gcc/
[official-gcc.git] / gcc / langhooks.c
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1 /* Default language-specific hooks.
2 Copyright (C) 2001-2015 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 3, 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 COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
21 #include "config.h"
22 #include "system.h"
23 #include "coretypes.h"
24 #include "intl.h"
25 #include "tm.h"
26 #include "toplev.h"
27 #include "alias.h"
28 #include "symtab.h"
29 #include "tree.h"
30 #include "stringpool.h"
31 #include "attribs.h"
32 #include "tree-inline.h"
33 #include "gimplify.h"
34 #include "rtl.h"
35 #include "insn-config.h"
36 #include "flags.h"
37 #include "langhooks.h"
38 #include "target.h"
39 #include "langhooks-def.h"
40 #include "diagnostic.h"
41 #include "tree-diagnostic.h"
42 #include "hard-reg-set.h"
43 #include "function.h"
44 #include "cgraph.h"
45 #include "timevar.h"
46 #include "output.h"
48 /* Do nothing; in many cases the default hook. */
50 void
51 lhd_do_nothing (void)
55 /* Do nothing (tree). */
57 void
58 lhd_do_nothing_t (tree ARG_UNUSED (t))
62 /* Pass through (tree). */
63 tree
64 lhd_pass_through_t (tree t)
66 return t;
69 /* Do nothing (int, int, int). Return NULL_TREE. */
71 tree
72 lhd_do_nothing_iii_return_null_tree (int ARG_UNUSED (i),
73 int ARG_UNUSED (j),
74 int ARG_UNUSED (k))
76 return NULL_TREE;
79 /* Do nothing (function). */
81 void
82 lhd_do_nothing_f (struct function * ARG_UNUSED (f))
86 /* Do nothing (return NULL_TREE). */
88 tree
89 lhd_return_null_tree_v (void)
91 return NULL_TREE;
94 /* Do nothing (return NULL_TREE). */
96 tree
97 lhd_return_null_tree (tree ARG_UNUSED (t))
99 return NULL_TREE;
102 /* Do nothing (return NULL_TREE). */
104 tree
105 lhd_return_null_const_tree (const_tree ARG_UNUSED (t))
107 return NULL_TREE;
110 /* The default post options hook. */
112 bool
113 lhd_post_options (const char ** ARG_UNUSED (pfilename))
115 /* Excess precision other than "fast" requires front-end
116 support. */
117 flag_excess_precision_cmdline = EXCESS_PRECISION_FAST;
118 return false;
121 /* Called from by print-tree.c. */
123 void
124 lhd_print_tree_nothing (FILE * ARG_UNUSED (file),
125 tree ARG_UNUSED (node),
126 int ARG_UNUSED (indent))
130 /* Called from check_global_declaration. */
132 bool
133 lhd_warn_unused_global_decl (const_tree decl)
135 /* This is what used to exist in check_global_declaration. Probably
136 not many of these actually apply to non-C languages. */
138 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (decl))
139 return false;
140 if (TREE_CODE (decl) == VAR_DECL && TREE_READONLY (decl))
141 return false;
142 if (DECL_IN_SYSTEM_HEADER (decl))
143 return false;
145 return true;
148 /* Set the DECL_ASSEMBLER_NAME for DECL. */
149 void
150 lhd_set_decl_assembler_name (tree decl)
152 tree id;
154 /* set_decl_assembler_name may be called on TYPE_DECL to record ODR
155 name for C++ types. By default types have no ODR names. */
156 if (TREE_CODE (decl) == TYPE_DECL)
157 return;
159 /* The language-independent code should never use the
160 DECL_ASSEMBLER_NAME for lots of DECLs. Only FUNCTION_DECLs and
161 VAR_DECLs for variables with static storage duration need a real
162 DECL_ASSEMBLER_NAME. */
163 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
164 || (TREE_CODE (decl) == VAR_DECL
165 && (TREE_STATIC (decl)
166 || DECL_EXTERNAL (decl)
167 || TREE_PUBLIC (decl))));
169 /* By default, assume the name to use in assembly code is the same
170 as that used in the source language. (That's correct for C, and
171 GCC used to set DECL_ASSEMBLER_NAME to the same value as
172 DECL_NAME in build_decl, so this choice provides backwards
173 compatibility with existing front-ends. This assumption is wrapped
174 in a target hook, to allow for target-specific modification of the
175 identifier.
177 Can't use just the variable's own name for a variable whose scope
178 is less than the whole compilation. Concatenate a distinguishing
179 number - we use the DECL_UID. */
181 if (TREE_PUBLIC (decl) || DECL_FILE_SCOPE_P (decl))
182 id = targetm.mangle_decl_assembler_name (decl, DECL_NAME (decl));
183 else
185 const char *name = IDENTIFIER_POINTER (DECL_NAME (decl));
186 char *label;
188 ASM_FORMAT_PRIVATE_NAME (label, name, DECL_UID (decl));
189 id = get_identifier (label);
191 SET_DECL_ASSEMBLER_NAME (decl, id);
195 /* Type promotion for variable arguments. */
196 tree
197 lhd_type_promotes_to (tree ARG_UNUSED (type))
199 gcc_unreachable ();
202 /* Registration of machine- or os-specific builtin types. */
203 void
204 lhd_register_builtin_type (tree ARG_UNUSED (type),
205 const char * ARG_UNUSED (name))
209 /* Invalid use of an incomplete type. */
210 void
211 lhd_incomplete_type_error (const_tree ARG_UNUSED (value), const_tree type)
213 gcc_assert (TREE_CODE (type) == ERROR_MARK);
214 return;
217 /* Provide a default routine for alias sets that always returns -1. This
218 is used by languages that don't need to do anything special. */
220 alias_set_type
221 lhd_get_alias_set (tree ARG_UNUSED (t))
223 return -1;
226 /* This is the default decl_printable_name function. */
228 const char *
229 lhd_decl_printable_name (tree decl, int ARG_UNUSED (verbosity))
231 gcc_assert (decl && DECL_NAME (decl));
232 return IDENTIFIER_POINTER (DECL_NAME (decl));
235 /* This is the default dwarf_name function. */
237 const char *
238 lhd_dwarf_name (tree t, int verbosity)
240 gcc_assert (DECL_P (t));
242 return lang_hooks.decl_printable_name (t, verbosity);
245 /* This compares two types for equivalence ("compatible" in C-based languages).
246 This routine should only return 1 if it is sure. It should not be used
247 in contexts where erroneously returning 0 causes problems. */
250 lhd_types_compatible_p (tree x, tree y)
252 return TYPE_MAIN_VARIANT (x) == TYPE_MAIN_VARIANT (y);
255 /* lang_hooks.tree_dump.dump_tree: Dump language-specific parts of tree
256 nodes. Returns nonzero if it does not want the usual dumping of the
257 second argument. */
259 bool
260 lhd_tree_dump_dump_tree (void *di ATTRIBUTE_UNUSED, tree t ATTRIBUTE_UNUSED)
262 return false;
265 /* lang_hooks.tree_dump.type_qual: Determine type qualifiers in a
266 language-specific way. */
269 lhd_tree_dump_type_quals (const_tree t)
271 return TYPE_QUALS (t);
274 /* lang_hooks.gimplify_expr re-writes *EXPR_P into GIMPLE form. */
277 lhd_gimplify_expr (tree *expr_p ATTRIBUTE_UNUSED,
278 gimple_seq *pre_p ATTRIBUTE_UNUSED,
279 gimple_seq *post_p ATTRIBUTE_UNUSED)
281 return GS_UNHANDLED;
284 /* lang_hooks.tree_size: Determine the size of a tree with code C,
285 which is a language-specific tree code in category tcc_constant or
286 tcc_exceptional. The default expects never to be called. */
287 size_t
288 lhd_tree_size (enum tree_code c ATTRIBUTE_UNUSED)
290 gcc_unreachable ();
293 /* Return true if decl, which is a function decl, may be called by a
294 sibcall. */
296 bool
297 lhd_decl_ok_for_sibcall (const_tree decl ATTRIBUTE_UNUSED)
299 return true;
302 /* Generic global declaration processing. This is meant to be called
303 by the front-ends at the end of parsing. C/C++ do their own thing,
304 but other front-ends may call this. */
306 void
307 global_decl_processing (void)
309 tree globals, decl, *vec;
310 int len, i;
312 timevar_stop (TV_PHASE_PARSING);
313 timevar_start (TV_PHASE_DEFERRED);
314 /* Really define vars that have had only a tentative definition.
315 Really output inline functions that must actually be callable
316 and have not been output so far. */
318 globals = lang_hooks.decls.getdecls ();
319 len = list_length (globals);
320 vec = XNEWVEC (tree, len);
322 /* Process the decls in reverse order--earliest first.
323 Put them into VEC from back to front, then take out from front. */
325 for (i = 0, decl = globals; i < len; i++, decl = DECL_CHAIN (decl))
326 vec[len - i - 1] = decl;
328 wrapup_global_declarations (vec, len);
329 timevar_stop (TV_PHASE_DEFERRED);
331 timevar_start (TV_PHASE_PARSING);
332 free (vec);
335 /* Called to perform language-specific initialization of CTX. */
336 void
337 lhd_initialize_diagnostics (diagnostic_context *ctx ATTRIBUTE_UNUSED)
341 /* Called to perform language-specific options initialization. */
342 void
343 lhd_init_options (unsigned int decoded_options_count ATTRIBUTE_UNUSED,
344 struct cl_decoded_option *decoded_options ATTRIBUTE_UNUSED)
348 /* By default, always complain about options for the wrong language. */
349 bool
350 lhd_complain_wrong_lang_p (const struct cl_option *option ATTRIBUTE_UNUSED)
352 return true;
355 /* By default, no language-specific options are valid. */
356 bool
357 lhd_handle_option (size_t code ATTRIBUTE_UNUSED,
358 const char *arg ATTRIBUTE_UNUSED,
359 int value ATTRIBUTE_UNUSED, int kind ATTRIBUTE_UNUSED,
360 location_t loc ATTRIBUTE_UNUSED,
361 const struct cl_option_handlers *handlers ATTRIBUTE_UNUSED)
363 return false;
366 /* The default function to print out name of current function that caused
367 an error. */
368 void
369 lhd_print_error_function (diagnostic_context *context, const char *file,
370 diagnostic_info *diagnostic)
372 if (diagnostic_last_function_changed (context, diagnostic))
374 const char *old_prefix = context->printer->prefix;
375 tree abstract_origin = diagnostic_abstract_origin (diagnostic);
376 char *new_prefix = (file && abstract_origin == NULL)
377 ? file_name_as_prefix (context, file) : NULL;
379 pp_set_prefix (context->printer, new_prefix);
381 if (current_function_decl == NULL)
382 pp_printf (context->printer, _("At top level:"));
383 else
385 tree fndecl, ao;
387 if (abstract_origin)
389 ao = BLOCK_ABSTRACT_ORIGIN (abstract_origin);
390 while (TREE_CODE (ao) == BLOCK
391 && BLOCK_ABSTRACT_ORIGIN (ao)
392 && BLOCK_ABSTRACT_ORIGIN (ao) != ao)
393 ao = BLOCK_ABSTRACT_ORIGIN (ao);
394 gcc_assert (TREE_CODE (ao) == FUNCTION_DECL);
395 fndecl = ao;
397 else
398 fndecl = current_function_decl;
400 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
401 pp_printf
402 (context->printer, _("In member function %qs"),
403 identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
404 else
405 pp_printf
406 (context->printer, _("In function %qs"),
407 identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
409 while (abstract_origin)
411 location_t *locus;
412 tree block = abstract_origin;
414 locus = &BLOCK_SOURCE_LOCATION (block);
415 fndecl = NULL;
416 block = BLOCK_SUPERCONTEXT (block);
417 while (block && TREE_CODE (block) == BLOCK
418 && BLOCK_ABSTRACT_ORIGIN (block))
420 ao = BLOCK_ABSTRACT_ORIGIN (block);
422 while (TREE_CODE (ao) == BLOCK
423 && BLOCK_ABSTRACT_ORIGIN (ao)
424 && BLOCK_ABSTRACT_ORIGIN (ao) != ao)
425 ao = BLOCK_ABSTRACT_ORIGIN (ao);
427 if (TREE_CODE (ao) == FUNCTION_DECL)
429 fndecl = ao;
430 break;
432 else if (TREE_CODE (ao) != BLOCK)
433 break;
435 block = BLOCK_SUPERCONTEXT (block);
437 if (fndecl)
438 abstract_origin = block;
439 else
441 while (block && TREE_CODE (block) == BLOCK)
442 block = BLOCK_SUPERCONTEXT (block);
444 if (block && TREE_CODE (block) == FUNCTION_DECL)
445 fndecl = block;
446 abstract_origin = NULL;
448 if (fndecl)
450 expanded_location s = expand_location (*locus);
451 pp_comma (context->printer);
452 pp_newline (context->printer);
453 if (s.file != NULL)
455 if (context->show_column)
456 pp_printf (context->printer,
457 _(" inlined from %qs at %r%s:%d:%d%R"),
458 identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)),
459 "locus", s.file, s.line, s.column);
460 else
461 pp_printf (context->printer,
462 _(" inlined from %qs at %r%s:%d%R"),
463 identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)),
464 "locus", s.file, s.line);
467 else
468 pp_printf (context->printer, _(" inlined from %qs"),
469 identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
472 pp_colon (context->printer);
475 diagnostic_set_last_function (context, diagnostic);
476 pp_newline_and_flush (context->printer);
477 context->printer->prefix = old_prefix;
478 free ((char*) new_prefix);
482 tree
483 lhd_make_node (enum tree_code code)
485 return make_node (code);
488 HOST_WIDE_INT
489 lhd_to_target_charset (HOST_WIDE_INT c)
491 return c;
494 tree
495 lhd_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED, bool *se ATTRIBUTE_UNUSED)
497 return expr;
500 /* Return sharing kind if OpenMP sharing attribute of DECL is
501 predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise. */
503 enum omp_clause_default_kind
504 lhd_omp_predetermined_sharing (tree decl ATTRIBUTE_UNUSED)
506 if (DECL_ARTIFICIAL (decl))
507 return OMP_CLAUSE_DEFAULT_SHARED;
508 return OMP_CLAUSE_DEFAULT_UNSPECIFIED;
511 /* Generate code to copy SRC to DST. */
513 tree
514 lhd_omp_assignment (tree clause ATTRIBUTE_UNUSED, tree dst, tree src)
516 return build2 (MODIFY_EXPR, TREE_TYPE (dst), dst, src);
519 /* Finalize clause C. */
521 void
522 lhd_omp_finish_clause (tree, gimple_seq *)
526 /* Register language specific type size variables as potentially OpenMP
527 firstprivate variables. */
529 void
530 lhd_omp_firstprivatize_type_sizes (struct gimplify_omp_ctx *c ATTRIBUTE_UNUSED,
531 tree t ATTRIBUTE_UNUSED)
535 /* Return true if TYPE is an OpenMP mappable type. */
537 bool
538 lhd_omp_mappable_type (tree type)
540 /* Mappable type has to be complete. */
541 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
542 return false;
543 return true;
546 /* Common function for add_builtin_function and
547 add_builtin_function_ext_scope. */
548 static tree
549 add_builtin_function_common (const char *name,
550 tree type,
551 int function_code,
552 enum built_in_class cl,
553 const char *library_name,
554 tree attrs,
555 tree (*hook) (tree))
557 tree id = get_identifier (name);
558 tree decl = build_decl (BUILTINS_LOCATION, FUNCTION_DECL, id, type);
560 TREE_PUBLIC (decl) = 1;
561 DECL_EXTERNAL (decl) = 1;
562 DECL_BUILT_IN_CLASS (decl) = cl;
564 DECL_FUNCTION_CODE (decl) = (enum built_in_function) function_code;
566 /* DECL_FUNCTION_CODE is a bitfield; verify that the value fits. */
567 gcc_assert (DECL_FUNCTION_CODE (decl) == function_code);
569 if (library_name)
571 tree libname = get_identifier (library_name);
572 SET_DECL_ASSEMBLER_NAME (decl, libname);
575 /* Possibly apply some default attributes to this built-in function. */
576 if (attrs)
577 decl_attributes (&decl, attrs, ATTR_FLAG_BUILT_IN);
578 else
579 decl_attributes (&decl, NULL_TREE, 0);
581 return hook (decl);
585 /* Create a builtin function. */
587 tree
588 add_builtin_function (const char *name,
589 tree type,
590 int function_code,
591 enum built_in_class cl,
592 const char *library_name,
593 tree attrs)
595 return add_builtin_function_common (name, type, function_code, cl,
596 library_name, attrs,
597 lang_hooks.builtin_function);
600 /* Like add_builtin_function, but make sure the scope is the external scope.
601 This is used to delay putting in back end builtin functions until the ISA
602 that defines the builtin is declared via function specific target options,
603 which can save memory for machines like the x86_64 that have multiple ISAs.
604 If this points to the same function as builtin_function, the backend must
605 add all of the builtins at program initialization time. */
607 tree
608 add_builtin_function_ext_scope (const char *name,
609 tree type,
610 int function_code,
611 enum built_in_class cl,
612 const char *library_name,
613 tree attrs)
615 return add_builtin_function_common (name, type, function_code, cl,
616 library_name, attrs,
617 lang_hooks.builtin_function_ext_scope);
620 tree
621 lhd_builtin_function (tree decl)
623 lang_hooks.decls.pushdecl (decl);
624 return decl;
627 /* Create a builtin type. */
629 tree
630 add_builtin_type (const char *name, tree type)
632 tree id = get_identifier (name);
633 tree decl = build_decl (BUILTINS_LOCATION, TYPE_DECL, id, type);
634 return lang_hooks.decls.pushdecl (decl);
637 /* LTO hooks. */
639 /* Used to save and restore any previously active section. */
640 static section *saved_section;
643 /* Begin a new LTO output section named NAME. This default implementation
644 saves the old section and emits assembly code to switch to the new
645 section. */
647 void
648 lhd_begin_section (const char *name)
650 section *section;
652 /* Save the old section so we can restore it in lto_end_asm_section. */
653 gcc_assert (!saved_section);
654 saved_section = in_section;
655 if (!saved_section)
656 saved_section = text_section;
658 /* Create a new section and switch to it. */
659 section = get_section (name, SECTION_DEBUG | SECTION_EXCLUDE, NULL);
660 switch_to_section (section);
664 /* Write DATA of length LEN to the current LTO output section. This default
665 implementation just calls assemble_string. */
667 void
668 lhd_append_data (const void *data, size_t len, void *)
670 if (data)
671 assemble_string ((const char *)data, len);
675 /* Finish the current LTO output section. This default implementation emits
676 assembly code to switch to any section previously saved by
677 lhd_begin_section. */
679 void
680 lhd_end_section (void)
682 if (saved_section)
684 switch_to_section (saved_section);
685 saved_section = NULL;
689 /* Default implementation of enum_underlying_base_type using type_for_size. */
691 tree
692 lhd_enum_underlying_base_type (const_tree enum_type)
694 return lang_hooks.types.type_for_size (TYPE_PRECISION (enum_type),
695 TYPE_UNSIGNED (enum_type));
698 /* Returns true if the current lang_hooks represents the GNU C frontend. */
700 bool
701 lang_GNU_C (void)
703 return (strncmp (lang_hooks.name, "GNU C", 5) == 0
704 && (lang_hooks.name[5] == '\0' || ISDIGIT (lang_hooks.name[5])));
707 /* Returns true if the current lang_hooks represents the GNU C++ frontend. */
709 bool
710 lang_GNU_CXX (void)
712 return strncmp (lang_hooks.name, "GNU C++", 7) == 0;
715 /* Returns true if the current lang_hooks represents the GNU Fortran frontend. */
717 bool
718 lang_GNU_Fortran (void)
720 return strncmp (lang_hooks.name, "GNU Fortran", 11) == 0;