122 return;
2124 /* Make sure targetm.encode_section_info is invoked before we set
2125 ASM_WRITTEN. */
2126 decl_rtl = DECL_RTL (decl);
2128 TREE_ASM_WRITTEN (decl) = 1;
2130 /* Do no output if -fsyntax-only. */
2131 if (flag_syntax_only)
2132 return;
2134 app_disable ();
2136 if (! dont_output_data
2137 && ! host_integerp (DECL_SIZE_UNIT (decl), 1))
2139 error ("size of variable %q+D is too large", decl);
2140 return;
2143 gcc_assert (MEM_P (decl_rtl));
2144 gcc_assert (GET_CODE (XEXP (decl_rtl, 0)) == SYMBOL_REF);
2145 symbol = XEXP (decl_rtl, 0);
2146 name = XSTR (symbol, 0);
2147 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
2148 notice_global_symbol (decl);
2150 /* Compute the alignment of this data. */
2152 align_variable (decl, dont_output_data);
2153 set_mem_align (decl_rtl, DECL_ALIGN (decl));
2155 if (TREE_PUBLIC (decl))
2156 maybe_assemble_visibility (decl);
2158 if (DECL_PRESERVE_P (decl))
2159 targetm.asm_out.mark_decl_preserved (name);
2161 /* First make the assembler name(s) global if appropriate. */
2162 sect = get_variable_section (decl, false);
2163 if (TREE_PUBLIC (decl)
2164 && DECL_NAME (decl)
2165 && (sect->common.flags & SECTION_COMMON) == 0)
2166 globalize_decl (decl);
2168 /* Output any data that we will need to use the address of. */
2169 if (DECL_INITIAL (decl) && DECL_INITIAL (decl) != error_mark_node)
2170 output_addressed_constants (DECL_INITIAL (decl));
2172 /* dbxout.c needs to know this. */
2173 if (sect && (sect->common.flags & SECTION_CODE) != 0)
2174 DECL_IN_TEXT_SECTION (decl) = 1;
2176 /* If the decl is part of an object_block, make sure that the decl
2177 has been positioned within its block, but do not write out its
2178 definition yet. output_object_blocks will do that later. */
2179 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
2181 gcc_assert (!dont_output_data);
2182 place_block_symbol (symbol);
2184 else if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
2185 assemble_noswitch_variable (decl, name, sect);
2186 else
2188 switch_to_section (sect);
2189 if (DECL_ALIGN (decl) > BITS_PER_UNIT)
2190 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (DECL_ALIGN_UNIT (decl)));
2191 assemble_variable_contents (decl, name, dont_output_data);
2195 /* Return 1 if type TYPE contains any pointers. */
2197 static int
2198 contains_pointers_p (tree type)
2200 switch (TREE_CODE (type))
2202 case POINTER_TYPE:
2203 case REFERENCE_TYPE:
2204 /* I'm not sure whether OFFSET_TYPE needs this treatment,
2205 so I'll play safe and return 1. */
2206 case OFFSET_TYPE:
2207 return 1;
2209 case RECORD_TYPE:
2210 case UNION_TYPE:
2211 case QUAL_UNION_TYPE:
2213 tree fields;
2214 /* For a type that has fields, see if the fields have pointers. */
2215 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2216 if (TREE_CODE (fields) == FIELD_DECL
2217 && contains_pointers_p (TREE_TYPE (fields)))
2218 return 1;
2219 return 0;
2222 case ARRAY_TYPE:
2223 /* An array type contains pointers if its element type does. */
2224 return contains_pointers_p (TREE_TYPE (type));
2226 default:
2227 return 0;
2231 /* In unit-at-a-time mode, we delay assemble_external processing until
2232 the compilation unit is finalized. This is the best we can do for
2233 right now (i.e. stage 3 of GCC 4.0) - the right thing is to delay
2234 it all the way to final. See PR 17982 for further discussion. */
2235 static GTY(()) tree pending_assemble_externals;
2237 #ifdef ASM_OUTPUT_EXTERNAL
2238 /* True if DECL is a function decl for which no out-of-line copy exists.
2239 It is assumed that DECL's assembler name has been set. */
2241 static bool
2242 incorporeal_function_p (tree decl)
2244 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
2246 const char *name;
2248 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
2249 && DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA)
2250 return true;
2252 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
2253 if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
2254 return true;
2256 return false;
2259 /* Actually do the tests to determine if this is necessary, and invoke
2260 ASM_OUTPUT_EXTERNAL. */
2261 static void
2262 assemble_external_real (tree decl)
2264 rtx rtl = DECL_RTL (decl);
2266 if (MEM_P (rtl) && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
2267 && !SYMBOL_REF_USED (XEXP (rtl, 0))
2268 && !incorporeal_function_p (decl))
2270 /* Some systems do require some output. */
2271 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
2272 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
2275 #endif
2277 void
2278 process_pending_assemble_externals (void)
2280 #ifdef ASM_OUTPUT_EXTERNAL
2281 tree list;
2282 for (list = pending_assemble_externals; list; list = TREE_CHAIN (list))
2283 assemble_external_real (TREE_VALUE (list));
2285 pending_assemble_externals = 0;
2286 #endif
2289 /* Output something to declare an external symbol to the assembler.
2290 (Most assemblers don't need this, so we normally output nothing.)
2291 Do nothing if DECL is not external. */
2293 void
2294 assemble_external (tree decl ATTRIBUTE_UNUSED)
2296 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the
2297 main body of this code is only rarely exercised. To provide some
2298 testing, on all platforms, we make sure that the ASM_OUT_FILE is
2299 open. If it's not, we should not be calling this function. */
2300 gcc_assert (asm_out_file);
2302 #ifdef ASM_OUTPUT_EXTERNAL
2303 if (!DECL_P (decl) || !DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl))
2304 return;
2306 /* We want to output external symbols at very last to check if they
2307 are references or not. */
2308 pending_assemble_externals = tree_cons (0, decl,
2309 pending_assemble_externals);
2310 #endif
2313 /* Similar, for calling a library function FUN. */
2315 void
2316 assemble_external_libcall (rtx fun)
2318 /* Declare library function name external when first used, if nec. */
2319 if (! SYMBOL_REF_USED (fun))
2321 SYMBOL_REF_USED (fun) = 1;
2322 targetm.asm_out.external_libcall (fun);
2326 /* Assemble a label named NAME. */
2328 void
2329 assemble_label (const char *name)
2331 ASM_OUTPUT_LABEL (asm_out_file, name);
2334 /* Set the symbol_referenced flag for ID. */
2335 void
2336 mark_referenced (tree id)
2338 TREE_SYMBOL_REFERENCED (id) = 1;
2341 /* Set the symbol_referenced flag for DECL and notify callgraph. */
2342 void
2343 mark_decl_referenced (tree decl)
2345 if (TREE_CODE (decl) == FUNCTION_DECL)
2347 /* Extern inline functions don't become needed when referenced.
2348 If we know a method will be emitted in other TU and no new
2349 functions can be marked reachable, just use the external
2350 definition. */
2351 struct cgraph_node *node = cgraph_node (decl);
2352 if (!DECL_EXTERNAL (decl)
2353 && (!node->local.vtable_method || !cgraph_global_info_ready
2354 || !node->local.finalized))
2355 cgraph_mark_needed_node (node);
2357 else if (TREE_CODE (decl) == VAR_DECL)
2359 struct varpool_node *node = varpool_node (decl);
2360 varpool_mark_needed_node (node);
2361 /* C++ frontend use mark_decl_references to force COMDAT variables
2362 to be output that might appear dead otherwise. */
2363 node->force_output = true;
2365 /* else do nothing - we can get various sorts of CST nodes here,
2366 which do not need to be marked. */
2370 /* Follow the IDENTIFIER_TRANSPARENT_ALIAS chain starting at *ALIAS
2371 until we find an identifier that is not itself a transparent alias.
2372 Modify the alias passed to it by reference (and all aliases on the
2373 way to the ultimate target), such that they do not have to be
2374 followed again, and return the ultimate target of the alias
2375 chain. */
2377 static inline tree
2378 ultimate_transparent_alias_target (tree *alias)
2380 tree target = *alias;
2382 if (IDENTIFIER_TRANSPARENT_ALIAS (target))
2384 gcc_assert (TREE_CHAIN (target));
2385 target = ultimate_transparent_alias_target (&TREE_CHAIN (target));
2386 gcc_assert (! IDENTIFIER_TRANSPARENT_ALIAS (target)
2387 && ! TREE_CHAIN (target));
2388 *alias = target;
2391 return target;
2394 /* Output to FILE (an assembly file) a reference to NAME. If NAME
2395 starts with a *, the rest of NAME is output verbatim. Otherwise
2396 NAME is transformed in a target-specific way (usually by the
2397 addition of an underscore). */
2399 void
2400 assemble_name_raw (FILE *file, const char *name)
2402 if (name[0] == '*')
2403 fputs (&name[1], file);
2404 else
2405 ASM_OUTPUT_LABELREF (file, name);
2408 /* Like assemble_name_raw, but should be used when NAME might refer to
2409 an entity that is also represented as a tree (like a function or
2410 variable). If NAME does refer to such an entity, that entity will
2411 be marked as referenced. */
2413 void
2414 assemble_name (FILE *file, const char *name)
2416 const char *real_name;
2417 tree id;
2419 real_name = targetm.strip_name_encoding (name);
2421 id = maybe_get_identifier (real_name);
2422 if (id)
2424 tree id_orig = id;
2426 mark_referenced (id);
2427 ultimate_transparent_alias_target (&id);
2428 if (id != id_orig)
2429 name = IDENTIFIER_POINTER (id);
2430 gcc_assert (! TREE_CHAIN (id));
2433 assemble_name_raw (file, name);
2436 /* Allocate SIZE bytes writable static space with a gensym name
2437 and return an RTX to refer to its address. */
2440 assemble_static_space (unsigned HOST_WIDE_INT size)
2442 char name[12];
2443 const char *namestring;
2444 rtx x;
2446 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
2447 ++const_labelno;
2448 namestring = ggc_strdup (name);
2450 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
2451 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL;
2453 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
2454 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
2455 BIGGEST_ALIGNMENT);
2456 #else
2457 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
2458 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
2459 #else
2461 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
2462 so that each uninitialized object starts on such a boundary. */
2463 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */
2464 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED
2465 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
2466 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
2467 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
2468 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
2470 #endif
2471 #endif
2472 return x;
2475 /* Assemble the static constant template for function entry trampolines.
2476 This is done at most once per compilation.
2477 Returns an RTX for the address of the template. */
2479 static GTY(()) rtx initial_trampoline;
2481 #ifdef TRAMPOLINE_TEMPLATE
2483 assemble_trampoline_template (void)
2485 char label[256];
2486 const char *name;
2487 int align;
2488 rtx symbol;
2490 if (initial_trampoline)
2491 return initial_trampoline;
2493 /* By default, put trampoline templates in read-only data section. */
2495 #ifdef TRAMPOLINE_SECTION
2496 switch_to_section (TRAMPOLINE_SECTION);
2497 #else
2498 switch_to_section (readonly_data_section);
2499 #endif
2501 /* Write the assembler code to define one. */
2502 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
2503 if (align > 0)
2505 ASM_OUTPUT_ALIGN (asm_out_file, align);
2508 targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0);
2509 TRAMPOLINE_TEMPLATE (asm_out_file);
2511 /* Record the rtl to refer to it. */
2512 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
2513 name = ggc_strdup (label);
2514 symbol = gen_rtx_SYMBOL_REF (Pmode, name);
2515 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2517 initial_trampoline = gen_rtx_MEM (BLKmode, symbol);
2518 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
2520 return initial_trampoline;
2522 #endif
2524 /* A and B are either alignments or offsets. Return the minimum alignment
2525 that may be assumed after adding the two together. */
2527 static inline unsigned
2528 min_align (unsigned int a, unsigned int b)
2530 return (a | b) & -(a | b);
2533 /* Return the assembler directive for creating a given kind of integer
2534 object. SIZE is the number of bytes in the object and ALIGNED_P
2535 indicates whether it is known to be aligned. Return NULL if the
2536 assembly dialect has no such directive.
2538 The returned string should be printed at the start of a new line and
2539 be followed immediately by the object's initial value. */
2541 const char *
2542 integer_asm_op (int size, int aligned_p)
2544 struct asm_int_op *ops;
2546 if (aligned_p)
2547 ops = &targetm.asm_out.aligned_op;
2548 else
2549 ops = &targetm.asm_out.unaligned_op;
2551 switch (size)
2553 case 1:
2554 return targetm.asm_out.byte_op;
2555 case 2:
2556 return ops->hi;
2557 case 4:
2558 return ops->si;
2559 case 8:
2560 return ops->di;
2561 case 16:
2562 return ops->ti;
2563 default:
2564 return NULL;
2568 /* Use directive OP to assemble an integer object X. Print OP at the
2569 start of the line, followed immediately by the value of X. */
2571 void
2572 assemble_integer_with_op (const char *op, rtx x)
2574 fputs (op, asm_out_file);
2575 output_addr_const (asm_out_file, x);
2576 fputc ('\n', asm_out_file);
2579 /* The default implementation of the asm_out.integer target hook. */
2581 bool
2582 default_assemble_integer (rtx x ATTRIBUTE_UNUSED,
2583 unsigned int size ATTRIBUTE_UNUSED,
2584 int aligned_p ATTRIBUTE_UNUSED)
2586 const char *op = integer_asm_op (size, aligned_p);
2587 /* Avoid GAS bugs for large values. Specifically negative values whose
2588 absolute value fits in a bfd_vma, but not in a bfd_signed_vma. */
2589 if (size > UNITS_PER_WORD && size > POINTER_SIZE / BITS_PER_UNIT)
2590 return false;
2591 return op && (assemble_integer_with_op (op, x), true);
2594 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
2595 the alignment of the integer in bits. Return 1 if we were able to output
2596 the constant, otherwise 0. We must be able to output the constant,
2597 if FORCE is nonzero. */
2599 bool
2600 assemble_integer (rtx x, unsigned int size, unsigned int align, int force)
2602 int aligned_p;
2604 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT));
2606 /* See if the target hook can handle this kind of object. */
2607 if (targetm.asm_out.integer (x, size, aligned_p))
2608 return true;
2610 /* If the object is a multi-byte one, try splitting it up. Split
2611 it into words it if is multi-word, otherwise split it into bytes. */
2612 if (size > 1)
2614 enum machine_mode omode, imode;
2615 unsigned int subalign;
2616 unsigned int subsize, i;
2617 unsigned char mclass;
2619 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1;
2620 subalign = MIN (align, subsize * BITS_PER_UNIT);
2621 if (GET_CODE (x) == CONST_FIXED)
2622 mclass = GET_MODE_CLASS (GET_MODE (x));
2623 else
2624 mclass = MODE_INT;
2626 omode = mode_for_size (subsize * BITS_PER_UNIT, mclass, 0);
2627 imode = mode_for_size (size * BITS_PER_UNIT, mclass, 0);
2629 for (i = 0; i < size; i += subsize)
2631 rtx partial = simplify_subreg (omode, x, imode, i);
2632 if (!partial || !assemble_integer (partial, subsize, subalign, 0))
2633 break;
2635 if (i == size)
2636 return true;
2638 /* If we've printed some of it, but not all of it, there's no going
2639 back now. */
2640 gcc_assert (!i);
2643 gcc_assert (!force);
2645 return false;
2648 void
2649 assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align)
2651 long data[4] = {0, 0, 0, 0};
2652 int i;
2653 int bitsize, nelts, nunits, units_per;
2655 /* This is hairy. We have a quantity of known size. real_to_target
2656 will put it into an array of *host* longs, 32 bits per element
2657 (even if long is more than 32 bits). We need to determine the
2658 number of array elements that are occupied (nelts) and the number
2659 of *target* min-addressable units that will be occupied in the
2660 object file (nunits). We cannot assume that 32 divides the
2661 mode's bitsize (size * BITS_PER_UNIT) evenly.
2663 size * BITS_PER_UNIT is used here to make sure that padding bits
2664 (which might appear at either end of the value; real_to_target
2665 will include the padding bits in its output array) are included. */
2667 nunits = GET_MODE_SIZE (mode);
2668 bitsize = nunits * BITS_PER_UNIT;
2669 nelts = CEIL (bitsize, 32);
2670 units_per = 32 / BITS_PER_UNIT;
2672 real_to_target (data, &d, mode);
2674 /* Put out the first word with the specified alignment. */
2675 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1);
2676 nunits -= units_per;
2678 /* Subsequent words need only 32-bit alignment. */
2679 align = min_align (align, 32);
2681 for (i = 1; i < nelts; i++)
2683 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1);
2684 nunits -= units_per;
2688 /* Given an expression EXP with a constant value,
2689 reduce it to the sum of an assembler symbol and an integer.
2690 Store them both in the structure *VALUE.
2691 EXP must be reducible. */
2693 struct addr_const GTY(())
2695 rtx base;
2696 HOST_WIDE_INT offset;
2699 static void
2700 decode_addr_const (tree exp, struct addr_const *value)
2702 tree target = TREE_OPERAND (exp, 0);
2703 int offset = 0;
2704 rtx x;
2706 while (1)
2708 if (TREE_CODE (target) == COMPONENT_REF
2709 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0))
2712 offset += int_byte_position (TREE_OPERAND (target, 1));
2713 target = TREE_OPERAND (target, 0);
2715 else if (TREE_CODE (target) == ARRAY_REF
2716 || TREE_CODE (target) == ARRAY_RANGE_REF)
2718 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1)
2719 * tree_low_cst (TREE_OPERAND (target, 1), 0));
2720 target = TREE_OPERAND (target, 0);
2722 else
2723 break;
2726 switch (TREE_CODE (target))
2728 case VAR_DECL:
2729 case FUNCTION_DECL:
2730 x = DECL_RTL (target);
2731 break;
2733 case LABEL_DECL:
2734 x = gen_rtx_MEM (FUNCTION_MODE,
2735 gen_rtx_LABEL_REF (Pmode, force_label_rtx (target)));
2736 break;
2738 case REAL_CST:
2739 case FIXED_CST:
2740 case STRING_CST:
2741 case COMPLEX_CST:
2742 case CONSTRUCTOR:
2743 case INTEGER_CST:
2744 x = output_constant_def (target, 1);
2745 break;
2747 default:
2748 gcc_unreachable ();
2751 gcc_assert (MEM_P (x));
2752 x = XEXP (x, 0);
2754 value->base = x;
2755 value->offset = offset;
2758 /* Uniquize all constants that appear in memory.
2759 Each constant in memory thus far output is recorded
2760 in `const_desc_table'. */
2762 struct constant_descriptor_tree GTY(())
2764 /* A MEM for the constant. */
2765 rtx rtl;
2767 /* The value of the constant. */
2768 tree value;
2770 /* Hash of value. Computing the hash from value each time
2771 hashfn is called can't work properly, as that means recursive
2772 use of the hash table during hash table expansion. */
2773 hashval_t hash;
2776 static GTY((param_is (struct constant_descriptor_tree)))
2777 htab_t const_desc_htab;
2779 static struct constant_descriptor_tree * build_constant_desc (tree);
2780 static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int);
2782 /* Compute a hash code for a constant expression. */
2784 static hashval_t
2785 const_desc_hash (const void *ptr)
2787 return ((const struct constant_descriptor_tree *)ptr)->hash;
2790 static hashval_t
2791 const_hash_1 (const tree exp)
2793 const char *p;
2794 hashval_t hi;
2795 int len, i;
2796 enum tree_code code = TREE_CODE (exp);
2798 /* Either set P and LEN to the address and len of something to hash and
2799 exit the switch or return a value. */
2801 switch (code)
2803 case INTEGER_CST:
2804 p = (char *) &TREE_INT_CST (exp);
2805 len = sizeof TREE_INT_CST (exp);
2806 break;
2808 case REAL_CST:
2809 return real_hash (TREE_REAL_CST_PTR (exp));
2811 case FIXED_CST:
2812 return fixed_hash (TREE_FIXED_CST_PTR (exp));
2814 case STRING_CST:
2815 p = TREE_STRING_POINTER (exp);
2816 len = TREE_STRING_LENGTH (exp);
2817 break;
2819 case COMPLEX_CST:
2820 return (const_hash_1 (TREE_REALPART (exp)) * 5
2821 + const_hash_1 (TREE_IMAGPART (exp)));
2823 case CONSTRUCTOR:
2825 unsigned HOST_WIDE_INT idx;
2826 tree value;
2828 hi = 5 + int_size_in_bytes (TREE_TYPE (exp));
2830 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, value)
2831 if (value)
2832 hi = hi * 603 + const_hash_1 (value);
2834 return hi;
2837 case ADDR_EXPR:
2838 case FDESC_EXPR:
2840 struct addr_const value;
2842 decode_addr_const (exp, &value);
2843 switch (GET_CODE (value.base))
2845 case SYMBOL_REF:
2846 /* Don't hash the address of the SYMBOL_REF;
2847 only use the offset and the symbol name. */
2848 hi = value.offset;
2849 p = XSTR (value.base, 0);
2850 for (i = 0; p[i] != 0; i++)
2851 hi = ((hi * 613) + (unsigned) (p[i]));
2852 break;
2854 case LABEL_REF:
2855 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2856 break;
2858 default:
2859 gcc_unreachable ();
2862 return hi;
2864 case PLUS_EXPR:
2865 case POINTER_PLUS_EXPR:
2866 case MINUS_EXPR:
2867 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9
2868 + const_hash_1 (TREE_OPERAND (exp, 1)));
2870 CASE_CONVERT:
2871 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2;
2873 default:
2874 /* A language specific constant. Just hash the code. */
2875 return code;
2878 /* Compute hashing function. */
2879 hi = len;
2880 for (i = 0; i < len; i++)
2881 hi = ((hi * 613) + (unsigned) (p[i]));
2883 return hi;
2886 /* Wrapper of compare_constant, for the htab interface. */
2887 static int
2888 const_desc_eq (const void *p1, const void *p2)
2890 const struct constant_descriptor_tree *c1 = p1;
2891 const struct constant_descriptor_tree *c2 = p2;
2892 if (c1->hash != c2->hash)
2893 return 0;
2894 return compare_constant (c1->value, c2->value);
2897 /* Compare t1 and t2, and return 1 only if they are known to result in
2898 the same bit pattern on output. */
2900 static int
2901 compare_constant (const tree t1, const tree t2)
2903 enum tree_code typecode;
2905 if (t1 == NULL_TREE)
2906 return t2 == NULL_TREE;
2907 if (t2 == NULL_TREE)
2908 return 0;
2910 if (TREE_CODE (t1) != TREE_CODE (t2))
2911 return 0;
2913 switch (TREE_CODE (t1))
2915 case INTEGER_CST:
2916 /* Integer constants are the same only if the same width of type. */
2917 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2918 return 0;
2919 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2920 return 0;
2921 return tree_int_cst_equal (t1, t2);
2923 case REAL_CST:
2924 /* Real constants are the same only if the same width of type. */
2925 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2926 return 0;
2928 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2930 case FIXED_CST:
2931 /* Fixed constants are the same only if the same width of type. */
2932 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2933 return 0;
2935 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (t1), TREE_FIXED_CST (t2));
2937 case STRING_CST:
2938 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2939 return 0;
2941 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2942 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2943 TREE_STRING_LENGTH (t1)));
2945 case COMPLEX_CST:
2946 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2))
2947 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2)));
2949 case CONSTRUCTOR:
2951 VEC(constructor_elt, gc) *v1, *v2;
2952 unsigned HOST_WIDE_INT idx;
2954 typecode = TREE_CODE (TREE_TYPE (t1));
2955 if (typecode != TREE_CODE (TREE_TYPE (t2)))
2956 return 0;
2958 if (typecode == ARRAY_TYPE)
2960 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1));
2961 /* For arrays, check that the sizes all match. */
2962 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))
2963 || size_1 == -1
2964 || size_1 != int_size_in_bytes (TREE_TYPE (t2)))
2965 return 0;
2967 else
2969 /* For record and union constructors, require exact type
2970 equality. */
2971 if (TREE_TYPE (t1) != TREE_TYPE (t2))
2972 return 0;
2975 v1 = CONSTRUCTOR_ELTS (t1);
2976 v2 = CONSTRUCTOR_ELTS (t2);
2977 if (VEC_length (constructor_elt, v1)
2978 != VEC_length (constructor_elt, v2))
2979 return 0;
2981 for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx)
2983 constructor_elt *c1 = VEC_index (constructor_elt, v1, idx);
2984 constructor_elt *c2 = VEC_index (constructor_elt, v2, idx);
2986 /* Check that each value is the same... */
2987 if (!compare_constant (c1->value, c2->value))
2988 return 0;
2989 /* ... and that they apply to the same fields! */
2990 if (typecode == ARRAY_TYPE)
2992 if (!compare_constant (c1->index, c2->index))
2993 return 0;
2995 else
2997 if (c1->index != c2->index)
2998 return 0;
3002 return 1;
3005 case ADDR_EXPR:
3006 case FDESC_EXPR:
3008 struct addr_const value1, value2;
3010 decode_addr_const (t1, &value1);
3011 decode_addr_const (t2, &value2);
3012 return (value1.offset == value2.offset
3013 && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0);
3016 case PLUS_EXPR:
3017 case POINTER_PLUS_EXPR:
3018 case MINUS_EXPR:
3019 case RANGE_EXPR:
3020 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
3021 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
3023 CASE_CONVERT:
3024 case VIEW_CONVERT_EXPR:
3025 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3027 default:
3028 return 0;
3031 gcc_unreachable ();
3034 /* Make a copy of the whole tree structure for a constant. This
3035 handles the same types of nodes that compare_constant handles. */
3037 static tree
3038 copy_constant (tree exp)
3040 switch (TREE_CODE (exp))
3042 case ADDR_EXPR:
3043 /* For ADDR_EXPR, we do not want to copy the decl whose address
3044 is requested. We do want to copy constants though. */
3045 if (CONSTANT_CLASS_P (TREE_OPERAND (exp, 0)))
3046 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
3047 copy_constant (TREE_OPERAND (exp, 0)));
3048 else
3049 return copy_node (exp);
3051 case INTEGER_CST:
3052 case REAL_CST:
3053 case FIXED_CST:
3054 case STRING_CST:
3055 return copy_node (exp);
3057 case COMPLEX_CST:
3058 return build_complex (TREE_TYPE (exp),
3059 copy_constant (TREE_REALPART (exp)),
3060 copy_constant (TREE_IMAGPART (exp)));
3062 case PLUS_EXPR:
3063 case POINTER_PLUS_EXPR:
3064 case MINUS_EXPR:
3065 return build2 (TREE_CODE (exp), TREE_TYPE (exp),
3066 copy_constant (TREE_OPERAND (exp, 0)),
3067 copy_constant (TREE_OPERAND (exp, 1)));
3069 CASE_CONVERT:
3070 case VIEW_CONVERT_EXPR:
3071 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
3072 copy_constant (TREE_OPERAND (exp, 0)));
3074 case CONSTRUCTOR:
3076 tree copy = copy_node (exp);
3077 VEC(constructor_elt, gc) *v;
3078 unsigned HOST_WIDE_INT idx;
3079 tree purpose, value;
3081 v = VEC_alloc(constructor_elt, gc, VEC_length(constructor_elt,
3082 CONSTRUCTOR_ELTS (exp)));
3083 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (exp), idx, purpose, value)
3085 constructor_elt *ce = VEC_quick_push (constructor_elt, v, NULL);
3086 ce->index = purpose;
3087 ce->value = copy_constant (value);
3089 CONSTRUCTOR_ELTS (copy) = v;
3090 return copy;
3093 default:
3094 gcc_unreachable ();
3098 /* Return the alignment of constant EXP in bits. */
3100 static unsigned int
3101 get_constant_alignment (tree exp)
3103 unsigned int align;
3105 align = TYPE_ALIGN (TREE_TYPE (exp));
3106 #ifdef CONSTANT_ALIGNMENT
3107 align = CONSTANT_ALIGNMENT (exp, align);
3108 #endif
3109 return align;
3112 /* Return the section into which constant EXP should be placed. */
3114 static section *
3115 get_constant_section (tree exp)
3117 if (IN_NAMED_SECTION (exp))
3118 return get_named_section (exp, NULL, compute_reloc_for_constant (exp));
3119 else
3120 return targetm.asm_out.select_section (exp,
3121 compute_reloc_for_constant (exp),
3122 get_constant_alignment (exp));
3125 /* Return the size of constant EXP in bytes. */
3127 static HOST_WIDE_INT
3128 get_constant_size (tree exp)
3130 HOST_WIDE_INT size;
3132 size = int_size_in_bytes (TREE_TYPE (exp));
3133 if (TREE_CODE (exp) == STRING_CST)
3134 size = MAX (TREE_STRING_LENGTH (exp), size);
3135 return size;
3138 /* Subroutine of output_constant_def:
3139 No constant equal to EXP is known to have been output.
3140 Make a constant descriptor to enter EXP in the hash table.
3141 Assign the label number and construct RTL to refer to the
3142 constant's location in memory.
3143 Caller is responsible for updating the hash table. */
3145 static struct constant_descriptor_tree *
3146 build_constant_desc (tree exp)
3148 rtx symbol;
3149 rtx rtl;
3150 char label[256];
3151 int labelno;
3152 struct constant_descriptor_tree *desc;
3154 desc = ggc_alloc (sizeof (*desc));
3155 desc->value = copy_constant (exp);
3157 /* Propagate marked-ness to copied constant. */
3158 if (flag_mudflap && mf_marked_p (exp))
3159 mf_mark (desc->value);
3161 /* Create a string containing the label name, in LABEL. */
3162 labelno = const_labelno++;
3163 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno);
3165 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
3166 if (use_object_blocks_p ())
3168 section *sect = get_constant_section (exp);
3169 symbol = create_block_symbol (ggc_strdup (label),
3170 get_block_for_section (sect), -1);
3172 else
3173 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3174 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3175 SET_SYMBOL_REF_DECL (symbol, desc->value);
3176 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3178 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol);
3179 set_mem_attributes (rtl, exp, 1);
3180 set_mem_alias_set (rtl, 0);
3181 set_mem_alias_set (rtl, const_alias_set);
3183 /* Set flags or add text to the name to record information, such as
3184 that it is a local symbol. If the name is changed, the macro
3185 ASM_OUTPUT_LABELREF will have to know how to strip this
3186 information. This call might invalidate our local variable
3187 SYMBOL; we can't use it afterward. */
3189 targetm.encode_section_info (exp, rtl, true);
3191 desc->rtl = rtl;
3193 return desc;
3196 /* Return an rtx representing a reference to constant data in memory
3197 for the constant expression EXP.
3199 If assembler code for such a constant has already been output,
3200 return an rtx to refer to it.
3201 Otherwise, output such a constant in memory
3202 and generate an rtx for it.
3204 If DEFER is nonzero, this constant can be deferred and output only
3205 if referenced in the function after all optimizations.
3207 `const_desc_table' records which constants already have label strings. */
3210 output_constant_def (tree exp, int defer)
3212 struct constant_descriptor_tree *desc;
3213 struct constant_descriptor_tree key;
3214 void **loc;
3216 /* Look up EXP in the table of constant descriptors. If we didn't find
3217 it, create a new one. */
3218 key.value = exp;
3219 key.hash = const_hash_1 (exp);
3220 loc = htab_find_slot_with_hash (const_desc_htab, &key, key.hash, INSERT);
3222 desc = *loc;
3223 if (desc == 0)
3225 desc = build_constant_desc (exp);
3226 desc->hash = key.hash;
3227 *loc = desc;
3230 maybe_output_constant_def_contents (desc, defer);
3231 return desc->rtl;
3234 /* Subroutine of output_constant_def: Decide whether or not we need to
3235 output the constant DESC now, and if so, do it. */
3236 static void
3237 maybe_output_constant_def_contents (struct constant_descriptor_tree *desc,
3238 int defer)
3240 rtx symbol = XEXP (desc->rtl, 0);
3241 tree exp = desc->value;
3243 if (flag_syntax_only)
3244 return;
3246 if (TREE_ASM_WRITTEN (exp))
3247 /* Already output; don't do it again. */
3248 return;
3250 /* We can always defer constants as long as the context allows
3251 doing so. */
3252 if (defer)
3254 /* Increment n_deferred_constants if it exists. It needs to be at
3255 least as large as the number of constants actually referred to
3256 by the function. If it's too small we'll stop looking too early
3257 and fail to emit constants; if it's too large we'll only look
3258 through the entire function when we could have stopped earlier. */
3259 if (cfun)
3260 n_deferred_constants++;
3261 return;
3264 output_constant_def_contents (symbol);
3267 /* Subroutine of output_constant_def_contents. Output the definition
3268 of constant EXP, which is pointed to by label LABEL. ALIGN is the
3269 constant's alignment in bits. */
3271 static void
3272 assemble_constant_contents (tree exp, const char *label, unsigned int align)
3274 HOST_WIDE_INT size;
3276 size = get_constant_size (exp);
3278 /* Do any machine/system dependent processing of the constant. */
3279 #ifdef ASM_DECLARE_CONSTANT_NAME
3280 ASM_DECLARE_CONSTANT_NAME (asm_out_file, label, exp, size);
3281 #else
3282 /* Standard thing is just output label for the constant. */
3283 ASM_OUTPUT_LABEL (asm_out_file, label);
3284 #endif /* ASM_DECLARE_CONSTANT_NAME */
3286 /* Output the value of EXP. */
3287 output_constant (exp, size, align);
3290 /* We must output the constant data referred to by SYMBOL; do so. */
3292 static void
3293 output_constant_def_contents (rtx symbol)
3295 tree exp = SYMBOL_REF_DECL (symbol);
3296 unsigned int align;
3298 /* Make sure any other constants whose addresses appear in EXP
3299 are assigned label numbers. */
3300 output_addressed_constants (exp);
3302 /* We are no longer deferring this constant. */
3303 TREE_ASM_WRITTEN (exp) = 1;
3305 /* If the constant is part of an object block, make sure that the
3306 decl has been positioned within its block, but do not write out
3307 its definition yet. output_object_blocks will do that later. */
3308 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
3309 place_block_symbol (symbol);
3310 else
3312 switch_to_section (get_constant_section (exp));
3313 align = get_constant_alignment (exp);
3314 if (align > BITS_PER_UNIT)
3315 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
3316 assemble_constant_contents (exp, XSTR (symbol, 0), align);
3318 if (flag_mudflap)
3319 mudflap_enqueue_constant (exp);
3322 /* Look up EXP in the table of constant descriptors. Return the rtl
3323 if it has been emitted, else null. */
3326 lookup_constant_def (tree exp)
3328 struct constant_descriptor_tree *desc;
3329 struct constant_descriptor_tree key;
3331 key.value = exp;
3332 key.hash = const_hash_1 (exp);
3333 desc = htab_find_with_hash (const_desc_htab, &key, key.hash);
3335 return (desc ? desc->rtl : NULL_RTX);
3338 /* Used in the hash tables to avoid outputting the same constant
3339 twice. Unlike 'struct constant_descriptor_tree', RTX constants
3340 are output once per function, not once per file. */
3341 /* ??? Only a few targets need per-function constant pools. Most
3342 can use one per-file pool. Should add a targetm bit to tell the
3343 difference. */
3345 struct rtx_constant_pool GTY(())
3347 /* Pointers to first and last constant in pool, as ordered by offset. */
3348 struct constant_descriptor_rtx *first;
3349 struct constant_descriptor_rtx *last;
3351 /* Hash facility for making memory-constants from constant rtl-expressions.
3352 It is used on RISC machines where immediate integer arguments and
3353 constant addresses are restricted so that such constants must be stored
3354 in memory. */
3355 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab;
3357 /* Current offset in constant pool (does not include any
3358 machine-specific header). */
3359 HOST_WIDE_INT offset;
3362 struct constant_descriptor_rtx GTY((chain_next ("%h.next")))
3364 struct constant_descriptor_rtx *next;
3365 rtx mem;
3366 rtx sym;
3367 rtx constant;
3368 HOST_WIDE_INT offset;
3369 hashval_t hash;
3370 enum machine_mode mode;
3371 unsigned int align;
3372 int labelno;
3373 int mark;
3376 /* Hash and compare functions for const_rtx_htab. */
3378 static hashval_t
3379 const_desc_rtx_hash (const void *ptr)
3381 const struct constant_descriptor_rtx *desc = ptr;
3382 return desc->hash;
3385 static int
3386 const_desc_rtx_eq (const void *a, const void *b)
3388 const struct constant_descriptor_rtx *x = a;
3389 const struct constant_descriptor_rtx *y = b;
3391 if (x->mode != y->mode)
3392 return 0;
3393 return rtx_equal_p (x->constant, y->constant);
3396 /* This is the worker function for const_rtx_hash, called via for_each_rtx. */
3398 static int
3399 const_rtx_hash_1 (rtx *xp, void *data)
3401 unsigned HOST_WIDE_INT hwi;
3402 enum machine_mode mode;
3403 enum rtx_code code;
3404 hashval_t h, *hp;
3405 rtx x;
3407 x = *xp;
3408 code = GET_CODE (x);
3409 mode = GET_MODE (x);
3410 h = (hashval_t) code * 1048573 + mode;
3412 switch (code)
3414 case CONST_INT:
3415 hwi = INTVAL (x);
3416 fold_hwi:
3418 const int shift = sizeof (hashval_t) * CHAR_BIT;
3419 const int n = sizeof (HOST_WIDE_INT) / sizeof (hashval_t);
3420 int i;
3422 h ^= (hashval_t) hwi;
3423 for (i = 1; i < n; ++i)
3425 hwi >>= shift;
3426 h ^= (hashval_t) hwi;
3429 break;
3431 case CONST_DOUBLE:
3432 if (mode == VOIDmode)
3434 hwi = CONST_DOUBLE_LOW (x) ^ CONST_DOUBLE_HIGH (x);
3435 goto fold_hwi;
3437 else
3438 h ^= real_hash (CONST_DOUBLE_REAL_VALUE (x));
3439 break;
3441 case CONST_FIXED:
3442 h ^= fixed_hash (CONST_FIXED_VALUE (x));
3443 break;
3445 case CONST_VECTOR:
3447 int i;
3448 for (i = XVECLEN (x, 0); i-- > 0; )
3449 h = h * 251 + const_rtx_hash_1 (&XVECEXP (x, 0, i), data);
3451 break;
3453 case SYMBOL_REF:
3454 h ^= htab_hash_string (XSTR (x, 0));
3455 break;
3457 case LABEL_REF:
3458 h = h * 251 + CODE_LABEL_NUMBER (XEXP (x, 0));
3459 break;
3461 case UNSPEC:
3462 case UNSPEC_VOLATILE:
3463 h = h * 251 + XINT (x, 1);
3464 break;
3466 default:
3467 break;
3470 hp = data;
3471 *hp = *hp * 509 + h;
3472 return 0;
3475 /* Compute a hash value for X, which should be a constant. */
3477 static hashval_t
3478 const_rtx_hash (rtx x)
3480 hashval_t h = 0;
3481 for_each_rtx (&x, const_rtx_hash_1, &h);
3482 return h;
3486 /* Create and return a new rtx constant pool. */
3488 static struct rtx_constant_pool *
3489 create_constant_pool (void)
3491 struct rtx_constant_pool *pool;
3493 pool = ggc_alloc (sizeof (struct rtx_constant_pool));
3494 pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash,
3495 const_desc_rtx_eq, NULL);
3496 pool->first = NULL;
3497 pool->last = NULL;
3498 pool->offset = 0;
3499 return pool;
3502 /* Initialize constant pool hashing for a new function. */
3504 void
3505 init_varasm_status (void)
3507 crtl->varasm.pool = create_constant_pool ();
3508 crtl->varasm.deferred_constants = 0;
3511 /* Given a MINUS expression, simplify it if both sides
3512 include the same symbol. */
3515 simplify_subtraction (rtx x)
3517 rtx r = simplify_rtx (x);
3518 return r ? r : x;
3521 /* Given a constant rtx X, make (or find) a memory constant for its value
3522 and return a MEM rtx to refer to it in memory. */
3525 force_const_mem (enum machine_mode mode, rtx x)
3527 struct constant_descriptor_rtx *desc, tmp;
3528 struct rtx_constant_pool *pool;
3529 char label[256];
3530 rtx def, symbol;
3531 hashval_t hash;
3532 unsigned int align;
3533 void **slot;
3535 /* If we're not allowed to drop X into the constant pool, don't. */
3536 if (targetm.cannot_force_const_mem (x))
3537 return NULL_RTX;
3539 /* Record that this function has used a constant pool entry. */
3540 crtl->uses_const_pool = 1;
3542 /* Decide which pool to use. */
3543 pool = (targetm.use_blocks_for_constant_p (mode, x)
3544 ? shared_constant_pool
3545 : crtl->varasm.pool);
3547 /* Lookup the value in the hashtable. */
3548 tmp.constant = x;
3549 tmp.mode = mode;
3550 hash = const_rtx_hash (x);
3551 slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT);
3552 desc = *slot;
3554 /* If the constant was already present, return its memory. */
3555 if (desc)
3556 return copy_rtx (desc->mem);
3558 /* Otherwise, create a new descriptor. */
3559 desc = ggc_alloc (sizeof (*desc));
3560 *slot = desc;
3562 /* Align the location counter as required by EXP's data type. */
3563 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode);
3564 #ifdef CONSTANT_ALIGNMENT
3566 tree type = lang_hooks.types.type_for_mode (mode, 0);
3567 if (type != NULL_TREE)
3568 align = CONSTANT_ALIGNMENT (make_tree (type, x), align);
3570 #endif
3572 pool->offset += (align / BITS_PER_UNIT) - 1;
3573 pool->offset &= ~ ((align / BITS_PER_UNIT) - 1);
3575 desc->next = NULL;
3576 desc->constant = tmp.constant;
3577 desc->offset = pool->offset;
3578 desc->hash = hash;
3579 desc->mode = mode;
3580 desc->align = align;
3581 desc->labelno = const_labelno;
3582 desc->mark = 0;
3584 pool->offset += GET_MODE_SIZE (mode);
3585 if (pool->last)
3586 pool->last->next = desc;
3587 else
3588 pool->first = pool->last = desc;
3589 pool->last = desc;
3591 /* Create a string containing the label name, in LABEL. */
3592 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
3593 ++const_labelno;
3595 /* Construct the SYMBOL_REF. Make sure to mark it as belonging to
3596 the constants pool. */
3597 if (use_object_blocks_p () && targetm.use_blocks_for_constant_p (mode, x))
3599 section *sect = targetm.asm_out.select_rtx_section (mode, x, align);
3600 symbol = create_block_symbol (ggc_strdup (label),
3601 get_block_for_section (sect), -1);
3603 else
3604 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3605 desc->sym = symbol;
3606 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3607 CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3608 SET_SYMBOL_REF_CONSTANT (symbol, desc);
3610 /* Construct the MEM. */
3611 desc->mem = def = gen_const_mem (mode, symbol);
3612 set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1);
3613 set_mem_align (def, align);
3615 /* If we're dropping a label to the constant pool, make sure we
3616 don't delete it. */
3617 if (GET_CODE (x) == LABEL_REF)
3618 LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
3620 return copy_rtx (def);
3623 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
3626 get_pool_constant (rtx addr)
3628 return SYMBOL_REF_CONSTANT (addr)->constant;
3631 /* Given a constant pool SYMBOL_REF, return the corresponding constant
3632 and whether it has been output or not. */
3635 get_pool_constant_mark (rtx addr, bool *pmarked)
3637 struct constant_descriptor_rtx *desc;
3639 desc = SYMBOL_REF_CONSTANT (addr);
3640 *pmarked = (desc->mark != 0);
3641 return desc->constant;
3644 /* Similar, return the mode. */
3646 enum machine_mode
3647 get_pool_mode (const_rtx addr)
3649 return SYMBOL_REF_CONSTANT (addr)->mode;
3652 /* Return the size of the constant pool. */
3655 get_pool_size (void)
3657 return crtl->varasm.pool->offset;
3660 /* Worker function for output_constant_pool_1. Emit assembly for X
3661 in MODE with known alignment ALIGN. */
3663 static void
3664 output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align)
3666 switch (GET_MODE_CLASS (mode))
3668 case MODE_FLOAT:
3669 case MODE_DECIMAL_FLOAT:
3671 REAL_VALUE_TYPE r;
3673 gcc_assert (GET_CODE (x) == CONST_DOUBLE);
3674 REAL_VALUE_FROM_CONST_DOUBLE (r, x);
3675 assemble_real (r, mode, align);
3676 break;
3679 case MODE_INT:
3680 case MODE_PARTIAL_INT:
3681 case MODE_FRACT:
3682 case MODE_UFRACT:
3683 case MODE_ACCUM:
3684 case MODE_UACCUM:
3685 assemble_integer (x, GET_MODE_SIZE (mode), align, 1);
3686 break;
3688 case MODE_VECTOR_FLOAT:
3689 case MODE_VECTOR_INT:
3690 case MODE_VECTOR_FRACT:
3691 case MODE_VECTOR_UFRACT:
3692 case MODE_VECTOR_ACCUM:
3693 case MODE_VECTOR_UACCUM:
3695 int i, units;
3696 enum machine_mode submode = GET_MODE_INNER (mode);
3697 unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode));
3699 gcc_assert (GET_CODE (x) == CONST_VECTOR);
3700 units = CONST_VECTOR_NUNITS (x);
3702 for (i = 0; i < units; i++)
3704 rtx elt = CONST_VECTOR_ELT (x, i);
3705 output_constant_pool_2 (submode, elt, i ? subalign : align);
3708 break;
3710 default:
3711 gcc_unreachable ();
3715 /* Worker function for output_constant_pool. Emit constant DESC,
3716 giving it ALIGN bits of alignment. */
3718 static void
3719 output_constant_pool_1 (struct constant_descriptor_rtx *desc,
3720 unsigned int align)
3722 rtx x, tmp;
3724 x = desc->constant;
3726 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3727 whose CODE_LABEL has been deleted. This can occur if a jump table
3728 is eliminated by optimization. If so, write a constant of zero
3729 instead. Note that this can also happen by turning the
3730 CODE_LABEL into a NOTE. */
3731 /* ??? This seems completely and utterly wrong. Certainly it's
3732 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper
3733 functioning even with INSN_DELETED_P and friends. */
3735 tmp = x;
3736 switch (GET_CODE (tmp))
3738 case CONST:
3739 if (GET_CODE (XEXP (tmp, 0)) != PLUS
3740 || GET_CODE (XEXP (XEXP (tmp, 0), 0)) != LABEL_REF)
3741 break;
3742 tmp = XEXP (XEXP (tmp, 0), 0);
3743 /* FALLTHRU */
3745 case LABEL_REF:
3746 tmp = XEXP (tmp, 0);
3747 gcc_assert (!INSN_DELETED_P (tmp));
3748 gcc_assert (!NOTE_P (tmp)
3749 || NOTE_KIND (tmp) != NOTE_INSN_DELETED);
3750 break;
3752 default:
3753 break;
3756 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3757 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode,
3758 align, desc->labelno, done);
3759 #endif
3761 assemble_align (align);
3763 /* Output the label. */
3764 targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno);
3766 /* Output the data. */
3767 output_constant_pool_2 (desc->mode, x, align);
3769 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS
3770 sections have proper size. */
3771 if (align > GET_MODE_BITSIZE (desc->mode)
3772 && in_section
3773 && (in_section->common.flags & SECTION_MERGE))
3774 assemble_align (align);
3776 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3777 done:
3778 #endif
3779 return;
3782 /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
3783 to as used. Emit referenced deferred strings. This function can
3784 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */
3786 static int
3787 mark_constant (rtx *current_rtx, void *data ATTRIBUTE_UNUSED)
3789 rtx x = *current_rtx;
3791 if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF)
3792 return 0;
3794 if (CONSTANT_POOL_ADDRESS_P (x))
3796 struct constant_descriptor_rtx *desc = SYMBOL_REF_CONSTANT (x);
3797 if (desc->mark == 0)
3799 desc->mark = 1;
3800 for_each_rtx (&desc->constant, mark_constant, NULL);
3803 else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
3805 tree exp = SYMBOL_REF_DECL (x);
3806 if (!TREE_ASM_WRITTEN (exp))
3808 n_deferred_constants--;
3809 output_constant_def_contents (x);
3813 return -1;
3816 /* Look through appropriate parts of INSN, marking all entries in the
3817 constant pool which are actually being used. Entries that are only
3818 referenced by other constants are also marked as used. Emit
3819 deferred strings that are used. */
3821 static void
3822 mark_constants (rtx insn)
3824 if (!INSN_P (insn))
3825 return;
3827 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3828 insns, not any notes that may be attached. We don't want to mark
3829 a constant just because it happens to appear in a REG_EQUIV note. */
3830 if (GET_CODE (PATTERN (insn)) == SEQUENCE)
3832 rtx seq = PATTERN (insn);
3833 int i, n = XVECLEN (seq, 0);
3834 for (i = 0; i < n; ++i)
3836 rtx subinsn = XVECEXP (seq, 0, i);
3837 if (INSN_P (subinsn))
3838 for_each_rtx (&PATTERN (subinsn), mark_constant, NULL);
3841 else
3842 for_each_rtx (&PATTERN (insn), mark_constant, NULL);
3845 /* Look through the instructions for this function, and mark all the
3846 entries in POOL which are actually being used. Emit deferred constants
3847 which have indeed been used. */
3849 static void
3850 mark_constant_pool (void)
3852 rtx insn, link;
3854 if (!crtl->uses_const_pool && n_deferred_constants == 0)
3855 return;
3857 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3858 mark_constants (insn);
3860 for (link = crtl->epilogue_delay_list;
3861 link;
3862 link = XEXP (link, 1))
3863 mark_constants (XEXP (link, 0));
3866 /* Write all the constants in POOL. */
3868 static void
3869 output_constant_pool_contents (struct rtx_constant_pool *pool)
3871 struct constant_descriptor_rtx *desc;
3873 for (desc = pool->first; desc ; desc = desc->next)
3874 if (desc->mark)
3876 /* If the constant is part of an object_block, make sure that
3877 the constant has been positioned within its block, but do not
3878 write out its definition yet. output_object_blocks will do
3879 that later. */
3880 if (SYMBOL_REF_HAS_BLOCK_INFO_P (desc->sym)
3881 && SYMBOL_REF_BLOCK (desc->sym))
3882 place_block_symbol (desc->sym);
3883 else
3885 switch_to_section (targetm.asm_out.select_rtx_section
3886 (desc->mode, desc->constant, desc->align));
3887 output_constant_pool_1 (desc, desc->align);
3892 /* Mark all constants that are used in the current function, then write
3893 out the function's private constant pool. */
3895 static void
3896 output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
3897 tree fndecl ATTRIBUTE_UNUSED)
3899 struct rtx_constant_pool *pool = crtl->varasm.pool;
3901 /* It is possible for gcc to call force_const_mem and then to later
3902 discard the instructions which refer to the constant. In such a
3903 case we do not need to output the constant. */
3904 mark_constant_pool ();
3906 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3907 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset);
3908 #endif
3910 output_constant_pool_contents (pool);
3912 #ifdef ASM_OUTPUT_POOL_EPILOGUE
3913 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset);
3914 #endif
3917 /* Write the contents of the shared constant pool. */
3919 void
3920 output_shared_constant_pool (void)
3922 output_constant_pool_contents (shared_constant_pool);
3925 /* Determine what kind of relocations EXP may need. */
3928 compute_reloc_for_constant (tree exp)
3930 int reloc = 0, reloc2;
3931 tree tem;
3933 switch (TREE_CODE (exp))
3935 case ADDR_EXPR:
3936 case FDESC_EXPR:
3937 /* Go inside any operations that get_inner_reference can handle and see
3938 if what's inside is a constant: no need to do anything here for
3939 addresses of variables or functions. */
3940 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3941 tem = TREE_OPERAND (tem, 0))
3944 if (TREE_PUBLIC (tem))
3945 reloc |= 2;
3946 else
3947 reloc |= 1;
3948 break;
3950 case PLUS_EXPR:
3951 case POINTER_PLUS_EXPR:
3952 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3953 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3954 break;
3956 case MINUS_EXPR:
3957 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3958 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3959 /* The difference of two local labels is computable at link time. */
3960 if (reloc == 1 && reloc2 == 1)
3961 reloc = 0;
3962 else
3963 reloc |= reloc2;
3964 break;
3966 CASE_CONVERT:
3967 case VIEW_CONVERT_EXPR:
3968 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3969 break;
3971 case CONSTRUCTOR:
3973 unsigned HOST_WIDE_INT idx;
3974 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
3975 if (tem != 0)
3976 reloc |= compute_reloc_for_constant (tem);
3978 break;
3980 default:
3981 break;
3983 return reloc;
3986 /* Find all the constants whose addresses are referenced inside of EXP,
3987 and make sure assembler code with a label has been output for each one.
3988 Indicate whether an ADDR_EXPR has been encountered. */
3990 static void
3991 output_addressed_constants (tree exp)
3993 tree tem;
3995 switch (TREE_CODE (exp))
3997 case ADDR_EXPR:
3998 case FDESC_EXPR:
3999 /* Go inside any operations that get_inner_reference can handle and see
4000 if what's inside is a constant: no need to do anything here for
4001 addresses of variables or functions. */
4002 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
4003 tem = TREE_OPERAND (tem, 0))
4006 /* If we have an initialized CONST_DECL, retrieve the initializer. */
4007 if (TREE_CODE (tem) == CONST_DECL && DECL_INITIAL (tem))
4008 tem = DECL_INITIAL (tem);
4010 if (CONSTANT_CLASS_P (tem) || TREE_CODE (tem) == CONSTRUCTOR)
4011 output_constant_def (tem, 0);
4012 break;
4014 case PLUS_EXPR:
4015 case POINTER_PLUS_EXPR:
4016 case MINUS_EXPR:
4017 output_addressed_constants (TREE_OPERAND (exp, 1));
4018 /* Fall through. */
4020 CASE_CONVERT:
4021 case VIEW_CONVERT_EXPR:
4022 output_addressed_constants (TREE_OPERAND (exp, 0));
4023 break;
4025 case CONSTRUCTOR:
4027 unsigned HOST_WIDE_INT idx;
4028 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
4029 if (tem != 0)
4030 output_addressed_constants (tem);
4032 break;
4034 default:
4035 break;
4039 /* Whether a constructor CTOR is a valid static constant initializer if all
4040 its elements are. This used to be internal to initializer_constant_valid_p
4041 and has been exposed to let other functions like categorize_ctor_elements
4042 evaluate the property while walking a constructor for other purposes. */
4044 bool
4045 constructor_static_from_elts_p (const_tree ctor)
4047 return (TREE_CONSTANT (ctor)
4048 && (TREE_CODE (TREE_TYPE (ctor)) == UNION_TYPE
4049 || TREE_CODE (TREE_TYPE (ctor)) == RECORD_TYPE)
4050 && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (ctor)));
4053 /* Return nonzero if VALUE is a valid constant-valued expression
4054 for use in initializing a static variable; one that can be an
4055 element of a "constant" initializer.
4057 Return null_pointer_node if the value is absolute;
4058 if it is relocatable, return the variable that determines the relocation.
4059 We assume that VALUE has been folded as much as possible;
4060 therefore, we do not need to check for such things as
4061 arithmetic-combinations of integers. */
4063 tree
4064 initializer_constant_valid_p (tree value, tree endtype)
4066 switch (TREE_CODE (value))
4068 case CONSTRUCTOR:
4069 if (constructor_static_from_elts_p (value))
4071 unsigned HOST_WIDE_INT idx;
4072 tree elt;
4073 bool absolute = true;
4075 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
4077 tree reloc;
4078 reloc = initializer_constant_valid_p (elt, TREE_TYPE (elt));
4079 if (!reloc)
4080 return NULL_TREE;
4081 if (reloc != null_pointer_node)
4082 absolute = false;
4084 /* For a non-absolute relocation, there is no single
4085 variable that can be "the variable that determines the
4086 relocation." */
4087 return absolute ? null_pointer_node : error_mark_node;
4090 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE;
4092 case INTEGER_CST:
4093 case VECTOR_CST:
4094 case REAL_CST:
4095 case FIXED_CST:
4096 case STRING_CST:
4097 case COMPLEX_CST:
4098 return null_pointer_node;
4100 case ADDR_EXPR:
4101 case FDESC_EXPR:
4102 value = staticp (TREE_OPERAND (value, 0));
4103 if (value)
4105 /* "&(*a).f" is like unto pointer arithmetic. If "a" turns out to
4106 be a constant, this is old-skool offsetof-like nonsense. */
4107 if (TREE_CODE (value) == INDIRECT_REF
4108 && TREE_CONSTANT (TREE_OPERAND (value, 0)))
4109 return null_pointer_node;
4110 /* Taking the address of a nested function involves a trampoline. */
4111 if (TREE_CODE (value) == FUNCTION_DECL
4112 && decl_function_context (value)
4113 && !DECL_NO_STATIC_CHAIN (value))
4114 return NULL_TREE;
4115 /* "&{...}" requires a temporary to hold the constructed
4116 object. */
4117 if (TREE_CODE (value) == CONSTRUCTOR)
4118 return NULL_TREE;
4120 return value;
4122 case VIEW_CONVERT_EXPR:
4123 case NON_LVALUE_EXPR:
4124 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
4126 CASE_CONVERT:
4128 tree src;
4129 tree src_type;
4130 tree dest_type;
4132 src = TREE_OPERAND (value, 0);
4133 src_type = TREE_TYPE (src);
4134 dest_type = TREE_TYPE (value);
4136 /* Allow conversions between pointer types, floating-point
4137 types, and offset types. */
4138 if ((POINTER_TYPE_P (dest_type) && POINTER_TYPE_P (src_type))
4139 || (FLOAT_TYPE_P (dest_type) && FLOAT_TYPE_P (src_type))
4140 || (TREE_CODE (dest_type) == OFFSET_TYPE
4141 && TREE_CODE (src_type) == OFFSET_TYPE))
4142 return initializer_constant_valid_p (src, endtype);
4144 /* Allow length-preserving conversions between integer types. */
4145 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type)
4146 && (TYPE_PRECISION (dest_type) == TYPE_PRECISION (src_type)))
4147 return initializer_constant_valid_p (src, endtype);
4149 /* Allow conversions between other integer types only if
4150 explicit value. */
4151 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type))
4153 tree inner = initializer_constant_valid_p (src, endtype);
4154 if (inner == null_pointer_node)
4155 return null_pointer_node;
4156 break;
4159 /* Allow (int) &foo provided int is as wide as a pointer. */
4160 if (INTEGRAL_TYPE_P (dest_type) && POINTER_TYPE_P (src_type)
4161 && (TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type)))
4162 return initializer_constant_valid_p (src, endtype);
4164 /* Likewise conversions from int to pointers, but also allow
4165 conversions from 0. */
4166 if ((POINTER_TYPE_P (dest_type)
4167 || TREE_CODE (dest_type) == OFFSET_TYPE)
4168 && INTEGRAL_TYPE_P (src_type))
4170 if (TREE_CODE (src) == INTEGER_CST
4171 && TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type))
4172 return null_pointer_node;
4173 if (integer_zerop (src))
4174 return null_pointer_node;
4175 else if (TYPE_PRECISION (dest_type) <= TYPE_PRECISION (src_type))
4176 return initializer_constant_valid_p (src, endtype);
4179 /* Allow conversions to struct or union types if the value
4180 inside is okay. */
4181 if (TREE_CODE (dest_type) == RECORD_TYPE
4182 || TREE_CODE (dest_type) == UNION_TYPE)
4183 return initializer_constant_valid_p (src, endtype);
4185 break;
4187 case POINTER_PLUS_EXPR:
4188 case PLUS_EXPR:
4189 if (! INTEGRAL_TYPE_P (endtype)
4190 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
4192 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
4193 endtype);
4194 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
4195 endtype);
4196 /* If either term is absolute, use the other term's relocation. */
4197 if (valid0 == null_pointer_node)
4198 return valid1;
4199 if (valid1 == null_pointer_node)
4200 return valid0;
4202 break;
4204 case MINUS_EXPR:
4205 if (! INTEGRAL_TYPE_P (endtype)
4206 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
4208 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
4209 endtype);
4210 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
4211 endtype);
4212 /* Win if second argument is absolute. */
4213 if (valid1 == null_pointer_node)
4214 return valid0;
4215 /* Win if both arguments have the same relocation.
4216 Then the value is absolute. */
4217 if (valid0 == valid1 && valid0 != 0)
4218 return null_pointer_node;
4220 /* Since GCC guarantees that string constants are unique in the
4221 generated code, a subtraction between two copies of the same
4222 constant string is absolute. */
4223 if (valid0 && TREE_CODE (valid0) == STRING_CST
4224 && valid1 && TREE_CODE (valid1) == STRING_CST
4225 && operand_equal_p (valid0, valid1, 1))
4226 return null_pointer_node;
4229 /* Support narrowing differences. */
4230 if (INTEGRAL_TYPE_P (endtype))
4232 tree op0, op1;
4234 op0 = TREE_OPERAND (value, 0);
4235 op1 = TREE_OPERAND (value, 1);
4237 /* Like STRIP_NOPS except allow the operand mode to widen.
4238 This works around a feature of fold that simplifies
4239 (int)(p1 - p2) to ((int)p1 - (int)p2) under the theory
4240 that the narrower operation is cheaper. */
4242 while (CONVERT_EXPR_P (op0)
4243 || TREE_CODE (op0) == NON_LVALUE_EXPR)
4245 tree inner = TREE_OPERAND (op0, 0);
4246 if (inner == error_mark_node
4247 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4248 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))
4249 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4250 break;
4251 op0 = inner;
4254 while (CONVERT_EXPR_P (op1)
4255 || TREE_CODE (op1) == NON_LVALUE_EXPR)
4257 tree inner = TREE_OPERAND (op1, 0);
4258 if (inner == error_mark_node
4259 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4260 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))
4261 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4262 break;
4263 op1 = inner;
4266 op0 = initializer_constant_valid_p (op0, endtype);
4267 op1 = initializer_constant_valid_p (op1, endtype);
4269 /* Both initializers must be known. */
4270 if (op0 && op1)
4272 if (op0 == op1)
4273 return null_pointer_node;
4275 /* Support differences between labels. */
4276 if (TREE_CODE (op0) == LABEL_DECL
4277 && TREE_CODE (op1) == LABEL_DECL)
4278 return null_pointer_node;
4280 if (TREE_CODE (op0) == STRING_CST
4281 && TREE_CODE (op1) == STRING_CST
4282 && operand_equal_p (op0, op1, 1))
4283 return null_pointer_node;
4286 break;
4288 default:
4289 break;
4292 return 0;
4295 /* Output assembler code for constant EXP to FILE, with no label.
4296 This includes the pseudo-op such as ".int" or ".byte", and a newline.
4297 Assumes output_addressed_constants has been done on EXP already.
4299 Generate exactly SIZE bytes of assembler data, padding at the end
4300 with zeros if necessary. SIZE must always be specified.
4302 SIZE is important for structure constructors,
4303 since trailing members may have been omitted from the constructor.
4304 It is also important for initialization of arrays from string constants
4305 since the full length of the string constant might not be wanted.
4306 It is also needed for initialization of unions, where the initializer's
4307 type is just one member, and that may not be as long as the union.
4309 There a case in which we would fail to output exactly SIZE bytes:
4310 for a structure constructor that wants to produce more than SIZE bytes.
4311 But such constructors will never be generated for any possible input.
4313 ALIGN is the alignment of the data in bits. */
4315 void
4316 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
4318 enum tree_code code;
4319 unsigned HOST_WIDE_INT thissize;
4321 if (size == 0 || flag_syntax_only)
4322 return;
4324 /* See if we're trying to initialize a pointer in a non-default mode
4325 to the address of some declaration somewhere. If the target says
4326 the mode is valid for pointers, assume the target has a way of
4327 resolving it. */
4328 if (TREE_CODE (exp) == NOP_EXPR
4329 && POINTER_TYPE_P (TREE_TYPE (exp))
4330 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
4332 tree saved_type = TREE_TYPE (exp);
4334 /* Peel off any intermediate conversions-to-pointer for valid
4335 pointer modes. */
4336 while (TREE_CODE (exp) == NOP_EXPR
4337 && POINTER_TYPE_P (TREE_TYPE (exp))
4338 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
4339 exp = TREE_OPERAND (exp, 0);
4341 /* If what we're left with is the address of something, we can
4342 convert the address to the final type and output it that
4343 way. */
4344 if (TREE_CODE (exp) == ADDR_EXPR)
4345 exp = build1 (ADDR_EXPR, saved_type, TREE_OPERAND (exp, 0));
4346 /* Likewise for constant ints. */
4347 else if (TREE_CODE (exp) == INTEGER_CST)
4348 exp = build_int_cst_wide (saved_type, TREE_INT_CST_LOW (exp),
4349 TREE_INT_CST_HIGH (exp));
4353 /* Eliminate any conversions since we'll be outputting the underlying
4354 constant. */
4355 while (CONVERT_EXPR_P (exp)
4356 || TREE_CODE (exp) == NON_LVALUE_EXPR
4357 || TREE_CODE (exp) == VIEW_CONVERT_EXPR)
4359 HOST_WIDE_INT type_size = int_size_in_bytes (TREE_TYPE (exp));
4360 HOST_WIDE_INT op_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (exp, 0)));
4362 /* Make sure eliminating the conversion is really a no-op, except with
4363 VIEW_CONVERT_EXPRs to allow for wild Ada unchecked conversions and
4364 union types to allow for Ada unchecked unions. */
4365 if (type_size > op_size
4366 && TREE_CODE (exp) != VIEW_CONVERT_EXPR
4367 && TREE_CODE (TREE_TYPE (exp)) != UNION_TYPE)
4368 /* Keep the conversion. */
4369 break;
4370 else
4371 exp = TREE_OPERAND (exp, 0);
4374 code = TREE_CODE (TREE_TYPE (exp));
4375 thissize = int_size_in_bytes (TREE_TYPE (exp));
4377 /* Allow a constructor with no elements for any data type.
4378 This means to fill the space with zeros. */
4379 if (TREE_CODE (exp) == CONSTRUCTOR
4380 && VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (exp)))
4382 assemble_zeros (size);
4383 return;
4386 if (TREE_CODE (exp) == FDESC_EXPR)
4388 #ifdef ASM_OUTPUT_FDESC
4389 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0);
4390 tree decl = TREE_OPERAND (exp, 0);
4391 ASM_OUTPUT_FDESC (asm_out_file, decl, part);
4392 #else
4393 gcc_unreachable ();
4394 #endif
4395 return;
4398 /* Now output the underlying data. If we've handling the padding, return.
4399 Otherwise, break and ensure SIZE is the size written. */
4400 switch (code)
4402 case BOOLEAN_TYPE:
4403 case INTEGER_TYPE:
4404 case ENUMERAL_TYPE:
4405 case POINTER_TYPE:
4406 case REFERENCE_TYPE:
4407 case OFFSET_TYPE:
4408 case FIXED_POINT_TYPE:
4409 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
4410 EXPAND_INITIALIZER),
4411 MIN (size, thissize), align, 0))
4412 error ("initializer for integer/fixed-point value is too complicated");
4413 break;
4415 case REAL_TYPE:
4416 if (TREE_CODE (exp) != REAL_CST)
4417 error ("initializer for floating value is not a floating constant");
4419 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
4420 break;
4422 case COMPLEX_TYPE:
4423 output_constant (TREE_REALPART (exp), thissize / 2, align);
4424 output_constant (TREE_IMAGPART (exp), thissize / 2,
4425 min_align (align, BITS_PER_UNIT * (thissize / 2)));
4426 break;
4428 case ARRAY_TYPE:
4429 case VECTOR_TYPE:
4430 switch (TREE_CODE (exp))
4432 case CONSTRUCTOR:
4433 output_constructor (exp, size, align);
4434 return;
4435 case STRING_CST:
4436 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp),
4437 size);
4438 assemble_string (TREE_STRING_POINTER (exp), thissize);
4439 break;
4441 case VECTOR_CST:
4443 int elt_size;
4444 tree link;
4445 unsigned int nalign;
4446 enum machine_mode inner;
4448 inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp)));
4449 nalign = MIN (align, GET_MODE_ALIGNMENT (inner));
4451 elt_size = GET_MODE_SIZE (inner);
4453 link = TREE_VECTOR_CST_ELTS (exp);
4454 output_constant (TREE_VALUE (link), elt_size, align);
4455 thissize = elt_size;
4456 while ((link = TREE_CHAIN (link)) != NULL)
4458 output_constant (TREE_VALUE (link), elt_size, nalign);
4459 thissize += elt_size;
4461 break;
4463 default:
4464 gcc_unreachable ();
4466 break;
4468 case RECORD_TYPE:
4469 case UNION_TYPE:
4470 gcc_assert (TREE_CODE (exp) == CONSTRUCTOR);
4471 output_constructor (exp, size, align);
4472 return;
4474 case ERROR_MARK:
4475 return;
4477 default:
4478 gcc_unreachable ();
4481 if (size > thissize)
4482 assemble_zeros (size - thissize);
4486 /* Subroutine of output_constructor, used for computing the size of
4487 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array
4488 type with an unspecified upper bound. */
4490 static unsigned HOST_WIDE_INT
4491 array_size_for_constructor (tree val)
4493 tree max_index, i;
4494 unsigned HOST_WIDE_INT cnt;
4495 tree index, value, tmp;
4497 /* This code used to attempt to handle string constants that are not
4498 arrays of single-bytes, but nothing else does, so there's no point in
4499 doing it here. */
4500 if (TREE_CODE (val) == STRING_CST)
4501 return TREE_STRING_LENGTH (val);
4503 max_index = NULL_TREE;
4504 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (val), cnt, index, value)
4506 if (TREE_CODE (index) == RANGE_EXPR)
4507 index = TREE_OPERAND (index, 1);
4508 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index))
4509 max_index = index;
4512 if (max_index == NULL_TREE)
4513 return 0;
4515 /* Compute the total number of array elements. */
4516 tmp = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val)));
4517 i = size_binop (MINUS_EXPR, fold_convert (sizetype, max_index),
4518 fold_convert (sizetype, tmp));
4519 i = size_binop (PLUS_EXPR, i, build_int_cst (sizetype, 1));
4521 /* Multiply by the array element unit size to find number of bytes. */
4522 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val))));
4524 return tree_low_cst (i, 1);
4527 /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants).
4528 Generate at least SIZE bytes, padding if necessary. */
4530 static void
4531 output_constructor (tree exp, unsigned HOST_WIDE_INT size,
4532 unsigned int align)
4534 tree type = TREE_TYPE (exp);
4535 tree field = 0;
4536 tree min_index = 0;
4537 /* Number of bytes output or skipped so far.
4538 In other words, current position within the constructor. */
4539 HOST_WIDE_INT total_bytes = 0;
4540 /* Nonzero means BYTE contains part of a byte, to be output. */
4541 int byte_buffer_in_use = 0;
4542 int byte = 0;
4543 unsigned HOST_WIDE_INT cnt;
4544 constructor_elt *ce;
4546 gcc_assert (HOST_BITS_PER_WIDE_INT >= BITS_PER_UNIT);
4548 if (TREE_CODE (type) == RECORD_TYPE)
4549 field = TYPE_FIELDS (type);
4551 if (TREE_CODE (type) == ARRAY_TYPE
4552 && TYPE_DOMAIN (type) != 0)
4553 min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
4555 /* As LINK goes through the elements of the constant,
4556 FIELD goes through the structure fields, if the constant is a structure.
4557 if the constant is a union, then we override this,
4558 by getting the field from the TREE_LIST element.
4559 But the constant could also be an array. Then FIELD is zero.
4561 There is always a maximum of one element in the chain LINK for unions
4562 (even if the initializer in a source program incorrectly contains
4563 more one). */
4564 for (cnt = 0;
4565 VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (exp), cnt, ce);
4566 cnt++, field = field ? TREE_CHAIN (field) : 0)
4568 tree val = ce->value;
4569 tree index = 0;
4571 /* The element in a union constructor specifies the proper field
4572 or index. */
4573 if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE
4574 || TREE_CODE (type) == QUAL_UNION_TYPE)
4575 && ce->index != 0)
4576 field = ce->index;
4578 else if (TREE_CODE (type) == ARRAY_TYPE)
4579 index = ce->index;
4581 #ifdef ASM_COMMENT_START
4582 if (field && flag_verbose_asm)
4583 fprintf (asm_out_file, "%s %s:\n",
4584 ASM_COMMENT_START,
4585 DECL_NAME (field)
4586 ? IDENTIFIER_POINTER (DECL_NAME (field))
4587 : "<anonymous>");
4588 #endif
4590 /* Eliminate the marker that makes a cast not be an lvalue. */
4591 if (val != 0)
4592 STRIP_NOPS (val);
4594 if (index && TREE_CODE (index) == RANGE_EXPR)
4596 unsigned HOST_WIDE_INT fieldsize
4597 = int_size_in_bytes (TREE_TYPE (type));
4598 HOST_WIDE_INT lo_index = tree_low_cst (TREE_OPERAND (index, 0), 0);
4599 HOST_WIDE_INT hi_index = tree_low_cst (TREE_OPERAND (index, 1), 0);
4600 HOST_WIDE_INT index;
4601 unsigned int align2 = min_align (align, fieldsize * BITS_PER_UNIT);
4603 for (index = lo_index; index <= hi_index; index++)
4605 /* Output the element's initial value. */
4606 if (val == 0)
4607 assemble_zeros (fieldsize);
4608 else
4609 output_constant (val, fieldsize, align2);
4611 /* Count its size. */
4612 total_bytes += fieldsize;
4615 else if (field == 0 || !DECL_BIT_FIELD (field))
4617 /* An element that is not a bit-field. */
4619 unsigned HOST_WIDE_INT fieldsize;
4620 /* Since this structure is static,
4621 we know the positions are constant. */
4622 HOST_WIDE_INT pos = field ? int_byte_position (field) : 0;
4623 unsigned int align2;
4625 if (index != 0)
4626 pos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (val)), 1)
4627 * (tree_low_cst (index, 0) - tree_low_cst (min_index, 0)));
4629 /* Output any buffered-up bit-fields preceding this element. */
4630 if (byte_buffer_in_use)
4632 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4633 total_bytes++;
4634 byte_buffer_in_use = 0;
4637 /* Advance to offset of this element.
4638 Note no alignment needed in an array, since that is guaranteed
4639 if each element has the proper size. */
4640 if ((field != 0 || index != 0) && pos != total_bytes)
4642 gcc_assert (pos >= total_bytes);
4643 assemble_zeros (pos - total_bytes);
4644 total_bytes = pos;
4647 /* Find the alignment of this element. */
4648 align2 = min_align (align, BITS_PER_UNIT * pos);
4650 /* Determine size this element should occupy. */
4651 if (field)
4653 fieldsize = 0;
4655 /* If this is an array with an unspecified upper bound,
4656 the initializer determines the size. */
4657 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL,
4658 but we cannot do this until the deprecated support for
4659 initializing zero-length array members is removed. */
4660 if (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE
4661 && TYPE_DOMAIN (TREE_TYPE (field))
4662 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (field))))
4664 fieldsize = array_size_for_constructor (val);
4665 /* Given a non-empty initialization, this field had
4666 better be last. */
4667 gcc_assert (!fieldsize || !TREE_CHAIN (field));
4669 else if (DECL_SIZE_UNIT (field))
4671 /* ??? This can't be right. If the decl size overflows
4672 a host integer we will silently emit no data. */
4673 if (host_integerp (DECL_SIZE_UNIT (field), 1))
4674 fieldsize = tree_low_cst (DECL_SIZE_UNIT (field), 1);
4677 else
4678 fieldsize = int_size_in_bytes (TREE_TYPE (type));
4680 /* Output the element's initial value. */
4681 if (val == 0)
4682 assemble_zeros (fieldsize);
4683 else
4684 output_constant (val, fieldsize, align2);
4686 /* Count its size. */
4687 total_bytes += fieldsize;
4689 else if (val != 0 && TREE_CODE (val) != INTEGER_CST)
4690 error ("invalid initial value for member %qs",
4691 IDENTIFIER_POINTER (DECL_NAME (field)));
4692 else
4694 /* Element that is a bit-field. */
4696 HOST_WIDE_INT next_offset = int_bit_position (field);
4697 HOST_WIDE_INT end_offset
4698 = (next_offset + tree_low_cst (DECL_SIZE (field), 1));
4700 if (val == 0)
4701 val = integer_zero_node;
4703 /* If this field does not start in this (or, next) byte,
4704 skip some bytes. */
4705 if (next_offset / BITS_PER_UNIT != total_bytes)
4707 /* Output remnant of any bit field in previous bytes. */
4708 if (byte_buffer_in_use)
4710 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4711 total_bytes++;
4712 byte_buffer_in_use = 0;
4715 /* If still not at proper byte, advance to there. */
4716 if (next_offset / BITS_PER_UNIT != total_bytes)
4718 gcc_assert (next_offset / BITS_PER_UNIT >= total_bytes);
4719 assemble_zeros (next_offset / BITS_PER_UNIT - total_bytes);
4720 total_bytes = next_offset / BITS_PER_UNIT;
4724 if (! byte_buffer_in_use)
4725 byte = 0;
4727 /* We must split the element into pieces that fall within
4728 separate bytes, and combine each byte with previous or
4729 following bit-fields. */
4731 /* next_offset is the offset n fbits from the beginning of
4732 the structure to the next bit of this element to be processed.
4733 end_offset is the offset of the first bit past the end of
4734 this element. */
4735 while (next_offset < end_offset)
4737 int this_time;
4738 int shift;
4739 HOST_WIDE_INT value;
4740 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
4741 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
4743 /* Advance from byte to byte
4744 within this element when necessary. */
4745 while (next_byte != total_bytes)
4747 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4748 total_bytes++;
4749 byte = 0;
4752 /* Number of bits we can process at once
4753 (all part of the same byte). */
4754 this_time = MIN (end_offset - next_offset,
4755 BITS_PER_UNIT - next_bit);
4756 if (BYTES_BIG_ENDIAN)
4758 /* On big-endian machine, take the most significant bits
4759 first (of the bits that are significant)
4760 and put them into bytes from the most significant end. */
4761 shift = end_offset - next_offset - this_time;
4763 /* Don't try to take a bunch of bits that cross
4764 the word boundary in the INTEGER_CST. We can
4765 only select bits from the LOW or HIGH part
4766 not from both. */
4767 if (shift < HOST_BITS_PER_WIDE_INT
4768 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4770 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT;
4771 shift = HOST_BITS_PER_WIDE_INT;
4774 /* Now get the bits from the appropriate constant word. */
4775 if (shift < HOST_BITS_PER_WIDE_INT)
4776 value = TREE_INT_CST_LOW (val);
4777 else
4779 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4780 value = TREE_INT_CST_HIGH (val);
4781 shift -= HOST_BITS_PER_WIDE_INT;
4784 /* Get the result. This works only when:
4785 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4786 byte |= (((value >> shift)
4787 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4788 << (BITS_PER_UNIT - this_time - next_bit));
4790 else
4792 /* On little-endian machines,
4793 take first the least significant bits of the value
4794 and pack them starting at the least significant
4795 bits of the bytes. */
4796 shift = next_offset - int_bit_position (field);
4798 /* Don't try to take a bunch of bits that cross
4799 the word boundary in the INTEGER_CST. We can
4800 only select bits from the LOW or HIGH part
4801 not from both. */
4802 if (shift < HOST_BITS_PER_WIDE_INT
4803 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4804 this_time = (HOST_BITS_PER_WIDE_INT - shift);
4806 /* Now get the bits from the appropriate constant word. */
4807 if (shift < HOST_BITS_PER_WIDE_INT)
4808 value = TREE_INT_CST_LOW (val);
4809 else
4811 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4812 value = TREE_INT_CST_HIGH (val);
4813 shift -= HOST_BITS_PER_WIDE_INT;
4816 /* Get the result. This works only when:
4817 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4818 byte |= (((value >> shift)
4819 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4820 << next_bit);
4823 next_offset += this_time;
4824 byte_buffer_in_use = 1;
4829 if (byte_buffer_in_use)
4831 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4832 total_bytes++;
4835 if ((unsigned HOST_WIDE_INT)total_bytes < size)
4836 assemble_zeros (size - total_bytes);
4839 /* This TREE_LIST contains any weak symbol declarations waiting
4840 to be emitted. */
4841 static GTY(()) tree weak_decls;
4843 /* Mark DECL as weak. */
4845 static void
4846 mark_weak (tree decl)
4848 DECL_WEAK (decl) = 1;
4850 if (DECL_RTL_SET_P (decl)
4851 && MEM_P (DECL_RTL (decl))
4852 && XEXP (DECL_RTL (decl), 0)
4853 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF)
4854 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1;
4857 /* Merge weak status between NEWDECL and OLDDECL. */
4859 void
4860 merge_weak (tree newdecl, tree olddecl)
4862 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl))
4864 if (DECL_WEAK (newdecl) && SUPPORTS_WEAK)
4866 tree *pwd;
4867 /* We put the NEWDECL on the weak_decls list at some point
4868 and OLDDECL as well. Keep just OLDDECL on the list. */
4869 for (pwd = &weak_decls; *pwd; pwd = &TREE_CHAIN (*pwd))
4870 if (TREE_VALUE (*pwd) == newdecl)
4872 *pwd = TREE_CHAIN (*pwd);
4873 break;
4876 return;
4879 if (DECL_WEAK (newdecl))
4881 tree wd;
4883 /* NEWDECL is weak, but OLDDECL is not. */
4885 /* If we already output the OLDDECL, we're in trouble; we can't
4886 go back and make it weak. This error cannot be caught in
4887 declare_weak because the NEWDECL and OLDDECL was not yet
4888 been merged; therefore, TREE_ASM_WRITTEN was not set. */
4889 if (TREE_ASM_WRITTEN (olddecl))
4890 error ("weak declaration of %q+D must precede definition",
4891 newdecl);
4893 /* If we've already generated rtl referencing OLDDECL, we may
4894 have done so in a way that will not function properly with
4895 a weak symbol. */
4896 else if (TREE_USED (olddecl)
4897 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl)))
4898 warning (0, "weak declaration of %q+D after first use results "
4899 "in unspecified behavior", newdecl);
4901 if (SUPPORTS_WEAK)
4903 /* We put the NEWDECL on the weak_decls list at some point.
4904 Replace it with the OLDDECL. */
4905 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd))
4906 if (TREE_VALUE (wd) == newdecl)
4908 TREE_VALUE (wd) = olddecl;
4909 break;
4911 /* We may not find the entry on the list. If NEWDECL is a
4912 weak alias, then we will have already called
4913 globalize_decl to remove the entry; in that case, we do
4914 not need to do anything. */
4917 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */
4918 mark_weak (olddecl);
4920 else
4921 /* OLDDECL was weak, but NEWDECL was not explicitly marked as
4922 weak. Just update NEWDECL to indicate that it's weak too. */
4923 mark_weak (newdecl);
4926 /* Declare DECL to be a weak symbol. */
4928 void
4929 declare_weak (tree decl)
4931 if (! TREE_PUBLIC (decl))
4932 error ("weak declaration of %q+D must be public", decl);
4933 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl))
4934 error ("weak declaration of %q+D must precede definition", decl);
4935 else if (SUPPORTS_WEAK)
4937 if (! DECL_WEAK (decl))
4938 weak_decls = tree_cons (NULL, decl, weak_decls);
4940 else
4941 warning (0, "weak declaration of %q+D not supported", decl);
4943 mark_weak (decl);
4946 static void
4947 weak_finish_1 (tree decl)
4949 #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL)
4950 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4951 #endif
4953 if (! TREE_USED (decl))
4954 return;
4956 #ifdef ASM_WEAKEN_DECL
4957 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL);
4958 #else
4959 #ifdef ASM_WEAKEN_LABEL
4960 ASM_WEAKEN_LABEL (asm_out_file, name);
4961 #else
4962 #ifdef ASM_OUTPUT_WEAK_ALIAS
4964 static bool warn_once = 0;
4965 if (! warn_once)
4967 warning (0, "only weak aliases are supported in this configuration");
4968 warn_once = 1;
4970 return;
4972 #endif
4973 #endif
4974 #endif
4977 /* This TREE_LIST contains weakref targets. */
4979 static GTY(()) tree weakref_targets;
4981 /* Forward declaration. */
4982 static tree find_decl_and_mark_needed (tree decl, tree target);
4984 /* Emit any pending weak declarations. */
4986 void
4987 weak_finish (void)
4989 tree t;
4991 for (t = weakref_targets; t; t = TREE_CHAIN (t))
4993 tree alias_decl = TREE_PURPOSE (t);
4994 tree target = ultimate_transparent_alias_target (&TREE_VALUE (t));
4996 if (! TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (alias_decl)))
4997 /* Remove alias_decl from the weak list, but leave entries for
4998 the target alone. */
4999 target = NULL_TREE;
5000 #ifndef ASM_OUTPUT_WEAKREF
5001 else if (! TREE_SYMBOL_REFERENCED (target))
5003 /* Use ASM_WEAKEN_LABEL only if ASM_WEAKEN_DECL is not
5004 defined, otherwise we and weak_finish_1 would use
5005 different macros. */
5006 # if defined ASM_WEAKEN_LABEL && ! defined ASM_WEAKEN_DECL
5007 ASM_WEAKEN_LABEL (asm_out_file, IDENTIFIER_POINTER (target));
5008 # else
5009 tree decl = find_decl_and_mark_needed (alias_decl, target);
5011 if (! decl)
5013 decl = build_decl (TREE_CODE (alias_decl), target,
5014 TREE_TYPE (alias_decl));
5016 DECL_EXTERNAL (decl) = 1;
5017 TREE_PUBLIC (decl) = 1;
5018 DECL_ARTIFICIAL (decl) = 1;
5019 TREE_NOTHROW (decl) = TREE_NOTHROW (alias_decl);
5020 TREE_USED (decl) = 1;
5023 weak_finish_1 (decl);
5024 # endif
5026 #endif
5029 tree *p;
5030 tree t2;
5032 /* Remove the alias and the target from the pending weak list
5033 so that we do not emit any .weak directives for the former,
5034 nor multiple .weak directives for the latter. */
5035 for (p = &weak_decls; (t2 = *p) ; )
5037 if (TREE_VALUE (t2) == alias_decl
5038 || target == DECL_ASSEMBLER_NAME (TREE_VALUE (t2)))
5039 *p = TREE_CHAIN (t2);
5040 else
5041 p = &TREE_CHAIN (t2);
5044 /* Remove other weakrefs to the same target, to speed things up. */
5045 for (p = &TREE_CHAIN (t); (t2 = *p) ; )
5047 if (target == ultimate_transparent_alias_target (&TREE_VALUE (t2)))
5048 *p = TREE_CHAIN (t2);
5049 else
5050 p = &TREE_CHAIN (t2);
5055 for (t = weak_decls; t; t = TREE_CHAIN (t))
5057 tree decl = TREE_VALUE (t);
5059 weak_finish_1 (decl);
5063 /* Emit the assembly bits to indicate that DECL is globally visible. */
5065 static void
5066 globalize_decl (tree decl)
5069 #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL)
5070 if (DECL_WEAK (decl))
5072 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
5073 tree *p, t;
5075 #ifdef ASM_WEAKEN_DECL
5076 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
5077 #else
5078 ASM_WEAKEN_LABEL (asm_out_file, name);
5079 #endif
5081 /* Remove this function from the pending weak list so that
5082 we do not emit multiple .weak directives for it. */
5083 for (p = &weak_decls; (t = *p) ; )
5085 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5086 *p = TREE_CHAIN (t);
5087 else
5088 p = &TREE_CHAIN (t);
5091 /* Remove weakrefs to the same target from the pending weakref
5092 list, for the same reason. */
5093 for (p = &weakref_targets; (t = *p) ; )
5095 if (DECL_ASSEMBLER_NAME (decl)
5096 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5097 *p = TREE_CHAIN (t);
5098 else
5099 p = &TREE_CHAIN (t);
5102 return;
5104 #endif
5106 targetm.asm_out.globalize_decl_name (asm_out_file, decl);
5109 /* We have to be able to tell cgraph about the needed-ness of the target
5110 of an alias. This requires that the decl have been defined. Aliases
5111 that precede their definition have to be queued for later processing. */
5113 typedef struct alias_pair GTY(())
5115 tree decl;
5116 tree target;
5117 } alias_pair;
5119 /* Define gc'd vector type. */
5120 DEF_VEC_O(alias_pair);
5121 DEF_VEC_ALLOC_O(alias_pair,gc);
5123 static GTY(()) VEC(alias_pair,gc) *alias_pairs;
5125 /* Given an assembly name, find the decl it is associated with. At the
5126 same time, mark it needed for cgraph. */
5128 static tree
5129 find_decl_and_mark_needed (tree decl, tree target)
5131 struct cgraph_node *fnode = NULL;
5132 struct varpool_node *vnode = NULL;
5134 if (TREE_CODE (decl) == FUNCTION_DECL)
5136 fnode = cgraph_node_for_asm (target);
5137 if (fnode == NULL)
5138 vnode = varpool_node_for_asm (target);
5140 else
5142 vnode = varpool_node_for_asm (target);
5143 if (vnode == NULL)
5144 fnode = cgraph_node_for_asm (target);
5147 if (fnode)
5149 /* We can't mark function nodes as used after cgraph global info
5150 is finished. This wouldn't generally be necessary, but C++
5151 virtual table thunks are introduced late in the game and
5152 might seem like they need marking, although in fact they
5153 don't. */
5154 if (! cgraph_global_info_ready)
5155 cgraph_mark_needed_node (fnode);
5156 return fnode->decl;
5158 else if (vnode)
5160 varpool_mark_needed_node (vnode);
5161 return vnode->decl;
5163 else
5164 return NULL_TREE;
5167 /* Output the assembler code for a define (equate) using ASM_OUTPUT_DEF
5168 or ASM_OUTPUT_DEF_FROM_DECLS. The function defines the symbol whose
5169 tree node is DECL to have the value of the tree node TARGET. */
5171 static void
5172 do_assemble_alias (tree decl, tree target)
5174 if (TREE_ASM_WRITTEN (decl))
5175 return;
5177 TREE_ASM_WRITTEN (decl) = 1;
5178 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;
5180 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5182 ultimate_transparent_alias_target (&target);
5184 if (!targetm.have_tls
5185 && TREE_CODE (decl) == VAR_DECL
5186 && DECL_THREAD_LOCAL_P (decl))
5188 decl = emutls_decl (decl);
5189 target = get_emutls_object_name (target);
5192 if (!TREE_SYMBOL_REFERENCED (target))
5193 weakref_targets = tree_cons (decl, target, weakref_targets);
5195 #ifdef ASM_OUTPUT_WEAKREF
5196 ASM_OUTPUT_WEAKREF (asm_out_file, decl,
5197 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5198 IDENTIFIER_POINTER (target));
5199 #else
5200 if (!SUPPORTS_WEAK)
5202 error ("%Jweakref is not supported in this configuration", decl);
5203 return;
5205 #endif
5206 return;
5209 if (!targetm.have_tls
5210 && TREE_CODE (decl) == VAR_DECL
5211 && DECL_THREAD_LOCAL_P (decl))
5213 decl = emutls_decl (decl);
5214 target = get_emutls_object_name (target);
5217 #ifdef ASM_OUTPUT_DEF
5218 /* Make name accessible from other files, if appropriate. */
5220 if (TREE_PUBLIC (decl))
5222 globalize_decl (decl);
5223 maybe_assemble_visibility (decl);
5226 # ifdef ASM_OUTPUT_DEF_FROM_DECLS
5227 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target);
5228 # else
5229 ASM_OUTPUT_DEF (asm_out_file,
5230 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5231 IDENTIFIER_POINTER (target));
5232 # endif
5233 #elif defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
5235 const char *name;
5236 tree *p, t;
5238 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5239 # ifdef ASM_WEAKEN_DECL
5240 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target));
5241 # else
5242 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
5243 # endif
5244 /* Remove this function from the pending weak list so that
5245 we do not emit multiple .weak directives for it. */
5246 for (p = &weak_decls; (t = *p) ; )
5247 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5248 *p = TREE_CHAIN (t);
5249 else
5250 p = &TREE_CHAIN (t);
5252 /* Remove weakrefs to the same target from the pending weakref
5253 list, for the same reason. */
5254 for (p = &weakref_targets; (t = *p) ; )
5256 if (DECL_ASSEMBLER_NAME (decl)
5257 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5258 *p = TREE_CHAIN (t);
5259 else
5260 p = &TREE_CHAIN (t);
5263 #endif
5266 /* First pass of completing pending aliases. Make sure that cgraph knows
5267 which symbols will be required. */
5269 void
5270 finish_aliases_1 (void)
5272 unsigned i;
5273 alias_pair *p;
5275 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
5277 tree target_decl;
5279 target_decl = find_decl_and_mark_needed (p->decl, p->target);
5280 if (target_decl == NULL)
5282 if (! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5283 error ("%q+D aliased to undefined symbol %qs",
5284 p->decl, IDENTIFIER_POINTER (p->target));
5286 else if (DECL_EXTERNAL (target_decl)
5287 && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5288 error ("%q+D aliased to external symbol %qs",
5289 p->decl, IDENTIFIER_POINTER (p->target));
5293 /* Second pass of completing pending aliases. Emit the actual assembly.
5294 This happens at the end of compilation and thus it is assured that the
5295 target symbol has been emitted. */
5297 void
5298 finish_aliases_2 (void)
5300 unsigned i;
5301 alias_pair *p;
5303 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
5304 do_assemble_alias (p->decl, p->target);
5306 VEC_truncate (alias_pair, alias_pairs, 0);
5309 /* Emit an assembler directive to make the symbol for DECL an alias to
5310 the symbol for TARGET. */
5312 void
5313 assemble_alias (tree decl, tree target)
5315 tree target_decl;
5316 bool is_weakref = false;
5318 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5320 tree alias = DECL_ASSEMBLER_NAME (decl);
5322 is_weakref = true;
5324 ultimate_transparent_alias_target (&target);
5326 if (alias == target)
5327 error ("weakref %q+D ultimately targets itself", decl);
5328 else
5330 #ifndef ASM_OUTPUT_WEAKREF
5331 IDENTIFIER_TRANSPARENT_ALIAS (alias) = 1;
5332 TREE_CHAIN (alias) = target;
5333 #endif
5335 if (TREE_PUBLIC (decl))
5336 error ("weakref %q+D must have static linkage", decl);
5338 else
5340 #if !defined (ASM_OUTPUT_DEF)
5341 # if !defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL)
5342 error ("%Jalias definitions not supported in this configuration", decl);
5343 return;
5344 # else
5345 if (!DECL_WEAK (decl))
5347 error ("%Jonly weak aliases are supported in this configuration", decl);
5348 return;
5350 # endif
5351 #endif
5354 /* We must force creation of DECL_RTL for debug info generation, even though
5355 we don't use it here. */
5356 make_decl_rtl (decl);
5357 TREE_USED (decl) = 1;
5359 /* A quirk of the initial implementation of aliases required that the user
5360 add "extern" to all of them. Which is silly, but now historical. Do
5361 note that the symbol is in fact locally defined. */
5362 if (! is_weakref)
5363 DECL_EXTERNAL (decl) = 0;
5365 /* Allow aliases to aliases. */
5366 if (TREE_CODE (decl) == FUNCTION_DECL)
5367 cgraph_node (decl)->alias = true;
5368 else
5369 varpool_node (decl)->alias = true;
5371 /* If the target has already been emitted, we don't have to queue the
5372 alias. This saves a tad of memory. */
5373 target_decl = find_decl_and_mark_needed (decl, target);
5374 if (target_decl && TREE_ASM_WRITTEN (target_decl))
5375 do_assemble_alias (decl, target);
5376 else
5378 alias_pair *p = VEC_safe_push (alias_pair, gc, alias_pairs, NULL);
5379 p->decl = decl;
5380 p->target = target;
5384 /* Emit an assembler directive to set symbol for DECL visibility to
5385 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */
5387 void
5388 default_assemble_visibility (tree decl, int vis)
5390 static const char * const visibility_types[] = {
5391 NULL, "protected", "hidden", "internal"
5394 const char *name, *type;
5396 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5397 type = visibility_types[vis];
5399 #ifdef HAVE_GAS_HIDDEN
5400 fprintf (asm_out_file, "\t.%s\t", type);
5401 assemble_name (asm_out_file, name);
5402 fprintf (asm_out_file, "\n");
5403 #else
5404 warning (OPT_Wattributes, "visibility attribute not supported "
5405 "in this configuration; ignored");
5406 #endif
5409 /* A helper function to call assemble_visibility when needed for a decl. */
5412 maybe_assemble_visibility (tree decl)
5414 enum symbol_visibility vis = DECL_VISIBILITY (decl);
5416 if (vis != VISIBILITY_DEFAULT)
5418 targetm.asm_out.visibility (decl, vis);
5419 return 1;
5421 else
5422 return 0;
5425 /* Returns 1 if the target configuration supports defining public symbols
5426 so that one of them will be chosen at link time instead of generating a
5427 multiply-defined symbol error, whether through the use of weak symbols or
5428 a target-specific mechanism for having duplicates discarded. */
5431 supports_one_only (void)
5433 if (SUPPORTS_ONE_ONLY)
5434 return 1;
5435 return SUPPORTS_WEAK;
5438 /* Set up DECL as a public symbol that can be defined in multiple
5439 translation units without generating a linker error. */
5441 void
5442 make_decl_one_only (tree decl)
5444 gcc_assert (TREE_CODE (decl) == VAR_DECL
5445 || TREE_CODE (decl) == FUNCTION_DECL);
5447 TREE_PUBLIC (decl) = 1;
5449 if (SUPPORTS_ONE_ONLY)
5451 #ifdef MAKE_DECL_ONE_ONLY
5452 MAKE_DECL_ONE_ONLY (decl);
5453 #endif
5454 DECL_ONE_ONLY (decl) = 1;
5456 else if (TREE_CODE (decl) == VAR_DECL
5457 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
5458 DECL_COMMON (decl) = 1;
5459 else
5461 gcc_assert (SUPPORTS_WEAK);
5462 DECL_WEAK (decl) = 1;
5466 void
5467 init_varasm_once (void)
5469 section_htab = htab_create_ggc (31, section_entry_hash,
5470 section_entry_eq, NULL);
5471 object_block_htab = htab_create_ggc (31, object_block_entry_hash,
5472 object_block_entry_eq, NULL);
5473 const_desc_htab = htab_create_ggc (1009, const_desc_hash,
5474 const_desc_eq, NULL);
5476 const_alias_set = new_alias_set ();
5477 shared_constant_pool = create_constant_pool ();
5479 #ifdef TEXT_SECTION_ASM_OP
5480 text_section = get_unnamed_section (SECTION_CODE, output_section_asm_op,
5481 TEXT_SECTION_ASM_OP);
5482 #endif
5484 #ifdef DATA_SECTION_ASM_OP
5485 data_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5486 DATA_SECTION_ASM_OP);
5487 #endif
5489 #ifdef SDATA_SECTION_ASM_OP
5490 sdata_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5491 SDATA_SECTION_ASM_OP);
5492 #endif
5494 #ifdef READONLY_DATA_SECTION_ASM_OP
5495 readonly_data_section = get_unnamed_section (0, output_section_asm_op,
5496 READONLY_DATA_SECTION_ASM_OP);
5497 #endif
5499 #ifdef CTORS_SECTION_ASM_OP
5500 ctors_section = get_unnamed_section (0, output_section_asm_op,
5501 CTORS_SECTION_ASM_OP);
5502 #endif
5504 #ifdef DTORS_SECTION_ASM_OP
5505 dtors_section = get_unnamed_section (0, output_section_asm_op,
5506 DTORS_SECTION_ASM_OP);
5507 #endif
5509 #ifdef BSS_SECTION_ASM_OP
5510 bss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5511 output_section_asm_op,
5512 BSS_SECTION_ASM_OP);
5513 #endif
5515 #ifdef SBSS_SECTION_ASM_OP
5516 sbss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5517 output_section_asm_op,
5518 SBSS_SECTION_ASM_OP);
5519 #endif
5521 tls_comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5522 | SECTION_COMMON, emit_tls_common);
5523 lcomm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5524 | SECTION_COMMON, emit_local);
5525 comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5526 | SECTION_COMMON, emit_common);
5528 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
5529 bss_noswitch_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS,
5530 emit_bss);
5531 #endif
5533 targetm.asm_out.init_sections ();
5535 if (readonly_data_section == NULL)
5536 readonly_data_section = text_section;
5539 enum tls_model
5540 decl_default_tls_model (const_tree decl)
5542 enum tls_model kind;
5543 bool is_local;
5545 is_local = targetm.binds_local_p (decl);
5546 if (!flag_shlib)
5548 if (is_local)
5549 kind = TLS_MODEL_LOCAL_EXEC;
5550 else
5551 kind = TLS_MODEL_INITIAL_EXEC;
5554 /* Local dynamic is inefficient when we're not combining the
5555 parts of the address. */
5556 else if (optimize && is_local)
5557 kind = TLS_MODEL_LOCAL_DYNAMIC;
5558 else
5559 kind = TLS_MODEL_GLOBAL_DYNAMIC;
5560 if (kind < flag_tls_default)
5561 kind = flag_tls_default;
5563 return kind;
5566 /* Select a set of attributes for section NAME based on the properties
5567 of DECL and whether or not RELOC indicates that DECL's initializer
5568 might contain runtime relocations.
5570 We make the section read-only and executable for a function decl,
5571 read-only for a const data decl, and writable for a non-const data decl. */
5573 unsigned int
5574 default_section_type_flags (tree decl, const char *name, int reloc)
5576 unsigned int flags;
5578 if (decl && TREE_CODE (decl) == FUNCTION_DECL)
5579 flags = SECTION_CODE;
5580 else if (decl && decl_readonly_section (decl, reloc))
5581 flags = 0;
5582 else if (current_function_decl
5583 && cfun
5584 && crtl->subsections.unlikely_text_section_name
5585 && strcmp (name, crtl->subsections.unlikely_text_section_name) == 0)
5586 flags = SECTION_CODE;
5587 else if (!decl
5588 && (!current_function_decl || !cfun)
5589 && strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
5590 flags = SECTION_CODE;
5591 else
5592 flags = SECTION_WRITE;
5594 if (decl && DECL_ONE_ONLY (decl))
5595 flags |= SECTION_LINKONCE;
5597 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
5598 flags |= SECTION_TLS | SECTION_WRITE;
5600 if (strcmp (name, ".bss") == 0
5601 || strncmp (name, ".bss.", 5) == 0
5602 || strncmp (name, ".gnu.linkonce.b.", 16) == 0
5603 || strcmp (name, ".sbss") == 0
5604 || strncmp (name, ".sbss.", 6) == 0
5605 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0)
5606 flags |= SECTION_BSS;
5608 if (strcmp (name, ".tdata") == 0
5609 || strncmp (name, ".tdata.", 7) == 0
5610 || strncmp (name, ".gnu.linkonce.td.", 17) == 0)
5611 flags |= SECTION_TLS;
5613 if (strcmp (name, ".tbss") == 0
5614 || strncmp (name, ".tbss.", 6) == 0
5615 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
5616 flags |= SECTION_TLS | SECTION_BSS;
5618 /* These three sections have special ELF types. They are neither
5619 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't
5620 want to print a section type (@progbits or @nobits). If someone
5621 is silly enough to emit code or TLS variables to one of these
5622 sections, then don't handle them specially. */
5623 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS))
5624 && (strcmp (name, ".init_array") == 0
5625 || strcmp (name, ".fini_array") == 0
5626 || strcmp (name, ".preinit_array") == 0))
5627 flags |= SECTION_NOTYPE;
5629 return flags;
5632 /* Return true if the target supports some form of global BSS,
5633 either through bss_noswitch_section, or by selecting a BSS
5634 section in TARGET_ASM_SELECT_SECTION. */
5636 bool
5637 have_global_bss_p (void)
5639 return bss_noswitch_section || targetm.have_switchable_bss_sections;
5642 /* Output assembly to switch to section NAME with attribute FLAGS.
5643 Four variants for common object file formats. */
5645 void
5646 default_no_named_section (const char *name ATTRIBUTE_UNUSED,
5647 unsigned int flags ATTRIBUTE_UNUSED,
5648 tree decl ATTRIBUTE_UNUSED)
5650 /* Some object formats don't support named sections at all. The
5651 front-end should already have flagged this as an error. */
5652 gcc_unreachable ();
5655 void
5656 default_elf_asm_named_section (const char *name, unsigned int flags,
5657 tree decl ATTRIBUTE_UNUSED)
5659 char flagchars[10], *f = flagchars;
5661 /* If we have already declared this section, we can use an
5662 abbreviated form to switch back to it -- unless this section is
5663 part of a COMDAT groups, in which case GAS requires the full
5664 declaration every time. */
5665 if (!(HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5666 && (flags & SECTION_DECLARED))
5668 fprintf (asm_out_file, "\t.section\t%s\n", name);
5669 return;
5672 if (!(flags & SECTION_DEBUG))
5673 *f++ = 'a';
5674 if (flags & SECTION_WRITE)
5675 *f++ = 'w';
5676 if (flags & SECTION_CODE)
5677 *f++ = 'x';
5678 if (flags & SECTION_SMALL)
5679 *f++ = 's';
5680 if (flags & SECTION_MERGE)
5681 *f++ = 'M';
5682 if (flags & SECTION_STRINGS)
5683 *f++ = 'S';
5684 if (flags & SECTION_TLS)
5685 *f++ = 'T';
5686 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5687 *f++ = 'G';
5688 *f = '\0';
5690 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);
5692 if (!(flags & SECTION_NOTYPE))
5694 const char *type;
5695 const char *format;
5697 if (flags & SECTION_BSS)
5698 type = "nobits";
5699 else
5700 type = "progbits";
5702 format = ",@%s";
5703 #ifdef ASM_COMMENT_START
5704 /* On platforms that use "@" as the assembly comment character,
5705 use "%" instead. */
5706 if (strcmp (ASM_COMMENT_START, "@") == 0)
5707 format = ",%%%s";
5708 #endif
5709 fprintf (asm_out_file, format, type);
5711 if (flags & SECTION_ENTSIZE)
5712 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
5713 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5714 fprintf (asm_out_file, ",%s,comdat",
5715 lang_hooks.decls.comdat_group (decl));
5718 putc ('\n', asm_out_file);
5721 void
5722 default_coff_asm_named_section (const char *name, unsigned int flags,
5723 tree decl ATTRIBUTE_UNUSED)
5725 char flagchars[8], *f = flagchars;
5727 if (flags & SECTION_WRITE)
5728 *f++ = 'w';
5729 if (flags & SECTION_CODE)
5730 *f++ = 'x';
5731 *f = '\0';
5733 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);
5736 void
5737 default_pe_asm_named_section (const char *name, unsigned int flags,
5738 tree decl)
5740 default_coff_asm_named_section (name, flags, decl);
5742 if (flags & SECTION_LINKONCE)
5744 /* Functions may have been compiled at various levels of
5745 optimization so we can't use `same_size' here.
5746 Instead, have the linker pick one. */
5747 fprintf (asm_out_file, "\t.linkonce %s\n",
5748 (flags & SECTION_CODE ? "discard" : "same_size"));
5752 /* The lame default section selector. */
5754 section *
5755 default_select_section (tree decl, int reloc,
5756 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
5758 if (DECL_P (decl))
5760 if (decl_readonly_section (decl, reloc))
5761 return readonly_data_section;
5763 else if (TREE_CODE (decl) == CONSTRUCTOR)
5765 if (! ((flag_pic && reloc)
5766 || !TREE_READONLY (decl)
5767 || TREE_SIDE_EFFECTS (decl)
5768 || !TREE_CONSTANT (decl)))
5769 return readonly_data_section;
5771 else if (TREE_CODE (decl) == STRING_CST)
5772 return readonly_data_section;
5773 else if (! (flag_pic && reloc))
5774 return readonly_data_section;
5776 return data_section;
5779 enum section_category
5780 categorize_decl_for_section (const_tree decl, int reloc)
5782 enum section_category ret;
5784 if (TREE_CODE (decl) == FUNCTION_DECL)
5785 return SECCAT_TEXT;
5786 else if (TREE_CODE (decl) == STRING_CST)
5788 if (flag_mudflap) /* or !flag_merge_constants */
5789 return SECCAT_RODATA;
5790 else
5791 return SECCAT_RODATA_MERGE_STR;
5793 else if (TREE_CODE (decl) == VAR_DECL)
5795 if (bss_initializer_p (decl))
5796 ret = SECCAT_BSS;
5797 else if (! TREE_READONLY (decl)
5798 || TREE_SIDE_EFFECTS (decl)
5799 || ! TREE_CONSTANT (DECL_INITIAL (decl)))
5801 /* Here the reloc_rw_mask is not testing whether the section should
5802 be read-only or not, but whether the dynamic link will have to
5803 do something. If so, we wish to segregate the data in order to
5804 minimize cache misses inside the dynamic linker. */
5805 if (reloc & targetm.asm_out.reloc_rw_mask ())
5806 ret = reloc == 1 ? SECCAT_DATA_REL_LOCAL : SECCAT_DATA_REL;
5807 else
5808 ret = SECCAT_DATA;
5810 else if (reloc & targetm.asm_out.reloc_rw_mask ())
5811 ret = reloc == 1 ? SECCAT_DATA_REL_RO_LOCAL : SECCAT_DATA_REL_RO;
5812 else if (reloc || flag_merge_constants < 2)
5813 /* C and C++ don't allow different variables to share the same
5814 location. -fmerge-all-constants allows even that (at the
5815 expense of not conforming). */
5816 ret = SECCAT_RODATA;
5817 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST)
5818 ret = SECCAT_RODATA_MERGE_STR_INIT;
5819 else
5820 ret = SECCAT_RODATA_MERGE_CONST;
5822 else if (TREE_CODE (decl) == CONSTRUCTOR)
5824 if ((reloc & targetm.asm_out.reloc_rw_mask ())
5825 || TREE_SIDE_EFFECTS (decl)
5826 || ! TREE_CONSTANT (decl))
5827 ret = SECCAT_DATA;
5828 else
5829 ret = SECCAT_RODATA;
5831 else
5832 ret = SECCAT_RODATA;
5834 /* There are no read-only thread-local sections. */
5835 if (TREE_CODE (decl) == VAR_DECL && DECL_TLS_MODEL (decl))
5837 if (DECL_TLS_MODEL (decl) == TLS_MODEL_EMULATED)
5839 if (DECL_EMUTLS_VAR_P (decl))
5841 if (targetm.emutls.var_section)
5842 ret = SECCAT_EMUTLS_VAR;
5844 else
5846 if (targetm.emutls.tmpl_prefix)
5847 ret = SECCAT_EMUTLS_TMPL;
5850 /* Note that this would be *just* SECCAT_BSS, except that there's
5851 no concept of a read-only thread-local-data section. */
5852 else if (ret == SECCAT_BSS
5853 || (flag_zero_initialized_in_bss
5854 && initializer_zerop (DECL_INITIAL (decl))))
5855 ret = SECCAT_TBSS;
5856 else
5857 ret = SECCAT_TDATA;
5860 /* If the target uses small data sections, select it. */
5861 else if (targetm.in_small_data_p (decl))
5863 if (ret == SECCAT_BSS)
5864 ret = SECCAT_SBSS;
5865 else if (targetm.have_srodata_section && ret == SECCAT_RODATA)
5866 ret = SECCAT_SRODATA;
5867 else
5868 ret = SECCAT_SDATA;
5871 return ret;
5874 bool
5875 decl_readonly_section (const_tree decl, int reloc)
5877 switch (categorize_decl_for_section (decl, reloc))
5879 case SECCAT_RODATA:
5880 case SECCAT_RODATA_MERGE_STR:
5881 case SECCAT_RODATA_MERGE_STR_INIT:
5882 case SECCAT_RODATA_MERGE_CONST:
5883 case SECCAT_SRODATA:
5884 return true;
5885 break;
5886 default:
5887 return false;
5888 break;
5892 /* Select a section based on the above categorization. */
5894 section *
5895 default_elf_select_section (tree decl, int reloc,
5896 unsigned HOST_WIDE_INT align)
5898 const char *sname;
5899 switch (categorize_decl_for_section (decl, reloc))
5901 case SECCAT_TEXT:
5902 /* We're not supposed to be called on FUNCTION_DECLs. */
5903 gcc_unreachable ();
5904 case SECCAT_RODATA:
5905 return readonly_data_section;
5906 case SECCAT_RODATA_MERGE_STR:
5907 return mergeable_string_section (decl, align, 0);
5908 case SECCAT_RODATA_MERGE_STR_INIT:
5909 return mergeable_string_section (DECL_INITIAL (decl), align, 0);
5910 case SECCAT_RODATA_MERGE_CONST:
5911 return mergeable_constant_section (DECL_MODE (decl), align, 0);
5912 case SECCAT_SRODATA:
5913 sname = ".sdata2";
5914 break;
5915 case SECCAT_DATA:
5916 return data_section;
5917 case SECCAT_DATA_REL:
5918 sname = ".data.rel";
5919 break;
5920 case SECCAT_DATA_REL_LOCAL:
5921 sname = ".data.rel.local";
5922 break;
5923 case SECCAT_DATA_REL_RO:
5924 sname = ".data.rel.ro";
5925 break;
5926 case SECCAT_DATA_REL_RO_LOCAL:
5927 sname = ".data.rel.ro.local";
5928 break;
5929 case SECCAT_SDATA:
5930 sname = ".sdata";
5931 break;
5932 case SECCAT_TDATA:
5933 sname = ".tdata";
5934 break;
5935 case SECCAT_BSS:
5936 if (bss_section)
5937 return bss_section;
5938 sname = ".bss";
5939 break;
5940 case SECCAT_SBSS:
5941 sname = ".sbss";
5942 break;
5943 case SECCAT_TBSS:
5944 sname = ".tbss";
5945 break;
5946 case SECCAT_EMUTLS_VAR:
5947 sname = targetm.emutls.var_section;
5948 break;
5949 case SECCAT_EMUTLS_TMPL:
5950 sname = targetm.emutls.tmpl_section;
5951 break;
5952 default:
5953 gcc_unreachable ();
5956 if (!DECL_P (decl))
5957 decl = NULL_TREE;
5958 return get_named_section (decl, sname, reloc);
5961 /* Construct a unique section name based on the decl name and the
5962 categorization performed above. */
5964 void
5965 default_unique_section (tree decl, int reloc)
5967 /* We only need to use .gnu.linkonce if we don't have COMDAT groups. */
5968 bool one_only = DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP;
5969 const char *prefix, *name, *linkonce;
5970 char *string;
5972 switch (categorize_decl_for_section (decl, reloc))
5974 case SECCAT_TEXT:
5975 prefix = one_only ? ".t" : ".text";
5976 break;
5977 case SECCAT_RODATA:
5978 case SECCAT_RODATA_MERGE_STR:
5979 case SECCAT_RODATA_MERGE_STR_INIT:
5980 case SECCAT_RODATA_MERGE_CONST:
5981 prefix = one_only ? ".r" : ".rodata";
5982 break;
5983 case SECCAT_SRODATA:
5984 prefix = one_only ? ".s2" : ".sdata2";
5985 break;
5986 case SECCAT_DATA:
5987 prefix = one_only ? ".d" : ".data";
5988 break;
5989 case SECCAT_DATA_REL:
5990 prefix = one_only ? ".d.rel" : ".data.rel";
5991 break;
5992 case SECCAT_DATA_REL_LOCAL:
5993 prefix = one_only ? ".d.rel.local" : ".data.rel.local";
5994 break;
5995 case SECCAT_DATA_REL_RO:
5996 prefix = one_only ? ".d.rel.ro" : ".data.rel.ro";
5997 break;
5998 case SECCAT_DATA_REL_RO_LOCAL:
5999 prefix = one_only ? ".d.rel.ro.local" : ".data.rel.ro.local";
6000 break;
6001 case SECCAT_SDATA:
6002 prefix = one_only ? ".s" : ".sdata";
6003 break;
6004 case SECCAT_BSS:
6005 prefix = one_only ? ".b" : ".bss";
6006 break;
6007 case SECCAT_SBSS:
6008 prefix = one_only ? ".sb" : ".sbss";
6009 break;
6010 case SECCAT_TDATA:
6011 prefix = one_only ? ".td" : ".tdata";
6012 break;
6013 case SECCAT_TBSS:
6014 prefix = one_only ? ".tb" : ".tbss";
6015 break;
6016 case SECCAT_EMUTLS_VAR:
6017 prefix = targetm.emutls.var_section;
6018 break;
6019 case SECCAT_EMUTLS_TMPL:
6020 prefix = targetm.emutls.tmpl_section;
6021 break;
6022 default:
6023 gcc_unreachable ();
6026 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
6027 name = targetm.strip_name_encoding (name);
6029 /* If we're using one_only, then there needs to be a .gnu.linkonce
6030 prefix to the section name. */
6031 linkonce = one_only ? ".gnu.linkonce" : "";
6033 string = ACONCAT ((linkonce, prefix, ".", name, NULL));
6035 DECL_SECTION_NAME (decl) = build_string (strlen (string), string);
6038 /* Like compute_reloc_for_constant, except for an RTX. The return value
6039 is a mask for which bit 1 indicates a global relocation, and bit 0
6040 indicates a local relocation. */
6042 static int
6043 compute_reloc_for_rtx_1 (rtx *xp, void *data)
6045 int *preloc = data;
6046 rtx x = *xp;
6048 switch (GET_CODE (x))
6050 case SYMBOL_REF:
6051 *preloc |= SYMBOL_REF_LOCAL_P (x) ? 1 : 2;
6052 break;
6053 case LABEL_REF:
6054 *preloc |= 1;
6055 break;
6056 default:
6057 break;
6060 return 0;
6063 static int
6064 compute_reloc_for_rtx (rtx x)
6066 int reloc;
6068 switch (GET_CODE (x))
6070 case CONST:
6071 case SYMBOL_REF:
6072 case LABEL_REF:
6073 reloc = 0;
6074 for_each_rtx (&x, compute_reloc_for_rtx_1, &reloc);
6075 return reloc;
6077 default:
6078 return 0;
6082 section *
6083 default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED,
6084 rtx x,
6085 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
6087 if (compute_reloc_for_rtx (x) & targetm.asm_out.reloc_rw_mask ())
6088 return data_section;
6089 else
6090 return readonly_data_section;
6093 section *
6094 default_elf_select_rtx_section (enum machine_mode mode, rtx x,
6095 unsigned HOST_WIDE_INT align)
6097 int reloc = compute_reloc_for_rtx (x);
6099 /* ??? Handle small data here somehow. */
6101 if (reloc & targetm.asm_out.reloc_rw_mask ())
6103 if (reloc == 1)
6104 return get_named_section (NULL, ".data.rel.ro.local", 1);
6105 else
6106 return get_named_section (NULL, ".data.rel.ro", 3);
6109 return mergeable_constant_section (mode, align, 0);
6112 /* Set the generally applicable flags on the SYMBOL_REF for EXP. */
6114 void
6115 default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
6117 rtx symbol;
6118 int flags;
6120 /* Careful not to prod global register variables. */
6121 if (!MEM_P (rtl))
6122 return;
6123 symbol = XEXP (rtl, 0);
6124 if (GET_CODE (symbol) != SYMBOL_REF)
6125 return;
6127 flags = SYMBOL_REF_FLAGS (symbol) & SYMBOL_FLAG_HAS_BLOCK_INFO;
6128 if (TREE_CODE (decl) == FUNCTION_DECL)
6129 flags |= SYMBOL_FLAG_FUNCTION;
6130 if (targetm.binds_local_p (decl))
6131 flags |= SYMBOL_FLAG_LOCAL;
6132 if (targetm.have_tls && TREE_CODE (decl) == VAR_DECL
6133 && DECL_THREAD_LOCAL_P (decl))
6134 flags |= DECL_TLS_MODEL (decl) << SYMBOL_FLAG_TLS_SHIFT;
6135 else if (targetm.in_small_data_p (decl))
6136 flags |= SYMBOL_FLAG_SMALL;
6137 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without
6138 being PUBLIC, the thing *must* be defined in this translation unit.
6139 Prevent this buglet from being propagated into rtl code as well. */
6140 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
6141 flags |= SYMBOL_FLAG_EXTERNAL;
6143 SYMBOL_REF_FLAGS (symbol) = flags;
6146 /* By default, we do nothing for encode_section_info, so we need not
6147 do anything but discard the '*' marker. */
6149 const char *
6150 default_strip_name_encoding (const char *str)
6152 return str + (*str == '*');
6155 #ifdef ASM_OUTPUT_DEF
6156 /* The default implementation of TARGET_ASM_OUTPUT_ANCHOR. Define the
6157 anchor relative to ".", the current section position. */
6159 void
6160 default_asm_output_anchor (rtx symbol)
6162 char buffer[100];
6164 sprintf (buffer, "*. + " HOST_WIDE_INT_PRINT_DEC,
6165 SYMBOL_REF_BLOCK_OFFSET (symbol));
6166 ASM_OUTPUT_DEF (asm_out_file, XSTR (symbol, 0), buffer);
6168 #endif
6170 /* The default implementation of TARGET_USE_ANCHORS_FOR_SYMBOL_P. */
6172 bool
6173 default_use_anchors_for_symbol_p (const_rtx symbol)
6175 section *sect;
6176 tree decl;
6178 /* Don't use anchors for mergeable sections. The linker might move
6179 the objects around. */
6180 sect = SYMBOL_REF_BLOCK (symbol)->sect;
6181 if (sect->common.flags & SECTION_MERGE)
6182 return false;
6184 /* Don't use anchors for small data sections. The small data register
6185 acts as an anchor for such sections. */
6186 if (sect->common.flags & SECTION_SMALL)
6187 return false;
6189 decl = SYMBOL_REF_DECL (symbol);
6190 if (decl && DECL_P (decl))
6192 /* Don't use section anchors for decls that might be defined by
6193 other modules. */
6194 if (!targetm.binds_local_p (decl))
6195 return false;
6197 /* Don't use section anchors for decls that will be placed in a
6198 small data section. */
6199 /* ??? Ideally, this check would be redundant with the SECTION_SMALL
6200 one above. The problem is that we only use SECTION_SMALL for
6201 sections that should be marked as small in the section directive. */
6202 if (targetm.in_small_data_p (decl))
6203 return false;
6205 return true;
6208 /* Assume ELF-ish defaults, since that's pretty much the most liberal
6209 wrt cross-module name binding. */
6211 bool
6212 default_binds_local_p (const_tree exp)
6214 return default_binds_local_p_1 (exp, flag_shlib);
6217 bool
6218 default_binds_local_p_1 (const_tree exp, int shlib)
6220 bool local_p;
6222 /* A non-decl is an entry in the constant pool. */
6223 if (!DECL_P (exp))
6224 local_p = true;
6225 /* Weakrefs may not bind locally, even though the weakref itself is
6226 always static and therefore local. */
6227 else if (lookup_attribute ("weakref", DECL_ATTRIBUTES (exp)))
6228 local_p = false;
6229 /* Static variables are always local. */
6230 else if (! TREE_PUBLIC (exp))
6231 local_p = true;
6232 /* A variable is local if the user has said explicitly that it will
6233 be. */
6234 else if (DECL_VISIBILITY_SPECIFIED (exp)
6235 && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6236 local_p = true;
6237 /* Variables defined outside this object might not be local. */
6238 else if (DECL_EXTERNAL (exp))
6239 local_p = false;
6240 /* If defined in this object and visibility is not default, must be
6241 local. */
6242 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6243 local_p = true;
6244 /* Default visibility weak data can be overridden by a strong symbol
6245 in another module and so are not local. */
6246 else if (DECL_WEAK (exp))
6247 local_p = false;
6248 /* If PIC, then assume that any global name can be overridden by
6249 symbols resolved from other modules, unless we are compiling with
6250 -fwhole-program, which assumes that names are local. */
6251 else if (shlib)
6252 local_p = flag_whole_program;
6253 /* Uninitialized COMMON variable may be unified with symbols
6254 resolved from other modules. */
6255 else if (DECL_COMMON (exp)
6256 && (DECL_INITIAL (exp) == NULL
6257 || DECL_INITIAL (exp) == error_mark_node))
6258 local_p = false;
6259 /* Otherwise we're left with initialized (or non-common) global data
6260 which is of necessity defined locally. */
6261 else
6262 local_p = true;
6264 return local_p;
6267 /* Determine whether or not a pointer mode is valid. Assume defaults
6268 of ptr_mode or Pmode - can be overridden. */
6269 bool
6270 default_valid_pointer_mode (enum machine_mode mode)
6272 return (mode == ptr_mode || mode == Pmode);
6275 /* Default function to output code that will globalize a label. A
6276 target must define GLOBAL_ASM_OP or provide its own function to
6277 globalize a label. */
6278 #ifdef GLOBAL_ASM_OP
6279 void
6280 default_globalize_label (FILE * stream, const char *name)
6282 fputs (GLOBAL_ASM_OP, stream);
6283 assemble_name (stream, name);
6284 putc ('\n', stream);
6286 #endif /* GLOBAL_ASM_OP */
6288 /* Default function to output code that will globalize a declaration. */
6289 void
6290 default_globalize_decl_name (FILE * stream, tree decl)
6292 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
6293 targetm.asm_out.globalize_label (stream, name);
6296 /* Default function to output a label for unwind information. The
6297 default is to do nothing. A target that needs nonlocal labels for
6298 unwind information must provide its own function to do this. */
6299 void
6300 default_emit_unwind_label (FILE * stream ATTRIBUTE_UNUSED,
6301 tree decl ATTRIBUTE_UNUSED,
6302 int for_eh ATTRIBUTE_UNUSED,
6303 int empty ATTRIBUTE_UNUSED)
6307 /* Default function to output a label to divide up the exception table.
6308 The default is to do nothing. A target that needs/wants to divide
6309 up the table must provide it's own function to do this. */
6310 void
6311 default_emit_except_table_label (FILE * stream ATTRIBUTE_UNUSED)
6315 /* This is how to output an internal numbered label where PREFIX is
6316 the class of label and LABELNO is the number within the class. */
6318 void
6319 default_internal_label (FILE *stream, const char *prefix,
6320 unsigned long labelno)
6322 char *const buf = alloca (40 + strlen (prefix));
6323 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
6324 ASM_OUTPUT_INTERNAL_LABEL (stream, buf);
6327 /* This is the default behavior at the beginning of a file. It's
6328 controlled by two other target-hook toggles. */
6329 void
6330 default_file_start (void)
6332 if (targetm.file_start_app_off && !flag_verbose_asm)
6333 fputs (ASM_APP_OFF, asm_out_file);
6335 if (targetm.file_start_file_directive)
6336 output_file_directive (asm_out_file, main_input_filename);
6339 /* This is a generic routine suitable for use as TARGET_ASM_FILE_END
6340 which emits a special section directive used to indicate whether or
6341 not this object file needs an executable stack. This is primarily
6342 a GNU extension to ELF but could be used on other targets. */
6344 int trampolines_created;
6346 void
6347 file_end_indicate_exec_stack (void)
6349 unsigned int flags = SECTION_DEBUG;
6350 if (trampolines_created)
6351 flags |= SECTION_CODE;
6353 switch_to_section (get_section (".note.GNU-stack", flags, NULL));
6356 /* Output DIRECTIVE (a C string) followed by a newline. This is used as
6357 a get_unnamed_section callback. */
6359 void
6360 output_section_asm_op (const void *directive)
6362 fprintf (asm_out_file, "%s\n", (const char *) directive);
6365 /* Emit assembly code to switch to section NEW_SECTION. Do nothing if
6366 the current section is NEW_SECTION. */
6368 void
6369 switch_to_section (section *new_section)
6371 if (in_section == new_section)
6372 return;
6374 if (new_section->common.flags & SECTION_FORGET)
6375 in_section = NULL;
6376 else
6377 in_section = new_section;
6379 switch (SECTION_STYLE (new_section))
6381 case SECTION_NAMED:
6382 if (cfun
6383 && !crtl->subsections.unlikely_text_section_name
6384 && strcmp (new_section->named.name,
6385 UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
6386 crtl->subsections.unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
6388 targetm.asm_out.named_section (new_section->named.name,
6389 new_section->named.common.flags,
6390 new_section->named.decl);
6391 break;
6393 case SECTION_UNNAMED:
6394 new_section->unnamed.callback (new_section->unnamed.data);
6395 break;
6397 case SECTION_NOSWITCH:
6398 gcc_unreachable ();
6399 break;
6402 new_section->common.flags |= SECTION_DECLARED;
6405 /* If block symbol SYMBOL has not yet been assigned an offset, place
6406 it at the end of its block. */
6408 void
6409 place_block_symbol (rtx symbol)
6411 unsigned HOST_WIDE_INT size, mask, offset;
6412 struct constant_descriptor_rtx *desc;
6413 unsigned int alignment;
6414 struct object_block *block;
6415 tree decl;
6417 gcc_assert (SYMBOL_REF_BLOCK (symbol));
6418 if (SYMBOL_REF_BLOCK_OFFSET (symbol) >= 0)
6419 return;
6421 /* Work out the symbol's size and alignment. */
6422 if (CONSTANT_POOL_ADDRESS_P (symbol))
6424 desc = SYMBOL_REF_CONSTANT (symbol);
6425 alignment = desc->align;
6426 size = GET_MODE_SIZE (desc->mode);
6428 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6430 decl = SYMBOL_REF_DECL (symbol);
6431 alignment = get_constant_alignment (decl);
6432 size = get_constant_size (decl);
6434 else
6436 decl = SYMBOL_REF_DECL (symbol);
6437 alignment = DECL_ALIGN (decl);
6438 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6441 /* Calculate the object's offset from the start of the block. */
6442 block = SYMBOL_REF_BLOCK (symbol);
6443 mask = alignment / BITS_PER_UNIT - 1;
6444 offset = (block->size + mask) & ~mask;
6445 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
6447 /* Record the block's new alignment and size. */
6448 block->alignment = MAX (block->alignment, alignment);
6449 block->size = offset + size;
6451 VEC_safe_push (rtx, gc, block->objects, symbol);
6454 /* Return the anchor that should be used to address byte offset OFFSET
6455 from the first object in BLOCK. MODEL is the TLS model used
6456 to access it. */
6459 get_section_anchor (struct object_block *block, HOST_WIDE_INT offset,
6460 enum tls_model model)
6462 char label[100];
6463 unsigned int begin, middle, end;
6464 unsigned HOST_WIDE_INT min_offset, max_offset, range, bias, delta;
6465 rtx anchor;
6467 /* Work out the anchor's offset. Use an offset of 0 for the first
6468 anchor so that we don't pessimize the case where we take the address
6469 of a variable at the beginning of the block. This is particularly
6470 useful when a block has only one variable assigned to it.
6472 We try to place anchors RANGE bytes apart, so there can then be
6473 anchors at +/-RANGE, +/-2 * RANGE, and so on, up to the limits of
6474 a ptr_mode offset. With some target settings, the lowest such
6475 anchor might be out of range for the lowest ptr_mode offset;
6476 likewise the highest anchor for the highest offset. Use anchors
6477 at the extreme ends of the ptr_mode range in such cases.
6479 All arithmetic uses unsigned integers in order to avoid
6480 signed overflow. */
6481 max_offset = (unsigned HOST_WIDE_INT) targetm.max_anchor_offset;
6482 min_offset = (unsigned HOST_WIDE_INT) targetm.min_anchor_offset;
6483 range = max_offset - min_offset + 1;
6484 if (range == 0)
6485 offset = 0;
6486 else
6488 bias = 1 << (GET_MODE_BITSIZE (ptr_mode) - 1);
6489 if (offset < 0)
6491 delta = -(unsigned HOST_WIDE_INT) offset + max_offset;
6492 delta -= delta % range;
6493 if (delta > bias)
6494 delta = bias;
6495 offset = (HOST_WIDE_INT) (-delta);
6497 else
6499 delta = (unsigned HOST_WIDE_INT) offset - min_offset;
6500 delta -= delta % range;
6501 if (delta > bias - 1)
6502 delta = bias - 1;
6503 offset = (HOST_WIDE_INT) delta;
6507 /* Do a binary search to see if there's already an anchor we can use.
6508 Set BEGIN to the new anchor's index if not. */
6509 begin = 0;
6510 end = VEC_length (rtx, block->anchors);
6511 while (begin != end)
6513 middle = (end + begin) / 2;
6514 anchor = VEC_index (rtx, block->anchors, middle);
6515 if (SYMBOL_REF_BLOCK_OFFSET (anchor) > offset)
6516 end = middle;
6517 else if (SYMBOL_REF_BLOCK_OFFSET (anchor) < offset)
6518 begin = middle + 1;
6519 else if (SYMBOL_REF_TLS_MODEL (anchor) > model)
6520 end = middle;
6521 else if (SYMBOL_REF_TLS_MODEL (anchor) < model)
6522 begin = middle + 1;
6523 else
6524 return anchor;
6527 /* Create a new anchor with a unique label. */
6528 ASM_GENERATE_INTERNAL_LABEL (label, "LANCHOR", anchor_labelno++);
6529 anchor = create_block_symbol (ggc_strdup (label), block, offset);
6530 SYMBOL_REF_FLAGS (anchor) |= SYMBOL_FLAG_LOCAL | SYMBOL_FLAG_ANCHOR;
6531 SYMBOL_REF_FLAGS (anchor) |= model << SYMBOL_FLAG_TLS_SHIFT;
6533 /* Insert it at index BEGIN. */
6534 VEC_safe_insert (rtx, gc, block->anchors, begin, anchor);
6535 return anchor;
6538 /* Output the objects in BLOCK. */
6540 static void
6541 output_object_block (struct object_block *block)
6543 struct constant_descriptor_rtx *desc;
6544 unsigned int i;
6545 HOST_WIDE_INT offset;
6546 tree decl;
6547 rtx symbol;
6549 if (block->objects == NULL)
6550 return;
6552 /* Switch to the section and make sure that the first byte is
6553 suitably aligned. */
6554 switch_to_section (block->sect);
6555 assemble_align (block->alignment);
6557 /* Define the values of all anchors relative to the current section
6558 position. */
6559 for (i = 0; VEC_iterate (rtx, block->anchors, i, symbol); i++)
6560 targetm.asm_out.output_anchor (symbol);
6562 /* Output the objects themselves. */
6563 offset = 0;
6564 for (i = 0; VEC_iterate (rtx, block->objects, i, symbol); i++)
6566 /* Move to the object's offset, padding with zeros if necessary. */
6567 assemble_zeros (SYMBOL_REF_BLOCK_OFFSET (symbol) - offset);
6568 offset = SYMBOL_REF_BLOCK_OFFSET (symbol);
6569 if (CONSTANT_POOL_ADDRESS_P (symbol))
6571 desc = SYMBOL_REF_CONSTANT (symbol);
6572 output_constant_pool_1 (desc, 1);
6573 offset += GET_MODE_SIZE (desc->mode);
6575 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6577 decl = SYMBOL_REF_DECL (symbol);
6578 assemble_constant_contents (decl, XSTR (symbol, 0),
6579 get_constant_alignment (decl));
6580 offset += get_constant_size (decl);
6582 else
6584 decl = SYMBOL_REF_DECL (symbol);
6585 assemble_variable_contents (decl, XSTR (symbol, 0), false);
6586 offset += tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6591 /* A htab_traverse callback used to call output_object_block for
6592 each member of object_block_htab. */
6594 static int
6595 output_object_block_htab (void **slot, void *data ATTRIBUTE_UNUSED)
6597 output_object_block ((struct object_block *) (*slot));
6598 return 1;
6601 /* Output the definitions of all object_blocks. */
6603 void
6604 output_object_blocks (void)
6606 htab_traverse (object_block_htab, output_object_block_htab, NULL);
6609 /* This function provides a possible implementation of the
6610 TARGET_ASM_RECORD_GCC_SWITCHES target hook for ELF targets. When triggered
6611 by -frecord-gcc-switches it creates a new mergeable, string section in the
6612 assembler output file called TARGET_ASM_RECORD_GCC_SWITCHES_SECTION which
6613 contains the switches in ASCII format.
6615 FIXME: This code does not correctly handle double quote characters
6616 that appear inside strings, (it strips them rather than preserving them).
6617 FIXME: ASM_OUTPUT_ASCII, as defined in config/elfos.h will not emit NUL
6618 characters - instead it treats them as sub-string separators. Since
6619 we want to emit NUL strings terminators into the object file we have to use
6620 ASM_OUTPUT_SKIP. */
6623 elf_record_gcc_switches (print_switch_type type, const char * name)
6625 static char buffer[1024];
6627 /* This variable is used as part of a simplistic heuristic to detect
6628 command line switches which take an argument:
6630 "If a command line option does not start with a dash then
6631 it is an argument for the previous command line option."
6633 This fails in the case of the command line option which is the name
6634 of the file to compile, but otherwise it is pretty reasonable. */
6635 static bool previous_name_held_back = FALSE;
6637 switch (type)
6639 case SWITCH_TYPE_PASSED:
6640 if (* name != '-')
6642 if (previous_name_held_back)
6644 unsigned int len = strlen (buffer);
6646 snprintf (buffer + len, sizeof buffer - len, " %s", name);
6647 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6648 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6649 previous_name_held_back = FALSE;
6651 else
6653 strncpy (buffer, name, sizeof buffer);
6654 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6655 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6658 else
6660 if (previous_name_held_back)
6662 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6663 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6666 strncpy (buffer, name, sizeof buffer);
6667 previous_name_held_back = TRUE;
6669 break;
6671 case SWITCH_TYPE_DESCRIPTIVE:
6672 if (name == NULL)
6674 /* Distinguish between invocations where name is NULL. */
6675 static bool started = false;
6677 if (started)
6679 if (previous_name_held_back)
6681 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6682 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6685 else
6687 section * sec;
6689 sec = get_section (targetm.asm_out.record_gcc_switches_section,
6690 SECTION_DEBUG
6691 | SECTION_MERGE
6692 | SECTION_STRINGS
6693 | (SECTION_ENTSIZE & 1),
6694 NULL);
6695 switch_to_section (sec);
6696 started = true;
6700 default:
6701 break;
6704 /* The return value is currently ignored by the caller, but must be 0.
6705 For -fverbose-asm the return value would be the number of characters
6706 emitted into the assembler file. */
6707 return 0;
6710 /* Emit text to declare externally defined symbols. It is needed to
6711 properly support non-default visibility. */
6712 void
6713 default_elf_asm_output_external (FILE *file ATTRIBUTE_UNUSED,
6714 tree decl,
6715 const char *name ATTRIBUTE_UNUSED)
6717 /* We output the name if and only if TREE_SYMBOL_REFERENCED is
6718 set in order to avoid putting out names that are never really
6719 used. */
6720 if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))
6721 && targetm.binds_local_p (decl))
6722 maybe_assemble_visibility (decl);
6725 #include "gt-varasm.h"