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