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 /* lang_hooks.decls.final_write_globals: perform final processing on
 304    global variables.  */
 305 void
 306 write_global_declarations (void)
 307 {
 308   /* Really define vars that have had only a tentative definition.
 309      Really output inline functions that must actually be callable
 310      and have not been output so far.  */
 311
 312   tree globals = lang_hooks.decls.getdecls ();
 313   int len = list_length (globals);
 314   tree *vec = XNEWVEC (tree, len);
 315   int i;
 316   tree decl;
 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 }