xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/cp/tree.c (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /* Language-dependent node constructors for parse phase of GNU compiler.
2    Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3    1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009
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 #include "config.h"
24 #include "system.h"
25 #include "coretypes.h"
26 #include "tm.h"
27 #include "tree.h"
28 #include "cp-tree.h"
29 #include "flags.h"
30 #include "real.h"
31 #include "rtl.h"
32 #include "toplev.h"
33 #include "insn-config.h"
34 #include "integrate.h"
35 #include "tree-inline.h"
36 #include "debug.h"
37 #include "target.h"
38 #include "convert.h"
39 #include "tree-flow.h"
40 #include "cgraph.h"
41 
42 static tree bot_manip (tree *, int *, void *);
43 static tree bot_replace (tree *, int *, void *);
44 static int list_hash_eq (const void *, const void *);
45 static hashval_t list_hash_pieces (tree, tree, tree);
46 static hashval_t list_hash (const void *);
47 static cp_lvalue_kind lvalue_p_1 (const_tree);
48 static tree build_target_expr (tree, tree);
49 static tree count_trees_r (tree *, int *, void *);
50 static tree verify_stmt_tree_r (tree *, int *, void *);
51 static tree build_local_temp (tree);
52 
53 static tree handle_java_interface_attribute (tree *, tree, tree, int, bool *);
54 static tree handle_com_interface_attribute (tree *, tree, tree, int, bool *);
55 static tree handle_init_priority_attribute (tree *, tree, tree, int, bool *);
56 
57 /* If REF is an lvalue, returns the kind of lvalue that REF is.
58    Otherwise, returns clk_none.  */
59 
60 static cp_lvalue_kind
61 lvalue_p_1 (const_tree ref)
62 {
63   cp_lvalue_kind op1_lvalue_kind = clk_none;
64   cp_lvalue_kind op2_lvalue_kind = clk_none;
65 
66   /* Expressions of reference type are sometimes wrapped in
67      INDIRECT_REFs.  INDIRECT_REFs are just internal compiler
68      representation, not part of the language, so we have to look
69      through them.  */
70   if (TREE_CODE (ref) == INDIRECT_REF
71       && TREE_CODE (TREE_TYPE (TREE_OPERAND (ref, 0)))
72 	  == REFERENCE_TYPE)
73     return lvalue_p_1 (TREE_OPERAND (ref, 0));
74 
75   if (TREE_TYPE (ref)
76       && TREE_CODE (TREE_TYPE (ref)) == REFERENCE_TYPE)
77     {
78       /* unnamed rvalue references are rvalues */
79       if (TYPE_REF_IS_RVALUE (TREE_TYPE (ref))
80 	  && TREE_CODE (ref) != PARM_DECL
81 	  && TREE_CODE (ref) != VAR_DECL
82 	  && TREE_CODE (ref) != COMPONENT_REF)
83 	return clk_rvalueref;
84 
85       /* lvalue references and named rvalue references are lvalues.  */
86       return clk_ordinary;
87     }
88 
89   if (ref == current_class_ptr)
90     return clk_none;
91 
92   switch (TREE_CODE (ref))
93     {
94     case SAVE_EXPR:
95       return clk_none;
96       /* preincrements and predecrements are valid lvals, provided
97 	 what they refer to are valid lvals.  */
98     case PREINCREMENT_EXPR:
99     case PREDECREMENT_EXPR:
100     case TRY_CATCH_EXPR:
101     case WITH_CLEANUP_EXPR:
102     case REALPART_EXPR:
103     case IMAGPART_EXPR:
104       return lvalue_p_1 (TREE_OPERAND (ref, 0));
105 
106     case COMPONENT_REF:
107       op1_lvalue_kind = lvalue_p_1 (TREE_OPERAND (ref, 0));
108       /* Look at the member designator.  */
109       if (!op1_lvalue_kind)
110 	;
111       else if (is_overloaded_fn (TREE_OPERAND (ref, 1)))
112 	/* The "field" can be a FUNCTION_DECL or an OVERLOAD in some
113 	   situations.  If we're seeing a COMPONENT_REF, it's a non-static
114 	   member, so it isn't an lvalue. */
115 	op1_lvalue_kind = clk_none;
116       else if (TREE_CODE (TREE_OPERAND (ref, 1)) != FIELD_DECL)
117 	/* This can be IDENTIFIER_NODE in a template.  */;
118       else if (DECL_C_BIT_FIELD (TREE_OPERAND (ref, 1)))
119 	{
120 	  /* Clear the ordinary bit.  If this object was a class
121 	     rvalue we want to preserve that information.  */
122 	  op1_lvalue_kind &= ~clk_ordinary;
123 	  /* The lvalue is for a bitfield.  */
124 	  op1_lvalue_kind |= clk_bitfield;
125 	}
126       else if (DECL_PACKED (TREE_OPERAND (ref, 1)))
127 	op1_lvalue_kind |= clk_packed;
128 
129       return op1_lvalue_kind;
130 
131     case STRING_CST:
132     case COMPOUND_LITERAL_EXPR:
133       return clk_ordinary;
134 
135     case CONST_DECL:
136       /* CONST_DECL without TREE_STATIC are enumeration values and
137 	 thus not lvalues.  With TREE_STATIC they are used by ObjC++
138 	 in objc_build_string_object and need to be considered as
139 	 lvalues.  */
140       if (! TREE_STATIC (ref))
141 	return clk_none;
142     case VAR_DECL:
143       if (TREE_READONLY (ref) && ! TREE_STATIC (ref)
144 	  && DECL_LANG_SPECIFIC (ref)
145 	  && DECL_IN_AGGR_P (ref))
146 	return clk_none;
147     case INDIRECT_REF:
148     case ARRAY_REF:
149     case PARM_DECL:
150     case RESULT_DECL:
151       if (TREE_CODE (TREE_TYPE (ref)) != METHOD_TYPE)
152 	return clk_ordinary;
153       break;
154 
155       /* A scope ref in a template, left as SCOPE_REF to support later
156 	 access checking.  */
157     case SCOPE_REF:
158       gcc_assert (!type_dependent_expression_p (CONST_CAST_TREE(ref)));
159       return lvalue_p_1 (TREE_OPERAND (ref, 1));
160 
161     case MAX_EXPR:
162     case MIN_EXPR:
163       /* Disallow <? and >? as lvalues if either argument side-effects.  */
164       if (TREE_SIDE_EFFECTS (TREE_OPERAND (ref, 0))
165 	  || TREE_SIDE_EFFECTS (TREE_OPERAND (ref, 1)))
166 	return clk_none;
167       op1_lvalue_kind = lvalue_p_1 (TREE_OPERAND (ref, 0));
168       op2_lvalue_kind = lvalue_p_1 (TREE_OPERAND (ref, 1));
169       break;
170 
171     case COND_EXPR:
172       op1_lvalue_kind = lvalue_p_1 (TREE_OPERAND (ref, 1)
173 				    ? TREE_OPERAND (ref, 1)
174 				    : TREE_OPERAND (ref, 0));
175       op2_lvalue_kind = lvalue_p_1 (TREE_OPERAND (ref, 2));
176       break;
177 
178     case MODIFY_EXPR:
179       return clk_ordinary;
180 
181     case COMPOUND_EXPR:
182       return lvalue_p_1 (TREE_OPERAND (ref, 1));
183 
184     case TARGET_EXPR:
185       return clk_class;
186 
187     case VA_ARG_EXPR:
188       return (CLASS_TYPE_P (TREE_TYPE (ref)) ? clk_class : clk_none);
189 
190     case CALL_EXPR:
191       /* Any class-valued call would be wrapped in a TARGET_EXPR.  */
192       return clk_none;
193 
194     case FUNCTION_DECL:
195       /* All functions (except non-static-member functions) are
196 	 lvalues.  */
197       return (DECL_NONSTATIC_MEMBER_FUNCTION_P (ref)
198 	      ? clk_none : clk_ordinary);
199 
200     case BASELINK:
201       /* We now represent a reference to a single static member function
202 	 with a BASELINK.  */
203       /* This CONST_CAST is okay because BASELINK_FUNCTIONS returns
204 	 its argument unmodified and we assign it to a const_tree.  */
205       return lvalue_p_1 (BASELINK_FUNCTIONS (CONST_CAST_TREE (ref)));
206 
207     case NON_DEPENDENT_EXPR:
208       /* We must consider NON_DEPENDENT_EXPRs to be lvalues so that
209 	 things like "&E" where "E" is an expression with a
210 	 non-dependent type work. It is safe to be lenient because an
211 	 error will be issued when the template is instantiated if "E"
212 	 is not an lvalue.  */
213       return clk_ordinary;
214 
215     default:
216       break;
217     }
218 
219   /* If one operand is not an lvalue at all, then this expression is
220      not an lvalue.  */
221   if (!op1_lvalue_kind || !op2_lvalue_kind)
222     return clk_none;
223 
224   /* Otherwise, it's an lvalue, and it has all the odd properties
225      contributed by either operand.  */
226   op1_lvalue_kind = op1_lvalue_kind | op2_lvalue_kind;
227   /* It's not an ordinary lvalue if it involves any other kind.  */
228   if ((op1_lvalue_kind & ~clk_ordinary) != clk_none)
229     op1_lvalue_kind &= ~clk_ordinary;
230   /* It can't be both a pseudo-lvalue and a non-addressable lvalue.
231      A COND_EXPR of those should be wrapped in a TARGET_EXPR.  */
232   if ((op1_lvalue_kind & (clk_rvalueref|clk_class))
233       && (op1_lvalue_kind & (clk_bitfield|clk_packed)))
234     op1_lvalue_kind = clk_none;
235   return op1_lvalue_kind;
236 }
237 
238 /* Returns the kind of lvalue that REF is, in the sense of
239    [basic.lval].  This function should really be named lvalue_p; it
240    computes the C++ definition of lvalue.  */
241 
242 cp_lvalue_kind
243 real_lvalue_p (tree ref)
244 {
245   cp_lvalue_kind kind = lvalue_p_1 (ref);
246   if (kind & (clk_rvalueref|clk_class))
247     return clk_none;
248   else
249     return kind;
250 }
251 
252 /* This differs from real_lvalue_p in that class rvalues are considered
253    lvalues.  */
254 
255 bool
256 lvalue_p (const_tree ref)
257 {
258   return (lvalue_p_1 (ref) != clk_none);
259 }
260 
261 /* This differs from real_lvalue_p in that rvalues formed by dereferencing
262    rvalue references are considered rvalues.  */
263 
264 bool
265 lvalue_or_rvalue_with_address_p (const_tree ref)
266 {
267   cp_lvalue_kind kind = lvalue_p_1 (ref);
268   if (kind & clk_class)
269     return false;
270   else
271     return (kind != clk_none);
272 }
273 
274 /* Test whether DECL is a builtin that may appear in a
275    constant-expression. */
276 
277 bool
278 builtin_valid_in_constant_expr_p (const_tree decl)
279 {
280   /* At present BUILT_IN_CONSTANT_P is the only builtin we're allowing
281      in constant-expressions.  We may want to add other builtins later. */
282   return DECL_IS_BUILTIN_CONSTANT_P (decl);
283 }
284 
285 /* Build a TARGET_EXPR, initializing the DECL with the VALUE.  */
286 
287 static tree
288 build_target_expr (tree decl, tree value)
289 {
290   tree t;
291 
292 #ifdef ENABLE_CHECKING
293   gcc_assert (VOID_TYPE_P (TREE_TYPE (value))
294 	      || TREE_TYPE (decl) == TREE_TYPE (value)
295 	      || useless_type_conversion_p (TREE_TYPE (decl),
296 					    TREE_TYPE (value)));
297 #endif
298 
299   t = build4 (TARGET_EXPR, TREE_TYPE (decl), decl, value,
300 	      cxx_maybe_build_cleanup (decl), NULL_TREE);
301   /* We always set TREE_SIDE_EFFECTS so that expand_expr does not
302      ignore the TARGET_EXPR.  If there really turn out to be no
303      side-effects, then the optimizer should be able to get rid of
304      whatever code is generated anyhow.  */
305   TREE_SIDE_EFFECTS (t) = 1;
306 
307   return t;
308 }
309 
310 /* Return an undeclared local temporary of type TYPE for use in building a
311    TARGET_EXPR.  */
312 
313 static tree
314 build_local_temp (tree type)
315 {
316   tree slot = build_decl (input_location,
317 			  VAR_DECL, NULL_TREE, type);
318   DECL_ARTIFICIAL (slot) = 1;
319   DECL_IGNORED_P (slot) = 1;
320   DECL_CONTEXT (slot) = current_function_decl;
321   layout_decl (slot, 0);
322   return slot;
323 }
324 
325 /* Set various status flags when building an AGGR_INIT_EXPR object T.  */
326 
327 static void
328 process_aggr_init_operands (tree t)
329 {
330   bool side_effects;
331 
332   side_effects = TREE_SIDE_EFFECTS (t);
333   if (!side_effects)
334     {
335       int i, n;
336       n = TREE_OPERAND_LENGTH (t);
337       for (i = 1; i < n; i++)
338 	{
339 	  tree op = TREE_OPERAND (t, i);
340 	  if (op && TREE_SIDE_EFFECTS (op))
341 	    {
342 	      side_effects = 1;
343 	      break;
344 	    }
345 	}
346     }
347   TREE_SIDE_EFFECTS (t) = side_effects;
348 }
349 
350 /* Build an AGGR_INIT_EXPR of class tcc_vl_exp with the indicated RETURN_TYPE,
351    FN, and SLOT.  NARGS is the number of call arguments which are specified
352    as a tree array ARGS.  */
353 
354 static tree
355 build_aggr_init_array (tree return_type, tree fn, tree slot, int nargs,
356 		       tree *args)
357 {
358   tree t;
359   int i;
360 
361   t = build_vl_exp (AGGR_INIT_EXPR, nargs + 3);
362   TREE_TYPE (t) = return_type;
363   AGGR_INIT_EXPR_FN (t) = fn;
364   AGGR_INIT_EXPR_SLOT (t) = slot;
365   for (i = 0; i < nargs; i++)
366     AGGR_INIT_EXPR_ARG (t, i) = args[i];
367   process_aggr_init_operands (t);
368   return t;
369 }
370 
371 /* INIT is a CALL_EXPR or AGGR_INIT_EXPR which needs info about its
372    target.  TYPE is the type to be initialized.
373 
374    Build an AGGR_INIT_EXPR to represent the initialization.  This function
375    differs from build_cplus_new in that an AGGR_INIT_EXPR can only be used
376    to initialize another object, whereas a TARGET_EXPR can either
377    initialize another object or create its own temporary object, and as a
378    result building up a TARGET_EXPR requires that the type's destructor be
379    callable.  */
380 
381 tree
382 build_aggr_init_expr (tree type, tree init)
383 {
384   tree fn;
385   tree slot;
386   tree rval;
387   int is_ctor;
388 
389   /* Make sure that we're not trying to create an instance of an
390      abstract class.  */
391   abstract_virtuals_error (NULL_TREE, type);
392 
393   if (TREE_CODE (init) == CALL_EXPR)
394     fn = CALL_EXPR_FN (init);
395   else if (TREE_CODE (init) == AGGR_INIT_EXPR)
396     fn = AGGR_INIT_EXPR_FN (init);
397   else
398     return convert (type, init);
399 
400   is_ctor = (TREE_CODE (fn) == ADDR_EXPR
401 	     && TREE_CODE (TREE_OPERAND (fn, 0)) == FUNCTION_DECL
402 	     && DECL_CONSTRUCTOR_P (TREE_OPERAND (fn, 0)));
403 
404   /* We split the CALL_EXPR into its function and its arguments here.
405      Then, in expand_expr, we put them back together.  The reason for
406      this is that this expression might be a default argument
407      expression.  In that case, we need a new temporary every time the
408      expression is used.  That's what break_out_target_exprs does; it
409      replaces every AGGR_INIT_EXPR with a copy that uses a fresh
410      temporary slot.  Then, expand_expr builds up a call-expression
411      using the new slot.  */
412 
413   /* If we don't need to use a constructor to create an object of this
414      type, don't mess with AGGR_INIT_EXPR.  */
415   if (is_ctor || TREE_ADDRESSABLE (type))
416     {
417       slot = build_local_temp (type);
418 
419       if (TREE_CODE(init) == CALL_EXPR)
420 	rval = build_aggr_init_array (void_type_node, fn, slot,
421 				      call_expr_nargs (init),
422 				      CALL_EXPR_ARGP (init));
423       else
424 	rval = build_aggr_init_array (void_type_node, fn, slot,
425 				      aggr_init_expr_nargs (init),
426 				      AGGR_INIT_EXPR_ARGP (init));
427       TREE_SIDE_EFFECTS (rval) = 1;
428       AGGR_INIT_VIA_CTOR_P (rval) = is_ctor;
429     }
430   else
431     rval = init;
432 
433   return rval;
434 }
435 
436 /* INIT is a CALL_EXPR or AGGR_INIT_EXPR which needs info about its
437    target.  TYPE is the type that this initialization should appear to
438    have.
439 
440    Build an encapsulation of the initialization to perform
441    and return it so that it can be processed by language-independent
442    and language-specific expression expanders.  */
443 
444 tree
445 build_cplus_new (tree type, tree init)
446 {
447   tree rval = build_aggr_init_expr (type, init);
448   tree slot;
449 
450   if (TREE_CODE (rval) == AGGR_INIT_EXPR)
451     slot = AGGR_INIT_EXPR_SLOT (rval);
452   else if (TREE_CODE (rval) == CALL_EXPR)
453     slot = build_local_temp (type);
454   else
455     return rval;
456 
457   rval = build_target_expr (slot, rval);
458   TARGET_EXPR_IMPLICIT_P (rval) = 1;
459 
460   return rval;
461 }
462 
463 /* Return a TARGET_EXPR which expresses the direct-initialization of one
464    array from another.  */
465 
466 tree
467 build_array_copy (tree init)
468 {
469   tree type = TREE_TYPE (init);
470   tree slot = build_local_temp (type);
471   init = build2 (VEC_INIT_EXPR, type, slot, init);
472   SET_EXPR_LOCATION (init, input_location);
473   init = build_target_expr (slot, init);
474   TARGET_EXPR_IMPLICIT_P (init) = 1;
475 
476   return init;
477 }
478 
479 /* Build a TARGET_EXPR using INIT to initialize a new temporary of the
480    indicated TYPE.  */
481 
482 tree
483 build_target_expr_with_type (tree init, tree type)
484 {
485   gcc_assert (!VOID_TYPE_P (type));
486 
487   if (TREE_CODE (init) == TARGET_EXPR)
488     return init;
489   else if (CLASS_TYPE_P (type) && !TYPE_HAS_TRIVIAL_INIT_REF (type)
490 	   && !VOID_TYPE_P (TREE_TYPE (init))
491 	   && TREE_CODE (init) != COND_EXPR
492 	   && TREE_CODE (init) != CONSTRUCTOR
493 	   && TREE_CODE (init) != VA_ARG_EXPR)
494     /* We need to build up a copy constructor call.  A void initializer
495        means we're being called from bot_manip.  COND_EXPR is a special
496        case because we already have copies on the arms and we don't want
497        another one here.  A CONSTRUCTOR is aggregate initialization, which
498        is handled separately.  A VA_ARG_EXPR is magic creation of an
499        aggregate; there's no additional work to be done.  */
500     return force_rvalue (init);
501 
502   return force_target_expr (type, init);
503 }
504 
505 /* Like the above function, but without the checking.  This function should
506    only be used by code which is deliberately trying to subvert the type
507    system, such as call_builtin_trap.  */
508 
509 tree
510 force_target_expr (tree type, tree init)
511 {
512   tree slot;
513 
514   gcc_assert (!VOID_TYPE_P (type));
515 
516   slot = build_local_temp (type);
517   return build_target_expr (slot, init);
518 }
519 
520 /* Like build_target_expr_with_type, but use the type of INIT.  */
521 
522 tree
523 get_target_expr (tree init)
524 {
525   if (TREE_CODE (init) == AGGR_INIT_EXPR)
526     return build_target_expr (AGGR_INIT_EXPR_SLOT (init), init);
527   else
528     return build_target_expr_with_type (init, TREE_TYPE (init));
529 }
530 
531 /* If EXPR is a bitfield reference, convert it to the declared type of
532    the bitfield, and return the resulting expression.  Otherwise,
533    return EXPR itself.  */
534 
535 tree
536 convert_bitfield_to_declared_type (tree expr)
537 {
538   tree bitfield_type;
539 
540   bitfield_type = is_bitfield_expr_with_lowered_type (expr);
541   if (bitfield_type)
542     expr = convert_to_integer (TYPE_MAIN_VARIANT (bitfield_type),
543 			       expr);
544   return expr;
545 }
546 
547 /* EXPR is being used in an rvalue context.  Return a version of EXPR
548    that is marked as an rvalue.  */
549 
550 tree
551 rvalue (tree expr)
552 {
553   tree type;
554 
555   if (error_operand_p (expr))
556     return expr;
557 
558   /* [basic.lval]
559 
560      Non-class rvalues always have cv-unqualified types.  */
561   type = TREE_TYPE (expr);
562   if (!CLASS_TYPE_P (type) && cv_qualified_p (type))
563     type = cv_unqualified (type);
564 
565   /* We need to do this for rvalue refs as well to get the right answer
566      from decltype; see c++/36628.  */
567   if (!processing_template_decl && lvalue_or_rvalue_with_address_p (expr))
568     expr = build1 (NON_LVALUE_EXPR, type, expr);
569   else if (type != TREE_TYPE (expr))
570     expr = build_nop (type, expr);
571 
572   return expr;
573 }
574 
575 
576 /* Hash an ARRAY_TYPE.  K is really of type `tree'.  */
577 
578 static hashval_t
579 cplus_array_hash (const void* k)
580 {
581   hashval_t hash;
582   const_tree const t = (const_tree) k;
583 
584   hash = TYPE_UID (TREE_TYPE (t));
585   if (TYPE_DOMAIN (t))
586     hash ^= TYPE_UID (TYPE_DOMAIN (t));
587   return hash;
588 }
589 
590 typedef struct cplus_array_info {
591   tree type;
592   tree domain;
593 } cplus_array_info;
594 
595 /* Compare two ARRAY_TYPEs.  K1 is really of type `tree', K2 is really
596    of type `cplus_array_info*'. */
597 
598 static int
599 cplus_array_compare (const void * k1, const void * k2)
600 {
601   const_tree const t1 = (const_tree) k1;
602   const cplus_array_info *const t2 = (const cplus_array_info*) k2;
603 
604   return (TREE_TYPE (t1) == t2->type && TYPE_DOMAIN (t1) == t2->domain);
605 }
606 
607 /* Hash table containing dependent array types, which are unsuitable for
608    the language-independent type hash table.  */
609 static GTY ((param_is (union tree_node))) htab_t cplus_array_htab;
610 
611 /* Like build_array_type, but handle special C++ semantics.  */
612 
613 tree
614 build_cplus_array_type (tree elt_type, tree index_type)
615 {
616   tree t;
617 
618   if (elt_type == error_mark_node || index_type == error_mark_node)
619     return error_mark_node;
620 
621   if (processing_template_decl
622       && (dependent_type_p (elt_type)
623 	  || (index_type && !TREE_CONSTANT (TYPE_MAX_VALUE (index_type)))))
624     {
625       void **e;
626       cplus_array_info cai;
627       hashval_t hash;
628 
629       if (cplus_array_htab == NULL)
630 	cplus_array_htab = htab_create_ggc (61, &cplus_array_hash,
631 					    &cplus_array_compare, NULL);
632 
633       hash = TYPE_UID (elt_type);
634       if (index_type)
635 	hash ^= TYPE_UID (index_type);
636       cai.type = elt_type;
637       cai.domain = index_type;
638 
639       e = htab_find_slot_with_hash (cplus_array_htab, &cai, hash, INSERT);
640       if (*e)
641 	/* We have found the type: we're done.  */
642 	return (tree) *e;
643       else
644 	{
645 	  /* Build a new array type.  */
646 	  t = cxx_make_type (ARRAY_TYPE);
647 	  TREE_TYPE (t) = elt_type;
648 	  TYPE_DOMAIN (t) = index_type;
649 
650 	  /* Store it in the hash table. */
651 	  *e = t;
652 
653 	  /* Set the canonical type for this new node.  */
654 	  if (TYPE_STRUCTURAL_EQUALITY_P (elt_type)
655 	      || (index_type && TYPE_STRUCTURAL_EQUALITY_P (index_type)))
656 	    SET_TYPE_STRUCTURAL_EQUALITY (t);
657 	  else if (TYPE_CANONICAL (elt_type) != elt_type
658 		   || (index_type
659 		       && TYPE_CANONICAL (index_type) != index_type))
660 	    TYPE_CANONICAL (t)
661 		= build_cplus_array_type
662 		   (TYPE_CANONICAL (elt_type),
663 		    index_type ? TYPE_CANONICAL (index_type) : index_type);
664 	  else
665 	    TYPE_CANONICAL (t) = t;
666 	}
667     }
668   else
669     t = build_array_type (elt_type, index_type);
670 
671   /* We want TYPE_MAIN_VARIANT of an array to strip cv-quals from the
672      element type as well, so fix it up if needed.  */
673   if (elt_type != TYPE_MAIN_VARIANT (elt_type))
674     {
675       tree m = build_cplus_array_type (TYPE_MAIN_VARIANT (elt_type),
676 				       index_type);
677       if (TYPE_MAIN_VARIANT (t) != m)
678 	{
679 	  TYPE_MAIN_VARIANT (t) = m;
680 	  TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
681 	  TYPE_NEXT_VARIANT (m) = t;
682 	}
683     }
684 
685   /* Push these needs up so that initialization takes place
686      more easily.  */
687   TYPE_NEEDS_CONSTRUCTING (t)
688     = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (elt_type));
689   TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
690     = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (elt_type));
691   return t;
692 }
693 
694 /* Return an ARRAY_TYPE with element type ELT and length N.  */
695 
696 tree
697 build_array_of_n_type (tree elt, int n)
698 {
699   return build_cplus_array_type (elt, build_index_type (size_int (n - 1)));
700 }
701 
702 /* Return a reference type node referring to TO_TYPE.  If RVAL is
703    true, return an rvalue reference type, otherwise return an lvalue
704    reference type.  If a type node exists, reuse it, otherwise create
705    a new one.  */
706 tree
707 cp_build_reference_type (tree to_type, bool rval)
708 {
709   tree lvalue_ref, t;
710   lvalue_ref = build_reference_type (to_type);
711   if (!rval)
712     return lvalue_ref;
713 
714   /* This code to create rvalue reference types is based on and tied
715      to the code creating lvalue reference types in the middle-end
716      functions build_reference_type_for_mode and build_reference_type.
717 
718      It works by putting the rvalue reference type nodes after the
719      lvalue reference nodes in the TYPE_NEXT_REF_TO linked list, so
720      they will effectively be ignored by the middle end.  */
721 
722   for (t = lvalue_ref; (t = TYPE_NEXT_REF_TO (t)); )
723     if (TYPE_REF_IS_RVALUE (t))
724       return t;
725 
726   t = build_distinct_type_copy (lvalue_ref);
727 
728   TYPE_REF_IS_RVALUE (t) = true;
729   TYPE_NEXT_REF_TO (t) = TYPE_NEXT_REF_TO (lvalue_ref);
730   TYPE_NEXT_REF_TO (lvalue_ref) = t;
731 
732   if (TYPE_STRUCTURAL_EQUALITY_P (to_type))
733     SET_TYPE_STRUCTURAL_EQUALITY (t);
734   else if (TYPE_CANONICAL (to_type) != to_type)
735     TYPE_CANONICAL (t)
736       = cp_build_reference_type (TYPE_CANONICAL (to_type), rval);
737   else
738     TYPE_CANONICAL (t) = t;
739 
740   layout_type (t);
741 
742   return t;
743 
744 }
745 
746 /* Returns EXPR cast to rvalue reference type, like std::move.  */
747 
748 tree
749 move (tree expr)
750 {
751   tree type = TREE_TYPE (expr);
752   gcc_assert (TREE_CODE (type) != REFERENCE_TYPE);
753   type = cp_build_reference_type (type, /*rval*/true);
754   return build_static_cast (type, expr, tf_warning_or_error);
755 }
756 
757 /* Used by the C++ front end to build qualified array types.  However,
758    the C version of this function does not properly maintain canonical
759    types (which are not used in C).  */
760 tree
761 c_build_qualified_type (tree type, int type_quals)
762 {
763   return cp_build_qualified_type (type, type_quals);
764 }
765 
766 
767 /* Make a variant of TYPE, qualified with the TYPE_QUALS.  Handles
768    arrays correctly.  In particular, if TYPE is an array of T's, and
769    TYPE_QUALS is non-empty, returns an array of qualified T's.
770 
771    FLAGS determines how to deal with ill-formed qualifications. If
772    tf_ignore_bad_quals is set, then bad qualifications are dropped
773    (this is permitted if TYPE was introduced via a typedef or template
774    type parameter). If bad qualifications are dropped and tf_warning
775    is set, then a warning is issued for non-const qualifications.  If
776    tf_ignore_bad_quals is not set and tf_error is not set, we
777    return error_mark_node. Otherwise, we issue an error, and ignore
778    the qualifications.
779 
780    Qualification of a reference type is valid when the reference came
781    via a typedef or template type argument. [dcl.ref] No such
782    dispensation is provided for qualifying a function type.  [dcl.fct]
783    DR 295 queries this and the proposed resolution brings it into line
784    with qualifying a reference.  We implement the DR.  We also behave
785    in a similar manner for restricting non-pointer types.  */
786 
787 tree
788 cp_build_qualified_type_real (tree type,
789 			      int type_quals,
790 			      tsubst_flags_t complain)
791 {
792   tree result;
793   int bad_quals = TYPE_UNQUALIFIED;
794 
795   if (type == error_mark_node)
796     return type;
797 
798   if (type_quals == cp_type_quals (type))
799     return type;
800 
801   if (TREE_CODE (type) == ARRAY_TYPE)
802     {
803       /* In C++, the qualification really applies to the array element
804 	 type.  Obtain the appropriately qualified element type.  */
805       tree t;
806       tree element_type
807 	= cp_build_qualified_type_real (TREE_TYPE (type),
808 					type_quals,
809 					complain);
810 
811       if (element_type == error_mark_node)
812 	return error_mark_node;
813 
814       /* See if we already have an identically qualified type.  Tests
815 	 should be equivalent to those in check_qualified_type.  */
816       for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
817 	if (TREE_TYPE (t) == element_type
818 	    && TYPE_NAME (t) == TYPE_NAME (type)
819 	    && TYPE_CONTEXT (t) == TYPE_CONTEXT (type)
820 	    && attribute_list_equal (TYPE_ATTRIBUTES (t),
821 				     TYPE_ATTRIBUTES (type)))
822 	  break;
823 
824       if (!t)
825 	{
826 	  t = build_cplus_array_type (element_type, TYPE_DOMAIN (type));
827 
828 	  /* Keep the typedef name.  */
829 	  if (TYPE_NAME (t) != TYPE_NAME (type))
830 	    {
831 	      t = build_variant_type_copy (t);
832 	      TYPE_NAME (t) = TYPE_NAME (type);
833 	    }
834 	}
835 
836       /* Even if we already had this variant, we update
837 	 TYPE_NEEDS_CONSTRUCTING and TYPE_HAS_NONTRIVIAL_DESTRUCTOR in case
838 	 they changed since the variant was originally created.
839 
840 	 This seems hokey; if there is some way to use a previous
841 	 variant *without* coming through here,
842 	 TYPE_NEEDS_CONSTRUCTING will never be updated.  */
843       TYPE_NEEDS_CONSTRUCTING (t)
844 	= TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (element_type));
845       TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
846 	= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (element_type));
847       return t;
848     }
849   else if (TYPE_PTRMEMFUNC_P (type))
850     {
851       /* For a pointer-to-member type, we can't just return a
852 	 cv-qualified version of the RECORD_TYPE.  If we do, we
853 	 haven't changed the field that contains the actual pointer to
854 	 a method, and so TYPE_PTRMEMFUNC_FN_TYPE will be wrong.  */
855       tree t;
856 
857       t = TYPE_PTRMEMFUNC_FN_TYPE (type);
858       t = cp_build_qualified_type_real (t, type_quals, complain);
859       return build_ptrmemfunc_type (t);
860     }
861   else if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
862     {
863       tree t = PACK_EXPANSION_PATTERN (type);
864 
865       t = cp_build_qualified_type_real (t, type_quals, complain);
866       return make_pack_expansion (t);
867     }
868 
869   /* A reference or method type shall not be cv-qualified.
870      [dcl.ref], [dcl.fct]  */
871   if (type_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)
872       && (TREE_CODE (type) == REFERENCE_TYPE
873 	  || TREE_CODE (type) == METHOD_TYPE))
874     {
875       bad_quals |= type_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE);
876       type_quals &= ~(TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE);
877     }
878 
879   /* A restrict-qualified type must be a pointer (or reference)
880      to object or incomplete type. */
881   if ((type_quals & TYPE_QUAL_RESTRICT)
882       && TREE_CODE (type) != TEMPLATE_TYPE_PARM
883       && TREE_CODE (type) != TYPENAME_TYPE
884       && !POINTER_TYPE_P (type))
885     {
886       bad_quals |= TYPE_QUAL_RESTRICT;
887       type_quals &= ~TYPE_QUAL_RESTRICT;
888     }
889 
890   if (bad_quals == TYPE_UNQUALIFIED)
891     /*OK*/;
892   else if (!(complain & (tf_error | tf_ignore_bad_quals)))
893     return error_mark_node;
894   else
895     {
896       if (complain & tf_ignore_bad_quals)
897 	/* We're not going to warn about constifying things that can't
898 	   be constified.  */
899 	bad_quals &= ~TYPE_QUAL_CONST;
900       if (bad_quals)
901 	{
902 	  tree bad_type = build_qualified_type (ptr_type_node, bad_quals);
903 
904 	  if (!(complain & tf_ignore_bad_quals))
905 	    error ("%qV qualifiers cannot be applied to %qT",
906 		   bad_type, type);
907 	}
908     }
909 
910   /* Retrieve (or create) the appropriately qualified variant.  */
911   result = build_qualified_type (type, type_quals);
912 
913   /* If this was a pointer-to-method type, and we just made a copy,
914      then we need to unshare the record that holds the cached
915      pointer-to-member-function type, because these will be distinct
916      between the unqualified and qualified types.  */
917   if (result != type
918       && TREE_CODE (type) == POINTER_TYPE
919       && TREE_CODE (TREE_TYPE (type)) == METHOD_TYPE
920       && TYPE_LANG_SPECIFIC (result) == TYPE_LANG_SPECIFIC (type))
921     TYPE_LANG_SPECIFIC (result) = NULL;
922 
923   /* We may also have ended up building a new copy of the canonical
924      type of a pointer-to-method type, which could have the same
925      sharing problem described above.  */
926   if (TYPE_CANONICAL (result) != TYPE_CANONICAL (type)
927       && TREE_CODE (type) == POINTER_TYPE
928       && TREE_CODE (TREE_TYPE (type)) == METHOD_TYPE
929       && (TYPE_LANG_SPECIFIC (TYPE_CANONICAL (result))
930           == TYPE_LANG_SPECIFIC (TYPE_CANONICAL (type))))
931     TYPE_LANG_SPECIFIC (TYPE_CANONICAL (result)) = NULL;
932 
933   return result;
934 }
935 
936 /* Return TYPE with const and volatile removed.  */
937 
938 tree
939 cv_unqualified (tree type)
940 {
941   int quals = TYPE_QUALS (type);
942   quals &= ~(TYPE_QUAL_CONST|TYPE_QUAL_VOLATILE);
943   return cp_build_qualified_type (type, quals);
944 }
945 
946 /* Builds a qualified variant of T that is not a typedef variant.
947    E.g. consider the following declarations:
948      typedef const int ConstInt;
949      typedef ConstInt* PtrConstInt;
950    If T is PtrConstInt, this function returns a type representing
951      const int*.
952    In other words, if T is a typedef, the function returns the underlying type.
953    The cv-qualification and attributes of the type returned match the
954    input type.
955    They will always be compatible types.
956    The returned type is built so that all of its subtypes
957    recursively have their typedefs stripped as well.
958 
959    This is different from just returning TYPE_CANONICAL (T)
960    Because of several reasons:
961     * If T is a type that needs structural equality
962       its TYPE_CANONICAL (T) will be NULL.
963     * TYPE_CANONICAL (T) desn't carry type attributes
964       and looses template parameter names.   */
965 
966 tree
967 strip_typedefs (tree t)
968 {
969   tree result = NULL, type = NULL, t0 = NULL;
970 
971   if (!t || t == error_mark_node || t == TYPE_CANONICAL (t))
972     return t;
973 
974   gcc_assert (TYPE_P (t));
975 
976   switch (TREE_CODE (t))
977     {
978     case POINTER_TYPE:
979       type = strip_typedefs (TREE_TYPE (t));
980       result = build_pointer_type (type);
981       break;
982     case REFERENCE_TYPE:
983       type = strip_typedefs (TREE_TYPE (t));
984       result = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
985       break;
986     case OFFSET_TYPE:
987       t0 = strip_typedefs (TYPE_OFFSET_BASETYPE (t));
988       type = strip_typedefs (TREE_TYPE (t));
989       result = build_offset_type (t0, type);
990       break;
991     case RECORD_TYPE:
992       if (TYPE_PTRMEMFUNC_P (t))
993 	{
994 	  t0 = strip_typedefs (TYPE_PTRMEMFUNC_FN_TYPE (t));
995 	  result = build_ptrmemfunc_type (t0);
996 	}
997       break;
998     case ARRAY_TYPE:
999       type = strip_typedefs (TREE_TYPE (t));
1000       t0  = strip_typedefs (TYPE_DOMAIN (t));;
1001       result = build_cplus_array_type (type, t0);
1002       break;
1003     case FUNCTION_TYPE:
1004     case METHOD_TYPE:
1005       {
1006 	tree arg_types = NULL, arg_node, arg_type;
1007 	for (arg_node = TYPE_ARG_TYPES (t);
1008 	     arg_node;
1009 	     arg_node = TREE_CHAIN (arg_node))
1010 	  {
1011 	    if (arg_node == void_list_node)
1012 	      break;
1013 	    arg_type = strip_typedefs (TREE_VALUE (arg_node));
1014 	    gcc_assert (arg_type);
1015 
1016 	    arg_types =
1017 	      tree_cons (TREE_PURPOSE (arg_node), arg_type, arg_types);
1018 	  }
1019 
1020 	if (arg_types)
1021 	  arg_types = nreverse (arg_types);
1022 
1023 	/* A list of parameters not ending with an ellipsis
1024 	   must end with void_list_node.  */
1025 	if (arg_node)
1026 	  arg_types = chainon (arg_types, void_list_node);
1027 
1028 	type = strip_typedefs (TREE_TYPE (t));
1029 	if (TREE_CODE (t) == METHOD_TYPE)
1030 	  {
1031 	    tree class_type = TREE_TYPE (TREE_VALUE (arg_types));
1032 	    gcc_assert (class_type);
1033 	    result =
1034 	      build_method_type_directly (class_type, type,
1035 					  TREE_CHAIN (arg_types));
1036 	  }
1037 	else
1038 	    result = build_function_type (type,
1039 					  arg_types);
1040 
1041 	if (TYPE_RAISES_EXCEPTIONS (t))
1042 	  result = build_exception_variant (result,
1043 					    TYPE_RAISES_EXCEPTIONS (t));
1044       }
1045       break;
1046     case TYPENAME_TYPE:
1047       result = make_typename_type (strip_typedefs (TYPE_CONTEXT (t)),
1048 				   TYPENAME_TYPE_FULLNAME (t),
1049 				   typename_type, tf_none);
1050       break;
1051     default:
1052       break;
1053     }
1054 
1055   if (!result)
1056       result = TYPE_MAIN_VARIANT (t);
1057   if (TYPE_ATTRIBUTES (t))
1058     result = cp_build_type_attribute_variant (result, TYPE_ATTRIBUTES (t));
1059   return cp_build_qualified_type (result, cp_type_quals (t));
1060 }
1061 
1062 /* Returns true iff TYPE is a type variant created for a typedef. */
1063 
1064 bool
1065 typedef_variant_p (tree type)
1066 {
1067   return is_typedef_decl (TYPE_NAME (type));
1068 }
1069 
1070 /* Setup a TYPE_DECL node as a typedef representation.
1071    See comments of set_underlying_type in c-common.c.  */
1072 
1073 void
1074 cp_set_underlying_type (tree t)
1075 {
1076   set_underlying_type (t);
1077   /* If T is a template type parm, make it require structural equality.
1078      This is useful when comparing two template type parms,
1079      because it forces the comparison of the template parameters of their
1080      decls.  */
1081   if (TREE_CODE (TREE_TYPE (t)) == TEMPLATE_TYPE_PARM)
1082     SET_TYPE_STRUCTURAL_EQUALITY (TREE_TYPE (t));
1083 }
1084 
1085 
1086 /* Makes a copy of BINFO and TYPE, which is to be inherited into a
1087    graph dominated by T.  If BINFO is NULL, TYPE is a dependent base,
1088    and we do a shallow copy.  If BINFO is non-NULL, we do a deep copy.
1089    VIRT indicates whether TYPE is inherited virtually or not.
1090    IGO_PREV points at the previous binfo of the inheritance graph
1091    order chain.  The newly copied binfo's TREE_CHAIN forms this
1092    ordering.
1093 
1094    The CLASSTYPE_VBASECLASSES vector of T is constructed in the
1095    correct order. That is in the order the bases themselves should be
1096    constructed in.
1097 
1098    The BINFO_INHERITANCE of a virtual base class points to the binfo
1099    of the most derived type. ??? We could probably change this so that
1100    BINFO_INHERITANCE becomes synonymous with BINFO_PRIMARY, and hence
1101    remove a field.  They currently can only differ for primary virtual
1102    virtual bases.  */
1103 
1104 tree
1105 copy_binfo (tree binfo, tree type, tree t, tree *igo_prev, int virt)
1106 {
1107   tree new_binfo;
1108 
1109   if (virt)
1110     {
1111       /* See if we've already made this virtual base.  */
1112       new_binfo = binfo_for_vbase (type, t);
1113       if (new_binfo)
1114 	return new_binfo;
1115     }
1116 
1117   new_binfo = make_tree_binfo (binfo ? BINFO_N_BASE_BINFOS (binfo) : 0);
1118   BINFO_TYPE (new_binfo) = type;
1119 
1120   /* Chain it into the inheritance graph.  */
1121   TREE_CHAIN (*igo_prev) = new_binfo;
1122   *igo_prev = new_binfo;
1123 
1124   if (binfo)
1125     {
1126       int ix;
1127       tree base_binfo;
1128 
1129       gcc_assert (!BINFO_DEPENDENT_BASE_P (binfo));
1130       gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), type));
1131 
1132       BINFO_OFFSET (new_binfo) = BINFO_OFFSET (binfo);
1133       BINFO_VIRTUALS (new_binfo) = BINFO_VIRTUALS (binfo);
1134 
1135       /* We do not need to copy the accesses, as they are read only.  */
1136       BINFO_BASE_ACCESSES (new_binfo) = BINFO_BASE_ACCESSES (binfo);
1137 
1138       /* Recursively copy base binfos of BINFO.  */
1139       for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
1140 	{
1141 	  tree new_base_binfo;
1142 
1143 	  gcc_assert (!BINFO_DEPENDENT_BASE_P (base_binfo));
1144 	  new_base_binfo = copy_binfo (base_binfo, BINFO_TYPE (base_binfo),
1145 				       t, igo_prev,
1146 				       BINFO_VIRTUAL_P (base_binfo));
1147 
1148 	  if (!BINFO_INHERITANCE_CHAIN (new_base_binfo))
1149 	    BINFO_INHERITANCE_CHAIN (new_base_binfo) = new_binfo;
1150 	  BINFO_BASE_APPEND (new_binfo, new_base_binfo);
1151 	}
1152     }
1153   else
1154     BINFO_DEPENDENT_BASE_P (new_binfo) = 1;
1155 
1156   if (virt)
1157     {
1158       /* Push it onto the list after any virtual bases it contains
1159 	 will have been pushed.  */
1160       VEC_quick_push (tree, CLASSTYPE_VBASECLASSES (t), new_binfo);
1161       BINFO_VIRTUAL_P (new_binfo) = 1;
1162       BINFO_INHERITANCE_CHAIN (new_binfo) = TYPE_BINFO (t);
1163     }
1164 
1165   return new_binfo;
1166 }
1167 
1168 /* Hashing of lists so that we don't make duplicates.
1169    The entry point is `list_hash_canon'.  */
1170 
1171 /* Now here is the hash table.  When recording a list, it is added
1172    to the slot whose index is the hash code mod the table size.
1173    Note that the hash table is used for several kinds of lists.
1174    While all these live in the same table, they are completely independent,
1175    and the hash code is computed differently for each of these.  */
1176 
1177 static GTY ((param_is (union tree_node))) htab_t list_hash_table;
1178 
1179 struct list_proxy
1180 {
1181   tree purpose;
1182   tree value;
1183   tree chain;
1184 };
1185 
1186 /* Compare ENTRY (an entry in the hash table) with DATA (a list_proxy
1187    for a node we are thinking about adding).  */
1188 
1189 static int
1190 list_hash_eq (const void* entry, const void* data)
1191 {
1192   const_tree const t = (const_tree) entry;
1193   const struct list_proxy *const proxy = (const struct list_proxy *) data;
1194 
1195   return (TREE_VALUE (t) == proxy->value
1196 	  && TREE_PURPOSE (t) == proxy->purpose
1197 	  && TREE_CHAIN (t) == proxy->chain);
1198 }
1199 
1200 /* Compute a hash code for a list (chain of TREE_LIST nodes
1201    with goodies in the TREE_PURPOSE, TREE_VALUE, and bits of the
1202    TREE_COMMON slots), by adding the hash codes of the individual entries.  */
1203 
1204 static hashval_t
1205 list_hash_pieces (tree purpose, tree value, tree chain)
1206 {
1207   hashval_t hashcode = 0;
1208 
1209   if (chain)
1210     hashcode += TREE_HASH (chain);
1211 
1212   if (value)
1213     hashcode += TREE_HASH (value);
1214   else
1215     hashcode += 1007;
1216   if (purpose)
1217     hashcode += TREE_HASH (purpose);
1218   else
1219     hashcode += 1009;
1220   return hashcode;
1221 }
1222 
1223 /* Hash an already existing TREE_LIST.  */
1224 
1225 static hashval_t
1226 list_hash (const void* p)
1227 {
1228   const_tree const t = (const_tree) p;
1229   return list_hash_pieces (TREE_PURPOSE (t),
1230 			   TREE_VALUE (t),
1231 			   TREE_CHAIN (t));
1232 }
1233 
1234 /* Given list components PURPOSE, VALUE, AND CHAIN, return the canonical
1235    object for an identical list if one already exists.  Otherwise, build a
1236    new one, and record it as the canonical object.  */
1237 
1238 tree
1239 hash_tree_cons (tree purpose, tree value, tree chain)
1240 {
1241   int hashcode = 0;
1242   void **slot;
1243   struct list_proxy proxy;
1244 
1245   /* Hash the list node.  */
1246   hashcode = list_hash_pieces (purpose, value, chain);
1247   /* Create a proxy for the TREE_LIST we would like to create.  We
1248      don't actually create it so as to avoid creating garbage.  */
1249   proxy.purpose = purpose;
1250   proxy.value = value;
1251   proxy.chain = chain;
1252   /* See if it is already in the table.  */
1253   slot = htab_find_slot_with_hash (list_hash_table, &proxy, hashcode,
1254 				   INSERT);
1255   /* If not, create a new node.  */
1256   if (!*slot)
1257     *slot = tree_cons (purpose, value, chain);
1258   return (tree) *slot;
1259 }
1260 
1261 /* Constructor for hashed lists.  */
1262 
1263 tree
1264 hash_tree_chain (tree value, tree chain)
1265 {
1266   return hash_tree_cons (NULL_TREE, value, chain);
1267 }
1268 
1269 void
1270 debug_binfo (tree elem)
1271 {
1272   HOST_WIDE_INT n;
1273   tree virtuals;
1274 
1275   fprintf (stderr, "type \"%s\", offset = " HOST_WIDE_INT_PRINT_DEC
1276 	   "\nvtable type:\n",
1277 	   TYPE_NAME_STRING (BINFO_TYPE (elem)),
1278 	   TREE_INT_CST_LOW (BINFO_OFFSET (elem)));
1279   debug_tree (BINFO_TYPE (elem));
1280   if (BINFO_VTABLE (elem))
1281     fprintf (stderr, "vtable decl \"%s\"\n",
1282 	     IDENTIFIER_POINTER (DECL_NAME (get_vtbl_decl_for_binfo (elem))));
1283   else
1284     fprintf (stderr, "no vtable decl yet\n");
1285   fprintf (stderr, "virtuals:\n");
1286   virtuals = BINFO_VIRTUALS (elem);
1287   n = 0;
1288 
1289   while (virtuals)
1290     {
1291       tree fndecl = TREE_VALUE (virtuals);
1292       fprintf (stderr, "%s [%ld =? %ld]\n",
1293 	       IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (fndecl)),
1294 	       (long) n, (long) TREE_INT_CST_LOW (DECL_VINDEX (fndecl)));
1295       ++n;
1296       virtuals = TREE_CHAIN (virtuals);
1297     }
1298 }
1299 
1300 /* Build a representation for the qualified name SCOPE::NAME.  TYPE is
1301    the type of the result expression, if known, or NULL_TREE if the
1302    resulting expression is type-dependent.  If TEMPLATE_P is true,
1303    NAME is known to be a template because the user explicitly used the
1304    "template" keyword after the "::".
1305 
1306    All SCOPE_REFs should be built by use of this function.  */
1307 
1308 tree
1309 build_qualified_name (tree type, tree scope, tree name, bool template_p)
1310 {
1311   tree t;
1312   if (type == error_mark_node
1313       || scope == error_mark_node
1314       || name == error_mark_node)
1315     return error_mark_node;
1316   t = build2 (SCOPE_REF, type, scope, name);
1317   QUALIFIED_NAME_IS_TEMPLATE (t) = template_p;
1318   if (type)
1319     t = convert_from_reference (t);
1320   return t;
1321 }
1322 
1323 /* Returns nonzero if X is an expression for a (possibly overloaded)
1324    function.  If "f" is a function or function template, "f", "c->f",
1325    "c.f", "C::f", and "f<int>" will all be considered possibly
1326    overloaded functions.  Returns 2 if the function is actually
1327    overloaded, i.e., if it is impossible to know the type of the
1328    function without performing overload resolution.  */
1329 
1330 int
1331 is_overloaded_fn (tree x)
1332 {
1333   /* A baselink is also considered an overloaded function.  */
1334   if (TREE_CODE (x) == OFFSET_REF
1335       || TREE_CODE (x) == COMPONENT_REF)
1336     x = TREE_OPERAND (x, 1);
1337   if (BASELINK_P (x))
1338     x = BASELINK_FUNCTIONS (x);
1339   if (TREE_CODE (x) == TEMPLATE_ID_EXPR)
1340     x = TREE_OPERAND (x, 0);
1341   if (DECL_FUNCTION_TEMPLATE_P (OVL_CURRENT (x))
1342       || (TREE_CODE (x) == OVERLOAD && OVL_CHAIN (x)))
1343     return 2;
1344   return  (TREE_CODE (x) == FUNCTION_DECL
1345 	   || TREE_CODE (x) == OVERLOAD);
1346 }
1347 
1348 /* Returns true iff X is an expression for an overloaded function
1349    whose type cannot be known without performing overload
1350    resolution.  */
1351 
1352 bool
1353 really_overloaded_fn (tree x)
1354 {
1355   return is_overloaded_fn (x) == 2;
1356 }
1357 
1358 tree
1359 get_first_fn (tree from)
1360 {
1361   gcc_assert (is_overloaded_fn (from));
1362   /* A baselink is also considered an overloaded function.  */
1363   if (TREE_CODE (from) == OFFSET_REF
1364       || TREE_CODE (from) == COMPONENT_REF)
1365     from = TREE_OPERAND (from, 1);
1366   if (BASELINK_P (from))
1367     from = BASELINK_FUNCTIONS (from);
1368   if (TREE_CODE (from) == TEMPLATE_ID_EXPR)
1369     from = TREE_OPERAND (from, 0);
1370   return OVL_CURRENT (from);
1371 }
1372 
1373 /* Return a new OVL node, concatenating it with the old one.  */
1374 
1375 tree
1376 ovl_cons (tree decl, tree chain)
1377 {
1378   tree result = make_node (OVERLOAD);
1379   TREE_TYPE (result) = unknown_type_node;
1380   OVL_FUNCTION (result) = decl;
1381   TREE_CHAIN (result) = chain;
1382 
1383   return result;
1384 }
1385 
1386 /* Build a new overloaded function. If this is the first one,
1387    just return it; otherwise, ovl_cons the _DECLs */
1388 
1389 tree
1390 build_overload (tree decl, tree chain)
1391 {
1392   if (! chain && TREE_CODE (decl) != TEMPLATE_DECL)
1393     return decl;
1394   if (chain && TREE_CODE (chain) != OVERLOAD)
1395     chain = ovl_cons (chain, NULL_TREE);
1396   return ovl_cons (decl, chain);
1397 }
1398 
1399 
1400 #define PRINT_RING_SIZE 4
1401 
1402 static const char *
1403 cxx_printable_name_internal (tree decl, int v, bool translate)
1404 {
1405   static unsigned int uid_ring[PRINT_RING_SIZE];
1406   static char *print_ring[PRINT_RING_SIZE];
1407   static bool trans_ring[PRINT_RING_SIZE];
1408   static int ring_counter;
1409   int i;
1410 
1411   /* Only cache functions.  */
1412   if (v < 2
1413       || TREE_CODE (decl) != FUNCTION_DECL
1414       || DECL_LANG_SPECIFIC (decl) == 0)
1415     return lang_decl_name (decl, v, translate);
1416 
1417   /* See if this print name is lying around.  */
1418   for (i = 0; i < PRINT_RING_SIZE; i++)
1419     if (uid_ring[i] == DECL_UID (decl) && translate == trans_ring[i])
1420       /* yes, so return it.  */
1421       return print_ring[i];
1422 
1423   if (++ring_counter == PRINT_RING_SIZE)
1424     ring_counter = 0;
1425 
1426   if (current_function_decl != NULL_TREE)
1427     {
1428       /* There may be both translated and untranslated versions of the
1429 	 name cached.  */
1430       for (i = 0; i < 2; i++)
1431 	{
1432 	  if (uid_ring[ring_counter] == DECL_UID (current_function_decl))
1433 	    ring_counter += 1;
1434 	  if (ring_counter == PRINT_RING_SIZE)
1435 	    ring_counter = 0;
1436 	}
1437       gcc_assert (uid_ring[ring_counter] != DECL_UID (current_function_decl));
1438     }
1439 
1440   if (print_ring[ring_counter])
1441     free (print_ring[ring_counter]);
1442 
1443   print_ring[ring_counter] = xstrdup (lang_decl_name (decl, v, translate));
1444   uid_ring[ring_counter] = DECL_UID (decl);
1445   trans_ring[ring_counter] = translate;
1446   return print_ring[ring_counter];
1447 }
1448 
1449 const char *
1450 cxx_printable_name (tree decl, int v)
1451 {
1452   return cxx_printable_name_internal (decl, v, false);
1453 }
1454 
1455 const char *
1456 cxx_printable_name_translate (tree decl, int v)
1457 {
1458   return cxx_printable_name_internal (decl, v, true);
1459 }
1460 
1461 /* Build the FUNCTION_TYPE or METHOD_TYPE which may throw exceptions
1462    listed in RAISES.  */
1463 
1464 tree
1465 build_exception_variant (tree type, tree raises)
1466 {
1467   tree v = TYPE_MAIN_VARIANT (type);
1468   int type_quals = TYPE_QUALS (type);
1469 
1470   for (; v; v = TYPE_NEXT_VARIANT (v))
1471     if (check_qualified_type (v, type, type_quals)
1472 	&& comp_except_specs (raises, TYPE_RAISES_EXCEPTIONS (v), 1))
1473       return v;
1474 
1475   /* Need to build a new variant.  */
1476   v = build_variant_type_copy (type);
1477   TYPE_RAISES_EXCEPTIONS (v) = raises;
1478   return v;
1479 }
1480 
1481 /* Given a TEMPLATE_TEMPLATE_PARM node T, create a new
1482    BOUND_TEMPLATE_TEMPLATE_PARM bound with NEWARGS as its template
1483    arguments.  */
1484 
1485 tree
1486 bind_template_template_parm (tree t, tree newargs)
1487 {
1488   tree decl = TYPE_NAME (t);
1489   tree t2;
1490 
1491   t2 = cxx_make_type (BOUND_TEMPLATE_TEMPLATE_PARM);
1492   decl = build_decl (input_location,
1493 		     TYPE_DECL, DECL_NAME (decl), NULL_TREE);
1494 
1495   /* These nodes have to be created to reflect new TYPE_DECL and template
1496      arguments.  */
1497   TEMPLATE_TYPE_PARM_INDEX (t2) = copy_node (TEMPLATE_TYPE_PARM_INDEX (t));
1498   TEMPLATE_PARM_DECL (TEMPLATE_TYPE_PARM_INDEX (t2)) = decl;
1499   TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t2)
1500     = build_template_info (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t), newargs);
1501 
1502   TREE_TYPE (decl) = t2;
1503   TYPE_NAME (t2) = decl;
1504   TYPE_STUB_DECL (t2) = decl;
1505   TYPE_SIZE (t2) = 0;
1506   SET_TYPE_STRUCTURAL_EQUALITY (t2);
1507 
1508   return t2;
1509 }
1510 
1511 /* Called from count_trees via walk_tree.  */
1512 
1513 static tree
1514 count_trees_r (tree *tp, int *walk_subtrees, void *data)
1515 {
1516   ++*((int *) data);
1517 
1518   if (TYPE_P (*tp))
1519     *walk_subtrees = 0;
1520 
1521   return NULL_TREE;
1522 }
1523 
1524 /* Debugging function for measuring the rough complexity of a tree
1525    representation.  */
1526 
1527 int
1528 count_trees (tree t)
1529 {
1530   int n_trees = 0;
1531   cp_walk_tree_without_duplicates (&t, count_trees_r, &n_trees);
1532   return n_trees;
1533 }
1534 
1535 /* Called from verify_stmt_tree via walk_tree.  */
1536 
1537 static tree
1538 verify_stmt_tree_r (tree* tp,
1539 		    int* walk_subtrees ATTRIBUTE_UNUSED ,
1540 		    void* data)
1541 {
1542   tree t = *tp;
1543   htab_t *statements = (htab_t *) data;
1544   void **slot;
1545 
1546   if (!STATEMENT_CODE_P (TREE_CODE (t)))
1547     return NULL_TREE;
1548 
1549   /* If this statement is already present in the hash table, then
1550      there is a circularity in the statement tree.  */
1551   gcc_assert (!htab_find (*statements, t));
1552 
1553   slot = htab_find_slot (*statements, t, INSERT);
1554   *slot = t;
1555 
1556   return NULL_TREE;
1557 }
1558 
1559 /* Debugging function to check that the statement T has not been
1560    corrupted.  For now, this function simply checks that T contains no
1561    circularities.  */
1562 
1563 void
1564 verify_stmt_tree (tree t)
1565 {
1566   htab_t statements;
1567   statements = htab_create (37, htab_hash_pointer, htab_eq_pointer, NULL);
1568   cp_walk_tree (&t, verify_stmt_tree_r, &statements, NULL);
1569   htab_delete (statements);
1570 }
1571 
1572 /* Check if the type T depends on a type with no linkage and if so, return
1573    it.  If RELAXED_P then do not consider a class type declared within
1574    a vague-linkage function to have no linkage.  */
1575 
1576 tree
1577 no_linkage_check (tree t, bool relaxed_p)
1578 {
1579   tree r;
1580 
1581   /* There's no point in checking linkage on template functions; we
1582      can't know their complete types.  */
1583   if (processing_template_decl)
1584     return NULL_TREE;
1585 
1586   switch (TREE_CODE (t))
1587     {
1588     case RECORD_TYPE:
1589       if (TYPE_PTRMEMFUNC_P (t))
1590 	goto ptrmem;
1591       /* Lambda types that don't have mangling scope have no linkage.  We
1592 	 check CLASSTYPE_LAMBDA_EXPR here rather than LAMBDA_TYPE_P because
1593 	 when we get here from pushtag none of the lambda information is
1594 	 set up yet, so we want to assume that the lambda has linkage and
1595 	 fix it up later if not.  */
1596       if (CLASSTYPE_LAMBDA_EXPR (t)
1597 	  && LAMBDA_TYPE_EXTRA_SCOPE (t) == NULL_TREE)
1598 	return t;
1599       /* Fall through.  */
1600     case UNION_TYPE:
1601       if (!CLASS_TYPE_P (t))
1602 	return NULL_TREE;
1603       /* Fall through.  */
1604     case ENUMERAL_TYPE:
1605       /* Only treat anonymous types as having no linkage if they're at
1606 	 namespace scope.  This is core issue 966.  */
1607       if (TYPE_ANONYMOUS_P (t) && TYPE_NAMESPACE_SCOPE_P (t))
1608 	return t;
1609 
1610       for (r = CP_TYPE_CONTEXT (t); ; )
1611 	{
1612 	  /* If we're a nested type of a !TREE_PUBLIC class, we might not
1613 	     have linkage, or we might just be in an anonymous namespace.
1614 	     If we're in a TREE_PUBLIC class, we have linkage.  */
1615 	  if (TYPE_P (r) && !TREE_PUBLIC (TYPE_NAME (r)))
1616 	    return no_linkage_check (TYPE_CONTEXT (t), relaxed_p);
1617 	  else if (TREE_CODE (r) == FUNCTION_DECL)
1618 	    {
1619 	      if (!relaxed_p || !vague_linkage_p (r))
1620 		return t;
1621 	      else
1622 		r = CP_DECL_CONTEXT (r);
1623 	    }
1624 	  else
1625 	    break;
1626 	}
1627 
1628       return NULL_TREE;
1629 
1630     case ARRAY_TYPE:
1631     case POINTER_TYPE:
1632     case REFERENCE_TYPE:
1633       return no_linkage_check (TREE_TYPE (t), relaxed_p);
1634 
1635     case OFFSET_TYPE:
1636     ptrmem:
1637       r = no_linkage_check (TYPE_PTRMEM_POINTED_TO_TYPE (t),
1638 			    relaxed_p);
1639       if (r)
1640 	return r;
1641       return no_linkage_check (TYPE_PTRMEM_CLASS_TYPE (t), relaxed_p);
1642 
1643     case METHOD_TYPE:
1644       r = no_linkage_check (TYPE_METHOD_BASETYPE (t), relaxed_p);
1645       if (r)
1646 	return r;
1647       /* Fall through.  */
1648     case FUNCTION_TYPE:
1649       {
1650 	tree parm;
1651 	for (parm = TYPE_ARG_TYPES (t);
1652 	     parm && parm != void_list_node;
1653 	     parm = TREE_CHAIN (parm))
1654 	  {
1655 	    r = no_linkage_check (TREE_VALUE (parm), relaxed_p);
1656 	    if (r)
1657 	      return r;
1658 	  }
1659 	return no_linkage_check (TREE_TYPE (t), relaxed_p);
1660       }
1661 
1662     default:
1663       return NULL_TREE;
1664     }
1665 }
1666 
1667 #ifdef GATHER_STATISTICS
1668 extern int depth_reached;
1669 #endif
1670 
1671 void
1672 cxx_print_statistics (void)
1673 {
1674   print_search_statistics ();
1675   print_class_statistics ();
1676 #ifdef GATHER_STATISTICS
1677   fprintf (stderr, "maximum template instantiation depth reached: %d\n",
1678 	   depth_reached);
1679 #endif
1680 }
1681 
1682 /* Return, as an INTEGER_CST node, the number of elements for TYPE
1683    (which is an ARRAY_TYPE).  This counts only elements of the top
1684    array.  */
1685 
1686 tree
1687 array_type_nelts_top (tree type)
1688 {
1689   return fold_build2_loc (input_location,
1690 		      PLUS_EXPR, sizetype,
1691 		      array_type_nelts (type),
1692 		      size_one_node);
1693 }
1694 
1695 /* Return, as an INTEGER_CST node, the number of elements for TYPE
1696    (which is an ARRAY_TYPE).  This one is a recursive count of all
1697    ARRAY_TYPEs that are clumped together.  */
1698 
1699 tree
1700 array_type_nelts_total (tree type)
1701 {
1702   tree sz = array_type_nelts_top (type);
1703   type = TREE_TYPE (type);
1704   while (TREE_CODE (type) == ARRAY_TYPE)
1705     {
1706       tree n = array_type_nelts_top (type);
1707       sz = fold_build2_loc (input_location,
1708 			MULT_EXPR, sizetype, sz, n);
1709       type = TREE_TYPE (type);
1710     }
1711   return sz;
1712 }
1713 
1714 /* Called from break_out_target_exprs via mapcar.  */
1715 
1716 static tree
1717 bot_manip (tree* tp, int* walk_subtrees, void* data)
1718 {
1719   splay_tree target_remap = ((splay_tree) data);
1720   tree t = *tp;
1721 
1722   if (!TYPE_P (t) && TREE_CONSTANT (t))
1723     {
1724       /* There can't be any TARGET_EXPRs or their slot variables below
1725 	 this point.  We used to check !TREE_SIDE_EFFECTS, but then we
1726 	 failed to copy an ADDR_EXPR of the slot VAR_DECL.  */
1727       *walk_subtrees = 0;
1728       return NULL_TREE;
1729     }
1730   if (TREE_CODE (t) == TARGET_EXPR)
1731     {
1732       tree u;
1733 
1734       if (TREE_CODE (TREE_OPERAND (t, 1)) == AGGR_INIT_EXPR)
1735 	{
1736 	  u = build_cplus_new (TREE_TYPE (t), TREE_OPERAND (t, 1));
1737 	  if (AGGR_INIT_ZERO_FIRST (TREE_OPERAND (t, 1)))
1738 	    AGGR_INIT_ZERO_FIRST (TREE_OPERAND (u, 1)) = true;
1739 	}
1740       else
1741 	u = build_target_expr_with_type (TREE_OPERAND (t, 1), TREE_TYPE (t));
1742 
1743       /* Map the old variable to the new one.  */
1744       splay_tree_insert (target_remap,
1745 			 (splay_tree_key) TREE_OPERAND (t, 0),
1746 			 (splay_tree_value) TREE_OPERAND (u, 0));
1747 
1748       TREE_OPERAND (u, 1) = break_out_target_exprs (TREE_OPERAND (u, 1));
1749 
1750       /* Replace the old expression with the new version.  */
1751       *tp = u;
1752       /* We don't have to go below this point; the recursive call to
1753 	 break_out_target_exprs will have handled anything below this
1754 	 point.  */
1755       *walk_subtrees = 0;
1756       return NULL_TREE;
1757     }
1758 
1759   /* Make a copy of this node.  */
1760   return copy_tree_r (tp, walk_subtrees, NULL);
1761 }
1762 
1763 /* Replace all remapped VAR_DECLs in T with their new equivalents.
1764    DATA is really a splay-tree mapping old variables to new
1765    variables.  */
1766 
1767 static tree
1768 bot_replace (tree* t,
1769 	     int* walk_subtrees ATTRIBUTE_UNUSED ,
1770 	     void* data)
1771 {
1772   splay_tree target_remap = ((splay_tree) data);
1773 
1774   if (TREE_CODE (*t) == VAR_DECL)
1775     {
1776       splay_tree_node n = splay_tree_lookup (target_remap,
1777 					     (splay_tree_key) *t);
1778       if (n)
1779 	*t = (tree) n->value;
1780     }
1781 
1782   return NULL_TREE;
1783 }
1784 
1785 /* When we parse a default argument expression, we may create
1786    temporary variables via TARGET_EXPRs.  When we actually use the
1787    default-argument expression, we make a copy of the expression, but
1788    we must replace the temporaries with appropriate local versions.  */
1789 
1790 tree
1791 break_out_target_exprs (tree t)
1792 {
1793   static int target_remap_count;
1794   static splay_tree target_remap;
1795 
1796   if (!target_remap_count++)
1797     target_remap = splay_tree_new (splay_tree_compare_pointers,
1798 				   /*splay_tree_delete_key_fn=*/NULL,
1799 				   /*splay_tree_delete_value_fn=*/NULL);
1800   cp_walk_tree (&t, bot_manip, target_remap, NULL);
1801   cp_walk_tree (&t, bot_replace, target_remap, NULL);
1802 
1803   if (!--target_remap_count)
1804     {
1805       splay_tree_delete (target_remap);
1806       target_remap = NULL;
1807     }
1808 
1809   return t;
1810 }
1811 
1812 /* Similar to `build_nt', but for template definitions of dependent
1813    expressions  */
1814 
1815 tree
1816 build_min_nt (enum tree_code code, ...)
1817 {
1818   tree t;
1819   int length;
1820   int i;
1821   va_list p;
1822 
1823   gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
1824 
1825   va_start (p, code);
1826 
1827   t = make_node (code);
1828   length = TREE_CODE_LENGTH (code);
1829 
1830   for (i = 0; i < length; i++)
1831     {
1832       tree x = va_arg (p, tree);
1833       TREE_OPERAND (t, i) = x;
1834     }
1835 
1836   va_end (p);
1837   return t;
1838 }
1839 
1840 
1841 /* Similar to `build', but for template definitions.  */
1842 
1843 tree
1844 build_min (enum tree_code code, tree tt, ...)
1845 {
1846   tree t;
1847   int length;
1848   int i;
1849   va_list p;
1850 
1851   gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
1852 
1853   va_start (p, tt);
1854 
1855   t = make_node (code);
1856   length = TREE_CODE_LENGTH (code);
1857   TREE_TYPE (t) = tt;
1858 
1859   for (i = 0; i < length; i++)
1860     {
1861       tree x = va_arg (p, tree);
1862       TREE_OPERAND (t, i) = x;
1863       if (x && !TYPE_P (x) && TREE_SIDE_EFFECTS (x))
1864 	TREE_SIDE_EFFECTS (t) = 1;
1865     }
1866 
1867   va_end (p);
1868   return t;
1869 }
1870 
1871 /* Similar to `build', but for template definitions of non-dependent
1872    expressions. NON_DEP is the non-dependent expression that has been
1873    built.  */
1874 
1875 tree
1876 build_min_non_dep (enum tree_code code, tree non_dep, ...)
1877 {
1878   tree t;
1879   int length;
1880   int i;
1881   va_list p;
1882 
1883   gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
1884 
1885   va_start (p, non_dep);
1886 
1887   t = make_node (code);
1888   length = TREE_CODE_LENGTH (code);
1889   TREE_TYPE (t) = TREE_TYPE (non_dep);
1890   TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (non_dep);
1891 
1892   for (i = 0; i < length; i++)
1893     {
1894       tree x = va_arg (p, tree);
1895       TREE_OPERAND (t, i) = x;
1896     }
1897 
1898   if (code == COMPOUND_EXPR && TREE_CODE (non_dep) != COMPOUND_EXPR)
1899     /* This should not be considered a COMPOUND_EXPR, because it
1900        resolves to an overload.  */
1901     COMPOUND_EXPR_OVERLOADED (t) = 1;
1902 
1903   va_end (p);
1904   return t;
1905 }
1906 
1907 /* Similar to `build_call_list', but for template definitions of non-dependent
1908    expressions. NON_DEP is the non-dependent expression that has been
1909    built.  */
1910 
1911 tree
1912 build_min_non_dep_call_vec (tree non_dep, tree fn, VEC(tree,gc) *argvec)
1913 {
1914   tree t = build_nt_call_vec (fn, argvec);
1915   TREE_TYPE (t) = TREE_TYPE (non_dep);
1916   TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (non_dep);
1917   return t;
1918 }
1919 
1920 tree
1921 get_type_decl (tree t)
1922 {
1923   if (TREE_CODE (t) == TYPE_DECL)
1924     return t;
1925   if (TYPE_P (t))
1926     return TYPE_STUB_DECL (t);
1927   gcc_assert (t == error_mark_node);
1928   return t;
1929 }
1930 
1931 /* Returns the namespace that contains DECL, whether directly or
1932    indirectly.  */
1933 
1934 tree
1935 decl_namespace_context (tree decl)
1936 {
1937   while (1)
1938     {
1939       if (TREE_CODE (decl) == NAMESPACE_DECL)
1940 	return decl;
1941       else if (TYPE_P (decl))
1942 	decl = CP_DECL_CONTEXT (TYPE_MAIN_DECL (decl));
1943       else
1944 	decl = CP_DECL_CONTEXT (decl);
1945     }
1946 }
1947 
1948 /* Returns true if decl is within an anonymous namespace, however deeply
1949    nested, or false otherwise.  */
1950 
1951 bool
1952 decl_anon_ns_mem_p (const_tree decl)
1953 {
1954   while (1)
1955     {
1956       if (decl == NULL_TREE || decl == error_mark_node)
1957 	return false;
1958       if (TREE_CODE (decl) == NAMESPACE_DECL
1959 	  && DECL_NAME (decl) == NULL_TREE)
1960 	return true;
1961       /* Classes and namespaces inside anonymous namespaces have
1962          TREE_PUBLIC == 0, so we can shortcut the search.  */
1963       else if (TYPE_P (decl))
1964 	return (TREE_PUBLIC (TYPE_NAME (decl)) == 0);
1965       else if (TREE_CODE (decl) == NAMESPACE_DECL)
1966 	return (TREE_PUBLIC (decl) == 0);
1967       else
1968 	decl = DECL_CONTEXT (decl);
1969     }
1970 }
1971 
1972 /* Return truthvalue of whether T1 is the same tree structure as T2.
1973    Return 1 if they are the same. Return 0 if they are different.  */
1974 
1975 bool
1976 cp_tree_equal (tree t1, tree t2)
1977 {
1978   enum tree_code code1, code2;
1979 
1980   if (t1 == t2)
1981     return true;
1982   if (!t1 || !t2)
1983     return false;
1984 
1985   for (code1 = TREE_CODE (t1);
1986        CONVERT_EXPR_CODE_P (code1)
1987 	 || code1 == NON_LVALUE_EXPR;
1988        code1 = TREE_CODE (t1))
1989     t1 = TREE_OPERAND (t1, 0);
1990   for (code2 = TREE_CODE (t2);
1991        CONVERT_EXPR_CODE_P (code2)
1992 	 || code1 == NON_LVALUE_EXPR;
1993        code2 = TREE_CODE (t2))
1994     t2 = TREE_OPERAND (t2, 0);
1995 
1996   /* They might have become equal now.  */
1997   if (t1 == t2)
1998     return true;
1999 
2000   if (code1 != code2)
2001     return false;
2002 
2003   switch (code1)
2004     {
2005     case INTEGER_CST:
2006       return TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
2007 	&& TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2);
2008 
2009     case REAL_CST:
2010       return REAL_VALUES_EQUAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2011 
2012     case STRING_CST:
2013       return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2014 	&& !memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2015 		    TREE_STRING_LENGTH (t1));
2016 
2017     case FIXED_CST:
2018       return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (t1),
2019 				     TREE_FIXED_CST (t2));
2020 
2021     case COMPLEX_CST:
2022       return cp_tree_equal (TREE_REALPART (t1), TREE_REALPART (t2))
2023 	&& cp_tree_equal (TREE_IMAGPART (t1), TREE_IMAGPART (t2));
2024 
2025     case CONSTRUCTOR:
2026       /* We need to do this when determining whether or not two
2027 	 non-type pointer to member function template arguments
2028 	 are the same.  */
2029       if (!(same_type_p (TREE_TYPE (t1), TREE_TYPE (t2))
2030 	    /* The first operand is RTL.  */
2031 	    && TREE_OPERAND (t1, 0) == TREE_OPERAND (t2, 0)))
2032 	return false;
2033       return cp_tree_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
2034 
2035     case TREE_LIST:
2036       if (!cp_tree_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2)))
2037 	return false;
2038       if (!cp_tree_equal (TREE_VALUE (t1), TREE_VALUE (t2)))
2039 	return false;
2040       return cp_tree_equal (TREE_CHAIN (t1), TREE_CHAIN (t2));
2041 
2042     case SAVE_EXPR:
2043       return cp_tree_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2044 
2045     case CALL_EXPR:
2046       {
2047 	tree arg1, arg2;
2048 	call_expr_arg_iterator iter1, iter2;
2049 	if (!cp_tree_equal (CALL_EXPR_FN (t1), CALL_EXPR_FN (t2)))
2050 	  return false;
2051 	for (arg1 = first_call_expr_arg (t1, &iter1),
2052 	       arg2 = first_call_expr_arg (t2, &iter2);
2053 	     arg1 && arg2;
2054 	     arg1 = next_call_expr_arg (&iter1),
2055 	       arg2 = next_call_expr_arg (&iter2))
2056 	  if (!cp_tree_equal (arg1, arg2))
2057 	    return false;
2058 	if (arg1 || arg2)
2059 	  return false;
2060 	return true;
2061       }
2062 
2063     case TARGET_EXPR:
2064       {
2065 	tree o1 = TREE_OPERAND (t1, 0);
2066 	tree o2 = TREE_OPERAND (t2, 0);
2067 
2068 	/* Special case: if either target is an unallocated VAR_DECL,
2069 	   it means that it's going to be unified with whatever the
2070 	   TARGET_EXPR is really supposed to initialize, so treat it
2071 	   as being equivalent to anything.  */
2072 	if (TREE_CODE (o1) == VAR_DECL && DECL_NAME (o1) == NULL_TREE
2073 	    && !DECL_RTL_SET_P (o1))
2074 	  /*Nop*/;
2075 	else if (TREE_CODE (o2) == VAR_DECL && DECL_NAME (o2) == NULL_TREE
2076 		 && !DECL_RTL_SET_P (o2))
2077 	  /*Nop*/;
2078 	else if (!cp_tree_equal (o1, o2))
2079 	  return false;
2080 
2081 	return cp_tree_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
2082       }
2083 
2084     case WITH_CLEANUP_EXPR:
2085       if (!cp_tree_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)))
2086 	return false;
2087       return cp_tree_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t1, 1));
2088 
2089     case COMPONENT_REF:
2090       if (TREE_OPERAND (t1, 1) != TREE_OPERAND (t2, 1))
2091 	return false;
2092       return cp_tree_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2093 
2094     case PARM_DECL:
2095       /* For comparing uses of parameters in late-specified return types
2096 	 with an out-of-class definition of the function, but can also come
2097 	 up for expressions that involve 'this' in a member function
2098 	 template.  */
2099       if (same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
2100 	{
2101 	  if (DECL_ARTIFICIAL (t1) ^ DECL_ARTIFICIAL (t2))
2102 	    return false;
2103 	  if (DECL_ARTIFICIAL (t1)
2104 	      || DECL_PARM_INDEX (t1) == DECL_PARM_INDEX (t2))
2105 	    return true;
2106 	}
2107       return false;
2108 
2109     case VAR_DECL:
2110     case CONST_DECL:
2111     case FUNCTION_DECL:
2112     case TEMPLATE_DECL:
2113     case IDENTIFIER_NODE:
2114     case SSA_NAME:
2115       return false;
2116 
2117     case BASELINK:
2118       return (BASELINK_BINFO (t1) == BASELINK_BINFO (t2)
2119 	      && BASELINK_ACCESS_BINFO (t1) == BASELINK_ACCESS_BINFO (t2)
2120 	      && cp_tree_equal (BASELINK_FUNCTIONS (t1),
2121 				BASELINK_FUNCTIONS (t2)));
2122 
2123     case TEMPLATE_PARM_INDEX:
2124       return (TEMPLATE_PARM_IDX (t1) == TEMPLATE_PARM_IDX (t2)
2125 	      && TEMPLATE_PARM_LEVEL (t1) == TEMPLATE_PARM_LEVEL (t2)
2126 	      && (TEMPLATE_PARM_PARAMETER_PACK (t1)
2127 		  == TEMPLATE_PARM_PARAMETER_PACK (t2))
2128 	      && same_type_p (TREE_TYPE (TEMPLATE_PARM_DECL (t1)),
2129 			      TREE_TYPE (TEMPLATE_PARM_DECL (t2))));
2130 
2131     case TEMPLATE_ID_EXPR:
2132       {
2133 	unsigned ix;
2134 	tree vec1, vec2;
2135 
2136 	if (!cp_tree_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)))
2137 	  return false;
2138 	vec1 = TREE_OPERAND (t1, 1);
2139 	vec2 = TREE_OPERAND (t2, 1);
2140 
2141 	if (!vec1 || !vec2)
2142 	  return !vec1 && !vec2;
2143 
2144 	if (TREE_VEC_LENGTH (vec1) != TREE_VEC_LENGTH (vec2))
2145 	  return false;
2146 
2147 	for (ix = TREE_VEC_LENGTH (vec1); ix--;)
2148 	  if (!cp_tree_equal (TREE_VEC_ELT (vec1, ix),
2149 			      TREE_VEC_ELT (vec2, ix)))
2150 	    return false;
2151 
2152 	return true;
2153       }
2154 
2155     case SIZEOF_EXPR:
2156     case ALIGNOF_EXPR:
2157       {
2158 	tree o1 = TREE_OPERAND (t1, 0);
2159 	tree o2 = TREE_OPERAND (t2, 0);
2160 
2161 	if (TREE_CODE (o1) != TREE_CODE (o2))
2162 	  return false;
2163 	if (TYPE_P (o1))
2164 	  return same_type_p (o1, o2);
2165 	else
2166 	  return cp_tree_equal (o1, o2);
2167       }
2168 
2169     case MODOP_EXPR:
2170       {
2171 	tree t1_op1, t2_op1;
2172 
2173 	if (!cp_tree_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)))
2174 	  return false;
2175 
2176 	t1_op1 = TREE_OPERAND (t1, 1);
2177 	t2_op1 = TREE_OPERAND (t2, 1);
2178 	if (TREE_CODE (t1_op1) != TREE_CODE (t2_op1))
2179 	  return false;
2180 
2181 	return cp_tree_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t2, 2));
2182       }
2183 
2184     case PTRMEM_CST:
2185       /* Two pointer-to-members are the same if they point to the same
2186 	 field or function in the same class.  */
2187       if (PTRMEM_CST_MEMBER (t1) != PTRMEM_CST_MEMBER (t2))
2188 	return false;
2189 
2190       return same_type_p (PTRMEM_CST_CLASS (t1), PTRMEM_CST_CLASS (t2));
2191 
2192     case OVERLOAD:
2193       if (OVL_FUNCTION (t1) != OVL_FUNCTION (t2))
2194 	return false;
2195       return cp_tree_equal (OVL_CHAIN (t1), OVL_CHAIN (t2));
2196 
2197     case TRAIT_EXPR:
2198       if (TRAIT_EXPR_KIND (t1) != TRAIT_EXPR_KIND (t2))
2199 	return false;
2200       return same_type_p (TRAIT_EXPR_TYPE1 (t1), TRAIT_EXPR_TYPE1 (t2))
2201 	&& same_type_p (TRAIT_EXPR_TYPE2 (t1), TRAIT_EXPR_TYPE2 (t2));
2202 
2203     default:
2204       break;
2205     }
2206 
2207   switch (TREE_CODE_CLASS (code1))
2208     {
2209     case tcc_unary:
2210     case tcc_binary:
2211     case tcc_comparison:
2212     case tcc_expression:
2213     case tcc_vl_exp:
2214     case tcc_reference:
2215     case tcc_statement:
2216       {
2217 	int i, n;
2218 
2219 	n = TREE_OPERAND_LENGTH (t1);
2220 	if (TREE_CODE_CLASS (code1) == tcc_vl_exp
2221 	    && n != TREE_OPERAND_LENGTH (t2))
2222 	  return false;
2223 
2224 	for (i = 0; i < n; ++i)
2225 	  if (!cp_tree_equal (TREE_OPERAND (t1, i), TREE_OPERAND (t2, i)))
2226 	    return false;
2227 
2228 	return true;
2229       }
2230 
2231     case tcc_type:
2232       return same_type_p (t1, t2);
2233     default:
2234       gcc_unreachable ();
2235     }
2236   /* We can get here with --disable-checking.  */
2237   return false;
2238 }
2239 
2240 /* The type of ARG when used as an lvalue.  */
2241 
2242 tree
2243 lvalue_type (tree arg)
2244 {
2245   tree type = TREE_TYPE (arg);
2246   return type;
2247 }
2248 
2249 /* The type of ARG for printing error messages; denote lvalues with
2250    reference types.  */
2251 
2252 tree
2253 error_type (tree arg)
2254 {
2255   tree type = TREE_TYPE (arg);
2256 
2257   if (TREE_CODE (type) == ARRAY_TYPE)
2258     ;
2259   else if (TREE_CODE (type) == ERROR_MARK)
2260     ;
2261   else if (real_lvalue_p (arg))
2262     type = build_reference_type (lvalue_type (arg));
2263   else if (MAYBE_CLASS_TYPE_P (type))
2264     type = lvalue_type (arg);
2265 
2266   return type;
2267 }
2268 
2269 /* Does FUNCTION use a variable-length argument list?  */
2270 
2271 int
2272 varargs_function_p (const_tree function)
2273 {
2274   const_tree parm = TYPE_ARG_TYPES (TREE_TYPE (function));
2275   for (; parm; parm = TREE_CHAIN (parm))
2276     if (TREE_VALUE (parm) == void_type_node)
2277       return 0;
2278   return 1;
2279 }
2280 
2281 /* Returns 1 if decl is a member of a class.  */
2282 
2283 int
2284 member_p (const_tree decl)
2285 {
2286   const_tree const ctx = DECL_CONTEXT (decl);
2287   return (ctx && TYPE_P (ctx));
2288 }
2289 
2290 /* Create a placeholder for member access where we don't actually have an
2291    object that the access is against.  */
2292 
2293 tree
2294 build_dummy_object (tree type)
2295 {
2296   tree decl = build1 (NOP_EXPR, build_pointer_type (type), void_zero_node);
2297   return cp_build_indirect_ref (decl, RO_NULL, tf_warning_or_error);
2298 }
2299 
2300 /* We've gotten a reference to a member of TYPE.  Return *this if appropriate,
2301    or a dummy object otherwise.  If BINFOP is non-0, it is filled with the
2302    binfo path from current_class_type to TYPE, or 0.  */
2303 
2304 tree
2305 maybe_dummy_object (tree type, tree* binfop)
2306 {
2307   tree decl, context;
2308   tree binfo;
2309 
2310   if (current_class_type
2311       && (binfo = lookup_base (current_class_type, type,
2312 			       ba_unique | ba_quiet, NULL)))
2313     context = current_class_type;
2314   else
2315     {
2316       /* Reference from a nested class member function.  */
2317       context = type;
2318       binfo = TYPE_BINFO (type);
2319     }
2320 
2321   if (binfop)
2322     *binfop = binfo;
2323 
2324   if (current_class_ref && context == current_class_type
2325       /* Kludge: Make sure that current_class_type is actually
2326 	 correct.  It might not be if we're in the middle of
2327 	 tsubst_default_argument.  */
2328       && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (current_class_ref)),
2329 		      current_class_type))
2330     decl = current_class_ref;
2331   else if (current_class_ref && LAMBDA_TYPE_P (current_class_type)
2332 	   && context == nonlambda_method_basetype ())
2333     /* In a lambda, need to go through 'this' capture.  */
2334     decl = (cp_build_indirect_ref
2335 	    ((lambda_expr_this_capture
2336 	      (CLASSTYPE_LAMBDA_EXPR (current_class_type))),
2337 	     RO_NULL, tf_warning_or_error));
2338   else
2339     decl = build_dummy_object (context);
2340 
2341   return decl;
2342 }
2343 
2344 /* Returns 1 if OB is a placeholder object, or a pointer to one.  */
2345 
2346 int
2347 is_dummy_object (const_tree ob)
2348 {
2349   if (TREE_CODE (ob) == INDIRECT_REF)
2350     ob = TREE_OPERAND (ob, 0);
2351   return (TREE_CODE (ob) == NOP_EXPR
2352 	  && TREE_OPERAND (ob, 0) == void_zero_node);
2353 }
2354 
2355 /* Returns 1 iff type T is something we want to treat as a scalar type for
2356    the purpose of deciding whether it is trivial/POD/standard-layout.  */
2357 
2358 static bool
2359 scalarish_type_p (const_tree t)
2360 {
2361   if (t == error_mark_node)
2362     return 1;
2363 
2364   return (SCALAR_TYPE_P (t)
2365 	  || TREE_CODE (t) == VECTOR_TYPE);
2366 }
2367 
2368 /* Returns true iff T requires non-trivial default initialization.  */
2369 
2370 bool
2371 type_has_nontrivial_default_init (const_tree t)
2372 {
2373   t = strip_array_types (CONST_CAST_TREE (t));
2374 
2375   if (CLASS_TYPE_P (t))
2376     return TYPE_HAS_COMPLEX_DFLT (t);
2377   else
2378     return 0;
2379 }
2380 
2381 /* Returns true iff copying an object of type T is non-trivial.  */
2382 
2383 bool
2384 type_has_nontrivial_copy_init (const_tree t)
2385 {
2386   t = strip_array_types (CONST_CAST_TREE (t));
2387 
2388   if (CLASS_TYPE_P (t))
2389     return TYPE_HAS_COMPLEX_INIT_REF (t);
2390   else
2391     return 0;
2392 }
2393 
2394 /* Returns 1 iff type T is a trivial type, as defined in [basic.types].  */
2395 
2396 bool
2397 trivial_type_p (const_tree t)
2398 {
2399   t = strip_array_types (CONST_CAST_TREE (t));
2400 
2401   if (CLASS_TYPE_P (t))
2402     return (TYPE_HAS_TRIVIAL_DFLT (t)
2403 	    && TYPE_HAS_TRIVIAL_INIT_REF (t)
2404 	    && TYPE_HAS_TRIVIAL_ASSIGN_REF (t)
2405 	    && TYPE_HAS_TRIVIAL_DESTRUCTOR (t));
2406   else
2407     return scalarish_type_p (t);
2408 }
2409 
2410 /* Returns 1 iff type T is a POD type, as defined in [basic.types].  */
2411 
2412 bool
2413 pod_type_p (const_tree t)
2414 {
2415   /* This CONST_CAST is okay because strip_array_types returns its
2416      argument unmodified and we assign it to a const_tree.  */
2417   t = strip_array_types (CONST_CAST_TREE(t));
2418 
2419   if (!CLASS_TYPE_P (t))
2420     return scalarish_type_p (t);
2421   else if (cxx_dialect > cxx98)
2422     /* [class]/10: A POD struct is a class that is both a trivial class and a
2423        standard-layout class, and has no non-static data members of type
2424        non-POD struct, non-POD union (or array of such types).
2425 
2426        We don't need to check individual members because if a member is
2427        non-std-layout or non-trivial, the class will be too.  */
2428     return (std_layout_type_p (t) && trivial_type_p (t));
2429   else
2430     /* The C++98 definition of POD is different.  */
2431     return !CLASSTYPE_NON_LAYOUT_POD_P (t);
2432 }
2433 
2434 /* Returns true iff T is POD for the purpose of layout, as defined in the
2435    C++ ABI.  */
2436 
2437 bool
2438 layout_pod_type_p (const_tree t)
2439 {
2440   t = strip_array_types (CONST_CAST_TREE (t));
2441 
2442   if (CLASS_TYPE_P (t))
2443     return !CLASSTYPE_NON_LAYOUT_POD_P (t);
2444   else
2445     return scalarish_type_p (t);
2446 }
2447 
2448 /* Returns true iff T is a standard-layout type, as defined in
2449    [basic.types].  */
2450 
2451 bool
2452 std_layout_type_p (const_tree t)
2453 {
2454   t = strip_array_types (CONST_CAST_TREE (t));
2455 
2456   if (CLASS_TYPE_P (t))
2457     return !CLASSTYPE_NON_STD_LAYOUT (t);
2458   else
2459     return scalarish_type_p (t);
2460 }
2461 
2462 /* Nonzero iff type T is a class template implicit specialization.  */
2463 
2464 bool
2465 class_tmpl_impl_spec_p (const_tree t)
2466 {
2467   return CLASS_TYPE_P (t) && CLASSTYPE_TEMPLATE_INSTANTIATION (t);
2468 }
2469 
2470 /* Returns 1 iff zero initialization of type T means actually storing
2471    zeros in it.  */
2472 
2473 int
2474 zero_init_p (const_tree t)
2475 {
2476   /* This CONST_CAST is okay because strip_array_types returns its
2477      argument unmodified and we assign it to a const_tree.  */
2478   t = strip_array_types (CONST_CAST_TREE(t));
2479 
2480   if (t == error_mark_node)
2481     return 1;
2482 
2483   /* NULL pointers to data members are initialized with -1.  */
2484   if (TYPE_PTRMEM_P (t))
2485     return 0;
2486 
2487   /* Classes that contain types that can't be zero-initialized, cannot
2488      be zero-initialized themselves.  */
2489   if (CLASS_TYPE_P (t) && CLASSTYPE_NON_ZERO_INIT_P (t))
2490     return 0;
2491 
2492   return 1;
2493 }
2494 
2495 /* Table of valid C++ attributes.  */
2496 const struct attribute_spec cxx_attribute_table[] =
2497 {
2498   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
2499   { "java_interface", 0, 0, false, false, false, handle_java_interface_attribute },
2500   { "com_interface",  0, 0, false, false, false, handle_com_interface_attribute },
2501   { "init_priority",  1, 1, true,  false, false, handle_init_priority_attribute },
2502   { NULL,	      0, 0, false, false, false, NULL }
2503 };
2504 
2505 /* Handle a "java_interface" attribute; arguments as in
2506    struct attribute_spec.handler.  */
2507 static tree
2508 handle_java_interface_attribute (tree* node,
2509 				 tree name,
2510 				 tree args ATTRIBUTE_UNUSED ,
2511 				 int flags,
2512 				 bool* no_add_attrs)
2513 {
2514   if (DECL_P (*node)
2515       || !CLASS_TYPE_P (*node)
2516       || !TYPE_FOR_JAVA (*node))
2517     {
2518       error ("%qE attribute can only be applied to Java class definitions",
2519 	     name);
2520       *no_add_attrs = true;
2521       return NULL_TREE;
2522     }
2523   if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
2524     *node = build_variant_type_copy (*node);
2525   TYPE_JAVA_INTERFACE (*node) = 1;
2526 
2527   return NULL_TREE;
2528 }
2529 
2530 /* Handle a "com_interface" attribute; arguments as in
2531    struct attribute_spec.handler.  */
2532 static tree
2533 handle_com_interface_attribute (tree* node,
2534 				tree name,
2535 				tree args ATTRIBUTE_UNUSED ,
2536 				int flags ATTRIBUTE_UNUSED ,
2537 				bool* no_add_attrs)
2538 {
2539   static int warned;
2540 
2541   *no_add_attrs = true;
2542 
2543   if (DECL_P (*node)
2544       || !CLASS_TYPE_P (*node)
2545       || *node != TYPE_MAIN_VARIANT (*node))
2546     {
2547       warning (OPT_Wattributes, "%qE attribute can only be applied "
2548 	       "to class definitions", name);
2549       return NULL_TREE;
2550     }
2551 
2552   if (!warned++)
2553     warning (0, "%qE is obsolete; g++ vtables are now COM-compatible by default",
2554 	     name);
2555 
2556   return NULL_TREE;
2557 }
2558 
2559 /* Handle an "init_priority" attribute; arguments as in
2560    struct attribute_spec.handler.  */
2561 static tree
2562 handle_init_priority_attribute (tree* node,
2563 				tree name,
2564 				tree args,
2565 				int flags ATTRIBUTE_UNUSED ,
2566 				bool* no_add_attrs)
2567 {
2568   tree initp_expr = TREE_VALUE (args);
2569   tree decl = *node;
2570   tree type = TREE_TYPE (decl);
2571   int pri;
2572 
2573   STRIP_NOPS (initp_expr);
2574 
2575   if (!initp_expr || TREE_CODE (initp_expr) != INTEGER_CST)
2576     {
2577       error ("requested init_priority is not an integer constant");
2578       *no_add_attrs = true;
2579       return NULL_TREE;
2580     }
2581 
2582   pri = TREE_INT_CST_LOW (initp_expr);
2583 
2584   type = strip_array_types (type);
2585 
2586   if (decl == NULL_TREE
2587       || TREE_CODE (decl) != VAR_DECL
2588       || !TREE_STATIC (decl)
2589       || DECL_EXTERNAL (decl)
2590       || (TREE_CODE (type) != RECORD_TYPE
2591 	  && TREE_CODE (type) != UNION_TYPE)
2592       /* Static objects in functions are initialized the
2593 	 first time control passes through that
2594 	 function. This is not precise enough to pin down an
2595 	 init_priority value, so don't allow it.  */
2596       || current_function_decl)
2597     {
2598       error ("can only use %qE attribute on file-scope definitions "
2599 	     "of objects of class type", name);
2600       *no_add_attrs = true;
2601       return NULL_TREE;
2602     }
2603 
2604   if (pri > MAX_INIT_PRIORITY || pri <= 0)
2605     {
2606       error ("requested init_priority is out of range");
2607       *no_add_attrs = true;
2608       return NULL_TREE;
2609     }
2610 
2611   /* Check for init_priorities that are reserved for
2612      language and runtime support implementations.*/
2613   if (pri <= MAX_RESERVED_INIT_PRIORITY)
2614     {
2615       warning
2616 	(0, "requested init_priority is reserved for internal use");
2617     }
2618 
2619   if (SUPPORTS_INIT_PRIORITY)
2620     {
2621       SET_DECL_INIT_PRIORITY (decl, pri);
2622       DECL_HAS_INIT_PRIORITY_P (decl) = 1;
2623       return NULL_TREE;
2624     }
2625   else
2626     {
2627       error ("%qE attribute is not supported on this platform", name);
2628       *no_add_attrs = true;
2629       return NULL_TREE;
2630     }
2631 }
2632 
2633 /* Return a new PTRMEM_CST of the indicated TYPE.  The MEMBER is the
2634    thing pointed to by the constant.  */
2635 
2636 tree
2637 make_ptrmem_cst (tree type, tree member)
2638 {
2639   tree ptrmem_cst = make_node (PTRMEM_CST);
2640   TREE_TYPE (ptrmem_cst) = type;
2641   PTRMEM_CST_MEMBER (ptrmem_cst) = member;
2642   return ptrmem_cst;
2643 }
2644 
2645 /* Build a variant of TYPE that has the indicated ATTRIBUTES.  May
2646    return an existing type if an appropriate type already exists.  */
2647 
2648 tree
2649 cp_build_type_attribute_variant (tree type, tree attributes)
2650 {
2651   tree new_type;
2652 
2653   new_type = build_type_attribute_variant (type, attributes);
2654   if ((TREE_CODE (new_type) == FUNCTION_TYPE
2655        || TREE_CODE (new_type) == METHOD_TYPE)
2656       && (TYPE_RAISES_EXCEPTIONS (new_type)
2657 	  != TYPE_RAISES_EXCEPTIONS (type)))
2658     new_type = build_exception_variant (new_type,
2659 					TYPE_RAISES_EXCEPTIONS (type));
2660 
2661   /* Making a new main variant of a class type is broken.  */
2662   gcc_assert (!CLASS_TYPE_P (type) || new_type == type);
2663 
2664   return new_type;
2665 }
2666 
2667 /* Return TRUE if TYPE1 and TYPE2 are identical for type hashing purposes.
2668    Called only after doing all language independent checks.  Only
2669    to check TYPE_RAISES_EXCEPTIONS for FUNCTION_TYPE, the rest is already
2670    compared in type_hash_eq.  */
2671 
2672 bool
2673 cxx_type_hash_eq (const_tree typea, const_tree typeb)
2674 {
2675   gcc_assert (TREE_CODE (typea) == FUNCTION_TYPE);
2676 
2677   return comp_except_specs (TYPE_RAISES_EXCEPTIONS (typea),
2678 			    TYPE_RAISES_EXCEPTIONS (typeb), 1);
2679 }
2680 
2681 /* Apply FUNC to all language-specific sub-trees of TP in a pre-order
2682    traversal.  Called from walk_tree.  */
2683 
2684 tree
2685 cp_walk_subtrees (tree *tp, int *walk_subtrees_p, walk_tree_fn func,
2686 		  void *data, struct pointer_set_t *pset)
2687 {
2688   enum tree_code code = TREE_CODE (*tp);
2689   tree result;
2690 
2691 #define WALK_SUBTREE(NODE)				\
2692   do							\
2693     {							\
2694       result = cp_walk_tree (&(NODE), func, data, pset);	\
2695       if (result) goto out;				\
2696     }							\
2697   while (0)
2698 
2699   /* Not one of the easy cases.  We must explicitly go through the
2700      children.  */
2701   result = NULL_TREE;
2702   switch (code)
2703     {
2704     case DEFAULT_ARG:
2705     case TEMPLATE_TEMPLATE_PARM:
2706     case BOUND_TEMPLATE_TEMPLATE_PARM:
2707     case UNBOUND_CLASS_TEMPLATE:
2708     case TEMPLATE_PARM_INDEX:
2709     case TEMPLATE_TYPE_PARM:
2710     case TYPENAME_TYPE:
2711     case TYPEOF_TYPE:
2712       /* None of these have subtrees other than those already walked
2713 	 above.  */
2714       *walk_subtrees_p = 0;
2715       break;
2716 
2717     case BASELINK:
2718       WALK_SUBTREE (BASELINK_FUNCTIONS (*tp));
2719       *walk_subtrees_p = 0;
2720       break;
2721 
2722     case PTRMEM_CST:
2723       WALK_SUBTREE (TREE_TYPE (*tp));
2724       *walk_subtrees_p = 0;
2725       break;
2726 
2727     case TREE_LIST:
2728       WALK_SUBTREE (TREE_PURPOSE (*tp));
2729       break;
2730 
2731     case OVERLOAD:
2732       WALK_SUBTREE (OVL_FUNCTION (*tp));
2733       WALK_SUBTREE (OVL_CHAIN (*tp));
2734       *walk_subtrees_p = 0;
2735       break;
2736 
2737     case USING_DECL:
2738       WALK_SUBTREE (DECL_NAME (*tp));
2739       WALK_SUBTREE (USING_DECL_SCOPE (*tp));
2740       WALK_SUBTREE (USING_DECL_DECLS (*tp));
2741       *walk_subtrees_p = 0;
2742       break;
2743 
2744     case RECORD_TYPE:
2745       if (TYPE_PTRMEMFUNC_P (*tp))
2746 	WALK_SUBTREE (TYPE_PTRMEMFUNC_FN_TYPE (*tp));
2747       break;
2748 
2749     case TYPE_ARGUMENT_PACK:
2750     case NONTYPE_ARGUMENT_PACK:
2751       {
2752         tree args = ARGUMENT_PACK_ARGS (*tp);
2753         int i, len = TREE_VEC_LENGTH (args);
2754         for (i = 0; i < len; i++)
2755           WALK_SUBTREE (TREE_VEC_ELT (args, i));
2756       }
2757       break;
2758 
2759     case TYPE_PACK_EXPANSION:
2760       WALK_SUBTREE (TREE_TYPE (*tp));
2761       *walk_subtrees_p = 0;
2762       break;
2763 
2764     case EXPR_PACK_EXPANSION:
2765       WALK_SUBTREE (TREE_OPERAND (*tp, 0));
2766       *walk_subtrees_p = 0;
2767       break;
2768 
2769     case CAST_EXPR:
2770     case REINTERPRET_CAST_EXPR:
2771     case STATIC_CAST_EXPR:
2772     case CONST_CAST_EXPR:
2773     case DYNAMIC_CAST_EXPR:
2774       if (TREE_TYPE (*tp))
2775 	WALK_SUBTREE (TREE_TYPE (*tp));
2776 
2777       {
2778         int i;
2779         for (i = 0; i < TREE_CODE_LENGTH (TREE_CODE (*tp)); ++i)
2780 	  WALK_SUBTREE (TREE_OPERAND (*tp, i));
2781       }
2782       *walk_subtrees_p = 0;
2783       break;
2784 
2785     case TRAIT_EXPR:
2786       WALK_SUBTREE (TRAIT_EXPR_TYPE1 (*tp));
2787       WALK_SUBTREE (TRAIT_EXPR_TYPE2 (*tp));
2788       *walk_subtrees_p = 0;
2789       break;
2790 
2791     case DECLTYPE_TYPE:
2792       WALK_SUBTREE (DECLTYPE_TYPE_EXPR (*tp));
2793       *walk_subtrees_p = 0;
2794       break;
2795 
2796 
2797     default:
2798       return NULL_TREE;
2799     }
2800 
2801   /* We didn't find what we were looking for.  */
2802  out:
2803   return result;
2804 
2805 #undef WALK_SUBTREE
2806 }
2807 
2808 /* Like save_expr, but for C++.  */
2809 
2810 tree
2811 cp_save_expr (tree expr)
2812 {
2813   /* There is no reason to create a SAVE_EXPR within a template; if
2814      needed, we can create the SAVE_EXPR when instantiating the
2815      template.  Furthermore, the middle-end cannot handle C++-specific
2816      tree codes.  */
2817   if (processing_template_decl)
2818     return expr;
2819   return save_expr (expr);
2820 }
2821 
2822 /* Initialize tree.c.  */
2823 
2824 void
2825 init_tree (void)
2826 {
2827   list_hash_table = htab_create_ggc (31, list_hash, list_hash_eq, NULL);
2828 }
2829 
2830 /* Returns the kind of special function that DECL (a FUNCTION_DECL)
2831    is.  Note that sfk_none is zero, so this function can be used as a
2832    predicate to test whether or not DECL is a special function.  */
2833 
2834 special_function_kind
2835 special_function_p (const_tree decl)
2836 {
2837   /* Rather than doing all this stuff with magic names, we should
2838      probably have a field of type `special_function_kind' in
2839      DECL_LANG_SPECIFIC.  */
2840   if (DECL_COPY_CONSTRUCTOR_P (decl))
2841     return sfk_copy_constructor;
2842   if (DECL_MOVE_CONSTRUCTOR_P (decl))
2843     return sfk_move_constructor;
2844   if (DECL_CONSTRUCTOR_P (decl))
2845     return sfk_constructor;
2846   if (DECL_OVERLOADED_OPERATOR_P (decl) == NOP_EXPR)
2847     return sfk_assignment_operator;
2848   if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (decl))
2849     return sfk_destructor;
2850   if (DECL_COMPLETE_DESTRUCTOR_P (decl))
2851     return sfk_complete_destructor;
2852   if (DECL_BASE_DESTRUCTOR_P (decl))
2853     return sfk_base_destructor;
2854   if (DECL_DELETING_DESTRUCTOR_P (decl))
2855     return sfk_deleting_destructor;
2856   if (DECL_CONV_FN_P (decl))
2857     return sfk_conversion;
2858 
2859   return sfk_none;
2860 }
2861 
2862 /* Returns nonzero if TYPE is a character type, including wchar_t.  */
2863 
2864 int
2865 char_type_p (tree type)
2866 {
2867   return (same_type_p (type, char_type_node)
2868 	  || same_type_p (type, unsigned_char_type_node)
2869 	  || same_type_p (type, signed_char_type_node)
2870 	  || same_type_p (type, char16_type_node)
2871 	  || same_type_p (type, char32_type_node)
2872 	  || same_type_p (type, wchar_type_node));
2873 }
2874 
2875 /* Returns the kind of linkage associated with the indicated DECL.  Th
2876    value returned is as specified by the language standard; it is
2877    independent of implementation details regarding template
2878    instantiation, etc.  For example, it is possible that a declaration
2879    to which this function assigns external linkage would not show up
2880    as a global symbol when you run `nm' on the resulting object file.  */
2881 
2882 linkage_kind
2883 decl_linkage (tree decl)
2884 {
2885   /* This function doesn't attempt to calculate the linkage from first
2886      principles as given in [basic.link].  Instead, it makes use of
2887      the fact that we have already set TREE_PUBLIC appropriately, and
2888      then handles a few special cases.  Ideally, we would calculate
2889      linkage first, and then transform that into a concrete
2890      implementation.  */
2891 
2892   /* Things that don't have names have no linkage.  */
2893   if (!DECL_NAME (decl))
2894     return lk_none;
2895 
2896   /* Fields have no linkage.  */
2897   if (TREE_CODE (decl) == FIELD_DECL)
2898     return lk_none;
2899 
2900   /* Things that are TREE_PUBLIC have external linkage.  */
2901   if (TREE_PUBLIC (decl))
2902     return lk_external;
2903 
2904   if (TREE_CODE (decl) == NAMESPACE_DECL)
2905     return lk_external;
2906 
2907   /* Linkage of a CONST_DECL depends on the linkage of the enumeration
2908      type.  */
2909   if (TREE_CODE (decl) == CONST_DECL)
2910     return decl_linkage (TYPE_NAME (TREE_TYPE (decl)));
2911 
2912   /* Some things that are not TREE_PUBLIC have external linkage, too.
2913      For example, on targets that don't have weak symbols, we make all
2914      template instantiations have internal linkage (in the object
2915      file), but the symbols should still be treated as having external
2916      linkage from the point of view of the language.  */
2917   if ((TREE_CODE (decl) == FUNCTION_DECL
2918        || TREE_CODE (decl) == VAR_DECL)
2919       && DECL_COMDAT (decl))
2920     return lk_external;
2921 
2922   /* Things in local scope do not have linkage, if they don't have
2923      TREE_PUBLIC set.  */
2924   if (decl_function_context (decl))
2925     return lk_none;
2926 
2927   /* Members of the anonymous namespace also have TREE_PUBLIC unset, but
2928      are considered to have external linkage for language purposes.  DECLs
2929      really meant to have internal linkage have DECL_THIS_STATIC set.  */
2930   if (TREE_CODE (decl) == TYPE_DECL)
2931     return lk_external;
2932   if (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == FUNCTION_DECL)
2933     {
2934       if (!DECL_THIS_STATIC (decl))
2935 	return lk_external;
2936 
2937       /* Static data members and static member functions from classes
2938 	 in anonymous namespace also don't have TREE_PUBLIC set.  */
2939       if (DECL_CLASS_CONTEXT (decl))
2940 	return lk_external;
2941     }
2942 
2943   /* Everything else has internal linkage.  */
2944   return lk_internal;
2945 }
2946 
2947 /* EXP is an expression that we want to pre-evaluate.  Returns (in
2948    *INITP) an expression that will perform the pre-evaluation.  The
2949    value returned by this function is a side-effect free expression
2950    equivalent to the pre-evaluated expression.  Callers must ensure
2951    that *INITP is evaluated before EXP.  */
2952 
2953 tree
2954 stabilize_expr (tree exp, tree* initp)
2955 {
2956   tree init_expr;
2957 
2958   if (!TREE_SIDE_EFFECTS (exp))
2959     init_expr = NULL_TREE;
2960   else if (!real_lvalue_p (exp)
2961 	   || (!TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (exp))
2962 	       && !TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TREE_TYPE (exp))))
2963     {
2964       init_expr = get_target_expr (exp);
2965       exp = TARGET_EXPR_SLOT (init_expr);
2966     }
2967   else
2968     {
2969       exp = cp_build_unary_op (ADDR_EXPR, exp, 1, tf_warning_or_error);
2970       init_expr = get_target_expr (exp);
2971       exp = TARGET_EXPR_SLOT (init_expr);
2972       exp = cp_build_indirect_ref (exp, RO_NULL, tf_warning_or_error);
2973     }
2974   *initp = init_expr;
2975 
2976   gcc_assert (!TREE_SIDE_EFFECTS (exp));
2977   return exp;
2978 }
2979 
2980 /* Add NEW_EXPR, an expression whose value we don't care about, after the
2981    similar expression ORIG.  */
2982 
2983 tree
2984 add_stmt_to_compound (tree orig, tree new_expr)
2985 {
2986   if (!new_expr || !TREE_SIDE_EFFECTS (new_expr))
2987     return orig;
2988   if (!orig || !TREE_SIDE_EFFECTS (orig))
2989     return new_expr;
2990   return build2 (COMPOUND_EXPR, void_type_node, orig, new_expr);
2991 }
2992 
2993 /* Like stabilize_expr, but for a call whose arguments we want to
2994    pre-evaluate.  CALL is modified in place to use the pre-evaluated
2995    arguments, while, upon return, *INITP contains an expression to
2996    compute the arguments.  */
2997 
2998 void
2999 stabilize_call (tree call, tree *initp)
3000 {
3001   tree inits = NULL_TREE;
3002   int i;
3003   int nargs = call_expr_nargs (call);
3004 
3005   if (call == error_mark_node || processing_template_decl)
3006     {
3007       *initp = NULL_TREE;
3008       return;
3009     }
3010 
3011   gcc_assert (TREE_CODE (call) == CALL_EXPR);
3012 
3013   for (i = 0; i < nargs; i++)
3014     {
3015       tree init;
3016       CALL_EXPR_ARG (call, i) =
3017 	stabilize_expr (CALL_EXPR_ARG (call, i), &init);
3018       inits = add_stmt_to_compound (inits, init);
3019     }
3020 
3021   *initp = inits;
3022 }
3023 
3024 /* Like stabilize_expr, but for an AGGR_INIT_EXPR whose arguments we want
3025    to pre-evaluate.  CALL is modified in place to use the pre-evaluated
3026    arguments, while, upon return, *INITP contains an expression to
3027    compute the arguments.  */
3028 
3029 void
3030 stabilize_aggr_init (tree call, tree *initp)
3031 {
3032   tree inits = NULL_TREE;
3033   int i;
3034   int nargs = aggr_init_expr_nargs (call);
3035 
3036   if (call == error_mark_node)
3037     return;
3038 
3039   gcc_assert (TREE_CODE (call) == AGGR_INIT_EXPR);
3040 
3041   for (i = 0; i < nargs; i++)
3042     {
3043       tree init;
3044       AGGR_INIT_EXPR_ARG (call, i) =
3045 	stabilize_expr (AGGR_INIT_EXPR_ARG (call, i), &init);
3046       inits = add_stmt_to_compound (inits, init);
3047     }
3048 
3049   *initp = inits;
3050 }
3051 
3052 /* Like stabilize_expr, but for an initialization.
3053 
3054    If the initialization is for an object of class type, this function
3055    takes care not to introduce additional temporaries.
3056 
3057    Returns TRUE iff the expression was successfully pre-evaluated,
3058    i.e., if INIT is now side-effect free, except for, possible, a
3059    single call to a constructor.  */
3060 
3061 bool
3062 stabilize_init (tree init, tree *initp)
3063 {
3064   tree t = init;
3065 
3066   *initp = NULL_TREE;
3067 
3068   if (t == error_mark_node || processing_template_decl)
3069     return true;
3070 
3071   if (TREE_CODE (t) == INIT_EXPR
3072       && TREE_CODE (TREE_OPERAND (t, 1)) != TARGET_EXPR
3073       && TREE_CODE (TREE_OPERAND (t, 1)) != AGGR_INIT_EXPR)
3074     {
3075       TREE_OPERAND (t, 1) = stabilize_expr (TREE_OPERAND (t, 1), initp);
3076       return true;
3077     }
3078 
3079   if (TREE_CODE (t) == INIT_EXPR)
3080     t = TREE_OPERAND (t, 1);
3081   if (TREE_CODE (t) == TARGET_EXPR)
3082     t = TARGET_EXPR_INITIAL (t);
3083   if (TREE_CODE (t) == COMPOUND_EXPR)
3084     t = expr_last (t);
3085   if (TREE_CODE (t) == CONSTRUCTOR
3086       && EMPTY_CONSTRUCTOR_P (t))
3087     /* Default-initialization.  */
3088     return true;
3089 
3090   /* If the initializer is a COND_EXPR, we can't preevaluate
3091      anything.  */
3092   if (TREE_CODE (t) == COND_EXPR)
3093     return false;
3094 
3095   if (TREE_CODE (t) == CALL_EXPR)
3096     {
3097       stabilize_call (t, initp);
3098       return true;
3099     }
3100 
3101   if (TREE_CODE (t) == AGGR_INIT_EXPR)
3102     {
3103       stabilize_aggr_init (t, initp);
3104       return true;
3105     }
3106 
3107   /* The initialization is being performed via a bitwise copy -- and
3108      the item copied may have side effects.  */
3109   return TREE_SIDE_EFFECTS (init);
3110 }
3111 
3112 /* Like "fold", but should be used whenever we might be processing the
3113    body of a template.  */
3114 
3115 tree
3116 fold_if_not_in_template (tree expr)
3117 {
3118   /* In the body of a template, there is never any need to call
3119      "fold".  We will call fold later when actually instantiating the
3120      template.  Integral constant expressions in templates will be
3121      evaluated via fold_non_dependent_expr, as necessary.  */
3122   if (processing_template_decl)
3123     return expr;
3124 
3125   /* Fold C++ front-end specific tree codes.  */
3126   if (TREE_CODE (expr) == UNARY_PLUS_EXPR)
3127     return fold_convert (TREE_TYPE (expr), TREE_OPERAND (expr, 0));
3128 
3129   return fold (expr);
3130 }
3131 
3132 /* Returns true if a cast to TYPE may appear in an integral constant
3133    expression.  */
3134 
3135 bool
3136 cast_valid_in_integral_constant_expression_p (tree type)
3137 {
3138   return (INTEGRAL_OR_ENUMERATION_TYPE_P (type)
3139 	  || dependent_type_p (type)
3140 	  || type == error_mark_node);
3141 }
3142 
3143 /* Return true if we need to fix linkage information of DECL.  */
3144 
3145 static bool
3146 cp_fix_function_decl_p (tree decl)
3147 {
3148   /* Skip if DECL is not externally visible.  */
3149   if (!TREE_PUBLIC (decl))
3150     return false;
3151 
3152   /* We need to fix DECL if it a appears to be exported but with no
3153      function body.  Thunks do not have CFGs and we may need to
3154      handle them specially later.   */
3155   if (!gimple_has_body_p (decl)
3156       && !DECL_THUNK_P (decl)
3157       && !DECL_EXTERNAL (decl))
3158     {
3159       struct cgraph_node *node = cgraph_get_node (decl);
3160 
3161       /* Don't fix same_body aliases.  Although they don't have their own
3162 	 CFG, they share it with what they alias to.  */
3163       if (!node
3164 	  || node->decl == decl
3165 	  || !node->same_body)
3166 	return true;
3167     }
3168 
3169   return false;
3170 }
3171 
3172 /* Clean the C++ specific parts of the tree T. */
3173 
3174 void
3175 cp_free_lang_data (tree t)
3176 {
3177   if (TREE_CODE (t) == METHOD_TYPE
3178       || TREE_CODE (t) == FUNCTION_TYPE)
3179     {
3180       /* Default args are not interesting anymore.  */
3181       tree argtypes = TYPE_ARG_TYPES (t);
3182       while (argtypes)
3183         {
3184 	  TREE_PURPOSE (argtypes) = 0;
3185 	  argtypes = TREE_CHAIN (argtypes);
3186 	}
3187     }
3188   else if (TREE_CODE (t) == FUNCTION_DECL
3189 	   && cp_fix_function_decl_p (t))
3190     {
3191       /* If T is used in this translation unit at all,  the definition
3192 	 must exist somewhere else since we have decided to not emit it
3193 	 in this TU.  So make it an external reference.  */
3194       DECL_EXTERNAL (t) = 1;
3195       TREE_STATIC (t) = 0;
3196     }
3197   if (CP_AGGREGATE_TYPE_P (t)
3198       && TYPE_NAME (t))
3199     {
3200       tree name = TYPE_NAME (t);
3201       if (TREE_CODE (name) == TYPE_DECL)
3202 	name = DECL_NAME (name);
3203       /* Drop anonymous names.  */
3204       if (name != NULL_TREE
3205 	  && ANON_AGGRNAME_P (name))
3206 	TYPE_NAME (t) = NULL_TREE;
3207     }
3208 }
3209 
3210 
3211 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
3212 /* Complain that some language-specific thing hanging off a tree
3213    node has been accessed improperly.  */
3214 
3215 void
3216 lang_check_failed (const char* file, int line, const char* function)
3217 {
3218   internal_error ("lang_* check: failed in %s, at %s:%d",
3219 		  function, trim_filename (file), line);
3220 }
3221 #endif /* ENABLE_TREE_CHECKING */
3222 
3223 #include "gt-cp-tree.h"
3224