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.gimplify_expr re-writes *EXPR_P into GIMPLE form.  */
 264
 265 int
 266 lhd_gimplify_expr (tree *expr_p ATTRIBUTE_UNUSED,
 267                    gimple_seq *pre_p ATTRIBUTE_UNUSED,
 268                    gimple_seq *post_p ATTRIBUTE_UNUSED)
 269 {
 270   return GS_UNHANDLED;
 271 }
 272
 273 /* lang_hooks.tree_size: Determine the size of a tree with code C,
 274    which is a language-specific tree code in category tcc_constant or
 275    tcc_exceptional.  The default expects never to be called.  */
 276 size_t
 277 lhd_tree_size (enum tree_code c ATTRIBUTE_UNUSED)
 278 {
 279   gcc_unreachable ();
 280 }
 281
 282 /* Return true if decl, which is a function decl, may be called by a
 283    sibcall.  */
 284
 285 bool
 286 lhd_decl_ok_for_sibcall (const_tree decl ATTRIBUTE_UNUSED)
 287 {
 288   return true;
 289 }
 290
 291 /* lang_hooks.decls.final_write_globals: perform final processing on
 292    global variables.  */
 293 void
 294 write_global_declarations (void)
 295 {
 296   tree globals, decl, *vec;
 297   int len, i;
 298
 299   /* This lang hook is dual-purposed, and also finalizes the
 300      compilation unit.  */
 301   cgraph_finalize_compilation_unit ();
 302
 303   /* Really define vars that have had only a tentative definition.
 304      Really output inline functions that must actually be callable
 305      and have not been output so far.  */
 306
 307   globals = lang_hooks.decls.getdecls ();
 308   len = list_length (globals);
 309   vec = XNEWVEC (tree, len);
 310
 311   /* Process the decls in reverse order--earliest first.
 312      Put them into VEC from back to front, then take out from front.  */
 313
 314   for (i = 0, decl = globals; i < len; i++, decl = TREE_CHAIN (decl))
 315     vec[len - i - 1] = decl;
 316
 317   wrapup_global_declarations (vec, len);
 318   check_global_declarations (vec, len);
 319   emit_debug_global_declarations (vec, len);
 320
 321   /* Clean up.  */
 322   free (vec);
 323 }
 324
 325 /* Called to perform language-specific initialization of CTX.  */
 326 void
 327 lhd_initialize_diagnostics (struct diagnostic_context *ctx ATTRIBUTE_UNUSED)
 328 {
 329 }
 330
 331 /* The default function to print out name of current function that caused
 332    an error.  */
 333 void
 334 lhd_print_error_function (diagnostic_context *context, const char *file,
 335                           diagnostic_info *diagnostic)
 336 {
 337   if (diagnostic_last_function_changed (context, diagnostic))
 338     {
 339       const char *old_prefix = context->printer->prefix;
 340       tree abstract_origin = diagnostic->abstract_origin;
 341       char *new_prefix = (file && abstract_origin == NULL)
 342                          ? file_name_as_prefix (file) : NULL;
 343
 344       pp_set_prefix (context->printer, new_prefix);
 345
 346       if (current_function_decl == NULL)
 347         pp_printf (context->printer, _("At top level:"));
 348       else
 349         {
 350           tree fndecl, ao;
 351
 352           if (abstract_origin)
 353             {
 354               ao = BLOCK_ABSTRACT_ORIGIN (abstract_origin);
 355               while (TREE_CODE (ao) == BLOCK
 356                      && BLOCK_ABSTRACT_ORIGIN (ao)
 357                      && BLOCK_ABSTRACT_ORIGIN (ao) != ao)
 358                 ao = BLOCK_ABSTRACT_ORIGIN (ao);
 359               gcc_assert (TREE_CODE (ao) == FUNCTION_DECL);
 360               fndecl = ao;
 361             }
 362           else
 363             fndecl = current_function_decl;
 364
 365           if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
 366             pp_printf
 367               (context->printer, _("In member function %qs"),
 368                identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
 369           else
 370             pp_printf
 371               (context->printer, _("In function %qs"),
 372                identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
 373
 374           while (abstract_origin)
 375             {
 376               location_t *locus;
 377               tree block = abstract_origin;
 378
 379               locus = &BLOCK_SOURCE_LOCATION (block);
 380               fndecl = NULL;
 381               block = BLOCK_SUPERCONTEXT (block);
 382               while (block && TREE_CODE (block) == BLOCK
 383                      && BLOCK_ABSTRACT_ORIGIN (block))
 384                 {
 385                   ao = BLOCK_ABSTRACT_ORIGIN (block);
 386
 387                   while (TREE_CODE (ao) == BLOCK
 388                          && BLOCK_ABSTRACT_ORIGIN (ao)
 389                          && BLOCK_ABSTRACT_ORIGIN (ao) != ao)
 390                     ao = BLOCK_ABSTRACT_ORIGIN (ao);
 391
 392                   if (TREE_CODE (ao) == FUNCTION_DECL)
 393                     {
 394                       fndecl = ao;
 395                       break;
 396                     }
 397                   else if (TREE_CODE (ao) != BLOCK)
 398                     break;
 399
 400                   block = BLOCK_SUPERCONTEXT (block);
 401                 }
 402               if (fndecl)
 403                 abstract_origin = block;
 404               else
 405                 {
 406                   while (block && TREE_CODE (block) == BLOCK)
 407                     block = BLOCK_SUPERCONTEXT (block);
 408
 409                   if (block && TREE_CODE (block) == FUNCTION_DECL)
 410                     fndecl = block;
 411                   abstract_origin = NULL;
 412                 }
 413               if (fndecl)
 414                 {
 415                   expanded_location s = expand_location (*locus);
 416                   pp_character (context->printer, ',');
 417                   pp_newline (context->printer);
 418                   if (s.file != NULL)
 419                     {
 420                       if (flag_show_column)
 421                         pp_printf (context->printer,
 422                                    _("    inlined from %qs at %s:%d:%d"),
 423                                    identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)),
 424                                    s.file, s.line, s.column);
 425                       else
 426                         pp_printf (context->printer,
 427                                    _("    inlined from %qs at %s:%d"),
 428                                    identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)),
 429                                    s.file, s.line);
 430
 431                     }
 432                   else
 433                     pp_printf (context->printer, _("    inlined from %qs"),
 434                                identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
 435                 }
 436             }
 437           pp_character (context->printer, ':');
 438         }
 439
 440       diagnostic_set_last_function (context, diagnostic);
 441       pp_flush (context->printer);
 442       context->printer->prefix = old_prefix;
 443       free ((char*) new_prefix);
 444     }
 445 }
 446
 447 tree
 448 lhd_callgraph_analyze_expr (tree *tp ATTRIBUTE_UNUSED,
 449                             int *walk_subtrees ATTRIBUTE_UNUSED)
 450 {
 451   return NULL;
 452 }
 453
 454 tree
 455 lhd_make_node (enum tree_code code)
 456 {
 457   return make_node (code);
 458 }
 459
 460 HOST_WIDE_INT
 461 lhd_to_target_charset (HOST_WIDE_INT c)
 462 {
 463   return c;
 464 }
 465
 466 tree
 467 lhd_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED, bool *se ATTRIBUTE_UNUSED)
 468 {
 469   return expr;
 470 }
 471
 472 /* Return sharing kind if OpenMP sharing attribute of DECL is
 473    predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 474
 475 enum omp_clause_default_kind
 476 lhd_omp_predetermined_sharing (tree decl ATTRIBUTE_UNUSED)
 477 {
 478   if (DECL_ARTIFICIAL (decl))
 479     return OMP_CLAUSE_DEFAULT_SHARED;
 480   return OMP_CLAUSE_DEFAULT_UNSPECIFIED;
 481 }
 482
 483 /* Generate code to copy SRC to DST.  */
 484
 485 tree
 486 lhd_omp_assignment (tree clause ATTRIBUTE_UNUSED, tree dst, tree src)
 487 {
 488   return build2 (MODIFY_EXPR, TREE_TYPE (dst), dst, src);
 489 }
 490
 491 /* Register language specific type size variables as potentially OpenMP
 492    firstprivate variables.  */
 493
 494 void
 495 lhd_omp_firstprivatize_type_sizes (struct gimplify_omp_ctx *c ATTRIBUTE_UNUSED,
 496                                    tree t ATTRIBUTE_UNUSED)
 497 {
 498 }
 499
 500 /* Common function for add_builtin_function and
 501    add_builtin_function_ext_scope.  */
 502 static tree
 503 add_builtin_function_common (const char *name,
 504                              tree type,
 505                              int function_code,
 506                              enum built_in_class cl,
 507                              const char *library_name,
 508                              tree attrs,
 509                              tree (*hook) (tree))
 510 {
 511   tree   id = get_identifier (name);
 512   tree decl = build_decl (BUILTINS_LOCATION, FUNCTION_DECL, id, type);
 513
 514   TREE_PUBLIC (decl)         = 1;
 515   DECL_EXTERNAL (decl)       = 1;
 516   DECL_BUILT_IN_CLASS (decl) = cl;
 517
 518   DECL_FUNCTION_CODE (decl)  = (enum built_in_function) function_code;
 519
 520   /* DECL_FUNCTION_CODE is a bitfield; verify that the value fits.  */
 521   gcc_assert (DECL_FUNCTION_CODE (decl) == function_code);
 522
 523   if (library_name)
 524     {
 525       tree libname = get_identifier (library_name);
 526       SET_DECL_ASSEMBLER_NAME (decl, libname);
 527     }
 528
 529   /* Possibly apply some default attributes to this built-in function.  */
 530   if (attrs)
 531     decl_attributes (&decl, attrs, ATTR_FLAG_BUILT_IN);
 532   else
 533     decl_attributes (&decl, NULL_TREE, 0);
 534
 535   return hook (decl);
 536
 537 }
 538
 539 /* Create a builtin function.  */
 540
 541 tree
 542 add_builtin_function (const char *name,
 543                       tree type,
 544                       int function_code,
 545                       enum built_in_class cl,
 546                       const char *library_name,
 547                       tree attrs)
 548 {
 549   return add_builtin_function_common (name, type, function_code, cl,
 550                                       library_name, attrs,
 551                                       lang_hooks.builtin_function);
 552 }
 553
 554 /* Like add_builtin_function, but make sure the scope is the external scope.
 555    This is used to delay putting in back end builtin functions until the ISA
 556    that defines the builtin is declared via function specific target options,
 557    which can save memory for machines like the x86_64 that have multiple ISAs.
 558    If this points to the same function as builtin_function, the backend must
 559    add all of the builtins at program initialization time.  */
 560
 561 tree
 562 add_builtin_function_ext_scope (const char *name,
 563                                 tree type,
 564                                 int function_code,
 565                                 enum built_in_class cl,
 566                                 const char *library_name,
 567                                 tree attrs)
 568 {
 569   return add_builtin_function_common (name, type, function_code, cl,
 570                                       library_name, attrs,
 571                                       lang_hooks.builtin_function_ext_scope);
 572 }
 573
 574 tree
 575 lhd_builtin_function (tree decl)
 576 {
 577   lang_hooks.decls.pushdecl (decl);
 578   return decl;
 579 }