gcc/langhooks.c

   1 /* Default language-specific hooks.
   2    Copyright 2001, 2002, 2003 Free Software Foundation, Inc.
   3    Contributed by Alexandre Oliva  <aoliva@redhat.com>
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "toplev.h"
  27 #include "tree.h"
  28 #include "tree-inline.h"
  29 #include "rtl.h"
  30 #include "insn-config.h"
  31 #include "integrate.h"
  32 #include "flags.h"
  33 #include "langhooks.h"
  34 #include "langhooks-def.h"
  35 #include "ggc.h"
  36 #include "diagnostic.h"
  37
  38 /* Do nothing; in many cases the default hook.  */
  39
  40 void
  41 lhd_do_nothing (void)
  42 {
  43 }
  44
  45 /* Do nothing (tree).  */
  46
  47 void
  48 lhd_do_nothing_t (tree t ATTRIBUTE_UNUSED)
  49 {
  50 }
  51
  52 /* Do nothing (int).  */
  53
  54 void
  55 lhd_do_nothing_i (int i ATTRIBUTE_UNUSED)
  56 {
  57 }
  58
  59 /* Do nothing (int, int, int).  Return NULL_TREE.  */
  60
  61 tree
  62 lhd_do_nothing_iii_return_null_tree (int i ATTRIBUTE_UNUSED,
  63                                      int j ATTRIBUTE_UNUSED,
  64                                      int k ATTRIBUTE_UNUSED)
  65 {
  66   return NULL_TREE;
  67 }
  68
  69 /* Do nothing (function).  */
  70
  71 void
  72 lhd_do_nothing_f (struct function *f ATTRIBUTE_UNUSED)
  73 {
  74 }
  75
  76 /* Do nothing (return the tree node passed).  */
  77
  78 tree
  79 lhd_return_tree (tree t)
  80 {
  81   return t;
  82 }
  83
  84 /* Do nothing (return NULL_TREE).  */
  85
  86 tree
  87 lhd_return_null_tree_v (void)
  88 {
  89   return NULL_TREE;
  90 }
  91
  92 /* Do nothing (return NULL_TREE).  */
  93
  94 tree
  95 lhd_return_null_tree (tree t ATTRIBUTE_UNUSED)
  96 {
  97   return NULL_TREE;
  98 }
  99
 100 /* The default post options hook.  */
 101
 102 bool
 103 lhd_post_options (const char **pfilename ATTRIBUTE_UNUSED)
 104 {
 105   return false;
 106 }
 107
 108 /* Called from by print-tree.c.  */
 109
 110 void
 111 lhd_print_tree_nothing (FILE *file ATTRIBUTE_UNUSED,
 112                         tree node ATTRIBUTE_UNUSED,
 113                         int indent ATTRIBUTE_UNUSED)
 114 {
 115 }
 116
 117 /* Called from safe_from_p.  */
 118
 119 int
 120 lhd_safe_from_p (rtx x ATTRIBUTE_UNUSED, tree exp ATTRIBUTE_UNUSED)
 121 {
 122   return 1;
 123 }
 124
 125 /* Called from unsafe_for_reeval.  */
 126
 127 int
 128 lhd_unsafe_for_reeval (tree t ATTRIBUTE_UNUSED)
 129 {
 130   return -1;
 131 }
 132
 133 /* Called from staticp.  */
 134
 135 int
 136 lhd_staticp (tree exp ATTRIBUTE_UNUSED)
 137 {
 138   return 0;
 139 }
 140
 141 /* Called from check_global_declarations.  */
 142
 143 bool
 144 lhd_warn_unused_global_decl (tree decl)
 145 {
 146   /* This is what used to exist in check_global_declarations.  Probably
 147      not many of these actually apply to non-C languages.  */
 148
 149   if (TREE_CODE (decl) == FUNCTION_DECL && DECL_INLINE (decl))
 150     return false;
 151   if (TREE_CODE (decl) == VAR_DECL && TREE_READONLY (decl))
 152     return false;
 153   if (DECL_IN_SYSTEM_HEADER (decl))
 154     return false;
 155
 156   return true;
 157 }
 158
 159 /* Number for making the label on the next
 160    static variable internal to a function.  */
 161
 162 static GTY(()) int var_labelno;
 163
 164 /* Set the DECL_ASSEMBLER_NAME for DECL.  */
 165 void
 166 lhd_set_decl_assembler_name (tree decl)
 167 {
 168   /* The language-independent code should never use the
 169      DECL_ASSEMBLER_NAME for lots of DECLs.  Only FUNCTION_DECLs and
 170      VAR_DECLs for variables with static storage duration need a real
 171      DECL_ASSEMBLER_NAME.  */
 172   if (TREE_CODE (decl) == FUNCTION_DECL
 173       || (TREE_CODE (decl) == VAR_DECL
 174           && (TREE_STATIC (decl)
 175               || DECL_EXTERNAL (decl)
 176               || TREE_PUBLIC (decl))))
 177     {
 178       /* By default, assume the name to use in assembly code is the
 179          same as that used in the source language.  (That's correct
 180          for C, and GCC used to set DECL_ASSEMBLER_NAME to the same
 181          value as DECL_NAME in build_decl, so this choice provides
 182          backwards compatibility with existing front-ends.
 183
 184          Can't use just the variable's own name for a variable whose
 185          scope is less than the whole compilation.  Concatenate a
 186          distinguishing number.  */
 187       if (!TREE_PUBLIC (decl) && DECL_CONTEXT (decl))
 188         {
 189           const char *name = IDENTIFIER_POINTER (DECL_NAME (decl));
 190           char *label;
 191
 192           ASM_FORMAT_PRIVATE_NAME (label, name, var_labelno);
 193           var_labelno++;
 194           SET_DECL_ASSEMBLER_NAME (decl, get_identifier (label));
 195         }
 196       else
 197         SET_DECL_ASSEMBLER_NAME (decl, DECL_NAME (decl));
 198     }
 199   else
 200     /* Nobody should ever be asking for the DECL_ASSEMBLER_NAME of
 201        these DECLs -- unless they're in language-dependent code, in
 202        which case set_decl_assembler_name hook should handle things.  */
 203     abort ();
 204 }
 205
 206 /* By default we always allow bit-field based optimizations.  */
 207 bool
 208 lhd_can_use_bit_fields_p (void)
 209 {
 210   return true;
 211 }
 212
 213 /* Provide a default routine to clear the binding stack.  This is used
 214    by languages that don't need to do anything special.  */
 215 void
 216 lhd_clear_binding_stack (void)
 217 {
 218   while (! (*lang_hooks.decls.global_bindings_p) ())
 219     poplevel (0, 0, 0);
 220 }
 221
 222 /* Type promotion for variable arguments.  */
 223 tree
 224 lhd_type_promotes_to (tree type ATTRIBUTE_UNUSED)
 225 {
 226   abort ();
 227 }
 228
 229 /* Registration of machine- or os-specific builtin types.  */
 230 void
 231 lhd_register_builtin_type (tree type ATTRIBUTE_UNUSED,
 232                            const char* name ATTRIBUTE_UNUSED)
 233 {
 234 }
 235
 236 /* Invalid use of an incomplete type.  */
 237 void
 238 lhd_incomplete_type_error (tree value ATTRIBUTE_UNUSED, tree type)
 239 {
 240   if (TREE_CODE (type) == ERROR_MARK)
 241     return;
 242
 243   abort ();
 244 }
 245
 246 /* Provide a default routine for alias sets that always returns -1.  This
 247    is used by languages that don't need to do anything special.  */
 248
 249 HOST_WIDE_INT
 250 lhd_get_alias_set (tree t ATTRIBUTE_UNUSED)
 251 {
 252   return -1;
 253 }
 254
 255 /* Provide a hook routine for alias sets that always returns 0.  This is
 256    used by languages that haven't deal with alias sets yet.  */
 257
 258 HOST_WIDE_INT
 259 hook_get_alias_set_0 (tree t ATTRIBUTE_UNUSED)
 260 {
 261   return 0;
 262 }
 263
 264 /* This is the default expand_expr function.  */
 265
 266 rtx
 267 lhd_expand_expr (tree t ATTRIBUTE_UNUSED, rtx r ATTRIBUTE_UNUSED,
 268                  enum machine_mode mm ATTRIBUTE_UNUSED,
 269                  int em ATTRIBUTE_UNUSED)
 270 {
 271   abort ();
 272 }
 273
 274 /* This is the default decl_printable_name function.  */
 275
 276 const char *
 277 lhd_decl_printable_name (tree decl, int verbosity ATTRIBUTE_UNUSED)
 278 {
 279   return IDENTIFIER_POINTER (DECL_NAME (decl));
 280 }
 281
 282 /* lang_hooks.tree_inlining.walk_subtrees is called by walk_tree()
 283    after handling common cases, but before walking code-specific
 284    sub-trees.  If this hook is overridden for a language, it should
 285    handle language-specific tree codes, as well as language-specific
 286    information associated to common tree codes.  If a tree node is
 287    completely handled within this function, it should set *SUBTREES to
 288    0, so that generic handling isn't attempted.  For language-specific
 289    tree codes, generic handling would abort(), so make sure it is set
 290    properly.  Both SUBTREES and *SUBTREES is guaranteed to be nonzero
 291    when the function is called.  */
 292
 293 tree
 294 lhd_tree_inlining_walk_subtrees (tree *tp ATTRIBUTE_UNUSED,
 295                                  int *subtrees ATTRIBUTE_UNUSED,
 296                                  walk_tree_fn func ATTRIBUTE_UNUSED,
 297                                  void *data ATTRIBUTE_UNUSED,
 298                                  void *htab ATTRIBUTE_UNUSED)
 299 {
 300   return NULL_TREE;
 301 }
 302
 303 /* lang_hooks.tree_inlining.cannot_inline_tree_fn is called to
 304    determine whether there are language-specific reasons for not
 305    inlining a given function.  */
 306
 307 int
 308 lhd_tree_inlining_cannot_inline_tree_fn (tree *fnp)
 309 {
 310   if (flag_really_no_inline
 311       && lookup_attribute ("always_inline", DECL_ATTRIBUTES (*fnp)) == NULL)
 312     return 1;
 313
 314   return 0;
 315 }
 316
 317 /* lang_hooks.tree_inlining.disregard_inline_limits is called to
 318    determine whether a function should be considered for inlining even
 319    if it would exceed inlining limits.  */
 320
 321 int
 322 lhd_tree_inlining_disregard_inline_limits (tree fn)
 323 {
 324   if (lookup_attribute ("always_inline", DECL_ATTRIBUTES (fn)) != NULL)
 325     return 1;
 326
 327   return 0;
 328 }
 329
 330 /* lang_hooks.tree_inlining.add_pending_fn_decls is called before
 331    starting to inline a function, to push any language-specific
 332    functions that should not be inlined into the current function,
 333    into VAFNP.  PFN is the top of varray, and should be returned if no
 334    functions are pushed into VAFNP.  The top of the varray should be
 335    returned.  */
 336
 337 tree
 338 lhd_tree_inlining_add_pending_fn_decls (void *vafnp ATTRIBUTE_UNUSED, tree pfn)
 339 {
 340   return pfn;
 341 }
 342
 343 /* lang_hooks.tree_inlining.tree_chain_matters_p indicates whether the
 344    TREE_CHAIN of a language-specific tree node is relevant, i.e.,
 345    whether it should be walked, copied and preserved across copies.  */
 346
 347 int
 348 lhd_tree_inlining_tree_chain_matters_p (tree t ATTRIBUTE_UNUSED)
 349 {
 350   return 0;
 351 }
 352
 353 /* lang_hooks.tree_inlining.auto_var_in_fn_p is called to determine
 354    whether VT is an automatic variable defined in function FT.  */
 355
 356 int
 357 lhd_tree_inlining_auto_var_in_fn_p (tree var, tree fn)
 358 {
 359   return (DECL_P (var) && DECL_CONTEXT (var) == fn
 360           && (((TREE_CODE (var) == VAR_DECL || TREE_CODE (var) == PARM_DECL)
 361                && ! TREE_STATIC (var))
 362               || TREE_CODE (var) == LABEL_DECL
 363               || TREE_CODE (var) == RESULT_DECL));
 364 }
 365
 366 /* lang_hooks.tree_inlining.copy_res_decl_for_inlining should return a
 367    declaration for the result RES of function FN to be inlined into
 368    CALLER.  NDP points to an integer that should be set in case a new
 369    declaration wasn't created (presumably because RES was of aggregate
 370    type, such that a TARGET_EXPR is used for the result).  TEXPS is a
 371    pointer to a varray with the stack of TARGET_EXPRs seen while
 372    inlining functions into caller; the top of TEXPS is supposed to
 373    match RES.  */
 374
 375 tree
 376 lhd_tree_inlining_copy_res_decl_for_inlining (tree res, tree fn, tree caller,
 377                                               void *dm ATTRIBUTE_UNUSED,
 378                                               int *ndp ATTRIBUTE_UNUSED,
 379                                               tree return_slot_addr ATTRIBUTE_UNUSED)
 380 {
 381   if (return_slot_addr)
 382     return build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (return_slot_addr)),
 383                    return_slot_addr);
 384   else
 385     return copy_decl_for_inlining (res, fn, caller);
 386 }
 387
 388 /* lang_hooks.tree_inlining.anon_aggr_type_p determines whether T is a
 389    type node representing an anonymous aggregate (union, struct, etc),
 390    i.e., one whose members are in the same scope as the union itself.  */
 391
 392 int
 393 lhd_tree_inlining_anon_aggr_type_p (tree t ATTRIBUTE_UNUSED)
 394 {
 395   return 0;
 396 }
 397
 398 /* lang_hooks.tree_inlining.start_inlining and end_inlining perform any
 399    language-specific bookkeeping necessary for processing
 400    FN. start_inlining returns nonzero if inlining should proceed, zero if
 401    not.
 402
 403    For instance, the C++ version keeps track of template instantiations to
 404    avoid infinite recursion.  */
 405
 406 int
 407 lhd_tree_inlining_start_inlining (tree fn ATTRIBUTE_UNUSED)
 408 {
 409   return 1;
 410 }
 411
 412 void
 413 lhd_tree_inlining_end_inlining (tree fn ATTRIBUTE_UNUSED)
 414 {
 415 }
 416
 417 /* lang_hooks.tree_inlining.convert_parm_for_inlining performs any
 418    language-specific conversion before assigning VALUE to PARM.  */
 419
 420 tree
 421 lhd_tree_inlining_convert_parm_for_inlining (tree parm ATTRIBUTE_UNUSED,
 422                                              tree value,
 423                                              tree fndecl ATTRIBUTE_UNUSED)
 424 {
 425   return value;
 426 }
 427
 428 /* lang_hooks.tree_dump.dump_tree:  Dump language-specific parts of tree
 429    nodes.  Returns nonzero if it does not want the usual dumping of the
 430    second argument.  */
 431
 432 bool
 433 lhd_tree_dump_dump_tree (void *di ATTRIBUTE_UNUSED, tree t ATTRIBUTE_UNUSED)
 434 {
 435   return false;
 436 }
 437
 438 /* lang_hooks.tree_dump.type_qual:  Determine type qualifiers in a
 439    language-specific way.  */
 440
 441 int
 442 lhd_tree_dump_type_quals (tree t)
 443 {
 444   return TYPE_QUALS (t);
 445 }
 446
 447 /* lang_hooks.expr_size: Determine the size of the value of an expression T
 448    in a language-specific way.  Returns a tree for the size in bytes.  */
 449
 450 tree
 451 lhd_expr_size (tree exp)
 452 {
 453   if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
 454       && DECL_SIZE_UNIT (exp) != 0)
 455     return DECL_SIZE_UNIT (exp);
 456   else
 457     return size_in_bytes (TREE_TYPE (exp));
 458 }
 459 /* lang_hooks.decl_uninit: Find out if a variable is uninitialized based
 460    on DECL_INITIAL.  */
 461
 462 bool
 463 lhd_decl_uninit (tree t ATTRIBUTE_UNUSED)
 464 {
 465   return false;
 466 }
 467
 468 /* lang_hooks.tree_size: Determine the size of a tree with code C,
 469    which is a language-specific tree code in category 'x'.  The
 470    default expects never to be called.  */
 471 size_t
 472 lhd_tree_size (enum tree_code c ATTRIBUTE_UNUSED)
 473 {
 474   abort ();
 475   return 0;
 476 }
 477
 478 /* Return true if decl, which is a function decl, may be called by a
 479    sibcall.  */
 480
 481 bool
 482 lhd_decl_ok_for_sibcall (tree decl ATTRIBUTE_UNUSED)
 483 {
 484   return true;
 485 }
 486
 487 /* lang_hooks.decls.final_write_globals: perform final processing on
 488    global variables.  */
 489 void
 490 write_global_declarations (void)
 491 {
 492   /* Really define vars that have had only a tentative definition.
 493      Really output inline functions that must actually be callable
 494      and have not been output so far.  */
 495
 496   tree globals = (*lang_hooks.decls.getdecls) ();
 497   int len = list_length (globals);
 498   tree *vec = xmalloc (sizeof (tree) * len);
 499   int i;
 500   tree decl;
 501
 502   /* Process the decls in reverse order--earliest first.
 503      Put them into VEC from back to front, then take out from front.  */
 504
 505   for (i = 0, decl = globals; i < len; i++, decl = TREE_CHAIN (decl))
 506     vec[len - i - 1] = decl;
 507
 508   wrapup_global_declarations (vec, len);
 509
 510   check_global_declarations (vec, len);
 511
 512     /* Clean up.  */
 513   free (vec);
 514 }
 515
 516 /* Called to perform language-specific initialization of CTX.  */
 517 void
 518 lhd_initialize_diagnostics (struct diagnostic_context *ctx ATTRIBUTE_UNUSED)
 519 {
 520 }
 521
 522 /* The default function to print out name of current function that caused
 523    an error.  */
 524 void
 525 lhd_print_error_function (diagnostic_context *context, const char *file)
 526 {
 527   if (diagnostic_last_function_changed (context))
 528     {
 529       const char *old_prefix = context->printer->prefix;
 530       char *new_prefix = file ? file_name_as_prefix (file) : NULL;
 531
 532       pp_set_prefix (context->printer, new_prefix);
 533
 534       if (current_function_decl == NULL)
 535         pp_printf (context->printer, "At top level:");
 536       else
 537         {
 538           if (TREE_CODE (TREE_TYPE (current_function_decl)) == METHOD_TYPE)
 539             pp_printf
 540               (context->printer, "In member function `%s':",
 541                (*lang_hooks.decl_printable_name) (current_function_decl, 2));
 542           else
 543             pp_printf
 544               (context->printer, "In function `%s':",
 545                (*lang_hooks.decl_printable_name) (current_function_decl, 2));
 546         }
 547       pp_newline (context->printer);
 548
 549       diagnostic_set_last_function (context);
 550       pp_flush (context->printer);
 551       context->printer->prefix = old_prefix;
 552       free ((char*) new_prefix);
 553     }
 554 }
 555
 556 tree
 557 lhd_callgraph_analyze_expr (tree *tp ATTRIBUTE_UNUSED,
 558                             int *walk_subtrees ATTRIBUTE_UNUSED,
 559                             tree decl ATTRIBUTE_UNUSED)
 560 {
 561   return NULL;
 562 }
 563
 564 #include "gt-langhooks.h"