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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
4 Free Software Foundation, Inc.
5
6 This file is part of GCC.
7
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.
12
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.
17
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/>. */
21
22
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.
26
27 We also output the assembler code for constants stored in memory
28 and are responsible for combining constants with the same value. */
29
30 #include "config.h"
31 #include "system.h"
32 #include "coretypes.h"
33 #include "tm.h"
34 #include "rtl.h"
35 #include "tree.h"
36 #include "flags.h"
37 #include "function.h"
38 #include "expr.h"
39 #include "hard-reg-set.h"
40 #include "regs.h"
41 #include "real.h"
42 #include "output.h"
43 #include "toplev.h"
44 #include "hashtab.h"
45 #include "c-pragma.h"
46 #include "ggc.h"
47 #include "langhooks.h"
48 #include "tm_p.h"
49 #include "debug.h"
50 #include "target.h"
51 #include "targhooks.h"
52 #include "tree-mudflap.h"
53 #include "cgraph.h"
54 #include "cfglayout.h"
55 #include "basic-block.h"
56 #include "tree-iterator.h"
57
58 #ifdef XCOFF_DEBUGGING_INFO
59 #include "xcoffout.h" /* Needed for external data
60 declarations for e.g. AIX 4.x. */
61 #endif
62
63 /* The (assembler) name of the first globally-visible object output. */
64 extern GTY(()) const char *first_global_object_name;
65 extern GTY(()) const char *weak_global_object_name;
66
67 const char *first_global_object_name;
68 const char *weak_global_object_name;
69
70 struct addr_const;
71 struct constant_descriptor_rtx;
72 struct rtx_constant_pool;
73
74 #define n_deferred_constants (crtl->varasm.deferred_constants)
75
76 /* Number for making the label on the next
77 constant that is stored in memory. */
78
79 static GTY(()) int const_labelno;
80
81 /* Carry information from ASM_DECLARE_OBJECT_NAME
82 to ASM_FINISH_DECLARE_OBJECT. */
83
84 int size_directive_output;
85
86 /* The last decl for which assemble_variable was called,
87 if it did ASM_DECLARE_OBJECT_NAME.
88 If the last call to assemble_variable didn't do that,
89 this holds 0. */
90
91 tree last_assemble_variable_decl;
92
93 /* The following global variable indicates if the first basic block
94 in a function belongs to the cold partition or not. */
95
96 bool first_function_block_is_cold;
97
98 /* We give all constants their own alias set. Perhaps redundant with
99 MEM_READONLY_P, but pre-dates it. */
100
101 static alias_set_type const_alias_set;
102
103 static const char *strip_reg_name (const char *);
104 static int contains_pointers_p (tree);
105 #ifdef ASM_OUTPUT_EXTERNAL
106 static bool incorporeal_function_p (tree);
107 #endif
108 static void decode_addr_const (tree, struct addr_const *);
109 static hashval_t const_desc_hash (const void *);
110 static int const_desc_eq (const void *, const void *);
111 static hashval_t const_hash_1 (const tree);
112 static int compare_constant (const tree, const tree);
113 static tree copy_constant (tree);
114 static void output_constant_def_contents (rtx);
115 static void output_addressed_constants (tree);
116 static unsigned HOST_WIDE_INT array_size_for_constructor (tree);
117 static unsigned min_align (unsigned, unsigned);
118 static void output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int);
119 static void globalize_decl (tree);
120 #ifdef BSS_SECTION_ASM_OP
121 #ifdef ASM_OUTPUT_BSS
122 static void asm_output_bss (FILE *, tree, const char *,
123 unsigned HOST_WIDE_INT, unsigned HOST_WIDE_INT);
124 #endif
125 #ifdef ASM_OUTPUT_ALIGNED_BSS
126 static void asm_output_aligned_bss (FILE *, tree, const char *,
127 unsigned HOST_WIDE_INT, int)
128 ATTRIBUTE_UNUSED;
129 #endif
130 #endif /* BSS_SECTION_ASM_OP */
131 static void mark_weak (tree);
132 static void output_constant_pool (const char *, tree);
133 \f
134 /* Well-known sections, each one associated with some sort of *_ASM_OP. */
135 section *text_section;
136 section *data_section;
137 section *readonly_data_section;
138 section *sdata_section;
139 section *ctors_section;
140 section *dtors_section;
141 section *bss_section;
142 section *sbss_section;
143
144 /* Various forms of common section. All are guaranteed to be nonnull. */
145 section *tls_comm_section;
146 section *comm_section;
147 section *lcomm_section;
148
149 /* A SECTION_NOSWITCH section used for declaring global BSS variables.
150 May be null. */
151 section *bss_noswitch_section;
152
153 /* The section that holds the main exception table, when known. The section
154 is set either by the target's init_sections hook or by the first call to
155 switch_to_exception_section. */
156 section *exception_section;
157
158 /* The section that holds the DWARF2 frame unwind information, when known.
159 The section is set either by the target's init_sections hook or by the
160 first call to switch_to_eh_frame_section. */
161 section *eh_frame_section;
162
163 /* asm_out_file's current section. This is NULL if no section has yet
164 been selected or if we lose track of what the current section is. */
165 section *in_section;
166
167 /* True if code for the current function is currently being directed
168 at the cold section. */
169 bool in_cold_section_p;
170
171 /* A linked list of all the unnamed sections. */
172 static GTY(()) section *unnamed_sections;
173
174 /* Return a nonzero value if DECL has a section attribute. */
175 #ifndef IN_NAMED_SECTION
176 #define IN_NAMED_SECTION(DECL) \
177 ((TREE_CODE (DECL) == FUNCTION_DECL || TREE_CODE (DECL) == VAR_DECL) \
178 && DECL_SECTION_NAME (DECL) != NULL_TREE)
179 #endif
180
181 /* Hash table of named sections. */
182 static GTY((param_is (section))) htab_t section_htab;
183
184 /* A table of object_blocks, indexed by section. */
185 static GTY((param_is (struct object_block))) htab_t object_block_htab;
186
187 /* The next number to use for internal anchor labels. */
188 static GTY(()) int anchor_labelno;
189
190 /* A pool of constants that can be shared between functions. */
191 static GTY(()) struct rtx_constant_pool *shared_constant_pool;
192
193 /* TLS emulation. */
194
195 static GTY ((if_marked ("tree_map_marked_p"), param_is (struct tree_map)))
196 htab_t emutls_htab;
197 static GTY (()) tree emutls_object_type;
198 /* Emulated TLS objects have the TLS model TLS_MODEL_EMULATED. This
199 macro can be used on them to distinguish the control variable from
200 the initialization template. */
201 #define DECL_EMUTLS_VAR_P(D) (TREE_TYPE (D) == emutls_object_type)
202
203 #if !defined (NO_DOT_IN_LABEL)
204 # define EMUTLS_SEPARATOR "."
205 #elif !defined (NO_DOLLAR_IN_LABEL)
206 # define EMUTLS_SEPARATOR "$"
207 #else
208 # define EMUTLS_SEPARATOR "_"
209 #endif
210
211 /* Create an IDENTIFIER_NODE by prefixing PREFIX to the
212 IDENTIFIER_NODE NAME's name. */
213
214 static tree
215 prefix_name (const char *prefix, tree name)
216 {
217 unsigned plen = strlen (prefix);
218 unsigned nlen = strlen (IDENTIFIER_POINTER (name));
219 char *toname = (char *) alloca (plen + nlen + 1);
220
221 memcpy (toname, prefix, plen);
222 memcpy (toname + plen, IDENTIFIER_POINTER (name), nlen + 1);
223
224 return get_identifier (toname);
225 }
226
227 /* Create an identifier for the struct __emutls_object, given an identifier
228 of the DECL_ASSEMBLY_NAME of the original object. */
229
230 static tree
231 get_emutls_object_name (tree name)
232 {
233 const char *prefix = (targetm.emutls.var_prefix
234 ? targetm.emutls.var_prefix
235 : "__emutls_v" EMUTLS_SEPARATOR);
236 return prefix_name (prefix, name);
237 }
238
239 tree
240 default_emutls_var_fields (tree type, tree *name ATTRIBUTE_UNUSED)
241 {
242 tree word_type_node, field, next_field;
243
244 field = build_decl (FIELD_DECL, get_identifier ("__templ"), ptr_type_node);
245 DECL_CONTEXT (field) = type;
246 next_field = field;
247
248 field = build_decl (FIELD_DECL, get_identifier ("__offset"),
249 ptr_type_node);
250 DECL_CONTEXT (field) = type;
251 TREE_CHAIN (field) = next_field;
252 next_field = field;
253
254 word_type_node = lang_hooks.types.type_for_mode (word_mode, 1);
255 field = build_decl (FIELD_DECL, get_identifier ("__align"),
256 word_type_node);
257 DECL_CONTEXT (field) = type;
258 TREE_CHAIN (field) = next_field;
259 next_field = field;
260
261 field = build_decl (FIELD_DECL, get_identifier ("__size"), word_type_node);
262 DECL_CONTEXT (field) = type;
263 TREE_CHAIN (field) = next_field;
264
265 return field;
266 }
267
268 /* Create the structure for struct __emutls_object. This should match the
269 structure at the top of emutls.c, modulo the union there. */
270
271 static tree
272 get_emutls_object_type (void)
273 {
274 tree type, type_name, field;
275
276 type = emutls_object_type;
277 if (type)
278 return type;
279
280 emutls_object_type = type = lang_hooks.types.make_type (RECORD_TYPE);
281 type_name = NULL;
282 field = targetm.emutls.var_fields (type, &type_name);
283 if (!type_name)
284 type_name = get_identifier ("__emutls_object");
285 type_name = build_decl (TYPE_DECL, type_name, type);
286 TYPE_NAME (type) = type_name;
287 TYPE_FIELDS (type) = field;
288 layout_type (type);
289
290 return type;
291 }
292
293 /* Create a read-only variable like DECL, with the same DECL_INITIAL.
294 This will be used for initializing the emulated tls data area. */
295
296 static tree
297 get_emutls_init_templ_addr (tree decl)
298 {
299 tree name, to;
300
301 if (targetm.emutls.register_common && !DECL_INITIAL (decl)
302 && !DECL_SECTION_NAME (decl))
303 return null_pointer_node;
304
305 name = DECL_ASSEMBLER_NAME (decl);
306 if (!targetm.emutls.tmpl_prefix || targetm.emutls.tmpl_prefix[0])
307 {
308 const char *prefix = (targetm.emutls.tmpl_prefix
309 ? targetm.emutls.tmpl_prefix
310 : "__emutls_t" EMUTLS_SEPARATOR);
311 name = prefix_name (prefix, name);
312 }
313
314 to = build_decl (VAR_DECL, name, TREE_TYPE (decl));
315 SET_DECL_ASSEMBLER_NAME (to, DECL_NAME (to));
316 DECL_TLS_MODEL (to) = TLS_MODEL_EMULATED;
317 DECL_ARTIFICIAL (to) = 1;
318 TREE_USED (to) = TREE_USED (decl);
319 TREE_READONLY (to) = 1;
320 DECL_IGNORED_P (to) = 1;
321 DECL_CONTEXT (to) = DECL_CONTEXT (decl);
322 DECL_SECTION_NAME (to) = DECL_SECTION_NAME (decl);
323
324 DECL_WEAK (to) = DECL_WEAK (decl);
325 if (DECL_ONE_ONLY (decl))
326 {
327 make_decl_one_only (to);
328 TREE_STATIC (to) = TREE_STATIC (decl);
329 TREE_PUBLIC (to) = TREE_PUBLIC (decl);
330 DECL_VISIBILITY (to) = DECL_VISIBILITY (decl);
331 }
332 else
333 TREE_STATIC (to) = 1;
334
335 DECL_INITIAL (to) = DECL_INITIAL (decl);
336 DECL_INITIAL (decl) = NULL;
337
338 varpool_finalize_decl (to);
339 return build_fold_addr_expr (to);
340 }
341
342 /* When emulating tls, we use a control structure for use by the runtime.
343 Create and return this structure. */
344
345 tree
346 emutls_decl (tree decl)
347 {
348 tree name, to;
349 struct tree_map *h, in;
350 void **loc;
351
352 if (targetm.have_tls || decl == NULL || decl == error_mark_node
353 || TREE_CODE (decl) != VAR_DECL || ! DECL_THREAD_LOCAL_P (decl))
354 return decl;
355
356 /* Look up the object in the hash; return the control structure if
357 it has already been created. */
358 if (! emutls_htab)
359 emutls_htab = htab_create_ggc (512, tree_map_hash, tree_map_eq, 0);
360
361 name = DECL_ASSEMBLER_NAME (decl);
362
363 /* Note that we use the hash of the decl's name, rather than a hash
364 of the decl's pointer. In emutls_finish we iterate through the
365 hash table, and we want this traversal to be predictable. */
366 in.hash = htab_hash_string (IDENTIFIER_POINTER (name));
367 in.base.from = decl;
368 loc = htab_find_slot_with_hash (emutls_htab, &in, in.hash, INSERT);
369 h = (struct tree_map *) *loc;
370 if (h != NULL)
371 to = h->to;
372 else
373 {
374 to = build_decl (VAR_DECL, get_emutls_object_name (name),
375 get_emutls_object_type ());
376
377 h = GGC_NEW (struct tree_map);
378 h->hash = in.hash;
379 h->base.from = decl;
380 h->to = to;
381 *(struct tree_map **) loc = h;
382
383 DECL_TLS_MODEL (to) = TLS_MODEL_EMULATED;
384 DECL_ARTIFICIAL (to) = 1;
385 DECL_IGNORED_P (to) = 1;
386 TREE_READONLY (to) = 0;
387 SET_DECL_ASSEMBLER_NAME (to, DECL_NAME (to));
388 if (DECL_ONE_ONLY (decl))
389 make_decl_one_only (to);
390 DECL_CONTEXT (to) = DECL_CONTEXT (decl);
391 if (targetm.emutls.var_align_fixed)
392 /* If we're not allowed to change the proxy object's
393 alignment, pretend it's been set by the user. */
394 DECL_USER_ALIGN (to) = 1;
395 }
396
397 /* Note that these fields may need to be updated from time to time from
398 the original decl. Consider:
399 extern __thread int i;
400 int foo() { return i; }
401 __thread int i = 1;
402 in which I goes from external to locally defined and initialized. */
403
404 TREE_STATIC (to) = TREE_STATIC (decl);
405 TREE_USED (to) = TREE_USED (decl);
406 TREE_PUBLIC (to) = TREE_PUBLIC (decl);
407 DECL_EXTERNAL (to) = DECL_EXTERNAL (decl);
408 DECL_COMMON (to) = DECL_COMMON (decl);
409 DECL_WEAK (to) = DECL_WEAK (decl);
410 DECL_VISIBILITY (to) = DECL_VISIBILITY (decl);
411
412 return to;
413 }
414
415 static int
416 emutls_common_1 (void **loc, void *xstmts)
417 {
418 struct tree_map *h = *(struct tree_map **) loc;
419 tree args, x, *pstmts = (tree *) xstmts;
420 tree word_type_node;
421
422 if (! DECL_COMMON (h->base.from)
423 || (DECL_INITIAL (h->base.from)
424 && DECL_INITIAL (h->base.from) != error_mark_node))
425 return 1;
426
427 word_type_node = lang_hooks.types.type_for_mode (word_mode, 1);
428
429 /* The idea was to call get_emutls_init_templ_addr here, but if we
430 do this and there is an initializer, -fanchor_section loses,
431 because it would be too late to ensure the template is
432 output. */
433 x = null_pointer_node;
434 args = tree_cons (NULL, x, NULL);
435 x = build_int_cst (word_type_node, DECL_ALIGN_UNIT (h->base.from));
436 args = tree_cons (NULL, x, args);
437 x = fold_convert (word_type_node, DECL_SIZE_UNIT (h->base.from));
438 args = tree_cons (NULL, x, args);
439 x = build_fold_addr_expr (h->to);
440 args = tree_cons (NULL, x, args);
441
442 x = built_in_decls[BUILT_IN_EMUTLS_REGISTER_COMMON];
443 x = build_function_call_expr (x, args);
444
445 append_to_statement_list (x, pstmts);
446 return 1;
447 }
448
449 void
450 emutls_finish (void)
451 {
452 if (targetm.emutls.register_common)
453 {
454 tree body = NULL_TREE;
455
456 if (emutls_htab == NULL)
457 return;
458
459 htab_traverse_noresize (emutls_htab, emutls_common_1, &body);
460 if (body == NULL_TREE)
461 return;
462
463 cgraph_build_static_cdtor ('I', body, DEFAULT_INIT_PRIORITY);
464 }
465 }
466
467 /* Helper routines for maintaining section_htab. */
468
469 static int
470 section_entry_eq (const void *p1, const void *p2)
471 {
472 const section *old = (const section *) p1;
473 const char *new_name = (const char *) p2;
474
475 return strcmp (old->named.name, new_name) == 0;
476 }
477
478 static hashval_t
479 section_entry_hash (const void *p)
480 {
481 const section *old = (const section *) p;
482 return htab_hash_string (old->named.name);
483 }
484
485 /* Return a hash value for section SECT. */
486
487 static hashval_t
488 hash_section (section *sect)
489 {
490 if (sect->common.flags & SECTION_NAMED)
491 return htab_hash_string (sect->named.name);
492 return sect->common.flags;
493 }
494
495 /* Helper routines for maintaining object_block_htab. */
496
497 static int
498 object_block_entry_eq (const void *p1, const void *p2)
499 {
500 const struct object_block *old = (const struct object_block *) p1;
501 const section *new_section = (const section *) p2;
502
503 return old->sect == new_section;
504 }
505
506 static hashval_t
507 object_block_entry_hash (const void *p)
508 {
509 const struct object_block *old = (const struct object_block *) p;
510 return hash_section (old->sect);
511 }
512
513 /* Return a new unnamed section with the given fields. */
514
515 section *
516 get_unnamed_section (unsigned int flags, void (*callback) (const void *),
517 const void *data)
518 {
519 section *sect;
520
521 sect = GGC_NEW (section);
522 sect->unnamed.common.flags = flags | SECTION_UNNAMED;
523 sect->unnamed.callback = callback;
524 sect->unnamed.data = data;
525 sect->unnamed.next = unnamed_sections;
526
527 unnamed_sections = sect;
528 return sect;
529 }
530
531 /* Return a SECTION_NOSWITCH section with the given fields. */
532
533 static section *
534 get_noswitch_section (unsigned int flags, noswitch_section_callback callback)
535 {
536 section *sect;
537
538 sect = GGC_NEW (section);
539 sect->noswitch.common.flags = flags | SECTION_NOSWITCH;
540 sect->noswitch.callback = callback;
541
542 return sect;
543 }
544
545 /* Return the named section structure associated with NAME. Create
546 a new section with the given fields if no such structure exists. */
547
548 section *
549 get_section (const char *name, unsigned int flags, tree decl)
550 {
551 section *sect, **slot;
552
553 slot = (section **)
554 htab_find_slot_with_hash (section_htab, name,
555 htab_hash_string (name), INSERT);
556 flags |= SECTION_NAMED;
557 if (*slot == NULL)
558 {
559 sect = GGC_NEW (section);
560 sect->named.common.flags = flags;
561 sect->named.name = ggc_strdup (name);
562 sect->named.decl = decl;
563 *slot = sect;
564 }
565 else
566 {
567 sect = *slot;
568 if ((sect->common.flags & ~SECTION_DECLARED) != flags
569 && ((sect->common.flags | flags) & SECTION_OVERRIDE) == 0)
570 {
571 /* Sanity check user variables for flag changes. */
572 if (decl == 0)
573 decl = sect->named.decl;
574 gcc_assert (decl);
575 error ("%+D causes a section type conflict", decl);
576 }
577 }
578 return sect;
579 }
580
581 /* Return true if the current compilation mode benefits from having
582 objects grouped into blocks. */
583
584 static bool
585 use_object_blocks_p (void)
586 {
587 return flag_section_anchors;
588 }
589
590 /* Return the object_block structure for section SECT. Create a new
591 structure if we haven't created one already. Return null if SECT
592 itself is null. */
593
594 static struct object_block *
595 get_block_for_section (section *sect)
596 {
597 struct object_block *block;
598 void **slot;
599
600 if (sect == NULL)
601 return NULL;
602
603 slot = htab_find_slot_with_hash (object_block_htab, sect,
604 hash_section (sect), INSERT);
605 block = (struct object_block *) *slot;
606 if (block == NULL)
607 {
608 block = (struct object_block *)
609 ggc_alloc_cleared (sizeof (struct object_block));
610 block->sect = sect;
611 *slot = block;
612 }
613 return block;
614 }
615
616 /* Create a symbol with label LABEL and place it at byte offset
617 OFFSET in BLOCK. OFFSET can be negative if the symbol's offset
618 is not yet known. LABEL must be a garbage-collected string. */
619
620 static rtx
621 create_block_symbol (const char *label, struct object_block *block,
622 HOST_WIDE_INT offset)
623 {
624 rtx symbol;
625 unsigned int size;
626
627 /* Create the extended SYMBOL_REF. */
628 size = RTX_HDR_SIZE + sizeof (struct block_symbol);
629 symbol = (rtx) ggc_alloc_zone (size, &rtl_zone);
630
631 /* Initialize the normal SYMBOL_REF fields. */
632 memset (symbol, 0, size);
633 PUT_CODE (symbol, SYMBOL_REF);
634 PUT_MODE (symbol, Pmode);
635 XSTR (symbol, 0) = label;
636 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_HAS_BLOCK_INFO;
637
638 /* Initialize the block_symbol stuff. */
639 SYMBOL_REF_BLOCK (symbol) = block;
640 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
641
642 return symbol;
643 }
644
645 static void
646 initialize_cold_section_name (void)
647 {
648 const char *stripped_name;
649 char *name, *buffer;
650 tree dsn;
651
652 gcc_assert (cfun && current_function_decl);
653 if (crtl->subsections.unlikely_text_section_name)
654 return;
655
656 dsn = DECL_SECTION_NAME (current_function_decl);
657 if (flag_function_sections && dsn)
658 {
659 name = (char *) alloca (TREE_STRING_LENGTH (dsn) + 1);
660 memcpy (name, TREE_STRING_POINTER (dsn), TREE_STRING_LENGTH (dsn) + 1);
661
662 stripped_name = targetm.strip_name_encoding (name);
663
664 buffer = ACONCAT ((stripped_name, "_unlikely", NULL));
665 crtl->subsections.unlikely_text_section_name = ggc_strdup (buffer);
666 }
667 else
668 crtl->subsections.unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
669 }
670
671 /* Tell assembler to switch to unlikely-to-be-executed text section. */
672
673 section *
674 unlikely_text_section (void)
675 {
676 if (cfun)
677 {
678 if (!crtl->subsections.unlikely_text_section_name)
679 initialize_cold_section_name ();
680
681 return get_named_section (NULL, crtl->subsections.unlikely_text_section_name, 0);
682 }
683 else
684 return get_named_section (NULL, UNLIKELY_EXECUTED_TEXT_SECTION_NAME, 0);
685 }
686
687 /* When called within a function context, return true if the function
688 has been assigned a cold text section and if SECT is that section.
689 When called outside a function context, return true if SECT is the
690 default cold section. */
691
692 bool
693 unlikely_text_section_p (section *sect)
694 {
695 const char *name;
696
697 if (cfun)
698 name = crtl->subsections.unlikely_text_section_name;
699 else
700 name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
701
702 return (name
703 && sect
704 && SECTION_STYLE (sect) == SECTION_NAMED
705 && strcmp (name, sect->named.name) == 0);
706 }
707
708 /* Return a section with a particular name and with whatever SECTION_*
709 flags section_type_flags deems appropriate. The name of the section
710 is taken from NAME if nonnull, otherwise it is taken from DECL's
711 DECL_SECTION_NAME. DECL is the decl associated with the section
712 (see the section comment for details) and RELOC is as for
713 section_type_flags. */
714
715 section *
716 get_named_section (tree decl, const char *name, int reloc)
717 {
718 unsigned int flags;
719
720 gcc_assert (!decl || DECL_P (decl));
721 if (name == NULL)
722 name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
723
724 flags = targetm.section_type_flags (decl, name, reloc);
725
726 return get_section (name, flags, decl);
727 }
728
729 /* If required, set DECL_SECTION_NAME to a unique name. */
730
731 void
732 resolve_unique_section (tree decl, int reloc ATTRIBUTE_UNUSED,
733 int flag_function_or_data_sections)
734 {
735 if (DECL_SECTION_NAME (decl) == NULL_TREE
736 && targetm.have_named_sections
737 && (flag_function_or_data_sections
738 || DECL_ONE_ONLY (decl)))
739 targetm.asm_out.unique_section (decl, reloc);
740 }
741
742 #ifdef BSS_SECTION_ASM_OP
743
744 #ifdef ASM_OUTPUT_BSS
745
746 /* Utility function for ASM_OUTPUT_BSS for targets to use if
747 they don't support alignments in .bss.
748 ??? It is believed that this function will work in most cases so such
749 support is localized here. */
750
751 static void
752 asm_output_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
753 const char *name,
754 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
755 unsigned HOST_WIDE_INT rounded)
756 {
757 gcc_assert (strcmp (XSTR (XEXP (DECL_RTL (decl), 0), 0), name) == 0);
758 targetm.asm_out.globalize_decl_name (file, decl);
759 switch_to_section (bss_section);
760 #ifdef ASM_DECLARE_OBJECT_NAME
761 last_assemble_variable_decl = decl;
762 ASM_DECLARE_OBJECT_NAME (file, name, decl);
763 #else
764 /* Standard thing is just output label for the object. */
765 ASM_OUTPUT_LABEL (file, name);
766 #endif /* ASM_DECLARE_OBJECT_NAME */
767 ASM_OUTPUT_SKIP (file, rounded ? rounded : 1);
768 }
769
770 #endif
771
772 #ifdef ASM_OUTPUT_ALIGNED_BSS
773
774 /* Utility function for targets to use in implementing
775 ASM_OUTPUT_ALIGNED_BSS.
776 ??? It is believed that this function will work in most cases so such
777 support is localized here. */
778
779 static void
780 asm_output_aligned_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
781 const char *name, unsigned HOST_WIDE_INT size,
782 int align)
783 {
784 switch_to_section (bss_section);
785 ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
786 #ifdef ASM_DECLARE_OBJECT_NAME
787 last_assemble_variable_decl = decl;
788 ASM_DECLARE_OBJECT_NAME (file, name, decl);
789 #else
790 /* Standard thing is just output label for the object. */
791 ASM_OUTPUT_LABEL (file, name);
792 #endif /* ASM_DECLARE_OBJECT_NAME */
793 ASM_OUTPUT_SKIP (file, size ? size : 1);
794 }
795
796 #endif
797
798 #endif /* BSS_SECTION_ASM_OP */
799
800 #ifndef USE_SELECT_SECTION_FOR_FUNCTIONS
801 /* Return the hot section for function DECL. Return text_section for
802 null DECLs. */
803
804 static section *
805 hot_function_section (tree decl)
806 {
807 if (decl != NULL_TREE
808 && DECL_SECTION_NAME (decl) != NULL_TREE
809 && targetm.have_named_sections)
810 return get_named_section (decl, NULL, 0);
811 else
812 return text_section;
813 }
814 #endif
815
816 /* Return the section for function DECL.
817
818 If DECL is NULL_TREE, return the text section. We can be passed
819 NULL_TREE under some circumstances by dbxout.c at least. */
820
821 section *
822 function_section (tree decl)
823 {
824 int reloc = 0;
825
826 if (first_function_block_is_cold)
827 reloc = 1;
828
829 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
830 if (decl != NULL_TREE
831 && DECL_SECTION_NAME (decl) != NULL_TREE)
832 return reloc ? unlikely_text_section ()
833 : get_named_section (decl, NULL, 0);
834 else
835 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
836 #else
837 return reloc ? unlikely_text_section () : hot_function_section (decl);
838 #endif
839 }
840
841 section *
842 current_function_section (void)
843 {
844 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
845 if (current_function_decl != NULL_TREE
846 && DECL_SECTION_NAME (current_function_decl) != NULL_TREE)
847 return in_cold_section_p ? unlikely_text_section ()
848 : get_named_section (current_function_decl,
849 NULL, 0);
850 else
851 return targetm.asm_out.select_section (current_function_decl,
852 in_cold_section_p,
853 DECL_ALIGN (current_function_decl));
854 #else
855 return (in_cold_section_p
856 ? unlikely_text_section ()
857 : hot_function_section (current_function_decl));
858 #endif
859 }
860
861 /* Return the read-only data section associated with function DECL. */
862
863 section *
864 default_function_rodata_section (tree decl)
865 {
866 if (decl != NULL_TREE && DECL_SECTION_NAME (decl))
867 {
868 const char *name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
869
870 if (DECL_ONE_ONLY (decl) && HAVE_COMDAT_GROUP)
871 {
872 size_t len = strlen (name) + 3;
873 char* rname = (char *) alloca (len);
874
875 strcpy (rname, ".rodata");
876 strcat (rname, name + 5);
877 return get_section (rname, SECTION_LINKONCE, decl);
878 }
879 /* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo. */
880 else if (DECL_ONE_ONLY (decl)
881 && strncmp (name, ".gnu.linkonce.t.", 16) == 0)
882 {
883 size_t len = strlen (name) + 1;
884 char *rname = (char *) alloca (len);
885
886 memcpy (rname, name, len);
887 rname[14] = 'r';
888 return get_section (rname, SECTION_LINKONCE, decl);
889 }
890 /* For .text.foo we want to use .rodata.foo. */
891 else if (flag_function_sections && flag_data_sections
892 && strncmp (name, ".text.", 6) == 0)
893 {
894 size_t len = strlen (name) + 1;
895 char *rname = (char *) alloca (len + 2);
896
897 memcpy (rname, ".rodata", 7);
898 memcpy (rname + 7, name + 5, len - 5);
899 return get_section (rname, 0, decl);
900 }
901 }
902
903 return readonly_data_section;
904 }
905
906 /* Return the read-only data section associated with function DECL
907 for targets where that section should be always the single
908 readonly data section. */
909
910 section *
911 default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED)
912 {
913 return readonly_data_section;
914 }
915
916 /* Return the section to use for string merging. */
917
918 static section *
919 mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
920 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
921 unsigned int flags ATTRIBUTE_UNUSED)
922 {
923 HOST_WIDE_INT len;
924
925 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
926 && TREE_CODE (decl) == STRING_CST
927 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
928 && align <= 256
929 && (len = int_size_in_bytes (TREE_TYPE (decl))) > 0
930 && TREE_STRING_LENGTH (decl) >= len)
931 {
932 enum machine_mode mode;
933 unsigned int modesize;
934 const char *str;
935 HOST_WIDE_INT i;
936 int j, unit;
937 char name[30];
938
939 mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl)));
940 modesize = GET_MODE_BITSIZE (mode);
941 if (modesize >= 8 && modesize <= 256
942 && (modesize & (modesize - 1)) == 0)
943 {
944 if (align < modesize)
945 align = modesize;
946
947 str = TREE_STRING_POINTER (decl);
948 unit = GET_MODE_SIZE (mode);
949
950 /* Check for embedded NUL characters. */
951 for (i = 0; i < len; i += unit)
952 {
953 for (j = 0; j < unit; j++)
954 if (str[i + j] != '\0')
955 break;
956 if (j == unit)
957 break;
958 }
959 if (i == len - unit)
960 {
961 sprintf (name, ".rodata.str%d.%d", modesize / 8,
962 (int) (align / 8));
963 flags |= (modesize / 8) | SECTION_MERGE | SECTION_STRINGS;
964 return get_section (name, flags, NULL);
965 }
966 }
967 }
968
969 return readonly_data_section;
970 }
971
972 /* Return the section to use for constant merging. */
973
974 section *
975 mergeable_constant_section (enum machine_mode mode ATTRIBUTE_UNUSED,
976 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
977 unsigned int flags ATTRIBUTE_UNUSED)
978 {
979 unsigned int modesize = GET_MODE_BITSIZE (mode);
980
981 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
982 && mode != VOIDmode
983 && mode != BLKmode
984 && modesize <= align
985 && align >= 8
986 && align <= 256
987 && (align & (align - 1)) == 0)
988 {
989 char name[24];
990
991 sprintf (name, ".rodata.cst%d", (int) (align / 8));
992 flags |= (align / 8) | SECTION_MERGE;
993 return get_section (name, flags, NULL);
994 }
995 return readonly_data_section;
996 }
997 \f
998 /* Given NAME, a putative register name, discard any customary prefixes. */
999
1000 static const char *
1001 strip_reg_name (const char *name)
1002 {
1003 #ifdef REGISTER_PREFIX
1004 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
1005 name += strlen (REGISTER_PREFIX);
1006 #endif
1007 if (name[0] == '%' || name[0] == '#')
1008 name++;
1009 return name;
1010 }
1011 \f
1012 /* The user has asked for a DECL to have a particular name. Set (or
1013 change) it in such a way that we don't prefix an underscore to
1014 it. */
1015 void
1016 set_user_assembler_name (tree decl, const char *name)
1017 {
1018 char *starred = (char *) alloca (strlen (name) + 2);
1019 starred[0] = '*';
1020 strcpy (starred + 1, name);
1021 change_decl_assembler_name (decl, get_identifier (starred));
1022 SET_DECL_RTL (decl, NULL_RTX);
1023 }
1024 \f
1025 /* Decode an `asm' spec for a declaration as a register name.
1026 Return the register number, or -1 if nothing specified,
1027 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
1028 or -3 if ASMSPEC is `cc' and is not recognized,
1029 or -4 if ASMSPEC is `memory' and is not recognized.
1030 Accept an exact spelling or a decimal number.
1031 Prefixes such as % are optional. */
1032
1033 int
1034 decode_reg_name (const char *asmspec)
1035 {
1036 if (asmspec != 0)
1037 {
1038 int i;
1039
1040 /* Get rid of confusing prefixes. */
1041 asmspec = strip_reg_name (asmspec);
1042
1043 /* Allow a decimal number as a "register name". */
1044 for (i = strlen (asmspec) - 1; i >= 0; i--)
1045 if (! ISDIGIT (asmspec[i]))
1046 break;
1047 if (asmspec[0] != 0 && i < 0)
1048 {
1049 i = atoi (asmspec);
1050 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
1051 return i;
1052 else
1053 return -2;
1054 }
1055
1056 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1057 if (reg_names[i][0]
1058 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
1059 return i;
1060
1061 #ifdef ADDITIONAL_REGISTER_NAMES
1062 {
1063 static const struct { const char *const name; const int number; } table[]
1064 = ADDITIONAL_REGISTER_NAMES;
1065
1066 for (i = 0; i < (int) ARRAY_SIZE (table); i++)
1067 if (table[i].name[0]
1068 && ! strcmp (asmspec, table[i].name))
1069 return table[i].number;
1070 }
1071 #endif /* ADDITIONAL_REGISTER_NAMES */
1072
1073 if (!strcmp (asmspec, "memory"))
1074 return -4;
1075
1076 if (!strcmp (asmspec, "cc"))
1077 return -3;
1078
1079 return -2;
1080 }
1081
1082 return -1;
1083 }
1084 \f
1085 /* Return true if DECL's initializer is suitable for a BSS section. */
1086
1087 static bool
1088 bss_initializer_p (const_tree decl)
1089 {
1090 return (DECL_INITIAL (decl) == NULL
1091 || DECL_INITIAL (decl) == error_mark_node
1092 || (flag_zero_initialized_in_bss
1093 /* Leave constant zeroes in .rodata so they
1094 can be shared. */
1095 && !TREE_READONLY (decl)
1096 && initializer_zerop (DECL_INITIAL (decl))));
1097 }
1098
1099 /* Compute the alignment of variable specified by DECL.
1100 DONT_OUTPUT_DATA is from assemble_variable. */
1101
1102 void
1103 align_variable (tree decl, bool dont_output_data)
1104 {
1105 unsigned int align = DECL_ALIGN (decl);
1106
1107 /* In the case for initialing an array whose length isn't specified,
1108 where we have not yet been able to do the layout,
1109 figure out the proper alignment now. */
1110 if (dont_output_data && DECL_SIZE (decl) == 0
1111 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
1112 align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
1113
1114 /* Some object file formats have a maximum alignment which they support.
1115 In particular, a.out format supports a maximum alignment of 4. */
1116 if (align > MAX_OFILE_ALIGNMENT)
1117 {
1118 warning (0, "alignment of %q+D is greater than maximum object "
1119 "file alignment. Using %d", decl,
1120 MAX_OFILE_ALIGNMENT/BITS_PER_UNIT);
1121 align = MAX_OFILE_ALIGNMENT;
1122 }
1123
1124 /* On some machines, it is good to increase alignment sometimes. */
1125 if (! DECL_USER_ALIGN (decl))
1126 {
1127 #ifdef DATA_ALIGNMENT
1128 unsigned int data_align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
1129 /* Don't increase alignment too much for TLS variables - TLS space
1130 is too precious. */
1131 if (! DECL_THREAD_LOCAL_P (decl) || data_align <= BITS_PER_WORD)
1132 align = data_align;
1133 #endif
1134 #ifdef CONSTANT_ALIGNMENT
1135 if (DECL_INITIAL (decl) != 0 && DECL_INITIAL (decl) != error_mark_node)
1136 {
1137 unsigned int const_align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl),
1138 align);
1139 /* Don't increase alignment too much for TLS variables - TLS space
1140 is too precious. */
1141 if (! DECL_THREAD_LOCAL_P (decl) || const_align <= BITS_PER_WORD)
1142 align = const_align;
1143 }
1144 #endif
1145 }
1146
1147 /* Reset the alignment in case we have made it tighter, so we can benefit
1148 from it in get_pointer_alignment. */
1149 DECL_ALIGN (decl) = align;
1150 }
1151
1152 /* Return the section into which the given VAR_DECL or CONST_DECL
1153 should be placed. PREFER_NOSWITCH_P is true if a noswitch
1154 section should be used wherever possible. */
1155
1156 static section *
1157 get_variable_section (tree decl, bool prefer_noswitch_p)
1158 {
1159 int reloc;
1160
1161 /* If the decl has been given an explicit section name, then it
1162 isn't common, and shouldn't be handled as such. */
1163 if (DECL_COMMON (decl) && DECL_SECTION_NAME (decl) == NULL)
1164 {
1165 if (DECL_THREAD_LOCAL_P (decl))
1166 return tls_comm_section;
1167 /* This cannot be common bss for an emulated TLS object without
1168 a register_common hook. */
1169 else if (DECL_TLS_MODEL (decl) == TLS_MODEL_EMULATED
1170 && !targetm.emutls.register_common)
1171 ;
1172 else if (TREE_PUBLIC (decl) && bss_initializer_p (decl))
1173 return comm_section;
1174 }
1175
1176 if (DECL_INITIAL (decl) == error_mark_node)
1177 reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;
1178 else if (DECL_INITIAL (decl))
1179 reloc = compute_reloc_for_constant (DECL_INITIAL (decl));
1180 else
1181 reloc = 0;
1182
1183 resolve_unique_section (decl, reloc, flag_data_sections);
1184 if (IN_NAMED_SECTION (decl))
1185 return get_named_section (decl, NULL, reloc);
1186
1187 if (!DECL_THREAD_LOCAL_P (decl)
1188 && !(prefer_noswitch_p && targetm.have_switchable_bss_sections)
1189 && bss_initializer_p (decl))
1190 {
1191 if (!TREE_PUBLIC (decl))
1192 return lcomm_section;
1193 if (bss_noswitch_section)
1194 return bss_noswitch_section;
1195 }
1196
1197 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
1198 }
1199
1200 /* Return the block into which object_block DECL should be placed. */
1201
1202 static struct object_block *
1203 get_block_for_decl (tree decl)
1204 {
1205 section *sect;
1206
1207 if (TREE_CODE (decl) == VAR_DECL)
1208 {
1209 /* The object must be defined in this translation unit. */
1210 if (DECL_EXTERNAL (decl))
1211 return NULL;
1212
1213 /* There's no point using object blocks for something that is
1214 isolated by definition. */
1215 if (DECL_ONE_ONLY (decl))
1216 return NULL;
1217 }
1218
1219 /* We can only calculate block offsets if the decl has a known
1220 constant size. */
1221 if (DECL_SIZE_UNIT (decl) == NULL)
1222 return NULL;
1223 if (!host_integerp (DECL_SIZE_UNIT (decl), 1))
1224 return NULL;
1225
1226 /* Find out which section should contain DECL. We cannot put it into
1227 an object block if it requires a standalone definition. */
1228 if (TREE_CODE (decl) == VAR_DECL)
1229 align_variable (decl, 0);
1230 sect = get_variable_section (decl, true);
1231 if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
1232 return NULL;
1233
1234 return get_block_for_section (sect);
1235 }
1236
1237 /* Make sure block symbol SYMBOL is in block BLOCK. */
1238
1239 static void
1240 change_symbol_block (rtx symbol, struct object_block *block)
1241 {
1242 if (block != SYMBOL_REF_BLOCK (symbol))
1243 {
1244 gcc_assert (SYMBOL_REF_BLOCK_OFFSET (symbol) < 0);
1245 SYMBOL_REF_BLOCK (symbol) = block;
1246 }
1247 }
1248
1249 /* Return true if it is possible to put DECL in an object_block. */
1250
1251 static bool
1252 use_blocks_for_decl_p (tree decl)
1253 {
1254 /* Only data DECLs can be placed into object blocks. */
1255 if (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != CONST_DECL)
1256 return false;
1257
1258 /* Detect decls created by dw2_force_const_mem. Such decls are
1259 special because DECL_INITIAL doesn't specify the decl's true value.
1260 dw2_output_indirect_constants will instead call assemble_variable
1261 with dont_output_data set to 1 and then print the contents itself. */
1262 if (DECL_INITIAL (decl) == decl)
1263 return false;
1264
1265 /* If this decl is an alias, then we don't want to emit a definition. */
1266 if (lookup_attribute ("alias", DECL_ATTRIBUTES (decl)))
1267 return false;
1268
1269 return true;
1270 }
1271
1272 /* Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL should
1273 have static storage duration. In other words, it should not be an
1274 automatic variable, including PARM_DECLs.
1275
1276 There is, however, one exception: this function handles variables
1277 explicitly placed in a particular register by the user.
1278
1279 This is never called for PARM_DECL nodes. */
1280
1281 void
1282 make_decl_rtl (tree decl)
1283 {
1284 const char *name = 0;
1285 int reg_number;
1286 rtx x;
1287
1288 /* Check that we are not being given an automatic variable. */
1289 gcc_assert (TREE_CODE (decl) != PARM_DECL
1290 && TREE_CODE (decl) != RESULT_DECL);
1291
1292 /* A weak alias has TREE_PUBLIC set but not the other bits. */
1293 gcc_assert (TREE_CODE (decl) != VAR_DECL
1294 || TREE_STATIC (decl)
1295 || TREE_PUBLIC (decl)
1296 || DECL_EXTERNAL (decl)
1297 || DECL_REGISTER (decl));
1298
1299 /* And that we were not given a type or a label. */
1300 gcc_assert (TREE_CODE (decl) != TYPE_DECL
1301 && TREE_CODE (decl) != LABEL_DECL);
1302
1303 /* For a duplicate declaration, we can be called twice on the
1304 same DECL node. Don't discard the RTL already made. */
1305 if (DECL_RTL_SET_P (decl))
1306 {
1307 /* If the old RTL had the wrong mode, fix the mode. */
1308 x = DECL_RTL (decl);
1309 if (GET_MODE (x) != DECL_MODE (decl))
1310 SET_DECL_RTL (decl, adjust_address_nv (x, DECL_MODE (decl), 0));
1311
1312 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1313 return;
1314
1315 /* ??? Another way to do this would be to maintain a hashed
1316 table of such critters. Instead of adding stuff to a DECL
1317 to give certain attributes to it, we could use an external
1318 hash map from DECL to set of attributes. */
1319
1320 /* Let the target reassign the RTL if it wants.
1321 This is necessary, for example, when one machine specific
1322 decl attribute overrides another. */
1323 targetm.encode_section_info (decl, DECL_RTL (decl), false);
1324
1325 /* If the symbol has a SYMBOL_REF_BLOCK field, update it based
1326 on the new decl information. */
1327 if (MEM_P (x)
1328 && GET_CODE (XEXP (x, 0)) == SYMBOL_REF
1329 && SYMBOL_REF_HAS_BLOCK_INFO_P (XEXP (x, 0)))
1330 change_symbol_block (XEXP (x, 0), get_block_for_decl (decl));
1331
1332 /* Make this function static known to the mudflap runtime. */
1333 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
1334 mudflap_enqueue_decl (decl);
1335
1336 return;
1337 }
1338
1339 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
1340
1341 if (name[0] != '*' && TREE_CODE (decl) != FUNCTION_DECL
1342 && DECL_REGISTER (decl))
1343 {
1344 error ("register name not specified for %q+D", decl);
1345 }
1346 else if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1347 {
1348 const char *asmspec = name+1;
1349 reg_number = decode_reg_name (asmspec);
1350 /* First detect errors in declaring global registers. */
1351 if (reg_number == -1)
1352 error ("register name not specified for %q+D", decl);
1353 else if (reg_number < 0)
1354 error ("invalid register name for %q+D", decl);
1355 else if (TYPE_MODE (TREE_TYPE (decl)) == BLKmode)
1356 error ("data type of %q+D isn%'t suitable for a register",
1357 decl);
1358 else if (! HARD_REGNO_MODE_OK (reg_number, TYPE_MODE (TREE_TYPE (decl))))
1359 error ("register specified for %q+D isn%'t suitable for data type",
1360 decl);
1361 /* Now handle properly declared static register variables. */
1362 else
1363 {
1364 int nregs;
1365
1366 if (DECL_INITIAL (decl) != 0 && TREE_STATIC (decl))
1367 {
1368 DECL_INITIAL (decl) = 0;
1369 error ("global register variable has initial value");
1370 }
1371 if (TREE_THIS_VOLATILE (decl))
1372 warning (OPT_Wvolatile_register_var,
1373 "optimization may eliminate reads and/or "
1374 "writes to register variables");
1375
1376 /* If the user specified one of the eliminables registers here,
1377 e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
1378 confused with that register and be eliminated. This usage is
1379 somewhat suspect... */
1380
1381 SET_DECL_RTL (decl, gen_rtx_raw_REG (DECL_MODE (decl), reg_number));
1382 ORIGINAL_REGNO (DECL_RTL (decl)) = reg_number;
1383 REG_USERVAR_P (DECL_RTL (decl)) = 1;
1384
1385 if (TREE_STATIC (decl))
1386 {
1387 /* Make this register global, so not usable for anything
1388 else. */
1389 #ifdef ASM_DECLARE_REGISTER_GLOBAL
1390 name = IDENTIFIER_POINTER (DECL_NAME (decl));
1391 ASM_DECLARE_REGISTER_GLOBAL (asm_out_file, decl, reg_number, name);
1392 #endif
1393 nregs = hard_regno_nregs[reg_number][DECL_MODE (decl)];
1394 while (nregs > 0)
1395 globalize_reg (reg_number + --nregs);
1396 }
1397
1398 /* As a register variable, it has no section. */
1399 return;
1400 }
1401 }
1402 /* Now handle ordinary static variables and functions (in memory).
1403 Also handle vars declared register invalidly. */
1404 else if (name[0] == '*')
1405 {
1406 #ifdef REGISTER_PREFIX
1407 if (strlen (REGISTER_PREFIX) != 0)
1408 {
1409 reg_number = decode_reg_name (name);
1410 if (reg_number >= 0 || reg_number == -3)
1411 error ("register name given for non-register variable %q+D", decl);
1412 }
1413 #endif
1414 }
1415
1416 /* Specifying a section attribute on a variable forces it into a
1417 non-.bss section, and thus it cannot be common. */
1418 if (TREE_CODE (decl) == VAR_DECL
1419 && DECL_SECTION_NAME (decl) != NULL_TREE
1420 && DECL_INITIAL (decl) == NULL_TREE
1421 && DECL_COMMON (decl))
1422 DECL_COMMON (decl) = 0;
1423
1424 /* Variables can't be both common and weak. */
1425 if (TREE_CODE (decl) == VAR_DECL && DECL_WEAK (decl))
1426 DECL_COMMON (decl) = 0;
1427
1428 if (use_object_blocks_p () && use_blocks_for_decl_p (decl))
1429 x = create_block_symbol (name, get_block_for_decl (decl), -1);
1430 else
1431 x = gen_rtx_SYMBOL_REF (Pmode, name);
1432 SYMBOL_REF_WEAK (x) = DECL_WEAK (decl);
1433 SET_SYMBOL_REF_DECL (x, decl);
1434
1435 x = gen_rtx_MEM (DECL_MODE (decl), x);
1436 if (TREE_CODE (decl) != FUNCTION_DECL)
1437 set_mem_attributes (x, decl, 1);
1438 SET_DECL_RTL (decl, x);
1439
1440 /* Optionally set flags or add text to the name to record information
1441 such as that it is a function name.
1442 If the name is changed, the macro ASM_OUTPUT_LABELREF
1443 will have to know how to strip this information. */
1444 targetm.encode_section_info (decl, DECL_RTL (decl), true);
1445
1446 /* Make this function static known to the mudflap runtime. */
1447 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
1448 mudflap_enqueue_decl (decl);
1449 }
1450 \f
1451 /* Output a string of literal assembler code
1452 for an `asm' keyword used between functions. */
1453
1454 void
1455 assemble_asm (tree string)
1456 {
1457 app_enable ();
1458
1459 if (TREE_CODE (string) == ADDR_EXPR)
1460 string = TREE_OPERAND (string, 0);
1461
1462 fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string));
1463 }
1464
1465 /* Record an element in the table of global destructors. SYMBOL is
1466 a SYMBOL_REF of the function to be called; PRIORITY is a number
1467 between 0 and MAX_INIT_PRIORITY. */
1468
1469 void
1470 default_stabs_asm_out_destructor (rtx symbol ATTRIBUTE_UNUSED,
1471 int priority ATTRIBUTE_UNUSED)
1472 {
1473 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1474 /* Tell GNU LD that this is part of the static destructor set.
1475 This will work for any system that uses stabs, most usefully
1476 aout systems. */
1477 dbxout_begin_simple_stabs ("___DTOR_LIST__", 22 /* N_SETT */);
1478 dbxout_stab_value_label (XSTR (symbol, 0));
1479 #else
1480 sorry ("global destructors not supported on this target");
1481 #endif
1482 }
1483
1484 /* Write the address of the entity given by SYMBOL to SEC. */
1485 void
1486 assemble_addr_to_section (rtx symbol, section *sec)
1487 {
1488 switch_to_section (sec);
1489 assemble_align (POINTER_SIZE);
1490 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1491 }
1492
1493 /* Return the numbered .ctors.N (if CONSTRUCTOR_P) or .dtors.N (if
1494 not) section for PRIORITY. */
1495 section *
1496 get_cdtor_priority_section (int priority, bool constructor_p)
1497 {
1498 char buf[16];
1499
1500 /* ??? This only works reliably with the GNU linker. */
1501 sprintf (buf, "%s.%.5u",
1502 constructor_p ? ".ctors" : ".dtors",
1503 /* Invert the numbering so the linker puts us in the proper
1504 order; constructors are run from right to left, and the
1505 linker sorts in increasing order. */
1506 MAX_INIT_PRIORITY - priority);
1507 return get_section (buf, SECTION_WRITE, NULL);
1508 }
1509
1510 void
1511 default_named_section_asm_out_destructor (rtx symbol, int priority)
1512 {
1513 section *sec;
1514
1515 if (priority != DEFAULT_INIT_PRIORITY)
1516 sec = get_cdtor_priority_section (priority,
1517 /*constructor_p=*/false);
1518 else
1519 sec = get_section (".dtors", SECTION_WRITE, NULL);
1520
1521 assemble_addr_to_section (symbol, sec);
1522 }
1523
1524 #ifdef DTORS_SECTION_ASM_OP
1525 void
1526 default_dtor_section_asm_out_destructor (rtx symbol,
1527 int priority ATTRIBUTE_UNUSED)
1528 {
1529 assemble_addr_to_section (symbol, dtors_section);
1530 }
1531 #endif
1532
1533 /* Likewise for global constructors. */
1534
1535 void
1536 default_stabs_asm_out_constructor (rtx symbol ATTRIBUTE_UNUSED,
1537 int priority ATTRIBUTE_UNUSED)
1538 {
1539 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1540 /* Tell GNU LD that this is part of the static destructor set.
1541 This will work for any system that uses stabs, most usefully
1542 aout systems. */
1543 dbxout_begin_simple_stabs ("___CTOR_LIST__", 22 /* N_SETT */);
1544 dbxout_stab_value_label (XSTR (symbol, 0));
1545 #else
1546 sorry ("global constructors not supported on this target");
1547 #endif
1548 }
1549
1550 void
1551 default_named_section_asm_out_constructor (rtx symbol, int priority)
1552 {
1553 section *sec;
1554
1555 if (priority != DEFAULT_INIT_PRIORITY)
1556 sec = get_cdtor_priority_section (priority,
1557 /*constructor_p=*/true);
1558 else
1559 sec = get_section (".ctors", SECTION_WRITE, NULL);
1560
1561 assemble_addr_to_section (symbol, sec);
1562 }
1563
1564 #ifdef CTORS_SECTION_ASM_OP
1565 void
1566 default_ctor_section_asm_out_constructor (rtx symbol,
1567 int priority ATTRIBUTE_UNUSED)
1568 {
1569 assemble_addr_to_section (symbol, ctors_section);
1570 }
1571 #endif
1572 \f
1573 /* CONSTANT_POOL_BEFORE_FUNCTION may be defined as an expression with
1574 a nonzero value if the constant pool should be output before the
1575 start of the function, or a zero value if the pool should output
1576 after the end of the function. The default is to put it before the
1577 start. */
1578
1579 #ifndef CONSTANT_POOL_BEFORE_FUNCTION
1580 #define CONSTANT_POOL_BEFORE_FUNCTION 1
1581 #endif
1582
1583 /* DECL is an object (either VAR_DECL or FUNCTION_DECL) which is going
1584 to be output to assembler.
1585 Set first_global_object_name and weak_global_object_name as appropriate. */
1586
1587 void
1588 notice_global_symbol (tree decl)
1589 {
1590 const char **type = &first_global_object_name;
1591
1592 if (first_global_object_name
1593 || !TREE_PUBLIC (decl)
1594 || DECL_EXTERNAL (decl)
1595 || !DECL_NAME (decl)
1596 || (TREE_CODE (decl) != FUNCTION_DECL
1597 && (TREE_CODE (decl) != VAR_DECL
1598 || (DECL_COMMON (decl)
1599 && (DECL_INITIAL (decl) == 0
1600 || DECL_INITIAL (decl) == error_mark_node))))
1601 || !MEM_P (DECL_RTL (decl)))
1602 return;
1603
1604 /* We win when global object is found, but it is useful to know about weak
1605 symbol as well so we can produce nicer unique names. */
1606 if (DECL_WEAK (decl) || DECL_ONE_ONLY (decl) || flag_shlib)
1607 type = &weak_global_object_name;
1608
1609 if (!*type)
1610 {
1611 const char *p;
1612 const char *name;
1613 rtx decl_rtl = DECL_RTL (decl);
1614
1615 p = targetm.strip_name_encoding (XSTR (XEXP (decl_rtl, 0), 0));
1616 name = ggc_strdup (p);
1617
1618 *type = name;
1619 }
1620 }
1621
1622 /* Output assembler code for the constant pool of a function and associated
1623 with defining the name of the function. DECL describes the function.
1624 NAME is the function's name. For the constant pool, we use the current
1625 constant pool data. */
1626
1627 void
1628 assemble_start_function (tree decl, const char *fnname)
1629 {
1630 int align;
1631 char tmp_label[100];
1632 bool hot_label_written = false;
1633
1634 crtl->subsections.unlikely_text_section_name = NULL;
1635
1636 first_function_block_is_cold = false;
1637 if (flag_reorder_blocks_and_partition)
1638 {
1639 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTB", const_labelno);
1640 crtl->subsections.hot_section_label = ggc_strdup (tmp_label);
1641 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDB", const_labelno);
1642 crtl->subsections.cold_section_label = ggc_strdup (tmp_label);
1643 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTE", const_labelno);
1644 crtl->subsections.hot_section_end_label = ggc_strdup (tmp_label);
1645 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDE", const_labelno);
1646 crtl->subsections.cold_section_end_label = ggc_strdup (tmp_label);
1647 const_labelno++;
1648 }
1649 else
1650 {
1651 crtl->subsections.hot_section_label = NULL;
1652 crtl->subsections.cold_section_label = NULL;
1653 crtl->subsections.hot_section_end_label = NULL;
1654 crtl->subsections.cold_section_end_label = NULL;
1655 }
1656
1657 /* The following code does not need preprocessing in the assembler. */
1658
1659 app_disable ();
1660
1661 if (CONSTANT_POOL_BEFORE_FUNCTION)
1662 output_constant_pool (fnname, decl);
1663
1664 resolve_unique_section (decl, 0, flag_function_sections);
1665
1666 /* Make sure the not and cold text (code) sections are properly
1667 aligned. This is necessary here in the case where the function
1668 has both hot and cold sections, because we don't want to re-set
1669 the alignment when the section switch happens mid-function. */
1670
1671 if (flag_reorder_blocks_and_partition)
1672 {
1673 switch_to_section (unlikely_text_section ());
1674 assemble_align (DECL_ALIGN (decl));
1675 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.cold_section_label);
1676
1677 /* When the function starts with a cold section, we need to explicitly
1678 align the hot section and write out the hot section label.
1679 But if the current function is a thunk, we do not have a CFG. */
1680 if (!crtl->is_thunk
1681 && BB_PARTITION (ENTRY_BLOCK_PTR->next_bb) == BB_COLD_PARTITION)
1682 {
1683 switch_to_section (text_section);
1684 assemble_align (DECL_ALIGN (decl));
1685 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_label);
1686 hot_label_written = true;
1687 first_function_block_is_cold = true;
1688 }
1689 }
1690 else if (DECL_SECTION_NAME (decl))
1691 {
1692 /* Calls to function_section rely on first_function_block_is_cold
1693 being accurate. The first block may be cold even if we aren't
1694 doing partitioning, if the entire function was decided by
1695 choose_function_section (predict.c) to be cold. */
1696
1697 initialize_cold_section_name ();
1698
1699 if (crtl->subsections.unlikely_text_section_name
1700 && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
1701 crtl->subsections.unlikely_text_section_name) == 0)
1702 first_function_block_is_cold = true;
1703 }
1704
1705 in_cold_section_p = first_function_block_is_cold;
1706
1707 /* Switch to the correct text section for the start of the function. */
1708
1709 switch_to_section (function_section (decl));
1710 if (flag_reorder_blocks_and_partition
1711 && !hot_label_written)
1712 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_label);
1713
1714 /* Tell assembler to move to target machine's alignment for functions. */
1715 align = floor_log2 (DECL_ALIGN (decl) / BITS_PER_UNIT);
1716 if (align > 0)
1717 {
1718 ASM_OUTPUT_ALIGN (asm_out_file, align);
1719 }
1720
1721 /* Handle a user-specified function alignment.
1722 Note that we still need to align to DECL_ALIGN, as above,
1723 because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */
1724 if (! DECL_USER_ALIGN (decl)
1725 && align_functions_log > align
1726 && optimize_function_for_speed_p (cfun))
1727 {
1728 #ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
1729 ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file,
1730 align_functions_log, align_functions - 1);
1731 #else
1732 ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log);
1733 #endif
1734 }
1735
1736 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
1737 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
1738 #endif
1739
1740 (*debug_hooks->begin_function) (decl);
1741
1742 /* Make function name accessible from other files, if appropriate. */
1743
1744 if (TREE_PUBLIC (decl))
1745 {
1746 notice_global_symbol (decl);
1747
1748 globalize_decl (decl);
1749
1750 maybe_assemble_visibility (decl);
1751 }
1752
1753 if (DECL_PRESERVE_P (decl))
1754 targetm.asm_out.mark_decl_preserved (fnname);
1755
1756 /* Do any machine/system dependent processing of the function name. */
1757 #ifdef ASM_DECLARE_FUNCTION_NAME
1758 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
1759 #else
1760 /* Standard thing is just output label for the function. */
1761 ASM_OUTPUT_LABEL (asm_out_file, fnname);
1762 #endif /* ASM_DECLARE_FUNCTION_NAME */
1763 }
1764
1765 /* Output assembler code associated with defining the size of the
1766 function. DECL describes the function. NAME is the function's name. */
1767
1768 void
1769 assemble_end_function (tree decl, const char *fnname ATTRIBUTE_UNUSED)
1770 {
1771 #ifdef ASM_DECLARE_FUNCTION_SIZE
1772 /* We could have switched section in the middle of the function. */
1773 if (flag_reorder_blocks_and_partition)
1774 switch_to_section (function_section (decl));
1775 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
1776 #endif
1777 if (! CONSTANT_POOL_BEFORE_FUNCTION)
1778 {
1779 output_constant_pool (fnname, decl);
1780 switch_to_section (function_section (decl)); /* need to switch back */
1781 }
1782 /* Output labels for end of hot/cold text sections (to be used by
1783 debug info.) */
1784 if (flag_reorder_blocks_and_partition)
1785 {
1786 section *save_text_section;
1787
1788 save_text_section = in_section;
1789 switch_to_section (unlikely_text_section ());
1790 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.cold_section_end_label);
1791 if (first_function_block_is_cold)
1792 switch_to_section (text_section);
1793 else
1794 switch_to_section (function_section (decl));
1795 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_end_label);
1796 switch_to_section (save_text_section);
1797 }
1798 }
1799 \f
1800 /* Assemble code to leave SIZE bytes of zeros. */
1801
1802 void
1803 assemble_zeros (unsigned HOST_WIDE_INT size)
1804 {
1805 /* Do no output if -fsyntax-only. */
1806 if (flag_syntax_only)
1807 return;
1808
1809 #ifdef ASM_NO_SKIP_IN_TEXT
1810 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
1811 so we must output 0s explicitly in the text section. */
1812 if (ASM_NO_SKIP_IN_TEXT && (in_section->common.flags & SECTION_CODE) != 0)
1813 {
1814 unsigned HOST_WIDE_INT i;
1815 for (i = 0; i < size; i++)
1816 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1);
1817 }
1818 else
1819 #endif
1820 if (size > 0)
1821 ASM_OUTPUT_SKIP (asm_out_file, size);
1822 }
1823
1824 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
1825
1826 void
1827 assemble_align (int align)
1828 {
1829 if (align > BITS_PER_UNIT)
1830 {
1831 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1832 }
1833 }
1834
1835 /* Assemble a string constant with the specified C string as contents. */
1836
1837 void
1838 assemble_string (const char *p, int size)
1839 {
1840 int pos = 0;
1841 int maximum = 2000;
1842
1843 /* If the string is very long, split it up. */
1844
1845 while (pos < size)
1846 {
1847 int thissize = size - pos;
1848 if (thissize > maximum)
1849 thissize = maximum;
1850
1851 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
1852
1853 pos += thissize;
1854 p += thissize;
1855 }
1856 }
1857
1858 \f
1859 /* A noswitch_section_callback for lcomm_section. */
1860
1861 static bool
1862 emit_local (tree decl ATTRIBUTE_UNUSED,
1863 const char *name ATTRIBUTE_UNUSED,
1864 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1865 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1866 {
1867 #if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL
1868 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name,
1869 size, DECL_ALIGN (decl));
1870 return true;
1871 #elif defined ASM_OUTPUT_ALIGNED_LOCAL
1872 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl));
1873 return true;
1874 #else
1875 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1876 return false;
1877 #endif
1878 }
1879
1880 /* A noswitch_section_callback for bss_noswitch_section. */
1881
1882 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
1883 static bool
1884 emit_bss (tree decl ATTRIBUTE_UNUSED,
1885 const char *name ATTRIBUTE_UNUSED,
1886 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1887 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1888 {
1889 #if defined ASM_OUTPUT_ALIGNED_BSS
1890 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl));
1891 return true;
1892 #else
1893 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded);
1894 return false;
1895 #endif
1896 }
1897 #endif
1898
1899 /* A noswitch_section_callback for comm_section. */
1900
1901 static bool
1902 emit_common (tree decl ATTRIBUTE_UNUSED,
1903 const char *name ATTRIBUTE_UNUSED,
1904 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1905 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1906 {
1907 #if defined ASM_OUTPUT_ALIGNED_DECL_COMMON
1908 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name,
1909 size, DECL_ALIGN (decl));
1910 return true;
1911 #elif defined ASM_OUTPUT_ALIGNED_COMMON
1912 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl));
1913 return true;
1914 #else
1915 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded);
1916 return false;
1917 #endif
1918 }
1919
1920 /* A noswitch_section_callback for tls_comm_section. */
1921
1922 static bool
1923 emit_tls_common (tree decl ATTRIBUTE_UNUSED,
1924 const char *name ATTRIBUTE_UNUSED,
1925 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1926 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1927 {
1928 #ifdef ASM_OUTPUT_TLS_COMMON
1929 ASM_OUTPUT_TLS_COMMON (asm_out_file, decl, name, size);
1930 return true;
1931 #else
1932 sorry ("thread-local COMMON data not implemented");
1933 return true;
1934 #endif
1935 }
1936
1937 /* Assemble DECL given that it belongs in SECTION_NOSWITCH section SECT.
1938 NAME is the name of DECL's SYMBOL_REF. */
1939
1940 static void
1941 assemble_noswitch_variable (tree decl, const char *name, section *sect)
1942 {
1943 unsigned HOST_WIDE_INT size, rounded;
1944
1945 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
1946 rounded = size;
1947
1948 /* Don't allocate zero bytes of common,
1949 since that means "undefined external" in the linker. */
1950 if (size == 0)
1951 rounded = 1;
1952
1953 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1954 so that each uninitialized object starts on such a boundary. */
1955 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
1956 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1957 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1958
1959 if (!sect->noswitch.callback (decl, name, size, rounded)
1960 && (unsigned HOST_WIDE_INT) DECL_ALIGN_UNIT (decl) > rounded)
1961 warning (0, "requested alignment for %q+D is greater than "
1962 "implemented alignment of %wu", decl, rounded);
1963 }
1964
1965 /* A subroutine of assemble_variable. Output the label and contents of
1966 DECL, whose address is a SYMBOL_REF with name NAME. DONT_OUTPUT_DATA
1967 is as for assemble_variable. */
1968
1969 static void
1970 assemble_variable_contents (tree decl, const char *name,
1971 bool dont_output_data)
1972 {
1973 /* Do any machine/system dependent processing of the object. */
1974 #ifdef ASM_DECLARE_OBJECT_NAME
1975 last_assemble_variable_decl = decl;
1976 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
1977 #else
1978 /* Standard thing is just output label for the object. */
1979 ASM_OUTPUT_LABEL (asm_out_file, name);
1980 #endif /* ASM_DECLARE_OBJECT_NAME */
1981
1982 if (!dont_output_data)
1983 {
1984 if (DECL_INITIAL (decl)
1985 && DECL_INITIAL (decl) != error_mark_node
1986 && !initializer_zerop (DECL_INITIAL (decl)))
1987 /* Output the actual data. */
1988 output_constant (DECL_INITIAL (decl),
1989 tree_low_cst (DECL_SIZE_UNIT (decl), 1),
1990 DECL_ALIGN (decl));
1991 else
1992 /* Leave space for it. */
1993 assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1));
1994 }
1995 }
1996
1997 /* Initialize emulated tls object TO, which refers to TLS variable
1998 DECL and is initialized by PROXY. */
1999
2000 tree
2001 default_emutls_var_init (tree to, tree decl, tree proxy)
2002 {
2003 VEC(constructor_elt,gc) *v = VEC_alloc (constructor_elt, gc, 4);
2004 constructor_elt *elt;
2005 tree type = TREE_TYPE (to);
2006 tree field = TYPE_FIELDS (type);
2007
2008 elt = VEC_quick_push (constructor_elt, v, NULL);
2009 elt->index = field;
2010 elt->value = fold_convert (TREE_TYPE (field), DECL_SIZE_UNIT (decl));
2011
2012 elt = VEC_quick_push (constructor_elt, v, NULL);
2013 field = TREE_CHAIN (field);
2014 elt->index = field;
2015 elt->value = build_int_cst (TREE_TYPE (field),
2016 DECL_ALIGN_UNIT (decl));
2017
2018 elt = VEC_quick_push (constructor_elt, v, NULL);
2019 field = TREE_CHAIN (field);
2020 elt->index = field;
2021 elt->value = null_pointer_node;
2022
2023 elt = VEC_quick_push (constructor_elt, v, NULL);
2024 field = TREE_CHAIN (field);
2025 elt->index = field;
2026 elt->value = proxy;
2027
2028 return build_constructor (type, v);
2029 }
2030
2031 /* Assemble everything that is needed for a variable or function declaration.
2032 Not used for automatic variables, and not used for function definitions.
2033 Should not be called for variables of incomplete structure type.
2034
2035 TOP_LEVEL is nonzero if this variable has file scope.
2036 AT_END is nonzero if this is the special handling, at end of compilation,
2037 to define things that have had only tentative definitions.
2038 DONT_OUTPUT_DATA if nonzero means don't actually output the
2039 initial value (that will be done by the caller). */
2040
2041 void
2042 assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED,
2043 int at_end ATTRIBUTE_UNUSED, int dont_output_data)
2044 {
2045 const char *name;
2046 rtx decl_rtl, symbol;
2047 section *sect;
2048
2049 if (! targetm.have_tls
2050 && TREE_CODE (decl) == VAR_DECL
2051 && DECL_THREAD_LOCAL_P (decl))
2052 {
2053 tree to = emutls_decl (decl);
2054
2055 /* If this variable is defined locally, then we need to initialize the
2056 control structure with size and alignment information. We do this
2057 at the last moment because tentative definitions can take a locally
2058 defined but uninitialized variable and initialize it later, which
2059 would result in incorrect contents. */
2060 if (! DECL_EXTERNAL (to)
2061 && (! DECL_COMMON (to)
2062 || (DECL_INITIAL (decl)
2063 && DECL_INITIAL (decl) != error_mark_node)))
2064 {
2065 DECL_INITIAL (to) = targetm.emutls.var_init
2066 (to, decl, get_emutls_init_templ_addr (decl));
2067
2068 /* Make sure the template is marked as needed early enough.
2069 Without this, if the variable is placed in a
2070 section-anchored block, the template will only be marked
2071 when it's too late. */
2072 record_references_in_initializer (to);
2073 }
2074
2075 decl = to;
2076 }
2077
2078 last_assemble_variable_decl = 0;
2079
2080 /* Normally no need to say anything here for external references,
2081 since assemble_external is called by the language-specific code
2082 when a declaration is first seen. */
2083
2084 if (DECL_EXTERNAL (decl))
2085 return;
2086
2087 /* Output no assembler code for a function declaration.
2088 Only definitions of functions output anything. */
2089
2090 if (TREE_CODE (decl) == FUNCTION_DECL)
2091 return;
2092
2093 /* Do nothing for global register variables. */
2094 if (DECL_RTL_SET_P (decl) && REG_P (DECL_RTL (decl)))
2095 {
2096 TREE_ASM_WRITTEN (decl) = 1;
2097 return;
2098 }
2099
2100 /* If type was incomplete when the variable was declared,
2101 see if it is complete now. */
2102
2103 if (DECL_SIZE (decl) == 0)
2104 layout_decl (decl, 0);
2105
2106 /* Still incomplete => don't allocate it; treat the tentative defn
2107 (which is what it must have been) as an `extern' reference. */
2108
2109 if (!dont_output_data && DECL_SIZE (decl) == 0)
2110 {
2111 error ("storage size of %q+D isn%'t known", decl);
2112 TREE_ASM_WRITTEN (decl) = 1;
2113 return;
2114 }
2115
2116 /* The first declaration of a variable that comes through this function
2117 decides whether it is global (in C, has external linkage)
2118 or local (in C, has internal linkage). So do nothing more
2119 if this function has already run. */
2120
2121 if (TREE_ASM_WRITTEN (decl))
2122 return;
2123
2124 /* Make sure targetm.encode_section_info is invoked before we set
2125 ASM_WRITTEN. */
2126 decl_rtl = DECL_RTL (decl);
2127
2128 TREE_ASM_WRITTEN (decl) = 1;
2129
2130 /* Do no output if -fsyntax-only. */
2131 if (flag_syntax_only)
2132 return;
2133
2134 app_disable ();
2135
2136 if (! dont_output_data
2137 && ! host_integerp (DECL_SIZE_UNIT (decl), 1))
2138 {
2139 error ("size of variable %q+D is too large", decl);
2140 return;
2141 }
2142
2143 gcc_assert (MEM_P (decl_rtl));
2144 gcc_assert (GET_CODE (XEXP (decl_rtl, 0)) == SYMBOL_REF);
2145 symbol = XEXP (decl_rtl, 0);
2146 name = XSTR (symbol, 0);
2147 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
2148 notice_global_symbol (decl);
2149
2150 /* Compute the alignment of this data. */
2151
2152 align_variable (decl, dont_output_data);
2153 set_mem_align (decl_rtl, DECL_ALIGN (decl));
2154
2155 if (TREE_PUBLIC (decl))
2156 maybe_assemble_visibility (decl);
2157
2158 if (DECL_PRESERVE_P (decl))
2159 targetm.asm_out.mark_decl_preserved (name);
2160
2161 /* First make the assembler name(s) global if appropriate. */
2162 sect = get_variable_section (decl, false);
2163 if (TREE_PUBLIC (decl)
2164 && DECL_NAME (decl)
2165 && (sect->common.flags & SECTION_COMMON) == 0)
2166 globalize_decl (decl);
2167
2168 /* Output any data that we will need to use the address of. */
2169 if (DECL_INITIAL (decl) && DECL_INITIAL (decl) != error_mark_node)
2170 output_addressed_constants (DECL_INITIAL (decl));
2171
2172 /* dbxout.c needs to know this. */
2173 if (sect && (sect->common.flags & SECTION_CODE) != 0)
2174 DECL_IN_TEXT_SECTION (decl) = 1;
2175
2176 /* If the decl is part of an object_block, make sure that the decl
2177 has been positioned within its block, but do not write out its
2178 definition yet. output_object_blocks will do that later. */
2179 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
2180 {
2181 gcc_assert (!dont_output_data);
2182 place_block_symbol (symbol);
2183 }
2184 else if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
2185 assemble_noswitch_variable (decl, name, sect);
2186 else
2187 {
2188 switch_to_section (sect);
2189 if (DECL_ALIGN (decl) > BITS_PER_UNIT)
2190 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (DECL_ALIGN_UNIT (decl)));
2191 assemble_variable_contents (decl, name, dont_output_data);
2192 }
2193 }
2194
2195 /* Return 1 if type TYPE contains any pointers. */
2196
2197 static int
2198 contains_pointers_p (tree type)
2199 {
2200 switch (TREE_CODE (type))
2201 {
2202 case POINTER_TYPE:
2203 case REFERENCE_TYPE:
2204 /* I'm not sure whether OFFSET_TYPE needs this treatment,
2205 so I'll play safe and return 1. */
2206 case OFFSET_TYPE:
2207 return 1;
2208
2209 case RECORD_TYPE:
2210 case UNION_TYPE:
2211 case QUAL_UNION_TYPE:
2212 {
2213 tree fields;
2214 /* For a type that has fields, see if the fields have pointers. */
2215 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2216 if (TREE_CODE (fields) == FIELD_DECL
2217 && contains_pointers_p (TREE_TYPE (fields)))
2218 return 1;
2219 return 0;
2220 }
2221
2222 case ARRAY_TYPE:
2223 /* An array type contains pointers if its element type does. */
2224 return contains_pointers_p (TREE_TYPE (type));
2225
2226 default:
2227 return 0;
2228 }
2229 }
2230
2231 /* We delay assemble_external processing until
2232 the compilation unit is finalized. This is the best we can do for
2233 right now (i.e. stage 3 of GCC 4.0) - the right thing is to delay
2234 it all the way to final. See PR 17982 for further discussion. */
2235 static GTY(()) tree pending_assemble_externals;
2236
2237 #ifdef ASM_OUTPUT_EXTERNAL
2238 /* True if DECL is a function decl for which no out-of-line copy exists.
2239 It is assumed that DECL's assembler name has been set. */
2240
2241 static bool
2242 incorporeal_function_p (tree decl)
2243 {
2244 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
2245 {
2246 const char *name;
2247
2248 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
2249 && DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA)
2250 return true;
2251
2252 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
2253 if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
2254 return true;
2255 }
2256 return false;
2257 }
2258
2259 /* Actually do the tests to determine if this is necessary, and invoke
2260 ASM_OUTPUT_EXTERNAL. */
2261 static void
2262 assemble_external_real (tree decl)
2263 {
2264 rtx rtl = DECL_RTL (decl);
2265
2266 if (MEM_P (rtl) && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
2267 && !SYMBOL_REF_USED (XEXP (rtl, 0))
2268 && !incorporeal_function_p (decl))
2269 {
2270 /* Some systems do require some output. */
2271 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
2272 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
2273 }
2274 }
2275 #endif
2276
2277 void
2278 process_pending_assemble_externals (void)
2279 {
2280 #ifdef ASM_OUTPUT_EXTERNAL
2281 tree list;
2282 for (list = pending_assemble_externals; list; list = TREE_CHAIN (list))
2283 assemble_external_real (TREE_VALUE (list));
2284
2285 pending_assemble_externals = 0;
2286 #endif
2287 }
2288
2289 /* This TREE_LIST contains any weak symbol declarations waiting
2290 to be emitted. */
2291 static GTY(()) tree weak_decls;
2292
2293 /* Output something to declare an external symbol to the assembler,
2294 and qualifiers such as weakness. (Most assemblers don't need
2295 extern declaration, so we normally output nothing.) Do nothing if
2296 DECL is not external. */
2297
2298 void
2299 assemble_external (tree decl ATTRIBUTE_UNUSED)
2300 {
2301 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the
2302 main body of this code is only rarely exercised. To provide some
2303 testing, on all platforms, we make sure that the ASM_OUT_FILE is
2304 open. If it's not, we should not be calling this function. */
2305 gcc_assert (asm_out_file);
2306
2307 if (!DECL_P (decl) || !DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl))
2308 return;
2309
2310 /* We want to output annotation for weak and external symbols at
2311 very last to check if they are references or not. */
2312
2313 if (SUPPORTS_WEAK && DECL_WEAK (decl)
2314 /* TREE_STATIC is a weird and abused creature which is not
2315 generally the right test for whether an entity has been
2316 locally emitted, inlined or otherwise not-really-extern, but
2317 for declarations that can be weak, it happens to be
2318 match. */
2319 && !TREE_STATIC (decl))
2320 weak_decls = tree_cons (NULL, decl, weak_decls);
2321
2322 #ifdef ASM_OUTPUT_EXTERNAL
2323 pending_assemble_externals = tree_cons (0, decl,
2324 pending_assemble_externals);
2325 #endif
2326 }
2327
2328 /* Similar, for calling a library function FUN. */
2329
2330 void
2331 assemble_external_libcall (rtx fun)
2332 {
2333 /* Declare library function name external when first used, if nec. */
2334 if (! SYMBOL_REF_USED (fun))
2335 {
2336 SYMBOL_REF_USED (fun) = 1;
2337 targetm.asm_out.external_libcall (fun);
2338 }
2339 }
2340
2341 /* Assemble a label named NAME. */
2342
2343 void
2344 assemble_label (const char *name)
2345 {
2346 ASM_OUTPUT_LABEL (asm_out_file, name);
2347 }
2348
2349 /* Set the symbol_referenced flag for ID. */
2350 void
2351 mark_referenced (tree id)
2352 {
2353 TREE_SYMBOL_REFERENCED (id) = 1;
2354 }
2355
2356 /* Set the symbol_referenced flag for DECL and notify callgraph. */
2357 void
2358 mark_decl_referenced (tree decl)
2359 {
2360 if (TREE_CODE (decl) == FUNCTION_DECL)
2361 {
2362 /* Extern inline functions don't become needed when referenced.
2363 If we know a method will be emitted in other TU and no new
2364 functions can be marked reachable, just use the external
2365 definition. */
2366 struct cgraph_node *node = cgraph_node (decl);
2367 if (!DECL_EXTERNAL (decl)
2368 && (!node->local.vtable_method || !cgraph_global_info_ready
2369 || !node->local.finalized))
2370 cgraph_mark_needed_node (node);
2371 }
2372 else if (TREE_CODE (decl) == VAR_DECL)
2373 {
2374 struct varpool_node *node = varpool_node (decl);
2375 varpool_mark_needed_node (node);
2376 /* C++ frontend use mark_decl_references to force COMDAT variables
2377 to be output that might appear dead otherwise. */
2378 node->force_output = true;
2379 }
2380 /* else do nothing - we can get various sorts of CST nodes here,
2381 which do not need to be marked. */
2382 }
2383
2384
2385 /* Follow the IDENTIFIER_TRANSPARENT_ALIAS chain starting at *ALIAS
2386 until we find an identifier that is not itself a transparent alias.
2387 Modify the alias passed to it by reference (and all aliases on the
2388 way to the ultimate target), such that they do not have to be
2389 followed again, and return the ultimate target of the alias
2390 chain. */
2391
2392 static inline tree
2393 ultimate_transparent_alias_target (tree *alias)
2394 {
2395 tree target = *alias;
2396
2397 if (IDENTIFIER_TRANSPARENT_ALIAS (target))
2398 {
2399 gcc_assert (TREE_CHAIN (target));
2400 target = ultimate_transparent_alias_target (&TREE_CHAIN (target));
2401 gcc_assert (! IDENTIFIER_TRANSPARENT_ALIAS (target)
2402 && ! TREE_CHAIN (target));
2403 *alias = target;
2404 }
2405
2406 return target;
2407 }
2408
2409 /* Output to FILE (an assembly file) a reference to NAME. If NAME
2410 starts with a *, the rest of NAME is output verbatim. Otherwise
2411 NAME is transformed in a target-specific way (usually by the
2412 addition of an underscore). */
2413
2414 void
2415 assemble_name_raw (FILE *file, const char *name)
2416 {
2417 if (name[0] == '*')
2418 fputs (&name[1], file);
2419 else
2420 ASM_OUTPUT_LABELREF (file, name);
2421 }
2422
2423 /* Like assemble_name_raw, but should be used when NAME might refer to
2424 an entity that is also represented as a tree (like a function or
2425 variable). If NAME does refer to such an entity, that entity will
2426 be marked as referenced. */
2427
2428 void
2429 assemble_name (FILE *file, const char *name)
2430 {
2431 const char *real_name;
2432 tree id;
2433
2434 real_name = targetm.strip_name_encoding (name);
2435
2436 id = maybe_get_identifier (real_name);
2437 if (id)
2438 {
2439 tree id_orig = id;
2440
2441 mark_referenced (id);
2442 ultimate_transparent_alias_target (&id);
2443 if (id != id_orig)
2444 name = IDENTIFIER_POINTER (id);
2445 gcc_assert (! TREE_CHAIN (id));
2446 }
2447
2448 assemble_name_raw (file, name);
2449 }
2450
2451 /* Allocate SIZE bytes writable static space with a gensym name
2452 and return an RTX to refer to its address. */
2453
2454 rtx
2455 assemble_static_space (unsigned HOST_WIDE_INT size)
2456 {
2457 char name[12];
2458 const char *namestring;
2459 rtx x;
2460
2461 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
2462 ++const_labelno;
2463 namestring = ggc_strdup (name);
2464
2465 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
2466 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL;
2467
2468 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
2469 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
2470 BIGGEST_ALIGNMENT);
2471 #else
2472 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
2473 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
2474 #else
2475 {
2476 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
2477 so that each uninitialized object starts on such a boundary. */
2478 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */
2479 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED
2480 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
2481 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
2482 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
2483 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
2484 }
2485 #endif
2486 #endif
2487 return x;
2488 }
2489
2490 /* Assemble the static constant template for function entry trampolines.
2491 This is done at most once per compilation.
2492 Returns an RTX for the address of the template. */
2493
2494 static GTY(()) rtx initial_trampoline;
2495
2496 #ifdef TRAMPOLINE_TEMPLATE
2497 rtx
2498 assemble_trampoline_template (void)
2499 {
2500 char label[256];
2501 const char *name;
2502 int align;
2503 rtx symbol;
2504
2505 if (initial_trampoline)
2506 return initial_trampoline;
2507
2508 /* By default, put trampoline templates in read-only data section. */
2509
2510 #ifdef TRAMPOLINE_SECTION
2511 switch_to_section (TRAMPOLINE_SECTION);
2512 #else
2513 switch_to_section (readonly_data_section);
2514 #endif
2515
2516 /* Write the assembler code to define one. */
2517 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
2518 if (align > 0)
2519 {
2520 ASM_OUTPUT_ALIGN (asm_out_file, align);
2521 }
2522
2523 targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0);
2524 TRAMPOLINE_TEMPLATE (asm_out_file);
2525
2526 /* Record the rtl to refer to it. */
2527 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
2528 name = ggc_strdup (label);
2529 symbol = gen_rtx_SYMBOL_REF (Pmode, name);
2530 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2531
2532 initial_trampoline = gen_rtx_MEM (BLKmode, symbol);
2533 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
2534
2535 return initial_trampoline;
2536 }
2537 #endif
2538 \f
2539 /* A and B are either alignments or offsets. Return the minimum alignment
2540 that may be assumed after adding the two together. */
2541
2542 static inline unsigned
2543 min_align (unsigned int a, unsigned int b)
2544 {
2545 return (a | b) & -(a | b);
2546 }
2547
2548 /* Return the assembler directive for creating a given kind of integer
2549 object. SIZE is the number of bytes in the object and ALIGNED_P
2550 indicates whether it is known to be aligned. Return NULL if the
2551 assembly dialect has no such directive.
2552
2553 The returned string should be printed at the start of a new line and
2554 be followed immediately by the object's initial value. */
2555
2556 const char *
2557 integer_asm_op (int size, int aligned_p)
2558 {
2559 struct asm_int_op *ops;
2560
2561 if (aligned_p)
2562 ops = &targetm.asm_out.aligned_op;
2563 else
2564 ops = &targetm.asm_out.unaligned_op;
2565
2566 switch (size)
2567 {
2568 case 1:
2569 return targetm.asm_out.byte_op;
2570 case 2:
2571 return ops->hi;
2572 case 4:
2573 return ops->si;
2574 case 8:
2575 return ops->di;
2576 case 16:
2577 return ops->ti;
2578 default:
2579 return NULL;
2580 }
2581 }
2582
2583 /* Use directive OP to assemble an integer object X. Print OP at the
2584 start of the line, followed immediately by the value of X. */
2585
2586 void
2587 assemble_integer_with_op (const char *op, rtx x)
2588 {
2589 fputs (op, asm_out_file);
2590 output_addr_const (asm_out_file, x);
2591 fputc ('\n', asm_out_file);
2592 }
2593
2594 /* The default implementation of the asm_out.integer target hook. */
2595
2596 bool
2597 default_assemble_integer (rtx x ATTRIBUTE_UNUSED,
2598 unsigned int size ATTRIBUTE_UNUSED,
2599 int aligned_p ATTRIBUTE_UNUSED)
2600 {
2601 const char *op = integer_asm_op (size, aligned_p);
2602 /* Avoid GAS bugs for large values. Specifically negative values whose
2603 absolute value fits in a bfd_vma, but not in a bfd_signed_vma. */
2604 if (size > UNITS_PER_WORD && size > POINTER_SIZE / BITS_PER_UNIT)
2605 return false;
2606 return op && (assemble_integer_with_op (op, x), true);
2607 }
2608
2609 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
2610 the alignment of the integer in bits. Return 1 if we were able to output
2611 the constant, otherwise 0. We must be able to output the constant,
2612 if FORCE is nonzero. */
2613
2614 bool
2615 assemble_integer (rtx x, unsigned int size, unsigned int align, int force)
2616 {
2617 int aligned_p;
2618
2619 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT));
2620
2621 /* See if the target hook can handle this kind of object. */
2622 if (targetm.asm_out.integer (x, size, aligned_p))
2623 return true;
2624
2625 /* If the object is a multi-byte one, try splitting it up. Split
2626 it into words it if is multi-word, otherwise split it into bytes. */
2627 if (size > 1)
2628 {
2629 enum machine_mode omode, imode;
2630 unsigned int subalign;
2631 unsigned int subsize, i;
2632 unsigned char mclass;
2633
2634 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1;
2635 subalign = MIN (align, subsize * BITS_PER_UNIT);
2636 if (GET_CODE (x) == CONST_FIXED)
2637 mclass = GET_MODE_CLASS (GET_MODE (x));
2638 else
2639 mclass = MODE_INT;
2640
2641 omode = mode_for_size (subsize * BITS_PER_UNIT, mclass, 0);
2642 imode = mode_for_size (size * BITS_PER_UNIT, mclass, 0);
2643
2644 for (i = 0; i < size; i += subsize)
2645 {
2646 rtx partial = simplify_subreg (omode, x, imode, i);
2647 if (!partial || !assemble_integer (partial, subsize, subalign, 0))
2648 break;
2649 }
2650 if (i == size)
2651 return true;
2652
2653 /* If we've printed some of it, but not all of it, there's no going
2654 back now. */
2655 gcc_assert (!i);
2656 }
2657
2658 gcc_assert (!force);
2659
2660 return false;
2661 }
2662 \f
2663 void
2664 assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align)
2665 {
2666 long data[4] = {0, 0, 0, 0};
2667 int i;
2668 int bitsize, nelts, nunits, units_per;
2669
2670 /* This is hairy. We have a quantity of known size. real_to_target
2671 will put it into an array of *host* longs, 32 bits per element
2672 (even if long is more than 32 bits). We need to determine the
2673 number of array elements that are occupied (nelts) and the number
2674 of *target* min-addressable units that will be occupied in the
2675 object file (nunits). We cannot assume that 32 divides the
2676 mode's bitsize (size * BITS_PER_UNIT) evenly.
2677
2678 size * BITS_PER_UNIT is used here to make sure that padding bits
2679 (which might appear at either end of the value; real_to_target
2680 will include the padding bits in its output array) are included. */
2681
2682 nunits = GET_MODE_SIZE (mode);
2683 bitsize = nunits * BITS_PER_UNIT;
2684 nelts = CEIL (bitsize, 32);
2685 units_per = 32 / BITS_PER_UNIT;
2686
2687 real_to_target (data, &d, mode);
2688
2689 /* Put out the first word with the specified alignment. */
2690 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1);
2691 nunits -= units_per;
2692
2693 /* Subsequent words need only 32-bit alignment. */
2694 align = min_align (align, 32);
2695
2696 for (i = 1; i < nelts; i++)
2697 {
2698 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1);
2699 nunits -= units_per;
2700 }
2701 }
2702 \f
2703 /* Given an expression EXP with a constant value,
2704 reduce it to the sum of an assembler symbol and an integer.
2705 Store them both in the structure *VALUE.
2706 EXP must be reducible. */
2707
2708 struct addr_const GTY(())
2709 {
2710 rtx base;
2711 HOST_WIDE_INT offset;
2712 };
2713
2714 static void
2715 decode_addr_const (tree exp, struct addr_const *value)
2716 {
2717 tree target = TREE_OPERAND (exp, 0);
2718 int offset = 0;
2719 rtx x;
2720
2721 while (1)
2722 {
2723 if (TREE_CODE (target) == COMPONENT_REF
2724 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0))
2725
2726 {
2727 offset += int_byte_position (TREE_OPERAND (target, 1));
2728 target = TREE_OPERAND (target, 0);
2729 }
2730 else if (TREE_CODE (target) == ARRAY_REF
2731 || TREE_CODE (target) == ARRAY_RANGE_REF)
2732 {
2733 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1)
2734 * tree_low_cst (TREE_OPERAND (target, 1), 0));
2735 target = TREE_OPERAND (target, 0);
2736 }
2737 else
2738 break;
2739 }
2740
2741 switch (TREE_CODE (target))
2742 {
2743 case VAR_DECL:
2744 case FUNCTION_DECL:
2745 x = DECL_RTL (target);
2746 break;
2747
2748 case LABEL_DECL:
2749 x = gen_rtx_MEM (FUNCTION_MODE,
2750 gen_rtx_LABEL_REF (Pmode, force_label_rtx (target)));
2751 break;
2752
2753 case REAL_CST:
2754 case FIXED_CST:
2755 case STRING_CST:
2756 case COMPLEX_CST:
2757 case CONSTRUCTOR:
2758 case INTEGER_CST:
2759 x = output_constant_def (target, 1);
2760 break;
2761
2762 default:
2763 gcc_unreachable ();
2764 }
2765
2766 gcc_assert (MEM_P (x));
2767 x = XEXP (x, 0);
2768
2769 value->base = x;
2770 value->offset = offset;
2771 }
2772 \f
2773 /* Uniquize all constants that appear in memory.
2774 Each constant in memory thus far output is recorded
2775 in `const_desc_table'. */
2776
2777 struct constant_descriptor_tree GTY(())
2778 {
2779 /* A MEM for the constant. */
2780 rtx rtl;
2781
2782 /* The value of the constant. */
2783 tree value;
2784
2785 /* Hash of value. Computing the hash from value each time
2786 hashfn is called can't work properly, as that means recursive
2787 use of the hash table during hash table expansion. */
2788 hashval_t hash;
2789 };
2790
2791 static GTY((param_is (struct constant_descriptor_tree)))
2792 htab_t const_desc_htab;
2793
2794 static struct constant_descriptor_tree * build_constant_desc (tree);
2795 static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int);
2796
2797 /* Compute a hash code for a constant expression. */
2798
2799 static hashval_t
2800 const_desc_hash (const void *ptr)
2801 {
2802 return ((const struct constant_descriptor_tree *)ptr)->hash;
2803 }
2804
2805 static hashval_t
2806 const_hash_1 (const tree exp)
2807 {
2808 const char *p;
2809 hashval_t hi;
2810 int len, i;
2811 enum tree_code code = TREE_CODE (exp);
2812
2813 /* Either set P and LEN to the address and len of something to hash and
2814 exit the switch or return a value. */
2815
2816 switch (code)
2817 {
2818 case INTEGER_CST:
2819 p = (char *) &TREE_INT_CST (exp);
2820 len = sizeof TREE_INT_CST (exp);
2821 break;
2822
2823 case REAL_CST:
2824 return real_hash (TREE_REAL_CST_PTR (exp));
2825
2826 case FIXED_CST:
2827 return fixed_hash (TREE_FIXED_CST_PTR (exp));
2828
2829 case STRING_CST:
2830 p = TREE_STRING_POINTER (exp);
2831 len = TREE_STRING_LENGTH (exp);
2832 break;
2833
2834 case COMPLEX_CST:
2835 return (const_hash_1 (TREE_REALPART (exp)) * 5
2836 + const_hash_1 (TREE_IMAGPART (exp)));
2837
2838 case CONSTRUCTOR:
2839 {
2840 unsigned HOST_WIDE_INT idx;
2841 tree value;
2842
2843 hi = 5 + int_size_in_bytes (TREE_TYPE (exp));
2844
2845 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, value)
2846 if (value)
2847 hi = hi * 603 + const_hash_1 (value);
2848
2849 return hi;
2850 }
2851
2852 case ADDR_EXPR:
2853 case FDESC_EXPR:
2854 {
2855 struct addr_const value;
2856
2857 decode_addr_const (exp, &value);
2858 switch (GET_CODE (value.base))
2859 {
2860 case SYMBOL_REF:
2861 /* Don't hash the address of the SYMBOL_REF;
2862 only use the offset and the symbol name. */
2863 hi = value.offset;
2864 p = XSTR (value.base, 0);
2865 for (i = 0; p[i] != 0; i++)
2866 hi = ((hi * 613) + (unsigned) (p[i]));
2867 break;
2868
2869 case LABEL_REF:
2870 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2871 break;
2872
2873 default:
2874 gcc_unreachable ();
2875 }
2876 }
2877 return hi;
2878
2879 case PLUS_EXPR:
2880 case POINTER_PLUS_EXPR:
2881 case MINUS_EXPR:
2882 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9
2883 + const_hash_1 (TREE_OPERAND (exp, 1)));
2884
2885 CASE_CONVERT:
2886 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2;
2887
2888 default:
2889 /* A language specific constant. Just hash the code. */
2890 return code;
2891 }
2892
2893 /* Compute hashing function. */
2894 hi = len;
2895 for (i = 0; i < len; i++)
2896 hi = ((hi * 613) + (unsigned) (p[i]));
2897
2898 return hi;
2899 }
2900
2901 /* Wrapper of compare_constant, for the htab interface. */
2902 static int
2903 const_desc_eq (const void *p1, const void *p2)
2904 {
2905 const struct constant_descriptor_tree *const c1
2906 = (const struct constant_descriptor_tree *) p1;
2907 const struct constant_descriptor_tree *const c2
2908 = (const struct constant_descriptor_tree *) p2;
2909 if (c1->hash != c2->hash)
2910 return 0;
2911 return compare_constant (c1->value, c2->value);
2912 }
2913
2914 /* Compare t1 and t2, and return 1 only if they are known to result in
2915 the same bit pattern on output. */
2916
2917 static int
2918 compare_constant (const tree t1, const tree t2)
2919 {
2920 enum tree_code typecode;
2921
2922 if (t1 == NULL_TREE)
2923 return t2 == NULL_TREE;
2924 if (t2 == NULL_TREE)
2925 return 0;
2926
2927 if (TREE_CODE (t1) != TREE_CODE (t2))
2928 return 0;
2929
2930 switch (TREE_CODE (t1))
2931 {
2932 case INTEGER_CST:
2933 /* Integer constants are the same only if the same width of type. */
2934 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2935 return 0;
2936 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2937 return 0;
2938 return tree_int_cst_equal (t1, t2);
2939
2940 case REAL_CST:
2941 /* Real constants are the same only if the same width of type. */
2942 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2943 return 0;
2944
2945 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2946
2947 case FIXED_CST:
2948 /* Fixed constants are the same only if the same width of type. */
2949 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2950 return 0;
2951
2952 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (t1), TREE_FIXED_CST (t2));
2953
2954 case STRING_CST:
2955 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2956 return 0;
2957
2958 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2959 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2960 TREE_STRING_LENGTH (t1)));
2961
2962 case COMPLEX_CST:
2963 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2))
2964 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2)));
2965
2966 case CONSTRUCTOR:
2967 {
2968 VEC(constructor_elt, gc) *v1, *v2;
2969 unsigned HOST_WIDE_INT idx;
2970
2971 typecode = TREE_CODE (TREE_TYPE (t1));
2972 if (typecode != TREE_CODE (TREE_TYPE (t2)))
2973 return 0;
2974
2975 if (typecode == ARRAY_TYPE)
2976 {
2977 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1));
2978 /* For arrays, check that the sizes all match. */
2979 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))
2980 || size_1 == -1
2981 || size_1 != int_size_in_bytes (TREE_TYPE (t2)))
2982 return 0;
2983 }
2984 else
2985 {
2986 /* For record and union constructors, require exact type
2987 equality. */
2988 if (TREE_TYPE (t1) != TREE_TYPE (t2))
2989 return 0;
2990 }
2991
2992 v1 = CONSTRUCTOR_ELTS (t1);
2993 v2 = CONSTRUCTOR_ELTS (t2);
2994 if (VEC_length (constructor_elt, v1)
2995 != VEC_length (constructor_elt, v2))
2996 return 0;
2997
2998 for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx)
2999 {
3000 constructor_elt *c1 = VEC_index (constructor_elt, v1, idx);
3001 constructor_elt *c2 = VEC_index (constructor_elt, v2, idx);
3002
3003 /* Check that each value is the same... */
3004 if (!compare_constant (c1->value, c2->value))
3005 return 0;
3006 /* ... and that they apply to the same fields! */
3007 if (typecode == ARRAY_TYPE)
3008 {
3009 if (!compare_constant (c1->index, c2->index))
3010 return 0;
3011 }
3012 else
3013 {
3014 if (c1->index != c2->index)
3015 return 0;
3016 }
3017 }
3018
3019 return 1;
3020 }
3021
3022 case ADDR_EXPR:
3023 case FDESC_EXPR:
3024 {
3025 struct addr_const value1, value2;
3026
3027 decode_addr_const (t1, &value1);
3028 decode_addr_const (t2, &value2);
3029 return (value1.offset == value2.offset
3030 && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0);
3031 }
3032
3033 case PLUS_EXPR:
3034 case POINTER_PLUS_EXPR:
3035 case MINUS_EXPR:
3036 case RANGE_EXPR:
3037 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
3038 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
3039
3040 CASE_CONVERT:
3041 case VIEW_CONVERT_EXPR:
3042 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3043
3044 default:
3045 return 0;
3046 }
3047
3048 gcc_unreachable ();
3049 }
3050 \f
3051 /* Make a copy of the whole tree structure for a constant. This
3052 handles the same types of nodes that compare_constant handles. */
3053
3054 static tree
3055 copy_constant (tree exp)
3056 {
3057 switch (TREE_CODE (exp))
3058 {
3059 case ADDR_EXPR:
3060 /* For ADDR_EXPR, we do not want to copy the decl whose address
3061 is requested. We do want to copy constants though. */
3062 if (CONSTANT_CLASS_P (TREE_OPERAND (exp, 0)))
3063 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
3064 copy_constant (TREE_OPERAND (exp, 0)));
3065 else
3066 return copy_node (exp);
3067
3068 case INTEGER_CST:
3069 case REAL_CST:
3070 case FIXED_CST:
3071 case STRING_CST:
3072 return copy_node (exp);
3073
3074 case COMPLEX_CST:
3075 return build_complex (TREE_TYPE (exp),
3076 copy_constant (TREE_REALPART (exp)),
3077 copy_constant (TREE_IMAGPART (exp)));
3078
3079 case PLUS_EXPR:
3080 case POINTER_PLUS_EXPR:
3081 case MINUS_EXPR:
3082 return build2 (TREE_CODE (exp), TREE_TYPE (exp),
3083 copy_constant (TREE_OPERAND (exp, 0)),
3084 copy_constant (TREE_OPERAND (exp, 1)));
3085
3086 CASE_CONVERT:
3087 case VIEW_CONVERT_EXPR:
3088 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
3089 copy_constant (TREE_OPERAND (exp, 0)));
3090
3091 case CONSTRUCTOR:
3092 {
3093 tree copy = copy_node (exp);
3094 VEC(constructor_elt, gc) *v;
3095 unsigned HOST_WIDE_INT idx;
3096 tree purpose, value;
3097
3098 v = VEC_alloc(constructor_elt, gc, VEC_length(constructor_elt,
3099 CONSTRUCTOR_ELTS (exp)));
3100 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (exp), idx, purpose, value)
3101 {
3102 constructor_elt *ce = VEC_quick_push (constructor_elt, v, NULL);
3103 ce->index = purpose;
3104 ce->value = copy_constant (value);
3105 }
3106 CONSTRUCTOR_ELTS (copy) = v;
3107 return copy;
3108 }
3109
3110 default:
3111 gcc_unreachable ();
3112 }
3113 }
3114 \f
3115 /* Return the alignment of constant EXP in bits. */
3116
3117 static unsigned int
3118 get_constant_alignment (tree exp)
3119 {
3120 unsigned int align;
3121
3122 align = TYPE_ALIGN (TREE_TYPE (exp));
3123 #ifdef CONSTANT_ALIGNMENT
3124 align = CONSTANT_ALIGNMENT (exp, align);
3125 #endif
3126 return align;
3127 }
3128
3129 /* Return the section into which constant EXP should be placed. */
3130
3131 static section *
3132 get_constant_section (tree exp)
3133 {
3134 if (IN_NAMED_SECTION (exp))
3135 return get_named_section (exp, NULL, compute_reloc_for_constant (exp));
3136 else
3137 return targetm.asm_out.select_section (exp,
3138 compute_reloc_for_constant (exp),
3139 get_constant_alignment (exp));
3140 }
3141
3142 /* Return the size of constant EXP in bytes. */
3143
3144 static HOST_WIDE_INT
3145 get_constant_size (tree exp)
3146 {
3147 HOST_WIDE_INT size;
3148
3149 size = int_size_in_bytes (TREE_TYPE (exp));
3150 if (TREE_CODE (exp) == STRING_CST)
3151 size = MAX (TREE_STRING_LENGTH (exp), size);
3152 return size;
3153 }
3154
3155 /* Subroutine of output_constant_def:
3156 No constant equal to EXP is known to have been output.
3157 Make a constant descriptor to enter EXP in the hash table.
3158 Assign the label number and construct RTL to refer to the
3159 constant's location in memory.
3160 Caller is responsible for updating the hash table. */
3161
3162 static struct constant_descriptor_tree *
3163 build_constant_desc (tree exp)
3164 {
3165 rtx symbol;
3166 rtx rtl;
3167 char label[256];
3168 int labelno;
3169 struct constant_descriptor_tree *desc;
3170
3171 desc = GGC_NEW (struct constant_descriptor_tree);
3172 desc->value = copy_constant (exp);
3173
3174 /* Propagate marked-ness to copied constant. */
3175 if (flag_mudflap && mf_marked_p (exp))
3176 mf_mark (desc->value);
3177
3178 /* Create a string containing the label name, in LABEL. */
3179 labelno = const_labelno++;
3180 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno);
3181
3182 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
3183 if (use_object_blocks_p ())
3184 {
3185 section *sect = get_constant_section (exp);
3186 symbol = create_block_symbol (ggc_strdup (label),
3187 get_block_for_section (sect), -1);
3188 }
3189 else
3190 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3191 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3192 SET_SYMBOL_REF_DECL (symbol, desc->value);
3193 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3194
3195 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol);
3196 set_mem_attributes (rtl, exp, 1);
3197 set_mem_alias_set (rtl, 0);
3198 set_mem_alias_set (rtl, const_alias_set);
3199
3200 /* Set flags or add text to the name to record information, such as
3201 that it is a local symbol. If the name is changed, the macro
3202 ASM_OUTPUT_LABELREF will have to know how to strip this
3203 information. This call might invalidate our local variable
3204 SYMBOL; we can't use it afterward. */
3205
3206 targetm.encode_section_info (exp, rtl, true);
3207
3208 desc->rtl = rtl;
3209
3210 return desc;
3211 }
3212
3213 /* Return an rtx representing a reference to constant data in memory
3214 for the constant expression EXP.
3215
3216 If assembler code for such a constant has already been output,
3217 return an rtx to refer to it.
3218 Otherwise, output such a constant in memory
3219 and generate an rtx for it.
3220
3221 If DEFER is nonzero, this constant can be deferred and output only
3222 if referenced in the function after all optimizations.
3223
3224 `const_desc_table' records which constants already have label strings. */
3225
3226 rtx
3227 output_constant_def (tree exp, int defer)
3228 {
3229 struct constant_descriptor_tree *desc;
3230 struct constant_descriptor_tree key;
3231 void **loc;
3232
3233 /* Look up EXP in the table of constant descriptors. If we didn't find
3234 it, create a new one. */
3235 key.value = exp;
3236 key.hash = const_hash_1 (exp);
3237 loc = htab_find_slot_with_hash (const_desc_htab, &key, key.hash, INSERT);
3238
3239 desc = (struct constant_descriptor_tree *) *loc;
3240 if (desc == 0)
3241 {
3242 desc = build_constant_desc (exp);
3243 desc->hash = key.hash;
3244 *loc = desc;
3245 }
3246
3247 maybe_output_constant_def_contents (desc, defer);
3248 return desc->rtl;
3249 }
3250
3251 /* Subroutine of output_constant_def: Decide whether or not we need to
3252 output the constant DESC now, and if so, do it. */
3253 static void
3254 maybe_output_constant_def_contents (struct constant_descriptor_tree *desc,
3255 int defer)
3256 {
3257 rtx symbol = XEXP (desc->rtl, 0);
3258 tree exp = desc->value;
3259
3260 if (flag_syntax_only)
3261 return;
3262
3263 if (TREE_ASM_WRITTEN (exp))
3264 /* Already output; don't do it again. */
3265 return;
3266
3267 /* We can always defer constants as long as the context allows
3268 doing so. */
3269 if (defer)
3270 {
3271 /* Increment n_deferred_constants if it exists. It needs to be at
3272 least as large as the number of constants actually referred to
3273 by the function. If it's too small we'll stop looking too early
3274 and fail to emit constants; if it's too large we'll only look
3275 through the entire function when we could have stopped earlier. */
3276 if (cfun)
3277 n_deferred_constants++;
3278 return;
3279 }
3280
3281 output_constant_def_contents (symbol);
3282 }
3283
3284 /* Subroutine of output_constant_def_contents. Output the definition
3285 of constant EXP, which is pointed to by label LABEL. ALIGN is the
3286 constant's alignment in bits. */
3287
3288 static void
3289 assemble_constant_contents (tree exp, const char *label, unsigned int align)
3290 {
3291 HOST_WIDE_INT size;
3292
3293 size = get_constant_size (exp);
3294
3295 /* Do any machine/system dependent processing of the constant. */
3296 #ifdef ASM_DECLARE_CONSTANT_NAME
3297 ASM_DECLARE_CONSTANT_NAME (asm_out_file, label, exp, size);
3298 #else
3299 /* Standard thing is just output label for the constant. */
3300 ASM_OUTPUT_LABEL (asm_out_file, label);
3301 #endif /* ASM_DECLARE_CONSTANT_NAME */
3302
3303 /* Output the value of EXP. */
3304 output_constant (exp, size, align);
3305 }
3306
3307 /* We must output the constant data referred to by SYMBOL; do so. */
3308
3309 static void
3310 output_constant_def_contents (rtx symbol)
3311 {
3312 tree exp = SYMBOL_REF_DECL (symbol);
3313 unsigned int align;
3314
3315 /* Make sure any other constants whose addresses appear in EXP
3316 are assigned label numbers. */
3317 output_addressed_constants (exp);
3318
3319 /* We are no longer deferring this constant. */
3320 TREE_ASM_WRITTEN (exp) = 1;
3321
3322 /* If the constant is part of an object block, make sure that the
3323 decl has been positioned within its block, but do not write out
3324 its definition yet. output_object_blocks will do that later. */
3325 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
3326 place_block_symbol (symbol);
3327 else
3328 {
3329 switch_to_section (get_constant_section (exp));
3330 align = get_constant_alignment (exp);
3331 if (align > BITS_PER_UNIT)
3332 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
3333 assemble_constant_contents (exp, XSTR (symbol, 0), align);
3334 }
3335 if (flag_mudflap)
3336 mudflap_enqueue_constant (exp);
3337 }
3338
3339 /* Look up EXP in the table of constant descriptors. Return the rtl
3340 if it has been emitted, else null. */
3341
3342 rtx
3343 lookup_constant_def (tree exp)
3344 {
3345 struct constant_descriptor_tree *desc;
3346 struct constant_descriptor_tree key;
3347
3348 key.value = exp;
3349 key.hash = const_hash_1 (exp);
3350 desc = (struct constant_descriptor_tree *)
3351 htab_find_with_hash (const_desc_htab, &key, key.hash);
3352
3353 return (desc ? desc->rtl : NULL_RTX);
3354 }
3355 \f
3356 /* Used in the hash tables to avoid outputting the same constant
3357 twice. Unlike 'struct constant_descriptor_tree', RTX constants
3358 are output once per function, not once per file. */
3359 /* ??? Only a few targets need per-function constant pools. Most
3360 can use one per-file pool. Should add a targetm bit to tell the
3361 difference. */
3362
3363 struct rtx_constant_pool GTY(())
3364 {
3365 /* Pointers to first and last constant in pool, as ordered by offset. */
3366 struct constant_descriptor_rtx *first;
3367 struct constant_descriptor_rtx *last;
3368
3369 /* Hash facility for making memory-constants from constant rtl-expressions.
3370 It is used on RISC machines where immediate integer arguments and
3371 constant addresses are restricted so that such constants must be stored
3372 in memory. */
3373 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab;
3374
3375 /* Current offset in constant pool (does not include any
3376 machine-specific header). */
3377 HOST_WIDE_INT offset;
3378 };
3379
3380 struct constant_descriptor_rtx GTY((chain_next ("%h.next")))
3381 {
3382 struct constant_descriptor_rtx *next;
3383 rtx mem;
3384 rtx sym;
3385 rtx constant;
3386 HOST_WIDE_INT offset;
3387 hashval_t hash;
3388 enum machine_mode mode;
3389 unsigned int align;
3390 int labelno;
3391 int mark;
3392 };
3393
3394 /* Hash and compare functions for const_rtx_htab. */
3395
3396 static hashval_t
3397 const_desc_rtx_hash (const void *ptr)
3398 {
3399 const struct constant_descriptor_rtx *const desc
3400 = (const struct constant_descriptor_rtx *) ptr;
3401 return desc->hash;
3402 }
3403
3404 static int
3405 const_desc_rtx_eq (const void *a, const void *b)
3406 {
3407 const struct constant_descriptor_rtx *const x
3408 = (const struct constant_descriptor_rtx *) a;
3409 const struct constant_descriptor_rtx *const y
3410 = (const struct constant_descriptor_rtx *) b;
3411
3412 if (x->mode != y->mode)
3413 return 0;
3414 return rtx_equal_p (x->constant, y->constant);
3415 }
3416
3417 /* This is the worker function for const_rtx_hash, called via for_each_rtx. */
3418
3419 static int
3420 const_rtx_hash_1 (rtx *xp, void *data)
3421 {
3422 unsigned HOST_WIDE_INT hwi;
3423 enum machine_mode mode;
3424 enum rtx_code code;
3425 hashval_t h, *hp;
3426 rtx x;
3427
3428 x = *xp;
3429 code = GET_CODE (x);
3430 mode = GET_MODE (x);
3431 h = (hashval_t) code * 1048573 + mode;
3432
3433 switch (code)
3434 {
3435 case CONST_INT:
3436 hwi = INTVAL (x);
3437 fold_hwi:
3438 {
3439 const int shift = sizeof (hashval_t) * CHAR_BIT;
3440 const int n = sizeof (HOST_WIDE_INT) / sizeof (hashval_t);
3441 int i;
3442
3443 h ^= (hashval_t) hwi;
3444 for (i = 1; i < n; ++i)
3445 {
3446 hwi >>= shift;
3447 h ^= (hashval_t) hwi;
3448 }
3449 }
3450 break;
3451
3452 case CONST_DOUBLE:
3453 if (mode == VOIDmode)
3454 {
3455 hwi = CONST_DOUBLE_LOW (x) ^ CONST_DOUBLE_HIGH (x);
3456 goto fold_hwi;
3457 }
3458 else
3459 h ^= real_hash (CONST_DOUBLE_REAL_VALUE (x));
3460 break;
3461
3462 case CONST_FIXED:
3463 h ^= fixed_hash (CONST_FIXED_VALUE (x));
3464 break;
3465
3466 case CONST_VECTOR:
3467 {
3468 int i;
3469 for (i = XVECLEN (x, 0); i-- > 0; )
3470 h = h * 251 + const_rtx_hash_1 (&XVECEXP (x, 0, i), data);
3471 }
3472 break;
3473
3474 case SYMBOL_REF:
3475 h ^= htab_hash_string (XSTR (x, 0));
3476 break;
3477
3478 case LABEL_REF:
3479 h = h * 251 + CODE_LABEL_NUMBER (XEXP (x, 0));
3480 break;
3481
3482 case UNSPEC:
3483 case UNSPEC_VOLATILE:
3484 h = h * 251 + XINT (x, 1);
3485 break;
3486
3487 default:
3488 break;
3489 }
3490
3491 hp = (hashval_t *) data;
3492 *hp = *hp * 509 + h;
3493 return 0;
3494 }
3495
3496 /* Compute a hash value for X, which should be a constant. */
3497
3498 static hashval_t
3499 const_rtx_hash (rtx x)
3500 {
3501 hashval_t h = 0;
3502 for_each_rtx (&x, const_rtx_hash_1, &h);
3503 return h;
3504 }
3505
3506 \f
3507 /* Create and return a new rtx constant pool. */
3508
3509 static struct rtx_constant_pool *
3510 create_constant_pool (void)
3511 {
3512 struct rtx_constant_pool *pool;
3513
3514 pool = GGC_NEW (struct rtx_constant_pool);
3515 pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash,
3516 const_desc_rtx_eq, NULL);
3517 pool->first = NULL;
3518 pool->last = NULL;
3519 pool->offset = 0;
3520 return pool;
3521 }
3522
3523 /* Initialize constant pool hashing for a new function. */
3524
3525 void
3526 init_varasm_status (void)
3527 {
3528 crtl->varasm.pool = create_constant_pool ();
3529 crtl->varasm.deferred_constants = 0;
3530 }
3531 \f
3532 /* Given a MINUS expression, simplify it if both sides
3533 include the same symbol. */
3534
3535 rtx
3536 simplify_subtraction (rtx x)
3537 {
3538 rtx r = simplify_rtx (x);
3539 return r ? r : x;
3540 }
3541 \f
3542 /* Given a constant rtx X, make (or find) a memory constant for its value
3543 and return a MEM rtx to refer to it in memory. */
3544
3545 rtx
3546 force_const_mem (enum machine_mode mode, rtx x)
3547 {
3548 struct constant_descriptor_rtx *desc, tmp;
3549 struct rtx_constant_pool *pool;
3550 char label[256];
3551 rtx def, symbol;
3552 hashval_t hash;
3553 unsigned int align;
3554 void **slot;
3555
3556 /* If we're not allowed to drop X into the constant pool, don't. */
3557 if (targetm.cannot_force_const_mem (x))
3558 return NULL_RTX;
3559
3560 /* Record that this function has used a constant pool entry. */
3561 crtl->uses_const_pool = 1;
3562
3563 /* Decide which pool to use. */
3564 pool = (targetm.use_blocks_for_constant_p (mode, x)
3565 ? shared_constant_pool
3566 : crtl->varasm.pool);
3567
3568 /* Lookup the value in the hashtable. */
3569 tmp.constant = x;
3570 tmp.mode = mode;
3571 hash = const_rtx_hash (x);
3572 slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT);
3573 desc = (struct constant_descriptor_rtx *) *slot;
3574
3575 /* If the constant was already present, return its memory. */
3576 if (desc)
3577 return copy_rtx (desc->mem);
3578
3579 /* Otherwise, create a new descriptor. */
3580 desc = GGC_NEW (struct constant_descriptor_rtx);
3581 *slot = desc;
3582
3583 /* Align the location counter as required by EXP's data type. */
3584 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode);
3585 #ifdef CONSTANT_ALIGNMENT
3586 {
3587 tree type = lang_hooks.types.type_for_mode (mode, 0);
3588 if (type != NULL_TREE)
3589 align = CONSTANT_ALIGNMENT (make_tree (type, x), align);
3590 }
3591 #endif
3592
3593 pool->offset += (align / BITS_PER_UNIT) - 1;
3594 pool->offset &= ~ ((align / BITS_PER_UNIT) - 1);
3595
3596 desc->next = NULL;
3597 desc->constant = tmp.constant;
3598 desc->offset = pool->offset;
3599 desc->hash = hash;
3600 desc->mode = mode;
3601 desc->align = align;
3602 desc->labelno = const_labelno;
3603 desc->mark = 0;
3604
3605 pool->offset += GET_MODE_SIZE (mode);
3606 if (pool->last)
3607 pool->last->next = desc;
3608 else
3609 pool->first = pool->last = desc;
3610 pool->last = desc;
3611
3612 /* Create a string containing the label name, in LABEL. */
3613 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
3614 ++const_labelno;
3615
3616 /* Construct the SYMBOL_REF. Make sure to mark it as belonging to
3617 the constants pool. */
3618 if (use_object_blocks_p () && targetm.use_blocks_for_constant_p (mode, x))
3619 {
3620 section *sect = targetm.asm_out.select_rtx_section (mode, x, align);
3621 symbol = create_block_symbol (ggc_strdup (label),
3622 get_block_for_section (sect), -1);
3623 }
3624 else
3625 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3626 desc->sym = symbol;
3627 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3628 CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3629 SET_SYMBOL_REF_CONSTANT (symbol, desc);
3630
3631 /* Construct the MEM. */
3632 desc->mem = def = gen_const_mem (mode, symbol);
3633 set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1);
3634 set_mem_align (def, align);
3635
3636 /* If we're dropping a label to the constant pool, make sure we
3637 don't delete it. */
3638 if (GET_CODE (x) == LABEL_REF)
3639 LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
3640
3641 return copy_rtx (def);
3642 }
3643 \f
3644 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
3645
3646 rtx
3647 get_pool_constant (rtx addr)
3648 {
3649 return SYMBOL_REF_CONSTANT (addr)->constant;
3650 }
3651
3652 /* Given a constant pool SYMBOL_REF, return the corresponding constant
3653 and whether it has been output or not. */
3654
3655 rtx
3656 get_pool_constant_mark (rtx addr, bool *pmarked)
3657 {
3658 struct constant_descriptor_rtx *desc;
3659
3660 desc = SYMBOL_REF_CONSTANT (addr);
3661 *pmarked = (desc->mark != 0);
3662 return desc->constant;
3663 }
3664
3665 /* Similar, return the mode. */
3666
3667 enum machine_mode
3668 get_pool_mode (const_rtx addr)
3669 {
3670 return SYMBOL_REF_CONSTANT (addr)->mode;
3671 }
3672
3673 /* Return the size of the constant pool. */
3674
3675 int
3676 get_pool_size (void)
3677 {
3678 return crtl->varasm.pool->offset;
3679 }
3680 \f
3681 /* Worker function for output_constant_pool_1. Emit assembly for X
3682 in MODE with known alignment ALIGN. */
3683
3684 static void
3685 output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align)
3686 {
3687 switch (GET_MODE_CLASS (mode))
3688 {
3689 case MODE_FLOAT:
3690 case MODE_DECIMAL_FLOAT:
3691 {
3692 REAL_VALUE_TYPE r;
3693
3694 gcc_assert (GET_CODE (x) == CONST_DOUBLE);
3695 REAL_VALUE_FROM_CONST_DOUBLE (r, x);
3696 assemble_real (r, mode, align);
3697 break;
3698 }
3699
3700 case MODE_INT:
3701 case MODE_PARTIAL_INT:
3702 case MODE_FRACT:
3703 case MODE_UFRACT:
3704 case MODE_ACCUM:
3705 case MODE_UACCUM:
3706 assemble_integer (x, GET_MODE_SIZE (mode), align, 1);
3707 break;
3708
3709 case MODE_VECTOR_FLOAT:
3710 case MODE_VECTOR_INT:
3711 case MODE_VECTOR_FRACT:
3712 case MODE_VECTOR_UFRACT:
3713 case MODE_VECTOR_ACCUM:
3714 case MODE_VECTOR_UACCUM:
3715 {
3716 int i, units;
3717 enum machine_mode submode = GET_MODE_INNER (mode);
3718 unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode));
3719
3720 gcc_assert (GET_CODE (x) == CONST_VECTOR);
3721 units = CONST_VECTOR_NUNITS (x);
3722
3723 for (i = 0; i < units; i++)
3724 {
3725 rtx elt = CONST_VECTOR_ELT (x, i);
3726 output_constant_pool_2 (submode, elt, i ? subalign : align);
3727 }
3728 }
3729 break;
3730
3731 default:
3732 gcc_unreachable ();
3733 }
3734 }
3735
3736 /* Worker function for output_constant_pool. Emit constant DESC,
3737 giving it ALIGN bits of alignment. */
3738
3739 static void
3740 output_constant_pool_1 (struct constant_descriptor_rtx *desc,
3741 unsigned int align)
3742 {
3743 rtx x, tmp;
3744
3745 x = desc->constant;
3746
3747 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3748 whose CODE_LABEL has been deleted. This can occur if a jump table
3749 is eliminated by optimization. If so, write a constant of zero
3750 instead. Note that this can also happen by turning the
3751 CODE_LABEL into a NOTE. */
3752 /* ??? This seems completely and utterly wrong. Certainly it's
3753 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper
3754 functioning even with INSN_DELETED_P and friends. */
3755
3756 tmp = x;
3757 switch (GET_CODE (tmp))
3758 {
3759 case CONST:
3760 if (GET_CODE (XEXP (tmp, 0)) != PLUS
3761 || GET_CODE (XEXP (XEXP (tmp, 0), 0)) != LABEL_REF)
3762 break;
3763 tmp = XEXP (XEXP (tmp, 0), 0);
3764 /* FALLTHRU */
3765
3766 case LABEL_REF:
3767 tmp = XEXP (tmp, 0);
3768 gcc_assert (!INSN_DELETED_P (tmp));
3769 gcc_assert (!NOTE_P (tmp)
3770 || NOTE_KIND (tmp) != NOTE_INSN_DELETED);
3771 break;
3772
3773 default:
3774 break;
3775 }
3776
3777 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3778 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode,
3779 align, desc->labelno, done);
3780 #endif
3781
3782 assemble_align (align);
3783
3784 /* Output the label. */
3785 targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno);
3786
3787 /* Output the data. */
3788 output_constant_pool_2 (desc->mode, x, align);
3789
3790 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS
3791 sections have proper size. */
3792 if (align > GET_MODE_BITSIZE (desc->mode)
3793 && in_section
3794 && (in_section->common.flags & SECTION_MERGE))
3795 assemble_align (align);
3796
3797 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3798 done:
3799 #endif
3800 return;
3801 }
3802
3803 /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
3804 to as used. Emit referenced deferred strings. This function can
3805 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */
3806
3807 static int
3808 mark_constant (rtx *current_rtx, void *data ATTRIBUTE_UNUSED)
3809 {
3810 rtx x = *current_rtx;
3811
3812 if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF)
3813 return 0;
3814
3815 if (CONSTANT_POOL_ADDRESS_P (x))
3816 {
3817 struct constant_descriptor_rtx *desc = SYMBOL_REF_CONSTANT (x);
3818 if (desc->mark == 0)
3819 {
3820 desc->mark = 1;
3821 for_each_rtx (&desc->constant, mark_constant, NULL);
3822 }
3823 }
3824 else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
3825 {
3826 tree exp = SYMBOL_REF_DECL (x);
3827 if (!TREE_ASM_WRITTEN (exp))
3828 {
3829 n_deferred_constants--;
3830 output_constant_def_contents (x);
3831 }
3832 }
3833
3834 return -1;
3835 }
3836
3837 /* Look through appropriate parts of INSN, marking all entries in the
3838 constant pool which are actually being used. Entries that are only
3839 referenced by other constants are also marked as used. Emit
3840 deferred strings that are used. */
3841
3842 static void
3843 mark_constants (rtx insn)
3844 {
3845 if (!INSN_P (insn))
3846 return;
3847
3848 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3849 insns, not any notes that may be attached. We don't want to mark
3850 a constant just because it happens to appear in a REG_EQUIV note. */
3851 if (GET_CODE (PATTERN (insn)) == SEQUENCE)
3852 {
3853 rtx seq = PATTERN (insn);
3854 int i, n = XVECLEN (seq, 0);
3855 for (i = 0; i < n; ++i)
3856 {
3857 rtx subinsn = XVECEXP (seq, 0, i);
3858 if (INSN_P (subinsn))
3859 for_each_rtx (&PATTERN (subinsn), mark_constant, NULL);
3860 }
3861 }
3862 else
3863 for_each_rtx (&PATTERN (insn), mark_constant, NULL);
3864 }
3865
3866 /* Look through the instructions for this function, and mark all the
3867 entries in POOL which are actually being used. Emit deferred constants
3868 which have indeed been used. */
3869
3870 static void
3871 mark_constant_pool (void)
3872 {
3873 rtx insn, link;
3874
3875 if (!crtl->uses_const_pool && n_deferred_constants == 0)
3876 return;
3877
3878 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3879 mark_constants (insn);
3880
3881 for (link = crtl->epilogue_delay_list;
3882 link;
3883 link = XEXP (link, 1))
3884 mark_constants (XEXP (link, 0));
3885 }
3886
3887 /* Write all the constants in POOL. */
3888
3889 static void
3890 output_constant_pool_contents (struct rtx_constant_pool *pool)
3891 {
3892 struct constant_descriptor_rtx *desc;
3893
3894 for (desc = pool->first; desc ; desc = desc->next)
3895 if (desc->mark)
3896 {
3897 /* If the constant is part of an object_block, make sure that
3898 the constant has been positioned within its block, but do not
3899 write out its definition yet. output_object_blocks will do
3900 that later. */
3901 if (SYMBOL_REF_HAS_BLOCK_INFO_P (desc->sym)
3902 && SYMBOL_REF_BLOCK (desc->sym))
3903 place_block_symbol (desc->sym);
3904 else
3905 {
3906 switch_to_section (targetm.asm_out.select_rtx_section
3907 (desc->mode, desc->constant, desc->align));
3908 output_constant_pool_1 (desc, desc->align);
3909 }
3910 }
3911 }
3912
3913 /* Mark all constants that are used in the current function, then write
3914 out the function's private constant pool. */
3915
3916 static void
3917 output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
3918 tree fndecl ATTRIBUTE_UNUSED)
3919 {
3920 struct rtx_constant_pool *pool = crtl->varasm.pool;
3921
3922 /* It is possible for gcc to call force_const_mem and then to later
3923 discard the instructions which refer to the constant. In such a
3924 case we do not need to output the constant. */
3925 mark_constant_pool ();
3926
3927 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3928 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset);
3929 #endif
3930
3931 output_constant_pool_contents (pool);
3932
3933 #ifdef ASM_OUTPUT_POOL_EPILOGUE
3934 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset);
3935 #endif
3936 }
3937 \f
3938 /* Write the contents of the shared constant pool. */
3939
3940 void
3941 output_shared_constant_pool (void)
3942 {
3943 output_constant_pool_contents (shared_constant_pool);
3944 }
3945 \f
3946 /* Determine what kind of relocations EXP may need. */
3947
3948 int
3949 compute_reloc_for_constant (tree exp)
3950 {
3951 int reloc = 0, reloc2;
3952 tree tem;
3953
3954 switch (TREE_CODE (exp))
3955 {
3956 case ADDR_EXPR:
3957 case FDESC_EXPR:
3958 /* Go inside any operations that get_inner_reference can handle and see
3959 if what's inside is a constant: no need to do anything here for
3960 addresses of variables or functions. */
3961 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3962 tem = TREE_OPERAND (tem, 0))
3963 ;
3964
3965 if (TREE_PUBLIC (tem))
3966 reloc |= 2;
3967 else
3968 reloc |= 1;
3969 break;
3970
3971 case PLUS_EXPR:
3972 case POINTER_PLUS_EXPR:
3973 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3974 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3975 break;
3976
3977 case MINUS_EXPR:
3978 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3979 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3980 /* The difference of two local labels is computable at link time. */
3981 if (reloc == 1 && reloc2 == 1)
3982 reloc = 0;
3983 else
3984 reloc |= reloc2;
3985 break;
3986
3987 CASE_CONVERT:
3988 case VIEW_CONVERT_EXPR:
3989 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3990 break;
3991
3992 case CONSTRUCTOR:
3993 {
3994 unsigned HOST_WIDE_INT idx;
3995 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
3996 if (tem != 0)
3997 reloc |= compute_reloc_for_constant (tem);
3998 }
3999 break;
4000
4001 default:
4002 break;
4003 }
4004 return reloc;
4005 }
4006
4007 /* Find all the constants whose addresses are referenced inside of EXP,
4008 and make sure assembler code with a label has been output for each one.
4009 Indicate whether an ADDR_EXPR has been encountered. */
4010
4011 static void
4012 output_addressed_constants (tree exp)
4013 {
4014 tree tem;
4015
4016 switch (TREE_CODE (exp))
4017 {
4018 case ADDR_EXPR:
4019 case FDESC_EXPR:
4020 /* Go inside any operations that get_inner_reference can handle and see
4021 if what's inside is a constant: no need to do anything here for
4022 addresses of variables or functions. */
4023 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
4024 tem = TREE_OPERAND (tem, 0))
4025 ;
4026
4027 /* If we have an initialized CONST_DECL, retrieve the initializer. */
4028 if (TREE_CODE (tem) == CONST_DECL && DECL_INITIAL (tem))
4029 tem = DECL_INITIAL (tem);
4030
4031 if (CONSTANT_CLASS_P (tem) || TREE_CODE (tem) == CONSTRUCTOR)
4032 output_constant_def (tem, 0);
4033 break;
4034
4035 case PLUS_EXPR:
4036 case POINTER_PLUS_EXPR:
4037 case MINUS_EXPR:
4038 output_addressed_constants (TREE_OPERAND (exp, 1));
4039 /* Fall through. */
4040
4041 CASE_CONVERT:
4042 case VIEW_CONVERT_EXPR:
4043 output_addressed_constants (TREE_OPERAND (exp, 0));
4044 break;
4045
4046 case CONSTRUCTOR:
4047 {
4048 unsigned HOST_WIDE_INT idx;
4049 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
4050 if (tem != 0)
4051 output_addressed_constants (tem);
4052 }
4053 break;
4054
4055 default:
4056 break;
4057 }
4058 }
4059 \f
4060 /* Whether a constructor CTOR is a valid static constant initializer if all
4061 its elements are. This used to be internal to initializer_constant_valid_p
4062 and has been exposed to let other functions like categorize_ctor_elements
4063 evaluate the property while walking a constructor for other purposes. */
4064
4065 bool
4066 constructor_static_from_elts_p (const_tree ctor)
4067 {
4068 return (TREE_CONSTANT (ctor)
4069 && (TREE_CODE (TREE_TYPE (ctor)) == UNION_TYPE
4070 || TREE_CODE (TREE_TYPE (ctor)) == RECORD_TYPE)
4071 && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (ctor)));
4072 }
4073
4074 /* A subroutine of initializer_constant_valid_p. VALUE is either a
4075 MINUS_EXPR or a POINTER_PLUS_EXPR. This looks for cases of VALUE
4076 which are valid when ENDTYPE is an integer of any size; in
4077 particular, this does not accept a pointer minus a constant. This
4078 returns null_pointer_node if the VALUE is an absolute constant
4079 which can be used to initialize a static variable. Otherwise it
4080 returns NULL. */
4081
4082 static tree
4083 narrowing_initializer_constant_valid_p (tree value, tree endtype)
4084 {
4085 tree op0, op1;
4086
4087 if (!INTEGRAL_TYPE_P (endtype))
4088 return NULL_TREE;
4089
4090 op0 = TREE_OPERAND (value, 0);
4091 op1 = TREE_OPERAND (value, 1);
4092
4093 /* Like STRIP_NOPS except allow the operand mode to widen. This
4094 works around a feature of fold that simplifies (int)(p1 - p2) to
4095 ((int)p1 - (int)p2) under the theory that the narrower operation
4096 is cheaper. */
4097
4098 while (CONVERT_EXPR_P (op0)
4099 || TREE_CODE (op0) == NON_LVALUE_EXPR)
4100 {
4101 tree inner = TREE_OPERAND (op0, 0);
4102 if (inner == error_mark_node
4103 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4104 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))
4105 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4106 break;
4107 op0 = inner;
4108 }
4109
4110 while (CONVERT_EXPR_P (op1)
4111 || TREE_CODE (op1) == NON_LVALUE_EXPR)
4112 {
4113 tree inner = TREE_OPERAND (op1, 0);
4114 if (inner == error_mark_node
4115 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4116 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))
4117 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4118 break;
4119 op1 = inner;
4120 }
4121
4122 op0 = initializer_constant_valid_p (op0, endtype);
4123 op1 = initializer_constant_valid_p (op1, endtype);
4124
4125 /* Both initializers must be known. */
4126 if (op0 && op1)
4127 {
4128 if (op0 == op1)
4129 return null_pointer_node;
4130
4131 /* Support differences between labels. */
4132 if (TREE_CODE (op0) == LABEL_DECL
4133 && TREE_CODE (op1) == LABEL_DECL)
4134 return null_pointer_node;
4135
4136 if (TREE_CODE (op0) == STRING_CST
4137 && TREE_CODE (op1) == STRING_CST
4138 && operand_equal_p (op0, op1, 1))
4139 return null_pointer_node;
4140 }
4141
4142 return NULL_TREE;
4143 }
4144
4145 /* Return nonzero if VALUE is a valid constant-valued expression
4146 for use in initializing a static variable; one that can be an
4147 element of a "constant" initializer.
4148
4149 Return null_pointer_node if the value is absolute;
4150 if it is relocatable, return the variable that determines the relocation.
4151 We assume that VALUE has been folded as much as possible;
4152 therefore, we do not need to check for such things as
4153 arithmetic-combinations of integers. */
4154
4155 tree
4156 initializer_constant_valid_p (tree value, tree endtype)
4157 {
4158 tree ret;
4159
4160 switch (TREE_CODE (value))
4161 {
4162 case CONSTRUCTOR:
4163 if (constructor_static_from_elts_p (value))
4164 {
4165 unsigned HOST_WIDE_INT idx;
4166 tree elt;
4167 bool absolute = true;
4168
4169 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
4170 {
4171 tree reloc;
4172 reloc = initializer_constant_valid_p (elt, TREE_TYPE (elt));
4173 if (!reloc)
4174 return NULL_TREE;
4175 if (reloc != null_pointer_node)
4176 absolute = false;
4177 }
4178 /* For a non-absolute relocation, there is no single
4179 variable that can be "the variable that determines the
4180 relocation." */
4181 return absolute ? null_pointer_node : error_mark_node;
4182 }
4183
4184 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE;
4185
4186 case INTEGER_CST:
4187 case VECTOR_CST:
4188 case REAL_CST:
4189 case FIXED_CST:
4190 case STRING_CST:
4191 case COMPLEX_CST:
4192 return null_pointer_node;
4193
4194 case ADDR_EXPR:
4195 case FDESC_EXPR:
4196 {
4197 tree op0 = staticp (TREE_OPERAND (value, 0));
4198 if (op0)
4199 {
4200 /* "&(*a).f" is like unto pointer arithmetic. If "a" turns out
4201 to be a constant, this is old-skool offsetof-like nonsense. */
4202 if (TREE_CODE (op0) == INDIRECT_REF
4203 && TREE_CONSTANT (TREE_OPERAND (op0, 0)))
4204 return null_pointer_node;
4205 /* Taking the address of a nested function involves a trampoline,
4206 unless we don't need or want one. */
4207 if (TREE_CODE (op0) == FUNCTION_DECL
4208 && decl_function_context (op0)
4209 && !DECL_NO_STATIC_CHAIN (op0)
4210 && !TREE_NO_TRAMPOLINE (value))
4211 return NULL_TREE;
4212 /* "&{...}" requires a temporary to hold the constructed
4213 object. */
4214 if (TREE_CODE (op0) == CONSTRUCTOR)
4215 return NULL_TREE;
4216 }
4217 return op0;
4218 }
4219
4220 case NON_LVALUE_EXPR:
4221 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
4222
4223 case VIEW_CONVERT_EXPR:
4224 {
4225 tree src = TREE_OPERAND (value, 0);
4226 tree src_type = TREE_TYPE (src);
4227 tree dest_type = TREE_TYPE (value);
4228
4229 /* Allow view-conversions from aggregate to non-aggregate type only
4230 if the bit pattern is fully preserved afterwards; otherwise, the
4231 RTL expander won't be able to apply a subsequent transformation
4232 to the underlying constructor. */
4233 if (AGGREGATE_TYPE_P (src_type) && !AGGREGATE_TYPE_P (dest_type))
4234 {
4235 if (TYPE_MODE (endtype) == TYPE_MODE (dest_type))
4236 return initializer_constant_valid_p (src, endtype);
4237 else
4238 return NULL_TREE;
4239 }
4240
4241 /* Allow all other kinds of view-conversion. */
4242 return initializer_constant_valid_p (src, endtype);
4243 }
4244
4245 CASE_CONVERT:
4246 {
4247 tree src = TREE_OPERAND (value, 0);
4248 tree src_type = TREE_TYPE (src);
4249 tree dest_type = TREE_TYPE (value);
4250
4251 /* Allow conversions between pointer types, floating-point
4252 types, and offset types. */
4253 if ((POINTER_TYPE_P (dest_type) && POINTER_TYPE_P (src_type))
4254 || (FLOAT_TYPE_P (dest_type) && FLOAT_TYPE_P (src_type))
4255 || (TREE_CODE (dest_type) == OFFSET_TYPE
4256 && TREE_CODE (src_type) == OFFSET_TYPE))
4257 return initializer_constant_valid_p (src, endtype);
4258
4259 /* Allow length-preserving conversions between integer types. */
4260 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type)
4261 && (TYPE_PRECISION (dest_type) == TYPE_PRECISION (src_type)))
4262 return initializer_constant_valid_p (src, endtype);
4263
4264 /* Allow conversions between other integer types only if
4265 explicit value. */
4266 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type))
4267 {
4268 tree inner = initializer_constant_valid_p (src, endtype);
4269 if (inner == null_pointer_node)
4270 return null_pointer_node;
4271 break;
4272 }
4273
4274 /* Allow (int) &foo provided int is as wide as a pointer. */
4275 if (INTEGRAL_TYPE_P (dest_type) && POINTER_TYPE_P (src_type)
4276 && (TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type)))
4277 return initializer_constant_valid_p (src, endtype);
4278
4279 /* Likewise conversions from int to pointers, but also allow
4280 conversions from 0. */
4281 if ((POINTER_TYPE_P (dest_type)
4282 || TREE_CODE (dest_type) == OFFSET_TYPE)
4283 && INTEGRAL_TYPE_P (src_type))
4284 {
4285 if (TREE_CODE (src) == INTEGER_CST
4286 && TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type))
4287 return null_pointer_node;
4288 if (integer_zerop (src))
4289 return null_pointer_node;
4290 else if (TYPE_PRECISION (dest_type) <= TYPE_PRECISION (src_type))
4291 return initializer_constant_valid_p (src, endtype);
4292 }
4293
4294 /* Allow conversions to struct or union types if the value
4295 inside is okay. */
4296 if (TREE_CODE (dest_type) == RECORD_TYPE
4297 || TREE_CODE (dest_type) == UNION_TYPE)
4298 return initializer_constant_valid_p (src, endtype);
4299 }
4300 break;
4301
4302 case POINTER_PLUS_EXPR:
4303 case PLUS_EXPR:
4304 if (! INTEGRAL_TYPE_P (endtype)
4305 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
4306 {
4307 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
4308 endtype);
4309 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
4310 endtype);
4311 /* If either term is absolute, use the other term's relocation. */
4312 if (valid0 == null_pointer_node)
4313 return valid1;
4314 if (valid1 == null_pointer_node)
4315 return valid0;
4316 }
4317
4318 /* Support narrowing pointer differences. */
4319 ret = narrowing_initializer_constant_valid_p (value, endtype);
4320 if (ret != NULL_TREE)
4321 return ret;
4322
4323 break;
4324
4325 case MINUS_EXPR:
4326 if (! INTEGRAL_TYPE_P (endtype)
4327 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
4328 {
4329 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
4330 endtype);
4331 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
4332 endtype);
4333 /* Win if second argument is absolute. */
4334 if (valid1 == null_pointer_node)
4335 return valid0;
4336 /* Win if both arguments have the same relocation.
4337 Then the value is absolute. */
4338 if (valid0 == valid1 && valid0 != 0)
4339 return null_pointer_node;
4340
4341 /* Since GCC guarantees that string constants are unique in the
4342 generated code, a subtraction between two copies of the same
4343 constant string is absolute. */
4344 if (valid0 && TREE_CODE (valid0) == STRING_CST
4345 && valid1 && TREE_CODE (valid1) == STRING_CST
4346 && operand_equal_p (valid0, valid1, 1))
4347 return null_pointer_node;
4348 }
4349
4350 /* Support narrowing differences. */
4351 ret = narrowing_initializer_constant_valid_p (value, endtype);
4352 if (ret != NULL_TREE)
4353 return ret;
4354
4355 break;
4356
4357 default:
4358 break;
4359 }
4360
4361 return 0;
4362 }
4363 \f
4364 /* Output assembler code for constant EXP to FILE, with no label.
4365 This includes the pseudo-op such as ".int" or ".byte", and a newline.
4366 Assumes output_addressed_constants has been done on EXP already.
4367
4368 Generate exactly SIZE bytes of assembler data, padding at the end
4369 with zeros if necessary. SIZE must always be specified.
4370
4371 SIZE is important for structure constructors,
4372 since trailing members may have been omitted from the constructor.
4373 It is also important for initialization of arrays from string constants
4374 since the full length of the string constant might not be wanted.
4375 It is also needed for initialization of unions, where the initializer's
4376 type is just one member, and that may not be as long as the union.
4377
4378 There a case in which we would fail to output exactly SIZE bytes:
4379 for a structure constructor that wants to produce more than SIZE bytes.
4380 But such constructors will never be generated for any possible input.
4381
4382 ALIGN is the alignment of the data in bits. */
4383
4384 void
4385 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
4386 {
4387 enum tree_code code;
4388 unsigned HOST_WIDE_INT thissize;
4389
4390 if (size == 0 || flag_syntax_only)
4391 return;
4392
4393 /* See if we're trying to initialize a pointer in a non-default mode
4394 to the address of some declaration somewhere. If the target says
4395 the mode is valid for pointers, assume the target has a way of
4396 resolving it. */
4397 if (TREE_CODE (exp) == NOP_EXPR
4398 && POINTER_TYPE_P (TREE_TYPE (exp))
4399 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
4400 {
4401 tree saved_type = TREE_TYPE (exp);
4402
4403 /* Peel off any intermediate conversions-to-pointer for valid
4404 pointer modes. */
4405 while (TREE_CODE (exp) == NOP_EXPR
4406 && POINTER_TYPE_P (TREE_TYPE (exp))
4407 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
4408 exp = TREE_OPERAND (exp, 0);
4409
4410 /* If what we're left with is the address of something, we can
4411 convert the address to the final type and output it that
4412 way. */
4413 if (TREE_CODE (exp) == ADDR_EXPR)
4414 exp = build1 (ADDR_EXPR, saved_type, TREE_OPERAND (exp, 0));
4415 /* Likewise for constant ints. */
4416 else if (TREE_CODE (exp) == INTEGER_CST)
4417 exp = build_int_cst_wide (saved_type, TREE_INT_CST_LOW (exp),
4418 TREE_INT_CST_HIGH (exp));
4419
4420 }
4421
4422 /* Eliminate any conversions since we'll be outputting the underlying
4423 constant. */
4424 while (CONVERT_EXPR_P (exp)
4425 || TREE_CODE (exp) == NON_LVALUE_EXPR
4426 || TREE_CODE (exp) == VIEW_CONVERT_EXPR)
4427 {
4428 HOST_WIDE_INT type_size = int_size_in_bytes (TREE_TYPE (exp));
4429 HOST_WIDE_INT op_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (exp, 0)));
4430
4431 /* Make sure eliminating the conversion is really a no-op, except with
4432 VIEW_CONVERT_EXPRs to allow for wild Ada unchecked conversions and
4433 union types to allow for Ada unchecked unions. */
4434 if (type_size > op_size
4435 && TREE_CODE (exp) != VIEW_CONVERT_EXPR
4436 && TREE_CODE (TREE_TYPE (exp)) != UNION_TYPE)
4437 /* Keep the conversion. */
4438 break;
4439 else
4440 exp = TREE_OPERAND (exp, 0);
4441 }
4442
4443 code = TREE_CODE (TREE_TYPE (exp));
4444 thissize = int_size_in_bytes (TREE_TYPE (exp));
4445
4446 /* Allow a constructor with no elements for any data type.
4447 This means to fill the space with zeros. */
4448 if (TREE_CODE (exp) == CONSTRUCTOR
4449 && VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (exp)))
4450 {
4451 assemble_zeros (size);
4452 return;
4453 }
4454
4455 if (TREE_CODE (exp) == FDESC_EXPR)
4456 {
4457 #ifdef ASM_OUTPUT_FDESC
4458 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0);
4459 tree decl = TREE_OPERAND (exp, 0);
4460 ASM_OUTPUT_FDESC (asm_out_file, decl, part);
4461 #else
4462 gcc_unreachable ();
4463 #endif
4464 return;
4465 }
4466
4467 /* Now output the underlying data. If we've handling the padding, return.
4468 Otherwise, break and ensure SIZE is the size written. */
4469 switch (code)
4470 {
4471 case BOOLEAN_TYPE:
4472 case INTEGER_TYPE:
4473 case ENUMERAL_TYPE:
4474 case POINTER_TYPE:
4475 case REFERENCE_TYPE:
4476 case OFFSET_TYPE:
4477 case FIXED_POINT_TYPE:
4478 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
4479 EXPAND_INITIALIZER),
4480 MIN (size, thissize), align, 0))
4481 error ("initializer for integer/fixed-point value is too complicated");
4482 break;
4483
4484 case REAL_TYPE:
4485 if (TREE_CODE (exp) != REAL_CST)
4486 error ("initializer for floating value is not a floating constant");
4487
4488 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
4489 break;
4490
4491 case COMPLEX_TYPE:
4492 output_constant (TREE_REALPART (exp), thissize / 2, align);
4493 output_constant (TREE_IMAGPART (exp), thissize / 2,
4494 min_align (align, BITS_PER_UNIT * (thissize / 2)));
4495 break;
4496
4497 case ARRAY_TYPE:
4498 case VECTOR_TYPE:
4499 switch (TREE_CODE (exp))
4500 {
4501 case CONSTRUCTOR:
4502 output_constructor (exp, size, align);
4503 return;
4504 case STRING_CST:
4505 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp),
4506 size);
4507 assemble_string (TREE_STRING_POINTER (exp), thissize);
4508 break;
4509
4510 case VECTOR_CST:
4511 {
4512 int elt_size;
4513 tree link;
4514 unsigned int nalign;
4515 enum machine_mode inner;
4516
4517 inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp)));
4518 nalign = MIN (align, GET_MODE_ALIGNMENT (inner));
4519
4520 elt_size = GET_MODE_SIZE (inner);
4521
4522 link = TREE_VECTOR_CST_ELTS (exp);
4523 output_constant (TREE_VALUE (link), elt_size, align);
4524 thissize = elt_size;
4525 while ((link = TREE_CHAIN (link)) != NULL)
4526 {
4527 output_constant (TREE_VALUE (link), elt_size, nalign);
4528 thissize += elt_size;
4529 }
4530 break;
4531 }
4532 default:
4533 gcc_unreachable ();
4534 }
4535 break;
4536
4537 case RECORD_TYPE:
4538 case UNION_TYPE:
4539 gcc_assert (TREE_CODE (exp) == CONSTRUCTOR);
4540 output_constructor (exp, size, align);
4541 return;
4542
4543 case ERROR_MARK:
4544 return;
4545
4546 default:
4547 gcc_unreachable ();
4548 }
4549
4550 if (size > thissize)
4551 assemble_zeros (size - thissize);
4552 }
4553
4554 \f
4555 /* Subroutine of output_constructor, used for computing the size of
4556 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array
4557 type with an unspecified upper bound. */
4558
4559 static unsigned HOST_WIDE_INT
4560 array_size_for_constructor (tree val)
4561 {
4562 tree max_index, i;
4563 unsigned HOST_WIDE_INT cnt;
4564 tree index, value, tmp;
4565
4566 /* This code used to attempt to handle string constants that are not
4567 arrays of single-bytes, but nothing else does, so there's no point in
4568 doing it here. */
4569 if (TREE_CODE (val) == STRING_CST)
4570 return TREE_STRING_LENGTH (val);
4571
4572 max_index = NULL_TREE;
4573 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (val), cnt, index, value)
4574 {
4575 if (TREE_CODE (index) == RANGE_EXPR)
4576 index = TREE_OPERAND (index, 1);
4577 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index))
4578 max_index = index;
4579 }
4580
4581 if (max_index == NULL_TREE)
4582 return 0;
4583
4584 /* Compute the total number of array elements. */
4585 tmp = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val)));
4586 i = size_binop (MINUS_EXPR, fold_convert (sizetype, max_index),
4587 fold_convert (sizetype, tmp));
4588 i = size_binop (PLUS_EXPR, i, build_int_cst (sizetype, 1));
4589
4590 /* Multiply by the array element unit size to find number of bytes. */
4591 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val))));
4592
4593 return tree_low_cst (i, 1);
4594 }
4595
4596 /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants).
4597 Generate at least SIZE bytes, padding if necessary. */
4598
4599 static void
4600 output_constructor (tree exp, unsigned HOST_WIDE_INT size,
4601 unsigned int align)
4602 {
4603 tree type = TREE_TYPE (exp);
4604 tree field = 0;
4605 tree min_index = 0;
4606 /* Number of bytes output or skipped so far.
4607 In other words, current position within the constructor. */
4608 HOST_WIDE_INT total_bytes = 0;
4609 /* Nonzero means BYTE contains part of a byte, to be output. */
4610 int byte_buffer_in_use = 0;
4611 int byte = 0;
4612 unsigned HOST_WIDE_INT cnt;
4613 constructor_elt *ce;
4614
4615 gcc_assert (HOST_BITS_PER_WIDE_INT >= BITS_PER_UNIT);
4616
4617 if (TREE_CODE (type) == RECORD_TYPE)
4618 field = TYPE_FIELDS (type);
4619
4620 if (TREE_CODE (type) == ARRAY_TYPE
4621 && TYPE_DOMAIN (type) != 0)
4622 min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
4623
4624 /* As LINK goes through the elements of the constant,
4625 FIELD goes through the structure fields, if the constant is a structure.
4626 if the constant is a union, then we override this,
4627 by getting the field from the TREE_LIST element.
4628 But the constant could also be an array. Then FIELD is zero.
4629
4630 There is always a maximum of one element in the chain LINK for unions
4631 (even if the initializer in a source program incorrectly contains
4632 more one). */
4633 for (cnt = 0;
4634 VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (exp), cnt, ce);
4635 cnt++, field = field ? TREE_CHAIN (field) : 0)
4636 {
4637 tree val = ce->value;
4638 tree index = 0;
4639
4640 /* The element in a union constructor specifies the proper field
4641 or index. */
4642 if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE
4643 || TREE_CODE (type) == QUAL_UNION_TYPE)
4644 && ce->index != 0)
4645 field = ce->index;
4646
4647 else if (TREE_CODE (type) == ARRAY_TYPE)
4648 index = ce->index;
4649
4650 #ifdef ASM_COMMENT_START
4651 if (field && flag_verbose_asm)
4652 fprintf (asm_out_file, "%s %s:\n",
4653 ASM_COMMENT_START,
4654 DECL_NAME (field)
4655 ? IDENTIFIER_POINTER (DECL_NAME (field))
4656 : "<anonymous>");
4657 #endif
4658
4659 /* Eliminate the marker that makes a cast not be an lvalue. */
4660 if (val != 0)
4661 STRIP_NOPS (val);
4662
4663 if (index && TREE_CODE (index) == RANGE_EXPR)
4664 {
4665 unsigned HOST_WIDE_INT fieldsize
4666 = int_size_in_bytes (TREE_TYPE (type));
4667 HOST_WIDE_INT lo_index = tree_low_cst (TREE_OPERAND (index, 0), 0);
4668 HOST_WIDE_INT hi_index = tree_low_cst (TREE_OPERAND (index, 1), 0);
4669 HOST_WIDE_INT index;
4670 unsigned int align2 = min_align (align, fieldsize * BITS_PER_UNIT);
4671
4672 for (index = lo_index; index <= hi_index; index++)
4673 {
4674 /* Output the element's initial value. */
4675 if (val == 0)
4676 assemble_zeros (fieldsize);
4677 else
4678 output_constant (val, fieldsize, align2);
4679
4680 /* Count its size. */
4681 total_bytes += fieldsize;
4682 }
4683 }
4684 else if (field == 0 || !DECL_BIT_FIELD (field))
4685 {
4686 /* An element that is not a bit-field. */
4687
4688 unsigned HOST_WIDE_INT fieldsize;
4689 /* Since this structure is static,
4690 we know the positions are constant. */
4691 HOST_WIDE_INT pos = field ? int_byte_position (field) : 0;
4692 unsigned int align2;
4693
4694 if (index != 0)
4695 pos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (val)), 1)
4696 * (tree_low_cst (index, 0) - tree_low_cst (min_index, 0)));
4697
4698 /* Output any buffered-up bit-fields preceding this element. */
4699 if (byte_buffer_in_use)
4700 {
4701 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4702 total_bytes++;
4703 byte_buffer_in_use = 0;
4704 }
4705
4706 /* Advance to offset of this element.
4707 Note no alignment needed in an array, since that is guaranteed
4708 if each element has the proper size. */
4709 if ((field != 0 || index != 0) && pos != total_bytes)
4710 {
4711 gcc_assert (pos >= total_bytes);
4712 assemble_zeros (pos - total_bytes);
4713 total_bytes = pos;
4714 }
4715
4716 /* Find the alignment of this element. */
4717 align2 = min_align (align, BITS_PER_UNIT * pos);
4718
4719 /* Determine size this element should occupy. */
4720 if (field)
4721 {
4722 fieldsize = 0;
4723
4724 /* If this is an array with an unspecified upper bound,
4725 the initializer determines the size. */
4726 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL,
4727 but we cannot do this until the deprecated support for
4728 initializing zero-length array members is removed. */
4729 if (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE
4730 && TYPE_DOMAIN (TREE_TYPE (field))
4731 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (field))))
4732 {
4733 fieldsize = array_size_for_constructor (val);
4734 /* Given a non-empty initialization, this field had
4735 better be last. */
4736 gcc_assert (!fieldsize || !TREE_CHAIN (field));
4737 }
4738 else if (DECL_SIZE_UNIT (field))
4739 {
4740 /* ??? This can't be right. If the decl size overflows
4741 a host integer we will silently emit no data. */
4742 if (host_integerp (DECL_SIZE_UNIT (field), 1))
4743 fieldsize = tree_low_cst (DECL_SIZE_UNIT (field), 1);
4744 }
4745 }
4746 else
4747 fieldsize = int_size_in_bytes (TREE_TYPE (type));
4748
4749 /* Output the element's initial value. */
4750 if (val == 0)
4751 assemble_zeros (fieldsize);
4752 else
4753 output_constant (val, fieldsize, align2);
4754
4755 /* Count its size. */
4756 total_bytes += fieldsize;
4757 }
4758 else if (val != 0 && TREE_CODE (val) != INTEGER_CST)
4759 error ("invalid initial value for member %qs",
4760 IDENTIFIER_POINTER (DECL_NAME (field)));
4761 else
4762 {
4763 /* Element that is a bit-field. */
4764
4765 HOST_WIDE_INT next_offset = int_bit_position (field);
4766 HOST_WIDE_INT end_offset
4767 = (next_offset + tree_low_cst (DECL_SIZE (field), 1));
4768
4769 if (val == 0)
4770 val = integer_zero_node;
4771
4772 /* If this field does not start in this (or, next) byte,
4773 skip some bytes. */
4774 if (next_offset / BITS_PER_UNIT != total_bytes)
4775 {
4776 /* Output remnant of any bit field in previous bytes. */
4777 if (byte_buffer_in_use)
4778 {
4779 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4780 total_bytes++;
4781 byte_buffer_in_use = 0;
4782 }
4783
4784 /* If still not at proper byte, advance to there. */
4785 if (next_offset / BITS_PER_UNIT != total_bytes)
4786 {
4787 gcc_assert (next_offset / BITS_PER_UNIT >= total_bytes);
4788 assemble_zeros (next_offset / BITS_PER_UNIT - total_bytes);
4789 total_bytes = next_offset / BITS_PER_UNIT;
4790 }
4791 }
4792
4793 if (! byte_buffer_in_use)
4794 byte = 0;
4795
4796 /* We must split the element into pieces that fall within
4797 separate bytes, and combine each byte with previous or
4798 following bit-fields. */
4799
4800 /* next_offset is the offset n fbits from the beginning of
4801 the structure to the next bit of this element to be processed.
4802 end_offset is the offset of the first bit past the end of
4803 this element. */
4804 while (next_offset < end_offset)
4805 {
4806 int this_time;
4807 int shift;
4808 HOST_WIDE_INT value;
4809 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
4810 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
4811
4812 /* Advance from byte to byte
4813 within this element when necessary. */
4814 while (next_byte != total_bytes)
4815 {
4816 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4817 total_bytes++;
4818 byte = 0;
4819 }
4820
4821 /* Number of bits we can process at once
4822 (all part of the same byte). */
4823 this_time = MIN (end_offset - next_offset,
4824 BITS_PER_UNIT - next_bit);
4825 if (BYTES_BIG_ENDIAN)
4826 {
4827 /* On big-endian machine, take the most significant bits
4828 first (of the bits that are significant)
4829 and put them into bytes from the most significant end. */
4830 shift = end_offset - next_offset - this_time;
4831
4832 /* Don't try to take a bunch of bits that cross
4833 the word boundary in the INTEGER_CST. We can
4834 only select bits from the LOW or HIGH part
4835 not from both. */
4836 if (shift < HOST_BITS_PER_WIDE_INT
4837 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4838 {
4839 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT;
4840 shift = HOST_BITS_PER_WIDE_INT;
4841 }
4842
4843 /* Now get the bits from the appropriate constant word. */
4844 if (shift < HOST_BITS_PER_WIDE_INT)
4845 value = TREE_INT_CST_LOW (val);
4846 else
4847 {
4848 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4849 value = TREE_INT_CST_HIGH (val);
4850 shift -= HOST_BITS_PER_WIDE_INT;
4851 }
4852
4853 /* Get the result. This works only when:
4854 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4855 byte |= (((value >> shift)
4856 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4857 << (BITS_PER_UNIT - this_time - next_bit));
4858 }
4859 else
4860 {
4861 /* On little-endian machines,
4862 take first the least significant bits of the value
4863 and pack them starting at the least significant
4864 bits of the bytes. */
4865 shift = next_offset - int_bit_position (field);
4866
4867 /* Don't try to take a bunch of bits that cross
4868 the word boundary in the INTEGER_CST. We can
4869 only select bits from the LOW or HIGH part
4870 not from both. */
4871 if (shift < HOST_BITS_PER_WIDE_INT
4872 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4873 this_time = (HOST_BITS_PER_WIDE_INT - shift);
4874
4875 /* Now get the bits from the appropriate constant word. */
4876 if (shift < HOST_BITS_PER_WIDE_INT)
4877 value = TREE_INT_CST_LOW (val);
4878 else
4879 {
4880 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4881 value = TREE_INT_CST_HIGH (val);
4882 shift -= HOST_BITS_PER_WIDE_INT;
4883 }
4884
4885 /* Get the result. This works only when:
4886 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4887 byte |= (((value >> shift)
4888 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4889 << next_bit);
4890 }
4891
4892 next_offset += this_time;
4893 byte_buffer_in_use = 1;
4894 }
4895 }
4896 }
4897
4898 if (byte_buffer_in_use)
4899 {
4900 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4901 total_bytes++;
4902 }
4903
4904 if ((unsigned HOST_WIDE_INT)total_bytes < size)
4905 assemble_zeros (size - total_bytes);
4906 }
4907
4908 /* Mark DECL as weak. */
4909
4910 static void
4911 mark_weak (tree decl)
4912 {
4913 DECL_WEAK (decl) = 1;
4914
4915 if (DECL_RTL_SET_P (decl)
4916 && MEM_P (DECL_RTL (decl))
4917 && XEXP (DECL_RTL (decl), 0)
4918 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF)
4919 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1;
4920 }
4921
4922 /* Merge weak status between NEWDECL and OLDDECL. */
4923
4924 void
4925 merge_weak (tree newdecl, tree olddecl)
4926 {
4927 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl))
4928 {
4929 if (DECL_WEAK (newdecl) && SUPPORTS_WEAK)
4930 {
4931 tree *pwd;
4932 /* We put the NEWDECL on the weak_decls list at some point
4933 and OLDDECL as well. Keep just OLDDECL on the list. */
4934 for (pwd = &weak_decls; *pwd; pwd = &TREE_CHAIN (*pwd))
4935 if (TREE_VALUE (*pwd) == newdecl)
4936 {
4937 *pwd = TREE_CHAIN (*pwd);
4938 break;
4939 }
4940 }
4941 return;
4942 }
4943
4944 if (DECL_WEAK (newdecl))
4945 {
4946 tree wd;
4947
4948 /* NEWDECL is weak, but OLDDECL is not. */
4949
4950 /* If we already output the OLDDECL, we're in trouble; we can't
4951 go back and make it weak. This error cannot be caught in
4952 declare_weak because the NEWDECL and OLDDECL was not yet
4953 been merged; therefore, TREE_ASM_WRITTEN was not set. */
4954 if (TREE_ASM_WRITTEN (olddecl))
4955 error ("weak declaration of %q+D must precede definition",
4956 newdecl);
4957
4958 /* If we've already generated rtl referencing OLDDECL, we may
4959 have done so in a way that will not function properly with
4960 a weak symbol. */
4961 else if (TREE_USED (olddecl)
4962 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl)))
4963 warning (0, "weak declaration of %q+D after first use results "
4964 "in unspecified behavior", newdecl);
4965
4966 if (SUPPORTS_WEAK)
4967 {
4968 /* We put the NEWDECL on the weak_decls list at some point.
4969 Replace it with the OLDDECL. */
4970 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd))
4971 if (TREE_VALUE (wd) == newdecl)
4972 {
4973 TREE_VALUE (wd) = olddecl;
4974 break;
4975 }
4976 /* We may not find the entry on the list. If NEWDECL is a
4977 weak alias, then we will have already called
4978 globalize_decl to remove the entry; in that case, we do
4979 not need to do anything. */
4980 }
4981
4982 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */
4983 mark_weak (olddecl);
4984 }
4985 else
4986 /* OLDDECL was weak, but NEWDECL was not explicitly marked as
4987 weak. Just update NEWDECL to indicate that it's weak too. */
4988 mark_weak (newdecl);
4989 }
4990
4991 /* Declare DECL to be a weak symbol. */
4992
4993 void
4994 declare_weak (tree decl)
4995 {
4996 if (! TREE_PUBLIC (decl))
4997 error ("weak declaration of %q+D must be public", decl);
4998 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl))
4999 error ("weak declaration of %q+D must precede definition", decl);
5000 else if (!SUPPORTS_WEAK)
5001 warning (0, "weak declaration of %q+D not supported", decl);
5002
5003 mark_weak (decl);
5004 }
5005
5006 static void
5007 weak_finish_1 (tree decl)
5008 {
5009 #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL)
5010 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5011 #endif
5012
5013 if (! TREE_USED (decl))
5014 return;
5015
5016 #ifdef ASM_WEAKEN_DECL
5017 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL);
5018 #else
5019 #ifdef ASM_WEAKEN_LABEL
5020 ASM_WEAKEN_LABEL (asm_out_file, name);
5021 #else
5022 #ifdef ASM_OUTPUT_WEAK_ALIAS
5023 {
5024 static bool warn_once = 0;
5025 if (! warn_once)
5026 {
5027 warning (0, "only weak aliases are supported in this configuration");
5028 warn_once = 1;
5029 }
5030 return;
5031 }
5032 #endif
5033 #endif
5034 #endif
5035 }
5036
5037 /* This TREE_LIST contains weakref targets. */
5038
5039 static GTY(()) tree weakref_targets;
5040
5041 /* Forward declaration. */
5042 static tree find_decl_and_mark_needed (tree decl, tree target);
5043
5044 /* Emit any pending weak declarations. */
5045
5046 void
5047 weak_finish (void)
5048 {
5049 tree t;
5050
5051 for (t = weakref_targets; t; t = TREE_CHAIN (t))
5052 {
5053 tree alias_decl = TREE_PURPOSE (t);
5054 tree target = ultimate_transparent_alias_target (&TREE_VALUE (t));
5055
5056 if (! TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (alias_decl)))
5057 /* Remove alias_decl from the weak list, but leave entries for
5058 the target alone. */
5059 target = NULL_TREE;
5060 #ifndef ASM_OUTPUT_WEAKREF
5061 else if (! TREE_SYMBOL_REFERENCED (target))
5062 {
5063 /* Use ASM_WEAKEN_LABEL only if ASM_WEAKEN_DECL is not
5064 defined, otherwise we and weak_finish_1 would use
5065 different macros. */
5066 # if defined ASM_WEAKEN_LABEL && ! defined ASM_WEAKEN_DECL
5067 ASM_WEAKEN_LABEL (asm_out_file, IDENTIFIER_POINTER (target));
5068 # else
5069 tree decl = find_decl_and_mark_needed (alias_decl, target);
5070
5071 if (! decl)
5072 {
5073 decl = build_decl (TREE_CODE (alias_decl), target,
5074 TREE_TYPE (alias_decl));
5075
5076 DECL_EXTERNAL (decl) = 1;
5077 TREE_PUBLIC (decl) = 1;
5078 DECL_ARTIFICIAL (decl) = 1;
5079 TREE_NOTHROW (decl) = TREE_NOTHROW (alias_decl);
5080 TREE_USED (decl) = 1;
5081 }
5082
5083 weak_finish_1 (decl);
5084 # endif
5085 }
5086 #endif
5087
5088 {
5089 tree *p;
5090 tree t2;
5091
5092 /* Remove the alias and the target from the pending weak list
5093 so that we do not emit any .weak directives for the former,
5094 nor multiple .weak directives for the latter. */
5095 for (p = &weak_decls; (t2 = *p) ; )
5096 {
5097 if (TREE_VALUE (t2) == alias_decl
5098 || target == DECL_ASSEMBLER_NAME (TREE_VALUE (t2)))
5099 *p = TREE_CHAIN (t2);
5100 else
5101 p = &TREE_CHAIN (t2);
5102 }
5103
5104 /* Remove other weakrefs to the same target, to speed things up. */
5105 for (p = &TREE_CHAIN (t); (t2 = *p) ; )
5106 {
5107 if (target == ultimate_transparent_alias_target (&TREE_VALUE (t2)))
5108 *p = TREE_CHAIN (t2);
5109 else
5110 p = &TREE_CHAIN (t2);
5111 }
5112 }
5113 }
5114
5115 for (t = weak_decls; t; t = TREE_CHAIN (t))
5116 {
5117 tree decl = TREE_VALUE (t);
5118
5119 weak_finish_1 (decl);
5120 }
5121 }
5122
5123 /* Emit the assembly bits to indicate that DECL is globally visible. */
5124
5125 static void
5126 globalize_decl (tree decl)
5127 {
5128
5129 #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL)
5130 if (DECL_WEAK (decl))
5131 {
5132 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
5133 tree *p, t;
5134
5135 #ifdef ASM_WEAKEN_DECL
5136 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
5137 #else
5138 ASM_WEAKEN_LABEL (asm_out_file, name);
5139 #endif
5140
5141 /* Remove this function from the pending weak list so that
5142 we do not emit multiple .weak directives for it. */
5143 for (p = &weak_decls; (t = *p) ; )
5144 {
5145 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5146 *p = TREE_CHAIN (t);
5147 else
5148 p = &TREE_CHAIN (t);
5149 }
5150
5151 /* Remove weakrefs to the same target from the pending weakref
5152 list, for the same reason. */
5153 for (p = &weakref_targets; (t = *p) ; )
5154 {
5155 if (DECL_ASSEMBLER_NAME (decl)
5156 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5157 *p = TREE_CHAIN (t);
5158 else
5159 p = &TREE_CHAIN (t);
5160 }
5161
5162 return;
5163 }
5164 #endif
5165
5166 targetm.asm_out.globalize_decl_name (asm_out_file, decl);
5167 }
5168
5169 /* We have to be able to tell cgraph about the needed-ness of the target
5170 of an alias. This requires that the decl have been defined. Aliases
5171 that precede their definition have to be queued for later processing. */
5172
5173 typedef struct alias_pair GTY(())
5174 {
5175 tree decl;
5176 tree target;
5177 } alias_pair;
5178
5179 /* Define gc'd vector type. */
5180 DEF_VEC_O(alias_pair);
5181 DEF_VEC_ALLOC_O(alias_pair,gc);
5182
5183 static GTY(()) VEC(alias_pair,gc) *alias_pairs;
5184
5185 /* Given an assembly name, find the decl it is associated with. At the
5186 same time, mark it needed for cgraph. */
5187
5188 static tree
5189 find_decl_and_mark_needed (tree decl, tree target)
5190 {
5191 struct cgraph_node *fnode = NULL;
5192 struct varpool_node *vnode = NULL;
5193
5194 if (TREE_CODE (decl) == FUNCTION_DECL)
5195 {
5196 fnode = cgraph_node_for_asm (target);
5197 if (fnode == NULL)
5198 vnode = varpool_node_for_asm (target);
5199 }
5200 else
5201 {
5202 vnode = varpool_node_for_asm (target);
5203 if (vnode == NULL)
5204 fnode = cgraph_node_for_asm (target);
5205 }
5206
5207 if (fnode)
5208 {
5209 /* We can't mark function nodes as used after cgraph global info
5210 is finished. This wouldn't generally be necessary, but C++
5211 virtual table thunks are introduced late in the game and
5212 might seem like they need marking, although in fact they
5213 don't. */
5214 if (! cgraph_global_info_ready)
5215 cgraph_mark_needed_node (fnode);
5216 return fnode->decl;
5217 }
5218 else if (vnode)
5219 {
5220 varpool_mark_needed_node (vnode);
5221 return vnode->decl;
5222 }
5223 else
5224 return NULL_TREE;
5225 }
5226
5227 /* Output the assembler code for a define (equate) using ASM_OUTPUT_DEF
5228 or ASM_OUTPUT_DEF_FROM_DECLS. The function defines the symbol whose
5229 tree node is DECL to have the value of the tree node TARGET. */
5230
5231 static void
5232 do_assemble_alias (tree decl, tree target)
5233 {
5234 if (TREE_ASM_WRITTEN (decl))
5235 return;
5236
5237 TREE_ASM_WRITTEN (decl) = 1;
5238 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;
5239
5240 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5241 {
5242 ultimate_transparent_alias_target (&target);
5243
5244 if (!targetm.have_tls
5245 && TREE_CODE (decl) == VAR_DECL
5246 && DECL_THREAD_LOCAL_P (decl))
5247 {
5248 decl = emutls_decl (decl);
5249 target = get_emutls_object_name (target);
5250 }
5251
5252 if (!TREE_SYMBOL_REFERENCED (target))
5253 weakref_targets = tree_cons (decl, target, weakref_targets);
5254
5255 #ifdef ASM_OUTPUT_WEAKREF
5256 ASM_OUTPUT_WEAKREF (asm_out_file, decl,
5257 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5258 IDENTIFIER_POINTER (target));
5259 #else
5260 if (!SUPPORTS_WEAK)
5261 {
5262 error ("%Jweakref is not supported in this configuration", decl);
5263 return;
5264 }
5265 #endif
5266 return;
5267 }
5268
5269 if (!targetm.have_tls
5270 && TREE_CODE (decl) == VAR_DECL
5271 && DECL_THREAD_LOCAL_P (decl))
5272 {
5273 decl = emutls_decl (decl);
5274 target = get_emutls_object_name (target);
5275 }
5276
5277 #ifdef ASM_OUTPUT_DEF
5278 /* Make name accessible from other files, if appropriate. */
5279
5280 if (TREE_PUBLIC (decl))
5281 {
5282 globalize_decl (decl);
5283 maybe_assemble_visibility (decl);
5284 }
5285
5286 # ifdef ASM_OUTPUT_DEF_FROM_DECLS
5287 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target);
5288 # else
5289 ASM_OUTPUT_DEF (asm_out_file,
5290 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5291 IDENTIFIER_POINTER (target));
5292 # endif
5293 #elif defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
5294 {
5295 const char *name;
5296 tree *p, t;
5297
5298 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5299 # ifdef ASM_WEAKEN_DECL
5300 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target));
5301 # else
5302 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
5303 # endif
5304 /* Remove this function from the pending weak list so that
5305 we do not emit multiple .weak directives for it. */
5306 for (p = &weak_decls; (t = *p) ; )
5307 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5308 *p = TREE_CHAIN (t);
5309 else
5310 p = &TREE_CHAIN (t);
5311
5312 /* Remove weakrefs to the same target from the pending weakref
5313 list, for the same reason. */
5314 for (p = &weakref_targets; (t = *p) ; )
5315 {
5316 if (DECL_ASSEMBLER_NAME (decl)
5317 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5318 *p = TREE_CHAIN (t);
5319 else
5320 p = &TREE_CHAIN (t);
5321 }
5322 }
5323 #endif
5324 }
5325
5326 /* First pass of completing pending aliases. Make sure that cgraph knows
5327 which symbols will be required. */
5328
5329 void
5330 finish_aliases_1 (void)
5331 {
5332 unsigned i;
5333 alias_pair *p;
5334
5335 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
5336 {
5337 tree target_decl;
5338
5339 target_decl = find_decl_and_mark_needed (p->decl, p->target);
5340 if (target_decl == NULL)
5341 {
5342 if (! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5343 error ("%q+D aliased to undefined symbol %qs",
5344 p->decl, IDENTIFIER_POINTER (p->target));
5345 }
5346 else if (DECL_EXTERNAL (target_decl)
5347 && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5348 error ("%q+D aliased to external symbol %qs",
5349 p->decl, IDENTIFIER_POINTER (p->target));
5350 }
5351 }
5352
5353 /* Second pass of completing pending aliases. Emit the actual assembly.
5354 This happens at the end of compilation and thus it is assured that the
5355 target symbol has been emitted. */
5356
5357 void
5358 finish_aliases_2 (void)
5359 {
5360 unsigned i;
5361 alias_pair *p;
5362
5363 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
5364 do_assemble_alias (p->decl, p->target);
5365
5366 VEC_truncate (alias_pair, alias_pairs, 0);
5367 }
5368
5369 /* Emit an assembler directive to make the symbol for DECL an alias to
5370 the symbol for TARGET. */
5371
5372 void
5373 assemble_alias (tree decl, tree target)
5374 {
5375 tree target_decl;
5376 bool is_weakref = false;
5377
5378 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5379 {
5380 tree alias = DECL_ASSEMBLER_NAME (decl);
5381
5382 is_weakref = true;
5383
5384 ultimate_transparent_alias_target (&target);
5385
5386 if (alias == target)
5387 error ("weakref %q+D ultimately targets itself", decl);
5388 else
5389 {
5390 #ifndef ASM_OUTPUT_WEAKREF
5391 IDENTIFIER_TRANSPARENT_ALIAS (alias) = 1;
5392 TREE_CHAIN (alias) = target;
5393 #endif
5394 }
5395 if (TREE_PUBLIC (decl))
5396 error ("weakref %q+D must have static linkage", decl);
5397 }
5398 else
5399 {
5400 #if !defined (ASM_OUTPUT_DEF)
5401 # if !defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL)
5402 error ("%Jalias definitions not supported in this configuration", decl);
5403 return;
5404 # else
5405 if (!DECL_WEAK (decl))
5406 {
5407 error ("%Jonly weak aliases are supported in this configuration", decl);
5408 return;
5409 }
5410 # endif
5411 #endif
5412 }
5413
5414 /* We must force creation of DECL_RTL for debug info generation, even though
5415 we don't use it here. */
5416 make_decl_rtl (decl);
5417 TREE_USED (decl) = 1;
5418
5419 /* A quirk of the initial implementation of aliases required that the user
5420 add "extern" to all of them. Which is silly, but now historical. Do
5421 note that the symbol is in fact locally defined. */
5422 if (! is_weakref)
5423 DECL_EXTERNAL (decl) = 0;
5424
5425 /* Allow aliases to aliases. */
5426 if (TREE_CODE (decl) == FUNCTION_DECL)
5427 cgraph_node (decl)->alias = true;
5428 else
5429 varpool_node (decl)->alias = true;
5430
5431 /* If the target has already been emitted, we don't have to queue the
5432 alias. This saves a tad of memory. */
5433 if (cgraph_global_info_ready)
5434 target_decl = find_decl_and_mark_needed (decl, target);
5435 else
5436 target_decl= NULL;
5437 if (target_decl && TREE_ASM_WRITTEN (target_decl))
5438 do_assemble_alias (decl, target);
5439 else
5440 {
5441 alias_pair *p = VEC_safe_push (alias_pair, gc, alias_pairs, NULL);
5442 p->decl = decl;
5443 p->target = target;
5444 }
5445 }
5446
5447 /* Emit an assembler directive to set symbol for DECL visibility to
5448 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */
5449
5450 void
5451 default_assemble_visibility (tree decl, int vis)
5452 {
5453 static const char * const visibility_types[] = {
5454 NULL, "protected", "hidden", "internal"
5455 };
5456
5457 const char *name, *type;
5458
5459 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5460 type = visibility_types[vis];
5461
5462 #ifdef HAVE_GAS_HIDDEN
5463 fprintf (asm_out_file, "\t.%s\t", type);
5464 assemble_name (asm_out_file, name);
5465 fprintf (asm_out_file, "\n");
5466 #else
5467 warning (OPT_Wattributes, "visibility attribute not supported "
5468 "in this configuration; ignored");
5469 #endif
5470 }
5471
5472 /* A helper function to call assemble_visibility when needed for a decl. */
5473
5474 int
5475 maybe_assemble_visibility (tree decl)
5476 {
5477 enum symbol_visibility vis = DECL_VISIBILITY (decl);
5478
5479 if (vis != VISIBILITY_DEFAULT)
5480 {
5481 targetm.asm_out.visibility (decl, vis);
5482 return 1;
5483 }
5484 else
5485 return 0;
5486 }
5487
5488 /* Returns 1 if the target configuration supports defining public symbols
5489 so that one of them will be chosen at link time instead of generating a
5490 multiply-defined symbol error, whether through the use of weak symbols or
5491 a target-specific mechanism for having duplicates discarded. */
5492
5493 int
5494 supports_one_only (void)
5495 {
5496 if (SUPPORTS_ONE_ONLY)
5497 return 1;
5498 return SUPPORTS_WEAK;
5499 }
5500
5501 /* Set up DECL as a public symbol that can be defined in multiple
5502 translation units without generating a linker error. */
5503
5504 void
5505 make_decl_one_only (tree decl)
5506 {
5507 gcc_assert (TREE_CODE (decl) == VAR_DECL
5508 || TREE_CODE (decl) == FUNCTION_DECL);
5509
5510 TREE_PUBLIC (decl) = 1;
5511
5512 if (SUPPORTS_ONE_ONLY)
5513 {
5514 #ifdef MAKE_DECL_ONE_ONLY
5515 MAKE_DECL_ONE_ONLY (decl);
5516 #endif
5517 DECL_ONE_ONLY (decl) = 1;
5518 }
5519 else if (TREE_CODE (decl) == VAR_DECL
5520 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
5521 DECL_COMMON (decl) = 1;
5522 else
5523 {
5524 gcc_assert (SUPPORTS_WEAK);
5525 DECL_WEAK (decl) = 1;
5526 }
5527 }
5528
5529 void
5530 init_varasm_once (void)
5531 {
5532 section_htab = htab_create_ggc (31, section_entry_hash,
5533 section_entry_eq, NULL);
5534 object_block_htab = htab_create_ggc (31, object_block_entry_hash,
5535 object_block_entry_eq, NULL);
5536 const_desc_htab = htab_create_ggc (1009, const_desc_hash,
5537 const_desc_eq, NULL);
5538
5539 const_alias_set = new_alias_set ();
5540 shared_constant_pool = create_constant_pool ();
5541
5542 #ifdef TEXT_SECTION_ASM_OP
5543 text_section = get_unnamed_section (SECTION_CODE, output_section_asm_op,
5544 TEXT_SECTION_ASM_OP);
5545 #endif
5546
5547 #ifdef DATA_SECTION_ASM_OP
5548 data_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5549 DATA_SECTION_ASM_OP);
5550 #endif
5551
5552 #ifdef SDATA_SECTION_ASM_OP
5553 sdata_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5554 SDATA_SECTION_ASM_OP);
5555 #endif
5556
5557 #ifdef READONLY_DATA_SECTION_ASM_OP
5558 readonly_data_section = get_unnamed_section (0, output_section_asm_op,
5559 READONLY_DATA_SECTION_ASM_OP);
5560 #endif
5561
5562 #ifdef CTORS_SECTION_ASM_OP
5563 ctors_section = get_unnamed_section (0, output_section_asm_op,
5564 CTORS_SECTION_ASM_OP);
5565 #endif
5566
5567 #ifdef DTORS_SECTION_ASM_OP
5568 dtors_section = get_unnamed_section (0, output_section_asm_op,
5569 DTORS_SECTION_ASM_OP);
5570 #endif
5571
5572 #ifdef BSS_SECTION_ASM_OP
5573 bss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5574 output_section_asm_op,
5575 BSS_SECTION_ASM_OP);
5576 #endif
5577
5578 #ifdef SBSS_SECTION_ASM_OP
5579 sbss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5580 output_section_asm_op,
5581 SBSS_SECTION_ASM_OP);
5582 #endif
5583
5584 tls_comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5585 | SECTION_COMMON, emit_tls_common);
5586 lcomm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5587 | SECTION_COMMON, emit_local);
5588 comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5589 | SECTION_COMMON, emit_common);
5590
5591 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
5592 bss_noswitch_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS,
5593 emit_bss);
5594 #endif
5595
5596 targetm.asm_out.init_sections ();
5597
5598 if (readonly_data_section == NULL)
5599 readonly_data_section = text_section;
5600 }
5601
5602 enum tls_model
5603 decl_default_tls_model (const_tree decl)
5604 {
5605 enum tls_model kind;
5606 bool is_local;
5607
5608 is_local = targetm.binds_local_p (decl);
5609 if (!flag_shlib)
5610 {
5611 if (is_local)
5612 kind = TLS_MODEL_LOCAL_EXEC;
5613 else
5614 kind = TLS_MODEL_INITIAL_EXEC;
5615 }
5616
5617 /* Local dynamic is inefficient when we're not combining the
5618 parts of the address. */
5619 else if (optimize && is_local)
5620 kind = TLS_MODEL_LOCAL_DYNAMIC;
5621 else
5622 kind = TLS_MODEL_GLOBAL_DYNAMIC;
5623 if (kind < flag_tls_default)
5624 kind = flag_tls_default;
5625
5626 return kind;
5627 }
5628
5629 /* Select a set of attributes for section NAME based on the properties
5630 of DECL and whether or not RELOC indicates that DECL's initializer
5631 might contain runtime relocations.
5632
5633 We make the section read-only and executable for a function decl,
5634 read-only for a const data decl, and writable for a non-const data decl. */
5635
5636 unsigned int
5637 default_section_type_flags (tree decl, const char *name, int reloc)
5638 {
5639 unsigned int flags;
5640
5641 if (decl && TREE_CODE (decl) == FUNCTION_DECL)
5642 flags = SECTION_CODE;
5643 else if (decl && decl_readonly_section (decl, reloc))
5644 flags = 0;
5645 else if (current_function_decl
5646 && cfun
5647 && crtl->subsections.unlikely_text_section_name
5648 && strcmp (name, crtl->subsections.unlikely_text_section_name) == 0)
5649 flags = SECTION_CODE;
5650 else if (!decl
5651 && (!current_function_decl || !cfun)
5652 && strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
5653 flags = SECTION_CODE;
5654 else
5655 flags = SECTION_WRITE;
5656
5657 if (decl && DECL_ONE_ONLY (decl))
5658 flags |= SECTION_LINKONCE;
5659
5660 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
5661 flags |= SECTION_TLS | SECTION_WRITE;
5662
5663 if (strcmp (name, ".bss") == 0
5664 || strncmp (name, ".bss.", 5) == 0
5665 || strncmp (name, ".gnu.linkonce.b.", 16) == 0
5666 || strcmp (name, ".sbss") == 0
5667 || strncmp (name, ".sbss.", 6) == 0
5668 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0)
5669 flags |= SECTION_BSS;
5670
5671 if (strcmp (name, ".tdata") == 0
5672 || strncmp (name, ".tdata.", 7) == 0
5673 || strncmp (name, ".gnu.linkonce.td.", 17) == 0)
5674 flags |= SECTION_TLS;
5675
5676 if (strcmp (name, ".tbss") == 0
5677 || strncmp (name, ".tbss.", 6) == 0
5678 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
5679 flags |= SECTION_TLS | SECTION_BSS;
5680
5681 /* These three sections have special ELF types. They are neither
5682 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't
5683 want to print a section type (@progbits or @nobits). If someone
5684 is silly enough to emit code or TLS variables to one of these
5685 sections, then don't handle them specially. */
5686 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS))
5687 && (strcmp (name, ".init_array") == 0
5688 || strcmp (name, ".fini_array") == 0
5689 || strcmp (name, ".preinit_array") == 0))
5690 flags |= SECTION_NOTYPE;
5691
5692 return flags;
5693 }
5694
5695 /* Return true if the target supports some form of global BSS,
5696 either through bss_noswitch_section, or by selecting a BSS
5697 section in TARGET_ASM_SELECT_SECTION. */
5698
5699 bool
5700 have_global_bss_p (void)
5701 {
5702 return bss_noswitch_section || targetm.have_switchable_bss_sections;
5703 }
5704
5705 /* Output assembly to switch to section NAME with attribute FLAGS.
5706 Four variants for common object file formats. */
5707
5708 void
5709 default_no_named_section (const char *name ATTRIBUTE_UNUSED,
5710 unsigned int flags ATTRIBUTE_UNUSED,
5711 tree decl ATTRIBUTE_UNUSED)
5712 {
5713 /* Some object formats don't support named sections at all. The
5714 front-end should already have flagged this as an error. */
5715 gcc_unreachable ();
5716 }
5717
5718 void
5719 default_elf_asm_named_section (const char *name, unsigned int flags,
5720 tree decl ATTRIBUTE_UNUSED)
5721 {
5722 char flagchars[10], *f = flagchars;
5723
5724 /* If we have already declared this section, we can use an
5725 abbreviated form to switch back to it -- unless this section is
5726 part of a COMDAT groups, in which case GAS requires the full
5727 declaration every time. */
5728 if (!(HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5729 && (flags & SECTION_DECLARED))
5730 {
5731 fprintf (asm_out_file, "\t.section\t%s\n", name);
5732 return;
5733 }
5734
5735 if (!(flags & SECTION_DEBUG))
5736 *f++ = 'a';
5737 if (flags & SECTION_WRITE)
5738 *f++ = 'w';
5739 if (flags & SECTION_CODE)
5740 *f++ = 'x';
5741 if (flags & SECTION_SMALL)
5742 *f++ = 's';
5743 if (flags & SECTION_MERGE)
5744 *f++ = 'M';
5745 if (flags & SECTION_STRINGS)
5746 *f++ = 'S';
5747 if (flags & SECTION_TLS)
5748 *f++ = 'T';
5749 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5750 *f++ = 'G';
5751 *f = '\0';
5752
5753 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);
5754
5755 if (!(flags & SECTION_NOTYPE))
5756 {
5757 const char *type;
5758 const char *format;
5759
5760 if (flags & SECTION_BSS)
5761 type = "nobits";
5762 else
5763 type = "progbits";
5764
5765 format = ",@%s";
5766 #ifdef ASM_COMMENT_START
5767 /* On platforms that use "@" as the assembly comment character,
5768 use "%" instead. */
5769 if (strcmp (ASM_COMMENT_START, "@") == 0)
5770 format = ",%%%s";
5771 #endif
5772 fprintf (asm_out_file, format, type);
5773
5774 if (flags & SECTION_ENTSIZE)
5775 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
5776 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5777 fprintf (asm_out_file, ",%s,comdat",
5778 lang_hooks.decls.comdat_group (decl));
5779 }
5780
5781 putc ('\n', asm_out_file);
5782 }
5783
5784 void
5785 default_coff_asm_named_section (const char *name, unsigned int flags,
5786 tree decl ATTRIBUTE_UNUSED)
5787 {
5788 char flagchars[8], *f = flagchars;
5789
5790 if (flags & SECTION_WRITE)
5791 *f++ = 'w';
5792 if (flags & SECTION_CODE)
5793 *f++ = 'x';
5794 *f = '\0';
5795
5796 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);
5797 }
5798
5799 void
5800 default_pe_asm_named_section (const char *name, unsigned int flags,
5801 tree decl)
5802 {
5803 default_coff_asm_named_section (name, flags, decl);
5804
5805 if (flags & SECTION_LINKONCE)
5806 {
5807 /* Functions may have been compiled at various levels of
5808 optimization so we can't use `same_size' here.
5809 Instead, have the linker pick one. */
5810 fprintf (asm_out_file, "\t.linkonce %s\n",
5811 (flags & SECTION_CODE ? "discard" : "same_size"));
5812 }
5813 }
5814 \f
5815 /* The lame default section selector. */
5816
5817 section *
5818 default_select_section (tree decl, int reloc,
5819 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
5820 {
5821 if (DECL_P (decl))
5822 {
5823 if (decl_readonly_section (decl, reloc))
5824 return readonly_data_section;
5825 }
5826 else if (TREE_CODE (decl) == CONSTRUCTOR)
5827 {
5828 if (! ((flag_pic && reloc)
5829 || !TREE_READONLY (decl)
5830 || TREE_SIDE_EFFECTS (decl)
5831 || !TREE_CONSTANT (decl)))
5832 return readonly_data_section;
5833 }
5834 else if (TREE_CODE (decl) == STRING_CST)
5835 return readonly_data_section;
5836 else if (! (flag_pic && reloc))
5837 return readonly_data_section;
5838
5839 return data_section;
5840 }
5841
5842 enum section_category
5843 categorize_decl_for_section (const_tree decl, int reloc)
5844 {
5845 enum section_category ret;
5846
5847 if (TREE_CODE (decl) == FUNCTION_DECL)
5848 return SECCAT_TEXT;
5849 else if (TREE_CODE (decl) == STRING_CST)
5850 {
5851 if (flag_mudflap) /* or !flag_merge_constants */
5852 return SECCAT_RODATA;
5853 else
5854 return SECCAT_RODATA_MERGE_STR;
5855 }
5856 else if (TREE_CODE (decl) == VAR_DECL)
5857 {
5858 if (bss_initializer_p (decl))
5859 ret = SECCAT_BSS;
5860 else if (! TREE_READONLY (decl)
5861 || TREE_SIDE_EFFECTS (decl)
5862 || ! TREE_CONSTANT (DECL_INITIAL (decl)))
5863 {
5864 /* Here the reloc_rw_mask is not testing whether the section should
5865 be read-only or not, but whether the dynamic link will have to
5866 do something. If so, we wish to segregate the data in order to
5867 minimize cache misses inside the dynamic linker. */
5868 if (reloc & targetm.asm_out.reloc_rw_mask ())
5869 ret = reloc == 1 ? SECCAT_DATA_REL_LOCAL : SECCAT_DATA_REL;
5870 else
5871 ret = SECCAT_DATA;
5872 }
5873 else if (reloc & targetm.asm_out.reloc_rw_mask ())
5874 ret = reloc == 1 ? SECCAT_DATA_REL_RO_LOCAL : SECCAT_DATA_REL_RO;
5875 else if (reloc || flag_merge_constants < 2)
5876 /* C and C++ don't allow different variables to share the same
5877 location. -fmerge-all-constants allows even that (at the
5878 expense of not conforming). */
5879 ret = SECCAT_RODATA;
5880 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST)
5881 ret = SECCAT_RODATA_MERGE_STR_INIT;
5882 else
5883 ret = SECCAT_RODATA_MERGE_CONST;
5884 }
5885 else if (TREE_CODE (decl) == CONSTRUCTOR)
5886 {
5887 if ((reloc & targetm.asm_out.reloc_rw_mask ())
5888 || TREE_SIDE_EFFECTS (decl)
5889 || ! TREE_CONSTANT (decl))
5890 ret = SECCAT_DATA;
5891 else
5892 ret = SECCAT_RODATA;
5893 }
5894 else
5895 ret = SECCAT_RODATA;
5896
5897 /* There are no read-only thread-local sections. */
5898 if (TREE_CODE (decl) == VAR_DECL && DECL_TLS_MODEL (decl))
5899 {
5900 if (DECL_TLS_MODEL (decl) == TLS_MODEL_EMULATED)
5901 {
5902 if (DECL_EMUTLS_VAR_P (decl))
5903 {
5904 if (targetm.emutls.var_section)
5905 ret = SECCAT_EMUTLS_VAR;
5906 }
5907 else
5908 {
5909 if (targetm.emutls.tmpl_prefix)
5910 ret = SECCAT_EMUTLS_TMPL;
5911 }
5912 }
5913 /* Note that this would be *just* SECCAT_BSS, except that there's
5914 no concept of a read-only thread-local-data section. */
5915 else if (ret == SECCAT_BSS
5916 || (flag_zero_initialized_in_bss
5917 && initializer_zerop (DECL_INITIAL (decl))))
5918 ret = SECCAT_TBSS;
5919 else
5920 ret = SECCAT_TDATA;
5921 }
5922
5923 /* If the target uses small data sections, select it. */
5924 else if (targetm.in_small_data_p (decl))
5925 {
5926 if (ret == SECCAT_BSS)
5927 ret = SECCAT_SBSS;
5928 else if (targetm.have_srodata_section && ret == SECCAT_RODATA)
5929 ret = SECCAT_SRODATA;
5930 else
5931 ret = SECCAT_SDATA;
5932 }
5933
5934 return ret;
5935 }
5936
5937 bool
5938 decl_readonly_section (const_tree decl, int reloc)
5939 {
5940 switch (categorize_decl_for_section (decl, reloc))
5941 {
5942 case SECCAT_RODATA:
5943 case SECCAT_RODATA_MERGE_STR:
5944 case SECCAT_RODATA_MERGE_STR_INIT:
5945 case SECCAT_RODATA_MERGE_CONST:
5946 case SECCAT_SRODATA:
5947 return true;
5948 break;
5949 default:
5950 return false;
5951 break;
5952 }
5953 }
5954
5955 /* Select a section based on the above categorization. */
5956
5957 section *
5958 default_elf_select_section (tree decl, int reloc,
5959 unsigned HOST_WIDE_INT align)
5960 {
5961 const char *sname;
5962 switch (categorize_decl_for_section (decl, reloc))
5963 {
5964 case SECCAT_TEXT:
5965 /* We're not supposed to be called on FUNCTION_DECLs. */
5966 gcc_unreachable ();
5967 case SECCAT_RODATA:
5968 return readonly_data_section;
5969 case SECCAT_RODATA_MERGE_STR:
5970 return mergeable_string_section (decl, align, 0);
5971 case SECCAT_RODATA_MERGE_STR_INIT:
5972 return mergeable_string_section (DECL_INITIAL (decl), align, 0);
5973 case SECCAT_RODATA_MERGE_CONST:
5974 return mergeable_constant_section (DECL_MODE (decl), align, 0);
5975 case SECCAT_SRODATA:
5976 sname = ".sdata2";
5977 break;
5978 case SECCAT_DATA:
5979 return data_section;
5980 case SECCAT_DATA_REL:
5981 sname = ".data.rel";
5982 break;
5983 case SECCAT_DATA_REL_LOCAL:
5984 sname = ".data.rel.local";
5985 break;
5986 case SECCAT_DATA_REL_RO:
5987 sname = ".data.rel.ro";
5988 break;
5989 case SECCAT_DATA_REL_RO_LOCAL:
5990 sname = ".data.rel.ro.local";
5991 break;
5992 case SECCAT_SDATA:
5993 sname = ".sdata";
5994 break;
5995 case SECCAT_TDATA:
5996 sname = ".tdata";
5997 break;
5998 case SECCAT_BSS:
5999 if (bss_section)
6000 return bss_section;
6001 sname = ".bss";
6002 break;
6003 case SECCAT_SBSS:
6004 sname = ".sbss";
6005 break;
6006 case SECCAT_TBSS:
6007 sname = ".tbss";
6008 break;
6009 case SECCAT_EMUTLS_VAR:
6010 sname = targetm.emutls.var_section;
6011 break;
6012 case SECCAT_EMUTLS_TMPL:
6013 sname = targetm.emutls.tmpl_section;
6014 break;
6015 default:
6016 gcc_unreachable ();
6017 }
6018
6019 if (!DECL_P (decl))
6020 decl = NULL_TREE;
6021 return get_named_section (decl, sname, reloc);
6022 }
6023
6024 /* Construct a unique section name based on the decl name and the
6025 categorization performed above. */
6026
6027 void
6028 default_unique_section (tree decl, int reloc)
6029 {
6030 /* We only need to use .gnu.linkonce if we don't have COMDAT groups. */
6031 bool one_only = DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP;
6032 const char *prefix, *name, *linkonce;
6033 char *string;
6034
6035 switch (categorize_decl_for_section (decl, reloc))
6036 {
6037 case SECCAT_TEXT:
6038 prefix = one_only ? ".t" : ".text";
6039 break;
6040 case SECCAT_RODATA:
6041 case SECCAT_RODATA_MERGE_STR:
6042 case SECCAT_RODATA_MERGE_STR_INIT:
6043 case SECCAT_RODATA_MERGE_CONST:
6044 prefix = one_only ? ".r" : ".rodata";
6045 break;
6046 case SECCAT_SRODATA:
6047 prefix = one_only ? ".s2" : ".sdata2";
6048 break;
6049 case SECCAT_DATA:
6050 prefix = one_only ? ".d" : ".data";
6051 break;
6052 case SECCAT_DATA_REL:
6053 prefix = one_only ? ".d.rel" : ".data.rel";
6054 break;
6055 case SECCAT_DATA_REL_LOCAL:
6056 prefix = one_only ? ".d.rel.local" : ".data.rel.local";
6057 break;
6058 case SECCAT_DATA_REL_RO:
6059 prefix = one_only ? ".d.rel.ro" : ".data.rel.ro";
6060 break;
6061 case SECCAT_DATA_REL_RO_LOCAL:
6062 prefix = one_only ? ".d.rel.ro.local" : ".data.rel.ro.local";
6063 break;
6064 case SECCAT_SDATA:
6065 prefix = one_only ? ".s" : ".sdata";
6066 break;
6067 case SECCAT_BSS:
6068 prefix = one_only ? ".b" : ".bss";
6069 break;
6070 case SECCAT_SBSS:
6071 prefix = one_only ? ".sb" : ".sbss";
6072 break;
6073 case SECCAT_TDATA:
6074 prefix = one_only ? ".td" : ".tdata";
6075 break;
6076 case SECCAT_TBSS:
6077 prefix = one_only ? ".tb" : ".tbss";
6078 break;
6079 case SECCAT_EMUTLS_VAR:
6080 prefix = targetm.emutls.var_section;
6081 break;
6082 case SECCAT_EMUTLS_TMPL:
6083 prefix = targetm.emutls.tmpl_section;
6084 break;
6085 default:
6086 gcc_unreachable ();
6087 }
6088
6089 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
6090 name = targetm.strip_name_encoding (name);
6091
6092 /* If we're using one_only, then there needs to be a .gnu.linkonce
6093 prefix to the section name. */
6094 linkonce = one_only ? ".gnu.linkonce" : "";
6095
6096 string = ACONCAT ((linkonce, prefix, ".", name, NULL));
6097
6098 DECL_SECTION_NAME (decl) = build_string (strlen (string), string);
6099 }
6100
6101 /* Like compute_reloc_for_constant, except for an RTX. The return value
6102 is a mask for which bit 1 indicates a global relocation, and bit 0
6103 indicates a local relocation. */
6104
6105 static int
6106 compute_reloc_for_rtx_1 (rtx *xp, void *data)
6107 {
6108 int *preloc = (int *) data;
6109 rtx x = *xp;
6110
6111 switch (GET_CODE (x))
6112 {
6113 case SYMBOL_REF:
6114 *preloc |= SYMBOL_REF_LOCAL_P (x) ? 1 : 2;
6115 break;
6116 case LABEL_REF:
6117 *preloc |= 1;
6118 break;
6119 default:
6120 break;
6121 }
6122
6123 return 0;
6124 }
6125
6126 static int
6127 compute_reloc_for_rtx (rtx x)
6128 {
6129 int reloc;
6130
6131 switch (GET_CODE (x))
6132 {
6133 case CONST:
6134 case SYMBOL_REF:
6135 case LABEL_REF:
6136 reloc = 0;
6137 for_each_rtx (&x, compute_reloc_for_rtx_1, &reloc);
6138 return reloc;
6139
6140 default:
6141 return 0;
6142 }
6143 }
6144
6145 section *
6146 default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED,
6147 rtx x,
6148 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
6149 {
6150 if (compute_reloc_for_rtx (x) & targetm.asm_out.reloc_rw_mask ())
6151 return data_section;
6152 else
6153 return readonly_data_section;
6154 }
6155
6156 section *
6157 default_elf_select_rtx_section (enum machine_mode mode, rtx x,
6158 unsigned HOST_WIDE_INT align)
6159 {
6160 int reloc = compute_reloc_for_rtx (x);
6161
6162 /* ??? Handle small data here somehow. */
6163
6164 if (reloc & targetm.asm_out.reloc_rw_mask ())
6165 {
6166 if (reloc == 1)
6167 return get_named_section (NULL, ".data.rel.ro.local", 1);
6168 else
6169 return get_named_section (NULL, ".data.rel.ro", 3);
6170 }
6171
6172 return mergeable_constant_section (mode, align, 0);
6173 }
6174
6175 /* Set the generally applicable flags on the SYMBOL_REF for EXP. */
6176
6177 void
6178 default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
6179 {
6180 rtx symbol;
6181 int flags;
6182
6183 /* Careful not to prod global register variables. */
6184 if (!MEM_P (rtl))
6185 return;
6186 symbol = XEXP (rtl, 0);
6187 if (GET_CODE (symbol) != SYMBOL_REF)
6188 return;
6189
6190 flags = SYMBOL_REF_FLAGS (symbol) & SYMBOL_FLAG_HAS_BLOCK_INFO;
6191 if (TREE_CODE (decl) == FUNCTION_DECL)
6192 flags |= SYMBOL_FLAG_FUNCTION;
6193 if (targetm.binds_local_p (decl))
6194 flags |= SYMBOL_FLAG_LOCAL;
6195 if (targetm.have_tls && TREE_CODE (decl) == VAR_DECL
6196 && DECL_THREAD_LOCAL_P (decl))
6197 flags |= DECL_TLS_MODEL (decl) << SYMBOL_FLAG_TLS_SHIFT;
6198 else if (targetm.in_small_data_p (decl))
6199 flags |= SYMBOL_FLAG_SMALL;
6200 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without
6201 being PUBLIC, the thing *must* be defined in this translation unit.
6202 Prevent this buglet from being propagated into rtl code as well. */
6203 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
6204 flags |= SYMBOL_FLAG_EXTERNAL;
6205
6206 SYMBOL_REF_FLAGS (symbol) = flags;
6207 }
6208
6209 /* By default, we do nothing for encode_section_info, so we need not
6210 do anything but discard the '*' marker. */
6211
6212 const char *
6213 default_strip_name_encoding (const char *str)
6214 {
6215 return str + (*str == '*');
6216 }
6217
6218 #ifdef ASM_OUTPUT_DEF
6219 /* The default implementation of TARGET_ASM_OUTPUT_ANCHOR. Define the
6220 anchor relative to ".", the current section position. */
6221
6222 void
6223 default_asm_output_anchor (rtx symbol)
6224 {
6225 char buffer[100];
6226
6227 sprintf (buffer, "*. + " HOST_WIDE_INT_PRINT_DEC,
6228 SYMBOL_REF_BLOCK_OFFSET (symbol));
6229 ASM_OUTPUT_DEF (asm_out_file, XSTR (symbol, 0), buffer);
6230 }
6231 #endif
6232
6233 /* The default implementation of TARGET_USE_ANCHORS_FOR_SYMBOL_P. */
6234
6235 bool
6236 default_use_anchors_for_symbol_p (const_rtx symbol)
6237 {
6238 section *sect;
6239 tree decl;
6240
6241 /* Don't use anchors for mergeable sections. The linker might move
6242 the objects around. */
6243 sect = SYMBOL_REF_BLOCK (symbol)->sect;
6244 if (sect->common.flags & SECTION_MERGE)
6245 return false;
6246
6247 /* Don't use anchors for small data sections. The small data register
6248 acts as an anchor for such sections. */
6249 if (sect->common.flags & SECTION_SMALL)
6250 return false;
6251
6252 decl = SYMBOL_REF_DECL (symbol);
6253 if (decl && DECL_P (decl))
6254 {
6255 /* Don't use section anchors for decls that might be defined by
6256 other modules. */
6257 if (!targetm.binds_local_p (decl))
6258 return false;
6259
6260 /* Don't use section anchors for decls that will be placed in a
6261 small data section. */
6262 /* ??? Ideally, this check would be redundant with the SECTION_SMALL
6263 one above. The problem is that we only use SECTION_SMALL for
6264 sections that should be marked as small in the section directive. */
6265 if (targetm.in_small_data_p (decl))
6266 return false;
6267 }
6268 return true;
6269 }
6270
6271 /* Assume ELF-ish defaults, since that's pretty much the most liberal
6272 wrt cross-module name binding. */
6273
6274 bool
6275 default_binds_local_p (const_tree exp)
6276 {
6277 return default_binds_local_p_1 (exp, flag_shlib);
6278 }
6279
6280 bool
6281 default_binds_local_p_1 (const_tree exp, int shlib)
6282 {
6283 bool local_p;
6284
6285 /* A non-decl is an entry in the constant pool. */
6286 if (!DECL_P (exp))
6287 local_p = true;
6288 /* Weakrefs may not bind locally, even though the weakref itself is
6289 always static and therefore local. */
6290 else if (lookup_attribute ("weakref", DECL_ATTRIBUTES (exp)))
6291 local_p = false;
6292 /* Static variables are always local. */
6293 else if (! TREE_PUBLIC (exp))
6294 local_p = true;
6295 /* A variable is local if the user has said explicitly that it will
6296 be. */
6297 else if (DECL_VISIBILITY_SPECIFIED (exp)
6298 && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6299 local_p = true;
6300 /* Variables defined outside this object might not be local. */
6301 else if (DECL_EXTERNAL (exp))
6302 local_p = false;
6303 /* If defined in this object and visibility is not default, must be
6304 local. */
6305 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6306 local_p = true;
6307 /* Default visibility weak data can be overridden by a strong symbol
6308 in another module and so are not local. */
6309 else if (DECL_WEAK (exp))
6310 local_p = false;
6311 /* If PIC, then assume that any global name can be overridden by
6312 symbols resolved from other modules, unless we are compiling with
6313 -fwhole-program, which assumes that names are local. */
6314 else if (shlib)
6315 local_p = flag_whole_program;
6316 /* Uninitialized COMMON variable may be unified with symbols
6317 resolved from other modules. */
6318 else if (DECL_COMMON (exp)
6319 && (DECL_INITIAL (exp) == NULL
6320 || DECL_INITIAL (exp) == error_mark_node))
6321 local_p = false;
6322 /* Otherwise we're left with initialized (or non-common) global data
6323 which is of necessity defined locally. */
6324 else
6325 local_p = true;
6326
6327 return local_p;
6328 }
6329
6330 /* Determine whether or not a pointer mode is valid. Assume defaults
6331 of ptr_mode or Pmode - can be overridden. */
6332 bool
6333 default_valid_pointer_mode (enum machine_mode mode)
6334 {
6335 return (mode == ptr_mode || mode == Pmode);
6336 }
6337
6338 /* Default function to output code that will globalize a label. A
6339 target must define GLOBAL_ASM_OP or provide its own function to
6340 globalize a label. */
6341 #ifdef GLOBAL_ASM_OP
6342 void
6343 default_globalize_label (FILE * stream, const char *name)
6344 {
6345 fputs (GLOBAL_ASM_OP, stream);
6346 assemble_name (stream, name);
6347 putc ('\n', stream);
6348 }
6349 #endif /* GLOBAL_ASM_OP */
6350
6351 /* Default function to output code that will globalize a declaration. */
6352 void
6353 default_globalize_decl_name (FILE * stream, tree decl)
6354 {
6355 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
6356 targetm.asm_out.globalize_label (stream, name);
6357 }
6358
6359 /* Default function to output a label for unwind information. The
6360 default is to do nothing. A target that needs nonlocal labels for
6361 unwind information must provide its own function to do this. */
6362 void
6363 default_emit_unwind_label (FILE * stream ATTRIBUTE_UNUSED,
6364 tree decl ATTRIBUTE_UNUSED,
6365 int for_eh ATTRIBUTE_UNUSED,
6366 int empty ATTRIBUTE_UNUSED)
6367 {
6368 }
6369
6370 /* Default function to output a label to divide up the exception table.
6371 The default is to do nothing. A target that needs/wants to divide
6372 up the table must provide it's own function to do this. */
6373 void
6374 default_emit_except_table_label (FILE * stream ATTRIBUTE_UNUSED)
6375 {
6376 }
6377
6378 /* This is how to output an internal numbered label where PREFIX is
6379 the class of label and LABELNO is the number within the class. */
6380
6381 void
6382 default_internal_label (FILE *stream, const char *prefix,
6383 unsigned long labelno)
6384 {
6385 char *const buf = (char *) alloca (40 + strlen (prefix));
6386 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
6387 ASM_OUTPUT_INTERNAL_LABEL (stream, buf);
6388 }
6389
6390 /* This is the default behavior at the beginning of a file. It's
6391 controlled by two other target-hook toggles. */
6392 void
6393 default_file_start (void)
6394 {
6395 if (targetm.file_start_app_off
6396 && !(flag_verbose_asm || flag_debug_asm || flag_dump_rtl_in_asm))
6397 fputs (ASM_APP_OFF, asm_out_file);
6398
6399 if (targetm.file_start_file_directive)
6400 output_file_directive (asm_out_file, main_input_filename);
6401 }
6402
6403 /* This is a generic routine suitable for use as TARGET_ASM_FILE_END
6404 which emits a special section directive used to indicate whether or
6405 not this object file needs an executable stack. This is primarily
6406 a GNU extension to ELF but could be used on other targets. */
6407
6408 int trampolines_created;
6409
6410 void
6411 file_end_indicate_exec_stack (void)
6412 {
6413 unsigned int flags = SECTION_DEBUG;
6414 if (trampolines_created)
6415 flags |= SECTION_CODE;
6416
6417 switch_to_section (get_section (".note.GNU-stack", flags, NULL));
6418 }
6419
6420 /* Output DIRECTIVE (a C string) followed by a newline. This is used as
6421 a get_unnamed_section callback. */
6422
6423 void
6424 output_section_asm_op (const void *directive)
6425 {
6426 fprintf (asm_out_file, "%s\n", (const char *) directive);
6427 }
6428
6429 /* Emit assembly code to switch to section NEW_SECTION. Do nothing if
6430 the current section is NEW_SECTION. */
6431
6432 void
6433 switch_to_section (section *new_section)
6434 {
6435 if (in_section == new_section)
6436 return;
6437
6438 if (new_section->common.flags & SECTION_FORGET)
6439 in_section = NULL;
6440 else
6441 in_section = new_section;
6442
6443 switch (SECTION_STYLE (new_section))
6444 {
6445 case SECTION_NAMED:
6446 if (cfun
6447 && !crtl->subsections.unlikely_text_section_name
6448 && strcmp (new_section->named.name,
6449 UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
6450 crtl->subsections.unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
6451
6452 targetm.asm_out.named_section (new_section->named.name,
6453 new_section->named.common.flags,
6454 new_section->named.decl);
6455 break;
6456
6457 case SECTION_UNNAMED:
6458 new_section->unnamed.callback (new_section->unnamed.data);
6459 break;
6460
6461 case SECTION_NOSWITCH:
6462 gcc_unreachable ();
6463 break;
6464 }
6465
6466 new_section->common.flags |= SECTION_DECLARED;
6467 }
6468
6469 /* If block symbol SYMBOL has not yet been assigned an offset, place
6470 it at the end of its block. */
6471
6472 void
6473 place_block_symbol (rtx symbol)
6474 {
6475 unsigned HOST_WIDE_INT size, mask, offset;
6476 struct constant_descriptor_rtx *desc;
6477 unsigned int alignment;
6478 struct object_block *block;
6479 tree decl;
6480
6481 gcc_assert (SYMBOL_REF_BLOCK (symbol));
6482 if (SYMBOL_REF_BLOCK_OFFSET (symbol) >= 0)
6483 return;
6484
6485 /* Work out the symbol's size and alignment. */
6486 if (CONSTANT_POOL_ADDRESS_P (symbol))
6487 {
6488 desc = SYMBOL_REF_CONSTANT (symbol);
6489 alignment = desc->align;
6490 size = GET_MODE_SIZE (desc->mode);
6491 }
6492 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6493 {
6494 decl = SYMBOL_REF_DECL (symbol);
6495 alignment = get_constant_alignment (decl);
6496 size = get_constant_size (decl);
6497 }
6498 else
6499 {
6500 decl = SYMBOL_REF_DECL (symbol);
6501 alignment = DECL_ALIGN (decl);
6502 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6503 }
6504
6505 /* Calculate the object's offset from the start of the block. */
6506 block = SYMBOL_REF_BLOCK (symbol);
6507 mask = alignment / BITS_PER_UNIT - 1;
6508 offset = (block->size + mask) & ~mask;
6509 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
6510
6511 /* Record the block's new alignment and size. */
6512 block->alignment = MAX (block->alignment, alignment);
6513 block->size = offset + size;
6514
6515 VEC_safe_push (rtx, gc, block->objects, symbol);
6516 }
6517
6518 /* Return the anchor that should be used to address byte offset OFFSET
6519 from the first object in BLOCK. MODEL is the TLS model used
6520 to access it. */
6521
6522 rtx
6523 get_section_anchor (struct object_block *block, HOST_WIDE_INT offset,
6524 enum tls_model model)
6525 {
6526 char label[100];
6527 unsigned int begin, middle, end;
6528 unsigned HOST_WIDE_INT min_offset, max_offset, range, bias, delta;
6529 rtx anchor;
6530
6531 /* Work out the anchor's offset. Use an offset of 0 for the first
6532 anchor so that we don't pessimize the case where we take the address
6533 of a variable at the beginning of the block. This is particularly
6534 useful when a block has only one variable assigned to it.
6535
6536 We try to place anchors RANGE bytes apart, so there can then be
6537 anchors at +/-RANGE, +/-2 * RANGE, and so on, up to the limits of
6538 a ptr_mode offset. With some target settings, the lowest such
6539 anchor might be out of range for the lowest ptr_mode offset;
6540 likewise the highest anchor for the highest offset. Use anchors
6541 at the extreme ends of the ptr_mode range in such cases.
6542
6543 All arithmetic uses unsigned integers in order to avoid
6544 signed overflow. */
6545 max_offset = (unsigned HOST_WIDE_INT) targetm.max_anchor_offset;
6546 min_offset = (unsigned HOST_WIDE_INT) targetm.min_anchor_offset;
6547 range = max_offset - min_offset + 1;
6548 if (range == 0)
6549 offset = 0;
6550 else
6551 {
6552 bias = 1 << (GET_MODE_BITSIZE (ptr_mode) - 1);
6553 if (offset < 0)
6554 {
6555 delta = -(unsigned HOST_WIDE_INT) offset + max_offset;
6556 delta -= delta % range;
6557 if (delta > bias)
6558 delta = bias;
6559 offset = (HOST_WIDE_INT) (-delta);
6560 }
6561 else
6562 {
6563 delta = (unsigned HOST_WIDE_INT) offset - min_offset;
6564 delta -= delta % range;
6565 if (delta > bias - 1)
6566 delta = bias - 1;
6567 offset = (HOST_WIDE_INT) delta;
6568 }
6569 }
6570
6571 /* Do a binary search to see if there's already an anchor we can use.
6572 Set BEGIN to the new anchor's index if not. */
6573 begin = 0;
6574 end = VEC_length (rtx, block->anchors);
6575 while (begin != end)
6576 {
6577 middle = (end + begin) / 2;
6578 anchor = VEC_index (rtx, block->anchors, middle);
6579 if (SYMBOL_REF_BLOCK_OFFSET (anchor) > offset)
6580 end = middle;
6581 else if (SYMBOL_REF_BLOCK_OFFSET (anchor) < offset)
6582 begin = middle + 1;
6583 else if (SYMBOL_REF_TLS_MODEL (anchor) > model)
6584 end = middle;
6585 else if (SYMBOL_REF_TLS_MODEL (anchor) < model)
6586 begin = middle + 1;
6587 else
6588 return anchor;
6589 }
6590
6591 /* Create a new anchor with a unique label. */
6592 ASM_GENERATE_INTERNAL_LABEL (label, "LANCHOR", anchor_labelno++);
6593 anchor = create_block_symbol (ggc_strdup (label), block, offset);
6594 SYMBOL_REF_FLAGS (anchor) |= SYMBOL_FLAG_LOCAL | SYMBOL_FLAG_ANCHOR;
6595 SYMBOL_REF_FLAGS (anchor) |= model << SYMBOL_FLAG_TLS_SHIFT;
6596
6597 /* Insert it at index BEGIN. */
6598 VEC_safe_insert (rtx, gc, block->anchors, begin, anchor);
6599 return anchor;
6600 }
6601
6602 /* Output the objects in BLOCK. */
6603
6604 static void
6605 output_object_block (struct object_block *block)
6606 {
6607 struct constant_descriptor_rtx *desc;
6608 unsigned int i;
6609 HOST_WIDE_INT offset;
6610 tree decl;
6611 rtx symbol;
6612
6613 if (block->objects == NULL)
6614 return;
6615
6616 /* Switch to the section and make sure that the first byte is
6617 suitably aligned. */
6618 switch_to_section (block->sect);
6619 assemble_align (block->alignment);
6620
6621 /* Define the values of all anchors relative to the current section
6622 position. */
6623 for (i = 0; VEC_iterate (rtx, block->anchors, i, symbol); i++)
6624 targetm.asm_out.output_anchor (symbol);
6625
6626 /* Output the objects themselves. */
6627 offset = 0;
6628 for (i = 0; VEC_iterate (rtx, block->objects, i, symbol); i++)
6629 {
6630 /* Move to the object's offset, padding with zeros if necessary. */
6631 assemble_zeros (SYMBOL_REF_BLOCK_OFFSET (symbol) - offset);
6632 offset = SYMBOL_REF_BLOCK_OFFSET (symbol);
6633 if (CONSTANT_POOL_ADDRESS_P (symbol))
6634 {
6635 desc = SYMBOL_REF_CONSTANT (symbol);
6636 output_constant_pool_1 (desc, 1);
6637 offset += GET_MODE_SIZE (desc->mode);
6638 }
6639 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6640 {
6641 decl = SYMBOL_REF_DECL (symbol);
6642 assemble_constant_contents (decl, XSTR (symbol, 0),
6643 get_constant_alignment (decl));
6644 offset += get_constant_size (decl);
6645 }
6646 else
6647 {
6648 decl = SYMBOL_REF_DECL (symbol);
6649 assemble_variable_contents (decl, XSTR (symbol, 0), false);
6650 offset += tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6651 }
6652 }
6653 }
6654
6655 /* A htab_traverse callback used to call output_object_block for
6656 each member of object_block_htab. */
6657
6658 static int
6659 output_object_block_htab (void **slot, void *data ATTRIBUTE_UNUSED)
6660 {
6661 output_object_block ((struct object_block *) (*slot));
6662 return 1;
6663 }
6664
6665 /* Output the definitions of all object_blocks. */
6666
6667 void
6668 output_object_blocks (void)
6669 {
6670 htab_traverse (object_block_htab, output_object_block_htab, NULL);
6671 }
6672
6673 /* This function provides a possible implementation of the
6674 TARGET_ASM_RECORD_GCC_SWITCHES target hook for ELF targets. When triggered
6675 by -frecord-gcc-switches it creates a new mergeable, string section in the
6676 assembler output file called TARGET_ASM_RECORD_GCC_SWITCHES_SECTION which
6677 contains the switches in ASCII format.
6678
6679 FIXME: This code does not correctly handle double quote characters
6680 that appear inside strings, (it strips them rather than preserving them).
6681 FIXME: ASM_OUTPUT_ASCII, as defined in config/elfos.h will not emit NUL
6682 characters - instead it treats them as sub-string separators. Since
6683 we want to emit NUL strings terminators into the object file we have to use
6684 ASM_OUTPUT_SKIP. */
6685
6686 int
6687 elf_record_gcc_switches (print_switch_type type, const char * name)
6688 {
6689 static char buffer[1024];
6690
6691 /* This variable is used as part of a simplistic heuristic to detect
6692 command line switches which take an argument:
6693
6694 "If a command line option does not start with a dash then
6695 it is an argument for the previous command line option."
6696
6697 This fails in the case of the command line option which is the name
6698 of the file to compile, but otherwise it is pretty reasonable. */
6699 static bool previous_name_held_back = FALSE;
6700
6701 switch (type)
6702 {
6703 case SWITCH_TYPE_PASSED:
6704 if (* name != '-')
6705 {
6706 if (previous_name_held_back)
6707 {
6708 unsigned int len = strlen (buffer);
6709
6710 snprintf (buffer + len, sizeof buffer - len, " %s", name);
6711 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6712 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6713 previous_name_held_back = FALSE;
6714 }
6715 else
6716 {
6717 strncpy (buffer, name, sizeof buffer);
6718 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6719 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6720 }
6721 }
6722 else
6723 {
6724 if (previous_name_held_back)
6725 {
6726 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6727 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6728 }
6729
6730 strncpy (buffer, name, sizeof buffer);
6731 previous_name_held_back = TRUE;
6732 }
6733 break;
6734
6735 case SWITCH_TYPE_DESCRIPTIVE:
6736 if (name == NULL)
6737 {
6738 /* Distinguish between invocations where name is NULL. */
6739 static bool started = false;
6740
6741 if (started)
6742 {
6743 if (previous_name_held_back)
6744 {
6745 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6746 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6747 }
6748 }
6749 else
6750 {
6751 section * sec;
6752
6753 sec = get_section (targetm.asm_out.record_gcc_switches_section,
6754 SECTION_DEBUG
6755 | SECTION_MERGE
6756 | SECTION_STRINGS
6757 | (SECTION_ENTSIZE & 1),
6758 NULL);
6759 switch_to_section (sec);
6760 started = true;
6761 }
6762 }
6763
6764 default:
6765 break;
6766 }
6767
6768 /* The return value is currently ignored by the caller, but must be 0.
6769 For -fverbose-asm the return value would be the number of characters
6770 emitted into the assembler file. */
6771 return 0;
6772 }
6773
6774 /* Emit text to declare externally defined symbols. It is needed to
6775 properly support non-default visibility. */
6776 void
6777 default_elf_asm_output_external (FILE *file ATTRIBUTE_UNUSED,
6778 tree decl,
6779 const char *name ATTRIBUTE_UNUSED)
6780 {
6781 /* We output the name if and only if TREE_SYMBOL_REFERENCED is
6782 set in order to avoid putting out names that are never really
6783 used. */
6784 if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))
6785 && targetm.binds_local_p (decl))
6786 maybe_assemble_visibility (decl);
6787 }
6788
6789 #include "gt-varasm.h"