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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, 2008, 2009
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 "ggc.h"
46 #include "langhooks.h"
47 #include "tm_p.h"
48 #include "debug.h"
49 #include "target.h"
50 #include "targhooks.h"
51 #include "tree-mudflap.h"
52 #include "cgraph.h"
53 #include "cfglayout.h"
54 #include "basic-block.h"
55 #include "tree-iterator.h"
57 #ifdef XCOFF_DEBUGGING_INFO
58 #include "xcoffout.h" /* Needed for external data
59 declarations for e.g. AIX 4.x. */
60 #endif
62 /* The (assembler) name of the first globally-visible object output. */
63 extern GTY(()) const char *first_global_object_name;
64 extern GTY(()) const char *weak_global_object_name;
66 const char *first_global_object_name;
67 const char *weak_global_object_name;
69 struct addr_const;
70 struct constant_descriptor_rtx;
71 struct rtx_constant_pool;
73 #define n_deferred_constants (crtl->varasm.deferred_constants)
75 /* Number for making the label on the next
76 constant that is stored in memory. */
78 static GTY(()) int const_labelno;
80 /* Carry information from ASM_DECLARE_OBJECT_NAME
81 to ASM_FINISH_DECLARE_OBJECT. */
83 int size_directive_output;
85 /* The last decl for which assemble_variable was called,
86 if it did ASM_DECLARE_OBJECT_NAME.
87 If the last call to assemble_variable didn't do that,
88 this holds 0. */
90 tree last_assemble_variable_decl;
92 /* The following global variable indicates if the first basic block
93 in a function belongs to the cold partition or not. */
95 bool first_function_block_is_cold;
97 /* We give all constants their own alias set. Perhaps redundant with
98 MEM_READONLY_P, but pre-dates it. */
100 static alias_set_type const_alias_set;
102 static const char *strip_reg_name (const char *);
103 static int contains_pointers_p (tree);
104 #ifdef ASM_OUTPUT_EXTERNAL
105 static bool incorporeal_function_p (tree);
106 #endif
107 static void decode_addr_const (tree, struct addr_const *);
108 static hashval_t const_desc_hash (const void *);
109 static int const_desc_eq (const void *, const void *);
110 static hashval_t const_hash_1 (const tree);
111 static int compare_constant (const tree, const tree);
112 static tree copy_constant (tree);
113 static void output_constant_def_contents (rtx);
114 static void output_addressed_constants (tree);
115 static unsigned HOST_WIDE_INT array_size_for_constructor (tree);
116 static unsigned min_align (unsigned, unsigned);
117 static void globalize_decl (tree);
118 #ifdef BSS_SECTION_ASM_OP
119 #ifdef ASM_OUTPUT_BSS
120 static void asm_output_bss (FILE *, tree, const char *,
121 unsigned HOST_WIDE_INT, unsigned HOST_WIDE_INT);
122 #endif
123 #ifdef ASM_OUTPUT_ALIGNED_BSS
124 static void asm_output_aligned_bss (FILE *, tree, const char *,
125 unsigned HOST_WIDE_INT, int)
126 ATTRIBUTE_UNUSED;
127 #endif
128 #endif /* BSS_SECTION_ASM_OP */
129 static void mark_weak (tree);
130 static void output_constant_pool (const char *, tree);
132 /* Well-known sections, each one associated with some sort of *_ASM_OP. */
133 section *text_section;
134 section *data_section;
135 section *readonly_data_section;
136 section *sdata_section;
137 section *ctors_section;
138 section *dtors_section;
139 section *bss_section;
140 section *sbss_section;
142 /* Various forms of common section. All are guaranteed to be nonnull. */
143 section *tls_comm_section;
144 section *comm_section;
145 section *lcomm_section;
147 /* A SECTION_NOSWITCH section used for declaring global BSS variables.
148 May be null. */
149 section *bss_noswitch_section;
151 /* The section that holds the main exception table, when known. The section
152 is set either by the target's init_sections hook or by the first call to
153 switch_to_exception_section. */
154 section *exception_section;
156 /* The section that holds the DWARF2 frame unwind information, when known.
157 The section is set either by the target's init_sections hook or by the
158 first call to switch_to_eh_frame_section. */
159 section *eh_frame_section;
161 /* asm_out_file's current section. This is NULL if no section has yet
162 been selected or if we lose track of what the current section is. */
163 section *in_section;
165 /* True if code for the current function is currently being directed
166 at the cold section. */
167 bool in_cold_section_p;
169 /* A linked list of all the unnamed sections. */
170 static GTY(()) section *unnamed_sections;
172 /* Return a nonzero value if DECL has a section attribute. */
173 #ifndef IN_NAMED_SECTION
174 #define IN_NAMED_SECTION(DECL) \
175 ((TREE_CODE (DECL) == FUNCTION_DECL || TREE_CODE (DECL) == VAR_DECL) \
176 && DECL_SECTION_NAME (DECL) != NULL_TREE)
177 #endif
179 /* Hash table of named sections. */
180 static GTY((param_is (section))) htab_t section_htab;
182 /* A table of object_blocks, indexed by section. */
183 static GTY((param_is (struct object_block))) htab_t object_block_htab;
185 /* The next number to use for internal anchor labels. */
186 static GTY(()) int anchor_labelno;
188 /* A pool of constants that can be shared between functions. */
189 static GTY(()) struct rtx_constant_pool *shared_constant_pool;
191 /* TLS emulation. */
193 static GTY ((if_marked ("tree_map_marked_p"), param_is (struct tree_map)))
194 htab_t emutls_htab;
195 static GTY (()) tree emutls_object_type;
196 /* Emulated TLS objects have the TLS model TLS_MODEL_EMULATED. This
197 macro can be used on them to distinguish the control variable from
198 the initialization template. */
199 #define DECL_EMUTLS_VAR_P(D) (TREE_TYPE (D) == emutls_object_type)
201 #if !defined (NO_DOT_IN_LABEL)
202 # define EMUTLS_SEPARATOR "."
203 #elif !defined (NO_DOLLAR_IN_LABEL)
204 # define EMUTLS_SEPARATOR "$"
205 #else
206 # define EMUTLS_SEPARATOR "_"
207 #endif
209 /* Create an IDENTIFIER_NODE by prefixing PREFIX to the
210 IDENTIFIER_NODE NAME's name. */
212 static tree
213 prefix_name (const char *prefix, tree name)
215 unsigned plen = strlen (prefix);
216 unsigned nlen = strlen (IDENTIFIER_POINTER (name));
217 char *toname = (char *) alloca (plen + nlen + 1);
219 memcpy (toname, prefix, plen);
220 memcpy (toname + plen, IDENTIFIER_POINTER (name), nlen + 1);
222 return get_identifier (toname);
225 /* Create an identifier for the struct __emutls_object, given an identifier
226 of the DECL_ASSEMBLY_NAME of the original object. */
228 static tree
229 get_emutls_object_name (tree name)
231 const char *prefix = (targetm.emutls.var_prefix
232 ? targetm.emutls.var_prefix
233 : "__emutls_v" EMUTLS_SEPARATOR);
234 return prefix_name (prefix, name);
237 tree
238 default_emutls_var_fields (tree type, tree *name ATTRIBUTE_UNUSED)
240 tree word_type_node, field, next_field;
242 field = build_decl (UNKNOWN_LOCATION,
243 FIELD_DECL, get_identifier ("__templ"), ptr_type_node);
244 DECL_CONTEXT (field) = type;
245 next_field = field;
247 field = build_decl (UNKNOWN_LOCATION,
248 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 (UNKNOWN_LOCATION,
256 FIELD_DECL, get_identifier ("__align"),
257 word_type_node);
258 DECL_CONTEXT (field) = type;
259 TREE_CHAIN (field) = next_field;
260 next_field = field;
262 field = build_decl (UNKNOWN_LOCATION,
263 FIELD_DECL, get_identifier ("__size"), word_type_node);
264 DECL_CONTEXT (field) = type;
265 TREE_CHAIN (field) = next_field;
267 return field;
270 /* Create the structure for struct __emutls_object. This should match the
271 structure at the top of emutls.c, modulo the union there. */
273 static tree
274 get_emutls_object_type (void)
276 tree type, type_name, field;
278 type = emutls_object_type;
279 if (type)
280 return type;
282 emutls_object_type = type = lang_hooks.types.make_type (RECORD_TYPE);
283 type_name = NULL;
284 field = targetm.emutls.var_fields (type, &type_name);
285 if (!type_name)
286 type_name = get_identifier ("__emutls_object");
287 type_name = build_decl (UNKNOWN_LOCATION,
288 TYPE_DECL, type_name, type);
289 TYPE_NAME (type) = type_name;
290 TYPE_FIELDS (type) = field;
291 layout_type (type);
293 return type;
296 /* Create a read-only variable like DECL, with the same DECL_INITIAL.
297 This will be used for initializing the emulated tls data area. */
299 static tree
300 get_emutls_init_templ_addr (tree decl)
302 tree name, to;
304 if (targetm.emutls.register_common && !DECL_INITIAL (decl)
305 && !DECL_SECTION_NAME (decl))
306 return null_pointer_node;
308 name = DECL_ASSEMBLER_NAME (decl);
309 if (!targetm.emutls.tmpl_prefix || targetm.emutls.tmpl_prefix[0])
311 const char *prefix = (targetm.emutls.tmpl_prefix
312 ? targetm.emutls.tmpl_prefix
313 : "__emutls_t" EMUTLS_SEPARATOR);
314 name = prefix_name (prefix, name);
317 to = build_decl (DECL_SOURCE_LOCATION (decl),
318 VAR_DECL, name, TREE_TYPE (decl));
319 SET_DECL_ASSEMBLER_NAME (to, DECL_NAME (to));
320 DECL_TLS_MODEL (to) = TLS_MODEL_EMULATED;
321 DECL_ARTIFICIAL (to) = 1;
322 TREE_USED (to) = TREE_USED (decl);
323 TREE_READONLY (to) = 1;
324 DECL_IGNORED_P (to) = 1;
325 DECL_CONTEXT (to) = DECL_CONTEXT (decl);
326 DECL_SECTION_NAME (to) = DECL_SECTION_NAME (decl);
328 DECL_WEAK (to) = DECL_WEAK (decl);
329 if (DECL_ONE_ONLY (decl))
331 make_decl_one_only (to, DECL_ASSEMBLER_NAME (to));
332 TREE_STATIC (to) = TREE_STATIC (decl);
333 TREE_PUBLIC (to) = TREE_PUBLIC (decl);
334 DECL_VISIBILITY (to) = DECL_VISIBILITY (decl);
336 else
337 TREE_STATIC (to) = 1;
339 DECL_INITIAL (to) = DECL_INITIAL (decl);
340 DECL_INITIAL (decl) = NULL;
342 varpool_finalize_decl (to);
343 return build_fold_addr_expr (to);
346 /* When emulating tls, we use a control structure for use by the runtime.
347 Create and return this structure. */
349 tree
350 emutls_decl (tree decl)
352 tree name, to;
353 struct tree_map *h, in;
354 void **loc;
356 if (targetm.have_tls || decl == NULL || decl == error_mark_node
357 || TREE_CODE (decl) != VAR_DECL || ! DECL_THREAD_LOCAL_P (decl))
358 return decl;
360 /* Look up the object in the hash; return the control structure if
361 it has already been created. */
362 if (! emutls_htab)
363 emutls_htab = htab_create_ggc (512, tree_map_hash, tree_map_eq, 0);
365 name = DECL_ASSEMBLER_NAME (decl);
367 /* Note that we use the hash of the decl's name, rather than a hash
368 of the decl's pointer. In emutls_finish we iterate through the
369 hash table, and we want this traversal to be predictable. */
370 in.hash = htab_hash_string (IDENTIFIER_POINTER (name));
371 in.base.from = decl;
372 loc = htab_find_slot_with_hash (emutls_htab, &in, in.hash, INSERT);
373 h = (struct tree_map *) *loc;
374 if (h != NULL)
375 to = h->to;
376 else
378 to = build_decl (DECL_SOURCE_LOCATION (decl),
379 VAR_DECL, get_emutls_object_name (name),
380 get_emutls_object_type ());
382 h = GGC_NEW (struct tree_map);
383 h->hash = in.hash;
384 h->base.from = decl;
385 h->to = to;
386 *(struct tree_map **) loc = h;
388 DECL_TLS_MODEL (to) = TLS_MODEL_EMULATED;
389 DECL_ARTIFICIAL (to) = 1;
390 DECL_IGNORED_P (to) = 1;
391 TREE_READONLY (to) = 0;
392 SET_DECL_ASSEMBLER_NAME (to, DECL_NAME (to));
393 if (DECL_ONE_ONLY (decl))
394 make_decl_one_only (to, DECL_ASSEMBLER_NAME (to));
395 DECL_CONTEXT (to) = DECL_CONTEXT (decl);
396 if (targetm.emutls.var_align_fixed)
397 /* If we're not allowed to change the proxy object's
398 alignment, pretend it's been set by the user. */
399 DECL_USER_ALIGN (to) = 1;
402 /* Note that these fields may need to be updated from time to time from
403 the original decl. Consider:
404 extern __thread int i;
405 int foo() { return i; }
406 __thread int i = 1;
407 in which I goes from external to locally defined and initialized. */
409 TREE_STATIC (to) = TREE_STATIC (decl);
410 TREE_USED (to) = TREE_USED (decl);
411 TREE_PUBLIC (to) = TREE_PUBLIC (decl);
412 DECL_EXTERNAL (to) = DECL_EXTERNAL (decl);
413 DECL_COMMON (to) = DECL_COMMON (decl);
414 DECL_WEAK (to) = DECL_WEAK (decl);
415 DECL_VISIBILITY (to) = DECL_VISIBILITY (decl);
417 return to;
420 static int
421 emutls_common_1 (void **loc, void *xstmts)
423 struct tree_map *h = *(struct tree_map **) loc;
424 tree args, x, *pstmts = (tree *) xstmts;
425 tree word_type_node;
427 if (! DECL_COMMON (h->base.from)
428 || (DECL_INITIAL (h->base.from)
429 && DECL_INITIAL (h->base.from) != error_mark_node))
430 return 1;
432 word_type_node = lang_hooks.types.type_for_mode (word_mode, 1);
434 /* The idea was to call get_emutls_init_templ_addr here, but if we
435 do this and there is an initializer, -fanchor_section loses,
436 because it would be too late to ensure the template is
437 output. */
438 x = null_pointer_node;
439 args = tree_cons (NULL, x, NULL);
440 x = build_int_cst (word_type_node, DECL_ALIGN_UNIT (h->base.from));
441 args = tree_cons (NULL, x, args);
442 x = fold_convert (word_type_node, DECL_SIZE_UNIT (h->base.from));
443 args = tree_cons (NULL, x, args);
444 x = build_fold_addr_expr (h->to);
445 args = tree_cons (NULL, x, args);
447 x = built_in_decls[BUILT_IN_EMUTLS_REGISTER_COMMON];
448 x = build_function_call_expr (UNKNOWN_LOCATION, x, args);
450 append_to_statement_list (x, pstmts);
451 return 1;
454 void
455 emutls_finish (void)
457 if (targetm.emutls.register_common)
459 tree body = NULL_TREE;
461 if (emutls_htab == NULL)
462 return;
464 htab_traverse_noresize (emutls_htab, emutls_common_1, &body);
465 if (body == NULL_TREE)
466 return;
468 cgraph_build_static_cdtor ('I', body, DEFAULT_INIT_PRIORITY);
472 /* Helper routines for maintaining section_htab. */
474 static int
475 section_entry_eq (const void *p1, const void *p2)
477 const section *old = (const section *) p1;
478 const char *new_name = (const char *) p2;
480 return strcmp (old->named.name, new_name) == 0;
483 static hashval_t
484 section_entry_hash (const void *p)
486 const section *old = (const section *) p;
487 return htab_hash_string (old->named.name);
490 /* Return a hash value for section SECT. */
492 static hashval_t
493 hash_section (section *sect)
495 if (sect->common.flags & SECTION_NAMED)
496 return htab_hash_string (sect->named.name);
497 return sect->common.flags;
500 /* Helper routines for maintaining object_block_htab. */
502 static int
503 object_block_entry_eq (const void *p1, const void *p2)
505 const struct object_block *old = (const struct object_block *) p1;
506 const section *new_section = (const section *) p2;
508 return old->sect == new_section;
511 static hashval_t
512 object_block_entry_hash (const void *p)
514 const struct object_block *old = (const struct object_block *) p;
515 return hash_section (old->sect);
518 /* Return a new unnamed section with the given fields. */
520 section *
521 get_unnamed_section (unsigned int flags, void (*callback) (const void *),
522 const void *data)
524 section *sect;
526 sect = GGC_NEW (section);
527 sect->unnamed.common.flags = flags | SECTION_UNNAMED;
528 sect->unnamed.callback = callback;
529 sect->unnamed.data = data;
530 sect->unnamed.next = unnamed_sections;
532 unnamed_sections = sect;
533 return sect;
536 /* Return a SECTION_NOSWITCH section with the given fields. */
538 static section *
539 get_noswitch_section (unsigned int flags, noswitch_section_callback callback)
541 section *sect;
543 sect = GGC_NEW (section);
544 sect->noswitch.common.flags = flags | SECTION_NOSWITCH;
545 sect->noswitch.callback = callback;
547 return sect;
550 /* Return the named section structure associated with NAME. Create
551 a new section with the given fields if no such structure exists. */
553 section *
554 get_section (const char *name, unsigned int flags, tree decl)
556 section *sect, **slot;
558 slot = (section **)
559 htab_find_slot_with_hash (section_htab, name,
560 htab_hash_string (name), INSERT);
561 flags |= SECTION_NAMED;
562 if (*slot == NULL)
564 sect = GGC_NEW (section);
565 sect->named.common.flags = flags;
566 sect->named.name = ggc_strdup (name);
567 sect->named.decl = decl;
568 *slot = sect;
570 else
572 sect = *slot;
573 if ((sect->common.flags & ~SECTION_DECLARED) != flags
574 && ((sect->common.flags | flags) & SECTION_OVERRIDE) == 0)
576 /* Sanity check user variables for flag changes. */
577 if (decl == 0)
578 decl = sect->named.decl;
579 gcc_assert (decl);
580 error ("%+D causes a section type conflict", decl);
583 return sect;
586 /* Return true if the current compilation mode benefits from having
587 objects grouped into blocks. */
589 static bool
590 use_object_blocks_p (void)
592 return flag_section_anchors;
595 /* Return the object_block structure for section SECT. Create a new
596 structure if we haven't created one already. Return null if SECT
597 itself is null. */
599 static struct object_block *
600 get_block_for_section (section *sect)
602 struct object_block *block;
603 void **slot;
605 if (sect == NULL)
606 return NULL;
608 slot = htab_find_slot_with_hash (object_block_htab, sect,
609 hash_section (sect), INSERT);
610 block = (struct object_block *) *slot;
611 if (block == NULL)
613 block = (struct object_block *)
614 ggc_alloc_cleared (sizeof (struct object_block));
615 block->sect = sect;
616 *slot = block;
618 return block;
621 /* Create a symbol with label LABEL and place it at byte offset
622 OFFSET in BLOCK. OFFSET can be negative if the symbol's offset
623 is not yet known. LABEL must be a garbage-collected string. */
625 static rtx
626 create_block_symbol (const char *label, struct object_block *block,
627 HOST_WIDE_INT offset)
629 rtx symbol;
630 unsigned int size;
632 /* Create the extended SYMBOL_REF. */
633 size = RTX_HDR_SIZE + sizeof (struct block_symbol);
634 symbol = (rtx) ggc_alloc_zone (size, &rtl_zone);
636 /* Initialize the normal SYMBOL_REF fields. */
637 memset (symbol, 0, size);
638 PUT_CODE (symbol, SYMBOL_REF);
639 PUT_MODE (symbol, Pmode);
640 XSTR (symbol, 0) = label;
641 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_HAS_BLOCK_INFO;
643 /* Initialize the block_symbol stuff. */
644 SYMBOL_REF_BLOCK (symbol) = block;
645 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
647 return symbol;
650 static void
651 initialize_cold_section_name (void)
653 const char *stripped_name;
654 char *name, *buffer;
655 tree dsn;
657 gcc_assert (cfun && current_function_decl);
658 if (crtl->subsections.unlikely_text_section_name)
659 return;
661 dsn = DECL_SECTION_NAME (current_function_decl);
662 if (flag_function_sections && dsn)
664 name = (char *) alloca (TREE_STRING_LENGTH (dsn) + 1);
665 memcpy (name, TREE_STRING_POINTER (dsn), TREE_STRING_LENGTH (dsn) + 1);
667 stripped_name = targetm.strip_name_encoding (name);
669 buffer = ACONCAT ((stripped_name, "_unlikely", NULL));
670 crtl->subsections.unlikely_text_section_name = ggc_strdup (buffer);
672 else
673 crtl->subsections.unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
676 /* Tell assembler to switch to unlikely-to-be-executed text section. */
678 section *
679 unlikely_text_section (void)
681 if (cfun)
683 if (!crtl->subsections.unlikely_text_section_name)
684 initialize_cold_section_name ();
686 return get_named_section (NULL, crtl->subsections.unlikely_text_section_name, 0);
688 else
689 return get_named_section (NULL, UNLIKELY_EXECUTED_TEXT_SECTION_NAME, 0);
692 /* When called within a function context, return true if the function
693 has been assigned a cold text section and if SECT is that section.
694 When called outside a function context, return true if SECT is the
695 default cold section. */
697 bool
698 unlikely_text_section_p (section *sect)
700 const char *name;
702 if (cfun)
703 name = crtl->subsections.unlikely_text_section_name;
704 else
705 name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
707 return (name
708 && sect
709 && SECTION_STYLE (sect) == SECTION_NAMED
710 && strcmp (name, sect->named.name) == 0);
713 /* Return a section with a particular name and with whatever SECTION_*
714 flags section_type_flags deems appropriate. The name of the section
715 is taken from NAME if nonnull, otherwise it is taken from DECL's
716 DECL_SECTION_NAME. DECL is the decl associated with the section
717 (see the section comment for details) and RELOC is as for
718 section_type_flags. */
720 section *
721 get_named_section (tree decl, const char *name, int reloc)
723 unsigned int flags;
725 gcc_assert (!decl || DECL_P (decl));
726 if (name == NULL)
727 name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
729 flags = targetm.section_type_flags (decl, name, reloc);
731 return get_section (name, flags, decl);
734 /* If required, set DECL_SECTION_NAME to a unique name. */
736 void
737 resolve_unique_section (tree decl, int reloc ATTRIBUTE_UNUSED,
738 int flag_function_or_data_sections)
740 if (DECL_SECTION_NAME (decl) == NULL_TREE
741 && targetm.have_named_sections
742 && (flag_function_or_data_sections
743 || DECL_ONE_ONLY (decl)))
744 targetm.asm_out.unique_section (decl, reloc);
747 #ifdef BSS_SECTION_ASM_OP
749 #ifdef ASM_OUTPUT_BSS
751 /* Utility function for ASM_OUTPUT_BSS for targets to use if
752 they don't support alignments in .bss.
753 ??? It is believed that this function will work in most cases so such
754 support is localized here. */
756 static void
757 asm_output_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
758 const char *name,
759 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
760 unsigned HOST_WIDE_INT rounded)
762 gcc_assert (strcmp (XSTR (XEXP (DECL_RTL (decl), 0), 0), name) == 0);
763 targetm.asm_out.globalize_decl_name (file, decl);
764 switch_to_section (bss_section);
765 #ifdef ASM_DECLARE_OBJECT_NAME
766 last_assemble_variable_decl = decl;
767 ASM_DECLARE_OBJECT_NAME (file, name, decl);
768 #else
769 /* Standard thing is just output label for the object. */
770 ASM_OUTPUT_LABEL (file, name);
771 #endif /* ASM_DECLARE_OBJECT_NAME */
772 ASM_OUTPUT_SKIP (file, rounded ? rounded : 1);
775 #endif
777 #ifdef ASM_OUTPUT_ALIGNED_BSS
779 /* Utility function for targets to use in implementing
780 ASM_OUTPUT_ALIGNED_BSS.
781 ??? It is believed that this function will work in most cases so such
782 support is localized here. */
784 static void
785 asm_output_aligned_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
786 const char *name, unsigned HOST_WIDE_INT size,
787 int align)
789 switch_to_section (bss_section);
790 ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
791 #ifdef ASM_DECLARE_OBJECT_NAME
792 last_assemble_variable_decl = decl;
793 ASM_DECLARE_OBJECT_NAME (file, name, decl);
794 #else
795 /* Standard thing is just output label for the object. */
796 ASM_OUTPUT_LABEL (file, name);
797 #endif /* ASM_DECLARE_OBJECT_NAME */
798 ASM_OUTPUT_SKIP (file, size ? size : 1);
801 #endif
803 #endif /* BSS_SECTION_ASM_OP */
805 #ifndef USE_SELECT_SECTION_FOR_FUNCTIONS
806 /* Return the hot section for function DECL. Return text_section for
807 null DECLs. */
809 static section *
810 hot_function_section (tree decl)
812 if (decl != NULL_TREE
813 && DECL_SECTION_NAME (decl) != NULL_TREE
814 && targetm.have_named_sections)
815 return get_named_section (decl, NULL, 0);
816 else
817 return text_section;
819 #endif
821 /* Return the section for function DECL.
823 If DECL is NULL_TREE, return the text section. We can be passed
824 NULL_TREE under some circumstances by dbxout.c at least. */
826 section *
827 function_section (tree decl)
829 int reloc = 0;
831 if (first_function_block_is_cold)
832 reloc = 1;
834 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
835 if (decl != NULL_TREE
836 && DECL_SECTION_NAME (decl) != NULL_TREE)
837 return reloc ? unlikely_text_section ()
838 : get_named_section (decl, NULL, 0);
839 else
840 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
841 #else
842 return reloc ? unlikely_text_section () : hot_function_section (decl);
843 #endif
846 section *
847 current_function_section (void)
849 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
850 if (current_function_decl != NULL_TREE
851 && DECL_SECTION_NAME (current_function_decl) != NULL_TREE)
852 return in_cold_section_p ? unlikely_text_section ()
853 : get_named_section (current_function_decl,
854 NULL, 0);
855 else
856 return targetm.asm_out.select_section (current_function_decl,
857 in_cold_section_p,
858 DECL_ALIGN (current_function_decl));
859 #else
860 return (in_cold_section_p
861 ? unlikely_text_section ()
862 : hot_function_section (current_function_decl));
863 #endif
866 /* Return the read-only data section associated with function DECL. */
868 section *
869 default_function_rodata_section (tree decl)
871 if (decl != NULL_TREE && DECL_SECTION_NAME (decl))
873 const char *name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
875 if (DECL_ONE_ONLY (decl) && HAVE_COMDAT_GROUP)
877 const char *dot;
878 size_t len;
879 char* rname;
881 dot = strchr (name + 1, '.');
882 if (!dot)
883 dot = name;
884 len = strlen (dot) + 8;
885 rname = (char *) alloca (len);
887 strcpy (rname, ".rodata");
888 strcat (rname, dot);
889 return get_section (rname, SECTION_LINKONCE, decl);
891 /* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo. */
892 else if (DECL_ONE_ONLY (decl)
893 && strncmp (name, ".gnu.linkonce.t.", 16) == 0)
895 size_t len = strlen (name) + 1;
896 char *rname = (char *) alloca (len);
898 memcpy (rname, name, len);
899 rname[14] = 'r';
900 return get_section (rname, SECTION_LINKONCE, decl);
902 /* For .text.foo we want to use .rodata.foo. */
903 else if (flag_function_sections && flag_data_sections
904 && strncmp (name, ".text.", 6) == 0)
906 size_t len = strlen (name) + 1;
907 char *rname = (char *) alloca (len + 2);
909 memcpy (rname, ".rodata", 7);
910 memcpy (rname + 7, name + 5, len - 5);
911 return get_section (rname, 0, decl);
915 return readonly_data_section;
918 /* Return the read-only data section associated with function DECL
919 for targets where that section should be always the single
920 readonly data section. */
922 section *
923 default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED)
925 return readonly_data_section;
928 /* Return the section to use for string merging. */
930 static section *
931 mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
932 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
933 unsigned int flags ATTRIBUTE_UNUSED)
935 HOST_WIDE_INT len;
937 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
938 && TREE_CODE (decl) == STRING_CST
939 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
940 && align <= 256
941 && (len = int_size_in_bytes (TREE_TYPE (decl))) > 0
942 && TREE_STRING_LENGTH (decl) >= len)
944 enum machine_mode mode;
945 unsigned int modesize;
946 const char *str;
947 HOST_WIDE_INT i;
948 int j, unit;
949 char name[30];
951 mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl)));
952 modesize = GET_MODE_BITSIZE (mode);
953 if (modesize >= 8 && modesize <= 256
954 && (modesize & (modesize - 1)) == 0)
956 if (align < modesize)
957 align = modesize;
959 str = TREE_STRING_POINTER (decl);
960 unit = GET_MODE_SIZE (mode);
962 /* Check for embedded NUL characters. */
963 for (i = 0; i < len; i += unit)
965 for (j = 0; j < unit; j++)
966 if (str[i + j] != '\0')
967 break;
968 if (j == unit)
969 break;
971 if (i == len - unit)
973 sprintf (name, ".rodata.str%d.%d", modesize / 8,
974 (int) (align / 8));
975 flags |= (modesize / 8) | SECTION_MERGE | SECTION_STRINGS;
976 return get_section (name, flags, NULL);
981 return readonly_data_section;
984 /* Return the section to use for constant merging. */
986 section *
987 mergeable_constant_section (enum machine_mode mode ATTRIBUTE_UNUSED,
988 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
989 unsigned int flags ATTRIBUTE_UNUSED)
991 unsigned int modesize = GET_MODE_BITSIZE (mode);
993 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
994 && mode != VOIDmode
995 && mode != BLKmode
996 && modesize <= align
997 && align >= 8
998 && align <= 256
999 && (align & (align - 1)) == 0)
1001 char name[24];
1003 sprintf (name, ".rodata.cst%d", (int) (align / 8));
1004 flags |= (align / 8) | SECTION_MERGE;
1005 return get_section (name, flags, NULL);
1007 return readonly_data_section;
1010 /* Given NAME, a putative register name, discard any customary prefixes. */
1012 static const char *
1013 strip_reg_name (const char *name)
1015 #ifdef REGISTER_PREFIX
1016 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
1017 name += strlen (REGISTER_PREFIX);
1018 #endif
1019 if (name[0] == '%' || name[0] == '#')
1020 name++;
1021 return name;
1024 /* The user has asked for a DECL to have a particular name. Set (or
1025 change) it in such a way that we don't prefix an underscore to
1026 it. */
1027 void
1028 set_user_assembler_name (tree decl, const char *name)
1030 char *starred = (char *) alloca (strlen (name) + 2);
1031 starred[0] = '*';
1032 strcpy (starred + 1, name);
1033 change_decl_assembler_name (decl, get_identifier (starred));
1034 SET_DECL_RTL (decl, NULL_RTX);
1037 /* Decode an `asm' spec for a declaration as a register name.
1038 Return the register number, or -1 if nothing specified,
1039 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
1040 or -3 if ASMSPEC is `cc' and is not recognized,
1041 or -4 if ASMSPEC is `memory' and is not recognized.
1042 Accept an exact spelling or a decimal number.
1043 Prefixes such as % are optional. */
1046 decode_reg_name (const char *asmspec)
1048 if (asmspec != 0)
1050 int i;
1052 /* Get rid of confusing prefixes. */
1053 asmspec = strip_reg_name (asmspec);
1055 /* Allow a decimal number as a "register name". */
1056 for (i = strlen (asmspec) - 1; i >= 0; i--)
1057 if (! ISDIGIT (asmspec[i]))
1058 break;
1059 if (asmspec[0] != 0 && i < 0)
1061 i = atoi (asmspec);
1062 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
1063 return i;
1064 else
1065 return -2;
1068 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1069 if (reg_names[i][0]
1070 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
1071 return i;
1073 #ifdef ADDITIONAL_REGISTER_NAMES
1075 static const struct { const char *const name; const int number; } table[]
1076 = ADDITIONAL_REGISTER_NAMES;
1078 for (i = 0; i < (int) ARRAY_SIZE (table); i++)
1079 if (table[i].name[0]
1080 && ! strcmp (asmspec, table[i].name))
1081 return table[i].number;
1083 #endif /* ADDITIONAL_REGISTER_NAMES */
1085 if (!strcmp (asmspec, "memory"))
1086 return -4;
1088 if (!strcmp (asmspec, "cc"))
1089 return -3;
1091 return -2;
1094 return -1;
1097 /* Return true if DECL's initializer is suitable for a BSS section. */
1099 static bool
1100 bss_initializer_p (const_tree decl)
1102 return (DECL_INITIAL (decl) == NULL
1103 || DECL_INITIAL (decl) == error_mark_node
1104 || (flag_zero_initialized_in_bss
1105 /* Leave constant zeroes in .rodata so they
1106 can be shared. */
1107 && !TREE_READONLY (decl)
1108 && initializer_zerop (DECL_INITIAL (decl))));
1111 /* Compute the alignment of variable specified by DECL.
1112 DONT_OUTPUT_DATA is from assemble_variable. */
1114 void
1115 align_variable (tree decl, bool dont_output_data)
1117 unsigned int align = DECL_ALIGN (decl);
1119 /* In the case for initialing an array whose length isn't specified,
1120 where we have not yet been able to do the layout,
1121 figure out the proper alignment now. */
1122 if (dont_output_data && DECL_SIZE (decl) == 0
1123 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
1124 align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
1126 /* Some object file formats have a maximum alignment which they support.
1127 In particular, a.out format supports a maximum alignment of 4. */
1128 if (align > MAX_OFILE_ALIGNMENT)
1130 warning (0, "alignment of %q+D is greater than maximum object "
1131 "file alignment. Using %d", decl,
1132 MAX_OFILE_ALIGNMENT/BITS_PER_UNIT);
1133 align = MAX_OFILE_ALIGNMENT;
1136 /* On some machines, it is good to increase alignment sometimes. */
1137 if (! DECL_USER_ALIGN (decl))
1139 #ifdef DATA_ALIGNMENT
1140 unsigned int data_align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
1141 /* Don't increase alignment too much for TLS variables - TLS space
1142 is too precious. */
1143 if (! DECL_THREAD_LOCAL_P (decl) || data_align <= BITS_PER_WORD)
1144 align = data_align;
1145 #endif
1146 #ifdef CONSTANT_ALIGNMENT
1147 if (DECL_INITIAL (decl) != 0 && DECL_INITIAL (decl) != error_mark_node)
1149 unsigned int const_align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl),
1150 align);
1151 /* Don't increase alignment too much for TLS variables - TLS space
1152 is too precious. */
1153 if (! DECL_THREAD_LOCAL_P (decl) || const_align <= BITS_PER_WORD)
1154 align = const_align;
1156 #endif
1159 /* Reset the alignment in case we have made it tighter, so we can benefit
1160 from it in get_pointer_alignment. */
1161 DECL_ALIGN (decl) = align;
1164 /* Return the section into which the given VAR_DECL or CONST_DECL
1165 should be placed. PREFER_NOSWITCH_P is true if a noswitch
1166 section should be used wherever possible. */
1168 static section *
1169 get_variable_section (tree decl, bool prefer_noswitch_p)
1171 addr_space_t as = ADDR_SPACE_GENERIC;
1172 int reloc;
1174 if (TREE_TYPE (decl) != error_mark_node)
1175 as = TYPE_ADDR_SPACE (TREE_TYPE (decl));
1177 /* If the decl has been given an explicit section name, or it resides
1178 in a non-generic address space, then it isn't common, and shouldn't
1179 be handled as such. */
1180 if (DECL_COMMON (decl) && DECL_SECTION_NAME (decl) == NULL
1181 && ADDR_SPACE_GENERIC_P (as))
1183 if (DECL_THREAD_LOCAL_P (decl))
1184 return tls_comm_section;
1185 /* This cannot be common bss for an emulated TLS object without
1186 a register_common hook. */
1187 else if (DECL_TLS_MODEL (decl) == TLS_MODEL_EMULATED
1188 && !targetm.emutls.register_common)
1190 else if (TREE_PUBLIC (decl) && bss_initializer_p (decl))
1191 return comm_section;
1194 if (DECL_INITIAL (decl) == error_mark_node)
1195 reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;
1196 else if (DECL_INITIAL (decl))
1197 reloc = compute_reloc_for_constant (DECL_INITIAL (decl));
1198 else
1199 reloc = 0;
1201 resolve_unique_section (decl, reloc, flag_data_sections);
1202 if (IN_NAMED_SECTION (decl))
1203 return get_named_section (decl, NULL, reloc);
1205 if (ADDR_SPACE_GENERIC_P (as)
1206 && !DECL_THREAD_LOCAL_P (decl)
1207 && !(prefer_noswitch_p && targetm.have_switchable_bss_sections)
1208 && bss_initializer_p (decl))
1210 if (!TREE_PUBLIC (decl))
1211 return lcomm_section;
1212 if (bss_noswitch_section)
1213 return bss_noswitch_section;
1216 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
1219 /* Return the block into which object_block DECL should be placed. */
1221 static struct object_block *
1222 get_block_for_decl (tree decl)
1224 section *sect;
1226 if (TREE_CODE (decl) == VAR_DECL)
1228 /* The object must be defined in this translation unit. */
1229 if (DECL_EXTERNAL (decl))
1230 return NULL;
1232 /* There's no point using object blocks for something that is
1233 isolated by definition. */
1234 if (DECL_ONE_ONLY (decl))
1235 return NULL;
1238 /* We can only calculate block offsets if the decl has a known
1239 constant size. */
1240 if (DECL_SIZE_UNIT (decl) == NULL)
1241 return NULL;
1242 if (!host_integerp (DECL_SIZE_UNIT (decl), 1))
1243 return NULL;
1245 /* Find out which section should contain DECL. We cannot put it into
1246 an object block if it requires a standalone definition. */
1247 if (TREE_CODE (decl) == VAR_DECL)
1248 align_variable (decl, 0);
1249 sect = get_variable_section (decl, true);
1250 if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
1251 return NULL;
1253 return get_block_for_section (sect);
1256 /* Make sure block symbol SYMBOL is in block BLOCK. */
1258 static void
1259 change_symbol_block (rtx symbol, struct object_block *block)
1261 if (block != SYMBOL_REF_BLOCK (symbol))
1263 gcc_assert (SYMBOL_REF_BLOCK_OFFSET (symbol) < 0);
1264 SYMBOL_REF_BLOCK (symbol) = block;
1268 /* Return true if it is possible to put DECL in an object_block. */
1270 static bool
1271 use_blocks_for_decl_p (tree decl)
1273 /* Only data DECLs can be placed into object blocks. */
1274 if (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != CONST_DECL)
1275 return false;
1277 /* Detect decls created by dw2_force_const_mem. Such decls are
1278 special because DECL_INITIAL doesn't specify the decl's true value.
1279 dw2_output_indirect_constants will instead call assemble_variable
1280 with dont_output_data set to 1 and then print the contents itself. */
1281 if (DECL_INITIAL (decl) == decl)
1282 return false;
1284 /* If this decl is an alias, then we don't want to emit a definition. */
1285 if (lookup_attribute ("alias", DECL_ATTRIBUTES (decl)))
1286 return false;
1288 return true;
1291 /* Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL should
1292 have static storage duration. In other words, it should not be an
1293 automatic variable, including PARM_DECLs.
1295 There is, however, one exception: this function handles variables
1296 explicitly placed in a particular register by the user.
1298 This is never called for PARM_DECL nodes. */
1300 void
1301 make_decl_rtl (tree decl)
1303 const char *name = 0;
1304 int reg_number;
1305 rtx x;
1307 /* Check that we are not being given an automatic variable. */
1308 gcc_assert (TREE_CODE (decl) != PARM_DECL
1309 && TREE_CODE (decl) != RESULT_DECL);
1311 /* A weak alias has TREE_PUBLIC set but not the other bits. */
1312 gcc_assert (TREE_CODE (decl) != VAR_DECL
1313 || TREE_STATIC (decl)
1314 || TREE_PUBLIC (decl)
1315 || DECL_EXTERNAL (decl)
1316 || DECL_REGISTER (decl));
1318 /* And that we were not given a type or a label. */
1319 gcc_assert (TREE_CODE (decl) != TYPE_DECL
1320 && TREE_CODE (decl) != LABEL_DECL);
1322 /* For a duplicate declaration, we can be called twice on the
1323 same DECL node. Don't discard the RTL already made. */
1324 if (DECL_RTL_SET_P (decl))
1326 /* If the old RTL had the wrong mode, fix the mode. */
1327 x = DECL_RTL (decl);
1328 if (GET_MODE (x) != DECL_MODE (decl))
1329 SET_DECL_RTL (decl, adjust_address_nv (x, DECL_MODE (decl), 0));
1331 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1332 return;
1334 /* ??? Another way to do this would be to maintain a hashed
1335 table of such critters. Instead of adding stuff to a DECL
1336 to give certain attributes to it, we could use an external
1337 hash map from DECL to set of attributes. */
1339 /* Let the target reassign the RTL if it wants.
1340 This is necessary, for example, when one machine specific
1341 decl attribute overrides another. */
1342 targetm.encode_section_info (decl, DECL_RTL (decl), false);
1344 /* If the symbol has a SYMBOL_REF_BLOCK field, update it based
1345 on the new decl information. */
1346 if (MEM_P (x)
1347 && GET_CODE (XEXP (x, 0)) == SYMBOL_REF
1348 && SYMBOL_REF_HAS_BLOCK_INFO_P (XEXP (x, 0)))
1349 change_symbol_block (XEXP (x, 0), get_block_for_decl (decl));
1351 /* Make this function static known to the mudflap runtime. */
1352 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
1353 mudflap_enqueue_decl (decl);
1355 return;
1358 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
1360 if (name[0] != '*' && TREE_CODE (decl) != FUNCTION_DECL
1361 && DECL_REGISTER (decl))
1363 error ("register name not specified for %q+D", decl);
1365 else if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1367 const char *asmspec = name+1;
1368 reg_number = decode_reg_name (asmspec);
1369 /* First detect errors in declaring global registers. */
1370 if (reg_number == -1)
1371 error ("register name not specified for %q+D", decl);
1372 else if (reg_number < 0)
1373 error ("invalid register name for %q+D", decl);
1374 else if (TYPE_MODE (TREE_TYPE (decl)) == BLKmode)
1375 error ("data type of %q+D isn%'t suitable for a register",
1376 decl);
1377 else if (! HARD_REGNO_MODE_OK (reg_number, TYPE_MODE (TREE_TYPE (decl))))
1378 error ("register specified for %q+D isn%'t suitable for data type",
1379 decl);
1380 /* Now handle properly declared static register variables. */
1381 else
1383 int nregs;
1385 if (DECL_INITIAL (decl) != 0 && TREE_STATIC (decl))
1387 DECL_INITIAL (decl) = 0;
1388 error ("global register variable has initial value");
1390 if (TREE_THIS_VOLATILE (decl))
1391 warning (OPT_Wvolatile_register_var,
1392 "optimization may eliminate reads and/or "
1393 "writes to register variables");
1395 /* If the user specified one of the eliminables registers here,
1396 e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
1397 confused with that register and be eliminated. This usage is
1398 somewhat suspect... */
1400 SET_DECL_RTL (decl, gen_rtx_raw_REG (DECL_MODE (decl), reg_number));
1401 ORIGINAL_REGNO (DECL_RTL (decl)) = reg_number;
1402 REG_USERVAR_P (DECL_RTL (decl)) = 1;
1404 if (TREE_STATIC (decl))
1406 /* Make this register global, so not usable for anything
1407 else. */
1408 #ifdef ASM_DECLARE_REGISTER_GLOBAL
1409 name = IDENTIFIER_POINTER (DECL_NAME (decl));
1410 ASM_DECLARE_REGISTER_GLOBAL (asm_out_file, decl, reg_number, name);
1411 #endif
1412 nregs = hard_regno_nregs[reg_number][DECL_MODE (decl)];
1413 while (nregs > 0)
1414 globalize_reg (reg_number + --nregs);
1417 /* As a register variable, it has no section. */
1418 return;
1421 /* Now handle ordinary static variables and functions (in memory).
1422 Also handle vars declared register invalidly. */
1423 else if (name[0] == '*')
1425 #ifdef REGISTER_PREFIX
1426 if (strlen (REGISTER_PREFIX) != 0)
1428 reg_number = decode_reg_name (name);
1429 if (reg_number >= 0 || reg_number == -3)
1430 error ("register name given for non-register variable %q+D", decl);
1432 #endif
1435 /* Specifying a section attribute on a variable forces it into a
1436 non-.bss section, and thus it cannot be common. */
1437 if (TREE_CODE (decl) == VAR_DECL
1438 && DECL_SECTION_NAME (decl) != NULL_TREE
1439 && DECL_INITIAL (decl) == NULL_TREE
1440 && DECL_COMMON (decl))
1441 DECL_COMMON (decl) = 0;
1443 /* Variables can't be both common and weak. */
1444 if (TREE_CODE (decl) == VAR_DECL && DECL_WEAK (decl))
1445 DECL_COMMON (decl) = 0;
1447 if (use_object_blocks_p () && use_blocks_for_decl_p (decl))
1448 x = create_block_symbol (name, get_block_for_decl (decl), -1);
1449 else
1451 enum machine_mode address_mode = Pmode;
1452 if (TREE_TYPE (decl) != error_mark_node)
1454 addr_space_t as = TYPE_ADDR_SPACE (TREE_TYPE (decl));
1455 address_mode = targetm.addr_space.address_mode (as);
1457 x = gen_rtx_SYMBOL_REF (address_mode, name);
1459 SYMBOL_REF_WEAK (x) = DECL_WEAK (decl);
1460 SET_SYMBOL_REF_DECL (x, decl);
1462 x = gen_rtx_MEM (DECL_MODE (decl), x);
1463 if (TREE_CODE (decl) != FUNCTION_DECL)
1464 set_mem_attributes (x, decl, 1);
1465 SET_DECL_RTL (decl, x);
1467 /* Optionally set flags or add text to the name to record information
1468 such as that it is a function name.
1469 If the name is changed, the macro ASM_OUTPUT_LABELREF
1470 will have to know how to strip this information. */
1471 targetm.encode_section_info (decl, DECL_RTL (decl), true);
1473 /* Make this function static known to the mudflap runtime. */
1474 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
1475 mudflap_enqueue_decl (decl);
1478 /* Output a string of literal assembler code
1479 for an `asm' keyword used between functions. */
1481 void
1482 assemble_asm (tree string)
1484 app_enable ();
1486 if (TREE_CODE (string) == ADDR_EXPR)
1487 string = TREE_OPERAND (string, 0);
1489 fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string));
1492 /* Record an element in the table of global destructors. SYMBOL is
1493 a SYMBOL_REF of the function to be called; PRIORITY is a number
1494 between 0 and MAX_INIT_PRIORITY. */
1496 void
1497 default_stabs_asm_out_destructor (rtx symbol ATTRIBUTE_UNUSED,
1498 int priority ATTRIBUTE_UNUSED)
1500 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1501 /* Tell GNU LD that this is part of the static destructor set.
1502 This will work for any system that uses stabs, most usefully
1503 aout systems. */
1504 dbxout_begin_simple_stabs ("___DTOR_LIST__", 22 /* N_SETT */);
1505 dbxout_stab_value_label (XSTR (symbol, 0));
1506 #else
1507 sorry ("global destructors not supported on this target");
1508 #endif
1511 /* Write the address of the entity given by SYMBOL to SEC. */
1512 void
1513 assemble_addr_to_section (rtx symbol, section *sec)
1515 switch_to_section (sec);
1516 assemble_align (POINTER_SIZE);
1517 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1520 /* Return the numbered .ctors.N (if CONSTRUCTOR_P) or .dtors.N (if
1521 not) section for PRIORITY. */
1522 section *
1523 get_cdtor_priority_section (int priority, bool constructor_p)
1525 char buf[16];
1527 /* ??? This only works reliably with the GNU linker. */
1528 sprintf (buf, "%s.%.5u",
1529 constructor_p ? ".ctors" : ".dtors",
1530 /* Invert the numbering so the linker puts us in the proper
1531 order; constructors are run from right to left, and the
1532 linker sorts in increasing order. */
1533 MAX_INIT_PRIORITY - priority);
1534 return get_section (buf, SECTION_WRITE, NULL);
1537 void
1538 default_named_section_asm_out_destructor (rtx symbol, int priority)
1540 section *sec;
1542 if (priority != DEFAULT_INIT_PRIORITY)
1543 sec = get_cdtor_priority_section (priority,
1544 /*constructor_p=*/false);
1545 else
1546 sec = get_section (".dtors", SECTION_WRITE, NULL);
1548 assemble_addr_to_section (symbol, sec);
1551 #ifdef DTORS_SECTION_ASM_OP
1552 void
1553 default_dtor_section_asm_out_destructor (rtx symbol,
1554 int priority ATTRIBUTE_UNUSED)
1556 assemble_addr_to_section (symbol, dtors_section);
1558 #endif
1560 /* Likewise for global constructors. */
1562 void
1563 default_stabs_asm_out_constructor (rtx symbol ATTRIBUTE_UNUSED,
1564 int priority ATTRIBUTE_UNUSED)
1566 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1567 /* Tell GNU LD that this is part of the static destructor set.
1568 This will work for any system that uses stabs, most usefully
1569 aout systems. */
1570 dbxout_begin_simple_stabs ("___CTOR_LIST__", 22 /* N_SETT */);
1571 dbxout_stab_value_label (XSTR (symbol, 0));
1572 #else
1573 sorry ("global constructors not supported on this target");
1574 #endif
1577 void
1578 default_named_section_asm_out_constructor (rtx symbol, int priority)
1580 section *sec;
1582 if (priority != DEFAULT_INIT_PRIORITY)
1583 sec = get_cdtor_priority_section (priority,
1584 /*constructor_p=*/true);
1585 else
1586 sec = get_section (".ctors", SECTION_WRITE, NULL);
1588 assemble_addr_to_section (symbol, sec);
1591 #ifdef CTORS_SECTION_ASM_OP
1592 void
1593 default_ctor_section_asm_out_constructor (rtx symbol,
1594 int priority ATTRIBUTE_UNUSED)
1596 assemble_addr_to_section (symbol, ctors_section);
1598 #endif
1600 /* CONSTANT_POOL_BEFORE_FUNCTION may be defined as an expression with
1601 a nonzero value if the constant pool should be output before the
1602 start of the function, or a zero value if the pool should output
1603 after the end of the function. The default is to put it before the
1604 start. */
1606 #ifndef CONSTANT_POOL_BEFORE_FUNCTION
1607 #define CONSTANT_POOL_BEFORE_FUNCTION 1
1608 #endif
1610 /* DECL is an object (either VAR_DECL or FUNCTION_DECL) which is going
1611 to be output to assembler.
1612 Set first_global_object_name and weak_global_object_name as appropriate. */
1614 void
1615 notice_global_symbol (tree decl)
1617 const char **type = &first_global_object_name;
1619 if (first_global_object_name
1620 || !TREE_PUBLIC (decl)
1621 || DECL_EXTERNAL (decl)
1622 || !DECL_NAME (decl)
1623 || (TREE_CODE (decl) != FUNCTION_DECL
1624 && (TREE_CODE (decl) != VAR_DECL
1625 || (DECL_COMMON (decl)
1626 && (DECL_INITIAL (decl) == 0
1627 || DECL_INITIAL (decl) == error_mark_node))))
1628 || !MEM_P (DECL_RTL (decl)))
1629 return;
1631 /* We win when global object is found, but it is useful to know about weak
1632 symbol as well so we can produce nicer unique names. */
1633 if (DECL_WEAK (decl) || DECL_ONE_ONLY (decl) || flag_shlib)
1634 type = &weak_global_object_name;
1636 if (!*type)
1638 const char *p;
1639 const char *name;
1640 rtx decl_rtl = DECL_RTL (decl);
1642 p = targetm.strip_name_encoding (XSTR (XEXP (decl_rtl, 0), 0));
1643 name = ggc_strdup (p);
1645 *type = name;
1649 /* Output assembler code for the constant pool of a function and associated
1650 with defining the name of the function. DECL describes the function.
1651 NAME is the function's name. For the constant pool, we use the current
1652 constant pool data. */
1654 void
1655 assemble_start_function (tree decl, const char *fnname)
1657 int align;
1658 char tmp_label[100];
1659 bool hot_label_written = false;
1661 crtl->subsections.unlikely_text_section_name = NULL;
1663 first_function_block_is_cold = false;
1664 if (flag_reorder_blocks_and_partition)
1666 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTB", const_labelno);
1667 crtl->subsections.hot_section_label = ggc_strdup (tmp_label);
1668 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDB", const_labelno);
1669 crtl->subsections.cold_section_label = ggc_strdup (tmp_label);
1670 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTE", const_labelno);
1671 crtl->subsections.hot_section_end_label = ggc_strdup (tmp_label);
1672 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDE", const_labelno);
1673 crtl->subsections.cold_section_end_label = ggc_strdup (tmp_label);
1674 const_labelno++;
1676 else
1678 crtl->subsections.hot_section_label = NULL;
1679 crtl->subsections.cold_section_label = NULL;
1680 crtl->subsections.hot_section_end_label = NULL;
1681 crtl->subsections.cold_section_end_label = NULL;
1684 /* The following code does not need preprocessing in the assembler. */
1686 app_disable ();
1688 if (CONSTANT_POOL_BEFORE_FUNCTION)
1689 output_constant_pool (fnname, decl);
1691 resolve_unique_section (decl, 0, flag_function_sections);
1693 /* Make sure the not and cold text (code) sections are properly
1694 aligned. This is necessary here in the case where the function
1695 has both hot and cold sections, because we don't want to re-set
1696 the alignment when the section switch happens mid-function. */
1698 if (flag_reorder_blocks_and_partition)
1700 switch_to_section (unlikely_text_section ());
1701 assemble_align (DECL_ALIGN (decl));
1702 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.cold_section_label);
1704 /* When the function starts with a cold section, we need to explicitly
1705 align the hot section and write out the hot section label.
1706 But if the current function is a thunk, we do not have a CFG. */
1707 if (!cfun->is_thunk
1708 && BB_PARTITION (ENTRY_BLOCK_PTR->next_bb) == BB_COLD_PARTITION)
1710 switch_to_section (text_section);
1711 assemble_align (DECL_ALIGN (decl));
1712 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_label);
1713 hot_label_written = true;
1714 first_function_block_is_cold = true;
1717 else if (DECL_SECTION_NAME (decl))
1719 /* Calls to function_section rely on first_function_block_is_cold
1720 being accurate. The first block may be cold even if we aren't
1721 doing partitioning, if the entire function was decided by
1722 choose_function_section (predict.c) to be cold. */
1724 initialize_cold_section_name ();
1726 if (crtl->subsections.unlikely_text_section_name
1727 && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
1728 crtl->subsections.unlikely_text_section_name) == 0)
1729 first_function_block_is_cold = true;
1732 in_cold_section_p = first_function_block_is_cold;
1734 /* Switch to the correct text section for the start of the function. */
1736 switch_to_section (function_section (decl));
1737 if (flag_reorder_blocks_and_partition
1738 && !hot_label_written)
1739 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_label);
1741 /* Tell assembler to move to target machine's alignment for functions. */
1742 align = floor_log2 (DECL_ALIGN (decl) / BITS_PER_UNIT);
1743 if (align > 0)
1745 ASM_OUTPUT_ALIGN (asm_out_file, align);
1748 /* Handle a user-specified function alignment.
1749 Note that we still need to align to DECL_ALIGN, as above,
1750 because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */
1751 if (! DECL_USER_ALIGN (decl)
1752 && align_functions_log > align
1753 && optimize_function_for_speed_p (cfun))
1755 #ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
1756 ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file,
1757 align_functions_log, align_functions - 1);
1758 #else
1759 ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log);
1760 #endif
1763 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
1764 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
1765 #endif
1767 if (!DECL_IGNORED_P (decl))
1768 (*debug_hooks->begin_function) (decl);
1770 /* Make function name accessible from other files, if appropriate. */
1772 if (TREE_PUBLIC (decl))
1774 notice_global_symbol (decl);
1776 globalize_decl (decl);
1778 maybe_assemble_visibility (decl);
1781 if (DECL_PRESERVE_P (decl))
1782 targetm.asm_out.mark_decl_preserved (fnname);
1784 /* Do any machine/system dependent processing of the function name. */
1785 #ifdef ASM_DECLARE_FUNCTION_NAME
1786 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
1787 #else
1788 /* Standard thing is just output label for the function. */
1789 ASM_OUTPUT_LABEL (asm_out_file, fnname);
1790 #endif /* ASM_DECLARE_FUNCTION_NAME */
1793 /* Output assembler code associated with defining the size of the
1794 function. DECL describes the function. NAME is the function's name. */
1796 void
1797 assemble_end_function (tree decl, const char *fnname ATTRIBUTE_UNUSED)
1799 #ifdef ASM_DECLARE_FUNCTION_SIZE
1800 /* We could have switched section in the middle of the function. */
1801 if (flag_reorder_blocks_and_partition)
1802 switch_to_section (function_section (decl));
1803 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
1804 #endif
1805 if (! CONSTANT_POOL_BEFORE_FUNCTION)
1807 output_constant_pool (fnname, decl);
1808 switch_to_section (function_section (decl)); /* need to switch back */
1810 /* Output labels for end of hot/cold text sections (to be used by
1811 debug info.) */
1812 if (flag_reorder_blocks_and_partition)
1814 section *save_text_section;
1816 save_text_section = in_section;
1817 switch_to_section (unlikely_text_section ());
1818 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.cold_section_end_label);
1819 if (first_function_block_is_cold)
1820 switch_to_section (text_section);
1821 else
1822 switch_to_section (function_section (decl));
1823 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_end_label);
1824 switch_to_section (save_text_section);
1828 /* Assemble code to leave SIZE bytes of zeros. */
1830 void
1831 assemble_zeros (unsigned HOST_WIDE_INT size)
1833 /* Do no output if -fsyntax-only. */
1834 if (flag_syntax_only)
1835 return;
1837 #ifdef ASM_NO_SKIP_IN_TEXT
1838 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
1839 so we must output 0s explicitly in the text section. */
1840 if (ASM_NO_SKIP_IN_TEXT && (in_section->common.flags & SECTION_CODE) != 0)
1842 unsigned HOST_WIDE_INT i;
1843 for (i = 0; i < size; i++)
1844 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1);
1846 else
1847 #endif
1848 if (size > 0)
1849 ASM_OUTPUT_SKIP (asm_out_file, size);
1852 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
1854 void
1855 assemble_align (int align)
1857 if (align > BITS_PER_UNIT)
1859 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1863 /* Assemble a string constant with the specified C string as contents. */
1865 void
1866 assemble_string (const char *p, int size)
1868 int pos = 0;
1869 int maximum = 2000;
1871 /* If the string is very long, split it up. */
1873 while (pos < size)
1875 int thissize = size - pos;
1876 if (thissize > maximum)
1877 thissize = maximum;
1879 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
1881 pos += thissize;
1882 p += thissize;
1887 /* A noswitch_section_callback for lcomm_section. */
1889 static bool
1890 emit_local (tree decl ATTRIBUTE_UNUSED,
1891 const char *name ATTRIBUTE_UNUSED,
1892 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1893 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1895 #if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL
1896 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name,
1897 size, DECL_ALIGN (decl));
1898 return true;
1899 #elif defined ASM_OUTPUT_ALIGNED_LOCAL
1900 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl));
1901 return true;
1902 #else
1903 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1904 return false;
1905 #endif
1908 /* A noswitch_section_callback for bss_noswitch_section. */
1910 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
1911 static bool
1912 emit_bss (tree decl ATTRIBUTE_UNUSED,
1913 const char *name ATTRIBUTE_UNUSED,
1914 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1915 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1917 #if defined ASM_OUTPUT_ALIGNED_BSS
1918 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl));
1919 return true;
1920 #else
1921 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded);
1922 return false;
1923 #endif
1925 #endif
1927 /* A noswitch_section_callback for comm_section. */
1929 static bool
1930 emit_common (tree decl ATTRIBUTE_UNUSED,
1931 const char *name ATTRIBUTE_UNUSED,
1932 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1933 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1935 #if defined ASM_OUTPUT_ALIGNED_DECL_COMMON
1936 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name,
1937 size, DECL_ALIGN (decl));
1938 return true;
1939 #elif defined ASM_OUTPUT_ALIGNED_COMMON
1940 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl));
1941 return true;
1942 #else
1943 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded);
1944 return false;
1945 #endif
1948 /* A noswitch_section_callback for tls_comm_section. */
1950 static bool
1951 emit_tls_common (tree decl ATTRIBUTE_UNUSED,
1952 const char *name ATTRIBUTE_UNUSED,
1953 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1954 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1956 #ifdef ASM_OUTPUT_TLS_COMMON
1957 ASM_OUTPUT_TLS_COMMON (asm_out_file, decl, name, size);
1958 return true;
1959 #else
1960 sorry ("thread-local COMMON data not implemented");
1961 return true;
1962 #endif
1965 /* Assemble DECL given that it belongs in SECTION_NOSWITCH section SECT.
1966 NAME is the name of DECL's SYMBOL_REF. */
1968 static void
1969 assemble_noswitch_variable (tree decl, const char *name, section *sect)
1971 unsigned HOST_WIDE_INT size, rounded;
1973 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
1974 rounded = size;
1976 /* Don't allocate zero bytes of common,
1977 since that means "undefined external" in the linker. */
1978 if (size == 0)
1979 rounded = 1;
1981 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1982 so that each uninitialized object starts on such a boundary. */
1983 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
1984 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1985 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1987 if (!sect->noswitch.callback (decl, name, size, rounded)
1988 && (unsigned HOST_WIDE_INT) DECL_ALIGN_UNIT (decl) > rounded)
1989 warning (0, "requested alignment for %q+D is greater than "
1990 "implemented alignment of %wu", decl, rounded);
1993 /* A subroutine of assemble_variable. Output the label and contents of
1994 DECL, whose address is a SYMBOL_REF with name NAME. DONT_OUTPUT_DATA
1995 is as for assemble_variable. */
1997 static void
1998 assemble_variable_contents (tree decl, const char *name,
1999 bool dont_output_data)
2001 /* Do any machine/system dependent processing of the object. */
2002 #ifdef ASM_DECLARE_OBJECT_NAME
2003 last_assemble_variable_decl = decl;
2004 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
2005 #else
2006 /* Standard thing is just output label for the object. */
2007 ASM_OUTPUT_LABEL (asm_out_file, name);
2008 #endif /* ASM_DECLARE_OBJECT_NAME */
2010 if (!dont_output_data)
2012 if (DECL_INITIAL (decl)
2013 && DECL_INITIAL (decl) != error_mark_node
2014 && !initializer_zerop (DECL_INITIAL (decl)))
2015 /* Output the actual data. */
2016 output_constant (DECL_INITIAL (decl),
2017 tree_low_cst (DECL_SIZE_UNIT (decl), 1),
2018 DECL_ALIGN (decl));
2019 else
2020 /* Leave space for it. */
2021 assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1));
2025 /* Initialize emulated tls object TO, which refers to TLS variable
2026 DECL and is initialized by PROXY. */
2028 tree
2029 default_emutls_var_init (tree to, tree decl, tree proxy)
2031 VEC(constructor_elt,gc) *v = VEC_alloc (constructor_elt, gc, 4);
2032 constructor_elt *elt;
2033 tree type = TREE_TYPE (to);
2034 tree field = TYPE_FIELDS (type);
2036 elt = VEC_quick_push (constructor_elt, v, NULL);
2037 elt->index = field;
2038 elt->value = fold_convert (TREE_TYPE (field), DECL_SIZE_UNIT (decl));
2040 elt = VEC_quick_push (constructor_elt, v, NULL);
2041 field = TREE_CHAIN (field);
2042 elt->index = field;
2043 elt->value = build_int_cst (TREE_TYPE (field),
2044 DECL_ALIGN_UNIT (decl));
2046 elt = VEC_quick_push (constructor_elt, v, NULL);
2047 field = TREE_CHAIN (field);
2048 elt->index = field;
2049 elt->value = null_pointer_node;
2051 elt = VEC_quick_push (constructor_elt, v, NULL);
2052 field = TREE_CHAIN (field);
2053 elt->index = field;
2054 elt->value = proxy;
2056 return build_constructor (type, v);
2059 /* Assemble everything that is needed for a variable or function declaration.
2060 Not used for automatic variables, and not used for function definitions.
2061 Should not be called for variables of incomplete structure type.
2063 TOP_LEVEL is nonzero if this variable has file scope.
2064 AT_END is nonzero if this is the special handling, at end of compilation,
2065 to define things that have had only tentative definitions.
2066 DONT_OUTPUT_DATA if nonzero means don't actually output the
2067 initial value (that will be done by the caller). */
2069 void
2070 assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED,
2071 int at_end ATTRIBUTE_UNUSED, int dont_output_data)
2073 const char *name;
2074 rtx decl_rtl, symbol;
2075 section *sect;
2077 if (! targetm.have_tls
2078 && TREE_CODE (decl) == VAR_DECL
2079 && DECL_THREAD_LOCAL_P (decl))
2081 tree to = emutls_decl (decl);
2083 /* If this variable is defined locally, then we need to initialize the
2084 control structure with size and alignment information. We do this
2085 at the last moment because tentative definitions can take a locally
2086 defined but uninitialized variable and initialize it later, which
2087 would result in incorrect contents. */
2088 if (! DECL_EXTERNAL (to)
2089 && (! DECL_COMMON (to)
2090 || (DECL_INITIAL (decl)
2091 && DECL_INITIAL (decl) != error_mark_node)))
2093 DECL_INITIAL (to) = targetm.emutls.var_init
2094 (to, decl, get_emutls_init_templ_addr (decl));
2096 /* Make sure the template is marked as needed early enough.
2097 Without this, if the variable is placed in a
2098 section-anchored block, the template will only be marked
2099 when it's too late. */
2100 record_references_in_initializer (to, false);
2103 decl = to;
2106 last_assemble_variable_decl = 0;
2108 /* Normally no need to say anything here for external references,
2109 since assemble_external is called by the language-specific code
2110 when a declaration is first seen. */
2112 if (DECL_EXTERNAL (decl))
2113 return;
2115 /* Output no assembler code for a function declaration.
2116 Only definitions of functions output anything. */
2118 if (TREE_CODE (decl) == FUNCTION_DECL)
2119 return;
2121 /* Do nothing for global register variables. */
2122 if (DECL_RTL_SET_P (decl) && REG_P (DECL_RTL (decl)))
2124 TREE_ASM_WRITTEN (decl) = 1;
2125 return;
2128 /* If type was incomplete when the variable was declared,
2129 see if it is complete now. */
2131 if (DECL_SIZE (decl) == 0)
2132 layout_decl (decl, 0);
2134 /* Still incomplete => don't allocate it; treat the tentative defn
2135 (which is what it must have been) as an `extern' reference. */
2137 if (!dont_output_data && DECL_SIZE (decl) == 0)
2139 error ("storage size of %q+D isn%'t known", decl);
2140 TREE_ASM_WRITTEN (decl) = 1;
2141 return;
2144 /* The first declaration of a variable that comes through this function
2145 decides whether it is global (in C, has external linkage)
2146 or local (in C, has internal linkage). So do nothing more
2147 if this function has already run. */
2149 if (TREE_ASM_WRITTEN (decl))
2150 return;
2152 /* Make sure targetm.encode_section_info is invoked before we set
2153 ASM_WRITTEN. */
2154 decl_rtl = DECL_RTL (decl);
2156 TREE_ASM_WRITTEN (decl) = 1;
2158 /* Do no output if -fsyntax-only. */
2159 if (flag_syntax_only)
2160 return;
2162 app_disable ();
2164 if (! dont_output_data
2165 && ! host_integerp (DECL_SIZE_UNIT (decl), 1))
2167 error ("size of variable %q+D is too large", decl);
2168 return;
2171 gcc_assert (MEM_P (decl_rtl));
2172 gcc_assert (GET_CODE (XEXP (decl_rtl, 0)) == SYMBOL_REF);
2173 symbol = XEXP (decl_rtl, 0);
2174 name = XSTR (symbol, 0);
2175 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
2176 notice_global_symbol (decl);
2178 /* Compute the alignment of this data. */
2180 align_variable (decl, dont_output_data);
2181 set_mem_align (decl_rtl, DECL_ALIGN (decl));
2183 if (TREE_PUBLIC (decl))
2184 maybe_assemble_visibility (decl);
2186 if (DECL_PRESERVE_P (decl))
2187 targetm.asm_out.mark_decl_preserved (name);
2189 /* First make the assembler name(s) global if appropriate. */
2190 sect = get_variable_section (decl, false);
2191 if (TREE_PUBLIC (decl)
2192 && (sect->common.flags & SECTION_COMMON) == 0)
2193 globalize_decl (decl);
2195 /* Output any data that we will need to use the address of. */
2196 if (DECL_INITIAL (decl) && DECL_INITIAL (decl) != error_mark_node)
2197 output_addressed_constants (DECL_INITIAL (decl));
2199 /* dbxout.c needs to know this. */
2200 if (sect && (sect->common.flags & SECTION_CODE) != 0)
2201 DECL_IN_TEXT_SECTION (decl) = 1;
2203 /* If the decl is part of an object_block, make sure that the decl
2204 has been positioned within its block, but do not write out its
2205 definition yet. output_object_blocks will do that later. */
2206 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
2208 gcc_assert (!dont_output_data);
2209 place_block_symbol (symbol);
2211 else if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
2212 assemble_noswitch_variable (decl, name, sect);
2213 else
2215 switch_to_section (sect);
2216 if (DECL_ALIGN (decl) > BITS_PER_UNIT)
2217 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (DECL_ALIGN_UNIT (decl)));
2218 assemble_variable_contents (decl, name, dont_output_data);
2222 /* Return 1 if type TYPE contains any pointers. */
2224 static int
2225 contains_pointers_p (tree type)
2227 switch (TREE_CODE (type))
2229 case POINTER_TYPE:
2230 case REFERENCE_TYPE:
2231 /* I'm not sure whether OFFSET_TYPE needs this treatment,
2232 so I'll play safe and return 1. */
2233 case OFFSET_TYPE:
2234 return 1;
2236 case RECORD_TYPE:
2237 case UNION_TYPE:
2238 case QUAL_UNION_TYPE:
2240 tree fields;
2241 /* For a type that has fields, see if the fields have pointers. */
2242 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2243 if (TREE_CODE (fields) == FIELD_DECL
2244 && contains_pointers_p (TREE_TYPE (fields)))
2245 return 1;
2246 return 0;
2249 case ARRAY_TYPE:
2250 /* An array type contains pointers if its element type does. */
2251 return contains_pointers_p (TREE_TYPE (type));
2253 default:
2254 return 0;
2258 /* We delay assemble_external processing until
2259 the compilation unit is finalized. This is the best we can do for
2260 right now (i.e. stage 3 of GCC 4.0) - the right thing is to delay
2261 it all the way to final. See PR 17982 for further discussion. */
2262 static GTY(()) tree pending_assemble_externals;
2264 #ifdef ASM_OUTPUT_EXTERNAL
2265 /* True if DECL is a function decl for which no out-of-line copy exists.
2266 It is assumed that DECL's assembler name has been set. */
2268 static bool
2269 incorporeal_function_p (tree decl)
2271 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
2273 const char *name;
2275 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
2276 && DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA)
2277 return true;
2279 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
2280 if (is_builtin_name (name))
2281 return true;
2283 return false;
2286 /* Actually do the tests to determine if this is necessary, and invoke
2287 ASM_OUTPUT_EXTERNAL. */
2288 static void
2289 assemble_external_real (tree decl)
2291 rtx rtl = DECL_RTL (decl);
2293 if (MEM_P (rtl) && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
2294 && !SYMBOL_REF_USED (XEXP (rtl, 0))
2295 && !incorporeal_function_p (decl))
2297 /* Some systems do require some output. */
2298 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
2299 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
2302 #endif
2304 void
2305 process_pending_assemble_externals (void)
2307 #ifdef ASM_OUTPUT_EXTERNAL
2308 tree list;
2309 for (list = pending_assemble_externals; list; list = TREE_CHAIN (list))
2310 assemble_external_real (TREE_VALUE (list));
2312 pending_assemble_externals = 0;
2313 #endif
2316 /* This TREE_LIST contains any weak symbol declarations waiting
2317 to be emitted. */
2318 static GTY(()) tree weak_decls;
2320 /* Output something to declare an external symbol to the assembler,
2321 and qualifiers such as weakness. (Most assemblers don't need
2322 extern declaration, so we normally output nothing.) Do nothing if
2323 DECL is not external. */
2325 void
2326 assemble_external (tree decl ATTRIBUTE_UNUSED)
2328 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the
2329 main body of this code is only rarely exercised. To provide some
2330 testing, on all platforms, we make sure that the ASM_OUT_FILE is
2331 open. If it's not, we should not be calling this function. */
2332 gcc_assert (asm_out_file);
2334 if (!DECL_P (decl) || !DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl))
2335 return;
2337 /* We want to output annotation for weak and external symbols at
2338 very last to check if they are references or not. */
2340 if (SUPPORTS_WEAK && DECL_WEAK (decl)
2341 /* TREE_STATIC is a weird and abused creature which is not
2342 generally the right test for whether an entity has been
2343 locally emitted, inlined or otherwise not-really-extern, but
2344 for declarations that can be weak, it happens to be
2345 match. */
2346 && !TREE_STATIC (decl)
2347 && value_member (decl, weak_decls) == NULL_TREE)
2348 weak_decls = tree_cons (NULL, decl, weak_decls);
2350 #ifdef ASM_OUTPUT_EXTERNAL
2351 if (value_member (decl, pending_assemble_externals) == NULL_TREE)
2352 pending_assemble_externals = tree_cons (NULL, decl,
2353 pending_assemble_externals);
2354 #endif
2357 /* Similar, for calling a library function FUN. */
2359 void
2360 assemble_external_libcall (rtx fun)
2362 /* Declare library function name external when first used, if nec. */
2363 if (! SYMBOL_REF_USED (fun))
2365 SYMBOL_REF_USED (fun) = 1;
2366 targetm.asm_out.external_libcall (fun);
2370 /* Assemble a label named NAME. */
2372 void
2373 assemble_label (const char *name)
2375 ASM_OUTPUT_LABEL (asm_out_file, name);
2378 /* Set the symbol_referenced flag for ID. */
2379 void
2380 mark_referenced (tree id)
2382 TREE_SYMBOL_REFERENCED (id) = 1;
2385 /* Set the symbol_referenced flag for DECL and notify callgraph. */
2386 void
2387 mark_decl_referenced (tree decl)
2389 if (TREE_CODE (decl) == FUNCTION_DECL)
2391 /* Extern inline functions don't become needed when referenced.
2392 If we know a method will be emitted in other TU and no new
2393 functions can be marked reachable, just use the external
2394 definition. */
2395 struct cgraph_node *node = cgraph_node (decl);
2396 if (!DECL_EXTERNAL (decl)
2397 && (!node->local.vtable_method || !cgraph_global_info_ready
2398 || !node->local.finalized))
2399 cgraph_mark_needed_node (node);
2401 else if (TREE_CODE (decl) == VAR_DECL)
2403 struct varpool_node *node = varpool_node (decl);
2404 varpool_mark_needed_node (node);
2405 /* C++ frontend use mark_decl_references to force COMDAT variables
2406 to be output that might appear dead otherwise. */
2407 node->force_output = true;
2409 /* else do nothing - we can get various sorts of CST nodes here,
2410 which do not need to be marked. */
2414 /* Follow the IDENTIFIER_TRANSPARENT_ALIAS chain starting at *ALIAS
2415 until we find an identifier that is not itself a transparent alias.
2416 Modify the alias passed to it by reference (and all aliases on the
2417 way to the ultimate target), such that they do not have to be
2418 followed again, and return the ultimate target of the alias
2419 chain. */
2421 static inline tree
2422 ultimate_transparent_alias_target (tree *alias)
2424 tree target = *alias;
2426 if (IDENTIFIER_TRANSPARENT_ALIAS (target))
2428 gcc_assert (TREE_CHAIN (target));
2429 target = ultimate_transparent_alias_target (&TREE_CHAIN (target));
2430 gcc_assert (! IDENTIFIER_TRANSPARENT_ALIAS (target)
2431 && ! TREE_CHAIN (target));
2432 *alias = target;
2435 return target;
2438 /* Output to FILE (an assembly file) a reference to NAME. If NAME
2439 starts with a *, the rest of NAME is output verbatim. Otherwise
2440 NAME is transformed in a target-specific way (usually by the
2441 addition of an underscore). */
2443 void
2444 assemble_name_raw (FILE *file, const char *name)
2446 if (name[0] == '*')
2447 fputs (&name[1], file);
2448 else
2449 ASM_OUTPUT_LABELREF (file, name);
2452 /* Like assemble_name_raw, but should be used when NAME might refer to
2453 an entity that is also represented as a tree (like a function or
2454 variable). If NAME does refer to such an entity, that entity will
2455 be marked as referenced. */
2457 void
2458 assemble_name (FILE *file, const char *name)
2460 const char *real_name;
2461 tree id;
2463 real_name = targetm.strip_name_encoding (name);
2465 id = maybe_get_identifier (real_name);
2466 if (id)
2468 tree id_orig = id;
2470 mark_referenced (id);
2471 ultimate_transparent_alias_target (&id);
2472 if (id != id_orig)
2473 name = IDENTIFIER_POINTER (id);
2474 gcc_assert (! TREE_CHAIN (id));
2477 assemble_name_raw (file, name);
2480 /* Allocate SIZE bytes writable static space with a gensym name
2481 and return an RTX to refer to its address. */
2484 assemble_static_space (unsigned HOST_WIDE_INT size)
2486 char name[12];
2487 const char *namestring;
2488 rtx x;
2490 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
2491 ++const_labelno;
2492 namestring = ggc_strdup (name);
2494 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
2495 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL;
2497 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
2498 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
2499 BIGGEST_ALIGNMENT);
2500 #else
2501 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
2502 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
2503 #else
2505 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
2506 so that each uninitialized object starts on such a boundary. */
2507 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */
2508 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED
2509 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
2510 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
2511 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
2512 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
2514 #endif
2515 #endif
2516 return x;
2519 /* Assemble the static constant template for function entry trampolines.
2520 This is done at most once per compilation.
2521 Returns an RTX for the address of the template. */
2523 static GTY(()) rtx initial_trampoline;
2526 assemble_trampoline_template (void)
2528 char label[256];
2529 const char *name;
2530 int align;
2531 rtx symbol;
2533 gcc_assert (targetm.asm_out.trampoline_template != NULL);
2535 if (initial_trampoline)
2536 return initial_trampoline;
2538 /* By default, put trampoline templates in read-only data section. */
2540 #ifdef TRAMPOLINE_SECTION
2541 switch_to_section (TRAMPOLINE_SECTION);
2542 #else
2543 switch_to_section (readonly_data_section);
2544 #endif
2546 /* Write the assembler code to define one. */
2547 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
2548 if (align > 0)
2549 ASM_OUTPUT_ALIGN (asm_out_file, align);
2551 targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0);
2552 targetm.asm_out.trampoline_template (asm_out_file);
2554 /* Record the rtl to refer to it. */
2555 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
2556 name = ggc_strdup (label);
2557 symbol = gen_rtx_SYMBOL_REF (Pmode, name);
2558 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2560 initial_trampoline = gen_const_mem (BLKmode, symbol);
2561 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
2562 set_mem_size (initial_trampoline, GEN_INT (TRAMPOLINE_SIZE));
2564 return initial_trampoline;
2567 /* A and B are either alignments or offsets. Return the minimum alignment
2568 that may be assumed after adding the two together. */
2570 static inline unsigned
2571 min_align (unsigned int a, unsigned int b)
2573 return (a | b) & -(a | b);
2576 /* Return the assembler directive for creating a given kind of integer
2577 object. SIZE is the number of bytes in the object and ALIGNED_P
2578 indicates whether it is known to be aligned. Return NULL if the
2579 assembly dialect has no such directive.
2581 The returned string should be printed at the start of a new line and
2582 be followed immediately by the object's initial value. */
2584 const char *
2585 integer_asm_op (int size, int aligned_p)
2587 struct asm_int_op *ops;
2589 if (aligned_p)
2590 ops = &targetm.asm_out.aligned_op;
2591 else
2592 ops = &targetm.asm_out.unaligned_op;
2594 switch (size)
2596 case 1:
2597 return targetm.asm_out.byte_op;
2598 case 2:
2599 return ops->hi;
2600 case 4:
2601 return ops->si;
2602 case 8:
2603 return ops->di;
2604 case 16:
2605 return ops->ti;
2606 default:
2607 return NULL;
2611 /* Use directive OP to assemble an integer object X. Print OP at the
2612 start of the line, followed immediately by the value of X. */
2614 void
2615 assemble_integer_with_op (const char *op, rtx x)
2617 fputs (op, asm_out_file);
2618 output_addr_const (asm_out_file, x);
2619 fputc ('\n', asm_out_file);
2622 /* The default implementation of the asm_out.integer target hook. */
2624 bool
2625 default_assemble_integer (rtx x ATTRIBUTE_UNUSED,
2626 unsigned int size ATTRIBUTE_UNUSED,
2627 int aligned_p ATTRIBUTE_UNUSED)
2629 const char *op = integer_asm_op (size, aligned_p);
2630 /* Avoid GAS bugs for large values. Specifically negative values whose
2631 absolute value fits in a bfd_vma, but not in a bfd_signed_vma. */
2632 if (size > UNITS_PER_WORD && size > POINTER_SIZE / BITS_PER_UNIT)
2633 return false;
2634 return op && (assemble_integer_with_op (op, x), true);
2637 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
2638 the alignment of the integer in bits. Return 1 if we were able to output
2639 the constant, otherwise 0. We must be able to output the constant,
2640 if FORCE is nonzero. */
2642 bool
2643 assemble_integer (rtx x, unsigned int size, unsigned int align, int force)
2645 int aligned_p;
2647 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT));
2649 /* See if the target hook can handle this kind of object. */
2650 if (targetm.asm_out.integer (x, size, aligned_p))
2651 return true;
2653 /* If the object is a multi-byte one, try splitting it up. Split
2654 it into words it if is multi-word, otherwise split it into bytes. */
2655 if (size > 1)
2657 enum machine_mode omode, imode;
2658 unsigned int subalign;
2659 unsigned int subsize, i;
2660 enum mode_class mclass;
2662 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1;
2663 subalign = MIN (align, subsize * BITS_PER_UNIT);
2664 if (GET_CODE (x) == CONST_FIXED)
2665 mclass = GET_MODE_CLASS (GET_MODE (x));
2666 else
2667 mclass = MODE_INT;
2669 omode = mode_for_size (subsize * BITS_PER_UNIT, mclass, 0);
2670 imode = mode_for_size (size * BITS_PER_UNIT, mclass, 0);
2672 for (i = 0; i < size; i += subsize)
2674 rtx partial = simplify_subreg (omode, x, imode, i);
2675 if (!partial || !assemble_integer (partial, subsize, subalign, 0))
2676 break;
2678 if (i == size)
2679 return true;
2681 /* If we've printed some of it, but not all of it, there's no going
2682 back now. */
2683 gcc_assert (!i);
2686 gcc_assert (!force);
2688 return false;
2691 void
2692 assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align)
2694 long data[4] = {0, 0, 0, 0};
2695 int i;
2696 int bitsize, nelts, nunits, units_per;
2698 /* This is hairy. We have a quantity of known size. real_to_target
2699 will put it into an array of *host* longs, 32 bits per element
2700 (even if long is more than 32 bits). We need to determine the
2701 number of array elements that are occupied (nelts) and the number
2702 of *target* min-addressable units that will be occupied in the
2703 object file (nunits). We cannot assume that 32 divides the
2704 mode's bitsize (size * BITS_PER_UNIT) evenly.
2706 size * BITS_PER_UNIT is used here to make sure that padding bits
2707 (which might appear at either end of the value; real_to_target
2708 will include the padding bits in its output array) are included. */
2710 nunits = GET_MODE_SIZE (mode);
2711 bitsize = nunits * BITS_PER_UNIT;
2712 nelts = CEIL (bitsize, 32);
2713 units_per = 32 / BITS_PER_UNIT;
2715 real_to_target (data, &d, mode);
2717 /* Put out the first word with the specified alignment. */
2718 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1);
2719 nunits -= units_per;
2721 /* Subsequent words need only 32-bit alignment. */
2722 align = min_align (align, 32);
2724 for (i = 1; i < nelts; i++)
2726 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1);
2727 nunits -= units_per;
2731 /* Given an expression EXP with a constant value,
2732 reduce it to the sum of an assembler symbol and an integer.
2733 Store them both in the structure *VALUE.
2734 EXP must be reducible. */
2736 struct GTY(()) addr_const {
2737 rtx base;
2738 HOST_WIDE_INT offset;
2741 static void
2742 decode_addr_const (tree exp, struct addr_const *value)
2744 tree target = TREE_OPERAND (exp, 0);
2745 int offset = 0;
2746 rtx x;
2748 while (1)
2750 if (TREE_CODE (target) == COMPONENT_REF
2751 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0))
2754 offset += int_byte_position (TREE_OPERAND (target, 1));
2755 target = TREE_OPERAND (target, 0);
2757 else if (TREE_CODE (target) == ARRAY_REF
2758 || TREE_CODE (target) == ARRAY_RANGE_REF)
2760 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1)
2761 * tree_low_cst (TREE_OPERAND (target, 1), 0));
2762 target = TREE_OPERAND (target, 0);
2764 else
2765 break;
2768 switch (TREE_CODE (target))
2770 case VAR_DECL:
2771 case FUNCTION_DECL:
2772 x = DECL_RTL (target);
2773 break;
2775 case LABEL_DECL:
2776 x = gen_rtx_MEM (FUNCTION_MODE,
2777 gen_rtx_LABEL_REF (Pmode, force_label_rtx (target)));
2778 break;
2780 case REAL_CST:
2781 case FIXED_CST:
2782 case STRING_CST:
2783 case COMPLEX_CST:
2784 case CONSTRUCTOR:
2785 case INTEGER_CST:
2786 x = output_constant_def (target, 1);
2787 break;
2789 default:
2790 gcc_unreachable ();
2793 gcc_assert (MEM_P (x));
2794 x = XEXP (x, 0);
2796 value->base = x;
2797 value->offset = offset;
2801 static GTY((param_is (struct constant_descriptor_tree)))
2802 htab_t const_desc_htab;
2804 static struct constant_descriptor_tree * build_constant_desc (tree);
2805 static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int);
2807 /* Constant pool accessor function. */
2809 htab_t
2810 constant_pool_htab (void)
2812 return const_desc_htab;
2815 /* Compute a hash code for a constant expression. */
2817 static hashval_t
2818 const_desc_hash (const void *ptr)
2820 return ((const struct constant_descriptor_tree *)ptr)->hash;
2823 static hashval_t
2824 const_hash_1 (const tree exp)
2826 const char *p;
2827 hashval_t hi;
2828 int len, i;
2829 enum tree_code code = TREE_CODE (exp);
2831 /* Either set P and LEN to the address and len of something to hash and
2832 exit the switch or return a value. */
2834 switch (code)
2836 case INTEGER_CST:
2837 p = (char *) &TREE_INT_CST (exp);
2838 len = sizeof TREE_INT_CST (exp);
2839 break;
2841 case REAL_CST:
2842 return real_hash (TREE_REAL_CST_PTR (exp));
2844 case FIXED_CST:
2845 return fixed_hash (TREE_FIXED_CST_PTR (exp));
2847 case STRING_CST:
2848 p = TREE_STRING_POINTER (exp);
2849 len = TREE_STRING_LENGTH (exp);
2850 break;
2852 case COMPLEX_CST:
2853 return (const_hash_1 (TREE_REALPART (exp)) * 5
2854 + const_hash_1 (TREE_IMAGPART (exp)));
2856 case CONSTRUCTOR:
2858 unsigned HOST_WIDE_INT idx;
2859 tree value;
2861 hi = 5 + int_size_in_bytes (TREE_TYPE (exp));
2863 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, value)
2864 if (value)
2865 hi = hi * 603 + const_hash_1 (value);
2867 return hi;
2870 case ADDR_EXPR:
2871 case FDESC_EXPR:
2873 struct addr_const value;
2875 decode_addr_const (exp, &value);
2876 switch (GET_CODE (value.base))
2878 case SYMBOL_REF:
2879 /* Don't hash the address of the SYMBOL_REF;
2880 only use the offset and the symbol name. */
2881 hi = value.offset;
2882 p = XSTR (value.base, 0);
2883 for (i = 0; p[i] != 0; i++)
2884 hi = ((hi * 613) + (unsigned) (p[i]));
2885 break;
2887 case LABEL_REF:
2888 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2889 break;
2891 default:
2892 gcc_unreachable ();
2895 return hi;
2897 case PLUS_EXPR:
2898 case POINTER_PLUS_EXPR:
2899 case MINUS_EXPR:
2900 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9
2901 + const_hash_1 (TREE_OPERAND (exp, 1)));
2903 CASE_CONVERT:
2904 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2;
2906 default:
2907 /* A language specific constant. Just hash the code. */
2908 return code;
2911 /* Compute hashing function. */
2912 hi = len;
2913 for (i = 0; i < len; i++)
2914 hi = ((hi * 613) + (unsigned) (p[i]));
2916 return hi;
2919 /* Wrapper of compare_constant, for the htab interface. */
2920 static int
2921 const_desc_eq (const void *p1, const void *p2)
2923 const struct constant_descriptor_tree *const c1
2924 = (const struct constant_descriptor_tree *) p1;
2925 const struct constant_descriptor_tree *const c2
2926 = (const struct constant_descriptor_tree *) p2;
2927 if (c1->hash != c2->hash)
2928 return 0;
2929 return compare_constant (c1->value, c2->value);
2932 /* Compare t1 and t2, and return 1 only if they are known to result in
2933 the same bit pattern on output. */
2935 static int
2936 compare_constant (const tree t1, const tree t2)
2938 enum tree_code typecode;
2940 if (t1 == NULL_TREE)
2941 return t2 == NULL_TREE;
2942 if (t2 == NULL_TREE)
2943 return 0;
2945 if (TREE_CODE (t1) != TREE_CODE (t2))
2946 return 0;
2948 switch (TREE_CODE (t1))
2950 case INTEGER_CST:
2951 /* Integer constants are the same only if the same width of type. */
2952 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2953 return 0;
2954 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2955 return 0;
2956 return tree_int_cst_equal (t1, t2);
2958 case REAL_CST:
2959 /* Real constants are the same only if the same width of type. */
2960 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2961 return 0;
2963 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2965 case FIXED_CST:
2966 /* Fixed constants are the same only if the same width of type. */
2967 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2968 return 0;
2970 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (t1), TREE_FIXED_CST (t2));
2972 case STRING_CST:
2973 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2974 return 0;
2976 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2977 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2978 TREE_STRING_LENGTH (t1)));
2980 case COMPLEX_CST:
2981 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2))
2982 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2)));
2984 case CONSTRUCTOR:
2986 VEC(constructor_elt, gc) *v1, *v2;
2987 unsigned HOST_WIDE_INT idx;
2989 typecode = TREE_CODE (TREE_TYPE (t1));
2990 if (typecode != TREE_CODE (TREE_TYPE (t2)))
2991 return 0;
2993 if (typecode == ARRAY_TYPE)
2995 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1));
2996 /* For arrays, check that the sizes all match. */
2997 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))
2998 || size_1 == -1
2999 || size_1 != int_size_in_bytes (TREE_TYPE (t2)))
3000 return 0;
3002 else
3004 /* For record and union constructors, require exact type
3005 equality. */
3006 if (TREE_TYPE (t1) != TREE_TYPE (t2))
3007 return 0;
3010 v1 = CONSTRUCTOR_ELTS (t1);
3011 v2 = CONSTRUCTOR_ELTS (t2);
3012 if (VEC_length (constructor_elt, v1)
3013 != VEC_length (constructor_elt, v2))
3014 return 0;
3016 for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx)
3018 constructor_elt *c1 = VEC_index (constructor_elt, v1, idx);
3019 constructor_elt *c2 = VEC_index (constructor_elt, v2, idx);
3021 /* Check that each value is the same... */
3022 if (!compare_constant (c1->value, c2->value))
3023 return 0;
3024 /* ... and that they apply to the same fields! */
3025 if (typecode == ARRAY_TYPE)
3027 if (!compare_constant (c1->index, c2->index))
3028 return 0;
3030 else
3032 if (c1->index != c2->index)
3033 return 0;
3037 return 1;
3040 case ADDR_EXPR:
3041 case FDESC_EXPR:
3043 struct addr_const value1, value2;
3045 decode_addr_const (t1, &value1);
3046 decode_addr_const (t2, &value2);
3047 return (value1.offset == value2.offset
3048 && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0);
3051 case PLUS_EXPR:
3052 case POINTER_PLUS_EXPR:
3053 case MINUS_EXPR:
3054 case RANGE_EXPR:
3055 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
3056 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
3058 CASE_CONVERT:
3059 case VIEW_CONVERT_EXPR:
3060 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3062 default:
3063 return 0;
3066 gcc_unreachable ();
3069 /* Make a copy of the whole tree structure for a constant. This
3070 handles the same types of nodes that compare_constant handles. */
3072 static tree
3073 copy_constant (tree exp)
3075 switch (TREE_CODE (exp))
3077 case ADDR_EXPR:
3078 /* For ADDR_EXPR, we do not want to copy the decl whose address
3079 is requested. We do want to copy constants though. */
3080 if (CONSTANT_CLASS_P (TREE_OPERAND (exp, 0)))
3081 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
3082 copy_constant (TREE_OPERAND (exp, 0)));
3083 else
3084 return copy_node (exp);
3086 case INTEGER_CST:
3087 case REAL_CST:
3088 case FIXED_CST:
3089 case STRING_CST:
3090 return copy_node (exp);
3092 case COMPLEX_CST:
3093 return build_complex (TREE_TYPE (exp),
3094 copy_constant (TREE_REALPART (exp)),
3095 copy_constant (TREE_IMAGPART (exp)));
3097 case PLUS_EXPR:
3098 case POINTER_PLUS_EXPR:
3099 case MINUS_EXPR:
3100 return build2 (TREE_CODE (exp), TREE_TYPE (exp),
3101 copy_constant (TREE_OPERAND (exp, 0)),
3102 copy_constant (TREE_OPERAND (exp, 1)));
3104 CASE_CONVERT:
3105 case VIEW_CONVERT_EXPR:
3106 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
3107 copy_constant (TREE_OPERAND (exp, 0)));
3109 case CONSTRUCTOR:
3111 tree copy = copy_node (exp);
3112 VEC(constructor_elt, gc) *v;
3113 unsigned HOST_WIDE_INT idx;
3114 tree purpose, value;
3116 v = VEC_alloc(constructor_elt, gc, VEC_length(constructor_elt,
3117 CONSTRUCTOR_ELTS (exp)));
3118 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (exp), idx, purpose, value)
3120 constructor_elt *ce = VEC_quick_push (constructor_elt, v, NULL);
3121 ce->index = purpose;
3122 ce->value = copy_constant (value);
3124 CONSTRUCTOR_ELTS (copy) = v;
3125 return copy;
3128 default:
3129 gcc_unreachable ();
3133 /* Return the alignment of constant EXP in bits. */
3135 static unsigned int
3136 get_constant_alignment (tree exp)
3138 unsigned int align;
3140 align = TYPE_ALIGN (TREE_TYPE (exp));
3141 #ifdef CONSTANT_ALIGNMENT
3142 align = CONSTANT_ALIGNMENT (exp, align);
3143 #endif
3144 return align;
3147 /* Return the section into which constant EXP should be placed. */
3149 static section *
3150 get_constant_section (tree exp)
3152 if (IN_NAMED_SECTION (exp))
3153 return get_named_section (exp, NULL, compute_reloc_for_constant (exp));
3154 else
3155 return targetm.asm_out.select_section (exp,
3156 compute_reloc_for_constant (exp),
3157 get_constant_alignment (exp));
3160 /* Return the size of constant EXP in bytes. */
3162 static HOST_WIDE_INT
3163 get_constant_size (tree exp)
3165 HOST_WIDE_INT size;
3167 size = int_size_in_bytes (TREE_TYPE (exp));
3168 if (TREE_CODE (exp) == STRING_CST)
3169 size = MAX (TREE_STRING_LENGTH (exp), size);
3170 return size;
3173 /* Subroutine of output_constant_def:
3174 No constant equal to EXP is known to have been output.
3175 Make a constant descriptor to enter EXP in the hash table.
3176 Assign the label number and construct RTL to refer to the
3177 constant's location in memory.
3178 Caller is responsible for updating the hash table. */
3180 static struct constant_descriptor_tree *
3181 build_constant_desc (tree exp)
3183 rtx symbol;
3184 rtx rtl;
3185 char label[256];
3186 int labelno;
3187 struct constant_descriptor_tree *desc;
3189 desc = GGC_NEW (struct constant_descriptor_tree);
3190 desc->value = copy_constant (exp);
3192 /* Propagate marked-ness to copied constant. */
3193 if (flag_mudflap && mf_marked_p (exp))
3194 mf_mark (desc->value);
3196 /* Create a string containing the label name, in LABEL. */
3197 labelno = const_labelno++;
3198 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno);
3200 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
3201 if (use_object_blocks_p ())
3203 section *sect = get_constant_section (exp);
3204 symbol = create_block_symbol (ggc_strdup (label),
3205 get_block_for_section (sect), -1);
3207 else
3208 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3209 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3210 SET_SYMBOL_REF_DECL (symbol, desc->value);
3211 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3213 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol);
3214 set_mem_attributes (rtl, exp, 1);
3215 set_mem_alias_set (rtl, 0);
3216 set_mem_alias_set (rtl, const_alias_set);
3218 /* We cannot share RTX'es in pool entries.
3219 Mark this piece of RTL as required for unsharing. */
3220 RTX_FLAG (rtl, used) = 1;
3222 /* Set flags or add text to the name to record information, such as
3223 that it is a local symbol. If the name is changed, the macro
3224 ASM_OUTPUT_LABELREF will have to know how to strip this
3225 information. This call might invalidate our local variable
3226 SYMBOL; we can't use it afterward. */
3228 targetm.encode_section_info (exp, rtl, true);
3230 desc->rtl = rtl;
3232 return desc;
3235 /* Return an rtx representing a reference to constant data in memory
3236 for the constant expression EXP.
3238 If assembler code for such a constant has already been output,
3239 return an rtx to refer to it.
3240 Otherwise, output such a constant in memory
3241 and generate an rtx for it.
3243 If DEFER is nonzero, this constant can be deferred and output only
3244 if referenced in the function after all optimizations.
3246 `const_desc_table' records which constants already have label strings. */
3249 output_constant_def (tree exp, int defer)
3251 struct constant_descriptor_tree *desc;
3252 struct constant_descriptor_tree key;
3253 void **loc;
3255 /* Look up EXP in the table of constant descriptors. If we didn't find
3256 it, create a new one. */
3257 key.value = exp;
3258 key.hash = const_hash_1 (exp);
3259 loc = htab_find_slot_with_hash (const_desc_htab, &key, key.hash, INSERT);
3261 desc = (struct constant_descriptor_tree *) *loc;
3262 if (desc == 0)
3264 desc = build_constant_desc (exp);
3265 desc->hash = key.hash;
3266 *loc = desc;
3269 maybe_output_constant_def_contents (desc, defer);
3270 return desc->rtl;
3273 /* Subroutine of output_constant_def: Decide whether or not we need to
3274 output the constant DESC now, and if so, do it. */
3275 static void
3276 maybe_output_constant_def_contents (struct constant_descriptor_tree *desc,
3277 int defer)
3279 rtx symbol = XEXP (desc->rtl, 0);
3280 tree exp = desc->value;
3282 if (flag_syntax_only)
3283 return;
3285 if (TREE_ASM_WRITTEN (exp))
3286 /* Already output; don't do it again. */
3287 return;
3289 /* We can always defer constants as long as the context allows
3290 doing so. */
3291 if (defer)
3293 /* Increment n_deferred_constants if it exists. It needs to be at
3294 least as large as the number of constants actually referred to
3295 by the function. If it's too small we'll stop looking too early
3296 and fail to emit constants; if it's too large we'll only look
3297 through the entire function when we could have stopped earlier. */
3298 if (cfun)
3299 n_deferred_constants++;
3300 return;
3303 output_constant_def_contents (symbol);
3306 /* Subroutine of output_constant_def_contents. Output the definition
3307 of constant EXP, which is pointed to by label LABEL. ALIGN is the
3308 constant's alignment in bits. */
3310 static void
3311 assemble_constant_contents (tree exp, const char *label, unsigned int align)
3313 HOST_WIDE_INT size;
3315 size = get_constant_size (exp);
3317 /* Do any machine/system dependent processing of the constant. */
3318 #ifdef ASM_DECLARE_CONSTANT_NAME
3319 ASM_DECLARE_CONSTANT_NAME (asm_out_file, label, exp, size);
3320 #else
3321 /* Standard thing is just output label for the constant. */
3322 ASM_OUTPUT_LABEL (asm_out_file, label);
3323 #endif /* ASM_DECLARE_CONSTANT_NAME */
3325 /* Output the value of EXP. */
3326 output_constant (exp, size, align);
3329 /* We must output the constant data referred to by SYMBOL; do so. */
3331 static void
3332 output_constant_def_contents (rtx symbol)
3334 tree exp = SYMBOL_REF_DECL (symbol);
3335 unsigned int align;
3337 /* Make sure any other constants whose addresses appear in EXP
3338 are assigned label numbers. */
3339 output_addressed_constants (exp);
3341 /* We are no longer deferring this constant. */
3342 TREE_ASM_WRITTEN (exp) = 1;
3344 /* If the constant is part of an object block, make sure that the
3345 decl has been positioned within its block, but do not write out
3346 its definition yet. output_object_blocks will do that later. */
3347 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
3348 place_block_symbol (symbol);
3349 else
3351 switch_to_section (get_constant_section (exp));
3352 align = get_constant_alignment (exp);
3353 if (align > BITS_PER_UNIT)
3354 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
3355 assemble_constant_contents (exp, XSTR (symbol, 0), align);
3357 if (flag_mudflap)
3358 mudflap_enqueue_constant (exp);
3361 /* Look up EXP in the table of constant descriptors. Return the rtl
3362 if it has been emitted, else null. */
3365 lookup_constant_def (tree exp)
3367 struct constant_descriptor_tree *desc;
3368 struct constant_descriptor_tree key;
3370 key.value = exp;
3371 key.hash = const_hash_1 (exp);
3372 desc = (struct constant_descriptor_tree *)
3373 htab_find_with_hash (const_desc_htab, &key, key.hash);
3375 return (desc ? desc->rtl : NULL_RTX);
3378 /* Used in the hash tables to avoid outputting the same constant
3379 twice. Unlike 'struct constant_descriptor_tree', RTX constants
3380 are output once per function, not once per file. */
3381 /* ??? Only a few targets need per-function constant pools. Most
3382 can use one per-file pool. Should add a targetm bit to tell the
3383 difference. */
3385 struct GTY(()) rtx_constant_pool {
3386 /* Pointers to first and last constant in pool, as ordered by offset. */
3387 struct constant_descriptor_rtx *first;
3388 struct constant_descriptor_rtx *last;
3390 /* Hash facility for making memory-constants from constant rtl-expressions.
3391 It is used on RISC machines where immediate integer arguments and
3392 constant addresses are restricted so that such constants must be stored
3393 in memory. */
3394 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab;
3396 /* Current offset in constant pool (does not include any
3397 machine-specific header). */
3398 HOST_WIDE_INT offset;
3401 struct GTY((chain_next ("%h.next"))) constant_descriptor_rtx {
3402 struct constant_descriptor_rtx *next;
3403 rtx mem;
3404 rtx sym;
3405 rtx constant;
3406 HOST_WIDE_INT offset;
3407 hashval_t hash;
3408 enum machine_mode mode;
3409 unsigned int align;
3410 int labelno;
3411 int mark;
3414 /* Hash and compare functions for const_rtx_htab. */
3416 static hashval_t
3417 const_desc_rtx_hash (const void *ptr)
3419 const struct constant_descriptor_rtx *const desc
3420 = (const struct constant_descriptor_rtx *) ptr;
3421 return desc->hash;
3424 static int
3425 const_desc_rtx_eq (const void *a, const void *b)
3427 const struct constant_descriptor_rtx *const x
3428 = (const struct constant_descriptor_rtx *) a;
3429 const struct constant_descriptor_rtx *const y
3430 = (const struct constant_descriptor_rtx *) b;
3432 if (x->mode != y->mode)
3433 return 0;
3434 return rtx_equal_p (x->constant, y->constant);
3437 /* This is the worker function for const_rtx_hash, called via for_each_rtx. */
3439 static int
3440 const_rtx_hash_1 (rtx *xp, void *data)
3442 unsigned HOST_WIDE_INT hwi;
3443 enum machine_mode mode;
3444 enum rtx_code code;
3445 hashval_t h, *hp;
3446 rtx x;
3448 x = *xp;
3449 code = GET_CODE (x);
3450 mode = GET_MODE (x);
3451 h = (hashval_t) code * 1048573 + mode;
3453 switch (code)
3455 case CONST_INT:
3456 hwi = INTVAL (x);
3457 fold_hwi:
3459 int shift = sizeof (hashval_t) * CHAR_BIT;
3460 const int n = sizeof (HOST_WIDE_INT) / sizeof (hashval_t);
3461 int i;
3463 h ^= (hashval_t) hwi;
3464 for (i = 1; i < n; ++i)
3466 hwi >>= shift;
3467 h ^= (hashval_t) hwi;
3470 break;
3472 case CONST_DOUBLE:
3473 if (mode == VOIDmode)
3475 hwi = CONST_DOUBLE_LOW (x) ^ CONST_DOUBLE_HIGH (x);
3476 goto fold_hwi;
3478 else
3479 h ^= real_hash (CONST_DOUBLE_REAL_VALUE (x));
3480 break;
3482 case CONST_FIXED:
3483 h ^= fixed_hash (CONST_FIXED_VALUE (x));
3484 break;
3486 case CONST_VECTOR:
3488 int i;
3489 for (i = XVECLEN (x, 0); i-- > 0; )
3490 h = h * 251 + const_rtx_hash_1 (&XVECEXP (x, 0, i), data);
3492 break;
3494 case SYMBOL_REF:
3495 h ^= htab_hash_string (XSTR (x, 0));
3496 break;
3498 case LABEL_REF:
3499 h = h * 251 + CODE_LABEL_NUMBER (XEXP (x, 0));
3500 break;
3502 case UNSPEC:
3503 case UNSPEC_VOLATILE:
3504 h = h * 251 + XINT (x, 1);
3505 break;
3507 default:
3508 break;
3511 hp = (hashval_t *) data;
3512 *hp = *hp * 509 + h;
3513 return 0;
3516 /* Compute a hash value for X, which should be a constant. */
3518 static hashval_t
3519 const_rtx_hash (rtx x)
3521 hashval_t h = 0;
3522 for_each_rtx (&x, const_rtx_hash_1, &h);
3523 return h;
3527 /* Create and return a new rtx constant pool. */
3529 static struct rtx_constant_pool *
3530 create_constant_pool (void)
3532 struct rtx_constant_pool *pool;
3534 pool = GGC_NEW (struct rtx_constant_pool);
3535 pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash,
3536 const_desc_rtx_eq, NULL);
3537 pool->first = NULL;
3538 pool->last = NULL;
3539 pool->offset = 0;
3540 return pool;
3543 /* Initialize constant pool hashing for a new function. */
3545 void
3546 init_varasm_status (void)
3548 crtl->varasm.pool = create_constant_pool ();
3549 crtl->varasm.deferred_constants = 0;
3552 /* Given a MINUS expression, simplify it if both sides
3553 include the same symbol. */
3556 simplify_subtraction (rtx x)
3558 rtx r = simplify_rtx (x);
3559 return r ? r : x;
3562 /* Given a constant rtx X, make (or find) a memory constant for its value
3563 and return a MEM rtx to refer to it in memory. */
3566 force_const_mem (enum machine_mode mode, rtx x)
3568 struct constant_descriptor_rtx *desc, tmp;
3569 struct rtx_constant_pool *pool;
3570 char label[256];
3571 rtx def, symbol;
3572 hashval_t hash;
3573 unsigned int align;
3574 void **slot;
3576 /* If we're not allowed to drop X into the constant pool, don't. */
3577 if (targetm.cannot_force_const_mem (x))
3578 return NULL_RTX;
3580 /* Record that this function has used a constant pool entry. */
3581 crtl->uses_const_pool = 1;
3583 /* Decide which pool to use. */
3584 pool = (targetm.use_blocks_for_constant_p (mode, x)
3585 ? shared_constant_pool
3586 : crtl->varasm.pool);
3588 /* Lookup the value in the hashtable. */
3589 tmp.constant = x;
3590 tmp.mode = mode;
3591 hash = const_rtx_hash (x);
3592 slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT);
3593 desc = (struct constant_descriptor_rtx *) *slot;
3595 /* If the constant was already present, return its memory. */
3596 if (desc)
3597 return copy_rtx (desc->mem);
3599 /* Otherwise, create a new descriptor. */
3600 desc = GGC_NEW (struct constant_descriptor_rtx);
3601 *slot = desc;
3603 /* Align the location counter as required by EXP's data type. */
3604 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode);
3605 #ifdef CONSTANT_ALIGNMENT
3607 tree type = lang_hooks.types.type_for_mode (mode, 0);
3608 if (type != NULL_TREE)
3609 align = CONSTANT_ALIGNMENT (make_tree (type, x), align);
3611 #endif
3613 pool->offset += (align / BITS_PER_UNIT) - 1;
3614 pool->offset &= ~ ((align / BITS_PER_UNIT) - 1);
3616 desc->next = NULL;
3617 desc->constant = tmp.constant;
3618 desc->offset = pool->offset;
3619 desc->hash = hash;
3620 desc->mode = mode;
3621 desc->align = align;
3622 desc->labelno = const_labelno;
3623 desc->mark = 0;
3625 pool->offset += GET_MODE_SIZE (mode);
3626 if (pool->last)
3627 pool->last->next = desc;
3628 else
3629 pool->first = pool->last = desc;
3630 pool->last = desc;
3632 /* Create a string containing the label name, in LABEL. */
3633 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
3634 ++const_labelno;
3636 /* Construct the SYMBOL_REF. Make sure to mark it as belonging to
3637 the constants pool. */
3638 if (use_object_blocks_p () && targetm.use_blocks_for_constant_p (mode, x))
3640 section *sect = targetm.asm_out.select_rtx_section (mode, x, align);
3641 symbol = create_block_symbol (ggc_strdup (label),
3642 get_block_for_section (sect), -1);
3644 else
3645 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3646 desc->sym = symbol;
3647 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3648 CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3649 SET_SYMBOL_REF_CONSTANT (symbol, desc);
3651 /* Construct the MEM. */
3652 desc->mem = def = gen_const_mem (mode, symbol);
3653 set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1);
3654 set_mem_align (def, align);
3656 /* If we're dropping a label to the constant pool, make sure we
3657 don't delete it. */
3658 if (GET_CODE (x) == LABEL_REF)
3659 LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
3661 return copy_rtx (def);
3664 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
3667 get_pool_constant (rtx addr)
3669 return SYMBOL_REF_CONSTANT (addr)->constant;
3672 /* Given a constant pool SYMBOL_REF, return the corresponding constant
3673 and whether it has been output or not. */
3676 get_pool_constant_mark (rtx addr, bool *pmarked)
3678 struct constant_descriptor_rtx *desc;
3680 desc = SYMBOL_REF_CONSTANT (addr);
3681 *pmarked = (desc->mark != 0);
3682 return desc->constant;
3685 /* Similar, return the mode. */
3687 enum machine_mode
3688 get_pool_mode (const_rtx addr)
3690 return SYMBOL_REF_CONSTANT (addr)->mode;
3693 /* Return the size of the constant pool. */
3696 get_pool_size (void)
3698 return crtl->varasm.pool->offset;
3701 /* Worker function for output_constant_pool_1. Emit assembly for X
3702 in MODE with known alignment ALIGN. */
3704 static void
3705 output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align)
3707 switch (GET_MODE_CLASS (mode))
3709 case MODE_FLOAT:
3710 case MODE_DECIMAL_FLOAT:
3712 REAL_VALUE_TYPE r;
3714 gcc_assert (GET_CODE (x) == CONST_DOUBLE);
3715 REAL_VALUE_FROM_CONST_DOUBLE (r, x);
3716 assemble_real (r, mode, align);
3717 break;
3720 case MODE_INT:
3721 case MODE_PARTIAL_INT:
3722 case MODE_FRACT:
3723 case MODE_UFRACT:
3724 case MODE_ACCUM:
3725 case MODE_UACCUM:
3726 assemble_integer (x, GET_MODE_SIZE (mode), align, 1);
3727 break;
3729 case MODE_VECTOR_FLOAT:
3730 case MODE_VECTOR_INT:
3731 case MODE_VECTOR_FRACT:
3732 case MODE_VECTOR_UFRACT:
3733 case MODE_VECTOR_ACCUM:
3734 case MODE_VECTOR_UACCUM:
3736 int i, units;
3737 enum machine_mode submode = GET_MODE_INNER (mode);
3738 unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode));
3740 gcc_assert (GET_CODE (x) == CONST_VECTOR);
3741 units = CONST_VECTOR_NUNITS (x);
3743 for (i = 0; i < units; i++)
3745 rtx elt = CONST_VECTOR_ELT (x, i);
3746 output_constant_pool_2 (submode, elt, i ? subalign : align);
3749 break;
3751 default:
3752 gcc_unreachable ();
3756 /* Worker function for output_constant_pool. Emit constant DESC,
3757 giving it ALIGN bits of alignment. */
3759 static void
3760 output_constant_pool_1 (struct constant_descriptor_rtx *desc,
3761 unsigned int align)
3763 rtx x, tmp;
3765 x = desc->constant;
3767 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3768 whose CODE_LABEL has been deleted. This can occur if a jump table
3769 is eliminated by optimization. If so, write a constant of zero
3770 instead. Note that this can also happen by turning the
3771 CODE_LABEL into a NOTE. */
3772 /* ??? This seems completely and utterly wrong. Certainly it's
3773 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper
3774 functioning even with INSN_DELETED_P and friends. */
3776 tmp = x;
3777 switch (GET_CODE (tmp))
3779 case CONST:
3780 if (GET_CODE (XEXP (tmp, 0)) != PLUS
3781 || GET_CODE (XEXP (XEXP (tmp, 0), 0)) != LABEL_REF)
3782 break;
3783 tmp = XEXP (XEXP (tmp, 0), 0);
3784 /* FALLTHRU */
3786 case LABEL_REF:
3787 tmp = XEXP (tmp, 0);
3788 gcc_assert (!INSN_DELETED_P (tmp));
3789 gcc_assert (!NOTE_P (tmp)
3790 || NOTE_KIND (tmp) != NOTE_INSN_DELETED);
3791 break;
3793 default:
3794 break;
3797 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3798 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode,
3799 align, desc->labelno, done);
3800 #endif
3802 assemble_align (align);
3804 /* Output the label. */
3805 targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno);
3807 /* Output the data. */
3808 output_constant_pool_2 (desc->mode, x, align);
3810 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS
3811 sections have proper size. */
3812 if (align > GET_MODE_BITSIZE (desc->mode)
3813 && in_section
3814 && (in_section->common.flags & SECTION_MERGE))
3815 assemble_align (align);
3817 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3818 done:
3819 #endif
3820 return;
3823 /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
3824 to as used. Emit referenced deferred strings. This function can
3825 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */
3827 static int
3828 mark_constant (rtx *current_rtx, void *data ATTRIBUTE_UNUSED)
3830 rtx x = *current_rtx;
3832 if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF)
3833 return 0;
3835 if (CONSTANT_POOL_ADDRESS_P (x))
3837 struct constant_descriptor_rtx *desc = SYMBOL_REF_CONSTANT (x);
3838 if (desc->mark == 0)
3840 desc->mark = 1;
3841 for_each_rtx (&desc->constant, mark_constant, NULL);
3844 else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
3846 tree exp = SYMBOL_REF_DECL (x);
3847 if (!TREE_ASM_WRITTEN (exp))
3849 n_deferred_constants--;
3850 output_constant_def_contents (x);
3854 return -1;
3857 /* Look through appropriate parts of INSN, marking all entries in the
3858 constant pool which are actually being used. Entries that are only
3859 referenced by other constants are also marked as used. Emit
3860 deferred strings that are used. */
3862 static void
3863 mark_constants (rtx insn)
3865 if (!INSN_P (insn))
3866 return;
3868 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3869 insns, not any notes that may be attached. We don't want to mark
3870 a constant just because it happens to appear in a REG_EQUIV note. */
3871 if (GET_CODE (PATTERN (insn)) == SEQUENCE)
3873 rtx seq = PATTERN (insn);
3874 int i, n = XVECLEN (seq, 0);
3875 for (i = 0; i < n; ++i)
3877 rtx subinsn = XVECEXP (seq, 0, i);
3878 if (INSN_P (subinsn))
3879 for_each_rtx (&PATTERN (subinsn), mark_constant, NULL);
3882 else
3883 for_each_rtx (&PATTERN (insn), mark_constant, NULL);
3886 /* Look through the instructions for this function, and mark all the
3887 entries in POOL which are actually being used. Emit deferred constants
3888 which have indeed been used. */
3890 static void
3891 mark_constant_pool (void)
3893 rtx insn, link;
3895 if (!crtl->uses_const_pool && n_deferred_constants == 0)
3896 return;
3898 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3899 mark_constants (insn);
3901 for (link = crtl->epilogue_delay_list;
3902 link;
3903 link = XEXP (link, 1))
3904 mark_constants (XEXP (link, 0));
3907 /* Write all the constants in POOL. */
3909 static void
3910 output_constant_pool_contents (struct rtx_constant_pool *pool)
3912 struct constant_descriptor_rtx *desc;
3914 for (desc = pool->first; desc ; desc = desc->next)
3915 if (desc->mark)
3917 /* If the constant is part of an object_block, make sure that
3918 the constant has been positioned within its block, but do not
3919 write out its definition yet. output_object_blocks will do
3920 that later. */
3921 if (SYMBOL_REF_HAS_BLOCK_INFO_P (desc->sym)
3922 && SYMBOL_REF_BLOCK (desc->sym))
3923 place_block_symbol (desc->sym);
3924 else
3926 switch_to_section (targetm.asm_out.select_rtx_section
3927 (desc->mode, desc->constant, desc->align));
3928 output_constant_pool_1 (desc, desc->align);
3933 /* Mark all constants that are used in the current function, then write
3934 out the function's private constant pool. */
3936 static void
3937 output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
3938 tree fndecl ATTRIBUTE_UNUSED)
3940 struct rtx_constant_pool *pool = crtl->varasm.pool;
3942 /* It is possible for gcc to call force_const_mem and then to later
3943 discard the instructions which refer to the constant. In such a
3944 case we do not need to output the constant. */
3945 mark_constant_pool ();
3947 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3948 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset);
3949 #endif
3951 output_constant_pool_contents (pool);
3953 #ifdef ASM_OUTPUT_POOL_EPILOGUE
3954 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset);
3955 #endif
3958 /* Write the contents of the shared constant pool. */
3960 void
3961 output_shared_constant_pool (void)
3963 output_constant_pool_contents (shared_constant_pool);
3966 /* Determine what kind of relocations EXP may need. */
3969 compute_reloc_for_constant (tree exp)
3971 int reloc = 0, reloc2;
3972 tree tem;
3974 switch (TREE_CODE (exp))
3976 case ADDR_EXPR:
3977 case FDESC_EXPR:
3978 /* Go inside any operations that get_inner_reference can handle and see
3979 if what's inside is a constant: no need to do anything here for
3980 addresses of variables or functions. */
3981 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3982 tem = TREE_OPERAND (tem, 0))
3985 if (TREE_PUBLIC (tem))
3986 reloc |= 2;
3987 else
3988 reloc |= 1;
3989 break;
3991 case PLUS_EXPR:
3992 case POINTER_PLUS_EXPR:
3993 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3994 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3995 break;
3997 case MINUS_EXPR:
3998 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3999 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1));
4000 /* The difference of two local labels is computable at link time. */
4001 if (reloc == 1 && reloc2 == 1)
4002 reloc = 0;
4003 else
4004 reloc |= reloc2;
4005 break;
4007 CASE_CONVERT:
4008 case VIEW_CONVERT_EXPR:
4009 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
4010 break;
4012 case CONSTRUCTOR:
4014 unsigned HOST_WIDE_INT idx;
4015 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
4016 if (tem != 0)
4017 reloc |= compute_reloc_for_constant (tem);
4019 break;
4021 default:
4022 break;
4024 return reloc;
4027 /* Find all the constants whose addresses are referenced inside of EXP,
4028 and make sure assembler code with a label has been output for each one.
4029 Indicate whether an ADDR_EXPR has been encountered. */
4031 static void
4032 output_addressed_constants (tree exp)
4034 tree tem;
4036 switch (TREE_CODE (exp))
4038 case ADDR_EXPR:
4039 case FDESC_EXPR:
4040 /* Go inside any operations that get_inner_reference can handle and see
4041 if what's inside is a constant: no need to do anything here for
4042 addresses of variables or functions. */
4043 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
4044 tem = TREE_OPERAND (tem, 0))
4047 /* If we have an initialized CONST_DECL, retrieve the initializer. */
4048 if (TREE_CODE (tem) == CONST_DECL && DECL_INITIAL (tem))
4049 tem = DECL_INITIAL (tem);
4051 if (CONSTANT_CLASS_P (tem) || TREE_CODE (tem) == CONSTRUCTOR)
4052 output_constant_def (tem, 0);
4053 break;
4055 case PLUS_EXPR:
4056 case POINTER_PLUS_EXPR:
4057 case MINUS_EXPR:
4058 output_addressed_constants (TREE_OPERAND (exp, 1));
4059 /* Fall through. */
4061 CASE_CONVERT:
4062 case VIEW_CONVERT_EXPR:
4063 output_addressed_constants (TREE_OPERAND (exp, 0));
4064 break;
4066 case CONSTRUCTOR:
4068 unsigned HOST_WIDE_INT idx;
4069 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
4070 if (tem != 0)
4071 output_addressed_constants (tem);
4073 break;
4075 default:
4076 break;
4080 /* Whether a constructor CTOR is a valid static constant initializer if all
4081 its elements are. This used to be internal to initializer_constant_valid_p
4082 and has been exposed to let other functions like categorize_ctor_elements
4083 evaluate the property while walking a constructor for other purposes. */
4085 bool
4086 constructor_static_from_elts_p (const_tree ctor)
4088 return (TREE_CONSTANT (ctor)
4089 && (TREE_CODE (TREE_TYPE (ctor)) == UNION_TYPE
4090 || TREE_CODE (TREE_TYPE (ctor)) == RECORD_TYPE)
4091 && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (ctor)));
4094 /* A subroutine of initializer_constant_valid_p. VALUE is a MINUS_EXPR,
4095 PLUS_EXPR or POINTER_PLUS_EXPR. This looks for cases of VALUE
4096 which are valid when ENDTYPE is an integer of any size; in
4097 particular, this does not accept a pointer minus a constant. This
4098 returns null_pointer_node if the VALUE is an absolute constant
4099 which can be used to initialize a static variable. Otherwise it
4100 returns NULL. */
4102 static tree
4103 narrowing_initializer_constant_valid_p (tree value, tree endtype)
4105 tree op0, op1;
4107 if (!INTEGRAL_TYPE_P (endtype))
4108 return NULL_TREE;
4110 op0 = TREE_OPERAND (value, 0);
4111 op1 = TREE_OPERAND (value, 1);
4113 /* Like STRIP_NOPS except allow the operand mode to widen. This
4114 works around a feature of fold that simplifies (int)(p1 - p2) to
4115 ((int)p1 - (int)p2) under the theory that the narrower operation
4116 is cheaper. */
4118 while (CONVERT_EXPR_P (op0)
4119 || TREE_CODE (op0) == NON_LVALUE_EXPR)
4121 tree inner = TREE_OPERAND (op0, 0);
4122 if (inner == error_mark_node
4123 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4124 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))
4125 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4126 break;
4127 op0 = inner;
4130 while (CONVERT_EXPR_P (op1)
4131 || TREE_CODE (op1) == NON_LVALUE_EXPR)
4133 tree inner = TREE_OPERAND (op1, 0);
4134 if (inner == error_mark_node
4135 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4136 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))
4137 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4138 break;
4139 op1 = inner;
4142 op0 = initializer_constant_valid_p (op0, endtype);
4143 op1 = initializer_constant_valid_p (op1, endtype);
4145 /* Both initializers must be known. */
4146 if (op0 && op1)
4148 if (op0 == op1
4149 && (op0 == null_pointer_node
4150 || TREE_CODE (value) == MINUS_EXPR))
4151 return null_pointer_node;
4153 /* Support differences between labels. */
4154 if (TREE_CODE (op0) == LABEL_DECL
4155 && TREE_CODE (op1) == LABEL_DECL)
4156 return null_pointer_node;
4158 if (TREE_CODE (op0) == STRING_CST
4159 && TREE_CODE (op1) == STRING_CST
4160 && operand_equal_p (op0, op1, 1))
4161 return null_pointer_node;
4164 return NULL_TREE;
4167 /* Return nonzero if VALUE is a valid constant-valued expression
4168 for use in initializing a static variable; one that can be an
4169 element of a "constant" initializer.
4171 Return null_pointer_node if the value is absolute;
4172 if it is relocatable, return the variable that determines the relocation.
4173 We assume that VALUE has been folded as much as possible;
4174 therefore, we do not need to check for such things as
4175 arithmetic-combinations of integers. */
4177 tree
4178 initializer_constant_valid_p (tree value, tree endtype)
4180 tree ret;
4182 switch (TREE_CODE (value))
4184 case CONSTRUCTOR:
4185 if (constructor_static_from_elts_p (value))
4187 unsigned HOST_WIDE_INT idx;
4188 tree elt;
4189 bool absolute = true;
4191 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
4193 tree reloc;
4194 reloc = initializer_constant_valid_p (elt, TREE_TYPE (elt));
4195 if (!reloc)
4196 return NULL_TREE;
4197 if (reloc != null_pointer_node)
4198 absolute = false;
4200 /* For a non-absolute relocation, there is no single
4201 variable that can be "the variable that determines the
4202 relocation." */
4203 return absolute ? null_pointer_node : error_mark_node;
4206 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE;
4208 case INTEGER_CST:
4209 case VECTOR_CST:
4210 case REAL_CST:
4211 case FIXED_CST:
4212 case STRING_CST:
4213 case COMPLEX_CST:
4214 return null_pointer_node;
4216 case ADDR_EXPR:
4217 case FDESC_EXPR:
4219 tree op0 = staticp (TREE_OPERAND (value, 0));
4220 if (op0)
4222 /* "&(*a).f" is like unto pointer arithmetic. If "a" turns out
4223 to be a constant, this is old-skool offsetof-like nonsense. */
4224 if (TREE_CODE (op0) == INDIRECT_REF
4225 && TREE_CONSTANT (TREE_OPERAND (op0, 0)))
4226 return null_pointer_node;
4227 /* Taking the address of a nested function involves a trampoline,
4228 unless we don't need or want one. */
4229 if (TREE_CODE (op0) == FUNCTION_DECL
4230 && DECL_STATIC_CHAIN (op0)
4231 && !TREE_NO_TRAMPOLINE (value))
4232 return NULL_TREE;
4233 /* "&{...}" requires a temporary to hold the constructed
4234 object. */
4235 if (TREE_CODE (op0) == CONSTRUCTOR)
4236 return NULL_TREE;
4238 return op0;
4241 case NON_LVALUE_EXPR:
4242 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
4244 case VIEW_CONVERT_EXPR:
4246 tree src = TREE_OPERAND (value, 0);
4247 tree src_type = TREE_TYPE (src);
4248 tree dest_type = TREE_TYPE (value);
4250 /* Allow view-conversions from aggregate to non-aggregate type only
4251 if the bit pattern is fully preserved afterwards; otherwise, the
4252 RTL expander won't be able to apply a subsequent transformation
4253 to the underlying constructor. */
4254 if (AGGREGATE_TYPE_P (src_type) && !AGGREGATE_TYPE_P (dest_type))
4256 if (TYPE_MODE (endtype) == TYPE_MODE (dest_type))
4257 return initializer_constant_valid_p (src, endtype);
4258 else
4259 return NULL_TREE;
4262 /* Allow all other kinds of view-conversion. */
4263 return initializer_constant_valid_p (src, endtype);
4266 CASE_CONVERT:
4268 tree src = TREE_OPERAND (value, 0);
4269 tree src_type = TREE_TYPE (src);
4270 tree dest_type = TREE_TYPE (value);
4272 /* Allow conversions between pointer types, floating-point
4273 types, and offset types. */
4274 if ((POINTER_TYPE_P (dest_type) && POINTER_TYPE_P (src_type))
4275 || (FLOAT_TYPE_P (dest_type) && FLOAT_TYPE_P (src_type))
4276 || (TREE_CODE (dest_type) == OFFSET_TYPE
4277 && TREE_CODE (src_type) == OFFSET_TYPE))
4278 return initializer_constant_valid_p (src, endtype);
4280 /* Allow length-preserving conversions between integer types. */
4281 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type)
4282 && (TYPE_PRECISION (dest_type) == TYPE_PRECISION (src_type)))
4283 return initializer_constant_valid_p (src, endtype);
4285 /* Allow conversions between other integer types only if
4286 explicit value. */
4287 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type))
4289 tree inner = initializer_constant_valid_p (src, endtype);
4290 if (inner == null_pointer_node)
4291 return null_pointer_node;
4292 break;
4295 /* Allow (int) &foo provided int is as wide as a pointer. */
4296 if (INTEGRAL_TYPE_P (dest_type) && POINTER_TYPE_P (src_type)
4297 && (TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type)))
4298 return initializer_constant_valid_p (src, endtype);
4300 /* Likewise conversions from int to pointers, but also allow
4301 conversions from 0. */
4302 if ((POINTER_TYPE_P (dest_type)
4303 || TREE_CODE (dest_type) == OFFSET_TYPE)
4304 && INTEGRAL_TYPE_P (src_type))
4306 if (TREE_CODE (src) == INTEGER_CST
4307 && TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type))
4308 return null_pointer_node;
4309 if (integer_zerop (src))
4310 return null_pointer_node;
4311 else if (TYPE_PRECISION (dest_type) <= TYPE_PRECISION (src_type))
4312 return initializer_constant_valid_p (src, endtype);
4315 /* Allow conversions to struct or union types if the value
4316 inside is okay. */
4317 if (TREE_CODE (dest_type) == RECORD_TYPE
4318 || TREE_CODE (dest_type) == UNION_TYPE)
4319 return initializer_constant_valid_p (src, endtype);
4321 break;
4323 case POINTER_PLUS_EXPR:
4324 case PLUS_EXPR:
4325 /* Any valid floating-point constants will have been folded by now;
4326 with -frounding-math we hit this with addition of two constants. */
4327 if (TREE_CODE (endtype) == REAL_TYPE)
4328 return NULL_TREE;
4329 if (! INTEGRAL_TYPE_P (endtype)
4330 || TYPE_PRECISION (endtype)
4331 >= int_or_pointer_precision (TREE_TYPE (value)))
4333 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
4334 endtype);
4335 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
4336 endtype);
4337 /* If either term is absolute, use the other term's relocation. */
4338 if (valid0 == null_pointer_node)
4339 return valid1;
4340 if (valid1 == null_pointer_node)
4341 return valid0;
4344 /* Support narrowing pointer differences. */
4345 ret = narrowing_initializer_constant_valid_p (value, endtype);
4346 if (ret != NULL_TREE)
4347 return ret;
4349 break;
4351 case MINUS_EXPR:
4352 if (TREE_CODE (endtype) == REAL_TYPE)
4353 return NULL_TREE;
4354 if (! INTEGRAL_TYPE_P (endtype)
4355 || TYPE_PRECISION (endtype)
4356 >= int_or_pointer_precision (TREE_TYPE (value)))
4358 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
4359 endtype);
4360 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
4361 endtype);
4362 /* Win if second argument is absolute. */
4363 if (valid1 == null_pointer_node)
4364 return valid0;
4365 /* Win if both arguments have the same relocation.
4366 Then the value is absolute. */
4367 if (valid0 == valid1 && valid0 != 0)
4368 return null_pointer_node;
4370 /* Since GCC guarantees that string constants are unique in the
4371 generated code, a subtraction between two copies of the same
4372 constant string is absolute. */
4373 if (valid0 && TREE_CODE (valid0) == STRING_CST
4374 && valid1 && TREE_CODE (valid1) == STRING_CST
4375 && operand_equal_p (valid0, valid1, 1))
4376 return null_pointer_node;
4379 /* Support narrowing differences. */
4380 ret = narrowing_initializer_constant_valid_p (value, endtype);
4381 if (ret != NULL_TREE)
4382 return ret;
4384 break;
4386 default:
4387 break;
4390 return 0;
4393 /* Return true if VALUE is a valid constant-valued expression
4394 for use in initializing a static bit-field; one that can be
4395 an element of a "constant" initializer. */
4397 bool
4398 initializer_constant_valid_for_bitfield_p (tree value)
4400 /* For bitfields we support integer constants or possibly nested aggregates
4401 of such. */
4402 switch (TREE_CODE (value))
4404 case CONSTRUCTOR:
4406 unsigned HOST_WIDE_INT idx;
4407 tree elt;
4409 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
4410 if (!initializer_constant_valid_for_bitfield_p (elt))
4411 return false;
4412 return true;
4415 case INTEGER_CST:
4416 return true;
4418 case VIEW_CONVERT_EXPR:
4419 case NON_LVALUE_EXPR:
4420 return
4421 initializer_constant_valid_for_bitfield_p (TREE_OPERAND (value, 0));
4423 default:
4424 break;
4427 return false;
4430 /* output_constructor outer state of relevance in recursive calls, typically
4431 for nested aggregate bitfields. */
4433 typedef struct {
4434 unsigned int bit_offset; /* current position in ... */
4435 int byte; /* ... the outer byte buffer. */
4436 } oc_outer_state;
4438 static unsigned HOST_WIDE_INT
4439 output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int,
4440 oc_outer_state *);
4442 /* Output assembler code for constant EXP to FILE, with no label.
4443 This includes the pseudo-op such as ".int" or ".byte", and a newline.
4444 Assumes output_addressed_constants has been done on EXP already.
4446 Generate exactly SIZE bytes of assembler data, padding at the end
4447 with zeros if necessary. SIZE must always be specified.
4449 SIZE is important for structure constructors,
4450 since trailing members may have been omitted from the constructor.
4451 It is also important for initialization of arrays from string constants
4452 since the full length of the string constant might not be wanted.
4453 It is also needed for initialization of unions, where the initializer's
4454 type is just one member, and that may not be as long as the union.
4456 There a case in which we would fail to output exactly SIZE bytes:
4457 for a structure constructor that wants to produce more than SIZE bytes.
4458 But such constructors will never be generated for any possible input.
4460 ALIGN is the alignment of the data in bits. */
4462 void
4463 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
4465 enum tree_code code;
4466 unsigned HOST_WIDE_INT thissize;
4468 if (size == 0 || flag_syntax_only)
4469 return;
4471 /* See if we're trying to initialize a pointer in a non-default mode
4472 to the address of some declaration somewhere. If the target says
4473 the mode is valid for pointers, assume the target has a way of
4474 resolving it. */
4475 if (TREE_CODE (exp) == NOP_EXPR
4476 && POINTER_TYPE_P (TREE_TYPE (exp))
4477 && targetm.addr_space.valid_pointer_mode
4478 (TYPE_MODE (TREE_TYPE (exp)),
4479 TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (exp)))))
4481 tree saved_type = TREE_TYPE (exp);
4483 /* Peel off any intermediate conversions-to-pointer for valid
4484 pointer modes. */
4485 while (TREE_CODE (exp) == NOP_EXPR
4486 && POINTER_TYPE_P (TREE_TYPE (exp))
4487 && targetm.addr_space.valid_pointer_mode
4488 (TYPE_MODE (TREE_TYPE (exp)),
4489 TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (exp)))))
4490 exp = TREE_OPERAND (exp, 0);
4492 /* If what we're left with is the address of something, we can
4493 convert the address to the final type and output it that
4494 way. */
4495 if (TREE_CODE (exp) == ADDR_EXPR)
4496 exp = build1 (ADDR_EXPR, saved_type, TREE_OPERAND (exp, 0));
4497 /* Likewise for constant ints. */
4498 else if (TREE_CODE (exp) == INTEGER_CST)
4499 exp = build_int_cst_wide (saved_type, TREE_INT_CST_LOW (exp),
4500 TREE_INT_CST_HIGH (exp));
4504 /* Eliminate any conversions since we'll be outputting the underlying
4505 constant. */
4506 while (CONVERT_EXPR_P (exp)
4507 || TREE_CODE (exp) == NON_LVALUE_EXPR
4508 || TREE_CODE (exp) == VIEW_CONVERT_EXPR)
4510 HOST_WIDE_INT type_size = int_size_in_bytes (TREE_TYPE (exp));
4511 HOST_WIDE_INT op_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (exp, 0)));
4513 /* Make sure eliminating the conversion is really a no-op, except with
4514 VIEW_CONVERT_EXPRs to allow for wild Ada unchecked conversions and
4515 union types to allow for Ada unchecked unions. */
4516 if (type_size > op_size
4517 && TREE_CODE (exp) != VIEW_CONVERT_EXPR
4518 && TREE_CODE (TREE_TYPE (exp)) != UNION_TYPE)
4519 /* Keep the conversion. */
4520 break;
4521 else
4522 exp = TREE_OPERAND (exp, 0);
4525 code = TREE_CODE (TREE_TYPE (exp));
4526 thissize = int_size_in_bytes (TREE_TYPE (exp));
4528 /* Allow a constructor with no elements for any data type.
4529 This means to fill the space with zeros. */
4530 if (TREE_CODE (exp) == CONSTRUCTOR
4531 && VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (exp)))
4533 assemble_zeros (size);
4534 return;
4537 if (TREE_CODE (exp) == FDESC_EXPR)
4539 #ifdef ASM_OUTPUT_FDESC
4540 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0);
4541 tree decl = TREE_OPERAND (exp, 0);
4542 ASM_OUTPUT_FDESC (asm_out_file, decl, part);
4543 #else
4544 gcc_unreachable ();
4545 #endif
4546 return;
4549 /* Now output the underlying data. If we've handling the padding, return.
4550 Otherwise, break and ensure SIZE is the size written. */
4551 switch (code)
4553 case BOOLEAN_TYPE:
4554 case INTEGER_TYPE:
4555 case ENUMERAL_TYPE:
4556 case POINTER_TYPE:
4557 case REFERENCE_TYPE:
4558 case OFFSET_TYPE:
4559 case FIXED_POINT_TYPE:
4560 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
4561 EXPAND_INITIALIZER),
4562 MIN (size, thissize), align, 0))
4563 error ("initializer for integer/fixed-point value is too complicated");
4564 break;
4566 case REAL_TYPE:
4567 if (TREE_CODE (exp) != REAL_CST)
4568 error ("initializer for floating value is not a floating constant");
4569 else
4570 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
4571 break;
4573 case COMPLEX_TYPE:
4574 output_constant (TREE_REALPART (exp), thissize / 2, align);
4575 output_constant (TREE_IMAGPART (exp), thissize / 2,
4576 min_align (align, BITS_PER_UNIT * (thissize / 2)));
4577 break;
4579 case ARRAY_TYPE:
4580 case VECTOR_TYPE:
4581 switch (TREE_CODE (exp))
4583 case CONSTRUCTOR:
4584 output_constructor (exp, size, align, NULL);
4585 return;
4586 case STRING_CST:
4587 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp),
4588 size);
4589 assemble_string (TREE_STRING_POINTER (exp), thissize);
4590 break;
4592 case VECTOR_CST:
4594 int elt_size;
4595 tree link;
4596 unsigned int nalign;
4597 enum machine_mode inner;
4599 inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp)));
4600 nalign = MIN (align, GET_MODE_ALIGNMENT (inner));
4602 elt_size = GET_MODE_SIZE (inner);
4604 link = TREE_VECTOR_CST_ELTS (exp);
4605 output_constant (TREE_VALUE (link), elt_size, align);
4606 thissize = elt_size;
4607 while ((link = TREE_CHAIN (link)) != NULL)
4609 output_constant (TREE_VALUE (link), elt_size, nalign);
4610 thissize += elt_size;
4612 break;
4614 default:
4615 gcc_unreachable ();
4617 break;
4619 case RECORD_TYPE:
4620 case UNION_TYPE:
4621 gcc_assert (TREE_CODE (exp) == CONSTRUCTOR);
4622 output_constructor (exp, size, align, NULL);
4623 return;
4625 case ERROR_MARK:
4626 return;
4628 default:
4629 gcc_unreachable ();
4632 if (size > thissize)
4633 assemble_zeros (size - thissize);
4637 /* Subroutine of output_constructor, used for computing the size of
4638 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array
4639 type with an unspecified upper bound. */
4641 static unsigned HOST_WIDE_INT
4642 array_size_for_constructor (tree val)
4644 tree max_index, i;
4645 unsigned HOST_WIDE_INT cnt;
4646 tree index, value, tmp;
4648 /* This code used to attempt to handle string constants that are not
4649 arrays of single-bytes, but nothing else does, so there's no point in
4650 doing it here. */
4651 if (TREE_CODE (val) == STRING_CST)
4652 return TREE_STRING_LENGTH (val);
4654 max_index = NULL_TREE;
4655 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (val), cnt, index, value)
4657 if (TREE_CODE (index) == RANGE_EXPR)
4658 index = TREE_OPERAND (index, 1);
4659 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index))
4660 max_index = index;
4663 if (max_index == NULL_TREE)
4664 return 0;
4666 /* Compute the total number of array elements. */
4667 tmp = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val)));
4668 i = size_binop (MINUS_EXPR, fold_convert (sizetype, max_index),
4669 fold_convert (sizetype, tmp));
4670 i = size_binop (PLUS_EXPR, i, build_int_cst (sizetype, 1));
4672 /* Multiply by the array element unit size to find number of bytes. */
4673 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val))));
4675 return tree_low_cst (i, 1);
4678 /* Other datastructures + helpers for output_constructor. */
4680 /* output_constructor local state to support interaction with helpers. */
4682 typedef struct {
4684 /* Received arguments. */
4685 tree exp; /* Constructor expression. */
4686 unsigned HOST_WIDE_INT size; /* # bytes to output - pad if necessary. */
4687 unsigned int align; /* Known initial alignment. */
4689 /* Constructor expression data. */
4690 tree type; /* Expression type. */
4691 tree field; /* Current field decl in a record. */
4692 tree min_index; /* Lower bound if specified for an array. */
4694 /* Output processing state. */
4695 HOST_WIDE_INT total_bytes; /* # bytes output so far / current position. */
4696 bool byte_buffer_in_use; /* Whether byte ... */
4697 int byte; /* ... contains part of a bitfield byte yet to
4698 be output. */
4700 int last_relative_index; /* Implicit or explicit index of the last
4701 array element output within a bitfield. */
4702 /* Current element. */
4703 tree val; /* Current element value. */
4704 tree index; /* Current element index. */
4706 } oc_local_state;
4708 /* Helper for output_constructor. From the current LOCAL state, output a
4709 RANGE_EXPR element. */
4711 static void
4712 output_constructor_array_range (oc_local_state *local)
4714 unsigned HOST_WIDE_INT fieldsize
4715 = int_size_in_bytes (TREE_TYPE (local->type));
4717 HOST_WIDE_INT lo_index
4718 = tree_low_cst (TREE_OPERAND (local->index, 0), 0);
4719 HOST_WIDE_INT hi_index
4720 = tree_low_cst (TREE_OPERAND (local->index, 1), 0);
4721 HOST_WIDE_INT index;
4723 unsigned int align2
4724 = min_align (local->align, fieldsize * BITS_PER_UNIT);
4726 for (index = lo_index; index <= hi_index; index++)
4728 /* Output the element's initial value. */
4729 if (local->val == NULL_TREE)
4730 assemble_zeros (fieldsize);
4731 else
4732 output_constant (local->val, fieldsize, align2);
4734 /* Count its size. */
4735 local->total_bytes += fieldsize;
4739 /* Helper for output_constructor. From the current LOCAL state, output a
4740 field element that is not true bitfield or part of an outer one. */
4742 static void
4743 output_constructor_regular_field (oc_local_state *local)
4745 /* Field size and position. Since this structure is static, we know the
4746 positions are constant. */
4747 unsigned HOST_WIDE_INT fieldsize;
4748 HOST_WIDE_INT fieldpos;
4750 unsigned int align2;
4752 if (local->index != NULL_TREE)
4753 fieldpos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (local->val)), 1)
4754 * ((tree_low_cst (local->index, 0)
4755 - tree_low_cst (local->min_index, 0))));
4756 else if (local->field != NULL_TREE)
4757 fieldpos = int_byte_position (local->field);
4758 else
4759 fieldpos = 0;
4761 /* Output any buffered-up bit-fields preceding this element. */
4762 if (local->byte_buffer_in_use)
4764 assemble_integer (GEN_INT (local->byte), 1, BITS_PER_UNIT, 1);
4765 local->total_bytes++;
4766 local->byte_buffer_in_use = false;
4769 /* Advance to offset of this element.
4770 Note no alignment needed in an array, since that is guaranteed
4771 if each element has the proper size. */
4772 if ((local->field != NULL_TREE || local->index != NULL_TREE)
4773 && fieldpos != local->total_bytes)
4775 gcc_assert (fieldpos >= local->total_bytes);
4776 assemble_zeros (fieldpos - local->total_bytes);
4777 local->total_bytes = fieldpos;
4780 /* Find the alignment of this element. */
4781 align2 = min_align (local->align, BITS_PER_UNIT * fieldpos);
4783 /* Determine size this element should occupy. */
4784 if (local->field)
4786 fieldsize = 0;
4788 /* If this is an array with an unspecified upper bound,
4789 the initializer determines the size. */
4790 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL,
4791 but we cannot do this until the deprecated support for
4792 initializing zero-length array members is removed. */
4793 if (TREE_CODE (TREE_TYPE (local->field)) == ARRAY_TYPE
4794 && TYPE_DOMAIN (TREE_TYPE (local->field))
4795 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (local->field))))
4797 fieldsize = array_size_for_constructor (local->val);
4798 /* Given a non-empty initialization, this field had
4799 better be last. */
4800 gcc_assert (!fieldsize || !TREE_CHAIN (local->field));
4802 else if (DECL_SIZE_UNIT (local->field))
4804 /* ??? This can't be right. If the decl size overflows
4805 a host integer we will silently emit no data. */
4806 if (host_integerp (DECL_SIZE_UNIT (local->field), 1))
4807 fieldsize = tree_low_cst (DECL_SIZE_UNIT (local->field), 1);
4810 else
4811 fieldsize = int_size_in_bytes (TREE_TYPE (local->type));
4813 /* Output the element's initial value. */
4814 if (local->val == NULL_TREE)
4815 assemble_zeros (fieldsize);
4816 else
4817 output_constant (local->val, fieldsize, align2);
4819 /* Count its size. */
4820 local->total_bytes += fieldsize;
4823 /* Helper for output_constructor. From the current LOCAL and OUTER states,
4824 output an element that is a true bitfield or part of an outer one. */
4826 static void
4827 output_constructor_bitfield (oc_local_state *local, oc_outer_state *outer)
4829 /* Bit size of this element. */
4830 HOST_WIDE_INT ebitsize
4831 = (local->field
4832 ? tree_low_cst (DECL_SIZE (local->field), 1)
4833 : tree_low_cst (TYPE_SIZE (TREE_TYPE (local->type)), 1));
4835 /* Relative index of this element if this is an array component. */
4836 HOST_WIDE_INT relative_index
4837 = (!local->field
4838 ? (local->index
4839 ? (tree_low_cst (local->index, 0)
4840 - tree_low_cst (local->min_index, 0))
4841 : local->last_relative_index + 1)
4842 : 0);
4844 /* Bit position of this element from the start of the containing
4845 constructor. */
4846 HOST_WIDE_INT constructor_relative_ebitpos
4847 = (local->field
4848 ? int_bit_position (local->field)
4849 : ebitsize * relative_index);
4851 /* Bit position of this element from the start of a possibly ongoing
4852 outer byte buffer. */
4853 HOST_WIDE_INT byte_relative_ebitpos
4854 = ((outer ? outer->bit_offset : 0) + constructor_relative_ebitpos);
4856 /* From the start of a possibly ongoing outer byte buffer, offsets to
4857 the first bit of this element and to the first bit past the end of
4858 this element. */
4859 HOST_WIDE_INT next_offset = byte_relative_ebitpos;
4860 HOST_WIDE_INT end_offset = byte_relative_ebitpos + ebitsize;
4862 local->last_relative_index = relative_index;
4864 if (local->val == NULL_TREE)
4865 local->val = integer_zero_node;
4867 while (TREE_CODE (local->val) == VIEW_CONVERT_EXPR
4868 || TREE_CODE (local->val) == NON_LVALUE_EXPR)
4869 local->val = TREE_OPERAND (local->val, 0);
4871 if (TREE_CODE (local->val) != INTEGER_CST
4872 && TREE_CODE (local->val) != CONSTRUCTOR)
4874 error ("invalid initial value for member %qE", DECL_NAME (local->field));
4875 return;
4878 /* If this field does not start in this (or, next) byte,
4879 skip some bytes. */
4880 if (next_offset / BITS_PER_UNIT != local->total_bytes)
4882 /* Output remnant of any bit field in previous bytes. */
4883 if (local->byte_buffer_in_use)
4885 assemble_integer (GEN_INT (local->byte), 1, BITS_PER_UNIT, 1);
4886 local->total_bytes++;
4887 local->byte_buffer_in_use = false;
4890 /* If still not at proper byte, advance to there. */
4891 if (next_offset / BITS_PER_UNIT != local->total_bytes)
4893 gcc_assert (next_offset / BITS_PER_UNIT >= local->total_bytes);
4894 assemble_zeros (next_offset / BITS_PER_UNIT - local->total_bytes);
4895 local->total_bytes = next_offset / BITS_PER_UNIT;
4899 /* Set up the buffer if necessary. */
4900 if (!local->byte_buffer_in_use)
4902 local->byte = 0;
4903 if (ebitsize > 0)
4904 local->byte_buffer_in_use = true;
4907 /* If this is nested constructor, recurse passing the bit offset and the
4908 pending data, then retrieve the new pending data afterwards. */
4909 if (TREE_CODE (local->val) == CONSTRUCTOR)
4911 oc_outer_state output_state;
4913 output_state.bit_offset = next_offset % BITS_PER_UNIT;
4914 output_state.byte = local->byte;
4915 local->total_bytes
4916 += output_constructor (local->val, 0, 0, &output_state);
4917 local->byte = output_state.byte;
4918 return;
4921 /* Otherwise, we must split the element into pieces that fall within
4922 separate bytes, and combine each byte with previous or following
4923 bit-fields. */
4924 while (next_offset < end_offset)
4926 int this_time;
4927 int shift;
4928 HOST_WIDE_INT value;
4929 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
4930 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
4932 /* Advance from byte to byte
4933 within this element when necessary. */
4934 while (next_byte != local->total_bytes)
4936 assemble_integer (GEN_INT (local->byte), 1, BITS_PER_UNIT, 1);
4937 local->total_bytes++;
4938 local->byte = 0;
4941 /* Number of bits we can process at once
4942 (all part of the same byte). */
4943 this_time = MIN (end_offset - next_offset,
4944 BITS_PER_UNIT - next_bit);
4945 if (BYTES_BIG_ENDIAN)
4947 /* On big-endian machine, take the most significant bits
4948 first (of the bits that are significant)
4949 and put them into bytes from the most significant end. */
4950 shift = end_offset - next_offset - this_time;
4952 /* Don't try to take a bunch of bits that cross
4953 the word boundary in the INTEGER_CST. We can
4954 only select bits from the LOW or HIGH part
4955 not from both. */
4956 if (shift < HOST_BITS_PER_WIDE_INT
4957 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4959 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT;
4960 shift = HOST_BITS_PER_WIDE_INT;
4963 /* Now get the bits from the appropriate constant word. */
4964 if (shift < HOST_BITS_PER_WIDE_INT)
4965 value = TREE_INT_CST_LOW (local->val);
4966 else
4968 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4969 value = TREE_INT_CST_HIGH (local->val);
4970 shift -= HOST_BITS_PER_WIDE_INT;
4973 /* Get the result. This works only when:
4974 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4975 local->byte |= (((value >> shift)
4976 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4977 << (BITS_PER_UNIT - this_time - next_bit));
4979 else
4981 /* On little-endian machines,
4982 take first the least significant bits of the value
4983 and pack them starting at the least significant
4984 bits of the bytes. */
4985 shift = next_offset - byte_relative_ebitpos;
4987 /* Don't try to take a bunch of bits that cross
4988 the word boundary in the INTEGER_CST. We can
4989 only select bits from the LOW or HIGH part
4990 not from both. */
4991 if (shift < HOST_BITS_PER_WIDE_INT
4992 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4993 this_time = (HOST_BITS_PER_WIDE_INT - shift);
4995 /* Now get the bits from the appropriate constant word. */
4996 if (shift < HOST_BITS_PER_WIDE_INT)
4997 value = TREE_INT_CST_LOW (local->val);
4998 else
5000 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
5001 value = TREE_INT_CST_HIGH (local->val);
5002 shift -= HOST_BITS_PER_WIDE_INT;
5005 /* Get the result. This works only when:
5006 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
5007 local->byte |= (((value >> shift)
5008 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
5009 << next_bit);
5012 next_offset += this_time;
5013 local->byte_buffer_in_use = true;
5017 /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants).
5018 Generate at least SIZE bytes, padding if necessary. OUTER designates the
5019 caller output state of relevance in recursive invocations. */
5021 static unsigned HOST_WIDE_INT
5022 output_constructor (tree exp, unsigned HOST_WIDE_INT size,
5023 unsigned int align, oc_outer_state * outer)
5025 unsigned HOST_WIDE_INT cnt;
5026 constructor_elt *ce;
5028 oc_local_state local;
5030 /* Setup our local state to communicate with helpers. */
5031 local.exp = exp;
5032 local.size = size;
5033 local.align = align;
5035 local.total_bytes = 0;
5036 local.byte_buffer_in_use = outer != NULL;
5037 local.byte = outer ? outer->byte : 0;
5039 local.type = TREE_TYPE (exp);
5041 local.last_relative_index = -1;
5043 local.min_index = NULL_TREE;
5044 if (TREE_CODE (local.type) == ARRAY_TYPE
5045 && TYPE_DOMAIN (local.type) != NULL_TREE)
5046 local.min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (local.type));
5048 gcc_assert (HOST_BITS_PER_WIDE_INT >= BITS_PER_UNIT);
5050 /* As CE goes through the elements of the constant, FIELD goes through the
5051 structure fields if the constant is a structure. If the constant is a
5052 union, we override this by getting the field from the TREE_LIST element.
5053 But the constant could also be an array. Then FIELD is zero.
5055 There is always a maximum of one element in the chain LINK for unions
5056 (even if the initializer in a source program incorrectly contains
5057 more one). */
5059 local.field = NULL_TREE;
5060 if (TREE_CODE (local.type) == RECORD_TYPE)
5061 local.field = TYPE_FIELDS (local.type);
5063 for (cnt = 0;
5064 VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (exp), cnt, ce);
5065 cnt++, local.field = local.field ? TREE_CHAIN (local.field) : 0)
5067 local.val = ce->value;
5068 local.index = NULL_TREE;
5070 /* The element in a union constructor specifies the proper field
5071 or index. */
5072 if ((TREE_CODE (local.type) == RECORD_TYPE
5073 || TREE_CODE (local.type) == UNION_TYPE
5074 || TREE_CODE (local.type) == QUAL_UNION_TYPE)
5075 && ce->index != NULL_TREE)
5076 local.field = ce->index;
5078 else if (TREE_CODE (local.type) == ARRAY_TYPE)
5079 local.index = ce->index;
5081 #ifdef ASM_COMMENT_START
5082 if (local.field && flag_verbose_asm)
5083 fprintf (asm_out_file, "%s %s:\n",
5084 ASM_COMMENT_START,
5085 DECL_NAME (local.field)
5086 ? IDENTIFIER_POINTER (DECL_NAME (local.field))
5087 : "<anonymous>");
5088 #endif
5090 /* Eliminate the marker that makes a cast not be an lvalue. */
5091 if (local.val != NULL_TREE)
5092 STRIP_NOPS (local.val);
5094 /* Output the current element, using the appropriate helper ... */
5096 /* For an array slice not part of an outer bitfield. */
5097 if (!outer
5098 && local.index != NULL_TREE
5099 && TREE_CODE (local.index) == RANGE_EXPR)
5100 output_constructor_array_range (&local);
5102 /* For a field that is neither a true bitfield nor part of an outer one,
5103 known to be at least byte aligned and multiple-of-bytes long. */
5104 else if (!outer
5105 && (local.field == NULL_TREE
5106 || !CONSTRUCTOR_BITFIELD_P (local.field)))
5107 output_constructor_regular_field (&local);
5109 /* For a true bitfield or part of an outer one. */
5110 else
5111 output_constructor_bitfield (&local, outer);
5114 /* If we are not at toplevel, save the pending data for our caller.
5115 Otherwise output the pending data and padding zeros as needed. */
5116 if (outer)
5117 outer->byte = local.byte;
5118 else
5120 if (local.byte_buffer_in_use)
5122 assemble_integer (GEN_INT (local.byte), 1, BITS_PER_UNIT, 1);
5123 local.total_bytes++;
5126 if ((unsigned HOST_WIDE_INT)local.total_bytes < local.size)
5128 assemble_zeros (local.size - local.total_bytes);
5129 local.total_bytes = local.size;
5133 return local.total_bytes;
5136 /* Mark DECL as weak. */
5138 static void
5139 mark_weak (tree decl)
5141 DECL_WEAK (decl) = 1;
5143 if (DECL_RTL_SET_P (decl)
5144 && MEM_P (DECL_RTL (decl))
5145 && XEXP (DECL_RTL (decl), 0)
5146 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF)
5147 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1;
5150 /* Merge weak status between NEWDECL and OLDDECL. */
5152 void
5153 merge_weak (tree newdecl, tree olddecl)
5155 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl))
5157 if (DECL_WEAK (newdecl) && SUPPORTS_WEAK)
5159 tree *pwd;
5160 /* We put the NEWDECL on the weak_decls list at some point
5161 and OLDDECL as well. Keep just OLDDECL on the list. */
5162 for (pwd = &weak_decls; *pwd; pwd = &TREE_CHAIN (*pwd))
5163 if (TREE_VALUE (*pwd) == newdecl)
5165 *pwd = TREE_CHAIN (*pwd);
5166 break;
5169 return;
5172 if (DECL_WEAK (newdecl))
5174 tree wd;
5176 /* NEWDECL is weak, but OLDDECL is not. */
5178 /* If we already output the OLDDECL, we're in trouble; we can't
5179 go back and make it weak. This error cannot be caught in
5180 declare_weak because the NEWDECL and OLDDECL was not yet
5181 been merged; therefore, TREE_ASM_WRITTEN was not set. */
5182 if (TREE_ASM_WRITTEN (olddecl))
5183 error ("weak declaration of %q+D must precede definition",
5184 newdecl);
5186 /* If we've already generated rtl referencing OLDDECL, we may
5187 have done so in a way that will not function properly with
5188 a weak symbol. */
5189 else if (TREE_USED (olddecl)
5190 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl)))
5191 warning (0, "weak declaration of %q+D after first use results "
5192 "in unspecified behavior", newdecl);
5194 if (SUPPORTS_WEAK)
5196 /* We put the NEWDECL on the weak_decls list at some point.
5197 Replace it with the OLDDECL. */
5198 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd))
5199 if (TREE_VALUE (wd) == newdecl)
5201 TREE_VALUE (wd) = olddecl;
5202 break;
5204 /* We may not find the entry on the list. If NEWDECL is a
5205 weak alias, then we will have already called
5206 globalize_decl to remove the entry; in that case, we do
5207 not need to do anything. */
5210 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */
5211 mark_weak (olddecl);
5213 else
5214 /* OLDDECL was weak, but NEWDECL was not explicitly marked as
5215 weak. Just update NEWDECL to indicate that it's weak too. */
5216 mark_weak (newdecl);
5219 /* Declare DECL to be a weak symbol. */
5221 void
5222 declare_weak (tree decl)
5224 if (! TREE_PUBLIC (decl))
5225 error ("weak declaration of %q+D must be public", decl);
5226 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl))
5227 error ("weak declaration of %q+D must precede definition", decl);
5228 else if (!SUPPORTS_WEAK)
5229 warning (0, "weak declaration of %q+D not supported", decl);
5231 mark_weak (decl);
5234 static void
5235 weak_finish_1 (tree decl)
5237 #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL)
5238 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5239 #endif
5241 if (! TREE_USED (decl))
5242 return;
5244 #ifdef ASM_WEAKEN_DECL
5245 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL);
5246 #else
5247 #ifdef ASM_WEAKEN_LABEL
5248 ASM_WEAKEN_LABEL (asm_out_file, name);
5249 #else
5250 #ifdef ASM_OUTPUT_WEAK_ALIAS
5252 static bool warn_once = 0;
5253 if (! warn_once)
5255 warning (0, "only weak aliases are supported in this configuration");
5256 warn_once = 1;
5258 return;
5260 #endif
5261 #endif
5262 #endif
5265 /* This TREE_LIST contains weakref targets. */
5267 static GTY(()) tree weakref_targets;
5269 /* Forward declaration. */
5270 static tree find_decl_and_mark_needed (tree decl, tree target);
5272 /* Emit any pending weak declarations. */
5274 void
5275 weak_finish (void)
5277 tree t;
5279 for (t = weakref_targets; t; t = TREE_CHAIN (t))
5281 tree alias_decl = TREE_PURPOSE (t);
5282 tree target = ultimate_transparent_alias_target (&TREE_VALUE (t));
5284 if (! TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (alias_decl)))
5285 /* Remove alias_decl from the weak list, but leave entries for
5286 the target alone. */
5287 target = NULL_TREE;
5288 #ifndef ASM_OUTPUT_WEAKREF
5289 else if (! TREE_SYMBOL_REFERENCED (target))
5291 /* Use ASM_WEAKEN_LABEL only if ASM_WEAKEN_DECL is not
5292 defined, otherwise we and weak_finish_1 would use
5293 different macros. */
5294 # if defined ASM_WEAKEN_LABEL && ! defined ASM_WEAKEN_DECL
5295 ASM_WEAKEN_LABEL (asm_out_file, IDENTIFIER_POINTER (target));
5296 # else
5297 tree decl = find_decl_and_mark_needed (alias_decl, target);
5299 if (! decl)
5301 decl = build_decl (DECL_SOURCE_LOCATION (alias_decl),
5302 TREE_CODE (alias_decl), target,
5303 TREE_TYPE (alias_decl));
5305 DECL_EXTERNAL (decl) = 1;
5306 TREE_PUBLIC (decl) = 1;
5307 DECL_ARTIFICIAL (decl) = 1;
5308 TREE_NOTHROW (decl) = TREE_NOTHROW (alias_decl);
5309 TREE_USED (decl) = 1;
5312 weak_finish_1 (decl);
5313 # endif
5315 #endif
5318 tree *p;
5319 tree t2;
5321 /* Remove the alias and the target from the pending weak list
5322 so that we do not emit any .weak directives for the former,
5323 nor multiple .weak directives for the latter. */
5324 for (p = &weak_decls; (t2 = *p) ; )
5326 if (TREE_VALUE (t2) == alias_decl
5327 || target == DECL_ASSEMBLER_NAME (TREE_VALUE (t2)))
5328 *p = TREE_CHAIN (t2);
5329 else
5330 p = &TREE_CHAIN (t2);
5333 /* Remove other weakrefs to the same target, to speed things up. */
5334 for (p = &TREE_CHAIN (t); (t2 = *p) ; )
5336 if (target == ultimate_transparent_alias_target (&TREE_VALUE (t2)))
5337 *p = TREE_CHAIN (t2);
5338 else
5339 p = &TREE_CHAIN (t2);
5344 for (t = weak_decls; t; t = TREE_CHAIN (t))
5346 tree decl = TREE_VALUE (t);
5348 weak_finish_1 (decl);
5352 /* Emit the assembly bits to indicate that DECL is globally visible. */
5354 static void
5355 globalize_decl (tree decl)
5358 #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL)
5359 if (DECL_WEAK (decl))
5361 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
5362 tree *p, t;
5364 #ifdef ASM_WEAKEN_DECL
5365 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
5366 #else
5367 ASM_WEAKEN_LABEL (asm_out_file, name);
5368 #endif
5370 /* Remove this function from the pending weak list so that
5371 we do not emit multiple .weak directives for it. */
5372 for (p = &weak_decls; (t = *p) ; )
5374 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5375 *p = TREE_CHAIN (t);
5376 else
5377 p = &TREE_CHAIN (t);
5380 /* Remove weakrefs to the same target from the pending weakref
5381 list, for the same reason. */
5382 for (p = &weakref_targets; (t = *p) ; )
5384 if (DECL_ASSEMBLER_NAME (decl)
5385 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5386 *p = TREE_CHAIN (t);
5387 else
5388 p = &TREE_CHAIN (t);
5391 return;
5393 #endif
5395 targetm.asm_out.globalize_decl_name (asm_out_file, decl);
5398 VEC(alias_pair,gc) *alias_pairs;
5400 /* Given an assembly name, find the decl it is associated with. At the
5401 same time, mark it needed for cgraph. */
5403 static tree
5404 find_decl_and_mark_needed (tree decl, tree target)
5406 struct cgraph_node *fnode = NULL;
5407 struct varpool_node *vnode = NULL;
5409 if (TREE_CODE (decl) == FUNCTION_DECL)
5411 fnode = cgraph_node_for_asm (target);
5412 if (fnode == NULL)
5413 vnode = varpool_node_for_asm (target);
5415 else
5417 vnode = varpool_node_for_asm (target);
5418 if (vnode == NULL)
5419 fnode = cgraph_node_for_asm (target);
5422 if (fnode)
5424 cgraph_mark_needed_node (fnode);
5425 return fnode->decl;
5427 else if (vnode)
5429 varpool_mark_needed_node (vnode);
5430 return vnode->decl;
5432 else
5433 return NULL_TREE;
5436 /* Output the assembler code for a define (equate) using ASM_OUTPUT_DEF
5437 or ASM_OUTPUT_DEF_FROM_DECLS. The function defines the symbol whose
5438 tree node is DECL to have the value of the tree node TARGET. */
5440 static void
5441 do_assemble_alias (tree decl, tree target)
5443 if (TREE_ASM_WRITTEN (decl))
5444 return;
5446 TREE_ASM_WRITTEN (decl) = 1;
5447 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;
5449 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5451 ultimate_transparent_alias_target (&target);
5453 if (!targetm.have_tls
5454 && TREE_CODE (decl) == VAR_DECL
5455 && DECL_THREAD_LOCAL_P (decl))
5457 decl = emutls_decl (decl);
5458 target = get_emutls_object_name (target);
5461 if (!TREE_SYMBOL_REFERENCED (target))
5462 weakref_targets = tree_cons (decl, target, weakref_targets);
5464 #ifdef ASM_OUTPUT_WEAKREF
5465 ASM_OUTPUT_WEAKREF (asm_out_file, decl,
5466 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5467 IDENTIFIER_POINTER (target));
5468 #else
5469 if (!SUPPORTS_WEAK)
5471 error_at (DECL_SOURCE_LOCATION (decl),
5472 "weakref is not supported in this configuration");
5473 return;
5475 #endif
5476 return;
5479 if (!targetm.have_tls
5480 && TREE_CODE (decl) == VAR_DECL
5481 && DECL_THREAD_LOCAL_P (decl))
5483 decl = emutls_decl (decl);
5484 target = get_emutls_object_name (target);
5487 #ifdef ASM_OUTPUT_DEF
5488 /* Make name accessible from other files, if appropriate. */
5490 if (TREE_PUBLIC (decl))
5492 globalize_decl (decl);
5493 maybe_assemble_visibility (decl);
5496 # ifdef ASM_OUTPUT_DEF_FROM_DECLS
5497 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target);
5498 # else
5499 ASM_OUTPUT_DEF (asm_out_file,
5500 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5501 IDENTIFIER_POINTER (target));
5502 # endif
5503 #elif defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
5505 const char *name;
5506 tree *p, t;
5508 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5509 # ifdef ASM_WEAKEN_DECL
5510 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target));
5511 # else
5512 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
5513 # endif
5514 /* Remove this function from the pending weak list so that
5515 we do not emit multiple .weak directives for it. */
5516 for (p = &weak_decls; (t = *p) ; )
5517 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5518 *p = TREE_CHAIN (t);
5519 else
5520 p = &TREE_CHAIN (t);
5522 /* Remove weakrefs to the same target from the pending weakref
5523 list, for the same reason. */
5524 for (p = &weakref_targets; (t = *p) ; )
5526 if (DECL_ASSEMBLER_NAME (decl)
5527 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5528 *p = TREE_CHAIN (t);
5529 else
5530 p = &TREE_CHAIN (t);
5533 #endif
5537 /* Remove the alias pairing for functions that are no longer in the call
5538 graph. */
5540 void
5541 remove_unreachable_alias_pairs (void)
5543 unsigned i;
5544 alias_pair *p;
5546 if (alias_pairs == NULL)
5547 return;
5549 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); )
5551 if (!DECL_EXTERNAL (p->decl))
5553 struct cgraph_node *fnode = NULL;
5554 struct varpool_node *vnode = NULL;
5555 fnode = cgraph_node_for_asm (p->target);
5556 vnode = (fnode == NULL) ? varpool_node_for_asm (p->target) : NULL;
5557 if (fnode == NULL && vnode == NULL)
5559 VEC_unordered_remove (alias_pair, alias_pairs, i);
5560 continue;
5564 i++;
5569 /* First pass of completing pending aliases. Make sure that cgraph knows
5570 which symbols will be required. */
5572 void
5573 finish_aliases_1 (void)
5575 unsigned i;
5576 alias_pair *p;
5578 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
5580 tree target_decl;
5582 target_decl = find_decl_and_mark_needed (p->decl, p->target);
5583 if (target_decl == NULL)
5585 if (! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5586 error ("%q+D aliased to undefined symbol %qE",
5587 p->decl, p->target);
5589 else if (DECL_EXTERNAL (target_decl)
5590 /* We use local aliases for C++ thunks to force the tailcall
5591 to bind locally. Of course this is a hack - to keep it
5592 working do the following (which is not strictly correct). */
5593 && (! TREE_CODE (target_decl) == FUNCTION_DECL
5594 || ! DECL_VIRTUAL_P (target_decl))
5595 && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5596 error ("%q+D aliased to external symbol %qE",
5597 p->decl, p->target);
5601 /* Second pass of completing pending aliases. Emit the actual assembly.
5602 This happens at the end of compilation and thus it is assured that the
5603 target symbol has been emitted. */
5605 void
5606 finish_aliases_2 (void)
5608 unsigned i;
5609 alias_pair *p;
5611 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
5612 do_assemble_alias (p->decl, p->target);
5614 VEC_truncate (alias_pair, alias_pairs, 0);
5617 /* Emit an assembler directive to make the symbol for DECL an alias to
5618 the symbol for TARGET. */
5620 void
5621 assemble_alias (tree decl, tree target)
5623 tree target_decl;
5624 bool is_weakref = false;
5626 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5628 tree alias = DECL_ASSEMBLER_NAME (decl);
5630 is_weakref = true;
5632 ultimate_transparent_alias_target (&target);
5634 if (alias == target)
5635 error ("weakref %q+D ultimately targets itself", decl);
5636 else
5638 #ifndef ASM_OUTPUT_WEAKREF
5639 IDENTIFIER_TRANSPARENT_ALIAS (alias) = 1;
5640 TREE_CHAIN (alias) = target;
5641 #endif
5643 if (TREE_PUBLIC (decl))
5644 error ("weakref %q+D must have static linkage", decl);
5646 else
5648 #if !defined (ASM_OUTPUT_DEF)
5649 # if !defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL)
5650 error_at (DECL_SOURCE_LOCATION (decl),
5651 "alias definitions not supported in this configuration");
5652 return;
5653 # else
5654 if (!DECL_WEAK (decl))
5656 error_at (DECL_SOURCE_LOCATION (decl),
5657 "only weak aliases are supported in this configuration");
5658 return;
5660 # endif
5661 #endif
5664 /* We must force creation of DECL_RTL for debug info generation, even though
5665 we don't use it here. */
5666 make_decl_rtl (decl);
5667 TREE_USED (decl) = 1;
5669 /* A quirk of the initial implementation of aliases required that the user
5670 add "extern" to all of them. Which is silly, but now historical. Do
5671 note that the symbol is in fact locally defined. */
5672 if (! is_weakref)
5673 DECL_EXTERNAL (decl) = 0;
5675 /* Allow aliases to aliases. */
5676 if (TREE_CODE (decl) == FUNCTION_DECL)
5677 cgraph_node (decl)->alias = true;
5678 else
5679 varpool_node (decl)->alias = true;
5681 /* If the target has already been emitted, we don't have to queue the
5682 alias. This saves a tad of memory. */
5683 if (cgraph_global_info_ready)
5684 target_decl = find_decl_and_mark_needed (decl, target);
5685 else
5686 target_decl= NULL;
5687 if (target_decl && TREE_ASM_WRITTEN (target_decl))
5688 do_assemble_alias (decl, target);
5689 else
5691 alias_pair *p = VEC_safe_push (alias_pair, gc, alias_pairs, NULL);
5692 p->decl = decl;
5693 p->target = target;
5697 /* Emit an assembler directive to set symbol for DECL visibility to
5698 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */
5700 void
5701 default_assemble_visibility (tree decl, int vis)
5703 static const char * const visibility_types[] = {
5704 NULL, "protected", "hidden", "internal"
5707 const char *name, *type;
5709 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5710 type = visibility_types[vis];
5712 #ifdef HAVE_GAS_HIDDEN
5713 fprintf (asm_out_file, "\t.%s\t", type);
5714 assemble_name (asm_out_file, name);
5715 fprintf (asm_out_file, "\n");
5716 #else
5717 warning (OPT_Wattributes, "visibility attribute not supported "
5718 "in this configuration; ignored");
5719 #endif
5722 /* A helper function to call assemble_visibility when needed for a decl. */
5725 maybe_assemble_visibility (tree decl)
5727 enum symbol_visibility vis = DECL_VISIBILITY (decl);
5729 if (vis != VISIBILITY_DEFAULT)
5731 targetm.asm_out.visibility (decl, vis);
5732 return 1;
5734 else
5735 return 0;
5738 /* Returns 1 if the target configuration supports defining public symbols
5739 so that one of them will be chosen at link time instead of generating a
5740 multiply-defined symbol error, whether through the use of weak symbols or
5741 a target-specific mechanism for having duplicates discarded. */
5744 supports_one_only (void)
5746 if (SUPPORTS_ONE_ONLY)
5747 return 1;
5748 return SUPPORTS_WEAK;
5751 /* Set up DECL as a public symbol that can be defined in multiple
5752 translation units without generating a linker error. */
5754 void
5755 make_decl_one_only (tree decl, tree comdat_group)
5757 gcc_assert (TREE_CODE (decl) == VAR_DECL
5758 || TREE_CODE (decl) == FUNCTION_DECL);
5760 TREE_PUBLIC (decl) = 1;
5762 if (SUPPORTS_ONE_ONLY)
5764 #ifdef MAKE_DECL_ONE_ONLY
5765 MAKE_DECL_ONE_ONLY (decl);
5766 #endif
5767 DECL_COMDAT_GROUP (decl) = comdat_group;
5769 else if (TREE_CODE (decl) == VAR_DECL
5770 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
5771 DECL_COMMON (decl) = 1;
5772 else
5774 gcc_assert (SUPPORTS_WEAK);
5775 DECL_WEAK (decl) = 1;
5779 void
5780 init_varasm_once (void)
5782 section_htab = htab_create_ggc (31, section_entry_hash,
5783 section_entry_eq, NULL);
5784 object_block_htab = htab_create_ggc (31, object_block_entry_hash,
5785 object_block_entry_eq, NULL);
5786 const_desc_htab = htab_create_ggc (1009, const_desc_hash,
5787 const_desc_eq, NULL);
5789 const_alias_set = new_alias_set ();
5790 shared_constant_pool = create_constant_pool ();
5792 #ifdef TEXT_SECTION_ASM_OP
5793 text_section = get_unnamed_section (SECTION_CODE, output_section_asm_op,
5794 TEXT_SECTION_ASM_OP);
5795 #endif
5797 #ifdef DATA_SECTION_ASM_OP
5798 data_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5799 DATA_SECTION_ASM_OP);
5800 #endif
5802 #ifdef SDATA_SECTION_ASM_OP
5803 sdata_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5804 SDATA_SECTION_ASM_OP);
5805 #endif
5807 #ifdef READONLY_DATA_SECTION_ASM_OP
5808 readonly_data_section = get_unnamed_section (0, output_section_asm_op,
5809 READONLY_DATA_SECTION_ASM_OP);
5810 #endif
5812 #ifdef CTORS_SECTION_ASM_OP
5813 ctors_section = get_unnamed_section (0, output_section_asm_op,
5814 CTORS_SECTION_ASM_OP);
5815 #endif
5817 #ifdef DTORS_SECTION_ASM_OP
5818 dtors_section = get_unnamed_section (0, output_section_asm_op,
5819 DTORS_SECTION_ASM_OP);
5820 #endif
5822 #ifdef BSS_SECTION_ASM_OP
5823 bss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5824 output_section_asm_op,
5825 BSS_SECTION_ASM_OP);
5826 #endif
5828 #ifdef SBSS_SECTION_ASM_OP
5829 sbss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5830 output_section_asm_op,
5831 SBSS_SECTION_ASM_OP);
5832 #endif
5834 tls_comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5835 | SECTION_COMMON, emit_tls_common);
5836 lcomm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5837 | SECTION_COMMON, emit_local);
5838 comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5839 | SECTION_COMMON, emit_common);
5841 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
5842 bss_noswitch_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS,
5843 emit_bss);
5844 #endif
5846 targetm.asm_out.init_sections ();
5848 if (readonly_data_section == NULL)
5849 readonly_data_section = text_section;
5852 enum tls_model
5853 decl_default_tls_model (const_tree decl)
5855 enum tls_model kind;
5856 bool is_local;
5858 is_local = targetm.binds_local_p (decl);
5859 if (!flag_shlib)
5861 if (is_local)
5862 kind = TLS_MODEL_LOCAL_EXEC;
5863 else
5864 kind = TLS_MODEL_INITIAL_EXEC;
5867 /* Local dynamic is inefficient when we're not combining the
5868 parts of the address. */
5869 else if (optimize && is_local)
5870 kind = TLS_MODEL_LOCAL_DYNAMIC;
5871 else
5872 kind = TLS_MODEL_GLOBAL_DYNAMIC;
5873 if (kind < flag_tls_default)
5874 kind = flag_tls_default;
5876 return kind;
5879 /* Select a set of attributes for section NAME based on the properties
5880 of DECL and whether or not RELOC indicates that DECL's initializer
5881 might contain runtime relocations.
5883 We make the section read-only and executable for a function decl,
5884 read-only for a const data decl, and writable for a non-const data decl. */
5886 unsigned int
5887 default_section_type_flags (tree decl, const char *name, int reloc)
5889 unsigned int flags;
5891 if (decl && TREE_CODE (decl) == FUNCTION_DECL)
5892 flags = SECTION_CODE;
5893 else if (decl && decl_readonly_section (decl, reloc))
5894 flags = 0;
5895 else if (current_function_decl
5896 && cfun
5897 && crtl->subsections.unlikely_text_section_name
5898 && strcmp (name, crtl->subsections.unlikely_text_section_name) == 0)
5899 flags = SECTION_CODE;
5900 else if (!decl
5901 && (!current_function_decl || !cfun)
5902 && strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
5903 flags = SECTION_CODE;
5904 else
5905 flags = SECTION_WRITE;
5907 if (decl && DECL_ONE_ONLY (decl))
5908 flags |= SECTION_LINKONCE;
5910 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
5911 flags |= SECTION_TLS | SECTION_WRITE;
5913 if (strcmp (name, ".bss") == 0
5914 || strncmp (name, ".bss.", 5) == 0
5915 || strncmp (name, ".gnu.linkonce.b.", 16) == 0
5916 || strcmp (name, ".sbss") == 0
5917 || strncmp (name, ".sbss.", 6) == 0
5918 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0)
5919 flags |= SECTION_BSS;
5921 if (strcmp (name, ".tdata") == 0
5922 || strncmp (name, ".tdata.", 7) == 0
5923 || strncmp (name, ".gnu.linkonce.td.", 17) == 0)
5924 flags |= SECTION_TLS;
5926 if (strcmp (name, ".tbss") == 0
5927 || strncmp (name, ".tbss.", 6) == 0
5928 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
5929 flags |= SECTION_TLS | SECTION_BSS;
5931 /* These three sections have special ELF types. They are neither
5932 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't
5933 want to print a section type (@progbits or @nobits). If someone
5934 is silly enough to emit code or TLS variables to one of these
5935 sections, then don't handle them specially. */
5936 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS))
5937 && (strcmp (name, ".init_array") == 0
5938 || strcmp (name, ".fini_array") == 0
5939 || strcmp (name, ".preinit_array") == 0))
5940 flags |= SECTION_NOTYPE;
5942 return flags;
5945 /* Return true if the target supports some form of global BSS,
5946 either through bss_noswitch_section, or by selecting a BSS
5947 section in TARGET_ASM_SELECT_SECTION. */
5949 bool
5950 have_global_bss_p (void)
5952 return bss_noswitch_section || targetm.have_switchable_bss_sections;
5955 /* Output assembly to switch to section NAME with attribute FLAGS.
5956 Four variants for common object file formats. */
5958 void
5959 default_no_named_section (const char *name ATTRIBUTE_UNUSED,
5960 unsigned int flags ATTRIBUTE_UNUSED,
5961 tree decl ATTRIBUTE_UNUSED)
5963 /* Some object formats don't support named sections at all. The
5964 front-end should already have flagged this as an error. */
5965 gcc_unreachable ();
5968 void
5969 default_elf_asm_named_section (const char *name, unsigned int flags,
5970 tree decl ATTRIBUTE_UNUSED)
5972 char flagchars[10], *f = flagchars;
5974 /* If we have already declared this section, we can use an
5975 abbreviated form to switch back to it -- unless this section is
5976 part of a COMDAT groups, in which case GAS requires the full
5977 declaration every time. */
5978 if (!(HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5979 && (flags & SECTION_DECLARED))
5981 fprintf (asm_out_file, "\t.section\t%s\n", name);
5982 return;
5985 if (!(flags & SECTION_DEBUG))
5986 *f++ = 'a';
5987 if (flags & SECTION_WRITE)
5988 *f++ = 'w';
5989 if (flags & SECTION_CODE)
5990 *f++ = 'x';
5991 if (flags & SECTION_SMALL)
5992 *f++ = 's';
5993 if (flags & SECTION_MERGE)
5994 *f++ = 'M';
5995 if (flags & SECTION_STRINGS)
5996 *f++ = 'S';
5997 if (flags & SECTION_TLS)
5998 *f++ = 'T';
5999 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
6000 *f++ = 'G';
6001 *f = '\0';
6003 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);
6005 if (!(flags & SECTION_NOTYPE))
6007 const char *type;
6008 const char *format;
6010 if (flags & SECTION_BSS)
6011 type = "nobits";
6012 else
6013 type = "progbits";
6015 format = ",@%s";
6016 #ifdef ASM_COMMENT_START
6017 /* On platforms that use "@" as the assembly comment character,
6018 use "%" instead. */
6019 if (strcmp (ASM_COMMENT_START, "@") == 0)
6020 format = ",%%%s";
6021 #endif
6022 fprintf (asm_out_file, format, type);
6024 if (flags & SECTION_ENTSIZE)
6025 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
6026 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
6028 if (TREE_CODE (decl) == IDENTIFIER_NODE)
6029 fprintf (asm_out_file, ",%s,comdat", IDENTIFIER_POINTER (decl));
6030 else
6031 fprintf (asm_out_file, ",%s,comdat",
6032 IDENTIFIER_POINTER (DECL_COMDAT_GROUP (decl)));
6036 putc ('\n', asm_out_file);
6039 void
6040 default_coff_asm_named_section (const char *name, unsigned int flags,
6041 tree decl ATTRIBUTE_UNUSED)
6043 char flagchars[8], *f = flagchars;
6045 if (flags & SECTION_WRITE)
6046 *f++ = 'w';
6047 if (flags & SECTION_CODE)
6048 *f++ = 'x';
6049 *f = '\0';
6051 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);
6054 void
6055 default_pe_asm_named_section (const char *name, unsigned int flags,
6056 tree decl)
6058 default_coff_asm_named_section (name, flags, decl);
6060 if (flags & SECTION_LINKONCE)
6062 /* Functions may have been compiled at various levels of
6063 optimization so we can't use `same_size' here.
6064 Instead, have the linker pick one. */
6065 fprintf (asm_out_file, "\t.linkonce %s\n",
6066 (flags & SECTION_CODE ? "discard" : "same_size"));
6070 /* The lame default section selector. */
6072 section *
6073 default_select_section (tree decl, int reloc,
6074 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
6076 if (DECL_P (decl))
6078 if (decl_readonly_section (decl, reloc))
6079 return readonly_data_section;
6081 else if (TREE_CODE (decl) == CONSTRUCTOR)
6083 if (! ((flag_pic && reloc)
6084 || !TREE_READONLY (decl)
6085 || TREE_SIDE_EFFECTS (decl)
6086 || !TREE_CONSTANT (decl)))
6087 return readonly_data_section;
6089 else if (TREE_CODE (decl) == STRING_CST)
6090 return readonly_data_section;
6091 else if (! (flag_pic && reloc))
6092 return readonly_data_section;
6094 return data_section;
6097 enum section_category
6098 categorize_decl_for_section (const_tree decl, int reloc)
6100 enum section_category ret;
6102 if (TREE_CODE (decl) == FUNCTION_DECL)
6103 return SECCAT_TEXT;
6104 else if (TREE_CODE (decl) == STRING_CST)
6106 if (flag_mudflap) /* or !flag_merge_constants */
6107 return SECCAT_RODATA;
6108 else
6109 return SECCAT_RODATA_MERGE_STR;
6111 else if (TREE_CODE (decl) == VAR_DECL)
6113 if (bss_initializer_p (decl))
6114 ret = SECCAT_BSS;
6115 else if (! TREE_READONLY (decl)
6116 || TREE_SIDE_EFFECTS (decl)
6117 || ! TREE_CONSTANT (DECL_INITIAL (decl)))
6119 /* Here the reloc_rw_mask is not testing whether the section should
6120 be read-only or not, but whether the dynamic link will have to
6121 do something. If so, we wish to segregate the data in order to
6122 minimize cache misses inside the dynamic linker. */
6123 if (reloc & targetm.asm_out.reloc_rw_mask ())
6124 ret = reloc == 1 ? SECCAT_DATA_REL_LOCAL : SECCAT_DATA_REL;
6125 else
6126 ret = SECCAT_DATA;
6128 else if (reloc & targetm.asm_out.reloc_rw_mask ())
6129 ret = reloc == 1 ? SECCAT_DATA_REL_RO_LOCAL : SECCAT_DATA_REL_RO;
6130 else if (reloc || flag_merge_constants < 2)
6131 /* C and C++ don't allow different variables to share the same
6132 location. -fmerge-all-constants allows even that (at the
6133 expense of not conforming). */
6134 ret = SECCAT_RODATA;
6135 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST)
6136 ret = SECCAT_RODATA_MERGE_STR_INIT;
6137 else
6138 ret = SECCAT_RODATA_MERGE_CONST;
6140 else if (TREE_CODE (decl) == CONSTRUCTOR)
6142 if ((reloc & targetm.asm_out.reloc_rw_mask ())
6143 || TREE_SIDE_EFFECTS (decl)
6144 || ! TREE_CONSTANT (decl))
6145 ret = SECCAT_DATA;
6146 else
6147 ret = SECCAT_RODATA;
6149 else
6150 ret = SECCAT_RODATA;
6152 /* There are no read-only thread-local sections. */
6153 if (TREE_CODE (decl) == VAR_DECL && DECL_TLS_MODEL (decl))
6155 if (DECL_TLS_MODEL (decl) == TLS_MODEL_EMULATED)
6157 if (DECL_EMUTLS_VAR_P (decl))
6159 if (targetm.emutls.var_section)
6160 ret = SECCAT_EMUTLS_VAR;
6162 else
6164 if (targetm.emutls.tmpl_prefix)
6165 ret = SECCAT_EMUTLS_TMPL;
6168 /* Note that this would be *just* SECCAT_BSS, except that there's
6169 no concept of a read-only thread-local-data section. */
6170 else if (ret == SECCAT_BSS
6171 || (flag_zero_initialized_in_bss
6172 && initializer_zerop (DECL_INITIAL (decl))))
6173 ret = SECCAT_TBSS;
6174 else
6175 ret = SECCAT_TDATA;
6178 /* If the target uses small data sections, select it. */
6179 else if (targetm.in_small_data_p (decl))
6181 if (ret == SECCAT_BSS)
6182 ret = SECCAT_SBSS;
6183 else if (targetm.have_srodata_section && ret == SECCAT_RODATA)
6184 ret = SECCAT_SRODATA;
6185 else
6186 ret = SECCAT_SDATA;
6189 return ret;
6192 bool
6193 decl_readonly_section (const_tree decl, int reloc)
6195 switch (categorize_decl_for_section (decl, reloc))
6197 case SECCAT_RODATA:
6198 case SECCAT_RODATA_MERGE_STR:
6199 case SECCAT_RODATA_MERGE_STR_INIT:
6200 case SECCAT_RODATA_MERGE_CONST:
6201 case SECCAT_SRODATA:
6202 return true;
6203 break;
6204 default:
6205 return false;
6206 break;
6210 /* Select a section based on the above categorization. */
6212 section *
6213 default_elf_select_section (tree decl, int reloc,
6214 unsigned HOST_WIDE_INT align)
6216 const char *sname;
6217 switch (categorize_decl_for_section (decl, reloc))
6219 case SECCAT_TEXT:
6220 /* We're not supposed to be called on FUNCTION_DECLs. */
6221 gcc_unreachable ();
6222 case SECCAT_RODATA:
6223 return readonly_data_section;
6224 case SECCAT_RODATA_MERGE_STR:
6225 return mergeable_string_section (decl, align, 0);
6226 case SECCAT_RODATA_MERGE_STR_INIT:
6227 return mergeable_string_section (DECL_INITIAL (decl), align, 0);
6228 case SECCAT_RODATA_MERGE_CONST:
6229 return mergeable_constant_section (DECL_MODE (decl), align, 0);
6230 case SECCAT_SRODATA:
6231 sname = ".sdata2";
6232 break;
6233 case SECCAT_DATA:
6234 return data_section;
6235 case SECCAT_DATA_REL:
6236 sname = ".data.rel";
6237 break;
6238 case SECCAT_DATA_REL_LOCAL:
6239 sname = ".data.rel.local";
6240 break;
6241 case SECCAT_DATA_REL_RO:
6242 sname = ".data.rel.ro";
6243 break;
6244 case SECCAT_DATA_REL_RO_LOCAL:
6245 sname = ".data.rel.ro.local";
6246 break;
6247 case SECCAT_SDATA:
6248 sname = ".sdata";
6249 break;
6250 case SECCAT_TDATA:
6251 sname = ".tdata";
6252 break;
6253 case SECCAT_BSS:
6254 if (bss_section)
6255 return bss_section;
6256 sname = ".bss";
6257 break;
6258 case SECCAT_SBSS:
6259 sname = ".sbss";
6260 break;
6261 case SECCAT_TBSS:
6262 sname = ".tbss";
6263 break;
6264 case SECCAT_EMUTLS_VAR:
6265 sname = targetm.emutls.var_section;
6266 break;
6267 case SECCAT_EMUTLS_TMPL:
6268 sname = targetm.emutls.tmpl_section;
6269 break;
6270 default:
6271 gcc_unreachable ();
6274 if (!DECL_P (decl))
6275 decl = NULL_TREE;
6276 return get_named_section (decl, sname, reloc);
6279 /* Construct a unique section name based on the decl name and the
6280 categorization performed above. */
6282 void
6283 default_unique_section (tree decl, int reloc)
6285 /* We only need to use .gnu.linkonce if we don't have COMDAT groups. */
6286 bool one_only = DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP;
6287 const char *prefix, *name, *linkonce;
6288 char *string;
6290 switch (categorize_decl_for_section (decl, reloc))
6292 case SECCAT_TEXT:
6293 prefix = one_only ? ".t" : ".text";
6294 break;
6295 case SECCAT_RODATA:
6296 case SECCAT_RODATA_MERGE_STR:
6297 case SECCAT_RODATA_MERGE_STR_INIT:
6298 case SECCAT_RODATA_MERGE_CONST:
6299 prefix = one_only ? ".r" : ".rodata";
6300 break;
6301 case SECCAT_SRODATA:
6302 prefix = one_only ? ".s2" : ".sdata2";
6303 break;
6304 case SECCAT_DATA:
6305 prefix = one_only ? ".d" : ".data";
6306 break;
6307 case SECCAT_DATA_REL:
6308 prefix = one_only ? ".d.rel" : ".data.rel";
6309 break;
6310 case SECCAT_DATA_REL_LOCAL:
6311 prefix = one_only ? ".d.rel.local" : ".data.rel.local";
6312 break;
6313 case SECCAT_DATA_REL_RO:
6314 prefix = one_only ? ".d.rel.ro" : ".data.rel.ro";
6315 break;
6316 case SECCAT_DATA_REL_RO_LOCAL:
6317 prefix = one_only ? ".d.rel.ro.local" : ".data.rel.ro.local";
6318 break;
6319 case SECCAT_SDATA:
6320 prefix = one_only ? ".s" : ".sdata";
6321 break;
6322 case SECCAT_BSS:
6323 prefix = one_only ? ".b" : ".bss";
6324 break;
6325 case SECCAT_SBSS:
6326 prefix = one_only ? ".sb" : ".sbss";
6327 break;
6328 case SECCAT_TDATA:
6329 prefix = one_only ? ".td" : ".tdata";
6330 break;
6331 case SECCAT_TBSS:
6332 prefix = one_only ? ".tb" : ".tbss";
6333 break;
6334 case SECCAT_EMUTLS_VAR:
6335 prefix = targetm.emutls.var_section;
6336 break;
6337 case SECCAT_EMUTLS_TMPL:
6338 prefix = targetm.emutls.tmpl_section;
6339 break;
6340 default:
6341 gcc_unreachable ();
6344 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
6345 name = targetm.strip_name_encoding (name);
6347 /* If we're using one_only, then there needs to be a .gnu.linkonce
6348 prefix to the section name. */
6349 linkonce = one_only ? ".gnu.linkonce" : "";
6351 string = ACONCAT ((linkonce, prefix, ".", name, NULL));
6353 DECL_SECTION_NAME (decl) = build_string (strlen (string), string);
6356 /* Like compute_reloc_for_constant, except for an RTX. The return value
6357 is a mask for which bit 1 indicates a global relocation, and bit 0
6358 indicates a local relocation. */
6360 static int
6361 compute_reloc_for_rtx_1 (rtx *xp, void *data)
6363 int *preloc = (int *) data;
6364 rtx x = *xp;
6366 switch (GET_CODE (x))
6368 case SYMBOL_REF:
6369 *preloc |= SYMBOL_REF_LOCAL_P (x) ? 1 : 2;
6370 break;
6371 case LABEL_REF:
6372 *preloc |= 1;
6373 break;
6374 default:
6375 break;
6378 return 0;
6381 static int
6382 compute_reloc_for_rtx (rtx x)
6384 int reloc;
6386 switch (GET_CODE (x))
6388 case CONST:
6389 case SYMBOL_REF:
6390 case LABEL_REF:
6391 reloc = 0;
6392 for_each_rtx (&x, compute_reloc_for_rtx_1, &reloc);
6393 return reloc;
6395 default:
6396 return 0;
6400 section *
6401 default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED,
6402 rtx x,
6403 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
6405 if (compute_reloc_for_rtx (x) & targetm.asm_out.reloc_rw_mask ())
6406 return data_section;
6407 else
6408 return readonly_data_section;
6411 section *
6412 default_elf_select_rtx_section (enum machine_mode mode, rtx x,
6413 unsigned HOST_WIDE_INT align)
6415 int reloc = compute_reloc_for_rtx (x);
6417 /* ??? Handle small data here somehow. */
6419 if (reloc & targetm.asm_out.reloc_rw_mask ())
6421 if (reloc == 1)
6422 return get_named_section (NULL, ".data.rel.ro.local", 1);
6423 else
6424 return get_named_section (NULL, ".data.rel.ro", 3);
6427 return mergeable_constant_section (mode, align, 0);
6430 /* Set the generally applicable flags on the SYMBOL_REF for EXP. */
6432 void
6433 default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
6435 rtx symbol;
6436 int flags;
6438 /* Careful not to prod global register variables. */
6439 if (!MEM_P (rtl))
6440 return;
6441 symbol = XEXP (rtl, 0);
6442 if (GET_CODE (symbol) != SYMBOL_REF)
6443 return;
6445 flags = SYMBOL_REF_FLAGS (symbol) & SYMBOL_FLAG_HAS_BLOCK_INFO;
6446 if (TREE_CODE (decl) == FUNCTION_DECL)
6447 flags |= SYMBOL_FLAG_FUNCTION;
6448 if (targetm.binds_local_p (decl))
6449 flags |= SYMBOL_FLAG_LOCAL;
6450 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl)
6451 && DECL_TLS_MODEL (decl) != TLS_MODEL_EMULATED)
6452 flags |= DECL_TLS_MODEL (decl) << SYMBOL_FLAG_TLS_SHIFT;
6453 else if (targetm.in_small_data_p (decl))
6454 flags |= SYMBOL_FLAG_SMALL;
6455 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without
6456 being PUBLIC, the thing *must* be defined in this translation unit.
6457 Prevent this buglet from being propagated into rtl code as well. */
6458 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
6459 flags |= SYMBOL_FLAG_EXTERNAL;
6461 SYMBOL_REF_FLAGS (symbol) = flags;
6464 /* By default, we do nothing for encode_section_info, so we need not
6465 do anything but discard the '*' marker. */
6467 const char *
6468 default_strip_name_encoding (const char *str)
6470 return str + (*str == '*');
6473 #ifdef ASM_OUTPUT_DEF
6474 /* The default implementation of TARGET_ASM_OUTPUT_ANCHOR. Define the
6475 anchor relative to ".", the current section position. */
6477 void
6478 default_asm_output_anchor (rtx symbol)
6480 char buffer[100];
6482 sprintf (buffer, "*. + " HOST_WIDE_INT_PRINT_DEC,
6483 SYMBOL_REF_BLOCK_OFFSET (symbol));
6484 ASM_OUTPUT_DEF (asm_out_file, XSTR (symbol, 0), buffer);
6486 #endif
6488 /* The default implementation of TARGET_USE_ANCHORS_FOR_SYMBOL_P. */
6490 bool
6491 default_use_anchors_for_symbol_p (const_rtx symbol)
6493 section *sect;
6494 tree decl;
6496 /* Don't use anchors for mergeable sections. The linker might move
6497 the objects around. */
6498 sect = SYMBOL_REF_BLOCK (symbol)->sect;
6499 if (sect->common.flags & SECTION_MERGE)
6500 return false;
6502 /* Don't use anchors for small data sections. The small data register
6503 acts as an anchor for such sections. */
6504 if (sect->common.flags & SECTION_SMALL)
6505 return false;
6507 decl = SYMBOL_REF_DECL (symbol);
6508 if (decl && DECL_P (decl))
6510 /* Don't use section anchors for decls that might be defined by
6511 other modules. */
6512 if (!targetm.binds_local_p (decl))
6513 return false;
6515 /* Don't use section anchors for decls that will be placed in a
6516 small data section. */
6517 /* ??? Ideally, this check would be redundant with the SECTION_SMALL
6518 one above. The problem is that we only use SECTION_SMALL for
6519 sections that should be marked as small in the section directive. */
6520 if (targetm.in_small_data_p (decl))
6521 return false;
6523 return true;
6526 /* Assume ELF-ish defaults, since that's pretty much the most liberal
6527 wrt cross-module name binding. */
6529 bool
6530 default_binds_local_p (const_tree exp)
6532 return default_binds_local_p_1 (exp, flag_shlib);
6535 bool
6536 default_binds_local_p_1 (const_tree exp, int shlib)
6538 bool local_p;
6540 /* A non-decl is an entry in the constant pool. */
6541 if (!DECL_P (exp))
6542 local_p = true;
6543 /* Weakrefs may not bind locally, even though the weakref itself is
6544 always static and therefore local. */
6545 else if (lookup_attribute ("weakref", DECL_ATTRIBUTES (exp)))
6546 local_p = false;
6547 /* Static variables are always local. */
6548 else if (! TREE_PUBLIC (exp))
6549 local_p = true;
6550 /* A variable is local if the user has said explicitly that it will
6551 be. */
6552 else if (DECL_VISIBILITY_SPECIFIED (exp)
6553 && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6554 local_p = true;
6555 /* Variables defined outside this object might not be local. */
6556 else if (DECL_EXTERNAL (exp))
6557 local_p = false;
6558 /* If defined in this object and visibility is not default, must be
6559 local. */
6560 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6561 local_p = true;
6562 /* Default visibility weak data can be overridden by a strong symbol
6563 in another module and so are not local. */
6564 else if (DECL_WEAK (exp))
6565 local_p = false;
6566 /* If PIC, then assume that any global name can be overridden by
6567 symbols resolved from other modules, unless we are compiling with
6568 -fwhole-program, which assumes that names are local. */
6569 else if (shlib)
6570 local_p = flag_whole_program;
6571 /* Uninitialized COMMON variable may be unified with symbols
6572 resolved from other modules. */
6573 else if (DECL_COMMON (exp)
6574 && (DECL_INITIAL (exp) == NULL
6575 || DECL_INITIAL (exp) == error_mark_node))
6576 local_p = false;
6577 /* Otherwise we're left with initialized (or non-common) global data
6578 which is of necessity defined locally. */
6579 else
6580 local_p = true;
6582 return local_p;
6585 /* Default function to output code that will globalize a label. A
6586 target must define GLOBAL_ASM_OP or provide its own function to
6587 globalize a label. */
6588 #ifdef GLOBAL_ASM_OP
6589 void
6590 default_globalize_label (FILE * stream, const char *name)
6592 fputs (GLOBAL_ASM_OP, stream);
6593 assemble_name (stream, name);
6594 putc ('\n', stream);
6596 #endif /* GLOBAL_ASM_OP */
6598 /* Default function to output code that will globalize a declaration. */
6599 void
6600 default_globalize_decl_name (FILE * stream, tree decl)
6602 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
6603 targetm.asm_out.globalize_label (stream, name);
6606 /* Default function to output a label for unwind information. The
6607 default is to do nothing. A target that needs nonlocal labels for
6608 unwind information must provide its own function to do this. */
6609 void
6610 default_emit_unwind_label (FILE * stream ATTRIBUTE_UNUSED,
6611 tree decl ATTRIBUTE_UNUSED,
6612 int for_eh ATTRIBUTE_UNUSED,
6613 int empty ATTRIBUTE_UNUSED)
6617 /* Default function to output a label to divide up the exception table.
6618 The default is to do nothing. A target that needs/wants to divide
6619 up the table must provide it's own function to do this. */
6620 void
6621 default_emit_except_table_label (FILE * stream ATTRIBUTE_UNUSED)
6625 /* This is how to output an internal numbered label where PREFIX is
6626 the class of label and LABELNO is the number within the class. */
6628 void
6629 default_internal_label (FILE *stream, const char *prefix,
6630 unsigned long labelno)
6632 char *const buf = (char *) alloca (40 + strlen (prefix));
6633 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
6634 ASM_OUTPUT_INTERNAL_LABEL (stream, buf);
6637 /* This is the default behavior at the beginning of a file. It's
6638 controlled by two other target-hook toggles. */
6639 void
6640 default_file_start (void)
6642 if (targetm.file_start_app_off
6643 && !(flag_verbose_asm || flag_debug_asm || flag_dump_rtl_in_asm))
6644 fputs (ASM_APP_OFF, asm_out_file);
6646 if (targetm.file_start_file_directive)
6647 output_file_directive (asm_out_file, main_input_filename);
6650 /* This is a generic routine suitable for use as TARGET_ASM_FILE_END
6651 which emits a special section directive used to indicate whether or
6652 not this object file needs an executable stack. This is primarily
6653 a GNU extension to ELF but could be used on other targets. */
6655 int trampolines_created;
6657 void
6658 file_end_indicate_exec_stack (void)
6660 unsigned int flags = SECTION_DEBUG;
6661 if (trampolines_created)
6662 flags |= SECTION_CODE;
6664 switch_to_section (get_section (".note.GNU-stack", flags, NULL));
6667 /* Output DIRECTIVE (a C string) followed by a newline. This is used as
6668 a get_unnamed_section callback. */
6670 void
6671 output_section_asm_op (const void *directive)
6673 fprintf (asm_out_file, "%s\n", (const char *) directive);
6676 /* Emit assembly code to switch to section NEW_SECTION. Do nothing if
6677 the current section is NEW_SECTION. */
6679 void
6680 switch_to_section (section *new_section)
6682 if (in_section == new_section)
6683 return;
6685 if (new_section->common.flags & SECTION_FORGET)
6686 in_section = NULL;
6687 else
6688 in_section = new_section;
6690 switch (SECTION_STYLE (new_section))
6692 case SECTION_NAMED:
6693 if (cfun
6694 && !crtl->subsections.unlikely_text_section_name
6695 && strcmp (new_section->named.name,
6696 UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
6697 crtl->subsections.unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
6699 targetm.asm_out.named_section (new_section->named.name,
6700 new_section->named.common.flags,
6701 new_section->named.decl);
6702 break;
6704 case SECTION_UNNAMED:
6705 new_section->unnamed.callback (new_section->unnamed.data);
6706 break;
6708 case SECTION_NOSWITCH:
6709 gcc_unreachable ();
6710 break;
6713 new_section->common.flags |= SECTION_DECLARED;
6716 /* If block symbol SYMBOL has not yet been assigned an offset, place
6717 it at the end of its block. */
6719 void
6720 place_block_symbol (rtx symbol)
6722 unsigned HOST_WIDE_INT size, mask, offset;
6723 struct constant_descriptor_rtx *desc;
6724 unsigned int alignment;
6725 struct object_block *block;
6726 tree decl;
6728 gcc_assert (SYMBOL_REF_BLOCK (symbol));
6729 if (SYMBOL_REF_BLOCK_OFFSET (symbol) >= 0)
6730 return;
6732 /* Work out the symbol's size and alignment. */
6733 if (CONSTANT_POOL_ADDRESS_P (symbol))
6735 desc = SYMBOL_REF_CONSTANT (symbol);
6736 alignment = desc->align;
6737 size = GET_MODE_SIZE (desc->mode);
6739 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6741 decl = SYMBOL_REF_DECL (symbol);
6742 alignment = get_constant_alignment (decl);
6743 size = get_constant_size (decl);
6745 else
6747 decl = SYMBOL_REF_DECL (symbol);
6748 alignment = DECL_ALIGN (decl);
6749 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6752 /* Calculate the object's offset from the start of the block. */
6753 block = SYMBOL_REF_BLOCK (symbol);
6754 mask = alignment / BITS_PER_UNIT - 1;
6755 offset = (block->size + mask) & ~mask;
6756 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
6758 /* Record the block's new alignment and size. */
6759 block->alignment = MAX (block->alignment, alignment);
6760 block->size = offset + size;
6762 VEC_safe_push (rtx, gc, block->objects, symbol);
6765 /* Return the anchor that should be used to address byte offset OFFSET
6766 from the first object in BLOCK. MODEL is the TLS model used
6767 to access it. */
6770 get_section_anchor (struct object_block *block, HOST_WIDE_INT offset,
6771 enum tls_model model)
6773 char label[100];
6774 unsigned int begin, middle, end;
6775 unsigned HOST_WIDE_INT min_offset, max_offset, range, bias, delta;
6776 rtx anchor;
6778 /* Work out the anchor's offset. Use an offset of 0 for the first
6779 anchor so that we don't pessimize the case where we take the address
6780 of a variable at the beginning of the block. This is particularly
6781 useful when a block has only one variable assigned to it.
6783 We try to place anchors RANGE bytes apart, so there can then be
6784 anchors at +/-RANGE, +/-2 * RANGE, and so on, up to the limits of
6785 a ptr_mode offset. With some target settings, the lowest such
6786 anchor might be out of range for the lowest ptr_mode offset;
6787 likewise the highest anchor for the highest offset. Use anchors
6788 at the extreme ends of the ptr_mode range in such cases.
6790 All arithmetic uses unsigned integers in order to avoid
6791 signed overflow. */
6792 max_offset = (unsigned HOST_WIDE_INT) targetm.max_anchor_offset;
6793 min_offset = (unsigned HOST_WIDE_INT) targetm.min_anchor_offset;
6794 range = max_offset - min_offset + 1;
6795 if (range == 0)
6796 offset = 0;
6797 else
6799 bias = 1 << (GET_MODE_BITSIZE (ptr_mode) - 1);
6800 if (offset < 0)
6802 delta = -(unsigned HOST_WIDE_INT) offset + max_offset;
6803 delta -= delta % range;
6804 if (delta > bias)
6805 delta = bias;
6806 offset = (HOST_WIDE_INT) (-delta);
6808 else
6810 delta = (unsigned HOST_WIDE_INT) offset - min_offset;
6811 delta -= delta % range;
6812 if (delta > bias - 1)
6813 delta = bias - 1;
6814 offset = (HOST_WIDE_INT) delta;
6818 /* Do a binary search to see if there's already an anchor we can use.
6819 Set BEGIN to the new anchor's index if not. */
6820 begin = 0;
6821 end = VEC_length (rtx, block->anchors);
6822 while (begin != end)
6824 middle = (end + begin) / 2;
6825 anchor = VEC_index (rtx, block->anchors, middle);
6826 if (SYMBOL_REF_BLOCK_OFFSET (anchor) > offset)
6827 end = middle;
6828 else if (SYMBOL_REF_BLOCK_OFFSET (anchor) < offset)
6829 begin = middle + 1;
6830 else if (SYMBOL_REF_TLS_MODEL (anchor) > model)
6831 end = middle;
6832 else if (SYMBOL_REF_TLS_MODEL (anchor) < model)
6833 begin = middle + 1;
6834 else
6835 return anchor;
6838 /* Create a new anchor with a unique label. */
6839 ASM_GENERATE_INTERNAL_LABEL (label, "LANCHOR", anchor_labelno++);
6840 anchor = create_block_symbol (ggc_strdup (label), block, offset);
6841 SYMBOL_REF_FLAGS (anchor) |= SYMBOL_FLAG_LOCAL | SYMBOL_FLAG_ANCHOR;
6842 SYMBOL_REF_FLAGS (anchor) |= model << SYMBOL_FLAG_TLS_SHIFT;
6844 /* Insert it at index BEGIN. */
6845 VEC_safe_insert (rtx, gc, block->anchors, begin, anchor);
6846 return anchor;
6849 /* Output the objects in BLOCK. */
6851 static void
6852 output_object_block (struct object_block *block)
6854 struct constant_descriptor_rtx *desc;
6855 unsigned int i;
6856 HOST_WIDE_INT offset;
6857 tree decl;
6858 rtx symbol;
6860 if (block->objects == NULL)
6861 return;
6863 /* Switch to the section and make sure that the first byte is
6864 suitably aligned. */
6865 switch_to_section (block->sect);
6866 assemble_align (block->alignment);
6868 /* Define the values of all anchors relative to the current section
6869 position. */
6870 for (i = 0; VEC_iterate (rtx, block->anchors, i, symbol); i++)
6871 targetm.asm_out.output_anchor (symbol);
6873 /* Output the objects themselves. */
6874 offset = 0;
6875 for (i = 0; VEC_iterate (rtx, block->objects, i, symbol); i++)
6877 /* Move to the object's offset, padding with zeros if necessary. */
6878 assemble_zeros (SYMBOL_REF_BLOCK_OFFSET (symbol) - offset);
6879 offset = SYMBOL_REF_BLOCK_OFFSET (symbol);
6880 if (CONSTANT_POOL_ADDRESS_P (symbol))
6882 desc = SYMBOL_REF_CONSTANT (symbol);
6883 output_constant_pool_1 (desc, 1);
6884 offset += GET_MODE_SIZE (desc->mode);
6886 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6888 decl = SYMBOL_REF_DECL (symbol);
6889 assemble_constant_contents (decl, XSTR (symbol, 0),
6890 get_constant_alignment (decl));
6891 offset += get_constant_size (decl);
6893 else
6895 decl = SYMBOL_REF_DECL (symbol);
6896 assemble_variable_contents (decl, XSTR (symbol, 0), false);
6897 offset += tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6902 /* A htab_traverse callback used to call output_object_block for
6903 each member of object_block_htab. */
6905 static int
6906 output_object_block_htab (void **slot, void *data ATTRIBUTE_UNUSED)
6908 output_object_block ((struct object_block *) (*slot));
6909 return 1;
6912 /* Output the definitions of all object_blocks. */
6914 void
6915 output_object_blocks (void)
6917 htab_traverse (object_block_htab, output_object_block_htab, NULL);
6920 /* This function provides a possible implementation of the
6921 TARGET_ASM_RECORD_GCC_SWITCHES target hook for ELF targets. When triggered
6922 by -frecord-gcc-switches it creates a new mergeable, string section in the
6923 assembler output file called TARGET_ASM_RECORD_GCC_SWITCHES_SECTION which
6924 contains the switches in ASCII format.
6926 FIXME: This code does not correctly handle double quote characters
6927 that appear inside strings, (it strips them rather than preserving them).
6928 FIXME: ASM_OUTPUT_ASCII, as defined in config/elfos.h will not emit NUL
6929 characters - instead it treats them as sub-string separators. Since
6930 we want to emit NUL strings terminators into the object file we have to use
6931 ASM_OUTPUT_SKIP. */
6934 elf_record_gcc_switches (print_switch_type type, const char * name)
6936 static char buffer[1024];
6938 /* This variable is used as part of a simplistic heuristic to detect
6939 command line switches which take an argument:
6941 "If a command line option does not start with a dash then
6942 it is an argument for the previous command line option."
6944 This fails in the case of the command line option which is the name
6945 of the file to compile, but otherwise it is pretty reasonable. */
6946 static bool previous_name_held_back = FALSE;
6948 switch (type)
6950 case SWITCH_TYPE_PASSED:
6951 if (* name != '-')
6953 if (previous_name_held_back)
6955 unsigned int len = strlen (buffer);
6957 snprintf (buffer + len, sizeof buffer - len, " %s", name);
6958 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6959 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6960 previous_name_held_back = FALSE;
6962 else
6964 strncpy (buffer, name, sizeof buffer);
6965 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6966 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6969 else
6971 if (previous_name_held_back)
6973 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6974 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6977 strncpy (buffer, name, sizeof buffer);
6978 previous_name_held_back = TRUE;
6980 break;
6982 case SWITCH_TYPE_DESCRIPTIVE:
6983 if (name == NULL)
6985 /* Distinguish between invocations where name is NULL. */
6986 static bool started = false;
6988 if (started)
6990 if (previous_name_held_back)
6992 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6993 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6996 else
6998 section * sec;
7000 sec = get_section (targetm.asm_out.record_gcc_switches_section,
7001 SECTION_DEBUG
7002 | SECTION_MERGE
7003 | SECTION_STRINGS
7004 | (SECTION_ENTSIZE & 1),
7005 NULL);
7006 switch_to_section (sec);
7007 started = true;
7011 default:
7012 break;
7015 /* The return value is currently ignored by the caller, but must be 0.
7016 For -fverbose-asm the return value would be the number of characters
7017 emitted into the assembler file. */
7018 return 0;
7021 /* Emit text to declare externally defined symbols. It is needed to
7022 properly support non-default visibility. */
7023 void
7024 default_elf_asm_output_external (FILE *file ATTRIBUTE_UNUSED,
7025 tree decl,
7026 const char *name ATTRIBUTE_UNUSED)
7028 /* We output the name if and only if TREE_SYMBOL_REFERENCED is
7029 set in order to avoid putting out names that are never really
7030 used. */
7031 if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))
7032 && targetm.binds_local_p (decl))
7033 maybe_assemble_visibility (decl);
7036 #include "gt-varasm.h"