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.  */
  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; the default hook to decode an option.  */
  60
  61 int
  62 lhd_decode_option (argc, argv)
  63      int argc ATTRIBUTE_UNUSED;
  64      char **argv ATTRIBUTE_UNUSED;
  65 {
  66   return 0;
  67 }
  68
  69 /* Called from by print-tree.c.  */
  70
  71 void
  72 lhd_print_tree_nothing (file, node, indent)
  73      FILE *file ATTRIBUTE_UNUSED;
  74      tree node ATTRIBUTE_UNUSED;
  75      int indent ATTRIBUTE_UNUSED;
  76 {
  77 }
  78
  79 /* Called from safe_from_p.  */
  80
  81 int
  82 lhd_safe_from_p (x, exp)
  83      rtx x ATTRIBUTE_UNUSED;
  84      tree exp ATTRIBUTE_UNUSED;
  85 {
  86   return 1;
  87 }
  88
  89 /* Called from staticp.  */
  90
  91 int
  92 lhd_staticp (exp)
  93      tree exp ATTRIBUTE_UNUSED;
  94 {
  95   return 0;
  96 }
  97
  98 /* Called when -dy is given on the command line.  */
  99
 100 void
 101 lhd_set_yydebug (value)
 102      int value;
 103 {
 104   if (value)
 105     fprintf (stderr, "warning: no yacc/bison-generated output to debug!\n");
 106 }
 107
 108 /* Provide a default routine to clear the binding stack.  This is used
 109    by languages that don't need to do anything special.  */
 110 void
 111 lhd_clear_binding_stack ()
 112 {
 113   while (! global_bindings_p ())
 114     poplevel (0, 0, 0);
 115 }
 116
 117 /* Provide a default routine for alias sets that always returns -1.  This
 118    is used by languages that don't need to do anything special.  */
 119
 120 HOST_WIDE_INT
 121 lhd_get_alias_set (t)
 122      tree t ATTRIBUTE_UNUSED;
 123 {
 124   return -1;
 125 }
 126
 127 /* Provide a hook routine for alias sets that always returns 0.  This is
 128    used by languages that haven't deal with alias sets yet.  */
 129
 130 HOST_WIDE_INT
 131 hook_get_alias_set_0 (t)
 132      tree t ATTRIBUTE_UNUSED;
 133 {
 134   return 0;
 135 }
 136
 137 /* lang_hooks.tree_inlining.walk_subtrees is called by walk_tree()
 138    after handling common cases, but before walking code-specific
 139    sub-trees.  If this hook is overridden for a language, it should
 140    handle language-specific tree codes, as well as language-specific
 141    information associated to common tree codes.  If a tree node is
 142    completely handled within this function, it should set *SUBTREES to
 143    0, so that generic handling isn't attempted.  For language-specific
 144    tree codes, generic handling would abort(), so make sure it is set
 145    properly.  Both SUBTREES and *SUBTREES is guaranteed to be non-zero
 146    when the function is called.  */
 147
 148 tree
 149 lhd_tree_inlining_walk_subtrees (tp,subtrees,func,data,htab)
 150      tree *tp ATTRIBUTE_UNUSED;
 151      int *subtrees ATTRIBUTE_UNUSED;
 152      walk_tree_fn func ATTRIBUTE_UNUSED;
 153      void *data ATTRIBUTE_UNUSED;
 154      void *htab ATTRIBUTE_UNUSED;
 155 {
 156   return NULL_TREE;
 157 }
 158
 159 /* lang_hooks.tree_inlining.cannot_inline_tree_fn is called to
 160    determine whether there are language-specific reasons for not
 161    inlining a given function.  */
 162
 163 int
 164 lhd_tree_inlining_cannot_inline_tree_fn (fnp)
 165      tree *fnp;
 166 {
 167   if (optimize == 0
 168       && lookup_attribute ("always_inline", DECL_ATTRIBUTES (*fnp)) == NULL)
 169     return 1;
 170
 171   return 0;
 172 }
 173
 174 /* lang_hooks.tree_inlining.disregard_inline_limits is called to
 175    determine whether a function should be considered for inlining even
 176    if it would exceed inlining limits.  */
 177
 178 int
 179 lhd_tree_inlining_disregard_inline_limits (fn)
 180      tree fn;
 181 {
 182   if (lookup_attribute ("always_inline", DECL_ATTRIBUTES (fn)) != NULL)
 183     return 1;
 184
 185   return 0;
 186 }
 187
 188 /* lang_hooks.tree_inlining.add_pending_fn_decls is called before
 189    starting to inline a function, to push any language-specific
 190    functions that should not be inlined into the current function,
 191    into VAFNP.  PFN is the top of varray, and should be returned if no
 192    functions are pushed into VAFNP.  The top of the varray should be
 193    returned.  */
 194
 195 tree
 196 lhd_tree_inlining_add_pending_fn_decls (vafnp, pfn)
 197      void *vafnp ATTRIBUTE_UNUSED;
 198      tree pfn;
 199 {
 200   return pfn;
 201 }
 202
 203 /* lang_hooks.tree_inlining.tree_chain_matters_p indicates whether the
 204    TREE_CHAIN of a language-specific tree node is relevant, i.e.,
 205    whether it should be walked, copied and preserved across copies.  */
 206
 207 int
 208 lhd_tree_inlining_tree_chain_matters_p (t)
 209      tree t ATTRIBUTE_UNUSED;
 210 {
 211   return 0;
 212 }
 213
 214 /* lang_hooks.tree_inlining.auto_var_in_fn_p is called to determine
 215    whether VT is an automatic variable defined in function FT.  */
 216
 217 int
 218 lhd_tree_inlining_auto_var_in_fn_p (var, fn)
 219      tree var, fn;
 220 {
 221   return (DECL_P (var) && DECL_CONTEXT (var) == fn
 222           && (((TREE_CODE (var) == VAR_DECL || TREE_CODE (var) == PARM_DECL)
 223                && ! TREE_STATIC (var))
 224               || TREE_CODE (var) == LABEL_DECL
 225               || TREE_CODE (var) == RESULT_DECL));
 226 }
 227
 228 /* lang_hooks.tree_inlining.copy_res_decl_for_inlining should return a
 229    declaration for the result RES of function FN to be inlined into
 230    CALLER.  NDP points to an integer that should be set in case a new
 231    declaration wasn't created (presumably because RES was of aggregate
 232    type, such that a TARGET_EXPR is used for the result).  TEXPS is a
 233    pointer to a varray with the stack of TARGET_EXPRs seen while
 234    inlining functions into caller; the top of TEXPS is supposed to
 235    match RES.  */
 236
 237 tree
 238 lhd_tree_inlining_copy_res_decl_for_inlining (res, fn, caller,
 239                                               dm, ndp, texps)
 240      tree res, fn, caller;
 241      void *dm ATTRIBUTE_UNUSED;
 242      int *ndp ATTRIBUTE_UNUSED;
 243      void *texps ATTRIBUTE_UNUSED;
 244 {
 245   return copy_decl_for_inlining (res, fn, caller);
 246 }
 247
 248 /* lang_hooks.tree_inlining.anon_aggr_type_p determines whether T is a
 249    type node representing an anonymous aggregate (union, struct, etc),
 250    i.e., one whose members are in the same scope as the union itself.  */
 251
 252 int
 253 lhd_tree_inlining_anon_aggr_type_p (t)
 254      tree t ATTRIBUTE_UNUSED;
 255 {
 256   return 0;
 257 }
 258
 259 /* lang_hooks.tree_inlining.start_inlining and end_inlining perform any
 260    language-specific bookkeeping necessary for processing
 261    FN. start_inlining returns non-zero if inlining should proceed, zero if
 262    not.
 263
 264    For instance, the C++ version keeps track of template instantiations to
 265    avoid infinite recursion.  */
 266
 267 int
 268 lhd_tree_inlining_start_inlining (fn)
 269      tree fn ATTRIBUTE_UNUSED;
 270 {
 271   return 1;
 272 }
 273
 274 void
 275 lhd_tree_inlining_end_inlining (fn)
 276      tree fn ATTRIBUTE_UNUSED;
 277 {
 278 }
 279
 280 /* lang_hooks.tree_dump.dump_tree:  Dump language-specific parts of tree
 281    nodes.  Returns non-zero if it does not want the usual dumping of the
 282    second argument.  */
 283
 284 int
 285 lhd_tree_dump_dump_tree (di, t)
 286      void *di ATTRIBUTE_UNUSED;
 287      tree t ATTRIBUTE_UNUSED;
 288 {
 289   return 0;
 290 }
 291
 292 /* lang_hooks.tree_dump.type_qual:  Determine type qualifiers in a
 293    language-specific way.  */
 294
 295 int
 296 lhd_tree_dump_type_quals (t)
 297      tree t;
 298 {
 299   return TYPE_QUALS (t);
 300 }
 301