gcc/langhooks.c

   1 /* Default language-specific hooks.
   2    Copyright 2001 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 (return the tree node passed).  */
  43
  44 tree
  45 lhd_return_tree (t)
  46      tree t;
  47 {
  48   return t;
  49 }
  50
  51 /* Do nothing; the default hook to decode an option.  */
  52
  53 int
  54 lhd_decode_option (argc, argv)
  55      int argc ATTRIBUTE_UNUSED;
  56      char **argv ATTRIBUTE_UNUSED;
  57 {
  58   return 0;
  59 }
  60
  61 /* Called from by print-tree.c.  */
  62
  63 void
  64 lhd_print_tree_nothing (file, node, indent)
  65      FILE *file ATTRIBUTE_UNUSED;
  66      tree node ATTRIBUTE_UNUSED;
  67      int indent ATTRIBUTE_UNUSED;
  68 {
  69 }
  70
  71 /* Called from safe_from_p.  */
  72
  73 int
  74 lhd_safe_from_p (x, exp)
  75      rtx x ATTRIBUTE_UNUSED;
  76      tree exp ATTRIBUTE_UNUSED;
  77 {
  78   return 1;
  79 }
  80
  81 /* Called from staticp.  */
  82
  83 int
  84 lhd_staticp (exp)
  85      tree exp ATTRIBUTE_UNUSED;
  86 {
  87   return 0;
  88 }
  89
  90 /* Called when -dy is given on the command line.  */
  91
  92 void
  93 lhd_set_yydebug (value)
  94      int value;
  95 {
  96   if (value)
  97     fprintf (stderr, "warning: no yacc/bison-generated output to debug!\n");
  98 }
  99
 100 /* Provide a default routine to clear the binding stack.  This is used
 101    by languages that don't need to do anything special.  */
 102 void
 103 lhd_clear_binding_stack ()
 104 {
 105   while (! global_bindings_p ())
 106     poplevel (0, 0, 0);
 107 }
 108
 109 /* Provide a default routine for alias sets that always returns -1.  This
 110    is used by languages that don't need to do anything special.  */
 111
 112 HOST_WIDE_INT
 113 lhd_get_alias_set (t)
 114      tree t ATTRIBUTE_UNUSED;
 115 {
 116   return -1;
 117 }
 118
 119 /* Provide a hook routine for alias sets that always returns 0.  This is
 120    used by languages that haven't deal with alias sets yet.  */
 121
 122 HOST_WIDE_INT
 123 hook_get_alias_set_0 (t)
 124      tree t ATTRIBUTE_UNUSED;
 125 {
 126   return 0;
 127 }
 128
 129 /* lang_hooks.tree_inlining.walk_subtrees is called by walk_tree()
 130    after handling common cases, but before walking code-specific
 131    sub-trees.  If this hook is overridden for a language, it should
 132    handle language-specific tree codes, as well as language-specific
 133    information associated to common tree codes.  If a tree node is
 134    completely handled within this function, it should set *SUBTREES to
 135    0, so that generic handling isn't attempted.  For language-specific
 136    tree codes, generic handling would abort(), so make sure it is set
 137    properly.  Both SUBTREES and *SUBTREES is guaranteed to be non-zero
 138    when the function is called.  */
 139
 140 tree
 141 lhd_tree_inlining_walk_subtrees (tp,subtrees,func,data,htab)
 142      tree *tp ATTRIBUTE_UNUSED;
 143      int *subtrees ATTRIBUTE_UNUSED;
 144      walk_tree_fn func ATTRIBUTE_UNUSED;
 145      void *data ATTRIBUTE_UNUSED;
 146      void *htab ATTRIBUTE_UNUSED;
 147 {
 148   return NULL_TREE;
 149 }
 150
 151 /* lang_hooks.tree_inlining.cannot_inline_tree_fn is called to
 152    determine whether there are language-specific reasons for not
 153    inlining a given function.  */
 154
 155 int
 156 lhd_tree_inlining_cannot_inline_tree_fn (fnp)
 157      tree *fnp;
 158 {
 159   if (flag_really_no_inline
 160       && lookup_attribute ("always_inline", DECL_ATTRIBUTES (*fnp)) == NULL)
 161     return 1;
 162
 163   return 0;
 164 }
 165
 166 /* lang_hooks.tree_inlining.disregard_inline_limits is called to
 167    determine whether a function should be considered for inlining even
 168    if it would exceed inlining limits.  */
 169
 170 int
 171 lhd_tree_inlining_disregard_inline_limits (fn)
 172      tree fn;
 173 {
 174   if (lookup_attribute ("always_inline", DECL_ATTRIBUTES (fn)) != NULL)
 175     return 1;
 176
 177   return 0;
 178 }
 179
 180 /* lang_hooks.tree_inlining.add_pending_fn_decls is called before
 181    starting to inline a function, to push any language-specific
 182    functions that should not be inlined into the current function,
 183    into VAFNP.  PFN is the top of varray, and should be returned if no
 184    functions are pushed into VAFNP.  The top of the varray should be
 185    returned.  */
 186
 187 tree
 188 lhd_tree_inlining_add_pending_fn_decls (vafnp, pfn)
 189      void *vafnp ATTRIBUTE_UNUSED;
 190      tree pfn;
 191 {
 192   return pfn;
 193 }
 194
 195 /* lang_hooks.tree_inlining.tree_chain_matters_p indicates whether the
 196    TREE_CHAIN of a language-specific tree node is relevant, i.e.,
 197    whether it should be walked, copied and preserved across copies.  */
 198
 199 int
 200 lhd_tree_inlining_tree_chain_matters_p (t)
 201      tree t ATTRIBUTE_UNUSED;
 202 {
 203   return 0;
 204 }
 205
 206 /* lang_hooks.tree_inlining.auto_var_in_fn_p is called to determine
 207    whether VT is an automatic variable defined in function FT.  */
 208
 209 int
 210 lhd_tree_inlining_auto_var_in_fn_p (var, fn)
 211      tree var, fn;
 212 {
 213   return (DECL_P (var) && DECL_CONTEXT (var) == fn
 214           && (((TREE_CODE (var) == VAR_DECL || TREE_CODE (var) == PARM_DECL)
 215                && ! TREE_STATIC (var))
 216               || TREE_CODE (var) == LABEL_DECL
 217               || TREE_CODE (var) == RESULT_DECL));
 218 }
 219
 220 /* lang_hooks.tree_inlining.copy_res_decl_for_inlining should return a
 221    declaration for the result RES of function FN to be inlined into
 222    CALLER.  NDP points to an integer that should be set in case a new
 223    declaration wasn't created (presumably because RES was of aggregate
 224    type, such that a TARGET_EXPR is used for the result).  TEXPS is a
 225    pointer to a varray with the stack of TARGET_EXPRs seen while
 226    inlining functions into caller; the top of TEXPS is supposed to
 227    match RES.  */
 228
 229 tree
 230 lhd_tree_inlining_copy_res_decl_for_inlining (res, fn, caller,
 231                                               dm, ndp, texps)
 232      tree res, fn, caller;
 233      void *dm ATTRIBUTE_UNUSED;
 234      int *ndp ATTRIBUTE_UNUSED;
 235      void *texps ATTRIBUTE_UNUSED;
 236 {
 237   return copy_decl_for_inlining (res, fn, caller);
 238 }
 239
 240 /* lang_hooks.tree_inlining.anon_aggr_type_p determines whether T is a
 241    type node representing an anonymous aggregate (union, struct, etc),
 242    i.e., one whose members are in the same scope as the union itself.  */
 243
 244 int
 245 lhd_tree_inlining_anon_aggr_type_p (t)
 246      tree t ATTRIBUTE_UNUSED;
 247 {
 248   return 0;
 249 }
 250
 251 /* lang_hooks.tree_inlining.start_inlining and end_inlining perform any
 252    language-specific bookkeeping necessary for processing
 253    FN. start_inlining returns non-zero if inlining should proceed, zero if
 254    not.
 255
 256    For instance, the C++ version keeps track of template instantiations to
 257    avoid infinite recursion.  */
 258
 259 int
 260 lhd_tree_inlining_start_inlining (fn)
 261      tree fn ATTRIBUTE_UNUSED;
 262 {
 263   return 1;
 264 }
 265
 266 void
 267 lhd_tree_inlining_end_inlining (fn)
 268      tree fn ATTRIBUTE_UNUSED;
 269 {
 270 }
 271
 272 /* lang_hooks.tree_inlining.convert_parm_for_inlining performs any
 273    language-specific conversion before assigning VALUE to PARM.  */
 274
 275 tree
 276 lhd_tree_inlining_convert_parm_for_inlining (parm, value, fndecl)
 277      tree parm ATTRIBUTE_UNUSED;
 278      tree value;
 279      tree fndecl ATTRIBUTE_UNUSED;
 280 {
 281   return value;
 282 }
 283
 284 /* lang_hooks.tree_dump.dump_tree:  Dump language-specific parts of tree
 285    nodes.  Returns non-zero if it does not want the usual dumping of the
 286    second argument.  */
 287
 288 int
 289 lhd_tree_dump_dump_tree (di, t)
 290      void *di ATTRIBUTE_UNUSED;
 291      tree t ATTRIBUTE_UNUSED;
 292 {
 293   return 0;
 294 }
 295
 296 /* lang_hooks.tree_dump.type_qual:  Determine type qualifiers in a
 297    language-specific way.  */
 298
 299 int
 300 lhd_tree_dump_type_quals (t)
 301      tree t;
 302 {
 303   return TYPE_QUALS (t);
 304 }
 305