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;
  75      tree exp;
  76 {
  77   return 1;
  78 }
  79
  80 /* Called when -dy is given on the command line.  */
  81
  82 void
  83 lhd_set_yydebug (value)
  84      int value;
  85 {
  86   if (value)
  87     fprintf (stderr, "warning: no yacc/bison-generated output to debug!\n");
  88 }
  89
  90 /* Provide a default routine to clear the binding stack.  This is used
  91    by languages that don't need to do anything special.  */
  92 void
  93 lhd_clear_binding_stack ()
  94 {
  95   while (! global_bindings_p ())
  96     poplevel (0, 0, 0);
  97 }
  98
  99 /* Provide a default routine for alias sets that always returns -1.  This
 100    is used by languages that don't need to do anything special.  */
 101
 102 HOST_WIDE_INT
 103 lhd_get_alias_set (t)
 104      tree t ATTRIBUTE_UNUSED;
 105 {
 106   return -1;
 107 }
 108
 109 /* Provide a hook routine for alias sets that always returns 0.  This is
 110    used by languages that haven't deal with alias sets yet.  */
 111
 112 HOST_WIDE_INT
 113 hook_get_alias_set_0 (t)
 114      tree t ATTRIBUTE_UNUSED;
 115 {
 116   return 0;
 117 }
 118
 119 /* lang_hooks.tree_inlining.walk_subtrees is called by walk_tree()
 120    after handling common cases, but before walking code-specific
 121    sub-trees.  If this hook is overridden for a language, it should
 122    handle language-specific tree codes, as well as language-specific
 123    information associated to common tree codes.  If a tree node is
 124    completely handled within this function, it should set *SUBTREES to
 125    0, so that generic handling isn't attempted.  For language-specific
 126    tree codes, generic handling would abort(), so make sure it is set
 127    properly.  Both SUBTREES and *SUBTREES is guaranteed to be non-zero
 128    when the function is called.  */
 129
 130 tree
 131 lhd_tree_inlining_walk_subtrees (tp,subtrees,func,data,htab)
 132      tree *tp ATTRIBUTE_UNUSED;
 133      int *subtrees ATTRIBUTE_UNUSED;
 134      walk_tree_fn func ATTRIBUTE_UNUSED;
 135      void *data ATTRIBUTE_UNUSED;
 136      void *htab ATTRIBUTE_UNUSED;
 137 {
 138   return NULL_TREE;
 139 }
 140
 141 /* lang_hooks.tree_inlining.cannot_inline_tree_fn is called to
 142    determine whether there are language-specific reasons for not
 143    inlining a given function.  */
 144
 145 int
 146 lhd_tree_inlining_cannot_inline_tree_fn (fnp)
 147      tree *fnp ATTRIBUTE_UNUSED;
 148 {
 149   return 0;
 150 }
 151
 152 /* lang_hooks.tree_inlining.disregard_inline_limits is called to
 153    determine whether a function should be considered for inlining even
 154    if it would exceed inlining limits.  */
 155
 156 int
 157 lhd_tree_inlining_disregard_inline_limits (fn)
 158      tree fn ATTRIBUTE_UNUSED;
 159 {
 160   return 0;
 161 }
 162
 163 /* lang_hooks.tree_inlining.add_pending_fn_decls is called before
 164    starting to inline a function, to push any language-specific
 165    functions that should not be inlined into the current function,
 166    into VAFNP.  PFN is the top of varray, and should be returned if no
 167    functions are pushed into VAFNP.  The top of the varray should be
 168    returned.  */
 169
 170 tree
 171 lhd_tree_inlining_add_pending_fn_decls (vafnp, pfn)
 172      void *vafnp ATTRIBUTE_UNUSED;
 173      tree pfn;
 174 {
 175   return pfn;
 176 }
 177
 178 /* lang_hooks.tree_inlining.tree_chain_matters_p indicates whether the
 179    TREE_CHAIN of a language-specific tree node is relevant, i.e.,
 180    whether it should be walked, copied and preserved across copies.  */
 181
 182 int
 183 lhd_tree_inlining_tree_chain_matters_p (t)
 184      tree t ATTRIBUTE_UNUSED;
 185 {
 186   return 0;
 187 }
 188
 189 /* lang_hooks.tree_inlining.auto_var_in_fn_p is called to determine
 190    whether VT is an automatic variable defined in function FT.  */
 191
 192 int
 193 lhd_tree_inlining_auto_var_in_fn_p (var, fn)
 194      tree var, fn;
 195 {
 196   return (DECL_P (var) && DECL_CONTEXT (var) == fn
 197           && (((TREE_CODE (var) == VAR_DECL || TREE_CODE (var) == PARM_DECL)
 198                && ! TREE_STATIC (var))
 199               || TREE_CODE (var) == LABEL_DECL
 200               || TREE_CODE (var) == RESULT_DECL));
 201 }
 202
 203 /* lang_hooks.tree_inlining.copy_res_decl_for_inlining should return a
 204    declaration for the result RES of function FN to be inlined into
 205    CALLER.  NDP points to an integer that should be set in case a new
 206    declaration wasn't created (presumably because RES was of aggregate
 207    type, such that a TARGET_EXPR is used for the result).  TEXPS is a
 208    pointer to a varray with the stack of TARGET_EXPRs seen while
 209    inlining functions into caller; the top of TEXPS is supposed to
 210    match RES.  */
 211
 212 tree
 213 lhd_tree_inlining_copy_res_decl_for_inlining (res, fn, caller,
 214                                               dm, ndp, texps)
 215      tree res, fn, caller;
 216      void *dm ATTRIBUTE_UNUSED;
 217      int *ndp ATTRIBUTE_UNUSED;
 218      void *texps ATTRIBUTE_UNUSED;
 219 {
 220   return copy_decl_for_inlining (res, fn, caller);
 221 }
 222
 223 /* lang_hooks.tree_inlining.anon_aggr_type_p determines whether T is a
 224    type node representing an anonymous aggregate (union, struct, etc),
 225    i.e., one whose members are in the same scope as the union itself.  */
 226
 227 int
 228 lhd_tree_inlining_anon_aggr_type_p (t)
 229      tree t ATTRIBUTE_UNUSED;
 230 {
 231   return 0;
 232 }
 233
 234 /* lang_hooks.tree_dump.dump_tree:  Dump language-specific parts of tree
 235    nodes.  Returns non-zero if it does not want the usual dumping of the
 236    second argument.  */
 237
 238 int
 239 lhd_tree_dump_dump_tree (di, t)
 240      void *di ATTRIBUTE_UNUSED;
 241      tree t ATTRIBUTE_UNUSED;
 242 {
 243   return 0;
 244 }
 245
 246 /* lang_hooks.tree_dump.type_qual:  Determine type qualifiers in a
 247    language-specific way.  */
 248
 249 int
 250 lhd_tree_dump_type_quals (t)
 251      tree t;
 252 {
 253   return TYPE_QUALS (t);
 254 }
 255