gcc/
[official-gcc.git] / gcc / langhooks.c
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1 /* Default language-specific hooks.
2 Copyright (C) 2001-2016 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 "target.h"
25 #include "rtl.h"
26 #include "tree.h"
27 #include "timevar.h"
28 #include "stringpool.h"
29 #include "diagnostic.h"
30 #include "intl.h"
31 #include "toplev.h"
32 #include "attribs.h"
33 #include "gimplify.h"
34 #include "langhooks.h"
35 #include "tree-diagnostic.h"
36 #include "output.h"
37 #include "timevar.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 ARG_UNUSED (t))
53 /* Pass through (tree). */
54 tree
55 lhd_pass_through_t (tree t)
57 return t;
60 /* Do nothing (int, int, int). Return NULL_TREE. */
62 tree
63 lhd_do_nothing_iii_return_null_tree (int ARG_UNUSED (i),
64 int ARG_UNUSED (j),
65 int ARG_UNUSED (k))
67 return NULL_TREE;
70 /* Do nothing (function). */
72 void
73 lhd_do_nothing_f (struct function * ARG_UNUSED (f))
77 /* Do nothing (return NULL_TREE). */
79 tree
80 lhd_return_null_tree_v (void)
82 return NULL_TREE;
85 /* Do nothing (return NULL_TREE). */
87 tree
88 lhd_return_null_tree (tree ARG_UNUSED (t))
90 return NULL_TREE;
93 /* Do nothing (return NULL_TREE). */
95 tree
96 lhd_return_null_const_tree (const_tree ARG_UNUSED (t))
98 return NULL_TREE;
101 /* The default post options hook. */
103 bool
104 lhd_post_options (const char ** ARG_UNUSED (pfilename))
106 /* Excess precision other than "fast" requires front-end
107 support. */
108 flag_excess_precision_cmdline = EXCESS_PRECISION_FAST;
109 return false;
112 /* Called from by print-tree.c. */
114 void
115 lhd_print_tree_nothing (FILE * ARG_UNUSED (file),
116 tree ARG_UNUSED (node),
117 int ARG_UNUSED (indent))
121 /* Called from check_global_declaration. */
123 bool
124 lhd_warn_unused_global_decl (const_tree decl)
126 /* This is what used to exist in check_global_declaration. Probably
127 not many of these actually apply to non-C languages. */
129 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (decl))
130 return false;
131 if (TREE_CODE (decl) == VAR_DECL && TREE_READONLY (decl))
132 return false;
133 if (DECL_IN_SYSTEM_HEADER (decl))
134 return false;
136 return true;
139 /* Set the DECL_ASSEMBLER_NAME for DECL. */
140 void
141 lhd_set_decl_assembler_name (tree decl)
143 tree id;
145 /* set_decl_assembler_name may be called on TYPE_DECL to record ODR
146 name for C++ types. By default types have no ODR names. */
147 if (TREE_CODE (decl) == TYPE_DECL)
148 return;
150 /* The language-independent code should never use the
151 DECL_ASSEMBLER_NAME for lots of DECLs. Only FUNCTION_DECLs and
152 VAR_DECLs for variables with static storage duration need a real
153 DECL_ASSEMBLER_NAME. */
154 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
155 || (TREE_CODE (decl) == VAR_DECL
156 && (TREE_STATIC (decl)
157 || DECL_EXTERNAL (decl)
158 || TREE_PUBLIC (decl))));
160 /* By default, assume the name to use in assembly code is the same
161 as that used in the source language. (That's correct for C, and
162 GCC used to set DECL_ASSEMBLER_NAME to the same value as
163 DECL_NAME in build_decl, so this choice provides backwards
164 compatibility with existing front-ends. This assumption is wrapped
165 in a target hook, to allow for target-specific modification of the
166 identifier.
168 Can't use just the variable's own name for a variable whose scope
169 is less than the whole compilation. Concatenate a distinguishing
170 number - we use the DECL_UID. */
172 if (TREE_PUBLIC (decl) || DECL_FILE_SCOPE_P (decl))
173 id = targetm.mangle_decl_assembler_name (decl, DECL_NAME (decl));
174 else
176 const char *name = IDENTIFIER_POINTER (DECL_NAME (decl));
177 char *label;
179 ASM_FORMAT_PRIVATE_NAME (label, name, DECL_UID (decl));
180 id = get_identifier (label);
182 SET_DECL_ASSEMBLER_NAME (decl, id);
186 /* Type promotion for variable arguments. */
187 tree
188 lhd_type_promotes_to (tree ARG_UNUSED (type))
190 gcc_unreachable ();
193 /* Registration of machine- or os-specific builtin types. */
194 void
195 lhd_register_builtin_type (tree ARG_UNUSED (type),
196 const char * ARG_UNUSED (name))
200 /* Invalid use of an incomplete type. */
201 void
202 lhd_incomplete_type_error (location_t ARG_UNUSED (loc),
203 const_tree ARG_UNUSED (value), const_tree type)
205 gcc_assert (TREE_CODE (type) == ERROR_MARK);
206 return;
209 /* Provide a default routine for alias sets that always returns -1. This
210 is used by languages that don't need to do anything special. */
212 alias_set_type
213 lhd_get_alias_set (tree ARG_UNUSED (t))
215 return -1;
218 /* This is the default decl_printable_name function. */
220 const char *
221 lhd_decl_printable_name (tree decl, int ARG_UNUSED (verbosity))
223 gcc_assert (decl && DECL_NAME (decl));
224 return IDENTIFIER_POINTER (DECL_NAME (decl));
227 /* This is the default dwarf_name function. */
229 const char *
230 lhd_dwarf_name (tree t, int verbosity)
232 gcc_assert (DECL_P (t));
234 return lang_hooks.decl_printable_name (t, verbosity);
237 /* This compares two types for equivalence ("compatible" in C-based languages).
238 This routine should only return 1 if it is sure. It should not be used
239 in contexts where erroneously returning 0 causes problems. */
242 lhd_types_compatible_p (tree x, tree y)
244 return TYPE_MAIN_VARIANT (x) == TYPE_MAIN_VARIANT (y);
247 /* lang_hooks.tree_dump.dump_tree: Dump language-specific parts of tree
248 nodes. Returns nonzero if it does not want the usual dumping of the
249 second argument. */
251 bool
252 lhd_tree_dump_dump_tree (void *di ATTRIBUTE_UNUSED, tree t ATTRIBUTE_UNUSED)
254 return false;
257 /* lang_hooks.tree_dump.type_qual: Determine type qualifiers in a
258 language-specific way. */
261 lhd_tree_dump_type_quals (const_tree t)
263 return TYPE_QUALS (t);
266 /* lang_hooks.gimplify_expr re-writes *EXPR_P into GIMPLE form. */
269 lhd_gimplify_expr (tree *expr_p ATTRIBUTE_UNUSED,
270 gimple_seq *pre_p ATTRIBUTE_UNUSED,
271 gimple_seq *post_p ATTRIBUTE_UNUSED)
273 return GS_UNHANDLED;
276 /* lang_hooks.tree_size: Determine the size of a tree with code C,
277 which is a language-specific tree code in category tcc_constant or
278 tcc_exceptional. The default expects never to be called. */
279 size_t
280 lhd_tree_size (enum tree_code c ATTRIBUTE_UNUSED)
282 gcc_unreachable ();
285 /* Return true if decl, which is a function decl, may be called by a
286 sibcall. */
288 bool
289 lhd_decl_ok_for_sibcall (const_tree decl ATTRIBUTE_UNUSED)
291 return true;
294 /* Generic global declaration processing. This is meant to be called
295 by the front-ends at the end of parsing. C/C++ do their own thing,
296 but other front-ends may call this. */
298 void
299 global_decl_processing (void)
301 tree globals, decl, *vec;
302 int len, i;
304 timevar_stop (TV_PHASE_PARSING);
305 timevar_start (TV_PHASE_DEFERRED);
306 /* Really define vars that have had only a tentative definition.
307 Really output inline functions that must actually be callable
308 and have not been output so far. */
310 globals = lang_hooks.decls.getdecls ();
311 len = list_length (globals);
312 vec = XNEWVEC (tree, len);
314 /* Process the decls in reverse order--earliest first.
315 Put them into VEC from back to front, then take out from front. */
317 for (i = 0, decl = globals; i < len; i++, decl = DECL_CHAIN (decl))
318 vec[len - i - 1] = decl;
320 wrapup_global_declarations (vec, len);
321 timevar_stop (TV_PHASE_DEFERRED);
323 timevar_start (TV_PHASE_PARSING);
324 free (vec);
327 /* Called to perform language-specific initialization of CTX. */
328 void
329 lhd_initialize_diagnostics (diagnostic_context *ctx ATTRIBUTE_UNUSED)
333 /* Called to perform language-specific options initialization. */
334 void
335 lhd_init_options (unsigned int decoded_options_count ATTRIBUTE_UNUSED,
336 struct cl_decoded_option *decoded_options ATTRIBUTE_UNUSED)
340 /* By default, always complain about options for the wrong language. */
341 bool
342 lhd_complain_wrong_lang_p (const struct cl_option *option ATTRIBUTE_UNUSED)
344 return true;
347 /* By default, no language-specific options are valid. */
348 bool
349 lhd_handle_option (size_t code ATTRIBUTE_UNUSED,
350 const char *arg ATTRIBUTE_UNUSED,
351 int value ATTRIBUTE_UNUSED, int kind ATTRIBUTE_UNUSED,
352 location_t loc ATTRIBUTE_UNUSED,
353 const struct cl_option_handlers *handlers ATTRIBUTE_UNUSED)
355 return false;
358 /* The default function to print out name of current function that caused
359 an error. */
360 void
361 lhd_print_error_function (diagnostic_context *context, const char *file,
362 diagnostic_info *diagnostic)
364 if (diagnostic_last_function_changed (context, diagnostic))
366 const char *old_prefix = context->printer->prefix;
367 tree abstract_origin = diagnostic_abstract_origin (diagnostic);
368 char *new_prefix = (file && abstract_origin == NULL)
369 ? file_name_as_prefix (context, file) : NULL;
371 pp_set_prefix (context->printer, new_prefix);
373 if (current_function_decl == NULL)
374 pp_printf (context->printer, _("At top level:"));
375 else
377 tree fndecl, ao;
379 if (abstract_origin)
381 ao = BLOCK_ABSTRACT_ORIGIN (abstract_origin);
382 while (TREE_CODE (ao) == BLOCK
383 && BLOCK_ABSTRACT_ORIGIN (ao)
384 && BLOCK_ABSTRACT_ORIGIN (ao) != ao)
385 ao = BLOCK_ABSTRACT_ORIGIN (ao);
386 gcc_assert (TREE_CODE (ao) == FUNCTION_DECL);
387 fndecl = ao;
389 else
390 fndecl = current_function_decl;
392 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
393 pp_printf
394 (context->printer, _("In member function %qs"),
395 identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
396 else
397 pp_printf
398 (context->printer, _("In function %qs"),
399 identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
401 while (abstract_origin)
403 location_t *locus;
404 tree block = abstract_origin;
406 locus = &BLOCK_SOURCE_LOCATION (block);
407 fndecl = NULL;
408 block = BLOCK_SUPERCONTEXT (block);
409 while (block && TREE_CODE (block) == BLOCK
410 && BLOCK_ABSTRACT_ORIGIN (block))
412 ao = BLOCK_ABSTRACT_ORIGIN (block);
414 while (TREE_CODE (ao) == BLOCK
415 && BLOCK_ABSTRACT_ORIGIN (ao)
416 && BLOCK_ABSTRACT_ORIGIN (ao) != ao)
417 ao = BLOCK_ABSTRACT_ORIGIN (ao);
419 if (TREE_CODE (ao) == FUNCTION_DECL)
421 fndecl = ao;
422 break;
424 else if (TREE_CODE (ao) != BLOCK)
425 break;
427 block = BLOCK_SUPERCONTEXT (block);
429 if (fndecl)
430 abstract_origin = block;
431 else
433 while (block && TREE_CODE (block) == BLOCK)
434 block = BLOCK_SUPERCONTEXT (block);
436 if (block && TREE_CODE (block) == FUNCTION_DECL)
437 fndecl = block;
438 abstract_origin = NULL;
440 if (fndecl)
442 expanded_location s = expand_location (*locus);
443 pp_comma (context->printer);
444 pp_newline (context->printer);
445 if (s.file != NULL)
447 if (context->show_column)
448 pp_printf (context->printer,
449 _(" inlined from %qs at %r%s:%d:%d%R"),
450 identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)),
451 "locus", s.file, s.line, s.column);
452 else
453 pp_printf (context->printer,
454 _(" inlined from %qs at %r%s:%d%R"),
455 identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)),
456 "locus", s.file, s.line);
459 else
460 pp_printf (context->printer, _(" inlined from %qs"),
461 identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
464 pp_colon (context->printer);
467 diagnostic_set_last_function (context, diagnostic);
468 pp_newline_and_flush (context->printer);
469 context->printer->prefix = old_prefix;
470 free ((char*) new_prefix);
474 tree
475 lhd_make_node (enum tree_code code)
477 return make_node (code);
480 HOST_WIDE_INT
481 lhd_to_target_charset (HOST_WIDE_INT c)
483 return c;
486 tree
487 lhd_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED, bool *se ATTRIBUTE_UNUSED)
489 return expr;
492 /* Return sharing kind if OpenMP sharing attribute of DECL is
493 predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise. */
495 enum omp_clause_default_kind
496 lhd_omp_predetermined_sharing (tree decl ATTRIBUTE_UNUSED)
498 if (DECL_ARTIFICIAL (decl))
499 return OMP_CLAUSE_DEFAULT_SHARED;
500 return OMP_CLAUSE_DEFAULT_UNSPECIFIED;
503 /* Generate code to copy SRC to DST. */
505 tree
506 lhd_omp_assignment (tree clause ATTRIBUTE_UNUSED, tree dst, tree src)
508 return build2 (MODIFY_EXPR, TREE_TYPE (dst), dst, src);
511 /* Finalize clause C. */
513 void
514 lhd_omp_finish_clause (tree, gimple_seq *)
518 /* Register language specific type size variables as potentially OpenMP
519 firstprivate variables. */
521 void
522 lhd_omp_firstprivatize_type_sizes (struct gimplify_omp_ctx *c ATTRIBUTE_UNUSED,
523 tree t ATTRIBUTE_UNUSED)
527 /* Return true if TYPE is an OpenMP mappable type. */
529 bool
530 lhd_omp_mappable_type (tree type)
532 /* Mappable type has to be complete. */
533 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
534 return false;
535 return true;
538 /* Common function for add_builtin_function and
539 add_builtin_function_ext_scope. */
540 static tree
541 add_builtin_function_common (const char *name,
542 tree type,
543 int function_code,
544 enum built_in_class cl,
545 const char *library_name,
546 tree attrs,
547 tree (*hook) (tree))
549 tree id = get_identifier (name);
550 tree decl = build_decl (BUILTINS_LOCATION, FUNCTION_DECL, id, type);
552 TREE_PUBLIC (decl) = 1;
553 DECL_EXTERNAL (decl) = 1;
554 DECL_BUILT_IN_CLASS (decl) = cl;
556 DECL_FUNCTION_CODE (decl) = (enum built_in_function) function_code;
558 /* DECL_FUNCTION_CODE is a bitfield; verify that the value fits. */
559 gcc_assert (DECL_FUNCTION_CODE (decl) == function_code);
561 if (library_name)
563 tree libname = get_identifier (library_name);
565 libname = targetm.mangle_decl_assembler_name (decl, libname);
566 SET_DECL_ASSEMBLER_NAME (decl, libname);
569 /* Possibly apply some default attributes to this built-in function. */
570 if (attrs)
571 decl_attributes (&decl, attrs, ATTR_FLAG_BUILT_IN);
572 else
573 decl_attributes (&decl, NULL_TREE, 0);
575 return hook (decl);
579 /* Create a builtin function. */
581 tree
582 add_builtin_function (const char *name,
583 tree type,
584 int function_code,
585 enum built_in_class cl,
586 const char *library_name,
587 tree attrs)
589 return add_builtin_function_common (name, type, function_code, cl,
590 library_name, attrs,
591 lang_hooks.builtin_function);
594 /* Like add_builtin_function, but make sure the scope is the external scope.
595 This is used to delay putting in back end builtin functions until the ISA
596 that defines the builtin is declared via function specific target options,
597 which can save memory for machines like the x86_64 that have multiple ISAs.
598 If this points to the same function as builtin_function, the backend must
599 add all of the builtins at program initialization time. */
601 tree
602 add_builtin_function_ext_scope (const char *name,
603 tree type,
604 int function_code,
605 enum built_in_class cl,
606 const char *library_name,
607 tree attrs)
609 return add_builtin_function_common (name, type, function_code, cl,
610 library_name, attrs,
611 lang_hooks.builtin_function_ext_scope);
614 tree
615 lhd_builtin_function (tree decl)
617 lang_hooks.decls.pushdecl (decl);
618 return decl;
621 /* Create a builtin type. */
623 tree
624 add_builtin_type (const char *name, tree type)
626 tree id = get_identifier (name);
627 tree decl = build_decl (BUILTINS_LOCATION, TYPE_DECL, id, type);
628 return lang_hooks.decls.pushdecl (decl);
631 /* LTO hooks. */
633 /* Used to save and restore any previously active section. */
634 static section *saved_section;
637 /* Begin a new LTO output section named NAME. This default implementation
638 saves the old section and emits assembly code to switch to the new
639 section. */
641 void
642 lhd_begin_section (const char *name)
644 section *section;
646 /* Save the old section so we can restore it in lto_end_asm_section. */
647 gcc_assert (!saved_section);
648 saved_section = in_section;
649 if (!saved_section)
650 saved_section = text_section;
652 /* Create a new section and switch to it. */
653 section = get_section (name, SECTION_DEBUG | SECTION_EXCLUDE, NULL);
654 switch_to_section (section);
658 /* Write DATA of length LEN to the current LTO output section. This default
659 implementation just calls assemble_string. */
661 void
662 lhd_append_data (const void *data, size_t len, void *)
664 if (data)
666 timevar_push (TV_IPA_LTO_OUTPUT);
667 assemble_string ((const char *)data, len);
668 timevar_pop (TV_IPA_LTO_OUTPUT);
673 /* Finish the current LTO output section. This default implementation emits
674 assembly code to switch to any section previously saved by
675 lhd_begin_section. */
677 void
678 lhd_end_section (void)
680 if (saved_section)
682 switch_to_section (saved_section);
683 saved_section = NULL;
687 /* Default implementation of enum_underlying_base_type using type_for_size. */
689 tree
690 lhd_enum_underlying_base_type (const_tree enum_type)
692 return lang_hooks.types.type_for_size (TYPE_PRECISION (enum_type),
693 TYPE_UNSIGNED (enum_type));
696 /* Returns true if the current lang_hooks represents the GNU C frontend. */
698 bool
699 lang_GNU_C (void)
701 return (strncmp (lang_hooks.name, "GNU C", 5) == 0
702 && (lang_hooks.name[5] == '\0' || ISDIGIT (lang_hooks.name[5])));
705 /* Returns true if the current lang_hooks represents the GNU C++ frontend. */
707 bool
708 lang_GNU_CXX (void)
710 return strncmp (lang_hooks.name, "GNU C++", 7) == 0;
713 /* Returns true if the current lang_hooks represents the GNU Fortran frontend. */
715 bool
716 lang_GNU_Fortran (void)
718 return strncmp (lang_hooks.name, "GNU Fortran", 11) == 0;