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