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 "langhooks.h"
  32 #include "langhooks-def.h"
  33
  34 /* Do nothing; in many cases the default hook.  */
  35
  36 void
  37 lhd_do_nothing ()
  38 {
  39 }
  40
  41 /* Do nothing (return the tree node passed).  */
  42
  43 tree
  44 lhd_return_tree (t)
  45      tree t;
  46 {
  47   return t;
  48 }
  49
  50 /* Do nothing; the default hook to decode an option.  */
  51
  52 int
  53 lhd_decode_option (argc, argv)
  54      int argc ATTRIBUTE_UNUSED;
  55      char **argv ATTRIBUTE_UNUSED;
  56 {
  57   return 0;
  58 }
  59
  60 /* Called from by print-tree.c.  */
  61
  62 void
  63 lhd_print_tree_nothing (file, node, indent)
  64      FILE *file ATTRIBUTE_UNUSED;
  65      tree node ATTRIBUTE_UNUSED;
  66      int indent ATTRIBUTE_UNUSED;
  67 {
  68 }
  69
  70 /* Called from safe_from_p.  */
  71
  72 int
  73 lhd_safe_from_p (x, exp)
  74      rtx x ATTRIBUTE_UNUSED;
  75      tree exp ATTRIBUTE_UNUSED;
  76 {
  77   return 1;
  78 }
  79
  80 /* Called from staticp.  */
  81
  82 int
  83 lhd_staticp (exp)
  84      tree exp ATTRIBUTE_UNUSED;
  85 {
  86   return 0;
  87 }
  88
  89 /* Called when -dy is given on the command line.  */
  90
  91 void
  92 lhd_set_yydebug (value)
  93      int value;
  94 {
  95   if (value)
  96     fprintf (stderr, "warning: no yacc/bison-generated output to debug!\n");
  97 }
  98
  99 /* Provide a default routine to clear the binding stack.  This is used
 100    by languages that don't need to do anything special.  */
 101 void
 102 lhd_clear_binding_stack ()
 103 {
 104   while (! global_bindings_p ())
 105     poplevel (0, 0, 0);
 106 }
 107
 108 /* Provide a default routine for alias sets that always returns -1.  This
 109    is used by languages that don't need to do anything special.  */
 110
 111 HOST_WIDE_INT
 112 lhd_get_alias_set (t)
 113      tree t ATTRIBUTE_UNUSED;
 114 {
 115   return -1;
 116 }
 117
 118 /* Provide a hook routine for alias sets that always returns 0.  This is
 119    used by languages that haven't deal with alias sets yet.  */
 120
 121 HOST_WIDE_INT
 122 hook_get_alias_set_0 (t)
 123      tree t ATTRIBUTE_UNUSED;
 124 {
 125   return 0;
 126 }
 127
 128 /* lang_hooks.tree_inlining.walk_subtrees is called by walk_tree()
 129    after handling common cases, but before walking code-specific
 130    sub-trees.  If this hook is overridden for a language, it should
 131    handle language-specific tree codes, as well as language-specific
 132    information associated to common tree codes.  If a tree node is
 133    completely handled within this function, it should set *SUBTREES to
 134    0, so that generic handling isn't attempted.  For language-specific
 135    tree codes, generic handling would abort(), so make sure it is set
 136    properly.  Both SUBTREES and *SUBTREES is guaranteed to be non-zero
 137    when the function is called.  */
 138
 139 tree
 140 lhd_tree_inlining_walk_subtrees (tp,subtrees,func,data,htab)
 141      tree *tp ATTRIBUTE_UNUSED;
 142      int *subtrees ATTRIBUTE_UNUSED;
 143      walk_tree_fn func ATTRIBUTE_UNUSED;
 144      void *data ATTRIBUTE_UNUSED;
 145      void *htab ATTRIBUTE_UNUSED;
 146 {
 147   return NULL_TREE;
 148 }
 149
 150 /* lang_hooks.tree_inlining.cannot_inline_tree_fn is called to
 151    determine whether there are language-specific reasons for not
 152    inlining a given function.  */
 153
 154 int
 155 lhd_tree_inlining_cannot_inline_tree_fn (fnp)
 156      tree *fnp ATTRIBUTE_UNUSED;
 157 {
 158   return 0;
 159 }
 160
 161 /* lang_hooks.tree_inlining.disregard_inline_limits is called to
 162    determine whether a function should be considered for inlining even
 163    if it would exceed inlining limits.  */
 164
 165 int
 166 lhd_tree_inlining_disregard_inline_limits (fn)
 167      tree fn ATTRIBUTE_UNUSED;
 168 {
 169   return 0;
 170 }
 171
 172 /* lang_hooks.tree_inlining.add_pending_fn_decls is called before
 173    starting to inline a function, to push any language-specific
 174    functions that should not be inlined into the current function,
 175    into VAFNP.  PFN is the top of varray, and should be returned if no
 176    functions are pushed into VAFNP.  The top of the varray should be
 177    returned.  */
 178
 179 tree
 180 lhd_tree_inlining_add_pending_fn_decls (vafnp, pfn)
 181      void *vafnp ATTRIBUTE_UNUSED;
 182      tree pfn;
 183 {
 184   return pfn;
 185 }
 186
 187 /* lang_hooks.tree_inlining.tree_chain_matters_p indicates whether the
 188    TREE_CHAIN of a language-specific tree node is relevant, i.e.,
 189    whether it should be walked, copied and preserved across copies.  */
 190
 191 int
 192 lhd_tree_inlining_tree_chain_matters_p (t)
 193      tree t ATTRIBUTE_UNUSED;
 194 {
 195   return 0;
 196 }
 197
 198 /* lang_hooks.tree_inlining.auto_var_in_fn_p is called to determine
 199    whether VT is an automatic variable defined in function FT.  */
 200
 201 int
 202 lhd_tree_inlining_auto_var_in_fn_p (var, fn)
 203      tree var, fn;
 204 {
 205   return (DECL_P (var) && DECL_CONTEXT (var) == fn
 206           && (((TREE_CODE (var) == VAR_DECL || TREE_CODE (var) == PARM_DECL)
 207                && ! TREE_STATIC (var))
 208               || TREE_CODE (var) == LABEL_DECL
 209               || TREE_CODE (var) == RESULT_DECL));
 210 }
 211
 212 /* lang_hooks.tree_inlining.copy_res_decl_for_inlining should return a
 213    declaration for the result RES of function FN to be inlined into
 214    CALLER.  NDP points to an integer that should be set in case a new
 215    declaration wasn't created (presumably because RES was of aggregate
 216    type, such that a TARGET_EXPR is used for the result).  TEXPS is a
 217    pointer to a varray with the stack of TARGET_EXPRs seen while
 218    inlining functions into caller; the top of TEXPS is supposed to
 219    match RES.  */
 220
 221 tree
 222 lhd_tree_inlining_copy_res_decl_for_inlining (res, fn, caller,
 223                                               dm, ndp, texps)
 224      tree res, fn, caller;
 225      void *dm ATTRIBUTE_UNUSED;
 226      int *ndp ATTRIBUTE_UNUSED;
 227      void *texps ATTRIBUTE_UNUSED;
 228 {
 229   return copy_decl_for_inlining (res, fn, caller);
 230 }
 231
 232 /* lang_hooks.tree_inlining.anon_aggr_type_p determines whether T is a
 233    type node representing an anonymous aggregate (union, struct, etc),
 234    i.e., one whose members are in the same scope as the union itself.  */
 235
 236 int
 237 lhd_tree_inlining_anon_aggr_type_p (t)
 238      tree t ATTRIBUTE_UNUSED;
 239 {
 240   return 0;
 241 }
 242
 243 /* lang_hooks.tree_inlining.start_inlining and end_inlining perform any
 244    language-specific bookkeeping necessary for processing
 245    FN. start_inlining returns non-zero if inlining should proceed, zero if
 246    not.
 247
 248    For instance, the C++ version keeps track of template instantiations to
 249    avoid infinite recursion.  */
 250
 251 int
 252 lhd_tree_inlining_start_inlining (fn)
 253      tree fn ATTRIBUTE_UNUSED;
 254 {
 255   return 1;
 256 }
 257
 258 void
 259 lhd_tree_inlining_end_inlining (fn)
 260      tree fn ATTRIBUTE_UNUSED;
 261 {
 262 }
 263
 264 /* lang_hooks.tree_dump.dump_tree:  Dump language-specific parts of tree
 265    nodes.  Returns non-zero if it does not want the usual dumping of the
 266    second argument.  */
 267
 268 int
 269 lhd_tree_dump_dump_tree (di, t)
 270      void *di ATTRIBUTE_UNUSED;
 271      tree t ATTRIBUTE_UNUSED;
 272 {
 273   return 0;
 274 }
 275
 276 /* lang_hooks.tree_dump.type_qual:  Determine type qualifiers in a
 277    language-specific way.  */
 278
 279 int
 280 lhd_tree_dump_type_quals (t)
 281      tree t;
 282 {
 283   return TYPE_QUALS (t);
 284 }
 285