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;
 157 {
 158   if (optimize == 0
 159       && lookup_attribute ("always_inline", DECL_ATTRIBUTES (*fnp)) == NULL)
 160     return 1;
 161
 162   return 0;
 163 }
 164
 165 /* lang_hooks.tree_inlining.disregard_inline_limits is called to
 166    determine whether a function should be considered for inlining even
 167    if it would exceed inlining limits.  */
 168
 169 int
 170 lhd_tree_inlining_disregard_inline_limits (fn)
 171      tree fn;
 172 {
 173   if (lookup_attribute ("always_inline", DECL_ATTRIBUTES (fn)) != NULL)
 174     return 1;
 175
 176   return 0;
 177 }
 178
 179 /* lang_hooks.tree_inlining.add_pending_fn_decls is called before
 180    starting to inline a function, to push any language-specific
 181    functions that should not be inlined into the current function,
 182    into VAFNP.  PFN is the top of varray, and should be returned if no
 183    functions are pushed into VAFNP.  The top of the varray should be
 184    returned.  */
 185
 186 tree
 187 lhd_tree_inlining_add_pending_fn_decls (vafnp, pfn)
 188      void *vafnp ATTRIBUTE_UNUSED;
 189      tree pfn;
 190 {
 191   return pfn;
 192 }
 193
 194 /* lang_hooks.tree_inlining.tree_chain_matters_p indicates whether the
 195    TREE_CHAIN of a language-specific tree node is relevant, i.e.,
 196    whether it should be walked, copied and preserved across copies.  */
 197
 198 int
 199 lhd_tree_inlining_tree_chain_matters_p (t)
 200      tree t ATTRIBUTE_UNUSED;
 201 {
 202   return 0;
 203 }
 204
 205 /* lang_hooks.tree_inlining.auto_var_in_fn_p is called to determine
 206    whether VT is an automatic variable defined in function FT.  */
 207
 208 int
 209 lhd_tree_inlining_auto_var_in_fn_p (var, fn)
 210      tree var, fn;
 211 {
 212   return (DECL_P (var) && DECL_CONTEXT (var) == fn
 213           && (((TREE_CODE (var) == VAR_DECL || TREE_CODE (var) == PARM_DECL)
 214                && ! TREE_STATIC (var))
 215               || TREE_CODE (var) == LABEL_DECL
 216               || TREE_CODE (var) == RESULT_DECL));
 217 }
 218
 219 /* lang_hooks.tree_inlining.copy_res_decl_for_inlining should return a
 220    declaration for the result RES of function FN to be inlined into
 221    CALLER.  NDP points to an integer that should be set in case a new
 222    declaration wasn't created (presumably because RES was of aggregate
 223    type, such that a TARGET_EXPR is used for the result).  TEXPS is a
 224    pointer to a varray with the stack of TARGET_EXPRs seen while
 225    inlining functions into caller; the top of TEXPS is supposed to
 226    match RES.  */
 227
 228 tree
 229 lhd_tree_inlining_copy_res_decl_for_inlining (res, fn, caller,
 230                                               dm, ndp, texps)
 231      tree res, fn, caller;
 232      void *dm ATTRIBUTE_UNUSED;
 233      int *ndp ATTRIBUTE_UNUSED;
 234      void *texps ATTRIBUTE_UNUSED;
 235 {
 236   return copy_decl_for_inlining (res, fn, caller);
 237 }
 238
 239 /* lang_hooks.tree_inlining.anon_aggr_type_p determines whether T is a
 240    type node representing an anonymous aggregate (union, struct, etc),
 241    i.e., one whose members are in the same scope as the union itself.  */
 242
 243 int
 244 lhd_tree_inlining_anon_aggr_type_p (t)
 245      tree t ATTRIBUTE_UNUSED;
 246 {
 247   return 0;
 248 }
 249
 250 /* lang_hooks.tree_inlining.start_inlining and end_inlining perform any
 251    language-specific bookkeeping necessary for processing
 252    FN. start_inlining returns non-zero if inlining should proceed, zero if
 253    not.
 254
 255    For instance, the C++ version keeps track of template instantiations to
 256    avoid infinite recursion.  */
 257
 258 int
 259 lhd_tree_inlining_start_inlining (fn)
 260      tree fn ATTRIBUTE_UNUSED;
 261 {
 262   return 1;
 263 }
 264
 265 void
 266 lhd_tree_inlining_end_inlining (fn)
 267      tree fn ATTRIBUTE_UNUSED;
 268 {
 269 }
 270
 271 /* lang_hooks.tree_dump.dump_tree:  Dump language-specific parts of tree
 272    nodes.  Returns non-zero if it does not want the usual dumping of the
 273    second argument.  */
 274
 275 int
 276 lhd_tree_dump_dump_tree (di, t)
 277      void *di ATTRIBUTE_UNUSED;
 278      tree t ATTRIBUTE_UNUSED;
 279 {
 280   return 0;
 281 }
 282
 283 /* lang_hooks.tree_dump.type_qual:  Determine type qualifiers in a
 284    language-specific way.  */
 285
 286 int
 287 lhd_tree_dump_type_quals (t)
 288      tree t;
 289 {
 290   return TYPE_QUALS (t);
 291 }
 292