| blob | 2a52f8ca3e206fd74f927569c59a7c4fa2d518dc |
1 /* Process declarations and variables for C++ compiler.
2 Copyright (C) 1988-2017 Free Software Foundation, Inc.
3 Hacked by Michael Tiemann (tiemann@cygnus.com)
5 This file is part of GCC.
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.
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.
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/>. */
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. */
26 /* ??? not all decl nodes are given the most useful possible
27 line numbers. For example, the CONST_DECLs for enum values. */
52 /* Id for dumping the raw trees. */
57 /* This structure contains information about the initializations
58 and/or destructions required for a particular priority level. */
60 /* Nonzero if there have been any initializations at this priority
61 throughout the translation unit. */
63 /* Nonzero if there have been any destructions at this priority
64 throughout the translation unit. */
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. */
93 /* A list of functions which were declared inline, but which we
94 may need to emit outline anyway. */
97 /* A list of decls that use types with no linkage, which we need to make
98 sure are defined. */
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. */
105 /* Nonzero if we're done parsing and into end-of-file activities. */
109 /* True if note_mangling_alias should enqueue mangling aliases for
110 later generation, rather than emitting them right away. */
113 \f
115 /* Return a member function type (a METHOD_TYPE), given FNTYPE (a
116 FUNCTION_TYPE), CTYPE (class type), and QUALS (the cv-qualifiers
117 that apply to the function). */
119 tree
121 cp_ref_qualifier rqual)
122 {
123 tree raises;
124 tree attrs;
153 }
155 /* Return a variant of FNTYPE, a FUNCTION_TYPE or METHOD_TYPE, with its
156 return type changed to NEW_RET. */
158 tree
160 {
161 tree newtype;
174 {
179 }
180 else
181 newtype = build_method_type_directly
193 }
195 /* Build a PARM_DECL of FN with NAME and TYPE, and set DECL_ARG_TYPE
196 appropriately. */
198 tree
200 {
205 /* DECL_ARG_TYPE is only used by the back end and the back end never
206 sees templates. */
211 }
213 /* Returns a PARM_DECL of FN for a parameter of the indicated TYPE, with the
214 indicated NAME. */
216 tree
218 {
221 /* All our artificial parms are implicitly `const'; they cannot be
222 assigned to. */
225 }
227 /* Constructors for types with virtual baseclasses need an "in-charge" flag
228 saying whether this constructor is responsible for initialization of
229 virtual baseclasses or not. All destructors also need this "in-charge"
230 flag, which additionally determines whether or not the destructor should
231 free the memory for the object.
233 This function adds the "in-charge" flag to member function FN if
234 appropriate. It is called from grokclassfn and tsubst.
235 FN must be either a constructor or destructor.
237 The in-charge flag follows the 'this' parameter, and is followed by the
238 VTT parm (if any), then the user-written parms. */
240 void
242 {
245 /* If we've already add the in-charge parameter don't do it again. */
249 /* When processing templates we can't know, in general, whether or
250 not we're going to have virtual baseclasses. */
254 /* We don't need an in-charge parameter for constructors that don't
255 have virtual bases. */
266 /* If this is a subobject constructor or destructor, our caller will
267 pass us a pointer to our VTT. */
269 {
272 /* First add it to DECL_ARGUMENTS between 'this' and the real args... */
276 /* ...and then to TYPE_ARG_TYPES. */
280 }
282 /* Then add the in-charge parm (before the VTT parm). */
288 /* Insert our new parameter(s) into the list. */
291 /* And rebuild the function type. */
293 arg_types);
298 fntype = (cp_build_type_attribute_variant
302 /* Now we've got the in-charge parameter. */
304 }
306 /* Classes overload their constituent function names automatically.
307 When a function name is declared in a record structure,
308 its name is changed to it overloaded name. Since names for
309 constructors and destructors can conflict, we place a leading
310 '$' for destructors.
312 CNAME is the name of the class we are grokking for.
314 FUNCTION is a FUNCTION_DECL. It was created by `grokdeclarator'.
316 FLAGS contains bits saying what's special about today's
317 arguments. DTOR_FLAG == DESTRUCTOR.
319 If FUNCTION is a destructor, then we must add the `auto-delete' field
320 as a second parameter. There is some hair associated with the fact
321 that we must "declare" this variable in the manner consistent with the
322 way the rest of the arguments were declared.
324 QUALS are the qualifiers for the this pointer. */
326 void
328 {
331 /* Even within an `extern "C"' block, members get C++ linkage. See
332 [dcl.link] for details. */
336 {
340 }
349 }
351 /* Create an ARRAY_REF, checking for the user doing things backwards
352 along the way. DECLTYPE_P is for N3276, as in the parser. */
354 tree
357 {
358 tree type;
359 tree expr;
368 {
375 }
381 /* If they have an `operator[]', use that. */
383 {
389 }
390 else
391 {
394 /* Otherwise, create an ARRAY_REF for a pointer or array type.
395 It is a little-known fact that, if `a' is an array and `i' is
396 an int, you can write `i[a]', which means the same thing as
397 `a[i]'. */
400 else
405 else
420 else
421 {
425 }
431 }
433 {
440 }
442 }
444 /* Given the cast expression EXP, checking out its validity. Either return
445 an error_mark_node if there was an unavoidable error, return a cast to
446 void for trying to delete a pointer w/ the value 0, or return the
447 call to delete. If DOING_VEC is true, we handle things differently
448 for doing an array delete.
449 Implements ARM $5.3.4. This is called from the parser. */
451 tree
453 tsubst_flags_t complain)
454 {
461 {
467 }
469 /* An array can't have been allocated by new, so complain. */
476 {
480 }
484 /* As of Valley Forge, you can delete a pointer to const. */
486 /* You can't delete functions. */
488 {
492 }
494 /* Deleting ptr to void is undefined behavior [expr.delete/3]. */
496 {
499 }
501 /* Deleting a pointer with the value zero is valid and has no effect. */
507 sfk_deleting_destructor,
509 else
512 complain);
513 }
515 /* Report an error if the indicated template declaration is not the
516 sort of thing that should be a member template. */
518 void
520 {
521 tree decl;
530 {
531 /* The parser rejects template declarations in local classes
532 (with the exception of generic lambdas). */
534 /* The parser rejects any use of virtual in a function template. */
538 /* The debug-information generating code doesn't know what to do
539 with member templates. */
541 }
544 else
546 }
548 /* Sanity check: report error if this function FUNCTION is not
549 really a member of the class (CTYPE) it is supposed to belong to.
550 TEMPLATE_PARMS is used to specify the template parameters of a member
551 template passed as FUNCTION_DECL. If the member template is passed as a
552 TEMPLATE_DECL, it can be NULL since the parameters can be extracted
553 from the declaration. If the function is not a function template, it
554 must be NULL.
555 It returns the original declaration for the function, NULL_TREE if
556 no declaration was found, error_mark_node if an error was emitted. */
558 tree
560 {
565 /* Since this is a specialization of a member template,
566 we're not going to find the declaration in the class.
567 For example, in:
569 struct S { template <typename T> void f(T); };
570 template <> void S::f(int);
572 we're not going to find `S::f(int)', but there's no
573 reason we should, either. We let our callers know we didn't
574 find the method, but we don't complain. */
577 /* Basic sanity check: for a template function, the template parameters
578 either were not passed, or they are the same of DECL_TEMPLATE_PARMS. */
580 {
584 {
588 }
590 }
592 /* OK, is this a definition of a member template? */
595 /* [temp.mem]
597 A destructor shall not be a member template. */
599 {
602 }
604 /* We must enter the scope here, because conversion operators are
605 named by target type, and type equivalence relies on typenames
606 resolving within the scope of CTYPE. */
612 {
617 /* We cannot simply call decls_match because this doesn't work
618 for static member functions that are pretending to be
619 methods, and because the name may have been changed by
620 asm("new_name"). */
622 /* Get rid of the this parameter on functions that become
623 static. */
628 /* A member template definition only matches a member template
629 declaration. */
633 /* ref-qualifier or absence of same must match. */
638 // Include constraints in the match.
642 /* While finding a match, same types and params are not enough
643 if the function is versioned. Also check version ("target")
644 attributes. */
649 && (!is_template
658 }
661 {
664 else
665 {
676 else
681 }
683 }
689 }
691 /* DECL is a function with vague linkage. Remember it so that at the
692 end of the translation unit we can decide whether or not to emit
693 it. */
695 void
697 {
700 }
702 /* As above, but for variable template instantiations. */
704 void
706 {
708 }
710 /* We have just processed the DECL, which is a static data member.
711 The other parameters are as for cp_finish_decl. */
713 void
716 tree asmspec_tree,
718 {
721 /* We cannot call pushdecl here, because that would fill in the
722 TREE_CHAIN of our decl. Instead, we modify cp_finish_decl to do
723 the right thing, namely, to put this decl out straight away. */
729 /* We already complained about the template definition. */
733 else
737 {
743 }
752 }
754 /* DECLARATOR and DECLSPECS correspond to a class member. The other
755 parameters are as for cp_finish_decl. Return the DECL for the
756 class member declared. */
758 tree
762 tree asmspec_tree,
763 tree attrlist)
764 {
765 tree value;
768 tree name;
778 /* friend or constructor went bad. */
784 {
787 }
789 /* Pass friendly classes back. */
797 {
799 {
802 }
807 value);
808 }
810 /* Stash away type declarations. */
812 {
817 {
820 /* If this is a typedef that names the class for linkage purposes
821 (7.1.3p8), apply any attributes directly to the type. */
827 }
834 /* It's important that push_template_decl below follows
835 set_underlying_type above so that the created template
836 carries the properly set type of VALUE. */
842 }
847 {
850 }
856 {
858 {
860 {
864 }
866 {
868 {
872 }
873 }
877 {
882 else
884 value);
885 }
886 else
887 {
891 value);
892 else
894 value);
895 }
896 }
901 }
903 /* Pass friend decls back. */
909 /* Need to set this before push_template_decl. */
914 {
918 }
925 else
929 {
954 /* Pass friends back this way. */
963 }
965 }
967 /* Like `grokfield', but for bitfields.
968 WIDTH is non-NULL for bit fields only, and is an INTEGER_CST node. */
970 tree
973 tree attrlist)
974 {
982 /* Pass friendly classes back. */
989 {
992 }
995 {
998 }
1000 /* Usually, finish_struct_1 catches bitfields with invalid types.
1001 But, in the case of bitfields with function type, we confuse
1002 ourselves into thinking they are member functions, so we must
1003 check here. */
1005 {
1009 }
1012 {
1016 }
1019 {
1022 }
1026 {
1027 /* The width must be an integer type. */
1032 else
1033 {
1036 }
1037 }
1045 }
1047 \f
1048 /* Returns true iff ATTR is an attribute which needs to be applied at
1049 instantiation time rather than template definition time. */
1051 static bool
1053 {
1057 tree arg;
1060 /* Unknown attribute. */
1063 /* Attribute weak handling wants to write out assembly right away. */
1067 /* Attributes used and unused are applied directly, as they appertain to
1068 decls. */
1073 /* Attribute tls_model wants to modify the symtab. */
1077 /* #pragma omp declare simd attribute needs to be always deferred. */
1082 /* An attribute pack is clearly dependent. */
1086 /* If any of the arguments are dependent expressions, we can't evaluate
1087 the attribute until instantiation time. */
1089 {
1092 /* If the first attribute argument is an identifier, only consider
1093 second and following arguments. Attributes like mode, format,
1094 cleanup and several target specific attributes aren't late
1095 just because they have an IDENTIFIER_NODE as first argument. */
1103 }
1108 {
1111 /* We can't apply any attributes to a completely unknown type until
1112 instantiation time. */
1118 /* Also defer most attributes on dependent types. This is not
1119 necessary in all cases, but is the better default. */
1121 /* But some attributes specifically apply to templates. */
1126 else
1128 }
1129 else
1131 }
1133 /* ATTR_P is a list of attributes. Remove any attributes which need to be
1134 applied at instantiation time and return them. If IS_DEPENDENT is true,
1135 the declaration itself is dependent, so all attributes should be applied
1136 at instantiation time. */
1138 static tree
1140 {
1149 {
1151 {
1157 }
1158 else
1160 }
1163 }
1165 /* Remove any late attributes from the list in ATTR_P and attach them to
1166 DECL_P. */
1168 static void
1170 {
1182 else
1187 /* Merge the late attributes at the beginning with the attribute
1188 list. */
1193 {
1194 /* We've added new attributes directly to the main variant, so
1195 now we need to update all of the other variants to include
1196 these new attributes. */
1197 tree variant;
1200 {
1203 }
1204 }
1205 }
1207 /* True if ATTRS contains any dependent attributes that affect type
1208 identity. */
1210 bool
1212 {
1215 {
1219 }
1221 }
1223 /* Return true iff ATTRS are acceptable attributes to be applied in-place
1224 to a typedef which gives a previously unnamed class or enum a name for
1225 linkage purposes. */
1227 bool
1229 {
1231 {
1235 }
1237 }
1239 /* Like reconstruct_complex_type, but handle also template trees. */
1241 tree
1243 {
1248 {
1252 }
1254 {
1258 }
1260 {
1263 /* Don't call cp_build_qualified_type on ARRAY_TYPEs, the
1264 element type qualification will be handled by the recursive
1265 cp_reconstruct_complex_type call and cp_build_qualified_type
1266 for ARRAY_TYPEs changes the element type. */
1268 }
1270 {
1277 }
1279 {
1282 /* The build_method_type_directly() routine prepends 'this' to argument list,
1283 so we must compensate by getting rid of it. */
1284 outer
1285 = build_method_type_directly
1288 }
1290 {
1293 }
1294 else
1305 }
1307 /* Replaces any constexpr expression that may be into the attributes
1308 arguments with their reduced value. */
1310 static void
1312 {
1316 tree attr;
1318 {
1319 tree arg;
1321 {
1325 }
1326 }
1327 }
1329 /* Return true if TYPE is an OpenMP mappable type. */
1330 bool
1332 {
1333 /* Mappable type has to be complete. */
1336 /* Arrays have mappable type if the elements have mappable type. */
1339 /* A mappable type cannot contain virtual members. */
1342 /* All data members must be non-static. */
1344 {
1345 tree field;
1349 /* All fields must have mappable types. */
1353 }
1355 }
1357 /* Like decl_attributes, but handle C++ complexity. */
1359 void
1361 {
1366 /* Add implicit "omp declare target" attribute if requested. */
1371 {
1381 else
1384 }
1387 {
1392 }
1400 {
1401 attributes
1405 }
1406 else
1412 /* Propagate deprecation out to the template. */
1415 {
1421 }
1422 }
1423 \f
1424 /* Walks through the namespace- or function-scope anonymous union
1425 OBJECT, with the indicated TYPE, building appropriate VAR_DECLs.
1426 Returns one of the fields for use in the mangled name. */
1428 static tree
1430 {
1432 tree field;
1434 /* Rather than write the code to handle the non-union case,
1435 just give an error. */
1437 {
1440 }
1445 {
1446 tree decl;
1447 tree ref;
1452 {
1454 "%q#D invalid; an anonymous union can only "
1457 }
1469 else
1474 {
1475 tree base;
1491 }
1494 else
1499 }
1502 }
1504 /* Finish off the processing of a UNION_TYPE structure. If the union is an
1505 anonymous union, then all members must be laid out together. PUBLIC_P
1506 is nonzero if this union is not declared static. */
1508 void
1510 {
1511 tree type;
1512 tree main_decl;
1521 /* The VAR_DECL's context is the same as the TYPE's context. */
1528 {
1531 }
1537 {
1540 }
1543 {
1544 /* Use main_decl to set the mangled name. */
1550 }
1554 }
1555 \f
1556 /* Auxiliary functions to make type signatures for
1557 `operator new' and `operator delete' correspond to
1558 what compiler will be expecting. */
1560 tree
1562 {
1569 {
1572 }
1575 {
1577 {
1578 /* [basic.stc.dynamic.allocation]
1580 The first parameter shall not have an associated default
1581 argument. */
1584 /* Throw away the default argument. */
1586 }
1589 {
1592 }
1593 }
1594 else
1602 {
1605 /* Fall through. */
1607 type = build_exception_variant
1610 /* Fall through. */
1612 }
1614 }
1616 tree
1618 {
1625 {
1628 }
1632 {
1637 ptr_type_node);
1638 }
1640 {
1643 /* Fall through. */
1645 type = build_exception_variant
1648 /* Fall through. */
1650 }
1653 }
1654 \f
1655 /* DECL is a VAR_DECL for a vtable: walk through the entries in the vtable
1656 and mark them as needed. */
1658 static void
1660 {
1661 tree fnaddr;
1664 /* It's OK for the vtable to refer to deprecated virtual functions. */
1669 {
1670 tree fn;
1676 /* This entry is an offset: a virtual base class offset, a
1677 virtual call offset, an RTTI offset, etc. */
1682 /* When we don't have vcall offsets, we output thunks whenever
1683 we output the vtables that contain them. With vcall offsets,
1684 we know all the thunks we'll need when we emit a virtual
1685 function, so we emit the thunks there instead. */
1689 }
1690 }
1692 /* Set DECL up to have the closest approximation of "initialized common"
1693 linkage available. */
1695 void
1697 {
1702 /* We can just emit function and compiler-generated variables
1703 statically; having multiple copies is (for the most part) only
1704 a waste of space.
1706 There are two correctness issues, however: the address of a
1707 template instantiation with external linkage should be the
1708 same, independent of what translation unit asks for the
1709 address, and this will not hold when we emit multiple copies of
1710 the function. However, there's little else we can do.
1712 Also, by default, the typeinfo implementation assumes that
1713 there will be only one copy of the string used as the name for
1714 each type. Therefore, if weak symbols are unavailable, the
1715 run-time library should perform a more conservative check; it
1716 should perform a string comparison, rather than an address
1717 comparison. */
1719 else
1720 {
1721 /* Static data member template instantiations, however, cannot
1722 have multiple copies. */
1727 {
1730 }
1732 {
1733 /* We can't do anything useful; leave vars for explicit
1734 instantiation. */
1737 }
1738 }
1742 }
1744 /* For win32 we also want to put explicit instantiations in
1745 linkonce sections, so that they will be merged with implicit
1746 instantiations; otherwise we get duplicate symbol errors.
1747 For Darwin we do not want explicit instantiations to be
1748 linkonce. */
1750 void
1752 {
1753 /* We used to say that this was not necessary on targets that support weak
1754 symbols, because the implicit instantiations will defer to the explicit
1755 one. However, that's not actually the case in SVR4; a strong definition
1756 after a weak one is an error. Also, not making explicit
1757 instantiations one_only means that we can end up with two copies of
1758 some template instantiations. */
1762 /* We can't set DECL_COMDAT on functions, or cp_finish_file will think
1763 we can get away with not emitting them if they aren't used. We need
1764 to for variables so that cp_finish_decl will update their linkage,
1765 because their DECL_INITIAL may not have been set properly yet. */
1770 {
1774 {
1777 /* Mark it needed so we don't forget to emit it. */
1780 }
1781 }
1782 }
1784 /* Returns true iff DECL, a FUNCTION_DECL or VAR_DECL, has vague linkage.
1785 This predicate will give the right answer during parsing of the
1786 function, which other tests may not. */
1788 bool
1790 {
1792 {
1793 /* maybe_thunk_body clears TREE_PUBLIC on the maybe-in-charge 'tor
1794 variants, check one of the "clones" for the real linkage. */
1803 }
1804 /* Unfortunately, import_export_decl has not always been called
1805 before the function is processed, so we cannot simply check
1806 DECL_COMDAT. */
1815 /* A local static in an inline effectively has vague linkage. */
1818 else
1820 }
1822 /* Determine whether or not we want to specifically import or export CTYPE,
1823 using various heuristics. */
1825 static void
1827 {
1828 /* -1 for imported, 1 for exported. */
1831 /* It only makes sense to call this function at EOF. The reason is
1832 that this function looks at whether or not the first non-inline
1833 non-abstract virtual member function has been defined in this
1834 translation unit. But, we can't possibly know that until we've
1835 seen the entire translation unit. */
1841 /* If MULTIPLE_SYMBOL_SPACES is set and we saw a #pragma interface,
1842 we will have CLASSTYPE_INTERFACE_ONLY set but not
1843 CLASSTYPE_INTERFACE_KNOWN. In that case, we don't want to use this
1844 heuristic because someone will supply a #pragma implementation
1845 elsewhere, and deducing it here would produce a conflict. */
1855 /* For a template class, without -fimplicit-templates, check the
1856 repository. If the virtual table is assigned to this
1857 translation unit, then export the class; otherwise, import
1858 it. */
1861 {
1862 /* The ABI specifies that the virtual table and associated
1863 information are emitted with the key method, if any. */
1865 /* If weak symbol support is not available, then we must be
1866 careful not to emit the vtable when the key function is
1867 inline. An inline function can be defined in multiple
1868 translation units. If we were to emit the vtable in each
1869 translation unit containing a definition, we would get
1870 multiple definition errors at link-time. */
1873 }
1875 /* When MULTIPLE_SYMBOL_SPACES is set, we cannot count on seeing
1876 a definition anywhere else. */
1880 /* Allow back ends the chance to overrule the decision. */
1885 {
1888 }
1889 }
1891 /* Return true if VAR has already been provided to the back end; in that
1892 case VAR should not be modified further by the front end. */
1893 static bool
1895 {
1897 }
1899 /* DECL is a VAR_DECL or FUNCTION_DECL which, for whatever reason,
1900 must be emitted in this translation unit. Mark it as such. */
1902 void
1904 {
1907 {
1908 /* Extern inline functions don't become needed when referenced.
1909 If we know a method will be emitted in other TU and no new
1910 functions can be marked reachable, just use the external
1911 definition. */
1915 /* #pragma interface and -frepo code can call mark_needed for
1916 maybe-in-charge 'tors; mark the clones as well. */
1917 tree clone;
1920 }
1922 {
1924 /* C++ frontend use mark_decl_references to force COMDAT variables
1925 to be output that might appear dead otherwise. */
1927 }
1928 }
1930 /* DECL is either a FUNCTION_DECL or a VAR_DECL. This function
1931 returns true if a definition of this entity should be provided in
1932 this object file. Callers use this function to determine whether
1933 or not to let the back end know that a definition of DECL is
1934 available in this translation unit. */
1936 bool
1938 {
1940 /* This function should only be called at the end of the translation
1941 unit. We cannot be sure of whether or not something will be
1942 COMDAT until that point. */
1945 /* All entities with external linkage that are not COMDAT/EXTERN should be
1946 emitted; they may be referred to from other object files. */
1949 /* Functions marked "dllexport" must be emitted so that they are
1950 visible to other DLLs. */
1955 /* When not optimizing, do not bother to produce definitions for extern
1956 symbols. */
1965 /* If this entity was used, let the back end see it; it will decide
1966 whether or not to emit it into the object file. */
1970 /* Virtual functions might be needed for devirtualization. */
1976 /* Otherwise, DECL does not need to be emitted -- yet. A subsequent
1977 reference to DECL might cause it to be emitted later. */
1979 }
1981 /* If necessary, write out the vtables for the dynamic class CTYPE.
1982 Returns true if any vtables were emitted. */
1984 static bool
1986 {
1987 tree vtbl;
1988 tree primary_vtbl;
1992 /* If the vtables for this class have already been emitted there is
1993 nothing more to do. */
1997 /* Ignore dummy vtables made by get_vtable_decl. */
2001 /* On some targets, we cannot determine the key method until the end
2002 of the translation unit -- which is when this function is
2003 called. */
2007 /* See if any of the vtables are needed. */
2009 {
2013 }
2015 {
2016 /* If the references to this class' vtables are optimized away,
2017 still emit the appropriate debugging information. See
2018 dfs_debug_mark. */
2023 }
2025 /* The ABI requires that we emit all of the vtables if we emit any
2026 of them. */
2028 {
2029 /* Mark entities references from the virtual table as used. */
2033 {
2036 LOOKUP_NORMAL);
2038 /* It had better be all done at compile-time. */
2040 }
2042 /* Write it out. */
2046 /* Because we're only doing syntax-checking, we'll never end up
2047 actually marking the variable as written. */
2051 {
2056 }
2057 }
2059 /* Since we're writing out the vtable here, also write the debug
2060 info. */
2064 }
2066 /* A special return value from type_visibility meaning internal
2067 linkage. */
2071 /* walk_tree helper function for type_visibility. */
2073 static tree
2075 {
2078 {
2080 }
2083 {
2086 }
2091 }
2093 /* Returns the visibility of TYPE, which is the minimum visibility of its
2094 component types. */
2096 static int
2098 {
2102 }
2104 /* Limit the visibility of DECL to VISIBILITY, if not explicitly
2105 specified (or if VISIBILITY is static). If TMPL is true, this
2106 constraint is for a template argument, and takes precedence
2107 over explicitly-specified visibility on the template. */
2109 static void
2111 {
2113 {
2114 /* extern "C" declarations aren't affected by the anonymous
2115 namespace. */
2117 {
2123 {
2128 }
2132 }
2133 }
2136 {
2138 /* This visibility was not specified. */
2140 }
2141 }
2143 /* Constrain the visibility of DECL based on the visibility of its template
2144 arguments. */
2146 static void
2148 {
2149 /* If this is a template instantiation, check the innermost
2150 template args for visibility constraints. The outer template
2151 args are covered by the class check. */
2155 {
2161 else
2162 {
2170 {
2173 else
2175 }
2176 }
2179 }
2180 }
2182 /* Like c_determine_visibility, but with additional C++-specific
2183 behavior.
2185 Function-scope entities can rely on the function's visibility because
2186 it is set in start_preparsed_function.
2188 Class-scope entities cannot rely on the class's visibility until the end
2189 of the enclosing class definition.
2191 Note that because namespaces have multiple independent definitions,
2192 namespace visibility is handled elsewhere using the #pragma visibility
2193 machinery rather than by decorating the namespace declaration.
2195 The goal is for constraints from the type to give a diagnostic, and
2196 other constraints to be applied silently. */
2198 void
2200 {
2201 /* Remember that all decls get VISIBILITY_DEFAULT when built. */
2203 /* Only relevant for names with external linkage. */
2207 /* Cloned constructors and destructors get the same visibility as
2208 the underlying function. That should be set up in
2209 maybe_clone_body. */
2215 /* The decl may be a template instantiation, which could influence
2216 visibilty. */
2219 {
2221 {
2224 }
2227 }
2231 /* If DECL is a member of a class, visibility specifiers on the
2232 class can influence the visibility of the DECL. */
2236 else
2237 {
2238 /* Not a class member. */
2240 /* Virtual tables have DECL_CONTEXT set to their associated class,
2241 so they are automatically handled above. */
2246 {
2247 /* Local statics and classes get the visibility of their
2248 containing function by default, except that
2249 -fvisibility-inlines-hidden doesn't affect them. */
2252 {
2256 }
2257 else
2258 {
2262 {
2266 }
2267 else
2268 {
2272 }
2273 }
2275 /* Local classes in templates have CLASSTYPE_USE_TEMPLATE set,
2276 but have no TEMPLATE_INFO. Their containing template
2277 function does, and the local class could be constrained
2278 by that. */
2281 }
2284 {
2285 /* Under -fvisibility-ms-compat, types are visible by default,
2286 even though their contents aren't. */
2293 else
2295 }
2297 {
2298 /* tinfo visibility is based on the type it's for. */
2299 constrain_visibility
2302 /* Give the target a chance to override the visibility associated
2303 with DECL. */
2309 }
2311 /* Template instantiations and specializations get visibility based
2314 {
2317 else
2318 {
2319 /* Set default visibility to whatever the user supplied with
2320 #pragma GCC visibility or a namespace visibility attribute. */
2323 }
2324 }
2325 }
2328 {
2329 /* If the specialization doesn't specify visibility, use the
2330 visibility from the template. */
2338 {
2342 {
2346 else
2347 {
2351 }
2352 }
2355 /* Template argument visibility outweighs #pragma or namespace
2356 visibility, but not an explicit attribute. */
2358 {
2361 {
2362 /* A class template member with explicit visibility
2363 overrides the class visibility, so we need to apply
2364 all the levels of template args directly. */
2367 {
2370 }
2371 }
2373 /* Limit visibility based on its template arguments. */
2375 }
2376 }
2377 }
2383 /* Names in an anonymous namespace get internal linkage.
2384 This might change once we implement export. */
2387 {
2388 /* Propagate anonymity from type to decl. */
2393 }
2395 /* DR 757: A type without linkage shall not be used as the type of a
2396 variable or function with linkage, unless
2397 o the variable or function has extern "C" linkage (7.5 [dcl.link]), or
2398 o the variable or function is not used (3.2 [basic.def.odr]) or is
2399 defined in the same translation unit.
2401 Since non-extern "C" decls need to be defined in the same
2402 translation unit, we can make the type internal. */
2405 /* If visibility changed and DECL already has DECL_RTL, ensure
2406 symbol flags are updated. */
2413 }
2415 /* By default, static data members and function members receive
2416 the visibility of their containing class. */
2418 static void
2420 {
2426 else
2427 {
2428 /* Default to the class visibility. */
2432 }
2434 /* Give the target a chance to override the visibility associated
2435 with DECL. */
2439 /* Construction virtual tables are not exported because
2440 they cannot be referred to from other object files;
2441 their name is not standardized by the ABI. */
2447 }
2449 /* Returns true iff DECL is an inline that should get hidden visibility
2450 because of -fvisibility-inlines-hidden. */
2452 static bool
2454 {
2456 /* Don't do this for inline templates; specializations might not be
2457 inline, and we don't want them to inherit the hidden
2458 visibility. We'll set it here for all inline instantiations. */
2459 && !processing_template_decl
2464 }
2466 /* Constrain the visibility of a class TYPE based on the visibility of its
2467 field types. Warn if any fields require lesser visibility. */
2469 void
2471 {
2472 tree binfo;
2473 tree t;
2482 /* Don't warn about visibility if the class has explicit visibility. */
2488 {
2493 {
2495 {
2498 {
2503 else
2507 }
2508 else
2512 }
2513 }
2520 }
2524 {
2528 {
2530 {
2533 {
2538 else
2542 }
2543 else
2547 }
2548 }
2554 }
2555 }
2557 /* Functions for adjusting the visibility of a tagged type and its nested
2558 types and declarations when it gets a name for linkage purposes from a
2559 typedef. */
2564 /* First reset the visibility of all the types. */
2566 static void
2568 {
2573 }
2574 static void
2576 {
2578 }
2580 /* Then reset the visibility of any static data members or member
2581 functions that use those types. */
2583 static void
2585 {
2594 }
2596 static void
2598 {
2600 {
2602 {
2607 }
2609 {
2615 }
2617 {
2621 }
2624 }
2625 }
2627 static void
2629 {
2631 }
2632 void
2634 {
2637 }
2639 /* Set up our initial idea of what the linkage of DECL should be. */
2641 void
2643 {
2645 /* We've already made a decision as to how this function will
2648 {
2651 {
2655 /* A non-template inline function with external linkage will
2656 always be COMDAT. As we must eventually determine the
2657 linkage of all functions, and as that causes writes to
2658 the data mapped in from the PCH file, it's advantageous
2659 to mark the functions at this point. */
2663 {
2664 /* This function must have external linkage, as
2665 otherwise DECL_INTERFACE_KNOWN would have been
2666 set. */
2670 }
2671 }
2674 }
2675 }
2677 /* DECL is a FUNCTION_DECL or VAR_DECL. If the object file linkage
2678 for DECL has not already been determined, do so now by setting
2679 DECL_EXTERNAL, DECL_COMDAT and other related flags. Until this
2680 function is called entities with vague linkage whose definitions
2681 are available must have TREE_PUBLIC set.
2683 If this function decides to place DECL in COMDAT, it will set
2684 appropriate flags -- but will not clear DECL_EXTERNAL. It is up to
2685 the caller to decide whether or not to clear DECL_EXTERNAL. Some
2686 callers defer that decision until it is clear that DECL is actually
2687 required. */
2689 void
2691 {
2700 /* We cannot determine what linkage to give to an entity with vague
2701 linkage until the end of the file. For example, a virtual table
2702 for a class will be defined if and only if the key method is
2703 defined in this translation unit. As a further example, consider
2704 that when compiling a translation unit that uses PCH file with
2705 "-frepo" it would be incorrect to make decisions about what
2706 entities to emit when building the PCH; those decisions must be
2707 delayed until the repository information has been processed. */
2709 /* Object file linkage for explicit instantiations is handled in
2710 mark_decl_instantiated. For static variables in functions with
2711 vague linkage, maybe_commonize_var is used.
2713 Therefore, the only declarations that should be provided to this
2714 function are those with external linkage that are:
2716 * implicit instantiations of function templates
2718 * inline function
2720 * implicit instantiations of static data members of class
2721 templates
2723 * virtual tables
2725 * typeinfo objects
2727 Furthermore, all entities that reach this point must have a
2728 definition available in this translation unit.
2730 The following assertions check these conditions. */
2732 /* Any code that creates entities with TREE_PUBLIC cleared should
2733 also set DECL_INTERFACE_KNOWN. */
2739 else
2743 /* Check that a definition of DECL is available in this translation
2744 unit. */
2747 /* Assume that DECL will not have COMDAT linkage. */
2749 /* Assume that DECL will not be imported into this translation
2750 unit. */
2753 /* See if the repository tells us whether or not to emit DECL in
2754 this translation unit. */
2759 {
2760 /* The repository indicates that this entity should be defined
2761 here. Make sure the back end honors that request. */
2763 /* Output the definition as an ordinary strong definition. */
2767 }
2770 /* We have already decided what to do with this DECL; there is no
2771 need to check anything further. */
2772 ;
2774 {
2784 /* The ABI requires that all virtual tables be emitted with
2785 COMDAT linkage. However, on systems where COMDAT symbols
2786 don't show up in the table of contents for a static
2787 archive, or on systems without weak symbols (where we
2788 approximate COMDAT linkage by using internal linkage), the
2789 linker will report errors about undefined symbols because
2790 it will not see the virtual table definition. Therefore,
2791 in the case that we know that the virtual table will be
2792 emitted in only one translation unit, we make the virtual
2793 table an ordinary definition with external linkage. */
2796 {
2797 /* CLASS_TYPE is being exported from this translation unit,
2798 so DECL should be defined here. */
2800 /* If a class is declared in a header with the "extern
2801 template" extension, then it will not be instantiated,
2802 even in translation units that would normally require
2803 it. Often such classes are explicitly instantiated in
2804 one translation unit. Therefore, the explicit
2805 instantiation must be made visible to other translation
2806 units. */
2808 else
2809 {
2810 /* The generic C++ ABI says that class data is always
2811 COMDAT, even if there is a key function. Some
2812 variants (e.g., the ARM EABI) says that class data
2813 only has COMDAT linkage if the class data might be
2814 emitted in more than one translation unit. When the
2815 key method can be inline and is inline, we still have
2816 to arrange for comdat even though
2817 class_data_always_comdat is false. */
2821 {
2822 /* The ABI requires COMDAT linkage. Normally, we
2823 only emit COMDAT things when they are needed;
2824 make sure that we realize that this entity is
2825 indeed needed. */
2828 }
2829 }
2830 }
2834 else
2836 }
2838 {
2841 {
2847 /* If -fno-rtti was specified, then we cannot be sure
2848 that RTTI information will be emitted with the
2849 virtual table of the class, so we must emit it
2850 wherever it is used. */
2853 else
2854 {
2857 {
2863 {
2866 }
2867 }
2868 else
2870 }
2871 }
2872 else
2874 }
2876 {
2877 /* DECL is an implicit instantiation of a function or static
2878 data member. */
2881 || (flag_implicit_inline_templates
2885 else
2886 /* If we are not implicitly generating templates, then mark
2887 this entity as undefined in this translation unit. */
2889 }
2891 {
2893 {
2897 {
2901 && ! flag_implement_inlines
2907 /* Always make artificials weak. */
2910 else
2912 }
2913 }
2914 else
2916 }
2917 else
2921 {
2922 /* If we are importing DECL into this translation unit, mark is
2923 an undefined here. */
2926 }
2928 {
2929 /* If we decided to put DECL in COMDAT, mark it accordingly at
2930 this point. */
2932 }
2935 }
2937 /* Return an expression that performs the destruction of DECL, which
2938 must be a VAR_DECL whose type has a non-trivial destructor, or is
2939 an array whose (innermost) elements have a non-trivial destructor. */
2941 tree
2943 {
2947 }
2949 /* Returns the initialization guard variable for the variable DECL,
2950 which has static storage duration. */
2952 tree
2954 {
2955 tree sname;
2956 tree guard;
2961 {
2962 tree guard_type;
2964 /* We use a type that is big enough to contain a mutex as well
2965 as an integer counter. */
2970 /* The guard should have the same linkage as what it guards. */
2988 }
2990 }
2992 /* Return an atomic load of src with the appropriate memory model. */
2994 static tree
2996 {
3011 }
3013 /* Return those bits of the GUARD variable that should be set when the
3014 guarded entity is actually initialized. */
3016 static tree
3018 {
3020 {
3021 /* We only set the first byte of the guard, in order to leave room
3022 for a mutex in the high-order bits. */
3025 guard);
3028 guard);
3030 }
3033 }
3035 /* Return an expression which determines whether or not the GUARD
3036 variable has already been initialized. */
3038 tree
3040 {
3041 tree guard_value;
3045 else
3048 /* Mask off all but the low bit. */
3050 {
3056 tf_warning_or_error);
3057 }
3064 tf_warning_or_error);
3065 }
3067 /* Return an expression which sets the GUARD variable, indicating that
3068 the variable being guarded has been initialized. */
3070 tree
3072 {
3073 tree guard_init;
3075 /* Set the GUARD to one. */
3081 tf_warning_or_error);
3082 }
3084 /* Returns true iff we can tell that VAR does not have a dynamic
3085 initializer. */
3087 static bool
3089 {
3090 /* If it's defined in another TU, we can't tell. */
3093 /* If it has a non-trivial destructor, registering the destructor
3094 counts as dynamic initialization. */
3097 /* If it's in this TU, its initializer has been processed, unless
3098 it's a case of self-initialization, then DECL_INITIALIZED_P is
3099 false while the initializer is handled by finish_id_expression. */
3102 /* If it has no initializer or a constant one, it's not dynamic. */
3105 }
3107 /* Returns true iff VAR is a variable that needs uses to be
3108 wrapped for possible dynamic initialization. */
3110 static bool
3112 {
3118 }
3120 /* Get the FUNCTION_DECL for the shared TLS init function for this
3121 translation unit. */
3123 static tree
3125 {
3129 {
3132 void_list_node));
3138 }
3140 }
3142 /* Get a FUNCTION_DECL for the init function for the thread_local
3143 variable VAR. The init function will be an alias to the function
3144 that initializes all the non-local TLS variables in the translation
3145 unit. The init function is only used by the wrapper function. */
3147 static tree
3149 {
3150 /* Only C++11 TLS vars need this init fn. */
3154 /* If -fno-extern-tls-init, assume that we don't need to call
3155 a tls init function for a variable defined in another TU. */
3159 #ifdef ASM_OUTPUT_DEF
3160 /* If the variable is internal, or if we can't generate aliases,
3161 call the local init function directly. */
3163 #endif
3169 {
3172 void_list_node));
3181 {
3183 /* If the variable is defined somewhere else and might have static
3184 initialization, make the init function a weak reference. */
3190 else
3192 }
3202 }
3204 }
3206 /* Get a FUNCTION_DECL for the init wrapper function for the thread_local
3207 variable VAR. The wrapper function calls the init function (if any) for
3208 VAR and then returns a reference to VAR. The wrapper function is used
3209 in place of VAR everywhere VAR is mentioned. */
3211 tree
3213 {
3214 /* Only C++11 TLS vars need this wrapper fn. */
3221 {
3222 /* A named rvalue reference is an lvalue, so the wrapper should
3223 always return an lvalue reference. */
3232 /* The wrapper is inline and emitted everywhere var is used. */
3235 {
3237 #ifdef HAVE_GAS_HIDDEN
3238 /* Make the wrapper bind locally; there's no reason to share
3239 the wrapper between multiple shared objects. */
3242 #endif
3243 }
3249 #if 0
3250 /* We want CSE to commonize calls to the wrapper, but marking it as
3251 pure is unsafe since it has side-effects. I guess we need a new
3252 ECF flag even weaker than ECF_PURE. FIXME! */
3254 #endif
3259 }
3261 }
3263 /* At EOF, generate the definition for the TLS wrapper function FN:
3265 T& var_wrapper() {
3266 if (init_fn) init_fn();
3267 return var;
3268 } */
3270 static void
3272 {
3277 /* Only call the init fn if there might be one. */
3279 {
3281 /* If init_fn is a weakref, make sure it exists before calling. */
3283 {
3288 tf_warning_or_error);
3290 }
3294 {
3297 }
3298 }
3299 else
3300 /* If there's no initialization, the wrapper is a constant function. */
3305 }
3307 /* Start the process of running a particular set of global constructors
3308 or destructors. Subroutine of do_[cd]tors. Also called from
3309 vtv_start_verification_constructor_init_function. */
3311 static tree
3313 {
3314 tree body;
3315 tree fndecl;
3318 /* Make ctor or dtor function. METHOD_TYPE may be 'I' or 'D'. */
3321 {
3324 #ifdef JOINER
3326 #else
3328 #endif
3331 }
3332 else
3338 NULL_TREE));
3343 /* Mark as artificial because it's not explicitly in the user's
3344 source code. */
3347 /* Mark this declaration as used to avoid spurious warnings. */
3350 /* Mark this function as a global constructor or destructor. */
3353 else
3359 }
3361 /* Finish the process of running a particular set of global constructors
3362 or destructors. Subroutine of do_[cd]tors. */
3364 static void
3366 {
3367 tree fn;
3369 /* Finish up. */
3374 {
3377 }
3378 else
3379 {
3382 }
3385 }
3387 /* The names of the parameters to the function created to handle
3388 initializations and destructions for objects with static storage
3389 duration. */
3393 /* The name of the function we create to handle initializations and
3394 destructions for objects with static storage duration. */
3397 /* The declaration for the __INITIALIZE_P argument. */
3400 /* The declaration for the __PRIORITY argument. */
3403 /* The declaration for the static storage duration function. */
3406 /* All the static storage duration functions created in this
3407 translation unit. */
3410 /* A map from priority levels to information about that priority
3411 level. There may be many such levels, so efficient lookup is
3412 important. */
3415 /* Begins the generation of the function that will handle all
3416 initialization and destruction of objects with static storage
3417 duration. The function generated takes two parameters of type
3418 `int': __INITIALIZE_P and __PRIORITY. If __INITIALIZE_P is
3419 nonzero, it performs initializations. Otherwise, it performs
3420 destructions. It only performs those initializations or
3421 destructions with the indicated __PRIORITY. The generated function
3422 returns no value.
3424 It is assumed that this function will only be called once per
3425 translation unit. */
3427 static tree
3429 {
3430 tree type;
3431 tree body;
3434 /* Create the identifier for this function. It will be of the form
3435 SSDF_IDENTIFIER_<number>. */
3440 NULL_TREE);
3442 /* Create the FUNCTION_DECL itself. */
3445 type);
3449 /* Put this function in the list of functions to be called from the
3450 static constructors and destructors. */
3452 {
3455 /* Take this opportunity to initialize the map from priority
3456 numbers to information about that priority level. */
3459 /*delete_value_fn=*/
3462 /* We always need to generate functions for the
3463 DEFAULT_INIT_PRIORITY so enter it now. That way when we walk
3464 priorities later, we'll be sure to find the
3465 DEFAULT_INIT_PRIORITY. */
3467 }
3471 /* Create the argument list. */
3472 initialize_p_decl = cp_build_parm_decl
3475 priority_decl = cp_build_parm_decl
3482 /* Put the function in the global scope. */
3485 /* Start the function itself. This is equivalent to declaring the
3486 function as:
3488 static void __ssdf (int __initialize_p, init __priority_p);
3490 It is static because we only need to call this function from the
3491 various constructor and destructor functions for this module. */
3494 SF_PRE_PARSED);
3496 /* Set up the scope of the outermost block in the function. */
3500 }
3502 /* Finish the generation of the function which performs initialization
3503 and destruction of objects with static storage duration. After
3504 this point, no more such objects can be created. */
3506 static void
3508 {
3509 /* Close out the function. */
3512 }
3514 /* Return the information about the indicated PRIORITY level. If no
3515 code to handle this level has yet been generated, generate the
3516 appropriate prologue. */
3518 static priority_info
3520 {
3521 priority_info pi;
3522 splay_tree_node n;
3527 {
3528 /* Create a new priority information structure, and insert it
3529 into the map. */
3536 }
3537 else
3541 }
3543 /* The effective initialization priority of a DECL. */
3545 #define DECL_EFFECTIVE_INIT_PRIORITY(decl) \
3546 ((!DECL_HAS_INIT_PRIORITY_P (decl) || DECL_INIT_PRIORITY (decl) == 0) \
3547 ? DEFAULT_INIT_PRIORITY : DECL_INIT_PRIORITY (decl))
3549 /* Whether a DECL needs a guard to protect it against multiple
3550 initialization. */
3552 #define NEEDS_GUARD_P(decl) (TREE_PUBLIC (decl) && (DECL_COMMON (decl) \
3553 || DECL_ONE_ONLY (decl) \
3554 || DECL_WEAK (decl)))
3556 /* Called from one_static_initialization_or_destruction(),
3557 via walk_tree.
3558 Walks the initializer list of a global variable and looks for
3559 temporary variables (DECL_NAME() == NULL and DECL_ARTIFICIAL != 0)
3560 and that have their DECL_CONTEXT() == NULL.
3561 For each such temporary variable, set their DECL_CONTEXT() to
3562 the current function. This is necessary because otherwise
3563 some optimizers (enabled by -O2 -fprofile-arcs) might crash
3564 when trying to refer to a temporary variable that does not have
3565 it's DECL_CONTECT() properly set. */
3566 static tree
3570 {
3574 {
3575 tree var;
3583 }
3586 }
3588 /* Set up to handle the initialization or destruction of DECL. If
3589 INITP is nonzero, we are initializing the variable. Otherwise, we
3590 are destroying it. */
3592 static void
3594 {
3596 tree guard;
3598 /* If we are supposed to destruct and there's a trivial destructor,
3599 nothing has to be done. */
3604 /* Trick the compiler into thinking we are at the file and line
3605 where DECL was declared so that error-messages make sense, and so
3606 that the debugger will show somewhat sensible file and line
3607 information. */
3610 /* Make sure temporary variables in the initialiser all have
3611 their DECL_CONTEXT() set to a value different from NULL_TREE.
3612 This can happen when global variables initializers are built.
3613 In that case, the DECL_CONTEXT() of the global variables _AND_ of all
3614 the temporary variables that might have been generated in the
3615 accompanying initializers is NULL_TREE, meaning the variables have been
3616 declared in the global namespace.
3617 What we want to do here is to fix that and make sure the DECL_CONTEXT()
3618 of the temporaries are set to the current function decl. */
3620 fix_temporary_vars_context_r,
3621 NULL);
3623 /* Because of:
3625 [class.access.spec]
3627 Access control for implicit calls to the constructors,
3628 the conversion functions, or the destructor called to
3629 create and destroy a static data member is performed as
3630 if these calls appeared in the scope of the member's
3631 class.
3633 we pretend we are in a static member function of the class of
3634 which the DECL is a member. */
3636 {
3639 }
3641 /* Assume we don't need a guard. */
3643 /* We need a guard if this is an object with external linkage that
3644 might be initialized in more than one place. (For example, a
3645 static data member of a template, when the data member requires
3646 construction.) */
3648 {
3649 tree guard_cond;
3653 /* When using __cxa_atexit, we just check the GUARD as we would
3654 for a local static. */
3656 {
3657 /* When using __cxa_atexit, we never try to destroy
3658 anything from a static destructor. */
3661 }
3662 /* If we don't have __cxa_atexit, then we will be running
3663 destructors from .fini sections, or their equivalents. So,
3664 we need to know how many times we've tried to initialize this
3665 object. We do initializations only if the GUARD is zero,
3666 i.e., if we are the first to initialize the variable. We do
3667 destructions only if the GUARD is one, i.e., if we are the
3668 last to destroy the variable. */
3670 guard_cond
3672 EQ_EXPR,
3674 guard,
3676 tf_warning_or_error),
3677 integer_one_node,
3678 tf_warning_or_error);
3679 else
3680 guard_cond
3682 EQ_EXPR,
3684 guard,
3686 tf_warning_or_error),
3687 integer_zero_node,
3688 tf_warning_or_error);
3692 }
3695 /* If we're using __cxa_atexit, we have not already set the GUARD,
3696 so we must do so now. */
3700 /* Perform the initialization or destruction. */
3702 {
3704 {
3707 {
3711 }
3712 }
3714 /* If we're using __cxa_atexit, register a function that calls the
3715 destructor for the object. */
3718 }
3719 else
3722 /* Finish the guard if-stmt, if necessary. */
3724 {
3727 }
3729 /* Now that we're done with DECL we don't need to pretend to be a
3730 member of its class any longer. */
3733 }
3735 /* Generate code to do the initialization or destruction of the decls in VARS,
3736 a TREE_LIST of VAR_DECL with static storage duration.
3737 Whether initialization or destruction is performed is specified by INITP. */
3739 static void
3741 {
3744 /* Build the outer if-stmt to check for initialization or destruction. */
3748 EQ_EXPR,
3749 initialize_p_decl,
3750 cond,
3751 tf_warning_or_error);
3754 /* To make sure dynamic construction doesn't access globals from other
3755 compilation units where they might not be yet constructed, for
3756 -fsanitize=address insert __asan_before_dynamic_init call that
3757 prevents access to either all global variables that need construction
3758 in other compilation units, or at least those that haven't been
3759 initialized yet. Variables that need dynamic construction in
3760 the current compilation unit are kept accessible. */
3767 tree priority_if_stmt;
3769 priority_info pi;
3771 /* If we don't need a destructor, there's nothing to do. Avoid
3772 creating a possibly empty if-stmt. */
3774 {
3777 }
3779 /* Remember that we had an initialization or finalization at this
3780 priority. */
3785 else
3788 /* Conditionalize this initialization on being in the right priority
3789 and being initializing/finalizing appropriately. */
3792 EQ_EXPR,
3793 priority_decl,
3795 tf_warning_or_error);
3798 /* Process initializers with same priority. */
3802 /* Do one initialization or destruction. */
3806 /* Finish up the priority if-stmt body. */
3812 /* Revert what __asan_before_dynamic_init did by calling
3813 __asan_after_dynamic_init. */
3817 /* Finish up the init/destruct if-stmt body. */
3820 }
3822 /* VARS is a list of variables with static storage duration which may
3823 need initialization and/or finalization. Remove those variables
3824 that don't really need to be initialized or finalized, and return
3825 the resulting list. The order in which the variables appear in
3826 VARS is in reverse order of the order in which they should actually
3827 be initialized. The list we return is in the unreversed order;
3828 i.e., the first variable should be initialized first. */
3830 static tree
3832 {
3837 {
3842 /* Deal gracefully with error. */
3844 {
3847 }
3849 /* The only things that can be initialized are variables. */
3852 /* If this object is not defined, we don't need to do anything
3853 here. */
3855 {
3858 }
3860 /* Also, if the initializer already contains errors, we can bail
3861 out now. */
3864 {
3867 }
3869 /* This variable is going to need initialization and/or
3870 finalization, so we add it to the list. */
3874 }
3877 }
3879 /* Make sure we have told the back end about all the variables in
3880 VARS. */
3882 static void
3884 {
3885 tree v;
3888 {
3891 {
3894 }
3895 }
3896 }
3898 /* Generate a static constructor (if CONSTRUCTOR_P) or destructor
3899 (otherwise) that will initialize all global objects with static
3900 storage duration having the indicated PRIORITY. */
3902 static void
3905 {
3907 tree fndecl;
3908 tree body;
3912 /* ??? */
3913 /* Was: locus->line++; */
3915 /* We use `I' to indicate initialization and `D' to indicate
3916 destruction. */
3919 /* We emit the function lazily, to avoid generating empty
3920 global constructors and destructors. */
3923 /* For Objective-C++, we may need to initialize metadata found in this module.
3924 This must be done _before_ any other static initializations. */
3927 {
3930 }
3932 /* Call the static storage duration function with appropriate
3933 arguments. */
3935 {
3936 /* Calls to pure or const functions will expand to nothing. */
3938 {
3939 tree call;
3946 constructor_p),
3948 priority),
3949 NULL_TREE);
3951 }
3952 }
3954 /* Close out the function. */
3957 }
3959 /* Generate constructor and destructor functions for the priority
3960 indicated by N. */
3962 static int
3964 {
3969 /* Generate the functions themselves, but only if they are really
3970 needed. */
3976 /* Keep iterating. */
3978 }
3980 /* Return C++ property of T, based on given operation OP. */
3982 static int
3984 {
3986 {
3988 {
3996 }
4013 }
4014 }
4016 /* Collect source file references recursively, starting from NAMESPC. */
4018 static void
4020 {
4021 /* Iterate over names in this name space. */
4024 ;
4027 else
4029 }
4031 /* Collect decls relevant to SOURCE_FILE from all namespaces recursively,
4032 starting from NAMESPC. */
4034 static void
4036 {
4039 /* Collect decls from this namespace. This will skip
4040 NAMESPACE_DECLs (both aliases and regular, it cannot tell). */
4043 /* Now scan for namespace children, and dump them. */
4047 }
4049 /* Returns true iff there is a definition available for variable or
4050 function DECL. */
4052 bool
4054 {
4057 /* A pending instantiation of a friend temploid is defined. */
4061 else
4062 {
4065 }
4066 }
4068 /* Nonzero for a VAR_DECL whose value can be used in a constant expression.
4070 [expr.const]
4072 An integral constant-expression can only involve ... const
4073 variables of integral or enumeration types initialized with
4074 constant expressions ...
4076 C++0x also allows constexpr variables and temporaries initialized
4077 with constant expressions. We handle the former here, but the latter
4078 are just folded away in cxx_eval_constant_expression.
4080 The standard does not require that the expression be non-volatile.
4081 G++ implements the proposed correction in DR 457. */
4083 bool
4085 {
4089 /* We don't know if a template static data member is initialized with
4090 a constant expression until we instantiate its initializer. Even
4091 in the case of a constexpr variable, we can't treat it as a
4092 constant until its initializer is complete in case it's used in
4093 its own initializer. */
4096 }
4098 /* Returns true if DECL could be a symbolic constant variable, depending on
4099 its initializer. */
4101 bool
4103 {
4110 /* A proxy isn't constant. */
4117 else
4122 /* We know the initializer, and it isn't constant. */
4124 else
4126 }
4128 /* Complain that DECL uses a type with no linkage. In C++98 mode this is
4129 called from grokfndecl and grokvardecl; in all modes it is called from
4130 cp_write_global_declarations. */
4132 void
4134 {
4136 /* In C++11 it's ok if the decl is defined. */
4140 /* The type that got us on no_linkage_decls must have gotten a name for
4143 /* The type might end up having a typedef name for linkage purposes. */
4146 {
4154 /* DRs 132, 319 and 389 seem to indicate types with
4155 no linkage can only be used to declare extern "C"
4156 entities. Since it's not always an error in the
4157 ISO C++ 90 Standard, we only issue a warning. */
4159 "with no linkage used to declare variable %q#D with "
4161 else
4164 decl);
4169 }
4171 {
4174 "%q#D, declared using local type "
4176 }
4180 else
4183 }
4185 /* Collect declarations from all namespaces relevant to SOURCE_FILE. */
4187 static void
4189 {
4191 }
4193 /* Clear DECL_EXTERNAL for NODE. */
4195 static bool
4197 {
4200 }
4202 /* Build up the function to run dynamic initializers for thread_local
4203 variables in this translation unit and alias the init functions for the
4204 individual variables to it. */
4206 static void
4208 {
4218 boolean_type_node);
4233 tf_warning_or_error);
4236 boolean_true_node,
4237 tf_warning_or_error));
4239 {
4244 #ifdef ASM_OUTPUT_DEF
4245 /* Output init aliases even with -fno-extern-tls-init. */
4247 {
4251 cgraph_node *alias
4255 }
4256 #endif
4257 }
4263 }
4265 /* We're at the end of compilation, so generate any mangling aliases that
4266 we've been saving up, if DECL is going to be output and ID2 isn't
4267 already taken by another declaration. */
4269 static void
4271 {
4272 /* If there's a declaration already using this mangled name,
4273 don't create a compatibility alias that conflicts. */
4280 /* Don't create an alias to an unreferenced function. */
4292 else
4294 }
4296 /* Note that we might want to emit an alias with the symbol ID2 for DECL at
4297 the end of translation, for compatibility across bugs in the mangling
4298 implementation. */
4300 void
4302 {
4303 #ifdef ASM_OUTPUT_DEF
4306 else
4307 {
4310 }
4311 #endif
4312 }
4314 /* Emit all mangling aliases that were deferred up to this point. */
4316 void
4318 {
4320 {
4324 }
4326 }
4328 /* The entire file is now complete. If requested, dump everything
4329 to a file. */
4331 static void
4333 {
4334 dump_flags_t flags;
4336 {
4339 }
4340 }
4344 /* Check the deallocation functions for CODE to see if we want to warn that
4345 only one was defined. */
4347 static void
4349 {
4355 {
4357 /* We're only interested in usual deallocation functions. */
4362 else
4364 }
4371 }
4373 /* Check the global deallocation functions to see if we want to warn about
4374 defining unsized without sized (or vice versa). */
4376 static void
4378 {
4383 }
4385 /* Earlier we left PTRMEM_CST in variable initializers alone so that we could
4386 look them up when evaluating non-type template parameters. Now we need to
4387 lower them to something the back end can understand. */
4389 static void
4391 {
4394 {
4398 }
4399 }
4401 /* This routine is called at the end of compilation.
4402 Its job is to create all the code needed to initialize and
4403 destroy the global aggregates. We do the destruction
4404 first, since that way we only need to reverse the decls once. */
4406 void
4408 {
4409 tree vars;
4414 tree decl;
4419 /* Bad parse errors. Just forget about it. */
4424 /* This is the point to write out a PCH if we're doing that.
4425 In that case we do not want to do anything else. */
4427 {
4428 /* Mangle all symbols at PCH creation time. */
4436 /* Ensure even the callers don't try to finalize the CU. */
4439 }
4446 /* Handle -fdump-ada-spec[-slim] */
4448 {
4451 else
4455 }
4457 /* FIXME - huh? was input_line -= 1;*/
4459 /* We now have to write out all the stuff we put off writing out.
4460 These include:
4462 o Template specializations that we have not yet instantiated,
4463 but which are needed.
4464 o Initialization and destruction for non-local objects with
4465 static storage duration. (Local objects with static storage
4466 duration are initialized when their scope is first entered,
4467 and are cleaned up via atexit.)
4468 o Virtual function tables.
4470 All of these may cause others to be needed. For example,
4471 instantiating one function may cause another to be needed, and
4472 generating the initializer for an object may cause templates to be
4473 instantiated, etc., etc. */
4477 do
4478 {
4479 tree t;
4480 tree decl;
4484 /* If there are templates that we've put off instantiating, do
4485 them now. */
4489 /* Write out virtual tables as required. Writing out the
4490 virtual table for a template class may cause the
4491 instantiation of members of that class. If we write out
4492 vtables then we remove the class from our list so we don't
4493 have to look at it again. */
4497 {
4500 }
4502 /* Write out needed type info variables. We have to be careful
4503 looping through unemitted decls, because emit_tinfo_decl may
4504 cause other variables to be needed. New elements will be
4505 appended, and we remove from the vector those that actually
4506 get emitted. */
4510 {
4513 }
4515 /* The list of objects with static storage duration is built up
4516 in reverse order. We clear STATIC_AGGREGATES so that any new
4517 aggregates added during the initialization of these will be
4518 initialized in the correct order when we next come around the
4519 loop. */
4523 {
4524 /* We need to start a new initialization function each time
4525 through the loop. That's because we need to know which
4526 vtables have been referenced, and TREE_SYMBOL_REFERENCED
4527 isn't computed until a function is finished, and written
4528 out. That's a deficiency in the back end. When this is
4529 fixed, these initialization functions could all become
4530 inline, with resulting performance improvements. */
4531 tree ssdf_body;
4533 /* Set the line and file, so that it is obviously not from
4534 the source file. */
4538 /* Make sure the back end knows about all the variables. */
4541 /* First generate code to do all the initializations. */
4545 /* Then, generate code to do all the destructions. Do these
4546 in reverse order so that the most recently constructed
4547 variable is the first destroyed. If we're using
4548 __cxa_atexit, then we don't need to do this; functions
4549 were registered at initialization time to destroy the
4550 local statics. */
4552 {
4555 }
4556 else
4559 /* Finish up the static storage duration function for this
4560 round. */
4564 /* All those initializations and finalizations might cause
4565 us to need more inline functions, more template
4566 instantiations, etc. */
4568 ssdf_count++;
4569 /* ??? was: locus_at_end_of_parsing.line++; */
4570 }
4572 /* Now do the same for thread_local variables. */
4575 /* Go through the set of inline functions whose bodies have not
4576 been emitted yet. If out-of-line copies of these functions
4577 are required, emit them. */
4579 {
4580 /* Does it need synthesizing? */
4583 {
4584 /* Even though we're already at the top-level, we push
4585 there again. That way, when we pop back a few lines
4586 hence, all of our state is restored. Otherwise,
4587 finish_function doesn't clean things up, and we end
4588 up with CURRENT_FUNCTION_DECL set. */
4590 /* The decl's location will mark where it was first
4591 needed. Save that so synthesize method can indicate
4592 where it was needed from, in case of error */
4597 }
4607 /* We lie to the back end, pretending that some functions
4608 are not defined when they really are. This keeps these
4609 functions from being put out unnecessarily. But, we must
4610 stop lying when the functions are referenced, or if they
4611 are not comdat since they need to be put out now. If
4612 DECL_INTERFACE_KNOWN, then we have already set
4613 DECL_EXTERNAL appropriately, so there's no need to check
4614 again, and we do not want to clear DECL_EXTERNAL if a
4615 previous call to import_export_decl set it.
4617 This is done in a separate for cycle, because if some
4618 deferred function is contained in another deferred
4619 function later in deferred_fns varray,
4620 rest_of_compilation would skip this function and we
4621 really cannot expand the same function twice. */
4626 {
4632 /* If we mark !DECL_EXTERNAL one of the symbols in some comdat
4633 group, we need to mark all symbols in the same comdat group
4634 that way. */
4642 }
4644 /* If we're going to need to write this function out, and
4645 there's already a body for it, create RTL for it now.
4646 (There might be no body if this is a method we haven't
4647 gotten around to synthesizing yet.) */
4652 {
4653 /* We will output the function; no longer consider it in this
4654 loop. */
4656 /* Generate RTL for this function now that we know we
4657 need it. */
4659 /* If we're compiling -fsyntax-only pretend that this
4660 function has been written out so that we don't try to
4661 expand it again. */
4665 }
4666 }
4671 /* Static data members are just like namespace-scope globals. */
4673 {
4675 /* Don't write it out if we haven't seen a definition. */
4679 /* If this static data member is needed, provide it to the
4680 back end. */
4683 }
4689 retries++;
4690 }
4697 /* All used inline functions must have a definition at this point. */
4699 {
4702 /* If the definition actually was available here, then the
4703 fact that the function was not defined merely represents
4704 that for some reason (use of a template repository,
4705 #pragma interface, etc.) we decided not to emit the
4706 definition here. */
4708 /* Don't complain if the template was defined. */
4712 {
4715 /* Avoid a duplicate warning from check_global_declaration. */
4717 }
4718 }
4720 /* So must decls that use a type with no linkage. */
4726 /* Then, do the Objective-C stuff. This is where all the
4727 Objective-C module stuff gets generated (symtab,
4728 class/protocol/selector lists etc). This must be done after C++
4729 templates, destructors etc. so that selectors used in C++
4730 templates are properly allocated. */
4734 /* We give C linkage to static constructors and destructors. */
4737 /* Generate initialization and destruction functions for all
4738 priorities for which they are required. */
4741 generate_ctor_and_dtor_functions_for_priority,
4744 /* If this is obj-c++ and we need a static init, call
4745 generate_ctor_or_dtor_function. */
4747 DEFAULT_INIT_PRIORITY,
4750 /* We're done with the splay-tree now. */
4754 /* Generate any missing aliases. */
4757 /* We're done with static constructors, so we can go back to "C++"
4758 linkage now. */
4762 {
4766 }
4773 /* The entire file is now complete. If requested, dump everything
4774 to a file. */
4778 {
4781 }
4786 /* Indicate that we're done with front end processing. */
4788 }
4790 /* Perform any post compilation-proper cleanups for the C++ front-end.
4791 This should really go away. No front-end should need to do
4792 anything past the compilation process. */
4794 void
4796 {
4800 {
4801 /* Generate the special constructor initialization function that
4802 calls __VLTRegisterPairs, and give it a very high
4803 initialization priority. This must be done after
4804 finalize_compilation_unit so that we have accurate
4805 information about which vtable will actually be emitted. */
4807 }
4815 }
4817 /* FN is an OFFSET_REF, DOTSTAR_EXPR or MEMBER_REF indicating the
4818 function to call in parse-tree form; it has not yet been
4819 semantically analyzed. ARGS are the arguments to the function.
4820 They have already been semantically analyzed. This may change
4821 ARGS. */
4823 tree
4825 tsubst_flags_t complain)
4826 {
4827 tree orig_fn;
4829 tree expr;
4830 tree object;
4836 {
4845 /* Transform the arguments and add the implicit "this"
4846 parameter. That must be done before the FN is transformed
4847 because we depend on the form of FN. */
4851 {
4855 }
4856 /* Now that the arguments are done, transform FN. */
4858 }
4860 /* A qualified name corresponding to a bound pointer-to-member is
4861 represented as an OFFSET_REF:
4863 struct B { void g(); };
4864 void (B::*p)();
4865 void B::g() { (this->*p)(); } */
4867 {
4871 complain);
4873 }
4877 else
4886 }
4889 void
4891 {
4896 {
4900 {
4903 }
4904 }
4905 }
4907 /* Return true if function DECL can be inlined. This is used to force
4908 instantiation of methods that might be interesting for inlining. */
4909 bool
4911 {
4917 /* When optimizing, we might inline everything when flatten
4918 attribute or heuristics inlining for size or autoinlining
4919 is used. */
4921 }
4923 /* Normally, we can wait until instantiation-time to synthesize DECL.
4924 However, if DECL is a static data member initialized with a constant
4925 or a constexpr function, we need it right now because a reference to
4926 such a data member or a call to such function is not value-dependent.
4927 For a function that uses auto in the return type, we need to instantiate
4928 it to find out its type. For OpenMP user defined reductions, we need
4929 them instantiated for reduction clauses which inline them by hand
4930 directly. */
4932 static void
4934 {
4943 {
4944 /* Instantiating a function will result in garbage collection. We
4945 must treat this situation as if we were within the body of a
4946 function so as to avoid collecting live data only referenced from
4947 the stack (such as overload resolution candidates). */
4952 }
4953 }
4955 /* Mark DECL (either a _DECL or a BASELINK) as "used" in the program.
4956 If DECL is a specialization or implicitly declared class member,
4957 generate the actual definition. Return false if something goes
4958 wrong, true otherwise. */
4960 bool
4962 {
4963 /* If DECL is a BASELINK for a single function, then treat it just
4964 like the DECL for the function. Otherwise, if the BASELINK is
4965 for an overloaded function, we don't know which function was
4966 actually used until after overload resolution. */
4968 {
4973 }
4975 /* Set TREE_USED for the benefit of -Wunused. */
4977 /* And for structured bindings also the underlying decl. */
4987 /* Mark enumeration types as used. */
4996 {
5000 /* We mark a lambda conversion op as deleted if we can't
5001 generate it properly; see maybe_add_lambda_conv_op. */
5004 {
5008 }
5010 }
5016 /* We can only check DECL_ODR_USED on variables or functions with
5017 DECL_LANG_SPECIFIC set, and these are also the only decls that we
5018 might need special handling for. */
5022 {
5027 }
5029 /* We only want to do this processing once. We don't need to keep trying
5030 to instantiate inline templates, because unit-at-a-time will make sure
5031 we get them compiled before functions that want to inline them. */
5035 /* Normally, we can wait until instantiation-time to synthesize DECL.
5036 However, if DECL is a static data member initialized with a constant
5037 or a constexpr function, we need it right now because a reference to
5038 such a data member or a call to such function is not value-dependent.
5039 For a function that uses auto in the return type, we need to instantiate
5040 it to find out its type. For OpenMP user defined reductions, we need
5041 them instantiated for reduction clauses which inline them by hand
5042 directly. */
5048 /* Check this too in case we're within instantiate_non_dependent_expr. */
5057 {
5061 }
5063 /* If we don't need a value, then we don't need to synthesize DECL. */
5071 /* DR 757: A type without linkage shall not be used as the type of a
5072 variable or function with linkage, unless
5073 o the variable or function has extern "C" linkage (7.5 [dcl.link]), or
5074 o the variable or function is not used (3.2 [basic.def.odr]) or is
5075 defined in the same translation unit. */
5082 {
5084 /* There's no way to define a local extern, and adding it to
5085 the vector interferes with GC, so give an error now. */
5087 else
5089 }
5093 /* Remember it, so we can check it was defined. */
5096 /* Is it a synthesized method that needs to be synthesized? */
5100 /* A function defaulted outside the class is synthesized either by
5101 cp_finish_decl or instantiate_decl. */
5104 {
5105 /* Defer virtual destructors so that thunks get the right
5106 linkage. */
5108 {
5111 }
5113 /* Remember the current location for a function we will end up
5114 synthesizing. Then we can inform the user where it was
5115 required in the case of error. */
5118 /* Synthesizing an implicitly defined member function will result in
5119 garbage collection. We must treat this situation as if we were
5120 within the body of a function so as to avoid collecting live data
5121 on the stack (such as overload resolution candidates).
5123 We could just let cp_write_global_declarations handle synthesizing
5124 this function by adding it to deferred_fns, but doing
5125 it at the use site produces better error messages. */
5129 /* If this is a synthesized method we don't need to
5130 do the instantiation test below. */
5131 }
5137 /* If this is a function or variable that is an instance of some
5138 template, we now know that we will need to actually do the
5139 instantiation. We check that DECL is not an explicit
5140 instantiation because that is not checked in instantiate_decl.
5142 We put off instantiating functions in order to improve compile
5143 times. Maintaining a stack of active functions is expensive,
5144 and the inliner knows to instantiate any functions it might
5145 need. Therefore, we always try to defer instantiation. */
5146 {
5151 }
5154 }
5156 bool
5158 {
5160 }
5162 tree
5164 {
5166 }
5168 tree
5170 {
5171 tree fn;
5179 }