xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/langhooks.c (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /* Default language-specific hooks.
2    Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
3    Free Software Foundation, Inc.
4    Contributed by Alexandre Oliva  <aoliva@redhat.com>
5 
6 This file is part of GCC.
7 
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
12 
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 GNU General Public License for more details.
17 
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3.  If not see
20 <http://www.gnu.org/licenses/>.  */
21 
22 #include "config.h"
23 #include "system.h"
24 #include "coretypes.h"
25 #include "intl.h"
26 #include "tm.h"
27 #include "toplev.h"
28 #include "tree.h"
29 #include "tree-inline.h"
30 #include "gimple.h"
31 #include "rtl.h"
32 #include "insn-config.h"
33 #include "integrate.h"
34 #include "flags.h"
35 #include "langhooks.h"
36 #include "target.h"
37 #include "langhooks-def.h"
38 #include "ggc.h"
39 #include "diagnostic.h"
40 #include "cgraph.h"
41 #include "output.h"
42 
43 /* Do nothing; in many cases the default hook.  */
44 
45 void
46 lhd_do_nothing (void)
47 {
48 }
49 
50 /* Do nothing (tree).  */
51 
52 void
53 lhd_do_nothing_t (tree ARG_UNUSED (t))
54 {
55 }
56 
57 /* Pass through (tree).  */
58 tree
59 lhd_pass_through_t (tree t)
60 {
61   return t;
62 }
63 
64 /* Do nothing (int).  */
65 
66 void
67 lhd_do_nothing_i (int ARG_UNUSED (i))
68 {
69 }
70 
71 /* Do nothing (int, int, int).  Return NULL_TREE.  */
72 
73 tree
74 lhd_do_nothing_iii_return_null_tree (int ARG_UNUSED (i),
75 				     int ARG_UNUSED (j),
76 				     int ARG_UNUSED (k))
77 {
78   return NULL_TREE;
79 }
80 
81 /* Do nothing (function).  */
82 
83 void
84 lhd_do_nothing_f (struct function * ARG_UNUSED (f))
85 {
86 }
87 
88 /* Do nothing (return NULL_TREE).  */
89 
90 tree
91 lhd_return_null_tree_v (void)
92 {
93   return NULL_TREE;
94 }
95 
96 /* Do nothing (return NULL_TREE).  */
97 
98 tree
99 lhd_return_null_tree (tree ARG_UNUSED (t))
100 {
101   return NULL_TREE;
102 }
103 
104 /* Do nothing (return NULL_TREE).  */
105 
106 tree
107 lhd_return_null_const_tree (const_tree ARG_UNUSED (t))
108 {
109   return NULL_TREE;
110 }
111 
112 /* The default post options hook.  */
113 
114 bool
115 lhd_post_options (const char ** ARG_UNUSED (pfilename))
116 {
117   /* Excess precision other than "fast" requires front-end
118      support.  */
119   flag_excess_precision_cmdline = EXCESS_PRECISION_FAST;
120   return false;
121 }
122 
123 /* Called from by print-tree.c.  */
124 
125 void
126 lhd_print_tree_nothing (FILE * ARG_UNUSED (file),
127 			tree ARG_UNUSED (node),
128 			int ARG_UNUSED (indent))
129 {
130 }
131 
132 /* Called from check_global_declarations.  */
133 
134 bool
135 lhd_warn_unused_global_decl (const_tree decl)
136 {
137   /* This is what used to exist in check_global_declarations.  Probably
138      not many of these actually apply to non-C languages.  */
139 
140   if (TREE_CODE (decl) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (decl))
141     return false;
142   if (TREE_CODE (decl) == VAR_DECL && TREE_READONLY (decl))
143     return false;
144   if (DECL_IN_SYSTEM_HEADER (decl))
145     return false;
146 
147   return true;
148 }
149 
150 /* Set the DECL_ASSEMBLER_NAME for DECL.  */
151 void
152 lhd_set_decl_assembler_name (tree decl)
153 {
154   tree id;
155 
156   /* The language-independent code should never use the
157      DECL_ASSEMBLER_NAME for lots of DECLs.  Only FUNCTION_DECLs and
158      VAR_DECLs for variables with static storage duration need a real
159      DECL_ASSEMBLER_NAME.  */
160   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
161 	      || (TREE_CODE (decl) == VAR_DECL
162 		  && (TREE_STATIC (decl)
163 		      || DECL_EXTERNAL (decl)
164 		      || TREE_PUBLIC (decl))));
165 
166   /* By default, assume the name to use in assembly code is the same
167      as that used in the source language.  (That's correct for C, and
168      GCC used to set DECL_ASSEMBLER_NAME to the same value as
169      DECL_NAME in build_decl, so this choice provides backwards
170      compatibility with existing front-ends.  This assumption is wrapped
171      in a target hook, to allow for target-specific modification of the
172      identifier.
173 
174      Can't use just the variable's own name for a variable whose scope
175      is less than the whole compilation.  Concatenate a distinguishing
176      number - we use the DECL_UID.  */
177 
178   if (TREE_PUBLIC (decl) || DECL_CONTEXT (decl) == NULL_TREE)
179     id = targetm.mangle_decl_assembler_name (decl, DECL_NAME (decl));
180   else
181     {
182       const char *name = IDENTIFIER_POINTER (DECL_NAME (decl));
183       char *label;
184 
185       ASM_FORMAT_PRIVATE_NAME (label, name, DECL_UID (decl));
186       id = get_identifier (label);
187     }
188   SET_DECL_ASSEMBLER_NAME (decl, id);
189 
190 }
191 
192 /* Type promotion for variable arguments.  */
193 tree
194 lhd_type_promotes_to (tree ARG_UNUSED (type))
195 {
196   gcc_unreachable ();
197 }
198 
199 /* Registration of machine- or os-specific builtin types.  */
200 void
201 lhd_register_builtin_type (tree ARG_UNUSED (type),
202 			   const char * ARG_UNUSED (name))
203 {
204 }
205 
206 /* Invalid use of an incomplete type.  */
207 void
208 lhd_incomplete_type_error (const_tree ARG_UNUSED (value), const_tree type)
209 {
210   gcc_assert (TREE_CODE (type) == ERROR_MARK);
211   return;
212 }
213 
214 /* Provide a default routine for alias sets that always returns -1.  This
215    is used by languages that don't need to do anything special.  */
216 
217 alias_set_type
218 lhd_get_alias_set (tree ARG_UNUSED (t))
219 {
220   return -1;
221 }
222 
223 /* This is the default decl_printable_name function.  */
224 
225 const char *
226 lhd_decl_printable_name (tree decl, int ARG_UNUSED (verbosity))
227 {
228   gcc_assert (decl && DECL_NAME (decl));
229   return IDENTIFIER_POINTER (DECL_NAME (decl));
230 }
231 
232 /* This is the default dwarf_name function.  */
233 
234 const char *
235 lhd_dwarf_name (tree t, int verbosity)
236 {
237   gcc_assert (DECL_P (t));
238 
239   return lang_hooks.decl_printable_name (t, verbosity);
240 }
241 
242 /* This compares two types for equivalence ("compatible" in C-based languages).
243    This routine should only return 1 if it is sure.  It should not be used
244    in contexts where erroneously returning 0 causes problems.  */
245 
246 int
247 lhd_types_compatible_p (tree x, tree y)
248 {
249   return TYPE_MAIN_VARIANT (x) == TYPE_MAIN_VARIANT (y);
250 }
251 
252 /* lang_hooks.tree_dump.dump_tree:  Dump language-specific parts of tree
253    nodes.  Returns nonzero if it does not want the usual dumping of the
254    second argument.  */
255 
256 bool
257 lhd_tree_dump_dump_tree (void *di ATTRIBUTE_UNUSED, tree t ATTRIBUTE_UNUSED)
258 {
259   return false;
260 }
261 
262 /* lang_hooks.tree_dump.type_qual:  Determine type qualifiers in a
263    language-specific way.  */
264 
265 int
266 lhd_tree_dump_type_quals (const_tree t)
267 {
268   return TYPE_QUALS (t);
269 }
270 
271 /* lang_hooks.gimplify_expr re-writes *EXPR_P into GIMPLE form.  */
272 
273 int
274 lhd_gimplify_expr (tree *expr_p ATTRIBUTE_UNUSED,
275 		   gimple_seq *pre_p ATTRIBUTE_UNUSED,
276 		   gimple_seq *post_p ATTRIBUTE_UNUSED)
277 {
278   return GS_UNHANDLED;
279 }
280 
281 /* lang_hooks.tree_size: Determine the size of a tree with code C,
282    which is a language-specific tree code in category tcc_constant or
283    tcc_exceptional.  The default expects never to be called.  */
284 size_t
285 lhd_tree_size (enum tree_code c ATTRIBUTE_UNUSED)
286 {
287   gcc_unreachable ();
288 }
289 
290 /* Return true if decl, which is a function decl, may be called by a
291    sibcall.  */
292 
293 bool
294 lhd_decl_ok_for_sibcall (const_tree decl ATTRIBUTE_UNUSED)
295 {
296   return true;
297 }
298 
299 /* lang_hooks.decls.final_write_globals: perform final processing on
300    global variables.  */
301 void
302 write_global_declarations (void)
303 {
304   tree globals, decl, *vec;
305   int len, i;
306 
307   /* This lang hook is dual-purposed, and also finalizes the
308      compilation unit.  */
309   cgraph_finalize_compilation_unit ();
310 
311   /* Really define vars that have had only a tentative definition.
312      Really output inline functions that must actually be callable
313      and have not been output so far.  */
314 
315   globals = lang_hooks.decls.getdecls ();
316   len = list_length (globals);
317   vec = XNEWVEC (tree, len);
318 
319   /* Process the decls in reverse order--earliest first.
320      Put them into VEC from back to front, then take out from front.  */
321 
322   for (i = 0, decl = globals; i < len; i++, decl = TREE_CHAIN (decl))
323     vec[len - i - 1] = decl;
324 
325   wrapup_global_declarations (vec, len);
326   check_global_declarations (vec, len);
327   emit_debug_global_declarations (vec, len);
328 
329   /* Clean up.  */
330   free (vec);
331 }
332 
333 /* Called to perform language-specific initialization of CTX.  */
334 void
335 lhd_initialize_diagnostics (struct diagnostic_context *ctx ATTRIBUTE_UNUSED)
336 {
337 }
338 
339 /* The default function to print out name of current function that caused
340    an error.  */
341 void
342 lhd_print_error_function (diagnostic_context *context, const char *file,
343 			  diagnostic_info *diagnostic)
344 {
345   if (diagnostic_last_function_changed (context, diagnostic))
346     {
347       const char *old_prefix = context->printer->prefix;
348       tree abstract_origin = diagnostic->abstract_origin;
349       char *new_prefix = (file && abstract_origin == NULL)
350 			 ? file_name_as_prefix (file) : NULL;
351 
352       pp_set_prefix (context->printer, new_prefix);
353 
354       if (current_function_decl == NULL)
355 	pp_printf (context->printer, _("At top level:"));
356       else
357 	{
358 	  tree fndecl, ao;
359 
360 	  if (abstract_origin)
361 	    {
362 	      ao = BLOCK_ABSTRACT_ORIGIN (abstract_origin);
363 	      while (TREE_CODE (ao) == BLOCK
364 		     && BLOCK_ABSTRACT_ORIGIN (ao)
365 		     && BLOCK_ABSTRACT_ORIGIN (ao) != ao)
366 		ao = BLOCK_ABSTRACT_ORIGIN (ao);
367 	      gcc_assert (TREE_CODE (ao) == FUNCTION_DECL);
368 	      fndecl = ao;
369 	    }
370 	  else
371 	    fndecl = current_function_decl;
372 
373 	  if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
374 	    pp_printf
375 	      (context->printer, _("In member function %qs"),
376 	       identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
377 	  else
378 	    pp_printf
379 	      (context->printer, _("In function %qs"),
380 	       identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
381 
382 	  while (abstract_origin)
383 	    {
384 	      location_t *locus;
385 	      tree block = abstract_origin;
386 
387 	      locus = &BLOCK_SOURCE_LOCATION (block);
388 	      fndecl = NULL;
389 	      block = BLOCK_SUPERCONTEXT (block);
390 	      while (block && TREE_CODE (block) == BLOCK
391 		     && BLOCK_ABSTRACT_ORIGIN (block))
392 		{
393 		  ao = BLOCK_ABSTRACT_ORIGIN (block);
394 
395 		  while (TREE_CODE (ao) == BLOCK
396 			 && BLOCK_ABSTRACT_ORIGIN (ao)
397 			 && BLOCK_ABSTRACT_ORIGIN (ao) != ao)
398 		    ao = BLOCK_ABSTRACT_ORIGIN (ao);
399 
400 		  if (TREE_CODE (ao) == FUNCTION_DECL)
401 		    {
402 		      fndecl = ao;
403 		      break;
404 		    }
405 		  else if (TREE_CODE (ao) != BLOCK)
406 		    break;
407 
408 		  block = BLOCK_SUPERCONTEXT (block);
409 		}
410 	      if (fndecl)
411 		abstract_origin = block;
412 	      else
413 		{
414 		  while (block && TREE_CODE (block) == BLOCK)
415 		    block = BLOCK_SUPERCONTEXT (block);
416 
417 		  if (block && TREE_CODE (block) == FUNCTION_DECL)
418 		    fndecl = block;
419 		  abstract_origin = NULL;
420 		}
421 	      if (fndecl)
422 		{
423 		  expanded_location s = expand_location (*locus);
424 		  pp_character (context->printer, ',');
425 		  pp_newline (context->printer);
426 		  if (s.file != NULL)
427 		    {
428 		      if (flag_show_column)
429 			pp_printf (context->printer,
430 				   _("    inlined from %qs at %s:%d:%d"),
431 				   identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)),
432 				   s.file, s.line, s.column);
433 		      else
434 			pp_printf (context->printer,
435 				   _("    inlined from %qs at %s:%d"),
436 				   identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)),
437 				   s.file, s.line);
438 
439 		    }
440 		  else
441 		    pp_printf (context->printer, _("    inlined from %qs"),
442 			       identifier_to_locale (lang_hooks.decl_printable_name (fndecl, 2)));
443 		}
444 	    }
445 	  pp_character (context->printer, ':');
446 	}
447 
448       diagnostic_set_last_function (context, diagnostic);
449       pp_flush (context->printer);
450       context->printer->prefix = old_prefix;
451       free ((char*) new_prefix);
452     }
453 }
454 
455 tree
456 lhd_callgraph_analyze_expr (tree *tp ATTRIBUTE_UNUSED,
457 			    int *walk_subtrees ATTRIBUTE_UNUSED)
458 {
459   return NULL;
460 }
461 
462 tree
463 lhd_make_node (enum tree_code code)
464 {
465   return make_node (code);
466 }
467 
468 HOST_WIDE_INT
469 lhd_to_target_charset (HOST_WIDE_INT c)
470 {
471   return c;
472 }
473 
474 tree
475 lhd_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED, bool *se ATTRIBUTE_UNUSED)
476 {
477   return expr;
478 }
479 
480 /* Return sharing kind if OpenMP sharing attribute of DECL is
481    predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
482 
483 enum omp_clause_default_kind
484 lhd_omp_predetermined_sharing (tree decl ATTRIBUTE_UNUSED)
485 {
486   if (DECL_ARTIFICIAL (decl))
487     return OMP_CLAUSE_DEFAULT_SHARED;
488   return OMP_CLAUSE_DEFAULT_UNSPECIFIED;
489 }
490 
491 /* Generate code to copy SRC to DST.  */
492 
493 tree
494 lhd_omp_assignment (tree clause ATTRIBUTE_UNUSED, tree dst, tree src)
495 {
496   return build2 (MODIFY_EXPR, TREE_TYPE (dst), dst, src);
497 }
498 
499 /* Register language specific type size variables as potentially OpenMP
500    firstprivate variables.  */
501 
502 void
503 lhd_omp_firstprivatize_type_sizes (struct gimplify_omp_ctx *c ATTRIBUTE_UNUSED,
504 				   tree t ATTRIBUTE_UNUSED)
505 {
506 }
507 
508 /* Common function for add_builtin_function and
509    add_builtin_function_ext_scope.  */
510 static tree
511 add_builtin_function_common (const char *name,
512 			     tree type,
513 			     int function_code,
514 			     enum built_in_class cl,
515 			     const char *library_name,
516 			     tree attrs,
517 			     tree (*hook) (tree))
518 {
519   tree   id = get_identifier (name);
520   tree decl = build_decl (BUILTINS_LOCATION, FUNCTION_DECL, id, type);
521 
522   TREE_PUBLIC (decl)         = 1;
523   DECL_EXTERNAL (decl)       = 1;
524   DECL_BUILT_IN_CLASS (decl) = cl;
525 
526   DECL_FUNCTION_CODE (decl)  = (enum built_in_function) function_code;
527 
528   /* DECL_FUNCTION_CODE is a bitfield; verify that the value fits.  */
529   gcc_assert (DECL_FUNCTION_CODE (decl) == function_code);
530 
531   if (library_name)
532     {
533       tree libname = get_identifier (library_name);
534       SET_DECL_ASSEMBLER_NAME (decl, libname);
535     }
536 
537   /* Possibly apply some default attributes to this built-in function.  */
538   if (attrs)
539     decl_attributes (&decl, attrs, ATTR_FLAG_BUILT_IN);
540   else
541     decl_attributes (&decl, NULL_TREE, 0);
542 
543   return hook (decl);
544 
545 }
546 
547 /* Create a builtin function.  */
548 
549 tree
550 add_builtin_function (const char *name,
551 		      tree type,
552 		      int function_code,
553 		      enum built_in_class cl,
554 		      const char *library_name,
555 		      tree attrs)
556 {
557   return add_builtin_function_common (name, type, function_code, cl,
558 				      library_name, attrs,
559 				      lang_hooks.builtin_function);
560 }
561 
562 /* Like add_builtin_function, but make sure the scope is the external scope.
563    This is used to delay putting in back end builtin functions until the ISA
564    that defines the builtin is declared via function specific target options,
565    which can save memory for machines like the x86_64 that have multiple ISAs.
566    If this points to the same function as builtin_function, the backend must
567    add all of the builtins at program initialization time.  */
568 
569 tree
570 add_builtin_function_ext_scope (const char *name,
571 				tree type,
572 				int function_code,
573 				enum built_in_class cl,
574 				const char *library_name,
575 				tree attrs)
576 {
577   return add_builtin_function_common (name, type, function_code, cl,
578 				      library_name, attrs,
579 				      lang_hooks.builtin_function_ext_scope);
580 }
581 
582 tree
583 lhd_builtin_function (tree decl)
584 {
585   lang_hooks.decls.pushdecl (decl);
586   return decl;
587 }
588 
589 /* LTO hooks.  */
590 
591 /* Used to save and restore any previously active section.  */
592 static section *saved_section;
593 
594 
595 /* Begin a new LTO output section named NAME.  This default implementation
596    saves the old section and emits assembly code to switch to the new
597    section.  */
598 
599 void
600 lhd_begin_section (const char *name)
601 {
602   section *section;
603 
604   /* Save the old section so we can restore it in lto_end_asm_section.  */
605   gcc_assert (!saved_section);
606   saved_section = in_section;
607   if (!saved_section)
608     saved_section = text_section;
609 
610   /* Create a new section and switch to it.  */
611   section = get_section (name, SECTION_DEBUG, NULL);
612   switch_to_section (section);
613 }
614 
615 
616 /* Write DATA of length LEN to the current LTO output section.  This default
617    implementation just calls assemble_string and frees BLOCK.  */
618 
619 void
620 lhd_append_data (const void *data, size_t len, void *block)
621 {
622   if (data)
623     assemble_string ((const char *)data, len);
624   free (block);
625 }
626 
627 
628 /* Finish the current LTO output section.  This default implementation emits
629    assembly code to switch to any section previously saved by
630    lhd_begin_section.  */
631 
632 void
633 lhd_end_section (void)
634 {
635   if (saved_section)
636     {
637       switch_to_section (saved_section);
638       saved_section = NULL;
639     }
640 }
641