xref: /dragonfly/contrib/gcc-4.7/gcc/cp/mangle.c (revision 25a2db75)
1 /* Name mangling for the 3.0 C++ ABI.
2    Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010,
3    2011  Free Software Foundation, Inc.
4    Written by Alex Samuel <samuel@codesourcery.com>
5 
6    This file is part of GCC.
7 
8    GCC is free software; you can redistribute it and/or modify it
9    under the terms of the GNU General Public License as published by
10    the Free Software Foundation; either version 3, or (at your option)
11    any later version.
12 
13    GCC is distributed in the hope that it will be useful, but
14    WITHOUT ANY WARRANTY; without even the implied warranty of
15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16    General Public License for more details.
17 
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3.  If not see
20 <http://www.gnu.org/licenses/>.  */
21 
22 /* This file implements mangling of C++ names according to the IA64
23    C++ ABI specification.  A mangled name encodes a function or
24    variable's name, scope, type, and/or template arguments into a text
25    identifier.  This identifier is used as the function's or
26    variable's linkage name, to preserve compatibility between C++'s
27    language features (templates, scoping, and overloading) and C
28    linkers.
29 
30    Additionally, g++ uses mangled names internally.  To support this,
31    mangling of types is allowed, even though the mangled name of a
32    type should not appear by itself as an exported name.  Ditto for
33    uninstantiated templates.
34 
35    The primary entry point for this module is mangle_decl, which
36    returns an identifier containing the mangled name for a decl.
37    Additional entry points are provided to build mangled names of
38    particular constructs when the appropriate decl for that construct
39    is not available.  These are:
40 
41      mangle_typeinfo_for_type:		typeinfo data
42      mangle_typeinfo_string_for_type:	typeinfo type name
43      mangle_vtbl_for_type:		virtual table data
44      mangle_vtt_for_type:		VTT data
45      mangle_ctor_vtbl_for_type:		`C-in-B' constructor virtual table data
46      mangle_thunk:			thunk function or entry  */
47 
48 #include "config.h"
49 #include "system.h"
50 #include "coretypes.h"
51 #include "tm.h"
52 #include "tree.h"
53 #include "tm_p.h"
54 #include "cp-tree.h"
55 #include "obstack.h"
56 #include "flags.h"
57 #include "target.h"
58 #include "cgraph.h"
59 
60 /* Debugging support.  */
61 
62 /* Define DEBUG_MANGLE to enable very verbose trace messages.  */
63 #ifndef DEBUG_MANGLE
64 #define DEBUG_MANGLE 0
65 #endif
66 
67 /* Macros for tracing the write_* functions.  */
68 #if DEBUG_MANGLE
69 # define MANGLE_TRACE(FN, INPUT) \
70   fprintf (stderr, "  %-24s: %-24s\n", (FN), (INPUT))
71 # define MANGLE_TRACE_TREE(FN, NODE) \
72   fprintf (stderr, "  %-24s: %-24s (%p)\n", \
73 	   (FN), tree_code_name[TREE_CODE (NODE)], (void *) (NODE))
74 #else
75 # define MANGLE_TRACE(FN, INPUT)
76 # define MANGLE_TRACE_TREE(FN, NODE)
77 #endif
78 
79 /* Nonzero if NODE is a class template-id.  We can't rely on
80    CLASSTYPE_USE_TEMPLATE here because of tricky bugs in the parser
81    that hard to distinguish A<T> from A, where A<T> is the type as
82    instantiated outside of the template, and A is the type used
83    without parameters inside the template.  */
84 #define CLASSTYPE_TEMPLATE_ID_P(NODE)					\
85   (TYPE_LANG_SPECIFIC (NODE) != NULL					\
86    && (TREE_CODE (NODE) == BOUND_TEMPLATE_TEMPLATE_PARM			\
87        || (CLASSTYPE_TEMPLATE_INFO (NODE) != NULL			\
88 	   && (PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (NODE))))))
89 
90 /* Things we only need one of.  This module is not reentrant.  */
91 typedef struct GTY(()) globals {
92   /* An array of the current substitution candidates, in the order
93      we've seen them.  */
94   VEC(tree,gc) *substitutions;
95 
96   /* The entity that is being mangled.  */
97   tree GTY ((skip)) entity;
98 
99   /* How many parameter scopes we are inside.  */
100   int parm_depth;
101 
102   /* True if the mangling will be different in a future version of the
103      ABI.  */
104   bool need_abi_warning;
105 } globals;
106 
107 static GTY (()) globals G;
108 
109 /* The obstack on which we build mangled names.  */
110 static struct obstack *mangle_obstack;
111 
112 /* The obstack on which we build mangled names that are not going to
113    be IDENTIFIER_NODEs.  */
114 static struct obstack name_obstack;
115 
116 /* The first object on the name_obstack; we use this to free memory
117    allocated on the name_obstack.  */
118 static void *name_base;
119 
120 /* Indices into subst_identifiers.  These are identifiers used in
121    special substitution rules.  */
122 typedef enum
123 {
124   SUBID_ALLOCATOR,
125   SUBID_BASIC_STRING,
126   SUBID_CHAR_TRAITS,
127   SUBID_BASIC_ISTREAM,
128   SUBID_BASIC_OSTREAM,
129   SUBID_BASIC_IOSTREAM,
130   SUBID_MAX
131 }
132 substitution_identifier_index_t;
133 
134 /* For quick substitution checks, look up these common identifiers
135    once only.  */
136 static GTY(()) tree subst_identifiers[SUBID_MAX];
137 
138 /* Single-letter codes for builtin integer types, defined in
139    <builtin-type>.  These are indexed by integer_type_kind values.  */
140 static const char
141 integer_type_codes[itk_none] =
142 {
143   'c',  /* itk_char */
144   'a',  /* itk_signed_char */
145   'h',  /* itk_unsigned_char */
146   's',  /* itk_short */
147   't',  /* itk_unsigned_short */
148   'i',  /* itk_int */
149   'j',  /* itk_unsigned_int */
150   'l',  /* itk_long */
151   'm',  /* itk_unsigned_long */
152   'x',  /* itk_long_long */
153   'y',  /* itk_unsigned_long_long */
154   'n',  /* itk_int128 */
155   'o',  /* itk_unsigned_int128  */
156 };
157 
158 static int decl_is_template_id (const tree, tree* const);
159 
160 /* Functions for handling substitutions.  */
161 
162 static inline tree canonicalize_for_substitution (tree);
163 static void add_substitution (tree);
164 static inline int is_std_substitution (const tree,
165 				       const substitution_identifier_index_t);
166 static inline int is_std_substitution_char (const tree,
167 					    const substitution_identifier_index_t);
168 static int find_substitution (tree);
169 static void mangle_call_offset (const tree, const tree);
170 
171 /* Functions for emitting mangled representations of things.  */
172 
173 static void write_mangled_name (const tree, bool);
174 static void write_encoding (const tree);
175 static void write_name (tree, const int);
176 static void write_unscoped_name (const tree);
177 static void write_unscoped_template_name (const tree);
178 static void write_nested_name (const tree);
179 static void write_prefix (const tree);
180 static void write_template_prefix (const tree);
181 static void write_unqualified_name (const tree);
182 static void write_conversion_operator_name (const tree);
183 static void write_source_name (tree);
184 static void write_literal_operator_name (tree);
185 static void write_unnamed_type_name (const tree);
186 static void write_closure_type_name (const tree);
187 static int hwint_to_ascii (unsigned HOST_WIDE_INT, const unsigned int, char *,
188 			   const unsigned int);
189 static void write_number (unsigned HOST_WIDE_INT, const int,
190 			  const unsigned int);
191 static void write_compact_number (int num);
192 static void write_integer_cst (const tree);
193 static void write_real_cst (const tree);
194 static void write_identifier (const char *);
195 static void write_special_name_constructor (const tree);
196 static void write_special_name_destructor (const tree);
197 static void write_type (tree);
198 static int write_CV_qualifiers_for_type (const tree);
199 static void write_builtin_type (tree);
200 static void write_function_type (const tree);
201 static void write_bare_function_type (const tree, const int, const tree);
202 static void write_method_parms (tree, const int, const tree);
203 static void write_class_enum_type (const tree);
204 static void write_template_args (tree);
205 static void write_expression (tree);
206 static void write_template_arg_literal (const tree);
207 static void write_template_arg (tree);
208 static void write_template_template_arg (const tree);
209 static void write_array_type (const tree);
210 static void write_pointer_to_member_type (const tree);
211 static void write_template_param (const tree);
212 static void write_template_template_param (const tree);
213 static void write_substitution (const int);
214 static int discriminator_for_local_entity (tree);
215 static int discriminator_for_string_literal (tree, tree);
216 static void write_discriminator (const int);
217 static void write_local_name (tree, const tree, const tree);
218 static void dump_substitution_candidates (void);
219 static tree mangle_decl_string (const tree);
220 static int local_class_index (tree);
221 
222 /* Control functions.  */
223 
224 static inline void start_mangling (const tree);
225 static inline const char *finish_mangling (const bool);
226 static tree mangle_special_for_type (const tree, const char *);
227 
228 /* Foreign language functions.  */
229 
230 static void write_java_integer_type_codes (const tree);
231 
232 /* Append a single character to the end of the mangled
233    representation.  */
234 #define write_char(CHAR)						\
235   obstack_1grow (mangle_obstack, (CHAR))
236 
237 /* Append a sized buffer to the end of the mangled representation.  */
238 #define write_chars(CHAR, LEN)						\
239   obstack_grow (mangle_obstack, (CHAR), (LEN))
240 
241 /* Append a NUL-terminated string to the end of the mangled
242    representation.  */
243 #define write_string(STRING)						\
244   obstack_grow (mangle_obstack, (STRING), strlen (STRING))
245 
246 /* Nonzero if NODE1 and NODE2 are both TREE_LIST nodes and have the
247    same purpose (context, which may be a type) and value (template
248    decl).  See write_template_prefix for more information on what this
249    is used for.  */
250 #define NESTED_TEMPLATE_MATCH(NODE1, NODE2)				\
251   (TREE_CODE (NODE1) == TREE_LIST					\
252    && TREE_CODE (NODE2) == TREE_LIST					\
253    && ((TYPE_P (TREE_PURPOSE (NODE1))					\
254 	&& same_type_p (TREE_PURPOSE (NODE1), TREE_PURPOSE (NODE2)))	\
255        || TREE_PURPOSE (NODE1) == TREE_PURPOSE (NODE2))			\
256    && TREE_VALUE (NODE1) == TREE_VALUE (NODE2))
257 
258 /* Write out an unsigned quantity in base 10.  */
259 #define write_unsigned_number(NUMBER)					\
260   write_number ((NUMBER), /*unsigned_p=*/1, 10)
261 
262 /* If DECL is a template instance, return nonzero and, if
263    TEMPLATE_INFO is non-NULL, set *TEMPLATE_INFO to its template info.
264    Otherwise return zero.  */
265 
266 static int
267 decl_is_template_id (const tree decl, tree* const template_info)
268 {
269   if (TREE_CODE (decl) == TYPE_DECL)
270     {
271       /* TYPE_DECLs are handled specially.  Look at its type to decide
272 	 if this is a template instantiation.  */
273       const tree type = TREE_TYPE (decl);
274 
275       if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_ID_P (type))
276 	{
277 	  if (template_info != NULL)
278 	    /* For a templated TYPE_DECL, the template info is hanging
279 	       off the type.  */
280 	    *template_info = TYPE_TEMPLATE_INFO (type);
281 	  return 1;
282 	}
283     }
284   else
285     {
286       /* Check if this is a primary template.  */
287       if (DECL_LANG_SPECIFIC (decl) != NULL
288 	  && DECL_USE_TEMPLATE (decl)
289 	  && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl))
290 	  && TREE_CODE (decl) != TEMPLATE_DECL)
291 	{
292 	  if (template_info != NULL)
293 	    /* For most templated decls, the template info is hanging
294 	       off the decl.  */
295 	    *template_info = DECL_TEMPLATE_INFO (decl);
296 	  return 1;
297 	}
298     }
299 
300   /* It's not a template id.  */
301   return 0;
302 }
303 
304 /* Produce debugging output of current substitution candidates.  */
305 
306 static void
307 dump_substitution_candidates (void)
308 {
309   unsigned i;
310   tree el;
311 
312   fprintf (stderr, "  ++ substitutions  ");
313   FOR_EACH_VEC_ELT (tree, G.substitutions, i, el)
314     {
315       const char *name = "???";
316 
317       if (i > 0)
318 	fprintf (stderr, "                    ");
319       if (DECL_P (el))
320 	name = IDENTIFIER_POINTER (DECL_NAME (el));
321       else if (TREE_CODE (el) == TREE_LIST)
322 	name = IDENTIFIER_POINTER (DECL_NAME (TREE_VALUE (el)));
323       else if (TYPE_NAME (el))
324 	name = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (el)));
325       fprintf (stderr, " S%d_ = ", i - 1);
326       if (TYPE_P (el) &&
327 	  (CP_TYPE_RESTRICT_P (el)
328 	   || CP_TYPE_VOLATILE_P (el)
329 	   || CP_TYPE_CONST_P (el)))
330 	fprintf (stderr, "CV-");
331       fprintf (stderr, "%s (%s at %p)\n",
332 	       name, tree_code_name[TREE_CODE (el)], (void *) el);
333     }
334 }
335 
336 /* Both decls and types can be substitution candidates, but sometimes
337    they refer to the same thing.  For instance, a TYPE_DECL and
338    RECORD_TYPE for the same class refer to the same thing, and should
339    be treated accordingly in substitutions.  This function returns a
340    canonicalized tree node representing NODE that is used when adding
341    and substitution candidates and finding matches.  */
342 
343 static inline tree
344 canonicalize_for_substitution (tree node)
345 {
346   /* For a TYPE_DECL, use the type instead.  */
347   if (TREE_CODE (node) == TYPE_DECL)
348     node = TREE_TYPE (node);
349   if (TYPE_P (node)
350       && TYPE_CANONICAL (node) != node
351       && TYPE_MAIN_VARIANT (node) != node)
352     {
353       /* Here we want to strip the topmost typedef only.
354          We need to do that so is_std_substitution can do proper
355          name matching.  */
356       if (TREE_CODE (node) == FUNCTION_TYPE)
357 	/* Use build_qualified_type and TYPE_QUALS here to preserve
358 	   the old buggy mangling of attribute noreturn with abi<5.  */
359 	node = build_qualified_type (TYPE_MAIN_VARIANT (node),
360 				     TYPE_QUALS (node));
361       else
362 	node = cp_build_qualified_type (TYPE_MAIN_VARIANT (node),
363 					cp_type_quals (node));
364     }
365   return node;
366 }
367 
368 /* Add NODE as a substitution candidate.  NODE must not already be on
369    the list of candidates.  */
370 
371 static void
372 add_substitution (tree node)
373 {
374   tree c;
375 
376   if (DEBUG_MANGLE)
377     fprintf (stderr, "  ++ add_substitution (%s at %10p)\n",
378 	     tree_code_name[TREE_CODE (node)], (void *) node);
379 
380   /* Get the canonicalized substitution candidate for NODE.  */
381   c = canonicalize_for_substitution (node);
382   if (DEBUG_MANGLE && c != node)
383     fprintf (stderr, "  ++ using candidate (%s at %10p)\n",
384 	     tree_code_name[TREE_CODE (node)], (void *) node);
385   node = c;
386 
387 #if ENABLE_CHECKING
388   /* Make sure NODE isn't already a candidate.  */
389   {
390     int i;
391     tree candidate;
392 
393     FOR_EACH_VEC_ELT (tree, G.substitutions, i, candidate)
394       {
395 	gcc_assert (!(DECL_P (node) && node == candidate));
396 	gcc_assert (!(TYPE_P (node) && TYPE_P (candidate)
397 		      && same_type_p (node, candidate)));
398       }
399   }
400 #endif /* ENABLE_CHECKING */
401 
402   /* Put the decl onto the varray of substitution candidates.  */
403   VEC_safe_push (tree, gc, G.substitutions, node);
404 
405   if (DEBUG_MANGLE)
406     dump_substitution_candidates ();
407 }
408 
409 /* Helper function for find_substitution.  Returns nonzero if NODE,
410    which may be a decl or a CLASS_TYPE, is a template-id with template
411    name of substitution_index[INDEX] in the ::std namespace.  */
412 
413 static inline int
414 is_std_substitution (const tree node,
415 		     const substitution_identifier_index_t index)
416 {
417   tree type = NULL;
418   tree decl = NULL;
419 
420   if (DECL_P (node))
421     {
422       type = TREE_TYPE (node);
423       decl = node;
424     }
425   else if (CLASS_TYPE_P (node))
426     {
427       type = node;
428       decl = TYPE_NAME (node);
429     }
430   else
431     /* These are not the droids you're looking for.  */
432     return 0;
433 
434   return (DECL_NAMESPACE_STD_P (CP_DECL_CONTEXT (decl))
435 	  && TYPE_LANG_SPECIFIC (type)
436 	  && TYPE_TEMPLATE_INFO (type)
437 	  && (DECL_NAME (TYPE_TI_TEMPLATE (type))
438 	      == subst_identifiers[index]));
439 }
440 
441 /* Helper function for find_substitution.  Returns nonzero if NODE,
442    which may be a decl or a CLASS_TYPE, is the template-id
443    ::std::identifier<char>, where identifier is
444    substitution_index[INDEX].  */
445 
446 static inline int
447 is_std_substitution_char (const tree node,
448 			  const substitution_identifier_index_t index)
449 {
450   tree args;
451   /* Check NODE's name is ::std::identifier.  */
452   if (!is_std_substitution (node, index))
453     return 0;
454   /* Figure out its template args.  */
455   if (DECL_P (node))
456     args = DECL_TI_ARGS (node);
457   else if (CLASS_TYPE_P (node))
458     args = CLASSTYPE_TI_ARGS (node);
459   else
460     /* Oops, not a template.  */
461     return 0;
462   /* NODE's template arg list should be <char>.  */
463   return
464     TREE_VEC_LENGTH (args) == 1
465     && TREE_VEC_ELT (args, 0) == char_type_node;
466 }
467 
468 /* Check whether a substitution should be used to represent NODE in
469    the mangling.
470 
471    First, check standard special-case substitutions.
472 
473      <substitution> ::= St
474 	 # ::std
475 
476 		    ::= Sa
477 	 # ::std::allocator
478 
479 		    ::= Sb
480 	 # ::std::basic_string
481 
482 		    ::= Ss
483 	 # ::std::basic_string<char,
484 			       ::std::char_traits<char>,
485 			       ::std::allocator<char> >
486 
487 		    ::= Si
488 	 # ::std::basic_istream<char, ::std::char_traits<char> >
489 
490 		    ::= So
491 	 # ::std::basic_ostream<char, ::std::char_traits<char> >
492 
493 		    ::= Sd
494 	 # ::std::basic_iostream<char, ::std::char_traits<char> >
495 
496    Then examine the stack of currently available substitution
497    candidates for entities appearing earlier in the same mangling
498 
499    If a substitution is found, write its mangled representation and
500    return nonzero.  If none is found, just return zero.  */
501 
502 static int
503 find_substitution (tree node)
504 {
505   int i;
506   const int size = VEC_length (tree, G.substitutions);
507   tree decl;
508   tree type;
509 
510   if (DEBUG_MANGLE)
511     fprintf (stderr, "  ++ find_substitution (%s at %p)\n",
512 	     tree_code_name[TREE_CODE (node)], (void *) node);
513 
514   /* Obtain the canonicalized substitution representation for NODE.
515      This is what we'll compare against.  */
516   node = canonicalize_for_substitution (node);
517 
518   /* Check for builtin substitutions.  */
519 
520   decl = TYPE_P (node) ? TYPE_NAME (node) : node;
521   type = TYPE_P (node) ? node : TREE_TYPE (node);
522 
523   /* Check for std::allocator.  */
524   if (decl
525       && is_std_substitution (decl, SUBID_ALLOCATOR)
526       && !CLASSTYPE_USE_TEMPLATE (TREE_TYPE (decl)))
527     {
528       write_string ("Sa");
529       return 1;
530     }
531 
532   /* Check for std::basic_string.  */
533   if (decl && is_std_substitution (decl, SUBID_BASIC_STRING))
534     {
535       if (TYPE_P (node))
536 	{
537 	  /* If this is a type (i.e. a fully-qualified template-id),
538 	     check for
539 		 std::basic_string <char,
540 				    std::char_traits<char>,
541 				    std::allocator<char> > .  */
542 	  if (cp_type_quals (type) == TYPE_UNQUALIFIED
543 	      && CLASSTYPE_USE_TEMPLATE (type))
544 	    {
545 	      tree args = CLASSTYPE_TI_ARGS (type);
546 	      if (TREE_VEC_LENGTH (args) == 3
547 		  && same_type_p (TREE_VEC_ELT (args, 0), char_type_node)
548 		  && is_std_substitution_char (TREE_VEC_ELT (args, 1),
549 					       SUBID_CHAR_TRAITS)
550 		  && is_std_substitution_char (TREE_VEC_ELT (args, 2),
551 					       SUBID_ALLOCATOR))
552 		{
553 		  write_string ("Ss");
554 		  return 1;
555 		}
556 	    }
557 	}
558       else
559 	/* Substitute for the template name only if this isn't a type.  */
560 	{
561 	  write_string ("Sb");
562 	  return 1;
563 	}
564     }
565 
566   /* Check for basic_{i,o,io}stream.  */
567   if (TYPE_P (node)
568       && cp_type_quals (type) == TYPE_UNQUALIFIED
569       && CLASS_TYPE_P (type)
570       && CLASSTYPE_USE_TEMPLATE (type)
571       && CLASSTYPE_TEMPLATE_INFO (type) != NULL)
572     {
573       /* First, check for the template
574 	 args <char, std::char_traits<char> > .  */
575       tree args = CLASSTYPE_TI_ARGS (type);
576       if (TREE_VEC_LENGTH (args) == 2
577 	  && TYPE_P (TREE_VEC_ELT (args, 0))
578 	  && same_type_p (TREE_VEC_ELT (args, 0), char_type_node)
579 	  && is_std_substitution_char (TREE_VEC_ELT (args, 1),
580 				       SUBID_CHAR_TRAITS))
581 	{
582 	  /* Got them.  Is this basic_istream?  */
583 	  if (is_std_substitution (decl, SUBID_BASIC_ISTREAM))
584 	    {
585 	      write_string ("Si");
586 	      return 1;
587 	    }
588 	  /* Or basic_ostream?  */
589 	  else if (is_std_substitution (decl, SUBID_BASIC_OSTREAM))
590 	    {
591 	      write_string ("So");
592 	      return 1;
593 	    }
594 	  /* Or basic_iostream?  */
595 	  else if (is_std_substitution (decl, SUBID_BASIC_IOSTREAM))
596 	    {
597 	      write_string ("Sd");
598 	      return 1;
599 	    }
600 	}
601     }
602 
603   /* Check for namespace std.  */
604   if (decl && DECL_NAMESPACE_STD_P (decl))
605     {
606       write_string ("St");
607       return 1;
608     }
609 
610   /* Now check the list of available substitutions for this mangling
611      operation.  */
612   for (i = 0; i < size; ++i)
613     {
614       tree candidate = VEC_index (tree, G.substitutions, i);
615       /* NODE is a matched to a candidate if it's the same decl node or
616 	 if it's the same type.  */
617       if (decl == candidate
618 	  || (TYPE_P (candidate) && type && TYPE_P (node)
619 	      && same_type_p (type, candidate))
620 	  || NESTED_TEMPLATE_MATCH (node, candidate))
621 	{
622 	  write_substitution (i);
623 	  return 1;
624 	}
625     }
626 
627   /* No substitution found.  */
628   return 0;
629 }
630 
631 
632 /* TOP_LEVEL is true, if this is being called at outermost level of
633   mangling. It should be false when mangling a decl appearing in an
634   expression within some other mangling.
635 
636   <mangled-name>      ::= _Z <encoding>  */
637 
638 static void
639 write_mangled_name (const tree decl, bool top_level)
640 {
641   MANGLE_TRACE_TREE ("mangled-name", decl);
642 
643   if (/* The names of `extern "C"' functions are not mangled.  */
644       DECL_EXTERN_C_FUNCTION_P (decl)
645       /* But overloaded operator names *are* mangled.  */
646       && !DECL_OVERLOADED_OPERATOR_P (decl))
647     {
648     unmangled_name:;
649 
650       if (top_level)
651 	write_string (IDENTIFIER_POINTER (DECL_NAME (decl)));
652       else
653 	{
654 	  /* The standard notes: "The <encoding> of an extern "C"
655 	     function is treated like global-scope data, i.e. as its
656 	     <source-name> without a type."  We cannot write
657 	     overloaded operators that way though, because it contains
658 	     characters invalid in assembler.  */
659 	  if (abi_version_at_least (2))
660 	    write_string ("_Z");
661 	  else
662 	    G.need_abi_warning = true;
663 	  write_source_name (DECL_NAME (decl));
664 	}
665     }
666   else if (TREE_CODE (decl) == VAR_DECL
667 	   /* The names of non-static global variables aren't mangled.  */
668 	   && DECL_EXTERNAL_LINKAGE_P (decl)
669 	   && (CP_DECL_CONTEXT (decl) == global_namespace
670 	       /* And neither are `extern "C"' variables.  */
671 	       || DECL_EXTERN_C_P (decl)))
672     {
673       if (top_level || abi_version_at_least (2))
674 	goto unmangled_name;
675       else
676 	{
677 	  G.need_abi_warning = true;
678 	  goto mangled_name;
679 	}
680     }
681   else
682     {
683     mangled_name:;
684       write_string ("_Z");
685       write_encoding (decl);
686       if (DECL_LANG_SPECIFIC (decl)
687 	  && (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (decl)
688 	      || DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (decl)))
689 	/* We need a distinct mangled name for these entities, but
690 	   we should never actually output it.  So, we append some
691 	   characters the assembler won't like.  */
692 	write_string (" *INTERNAL* ");
693     }
694 }
695 
696 /*   <encoding>		::= <function name> <bare-function-type>
697 			::= <data name>  */
698 
699 static void
700 write_encoding (const tree decl)
701 {
702   MANGLE_TRACE_TREE ("encoding", decl);
703 
704   if (DECL_LANG_SPECIFIC (decl) && DECL_EXTERN_C_FUNCTION_P (decl))
705     {
706       /* For overloaded operators write just the mangled name
707 	 without arguments.  */
708       if (DECL_OVERLOADED_OPERATOR_P (decl))
709 	write_name (decl, /*ignore_local_scope=*/0);
710       else
711 	write_source_name (DECL_NAME (decl));
712       return;
713     }
714 
715   write_name (decl, /*ignore_local_scope=*/0);
716   if (TREE_CODE (decl) == FUNCTION_DECL)
717     {
718       tree fn_type;
719       tree d;
720 
721       if (decl_is_template_id (decl, NULL))
722 	{
723 	  fn_type = get_mostly_instantiated_function_type (decl);
724 	  /* FN_TYPE will not have parameter types for in-charge or
725 	     VTT parameters.  Therefore, we pass NULL_TREE to
726 	     write_bare_function_type -- otherwise, it will get
727 	     confused about which artificial parameters to skip.  */
728 	  d = NULL_TREE;
729 	}
730       else
731 	{
732 	  fn_type = TREE_TYPE (decl);
733 	  d = decl;
734 	}
735 
736       write_bare_function_type (fn_type,
737 				(!DECL_CONSTRUCTOR_P (decl)
738 				 && !DECL_DESTRUCTOR_P (decl)
739 				 && !DECL_CONV_FN_P (decl)
740 				 && decl_is_template_id (decl, NULL)),
741 				d);
742     }
743 }
744 
745 /* Lambdas can have a bit more context for mangling, specifically VAR_DECL
746    or PARM_DECL context, which doesn't belong in DECL_CONTEXT.  */
747 
748 static tree
749 decl_mangling_context (tree decl)
750 {
751   tree tcontext = targetm.cxx.decl_mangling_context (decl);
752 
753   if (tcontext != NULL_TREE)
754     return tcontext;
755 
756   if (TREE_CODE (decl) == TYPE_DECL
757       && LAMBDA_TYPE_P (TREE_TYPE (decl)))
758     {
759       tree extra = LAMBDA_TYPE_EXTRA_SCOPE (TREE_TYPE (decl));
760       if (extra)
761 	return extra;
762     }
763     else if (TREE_CODE (decl) == TYPE_DECL
764 	     && TREE_CODE (TREE_TYPE (decl)) == TEMPLATE_TYPE_PARM)
765      /* template type parms have no mangling context.  */
766       return NULL_TREE;
767   return CP_DECL_CONTEXT (decl);
768 }
769 
770 /* <name> ::= <unscoped-name>
771 	  ::= <unscoped-template-name> <template-args>
772 	  ::= <nested-name>
773 	  ::= <local-name>
774 
775    If IGNORE_LOCAL_SCOPE is nonzero, this production of <name> is
776    called from <local-name>, which mangles the enclosing scope
777    elsewhere and then uses this function to mangle just the part
778    underneath the function scope.  So don't use the <local-name>
779    production, to avoid an infinite recursion.  */
780 
781 static void
782 write_name (tree decl, const int ignore_local_scope)
783 {
784   tree context;
785 
786   MANGLE_TRACE_TREE ("name", decl);
787 
788   if (TREE_CODE (decl) == TYPE_DECL)
789     {
790       /* In case this is a typedef, fish out the corresponding
791 	 TYPE_DECL for the main variant.  */
792       decl = TYPE_NAME (TYPE_MAIN_VARIANT (TREE_TYPE (decl)));
793     }
794 
795   context = decl_mangling_context (decl);
796 
797   /* A decl in :: or ::std scope is treated specially.  The former is
798      mangled using <unscoped-name> or <unscoped-template-name>, the
799      latter with a special substitution.  Also, a name that is
800      directly in a local function scope is also mangled with
801      <unscoped-name> rather than a full <nested-name>.  */
802   if (context == NULL
803       || context == global_namespace
804       || DECL_NAMESPACE_STD_P (context)
805       || (ignore_local_scope && TREE_CODE (context) == FUNCTION_DECL))
806     {
807       tree template_info;
808       /* Is this a template instance?  */
809       if (decl_is_template_id (decl, &template_info))
810 	{
811 	  /* Yes: use <unscoped-template-name>.  */
812 	  write_unscoped_template_name (TI_TEMPLATE (template_info));
813 	  write_template_args (TI_ARGS (template_info));
814 	}
815       else
816 	/* Everything else gets an <unqualified-name>.  */
817 	write_unscoped_name (decl);
818     }
819   else
820     {
821       /* Handle local names, unless we asked not to (that is, invoked
822 	 under <local-name>, to handle only the part of the name under
823 	 the local scope).  */
824       if (!ignore_local_scope)
825 	{
826 	  /* Scan up the list of scope context, looking for a
827 	     function.  If we find one, this entity is in local
828 	     function scope.  local_entity tracks context one scope
829 	     level down, so it will contain the element that's
830 	     directly in that function's scope, either decl or one of
831 	     its enclosing scopes.  */
832 	  tree local_entity = decl;
833 	  while (context != NULL && context != global_namespace)
834 	    {
835 	      /* Make sure we're always dealing with decls.  */
836 	      if (context != NULL && TYPE_P (context))
837 		context = TYPE_NAME (context);
838 	      /* Is this a function?  */
839 	      if (TREE_CODE (context) == FUNCTION_DECL
840 		  || TREE_CODE (context) == PARM_DECL)
841 		{
842 		  /* Yes, we have local scope.  Use the <local-name>
843 		     production for the innermost function scope.  */
844 		  write_local_name (context, local_entity, decl);
845 		  return;
846 		}
847 	      /* Up one scope level.  */
848 	      local_entity = context;
849 	      context = decl_mangling_context (context);
850 	    }
851 
852 	  /* No local scope found?  Fall through to <nested-name>.  */
853 	}
854 
855       /* Other decls get a <nested-name> to encode their scope.  */
856       write_nested_name (decl);
857     }
858 }
859 
860 /* <unscoped-name> ::= <unqualified-name>
861 		   ::= St <unqualified-name>   # ::std::  */
862 
863 static void
864 write_unscoped_name (const tree decl)
865 {
866   tree context = decl_mangling_context (decl);
867 
868   MANGLE_TRACE_TREE ("unscoped-name", decl);
869 
870   /* Is DECL in ::std?  */
871   if (DECL_NAMESPACE_STD_P (context))
872     {
873       write_string ("St");
874       write_unqualified_name (decl);
875     }
876   else
877     {
878       /* If not, it should be either in the global namespace, or directly
879 	 in a local function scope.  */
880       gcc_assert (context == global_namespace
881 		  || context != NULL
882 		  || TREE_CODE (context) == FUNCTION_DECL);
883 
884       write_unqualified_name (decl);
885     }
886 }
887 
888 /* <unscoped-template-name> ::= <unscoped-name>
889 			    ::= <substitution>  */
890 
891 static void
892 write_unscoped_template_name (const tree decl)
893 {
894   MANGLE_TRACE_TREE ("unscoped-template-name", decl);
895 
896   if (find_substitution (decl))
897     return;
898   write_unscoped_name (decl);
899   add_substitution (decl);
900 }
901 
902 /* Write the nested name, including CV-qualifiers, of DECL.
903 
904    <nested-name> ::= N [<CV-qualifiers>] <prefix> <unqualified-name> E
905 		 ::= N [<CV-qualifiers>] <template-prefix> <template-args> E
906 
907    <CV-qualifiers> ::= [r] [V] [K]  */
908 
909 static void
910 write_nested_name (const tree decl)
911 {
912   tree template_info;
913 
914   MANGLE_TRACE_TREE ("nested-name", decl);
915 
916   write_char ('N');
917 
918   /* Write CV-qualifiers, if this is a member function.  */
919   if (TREE_CODE (decl) == FUNCTION_DECL
920       && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
921     {
922       if (DECL_VOLATILE_MEMFUNC_P (decl))
923 	write_char ('V');
924       if (DECL_CONST_MEMFUNC_P (decl))
925 	write_char ('K');
926     }
927 
928   /* Is this a template instance?  */
929   if (decl_is_template_id (decl, &template_info))
930     {
931       /* Yes, use <template-prefix>.  */
932       write_template_prefix (decl);
933       write_template_args (TI_ARGS (template_info));
934     }
935   else if (TREE_CODE (TREE_TYPE (decl)) == TYPENAME_TYPE)
936     {
937       tree name = TYPENAME_TYPE_FULLNAME (TREE_TYPE (decl));
938       if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
939 	{
940 	  write_template_prefix (decl);
941 	  write_template_args (TREE_OPERAND (name, 1));
942 	}
943       else
944 	{
945 	  write_prefix (CP_DECL_CONTEXT (decl));
946 	  write_unqualified_name (decl);
947 	}
948     }
949   else
950     {
951       /* No, just use <prefix>  */
952       write_prefix (decl_mangling_context (decl));
953       write_unqualified_name (decl);
954     }
955   write_char ('E');
956 }
957 
958 /* <prefix> ::= <prefix> <unqualified-name>
959 	    ::= <template-param>
960 	    ::= <template-prefix> <template-args>
961 	    ::= <decltype>
962 	    ::= # empty
963 	    ::= <substitution>  */
964 
965 static void
966 write_prefix (const tree node)
967 {
968   tree decl;
969   /* Non-NULL if NODE represents a template-id.  */
970   tree template_info = NULL;
971 
972   if (node == NULL
973       || node == global_namespace)
974     return;
975 
976   MANGLE_TRACE_TREE ("prefix", node);
977 
978   if (TREE_CODE (node) == DECLTYPE_TYPE)
979     {
980       write_type (node);
981       return;
982     }
983 
984   if (find_substitution (node))
985     return;
986 
987   if (DECL_P (node))
988     {
989       /* If this is a function or parm decl, that means we've hit function
990 	 scope, so this prefix must be for a local name.  In this
991 	 case, we're under the <local-name> production, which encodes
992 	 the enclosing function scope elsewhere.  So don't continue
993 	 here.  */
994       if (TREE_CODE (node) == FUNCTION_DECL
995 	  || TREE_CODE (node) == PARM_DECL)
996 	return;
997 
998       decl = node;
999       decl_is_template_id (decl, &template_info);
1000     }
1001   else
1002     {
1003       /* Node is a type.  */
1004       decl = TYPE_NAME (node);
1005       if (CLASSTYPE_TEMPLATE_ID_P (node))
1006 	template_info = TYPE_TEMPLATE_INFO (node);
1007     }
1008 
1009   /* In G++ 3.2, the name of the template parameter was used.  */
1010   if (TREE_CODE (node) == TEMPLATE_TYPE_PARM
1011       && !abi_version_at_least (2))
1012     G.need_abi_warning = true;
1013 
1014   if (TREE_CODE (node) == TEMPLATE_TYPE_PARM
1015       && abi_version_at_least (2))
1016     write_template_param (node);
1017   else if (template_info != NULL)
1018     /* Templated.  */
1019     {
1020       write_template_prefix (decl);
1021       write_template_args (TI_ARGS (template_info));
1022     }
1023   else if (TREE_CODE (TREE_TYPE (decl)) == TYPENAME_TYPE)
1024     {
1025       tree name = TYPENAME_TYPE_FULLNAME (TREE_TYPE (decl));
1026       if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
1027 	{
1028 	  write_template_prefix (decl);
1029 	  write_template_args (TREE_OPERAND (name, 1));
1030 	}
1031       else
1032 	{
1033 	  write_prefix (CP_DECL_CONTEXT (decl));
1034 	  write_unqualified_name (decl);
1035 	}
1036     }
1037   else
1038     /* Not templated.  */
1039     {
1040       write_prefix (decl_mangling_context (decl));
1041       write_unqualified_name (decl);
1042       if (TREE_CODE (decl) == VAR_DECL
1043 	  || TREE_CODE (decl) == FIELD_DECL)
1044 	{
1045 	  /* <data-member-prefix> := <member source-name> M */
1046 	  write_char ('M');
1047 	  return;
1048 	}
1049     }
1050 
1051   add_substitution (node);
1052 }
1053 
1054 /* <template-prefix> ::= <prefix> <template component>
1055 		     ::= <template-param>
1056 		     ::= <substitution>  */
1057 
1058 static void
1059 write_template_prefix (const tree node)
1060 {
1061   tree decl = DECL_P (node) ? node : TYPE_NAME (node);
1062   tree type = DECL_P (node) ? TREE_TYPE (node) : node;
1063   tree context = CP_DECL_CONTEXT (decl);
1064   tree template_info;
1065   tree templ;
1066   tree substitution;
1067 
1068   MANGLE_TRACE_TREE ("template-prefix", node);
1069 
1070   /* Find the template decl.  */
1071   if (decl_is_template_id (decl, &template_info))
1072     templ = TI_TEMPLATE (template_info);
1073   else if (TREE_CODE (type) == TYPENAME_TYPE)
1074     /* For a typename type, all we have is the name.  */
1075     templ = DECL_NAME (decl);
1076   else
1077     {
1078       gcc_assert (CLASSTYPE_TEMPLATE_ID_P (type));
1079 
1080       templ = TYPE_TI_TEMPLATE (type);
1081     }
1082 
1083   /* For a member template, though, the template name for the
1084      innermost name must have all the outer template levels
1085      instantiated.  For instance, consider
1086 
1087        template<typename T> struct Outer {
1088 	 template<typename U> struct Inner {};
1089        };
1090 
1091      The template name for `Inner' in `Outer<int>::Inner<float>' is
1092      `Outer<int>::Inner<U>'.  In g++, we don't instantiate the template
1093      levels separately, so there's no TEMPLATE_DECL available for this
1094      (there's only `Outer<T>::Inner<U>').
1095 
1096      In order to get the substitutions right, we create a special
1097      TREE_LIST to represent the substitution candidate for a nested
1098      template.  The TREE_PURPOSE is the template's context, fully
1099      instantiated, and the TREE_VALUE is the TEMPLATE_DECL for the inner
1100      template.
1101 
1102      So, for the example above, `Outer<int>::Inner' is represented as a
1103      substitution candidate by a TREE_LIST whose purpose is `Outer<int>'
1104      and whose value is `Outer<T>::Inner<U>'.  */
1105   if (TYPE_P (context))
1106     substitution = build_tree_list (context, templ);
1107   else
1108     substitution = templ;
1109 
1110   if (find_substitution (substitution))
1111     return;
1112 
1113   /* In G++ 3.2, the name of the template template parameter was used.  */
1114   if (TREE_TYPE (templ)
1115       && TREE_CODE (TREE_TYPE (templ)) == TEMPLATE_TEMPLATE_PARM
1116       && !abi_version_at_least (2))
1117     G.need_abi_warning = true;
1118 
1119   if (TREE_TYPE (templ)
1120       && TREE_CODE (TREE_TYPE (templ)) == TEMPLATE_TEMPLATE_PARM
1121       && abi_version_at_least (2))
1122     write_template_param (TREE_TYPE (templ));
1123   else
1124     {
1125       write_prefix (context);
1126       write_unqualified_name (decl);
1127     }
1128 
1129   add_substitution (substitution);
1130 }
1131 
1132 /* We don't need to handle thunks, vtables, or VTTs here.  Those are
1133    mangled through special entry points.
1134 
1135     <unqualified-name>  ::= <operator-name>
1136 			::= <special-name>
1137 			::= <source-name>
1138 			::= <unnamed-type-name>
1139 			::= <local-source-name>
1140 
1141     <local-source-name>	::= L <source-name> <discriminator> */
1142 
1143 static void
1144 write_unqualified_id (tree identifier)
1145 {
1146   if (IDENTIFIER_TYPENAME_P (identifier))
1147     write_conversion_operator_name (TREE_TYPE (identifier));
1148   else if (IDENTIFIER_OPNAME_P (identifier))
1149     {
1150       int i;
1151       const char *mangled_name = NULL;
1152 
1153       /* Unfortunately, there is no easy way to go from the
1154 	 name of the operator back to the corresponding tree
1155 	 code.  */
1156       for (i = 0; i < MAX_TREE_CODES; ++i)
1157 	if (operator_name_info[i].identifier == identifier)
1158 	  {
1159 	    /* The ABI says that we prefer binary operator
1160 	       names to unary operator names.  */
1161 	    if (operator_name_info[i].arity == 2)
1162 	      {
1163 		mangled_name = operator_name_info[i].mangled_name;
1164 		break;
1165 	      }
1166 	    else if (!mangled_name)
1167 	      mangled_name = operator_name_info[i].mangled_name;
1168 	  }
1169 	else if (assignment_operator_name_info[i].identifier
1170 		 == identifier)
1171 	  {
1172 	    mangled_name
1173 	      = assignment_operator_name_info[i].mangled_name;
1174 	    break;
1175 	  }
1176       write_string (mangled_name);
1177     }
1178   else if (UDLIT_OPER_P (identifier))
1179     write_literal_operator_name (identifier);
1180   else
1181     write_source_name (identifier);
1182 }
1183 
1184 static void
1185 write_unqualified_name (const tree decl)
1186 {
1187   MANGLE_TRACE_TREE ("unqualified-name", decl);
1188 
1189   if (TREE_CODE (decl) == IDENTIFIER_NODE)
1190     {
1191       write_unqualified_id (decl);
1192       return;
1193     }
1194 
1195   if (DECL_NAME (decl) == NULL_TREE)
1196     {
1197       gcc_assert (DECL_ASSEMBLER_NAME_SET_P (decl));
1198       write_source_name (DECL_ASSEMBLER_NAME (decl));
1199       return;
1200     }
1201   else if (DECL_DECLARES_FUNCTION_P (decl))
1202     {
1203       bool found = true;
1204       if (DECL_CONSTRUCTOR_P (decl))
1205 	write_special_name_constructor (decl);
1206       else if (DECL_DESTRUCTOR_P (decl))
1207 	write_special_name_destructor (decl);
1208       else if (DECL_CONV_FN_P (decl))
1209 	{
1210 	  /* Conversion operator. Handle it right here.
1211 	     <operator> ::= cv <type>  */
1212 	  tree type;
1213 	  if (decl_is_template_id (decl, NULL))
1214 	    {
1215 	      tree fn_type;
1216 	      fn_type = get_mostly_instantiated_function_type (decl);
1217 	      type = TREE_TYPE (fn_type);
1218 	    }
1219 	  else
1220 	    type = DECL_CONV_FN_TYPE (decl);
1221 	  write_conversion_operator_name (type);
1222 	}
1223       else if (DECL_OVERLOADED_OPERATOR_P (decl))
1224 	{
1225 	  operator_name_info_t *oni;
1226 	  if (DECL_ASSIGNMENT_OPERATOR_P (decl))
1227 	    oni = assignment_operator_name_info;
1228 	  else
1229 	    oni = operator_name_info;
1230 
1231 	  write_string (oni[DECL_OVERLOADED_OPERATOR_P (decl)].mangled_name);
1232 	}
1233       else if (UDLIT_OPER_P (DECL_NAME (decl)))
1234 	write_literal_operator_name (DECL_NAME (decl));
1235       else
1236 	found = false;
1237 
1238       if (found)
1239 	return;
1240     }
1241 
1242   if (VAR_OR_FUNCTION_DECL_P (decl) && ! TREE_PUBLIC (decl)
1243       && DECL_NAMESPACE_SCOPE_P (decl)
1244       && decl_linkage (decl) == lk_internal)
1245     {
1246       MANGLE_TRACE_TREE ("local-source-name", decl);
1247       write_char ('L');
1248       write_source_name (DECL_NAME (decl));
1249       /* The default discriminator is 1, and that's all we ever use,
1250 	 so there's no code to output one here.  */
1251     }
1252   else
1253     {
1254       tree type = TREE_TYPE (decl);
1255 
1256       if (TREE_CODE (decl) == TYPE_DECL
1257           && TYPE_ANONYMOUS_P (type))
1258         write_unnamed_type_name (type);
1259       else if (TREE_CODE (decl) == TYPE_DECL
1260                && LAMBDA_TYPE_P (type))
1261         write_closure_type_name (type);
1262       else
1263         write_source_name (DECL_NAME (decl));
1264     }
1265 }
1266 
1267 /* Write the unqualified-name for a conversion operator to TYPE.  */
1268 
1269 static void
1270 write_conversion_operator_name (const tree type)
1271 {
1272   write_string ("cv");
1273   write_type (type);
1274 }
1275 
1276 /* Non-terminal <source-name>.  IDENTIFIER is an IDENTIFIER_NODE.
1277 
1278      <source-name> ::= </length/ number> <identifier>  */
1279 
1280 static void
1281 write_source_name (tree identifier)
1282 {
1283   MANGLE_TRACE_TREE ("source-name", identifier);
1284 
1285   /* Never write the whole template-id name including the template
1286      arguments; we only want the template name.  */
1287   if (IDENTIFIER_TEMPLATE (identifier))
1288     identifier = IDENTIFIER_TEMPLATE (identifier);
1289 
1290   write_unsigned_number (IDENTIFIER_LENGTH (identifier));
1291   write_identifier (IDENTIFIER_POINTER (identifier));
1292 }
1293 
1294 /* Write a user-defined literal operator.
1295           ::= li <source-name>    # "" <source-name>
1296    IDENTIFIER is an LITERAL_IDENTIFIER_NODE.  */
1297 
1298 static void
1299 write_literal_operator_name (tree identifier)
1300 {
1301   const char* suffix = UDLIT_OP_SUFFIX (identifier);
1302   write_identifier (UDLIT_OP_MANGLED_PREFIX);
1303   write_unsigned_number (strlen (suffix));
1304   write_identifier (suffix);
1305 }
1306 
1307 /* Encode 0 as _, and 1+ as n-1_.  */
1308 
1309 static void
1310 write_compact_number (int num)
1311 {
1312   if (num > 0)
1313     write_unsigned_number (num - 1);
1314   write_char ('_');
1315 }
1316 
1317 /* Return how many unnamed types precede TYPE in its enclosing class.  */
1318 
1319 static int
1320 nested_anon_class_index (tree type)
1321 {
1322   int index = 0;
1323   tree member = TYPE_FIELDS (TYPE_CONTEXT (type));
1324   for (; member; member = DECL_CHAIN (member))
1325     if (DECL_IMPLICIT_TYPEDEF_P (member))
1326       {
1327 	tree memtype = TREE_TYPE (member);
1328 	if (memtype == type)
1329 	  return index;
1330 	else if (TYPE_ANONYMOUS_P (memtype))
1331 	  ++index;
1332       }
1333 
1334   gcc_unreachable ();
1335 }
1336 
1337 /* <unnamed-type-name> ::= Ut [ <nonnegative number> ] _ */
1338 
1339 static void
1340 write_unnamed_type_name (const tree type ATTRIBUTE_UNUSED)
1341 {
1342   int discriminator;
1343   MANGLE_TRACE_TREE ("unnamed-type-name", type);
1344 
1345   if (TYPE_FUNCTION_SCOPE_P (type))
1346     discriminator = local_class_index (type);
1347   else if (TYPE_CLASS_SCOPE_P (type))
1348     discriminator = nested_anon_class_index (type);
1349   else
1350     {
1351       gcc_assert (no_linkage_check (type, /*relaxed_p=*/true));
1352       /* Just use the old mangling at namespace scope.  */
1353       write_source_name (TYPE_IDENTIFIER (type));
1354       return;
1355     }
1356 
1357   write_string ("Ut");
1358   write_compact_number (discriminator);
1359 }
1360 
1361 /* <closure-type-name> ::= Ul <lambda-sig> E [ <nonnegative number> ] _
1362    <lambda-sig> ::= <parameter type>+  # Parameter types or "v" if the lambda has no parameters */
1363 
1364 static void
1365 write_closure_type_name (const tree type)
1366 {
1367   tree fn = lambda_function (type);
1368   tree lambda = CLASSTYPE_LAMBDA_EXPR (type);
1369   tree parms = TYPE_ARG_TYPES (TREE_TYPE (fn));
1370 
1371   MANGLE_TRACE_TREE ("closure-type-name", type);
1372 
1373   write_string ("Ul");
1374   write_method_parms (parms, /*method_p=*/1, fn);
1375   write_char ('E');
1376   write_compact_number (LAMBDA_EXPR_DISCRIMINATOR (lambda));
1377 }
1378 
1379 /* Convert NUMBER to ascii using base BASE and generating at least
1380    MIN_DIGITS characters. BUFFER points to the _end_ of the buffer
1381    into which to store the characters. Returns the number of
1382    characters generated (these will be layed out in advance of where
1383    BUFFER points).  */
1384 
1385 static int
1386 hwint_to_ascii (unsigned HOST_WIDE_INT number, const unsigned int base,
1387 		char *buffer, const unsigned int min_digits)
1388 {
1389   static const char base_digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
1390   unsigned digits = 0;
1391 
1392   while (number)
1393     {
1394       unsigned HOST_WIDE_INT d = number / base;
1395 
1396       *--buffer = base_digits[number - d * base];
1397       digits++;
1398       number = d;
1399     }
1400   while (digits < min_digits)
1401     {
1402       *--buffer = base_digits[0];
1403       digits++;
1404     }
1405   return digits;
1406 }
1407 
1408 /* Non-terminal <number>.
1409 
1410      <number> ::= [n] </decimal integer/>  */
1411 
1412 static void
1413 write_number (unsigned HOST_WIDE_INT number, const int unsigned_p,
1414 	      const unsigned int base)
1415 {
1416   char buffer[sizeof (HOST_WIDE_INT) * 8];
1417   unsigned count = 0;
1418 
1419   if (!unsigned_p && (HOST_WIDE_INT) number < 0)
1420     {
1421       write_char ('n');
1422       number = -((HOST_WIDE_INT) number);
1423     }
1424   count = hwint_to_ascii (number, base, buffer + sizeof (buffer), 1);
1425   write_chars (buffer + sizeof (buffer) - count, count);
1426 }
1427 
1428 /* Write out an integral CST in decimal. Most numbers are small, and
1429    representable in a HOST_WIDE_INT. Occasionally we'll have numbers
1430    bigger than that, which we must deal with.  */
1431 
1432 static inline void
1433 write_integer_cst (const tree cst)
1434 {
1435   int sign = tree_int_cst_sgn (cst);
1436 
1437   if (TREE_INT_CST_HIGH (cst) + (sign < 0))
1438     {
1439       /* A bignum. We do this in chunks, each of which fits in a
1440 	 HOST_WIDE_INT.  */
1441       char buffer[sizeof (HOST_WIDE_INT) * 8 * 2];
1442       unsigned HOST_WIDE_INT chunk;
1443       unsigned chunk_digits;
1444       char *ptr = buffer + sizeof (buffer);
1445       unsigned count = 0;
1446       tree n, base, type;
1447       int done;
1448 
1449       /* HOST_WIDE_INT must be at least 32 bits, so 10^9 is
1450 	 representable.  */
1451       chunk = 1000000000;
1452       chunk_digits = 9;
1453 
1454       if (sizeof (HOST_WIDE_INT) >= 8)
1455 	{
1456 	  /* It is at least 64 bits, so 10^18 is representable.  */
1457 	  chunk_digits = 18;
1458 	  chunk *= chunk;
1459 	}
1460 
1461       type = c_common_signed_or_unsigned_type (1, TREE_TYPE (cst));
1462       base = build_int_cstu (type, chunk);
1463       n = build_int_cst_wide (type,
1464 			      TREE_INT_CST_LOW (cst), TREE_INT_CST_HIGH (cst));
1465 
1466       if (sign < 0)
1467 	{
1468 	  write_char ('n');
1469 	  n = fold_build1_loc (input_location, NEGATE_EXPR, type, n);
1470 	}
1471       do
1472 	{
1473 	  tree d = fold_build2_loc (input_location, FLOOR_DIV_EXPR, type, n, base);
1474 	  tree tmp = fold_build2_loc (input_location, MULT_EXPR, type, d, base);
1475 	  unsigned c;
1476 
1477 	  done = integer_zerop (d);
1478 	  tmp = fold_build2_loc (input_location, MINUS_EXPR, type, n, tmp);
1479 	  c = hwint_to_ascii (TREE_INT_CST_LOW (tmp), 10, ptr,
1480 			      done ? 1 : chunk_digits);
1481 	  ptr -= c;
1482 	  count += c;
1483 	  n = d;
1484 	}
1485       while (!done);
1486       write_chars (ptr, count);
1487     }
1488   else
1489     {
1490       /* A small num.  */
1491       unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (cst);
1492 
1493       if (sign < 0)
1494 	{
1495 	  write_char ('n');
1496 	  low = -low;
1497 	}
1498       write_unsigned_number (low);
1499     }
1500 }
1501 
1502 /* Write out a floating-point literal.
1503 
1504     "Floating-point literals are encoded using the bit pattern of the
1505     target processor's internal representation of that number, as a
1506     fixed-length lowercase hexadecimal string, high-order bytes first
1507     (even if the target processor would store low-order bytes first).
1508     The "n" prefix is not used for floating-point literals; the sign
1509     bit is encoded with the rest of the number.
1510 
1511     Here are some examples, assuming the IEEE standard representation
1512     for floating point numbers.  (Spaces are for readability, not
1513     part of the encoding.)
1514 
1515 	1.0f			Lf 3f80 0000 E
1516        -1.0f			Lf bf80 0000 E
1517 	1.17549435e-38f		Lf 0080 0000 E
1518 	1.40129846e-45f		Lf 0000 0001 E
1519 	0.0f			Lf 0000 0000 E"
1520 
1521    Caller is responsible for the Lx and the E.  */
1522 static void
1523 write_real_cst (const tree value)
1524 {
1525   if (abi_version_at_least (2))
1526     {
1527       long target_real[4];  /* largest supported float */
1528       char buffer[9];       /* eight hex digits in a 32-bit number */
1529       int i, limit, dir;
1530 
1531       tree type = TREE_TYPE (value);
1532       int words = GET_MODE_BITSIZE (TYPE_MODE (type)) / 32;
1533 
1534       real_to_target (target_real, &TREE_REAL_CST (value),
1535 		      TYPE_MODE (type));
1536 
1537       /* The value in target_real is in the target word order,
1538 	 so we must write it out backward if that happens to be
1539 	 little-endian.  write_number cannot be used, it will
1540 	 produce uppercase.  */
1541       if (FLOAT_WORDS_BIG_ENDIAN)
1542 	i = 0, limit = words, dir = 1;
1543       else
1544 	i = words - 1, limit = -1, dir = -1;
1545 
1546       for (; i != limit; i += dir)
1547 	{
1548 	  sprintf (buffer, "%08lx", (unsigned long) target_real[i]);
1549 	  write_chars (buffer, 8);
1550 	}
1551     }
1552   else
1553     {
1554       /* In G++ 3.3 and before the REAL_VALUE_TYPE was written out
1555 	 literally.  Note that compatibility with 3.2 is impossible,
1556 	 because the old floating-point emulator used a different
1557 	 format for REAL_VALUE_TYPE.  */
1558       size_t i;
1559       for (i = 0; i < sizeof (TREE_REAL_CST (value)); ++i)
1560 	write_number (((unsigned char *) &TREE_REAL_CST (value))[i],
1561 		      /*unsigned_p*/ 1,
1562 		      /*base*/ 16);
1563       G.need_abi_warning = 1;
1564     }
1565 }
1566 
1567 /* Non-terminal <identifier>.
1568 
1569      <identifier> ::= </unqualified source code identifier>  */
1570 
1571 static void
1572 write_identifier (const char *identifier)
1573 {
1574   MANGLE_TRACE ("identifier", identifier);
1575   write_string (identifier);
1576 }
1577 
1578 /* Handle constructor productions of non-terminal <special-name>.
1579    CTOR is a constructor FUNCTION_DECL.
1580 
1581      <special-name> ::= C1   # complete object constructor
1582 		    ::= C2   # base object constructor
1583 		    ::= C3   # complete object allocating constructor
1584 
1585    Currently, allocating constructors are never used.
1586 
1587    We also need to provide mangled names for the maybe-in-charge
1588    constructor, so we treat it here too.  mangle_decl_string will
1589    append *INTERNAL* to that, to make sure we never emit it.  */
1590 
1591 static void
1592 write_special_name_constructor (const tree ctor)
1593 {
1594   if (DECL_BASE_CONSTRUCTOR_P (ctor))
1595     write_string ("C2");
1596   else
1597     {
1598       gcc_assert (DECL_COMPLETE_CONSTRUCTOR_P (ctor)
1599 		  /* Even though we don't ever emit a definition of
1600 		     the old-style destructor, we still have to
1601 		     consider entities (like static variables) nested
1602 		     inside it.  */
1603 		  || DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (ctor));
1604       write_string ("C1");
1605     }
1606 }
1607 
1608 /* Handle destructor productions of non-terminal <special-name>.
1609    DTOR is a destructor FUNCTION_DECL.
1610 
1611      <special-name> ::= D0 # deleting (in-charge) destructor
1612 		    ::= D1 # complete object (in-charge) destructor
1613 		    ::= D2 # base object (not-in-charge) destructor
1614 
1615    We also need to provide mangled names for the maybe-incharge
1616    destructor, so we treat it here too.  mangle_decl_string will
1617    append *INTERNAL* to that, to make sure we never emit it.  */
1618 
1619 static void
1620 write_special_name_destructor (const tree dtor)
1621 {
1622   if (DECL_DELETING_DESTRUCTOR_P (dtor))
1623     write_string ("D0");
1624   else if (DECL_BASE_DESTRUCTOR_P (dtor))
1625     write_string ("D2");
1626   else
1627     {
1628       gcc_assert (DECL_COMPLETE_DESTRUCTOR_P (dtor)
1629 		  /* Even though we don't ever emit a definition of
1630 		     the old-style destructor, we still have to
1631 		     consider entities (like static variables) nested
1632 		     inside it.  */
1633 		  || DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (dtor));
1634       write_string ("D1");
1635     }
1636 }
1637 
1638 /* Scan the vector of local classes and return how many others with the
1639    same name (or same no name) and context precede ENTITY.  */
1640 
1641 static int
1642 local_class_index (tree entity)
1643 {
1644   int ix, discriminator = 0;
1645   tree name = (TYPE_ANONYMOUS_P (entity) ? NULL_TREE
1646 	       : TYPE_IDENTIFIER (entity));
1647   tree ctx = TYPE_CONTEXT (entity);
1648   for (ix = 0; ; ix++)
1649     {
1650       tree type = VEC_index (tree, local_classes, ix);
1651       if (type == entity)
1652 	return discriminator;
1653       if (TYPE_CONTEXT (type) == ctx
1654 	  && (name ? TYPE_IDENTIFIER (type) == name
1655 	      : TYPE_ANONYMOUS_P (type)))
1656 	++discriminator;
1657     }
1658   gcc_unreachable ();
1659 }
1660 
1661 /* Return the discriminator for ENTITY appearing inside
1662    FUNCTION.  The discriminator is the lexical ordinal of VAR among
1663    entities with the same name in the same FUNCTION.  */
1664 
1665 static int
1666 discriminator_for_local_entity (tree entity)
1667 {
1668   if (DECL_DISCRIMINATOR_P (entity))
1669     {
1670       if (DECL_DISCRIMINATOR_SET_P (entity))
1671 	return DECL_DISCRIMINATOR (entity);
1672       else
1673 	/* The first entity with a particular name doesn't get
1674 	   DECL_DISCRIMINATOR set up.  */
1675 	return 0;
1676     }
1677   else if (TREE_CODE (entity) == TYPE_DECL)
1678     {
1679       /* Scan the list of local classes.  */
1680       entity = TREE_TYPE (entity);
1681 
1682       /* Lambdas and unnamed types have their own discriminators.  */
1683       if (LAMBDA_TYPE_P (entity) || TYPE_ANONYMOUS_P (entity))
1684 	return 0;
1685 
1686       return local_class_index (entity);
1687     }
1688   else
1689     gcc_unreachable ();
1690 }
1691 
1692 /* Return the discriminator for STRING, a string literal used inside
1693    FUNCTION.  The discriminator is the lexical ordinal of STRING among
1694    string literals used in FUNCTION.  */
1695 
1696 static int
1697 discriminator_for_string_literal (tree function ATTRIBUTE_UNUSED,
1698 				  tree string ATTRIBUTE_UNUSED)
1699 {
1700   /* For now, we don't discriminate amongst string literals.  */
1701   return 0;
1702 }
1703 
1704 /*   <discriminator> := _ <number>
1705 
1706    The discriminator is used only for the second and later occurrences
1707    of the same name within a single function. In this case <number> is
1708    n - 2, if this is the nth occurrence, in lexical order.  */
1709 
1710 static void
1711 write_discriminator (const int discriminator)
1712 {
1713   /* If discriminator is zero, don't write anything.  Otherwise...  */
1714   if (discriminator > 0)
1715     {
1716       write_char ('_');
1717       write_unsigned_number (discriminator - 1);
1718     }
1719 }
1720 
1721 /* Mangle the name of a function-scope entity.  FUNCTION is the
1722    FUNCTION_DECL for the enclosing function, or a PARM_DECL for lambdas in
1723    default argument scope.  ENTITY is the decl for the entity itself.
1724    LOCAL_ENTITY is the entity that's directly scoped in FUNCTION_DECL,
1725    either ENTITY itself or an enclosing scope of ENTITY.
1726 
1727      <local-name> := Z <function encoding> E <entity name> [<discriminator>]
1728 		  := Z <function encoding> E s [<discriminator>]
1729 		  := Z <function encoding> Ed [ <parameter number> ] _ <entity name> */
1730 
1731 static void
1732 write_local_name (tree function, const tree local_entity,
1733 		  const tree entity)
1734 {
1735   tree parm = NULL_TREE;
1736 
1737   MANGLE_TRACE_TREE ("local-name", entity);
1738 
1739   if (TREE_CODE (function) == PARM_DECL)
1740     {
1741       parm = function;
1742       function = DECL_CONTEXT (parm);
1743     }
1744 
1745   write_char ('Z');
1746   write_encoding (function);
1747   write_char ('E');
1748 
1749   /* For this purpose, parameters are numbered from right-to-left.  */
1750   if (parm)
1751     {
1752       tree t;
1753       int i = 0;
1754       for (t = DECL_ARGUMENTS (function); t; t = DECL_CHAIN (t))
1755 	{
1756 	  if (t == parm)
1757 	    i = 1;
1758 	  else if (i)
1759 	    ++i;
1760 	}
1761       write_char ('d');
1762       write_compact_number (i - 1);
1763     }
1764 
1765   if (TREE_CODE (entity) == STRING_CST)
1766     {
1767       write_char ('s');
1768       write_discriminator (discriminator_for_string_literal (function,
1769 							     entity));
1770     }
1771   else
1772     {
1773       /* Now the <entity name>.  Let write_name know its being called
1774 	 from <local-name>, so it doesn't try to process the enclosing
1775 	 function scope again.  */
1776       write_name (entity, /*ignore_local_scope=*/1);
1777       write_discriminator (discriminator_for_local_entity (local_entity));
1778     }
1779 }
1780 
1781 /* Non-terminals <type> and <CV-qualifier>.
1782 
1783      <type> ::= <builtin-type>
1784 	    ::= <function-type>
1785 	    ::= <class-enum-type>
1786 	    ::= <array-type>
1787 	    ::= <pointer-to-member-type>
1788 	    ::= <template-param>
1789 	    ::= <substitution>
1790 	    ::= <CV-qualifier>
1791 	    ::= P <type>    # pointer-to
1792 	    ::= R <type>    # reference-to
1793 	    ::= C <type>    # complex pair (C 2000)
1794 	    ::= G <type>    # imaginary (C 2000)     [not supported]
1795 	    ::= U <source-name> <type>   # vendor extended type qualifier
1796 
1797    C++0x extensions
1798 
1799      <type> ::= RR <type>   # rvalue reference-to
1800      <type> ::= Dt <expression> # decltype of an id-expression or
1801                                 # class member access
1802      <type> ::= DT <expression> # decltype of an expression
1803      <type> ::= Dn              # decltype of nullptr
1804 
1805    TYPE is a type node.  */
1806 
1807 static void
1808 write_type (tree type)
1809 {
1810   /* This gets set to nonzero if TYPE turns out to be a (possibly
1811      CV-qualified) builtin type.  */
1812   int is_builtin_type = 0;
1813 
1814   MANGLE_TRACE_TREE ("type", type);
1815 
1816   if (type == error_mark_node)
1817     return;
1818 
1819   type = canonicalize_for_substitution (type);
1820   if (find_substitution (type))
1821     return;
1822 
1823 
1824   if (write_CV_qualifiers_for_type (type) > 0)
1825     /* If TYPE was CV-qualified, we just wrote the qualifiers; now
1826        mangle the unqualified type.  The recursive call is needed here
1827        since both the qualified and unqualified types are substitution
1828        candidates.  */
1829     write_type (TYPE_MAIN_VARIANT (type));
1830   else if (TREE_CODE (type) == ARRAY_TYPE)
1831     /* It is important not to use the TYPE_MAIN_VARIANT of TYPE here
1832        so that the cv-qualification of the element type is available
1833        in write_array_type.  */
1834     write_array_type (type);
1835   else
1836     {
1837       tree type_orig = type;
1838 
1839       /* See through any typedefs.  */
1840       type = TYPE_MAIN_VARIANT (type);
1841 
1842       /* According to the C++ ABI, some library classes are passed the
1843 	 same as the scalar type of their single member and use the same
1844 	 mangling.  */
1845       if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
1846 	type = TREE_TYPE (first_field (type));
1847 
1848       if (TYPE_PTRMEM_P (type))
1849 	write_pointer_to_member_type (type);
1850       else
1851         {
1852 	  /* Handle any target-specific fundamental types.  */
1853 	  const char *target_mangling
1854 	    = targetm.mangle_type (type_orig);
1855 
1856 	  if (target_mangling)
1857 	    {
1858 	      write_string (target_mangling);
1859 	      /* Add substitutions for types other than fundamental
1860 		 types.  */
1861 	      if (TREE_CODE (type) != VOID_TYPE
1862 		  && TREE_CODE (type) != INTEGER_TYPE
1863 		  && TREE_CODE (type) != REAL_TYPE
1864 		  && TREE_CODE (type) != BOOLEAN_TYPE)
1865 		add_substitution (type);
1866 	      return;
1867 	    }
1868 
1869 	  switch (TREE_CODE (type))
1870 	    {
1871 	    case VOID_TYPE:
1872 	    case BOOLEAN_TYPE:
1873 	    case INTEGER_TYPE:  /* Includes wchar_t.  */
1874 	    case REAL_TYPE:
1875 	    case FIXED_POINT_TYPE:
1876 	      {
1877 		/* If this is a typedef, TYPE may not be one of
1878 		   the standard builtin type nodes, but an alias of one.  Use
1879 		   TYPE_MAIN_VARIANT to get to the underlying builtin type.  */
1880 		write_builtin_type (TYPE_MAIN_VARIANT (type));
1881 		++is_builtin_type;
1882 	      }
1883 	      break;
1884 
1885 	    case COMPLEX_TYPE:
1886 	      write_char ('C');
1887 	      write_type (TREE_TYPE (type));
1888 	      break;
1889 
1890 	    case FUNCTION_TYPE:
1891 	    case METHOD_TYPE:
1892 	      write_function_type (type);
1893 	      break;
1894 
1895 	    case UNION_TYPE:
1896 	    case RECORD_TYPE:
1897 	    case ENUMERAL_TYPE:
1898 	      /* A pointer-to-member function is represented as a special
1899 		 RECORD_TYPE, so check for this first.  */
1900 	      if (TYPE_PTRMEMFUNC_P (type))
1901 		write_pointer_to_member_type (type);
1902 	      else
1903 		write_class_enum_type (type);
1904 	      break;
1905 
1906 	    case TYPENAME_TYPE:
1907 	    case UNBOUND_CLASS_TEMPLATE:
1908 	      /* We handle TYPENAME_TYPEs and UNBOUND_CLASS_TEMPLATEs like
1909 		 ordinary nested names.  */
1910 	      write_nested_name (TYPE_STUB_DECL (type));
1911 	      break;
1912 
1913 	    case POINTER_TYPE:
1914 	    case REFERENCE_TYPE:
1915 	      if (TREE_CODE (type) == POINTER_TYPE)
1916 		write_char ('P');
1917 	      else if (TYPE_REF_IS_RVALUE (type))
1918 		write_char ('O');
1919               else
1920                 write_char ('R');
1921 	      {
1922 		tree target = TREE_TYPE (type);
1923 		/* Attribute const/noreturn are not reflected in mangling.
1924 		   We strip them here rather than at a lower level because
1925 		   a typedef or template argument can have function type
1926 		   with function-cv-quals (that use the same representation),
1927 		   but you can't have a pointer/reference to such a type.  */
1928 		if (abi_version_at_least (5)
1929 		    && TREE_CODE (target) == FUNCTION_TYPE)
1930 		  target = build_qualified_type (target, TYPE_UNQUALIFIED);
1931 		write_type (target);
1932 	      }
1933 	      break;
1934 
1935 	    case TEMPLATE_TYPE_PARM:
1936 	      if (is_auto (type))
1937 		{
1938 		  write_identifier ("Da");
1939 		  ++is_builtin_type;
1940 		  break;
1941 		}
1942 	      /* else fall through.  */
1943 	    case TEMPLATE_PARM_INDEX:
1944 	      write_template_param (type);
1945 	      break;
1946 
1947 	    case TEMPLATE_TEMPLATE_PARM:
1948 	      write_template_template_param (type);
1949 	      break;
1950 
1951 	    case BOUND_TEMPLATE_TEMPLATE_PARM:
1952 	      write_template_template_param (type);
1953 	      write_template_args
1954 		(TI_ARGS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (type)));
1955 	      break;
1956 
1957 	    case VECTOR_TYPE:
1958 	      if (abi_version_at_least (4))
1959 		{
1960 		  write_string ("Dv");
1961 		  /* Non-constant vector size would be encoded with
1962 		     _ expression, but we don't support that yet.  */
1963 		  write_unsigned_number (TYPE_VECTOR_SUBPARTS (type));
1964 		  write_char ('_');
1965 		}
1966 	      else
1967 		{
1968 		  G.need_abi_warning = 1;
1969 		  write_string ("U8__vector");
1970 		}
1971 	      write_type (TREE_TYPE (type));
1972 	      break;
1973 
1974             case TYPE_PACK_EXPANSION:
1975               write_string ("Dp");
1976               write_type (PACK_EXPANSION_PATTERN (type));
1977               break;
1978 
1979             case DECLTYPE_TYPE:
1980 	      /* These shouldn't make it into mangling.  */
1981 	      gcc_assert (!DECLTYPE_FOR_LAMBDA_CAPTURE (type)
1982 			  && !DECLTYPE_FOR_LAMBDA_PROXY (type));
1983 
1984 	      /* In ABI <5, we stripped decltype of a plain decl.  */
1985 	      if (!abi_version_at_least (5)
1986 		  && DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (type))
1987 		{
1988 		  tree expr = DECLTYPE_TYPE_EXPR (type);
1989 		  tree etype = NULL_TREE;
1990 		  switch (TREE_CODE (expr))
1991 		    {
1992 		    case VAR_DECL:
1993 		    case PARM_DECL:
1994 		    case RESULT_DECL:
1995 		    case FUNCTION_DECL:
1996 		    case CONST_DECL:
1997 		    case TEMPLATE_PARM_INDEX:
1998 		      etype = TREE_TYPE (expr);
1999 		      break;
2000 
2001 		    default:
2002 		      break;
2003 		    }
2004 
2005 		  if (etype && !type_uses_auto (etype))
2006 		    {
2007 		      G.need_abi_warning = 1;
2008 		      write_type (etype);
2009 		      return;
2010 		    }
2011 		}
2012 
2013               write_char ('D');
2014               if (DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (type))
2015                 write_char ('t');
2016               else
2017                 write_char ('T');
2018 	      ++cp_unevaluated_operand;
2019               write_expression (DECLTYPE_TYPE_EXPR (type));
2020 	      --cp_unevaluated_operand;
2021               write_char ('E');
2022               break;
2023 
2024 	    case NULLPTR_TYPE:
2025 	      write_string ("Dn");
2026 	      break;
2027 
2028 	    case TYPEOF_TYPE:
2029 	      sorry ("mangling typeof, use decltype instead");
2030 	      break;
2031 
2032 	    case UNDERLYING_TYPE:
2033 	      sorry ("mangling __underlying_type");
2034 	      break;
2035 
2036 	    case LANG_TYPE:
2037 	      /* fall through.  */
2038 
2039 	    default:
2040 	      gcc_unreachable ();
2041 	    }
2042 	}
2043     }
2044 
2045   /* Types other than builtin types are substitution candidates.  */
2046   if (!is_builtin_type)
2047     add_substitution (type);
2048 }
2049 
2050 /* Non-terminal <CV-qualifiers> for type nodes.  Returns the number of
2051    CV-qualifiers written for TYPE.
2052 
2053      <CV-qualifiers> ::= [r] [V] [K]  */
2054 
2055 static int
2056 write_CV_qualifiers_for_type (const tree type)
2057 {
2058   int num_qualifiers = 0;
2059 
2060   /* The order is specified by:
2061 
2062        "In cases where multiple order-insensitive qualifiers are
2063        present, they should be ordered 'K' (closest to the base type),
2064        'V', 'r', and 'U' (farthest from the base type) ..."
2065 
2066      Note that we do not use cp_type_quals below; given "const
2067      int[3]", the "const" is emitted with the "int", not with the
2068      array.  */
2069   cp_cv_quals quals = TYPE_QUALS (type);
2070 
2071   if (quals & TYPE_QUAL_RESTRICT)
2072     {
2073       write_char ('r');
2074       ++num_qualifiers;
2075     }
2076   if (quals & TYPE_QUAL_VOLATILE)
2077     {
2078       write_char ('V');
2079       ++num_qualifiers;
2080     }
2081   if (quals & TYPE_QUAL_CONST)
2082     {
2083       write_char ('K');
2084       ++num_qualifiers;
2085     }
2086 
2087   return num_qualifiers;
2088 }
2089 
2090 /* Non-terminal <builtin-type>.
2091 
2092      <builtin-type> ::= v   # void
2093 		    ::= b   # bool
2094 		    ::= w   # wchar_t
2095 		    ::= c   # char
2096 		    ::= a   # signed char
2097 		    ::= h   # unsigned char
2098 		    ::= s   # short
2099 		    ::= t   # unsigned short
2100 		    ::= i   # int
2101 		    ::= j   # unsigned int
2102 		    ::= l   # long
2103 		    ::= m   # unsigned long
2104 		    ::= x   # long long, __int64
2105 		    ::= y   # unsigned long long, __int64
2106 		    ::= n   # __int128
2107 		    ::= o   # unsigned __int128
2108 		    ::= f   # float
2109 		    ::= d   # double
2110 		    ::= e   # long double, __float80
2111 		    ::= g   # __float128          [not supported]
2112 		    ::= u <source-name>  # vendor extended type */
2113 
2114 static void
2115 write_builtin_type (tree type)
2116 {
2117   if (TYPE_CANONICAL (type))
2118     type = TYPE_CANONICAL (type);
2119 
2120   switch (TREE_CODE (type))
2121     {
2122     case VOID_TYPE:
2123       write_char ('v');
2124       break;
2125 
2126     case BOOLEAN_TYPE:
2127       write_char ('b');
2128       break;
2129 
2130     case INTEGER_TYPE:
2131       /* TYPE may still be wchar_t, char16_t, or char32_t, since that
2132 	 isn't in integer_type_nodes.  */
2133       if (type == wchar_type_node)
2134 	write_char ('w');
2135       else if (type == char16_type_node)
2136 	write_string ("Ds");
2137       else if (type == char32_type_node)
2138 	write_string ("Di");
2139       else if (TYPE_FOR_JAVA (type))
2140 	write_java_integer_type_codes (type);
2141       else
2142 	{
2143 	  size_t itk;
2144 	  /* Assume TYPE is one of the shared integer type nodes.  Find
2145 	     it in the array of these nodes.  */
2146 	iagain:
2147 	  for (itk = 0; itk < itk_none; ++itk)
2148 	    if (integer_types[itk] != NULL_TREE
2149 		&& type == integer_types[itk])
2150 	      {
2151 		/* Print the corresponding single-letter code.  */
2152 		write_char (integer_type_codes[itk]);
2153 		break;
2154 	      }
2155 
2156 	  if (itk == itk_none)
2157 	    {
2158 	      tree t = c_common_type_for_mode (TYPE_MODE (type),
2159 					       TYPE_UNSIGNED (type));
2160 	      if (type != t)
2161 		{
2162 		  type = t;
2163 		  goto iagain;
2164 		}
2165 
2166 	      if (TYPE_PRECISION (type) == 128)
2167 		write_char (TYPE_UNSIGNED (type) ? 'o' : 'n');
2168 	      else
2169 		{
2170 		  /* Allow for cases where TYPE is not one of the shared
2171 		     integer type nodes and write a "vendor extended builtin
2172 		     type" with a name the form intN or uintN, respectively.
2173 		     Situations like this can happen if you have an
2174 		     __attribute__((__mode__(__SI__))) type and use exotic
2175 		     switches like '-mint8' on AVR.  Of course, this is
2176 		     undefined by the C++ ABI (and '-mint8' is not even
2177 		     Standard C conforming), but when using such special
2178 		     options you're pretty much in nowhere land anyway.  */
2179 		  const char *prefix;
2180 		  char prec[11];	/* up to ten digits for an unsigned */
2181 
2182 		  prefix = TYPE_UNSIGNED (type) ? "uint" : "int";
2183 		  sprintf (prec, "%u", (unsigned) TYPE_PRECISION (type));
2184 		  write_char ('u');	/* "vendor extended builtin type" */
2185 		  write_unsigned_number (strlen (prefix) + strlen (prec));
2186 		  write_string (prefix);
2187 		  write_string (prec);
2188 		}
2189 	    }
2190 	}
2191       break;
2192 
2193     case REAL_TYPE:
2194       if (type == float_type_node
2195 	  || type == java_float_type_node)
2196 	write_char ('f');
2197       else if (type == double_type_node
2198 	       || type == java_double_type_node)
2199 	write_char ('d');
2200       else if (type == long_double_type_node)
2201 	write_char ('e');
2202       else if (type == dfloat32_type_node)
2203 	write_string ("Df");
2204       else if (type == dfloat64_type_node)
2205 	write_string ("Dd");
2206       else if (type == dfloat128_type_node)
2207 	write_string ("De");
2208       else
2209 	gcc_unreachable ();
2210       break;
2211 
2212     case FIXED_POINT_TYPE:
2213       write_string ("DF");
2214       if (GET_MODE_IBIT (TYPE_MODE (type)) > 0)
2215 	write_unsigned_number (GET_MODE_IBIT (TYPE_MODE (type)));
2216       if (type == fract_type_node
2217 	  || type == sat_fract_type_node
2218 	  || type == accum_type_node
2219 	  || type == sat_accum_type_node)
2220 	write_char ('i');
2221       else if (type == unsigned_fract_type_node
2222 	       || type == sat_unsigned_fract_type_node
2223 	       || type == unsigned_accum_type_node
2224 	       || type == sat_unsigned_accum_type_node)
2225 	write_char ('j');
2226       else if (type == short_fract_type_node
2227 	       || type == sat_short_fract_type_node
2228 	       || type == short_accum_type_node
2229 	       || type == sat_short_accum_type_node)
2230 	write_char ('s');
2231       else if (type == unsigned_short_fract_type_node
2232 	       || type == sat_unsigned_short_fract_type_node
2233 	       || type == unsigned_short_accum_type_node
2234 	       || type == sat_unsigned_short_accum_type_node)
2235 	write_char ('t');
2236       else if (type == long_fract_type_node
2237 	       || type == sat_long_fract_type_node
2238 	       || type == long_accum_type_node
2239 	       || type == sat_long_accum_type_node)
2240 	write_char ('l');
2241       else if (type == unsigned_long_fract_type_node
2242 	       || type == sat_unsigned_long_fract_type_node
2243 	       || type == unsigned_long_accum_type_node
2244 	       || type == sat_unsigned_long_accum_type_node)
2245 	write_char ('m');
2246       else if (type == long_long_fract_type_node
2247 	       || type == sat_long_long_fract_type_node
2248 	       || type == long_long_accum_type_node
2249 	       || type == sat_long_long_accum_type_node)
2250 	write_char ('x');
2251       else if (type == unsigned_long_long_fract_type_node
2252 	       || type == sat_unsigned_long_long_fract_type_node
2253 	       || type == unsigned_long_long_accum_type_node
2254 	       || type == sat_unsigned_long_long_accum_type_node)
2255 	write_char ('y');
2256       else
2257 	sorry ("mangling unknown fixed point type");
2258       write_unsigned_number (GET_MODE_FBIT (TYPE_MODE (type)));
2259       if (TYPE_SATURATING (type))
2260 	write_char ('s');
2261       else
2262 	write_char ('n');
2263       break;
2264 
2265     default:
2266       gcc_unreachable ();
2267     }
2268 }
2269 
2270 /* Non-terminal <function-type>.  NODE is a FUNCTION_TYPE or
2271    METHOD_TYPE.  The return type is mangled before the parameter
2272    types.
2273 
2274      <function-type> ::= F [Y] <bare-function-type> E   */
2275 
2276 static void
2277 write_function_type (const tree type)
2278 {
2279   MANGLE_TRACE_TREE ("function-type", type);
2280 
2281   /* For a pointer to member function, the function type may have
2282      cv-qualifiers, indicating the quals for the artificial 'this'
2283      parameter.  */
2284   if (TREE_CODE (type) == METHOD_TYPE)
2285     {
2286       /* The first parameter must be a POINTER_TYPE pointing to the
2287 	 `this' parameter.  */
2288       tree this_type = class_of_this_parm (type);
2289       write_CV_qualifiers_for_type (this_type);
2290     }
2291 
2292   write_char ('F');
2293   /* We don't track whether or not a type is `extern "C"'.  Note that
2294      you can have an `extern "C"' function that does not have
2295      `extern "C"' type, and vice versa:
2296 
2297        extern "C" typedef void function_t();
2298        function_t f; // f has C++ linkage, but its type is
2299 		     // `extern "C"'
2300 
2301        typedef void function_t();
2302        extern "C" function_t f; // Vice versa.
2303 
2304      See [dcl.link].  */
2305   write_bare_function_type (type, /*include_return_type_p=*/1,
2306 			    /*decl=*/NULL);
2307   write_char ('E');
2308 }
2309 
2310 /* Non-terminal <bare-function-type>.  TYPE is a FUNCTION_TYPE or
2311    METHOD_TYPE.  If INCLUDE_RETURN_TYPE is nonzero, the return value
2312    is mangled before the parameter types.  If non-NULL, DECL is
2313    FUNCTION_DECL for the function whose type is being emitted.
2314 
2315    If DECL is a member of a Java type, then a literal 'J'
2316    is output and the return type is mangled as if INCLUDE_RETURN_TYPE
2317    were nonzero.
2318 
2319      <bare-function-type> ::= [J]</signature/ type>+  */
2320 
2321 static void
2322 write_bare_function_type (const tree type, const int include_return_type_p,
2323 			  const tree decl)
2324 {
2325   int java_method_p;
2326 
2327   MANGLE_TRACE_TREE ("bare-function-type", type);
2328 
2329   /* Detect Java methods and emit special encoding.  */
2330   if (decl != NULL
2331       && DECL_FUNCTION_MEMBER_P (decl)
2332       && TYPE_FOR_JAVA (DECL_CONTEXT (decl))
2333       && !DECL_CONSTRUCTOR_P (decl)
2334       && !DECL_DESTRUCTOR_P (decl)
2335       && !DECL_CONV_FN_P (decl))
2336     {
2337       java_method_p = 1;
2338       write_char ('J');
2339     }
2340   else
2341     {
2342       java_method_p = 0;
2343     }
2344 
2345   /* Mangle the return type, if requested.  */
2346   if (include_return_type_p || java_method_p)
2347     write_type (TREE_TYPE (type));
2348 
2349   /* Now mangle the types of the arguments.  */
2350   ++G.parm_depth;
2351   write_method_parms (TYPE_ARG_TYPES (type),
2352 		      TREE_CODE (type) == METHOD_TYPE,
2353 		      decl);
2354   --G.parm_depth;
2355 }
2356 
2357 /* Write the mangled representation of a method parameter list of
2358    types given in PARM_TYPES.  If METHOD_P is nonzero, the function is
2359    considered a non-static method, and the this parameter is omitted.
2360    If non-NULL, DECL is the FUNCTION_DECL for the function whose
2361    parameters are being emitted.  */
2362 
2363 static void
2364 write_method_parms (tree parm_types, const int method_p, const tree decl)
2365 {
2366   tree first_parm_type;
2367   tree parm_decl = decl ? DECL_ARGUMENTS (decl) : NULL_TREE;
2368 
2369   /* Assume this parameter type list is variable-length.  If it ends
2370      with a void type, then it's not.  */
2371   int varargs_p = 1;
2372 
2373   /* If this is a member function, skip the first arg, which is the
2374      this pointer.
2375        "Member functions do not encode the type of their implicit this
2376        parameter."
2377 
2378      Similarly, there's no need to mangle artificial parameters, like
2379      the VTT parameters for constructors and destructors.  */
2380   if (method_p)
2381     {
2382       parm_types = TREE_CHAIN (parm_types);
2383       parm_decl = parm_decl ? DECL_CHAIN (parm_decl) : NULL_TREE;
2384 
2385       while (parm_decl && DECL_ARTIFICIAL (parm_decl))
2386 	{
2387 	  parm_types = TREE_CHAIN (parm_types);
2388 	  parm_decl = DECL_CHAIN (parm_decl);
2389 	}
2390     }
2391 
2392   for (first_parm_type = parm_types;
2393        parm_types;
2394        parm_types = TREE_CHAIN (parm_types))
2395     {
2396       tree parm = TREE_VALUE (parm_types);
2397       if (parm == void_type_node)
2398 	{
2399 	  /* "Empty parameter lists, whether declared as () or
2400 	     conventionally as (void), are encoded with a void parameter
2401 	     (v)."  */
2402 	  if (parm_types == first_parm_type)
2403 	    write_type (parm);
2404 	  /* If the parm list is terminated with a void type, it's
2405 	     fixed-length.  */
2406 	  varargs_p = 0;
2407 	  /* A void type better be the last one.  */
2408 	  gcc_assert (TREE_CHAIN (parm_types) == NULL);
2409 	}
2410       else
2411 	write_type (parm);
2412     }
2413 
2414   if (varargs_p)
2415     /* <builtin-type> ::= z  # ellipsis  */
2416     write_char ('z');
2417 }
2418 
2419 /* <class-enum-type> ::= <name>  */
2420 
2421 static void
2422 write_class_enum_type (const tree type)
2423 {
2424   write_name (TYPE_NAME (type), /*ignore_local_scope=*/0);
2425 }
2426 
2427 /* Non-terminal <template-args>.  ARGS is a TREE_VEC of template
2428    arguments.
2429 
2430      <template-args> ::= I <template-arg>* E  */
2431 
2432 static void
2433 write_template_args (tree args)
2434 {
2435   int i;
2436   int length = 0;
2437 
2438   MANGLE_TRACE_TREE ("template-args", args);
2439 
2440   write_char ('I');
2441 
2442   if (args)
2443     length = TREE_VEC_LENGTH (args);
2444 
2445   if (args && TREE_CODE (TREE_VEC_ELT (args, 0)) == TREE_VEC)
2446     {
2447       /* We have nested template args.  We want the innermost template
2448 	 argument list.  */
2449       args = TREE_VEC_ELT (args, length - 1);
2450       length = TREE_VEC_LENGTH (args);
2451     }
2452   for (i = 0; i < length; ++i)
2453     write_template_arg (TREE_VEC_ELT (args, i));
2454 
2455   write_char ('E');
2456 }
2457 
2458 /* Write out the
2459    <unqualified-name>
2460    <unqualified-name> <template-args>
2461    part of SCOPE_REF or COMPONENT_REF mangling.  */
2462 
2463 static void
2464 write_member_name (tree member)
2465 {
2466   if (TREE_CODE (member) == IDENTIFIER_NODE)
2467     write_unqualified_id (member);
2468   else if (DECL_P (member))
2469     write_unqualified_name (member);
2470   else if (TREE_CODE (member) == TEMPLATE_ID_EXPR)
2471     {
2472       tree name = TREE_OPERAND (member, 0);
2473       if (TREE_CODE (name) == OVERLOAD)
2474 	name = OVL_FUNCTION (name);
2475       write_member_name (name);
2476       write_template_args (TREE_OPERAND (member, 1));
2477     }
2478   else
2479     write_expression (member);
2480 }
2481 
2482 /* <expression> ::= <unary operator-name> <expression>
2483 		::= <binary operator-name> <expression> <expression>
2484 		::= <expr-primary>
2485 
2486    <expr-primary> ::= <template-param>
2487 		  ::= L <type> <value number> E		# literal
2488 		  ::= L <mangled-name> E		# external name
2489 		  ::= st <type>				# sizeof
2490 		  ::= sr <type> <unqualified-name>	# dependent name
2491 		  ::= sr <type> <unqualified-name> <template-args> */
2492 
2493 static void
2494 write_expression (tree expr)
2495 {
2496   enum tree_code code = TREE_CODE (expr);
2497 
2498   /* Skip NOP_EXPRs.  They can occur when (say) a pointer argument
2499      is converted (via qualification conversions) to another
2500      type.  */
2501   while (TREE_CODE (expr) == NOP_EXPR
2502 	 || TREE_CODE (expr) == NON_LVALUE_EXPR)
2503     {
2504       expr = TREE_OPERAND (expr, 0);
2505       code = TREE_CODE (expr);
2506     }
2507 
2508   if (code == BASELINK
2509       && (!type_unknown_p (expr)
2510 	  || !BASELINK_QUALIFIED_P (expr)))
2511     {
2512       expr = BASELINK_FUNCTIONS (expr);
2513       code = TREE_CODE (expr);
2514     }
2515 
2516   /* Handle pointers-to-members by making them look like expression
2517      nodes.  */
2518   if (code == PTRMEM_CST)
2519     {
2520       expr = build_nt (ADDR_EXPR,
2521 		       build_qualified_name (/*type=*/NULL_TREE,
2522 					     PTRMEM_CST_CLASS (expr),
2523 					     PTRMEM_CST_MEMBER (expr),
2524 					     /*template_p=*/false));
2525       code = TREE_CODE (expr);
2526     }
2527 
2528   /* Handle template parameters.  */
2529   if (code == TEMPLATE_TYPE_PARM
2530       || code == TEMPLATE_TEMPLATE_PARM
2531       || code == BOUND_TEMPLATE_TEMPLATE_PARM
2532       || code == TEMPLATE_PARM_INDEX)
2533     write_template_param (expr);
2534   /* Handle literals.  */
2535   else if (TREE_CODE_CLASS (code) == tcc_constant
2536 	   || (abi_version_at_least (2) && code == CONST_DECL))
2537     write_template_arg_literal (expr);
2538   else if (code == PARM_DECL && DECL_ARTIFICIAL (expr))
2539     {
2540       gcc_assert (!strcmp ("this", IDENTIFIER_POINTER (DECL_NAME (expr))));
2541       write_string ("fpT");
2542     }
2543   else if (code == PARM_DECL)
2544     {
2545       /* A function parameter used in a late-specified return type.  */
2546       int index = DECL_PARM_INDEX (expr);
2547       int level = DECL_PARM_LEVEL (expr);
2548       int delta = G.parm_depth - level + 1;
2549       gcc_assert (index >= 1);
2550       write_char ('f');
2551       if (delta != 0)
2552 	{
2553 	  if (abi_version_at_least (5))
2554 	    {
2555 	      /* Let L be the number of function prototype scopes from the
2556 		 innermost one (in which the parameter reference occurs) up
2557 		 to (and including) the one containing the declaration of
2558 		 the referenced parameter.  If the parameter declaration
2559 		 clause of the innermost function prototype scope has been
2560 		 completely seen, it is not counted (in that case -- which
2561 		 is perhaps the most common -- L can be zero).  */
2562 	      write_char ('L');
2563 	      write_unsigned_number (delta - 1);
2564 	    }
2565 	  else
2566 	    G.need_abi_warning = true;
2567 	}
2568       write_char ('p');
2569       write_compact_number (index - 1);
2570     }
2571   else if (DECL_P (expr))
2572     {
2573       /* G++ 3.2 incorrectly mangled non-type template arguments of
2574 	 enumeration type using their names.  */
2575       if (code == CONST_DECL)
2576 	G.need_abi_warning = 1;
2577       write_char ('L');
2578       write_mangled_name (expr, false);
2579       write_char ('E');
2580     }
2581   else if (TREE_CODE (expr) == SIZEOF_EXPR
2582 	   && TYPE_P (TREE_OPERAND (expr, 0)))
2583     {
2584       write_string ("st");
2585       write_type (TREE_OPERAND (expr, 0));
2586     }
2587   else if (TREE_CODE (expr) == ALIGNOF_EXPR
2588 	   && TYPE_P (TREE_OPERAND (expr, 0)))
2589     {
2590       write_string ("at");
2591       write_type (TREE_OPERAND (expr, 0));
2592     }
2593   else if (code == SCOPE_REF
2594 	   || code == BASELINK)
2595     {
2596       tree scope, member;
2597       if (code == SCOPE_REF)
2598 	{
2599 	  scope = TREE_OPERAND (expr, 0);
2600 	  member = TREE_OPERAND (expr, 1);
2601 	}
2602       else
2603 	{
2604 	  scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (expr));
2605 	  member = BASELINK_FUNCTIONS (expr);
2606 	}
2607 
2608       if (!abi_version_at_least (2) && DECL_P (member))
2609 	{
2610 	  write_string ("sr");
2611 	  write_type (scope);
2612 	  /* G++ 3.2 incorrectly put out both the "sr" code and
2613 	     the nested name of the qualified name.  */
2614 	  G.need_abi_warning = 1;
2615 	  write_encoding (member);
2616 	}
2617 
2618       /* If the MEMBER is a real declaration, then the qualifying
2619 	 scope was not dependent.  Ideally, we would not have a
2620 	 SCOPE_REF in those cases, but sometimes we do.  If the second
2621 	 argument is a DECL, then the name must not have been
2622 	 dependent.  */
2623       else if (DECL_P (member))
2624 	write_expression (member);
2625       else
2626 	{
2627 	  write_string ("sr");
2628 	  write_type (scope);
2629 	  write_member_name (member);
2630 	}
2631     }
2632   else if (TREE_CODE (expr) == INDIRECT_REF
2633 	   && TREE_TYPE (TREE_OPERAND (expr, 0))
2634 	   && TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE)
2635     {
2636       write_expression (TREE_OPERAND (expr, 0));
2637     }
2638   else if (TREE_CODE (expr) == IDENTIFIER_NODE)
2639     {
2640       /* An operator name appearing as a dependent name needs to be
2641 	 specially marked to disambiguate between a use of the operator
2642 	 name and a use of the operator in an expression.  */
2643       if (IDENTIFIER_OPNAME_P (expr))
2644 	write_string ("on");
2645       write_unqualified_id (expr);
2646     }
2647   else if (TREE_CODE (expr) == TEMPLATE_ID_EXPR)
2648     {
2649       tree fn = TREE_OPERAND (expr, 0);
2650       if (is_overloaded_fn (fn))
2651 	fn = DECL_NAME (get_first_fn (fn));
2652       if (IDENTIFIER_OPNAME_P (fn))
2653 	write_string ("on");
2654       write_unqualified_id (fn);
2655       write_template_args (TREE_OPERAND (expr, 1));
2656     }
2657   else if (TREE_CODE (expr) == MODOP_EXPR)
2658     {
2659       enum tree_code subop = TREE_CODE (TREE_OPERAND (expr, 1));
2660       const char *name = (assignment_operator_name_info[(int) subop]
2661 			  .mangled_name);
2662       write_string (name);
2663       write_expression (TREE_OPERAND (expr, 0));
2664       write_expression (TREE_OPERAND (expr, 2));
2665     }
2666   else if (code == NEW_EXPR || code == VEC_NEW_EXPR)
2667     {
2668       /* ::= [gs] nw <expression>* _ <type> E
2669 	 ::= [gs] nw <expression>* _ <type> <initializer>
2670 	 ::= [gs] na <expression>* _ <type> E
2671 	 ::= [gs] na <expression>* _ <type> <initializer>
2672 	 <initializer> ::= pi <expression>* E  */
2673       tree placement = TREE_OPERAND (expr, 0);
2674       tree type = TREE_OPERAND (expr, 1);
2675       tree nelts = TREE_OPERAND (expr, 2);
2676       tree init = TREE_OPERAND (expr, 3);
2677       tree t;
2678 
2679       gcc_assert (code == NEW_EXPR);
2680       if (TREE_OPERAND (expr, 2))
2681 	code = VEC_NEW_EXPR;
2682 
2683       if (NEW_EXPR_USE_GLOBAL (expr))
2684 	write_string ("gs");
2685 
2686       write_string (operator_name_info[(int) code].mangled_name);
2687 
2688       for (t = placement; t; t = TREE_CHAIN (t))
2689 	write_expression (TREE_VALUE (t));
2690 
2691       write_char ('_');
2692 
2693       if (nelts)
2694 	{
2695 	  tree domain;
2696 	  ++processing_template_decl;
2697 	  domain = compute_array_index_type (NULL_TREE, nelts,
2698 					     tf_warning_or_error);
2699 	  type = build_cplus_array_type (type, domain);
2700 	  --processing_template_decl;
2701 	}
2702       write_type (type);
2703 
2704       if (init && TREE_CODE (init) == TREE_LIST
2705 	  && TREE_CODE (TREE_VALUE (init)) == CONSTRUCTOR
2706 	  && CONSTRUCTOR_IS_DIRECT_INIT (TREE_VALUE (init)))
2707 	write_expression (TREE_VALUE (init));
2708       else
2709 	{
2710 	  if (init)
2711 	    write_string ("pi");
2712 	  if (init && init != void_zero_node)
2713 	    for (t = init; t; t = TREE_CHAIN (t))
2714 	      write_expression (TREE_VALUE (t));
2715 	  write_char ('E');
2716 	}
2717     }
2718   else if (code == DELETE_EXPR || code == VEC_DELETE_EXPR)
2719     {
2720       gcc_assert (code == DELETE_EXPR);
2721       if (DELETE_EXPR_USE_VEC (expr))
2722 	code = VEC_DELETE_EXPR;
2723 
2724       if (DELETE_EXPR_USE_GLOBAL (expr))
2725 	write_string ("gs");
2726 
2727       write_string (operator_name_info[(int) code].mangled_name);
2728 
2729       write_expression (TREE_OPERAND (expr, 0));
2730     }
2731   else if (code == THROW_EXPR)
2732     {
2733       tree op = TREE_OPERAND (expr, 0);
2734       if (op)
2735 	{
2736 	  write_string ("tw");
2737 	  write_expression (op);
2738 	}
2739       else
2740 	write_string ("tr");
2741     }
2742   else if (code == CONSTRUCTOR)
2743     {
2744       VEC(constructor_elt,gc)* elts = CONSTRUCTOR_ELTS (expr);
2745       unsigned i; tree val;
2746 
2747       if (BRACE_ENCLOSED_INITIALIZER_P (expr))
2748 	write_string ("il");
2749       else
2750 	{
2751 	  write_string ("tl");
2752 	  write_type (TREE_TYPE (expr));
2753 	}
2754       FOR_EACH_CONSTRUCTOR_VALUE (elts, i, val)
2755 	write_expression (val);
2756       write_char ('E');
2757     }
2758   else if (dependent_name (expr))
2759     {
2760       write_unqualified_id (dependent_name (expr));
2761     }
2762   else
2763     {
2764       int i, len;
2765       const char *name;
2766 
2767       /* When we bind a variable or function to a non-type template
2768 	 argument with reference type, we create an ADDR_EXPR to show
2769 	 the fact that the entity's address has been taken.  But, we
2770 	 don't actually want to output a mangling code for the `&'.  */
2771       if (TREE_CODE (expr) == ADDR_EXPR
2772 	  && TREE_TYPE (expr)
2773 	  && TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE)
2774 	{
2775 	  expr = TREE_OPERAND (expr, 0);
2776 	  if (DECL_P (expr))
2777 	    {
2778 	      write_expression (expr);
2779 	      return;
2780 	    }
2781 
2782 	  code = TREE_CODE (expr);
2783 	}
2784 
2785       if (code == COMPONENT_REF)
2786 	{
2787 	  tree ob = TREE_OPERAND (expr, 0);
2788 
2789 	  if (TREE_CODE (ob) == ARROW_EXPR)
2790 	    {
2791 	      write_string (operator_name_info[(int)code].mangled_name);
2792 	      ob = TREE_OPERAND (ob, 0);
2793 	    }
2794 	  else
2795 	    write_string ("dt");
2796 
2797 	  write_expression (ob);
2798 	  write_member_name (TREE_OPERAND (expr, 1));
2799 	  return;
2800 	}
2801 
2802       /* If it wasn't any of those, recursively expand the expression.  */
2803       name = operator_name_info[(int) code].mangled_name;
2804 
2805       /* We used to mangle const_cast and static_cast like a C cast.  */
2806       if (!abi_version_at_least (6)
2807 	  && (code == CONST_CAST_EXPR
2808 	      || code == STATIC_CAST_EXPR))
2809 	{
2810 	  name = operator_name_info[CAST_EXPR].mangled_name;
2811 	  G.need_abi_warning = 1;
2812 	}
2813 
2814       if (name == NULL)
2815 	{
2816 	  sorry ("mangling %C", code);
2817 	  return;
2818 	}
2819       else
2820 	write_string (name);
2821 
2822       switch (code)
2823 	{
2824 	case CALL_EXPR:
2825 	  {
2826 	    tree fn = CALL_EXPR_FN (expr);
2827 
2828 	    if (TREE_CODE (fn) == ADDR_EXPR)
2829 	      fn = TREE_OPERAND (fn, 0);
2830 
2831 	    /* Mangle a dependent name as the name, not whatever happens to
2832 	       be the first function in the overload set.  */
2833 	    if ((TREE_CODE (fn) == FUNCTION_DECL
2834 		 || TREE_CODE (fn) == OVERLOAD)
2835 		&& type_dependent_expression_p_push (expr))
2836 	      fn = DECL_NAME (get_first_fn (fn));
2837 
2838 	    write_expression (fn);
2839 	  }
2840 
2841 	  for (i = 0; i < call_expr_nargs (expr); ++i)
2842 	    write_expression (CALL_EXPR_ARG (expr, i));
2843 	  write_char ('E');
2844 	  break;
2845 
2846 	case CAST_EXPR:
2847 	  write_type (TREE_TYPE (expr));
2848 	  if (list_length (TREE_OPERAND (expr, 0)) == 1)
2849 	    write_expression (TREE_VALUE (TREE_OPERAND (expr, 0)));
2850 	  else
2851 	    {
2852 	      tree args = TREE_OPERAND (expr, 0);
2853 	      write_char ('_');
2854 	      for (; args; args = TREE_CHAIN (args))
2855 		write_expression (TREE_VALUE (args));
2856 	      write_char ('E');
2857 	    }
2858 	  break;
2859 
2860 	case DYNAMIC_CAST_EXPR:
2861 	case REINTERPRET_CAST_EXPR:
2862 	case STATIC_CAST_EXPR:
2863 	case CONST_CAST_EXPR:
2864 	  write_type (TREE_TYPE (expr));
2865 	  write_expression (TREE_OPERAND (expr, 0));
2866 	  break;
2867 
2868 	case PREINCREMENT_EXPR:
2869 	case PREDECREMENT_EXPR:
2870 	  if (abi_version_at_least (6))
2871 	    write_char ('_');
2872 	  else
2873 	    G.need_abi_warning = 1;
2874 	  /* Fall through.  */
2875 
2876 	default:
2877 	  /* In the middle-end, some expressions have more operands than
2878 	     they do in templates (and mangling).  */
2879 	  len = cp_tree_operand_length (expr);
2880 
2881 	  for (i = 0; i < len; ++i)
2882 	    {
2883 	      tree operand = TREE_OPERAND (expr, i);
2884 	      /* As a GNU extension, the middle operand of a
2885 		 conditional may be omitted.  Since expression
2886 		 manglings are supposed to represent the input token
2887 		 stream, there's no good way to mangle such an
2888 		 expression without extending the C++ ABI.  */
2889 	      if (code == COND_EXPR && i == 1 && !operand)
2890 		{
2891 		  error ("omitted middle operand to %<?:%> operand "
2892 			 "cannot be mangled");
2893 		  continue;
2894 		}
2895 	      write_expression (operand);
2896 	    }
2897 	}
2898     }
2899 }
2900 
2901 /* Literal subcase of non-terminal <template-arg>.
2902 
2903      "Literal arguments, e.g. "A<42L>", are encoded with their type
2904      and value. Negative integer values are preceded with "n"; for
2905      example, "A<-42L>" becomes "1AILln42EE". The bool value false is
2906      encoded as 0, true as 1."  */
2907 
2908 static void
2909 write_template_arg_literal (const tree value)
2910 {
2911   write_char ('L');
2912   write_type (TREE_TYPE (value));
2913 
2914   /* Write a null member pointer value as (type)0, regardless of its
2915      real representation.  */
2916   if (null_member_pointer_value_p (value))
2917     write_integer_cst (integer_zero_node);
2918   else
2919     switch (TREE_CODE (value))
2920       {
2921       case CONST_DECL:
2922 	write_integer_cst (DECL_INITIAL (value));
2923 	break;
2924 
2925       case INTEGER_CST:
2926 	gcc_assert (!same_type_p (TREE_TYPE (value), boolean_type_node)
2927 		    || integer_zerop (value) || integer_onep (value));
2928 	write_integer_cst (value);
2929 	break;
2930 
2931       case REAL_CST:
2932 	write_real_cst (value);
2933 	break;
2934 
2935       case COMPLEX_CST:
2936 	if (TREE_CODE (TREE_REALPART (value)) == INTEGER_CST
2937 	    && TREE_CODE (TREE_IMAGPART (value)) == INTEGER_CST)
2938 	  {
2939 	    write_integer_cst (TREE_REALPART (value));
2940 	    write_char ('_');
2941 	    write_integer_cst (TREE_IMAGPART (value));
2942 	  }
2943 	else if (TREE_CODE (TREE_REALPART (value)) == REAL_CST
2944 		 && TREE_CODE (TREE_IMAGPART (value)) == REAL_CST)
2945 	  {
2946 	    write_real_cst (TREE_REALPART (value));
2947 	    write_char ('_');
2948 	    write_real_cst (TREE_IMAGPART (value));
2949 	  }
2950 	else
2951 	  gcc_unreachable ();
2952 	break;
2953 
2954       case STRING_CST:
2955 	sorry ("string literal in function template signature");
2956 	break;
2957 
2958       default:
2959 	gcc_unreachable ();
2960       }
2961 
2962   write_char ('E');
2963 }
2964 
2965 /* Non-terminal <template-arg>.
2966 
2967      <template-arg> ::= <type>				# type
2968 		    ::= L <type> </value/ number> E	# literal
2969 		    ::= LZ <name> E			# external name
2970 		    ::= X <expression> E		# expression  */
2971 
2972 static void
2973 write_template_arg (tree node)
2974 {
2975   enum tree_code code = TREE_CODE (node);
2976 
2977   MANGLE_TRACE_TREE ("template-arg", node);
2978 
2979   /* A template template parameter's argument list contains TREE_LIST
2980      nodes of which the value field is the actual argument.  */
2981   if (code == TREE_LIST)
2982     {
2983       node = TREE_VALUE (node);
2984       /* If it's a decl, deal with its type instead.  */
2985       if (DECL_P (node))
2986 	{
2987 	  node = TREE_TYPE (node);
2988 	  code = TREE_CODE (node);
2989 	}
2990     }
2991 
2992   if (TREE_CODE (node) == NOP_EXPR
2993       && TREE_CODE (TREE_TYPE (node)) == REFERENCE_TYPE)
2994     {
2995       /* Template parameters can be of reference type. To maintain
2996 	 internal consistency, such arguments use a conversion from
2997 	 address of object to reference type.  */
2998       gcc_assert (TREE_CODE (TREE_OPERAND (node, 0)) == ADDR_EXPR);
2999       if (abi_version_at_least (2))
3000 	node = TREE_OPERAND (TREE_OPERAND (node, 0), 0);
3001       else
3002 	G.need_abi_warning = 1;
3003     }
3004 
3005   if (TREE_CODE (node) == BASELINK
3006       && !type_unknown_p (node))
3007     {
3008       if (abi_version_at_least (6))
3009 	node = BASELINK_FUNCTIONS (node);
3010       else
3011 	/* We wrongly wrapped a class-scope function in X/E.  */
3012 	G.need_abi_warning = 1;
3013     }
3014 
3015   if (ARGUMENT_PACK_P (node))
3016     {
3017       /* Expand the template argument pack. */
3018       tree args = ARGUMENT_PACK_ARGS (node);
3019       int i, length = TREE_VEC_LENGTH (args);
3020       if (abi_version_at_least (6))
3021 	write_char ('J');
3022       else
3023 	{
3024 	  write_char ('I');
3025 	  G.need_abi_warning = 1;
3026 	}
3027       for (i = 0; i < length; ++i)
3028         write_template_arg (TREE_VEC_ELT (args, i));
3029       write_char ('E');
3030     }
3031   else if (TYPE_P (node))
3032     write_type (node);
3033   else if (code == TEMPLATE_DECL)
3034     /* A template appearing as a template arg is a template template arg.  */
3035     write_template_template_arg (node);
3036   else if ((TREE_CODE_CLASS (code) == tcc_constant && code != PTRMEM_CST)
3037 	   || (abi_version_at_least (2) && code == CONST_DECL)
3038 	   || null_member_pointer_value_p (node))
3039     write_template_arg_literal (node);
3040   else if (DECL_P (node))
3041     {
3042       /* Until ABI version 2, non-type template arguments of
3043 	 enumeration type were mangled using their names.  */
3044       if (code == CONST_DECL && !abi_version_at_least (2))
3045 	G.need_abi_warning = 1;
3046       write_char ('L');
3047       /* Until ABI version 3, the underscore before the mangled name
3048 	 was incorrectly omitted.  */
3049       if (!abi_version_at_least (3))
3050 	{
3051 	  G.need_abi_warning = 1;
3052 	  write_char ('Z');
3053 	}
3054       else
3055 	write_string ("_Z");
3056       write_encoding (node);
3057       write_char ('E');
3058     }
3059   else
3060     {
3061       /* Template arguments may be expressions.  */
3062       write_char ('X');
3063       write_expression (node);
3064       write_char ('E');
3065     }
3066 }
3067 
3068 /*  <template-template-arg>
3069 			::= <name>
3070 			::= <substitution>  */
3071 
3072 static void
3073 write_template_template_arg (const tree decl)
3074 {
3075   MANGLE_TRACE_TREE ("template-template-arg", decl);
3076 
3077   if (find_substitution (decl))
3078     return;
3079   write_name (decl, /*ignore_local_scope=*/0);
3080   add_substitution (decl);
3081 }
3082 
3083 
3084 /* Non-terminal <array-type>.  TYPE is an ARRAY_TYPE.
3085 
3086      <array-type> ::= A [</dimension/ number>] _ </element/ type>
3087 		  ::= A <expression> _ </element/ type>
3088 
3089      "Array types encode the dimension (number of elements) and the
3090      element type. For variable length arrays, the dimension (but not
3091      the '_' separator) is omitted."  */
3092 
3093 static void
3094 write_array_type (const tree type)
3095 {
3096   write_char ('A');
3097   if (TYPE_DOMAIN (type))
3098     {
3099       tree index_type;
3100       tree max;
3101 
3102       index_type = TYPE_DOMAIN (type);
3103       /* The INDEX_TYPE gives the upper and lower bounds of the
3104 	 array.  */
3105       max = TYPE_MAX_VALUE (index_type);
3106       if (TREE_CODE (max) == INTEGER_CST)
3107 	{
3108 	  /* The ABI specifies that we should mangle the number of
3109 	     elements in the array, not the largest allowed index.  */
3110 	  double_int dmax
3111 	    = double_int_add (tree_to_double_int (max), double_int_one);
3112 	  /* Truncate the result - this will mangle [0, SIZE_INT_MAX]
3113 	     number of elements as zero.  */
3114 	  dmax = double_int_zext (dmax, TYPE_PRECISION (TREE_TYPE (max)));
3115 	  gcc_assert (double_int_fits_in_uhwi_p (dmax));
3116 	  write_unsigned_number (dmax.low);
3117 	}
3118       else
3119 	{
3120 	  max = TREE_OPERAND (max, 0);
3121 	  if (!abi_version_at_least (2))
3122 	    {
3123 	      /* value_dependent_expression_p presumes nothing is
3124 		 dependent when PROCESSING_TEMPLATE_DECL is zero.  */
3125 	      ++processing_template_decl;
3126 	      if (!value_dependent_expression_p (max))
3127 		G.need_abi_warning = 1;
3128 	      --processing_template_decl;
3129 	    }
3130 	  write_expression (max);
3131 	}
3132 
3133     }
3134   write_char ('_');
3135   write_type (TREE_TYPE (type));
3136 }
3137 
3138 /* Non-terminal <pointer-to-member-type> for pointer-to-member
3139    variables.  TYPE is a pointer-to-member POINTER_TYPE.
3140 
3141      <pointer-to-member-type> ::= M </class/ type> </member/ type>  */
3142 
3143 static void
3144 write_pointer_to_member_type (const tree type)
3145 {
3146   write_char ('M');
3147   write_type (TYPE_PTRMEM_CLASS_TYPE (type));
3148   write_type (TYPE_PTRMEM_POINTED_TO_TYPE (type));
3149 }
3150 
3151 /* Non-terminal <template-param>.  PARM is a TEMPLATE_TYPE_PARM,
3152    TEMPLATE_TEMPLATE_PARM, BOUND_TEMPLATE_TEMPLATE_PARM or a
3153    TEMPLATE_PARM_INDEX.
3154 
3155      <template-param> ::= T </parameter/ number> _  */
3156 
3157 static void
3158 write_template_param (const tree parm)
3159 {
3160   int parm_index;
3161 
3162   MANGLE_TRACE_TREE ("template-parm", parm);
3163 
3164   switch (TREE_CODE (parm))
3165     {
3166     case TEMPLATE_TYPE_PARM:
3167     case TEMPLATE_TEMPLATE_PARM:
3168     case BOUND_TEMPLATE_TEMPLATE_PARM:
3169       parm_index = TEMPLATE_TYPE_IDX (parm);
3170       break;
3171 
3172     case TEMPLATE_PARM_INDEX:
3173       parm_index = TEMPLATE_PARM_IDX (parm);
3174       break;
3175 
3176     default:
3177       gcc_unreachable ();
3178     }
3179 
3180   write_char ('T');
3181   /* NUMBER as it appears in the mangling is (-1)-indexed, with the
3182      earliest template param denoted by `_'.  */
3183   write_compact_number (parm_index);
3184 }
3185 
3186 /*  <template-template-param>
3187 			::= <template-param>
3188 			::= <substitution>  */
3189 
3190 static void
3191 write_template_template_param (const tree parm)
3192 {
3193   tree templ = NULL_TREE;
3194 
3195   /* PARM, a TEMPLATE_TEMPLATE_PARM, is an instantiation of the
3196      template template parameter.  The substitution candidate here is
3197      only the template.  */
3198   if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
3199     {
3200       templ
3201 	= TI_TEMPLATE (TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (parm));
3202       if (find_substitution (templ))
3203 	return;
3204     }
3205 
3206   /* <template-param> encodes only the template parameter position,
3207      not its template arguments, which is fine here.  */
3208   write_template_param (parm);
3209   if (templ)
3210     add_substitution (templ);
3211 }
3212 
3213 /* Non-terminal <substitution>.
3214 
3215       <substitution> ::= S <seq-id> _
3216 		     ::= S_  */
3217 
3218 static void
3219 write_substitution (const int seq_id)
3220 {
3221   MANGLE_TRACE ("substitution", "");
3222 
3223   write_char ('S');
3224   if (seq_id > 0)
3225     write_number (seq_id - 1, /*unsigned=*/1, 36);
3226   write_char ('_');
3227 }
3228 
3229 /* Start mangling ENTITY.  */
3230 
3231 static inline void
3232 start_mangling (const tree entity)
3233 {
3234   G.entity = entity;
3235   G.need_abi_warning = false;
3236   obstack_free (&name_obstack, name_base);
3237   mangle_obstack = &name_obstack;
3238   name_base = obstack_alloc (&name_obstack, 0);
3239 }
3240 
3241 /* Done with mangling. If WARN is true, and the name of G.entity will
3242    be mangled differently in a future version of the ABI, issue a
3243    warning.  */
3244 
3245 static void
3246 finish_mangling_internal (const bool warn)
3247 {
3248   if (warn_abi && warn && G.need_abi_warning)
3249     warning (OPT_Wabi, "the mangled name of %qD will change in a future "
3250 	     "version of GCC",
3251 	     G.entity);
3252 
3253   /* Clear all the substitutions.  */
3254   VEC_truncate (tree, G.substitutions, 0);
3255 
3256   /* Null-terminate the string.  */
3257   write_char ('\0');
3258 }
3259 
3260 
3261 /* Like finish_mangling_internal, but return the mangled string.  */
3262 
3263 static inline const char *
3264 finish_mangling (const bool warn)
3265 {
3266   finish_mangling_internal (warn);
3267   return (const char *) obstack_finish (mangle_obstack);
3268 }
3269 
3270 /* Like finish_mangling_internal, but return an identifier.  */
3271 
3272 static tree
3273 finish_mangling_get_identifier (const bool warn)
3274 {
3275   finish_mangling_internal (warn);
3276   /* Don't obstack_finish here, and the next start_mangling will
3277      remove the identifier.  */
3278   return get_identifier ((const char *) obstack_base (mangle_obstack));
3279 }
3280 
3281 /* Initialize data structures for mangling.  */
3282 
3283 void
3284 init_mangle (void)
3285 {
3286   gcc_obstack_init (&name_obstack);
3287   name_base = obstack_alloc (&name_obstack, 0);
3288   G.substitutions = NULL;
3289 
3290   /* Cache these identifiers for quick comparison when checking for
3291      standard substitutions.  */
3292   subst_identifiers[SUBID_ALLOCATOR] = get_identifier ("allocator");
3293   subst_identifiers[SUBID_BASIC_STRING] = get_identifier ("basic_string");
3294   subst_identifiers[SUBID_CHAR_TRAITS] = get_identifier ("char_traits");
3295   subst_identifiers[SUBID_BASIC_ISTREAM] = get_identifier ("basic_istream");
3296   subst_identifiers[SUBID_BASIC_OSTREAM] = get_identifier ("basic_ostream");
3297   subst_identifiers[SUBID_BASIC_IOSTREAM] = get_identifier ("basic_iostream");
3298 }
3299 
3300 /* Generate the mangled name of DECL.  */
3301 
3302 static tree
3303 mangle_decl_string (const tree decl)
3304 {
3305   tree result;
3306   location_t saved_loc = input_location;
3307   tree saved_fn = NULL_TREE;
3308   bool template_p = false;
3309 
3310   /* We shouldn't be trying to mangle an uninstantiated template.  */
3311   gcc_assert (!type_dependent_expression_p (decl));
3312 
3313   if (DECL_LANG_SPECIFIC (decl) && DECL_USE_TEMPLATE (decl))
3314     {
3315       struct tinst_level *tl = current_instantiation ();
3316       if ((!tl || tl->decl != decl)
3317 	  && push_tinst_level (decl))
3318 	{
3319 	  template_p = true;
3320 	  saved_fn = current_function_decl;
3321 	  current_function_decl = NULL_TREE;
3322 	}
3323     }
3324   input_location = DECL_SOURCE_LOCATION (decl);
3325 
3326   start_mangling (decl);
3327 
3328   if (TREE_CODE (decl) == TYPE_DECL)
3329     write_type (TREE_TYPE (decl));
3330   else
3331     write_mangled_name (decl, true);
3332 
3333   result = finish_mangling_get_identifier (/*warn=*/true);
3334   if (DEBUG_MANGLE)
3335     fprintf (stderr, "mangle_decl_string = '%s'\n\n",
3336 	     IDENTIFIER_POINTER (result));
3337 
3338   if (template_p)
3339     {
3340       pop_tinst_level ();
3341       current_function_decl = saved_fn;
3342     }
3343   input_location = saved_loc;
3344 
3345   return result;
3346 }
3347 
3348 /* Return an identifier for the external mangled name of DECL.  */
3349 
3350 static tree
3351 get_mangled_id (tree decl)
3352 {
3353   tree id = mangle_decl_string (decl);
3354   return targetm.mangle_decl_assembler_name (decl, id);
3355 }
3356 
3357 /* Create an identifier for the external mangled name of DECL.  */
3358 
3359 void
3360 mangle_decl (const tree decl)
3361 {
3362   tree id;
3363   bool dep;
3364 
3365   /* Don't bother mangling uninstantiated templates.  */
3366   ++processing_template_decl;
3367   if (TREE_CODE (decl) == TYPE_DECL)
3368     dep = dependent_type_p (TREE_TYPE (decl));
3369   else
3370     dep = (DECL_LANG_SPECIFIC (decl) && DECL_TEMPLATE_INFO (decl)
3371 	   && any_dependent_template_arguments_p (DECL_TI_ARGS (decl)));
3372   --processing_template_decl;
3373   if (dep)
3374     return;
3375 
3376   id = get_mangled_id (decl);
3377   SET_DECL_ASSEMBLER_NAME (decl, id);
3378 
3379   if (G.need_abi_warning
3380       /* Don't do this for a fake symbol we aren't going to emit anyway.  */
3381       && !DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (decl)
3382       && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (decl))
3383     {
3384 #ifdef ASM_OUTPUT_DEF
3385       /* If the mangling will change in the future, emit an alias with the
3386 	 future mangled name for forward-compatibility.  */
3387       int save_ver;
3388       tree id2, alias;
3389 #endif
3390 
3391       SET_IDENTIFIER_GLOBAL_VALUE (id, decl);
3392       if (IDENTIFIER_GLOBAL_VALUE (id) != decl)
3393 	inform (DECL_SOURCE_LOCATION (decl), "-fabi-version=6 (or =0) "
3394 		"avoids this error with a change in mangling");
3395 
3396 #ifdef ASM_OUTPUT_DEF
3397       save_ver = flag_abi_version;
3398       flag_abi_version = 0;
3399       id2 = mangle_decl_string (decl);
3400       id2 = targetm.mangle_decl_assembler_name (decl, id2);
3401       flag_abi_version = save_ver;
3402 
3403       alias = make_alias_for (decl, id2);
3404       DECL_IGNORED_P (alias) = 1;
3405       TREE_PUBLIC (alias) = TREE_PUBLIC (decl);
3406       DECL_VISIBILITY (alias) = DECL_VISIBILITY (decl);
3407       if (vague_linkage_p (decl))
3408 	DECL_WEAK (alias) = 1;
3409       if (TREE_CODE (decl) == FUNCTION_DECL)
3410 	cgraph_same_body_alias (cgraph_get_create_node (decl), alias, decl);
3411       else
3412 	varpool_extra_name_alias (alias, decl);
3413 #endif
3414     }
3415 }
3416 
3417 /* Generate the mangled representation of TYPE.  */
3418 
3419 const char *
3420 mangle_type_string (const tree type)
3421 {
3422   const char *result;
3423 
3424   start_mangling (type);
3425   write_type (type);
3426   result = finish_mangling (/*warn=*/false);
3427   if (DEBUG_MANGLE)
3428     fprintf (stderr, "mangle_type_string = '%s'\n\n", result);
3429   return result;
3430 }
3431 
3432 /* Create an identifier for the mangled name of a special component
3433    for belonging to TYPE.  CODE is the ABI-specified code for this
3434    component.  */
3435 
3436 static tree
3437 mangle_special_for_type (const tree type, const char *code)
3438 {
3439   tree result;
3440 
3441   /* We don't have an actual decl here for the special component, so
3442      we can't just process the <encoded-name>.  Instead, fake it.  */
3443   start_mangling (type);
3444 
3445   /* Start the mangling.  */
3446   write_string ("_Z");
3447   write_string (code);
3448 
3449   /* Add the type.  */
3450   write_type (type);
3451   result = finish_mangling_get_identifier (/*warn=*/false);
3452 
3453   if (DEBUG_MANGLE)
3454     fprintf (stderr, "mangle_special_for_type = %s\n\n",
3455 	     IDENTIFIER_POINTER (result));
3456 
3457   return result;
3458 }
3459 
3460 /* Create an identifier for the mangled representation of the typeinfo
3461    structure for TYPE.  */
3462 
3463 tree
3464 mangle_typeinfo_for_type (const tree type)
3465 {
3466   return mangle_special_for_type (type, "TI");
3467 }
3468 
3469 /* Create an identifier for the mangled name of the NTBS containing
3470    the mangled name of TYPE.  */
3471 
3472 tree
3473 mangle_typeinfo_string_for_type (const tree type)
3474 {
3475   return mangle_special_for_type (type, "TS");
3476 }
3477 
3478 /* Create an identifier for the mangled name of the vtable for TYPE.  */
3479 
3480 tree
3481 mangle_vtbl_for_type (const tree type)
3482 {
3483   return mangle_special_for_type (type, "TV");
3484 }
3485 
3486 /* Returns an identifier for the mangled name of the VTT for TYPE.  */
3487 
3488 tree
3489 mangle_vtt_for_type (const tree type)
3490 {
3491   return mangle_special_for_type (type, "TT");
3492 }
3493 
3494 /* Return an identifier for a construction vtable group.  TYPE is
3495    the most derived class in the hierarchy; BINFO is the base
3496    subobject for which this construction vtable group will be used.
3497 
3498    This mangling isn't part of the ABI specification; in the ABI
3499    specification, the vtable group is dumped in the same COMDAT as the
3500    main vtable, and is referenced only from that vtable, so it doesn't
3501    need an external name.  For binary formats without COMDAT sections,
3502    though, we need external names for the vtable groups.
3503 
3504    We use the production
3505 
3506     <special-name> ::= CT <type> <offset number> _ <base type>  */
3507 
3508 tree
3509 mangle_ctor_vtbl_for_type (const tree type, const tree binfo)
3510 {
3511   tree result;
3512 
3513   start_mangling (type);
3514 
3515   write_string ("_Z");
3516   write_string ("TC");
3517   write_type (type);
3518   write_integer_cst (BINFO_OFFSET (binfo));
3519   write_char ('_');
3520   write_type (BINFO_TYPE (binfo));
3521 
3522   result = finish_mangling_get_identifier (/*warn=*/false);
3523   if (DEBUG_MANGLE)
3524     fprintf (stderr, "mangle_ctor_vtbl_for_type = %s\n\n",
3525 	     IDENTIFIER_POINTER (result));
3526   return result;
3527 }
3528 
3529 /* Mangle a this pointer or result pointer adjustment.
3530 
3531    <call-offset> ::= h <fixed offset number> _
3532 		 ::= v <fixed offset number> _ <virtual offset number> _ */
3533 
3534 static void
3535 mangle_call_offset (const tree fixed_offset, const tree virtual_offset)
3536 {
3537   write_char (virtual_offset ? 'v' : 'h');
3538 
3539   /* For either flavor, write the fixed offset.  */
3540   write_integer_cst (fixed_offset);
3541   write_char ('_');
3542 
3543   /* For a virtual thunk, add the virtual offset.  */
3544   if (virtual_offset)
3545     {
3546       write_integer_cst (virtual_offset);
3547       write_char ('_');
3548     }
3549 }
3550 
3551 /* Return an identifier for the mangled name of a this-adjusting or
3552    covariant thunk to FN_DECL.  FIXED_OFFSET is the initial adjustment
3553    to this used to find the vptr.  If VIRTUAL_OFFSET is non-NULL, this
3554    is a virtual thunk, and it is the vtbl offset in
3555    bytes. THIS_ADJUSTING is nonzero for a this adjusting thunk and
3556    zero for a covariant thunk. Note, that FN_DECL might be a covariant
3557    thunk itself. A covariant thunk name always includes the adjustment
3558    for the this pointer, even if there is none.
3559 
3560    <special-name> ::= T <call-offset> <base encoding>
3561 		  ::= Tc <this_adjust call-offset> <result_adjust call-offset>
3562 					<base encoding>  */
3563 
3564 tree
3565 mangle_thunk (tree fn_decl, const int this_adjusting, tree fixed_offset,
3566 	      tree virtual_offset)
3567 {
3568   tree result;
3569 
3570   start_mangling (fn_decl);
3571 
3572   write_string ("_Z");
3573   write_char ('T');
3574 
3575   if (!this_adjusting)
3576     {
3577       /* Covariant thunk with no this adjustment */
3578       write_char ('c');
3579       mangle_call_offset (integer_zero_node, NULL_TREE);
3580       mangle_call_offset (fixed_offset, virtual_offset);
3581     }
3582   else if (!DECL_THUNK_P (fn_decl))
3583     /* Plain this adjusting thunk.  */
3584     mangle_call_offset (fixed_offset, virtual_offset);
3585   else
3586     {
3587       /* This adjusting thunk to covariant thunk.  */
3588       write_char ('c');
3589       mangle_call_offset (fixed_offset, virtual_offset);
3590       fixed_offset = ssize_int (THUNK_FIXED_OFFSET (fn_decl));
3591       virtual_offset = THUNK_VIRTUAL_OFFSET (fn_decl);
3592       if (virtual_offset)
3593 	virtual_offset = BINFO_VPTR_FIELD (virtual_offset);
3594       mangle_call_offset (fixed_offset, virtual_offset);
3595       fn_decl = THUNK_TARGET (fn_decl);
3596     }
3597 
3598   /* Scoped name.  */
3599   write_encoding (fn_decl);
3600 
3601   result = finish_mangling_get_identifier (/*warn=*/false);
3602   if (DEBUG_MANGLE)
3603     fprintf (stderr, "mangle_thunk = %s\n\n", IDENTIFIER_POINTER (result));
3604   return result;
3605 }
3606 
3607 /* This hash table maps TYPEs to the IDENTIFIER for a conversion
3608    operator to TYPE.  The nodes are IDENTIFIERs whose TREE_TYPE is the
3609    TYPE.  */
3610 
3611 static GTY ((param_is (union tree_node))) htab_t conv_type_names;
3612 
3613 /* Hash a node (VAL1) in the table.  */
3614 
3615 static hashval_t
3616 hash_type (const void *val)
3617 {
3618   return (hashval_t) TYPE_UID (TREE_TYPE ((const_tree) val));
3619 }
3620 
3621 /* Compare VAL1 (a node in the table) with VAL2 (a TYPE).  */
3622 
3623 static int
3624 compare_type (const void *val1, const void *val2)
3625 {
3626   return TREE_TYPE ((const_tree) val1) == (const_tree) val2;
3627 }
3628 
3629 /* Return an identifier for the mangled unqualified name for a
3630    conversion operator to TYPE.  This mangling is not specified by the
3631    ABI spec; it is only used internally.  */
3632 
3633 tree
3634 mangle_conv_op_name_for_type (const tree type)
3635 {
3636   void **slot;
3637   tree identifier;
3638 
3639   if (type == error_mark_node)
3640     return error_mark_node;
3641 
3642   if (conv_type_names == NULL)
3643     conv_type_names = htab_create_ggc (31, &hash_type, &compare_type, NULL);
3644 
3645   slot = htab_find_slot_with_hash (conv_type_names, type,
3646 				   (hashval_t) TYPE_UID (type), INSERT);
3647   identifier = (tree)*slot;
3648   if (!identifier)
3649     {
3650       char buffer[64];
3651 
3652        /* Create a unique name corresponding to TYPE.  */
3653       sprintf (buffer, "operator %lu",
3654 	       (unsigned long) htab_elements (conv_type_names));
3655       identifier = get_identifier (buffer);
3656       *slot = identifier;
3657 
3658       /* Hang TYPE off the identifier so it can be found easily later
3659 	 when performing conversions.  */
3660       TREE_TYPE (identifier) = type;
3661 
3662       /* Set bits on the identifier so we know later it's a conversion.  */
3663       IDENTIFIER_OPNAME_P (identifier) = 1;
3664       IDENTIFIER_TYPENAME_P (identifier) = 1;
3665     }
3666 
3667   return identifier;
3668 }
3669 
3670 /* Return an identifier for the name of an initialization guard
3671    variable for indicated VARIABLE.  */
3672 
3673 tree
3674 mangle_guard_variable (const tree variable)
3675 {
3676   start_mangling (variable);
3677   write_string ("_ZGV");
3678   if (strncmp (IDENTIFIER_POINTER (DECL_NAME (variable)), "_ZGR", 4) == 0)
3679     /* The name of a guard variable for a reference temporary should refer
3680        to the reference, not the temporary.  */
3681     write_string (IDENTIFIER_POINTER (DECL_NAME (variable)) + 4);
3682   else
3683     write_name (variable, /*ignore_local_scope=*/0);
3684   return finish_mangling_get_identifier (/*warn=*/false);
3685 }
3686 
3687 /* Return an identifier for the name of a temporary variable used to
3688    initialize a static reference.  This isn't part of the ABI, but we might
3689    as well call them something readable.  */
3690 
3691 static GTY(()) int temp_count;
3692 
3693 tree
3694 mangle_ref_init_variable (const tree variable)
3695 {
3696   start_mangling (variable);
3697   write_string ("_ZGR");
3698   write_name (variable, /*ignore_local_scope=*/0);
3699   /* Avoid name clashes with aggregate initialization of multiple
3700      references at once.  */
3701   write_unsigned_number (temp_count++);
3702   return finish_mangling_get_identifier (/*warn=*/false);
3703 }
3704 
3705 
3706 /* Foreign language type mangling section.  */
3707 
3708 /* How to write the type codes for the integer Java type.  */
3709 
3710 static void
3711 write_java_integer_type_codes (const tree type)
3712 {
3713   if (type == java_int_type_node)
3714     write_char ('i');
3715   else if (type == java_short_type_node)
3716     write_char ('s');
3717   else if (type == java_byte_type_node)
3718     write_char ('c');
3719   else if (type == java_char_type_node)
3720     write_char ('w');
3721   else if (type == java_long_type_node)
3722     write_char ('x');
3723   else if (type == java_boolean_type_node)
3724     write_char ('b');
3725   else
3726     gcc_unreachable ();
3727 }
3728 
3729 #include "gt-cp-mangle.h"
3730