gcc/langhooks.c

   1 /* Default language-specific hooks.
   2    Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007
   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 the tree node passed).  */
  80
  81 tree
  82 lhd_return_tree (tree t)
  83 {
  84   return t;
  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   return false;
 117 }
 118
 119 /* Called from by print-tree.c.  */
 120
 121 void
 122 lhd_print_tree_nothing (FILE * ARG_UNUSED (file),
 123                         tree ARG_UNUSED (node),
 124                         int ARG_UNUSED (indent))
 125 {
 126 }
 127
 128 /* Called from staticp.  */
 129
 130 tree
 131 lhd_staticp (tree ARG_UNUSED (exp))
 132 {
 133   return NULL;
 134 }
 135
 136 /* Called from check_global_declarations.  */
 137
 138 bool
 139 lhd_warn_unused_global_decl (const_tree decl)
 140 {
 141   /* This is what used to exist in check_global_declarations.  Probably
 142      not many of these actually apply to non-C languages.  */
 143
 144   if (TREE_CODE (decl) == FUNCTION_DECL && DECL_INLINE (decl))
 145     return false;
 146   if (TREE_CODE (decl) == VAR_DECL && TREE_READONLY (decl))
 147     return false;
 148   if (DECL_IN_SYSTEM_HEADER (decl))
 149     return false;
 150
 151   return true;
 152 }
 153
 154 /* Set the DECL_ASSEMBLER_NAME for DECL.  */
 155 void
 156 lhd_set_decl_assembler_name (tree decl)
 157 {
 158   tree id;
 159
 160   /* The language-independent code should never use the
 161      DECL_ASSEMBLER_NAME for lots of DECLs.  Only FUNCTION_DECLs and
 162      VAR_DECLs for variables with static storage duration need a real
 163      DECL_ASSEMBLER_NAME.  */
 164   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
 165               || (TREE_CODE (decl) == VAR_DECL
 166                   && (TREE_STATIC (decl)
 167                       || DECL_EXTERNAL (decl)
 168                       || TREE_PUBLIC (decl))));
 169
 170   /* By default, assume the name to use in assembly code is the same
 171      as that used in the source language.  (That's correct for C, and
 172      GCC used to set DECL_ASSEMBLER_NAME to the same value as
 173      DECL_NAME in build_decl, so this choice provides backwards
 174      compatibility with existing front-ends.  This assumption is wrapped
 175      in a target hook, to allow for target-specific modification of the
 176      identifier.
 177
 178      Can't use just the variable's own name for a variable whose scope
 179      is less than the whole compilation.  Concatenate a distinguishing
 180      number - we use the DECL_UID.  */
 181
 182   if (TREE_PUBLIC (decl) || DECL_CONTEXT (decl) == NULL_TREE)
 183     id = targetm.mangle_decl_assembler_name (decl, DECL_NAME (decl));
 184   else
 185     {
 186       const char *name = IDENTIFIER_POINTER (DECL_NAME (decl));
 187       char *label;
 188
 189       ASM_FORMAT_PRIVATE_NAME (label, name, DECL_UID (decl));
 190       id = get_identifier (label);
 191     }
 192   SET_DECL_ASSEMBLER_NAME (decl, id);
 193
 194 }
 195
 196 /* Type promotion for variable arguments.  */
 197 tree
 198 lhd_type_promotes_to (tree ARG_UNUSED (type))
 199 {
 200   gcc_unreachable ();
 201 }
 202
 203 /* Registration of machine- or os-specific builtin types.  */
 204 void
 205 lhd_register_builtin_type (tree ARG_UNUSED (type),
 206                            const char * ARG_UNUSED (name))
 207 {
 208 }
 209
 210 /* Invalid use of an incomplete type.  */
 211 void
 212 lhd_incomplete_type_error (const_tree ARG_UNUSED (value), const_tree type)
 213 {
 214   gcc_assert (TREE_CODE (type) == ERROR_MARK);
 215   return;
 216 }
 217
 218 /* Provide a default routine for alias sets that always returns -1.  This
 219    is used by languages that don't need to do anything special.  */
 220
 221 alias_set_type
 222 lhd_get_alias_set (tree ARG_UNUSED (t))
 223 {
 224   return -1;
 225 }
 226
 227 /* This is the default expand_expr function.  */
 228
 229 rtx
 230 lhd_expand_expr (tree ARG_UNUSED (t), rtx ARG_UNUSED (r),
 231                  enum machine_mode ARG_UNUSED (mm),
 232                  int ARG_UNUSED (em),
 233                  rtx * ARG_UNUSED (a))
 234 {
 235   gcc_unreachable ();
 236 }
 237
 238 /* The default language-specific function for expanding a decl.  After
 239    the language-independent cases are handled, this function will be
 240    called.  If this function is not defined, it is assumed that
 241    declarations other than those for variables and labels do not require
 242    any RTL generation.  */
 243
 244 int
 245 lhd_expand_decl (tree ARG_UNUSED (t))
 246 {
 247   return 0;
 248 }
 249
 250 /* This is the default decl_printable_name function.  */
 251
 252 const char *
 253 lhd_decl_printable_name (tree decl, int ARG_UNUSED (verbosity))
 254 {
 255   gcc_assert (decl && DECL_NAME (decl));
 256   return IDENTIFIER_POINTER (DECL_NAME (decl));
 257 }
 258
 259 /* This is the default dwarf_name function.  */
 260
 261 const char *
 262 lhd_dwarf_name (tree t, int verbosity)
 263 {
 264   gcc_assert (DECL_P (t));
 265
 266   return lang_hooks.decl_printable_name (t, verbosity);
 267 }
 268
 269 /* This compares two types for equivalence ("compatible" in C-based languages).
 270    This routine should only return 1 if it is sure.  It should not be used
 271    in contexts where erroneously returning 0 causes problems.  */
 272
 273 int
 274 lhd_types_compatible_p (tree x, tree y)
 275 {
 276   return TYPE_MAIN_VARIANT (x) == TYPE_MAIN_VARIANT (y);
 277 }
 278
 279 /* lang_hooks.tree_dump.dump_tree:  Dump language-specific parts of tree
 280    nodes.  Returns nonzero if it does not want the usual dumping of the
 281    second argument.  */
 282
 283 bool
 284 lhd_tree_dump_dump_tree (void *di ATTRIBUTE_UNUSED, tree t ATTRIBUTE_UNUSED)
 285 {
 286   return false;
 287 }
 288
 289 /* lang_hooks.tree_dump.type_qual:  Determine type qualifiers in a
 290    language-specific way.  */
 291
 292 int
 293 lhd_tree_dump_type_quals (const_tree t)
 294 {
 295   return TYPE_QUALS (t);
 296 }
 297
 298 /* lang_hooks.expr_size: Determine the size of the value of an expression T
 299    in a language-specific way.  Returns a tree for the size in bytes.  */
 300
 301 tree
 302 lhd_expr_size (const_tree exp)
 303 {
 304   if (DECL_P (exp)
 305       && DECL_SIZE_UNIT (exp) != 0)
 306     return DECL_SIZE_UNIT (exp);
 307   else
 308     return size_in_bytes (TREE_TYPE (exp));
 309 }
 310
 311 /* lang_hooks.gimplify_expr re-writes *EXPR_P into GIMPLE form.  */
 312
 313 int
 314 lhd_gimplify_expr (tree *expr_p ATTRIBUTE_UNUSED, tree *pre_p ATTRIBUTE_UNUSED,
 315                    tree *post_p ATTRIBUTE_UNUSED)
 316 {
 317   return GS_UNHANDLED;
 318 }
 319
 320 /* lang_hooks.tree_size: Determine the size of a tree with code C,
 321    which is a language-specific tree code in category tcc_constant or
 322    tcc_exceptional.  The default expects never to be called.  */
 323 size_t
 324 lhd_tree_size (enum tree_code c ATTRIBUTE_UNUSED)
 325 {
 326   gcc_unreachable ();
 327 }
 328
 329 /* Return true if decl, which is a function decl, may be called by a
 330    sibcall.  */
 331
 332 bool
 333 lhd_decl_ok_for_sibcall (tree decl ATTRIBUTE_UNUSED)
 334 {
 335   return true;
 336 }
 337
 338 /* Return the COMDAT group into which DECL should be placed.  */
 339
 340 const char *
 341 lhd_comdat_group (tree decl)
 342 {
 343   return IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
 344 }
 345
 346 /* lang_hooks.decls.final_write_globals: perform final processing on
 347    global variables.  */
 348 void
 349 write_global_declarations (void)
 350 {
 351   /* Really define vars that have had only a tentative definition.
 352      Really output inline functions that must actually be callable
 353      and have not been output so far.  */
 354
 355   tree globals = lang_hooks.decls.getdecls ();
 356   int len = list_length (globals);
 357   tree *vec = XNEWVEC (tree, len);
 358   int i;
 359   tree decl;
 360
 361   /* Process the decls in reverse order--earliest first.
 362      Put them into VEC from back to front, then take out from front.  */
 363
 364   for (i = 0, decl = globals; i < len; i++, decl = TREE_CHAIN (decl))
 365     vec[len - i - 1] = decl;
 366
 367   wrapup_global_declarations (vec, len);
 368   check_global_declarations (vec, len);
 369   emit_debug_global_declarations (vec, len);
 370
 371   /* Clean up.  */
 372   free (vec);
 373 }
 374
 375 /* Called to perform language-specific initialization of CTX.  */
 376 void
 377 lhd_initialize_diagnostics (struct diagnostic_context *ctx ATTRIBUTE_UNUSED)
 378 {
 379 }
 380
 381 /* The default function to print out name of current function that caused
 382    an error.  */
 383 void
 384 lhd_print_error_function (diagnostic_context *context, const char *file)
 385 {
 386   if (diagnostic_last_function_changed (context))
 387     {
 388       const char *old_prefix = context->printer->prefix;
 389       char *new_prefix = file ? file_name_as_prefix (file) : NULL;
 390
 391       pp_set_prefix (context->printer, new_prefix);
 392
 393       if (current_function_decl == NULL)
 394         pp_printf (context->printer, _("At top level:"));
 395       else
 396         {
 397           if (TREE_CODE (TREE_TYPE (current_function_decl)) == METHOD_TYPE)
 398             pp_printf
 399               (context->printer, _("In member function %qs:"),
 400                lang_hooks.decl_printable_name (current_function_decl, 2));
 401           else
 402             pp_printf
 403               (context->printer, _("In function %qs:"),
 404                lang_hooks.decl_printable_name (current_function_decl, 2));
 405         }
 406
 407       diagnostic_set_last_function (context);
 408       pp_flush (context->printer);
 409       context->printer->prefix = old_prefix;
 410       free ((char*) new_prefix);
 411     }
 412 }
 413
 414 tree
 415 lhd_callgraph_analyze_expr (tree *tp ATTRIBUTE_UNUSED,
 416                             int *walk_subtrees ATTRIBUTE_UNUSED,
 417                             tree decl ATTRIBUTE_UNUSED)
 418 {
 419   return NULL;
 420 }
 421
 422 tree
 423 lhd_make_node (enum tree_code code)
 424 {
 425   return make_node (code);
 426 }
 427
 428 HOST_WIDE_INT
 429 lhd_to_target_charset (HOST_WIDE_INT c)
 430 {
 431   return c;
 432 }
 433
 434 tree
 435 lhd_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED,
 436                   bool *ti ATTRIBUTE_UNUSED, bool *se ATTRIBUTE_UNUSED)
 437 {
 438   return expr;
 439 }
 440
 441 /* Return sharing kind if OpenMP sharing attribute of DECL is
 442    predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 443
 444 enum omp_clause_default_kind
 445 lhd_omp_predetermined_sharing (tree decl ATTRIBUTE_UNUSED)
 446 {
 447   if (DECL_ARTIFICIAL (decl))
 448     return OMP_CLAUSE_DEFAULT_SHARED;
 449   return OMP_CLAUSE_DEFAULT_UNSPECIFIED;
 450 }
 451
 452 /* Generate code to copy SRC to DST.  */
 453
 454 tree
 455 lhd_omp_assignment (tree clause ATTRIBUTE_UNUSED, tree dst, tree src)
 456 {
 457   return build_gimple_modify_stmt (dst, src);
 458 }
 459
 460 /* Register language specific type size variables as potentially OpenMP
 461    firstprivate variables.  */
 462
 463 void
 464 lhd_omp_firstprivatize_type_sizes (struct gimplify_omp_ctx *c ATTRIBUTE_UNUSED,
 465                                    tree t ATTRIBUTE_UNUSED)
 466 {
 467 }
 468
 469 tree
 470 add_builtin_function (const char *name,
 471                       tree type,
 472                       int function_code,
 473                       enum built_in_class cl,
 474                       const char *library_name,
 475                       tree attrs)
 476 {
 477   tree   id = get_identifier (name);
 478   tree decl = build_decl (FUNCTION_DECL, id, type);
 479
 480   TREE_PUBLIC (decl)         = 1;
 481   DECL_EXTERNAL (decl)       = 1;
 482   DECL_BUILT_IN_CLASS (decl) = cl;
 483   DECL_FUNCTION_CODE (decl)  = function_code;
 484
 485   if (library_name)
 486     {
 487       tree libname = get_identifier (library_name);
 488       SET_DECL_ASSEMBLER_NAME (decl, libname);
 489     }
 490
 491   /* Possibly apply some default attributes to this built-in function.  */
 492   if (attrs)
 493     decl_attributes (&decl, attrs, ATTR_FLAG_BUILT_IN);
 494   else
 495     decl_attributes (&decl, NULL_TREE, 0);
 496
 497   return lang_hooks.builtin_function (decl);
 498
 499 }
 500
 501 tree
 502 lhd_builtin_function (tree decl)
 503 {
 504   lang_hooks.decls.pushdecl (decl);
 505   return decl;
 506 }