xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/cp/lex.c (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /* Separate lexical analyzer for GNU C++.
2    Copyright (C) 1987, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3    1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008
4    Free Software Foundation, Inc.
5    Hacked by Michael Tiemann (tiemann@cygnus.com)
6 
7 This file is part of GCC.
8 
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3, or (at your option)
12 any later version.
13 
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17 GNU General Public License for more details.
18 
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3.  If not see
21 <http://www.gnu.org/licenses/>.  */
22 
23 
24 /* This file is the lexical analyzer for GNU C++.  */
25 
26 #include "config.h"
27 #include "system.h"
28 #include "coretypes.h"
29 #include "tm.h"
30 #include "input.h"
31 #include "tree.h"
32 #include "cp-tree.h"
33 #include "cpplib.h"
34 #include "flags.h"
35 #include "c-pragma.h"
36 #include "toplev.h"
37 #include "output.h"
38 #include "tm_p.h"
39 #include "timevar.h"
40 
41 static int interface_strcmp (const char *);
42 static void init_cp_pragma (void);
43 
44 static tree parse_strconst_pragma (const char *, int);
45 static void handle_pragma_vtable (cpp_reader *);
46 static void handle_pragma_unit (cpp_reader *);
47 static void handle_pragma_interface (cpp_reader *);
48 static void handle_pragma_implementation (cpp_reader *);
49 static void handle_pragma_java_exceptions (cpp_reader *);
50 
51 static void init_operators (void);
52 static void copy_lang_type (tree);
53 
54 /* A constraint that can be tested at compile time.  */
55 #define CONSTRAINT(name, expr) extern int constraint_##name [(expr) ? 1 : -1]
56 
57 /* Functions and data structures for #pragma interface.
58 
59    `#pragma implementation' means that the main file being compiled
60    is considered to implement (provide) the classes that appear in
61    its main body.  I.e., if this is file "foo.cc", and class `bar'
62    is defined in "foo.cc", then we say that "foo.cc implements bar".
63 
64    All main input files "implement" themselves automagically.
65 
66    `#pragma interface' means that unless this file (of the form "foo.h"
67    is not presently being included by file "foo.cc", the
68    CLASSTYPE_INTERFACE_ONLY bit gets set.  The effect is that none
69    of the vtables nor any of the inline functions defined in foo.h
70    will ever be output.
71 
72    There are cases when we want to link files such as "defs.h" and
73    "main.cc".  In this case, we give "defs.h" a `#pragma interface',
74    and "main.cc" has `#pragma implementation "defs.h"'.  */
75 
76 struct impl_files
77 {
78   const char *filename;
79   struct impl_files *next;
80 };
81 
82 static struct impl_files *impl_file_chain;
83 
84 /* True if we saw "#pragma GCC java_exceptions".  */
85 bool pragma_java_exceptions;
86 
87 void
88 cxx_finish (void)
89 {
90   c_common_finish ();
91 }
92 
93 /* A mapping from tree codes to operator name information.  */
94 operator_name_info_t operator_name_info[(int) MAX_TREE_CODES];
95 /* Similar, but for assignment operators.  */
96 operator_name_info_t assignment_operator_name_info[(int) MAX_TREE_CODES];
97 
98 /* Initialize data structures that keep track of operator names.  */
99 
100 #define DEF_OPERATOR(NAME, C, M, AR, AP) \
101  CONSTRAINT (C, sizeof "operator " + sizeof NAME <= 256);
102 #include "operators.def"
103 #undef DEF_OPERATOR
104 
105 static void
106 init_operators (void)
107 {
108   tree identifier;
109   char buffer[256];
110   struct operator_name_info_t *oni;
111 
112 #define DEF_OPERATOR(NAME, CODE, MANGLING, ARITY, ASSN_P)		    \
113   sprintf (buffer, ISALPHA (NAME[0]) ? "operator %s" : "operator%s", NAME); \
114   identifier = get_identifier (buffer);					    \
115   IDENTIFIER_OPNAME_P (identifier) = 1;					    \
116 									    \
117   oni = (ASSN_P								    \
118 	 ? &assignment_operator_name_info[(int) CODE]			    \
119 	 : &operator_name_info[(int) CODE]);				    \
120   oni->identifier = identifier;						    \
121   oni->name = NAME;							    \
122   oni->mangled_name = MANGLING;						    \
123   oni->arity = ARITY;
124 
125 #include "operators.def"
126 #undef DEF_OPERATOR
127 
128   operator_name_info[(int) ERROR_MARK].identifier
129     = get_identifier ("<invalid operator>");
130 
131   /* Handle some special cases.  These operators are not defined in
132      the language, but can be produced internally.  We may need them
133      for error-reporting.  (Eventually, we should ensure that this
134      does not happen.  Error messages involving these operators will
135      be confusing to users.)  */
136 
137   operator_name_info [(int) INIT_EXPR].name
138     = operator_name_info [(int) MODIFY_EXPR].name;
139   operator_name_info [(int) EXACT_DIV_EXPR].name = "(ceiling /)";
140   operator_name_info [(int) CEIL_DIV_EXPR].name = "(ceiling /)";
141   operator_name_info [(int) FLOOR_DIV_EXPR].name = "(floor /)";
142   operator_name_info [(int) ROUND_DIV_EXPR].name = "(round /)";
143   operator_name_info [(int) CEIL_MOD_EXPR].name = "(ceiling %)";
144   operator_name_info [(int) FLOOR_MOD_EXPR].name = "(floor %)";
145   operator_name_info [(int) ROUND_MOD_EXPR].name = "(round %)";
146   operator_name_info [(int) ABS_EXPR].name = "abs";
147   operator_name_info [(int) TRUTH_AND_EXPR].name = "strict &&";
148   operator_name_info [(int) TRUTH_OR_EXPR].name = "strict ||";
149   operator_name_info [(int) RANGE_EXPR].name = "...";
150   operator_name_info [(int) UNARY_PLUS_EXPR].name = "+";
151 
152   assignment_operator_name_info [(int) EXACT_DIV_EXPR].name
153     = "(exact /=)";
154   assignment_operator_name_info [(int) CEIL_DIV_EXPR].name
155     = "(ceiling /=)";
156   assignment_operator_name_info [(int) FLOOR_DIV_EXPR].name
157     = "(floor /=)";
158   assignment_operator_name_info [(int) ROUND_DIV_EXPR].name
159     = "(round /=)";
160   assignment_operator_name_info [(int) CEIL_MOD_EXPR].name
161     = "(ceiling %=)";
162   assignment_operator_name_info [(int) FLOOR_MOD_EXPR].name
163     = "(floor %=)";
164   assignment_operator_name_info [(int) ROUND_MOD_EXPR].name
165     = "(round %=)";
166 }
167 
168 /* Initialize the reserved words.  */
169 
170 void
171 init_reswords (void)
172 {
173   unsigned int i;
174   tree id;
175   int mask = 0;
176 
177   if (cxx_dialect != cxx0x)
178     mask |= D_CXX0X;
179   if (flag_no_asm)
180     mask |= D_ASM | D_EXT;
181   if (flag_no_gnu_keywords)
182     mask |= D_EXT;
183 
184   /* The Objective-C keywords are all context-dependent.  */
185   mask |= D_OBJC;
186 
187   ridpointers = GGC_CNEWVEC (tree, (int) RID_MAX);
188   for (i = 0; i < num_c_common_reswords; i++)
189     {
190       if (c_common_reswords[i].disable & D_CONLY)
191 	continue;
192       id = get_identifier (c_common_reswords[i].word);
193       C_SET_RID_CODE (id, c_common_reswords[i].rid);
194       ridpointers [(int) c_common_reswords[i].rid] = id;
195       if (! (c_common_reswords[i].disable & mask))
196 	C_IS_RESERVED_WORD (id) = 1;
197     }
198 }
199 
200 static void
201 init_cp_pragma (void)
202 {
203   c_register_pragma (0, "vtable", handle_pragma_vtable);
204   c_register_pragma (0, "unit", handle_pragma_unit);
205   c_register_pragma (0, "interface", handle_pragma_interface);
206   c_register_pragma (0, "implementation", handle_pragma_implementation);
207   c_register_pragma ("GCC", "interface", handle_pragma_interface);
208   c_register_pragma ("GCC", "implementation", handle_pragma_implementation);
209   c_register_pragma ("GCC", "java_exceptions", handle_pragma_java_exceptions);
210 }
211 
212 /* TRUE if a code represents a statement.  */
213 
214 bool statement_code_p[MAX_TREE_CODES];
215 
216 /* Initialize the C++ front end.  This function is very sensitive to
217    the exact order that things are done here.  It would be nice if the
218    initialization done by this routine were moved to its subroutines,
219    and the ordering dependencies clarified and reduced.  */
220 bool
221 cxx_init (void)
222 {
223   location_t saved_loc;
224   unsigned int i;
225   static const enum tree_code stmt_codes[] = {
226    CTOR_INITIALIZER,	TRY_BLOCK,	HANDLER,
227    EH_SPEC_BLOCK,	USING_STMT,	TAG_DEFN,
228    IF_STMT,		CLEANUP_STMT,	FOR_STMT,
229    WHILE_STMT,		DO_STMT,	BREAK_STMT,
230    CONTINUE_STMT,	SWITCH_STMT,	EXPR_STMT
231   };
232 
233   memset (&statement_code_p, 0, sizeof (statement_code_p));
234   for (i = 0; i < ARRAY_SIZE (stmt_codes); i++)
235     statement_code_p[stmt_codes[i]] = true;
236 
237   saved_loc = input_location;
238   input_location = BUILTINS_LOCATION;
239 
240   init_reswords ();
241   init_tree ();
242   init_cp_semantics ();
243   init_operators ();
244   init_method ();
245   init_error ();
246 
247   current_function_decl = NULL;
248 
249   class_type_node = ridpointers[(int) RID_CLASS];
250 
251   cxx_init_decl_processing ();
252 
253   if (c_common_init () == false)
254     {
255       input_location = saved_loc;
256       return false;
257     }
258 
259   init_cp_pragma ();
260 
261   init_repo ();
262 
263   input_location = saved_loc;
264   return true;
265 }
266 
267 /* Return nonzero if S is not considered part of an
268    INTERFACE/IMPLEMENTATION pair.  Otherwise, return 0.  */
269 
270 static int
271 interface_strcmp (const char* s)
272 {
273   /* Set the interface/implementation bits for this scope.  */
274   struct impl_files *ifiles;
275   const char *s1;
276 
277   for (ifiles = impl_file_chain; ifiles; ifiles = ifiles->next)
278     {
279       const char *t1 = ifiles->filename;
280       s1 = s;
281 
282       if (*s1 != *t1 || *s1 == 0)
283 	continue;
284 
285       while (*s1 == *t1 && *s1 != 0)
286 	s1++, t1++;
287 
288       /* A match.  */
289       if (*s1 == *t1)
290 	return 0;
291 
292       /* Don't get faked out by xxx.yyy.cc vs xxx.zzz.cc.  */
293       if (strchr (s1, '.') || strchr (t1, '.'))
294 	continue;
295 
296       if (*s1 == '\0' || s1[-1] != '.' || t1[-1] != '.')
297 	continue;
298 
299       /* A match.  */
300       return 0;
301     }
302 
303   /* No matches.  */
304   return 1;
305 }
306 
307 
308 
309 /* Parse a #pragma whose sole argument is a string constant.
310    If OPT is true, the argument is optional.  */
311 static tree
312 parse_strconst_pragma (const char* name, int opt)
313 {
314   tree result, x;
315   enum cpp_ttype t;
316 
317   t = pragma_lex (&result);
318   if (t == CPP_STRING)
319     {
320       if (pragma_lex (&x) != CPP_EOF)
321 	warning (0, "junk at end of #pragma %s", name);
322       return result;
323     }
324 
325   if (t == CPP_EOF && opt)
326     return NULL_TREE;
327 
328   error ("invalid #pragma %s", name);
329   return error_mark_node;
330 }
331 
332 static void
333 handle_pragma_vtable (cpp_reader* dfile ATTRIBUTE_UNUSED )
334 {
335   parse_strconst_pragma ("vtable", 0);
336   sorry ("#pragma vtable no longer supported");
337 }
338 
339 static void
340 handle_pragma_unit (cpp_reader* dfile ATTRIBUTE_UNUSED )
341 {
342   /* Validate syntax, but don't do anything.  */
343   parse_strconst_pragma ("unit", 0);
344 }
345 
346 static void
347 handle_pragma_interface (cpp_reader* dfile ATTRIBUTE_UNUSED )
348 {
349   tree fname = parse_strconst_pragma ("interface", 1);
350   struct c_fileinfo *finfo;
351   const char *filename;
352 
353   if (fname == error_mark_node)
354     return;
355   else if (fname == 0)
356     filename = lbasename (input_filename);
357   else
358     filename = TREE_STRING_POINTER (fname);
359 
360   finfo = get_fileinfo (input_filename);
361 
362   if (impl_file_chain == 0)
363     {
364       /* If this is zero at this point, then we are
365 	 auto-implementing.  */
366       if (main_input_filename == 0)
367 	main_input_filename = input_filename;
368     }
369 
370   finfo->interface_only = interface_strcmp (filename);
371   /* If MULTIPLE_SYMBOL_SPACES is set, we cannot assume that we can see
372      a definition in another file.  */
373   if (!MULTIPLE_SYMBOL_SPACES || !finfo->interface_only)
374     finfo->interface_unknown = 0;
375 }
376 
377 /* Note that we have seen a #pragma implementation for the key MAIN_FILENAME.
378    We used to only allow this at toplevel, but that restriction was buggy
379    in older compilers and it seems reasonable to allow it in the headers
380    themselves, too.  It only needs to precede the matching #p interface.
381 
382    We don't touch finfo->interface_only or finfo->interface_unknown;
383    the user must specify a matching #p interface for this to have
384    any effect.  */
385 
386 static void
387 handle_pragma_implementation (cpp_reader* dfile ATTRIBUTE_UNUSED )
388 {
389   tree fname = parse_strconst_pragma ("implementation", 1);
390   const char *filename;
391   struct impl_files *ifiles = impl_file_chain;
392 
393   if (fname == error_mark_node)
394     return;
395 
396   if (fname == 0)
397     {
398       if (main_input_filename)
399 	filename = main_input_filename;
400       else
401 	filename = input_filename;
402       filename = lbasename (filename);
403     }
404   else
405     {
406       filename = TREE_STRING_POINTER (fname);
407       if (cpp_included_before (parse_in, filename, input_location))
408 	warning (0, "#pragma implementation for %qs appears after "
409 		 "file is included", filename);
410     }
411 
412   for (; ifiles; ifiles = ifiles->next)
413     {
414       if (! strcmp (ifiles->filename, filename))
415 	break;
416     }
417   if (ifiles == 0)
418     {
419       ifiles = XNEW (struct impl_files);
420       ifiles->filename = xstrdup (filename);
421       ifiles->next = impl_file_chain;
422       impl_file_chain = ifiles;
423     }
424 }
425 
426 /* Indicate that this file uses Java-personality exception handling.  */
427 static void
428 handle_pragma_java_exceptions (cpp_reader* dfile ATTRIBUTE_UNUSED)
429 {
430   tree x;
431   if (pragma_lex (&x) != CPP_EOF)
432     warning (0, "junk at end of #pragma GCC java_exceptions");
433 
434   choose_personality_routine (lang_java);
435   pragma_java_exceptions = true;
436 }
437 
438 /* Issue an error message indicating that the lookup of NAME (an
439    IDENTIFIER_NODE) failed.  Returns the ERROR_MARK_NODE.  */
440 
441 tree
442 unqualified_name_lookup_error (tree name)
443 {
444   if (IDENTIFIER_OPNAME_P (name))
445     {
446       if (name != ansi_opname (ERROR_MARK))
447 	error ("%qD not defined", name);
448     }
449   else
450     {
451       error ("%qD was not declared in this scope", name);
452       /* Prevent repeated error messages by creating a VAR_DECL with
453 	 this NAME in the innermost block scope.  */
454       if (current_function_decl)
455 	{
456 	  tree decl;
457 	  decl = build_decl (input_location,
458 			     VAR_DECL, name, error_mark_node);
459 	  DECL_CONTEXT (decl) = current_function_decl;
460 	  push_local_binding (name, decl, 0);
461 	  /* Mark the variable as used so that we do not get warnings
462 	     about it being unused later.  */
463 	  TREE_USED (decl) = 1;
464 	}
465     }
466 
467   return error_mark_node;
468 }
469 
470 /* Like unqualified_name_lookup_error, but NAME is an unqualified-id
471    used as a function.  Returns an appropriate expression for
472    NAME.  */
473 
474 tree
475 unqualified_fn_lookup_error (tree name)
476 {
477   if (processing_template_decl)
478     {
479       /* In a template, it is invalid to write "f()" or "f(3)" if no
480 	 declaration of "f" is available.  Historically, G++ and most
481 	 other compilers accepted that usage since they deferred all name
482 	 lookup until instantiation time rather than doing unqualified
483 	 name lookup at template definition time; explain to the user what
484 	 is going wrong.
485 
486 	 Note that we have the exact wording of the following message in
487 	 the manual (trouble.texi, node "Name lookup"), so they need to
488 	 be kept in synch.  */
489       permerror (input_location, "there are no arguments to %qD that depend on a template "
490 		 "parameter, so a declaration of %qD must be available",
491 		 name, name);
492 
493       if (!flag_permissive)
494 	{
495 	  static bool hint;
496 	  if (!hint)
497 	    {
498 	      inform (input_location, "(if you use %<-fpermissive%>, G++ will accept your "
499 		     "code, but allowing the use of an undeclared name is "
500 		     "deprecated)");
501 	      hint = true;
502 	    }
503 	}
504       return name;
505     }
506 
507   return unqualified_name_lookup_error (name);
508 }
509 
510 tree
511 build_lang_decl (enum tree_code code, tree name, tree type)
512 {
513   tree t;
514 
515   t = build_decl (input_location,
516 		  code, name, type);
517   retrofit_lang_decl (t);
518 
519   return t;
520 }
521 
522 /* Add DECL_LANG_SPECIFIC info to T.  Called from build_lang_decl
523    and pushdecl (for functions generated by the back end).  */
524 
525 void
526 retrofit_lang_decl (tree t)
527 {
528   struct lang_decl *ld;
529   size_t size;
530   int sel;
531 
532   if (TREE_CODE (t) == FUNCTION_DECL)
533     sel = 1, size = sizeof (struct lang_decl_fn);
534   else if (TREE_CODE (t) == NAMESPACE_DECL)
535     sel = 2, size = sizeof (struct lang_decl_ns);
536   else if (TREE_CODE (t) == PARM_DECL)
537     sel = 3, size = sizeof (struct lang_decl_parm);
538   else if (LANG_DECL_HAS_MIN (t))
539     sel = 0, size = sizeof (struct lang_decl_min);
540   else
541     gcc_unreachable ();
542 
543   ld = GGC_CNEWVAR (struct lang_decl, size);
544 
545   ld->u.base.selector = sel;
546 
547   DECL_LANG_SPECIFIC (t) = ld;
548   if (current_lang_name == lang_name_cplusplus
549       || decl_linkage (t) == lk_none)
550     SET_DECL_LANGUAGE (t, lang_cplusplus);
551   else if (current_lang_name == lang_name_c)
552     SET_DECL_LANGUAGE (t, lang_c);
553   else if (current_lang_name == lang_name_java)
554     SET_DECL_LANGUAGE (t, lang_java);
555   else
556     gcc_unreachable ();
557 
558 #ifdef GATHER_STATISTICS
559   tree_node_counts[(int)lang_decl] += 1;
560   tree_node_sizes[(int)lang_decl] += size;
561 #endif
562 }
563 
564 void
565 cxx_dup_lang_specific_decl (tree node)
566 {
567   int size;
568   struct lang_decl *ld;
569 
570   if (! DECL_LANG_SPECIFIC (node))
571     return;
572 
573   if (TREE_CODE (node) == FUNCTION_DECL)
574     size = sizeof (struct lang_decl_fn);
575   else if (TREE_CODE (node) == NAMESPACE_DECL)
576     size = sizeof (struct lang_decl_ns);
577   else if (TREE_CODE (node) == PARM_DECL)
578     size = sizeof (struct lang_decl_parm);
579   else if (LANG_DECL_HAS_MIN (node))
580     size = sizeof (struct lang_decl_min);
581   else
582     gcc_unreachable ();
583 
584   ld = GGC_NEWVAR (struct lang_decl, size);
585   memcpy (ld, DECL_LANG_SPECIFIC (node), size);
586   DECL_LANG_SPECIFIC (node) = ld;
587 
588 #ifdef GATHER_STATISTICS
589   tree_node_counts[(int)lang_decl] += 1;
590   tree_node_sizes[(int)lang_decl] += size;
591 #endif
592 }
593 
594 /* Copy DECL, including any language-specific parts.  */
595 
596 tree
597 copy_decl (tree decl)
598 {
599   tree copy;
600 
601   copy = copy_node (decl);
602   cxx_dup_lang_specific_decl (copy);
603   return copy;
604 }
605 
606 /* Replace the shared language-specific parts of NODE with a new copy.  */
607 
608 static void
609 copy_lang_type (tree node)
610 {
611   int size;
612   struct lang_type *lt;
613 
614   if (! TYPE_LANG_SPECIFIC (node))
615     return;
616 
617   if (TYPE_LANG_SPECIFIC (node)->u.h.is_lang_type_class)
618     size = sizeof (struct lang_type);
619   else
620     size = sizeof (struct lang_type_ptrmem);
621   lt = GGC_NEWVAR (struct lang_type, size);
622   memcpy (lt, TYPE_LANG_SPECIFIC (node), size);
623   TYPE_LANG_SPECIFIC (node) = lt;
624 
625 #ifdef GATHER_STATISTICS
626   tree_node_counts[(int)lang_type] += 1;
627   tree_node_sizes[(int)lang_type] += size;
628 #endif
629 }
630 
631 /* Copy TYPE, including any language-specific parts.  */
632 
633 tree
634 copy_type (tree type)
635 {
636   tree copy;
637 
638   copy = copy_node (type);
639   copy_lang_type (copy);
640   return copy;
641 }
642 
643 tree
644 cxx_make_type (enum tree_code code)
645 {
646   tree t = make_node (code);
647 
648   /* Create lang_type structure.  */
649   if (RECORD_OR_UNION_CODE_P (code)
650       || code == BOUND_TEMPLATE_TEMPLATE_PARM)
651     {
652       struct lang_type *pi = GGC_CNEW (struct lang_type);
653 
654       TYPE_LANG_SPECIFIC (t) = pi;
655       pi->u.c.h.is_lang_type_class = 1;
656 
657 #ifdef GATHER_STATISTICS
658       tree_node_counts[(int)lang_type] += 1;
659       tree_node_sizes[(int)lang_type] += sizeof (struct lang_type);
660 #endif
661     }
662 
663   /* Set up some flags that give proper default behavior.  */
664   if (RECORD_OR_UNION_CODE_P (code))
665     {
666       struct c_fileinfo *finfo = get_fileinfo (input_filename);
667       SET_CLASSTYPE_INTERFACE_UNKNOWN_X (t, finfo->interface_unknown);
668       CLASSTYPE_INTERFACE_ONLY (t) = finfo->interface_only;
669     }
670 
671   return t;
672 }
673 
674 tree
675 make_class_type (enum tree_code code)
676 {
677   tree t = cxx_make_type (code);
678   SET_CLASS_TYPE_P (t, 1);
679   return t;
680 }
681 
682 /* Returns true if we are currently in the main source file, or in a
683    template instantiation started from the main source file.  */
684 
685 bool
686 in_main_input_context (void)
687 {
688   struct tinst_level *tl = outermost_tinst_level();
689 
690   if (tl)
691     return strcmp (main_input_filename,
692                   LOCATION_FILE (tl->locus)) == 0;
693   else
694     return strcmp (main_input_filename, input_filename) == 0;
695 }
696