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 2, 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 COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
21 02110-1301, USA. */
22
23
24 /* This file handles generation of all the assembler code
25 *except* the instructions of a function.
26 This includes declarations of variables and their initial values.
27
28 We also output the assembler code for constants stored in memory
29 and are responsible for combining constants with the same value. */
30
31 #include "config.h"
32 #include "system.h"
33 #include "coretypes.h"
34 #include "tm.h"
35 #include "rtl.h"
36 #include "tree.h"
37 #include "flags.h"
38 #include "function.h"
39 #include "expr.h"
40 #include "hard-reg-set.h"
41 #include "regs.h"
42 #include "real.h"
43 #include "output.h"
44 #include "toplev.h"
45 #include "hashtab.h"
46 #include "c-pragma.h"
47 #include "ggc.h"
48 #include "langhooks.h"
49 #include "tm_p.h"
50 #include "debug.h"
51 #include "target.h"
52 #include "tree-mudflap.h"
53 #include "cgraph.h"
54 #include "cfglayout.h"
55 #include "basic-block.h"
56
57 #ifdef XCOFF_DEBUGGING_INFO
58 #include "xcoffout.h" /* Needed for external data
59 declarations for e.g. AIX 4.x. */
60 #endif
61
62 /* The (assembler) name of the first globally-visible object output. */
63 extern GTY(()) const char *first_global_object_name;
64 extern GTY(()) const char *weak_global_object_name;
65
66 const char *first_global_object_name;
67 const char *weak_global_object_name;
68
69 struct addr_const;
70 struct constant_descriptor_rtx;
71 struct rtx_constant_pool;
72
73 struct varasm_status GTY(())
74 {
75 /* If we're using a per-function constant pool, this is it. */
76 struct rtx_constant_pool *pool;
77
78 /* Number of tree-constants deferred during the expansion of this
79 function. */
80 unsigned int deferred_constants;
81 };
82
83 #define n_deferred_constants (cfun->varasm->deferred_constants)
84
85 /* Number for making the label on the next
86 constant that is stored in memory. */
87
88 static GTY(()) int const_labelno;
89
90 /* Carry information from ASM_DECLARE_OBJECT_NAME
91 to ASM_FINISH_DECLARE_OBJECT. */
92
93 int size_directive_output;
94
95 /* The last decl for which assemble_variable was called,
96 if it did ASM_DECLARE_OBJECT_NAME.
97 If the last call to assemble_variable didn't do that,
98 this holds 0. */
99
100 tree last_assemble_variable_decl;
101
102 /* The following global variable indicates if the first basic block
103 in a function belongs to the cold partition or not. */
104
105 bool first_function_block_is_cold;
106
107 /* We give all constants their own alias set. Perhaps redundant with
108 MEM_READONLY_P, but pre-dates it. */
109
110 static HOST_WIDE_INT const_alias_set;
111
112 static const char *strip_reg_name (const char *);
113 static int contains_pointers_p (tree);
114 #ifdef ASM_OUTPUT_EXTERNAL
115 static bool incorporeal_function_p (tree);
116 #endif
117 static void decode_addr_const (tree, struct addr_const *);
118 static hashval_t const_desc_hash (const void *);
119 static int const_desc_eq (const void *, const void *);
120 static hashval_t const_hash_1 (const tree);
121 static int compare_constant (const tree, const tree);
122 static tree copy_constant (tree);
123 static void output_constant_def_contents (rtx);
124 static void output_addressed_constants (tree);
125 static unsigned HOST_WIDE_INT array_size_for_constructor (tree);
126 static unsigned min_align (unsigned, unsigned);
127 static void output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int);
128 static void globalize_decl (tree);
129 #ifdef BSS_SECTION_ASM_OP
130 #ifdef ASM_OUTPUT_BSS
131 static void asm_output_bss (FILE *, tree, const char *,
132 unsigned HOST_WIDE_INT, unsigned HOST_WIDE_INT);
133 #endif
134 #ifdef ASM_OUTPUT_ALIGNED_BSS
135 static void asm_output_aligned_bss (FILE *, tree, const char *,
136 unsigned HOST_WIDE_INT, int)
137 ATTRIBUTE_UNUSED;
138 #endif
139 #endif /* BSS_SECTION_ASM_OP */
140 static void mark_weak (tree);
141 static void output_constant_pool (const char *, tree);
142
143 /* Well-known sections, each one associated with some sort of *_ASM_OP. */
144 section *text_section;
145 section *data_section;
146 section *readonly_data_section;
147 section *sdata_section;
148 section *ctors_section;
149 section *dtors_section;
150 section *bss_section;
151 section *sbss_section;
152
153 /* Various forms of common section. All are guaranteed to be nonnull. */
154 section *tls_comm_section;
155 section *comm_section;
156 section *lcomm_section;
157
158 /* A SECTION_NOSWITCH section used for declaring global BSS variables.
159 May be null. */
160 section *bss_noswitch_section;
161
162 /* The section that holds the main exception table, when known. The section
163 is set either by the target's init_sections hook or by the first call to
164 switch_to_exception_section. */
165 section *exception_section;
166
167 /* The section that holds the DWARF2 frame unwind information, when known.
168 The section is set either by the target's init_sections hook or by the
169 first call to switch_to_eh_frame_section. */
170 section *eh_frame_section;
171
172 /* asm_out_file's current section. This is NULL if no section has yet
173 been selected or if we lose track of what the current section is. */
174 section *in_section;
175
176 /* True if code for the current function is currently being directed
177 at the cold section. */
178 bool in_cold_section_p;
179
180 /* A linked list of all the unnamed sections. */
181 static GTY(()) section *unnamed_sections;
182
183 /* Return a nonzero value if DECL has a section attribute. */
184 #ifndef IN_NAMED_SECTION
185 #define IN_NAMED_SECTION(DECL) \
186 ((TREE_CODE (DECL) == FUNCTION_DECL || TREE_CODE (DECL) == VAR_DECL) \
187 && DECL_SECTION_NAME (DECL) != NULL_TREE)
188 #endif
189
190 /* Hash table of named sections. */
191 static GTY((param_is (section))) htab_t section_htab;
192
193 /* A table of object_blocks, indexed by section. */
194 static GTY((param_is (struct object_block))) htab_t object_block_htab;
195
196 /* The next number to use for internal anchor labels. */
197 static GTY(()) int anchor_labelno;
198
199 /* A pool of constants that can be shared between functions. */
200 static GTY(()) struct rtx_constant_pool *shared_constant_pool;
201
202 /* Helper routines for maintaining section_htab. */
203
204 static int
section_entry_eq(const void * p1,const void * p2)205 section_entry_eq (const void *p1, const void *p2)
206 {
207 const section *old = p1;
208 const char *new = p2;
209
210 return strcmp (old->named.name, new) == 0;
211 }
212
213 static hashval_t
section_entry_hash(const void * p)214 section_entry_hash (const void *p)
215 {
216 const section *old = p;
217 return htab_hash_string (old->named.name);
218 }
219
220 /* Return a hash value for section SECT. */
221
222 static hashval_t
hash_section(section * sect)223 hash_section (section *sect)
224 {
225 if (sect->common.flags & SECTION_NAMED)
226 return htab_hash_string (sect->named.name);
227 return sect->common.flags;
228 }
229
230 /* Helper routines for maintaining object_block_htab. */
231
232 static int
object_block_entry_eq(const void * p1,const void * p2)233 object_block_entry_eq (const void *p1, const void *p2)
234 {
235 const struct object_block *old = p1;
236 const section *new = p2;
237
238 return old->sect == new;
239 }
240
241 static hashval_t
object_block_entry_hash(const void * p)242 object_block_entry_hash (const void *p)
243 {
244 const struct object_block *old = p;
245 return hash_section (old->sect);
246 }
247
248 /* Return a new unnamed section with the given fields. */
249
250 section *
get_unnamed_section(unsigned int flags,void (* callback)(const void *),const void * data)251 get_unnamed_section (unsigned int flags, void (*callback) (const void *),
252 const void *data)
253 {
254 section *sect;
255
256 sect = ggc_alloc (sizeof (struct unnamed_section));
257 sect->unnamed.common.flags = flags | SECTION_UNNAMED;
258 sect->unnamed.callback = callback;
259 sect->unnamed.data = data;
260 sect->unnamed.next = unnamed_sections;
261
262 unnamed_sections = sect;
263 return sect;
264 }
265
266 /* Return a SECTION_NOSWITCH section with the given fields. */
267
268 static section *
get_noswitch_section(unsigned int flags,noswitch_section_callback callback)269 get_noswitch_section (unsigned int flags, noswitch_section_callback callback)
270 {
271 section *sect;
272
273 sect = ggc_alloc (sizeof (struct unnamed_section));
274 sect->noswitch.common.flags = flags | SECTION_NOSWITCH;
275 sect->noswitch.callback = callback;
276
277 return sect;
278 }
279
280 /* Return the named section structure associated with NAME. Create
281 a new section with the given fields if no such structure exists. */
282
283 section *
get_section(const char * name,unsigned int flags,tree decl)284 get_section (const char *name, unsigned int flags, tree decl)
285 {
286 section *sect, **slot;
287
288 slot = (section **)
289 htab_find_slot_with_hash (section_htab, name,
290 htab_hash_string (name), INSERT);
291 flags |= SECTION_NAMED;
292 if (*slot == NULL)
293 {
294 sect = ggc_alloc (sizeof (struct named_section));
295 sect->named.common.flags = flags;
296 sect->named.name = ggc_strdup (name);
297 sect->named.decl = decl;
298 *slot = sect;
299 }
300 else
301 {
302 sect = *slot;
303 if ((sect->common.flags & ~SECTION_DECLARED) != flags
304 && ((sect->common.flags | flags) & SECTION_OVERRIDE) == 0)
305 {
306 /* Sanity check user variables for flag changes. */
307 if (decl == 0)
308 decl = sect->named.decl;
309 gcc_assert (decl);
310 error ("%+D causes a section type conflict", decl);
311 }
312 }
313 return sect;
314 }
315
316 /* Return true if the current compilation mode benefits from having
317 objects grouped into blocks. */
318
319 static bool
use_object_blocks_p(void)320 use_object_blocks_p (void)
321 {
322 return flag_section_anchors;
323 }
324
325 /* Return the object_block structure for section SECT. Create a new
326 structure if we haven't created one already. Return null if SECT
327 itself is null. */
328
329 static struct object_block *
get_block_for_section(section * sect)330 get_block_for_section (section *sect)
331 {
332 struct object_block *block;
333 void **slot;
334
335 if (sect == NULL)
336 return NULL;
337
338 slot = htab_find_slot_with_hash (object_block_htab, sect,
339 hash_section (sect), INSERT);
340 block = (struct object_block *) *slot;
341 if (block == NULL)
342 {
343 block = (struct object_block *)
344 ggc_alloc_cleared (sizeof (struct object_block));
345 block->sect = sect;
346 *slot = block;
347 }
348 return block;
349 }
350
351 /* Create a symbol with label LABEL and place it at byte offset
352 OFFSET in BLOCK. OFFSET can be negative if the symbol's offset
353 is not yet known. LABEL must be a garbage-collected string. */
354
355 static rtx
create_block_symbol(const char * label,struct object_block * block,HOST_WIDE_INT offset)356 create_block_symbol (const char *label, struct object_block *block,
357 HOST_WIDE_INT offset)
358 {
359 rtx symbol;
360 unsigned int size;
361
362 /* Create the extended SYMBOL_REF. */
363 size = RTX_HDR_SIZE + sizeof (struct block_symbol);
364 symbol = ggc_alloc_zone (size, &rtl_zone);
365
366 /* Initialize the normal SYMBOL_REF fields. */
367 memset (symbol, 0, size);
368 PUT_CODE (symbol, SYMBOL_REF);
369 PUT_MODE (symbol, Pmode);
370 XSTR (symbol, 0) = label;
371 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_HAS_BLOCK_INFO;
372
373 /* Initialize the block_symbol stuff. */
374 SYMBOL_REF_BLOCK (symbol) = block;
375 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
376
377 return symbol;
378 }
379
380 static void
initialize_cold_section_name(void)381 initialize_cold_section_name (void)
382 {
383 const char *stripped_name;
384 char *name, *buffer;
385 tree dsn;
386
387 gcc_assert (cfun && current_function_decl);
388 if (cfun->unlikely_text_section_name)
389 return;
390
391 dsn = DECL_SECTION_NAME (current_function_decl);
392 if (flag_function_sections && dsn)
393 {
394 name = alloca (TREE_STRING_LENGTH (dsn) + 1);
395 memcpy (name, TREE_STRING_POINTER (dsn), TREE_STRING_LENGTH (dsn) + 1);
396
397 stripped_name = targetm.strip_name_encoding (name);
398
399 buffer = ACONCAT ((stripped_name, "_unlikely", NULL));
400 cfun->unlikely_text_section_name = ggc_strdup (buffer);
401 }
402 else
403 cfun->unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
404 }
405
406 /* Tell assembler to switch to unlikely-to-be-executed text section. */
407
408 section *
unlikely_text_section(void)409 unlikely_text_section (void)
410 {
411 if (cfun)
412 {
413 if (!cfun->unlikely_text_section_name)
414 initialize_cold_section_name ();
415
416 return get_named_section (NULL, cfun->unlikely_text_section_name, 0);
417 }
418 else
419 return get_named_section (NULL, UNLIKELY_EXECUTED_TEXT_SECTION_NAME, 0);
420 }
421
422 /* When called within a function context, return true if the function
423 has been assigned a cold text section and if SECT is that section.
424 When called outside a function context, return true if SECT is the
425 default cold section. */
426
427 bool
unlikely_text_section_p(section * sect)428 unlikely_text_section_p (section *sect)
429 {
430 const char *name;
431
432 if (cfun)
433 name = cfun->unlikely_text_section_name;
434 else
435 name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
436
437 return (name
438 && sect
439 && SECTION_STYLE (sect) == SECTION_NAMED
440 && strcmp (name, sect->named.name) == 0);
441 }
442
443 /* Return a section with a particular name and with whatever SECTION_*
444 flags section_type_flags deems appropriate. The name of the section
445 is taken from NAME if nonnull, otherwise it is taken from DECL's
446 DECL_SECTION_NAME. DECL is the decl associated with the section
447 (see the section comment for details) and RELOC is as for
448 section_type_flags. */
449
450 section *
get_named_section(tree decl,const char * name,int reloc)451 get_named_section (tree decl, const char *name, int reloc)
452 {
453 unsigned int flags;
454
455 gcc_assert (!decl || DECL_P (decl));
456 if (name == NULL)
457 name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
458
459 flags = targetm.section_type_flags (decl, name, reloc);
460
461 return get_section (name, flags, decl);
462 }
463
464 /* If required, set DECL_SECTION_NAME to a unique name. */
465
466 void
resolve_unique_section(tree decl,int reloc ATTRIBUTE_UNUSED,int flag_function_or_data_sections)467 resolve_unique_section (tree decl, int reloc ATTRIBUTE_UNUSED,
468 int flag_function_or_data_sections)
469 {
470 if (DECL_SECTION_NAME (decl) == NULL_TREE
471 && targetm.have_named_sections
472 && (flag_function_or_data_sections
473 || DECL_ONE_ONLY (decl)))
474 targetm.asm_out.unique_section (decl, reloc);
475 }
476
477 #ifdef BSS_SECTION_ASM_OP
478
479 #ifdef ASM_OUTPUT_BSS
480
481 /* Utility function for ASM_OUTPUT_BSS for targets to use if
482 they don't support alignments in .bss.
483 ??? It is believed that this function will work in most cases so such
484 support is localized here. */
485
486 static void
asm_output_bss(FILE * file,tree decl ATTRIBUTE_UNUSED,const char * name,unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,unsigned HOST_WIDE_INT rounded)487 asm_output_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
488 const char *name,
489 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
490 unsigned HOST_WIDE_INT rounded)
491 {
492 targetm.asm_out.globalize_label (file, name);
493 switch_to_section (bss_section);
494 #ifdef ASM_DECLARE_OBJECT_NAME
495 last_assemble_variable_decl = decl;
496 ASM_DECLARE_OBJECT_NAME (file, name, decl);
497 #else
498 /* Standard thing is just output label for the object. */
499 ASM_OUTPUT_LABEL (file, name);
500 #endif /* ASM_DECLARE_OBJECT_NAME */
501 ASM_OUTPUT_SKIP (file, rounded ? rounded : 1);
502 }
503
504 #endif
505
506 #ifdef ASM_OUTPUT_ALIGNED_BSS
507
508 /* Utility function for targets to use in implementing
509 ASM_OUTPUT_ALIGNED_BSS.
510 ??? It is believed that this function will work in most cases so such
511 support is localized here. */
512
513 static void
asm_output_aligned_bss(FILE * file,tree decl ATTRIBUTE_UNUSED,const char * name,unsigned HOST_WIDE_INT size,int align)514 asm_output_aligned_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
515 const char *name, unsigned HOST_WIDE_INT size,
516 int align)
517 {
518 switch_to_section (bss_section);
519 ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
520 #ifdef ASM_DECLARE_OBJECT_NAME
521 last_assemble_variable_decl = decl;
522 ASM_DECLARE_OBJECT_NAME (file, name, decl);
523 #else
524 /* Standard thing is just output label for the object. */
525 ASM_OUTPUT_LABEL (file, name);
526 #endif /* ASM_DECLARE_OBJECT_NAME */
527 ASM_OUTPUT_SKIP (file, size ? size : 1);
528 }
529
530 #endif
531
532 #endif /* BSS_SECTION_ASM_OP */
533
534 #ifndef USE_SELECT_SECTION_FOR_FUNCTIONS
535 /* Return the hot section for function DECL. Return text_section for
536 null DECLs. */
537
538 static section *
hot_function_section(tree decl)539 hot_function_section (tree decl)
540 {
541 if (decl != NULL_TREE
542 && DECL_SECTION_NAME (decl) != NULL_TREE
543 && targetm.have_named_sections)
544 return get_named_section (decl, NULL, 0);
545 else
546 return text_section;
547 }
548 #endif
549
550 /* Return the section for function DECL.
551
552 If DECL is NULL_TREE, return the text section. We can be passed
553 NULL_TREE under some circumstances by dbxout.c at least. */
554
555 section *
function_section(tree decl)556 function_section (tree decl)
557 {
558 int reloc = 0;
559
560 if (first_function_block_is_cold)
561 reloc = 1;
562
563 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
564 if (decl != NULL_TREE
565 && DECL_SECTION_NAME (decl) != NULL_TREE)
566 return reloc ? unlikely_text_section ()
567 : get_named_section (decl, NULL, 0);
568 else
569 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
570 #else
571 return reloc ? unlikely_text_section () : hot_function_section (decl);
572 #endif
573 }
574
575 section *
current_function_section(void)576 current_function_section (void)
577 {
578 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
579 if (current_function_decl != NULL_TREE
580 && DECL_SECTION_NAME (current_function_decl) != NULL_TREE)
581 return in_cold_section_p ? unlikely_text_section ()
582 : get_named_section (current_function_decl,
583 NULL, 0);
584 else
585 return targetm.asm_out.select_section (current_function_decl,
586 in_cold_section_p,
587 DECL_ALIGN (current_function_decl));
588 #else
589 return (in_cold_section_p
590 ? unlikely_text_section ()
591 : hot_function_section (current_function_decl));
592 #endif
593 }
594
595 /* Return the read-only data section associated with function DECL. */
596
597 section *
default_function_rodata_section(tree decl)598 default_function_rodata_section (tree decl)
599 {
600 if (decl != NULL_TREE && DECL_SECTION_NAME (decl))
601 {
602 const char *name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
603
604 if (DECL_ONE_ONLY (decl) && HAVE_COMDAT_GROUP)
605 {
606 size_t len = strlen (name) + 3;
607 char* rname = alloca (len);
608
609 strcpy (rname, ".rodata");
610 strcat (rname, name + 5);
611 return get_section (rname, SECTION_LINKONCE, decl);
612 }
613 /* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo. */
614 else if (DECL_ONE_ONLY (decl)
615 && strncmp (name, ".gnu.linkonce.t.", 16) == 0)
616 {
617 size_t len = strlen (name) + 1;
618 char *rname = alloca (len);
619
620 memcpy (rname, name, len);
621 rname[14] = 'r';
622 return get_section (rname, SECTION_LINKONCE, decl);
623 }
624 /* For .text.foo we want to use .rodata.foo. */
625 else if (flag_function_sections && flag_data_sections
626 && strncmp (name, ".text.", 6) == 0)
627 {
628 size_t len = strlen (name) + 1;
629 char *rname = alloca (len + 2);
630
631 memcpy (rname, ".rodata", 7);
632 memcpy (rname + 7, name + 5, len - 5);
633 return get_section (rname, 0, decl);
634 }
635 }
636
637 return readonly_data_section;
638 }
639
640 /* Return the read-only data section associated with function DECL
641 for targets where that section should be always the single
642 readonly data section. */
643
644 section *
default_no_function_rodata_section(tree decl ATTRIBUTE_UNUSED)645 default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED)
646 {
647 return readonly_data_section;
648 }
649
650 /* Return the section to use for string merging. */
651
652 static section *
mergeable_string_section(tree decl ATTRIBUTE_UNUSED,unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,unsigned int flags ATTRIBUTE_UNUSED)653 mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
654 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
655 unsigned int flags ATTRIBUTE_UNUSED)
656 {
657 HOST_WIDE_INT len;
658
659 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
660 && TREE_CODE (decl) == STRING_CST
661 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
662 && align <= 256
663 && (len = int_size_in_bytes (TREE_TYPE (decl))) > 0
664 && TREE_STRING_LENGTH (decl) >= len)
665 {
666 enum machine_mode mode;
667 unsigned int modesize;
668 const char *str;
669 HOST_WIDE_INT i;
670 int j, unit;
671 char name[30];
672
673 mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl)));
674 modesize = GET_MODE_BITSIZE (mode);
675 if (modesize >= 8 && modesize <= 256
676 && (modesize & (modesize - 1)) == 0)
677 {
678 if (align < modesize)
679 align = modesize;
680
681 str = TREE_STRING_POINTER (decl);
682 unit = GET_MODE_SIZE (mode);
683
684 /* Check for embedded NUL characters. */
685 for (i = 0; i < len; i += unit)
686 {
687 for (j = 0; j < unit; j++)
688 if (str[i + j] != '\0')
689 break;
690 if (j == unit)
691 break;
692 }
693 if (i == len - unit)
694 {
695 sprintf (name, ".rodata.str%d.%d", modesize / 8,
696 (int) (align / 8));
697 flags |= (modesize / 8) | SECTION_MERGE | SECTION_STRINGS;
698 return get_section (name, flags, NULL);
699 }
700 }
701 }
702
703 return readonly_data_section;
704 }
705
706 /* Return the section to use for constant merging. */
707
708 section *
mergeable_constant_section(enum machine_mode mode ATTRIBUTE_UNUSED,unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,unsigned int flags ATTRIBUTE_UNUSED)709 mergeable_constant_section (enum machine_mode mode ATTRIBUTE_UNUSED,
710 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
711 unsigned int flags ATTRIBUTE_UNUSED)
712 {
713 unsigned int modesize = GET_MODE_BITSIZE (mode);
714
715 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
716 && mode != VOIDmode
717 && mode != BLKmode
718 && modesize <= align
719 && align >= 8
720 && align <= 256
721 && (align & (align - 1)) == 0)
722 {
723 char name[24];
724
725 sprintf (name, ".rodata.cst%d", (int) (align / 8));
726 flags |= (align / 8) | SECTION_MERGE;
727 return get_section (name, flags, NULL);
728 }
729 return readonly_data_section;
730 }
731
732 /* Given NAME, a putative register name, discard any customary prefixes. */
733
734 static const char *
strip_reg_name(const char * name)735 strip_reg_name (const char *name)
736 {
737 #ifdef REGISTER_PREFIX
738 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
739 name += strlen (REGISTER_PREFIX);
740 #endif
741 if (name[0] == '%' || name[0] == '#')
742 name++;
743 return name;
744 }
745
746 /* The user has asked for a DECL to have a particular name. Set (or
747 change) it in such a way that we don't prefix an underscore to
748 it. */
749 void
set_user_assembler_name(tree decl,const char * name)750 set_user_assembler_name (tree decl, const char *name)
751 {
752 char *starred = alloca (strlen (name) + 2);
753 starred[0] = '*';
754 strcpy (starred + 1, name);
755 change_decl_assembler_name (decl, get_identifier (starred));
756 SET_DECL_RTL (decl, NULL_RTX);
757 }
758
759 /* Decode an `asm' spec for a declaration as a register name.
760 Return the register number, or -1 if nothing specified,
761 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
762 or -3 if ASMSPEC is `cc' and is not recognized,
763 or -4 if ASMSPEC is `memory' and is not recognized.
764 Accept an exact spelling or a decimal number.
765 Prefixes such as % are optional. */
766
767 int
decode_reg_name(const char * asmspec)768 decode_reg_name (const char *asmspec)
769 {
770 if (asmspec != 0)
771 {
772 int i;
773
774 /* Get rid of confusing prefixes. */
775 asmspec = strip_reg_name (asmspec);
776
777 /* Allow a decimal number as a "register name". */
778 for (i = strlen (asmspec) - 1; i >= 0; i--)
779 if (! ISDIGIT (asmspec[i]))
780 break;
781 if (asmspec[0] != 0 && i < 0)
782 {
783 i = atoi (asmspec);
784 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
785 return i;
786 else
787 return -2;
788 }
789
790 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
791 if (reg_names[i][0]
792 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
793 return i;
794
795 #ifdef ADDITIONAL_REGISTER_NAMES
796 {
797 static const struct { const char *const name; const int number; } table[]
798 = ADDITIONAL_REGISTER_NAMES;
799
800 for (i = 0; i < (int) ARRAY_SIZE (table); i++)
801 if (table[i].name[0]
802 && ! strcmp (asmspec, table[i].name))
803 return table[i].number;
804 }
805 #endif /* ADDITIONAL_REGISTER_NAMES */
806
807 if (!strcmp (asmspec, "memory"))
808 return -4;
809
810 if (!strcmp (asmspec, "cc"))
811 return -3;
812
813 return -2;
814 }
815
816 return -1;
817 }
818
819 /* Return true if DECL's initializer is suitable for a BSS section. */
820
821 static bool
bss_initializer_p(tree decl)822 bss_initializer_p (tree decl)
823 {
824 return (DECL_INITIAL (decl) == NULL
825 || DECL_INITIAL (decl) == error_mark_node
826 || (flag_zero_initialized_in_bss
827 /* Leave constant zeroes in .rodata so they
828 can be shared. */
829 && !TREE_READONLY (decl)
830 && initializer_zerop (DECL_INITIAL (decl))));
831 }
832
833 /* Compute the alignment of variable specified by DECL.
834 DONT_OUTPUT_DATA is from assemble_variable. */
835
836 void
align_variable(tree decl,bool dont_output_data)837 align_variable (tree decl, bool dont_output_data)
838 {
839 unsigned int align = DECL_ALIGN (decl);
840
841 /* In the case for initialing an array whose length isn't specified,
842 where we have not yet been able to do the layout,
843 figure out the proper alignment now. */
844 if (dont_output_data && DECL_SIZE (decl) == 0
845 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
846 align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
847
848 /* Some object file formats have a maximum alignment which they support.
849 In particular, a.out format supports a maximum alignment of 4. */
850 if (align > MAX_OFILE_ALIGNMENT)
851 {
852 warning (0, "alignment of %q+D is greater than maximum object "
853 "file alignment. Using %d", decl,
854 MAX_OFILE_ALIGNMENT/BITS_PER_UNIT);
855 align = MAX_OFILE_ALIGNMENT;
856 }
857
858 /* On some machines, it is good to increase alignment sometimes. */
859 if (! DECL_USER_ALIGN (decl))
860 {
861 #ifdef DATA_ALIGNMENT
862 align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
863 #endif
864 #ifdef CONSTANT_ALIGNMENT
865 if (DECL_INITIAL (decl) != 0 && DECL_INITIAL (decl) != error_mark_node)
866 align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl), align);
867 #endif
868 }
869
870 /* Reset the alignment in case we have made it tighter, so we can benefit
871 from it in get_pointer_alignment. */
872 DECL_ALIGN (decl) = align;
873 }
874
875 /* Return the section into which the given VAR_DECL or CONST_DECL
876 should be placed. PREFER_NOSWITCH_P is true if a noswitch
877 section should be used wherever possible. */
878
879 static section *
get_variable_section(tree decl,bool prefer_noswitch_p)880 get_variable_section (tree decl, bool prefer_noswitch_p)
881 {
882 int reloc;
883
884 /* If the decl has been given an explicit section name, then it
885 isn't common, and shouldn't be handled as such. */
886 if (DECL_COMMON (decl) && DECL_SECTION_NAME (decl) == NULL)
887 {
888 if (DECL_THREAD_LOCAL_P (decl))
889 return tls_comm_section;
890 if (TREE_PUBLIC (decl) && bss_initializer_p (decl))
891 return comm_section;
892 }
893
894 if (DECL_INITIAL (decl) == error_mark_node)
895 reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;
896 else if (DECL_INITIAL (decl))
897 reloc = compute_reloc_for_constant (DECL_INITIAL (decl));
898 else
899 reloc = 0;
900
901 resolve_unique_section (decl, reloc, flag_data_sections);
902 if (IN_NAMED_SECTION (decl))
903 return get_named_section (decl, NULL, reloc);
904
905 if (!DECL_THREAD_LOCAL_P (decl)
906 && !(prefer_noswitch_p && targetm.have_switchable_bss_sections)
907 && bss_initializer_p (decl))
908 {
909 if (!TREE_PUBLIC (decl))
910 return lcomm_section;
911 if (bss_noswitch_section)
912 return bss_noswitch_section;
913 }
914
915 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
916 }
917
918 /* Return the block into which object_block DECL should be placed. */
919
920 static struct object_block *
get_block_for_decl(tree decl)921 get_block_for_decl (tree decl)
922 {
923 section *sect;
924
925 if (TREE_CODE (decl) == VAR_DECL)
926 {
927 /* The object must be defined in this translation unit. */
928 if (DECL_EXTERNAL (decl))
929 return NULL;
930
931 /* There's no point using object blocks for something that is
932 isolated by definition. */
933 if (DECL_ONE_ONLY (decl))
934 return NULL;
935 }
936
937 /* We can only calculate block offsets if the decl has a known
938 constant size. */
939 if (DECL_SIZE_UNIT (decl) == NULL)
940 return NULL;
941 if (!host_integerp (DECL_SIZE_UNIT (decl), 1))
942 return NULL;
943
944 /* Find out which section should contain DECL. We cannot put it into
945 an object block if it requires a standalone definition. */
946 if (TREE_CODE (decl) == VAR_DECL)
947 align_variable (decl, 0);
948 sect = get_variable_section (decl, true);
949 if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
950 return NULL;
951
952 return get_block_for_section (sect);
953 }
954
955 /* Make sure block symbol SYMBOL is in block BLOCK. */
956
957 static void
change_symbol_block(rtx symbol,struct object_block * block)958 change_symbol_block (rtx symbol, struct object_block *block)
959 {
960 if (block != SYMBOL_REF_BLOCK (symbol))
961 {
962 gcc_assert (SYMBOL_REF_BLOCK_OFFSET (symbol) < 0);
963 SYMBOL_REF_BLOCK (symbol) = block;
964 }
965 }
966
967 /* Return true if it is possible to put DECL in an object_block. */
968
969 static bool
use_blocks_for_decl_p(tree decl)970 use_blocks_for_decl_p (tree decl)
971 {
972 /* Only data DECLs can be placed into object blocks. */
973 if (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != CONST_DECL)
974 return false;
975
976 /* Detect decls created by dw2_force_const_mem. Such decls are
977 special because DECL_INITIAL doesn't specify the decl's true value.
978 dw2_output_indirect_constants will instead call assemble_variable
979 with dont_output_data set to 1 and then print the contents itself. */
980 if (DECL_INITIAL (decl) == decl)
981 return false;
982
983 /* If this decl is an alias, then we don't want to emit a definition. */
984 if (lookup_attribute ("alias", DECL_ATTRIBUTES (decl)))
985 return false;
986
987 return true;
988 }
989
990 /* Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL should
991 have static storage duration. In other words, it should not be an
992 automatic variable, including PARM_DECLs.
993
994 There is, however, one exception: this function handles variables
995 explicitly placed in a particular register by the user.
996
997 This is never called for PARM_DECL nodes. */
998
999 void
make_decl_rtl(tree decl)1000 make_decl_rtl (tree decl)
1001 {
1002 const char *name = 0;
1003 int reg_number;
1004 rtx x;
1005
1006 /* Check that we are not being given an automatic variable. */
1007 gcc_assert (TREE_CODE (decl) != PARM_DECL
1008 && TREE_CODE (decl) != RESULT_DECL);
1009
1010 /* A weak alias has TREE_PUBLIC set but not the other bits. */
1011 gcc_assert (TREE_CODE (decl) != VAR_DECL
1012 || TREE_STATIC (decl)
1013 || TREE_PUBLIC (decl)
1014 || DECL_EXTERNAL (decl)
1015 || DECL_REGISTER (decl));
1016
1017 /* And that we were not given a type or a label. */
1018 gcc_assert (TREE_CODE (decl) != TYPE_DECL
1019 && TREE_CODE (decl) != LABEL_DECL);
1020
1021 /* For a duplicate declaration, we can be called twice on the
1022 same DECL node. Don't discard the RTL already made. */
1023 if (DECL_RTL_SET_P (decl))
1024 {
1025 /* If the old RTL had the wrong mode, fix the mode. */
1026 x = DECL_RTL (decl);
1027 if (GET_MODE (x) != DECL_MODE (decl))
1028 SET_DECL_RTL (decl, adjust_address_nv (x, DECL_MODE (decl), 0));
1029
1030 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1031 return;
1032
1033 /* ??? Another way to do this would be to maintain a hashed
1034 table of such critters. Instead of adding stuff to a DECL
1035 to give certain attributes to it, we could use an external
1036 hash map from DECL to set of attributes. */
1037
1038 /* Let the target reassign the RTL if it wants.
1039 This is necessary, for example, when one machine specific
1040 decl attribute overrides another. */
1041 targetm.encode_section_info (decl, DECL_RTL (decl), false);
1042
1043 /* If the symbol has a SYMBOL_REF_BLOCK field, update it based
1044 on the new decl information. */
1045 if (MEM_P (x)
1046 && GET_CODE (XEXP (x, 0)) == SYMBOL_REF
1047 && SYMBOL_REF_HAS_BLOCK_INFO_P (XEXP (x, 0)))
1048 change_symbol_block (XEXP (x, 0), get_block_for_decl (decl));
1049
1050 /* Make this function static known to the mudflap runtime. */
1051 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
1052 mudflap_enqueue_decl (decl);
1053
1054 return;
1055 }
1056
1057 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
1058
1059 if (name[0] != '*' && TREE_CODE (decl) != FUNCTION_DECL
1060 && DECL_REGISTER (decl))
1061 {
1062 error ("register name not specified for %q+D", decl);
1063 }
1064 else if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1065 {
1066 const char *asmspec = name+1;
1067 reg_number = decode_reg_name (asmspec);
1068 /* First detect errors in declaring global registers. */
1069 if (reg_number == -1)
1070 error ("register name not specified for %q+D", decl);
1071 else if (reg_number < 0)
1072 error ("invalid register name for %q+D", decl);
1073 else if (TYPE_MODE (TREE_TYPE (decl)) == BLKmode)
1074 error ("data type of %q+D isn%'t suitable for a register",
1075 decl);
1076 else if (! HARD_REGNO_MODE_OK (reg_number, TYPE_MODE (TREE_TYPE (decl))))
1077 error ("register specified for %q+D isn%'t suitable for data type",
1078 decl);
1079 /* Now handle properly declared static register variables. */
1080 else
1081 {
1082 int nregs;
1083
1084 if (DECL_INITIAL (decl) != 0 && TREE_STATIC (decl))
1085 {
1086 DECL_INITIAL (decl) = 0;
1087 error ("global register variable has initial value");
1088 }
1089 if (TREE_THIS_VOLATILE (decl))
1090 warning (OPT_Wvolatile_register_var,
1091 "optimization may eliminate reads and/or "
1092 "writes to register variables");
1093
1094 /* If the user specified one of the eliminables registers here,
1095 e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
1096 confused with that register and be eliminated. This usage is
1097 somewhat suspect... */
1098
1099 SET_DECL_RTL (decl, gen_rtx_raw_REG (DECL_MODE (decl), reg_number));
1100 ORIGINAL_REGNO (DECL_RTL (decl)) = reg_number;
1101 REG_USERVAR_P (DECL_RTL (decl)) = 1;
1102
1103 if (TREE_STATIC (decl))
1104 {
1105 /* Make this register global, so not usable for anything
1106 else. */
1107 #ifdef ASM_DECLARE_REGISTER_GLOBAL
1108 name = IDENTIFIER_POINTER (DECL_NAME (decl));
1109 ASM_DECLARE_REGISTER_GLOBAL (asm_out_file, decl, reg_number, name);
1110 #endif
1111 nregs = hard_regno_nregs[reg_number][DECL_MODE (decl)];
1112 while (nregs > 0)
1113 globalize_reg (reg_number + --nregs);
1114 }
1115
1116 /* As a register variable, it has no section. */
1117 return;
1118 }
1119 }
1120 /* Now handle ordinary static variables and functions (in memory).
1121 Also handle vars declared register invalidly. */
1122 else if (name[0] == '*')
1123 {
1124 #ifdef REGISTER_PREFIX
1125 if (strlen (REGISTER_PREFIX) != 0)
1126 {
1127 reg_number = decode_reg_name (name);
1128 if (reg_number >= 0 || reg_number == -3)
1129 error ("register name given for non-register variable %q+D", decl);
1130 }
1131 #endif
1132 }
1133
1134 /* Specifying a section attribute on a variable forces it into a
1135 non-.bss section, and thus it cannot be common. */
1136 if (TREE_CODE (decl) == VAR_DECL
1137 && DECL_SECTION_NAME (decl) != NULL_TREE
1138 && DECL_INITIAL (decl) == NULL_TREE
1139 && DECL_COMMON (decl))
1140 DECL_COMMON (decl) = 0;
1141
1142 /* Variables can't be both common and weak. */
1143 if (TREE_CODE (decl) == VAR_DECL && DECL_WEAK (decl))
1144 DECL_COMMON (decl) = 0;
1145
1146 if (use_object_blocks_p () && use_blocks_for_decl_p (decl))
1147 x = create_block_symbol (name, get_block_for_decl (decl), -1);
1148 else
1149 x = gen_rtx_SYMBOL_REF (Pmode, name);
1150 SYMBOL_REF_WEAK (x) = DECL_WEAK (decl);
1151 SET_SYMBOL_REF_DECL (x, decl);
1152
1153 x = gen_rtx_MEM (DECL_MODE (decl), x);
1154 if (TREE_CODE (decl) != FUNCTION_DECL)
1155 set_mem_attributes (x, decl, 1);
1156 SET_DECL_RTL (decl, x);
1157
1158 /* Optionally set flags or add text to the name to record information
1159 such as that it is a function name.
1160 If the name is changed, the macro ASM_OUTPUT_LABELREF
1161 will have to know how to strip this information. */
1162 targetm.encode_section_info (decl, DECL_RTL (decl), true);
1163
1164 /* Make this function static known to the mudflap runtime. */
1165 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
1166 mudflap_enqueue_decl (decl);
1167 }
1168
1169 /* Output a string of literal assembler code
1170 for an `asm' keyword used between functions. */
1171
1172 void
assemble_asm(tree string)1173 assemble_asm (tree string)
1174 {
1175 app_enable ();
1176
1177 if (TREE_CODE (string) == ADDR_EXPR)
1178 string = TREE_OPERAND (string, 0);
1179
1180 fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string));
1181 }
1182
1183 /* Record an element in the table of global destructors. SYMBOL is
1184 a SYMBOL_REF of the function to be called; PRIORITY is a number
1185 between 0 and MAX_INIT_PRIORITY. */
1186
1187 void
default_stabs_asm_out_destructor(rtx symbol ATTRIBUTE_UNUSED,int priority ATTRIBUTE_UNUSED)1188 default_stabs_asm_out_destructor (rtx symbol ATTRIBUTE_UNUSED,
1189 int priority ATTRIBUTE_UNUSED)
1190 {
1191 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1192 /* Tell GNU LD that this is part of the static destructor set.
1193 This will work for any system that uses stabs, most usefully
1194 aout systems. */
1195 dbxout_begin_simple_stabs ("___DTOR_LIST__", 22 /* N_SETT */);
1196 dbxout_stab_value_label (XSTR (symbol, 0));
1197 #else
1198 sorry ("global destructors not supported on this target");
1199 #endif
1200 }
1201
1202 void
default_named_section_asm_out_destructor(rtx symbol,int priority)1203 default_named_section_asm_out_destructor (rtx symbol, int priority)
1204 {
1205 const char *section = ".dtors";
1206 char buf[16];
1207
1208 /* ??? This only works reliably with the GNU linker. */
1209 if (priority != DEFAULT_INIT_PRIORITY)
1210 {
1211 sprintf (buf, ".dtors.%.5u",
1212 /* Invert the numbering so the linker puts us in the proper
1213 order; constructors are run from right to left, and the
1214 linker sorts in increasing order. */
1215 MAX_INIT_PRIORITY - priority);
1216 section = buf;
1217 }
1218
1219 switch_to_section (get_section (section, SECTION_WRITE, NULL));
1220 assemble_align (POINTER_SIZE);
1221 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1222 }
1223
1224 #ifdef DTORS_SECTION_ASM_OP
1225 void
default_dtor_section_asm_out_destructor(rtx symbol,int priority ATTRIBUTE_UNUSED)1226 default_dtor_section_asm_out_destructor (rtx symbol,
1227 int priority ATTRIBUTE_UNUSED)
1228 {
1229 switch_to_section (dtors_section);
1230 assemble_align (POINTER_SIZE);
1231 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1232 }
1233 #endif
1234
1235 /* Likewise for global constructors. */
1236
1237 void
default_stabs_asm_out_constructor(rtx symbol ATTRIBUTE_UNUSED,int priority ATTRIBUTE_UNUSED)1238 default_stabs_asm_out_constructor (rtx symbol ATTRIBUTE_UNUSED,
1239 int priority ATTRIBUTE_UNUSED)
1240 {
1241 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1242 /* Tell GNU LD that this is part of the static destructor set.
1243 This will work for any system that uses stabs, most usefully
1244 aout systems. */
1245 dbxout_begin_simple_stabs ("___CTOR_LIST__", 22 /* N_SETT */);
1246 dbxout_stab_value_label (XSTR (symbol, 0));
1247 #else
1248 sorry ("global constructors not supported on this target");
1249 #endif
1250 }
1251
1252 void
default_named_section_asm_out_constructor(rtx symbol,int priority)1253 default_named_section_asm_out_constructor (rtx symbol, int priority)
1254 {
1255 const char *section = ".ctors";
1256 char buf[16];
1257
1258 /* ??? This only works reliably with the GNU linker. */
1259 if (priority != DEFAULT_INIT_PRIORITY)
1260 {
1261 sprintf (buf, ".ctors.%.5u",
1262 /* Invert the numbering so the linker puts us in the proper
1263 order; constructors are run from right to left, and the
1264 linker sorts in increasing order. */
1265 MAX_INIT_PRIORITY - priority);
1266 section = buf;
1267 }
1268
1269 switch_to_section (get_section (section, SECTION_WRITE, NULL));
1270 assemble_align (POINTER_SIZE);
1271 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1272 }
1273
1274 #ifdef CTORS_SECTION_ASM_OP
1275 void
default_ctor_section_asm_out_constructor(rtx symbol,int priority ATTRIBUTE_UNUSED)1276 default_ctor_section_asm_out_constructor (rtx symbol,
1277 int priority ATTRIBUTE_UNUSED)
1278 {
1279 switch_to_section (ctors_section);
1280 assemble_align (POINTER_SIZE);
1281 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1282 }
1283 #endif
1284
1285 /* CONSTANT_POOL_BEFORE_FUNCTION may be defined as an expression with
1286 a nonzero value if the constant pool should be output before the
1287 start of the function, or a zero value if the pool should output
1288 after the end of the function. The default is to put it before the
1289 start. */
1290
1291 #ifndef CONSTANT_POOL_BEFORE_FUNCTION
1292 #define CONSTANT_POOL_BEFORE_FUNCTION 1
1293 #endif
1294
1295 /* DECL is an object (either VAR_DECL or FUNCTION_DECL) which is going
1296 to be output to assembler.
1297 Set first_global_object_name and weak_global_object_name as appropriate. */
1298
1299 void
notice_global_symbol(tree decl)1300 notice_global_symbol (tree decl)
1301 {
1302 const char **type = &first_global_object_name;
1303
1304 if (first_global_object_name
1305 || !TREE_PUBLIC (decl)
1306 || DECL_EXTERNAL (decl)
1307 || !DECL_NAME (decl)
1308 || (TREE_CODE (decl) != FUNCTION_DECL
1309 && (TREE_CODE (decl) != VAR_DECL
1310 || (DECL_COMMON (decl)
1311 && (DECL_INITIAL (decl) == 0
1312 || DECL_INITIAL (decl) == error_mark_node))))
1313 || !MEM_P (DECL_RTL (decl)))
1314 return;
1315
1316 /* We win when global object is found, but it is useful to know about weak
1317 symbol as well so we can produce nicer unique names. */
1318 if (DECL_WEAK (decl) || DECL_ONE_ONLY (decl))
1319 type = &weak_global_object_name;
1320
1321 if (!*type)
1322 {
1323 const char *p;
1324 const char *name;
1325 rtx decl_rtl = DECL_RTL (decl);
1326
1327 p = targetm.strip_name_encoding (XSTR (XEXP (decl_rtl, 0), 0));
1328 name = ggc_strdup (p);
1329
1330 *type = name;
1331 }
1332 }
1333
1334 /* Output assembler code for the constant pool of a function and associated
1335 with defining the name of the function. DECL describes the function.
1336 NAME is the function's name. For the constant pool, we use the current
1337 constant pool data. */
1338
1339 void
assemble_start_function(tree decl,const char * fnname)1340 assemble_start_function (tree decl, const char *fnname)
1341 {
1342 int align;
1343 char tmp_label[100];
1344 bool hot_label_written = false;
1345
1346 cfun->unlikely_text_section_name = NULL;
1347
1348 first_function_block_is_cold = false;
1349 if (flag_reorder_blocks_and_partition)
1350 {
1351 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTB", const_labelno);
1352 cfun->hot_section_label = ggc_strdup (tmp_label);
1353 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDB", const_labelno);
1354 cfun->cold_section_label = ggc_strdup (tmp_label);
1355 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTE", const_labelno);
1356 cfun->hot_section_end_label = ggc_strdup (tmp_label);
1357 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDE", const_labelno);
1358 cfun->cold_section_end_label = ggc_strdup (tmp_label);
1359 const_labelno++;
1360 }
1361 else
1362 {
1363 cfun->hot_section_label = NULL;
1364 cfun->cold_section_label = NULL;
1365 cfun->hot_section_end_label = NULL;
1366 cfun->cold_section_end_label = NULL;
1367 }
1368
1369 /* The following code does not need preprocessing in the assembler. */
1370
1371 app_disable ();
1372
1373 if (CONSTANT_POOL_BEFORE_FUNCTION)
1374 output_constant_pool (fnname, decl);
1375
1376 resolve_unique_section (decl, 0, flag_function_sections);
1377
1378 /* Make sure the not and cold text (code) sections are properly
1379 aligned. This is necessary here in the case where the function
1380 has both hot and cold sections, because we don't want to re-set
1381 the alignment when the section switch happens mid-function. */
1382
1383 if (flag_reorder_blocks_and_partition)
1384 {
1385 switch_to_section (unlikely_text_section ());
1386 assemble_align (FUNCTION_BOUNDARY);
1387 ASM_OUTPUT_LABEL (asm_out_file, cfun->cold_section_label);
1388
1389 /* When the function starts with a cold section, we need to explicitly
1390 align the hot section and write out the hot section label.
1391 But if the current function is a thunk, we do not have a CFG. */
1392 if (!current_function_is_thunk
1393 && BB_PARTITION (ENTRY_BLOCK_PTR->next_bb) == BB_COLD_PARTITION)
1394 {
1395 switch_to_section (text_section);
1396 assemble_align (FUNCTION_BOUNDARY);
1397 ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_label);
1398 hot_label_written = true;
1399 first_function_block_is_cold = true;
1400 }
1401 }
1402 else if (DECL_SECTION_NAME (decl))
1403 {
1404 /* Calls to function_section rely on first_function_block_is_cold
1405 being accurate. The first block may be cold even if we aren't
1406 doing partitioning, if the entire function was decided by
1407 choose_function_section (predict.c) to be cold. */
1408
1409 initialize_cold_section_name ();
1410
1411 if (cfun->unlikely_text_section_name
1412 && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
1413 cfun->unlikely_text_section_name) == 0)
1414 first_function_block_is_cold = true;
1415 }
1416
1417 in_cold_section_p = first_function_block_is_cold;
1418
1419 /* Switch to the correct text section for the start of the function. */
1420
1421 switch_to_section (function_section (decl));
1422 if (flag_reorder_blocks_and_partition
1423 && !hot_label_written)
1424 ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_label);
1425
1426 /* Tell assembler to move to target machine's alignment for functions. */
1427 align = floor_log2 (FUNCTION_BOUNDARY / BITS_PER_UNIT);
1428 if (align < force_align_functions_log)
1429 align = force_align_functions_log;
1430 if (align > 0)
1431 {
1432 ASM_OUTPUT_ALIGN (asm_out_file, align);
1433 }
1434
1435 /* Handle a user-specified function alignment.
1436 Note that we still need to align to FUNCTION_BOUNDARY, as above,
1437 because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */
1438 if (align_functions_log > align
1439 && cfun->function_frequency != FUNCTION_FREQUENCY_UNLIKELY_EXECUTED)
1440 {
1441 #ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
1442 ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file,
1443 align_functions_log, align_functions - 1);
1444 #else
1445 ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log);
1446 #endif
1447 }
1448
1449 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
1450 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
1451 #endif
1452
1453 (*debug_hooks->begin_function) (decl);
1454
1455 /* Make function name accessible from other files, if appropriate. */
1456
1457 if (TREE_PUBLIC (decl))
1458 {
1459 notice_global_symbol (decl);
1460
1461 globalize_decl (decl);
1462
1463 maybe_assemble_visibility (decl);
1464 }
1465
1466 if (DECL_PRESERVE_P (decl))
1467 targetm.asm_out.mark_decl_preserved (fnname);
1468
1469 /* Do any machine/system dependent processing of the function name. */
1470 #ifdef ASM_DECLARE_FUNCTION_NAME
1471 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
1472 #else
1473 /* Standard thing is just output label for the function. */
1474 ASM_OUTPUT_LABEL (asm_out_file, fnname);
1475 #endif /* ASM_DECLARE_FUNCTION_NAME */
1476 }
1477
1478 /* Output assembler code associated with defining the size of the
1479 function. DECL describes the function. NAME is the function's name. */
1480
1481 void
assemble_end_function(tree decl,const char * fnname ATTRIBUTE_UNUSED)1482 assemble_end_function (tree decl, const char *fnname ATTRIBUTE_UNUSED)
1483 {
1484 #ifdef ASM_DECLARE_FUNCTION_SIZE
1485 /* We could have switched section in the middle of the function. */
1486 if (flag_reorder_blocks_and_partition)
1487 switch_to_section (function_section (decl));
1488 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
1489 #endif
1490 if (! CONSTANT_POOL_BEFORE_FUNCTION)
1491 {
1492 output_constant_pool (fnname, decl);
1493 switch_to_section (function_section (decl)); /* need to switch back */
1494 }
1495 /* Output labels for end of hot/cold text sections (to be used by
1496 debug info.) */
1497 if (flag_reorder_blocks_and_partition)
1498 {
1499 section *save_text_section;
1500
1501 save_text_section = in_section;
1502 switch_to_section (unlikely_text_section ());
1503 ASM_OUTPUT_LABEL (asm_out_file, cfun->cold_section_end_label);
1504 if (first_function_block_is_cold)
1505 switch_to_section (text_section);
1506 else
1507 switch_to_section (function_section (decl));
1508 ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_end_label);
1509 switch_to_section (save_text_section);
1510 }
1511 }
1512
1513 /* Assemble code to leave SIZE bytes of zeros. */
1514
1515 void
assemble_zeros(unsigned HOST_WIDE_INT size)1516 assemble_zeros (unsigned HOST_WIDE_INT size)
1517 {
1518 /* Do no output if -fsyntax-only. */
1519 if (flag_syntax_only)
1520 return;
1521
1522 #ifdef ASM_NO_SKIP_IN_TEXT
1523 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
1524 so we must output 0s explicitly in the text section. */
1525 if (ASM_NO_SKIP_IN_TEXT && (in_section->common.flags & SECTION_CODE) != 0)
1526 {
1527 unsigned HOST_WIDE_INT i;
1528 for (i = 0; i < size; i++)
1529 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1);
1530 }
1531 else
1532 #endif
1533 if (size > 0)
1534 ASM_OUTPUT_SKIP (asm_out_file, size);
1535 }
1536
1537 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
1538
1539 void
assemble_align(int align)1540 assemble_align (int align)
1541 {
1542 if (align > BITS_PER_UNIT)
1543 {
1544 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1545 }
1546 }
1547
1548 /* Assemble a string constant with the specified C string as contents. */
1549
1550 void
assemble_string(const char * p,int size)1551 assemble_string (const char *p, int size)
1552 {
1553 int pos = 0;
1554 int maximum = 2000;
1555
1556 /* If the string is very long, split it up. */
1557
1558 while (pos < size)
1559 {
1560 int thissize = size - pos;
1561 if (thissize > maximum)
1562 thissize = maximum;
1563
1564 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
1565
1566 pos += thissize;
1567 p += thissize;
1568 }
1569 }
1570
1571
1572 /* A noswitch_section_callback for lcomm_section. */
1573
1574 static bool
emit_local(tree decl ATTRIBUTE_UNUSED,const char * name ATTRIBUTE_UNUSED,unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)1575 emit_local (tree decl ATTRIBUTE_UNUSED,
1576 const char *name ATTRIBUTE_UNUSED,
1577 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1578 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1579 {
1580 #if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL
1581 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name,
1582 size, DECL_ALIGN (decl));
1583 return true;
1584 #elif defined ASM_OUTPUT_ALIGNED_LOCAL
1585 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl));
1586 return true;
1587 #else
1588 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1589 return false;
1590 #endif
1591 }
1592
1593 /* A noswitch_section_callback for bss_noswitch_section. */
1594
1595 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
1596 static bool
emit_bss(tree decl ATTRIBUTE_UNUSED,const char * name ATTRIBUTE_UNUSED,unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)1597 emit_bss (tree decl ATTRIBUTE_UNUSED,
1598 const char *name ATTRIBUTE_UNUSED,
1599 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1600 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1601 {
1602 #if defined ASM_OUTPUT_ALIGNED_BSS
1603 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl));
1604 return true;
1605 #else
1606 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded);
1607 return false;
1608 #endif
1609 }
1610 #endif
1611
1612 /* A noswitch_section_callback for comm_section. */
1613
1614 static bool
emit_common(tree decl ATTRIBUTE_UNUSED,const char * name ATTRIBUTE_UNUSED,unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)1615 emit_common (tree decl ATTRIBUTE_UNUSED,
1616 const char *name ATTRIBUTE_UNUSED,
1617 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1618 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1619 {
1620 #if defined ASM_OUTPUT_ALIGNED_DECL_COMMON
1621 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name,
1622 size, DECL_ALIGN (decl));
1623 return true;
1624 #elif defined ASM_OUTPUT_ALIGNED_COMMON
1625 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl));
1626 return true;
1627 #else
1628 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded);
1629 return false;
1630 #endif
1631 }
1632
1633 /* A noswitch_section_callback for tls_comm_section. */
1634
1635 static bool
emit_tls_common(tree decl ATTRIBUTE_UNUSED,const char * name ATTRIBUTE_UNUSED,unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)1636 emit_tls_common (tree decl ATTRIBUTE_UNUSED,
1637 const char *name ATTRIBUTE_UNUSED,
1638 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1639 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1640 {
1641 #ifdef ASM_OUTPUT_TLS_COMMON
1642 ASM_OUTPUT_TLS_COMMON (asm_out_file, decl, name, size);
1643 return true;
1644 #else
1645 sorry ("thread-local COMMON data not implemented");
1646 return true;
1647 #endif
1648 }
1649
1650 /* Assemble DECL given that it belongs in SECTION_NOSWITCH section SECT.
1651 NAME is the name of DECL's SYMBOL_REF. */
1652
1653 static void
assemble_noswitch_variable(tree decl,const char * name,section * sect)1654 assemble_noswitch_variable (tree decl, const char *name, section *sect)
1655 {
1656 unsigned HOST_WIDE_INT size, rounded;
1657
1658 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
1659 rounded = size;
1660
1661 /* Don't allocate zero bytes of common,
1662 since that means "undefined external" in the linker. */
1663 if (size == 0)
1664 rounded = 1;
1665
1666 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1667 so that each uninitialized object starts on such a boundary. */
1668 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
1669 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1670 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1671
1672 if (!sect->noswitch.callback (decl, name, size, rounded)
1673 && (unsigned HOST_WIDE_INT) DECL_ALIGN_UNIT (decl) > rounded)
1674 warning (0, "requested alignment for %q+D is greater than "
1675 "implemented alignment of %wu", decl, rounded);
1676 }
1677
1678 /* A subroutine of assemble_variable. Output the label and contents of
1679 DECL, whose address is a SYMBOL_REF with name NAME. DONT_OUTPUT_DATA
1680 is as for assemble_variable. */
1681
1682 static void
assemble_variable_contents(tree decl,const char * name,bool dont_output_data)1683 assemble_variable_contents (tree decl, const char *name,
1684 bool dont_output_data)
1685 {
1686 /* Do any machine/system dependent processing of the object. */
1687 #ifdef ASM_DECLARE_OBJECT_NAME
1688 last_assemble_variable_decl = decl;
1689 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
1690 #else
1691 /* Standard thing is just output label for the object. */
1692 ASM_OUTPUT_LABEL (asm_out_file, name);
1693 #endif /* ASM_DECLARE_OBJECT_NAME */
1694
1695 if (!dont_output_data)
1696 {
1697 if (DECL_INITIAL (decl)
1698 && DECL_INITIAL (decl) != error_mark_node
1699 && !initializer_zerop (DECL_INITIAL (decl)))
1700 /* Output the actual data. */
1701 output_constant (DECL_INITIAL (decl),
1702 tree_low_cst (DECL_SIZE_UNIT (decl), 1),
1703 DECL_ALIGN (decl));
1704 else
1705 /* Leave space for it. */
1706 assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1));
1707 }
1708 }
1709
1710 /* Assemble everything that is needed for a variable or function declaration.
1711 Not used for automatic variables, and not used for function definitions.
1712 Should not be called for variables of incomplete structure type.
1713
1714 TOP_LEVEL is nonzero if this variable has file scope.
1715 AT_END is nonzero if this is the special handling, at end of compilation,
1716 to define things that have had only tentative definitions.
1717 DONT_OUTPUT_DATA if nonzero means don't actually output the
1718 initial value (that will be done by the caller). */
1719
1720 void
assemble_variable(tree decl,int top_level ATTRIBUTE_UNUSED,int at_end ATTRIBUTE_UNUSED,int dont_output_data)1721 assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED,
1722 int at_end ATTRIBUTE_UNUSED, int dont_output_data)
1723 {
1724 const char *name;
1725 rtx decl_rtl, symbol;
1726 section *sect;
1727
1728 if (lang_hooks.decls.prepare_assemble_variable)
1729 lang_hooks.decls.prepare_assemble_variable (decl);
1730
1731 last_assemble_variable_decl = 0;
1732
1733 /* Normally no need to say anything here for external references,
1734 since assemble_external is called by the language-specific code
1735 when a declaration is first seen. */
1736
1737 if (DECL_EXTERNAL (decl))
1738 return;
1739
1740 /* Output no assembler code for a function declaration.
1741 Only definitions of functions output anything. */
1742
1743 if (TREE_CODE (decl) == FUNCTION_DECL)
1744 return;
1745
1746 /* Do nothing for global register variables. */
1747 if (DECL_RTL_SET_P (decl) && REG_P (DECL_RTL (decl)))
1748 {
1749 TREE_ASM_WRITTEN (decl) = 1;
1750 return;
1751 }
1752
1753 /* If type was incomplete when the variable was declared,
1754 see if it is complete now. */
1755
1756 if (DECL_SIZE (decl) == 0)
1757 layout_decl (decl, 0);
1758
1759 /* Still incomplete => don't allocate it; treat the tentative defn
1760 (which is what it must have been) as an `extern' reference. */
1761
1762 if (!dont_output_data && DECL_SIZE (decl) == 0)
1763 {
1764 error ("storage size of %q+D isn%'t known", decl);
1765 TREE_ASM_WRITTEN (decl) = 1;
1766 return;
1767 }
1768
1769 /* The first declaration of a variable that comes through this function
1770 decides whether it is global (in C, has external linkage)
1771 or local (in C, has internal linkage). So do nothing more
1772 if this function has already run. */
1773
1774 if (TREE_ASM_WRITTEN (decl))
1775 return;
1776
1777 /* Make sure targetm.encode_section_info is invoked before we set
1778 ASM_WRITTEN. */
1779 decl_rtl = DECL_RTL (decl);
1780
1781 TREE_ASM_WRITTEN (decl) = 1;
1782
1783 /* Do no output if -fsyntax-only. */
1784 if (flag_syntax_only)
1785 return;
1786
1787 app_disable ();
1788
1789 if (! dont_output_data
1790 && ! host_integerp (DECL_SIZE_UNIT (decl), 1))
1791 {
1792 error ("size of variable %q+D is too large", decl);
1793 return;
1794 }
1795
1796 gcc_assert (MEM_P (decl_rtl));
1797 gcc_assert (GET_CODE (XEXP (decl_rtl, 0)) == SYMBOL_REF);
1798 symbol = XEXP (decl_rtl, 0);
1799 name = XSTR (symbol, 0);
1800 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
1801 notice_global_symbol (decl);
1802
1803 /* Compute the alignment of this data. */
1804
1805 align_variable (decl, dont_output_data);
1806 set_mem_align (decl_rtl, DECL_ALIGN (decl));
1807
1808 if (TREE_PUBLIC (decl))
1809 maybe_assemble_visibility (decl);
1810
1811 if (DECL_PRESERVE_P (decl))
1812 targetm.asm_out.mark_decl_preserved (name);
1813
1814 /* First make the assembler name(s) global if appropriate. */
1815 sect = get_variable_section (decl, false);
1816 if (TREE_PUBLIC (decl)
1817 && DECL_NAME (decl)
1818 && (sect->common.flags & SECTION_COMMON) == 0)
1819 globalize_decl (decl);
1820
1821 /* Output any data that we will need to use the address of. */
1822 if (DECL_INITIAL (decl) && DECL_INITIAL (decl) != error_mark_node)
1823 output_addressed_constants (DECL_INITIAL (decl));
1824
1825 /* dbxout.c needs to know this. */
1826 if (sect && (sect->common.flags & SECTION_CODE) != 0)
1827 DECL_IN_TEXT_SECTION (decl) = 1;
1828
1829 /* If the decl is part of an object_block, make sure that the decl
1830 has been positioned within its block, but do not write out its
1831 definition yet. output_object_blocks will do that later. */
1832 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
1833 {
1834 gcc_assert (!dont_output_data);
1835 place_block_symbol (symbol);
1836 }
1837 else if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
1838 assemble_noswitch_variable (decl, name, sect);
1839 else
1840 {
1841 switch_to_section (sect);
1842 if (DECL_ALIGN (decl) > BITS_PER_UNIT)
1843 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (DECL_ALIGN_UNIT (decl)));
1844 assemble_variable_contents (decl, name, dont_output_data);
1845 }
1846 }
1847
1848 /* Return 1 if type TYPE contains any pointers. */
1849
1850 static int
contains_pointers_p(tree type)1851 contains_pointers_p (tree type)
1852 {
1853 switch (TREE_CODE (type))
1854 {
1855 case POINTER_TYPE:
1856 case REFERENCE_TYPE:
1857 /* I'm not sure whether OFFSET_TYPE needs this treatment,
1858 so I'll play safe and return 1. */
1859 case OFFSET_TYPE:
1860 return 1;
1861
1862 case RECORD_TYPE:
1863 case UNION_TYPE:
1864 case QUAL_UNION_TYPE:
1865 {
1866 tree fields;
1867 /* For a type that has fields, see if the fields have pointers. */
1868 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
1869 if (TREE_CODE (fields) == FIELD_DECL
1870 && contains_pointers_p (TREE_TYPE (fields)))
1871 return 1;
1872 return 0;
1873 }
1874
1875 case ARRAY_TYPE:
1876 /* An array type contains pointers if its element type does. */
1877 return contains_pointers_p (TREE_TYPE (type));
1878
1879 default:
1880 return 0;
1881 }
1882 }
1883
1884 /* In unit-at-a-time mode, we delay assemble_external processing until
1885 the compilation unit is finalized. This is the best we can do for
1886 right now (i.e. stage 3 of GCC 4.0) - the right thing is to delay
1887 it all the way to final. See PR 17982 for further discussion. */
1888 static GTY(()) tree pending_assemble_externals;
1889
1890 #ifdef ASM_OUTPUT_EXTERNAL
1891 /* True if DECL is a function decl for which no out-of-line copy exists.
1892 It is assumed that DECL's assembler name has been set. */
1893
1894 static bool
incorporeal_function_p(tree decl)1895 incorporeal_function_p (tree decl)
1896 {
1897 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
1898 {
1899 const char *name;
1900
1901 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
1902 && DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA)
1903 return true;
1904
1905 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
1906 if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
1907 return true;
1908 }
1909 return false;
1910 }
1911
1912 /* Actually do the tests to determine if this is necessary, and invoke
1913 ASM_OUTPUT_EXTERNAL. */
1914 static void
assemble_external_real(tree decl)1915 assemble_external_real (tree decl)
1916 {
1917 rtx rtl = DECL_RTL (decl);
1918
1919 if (MEM_P (rtl) && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
1920 && !SYMBOL_REF_USED (XEXP (rtl, 0))
1921 && !incorporeal_function_p (decl))
1922 {
1923 /* Some systems do require some output. */
1924 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
1925 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
1926 }
1927 }
1928 #endif
1929
1930 void
process_pending_assemble_externals(void)1931 process_pending_assemble_externals (void)
1932 {
1933 #ifdef ASM_OUTPUT_EXTERNAL
1934 tree list;
1935 for (list = pending_assemble_externals; list; list = TREE_CHAIN (list))
1936 assemble_external_real (TREE_VALUE (list));
1937
1938 pending_assemble_externals = 0;
1939 #endif
1940 }
1941
1942 /* Output something to declare an external symbol to the assembler.
1943 (Most assemblers don't need this, so we normally output nothing.)
1944 Do nothing if DECL is not external. */
1945
1946 void
assemble_external(tree decl ATTRIBUTE_UNUSED)1947 assemble_external (tree decl ATTRIBUTE_UNUSED)
1948 {
1949 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the
1950 main body of this code is only rarely exercised. To provide some
1951 testing, on all platforms, we make sure that the ASM_OUT_FILE is
1952 open. If it's not, we should not be calling this function. */
1953 gcc_assert (asm_out_file);
1954
1955 #ifdef ASM_OUTPUT_EXTERNAL
1956 if (!DECL_P (decl) || !DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl))
1957 return;
1958
1959 /* We want to output external symbols at very last to check if they
1960 are references or not. */
1961 pending_assemble_externals = tree_cons (0, decl,
1962 pending_assemble_externals);
1963 #endif
1964 }
1965
1966 /* Similar, for calling a library function FUN. */
1967
1968 void
assemble_external_libcall(rtx fun)1969 assemble_external_libcall (rtx fun)
1970 {
1971 /* Declare library function name external when first used, if nec. */
1972 if (! SYMBOL_REF_USED (fun))
1973 {
1974 SYMBOL_REF_USED (fun) = 1;
1975 targetm.asm_out.external_libcall (fun);
1976 }
1977 }
1978
1979 /* Assemble a label named NAME. */
1980
1981 void
assemble_label(const char * name)1982 assemble_label (const char *name)
1983 {
1984 ASM_OUTPUT_LABEL (asm_out_file, name);
1985 }
1986
1987 /* Set the symbol_referenced flag for ID. */
1988 void
mark_referenced(tree id)1989 mark_referenced (tree id)
1990 {
1991 TREE_SYMBOL_REFERENCED (id) = 1;
1992 }
1993
1994 /* Set the symbol_referenced flag for DECL and notify callgraph. */
1995 void
mark_decl_referenced(tree decl)1996 mark_decl_referenced (tree decl)
1997 {
1998 if (TREE_CODE (decl) == FUNCTION_DECL)
1999 {
2000 /* Extern inline functions don't become needed when referenced.
2001 If we know a method will be emitted in other TU and no new
2002 functions can be marked reachable, just use the external
2003 definition. */
2004 struct cgraph_node *node = cgraph_node (decl);
2005 if (!DECL_EXTERNAL (decl)
2006 && (!node->local.vtable_method || !cgraph_global_info_ready
2007 || !node->local.finalized))
2008 cgraph_mark_needed_node (node);
2009 }
2010 else if (TREE_CODE (decl) == VAR_DECL)
2011 {
2012 struct cgraph_varpool_node *node = cgraph_varpool_node (decl);
2013 cgraph_varpool_mark_needed_node (node);
2014 /* C++ frontend use mark_decl_references to force COMDAT variables
2015 to be output that might appear dead otherwise. */
2016 node->force_output = true;
2017 }
2018 /* else do nothing - we can get various sorts of CST nodes here,
2019 which do not need to be marked. */
2020 }
2021
2022
2023 /* Follow the IDENTIFIER_TRANSPARENT_ALIAS chain starting at *ALIAS
2024 until we find an identifier that is not itself a transparent alias.
2025 Modify the alias passed to it by reference (and all aliases on the
2026 way to the ultimate target), such that they do not have to be
2027 followed again, and return the ultimate target of the alias
2028 chain. */
2029
2030 static inline tree
ultimate_transparent_alias_target(tree * alias)2031 ultimate_transparent_alias_target (tree *alias)
2032 {
2033 tree target = *alias;
2034
2035 if (IDENTIFIER_TRANSPARENT_ALIAS (target))
2036 {
2037 gcc_assert (TREE_CHAIN (target));
2038 target = ultimate_transparent_alias_target (&TREE_CHAIN (target));
2039 gcc_assert (! IDENTIFIER_TRANSPARENT_ALIAS (target)
2040 && ! TREE_CHAIN (target));
2041 *alias = target;
2042 }
2043
2044 return target;
2045 }
2046
2047 /* Output to FILE (an assembly file) a reference to NAME. If NAME
2048 starts with a *, the rest of NAME is output verbatim. Otherwise
2049 NAME is transformed in a target-specific way (usually by the
2050 addition of an underscore). */
2051
2052 void
assemble_name_raw(FILE * file,const char * name)2053 assemble_name_raw (FILE *file, const char *name)
2054 {
2055 if (name[0] == '*')
2056 fputs (&name[1], file);
2057 else
2058 ASM_OUTPUT_LABELREF (file, name);
2059 }
2060
2061 /* Like assemble_name_raw, but should be used when NAME might refer to
2062 an entity that is also represented as a tree (like a function or
2063 variable). If NAME does refer to such an entity, that entity will
2064 be marked as referenced. */
2065
2066 void
assemble_name(FILE * file,const char * name)2067 assemble_name (FILE *file, const char *name)
2068 {
2069 const char *real_name;
2070 tree id;
2071
2072 real_name = targetm.strip_name_encoding (name);
2073
2074 id = maybe_get_identifier (real_name);
2075 if (id)
2076 {
2077 tree id_orig = id;
2078
2079 mark_referenced (id);
2080 ultimate_transparent_alias_target (&id);
2081 if (id != id_orig)
2082 name = IDENTIFIER_POINTER (id);
2083 gcc_assert (! TREE_CHAIN (id));
2084 }
2085
2086 assemble_name_raw (file, name);
2087 }
2088
2089 /* Allocate SIZE bytes writable static space with a gensym name
2090 and return an RTX to refer to its address. */
2091
2092 rtx
assemble_static_space(unsigned HOST_WIDE_INT size)2093 assemble_static_space (unsigned HOST_WIDE_INT size)
2094 {
2095 char name[12];
2096 const char *namestring;
2097 rtx x;
2098
2099 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
2100 ++const_labelno;
2101 namestring = ggc_strdup (name);
2102
2103 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
2104 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL;
2105
2106 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
2107 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
2108 BIGGEST_ALIGNMENT);
2109 #else
2110 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
2111 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
2112 #else
2113 {
2114 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
2115 so that each uninitialized object starts on such a boundary. */
2116 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */
2117 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED
2118 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
2119 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
2120 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
2121 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
2122 }
2123 #endif
2124 #endif
2125 return x;
2126 }
2127
2128 /* Assemble the static constant template for function entry trampolines.
2129 This is done at most once per compilation.
2130 Returns an RTX for the address of the template. */
2131
2132 static GTY(()) rtx initial_trampoline;
2133
2134 #ifdef TRAMPOLINE_TEMPLATE
2135 rtx
assemble_trampoline_template(void)2136 assemble_trampoline_template (void)
2137 {
2138 char label[256];
2139 const char *name;
2140 int align;
2141 rtx symbol;
2142
2143 if (initial_trampoline)
2144 return initial_trampoline;
2145
2146 /* By default, put trampoline templates in read-only data section. */
2147
2148 #ifdef TRAMPOLINE_SECTION
2149 switch_to_section (TRAMPOLINE_SECTION);
2150 #else
2151 switch_to_section (readonly_data_section);
2152 #endif
2153
2154 /* Write the assembler code to define one. */
2155 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
2156 if (align > 0)
2157 {
2158 ASM_OUTPUT_ALIGN (asm_out_file, align);
2159 }
2160
2161 targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0);
2162 TRAMPOLINE_TEMPLATE (asm_out_file);
2163
2164 /* Record the rtl to refer to it. */
2165 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
2166 name = ggc_strdup (label);
2167 symbol = gen_rtx_SYMBOL_REF (Pmode, name);
2168 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2169
2170 initial_trampoline = gen_rtx_MEM (BLKmode, symbol);
2171 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
2172
2173 return initial_trampoline;
2174 }
2175 #endif
2176
2177 /* A and B are either alignments or offsets. Return the minimum alignment
2178 that may be assumed after adding the two together. */
2179
2180 static inline unsigned
min_align(unsigned int a,unsigned int b)2181 min_align (unsigned int a, unsigned int b)
2182 {
2183 return (a | b) & -(a | b);
2184 }
2185
2186 /* Return the assembler directive for creating a given kind of integer
2187 object. SIZE is the number of bytes in the object and ALIGNED_P
2188 indicates whether it is known to be aligned. Return NULL if the
2189 assembly dialect has no such directive.
2190
2191 The returned string should be printed at the start of a new line and
2192 be followed immediately by the object's initial value. */
2193
2194 const char *
integer_asm_op(int size,int aligned_p)2195 integer_asm_op (int size, int aligned_p)
2196 {
2197 struct asm_int_op *ops;
2198
2199 if (aligned_p)
2200 ops = &targetm.asm_out.aligned_op;
2201 else
2202 ops = &targetm.asm_out.unaligned_op;
2203
2204 switch (size)
2205 {
2206 case 1:
2207 return targetm.asm_out.byte_op;
2208 case 2:
2209 return ops->hi;
2210 case 4:
2211 return ops->si;
2212 case 8:
2213 return ops->di;
2214 case 16:
2215 return ops->ti;
2216 default:
2217 return NULL;
2218 }
2219 }
2220
2221 /* Use directive OP to assemble an integer object X. Print OP at the
2222 start of the line, followed immediately by the value of X. */
2223
2224 void
assemble_integer_with_op(const char * op,rtx x)2225 assemble_integer_with_op (const char *op, rtx x)
2226 {
2227 fputs (op, asm_out_file);
2228 output_addr_const (asm_out_file, x);
2229 fputc ('\n', asm_out_file);
2230 }
2231
2232 /* The default implementation of the asm_out.integer target hook. */
2233
2234 bool
default_assemble_integer(rtx x ATTRIBUTE_UNUSED,unsigned int size ATTRIBUTE_UNUSED,int aligned_p ATTRIBUTE_UNUSED)2235 default_assemble_integer (rtx x ATTRIBUTE_UNUSED,
2236 unsigned int size ATTRIBUTE_UNUSED,
2237 int aligned_p ATTRIBUTE_UNUSED)
2238 {
2239 const char *op = integer_asm_op (size, aligned_p);
2240 /* Avoid GAS bugs for large values. Specifically negative values whose
2241 absolute value fits in a bfd_vma, but not in a bfd_signed_vma. */
2242 if (size > UNITS_PER_WORD && size > POINTER_SIZE / BITS_PER_UNIT)
2243 return false;
2244 return op && (assemble_integer_with_op (op, x), true);
2245 }
2246
2247 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
2248 the alignment of the integer in bits. Return 1 if we were able to output
2249 the constant, otherwise 0. We must be able to output the constant,
2250 if FORCE is nonzero. */
2251
2252 bool
assemble_integer(rtx x,unsigned int size,unsigned int align,int force)2253 assemble_integer (rtx x, unsigned int size, unsigned int align, int force)
2254 {
2255 int aligned_p;
2256
2257 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT));
2258
2259 /* See if the target hook can handle this kind of object. */
2260 if (targetm.asm_out.integer (x, size, aligned_p))
2261 return true;
2262
2263 /* If the object is a multi-byte one, try splitting it up. Split
2264 it into words it if is multi-word, otherwise split it into bytes. */
2265 if (size > 1)
2266 {
2267 enum machine_mode omode, imode;
2268 unsigned int subalign;
2269 unsigned int subsize, i;
2270
2271 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1;
2272 subalign = MIN (align, subsize * BITS_PER_UNIT);
2273 omode = mode_for_size (subsize * BITS_PER_UNIT, MODE_INT, 0);
2274 imode = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2275
2276 for (i = 0; i < size; i += subsize)
2277 {
2278 rtx partial = simplify_subreg (omode, x, imode, i);
2279 if (!partial || !assemble_integer (partial, subsize, subalign, 0))
2280 break;
2281 }
2282 if (i == size)
2283 return true;
2284
2285 /* If we've printed some of it, but not all of it, there's no going
2286 back now. */
2287 gcc_assert (!i);
2288 }
2289
2290 gcc_assert (!force);
2291
2292 return false;
2293 }
2294
2295 void
assemble_real(REAL_VALUE_TYPE d,enum machine_mode mode,unsigned int align)2296 assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align)
2297 {
2298 long data[4] = {0, 0, 0, 0};
2299 int i;
2300 int bitsize, nelts, nunits, units_per;
2301
2302 /* This is hairy. We have a quantity of known size. real_to_target
2303 will put it into an array of *host* longs, 32 bits per element
2304 (even if long is more than 32 bits). We need to determine the
2305 number of array elements that are occupied (nelts) and the number
2306 of *target* min-addressable units that will be occupied in the
2307 object file (nunits). We cannot assume that 32 divides the
2308 mode's bitsize (size * BITS_PER_UNIT) evenly.
2309
2310 size * BITS_PER_UNIT is used here to make sure that padding bits
2311 (which might appear at either end of the value; real_to_target
2312 will include the padding bits in its output array) are included. */
2313
2314 nunits = GET_MODE_SIZE (mode);
2315 bitsize = nunits * BITS_PER_UNIT;
2316 nelts = CEIL (bitsize, 32);
2317 units_per = 32 / BITS_PER_UNIT;
2318
2319 real_to_target (data, &d, mode);
2320
2321 /* Put out the first word with the specified alignment. */
2322 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1);
2323 nunits -= units_per;
2324
2325 /* Subsequent words need only 32-bit alignment. */
2326 align = min_align (align, 32);
2327
2328 for (i = 1; i < nelts; i++)
2329 {
2330 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1);
2331 nunits -= units_per;
2332 }
2333 }
2334
2335 /* Given an expression EXP with a constant value,
2336 reduce it to the sum of an assembler symbol and an integer.
2337 Store them both in the structure *VALUE.
2338 EXP must be reducible. */
2339
2340 struct addr_const GTY(())
2341 {
2342 rtx base;
2343 HOST_WIDE_INT offset;
2344 };
2345
2346 static void
decode_addr_const(tree exp,struct addr_const * value)2347 decode_addr_const (tree exp, struct addr_const *value)
2348 {
2349 tree target = TREE_OPERAND (exp, 0);
2350 int offset = 0;
2351 rtx x;
2352
2353 while (1)
2354 {
2355 if (TREE_CODE (target) == COMPONENT_REF
2356 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0))
2357
2358 {
2359 offset += int_byte_position (TREE_OPERAND (target, 1));
2360 target = TREE_OPERAND (target, 0);
2361 }
2362 else if (TREE_CODE (target) == ARRAY_REF
2363 || TREE_CODE (target) == ARRAY_RANGE_REF)
2364 {
2365 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1)
2366 * tree_low_cst (TREE_OPERAND (target, 1), 0));
2367 target = TREE_OPERAND (target, 0);
2368 }
2369 else
2370 break;
2371 }
2372
2373 switch (TREE_CODE (target))
2374 {
2375 case VAR_DECL:
2376 case FUNCTION_DECL:
2377 x = DECL_RTL (target);
2378 break;
2379
2380 case LABEL_DECL:
2381 x = gen_rtx_MEM (FUNCTION_MODE,
2382 gen_rtx_LABEL_REF (Pmode, force_label_rtx (target)));
2383 break;
2384
2385 case REAL_CST:
2386 case STRING_CST:
2387 case COMPLEX_CST:
2388 case CONSTRUCTOR:
2389 case INTEGER_CST:
2390 x = output_constant_def (target, 1);
2391 break;
2392
2393 default:
2394 gcc_unreachable ();
2395 }
2396
2397 gcc_assert (MEM_P (x));
2398 x = XEXP (x, 0);
2399
2400 value->base = x;
2401 value->offset = offset;
2402 }
2403
2404 /* Uniquize all constants that appear in memory.
2405 Each constant in memory thus far output is recorded
2406 in `const_desc_table'. */
2407
2408 struct constant_descriptor_tree GTY(())
2409 {
2410 /* A MEM for the constant. */
2411 rtx rtl;
2412
2413 /* The value of the constant. */
2414 tree value;
2415
2416 /* Hash of value. Computing the hash from value each time
2417 hashfn is called can't work properly, as that means recursive
2418 use of the hash table during hash table expansion. */
2419 hashval_t hash;
2420 };
2421
2422 static GTY((param_is (struct constant_descriptor_tree)))
2423 htab_t const_desc_htab;
2424
2425 static struct constant_descriptor_tree * build_constant_desc (tree);
2426 static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int);
2427
2428 /* Compute a hash code for a constant expression. */
2429
2430 static hashval_t
const_desc_hash(const void * ptr)2431 const_desc_hash (const void *ptr)
2432 {
2433 return ((struct constant_descriptor_tree *)ptr)->hash;
2434 }
2435
2436 static hashval_t
const_hash_1(const tree exp)2437 const_hash_1 (const tree exp)
2438 {
2439 const char *p;
2440 hashval_t hi;
2441 int len, i;
2442 enum tree_code code = TREE_CODE (exp);
2443
2444 /* Either set P and LEN to the address and len of something to hash and
2445 exit the switch or return a value. */
2446
2447 switch (code)
2448 {
2449 case INTEGER_CST:
2450 p = (char *) &TREE_INT_CST (exp);
2451 len = sizeof TREE_INT_CST (exp);
2452 break;
2453
2454 case REAL_CST:
2455 return real_hash (TREE_REAL_CST_PTR (exp));
2456
2457 case STRING_CST:
2458 p = TREE_STRING_POINTER (exp);
2459 len = TREE_STRING_LENGTH (exp);
2460 break;
2461
2462 case COMPLEX_CST:
2463 return (const_hash_1 (TREE_REALPART (exp)) * 5
2464 + const_hash_1 (TREE_IMAGPART (exp)));
2465
2466 case CONSTRUCTOR:
2467 {
2468 unsigned HOST_WIDE_INT idx;
2469 tree value;
2470
2471 hi = 5 + int_size_in_bytes (TREE_TYPE (exp));
2472
2473 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, value)
2474 if (value)
2475 hi = hi * 603 + const_hash_1 (value);
2476
2477 return hi;
2478 }
2479
2480 case ADDR_EXPR:
2481 case FDESC_EXPR:
2482 {
2483 struct addr_const value;
2484
2485 decode_addr_const (exp, &value);
2486 switch (GET_CODE (value.base))
2487 {
2488 case SYMBOL_REF:
2489 /* Don't hash the address of the SYMBOL_REF;
2490 only use the offset and the symbol name. */
2491 hi = value.offset;
2492 p = XSTR (value.base, 0);
2493 for (i = 0; p[i] != 0; i++)
2494 hi = ((hi * 613) + (unsigned) (p[i]));
2495 break;
2496
2497 case LABEL_REF:
2498 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2499 break;
2500
2501 default:
2502 gcc_unreachable ();
2503 }
2504 }
2505 return hi;
2506
2507 case PLUS_EXPR:
2508 case MINUS_EXPR:
2509 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9
2510 + const_hash_1 (TREE_OPERAND (exp, 1)));
2511
2512 case NOP_EXPR:
2513 case CONVERT_EXPR:
2514 case NON_LVALUE_EXPR:
2515 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2;
2516
2517 default:
2518 /* A language specific constant. Just hash the code. */
2519 return code;
2520 }
2521
2522 /* Compute hashing function. */
2523 hi = len;
2524 for (i = 0; i < len; i++)
2525 hi = ((hi * 613) + (unsigned) (p[i]));
2526
2527 return hi;
2528 }
2529
2530 /* Wrapper of compare_constant, for the htab interface. */
2531 static int
const_desc_eq(const void * p1,const void * p2)2532 const_desc_eq (const void *p1, const void *p2)
2533 {
2534 const struct constant_descriptor_tree *c1 = p1;
2535 const struct constant_descriptor_tree *c2 = p2;
2536 if (c1->hash != c2->hash)
2537 return 0;
2538 return compare_constant (c1->value, c2->value);
2539 }
2540
2541 /* Compare t1 and t2, and return 1 only if they are known to result in
2542 the same bit pattern on output. */
2543
2544 static int
compare_constant(const tree t1,const tree t2)2545 compare_constant (const tree t1, const tree t2)
2546 {
2547 enum tree_code typecode;
2548
2549 if (t1 == NULL_TREE)
2550 return t2 == NULL_TREE;
2551 if (t2 == NULL_TREE)
2552 return 0;
2553
2554 if (TREE_CODE (t1) != TREE_CODE (t2))
2555 return 0;
2556
2557 switch (TREE_CODE (t1))
2558 {
2559 case INTEGER_CST:
2560 /* Integer constants are the same only if the same width of type. */
2561 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2562 return 0;
2563 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2564 return 0;
2565 return tree_int_cst_equal (t1, t2);
2566
2567 case REAL_CST:
2568 /* Real constants are the same only if the same width of type. */
2569 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2570 return 0;
2571
2572 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2573
2574 case STRING_CST:
2575 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2576 return 0;
2577
2578 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2579 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2580 TREE_STRING_LENGTH (t1)));
2581
2582 case COMPLEX_CST:
2583 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2))
2584 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2)));
2585
2586 case CONSTRUCTOR:
2587 {
2588 VEC(constructor_elt, gc) *v1, *v2;
2589 unsigned HOST_WIDE_INT idx;
2590
2591 typecode = TREE_CODE (TREE_TYPE (t1));
2592 if (typecode != TREE_CODE (TREE_TYPE (t2)))
2593 return 0;
2594
2595 if (typecode == ARRAY_TYPE)
2596 {
2597 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1));
2598 /* For arrays, check that the sizes all match. */
2599 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))
2600 || size_1 == -1
2601 || size_1 != int_size_in_bytes (TREE_TYPE (t2)))
2602 return 0;
2603 }
2604 else
2605 {
2606 /* For record and union constructors, require exact type
2607 equality. */
2608 if (TREE_TYPE (t1) != TREE_TYPE (t2))
2609 return 0;
2610 }
2611
2612 v1 = CONSTRUCTOR_ELTS (t1);
2613 v2 = CONSTRUCTOR_ELTS (t2);
2614 if (VEC_length (constructor_elt, v1)
2615 != VEC_length (constructor_elt, v2))
2616 return 0;
2617
2618 for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx)
2619 {
2620 constructor_elt *c1 = VEC_index (constructor_elt, v1, idx);
2621 constructor_elt *c2 = VEC_index (constructor_elt, v2, idx);
2622
2623 /* Check that each value is the same... */
2624 if (!compare_constant (c1->value, c2->value))
2625 return 0;
2626 /* ... and that they apply to the same fields! */
2627 if (typecode == ARRAY_TYPE)
2628 {
2629 if (!compare_constant (c1->index, c2->index))
2630 return 0;
2631 }
2632 else
2633 {
2634 if (c1->index != c2->index)
2635 return 0;
2636 }
2637 }
2638
2639 return 1;
2640 }
2641
2642 case ADDR_EXPR:
2643 case FDESC_EXPR:
2644 {
2645 struct addr_const value1, value2;
2646
2647 decode_addr_const (t1, &value1);
2648 decode_addr_const (t2, &value2);
2649 return (value1.offset == value2.offset
2650 && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0);
2651 }
2652
2653 case PLUS_EXPR:
2654 case MINUS_EXPR:
2655 case RANGE_EXPR:
2656 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
2657 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
2658
2659 case NOP_EXPR:
2660 case CONVERT_EXPR:
2661 case NON_LVALUE_EXPR:
2662 case VIEW_CONVERT_EXPR:
2663 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2664
2665 default:
2666 {
2667 tree nt1, nt2;
2668 nt1 = lang_hooks.expand_constant (t1);
2669 nt2 = lang_hooks.expand_constant (t2);
2670 if (nt1 != t1 || nt2 != t2)
2671 return compare_constant (nt1, nt2);
2672 else
2673 return 0;
2674 }
2675 }
2676
2677 gcc_unreachable ();
2678 }
2679
2680 /* Make a copy of the whole tree structure for a constant. This
2681 handles the same types of nodes that compare_constant handles. */
2682
2683 static tree
copy_constant(tree exp)2684 copy_constant (tree exp)
2685 {
2686 switch (TREE_CODE (exp))
2687 {
2688 case ADDR_EXPR:
2689 /* For ADDR_EXPR, we do not want to copy the decl whose address
2690 is requested. We do want to copy constants though. */
2691 if (CONSTANT_CLASS_P (TREE_OPERAND (exp, 0)))
2692 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2693 copy_constant (TREE_OPERAND (exp, 0)));
2694 else
2695 return copy_node (exp);
2696
2697 case INTEGER_CST:
2698 case REAL_CST:
2699 case STRING_CST:
2700 return copy_node (exp);
2701
2702 case COMPLEX_CST:
2703 return build_complex (TREE_TYPE (exp),
2704 copy_constant (TREE_REALPART (exp)),
2705 copy_constant (TREE_IMAGPART (exp)));
2706
2707 case PLUS_EXPR:
2708 case MINUS_EXPR:
2709 return build2 (TREE_CODE (exp), TREE_TYPE (exp),
2710 copy_constant (TREE_OPERAND (exp, 0)),
2711 copy_constant (TREE_OPERAND (exp, 1)));
2712
2713 case NOP_EXPR:
2714 case CONVERT_EXPR:
2715 case NON_LVALUE_EXPR:
2716 case VIEW_CONVERT_EXPR:
2717 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2718 copy_constant (TREE_OPERAND (exp, 0)));
2719
2720 case CONSTRUCTOR:
2721 {
2722 tree copy = copy_node (exp);
2723 VEC(constructor_elt, gc) *v;
2724 unsigned HOST_WIDE_INT idx;
2725 tree purpose, value;
2726
2727 v = VEC_alloc(constructor_elt, gc, VEC_length(constructor_elt,
2728 CONSTRUCTOR_ELTS (exp)));
2729 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (exp), idx, purpose, value)
2730 {
2731 constructor_elt *ce = VEC_quick_push (constructor_elt, v, NULL);
2732 ce->index = purpose;
2733 ce->value = copy_constant (value);
2734 }
2735 CONSTRUCTOR_ELTS (copy) = v;
2736 return copy;
2737 }
2738
2739 default:
2740 {
2741 tree t = lang_hooks.expand_constant (exp);
2742
2743 gcc_assert (t != exp);
2744 return copy_constant (t);
2745 }
2746 }
2747 }
2748
2749 /* Return the alignment of constant EXP in bits. */
2750
2751 static unsigned int
get_constant_alignment(tree exp)2752 get_constant_alignment (tree exp)
2753 {
2754 unsigned int align;
2755
2756 align = TYPE_ALIGN (TREE_TYPE (exp));
2757 #ifdef CONSTANT_ALIGNMENT
2758 align = CONSTANT_ALIGNMENT (exp, align);
2759 #endif
2760 return align;
2761 }
2762
2763 /* Return the section into which constant EXP should be placed. */
2764
2765 static section *
get_constant_section(tree exp)2766 get_constant_section (tree exp)
2767 {
2768 if (IN_NAMED_SECTION (exp))
2769 return get_named_section (exp, NULL, compute_reloc_for_constant (exp));
2770 else
2771 return targetm.asm_out.select_section (exp,
2772 compute_reloc_for_constant (exp),
2773 get_constant_alignment (exp));
2774 }
2775
2776 /* Return the size of constant EXP in bytes. */
2777
2778 static HOST_WIDE_INT
get_constant_size(tree exp)2779 get_constant_size (tree exp)
2780 {
2781 HOST_WIDE_INT size;
2782
2783 size = int_size_in_bytes (TREE_TYPE (exp));
2784 if (TREE_CODE (exp) == STRING_CST)
2785 size = MAX (TREE_STRING_LENGTH (exp), size);
2786 return size;
2787 }
2788
2789 /* Subroutine of output_constant_def:
2790 No constant equal to EXP is known to have been output.
2791 Make a constant descriptor to enter EXP in the hash table.
2792 Assign the label number and construct RTL to refer to the
2793 constant's location in memory.
2794 Caller is responsible for updating the hash table. */
2795
2796 static struct constant_descriptor_tree *
build_constant_desc(tree exp)2797 build_constant_desc (tree exp)
2798 {
2799 rtx symbol;
2800 rtx rtl;
2801 char label[256];
2802 int labelno;
2803 struct constant_descriptor_tree *desc;
2804
2805 desc = ggc_alloc (sizeof (*desc));
2806 desc->value = copy_constant (exp);
2807
2808 /* Propagate marked-ness to copied constant. */
2809 if (flag_mudflap && mf_marked_p (exp))
2810 mf_mark (desc->value);
2811
2812 /* Create a string containing the label name, in LABEL. */
2813 labelno = const_labelno++;
2814 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno);
2815
2816 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
2817 if (use_object_blocks_p ())
2818 {
2819 section *sect = get_constant_section (exp);
2820 symbol = create_block_symbol (ggc_strdup (label),
2821 get_block_for_section (sect), -1);
2822 }
2823 else
2824 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
2825 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
2826 SET_SYMBOL_REF_DECL (symbol, desc->value);
2827 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
2828
2829 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol);
2830 set_mem_attributes (rtl, exp, 1);
2831 set_mem_alias_set (rtl, 0);
2832 set_mem_alias_set (rtl, const_alias_set);
2833
2834 /* Set flags or add text to the name to record information, such as
2835 that it is a local symbol. If the name is changed, the macro
2836 ASM_OUTPUT_LABELREF will have to know how to strip this
2837 information. This call might invalidate our local variable
2838 SYMBOL; we can't use it afterward. */
2839
2840 targetm.encode_section_info (exp, rtl, true);
2841
2842 desc->rtl = rtl;
2843
2844 return desc;
2845 }
2846
2847 /* Return an rtx representing a reference to constant data in memory
2848 for the constant expression EXP.
2849
2850 If assembler code for such a constant has already been output,
2851 return an rtx to refer to it.
2852 Otherwise, output such a constant in memory
2853 and generate an rtx for it.
2854
2855 If DEFER is nonzero, this constant can be deferred and output only
2856 if referenced in the function after all optimizations.
2857
2858 `const_desc_table' records which constants already have label strings. */
2859
2860 rtx
output_constant_def(tree exp,int defer)2861 output_constant_def (tree exp, int defer)
2862 {
2863 struct constant_descriptor_tree *desc;
2864 struct constant_descriptor_tree key;
2865 void **loc;
2866
2867 /* Look up EXP in the table of constant descriptors. If we didn't find
2868 it, create a new one. */
2869 key.value = exp;
2870 key.hash = const_hash_1 (exp);
2871 loc = htab_find_slot_with_hash (const_desc_htab, &key, key.hash, INSERT);
2872
2873 desc = *loc;
2874 if (desc == 0)
2875 {
2876 desc = build_constant_desc (exp);
2877 desc->hash = key.hash;
2878 *loc = desc;
2879 }
2880
2881 maybe_output_constant_def_contents (desc, defer);
2882 return desc->rtl;
2883 }
2884
2885 /* Subroutine of output_constant_def: Decide whether or not we need to
2886 output the constant DESC now, and if so, do it. */
2887 static void
maybe_output_constant_def_contents(struct constant_descriptor_tree * desc,int defer)2888 maybe_output_constant_def_contents (struct constant_descriptor_tree *desc,
2889 int defer)
2890 {
2891 rtx symbol = XEXP (desc->rtl, 0);
2892 tree exp = desc->value;
2893
2894 if (flag_syntax_only)
2895 return;
2896
2897 if (TREE_ASM_WRITTEN (exp))
2898 /* Already output; don't do it again. */
2899 return;
2900
2901 /* We can always defer constants as long as the context allows
2902 doing so. */
2903 if (defer)
2904 {
2905 /* Increment n_deferred_constants if it exists. It needs to be at
2906 least as large as the number of constants actually referred to
2907 by the function. If it's too small we'll stop looking too early
2908 and fail to emit constants; if it's too large we'll only look
2909 through the entire function when we could have stopped earlier. */
2910 if (cfun)
2911 n_deferred_constants++;
2912 return;
2913 }
2914
2915 output_constant_def_contents (symbol);
2916 }
2917
2918 /* Subroutine of output_constant_def_contents. Output the definition
2919 of constant EXP, which is pointed to by label LABEL. ALIGN is the
2920 constant's alignment in bits. */
2921
2922 static void
assemble_constant_contents(tree exp,const char * label,unsigned int align)2923 assemble_constant_contents (tree exp, const char *label, unsigned int align)
2924 {
2925 HOST_WIDE_INT size;
2926
2927 size = get_constant_size (exp);
2928
2929 /* Do any machine/system dependent processing of the constant. */
2930 #ifdef ASM_DECLARE_CONSTANT_NAME
2931 ASM_DECLARE_CONSTANT_NAME (asm_out_file, label, exp, size);
2932 #else
2933 /* Standard thing is just output label for the constant. */
2934 ASM_OUTPUT_LABEL (asm_out_file, label);
2935 #endif /* ASM_DECLARE_CONSTANT_NAME */
2936
2937 /* Output the value of EXP. */
2938 output_constant (exp, size, align);
2939 }
2940
2941 /* We must output the constant data referred to by SYMBOL; do so. */
2942
2943 static void
output_constant_def_contents(rtx symbol)2944 output_constant_def_contents (rtx symbol)
2945 {
2946 tree exp = SYMBOL_REF_DECL (symbol);
2947 unsigned int align;
2948
2949 /* Make sure any other constants whose addresses appear in EXP
2950 are assigned label numbers. */
2951 output_addressed_constants (exp);
2952
2953 /* We are no longer deferring this constant. */
2954 TREE_ASM_WRITTEN (exp) = 1;
2955
2956 /* If the constant is part of an object block, make sure that the
2957 decl has been positioned within its block, but do not write out
2958 its definition yet. output_object_blocks will do that later. */
2959 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
2960 place_block_symbol (symbol);
2961 else
2962 {
2963 switch_to_section (get_constant_section (exp));
2964 align = get_constant_alignment (exp);
2965 if (align > BITS_PER_UNIT)
2966 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
2967 assemble_constant_contents (exp, XSTR (symbol, 0), align);
2968 }
2969 if (flag_mudflap)
2970 mudflap_enqueue_constant (exp);
2971 }
2972
2973 /* Look up EXP in the table of constant descriptors. Return the rtl
2974 if it has been emitted, else null. */
2975
2976 rtx
lookup_constant_def(tree exp)2977 lookup_constant_def (tree exp)
2978 {
2979 struct constant_descriptor_tree *desc;
2980 struct constant_descriptor_tree key;
2981
2982 key.value = exp;
2983 key.hash = const_hash_1 (exp);
2984 desc = htab_find_with_hash (const_desc_htab, &key, key.hash);
2985
2986 return (desc ? desc->rtl : NULL_RTX);
2987 }
2988
2989 /* Used in the hash tables to avoid outputting the same constant
2990 twice. Unlike 'struct constant_descriptor_tree', RTX constants
2991 are output once per function, not once per file. */
2992 /* ??? Only a few targets need per-function constant pools. Most
2993 can use one per-file pool. Should add a targetm bit to tell the
2994 difference. */
2995
2996 struct rtx_constant_pool GTY(())
2997 {
2998 /* Pointers to first and last constant in pool, as ordered by offset. */
2999 struct constant_descriptor_rtx *first;
3000 struct constant_descriptor_rtx *last;
3001
3002 /* Hash facility for making memory-constants from constant rtl-expressions.
3003 It is used on RISC machines where immediate integer arguments and
3004 constant addresses are restricted so that such constants must be stored
3005 in memory. */
3006 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab;
3007
3008 /* Current offset in constant pool (does not include any
3009 machine-specific header). */
3010 HOST_WIDE_INT offset;
3011 };
3012
3013 struct constant_descriptor_rtx GTY((chain_next ("%h.next")))
3014 {
3015 struct constant_descriptor_rtx *next;
3016 rtx mem;
3017 rtx sym;
3018 rtx constant;
3019 HOST_WIDE_INT offset;
3020 hashval_t hash;
3021 enum machine_mode mode;
3022 unsigned int align;
3023 int labelno;
3024 int mark;
3025 };
3026
3027 /* Hash and compare functions for const_rtx_htab. */
3028
3029 static hashval_t
const_desc_rtx_hash(const void * ptr)3030 const_desc_rtx_hash (const void *ptr)
3031 {
3032 const struct constant_descriptor_rtx *desc = ptr;
3033 return desc->hash;
3034 }
3035
3036 static int
const_desc_rtx_eq(const void * a,const void * b)3037 const_desc_rtx_eq (const void *a, const void *b)
3038 {
3039 const struct constant_descriptor_rtx *x = a;
3040 const struct constant_descriptor_rtx *y = b;
3041
3042 if (x->mode != y->mode)
3043 return 0;
3044 return rtx_equal_p (x->constant, y->constant);
3045 }
3046
3047 /* This is the worker function for const_rtx_hash, called via for_each_rtx. */
3048
3049 static int
const_rtx_hash_1(rtx * xp,void * data)3050 const_rtx_hash_1 (rtx *xp, void *data)
3051 {
3052 unsigned HOST_WIDE_INT hwi;
3053 enum machine_mode mode;
3054 enum rtx_code code;
3055 hashval_t h, *hp;
3056 rtx x;
3057
3058 x = *xp;
3059 code = GET_CODE (x);
3060 mode = GET_MODE (x);
3061 h = (hashval_t) code * 1048573 + mode;
3062
3063 switch (code)
3064 {
3065 case CONST_INT:
3066 hwi = INTVAL (x);
3067 fold_hwi:
3068 {
3069 const int shift = sizeof (hashval_t) * CHAR_BIT;
3070 const int n = sizeof (HOST_WIDE_INT) / sizeof (hashval_t);
3071 int i;
3072
3073 h ^= (hashval_t) hwi;
3074 for (i = 1; i < n; ++i)
3075 {
3076 hwi >>= shift;
3077 h ^= (hashval_t) hwi;
3078 }
3079 }
3080 break;
3081
3082 case CONST_DOUBLE:
3083 if (mode == VOIDmode)
3084 {
3085 hwi = CONST_DOUBLE_LOW (x) ^ CONST_DOUBLE_HIGH (x);
3086 goto fold_hwi;
3087 }
3088 else
3089 h ^= real_hash (CONST_DOUBLE_REAL_VALUE (x));
3090 break;
3091
3092 case CONST_VECTOR:
3093 {
3094 int i;
3095 for (i = XVECLEN (x, 0); i-- > 0; )
3096 h = h * 251 + const_rtx_hash_1 (&XVECEXP (x, 0, i), data);
3097 }
3098 break;
3099
3100 case SYMBOL_REF:
3101 h ^= htab_hash_string (XSTR (x, 0));
3102 break;
3103
3104 case LABEL_REF:
3105 h = h * 251 + CODE_LABEL_NUMBER (XEXP (x, 0));
3106 break;
3107
3108 case UNSPEC:
3109 case UNSPEC_VOLATILE:
3110 h = h * 251 + XINT (x, 1);
3111 break;
3112
3113 default:
3114 break;
3115 }
3116
3117 hp = data;
3118 *hp = *hp * 509 + h;
3119 return 0;
3120 }
3121
3122 /* Compute a hash value for X, which should be a constant. */
3123
3124 static hashval_t
const_rtx_hash(rtx x)3125 const_rtx_hash (rtx x)
3126 {
3127 hashval_t h = 0;
3128 for_each_rtx (&x, const_rtx_hash_1, &h);
3129 return h;
3130 }
3131
3132
3133 /* Create and return a new rtx constant pool. */
3134
3135 static struct rtx_constant_pool *
create_constant_pool(void)3136 create_constant_pool (void)
3137 {
3138 struct rtx_constant_pool *pool;
3139
3140 pool = ggc_alloc (sizeof (struct rtx_constant_pool));
3141 pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash,
3142 const_desc_rtx_eq, NULL);
3143 pool->first = NULL;
3144 pool->last = NULL;
3145 pool->offset = 0;
3146 return pool;
3147 }
3148
3149 /* Initialize constant pool hashing for a new function. */
3150
3151 void
init_varasm_status(struct function * f)3152 init_varasm_status (struct function *f)
3153 {
3154 struct varasm_status *p;
3155
3156 p = ggc_alloc (sizeof (struct varasm_status));
3157 f->varasm = p;
3158
3159 p->pool = create_constant_pool ();
3160 p->deferred_constants = 0;
3161 }
3162
3163 /* Given a MINUS expression, simplify it if both sides
3164 include the same symbol. */
3165
3166 rtx
simplify_subtraction(rtx x)3167 simplify_subtraction (rtx x)
3168 {
3169 rtx r = simplify_rtx (x);
3170 return r ? r : x;
3171 }
3172
3173 /* Given a constant rtx X, make (or find) a memory constant for its value
3174 and return a MEM rtx to refer to it in memory. */
3175
3176 rtx
force_const_mem(enum machine_mode mode,rtx x)3177 force_const_mem (enum machine_mode mode, rtx x)
3178 {
3179 struct constant_descriptor_rtx *desc, tmp;
3180 struct rtx_constant_pool *pool;
3181 char label[256];
3182 rtx def, symbol;
3183 hashval_t hash;
3184 unsigned int align;
3185 void **slot;
3186
3187 /* If we're not allowed to drop X into the constant pool, don't. */
3188 if (targetm.cannot_force_const_mem (x))
3189 return NULL_RTX;
3190
3191 /* Record that this function has used a constant pool entry. */
3192 current_function_uses_const_pool = 1;
3193
3194 /* Decide which pool to use. */
3195 pool = (targetm.use_blocks_for_constant_p (mode, x)
3196 ? shared_constant_pool
3197 : cfun->varasm->pool);
3198
3199 /* Lookup the value in the hashtable. */
3200 tmp.constant = x;
3201 tmp.mode = mode;
3202 hash = const_rtx_hash (x);
3203 slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT);
3204 desc = *slot;
3205
3206 /* If the constant was already present, return its memory. */
3207 if (desc)
3208 return copy_rtx (desc->mem);
3209
3210 /* Otherwise, create a new descriptor. */
3211 desc = ggc_alloc (sizeof (*desc));
3212 *slot = desc;
3213
3214 /* Align the location counter as required by EXP's data type. */
3215 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode);
3216 #ifdef CONSTANT_ALIGNMENT
3217 {
3218 tree type = lang_hooks.types.type_for_mode (mode, 0);
3219 if (type != NULL_TREE)
3220 align = CONSTANT_ALIGNMENT (make_tree (type, x), align);
3221 }
3222 #endif
3223
3224 pool->offset += (align / BITS_PER_UNIT) - 1;
3225 pool->offset &= ~ ((align / BITS_PER_UNIT) - 1);
3226
3227 desc->next = NULL;
3228 desc->constant = tmp.constant;
3229 desc->offset = pool->offset;
3230 desc->hash = hash;
3231 desc->mode = mode;
3232 desc->align = align;
3233 desc->labelno = const_labelno;
3234 desc->mark = 0;
3235
3236 pool->offset += GET_MODE_SIZE (mode);
3237 if (pool->last)
3238 pool->last->next = desc;
3239 else
3240 pool->first = pool->last = desc;
3241 pool->last = desc;
3242
3243 /* Create a string containing the label name, in LABEL. */
3244 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
3245 ++const_labelno;
3246
3247 /* Construct the SYMBOL_REF. Make sure to mark it as belonging to
3248 the constants pool. */
3249 if (use_object_blocks_p () && targetm.use_blocks_for_constant_p (mode, x))
3250 {
3251 section *sect = targetm.asm_out.select_rtx_section (mode, x, align);
3252 symbol = create_block_symbol (ggc_strdup (label),
3253 get_block_for_section (sect), -1);
3254 }
3255 else
3256 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3257 desc->sym = symbol;
3258 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3259 CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3260 SET_SYMBOL_REF_CONSTANT (symbol, desc);
3261
3262 /* Construct the MEM. */
3263 desc->mem = def = gen_const_mem (mode, symbol);
3264 set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1);
3265 set_mem_align (def, align);
3266
3267 /* If we're dropping a label to the constant pool, make sure we
3268 don't delete it. */
3269 if (GET_CODE (x) == LABEL_REF)
3270 LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
3271
3272 return copy_rtx (def);
3273 }
3274
3275 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
3276
3277 rtx
get_pool_constant(rtx addr)3278 get_pool_constant (rtx addr)
3279 {
3280 return SYMBOL_REF_CONSTANT (addr)->constant;
3281 }
3282
3283 /* Given a constant pool SYMBOL_REF, return the corresponding constant
3284 and whether it has been output or not. */
3285
3286 rtx
get_pool_constant_mark(rtx addr,bool * pmarked)3287 get_pool_constant_mark (rtx addr, bool *pmarked)
3288 {
3289 struct constant_descriptor_rtx *desc;
3290
3291 desc = SYMBOL_REF_CONSTANT (addr);
3292 *pmarked = (desc->mark != 0);
3293 return desc->constant;
3294 }
3295
3296 /* Similar, return the mode. */
3297
3298 enum machine_mode
get_pool_mode(rtx addr)3299 get_pool_mode (rtx addr)
3300 {
3301 return SYMBOL_REF_CONSTANT (addr)->mode;
3302 }
3303
3304 /* Return the size of the constant pool. */
3305
3306 int
get_pool_size(void)3307 get_pool_size (void)
3308 {
3309 return cfun->varasm->pool->offset;
3310 }
3311
3312 /* Worker function for output_constant_pool_1. Emit assembly for X
3313 in MODE with known alignment ALIGN. */
3314
3315 static void
output_constant_pool_2(enum machine_mode mode,rtx x,unsigned int align)3316 output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align)
3317 {
3318 switch (GET_MODE_CLASS (mode))
3319 {
3320 case MODE_FLOAT:
3321 case MODE_DECIMAL_FLOAT:
3322 {
3323 REAL_VALUE_TYPE r;
3324
3325 gcc_assert (GET_CODE (x) == CONST_DOUBLE);
3326 REAL_VALUE_FROM_CONST_DOUBLE (r, x);
3327 assemble_real (r, mode, align);
3328 break;
3329 }
3330
3331 case MODE_INT:
3332 case MODE_PARTIAL_INT:
3333 assemble_integer (x, GET_MODE_SIZE (mode), align, 1);
3334 break;
3335
3336 case MODE_VECTOR_FLOAT:
3337 case MODE_VECTOR_INT:
3338 {
3339 int i, units;
3340 enum machine_mode submode = GET_MODE_INNER (mode);
3341 unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode));
3342
3343 gcc_assert (GET_CODE (x) == CONST_VECTOR);
3344 units = CONST_VECTOR_NUNITS (x);
3345
3346 for (i = 0; i < units; i++)
3347 {
3348 rtx elt = CONST_VECTOR_ELT (x, i);
3349 output_constant_pool_2 (submode, elt, i ? subalign : align);
3350 }
3351 }
3352 break;
3353
3354 default:
3355 gcc_unreachable ();
3356 }
3357 }
3358
3359 /* Worker function for output_constant_pool. Emit constant DESC,
3360 giving it ALIGN bits of alignment. */
3361
3362 static void
output_constant_pool_1(struct constant_descriptor_rtx * desc,unsigned int align)3363 output_constant_pool_1 (struct constant_descriptor_rtx *desc,
3364 unsigned int align)
3365 {
3366 rtx x, tmp;
3367
3368 x = desc->constant;
3369
3370 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3371 whose CODE_LABEL has been deleted. This can occur if a jump table
3372 is eliminated by optimization. If so, write a constant of zero
3373 instead. Note that this can also happen by turning the
3374 CODE_LABEL into a NOTE. */
3375 /* ??? This seems completely and utterly wrong. Certainly it's
3376 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper
3377 functioning even with INSN_DELETED_P and friends. */
3378
3379 tmp = x;
3380 switch (GET_CODE (x))
3381 {
3382 case CONST:
3383 if (GET_CODE (XEXP (x, 0)) != PLUS
3384 || GET_CODE (XEXP (XEXP (x, 0), 0)) != LABEL_REF)
3385 break;
3386 tmp = XEXP (XEXP (x, 0), 0);
3387 /* FALLTHRU */
3388
3389 case LABEL_REF:
3390 tmp = XEXP (x, 0);
3391 gcc_assert (!INSN_DELETED_P (tmp));
3392 gcc_assert (!NOTE_P (tmp)
3393 || NOTE_LINE_NUMBER (tmp) != NOTE_INSN_DELETED);
3394 break;
3395
3396 default:
3397 break;
3398 }
3399
3400 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3401 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode,
3402 align, desc->labelno, done);
3403 #endif
3404
3405 assemble_align (align);
3406
3407 /* Output the label. */
3408 targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno);
3409
3410 /* Output the data. */
3411 output_constant_pool_2 (desc->mode, x, align);
3412
3413 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS
3414 sections have proper size. */
3415 if (align > GET_MODE_BITSIZE (desc->mode)
3416 && in_section
3417 && (in_section->common.flags & SECTION_MERGE))
3418 assemble_align (align);
3419
3420 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3421 done:
3422 #endif
3423 return;
3424 }
3425
3426 /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
3427 to as used. Emit referenced deferred strings. This function can
3428 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */
3429
3430 static int
mark_constant(rtx * current_rtx,void * data ATTRIBUTE_UNUSED)3431 mark_constant (rtx *current_rtx, void *data ATTRIBUTE_UNUSED)
3432 {
3433 rtx x = *current_rtx;
3434
3435 if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF)
3436 return 0;
3437
3438 if (CONSTANT_POOL_ADDRESS_P (x))
3439 {
3440 struct constant_descriptor_rtx *desc = SYMBOL_REF_CONSTANT (x);
3441 if (desc->mark == 0)
3442 {
3443 desc->mark = 1;
3444 for_each_rtx (&desc->constant, mark_constant, NULL);
3445 }
3446 }
3447 else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
3448 {
3449 tree exp = SYMBOL_REF_DECL (x);
3450 if (!TREE_ASM_WRITTEN (exp))
3451 {
3452 n_deferred_constants--;
3453 output_constant_def_contents (x);
3454 }
3455 }
3456
3457 return -1;
3458 }
3459
3460 /* Look through appropriate parts of INSN, marking all entries in the
3461 constant pool which are actually being used. Entries that are only
3462 referenced by other constants are also marked as used. Emit
3463 deferred strings that are used. */
3464
3465 static void
mark_constants(rtx insn)3466 mark_constants (rtx insn)
3467 {
3468 if (!INSN_P (insn))
3469 return;
3470
3471 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3472 insns, not any notes that may be attached. We don't want to mark
3473 a constant just because it happens to appear in a REG_EQUIV note. */
3474 if (GET_CODE (PATTERN (insn)) == SEQUENCE)
3475 {
3476 rtx seq = PATTERN (insn);
3477 int i, n = XVECLEN (seq, 0);
3478 for (i = 0; i < n; ++i)
3479 {
3480 rtx subinsn = XVECEXP (seq, 0, i);
3481 if (INSN_P (subinsn))
3482 for_each_rtx (&PATTERN (subinsn), mark_constant, NULL);
3483 }
3484 }
3485 else
3486 for_each_rtx (&PATTERN (insn), mark_constant, NULL);
3487 }
3488
3489 /* Look through the instructions for this function, and mark all the
3490 entries in POOL which are actually being used. Emit deferred constants
3491 which have indeed been used. */
3492
3493 static void
mark_constant_pool(void)3494 mark_constant_pool (void)
3495 {
3496 rtx insn, link;
3497
3498 if (!current_function_uses_const_pool && n_deferred_constants == 0)
3499 return;
3500
3501 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3502 mark_constants (insn);
3503
3504 for (link = current_function_epilogue_delay_list;
3505 link;
3506 link = XEXP (link, 1))
3507 mark_constants (XEXP (link, 0));
3508 }
3509
3510 /* Write all the constants in POOL. */
3511
3512 static void
output_constant_pool_contents(struct rtx_constant_pool * pool)3513 output_constant_pool_contents (struct rtx_constant_pool *pool)
3514 {
3515 struct constant_descriptor_rtx *desc;
3516
3517 for (desc = pool->first; desc ; desc = desc->next)
3518 if (desc->mark)
3519 {
3520 /* If the constant is part of an object_block, make sure that
3521 the constant has been positioned within its block, but do not
3522 write out its definition yet. output_object_blocks will do
3523 that later. */
3524 if (SYMBOL_REF_HAS_BLOCK_INFO_P (desc->sym)
3525 && SYMBOL_REF_BLOCK (desc->sym))
3526 place_block_symbol (desc->sym);
3527 else
3528 {
3529 switch_to_section (targetm.asm_out.select_rtx_section
3530 (desc->mode, desc->constant, desc->align));
3531 output_constant_pool_1 (desc, desc->align);
3532 }
3533 }
3534 }
3535
3536 /* Mark all constants that are used in the current function, then write
3537 out the function's private constant pool. */
3538
3539 static void
output_constant_pool(const char * fnname ATTRIBUTE_UNUSED,tree fndecl ATTRIBUTE_UNUSED)3540 output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
3541 tree fndecl ATTRIBUTE_UNUSED)
3542 {
3543 struct rtx_constant_pool *pool = cfun->varasm->pool;
3544
3545 /* It is possible for gcc to call force_const_mem and then to later
3546 discard the instructions which refer to the constant. In such a
3547 case we do not need to output the constant. */
3548 mark_constant_pool ();
3549
3550 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3551 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset);
3552 #endif
3553
3554 output_constant_pool_contents (pool);
3555
3556 #ifdef ASM_OUTPUT_POOL_EPILOGUE
3557 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset);
3558 #endif
3559 }
3560
3561 /* Write the contents of the shared constant pool. */
3562
3563 void
output_shared_constant_pool(void)3564 output_shared_constant_pool (void)
3565 {
3566 output_constant_pool_contents (shared_constant_pool);
3567 }
3568
3569 /* Determine what kind of relocations EXP may need. */
3570
3571 int
compute_reloc_for_constant(tree exp)3572 compute_reloc_for_constant (tree exp)
3573 {
3574 int reloc = 0, reloc2;
3575 tree tem;
3576
3577 /* Give the front-end a chance to convert VALUE to something that
3578 looks more like a constant to the back-end. */
3579 exp = lang_hooks.expand_constant (exp);
3580
3581 switch (TREE_CODE (exp))
3582 {
3583 case ADDR_EXPR:
3584 case FDESC_EXPR:
3585 /* Go inside any operations that get_inner_reference can handle and see
3586 if what's inside is a constant: no need to do anything here for
3587 addresses of variables or functions. */
3588 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3589 tem = TREE_OPERAND (tem, 0))
3590 ;
3591
3592 if (TREE_PUBLIC (tem))
3593 reloc |= 2;
3594 else
3595 reloc |= 1;
3596 break;
3597
3598 case PLUS_EXPR:
3599 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3600 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3601 break;
3602
3603 case MINUS_EXPR:
3604 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3605 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3606 /* The difference of two local labels is computable at link time. */
3607 if (reloc == 1 && reloc2 == 1)
3608 reloc = 0;
3609 else
3610 reloc |= reloc2;
3611 break;
3612
3613 case NOP_EXPR:
3614 case CONVERT_EXPR:
3615 case NON_LVALUE_EXPR:
3616 case VIEW_CONVERT_EXPR:
3617 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3618 break;
3619
3620 case CONSTRUCTOR:
3621 {
3622 unsigned HOST_WIDE_INT idx;
3623 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
3624 if (tem != 0)
3625 reloc |= compute_reloc_for_constant (tem);
3626 }
3627 break;
3628
3629 default:
3630 break;
3631 }
3632 return reloc;
3633 }
3634
3635 /* Find all the constants whose addresses are referenced inside of EXP,
3636 and make sure assembler code with a label has been output for each one.
3637 Indicate whether an ADDR_EXPR has been encountered. */
3638
3639 static void
output_addressed_constants(tree exp)3640 output_addressed_constants (tree exp)
3641 {
3642 tree tem;
3643
3644 /* Give the front-end a chance to convert VALUE to something that
3645 looks more like a constant to the back-end. */
3646 exp = lang_hooks.expand_constant (exp);
3647
3648 switch (TREE_CODE (exp))
3649 {
3650 case ADDR_EXPR:
3651 case FDESC_EXPR:
3652 /* Go inside any operations that get_inner_reference can handle and see
3653 if what's inside is a constant: no need to do anything here for
3654 addresses of variables or functions. */
3655 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3656 tem = TREE_OPERAND (tem, 0))
3657 ;
3658
3659 /* If we have an initialized CONST_DECL, retrieve the initializer. */
3660 if (TREE_CODE (tem) == CONST_DECL && DECL_INITIAL (tem))
3661 tem = DECL_INITIAL (tem);
3662
3663 if (CONSTANT_CLASS_P (tem) || TREE_CODE (tem) == CONSTRUCTOR)
3664 output_constant_def (tem, 0);
3665 break;
3666
3667 case PLUS_EXPR:
3668 case MINUS_EXPR:
3669 output_addressed_constants (TREE_OPERAND (exp, 1));
3670 /* Fall through. */
3671
3672 case NOP_EXPR:
3673 case CONVERT_EXPR:
3674 case NON_LVALUE_EXPR:
3675 case VIEW_CONVERT_EXPR:
3676 output_addressed_constants (TREE_OPERAND (exp, 0));
3677 break;
3678
3679 case CONSTRUCTOR:
3680 {
3681 unsigned HOST_WIDE_INT idx;
3682 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
3683 if (tem != 0)
3684 output_addressed_constants (tem);
3685 }
3686 break;
3687
3688 default:
3689 break;
3690 }
3691 }
3692
3693 /* Whether a constructor CTOR is a valid static constant initializer if all
3694 its elements are. This used to be internal to initializer_constant_valid_p
3695 and has been exposed to let other functions like categorize_ctor_elements
3696 evaluate the property while walking a constructor for other purposes. */
3697
3698 bool
constructor_static_from_elts_p(tree ctor)3699 constructor_static_from_elts_p (tree ctor)
3700 {
3701 return (TREE_CONSTANT (ctor)
3702 && (TREE_CODE (TREE_TYPE (ctor)) == UNION_TYPE
3703 || TREE_CODE (TREE_TYPE (ctor)) == RECORD_TYPE)
3704 && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (ctor)));
3705 }
3706
3707 /* Return nonzero if VALUE is a valid constant-valued expression
3708 for use in initializing a static variable; one that can be an
3709 element of a "constant" initializer.
3710
3711 Return null_pointer_node if the value is absolute;
3712 if it is relocatable, return the variable that determines the relocation.
3713 We assume that VALUE has been folded as much as possible;
3714 therefore, we do not need to check for such things as
3715 arithmetic-combinations of integers. */
3716
3717 tree
initializer_constant_valid_p(tree value,tree endtype)3718 initializer_constant_valid_p (tree value, tree endtype)
3719 {
3720 /* Give the front-end a chance to convert VALUE to something that
3721 looks more like a constant to the back-end. */
3722 value = lang_hooks.expand_constant (value);
3723
3724 switch (TREE_CODE (value))
3725 {
3726 case CONSTRUCTOR:
3727 if (constructor_static_from_elts_p (value))
3728 {
3729 unsigned HOST_WIDE_INT idx;
3730 tree elt;
3731 bool absolute = true;
3732
3733 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
3734 {
3735 tree reloc;
3736 reloc = initializer_constant_valid_p (elt, TREE_TYPE (elt));
3737 if (!reloc)
3738 return NULL_TREE;
3739 if (reloc != null_pointer_node)
3740 absolute = false;
3741 }
3742 /* For a non-absolute relocation, there is no single
3743 variable that can be "the variable that determines the
3744 relocation." */
3745 return absolute ? null_pointer_node : error_mark_node;
3746 }
3747
3748 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE;
3749
3750 case INTEGER_CST:
3751 case VECTOR_CST:
3752 case REAL_CST:
3753 case STRING_CST:
3754 case COMPLEX_CST:
3755 return null_pointer_node;
3756
3757 case ADDR_EXPR:
3758 case FDESC_EXPR:
3759 value = staticp (TREE_OPERAND (value, 0));
3760 if (value)
3761 {
3762 /* "&(*a).f" is like unto pointer arithmetic. If "a" turns out to
3763 be a constant, this is old-skool offsetof-like nonsense. */
3764 if (TREE_CODE (value) == INDIRECT_REF
3765 && TREE_CONSTANT (TREE_OPERAND (value, 0)))
3766 return null_pointer_node;
3767 /* Taking the address of a nested function involves a trampoline. */
3768 if (TREE_CODE (value) == FUNCTION_DECL
3769 && ((decl_function_context (value)
3770 && !DECL_NO_STATIC_CHAIN (value))
3771 || DECL_DLLIMPORT_P (value)))
3772 return NULL_TREE;
3773 /* "&{...}" requires a temporary to hold the constructed
3774 object. */
3775 if (TREE_CODE (value) == CONSTRUCTOR)
3776 return NULL_TREE;
3777 }
3778 return value;
3779
3780 case VIEW_CONVERT_EXPR:
3781 case NON_LVALUE_EXPR:
3782 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
3783
3784 case CONVERT_EXPR:
3785 case NOP_EXPR:
3786 {
3787 tree src;
3788 tree src_type;
3789 tree dest_type;
3790
3791 src = TREE_OPERAND (value, 0);
3792 src_type = TREE_TYPE (src);
3793 dest_type = TREE_TYPE (value);
3794
3795 /* Allow conversions between pointer types, floating-point
3796 types, and offset types. */
3797 if ((POINTER_TYPE_P (dest_type) && POINTER_TYPE_P (src_type))
3798 || (FLOAT_TYPE_P (dest_type) && FLOAT_TYPE_P (src_type))
3799 || (TREE_CODE (dest_type) == OFFSET_TYPE
3800 && TREE_CODE (src_type) == OFFSET_TYPE))
3801 return initializer_constant_valid_p (src, endtype);
3802
3803 /* Allow length-preserving conversions between integer types. */
3804 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type)
3805 && (TYPE_PRECISION (dest_type) == TYPE_PRECISION (src_type)))
3806 return initializer_constant_valid_p (src, endtype);
3807
3808 /* Allow conversions between other integer types only if
3809 explicit value. */
3810 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type))
3811 {
3812 tree inner = initializer_constant_valid_p (src, endtype);
3813 if (inner == null_pointer_node)
3814 return null_pointer_node;
3815 break;
3816 }
3817
3818 /* Allow (int) &foo provided int is as wide as a pointer. */
3819 if (INTEGRAL_TYPE_P (dest_type) && POINTER_TYPE_P (src_type)
3820 && (TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type)))
3821 return initializer_constant_valid_p (src, endtype);
3822
3823 /* Likewise conversions from int to pointers, but also allow
3824 conversions from 0. */
3825 if ((POINTER_TYPE_P (dest_type)
3826 || TREE_CODE (dest_type) == OFFSET_TYPE)
3827 && INTEGRAL_TYPE_P (src_type))
3828 {
3829 if (TREE_CODE (src) == INTEGER_CST
3830 && TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type))
3831 return null_pointer_node;
3832 if (integer_zerop (src))
3833 return null_pointer_node;
3834 else if (TYPE_PRECISION (dest_type) <= TYPE_PRECISION (src_type))
3835 return initializer_constant_valid_p (src, endtype);
3836 }
3837
3838 /* Allow conversions to struct or union types if the value
3839 inside is okay. */
3840 if (TREE_CODE (dest_type) == RECORD_TYPE
3841 || TREE_CODE (dest_type) == UNION_TYPE)
3842 return initializer_constant_valid_p (src, endtype);
3843 }
3844 break;
3845
3846 case PLUS_EXPR:
3847 if (! INTEGRAL_TYPE_P (endtype)
3848 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
3849 {
3850 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
3851 endtype);
3852 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
3853 endtype);
3854 /* If either term is absolute, use the other terms relocation. */
3855 if (valid0 == null_pointer_node)
3856 return valid1;
3857 if (valid1 == null_pointer_node)
3858 return valid0;
3859 }
3860 break;
3861
3862 case MINUS_EXPR:
3863 if (! INTEGRAL_TYPE_P (endtype)
3864 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
3865 {
3866 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
3867 endtype);
3868 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
3869 endtype);
3870 /* Win if second argument is absolute. */
3871 if (valid1 == null_pointer_node)
3872 return valid0;
3873 /* Win if both arguments have the same relocation.
3874 Then the value is absolute. */
3875 if (valid0 == valid1 && valid0 != 0)
3876 return null_pointer_node;
3877
3878 /* Since GCC guarantees that string constants are unique in the
3879 generated code, a subtraction between two copies of the same
3880 constant string is absolute. */
3881 if (valid0 && TREE_CODE (valid0) == STRING_CST
3882 && valid1 && TREE_CODE (valid1) == STRING_CST
3883 && operand_equal_p (valid0, valid1, 1))
3884 return null_pointer_node;
3885 }
3886
3887 /* Support narrowing differences. */
3888 if (INTEGRAL_TYPE_P (endtype))
3889 {
3890 tree op0, op1;
3891
3892 op0 = TREE_OPERAND (value, 0);
3893 op1 = TREE_OPERAND (value, 1);
3894
3895 /* Like STRIP_NOPS except allow the operand mode to widen.
3896 This works around a feature of fold that simplifies
3897 (int)(p1 - p2) to ((int)p1 - (int)p2) under the theory
3898 that the narrower operation is cheaper. */
3899
3900 while (TREE_CODE (op0) == NOP_EXPR
3901 || TREE_CODE (op0) == CONVERT_EXPR
3902 || TREE_CODE (op0) == NON_LVALUE_EXPR)
3903 {
3904 tree inner = TREE_OPERAND (op0, 0);
3905 if (inner == error_mark_node
3906 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
3907 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))
3908 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
3909 break;
3910 op0 = inner;
3911 }
3912
3913 while (TREE_CODE (op1) == NOP_EXPR
3914 || TREE_CODE (op1) == CONVERT_EXPR
3915 || TREE_CODE (op1) == NON_LVALUE_EXPR)
3916 {
3917 tree inner = TREE_OPERAND (op1, 0);
3918 if (inner == error_mark_node
3919 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
3920 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))
3921 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
3922 break;
3923 op1 = inner;
3924 }
3925
3926 op0 = initializer_constant_valid_p (op0, endtype);
3927 op1 = initializer_constant_valid_p (op1, endtype);
3928
3929 /* Both initializers must be known. */
3930 if (op0 && op1)
3931 {
3932 if (op0 == op1)
3933 return null_pointer_node;
3934
3935 /* Support differences between labels. */
3936 if (TREE_CODE (op0) == LABEL_DECL
3937 && TREE_CODE (op1) == LABEL_DECL)
3938 return null_pointer_node;
3939
3940 if (TREE_CODE (op0) == STRING_CST
3941 && TREE_CODE (op1) == STRING_CST
3942 && operand_equal_p (op0, op1, 1))
3943 return null_pointer_node;
3944 }
3945 }
3946 break;
3947
3948 default:
3949 break;
3950 }
3951
3952 return 0;
3953 }
3954
3955 /* Output assembler code for constant EXP to FILE, with no label.
3956 This includes the pseudo-op such as ".int" or ".byte", and a newline.
3957 Assumes output_addressed_constants has been done on EXP already.
3958
3959 Generate exactly SIZE bytes of assembler data, padding at the end
3960 with zeros if necessary. SIZE must always be specified.
3961
3962 SIZE is important for structure constructors,
3963 since trailing members may have been omitted from the constructor.
3964 It is also important for initialization of arrays from string constants
3965 since the full length of the string constant might not be wanted.
3966 It is also needed for initialization of unions, where the initializer's
3967 type is just one member, and that may not be as long as the union.
3968
3969 There a case in which we would fail to output exactly SIZE bytes:
3970 for a structure constructor that wants to produce more than SIZE bytes.
3971 But such constructors will never be generated for any possible input.
3972
3973 ALIGN is the alignment of the data in bits. */
3974
3975 void
output_constant(tree exp,unsigned HOST_WIDE_INT size,unsigned int align)3976 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
3977 {
3978 enum tree_code code;
3979 unsigned HOST_WIDE_INT thissize;
3980
3981 /* Some front-ends use constants other than the standard language-independent
3982 varieties, but which may still be output directly. Give the front-end a
3983 chance to convert EXP to a language-independent representation. */
3984 exp = lang_hooks.expand_constant (exp);
3985
3986 if (size == 0 || flag_syntax_only)
3987 return;
3988
3989 /* See if we're trying to initialize a pointer in a non-default mode
3990 to the address of some declaration somewhere. If the target says
3991 the mode is valid for pointers, assume the target has a way of
3992 resolving it. */
3993 if (TREE_CODE (exp) == NOP_EXPR
3994 && POINTER_TYPE_P (TREE_TYPE (exp))
3995 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
3996 {
3997 tree saved_type = TREE_TYPE (exp);
3998
3999 /* Peel off any intermediate conversions-to-pointer for valid
4000 pointer modes. */
4001 while (TREE_CODE (exp) == NOP_EXPR
4002 && POINTER_TYPE_P (TREE_TYPE (exp))
4003 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
4004 exp = TREE_OPERAND (exp, 0);
4005
4006 /* If what we're left with is the address of something, we can
4007 convert the address to the final type and output it that
4008 way. */
4009 if (TREE_CODE (exp) == ADDR_EXPR)
4010 exp = build1 (ADDR_EXPR, saved_type, TREE_OPERAND (exp, 0));
4011 /* Likewise for constant ints. */
4012 else if (TREE_CODE (exp) == INTEGER_CST)
4013 exp = build_int_cst_wide (saved_type, TREE_INT_CST_LOW (exp),
4014 TREE_INT_CST_HIGH (exp));
4015
4016 }
4017
4018 /* Eliminate any conversions since we'll be outputting the underlying
4019 constant. */
4020 while (TREE_CODE (exp) == NOP_EXPR || TREE_CODE (exp) == CONVERT_EXPR
4021 || TREE_CODE (exp) == NON_LVALUE_EXPR
4022 || TREE_CODE (exp) == VIEW_CONVERT_EXPR)
4023 {
4024 HOST_WIDE_INT type_size = int_size_in_bytes (TREE_TYPE (exp));
4025 HOST_WIDE_INT op_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (exp, 0)));
4026
4027 /* Make sure eliminating the conversion is really a no-op, except with
4028 VIEW_CONVERT_EXPRs to allow for wild Ada unchecked conversions and
4029 union types to allow for Ada unchecked unions. */
4030 if (type_size > op_size
4031 && TREE_CODE (exp) != VIEW_CONVERT_EXPR
4032 && TREE_CODE (TREE_TYPE (exp)) != UNION_TYPE)
4033 /* Keep the conversion. */
4034 break;
4035 else
4036 exp = TREE_OPERAND (exp, 0);
4037 }
4038
4039 code = TREE_CODE (TREE_TYPE (exp));
4040 thissize = int_size_in_bytes (TREE_TYPE (exp));
4041
4042 /* Give the front end another chance to expand constants. */
4043 exp = lang_hooks.expand_constant (exp);
4044
4045 /* Allow a constructor with no elements for any data type.
4046 This means to fill the space with zeros. */
4047 if (TREE_CODE (exp) == CONSTRUCTOR
4048 && VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (exp)))
4049 {
4050 assemble_zeros (size);
4051 return;
4052 }
4053
4054 if (TREE_CODE (exp) == FDESC_EXPR)
4055 {
4056 #ifdef ASM_OUTPUT_FDESC
4057 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0);
4058 tree decl = TREE_OPERAND (exp, 0);
4059 ASM_OUTPUT_FDESC (asm_out_file, decl, part);
4060 #else
4061 gcc_unreachable ();
4062 #endif
4063 return;
4064 }
4065
4066 /* Now output the underlying data. If we've handling the padding, return.
4067 Otherwise, break and ensure SIZE is the size written. */
4068 switch (code)
4069 {
4070 case BOOLEAN_TYPE:
4071 case INTEGER_TYPE:
4072 case ENUMERAL_TYPE:
4073 case POINTER_TYPE:
4074 case REFERENCE_TYPE:
4075 case OFFSET_TYPE:
4076 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
4077 EXPAND_INITIALIZER),
4078 MIN (size, thissize), align, 0))
4079 error ("initializer for integer value is too complicated");
4080 break;
4081
4082 case REAL_TYPE:
4083 if (TREE_CODE (exp) != REAL_CST)
4084 error ("initializer for floating value is not a floating constant");
4085
4086 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
4087 break;
4088
4089 case COMPLEX_TYPE:
4090 output_constant (TREE_REALPART (exp), thissize / 2, align);
4091 output_constant (TREE_IMAGPART (exp), thissize / 2,
4092 min_align (align, BITS_PER_UNIT * (thissize / 2)));
4093 break;
4094
4095 case ARRAY_TYPE:
4096 case VECTOR_TYPE:
4097 switch (TREE_CODE (exp))
4098 {
4099 case CONSTRUCTOR:
4100 output_constructor (exp, size, align);
4101 return;
4102 case STRING_CST:
4103 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp),
4104 size);
4105 assemble_string (TREE_STRING_POINTER (exp), thissize);
4106 break;
4107
4108 case VECTOR_CST:
4109 {
4110 int elt_size;
4111 tree link;
4112 unsigned int nalign;
4113 enum machine_mode inner;
4114
4115 inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp)));
4116 nalign = MIN (align, GET_MODE_ALIGNMENT (inner));
4117
4118 elt_size = GET_MODE_SIZE (inner);
4119
4120 link = TREE_VECTOR_CST_ELTS (exp);
4121 output_constant (TREE_VALUE (link), elt_size, align);
4122 thissize = elt_size;
4123 while ((link = TREE_CHAIN (link)) != NULL)
4124 {
4125 output_constant (TREE_VALUE (link), elt_size, nalign);
4126 thissize += elt_size;
4127 }
4128 break;
4129 }
4130 default:
4131 gcc_unreachable ();
4132 }
4133 break;
4134
4135 case RECORD_TYPE:
4136 case UNION_TYPE:
4137 gcc_assert (TREE_CODE (exp) == CONSTRUCTOR);
4138 output_constructor (exp, size, align);
4139 return;
4140
4141 case ERROR_MARK:
4142 return;
4143
4144 default:
4145 gcc_unreachable ();
4146 }
4147
4148 if (size > thissize)
4149 assemble_zeros (size - thissize);
4150 }
4151
4152
4153 /* Subroutine of output_constructor, used for computing the size of
4154 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array
4155 type with an unspecified upper bound. */
4156
4157 static unsigned HOST_WIDE_INT
array_size_for_constructor(tree val)4158 array_size_for_constructor (tree val)
4159 {
4160 tree max_index, i;
4161 unsigned HOST_WIDE_INT cnt;
4162 tree index, value, tmp;
4163
4164 /* This code used to attempt to handle string constants that are not
4165 arrays of single-bytes, but nothing else does, so there's no point in
4166 doing it here. */
4167 if (TREE_CODE (val) == STRING_CST)
4168 return TREE_STRING_LENGTH (val);
4169
4170 max_index = NULL_TREE;
4171 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (val), cnt, index, value)
4172 {
4173 if (TREE_CODE (index) == RANGE_EXPR)
4174 index = TREE_OPERAND (index, 1);
4175 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index))
4176 max_index = index;
4177 }
4178
4179 if (max_index == NULL_TREE)
4180 return 0;
4181
4182 /* Compute the total number of array elements. */
4183 tmp = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val)));
4184 i = size_binop (MINUS_EXPR, fold_convert (sizetype, max_index),
4185 fold_convert (sizetype, tmp));
4186 i = size_binop (PLUS_EXPR, i, build_int_cst (sizetype, 1));
4187
4188 /* Multiply by the array element unit size to find number of bytes. */
4189 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val))));
4190
4191 return tree_low_cst (i, 1);
4192 }
4193
4194 /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants).
4195 Generate at least SIZE bytes, padding if necessary. */
4196
4197 static void
output_constructor(tree exp,unsigned HOST_WIDE_INT size,unsigned int align)4198 output_constructor (tree exp, unsigned HOST_WIDE_INT size,
4199 unsigned int align)
4200 {
4201 tree type = TREE_TYPE (exp);
4202 tree field = 0;
4203 tree min_index = 0;
4204 /* Number of bytes output or skipped so far.
4205 In other words, current position within the constructor. */
4206 HOST_WIDE_INT total_bytes = 0;
4207 /* Nonzero means BYTE contains part of a byte, to be output. */
4208 int byte_buffer_in_use = 0;
4209 int byte = 0;
4210 unsigned HOST_WIDE_INT cnt;
4211 constructor_elt *ce;
4212
4213 gcc_assert (HOST_BITS_PER_WIDE_INT >= BITS_PER_UNIT);
4214
4215 if (TREE_CODE (type) == RECORD_TYPE)
4216 field = TYPE_FIELDS (type);
4217
4218 if (TREE_CODE (type) == ARRAY_TYPE
4219 && TYPE_DOMAIN (type) != 0)
4220 min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
4221
4222 /* As LINK goes through the elements of the constant,
4223 FIELD goes through the structure fields, if the constant is a structure.
4224 if the constant is a union, then we override this,
4225 by getting the field from the TREE_LIST element.
4226 But the constant could also be an array. Then FIELD is zero.
4227
4228 There is always a maximum of one element in the chain LINK for unions
4229 (even if the initializer in a source program incorrectly contains
4230 more one). */
4231 for (cnt = 0;
4232 VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (exp), cnt, ce);
4233 cnt++, field = field ? TREE_CHAIN (field) : 0)
4234 {
4235 tree val = ce->value;
4236 tree index = 0;
4237
4238 /* The element in a union constructor specifies the proper field
4239 or index. */
4240 if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE
4241 || TREE_CODE (type) == QUAL_UNION_TYPE)
4242 && ce->index != 0)
4243 field = ce->index;
4244
4245 else if (TREE_CODE (type) == ARRAY_TYPE)
4246 index = ce->index;
4247
4248 #ifdef ASM_COMMENT_START
4249 if (field && flag_verbose_asm)
4250 fprintf (asm_out_file, "%s %s:\n",
4251 ASM_COMMENT_START,
4252 DECL_NAME (field)
4253 ? IDENTIFIER_POINTER (DECL_NAME (field))
4254 : "<anonymous>");
4255 #endif
4256
4257 /* Eliminate the marker that makes a cast not be an lvalue. */
4258 if (val != 0)
4259 STRIP_NOPS (val);
4260
4261 if (index && TREE_CODE (index) == RANGE_EXPR)
4262 {
4263 unsigned HOST_WIDE_INT fieldsize
4264 = int_size_in_bytes (TREE_TYPE (type));
4265 HOST_WIDE_INT lo_index = tree_low_cst (TREE_OPERAND (index, 0), 0);
4266 HOST_WIDE_INT hi_index = tree_low_cst (TREE_OPERAND (index, 1), 0);
4267 HOST_WIDE_INT index;
4268 unsigned int align2 = min_align (align, fieldsize * BITS_PER_UNIT);
4269
4270 for (index = lo_index; index <= hi_index; index++)
4271 {
4272 /* Output the element's initial value. */
4273 if (val == 0)
4274 assemble_zeros (fieldsize);
4275 else
4276 output_constant (val, fieldsize, align2);
4277
4278 /* Count its size. */
4279 total_bytes += fieldsize;
4280 }
4281 }
4282 else if (field == 0 || !DECL_BIT_FIELD (field))
4283 {
4284 /* An element that is not a bit-field. */
4285
4286 unsigned HOST_WIDE_INT fieldsize;
4287 /* Since this structure is static,
4288 we know the positions are constant. */
4289 HOST_WIDE_INT pos = field ? int_byte_position (field) : 0;
4290 unsigned int align2;
4291
4292 if (index != 0)
4293 pos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (val)), 1)
4294 * (tree_low_cst (index, 0) - tree_low_cst (min_index, 0)));
4295
4296 /* Output any buffered-up bit-fields preceding this element. */
4297 if (byte_buffer_in_use)
4298 {
4299 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4300 total_bytes++;
4301 byte_buffer_in_use = 0;
4302 }
4303
4304 /* Advance to offset of this element.
4305 Note no alignment needed in an array, since that is guaranteed
4306 if each element has the proper size. */
4307 if ((field != 0 || index != 0) && pos != total_bytes)
4308 {
4309 gcc_assert (pos >= total_bytes);
4310 assemble_zeros (pos - total_bytes);
4311 total_bytes = pos;
4312 }
4313
4314 /* Find the alignment of this element. */
4315 align2 = min_align (align, BITS_PER_UNIT * pos);
4316
4317 /* Determine size this element should occupy. */
4318 if (field)
4319 {
4320 fieldsize = 0;
4321
4322 /* If this is an array with an unspecified upper bound,
4323 the initializer determines the size. */
4324 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL,
4325 but we cannot do this until the deprecated support for
4326 initializing zero-length array members is removed. */
4327 if (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE
4328 && TYPE_DOMAIN (TREE_TYPE (field))
4329 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (field))))
4330 {
4331 fieldsize = array_size_for_constructor (val);
4332 /* Given a non-empty initialization, this field had
4333 better be last. */
4334 gcc_assert (!fieldsize || !TREE_CHAIN (field));
4335 }
4336 else if (DECL_SIZE_UNIT (field))
4337 {
4338 /* ??? This can't be right. If the decl size overflows
4339 a host integer we will silently emit no data. */
4340 if (host_integerp (DECL_SIZE_UNIT (field), 1))
4341 fieldsize = tree_low_cst (DECL_SIZE_UNIT (field), 1);
4342 }
4343 }
4344 else
4345 fieldsize = int_size_in_bytes (TREE_TYPE (type));
4346
4347 /* Output the element's initial value. */
4348 if (val == 0)
4349 assemble_zeros (fieldsize);
4350 else
4351 output_constant (val, fieldsize, align2);
4352
4353 /* Count its size. */
4354 total_bytes += fieldsize;
4355 }
4356 else if (val != 0 && TREE_CODE (val) != INTEGER_CST)
4357 error ("invalid initial value for member %qs",
4358 IDENTIFIER_POINTER (DECL_NAME (field)));
4359 else
4360 {
4361 /* Element that is a bit-field. */
4362
4363 HOST_WIDE_INT next_offset = int_bit_position (field);
4364 HOST_WIDE_INT end_offset
4365 = (next_offset + tree_low_cst (DECL_SIZE (field), 1));
4366
4367 if (val == 0)
4368 val = integer_zero_node;
4369
4370 /* If this field does not start in this (or, next) byte,
4371 skip some bytes. */
4372 if (next_offset / BITS_PER_UNIT != total_bytes)
4373 {
4374 /* Output remnant of any bit field in previous bytes. */
4375 if (byte_buffer_in_use)
4376 {
4377 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4378 total_bytes++;
4379 byte_buffer_in_use = 0;
4380 }
4381
4382 /* If still not at proper byte, advance to there. */
4383 if (next_offset / BITS_PER_UNIT != total_bytes)
4384 {
4385 gcc_assert (next_offset / BITS_PER_UNIT >= total_bytes);
4386 assemble_zeros (next_offset / BITS_PER_UNIT - total_bytes);
4387 total_bytes = next_offset / BITS_PER_UNIT;
4388 }
4389 }
4390
4391 if (! byte_buffer_in_use)
4392 byte = 0;
4393
4394 /* We must split the element into pieces that fall within
4395 separate bytes, and combine each byte with previous or
4396 following bit-fields. */
4397
4398 /* next_offset is the offset n fbits from the beginning of
4399 the structure to the next bit of this element to be processed.
4400 end_offset is the offset of the first bit past the end of
4401 this element. */
4402 while (next_offset < end_offset)
4403 {
4404 int this_time;
4405 int shift;
4406 HOST_WIDE_INT value;
4407 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
4408 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
4409
4410 /* Advance from byte to byte
4411 within this element when necessary. */
4412 while (next_byte != total_bytes)
4413 {
4414 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4415 total_bytes++;
4416 byte = 0;
4417 }
4418
4419 /* Number of bits we can process at once
4420 (all part of the same byte). */
4421 this_time = MIN (end_offset - next_offset,
4422 BITS_PER_UNIT - next_bit);
4423 if (BYTES_BIG_ENDIAN)
4424 {
4425 /* On big-endian machine, take the most significant bits
4426 first (of the bits that are significant)
4427 and put them into bytes from the most significant end. */
4428 shift = end_offset - next_offset - this_time;
4429
4430 /* Don't try to take a bunch of bits that cross
4431 the word boundary in the INTEGER_CST. We can
4432 only select bits from the LOW or HIGH part
4433 not from both. */
4434 if (shift < HOST_BITS_PER_WIDE_INT
4435 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4436 {
4437 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT;
4438 shift = HOST_BITS_PER_WIDE_INT;
4439 }
4440
4441 /* Now get the bits from the appropriate constant word. */
4442 if (shift < HOST_BITS_PER_WIDE_INT)
4443 value = TREE_INT_CST_LOW (val);
4444 else
4445 {
4446 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4447 value = TREE_INT_CST_HIGH (val);
4448 shift -= HOST_BITS_PER_WIDE_INT;
4449 }
4450
4451 /* Get the result. This works only when:
4452 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4453 byte |= (((value >> shift)
4454 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4455 << (BITS_PER_UNIT - this_time - next_bit));
4456 }
4457 else
4458 {
4459 /* On little-endian machines,
4460 take first the least significant bits of the value
4461 and pack them starting at the least significant
4462 bits of the bytes. */
4463 shift = next_offset - int_bit_position (field);
4464
4465 /* Don't try to take a bunch of bits that cross
4466 the word boundary in the INTEGER_CST. We can
4467 only select bits from the LOW or HIGH part
4468 not from both. */
4469 if (shift < HOST_BITS_PER_WIDE_INT
4470 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4471 this_time = (HOST_BITS_PER_WIDE_INT - shift);
4472
4473 /* Now get the bits from the appropriate constant word. */
4474 if (shift < HOST_BITS_PER_WIDE_INT)
4475 value = TREE_INT_CST_LOW (val);
4476 else
4477 {
4478 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4479 value = TREE_INT_CST_HIGH (val);
4480 shift -= HOST_BITS_PER_WIDE_INT;
4481 }
4482
4483 /* Get the result. This works only when:
4484 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4485 byte |= (((value >> shift)
4486 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4487 << next_bit);
4488 }
4489
4490 next_offset += this_time;
4491 byte_buffer_in_use = 1;
4492 }
4493 }
4494 }
4495
4496 if (byte_buffer_in_use)
4497 {
4498 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4499 total_bytes++;
4500 }
4501
4502 if ((unsigned HOST_WIDE_INT)total_bytes < size)
4503 assemble_zeros (size - total_bytes);
4504 }
4505
4506 /* This TREE_LIST contains any weak symbol declarations waiting
4507 to be emitted. */
4508 static GTY(()) tree weak_decls;
4509
4510 /* Mark DECL as weak. */
4511
4512 static void
mark_weak(tree decl)4513 mark_weak (tree decl)
4514 {
4515 DECL_WEAK (decl) = 1;
4516
4517 if (DECL_RTL_SET_P (decl)
4518 && MEM_P (DECL_RTL (decl))
4519 && XEXP (DECL_RTL (decl), 0)
4520 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF)
4521 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1;
4522 }
4523
4524 /* Merge weak status between NEWDECL and OLDDECL. */
4525
4526 void
merge_weak(tree newdecl,tree olddecl)4527 merge_weak (tree newdecl, tree olddecl)
4528 {
4529 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl))
4530 {
4531 if (DECL_WEAK (newdecl) && SUPPORTS_WEAK)
4532 {
4533 tree *pwd;
4534 /* We put the NEWDECL on the weak_decls list at some point
4535 and OLDDECL as well. Keep just OLDDECL on the list. */
4536 for (pwd = &weak_decls; *pwd; pwd = &TREE_CHAIN (*pwd))
4537 if (TREE_VALUE (*pwd) == newdecl)
4538 {
4539 *pwd = TREE_CHAIN (*pwd);
4540 break;
4541 }
4542 }
4543 return;
4544 }
4545
4546 if (DECL_WEAK (newdecl))
4547 {
4548 tree wd;
4549
4550 /* NEWDECL is weak, but OLDDECL is not. */
4551
4552 /* If we already output the OLDDECL, we're in trouble; we can't
4553 go back and make it weak. This error cannot caught in
4554 declare_weak because the NEWDECL and OLDDECL was not yet
4555 been merged; therefore, TREE_ASM_WRITTEN was not set. */
4556 if (TREE_ASM_WRITTEN (olddecl))
4557 error ("weak declaration of %q+D must precede definition",
4558 newdecl);
4559
4560 /* If we've already generated rtl referencing OLDDECL, we may
4561 have done so in a way that will not function properly with
4562 a weak symbol. */
4563 else if (TREE_USED (olddecl)
4564 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl)))
4565 warning (0, "weak declaration of %q+D after first use results "
4566 "in unspecified behavior", newdecl);
4567
4568 if (SUPPORTS_WEAK)
4569 {
4570 /* We put the NEWDECL on the weak_decls list at some point.
4571 Replace it with the OLDDECL. */
4572 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd))
4573 if (TREE_VALUE (wd) == newdecl)
4574 {
4575 TREE_VALUE (wd) = olddecl;
4576 break;
4577 }
4578 /* We may not find the entry on the list. If NEWDECL is a
4579 weak alias, then we will have already called
4580 globalize_decl to remove the entry; in that case, we do
4581 not need to do anything. */
4582 }
4583
4584 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */
4585 mark_weak (olddecl);
4586 }
4587 else
4588 /* OLDDECL was weak, but NEWDECL was not explicitly marked as
4589 weak. Just update NEWDECL to indicate that it's weak too. */
4590 mark_weak (newdecl);
4591 }
4592
4593 /* Declare DECL to be a weak symbol. */
4594
4595 void
declare_weak(tree decl)4596 declare_weak (tree decl)
4597 {
4598 if (! TREE_PUBLIC (decl))
4599 error ("weak declaration of %q+D must be public", decl);
4600 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl))
4601 error ("weak declaration of %q+D must precede definition", decl);
4602 else if (SUPPORTS_WEAK)
4603 {
4604 if (! DECL_WEAK (decl))
4605 weak_decls = tree_cons (NULL, decl, weak_decls);
4606 }
4607 else
4608 warning (0, "weak declaration of %q+D not supported", decl);
4609
4610 mark_weak (decl);
4611 }
4612
4613 static void
weak_finish_1(tree decl)4614 weak_finish_1 (tree decl)
4615 {
4616 #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL)
4617 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4618 #endif
4619
4620 if (! TREE_USED (decl))
4621 return;
4622
4623 #ifdef ASM_WEAKEN_DECL
4624 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL);
4625 #else
4626 #ifdef ASM_WEAKEN_LABEL
4627 ASM_WEAKEN_LABEL (asm_out_file, name);
4628 #else
4629 #ifdef ASM_OUTPUT_WEAK_ALIAS
4630 {
4631 static bool warn_once = 0;
4632 if (! warn_once)
4633 {
4634 warning (0, "only weak aliases are supported in this configuration");
4635 warn_once = 1;
4636 }
4637 return;
4638 }
4639 #endif
4640 #endif
4641 #endif
4642 }
4643
4644 /* This TREE_LIST contains weakref targets. */
4645
4646 static GTY(()) tree weakref_targets;
4647
4648 /* Forward declaration. */
4649 static tree find_decl_and_mark_needed (tree decl, tree target);
4650
4651 /* Emit any pending weak declarations. */
4652
4653 void
weak_finish(void)4654 weak_finish (void)
4655 {
4656 tree t;
4657
4658 for (t = weakref_targets; t; t = TREE_CHAIN (t))
4659 {
4660 tree alias_decl = TREE_PURPOSE (t);
4661 tree target = ultimate_transparent_alias_target (&TREE_VALUE (t));
4662
4663 if (! TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (alias_decl)))
4664 /* Remove alias_decl from the weak list, but leave entries for
4665 the target alone. */
4666 target = NULL_TREE;
4667 #ifndef ASM_OUTPUT_WEAKREF
4668 else if (! TREE_SYMBOL_REFERENCED (target))
4669 {
4670 /* Use ASM_WEAKEN_LABEL only if ASM_WEAKEN_DECL is not
4671 defined, otherwise we and weak_finish_1 would use a
4672 different macros. */
4673 # if defined ASM_WEAKEN_LABEL && ! defined ASM_WEAKEN_DECL
4674 ASM_WEAKEN_LABEL (asm_out_file, IDENTIFIER_POINTER (target));
4675 # else
4676 tree decl = find_decl_and_mark_needed (alias_decl, target);
4677
4678 if (! decl)
4679 {
4680 decl = build_decl (TREE_CODE (alias_decl), target,
4681 TREE_TYPE (alias_decl));
4682
4683 DECL_EXTERNAL (decl) = 1;
4684 TREE_PUBLIC (decl) = 1;
4685 DECL_ARTIFICIAL (decl) = 1;
4686 TREE_NOTHROW (decl) = TREE_NOTHROW (alias_decl);
4687 TREE_USED (decl) = 1;
4688 }
4689
4690 weak_finish_1 (decl);
4691 # endif
4692 }
4693 #endif
4694
4695 {
4696 tree *p;
4697 tree t2;
4698
4699 /* Remove the alias and the target from the pending weak list
4700 so that we do not emit any .weak directives for the former,
4701 nor multiple .weak directives for the latter. */
4702 for (p = &weak_decls; (t2 = *p) ; )
4703 {
4704 if (TREE_VALUE (t2) == alias_decl
4705 || target == DECL_ASSEMBLER_NAME (TREE_VALUE (t2)))
4706 *p = TREE_CHAIN (t2);
4707 else
4708 p = &TREE_CHAIN (t2);
4709 }
4710
4711 /* Remove other weakrefs to the same target, to speed things up. */
4712 for (p = &TREE_CHAIN (t); (t2 = *p) ; )
4713 {
4714 if (target == ultimate_transparent_alias_target (&TREE_VALUE (t2)))
4715 *p = TREE_CHAIN (t2);
4716 else
4717 p = &TREE_CHAIN (t2);
4718 }
4719 }
4720 }
4721
4722 for (t = weak_decls; t; t = TREE_CHAIN (t))
4723 {
4724 tree decl = TREE_VALUE (t);
4725
4726 weak_finish_1 (decl);
4727 }
4728 }
4729
4730 /* Emit the assembly bits to indicate that DECL is globally visible. */
4731
4732 static void
globalize_decl(tree decl)4733 globalize_decl (tree decl)
4734 {
4735 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
4736
4737 #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL)
4738 if (DECL_WEAK (decl))
4739 {
4740 tree *p, t;
4741
4742 #ifdef ASM_WEAKEN_DECL
4743 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
4744 #else
4745 ASM_WEAKEN_LABEL (asm_out_file, name);
4746 #endif
4747
4748 /* Remove this function from the pending weak list so that
4749 we do not emit multiple .weak directives for it. */
4750 for (p = &weak_decls; (t = *p) ; )
4751 {
4752 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
4753 *p = TREE_CHAIN (t);
4754 else
4755 p = &TREE_CHAIN (t);
4756 }
4757
4758 /* Remove weakrefs to the same target from the pending weakref
4759 list, for the same reason. */
4760 for (p = &weakref_targets; (t = *p) ; )
4761 {
4762 if (DECL_ASSEMBLER_NAME (decl)
4763 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
4764 *p = TREE_CHAIN (t);
4765 else
4766 p = &TREE_CHAIN (t);
4767 }
4768
4769 return;
4770 }
4771 #elif defined(ASM_MAKE_LABEL_LINKONCE)
4772 if (DECL_ONE_ONLY (decl))
4773 ASM_MAKE_LABEL_LINKONCE (asm_out_file, name);
4774 #endif
4775
4776 targetm.asm_out.globalize_label (asm_out_file, name);
4777 }
4778
4779 /* We have to be able to tell cgraph about the needed-ness of the target
4780 of an alias. This requires that the decl have been defined. Aliases
4781 that precede their definition have to be queued for later processing. */
4782
4783 typedef struct alias_pair GTY(())
4784 {
4785 tree decl;
4786 tree target;
4787 } alias_pair;
4788
4789 /* Define gc'd vector type. */
4790 DEF_VEC_O(alias_pair);
4791 DEF_VEC_ALLOC_O(alias_pair,gc);
4792
4793 static GTY(()) VEC(alias_pair,gc) *alias_pairs;
4794
4795 /* Given an assembly name, find the decl it is associated with. At the
4796 same time, mark it needed for cgraph. */
4797
4798 static tree
find_decl_and_mark_needed(tree decl,tree target)4799 find_decl_and_mark_needed (tree decl, tree target)
4800 {
4801 struct cgraph_node *fnode = NULL;
4802 struct cgraph_varpool_node *vnode = NULL;
4803
4804 if (TREE_CODE (decl) == FUNCTION_DECL)
4805 {
4806 fnode = cgraph_node_for_asm (target);
4807 if (fnode == NULL)
4808 vnode = cgraph_varpool_node_for_asm (target);
4809 }
4810 else
4811 {
4812 vnode = cgraph_varpool_node_for_asm (target);
4813 if (vnode == NULL)
4814 fnode = cgraph_node_for_asm (target);
4815 }
4816
4817 if (fnode)
4818 {
4819 /* We can't mark function nodes as used after cgraph global info
4820 is finished. This wouldn't generally be necessary, but C++
4821 virtual table thunks are introduced late in the game and
4822 might seem like they need marking, although in fact they
4823 don't. */
4824 if (! cgraph_global_info_ready)
4825 cgraph_mark_needed_node (fnode);
4826 return fnode->decl;
4827 }
4828 else if (vnode)
4829 {
4830 cgraph_varpool_mark_needed_node (vnode);
4831 return vnode->decl;
4832 }
4833 else
4834 return NULL_TREE;
4835 }
4836
4837 /* Output the assembler code for a define (equate) using ASM_OUTPUT_DEF
4838 or ASM_OUTPUT_DEF_FROM_DECLS. The function defines the symbol whose
4839 tree node is DECL to have the value of the tree node TARGET. */
4840
4841 static void
do_assemble_alias(tree decl,tree target)4842 do_assemble_alias (tree decl, tree target)
4843 {
4844 if (TREE_ASM_WRITTEN (decl))
4845 return;
4846
4847 TREE_ASM_WRITTEN (decl) = 1;
4848 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;
4849
4850 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
4851 {
4852 ultimate_transparent_alias_target (&target);
4853
4854 if (!TREE_SYMBOL_REFERENCED (target))
4855 weakref_targets = tree_cons (decl, target, weakref_targets);
4856
4857 #ifdef ASM_OUTPUT_WEAKREF
4858 ASM_OUTPUT_WEAKREF (asm_out_file, decl,
4859 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
4860 IDENTIFIER_POINTER (target));
4861 #else
4862 if (!SUPPORTS_WEAK)
4863 {
4864 error ("%Jweakref is not supported in this configuration", decl);
4865 return;
4866 }
4867 #endif
4868 return;
4869 }
4870
4871 #ifdef ASM_OUTPUT_DEF
4872 /* Make name accessible from other files, if appropriate. */
4873
4874 if (TREE_PUBLIC (decl))
4875 {
4876 globalize_decl (decl);
4877 maybe_assemble_visibility (decl);
4878 }
4879
4880 # ifdef ASM_OUTPUT_DEF_FROM_DECLS
4881 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target);
4882 # else
4883 ASM_OUTPUT_DEF (asm_out_file,
4884 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
4885 IDENTIFIER_POINTER (target));
4886 # endif
4887 #elif defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
4888 {
4889 const char *name;
4890 tree *p, t;
4891
4892 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4893 # ifdef ASM_WEAKEN_DECL
4894 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target));
4895 # else
4896 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
4897 # endif
4898 /* Remove this function from the pending weak list so that
4899 we do not emit multiple .weak directives for it. */
4900 for (p = &weak_decls; (t = *p) ; )
4901 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
4902 *p = TREE_CHAIN (t);
4903 else
4904 p = &TREE_CHAIN (t);
4905
4906 /* Remove weakrefs to the same target from the pending weakref
4907 list, for the same reason. */
4908 for (p = &weakref_targets; (t = *p) ; )
4909 {
4910 if (DECL_ASSEMBLER_NAME (decl)
4911 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
4912 *p = TREE_CHAIN (t);
4913 else
4914 p = &TREE_CHAIN (t);
4915 }
4916 }
4917 #endif
4918 }
4919
4920 /* First pass of completing pending aliases. Make sure that cgraph knows
4921 which symbols will be required. */
4922
4923 void
finish_aliases_1(void)4924 finish_aliases_1 (void)
4925 {
4926 unsigned i;
4927 alias_pair *p;
4928
4929 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
4930 {
4931 tree target_decl;
4932
4933 target_decl = find_decl_and_mark_needed (p->decl, p->target);
4934 if (target_decl == NULL)
4935 {
4936 if (! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
4937 error ("%q+D aliased to undefined symbol %qs",
4938 p->decl, IDENTIFIER_POINTER (p->target));
4939 }
4940 else if (DECL_EXTERNAL (target_decl)
4941 && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
4942 error ("%q+D aliased to external symbol %qs",
4943 p->decl, IDENTIFIER_POINTER (p->target));
4944 }
4945 }
4946
4947 /* Second pass of completing pending aliases. Emit the actual assembly.
4948 This happens at the end of compilation and thus it is assured that the
4949 target symbol has been emitted. */
4950
4951 void
finish_aliases_2(void)4952 finish_aliases_2 (void)
4953 {
4954 unsigned i;
4955 alias_pair *p;
4956
4957 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
4958 do_assemble_alias (p->decl, p->target);
4959
4960 VEC_truncate (alias_pair, alias_pairs, 0);
4961 }
4962
4963 /* Emit an assembler directive to make the symbol for DECL an alias to
4964 the symbol for TARGET. */
4965
4966 void
assemble_alias(tree decl,tree target)4967 assemble_alias (tree decl, tree target)
4968 {
4969 tree target_decl;
4970 bool is_weakref = false;
4971
4972 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
4973 {
4974 tree alias = DECL_ASSEMBLER_NAME (decl);
4975
4976 is_weakref = true;
4977
4978 ultimate_transparent_alias_target (&target);
4979
4980 if (alias == target)
4981 error ("weakref %q+D ultimately targets itself", decl);
4982 else
4983 {
4984 #ifndef ASM_OUTPUT_WEAKREF
4985 IDENTIFIER_TRANSPARENT_ALIAS (alias) = 1;
4986 TREE_CHAIN (alias) = target;
4987 #endif
4988 }
4989 if (TREE_PUBLIC (decl))
4990 error ("weakref %q+D must have static linkage", decl);
4991 }
4992 else
4993 {
4994 #if !defined (ASM_OUTPUT_DEF)
4995 # if !defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL)
4996 error ("%Jalias definitions not supported in this configuration", decl);
4997 return;
4998 # else
4999 if (!DECL_WEAK (decl))
5000 {
5001 error ("%Jonly weak aliases are supported in this configuration", decl);
5002 return;
5003 }
5004 # endif
5005 #endif
5006 }
5007
5008 /* We must force creation of DECL_RTL for debug info generation, even though
5009 we don't use it here. */
5010 make_decl_rtl (decl);
5011 TREE_USED (decl) = 1;
5012
5013 /* A quirk of the initial implementation of aliases required that the user
5014 add "extern" to all of them. Which is silly, but now historical. Do
5015 note that the symbol is in fact locally defined. */
5016 if (! is_weakref)
5017 DECL_EXTERNAL (decl) = 0;
5018
5019 /* Allow aliases to aliases. */
5020 if (TREE_CODE (decl) == FUNCTION_DECL)
5021 cgraph_node (decl)->alias = true;
5022 else
5023 cgraph_varpool_node (decl)->alias = true;
5024
5025 /* If the target has already been emitted, we don't have to queue the
5026 alias. This saves a tad o memory. */
5027 target_decl = find_decl_and_mark_needed (decl, target);
5028 if (target_decl && TREE_ASM_WRITTEN (target_decl))
5029 do_assemble_alias (decl, target);
5030 else
5031 {
5032 alias_pair *p = VEC_safe_push (alias_pair, gc, alias_pairs, NULL);
5033 p->decl = decl;
5034 p->target = target;
5035 }
5036 }
5037
5038 /* Emit an assembler directive to set symbol for DECL visibility to
5039 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */
5040
5041 void
default_assemble_visibility(tree decl,int vis)5042 default_assemble_visibility (tree decl, int vis)
5043 {
5044 static const char * const visibility_types[] = {
5045 NULL, "protected", "hidden", "internal"
5046 };
5047
5048 const char *name, *type;
5049
5050 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5051 type = visibility_types[vis];
5052
5053 #ifdef HAVE_GAS_HIDDEN
5054 fprintf (asm_out_file, "\t.%s\t", type);
5055 assemble_name (asm_out_file, name);
5056 fprintf (asm_out_file, "\n");
5057 #else
5058 warning (OPT_Wattributes, "visibility attribute not supported "
5059 "in this configuration; ignored");
5060 #endif
5061 }
5062
5063 /* A helper function to call assemble_visibility when needed for a decl. */
5064
5065 int
maybe_assemble_visibility(tree decl)5066 maybe_assemble_visibility (tree decl)
5067 {
5068 enum symbol_visibility vis = DECL_VISIBILITY (decl);
5069
5070 if (vis != VISIBILITY_DEFAULT)
5071 {
5072 targetm.asm_out.visibility (decl, vis);
5073 return 1;
5074 }
5075 else
5076 return 0;
5077 }
5078
5079 /* Returns 1 if the target configuration supports defining public symbols
5080 so that one of them will be chosen at link time instead of generating a
5081 multiply-defined symbol error, whether through the use of weak symbols or
5082 a target-specific mechanism for having duplicates discarded. */
5083
5084 int
supports_one_only(void)5085 supports_one_only (void)
5086 {
5087 if (SUPPORTS_ONE_ONLY)
5088 return 1;
5089 return SUPPORTS_WEAK;
5090 }
5091
5092 /* Set up DECL as a public symbol that can be defined in multiple
5093 translation units without generating a linker error. */
5094
5095 void
make_decl_one_only(tree decl)5096 make_decl_one_only (tree decl)
5097 {
5098 gcc_assert (TREE_CODE (decl) == VAR_DECL
5099 || TREE_CODE (decl) == FUNCTION_DECL);
5100
5101 TREE_PUBLIC (decl) = 1;
5102
5103 if (SUPPORTS_ONE_ONLY)
5104 {
5105 #ifdef MAKE_DECL_ONE_ONLY
5106 MAKE_DECL_ONE_ONLY (decl);
5107 #endif
5108 DECL_ONE_ONLY (decl) = 1;
5109 }
5110 else if (TREE_CODE (decl) == VAR_DECL
5111 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
5112 DECL_COMMON (decl) = 1;
5113 else
5114 {
5115 gcc_assert (SUPPORTS_WEAK);
5116 DECL_WEAK (decl) = 1;
5117 }
5118 }
5119
5120 void
init_varasm_once(void)5121 init_varasm_once (void)
5122 {
5123 section_htab = htab_create_ggc (31, section_entry_hash,
5124 section_entry_eq, NULL);
5125 object_block_htab = htab_create_ggc (31, object_block_entry_hash,
5126 object_block_entry_eq, NULL);
5127 const_desc_htab = htab_create_ggc (1009, const_desc_hash,
5128 const_desc_eq, NULL);
5129
5130 const_alias_set = new_alias_set ();
5131 shared_constant_pool = create_constant_pool ();
5132
5133 #ifdef TEXT_SECTION_ASM_OP
5134 text_section = get_unnamed_section (SECTION_CODE, output_section_asm_op,
5135 TEXT_SECTION_ASM_OP);
5136 #endif
5137
5138 #ifdef DATA_SECTION_ASM_OP
5139 data_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5140 DATA_SECTION_ASM_OP);
5141 #endif
5142
5143 #ifdef SDATA_SECTION_ASM_OP
5144 sdata_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5145 SDATA_SECTION_ASM_OP);
5146 #endif
5147
5148 #ifdef READONLY_DATA_SECTION_ASM_OP
5149 readonly_data_section = get_unnamed_section (0, output_section_asm_op,
5150 READONLY_DATA_SECTION_ASM_OP);
5151 #endif
5152
5153 #ifdef CTORS_SECTION_ASM_OP
5154 ctors_section = get_unnamed_section (0, output_section_asm_op,
5155 CTORS_SECTION_ASM_OP);
5156 #endif
5157
5158 #ifdef DTORS_SECTION_ASM_OP
5159 dtors_section = get_unnamed_section (0, output_section_asm_op,
5160 DTORS_SECTION_ASM_OP);
5161 #endif
5162
5163 #ifdef BSS_SECTION_ASM_OP
5164 bss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5165 output_section_asm_op,
5166 BSS_SECTION_ASM_OP);
5167 #endif
5168
5169 #ifdef SBSS_SECTION_ASM_OP
5170 sbss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5171 output_section_asm_op,
5172 SBSS_SECTION_ASM_OP);
5173 #endif
5174
5175 tls_comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5176 | SECTION_COMMON, emit_tls_common);
5177 lcomm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5178 | SECTION_COMMON, emit_local);
5179 comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5180 | SECTION_COMMON, emit_common);
5181
5182 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
5183 bss_noswitch_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS,
5184 emit_bss);
5185 #endif
5186
5187 targetm.asm_out.init_sections ();
5188
5189 if (readonly_data_section == NULL)
5190 readonly_data_section = text_section;
5191 }
5192
5193 enum tls_model
decl_default_tls_model(tree decl)5194 decl_default_tls_model (tree decl)
5195 {
5196 enum tls_model kind;
5197 bool is_local;
5198
5199 is_local = targetm.binds_local_p (decl);
5200 if (!flag_shlib)
5201 {
5202 if (is_local)
5203 kind = TLS_MODEL_LOCAL_EXEC;
5204 else
5205 kind = TLS_MODEL_INITIAL_EXEC;
5206 }
5207
5208 /* Local dynamic is inefficient when we're not combining the
5209 parts of the address. */
5210 else if (optimize && is_local)
5211 kind = TLS_MODEL_LOCAL_DYNAMIC;
5212 else
5213 kind = TLS_MODEL_GLOBAL_DYNAMIC;
5214 if (kind < flag_tls_default)
5215 kind = flag_tls_default;
5216
5217 return kind;
5218 }
5219
5220 /* Select a set of attributes for section NAME based on the properties
5221 of DECL and whether or not RELOC indicates that DECL's initializer
5222 might contain runtime relocations.
5223
5224 We make the section read-only and executable for a function decl,
5225 read-only for a const data decl, and writable for a non-const data decl. */
5226
5227 unsigned int
default_section_type_flags(tree decl,const char * name,int reloc)5228 default_section_type_flags (tree decl, const char *name, int reloc)
5229 {
5230 unsigned int flags;
5231
5232 if (decl && TREE_CODE (decl) == FUNCTION_DECL)
5233 flags = SECTION_CODE;
5234 else if (decl && decl_readonly_section (decl, reloc))
5235 flags = 0;
5236 else if (current_function_decl
5237 && cfun
5238 && cfun->unlikely_text_section_name
5239 && strcmp (name, cfun->unlikely_text_section_name) == 0)
5240 flags = SECTION_CODE;
5241 else if (!decl
5242 && (!current_function_decl || !cfun)
5243 && strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
5244 flags = SECTION_CODE;
5245 else
5246 flags = SECTION_WRITE;
5247
5248 if (decl && DECL_ONE_ONLY (decl))
5249 flags |= SECTION_LINKONCE;
5250
5251 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
5252 flags |= SECTION_TLS | SECTION_WRITE;
5253
5254 if (strcmp (name, ".bss") == 0
5255 || strncmp (name, ".bss.", 5) == 0
5256 || strncmp (name, ".gnu.linkonce.b.", 16) == 0
5257 || strcmp (name, ".sbss") == 0
5258 || strncmp (name, ".sbss.", 6) == 0
5259 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0)
5260 flags |= SECTION_BSS;
5261
5262 if (strcmp (name, ".tdata") == 0
5263 || strncmp (name, ".tdata.", 7) == 0
5264 || strncmp (name, ".gnu.linkonce.td.", 17) == 0)
5265 flags |= SECTION_TLS;
5266
5267 if (strcmp (name, ".tbss") == 0
5268 || strncmp (name, ".tbss.", 6) == 0
5269 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
5270 flags |= SECTION_TLS | SECTION_BSS;
5271
5272 /* These three sections have special ELF types. They are neither
5273 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't
5274 want to print a section type (@progbits or @nobits). If someone
5275 is silly enough to emit code or TLS variables to one of these
5276 sections, then don't handle them specially. */
5277 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS))
5278 && (strcmp (name, ".init_array") == 0
5279 || strcmp (name, ".fini_array") == 0
5280 || strcmp (name, ".preinit_array") == 0))
5281 flags |= SECTION_NOTYPE;
5282
5283 return flags;
5284 }
5285
5286 /* Return true if the target supports some form of global BSS,
5287 either through bss_noswitch_section, or by selecting a BSS
5288 section in TARGET_ASM_SELECT_SECTION. */
5289
5290 bool
have_global_bss_p(void)5291 have_global_bss_p (void)
5292 {
5293 return bss_noswitch_section || targetm.have_switchable_bss_sections;
5294 }
5295
5296 /* Output assembly to switch to section NAME with attribute FLAGS.
5297 Four variants for common object file formats. */
5298
5299 void
default_no_named_section(const char * name ATTRIBUTE_UNUSED,unsigned int flags ATTRIBUTE_UNUSED,tree decl ATTRIBUTE_UNUSED)5300 default_no_named_section (const char *name ATTRIBUTE_UNUSED,
5301 unsigned int flags ATTRIBUTE_UNUSED,
5302 tree decl ATTRIBUTE_UNUSED)
5303 {
5304 /* Some object formats don't support named sections at all. The
5305 front-end should already have flagged this as an error. */
5306 gcc_unreachable ();
5307 }
5308
5309 void
default_elf_asm_named_section(const char * name,unsigned int flags,tree decl ATTRIBUTE_UNUSED)5310 default_elf_asm_named_section (const char *name, unsigned int flags,
5311 tree decl ATTRIBUTE_UNUSED)
5312 {
5313 char flagchars[10], *f = flagchars;
5314
5315 /* If we have already declared this section, we can use an
5316 abbreviated form to switch back to it -- unless this section is
5317 part of a COMDAT groups, in which case GAS requires the full
5318 declaration every time. */
5319 if (!(HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5320 && (flags & SECTION_DECLARED))
5321 {
5322 fprintf (asm_out_file, "\t.section\t%s\n", name);
5323 return;
5324 }
5325
5326 if (!(flags & SECTION_DEBUG))
5327 *f++ = 'a';
5328 if (flags & SECTION_WRITE)
5329 *f++ = 'w';
5330 if (flags & SECTION_CODE)
5331 *f++ = 'x';
5332 if (flags & SECTION_SMALL)
5333 *f++ = 's';
5334 if (flags & SECTION_MERGE)
5335 *f++ = 'M';
5336 if (flags & SECTION_STRINGS)
5337 *f++ = 'S';
5338 if (flags & SECTION_TLS)
5339 *f++ = 'T';
5340 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5341 *f++ = 'G';
5342 *f = '\0';
5343
5344 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);
5345
5346 if (!(flags & SECTION_NOTYPE))
5347 {
5348 const char *type;
5349 const char *format;
5350
5351 if (flags & SECTION_BSS)
5352 type = "nobits";
5353 else
5354 type = "progbits";
5355
5356 format = ",@%s";
5357 #ifdef ASM_COMMENT_START
5358 /* On platforms that use "@" as the assembly comment character,
5359 use "%" instead. */
5360 if (strcmp (ASM_COMMENT_START, "@") == 0)
5361 format = ",%%%s";
5362 #endif
5363 fprintf (asm_out_file, format, type);
5364
5365 if (flags & SECTION_ENTSIZE)
5366 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
5367 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5368 fprintf (asm_out_file, ",%s,comdat",
5369 lang_hooks.decls.comdat_group (decl));
5370 }
5371
5372 putc ('\n', asm_out_file);
5373 }
5374
5375 void
default_coff_asm_named_section(const char * name,unsigned int flags,tree decl ATTRIBUTE_UNUSED)5376 default_coff_asm_named_section (const char *name, unsigned int flags,
5377 tree decl ATTRIBUTE_UNUSED)
5378 {
5379 char flagchars[8], *f = flagchars;
5380
5381 if (flags & SECTION_WRITE)
5382 *f++ = 'w';
5383 if (flags & SECTION_CODE)
5384 *f++ = 'x';
5385 *f = '\0';
5386
5387 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);
5388 }
5389
5390 void
default_pe_asm_named_section(const char * name,unsigned int flags,tree decl)5391 default_pe_asm_named_section (const char *name, unsigned int flags,
5392 tree decl)
5393 {
5394 default_coff_asm_named_section (name, flags, decl);
5395
5396 if (flags & SECTION_LINKONCE)
5397 {
5398 /* Functions may have been compiled at various levels of
5399 optimization so we can't use `same_size' here.
5400 Instead, have the linker pick one. */
5401 fprintf (asm_out_file, "\t.linkonce %s\n",
5402 (flags & SECTION_CODE ? "discard" : "same_size"));
5403 }
5404 }
5405
5406 /* The lame default section selector. */
5407
5408 section *
default_select_section(tree decl,int reloc,unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)5409 default_select_section (tree decl, int reloc,
5410 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
5411 {
5412 if (DECL_P (decl))
5413 {
5414 if (decl_readonly_section (decl, reloc))
5415 return readonly_data_section;
5416 }
5417 else if (TREE_CODE (decl) == CONSTRUCTOR)
5418 {
5419 if (! ((flag_pic && reloc)
5420 || !TREE_READONLY (decl)
5421 || TREE_SIDE_EFFECTS (decl)
5422 || !TREE_CONSTANT (decl)))
5423 return readonly_data_section;
5424 }
5425 else if (TREE_CODE (decl) == STRING_CST)
5426 return readonly_data_section;
5427 else if (! (flag_pic && reloc))
5428 return readonly_data_section;
5429
5430 return data_section;
5431 }
5432
5433 enum section_category
categorize_decl_for_section(tree decl,int reloc)5434 categorize_decl_for_section (tree decl, int reloc)
5435 {
5436 enum section_category ret;
5437
5438 if (TREE_CODE (decl) == FUNCTION_DECL)
5439 return SECCAT_TEXT;
5440 else if (TREE_CODE (decl) == STRING_CST)
5441 {
5442 if (flag_mudflap) /* or !flag_merge_constants */
5443 return SECCAT_RODATA;
5444 else
5445 return SECCAT_RODATA_MERGE_STR;
5446 }
5447 else if (TREE_CODE (decl) == VAR_DECL)
5448 {
5449 if (bss_initializer_p (decl))
5450 ret = SECCAT_BSS;
5451 else if (! TREE_READONLY (decl)
5452 || TREE_SIDE_EFFECTS (decl)
5453 || ! TREE_CONSTANT (DECL_INITIAL (decl)))
5454 {
5455 /* Here the reloc_rw_mask is not testing whether the section should
5456 be read-only or not, but whether the dynamic link will have to
5457 do something. If so, we wish to segregate the data in order to
5458 minimize cache misses inside the dynamic linker. */
5459 if (reloc & targetm.asm_out.reloc_rw_mask ())
5460 ret = reloc == 1 ? SECCAT_DATA_REL_LOCAL : SECCAT_DATA_REL;
5461 else
5462 ret = SECCAT_DATA;
5463 }
5464 else if (reloc & targetm.asm_out.reloc_rw_mask ())
5465 ret = reloc == 1 ? SECCAT_DATA_REL_RO_LOCAL : SECCAT_DATA_REL_RO;
5466 else if (reloc || flag_merge_constants < 2)
5467 /* C and C++ don't allow different variables to share the same
5468 location. -fmerge-all-constants allows even that (at the
5469 expense of not conforming). */
5470 ret = SECCAT_RODATA;
5471 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST)
5472 ret = SECCAT_RODATA_MERGE_STR_INIT;
5473 else
5474 ret = SECCAT_RODATA_MERGE_CONST;
5475 }
5476 else if (TREE_CODE (decl) == CONSTRUCTOR)
5477 {
5478 if ((reloc & targetm.asm_out.reloc_rw_mask ())
5479 || TREE_SIDE_EFFECTS (decl)
5480 || ! TREE_CONSTANT (decl))
5481 ret = SECCAT_DATA;
5482 else
5483 ret = SECCAT_RODATA;
5484 }
5485 else
5486 ret = SECCAT_RODATA;
5487
5488 /* There are no read-only thread-local sections. */
5489 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
5490 {
5491 /* Note that this would be *just* SECCAT_BSS, except that there's
5492 no concept of a read-only thread-local-data section. */
5493 if (ret == SECCAT_BSS
5494 || (flag_zero_initialized_in_bss
5495 && initializer_zerop (DECL_INITIAL (decl))))
5496 ret = SECCAT_TBSS;
5497 else
5498 ret = SECCAT_TDATA;
5499 }
5500
5501 /* If the target uses small data sections, select it. */
5502 else if (targetm.in_small_data_p (decl))
5503 {
5504 if (ret == SECCAT_BSS)
5505 ret = SECCAT_SBSS;
5506 else if (targetm.have_srodata_section && ret == SECCAT_RODATA)
5507 ret = SECCAT_SRODATA;
5508 else
5509 ret = SECCAT_SDATA;
5510 }
5511
5512 return ret;
5513 }
5514
5515 bool
decl_readonly_section(tree decl,int reloc)5516 decl_readonly_section (tree decl, int reloc)
5517 {
5518 switch (categorize_decl_for_section (decl, reloc))
5519 {
5520 case SECCAT_RODATA:
5521 case SECCAT_RODATA_MERGE_STR:
5522 case SECCAT_RODATA_MERGE_STR_INIT:
5523 case SECCAT_RODATA_MERGE_CONST:
5524 case SECCAT_SRODATA:
5525 return true;
5526 break;
5527 default:
5528 return false;
5529 break;
5530 }
5531 }
5532
5533 /* Select a section based on the above categorization. */
5534
5535 section *
default_elf_select_section(tree decl,int reloc,unsigned HOST_WIDE_INT align)5536 default_elf_select_section (tree decl, int reloc,
5537 unsigned HOST_WIDE_INT align)
5538 {
5539 const char *sname;
5540 switch (categorize_decl_for_section (decl, reloc))
5541 {
5542 case SECCAT_TEXT:
5543 /* We're not supposed to be called on FUNCTION_DECLs. */
5544 gcc_unreachable ();
5545 case SECCAT_RODATA:
5546 return readonly_data_section;
5547 case SECCAT_RODATA_MERGE_STR:
5548 return mergeable_string_section (decl, align, 0);
5549 case SECCAT_RODATA_MERGE_STR_INIT:
5550 return mergeable_string_section (DECL_INITIAL (decl), align, 0);
5551 case SECCAT_RODATA_MERGE_CONST:
5552 return mergeable_constant_section (DECL_MODE (decl), align, 0);
5553 case SECCAT_SRODATA:
5554 sname = ".sdata2";
5555 break;
5556 case SECCAT_DATA:
5557 return data_section;
5558 case SECCAT_DATA_REL:
5559 sname = ".data.rel";
5560 break;
5561 case SECCAT_DATA_REL_LOCAL:
5562 sname = ".data.rel.local";
5563 break;
5564 case SECCAT_DATA_REL_RO:
5565 sname = ".data.rel.ro";
5566 break;
5567 case SECCAT_DATA_REL_RO_LOCAL:
5568 sname = ".data.rel.ro.local";
5569 break;
5570 case SECCAT_SDATA:
5571 sname = ".sdata";
5572 break;
5573 case SECCAT_TDATA:
5574 sname = ".tdata";
5575 break;
5576 case SECCAT_BSS:
5577 if (bss_section)
5578 return bss_section;
5579 sname = ".bss";
5580 break;
5581 case SECCAT_SBSS:
5582 sname = ".sbss";
5583 break;
5584 case SECCAT_TBSS:
5585 sname = ".tbss";
5586 break;
5587 default:
5588 gcc_unreachable ();
5589 }
5590
5591 if (!DECL_P (decl))
5592 decl = NULL_TREE;
5593 return get_named_section (decl, sname, reloc);
5594 }
5595
5596 /* Construct a unique section name based on the decl name and the
5597 categorization performed above. */
5598
5599 void
default_unique_section(tree decl,int reloc)5600 default_unique_section (tree decl, int reloc)
5601 {
5602 /* We only need to use .gnu.linkonce if we don't have COMDAT groups. */
5603 bool one_only = DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP;
5604 const char *prefix, *name;
5605 size_t nlen, plen;
5606 char *string;
5607
5608 switch (categorize_decl_for_section (decl, reloc))
5609 {
5610 case SECCAT_TEXT:
5611 prefix = one_only ? ".gnu.linkonce.t." : ".text.";
5612 break;
5613 case SECCAT_RODATA:
5614 case SECCAT_RODATA_MERGE_STR:
5615 case SECCAT_RODATA_MERGE_STR_INIT:
5616 case SECCAT_RODATA_MERGE_CONST:
5617 prefix = one_only ? ".gnu.linkonce.r." : ".rodata.";
5618 break;
5619 case SECCAT_SRODATA:
5620 prefix = one_only ? ".gnu.linkonce.s2." : ".sdata2.";
5621 break;
5622 case SECCAT_DATA:
5623 prefix = one_only ? ".gnu.linkonce.d." : ".data.";
5624 break;
5625 case SECCAT_DATA_REL:
5626 prefix = one_only ? ".gnu.linkonce.d.rel." : ".data.rel.";
5627 break;
5628 case SECCAT_DATA_REL_LOCAL:
5629 prefix = one_only ? ".gnu.linkonce.d.rel.local." : ".data.rel.local.";
5630 break;
5631 case SECCAT_DATA_REL_RO:
5632 prefix = one_only ? ".gnu.linkonce.d.rel.ro." : ".data.rel.ro.";
5633 break;
5634 case SECCAT_DATA_REL_RO_LOCAL:
5635 prefix = one_only ? ".gnu.linkonce.d.rel.ro.local."
5636 : ".data.rel.ro.local.";
5637 break;
5638 case SECCAT_SDATA:
5639 prefix = one_only ? ".gnu.linkonce.s." : ".sdata.";
5640 break;
5641 case SECCAT_BSS:
5642 prefix = one_only ? ".gnu.linkonce.b." : ".bss.";
5643 break;
5644 case SECCAT_SBSS:
5645 prefix = one_only ? ".gnu.linkonce.sb." : ".sbss.";
5646 break;
5647 case SECCAT_TDATA:
5648 prefix = one_only ? ".gnu.linkonce.td." : ".tdata.";
5649 break;
5650 case SECCAT_TBSS:
5651 prefix = one_only ? ".gnu.linkonce.tb." : ".tbss.";
5652 break;
5653 default:
5654 gcc_unreachable ();
5655 }
5656 plen = strlen (prefix);
5657
5658 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5659 name = targetm.strip_name_encoding (name);
5660 nlen = strlen (name);
5661
5662 string = alloca (nlen + plen + 1);
5663 memcpy (string, prefix, plen);
5664 memcpy (string + plen, name, nlen + 1);
5665
5666 DECL_SECTION_NAME (decl) = build_string (nlen + plen, string);
5667 }
5668
5669 /* Like compute_reloc_for_constant, except for an RTX. The return value
5670 is a mask for which bit 1 indicates a global relocation, and bit 0
5671 indicates a local relocation. */
5672
5673 static int
compute_reloc_for_rtx_1(rtx * xp,void * data)5674 compute_reloc_for_rtx_1 (rtx *xp, void *data)
5675 {
5676 int *preloc = data;
5677 rtx x = *xp;
5678
5679 switch (GET_CODE (x))
5680 {
5681 case SYMBOL_REF:
5682 *preloc |= SYMBOL_REF_LOCAL_P (x) ? 1 : 2;
5683 break;
5684 case LABEL_REF:
5685 *preloc |= 1;
5686 break;
5687 default:
5688 break;
5689 }
5690
5691 return 0;
5692 }
5693
5694 static int
compute_reloc_for_rtx(rtx x)5695 compute_reloc_for_rtx (rtx x)
5696 {
5697 int reloc;
5698
5699 switch (GET_CODE (x))
5700 {
5701 case CONST:
5702 case SYMBOL_REF:
5703 case LABEL_REF:
5704 reloc = 0;
5705 for_each_rtx (&x, compute_reloc_for_rtx_1, &reloc);
5706 return reloc;
5707
5708 default:
5709 return 0;
5710 }
5711 }
5712
5713 section *
default_select_rtx_section(enum machine_mode mode ATTRIBUTE_UNUSED,rtx x,unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)5714 default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED,
5715 rtx x,
5716 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
5717 {
5718 if (compute_reloc_for_rtx (x) & targetm.asm_out.reloc_rw_mask ())
5719 return data_section;
5720 else
5721 return readonly_data_section;
5722 }
5723
5724 section *
default_elf_select_rtx_section(enum machine_mode mode,rtx x,unsigned HOST_WIDE_INT align)5725 default_elf_select_rtx_section (enum machine_mode mode, rtx x,
5726 unsigned HOST_WIDE_INT align)
5727 {
5728 int reloc = compute_reloc_for_rtx (x);
5729
5730 /* ??? Handle small data here somehow. */
5731
5732 if (reloc & targetm.asm_out.reloc_rw_mask ())
5733 {
5734 if (reloc == 1)
5735 return get_named_section (NULL, ".data.rel.ro.local", 1);
5736 else
5737 return get_named_section (NULL, ".data.rel.ro", 3);
5738 }
5739
5740 return mergeable_constant_section (mode, align, 0);
5741 }
5742
5743 /* Set the generally applicable flags on the SYMBOL_REF for EXP. */
5744
5745 void
default_encode_section_info(tree decl,rtx rtl,int first ATTRIBUTE_UNUSED)5746 default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
5747 {
5748 rtx symbol;
5749 int flags;
5750
5751 /* Careful not to prod global register variables. */
5752 if (!MEM_P (rtl))
5753 return;
5754 symbol = XEXP (rtl, 0);
5755 if (GET_CODE (symbol) != SYMBOL_REF)
5756 return;
5757
5758 flags = SYMBOL_REF_FLAGS (symbol) & SYMBOL_FLAG_HAS_BLOCK_INFO;
5759 if (TREE_CODE (decl) == FUNCTION_DECL)
5760 flags |= SYMBOL_FLAG_FUNCTION;
5761 if (targetm.binds_local_p (decl))
5762 flags |= SYMBOL_FLAG_LOCAL;
5763 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
5764 flags |= DECL_TLS_MODEL (decl) << SYMBOL_FLAG_TLS_SHIFT;
5765 else if (targetm.in_small_data_p (decl))
5766 flags |= SYMBOL_FLAG_SMALL;
5767 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without
5768 being PUBLIC, the thing *must* be defined in this translation unit.
5769 Prevent this buglet from being propagated into rtl code as well. */
5770 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
5771 flags |= SYMBOL_FLAG_EXTERNAL;
5772
5773 SYMBOL_REF_FLAGS (symbol) = flags;
5774 }
5775
5776 /* By default, we do nothing for encode_section_info, so we need not
5777 do anything but discard the '*' marker. */
5778
5779 const char *
default_strip_name_encoding(const char * str)5780 default_strip_name_encoding (const char *str)
5781 {
5782 return str + (*str == '*');
5783 }
5784
5785 #ifdef ASM_OUTPUT_DEF
5786 /* The default implementation of TARGET_ASM_OUTPUT_ANCHOR. Define the
5787 anchor relative to ".", the current section position. */
5788
5789 void
default_asm_output_anchor(rtx symbol)5790 default_asm_output_anchor (rtx symbol)
5791 {
5792 char buffer[100];
5793
5794 sprintf (buffer, ". + " HOST_WIDE_INT_PRINT_DEC,
5795 SYMBOL_REF_BLOCK_OFFSET (symbol));
5796 ASM_OUTPUT_DEF (asm_out_file, XSTR (symbol, 0), buffer);
5797 }
5798 #endif
5799
5800 /* The default implementation of TARGET_USE_ANCHORS_FOR_SYMBOL_P. */
5801
5802 bool
default_use_anchors_for_symbol_p(rtx symbol)5803 default_use_anchors_for_symbol_p (rtx symbol)
5804 {
5805 section *sect;
5806 tree decl;
5807
5808 /* Don't use anchors for mergeable sections. The linker might move
5809 the objects around. */
5810 sect = SYMBOL_REF_BLOCK (symbol)->sect;
5811 if (sect->common.flags & SECTION_MERGE)
5812 return false;
5813
5814 /* Don't use anchors for small data sections. The small data register
5815 acts as an anchor for such sections. */
5816 if (sect->common.flags & SECTION_SMALL)
5817 return false;
5818
5819 decl = SYMBOL_REF_DECL (symbol);
5820 if (decl && DECL_P (decl))
5821 {
5822 /* Don't use section anchors for decls that might be defined by
5823 other modules. */
5824 if (!targetm.binds_local_p (decl))
5825 return false;
5826
5827 /* Don't use section anchors for decls that will be placed in a
5828 small data section. */
5829 /* ??? Ideally, this check would be redundant with the SECTION_SMALL
5830 one above. The problem is that we only use SECTION_SMALL for
5831 sections that should be marked as small in the section directive. */
5832 if (targetm.in_small_data_p (decl))
5833 return false;
5834 }
5835 return true;
5836 }
5837
5838 /* Assume ELF-ish defaults, since that's pretty much the most liberal
5839 wrt cross-module name binding. */
5840
5841 bool
default_binds_local_p(tree exp)5842 default_binds_local_p (tree exp)
5843 {
5844 return default_binds_local_p_1 (exp, flag_shlib);
5845 }
5846
5847 bool
default_binds_local_p_1(tree exp,int shlib)5848 default_binds_local_p_1 (tree exp, int shlib)
5849 {
5850 bool local_p;
5851
5852 /* A non-decl is an entry in the constant pool. */
5853 if (!DECL_P (exp))
5854 local_p = true;
5855 /* Weakrefs may not bind locally, even though the weakref itself is
5856 always static and therefore local. */
5857 else if (lookup_attribute ("weakref", DECL_ATTRIBUTES (exp)))
5858 local_p = false;
5859 /* Static variables are always local. */
5860 else if (! TREE_PUBLIC (exp))
5861 local_p = true;
5862 /* A variable is local if the user has said explicitly that it will
5863 be. */
5864 else if (DECL_VISIBILITY_SPECIFIED (exp)
5865 && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
5866 local_p = true;
5867 /* Variables defined outside this object might not be local. */
5868 else if (DECL_EXTERNAL (exp))
5869 local_p = false;
5870 /* If defined in this object and visibility is not default, must be
5871 local. */
5872 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
5873 local_p = true;
5874 /* Default visibility weak data can be overridden by a strong symbol
5875 in another module and so are not local. */
5876 else if (DECL_WEAK (exp))
5877 local_p = false;
5878 /* If PIC, then assume that any global name can be overridden by
5879 symbols resolved from other modules. */
5880 else if (shlib)
5881 local_p = false;
5882 /* Uninitialized COMMON variable may be unified with symbols
5883 resolved from other modules. */
5884 else if (DECL_COMMON (exp)
5885 && (DECL_INITIAL (exp) == NULL
5886 || DECL_INITIAL (exp) == error_mark_node))
5887 local_p = false;
5888 /* Otherwise we're left with initialized (or non-common) global data
5889 which is of necessity defined locally. */
5890 else
5891 local_p = true;
5892
5893 return local_p;
5894 }
5895
5896 /* Determine whether or not a pointer mode is valid. Assume defaults
5897 of ptr_mode or Pmode - can be overridden. */
5898 bool
default_valid_pointer_mode(enum machine_mode mode)5899 default_valid_pointer_mode (enum machine_mode mode)
5900 {
5901 return (mode == ptr_mode || mode == Pmode);
5902 }
5903
5904 /* Default function to output code that will globalize a label. A
5905 target must define GLOBAL_ASM_OP or provide its own function to
5906 globalize a label. */
5907 #ifdef GLOBAL_ASM_OP
5908 void
default_globalize_label(FILE * stream,const char * name)5909 default_globalize_label (FILE * stream, const char *name)
5910 {
5911 fputs (GLOBAL_ASM_OP, stream);
5912 assemble_name (stream, name);
5913 putc ('\n', stream);
5914 }
5915 #endif /* GLOBAL_ASM_OP */
5916
5917 /* Default function to output a label for unwind information. The
5918 default is to do nothing. A target that needs nonlocal labels for
5919 unwind information must provide its own function to do this. */
5920 void
default_emit_unwind_label(FILE * stream ATTRIBUTE_UNUSED,tree decl ATTRIBUTE_UNUSED,int for_eh ATTRIBUTE_UNUSED,int empty ATTRIBUTE_UNUSED)5921 default_emit_unwind_label (FILE * stream ATTRIBUTE_UNUSED,
5922 tree decl ATTRIBUTE_UNUSED,
5923 int for_eh ATTRIBUTE_UNUSED,
5924 int empty ATTRIBUTE_UNUSED)
5925 {
5926 }
5927
5928 /* Default function to output a label to divide up the exception table.
5929 The default is to do nothing. A target that needs/wants to divide
5930 up the table must provide it's own function to do this. */
5931 void
default_emit_except_table_label(FILE * stream ATTRIBUTE_UNUSED)5932 default_emit_except_table_label (FILE * stream ATTRIBUTE_UNUSED)
5933 {
5934 }
5935
5936 /* This is how to output an internal numbered label where PREFIX is
5937 the class of label and LABELNO is the number within the class. */
5938
5939 void
default_internal_label(FILE * stream,const char * prefix,unsigned long labelno)5940 default_internal_label (FILE *stream, const char *prefix,
5941 unsigned long labelno)
5942 {
5943 char *const buf = alloca (40 + strlen (prefix));
5944 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
5945 ASM_OUTPUT_INTERNAL_LABEL (stream, buf);
5946 }
5947
5948 /* This is the default behavior at the beginning of a file. It's
5949 controlled by two other target-hook toggles. */
5950 void
default_file_start(void)5951 default_file_start (void)
5952 {
5953 if (targetm.file_start_app_off && !flag_verbose_asm)
5954 fputs (ASM_APP_OFF, asm_out_file);
5955
5956 if (targetm.file_start_file_directive)
5957 output_file_directive (asm_out_file, main_input_filename);
5958 }
5959
5960 /* This is a generic routine suitable for use as TARGET_ASM_FILE_END
5961 which emits a special section directive used to indicate whether or
5962 not this object file needs an executable stack. This is primarily
5963 a GNU extension to ELF but could be used on other targets. */
5964
5965 int trampolines_created;
5966
5967 void
file_end_indicate_exec_stack(void)5968 file_end_indicate_exec_stack (void)
5969 {
5970 unsigned int flags = SECTION_DEBUG;
5971 if (trampolines_created)
5972 flags |= SECTION_CODE;
5973
5974 switch_to_section (get_section (".note.GNU-stack", flags, NULL));
5975 }
5976
5977 /* Output DIRECTIVE (a C string) followed by a newline. This is used as
5978 a get_unnamed_section callback. */
5979
5980 void
output_section_asm_op(const void * directive)5981 output_section_asm_op (const void *directive)
5982 {
5983 fprintf (asm_out_file, "%s\n", (const char *) directive);
5984 }
5985
5986 /* Emit assembly code to switch to section NEW_SECTION. Do nothing if
5987 the current section is NEW_SECTION. */
5988
5989 void
switch_to_section(section * new_section)5990 switch_to_section (section *new_section)
5991 {
5992 if (in_section == new_section)
5993 return;
5994
5995 if (new_section->common.flags & SECTION_FORGET)
5996 in_section = NULL;
5997 else
5998 in_section = new_section;
5999
6000 switch (SECTION_STYLE (new_section))
6001 {
6002 case SECTION_NAMED:
6003 if (cfun
6004 && !cfun->unlikely_text_section_name
6005 && strcmp (new_section->named.name,
6006 UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
6007 cfun->unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
6008
6009 targetm.asm_out.named_section (new_section->named.name,
6010 new_section->named.common.flags,
6011 new_section->named.decl);
6012 break;
6013
6014 case SECTION_UNNAMED:
6015 new_section->unnamed.callback (new_section->unnamed.data);
6016 break;
6017
6018 case SECTION_NOSWITCH:
6019 gcc_unreachable ();
6020 break;
6021 }
6022
6023 new_section->common.flags |= SECTION_DECLARED;
6024 }
6025
6026 /* If block symbol SYMBOL has not yet been assigned an offset, place
6027 it at the end of its block. */
6028
6029 void
place_block_symbol(rtx symbol)6030 place_block_symbol (rtx symbol)
6031 {
6032 unsigned HOST_WIDE_INT size, mask, offset;
6033 struct constant_descriptor_rtx *desc;
6034 unsigned int alignment;
6035 struct object_block *block;
6036 tree decl;
6037
6038 gcc_assert (SYMBOL_REF_BLOCK (symbol));
6039 if (SYMBOL_REF_BLOCK_OFFSET (symbol) >= 0)
6040 return;
6041
6042 /* Work out the symbol's size and alignment. */
6043 if (CONSTANT_POOL_ADDRESS_P (symbol))
6044 {
6045 desc = SYMBOL_REF_CONSTANT (symbol);
6046 alignment = desc->align;
6047 size = GET_MODE_SIZE (desc->mode);
6048 }
6049 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6050 {
6051 decl = SYMBOL_REF_DECL (symbol);
6052 alignment = get_constant_alignment (decl);
6053 size = get_constant_size (decl);
6054 }
6055 else
6056 {
6057 decl = SYMBOL_REF_DECL (symbol);
6058 alignment = DECL_ALIGN (decl);
6059 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6060 }
6061
6062 /* Calculate the object's offset from the start of the block. */
6063 block = SYMBOL_REF_BLOCK (symbol);
6064 mask = alignment / BITS_PER_UNIT - 1;
6065 offset = (block->size + mask) & ~mask;
6066 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
6067
6068 /* Record the block's new alignment and size. */
6069 block->alignment = MAX (block->alignment, alignment);
6070 block->size = offset + size;
6071
6072 VEC_safe_push (rtx, gc, block->objects, symbol);
6073 }
6074
6075 /* Return the anchor that should be used to address byte offset OFFSET
6076 from the first object in BLOCK. MODEL is the TLS model used
6077 to access it. */
6078
6079 rtx
get_section_anchor(struct object_block * block,HOST_WIDE_INT offset,enum tls_model model)6080 get_section_anchor (struct object_block *block, HOST_WIDE_INT offset,
6081 enum tls_model model)
6082 {
6083 char label[100];
6084 unsigned int begin, middle, end;
6085 unsigned HOST_WIDE_INT min_offset, max_offset, range, bias, delta;
6086 rtx anchor;
6087
6088 /* Work out the anchor's offset. Use an offset of 0 for the first
6089 anchor so that we don't pessimize the case where we take the address
6090 of a variable at the beginning of the block. This is particularly
6091 useful when a block has only one variable assigned to it.
6092
6093 We try to place anchors RANGE bytes apart, so there can then be
6094 anchors at +/-RANGE, +/-2 * RANGE, and so on, up to the limits of
6095 a ptr_mode offset. With some target settings, the lowest such
6096 anchor might be out of range for the lowest ptr_mode offset;
6097 likewise the highest anchor for the highest offset. Use anchors
6098 at the extreme ends of the ptr_mode range in such cases.
6099
6100 All arithmetic uses unsigned integers in order to avoid
6101 signed overflow. */
6102 max_offset = (unsigned HOST_WIDE_INT) targetm.max_anchor_offset;
6103 min_offset = (unsigned HOST_WIDE_INT) targetm.min_anchor_offset;
6104 range = max_offset - min_offset + 1;
6105 if (range == 0)
6106 offset = 0;
6107 else
6108 {
6109 bias = 1 << (GET_MODE_BITSIZE (ptr_mode) - 1);
6110 if (offset < 0)
6111 {
6112 delta = -(unsigned HOST_WIDE_INT) offset + max_offset;
6113 delta -= delta % range;
6114 if (delta > bias)
6115 delta = bias;
6116 offset = (HOST_WIDE_INT) (-delta);
6117 }
6118 else
6119 {
6120 delta = (unsigned HOST_WIDE_INT) offset - min_offset;
6121 delta -= delta % range;
6122 if (delta > bias - 1)
6123 delta = bias - 1;
6124 offset = (HOST_WIDE_INT) delta;
6125 }
6126 }
6127
6128 /* Do a binary search to see if there's already an anchor we can use.
6129 Set BEGIN to the new anchor's index if not. */
6130 begin = 0;
6131 end = VEC_length (rtx, block->anchors);
6132 while (begin != end)
6133 {
6134 middle = (end + begin) / 2;
6135 anchor = VEC_index (rtx, block->anchors, middle);
6136 if (SYMBOL_REF_BLOCK_OFFSET (anchor) > offset)
6137 end = middle;
6138 else if (SYMBOL_REF_BLOCK_OFFSET (anchor) < offset)
6139 begin = middle + 1;
6140 else if (SYMBOL_REF_TLS_MODEL (anchor) > model)
6141 end = middle;
6142 else if (SYMBOL_REF_TLS_MODEL (anchor) < model)
6143 begin = middle + 1;
6144 else
6145 return anchor;
6146 }
6147
6148 /* Create a new anchor with a unique label. */
6149 ASM_GENERATE_INTERNAL_LABEL (label, "LANCHOR", anchor_labelno++);
6150 anchor = create_block_symbol (ggc_strdup (label), block, offset);
6151 SYMBOL_REF_FLAGS (anchor) |= SYMBOL_FLAG_LOCAL | SYMBOL_FLAG_ANCHOR;
6152 SYMBOL_REF_FLAGS (anchor) |= model << SYMBOL_FLAG_TLS_SHIFT;
6153
6154 /* Insert it at index BEGIN. */
6155 VEC_safe_insert (rtx, gc, block->anchors, begin, anchor);
6156 return anchor;
6157 }
6158
6159 /* Output the objects in BLOCK. */
6160
6161 static void
output_object_block(struct object_block * block)6162 output_object_block (struct object_block *block)
6163 {
6164 struct constant_descriptor_rtx *desc;
6165 unsigned int i;
6166 HOST_WIDE_INT offset;
6167 tree decl;
6168 rtx symbol;
6169
6170 if (block->objects == NULL)
6171 return;
6172
6173 /* Switch to the section and make sure that the first byte is
6174 suitably aligned. */
6175 switch_to_section (block->sect);
6176 assemble_align (block->alignment);
6177
6178 /* Define the values of all anchors relative to the current section
6179 position. */
6180 for (i = 0; VEC_iterate (rtx, block->anchors, i, symbol); i++)
6181 targetm.asm_out.output_anchor (symbol);
6182
6183 /* Output the objects themselves. */
6184 offset = 0;
6185 for (i = 0; VEC_iterate (rtx, block->objects, i, symbol); i++)
6186 {
6187 /* Move to the object's offset, padding with zeros if necessary. */
6188 assemble_zeros (SYMBOL_REF_BLOCK_OFFSET (symbol) - offset);
6189 offset = SYMBOL_REF_BLOCK_OFFSET (symbol);
6190 if (CONSTANT_POOL_ADDRESS_P (symbol))
6191 {
6192 desc = SYMBOL_REF_CONSTANT (symbol);
6193 output_constant_pool_1 (desc, 1);
6194 offset += GET_MODE_SIZE (desc->mode);
6195 }
6196 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6197 {
6198 decl = SYMBOL_REF_DECL (symbol);
6199 assemble_constant_contents (decl, XSTR (symbol, 0),
6200 get_constant_alignment (decl));
6201 offset += get_constant_size (decl);
6202 }
6203 else
6204 {
6205 decl = SYMBOL_REF_DECL (symbol);
6206 assemble_variable_contents (decl, XSTR (symbol, 0), false);
6207 offset += tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6208 }
6209 }
6210 }
6211
6212 /* A htab_traverse callback used to call output_object_block for
6213 each member of object_block_htab. */
6214
6215 static int
output_object_block_htab(void ** slot,void * data ATTRIBUTE_UNUSED)6216 output_object_block_htab (void **slot, void *data ATTRIBUTE_UNUSED)
6217 {
6218 output_object_block ((struct object_block *) (*slot));
6219 return 1;
6220 }
6221
6222 /* Output the definitions of all object_blocks. */
6223
6224 void
output_object_blocks(void)6225 output_object_blocks (void)
6226 {
6227 htab_traverse (object_block_htab, output_object_block_htab, NULL);
6228 }
6229
6230 /* Emit text to declare externally defined symbols. It is needed to
6231 properly support non-default visibility. */
6232 void
default_elf_asm_output_external(FILE * file ATTRIBUTE_UNUSED,tree decl,const char * name ATTRIBUTE_UNUSED)6233 default_elf_asm_output_external (FILE *file ATTRIBUTE_UNUSED,
6234 tree decl,
6235 const char *name ATTRIBUTE_UNUSED)
6236 {
6237 /* We output the name if and only if TREE_SYMBOL_REFERENCED is
6238 set in order to avoid putting out names that are never really
6239 used. */
6240 if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))
6241 && targetm.binds_local_p (decl))
6242 maybe_assemble_visibility (decl);
6243 }
6244
6245 #include "gt-varasm.h"
6246