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