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 staticp.  */
  99
 100 int
 101 lhd_staticp (exp)
 102      tree exp ATTRIBUTE_UNUSED;
 103 {
 104   return 0;
 105 }
 106
 107 /* Called when -dy is given on the command line.  */
 108
 109 void
 110 lhd_set_yydebug (value)
 111      int value;
 112 {
 113   if (value)
 114     fprintf (stderr, "warning: no yacc/bison-generated output to debug!\n");
 115 }
 116
 117 /* Provide a default routine to clear the binding stack.  This is used
 118    by languages that don't need to do anything special.  */
 119 void
 120 lhd_clear_binding_stack ()
 121 {
 122   while (! (*lang_hooks.decls.global_bindings_p) ())
 123     poplevel (0, 0, 0);
 124 }
 125
 126 /* Provide a default routine for alias sets that always returns -1.  This
 127    is used by languages that don't need to do anything special.  */
 128
 129 HOST_WIDE_INT
 130 lhd_get_alias_set (t)
 131      tree t ATTRIBUTE_UNUSED;
 132 {
 133   return -1;
 134 }
 135
 136 /* Provide a hook routine for alias sets that always returns 0.  This is
 137    used by languages that haven't deal with alias sets yet.  */
 138
 139 HOST_WIDE_INT
 140 hook_get_alias_set_0 (t)
 141      tree t ATTRIBUTE_UNUSED;
 142 {
 143   return 0;
 144 }
 145
 146 /* This is the default expand_expr function.  */
 147
 148 rtx
 149 lhd_expand_expr (t, r, mm, em)
 150      tree t ATTRIBUTE_UNUSED;
 151      rtx r ATTRIBUTE_UNUSED;
 152      enum machine_mode mm ATTRIBUTE_UNUSED;
 153      int em ATTRIBUTE_UNUSED;
 154 {
 155   abort ();
 156 }
 157
 158 /* This is the default decl_printable_name function.  */
 159
 160 const char *
 161 lhd_decl_printable_name (decl, verbosity)
 162      tree decl;
 163      int verbosity ATTRIBUTE_UNUSED;
 164 {
 165   return IDENTIFIER_POINTER (DECL_NAME (decl));
 166 }
 167
 168 /* lang_hooks.tree_inlining.walk_subtrees is called by walk_tree()
 169    after handling common cases, but before walking code-specific
 170    sub-trees.  If this hook is overridden for a language, it should
 171    handle language-specific tree codes, as well as language-specific
 172    information associated to common tree codes.  If a tree node is
 173    completely handled within this function, it should set *SUBTREES to
 174    0, so that generic handling isn't attempted.  For language-specific
 175    tree codes, generic handling would abort(), so make sure it is set
 176    properly.  Both SUBTREES and *SUBTREES is guaranteed to be non-zero
 177    when the function is called.  */
 178
 179 tree
 180 lhd_tree_inlining_walk_subtrees (tp,subtrees,func,data,htab)
 181      tree *tp ATTRIBUTE_UNUSED;
 182      int *subtrees ATTRIBUTE_UNUSED;
 183      walk_tree_fn func ATTRIBUTE_UNUSED;
 184      void *data ATTRIBUTE_UNUSED;
 185      void *htab ATTRIBUTE_UNUSED;
 186 {
 187   return NULL_TREE;
 188 }
 189
 190 /* lang_hooks.tree_inlining.cannot_inline_tree_fn is called to
 191    determine whether there are language-specific reasons for not
 192    inlining a given function.  */
 193
 194 int
 195 lhd_tree_inlining_cannot_inline_tree_fn (fnp)
 196      tree *fnp;
 197 {
 198   if (flag_really_no_inline
 199       && lookup_attribute ("always_inline", DECL_ATTRIBUTES (*fnp)) == NULL)
 200     return 1;
 201
 202   return 0;
 203 }
 204
 205 /* lang_hooks.tree_inlining.disregard_inline_limits is called to
 206    determine whether a function should be considered for inlining even
 207    if it would exceed inlining limits.  */
 208
 209 int
 210 lhd_tree_inlining_disregard_inline_limits (fn)
 211      tree fn;
 212 {
 213   if (lookup_attribute ("always_inline", DECL_ATTRIBUTES (fn)) != NULL)
 214     return 1;
 215
 216   return 0;
 217 }
 218
 219 /* lang_hooks.tree_inlining.add_pending_fn_decls is called before
 220    starting to inline a function, to push any language-specific
 221    functions that should not be inlined into the current function,
 222    into VAFNP.  PFN is the top of varray, and should be returned if no
 223    functions are pushed into VAFNP.  The top of the varray should be
 224    returned.  */
 225
 226 tree
 227 lhd_tree_inlining_add_pending_fn_decls (vafnp, pfn)
 228      void *vafnp ATTRIBUTE_UNUSED;
 229      tree pfn;
 230 {
 231   return pfn;
 232 }
 233
 234 /* lang_hooks.tree_inlining.tree_chain_matters_p indicates whether the
 235    TREE_CHAIN of a language-specific tree node is relevant, i.e.,
 236    whether it should be walked, copied and preserved across copies.  */
 237
 238 int
 239 lhd_tree_inlining_tree_chain_matters_p (t)
 240      tree t ATTRIBUTE_UNUSED;
 241 {
 242   return 0;
 243 }
 244
 245 /* lang_hooks.tree_inlining.auto_var_in_fn_p is called to determine
 246    whether VT is an automatic variable defined in function FT.  */
 247
 248 int
 249 lhd_tree_inlining_auto_var_in_fn_p (var, fn)
 250      tree var, fn;
 251 {
 252   return (DECL_P (var) && DECL_CONTEXT (var) == fn
 253           && (((TREE_CODE (var) == VAR_DECL || TREE_CODE (var) == PARM_DECL)
 254                && ! TREE_STATIC (var))
 255               || TREE_CODE (var) == LABEL_DECL
 256               || TREE_CODE (var) == RESULT_DECL));
 257 }
 258
 259 /* lang_hooks.tree_inlining.copy_res_decl_for_inlining should return a
 260    declaration for the result RES of function FN to be inlined into
 261    CALLER.  NDP points to an integer that should be set in case a new
 262    declaration wasn't created (presumably because RES was of aggregate
 263    type, such that a TARGET_EXPR is used for the result).  TEXPS is a
 264    pointer to a varray with the stack of TARGET_EXPRs seen while
 265    inlining functions into caller; the top of TEXPS is supposed to
 266    match RES.  */
 267
 268 tree
 269 lhd_tree_inlining_copy_res_decl_for_inlining (res, fn, caller,
 270                                               dm, ndp, texps)
 271      tree res, fn, caller;
 272      void *dm ATTRIBUTE_UNUSED;
 273      int *ndp ATTRIBUTE_UNUSED;
 274      void *texps ATTRIBUTE_UNUSED;
 275 {
 276   return copy_decl_for_inlining (res, fn, caller);
 277 }
 278
 279 /* lang_hooks.tree_inlining.anon_aggr_type_p determines whether T is a
 280    type node representing an anonymous aggregate (union, struct, etc),
 281    i.e., one whose members are in the same scope as the union itself.  */
 282
 283 int
 284 lhd_tree_inlining_anon_aggr_type_p (t)
 285      tree t ATTRIBUTE_UNUSED;
 286 {
 287   return 0;
 288 }
 289
 290 /* lang_hooks.tree_inlining.start_inlining and end_inlining perform any
 291    language-specific bookkeeping necessary for processing
 292    FN. start_inlining returns non-zero if inlining should proceed, zero if
 293    not.
 294
 295    For instance, the C++ version keeps track of template instantiations to
 296    avoid infinite recursion.  */
 297
 298 int
 299 lhd_tree_inlining_start_inlining (fn)
 300      tree fn ATTRIBUTE_UNUSED;
 301 {
 302   return 1;
 303 }
 304
 305 void
 306 lhd_tree_inlining_end_inlining (fn)
 307      tree fn ATTRIBUTE_UNUSED;
 308 {
 309 }
 310
 311 /* lang_hooks.tree_inlining.convert_parm_for_inlining performs any
 312    language-specific conversion before assigning VALUE to PARM.  */
 313
 314 tree
 315 lhd_tree_inlining_convert_parm_for_inlining (parm, value, fndecl)
 316      tree parm ATTRIBUTE_UNUSED;
 317      tree value;
 318      tree fndecl ATTRIBUTE_UNUSED;
 319 {
 320   return value;
 321 }
 322
 323 /* lang_hooks.tree_dump.dump_tree:  Dump language-specific parts of tree
 324    nodes.  Returns non-zero if it does not want the usual dumping of the
 325    second argument.  */
 326
 327 int
 328 lhd_tree_dump_dump_tree (di, t)
 329      void *di ATTRIBUTE_UNUSED;
 330      tree t ATTRIBUTE_UNUSED;
 331 {
 332   return 0;
 333 }
 334
 335 /* lang_hooks.tree_dump.type_qual:  Determine type qualifiers in a
 336    language-specific way.  */
 337
 338 int
 339 lhd_tree_dump_type_quals (t)
 340      tree t;
 341 {
 342   return TYPE_QUALS (t);
 343 }
 344