gcc/langhooks.c

   1 /* Default language-specific hooks.
   2    Copyright 2001, 2002 Free Software Foundation, Inc.
   3    Contributed by Alexandre Oliva  <aoliva@redhat.com>
   4
   5 This file is part of GNU CC.
   6
   7 GNU CC 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 GNU CC 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 GNU CC; 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 "toplev.h"
  25 #include "tree.h"
  26 #include "c-tree.h"
  27 #include "tree-inline.h"
  28 #include "rtl.h"
  29 #include "insn-config.h"
  30 #include "integrate.h"
  31 #include "flags.h"
  32 #include "langhooks.h"
  33 #include "langhooks-def.h"
  34
  35 /* Do nothing; in many cases the default hook.  */
  36
  37 void
  38 lhd_do_nothing ()
  39 {
  40 }
  41
  42 /* Do nothing (tree).  */
  43
  44 void
  45 lhd_do_nothing_t (t)
  46      tree t ATTRIBUTE_UNUSED;
  47 {
  48 }
  49
  50 /* Do nothing (function).  */
  51
  52 void
  53 lhd_do_nothing_f (f)
  54      struct function *f ATTRIBUTE_UNUSED;
  55 {
  56 }
  57
  58 /* Do nothing (return the tree node passed).  */
  59
  60 tree
  61 lhd_return_tree (t)
  62      tree t;
  63 {
  64   return t;
  65 }
  66
  67 /* Do nothing (return NULL_TREE).  */
  68
  69 tree
  70 lhd_return_null_tree (t)
  71      tree t ATTRIBUTE_UNUSED;
  72 {
  73   return NULL_TREE;
  74 }
  75
  76 /* Do nothing; the default hook to decode an option.  */
  77
  78 int
  79 lhd_decode_option (argc, argv)
  80      int argc ATTRIBUTE_UNUSED;
  81      char **argv ATTRIBUTE_UNUSED;
  82 {
  83   return 0;
  84 }
  85
  86 /* Called from by print-tree.c.  */
  87
  88 void
  89 lhd_print_tree_nothing (file, node, indent)
  90      FILE *file ATTRIBUTE_UNUSED;
  91      tree node ATTRIBUTE_UNUSED;
  92      int indent ATTRIBUTE_UNUSED;
  93 {
  94 }
  95
  96 /* Called from safe_from_p.  */
  97
  98 int
  99 lhd_safe_from_p (x, exp)
 100      rtx x ATTRIBUTE_UNUSED;
 101      tree exp ATTRIBUTE_UNUSED;
 102 {
 103   return 1;
 104 }
 105
 106 /* Called from unsafe_for_reeval.  */
 107
 108 int
 109 lhd_unsafe_for_reeval (t)
 110      tree t ATTRIBUTE_UNUSED;
 111 {
 112   return -1;
 113 }
 114
 115 /* Called from staticp.  */
 116
 117 int
 118 lhd_staticp (exp)
 119      tree exp ATTRIBUTE_UNUSED;
 120 {
 121   return 0;
 122 }
 123
 124 /* Called from check_global_declarations.  */
 125
 126 bool
 127 lhd_warn_unused_global_decl (decl)
 128      tree decl;
 129 {
 130   /* This is what used to exist in check_global_declarations.  Probably
 131      not many of these actually apply to non-C languages.  */
 132
 133   if (TREE_CODE (decl) == FUNCTION_DECL && DECL_INLINE (decl))
 134     return false;
 135   if (TREE_CODE (decl) == VAR_DECL && TREE_READONLY (decl))
 136     return false;
 137   if (DECL_IN_SYSTEM_HEADER (decl))
 138     return false;
 139
 140   return true;
 141 }
 142
 143 /* Called when -dy is given on the command line.  */
 144
 145 void
 146 lhd_set_yydebug (value)
 147      int value;
 148 {
 149   if (value)
 150     fprintf (stderr, "warning: no yacc/bison-generated output to debug!\n");
 151 }
 152
 153 /* Set the DECL_ASSEMBLER_NAME for DECL.  */
 154 void
 155 lhd_set_decl_assembler_name (decl)
 156      tree decl;
 157 {
 158   /* The language-independent code should never use the
 159      DECL_ASSEMBLER_NAME for lots of DECLs.  Only FUNCTION_DECLs and
 160      VAR_DECLs for variables with static storage duration need a real
 161      DECL_ASSEMBLER_NAME.  */
 162   if (TREE_CODE (decl) == FUNCTION_DECL
 163       || (TREE_CODE (decl) == VAR_DECL
 164           && (TREE_STATIC (decl)
 165               || DECL_EXTERNAL (decl)
 166               || TREE_PUBLIC (decl))))
 167     /* By default, assume the name to use in assembly code is the
 168        same as that used in the source language.  (That's correct
 169        for C, and GCC used to set DECL_ASSEMBLER_NAME to the same
 170        value as DECL_NAME in build_decl, so this choice provides
 171        backwards compatibility with existing front-ends.  */
 172     SET_DECL_ASSEMBLER_NAME (decl, DECL_NAME (decl));
 173   else
 174     /* Nobody should ever be asking for the DECL_ASSEMBLER_NAME of
 175        these DECLs -- unless they're in language-dependent code, in
 176        which case set_decl_assembler_name hook should handle things.  */
 177     abort ();
 178 }
 179
 180 /* Provide a default routine to clear the binding stack.  This is used
 181    by languages that don't need to do anything special.  */
 182 void
 183 lhd_clear_binding_stack ()
 184 {
 185   while (! (*lang_hooks.decls.global_bindings_p) ())
 186     poplevel (0, 0, 0);
 187 }
 188
 189 /* Type promotion for variable arguments.  */
 190 tree
 191 lhd_type_promotes_to (type)
 192      tree type ATTRIBUTE_UNUSED;
 193 {
 194   abort ();
 195 }
 196
 197 /* Invalid use of an incomplete type.  */
 198 void
 199 lhd_incomplete_type_error (value, type)
 200      tree value ATTRIBUTE_UNUSED, type;
 201 {
 202   if (TREE_CODE (type) == ERROR_MARK)
 203     return;
 204
 205   abort ();
 206 }
 207
 208 /* Provide a default routine for alias sets that always returns -1.  This
 209    is used by languages that don't need to do anything special.  */
 210
 211 HOST_WIDE_INT
 212 lhd_get_alias_set (t)
 213      tree t ATTRIBUTE_UNUSED;
 214 {
 215   return -1;
 216 }
 217
 218 /* Provide a hook routine for alias sets that always returns 0.  This is
 219    used by languages that haven't deal with alias sets yet.  */
 220
 221 HOST_WIDE_INT
 222 hook_get_alias_set_0 (t)
 223      tree t ATTRIBUTE_UNUSED;
 224 {
 225   return 0;
 226 }
 227
 228 /* This is the default expand_expr function.  */
 229
 230 rtx
 231 lhd_expand_expr (t, r, mm, em)
 232      tree t ATTRIBUTE_UNUSED;
 233      rtx r ATTRIBUTE_UNUSED;
 234      enum machine_mode mm ATTRIBUTE_UNUSED;
 235      int em ATTRIBUTE_UNUSED;
 236 {
 237   abort ();
 238 }
 239
 240 /* This is the default decl_printable_name function.  */
 241
 242 const char *
 243 lhd_decl_printable_name (decl, verbosity)
 244      tree decl;
 245      int verbosity ATTRIBUTE_UNUSED;
 246 {
 247   return IDENTIFIER_POINTER (DECL_NAME (decl));
 248 }
 249
 250 /* lang_hooks.tree_inlining.walk_subtrees is called by walk_tree()
 251    after handling common cases, but before walking code-specific
 252    sub-trees.  If this hook is overridden for a language, it should
 253    handle language-specific tree codes, as well as language-specific
 254    information associated to common tree codes.  If a tree node is
 255    completely handled within this function, it should set *SUBTREES to
 256    0, so that generic handling isn't attempted.  For language-specific
 257    tree codes, generic handling would abort(), so make sure it is set
 258    properly.  Both SUBTREES and *SUBTREES is guaranteed to be non-zero
 259    when the function is called.  */
 260
 261 tree
 262 lhd_tree_inlining_walk_subtrees (tp,subtrees,func,data,htab)
 263      tree *tp ATTRIBUTE_UNUSED;
 264      int *subtrees ATTRIBUTE_UNUSED;
 265      walk_tree_fn func ATTRIBUTE_UNUSED;
 266      void *data ATTRIBUTE_UNUSED;
 267      void *htab ATTRIBUTE_UNUSED;
 268 {
 269   return NULL_TREE;
 270 }
 271
 272 /* lang_hooks.tree_inlining.cannot_inline_tree_fn is called to
 273    determine whether there are language-specific reasons for not
 274    inlining a given function.  */
 275
 276 int
 277 lhd_tree_inlining_cannot_inline_tree_fn (fnp)
 278      tree *fnp;
 279 {
 280   if (flag_really_no_inline
 281       && lookup_attribute ("always_inline", DECL_ATTRIBUTES (*fnp)) == NULL)
 282     return 1;
 283
 284   return 0;
 285 }
 286
 287 /* lang_hooks.tree_inlining.disregard_inline_limits is called to
 288    determine whether a function should be considered for inlining even
 289    if it would exceed inlining limits.  */
 290
 291 int
 292 lhd_tree_inlining_disregard_inline_limits (fn)
 293      tree fn;
 294 {
 295   if (lookup_attribute ("always_inline", DECL_ATTRIBUTES (fn)) != NULL)
 296     return 1;
 297
 298   return 0;
 299 }
 300
 301 /* lang_hooks.tree_inlining.add_pending_fn_decls is called before
 302    starting to inline a function, to push any language-specific
 303    functions that should not be inlined into the current function,
 304    into VAFNP.  PFN is the top of varray, and should be returned if no
 305    functions are pushed into VAFNP.  The top of the varray should be
 306    returned.  */
 307
 308 tree
 309 lhd_tree_inlining_add_pending_fn_decls (vafnp, pfn)
 310      void *vafnp ATTRIBUTE_UNUSED;
 311      tree pfn;
 312 {
 313   return pfn;
 314 }
 315
 316 /* lang_hooks.tree_inlining.tree_chain_matters_p indicates whether the
 317    TREE_CHAIN of a language-specific tree node is relevant, i.e.,
 318    whether it should be walked, copied and preserved across copies.  */
 319
 320 int
 321 lhd_tree_inlining_tree_chain_matters_p (t)
 322      tree t ATTRIBUTE_UNUSED;
 323 {
 324   return 0;
 325 }
 326
 327 /* lang_hooks.tree_inlining.auto_var_in_fn_p is called to determine
 328    whether VT is an automatic variable defined in function FT.  */
 329
 330 int
 331 lhd_tree_inlining_auto_var_in_fn_p (var, fn)
 332      tree var, fn;
 333 {
 334   return (DECL_P (var) && DECL_CONTEXT (var) == fn
 335           && (((TREE_CODE (var) == VAR_DECL || TREE_CODE (var) == PARM_DECL)
 336                && ! TREE_STATIC (var))
 337               || TREE_CODE (var) == LABEL_DECL
 338               || TREE_CODE (var) == RESULT_DECL));
 339 }
 340
 341 /* lang_hooks.tree_inlining.copy_res_decl_for_inlining should return a
 342    declaration for the result RES of function FN to be inlined into
 343    CALLER.  NDP points to an integer that should be set in case a new
 344    declaration wasn't created (presumably because RES was of aggregate
 345    type, such that a TARGET_EXPR is used for the result).  TEXPS is a
 346    pointer to a varray with the stack of TARGET_EXPRs seen while
 347    inlining functions into caller; the top of TEXPS is supposed to
 348    match RES.  */
 349
 350 tree
 351 lhd_tree_inlining_copy_res_decl_for_inlining (res, fn, caller,
 352                                               dm, ndp, texps)
 353      tree res, fn, caller;
 354      void *dm ATTRIBUTE_UNUSED;
 355      int *ndp ATTRIBUTE_UNUSED;
 356      void *texps ATTRIBUTE_UNUSED;
 357 {
 358   return copy_decl_for_inlining (res, fn, caller);
 359 }
 360
 361 /* lang_hooks.tree_inlining.anon_aggr_type_p determines whether T is a
 362    type node representing an anonymous aggregate (union, struct, etc),
 363    i.e., one whose members are in the same scope as the union itself.  */
 364
 365 int
 366 lhd_tree_inlining_anon_aggr_type_p (t)
 367      tree t ATTRIBUTE_UNUSED;
 368 {
 369   return 0;
 370 }
 371
 372 /* lang_hooks.tree_inlining.start_inlining and end_inlining perform any
 373    language-specific bookkeeping necessary for processing
 374    FN. start_inlining returns non-zero if inlining should proceed, zero if
 375    not.
 376
 377    For instance, the C++ version keeps track of template instantiations to
 378    avoid infinite recursion.  */
 379
 380 int
 381 lhd_tree_inlining_start_inlining (fn)
 382      tree fn ATTRIBUTE_UNUSED;
 383 {
 384   return 1;
 385 }
 386
 387 void
 388 lhd_tree_inlining_end_inlining (fn)
 389      tree fn ATTRIBUTE_UNUSED;
 390 {
 391 }
 392
 393 /* lang_hooks.tree_inlining.convert_parm_for_inlining performs any
 394    language-specific conversion before assigning VALUE to PARM.  */
 395
 396 tree
 397 lhd_tree_inlining_convert_parm_for_inlining (parm, value, fndecl)
 398      tree parm ATTRIBUTE_UNUSED;
 399      tree value;
 400      tree fndecl ATTRIBUTE_UNUSED;
 401 {
 402   return value;
 403 }
 404
 405 /* lang_hooks.tree_dump.dump_tree:  Dump language-specific parts of tree
 406    nodes.  Returns non-zero if it does not want the usual dumping of the
 407    second argument.  */
 408
 409 int
 410 lhd_tree_dump_dump_tree (di, t)
 411      void *di ATTRIBUTE_UNUSED;
 412      tree t ATTRIBUTE_UNUSED;
 413 {
 414   return 0;
 415 }
 416
 417 /* lang_hooks.tree_dump.type_qual:  Determine type qualifiers in a
 418    language-specific way.  */
 419
 420 int
 421 lhd_tree_dump_type_quals (t)
 422      tree t;
 423 {
 424   return TYPE_QUALS (t);
 425 }
 426