gcc/cp/decl2.c

   1 /* Process declarations and variables for C++ compiler.
   2    Copyright (C) 1988-2020 Free Software Foundation, Inc.
   3    Hacked by Michael Tiemann (tiemann@cygnus.com)
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21
  22 /* Process declarations and symbol lookup for C++ front end.
  23    Also constructs types; the standard scalar types at initialization,
  24    and structure, union, array and enum types when they are declared.  */
  25
  26 /* ??? not all decl nodes are given the most useful possible
  27    line numbers.  For example, the CONST_DECLs for enum values.  */
  28
  29 #include "config.h"
  30 #include "system.h"
  31 #include "coretypes.h"
  32 #include "memmodel.h"
  33 #include "target.h"
  34 #include "cp-tree.h"
  35 #include "c-family/c-common.h"
  36 #include "timevar.h"
  37 #include "stringpool.h"
  38 #include "cgraph.h"
  39 #include "varasm.h"
  40 #include "attribs.h"
  41 #include "stor-layout.h"
  42 #include "calls.h"
  43 #include "decl.h"
  44 #include "toplev.h"
  45 #include "c-family/c-objc.h"
  46 #include "c-family/c-pragma.h"
  47 #include "dumpfile.h"
  48 #include "intl.h"
  49 #include "c-family/c-ada-spec.h"
  50 #include "asan.h"
  51
  52 /* Id for dumping the raw trees.  */
  53 int raw_dump_id;
  54
  55 extern cpp_reader *parse_in;
  56
  57 /* This structure contains information about the initializations
  58    and/or destructions required for a particular priority level.  */
  59 typedef struct priority_info_s {
  60   /* Nonzero if there have been any initializations at this priority
  61      throughout the translation unit.  */
  62   int initializations_p;
  63   /* Nonzero if there have been any destructions at this priority
  64      throughout the translation unit.  */
  65   int destructions_p;
  66 } *priority_info;
  67
  68 static void mark_vtable_entries (tree);
  69 static bool maybe_emit_vtables (tree);
  70 static tree start_objects (int, int);
  71 static void finish_objects (int, int, tree);
  72 static tree start_static_storage_duration_function (unsigned);
  73 static void finish_static_storage_duration_function (tree);
  74 static priority_info get_priority_info (int);
  75 static void do_static_initialization_or_destruction (tree, bool);
  76 static void one_static_initialization_or_destruction (tree, tree, bool);
  77 static void generate_ctor_or_dtor_function (bool, int, location_t *);
  78 static int generate_ctor_and_dtor_functions_for_priority (splay_tree_node,
  79                                                           void *);
  80 static tree prune_vars_needing_no_initialization (tree *);
  81 static void write_out_vars (tree);
  82 static void import_export_class (tree);
  83 static tree get_guard_bits (tree);
  84 static void determine_visibility_from_class (tree, tree);
  85 static bool determine_hidden_inline (tree);
  86 static void maybe_instantiate_decl (tree);
  87
  88 /* A list of static class variables.  This is needed, because a
  89    static class variable can be declared inside the class without
  90    an initializer, and then initialized, statically, outside the class.  */
  91 static GTY(()) vec<tree, va_gc> *pending_statics;
  92
  93 /* A list of functions which were declared inline, but which we
  94    may need to emit outline anyway.  */
  95 static GTY(()) vec<tree, va_gc> *deferred_fns;
  96
  97 /* A list of decls that use types with no linkage, which we need to make
  98    sure are defined.  */
  99 static GTY(()) vec<tree, va_gc> *no_linkage_decls;
 100
 101 /* A vector of alternating decls and identifiers, where the latter
 102    is to be an alias for the former if the former is defined.  */
 103 static GTY(()) vec<tree, va_gc> *mangling_aliases;
 104
 105 /* hash traits for declarations.  Hashes single decls via
 106    DECL_ASSEMBLER_NAME_RAW.  */
 107
 108 struct mangled_decl_hash : ggc_remove <tree>
 109 {
 110   typedef tree value_type; /* A DECL.  */
 111   typedef tree compare_type; /* An identifier.  */
 112
 113   static hashval_t hash (const value_type decl)
 114   {
 115     return IDENTIFIER_HASH_VALUE (DECL_ASSEMBLER_NAME_RAW (decl));
 116   }
 117   static bool equal (const value_type existing, compare_type candidate)
 118   {
 119     tree name = DECL_ASSEMBLER_NAME_RAW (existing);
 120     return candidate == name;
 121   }
 122
 123   static const bool empty_zero_p = true;
 124   static inline void mark_empty (value_type &p) {p = NULL_TREE;}
 125   static inline bool is_empty (value_type p) {return !p;}
 126
 127   static bool is_deleted (value_type e)
 128   {
 129     return e == reinterpret_cast <value_type> (1);
 130   }
 131   static void mark_deleted (value_type &e)
 132   {
 133     e = reinterpret_cast <value_type> (1);
 134   }
 135 };
 136
 137 /* A hash table of decls keyed by mangled name.  Used to figure out if
 138    we need compatibility aliases.  */
 139 static GTY(()) hash_table<mangled_decl_hash> *mangled_decls;
 140
 141 /* Nonzero if we're done parsing and into end-of-file activities.  */
 142
 143 int at_eof;
 144
 145 /* True if note_mangling_alias should enqueue mangling aliases for
 146    later generation, rather than emitting them right away.  */
 147
 148 bool defer_mangling_aliases = true;
 149 \f
 150
 151 /* Return a member function type (a METHOD_TYPE), given FNTYPE (a
 152    FUNCTION_TYPE), CTYPE (class type), and QUALS (the cv-qualifiers
 153    that apply to the function).  */
 154
 155 tree
 156 build_memfn_type (tree fntype, tree ctype, cp_cv_quals quals,
 157                   cp_ref_qualifier rqual)
 158 {
 159   if (fntype == error_mark_node || ctype == error_mark_node)
 160     return error_mark_node;
 161
 162   gcc_assert (FUNC_OR_METHOD_TYPE_P (fntype));
 163
 164   cp_cv_quals type_quals = quals & ~TYPE_QUAL_RESTRICT;
 165   ctype = cp_build_qualified_type (ctype, type_quals);
 166
 167   tree newtype
 168     = build_method_type_directly (ctype, TREE_TYPE (fntype),
 169                                   (TREE_CODE (fntype) == METHOD_TYPE
 170                                    ? TREE_CHAIN (TYPE_ARG_TYPES (fntype))
 171                                    : TYPE_ARG_TYPES (fntype)));
 172   if (tree attrs = TYPE_ATTRIBUTES (fntype))
 173     newtype = cp_build_type_attribute_variant (newtype, attrs);
 174   newtype = build_cp_fntype_variant (newtype, rqual,
 175                                      TYPE_RAISES_EXCEPTIONS (fntype),
 176                                      TYPE_HAS_LATE_RETURN_TYPE (fntype));
 177
 178   return newtype;
 179 }
 180
 181 /* Return a variant of FNTYPE, a FUNCTION_TYPE or METHOD_TYPE, with its
 182    return type changed to NEW_RET.  */
 183
 184 tree
 185 change_return_type (tree new_ret, tree fntype)
 186 {
 187   if (new_ret == error_mark_node)
 188     return fntype;
 189
 190   if (same_type_p (new_ret, TREE_TYPE (fntype)))
 191     return fntype;
 192
 193   tree newtype;
 194   tree args = TYPE_ARG_TYPES (fntype);
 195
 196   if (TREE_CODE (fntype) == FUNCTION_TYPE)
 197     {
 198       newtype = build_function_type (new_ret, args);
 199       newtype = apply_memfn_quals (newtype,
 200                                    type_memfn_quals (fntype));
 201     }
 202   else
 203     newtype = build_method_type_directly
 204       (class_of_this_parm (fntype), new_ret, TREE_CHAIN (args));
 205
 206   if (tree attrs = TYPE_ATTRIBUTES (fntype))
 207     newtype = cp_build_type_attribute_variant (newtype, attrs);
 208   newtype = cxx_copy_lang_qualifiers (newtype, fntype);
 209
 210   return newtype;
 211 }
 212
 213 /* Build a PARM_DECL of FN with NAME and TYPE, and set DECL_ARG_TYPE
 214    appropriately.  */
 215
 216 tree
 217 cp_build_parm_decl (tree fn, tree name, tree type)
 218 {
 219   tree parm = build_decl (input_location,
 220                           PARM_DECL, name, type);
 221   DECL_CONTEXT (parm) = fn;
 222
 223   /* DECL_ARG_TYPE is only used by the back end and the back end never
 224      sees templates.  */
 225   if (!processing_template_decl)
 226     DECL_ARG_TYPE (parm) = type_passed_as (type);
 227
 228   return parm;
 229 }
 230
 231 /* Returns a PARM_DECL of FN for a parameter of the indicated TYPE, with the
 232    indicated NAME.  */
 233
 234 tree
 235 build_artificial_parm (tree fn, tree name, tree type)
 236 {
 237   tree parm = cp_build_parm_decl (fn, name, type);
 238   DECL_ARTIFICIAL (parm) = 1;
 239   /* All our artificial parms are implicitly `const'; they cannot be
 240      assigned to.  */
 241   TREE_READONLY (parm) = 1;
 242   return parm;
 243 }
 244
 245 /* Constructors for types with virtual baseclasses need an "in-charge" flag
 246    saying whether this constructor is responsible for initialization of
 247    virtual baseclasses or not.  All destructors also need this "in-charge"
 248    flag, which additionally determines whether or not the destructor should
 249    free the memory for the object.
 250
 251    This function adds the "in-charge" flag to member function FN if
 252    appropriate.  It is called from grokclassfn and tsubst.
 253    FN must be either a constructor or destructor.
 254
 255    The in-charge flag follows the 'this' parameter, and is followed by the
 256    VTT parm (if any), then the user-written parms.  */
 257
 258 void
 259 maybe_retrofit_in_chrg (tree fn)
 260 {
 261   tree basetype, arg_types, parms, parm, fntype;
 262
 263   /* If we've already add the in-charge parameter don't do it again.  */
 264   if (DECL_HAS_IN_CHARGE_PARM_P (fn))
 265     return;
 266
 267   /* When processing templates we can't know, in general, whether or
 268      not we're going to have virtual baseclasses.  */
 269   if (processing_template_decl)
 270     return;
 271
 272   /* We don't need an in-charge parameter for constructors that don't
 273      have virtual bases.  */
 274   if (DECL_CONSTRUCTOR_P (fn)
 275       && !CLASSTYPE_VBASECLASSES (DECL_CONTEXT (fn)))
 276     return;
 277
 278   arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
 279   basetype = TREE_TYPE (TREE_VALUE (arg_types));
 280   arg_types = TREE_CHAIN (arg_types);
 281
 282   parms = DECL_CHAIN (DECL_ARGUMENTS (fn));
 283
 284   /* If this is a subobject constructor or destructor, our caller will
 285      pass us a pointer to our VTT.  */
 286   if (CLASSTYPE_VBASECLASSES (DECL_CONTEXT (fn)))
 287     {
 288       parm = build_artificial_parm (fn, vtt_parm_identifier, vtt_parm_type);
 289
 290       /* First add it to DECL_ARGUMENTS between 'this' and the real args...  */
 291       DECL_CHAIN (parm) = parms;
 292       parms = parm;
 293
 294       /* ...and then to TYPE_ARG_TYPES.  */
 295       arg_types = hash_tree_chain (vtt_parm_type, arg_types);
 296
 297       DECL_HAS_VTT_PARM_P (fn) = 1;
 298     }
 299
 300   /* Then add the in-charge parm (before the VTT parm).  */
 301   parm = build_artificial_parm (fn, in_charge_identifier, integer_type_node);
 302   DECL_CHAIN (parm) = parms;
 303   parms = parm;
 304   arg_types = hash_tree_chain (integer_type_node, arg_types);
 305
 306   /* Insert our new parameter(s) into the list.  */
 307   DECL_CHAIN (DECL_ARGUMENTS (fn)) = parms;
 308
 309   /* And rebuild the function type.  */
 310   fntype = build_method_type_directly (basetype, TREE_TYPE (TREE_TYPE (fn)),
 311                                        arg_types);
 312   if (TYPE_ATTRIBUTES (TREE_TYPE (fn)))
 313     fntype = (cp_build_type_attribute_variant
 314               (fntype, TYPE_ATTRIBUTES (TREE_TYPE (fn))));
 315   fntype = cxx_copy_lang_qualifiers (fntype, TREE_TYPE (fn));
 316   TREE_TYPE (fn) = fntype;
 317
 318   /* Now we've got the in-charge parameter.  */
 319   DECL_HAS_IN_CHARGE_PARM_P (fn) = 1;
 320 }
 321
 322 /* Classes overload their constituent function names automatically.
 323    When a function name is declared in a record structure,
 324    its name is changed to it overloaded name.  Since names for
 325    constructors and destructors can conflict, we place a leading
 326    '$' for destructors.
 327
 328    CNAME is the name of the class we are grokking for.
 329
 330    FUNCTION is a FUNCTION_DECL.  It was created by `grokdeclarator'.
 331
 332    FLAGS contains bits saying what's special about today's
 333    arguments.  DTOR_FLAG == DESTRUCTOR.
 334
 335    If FUNCTION is a destructor, then we must add the `auto-delete' field
 336    as a second parameter.  There is some hair associated with the fact
 337    that we must "declare" this variable in the manner consistent with the
 338    way the rest of the arguments were declared.
 339
 340    QUALS are the qualifiers for the this pointer.  */
 341
 342 void
 343 grokclassfn (tree ctype, tree function, enum overload_flags flags)
 344 {
 345   tree fn_name = DECL_NAME (function);
 346
 347   /* Even within an `extern "C"' block, members get C++ linkage.  See
 348      [dcl.link] for details.  */
 349   SET_DECL_LANGUAGE (function, lang_cplusplus);
 350
 351   if (fn_name == NULL_TREE)
 352     {
 353       error ("name missing for member function");
 354       fn_name = get_identifier ("<anonymous>");
 355       DECL_NAME (function) = fn_name;
 356     }
 357
 358   DECL_CONTEXT (function) = ctype;
 359
 360   if (flags == DTOR_FLAG)
 361     DECL_CXX_DESTRUCTOR_P (function) = 1;
 362
 363   if (flags == DTOR_FLAG || DECL_CONSTRUCTOR_P (function))
 364     maybe_retrofit_in_chrg (function);
 365 }
 366
 367 /* Create an ARRAY_REF, checking for the user doing things backwards
 368    along the way.  DECLTYPE_P is for N3276, as in the parser.  */
 369
 370 tree
 371 grok_array_decl (location_t loc, tree array_expr, tree index_exp,
 372                  bool decltype_p)
 373 {
 374   tree type;
 375   tree expr;
 376   tree orig_array_expr = array_expr;
 377   tree orig_index_exp = index_exp;
 378   tree overload = NULL_TREE;
 379
 380   if (error_operand_p (array_expr) || error_operand_p (index_exp))
 381     return error_mark_node;
 382
 383   if (processing_template_decl)
 384     {
 385       if (type_dependent_expression_p (array_expr)
 386           || type_dependent_expression_p (index_exp))
 387         return build_min_nt_loc (loc, ARRAY_REF, array_expr, index_exp,
 388                                  NULL_TREE, NULL_TREE);
 389       array_expr = build_non_dependent_expr (array_expr);
 390       index_exp = build_non_dependent_expr (index_exp);
 391     }
 392
 393   type = TREE_TYPE (array_expr);
 394   gcc_assert (type);
 395   type = non_reference (type);
 396
 397   /* If they have an `operator[]', use that.  */
 398   if (MAYBE_CLASS_TYPE_P (type) || MAYBE_CLASS_TYPE_P (TREE_TYPE (index_exp)))
 399     {
 400       tsubst_flags_t complain = tf_warning_or_error;
 401       if (decltype_p)
 402         complain |= tf_decltype;
 403       expr = build_new_op (loc, ARRAY_REF, LOOKUP_NORMAL, array_expr,
 404                            index_exp, NULL_TREE, &overload, complain);
 405     }
 406   else
 407     {
 408       tree p1, p2, i1, i2;
 409       bool swapped = false;
 410
 411       /* Otherwise, create an ARRAY_REF for a pointer or array type.
 412          It is a little-known fact that, if `a' is an array and `i' is
 413          an int, you can write `i[a]', which means the same thing as
 414          `a[i]'.  */
 415       if (TREE_CODE (type) == ARRAY_TYPE || VECTOR_TYPE_P (type))
 416         p1 = array_expr;
 417       else
 418         p1 = build_expr_type_conversion (WANT_POINTER, array_expr, false);
 419
 420       if (TREE_CODE (TREE_TYPE (index_exp)) == ARRAY_TYPE)
 421         p2 = index_exp;
 422       else
 423         p2 = build_expr_type_conversion (WANT_POINTER, index_exp, false);
 424
 425       i1 = build_expr_type_conversion (WANT_INT | WANT_ENUM, array_expr,
 426                                        false);
 427       i2 = build_expr_type_conversion (WANT_INT | WANT_ENUM, index_exp,
 428                                        false);
 429
 430       if ((p1 && i2) && (i1 && p2))
 431         error ("ambiguous conversion for array subscript");
 432
 433       if (p1 && i2)
 434         array_expr = p1, index_exp = i2;
 435       else if (i1 && p2)
 436         swapped = true, array_expr = p2, index_exp = i1;
 437       else
 438         {
 439           error_at (loc, "invalid types %<%T[%T]%> for array subscript",
 440                     type, TREE_TYPE (index_exp));
 441           return error_mark_node;
 442         }
 443
 444       if (array_expr == error_mark_node || index_exp == error_mark_node)
 445         error ("ambiguous conversion for array subscript");
 446
 447       if (TYPE_PTR_P (TREE_TYPE (array_expr)))
 448         array_expr = mark_rvalue_use (array_expr);
 449       else
 450         array_expr = mark_lvalue_use_nonread (array_expr);
 451       index_exp = mark_rvalue_use (index_exp);
 452       if (swapped
 453           && flag_strong_eval_order == 2
 454           && (TREE_SIDE_EFFECTS (array_expr) || TREE_SIDE_EFFECTS (index_exp)))
 455         expr = build_array_ref (input_location, index_exp, array_expr);
 456       else
 457         expr = build_array_ref (input_location, array_expr, index_exp);
 458     }
 459   if (processing_template_decl && expr != error_mark_node)
 460     {
 461       if (overload != NULL_TREE)
 462         return (build_min_non_dep_op_overload
 463                 (ARRAY_REF, expr, overload, orig_array_expr, orig_index_exp));
 464
 465       return build_min_non_dep (ARRAY_REF, expr, orig_array_expr, orig_index_exp,
 466                                 NULL_TREE, NULL_TREE);
 467     }
 468   return expr;
 469 }
 470
 471 /* Given the cast expression EXP, checking out its validity.   Either return
 472    an error_mark_node if there was an unavoidable error, return a cast to
 473    void for trying to delete a pointer w/ the value 0, or return the
 474    call to delete.  If DOING_VEC is true, we handle things differently
 475    for doing an array delete.
 476    Implements ARM $5.3.4.  This is called from the parser.  */
 477
 478 tree
 479 delete_sanity (location_t loc, tree exp, tree size, bool doing_vec,
 480                int use_global_delete, tsubst_flags_t complain)
 481 {
 482   tree t, type;
 483
 484   if (exp == error_mark_node)
 485     return exp;
 486
 487   if (processing_template_decl)
 488     {
 489       t = build_min (DELETE_EXPR, void_type_node, exp, size);
 490       DELETE_EXPR_USE_GLOBAL (t) = use_global_delete;
 491       DELETE_EXPR_USE_VEC (t) = doing_vec;
 492       TREE_SIDE_EFFECTS (t) = 1;
 493       SET_EXPR_LOCATION (t, loc);
 494       return t;
 495     }
 496
 497   location_t exp_loc = cp_expr_loc_or_loc (exp, loc);
 498
 499   /* An array can't have been allocated by new, so complain.  */
 500   if (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE
 501       && (complain & tf_warning))
 502     warning_at (exp_loc, 0, "deleting array %q#E", exp);
 503
 504   t = build_expr_type_conversion (WANT_POINTER, exp, true);
 505
 506   if (t == NULL_TREE || t == error_mark_node)
 507     {
 508       if (complain & tf_error)
 509         error_at (exp_loc,
 510                   "type %q#T argument given to %<delete%>, expected pointer",
 511                   TREE_TYPE (exp));
 512       return error_mark_node;
 513     }
 514
 515   type = TREE_TYPE (t);
 516
 517   /* As of Valley Forge, you can delete a pointer to const.  */
 518
 519   /* You can't delete functions.  */
 520   if (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
 521     {
 522       if (complain & tf_error)
 523         error_at (exp_loc,
 524                   "cannot delete a function.  Only pointer-to-objects are "
 525                   "valid arguments to %<delete%>");
 526       return error_mark_node;
 527     }
 528
 529   /* Deleting ptr to void is undefined behavior [expr.delete/3].  */
 530   if (VOID_TYPE_P (TREE_TYPE (type)))
 531     {
 532       if (complain & tf_warning)
 533         warning_at (exp_loc, OPT_Wdelete_incomplete,
 534                     "deleting %qT is undefined", type);
 535       doing_vec = 0;
 536     }
 537
 538   /* Deleting a pointer with the value zero is valid and has no effect.  */
 539   if (integer_zerop (t))
 540     return build1_loc (loc, NOP_EXPR, void_type_node, t);
 541
 542   if (doing_vec)
 543     return build_vec_delete (loc, t, /*maxindex=*/NULL_TREE,
 544                              sfk_deleting_destructor,
 545                              use_global_delete, complain);
 546   else
 547     return build_delete (loc, type, t, sfk_deleting_destructor,
 548                          LOOKUP_NORMAL, use_global_delete,
 549                          complain);
 550 }
 551
 552 /* Report an error if the indicated template declaration is not the
 553    sort of thing that should be a member template.  */
 554
 555 void
 556 check_member_template (tree tmpl)
 557 {
 558   tree decl;
 559
 560   gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
 561   decl = DECL_TEMPLATE_RESULT (tmpl);
 562
 563   if (TREE_CODE (decl) == FUNCTION_DECL
 564       || DECL_ALIAS_TEMPLATE_P (tmpl)
 565       || (TREE_CODE (decl) == TYPE_DECL
 566           && MAYBE_CLASS_TYPE_P (TREE_TYPE (decl))))
 567     {
 568       /* The parser rejects template declarations in local classes
 569          (with the exception of generic lambdas).  */
 570       gcc_assert (!current_function_decl || LAMBDA_FUNCTION_P (decl));
 571       /* The parser rejects any use of virtual in a function template.  */
 572       gcc_assert (!(TREE_CODE (decl) == FUNCTION_DECL
 573                     && DECL_VIRTUAL_P (decl)));
 574
 575       /* The debug-information generating code doesn't know what to do
 576          with member templates.  */
 577       DECL_IGNORED_P (tmpl) = 1;
 578     }
 579   else if (variable_template_p (tmpl))
 580     /* OK */;
 581   else
 582     error ("template declaration of %q#D", decl);
 583 }
 584
 585 /* Sanity check: report error if this function FUNCTION is not
 586    really a member of the class (CTYPE) it is supposed to belong to.
 587    TEMPLATE_PARMS is used to specify the template parameters of a member
 588    template passed as FUNCTION_DECL. If the member template is passed as a
 589    TEMPLATE_DECL, it can be NULL since the parameters can be extracted
 590    from the declaration. If the function is not a function template, it
 591    must be NULL.
 592    It returns the original declaration for the function, NULL_TREE if
 593    no declaration was found, error_mark_node if an error was emitted.  */
 594
 595 tree
 596 check_classfn (tree ctype, tree function, tree template_parms)
 597 {
 598   if (DECL_USE_TEMPLATE (function)
 599       && !(TREE_CODE (function) == TEMPLATE_DECL
 600            && DECL_TEMPLATE_SPECIALIZATION (function))
 601       && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (function)))
 602     /* Since this is a specialization of a member template,
 603        we're not going to find the declaration in the class.
 604        For example, in:
 605
 606          struct S { template <typename T> void f(T); };
 607          template <> void S::f(int);
 608
 609        we're not going to find `S::f(int)', but there's no
 610        reason we should, either.  We let our callers know we didn't
 611        find the method, but we don't complain.  */
 612     return NULL_TREE;
 613
 614   /* Basic sanity check: for a template function, the template parameters
 615      either were not passed, or they are the same of DECL_TEMPLATE_PARMS.  */
 616   if (TREE_CODE (function) == TEMPLATE_DECL)
 617     {
 618       if (template_parms
 619           && !comp_template_parms (template_parms,
 620                                    DECL_TEMPLATE_PARMS (function)))
 621         {
 622           error ("template parameter lists provided don%'t match the "
 623                  "template parameters of %qD", function);
 624           return error_mark_node;
 625         }
 626       template_parms = DECL_TEMPLATE_PARMS (function);
 627     }
 628
 629   /* OK, is this a definition of a member template?  */
 630   bool is_template = (template_parms != NULL_TREE);
 631
 632   /* [temp.mem]
 633
 634      A destructor shall not be a member template.  */
 635   if (DECL_DESTRUCTOR_P (function) && is_template)
 636     {
 637       error ("destructor %qD declared as member template", function);
 638       return error_mark_node;
 639     }
 640
 641   /* We must enter the scope here, because conversion operators are
 642      named by target type, and type equivalence relies on typenames
 643      resolving within the scope of CTYPE.  */
 644   tree pushed_scope = push_scope (ctype);
 645   tree matched = NULL_TREE;
 646   tree fns = get_class_binding (ctype, DECL_NAME (function));
 647
 648   for (ovl_iterator iter (fns); !matched && iter; ++iter)
 649     {
 650       tree fndecl = *iter;
 651
 652       /* A member template definition only matches a member template
 653          declaration.  */
 654       if (is_template != (TREE_CODE (fndecl) == TEMPLATE_DECL))
 655         continue;
 656
 657       if (!DECL_DECLARES_FUNCTION_P (fndecl))
 658         continue;
 659
 660       tree p1 = TYPE_ARG_TYPES (TREE_TYPE (function));
 661       tree p2 = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
 662
 663       /* We cannot simply call decls_match because this doesn't work
 664          for static member functions that are pretending to be
 665          methods, and because the name may have been changed by
 666          asm("new_name").  */
 667
 668       /* Get rid of the this parameter on functions that become
 669          static.  */
 670       if (DECL_STATIC_FUNCTION_P (fndecl)
 671           && TREE_CODE (TREE_TYPE (function)) == METHOD_TYPE)
 672         p1 = TREE_CHAIN (p1);
 673
 674       /* ref-qualifier or absence of same must match.  */
 675       if (type_memfn_rqual (TREE_TYPE (function))
 676           != type_memfn_rqual (TREE_TYPE (fndecl)))
 677         continue;
 678
 679       // Include constraints in the match.
 680       tree c1 = get_constraints (function);
 681       tree c2 = get_constraints (fndecl);
 682
 683       /* While finding a match, same types and params are not enough
 684          if the function is versioned.  Also check version ("target")
 685          attributes.  */
 686       if (same_type_p (TREE_TYPE (TREE_TYPE (function)),
 687                        TREE_TYPE (TREE_TYPE (fndecl)))
 688           && compparms (p1, p2)
 689           && !targetm.target_option.function_versions (function, fndecl)
 690           && (!is_template
 691               || comp_template_parms (template_parms,
 692                                       DECL_TEMPLATE_PARMS (fndecl)))
 693           && equivalent_constraints (c1, c2)
 694           && (DECL_TEMPLATE_SPECIALIZATION (function)
 695               == DECL_TEMPLATE_SPECIALIZATION (fndecl))
 696           && (!DECL_TEMPLATE_SPECIALIZATION (function)
 697               || (DECL_TI_TEMPLATE (function) == DECL_TI_TEMPLATE (fndecl))))
 698         matched = fndecl;
 699     }
 700
 701   if (!matched)
 702     {
 703       if (!COMPLETE_TYPE_P (ctype))
 704         cxx_incomplete_type_error (DECL_SOURCE_LOCATION (function),
 705                                    function, ctype);
 706       else
 707         {
 708           if (DECL_CONV_FN_P (function))
 709             fns = get_class_binding (ctype, conv_op_identifier);
 710
 711           error_at (DECL_SOURCE_LOCATION (function),
 712                     "no declaration matches %q#D", function);
 713           if (fns)
 714             print_candidates (fns);
 715           else if (DECL_CONV_FN_P (function))
 716             inform (DECL_SOURCE_LOCATION (function),
 717                     "no conversion operators declared");
 718           else
 719             inform (DECL_SOURCE_LOCATION (function),
 720                     "no functions named %qD", function);
 721           inform (DECL_SOURCE_LOCATION (TYPE_NAME (ctype)),
 722                   "%#qT defined here", ctype);
 723         }
 724       matched = error_mark_node;
 725     }
 726
 727   if (pushed_scope)
 728     pop_scope (pushed_scope);
 729
 730   return matched;
 731 }
 732
 733 /* DECL is a function with vague linkage.  Remember it so that at the
 734    end of the translation unit we can decide whether or not to emit
 735    it.  */
 736
 737 void
 738 note_vague_linkage_fn (tree decl)
 739 {
 740   if (processing_template_decl)
 741     return;
 742
 743   DECL_DEFER_OUTPUT (decl) = 1;
 744   vec_safe_push (deferred_fns, decl);
 745 }
 746
 747 /* As above, but for variable template instantiations.  */
 748
 749 void
 750 note_variable_template_instantiation (tree decl)
 751 {
 752   vec_safe_push (pending_statics, decl);
 753 }
 754
 755 /* We have just processed the DECL, which is a static data member.
 756    The other parameters are as for cp_finish_decl.  */
 757
 758 void
 759 finish_static_data_member_decl (tree decl,
 760                                 tree init, bool init_const_expr_p,
 761                                 tree asmspec_tree,
 762                                 int flags)
 763 {
 764   if (DECL_TEMPLATE_INSTANTIATED (decl))
 765     /* We already needed to instantiate this, so the processing in this
 766        function is unnecessary/wrong.  */
 767     return;
 768
 769   DECL_CONTEXT (decl) = current_class_type;
 770
 771   /* We cannot call pushdecl here, because that would fill in the
 772      TREE_CHAIN of our decl.  Instead, we modify cp_finish_decl to do
 773      the right thing, namely, to put this decl out straight away.  */
 774
 775   if (! processing_template_decl)
 776     vec_safe_push (pending_statics, decl);
 777
 778   if (LOCAL_CLASS_P (current_class_type)
 779       /* We already complained about the template definition.  */
 780       && !DECL_TEMPLATE_INSTANTIATION (decl))
 781     permerror (DECL_SOURCE_LOCATION (decl),
 782                "local class %q#T shall not have static data member %q#D",
 783                current_class_type, decl);
 784   else
 785     for (tree t = current_class_type; TYPE_P (t);
 786          t = CP_TYPE_CONTEXT (t))
 787       if (TYPE_UNNAMED_P (t))
 788         {
 789           auto_diagnostic_group d;
 790           if (permerror (DECL_SOURCE_LOCATION (decl),
 791                          "static data member %qD in unnamed class", decl))
 792             inform (DECL_SOURCE_LOCATION (TYPE_NAME (t)),
 793                     "unnamed class defined here");
 794           break;
 795         }
 796
 797   if (DECL_INLINE_VAR_P (decl) && !DECL_TEMPLATE_INSTANTIATION (decl))
 798     /* An inline variable is immediately defined, so don't set DECL_IN_AGGR_P.
 799        Except that if decl is a template instantiation, it isn't defined until
 800        instantiate_decl.  */;
 801   else
 802     DECL_IN_AGGR_P (decl) = 1;
 803
 804   if (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
 805       && TYPE_DOMAIN (TREE_TYPE (decl)) == NULL_TREE)
 806     SET_VAR_HAD_UNKNOWN_BOUND (decl);
 807
 808   if (init)
 809     {
 810       /* Similarly to start_decl_1, we want to complete the type in order
 811          to do the right thing in cp_apply_type_quals_to_decl, possibly
 812          clear TYPE_QUAL_CONST (c++/65579).  */
 813       tree type = TREE_TYPE (decl) = complete_type (TREE_TYPE (decl));
 814       cp_apply_type_quals_to_decl (cp_type_quals (type), decl);
 815     }
 816
 817   cp_finish_decl (decl, init, init_const_expr_p, asmspec_tree, flags);
 818 }
 819
 820 /* DECLARATOR and DECLSPECS correspond to a class member.  The other
 821    parameters are as for cp_finish_decl.  Return the DECL for the
 822    class member declared.  */
 823
 824 tree
 825 grokfield (const cp_declarator *declarator,
 826            cp_decl_specifier_seq *declspecs,
 827            tree init, bool init_const_expr_p,
 828            tree asmspec_tree,
 829            tree attrlist)
 830 {
 831   tree value;
 832   const char *asmspec = 0;
 833   int flags;
 834
 835   if (init
 836       && TREE_CODE (init) == TREE_LIST
 837       && TREE_VALUE (init) == error_mark_node
 838       && TREE_CHAIN (init) == NULL_TREE)
 839     init = NULL_TREE;
 840
 841   value = grokdeclarator (declarator, declspecs, FIELD, init != 0, &attrlist);
 842   if (! value || value == error_mark_node)
 843     /* friend or constructor went bad.  */
 844     return error_mark_node;
 845   if (TREE_TYPE (value) == error_mark_node)
 846     return value;
 847
 848   if (TREE_CODE (value) == TYPE_DECL && init)
 849     {
 850       error_at (cp_expr_loc_or_loc (init, DECL_SOURCE_LOCATION (value)),
 851                 "typedef %qD is initialized (use %qs instead)",
 852                 value, "decltype");
 853       init = NULL_TREE;
 854     }
 855
 856   /* Pass friendly classes back.  */
 857   if (value == void_type_node)
 858     return value;
 859
 860   if (DECL_NAME (value)
 861       && TREE_CODE (DECL_NAME (value)) == TEMPLATE_ID_EXPR)
 862     {
 863       error_at (declarator->id_loc,
 864                 "explicit template argument list not allowed");
 865       return error_mark_node;
 866     }
 867
 868   /* Stash away type declarations.  */
 869   if (TREE_CODE (value) == TYPE_DECL)
 870     {
 871       DECL_NONLOCAL (value) = 1;
 872       DECL_CONTEXT (value) = current_class_type;
 873
 874       if (attrlist)
 875         {
 876           int attrflags = 0;
 877
 878           /* If this is a typedef that names the class for linkage purposes
 879              (7.1.3p8), apply any attributes directly to the type.  */
 880           if (OVERLOAD_TYPE_P (TREE_TYPE (value))
 881               && value == TYPE_NAME (TYPE_MAIN_VARIANT (TREE_TYPE (value))))
 882             attrflags = ATTR_FLAG_TYPE_IN_PLACE;
 883
 884           cplus_decl_attributes (&value, attrlist, attrflags);
 885         }
 886
 887       if (decl_spec_seq_has_spec_p (declspecs, ds_typedef)
 888           && TREE_TYPE (value) != error_mark_node
 889           && TYPE_NAME (TYPE_MAIN_VARIANT (TREE_TYPE (value))) != value)
 890         set_underlying_type (value);
 891
 892       /* It's important that push_template_decl below follows
 893          set_underlying_type above so that the created template
 894          carries the properly set type of VALUE.  */
 895       if (processing_template_decl)
 896         value = push_template_decl (value);
 897
 898       record_locally_defined_typedef (value);
 899       return value;
 900     }
 901
 902   int friendp = decl_spec_seq_has_spec_p (declspecs, ds_friend);
 903
 904   if (!friendp && DECL_IN_AGGR_P (value))
 905     {
 906       error ("%qD is already defined in %qT", value, DECL_CONTEXT (value));
 907       return void_type_node;
 908     }
 909
 910   if (asmspec_tree && asmspec_tree != error_mark_node)
 911     asmspec = TREE_STRING_POINTER (asmspec_tree);
 912
 913   if (init)
 914     {
 915       if (TREE_CODE (value) == FUNCTION_DECL)
 916         {
 917           if (init == ridpointers[(int)RID_DELETE])
 918             {
 919               if (friendp && decl_defined_p (value))
 920                 {
 921                   error ("redefinition of %q#D", value);
 922                   inform (DECL_SOURCE_LOCATION (value),
 923                           "%q#D previously defined here", value);
 924                 }
 925               else
 926                 {
 927                   DECL_DELETED_FN (value) = 1;
 928                   DECL_DECLARED_INLINE_P (value) = 1;
 929                   DECL_INITIAL (value) = error_mark_node;
 930                 }
 931             }
 932           else if (init == ridpointers[(int)RID_DEFAULT])
 933             {
 934               if (defaultable_fn_check (value))
 935                 {
 936                   DECL_DEFAULTED_FN (value) = 1;
 937                   DECL_INITIALIZED_IN_CLASS_P (value) = 1;
 938                   DECL_DECLARED_INLINE_P (value) = 1;
 939                 }
 940             }
 941           else if (TREE_CODE (init) == DEFERRED_PARSE)
 942             error ("invalid initializer for member function %qD", value);
 943           else if (TREE_CODE (TREE_TYPE (value)) == METHOD_TYPE)
 944             {
 945               if (integer_zerop (init))
 946                 DECL_PURE_VIRTUAL_P (value) = 1;
 947               else if (error_operand_p (init))
 948                 ; /* An error has already been reported.  */
 949               else
 950                 error ("invalid initializer for member function %qD",
 951                        value);
 952             }
 953           else
 954             {
 955               gcc_assert (TREE_CODE (TREE_TYPE (value)) == FUNCTION_TYPE);
 956               location_t iloc
 957                 = cp_expr_loc_or_loc (init, DECL_SOURCE_LOCATION (value));
 958               if (friendp)
 959                 error_at (iloc, "initializer specified for friend "
 960                           "function %qD", value);
 961               else
 962                 error_at (iloc, "initializer specified for static "
 963                           "member function %qD", value);
 964             }
 965         }
 966       else if (TREE_CODE (value) == FIELD_DECL)
 967         /* C++11 NSDMI, keep going.  */;
 968       else if (!VAR_P (value))
 969         gcc_unreachable ();
 970     }
 971
 972   /* Pass friend decls back.  */
 973   if ((TREE_CODE (value) == FUNCTION_DECL
 974        || TREE_CODE (value) == TEMPLATE_DECL)
 975       && DECL_CONTEXT (value) != current_class_type)
 976     return value;
 977
 978   /* Need to set this before push_template_decl.  */
 979   if (VAR_P (value))
 980     DECL_CONTEXT (value) = current_class_type;
 981
 982   if (processing_template_decl && VAR_OR_FUNCTION_DECL_P (value))
 983     {
 984       value = push_template_decl (value);
 985       if (error_operand_p (value))
 986         return error_mark_node;
 987     }
 988
 989   if (attrlist)
 990     cplus_decl_attributes (&value, attrlist, 0);
 991
 992   if (init && DIRECT_LIST_INIT_P (init))
 993     flags = LOOKUP_NORMAL;
 994   else
 995     flags = LOOKUP_IMPLICIT;
 996
 997   if (decl_spec_seq_has_spec_p (declspecs, ds_constinit))
 998     flags |= LOOKUP_CONSTINIT;
 999
1000   switch (TREE_CODE (value))
1001     {
1002     case VAR_DECL:
1003       finish_static_data_member_decl (value, init, init_const_expr_p,
1004                                       asmspec_tree, flags);
1005       return value;
1006
1007     case FIELD_DECL:
1008       if (asmspec)
1009         error ("%<asm%> specifiers are not permitted on non-static data members");
1010       if (DECL_INITIAL (value) == error_mark_node)
1011         init = error_mark_node;
1012       cp_finish_decl (value, init, /*init_const_expr_p=*/false,
1013                       NULL_TREE, flags);
1014       DECL_IN_AGGR_P (value) = 1;
1015       return value;
1016
1017     case  FUNCTION_DECL:
1018       if (asmspec)
1019         set_user_assembler_name (value, asmspec);
1020
1021       cp_finish_decl (value,
1022                       /*init=*/NULL_TREE,
1023                       /*init_const_expr_p=*/false,
1024                       asmspec_tree, flags);
1025
1026       /* Pass friends back this way.  */
1027       if (DECL_FRIEND_P (value))
1028         return void_type_node;
1029
1030       DECL_IN_AGGR_P (value) = 1;
1031       return value;
1032
1033     default:
1034       gcc_unreachable ();
1035     }
1036   return NULL_TREE;
1037 }
1038
1039 /* Like `grokfield', but for bitfields.
1040    WIDTH is the width of the bitfield, a constant expression.
1041    The other parameters are as for grokfield.  */
1042
1043 tree
1044 grokbitfield (const cp_declarator *declarator,
1045               cp_decl_specifier_seq *declspecs, tree width, tree init,
1046               tree attrlist)
1047 {
1048   tree value = grokdeclarator (declarator, declspecs, BITFIELD,
1049                                init != NULL_TREE, &attrlist);
1050
1051   if (value == error_mark_node)
1052     return NULL_TREE; /* friends went bad.  */
1053
1054   tree type = TREE_TYPE (value);
1055   if (type == error_mark_node)
1056     return value;
1057
1058   /* Pass friendly classes back.  */
1059   if (VOID_TYPE_P (value))
1060     return void_type_node;
1061
1062   if (!INTEGRAL_OR_ENUMERATION_TYPE_P (type)
1063       && (INDIRECT_TYPE_P (type) || !dependent_type_p (type)))
1064     {
1065       error_at (DECL_SOURCE_LOCATION (value),
1066                 "bit-field %qD with non-integral type %qT",
1067                 value, type);
1068       return error_mark_node;
1069     }
1070
1071   if (TREE_CODE (value) == TYPE_DECL)
1072     {
1073       error_at (DECL_SOURCE_LOCATION (value),
1074                 "cannot declare %qD to be a bit-field type", value);
1075       return NULL_TREE;
1076     }
1077
1078   /* Usually, finish_struct_1 catches bitfields with invalid types.
1079      But, in the case of bitfields with function type, we confuse
1080      ourselves into thinking they are member functions, so we must
1081      check here.  */
1082   if (TREE_CODE (value) == FUNCTION_DECL)
1083     {
1084       error_at (DECL_SOURCE_LOCATION (value),
1085                 "cannot declare bit-field %qD with function type", value);
1086       return NULL_TREE;
1087     }
1088
1089   if (TYPE_WARN_IF_NOT_ALIGN (type))
1090     {
1091       error_at (DECL_SOURCE_LOCATION (value), "cannot declare bit-field "
1092                 "%qD with %<warn_if_not_aligned%> type", value);
1093       return NULL_TREE;
1094     }
1095
1096   if (DECL_IN_AGGR_P (value))
1097     {
1098       error ("%qD is already defined in the class %qT", value,
1099              DECL_CONTEXT (value));
1100       return void_type_node;
1101     }
1102
1103   if (TREE_STATIC (value))
1104     {
1105       error_at (DECL_SOURCE_LOCATION (value),
1106                 "static member %qD cannot be a bit-field", value);
1107       return NULL_TREE;
1108     }
1109
1110   int flags = LOOKUP_IMPLICIT;
1111   if (init && DIRECT_LIST_INIT_P (init))
1112     flags = LOOKUP_NORMAL;
1113   cp_finish_decl (value, init, false, NULL_TREE, flags);
1114
1115   if (width != error_mark_node)
1116     {
1117       /* The width must be an integer type.  */
1118       if (!type_dependent_expression_p (width)
1119           && !INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (TREE_TYPE (width)))
1120         error ("width of bit-field %qD has non-integral type %qT", value,
1121                TREE_TYPE (width));
1122       else
1123         {
1124           /* Temporarily stash the width in DECL_BIT_FIELD_REPRESENTATIVE.
1125              check_bitfield_decl picks it from there later and sets DECL_SIZE
1126              accordingly.  */
1127           DECL_BIT_FIELD_REPRESENTATIVE (value) = width;
1128           SET_DECL_C_BIT_FIELD (value);
1129         }
1130     }
1131
1132   DECL_IN_AGGR_P (value) = 1;
1133
1134   if (attrlist)
1135     cplus_decl_attributes (&value, attrlist, /*flags=*/0);
1136
1137   return value;
1138 }
1139
1140 \f
1141 /* Returns true iff ATTR is an attribute which needs to be applied at
1142    instantiation time rather than template definition time.  */
1143
1144 static bool
1145 is_late_template_attribute (tree attr, tree decl)
1146 {
1147   tree name = get_attribute_name (attr);
1148   tree args = TREE_VALUE (attr);
1149   const struct attribute_spec *spec = lookup_attribute_spec (name);
1150   tree arg;
1151
1152   if (!spec)
1153     /* Unknown attribute.  */
1154     return false;
1155
1156   /* Attribute weak handling wants to write out assembly right away.  */
1157   if (is_attribute_p ("weak", name))
1158     return true;
1159
1160   /* Attributes used and unused are applied directly to typedefs for the
1161      benefit of maybe_warn_unused_local_typedefs.  */
1162   if (TREE_CODE (decl) == TYPE_DECL
1163       && (is_attribute_p ("unused", name)
1164           || is_attribute_p ("used", name)))
1165     return false;
1166
1167   /* Attribute tls_model wants to modify the symtab.  */
1168   if (is_attribute_p ("tls_model", name))
1169     return true;
1170
1171   /* #pragma omp declare simd attribute needs to be always deferred.  */
1172   if (flag_openmp
1173       && is_attribute_p ("omp declare simd", name))
1174     return true;
1175
1176   /* An attribute pack is clearly dependent.  */
1177   if (args && PACK_EXPANSION_P (args))
1178     return true;
1179
1180   /* If any of the arguments are dependent expressions, we can't evaluate
1181      the attribute until instantiation time.  */
1182   for (arg = args; arg; arg = TREE_CHAIN (arg))
1183     {
1184       tree t = TREE_VALUE (arg);
1185
1186       /* If the first attribute argument is an identifier, only consider
1187          second and following arguments.  Attributes like mode, format,
1188          cleanup and several target specific attributes aren't late
1189          just because they have an IDENTIFIER_NODE as first argument.  */
1190       if (arg == args && attribute_takes_identifier_p (name)
1191           && identifier_p (t))
1192         continue;
1193
1194       if (value_dependent_expression_p (t)
1195           || type_dependent_expression_p (t))
1196         return true;
1197     }
1198
1199   if (TREE_CODE (decl) == TYPE_DECL
1200       || TYPE_P (decl)
1201       || spec->type_required)
1202     {
1203       tree type = TYPE_P (decl) ? decl : TREE_TYPE (decl);
1204
1205       /* We can't apply any attributes to a completely unknown type until
1206          instantiation time.  */
1207       enum tree_code code = TREE_CODE (type);
1208       if (code == TEMPLATE_TYPE_PARM
1209           || code == BOUND_TEMPLATE_TEMPLATE_PARM
1210           || code == TYPENAME_TYPE)
1211         return true;
1212       /* Also defer most attributes on dependent types.  This is not
1213          necessary in all cases, but is the better default.  */
1214       else if (dependent_type_p (type)
1215                /* But some attributes specifically apply to templates.  */
1216                && !is_attribute_p ("abi_tag", name)
1217                && !is_attribute_p ("deprecated", name)
1218                && !is_attribute_p ("visibility", name))
1219         return true;
1220       else
1221         return false;
1222     }
1223   else
1224     return false;
1225 }
1226
1227 /* ATTR_P is a list of attributes.  Remove any attributes which need to be
1228    applied at instantiation time and return them.  If IS_DEPENDENT is true,
1229    the declaration itself is dependent, so all attributes should be applied
1230    at instantiation time.  */
1231
1232 static tree
1233 splice_template_attributes (tree *attr_p, tree decl)
1234 {
1235   tree *p = attr_p;
1236   tree late_attrs = NULL_TREE;
1237   tree *q = &late_attrs;
1238
1239   if (!p)
1240     return NULL_TREE;
1241
1242   for (; *p; )
1243     {
1244       if (is_late_template_attribute (*p, decl))
1245         {
1246           ATTR_IS_DEPENDENT (*p) = 1;
1247           *q = *p;
1248           *p = TREE_CHAIN (*p);
1249           q = &TREE_CHAIN (*q);
1250           *q = NULL_TREE;
1251         }
1252       else
1253         p = &TREE_CHAIN (*p);
1254     }
1255
1256   return late_attrs;
1257 }
1258
1259 /* Remove any late attributes from the list in ATTR_P and attach them to
1260    DECL_P.  */
1261
1262 static void
1263 save_template_attributes (tree *attr_p, tree *decl_p, int flags)
1264 {
1265   tree *q;
1266
1267   if (attr_p && *attr_p == error_mark_node)
1268     return;
1269
1270   tree late_attrs = splice_template_attributes (attr_p, *decl_p);
1271   if (!late_attrs)
1272     return;
1273
1274   if (DECL_P (*decl_p))
1275     q = &DECL_ATTRIBUTES (*decl_p);
1276   else
1277     q = &TYPE_ATTRIBUTES (*decl_p);
1278
1279   tree old_attrs = *q;
1280
1281   /* Merge the late attributes at the beginning with the attribute
1282      list.  */
1283   late_attrs = merge_attributes (late_attrs, *q);
1284   if (*q != late_attrs
1285       && !DECL_P (*decl_p)
1286       && !(flags & ATTR_FLAG_TYPE_IN_PLACE))
1287     {
1288       if (!dependent_type_p (*decl_p))
1289         *decl_p = cp_build_type_attribute_variant (*decl_p, late_attrs);
1290       else
1291         {
1292           *decl_p = build_variant_type_copy (*decl_p);
1293           TYPE_ATTRIBUTES (*decl_p) = late_attrs;
1294         }
1295     }
1296   else
1297     *q = late_attrs;
1298
1299   if (!DECL_P (*decl_p) && *decl_p == TYPE_MAIN_VARIANT (*decl_p))
1300     {
1301       /* We've added new attributes directly to the main variant, so
1302          now we need to update all of the other variants to include
1303          these new attributes.  */
1304       tree variant;
1305       for (variant = TYPE_NEXT_VARIANT (*decl_p); variant;
1306            variant = TYPE_NEXT_VARIANT (variant))
1307         {
1308           gcc_assert (TYPE_ATTRIBUTES (variant) == old_attrs);
1309           TYPE_ATTRIBUTES (variant) = TYPE_ATTRIBUTES (*decl_p);
1310         }
1311     }
1312 }
1313
1314 /* True if ATTRS contains any dependent attributes that affect type
1315    identity.  */
1316
1317 bool
1318 any_dependent_type_attributes_p (tree attrs)
1319 {
1320   for (tree a = attrs; a; a = TREE_CHAIN (a))
1321     if (ATTR_IS_DEPENDENT (a))
1322       {
1323         const attribute_spec *as = lookup_attribute_spec (TREE_PURPOSE (a));
1324         if (as && as->affects_type_identity)
1325           return true;
1326       }
1327   return false;
1328 }
1329
1330 /* Return true iff ATTRS are acceptable attributes to be applied in-place
1331    to a typedef which gives a previously unnamed class or enum a name for
1332    linkage purposes.  */
1333
1334 bool
1335 attributes_naming_typedef_ok (tree attrs)
1336 {
1337   for (; attrs; attrs = TREE_CHAIN (attrs))
1338     {
1339       tree name = get_attribute_name (attrs);
1340       if (is_attribute_p ("vector_size", name))
1341         return false;
1342     }
1343   return true;
1344 }
1345
1346 /* Like reconstruct_complex_type, but handle also template trees.  */
1347
1348 tree
1349 cp_reconstruct_complex_type (tree type, tree bottom)
1350 {
1351   tree inner, outer;
1352
1353   if (TYPE_PTR_P (type))
1354     {
1355       inner = cp_reconstruct_complex_type (TREE_TYPE (type), bottom);
1356       outer = build_pointer_type_for_mode (inner, TYPE_MODE (type),
1357                                            TYPE_REF_CAN_ALIAS_ALL (type));
1358     }
1359   else if (TYPE_REF_P (type))
1360     {
1361       inner = cp_reconstruct_complex_type (TREE_TYPE (type), bottom);
1362       outer = build_reference_type_for_mode (inner, TYPE_MODE (type),
1363                                              TYPE_REF_CAN_ALIAS_ALL (type));
1364     }
1365   else if (TREE_CODE (type) == ARRAY_TYPE)
1366     {
1367       inner = cp_reconstruct_complex_type (TREE_TYPE (type), bottom);
1368       outer = build_cplus_array_type (inner, TYPE_DOMAIN (type));
1369       /* Don't call cp_build_qualified_type on ARRAY_TYPEs, the
1370          element type qualification will be handled by the recursive
1371          cp_reconstruct_complex_type call and cp_build_qualified_type
1372          for ARRAY_TYPEs changes the element type.  */
1373       return outer;
1374     }
1375   else if (TREE_CODE (type) == FUNCTION_TYPE)
1376     {
1377       inner = cp_reconstruct_complex_type (TREE_TYPE (type), bottom);
1378       outer = build_function_type (inner, TYPE_ARG_TYPES (type));
1379       outer = apply_memfn_quals (outer, type_memfn_quals (type));
1380     }
1381   else if (TREE_CODE (type) == METHOD_TYPE)
1382     {
1383       inner = cp_reconstruct_complex_type (TREE_TYPE (type), bottom);
1384       /* The build_method_type_directly() routine prepends 'this' to argument list,
1385          so we must compensate by getting rid of it.  */
1386       outer
1387         = build_method_type_directly
1388             (class_of_this_parm (type), inner,
1389              TREE_CHAIN (TYPE_ARG_TYPES (type)));
1390     }
1391   else if (TREE_CODE (type) == OFFSET_TYPE)
1392     {
1393       inner = cp_reconstruct_complex_type (TREE_TYPE (type), bottom);
1394       outer = build_offset_type (TYPE_OFFSET_BASETYPE (type), inner);
1395     }
1396   else
1397     return bottom;
1398
1399   if (TYPE_ATTRIBUTES (type))
1400     outer = cp_build_type_attribute_variant (outer, TYPE_ATTRIBUTES (type));
1401   outer = cp_build_qualified_type (outer, cp_type_quals (type));
1402   outer = cxx_copy_lang_qualifiers (outer, type);
1403
1404   return outer;
1405 }
1406
1407 /* Replaces any constexpr expression that may be into the attributes
1408    arguments with their reduced value.  */
1409
1410 void
1411 cp_check_const_attributes (tree attributes)
1412 {
1413   if (attributes == error_mark_node)
1414     return;
1415
1416   tree attr;
1417   for (attr = attributes; attr; attr = TREE_CHAIN (attr))
1418     {
1419       tree arg;
1420       for (arg = TREE_VALUE (attr); arg && TREE_CODE (arg) == TREE_LIST;
1421            arg = TREE_CHAIN (arg))
1422         {
1423           tree expr = TREE_VALUE (arg);
1424           if (EXPR_P (expr))
1425             TREE_VALUE (arg) = fold_non_dependent_expr (expr);
1426         }
1427     }
1428 }
1429
1430 /* Return true if TYPE is an OpenMP mappable type.
1431    If NOTES is non-zero, emit a note message for each problem.  */
1432 static bool
1433 cp_omp_mappable_type_1 (tree type, bool notes)
1434 {
1435   bool result = true;
1436
1437   /* Mappable type has to be complete.  */
1438   if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1439     {
1440       if (notes && type != error_mark_node)
1441         {
1442           tree decl = TYPE_MAIN_DECL (type);
1443           inform ((decl ? DECL_SOURCE_LOCATION (decl) : input_location),
1444                   "incomplete type %qT is not mappable", type);
1445         }
1446       result = false;
1447     }
1448   /* Arrays have mappable type if the elements have mappable type.  */
1449   while (TREE_CODE (type) == ARRAY_TYPE)
1450     type = TREE_TYPE (type);
1451   /* A mappable type cannot contain virtual members.  */
1452   if (CLASS_TYPE_P (type) && CLASSTYPE_VTABLES (type))
1453     {
1454       if (notes)
1455         inform (DECL_SOURCE_LOCATION (TYPE_MAIN_DECL (type)),
1456                 "type %qT with virtual members is not mappable", type);
1457       result = false;
1458     }
1459   /* All data members must be non-static.  */
1460   if (CLASS_TYPE_P (type))
1461     {
1462       tree field;
1463       for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
1464         if (VAR_P (field))
1465           {
1466             if (notes)
1467               inform (DECL_SOURCE_LOCATION (field),
1468                       "static field %qD is not mappable", field);
1469             result = false;
1470           }
1471         /* All fields must have mappable types.  */
1472         else if (TREE_CODE (field) == FIELD_DECL
1473                  && !cp_omp_mappable_type_1 (TREE_TYPE (field), notes))
1474           result = false;
1475     }
1476   return result;
1477 }
1478
1479 /* Return true if TYPE is an OpenMP mappable type.  */
1480 bool
1481 cp_omp_mappable_type (tree type)
1482 {
1483   return cp_omp_mappable_type_1 (type, false);
1484 }
1485
1486 /* Return true if TYPE is an OpenMP mappable type.
1487    Emit an error messages if not.  */
1488 bool
1489 cp_omp_emit_unmappable_type_notes (tree type)
1490 {
1491   return cp_omp_mappable_type_1 (type, true);
1492 }
1493
1494 /* Return the last pushed declaration for the symbol DECL or NULL
1495    when no such declaration exists.  */
1496
1497 static tree
1498 find_last_decl (tree decl)
1499 {
1500   tree last_decl = NULL_TREE;
1501
1502   if (tree name = DECL_P (decl) ? DECL_NAME (decl) : NULL_TREE)
1503     {
1504       /* Look up the declaration in its scope.  */
1505       tree pushed_scope = NULL_TREE;
1506       if (tree ctype = DECL_CONTEXT (decl))
1507         pushed_scope = push_scope (ctype);
1508
1509       last_decl = lookup_name (name);
1510
1511       if (pushed_scope)
1512         pop_scope (pushed_scope);
1513
1514       /* The declaration may be a member conversion operator
1515          or a bunch of overfloads (handle the latter below).  */
1516       if (last_decl && BASELINK_P (last_decl))
1517         last_decl = BASELINK_FUNCTIONS (last_decl);
1518     }
1519
1520   if (!last_decl)
1521     return NULL_TREE;
1522
1523   if (DECL_P (last_decl) || TREE_CODE (last_decl) == OVERLOAD)
1524     {
1525       /* A set of overloads of the same function.  */
1526       for (lkp_iterator iter (last_decl); iter; ++iter)
1527         {
1528           if (TREE_CODE (*iter) == OVERLOAD)
1529             continue;
1530
1531           if (decls_match (decl, *iter, /*record_decls=*/false))
1532             return *iter;
1533         }
1534       return NULL_TREE;
1535     }
1536
1537   return NULL_TREE;
1538 }
1539
1540 /* Like decl_attributes, but handle C++ complexity.  */
1541
1542 void
1543 cplus_decl_attributes (tree *decl, tree attributes, int flags)
1544 {
1545   if (*decl == NULL_TREE || *decl == void_type_node
1546       || *decl == error_mark_node)
1547     return;
1548
1549   /* Add implicit "omp declare target" attribute if requested.  */
1550   if (scope_chain->omp_declare_target_attribute
1551       && ((VAR_P (*decl)
1552            && (TREE_STATIC (*decl) || DECL_EXTERNAL (*decl)))
1553           || TREE_CODE (*decl) == FUNCTION_DECL))
1554     {
1555       if (VAR_P (*decl)
1556           && DECL_CLASS_SCOPE_P (*decl))
1557         error ("%q+D static data member inside of declare target directive",
1558                *decl);
1559       else if (VAR_P (*decl)
1560                && (processing_template_decl
1561                    || !cp_omp_mappable_type (TREE_TYPE (*decl))))
1562         attributes = tree_cons (get_identifier ("omp declare target implicit"),
1563                                 NULL_TREE, attributes);
1564       else
1565         {
1566           attributes = tree_cons (get_identifier ("omp declare target"),
1567                                   NULL_TREE, attributes);
1568           attributes = tree_cons (get_identifier ("omp declare target block"),
1569                                   NULL_TREE, attributes);
1570         }
1571     }
1572
1573   if (processing_template_decl)
1574     {
1575       if (check_for_bare_parameter_packs (attributes))
1576         return;
1577
1578       save_template_attributes (&attributes, decl, flags);
1579     }
1580
1581   cp_check_const_attributes (attributes);
1582
1583   if (TREE_CODE (*decl) == TEMPLATE_DECL)
1584     decl = &DECL_TEMPLATE_RESULT (*decl);
1585
1586   if (TREE_TYPE (*decl) && TYPE_PTRMEMFUNC_P (TREE_TYPE (*decl)))
1587     {
1588       attributes
1589         = decl_attributes (decl, attributes, flags | ATTR_FLAG_FUNCTION_NEXT);
1590       decl_attributes (&TYPE_PTRMEMFUNC_FN_TYPE_RAW (TREE_TYPE (*decl)),
1591                        attributes, flags);
1592     }
1593   else
1594     {
1595       tree last_decl = find_last_decl (*decl);
1596       decl_attributes (decl, attributes, flags, last_decl);
1597     }
1598
1599   if (TREE_CODE (*decl) == TYPE_DECL)
1600     SET_IDENTIFIER_TYPE_VALUE (DECL_NAME (*decl), TREE_TYPE (*decl));
1601
1602   /* Propagate deprecation out to the template.  */
1603   if (TREE_DEPRECATED (*decl))
1604     if (tree ti = get_template_info (*decl))
1605       {
1606         tree tmpl = TI_TEMPLATE (ti);
1607         tree pattern = (TYPE_P (*decl) ? TREE_TYPE (tmpl)
1608                         : DECL_TEMPLATE_RESULT (tmpl));
1609         if (*decl == pattern)
1610           TREE_DEPRECATED (tmpl) = true;
1611       }
1612 }
1613 \f
1614 /* Walks through the namespace- or function-scope anonymous union
1615    OBJECT, with the indicated TYPE, building appropriate VAR_DECLs.
1616    Returns one of the fields for use in the mangled name.  */
1617
1618 static tree
1619 build_anon_union_vars (tree type, tree object)
1620 {
1621   tree main_decl = NULL_TREE;
1622   tree field;
1623
1624   /* Rather than write the code to handle the non-union case,
1625      just give an error.  */
1626   if (TREE_CODE (type) != UNION_TYPE)
1627     {
1628       error_at (DECL_SOURCE_LOCATION (TYPE_MAIN_DECL (type)),
1629                 "anonymous struct not inside named type");
1630       return error_mark_node;
1631     }
1632
1633   for (field = TYPE_FIELDS (type);
1634        field != NULL_TREE;
1635        field = DECL_CHAIN (field))
1636     {
1637       tree decl;
1638       tree ref;
1639
1640       if (DECL_ARTIFICIAL (field))
1641         continue;
1642       if (TREE_CODE (field) != FIELD_DECL)
1643         {
1644           permerror (DECL_SOURCE_LOCATION (field),
1645                      "%q#D invalid; an anonymous union can only "
1646                      "have non-static data members", field);
1647           continue;
1648         }
1649
1650       if (TREE_PRIVATE (field))
1651         permerror (DECL_SOURCE_LOCATION (field),
1652                    "private member %q#D in anonymous union", field);
1653       else if (TREE_PROTECTED (field))
1654         permerror (DECL_SOURCE_LOCATION (field),
1655                    "protected member %q#D in anonymous union", field);
1656
1657       if (processing_template_decl)
1658         ref = build_min_nt_loc (UNKNOWN_LOCATION, COMPONENT_REF, object,
1659                                 DECL_NAME (field), NULL_TREE);
1660       else
1661         ref = build_class_member_access_expr (object, field, NULL_TREE,
1662                                               false, tf_warning_or_error);
1663
1664       if (DECL_NAME (field))
1665         {
1666           tree base;
1667
1668           decl = build_decl (input_location,
1669                              VAR_DECL, DECL_NAME (field), TREE_TYPE (field));
1670           DECL_ANON_UNION_VAR_P (decl) = 1;
1671           DECL_ARTIFICIAL (decl) = 1;
1672
1673           base = get_base_address (object);
1674           TREE_PUBLIC (decl) = TREE_PUBLIC (base);
1675           TREE_STATIC (decl) = TREE_STATIC (base);
1676           DECL_EXTERNAL (decl) = DECL_EXTERNAL (base);
1677
1678           SET_DECL_VALUE_EXPR (decl, ref);
1679           DECL_HAS_VALUE_EXPR_P (decl) = 1;
1680
1681           decl = pushdecl (decl);
1682         }
1683       else if (ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1684         decl = build_anon_union_vars (TREE_TYPE (field), ref);
1685       else
1686         decl = 0;
1687
1688       if (main_decl == NULL_TREE)
1689         main_decl = decl;
1690     }
1691
1692   return main_decl;
1693 }
1694
1695 /* Finish off the processing of a UNION_TYPE structure.  If the union is an
1696    anonymous union, then all members must be laid out together.  PUBLIC_P
1697    is nonzero if this union is not declared static.  */
1698
1699 void
1700 finish_anon_union (tree anon_union_decl)
1701 {
1702   tree type;
1703   tree main_decl;
1704   bool public_p;
1705
1706   if (anon_union_decl == error_mark_node)
1707     return;
1708
1709   type = TREE_TYPE (anon_union_decl);
1710   public_p = TREE_PUBLIC (anon_union_decl);
1711
1712   /* The VAR_DECL's context is the same as the TYPE's context.  */
1713   DECL_CONTEXT (anon_union_decl) = DECL_CONTEXT (TYPE_NAME (type));
1714
1715   if (TYPE_FIELDS (type) == NULL_TREE)
1716     return;
1717
1718   if (public_p)
1719     {
1720       error ("namespace-scope anonymous aggregates must be static");
1721       return;
1722     }
1723
1724   main_decl = build_anon_union_vars (type, anon_union_decl);
1725   if (main_decl == error_mark_node)
1726     return;
1727   if (main_decl == NULL_TREE)
1728     {
1729       pedwarn (input_location, 0, "anonymous union with no members");
1730       return;
1731     }
1732
1733   if (!processing_template_decl)
1734     {
1735       /* Use main_decl to set the mangled name.  */
1736       DECL_NAME (anon_union_decl) = DECL_NAME (main_decl);
1737       maybe_commonize_var (anon_union_decl);
1738       if (TREE_STATIC (anon_union_decl) || DECL_EXTERNAL (anon_union_decl))
1739         {
1740           if (DECL_DISCRIMINATOR_P (anon_union_decl))
1741             determine_local_discriminator (anon_union_decl);
1742           mangle_decl (anon_union_decl);
1743         }
1744       DECL_NAME (anon_union_decl) = NULL_TREE;
1745     }
1746
1747   pushdecl (anon_union_decl);
1748   cp_finish_decl (anon_union_decl, NULL_TREE, false, NULL_TREE, 0);
1749 }
1750 \f
1751 /* Auxiliary functions to make type signatures for
1752    `operator new' and `operator delete' correspond to
1753    what compiler will be expecting.  */
1754
1755 tree
1756 coerce_new_type (tree type, location_t loc)
1757 {
1758   int e = 0;
1759   tree args = TYPE_ARG_TYPES (type);
1760
1761   gcc_assert (TREE_CODE (type) == FUNCTION_TYPE);
1762
1763   if (!same_type_p (TREE_TYPE (type), ptr_type_node))
1764     {
1765       e = 1;
1766       error_at (loc, "%<operator new%> must return type %qT",
1767                 ptr_type_node);
1768     }
1769
1770   if (args && args != void_list_node)
1771     {
1772       if (TREE_PURPOSE (args))
1773         {
1774           /* [basic.stc.dynamic.allocation]
1775
1776              The first parameter shall not have an associated default
1777              argument.  */
1778           error_at (loc, "the first parameter of %<operator new%> cannot "
1779                     "have a default argument");
1780           /* Throw away the default argument.  */
1781           TREE_PURPOSE (args) = NULL_TREE;
1782         }
1783
1784       if (!same_type_p (TREE_VALUE (args), size_type_node))
1785         {
1786           e = 2;
1787           args = TREE_CHAIN (args);
1788         }
1789     }
1790   else
1791     e = 2;
1792
1793   if (e == 2)
1794     permerror (loc, "%<operator new%> takes type %<size_t%> (%qT) "
1795                "as first parameter", size_type_node);
1796
1797   switch (e)
1798   {
1799     case 2:
1800       args = tree_cons (NULL_TREE, size_type_node, args);
1801       /* Fall through.  */
1802     case 1:
1803       type = (cxx_copy_lang_qualifiers
1804               (build_function_type (ptr_type_node, args),
1805                type));
1806       /* Fall through.  */
1807     default:;
1808   }
1809   return type;
1810 }
1811
1812 void
1813 coerce_delete_type (tree decl, location_t loc)
1814 {
1815   int e = 0;
1816   tree type = TREE_TYPE (decl);
1817   tree args = TYPE_ARG_TYPES (type);
1818
1819   gcc_assert (TREE_CODE (type) == FUNCTION_TYPE);
1820
1821   if (!same_type_p (TREE_TYPE (type), void_type_node))
1822     {
1823       e = 1;
1824       error_at (loc, "%<operator delete%> must return type %qT",
1825                 void_type_node);
1826     }
1827
1828   tree ptrtype = ptr_type_node;
1829   if (destroying_delete_p (decl))
1830     {
1831       if (DECL_CLASS_SCOPE_P (decl))
1832         /* If the function is a destroying operator delete declared in class
1833            type C, the type of its first parameter shall be C*.  */
1834         ptrtype = build_pointer_type (DECL_CONTEXT (decl));
1835       else
1836         /* A destroying operator delete shall be a class member function named
1837            operator delete.  */
1838         error_at (loc,
1839                   "destroying %<operator delete%> must be a member function");
1840       const ovl_op_info_t *op = IDENTIFIER_OVL_OP_INFO (DECL_NAME (decl));
1841       if (op->flags & OVL_OP_FLAG_VEC)
1842         error_at (loc, "%<operator delete[]%> cannot be a destroying delete");
1843       if (!usual_deallocation_fn_p (decl))
1844         error_at (loc, "destroying %<operator delete%> must be a usual "
1845                   "deallocation function");
1846     }
1847
1848   if (!args || args == void_list_node
1849       || !same_type_p (TREE_VALUE (args), ptrtype))
1850     {
1851       e = 2;
1852       if (args && args != void_list_node)
1853         args = TREE_CHAIN (args);
1854       error_at (loc, "%<operator delete%> takes type %qT as first parameter",
1855                 ptrtype);
1856     }
1857   switch (e)
1858   {
1859     case 2:
1860       args = tree_cons (NULL_TREE, ptrtype, args);
1861       /* Fall through.  */
1862     case 1:
1863       type = (cxx_copy_lang_qualifiers
1864               (build_function_type (void_type_node, args),
1865                type));
1866       /* Fall through.  */
1867     default:;
1868   }
1869
1870   TREE_TYPE (decl) = type;
1871 }
1872 \f
1873 /* DECL is a VAR_DECL for a vtable: walk through the entries in the vtable
1874    and mark them as needed.  */
1875
1876 static void
1877 mark_vtable_entries (tree decl)
1878 {
1879   tree fnaddr;
1880   unsigned HOST_WIDE_INT idx;
1881
1882   /* It's OK for the vtable to refer to deprecated virtual functions.  */
1883   warning_sentinel w(warn_deprecated_decl);
1884
1885   FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (DECL_INITIAL (decl)),
1886                               idx, fnaddr)
1887     {
1888       tree fn;
1889
1890       STRIP_NOPS (fnaddr);
1891
1892       if (TREE_CODE (fnaddr) != ADDR_EXPR
1893           && TREE_CODE (fnaddr) != FDESC_EXPR)
1894         /* This entry is an offset: a virtual base class offset, a
1895            virtual call offset, an RTTI offset, etc.  */
1896         continue;
1897
1898       fn = TREE_OPERAND (fnaddr, 0);
1899       TREE_ADDRESSABLE (fn) = 1;
1900       /* When we don't have vcall offsets, we output thunks whenever
1901          we output the vtables that contain them.  With vcall offsets,
1902          we know all the thunks we'll need when we emit a virtual
1903          function, so we emit the thunks there instead.  */
1904       if (DECL_THUNK_P (fn))
1905         use_thunk (fn, /*emit_p=*/0);
1906       /* Set the location, as marking the function could cause
1907          instantiation.  We do not need to preserve the incoming
1908          location, as we're called from c_parse_final_cleanups, which
1909          takes care of that.  */
1910       input_location = DECL_SOURCE_LOCATION (fn);
1911       mark_used (fn);
1912     }
1913 }
1914
1915 /* Adjust the TLS model on variable DECL if need be, typically after
1916    the linkage of DECL has been modified.  */
1917
1918 static void
1919 adjust_var_decl_tls_model (tree decl)
1920 {
1921   if (CP_DECL_THREAD_LOCAL_P (decl)
1922       && !lookup_attribute ("tls_model", DECL_ATTRIBUTES (decl)))
1923     set_decl_tls_model (decl, decl_default_tls_model (decl));
1924 }
1925
1926 /* Set DECL up to have the closest approximation of "initialized common"
1927    linkage available.  */
1928
1929 void
1930 comdat_linkage (tree decl)
1931 {
1932   if (flag_weak)
1933     make_decl_one_only (decl, cxx_comdat_group (decl));
1934   else if (TREE_CODE (decl) == FUNCTION_DECL
1935            || (VAR_P (decl) && DECL_ARTIFICIAL (decl)))
1936     /* We can just emit function and compiler-generated variables
1937        statically; having multiple copies is (for the most part) only
1938        a waste of space.
1939
1940        There are two correctness issues, however: the address of a
1941        template instantiation with external linkage should be the
1942        same, independent of what translation unit asks for the
1943        address, and this will not hold when we emit multiple copies of
1944        the function.  However, there's little else we can do.
1945
1946        Also, by default, the typeinfo implementation assumes that
1947        there will be only one copy of the string used as the name for
1948        each type.  Therefore, if weak symbols are unavailable, the
1949        run-time library should perform a more conservative check; it
1950        should perform a string comparison, rather than an address
1951        comparison.  */
1952     TREE_PUBLIC (decl) = 0;
1953   else
1954     {
1955       /* Static data member template instantiations, however, cannot
1956          have multiple copies.  */
1957       if (DECL_INITIAL (decl) == 0
1958           || DECL_INITIAL (decl) == error_mark_node)
1959         DECL_COMMON (decl) = 1;
1960       else if (EMPTY_CONSTRUCTOR_P (DECL_INITIAL (decl)))
1961         {
1962           DECL_COMMON (decl) = 1;
1963           DECL_INITIAL (decl) = error_mark_node;
1964         }
1965       else if (!DECL_EXPLICIT_INSTANTIATION (decl))
1966         {
1967           /* We can't do anything useful; leave vars for explicit
1968              instantiation.  */
1969           DECL_EXTERNAL (decl) = 1;
1970           DECL_NOT_REALLY_EXTERN (decl) = 0;
1971         }
1972     }
1973
1974   if (TREE_PUBLIC (decl))
1975     DECL_COMDAT (decl) = 1;
1976
1977   if (VAR_P (decl))
1978     adjust_var_decl_tls_model (decl);
1979 }
1980
1981 /* For win32 we also want to put explicit instantiations in
1982    linkonce sections, so that they will be merged with implicit
1983    instantiations; otherwise we get duplicate symbol errors.
1984    For Darwin we do not want explicit instantiations to be
1985    linkonce.  */
1986
1987 void
1988 maybe_make_one_only (tree decl)
1989 {
1990   /* We used to say that this was not necessary on targets that support weak
1991      symbols, because the implicit instantiations will defer to the explicit
1992      one.  However, that's not actually the case in SVR4; a strong definition
1993      after a weak one is an error.  Also, not making explicit
1994      instantiations one_only means that we can end up with two copies of
1995      some template instantiations.  */
1996   if (! flag_weak)
1997     return;
1998
1999   /* We can't set DECL_COMDAT on functions, or cp_finish_file will think
2000      we can get away with not emitting them if they aren't used.  We need
2001      to for variables so that cp_finish_decl will update their linkage,
2002      because their DECL_INITIAL may not have been set properly yet.  */
2003
2004   if (!TARGET_WEAK_NOT_IN_ARCHIVE_TOC
2005       || (! DECL_EXPLICIT_INSTANTIATION (decl)
2006           && ! DECL_TEMPLATE_SPECIALIZATION (decl)))
2007     {
2008       make_decl_one_only (decl, cxx_comdat_group (decl));
2009
2010       if (VAR_P (decl))
2011         {
2012           varpool_node *node = varpool_node::get_create (decl);
2013           DECL_COMDAT (decl) = 1;
2014           /* Mark it needed so we don't forget to emit it.  */
2015           node->forced_by_abi = true;
2016           TREE_USED (decl) = 1;
2017
2018           adjust_var_decl_tls_model (decl);
2019         }
2020     }
2021 }
2022
2023 /* Returns true iff DECL, a FUNCTION_DECL or VAR_DECL, has vague linkage.
2024    This predicate will give the right answer during parsing of the
2025    function, which other tests may not.  */
2026
2027 bool
2028 vague_linkage_p (tree decl)
2029 {
2030   if (!TREE_PUBLIC (decl))
2031     {
2032       /* maybe_thunk_body clears TREE_PUBLIC and DECL_ABSTRACT_P on the
2033          maybe-in-charge 'tor variants; in that case we need to check one of
2034          the "clones" for the real linkage.  But only in that case; before
2035          maybe_clone_body we haven't yet copied the linkage to the clones.  */
2036       if (DECL_MAYBE_IN_CHARGE_CDTOR_P (decl)
2037           && !DECL_ABSTRACT_P (decl)
2038           && DECL_CHAIN (decl)
2039           && DECL_CLONED_FUNCTION_P (DECL_CHAIN (decl)))
2040         return vague_linkage_p (DECL_CHAIN (decl));
2041
2042       gcc_checking_assert (!DECL_COMDAT (decl));
2043       return false;
2044     }
2045   /* Unfortunately, import_export_decl has not always been called
2046      before the function is processed, so we cannot simply check
2047      DECL_COMDAT.  */
2048   if (DECL_COMDAT (decl)
2049       || (TREE_CODE (decl) == FUNCTION_DECL
2050           && DECL_DECLARED_INLINE_P (decl))
2051       || (DECL_LANG_SPECIFIC (decl)
2052           && DECL_TEMPLATE_INSTANTIATION (decl))
2053       || (VAR_P (decl) && DECL_INLINE_VAR_P (decl)))
2054     return true;
2055   else if (DECL_FUNCTION_SCOPE_P (decl))
2056     /* A local static in an inline effectively has vague linkage.  */
2057     return (TREE_STATIC (decl)
2058             && vague_linkage_p (DECL_CONTEXT (decl)));
2059   else
2060     return false;
2061 }
2062
2063 /* Determine whether or not we want to specifically import or export CTYPE,
2064    using various heuristics.  */
2065
2066 static void
2067 import_export_class (tree ctype)
2068 {
2069   /* -1 for imported, 1 for exported.  */
2070   int import_export = 0;
2071
2072   /* It only makes sense to call this function at EOF.  The reason is
2073      that this function looks at whether or not the first non-inline
2074      non-abstract virtual member function has been defined in this
2075      translation unit.  But, we can't possibly know that until we've
2076      seen the entire translation unit.  */
2077   gcc_assert (at_eof);
2078
2079   if (CLASSTYPE_INTERFACE_KNOWN (ctype))
2080     return;
2081
2082   /* If MULTIPLE_SYMBOL_SPACES is set and we saw a #pragma interface,
2083      we will have CLASSTYPE_INTERFACE_ONLY set but not
2084      CLASSTYPE_INTERFACE_KNOWN.  In that case, we don't want to use this
2085      heuristic because someone will supply a #pragma implementation
2086      elsewhere, and deducing it here would produce a conflict.  */
2087   if (CLASSTYPE_INTERFACE_ONLY (ctype))
2088     return;
2089
2090   if (lookup_attribute ("dllimport", TYPE_ATTRIBUTES (ctype)))
2091     import_export = -1;
2092   else if (lookup_attribute ("dllexport", TYPE_ATTRIBUTES (ctype)))
2093     import_export = 1;
2094   else if (CLASSTYPE_IMPLICIT_INSTANTIATION (ctype)
2095            && !flag_implicit_templates)
2096     /* For a template class, without -fimplicit-templates, check the
2097        repository.  If the virtual table is assigned to this
2098        translation unit, then export the class; otherwise, import
2099        it.  */
2100       import_export = -1;
2101   else if (TYPE_POLYMORPHIC_P (ctype))
2102     {
2103       /* The ABI specifies that the virtual table and associated
2104          information are emitted with the key method, if any.  */
2105       tree method = CLASSTYPE_KEY_METHOD (ctype);
2106       /* If weak symbol support is not available, then we must be
2107          careful not to emit the vtable when the key function is
2108          inline.  An inline function can be defined in multiple
2109          translation units.  If we were to emit the vtable in each
2110          translation unit containing a definition, we would get
2111          multiple definition errors at link-time.  */
2112       if (method && (flag_weak || ! DECL_DECLARED_INLINE_P (method)))
2113         import_export = (DECL_REALLY_EXTERN (method) ? -1 : 1);
2114     }
2115
2116   /* When MULTIPLE_SYMBOL_SPACES is set, we cannot count on seeing
2117      a definition anywhere else.  */
2118   if (MULTIPLE_SYMBOL_SPACES && import_export == -1)
2119     import_export = 0;
2120
2121   /* Allow back ends the chance to overrule the decision.  */
2122   if (targetm.cxx.import_export_class)
2123     import_export = targetm.cxx.import_export_class (ctype, import_export);
2124
2125   if (import_export)
2126     {
2127       SET_CLASSTYPE_INTERFACE_KNOWN (ctype);
2128       CLASSTYPE_INTERFACE_ONLY (ctype) = (import_export < 0);
2129     }
2130 }
2131
2132 /* Return true if VAR has already been provided to the back end; in that
2133    case VAR should not be modified further by the front end.  */
2134 static bool
2135 var_finalized_p (tree var)
2136 {
2137   return varpool_node::get_create (var)->definition;
2138 }
2139
2140 /* DECL is a VAR_DECL or FUNCTION_DECL which, for whatever reason,
2141    must be emitted in this translation unit.  Mark it as such.  */
2142
2143 void
2144 mark_needed (tree decl)
2145 {
2146   TREE_USED (decl) = 1;
2147   if (TREE_CODE (decl) == FUNCTION_DECL)
2148     {
2149       /* Extern inline functions don't become needed when referenced.
2150          If we know a method will be emitted in other TU and no new
2151          functions can be marked reachable, just use the external
2152          definition.  */
2153       struct cgraph_node *node = cgraph_node::get_create (decl);
2154       node->forced_by_abi = true;
2155
2156       /* #pragma interface can call mark_needed for
2157           maybe-in-charge 'tors; mark the clones as well.  */
2158       tree clone;
2159       FOR_EACH_CLONE (clone, decl)
2160         mark_needed (clone);
2161     }
2162   else if (VAR_P (decl))
2163     {
2164       varpool_node *node = varpool_node::get_create (decl);
2165       /* C++ frontend use mark_decl_references to force COMDAT variables
2166          to be output that might appear dead otherwise.  */
2167       node->forced_by_abi = true;
2168     }
2169 }
2170
2171 /* DECL is either a FUNCTION_DECL or a VAR_DECL.  This function
2172    returns true if a definition of this entity should be provided in
2173    this object file.  Callers use this function to determine whether
2174    or not to let the back end know that a definition of DECL is
2175    available in this translation unit.  */
2176
2177 bool
2178 decl_needed_p (tree decl)
2179 {
2180   gcc_assert (VAR_OR_FUNCTION_DECL_P (decl));
2181   /* This function should only be called at the end of the translation
2182      unit.  We cannot be sure of whether or not something will be
2183      COMDAT until that point.  */
2184   gcc_assert (at_eof);
2185
2186   /* All entities with external linkage that are not COMDAT/EXTERN should be
2187      emitted; they may be referred to from other object files.  */
2188   if (TREE_PUBLIC (decl) && !DECL_COMDAT (decl) && !DECL_REALLY_EXTERN (decl))
2189     return true;
2190   /* Functions marked "dllexport" must be emitted so that they are
2191      visible to other DLLs.  */
2192   if (flag_keep_inline_dllexport
2193       && lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl)))
2194     return true;
2195
2196   /* When not optimizing, do not bother to produce definitions for extern
2197      symbols.  */
2198   if (DECL_REALLY_EXTERN (decl)
2199       && ((TREE_CODE (decl) != FUNCTION_DECL
2200            && !optimize)
2201           || (TREE_CODE (decl) == FUNCTION_DECL
2202               && !opt_for_fn (decl, optimize)))
2203       && !lookup_attribute ("always_inline", decl))
2204     return false;
2205
2206   /* If this entity was used, let the back end see it; it will decide
2207      whether or not to emit it into the object file.  */
2208   if (TREE_USED (decl))
2209     return true;
2210
2211   /* Virtual functions might be needed for devirtualization.  */
2212   if (flag_devirtualize
2213       && TREE_CODE (decl) == FUNCTION_DECL
2214       && DECL_VIRTUAL_P (decl))
2215     return true;
2216
2217   /* Otherwise, DECL does not need to be emitted -- yet.  A subsequent
2218      reference to DECL might cause it to be emitted later.  */
2219   return false;
2220 }
2221
2222 /* If necessary, write out the vtables for the dynamic class CTYPE.
2223    Returns true if any vtables were emitted.  */
2224
2225 static bool
2226 maybe_emit_vtables (tree ctype)
2227 {
2228   tree vtbl;
2229   tree primary_vtbl;
2230   int needed = 0;
2231   varpool_node *current = NULL, *last = NULL;
2232
2233   /* If the vtables for this class have already been emitted there is
2234      nothing more to do.  */
2235   primary_vtbl = CLASSTYPE_VTABLES (ctype);
2236   if (var_finalized_p (primary_vtbl))
2237     return false;
2238   /* Ignore dummy vtables made by get_vtable_decl.  */
2239   if (TREE_TYPE (primary_vtbl) == void_type_node)
2240     return false;
2241
2242   /* On some targets, we cannot determine the key method until the end
2243      of the translation unit -- which is when this function is
2244      called.  */
2245   if (!targetm.cxx.key_method_may_be_inline ())
2246     determine_key_method (ctype);
2247
2248   /* See if any of the vtables are needed.  */
2249   for (vtbl = CLASSTYPE_VTABLES (ctype); vtbl; vtbl = DECL_CHAIN (vtbl))
2250     {
2251       import_export_decl (vtbl);
2252       if (DECL_NOT_REALLY_EXTERN (vtbl) && decl_needed_p (vtbl))
2253         needed = 1;
2254     }
2255   if (!needed)
2256     {
2257       /* If the references to this class' vtables are optimized away,
2258          still emit the appropriate debugging information.  See
2259          dfs_debug_mark.  */
2260       if (DECL_COMDAT (primary_vtbl)
2261           && CLASSTYPE_DEBUG_REQUESTED (ctype))
2262         note_debug_info_needed (ctype);
2263       return false;
2264     }
2265
2266   /* The ABI requires that we emit all of the vtables if we emit any
2267      of them.  */
2268   for (vtbl = CLASSTYPE_VTABLES (ctype); vtbl; vtbl = DECL_CHAIN (vtbl))
2269     {
2270       /* Mark entities references from the virtual table as used.  */
2271       mark_vtable_entries (vtbl);
2272
2273       if (TREE_TYPE (DECL_INITIAL (vtbl)) == 0)
2274         {
2275           vec<tree, va_gc> *cleanups = NULL;
2276           tree expr = store_init_value (vtbl, DECL_INITIAL (vtbl), &cleanups,
2277                                         LOOKUP_NORMAL);
2278
2279           /* It had better be all done at compile-time.  */
2280           gcc_assert (!expr && !cleanups);
2281         }
2282
2283       /* Write it out.  */
2284       DECL_EXTERNAL (vtbl) = 0;
2285       rest_of_decl_compilation (vtbl, 1, 1);
2286
2287       /* Because we're only doing syntax-checking, we'll never end up
2288          actually marking the variable as written.  */
2289       if (flag_syntax_only)
2290         TREE_ASM_WRITTEN (vtbl) = 1;
2291       else if (DECL_ONE_ONLY (vtbl))
2292         {
2293           current = varpool_node::get_create (vtbl);
2294           if (last)
2295             current->add_to_same_comdat_group (last);
2296           last = current;
2297         }
2298     }
2299
2300   /* For abstract classes, the destructor has been removed from the
2301      vtable (in class.c's build_vtbl_initializer).  For a compiler-
2302      generated destructor, it hence might not have been generated in
2303      this translation unit - and with '#pragma interface' it might
2304      never get generated.  */
2305   if (CLASSTYPE_PURE_VIRTUALS (ctype)
2306       && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (ctype)
2307       && !CLASSTYPE_LAZY_DESTRUCTOR (ctype)
2308       && DECL_DEFAULTED_IN_CLASS_P (CLASSTYPE_DESTRUCTOR (ctype)))
2309     note_vague_linkage_fn (CLASSTYPE_DESTRUCTOR (ctype));
2310
2311   /* Since we're writing out the vtable here, also write the debug
2312      info.  */
2313   note_debug_info_needed (ctype);
2314
2315   return true;
2316 }
2317
2318 /* A special return value from type_visibility meaning internal
2319    linkage.  */
2320
2321 enum { VISIBILITY_ANON = VISIBILITY_INTERNAL+1 };
2322
2323 static int expr_visibility (tree);
2324 static int type_visibility (tree);
2325
2326 /* walk_tree helper function for type_visibility.  */
2327
2328 static tree
2329 min_vis_r (tree *tp, int *walk_subtrees, void *data)
2330 {
2331   int *vis_p = (int *)data;
2332   if (! TYPE_P (*tp))
2333     {
2334       *walk_subtrees = 0;
2335     }
2336   else if (OVERLOAD_TYPE_P (*tp)
2337            && !TREE_PUBLIC (TYPE_MAIN_DECL (*tp)))
2338     {
2339       *vis_p = VISIBILITY_ANON;
2340       return *tp;
2341     }
2342   else if (CLASS_TYPE_P (*tp)
2343            && CLASSTYPE_VISIBILITY (*tp) > *vis_p)
2344     *vis_p = CLASSTYPE_VISIBILITY (*tp);
2345   else if (TREE_CODE (*tp) == ARRAY_TYPE
2346            && uses_template_parms (TYPE_DOMAIN (*tp)))
2347     {
2348       int evis = expr_visibility (TYPE_MAX_VALUE (TYPE_DOMAIN (*tp)));
2349       if (evis > *vis_p)
2350         *vis_p = evis;
2351     }
2352   return NULL;
2353 }
2354
2355 /* walk_tree helper function for expr_visibility.  */
2356
2357 static tree
2358 min_vis_expr_r (tree *tp, int */*walk_subtrees*/, void *data)
2359 {
2360   int *vis_p = (int *)data;
2361   int tpvis = VISIBILITY_DEFAULT;
2362
2363   switch (TREE_CODE (*tp))
2364     {
2365     case CAST_EXPR:
2366     case IMPLICIT_CONV_EXPR:
2367     case STATIC_CAST_EXPR:
2368     case REINTERPRET_CAST_EXPR:
2369     case CONST_CAST_EXPR:
2370     case DYNAMIC_CAST_EXPR:
2371     case NEW_EXPR:
2372     case CONSTRUCTOR:
2373     case LAMBDA_EXPR:
2374       tpvis = type_visibility (TREE_TYPE (*tp));
2375       break;
2376
2377     case VAR_DECL:
2378     case FUNCTION_DECL:
2379       if (! TREE_PUBLIC (*tp))
2380         tpvis = VISIBILITY_ANON;
2381       else
2382         tpvis = DECL_VISIBILITY (*tp);
2383       break;
2384
2385     default:
2386       break;
2387     }
2388
2389   if (tpvis > *vis_p)
2390     *vis_p = tpvis;
2391
2392   return NULL_TREE;
2393 }
2394
2395 /* Returns the visibility of TYPE, which is the minimum visibility of its
2396    component types.  */
2397
2398 static int
2399 type_visibility (tree type)
2400 {
2401   int vis = VISIBILITY_DEFAULT;
2402   cp_walk_tree_without_duplicates (&type, min_vis_r, &vis);
2403   return vis;
2404 }
2405
2406 /* Returns the visibility of an expression EXPR that appears in the signature
2407    of a function template, which is the minimum visibility of names that appear
2408    in its mangling.  */
2409
2410 static int
2411 expr_visibility (tree expr)
2412 {
2413   int vis = VISIBILITY_DEFAULT;
2414   cp_walk_tree_without_duplicates (&expr, min_vis_expr_r, &vis);
2415   return vis;
2416 }
2417
2418 /* Limit the visibility of DECL to VISIBILITY, if not explicitly
2419    specified (or if VISIBILITY is static).  If TMPL is true, this
2420    constraint is for a template argument, and takes precedence
2421    over explicitly-specified visibility on the template.  */
2422
2423 static void
2424 constrain_visibility (tree decl, int visibility, bool tmpl)
2425 {
2426   if (visibility == VISIBILITY_ANON)
2427     {
2428       /* extern "C" declarations aren't affected by the anonymous
2429          namespace.  */
2430       if (!DECL_EXTERN_C_P (decl))
2431         {
2432           TREE_PUBLIC (decl) = 0;
2433           DECL_WEAK (decl) = 0;
2434           DECL_COMMON (decl) = 0;
2435           DECL_COMDAT (decl) = false;
2436           if (VAR_OR_FUNCTION_DECL_P (decl))
2437             {
2438               struct symtab_node *snode = symtab_node::get (decl);
2439
2440               if (snode)
2441                 snode->set_comdat_group (NULL);
2442             }
2443           DECL_INTERFACE_KNOWN (decl) = 1;
2444           if (DECL_LANG_SPECIFIC (decl))
2445             DECL_NOT_REALLY_EXTERN (decl) = 1;
2446         }
2447     }
2448   else if (visibility > DECL_VISIBILITY (decl)
2449            && (tmpl || !DECL_VISIBILITY_SPECIFIED (decl)))
2450     {
2451       DECL_VISIBILITY (decl) = (enum symbol_visibility) visibility;
2452       /* This visibility was not specified.  */
2453       DECL_VISIBILITY_SPECIFIED (decl) = false;
2454     }
2455 }
2456
2457 /* Constrain the visibility of DECL based on the visibility of its template
2458    arguments.  */
2459
2460 static void
2461 constrain_visibility_for_template (tree decl, tree targs)
2462 {
2463   /* If this is a template instantiation, check the innermost
2464      template args for visibility constraints.  The outer template
2465      args are covered by the class check.  */
2466   tree args = INNERMOST_TEMPLATE_ARGS (targs);
2467   int i;
2468   for (i = TREE_VEC_LENGTH (args); i > 0; --i)
2469     {
2470       int vis = 0;
2471
2472       tree arg = TREE_VEC_ELT (args, i-1);
2473       if (TYPE_P (arg))
2474         vis = type_visibility (arg);
2475       else
2476         vis = expr_visibility (arg);
2477       if (vis)
2478         constrain_visibility (decl, vis, true);
2479     }
2480 }
2481
2482 /* Like c_determine_visibility, but with additional C++-specific
2483    behavior.
2484
2485    Function-scope entities can rely on the function's visibility because
2486    it is set in start_preparsed_function.
2487
2488    Class-scope entities cannot rely on the class's visibility until the end
2489    of the enclosing class definition.
2490
2491    Note that because namespaces have multiple independent definitions,
2492    namespace visibility is handled elsewhere using the #pragma visibility
2493    machinery rather than by decorating the namespace declaration.
2494
2495    The goal is for constraints from the type to give a diagnostic, and
2496    other constraints to be applied silently.  */
2497
2498 void
2499 determine_visibility (tree decl)
2500 {
2501   /* Remember that all decls get VISIBILITY_DEFAULT when built.  */
2502
2503   /* Only relevant for names with external linkage.  */
2504   if (!TREE_PUBLIC (decl))
2505     return;
2506
2507   /* Cloned constructors and destructors get the same visibility as
2508      the underlying function.  That should be set up in
2509      maybe_clone_body.  */
2510   gcc_assert (!DECL_CLONED_FUNCTION_P (decl));
2511
2512   bool orig_visibility_specified = DECL_VISIBILITY_SPECIFIED (decl);
2513   enum symbol_visibility orig_visibility = DECL_VISIBILITY (decl);
2514
2515   /* The decl may be a template instantiation, which could influence
2516      visibilty.  */
2517   tree template_decl = NULL_TREE;
2518   if (TREE_CODE (decl) == TYPE_DECL)
2519     {
2520       if (CLASS_TYPE_P (TREE_TYPE (decl)))
2521         {
2522           if (CLASSTYPE_USE_TEMPLATE (TREE_TYPE (decl)))
2523             template_decl = decl;
2524         }
2525       else if (TYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
2526         template_decl = decl;
2527     }
2528   else if (DECL_LANG_SPECIFIC (decl) && DECL_USE_TEMPLATE (decl))
2529     template_decl = decl;
2530
2531   /* If DECL is a member of a class, visibility specifiers on the
2532      class can influence the visibility of the DECL.  */
2533   tree class_type = NULL_TREE;
2534   if (DECL_CLASS_SCOPE_P (decl))
2535     class_type = DECL_CONTEXT (decl);
2536   else
2537     {
2538       /* Not a class member.  */
2539
2540       /* Virtual tables have DECL_CONTEXT set to their associated class,
2541          so they are automatically handled above.  */
2542       gcc_assert (!VAR_P (decl)
2543                   || !DECL_VTABLE_OR_VTT_P (decl));
2544
2545       if (DECL_FUNCTION_SCOPE_P (decl) && ! DECL_VISIBILITY_SPECIFIED (decl))
2546         {
2547           /* Local statics and classes get the visibility of their
2548              containing function by default, except that
2549              -fvisibility-inlines-hidden doesn't affect them.  */
2550           tree fn = DECL_CONTEXT (decl);
2551           if (DECL_VISIBILITY_SPECIFIED (fn))
2552             {
2553               DECL_VISIBILITY (decl) = DECL_VISIBILITY (fn);
2554               DECL_VISIBILITY_SPECIFIED (decl) =
2555                 DECL_VISIBILITY_SPECIFIED (fn);
2556             }
2557           else
2558             {
2559               if (DECL_CLASS_SCOPE_P (fn))
2560                 determine_visibility_from_class (decl, DECL_CONTEXT (fn));
2561               else if (determine_hidden_inline (fn))
2562                 {
2563                   DECL_VISIBILITY (decl) = default_visibility;
2564                   DECL_VISIBILITY_SPECIFIED (decl) =
2565                     visibility_options.inpragma;
2566                 }
2567               else
2568                 {
2569                   DECL_VISIBILITY (decl) = DECL_VISIBILITY (fn);
2570                   DECL_VISIBILITY_SPECIFIED (decl) =
2571                     DECL_VISIBILITY_SPECIFIED (fn);
2572                 }
2573             }
2574
2575           /* Local classes in templates have CLASSTYPE_USE_TEMPLATE set,
2576              but have no TEMPLATE_INFO, so don't try to check it.  */
2577           template_decl = NULL_TREE;
2578         }
2579       else if (VAR_P (decl) && DECL_TINFO_P (decl)
2580                && flag_visibility_ms_compat)
2581         {
2582           /* Under -fvisibility-ms-compat, types are visible by default,
2583              even though their contents aren't.  */
2584           tree underlying_type = TREE_TYPE (DECL_NAME (decl));
2585           int underlying_vis = type_visibility (underlying_type);
2586           if (underlying_vis == VISIBILITY_ANON
2587               || (CLASS_TYPE_P (underlying_type)
2588                   && CLASSTYPE_VISIBILITY_SPECIFIED (underlying_type)))
2589             constrain_visibility (decl, underlying_vis, false);
2590           else
2591             DECL_VISIBILITY (decl) = VISIBILITY_DEFAULT;
2592         }
2593       else if (VAR_P (decl) && DECL_TINFO_P (decl))
2594         {
2595           /* tinfo visibility is based on the type it's for.  */
2596           constrain_visibility
2597             (decl, type_visibility (TREE_TYPE (DECL_NAME (decl))), false);
2598
2599           /* Give the target a chance to override the visibility associated
2600              with DECL.  */
2601           if (TREE_PUBLIC (decl)
2602               && !DECL_REALLY_EXTERN (decl)
2603               && CLASS_TYPE_P (TREE_TYPE (DECL_NAME (decl)))
2604               && !CLASSTYPE_VISIBILITY_SPECIFIED (TREE_TYPE (DECL_NAME (decl))))
2605             targetm.cxx.determine_class_data_visibility (decl);
2606         }
2607       else if (template_decl)
2608         /* Template instantiations and specializations get visibility based
2609            on their template unless they override it with an attribute.  */;
2610       else if (! DECL_VISIBILITY_SPECIFIED (decl))
2611         {
2612           if (determine_hidden_inline (decl))
2613             DECL_VISIBILITY (decl) = VISIBILITY_HIDDEN;
2614           else
2615             {
2616               /* Set default visibility to whatever the user supplied with
2617                  #pragma GCC visibility or a namespace visibility attribute.  */
2618               DECL_VISIBILITY (decl) = default_visibility;
2619               DECL_VISIBILITY_SPECIFIED (decl) = visibility_options.inpragma;
2620             }
2621         }
2622     }
2623
2624   if (template_decl)
2625     {
2626       /* If the specialization doesn't specify visibility, use the
2627          visibility from the template.  */
2628       tree tinfo = get_template_info (template_decl);
2629       tree args = TI_ARGS (tinfo);
2630       tree attribs = (TREE_CODE (decl) == TYPE_DECL
2631                       ? TYPE_ATTRIBUTES (TREE_TYPE (decl))
2632                       : DECL_ATTRIBUTES (decl));
2633       tree attr = lookup_attribute ("visibility", attribs);
2634
2635       if (args != error_mark_node)
2636         {
2637           tree pattern = DECL_TEMPLATE_RESULT (TI_TEMPLATE (tinfo));
2638
2639           if (!DECL_VISIBILITY_SPECIFIED (decl))
2640             {
2641               if (!attr
2642                   && determine_hidden_inline (decl))
2643                 DECL_VISIBILITY (decl) = VISIBILITY_HIDDEN;
2644               else
2645                 {
2646                   DECL_VISIBILITY (decl) = DECL_VISIBILITY (pattern);
2647                   DECL_VISIBILITY_SPECIFIED (decl)
2648                     = DECL_VISIBILITY_SPECIFIED (pattern);
2649                 }
2650             }
2651
2652           if (args
2653               /* Template argument visibility outweighs #pragma or namespace
2654                  visibility, but not an explicit attribute.  */
2655               && !attr)
2656             {
2657               int depth = TMPL_ARGS_DEPTH (args);
2658               if (DECL_VISIBILITY_SPECIFIED (decl))
2659                 {
2660                   /* A class template member with explicit visibility
2661                      overrides the class visibility, so we need to apply
2662                      all the levels of template args directly.  */
2663                   int i;
2664                   for (i = 1; i <= depth; ++i)
2665                     {
2666                       tree lev = TMPL_ARGS_LEVEL (args, i);
2667                       constrain_visibility_for_template (decl, lev);
2668                     }
2669                 }
2670               else if (PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo)))
2671                 /* Limit visibility based on its template arguments.  */
2672                 constrain_visibility_for_template (decl, args);
2673             }
2674         }
2675     }
2676
2677   if (class_type)
2678     determine_visibility_from_class (decl, class_type);
2679
2680   if (decl_anon_ns_mem_p (decl))
2681     /* Names in an anonymous namespace get internal linkage.
2682        This might change once we implement export.  */
2683     constrain_visibility (decl, VISIBILITY_ANON, false);
2684   else if (TREE_CODE (decl) != TYPE_DECL)
2685     {
2686       /* Propagate anonymity from type to decl.  */
2687       int tvis = type_visibility (TREE_TYPE (decl));
2688       if (tvis == VISIBILITY_ANON
2689           || ! DECL_VISIBILITY_SPECIFIED (decl))
2690         constrain_visibility (decl, tvis, false);
2691     }
2692   else if (no_linkage_check (TREE_TYPE (decl), /*relaxed_p=*/true))
2693     /* DR 757: A type without linkage shall not be used as the type of a
2694        variable or function with linkage, unless
2695        o the variable or function has extern "C" linkage (7.5 [dcl.link]), or
2696        o the variable or function is not used (3.2 [basic.def.odr]) or is
2697        defined in the same translation unit.
2698
2699        Since non-extern "C" decls need to be defined in the same
2700        translation unit, we can make the type internal.  */
2701     constrain_visibility (decl, VISIBILITY_ANON, false);
2702
2703   /* If visibility changed and DECL already has DECL_RTL, ensure
2704      symbol flags are updated.  */
2705   if ((DECL_VISIBILITY (decl) != orig_visibility
2706        || DECL_VISIBILITY_SPECIFIED (decl) != orig_visibility_specified)
2707       && ((VAR_P (decl) && TREE_STATIC (decl))
2708           || TREE_CODE (decl) == FUNCTION_DECL)
2709       && DECL_RTL_SET_P (decl))
2710     make_decl_rtl (decl);
2711 }
2712
2713 /* By default, static data members and function members receive
2714    the visibility of their containing class.  */
2715
2716 static void
2717 determine_visibility_from_class (tree decl, tree class_type)
2718 {
2719   if (DECL_VISIBILITY_SPECIFIED (decl))
2720     return;
2721
2722   if (determine_hidden_inline (decl))
2723     DECL_VISIBILITY (decl) = VISIBILITY_HIDDEN;
2724   else
2725     {
2726       /* Default to the class visibility.  */
2727       DECL_VISIBILITY (decl) = CLASSTYPE_VISIBILITY (class_type);
2728       DECL_VISIBILITY_SPECIFIED (decl)
2729         = CLASSTYPE_VISIBILITY_SPECIFIED (class_type);
2730     }
2731
2732   /* Give the target a chance to override the visibility associated
2733      with DECL.  */
2734   if (VAR_P (decl)
2735       && TREE_PUBLIC (decl)
2736       && (DECL_TINFO_P (decl) || DECL_VTABLE_OR_VTT_P (decl))
2737       && !DECL_REALLY_EXTERN (decl)
2738       && !CLASSTYPE_VISIBILITY_SPECIFIED (class_type))
2739     targetm.cxx.determine_class_data_visibility (decl);
2740 }
2741
2742 /* Returns true iff DECL is an inline that should get hidden visibility
2743    because of -fvisibility-inlines-hidden.  */
2744
2745 static bool
2746 determine_hidden_inline (tree decl)
2747 {
2748   return (visibility_options.inlines_hidden
2749           /* Don't do this for inline templates; specializations might not be
2750              inline, and we don't want them to inherit the hidden
2751              visibility.  We'll set it here for all inline instantiations.  */
2752           && !processing_template_decl
2753           && TREE_CODE (decl) == FUNCTION_DECL
2754           && DECL_DECLARED_INLINE_P (decl)
2755           && (! DECL_LANG_SPECIFIC (decl)
2756               || ! DECL_EXPLICIT_INSTANTIATION (decl)));
2757 }
2758
2759 /* Constrain the visibility of a class TYPE based on the visibility of its
2760    field types.  Warn if any fields require lesser visibility.  */
2761
2762 void
2763 constrain_class_visibility (tree type)
2764 {
2765   tree binfo;
2766   tree t;
2767   int i;
2768
2769   int vis = type_visibility (type);
2770
2771   if (vis == VISIBILITY_ANON
2772       || DECL_IN_SYSTEM_HEADER (TYPE_MAIN_DECL (type)))
2773     return;
2774
2775   /* Don't warn about visibility if the class has explicit visibility.  */
2776   if (CLASSTYPE_VISIBILITY_SPECIFIED (type))
2777     vis = VISIBILITY_INTERNAL;
2778
2779   for (t = TYPE_FIELDS (type); t; t = DECL_CHAIN (t))
2780     if (TREE_CODE (t) == FIELD_DECL && TREE_TYPE (t) != error_mark_node
2781         && !DECL_ARTIFICIAL (t))
2782       {
2783         tree ftype = strip_pointer_or_array_types (TREE_TYPE (t));
2784         int subvis = type_visibility (ftype);
2785
2786         if (subvis == VISIBILITY_ANON)
2787           {
2788             if (!in_main_input_context())
2789               {
2790                 tree nlt = no_linkage_check (ftype, /*relaxed_p=*/false);
2791                 if (nlt)
2792                   {
2793                     if (same_type_p (TREE_TYPE (t), nlt))
2794                       warning (OPT_Wsubobject_linkage, "\
2795 %qT has a field %qD whose type has no linkage",
2796                                type, t);
2797                     else
2798                       warning (OPT_Wsubobject_linkage, "\
2799 %qT has a field %qD whose type depends on the type %qT which has no linkage",
2800                                type, t, nlt);
2801                   }
2802                 else
2803                   warning (OPT_Wsubobject_linkage, "\
2804 %qT has a field %qD whose type uses the anonymous namespace",
2805                            type, t);
2806               }
2807           }
2808         else if (MAYBE_CLASS_TYPE_P (ftype)
2809                  && vis < VISIBILITY_HIDDEN
2810                  && subvis >= VISIBILITY_HIDDEN)
2811           warning (OPT_Wattributes, "\
2812 %qT declared with greater visibility than the type of its field %qD",
2813                    type, t);
2814       }
2815
2816   binfo = TYPE_BINFO (type);
2817   for (i = 0; BINFO_BASE_ITERATE (binfo, i, t); ++i)
2818     {
2819       int subvis = type_visibility (TREE_TYPE (t));
2820
2821       if (subvis == VISIBILITY_ANON)
2822         {
2823           if (!in_main_input_context())
2824             {
2825               tree nlt = no_linkage_check (TREE_TYPE (t), /*relaxed_p=*/false);
2826               if (nlt)
2827                 {
2828                   if (same_type_p (TREE_TYPE (t), nlt))
2829                     warning (OPT_Wsubobject_linkage, "\
2830 %qT has a base %qT whose type has no linkage",
2831                              type, TREE_TYPE (t));
2832                   else
2833                     warning (OPT_Wsubobject_linkage, "\
2834 %qT has a base %qT whose type depends on the type %qT which has no linkage",
2835                              type, TREE_TYPE (t), nlt);
2836                 }
2837               else
2838                 warning (OPT_Wsubobject_linkage, "\
2839 %qT has a base %qT whose type uses the anonymous namespace",
2840                          type, TREE_TYPE (t));
2841             }
2842         }
2843       else if (vis < VISIBILITY_HIDDEN
2844                && subvis >= VISIBILITY_HIDDEN)
2845         warning (OPT_Wattributes, "\
2846 %qT declared with greater visibility than its base %qT",
2847                  type, TREE_TYPE (t));
2848     }
2849 }
2850
2851 /* Functions for adjusting the visibility of a tagged type and its nested
2852    types and declarations when it gets a name for linkage purposes from a
2853    typedef.  */
2854
2855 static void bt_reset_linkage_1 (binding_entry, void *);
2856 static void bt_reset_linkage_2 (binding_entry, void *);
2857
2858 /* First reset the visibility of all the types.  */
2859
2860 static void
2861 reset_type_linkage_1 (tree type)
2862 {
2863   set_linkage_according_to_type (type, TYPE_MAIN_DECL (type));
2864   if (CLASS_TYPE_P (type))
2865     binding_table_foreach (CLASSTYPE_NESTED_UTDS (type),
2866                            bt_reset_linkage_1, NULL);
2867 }
2868 static void
2869 bt_reset_linkage_1 (binding_entry b, void */*data*/)
2870 {
2871   reset_type_linkage_1 (b->type);
2872 }
2873
2874 /* Then reset the visibility of any static data members or member
2875    functions that use those types.  */
2876
2877 static void
2878 reset_decl_linkage (tree decl)
2879 {
2880   if (TREE_PUBLIC (decl))
2881     return;
2882   if (DECL_CLONED_FUNCTION_P (decl))
2883     return;
2884   TREE_PUBLIC (decl) = true;
2885   DECL_INTERFACE_KNOWN (decl) = false;
2886   determine_visibility (decl);
2887   tentative_decl_linkage (decl);
2888 }
2889
2890 static void
2891 reset_type_linkage_2 (tree type)
2892 {
2893   if (CLASS_TYPE_P (type))
2894     {
2895       if (tree vt = CLASSTYPE_VTABLES (type))
2896         {
2897           tree name = mangle_vtbl_for_type (type);
2898           DECL_NAME (vt) = name;
2899           SET_DECL_ASSEMBLER_NAME (vt, name);
2900           reset_decl_linkage (vt);
2901         }
2902       if (tree ti = CLASSTYPE_TYPEINFO_VAR (type))
2903         {
2904           tree name = mangle_typeinfo_for_type (type);
2905           DECL_NAME (ti) = name;
2906           SET_DECL_ASSEMBLER_NAME (ti, name);
2907           TREE_TYPE (name) = type;
2908           reset_decl_linkage (ti);
2909         }
2910       for (tree m = TYPE_FIELDS (type); m; m = DECL_CHAIN (m))
2911         {
2912           tree mem = STRIP_TEMPLATE (m);
2913           if (TREE_CODE (mem) == VAR_DECL || TREE_CODE (mem) == FUNCTION_DECL)
2914             reset_decl_linkage (mem);
2915         }
2916       binding_table_foreach (CLASSTYPE_NESTED_UTDS (type),
2917                              bt_reset_linkage_2, NULL);
2918     }
2919 }
2920
2921 static void
2922 bt_reset_linkage_2 (binding_entry b, void */*data*/)
2923 {
2924   reset_type_linkage_2 (b->type);
2925 }
2926 void
2927 reset_type_linkage (tree type)
2928 {
2929   reset_type_linkage_1 (type);
2930   reset_type_linkage_2 (type);
2931 }
2932
2933 /* Set up our initial idea of what the linkage of DECL should be.  */
2934
2935 void
2936 tentative_decl_linkage (tree decl)
2937 {
2938   if (DECL_INTERFACE_KNOWN (decl))
2939     /* We've already made a decision as to how this function will
2940        be handled.  */;
2941   else if (vague_linkage_p (decl))
2942     {
2943       if (TREE_CODE (decl) == FUNCTION_DECL
2944           && decl_defined_p (decl))
2945         {
2946           DECL_EXTERNAL (decl) = 1;
2947           DECL_NOT_REALLY_EXTERN (decl) = 1;
2948           note_vague_linkage_fn (decl);
2949           /* A non-template inline function with external linkage will
2950              always be COMDAT.  As we must eventually determine the
2951              linkage of all functions, and as that causes writes to
2952              the data mapped in from the PCH file, it's advantageous
2953              to mark the functions at this point.  */
2954           if (DECL_DECLARED_INLINE_P (decl)
2955               && (!DECL_IMPLICIT_INSTANTIATION (decl)
2956                   || DECL_DEFAULTED_FN (decl)))
2957             {
2958               /* This function must have external linkage, as
2959                  otherwise DECL_INTERFACE_KNOWN would have been
2960                  set.  */
2961               gcc_assert (TREE_PUBLIC (decl));
2962               comdat_linkage (decl);
2963               DECL_INTERFACE_KNOWN (decl) = 1;
2964             }
2965         }
2966       else if (VAR_P (decl))
2967         maybe_commonize_var (decl);
2968     }
2969 }
2970
2971 /* DECL is a FUNCTION_DECL or VAR_DECL.  If the object file linkage
2972    for DECL has not already been determined, do so now by setting
2973    DECL_EXTERNAL, DECL_COMDAT and other related flags.  Until this
2974    function is called entities with vague linkage whose definitions
2975    are available must have TREE_PUBLIC set.
2976
2977    If this function decides to place DECL in COMDAT, it will set
2978    appropriate flags -- but will not clear DECL_EXTERNAL.  It is up to
2979    the caller to decide whether or not to clear DECL_EXTERNAL.  Some
2980    callers defer that decision until it is clear that DECL is actually
2981    required.  */
2982
2983 void
2984 import_export_decl (tree decl)
2985 {
2986   bool comdat_p;
2987   bool import_p;
2988   tree class_type = NULL_TREE;
2989
2990   if (DECL_INTERFACE_KNOWN (decl))
2991     return;
2992
2993   /* We cannot determine what linkage to give to an entity with vague
2994      linkage until the end of the file.  For example, a virtual table
2995      for a class will be defined if and only if the key method is
2996      defined in this translation unit.  */
2997   gcc_assert (at_eof);
2998   /* Object file linkage for explicit instantiations is handled in
2999      mark_decl_instantiated.  For static variables in functions with
3000      vague linkage, maybe_commonize_var is used.
3001
3002      Therefore, the only declarations that should be provided to this
3003      function are those with external linkage that are:
3004
3005      * implicit instantiations of function templates
3006
3007      * inline function
3008
3009      * implicit instantiations of static data members of class
3010        templates
3011
3012      * virtual tables
3013
3014      * typeinfo objects
3015
3016      Furthermore, all entities that reach this point must have a
3017      definition available in this translation unit.
3018
3019      The following assertions check these conditions.  */
3020   gcc_assert (VAR_OR_FUNCTION_DECL_P (decl));
3021   /* Any code that creates entities with TREE_PUBLIC cleared should
3022      also set DECL_INTERFACE_KNOWN.  */
3023   gcc_assert (TREE_PUBLIC (decl));
3024   if (TREE_CODE (decl) == FUNCTION_DECL)
3025     gcc_assert (DECL_IMPLICIT_INSTANTIATION (decl)
3026                 || DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (decl)
3027                 || DECL_DECLARED_INLINE_P (decl));
3028   else
3029     gcc_assert (DECL_IMPLICIT_INSTANTIATION (decl)
3030                 || DECL_VTABLE_OR_VTT_P (decl)
3031                 || DECL_TINFO_P (decl));
3032   /* Check that a definition of DECL is available in this translation
3033      unit.  */
3034   gcc_assert (!DECL_REALLY_EXTERN (decl));
3035
3036   /* Assume that DECL will not have COMDAT linkage.  */
3037   comdat_p = false;
3038   /* Assume that DECL will not be imported into this translation
3039      unit.  */
3040   import_p = false;
3041
3042   if (VAR_P (decl) && DECL_VTABLE_OR_VTT_P (decl))
3043     {
3044       class_type = DECL_CONTEXT (decl);
3045       import_export_class (class_type);
3046       if (CLASSTYPE_INTERFACE_KNOWN (class_type)
3047           && CLASSTYPE_INTERFACE_ONLY (class_type))
3048         import_p = true;
3049       else if ((!flag_weak || TARGET_WEAK_NOT_IN_ARCHIVE_TOC)
3050                && !CLASSTYPE_USE_TEMPLATE (class_type)
3051                && CLASSTYPE_KEY_METHOD (class_type)
3052                && !DECL_DECLARED_INLINE_P (CLASSTYPE_KEY_METHOD (class_type)))
3053         /* The ABI requires that all virtual tables be emitted with
3054            COMDAT linkage.  However, on systems where COMDAT symbols
3055            don't show up in the table of contents for a static
3056            archive, or on systems without weak symbols (where we
3057            approximate COMDAT linkage by using internal linkage), the
3058            linker will report errors about undefined symbols because
3059            it will not see the virtual table definition.  Therefore,
3060            in the case that we know that the virtual table will be
3061            emitted in only one translation unit, we make the virtual
3062            table an ordinary definition with external linkage.  */
3063         DECL_EXTERNAL (decl) = 0;
3064       else if (CLASSTYPE_INTERFACE_KNOWN (class_type))
3065         {
3066           /* CLASS_TYPE is being exported from this translation unit,
3067              so DECL should be defined here.  */
3068           if (!flag_weak && CLASSTYPE_EXPLICIT_INSTANTIATION (class_type))
3069             /* If a class is declared in a header with the "extern
3070                template" extension, then it will not be instantiated,
3071                even in translation units that would normally require
3072                it.  Often such classes are explicitly instantiated in
3073                one translation unit.  Therefore, the explicit
3074                instantiation must be made visible to other translation
3075                units.  */
3076             DECL_EXTERNAL (decl) = 0;
3077           else
3078             {
3079               /* The generic C++ ABI says that class data is always
3080                  COMDAT, even if there is a key function.  Some
3081                  variants (e.g., the ARM EABI) says that class data
3082                  only has COMDAT linkage if the class data might be
3083                  emitted in more than one translation unit.  When the
3084                  key method can be inline and is inline, we still have
3085                  to arrange for comdat even though
3086                  class_data_always_comdat is false.  */
3087               if (!CLASSTYPE_KEY_METHOD (class_type)
3088                   || DECL_DECLARED_INLINE_P (CLASSTYPE_KEY_METHOD (class_type))
3089                   || targetm.cxx.class_data_always_comdat ())
3090                 {
3091                   /* The ABI requires COMDAT linkage.  Normally, we
3092                      only emit COMDAT things when they are needed;
3093                      make sure that we realize that this entity is
3094                      indeed needed.  */
3095                   comdat_p = true;
3096                   mark_needed (decl);
3097                 }
3098             }
3099         }
3100       else if (!flag_implicit_templates
3101                && CLASSTYPE_IMPLICIT_INSTANTIATION (class_type))
3102         import_p = true;
3103       else
3104         comdat_p = true;
3105     }
3106   else if (VAR_P (decl) && DECL_TINFO_P (decl))
3107     {
3108       tree type = TREE_TYPE (DECL_NAME (decl));
3109       if (CLASS_TYPE_P (type))
3110         {
3111           class_type = type;
3112           import_export_class (type);
3113           if (CLASSTYPE_INTERFACE_KNOWN (type)
3114               && TYPE_POLYMORPHIC_P (type)
3115               && CLASSTYPE_INTERFACE_ONLY (type)
3116               /* If -fno-rtti was specified, then we cannot be sure
3117                  that RTTI information will be emitted with the
3118                  virtual table of the class, so we must emit it
3119                  wherever it is used.  */
3120               && flag_rtti)
3121             import_p = true;
3122           else
3123             {
3124               if (CLASSTYPE_INTERFACE_KNOWN (type)
3125                   && !CLASSTYPE_INTERFACE_ONLY (type))
3126                 {
3127                   comdat_p = (targetm.cxx.class_data_always_comdat ()
3128                               || (CLASSTYPE_KEY_METHOD (type)
3129                                   && DECL_DECLARED_INLINE_P (CLASSTYPE_KEY_METHOD (type))));
3130                   mark_needed (decl);
3131                   if (!flag_weak)
3132                     {
3133                       comdat_p = false;
3134                       DECL_EXTERNAL (decl) = 0;
3135                     }
3136                 }
3137               else
3138                 comdat_p = true;
3139             }
3140         }
3141       else
3142         comdat_p = true;
3143     }
3144   else if (DECL_TEMPLOID_INSTANTIATION (decl))
3145     {
3146       /* DECL is an implicit instantiation of a function or static
3147          data member.  */
3148       if (flag_implicit_templates
3149           || (flag_implicit_inline_templates
3150               && TREE_CODE (decl) == FUNCTION_DECL
3151               && DECL_DECLARED_INLINE_P (decl)))
3152         comdat_p = true;
3153       else
3154         /* If we are not implicitly generating templates, then mark
3155            this entity as undefined in this translation unit.  */
3156         import_p = true;
3157     }
3158   else if (DECL_FUNCTION_MEMBER_P (decl))
3159     {
3160       if (!DECL_DECLARED_INLINE_P (decl))
3161         {
3162           tree ctype = DECL_CONTEXT (decl);
3163           import_export_class (ctype);
3164           if (CLASSTYPE_INTERFACE_KNOWN (ctype))
3165             {
3166               DECL_NOT_REALLY_EXTERN (decl)
3167                 = ! (CLASSTYPE_INTERFACE_ONLY (ctype)
3168                      || (DECL_DECLARED_INLINE_P (decl)
3169                          && ! flag_implement_inlines
3170                          && !DECL_VINDEX (decl)));
3171
3172               if (!DECL_NOT_REALLY_EXTERN (decl))
3173                 DECL_EXTERNAL (decl) = 1;
3174
3175               /* Always make artificials weak.  */
3176               if (DECL_ARTIFICIAL (decl) && flag_weak)
3177                 comdat_p = true;
3178               else
3179                 maybe_make_one_only (decl);
3180             }
3181         }
3182       else
3183         comdat_p = true;
3184     }
3185   else
3186     comdat_p = true;
3187
3188   if (import_p)
3189     {
3190       /* If we are importing DECL into this translation unit, mark is
3191          an undefined here.  */
3192       DECL_EXTERNAL (decl) = 1;
3193       DECL_NOT_REALLY_EXTERN (decl) = 0;
3194     }
3195   else if (comdat_p)
3196     {
3197       /* If we decided to put DECL in COMDAT, mark it accordingly at
3198          this point.  */
3199       comdat_linkage (decl);
3200     }
3201
3202   DECL_INTERFACE_KNOWN (decl) = 1;
3203 }
3204
3205 /* Return an expression that performs the destruction of DECL, which
3206    must be a VAR_DECL whose type has a non-trivial destructor, or is
3207    an array whose (innermost) elements have a non-trivial destructor.  */
3208
3209 tree
3210 build_cleanup (tree decl)
3211 {
3212   tree clean = cxx_maybe_build_cleanup (decl, tf_warning_or_error);
3213   gcc_assert (clean != NULL_TREE);
3214   return clean;
3215 }
3216
3217 /* GUARD is a helper variable for DECL; make them have the same linkage and
3218    visibility.  */
3219
3220 void
3221 copy_linkage (tree guard, tree decl)
3222 {
3223   TREE_PUBLIC (guard) = TREE_PUBLIC (decl);
3224   TREE_STATIC (guard) = TREE_STATIC (decl);
3225   DECL_COMMON (guard) = DECL_COMMON (decl);
3226   DECL_COMDAT (guard) = DECL_COMDAT (decl);
3227   if (TREE_STATIC (guard))
3228     {
3229       CP_DECL_THREAD_LOCAL_P (guard) = CP_DECL_THREAD_LOCAL_P (decl);
3230       set_decl_tls_model (guard, DECL_TLS_MODEL (decl));
3231       if (DECL_ONE_ONLY (decl))
3232         make_decl_one_only (guard, cxx_comdat_group (guard));
3233       if (TREE_PUBLIC (decl))
3234         DECL_WEAK (guard) = DECL_WEAK (decl);
3235       /* Also check vague_linkage_p, as DECL_WEAK and DECL_ONE_ONLY might not
3236          be set until import_export_decl at EOF.  */
3237       if (vague_linkage_p (decl))
3238         comdat_linkage (guard);
3239       DECL_VISIBILITY (guard) = DECL_VISIBILITY (decl);
3240       DECL_VISIBILITY_SPECIFIED (guard) = DECL_VISIBILITY_SPECIFIED (decl);
3241     }
3242 }
3243
3244 /* Returns the initialization guard variable for the variable DECL,
3245    which has static storage duration.  */
3246
3247 tree
3248 get_guard (tree decl)
3249 {
3250   tree sname;
3251   tree guard;
3252
3253   sname = mangle_guard_variable (decl);
3254   guard = get_global_binding (sname);
3255   if (! guard)
3256     {
3257       tree guard_type;
3258
3259       /* We use a type that is big enough to contain a mutex as well
3260          as an integer counter.  */
3261       guard_type = targetm.cxx.guard_type ();
3262       guard = build_decl (DECL_SOURCE_LOCATION (decl),
3263                           VAR_DECL, sname, guard_type);
3264
3265       /* The guard should have the same linkage as what it guards.  */
3266       copy_linkage (guard, decl);
3267
3268       DECL_ARTIFICIAL (guard) = 1;
3269       DECL_IGNORED_P (guard) = 1;
3270       TREE_USED (guard) = 1;
3271       pushdecl_top_level_and_finish (guard, NULL_TREE);
3272     }
3273   return guard;
3274 }
3275
3276 /* Return an atomic load of src with the appropriate memory model.  */
3277
3278 static tree
3279 build_atomic_load_byte (tree src, HOST_WIDE_INT model)
3280 {
3281   tree ptr_type = build_pointer_type (char_type_node);
3282   tree mem_model = build_int_cst (integer_type_node, model);
3283   tree t, addr, val;
3284   unsigned int size;
3285   int fncode;
3286
3287   size = tree_to_uhwi (TYPE_SIZE_UNIT (char_type_node));
3288
3289   fncode = BUILT_IN_ATOMIC_LOAD_N + exact_log2 (size) + 1;
3290   t = builtin_decl_implicit ((enum built_in_function) fncode);
3291
3292   addr = build1 (ADDR_EXPR, ptr_type, src);
3293   val = build_call_expr (t, 2, addr, mem_model);
3294   return val;
3295 }
3296
3297 /* Return those bits of the GUARD variable that should be set when the
3298    guarded entity is actually initialized.  */
3299
3300 static tree
3301 get_guard_bits (tree guard)
3302 {
3303   if (!targetm.cxx.guard_mask_bit ())
3304     {
3305       /* We only set the first byte of the guard, in order to leave room
3306          for a mutex in the high-order bits.  */
3307       guard = build1 (ADDR_EXPR,
3308                       build_pointer_type (TREE_TYPE (guard)),
3309                       guard);
3310       guard = build1 (NOP_EXPR,
3311                       build_pointer_type (char_type_node),
3312                       guard);
3313       guard = build1 (INDIRECT_REF, char_type_node, guard);
3314     }
3315
3316   return guard;
3317 }
3318
3319 /* Return an expression which determines whether or not the GUARD
3320    variable has already been initialized.  */
3321
3322 tree
3323 get_guard_cond (tree guard, bool thread_safe)
3324 {
3325   tree guard_value;
3326
3327   if (!thread_safe)
3328     guard = get_guard_bits (guard);
3329   else
3330     guard = build_atomic_load_byte (guard, MEMMODEL_ACQUIRE);
3331
3332   /* Mask off all but the low bit.  */
3333   if (targetm.cxx.guard_mask_bit ())
3334     {
3335       guard_value = integer_one_node;
3336       if (!same_type_p (TREE_TYPE (guard_value), TREE_TYPE (guard)))
3337         guard_value = fold_convert (TREE_TYPE (guard), guard_value);
3338       guard = cp_build_binary_op (input_location,
3339                                   BIT_AND_EXPR, guard, guard_value,
3340                                   tf_warning_or_error);
3341     }
3342
3343   guard_value = integer_zero_node;
3344   if (!same_type_p (TREE_TYPE (guard_value), TREE_TYPE (guard)))
3345     guard_value = fold_convert (TREE_TYPE (guard), guard_value);
3346   return cp_build_binary_op (input_location,
3347                              EQ_EXPR, guard, guard_value,
3348                              tf_warning_or_error);
3349 }
3350
3351 /* Return an expression which sets the GUARD variable, indicating that
3352    the variable being guarded has been initialized.  */
3353
3354 tree
3355 set_guard (tree guard)
3356 {
3357   tree guard_init;
3358
3359   /* Set the GUARD to one.  */
3360   guard = get_guard_bits (guard);
3361   guard_init = integer_one_node;
3362   if (!same_type_p (TREE_TYPE (guard_init), TREE_TYPE (guard)))
3363     guard_init = fold_convert (TREE_TYPE (guard), guard_init);
3364   return cp_build_modify_expr (input_location, guard, NOP_EXPR, guard_init,
3365                                tf_warning_or_error);
3366 }
3367
3368 /* Returns true iff we can tell that VAR does not have a dynamic
3369    initializer.  */
3370
3371 static bool
3372 var_defined_without_dynamic_init (tree var)
3373 {
3374   /* If it's defined in another TU, we can't tell.  */
3375   if (DECL_EXTERNAL (var))
3376     return false;
3377   /* If it has a non-trivial destructor, registering the destructor
3378      counts as dynamic initialization.  */
3379   if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TREE_TYPE (var)))
3380     return false;
3381   /* If it's in this TU, its initializer has been processed, unless
3382      it's a case of self-initialization, then DECL_INITIALIZED_P is
3383      false while the initializer is handled by finish_id_expression.  */
3384   if (!DECL_INITIALIZED_P (var))
3385     return false;
3386   /* If it has no initializer or a constant one, it's not dynamic.  */
3387   return (!DECL_NONTRIVIALLY_INITIALIZED_P (var)
3388           || DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (var));
3389 }
3390
3391 /* Returns true iff VAR is a variable that needs uses to be
3392    wrapped for possible dynamic initialization.  */
3393
3394 static bool
3395 var_needs_tls_wrapper (tree var)
3396 {
3397   return (!error_operand_p (var)
3398           && CP_DECL_THREAD_LOCAL_P (var)
3399           && !DECL_GNU_TLS_P (var)
3400           && !DECL_FUNCTION_SCOPE_P (var)
3401           && !var_defined_without_dynamic_init (var));
3402 }
3403
3404 /* Get the FUNCTION_DECL for the shared TLS init function for this
3405    translation unit.  */
3406
3407 static tree
3408 get_local_tls_init_fn (location_t loc)
3409 {
3410   tree sname = get_identifier ("__tls_init");
3411   tree fn = get_global_binding (sname);
3412   if (!fn)
3413     {
3414       fn = build_lang_decl_loc (loc, FUNCTION_DECL, sname,
3415                                 build_function_type (void_type_node,
3416                                                      void_list_node));
3417       SET_DECL_LANGUAGE (fn, lang_c);
3418       TREE_PUBLIC (fn) = false;
3419       DECL_ARTIFICIAL (fn) = true;
3420       mark_used (fn);
3421       set_global_binding (fn);
3422     }
3423   return fn;
3424 }
3425
3426 /* Get a FUNCTION_DECL for the init function for the thread_local
3427    variable VAR.  The init function will be an alias to the function
3428    that initializes all the non-local TLS variables in the translation
3429    unit.  The init function is only used by the wrapper function.  */
3430
3431 static tree
3432 get_tls_init_fn (tree var)
3433 {
3434   /* Only C++11 TLS vars need this init fn.  */
3435   if (!var_needs_tls_wrapper (var))
3436     return NULL_TREE;
3437
3438   /* If -fno-extern-tls-init, assume that we don't need to call
3439      a tls init function for a variable defined in another TU.  */
3440   if (!flag_extern_tls_init && DECL_EXTERNAL (var))
3441     return NULL_TREE;
3442
3443   /* If the variable is internal, or if we can't generate aliases,
3444      call the local init function directly.  */
3445   if (!TREE_PUBLIC (var) || !TARGET_SUPPORTS_ALIASES)
3446     return get_local_tls_init_fn (DECL_SOURCE_LOCATION (var));
3447
3448   tree sname = mangle_tls_init_fn (var);
3449   tree fn = get_global_binding (sname);
3450   if (!fn)
3451     {
3452       fn = build_lang_decl (FUNCTION_DECL, sname,
3453                             build_function_type (void_type_node,
3454                                                  void_list_node));
3455       SET_DECL_LANGUAGE (fn, lang_c);
3456       TREE_PUBLIC (fn) = TREE_PUBLIC (var);
3457       DECL_ARTIFICIAL (fn) = true;
3458       DECL_COMDAT (fn) = DECL_COMDAT (var);
3459       DECL_EXTERNAL (fn) = DECL_EXTERNAL (var);
3460       if (DECL_ONE_ONLY (var))
3461         make_decl_one_only (fn, cxx_comdat_group (fn));
3462       if (TREE_PUBLIC (var))
3463         {
3464           tree obtype = strip_array_types (non_reference (TREE_TYPE (var)));
3465           /* If the variable is defined somewhere else and might have static
3466              initialization, make the init function a weak reference.  */
3467           if ((!TYPE_NEEDS_CONSTRUCTING (obtype)
3468                || TYPE_HAS_CONSTEXPR_CTOR (obtype)
3469                || TYPE_HAS_TRIVIAL_DFLT (obtype))
3470               && TYPE_HAS_TRIVIAL_DESTRUCTOR (obtype)
3471               && DECL_EXTERNAL (var))
3472             declare_weak (fn);
3473           else
3474             DECL_WEAK (fn) = DECL_WEAK (var);
3475         }
3476       DECL_VISIBILITY (fn) = DECL_VISIBILITY (var);
3477       DECL_VISIBILITY_SPECIFIED (fn) = DECL_VISIBILITY_SPECIFIED (var);
3478       DECL_DLLIMPORT_P (fn) = DECL_DLLIMPORT_P (var);
3479       DECL_IGNORED_P (fn) = 1;
3480       mark_used (fn);
3481
3482       DECL_BEFRIENDING_CLASSES (fn) = var;
3483
3484       set_global_binding (fn);
3485     }
3486   return fn;
3487 }
3488
3489 /* Get a FUNCTION_DECL for the init wrapper function for the thread_local
3490    variable VAR.  The wrapper function calls the init function (if any) for
3491    VAR and then returns a reference to VAR.  The wrapper function is used
3492    in place of VAR everywhere VAR is mentioned.  */
3493
3494 static tree
3495 get_tls_wrapper_fn (tree var)
3496 {
3497   /* Only C++11 TLS vars need this wrapper fn.  */
3498   if (!var_needs_tls_wrapper (var))
3499     return NULL_TREE;
3500
3501   tree sname = mangle_tls_wrapper_fn (var);
3502   tree fn = get_global_binding (sname);
3503   if (!fn)
3504     {
3505       /* A named rvalue reference is an lvalue, so the wrapper should
3506          always return an lvalue reference.  */
3507       tree type = non_reference (TREE_TYPE (var));
3508       type = build_reference_type (type);
3509       tree fntype = build_function_type (type, void_list_node);
3510
3511       fn = build_lang_decl_loc (DECL_SOURCE_LOCATION (var),
3512                                 FUNCTION_DECL, sname, fntype);
3513       SET_DECL_LANGUAGE (fn, lang_c);
3514       TREE_PUBLIC (fn) = TREE_PUBLIC (var);
3515       DECL_ARTIFICIAL (fn) = true;
3516       DECL_IGNORED_P (fn) = 1;
3517       /* The wrapper is inline and emitted everywhere var is used.  */
3518       DECL_DECLARED_INLINE_P (fn) = true;
3519       if (TREE_PUBLIC (var))
3520         {
3521           comdat_linkage (fn);
3522 #ifdef HAVE_GAS_HIDDEN
3523           /* Make the wrapper bind locally; there's no reason to share
3524              the wrapper between multiple shared objects.  */
3525           DECL_VISIBILITY (fn) = VISIBILITY_INTERNAL;
3526           DECL_VISIBILITY_SPECIFIED (fn) = true;
3527 #endif
3528         }
3529       if (!TREE_PUBLIC (fn))
3530         DECL_INTERFACE_KNOWN (fn) = true;
3531       mark_used (fn);
3532       note_vague_linkage_fn (fn);
3533
3534 #if 0
3535       /* We want CSE to commonize calls to the wrapper, but marking it as
3536          pure is unsafe since it has side-effects.  I guess we need a new
3537          ECF flag even weaker than ECF_PURE.  FIXME!  */
3538       DECL_PURE_P (fn) = true;
3539 #endif
3540
3541       DECL_BEFRIENDING_CLASSES (fn) = var;
3542
3543       set_global_binding (fn);
3544     }
3545   return fn;
3546 }
3547
3548 /* If EXPR is a thread_local variable that should be wrapped by init
3549    wrapper function, return a call to that function, otherwise return
3550    NULL.  */
3551
3552 tree
3553 maybe_get_tls_wrapper_call (tree expr)
3554 {
3555   if (VAR_P (expr)
3556       && !processing_template_decl
3557       && !cp_unevaluated_operand
3558       && CP_DECL_THREAD_LOCAL_P (expr))
3559     if (tree wrap = get_tls_wrapper_fn (expr))
3560       return build_cxx_call (wrap, 0, NULL, tf_warning_or_error);
3561   return NULL;
3562 }
3563
3564 /* At EOF, generate the definition for the TLS wrapper function FN:
3565
3566    T& var_wrapper() {
3567      if (init_fn) init_fn();
3568      return var;
3569    }  */
3570
3571 static void
3572 generate_tls_wrapper (tree fn)
3573 {
3574   tree var = DECL_BEFRIENDING_CLASSES (fn);
3575
3576   start_preparsed_function (fn, NULL_TREE, SF_DEFAULT | SF_PRE_PARSED);
3577   tree body = begin_function_body ();
3578   /* Only call the init fn if there might be one.  */
3579   if (tree init_fn = get_tls_init_fn (var))
3580     {
3581       tree if_stmt = NULL_TREE;
3582       /* If init_fn is a weakref, make sure it exists before calling.  */
3583       if (lookup_attribute ("weak", DECL_ATTRIBUTES (init_fn)))
3584         {
3585           if_stmt = begin_if_stmt ();
3586           tree addr = cp_build_addr_expr (init_fn, tf_warning_or_error);
3587           tree cond = cp_build_binary_op (DECL_SOURCE_LOCATION (var),
3588                                           NE_EXPR, addr, nullptr_node,
3589                                           tf_warning_or_error);
3590           finish_if_stmt_cond (cond, if_stmt);
3591         }
3592       finish_expr_stmt (build_cxx_call
3593                         (init_fn, 0, NULL, tf_warning_or_error));
3594       if (if_stmt)
3595         {
3596           finish_then_clause (if_stmt);
3597           finish_if_stmt (if_stmt);
3598         }
3599     }
3600   else
3601     /* If there's no initialization, the wrapper is a constant function.  */
3602     TREE_READONLY (fn) = true;
3603   finish_return_stmt (convert_from_reference (var));
3604   finish_function_body (body);
3605   expand_or_defer_fn (finish_function (/*inline_p=*/false));
3606 }
3607
3608 /* Start the process of running a particular set of global constructors
3609    or destructors.  Subroutine of do_[cd]tors.  Also called from
3610    vtv_start_verification_constructor_init_function.  */
3611
3612 static tree
3613 start_objects (int method_type, int initp)
3614 {
3615   tree body;
3616   tree fndecl;
3617   char type[14];
3618
3619   /* Make ctor or dtor function.  METHOD_TYPE may be 'I' or 'D'.  */
3620
3621   if (initp != DEFAULT_INIT_PRIORITY)
3622     {
3623       char joiner;
3624
3625 #ifdef JOINER
3626       joiner = JOINER;
3627 #else
3628       joiner = '_';
3629 #endif
3630
3631       sprintf (type, "sub_%c%c%.5u", method_type, joiner, initp);
3632     }
3633   else
3634     sprintf (type, "sub_%c", method_type);
3635
3636   fndecl = build_lang_decl (FUNCTION_DECL,
3637                             get_file_function_name (type),
3638                             build_function_type_list (void_type_node,
3639                                                       NULL_TREE));
3640   start_preparsed_function (fndecl, /*attrs=*/NULL_TREE, SF_PRE_PARSED);
3641
3642   TREE_PUBLIC (current_function_decl) = 0;
3643
3644   /* Mark as artificial because it's not explicitly in the user's
3645      source code.  */
3646   DECL_ARTIFICIAL (current_function_decl) = 1;
3647
3648   /* Mark this declaration as used to avoid spurious warnings.  */
3649   TREE_USED (current_function_decl) = 1;
3650
3651   /* Mark this function as a global constructor or destructor.  */
3652   if (method_type == 'I')
3653     DECL_GLOBAL_CTOR_P (current_function_decl) = 1;
3654   else
3655     DECL_GLOBAL_DTOR_P (current_function_decl) = 1;
3656
3657   body = begin_compound_stmt (BCS_FN_BODY);
3658
3659   return body;
3660 }
3661
3662 /* Finish the process of running a particular set of global constructors
3663    or destructors.  Subroutine of do_[cd]tors.  */
3664
3665 static void
3666 finish_objects (int method_type, int initp, tree body)
3667 {
3668   tree fn;
3669
3670   /* Finish up.  */
3671   finish_compound_stmt (body);
3672   fn = finish_function (/*inline_p=*/false);
3673
3674   if (method_type == 'I')
3675     {
3676       DECL_STATIC_CONSTRUCTOR (fn) = 1;
3677       decl_init_priority_insert (fn, initp);
3678     }
3679   else
3680     {
3681       DECL_STATIC_DESTRUCTOR (fn) = 1;
3682       decl_fini_priority_insert (fn, initp);
3683     }
3684
3685   expand_or_defer_fn (fn);
3686 }
3687
3688 /* The names of the parameters to the function created to handle
3689    initializations and destructions for objects with static storage
3690    duration.  */
3691 #define INITIALIZE_P_IDENTIFIER "__initialize_p"
3692 #define PRIORITY_IDENTIFIER "__priority"
3693
3694 /* The name of the function we create to handle initializations and
3695    destructions for objects with static storage duration.  */
3696 #define SSDF_IDENTIFIER "__static_initialization_and_destruction"
3697
3698 /* The declaration for the __INITIALIZE_P argument.  */
3699 static GTY(()) tree initialize_p_decl;
3700
3701 /* The declaration for the __PRIORITY argument.  */
3702 static GTY(()) tree priority_decl;
3703
3704 /* The declaration for the static storage duration function.  */
3705 static GTY(()) tree ssdf_decl;
3706
3707 /* All the static storage duration functions created in this
3708    translation unit.  */
3709 static GTY(()) vec<tree, va_gc> *ssdf_decls;
3710
3711 /* A map from priority levels to information about that priority
3712    level.  There may be many such levels, so efficient lookup is
3713    important.  */
3714 static splay_tree priority_info_map;
3715
3716 /* Begins the generation of the function that will handle all
3717    initialization and destruction of objects with static storage
3718    duration.  The function generated takes two parameters of type
3719    `int': __INITIALIZE_P and __PRIORITY.  If __INITIALIZE_P is
3720    nonzero, it performs initializations.  Otherwise, it performs
3721    destructions.  It only performs those initializations or
3722    destructions with the indicated __PRIORITY.  The generated function
3723    returns no value.
3724
3725    It is assumed that this function will only be called once per
3726    translation unit.  */
3727
3728 static tree
3729 start_static_storage_duration_function (unsigned count)
3730 {
3731   tree type;
3732   tree body;
3733   char id[sizeof (SSDF_IDENTIFIER) + 1 /* '\0' */ + 32];
3734
3735   /* Create the identifier for this function.  It will be of the form
3736      SSDF_IDENTIFIER_<number>.  */
3737   sprintf (id, "%s_%u", SSDF_IDENTIFIER, count);
3738
3739   type = build_function_type_list (void_type_node,
3740                                    integer_type_node, integer_type_node,
3741                                    NULL_TREE);
3742
3743   /* Create the FUNCTION_DECL itself.  */
3744   ssdf_decl = build_lang_decl (FUNCTION_DECL,
3745                                get_identifier (id),
3746                                type);
3747   TREE_PUBLIC (ssdf_decl) = 0;
3748   DECL_ARTIFICIAL (ssdf_decl) = 1;
3749
3750   /* Put this function in the list of functions to be called from the
3751      static constructors and destructors.  */
3752   if (!ssdf_decls)
3753     {
3754       vec_alloc (ssdf_decls, 32);
3755
3756       /* Take this opportunity to initialize the map from priority
3757          numbers to information about that priority level.  */
3758       priority_info_map = splay_tree_new (splay_tree_compare_ints,
3759                                           /*delete_key_fn=*/0,
3760                                           /*delete_value_fn=*/
3761                                           splay_tree_delete_pointers);
3762
3763       /* We always need to generate functions for the
3764          DEFAULT_INIT_PRIORITY so enter it now.  That way when we walk
3765          priorities later, we'll be sure to find the
3766          DEFAULT_INIT_PRIORITY.  */
3767       get_priority_info (DEFAULT_INIT_PRIORITY);
3768     }
3769
3770   vec_safe_push (ssdf_decls, ssdf_decl);
3771
3772   /* Create the argument list.  */
3773   initialize_p_decl = cp_build_parm_decl
3774     (ssdf_decl, get_identifier (INITIALIZE_P_IDENTIFIER), integer_type_node);
3775   TREE_USED (initialize_p_decl) = 1;
3776   priority_decl = cp_build_parm_decl
3777     (ssdf_decl, get_identifier (PRIORITY_IDENTIFIER), integer_type_node);
3778   TREE_USED (priority_decl) = 1;
3779
3780   DECL_CHAIN (initialize_p_decl) = priority_decl;
3781   DECL_ARGUMENTS (ssdf_decl) = initialize_p_decl;
3782
3783   /* Put the function in the global scope.  */
3784   pushdecl (ssdf_decl);
3785
3786   /* Start the function itself.  This is equivalent to declaring the
3787      function as:
3788
3789        static void __ssdf (int __initialize_p, init __priority_p);
3790
3791      It is static because we only need to call this function from the
3792      various constructor and destructor functions for this module.  */
3793   start_preparsed_function (ssdf_decl,
3794                             /*attrs=*/NULL_TREE,
3795                             SF_PRE_PARSED);
3796
3797   /* Set up the scope of the outermost block in the function.  */
3798   body = begin_compound_stmt (BCS_FN_BODY);
3799
3800   return body;
3801 }
3802
3803 /* Finish the generation of the function which performs initialization
3804    and destruction of objects with static storage duration.  After
3805    this point, no more such objects can be created.  */
3806
3807 static void
3808 finish_static_storage_duration_function (tree body)
3809 {
3810   /* Close out the function.  */
3811   finish_compound_stmt (body);
3812   expand_or_defer_fn (finish_function (/*inline_p=*/false));
3813 }
3814
3815 /* Return the information about the indicated PRIORITY level.  If no
3816    code to handle this level has yet been generated, generate the
3817    appropriate prologue.  */
3818
3819 static priority_info
3820 get_priority_info (int priority)
3821 {
3822   priority_info pi;
3823   splay_tree_node n;
3824
3825   n = splay_tree_lookup (priority_info_map,
3826                          (splay_tree_key) priority);
3827   if (!n)
3828     {
3829       /* Create a new priority information structure, and insert it
3830          into the map.  */
3831       pi = XNEW (struct priority_info_s);
3832       pi->initializations_p = 0;
3833       pi->destructions_p = 0;
3834       splay_tree_insert (priority_info_map,
3835                          (splay_tree_key) priority,
3836                          (splay_tree_value) pi);
3837     }
3838   else
3839     pi = (priority_info) n->value;
3840
3841   return pi;
3842 }
3843
3844 /* The effective initialization priority of a DECL.  */
3845
3846 #define DECL_EFFECTIVE_INIT_PRIORITY(decl)                                    \
3847         ((!DECL_HAS_INIT_PRIORITY_P (decl) || DECL_INIT_PRIORITY (decl) == 0) \
3848          ? DEFAULT_INIT_PRIORITY : DECL_INIT_PRIORITY (decl))
3849
3850 /* Whether a DECL needs a guard to protect it against multiple
3851    initialization.  */
3852
3853 #define NEEDS_GUARD_P(decl) (TREE_PUBLIC (decl) && (DECL_COMMON (decl)      \
3854                                                     || DECL_ONE_ONLY (decl) \
3855                                                     || DECL_WEAK (decl)))
3856
3857 /* Called from one_static_initialization_or_destruction(),
3858    via walk_tree.
3859    Walks the initializer list of a global variable and looks for
3860    temporary variables (DECL_NAME() == NULL and DECL_ARTIFICIAL != 0)
3861    and that have their DECL_CONTEXT() == NULL.
3862    For each such temporary variable, set their DECL_CONTEXT() to
3863    the current function. This is necessary because otherwise
3864    some optimizers (enabled by -O2 -fprofile-arcs) might crash
3865    when trying to refer to a temporary variable that does not have
3866    it's DECL_CONTECT() properly set.  */
3867 static tree
3868 fix_temporary_vars_context_r (tree *node,
3869                               int  * /*unused*/,
3870                               void * /*unused1*/)
3871 {
3872   gcc_assert (current_function_decl);
3873
3874   if (TREE_CODE (*node) == BIND_EXPR)
3875     {
3876       tree var;
3877
3878       for (var = BIND_EXPR_VARS (*node); var; var = DECL_CHAIN (var))
3879         if (VAR_P (var)
3880           && !DECL_NAME (var)
3881           && DECL_ARTIFICIAL (var)
3882           && !DECL_CONTEXT (var))
3883           DECL_CONTEXT (var) = current_function_decl;
3884     }
3885
3886   return NULL_TREE;
3887 }
3888
3889 /* Set up to handle the initialization or destruction of DECL.  If
3890    INITP is nonzero, we are initializing the variable.  Otherwise, we
3891    are destroying it.  */
3892
3893 static void
3894 one_static_initialization_or_destruction (tree decl, tree init, bool initp)
3895 {
3896   tree guard_if_stmt = NULL_TREE;
3897   tree guard;
3898
3899   /* If we are supposed to destruct and there's a trivial destructor,
3900      nothing has to be done.  */
3901   if (!initp
3902       && TYPE_HAS_TRIVIAL_DESTRUCTOR (TREE_TYPE (decl)))
3903     return;
3904
3905   /* Trick the compiler into thinking we are at the file and line
3906      where DECL was declared so that error-messages make sense, and so
3907      that the debugger will show somewhat sensible file and line
3908      information.  */
3909   input_location = DECL_SOURCE_LOCATION (decl);
3910
3911   /* Make sure temporary variables in the initialiser all have
3912      their DECL_CONTEXT() set to a value different from NULL_TREE.
3913      This can happen when global variables initializers are built.
3914      In that case, the DECL_CONTEXT() of the global variables _AND_ of all
3915      the temporary variables that might have been generated in the
3916      accompanying initializers is NULL_TREE, meaning the variables have been
3917      declared in the global namespace.
3918      What we want to do here is to fix that and make sure the DECL_CONTEXT()
3919      of the temporaries are set to the current function decl.  */
3920   cp_walk_tree_without_duplicates (&init,
3921                                    fix_temporary_vars_context_r,
3922                                    NULL);
3923
3924   /* Because of:
3925
3926        [class.access.spec]
3927
3928        Access control for implicit calls to the constructors,
3929        the conversion functions, or the destructor called to
3930        create and destroy a static data member is performed as
3931        if these calls appeared in the scope of the member's
3932        class.
3933
3934      we pretend we are in a static member function of the class of
3935      which the DECL is a member.  */
3936   if (member_p (decl))
3937     {
3938       DECL_CONTEXT (current_function_decl) = DECL_CONTEXT (decl);
3939       DECL_STATIC_FUNCTION_P (current_function_decl) = 1;
3940     }
3941
3942   /* Assume we don't need a guard.  */
3943   guard = NULL_TREE;
3944   /* We need a guard if this is an object with external linkage that
3945      might be initialized in more than one place.  (For example, a
3946      static data member of a template, when the data member requires
3947      construction.)  */
3948   if (NEEDS_GUARD_P (decl))
3949     {
3950       tree guard_cond;
3951
3952       guard = get_guard (decl);
3953
3954       /* When using __cxa_atexit, we just check the GUARD as we would
3955          for a local static.  */
3956       if (flag_use_cxa_atexit)
3957         {
3958           /* When using __cxa_atexit, we never try to destroy
3959              anything from a static destructor.  */
3960           gcc_assert (initp);
3961           guard_cond = get_guard_cond (guard, false);
3962         }
3963       /* If we don't have __cxa_atexit, then we will be running
3964          destructors from .fini sections, or their equivalents.  So,
3965          we need to know how many times we've tried to initialize this
3966          object.  We do initializations only if the GUARD is zero,
3967          i.e., if we are the first to initialize the variable.  We do
3968          destructions only if the GUARD is one, i.e., if we are the
3969          last to destroy the variable.  */
3970       else if (initp)
3971         guard_cond
3972           = cp_build_binary_op (input_location,
3973                                 EQ_EXPR,
3974                                 cp_build_unary_op (PREINCREMENT_EXPR,
3975                                                    guard,
3976                                                    /*noconvert=*/true,
3977                                                    tf_warning_or_error),
3978                                 integer_one_node,
3979                                 tf_warning_or_error);
3980       else
3981         guard_cond
3982           = cp_build_binary_op (input_location,
3983                                 EQ_EXPR,
3984                                 cp_build_unary_op (PREDECREMENT_EXPR,
3985                                                    guard,
3986                                                    /*noconvert=*/true,
3987                                                    tf_warning_or_error),
3988                                 integer_zero_node,
3989                                 tf_warning_or_error);
3990
3991       guard_if_stmt = begin_if_stmt ();
3992       finish_if_stmt_cond (guard_cond, guard_if_stmt);
3993     }
3994
3995
3996   /* If we're using __cxa_atexit, we have not already set the GUARD,
3997      so we must do so now.  */
3998   if (guard && initp && flag_use_cxa_atexit)
3999     finish_expr_stmt (set_guard (guard));
4000
4001   /* Perform the initialization or destruction.  */
4002   if (initp)
4003     {
4004       if (init)
4005         {
4006           finish_expr_stmt (init);
4007           if (sanitize_flags_p (SANITIZE_ADDRESS, decl))
4008             {
4009               varpool_node *vnode = varpool_node::get (decl);
4010               if (vnode)
4011                 vnode->dynamically_initialized = 1;
4012             }
4013         }
4014
4015       /* If we're using __cxa_atexit, register a function that calls the
4016          destructor for the object.  */
4017       if (flag_use_cxa_atexit)
4018         finish_expr_stmt (register_dtor_fn (decl));
4019     }
4020   else
4021     finish_expr_stmt (build_cleanup (decl));
4022
4023   /* Finish the guard if-stmt, if necessary.  */
4024   if (guard)
4025     {
4026       finish_then_clause (guard_if_stmt);
4027       finish_if_stmt (guard_if_stmt);
4028     }
4029
4030   /* Now that we're done with DECL we don't need to pretend to be a
4031      member of its class any longer.  */
4032   DECL_CONTEXT (current_function_decl) = NULL_TREE;
4033   DECL_STATIC_FUNCTION_P (current_function_decl) = 0;
4034 }
4035
4036 /* Generate code to do the initialization or destruction of the decls in VARS,
4037    a TREE_LIST of VAR_DECL with static storage duration.
4038    Whether initialization or destruction is performed is specified by INITP.  */
4039
4040 static void
4041 do_static_initialization_or_destruction (tree vars, bool initp)
4042 {
4043   tree node, init_if_stmt, cond;
4044
4045   /* Build the outer if-stmt to check for initialization or destruction.  */
4046   init_if_stmt = begin_if_stmt ();
4047   cond = initp ? integer_one_node : integer_zero_node;
4048   cond = cp_build_binary_op (input_location,
4049                              EQ_EXPR,
4050                              initialize_p_decl,
4051                              cond,
4052                              tf_warning_or_error);
4053   finish_if_stmt_cond (cond, init_if_stmt);
4054
4055   /* To make sure dynamic construction doesn't access globals from other
4056      compilation units where they might not be yet constructed, for
4057      -fsanitize=address insert __asan_before_dynamic_init call that
4058      prevents access to either all global variables that need construction
4059      in other compilation units, or at least those that haven't been
4060      initialized yet.  Variables that need dynamic construction in
4061      the current compilation unit are kept accessible.  */
4062   if (initp && (flag_sanitize & SANITIZE_ADDRESS))
4063     finish_expr_stmt (asan_dynamic_init_call (/*after_p=*/false));
4064
4065   node = vars;
4066   do {
4067     tree decl = TREE_VALUE (node);
4068     tree priority_if_stmt;
4069     int priority;
4070     priority_info pi;
4071
4072     /* If we don't need a destructor, there's nothing to do.  Avoid
4073        creating a possibly empty if-stmt.  */
4074     if (!initp && TYPE_HAS_TRIVIAL_DESTRUCTOR (TREE_TYPE (decl)))
4075       {
4076         node = TREE_CHAIN (node);
4077         continue;
4078       }
4079
4080     /* Remember that we had an initialization or finalization at this
4081        priority.  */
4082     priority = DECL_EFFECTIVE_INIT_PRIORITY (decl);
4083     pi = get_priority_info (priority);
4084     if (initp)
4085       pi->initializations_p = 1;
4086     else
4087       pi->destructions_p = 1;
4088
4089     /* Conditionalize this initialization on being in the right priority
4090        and being initializing/finalizing appropriately.  */
4091     priority_if_stmt = begin_if_stmt ();
4092     cond = cp_build_binary_op (input_location,
4093                                EQ_EXPR,
4094                                priority_decl,
4095                                build_int_cst (NULL_TREE, priority),
4096                                tf_warning_or_error);
4097     finish_if_stmt_cond (cond, priority_if_stmt);
4098
4099     /* Process initializers with same priority.  */
4100     for (; node
4101            && DECL_EFFECTIVE_INIT_PRIORITY (TREE_VALUE (node)) == priority;
4102          node = TREE_CHAIN (node))
4103       /* Do one initialization or destruction.  */
4104       one_static_initialization_or_destruction (TREE_VALUE (node),
4105                                                 TREE_PURPOSE (node), initp);
4106
4107     /* Finish up the priority if-stmt body.  */
4108     finish_then_clause (priority_if_stmt);
4109     finish_if_stmt (priority_if_stmt);
4110
4111   } while (node);
4112
4113   /* Revert what __asan_before_dynamic_init did by calling
4114      __asan_after_dynamic_init.  */
4115   if (initp && (flag_sanitize & SANITIZE_ADDRESS))
4116     finish_expr_stmt (asan_dynamic_init_call (/*after_p=*/true));
4117
4118   /* Finish up the init/destruct if-stmt body.  */
4119   finish_then_clause (init_if_stmt);
4120   finish_if_stmt (init_if_stmt);
4121 }
4122
4123 /* VARS is a list of variables with static storage duration which may
4124    need initialization and/or finalization.  Remove those variables
4125    that don't really need to be initialized or finalized, and return
4126    the resulting list.  The order in which the variables appear in
4127    VARS is in reverse order of the order in which they should actually
4128    be initialized.  The list we return is in the unreversed order;
4129    i.e., the first variable should be initialized first.  */
4130
4131 static tree
4132 prune_vars_needing_no_initialization (tree *vars)
4133 {
4134   tree *var = vars;
4135   tree result = NULL_TREE;
4136
4137   while (*var)
4138     {
4139       tree t = *var;
4140       tree decl = TREE_VALUE (t);
4141       tree init = TREE_PURPOSE (t);
4142
4143       /* Deal gracefully with error.  */
4144       if (error_operand_p (decl))
4145         {
4146           var = &TREE_CHAIN (t);
4147           continue;
4148         }
4149
4150       /* The only things that can be initialized are variables.  */
4151       gcc_assert (VAR_P (decl));
4152
4153       /* If this object is not defined, we don't need to do anything
4154          here.  */
4155       if (DECL_EXTERNAL (decl))
4156         {
4157           var = &TREE_CHAIN (t);
4158           continue;
4159         }
4160
4161       /* Also, if the initializer already contains errors, we can bail
4162          out now.  */
4163       if (init && TREE_CODE (init) == TREE_LIST
4164           && value_member (error_mark_node, init))
4165         {
4166           var = &TREE_CHAIN (t);
4167           continue;
4168         }
4169
4170       /* This variable is going to need initialization and/or
4171          finalization, so we add it to the list.  */
4172       *var = TREE_CHAIN (t);
4173       TREE_CHAIN (t) = result;
4174       result = t;
4175     }
4176
4177   return result;
4178 }
4179
4180 /* Make sure we have told the back end about all the variables in
4181    VARS.  */
4182
4183 static void
4184 write_out_vars (tree vars)
4185 {
4186   tree v;
4187
4188   for (v = vars; v; v = TREE_CHAIN (v))
4189     {
4190       tree var = TREE_VALUE (v);
4191       if (!var_finalized_p (var))
4192         {
4193           import_export_decl (var);
4194           rest_of_decl_compilation (var, 1, 1);
4195         }
4196     }
4197 }
4198
4199 /* Generate a static constructor (if CONSTRUCTOR_P) or destructor
4200    (otherwise) that will initialize all global objects with static
4201    storage duration having the indicated PRIORITY.  */
4202
4203 static void
4204 generate_ctor_or_dtor_function (bool constructor_p, int priority,
4205                                 location_t *locus)
4206 {
4207   char function_key;
4208   tree fndecl;
4209   tree body;
4210   size_t i;
4211
4212   input_location = *locus;
4213   /* ??? */
4214   /* Was: locus->line++; */
4215
4216   /* We use `I' to indicate initialization and `D' to indicate
4217      destruction.  */
4218   function_key = constructor_p ? 'I' : 'D';
4219
4220   /* We emit the function lazily, to avoid generating empty
4221      global constructors and destructors.  */
4222   body = NULL_TREE;
4223
4224   /* For Objective-C++, we may need to initialize metadata found in this module.
4225      This must be done _before_ any other static initializations.  */
4226   if (c_dialect_objc () && (priority == DEFAULT_INIT_PRIORITY)
4227       && constructor_p && objc_static_init_needed_p ())
4228     {
4229       body = start_objects (function_key, priority);
4230       objc_generate_static_init_call (NULL_TREE);
4231     }
4232
4233   /* Call the static storage duration function with appropriate
4234      arguments.  */
4235   FOR_EACH_VEC_SAFE_ELT (ssdf_decls, i, fndecl)
4236     {
4237       /* Calls to pure or const functions will expand to nothing.  */
4238       if (! (flags_from_decl_or_type (fndecl) & (ECF_CONST | ECF_PURE)))
4239         {
4240           tree call;
4241
4242           if (! body)
4243             body = start_objects (function_key, priority);
4244
4245           call = cp_build_function_call_nary (fndecl, tf_warning_or_error,
4246                                               build_int_cst (NULL_TREE,
4247                                                              constructor_p),
4248                                               build_int_cst (NULL_TREE,
4249                                                              priority),
4250                                               NULL_TREE);
4251           finish_expr_stmt (call);
4252         }
4253     }
4254
4255   /* Close out the function.  */
4256   if (body)
4257     finish_objects (function_key, priority, body);
4258 }
4259
4260 /* Generate constructor and destructor functions for the priority
4261    indicated by N.  */
4262
4263 static int
4264 generate_ctor_and_dtor_functions_for_priority (splay_tree_node n, void * data)
4265 {
4266   location_t *locus = (location_t *) data;
4267   int priority = (int) n->key;
4268   priority_info pi = (priority_info) n->value;
4269
4270   /* Generate the functions themselves, but only if they are really
4271      needed.  */
4272   if (pi->initializations_p)
4273     generate_ctor_or_dtor_function (/*constructor_p=*/true, priority, locus);
4274   if (pi->destructions_p)
4275     generate_ctor_or_dtor_function (/*constructor_p=*/false, priority, locus);
4276
4277   /* Keep iterating.  */
4278   return 0;
4279 }
4280
4281 /* Return C++ property of T, based on given operation OP.  */
4282
4283 static int
4284 cpp_check (tree t, cpp_operation op)
4285 {
4286   switch (op)
4287     {
4288       case HAS_DEPENDENT_TEMPLATE_ARGS:
4289         {
4290           tree ti = CLASSTYPE_TEMPLATE_INFO (t);
4291           if (!ti)
4292             return 0;
4293           ++processing_template_decl;
4294           const bool dep = any_dependent_template_arguments_p (TI_ARGS (ti));
4295           --processing_template_decl;
4296           return dep;
4297         }
4298       case IS_ABSTRACT:
4299         return DECL_PURE_VIRTUAL_P (t);
4300       case IS_ASSIGNMENT_OPERATOR:
4301         return DECL_ASSIGNMENT_OPERATOR_P (t);
4302       case IS_CONSTRUCTOR:
4303         return DECL_CONSTRUCTOR_P (t);
4304       case IS_DESTRUCTOR:
4305         return DECL_DESTRUCTOR_P (t);
4306       case IS_COPY_CONSTRUCTOR:
4307         return DECL_COPY_CONSTRUCTOR_P (t);
4308       case IS_MOVE_CONSTRUCTOR:
4309         return DECL_MOVE_CONSTRUCTOR_P (t);
4310       case IS_TEMPLATE:
4311         return TREE_CODE (t) == TEMPLATE_DECL;
4312       case IS_TRIVIAL:
4313         return trivial_type_p (t);
4314       default:
4315         return 0;
4316     }
4317 }
4318
4319 /* Collect source file references recursively, starting from NAMESPC.  */
4320
4321 static void
4322 collect_source_refs (tree namespc)
4323 {
4324   /* Iterate over names in this name space.  */
4325   for (tree t = NAMESPACE_LEVEL (namespc)->names; t; t = TREE_CHAIN (t))
4326     if (DECL_IS_BUILTIN (t))
4327       ;
4328     else if (TREE_CODE (t) == NAMESPACE_DECL && !DECL_NAMESPACE_ALIAS (t))
4329       collect_source_refs (t);
4330     else
4331       collect_source_ref (DECL_SOURCE_FILE (t));
4332 }
4333
4334 /* Collect decls relevant to SOURCE_FILE from all namespaces recursively,
4335    starting from NAMESPC.  */
4336
4337 static void
4338 collect_ada_namespace (tree namespc, const char *source_file)
4339 {
4340   tree decl = NAMESPACE_LEVEL (namespc)->names;
4341
4342   /* Collect decls from this namespace.  This will skip
4343      NAMESPACE_DECLs (both aliases and regular, it cannot tell).  */
4344   collect_ada_nodes (decl, source_file);
4345
4346   /* Now scan for namespace children, and dump them.  */
4347   for (; decl; decl = TREE_CHAIN (decl))
4348     if (TREE_CODE (decl) == NAMESPACE_DECL && !DECL_NAMESPACE_ALIAS (decl))
4349       collect_ada_namespace (decl, source_file);
4350 }
4351
4352 /* Returns true iff there is a definition available for variable or
4353    function DECL.  */
4354
4355 bool
4356 decl_defined_p (tree decl)
4357 {
4358   if (TREE_CODE (decl) == FUNCTION_DECL)
4359     return (DECL_INITIAL (decl) != NULL_TREE
4360             /* A pending instantiation of a friend temploid is defined.  */
4361             || (DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (decl)
4362                 && DECL_INITIAL (DECL_TEMPLATE_RESULT
4363                                  (DECL_TI_TEMPLATE (decl)))));
4364   else
4365     {
4366       gcc_assert (VAR_P (decl));
4367       return !DECL_EXTERNAL (decl);
4368     }
4369 }
4370
4371 /* Nonzero for a VAR_DECL whose value can be used in a constant expression.
4372
4373       [expr.const]
4374
4375       An integral constant-expression can only involve ... const
4376       variables of integral or enumeration types initialized with
4377       constant expressions ...
4378
4379       C++0x also allows constexpr variables and temporaries initialized
4380       with constant expressions.  We handle the former here, but the latter
4381       are just folded away in cxx_eval_constant_expression.
4382
4383    The standard does not require that the expression be non-volatile.
4384    G++ implements the proposed correction in DR 457.  */
4385
4386 bool
4387 decl_constant_var_p (tree decl)
4388 {
4389   if (!decl_maybe_constant_var_p (decl))
4390     return false;
4391
4392   /* We don't know if a template static data member is initialized with
4393      a constant expression until we instantiate its initializer.  Even
4394      in the case of a constexpr variable, we can't treat it as a
4395      constant until its initializer is complete in case it's used in
4396      its own initializer.  */
4397   maybe_instantiate_decl (decl);
4398   return DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl);
4399 }
4400
4401 /* Returns true if DECL could be a symbolic constant variable, depending on
4402    its initializer.  */
4403
4404 bool
4405 decl_maybe_constant_var_p (tree decl)
4406 {
4407   tree type = TREE_TYPE (decl);
4408   if (!VAR_P (decl))
4409     return false;
4410   if (DECL_DECLARED_CONSTEXPR_P (decl) && !TREE_THIS_VOLATILE (decl))
4411     return true;
4412   if (DECL_HAS_VALUE_EXPR_P (decl))
4413     /* A proxy isn't constant.  */
4414     return false;
4415   if (TYPE_REF_P (type))
4416     /* References can be constant.  */;
4417   else if (CP_TYPE_CONST_NON_VOLATILE_P (type)
4418            && INTEGRAL_OR_ENUMERATION_TYPE_P (type))
4419     /* And const integers.  */;
4420   else
4421     return false;
4422
4423   if (DECL_INITIAL (decl)
4424       && !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl))
4425     /* We know the initializer, and it isn't constant.  */
4426     return false;
4427   else
4428     return true;
4429 }
4430
4431 /* Complain that DECL uses a type with no linkage.  In C++98 mode this is
4432    called from grokfndecl and grokvardecl; in all modes it is called from
4433    cp_write_global_declarations.  */
4434
4435 void
4436 no_linkage_error (tree decl)
4437 {
4438   if (cxx_dialect >= cxx11
4439       && (decl_defined_p (decl)
4440           /* Treat templates which limit_bad_template_recursion decided
4441              not to instantiate as if they were defined.  */
4442           || (errorcount + sorrycount > 0
4443               && DECL_LANG_SPECIFIC (decl)
4444               && DECL_TEMPLATE_INFO (decl)
4445               && TREE_NO_WARNING (decl))))
4446     /* In C++11 it's ok if the decl is defined.  */
4447     return;
4448   tree t = no_linkage_check (TREE_TYPE (decl), /*relaxed_p=*/false);
4449   if (t == NULL_TREE)
4450     /* The type that got us on no_linkage_decls must have gotten a name for
4451        linkage purposes.  */;
4452   else if (CLASS_TYPE_P (t) && TYPE_BEING_DEFINED (t))
4453     /* The type might end up having a typedef name for linkage purposes.  */
4454     vec_safe_push (no_linkage_decls, decl);
4455   else if (TYPE_UNNAMED_P (t))
4456     {
4457       bool d = false;
4458       auto_diagnostic_group grp;
4459       if (cxx_dialect >= cxx11)
4460         d = permerror (DECL_SOURCE_LOCATION (decl), "%q#D, declared using "
4461                        "unnamed type, is used but never defined", decl);
4462       else if (DECL_EXTERN_C_P (decl))
4463         /* Allow this; it's pretty common in C.  */;
4464       else if (VAR_P (decl))
4465         /* DRs 132, 319 and 389 seem to indicate types with
4466            no linkage can only be used to declare extern "C"
4467            entities.  Since it's not always an error in the
4468            ISO C++ 90 Standard, we only issue a warning.  */
4469         d = warning_at (DECL_SOURCE_LOCATION (decl), 0, "unnamed type "
4470                         "with no linkage used to declare variable %q#D with "
4471                         "linkage", decl);
4472       else
4473         d = permerror (DECL_SOURCE_LOCATION (decl), "unnamed type with no "
4474                        "linkage used to declare function %q#D with linkage",
4475                        decl);
4476       if (d && is_typedef_decl (TYPE_NAME (t)))
4477         inform (DECL_SOURCE_LOCATION (TYPE_NAME (t)), "%q#D does not refer "
4478                 "to the unqualified type, so it is not used for linkage",
4479                 TYPE_NAME (t));
4480     }
4481   else if (cxx_dialect >= cxx11)
4482     {
4483       if (VAR_P (decl) || !DECL_PURE_VIRTUAL_P (decl))
4484         permerror (DECL_SOURCE_LOCATION (decl),
4485                    "%q#D, declared using local type "
4486                    "%qT, is used but never defined", decl, t);
4487     }
4488   else if (VAR_P (decl))
4489     warning_at (DECL_SOURCE_LOCATION (decl), 0, "type %qT with no linkage "
4490                 "used to declare variable %q#D with linkage", t, decl);
4491   else
4492     permerror (DECL_SOURCE_LOCATION (decl), "type %qT with no linkage used "
4493                "to declare function %q#D with linkage", t, decl);
4494 }
4495
4496 /* Collect declarations from all namespaces relevant to SOURCE_FILE.  */
4497
4498 static void
4499 collect_all_refs (const char *source_file)
4500 {
4501   collect_ada_namespace (global_namespace, source_file);
4502 }
4503
4504 /* Clear DECL_EXTERNAL for NODE.  */
4505
4506 static bool
4507 clear_decl_external (struct cgraph_node *node, void * /*data*/)
4508 {
4509   DECL_EXTERNAL (node->decl) = 0;
4510   return false;
4511 }
4512
4513 /* Build up the function to run dynamic initializers for thread_local
4514    variables in this translation unit and alias the init functions for the
4515    individual variables to it.  */
4516
4517 static void
4518 handle_tls_init (void)
4519 {
4520   tree vars = prune_vars_needing_no_initialization (&tls_aggregates);
4521   if (vars == NULL_TREE)
4522     return;
4523
4524   location_t loc = DECL_SOURCE_LOCATION (TREE_VALUE (vars));
4525
4526   write_out_vars (vars);
4527
4528   tree guard = build_decl (loc, VAR_DECL, get_identifier ("__tls_guard"),
4529                            boolean_type_node);
4530   TREE_PUBLIC (guard) = false;
4531   TREE_STATIC (guard) = true;
4532   DECL_ARTIFICIAL (guard) = true;
4533   DECL_IGNORED_P (guard) = true;
4534   TREE_USED (guard) = true;
4535   CP_DECL_THREAD_LOCAL_P (guard) = true;
4536   set_decl_tls_model (guard, decl_default_tls_model (guard));
4537   pushdecl_top_level_and_finish (guard, NULL_TREE);
4538
4539   tree fn = get_local_tls_init_fn (loc);
4540   start_preparsed_function (fn, NULL_TREE, SF_PRE_PARSED);
4541   tree body = begin_function_body ();
4542   tree if_stmt = begin_if_stmt ();
4543   tree cond = cp_build_unary_op (TRUTH_NOT_EXPR, guard, false,
4544                                  tf_warning_or_error);
4545   finish_if_stmt_cond (cond, if_stmt);
4546   finish_expr_stmt (cp_build_modify_expr (loc, guard, NOP_EXPR,
4547                                           boolean_true_node,
4548                                           tf_warning_or_error));
4549   for (; vars; vars = TREE_CHAIN (vars))
4550     {
4551       tree var = TREE_VALUE (vars);
4552       tree init = TREE_PURPOSE (vars);
4553       one_static_initialization_or_destruction (var, init, true);
4554
4555       /* Output init aliases even with -fno-extern-tls-init.  */
4556       if (TARGET_SUPPORTS_ALIASES && TREE_PUBLIC (var))
4557         {
4558           tree single_init_fn = get_tls_init_fn (var);
4559           if (single_init_fn == NULL_TREE)
4560             continue;
4561           cgraph_node *alias
4562             = cgraph_node::get_create (fn)->create_same_body_alias
4563                 (single_init_fn, fn);
4564           gcc_assert (alias != NULL);
4565         }
4566     }
4567
4568   finish_then_clause (if_stmt);
4569   finish_if_stmt (if_stmt);
4570   finish_function_body (body);
4571   expand_or_defer_fn (finish_function (/*inline_p=*/false));
4572 }
4573
4574 /* We're at the end of compilation, so generate any mangling aliases that
4575    we've been saving up, if DECL is going to be output and ID2 isn't
4576    already taken by another declaration.  */
4577
4578 static void
4579 generate_mangling_alias (tree decl, tree id2)
4580 {
4581   struct cgraph_node *n = NULL;
4582
4583   if (TREE_CODE (decl) == FUNCTION_DECL)
4584     {
4585       n = cgraph_node::get (decl);
4586       if (!n)
4587         /* Don't create an alias to an unreferenced function.  */
4588         return;
4589     }
4590
4591   tree *slot
4592     = mangled_decls->find_slot_with_hash (id2, IDENTIFIER_HASH_VALUE (id2),
4593                                           INSERT);
4594
4595   /* If there's a declaration already using this mangled name,
4596      don't create a compatibility alias that conflicts.  */
4597   if (*slot)
4598     return;
4599
4600   tree alias = make_alias_for (decl, id2);
4601   *slot = alias;
4602
4603   DECL_IGNORED_P (alias) = 1;
4604   TREE_PUBLIC (alias) = TREE_PUBLIC (decl);
4605   DECL_VISIBILITY (alias) = DECL_VISIBILITY (decl);
4606   if (vague_linkage_p (decl))
4607     DECL_WEAK (alias) = 1;
4608
4609   if (n)
4610     n->create_same_body_alias (alias, decl);
4611   else
4612     varpool_node::create_extra_name_alias (alias, decl);
4613 }
4614
4615 /* Note that we might want to emit an alias with the symbol ID2 for DECL at
4616    the end of translation, for compatibility across bugs in the mangling
4617    implementation.  */
4618
4619 void
4620 note_mangling_alias (tree decl, tree id2)
4621 {
4622   if (TARGET_SUPPORTS_ALIASES)
4623     {
4624       if (!defer_mangling_aliases)
4625         generate_mangling_alias (decl, id2);
4626       else
4627         {
4628           vec_safe_push (mangling_aliases, decl);
4629           vec_safe_push (mangling_aliases, id2);
4630         }
4631     }
4632 }
4633
4634 /* Emit all mangling aliases that were deferred up to this point.  */
4635
4636 void
4637 generate_mangling_aliases ()
4638 {
4639   while (!vec_safe_is_empty (mangling_aliases))
4640     {
4641       tree id2 = mangling_aliases->pop();
4642       tree decl = mangling_aliases->pop();
4643       generate_mangling_alias (decl, id2);
4644     }
4645   defer_mangling_aliases = false;
4646 }
4647
4648 /* Record a mangling of DECL, whose DECL_ASSEMBLER_NAME has just been
4649    set.  NEED_WARNING is true if we must warn about collisions.  We do
4650    this to spot changes in mangling that may require compatibility
4651    aliases.  */
4652
4653 void
4654 record_mangling (tree decl, bool need_warning)
4655 {
4656   if (!mangled_decls)
4657     mangled_decls = hash_table<mangled_decl_hash>::create_ggc (499);
4658
4659   gcc_checking_assert (DECL_ASSEMBLER_NAME_SET_P (decl));
4660   tree id = DECL_ASSEMBLER_NAME_RAW (decl);
4661   tree *slot
4662     = mangled_decls->find_slot_with_hash (id, IDENTIFIER_HASH_VALUE (id),
4663                                           INSERT);
4664
4665   /* If this is already an alias, remove the alias, because the real
4666      decl takes precedence.  */
4667   if (*slot && DECL_ARTIFICIAL (*slot) && DECL_IGNORED_P (*slot))
4668     if (symtab_node *n = symtab_node::get (*slot))
4669       if (n->cpp_implicit_alias)
4670         {
4671           n->remove ();
4672           *slot = NULL_TREE;
4673         }
4674
4675   if (!*slot)
4676     *slot = decl;
4677   else if (need_warning)
4678     {
4679       error_at (DECL_SOURCE_LOCATION (decl),
4680                 "mangling of %q#D as %qE conflicts with a previous mangle",
4681                 decl, id);
4682       inform (DECL_SOURCE_LOCATION (*slot),
4683               "previous mangling %q#D", *slot);
4684       inform (DECL_SOURCE_LOCATION (decl),
4685               "a later %<-fabi-version=%> (or =0)"
4686               " avoids this error with a change in mangling");
4687       *slot = decl;
4688     }
4689 }
4690
4691 /* The mangled name of DECL is being forcibly changed to NAME.  Remove
4692    any existing knowledge of DECL's mangled name meaning DECL.  */
4693
4694 void
4695 overwrite_mangling (tree decl, tree name)
4696 {
4697   if (tree id = DECL_ASSEMBLER_NAME_RAW (decl))
4698     if ((TREE_CODE (decl) == VAR_DECL
4699          || TREE_CODE (decl) == FUNCTION_DECL)
4700         && mangled_decls)
4701       if (tree *slot
4702           = mangled_decls->find_slot_with_hash (id, IDENTIFIER_HASH_VALUE (id),
4703                                                 NO_INSERT))
4704         if (*slot == decl)
4705           {
4706             mangled_decls->clear_slot (slot);
4707
4708             /* If this is an alias, remove it from the symbol table.  */
4709             if (DECL_ARTIFICIAL (decl) && DECL_IGNORED_P (decl))
4710               if (symtab_node *n = symtab_node::get (decl))
4711                 if (n->cpp_implicit_alias)
4712                   n->remove ();
4713           }
4714
4715   DECL_ASSEMBLER_NAME_RAW (decl) = name;
4716 }
4717
4718 /* The entire file is now complete.  If requested, dump everything
4719    to a file.  */
4720
4721 static void
4722 dump_tu (void)
4723 {
4724   dump_flags_t flags;
4725   if (FILE *stream = dump_begin (raw_dump_id, &flags))
4726     {
4727       dump_node (global_namespace, flags & ~TDF_SLIM, stream);
4728       dump_end (raw_dump_id, stream);
4729     }
4730 }
4731
4732 static location_t locus_at_end_of_parsing;
4733
4734 /* Check the deallocation functions for CODE to see if we want to warn that
4735    only one was defined.  */
4736
4737 static void
4738 maybe_warn_sized_delete (enum tree_code code)
4739 {
4740   tree sized = NULL_TREE;
4741   tree unsized = NULL_TREE;
4742
4743   for (ovl_iterator iter (get_global_binding (ovl_op_identifier (false, code)));
4744        iter; ++iter)
4745     {
4746       tree fn = *iter;
4747       /* We're only interested in usual deallocation functions.  */
4748       if (!usual_deallocation_fn_p (fn))
4749         continue;
4750       if (FUNCTION_ARG_CHAIN (fn) == void_list_node)
4751         unsized = fn;
4752       else
4753         sized = fn;
4754     }
4755   if (DECL_INITIAL (unsized) && !DECL_INITIAL (sized))
4756     warning_at (DECL_SOURCE_LOCATION (unsized), OPT_Wsized_deallocation,
4757                 "the program should also define %qD", sized);
4758   else if (!DECL_INITIAL (unsized) && DECL_INITIAL (sized))
4759     warning_at (DECL_SOURCE_LOCATION (sized), OPT_Wsized_deallocation,
4760                 "the program should also define %qD", unsized);
4761 }
4762
4763 /* Check the global deallocation functions to see if we want to warn about
4764    defining unsized without sized (or vice versa).  */
4765
4766 static void
4767 maybe_warn_sized_delete ()
4768 {
4769   if (!flag_sized_deallocation || !warn_sized_deallocation)
4770     return;
4771   maybe_warn_sized_delete (DELETE_EXPR);
4772   maybe_warn_sized_delete (VEC_DELETE_EXPR);
4773 }
4774
4775 /* Earlier we left PTRMEM_CST in variable initializers alone so that we could
4776    look them up when evaluating non-type template parameters.  Now we need to
4777    lower them to something the back end can understand.  */
4778
4779 static void
4780 lower_var_init ()
4781 {
4782   varpool_node *node;
4783   FOR_EACH_VARIABLE (node)
4784     {
4785       tree d = node->decl;
4786       if (tree init = DECL_INITIAL (d))
4787         DECL_INITIAL (d) = cplus_expand_constant (init);
4788     }
4789 }
4790
4791 /* This routine is called at the end of compilation.
4792    Its job is to create all the code needed to initialize and
4793    destroy the global aggregates.  We do the destruction
4794    first, since that way we only need to reverse the decls once.  */
4795
4796 void
4797 c_parse_final_cleanups (void)
4798 {
4799   tree vars;
4800   bool reconsider;
4801   size_t i;
4802   unsigned ssdf_count = 0;
4803   int retries = 0;
4804   tree decl;
4805
4806   locus_at_end_of_parsing = input_location;
4807   at_eof = 1;
4808
4809   /* Bad parse errors.  Just forget about it.  */
4810   if (! global_bindings_p () || current_class_type
4811       || !vec_safe_is_empty (decl_namespace_list))
4812     return;
4813
4814   /* This is the point to write out a PCH if we're doing that.
4815      In that case we do not want to do anything else.  */
4816   if (pch_file)
4817     {
4818       /* Mangle all symbols at PCH creation time.  */
4819       symtab_node *node;
4820       FOR_EACH_SYMBOL (node)
4821         if (! is_a <varpool_node *> (node)
4822             || ! DECL_HARD_REGISTER (node->decl))
4823           DECL_ASSEMBLER_NAME (node->decl);
4824       c_common_write_pch ();
4825       dump_tu ();
4826       /* Ensure even the callers don't try to finalize the CU.  */
4827       flag_syntax_only = 1;
4828       return;
4829     }
4830
4831   timevar_stop (TV_PHASE_PARSING);
4832   timevar_start (TV_PHASE_DEFERRED);
4833
4834   symtab->process_same_body_aliases ();
4835
4836   /* Handle -fdump-ada-spec[-slim] */
4837   if (flag_dump_ada_spec || flag_dump_ada_spec_slim)
4838     {
4839       collect_source_ref (main_input_filename);
4840       if (!flag_dump_ada_spec_slim)
4841         collect_source_refs (global_namespace);
4842
4843       dump_ada_specs (collect_all_refs, cpp_check);
4844     }
4845
4846   /* FIXME - huh?  was  input_line -= 1;*/
4847
4848   /* We now have to write out all the stuff we put off writing out.
4849      These include:
4850
4851        o Template specializations that we have not yet instantiated,
4852          but which are needed.
4853        o Initialization and destruction for non-local objects with
4854          static storage duration.  (Local objects with static storage
4855          duration are initialized when their scope is first entered,
4856          and are cleaned up via atexit.)
4857        o Virtual function tables.
4858
4859      All of these may cause others to be needed.  For example,
4860      instantiating one function may cause another to be needed, and
4861      generating the initializer for an object may cause templates to be
4862      instantiated, etc., etc.  */
4863
4864   emit_support_tinfos ();
4865
4866   do
4867     {
4868       tree t;
4869       tree decl;
4870
4871       reconsider = false;
4872
4873       /* If there are templates that we've put off instantiating, do
4874          them now.  */
4875       instantiate_pending_templates (retries);
4876       ggc_collect ();
4877
4878       /* Write out virtual tables as required.  Writing out the
4879          virtual table for a template class may cause the
4880          instantiation of members of that class.  If we write out
4881          vtables then we remove the class from our list so we don't
4882          have to look at it again.  */
4883       for (i = keyed_classes->length ();
4884            keyed_classes->iterate (--i, &t);)
4885         if (maybe_emit_vtables (t))
4886           {
4887             reconsider = true;
4888             keyed_classes->unordered_remove (i);
4889           }
4890       /* The input_location may have been changed during marking of
4891          vtable entries.  */
4892       input_location = locus_at_end_of_parsing;
4893
4894       /* Write out needed type info variables.  We have to be careful
4895          looping through unemitted decls, because emit_tinfo_decl may
4896          cause other variables to be needed. New elements will be
4897          appended, and we remove from the vector those that actually
4898          get emitted.  */
4899       for (i = unemitted_tinfo_decls->length ();
4900            unemitted_tinfo_decls->iterate (--i, &t);)
4901         if (emit_tinfo_decl (t))
4902           {
4903             reconsider = true;
4904             unemitted_tinfo_decls->unordered_remove (i);
4905           }
4906
4907       /* The list of objects with static storage duration is built up
4908          in reverse order.  We clear STATIC_AGGREGATES so that any new
4909          aggregates added during the initialization of these will be
4910          initialized in the correct order when we next come around the
4911          loop.  */
4912       vars = prune_vars_needing_no_initialization (&static_aggregates);
4913
4914       if (vars)
4915         {
4916           /* We need to start a new initialization function each time
4917              through the loop.  That's because we need to know which
4918              vtables have been referenced, and TREE_SYMBOL_REFERENCED
4919              isn't computed until a function is finished, and written
4920              out.  That's a deficiency in the back end.  When this is
4921              fixed, these initialization functions could all become
4922              inline, with resulting performance improvements.  */
4923           tree ssdf_body;
4924
4925           /* Make sure the back end knows about all the variables.  */
4926           write_out_vars (vars);
4927
4928           /* Set the line and file, so that it is obviously not from
4929              the source file.  */
4930           input_location = locus_at_end_of_parsing;
4931           ssdf_body = start_static_storage_duration_function (ssdf_count);
4932
4933           /* First generate code to do all the initializations.  */
4934           if (vars)
4935             do_static_initialization_or_destruction (vars, /*initp=*/true);
4936
4937           /* Then, generate code to do all the destructions.  Do these
4938              in reverse order so that the most recently constructed
4939              variable is the first destroyed.  If we're using
4940              __cxa_atexit, then we don't need to do this; functions
4941              were registered at initialization time to destroy the
4942              local statics.  */
4943           if (!flag_use_cxa_atexit && vars)
4944             {
4945               vars = nreverse (vars);
4946               do_static_initialization_or_destruction (vars, /*initp=*/false);
4947             }
4948           else
4949             vars = NULL_TREE;
4950
4951           /* Finish up the static storage duration function for this
4952              round.  */
4953           input_location = locus_at_end_of_parsing;
4954           finish_static_storage_duration_function (ssdf_body);
4955
4956           /* All those initializations and finalizations might cause
4957              us to need more inline functions, more template
4958              instantiations, etc.  */
4959           reconsider = true;
4960           ssdf_count++;
4961           /* ??? was:  locus_at_end_of_parsing.line++; */
4962         }
4963
4964       /* Now do the same for thread_local variables.  */
4965       handle_tls_init ();
4966
4967       /* Go through the set of inline functions whose bodies have not
4968          been emitted yet.  If out-of-line copies of these functions
4969          are required, emit them.  */
4970       FOR_EACH_VEC_SAFE_ELT (deferred_fns, i, decl)
4971         {
4972           /* Does it need synthesizing?  */
4973           if (DECL_DEFAULTED_FN (decl) && ! DECL_INITIAL (decl)
4974               && (! DECL_REALLY_EXTERN (decl) || possibly_inlined_p (decl)))
4975             {
4976               /* Even though we're already at the top-level, we push
4977                  there again.  That way, when we pop back a few lines
4978                  hence, all of our state is restored.  Otherwise,
4979                  finish_function doesn't clean things up, and we end
4980                  up with CURRENT_FUNCTION_DECL set.  */
4981               push_to_top_level ();
4982               /* The decl's location will mark where it was first
4983                  needed.  Save that so synthesize method can indicate
4984                  where it was needed from, in case of error  */
4985               input_location = DECL_SOURCE_LOCATION (decl);
4986               synthesize_method (decl);
4987               pop_from_top_level ();
4988               reconsider = true;
4989             }
4990
4991           if (!DECL_INITIAL (decl) && decl_tls_wrapper_p (decl))
4992             generate_tls_wrapper (decl);
4993
4994           if (!DECL_SAVED_TREE (decl))
4995             continue;
4996
4997           cgraph_node *node = cgraph_node::get_create (decl);
4998
4999           /* We lie to the back end, pretending that some functions
5000              are not defined when they really are.  This keeps these
5001              functions from being put out unnecessarily.  But, we must
5002              stop lying when the functions are referenced, or if they
5003              are not comdat since they need to be put out now.  If
5004              DECL_INTERFACE_KNOWN, then we have already set
5005              DECL_EXTERNAL appropriately, so there's no need to check
5006              again, and we do not want to clear DECL_EXTERNAL if a
5007              previous call to import_export_decl set it.
5008
5009              This is done in a separate for cycle, because if some
5010              deferred function is contained in another deferred
5011              function later in deferred_fns varray,
5012              rest_of_compilation would skip this function and we
5013              really cannot expand the same function twice.  */
5014           import_export_decl (decl);
5015           if (DECL_NOT_REALLY_EXTERN (decl)
5016               && DECL_INITIAL (decl)
5017               && decl_needed_p (decl))
5018             {
5019               if (node->cpp_implicit_alias)
5020                 node = node->get_alias_target ();
5021
5022               node->call_for_symbol_thunks_and_aliases (clear_decl_external,
5023                                                       NULL, true);
5024               /* If we mark !DECL_EXTERNAL one of the symbols in some comdat
5025                  group, we need to mark all symbols in the same comdat group
5026                  that way.  */
5027               if (node->same_comdat_group)
5028                 for (cgraph_node *next
5029                        = dyn_cast<cgraph_node *> (node->same_comdat_group);
5030                      next != node;
5031                      next = dyn_cast<cgraph_node *> (next->same_comdat_group))
5032                   next->call_for_symbol_thunks_and_aliases (clear_decl_external,
5033                                                           NULL, true);
5034             }
5035
5036           /* If we're going to need to write this function out, and
5037              there's already a body for it, create RTL for it now.
5038              (There might be no body if this is a method we haven't
5039              gotten around to synthesizing yet.)  */
5040           if (!DECL_EXTERNAL (decl)
5041               && decl_needed_p (decl)
5042               && !TREE_ASM_WRITTEN (decl)
5043               && !node->definition)
5044             {
5045               /* We will output the function; no longer consider it in this
5046                  loop.  */
5047               DECL_DEFER_OUTPUT (decl) = 0;
5048               /* Generate RTL for this function now that we know we
5049                  need it.  */
5050               expand_or_defer_fn (decl);
5051               reconsider = true;
5052             }
5053         }
5054
5055       if (wrapup_namespace_globals ())
5056         reconsider = true;
5057
5058       /* Static data members are just like namespace-scope globals.  */
5059       FOR_EACH_VEC_SAFE_ELT (pending_statics, i, decl)
5060         {
5061           if (var_finalized_p (decl) || DECL_REALLY_EXTERN (decl)
5062               /* Don't write it out if we haven't seen a definition.  */
5063               || DECL_IN_AGGR_P (decl))
5064             continue;
5065           import_export_decl (decl);
5066           /* If this static data member is needed, provide it to the
5067              back end.  */
5068           if (DECL_NOT_REALLY_EXTERN (decl) && decl_needed_p (decl))
5069             DECL_EXTERNAL (decl) = 0;
5070         }
5071       if (vec_safe_length (pending_statics) != 0
5072           && wrapup_global_declarations (pending_statics->address (),
5073                                          pending_statics->length ()))
5074         reconsider = true;
5075
5076       retries++;
5077     }
5078   while (reconsider);
5079
5080   lower_var_init ();
5081
5082   generate_mangling_aliases ();
5083
5084   /* All used inline functions must have a definition at this point.  */
5085   FOR_EACH_VEC_SAFE_ELT (deferred_fns, i, decl)
5086     {
5087       if (/* Check online inline functions that were actually used.  */
5088           DECL_ODR_USED (decl) && DECL_DECLARED_INLINE_P (decl)
5089           /* If the definition actually was available here, then the
5090              fact that the function was not defined merely represents
5091              that for some reason (use of a template repository,
5092              #pragma interface, etc.) we decided not to emit the
5093              definition here.  */
5094           && !DECL_INITIAL (decl)
5095           /* Don't complain if the template was defined.  */
5096           && !(DECL_TEMPLATE_INSTANTIATION (decl)
5097                && DECL_INITIAL (DECL_TEMPLATE_RESULT
5098                                 (template_for_substitution (decl))))
5099           && warning_at (DECL_SOURCE_LOCATION (decl), 0,
5100                          "inline function %qD used but never defined", decl))
5101         /* Avoid a duplicate warning from check_global_declaration.  */
5102         TREE_NO_WARNING (decl) = 1;
5103     }
5104
5105   /* So must decls that use a type with no linkage.  */
5106   FOR_EACH_VEC_SAFE_ELT (no_linkage_decls, i, decl)
5107     no_linkage_error (decl);
5108
5109   maybe_warn_sized_delete ();
5110
5111   /* Then, do the Objective-C stuff.  This is where all the
5112      Objective-C module stuff gets generated (symtab,
5113      class/protocol/selector lists etc).  This must be done after C++
5114      templates, destructors etc. so that selectors used in C++
5115      templates are properly allocated.  */
5116   if (c_dialect_objc ())
5117     objc_write_global_declarations ();
5118
5119   /* We give C linkage to static constructors and destructors.  */
5120   push_lang_context (lang_name_c);
5121
5122   /* Generate initialization and destruction functions for all
5123      priorities for which they are required.  */
5124   if (priority_info_map)
5125     splay_tree_foreach (priority_info_map,
5126                         generate_ctor_and_dtor_functions_for_priority,
5127                         /*data=*/&locus_at_end_of_parsing);
5128   else if (c_dialect_objc () && objc_static_init_needed_p ())
5129     /* If this is obj-c++ and we need a static init, call
5130        generate_ctor_or_dtor_function.  */
5131     generate_ctor_or_dtor_function (/*constructor_p=*/true,
5132                                     DEFAULT_INIT_PRIORITY,
5133                                     &locus_at_end_of_parsing);
5134
5135   /* We're done with the splay-tree now.  */
5136   if (priority_info_map)
5137     splay_tree_delete (priority_info_map);
5138
5139   /* Generate any missing aliases.  */
5140   maybe_apply_pending_pragma_weaks ();
5141
5142   /* We're done with static constructors, so we can go back to "C++"
5143      linkage now.  */
5144   pop_lang_context ();
5145
5146   if (flag_vtable_verify)
5147     {
5148       vtv_recover_class_info ();
5149       vtv_compute_class_hierarchy_transitive_closure ();
5150       vtv_build_vtable_verify_fndecl ();
5151     }
5152
5153   perform_deferred_noexcept_checks ();
5154
5155   fini_constexpr ();
5156
5157   /* The entire file is now complete.  If requested, dump everything
5158      to a file.  */
5159   dump_tu ();
5160
5161   if (flag_detailed_statistics)
5162     {
5163       dump_tree_statistics ();
5164       dump_time_statistics ();
5165     }
5166
5167   timevar_stop (TV_PHASE_DEFERRED);
5168   timevar_start (TV_PHASE_PARSING);
5169
5170   /* Indicate that we're done with front end processing.  */
5171   at_eof = 2;
5172 }
5173
5174 /* Perform any post compilation-proper cleanups for the C++ front-end.
5175    This should really go away.  No front-end should need to do
5176    anything past the compilation process.  */
5177
5178 void
5179 cxx_post_compilation_parsing_cleanups (void)
5180 {
5181   timevar_start (TV_PHASE_LATE_PARSING_CLEANUPS);
5182
5183   if (flag_vtable_verify)
5184     {
5185       /* Generate the special constructor initialization function that
5186          calls __VLTRegisterPairs, and give it a very high
5187          initialization priority.  This must be done after
5188          finalize_compilation_unit so that we have accurate
5189          information about which vtable will actually be emitted.  */
5190       vtv_generate_init_routine ();
5191     }
5192
5193   input_location = locus_at_end_of_parsing;
5194
5195   if (flag_checking)
5196     validate_conversion_obstack ();
5197
5198   timevar_stop (TV_PHASE_LATE_PARSING_CLEANUPS);
5199 }
5200
5201 /* FN is an OFFSET_REF, DOTSTAR_EXPR or MEMBER_REF indicating the
5202    function to call in parse-tree form; it has not yet been
5203    semantically analyzed.  ARGS are the arguments to the function.
5204    They have already been semantically analyzed.  This may change
5205    ARGS.  */
5206
5207 tree
5208 build_offset_ref_call_from_tree (tree fn, vec<tree, va_gc> **args,
5209                                  tsubst_flags_t complain)
5210 {
5211   tree orig_fn;
5212   vec<tree, va_gc> *orig_args = NULL;
5213   tree expr;
5214   tree object;
5215
5216   orig_fn = fn;
5217   object = TREE_OPERAND (fn, 0);
5218
5219   if (processing_template_decl)
5220     {
5221       gcc_assert (TREE_CODE (fn) == DOTSTAR_EXPR
5222                   || TREE_CODE (fn) == MEMBER_REF);
5223       if (type_dependent_expression_p (fn)
5224           || any_type_dependent_arguments_p (*args))
5225         return build_min_nt_call_vec (fn, *args);
5226
5227       orig_args = make_tree_vector_copy (*args);
5228
5229       /* Transform the arguments and add the implicit "this"
5230          parameter.  That must be done before the FN is transformed
5231          because we depend on the form of FN.  */
5232       make_args_non_dependent (*args);
5233       object = build_non_dependent_expr (object);
5234       if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
5235         {
5236           if (TREE_CODE (fn) == DOTSTAR_EXPR)
5237             object = cp_build_addr_expr (object, complain);
5238           vec_safe_insert (*args, 0, object);
5239         }
5240       /* Now that the arguments are done, transform FN.  */
5241       fn = build_non_dependent_expr (fn);
5242     }
5243
5244   /* A qualified name corresponding to a bound pointer-to-member is
5245      represented as an OFFSET_REF:
5246
5247         struct B { void g(); };
5248         void (B::*p)();
5249         void B::g() { (this->*p)(); }  */
5250   if (TREE_CODE (fn) == OFFSET_REF)
5251     {
5252       tree object_addr = cp_build_addr_expr (object, complain);
5253       fn = TREE_OPERAND (fn, 1);
5254       fn = get_member_function_from_ptrfunc (&object_addr, fn,
5255                                              complain);
5256       vec_safe_insert (*args, 0, object_addr);
5257     }
5258
5259   if (CLASS_TYPE_P (TREE_TYPE (fn)))
5260     expr = build_op_call (fn, args, complain);
5261   else
5262     expr = cp_build_function_call_vec (fn, args, complain);
5263   if (processing_template_decl && expr != error_mark_node)
5264     expr = build_min_non_dep_call_vec (expr, orig_fn, orig_args);
5265
5266   if (orig_args != NULL)
5267     release_tree_vector (orig_args);
5268
5269   return expr;
5270 }
5271
5272
5273 void
5274 check_default_args (tree x)
5275 {
5276   tree arg = TYPE_ARG_TYPES (TREE_TYPE (x));
5277   bool saw_def = false;
5278   bool noted_first_def = false;
5279   int idx_of_first_default_arg = 0;
5280   location_t loc_of_first_default_arg = UNKNOWN_LOCATION;
5281   int i = 0 - (TREE_CODE (TREE_TYPE (x)) == METHOD_TYPE);
5282   tree fndecl = STRIP_TEMPLATE (x);
5283   auto_diagnostic_group d;
5284   for (; arg && arg != void_list_node; arg = TREE_CHAIN (arg), ++i)
5285     {
5286       if (TREE_PURPOSE (arg))
5287         {
5288           if (!saw_def)
5289             {
5290               saw_def = true;
5291               idx_of_first_default_arg = i;
5292               location_t loc = get_fndecl_argument_location (fndecl, i);
5293               if (loc != DECL_SOURCE_LOCATION (x))
5294                 loc_of_first_default_arg = loc;
5295             }
5296         }
5297       else if (saw_def && !PACK_EXPANSION_P (TREE_VALUE (arg)))
5298         {
5299           error_at (get_fndecl_argument_location (fndecl, i),
5300                     "default argument missing for parameter %P of %q#D", i, x);
5301           if (loc_of_first_default_arg != UNKNOWN_LOCATION
5302               && !noted_first_def)
5303             {
5304               inform (loc_of_first_default_arg,
5305                       "...following parameter %P which has a default argument",
5306                       idx_of_first_default_arg);
5307               noted_first_def = true;
5308             }
5309           TREE_PURPOSE (arg) = error_mark_node;
5310         }
5311     }
5312 }
5313
5314 /* Return true if function DECL can be inlined.  This is used to force
5315    instantiation of methods that might be interesting for inlining.  */
5316 bool
5317 possibly_inlined_p (tree decl)
5318 {
5319   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
5320   if (DECL_UNINLINABLE (decl))
5321     return false;
5322   if (!optimize)
5323     return DECL_DECLARED_INLINE_P (decl);
5324   /* When optimizing, we might inline everything when flatten
5325      attribute or heuristics inlining for size or autoinlining
5326      is used.  */
5327   return true;
5328 }
5329
5330 /* Normally, we can wait until instantiation-time to synthesize DECL.
5331    However, if DECL is a static data member initialized with a constant
5332    or a constexpr function, we need it right now because a reference to
5333    such a data member or a call to such function is not value-dependent.
5334    For a function that uses auto in the return type, we need to instantiate
5335    it to find out its type.  For OpenMP user defined reductions, we need
5336    them instantiated for reduction clauses which inline them by hand
5337    directly.  */
5338
5339 static void
5340 maybe_instantiate_decl (tree decl)
5341 {
5342   if (DECL_LANG_SPECIFIC (decl)
5343       && DECL_TEMPLATE_INFO (decl)
5344       && (decl_maybe_constant_var_p (decl)
5345           || (TREE_CODE (decl) == FUNCTION_DECL
5346               && DECL_OMP_DECLARE_REDUCTION_P (decl))
5347           || undeduced_auto_decl (decl))
5348       && !DECL_DECLARED_CONCEPT_P (decl)
5349       && !uses_template_parms (DECL_TI_ARGS (decl)))
5350     {
5351       /* Instantiating a function will result in garbage collection.  We
5352          must treat this situation as if we were within the body of a
5353          function so as to avoid collecting live data only referenced from
5354          the stack (such as overload resolution candidates).  */
5355       ++function_depth;
5356       instantiate_decl (decl, /*defer_ok=*/false,
5357                         /*expl_inst_class_mem_p=*/false);
5358       --function_depth;
5359     }
5360 }
5361
5362 /* Maybe warn if DECL is deprecated, subject to COMPLAIN.  Returns whether or
5363    not a warning was emitted.  */
5364
5365 bool
5366 cp_warn_deprecated_use (tree decl, tsubst_flags_t complain)
5367 {
5368   if (!(complain & tf_warning) || !decl
5369       || deprecated_state == DEPRECATED_SUPPRESS)
5370     return false;
5371
5372   if (!TREE_DEPRECATED (decl))
5373     {
5374       /* Perhaps this is a deprecated typedef.  */
5375       if (TYPE_P (decl) && TYPE_NAME (decl))
5376         decl = TYPE_NAME (decl);
5377
5378       if (!TREE_DEPRECATED (decl))
5379         return false;
5380     }
5381
5382   /* Don't warn within members of a deprecated type.  */
5383   if (TYPE_P (decl)
5384       && currently_open_class (decl))
5385     return false;
5386
5387   bool warned = false;
5388   if (cxx_dialect >= cxx11
5389       && DECL_P (decl)
5390       && DECL_ARTIFICIAL (decl)
5391       && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl)
5392       && copy_fn_p (decl))
5393     {
5394       if (warn_deprecated_copy
5395           /* Don't warn about system library classes (c++/86342).  */
5396           && (!DECL_IN_SYSTEM_HEADER (decl)
5397               || global_dc->dc_warn_system_headers))
5398         {
5399           auto_diagnostic_group d;
5400           tree ctx = DECL_CONTEXT (decl);
5401           tree other = classtype_has_depr_implicit_copy (ctx);
5402           int opt = (DECL_DESTRUCTOR_P (other)
5403                      ? OPT_Wdeprecated_copy_dtor
5404                      : OPT_Wdeprecated_copy);
5405           warned = warning (opt, "implicitly-declared %qD is deprecated",
5406                             decl);
5407           if (warned)
5408             inform (DECL_SOURCE_LOCATION (other),
5409                     "because %qT has user-provided %qD",
5410                     ctx, other);
5411         }
5412     }
5413   else
5414     warned = warn_deprecated_use (decl, NULL_TREE);
5415
5416   return warned;
5417 }
5418
5419 /* Like above, but takes into account outer scopes.  */
5420
5421 void
5422 cp_warn_deprecated_use_scopes (tree scope)
5423 {
5424   while (scope
5425          && scope != error_mark_node
5426          && scope != global_namespace)
5427     {
5428       if (cp_warn_deprecated_use (scope))
5429         return;
5430       if (TYPE_P (scope))
5431         scope = CP_TYPE_CONTEXT (scope);
5432       else
5433         scope = CP_DECL_CONTEXT (scope);
5434     }
5435 }
5436
5437 /* True if DECL or its enclosing scope have unbound template parameters.  */
5438
5439 bool
5440 decl_dependent_p (tree decl)
5441 {
5442   if (DECL_FUNCTION_SCOPE_P (decl)
5443       || TREE_CODE (decl) == CONST_DECL
5444       || TREE_CODE (decl) == USING_DECL
5445       || TREE_CODE (decl) == FIELD_DECL)
5446     decl = CP_DECL_CONTEXT (decl);
5447   if (tree tinfo = get_template_info (decl))
5448     if (any_dependent_template_arguments_p (TI_ARGS (tinfo)))
5449       return true;
5450   if (LAMBDA_FUNCTION_P (decl)
5451       && dependent_type_p (DECL_CONTEXT (decl)))
5452     return true;
5453   return false;
5454 }
5455
5456 /* Mark DECL (either a _DECL or a BASELINK) as "used" in the program.
5457    If DECL is a specialization or implicitly declared class member,
5458    generate the actual definition.  Return false if something goes
5459    wrong, true otherwise.  */
5460
5461 bool
5462 mark_used (tree decl, tsubst_flags_t complain)
5463 {
5464   /* If we're just testing conversions or resolving overloads, we
5465      don't want any permanent effects like forcing functions to be
5466      output or instantiating templates.  */
5467   if ((complain & tf_conv))
5468     return true;
5469
5470   /* If DECL is a BASELINK for a single function, then treat it just
5471      like the DECL for the function.  Otherwise, if the BASELINK is
5472      for an overloaded function, we don't know which function was
5473      actually used until after overload resolution.  */
5474   if (BASELINK_P (decl))
5475     {
5476       decl = BASELINK_FUNCTIONS (decl);
5477       if (really_overloaded_fn (decl))
5478         return true;
5479       decl = OVL_FIRST (decl);
5480     }
5481
5482   if (!DECL_P (decl))
5483     return true;
5484
5485   /* Set TREE_USED for the benefit of -Wunused.  */
5486   TREE_USED (decl) = 1;
5487   /* And for structured bindings also the underlying decl.  */
5488   if (DECL_DECOMPOSITION_P (decl) && DECL_DECOMP_BASE (decl))
5489     TREE_USED (DECL_DECOMP_BASE (decl)) = 1;
5490
5491   if (TREE_CODE (decl) == TEMPLATE_DECL)
5492     return true;
5493
5494   if (DECL_CLONED_FUNCTION_P (decl))
5495     TREE_USED (DECL_CLONED_FUNCTION (decl)) = 1;
5496
5497   /* Mark enumeration types as used.  */
5498   if (TREE_CODE (decl) == CONST_DECL)
5499     used_types_insert (DECL_CONTEXT (decl));
5500
5501   if (TREE_CODE (decl) == FUNCTION_DECL
5502       && DECL_MAYBE_DELETED (decl))
5503     {
5504       /* ??? Switch other defaulted functions to use DECL_MAYBE_DELETED?  */
5505       gcc_assert (special_function_p (decl) == sfk_comparison);
5506
5507       ++function_depth;
5508       synthesize_method (decl);
5509       --function_depth;
5510     }
5511
5512   if (TREE_CODE (decl) == FUNCTION_DECL
5513       && !maybe_instantiate_noexcept (decl, complain))
5514     return false;
5515
5516   if (TREE_CODE (decl) == FUNCTION_DECL
5517       && DECL_DELETED_FN (decl))
5518     {
5519       if (DECL_ARTIFICIAL (decl)
5520           && DECL_CONV_FN_P (decl)
5521           && LAMBDA_TYPE_P (DECL_CONTEXT (decl)))
5522         /* We mark a lambda conversion op as deleted if we can't
5523            generate it properly; see maybe_add_lambda_conv_op.  */
5524         sorry ("converting lambda that uses %<...%> to function pointer");
5525       else if (complain & tf_error)
5526         {
5527           error ("use of deleted function %qD", decl);
5528           if (!maybe_explain_implicit_delete (decl))
5529             inform (DECL_SOURCE_LOCATION (decl), "declared here");
5530         }
5531       return false;
5532     }
5533
5534   cp_warn_deprecated_use (decl, complain);
5535
5536   /* We can only check DECL_ODR_USED on variables or functions with
5537      DECL_LANG_SPECIFIC set, and these are also the only decls that we
5538      might need special handling for.  */
5539   if (!VAR_OR_FUNCTION_DECL_P (decl)
5540       || DECL_LANG_SPECIFIC (decl) == NULL
5541       || DECL_THUNK_P (decl))
5542     {
5543       if (!decl_dependent_p (decl)
5544           && !require_deduced_type (decl, complain))
5545         return false;
5546       return true;
5547     }
5548
5549   /* We only want to do this processing once.  We don't need to keep trying
5550      to instantiate inline templates, because unit-at-a-time will make sure
5551      we get them compiled before functions that want to inline them.  */
5552   if (DECL_ODR_USED (decl))
5553     return true;
5554
5555   /* Normally, we can wait until instantiation-time to synthesize DECL.
5556      However, if DECL is a static data member initialized with a constant
5557      or a constexpr function, we need it right now because a reference to
5558      such a data member or a call to such function is not value-dependent.
5559      For a function that uses auto in the return type, we need to instantiate
5560      it to find out its type.  For OpenMP user defined reductions, we need
5561      them instantiated for reduction clauses which inline them by hand
5562      directly.  */
5563   maybe_instantiate_decl (decl);
5564
5565   if (flag_concepts && TREE_CODE (decl) == FUNCTION_DECL
5566       && !constraints_satisfied_p (decl))
5567     {
5568       if (complain & tf_error)
5569         {
5570           auto_diagnostic_group d;
5571           error ("use of function %qD with unsatisfied constraints",
5572                  decl);
5573           location_t loc = DECL_SOURCE_LOCATION (decl);
5574           inform (loc, "declared here");
5575           diagnose_constraints (loc, decl, NULL_TREE);
5576         }
5577       return false;
5578     }
5579
5580   if (processing_template_decl || in_template_function ())
5581     return true;
5582
5583   /* Check this too in case we're within instantiate_non_dependent_expr.  */
5584   if (DECL_TEMPLATE_INFO (decl)
5585       && uses_template_parms (DECL_TI_ARGS (decl)))
5586     return true;
5587
5588   if (!require_deduced_type (decl, complain))
5589     return false;
5590
5591   if (builtin_pack_fn_p (decl))
5592     {
5593       error ("use of built-in parameter pack %qD outside of a template",
5594              DECL_NAME (decl));
5595       return false;
5596     }
5597
5598   /* If we don't need a value, then we don't need to synthesize DECL.  */
5599   if (cp_unevaluated_operand || in_discarded_stmt)
5600     return true;
5601
5602   DECL_ODR_USED (decl) = 1;
5603   if (DECL_CLONED_FUNCTION_P (decl))
5604     DECL_ODR_USED (DECL_CLONED_FUNCTION (decl)) = 1;
5605
5606   /* DR 757: A type without linkage shall not be used as the type of a
5607      variable or function with linkage, unless
5608    o the variable or function has extern "C" linkage (7.5 [dcl.link]), or
5609    o the variable or function is not used (3.2 [basic.def.odr]) or is
5610    defined in the same translation unit.  */
5611   if (cxx_dialect > cxx98
5612       && decl_linkage (decl) != lk_none
5613       && !DECL_EXTERN_C_P (decl)
5614       && !DECL_ARTIFICIAL (decl)
5615       && !decl_defined_p (decl)
5616       && no_linkage_check (TREE_TYPE (decl), /*relaxed_p=*/false))
5617     {
5618       if (is_local_extern (decl))
5619         /* There's no way to define a local extern, and adding it to
5620            the vector interferes with GC, so give an error now.  */
5621         no_linkage_error (decl);
5622       else
5623         vec_safe_push (no_linkage_decls, decl);
5624     }
5625
5626   if (TREE_CODE (decl) == FUNCTION_DECL
5627       && DECL_DECLARED_INLINE_P (decl)
5628       && !DECL_INITIAL (decl)
5629       && !DECL_ARTIFICIAL (decl)
5630       && !DECL_PURE_VIRTUAL_P (decl))
5631     /* Remember it, so we can check it was defined.  */
5632     note_vague_linkage_fn (decl);
5633
5634   /* Is it a synthesized method that needs to be synthesized?  */
5635   if (TREE_CODE (decl) == FUNCTION_DECL
5636       && DECL_DEFAULTED_FN (decl)
5637       /* A function defaulted outside the class is synthesized either by
5638          cp_finish_decl or instantiate_decl.  */
5639       && !DECL_DEFAULTED_OUTSIDE_CLASS_P (decl)
5640       && ! DECL_INITIAL (decl))
5641     {
5642       /* Defer virtual destructors so that thunks get the right
5643          linkage.  */
5644       if (DECL_VIRTUAL_P (decl) && !at_eof)
5645         {
5646           note_vague_linkage_fn (decl);
5647           return true;
5648         }
5649
5650       /* Remember the current location for a function we will end up
5651          synthesizing.  Then we can inform the user where it was
5652          required in the case of error.  */
5653       if (DECL_ARTIFICIAL (decl))
5654         DECL_SOURCE_LOCATION (decl) = input_location;
5655
5656       /* Synthesizing an implicitly defined member function will result in
5657          garbage collection.  We must treat this situation as if we were
5658          within the body of a function so as to avoid collecting live data
5659          on the stack (such as overload resolution candidates).
5660
5661          We could just let c_parse_final_cleanups handle synthesizing
5662          this function by adding it to deferred_fns, but doing
5663          it at the use site produces better error messages.  */
5664       ++function_depth;
5665       synthesize_method (decl);
5666       --function_depth;
5667       /* If this is a synthesized method we don't need to
5668          do the instantiation test below.  */
5669     }
5670   else if (VAR_OR_FUNCTION_DECL_P (decl)
5671            && DECL_TEMPLATE_INFO (decl)
5672            && !DECL_DECLARED_CONCEPT_P (decl)
5673            && (!DECL_EXPLICIT_INSTANTIATION (decl)
5674                || always_instantiate_p (decl)))
5675     /* If this is a function or variable that is an instance of some
5676        template, we now know that we will need to actually do the
5677        instantiation. We check that DECL is not an explicit
5678        instantiation because that is not checked in instantiate_decl.
5679
5680        We put off instantiating functions in order to improve compile
5681        times.  Maintaining a stack of active functions is expensive,
5682        and the inliner knows to instantiate any functions it might
5683        need.  Therefore, we always try to defer instantiation.  */
5684     {
5685       ++function_depth;
5686       instantiate_decl (decl, /*defer_ok=*/true,
5687                         /*expl_inst_class_mem_p=*/false);
5688       --function_depth;
5689     }
5690
5691   return true;
5692 }
5693
5694 bool
5695 mark_used (tree decl)
5696 {
5697   return mark_used (decl, tf_warning_or_error);
5698 }
5699
5700 tree
5701 vtv_start_verification_constructor_init_function (void)
5702 {
5703   return start_objects ('I', MAX_RESERVED_INIT_PRIORITY - 1);
5704 }
5705
5706 tree
5707 vtv_finish_verification_constructor_init_function (tree function_body)
5708 {
5709   tree fn;
5710
5711   finish_compound_stmt (function_body);
5712   fn = finish_function (/*inline_p=*/false);
5713   DECL_STATIC_CONSTRUCTOR (fn) = 1;
5714   decl_init_priority_insert (fn, MAX_RESERVED_INIT_PRIORITY - 1);
5715
5716   return fn;
5717 }
5718
5719 #include "gt-cp-decl2.h"