gcc/langhooks.c

   1 /* Default language-specific hooks.
   2    Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
   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 "tree-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   return false;
 109 }
 110
 111 /* Called from by print-tree.c.  */
 112
 113 void
 114 lhd_print_tree_nothing (FILE * ARG_UNUSED (file),
 115                         tree ARG_UNUSED (node),
 116                         int ARG_UNUSED (indent))
 117 {
 118 }
 119
 120 /* Called from staticp.  */
 121
 122 tree
 123 lhd_staticp (tree ARG_UNUSED (exp))
 124 {
 125   return NULL;
 126 }
 127
 128 /* Called from check_global_declarations.  */
 129
 130 bool
 131 lhd_warn_unused_global_decl (const_tree decl)
 132 {
 133   /* This is what used to exist in check_global_declarations.  Probably
 134      not many of these actually apply to non-C languages.  */
 135
 136   if (TREE_CODE (decl) == FUNCTION_DECL && DECL_INLINE (decl))
 137     return false;
 138   if (TREE_CODE (decl) == VAR_DECL && TREE_READONLY (decl))
 139     return false;
 140   if (DECL_IN_SYSTEM_HEADER (decl))
 141     return false;
 142
 143   return true;
 144 }
 145
 146 /* Set the DECL_ASSEMBLER_NAME for DECL.  */
 147 void
 148 lhd_set_decl_assembler_name (tree decl)
 149 {
 150   tree id;
 151
 152   /* The language-independent code should never use the
 153      DECL_ASSEMBLER_NAME for lots of DECLs.  Only FUNCTION_DECLs and
 154      VAR_DECLs for variables with static storage duration need a real
 155      DECL_ASSEMBLER_NAME.  */
 156   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
 157               || (TREE_CODE (decl) == VAR_DECL
 158                   && (TREE_STATIC (decl)
 159                       || DECL_EXTERNAL (decl)
 160                       || TREE_PUBLIC (decl))));
 161
 162   /* By default, assume the name to use in assembly code is the same
 163      as that used in the source language.  (That's correct for C, and
 164      GCC used to set DECL_ASSEMBLER_NAME to the same value as
 165      DECL_NAME in build_decl, so this choice provides backwards
 166      compatibility with existing front-ends.  This assumption is wrapped
 167      in a target hook, to allow for target-specific modification of the
 168      identifier.
 169
 170      Can't use just the variable's own name for a variable whose scope
 171      is less than the whole compilation.  Concatenate a distinguishing
 172      number - we use the DECL_UID.  */
 173
 174   if (TREE_PUBLIC (decl) || DECL_CONTEXT (decl) == NULL_TREE)
 175     id = targetm.mangle_decl_assembler_name (decl, DECL_NAME (decl));
 176   else
 177     {
 178       const char *name = IDENTIFIER_POINTER (DECL_NAME (decl));
 179       char *label;
 180
 181       ASM_FORMAT_PRIVATE_NAME (label, name, DECL_UID (decl));
 182       id = get_identifier (label);
 183     }
 184   SET_DECL_ASSEMBLER_NAME (decl, id);
 185
 186 }
 187
 188 /* Type promotion for variable arguments.  */
 189 tree
 190 lhd_type_promotes_to (tree ARG_UNUSED (type))
 191 {
 192   gcc_unreachable ();
 193 }
 194
 195 /* Registration of machine- or os-specific builtin types.  */
 196 void
 197 lhd_register_builtin_type (tree ARG_UNUSED (type),
 198                            const char * ARG_UNUSED (name))
 199 {
 200 }
 201
 202 /* Invalid use of an incomplete type.  */
 203 void
 204 lhd_incomplete_type_error (const_tree ARG_UNUSED (value), const_tree type)
 205 {
 206   gcc_assert (TREE_CODE (type) == ERROR_MARK);
 207   return;
 208 }
 209
 210 /* Provide a default routine for alias sets that always returns -1.  This
 211    is used by languages that don't need to do anything special.  */
 212
 213 alias_set_type
 214 lhd_get_alias_set (tree ARG_UNUSED (t))
 215 {
 216   return -1;
 217 }
 218
 219 /* This is the default expand_expr function.  */
 220
 221 rtx
 222 lhd_expand_expr (tree ARG_UNUSED (t), rtx ARG_UNUSED (r),
 223                  enum machine_mode ARG_UNUSED (mm),
 224                  int ARG_UNUSED (em),
 225                  rtx * ARG_UNUSED (a))
 226 {
 227   gcc_unreachable ();
 228 }
 229
 230 /* The default language-specific function for expanding a decl.  After
 231    the language-independent cases are handled, this function will be
 232    called.  If this function is not defined, it is assumed that
 233    declarations other than those for variables and labels do not require
 234    any RTL generation.  */
 235
 236 int
 237 lhd_expand_decl (tree ARG_UNUSED (t))
 238 {
 239   return 0;
 240 }
 241
 242 /* This is the default decl_printable_name function.  */
 243
 244 const char *
 245 lhd_decl_printable_name (tree decl, int ARG_UNUSED (verbosity))
 246 {
 247   gcc_assert (decl && DECL_NAME (decl));
 248   return IDENTIFIER_POINTER (DECL_NAME (decl));
 249 }
 250
 251 /* This is the default dwarf_name function.  */
 252
 253 const char *
 254 lhd_dwarf_name (tree t, int verbosity)
 255 {
 256   gcc_assert (DECL_P (t));
 257
 258   return lang_hooks.decl_printable_name (t, verbosity);
 259 }
 260
 261 /* This compares two types for equivalence ("compatible" in C-based languages).
 262    This routine should only return 1 if it is sure.  It should not be used
 263    in contexts where erroneously returning 0 causes problems.  */
 264
 265 int
 266 lhd_types_compatible_p (tree x, tree y)
 267 {
 268   return TYPE_MAIN_VARIANT (x) == TYPE_MAIN_VARIANT (y);
 269 }
 270
 271 /* lang_hooks.tree_dump.dump_tree:  Dump language-specific parts of tree
 272    nodes.  Returns nonzero if it does not want the usual dumping of the
 273    second argument.  */
 274
 275 bool
 276 lhd_tree_dump_dump_tree (void *di ATTRIBUTE_UNUSED, tree t ATTRIBUTE_UNUSED)
 277 {
 278   return false;
 279 }
 280
 281 /* lang_hooks.tree_dump.type_qual:  Determine type qualifiers in a
 282    language-specific way.  */
 283
 284 int
 285 lhd_tree_dump_type_quals (const_tree t)
 286 {
 287   return TYPE_QUALS (t);
 288 }
 289
 290 /* lang_hooks.expr_size: Determine the size of the value of an expression T
 291    in a language-specific way.  Returns a tree for the size in bytes.  */
 292
 293 tree
 294 lhd_expr_size (const_tree exp)
 295 {
 296   if (DECL_P (exp)
 297       && DECL_SIZE_UNIT (exp) != 0)
 298     return DECL_SIZE_UNIT (exp);
 299   else
 300     return size_in_bytes (TREE_TYPE (exp));
 301 }
 302
 303 /* lang_hooks.gimplify_expr re-writes *EXPR_P into GIMPLE form.  */
 304
 305 int
 306 lhd_gimplify_expr (tree *expr_p ATTRIBUTE_UNUSED, tree *pre_p ATTRIBUTE_UNUSED,
 307                    tree *post_p ATTRIBUTE_UNUSED)
 308 {
 309   return GS_UNHANDLED;
 310 }
 311
 312 /* lang_hooks.tree_size: Determine the size of a tree with code C,
 313    which is a language-specific tree code in category tcc_constant or
 314    tcc_exceptional.  The default expects never to be called.  */
 315 size_t
 316 lhd_tree_size (enum tree_code c ATTRIBUTE_UNUSED)
 317 {
 318   gcc_unreachable ();
 319 }
 320
 321 /* Return true if decl, which is a function decl, may be called by a
 322    sibcall.  */
 323
 324 bool
 325 lhd_decl_ok_for_sibcall (const_tree decl ATTRIBUTE_UNUSED)
 326 {
 327   return true;
 328 }
 329
 330 /* Return the COMDAT group into which DECL should be placed.  */
 331
 332 const char *
 333 lhd_comdat_group (tree decl)
 334 {
 335   return IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
 336 }
 337
 338 /* lang_hooks.decls.final_write_globals: perform final processing on
 339    global variables.  */
 340 void
 341 write_global_declarations (void)
 342 {
 343   /* Really define vars that have had only a tentative definition.
 344      Really output inline functions that must actually be callable
 345      and have not been output so far.  */
 346
 347   tree globals = lang_hooks.decls.getdecls ();
 348   int len = list_length (globals);
 349   tree *vec = XNEWVEC (tree, len);
 350   int i;
 351   tree decl;
 352
 353   /* Process the decls in reverse order--earliest first.
 354      Put them into VEC from back to front, then take out from front.  */
 355
 356   for (i = 0, decl = globals; i < len; i++, decl = TREE_CHAIN (decl))
 357     vec[len - i - 1] = decl;
 358
 359   wrapup_global_declarations (vec, len);
 360   check_global_declarations (vec, len);
 361   emit_debug_global_declarations (vec, len);
 362
 363   /* Clean up.  */
 364   free (vec);
 365 }
 366
 367 /* Called to perform language-specific initialization of CTX.  */
 368 void
 369 lhd_initialize_diagnostics (struct diagnostic_context *ctx ATTRIBUTE_UNUSED)
 370 {
 371 }
 372
 373 /* The default function to print out name of current function that caused
 374    an error.  */
 375 void
 376 lhd_print_error_function (diagnostic_context *context, const char *file,
 377                           diagnostic_info *diagnostic)
 378 {
 379   if (diagnostic_last_function_changed (context, diagnostic))
 380     {
 381       const char *old_prefix = context->printer->prefix;
 382       tree abstract_origin = diagnostic->abstract_origin;
 383       char *new_prefix = (file && abstract_origin == NULL)
 384                          ? file_name_as_prefix (file) : NULL;
 385
 386       pp_set_prefix (context->printer, new_prefix);
 387
 388       if (current_function_decl == NULL)
 389         pp_printf (context->printer, _("At top level:"));
 390       else
 391         {
 392           tree fndecl, ao;
 393
 394           if (abstract_origin)
 395             {
 396               ao = BLOCK_ABSTRACT_ORIGIN (abstract_origin);
 397               while (TREE_CODE (ao) == BLOCK && BLOCK_ABSTRACT_ORIGIN (ao))
 398                 ao = BLOCK_ABSTRACT_ORIGIN (ao);
 399               gcc_assert (TREE_CODE (ao) == FUNCTION_DECL);
 400               fndecl = ao;
 401             }
 402           else
 403             fndecl = current_function_decl;
 404
 405           if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
 406             pp_printf
 407               (context->printer, _("In member function %qs"),
 408                lang_hooks.decl_printable_name (fndecl, 2));
 409           else
 410             pp_printf
 411               (context->printer, _("In function %qs"),
 412                lang_hooks.decl_printable_name (fndecl, 2));
 413
 414           while (abstract_origin)
 415             {
 416               location_t *locus;
 417               tree block = abstract_origin;
 418
 419               locus = &BLOCK_SOURCE_LOCATION (block);
 420               fndecl = NULL;
 421               block = BLOCK_SUPERCONTEXT (block);
 422               while (block && TREE_CODE (block) == BLOCK
 423                      && BLOCK_ABSTRACT_ORIGIN (block))
 424                 {
 425                   ao = BLOCK_ABSTRACT_ORIGIN (block);
 426
 427                   while (TREE_CODE (ao) == BLOCK && BLOCK_ABSTRACT_ORIGIN (ao))
 428                     ao = BLOCK_ABSTRACT_ORIGIN (ao);
 429
 430                   if (TREE_CODE (ao) == FUNCTION_DECL)
 431                     {
 432                       fndecl = ao;
 433                       break;
 434                     }
 435                   else if (TREE_CODE (ao) != BLOCK)
 436                     break;
 437
 438                   block = BLOCK_SUPERCONTEXT (block);
 439                 }
 440               if (fndecl)
 441                 abstract_origin = block;
 442               else
 443                 {
 444                   while (block && TREE_CODE (block) == BLOCK)
 445                     block = BLOCK_SUPERCONTEXT (block);
 446
 447                   if (TREE_CODE (block) == FUNCTION_DECL)
 448                     fndecl = block;
 449                   abstract_origin = NULL;
 450                 }
 451               if (fndecl)
 452                 {
 453                   expanded_location s = expand_location (*locus);
 454                   pp_character (context->printer, ',');
 455                   pp_newline (context->printer);
 456                   if (s.file != NULL)
 457                     {
 458                       if (flag_show_column && s.column != 0)
 459                         pp_printf (context->printer,
 460                                    _("    inlined from %qs at %s:%d:%d"),
 461                                    lang_hooks.decl_printable_name (fndecl, 2),
 462                                    s.file, s.line, s.column);
 463                       else
 464                         pp_printf (context->printer,
 465                                    _("    inlined from %qs at %s:%d"),
 466                                    lang_hooks.decl_printable_name (fndecl, 2),
 467                                    s.file, s.line);
 468
 469                     }
 470                   else
 471                     pp_printf (context->printer, _("    inlined from %qs"),
 472                                lang_hooks.decl_printable_name (fndecl, 2));
 473                 }
 474             }
 475           pp_character (context->printer, ':');
 476         }
 477
 478       diagnostic_set_last_function (context, diagnostic);
 479       pp_flush (context->printer);
 480       context->printer->prefix = old_prefix;
 481       free ((char*) new_prefix);
 482     }
 483 }
 484
 485 tree
 486 lhd_callgraph_analyze_expr (tree *tp ATTRIBUTE_UNUSED,
 487                             int *walk_subtrees ATTRIBUTE_UNUSED)
 488 {
 489   return NULL;
 490 }
 491
 492 tree
 493 lhd_make_node (enum tree_code code)
 494 {
 495   return make_node (code);
 496 }
 497
 498 HOST_WIDE_INT
 499 lhd_to_target_charset (HOST_WIDE_INT c)
 500 {
 501   return c;
 502 }
 503
 504 tree
 505 lhd_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED,
 506                   bool *ti ATTRIBUTE_UNUSED, bool *se ATTRIBUTE_UNUSED)
 507 {
 508   return expr;
 509 }
 510
 511 /* Return sharing kind if OpenMP sharing attribute of DECL is
 512    predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 513
 514 enum omp_clause_default_kind
 515 lhd_omp_predetermined_sharing (tree decl ATTRIBUTE_UNUSED)
 516 {
 517   if (DECL_ARTIFICIAL (decl))
 518     return OMP_CLAUSE_DEFAULT_SHARED;
 519   return OMP_CLAUSE_DEFAULT_UNSPECIFIED;
 520 }
 521
 522 /* Generate code to copy SRC to DST.  */
 523
 524 tree
 525 lhd_omp_assignment (tree clause ATTRIBUTE_UNUSED, tree dst, tree src)
 526 {
 527   return build_gimple_modify_stmt (dst, src);
 528 }
 529
 530 /* Register language specific type size variables as potentially OpenMP
 531    firstprivate variables.  */
 532
 533 void
 534 lhd_omp_firstprivatize_type_sizes (struct gimplify_omp_ctx *c ATTRIBUTE_UNUSED,
 535                                    tree t ATTRIBUTE_UNUSED)
 536 {
 537 }
 538
 539 tree
 540 add_builtin_function (const char *name,
 541                       tree type,
 542                       int function_code,
 543                       enum built_in_class cl,
 544                       const char *library_name,
 545                       tree attrs)
 546 {
 547   tree   id = get_identifier (name);
 548   tree decl = build_decl (FUNCTION_DECL, id, type);
 549
 550   TREE_PUBLIC (decl)         = 1;
 551   DECL_EXTERNAL (decl)       = 1;
 552   DECL_BUILT_IN_CLASS (decl) = cl;
 553
 554   DECL_FUNCTION_CODE (decl)  = -1;
 555   gcc_assert (DECL_FUNCTION_CODE (decl) >= function_code);
 556   DECL_FUNCTION_CODE (decl)  = function_code;
 557
 558   if (library_name)
 559     {
 560       tree libname = get_identifier (library_name);
 561       SET_DECL_ASSEMBLER_NAME (decl, libname);
 562     }
 563
 564   /* Possibly apply some default attributes to this built-in function.  */
 565   if (attrs)
 566     decl_attributes (&decl, attrs, ATTR_FLAG_BUILT_IN);
 567   else
 568     decl_attributes (&decl, NULL_TREE, 0);
 569
 570   return lang_hooks.builtin_function (decl);
 571
 572 }
 573
 574 tree
 575 lhd_builtin_function (tree decl)
 576 {
 577   lang_hooks.decls.pushdecl (decl);
 578   return decl;
 579 }