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