varasm.c revision 258748
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 6This file is part of GCC. 7 8GCC is free software; you can redistribute it and/or modify it under 9the terms of the GNU General Public License as published by the Free 10Software Foundation; either version 2, or (at your option) any later 11version. 12 13GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14WARRANTY; without even the implied warranty of MERCHANTABILITY or 15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16for more details. 17 18You should have received a copy of the GNU General Public License 19along with GCC; see the file COPYING. If not, write to the Free 20Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 2102110-1301, 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. */ 63extern GTY(()) const char *first_global_object_name; 64extern GTY(()) const char *weak_global_object_name; 65 66const char *first_global_object_name; 67const char *weak_global_object_name; 68 69struct addr_const; 70struct constant_descriptor_rtx; 71struct rtx_constant_pool; 72 73struct 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 88static GTY(()) int const_labelno; 89 90/* Carry information from ASM_DECLARE_OBJECT_NAME 91 to ASM_FINISH_DECLARE_OBJECT. */ 92 93int 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 100tree 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 105bool 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 110static HOST_WIDE_INT const_alias_set; 111 112static const char *strip_reg_name (const char *); 113static int contains_pointers_p (tree); 114#ifdef ASM_OUTPUT_EXTERNAL 115static bool incorporeal_function_p (tree); 116#endif 117static void decode_addr_const (tree, struct addr_const *); 118static hashval_t const_desc_hash (const void *); 119static int const_desc_eq (const void *, const void *); 120static hashval_t const_hash_1 (const tree); 121static int compare_constant (const tree, const tree); 122static tree copy_constant (tree); 123static void output_constant_def_contents (rtx); 124static void output_addressed_constants (tree); 125static unsigned HOST_WIDE_INT array_size_for_constructor (tree); 126static unsigned min_align (unsigned, unsigned); 127static void output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int); 128static void globalize_decl (tree); 129#ifdef BSS_SECTION_ASM_OP 130#ifdef ASM_OUTPUT_BSS 131static 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 135static 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 */ 140static void mark_weak (tree); 141static void output_constant_pool (const char *, tree); 142 143/* Well-known sections, each one associated with some sort of *_ASM_OP. */ 144section *text_section; 145section *data_section; 146section *readonly_data_section; 147section *sdata_section; 148section *ctors_section; 149section *dtors_section; 150section *bss_section; 151section *sbss_section; 152 153/* Various forms of common section. All are guaranteed to be nonnull. */ 154section *tls_comm_section; 155section *comm_section; 156section *lcomm_section; 157 158/* A SECTION_NOSWITCH section used for declaring global BSS variables. 159 May be null. */ 160section *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. */ 165section *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. */ 170section *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. */ 174section *in_section; 175 176/* True if code for the current function is currently being directed 177 at the cold section. */ 178bool in_cold_section_p; 179 180/* A linked list of all the unnamed sections. */ 181static 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. */ 191static GTY((param_is (section))) htab_t section_htab; 192 193/* A table of object_blocks, indexed by section. */ 194static GTY((param_is (struct object_block))) htab_t object_block_htab; 195 196/* The next number to use for internal anchor labels. */ 197static GTY(()) int anchor_labelno; 198 199/* A pool of constants that can be shared between functions. */ 200static GTY(()) struct rtx_constant_pool *shared_constant_pool; 201 202/* Helper routines for maintaining section_htab. */ 203 204static int 205section_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 213static hashval_t 214section_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 222static hashval_t 223hash_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 232static int 233object_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 241static hashval_t 242object_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 250section * 251get_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 268static section * 269get_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 283section * 284get_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 319static bool 320use_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 329static struct object_block * 330get_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 355static rtx 356create_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 380static void 381initialize_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 408section * 409unlikely_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 427bool 428unlikely_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 450section * 451get_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 466void 467resolve_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 486static void 487asm_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 513static void 514asm_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 538static section * 539hot_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 555section * 556function_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 575section * 576current_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 597section * 598default_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 644section * 645default_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 652static section * 653mergeable_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 708section * 709mergeable_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 734static const char * 735strip_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. */ 749void 750set_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 767int 768decode_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 821static bool 822bss_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 836void 837align_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 879static section * 880get_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 920static struct object_block * 921get_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 957static void 958change_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 969static bool 970use_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 999void 1000make_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 1172void 1173assemble_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 1187void 1188default_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 1202void 1203default_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 1225void 1226default_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 1237void 1238default_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 1252void 1253default_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 1275void 1276default_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 1299void 1300notice_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 1339void 1340assemble_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 (DECL_ALIGN (decl)); 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 (DECL_ALIGN (decl)); 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 (DECL_ALIGN (decl) / BITS_PER_UNIT); 1428 if (align > 0) 1429 { 1430 ASM_OUTPUT_ALIGN (asm_out_file, align); 1431 } 1432 1433 /* Handle a user-specified function alignment. 1434 Note that we still need to align to DECL_ALIGN, as above, 1435 because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */ 1436 if (! DECL_USER_ALIGN (decl) 1437 && align_functions_log > align 1438 && cfun->function_frequency != FUNCTION_FREQUENCY_UNLIKELY_EXECUTED) 1439 { 1440#ifdef ASM_OUTPUT_MAX_SKIP_ALIGN 1441 ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file, 1442 align_functions_log, align_functions - 1); 1443#else 1444 ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log); 1445#endif 1446 } 1447 1448#ifdef ASM_OUTPUT_FUNCTION_PREFIX 1449 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname); 1450#endif 1451 1452 (*debug_hooks->begin_function) (decl); 1453 1454 /* Make function name accessible from other files, if appropriate. */ 1455 1456 if (TREE_PUBLIC (decl)) 1457 { 1458 notice_global_symbol (decl); 1459 1460 globalize_decl (decl); 1461 1462 maybe_assemble_visibility (decl); 1463 } 1464 1465 if (DECL_PRESERVE_P (decl)) 1466 targetm.asm_out.mark_decl_preserved (fnname); 1467 1468 /* Do any machine/system dependent processing of the function name. */ 1469#ifdef ASM_DECLARE_FUNCTION_NAME 1470 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl); 1471#else 1472 /* Standard thing is just output label for the function. */ 1473 ASM_OUTPUT_LABEL (asm_out_file, fnname); 1474#endif /* ASM_DECLARE_FUNCTION_NAME */ 1475} 1476 1477/* Output assembler code associated with defining the size of the 1478 function. DECL describes the function. NAME is the function's name. */ 1479 1480void 1481assemble_end_function (tree decl, const char *fnname ATTRIBUTE_UNUSED) 1482{ 1483#ifdef ASM_DECLARE_FUNCTION_SIZE 1484 /* We could have switched section in the middle of the function. */ 1485 if (flag_reorder_blocks_and_partition) 1486 switch_to_section (function_section (decl)); 1487 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl); 1488#endif 1489 if (! CONSTANT_POOL_BEFORE_FUNCTION) 1490 { 1491 output_constant_pool (fnname, decl); 1492 switch_to_section (function_section (decl)); /* need to switch back */ 1493 } 1494 /* Output labels for end of hot/cold text sections (to be used by 1495 debug info.) */ 1496 if (flag_reorder_blocks_and_partition) 1497 { 1498 section *save_text_section; 1499 1500 save_text_section = in_section; 1501 switch_to_section (unlikely_text_section ()); 1502 ASM_OUTPUT_LABEL (asm_out_file, cfun->cold_section_end_label); 1503 if (first_function_block_is_cold) 1504 switch_to_section (text_section); 1505 else 1506 switch_to_section (function_section (decl)); 1507 ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_end_label); 1508 switch_to_section (save_text_section); 1509 } 1510} 1511 1512/* Assemble code to leave SIZE bytes of zeros. */ 1513 1514void 1515assemble_zeros (unsigned HOST_WIDE_INT size) 1516{ 1517 /* Do no output if -fsyntax-only. */ 1518 if (flag_syntax_only) 1519 return; 1520 1521#ifdef ASM_NO_SKIP_IN_TEXT 1522 /* The `space' pseudo in the text section outputs nop insns rather than 0s, 1523 so we must output 0s explicitly in the text section. */ 1524 if (ASM_NO_SKIP_IN_TEXT && (in_section->common.flags & SECTION_CODE) != 0) 1525 { 1526 unsigned HOST_WIDE_INT i; 1527 for (i = 0; i < size; i++) 1528 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1); 1529 } 1530 else 1531#endif 1532 if (size > 0) 1533 ASM_OUTPUT_SKIP (asm_out_file, size); 1534} 1535 1536/* Assemble an alignment pseudo op for an ALIGN-bit boundary. */ 1537 1538void 1539assemble_align (int align) 1540{ 1541 if (align > BITS_PER_UNIT) 1542 { 1543 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT)); 1544 } 1545} 1546 1547/* Assemble a string constant with the specified C string as contents. */ 1548 1549void 1550assemble_string (const char *p, int size) 1551{ 1552 int pos = 0; 1553 int maximum = 2000; 1554 1555 /* If the string is very long, split it up. */ 1556 1557 while (pos < size) 1558 { 1559 int thissize = size - pos; 1560 if (thissize > maximum) 1561 thissize = maximum; 1562 1563 ASM_OUTPUT_ASCII (asm_out_file, p, thissize); 1564 1565 pos += thissize; 1566 p += thissize; 1567 } 1568} 1569 1570 1571/* A noswitch_section_callback for lcomm_section. */ 1572 1573static bool 1574emit_local (tree decl ATTRIBUTE_UNUSED, 1575 const char *name ATTRIBUTE_UNUSED, 1576 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED, 1577 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED) 1578{ 1579#if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL 1580 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name, 1581 size, DECL_ALIGN (decl)); 1582 return true; 1583#elif defined ASM_OUTPUT_ALIGNED_LOCAL 1584 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl)); 1585 return true; 1586#else 1587 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded); 1588 return false; 1589#endif 1590} 1591 1592/* A noswitch_section_callback for bss_noswitch_section. */ 1593 1594#if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS 1595static bool 1596emit_bss (tree decl ATTRIBUTE_UNUSED, 1597 const char *name ATTRIBUTE_UNUSED, 1598 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED, 1599 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED) 1600{ 1601#if defined ASM_OUTPUT_ALIGNED_BSS 1602 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl)); 1603 return true; 1604#else 1605 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded); 1606 return false; 1607#endif 1608} 1609#endif 1610 1611/* A noswitch_section_callback for comm_section. */ 1612 1613static bool 1614emit_common (tree decl ATTRIBUTE_UNUSED, 1615 const char *name ATTRIBUTE_UNUSED, 1616 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED, 1617 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED) 1618{ 1619#if defined ASM_OUTPUT_ALIGNED_DECL_COMMON 1620 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name, 1621 size, DECL_ALIGN (decl)); 1622 return true; 1623#elif defined ASM_OUTPUT_ALIGNED_COMMON 1624 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl)); 1625 return true; 1626#else 1627 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded); 1628 return false; 1629#endif 1630} 1631 1632/* A noswitch_section_callback for tls_comm_section. */ 1633 1634static bool 1635emit_tls_common (tree decl ATTRIBUTE_UNUSED, 1636 const char *name ATTRIBUTE_UNUSED, 1637 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED, 1638 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED) 1639{ 1640#ifdef ASM_OUTPUT_TLS_COMMON 1641 ASM_OUTPUT_TLS_COMMON (asm_out_file, decl, name, size); 1642 return true; 1643#else 1644 sorry ("thread-local COMMON data not implemented"); 1645 return true; 1646#endif 1647} 1648 1649/* Assemble DECL given that it belongs in SECTION_NOSWITCH section SECT. 1650 NAME is the name of DECL's SYMBOL_REF. */ 1651 1652static void 1653assemble_noswitch_variable (tree decl, const char *name, section *sect) 1654{ 1655 unsigned HOST_WIDE_INT size, rounded; 1656 1657 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1); 1658 rounded = size; 1659 1660 /* Don't allocate zero bytes of common, 1661 since that means "undefined external" in the linker. */ 1662 if (size == 0) 1663 rounded = 1; 1664 1665 /* Round size up to multiple of BIGGEST_ALIGNMENT bits 1666 so that each uninitialized object starts on such a boundary. */ 1667 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1; 1668 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT) 1669 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT)); 1670 1671 if (!sect->noswitch.callback (decl, name, size, rounded) 1672 && (unsigned HOST_WIDE_INT) DECL_ALIGN_UNIT (decl) > rounded) 1673 warning (0, "requested alignment for %q+D is greater than " 1674 "implemented alignment of %wu", decl, rounded); 1675} 1676 1677/* A subroutine of assemble_variable. Output the label and contents of 1678 DECL, whose address is a SYMBOL_REF with name NAME. DONT_OUTPUT_DATA 1679 is as for assemble_variable. */ 1680 1681static void 1682assemble_variable_contents (tree decl, const char *name, 1683 bool dont_output_data) 1684{ 1685 /* Do any machine/system dependent processing of the object. */ 1686#ifdef ASM_DECLARE_OBJECT_NAME 1687 last_assemble_variable_decl = decl; 1688 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl); 1689#else 1690 /* Standard thing is just output label for the object. */ 1691 ASM_OUTPUT_LABEL (asm_out_file, name); 1692#endif /* ASM_DECLARE_OBJECT_NAME */ 1693 1694 if (!dont_output_data) 1695 { 1696 if (DECL_INITIAL (decl) 1697 && DECL_INITIAL (decl) != error_mark_node 1698 && !initializer_zerop (DECL_INITIAL (decl))) 1699 /* Output the actual data. */ 1700 output_constant (DECL_INITIAL (decl), 1701 tree_low_cst (DECL_SIZE_UNIT (decl), 1), 1702 DECL_ALIGN (decl)); 1703 else 1704 /* Leave space for it. */ 1705 assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1)); 1706 } 1707} 1708 1709/* Assemble everything that is needed for a variable or function declaration. 1710 Not used for automatic variables, and not used for function definitions. 1711 Should not be called for variables of incomplete structure type. 1712 1713 TOP_LEVEL is nonzero if this variable has file scope. 1714 AT_END is nonzero if this is the special handling, at end of compilation, 1715 to define things that have had only tentative definitions. 1716 DONT_OUTPUT_DATA if nonzero means don't actually output the 1717 initial value (that will be done by the caller). */ 1718 1719void 1720assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED, 1721 int at_end ATTRIBUTE_UNUSED, int dont_output_data) 1722{ 1723 const char *name; 1724 rtx decl_rtl, symbol; 1725 section *sect; 1726 1727 if (lang_hooks.decls.prepare_assemble_variable) 1728 lang_hooks.decls.prepare_assemble_variable (decl); 1729 1730 last_assemble_variable_decl = 0; 1731 1732 /* Normally no need to say anything here for external references, 1733 since assemble_external is called by the language-specific code 1734 when a declaration is first seen. */ 1735 1736 if (DECL_EXTERNAL (decl)) 1737 return; 1738 1739 /* Output no assembler code for a function declaration. 1740 Only definitions of functions output anything. */ 1741 1742 if (TREE_CODE (decl) == FUNCTION_DECL) 1743 return; 1744 1745 /* Do nothing for global register variables. */ 1746 if (DECL_RTL_SET_P (decl) && REG_P (DECL_RTL (decl))) 1747 { 1748 TREE_ASM_WRITTEN (decl) = 1; 1749 return; 1750 } 1751 1752 /* If type was incomplete when the variable was declared, 1753 see if it is complete now. */ 1754 1755 if (DECL_SIZE (decl) == 0) 1756 layout_decl (decl, 0); 1757 1758 /* Still incomplete => don't allocate it; treat the tentative defn 1759 (which is what it must have been) as an `extern' reference. */ 1760 1761 if (!dont_output_data && DECL_SIZE (decl) == 0) 1762 { 1763 error ("storage size of %q+D isn%'t known", decl); 1764 TREE_ASM_WRITTEN (decl) = 1; 1765 return; 1766 } 1767 1768 /* The first declaration of a variable that comes through this function 1769 decides whether it is global (in C, has external linkage) 1770 or local (in C, has internal linkage). So do nothing more 1771 if this function has already run. */ 1772 1773 if (TREE_ASM_WRITTEN (decl)) 1774 return; 1775 1776 /* Make sure targetm.encode_section_info is invoked before we set 1777 ASM_WRITTEN. */ 1778 decl_rtl = DECL_RTL (decl); 1779 1780 TREE_ASM_WRITTEN (decl) = 1; 1781 1782 /* Do no output if -fsyntax-only. */ 1783 if (flag_syntax_only) 1784 return; 1785 1786 app_disable (); 1787 1788 if (! dont_output_data 1789 && ! host_integerp (DECL_SIZE_UNIT (decl), 1)) 1790 { 1791 error ("size of variable %q+D is too large", decl); 1792 return; 1793 } 1794 1795 gcc_assert (MEM_P (decl_rtl)); 1796 gcc_assert (GET_CODE (XEXP (decl_rtl, 0)) == SYMBOL_REF); 1797 symbol = XEXP (decl_rtl, 0); 1798 name = XSTR (symbol, 0); 1799 if (TREE_PUBLIC (decl) && DECL_NAME (decl)) 1800 notice_global_symbol (decl); 1801 1802 /* Compute the alignment of this data. */ 1803 1804 align_variable (decl, dont_output_data); 1805 set_mem_align (decl_rtl, DECL_ALIGN (decl)); 1806 1807 if (TREE_PUBLIC (decl)) 1808 maybe_assemble_visibility (decl); 1809 1810 if (DECL_PRESERVE_P (decl)) 1811 targetm.asm_out.mark_decl_preserved (name); 1812 1813 /* First make the assembler name(s) global if appropriate. */ 1814 sect = get_variable_section (decl, false); 1815 if (TREE_PUBLIC (decl) 1816 && DECL_NAME (decl) 1817 && (sect->common.flags & SECTION_COMMON) == 0) 1818 globalize_decl (decl); 1819 1820 /* Output any data that we will need to use the address of. */ 1821 if (DECL_INITIAL (decl) && DECL_INITIAL (decl) != error_mark_node) 1822 output_addressed_constants (DECL_INITIAL (decl)); 1823 1824 /* dbxout.c needs to know this. */ 1825 if (sect && (sect->common.flags & SECTION_CODE) != 0) 1826 DECL_IN_TEXT_SECTION (decl) = 1; 1827 1828 /* If the decl is part of an object_block, make sure that the decl 1829 has been positioned within its block, but do not write out its 1830 definition yet. output_object_blocks will do that later. */ 1831 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol)) 1832 { 1833 gcc_assert (!dont_output_data); 1834 place_block_symbol (symbol); 1835 } 1836 else if (SECTION_STYLE (sect) == SECTION_NOSWITCH) 1837 assemble_noswitch_variable (decl, name, sect); 1838 else 1839 { 1840 switch_to_section (sect); 1841 if (DECL_ALIGN (decl) > BITS_PER_UNIT) 1842 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (DECL_ALIGN_UNIT (decl))); 1843 assemble_variable_contents (decl, name, dont_output_data); 1844 } 1845} 1846 1847/* Return 1 if type TYPE contains any pointers. */ 1848 1849static int 1850contains_pointers_p (tree type) 1851{ 1852 switch (TREE_CODE (type)) 1853 { 1854 case POINTER_TYPE: 1855 case REFERENCE_TYPE: 1856 /* I'm not sure whether OFFSET_TYPE needs this treatment, 1857 so I'll play safe and return 1. */ 1858 case OFFSET_TYPE: 1859 return 1; 1860 1861 case RECORD_TYPE: 1862 case UNION_TYPE: 1863 case QUAL_UNION_TYPE: 1864 { 1865 tree fields; 1866 /* For a type that has fields, see if the fields have pointers. */ 1867 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields)) 1868 if (TREE_CODE (fields) == FIELD_DECL 1869 && contains_pointers_p (TREE_TYPE (fields))) 1870 return 1; 1871 return 0; 1872 } 1873 1874 case ARRAY_TYPE: 1875 /* An array type contains pointers if its element type does. */ 1876 return contains_pointers_p (TREE_TYPE (type)); 1877 1878 default: 1879 return 0; 1880 } 1881} 1882 1883/* In unit-at-a-time mode, we delay assemble_external processing until 1884 the compilation unit is finalized. This is the best we can do for 1885 right now (i.e. stage 3 of GCC 4.0) - the right thing is to delay 1886 it all the way to final. See PR 17982 for further discussion. */ 1887static GTY(()) tree pending_assemble_externals; 1888 1889#ifdef ASM_OUTPUT_EXTERNAL 1890/* True if DECL is a function decl for which no out-of-line copy exists. 1891 It is assumed that DECL's assembler name has been set. */ 1892 1893static bool 1894incorporeal_function_p (tree decl) 1895{ 1896 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl)) 1897 { 1898 const char *name; 1899 1900 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL 1901 && DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA) 1902 return true; 1903 1904 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)); 1905 if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0) 1906 return true; 1907 } 1908 return false; 1909} 1910 1911/* Actually do the tests to determine if this is necessary, and invoke 1912 ASM_OUTPUT_EXTERNAL. */ 1913static void 1914assemble_external_real (tree decl) 1915{ 1916 rtx rtl = DECL_RTL (decl); 1917 1918 if (MEM_P (rtl) && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF 1919 && !SYMBOL_REF_USED (XEXP (rtl, 0)) 1920 && !incorporeal_function_p (decl)) 1921 { 1922 /* Some systems do require some output. */ 1923 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1; 1924 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0)); 1925 } 1926} 1927#endif 1928 1929void 1930process_pending_assemble_externals (void) 1931{ 1932#ifdef ASM_OUTPUT_EXTERNAL 1933 tree list; 1934 for (list = pending_assemble_externals; list; list = TREE_CHAIN (list)) 1935 assemble_external_real (TREE_VALUE (list)); 1936 1937 pending_assemble_externals = 0; 1938#endif 1939} 1940 1941/* Output something to declare an external symbol to the assembler. 1942 (Most assemblers don't need this, so we normally output nothing.) 1943 Do nothing if DECL is not external. */ 1944 1945void 1946assemble_external (tree decl ATTRIBUTE_UNUSED) 1947{ 1948 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the 1949 main body of this code is only rarely exercised. To provide some 1950 testing, on all platforms, we make sure that the ASM_OUT_FILE is 1951 open. If it's not, we should not be calling this function. */ 1952 gcc_assert (asm_out_file); 1953 1954#ifdef ASM_OUTPUT_EXTERNAL 1955 if (!DECL_P (decl) || !DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl)) 1956 return; 1957 1958 /* We want to output external symbols at very last to check if they 1959 are references or not. */ 1960 pending_assemble_externals = tree_cons (0, decl, 1961 pending_assemble_externals); 1962#endif 1963} 1964 1965/* Similar, for calling a library function FUN. */ 1966 1967void 1968assemble_external_libcall (rtx fun) 1969{ 1970 /* Declare library function name external when first used, if nec. */ 1971 if (! SYMBOL_REF_USED (fun)) 1972 { 1973 SYMBOL_REF_USED (fun) = 1; 1974 targetm.asm_out.external_libcall (fun); 1975 } 1976} 1977 1978/* Assemble a label named NAME. */ 1979 1980void 1981assemble_label (const char *name) 1982{ 1983 ASM_OUTPUT_LABEL (asm_out_file, name); 1984} 1985 1986/* Set the symbol_referenced flag for ID. */ 1987void 1988mark_referenced (tree id) 1989{ 1990 TREE_SYMBOL_REFERENCED (id) = 1; 1991} 1992 1993/* Set the symbol_referenced flag for DECL and notify callgraph. */ 1994void 1995mark_decl_referenced (tree decl) 1996{ 1997 if (TREE_CODE (decl) == FUNCTION_DECL) 1998 { 1999 /* Extern inline functions don't become needed when referenced. 2000 If we know a method will be emitted in other TU and no new 2001 functions can be marked reachable, just use the external 2002 definition. */ 2003 struct cgraph_node *node = cgraph_node (decl); 2004 if (!DECL_EXTERNAL (decl) 2005 && (!node->local.vtable_method || !cgraph_global_info_ready 2006 || !node->local.finalized)) 2007 cgraph_mark_needed_node (node); 2008 } 2009 else if (TREE_CODE (decl) == VAR_DECL) 2010 { 2011 struct cgraph_varpool_node *node = cgraph_varpool_node (decl); 2012 cgraph_varpool_mark_needed_node (node); 2013 /* C++ frontend use mark_decl_references to force COMDAT variables 2014 to be output that might appear dead otherwise. */ 2015 node->force_output = true; 2016 } 2017 /* else do nothing - we can get various sorts of CST nodes here, 2018 which do not need to be marked. */ 2019} 2020 2021 2022/* Follow the IDENTIFIER_TRANSPARENT_ALIAS chain starting at *ALIAS 2023 until we find an identifier that is not itself a transparent alias. 2024 Modify the alias passed to it by reference (and all aliases on the 2025 way to the ultimate target), such that they do not have to be 2026 followed again, and return the ultimate target of the alias 2027 chain. */ 2028 2029static inline tree 2030ultimate_transparent_alias_target (tree *alias) 2031{ 2032 tree target = *alias; 2033 2034 if (IDENTIFIER_TRANSPARENT_ALIAS (target)) 2035 { 2036 gcc_assert (TREE_CHAIN (target)); 2037 target = ultimate_transparent_alias_target (&TREE_CHAIN (target)); 2038 gcc_assert (! IDENTIFIER_TRANSPARENT_ALIAS (target) 2039 && ! TREE_CHAIN (target)); 2040 *alias = target; 2041 } 2042 2043 return target; 2044} 2045 2046/* Output to FILE (an assembly file) a reference to NAME. If NAME 2047 starts with a *, the rest of NAME is output verbatim. Otherwise 2048 NAME is transformed in a target-specific way (usually by the 2049 addition of an underscore). */ 2050 2051void 2052assemble_name_raw (FILE *file, const char *name) 2053{ 2054 if (name[0] == '*') 2055 fputs (&name[1], file); 2056 else 2057 ASM_OUTPUT_LABELREF (file, name); 2058} 2059 2060/* Like assemble_name_raw, but should be used when NAME might refer to 2061 an entity that is also represented as a tree (like a function or 2062 variable). If NAME does refer to such an entity, that entity will 2063 be marked as referenced. */ 2064 2065void 2066assemble_name (FILE *file, const char *name) 2067{ 2068 const char *real_name; 2069 tree id; 2070 2071 real_name = targetm.strip_name_encoding (name); 2072 2073 id = maybe_get_identifier (real_name); 2074 if (id) 2075 { 2076 tree id_orig = id; 2077 2078 mark_referenced (id); 2079 ultimate_transparent_alias_target (&id); 2080 if (id != id_orig) 2081 name = IDENTIFIER_POINTER (id); 2082 gcc_assert (! TREE_CHAIN (id)); 2083 } 2084 2085 assemble_name_raw (file, name); 2086} 2087 2088/* Allocate SIZE bytes writable static space with a gensym name 2089 and return an RTX to refer to its address. */ 2090 2091rtx 2092assemble_static_space (unsigned HOST_WIDE_INT size) 2093{ 2094 char name[12]; 2095 const char *namestring; 2096 rtx x; 2097 2098 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno); 2099 ++const_labelno; 2100 namestring = ggc_strdup (name); 2101 2102 x = gen_rtx_SYMBOL_REF (Pmode, namestring); 2103 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL; 2104 2105#ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL 2106 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size, 2107 BIGGEST_ALIGNMENT); 2108#else 2109#ifdef ASM_OUTPUT_ALIGNED_LOCAL 2110 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT); 2111#else 2112 { 2113 /* Round size up to multiple of BIGGEST_ALIGNMENT bits 2114 so that each uninitialized object starts on such a boundary. */ 2115 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */ 2116 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED 2117 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1) 2118 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT) 2119 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT)); 2120 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded); 2121 } 2122#endif 2123#endif 2124 return x; 2125} 2126 2127/* Assemble the static constant template for function entry trampolines. 2128 This is done at most once per compilation. 2129 Returns an RTX for the address of the template. */ 2130 2131static GTY(()) rtx initial_trampoline; 2132 2133#ifdef TRAMPOLINE_TEMPLATE 2134rtx 2135assemble_trampoline_template (void) 2136{ 2137 char label[256]; 2138 const char *name; 2139 int align; 2140 rtx symbol; 2141 2142 if (initial_trampoline) 2143 return initial_trampoline; 2144 2145 /* By default, put trampoline templates in read-only data section. */ 2146 2147#ifdef TRAMPOLINE_SECTION 2148 switch_to_section (TRAMPOLINE_SECTION); 2149#else 2150 switch_to_section (readonly_data_section); 2151#endif 2152 2153 /* Write the assembler code to define one. */ 2154 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT); 2155 if (align > 0) 2156 { 2157 ASM_OUTPUT_ALIGN (asm_out_file, align); 2158 } 2159 2160 targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0); 2161 TRAMPOLINE_TEMPLATE (asm_out_file); 2162 2163 /* Record the rtl to refer to it. */ 2164 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0); 2165 name = ggc_strdup (label); 2166 symbol = gen_rtx_SYMBOL_REF (Pmode, name); 2167 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL; 2168 2169 initial_trampoline = gen_rtx_MEM (BLKmode, symbol); 2170 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT); 2171 2172 return initial_trampoline; 2173} 2174#endif 2175 2176/* A and B are either alignments or offsets. Return the minimum alignment 2177 that may be assumed after adding the two together. */ 2178 2179static inline unsigned 2180min_align (unsigned int a, unsigned int b) 2181{ 2182 return (a | b) & -(a | b); 2183} 2184 2185/* Return the assembler directive for creating a given kind of integer 2186 object. SIZE is the number of bytes in the object and ALIGNED_P 2187 indicates whether it is known to be aligned. Return NULL if the 2188 assembly dialect has no such directive. 2189 2190 The returned string should be printed at the start of a new line and 2191 be followed immediately by the object's initial value. */ 2192 2193const char * 2194integer_asm_op (int size, int aligned_p) 2195{ 2196 struct asm_int_op *ops; 2197 2198 if (aligned_p) 2199 ops = &targetm.asm_out.aligned_op; 2200 else 2201 ops = &targetm.asm_out.unaligned_op; 2202 2203 switch (size) 2204 { 2205 case 1: 2206 return targetm.asm_out.byte_op; 2207 case 2: 2208 return ops->hi; 2209 case 4: 2210 return ops->si; 2211 case 8: 2212 return ops->di; 2213 case 16: 2214 return ops->ti; 2215 default: 2216 return NULL; 2217 } 2218} 2219 2220/* Use directive OP to assemble an integer object X. Print OP at the 2221 start of the line, followed immediately by the value of X. */ 2222 2223void 2224assemble_integer_with_op (const char *op, rtx x) 2225{ 2226 fputs (op, asm_out_file); 2227 output_addr_const (asm_out_file, x); 2228 fputc ('\n', asm_out_file); 2229} 2230 2231/* The default implementation of the asm_out.integer target hook. */ 2232 2233bool 2234default_assemble_integer (rtx x ATTRIBUTE_UNUSED, 2235 unsigned int size ATTRIBUTE_UNUSED, 2236 int aligned_p ATTRIBUTE_UNUSED) 2237{ 2238 const char *op = integer_asm_op (size, aligned_p); 2239 /* Avoid GAS bugs for large values. Specifically negative values whose 2240 absolute value fits in a bfd_vma, but not in a bfd_signed_vma. */ 2241 if (size > UNITS_PER_WORD && size > POINTER_SIZE / BITS_PER_UNIT) 2242 return false; 2243 return op && (assemble_integer_with_op (op, x), true); 2244} 2245 2246/* Assemble the integer constant X into an object of SIZE bytes. ALIGN is 2247 the alignment of the integer in bits. Return 1 if we were able to output 2248 the constant, otherwise 0. We must be able to output the constant, 2249 if FORCE is nonzero. */ 2250 2251bool 2252assemble_integer (rtx x, unsigned int size, unsigned int align, int force) 2253{ 2254 int aligned_p; 2255 2256 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT)); 2257 2258 /* See if the target hook can handle this kind of object. */ 2259 if (targetm.asm_out.integer (x, size, aligned_p)) 2260 return true; 2261 2262 /* If the object is a multi-byte one, try splitting it up. Split 2263 it into words it if is multi-word, otherwise split it into bytes. */ 2264 if (size > 1) 2265 { 2266 enum machine_mode omode, imode; 2267 unsigned int subalign; 2268 unsigned int subsize, i; 2269 2270 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1; 2271 subalign = MIN (align, subsize * BITS_PER_UNIT); 2272 omode = mode_for_size (subsize * BITS_PER_UNIT, MODE_INT, 0); 2273 imode = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0); 2274 2275 for (i = 0; i < size; i += subsize) 2276 { 2277 rtx partial = simplify_subreg (omode, x, imode, i); 2278 if (!partial || !assemble_integer (partial, subsize, subalign, 0)) 2279 break; 2280 } 2281 if (i == size) 2282 return true; 2283 2284 /* If we've printed some of it, but not all of it, there's no going 2285 back now. */ 2286 gcc_assert (!i); 2287 } 2288 2289 gcc_assert (!force); 2290 2291 return false; 2292} 2293 2294void 2295assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align) 2296{ 2297 long data[4] = {0, 0, 0, 0}; 2298 int i; 2299 int bitsize, nelts, nunits, units_per; 2300 2301 /* This is hairy. We have a quantity of known size. real_to_target 2302 will put it into an array of *host* longs, 32 bits per element 2303 (even if long is more than 32 bits). We need to determine the 2304 number of array elements that are occupied (nelts) and the number 2305 of *target* min-addressable units that will be occupied in the 2306 object file (nunits). We cannot assume that 32 divides the 2307 mode's bitsize (size * BITS_PER_UNIT) evenly. 2308 2309 size * BITS_PER_UNIT is used here to make sure that padding bits 2310 (which might appear at either end of the value; real_to_target 2311 will include the padding bits in its output array) are included. */ 2312 2313 nunits = GET_MODE_SIZE (mode); 2314 bitsize = nunits * BITS_PER_UNIT; 2315 nelts = CEIL (bitsize, 32); 2316 units_per = 32 / BITS_PER_UNIT; 2317 2318 real_to_target (data, &d, mode); 2319 2320 /* Put out the first word with the specified alignment. */ 2321 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1); 2322 nunits -= units_per; 2323 2324 /* Subsequent words need only 32-bit alignment. */ 2325 align = min_align (align, 32); 2326 2327 for (i = 1; i < nelts; i++) 2328 { 2329 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1); 2330 nunits -= units_per; 2331 } 2332} 2333 2334/* Given an expression EXP with a constant value, 2335 reduce it to the sum of an assembler symbol and an integer. 2336 Store them both in the structure *VALUE. 2337 EXP must be reducible. */ 2338 2339struct addr_const GTY(()) 2340{ 2341 rtx base; 2342 HOST_WIDE_INT offset; 2343}; 2344 2345static void 2346decode_addr_const (tree exp, struct addr_const *value) 2347{ 2348 tree target = TREE_OPERAND (exp, 0); 2349 int offset = 0; 2350 rtx x; 2351 2352 while (1) 2353 { 2354 if (TREE_CODE (target) == COMPONENT_REF 2355 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0)) 2356 2357 { 2358 offset += int_byte_position (TREE_OPERAND (target, 1)); 2359 target = TREE_OPERAND (target, 0); 2360 } 2361 else if (TREE_CODE (target) == ARRAY_REF 2362 || TREE_CODE (target) == ARRAY_RANGE_REF) 2363 { 2364 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1) 2365 * tree_low_cst (TREE_OPERAND (target, 1), 0)); 2366 target = TREE_OPERAND (target, 0); 2367 } 2368 else 2369 break; 2370 } 2371 2372 switch (TREE_CODE (target)) 2373 { 2374 case VAR_DECL: 2375 case FUNCTION_DECL: 2376 x = DECL_RTL (target); 2377 break; 2378 2379 case LABEL_DECL: 2380 x = gen_rtx_MEM (FUNCTION_MODE, 2381 gen_rtx_LABEL_REF (Pmode, force_label_rtx (target))); 2382 break; 2383 2384 case REAL_CST: 2385 case STRING_CST: 2386 case COMPLEX_CST: 2387 case CONSTRUCTOR: 2388 case INTEGER_CST: 2389 x = output_constant_def (target, 1); 2390 break; 2391 2392 default: 2393 gcc_unreachable (); 2394 } 2395 2396 gcc_assert (MEM_P (x)); 2397 x = XEXP (x, 0); 2398 2399 value->base = x; 2400 value->offset = offset; 2401} 2402 2403/* Uniquize all constants that appear in memory. 2404 Each constant in memory thus far output is recorded 2405 in `const_desc_table'. */ 2406 2407struct constant_descriptor_tree GTY(()) 2408{ 2409 /* A MEM for the constant. */ 2410 rtx rtl; 2411 2412 /* The value of the constant. */ 2413 tree value; 2414 2415 /* Hash of value. Computing the hash from value each time 2416 hashfn is called can't work properly, as that means recursive 2417 use of the hash table during hash table expansion. */ 2418 hashval_t hash; 2419}; 2420 2421static GTY((param_is (struct constant_descriptor_tree))) 2422 htab_t const_desc_htab; 2423 2424static struct constant_descriptor_tree * build_constant_desc (tree); 2425static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int); 2426 2427/* Compute a hash code for a constant expression. */ 2428 2429static hashval_t 2430const_desc_hash (const void *ptr) 2431{ 2432 return ((struct constant_descriptor_tree *)ptr)->hash; 2433} 2434 2435static hashval_t 2436const_hash_1 (const tree exp) 2437{ 2438 const char *p; 2439 hashval_t hi; 2440 int len, i; 2441 enum tree_code code = TREE_CODE (exp); 2442 2443 /* Either set P and LEN to the address and len of something to hash and 2444 exit the switch or return a value. */ 2445 2446 switch (code) 2447 { 2448 case INTEGER_CST: 2449 p = (char *) &TREE_INT_CST (exp); 2450 len = sizeof TREE_INT_CST (exp); 2451 break; 2452 2453 case REAL_CST: 2454 return real_hash (TREE_REAL_CST_PTR (exp)); 2455 2456 case STRING_CST: 2457 p = TREE_STRING_POINTER (exp); 2458 len = TREE_STRING_LENGTH (exp); 2459 break; 2460 2461 case COMPLEX_CST: 2462 return (const_hash_1 (TREE_REALPART (exp)) * 5 2463 + const_hash_1 (TREE_IMAGPART (exp))); 2464 2465 case CONSTRUCTOR: 2466 { 2467 unsigned HOST_WIDE_INT idx; 2468 tree value; 2469 2470 hi = 5 + int_size_in_bytes (TREE_TYPE (exp)); 2471 2472 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, value) 2473 if (value) 2474 hi = hi * 603 + const_hash_1 (value); 2475 2476 return hi; 2477 } 2478 2479 case ADDR_EXPR: 2480 case FDESC_EXPR: 2481 { 2482 struct addr_const value; 2483 2484 decode_addr_const (exp, &value); 2485 switch (GET_CODE (value.base)) 2486 { 2487 case SYMBOL_REF: 2488 /* Don't hash the address of the SYMBOL_REF; 2489 only use the offset and the symbol name. */ 2490 hi = value.offset; 2491 p = XSTR (value.base, 0); 2492 for (i = 0; p[i] != 0; i++) 2493 hi = ((hi * 613) + (unsigned) (p[i])); 2494 break; 2495 2496 case LABEL_REF: 2497 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13; 2498 break; 2499 2500 default: 2501 gcc_unreachable (); 2502 } 2503 } 2504 return hi; 2505 2506 case PLUS_EXPR: 2507 case MINUS_EXPR: 2508 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9 2509 + const_hash_1 (TREE_OPERAND (exp, 1))); 2510 2511 case NOP_EXPR: 2512 case CONVERT_EXPR: 2513 case NON_LVALUE_EXPR: 2514 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2; 2515 2516 default: 2517 /* A language specific constant. Just hash the code. */ 2518 return code; 2519 } 2520 2521 /* Compute hashing function. */ 2522 hi = len; 2523 for (i = 0; i < len; i++) 2524 hi = ((hi * 613) + (unsigned) (p[i])); 2525 2526 return hi; 2527} 2528 2529/* Wrapper of compare_constant, for the htab interface. */ 2530static int 2531const_desc_eq (const void *p1, const void *p2) 2532{ 2533 const struct constant_descriptor_tree *c1 = p1; 2534 const struct constant_descriptor_tree *c2 = p2; 2535 if (c1->hash != c2->hash) 2536 return 0; 2537 return compare_constant (c1->value, c2->value); 2538} 2539 2540/* Compare t1 and t2, and return 1 only if they are known to result in 2541 the same bit pattern on output. */ 2542 2543static int 2544compare_constant (const tree t1, const tree t2) 2545{ 2546 enum tree_code typecode; 2547 2548 if (t1 == NULL_TREE) 2549 return t2 == NULL_TREE; 2550 if (t2 == NULL_TREE) 2551 return 0; 2552 2553 if (TREE_CODE (t1) != TREE_CODE (t2)) 2554 return 0; 2555 2556 switch (TREE_CODE (t1)) 2557 { 2558 case INTEGER_CST: 2559 /* Integer constants are the same only if the same width of type. */ 2560 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2))) 2561 return 0; 2562 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))) 2563 return 0; 2564 return tree_int_cst_equal (t1, t2); 2565 2566 case REAL_CST: 2567 /* Real constants are the same only if the same width of type. */ 2568 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2))) 2569 return 0; 2570 2571 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2)); 2572 2573 case STRING_CST: 2574 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))) 2575 return 0; 2576 2577 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2) 2578 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2), 2579 TREE_STRING_LENGTH (t1))); 2580 2581 case COMPLEX_CST: 2582 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2)) 2583 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2))); 2584 2585 case CONSTRUCTOR: 2586 { 2587 VEC(constructor_elt, gc) *v1, *v2; 2588 unsigned HOST_WIDE_INT idx; 2589 2590 typecode = TREE_CODE (TREE_TYPE (t1)); 2591 if (typecode != TREE_CODE (TREE_TYPE (t2))) 2592 return 0; 2593 2594 if (typecode == ARRAY_TYPE) 2595 { 2596 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1)); 2597 /* For arrays, check that the sizes all match. */ 2598 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)) 2599 || size_1 == -1 2600 || size_1 != int_size_in_bytes (TREE_TYPE (t2))) 2601 return 0; 2602 } 2603 else 2604 { 2605 /* For record and union constructors, require exact type 2606 equality. */ 2607 if (TREE_TYPE (t1) != TREE_TYPE (t2)) 2608 return 0; 2609 } 2610 2611 v1 = CONSTRUCTOR_ELTS (t1); 2612 v2 = CONSTRUCTOR_ELTS (t2); 2613 if (VEC_length (constructor_elt, v1) 2614 != VEC_length (constructor_elt, v2)) 2615 return 0; 2616 2617 for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx) 2618 { 2619 constructor_elt *c1 = VEC_index (constructor_elt, v1, idx); 2620 constructor_elt *c2 = VEC_index (constructor_elt, v2, idx); 2621 2622 /* Check that each value is the same... */ 2623 if (!compare_constant (c1->value, c2->value)) 2624 return 0; 2625 /* ... and that they apply to the same fields! */ 2626 if (typecode == ARRAY_TYPE) 2627 { 2628 if (!compare_constant (c1->index, c2->index)) 2629 return 0; 2630 } 2631 else 2632 { 2633 if (c1->index != c2->index) 2634 return 0; 2635 } 2636 } 2637 2638 return 1; 2639 } 2640 2641 case ADDR_EXPR: 2642 case FDESC_EXPR: 2643 { 2644 struct addr_const value1, value2; 2645 2646 decode_addr_const (t1, &value1); 2647 decode_addr_const (t2, &value2); 2648 return (value1.offset == value2.offset 2649 && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0); 2650 } 2651 2652 case PLUS_EXPR: 2653 case MINUS_EXPR: 2654 case RANGE_EXPR: 2655 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)) 2656 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1))); 2657 2658 case NOP_EXPR: 2659 case CONVERT_EXPR: 2660 case NON_LVALUE_EXPR: 2661 case VIEW_CONVERT_EXPR: 2662 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)); 2663 2664 default: 2665 { 2666 tree nt1, nt2; 2667 nt1 = lang_hooks.expand_constant (t1); 2668 nt2 = lang_hooks.expand_constant (t2); 2669 if (nt1 != t1 || nt2 != t2) 2670 return compare_constant (nt1, nt2); 2671 else 2672 return 0; 2673 } 2674 } 2675 2676 gcc_unreachable (); 2677} 2678 2679/* Make a copy of the whole tree structure for a constant. This 2680 handles the same types of nodes that compare_constant handles. */ 2681 2682static tree 2683copy_constant (tree exp) 2684{ 2685 switch (TREE_CODE (exp)) 2686 { 2687 case ADDR_EXPR: 2688 /* For ADDR_EXPR, we do not want to copy the decl whose address 2689 is requested. We do want to copy constants though. */ 2690 if (CONSTANT_CLASS_P (TREE_OPERAND (exp, 0))) 2691 return build1 (TREE_CODE (exp), TREE_TYPE (exp), 2692 copy_constant (TREE_OPERAND (exp, 0))); 2693 else 2694 return copy_node (exp); 2695 2696 case INTEGER_CST: 2697 case REAL_CST: 2698 case STRING_CST: 2699 return copy_node (exp); 2700 2701 case COMPLEX_CST: 2702 return build_complex (TREE_TYPE (exp), 2703 copy_constant (TREE_REALPART (exp)), 2704 copy_constant (TREE_IMAGPART (exp))); 2705 2706 case PLUS_EXPR: 2707 case MINUS_EXPR: 2708 return build2 (TREE_CODE (exp), TREE_TYPE (exp), 2709 copy_constant (TREE_OPERAND (exp, 0)), 2710 copy_constant (TREE_OPERAND (exp, 1))); 2711 2712 case NOP_EXPR: 2713 case CONVERT_EXPR: 2714 case NON_LVALUE_EXPR: 2715 case VIEW_CONVERT_EXPR: 2716 return build1 (TREE_CODE (exp), TREE_TYPE (exp), 2717 copy_constant (TREE_OPERAND (exp, 0))); 2718 2719 case CONSTRUCTOR: 2720 { 2721 tree copy = copy_node (exp); 2722 VEC(constructor_elt, gc) *v; 2723 unsigned HOST_WIDE_INT idx; 2724 tree purpose, value; 2725 2726 v = VEC_alloc(constructor_elt, gc, VEC_length(constructor_elt, 2727 CONSTRUCTOR_ELTS (exp))); 2728 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (exp), idx, purpose, value) 2729 { 2730 constructor_elt *ce = VEC_quick_push (constructor_elt, v, NULL); 2731 ce->index = purpose; 2732 ce->value = copy_constant (value); 2733 } 2734 CONSTRUCTOR_ELTS (copy) = v; 2735 return copy; 2736 } 2737 2738 default: 2739 { 2740 tree t = lang_hooks.expand_constant (exp); 2741 2742 gcc_assert (t != exp); 2743 return copy_constant (t); 2744 } 2745 } 2746} 2747 2748/* Return the alignment of constant EXP in bits. */ 2749 2750static unsigned int 2751get_constant_alignment (tree exp) 2752{ 2753 unsigned int align; 2754 2755 align = TYPE_ALIGN (TREE_TYPE (exp)); 2756#ifdef CONSTANT_ALIGNMENT 2757 align = CONSTANT_ALIGNMENT (exp, align); 2758#endif 2759 return align; 2760} 2761 2762/* Return the section into which constant EXP should be placed. */ 2763 2764static section * 2765get_constant_section (tree exp) 2766{ 2767 if (IN_NAMED_SECTION (exp)) 2768 return get_named_section (exp, NULL, compute_reloc_for_constant (exp)); 2769 else 2770 return targetm.asm_out.select_section (exp, 2771 compute_reloc_for_constant (exp), 2772 get_constant_alignment (exp)); 2773} 2774 2775/* Return the size of constant EXP in bytes. */ 2776 2777static HOST_WIDE_INT 2778get_constant_size (tree exp) 2779{ 2780 HOST_WIDE_INT size; 2781 2782 size = int_size_in_bytes (TREE_TYPE (exp)); 2783 if (TREE_CODE (exp) == STRING_CST) 2784 size = MAX (TREE_STRING_LENGTH (exp), size); 2785 return size; 2786} 2787 2788/* Subroutine of output_constant_def: 2789 No constant equal to EXP is known to have been output. 2790 Make a constant descriptor to enter EXP in the hash table. 2791 Assign the label number and construct RTL to refer to the 2792 constant's location in memory. 2793 Caller is responsible for updating the hash table. */ 2794 2795static struct constant_descriptor_tree * 2796build_constant_desc (tree exp) 2797{ 2798 rtx symbol; 2799 rtx rtl; 2800 char label[256]; 2801 int labelno; 2802 struct constant_descriptor_tree *desc; 2803 2804 desc = ggc_alloc (sizeof (*desc)); 2805 desc->value = copy_constant (exp); 2806 2807 /* Propagate marked-ness to copied constant. */ 2808 if (flag_mudflap && mf_marked_p (exp)) 2809 mf_mark (desc->value); 2810 2811 /* Create a string containing the label name, in LABEL. */ 2812 labelno = const_labelno++; 2813 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno); 2814 2815 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */ 2816 if (use_object_blocks_p ()) 2817 { 2818 section *sect = get_constant_section (exp); 2819 symbol = create_block_symbol (ggc_strdup (label), 2820 get_block_for_section (sect), -1); 2821 } 2822 else 2823 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label)); 2824 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL; 2825 SET_SYMBOL_REF_DECL (symbol, desc->value); 2826 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1; 2827 2828 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol); 2829 set_mem_attributes (rtl, exp, 1); 2830 set_mem_alias_set (rtl, 0); 2831 set_mem_alias_set (rtl, const_alias_set); 2832 2833 /* Set flags or add text to the name to record information, such as 2834 that it is a local symbol. If the name is changed, the macro 2835 ASM_OUTPUT_LABELREF will have to know how to strip this 2836 information. This call might invalidate our local variable 2837 SYMBOL; we can't use it afterward. */ 2838 2839 targetm.encode_section_info (exp, rtl, true); 2840 2841 desc->rtl = rtl; 2842 2843 return desc; 2844} 2845 2846/* Return an rtx representing a reference to constant data in memory 2847 for the constant expression EXP. 2848 2849 If assembler code for such a constant has already been output, 2850 return an rtx to refer to it. 2851 Otherwise, output such a constant in memory 2852 and generate an rtx for it. 2853 2854 If DEFER is nonzero, this constant can be deferred and output only 2855 if referenced in the function after all optimizations. 2856 2857 `const_desc_table' records which constants already have label strings. */ 2858 2859rtx 2860output_constant_def (tree exp, int defer) 2861{ 2862 struct constant_descriptor_tree *desc; 2863 struct constant_descriptor_tree key; 2864 void **loc; 2865 2866 /* Look up EXP in the table of constant descriptors. If we didn't find 2867 it, create a new one. */ 2868 key.value = exp; 2869 key.hash = const_hash_1 (exp); 2870 loc = htab_find_slot_with_hash (const_desc_htab, &key, key.hash, INSERT); 2871 2872 desc = *loc; 2873 if (desc == 0) 2874 { 2875 desc = build_constant_desc (exp); 2876 desc->hash = key.hash; 2877 *loc = desc; 2878 } 2879 2880 maybe_output_constant_def_contents (desc, defer); 2881 return desc->rtl; 2882} 2883 2884/* Subroutine of output_constant_def: Decide whether or not we need to 2885 output the constant DESC now, and if so, do it. */ 2886static void 2887maybe_output_constant_def_contents (struct constant_descriptor_tree *desc, 2888 int defer) 2889{ 2890 rtx symbol = XEXP (desc->rtl, 0); 2891 tree exp = desc->value; 2892 2893 if (flag_syntax_only) 2894 return; 2895 2896 if (TREE_ASM_WRITTEN (exp)) 2897 /* Already output; don't do it again. */ 2898 return; 2899 2900 /* We can always defer constants as long as the context allows 2901 doing so. */ 2902 if (defer) 2903 { 2904 /* Increment n_deferred_constants if it exists. It needs to be at 2905 least as large as the number of constants actually referred to 2906 by the function. If it's too small we'll stop looking too early 2907 and fail to emit constants; if it's too large we'll only look 2908 through the entire function when we could have stopped earlier. */ 2909 if (cfun) 2910 n_deferred_constants++; 2911 return; 2912 } 2913 2914 output_constant_def_contents (symbol); 2915} 2916 2917/* Subroutine of output_constant_def_contents. Output the definition 2918 of constant EXP, which is pointed to by label LABEL. ALIGN is the 2919 constant's alignment in bits. */ 2920 2921static void 2922assemble_constant_contents (tree exp, const char *label, unsigned int align) 2923{ 2924 HOST_WIDE_INT size; 2925 2926 size = get_constant_size (exp); 2927 2928 /* Do any machine/system dependent processing of the constant. */ 2929#ifdef ASM_DECLARE_CONSTANT_NAME 2930 ASM_DECLARE_CONSTANT_NAME (asm_out_file, label, exp, size); 2931#else 2932 /* Standard thing is just output label for the constant. */ 2933 ASM_OUTPUT_LABEL (asm_out_file, label); 2934#endif /* ASM_DECLARE_CONSTANT_NAME */ 2935 2936 /* Output the value of EXP. */ 2937 output_constant (exp, size, align); 2938} 2939 2940/* We must output the constant data referred to by SYMBOL; do so. */ 2941 2942static void 2943output_constant_def_contents (rtx symbol) 2944{ 2945 tree exp = SYMBOL_REF_DECL (symbol); 2946 unsigned int align; 2947 2948 /* Make sure any other constants whose addresses appear in EXP 2949 are assigned label numbers. */ 2950 output_addressed_constants (exp); 2951 2952 /* We are no longer deferring this constant. */ 2953 TREE_ASM_WRITTEN (exp) = 1; 2954 2955 /* If the constant is part of an object block, make sure that the 2956 decl has been positioned within its block, but do not write out 2957 its definition yet. output_object_blocks will do that later. */ 2958 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol)) 2959 place_block_symbol (symbol); 2960 else 2961 { 2962 switch_to_section (get_constant_section (exp)); 2963 align = get_constant_alignment (exp); 2964 if (align > BITS_PER_UNIT) 2965 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT)); 2966 assemble_constant_contents (exp, XSTR (symbol, 0), align); 2967 } 2968 if (flag_mudflap) 2969 mudflap_enqueue_constant (exp); 2970} 2971 2972/* Look up EXP in the table of constant descriptors. Return the rtl 2973 if it has been emitted, else null. */ 2974 2975rtx 2976lookup_constant_def (tree exp) 2977{ 2978 struct constant_descriptor_tree *desc; 2979 struct constant_descriptor_tree key; 2980 2981 key.value = exp; 2982 key.hash = const_hash_1 (exp); 2983 desc = htab_find_with_hash (const_desc_htab, &key, key.hash); 2984 2985 return (desc ? desc->rtl : NULL_RTX); 2986} 2987 2988/* Used in the hash tables to avoid outputting the same constant 2989 twice. Unlike 'struct constant_descriptor_tree', RTX constants 2990 are output once per function, not once per file. */ 2991/* ??? Only a few targets need per-function constant pools. Most 2992 can use one per-file pool. Should add a targetm bit to tell the 2993 difference. */ 2994 2995struct rtx_constant_pool GTY(()) 2996{ 2997 /* Pointers to first and last constant in pool, as ordered by offset. */ 2998 struct constant_descriptor_rtx *first; 2999 struct constant_descriptor_rtx *last; 3000 3001 /* Hash facility for making memory-constants from constant rtl-expressions. 3002 It is used on RISC machines where immediate integer arguments and 3003 constant addresses are restricted so that such constants must be stored 3004 in memory. */ 3005 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab; 3006 3007 /* Current offset in constant pool (does not include any 3008 machine-specific header). */ 3009 HOST_WIDE_INT offset; 3010}; 3011 3012struct constant_descriptor_rtx GTY((chain_next ("%h.next"))) 3013{ 3014 struct constant_descriptor_rtx *next; 3015 rtx mem; 3016 rtx sym; 3017 rtx constant; 3018 HOST_WIDE_INT offset; 3019 hashval_t hash; 3020 enum machine_mode mode; 3021 unsigned int align; 3022 int labelno; 3023 int mark; 3024}; 3025 3026/* Hash and compare functions for const_rtx_htab. */ 3027 3028static hashval_t 3029const_desc_rtx_hash (const void *ptr) 3030{ 3031 const struct constant_descriptor_rtx *desc = ptr; 3032 return desc->hash; 3033} 3034 3035static int 3036const_desc_rtx_eq (const void *a, const void *b) 3037{ 3038 const struct constant_descriptor_rtx *x = a; 3039 const struct constant_descriptor_rtx *y = b; 3040 3041 if (x->mode != y->mode) 3042 return 0; 3043 return rtx_equal_p (x->constant, y->constant); 3044} 3045 3046/* This is the worker function for const_rtx_hash, called via for_each_rtx. */ 3047 3048static int 3049const_rtx_hash_1 (rtx *xp, void *data) 3050{ 3051 unsigned HOST_WIDE_INT hwi; 3052 enum machine_mode mode; 3053 enum rtx_code code; 3054 hashval_t h, *hp; 3055 rtx x; 3056 3057 x = *xp; 3058 code = GET_CODE (x); 3059 mode = GET_MODE (x); 3060 h = (hashval_t) code * 1048573 + mode; 3061 3062 switch (code) 3063 { 3064 case CONST_INT: 3065 hwi = INTVAL (x); 3066 fold_hwi: 3067 { 3068 const int shift = sizeof (hashval_t) * CHAR_BIT; 3069 const int n = sizeof (HOST_WIDE_INT) / sizeof (hashval_t); 3070 int i; 3071 3072 h ^= (hashval_t) hwi; 3073 for (i = 1; i < n; ++i) 3074 { 3075 hwi >>= shift; 3076 h ^= (hashval_t) hwi; 3077 } 3078 } 3079 break; 3080 3081 case CONST_DOUBLE: 3082 if (mode == VOIDmode) 3083 { 3084 hwi = CONST_DOUBLE_LOW (x) ^ CONST_DOUBLE_HIGH (x); 3085 goto fold_hwi; 3086 } 3087 else 3088 h ^= real_hash (CONST_DOUBLE_REAL_VALUE (x)); 3089 break; 3090 3091 case CONST_VECTOR: 3092 { 3093 int i; 3094 for (i = XVECLEN (x, 0); i-- > 0; ) 3095 h = h * 251 + const_rtx_hash_1 (&XVECEXP (x, 0, i), data); 3096 } 3097 break; 3098 3099 case SYMBOL_REF: 3100 h ^= htab_hash_string (XSTR (x, 0)); 3101 break; 3102 3103 case LABEL_REF: 3104 h = h * 251 + CODE_LABEL_NUMBER (XEXP (x, 0)); 3105 break; 3106 3107 case UNSPEC: 3108 case UNSPEC_VOLATILE: 3109 h = h * 251 + XINT (x, 1); 3110 break; 3111 3112 default: 3113 break; 3114 } 3115 3116 hp = data; 3117 *hp = *hp * 509 + h; 3118 return 0; 3119} 3120 3121/* Compute a hash value for X, which should be a constant. */ 3122 3123static hashval_t 3124const_rtx_hash (rtx x) 3125{ 3126 hashval_t h = 0; 3127 for_each_rtx (&x, const_rtx_hash_1, &h); 3128 return h; 3129} 3130 3131 3132/* Create and return a new rtx constant pool. */ 3133 3134static struct rtx_constant_pool * 3135create_constant_pool (void) 3136{ 3137 struct rtx_constant_pool *pool; 3138 3139 pool = ggc_alloc (sizeof (struct rtx_constant_pool)); 3140 pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash, 3141 const_desc_rtx_eq, NULL); 3142 pool->first = NULL; 3143 pool->last = NULL; 3144 pool->offset = 0; 3145 return pool; 3146} 3147 3148/* Initialize constant pool hashing for a new function. */ 3149 3150void 3151init_varasm_status (struct function *f) 3152{ 3153 struct varasm_status *p; 3154 3155 p = ggc_alloc (sizeof (struct varasm_status)); 3156 f->varasm = p; 3157 3158 p->pool = create_constant_pool (); 3159 p->deferred_constants = 0; 3160} 3161 3162/* Given a MINUS expression, simplify it if both sides 3163 include the same symbol. */ 3164 3165rtx 3166simplify_subtraction (rtx x) 3167{ 3168 rtx r = simplify_rtx (x); 3169 return r ? r : x; 3170} 3171 3172/* Given a constant rtx X, make (or find) a memory constant for its value 3173 and return a MEM rtx to refer to it in memory. */ 3174 3175rtx 3176force_const_mem (enum machine_mode mode, rtx x) 3177{ 3178 struct constant_descriptor_rtx *desc, tmp; 3179 struct rtx_constant_pool *pool; 3180 char label[256]; 3181 rtx def, symbol; 3182 hashval_t hash; 3183 unsigned int align; 3184 void **slot; 3185 3186 /* If we're not allowed to drop X into the constant pool, don't. */ 3187 if (targetm.cannot_force_const_mem (x)) 3188 return NULL_RTX; 3189 3190 /* Record that this function has used a constant pool entry. */ 3191 current_function_uses_const_pool = 1; 3192 3193 /* Decide which pool to use. */ 3194 pool = (targetm.use_blocks_for_constant_p (mode, x) 3195 ? shared_constant_pool 3196 : cfun->varasm->pool); 3197 3198 /* Lookup the value in the hashtable. */ 3199 tmp.constant = x; 3200 tmp.mode = mode; 3201 hash = const_rtx_hash (x); 3202 slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT); 3203 desc = *slot; 3204 3205 /* If the constant was already present, return its memory. */ 3206 if (desc) 3207 return copy_rtx (desc->mem); 3208 3209 /* Otherwise, create a new descriptor. */ 3210 desc = ggc_alloc (sizeof (*desc)); 3211 *slot = desc; 3212 3213 /* Align the location counter as required by EXP's data type. */ 3214 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode); 3215#ifdef CONSTANT_ALIGNMENT 3216 { 3217 tree type = lang_hooks.types.type_for_mode (mode, 0); 3218 if (type != NULL_TREE) 3219 align = CONSTANT_ALIGNMENT (make_tree (type, x), align); 3220 } 3221#endif 3222 3223 pool->offset += (align / BITS_PER_UNIT) - 1; 3224 pool->offset &= ~ ((align / BITS_PER_UNIT) - 1); 3225 3226 desc->next = NULL; 3227 desc->constant = tmp.constant; 3228 desc->offset = pool->offset; 3229 desc->hash = hash; 3230 desc->mode = mode; 3231 desc->align = align; 3232 desc->labelno = const_labelno; 3233 desc->mark = 0; 3234 3235 pool->offset += GET_MODE_SIZE (mode); 3236 if (pool->last) 3237 pool->last->next = desc; 3238 else 3239 pool->first = pool->last = desc; 3240 pool->last = desc; 3241 3242 /* Create a string containing the label name, in LABEL. */ 3243 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno); 3244 ++const_labelno; 3245 3246 /* Construct the SYMBOL_REF. Make sure to mark it as belonging to 3247 the constants pool. */ 3248 if (use_object_blocks_p () && targetm.use_blocks_for_constant_p (mode, x)) 3249 { 3250 section *sect = targetm.asm_out.select_rtx_section (mode, x, align); 3251 symbol = create_block_symbol (ggc_strdup (label), 3252 get_block_for_section (sect), -1); 3253 } 3254 else 3255 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label)); 3256 desc->sym = symbol; 3257 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL; 3258 CONSTANT_POOL_ADDRESS_P (symbol) = 1; 3259 SET_SYMBOL_REF_CONSTANT (symbol, desc); 3260 3261 /* Construct the MEM. */ 3262 desc->mem = def = gen_const_mem (mode, symbol); 3263 set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1); 3264 set_mem_align (def, align); 3265 3266 /* If we're dropping a label to the constant pool, make sure we 3267 don't delete it. */ 3268 if (GET_CODE (x) == LABEL_REF) 3269 LABEL_PRESERVE_P (XEXP (x, 0)) = 1; 3270 3271 return copy_rtx (def); 3272} 3273 3274/* Given a constant pool SYMBOL_REF, return the corresponding constant. */ 3275 3276rtx 3277get_pool_constant (rtx addr) 3278{ 3279 return SYMBOL_REF_CONSTANT (addr)->constant; 3280} 3281 3282/* Given a constant pool SYMBOL_REF, return the corresponding constant 3283 and whether it has been output or not. */ 3284 3285rtx 3286get_pool_constant_mark (rtx addr, bool *pmarked) 3287{ 3288 struct constant_descriptor_rtx *desc; 3289 3290 desc = SYMBOL_REF_CONSTANT (addr); 3291 *pmarked = (desc->mark != 0); 3292 return desc->constant; 3293} 3294 3295/* Similar, return the mode. */ 3296 3297enum machine_mode 3298get_pool_mode (rtx addr) 3299{ 3300 return SYMBOL_REF_CONSTANT (addr)->mode; 3301} 3302 3303/* Return the size of the constant pool. */ 3304 3305int 3306get_pool_size (void) 3307{ 3308 return cfun->varasm->pool->offset; 3309} 3310 3311/* Worker function for output_constant_pool_1. Emit assembly for X 3312 in MODE with known alignment ALIGN. */ 3313 3314static void 3315output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align) 3316{ 3317 switch (GET_MODE_CLASS (mode)) 3318 { 3319 case MODE_FLOAT: 3320 case MODE_DECIMAL_FLOAT: 3321 { 3322 REAL_VALUE_TYPE r; 3323 3324 gcc_assert (GET_CODE (x) == CONST_DOUBLE); 3325 REAL_VALUE_FROM_CONST_DOUBLE (r, x); 3326 assemble_real (r, mode, align); 3327 break; 3328 } 3329 3330 case MODE_INT: 3331 case MODE_PARTIAL_INT: 3332 assemble_integer (x, GET_MODE_SIZE (mode), align, 1); 3333 break; 3334 3335 case MODE_VECTOR_FLOAT: 3336 case MODE_VECTOR_INT: 3337 { 3338 int i, units; 3339 enum machine_mode submode = GET_MODE_INNER (mode); 3340 unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode)); 3341 3342 gcc_assert (GET_CODE (x) == CONST_VECTOR); 3343 units = CONST_VECTOR_NUNITS (x); 3344 3345 for (i = 0; i < units; i++) 3346 { 3347 rtx elt = CONST_VECTOR_ELT (x, i); 3348 output_constant_pool_2 (submode, elt, i ? subalign : align); 3349 } 3350 } 3351 break; 3352 3353 default: 3354 gcc_unreachable (); 3355 } 3356} 3357 3358/* Worker function for output_constant_pool. Emit constant DESC, 3359 giving it ALIGN bits of alignment. */ 3360 3361static void 3362output_constant_pool_1 (struct constant_descriptor_rtx *desc, 3363 unsigned int align) 3364{ 3365 rtx x, tmp; 3366 3367 x = desc->constant; 3368 3369 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF) 3370 whose CODE_LABEL has been deleted. This can occur if a jump table 3371 is eliminated by optimization. If so, write a constant of zero 3372 instead. Note that this can also happen by turning the 3373 CODE_LABEL into a NOTE. */ 3374 /* ??? This seems completely and utterly wrong. Certainly it's 3375 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper 3376 functioning even with INSN_DELETED_P and friends. */ 3377 3378 tmp = x; 3379 switch (GET_CODE (x)) 3380 { 3381 case CONST: 3382 if (GET_CODE (XEXP (x, 0)) != PLUS 3383 || GET_CODE (XEXP (XEXP (x, 0), 0)) != LABEL_REF) 3384 break; 3385 tmp = XEXP (XEXP (x, 0), 0); 3386 /* FALLTHRU */ 3387 3388 case LABEL_REF: 3389 tmp = XEXP (x, 0); 3390 gcc_assert (!INSN_DELETED_P (tmp)); 3391 gcc_assert (!NOTE_P (tmp) 3392 || NOTE_LINE_NUMBER (tmp) != NOTE_INSN_DELETED); 3393 break; 3394 3395 default: 3396 break; 3397 } 3398 3399#ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY 3400 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode, 3401 align, desc->labelno, done); 3402#endif 3403 3404 assemble_align (align); 3405 3406 /* Output the label. */ 3407 targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno); 3408 3409 /* Output the data. */ 3410 output_constant_pool_2 (desc->mode, x, align); 3411 3412 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS 3413 sections have proper size. */ 3414 if (align > GET_MODE_BITSIZE (desc->mode) 3415 && in_section 3416 && (in_section->common.flags & SECTION_MERGE)) 3417 assemble_align (align); 3418 3419#ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY 3420 done: 3421#endif 3422 return; 3423} 3424 3425/* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers 3426 to as used. Emit referenced deferred strings. This function can 3427 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */ 3428 3429static int 3430mark_constant (rtx *current_rtx, void *data ATTRIBUTE_UNUSED) 3431{ 3432 rtx x = *current_rtx; 3433 3434 if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF) 3435 return 0; 3436 3437 if (CONSTANT_POOL_ADDRESS_P (x)) 3438 { 3439 struct constant_descriptor_rtx *desc = SYMBOL_REF_CONSTANT (x); 3440 if (desc->mark == 0) 3441 { 3442 desc->mark = 1; 3443 for_each_rtx (&desc->constant, mark_constant, NULL); 3444 } 3445 } 3446 else if (TREE_CONSTANT_POOL_ADDRESS_P (x)) 3447 { 3448 tree exp = SYMBOL_REF_DECL (x); 3449 if (!TREE_ASM_WRITTEN (exp)) 3450 { 3451 n_deferred_constants--; 3452 output_constant_def_contents (x); 3453 } 3454 } 3455 3456 return -1; 3457} 3458 3459/* Look through appropriate parts of INSN, marking all entries in the 3460 constant pool which are actually being used. Entries that are only 3461 referenced by other constants are also marked as used. Emit 3462 deferred strings that are used. */ 3463 3464static void 3465mark_constants (rtx insn) 3466{ 3467 if (!INSN_P (insn)) 3468 return; 3469 3470 /* Insns may appear inside a SEQUENCE. Only check the patterns of 3471 insns, not any notes that may be attached. We don't want to mark 3472 a constant just because it happens to appear in a REG_EQUIV note. */ 3473 if (GET_CODE (PATTERN (insn)) == SEQUENCE) 3474 { 3475 rtx seq = PATTERN (insn); 3476 int i, n = XVECLEN (seq, 0); 3477 for (i = 0; i < n; ++i) 3478 { 3479 rtx subinsn = XVECEXP (seq, 0, i); 3480 if (INSN_P (subinsn)) 3481 for_each_rtx (&PATTERN (subinsn), mark_constant, NULL); 3482 } 3483 } 3484 else 3485 for_each_rtx (&PATTERN (insn), mark_constant, NULL); 3486} 3487 3488/* Look through the instructions for this function, and mark all the 3489 entries in POOL which are actually being used. Emit deferred constants 3490 which have indeed been used. */ 3491 3492static void 3493mark_constant_pool (void) 3494{ 3495 rtx insn, link; 3496 3497 if (!current_function_uses_const_pool && n_deferred_constants == 0) 3498 return; 3499 3500 for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) 3501 mark_constants (insn); 3502 3503 for (link = current_function_epilogue_delay_list; 3504 link; 3505 link = XEXP (link, 1)) 3506 mark_constants (XEXP (link, 0)); 3507} 3508 3509/* Write all the constants in POOL. */ 3510 3511static void 3512output_constant_pool_contents (struct rtx_constant_pool *pool) 3513{ 3514 struct constant_descriptor_rtx *desc; 3515 3516 for (desc = pool->first; desc ; desc = desc->next) 3517 if (desc->mark) 3518 { 3519 /* If the constant is part of an object_block, make sure that 3520 the constant has been positioned within its block, but do not 3521 write out its definition yet. output_object_blocks will do 3522 that later. */ 3523 if (SYMBOL_REF_HAS_BLOCK_INFO_P (desc->sym) 3524 && SYMBOL_REF_BLOCK (desc->sym)) 3525 place_block_symbol (desc->sym); 3526 else 3527 { 3528 switch_to_section (targetm.asm_out.select_rtx_section 3529 (desc->mode, desc->constant, desc->align)); 3530 output_constant_pool_1 (desc, desc->align); 3531 } 3532 } 3533} 3534 3535/* Mark all constants that are used in the current function, then write 3536 out the function's private constant pool. */ 3537 3538static void 3539output_constant_pool (const char *fnname ATTRIBUTE_UNUSED, 3540 tree fndecl ATTRIBUTE_UNUSED) 3541{ 3542 struct rtx_constant_pool *pool = cfun->varasm->pool; 3543 3544 /* It is possible for gcc to call force_const_mem and then to later 3545 discard the instructions which refer to the constant. In such a 3546 case we do not need to output the constant. */ 3547 mark_constant_pool (); 3548 3549#ifdef ASM_OUTPUT_POOL_PROLOGUE 3550 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset); 3551#endif 3552 3553 output_constant_pool_contents (pool); 3554 3555#ifdef ASM_OUTPUT_POOL_EPILOGUE 3556 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset); 3557#endif 3558} 3559 3560/* Write the contents of the shared constant pool. */ 3561 3562void 3563output_shared_constant_pool (void) 3564{ 3565 output_constant_pool_contents (shared_constant_pool); 3566} 3567 3568/* Determine what kind of relocations EXP may need. */ 3569 3570int 3571compute_reloc_for_constant (tree exp) 3572{ 3573 int reloc = 0, reloc2; 3574 tree tem; 3575 3576 /* Give the front-end a chance to convert VALUE to something that 3577 looks more like a constant to the back-end. */ 3578 exp = lang_hooks.expand_constant (exp); 3579 3580 switch (TREE_CODE (exp)) 3581 { 3582 case ADDR_EXPR: 3583 case FDESC_EXPR: 3584 /* Go inside any operations that get_inner_reference can handle and see 3585 if what's inside is a constant: no need to do anything here for 3586 addresses of variables or functions. */ 3587 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem); 3588 tem = TREE_OPERAND (tem, 0)) 3589 ; 3590 3591 if (TREE_PUBLIC (tem)) 3592 reloc |= 2; 3593 else 3594 reloc |= 1; 3595 break; 3596 3597 case PLUS_EXPR: 3598 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0)); 3599 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1)); 3600 break; 3601 3602 case MINUS_EXPR: 3603 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0)); 3604 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1)); 3605 /* The difference of two local labels is computable at link time. */ 3606 if (reloc == 1 && reloc2 == 1) 3607 reloc = 0; 3608 else 3609 reloc |= reloc2; 3610 break; 3611 3612 case NOP_EXPR: 3613 case CONVERT_EXPR: 3614 case NON_LVALUE_EXPR: 3615 case VIEW_CONVERT_EXPR: 3616 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0)); 3617 break; 3618 3619 case CONSTRUCTOR: 3620 { 3621 unsigned HOST_WIDE_INT idx; 3622 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem) 3623 if (tem != 0) 3624 reloc |= compute_reloc_for_constant (tem); 3625 } 3626 break; 3627 3628 default: 3629 break; 3630 } 3631 return reloc; 3632} 3633 3634/* Find all the constants whose addresses are referenced inside of EXP, 3635 and make sure assembler code with a label has been output for each one. 3636 Indicate whether an ADDR_EXPR has been encountered. */ 3637 3638static void 3639output_addressed_constants (tree exp) 3640{ 3641 tree tem; 3642 3643 /* Give the front-end a chance to convert VALUE to something that 3644 looks more like a constant to the back-end. */ 3645 exp = lang_hooks.expand_constant (exp); 3646 3647 switch (TREE_CODE (exp)) 3648 { 3649 case ADDR_EXPR: 3650 case FDESC_EXPR: 3651 /* Go inside any operations that get_inner_reference can handle and see 3652 if what's inside is a constant: no need to do anything here for 3653 addresses of variables or functions. */ 3654 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem); 3655 tem = TREE_OPERAND (tem, 0)) 3656 ; 3657 3658 /* If we have an initialized CONST_DECL, retrieve the initializer. */ 3659 if (TREE_CODE (tem) == CONST_DECL && DECL_INITIAL (tem)) 3660 tem = DECL_INITIAL (tem); 3661 3662 if (CONSTANT_CLASS_P (tem) || TREE_CODE (tem) == CONSTRUCTOR) 3663 output_constant_def (tem, 0); 3664 break; 3665 3666 case PLUS_EXPR: 3667 case MINUS_EXPR: 3668 output_addressed_constants (TREE_OPERAND (exp, 1)); 3669 /* Fall through. */ 3670 3671 case NOP_EXPR: 3672 case CONVERT_EXPR: 3673 case NON_LVALUE_EXPR: 3674 case VIEW_CONVERT_EXPR: 3675 output_addressed_constants (TREE_OPERAND (exp, 0)); 3676 break; 3677 3678 case CONSTRUCTOR: 3679 { 3680 unsigned HOST_WIDE_INT idx; 3681 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem) 3682 if (tem != 0) 3683 output_addressed_constants (tem); 3684 } 3685 break; 3686 3687 default: 3688 break; 3689 } 3690} 3691 3692/* Whether a constructor CTOR is a valid static constant initializer if all 3693 its elements are. This used to be internal to initializer_constant_valid_p 3694 and has been exposed to let other functions like categorize_ctor_elements 3695 evaluate the property while walking a constructor for other purposes. */ 3696 3697bool 3698constructor_static_from_elts_p (tree ctor) 3699{ 3700 return (TREE_CONSTANT (ctor) 3701 && (TREE_CODE (TREE_TYPE (ctor)) == UNION_TYPE 3702 || TREE_CODE (TREE_TYPE (ctor)) == RECORD_TYPE) 3703 && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (ctor))); 3704} 3705 3706/* Return nonzero if VALUE is a valid constant-valued expression 3707 for use in initializing a static variable; one that can be an 3708 element of a "constant" initializer. 3709 3710 Return null_pointer_node if the value is absolute; 3711 if it is relocatable, return the variable that determines the relocation. 3712 We assume that VALUE has been folded as much as possible; 3713 therefore, we do not need to check for such things as 3714 arithmetic-combinations of integers. */ 3715 3716tree 3717initializer_constant_valid_p (tree value, tree endtype) 3718{ 3719 /* Give the front-end a chance to convert VALUE to something that 3720 looks more like a constant to the back-end. */ 3721 value = lang_hooks.expand_constant (value); 3722 3723 switch (TREE_CODE (value)) 3724 { 3725 case CONSTRUCTOR: 3726 if (constructor_static_from_elts_p (value)) 3727 { 3728 unsigned HOST_WIDE_INT idx; 3729 tree elt; 3730 bool absolute = true; 3731 3732 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt) 3733 { 3734 tree reloc; 3735 reloc = initializer_constant_valid_p (elt, TREE_TYPE (elt)); 3736 if (!reloc) 3737 return NULL_TREE; 3738 if (reloc != null_pointer_node) 3739 absolute = false; 3740 } 3741 /* For a non-absolute relocation, there is no single 3742 variable that can be "the variable that determines the 3743 relocation." */ 3744 return absolute ? null_pointer_node : error_mark_node; 3745 } 3746 3747 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE; 3748 3749 case INTEGER_CST: 3750 case VECTOR_CST: 3751 case REAL_CST: 3752 case STRING_CST: 3753 case COMPLEX_CST: 3754 return null_pointer_node; 3755 3756 case ADDR_EXPR: 3757 case FDESC_EXPR: 3758 value = staticp (TREE_OPERAND (value, 0)); 3759 if (value) 3760 { 3761 /* "&(*a).f" is like unto pointer arithmetic. If "a" turns out to 3762 be a constant, this is old-skool offsetof-like nonsense. */ 3763 if (TREE_CODE (value) == INDIRECT_REF 3764 && TREE_CONSTANT (TREE_OPERAND (value, 0))) 3765 return null_pointer_node; 3766 /* Taking the address of a nested function involves a trampoline. */ 3767 if (TREE_CODE (value) == FUNCTION_DECL 3768 && ((decl_function_context (value) 3769 && !DECL_NO_STATIC_CHAIN (value)) 3770 || DECL_DLLIMPORT_P (value))) 3771 return NULL_TREE; 3772 /* "&{...}" requires a temporary to hold the constructed 3773 object. */ 3774 if (TREE_CODE (value) == CONSTRUCTOR) 3775 return NULL_TREE; 3776 } 3777 return value; 3778 3779 case VIEW_CONVERT_EXPR: 3780 case NON_LVALUE_EXPR: 3781 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype); 3782 3783 case CONVERT_EXPR: 3784 case NOP_EXPR: 3785 { 3786 tree src; 3787 tree src_type; 3788 tree dest_type; 3789 3790 src = TREE_OPERAND (value, 0); 3791 src_type = TREE_TYPE (src); 3792 dest_type = TREE_TYPE (value); 3793 3794 /* Allow conversions between pointer types, floating-point 3795 types, and offset types. */ 3796 if ((POINTER_TYPE_P (dest_type) && POINTER_TYPE_P (src_type)) 3797 || (FLOAT_TYPE_P (dest_type) && FLOAT_TYPE_P (src_type)) 3798 || (TREE_CODE (dest_type) == OFFSET_TYPE 3799 && TREE_CODE (src_type) == OFFSET_TYPE)) 3800 return initializer_constant_valid_p (src, endtype); 3801 3802 /* Allow length-preserving conversions between integer types. */ 3803 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type) 3804 && (TYPE_PRECISION (dest_type) == TYPE_PRECISION (src_type))) 3805 return initializer_constant_valid_p (src, endtype); 3806 3807 /* Allow conversions between other integer types only if 3808 explicit value. */ 3809 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type)) 3810 { 3811 tree inner = initializer_constant_valid_p (src, endtype); 3812 if (inner == null_pointer_node) 3813 return null_pointer_node; 3814 break; 3815 } 3816 3817 /* Allow (int) &foo provided int is as wide as a pointer. */ 3818 if (INTEGRAL_TYPE_P (dest_type) && POINTER_TYPE_P (src_type) 3819 && (TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type))) 3820 return initializer_constant_valid_p (src, endtype); 3821 3822 /* Likewise conversions from int to pointers, but also allow 3823 conversions from 0. */ 3824 if ((POINTER_TYPE_P (dest_type) 3825 || TREE_CODE (dest_type) == OFFSET_TYPE) 3826 && INTEGRAL_TYPE_P (src_type)) 3827 { 3828 if (TREE_CODE (src) == INTEGER_CST 3829 && TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type)) 3830 return null_pointer_node; 3831 if (integer_zerop (src)) 3832 return null_pointer_node; 3833 else if (TYPE_PRECISION (dest_type) <= TYPE_PRECISION (src_type)) 3834 return initializer_constant_valid_p (src, endtype); 3835 } 3836 3837 /* Allow conversions to struct or union types if the value 3838 inside is okay. */ 3839 if (TREE_CODE (dest_type) == RECORD_TYPE 3840 || TREE_CODE (dest_type) == UNION_TYPE) 3841 return initializer_constant_valid_p (src, endtype); 3842 } 3843 break; 3844 3845 case PLUS_EXPR: 3846 if (! INTEGRAL_TYPE_P (endtype) 3847 || TYPE_PRECISION (endtype) >= POINTER_SIZE) 3848 { 3849 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0), 3850 endtype); 3851 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1), 3852 endtype); 3853 /* If either term is absolute, use the other terms relocation. */ 3854 if (valid0 == null_pointer_node) 3855 return valid1; 3856 if (valid1 == null_pointer_node) 3857 return valid0; 3858 } 3859 break; 3860 3861 case MINUS_EXPR: 3862 if (! INTEGRAL_TYPE_P (endtype) 3863 || TYPE_PRECISION (endtype) >= POINTER_SIZE) 3864 { 3865 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0), 3866 endtype); 3867 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1), 3868 endtype); 3869 /* Win if second argument is absolute. */ 3870 if (valid1 == null_pointer_node) 3871 return valid0; 3872 /* Win if both arguments have the same relocation. 3873 Then the value is absolute. */ 3874 if (valid0 == valid1 && valid0 != 0) 3875 return null_pointer_node; 3876 3877 /* Since GCC guarantees that string constants are unique in the 3878 generated code, a subtraction between two copies of the same 3879 constant string is absolute. */ 3880 if (valid0 && TREE_CODE (valid0) == STRING_CST 3881 && valid1 && TREE_CODE (valid1) == STRING_CST 3882 && operand_equal_p (valid0, valid1, 1)) 3883 return null_pointer_node; 3884 } 3885 3886 /* Support narrowing differences. */ 3887 if (INTEGRAL_TYPE_P (endtype)) 3888 { 3889 tree op0, op1; 3890 3891 op0 = TREE_OPERAND (value, 0); 3892 op1 = TREE_OPERAND (value, 1); 3893 3894 /* Like STRIP_NOPS except allow the operand mode to widen. 3895 This works around a feature of fold that simplifies 3896 (int)(p1 - p2) to ((int)p1 - (int)p2) under the theory 3897 that the narrower operation is cheaper. */ 3898 3899 while (TREE_CODE (op0) == NOP_EXPR 3900 || TREE_CODE (op0) == CONVERT_EXPR 3901 || TREE_CODE (op0) == NON_LVALUE_EXPR) 3902 { 3903 tree inner = TREE_OPERAND (op0, 0); 3904 if (inner == error_mark_node 3905 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner))) 3906 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))) 3907 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner))))) 3908 break; 3909 op0 = inner; 3910 } 3911 3912 while (TREE_CODE (op1) == NOP_EXPR 3913 || TREE_CODE (op1) == CONVERT_EXPR 3914 || TREE_CODE (op1) == NON_LVALUE_EXPR) 3915 { 3916 tree inner = TREE_OPERAND (op1, 0); 3917 if (inner == error_mark_node 3918 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner))) 3919 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1))) 3920 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner))))) 3921 break; 3922 op1 = inner; 3923 } 3924 3925 op0 = initializer_constant_valid_p (op0, endtype); 3926 op1 = initializer_constant_valid_p (op1, endtype); 3927 3928 /* Both initializers must be known. */ 3929 if (op0 && op1) 3930 { 3931 if (op0 == op1) 3932 return null_pointer_node; 3933 3934 /* Support differences between labels. */ 3935 if (TREE_CODE (op0) == LABEL_DECL 3936 && TREE_CODE (op1) == LABEL_DECL) 3937 return null_pointer_node; 3938 3939 if (TREE_CODE (op0) == STRING_CST 3940 && TREE_CODE (op1) == STRING_CST 3941 && operand_equal_p (op0, op1, 1)) 3942 return null_pointer_node; 3943 } 3944 } 3945 break; 3946 3947 default: 3948 break; 3949 } 3950 3951 return 0; 3952} 3953 3954/* Output assembler code for constant EXP to FILE, with no label. 3955 This includes the pseudo-op such as ".int" or ".byte", and a newline. 3956 Assumes output_addressed_constants has been done on EXP already. 3957 3958 Generate exactly SIZE bytes of assembler data, padding at the end 3959 with zeros if necessary. SIZE must always be specified. 3960 3961 SIZE is important for structure constructors, 3962 since trailing members may have been omitted from the constructor. 3963 It is also important for initialization of arrays from string constants 3964 since the full length of the string constant might not be wanted. 3965 It is also needed for initialization of unions, where the initializer's 3966 type is just one member, and that may not be as long as the union. 3967 3968 There a case in which we would fail to output exactly SIZE bytes: 3969 for a structure constructor that wants to produce more than SIZE bytes. 3970 But such constructors will never be generated for any possible input. 3971 3972 ALIGN is the alignment of the data in bits. */ 3973 3974void 3975output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align) 3976{ 3977 enum tree_code code; 3978 unsigned HOST_WIDE_INT thissize; 3979 3980 /* Some front-ends use constants other than the standard language-independent 3981 varieties, but which may still be output directly. Give the front-end a 3982 chance to convert EXP to a language-independent representation. */ 3983 exp = lang_hooks.expand_constant (exp); 3984 3985 if (size == 0 || flag_syntax_only) 3986 return; 3987 3988 /* See if we're trying to initialize a pointer in a non-default mode 3989 to the address of some declaration somewhere. If the target says 3990 the mode is valid for pointers, assume the target has a way of 3991 resolving it. */ 3992 if (TREE_CODE (exp) == NOP_EXPR 3993 && POINTER_TYPE_P (TREE_TYPE (exp)) 3994 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp)))) 3995 { 3996 tree saved_type = TREE_TYPE (exp); 3997 3998 /* Peel off any intermediate conversions-to-pointer for valid 3999 pointer modes. */ 4000 while (TREE_CODE (exp) == NOP_EXPR 4001 && POINTER_TYPE_P (TREE_TYPE (exp)) 4002 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp)))) 4003 exp = TREE_OPERAND (exp, 0); 4004 4005 /* If what we're left with is the address of something, we can 4006 convert the address to the final type and output it that 4007 way. */ 4008 if (TREE_CODE (exp) == ADDR_EXPR) 4009 exp = build1 (ADDR_EXPR, saved_type, TREE_OPERAND (exp, 0)); 4010 /* Likewise for constant ints. */ 4011 else if (TREE_CODE (exp) == INTEGER_CST) 4012 exp = build_int_cst_wide (saved_type, TREE_INT_CST_LOW (exp), 4013 TREE_INT_CST_HIGH (exp)); 4014 4015 } 4016 4017 /* Eliminate any conversions since we'll be outputting the underlying 4018 constant. */ 4019 while (TREE_CODE (exp) == NOP_EXPR || TREE_CODE (exp) == CONVERT_EXPR 4020 || TREE_CODE (exp) == NON_LVALUE_EXPR 4021 || TREE_CODE (exp) == VIEW_CONVERT_EXPR) 4022 { 4023 HOST_WIDE_INT type_size = int_size_in_bytes (TREE_TYPE (exp)); 4024 HOST_WIDE_INT op_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (exp, 0))); 4025 4026 /* Make sure eliminating the conversion is really a no-op, except with 4027 VIEW_CONVERT_EXPRs to allow for wild Ada unchecked conversions and 4028 union types to allow for Ada unchecked unions. */ 4029 if (type_size > op_size 4030 && TREE_CODE (exp) != VIEW_CONVERT_EXPR 4031 && TREE_CODE (TREE_TYPE (exp)) != UNION_TYPE) 4032 /* Keep the conversion. */ 4033 break; 4034 else 4035 exp = TREE_OPERAND (exp, 0); 4036 } 4037 4038 code = TREE_CODE (TREE_TYPE (exp)); 4039 thissize = int_size_in_bytes (TREE_TYPE (exp)); 4040 4041 /* Give the front end another chance to expand constants. */ 4042 exp = lang_hooks.expand_constant (exp); 4043 4044 /* Allow a constructor with no elements for any data type. 4045 This means to fill the space with zeros. */ 4046 if (TREE_CODE (exp) == CONSTRUCTOR 4047 && VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (exp))) 4048 { 4049 assemble_zeros (size); 4050 return; 4051 } 4052 4053 if (TREE_CODE (exp) == FDESC_EXPR) 4054 { 4055#ifdef ASM_OUTPUT_FDESC 4056 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0); 4057 tree decl = TREE_OPERAND (exp, 0); 4058 ASM_OUTPUT_FDESC (asm_out_file, decl, part); 4059#else 4060 gcc_unreachable (); 4061#endif 4062 return; 4063 } 4064 4065 /* Now output the underlying data. If we've handling the padding, return. 4066 Otherwise, break and ensure SIZE is the size written. */ 4067 switch (code) 4068 { 4069 case BOOLEAN_TYPE: 4070 case INTEGER_TYPE: 4071 case ENUMERAL_TYPE: 4072 case POINTER_TYPE: 4073 case REFERENCE_TYPE: 4074 case OFFSET_TYPE: 4075 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode, 4076 EXPAND_INITIALIZER), 4077 MIN (size, thissize), align, 0)) 4078 error ("initializer for integer value is too complicated"); 4079 break; 4080 4081 case REAL_TYPE: 4082 if (TREE_CODE (exp) != REAL_CST) 4083 error ("initializer for floating value is not a floating constant"); 4084 4085 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align); 4086 break; 4087 4088 case COMPLEX_TYPE: 4089 output_constant (TREE_REALPART (exp), thissize / 2, align); 4090 output_constant (TREE_IMAGPART (exp), thissize / 2, 4091 min_align (align, BITS_PER_UNIT * (thissize / 2))); 4092 break; 4093 4094 case ARRAY_TYPE: 4095 case VECTOR_TYPE: 4096 switch (TREE_CODE (exp)) 4097 { 4098 case CONSTRUCTOR: 4099 output_constructor (exp, size, align); 4100 return; 4101 case STRING_CST: 4102 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp), 4103 size); 4104 assemble_string (TREE_STRING_POINTER (exp), thissize); 4105 break; 4106 4107 case VECTOR_CST: 4108 { 4109 int elt_size; 4110 tree link; 4111 unsigned int nalign; 4112 enum machine_mode inner; 4113 4114 inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp))); 4115 nalign = MIN (align, GET_MODE_ALIGNMENT (inner)); 4116 4117 elt_size = GET_MODE_SIZE (inner); 4118 4119 link = TREE_VECTOR_CST_ELTS (exp); 4120 output_constant (TREE_VALUE (link), elt_size, align); 4121 thissize = elt_size; 4122 while ((link = TREE_CHAIN (link)) != NULL) 4123 { 4124 output_constant (TREE_VALUE (link), elt_size, nalign); 4125 thissize += elt_size; 4126 } 4127 break; 4128 } 4129 default: 4130 gcc_unreachable (); 4131 } 4132 break; 4133 4134 case RECORD_TYPE: 4135 case UNION_TYPE: 4136 gcc_assert (TREE_CODE (exp) == CONSTRUCTOR); 4137 output_constructor (exp, size, align); 4138 return; 4139 4140 case ERROR_MARK: 4141 return; 4142 4143 default: 4144 gcc_unreachable (); 4145 } 4146 4147 if (size > thissize) 4148 assemble_zeros (size - thissize); 4149} 4150 4151 4152/* Subroutine of output_constructor, used for computing the size of 4153 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array 4154 type with an unspecified upper bound. */ 4155 4156static unsigned HOST_WIDE_INT 4157array_size_for_constructor (tree val) 4158{ 4159 tree max_index, i; 4160 unsigned HOST_WIDE_INT cnt; 4161 tree index, value, tmp; 4162 4163 /* This code used to attempt to handle string constants that are not 4164 arrays of single-bytes, but nothing else does, so there's no point in 4165 doing it here. */ 4166 if (TREE_CODE (val) == STRING_CST) 4167 return TREE_STRING_LENGTH (val); 4168 4169 max_index = NULL_TREE; 4170 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (val), cnt, index, value) 4171 { 4172 if (TREE_CODE (index) == RANGE_EXPR) 4173 index = TREE_OPERAND (index, 1); 4174 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index)) 4175 max_index = index; 4176 } 4177 4178 if (max_index == NULL_TREE) 4179 return 0; 4180 4181 /* Compute the total number of array elements. */ 4182 tmp = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val))); 4183 i = size_binop (MINUS_EXPR, fold_convert (sizetype, max_index), 4184 fold_convert (sizetype, tmp)); 4185 i = size_binop (PLUS_EXPR, i, build_int_cst (sizetype, 1)); 4186 4187 /* Multiply by the array element unit size to find number of bytes. */ 4188 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val)))); 4189 4190 return tree_low_cst (i, 1); 4191} 4192 4193/* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants). 4194 Generate at least SIZE bytes, padding if necessary. */ 4195 4196static void 4197output_constructor (tree exp, unsigned HOST_WIDE_INT size, 4198 unsigned int align) 4199{ 4200 tree type = TREE_TYPE (exp); 4201 tree field = 0; 4202 tree min_index = 0; 4203 /* Number of bytes output or skipped so far. 4204 In other words, current position within the constructor. */ 4205 HOST_WIDE_INT total_bytes = 0; 4206 /* Nonzero means BYTE contains part of a byte, to be output. */ 4207 int byte_buffer_in_use = 0; 4208 int byte = 0; 4209 unsigned HOST_WIDE_INT cnt; 4210 constructor_elt *ce; 4211 4212 gcc_assert (HOST_BITS_PER_WIDE_INT >= BITS_PER_UNIT); 4213 4214 if (TREE_CODE (type) == RECORD_TYPE) 4215 field = TYPE_FIELDS (type); 4216 4217 if (TREE_CODE (type) == ARRAY_TYPE 4218 && TYPE_DOMAIN (type) != 0) 4219 min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (type)); 4220 4221 /* As LINK goes through the elements of the constant, 4222 FIELD goes through the structure fields, if the constant is a structure. 4223 if the constant is a union, then we override this, 4224 by getting the field from the TREE_LIST element. 4225 But the constant could also be an array. Then FIELD is zero. 4226 4227 There is always a maximum of one element in the chain LINK for unions 4228 (even if the initializer in a source program incorrectly contains 4229 more one). */ 4230 for (cnt = 0; 4231 VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (exp), cnt, ce); 4232 cnt++, field = field ? TREE_CHAIN (field) : 0) 4233 { 4234 tree val = ce->value; 4235 tree index = 0; 4236 4237 /* The element in a union constructor specifies the proper field 4238 or index. */ 4239 if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE 4240 || TREE_CODE (type) == QUAL_UNION_TYPE) 4241 && ce->index != 0) 4242 field = ce->index; 4243 4244 else if (TREE_CODE (type) == ARRAY_TYPE) 4245 index = ce->index; 4246 4247#ifdef ASM_COMMENT_START 4248 if (field && flag_verbose_asm) 4249 fprintf (asm_out_file, "%s %s:\n", 4250 ASM_COMMENT_START, 4251 DECL_NAME (field) 4252 ? IDENTIFIER_POINTER (DECL_NAME (field)) 4253 : "<anonymous>"); 4254#endif 4255 4256 /* Eliminate the marker that makes a cast not be an lvalue. */ 4257 if (val != 0) 4258 STRIP_NOPS (val); 4259 4260 if (index && TREE_CODE (index) == RANGE_EXPR) 4261 { 4262 unsigned HOST_WIDE_INT fieldsize 4263 = int_size_in_bytes (TREE_TYPE (type)); 4264 HOST_WIDE_INT lo_index = tree_low_cst (TREE_OPERAND (index, 0), 0); 4265 HOST_WIDE_INT hi_index = tree_low_cst (TREE_OPERAND (index, 1), 0); 4266 HOST_WIDE_INT index; 4267 unsigned int align2 = min_align (align, fieldsize * BITS_PER_UNIT); 4268 4269 for (index = lo_index; index <= hi_index; index++) 4270 { 4271 /* Output the element's initial value. */ 4272 if (val == 0) 4273 assemble_zeros (fieldsize); 4274 else 4275 output_constant (val, fieldsize, align2); 4276 4277 /* Count its size. */ 4278 total_bytes += fieldsize; 4279 } 4280 } 4281 else if (field == 0 || !DECL_BIT_FIELD (field)) 4282 { 4283 /* An element that is not a bit-field. */ 4284 4285 unsigned HOST_WIDE_INT fieldsize; 4286 /* Since this structure is static, 4287 we know the positions are constant. */ 4288 HOST_WIDE_INT pos = field ? int_byte_position (field) : 0; 4289 unsigned int align2; 4290 4291 if (index != 0) 4292 pos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (val)), 1) 4293 * (tree_low_cst (index, 0) - tree_low_cst (min_index, 0))); 4294 4295 /* Output any buffered-up bit-fields preceding this element. */ 4296 if (byte_buffer_in_use) 4297 { 4298 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1); 4299 total_bytes++; 4300 byte_buffer_in_use = 0; 4301 } 4302 4303 /* Advance to offset of this element. 4304 Note no alignment needed in an array, since that is guaranteed 4305 if each element has the proper size. */ 4306 if ((field != 0 || index != 0) && pos != total_bytes) 4307 { 4308 gcc_assert (pos >= total_bytes); 4309 assemble_zeros (pos - total_bytes); 4310 total_bytes = pos; 4311 } 4312 4313 /* Find the alignment of this element. */ 4314 align2 = min_align (align, BITS_PER_UNIT * pos); 4315 4316 /* Determine size this element should occupy. */ 4317 if (field) 4318 { 4319 fieldsize = 0; 4320 4321 /* If this is an array with an unspecified upper bound, 4322 the initializer determines the size. */ 4323 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL, 4324 but we cannot do this until the deprecated support for 4325 initializing zero-length array members is removed. */ 4326 if (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE 4327 && TYPE_DOMAIN (TREE_TYPE (field)) 4328 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (field)))) 4329 { 4330 fieldsize = array_size_for_constructor (val); 4331 /* Given a non-empty initialization, this field had 4332 better be last. */ 4333 gcc_assert (!fieldsize || !TREE_CHAIN (field)); 4334 } 4335 else if (DECL_SIZE_UNIT (field)) 4336 { 4337 /* ??? This can't be right. If the decl size overflows 4338 a host integer we will silently emit no data. */ 4339 if (host_integerp (DECL_SIZE_UNIT (field), 1)) 4340 fieldsize = tree_low_cst (DECL_SIZE_UNIT (field), 1); 4341 } 4342 } 4343 else 4344 fieldsize = int_size_in_bytes (TREE_TYPE (type)); 4345 4346 /* Output the element's initial value. */ 4347 if (val == 0) 4348 assemble_zeros (fieldsize); 4349 else 4350 output_constant (val, fieldsize, align2); 4351 4352 /* Count its size. */ 4353 total_bytes += fieldsize; 4354 } 4355 else if (val != 0 && TREE_CODE (val) != INTEGER_CST) 4356 error ("invalid initial value for member %qs", 4357 IDENTIFIER_POINTER (DECL_NAME (field))); 4358 else 4359 { 4360 /* Element that is a bit-field. */ 4361 4362 HOST_WIDE_INT next_offset = int_bit_position (field); 4363 HOST_WIDE_INT end_offset 4364 = (next_offset + tree_low_cst (DECL_SIZE (field), 1)); 4365 4366 if (val == 0) 4367 val = integer_zero_node; 4368 4369 /* If this field does not start in this (or, next) byte, 4370 skip some bytes. */ 4371 if (next_offset / BITS_PER_UNIT != total_bytes) 4372 { 4373 /* Output remnant of any bit field in previous bytes. */ 4374 if (byte_buffer_in_use) 4375 { 4376 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1); 4377 total_bytes++; 4378 byte_buffer_in_use = 0; 4379 } 4380 4381 /* If still not at proper byte, advance to there. */ 4382 if (next_offset / BITS_PER_UNIT != total_bytes) 4383 { 4384 gcc_assert (next_offset / BITS_PER_UNIT >= total_bytes); 4385 assemble_zeros (next_offset / BITS_PER_UNIT - total_bytes); 4386 total_bytes = next_offset / BITS_PER_UNIT; 4387 } 4388 } 4389 4390 if (! byte_buffer_in_use) 4391 byte = 0; 4392 4393 /* We must split the element into pieces that fall within 4394 separate bytes, and combine each byte with previous or 4395 following bit-fields. */ 4396 4397 /* next_offset is the offset n fbits from the beginning of 4398 the structure to the next bit of this element to be processed. 4399 end_offset is the offset of the first bit past the end of 4400 this element. */ 4401 while (next_offset < end_offset) 4402 { 4403 int this_time; 4404 int shift; 4405 HOST_WIDE_INT value; 4406 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT; 4407 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT; 4408 4409 /* Advance from byte to byte 4410 within this element when necessary. */ 4411 while (next_byte != total_bytes) 4412 { 4413 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1); 4414 total_bytes++; 4415 byte = 0; 4416 } 4417 4418 /* Number of bits we can process at once 4419 (all part of the same byte). */ 4420 this_time = MIN (end_offset - next_offset, 4421 BITS_PER_UNIT - next_bit); 4422 if (BYTES_BIG_ENDIAN) 4423 { 4424 /* On big-endian machine, take the most significant bits 4425 first (of the bits that are significant) 4426 and put them into bytes from the most significant end. */ 4427 shift = end_offset - next_offset - this_time; 4428 4429 /* Don't try to take a bunch of bits that cross 4430 the word boundary in the INTEGER_CST. We can 4431 only select bits from the LOW or HIGH part 4432 not from both. */ 4433 if (shift < HOST_BITS_PER_WIDE_INT 4434 && shift + this_time > HOST_BITS_PER_WIDE_INT) 4435 { 4436 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT; 4437 shift = HOST_BITS_PER_WIDE_INT; 4438 } 4439 4440 /* Now get the bits from the appropriate constant word. */ 4441 if (shift < HOST_BITS_PER_WIDE_INT) 4442 value = TREE_INT_CST_LOW (val); 4443 else 4444 { 4445 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT); 4446 value = TREE_INT_CST_HIGH (val); 4447 shift -= HOST_BITS_PER_WIDE_INT; 4448 } 4449 4450 /* Get the result. This works only when: 4451 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */ 4452 byte |= (((value >> shift) 4453 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1)) 4454 << (BITS_PER_UNIT - this_time - next_bit)); 4455 } 4456 else 4457 { 4458 /* On little-endian machines, 4459 take first the least significant bits of the value 4460 and pack them starting at the least significant 4461 bits of the bytes. */ 4462 shift = next_offset - int_bit_position (field); 4463 4464 /* Don't try to take a bunch of bits that cross 4465 the word boundary in the INTEGER_CST. We can 4466 only select bits from the LOW or HIGH part 4467 not from both. */ 4468 if (shift < HOST_BITS_PER_WIDE_INT 4469 && shift + this_time > HOST_BITS_PER_WIDE_INT) 4470 this_time = (HOST_BITS_PER_WIDE_INT - shift); 4471 4472 /* Now get the bits from the appropriate constant word. */ 4473 if (shift < HOST_BITS_PER_WIDE_INT) 4474 value = TREE_INT_CST_LOW (val); 4475 else 4476 { 4477 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT); 4478 value = TREE_INT_CST_HIGH (val); 4479 shift -= HOST_BITS_PER_WIDE_INT; 4480 } 4481 4482 /* Get the result. This works only when: 4483 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */ 4484 byte |= (((value >> shift) 4485 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1)) 4486 << next_bit); 4487 } 4488 4489 next_offset += this_time; 4490 byte_buffer_in_use = 1; 4491 } 4492 } 4493 } 4494 4495 if (byte_buffer_in_use) 4496 { 4497 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1); 4498 total_bytes++; 4499 } 4500 4501 if ((unsigned HOST_WIDE_INT)total_bytes < size) 4502 assemble_zeros (size - total_bytes); 4503} 4504 4505/* This TREE_LIST contains any weak symbol declarations waiting 4506 to be emitted. */ 4507static GTY(()) tree weak_decls; 4508 4509/* Mark DECL as weak. */ 4510 4511static void 4512mark_weak (tree decl) 4513{ 4514 DECL_WEAK (decl) = 1; 4515 4516 if (DECL_RTL_SET_P (decl) 4517 && MEM_P (DECL_RTL (decl)) 4518 && XEXP (DECL_RTL (decl), 0) 4519 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF) 4520 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1; 4521} 4522 4523/* Merge weak status between NEWDECL and OLDDECL. */ 4524 4525void 4526merge_weak (tree newdecl, tree olddecl) 4527{ 4528 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl)) 4529 { 4530 if (DECL_WEAK (newdecl) && SUPPORTS_WEAK) 4531 { 4532 tree *pwd; 4533 /* We put the NEWDECL on the weak_decls list at some point 4534 and OLDDECL as well. Keep just OLDDECL on the list. */ 4535 for (pwd = &weak_decls; *pwd; pwd = &TREE_CHAIN (*pwd)) 4536 if (TREE_VALUE (*pwd) == newdecl) 4537 { 4538 *pwd = TREE_CHAIN (*pwd); 4539 break; 4540 } 4541 } 4542 return; 4543 } 4544 4545 if (DECL_WEAK (newdecl)) 4546 { 4547 tree wd; 4548 4549 /* NEWDECL is weak, but OLDDECL is not. */ 4550 4551 /* If we already output the OLDDECL, we're in trouble; we can't 4552 go back and make it weak. This error cannot caught in 4553 declare_weak because the NEWDECL and OLDDECL was not yet 4554 been merged; therefore, TREE_ASM_WRITTEN was not set. */ 4555 if (TREE_ASM_WRITTEN (olddecl)) 4556 error ("weak declaration of %q+D must precede definition", 4557 newdecl); 4558 4559 /* If we've already generated rtl referencing OLDDECL, we may 4560 have done so in a way that will not function properly with 4561 a weak symbol. */ 4562 else if (TREE_USED (olddecl) 4563 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl))) 4564 warning (0, "weak declaration of %q+D after first use results " 4565 "in unspecified behavior", newdecl); 4566 4567 if (SUPPORTS_WEAK) 4568 { 4569 /* We put the NEWDECL on the weak_decls list at some point. 4570 Replace it with the OLDDECL. */ 4571 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd)) 4572 if (TREE_VALUE (wd) == newdecl) 4573 { 4574 TREE_VALUE (wd) = olddecl; 4575 break; 4576 } 4577 /* We may not find the entry on the list. If NEWDECL is a 4578 weak alias, then we will have already called 4579 globalize_decl to remove the entry; in that case, we do 4580 not need to do anything. */ 4581 } 4582 4583 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */ 4584 mark_weak (olddecl); 4585 } 4586 else 4587 /* OLDDECL was weak, but NEWDECL was not explicitly marked as 4588 weak. Just update NEWDECL to indicate that it's weak too. */ 4589 mark_weak (newdecl); 4590} 4591 4592/* Declare DECL to be a weak symbol. */ 4593 4594void 4595declare_weak (tree decl) 4596{ 4597 if (! TREE_PUBLIC (decl)) 4598 error ("weak declaration of %q+D must be public", decl); 4599 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl)) 4600 error ("weak declaration of %q+D must precede definition", decl); 4601 else if (SUPPORTS_WEAK) 4602 { 4603 if (! DECL_WEAK (decl)) 4604 weak_decls = tree_cons (NULL, decl, weak_decls); 4605 } 4606 else 4607 warning (0, "weak declaration of %q+D not supported", decl); 4608 4609 mark_weak (decl); 4610} 4611 4612static void 4613weak_finish_1 (tree decl) 4614{ 4615#if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL) 4616 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)); 4617#endif 4618 4619 if (! TREE_USED (decl)) 4620 return; 4621 4622#ifdef ASM_WEAKEN_DECL 4623 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL); 4624#else 4625#ifdef ASM_WEAKEN_LABEL 4626 ASM_WEAKEN_LABEL (asm_out_file, name); 4627#else 4628#ifdef ASM_OUTPUT_WEAK_ALIAS 4629 { 4630 static bool warn_once = 0; 4631 if (! warn_once) 4632 { 4633 warning (0, "only weak aliases are supported in this configuration"); 4634 warn_once = 1; 4635 } 4636 return; 4637 } 4638#endif 4639#endif 4640#endif 4641} 4642 4643/* This TREE_LIST contains weakref targets. */ 4644 4645static GTY(()) tree weakref_targets; 4646 4647/* Forward declaration. */ 4648static tree find_decl_and_mark_needed (tree decl, tree target); 4649 4650/* Emit any pending weak declarations. */ 4651 4652void 4653weak_finish (void) 4654{ 4655 tree t; 4656 4657 for (t = weakref_targets; t; t = TREE_CHAIN (t)) 4658 { 4659 tree alias_decl = TREE_PURPOSE (t); 4660 tree target = ultimate_transparent_alias_target (&TREE_VALUE (t)); 4661 4662 if (! TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (alias_decl))) 4663 /* Remove alias_decl from the weak list, but leave entries for 4664 the target alone. */ 4665 target = NULL_TREE; 4666#ifndef ASM_OUTPUT_WEAKREF 4667 else if (! TREE_SYMBOL_REFERENCED (target)) 4668 { 4669 /* Use ASM_WEAKEN_LABEL only if ASM_WEAKEN_DECL is not 4670 defined, otherwise we and weak_finish_1 would use a 4671 different macros. */ 4672# if defined ASM_WEAKEN_LABEL && ! defined ASM_WEAKEN_DECL 4673 ASM_WEAKEN_LABEL (asm_out_file, IDENTIFIER_POINTER (target)); 4674# else 4675 tree decl = find_decl_and_mark_needed (alias_decl, target); 4676 4677 if (! decl) 4678 { 4679 decl = build_decl (TREE_CODE (alias_decl), target, 4680 TREE_TYPE (alias_decl)); 4681 4682 DECL_EXTERNAL (decl) = 1; 4683 TREE_PUBLIC (decl) = 1; 4684 DECL_ARTIFICIAL (decl) = 1; 4685 TREE_NOTHROW (decl) = TREE_NOTHROW (alias_decl); 4686 TREE_USED (decl) = 1; 4687 } 4688 4689 weak_finish_1 (decl); 4690# endif 4691 } 4692#endif 4693 4694 { 4695 tree *p; 4696 tree t2; 4697 4698 /* Remove the alias and the target from the pending weak list 4699 so that we do not emit any .weak directives for the former, 4700 nor multiple .weak directives for the latter. */ 4701 for (p = &weak_decls; (t2 = *p) ; ) 4702 { 4703 if (TREE_VALUE (t2) == alias_decl 4704 || target == DECL_ASSEMBLER_NAME (TREE_VALUE (t2))) 4705 *p = TREE_CHAIN (t2); 4706 else 4707 p = &TREE_CHAIN (t2); 4708 } 4709 4710 /* Remove other weakrefs to the same target, to speed things up. */ 4711 for (p = &TREE_CHAIN (t); (t2 = *p) ; ) 4712 { 4713 if (target == ultimate_transparent_alias_target (&TREE_VALUE (t2))) 4714 *p = TREE_CHAIN (t2); 4715 else 4716 p = &TREE_CHAIN (t2); 4717 } 4718 } 4719 } 4720 4721 for (t = weak_decls; t; t = TREE_CHAIN (t)) 4722 { 4723 tree decl = TREE_VALUE (t); 4724 4725 weak_finish_1 (decl); 4726 } 4727} 4728 4729/* Emit the assembly bits to indicate that DECL is globally visible. */ 4730 4731static void 4732globalize_decl (tree decl) 4733{ 4734 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0); 4735 4736#if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL) 4737 if (DECL_WEAK (decl)) 4738 { 4739 tree *p, t; 4740 4741#ifdef ASM_WEAKEN_DECL 4742 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0); 4743#else 4744 ASM_WEAKEN_LABEL (asm_out_file, name); 4745#endif 4746 4747 /* Remove this function from the pending weak list so that 4748 we do not emit multiple .weak directives for it. */ 4749 for (p = &weak_decls; (t = *p) ; ) 4750 { 4751 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t))) 4752 *p = TREE_CHAIN (t); 4753 else 4754 p = &TREE_CHAIN (t); 4755 } 4756 4757 /* Remove weakrefs to the same target from the pending weakref 4758 list, for the same reason. */ 4759 for (p = &weakref_targets; (t = *p) ; ) 4760 { 4761 if (DECL_ASSEMBLER_NAME (decl) 4762 == ultimate_transparent_alias_target (&TREE_VALUE (t))) 4763 *p = TREE_CHAIN (t); 4764 else 4765 p = &TREE_CHAIN (t); 4766 } 4767 4768 return; 4769 } 4770#elif defined(ASM_MAKE_LABEL_LINKONCE) 4771 if (DECL_ONE_ONLY (decl)) 4772 ASM_MAKE_LABEL_LINKONCE (asm_out_file, name); 4773#endif 4774 4775 targetm.asm_out.globalize_label (asm_out_file, name); 4776} 4777 4778/* We have to be able to tell cgraph about the needed-ness of the target 4779 of an alias. This requires that the decl have been defined. Aliases 4780 that precede their definition have to be queued for later processing. */ 4781 4782typedef struct alias_pair GTY(()) 4783{ 4784 tree decl; 4785 tree target; 4786} alias_pair; 4787 4788/* Define gc'd vector type. */ 4789DEF_VEC_O(alias_pair); 4790DEF_VEC_ALLOC_O(alias_pair,gc); 4791 4792static GTY(()) VEC(alias_pair,gc) *alias_pairs; 4793 4794/* Given an assembly name, find the decl it is associated with. At the 4795 same time, mark it needed for cgraph. */ 4796 4797static tree 4798find_decl_and_mark_needed (tree decl, tree target) 4799{ 4800 struct cgraph_node *fnode = NULL; 4801 struct cgraph_varpool_node *vnode = NULL; 4802 4803 if (TREE_CODE (decl) == FUNCTION_DECL) 4804 { 4805 fnode = cgraph_node_for_asm (target); 4806 if (fnode == NULL) 4807 vnode = cgraph_varpool_node_for_asm (target); 4808 } 4809 else 4810 { 4811 vnode = cgraph_varpool_node_for_asm (target); 4812 if (vnode == NULL) 4813 fnode = cgraph_node_for_asm (target); 4814 } 4815 4816 if (fnode) 4817 { 4818 /* We can't mark function nodes as used after cgraph global info 4819 is finished. This wouldn't generally be necessary, but C++ 4820 virtual table thunks are introduced late in the game and 4821 might seem like they need marking, although in fact they 4822 don't. */ 4823 if (! cgraph_global_info_ready) 4824 cgraph_mark_needed_node (fnode); 4825 return fnode->decl; 4826 } 4827 else if (vnode) 4828 { 4829 cgraph_varpool_mark_needed_node (vnode); 4830 return vnode->decl; 4831 } 4832 else 4833 return NULL_TREE; 4834} 4835 4836/* Output the assembler code for a define (equate) using ASM_OUTPUT_DEF 4837 or ASM_OUTPUT_DEF_FROM_DECLS. The function defines the symbol whose 4838 tree node is DECL to have the value of the tree node TARGET. */ 4839 4840static void 4841do_assemble_alias (tree decl, tree target) 4842{ 4843 if (TREE_ASM_WRITTEN (decl)) 4844 return; 4845 4846 TREE_ASM_WRITTEN (decl) = 1; 4847 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1; 4848 4849 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl))) 4850 { 4851 ultimate_transparent_alias_target (&target); 4852 4853 if (!TREE_SYMBOL_REFERENCED (target)) 4854 weakref_targets = tree_cons (decl, target, weakref_targets); 4855 4856#ifdef ASM_OUTPUT_WEAKREF 4857 ASM_OUTPUT_WEAKREF (asm_out_file, decl, 4858 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)), 4859 IDENTIFIER_POINTER (target)); 4860#else 4861 if (!SUPPORTS_WEAK) 4862 { 4863 error ("%Jweakref is not supported in this configuration", decl); 4864 return; 4865 } 4866#endif 4867 return; 4868 } 4869 4870#ifdef ASM_OUTPUT_DEF 4871 /* Make name accessible from other files, if appropriate. */ 4872 4873 if (TREE_PUBLIC (decl)) 4874 { 4875 globalize_decl (decl); 4876 maybe_assemble_visibility (decl); 4877 } 4878 4879# ifdef ASM_OUTPUT_DEF_FROM_DECLS 4880 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target); 4881# else 4882 ASM_OUTPUT_DEF (asm_out_file, 4883 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)), 4884 IDENTIFIER_POINTER (target)); 4885# endif 4886#elif defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL) 4887 { 4888 const char *name; 4889 tree *p, t; 4890 4891 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)); 4892# ifdef ASM_WEAKEN_DECL 4893 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target)); 4894# else 4895 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target)); 4896# endif 4897 /* Remove this function from the pending weak list so that 4898 we do not emit multiple .weak directives for it. */ 4899 for (p = &weak_decls; (t = *p) ; ) 4900 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t))) 4901 *p = TREE_CHAIN (t); 4902 else 4903 p = &TREE_CHAIN (t); 4904 4905 /* Remove weakrefs to the same target from the pending weakref 4906 list, for the same reason. */ 4907 for (p = &weakref_targets; (t = *p) ; ) 4908 { 4909 if (DECL_ASSEMBLER_NAME (decl) 4910 == ultimate_transparent_alias_target (&TREE_VALUE (t))) 4911 *p = TREE_CHAIN (t); 4912 else 4913 p = &TREE_CHAIN (t); 4914 } 4915 } 4916#endif 4917} 4918 4919/* First pass of completing pending aliases. Make sure that cgraph knows 4920 which symbols will be required. */ 4921 4922void 4923finish_aliases_1 (void) 4924{ 4925 unsigned i; 4926 alias_pair *p; 4927 4928 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++) 4929 { 4930 tree target_decl; 4931 4932 target_decl = find_decl_and_mark_needed (p->decl, p->target); 4933 if (target_decl == NULL) 4934 { 4935 if (! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl))) 4936 error ("%q+D aliased to undefined symbol %qs", 4937 p->decl, IDENTIFIER_POINTER (p->target)); 4938 } 4939 else if (DECL_EXTERNAL (target_decl) 4940 && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl))) 4941 error ("%q+D aliased to external symbol %qs", 4942 p->decl, IDENTIFIER_POINTER (p->target)); 4943 } 4944} 4945 4946/* Second pass of completing pending aliases. Emit the actual assembly. 4947 This happens at the end of compilation and thus it is assured that the 4948 target symbol has been emitted. */ 4949 4950void 4951finish_aliases_2 (void) 4952{ 4953 unsigned i; 4954 alias_pair *p; 4955 4956 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++) 4957 do_assemble_alias (p->decl, p->target); 4958 4959 VEC_truncate (alias_pair, alias_pairs, 0); 4960} 4961 4962/* Emit an assembler directive to make the symbol for DECL an alias to 4963 the symbol for TARGET. */ 4964 4965void 4966assemble_alias (tree decl, tree target) 4967{ 4968 tree target_decl; 4969 bool is_weakref = false; 4970 4971 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl))) 4972 { 4973 tree alias = DECL_ASSEMBLER_NAME (decl); 4974 4975 is_weakref = true; 4976 4977 ultimate_transparent_alias_target (&target); 4978 4979 if (alias == target) 4980 error ("weakref %q+D ultimately targets itself", decl); 4981 else 4982 { 4983#ifndef ASM_OUTPUT_WEAKREF 4984 IDENTIFIER_TRANSPARENT_ALIAS (alias) = 1; 4985 TREE_CHAIN (alias) = target; 4986#endif 4987 } 4988 if (TREE_PUBLIC (decl)) 4989 error ("weakref %q+D must have static linkage", decl); 4990 } 4991 else 4992 { 4993#if !defined (ASM_OUTPUT_DEF) 4994# if !defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL) 4995 error ("%Jalias definitions not supported in this configuration", decl); 4996 return; 4997# else 4998 if (!DECL_WEAK (decl)) 4999 { 5000 error ("%Jonly weak aliases are supported in this configuration", decl); 5001 return; 5002 } 5003# endif 5004#endif 5005 } 5006 5007 /* We must force creation of DECL_RTL for debug info generation, even though 5008 we don't use it here. */ 5009 make_decl_rtl (decl); 5010 TREE_USED (decl) = 1; 5011 5012 /* A quirk of the initial implementation of aliases required that the user 5013 add "extern" to all of them. Which is silly, but now historical. Do 5014 note that the symbol is in fact locally defined. */ 5015 if (! is_weakref) 5016 DECL_EXTERNAL (decl) = 0; 5017 5018 /* Allow aliases to aliases. */ 5019 if (TREE_CODE (decl) == FUNCTION_DECL) 5020 cgraph_node (decl)->alias = true; 5021 else 5022 cgraph_varpool_node (decl)->alias = true; 5023 5024 /* If the target has already been emitted, we don't have to queue the 5025 alias. This saves a tad o memory. */ 5026 target_decl = find_decl_and_mark_needed (decl, target); 5027 if (target_decl && TREE_ASM_WRITTEN (target_decl)) 5028 do_assemble_alias (decl, target); 5029 else 5030 { 5031 alias_pair *p = VEC_safe_push (alias_pair, gc, alias_pairs, NULL); 5032 p->decl = decl; 5033 p->target = target; 5034 } 5035} 5036 5037/* Emit an assembler directive to set symbol for DECL visibility to 5038 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */ 5039 5040void 5041default_assemble_visibility (tree decl, int vis) 5042{ 5043 static const char * const visibility_types[] = { 5044 NULL, "protected", "hidden", "internal" 5045 }; 5046 5047 const char *name, *type; 5048 5049 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)); 5050 type = visibility_types[vis]; 5051 5052#ifdef HAVE_GAS_HIDDEN 5053 fprintf (asm_out_file, "\t.%s\t", type); 5054 assemble_name (asm_out_file, name); 5055 fprintf (asm_out_file, "\n"); 5056#else 5057 warning (OPT_Wattributes, "visibility attribute not supported " 5058 "in this configuration; ignored"); 5059#endif 5060} 5061 5062/* A helper function to call assemble_visibility when needed for a decl. */ 5063 5064int 5065maybe_assemble_visibility (tree decl) 5066{ 5067 enum symbol_visibility vis = DECL_VISIBILITY (decl); 5068 5069 if (vis != VISIBILITY_DEFAULT) 5070 { 5071 targetm.asm_out.visibility (decl, vis); 5072 return 1; 5073 } 5074 else 5075 return 0; 5076} 5077 5078/* Returns 1 if the target configuration supports defining public symbols 5079 so that one of them will be chosen at link time instead of generating a 5080 multiply-defined symbol error, whether through the use of weak symbols or 5081 a target-specific mechanism for having duplicates discarded. */ 5082 5083int 5084supports_one_only (void) 5085{ 5086 if (SUPPORTS_ONE_ONLY) 5087 return 1; 5088 return SUPPORTS_WEAK; 5089} 5090 5091/* Set up DECL as a public symbol that can be defined in multiple 5092 translation units without generating a linker error. */ 5093 5094void 5095make_decl_one_only (tree decl) 5096{ 5097 gcc_assert (TREE_CODE (decl) == VAR_DECL 5098 || TREE_CODE (decl) == FUNCTION_DECL); 5099 5100 TREE_PUBLIC (decl) = 1; 5101 5102 if (SUPPORTS_ONE_ONLY) 5103 { 5104#ifdef MAKE_DECL_ONE_ONLY 5105 MAKE_DECL_ONE_ONLY (decl); 5106#endif 5107 DECL_ONE_ONLY (decl) = 1; 5108 } 5109 else if (TREE_CODE (decl) == VAR_DECL 5110 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node)) 5111 DECL_COMMON (decl) = 1; 5112 else 5113 { 5114 gcc_assert (SUPPORTS_WEAK); 5115 DECL_WEAK (decl) = 1; 5116 } 5117} 5118 5119void 5120init_varasm_once (void) 5121{ 5122 section_htab = htab_create_ggc (31, section_entry_hash, 5123 section_entry_eq, NULL); 5124 object_block_htab = htab_create_ggc (31, object_block_entry_hash, 5125 object_block_entry_eq, NULL); 5126 const_desc_htab = htab_create_ggc (1009, const_desc_hash, 5127 const_desc_eq, NULL); 5128 5129 const_alias_set = new_alias_set (); 5130 shared_constant_pool = create_constant_pool (); 5131 5132#ifdef TEXT_SECTION_ASM_OP 5133 text_section = get_unnamed_section (SECTION_CODE, output_section_asm_op, 5134 TEXT_SECTION_ASM_OP); 5135#endif 5136 5137#ifdef DATA_SECTION_ASM_OP 5138 data_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op, 5139 DATA_SECTION_ASM_OP); 5140#endif 5141 5142#ifdef SDATA_SECTION_ASM_OP 5143 sdata_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op, 5144 SDATA_SECTION_ASM_OP); 5145#endif 5146 5147#ifdef READONLY_DATA_SECTION_ASM_OP 5148 readonly_data_section = get_unnamed_section (0, output_section_asm_op, 5149 READONLY_DATA_SECTION_ASM_OP); 5150#endif 5151 5152#ifdef CTORS_SECTION_ASM_OP 5153 ctors_section = get_unnamed_section (0, output_section_asm_op, 5154 CTORS_SECTION_ASM_OP); 5155#endif 5156 5157#ifdef DTORS_SECTION_ASM_OP 5158 dtors_section = get_unnamed_section (0, output_section_asm_op, 5159 DTORS_SECTION_ASM_OP); 5160#endif 5161 5162#ifdef BSS_SECTION_ASM_OP 5163 bss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS, 5164 output_section_asm_op, 5165 BSS_SECTION_ASM_OP); 5166#endif 5167 5168#ifdef SBSS_SECTION_ASM_OP 5169 sbss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS, 5170 output_section_asm_op, 5171 SBSS_SECTION_ASM_OP); 5172#endif 5173 5174 tls_comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS 5175 | SECTION_COMMON, emit_tls_common); 5176 lcomm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS 5177 | SECTION_COMMON, emit_local); 5178 comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS 5179 | SECTION_COMMON, emit_common); 5180 5181#if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS 5182 bss_noswitch_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS, 5183 emit_bss); 5184#endif 5185 5186 targetm.asm_out.init_sections (); 5187 5188 if (readonly_data_section == NULL) 5189 readonly_data_section = text_section; 5190} 5191 5192enum tls_model 5193decl_default_tls_model (tree decl) 5194{ 5195 enum tls_model kind; 5196 bool is_local; 5197 5198 is_local = targetm.binds_local_p (decl); 5199 if (!flag_shlib) 5200 { 5201 if (is_local) 5202 kind = TLS_MODEL_LOCAL_EXEC; 5203 else 5204 kind = TLS_MODEL_INITIAL_EXEC; 5205 } 5206 5207 /* Local dynamic is inefficient when we're not combining the 5208 parts of the address. */ 5209 else if (optimize && is_local) 5210 kind = TLS_MODEL_LOCAL_DYNAMIC; 5211 else 5212 kind = TLS_MODEL_GLOBAL_DYNAMIC; 5213 if (kind < flag_tls_default) 5214 kind = flag_tls_default; 5215 5216 return kind; 5217} 5218 5219/* Select a set of attributes for section NAME based on the properties 5220 of DECL and whether or not RELOC indicates that DECL's initializer 5221 might contain runtime relocations. 5222 5223 We make the section read-only and executable for a function decl, 5224 read-only for a const data decl, and writable for a non-const data decl. */ 5225 5226unsigned int 5227default_section_type_flags (tree decl, const char *name, int reloc) 5228{ 5229 unsigned int flags; 5230 5231 if (decl && TREE_CODE (decl) == FUNCTION_DECL) 5232 flags = SECTION_CODE; 5233 else if (decl && decl_readonly_section (decl, reloc)) 5234 flags = 0; 5235 else if (current_function_decl 5236 && cfun 5237 && cfun->unlikely_text_section_name 5238 && strcmp (name, cfun->unlikely_text_section_name) == 0) 5239 flags = SECTION_CODE; 5240 else if (!decl 5241 && (!current_function_decl || !cfun) 5242 && strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0) 5243 flags = SECTION_CODE; 5244 else 5245 flags = SECTION_WRITE; 5246 5247 if (decl && DECL_ONE_ONLY (decl)) 5248 flags |= SECTION_LINKONCE; 5249 5250 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl)) 5251 flags |= SECTION_TLS | SECTION_WRITE; 5252 5253 if (strcmp (name, ".bss") == 0 5254 || strncmp (name, ".bss.", 5) == 0 5255 || strncmp (name, ".gnu.linkonce.b.", 16) == 0 5256 || strcmp (name, ".sbss") == 0 5257 || strncmp (name, ".sbss.", 6) == 0 5258 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0) 5259 flags |= SECTION_BSS; 5260 5261 if (strcmp (name, ".tdata") == 0 5262 || strncmp (name, ".tdata.", 7) == 0 5263 || strncmp (name, ".gnu.linkonce.td.", 17) == 0) 5264 flags |= SECTION_TLS; 5265 5266 if (strcmp (name, ".tbss") == 0 5267 || strncmp (name, ".tbss.", 6) == 0 5268 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0) 5269 flags |= SECTION_TLS | SECTION_BSS; 5270 5271 /* These three sections have special ELF types. They are neither 5272 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't 5273 want to print a section type (@progbits or @nobits). If someone 5274 is silly enough to emit code or TLS variables to one of these 5275 sections, then don't handle them specially. */ 5276 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS)) 5277 && (strcmp (name, ".init_array") == 0 5278 || strcmp (name, ".fini_array") == 0 5279 || strcmp (name, ".preinit_array") == 0)) 5280 flags |= SECTION_NOTYPE; 5281 5282 return flags; 5283} 5284 5285/* Return true if the target supports some form of global BSS, 5286 either through bss_noswitch_section, or by selecting a BSS 5287 section in TARGET_ASM_SELECT_SECTION. */ 5288 5289bool 5290have_global_bss_p (void) 5291{ 5292 return bss_noswitch_section || targetm.have_switchable_bss_sections; 5293} 5294 5295/* Output assembly to switch to section NAME with attribute FLAGS. 5296 Four variants for common object file formats. */ 5297 5298void 5299default_no_named_section (const char *name ATTRIBUTE_UNUSED, 5300 unsigned int flags ATTRIBUTE_UNUSED, 5301 tree decl ATTRIBUTE_UNUSED) 5302{ 5303 /* Some object formats don't support named sections at all. The 5304 front-end should already have flagged this as an error. */ 5305 gcc_unreachable (); 5306} 5307 5308void 5309default_elf_asm_named_section (const char *name, unsigned int flags, 5310 tree decl ATTRIBUTE_UNUSED) 5311{ 5312 char flagchars[10], *f = flagchars; 5313 5314 /* If we have already declared this section, we can use an 5315 abbreviated form to switch back to it -- unless this section is 5316 part of a COMDAT groups, in which case GAS requires the full 5317 declaration every time. */ 5318 if (!(HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE)) 5319 && (flags & SECTION_DECLARED)) 5320 { 5321 fprintf (asm_out_file, "\t.section\t%s\n", name); 5322 return; 5323 } 5324 5325 if (!(flags & SECTION_DEBUG)) 5326 *f++ = 'a'; 5327 if (flags & SECTION_WRITE) 5328 *f++ = 'w'; 5329 if (flags & SECTION_CODE) 5330 *f++ = 'x'; 5331 if (flags & SECTION_SMALL) 5332 *f++ = 's'; 5333 if (flags & SECTION_MERGE) 5334 *f++ = 'M'; 5335 if (flags & SECTION_STRINGS) 5336 *f++ = 'S'; 5337 if (flags & SECTION_TLS) 5338 *f++ = 'T'; 5339 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE)) 5340 *f++ = 'G'; 5341 *f = '\0'; 5342 5343 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars); 5344 5345 if (!(flags & SECTION_NOTYPE)) 5346 { 5347 const char *type; 5348 const char *format; 5349 5350 if (flags & SECTION_BSS) 5351 type = "nobits"; 5352 else 5353 type = "progbits"; 5354 5355 format = ",@%s"; 5356#ifdef ASM_COMMENT_START 5357 /* On platforms that use "@" as the assembly comment character, 5358 use "%" instead. */ 5359 if (strcmp (ASM_COMMENT_START, "@") == 0) 5360 format = ",%%%s"; 5361#endif 5362 fprintf (asm_out_file, format, type); 5363 5364 if (flags & SECTION_ENTSIZE) 5365 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE); 5366 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE)) 5367 fprintf (asm_out_file, ",%s,comdat", 5368 lang_hooks.decls.comdat_group (decl)); 5369 } 5370 5371 putc ('\n', asm_out_file); 5372} 5373 5374void 5375default_coff_asm_named_section (const char *name, unsigned int flags, 5376 tree decl ATTRIBUTE_UNUSED) 5377{ 5378 char flagchars[8], *f = flagchars; 5379 5380 if (flags & SECTION_WRITE) 5381 *f++ = 'w'; 5382 if (flags & SECTION_CODE) 5383 *f++ = 'x'; 5384 *f = '\0'; 5385 5386 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars); 5387} 5388 5389void 5390default_pe_asm_named_section (const char *name, unsigned int flags, 5391 tree decl) 5392{ 5393 default_coff_asm_named_section (name, flags, decl); 5394 5395 if (flags & SECTION_LINKONCE) 5396 { 5397 /* Functions may have been compiled at various levels of 5398 optimization so we can't use `same_size' here. 5399 Instead, have the linker pick one. */ 5400 fprintf (asm_out_file, "\t.linkonce %s\n", 5401 (flags & SECTION_CODE ? "discard" : "same_size")); 5402 } 5403} 5404 5405/* The lame default section selector. */ 5406 5407section * 5408default_select_section (tree decl, int reloc, 5409 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED) 5410{ 5411 if (DECL_P (decl)) 5412 { 5413 if (decl_readonly_section (decl, reloc)) 5414 return readonly_data_section; 5415 } 5416 else if (TREE_CODE (decl) == CONSTRUCTOR) 5417 { 5418 if (! ((flag_pic && reloc) 5419 || !TREE_READONLY (decl) 5420 || TREE_SIDE_EFFECTS (decl) 5421 || !TREE_CONSTANT (decl))) 5422 return readonly_data_section; 5423 } 5424 else if (TREE_CODE (decl) == STRING_CST) 5425 return readonly_data_section; 5426 else if (! (flag_pic && reloc)) 5427 return readonly_data_section; 5428 5429 return data_section; 5430} 5431 5432enum section_category 5433categorize_decl_for_section (tree decl, int reloc) 5434{ 5435 enum section_category ret; 5436 5437 if (TREE_CODE (decl) == FUNCTION_DECL) 5438 return SECCAT_TEXT; 5439 else if (TREE_CODE (decl) == STRING_CST) 5440 { 5441 if (flag_mudflap) /* or !flag_merge_constants */ 5442 return SECCAT_RODATA; 5443 else 5444 return SECCAT_RODATA_MERGE_STR; 5445 } 5446 else if (TREE_CODE (decl) == VAR_DECL) 5447 { 5448 if (bss_initializer_p (decl)) 5449 ret = SECCAT_BSS; 5450 else if (! TREE_READONLY (decl) 5451 || TREE_SIDE_EFFECTS (decl) 5452 || ! TREE_CONSTANT (DECL_INITIAL (decl))) 5453 { 5454 /* Here the reloc_rw_mask is not testing whether the section should 5455 be read-only or not, but whether the dynamic link will have to 5456 do something. If so, we wish to segregate the data in order to 5457 minimize cache misses inside the dynamic linker. */ 5458 if (reloc & targetm.asm_out.reloc_rw_mask ()) 5459 ret = reloc == 1 ? SECCAT_DATA_REL_LOCAL : SECCAT_DATA_REL; 5460 else 5461 ret = SECCAT_DATA; 5462 } 5463 else if (reloc & targetm.asm_out.reloc_rw_mask ()) 5464 ret = reloc == 1 ? SECCAT_DATA_REL_RO_LOCAL : SECCAT_DATA_REL_RO; 5465 else if (reloc || flag_merge_constants < 2) 5466 /* C and C++ don't allow different variables to share the same 5467 location. -fmerge-all-constants allows even that (at the 5468 expense of not conforming). */ 5469 ret = SECCAT_RODATA; 5470 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST) 5471 ret = SECCAT_RODATA_MERGE_STR_INIT; 5472 else 5473 ret = SECCAT_RODATA_MERGE_CONST; 5474 } 5475 else if (TREE_CODE (decl) == CONSTRUCTOR) 5476 { 5477 if ((reloc & targetm.asm_out.reloc_rw_mask ()) 5478 || TREE_SIDE_EFFECTS (decl) 5479 || ! TREE_CONSTANT (decl)) 5480 ret = SECCAT_DATA; 5481 else 5482 ret = SECCAT_RODATA; 5483 } 5484 else 5485 ret = SECCAT_RODATA; 5486 5487 /* There are no read-only thread-local sections. */ 5488 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl)) 5489 { 5490 /* Note that this would be *just* SECCAT_BSS, except that there's 5491 no concept of a read-only thread-local-data section. */ 5492 if (ret == SECCAT_BSS 5493 || (flag_zero_initialized_in_bss 5494 && initializer_zerop (DECL_INITIAL (decl)))) 5495 ret = SECCAT_TBSS; 5496 else 5497 ret = SECCAT_TDATA; 5498 } 5499 5500 /* If the target uses small data sections, select it. */ 5501 else if (targetm.in_small_data_p (decl)) 5502 { 5503 if (ret == SECCAT_BSS) 5504 ret = SECCAT_SBSS; 5505 else if (targetm.have_srodata_section && ret == SECCAT_RODATA) 5506 ret = SECCAT_SRODATA; 5507 else 5508 ret = SECCAT_SDATA; 5509 } 5510 5511 return ret; 5512} 5513 5514bool 5515decl_readonly_section (tree decl, int reloc) 5516{ 5517 switch (categorize_decl_for_section (decl, reloc)) 5518 { 5519 case SECCAT_RODATA: 5520 case SECCAT_RODATA_MERGE_STR: 5521 case SECCAT_RODATA_MERGE_STR_INIT: 5522 case SECCAT_RODATA_MERGE_CONST: 5523 case SECCAT_SRODATA: 5524 return true; 5525 break; 5526 default: 5527 return false; 5528 break; 5529 } 5530} 5531 5532/* Select a section based on the above categorization. */ 5533 5534section * 5535default_elf_select_section (tree decl, int reloc, 5536 unsigned HOST_WIDE_INT align) 5537{ 5538 const char *sname; 5539 switch (categorize_decl_for_section (decl, reloc)) 5540 { 5541 case SECCAT_TEXT: 5542 /* We're not supposed to be called on FUNCTION_DECLs. */ 5543 gcc_unreachable (); 5544 case SECCAT_RODATA: 5545 return readonly_data_section; 5546 case SECCAT_RODATA_MERGE_STR: 5547 return mergeable_string_section (decl, align, 0); 5548 case SECCAT_RODATA_MERGE_STR_INIT: 5549 return mergeable_string_section (DECL_INITIAL (decl), align, 0); 5550 case SECCAT_RODATA_MERGE_CONST: 5551 return mergeable_constant_section (DECL_MODE (decl), align, 0); 5552 case SECCAT_SRODATA: 5553 sname = ".sdata2"; 5554 break; 5555 case SECCAT_DATA: 5556 return data_section; 5557 case SECCAT_DATA_REL: 5558 sname = ".data.rel"; 5559 break; 5560 case SECCAT_DATA_REL_LOCAL: 5561 sname = ".data.rel.local"; 5562 break; 5563 case SECCAT_DATA_REL_RO: 5564 sname = ".data.rel.ro"; 5565 break; 5566 case SECCAT_DATA_REL_RO_LOCAL: 5567 sname = ".data.rel.ro.local"; 5568 break; 5569 case SECCAT_SDATA: 5570 sname = ".sdata"; 5571 break; 5572 case SECCAT_TDATA: 5573 sname = ".tdata"; 5574 break; 5575 case SECCAT_BSS: 5576 if (bss_section) 5577 return bss_section; 5578 sname = ".bss"; 5579 break; 5580 case SECCAT_SBSS: 5581 sname = ".sbss"; 5582 break; 5583 case SECCAT_TBSS: 5584 sname = ".tbss"; 5585 break; 5586 default: 5587 gcc_unreachable (); 5588 } 5589 5590 if (!DECL_P (decl)) 5591 decl = NULL_TREE; 5592 return get_named_section (decl, sname, reloc); 5593} 5594 5595/* Construct a unique section name based on the decl name and the 5596 categorization performed above. */ 5597 5598void 5599default_unique_section (tree decl, int reloc) 5600{ 5601 /* We only need to use .gnu.linkonce if we don't have COMDAT groups. */ 5602 bool one_only = DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP; 5603 const char *prefix, *name; 5604 size_t nlen, plen; 5605 char *string; 5606 5607 switch (categorize_decl_for_section (decl, reloc)) 5608 { 5609 case SECCAT_TEXT: 5610 prefix = one_only ? ".gnu.linkonce.t." : ".text."; 5611 break; 5612 case SECCAT_RODATA: 5613 case SECCAT_RODATA_MERGE_STR: 5614 case SECCAT_RODATA_MERGE_STR_INIT: 5615 case SECCAT_RODATA_MERGE_CONST: 5616 prefix = one_only ? ".gnu.linkonce.r." : ".rodata."; 5617 break; 5618 case SECCAT_SRODATA: 5619 prefix = one_only ? ".gnu.linkonce.s2." : ".sdata2."; 5620 break; 5621 case SECCAT_DATA: 5622 prefix = one_only ? ".gnu.linkonce.d." : ".data."; 5623 break; 5624 case SECCAT_DATA_REL: 5625 prefix = one_only ? ".gnu.linkonce.d.rel." : ".data.rel."; 5626 break; 5627 case SECCAT_DATA_REL_LOCAL: 5628 prefix = one_only ? ".gnu.linkonce.d.rel.local." : ".data.rel.local."; 5629 break; 5630 case SECCAT_DATA_REL_RO: 5631 prefix = one_only ? ".gnu.linkonce.d.rel.ro." : ".data.rel.ro."; 5632 break; 5633 case SECCAT_DATA_REL_RO_LOCAL: 5634 prefix = one_only ? ".gnu.linkonce.d.rel.ro.local." 5635 : ".data.rel.ro.local."; 5636 break; 5637 case SECCAT_SDATA: 5638 prefix = one_only ? ".gnu.linkonce.s." : ".sdata."; 5639 break; 5640 case SECCAT_BSS: 5641 prefix = one_only ? ".gnu.linkonce.b." : ".bss."; 5642 break; 5643 case SECCAT_SBSS: 5644 prefix = one_only ? ".gnu.linkonce.sb." : ".sbss."; 5645 break; 5646 case SECCAT_TDATA: 5647 prefix = one_only ? ".gnu.linkonce.td." : ".tdata."; 5648 break; 5649 case SECCAT_TBSS: 5650 prefix = one_only ? ".gnu.linkonce.tb." : ".tbss."; 5651 break; 5652 default: 5653 gcc_unreachable (); 5654 } 5655 plen = strlen (prefix); 5656 5657 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)); 5658 name = targetm.strip_name_encoding (name); 5659 nlen = strlen (name); 5660 5661 string = alloca (nlen + plen + 1); 5662 memcpy (string, prefix, plen); 5663 memcpy (string + plen, name, nlen + 1); 5664 5665 DECL_SECTION_NAME (decl) = build_string (nlen + plen, string); 5666} 5667 5668/* Like compute_reloc_for_constant, except for an RTX. The return value 5669 is a mask for which bit 1 indicates a global relocation, and bit 0 5670 indicates a local relocation. */ 5671 5672static int 5673compute_reloc_for_rtx_1 (rtx *xp, void *data) 5674{ 5675 int *preloc = data; 5676 rtx x = *xp; 5677 5678 switch (GET_CODE (x)) 5679 { 5680 case SYMBOL_REF: 5681 *preloc |= SYMBOL_REF_LOCAL_P (x) ? 1 : 2; 5682 break; 5683 case LABEL_REF: 5684 *preloc |= 1; 5685 break; 5686 default: 5687 break; 5688 } 5689 5690 return 0; 5691} 5692 5693static int 5694compute_reloc_for_rtx (rtx x) 5695{ 5696 int reloc; 5697 5698 switch (GET_CODE (x)) 5699 { 5700 case CONST: 5701 case SYMBOL_REF: 5702 case LABEL_REF: 5703 reloc = 0; 5704 for_each_rtx (&x, compute_reloc_for_rtx_1, &reloc); 5705 return reloc; 5706 5707 default: 5708 return 0; 5709 } 5710} 5711 5712section * 5713default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED, 5714 rtx x, 5715 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED) 5716{ 5717 if (compute_reloc_for_rtx (x) & targetm.asm_out.reloc_rw_mask ()) 5718 return data_section; 5719 else 5720 return readonly_data_section; 5721} 5722 5723section * 5724default_elf_select_rtx_section (enum machine_mode mode, rtx x, 5725 unsigned HOST_WIDE_INT align) 5726{ 5727 int reloc = compute_reloc_for_rtx (x); 5728 5729 /* ??? Handle small data here somehow. */ 5730 5731 if (reloc & targetm.asm_out.reloc_rw_mask ()) 5732 { 5733 if (reloc == 1) 5734 return get_named_section (NULL, ".data.rel.ro.local", 1); 5735 else 5736 return get_named_section (NULL, ".data.rel.ro", 3); 5737 } 5738 5739 return mergeable_constant_section (mode, align, 0); 5740} 5741 5742/* Set the generally applicable flags on the SYMBOL_REF for EXP. */ 5743 5744void 5745default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED) 5746{ 5747 rtx symbol; 5748 int flags; 5749 5750 /* Careful not to prod global register variables. */ 5751 if (!MEM_P (rtl)) 5752 return; 5753 symbol = XEXP (rtl, 0); 5754 if (GET_CODE (symbol) != SYMBOL_REF) 5755 return; 5756 5757 flags = SYMBOL_REF_FLAGS (symbol) & SYMBOL_FLAG_HAS_BLOCK_INFO; 5758 if (TREE_CODE (decl) == FUNCTION_DECL) 5759 flags |= SYMBOL_FLAG_FUNCTION; 5760 if (targetm.binds_local_p (decl)) 5761 flags |= SYMBOL_FLAG_LOCAL; 5762 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl)) 5763 flags |= DECL_TLS_MODEL (decl) << SYMBOL_FLAG_TLS_SHIFT; 5764 else if (targetm.in_small_data_p (decl)) 5765 flags |= SYMBOL_FLAG_SMALL; 5766 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without 5767 being PUBLIC, the thing *must* be defined in this translation unit. 5768 Prevent this buglet from being propagated into rtl code as well. */ 5769 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl)) 5770 flags |= SYMBOL_FLAG_EXTERNAL; 5771 5772 SYMBOL_REF_FLAGS (symbol) = flags; 5773} 5774 5775/* By default, we do nothing for encode_section_info, so we need not 5776 do anything but discard the '*' marker. */ 5777 5778const char * 5779default_strip_name_encoding (const char *str) 5780{ 5781 return str + (*str == '*'); 5782} 5783 5784#ifdef ASM_OUTPUT_DEF 5785/* The default implementation of TARGET_ASM_OUTPUT_ANCHOR. Define the 5786 anchor relative to ".", the current section position. */ 5787 5788void 5789default_asm_output_anchor (rtx symbol) 5790{ 5791 char buffer[100]; 5792 5793 sprintf (buffer, ". + " HOST_WIDE_INT_PRINT_DEC, 5794 SYMBOL_REF_BLOCK_OFFSET (symbol)); 5795 ASM_OUTPUT_DEF (asm_out_file, XSTR (symbol, 0), buffer); 5796} 5797#endif 5798 5799/* The default implementation of TARGET_USE_ANCHORS_FOR_SYMBOL_P. */ 5800 5801bool 5802default_use_anchors_for_symbol_p (rtx symbol) 5803{ 5804 section *sect; 5805 tree decl; 5806 5807 /* Don't use anchors for mergeable sections. The linker might move 5808 the objects around. */ 5809 sect = SYMBOL_REF_BLOCK (symbol)->sect; 5810 if (sect->common.flags & SECTION_MERGE) 5811 return false; 5812 5813 /* Don't use anchors for small data sections. The small data register 5814 acts as an anchor for such sections. */ 5815 if (sect->common.flags & SECTION_SMALL) 5816 return false; 5817 5818 decl = SYMBOL_REF_DECL (symbol); 5819 if (decl && DECL_P (decl)) 5820 { 5821 /* Don't use section anchors for decls that might be defined by 5822 other modules. */ 5823 if (!targetm.binds_local_p (decl)) 5824 return false; 5825 5826 /* Don't use section anchors for decls that will be placed in a 5827 small data section. */ 5828 /* ??? Ideally, this check would be redundant with the SECTION_SMALL 5829 one above. The problem is that we only use SECTION_SMALL for 5830 sections that should be marked as small in the section directive. */ 5831 if (targetm.in_small_data_p (decl)) 5832 return false; 5833 } 5834 return true; 5835} 5836 5837/* Assume ELF-ish defaults, since that's pretty much the most liberal 5838 wrt cross-module name binding. */ 5839 5840bool 5841default_binds_local_p (tree exp) 5842{ 5843 return default_binds_local_p_1 (exp, flag_shlib); 5844} 5845 5846bool 5847default_binds_local_p_1 (tree exp, int shlib) 5848{ 5849 bool local_p; 5850 5851 /* A non-decl is an entry in the constant pool. */ 5852 if (!DECL_P (exp)) 5853 local_p = true; 5854 /* Weakrefs may not bind locally, even though the weakref itself is 5855 always static and therefore local. */ 5856 else if (lookup_attribute ("weakref", DECL_ATTRIBUTES (exp))) 5857 local_p = false; 5858 /* Static variables are always local. */ 5859 else if (! TREE_PUBLIC (exp)) 5860 local_p = true; 5861 /* A variable is local if the user has said explicitly that it will 5862 be. */ 5863 else if (DECL_VISIBILITY_SPECIFIED (exp) 5864 && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT) 5865 local_p = true; 5866 /* Variables defined outside this object might not be local. */ 5867 else if (DECL_EXTERNAL (exp)) 5868 local_p = false; 5869 /* If defined in this object and visibility is not default, must be 5870 local. */ 5871 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT) 5872 local_p = true; 5873 /* Default visibility weak data can be overridden by a strong symbol 5874 in another module and so are not local. */ 5875 else if (DECL_WEAK (exp)) 5876 local_p = false; 5877 /* If PIC, then assume that any global name can be overridden by 5878 symbols resolved from other modules, unless we are compiling with 5879 -fwhole-program, which assumes that names are local. */ 5880 else if (shlib) 5881 local_p = flag_whole_program; 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. */ 5898bool 5899default_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 5908void 5909default_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. */ 5920void 5921default_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. */ 5931void 5932default_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 5939void 5940default_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. */ 5950void 5951default_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 5965int trampolines_created; 5966 5967void 5968file_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 5980void 5981output_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 5989void 5990switch_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 6029void 6030place_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 6079rtx 6080get_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 6161static void 6162output_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 6215static int 6216output_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 6224void 6225output_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. */ 6232void 6233default_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