sourcebuild.texi: Add libcpp, now that CPP has its own directory.
[official-gcc.git] / gcc / langhooks.c
blobaa8dc3a633ac56d584014d24e1c04573bccba301
1 /* Default language-specific hooks.
2 Copyright 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
3 Contributed by Alexandre Oliva <aoliva@redhat.com>
5 This file is part of GCC.
7 GCC 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.
12 GCC 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.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
22 #include "config.h"
23 #include "system.h"
24 #include "coretypes.h"
25 #include "tm.h"
26 #include "toplev.h"
27 #include "tree.h"
28 #include "tree-inline.h"
29 #include "tree-gimple.h"
30 #include "rtl.h"
31 #include "insn-config.h"
32 #include "integrate.h"
33 #include "flags.h"
34 #include "langhooks.h"
35 #include "langhooks-def.h"
36 #include "ggc.h"
37 #include "diagnostic.h"
39 /* Do nothing; in many cases the default hook. */
41 void
42 lhd_do_nothing (void)
46 /* Do nothing (tree). */
48 void
49 lhd_do_nothing_t (tree t ATTRIBUTE_UNUSED)
53 /* Do nothing (int). */
55 void
56 lhd_do_nothing_i (int i ATTRIBUTE_UNUSED)
60 /* Do nothing (int, int, int). Return NULL_TREE. */
62 tree
63 lhd_do_nothing_iii_return_null_tree (int i ATTRIBUTE_UNUSED,
64 int j ATTRIBUTE_UNUSED,
65 int k ATTRIBUTE_UNUSED)
67 return NULL_TREE;
70 /* Do nothing (function). */
72 void
73 lhd_do_nothing_f (struct function *f ATTRIBUTE_UNUSED)
77 /* Do nothing (return the tree node passed). */
79 tree
80 lhd_return_tree (tree t)
82 return t;
85 /* Do nothing (return NULL_TREE). */
87 tree
88 lhd_return_null_tree_v (void)
90 return NULL_TREE;
93 /* Do nothing (return NULL_TREE). */
95 tree
96 lhd_return_null_tree (tree t ATTRIBUTE_UNUSED)
98 return NULL_TREE;
101 /* The default post options hook. */
103 bool
104 lhd_post_options (const char **pfilename ATTRIBUTE_UNUSED)
106 return false;
109 /* Called from by print-tree.c. */
111 void
112 lhd_print_tree_nothing (FILE *file ATTRIBUTE_UNUSED,
113 tree node ATTRIBUTE_UNUSED,
114 int indent ATTRIBUTE_UNUSED)
118 /* Called from safe_from_p. */
121 lhd_safe_from_p (rtx x ATTRIBUTE_UNUSED, tree exp ATTRIBUTE_UNUSED)
123 return 1;
126 /* Called from unsafe_for_reeval. */
129 lhd_unsafe_for_reeval (tree t ATTRIBUTE_UNUSED)
131 return -1;
134 /* Called from staticp. */
137 lhd_staticp (tree exp ATTRIBUTE_UNUSED)
139 return 0;
142 /* Called from check_global_declarations. */
144 bool
145 lhd_warn_unused_global_decl (tree decl)
147 /* This is what used to exist in check_global_declarations. Probably
148 not many of these actually apply to non-C languages. */
150 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_INLINE (decl))
151 return false;
152 if (TREE_CODE (decl) == VAR_DECL && TREE_READONLY (decl))
153 return false;
154 if (DECL_IN_SYSTEM_HEADER (decl))
155 return false;
157 return true;
160 /* Set the DECL_ASSEMBLER_NAME for DECL. */
161 void
162 lhd_set_decl_assembler_name (tree decl)
164 /* The language-independent code should never use the
165 DECL_ASSEMBLER_NAME for lots of DECLs. Only FUNCTION_DECLs and
166 VAR_DECLs for variables with static storage duration need a real
167 DECL_ASSEMBLER_NAME. */
168 if (TREE_CODE (decl) == FUNCTION_DECL
169 || (TREE_CODE (decl) == VAR_DECL
170 && (TREE_STATIC (decl)
171 || DECL_EXTERNAL (decl)
172 || TREE_PUBLIC (decl))))
174 /* By default, assume the name to use in assembly code is the
175 same as that used in the source language. (That's correct
176 for C, and GCC used to set DECL_ASSEMBLER_NAME to the same
177 value as DECL_NAME in build_decl, so this choice provides
178 backwards compatibility with existing front-ends.
180 Can't use just the variable's own name for a variable whose
181 scope is less than the whole compilation. Concatenate a
182 distinguishing number - we use the DECL_UID. */
183 if (TREE_PUBLIC (decl) || DECL_CONTEXT (decl) == NULL_TREE)
184 SET_DECL_ASSEMBLER_NAME (decl, DECL_NAME (decl));
185 else
187 const char *name = IDENTIFIER_POINTER (DECL_NAME (decl));
188 char *label;
190 ASM_FORMAT_PRIVATE_NAME (label, name, DECL_UID (decl));
191 SET_DECL_ASSEMBLER_NAME (decl, get_identifier (label));
194 else
195 /* Nobody should ever be asking for the DECL_ASSEMBLER_NAME of
196 these DECLs -- unless they're in language-dependent code, in
197 which case set_decl_assembler_name hook should handle things. */
198 abort ();
201 /* By default we always allow bit-field based optimizations. */
202 bool
203 lhd_can_use_bit_fields_p (void)
205 return true;
208 /* Type promotion for variable arguments. */
209 tree
210 lhd_type_promotes_to (tree type ATTRIBUTE_UNUSED)
212 abort ();
215 /* Registration of machine- or os-specific builtin types. */
216 void
217 lhd_register_builtin_type (tree type ATTRIBUTE_UNUSED,
218 const char* name ATTRIBUTE_UNUSED)
222 /* Invalid use of an incomplete type. */
223 void
224 lhd_incomplete_type_error (tree value ATTRIBUTE_UNUSED, tree type)
226 if (TREE_CODE (type) == ERROR_MARK)
227 return;
229 abort ();
232 /* Provide a default routine for alias sets that always returns -1. This
233 is used by languages that don't need to do anything special. */
235 HOST_WIDE_INT
236 lhd_get_alias_set (tree t ATTRIBUTE_UNUSED)
238 return -1;
241 /* Provide a hook routine for alias sets that always returns 0. This is
242 used by languages that haven't deal with alias sets yet. */
244 HOST_WIDE_INT
245 hook_get_alias_set_0 (tree t ATTRIBUTE_UNUSED)
247 return 0;
250 /* This is the default expand_expr function. */
253 lhd_expand_expr (tree t ATTRIBUTE_UNUSED, rtx r ATTRIBUTE_UNUSED,
254 enum machine_mode mm ATTRIBUTE_UNUSED,
255 int em ATTRIBUTE_UNUSED,
256 rtx *a ATTRIBUTE_UNUSED)
258 abort ();
261 /* The default language-specific function for expanding a decl. After
262 the language-independent cases are handled, this function will be
263 called. If this function is not defined, it is assumed that
264 declarations other than those for variables and labels do not require
265 any RTL generation. */
268 lhd_expand_decl (tree t ATTRIBUTE_UNUSED)
270 return 0;
273 /* This is the default decl_printable_name function. */
275 const char *
276 lhd_decl_printable_name (tree decl, int verbosity ATTRIBUTE_UNUSED)
278 return IDENTIFIER_POINTER (DECL_NAME (decl));
281 /* This compares two types for equivalence ("compatible" in C-based languages).
282 This routine should only return 1 if it is sure. It should not be used
283 in contexts where erroneously returning 0 causes problems. */
286 lhd_types_compatible_p (tree x, tree y)
288 return TYPE_MAIN_VARIANT (x) == TYPE_MAIN_VARIANT (y);
291 /* lang_hooks.tree_inlining.walk_subtrees is called by walk_tree()
292 after handling common cases, but before walking code-specific
293 sub-trees. If this hook is overridden for a language, it should
294 handle language-specific tree codes, as well as language-specific
295 information associated to common tree codes. If a tree node is
296 completely handled within this function, it should set *SUBTREES to
297 0, so that generic handling isn't attempted. For language-specific
298 tree codes, generic handling would abort(), so make sure it is set
299 properly. Both SUBTREES and *SUBTREES is guaranteed to be nonzero
300 when the function is called. */
302 tree
303 lhd_tree_inlining_walk_subtrees (tree *tp ATTRIBUTE_UNUSED,
304 int *subtrees ATTRIBUTE_UNUSED,
305 walk_tree_fn func ATTRIBUTE_UNUSED,
306 void *data ATTRIBUTE_UNUSED,
307 void *htab ATTRIBUTE_UNUSED)
309 return NULL_TREE;
312 /* lang_hooks.tree_inlining.cannot_inline_tree_fn is called to
313 determine whether there are language-specific reasons for not
314 inlining a given function. */
317 lhd_tree_inlining_cannot_inline_tree_fn (tree *fnp)
319 if (flag_really_no_inline
320 && lookup_attribute ("always_inline", DECL_ATTRIBUTES (*fnp)) == NULL)
321 return 1;
323 return 0;
326 /* lang_hooks.tree_inlining.disregard_inline_limits is called to
327 determine whether a function should be considered for inlining even
328 if it would exceed inlining limits. */
331 lhd_tree_inlining_disregard_inline_limits (tree fn)
333 if (lookup_attribute ("always_inline", DECL_ATTRIBUTES (fn)) != NULL)
334 return 1;
336 return 0;
339 /* lang_hooks.tree_inlining.add_pending_fn_decls is called before
340 starting to inline a function, to push any language-specific
341 functions that should not be inlined into the current function,
342 into VAFNP. PFN is the top of varray, and should be returned if no
343 functions are pushed into VAFNP. The top of the varray should be
344 returned. */
346 tree
347 lhd_tree_inlining_add_pending_fn_decls (void *vafnp ATTRIBUTE_UNUSED, tree pfn)
349 return pfn;
352 /* lang_hooks.tree_inlining.auto_var_in_fn_p is called to determine
353 whether VT is an automatic variable defined in function FT. */
356 lhd_tree_inlining_auto_var_in_fn_p (tree var, tree fn)
358 return (DECL_P (var) && DECL_CONTEXT (var) == fn
359 && (((TREE_CODE (var) == VAR_DECL || TREE_CODE (var) == PARM_DECL)
360 && ! TREE_STATIC (var))
361 || TREE_CODE (var) == LABEL_DECL
362 || TREE_CODE (var) == RESULT_DECL));
365 /* lang_hooks.tree_inlining.anon_aggr_type_p determines whether T is a
366 type node representing an anonymous aggregate (union, struct, etc),
367 i.e., one whose members are in the same scope as the union itself. */
370 lhd_tree_inlining_anon_aggr_type_p (tree t ATTRIBUTE_UNUSED)
372 return 0;
375 /* lang_hooks.tree_inlining.start_inlining and end_inlining perform any
376 language-specific bookkeeping necessary for processing
377 FN. start_inlining returns nonzero if inlining should proceed, zero if
378 not.
380 For instance, the C++ version keeps track of template instantiations to
381 avoid infinite recursion. */
384 lhd_tree_inlining_start_inlining (tree fn ATTRIBUTE_UNUSED)
386 return 1;
389 void
390 lhd_tree_inlining_end_inlining (tree fn ATTRIBUTE_UNUSED)
394 /* lang_hooks.tree_inlining.convert_parm_for_inlining performs any
395 language-specific conversion before assigning VALUE to PARM. */
397 tree
398 lhd_tree_inlining_convert_parm_for_inlining (tree parm ATTRIBUTE_UNUSED,
399 tree value,
400 tree fndecl ATTRIBUTE_UNUSED,
401 int argnum ATTRIBUTE_UNUSED)
403 return value;
406 /* lang_hooks.tree_dump.dump_tree: Dump language-specific parts of tree
407 nodes. Returns nonzero if it does not want the usual dumping of the
408 second argument. */
410 bool
411 lhd_tree_dump_dump_tree (void *di ATTRIBUTE_UNUSED, tree t ATTRIBUTE_UNUSED)
413 return false;
416 /* lang_hooks.tree_dump.type_qual: Determine type qualifiers in a
417 language-specific way. */
420 lhd_tree_dump_type_quals (tree t)
422 return TYPE_QUALS (t);
425 /* lang_hooks.expr_size: Determine the size of the value of an expression T
426 in a language-specific way. Returns a tree for the size in bytes. */
428 tree
429 lhd_expr_size (tree exp)
431 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
432 && DECL_SIZE_UNIT (exp) != 0)
433 return DECL_SIZE_UNIT (exp);
434 else
435 return size_in_bytes (TREE_TYPE (exp));
438 /* lang_hooks.gimplify_expr re-writes *EXPR_P into GIMPLE form. */
441 lhd_gimplify_expr (tree *expr_p ATTRIBUTE_UNUSED, tree *pre_p ATTRIBUTE_UNUSED,
442 tree *post_p ATTRIBUTE_UNUSED)
444 return GS_UNHANDLED;
447 /* lang_hooks.tree_size: Determine the size of a tree with code C,
448 which is a language-specific tree code in category 'x'. The
449 default expects never to be called. */
450 size_t
451 lhd_tree_size (enum tree_code c ATTRIBUTE_UNUSED)
453 abort ();
454 return 0;
457 /* Return true if decl, which is a function decl, may be called by a
458 sibcall. */
460 bool
461 lhd_decl_ok_for_sibcall (tree decl ATTRIBUTE_UNUSED)
463 return true;
466 /* lang_hooks.decls.final_write_globals: perform final processing on
467 global variables. */
468 void
469 write_global_declarations (void)
471 /* Really define vars that have had only a tentative definition.
472 Really output inline functions that must actually be callable
473 and have not been output so far. */
475 tree globals = lang_hooks.decls.getdecls ();
476 int len = list_length (globals);
477 tree *vec = xmalloc (sizeof (tree) * len);
478 int i;
479 tree decl;
481 /* Process the decls in reverse order--earliest first.
482 Put them into VEC from back to front, then take out from front. */
484 for (i = 0, decl = globals; i < len; i++, decl = TREE_CHAIN (decl))
485 vec[len - i - 1] = decl;
487 wrapup_global_declarations (vec, len);
489 check_global_declarations (vec, len);
491 /* Clean up. */
492 free (vec);
495 /* Called to perform language-specific initialization of CTX. */
496 void
497 lhd_initialize_diagnostics (struct diagnostic_context *ctx ATTRIBUTE_UNUSED)
501 /* The default function to print out name of current function that caused
502 an error. */
503 void
504 lhd_print_error_function (diagnostic_context *context, const char *file)
506 if (diagnostic_last_function_changed (context))
508 const char *old_prefix = context->printer->prefix;
509 char *new_prefix = file ? file_name_as_prefix (file) : NULL;
511 pp_set_prefix (context->printer, new_prefix);
513 if (current_function_decl == NULL)
514 pp_printf (context->printer, "At top level:");
515 else
517 if (TREE_CODE (TREE_TYPE (current_function_decl)) == METHOD_TYPE)
518 pp_printf
519 (context->printer, "In member function `%s':",
520 lang_hooks.decl_printable_name (current_function_decl, 2));
521 else
522 pp_printf
523 (context->printer, "In function `%s':",
524 lang_hooks.decl_printable_name (current_function_decl, 2));
527 diagnostic_set_last_function (context);
528 pp_flush (context->printer);
529 context->printer->prefix = old_prefix;
530 free ((char*) new_prefix);
534 tree
535 lhd_callgraph_analyze_expr (tree *tp ATTRIBUTE_UNUSED,
536 int *walk_subtrees ATTRIBUTE_UNUSED,
537 tree decl ATTRIBUTE_UNUSED)
539 return NULL;
542 tree
543 lhd_make_node (enum tree_code code)
545 return make_node (code);