varasm.c revision 215840
1284345Ssjg/* Output variables, constants and external declarations, for GNU compiler. 2284345Ssjg Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 3284345Ssjg 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 4284345Ssjg Free Software Foundation, Inc. 5284345Ssjg 6284345SsjgThis file is part of GCC. 7284345Ssjg 8284345SsjgGCC is free software; you can redistribute it and/or modify it under 9284345Ssjgthe terms of the GNU General Public License as published by the Free 10284345SsjgSoftware Foundation; either version 2, or (at your option) any later 11284345Ssjgversion. 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 (FUNCTION_BOUNDARY); 1387 ASM_OUTPUT_LABEL (asm_out_file, cfun->cold_section_label); 1388 1389 /* When the function starts with a cold section, we need to explicitly 1390 align the hot section and write out the hot section label. 1391 But if the current function is a thunk, we do not have a CFG. */ 1392 if (!current_function_is_thunk 1393 && BB_PARTITION (ENTRY_BLOCK_PTR->next_bb) == BB_COLD_PARTITION) 1394 { 1395 switch_to_section (text_section); 1396 assemble_align (FUNCTION_BOUNDARY); 1397 ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_label); 1398 hot_label_written = true; 1399 first_function_block_is_cold = true; 1400 } 1401 } 1402 else if (DECL_SECTION_NAME (decl)) 1403 { 1404 /* Calls to function_section rely on first_function_block_is_cold 1405 being accurate. The first block may be cold even if we aren't 1406 doing partitioning, if the entire function was decided by 1407 choose_function_section (predict.c) to be cold. */ 1408 1409 initialize_cold_section_name (); 1410 1411 if (cfun->unlikely_text_section_name 1412 && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)), 1413 cfun->unlikely_text_section_name) == 0) 1414 first_function_block_is_cold = true; 1415 } 1416 1417 in_cold_section_p = first_function_block_is_cold; 1418 1419 /* Switch to the correct text section for the start of the function. */ 1420 1421 switch_to_section (function_section (decl)); 1422 if (flag_reorder_blocks_and_partition 1423 && !hot_label_written) 1424 ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_label); 1425 1426 /* Tell assembler to move to target machine's alignment for functions. */ 1427 align = floor_log2 (FUNCTION_BOUNDARY / BITS_PER_UNIT); 1428 if (align < force_align_functions_log) 1429 align = force_align_functions_log; 1430 if (align > 0) 1431 { 1432 ASM_OUTPUT_ALIGN (asm_out_file, align); 1433 } 1434 1435 /* Handle a user-specified function alignment. 1436 Note that we still need to align to FUNCTION_BOUNDARY, as above, 1437 because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */ 1438 if (align_functions_log > align 1439 && cfun->function_frequency != FUNCTION_FREQUENCY_UNLIKELY_EXECUTED) 1440 { 1441#ifdef ASM_OUTPUT_MAX_SKIP_ALIGN 1442 ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file, 1443 align_functions_log, align_functions - 1); 1444#else 1445 ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log); 1446#endif 1447 } 1448 1449#ifdef ASM_OUTPUT_FUNCTION_PREFIX 1450 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname); 1451#endif 1452 1453 (*debug_hooks->begin_function) (decl); 1454 1455 /* Make function name accessible from other files, if appropriate. */ 1456 1457 if (TREE_PUBLIC (decl)) 1458 { 1459 notice_global_symbol (decl); 1460 1461 globalize_decl (decl); 1462 1463 maybe_assemble_visibility (decl); 1464 } 1465 1466 if (DECL_PRESERVE_P (decl)) 1467 targetm.asm_out.mark_decl_preserved (fnname); 1468 1469 /* Do any machine/system dependent processing of the function name. */ 1470#ifdef ASM_DECLARE_FUNCTION_NAME 1471 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl); 1472#else 1473 /* Standard thing is just output label for the function. */ 1474 ASM_OUTPUT_LABEL (asm_out_file, fnname); 1475#endif /* ASM_DECLARE_FUNCTION_NAME */ 1476} 1477 1478/* Output assembler code associated with defining the size of the 1479 function. DECL describes the function. NAME is the function's name. */ 1480 1481void 1482assemble_end_function (tree decl, const char *fnname ATTRIBUTE_UNUSED) 1483{ 1484#ifdef ASM_DECLARE_FUNCTION_SIZE 1485 /* We could have switched section in the middle of the function. */ 1486 if (flag_reorder_blocks_and_partition) 1487 switch_to_section (function_section (decl)); 1488 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl); 1489#endif 1490 if (! CONSTANT_POOL_BEFORE_FUNCTION) 1491 { 1492 output_constant_pool (fnname, decl); 1493 switch_to_section (function_section (decl)); /* need to switch back */ 1494 } 1495 /* Output labels for end of hot/cold text sections (to be used by 1496 debug info.) */ 1497 if (flag_reorder_blocks_and_partition) 1498 { 1499 section *save_text_section; 1500 1501 save_text_section = in_section; 1502 switch_to_section (unlikely_text_section ()); 1503 ASM_OUTPUT_LABEL (asm_out_file, cfun->cold_section_end_label); 1504 if (first_function_block_is_cold) 1505 switch_to_section (text_section); 1506 else 1507 switch_to_section (function_section (decl)); 1508 ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_end_label); 1509 switch_to_section (save_text_section); 1510 } 1511} 1512 1513/* Assemble code to leave SIZE bytes of zeros. */ 1514 1515void 1516assemble_zeros (unsigned HOST_WIDE_INT size) 1517{ 1518 /* Do no output if -fsyntax-only. */ 1519 if (flag_syntax_only) 1520 return; 1521 1522#ifdef ASM_NO_SKIP_IN_TEXT 1523 /* The `space' pseudo in the text section outputs nop insns rather than 0s, 1524 so we must output 0s explicitly in the text section. */ 1525 if (ASM_NO_SKIP_IN_TEXT && (in_section->common.flags & SECTION_CODE) != 0) 1526 { 1527 unsigned HOST_WIDE_INT i; 1528 for (i = 0; i < size; i++) 1529 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1); 1530 } 1531 else 1532#endif 1533 if (size > 0) 1534 ASM_OUTPUT_SKIP (asm_out_file, size); 1535} 1536 1537/* Assemble an alignment pseudo op for an ALIGN-bit boundary. */ 1538 1539void 1540assemble_align (int align) 1541{ 1542 if (align > BITS_PER_UNIT) 1543 { 1544 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT)); 1545 } 1546} 1547 1548/* Assemble a string constant with the specified C string as contents. */ 1549 1550void 1551assemble_string (const char *p, int size) 1552{ 1553 int pos = 0; 1554 int maximum = 2000; 1555 1556 /* If the string is very long, split it up. */ 1557 1558 while (pos < size) 1559 { 1560 int thissize = size - pos; 1561 if (thissize > maximum) 1562 thissize = maximum; 1563 1564 ASM_OUTPUT_ASCII (asm_out_file, p, thissize); 1565 1566 pos += thissize; 1567 p += thissize; 1568 } 1569} 1570 1571 1572/* A noswitch_section_callback for lcomm_section. */ 1573 1574static bool 1575emit_local (tree decl ATTRIBUTE_UNUSED, 1576 const char *name ATTRIBUTE_UNUSED, 1577 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED, 1578 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED) 1579{ 1580#if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL 1581 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name, 1582 size, DECL_ALIGN (decl)); 1583 return true; 1584#elif defined ASM_OUTPUT_ALIGNED_LOCAL 1585 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl)); 1586 return true; 1587#else 1588 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded); 1589 return false; 1590#endif 1591} 1592 1593/* A noswitch_section_callback for bss_noswitch_section. */ 1594 1595#if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS 1596static bool 1597emit_bss (tree decl ATTRIBUTE_UNUSED, 1598 const char *name ATTRIBUTE_UNUSED, 1599 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED, 1600 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED) 1601{ 1602#if defined ASM_OUTPUT_ALIGNED_BSS 1603 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl)); 1604 return true; 1605#else 1606 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded); 1607 return false; 1608#endif 1609} 1610#endif 1611 1612/* A noswitch_section_callback for comm_section. */ 1613 1614static bool 1615emit_common (tree decl ATTRIBUTE_UNUSED, 1616 const char *name ATTRIBUTE_UNUSED, 1617 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED, 1618 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED) 1619{ 1620#if defined ASM_OUTPUT_ALIGNED_DECL_COMMON 1621 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name, 1622 size, DECL_ALIGN (decl)); 1623 return true; 1624#elif defined ASM_OUTPUT_ALIGNED_COMMON 1625 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl)); 1626 return true; 1627#else 1628 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded); 1629 return false; 1630#endif 1631} 1632 1633/* A noswitch_section_callback for tls_comm_section. */ 1634 1635static bool 1636emit_tls_common (tree decl ATTRIBUTE_UNUSED, 1637 const char *name ATTRIBUTE_UNUSED, 1638 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED, 1639 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED) 1640{ 1641#ifdef ASM_OUTPUT_TLS_COMMON 1642 ASM_OUTPUT_TLS_COMMON (asm_out_file, decl, name, size); 1643 return true; 1644#else 1645 sorry ("thread-local COMMON data not implemented"); 1646 return true; 1647#endif 1648} 1649 1650/* Assemble DECL given that it belongs in SECTION_NOSWITCH section SECT. 1651 NAME is the name of DECL's SYMBOL_REF. */ 1652 1653static void 1654assemble_noswitch_variable (tree decl, const char *name, section *sect) 1655{ 1656 unsigned HOST_WIDE_INT size, rounded; 1657 1658 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1); 1659 rounded = size; 1660 1661 /* Don't allocate zero bytes of common, 1662 since that means "undefined external" in the linker. */ 1663 if (size == 0) 1664 rounded = 1; 1665 1666 /* Round size up to multiple of BIGGEST_ALIGNMENT bits 1667 so that each uninitialized object starts on such a boundary. */ 1668 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1; 1669 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT) 1670 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT)); 1671 1672 if (!sect->noswitch.callback (decl, name, size, rounded) 1673 && (unsigned HOST_WIDE_INT) DECL_ALIGN_UNIT (decl) > rounded) 1674 warning (0, "requested alignment for %q+D is greater than " 1675 "implemented alignment of %wu", decl, rounded); 1676} 1677 1678/* A subroutine of assemble_variable. Output the label and contents of 1679 DECL, whose address is a SYMBOL_REF with name NAME. DONT_OUTPUT_DATA 1680 is as for assemble_variable. */ 1681 1682static void 1683assemble_variable_contents (tree decl, const char *name, 1684 bool dont_output_data) 1685{ 1686 /* Do any machine/system dependent processing of the object. */ 1687#ifdef ASM_DECLARE_OBJECT_NAME 1688 last_assemble_variable_decl = decl; 1689 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl); 1690#else 1691 /* Standard thing is just output label for the object. */ 1692 ASM_OUTPUT_LABEL (asm_out_file, name); 1693#endif /* ASM_DECLARE_OBJECT_NAME */ 1694 1695 if (!dont_output_data) 1696 { 1697 if (DECL_INITIAL (decl) 1698 && DECL_INITIAL (decl) != error_mark_node 1699 && !initializer_zerop (DECL_INITIAL (decl))) 1700 /* Output the actual data. */ 1701 output_constant (DECL_INITIAL (decl), 1702 tree_low_cst (DECL_SIZE_UNIT (decl), 1), 1703 DECL_ALIGN (decl)); 1704 else 1705 /* Leave space for it. */ 1706 assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1)); 1707 } 1708} 1709 1710/* Assemble everything that is needed for a variable or function declaration. 1711 Not used for automatic variables, and not used for function definitions. 1712 Should not be called for variables of incomplete structure type. 1713 1714 TOP_LEVEL is nonzero if this variable has file scope. 1715 AT_END is nonzero if this is the special handling, at end of compilation, 1716 to define things that have had only tentative definitions. 1717 DONT_OUTPUT_DATA if nonzero means don't actually output the 1718 initial value (that will be done by the caller). */ 1719 1720void 1721assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED, 1722 int at_end ATTRIBUTE_UNUSED, int dont_output_data) 1723{ 1724 const char *name; 1725 rtx decl_rtl, symbol; 1726 section *sect; 1727 1728 if (lang_hooks.decls.prepare_assemble_variable) 1729 lang_hooks.decls.prepare_assemble_variable (decl); 1730 1731 last_assemble_variable_decl = 0; 1732 1733 /* Normally no need to say anything here for external references, 1734 since assemble_external is called by the language-specific code 1735 when a declaration is first seen. */ 1736 1737 if (DECL_EXTERNAL (decl)) 1738 return; 1739 1740 /* Output no assembler code for a function declaration. 1741 Only definitions of functions output anything. */ 1742 1743 if (TREE_CODE (decl) == FUNCTION_DECL) 1744 return; 1745 1746 /* Do nothing for global register variables. */ 1747 if (DECL_RTL_SET_P (decl) && REG_P (DECL_RTL (decl))) 1748 { 1749 TREE_ASM_WRITTEN (decl) = 1; 1750 return; 1751 } 1752 1753 /* If type was incomplete when the variable was declared, 1754 see if it is complete now. */ 1755 1756 if (DECL_SIZE (decl) == 0) 1757 layout_decl (decl, 0); 1758 1759 /* Still incomplete => don't allocate it; treat the tentative defn 1760 (which is what it must have been) as an `extern' reference. */ 1761 1762 if (!dont_output_data && DECL_SIZE (decl) == 0) 1763 { 1764 error ("storage size of %q+D isn%'t known", decl); 1765 TREE_ASM_WRITTEN (decl) = 1; 1766 return; 1767 } 1768 1769 /* The first declaration of a variable that comes through this function 1770 decides whether it is global (in C, has external linkage) 1771 or local (in C, has internal linkage). So do nothing more 1772 if this function has already run. */ 1773 1774 if (TREE_ASM_WRITTEN (decl)) 1775 return; 1776 1777 /* Make sure targetm.encode_section_info is invoked before we set 1778 ASM_WRITTEN. */ 1779 decl_rtl = DECL_RTL (decl); 1780 1781 TREE_ASM_WRITTEN (decl) = 1; 1782 1783 /* Do no output if -fsyntax-only. */ 1784 if (flag_syntax_only) 1785 return; 1786 1787 app_disable (); 1788 1789 if (! dont_output_data 1790 && ! host_integerp (DECL_SIZE_UNIT (decl), 1)) 1791 { 1792 error ("size of variable %q+D is too large", decl); 1793 return; 1794 } 1795 1796 gcc_assert (MEM_P (decl_rtl)); 1797 gcc_assert (GET_CODE (XEXP (decl_rtl, 0)) == SYMBOL_REF); 1798 symbol = XEXP (decl_rtl, 0); 1799 name = XSTR (symbol, 0); 1800 if (TREE_PUBLIC (decl) && DECL_NAME (decl)) 1801 notice_global_symbol (decl); 1802 1803 /* Compute the alignment of this data. */ 1804 1805 align_variable (decl, dont_output_data); 1806 set_mem_align (decl_rtl, DECL_ALIGN (decl)); 1807 1808 if (TREE_PUBLIC (decl)) 1809 maybe_assemble_visibility (decl); 1810 1811 if (DECL_PRESERVE_P (decl)) 1812 targetm.asm_out.mark_decl_preserved (name); 1813 1814 /* First make the assembler name(s) global if appropriate. */ 1815 sect = get_variable_section (decl, false); 1816 if (TREE_PUBLIC (decl) 1817 && DECL_NAME (decl) 1818 && (sect->common.flags & SECTION_COMMON) == 0) 1819 globalize_decl (decl); 1820 1821 /* Output any data that we will need to use the address of. */ 1822 if (DECL_INITIAL (decl) && DECL_INITIAL (decl) != error_mark_node) 1823 output_addressed_constants (DECL_INITIAL (decl)); 1824 1825 /* dbxout.c needs to know this. */ 1826 if (sect && (sect->common.flags & SECTION_CODE) != 0) 1827 DECL_IN_TEXT_SECTION (decl) = 1; 1828 1829 /* If the decl is part of an object_block, make sure that the decl 1830 has been positioned within its block, but do not write out its 1831 definition yet. output_object_blocks will do that later. */ 1832 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol)) 1833 { 1834 gcc_assert (!dont_output_data); 1835 place_block_symbol (symbol); 1836 } 1837 else if (SECTION_STYLE (sect) == SECTION_NOSWITCH) 1838 assemble_noswitch_variable (decl, name, sect); 1839 else 1840 { 1841 switch_to_section (sect); 1842 if (DECL_ALIGN (decl) > BITS_PER_UNIT) 1843 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (DECL_ALIGN_UNIT (decl))); 1844 assemble_variable_contents (decl, name, dont_output_data); 1845 } 1846} 1847 1848/* Return 1 if type TYPE contains any pointers. */ 1849 1850static int 1851contains_pointers_p (tree type) 1852{ 1853 switch (TREE_CODE (type)) 1854 { 1855 case POINTER_TYPE: 1856 case REFERENCE_TYPE: 1857 /* I'm not sure whether OFFSET_TYPE needs this treatment, 1858 so I'll play safe and return 1. */ 1859 case OFFSET_TYPE: 1860 return 1; 1861 1862 case RECORD_TYPE: 1863 case UNION_TYPE: 1864 case QUAL_UNION_TYPE: 1865 { 1866 tree fields; 1867 /* For a type that has fields, see if the fields have pointers. */ 1868 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields)) 1869 if (TREE_CODE (fields) == FIELD_DECL 1870 && contains_pointers_p (TREE_TYPE (fields))) 1871 return 1; 1872 return 0; 1873 } 1874 1875 case ARRAY_TYPE: 1876 /* An array type contains pointers if its element type does. */ 1877 return contains_pointers_p (TREE_TYPE (type)); 1878 1879 default: 1880 return 0; 1881 } 1882} 1883 1884/* In unit-at-a-time mode, we delay assemble_external processing until 1885 the compilation unit is finalized. This is the best we can do for 1886 right now (i.e. stage 3 of GCC 4.0) - the right thing is to delay 1887 it all the way to final. See PR 17982 for further discussion. */ 1888static GTY(()) tree pending_assemble_externals; 1889 1890#ifdef ASM_OUTPUT_EXTERNAL 1891/* True if DECL is a function decl for which no out-of-line copy exists. 1892 It is assumed that DECL's assembler name has been set. */ 1893 1894static bool 1895incorporeal_function_p (tree decl) 1896{ 1897 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl)) 1898 { 1899 const char *name; 1900 1901 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL 1902 && DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA) 1903 return true; 1904 1905 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)); 1906 if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0) 1907 return true; 1908 } 1909 return false; 1910} 1911 1912/* Actually do the tests to determine if this is necessary, and invoke 1913 ASM_OUTPUT_EXTERNAL. */ 1914static void 1915assemble_external_real (tree decl) 1916{ 1917 rtx rtl = DECL_RTL (decl); 1918 1919 if (MEM_P (rtl) && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF 1920 && !SYMBOL_REF_USED (XEXP (rtl, 0)) 1921 && !incorporeal_function_p (decl)) 1922 { 1923 /* Some systems do require some output. */ 1924 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1; 1925 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0)); 1926 } 1927} 1928#endif 1929 1930void 1931process_pending_assemble_externals (void) 1932{ 1933#ifdef ASM_OUTPUT_EXTERNAL 1934 tree list; 1935 for (list = pending_assemble_externals; list; list = TREE_CHAIN (list)) 1936 assemble_external_real (TREE_VALUE (list)); 1937 1938 pending_assemble_externals = 0; 1939#endif 1940} 1941 1942/* Output something to declare an external symbol to the assembler. 1943 (Most assemblers don't need this, so we normally output nothing.) 1944 Do nothing if DECL is not external. */ 1945 1946void 1947assemble_external (tree decl ATTRIBUTE_UNUSED) 1948{ 1949 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the 1950 main body of this code is only rarely exercised. To provide some 1951 testing, on all platforms, we make sure that the ASM_OUT_FILE is 1952 open. If it's not, we should not be calling this function. */ 1953 gcc_assert (asm_out_file); 1954 1955#ifdef ASM_OUTPUT_EXTERNAL 1956 if (!DECL_P (decl) || !DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl)) 1957 return; 1958 1959 /* We want to output external symbols at very last to check if they 1960 are references or not. */ 1961 pending_assemble_externals = tree_cons (0, decl, 1962 pending_assemble_externals); 1963#endif 1964} 1965 1966/* Similar, for calling a library function FUN. */ 1967 1968void 1969assemble_external_libcall (rtx fun) 1970{ 1971 /* Declare library function name external when first used, if nec. */ 1972 if (! SYMBOL_REF_USED (fun)) 1973 { 1974 SYMBOL_REF_USED (fun) = 1; 1975 targetm.asm_out.external_libcall (fun); 1976 } 1977} 1978 1979/* Assemble a label named NAME. */ 1980 1981void 1982assemble_label (const char *name) 1983{ 1984 ASM_OUTPUT_LABEL (asm_out_file, name); 1985} 1986 1987/* Set the symbol_referenced flag for ID. */ 1988void 1989mark_referenced (tree id) 1990{ 1991 TREE_SYMBOL_REFERENCED (id) = 1; 1992} 1993 1994/* Set the symbol_referenced flag for DECL and notify callgraph. */ 1995void 1996mark_decl_referenced (tree decl) 1997{ 1998 if (TREE_CODE (decl) == FUNCTION_DECL) 1999 { 2000 /* Extern inline functions don't become needed when referenced. 2001 If we know a method will be emitted in other TU and no new 2002 functions can be marked reachable, just use the external 2003 definition. */ 2004 struct cgraph_node *node = cgraph_node (decl); 2005 if (!DECL_EXTERNAL (decl) 2006 && (!node->local.vtable_method || !cgraph_global_info_ready 2007 || !node->local.finalized)) 2008 cgraph_mark_needed_node (node); 2009 } 2010 else if (TREE_CODE (decl) == VAR_DECL) 2011 { 2012 struct cgraph_varpool_node *node = cgraph_varpool_node (decl); 2013 cgraph_varpool_mark_needed_node (node); 2014 /* C++ frontend use mark_decl_references to force COMDAT variables 2015 to be output that might appear dead otherwise. */ 2016 node->force_output = true; 2017 } 2018 /* else do nothing - we can get various sorts of CST nodes here, 2019 which do not need to be marked. */ 2020} 2021 2022 2023/* Follow the IDENTIFIER_TRANSPARENT_ALIAS chain starting at *ALIAS 2024 until we find an identifier that is not itself a transparent alias. 2025 Modify the alias passed to it by reference (and all aliases on the 2026 way to the ultimate target), such that they do not have to be 2027 followed again, and return the ultimate target of the alias 2028 chain. */ 2029 2030static inline tree 2031ultimate_transparent_alias_target (tree *alias) 2032{ 2033 tree target = *alias; 2034 2035 if (IDENTIFIER_TRANSPARENT_ALIAS (target)) 2036 { 2037 gcc_assert (TREE_CHAIN (target)); 2038 target = ultimate_transparent_alias_target (&TREE_CHAIN (target)); 2039 gcc_assert (! IDENTIFIER_TRANSPARENT_ALIAS (target) 2040 && ! TREE_CHAIN (target)); 2041 *alias = target; 2042 } 2043 2044 return target; 2045} 2046 2047/* Output to FILE (an assembly file) a reference to NAME. If NAME 2048 starts with a *, the rest of NAME is output verbatim. Otherwise 2049 NAME is transformed in a target-specific way (usually by the 2050 addition of an underscore). */ 2051 2052void 2053assemble_name_raw (FILE *file, const char *name) 2054{ 2055 if (name[0] == '*') 2056 fputs (&name[1], file); 2057 else 2058 ASM_OUTPUT_LABELREF (file, name); 2059} 2060 2061/* Like assemble_name_raw, but should be used when NAME might refer to 2062 an entity that is also represented as a tree (like a function or 2063 variable). If NAME does refer to such an entity, that entity will 2064 be marked as referenced. */ 2065 2066void 2067assemble_name (FILE *file, const char *name) 2068{ 2069 const char *real_name; 2070 tree id; 2071 2072 real_name = targetm.strip_name_encoding (name); 2073 2074 id = maybe_get_identifier (real_name); 2075 if (id) 2076 { 2077 tree id_orig = id; 2078 2079 mark_referenced (id); 2080 ultimate_transparent_alias_target (&id); 2081 if (id != id_orig) 2082 name = IDENTIFIER_POINTER (id); 2083 gcc_assert (! TREE_CHAIN (id)); 2084 } 2085 2086 assemble_name_raw (file, name); 2087} 2088 2089/* Allocate SIZE bytes writable static space with a gensym name 2090 and return an RTX to refer to its address. */ 2091 2092rtx 2093assemble_static_space (unsigned HOST_WIDE_INT size) 2094{ 2095 char name[12]; 2096 const char *namestring; 2097 rtx x; 2098 2099 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno); 2100 ++const_labelno; 2101 namestring = ggc_strdup (name); 2102 2103 x = gen_rtx_SYMBOL_REF (Pmode, namestring); 2104 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL; 2105 2106#ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL 2107 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size, 2108 BIGGEST_ALIGNMENT); 2109#else 2110#ifdef ASM_OUTPUT_ALIGNED_LOCAL 2111 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT); 2112#else 2113 { 2114 /* Round size up to multiple of BIGGEST_ALIGNMENT bits 2115 so that each uninitialized object starts on such a boundary. */ 2116 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */ 2117 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED 2118 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1) 2119 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT) 2120 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT)); 2121 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded); 2122 } 2123#endif 2124#endif 2125 return x; 2126} 2127 2128/* Assemble the static constant template for function entry trampolines. 2129 This is done at most once per compilation. 2130 Returns an RTX for the address of the template. */ 2131 2132static GTY(()) rtx initial_trampoline; 2133 2134#ifdef TRAMPOLINE_TEMPLATE 2135rtx 2136assemble_trampoline_template (void) 2137{ 2138 char label[256]; 2139 const char *name; 2140 int align; 2141 rtx symbol; 2142 2143 if (initial_trampoline) 2144 return initial_trampoline; 2145 2146 /* By default, put trampoline templates in read-only data section. */ 2147 2148#ifdef TRAMPOLINE_SECTION 2149 switch_to_section (TRAMPOLINE_SECTION); 2150#else 2151 switch_to_section (readonly_data_section); 2152#endif 2153 2154 /* Write the assembler code to define one. */ 2155 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT); 2156 if (align > 0) 2157 { 2158 ASM_OUTPUT_ALIGN (asm_out_file, align); 2159 } 2160 2161 targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0); 2162 TRAMPOLINE_TEMPLATE (asm_out_file); 2163 2164 /* Record the rtl to refer to it. */ 2165 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0); 2166 name = ggc_strdup (label); 2167 symbol = gen_rtx_SYMBOL_REF (Pmode, name); 2168 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL; 2169 2170 initial_trampoline = gen_rtx_MEM (BLKmode, symbol); 2171 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT); 2172 2173 return initial_trampoline; 2174} 2175#endif 2176 2177/* A and B are either alignments or offsets. Return the minimum alignment 2178 that may be assumed after adding the two together. */ 2179 2180static inline unsigned 2181min_align (unsigned int a, unsigned int b) 2182{ 2183 return (a | b) & -(a | b); 2184} 2185 2186/* Return the assembler directive for creating a given kind of integer 2187 object. SIZE is the number of bytes in the object and ALIGNED_P 2188 indicates whether it is known to be aligned. Return NULL if the 2189 assembly dialect has no such directive. 2190 2191 The returned string should be printed at the start of a new line and 2192 be followed immediately by the object's initial value. */ 2193 2194const char * 2195integer_asm_op (int size, int aligned_p) 2196{ 2197 struct asm_int_op *ops; 2198 2199 if (aligned_p) 2200 ops = &targetm.asm_out.aligned_op; 2201 else 2202 ops = &targetm.asm_out.unaligned_op; 2203 2204 switch (size) 2205 { 2206 case 1: 2207 return targetm.asm_out.byte_op; 2208 case 2: 2209 return ops->hi; 2210 case 4: 2211 return ops->si; 2212 case 8: 2213 return ops->di; 2214 case 16: 2215 return ops->ti; 2216 default: 2217 return NULL; 2218 } 2219} 2220 2221/* Use directive OP to assemble an integer object X. Print OP at the 2222 start of the line, followed immediately by the value of X. */ 2223 2224void 2225assemble_integer_with_op (const char *op, rtx x) 2226{ 2227 fputs (op, asm_out_file); 2228 output_addr_const (asm_out_file, x); 2229 fputc ('\n', asm_out_file); 2230} 2231 2232/* The default implementation of the asm_out.integer target hook. */ 2233 2234bool 2235default_assemble_integer (rtx x ATTRIBUTE_UNUSED, 2236 unsigned int size ATTRIBUTE_UNUSED, 2237 int aligned_p ATTRIBUTE_UNUSED) 2238{ 2239 const char *op = integer_asm_op (size, aligned_p); 2240 /* Avoid GAS bugs for large values. Specifically negative values whose 2241 absolute value fits in a bfd_vma, but not in a bfd_signed_vma. */ 2242 if (size > UNITS_PER_WORD && size > POINTER_SIZE / BITS_PER_UNIT) 2243 return false; 2244 return op && (assemble_integer_with_op (op, x), true); 2245} 2246 2247/* Assemble the integer constant X into an object of SIZE bytes. ALIGN is 2248 the alignment of the integer in bits. Return 1 if we were able to output 2249 the constant, otherwise 0. We must be able to output the constant, 2250 if FORCE is nonzero. */ 2251 2252bool 2253assemble_integer (rtx x, unsigned int size, unsigned int align, int force) 2254{ 2255 int aligned_p; 2256 2257 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT)); 2258 2259 /* See if the target hook can handle this kind of object. */ 2260 if (targetm.asm_out.integer (x, size, aligned_p)) 2261 return true; 2262 2263 /* If the object is a multi-byte one, try splitting it up. Split 2264 it into words it if is multi-word, otherwise split it into bytes. */ 2265 if (size > 1) 2266 { 2267 enum machine_mode omode, imode; 2268 unsigned int subalign; 2269 unsigned int subsize, i; 2270 2271 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1; 2272 subalign = MIN (align, subsize * BITS_PER_UNIT); 2273 omode = mode_for_size (subsize * BITS_PER_UNIT, MODE_INT, 0); 2274 imode = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0); 2275 2276 for (i = 0; i < size; i += subsize) 2277 { 2278 rtx partial = simplify_subreg (omode, x, imode, i); 2279 if (!partial || !assemble_integer (partial, subsize, subalign, 0)) 2280 break; 2281 } 2282 if (i == size) 2283 return true; 2284 2285 /* If we've printed some of it, but not all of it, there's no going 2286 back now. */ 2287 gcc_assert (!i); 2288 } 2289 2290 gcc_assert (!force); 2291 2292 return false; 2293} 2294 2295void 2296assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align) 2297{ 2298 long data[4] = {0, 0, 0, 0}; 2299 int i; 2300 int bitsize, nelts, nunits, units_per; 2301 2302 /* This is hairy. We have a quantity of known size. real_to_target 2303 will put it into an array of *host* longs, 32 bits per element 2304 (even if long is more than 32 bits). We need to determine the 2305 number of array elements that are occupied (nelts) and the number 2306 of *target* min-addressable units that will be occupied in the 2307 object file (nunits). We cannot assume that 32 divides the 2308 mode's bitsize (size * BITS_PER_UNIT) evenly. 2309 2310 size * BITS_PER_UNIT is used here to make sure that padding bits 2311 (which might appear at either end of the value; real_to_target 2312 will include the padding bits in its output array) are included. */ 2313 2314 nunits = GET_MODE_SIZE (mode); 2315 bitsize = nunits * BITS_PER_UNIT; 2316 nelts = CEIL (bitsize, 32); 2317 units_per = 32 / BITS_PER_UNIT; 2318 2319 real_to_target (data, &d, mode); 2320 2321 /* Put out the first word with the specified alignment. */ 2322 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1); 2323 nunits -= units_per; 2324 2325 /* Subsequent words need only 32-bit alignment. */ 2326 align = min_align (align, 32); 2327 2328 for (i = 1; i < nelts; i++) 2329 { 2330 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1); 2331 nunits -= units_per; 2332 } 2333} 2334 2335/* Given an expression EXP with a constant value, 2336 reduce it to the sum of an assembler symbol and an integer. 2337 Store them both in the structure *VALUE. 2338 EXP must be reducible. */ 2339 2340struct addr_const GTY(()) 2341{ 2342 rtx base; 2343 HOST_WIDE_INT offset; 2344}; 2345 2346static void 2347decode_addr_const (tree exp, struct addr_const *value) 2348{ 2349 tree target = TREE_OPERAND (exp, 0); 2350 int offset = 0; 2351 rtx x; 2352 2353 while (1) 2354 { 2355 if (TREE_CODE (target) == COMPONENT_REF 2356 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0)) 2357 2358 { 2359 offset += int_byte_position (TREE_OPERAND (target, 1)); 2360 target = TREE_OPERAND (target, 0); 2361 } 2362 else if (TREE_CODE (target) == ARRAY_REF 2363 || TREE_CODE (target) == ARRAY_RANGE_REF) 2364 { 2365 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1) 2366 * tree_low_cst (TREE_OPERAND (target, 1), 0)); 2367 target = TREE_OPERAND (target, 0); 2368 } 2369 else 2370 break; 2371 } 2372 2373 switch (TREE_CODE (target)) 2374 { 2375 case VAR_DECL: 2376 case FUNCTION_DECL: 2377 x = DECL_RTL (target); 2378 break; 2379 2380 case LABEL_DECL: 2381 x = gen_rtx_MEM (FUNCTION_MODE, 2382 gen_rtx_LABEL_REF (Pmode, force_label_rtx (target))); 2383 break; 2384 2385 case REAL_CST: 2386 case STRING_CST: 2387 case COMPLEX_CST: 2388 case CONSTRUCTOR: 2389 case INTEGER_CST: 2390 x = output_constant_def (target, 1); 2391 break; 2392 2393 default: 2394 gcc_unreachable (); 2395 } 2396 2397 gcc_assert (MEM_P (x)); 2398 x = XEXP (x, 0); 2399 2400 value->base = x; 2401 value->offset = offset; 2402} 2403 2404/* Uniquize all constants that appear in memory. 2405 Each constant in memory thus far output is recorded 2406 in `const_desc_table'. */ 2407 2408struct constant_descriptor_tree GTY(()) 2409{ 2410 /* A MEM for the constant. */ 2411 rtx rtl; 2412 2413 /* The value of the constant. */ 2414 tree value; 2415 2416 /* Hash of value. Computing the hash from value each time 2417 hashfn is called can't work properly, as that means recursive 2418 use of the hash table during hash table expansion. */ 2419 hashval_t hash; 2420}; 2421 2422static GTY((param_is (struct constant_descriptor_tree))) 2423 htab_t const_desc_htab; 2424 2425static struct constant_descriptor_tree * build_constant_desc (tree); 2426static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int); 2427 2428/* Compute a hash code for a constant expression. */ 2429 2430static hashval_t 2431const_desc_hash (const void *ptr) 2432{ 2433 return ((struct constant_descriptor_tree *)ptr)->hash; 2434} 2435 2436static hashval_t 2437const_hash_1 (const tree exp) 2438{ 2439 const char *p; 2440 hashval_t hi; 2441 int len, i; 2442 enum tree_code code = TREE_CODE (exp); 2443 2444 /* Either set P and LEN to the address and len of something to hash and 2445 exit the switch or return a value. */ 2446 2447 switch (code) 2448 { 2449 case INTEGER_CST: 2450 p = (char *) &TREE_INT_CST (exp); 2451 len = sizeof TREE_INT_CST (exp); 2452 break; 2453 2454 case REAL_CST: 2455 return real_hash (TREE_REAL_CST_PTR (exp)); 2456 2457 case STRING_CST: 2458 p = TREE_STRING_POINTER (exp); 2459 len = TREE_STRING_LENGTH (exp); 2460 break; 2461 2462 case COMPLEX_CST: 2463 return (const_hash_1 (TREE_REALPART (exp)) * 5 2464 + const_hash_1 (TREE_IMAGPART (exp))); 2465 2466 case CONSTRUCTOR: 2467 { 2468 unsigned HOST_WIDE_INT idx; 2469 tree value; 2470 2471 hi = 5 + int_size_in_bytes (TREE_TYPE (exp)); 2472 2473 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, value) 2474 if (value) 2475 hi = hi * 603 + const_hash_1 (value); 2476 2477 return hi; 2478 } 2479 2480 case ADDR_EXPR: 2481 case FDESC_EXPR: 2482 { 2483 struct addr_const value; 2484 2485 decode_addr_const (exp, &value); 2486 switch (GET_CODE (value.base)) 2487 { 2488 case SYMBOL_REF: 2489 /* Don't hash the address of the SYMBOL_REF; 2490 only use the offset and the symbol name. */ 2491 hi = value.offset; 2492 p = XSTR (value.base, 0); 2493 for (i = 0; p[i] != 0; i++) 2494 hi = ((hi * 613) + (unsigned) (p[i])); 2495 break; 2496 2497 case LABEL_REF: 2498 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13; 2499 break; 2500 2501 default: 2502 gcc_unreachable (); 2503 } 2504 } 2505 return hi; 2506 2507 case PLUS_EXPR: 2508 case MINUS_EXPR: 2509 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9 2510 + const_hash_1 (TREE_OPERAND (exp, 1))); 2511 2512 case NOP_EXPR: 2513 case CONVERT_EXPR: 2514 case NON_LVALUE_EXPR: 2515 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2; 2516 2517 default: 2518 /* A language specific constant. Just hash the code. */ 2519 return code; 2520 } 2521 2522 /* Compute hashing function. */ 2523 hi = len; 2524 for (i = 0; i < len; i++) 2525 hi = ((hi * 613) + (unsigned) (p[i])); 2526 2527 return hi; 2528} 2529 2530/* Wrapper of compare_constant, for the htab interface. */ 2531static int 2532const_desc_eq (const void *p1, const void *p2) 2533{ 2534 const struct constant_descriptor_tree *c1 = p1; 2535 const struct constant_descriptor_tree *c2 = p2; 2536 if (c1->hash != c2->hash) 2537 return 0; 2538 return compare_constant (c1->value, c2->value); 2539} 2540 2541/* Compare t1 and t2, and return 1 only if they are known to result in 2542 the same bit pattern on output. */ 2543 2544static int 2545compare_constant (const tree t1, const tree t2) 2546{ 2547 enum tree_code typecode; 2548 2549 if (t1 == NULL_TREE) 2550 return t2 == NULL_TREE; 2551 if (t2 == NULL_TREE) 2552 return 0; 2553 2554 if (TREE_CODE (t1) != TREE_CODE (t2)) 2555 return 0; 2556 2557 switch (TREE_CODE (t1)) 2558 { 2559 case INTEGER_CST: 2560 /* Integer constants are the same only if the same width of type. */ 2561 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2))) 2562 return 0; 2563 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))) 2564 return 0; 2565 return tree_int_cst_equal (t1, t2); 2566 2567 case REAL_CST: 2568 /* Real constants are the same only if the same width of type. */ 2569 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2))) 2570 return 0; 2571 2572 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2)); 2573 2574 case STRING_CST: 2575 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))) 2576 return 0; 2577 2578 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2) 2579 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2), 2580 TREE_STRING_LENGTH (t1))); 2581 2582 case COMPLEX_CST: 2583 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2)) 2584 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2))); 2585 2586 case CONSTRUCTOR: 2587 { 2588 VEC(constructor_elt, gc) *v1, *v2; 2589 unsigned HOST_WIDE_INT idx; 2590 2591 typecode = TREE_CODE (TREE_TYPE (t1)); 2592 if (typecode != TREE_CODE (TREE_TYPE (t2))) 2593 return 0; 2594 2595 if (typecode == ARRAY_TYPE) 2596 { 2597 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1)); 2598 /* For arrays, check that the sizes all match. */ 2599 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)) 2600 || size_1 == -1 2601 || size_1 != int_size_in_bytes (TREE_TYPE (t2))) 2602 return 0; 2603 } 2604 else 2605 { 2606 /* For record and union constructors, require exact type 2607 equality. */ 2608 if (TREE_TYPE (t1) != TREE_TYPE (t2)) 2609 return 0; 2610 } 2611 2612 v1 = CONSTRUCTOR_ELTS (t1); 2613 v2 = CONSTRUCTOR_ELTS (t2); 2614 if (VEC_length (constructor_elt, v1) 2615 != VEC_length (constructor_elt, v2)) 2616 return 0; 2617 2618 for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx) 2619 { 2620 constructor_elt *c1 = VEC_index (constructor_elt, v1, idx); 2621 constructor_elt *c2 = VEC_index (constructor_elt, v2, idx); 2622 2623 /* Check that each value is the same... */ 2624 if (!compare_constant (c1->value, c2->value)) 2625 return 0; 2626 /* ... and that they apply to the same fields! */ 2627 if (typecode == ARRAY_TYPE) 2628 { 2629 if (!compare_constant (c1->index, c2->index)) 2630 return 0; 2631 } 2632 else 2633 { 2634 if (c1->index != c2->index) 2635 return 0; 2636 } 2637 } 2638 2639 return 1; 2640 } 2641 2642 case ADDR_EXPR: 2643 case FDESC_EXPR: 2644 { 2645 struct addr_const value1, value2; 2646 2647 decode_addr_const (t1, &value1); 2648 decode_addr_const (t2, &value2); 2649 return (value1.offset == value2.offset 2650 && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0); 2651 } 2652 2653 case PLUS_EXPR: 2654 case MINUS_EXPR: 2655 case RANGE_EXPR: 2656 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)) 2657 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1))); 2658 2659 case NOP_EXPR: 2660 case CONVERT_EXPR: 2661 case NON_LVALUE_EXPR: 2662 case VIEW_CONVERT_EXPR: 2663 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)); 2664 2665 default: 2666 { 2667 tree nt1, nt2; 2668 nt1 = lang_hooks.expand_constant (t1); 2669 nt2 = lang_hooks.expand_constant (t2); 2670 if (nt1 != t1 || nt2 != t2) 2671 return compare_constant (nt1, nt2); 2672 else 2673 return 0; 2674 } 2675 } 2676 2677 gcc_unreachable (); 2678} 2679 2680/* Make a copy of the whole tree structure for a constant. This 2681 handles the same types of nodes that compare_constant handles. */ 2682 2683static tree 2684copy_constant (tree exp) 2685{ 2686 switch (TREE_CODE (exp)) 2687 { 2688 case ADDR_EXPR: 2689 /* For ADDR_EXPR, we do not want to copy the decl whose address 2690 is requested. We do want to copy constants though. */ 2691 if (CONSTANT_CLASS_P (TREE_OPERAND (exp, 0))) 2692 return build1 (TREE_CODE (exp), TREE_TYPE (exp), 2693 copy_constant (TREE_OPERAND (exp, 0))); 2694 else 2695 return copy_node (exp); 2696 2697 case INTEGER_CST: 2698 case REAL_CST: 2699 case STRING_CST: 2700 return copy_node (exp); 2701 2702 case COMPLEX_CST: 2703 return build_complex (TREE_TYPE (exp), 2704 copy_constant (TREE_REALPART (exp)), 2705 copy_constant (TREE_IMAGPART (exp))); 2706 2707 case PLUS_EXPR: 2708 case MINUS_EXPR: 2709 return build2 (TREE_CODE (exp), TREE_TYPE (exp), 2710 copy_constant (TREE_OPERAND (exp, 0)), 2711 copy_constant (TREE_OPERAND (exp, 1))); 2712 2713 case NOP_EXPR: 2714 case CONVERT_EXPR: 2715 case NON_LVALUE_EXPR: 2716 case VIEW_CONVERT_EXPR: 2717 return build1 (TREE_CODE (exp), TREE_TYPE (exp), 2718 copy_constant (TREE_OPERAND (exp, 0))); 2719 2720 case CONSTRUCTOR: 2721 { 2722 tree copy = copy_node (exp); 2723 VEC(constructor_elt, gc) *v; 2724 unsigned HOST_WIDE_INT idx; 2725 tree purpose, value; 2726 2727 v = VEC_alloc(constructor_elt, gc, VEC_length(constructor_elt, 2728 CONSTRUCTOR_ELTS (exp))); 2729 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (exp), idx, purpose, value) 2730 { 2731 constructor_elt *ce = VEC_quick_push (constructor_elt, v, NULL); 2732 ce->index = purpose; 2733 ce->value = copy_constant (value); 2734 } 2735 CONSTRUCTOR_ELTS (copy) = v; 2736 return copy; 2737 } 2738 2739 default: 2740 { 2741 tree t = lang_hooks.expand_constant (exp); 2742 2743 gcc_assert (t != exp); 2744 return copy_constant (t); 2745 } 2746 } 2747} 2748 2749/* Return the alignment of constant EXP in bits. */ 2750 2751static unsigned int 2752get_constant_alignment (tree exp) 2753{ 2754 unsigned int align; 2755 2756 align = TYPE_ALIGN (TREE_TYPE (exp)); 2757#ifdef CONSTANT_ALIGNMENT 2758 align = CONSTANT_ALIGNMENT (exp, align); 2759#endif 2760 return align; 2761} 2762 2763/* Return the section into which constant EXP should be placed. */ 2764 2765static section * 2766get_constant_section (tree exp) 2767{ 2768 if (IN_NAMED_SECTION (exp)) 2769 return get_named_section (exp, NULL, compute_reloc_for_constant (exp)); 2770 else 2771 return targetm.asm_out.select_section (exp, 2772 compute_reloc_for_constant (exp), 2773 get_constant_alignment (exp)); 2774} 2775 2776/* Return the size of constant EXP in bytes. */ 2777 2778static HOST_WIDE_INT 2779get_constant_size (tree exp) 2780{ 2781 HOST_WIDE_INT size; 2782 2783 size = int_size_in_bytes (TREE_TYPE (exp)); 2784 if (TREE_CODE (exp) == STRING_CST) 2785 size = MAX (TREE_STRING_LENGTH (exp), size); 2786 return size; 2787} 2788 2789/* Subroutine of output_constant_def: 2790 No constant equal to EXP is known to have been output. 2791 Make a constant descriptor to enter EXP in the hash table. 2792 Assign the label number and construct RTL to refer to the 2793 constant's location in memory. 2794 Caller is responsible for updating the hash table. */ 2795 2796static struct constant_descriptor_tree * 2797build_constant_desc (tree exp) 2798{ 2799 rtx symbol; 2800 rtx rtl; 2801 char label[256]; 2802 int labelno; 2803 struct constant_descriptor_tree *desc; 2804 2805 desc = ggc_alloc (sizeof (*desc)); 2806 desc->value = copy_constant (exp); 2807 2808 /* Propagate marked-ness to copied constant. */ 2809 if (flag_mudflap && mf_marked_p (exp)) 2810 mf_mark (desc->value); 2811 2812 /* Create a string containing the label name, in LABEL. */ 2813 labelno = const_labelno++; 2814 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno); 2815 2816 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */ 2817 if (use_object_blocks_p ()) 2818 { 2819 section *sect = get_constant_section (exp); 2820 symbol = create_block_symbol (ggc_strdup (label), 2821 get_block_for_section (sect), -1); 2822 } 2823 else 2824 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label)); 2825 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL; 2826 SET_SYMBOL_REF_DECL (symbol, desc->value); 2827 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1; 2828 2829 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol); 2830 set_mem_attributes (rtl, exp, 1); 2831 set_mem_alias_set (rtl, 0); 2832 set_mem_alias_set (rtl, const_alias_set); 2833 2834 /* Set flags or add text to the name to record information, such as 2835 that it is a local symbol. If the name is changed, the macro 2836 ASM_OUTPUT_LABELREF will have to know how to strip this 2837 information. This call might invalidate our local variable 2838 SYMBOL; we can't use it afterward. */ 2839 2840 targetm.encode_section_info (exp, rtl, true); 2841 2842 desc->rtl = rtl; 2843 2844 return desc; 2845} 2846 2847/* Return an rtx representing a reference to constant data in memory 2848 for the constant expression EXP. 2849 2850 If assembler code for such a constant has already been output, 2851 return an rtx to refer to it. 2852 Otherwise, output such a constant in memory 2853 and generate an rtx for it. 2854 2855 If DEFER is nonzero, this constant can be deferred and output only 2856 if referenced in the function after all optimizations. 2857 2858 `const_desc_table' records which constants already have label strings. */ 2859 2860rtx 2861output_constant_def (tree exp, int defer) 2862{ 2863 struct constant_descriptor_tree *desc; 2864 struct constant_descriptor_tree key; 2865 void **loc; 2866 2867 /* Look up EXP in the table of constant descriptors. If we didn't find 2868 it, create a new one. */ 2869 key.value = exp; 2870 key.hash = const_hash_1 (exp); 2871 loc = htab_find_slot_with_hash (const_desc_htab, &key, key.hash, INSERT); 2872 2873 desc = *loc; 2874 if (desc == 0) 2875 { 2876 desc = build_constant_desc (exp); 2877 desc->hash = key.hash; 2878 *loc = desc; 2879 } 2880 2881 maybe_output_constant_def_contents (desc, defer); 2882 return desc->rtl; 2883} 2884 2885/* Subroutine of output_constant_def: Decide whether or not we need to 2886 output the constant DESC now, and if so, do it. */ 2887static void 2888maybe_output_constant_def_contents (struct constant_descriptor_tree *desc, 2889 int defer) 2890{ 2891 rtx symbol = XEXP (desc->rtl, 0); 2892 tree exp = desc->value; 2893 2894 if (flag_syntax_only) 2895 return; 2896 2897 if (TREE_ASM_WRITTEN (exp)) 2898 /* Already output; don't do it again. */ 2899 return; 2900 2901 /* We can always defer constants as long as the context allows 2902 doing so. */ 2903 if (defer) 2904 { 2905 /* Increment n_deferred_constants if it exists. It needs to be at 2906 least as large as the number of constants actually referred to 2907 by the function. If it's too small we'll stop looking too early 2908 and fail to emit constants; if it's too large we'll only look 2909 through the entire function when we could have stopped earlier. */ 2910 if (cfun) 2911 n_deferred_constants++; 2912 return; 2913 } 2914 2915 output_constant_def_contents (symbol); 2916} 2917 2918/* Subroutine of output_constant_def_contents. Output the definition 2919 of constant EXP, which is pointed to by label LABEL. ALIGN is the 2920 constant's alignment in bits. */ 2921 2922static void 2923assemble_constant_contents (tree exp, const char *label, unsigned int align) 2924{ 2925 HOST_WIDE_INT size; 2926 2927 size = get_constant_size (exp); 2928 2929 /* Do any machine/system dependent processing of the constant. */ 2930#ifdef ASM_DECLARE_CONSTANT_NAME 2931 ASM_DECLARE_CONSTANT_NAME (asm_out_file, label, exp, size); 2932#else 2933 /* Standard thing is just output label for the constant. */ 2934 ASM_OUTPUT_LABEL (asm_out_file, label); 2935#endif /* ASM_DECLARE_CONSTANT_NAME */ 2936 2937 /* Output the value of EXP. */ 2938 output_constant (exp, size, align); 2939} 2940 2941/* We must output the constant data referred to by SYMBOL; do so. */ 2942 2943static void 2944output_constant_def_contents (rtx symbol) 2945{ 2946 tree exp = SYMBOL_REF_DECL (symbol); 2947 unsigned int align; 2948 2949 /* Make sure any other constants whose addresses appear in EXP 2950 are assigned label numbers. */ 2951 output_addressed_constants (exp); 2952 2953 /* We are no longer deferring this constant. */ 2954 TREE_ASM_WRITTEN (exp) = 1; 2955 2956 /* If the constant is part of an object block, make sure that the 2957 decl has been positioned within its block, but do not write out 2958 its definition yet. output_object_blocks will do that later. */ 2959 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol)) 2960 place_block_symbol (symbol); 2961 else 2962 { 2963 switch_to_section (get_constant_section (exp)); 2964 align = get_constant_alignment (exp); 2965 if (align > BITS_PER_UNIT) 2966 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT)); 2967 assemble_constant_contents (exp, XSTR (symbol, 0), align); 2968 } 2969 if (flag_mudflap) 2970 mudflap_enqueue_constant (exp); 2971} 2972 2973/* Look up EXP in the table of constant descriptors. Return the rtl 2974 if it has been emitted, else null. */ 2975 2976rtx 2977lookup_constant_def (tree exp) 2978{ 2979 struct constant_descriptor_tree *desc; 2980 struct constant_descriptor_tree key; 2981 2982 key.value = exp; 2983 key.hash = const_hash_1 (exp); 2984 desc = htab_find_with_hash (const_desc_htab, &key, key.hash); 2985 2986 return (desc ? desc->rtl : NULL_RTX); 2987} 2988 2989/* Used in the hash tables to avoid outputting the same constant 2990 twice. Unlike 'struct constant_descriptor_tree', RTX constants 2991 are output once per function, not once per file. */ 2992/* ??? Only a few targets need per-function constant pools. Most 2993 can use one per-file pool. Should add a targetm bit to tell the 2994 difference. */ 2995 2996struct rtx_constant_pool GTY(()) 2997{ 2998 /* Pointers to first and last constant in pool, as ordered by offset. */ 2999 struct constant_descriptor_rtx *first; 3000 struct constant_descriptor_rtx *last; 3001 3002 /* Hash facility for making memory-constants from constant rtl-expressions. 3003 It is used on RISC machines where immediate integer arguments and 3004 constant addresses are restricted so that such constants must be stored 3005 in memory. */ 3006 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab; 3007 3008 /* Current offset in constant pool (does not include any 3009 machine-specific header). */ 3010 HOST_WIDE_INT offset; 3011}; 3012 3013struct constant_descriptor_rtx GTY((chain_next ("%h.next"))) 3014{ 3015 struct constant_descriptor_rtx *next; 3016 rtx mem; 3017 rtx sym; 3018 rtx constant; 3019 HOST_WIDE_INT offset; 3020 hashval_t hash; 3021 enum machine_mode mode; 3022 unsigned int align; 3023 int labelno; 3024 int mark; 3025}; 3026 3027/* Hash and compare functions for const_rtx_htab. */ 3028 3029static hashval_t 3030const_desc_rtx_hash (const void *ptr) 3031{ 3032 const struct constant_descriptor_rtx *desc = ptr; 3033 return desc->hash; 3034} 3035 3036static int 3037const_desc_rtx_eq (const void *a, const void *b) 3038{ 3039 const struct constant_descriptor_rtx *x = a; 3040 const struct constant_descriptor_rtx *y = b; 3041 3042 if (x->mode != y->mode) 3043 return 0; 3044 return rtx_equal_p (x->constant, y->constant); 3045} 3046 3047/* This is the worker function for const_rtx_hash, called via for_each_rtx. */ 3048 3049static int 3050const_rtx_hash_1 (rtx *xp, void *data) 3051{ 3052 unsigned HOST_WIDE_INT hwi; 3053 enum machine_mode mode; 3054 enum rtx_code code; 3055 hashval_t h, *hp; 3056 rtx x; 3057 3058 x = *xp; 3059 code = GET_CODE (x); 3060 mode = GET_MODE (x); 3061 h = (hashval_t) code * 1048573 + mode; 3062 3063 switch (code) 3064 { 3065 case CONST_INT: 3066 hwi = INTVAL (x); 3067 fold_hwi: 3068 { 3069 const int shift = sizeof (hashval_t) * CHAR_BIT; 3070 const int n = sizeof (HOST_WIDE_INT) / sizeof (hashval_t); 3071 int i; 3072 3073 h ^= (hashval_t) hwi; 3074 for (i = 1; i < n; ++i) 3075 { 3076 hwi >>= shift; 3077 h ^= (hashval_t) hwi; 3078 } 3079 } 3080 break; 3081 3082 case CONST_DOUBLE: 3083 if (mode == VOIDmode) 3084 { 3085 hwi = CONST_DOUBLE_LOW (x) ^ CONST_DOUBLE_HIGH (x); 3086 goto fold_hwi; 3087 } 3088 else 3089 h ^= real_hash (CONST_DOUBLE_REAL_VALUE (x)); 3090 break; 3091 3092 case CONST_VECTOR: 3093 { 3094 int i; 3095 for (i = XVECLEN (x, 0); i-- > 0; ) 3096 h = h * 251 + const_rtx_hash_1 (&XVECEXP (x, 0, i), data); 3097 } 3098 break; 3099 3100 case SYMBOL_REF: 3101 h ^= htab_hash_string (XSTR (x, 0)); 3102 break; 3103 3104 case LABEL_REF: 3105 h = h * 251 + CODE_LABEL_NUMBER (XEXP (x, 0)); 3106 break; 3107 3108 case UNSPEC: 3109 case UNSPEC_VOLATILE: 3110 h = h * 251 + XINT (x, 1); 3111 break; 3112 3113 default: 3114 break; 3115 } 3116 3117 hp = data; 3118 *hp = *hp * 509 + h; 3119 return 0; 3120} 3121 3122/* Compute a hash value for X, which should be a constant. */ 3123 3124static hashval_t 3125const_rtx_hash (rtx x) 3126{ 3127 hashval_t h = 0; 3128 for_each_rtx (&x, const_rtx_hash_1, &h); 3129 return h; 3130} 3131 3132 3133/* Create and return a new rtx constant pool. */ 3134 3135static struct rtx_constant_pool * 3136create_constant_pool (void) 3137{ 3138 struct rtx_constant_pool *pool; 3139 3140 pool = ggc_alloc (sizeof (struct rtx_constant_pool)); 3141 pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash, 3142 const_desc_rtx_eq, NULL); 3143 pool->first = NULL; 3144 pool->last = NULL; 3145 pool->offset = 0; 3146 return pool; 3147} 3148 3149/* Initialize constant pool hashing for a new function. */ 3150 3151void 3152init_varasm_status (struct function *f) 3153{ 3154 struct varasm_status *p; 3155 3156 p = ggc_alloc (sizeof (struct varasm_status)); 3157 f->varasm = p; 3158 3159 p->pool = create_constant_pool (); 3160 p->deferred_constants = 0; 3161} 3162 3163/* Given a MINUS expression, simplify it if both sides 3164 include the same symbol. */ 3165 3166rtx 3167simplify_subtraction (rtx x) 3168{ 3169 rtx r = simplify_rtx (x); 3170 return r ? r : x; 3171} 3172 3173/* Given a constant rtx X, make (or find) a memory constant for its value 3174 and return a MEM rtx to refer to it in memory. */ 3175 3176rtx 3177force_const_mem (enum machine_mode mode, rtx x) 3178{ 3179 struct constant_descriptor_rtx *desc, tmp; 3180 struct rtx_constant_pool *pool; 3181 char label[256]; 3182 rtx def, symbol; 3183 hashval_t hash; 3184 unsigned int align; 3185 void **slot; 3186 3187 /* If we're not allowed to drop X into the constant pool, don't. */ 3188 if (targetm.cannot_force_const_mem (x)) 3189 return NULL_RTX; 3190 3191 /* Record that this function has used a constant pool entry. */ 3192 current_function_uses_const_pool = 1; 3193 3194 /* Decide which pool to use. */ 3195 pool = (targetm.use_blocks_for_constant_p (mode, x) 3196 ? shared_constant_pool 3197 : cfun->varasm->pool); 3198 3199 /* Lookup the value in the hashtable. */ 3200 tmp.constant = x; 3201 tmp.mode = mode; 3202 hash = const_rtx_hash (x); 3203 slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT); 3204 desc = *slot; 3205 3206 /* If the constant was already present, return its memory. */ 3207 if (desc) 3208 return copy_rtx (desc->mem); 3209 3210 /* Otherwise, create a new descriptor. */ 3211 desc = ggc_alloc (sizeof (*desc)); 3212 *slot = desc; 3213 3214 /* Align the location counter as required by EXP's data type. */ 3215 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode); 3216#ifdef CONSTANT_ALIGNMENT 3217 { 3218 tree type = lang_hooks.types.type_for_mode (mode, 0); 3219 if (type != NULL_TREE) 3220 align = CONSTANT_ALIGNMENT (make_tree (type, x), align); 3221 } 3222#endif 3223 3224 pool->offset += (align / BITS_PER_UNIT) - 1; 3225 pool->offset &= ~ ((align / BITS_PER_UNIT) - 1); 3226 3227 desc->next = NULL; 3228 desc->constant = tmp.constant; 3229 desc->offset = pool->offset; 3230 desc->hash = hash; 3231 desc->mode = mode; 3232 desc->align = align; 3233 desc->labelno = const_labelno; 3234 desc->mark = 0; 3235 3236 pool->offset += GET_MODE_SIZE (mode); 3237 if (pool->last) 3238 pool->last->next = desc; 3239 else 3240 pool->first = pool->last = desc; 3241 pool->last = desc; 3242 3243 /* Create a string containing the label name, in LABEL. */ 3244 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno); 3245 ++const_labelno; 3246 3247 /* Construct the SYMBOL_REF. Make sure to mark it as belonging to 3248 the constants pool. */ 3249 if (use_object_blocks_p () && targetm.use_blocks_for_constant_p (mode, x)) 3250 { 3251 section *sect = targetm.asm_out.select_rtx_section (mode, x, align); 3252 symbol = create_block_symbol (ggc_strdup (label), 3253 get_block_for_section (sect), -1); 3254 } 3255 else 3256 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label)); 3257 desc->sym = symbol; 3258 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL; 3259 CONSTANT_POOL_ADDRESS_P (symbol) = 1; 3260 SET_SYMBOL_REF_CONSTANT (symbol, desc); 3261 3262 /* Construct the MEM. */ 3263 desc->mem = def = gen_const_mem (mode, symbol); 3264 set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1); 3265 set_mem_align (def, align); 3266 3267 /* If we're dropping a label to the constant pool, make sure we 3268 don't delete it. */ 3269 if (GET_CODE (x) == LABEL_REF) 3270 LABEL_PRESERVE_P (XEXP (x, 0)) = 1; 3271 3272 return copy_rtx (def); 3273} 3274 3275/* Given a constant pool SYMBOL_REF, return the corresponding constant. */ 3276 3277rtx 3278get_pool_constant (rtx addr) 3279{ 3280 return SYMBOL_REF_CONSTANT (addr)->constant; 3281} 3282 3283/* Given a constant pool SYMBOL_REF, return the corresponding constant 3284 and whether it has been output or not. */ 3285 3286rtx 3287get_pool_constant_mark (rtx addr, bool *pmarked) 3288{ 3289 struct constant_descriptor_rtx *desc; 3290 3291 desc = SYMBOL_REF_CONSTANT (addr); 3292 *pmarked = (desc->mark != 0); 3293 return desc->constant; 3294} 3295 3296/* Similar, return the mode. */ 3297 3298enum machine_mode 3299get_pool_mode (rtx addr) 3300{ 3301 return SYMBOL_REF_CONSTANT (addr)->mode; 3302} 3303 3304/* Return the size of the constant pool. */ 3305 3306int 3307get_pool_size (void) 3308{ 3309 return cfun->varasm->pool->offset; 3310} 3311 3312/* Worker function for output_constant_pool_1. Emit assembly for X 3313 in MODE with known alignment ALIGN. */ 3314 3315static void 3316output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align) 3317{ 3318 switch (GET_MODE_CLASS (mode)) 3319 { 3320 case MODE_FLOAT: 3321 case MODE_DECIMAL_FLOAT: 3322 { 3323 REAL_VALUE_TYPE r; 3324 3325 gcc_assert (GET_CODE (x) == CONST_DOUBLE); 3326 REAL_VALUE_FROM_CONST_DOUBLE (r, x); 3327 assemble_real (r, mode, align); 3328 break; 3329 } 3330 3331 case MODE_INT: 3332 case MODE_PARTIAL_INT: 3333 assemble_integer (x, GET_MODE_SIZE (mode), align, 1); 3334 break; 3335 3336 case MODE_VECTOR_FLOAT: 3337 case MODE_VECTOR_INT: 3338 { 3339 int i, units; 3340 enum machine_mode submode = GET_MODE_INNER (mode); 3341 unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode)); 3342 3343 gcc_assert (GET_CODE (x) == CONST_VECTOR); 3344 units = CONST_VECTOR_NUNITS (x); 3345 3346 for (i = 0; i < units; i++) 3347 { 3348 rtx elt = CONST_VECTOR_ELT (x, i); 3349 output_constant_pool_2 (submode, elt, i ? subalign : align); 3350 } 3351 } 3352 break; 3353 3354 default: 3355 gcc_unreachable (); 3356 } 3357} 3358 3359/* Worker function for output_constant_pool. Emit constant DESC, 3360 giving it ALIGN bits of alignment. */ 3361 3362static void 3363output_constant_pool_1 (struct constant_descriptor_rtx *desc, 3364 unsigned int align) 3365{ 3366 rtx x, tmp; 3367 3368 x = desc->constant; 3369 3370 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF) 3371 whose CODE_LABEL has been deleted. This can occur if a jump table 3372 is eliminated by optimization. If so, write a constant of zero 3373 instead. Note that this can also happen by turning the 3374 CODE_LABEL into a NOTE. */ 3375 /* ??? This seems completely and utterly wrong. Certainly it's 3376 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper 3377 functioning even with INSN_DELETED_P and friends. */ 3378 3379 tmp = x; 3380 switch (GET_CODE (x)) 3381 { 3382 case CONST: 3383 if (GET_CODE (XEXP (x, 0)) != PLUS 3384 || GET_CODE (XEXP (XEXP (x, 0), 0)) != LABEL_REF) 3385 break; 3386 tmp = XEXP (XEXP (x, 0), 0); 3387 /* FALLTHRU */ 3388 3389 case LABEL_REF: 3390 tmp = XEXP (x, 0); 3391 gcc_assert (!INSN_DELETED_P (tmp)); 3392 gcc_assert (!NOTE_P (tmp) 3393 || NOTE_LINE_NUMBER (tmp) != NOTE_INSN_DELETED); 3394 break; 3395 3396 default: 3397 break; 3398 } 3399 3400#ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY 3401 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode, 3402 align, desc->labelno, done); 3403#endif 3404 3405 assemble_align (align); 3406 3407 /* Output the label. */ 3408 targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno); 3409 3410 /* Output the data. */ 3411 output_constant_pool_2 (desc->mode, x, align); 3412 3413 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS 3414 sections have proper size. */ 3415 if (align > GET_MODE_BITSIZE (desc->mode) 3416 && in_section 3417 && (in_section->common.flags & SECTION_MERGE)) 3418 assemble_align (align); 3419 3420#ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY 3421 done: 3422#endif 3423 return; 3424} 3425 3426/* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers 3427 to as used. Emit referenced deferred strings. This function can 3428 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */ 3429 3430static int 3431mark_constant (rtx *current_rtx, void *data ATTRIBUTE_UNUSED) 3432{ 3433 rtx x = *current_rtx; 3434 3435 if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF) 3436 return 0; 3437 3438 if (CONSTANT_POOL_ADDRESS_P (x)) 3439 { 3440 struct constant_descriptor_rtx *desc = SYMBOL_REF_CONSTANT (x); 3441 if (desc->mark == 0) 3442 { 3443 desc->mark = 1; 3444 for_each_rtx (&desc->constant, mark_constant, NULL); 3445 } 3446 } 3447 else if (TREE_CONSTANT_POOL_ADDRESS_P (x)) 3448 { 3449 tree exp = SYMBOL_REF_DECL (x); 3450 if (!TREE_ASM_WRITTEN (exp)) 3451 { 3452 n_deferred_constants--; 3453 output_constant_def_contents (x); 3454 } 3455 } 3456 3457 return -1; 3458} 3459 3460/* Look through appropriate parts of INSN, marking all entries in the 3461 constant pool which are actually being used. Entries that are only 3462 referenced by other constants are also marked as used. Emit 3463 deferred strings that are used. */ 3464 3465static void 3466mark_constants (rtx insn) 3467{ 3468 if (!INSN_P (insn)) 3469 return; 3470 3471 /* Insns may appear inside a SEQUENCE. Only check the patterns of 3472 insns, not any notes that may be attached. We don't want to mark 3473 a constant just because it happens to appear in a REG_EQUIV note. */ 3474 if (GET_CODE (PATTERN (insn)) == SEQUENCE) 3475 { 3476 rtx seq = PATTERN (insn); 3477 int i, n = XVECLEN (seq, 0); 3478 for (i = 0; i < n; ++i) 3479 { 3480 rtx subinsn = XVECEXP (seq, 0, i); 3481 if (INSN_P (subinsn)) 3482 for_each_rtx (&PATTERN (subinsn), mark_constant, NULL); 3483 } 3484 } 3485 else 3486 for_each_rtx (&PATTERN (insn), mark_constant, NULL); 3487} 3488 3489/* Look through the instructions for this function, and mark all the 3490 entries in POOL which are actually being used. Emit deferred constants 3491 which have indeed been used. */ 3492 3493static void 3494mark_constant_pool (void) 3495{ 3496 rtx insn, link; 3497 3498 if (!current_function_uses_const_pool && n_deferred_constants == 0) 3499 return; 3500 3501 for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) 3502 mark_constants (insn); 3503 3504 for (link = current_function_epilogue_delay_list; 3505 link; 3506 link = XEXP (link, 1)) 3507 mark_constants (XEXP (link, 0)); 3508} 3509 3510/* Write all the constants in POOL. */ 3511 3512static void 3513output_constant_pool_contents (struct rtx_constant_pool *pool) 3514{ 3515 struct constant_descriptor_rtx *desc; 3516 3517 for (desc = pool->first; desc ; desc = desc->next) 3518 if (desc->mark) 3519 { 3520 /* If the constant is part of an object_block, make sure that 3521 the constant has been positioned within its block, but do not 3522 write out its definition yet. output_object_blocks will do 3523 that later. */ 3524 if (SYMBOL_REF_HAS_BLOCK_INFO_P (desc->sym) 3525 && SYMBOL_REF_BLOCK (desc->sym)) 3526 place_block_symbol (desc->sym); 3527 else 3528 { 3529 switch_to_section (targetm.asm_out.select_rtx_section 3530 (desc->mode, desc->constant, desc->align)); 3531 output_constant_pool_1 (desc, desc->align); 3532 } 3533 } 3534} 3535 3536/* Mark all constants that are used in the current function, then write 3537 out the function's private constant pool. */ 3538 3539static void 3540output_constant_pool (const char *fnname ATTRIBUTE_UNUSED, 3541 tree fndecl ATTRIBUTE_UNUSED) 3542{ 3543 struct rtx_constant_pool *pool = cfun->varasm->pool; 3544 3545 /* It is possible for gcc to call force_const_mem and then to later 3546 discard the instructions which refer to the constant. In such a 3547 case we do not need to output the constant. */ 3548 mark_constant_pool (); 3549 3550#ifdef ASM_OUTPUT_POOL_PROLOGUE 3551 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset); 3552#endif 3553 3554 output_constant_pool_contents (pool); 3555 3556#ifdef ASM_OUTPUT_POOL_EPILOGUE 3557 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset); 3558#endif 3559} 3560 3561/* Write the contents of the shared constant pool. */ 3562 3563void 3564output_shared_constant_pool (void) 3565{ 3566 output_constant_pool_contents (shared_constant_pool); 3567} 3568 3569/* Determine what kind of relocations EXP may need. */ 3570 3571int 3572compute_reloc_for_constant (tree exp) 3573{ 3574 int reloc = 0, reloc2; 3575 tree tem; 3576 3577 /* Give the front-end a chance to convert VALUE to something that 3578 looks more like a constant to the back-end. */ 3579 exp = lang_hooks.expand_constant (exp); 3580 3581 switch (TREE_CODE (exp)) 3582 { 3583 case ADDR_EXPR: 3584 case FDESC_EXPR: 3585 /* Go inside any operations that get_inner_reference can handle and see 3586 if what's inside is a constant: no need to do anything here for 3587 addresses of variables or functions. */ 3588 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem); 3589 tem = TREE_OPERAND (tem, 0)) 3590 ; 3591 3592 if (TREE_PUBLIC (tem)) 3593 reloc |= 2; 3594 else 3595 reloc |= 1; 3596 break; 3597 3598 case PLUS_EXPR: 3599 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0)); 3600 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1)); 3601 break; 3602 3603 case MINUS_EXPR: 3604 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0)); 3605 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1)); 3606 /* The difference of two local labels is computable at link time. */ 3607 if (reloc == 1 && reloc2 == 1) 3608 reloc = 0; 3609 else 3610 reloc |= reloc2; 3611 break; 3612 3613 case NOP_EXPR: 3614 case CONVERT_EXPR: 3615 case NON_LVALUE_EXPR: 3616 case VIEW_CONVERT_EXPR: 3617 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0)); 3618 break; 3619 3620 case CONSTRUCTOR: 3621 { 3622 unsigned HOST_WIDE_INT idx; 3623 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem) 3624 if (tem != 0) 3625 reloc |= compute_reloc_for_constant (tem); 3626 } 3627 break; 3628 3629 default: 3630 break; 3631 } 3632 return reloc; 3633} 3634 3635/* Find all the constants whose addresses are referenced inside of EXP, 3636 and make sure assembler code with a label has been output for each one. 3637 Indicate whether an ADDR_EXPR has been encountered. */ 3638 3639static void 3640output_addressed_constants (tree exp) 3641{ 3642 tree tem; 3643 3644 /* Give the front-end a chance to convert VALUE to something that 3645 looks more like a constant to the back-end. */ 3646 exp = lang_hooks.expand_constant (exp); 3647 3648 switch (TREE_CODE (exp)) 3649 { 3650 case ADDR_EXPR: 3651 case FDESC_EXPR: 3652 /* Go inside any operations that get_inner_reference can handle and see 3653 if what's inside is a constant: no need to do anything here for 3654 addresses of variables or functions. */ 3655 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem); 3656 tem = TREE_OPERAND (tem, 0)) 3657 ; 3658 3659 /* If we have an initialized CONST_DECL, retrieve the initializer. */ 3660 if (TREE_CODE (tem) == CONST_DECL && DECL_INITIAL (tem)) 3661 tem = DECL_INITIAL (tem); 3662 3663 if (CONSTANT_CLASS_P (tem) || TREE_CODE (tem) == CONSTRUCTOR) 3664 output_constant_def (tem, 0); 3665 break; 3666 3667 case PLUS_EXPR: 3668 case MINUS_EXPR: 3669 output_addressed_constants (TREE_OPERAND (exp, 1)); 3670 /* Fall through. */ 3671 3672 case NOP_EXPR: 3673 case CONVERT_EXPR: 3674 case NON_LVALUE_EXPR: 3675 case VIEW_CONVERT_EXPR: 3676 output_addressed_constants (TREE_OPERAND (exp, 0)); 3677 break; 3678 3679 case CONSTRUCTOR: 3680 { 3681 unsigned HOST_WIDE_INT idx; 3682 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem) 3683 if (tem != 0) 3684 output_addressed_constants (tem); 3685 } 3686 break; 3687 3688 default: 3689 break; 3690 } 3691} 3692 3693/* Whether a constructor CTOR is a valid static constant initializer if all 3694 its elements are. This used to be internal to initializer_constant_valid_p 3695 and has been exposed to let other functions like categorize_ctor_elements 3696 evaluate the property while walking a constructor for other purposes. */ 3697 3698bool 3699constructor_static_from_elts_p (tree ctor) 3700{ 3701 return (TREE_CONSTANT (ctor) 3702 && (TREE_CODE (TREE_TYPE (ctor)) == UNION_TYPE 3703 || TREE_CODE (TREE_TYPE (ctor)) == RECORD_TYPE) 3704 && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (ctor))); 3705} 3706 3707/* Return nonzero if VALUE is a valid constant-valued expression 3708 for use in initializing a static variable; one that can be an 3709 element of a "constant" initializer. 3710 3711 Return null_pointer_node if the value is absolute; 3712 if it is relocatable, return the variable that determines the relocation. 3713 We assume that VALUE has been folded as much as possible; 3714 therefore, we do not need to check for such things as 3715 arithmetic-combinations of integers. */ 3716 3717tree 3718initializer_constant_valid_p (tree value, tree endtype) 3719{ 3720 /* Give the front-end a chance to convert VALUE to something that 3721 looks more like a constant to the back-end. */ 3722 value = lang_hooks.expand_constant (value); 3723 3724 switch (TREE_CODE (value)) 3725 { 3726 case CONSTRUCTOR: 3727 if (constructor_static_from_elts_p (value)) 3728 { 3729 unsigned HOST_WIDE_INT idx; 3730 tree elt; 3731 bool absolute = true; 3732 3733 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt) 3734 { 3735 tree reloc; 3736 reloc = initializer_constant_valid_p (elt, TREE_TYPE (elt)); 3737 if (!reloc) 3738 return NULL_TREE; 3739 if (reloc != null_pointer_node) 3740 absolute = false; 3741 } 3742 /* For a non-absolute relocation, there is no single 3743 variable that can be "the variable that determines the 3744 relocation." */ 3745 return absolute ? null_pointer_node : error_mark_node; 3746 } 3747 3748 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE; 3749 3750 case INTEGER_CST: 3751 case VECTOR_CST: 3752 case REAL_CST: 3753 case STRING_CST: 3754 case COMPLEX_CST: 3755 return null_pointer_node; 3756 3757 case ADDR_EXPR: 3758 case FDESC_EXPR: 3759 value = staticp (TREE_OPERAND (value, 0)); 3760 if (value) 3761 { 3762 /* "&(*a).f" is like unto pointer arithmetic. If "a" turns out to 3763 be a constant, this is old-skool offsetof-like nonsense. */ 3764 if (TREE_CODE (value) == INDIRECT_REF 3765 && TREE_CONSTANT (TREE_OPERAND (value, 0))) 3766 return null_pointer_node; 3767 /* Taking the address of a nested function involves a trampoline. */ 3768 if (TREE_CODE (value) == FUNCTION_DECL 3769 && ((decl_function_context (value) 3770 && !DECL_NO_STATIC_CHAIN (value)) 3771 || DECL_DLLIMPORT_P (value))) 3772 return NULL_TREE; 3773 /* "&{...}" requires a temporary to hold the constructed 3774 object. */ 3775 if (TREE_CODE (value) == CONSTRUCTOR) 3776 return NULL_TREE; 3777 } 3778 return value; 3779 3780 case VIEW_CONVERT_EXPR: 3781 case NON_LVALUE_EXPR: 3782 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype); 3783 3784 case CONVERT_EXPR: 3785 case NOP_EXPR: 3786 { 3787 tree src; 3788 tree src_type; 3789 tree dest_type; 3790 3791 src = TREE_OPERAND (value, 0); 3792 src_type = TREE_TYPE (src); 3793 dest_type = TREE_TYPE (value); 3794 3795 /* Allow conversions between pointer types, floating-point 3796 types, and offset types. */ 3797 if ((POINTER_TYPE_P (dest_type) && POINTER_TYPE_P (src_type)) 3798 || (FLOAT_TYPE_P (dest_type) && FLOAT_TYPE_P (src_type)) 3799 || (TREE_CODE (dest_type) == OFFSET_TYPE 3800 && TREE_CODE (src_type) == OFFSET_TYPE)) 3801 return initializer_constant_valid_p (src, endtype); 3802 3803 /* Allow length-preserving conversions between integer types. */ 3804 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type) 3805 && (TYPE_PRECISION (dest_type) == TYPE_PRECISION (src_type))) 3806 return initializer_constant_valid_p (src, endtype); 3807 3808 /* Allow conversions between other integer types only if 3809 explicit value. */ 3810 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type)) 3811 { 3812 tree inner = initializer_constant_valid_p (src, endtype); 3813 if (inner == null_pointer_node) 3814 return null_pointer_node; 3815 break; 3816 } 3817 3818 /* Allow (int) &foo provided int is as wide as a pointer. */ 3819 if (INTEGRAL_TYPE_P (dest_type) && POINTER_TYPE_P (src_type) 3820 && (TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type))) 3821 return initializer_constant_valid_p (src, endtype); 3822 3823 /* Likewise conversions from int to pointers, but also allow 3824 conversions from 0. */ 3825 if ((POINTER_TYPE_P (dest_type) 3826 || TREE_CODE (dest_type) == OFFSET_TYPE) 3827 && INTEGRAL_TYPE_P (src_type)) 3828 { 3829 if (TREE_CODE (src) == INTEGER_CST 3830 && TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type)) 3831 return null_pointer_node; 3832 if (integer_zerop (src)) 3833 return null_pointer_node; 3834 else if (TYPE_PRECISION (dest_type) <= TYPE_PRECISION (src_type)) 3835 return initializer_constant_valid_p (src, endtype); 3836 } 3837 3838 /* Allow conversions to struct or union types if the value 3839 inside is okay. */ 3840 if (TREE_CODE (dest_type) == RECORD_TYPE 3841 || TREE_CODE (dest_type) == UNION_TYPE) 3842 return initializer_constant_valid_p (src, endtype); 3843 } 3844 break; 3845 3846 case PLUS_EXPR: 3847 if (! INTEGRAL_TYPE_P (endtype) 3848 || TYPE_PRECISION (endtype) >= POINTER_SIZE) 3849 { 3850 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0), 3851 endtype); 3852 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1), 3853 endtype); 3854 /* If either term is absolute, use the other terms relocation. */ 3855 if (valid0 == null_pointer_node) 3856 return valid1; 3857 if (valid1 == null_pointer_node) 3858 return valid0; 3859 } 3860 break; 3861 3862 case MINUS_EXPR: 3863 if (! INTEGRAL_TYPE_P (endtype) 3864 || TYPE_PRECISION (endtype) >= POINTER_SIZE) 3865 { 3866 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0), 3867 endtype); 3868 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1), 3869 endtype); 3870 /* Win if second argument is absolute. */ 3871 if (valid1 == null_pointer_node) 3872 return valid0; 3873 /* Win if both arguments have the same relocation. 3874 Then the value is absolute. */ 3875 if (valid0 == valid1 && valid0 != 0) 3876 return null_pointer_node; 3877 3878 /* Since GCC guarantees that string constants are unique in the 3879 generated code, a subtraction between two copies of the same 3880 constant string is absolute. */ 3881 if (valid0 && TREE_CODE (valid0) == STRING_CST 3882 && valid1 && TREE_CODE (valid1) == STRING_CST 3883 && operand_equal_p (valid0, valid1, 1)) 3884 return null_pointer_node; 3885 } 3886 3887 /* Support narrowing differences. */ 3888 if (INTEGRAL_TYPE_P (endtype)) 3889 { 3890 tree op0, op1; 3891 3892 op0 = TREE_OPERAND (value, 0); 3893 op1 = TREE_OPERAND (value, 1); 3894 3895 /* Like STRIP_NOPS except allow the operand mode to widen. 3896 This works around a feature of fold that simplifies 3897 (int)(p1 - p2) to ((int)p1 - (int)p2) under the theory 3898 that the narrower operation is cheaper. */ 3899 3900 while (TREE_CODE (op0) == NOP_EXPR 3901 || TREE_CODE (op0) == CONVERT_EXPR 3902 || TREE_CODE (op0) == NON_LVALUE_EXPR) 3903 { 3904 tree inner = TREE_OPERAND (op0, 0); 3905 if (inner == error_mark_node 3906 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner))) 3907 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))) 3908 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner))))) 3909 break; 3910 op0 = inner; 3911 } 3912 3913 while (TREE_CODE (op1) == NOP_EXPR 3914 || TREE_CODE (op1) == CONVERT_EXPR 3915 || TREE_CODE (op1) == NON_LVALUE_EXPR) 3916 { 3917 tree inner = TREE_OPERAND (op1, 0); 3918 if (inner == error_mark_node 3919 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner))) 3920 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1))) 3921 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner))))) 3922 break; 3923 op1 = inner; 3924 } 3925 3926 op0 = initializer_constant_valid_p (op0, endtype); 3927 op1 = initializer_constant_valid_p (op1, endtype); 3928 3929 /* Both initializers must be known. */ 3930 if (op0 && op1) 3931 { 3932 if (op0 == op1) 3933 return null_pointer_node; 3934 3935 /* Support differences between labels. */ 3936 if (TREE_CODE (op0) == LABEL_DECL 3937 && TREE_CODE (op1) == LABEL_DECL) 3938 return null_pointer_node; 3939 3940 if (TREE_CODE (op0) == STRING_CST 3941 && TREE_CODE (op1) == STRING_CST 3942 && operand_equal_p (op0, op1, 1)) 3943 return null_pointer_node; 3944 } 3945 } 3946 break; 3947 3948 default: 3949 break; 3950 } 3951 3952 return 0; 3953} 3954 3955/* Output assembler code for constant EXP to FILE, with no label. 3956 This includes the pseudo-op such as ".int" or ".byte", and a newline. 3957 Assumes output_addressed_constants has been done on EXP already. 3958 3959 Generate exactly SIZE bytes of assembler data, padding at the end 3960 with zeros if necessary. SIZE must always be specified. 3961 3962 SIZE is important for structure constructors, 3963 since trailing members may have been omitted from the constructor. 3964 It is also important for initialization of arrays from string constants 3965 since the full length of the string constant might not be wanted. 3966 It is also needed for initialization of unions, where the initializer's 3967 type is just one member, and that may not be as long as the union. 3968 3969 There a case in which we would fail to output exactly SIZE bytes: 3970 for a structure constructor that wants to produce more than SIZE bytes. 3971 But such constructors will never be generated for any possible input. 3972 3973 ALIGN is the alignment of the data in bits. */ 3974 3975void 3976output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align) 3977{ 3978 enum tree_code code; 3979 unsigned HOST_WIDE_INT thissize; 3980 3981 /* Some front-ends use constants other than the standard language-independent 3982 varieties, but which may still be output directly. Give the front-end a 3983 chance to convert EXP to a language-independent representation. */ 3984 exp = lang_hooks.expand_constant (exp); 3985 3986 if (size == 0 || flag_syntax_only) 3987 return; 3988 3989 /* See if we're trying to initialize a pointer in a non-default mode 3990 to the address of some declaration somewhere. If the target says 3991 the mode is valid for pointers, assume the target has a way of 3992 resolving it. */ 3993 if (TREE_CODE (exp) == NOP_EXPR 3994 && POINTER_TYPE_P (TREE_TYPE (exp)) 3995 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp)))) 3996 { 3997 tree saved_type = TREE_TYPE (exp); 3998 3999 /* Peel off any intermediate conversions-to-pointer for valid 4000 pointer modes. */ 4001 while (TREE_CODE (exp) == NOP_EXPR 4002 && POINTER_TYPE_P (TREE_TYPE (exp)) 4003 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp)))) 4004 exp = TREE_OPERAND (exp, 0); 4005 4006 /* If what we're left with is the address of something, we can 4007 convert the address to the final type and output it that 4008 way. */ 4009 if (TREE_CODE (exp) == ADDR_EXPR) 4010 exp = build1 (ADDR_EXPR, saved_type, TREE_OPERAND (exp, 0)); 4011 /* Likewise for constant ints. */ 4012 else if (TREE_CODE (exp) == INTEGER_CST) 4013 exp = build_int_cst_wide (saved_type, TREE_INT_CST_LOW (exp), 4014 TREE_INT_CST_HIGH (exp)); 4015 4016 } 4017 4018 /* Eliminate any conversions since we'll be outputting the underlying 4019 constant. */ 4020 while (TREE_CODE (exp) == NOP_EXPR || TREE_CODE (exp) == CONVERT_EXPR 4021 || TREE_CODE (exp) == NON_LVALUE_EXPR 4022 || TREE_CODE (exp) == VIEW_CONVERT_EXPR) 4023 { 4024 HOST_WIDE_INT type_size = int_size_in_bytes (TREE_TYPE (exp)); 4025 HOST_WIDE_INT op_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (exp, 0))); 4026 4027 /* Make sure eliminating the conversion is really a no-op, except with 4028 VIEW_CONVERT_EXPRs to allow for wild Ada unchecked conversions and 4029 union types to allow for Ada unchecked unions. */ 4030 if (type_size > op_size 4031 && TREE_CODE (exp) != VIEW_CONVERT_EXPR 4032 && TREE_CODE (TREE_TYPE (exp)) != UNION_TYPE) 4033 /* Keep the conversion. */ 4034 break; 4035 else 4036 exp = TREE_OPERAND (exp, 0); 4037 } 4038 4039 code = TREE_CODE (TREE_TYPE (exp)); 4040 thissize = int_size_in_bytes (TREE_TYPE (exp)); 4041 4042 /* Give the front end another chance to expand constants. */ 4043 exp = lang_hooks.expand_constant (exp); 4044 4045 /* Allow a constructor with no elements for any data type. 4046 This means to fill the space with zeros. */ 4047 if (TREE_CODE (exp) == CONSTRUCTOR 4048 && VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (exp))) 4049 { 4050 assemble_zeros (size); 4051 return; 4052 } 4053 4054 if (TREE_CODE (exp) == FDESC_EXPR) 4055 { 4056#ifdef ASM_OUTPUT_FDESC 4057 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0); 4058 tree decl = TREE_OPERAND (exp, 0); 4059 ASM_OUTPUT_FDESC (asm_out_file, decl, part); 4060#else 4061 gcc_unreachable (); 4062#endif 4063 return; 4064 } 4065 4066 /* Now output the underlying data. If we've handling the padding, return. 4067 Otherwise, break and ensure SIZE is the size written. */ 4068 switch (code) 4069 { 4070 case BOOLEAN_TYPE: 4071 case INTEGER_TYPE: 4072 case ENUMERAL_TYPE: 4073 case POINTER_TYPE: 4074 case REFERENCE_TYPE: 4075 case OFFSET_TYPE: 4076 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode, 4077 EXPAND_INITIALIZER), 4078 MIN (size, thissize), align, 0)) 4079 error ("initializer for integer value is too complicated"); 4080 break; 4081 4082 case REAL_TYPE: 4083 if (TREE_CODE (exp) != REAL_CST) 4084 error ("initializer for floating value is not a floating constant"); 4085 4086 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align); 4087 break; 4088 4089 case COMPLEX_TYPE: 4090 output_constant (TREE_REALPART (exp), thissize / 2, align); 4091 output_constant (TREE_IMAGPART (exp), thissize / 2, 4092 min_align (align, BITS_PER_UNIT * (thissize / 2))); 4093 break; 4094 4095 case ARRAY_TYPE: 4096 case VECTOR_TYPE: 4097 switch (TREE_CODE (exp)) 4098 { 4099 case CONSTRUCTOR: 4100 output_constructor (exp, size, align); 4101 return; 4102 case STRING_CST: 4103 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp), 4104 size); 4105 assemble_string (TREE_STRING_POINTER (exp), thissize); 4106 break; 4107 4108 case VECTOR_CST: 4109 { 4110 int elt_size; 4111 tree link; 4112 unsigned int nalign; 4113 enum machine_mode inner; 4114 4115 inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp))); 4116 nalign = MIN (align, GET_MODE_ALIGNMENT (inner)); 4117 4118 elt_size = GET_MODE_SIZE (inner); 4119 4120 link = TREE_VECTOR_CST_ELTS (exp); 4121 output_constant (TREE_VALUE (link), elt_size, align); 4122 thissize = elt_size; 4123 while ((link = TREE_CHAIN (link)) != NULL) 4124 { 4125 output_constant (TREE_VALUE (link), elt_size, nalign); 4126 thissize += elt_size; 4127 } 4128 break; 4129 } 4130 default: 4131 gcc_unreachable (); 4132 } 4133 break; 4134 4135 case RECORD_TYPE: 4136 case UNION_TYPE: 4137 gcc_assert (TREE_CODE (exp) == CONSTRUCTOR); 4138 output_constructor (exp, size, align); 4139 return; 4140 4141 case ERROR_MARK: 4142 return; 4143 4144 default: 4145 gcc_unreachable (); 4146 } 4147 4148 if (size > thissize) 4149 assemble_zeros (size - thissize); 4150} 4151 4152 4153/* Subroutine of output_constructor, used for computing the size of 4154 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array 4155 type with an unspecified upper bound. */ 4156 4157static unsigned HOST_WIDE_INT 4158array_size_for_constructor (tree val) 4159{ 4160 tree max_index, i; 4161 unsigned HOST_WIDE_INT cnt; 4162 tree index, value, tmp; 4163 4164 /* This code used to attempt to handle string constants that are not 4165 arrays of single-bytes, but nothing else does, so there's no point in 4166 doing it here. */ 4167 if (TREE_CODE (val) == STRING_CST) 4168 return TREE_STRING_LENGTH (val); 4169 4170 max_index = NULL_TREE; 4171 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (val), cnt, index, value) 4172 { 4173 if (TREE_CODE (index) == RANGE_EXPR) 4174 index = TREE_OPERAND (index, 1); 4175 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index)) 4176 max_index = index; 4177 } 4178 4179 if (max_index == NULL_TREE) 4180 return 0; 4181 4182 /* Compute the total number of array elements. */ 4183 tmp = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val))); 4184 i = size_binop (MINUS_EXPR, fold_convert (sizetype, max_index), 4185 fold_convert (sizetype, tmp)); 4186 i = size_binop (PLUS_EXPR, i, build_int_cst (sizetype, 1)); 4187 4188 /* Multiply by the array element unit size to find number of bytes. */ 4189 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val)))); 4190 4191 return tree_low_cst (i, 1); 4192} 4193 4194/* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants). 4195 Generate at least SIZE bytes, padding if necessary. */ 4196 4197static void 4198output_constructor (tree exp, unsigned HOST_WIDE_INT size, 4199 unsigned int align) 4200{ 4201 tree type = TREE_TYPE (exp); 4202 tree field = 0; 4203 tree min_index = 0; 4204 /* Number of bytes output or skipped so far. 4205 In other words, current position within the constructor. */ 4206 HOST_WIDE_INT total_bytes = 0; 4207 /* Nonzero means BYTE contains part of a byte, to be output. */ 4208 int byte_buffer_in_use = 0; 4209 int byte = 0; 4210 unsigned HOST_WIDE_INT cnt; 4211 constructor_elt *ce; 4212 4213 gcc_assert (HOST_BITS_PER_WIDE_INT >= BITS_PER_UNIT); 4214 4215 if (TREE_CODE (type) == RECORD_TYPE) 4216 field = TYPE_FIELDS (type); 4217 4218 if (TREE_CODE (type) == ARRAY_TYPE 4219 && TYPE_DOMAIN (type) != 0) 4220 min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (type)); 4221 4222 /* As LINK goes through the elements of the constant, 4223 FIELD goes through the structure fields, if the constant is a structure. 4224 if the constant is a union, then we override this, 4225 by getting the field from the TREE_LIST element. 4226 But the constant could also be an array. Then FIELD is zero. 4227 4228 There is always a maximum of one element in the chain LINK for unions 4229 (even if the initializer in a source program incorrectly contains 4230 more one). */ 4231 for (cnt = 0; 4232 VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (exp), cnt, ce); 4233 cnt++, field = field ? TREE_CHAIN (field) : 0) 4234 { 4235 tree val = ce->value; 4236 tree index = 0; 4237 4238 /* The element in a union constructor specifies the proper field 4239 or index. */ 4240 if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE 4241 || TREE_CODE (type) == QUAL_UNION_TYPE) 4242 && ce->index != 0) 4243 field = ce->index; 4244 4245 else if (TREE_CODE (type) == ARRAY_TYPE) 4246 index = ce->index; 4247 4248#ifdef ASM_COMMENT_START 4249 if (field && flag_verbose_asm) 4250 fprintf (asm_out_file, "%s %s:\n", 4251 ASM_COMMENT_START, 4252 DECL_NAME (field) 4253 ? IDENTIFIER_POINTER (DECL_NAME (field)) 4254 : "<anonymous>"); 4255#endif 4256 4257 /* Eliminate the marker that makes a cast not be an lvalue. */ 4258 if (val != 0) 4259 STRIP_NOPS (val); 4260 4261 if (index && TREE_CODE (index) == RANGE_EXPR) 4262 { 4263 unsigned HOST_WIDE_INT fieldsize 4264 = int_size_in_bytes (TREE_TYPE (type)); 4265 HOST_WIDE_INT lo_index = tree_low_cst (TREE_OPERAND (index, 0), 0); 4266 HOST_WIDE_INT hi_index = tree_low_cst (TREE_OPERAND (index, 1), 0); 4267 HOST_WIDE_INT index; 4268 unsigned int align2 = min_align (align, fieldsize * BITS_PER_UNIT); 4269 4270 for (index = lo_index; index <= hi_index; index++) 4271 { 4272 /* Output the element's initial value. */ 4273 if (val == 0) 4274 assemble_zeros (fieldsize); 4275 else 4276 output_constant (val, fieldsize, align2); 4277 4278 /* Count its size. */ 4279 total_bytes += fieldsize; 4280 } 4281 } 4282 else if (field == 0 || !DECL_BIT_FIELD (field)) 4283 { 4284 /* An element that is not a bit-field. */ 4285 4286 unsigned HOST_WIDE_INT fieldsize; 4287 /* Since this structure is static, 4288 we know the positions are constant. */ 4289 HOST_WIDE_INT pos = field ? int_byte_position (field) : 0; 4290 unsigned int align2; 4291 4292 if (index != 0) 4293 pos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (val)), 1) 4294 * (tree_low_cst (index, 0) - tree_low_cst (min_index, 0))); 4295 4296 /* Output any buffered-up bit-fields preceding this element. */ 4297 if (byte_buffer_in_use) 4298 { 4299 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1); 4300 total_bytes++; 4301 byte_buffer_in_use = 0; 4302 } 4303 4304 /* Advance to offset of this element. 4305 Note no alignment needed in an array, since that is guaranteed 4306 if each element has the proper size. */ 4307 if ((field != 0 || index != 0) && pos != total_bytes) 4308 { 4309 gcc_assert (pos >= total_bytes); 4310 assemble_zeros (pos - total_bytes); 4311 total_bytes = pos; 4312 } 4313 4314 /* Find the alignment of this element. */ 4315 align2 = min_align (align, BITS_PER_UNIT * pos); 4316 4317 /* Determine size this element should occupy. */ 4318 if (field) 4319 { 4320 fieldsize = 0; 4321 4322 /* If this is an array with an unspecified upper bound, 4323 the initializer determines the size. */ 4324 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL, 4325 but we cannot do this until the deprecated support for 4326 initializing zero-length array members is removed. */ 4327 if (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE 4328 && TYPE_DOMAIN (TREE_TYPE (field)) 4329 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (field)))) 4330 { 4331 fieldsize = array_size_for_constructor (val); 4332 /* Given a non-empty initialization, this field had 4333 better be last. */ 4334 gcc_assert (!fieldsize || !TREE_CHAIN (field)); 4335 } 4336 else if (DECL_SIZE_UNIT (field)) 4337 { 4338 /* ??? This can't be right. If the decl size overflows 4339 a host integer we will silently emit no data. */ 4340 if (host_integerp (DECL_SIZE_UNIT (field), 1)) 4341 fieldsize = tree_low_cst (DECL_SIZE_UNIT (field), 1); 4342 } 4343 } 4344 else 4345 fieldsize = int_size_in_bytes (TREE_TYPE (type)); 4346 4347 /* Output the element's initial value. */ 4348 if (val == 0) 4349 assemble_zeros (fieldsize); 4350 else 4351 output_constant (val, fieldsize, align2); 4352 4353 /* Count its size. */ 4354 total_bytes += fieldsize; 4355 } 4356 else if (val != 0 && TREE_CODE (val) != INTEGER_CST) 4357 error ("invalid initial value for member %qs", 4358 IDENTIFIER_POINTER (DECL_NAME (field))); 4359 else 4360 { 4361 /* Element that is a bit-field. */ 4362 4363 HOST_WIDE_INT next_offset = int_bit_position (field); 4364 HOST_WIDE_INT end_offset 4365 = (next_offset + tree_low_cst (DECL_SIZE (field), 1)); 4366 4367 if (val == 0) 4368 val = integer_zero_node; 4369 4370 /* If this field does not start in this (or, next) byte, 4371 skip some bytes. */ 4372 if (next_offset / BITS_PER_UNIT != total_bytes) 4373 { 4374 /* Output remnant of any bit field in previous bytes. */ 4375 if (byte_buffer_in_use) 4376 { 4377 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1); 4378 total_bytes++; 4379 byte_buffer_in_use = 0; 4380 } 4381 4382 /* If still not at proper byte, advance to there. */ 4383 if (next_offset / BITS_PER_UNIT != total_bytes) 4384 { 4385 gcc_assert (next_offset / BITS_PER_UNIT >= total_bytes); 4386 assemble_zeros (next_offset / BITS_PER_UNIT - total_bytes); 4387 total_bytes = next_offset / BITS_PER_UNIT; 4388 } 4389 } 4390 4391 if (! byte_buffer_in_use) 4392 byte = 0; 4393 4394 /* We must split the element into pieces that fall within 4395 separate bytes, and combine each byte with previous or 4396 following bit-fields. */ 4397 4398 /* next_offset is the offset n fbits from the beginning of 4399 the structure to the next bit of this element to be processed. 4400 end_offset is the offset of the first bit past the end of 4401 this element. */ 4402 while (next_offset < end_offset) 4403 { 4404 int this_time; 4405 int shift; 4406 HOST_WIDE_INT value; 4407 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT; 4408 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT; 4409 4410 /* Advance from byte to byte 4411 within this element when necessary. */ 4412 while (next_byte != total_bytes) 4413 { 4414 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1); 4415 total_bytes++; 4416 byte = 0; 4417 } 4418 4419 /* Number of bits we can process at once 4420 (all part of the same byte). */ 4421 this_time = MIN (end_offset - next_offset, 4422 BITS_PER_UNIT - next_bit); 4423 if (BYTES_BIG_ENDIAN) 4424 { 4425 /* On big-endian machine, take the most significant bits 4426 first (of the bits that are significant) 4427 and put them into bytes from the most significant end. */ 4428 shift = end_offset - next_offset - this_time; 4429 4430 /* Don't try to take a bunch of bits that cross 4431 the word boundary in the INTEGER_CST. We can 4432 only select bits from the LOW or HIGH part 4433 not from both. */ 4434 if (shift < HOST_BITS_PER_WIDE_INT 4435 && shift + this_time > HOST_BITS_PER_WIDE_INT) 4436 { 4437 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT; 4438 shift = HOST_BITS_PER_WIDE_INT; 4439 } 4440 4441 /* Now get the bits from the appropriate constant word. */ 4442 if (shift < HOST_BITS_PER_WIDE_INT) 4443 value = TREE_INT_CST_LOW (val); 4444 else 4445 { 4446 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT); 4447 value = TREE_INT_CST_HIGH (val); 4448 shift -= HOST_BITS_PER_WIDE_INT; 4449 } 4450 4451 /* Get the result. This works only when: 4452 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */ 4453 byte |= (((value >> shift) 4454 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1)) 4455 << (BITS_PER_UNIT - this_time - next_bit)); 4456 } 4457 else 4458 { 4459 /* On little-endian machines, 4460 take first the least significant bits of the value 4461 and pack them starting at the least significant 4462 bits of the bytes. */ 4463 shift = next_offset - int_bit_position (field); 4464 4465 /* Don't try to take a bunch of bits that cross 4466 the word boundary in the INTEGER_CST. We can 4467 only select bits from the LOW or HIGH part 4468 not from both. */ 4469 if (shift < HOST_BITS_PER_WIDE_INT 4470 && shift + this_time > HOST_BITS_PER_WIDE_INT) 4471 this_time = (HOST_BITS_PER_WIDE_INT - shift); 4472 4473 /* Now get the bits from the appropriate constant word. */ 4474 if (shift < HOST_BITS_PER_WIDE_INT) 4475 value = TREE_INT_CST_LOW (val); 4476 else 4477 { 4478 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT); 4479 value = TREE_INT_CST_HIGH (val); 4480 shift -= HOST_BITS_PER_WIDE_INT; 4481 } 4482 4483 /* Get the result. This works only when: 4484 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */ 4485 byte |= (((value >> shift) 4486 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1)) 4487 << next_bit); 4488 } 4489 4490 next_offset += this_time; 4491 byte_buffer_in_use = 1; 4492 } 4493 } 4494 } 4495 4496 if (byte_buffer_in_use) 4497 { 4498 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1); 4499 total_bytes++; 4500 } 4501 4502 if ((unsigned HOST_WIDE_INT)total_bytes < size) 4503 assemble_zeros (size - total_bytes); 4504} 4505 4506/* This TREE_LIST contains any weak symbol declarations waiting 4507 to be emitted. */ 4508static GTY(()) tree weak_decls; 4509 4510/* Mark DECL as weak. */ 4511 4512static void 4513mark_weak (tree decl) 4514{ 4515 DECL_WEAK (decl) = 1; 4516 4517 if (DECL_RTL_SET_P (decl) 4518 && MEM_P (DECL_RTL (decl)) 4519 && XEXP (DECL_RTL (decl), 0) 4520 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF) 4521 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1; 4522} 4523 4524/* Merge weak status between NEWDECL and OLDDECL. */ 4525 4526void 4527merge_weak (tree newdecl, tree olddecl) 4528{ 4529 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl)) 4530 { 4531 if (DECL_WEAK (newdecl) && SUPPORTS_WEAK) 4532 { 4533 tree *pwd; 4534 /* We put the NEWDECL on the weak_decls list at some point 4535 and OLDDECL as well. Keep just OLDDECL on the list. */ 4536 for (pwd = &weak_decls; *pwd; pwd = &TREE_CHAIN (*pwd)) 4537 if (TREE_VALUE (*pwd) == newdecl) 4538 { 4539 *pwd = TREE_CHAIN (*pwd); 4540 break; 4541 } 4542 } 4543 return; 4544 } 4545 4546 if (DECL_WEAK (newdecl)) 4547 { 4548 tree wd; 4549 4550 /* NEWDECL is weak, but OLDDECL is not. */ 4551 4552 /* If we already output the OLDDECL, we're in trouble; we can't 4553 go back and make it weak. This error cannot caught in 4554 declare_weak because the NEWDECL and OLDDECL was not yet 4555 been merged; therefore, TREE_ASM_WRITTEN was not set. */ 4556 if (TREE_ASM_WRITTEN (olddecl)) 4557 error ("weak declaration of %q+D must precede definition", 4558 newdecl); 4559 4560 /* If we've already generated rtl referencing OLDDECL, we may 4561 have done so in a way that will not function properly with 4562 a weak symbol. */ 4563 else if (TREE_USED (olddecl) 4564 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl))) 4565 warning (0, "weak declaration of %q+D after first use results " 4566 "in unspecified behavior", newdecl); 4567 4568 if (SUPPORTS_WEAK) 4569 { 4570 /* We put the NEWDECL on the weak_decls list at some point. 4571 Replace it with the OLDDECL. */ 4572 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd)) 4573 if (TREE_VALUE (wd) == newdecl) 4574 { 4575 TREE_VALUE (wd) = olddecl; 4576 break; 4577 } 4578 /* We may not find the entry on the list. If NEWDECL is a 4579 weak alias, then we will have already called 4580 globalize_decl to remove the entry; in that case, we do 4581 not need to do anything. */ 4582 } 4583 4584 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */ 4585 mark_weak (olddecl); 4586 } 4587 else 4588 /* OLDDECL was weak, but NEWDECL was not explicitly marked as 4589 weak. Just update NEWDECL to indicate that it's weak too. */ 4590 mark_weak (newdecl); 4591} 4592 4593/* Declare DECL to be a weak symbol. */ 4594 4595void 4596declare_weak (tree decl) 4597{ 4598 if (! TREE_PUBLIC (decl)) 4599 error ("weak declaration of %q+D must be public", decl); 4600 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl)) 4601 error ("weak declaration of %q+D must precede definition", decl); 4602 else if (SUPPORTS_WEAK) 4603 { 4604 if (! DECL_WEAK (decl)) 4605 weak_decls = tree_cons (NULL, decl, weak_decls); 4606 } 4607 else 4608 warning (0, "weak declaration of %q+D not supported", decl); 4609 4610 mark_weak (decl); 4611} 4612 4613static void 4614weak_finish_1 (tree decl) 4615{ 4616#if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL) 4617 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)); 4618#endif 4619 4620 if (! TREE_USED (decl)) 4621 return; 4622 4623#ifdef ASM_WEAKEN_DECL 4624 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL); 4625#else 4626#ifdef ASM_WEAKEN_LABEL 4627 ASM_WEAKEN_LABEL (asm_out_file, name); 4628#else 4629#ifdef ASM_OUTPUT_WEAK_ALIAS 4630 { 4631 static bool warn_once = 0; 4632 if (! warn_once) 4633 { 4634 warning (0, "only weak aliases are supported in this configuration"); 4635 warn_once = 1; 4636 } 4637 return; 4638 } 4639#endif 4640#endif 4641#endif 4642} 4643 4644/* This TREE_LIST contains weakref targets. */ 4645 4646static GTY(()) tree weakref_targets; 4647 4648/* Forward declaration. */ 4649static tree find_decl_and_mark_needed (tree decl, tree target); 4650 4651/* Emit any pending weak declarations. */ 4652 4653void 4654weak_finish (void) 4655{ 4656 tree t; 4657 4658 for (t = weakref_targets; t; t = TREE_CHAIN (t)) 4659 { 4660 tree alias_decl = TREE_PURPOSE (t); 4661 tree target = ultimate_transparent_alias_target (&TREE_VALUE (t)); 4662 4663 if (! TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (alias_decl))) 4664 /* Remove alias_decl from the weak list, but leave entries for 4665 the target alone. */ 4666 target = NULL_TREE; 4667#ifndef ASM_OUTPUT_WEAKREF 4668 else if (! TREE_SYMBOL_REFERENCED (target)) 4669 { 4670 /* Use ASM_WEAKEN_LABEL only if ASM_WEAKEN_DECL is not 4671 defined, otherwise we and weak_finish_1 would use a 4672 different macros. */ 4673# if defined ASM_WEAKEN_LABEL && ! defined ASM_WEAKEN_DECL 4674 ASM_WEAKEN_LABEL (asm_out_file, IDENTIFIER_POINTER (target)); 4675# else 4676 tree decl = find_decl_and_mark_needed (alias_decl, target); 4677 4678 if (! decl) 4679 { 4680 decl = build_decl (TREE_CODE (alias_decl), target, 4681 TREE_TYPE (alias_decl)); 4682 4683 DECL_EXTERNAL (decl) = 1; 4684 TREE_PUBLIC (decl) = 1; 4685 DECL_ARTIFICIAL (decl) = 1; 4686 TREE_NOTHROW (decl) = TREE_NOTHROW (alias_decl); 4687 TREE_USED (decl) = 1; 4688 } 4689 4690 weak_finish_1 (decl); 4691# endif 4692 } 4693#endif 4694 4695 { 4696 tree *p; 4697 tree t2; 4698 4699 /* Remove the alias and the target from the pending weak list 4700 so that we do not emit any .weak directives for the former, 4701 nor multiple .weak directives for the latter. */ 4702 for (p = &weak_decls; (t2 = *p) ; ) 4703 { 4704 if (TREE_VALUE (t2) == alias_decl 4705 || target == DECL_ASSEMBLER_NAME (TREE_VALUE (t2))) 4706 *p = TREE_CHAIN (t2); 4707 else 4708 p = &TREE_CHAIN (t2); 4709 } 4710 4711 /* Remove other weakrefs to the same target, to speed things up. */ 4712 for (p = &TREE_CHAIN (t); (t2 = *p) ; ) 4713 { 4714 if (target == ultimate_transparent_alias_target (&TREE_VALUE (t2))) 4715 *p = TREE_CHAIN (t2); 4716 else 4717 p = &TREE_CHAIN (t2); 4718 } 4719 } 4720 } 4721 4722 for (t = weak_decls; t; t = TREE_CHAIN (t)) 4723 { 4724 tree decl = TREE_VALUE (t); 4725 4726 weak_finish_1 (decl); 4727 } 4728} 4729 4730/* Emit the assembly bits to indicate that DECL is globally visible. */ 4731 4732static void 4733globalize_decl (tree decl) 4734{ 4735 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0); 4736 4737#if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL) 4738 if (DECL_WEAK (decl)) 4739 { 4740 tree *p, t; 4741 4742#ifdef ASM_WEAKEN_DECL 4743 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0); 4744#else 4745 ASM_WEAKEN_LABEL (asm_out_file, name); 4746#endif 4747 4748 /* Remove this function from the pending weak list so that 4749 we do not emit multiple .weak directives for it. */ 4750 for (p = &weak_decls; (t = *p) ; ) 4751 { 4752 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t))) 4753 *p = TREE_CHAIN (t); 4754 else 4755 p = &TREE_CHAIN (t); 4756 } 4757 4758 /* Remove weakrefs to the same target from the pending weakref 4759 list, for the same reason. */ 4760 for (p = &weakref_targets; (t = *p) ; ) 4761 { 4762 if (DECL_ASSEMBLER_NAME (decl) 4763 == ultimate_transparent_alias_target (&TREE_VALUE (t))) 4764 *p = TREE_CHAIN (t); 4765 else 4766 p = &TREE_CHAIN (t); 4767 } 4768 4769 return; 4770 } 4771#elif defined(ASM_MAKE_LABEL_LINKONCE) 4772 if (DECL_ONE_ONLY (decl)) 4773 ASM_MAKE_LABEL_LINKONCE (asm_out_file, name); 4774#endif 4775 4776 targetm.asm_out.globalize_label (asm_out_file, name); 4777} 4778 4779/* We have to be able to tell cgraph about the needed-ness of the target 4780 of an alias. This requires that the decl have been defined. Aliases 4781 that precede their definition have to be queued for later processing. */ 4782 4783typedef struct alias_pair GTY(()) 4784{ 4785 tree decl; 4786 tree target; 4787} alias_pair; 4788 4789/* Define gc'd vector type. */ 4790DEF_VEC_O(alias_pair); 4791DEF_VEC_ALLOC_O(alias_pair,gc); 4792 4793static GTY(()) VEC(alias_pair,gc) *alias_pairs; 4794 4795/* Given an assembly name, find the decl it is associated with. At the 4796 same time, mark it needed for cgraph. */ 4797 4798static tree 4799find_decl_and_mark_needed (tree decl, tree target) 4800{ 4801 struct cgraph_node *fnode = NULL; 4802 struct cgraph_varpool_node *vnode = NULL; 4803 4804 if (TREE_CODE (decl) == FUNCTION_DECL) 4805 { 4806 fnode = cgraph_node_for_asm (target); 4807 if (fnode == NULL) 4808 vnode = cgraph_varpool_node_for_asm (target); 4809 } 4810 else 4811 { 4812 vnode = cgraph_varpool_node_for_asm (target); 4813 if (vnode == NULL) 4814 fnode = cgraph_node_for_asm (target); 4815 } 4816 4817 if (fnode) 4818 { 4819 /* We can't mark function nodes as used after cgraph global info 4820 is finished. This wouldn't generally be necessary, but C++ 4821 virtual table thunks are introduced late in the game and 4822 might seem like they need marking, although in fact they 4823 don't. */ 4824 if (! cgraph_global_info_ready) 4825 cgraph_mark_needed_node (fnode); 4826 return fnode->decl; 4827 } 4828 else if (vnode) 4829 { 4830 cgraph_varpool_mark_needed_node (vnode); 4831 return vnode->decl; 4832 } 4833 else 4834 return NULL_TREE; 4835} 4836 4837/* Output the assembler code for a define (equate) using ASM_OUTPUT_DEF 4838 or ASM_OUTPUT_DEF_FROM_DECLS. The function defines the symbol whose 4839 tree node is DECL to have the value of the tree node TARGET. */ 4840 4841static void 4842do_assemble_alias (tree decl, tree target) 4843{ 4844 if (TREE_ASM_WRITTEN (decl)) 4845 return; 4846 4847 TREE_ASM_WRITTEN (decl) = 1; 4848 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1; 4849 4850 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl))) 4851 { 4852 ultimate_transparent_alias_target (&target); 4853 4854 if (!TREE_SYMBOL_REFERENCED (target)) 4855 weakref_targets = tree_cons (decl, target, weakref_targets); 4856 4857#ifdef ASM_OUTPUT_WEAKREF 4858 ASM_OUTPUT_WEAKREF (asm_out_file, decl, 4859 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)), 4860 IDENTIFIER_POINTER (target)); 4861#else 4862 if (!SUPPORTS_WEAK) 4863 { 4864 error ("%Jweakref is not supported in this configuration", decl); 4865 return; 4866 } 4867#endif 4868 return; 4869 } 4870 4871#ifdef ASM_OUTPUT_DEF 4872 /* Make name accessible from other files, if appropriate. */ 4873 4874 if (TREE_PUBLIC (decl)) 4875 { 4876 globalize_decl (decl); 4877 maybe_assemble_visibility (decl); 4878 } 4879 4880# ifdef ASM_OUTPUT_DEF_FROM_DECLS 4881 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target); 4882# else 4883 ASM_OUTPUT_DEF (asm_out_file, 4884 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)), 4885 IDENTIFIER_POINTER (target)); 4886# endif 4887#elif defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL) 4888 { 4889 const char *name; 4890 tree *p, t; 4891 4892 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)); 4893# ifdef ASM_WEAKEN_DECL 4894 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target)); 4895# else 4896 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target)); 4897# endif 4898 /* Remove this function from the pending weak list so that 4899 we do not emit multiple .weak directives for it. */ 4900 for (p = &weak_decls; (t = *p) ; ) 4901 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t))) 4902 *p = TREE_CHAIN (t); 4903 else 4904 p = &TREE_CHAIN (t); 4905 4906 /* Remove weakrefs to the same target from the pending weakref 4907 list, for the same reason. */ 4908 for (p = &weakref_targets; (t = *p) ; ) 4909 { 4910 if (DECL_ASSEMBLER_NAME (decl) 4911 == ultimate_transparent_alias_target (&TREE_VALUE (t))) 4912 *p = TREE_CHAIN (t); 4913 else 4914 p = &TREE_CHAIN (t); 4915 } 4916 } 4917#endif 4918} 4919 4920/* First pass of completing pending aliases. Make sure that cgraph knows 4921 which symbols will be required. */ 4922 4923void 4924finish_aliases_1 (void) 4925{ 4926 unsigned i; 4927 alias_pair *p; 4928 4929 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++) 4930 { 4931 tree target_decl; 4932 4933 target_decl = find_decl_and_mark_needed (p->decl, p->target); 4934 if (target_decl == NULL) 4935 { 4936 if (! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl))) 4937 error ("%q+D aliased to undefined symbol %qs", 4938 p->decl, IDENTIFIER_POINTER (p->target)); 4939 } 4940 else if (DECL_EXTERNAL (target_decl) 4941 && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl))) 4942 error ("%q+D aliased to external symbol %qs", 4943 p->decl, IDENTIFIER_POINTER (p->target)); 4944 } 4945} 4946 4947/* Second pass of completing pending aliases. Emit the actual assembly. 4948 This happens at the end of compilation and thus it is assured that the 4949 target symbol has been emitted. */ 4950 4951void 4952finish_aliases_2 (void) 4953{ 4954 unsigned i; 4955 alias_pair *p; 4956 4957 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++) 4958 do_assemble_alias (p->decl, p->target); 4959 4960 VEC_truncate (alias_pair, alias_pairs, 0); 4961} 4962 4963/* Emit an assembler directive to make the symbol for DECL an alias to 4964 the symbol for TARGET. */ 4965 4966void 4967assemble_alias (tree decl, tree target) 4968{ 4969 tree target_decl; 4970 bool is_weakref = false; 4971 4972 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl))) 4973 { 4974 tree alias = DECL_ASSEMBLER_NAME (decl); 4975 4976 is_weakref = true; 4977 4978 ultimate_transparent_alias_target (&target); 4979 4980 if (alias == target) 4981 error ("weakref %q+D ultimately targets itself", decl); 4982 else 4983 { 4984#ifndef ASM_OUTPUT_WEAKREF 4985 IDENTIFIER_TRANSPARENT_ALIAS (alias) = 1; 4986 TREE_CHAIN (alias) = target; 4987#endif 4988 } 4989 if (TREE_PUBLIC (decl)) 4990 error ("weakref %q+D must have static linkage", decl); 4991 } 4992 else 4993 { 4994#if !defined (ASM_OUTPUT_DEF) 4995# if !defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL) 4996 error ("%Jalias definitions not supported in this configuration", decl); 4997 return; 4998# else 4999 if (!DECL_WEAK (decl)) 5000 { 5001 error ("%Jonly weak aliases are supported in this configuration", decl); 5002 return; 5003 } 5004# endif 5005#endif 5006 } 5007 5008 /* We must force creation of DECL_RTL for debug info generation, even though 5009 we don't use it here. */ 5010 make_decl_rtl (decl); 5011 TREE_USED (decl) = 1; 5012 5013 /* A quirk of the initial implementation of aliases required that the user 5014 add "extern" to all of them. Which is silly, but now historical. Do 5015 note that the symbol is in fact locally defined. */ 5016 if (! is_weakref) 5017 DECL_EXTERNAL (decl) = 0; 5018 5019 /* Allow aliases to aliases. */ 5020 if (TREE_CODE (decl) == FUNCTION_DECL) 5021 cgraph_node (decl)->alias = true; 5022 else 5023 cgraph_varpool_node (decl)->alias = true; 5024 5025 /* If the target has already been emitted, we don't have to queue the 5026 alias. This saves a tad o memory. */ 5027 target_decl = find_decl_and_mark_needed (decl, target); 5028 if (target_decl && TREE_ASM_WRITTEN (target_decl)) 5029 do_assemble_alias (decl, target); 5030 else 5031 { 5032 alias_pair *p = VEC_safe_push (alias_pair, gc, alias_pairs, NULL); 5033 p->decl = decl; 5034 p->target = target; 5035 } 5036} 5037 5038/* Emit an assembler directive to set symbol for DECL visibility to 5039 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */ 5040 5041void 5042default_assemble_visibility (tree decl, int vis) 5043{ 5044 static const char * const visibility_types[] = { 5045 NULL, "protected", "hidden", "internal" 5046 }; 5047 5048 const char *name, *type; 5049 5050 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)); 5051 type = visibility_types[vis]; 5052 5053#ifdef HAVE_GAS_HIDDEN 5054 fprintf (asm_out_file, "\t.%s\t", type); 5055 assemble_name (asm_out_file, name); 5056 fprintf (asm_out_file, "\n"); 5057#else 5058 warning (OPT_Wattributes, "visibility attribute not supported " 5059 "in this configuration; ignored"); 5060#endif 5061} 5062 5063/* A helper function to call assemble_visibility when needed for a decl. */ 5064 5065int 5066maybe_assemble_visibility (tree decl) 5067{ 5068 enum symbol_visibility vis = DECL_VISIBILITY (decl); 5069 5070 if (vis != VISIBILITY_DEFAULT) 5071 { 5072 targetm.asm_out.visibility (decl, vis); 5073 return 1; 5074 } 5075 else 5076 return 0; 5077} 5078 5079/* Returns 1 if the target configuration supports defining public symbols 5080 so that one of them will be chosen at link time instead of generating a 5081 multiply-defined symbol error, whether through the use of weak symbols or 5082 a target-specific mechanism for having duplicates discarded. */ 5083 5084int 5085supports_one_only (void) 5086{ 5087 if (SUPPORTS_ONE_ONLY) 5088 return 1; 5089 return SUPPORTS_WEAK; 5090} 5091 5092/* Set up DECL as a public symbol that can be defined in multiple 5093 translation units without generating a linker error. */ 5094 5095void 5096make_decl_one_only (tree decl) 5097{ 5098 gcc_assert (TREE_CODE (decl) == VAR_DECL 5099 || TREE_CODE (decl) == FUNCTION_DECL); 5100 5101 TREE_PUBLIC (decl) = 1; 5102 5103 if (SUPPORTS_ONE_ONLY) 5104 { 5105#ifdef MAKE_DECL_ONE_ONLY 5106 MAKE_DECL_ONE_ONLY (decl); 5107#endif 5108 DECL_ONE_ONLY (decl) = 1; 5109 } 5110 else if (TREE_CODE (decl) == VAR_DECL 5111 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node)) 5112 DECL_COMMON (decl) = 1; 5113 else 5114 { 5115 gcc_assert (SUPPORTS_WEAK); 5116 DECL_WEAK (decl) = 1; 5117 } 5118} 5119 5120void 5121init_varasm_once (void) 5122{ 5123 section_htab = htab_create_ggc (31, section_entry_hash, 5124 section_entry_eq, NULL); 5125 object_block_htab = htab_create_ggc (31, object_block_entry_hash, 5126 object_block_entry_eq, NULL); 5127 const_desc_htab = htab_create_ggc (1009, const_desc_hash, 5128 const_desc_eq, NULL); 5129 5130 const_alias_set = new_alias_set (); 5131 shared_constant_pool = create_constant_pool (); 5132 5133#ifdef TEXT_SECTION_ASM_OP 5134 text_section = get_unnamed_section (SECTION_CODE, output_section_asm_op, 5135 TEXT_SECTION_ASM_OP); 5136#endif 5137 5138#ifdef DATA_SECTION_ASM_OP 5139 data_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op, 5140 DATA_SECTION_ASM_OP); 5141#endif 5142 5143#ifdef SDATA_SECTION_ASM_OP 5144 sdata_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op, 5145 SDATA_SECTION_ASM_OP); 5146#endif 5147 5148#ifdef READONLY_DATA_SECTION_ASM_OP 5149 readonly_data_section = get_unnamed_section (0, output_section_asm_op, 5150 READONLY_DATA_SECTION_ASM_OP); 5151#endif 5152 5153#ifdef CTORS_SECTION_ASM_OP 5154 ctors_section = get_unnamed_section (0, output_section_asm_op, 5155 CTORS_SECTION_ASM_OP); 5156#endif 5157 5158#ifdef DTORS_SECTION_ASM_OP 5159 dtors_section = get_unnamed_section (0, output_section_asm_op, 5160 DTORS_SECTION_ASM_OP); 5161#endif 5162 5163#ifdef BSS_SECTION_ASM_OP 5164 bss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS, 5165 output_section_asm_op, 5166 BSS_SECTION_ASM_OP); 5167#endif 5168 5169#ifdef SBSS_SECTION_ASM_OP 5170 sbss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS, 5171 output_section_asm_op, 5172 SBSS_SECTION_ASM_OP); 5173#endif 5174 5175 tls_comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS 5176 | SECTION_COMMON, emit_tls_common); 5177 lcomm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS 5178 | SECTION_COMMON, emit_local); 5179 comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS 5180 | SECTION_COMMON, emit_common); 5181 5182#if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS 5183 bss_noswitch_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS, 5184 emit_bss); 5185#endif 5186 5187 targetm.asm_out.init_sections (); 5188 5189 if (readonly_data_section == NULL) 5190 readonly_data_section = text_section; 5191} 5192 5193enum tls_model 5194decl_default_tls_model (tree decl) 5195{ 5196 enum tls_model kind; 5197 bool is_local; 5198 5199 is_local = targetm.binds_local_p (decl); 5200 if (!flag_shlib) 5201 { 5202 if (is_local) 5203 kind = TLS_MODEL_LOCAL_EXEC; 5204 else 5205 kind = TLS_MODEL_INITIAL_EXEC; 5206 } 5207 5208 /* Local dynamic is inefficient when we're not combining the 5209 parts of the address. */ 5210 else if (optimize && is_local) 5211 kind = TLS_MODEL_LOCAL_DYNAMIC; 5212 else 5213 kind = TLS_MODEL_GLOBAL_DYNAMIC; 5214 if (kind < flag_tls_default) 5215 kind = flag_tls_default; 5216 5217 return kind; 5218} 5219 5220/* Select a set of attributes for section NAME based on the properties 5221 of DECL and whether or not RELOC indicates that DECL's initializer 5222 might contain runtime relocations. 5223 5224 We make the section read-only and executable for a function decl, 5225 read-only for a const data decl, and writable for a non-const data decl. */ 5226 5227unsigned int 5228default_section_type_flags (tree decl, const char *name, int reloc) 5229{ 5230 unsigned int flags; 5231 5232 if (decl && TREE_CODE (decl) == FUNCTION_DECL) 5233 flags = SECTION_CODE; 5234 else if (decl && decl_readonly_section (decl, reloc)) 5235 flags = 0; 5236 else if (current_function_decl 5237 && cfun 5238 && cfun->unlikely_text_section_name 5239 && strcmp (name, cfun->unlikely_text_section_name) == 0) 5240 flags = SECTION_CODE; 5241 else if (!decl 5242 && (!current_function_decl || !cfun) 5243 && strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0) 5244 flags = SECTION_CODE; 5245 else 5246 flags = SECTION_WRITE; 5247 5248 if (decl && DECL_ONE_ONLY (decl)) 5249 flags |= SECTION_LINKONCE; 5250 5251 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl)) 5252 flags |= SECTION_TLS | SECTION_WRITE; 5253 5254 if (strcmp (name, ".bss") == 0 5255 || strncmp (name, ".bss.", 5) == 0 5256 || strncmp (name, ".gnu.linkonce.b.", 16) == 0 5257 || strcmp (name, ".sbss") == 0 5258 || strncmp (name, ".sbss.", 6) == 0 5259 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0) 5260 flags |= SECTION_BSS; 5261 5262 if (strcmp (name, ".tdata") == 0 5263 || strncmp (name, ".tdata.", 7) == 0 5264 || strncmp (name, ".gnu.linkonce.td.", 17) == 0) 5265 flags |= SECTION_TLS; 5266 5267 if (strcmp (name, ".tbss") == 0 5268 || strncmp (name, ".tbss.", 6) == 0 5269 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0) 5270 flags |= SECTION_TLS | SECTION_BSS; 5271 5272 /* These three sections have special ELF types. They are neither 5273 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't 5274 want to print a section type (@progbits or @nobits). If someone 5275 is silly enough to emit code or TLS variables to one of these 5276 sections, then don't handle them specially. */ 5277 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS)) 5278 && (strcmp (name, ".init_array") == 0 5279 || strcmp (name, ".fini_array") == 0 5280 || strcmp (name, ".preinit_array") == 0)) 5281 flags |= SECTION_NOTYPE; 5282 5283 return flags; 5284} 5285 5286/* Return true if the target supports some form of global BSS, 5287 either through bss_noswitch_section, or by selecting a BSS 5288 section in TARGET_ASM_SELECT_SECTION. */ 5289 5290bool 5291have_global_bss_p (void) 5292{ 5293 return bss_noswitch_section || targetm.have_switchable_bss_sections; 5294} 5295 5296/* Output assembly to switch to section NAME with attribute FLAGS. 5297 Four variants for common object file formats. */ 5298 5299void 5300default_no_named_section (const char *name ATTRIBUTE_UNUSED, 5301 unsigned int flags ATTRIBUTE_UNUSED, 5302 tree decl ATTRIBUTE_UNUSED) 5303{ 5304 /* Some object formats don't support named sections at all. The 5305 front-end should already have flagged this as an error. */ 5306 gcc_unreachable (); 5307} 5308 5309void 5310default_elf_asm_named_section (const char *name, unsigned int flags, 5311 tree decl ATTRIBUTE_UNUSED) 5312{ 5313 char flagchars[10], *f = flagchars; 5314 5315 /* If we have already declared this section, we can use an 5316 abbreviated form to switch back to it -- unless this section is 5317 part of a COMDAT groups, in which case GAS requires the full 5318 declaration every time. */ 5319 if (!(HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE)) 5320 && (flags & SECTION_DECLARED)) 5321 { 5322 fprintf (asm_out_file, "\t.section\t%s\n", name); 5323 return; 5324 } 5325 5326 if (!(flags & SECTION_DEBUG)) 5327 *f++ = 'a'; 5328 if (flags & SECTION_WRITE) 5329 *f++ = 'w'; 5330 if (flags & SECTION_CODE) 5331 *f++ = 'x'; 5332 if (flags & SECTION_SMALL) 5333 *f++ = 's'; 5334 if (flags & SECTION_MERGE) 5335 *f++ = 'M'; 5336 if (flags & SECTION_STRINGS) 5337 *f++ = 'S'; 5338 if (flags & SECTION_TLS) 5339 *f++ = 'T'; 5340 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE)) 5341 *f++ = 'G'; 5342 *f = '\0'; 5343 5344 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars); 5345 5346 if (!(flags & SECTION_NOTYPE)) 5347 { 5348 const char *type; 5349 const char *format; 5350 5351 if (flags & SECTION_BSS) 5352 type = "nobits"; 5353 else 5354 type = "progbits"; 5355 5356 format = ",@%s"; 5357#ifdef ASM_COMMENT_START 5358 /* On platforms that use "@" as the assembly comment character, 5359 use "%" instead. */ 5360 if (strcmp (ASM_COMMENT_START, "@") == 0) 5361 format = ",%%%s"; 5362#endif 5363 fprintf (asm_out_file, format, type); 5364 5365 if (flags & SECTION_ENTSIZE) 5366 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE); 5367 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE)) 5368 fprintf (asm_out_file, ",%s,comdat", 5369 lang_hooks.decls.comdat_group (decl)); 5370 } 5371 5372 putc ('\n', asm_out_file); 5373} 5374 5375void 5376default_coff_asm_named_section (const char *name, unsigned int flags, 5377 tree decl ATTRIBUTE_UNUSED) 5378{ 5379 char flagchars[8], *f = flagchars; 5380 5381 if (flags & SECTION_WRITE) 5382 *f++ = 'w'; 5383 if (flags & SECTION_CODE) 5384 *f++ = 'x'; 5385 *f = '\0'; 5386 5387 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars); 5388} 5389 5390void 5391default_pe_asm_named_section (const char *name, unsigned int flags, 5392 tree decl) 5393{ 5394 default_coff_asm_named_section (name, flags, decl); 5395 5396 if (flags & SECTION_LINKONCE) 5397 { 5398 /* Functions may have been compiled at various levels of 5399 optimization so we can't use `same_size' here. 5400 Instead, have the linker pick one. */ 5401 fprintf (asm_out_file, "\t.linkonce %s\n", 5402 (flags & SECTION_CODE ? "discard" : "same_size")); 5403 } 5404} 5405 5406/* The lame default section selector. */ 5407 5408section * 5409default_select_section (tree decl, int reloc, 5410 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED) 5411{ 5412 if (DECL_P (decl)) 5413 { 5414 if (decl_readonly_section (decl, reloc)) 5415 return readonly_data_section; 5416 } 5417 else if (TREE_CODE (decl) == CONSTRUCTOR) 5418 { 5419 if (! ((flag_pic && reloc) 5420 || !TREE_READONLY (decl) 5421 || TREE_SIDE_EFFECTS (decl) 5422 || !TREE_CONSTANT (decl))) 5423 return readonly_data_section; 5424 } 5425 else if (TREE_CODE (decl) == STRING_CST) 5426 return readonly_data_section; 5427 else if (! (flag_pic && reloc)) 5428 return readonly_data_section; 5429 5430 return data_section; 5431} 5432 5433enum section_category 5434categorize_decl_for_section (tree decl, int reloc) 5435{ 5436 enum section_category ret; 5437 5438 if (TREE_CODE (decl) == FUNCTION_DECL) 5439 return SECCAT_TEXT; 5440 else if (TREE_CODE (decl) == STRING_CST) 5441 { 5442 if (flag_mudflap) /* or !flag_merge_constants */ 5443 return SECCAT_RODATA; 5444 else 5445 return SECCAT_RODATA_MERGE_STR; 5446 } 5447 else if (TREE_CODE (decl) == VAR_DECL) 5448 { 5449 if (bss_initializer_p (decl)) 5450 ret = SECCAT_BSS; 5451 else if (! TREE_READONLY (decl) 5452 || TREE_SIDE_EFFECTS (decl) 5453 || ! TREE_CONSTANT (DECL_INITIAL (decl))) 5454 { 5455 /* Here the reloc_rw_mask is not testing whether the section should 5456 be read-only or not, but whether the dynamic link will have to 5457 do something. If so, we wish to segregate the data in order to 5458 minimize cache misses inside the dynamic linker. */ 5459 if (reloc & targetm.asm_out.reloc_rw_mask ()) 5460 ret = reloc == 1 ? SECCAT_DATA_REL_LOCAL : SECCAT_DATA_REL; 5461 else 5462 ret = SECCAT_DATA; 5463 } 5464 else if (reloc & targetm.asm_out.reloc_rw_mask ()) 5465 ret = reloc == 1 ? SECCAT_DATA_REL_RO_LOCAL : SECCAT_DATA_REL_RO; 5466 else if (reloc || flag_merge_constants < 2) 5467 /* C and C++ don't allow different variables to share the same 5468 location. -fmerge-all-constants allows even that (at the 5469 expense of not conforming). */ 5470 ret = SECCAT_RODATA; 5471 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST) 5472 ret = SECCAT_RODATA_MERGE_STR_INIT; 5473 else 5474 ret = SECCAT_RODATA_MERGE_CONST; 5475 } 5476 else if (TREE_CODE (decl) == CONSTRUCTOR) 5477 { 5478 if ((reloc & targetm.asm_out.reloc_rw_mask ()) 5479 || TREE_SIDE_EFFECTS (decl) 5480 || ! TREE_CONSTANT (decl)) 5481 ret = SECCAT_DATA; 5482 else 5483 ret = SECCAT_RODATA; 5484 } 5485 else 5486 ret = SECCAT_RODATA; 5487 5488 /* There are no read-only thread-local sections. */ 5489 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl)) 5490 { 5491 /* Note that this would be *just* SECCAT_BSS, except that there's 5492 no concept of a read-only thread-local-data section. */ 5493 if (ret == SECCAT_BSS 5494 || (flag_zero_initialized_in_bss 5495 && initializer_zerop (DECL_INITIAL (decl)))) 5496 ret = SECCAT_TBSS; 5497 else 5498 ret = SECCAT_TDATA; 5499 } 5500 5501 /* If the target uses small data sections, select it. */ 5502 else if (targetm.in_small_data_p (decl)) 5503 { 5504 if (ret == SECCAT_BSS) 5505 ret = SECCAT_SBSS; 5506 else if (targetm.have_srodata_section && ret == SECCAT_RODATA) 5507 ret = SECCAT_SRODATA; 5508 else 5509 ret = SECCAT_SDATA; 5510 } 5511 5512 return ret; 5513} 5514 5515bool 5516decl_readonly_section (tree decl, int reloc) 5517{ 5518 switch (categorize_decl_for_section (decl, reloc)) 5519 { 5520 case SECCAT_RODATA: 5521 case SECCAT_RODATA_MERGE_STR: 5522 case SECCAT_RODATA_MERGE_STR_INIT: 5523 case SECCAT_RODATA_MERGE_CONST: 5524 case SECCAT_SRODATA: 5525 return true; 5526 break; 5527 default: 5528 return false; 5529 break; 5530 } 5531} 5532 5533/* Select a section based on the above categorization. */ 5534 5535section * 5536default_elf_select_section (tree decl, int reloc, 5537 unsigned HOST_WIDE_INT align) 5538{ 5539 const char *sname; 5540 switch (categorize_decl_for_section (decl, reloc)) 5541 { 5542 case SECCAT_TEXT: 5543 /* We're not supposed to be called on FUNCTION_DECLs. */ 5544 gcc_unreachable (); 5545 case SECCAT_RODATA: 5546 return readonly_data_section; 5547 case SECCAT_RODATA_MERGE_STR: 5548 return mergeable_string_section (decl, align, 0); 5549 case SECCAT_RODATA_MERGE_STR_INIT: 5550 return mergeable_string_section (DECL_INITIAL (decl), align, 0); 5551 case SECCAT_RODATA_MERGE_CONST: 5552 return mergeable_constant_section (DECL_MODE (decl), align, 0); 5553 case SECCAT_SRODATA: 5554 sname = ".sdata2"; 5555 break; 5556 case SECCAT_DATA: 5557 return data_section; 5558 case SECCAT_DATA_REL: 5559 sname = ".data.rel"; 5560 break; 5561 case SECCAT_DATA_REL_LOCAL: 5562 sname = ".data.rel.local"; 5563 break; 5564 case SECCAT_DATA_REL_RO: 5565 sname = ".data.rel.ro"; 5566 break; 5567 case SECCAT_DATA_REL_RO_LOCAL: 5568 sname = ".data.rel.ro.local"; 5569 break; 5570 case SECCAT_SDATA: 5571 sname = ".sdata"; 5572 break; 5573 case SECCAT_TDATA: 5574 sname = ".tdata"; 5575 break; 5576 case SECCAT_BSS: 5577 if (bss_section) 5578 return bss_section; 5579 sname = ".bss"; 5580 break; 5581 case SECCAT_SBSS: 5582 sname = ".sbss"; 5583 break; 5584 case SECCAT_TBSS: 5585 sname = ".tbss"; 5586 break; 5587 default: 5588 gcc_unreachable (); 5589 } 5590 5591 if (!DECL_P (decl)) 5592 decl = NULL_TREE; 5593 return get_named_section (decl, sname, reloc); 5594} 5595 5596/* Construct a unique section name based on the decl name and the 5597 categorization performed above. */ 5598 5599void 5600default_unique_section (tree decl, int reloc) 5601{ 5602 /* We only need to use .gnu.linkonce if we don't have COMDAT groups. */ 5603 bool one_only = DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP; 5604 const char *prefix, *name; 5605 size_t nlen, plen; 5606 char *string; 5607 5608 switch (categorize_decl_for_section (decl, reloc)) 5609 { 5610 case SECCAT_TEXT: 5611 prefix = one_only ? ".gnu.linkonce.t." : ".text."; 5612 break; 5613 case SECCAT_RODATA: 5614 case SECCAT_RODATA_MERGE_STR: 5615 case SECCAT_RODATA_MERGE_STR_INIT: 5616 case SECCAT_RODATA_MERGE_CONST: 5617 prefix = one_only ? ".gnu.linkonce.r." : ".rodata."; 5618 break; 5619 case SECCAT_SRODATA: 5620 prefix = one_only ? ".gnu.linkonce.s2." : ".sdata2."; 5621 break; 5622 case SECCAT_DATA: 5623 prefix = one_only ? ".gnu.linkonce.d." : ".data."; 5624 break; 5625 case SECCAT_DATA_REL: 5626 prefix = one_only ? ".gnu.linkonce.d.rel." : ".data.rel."; 5627 break; 5628 case SECCAT_DATA_REL_LOCAL: 5629 prefix = one_only ? ".gnu.linkonce.d.rel.local." : ".data.rel.local."; 5630 break; 5631 case SECCAT_DATA_REL_RO: 5632 prefix = one_only ? ".gnu.linkonce.d.rel.ro." : ".data.rel.ro."; 5633 break; 5634 case SECCAT_DATA_REL_RO_LOCAL: 5635 prefix = one_only ? ".gnu.linkonce.d.rel.ro.local." 5636 : ".data.rel.ro.local."; 5637 break; 5638 case SECCAT_SDATA: 5639 prefix = one_only ? ".gnu.linkonce.s." : ".sdata."; 5640 break; 5641 case SECCAT_BSS: 5642 prefix = one_only ? ".gnu.linkonce.b." : ".bss."; 5643 break; 5644 case SECCAT_SBSS: 5645 prefix = one_only ? ".gnu.linkonce.sb." : ".sbss."; 5646 break; 5647 case SECCAT_TDATA: 5648 prefix = one_only ? ".gnu.linkonce.td." : ".tdata."; 5649 break; 5650 case SECCAT_TBSS: 5651 prefix = one_only ? ".gnu.linkonce.tb." : ".tbss."; 5652 break; 5653 default: 5654 gcc_unreachable (); 5655 } 5656 plen = strlen (prefix); 5657 5658 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)); 5659 name = targetm.strip_name_encoding (name); 5660 nlen = strlen (name); 5661 5662 string = alloca (nlen + plen + 1); 5663 memcpy (string, prefix, plen); 5664 memcpy (string + plen, name, nlen + 1); 5665 5666 DECL_SECTION_NAME (decl) = build_string (nlen + plen, string); 5667} 5668 5669/* Like compute_reloc_for_constant, except for an RTX. The return value 5670 is a mask for which bit 1 indicates a global relocation, and bit 0 5671 indicates a local relocation. */ 5672 5673static int 5674compute_reloc_for_rtx_1 (rtx *xp, void *data) 5675{ 5676 int *preloc = data; 5677 rtx x = *xp; 5678 5679 switch (GET_CODE (x)) 5680 { 5681 case SYMBOL_REF: 5682 *preloc |= SYMBOL_REF_LOCAL_P (x) ? 1 : 2; 5683 break; 5684 case LABEL_REF: 5685 *preloc |= 1; 5686 break; 5687 default: 5688 break; 5689 } 5690 5691 return 0; 5692} 5693 5694static int 5695compute_reloc_for_rtx (rtx x) 5696{ 5697 int reloc; 5698 5699 switch (GET_CODE (x)) 5700 { 5701 case CONST: 5702 case SYMBOL_REF: 5703 case LABEL_REF: 5704 reloc = 0; 5705 for_each_rtx (&x, compute_reloc_for_rtx_1, &reloc); 5706 return reloc; 5707 5708 default: 5709 return 0; 5710 } 5711} 5712 5713section * 5714default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED, 5715 rtx x, 5716 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED) 5717{ 5718 if (compute_reloc_for_rtx (x) & targetm.asm_out.reloc_rw_mask ()) 5719 return data_section; 5720 else 5721 return readonly_data_section; 5722} 5723 5724section * 5725default_elf_select_rtx_section (enum machine_mode mode, rtx x, 5726 unsigned HOST_WIDE_INT align) 5727{ 5728 int reloc = compute_reloc_for_rtx (x); 5729 5730 /* ??? Handle small data here somehow. */ 5731 5732 if (reloc & targetm.asm_out.reloc_rw_mask ()) 5733 { 5734 if (reloc == 1) 5735 return get_named_section (NULL, ".data.rel.ro.local", 1); 5736 else 5737 return get_named_section (NULL, ".data.rel.ro", 3); 5738 } 5739 5740 return mergeable_constant_section (mode, align, 0); 5741} 5742 5743/* Set the generally applicable flags on the SYMBOL_REF for EXP. */ 5744 5745void 5746default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED) 5747{ 5748 rtx symbol; 5749 int flags; 5750 5751 /* Careful not to prod global register variables. */ 5752 if (!MEM_P (rtl)) 5753 return; 5754 symbol = XEXP (rtl, 0); 5755 if (GET_CODE (symbol) != SYMBOL_REF) 5756 return; 5757 5758 flags = SYMBOL_REF_FLAGS (symbol) & SYMBOL_FLAG_HAS_BLOCK_INFO; 5759 if (TREE_CODE (decl) == FUNCTION_DECL) 5760 flags |= SYMBOL_FLAG_FUNCTION; 5761 if (targetm.binds_local_p (decl)) 5762 flags |= SYMBOL_FLAG_LOCAL; 5763 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl)) 5764 flags |= DECL_TLS_MODEL (decl) << SYMBOL_FLAG_TLS_SHIFT; 5765 else if (targetm.in_small_data_p (decl)) 5766 flags |= SYMBOL_FLAG_SMALL; 5767 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without 5768 being PUBLIC, the thing *must* be defined in this translation unit. 5769 Prevent this buglet from being propagated into rtl code as well. */ 5770 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl)) 5771 flags |= SYMBOL_FLAG_EXTERNAL; 5772 5773 SYMBOL_REF_FLAGS (symbol) = flags; 5774} 5775 5776/* By default, we do nothing for encode_section_info, so we need not 5777 do anything but discard the '*' marker. */ 5778 5779const char * 5780default_strip_name_encoding (const char *str) 5781{ 5782 return str + (*str == '*'); 5783} 5784 5785#ifdef ASM_OUTPUT_DEF 5786/* The default implementation of TARGET_ASM_OUTPUT_ANCHOR. Define the 5787 anchor relative to ".", the current section position. */ 5788 5789void 5790default_asm_output_anchor (rtx symbol) 5791{ 5792 char buffer[100]; 5793 5794 sprintf (buffer, ". + " HOST_WIDE_INT_PRINT_DEC, 5795 SYMBOL_REF_BLOCK_OFFSET (symbol)); 5796 ASM_OUTPUT_DEF (asm_out_file, XSTR (symbol, 0), buffer); 5797} 5798#endif 5799 5800/* The default implementation of TARGET_USE_ANCHORS_FOR_SYMBOL_P. */ 5801 5802bool 5803default_use_anchors_for_symbol_p (rtx symbol) 5804{ 5805 section *sect; 5806 tree decl; 5807 5808 /* Don't use anchors for mergeable sections. The linker might move 5809 the objects around. */ 5810 sect = SYMBOL_REF_BLOCK (symbol)->sect; 5811 if (sect->common.flags & SECTION_MERGE) 5812 return false; 5813 5814 /* Don't use anchors for small data sections. The small data register 5815 acts as an anchor for such sections. */ 5816 if (sect->common.flags & SECTION_SMALL) 5817 return false; 5818 5819 decl = SYMBOL_REF_DECL (symbol); 5820 if (decl && DECL_P (decl)) 5821 { 5822 /* Don't use section anchors for decls that might be defined by 5823 other modules. */ 5824 if (!targetm.binds_local_p (decl)) 5825 return false; 5826 5827 /* Don't use section anchors for decls that will be placed in a 5828 small data section. */ 5829 /* ??? Ideally, this check would be redundant with the SECTION_SMALL 5830 one above. The problem is that we only use SECTION_SMALL for 5831 sections that should be marked as small in the section directive. */ 5832 if (targetm.in_small_data_p (decl)) 5833 return false; 5834 } 5835 return true; 5836} 5837 5838/* Assume ELF-ish defaults, since that's pretty much the most liberal 5839 wrt cross-module name binding. */ 5840 5841bool 5842default_binds_local_p (tree exp) 5843{ 5844 return default_binds_local_p_1 (exp, flag_shlib); 5845} 5846 5847bool 5848default_binds_local_p_1 (tree exp, int shlib) 5849{ 5850 bool local_p; 5851 5852 /* A non-decl is an entry in the constant pool. */ 5853 if (!DECL_P (exp)) 5854 local_p = true; 5855 /* Weakrefs may not bind locally, even though the weakref itself is 5856 always static and therefore local. */ 5857 else if (lookup_attribute ("weakref", DECL_ATTRIBUTES (exp))) 5858 local_p = false; 5859 /* Static variables are always local. */ 5860 else if (! TREE_PUBLIC (exp)) 5861 local_p = true; 5862 /* A variable is local if the user has said explicitly that it will 5863 be. */ 5864 else if (DECL_VISIBILITY_SPECIFIED (exp) 5865 && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT) 5866 local_p = true; 5867 /* Variables defined outside this object might not be local. */ 5868 else if (DECL_EXTERNAL (exp)) 5869 local_p = false; 5870 /* If defined in this object and visibility is not default, must be 5871 local. */ 5872 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT) 5873 local_p = true; 5874 /* Default visibility weak data can be overridden by a strong symbol 5875 in another module and so are not local. */ 5876 else if (DECL_WEAK (exp)) 5877 local_p = false; 5878 /* If PIC, then assume that any global name can be overridden by 5879 symbols resolved from other modules. */ 5880 else if (shlib) 5881 local_p = false; 5882 /* Uninitialized COMMON variable may be unified with symbols 5883 resolved from other modules. */ 5884 else if (DECL_COMMON (exp) 5885 && (DECL_INITIAL (exp) == NULL 5886 || DECL_INITIAL (exp) == error_mark_node)) 5887 local_p = false; 5888 /* Otherwise we're left with initialized (or non-common) global data 5889 which is of necessity defined locally. */ 5890 else 5891 local_p = true; 5892 5893 return local_p; 5894} 5895 5896/* Determine whether or not a pointer mode is valid. Assume defaults 5897 of ptr_mode or Pmode - can be overridden. */ 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