gcc/langhooks.c

   1 /* Default language-specific hooks.
   2    Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
   3    Free Software Foundation, Inc.
   4    Contributed by Alexandre Oliva  <aoliva@redhat.com>
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GCC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "intl.h"
  26 #include "tm.h"
  27 #include "toplev.h"
  28 #include "tree.h"
  29 #include "tree-inline.h"
  30 #include "gimple.h"
  31 #include "rtl.h"
  32 #include "insn-config.h"
  33 #include "integrate.h"
  34 #include "flags.h"
  35 #include "langhooks.h"
  36 #include "target.h"
  37 #include "langhooks-def.h"
  38 #include "ggc.h"
  39 #include "diagnostic.h"
  40
  41 /* Do nothing; in many cases the default hook.  */
  42
  43 void
  44 lhd_do_nothing (void)
  45 {
  46 }
  47
  48 /* Do nothing (tree).  */
  49
  50 void
  51 lhd_do_nothing_t (tree ARG_UNUSED (t))
  52 {
  53 }
  54
  55 /* Do nothing (int).  */
  56
  57 void
  58 lhd_do_nothing_i (int ARG_UNUSED (i))
  59 {
  60 }
  61
  62 /* Do nothing (int, int, int).  Return NULL_TREE.  */
  63
  64 tree
  65 lhd_do_nothing_iii_return_null_tree (int ARG_UNUSED (i),
  66                                      int ARG_UNUSED (j),
  67                                      int ARG_UNUSED (k))
  68 {
  69   return NULL_TREE;
  70 }
  71
  72 /* Do nothing (function).  */
  73
  74 void
  75 lhd_do_nothing_f (struct function * ARG_UNUSED (f))
  76 {
  77 }
  78
  79 /* Do nothing (return NULL_TREE).  */
  80
  81 tree
  82 lhd_return_null_tree_v (void)
  83 {
  84   return NULL_TREE;
  85 }
  86
  87 /* Do nothing (return NULL_TREE).  */
  88
  89 tree
  90 lhd_return_null_tree (tree ARG_UNUSED (t))
  91 {
  92   return NULL_TREE;
  93 }
  94
  95 /* Do nothing (return NULL_TREE).  */
  96
  97 tree
  98 lhd_return_null_const_tree (const_tree ARG_UNUSED (t))
  99 {
 100   return NULL_TREE;
 101 }
 102
 103 /* The default post options hook.  */
 104
 105 bool
 106 lhd_post_options (const char ** ARG_UNUSED (pfilename))
 107 {
 108   /* Excess precision other than "fast" requires front-end
 109      support.  */
 110   flag_excess_precision_cmdline = EXCESS_PRECISION_FAST;
 111   return false;
 112 }
 113
 114 /* Called from by print-tree.c.  */
 115
 116 void
 117 lhd_print_tree_nothing (FILE * ARG_UNUSED (file),
 118                         tree ARG_UNUSED (node),
 119                         int ARG_UNUSED (indent))
 120 {
 121 }
 122
 123 /* Called from check_global_declarations.  */
 124
 125 bool
 126 lhd_warn_unused_global_decl (const_tree decl)
 127 {
 128   /* This is what used to exist in check_global_declarations.  Probably
 129      not many of these actually apply to non-C languages.  */
 130
 131   if (TREE_CODE (decl) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (decl))
 132     return false;
 133   if (TREE_CODE (decl) == VAR_DECL && TREE_READONLY (decl))
 134     return false;
 135   if (DECL_IN_SYSTEM_HEADER (decl))
 136     return false;
 137
 138   return true;
 139 }
 140
 141 /* Set the DECL_ASSEMBLER_NAME for DECL.  */
 142 void
 143 lhd_set_decl_assembler_name (tree decl)
 144 {
 145   tree id;
 146
 147   /* The language-independent code should never use the
 148      DECL_ASSEMBLER_NAME for lots of DECLs.  Only FUNCTION_DECLs and
 149      VAR_DECLs for variables with static storage duration need a real
 150      DECL_ASSEMBLER_NAME.  */
 151   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
 152               || (TREE_CODE (decl) == VAR_DECL
 153                   && (TREE_STATIC (decl)
 154                       || DECL_EXTERNAL (decl)
 155                       || TREE_PUBLIC (decl))));
 156
 157   /* By default, assume the name to use in assembly code is the same
 158      as that used in the source language.  (That's correct for C, and
 159      GCC used to set DECL_ASSEMBLER_NAME to the same value as
 160      DECL_NAME in build_decl, so this choice provides backwards
 161      compatibility with existing front-ends.  This assumption is wrapped
 162      in a target hook, to allow for target-specific modification of the
 163      identifier.
 164
 165      Can't use just the variable's own name for a variable whose scope
 166      is less than the whole compilation.  Concatenate a distinguishing
 167      number - we use the DECL_UID.  */
 168
 169   if (TREE_PUBLIC (decl) || DECL_CONTEXT (decl) == NULL_TREE)
 170     id = targetm.mangle_decl_assembler_name (decl, DECL_NAME (decl));
 171   else
 172     {
 173       const char *name = IDENTIFIER_POINTER (DECL_NAME (decl));
 174       char *label;
 175
 176       ASM_FORMAT_PRIVATE_NAME (label, name, DECL_UID (decl));
 177       id = get_identifier (label);
 178     }
 179   SET_DECL_ASSEMBLER_NAME (decl, id);
 180
 181 }
 182
 183 /* Type promotion for variable arguments.  */
 184 tree
 185 lhd_type_promotes_to (tree ARG_UNUSED (type))
 186 {
 187   gcc_unreachable ();
 188 }
 189
 190 /* Registration of machine- or os-specific builtin types.  */
 191 void
 192 lhd_register_builtin_type (tree ARG_UNUSED (type),
 193                            const char * ARG_UNUSED (name))
 194 {
 195 }
 196
 197 /* Invalid use of an incomplete type.  */
 198 void
 199 lhd_incomplete_type_error (const_tree ARG_UNUSED (value), const_tree type)
 200 {
 201   gcc_assert (TREE_CODE (type) == ERROR_MARK);
 202   return;
 203 }
 204
 205 /* Provide a default routine for alias sets that always returns -1.  This
 206    is used by languages that don't need to do anything special.  */
 207
 208 alias_set_type
 209 lhd_get_alias_set (tree ARG_UNUSED (t))
 210 {
 211   return -1;
 212 }
 213
 214 /* This is the default decl_printable_name function.  */
 215
 216 const char *
 217 lhd_decl_printable_name (tree decl, int ARG_UNUSED (verbosity))
 218 {
 219   gcc_assert (decl && DECL_NAME (decl));
 220   return IDENTIFIER_POINTER (DECL_NAME (decl));
 221 }
 222
 223 /* This is the default dwarf_name function.  */
 224
 225 const char *
 226 lhd_dwarf_name (tree t, int verbosity)
 227 {
 228   gcc_assert (DECL_P (t));
 229
 230   return lang_hooks.decl_printable_name (t, verbosity);
 231 }
 232
 233 /* This compares two types for equivalence ("compatible" in C-based languages).
 234    This routine should only return 1 if it is sure.  It should not be used
 235    in contexts where erroneously returning 0 causes problems.  */
 236
 237 int
 238 lhd_types_compatible_p (tree x, tree y)
 239 {
 240   return TYPE_MAIN_VARIANT (x) == TYPE_MAIN_VARIANT (y);
 241 }
 242
 243 /* lang_hooks.tree_dump.dump_tree:  Dump language-specific parts of tree
 244    nodes.  Returns nonzero if it does not want the usual dumping of the
 245    second argument.  */
 246
 247 bool
 248 lhd_tree_dump_dump_tree (void *di ATTRIBUTE_UNUSED, tree t ATTRIBUTE_UNUSED)
 249 {
 250   return false;
 251 }
 252
 253 /* lang_hooks.tree_dump.type_qual:  Determine type qualifiers in a
 254    language-specific way.  */
 255
 256 int
 257 lhd_tree_dump_type_quals (const_tree t)
 258 {
 259   return TYPE_QUALS (t);
 260 }
 261
 262 /* lang_hooks.expr_size: Determine the size of the value of an expression T
 263    in a language-specific way.  Returns a tree for the size in bytes.  */
 264
 265 tree
 266 lhd_expr_size (const_tree exp)
 267 {
 268   if (DECL_P (exp)
 269       && DECL_SIZE_UNIT (exp) != 0)
 270     return DECL_SIZE_UNIT (exp);
 271   else
 272     return size_in_bytes (TREE_TYPE (exp));
 273 }
 274
 275 /* lang_hooks.gimplify_expr re-writes *EXPR_P into GIMPLE form.  */
 276
 277 int
 278 lhd_gimplify_expr (tree *expr_p ATTRIBUTE_UNUSED,
 279                    gimple_seq *pre_p ATTRIBUTE_UNUSED,
 280                    gimple_seq *post_p ATTRIBUTE_UNUSED)
 281 {
 282   return GS_UNHANDLED;
 283 }
 284
 285 /* lang_hooks.tree_size: Determine the size of a tree with code C,
 286    which is a language-specific tree code in category tcc_constant or
 287    tcc_exceptional.  The default expects never to be called.  */
 288 size_t
 289 lhd_tree_size (enum tree_code c ATTRIBUTE_UNUSED)
 290 {
 291   gcc_unreachable ();
 292 }
 293
 294 /* Return true if decl, which is a function decl, may be called by a
 295    sibcall.  */
 296
 297 bool
 298 lhd_decl_ok_for_sibcall (const_tree decl ATTRIBUTE_UNUSED)
 299 {
 300   return true;
 301 }
 302
 303 /* Return the COMDAT group into which DECL should be placed.  */
 304
 305 const char *
 306 lhd_comdat_group (tree decl)
 307 {
 308   return IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
 309 }
 310
 311 /* lang_hooks.decls.final_write_globals: perform final processing on
 312    global variables.  */
 313 void
 314 write_global_declarations (void)
 315 {
 316   /* Really define vars that have had only a tentative definition.
 317      Really output inline functions that must actually be callable
 318      and have not been output so far.  */
 319
 320   tree globals = lang_hooks.decls.getdecls ();
 321   int len = list_length (globals);
 322   tree *vec = XNEWVEC (tree, len);
 323   int i;
 324   tree decl;
 325
 326   /* Process the decls in reverse order--earliest first.
 327      Put them into VEC from back to front, then take out from front.  */
 328
 329   for (i = 0, decl = globals; i < len; i++, decl = TREE_CHAIN (decl))
 330     vec[len - i - 1] = decl;
 331
 332   wrapup_global_declarations (vec, len);
 333   check_global_declarations (vec, len);
 334   emit_debug_global_declarations (vec, len);
 335
 336   /* Clean up.  */
 337   free (vec);
 338 }
 339
 340 /* Called to perform language-specific initialization of CTX.  */
 341 void
 342 lhd_initialize_diagnostics (struct diagnostic_context *ctx ATTRIBUTE_UNUSED)
 343 {
 344 }
 345
 346 /* The default function to print out name of current function that caused
 347    an error.  */
 348 void
 349 lhd_print_error_function (diagnostic_context *context, const char *file,
 350                           diagnostic_info *diagnostic)
 351 {
 352   if (diagnostic_last_function_changed (context, diagnostic))
 353     {
 354       const char *old_prefix = context->printer->prefix;
 355       tree abstract_origin = diagnostic->abstract_origin;
 356       char *new_prefix = (file && abstract_origin == NULL)
 357                          ? file_name_as_prefix (file) : NULL;
 358
 359       pp_set_prefix (context->printer, new_prefix);
 360
 361       if (current_function_decl == NULL)
 362         pp_printf (context->printer, _("At top level:"));
 363       else
 364         {
 365           tree fndecl, ao;
 366
 367           if (abstract_origin)
 368             {
 369               ao = BLOCK_ABSTRACT_ORIGIN (abstract_origin);
 370               while (TREE_CODE (ao) == BLOCK
 371                      && BLOCK_ABSTRACT_ORIGIN (ao)
 372                      && BLOCK_ABSTRACT_ORIGIN (ao) != ao)
 373                 ao = BLOCK_ABSTRACT_ORIGIN (ao);
 374               gcc_assert (TREE_CODE (ao) == FUNCTION_DECL);
 375               fndecl = ao;
 376             }
 377           else
 378             fndecl = current_function_decl;
 379
 380           if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
 381             pp_printf
 382               (context->printer, _("In member function %qs"),
 383                identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
 384           else
 385             pp_printf
 386               (context->printer, _("In function %qs"),
 387                identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
 388
 389           while (abstract_origin)
 390             {
 391               location_t *locus;
 392               tree block = abstract_origin;
 393
 394               locus = &BLOCK_SOURCE_LOCATION (block);
 395               fndecl = NULL;
 396               block = BLOCK_SUPERCONTEXT (block);
 397               while (block && TREE_CODE (block) == BLOCK
 398                      && BLOCK_ABSTRACT_ORIGIN (block))
 399                 {
 400                   ao = BLOCK_ABSTRACT_ORIGIN (block);
 401
 402                   while (TREE_CODE (ao) == BLOCK
 403                          && BLOCK_ABSTRACT_ORIGIN (ao)
 404                          && BLOCK_ABSTRACT_ORIGIN (ao) != ao)
 405                     ao = BLOCK_ABSTRACT_ORIGIN (ao);
 406
 407                   if (TREE_CODE (ao) == FUNCTION_DECL)
 408                     {
 409                       fndecl = ao;
 410                       break;
 411                     }
 412                   else if (TREE_CODE (ao) != BLOCK)
 413                     break;
 414
 415                   block = BLOCK_SUPERCONTEXT (block);
 416                 }
 417               if (fndecl)
 418                 abstract_origin = block;
 419               else
 420                 {
 421                   while (block && TREE_CODE (block) == BLOCK)
 422                     block = BLOCK_SUPERCONTEXT (block);
 423
 424                   if (block && TREE_CODE (block) == FUNCTION_DECL)
 425                     fndecl = block;
 426                   abstract_origin = NULL;
 427                 }
 428               if (fndecl)
 429                 {
 430                   expanded_location s = expand_location (*locus);
 431                   pp_character (context->printer, ',');
 432                   pp_newline (context->printer);
 433                   if (s.file != NULL)
 434                     {
 435                       if (flag_show_column && s.column != 0)
 436                         pp_printf (context->printer,
 437                                    _("    inlined from %qs at %s:%d:%d"),
 438                                    identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)),
 439                                    s.file, s.line, s.column);
 440                       else
 441                         pp_printf (context->printer,
 442                                    _("    inlined from %qs at %s:%d"),
 443                                    identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)),
 444                                    s.file, s.line);
 445
 446                     }
 447                   else
 448                     pp_printf (context->printer, _("    inlined from %qs"),
 449                                identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
 450                 }
 451             }
 452           pp_character (context->printer, ':');
 453         }
 454
 455       diagnostic_set_last_function (context, diagnostic);
 456       pp_flush (context->printer);
 457       context->printer->prefix = old_prefix;
 458       free ((char*) new_prefix);
 459     }
 460 }
 461
 462 tree
 463 lhd_callgraph_analyze_expr (tree *tp ATTRIBUTE_UNUSED,
 464                             int *walk_subtrees ATTRIBUTE_UNUSED)
 465 {
 466   return NULL;
 467 }
 468
 469 tree
 470 lhd_make_node (enum tree_code code)
 471 {
 472   return make_node (code);
 473 }
 474
 475 HOST_WIDE_INT
 476 lhd_to_target_charset (HOST_WIDE_INT c)
 477 {
 478   return c;
 479 }
 480
 481 tree
 482 lhd_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED, bool *se ATTRIBUTE_UNUSED)
 483 {
 484   return expr;
 485 }
 486
 487 /* Return sharing kind if OpenMP sharing attribute of DECL is
 488    predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 489
 490 enum omp_clause_default_kind
 491 lhd_omp_predetermined_sharing (tree decl ATTRIBUTE_UNUSED)
 492 {
 493   if (DECL_ARTIFICIAL (decl))
 494     return OMP_CLAUSE_DEFAULT_SHARED;
 495   return OMP_CLAUSE_DEFAULT_UNSPECIFIED;
 496 }
 497
 498 /* Generate code to copy SRC to DST.  */
 499
 500 tree
 501 lhd_omp_assignment (tree clause ATTRIBUTE_UNUSED, tree dst, tree src)
 502 {
 503   return build2 (MODIFY_EXPR, TREE_TYPE (dst), dst, src);
 504 }
 505
 506 /* Register language specific type size variables as potentially OpenMP
 507    firstprivate variables.  */
 508
 509 void
 510 lhd_omp_firstprivatize_type_sizes (struct gimplify_omp_ctx *c ATTRIBUTE_UNUSED,
 511                                    tree t ATTRIBUTE_UNUSED)
 512 {
 513 }
 514
 515 /* Common function for add_builtin_function and
 516    add_builtin_function_ext_scope.  */
 517 static tree
 518 add_builtin_function_common (const char *name,
 519                              tree type,
 520                              int function_code,
 521                              enum built_in_class cl,
 522                              const char *library_name,
 523                              tree attrs,
 524                              tree (*hook) (tree))
 525 {
 526   tree   id = get_identifier (name);
 527   tree decl = build_decl (FUNCTION_DECL, id, type);
 528
 529   TREE_PUBLIC (decl)         = 1;
 530   DECL_EXTERNAL (decl)       = 1;
 531   DECL_BUILT_IN_CLASS (decl) = cl;
 532
 533   DECL_FUNCTION_CODE (decl)  = (enum built_in_function) function_code;
 534
 535   /* DECL_FUNCTION_CODE is a bitfield; verify that the value fits.  */
 536   gcc_assert (DECL_FUNCTION_CODE (decl) == function_code);
 537
 538   if (library_name)
 539     {
 540       tree libname = get_identifier (library_name);
 541       SET_DECL_ASSEMBLER_NAME (decl, libname);
 542     }
 543
 544   /* Possibly apply some default attributes to this built-in function.  */
 545   if (attrs)
 546     decl_attributes (&decl, attrs, ATTR_FLAG_BUILT_IN);
 547   else
 548     decl_attributes (&decl, NULL_TREE, 0);
 549
 550   return hook (decl);
 551
 552 }
 553
 554 /* Create a builtin function.  */
 555
 556 tree
 557 add_builtin_function (const char *name,
 558                       tree type,
 559                       int function_code,
 560                       enum built_in_class cl,
 561                       const char *library_name,
 562                       tree attrs)
 563 {
 564   return add_builtin_function_common (name, type, function_code, cl,
 565                                       library_name, attrs,
 566                                       lang_hooks.builtin_function);
 567 }
 568
 569 /* Like add_builtin_function, but make sure the scope is the external scope.
 570    This is used to delay putting in back end builtin functions until the ISA
 571    that defines the builtin is declared via function specific target options,
 572    which can save memory for machines like the x86_64 that have multiple ISAs.
 573    If this points to the same function as builtin_function, the backend must
 574    add all of the builtins at program initialization time.  */
 575
 576 tree
 577 add_builtin_function_ext_scope (const char *name,
 578                                 tree type,
 579                                 int function_code,
 580                                 enum built_in_class cl,
 581                                 const char *library_name,
 582                                 tree attrs)
 583 {
 584   return add_builtin_function_common (name, type, function_code, cl,
 585                                       library_name, attrs,
 586                                       lang_hooks.builtin_function_ext_scope);
 587 }
 588
 589 tree
 590 lhd_builtin_function (tree decl)
 591 {
 592   lang_hooks.decls.pushdecl (decl);
 593   return decl;
 594 }