| blob | 9c351fda44d12c52d16ec999ab1a01922163d4c3 |
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. */
54 /* This structure contains information about the initializations
55 and/or destructions required for a particular priority level. */
57 /* Nonzero if there have been any initializations at this priority
58 throughout the translation unit. */
60 /* Nonzero if there have been any destructions at this priority
61 throughout the translation unit. */
85 /* A list of static class variables. This is needed, because a
86 static class variable can be declared inside the class without
87 an initializer, and then initialized, statically, outside the class. */
90 /* A list of functions which were declared inline, but which we
91 may need to emit outline anyway. */
94 /* A list of decls that use types with no linkage, which we need to make
95 sure are defined. */
98 /* A vector of alternating decls and identifiers, where the latter
99 is to be an alias for the former if the former is defined. */
102 /* Nonzero if we're done parsing and into end-of-file activities. */
106 /* True if note_mangling_alias should enqueue mangling aliases for
107 later generation, rather than emitting them right away. */
110 \f
112 /* Return a member function type (a METHOD_TYPE), given FNTYPE (a
113 FUNCTION_TYPE), CTYPE (class type), and QUALS (the cv-qualifiers
114 that apply to the function). */
116 tree
118 cp_ref_qualifier rqual)
119 {
120 tree raises;
121 tree attrs;
150 }
152 /* Return a variant of FNTYPE, a FUNCTION_TYPE or METHOD_TYPE, with its
153 return type changed to NEW_RET. */
155 tree
157 {
158 tree newtype;
171 {
176 }
177 else
178 newtype = build_method_type_directly
190 }
192 /* Build a PARM_DECL with NAME and TYPE, and set DECL_ARG_TYPE
193 appropriately. */
195 tree
197 {
200 /* DECL_ARG_TYPE is only used by the back end and the back end never
201 sees templates. */
206 }
208 /* Returns a PARM_DECL for a parameter of the indicated TYPE, with the
209 indicated NAME. */
211 tree
213 {
216 /* All our artificial parms are implicitly `const'; they cannot be
217 assigned to. */
220 }
222 /* Constructors for types with virtual baseclasses need an "in-charge" flag
223 saying whether this constructor is responsible for initialization of
224 virtual baseclasses or not. All destructors also need this "in-charge"
225 flag, which additionally determines whether or not the destructor should
226 free the memory for the object.
228 This function adds the "in-charge" flag to member function FN if
229 appropriate. It is called from grokclassfn and tsubst.
230 FN must be either a constructor or destructor.
232 The in-charge flag follows the 'this' parameter, and is followed by the
233 VTT parm (if any), then the user-written parms. */
235 void
237 {
240 /* If we've already add the in-charge parameter don't do it again. */
244 /* When processing templates we can't know, in general, whether or
245 not we're going to have virtual baseclasses. */
249 /* We don't need an in-charge parameter for constructors that don't
250 have virtual bases. */
261 /* If this is a subobject constructor or destructor, our caller will
262 pass us a pointer to our VTT. */
264 {
267 /* First add it to DECL_ARGUMENTS between 'this' and the real args... */
271 /* ...and then to TYPE_ARG_TYPES. */
275 }
277 /* Then add the in-charge parm (before the VTT parm). */
283 /* Insert our new parameter(s) into the list. */
286 /* And rebuild the function type. */
288 arg_types);
293 fntype = (cp_build_type_attribute_variant
297 /* Now we've got the in-charge parameter. */
299 }
301 /* Classes overload their constituent function names automatically.
302 When a function name is declared in a record structure,
303 its name is changed to it overloaded name. Since names for
304 constructors and destructors can conflict, we place a leading
305 '$' for destructors.
307 CNAME is the name of the class we are grokking for.
309 FUNCTION is a FUNCTION_DECL. It was created by `grokdeclarator'.
311 FLAGS contains bits saying what's special about today's
312 arguments. DTOR_FLAG == DESTRUCTOR.
314 If FUNCTION is a destructor, then we must add the `auto-delete' field
315 as a second parameter. There is some hair associated with the fact
316 that we must "declare" this variable in the manner consistent with the
317 way the rest of the arguments were declared.
319 QUALS are the qualifiers for the this pointer. */
321 void
323 {
326 /* Even within an `extern "C"' block, members get C++ linkage. See
327 [dcl.link] for details. */
331 {
335 }
344 }
346 /* Create an ARRAY_REF, checking for the user doing things backwards
347 along the way. DECLTYPE_P is for N3276, as in the parser. */
349 tree
352 {
353 tree type;
354 tree expr;
363 {
370 }
376 /* If they have an `operator[]', use that. */
378 {
384 }
385 else
386 {
389 /* Otherwise, create an ARRAY_REF for a pointer or array type.
390 It is a little-known fact that, if `a' is an array and `i' is
391 an int, you can write `i[a]', which means the same thing as
392 `a[i]'. */
395 else
400 else
415 else
416 {
420 }
426 }
428 {
435 }
437 }
439 /* Given the cast expression EXP, checking out its validity. Either return
440 an error_mark_node if there was an unavoidable error, return a cast to
441 void for trying to delete a pointer w/ the value 0, or return the
442 call to delete. If DOING_VEC is true, we handle things differently
443 for doing an array delete.
444 Implements ARM $5.3.4. This is called from the parser. */
446 tree
448 tsubst_flags_t complain)
449 {
456 {
462 }
464 /* An array can't have been allocated by new, so complain. */
471 {
475 }
479 /* As of Valley Forge, you can delete a pointer to const. */
481 /* You can't delete functions. */
483 {
487 }
489 /* Deleting ptr to void is undefined behavior [expr.delete/3]. */
491 {
494 }
496 /* Deleting a pointer with the value zero is valid and has no effect. */
502 sfk_deleting_destructor,
504 else
507 complain);
508 }
510 /* Report an error if the indicated template declaration is not the
511 sort of thing that should be a member template. */
513 void
515 {
516 tree decl;
525 {
526 /* The parser rejects template declarations in local classes
527 (with the exception of generic lambdas). */
529 /* The parser rejects any use of virtual in a function template. */
533 /* The debug-information generating code doesn't know what to do
534 with member templates. */
536 }
539 else
541 }
543 /* Sanity check: report error if this function FUNCTION is not
544 really a member of the class (CTYPE) it is supposed to belong to.
545 TEMPLATE_PARMS is used to specify the template parameters of a member
546 template passed as FUNCTION_DECL. If the member template is passed as a
547 TEMPLATE_DECL, it can be NULL since the parameters can be extracted
548 from the declaration. If the function is not a function template, it
549 must be NULL.
550 It returns the original declaration for the function, NULL_TREE if
551 no declaration was found, error_mark_node if an error was emitted. */
553 tree
555 {
558 tree pushed_scope;
564 /* Since this is a specialization of a member template,
565 we're not going to find the declaration in the class.
566 For example, in:
568 struct S { template <typename T> void f(T); };
569 template <> void S::f(int);
571 we're not going to find `S::f(int)', but there's no
572 reason we should, either. We let our callers know we didn't
573 find the method, but we don't complain. */
576 /* Basic sanity check: for a template function, the template parameters
577 either were not passed, or they are the same of DECL_TEMPLATE_PARMS. */
579 {
583 {
587 }
589 }
591 /* OK, is this a definition of a member template? */
594 /* [temp.mem]
596 A destructor shall not be a member template. */
598 {
601 }
603 /* We must enter the scope here, because conversion operators are
604 named by target type, and type equivalence relies on typenames
605 resolving within the scope of CTYPE. */
609 {
617 {
624 /* We cannot simply call decls_match because this doesn't
625 work for static member functions that are pretending to
626 be methods, and because the name may have been changed by
627 asm("new_name"). */
629 /* Get rid of the this parameter on functions that become
630 static. */
635 /* A member template definition only matches a member template
636 declaration. */
640 /* ref-qualifier or absence of same must match. */
645 // Include constraints in the match.
649 /* While finding a match, same types and params are not enough
650 if the function is versioned. Also check version ("target")
651 attributes. */
656 && (!is_template
666 }
668 {
672 }
683 {
688 {
690 {
693 {
696 }
697 }
698 else
700 }
705 else
708 }
709 }
712 else
719 }
721 /* DECL is a function with vague linkage. Remember it so that at the
722 end of the translation unit we can decide whether or not to emit
723 it. */
725 void
727 {
730 }
732 /* As above, but for variable template instantiations. */
734 void
736 {
738 }
740 /* We have just processed the DECL, which is a static data member.
741 The other parameters are as for cp_finish_decl. */
743 void
746 tree asmspec_tree,
748 {
751 /* We cannot call pushdecl here, because that would fill in the
752 TREE_CHAIN of our decl. Instead, we modify cp_finish_decl to do
753 the right thing, namely, to put this decl out straight away. */
759 /* We already complained about the template definition. */
763 else
767 {
773 }
782 }
784 /* DECLARATOR and DECLSPECS correspond to a class member. The other
785 parameters are as for cp_finish_decl. Return the DECL for the
786 class member declared. */
788 tree
792 tree asmspec_tree,
793 tree attrlist)
794 {
795 tree value;
798 tree name;
808 /* friend or constructor went bad. */
814 {
817 }
819 /* Pass friendly classes back. */
827 {
829 {
832 }
837 value);
838 }
840 /* Stash away type declarations. */
842 {
847 {
850 /* If this is a typedef that names the class for linkage purposes
851 (7.1.3p8), apply any attributes directly to the type. */
857 }
864 /* It's important that push_template_decl below follows
865 set_underlying_type above so that the created template
866 carries the properly set type of VALUE. */
872 }
877 {
880 }
886 {
888 {
890 {
894 }
896 {
898 {
902 }
903 }
907 {
912 else
914 value);
915 }
916 else
917 {
921 value);
922 else
924 value);
925 }
926 }
931 }
933 /* Pass friend decls back. */
939 /* Need to set this before push_template_decl. */
944 {
948 }
955 else
959 {
984 /* Pass friends back this way. */
993 }
995 }
997 /* Like `grokfield', but for bitfields.
998 WIDTH is non-NULL for bit fields only, and is an INTEGER_CST node. */
1000 tree
1003 tree attrlist)
1004 {
1012 /* Pass friendly classes back. */
1019 {
1022 }
1025 {
1028 }
1030 /* Usually, finish_struct_1 catches bitfields with invalid types.
1031 But, in the case of bitfields with function type, we confuse
1032 ourselves into thinking they are member functions, so we must
1033 check here. */
1035 {
1039 }
1042 {
1046 }
1049 {
1052 }
1056 {
1057 /* The width must be an integer type. */
1062 else
1063 {
1066 }
1067 }
1075 }
1077 \f
1078 /* Returns true iff ATTR is an attribute which needs to be applied at
1079 instantiation time rather than template definition time. */
1081 static bool
1083 {
1087 tree arg;
1090 /* Unknown attribute. */
1093 /* Attribute weak handling wants to write out assembly right away. */
1097 /* Attribute unused is applied directly, as it appertains to
1098 decls. */
1102 /* Attribute tls_model wants to modify the symtab. */
1106 /* #pragma omp declare simd attribute needs to be always deferred. */
1111 /* An attribute pack is clearly dependent. */
1115 /* If any of the arguments are dependent expressions, we can't evaluate
1116 the attribute until instantiation time. */
1118 {
1121 /* If the first attribute argument is an identifier, only consider
1122 second and following arguments. Attributes like mode, format,
1123 cleanup and several target specific attributes aren't late
1124 just because they have an IDENTIFIER_NODE as first argument. */
1132 }
1137 {
1140 /* We can't apply any attributes to a completely unknown type until
1141 instantiation time. */
1147 /* Also defer most attributes on dependent types. This is not
1148 necessary in all cases, but is the better default. */
1150 /* But some attributes specifically apply to templates. */
1155 else
1157 }
1158 else
1160 }
1162 /* ATTR_P is a list of attributes. Remove any attributes which need to be
1163 applied at instantiation time and return them. If IS_DEPENDENT is true,
1164 the declaration itself is dependent, so all attributes should be applied
1165 at instantiation time. */
1167 static tree
1169 {
1178 {
1180 {
1186 }
1187 else
1189 }
1192 }
1194 /* Remove any late attributes from the list in ATTR_P and attach them to
1195 DECL_P. */
1197 static void
1199 {
1211 else
1216 /* Merge the late attributes at the beginning with the attribute
1217 list. */
1222 {
1223 /* We've added new attributes directly to the main variant, so
1224 now we need to update all of the other variants to include
1225 these new attributes. */
1226 tree variant;
1229 {
1232 }
1233 }
1234 }
1236 /* True if ATTRS contains any dependent attributes that affect type
1237 identity. */
1239 bool
1241 {
1244 {
1248 }
1250 }
1252 /* Return true iff ATTRS are acceptable attributes to be applied in-place
1253 to a typedef which gives a previously unnamed class or enum a name for
1254 linkage purposes. */
1256 bool
1258 {
1260 {
1264 }
1266 }
1268 /* Like reconstruct_complex_type, but handle also template trees. */
1270 tree
1272 {
1277 {
1281 }
1283 {
1287 }
1289 {
1292 /* Don't call cp_build_qualified_type on ARRAY_TYPEs, the
1293 element type qualification will be handled by the recursive
1294 cp_reconstruct_complex_type call and cp_build_qualified_type
1295 for ARRAY_TYPEs changes the element type. */
1297 }
1299 {
1306 }
1308 {
1311 /* The build_method_type_directly() routine prepends 'this' to argument list,
1312 so we must compensate by getting rid of it. */
1313 outer
1314 = build_method_type_directly
1317 }
1319 {
1322 }
1323 else
1334 }
1336 /* Replaces any constexpr expression that may be into the attributes
1337 arguments with their reduced value. */
1339 static void
1341 {
1345 tree attr;
1347 {
1348 tree arg;
1350 {
1354 }
1355 }
1356 }
1358 /* Return true if TYPE is an OpenMP mappable type. */
1359 bool
1361 {
1362 /* Mappable type has to be complete. */
1365 /* Arrays have mappable type if the elements have mappable type. */
1368 /* A mappable type cannot contain virtual members. */
1371 /* All data members must be non-static. */
1373 {
1374 tree field;
1378 /* All fields must have mappable types. */
1382 }
1384 }
1386 /* Like decl_attributes, but handle C++ complexity. */
1388 void
1390 {
1395 /* Add implicit "omp declare target" attribute if requested. */
1400 {
1410 else
1413 }
1416 {
1421 }
1429 {
1430 attributes
1434 }
1435 else
1441 /* Propagate deprecation out to the template. */
1444 {
1450 }
1451 }
1452 \f
1453 /* Walks through the namespace- or function-scope anonymous union
1454 OBJECT, with the indicated TYPE, building appropriate VAR_DECLs.
1455 Returns one of the fields for use in the mangled name. */
1457 static tree
1459 {
1461 tree field;
1463 /* Rather than write the code to handle the non-union case,
1464 just give an error. */
1466 {
1469 }
1474 {
1475 tree decl;
1476 tree ref;
1481 {
1483 "%q#D invalid; an anonymous union can only "
1486 }
1498 else
1503 {
1504 tree base;
1520 }
1523 else
1528 }
1531 }
1533 /* Finish off the processing of a UNION_TYPE structure. If the union is an
1534 anonymous union, then all members must be laid out together. PUBLIC_P
1535 is nonzero if this union is not declared static. */
1537 void
1539 {
1540 tree type;
1541 tree main_decl;
1550 /* The VAR_DECL's context is the same as the TYPE's context. */
1557 {
1560 }
1566 {
1569 }
1572 {
1573 /* Use main_decl to set the mangled name. */
1579 }
1583 }
1584 \f
1585 /* Auxiliary functions to make type signatures for
1586 `operator new' and `operator delete' correspond to
1587 what compiler will be expecting. */
1589 tree
1591 {
1598 {
1601 }
1604 {
1606 {
1607 /* [basic.stc.dynamic.allocation]
1609 The first parameter shall not have an associated default
1610 argument. */
1613 /* Throw away the default argument. */
1615 }
1618 {
1621 }
1622 }
1623 else
1631 {
1634 /* Fall through. */
1636 type = build_exception_variant
1639 /* Fall through. */
1641 }
1643 }
1645 tree
1647 {
1654 {
1657 }
1661 {
1666 ptr_type_node);
1667 }
1669 {
1672 /* Fall through. */
1674 type = build_exception_variant
1677 /* Fall through. */
1679 }
1682 }
1683 \f
1684 /* DECL is a VAR_DECL for a vtable: walk through the entries in the vtable
1685 and mark them as needed. */
1687 static void
1689 {
1690 tree fnaddr;
1693 /* It's OK for the vtable to refer to deprecated virtual functions. */
1698 {
1699 tree fn;
1705 /* This entry is an offset: a virtual base class offset, a
1706 virtual call offset, an RTTI offset, etc. */
1711 /* When we don't have vcall offsets, we output thunks whenever
1712 we output the vtables that contain them. With vcall offsets,
1713 we know all the thunks we'll need when we emit a virtual
1714 function, so we emit the thunks there instead. */
1718 }
1719 }
1721 /* Set DECL up to have the closest approximation of "initialized common"
1722 linkage available. */
1724 void
1726 {
1731 /* We can just emit function and compiler-generated variables
1732 statically; having multiple copies is (for the most part) only
1733 a waste of space.
1735 There are two correctness issues, however: the address of a
1736 template instantiation with external linkage should be the
1737 same, independent of what translation unit asks for the
1738 address, and this will not hold when we emit multiple copies of
1739 the function. However, there's little else we can do.
1741 Also, by default, the typeinfo implementation assumes that
1742 there will be only one copy of the string used as the name for
1743 each type. Therefore, if weak symbols are unavailable, the
1744 run-time library should perform a more conservative check; it
1745 should perform a string comparison, rather than an address
1746 comparison. */
1748 else
1749 {
1750 /* Static data member template instantiations, however, cannot
1751 have multiple copies. */
1756 {
1759 }
1761 {
1762 /* We can't do anything useful; leave vars for explicit
1763 instantiation. */
1766 }
1767 }
1771 }
1773 /* For win32 we also want to put explicit instantiations in
1774 linkonce sections, so that they will be merged with implicit
1775 instantiations; otherwise we get duplicate symbol errors.
1776 For Darwin we do not want explicit instantiations to be
1777 linkonce. */
1779 void
1781 {
1782 /* We used to say that this was not necessary on targets that support weak
1783 symbols, because the implicit instantiations will defer to the explicit
1784 one. However, that's not actually the case in SVR4; a strong definition
1785 after a weak one is an error. Also, not making explicit
1786 instantiations one_only means that we can end up with two copies of
1787 some template instantiations. */
1791 /* We can't set DECL_COMDAT on functions, or cp_finish_file will think
1792 we can get away with not emitting them if they aren't used. We need
1793 to for variables so that cp_finish_decl will update their linkage,
1794 because their DECL_INITIAL may not have been set properly yet. */
1799 {
1803 {
1806 /* Mark it needed so we don't forget to emit it. */
1809 }
1810 }
1811 }
1813 /* Returns true iff DECL, a FUNCTION_DECL or VAR_DECL, has vague linkage.
1814 This predicate will give the right answer during parsing of the
1815 function, which other tests may not. */
1817 bool
1819 {
1821 {
1822 /* maybe_thunk_body clears TREE_PUBLIC on the maybe-in-charge 'tor
1823 variants, check one of the "clones" for the real linkage. */
1832 }
1833 /* Unfortunately, import_export_decl has not always been called
1834 before the function is processed, so we cannot simply check
1835 DECL_COMDAT. */
1844 /* A local static in an inline effectively has vague linkage. */
1847 else
1849 }
1851 /* Determine whether or not we want to specifically import or export CTYPE,
1852 using various heuristics. */
1854 static void
1856 {
1857 /* -1 for imported, 1 for exported. */
1860 /* It only makes sense to call this function at EOF. The reason is
1861 that this function looks at whether or not the first non-inline
1862 non-abstract virtual member function has been defined in this
1863 translation unit. But, we can't possibly know that until we've
1864 seen the entire translation unit. */
1870 /* If MULTIPLE_SYMBOL_SPACES is set and we saw a #pragma interface,
1871 we will have CLASSTYPE_INTERFACE_ONLY set but not
1872 CLASSTYPE_INTERFACE_KNOWN. In that case, we don't want to use this
1873 heuristic because someone will supply a #pragma implementation
1874 elsewhere, and deducing it here would produce a conflict. */
1884 /* For a template class, without -fimplicit-templates, check the
1885 repository. If the virtual table is assigned to this
1886 translation unit, then export the class; otherwise, import
1887 it. */
1890 {
1891 /* The ABI specifies that the virtual table and associated
1892 information are emitted with the key method, if any. */
1894 /* If weak symbol support is not available, then we must be
1895 careful not to emit the vtable when the key function is
1896 inline. An inline function can be defined in multiple
1897 translation units. If we were to emit the vtable in each
1898 translation unit containing a definition, we would get
1899 multiple definition errors at link-time. */
1902 }
1904 /* When MULTIPLE_SYMBOL_SPACES is set, we cannot count on seeing
1905 a definition anywhere else. */
1909 /* Allow back ends the chance to overrule the decision. */
1914 {
1917 }
1918 }
1920 /* Return true if VAR has already been provided to the back end; in that
1921 case VAR should not be modified further by the front end. */
1922 static bool
1924 {
1926 }
1928 /* DECL is a VAR_DECL or FUNCTION_DECL which, for whatever reason,
1929 must be emitted in this translation unit. Mark it as such. */
1931 void
1933 {
1936 {
1937 /* Extern inline functions don't become needed when referenced.
1938 If we know a method will be emitted in other TU and no new
1939 functions can be marked reachable, just use the external
1940 definition. */
1944 /* #pragma interface and -frepo code can call mark_needed for
1945 maybe-in-charge 'tors; mark the clones as well. */
1946 tree clone;
1949 }
1951 {
1953 /* C++ frontend use mark_decl_references to force COMDAT variables
1954 to be output that might appear dead otherwise. */
1956 }
1957 }
1959 /* DECL is either a FUNCTION_DECL or a VAR_DECL. This function
1960 returns true if a definition of this entity should be provided in
1961 this object file. Callers use this function to determine whether
1962 or not to let the back end know that a definition of DECL is
1963 available in this translation unit. */
1965 bool
1967 {
1969 /* This function should only be called at the end of the translation
1970 unit. We cannot be sure of whether or not something will be
1971 COMDAT until that point. */
1974 /* All entities with external linkage that are not COMDAT/EXTERN should be
1975 emitted; they may be referred to from other object files. */
1978 /* Functions marked "dllexport" must be emitted so that they are
1979 visible to other DLLs. */
1984 /* When not optimizing, do not bother to produce definitions for extern
1985 symbols. */
1994 /* If this entity was used, let the back end see it; it will decide
1995 whether or not to emit it into the object file. */
1998 /* Virtual functions might be needed for devirtualization. */
2003 /* Otherwise, DECL does not need to be emitted -- yet. A subsequent
2004 reference to DECL might cause it to be emitted later. */
2006 }
2008 /* If necessary, write out the vtables for the dynamic class CTYPE.
2009 Returns true if any vtables were emitted. */
2011 static bool
2013 {
2014 tree vtbl;
2015 tree primary_vtbl;
2019 /* If the vtables for this class have already been emitted there is
2020 nothing more to do. */
2024 /* Ignore dummy vtables made by get_vtable_decl. */
2028 /* On some targets, we cannot determine the key method until the end
2029 of the translation unit -- which is when this function is
2030 called. */
2034 /* See if any of the vtables are needed. */
2036 {
2040 }
2042 {
2043 /* If the references to this class' vtables are optimized away,
2044 still emit the appropriate debugging information. See
2045 dfs_debug_mark. */
2050 }
2052 /* The ABI requires that we emit all of the vtables if we emit any
2053 of them. */
2055 {
2056 /* Mark entities references from the virtual table as used. */
2060 {
2063 LOOKUP_NORMAL);
2065 /* It had better be all done at compile-time. */
2067 }
2069 /* Write it out. */
2073 /* Because we're only doing syntax-checking, we'll never end up
2074 actually marking the variable as written. */
2078 {
2083 }
2084 }
2086 /* Since we're writing out the vtable here, also write the debug
2087 info. */
2091 }
2093 /* A special return value from type_visibility meaning internal
2094 linkage. */
2098 /* walk_tree helper function for type_visibility. */
2100 static tree
2102 {
2105 {
2107 }
2110 {
2113 }
2118 }
2120 /* Returns the visibility of TYPE, which is the minimum visibility of its
2121 component types. */
2123 static int
2125 {
2129 }
2131 /* Limit the visibility of DECL to VISIBILITY, if not explicitly
2132 specified (or if VISIBILITY is static). If TMPL is true, this
2133 constraint is for a template argument, and takes precedence
2134 over explicitly-specified visibility on the template. */
2136 static void
2138 {
2140 {
2141 /* extern "C" declarations aren't affected by the anonymous
2142 namespace. */
2144 {
2150 {
2155 }
2159 }
2160 }
2163 {
2165 /* This visibility was not specified. */
2167 }
2168 }
2170 /* Constrain the visibility of DECL based on the visibility of its template
2171 arguments. */
2173 static void
2175 {
2176 /* If this is a template instantiation, check the innermost
2177 template args for visibility constraints. The outer template
2178 args are covered by the class check. */
2182 {
2188 else
2189 {
2197 {
2200 else
2202 }
2203 }
2206 }
2207 }
2209 /* Like c_determine_visibility, but with additional C++-specific
2210 behavior.
2212 Function-scope entities can rely on the function's visibility because
2213 it is set in start_preparsed_function.
2215 Class-scope entities cannot rely on the class's visibility until the end
2216 of the enclosing class definition.
2218 Note that because namespaces have multiple independent definitions,
2219 namespace visibility is handled elsewhere using the #pragma visibility
2220 machinery rather than by decorating the namespace declaration.
2222 The goal is for constraints from the type to give a diagnostic, and
2223 other constraints to be applied silently. */
2225 void
2227 {
2228 /* Remember that all decls get VISIBILITY_DEFAULT when built. */
2230 /* Only relevant for names with external linkage. */
2234 /* Cloned constructors and destructors get the same visibility as
2235 the underlying function. That should be set up in
2236 maybe_clone_body. */
2242 /* The decl may be a template instantiation, which could influence
2243 visibilty. */
2246 {
2248 {
2251 }
2254 }
2258 /* If DECL is a member of a class, visibility specifiers on the
2259 class can influence the visibility of the DECL. */
2263 else
2264 {
2265 /* Not a class member. */
2267 /* Virtual tables have DECL_CONTEXT set to their associated class,
2268 so they are automatically handled above. */
2273 {
2274 /* Local statics and classes get the visibility of their
2275 containing function by default, except that
2276 -fvisibility-inlines-hidden doesn't affect them. */
2279 {
2283 }
2284 else
2285 {
2289 {
2293 }
2294 else
2295 {
2299 }
2300 }
2302 /* Local classes in templates have CLASSTYPE_USE_TEMPLATE set,
2303 but have no TEMPLATE_INFO. Their containing template
2304 function does, and the local class could be constrained
2305 by that. */
2308 }
2311 {
2312 /* Under -fvisibility-ms-compat, types are visible by default,
2313 even though their contents aren't. */
2320 else
2322 }
2324 {
2325 /* tinfo visibility is based on the type it's for. */
2326 constrain_visibility
2329 /* Give the target a chance to override the visibility associated
2330 with DECL. */
2336 }
2338 /* Template instantiations and specializations get visibility based
2341 {
2344 else
2345 {
2346 /* Set default visibility to whatever the user supplied with
2347 #pragma GCC visibility or a namespace visibility attribute. */
2350 }
2351 }
2352 }
2355 {
2356 /* If the specialization doesn't specify visibility, use the
2357 visibility from the template. */
2365 {
2369 {
2373 else
2374 {
2378 }
2379 }
2382 /* Template argument visibility outweighs #pragma or namespace
2383 visibility, but not an explicit attribute. */
2385 {
2388 {
2389 /* A class template member with explicit visibility
2390 overrides the class visibility, so we need to apply
2391 all the levels of template args directly. */
2394 {
2397 }
2398 }
2400 /* Limit visibility based on its template arguments. */
2402 }
2403 }
2404 }
2410 /* Names in an anonymous namespace get internal linkage.
2411 This might change once we implement export. */
2414 {
2415 /* Propagate anonymity from type to decl. */
2420 }
2422 /* DR 757: A type without linkage shall not be used as the type of a
2423 variable or function with linkage, unless
2424 o the variable or function has extern "C" linkage (7.5 [dcl.link]), or
2425 o the variable or function is not used (3.2 [basic.def.odr]) or is
2426 defined in the same translation unit.
2428 Since non-extern "C" decls need to be defined in the same
2429 translation unit, we can make the type internal. */
2432 /* If visibility changed and DECL already has DECL_RTL, ensure
2433 symbol flags are updated. */
2440 }
2442 /* By default, static data members and function members receive
2443 the visibility of their containing class. */
2445 static void
2447 {
2453 else
2454 {
2455 /* Default to the class visibility. */
2459 }
2461 /* Give the target a chance to override the visibility associated
2462 with DECL. */
2466 /* Construction virtual tables are not exported because
2467 they cannot be referred to from other object files;
2468 their name is not standardized by the ABI. */
2474 }
2476 /* Returns true iff DECL is an inline that should get hidden visibility
2477 because of -fvisibility-inlines-hidden. */
2479 static bool
2481 {
2483 /* Don't do this for inline templates; specializations might not be
2484 inline, and we don't want them to inherit the hidden
2485 visibility. We'll set it here for all inline instantiations. */
2486 && !processing_template_decl
2491 }
2493 /* Constrain the visibility of a class TYPE based on the visibility of its
2494 field types. Warn if any fields require lesser visibility. */
2496 void
2498 {
2499 tree binfo;
2500 tree t;
2509 /* Don't warn about visibility if the class has explicit visibility. */
2515 {
2520 {
2522 {
2525 {
2530 else
2534 }
2535 else
2539 }
2540 }
2547 }
2551 {
2555 {
2557 {
2560 {
2565 else
2569 }
2570 else
2574 }
2575 }
2581 }
2582 }
2584 /* Functions for adjusting the visibility of a tagged type and its nested
2585 types and declarations when it gets a name for linkage purposes from a
2586 typedef. */
2591 /* First reset the visibility of all the types. */
2593 static void
2595 {
2600 }
2601 static void
2603 {
2605 }
2607 /* Then reset the visibility of any static data members or member
2608 functions that use those types. */
2610 static void
2612 {
2621 }
2622 static void
2624 {
2626 {
2628 {
2633 }
2635 {
2641 }
2643 {
2647 }
2649 {
2653 {
2654 /* Also update its name, for cxx_dwarf_name. */
2658 }
2659 }
2662 }
2663 }
2664 static void
2666 {
2668 }
2669 void
2671 {
2674 }
2676 /* Set up our initial idea of what the linkage of DECL should be. */
2678 void
2680 {
2682 /* We've already made a decision as to how this function will
2685 {
2688 {
2692 /* A non-template inline function with external linkage will
2693 always be COMDAT. As we must eventually determine the
2694 linkage of all functions, and as that causes writes to
2695 the data mapped in from the PCH file, it's advantageous
2696 to mark the functions at this point. */
2700 {
2701 /* This function must have external linkage, as
2702 otherwise DECL_INTERFACE_KNOWN would have been
2703 set. */
2707 }
2708 }
2711 }
2712 }
2714 /* DECL is a FUNCTION_DECL or VAR_DECL. If the object file linkage
2715 for DECL has not already been determined, do so now by setting
2716 DECL_EXTERNAL, DECL_COMDAT and other related flags. Until this
2717 function is called entities with vague linkage whose definitions
2718 are available must have TREE_PUBLIC set.
2720 If this function decides to place DECL in COMDAT, it will set
2721 appropriate flags -- but will not clear DECL_EXTERNAL. It is up to
2722 the caller to decide whether or not to clear DECL_EXTERNAL. Some
2723 callers defer that decision until it is clear that DECL is actually
2724 required. */
2726 void
2728 {
2737 /* We cannot determine what linkage to give to an entity with vague
2738 linkage until the end of the file. For example, a virtual table
2739 for a class will be defined if and only if the key method is
2740 defined in this translation unit. As a further example, consider
2741 that when compiling a translation unit that uses PCH file with
2742 "-frepo" it would be incorrect to make decisions about what
2743 entities to emit when building the PCH; those decisions must be
2744 delayed until the repository information has been processed. */
2746 /* Object file linkage for explicit instantiations is handled in
2747 mark_decl_instantiated. For static variables in functions with
2748 vague linkage, maybe_commonize_var is used.
2750 Therefore, the only declarations that should be provided to this
2751 function are those with external linkage that are:
2753 * implicit instantiations of function templates
2755 * inline function
2757 * implicit instantiations of static data members of class
2758 templates
2760 * virtual tables
2762 * typeinfo objects
2764 Furthermore, all entities that reach this point must have a
2765 definition available in this translation unit.
2767 The following assertions check these conditions. */
2769 /* Any code that creates entities with TREE_PUBLIC cleared should
2770 also set DECL_INTERFACE_KNOWN. */
2776 else
2780 /* Check that a definition of DECL is available in this translation
2781 unit. */
2784 /* Assume that DECL will not have COMDAT linkage. */
2786 /* Assume that DECL will not be imported into this translation
2787 unit. */
2790 /* See if the repository tells us whether or not to emit DECL in
2791 this translation unit. */
2796 {
2797 /* The repository indicates that this entity should be defined
2798 here. Make sure the back end honors that request. */
2800 /* Output the definition as an ordinary strong definition. */
2804 }
2807 /* We have already decided what to do with this DECL; there is no
2808 need to check anything further. */
2809 ;
2811 {
2821 /* The ABI requires that all virtual tables be emitted with
2822 COMDAT linkage. However, on systems where COMDAT symbols
2823 don't show up in the table of contents for a static
2824 archive, or on systems without weak symbols (where we
2825 approximate COMDAT linkage by using internal linkage), the
2826 linker will report errors about undefined symbols because
2827 it will not see the virtual table definition. Therefore,
2828 in the case that we know that the virtual table will be
2829 emitted in only one translation unit, we make the virtual
2830 table an ordinary definition with external linkage. */
2833 {
2834 /* CLASS_TYPE is being exported from this translation unit,
2835 so DECL should be defined here. */
2837 /* If a class is declared in a header with the "extern
2838 template" extension, then it will not be instantiated,
2839 even in translation units that would normally require
2840 it. Often such classes are explicitly instantiated in
2841 one translation unit. Therefore, the explicit
2842 instantiation must be made visible to other translation
2843 units. */
2845 else
2846 {
2847 /* The generic C++ ABI says that class data is always
2848 COMDAT, even if there is a key function. Some
2849 variants (e.g., the ARM EABI) says that class data
2850 only has COMDAT linkage if the class data might be
2851 emitted in more than one translation unit. When the
2852 key method can be inline and is inline, we still have
2853 to arrange for comdat even though
2854 class_data_always_comdat is false. */
2858 {
2859 /* The ABI requires COMDAT linkage. Normally, we
2860 only emit COMDAT things when they are needed;
2861 make sure that we realize that this entity is
2862 indeed needed. */
2865 }
2866 }
2867 }
2871 else
2873 }
2875 {
2878 {
2884 /* If -fno-rtti was specified, then we cannot be sure
2885 that RTTI information will be emitted with the
2886 virtual table of the class, so we must emit it
2887 wherever it is used. */
2890 else
2891 {
2894 {
2900 {
2903 }
2904 }
2905 else
2907 }
2908 }
2909 else
2911 }
2913 {
2914 /* DECL is an implicit instantiation of a function or static
2915 data member. */
2918 || (flag_implicit_inline_templates
2922 else
2923 /* If we are not implicitly generating templates, then mark
2924 this entity as undefined in this translation unit. */
2926 }
2928 {
2930 {
2934 {
2938 && ! flag_implement_inlines
2944 /* Always make artificials weak. */
2947 else
2949 }
2950 }
2951 else
2953 }
2954 else
2958 {
2959 /* If we are importing DECL into this translation unit, mark is
2960 an undefined here. */
2963 }
2965 {
2966 /* If we decided to put DECL in COMDAT, mark it accordingly at
2967 this point. */
2969 }
2972 }
2974 /* Return an expression that performs the destruction of DECL, which
2975 must be a VAR_DECL whose type has a non-trivial destructor, or is
2976 an array whose (innermost) elements have a non-trivial destructor. */
2978 tree
2980 {
2984 }
2986 /* Returns the initialization guard variable for the variable DECL,
2987 which has static storage duration. */
2989 tree
2991 {
2992 tree sname;
2993 tree guard;
2998 {
2999 tree guard_type;
3001 /* We use a type that is big enough to contain a mutex as well
3002 as an integer counter. */
3007 /* The guard should have the same linkage as what it guards. */
3025 }
3027 }
3029 /* Return an atomic load of src with the appropriate memory model. */
3031 static tree
3033 {
3048 }
3050 /* Return those bits of the GUARD variable that should be set when the
3051 guarded entity is actually initialized. */
3053 static tree
3055 {
3057 {
3058 /* We only set the first byte of the guard, in order to leave room
3059 for a mutex in the high-order bits. */
3062 guard);
3065 guard);
3067 }
3070 }
3072 /* Return an expression which determines whether or not the GUARD
3073 variable has already been initialized. */
3075 tree
3077 {
3078 tree guard_value;
3082 else
3085 /* Mask off all but the low bit. */
3087 {
3093 tf_warning_or_error);
3094 }
3101 tf_warning_or_error);
3102 }
3104 /* Return an expression which sets the GUARD variable, indicating that
3105 the variable being guarded has been initialized. */
3107 tree
3109 {
3110 tree guard_init;
3112 /* Set the GUARD to one. */
3118 tf_warning_or_error);
3119 }
3121 /* Returns true iff we can tell that VAR does not have a dynamic
3122 initializer. */
3124 static bool
3126 {
3127 /* If it's defined in another TU, we can't tell. */
3130 /* If it has a non-trivial destructor, registering the destructor
3131 counts as dynamic initialization. */
3134 /* If it's in this TU, its initializer has been processed, unless
3135 it's a case of self-initialization, then DECL_INITIALIZED_P is
3136 false while the initializer is handled by finish_id_expression. */
3139 /* If it has no initializer or a constant one, it's not dynamic. */
3142 }
3144 /* Returns true iff VAR is a variable that needs uses to be
3145 wrapped for possible dynamic initialization. */
3147 static bool
3149 {
3155 }
3157 /* Get the FUNCTION_DECL for the shared TLS init function for this
3158 translation unit. */
3160 static tree
3162 {
3166 {
3169 void_list_node));
3175 }
3177 }
3179 /* Get a FUNCTION_DECL for the init function for the thread_local
3180 variable VAR. The init function will be an alias to the function
3181 that initializes all the non-local TLS variables in the translation
3182 unit. The init function is only used by the wrapper function. */
3184 static tree
3186 {
3187 /* Only C++11 TLS vars need this init fn. */
3191 /* If -fno-extern-tls-init, assume that we don't need to call
3192 a tls init function for a variable defined in another TU. */
3196 #ifdef ASM_OUTPUT_DEF
3197 /* If the variable is internal, or if we can't generate aliases,
3198 call the local init function directly. */
3200 #endif
3206 {
3209 void_list_node));
3218 {
3220 /* If the variable is defined somewhere else and might have static
3221 initialization, make the init function a weak reference. */
3227 else
3229 }
3239 }
3241 }
3243 /* Get a FUNCTION_DECL for the init wrapper function for the thread_local
3244 variable VAR. The wrapper function calls the init function (if any) for
3245 VAR and then returns a reference to VAR. The wrapper function is used
3246 in place of VAR everywhere VAR is mentioned. */
3248 tree
3250 {
3251 /* Only C++11 TLS vars need this wrapper fn. */
3258 {
3259 /* A named rvalue reference is an lvalue, so the wrapper should
3260 always return an lvalue reference. */
3269 /* The wrapper is inline and emitted everywhere var is used. */
3272 {
3274 #ifdef HAVE_GAS_HIDDEN
3275 /* Make the wrapper bind locally; there's no reason to share
3276 the wrapper between multiple shared objects. */
3279 #endif
3280 }
3286 #if 0
3287 /* We want CSE to commonize calls to the wrapper, but marking it as
3288 pure is unsafe since it has side-effects. I guess we need a new
3289 ECF flag even weaker than ECF_PURE. FIXME! */
3291 #endif
3296 }
3298 }
3300 /* At EOF, generate the definition for the TLS wrapper function FN:
3302 T& var_wrapper() {
3303 if (init_fn) init_fn();
3304 return var;
3305 } */
3307 static void
3309 {
3314 /* Only call the init fn if there might be one. */
3316 {
3318 /* If init_fn is a weakref, make sure it exists before calling. */
3320 {
3325 tf_warning_or_error);
3327 }
3331 {
3334 }
3335 }
3336 else
3337 /* If there's no initialization, the wrapper is a constant function. */
3342 }
3344 /* Start the process of running a particular set of global constructors
3345 or destructors. Subroutine of do_[cd]tors. Also called from
3346 vtv_start_verification_constructor_init_function. */
3348 static tree
3350 {
3351 tree body;
3352 tree fndecl;
3355 /* Make ctor or dtor function. METHOD_TYPE may be 'I' or 'D'. */
3358 {
3361 #ifdef JOINER
3363 #else
3365 #endif
3368 }
3369 else
3375 NULL_TREE));
3380 /* Mark as artificial because it's not explicitly in the user's
3381 source code. */
3384 /* Mark this declaration as used to avoid spurious warnings. */
3387 /* Mark this function as a global constructor or destructor. */
3390 else
3396 }
3398 /* Finish the process of running a particular set of global constructors
3399 or destructors. Subroutine of do_[cd]tors. */
3401 static void
3403 {
3404 tree fn;
3406 /* Finish up. */
3411 {
3414 }
3415 else
3416 {
3419 }
3422 }
3424 /* The names of the parameters to the function created to handle
3425 initializations and destructions for objects with static storage
3426 duration. */
3430 /* The name of the function we create to handle initializations and
3431 destructions for objects with static storage duration. */
3434 /* The declaration for the __INITIALIZE_P argument. */
3437 /* The declaration for the __PRIORITY argument. */
3440 /* The declaration for the static storage duration function. */
3443 /* All the static storage duration functions created in this
3444 translation unit. */
3447 /* A map from priority levels to information about that priority
3448 level. There may be many such levels, so efficient lookup is
3449 important. */
3452 /* Begins the generation of the function that will handle all
3453 initialization and destruction of objects with static storage
3454 duration. The function generated takes two parameters of type
3455 `int': __INITIALIZE_P and __PRIORITY. If __INITIALIZE_P is
3456 nonzero, it performs initializations. Otherwise, it performs
3457 destructions. It only performs those initializations or
3458 destructions with the indicated __PRIORITY. The generated function
3459 returns no value.
3461 It is assumed that this function will only be called once per
3462 translation unit. */
3464 static tree
3466 {
3467 tree type;
3468 tree body;
3471 /* Create the identifier for this function. It will be of the form
3472 SSDF_IDENTIFIER_<number>. */
3477 NULL_TREE);
3479 /* Create the FUNCTION_DECL itself. */
3482 type);
3486 /* Put this function in the list of functions to be called from the
3487 static constructors and destructors. */
3489 {
3492 /* Take this opportunity to initialize the map from priority
3493 numbers to information about that priority level. */
3496 /*delete_value_fn=*/
3499 /* We always need to generate functions for the
3500 DEFAULT_INIT_PRIORITY so enter it now. That way when we walk
3501 priorities later, we'll be sure to find the
3502 DEFAULT_INIT_PRIORITY. */
3504 }
3508 /* Create the argument list. */
3509 initialize_p_decl = cp_build_parm_decl
3513 priority_decl = cp_build_parm_decl
3521 /* Put the function in the global scope. */
3524 /* Start the function itself. This is equivalent to declaring the
3525 function as:
3527 static void __ssdf (int __initialize_p, init __priority_p);
3529 It is static because we only need to call this function from the
3530 various constructor and destructor functions for this module. */
3533 SF_PRE_PARSED);
3535 /* Set up the scope of the outermost block in the function. */
3539 }
3541 /* Finish the generation of the function which performs initialization
3542 and destruction of objects with static storage duration. After
3543 this point, no more such objects can be created. */
3545 static void
3547 {
3548 /* Close out the function. */
3551 }
3553 /* Return the information about the indicated PRIORITY level. If no
3554 code to handle this level has yet been generated, generate the
3555 appropriate prologue. */
3557 static priority_info
3559 {
3560 priority_info pi;
3561 splay_tree_node n;
3566 {
3567 /* Create a new priority information structure, and insert it
3568 into the map. */
3575 }
3576 else
3580 }
3582 /* The effective initialization priority of a DECL. */
3584 #define DECL_EFFECTIVE_INIT_PRIORITY(decl) \
3585 ((!DECL_HAS_INIT_PRIORITY_P (decl) || DECL_INIT_PRIORITY (decl) == 0) \
3586 ? DEFAULT_INIT_PRIORITY : DECL_INIT_PRIORITY (decl))
3588 /* Whether a DECL needs a guard to protect it against multiple
3589 initialization. */
3591 #define NEEDS_GUARD_P(decl) (TREE_PUBLIC (decl) && (DECL_COMMON (decl) \
3592 || DECL_ONE_ONLY (decl) \
3593 || DECL_WEAK (decl)))
3595 /* Called from one_static_initialization_or_destruction(),
3596 via walk_tree.
3597 Walks the initializer list of a global variable and looks for
3598 temporary variables (DECL_NAME() == NULL and DECL_ARTIFICIAL != 0)
3599 and that have their DECL_CONTEXT() == NULL.
3600 For each such temporary variable, set their DECL_CONTEXT() to
3601 the current function. This is necessary because otherwise
3602 some optimizers (enabled by -O2 -fprofile-arcs) might crash
3603 when trying to refer to a temporary variable that does not have
3604 it's DECL_CONTECT() properly set. */
3605 static tree
3609 {
3613 {
3614 tree var;
3622 }
3625 }
3627 /* Set up to handle the initialization or destruction of DECL. If
3628 INITP is nonzero, we are initializing the variable. Otherwise, we
3629 are destroying it. */
3631 static void
3633 {
3635 tree guard;
3637 /* If we are supposed to destruct and there's a trivial destructor,
3638 nothing has to be done. */
3643 /* Trick the compiler into thinking we are at the file and line
3644 where DECL was declared so that error-messages make sense, and so
3645 that the debugger will show somewhat sensible file and line
3646 information. */
3649 /* Make sure temporary variables in the initialiser all have
3650 their DECL_CONTEXT() set to a value different from NULL_TREE.
3651 This can happen when global variables initializers are built.
3652 In that case, the DECL_CONTEXT() of the global variables _AND_ of all
3653 the temporary variables that might have been generated in the
3654 accompanying initializers is NULL_TREE, meaning the variables have been
3655 declared in the global namespace.
3656 What we want to do here is to fix that and make sure the DECL_CONTEXT()
3657 of the temporaries are set to the current function decl. */
3659 fix_temporary_vars_context_r,
3660 NULL);
3662 /* Because of:
3664 [class.access.spec]
3666 Access control for implicit calls to the constructors,
3667 the conversion functions, or the destructor called to
3668 create and destroy a static data member is performed as
3669 if these calls appeared in the scope of the member's
3670 class.
3672 we pretend we are in a static member function of the class of
3673 which the DECL is a member. */
3675 {
3678 }
3680 /* Assume we don't need a guard. */
3682 /* We need a guard if this is an object with external linkage that
3683 might be initialized in more than one place. (For example, a
3684 static data member of a template, when the data member requires
3685 construction.) */
3687 {
3688 tree guard_cond;
3692 /* When using __cxa_atexit, we just check the GUARD as we would
3693 for a local static. */
3695 {
3696 /* When using __cxa_atexit, we never try to destroy
3697 anything from a static destructor. */
3700 }
3701 /* If we don't have __cxa_atexit, then we will be running
3702 destructors from .fini sections, or their equivalents. So,
3703 we need to know how many times we've tried to initialize this
3704 object. We do initializations only if the GUARD is zero,
3705 i.e., if we are the first to initialize the variable. We do
3706 destructions only if the GUARD is one, i.e., if we are the
3707 last to destroy the variable. */
3709 guard_cond
3711 EQ_EXPR,
3713 guard,
3715 tf_warning_or_error),
3716 integer_one_node,
3717 tf_warning_or_error);
3718 else
3719 guard_cond
3721 EQ_EXPR,
3723 guard,
3725 tf_warning_or_error),
3726 integer_zero_node,
3727 tf_warning_or_error);
3731 }
3734 /* If we're using __cxa_atexit, we have not already set the GUARD,
3735 so we must do so now. */
3739 /* Perform the initialization or destruction. */
3741 {
3743 {
3746 {
3750 }
3751 }
3753 /* If we're using __cxa_atexit, register a function that calls the
3754 destructor for the object. */
3757 }
3758 else
3761 /* Finish the guard if-stmt, if necessary. */
3763 {
3766 }
3768 /* Now that we're done with DECL we don't need to pretend to be a
3769 member of its class any longer. */
3772 }
3774 /* Generate code to do the initialization or destruction of the decls in VARS,
3775 a TREE_LIST of VAR_DECL with static storage duration.
3776 Whether initialization or destruction is performed is specified by INITP. */
3778 static void
3780 {
3783 /* Build the outer if-stmt to check for initialization or destruction. */
3787 EQ_EXPR,
3788 initialize_p_decl,
3789 cond,
3790 tf_warning_or_error);
3793 /* To make sure dynamic construction doesn't access globals from other
3794 compilation units where they might not be yet constructed, for
3795 -fsanitize=address insert __asan_before_dynamic_init call that
3796 prevents access to either all global variables that need construction
3797 in other compilation units, or at least those that haven't been
3798 initialized yet. Variables that need dynamic construction in
3799 the current compilation unit are kept accessible. */
3806 tree priority_if_stmt;
3808 priority_info pi;
3810 /* If we don't need a destructor, there's nothing to do. Avoid
3811 creating a possibly empty if-stmt. */
3813 {
3816 }
3818 /* Remember that we had an initialization or finalization at this
3819 priority. */
3824 else
3827 /* Conditionalize this initialization on being in the right priority
3828 and being initializing/finalizing appropriately. */
3831 EQ_EXPR,
3832 priority_decl,
3834 tf_warning_or_error);
3837 /* Process initializers with same priority. */
3841 /* Do one initialization or destruction. */
3845 /* Finish up the priority if-stmt body. */
3851 /* Revert what __asan_before_dynamic_init did by calling
3852 __asan_after_dynamic_init. */
3856 /* Finish up the init/destruct if-stmt body. */
3859 }
3861 /* VARS is a list of variables with static storage duration which may
3862 need initialization and/or finalization. Remove those variables
3863 that don't really need to be initialized or finalized, and return
3864 the resulting list. The order in which the variables appear in
3865 VARS is in reverse order of the order in which they should actually
3866 be initialized. The list we return is in the unreversed order;
3867 i.e., the first variable should be initialized first. */
3869 static tree
3871 {
3876 {
3881 /* Deal gracefully with error. */
3883 {
3886 }
3888 /* The only things that can be initialized are variables. */
3891 /* If this object is not defined, we don't need to do anything
3892 here. */
3894 {
3897 }
3899 /* Also, if the initializer already contains errors, we can bail
3900 out now. */
3903 {
3906 }
3908 /* This variable is going to need initialization and/or
3909 finalization, so we add it to the list. */
3913 }
3916 }
3918 /* Make sure we have told the back end about all the variables in
3919 VARS. */
3921 static void
3923 {
3924 tree v;
3927 {
3930 {
3933 }
3934 }
3935 }
3937 /* Generate a static constructor (if CONSTRUCTOR_P) or destructor
3938 (otherwise) that will initialize all global objects with static
3939 storage duration having the indicated PRIORITY. */
3941 static void
3944 {
3946 tree fndecl;
3947 tree body;
3951 /* ??? */
3952 /* Was: locus->line++; */
3954 /* We use `I' to indicate initialization and `D' to indicate
3955 destruction. */
3958 /* We emit the function lazily, to avoid generating empty
3959 global constructors and destructors. */
3962 /* For Objective-C++, we may need to initialize metadata found in this module.
3963 This must be done _before_ any other static initializations. */
3966 {
3969 }
3971 /* Call the static storage duration function with appropriate
3972 arguments. */
3974 {
3975 /* Calls to pure or const functions will expand to nothing. */
3977 {
3978 tree call;
3985 constructor_p),
3987 priority),
3988 NULL_TREE);
3990 }
3991 }
3993 /* Close out the function. */
3996 }
3998 /* Generate constructor and destructor functions for the priority
3999 indicated by N. */
4001 static int
4003 {
4008 /* Generate the functions themselves, but only if they are really
4009 needed. */
4015 /* Keep iterating. */
4017 }
4019 /* Return C++ property of T, based on given operation OP. */
4021 static int
4023 {
4025 {
4027 {
4035 }
4052 }
4053 }
4055 /* Collect source file references recursively, starting from NAMESPC. */
4057 static void
4059 {
4060 tree t;
4065 /* Iterate over names in this name space. */
4070 /* Dump siblings, if any */
4073 /* Dump children, if any */
4075 }
4077 /* Collect decls relevant to SOURCE_FILE from all namespaces recursively,
4078 starting from NAMESPC. */
4080 static void
4082 {
4086 /* Collect decls from this namespace */
4089 /* Collect siblings, if any */
4092 /* Collect children, if any */
4094 }
4096 /* Returns true iff there is a definition available for variable or
4097 function DECL. */
4099 bool
4101 {
4104 /* A pending instantiation of a friend temploid is defined. */
4108 else
4109 {
4112 }
4113 }
4115 /* Nonzero for a VAR_DECL whose value can be used in a constant expression.
4117 [expr.const]
4119 An integral constant-expression can only involve ... const
4120 variables of integral or enumeration types initialized with
4121 constant expressions ...
4123 C++0x also allows constexpr variables and temporaries initialized
4124 with constant expressions. We handle the former here, but the latter
4125 are just folded away in cxx_eval_constant_expression.
4127 The standard does not require that the expression be non-volatile.
4128 G++ implements the proposed correction in DR 457. */
4130 bool
4132 {
4136 /* We don't know if a template static data member is initialized with
4137 a constant expression until we instantiate its initializer. Even
4138 in the case of a constexpr variable, we can't treat it as a
4139 constant until its initializer is complete in case it's used in
4140 its own initializer. */
4143 }
4145 /* Returns true if DECL could be a symbolic constant variable, depending on
4146 its initializer. */
4148 bool
4150 {
4157 /* A proxy isn't constant. */
4160 /* References can be constant. */
4164 }
4166 /* Complain that DECL uses a type with no linkage. In C++98 mode this is
4167 called from grokfndecl and grokvardecl; in all modes it is called from
4168 cp_write_global_declarations. */
4170 void
4172 {
4174 /* In C++11 it's ok if the decl is defined. */
4178 /* The type that got us on no_linkage_decls must have gotten a name for
4181 /* The type might end up having a typedef name for linkage purposes. */
4184 {
4192 /* DRs 132, 319 and 389 seem to indicate types with
4193 no linkage can only be used to declare extern "C"
4194 entities. Since it's not always an error in the
4195 ISO C++ 90 Standard, we only issue a warning. */
4197 "with no linkage used to declare variable %q#D with "
4199 else
4202 decl);
4207 }
4209 {
4212 "%q#D, declared using local type "
4214 }
4218 else
4221 }
4223 /* Collect declarations from all namespaces relevant to SOURCE_FILE. */
4225 static void
4227 {
4229 }
4231 /* Clear DECL_EXTERNAL for NODE. */
4233 static bool
4235 {
4238 }
4240 /* Build up the function to run dynamic initializers for thread_local
4241 variables in this translation unit and alias the init functions for the
4242 individual variables to it. */
4244 static void
4246 {
4256 boolean_type_node);
4271 tf_warning_or_error);
4274 boolean_true_node,
4275 tf_warning_or_error));
4277 {
4282 #ifdef ASM_OUTPUT_DEF
4283 /* Output init aliases even with -fno-extern-tls-init. */
4285 {
4289 cgraph_node *alias
4293 }
4294 #endif
4295 }
4301 }
4303 /* We're at the end of compilation, so generate any mangling aliases that
4304 we've been saving up, if DECL is going to be output and ID2 isn't
4305 already taken by another declaration. */
4307 static void
4309 {
4310 /* If there's a declaration already using this mangled name,
4311 don't create a compatibility alias that conflicts. */
4318 /* Don't create an alias to an unreferenced function. */
4330 else
4332 }
4334 /* Note that we might want to emit an alias with the symbol ID2 for DECL at
4335 the end of translation, for compatibility across bugs in the mangling
4336 implementation. */
4338 void
4340 {
4341 #ifdef ASM_OUTPUT_DEF
4344 else
4345 {
4348 }
4349 #endif
4350 }
4352 /* Emit all mangling aliases that were deferred up to this point. */
4354 void
4356 {
4358 {
4362 }
4364 }
4366 /* The entire file is now complete. If requested, dump everything
4367 to a file. */
4369 static void
4371 {
4376 {
4379 }
4380 }
4384 /* Check the deallocation functions for CODE to see if we want to warn that
4385 only one was defined. */
4387 static void
4389 {
4395 {
4397 /* We're only interested in usual deallocation functions. */
4402 else
4404 }
4411 }
4413 /* Check the global deallocation functions to see if we want to warn about
4414 defining unsized without sized (or vice versa). */
4416 static void
4418 {
4423 }
4425 /* Earlier we left PTRMEM_CST in variable initializers alone so that we could
4426 look them up when evaluating non-type template parameters. Now we need to
4427 lower them to something the back end can understand. */
4429 static void
4431 {
4434 {
4438 }
4439 }
4441 /* This routine is called at the end of compilation.
4442 Its job is to create all the code needed to initialize and
4443 destroy the global aggregates. We do the destruction
4444 first, since that way we only need to reverse the decls once. */
4446 void
4448 {
4449 tree vars;
4454 tree decl;
4459 /* Bad parse errors. Just forget about it. */
4464 /* This is the point to write out a PCH if we're doing that.
4465 In that case we do not want to do anything else. */
4467 {
4468 /* Mangle all symbols at PCH creation time. */
4476 /* Ensure even the callers don't try to finalize the CU. */
4479 }
4486 /* Handle -fdump-ada-spec[-slim] */
4488 {
4491 else
4495 }
4497 /* FIXME - huh? was input_line -= 1;*/
4499 /* We now have to write out all the stuff we put off writing out.
4500 These include:
4502 o Template specializations that we have not yet instantiated,
4503 but which are needed.
4504 o Initialization and destruction for non-local objects with
4505 static storage duration. (Local objects with static storage
4506 duration are initialized when their scope is first entered,
4507 and are cleaned up via atexit.)
4508 o Virtual function tables.
4510 All of these may cause others to be needed. For example,
4511 instantiating one function may cause another to be needed, and
4512 generating the initializer for an object may cause templates to be
4513 instantiated, etc., etc. */
4517 do
4518 {
4519 tree t;
4520 tree decl;
4524 /* If there are templates that we've put off instantiating, do
4525 them now. */
4529 /* Write out virtual tables as required. Note that writing out
4530 the virtual table for a template class may cause the
4531 instantiation of members of that class. If we write out
4532 vtables then we remove the class from our list so we don't
4533 have to look at it again. */
4537 {
4540 }
4544 {
4548 {
4550 {
4553 }
4554 else
4558 }
4559 }
4561 /* Write out needed type info variables. We have to be careful
4562 looping through unemitted decls, because emit_tinfo_decl may
4563 cause other variables to be needed. New elements will be
4564 appended, and we remove from the vector those that actually
4565 get emitted. */
4569 {
4572 }
4574 /* The list of objects with static storage duration is built up
4575 in reverse order. We clear STATIC_AGGREGATES so that any new
4576 aggregates added during the initialization of these will be
4577 initialized in the correct order when we next come around the
4578 loop. */
4582 {
4583 /* We need to start a new initialization function each time
4584 through the loop. That's because we need to know which
4585 vtables have been referenced, and TREE_SYMBOL_REFERENCED
4586 isn't computed until a function is finished, and written
4587 out. That's a deficiency in the back end. When this is
4588 fixed, these initialization functions could all become
4589 inline, with resulting performance improvements. */
4590 tree ssdf_body;
4592 /* Set the line and file, so that it is obviously not from
4593 the source file. */
4597 /* Make sure the back end knows about all the variables. */
4600 /* First generate code to do all the initializations. */
4604 /* Then, generate code to do all the destructions. Do these
4605 in reverse order so that the most recently constructed
4606 variable is the first destroyed. If we're using
4607 __cxa_atexit, then we don't need to do this; functions
4608 were registered at initialization time to destroy the
4609 local statics. */
4611 {
4614 }
4615 else
4618 /* Finish up the static storage duration function for this
4619 round. */
4623 /* All those initializations and finalizations might cause
4624 us to need more inline functions, more template
4625 instantiations, etc. */
4627 ssdf_count++;
4628 /* ??? was: locus_at_end_of_parsing.line++; */
4629 }
4631 /* Now do the same for thread_local variables. */
4634 /* Go through the set of inline functions whose bodies have not
4635 been emitted yet. If out-of-line copies of these functions
4636 are required, emit them. */
4638 {
4639 /* Does it need synthesizing? */
4642 {
4643 /* Even though we're already at the top-level, we push
4644 there again. That way, when we pop back a few lines
4645 hence, all of our state is restored. Otherwise,
4646 finish_function doesn't clean things up, and we end
4647 up with CURRENT_FUNCTION_DECL set. */
4649 /* The decl's location will mark where it was first
4650 needed. Save that so synthesize method can indicate
4651 where it was needed from, in case of error */
4656 }
4664 /* We lie to the back end, pretending that some functions
4665 are not defined when they really are. This keeps these
4666 functions from being put out unnecessarily. But, we must
4667 stop lying when the functions are referenced, or if they
4668 are not comdat since they need to be put out now. If
4669 DECL_INTERFACE_KNOWN, then we have already set
4670 DECL_EXTERNAL appropriately, so there's no need to check
4671 again, and we do not want to clear DECL_EXTERNAL if a
4672 previous call to import_export_decl set it.
4674 This is done in a separate for cycle, because if some
4675 deferred function is contained in another deferred
4676 function later in deferred_fns varray,
4677 rest_of_compilation would skip this function and we
4678 really cannot expand the same function twice. */
4683 {
4692 /* If we mark !DECL_EXTERNAL one of the symbols in some comdat
4693 group, we need to mark all symbols in the same comdat group
4694 that way. */
4701 }
4703 /* If we're going to need to write this function out, and
4704 there's already a body for it, create RTL for it now.
4705 (There might be no body if this is a method we haven't
4706 gotten around to synthesizing yet.) */
4711 {
4712 /* We will output the function; no longer consider it in this
4713 loop. */
4715 /* Generate RTL for this function now that we know we
4716 need it. */
4718 /* If we're compiling -fsyntax-only pretend that this
4719 function has been written out so that we don't try to
4720 expand it again. */
4724 }
4725 }
4730 /* Static data members are just like namespace-scope globals. */
4732 {
4734 /* Don't write it out if we haven't seen a definition. */
4738 /* If this static data member is needed, provide it to the
4739 back end. */
4742 }
4748 retries++;
4749 }
4758 /* All used inline functions must have a definition at this point. */
4760 {
4763 /* If the definition actually was available here, then the
4764 fact that the function was not defined merely represents
4765 that for some reason (use of a template repository,
4766 #pragma interface, etc.) we decided not to emit the
4767 definition here. */
4769 /* Don't complain if the template was defined. */
4773 {
4776 /* Avoid a duplicate warning from check_global_declaration. */
4778 }
4779 }
4781 /* So must decls that use a type with no linkage. */
4787 /* Then, do the Objective-C stuff. This is where all the
4788 Objective-C module stuff gets generated (symtab,
4789 class/protocol/selector lists etc). This must be done after C++
4790 templates, destructors etc. so that selectors used in C++
4791 templates are properly allocated. */
4795 /* We give C linkage to static constructors and destructors. */
4798 /* Generate initialization and destruction functions for all
4799 priorities for which they are required. */
4802 generate_ctor_and_dtor_functions_for_priority,
4805 /* If this is obj-c++ and we need a static init, call
4806 generate_ctor_or_dtor_function. */
4808 DEFAULT_INIT_PRIORITY,
4811 /* We're done with the splay-tree now. */
4815 /* Generate any missing aliases. */
4818 /* We're done with static constructors, so we can go back to "C++"
4819 linkage now. */
4823 {
4827 }
4835 /* The entire file is now complete. If requested, dump everything
4836 to a file. */
4840 {
4843 }
4848 /* Indicate that we're done with front end processing. */
4850 }
4852 /* Perform any post compilation-proper cleanups for the C++ front-end.
4853 This should really go away. No front-end should need to do
4854 anything past the compilation process. */
4856 void
4858 {
4862 {
4863 /* Generate the special constructor initialization function that
4864 calls __VLTRegisterPairs, and give it a very high
4865 initialization priority. This must be done after
4866 finalize_compilation_unit so that we have accurate
4867 information about which vtable will actually be emitted. */
4869 }
4877 }
4879 /* FN is an OFFSET_REF, DOTSTAR_EXPR or MEMBER_REF indicating the
4880 function to call in parse-tree form; it has not yet been
4881 semantically analyzed. ARGS are the arguments to the function.
4882 They have already been semantically analyzed. This may change
4883 ARGS. */
4885 tree
4887 tsubst_flags_t complain)
4888 {
4889 tree orig_fn;
4891 tree expr;
4892 tree object;
4898 {
4907 /* Transform the arguments and add the implicit "this"
4908 parameter. That must be done before the FN is transformed
4909 because we depend on the form of FN. */
4913 {
4917 }
4918 /* Now that the arguments are done, transform FN. */
4920 }
4922 /* A qualified name corresponding to a bound pointer-to-member is
4923 represented as an OFFSET_REF:
4925 struct B { void g(); };
4926 void (B::*p)();
4927 void B::g() { (this->*p)(); } */
4929 {
4933 complain);
4935 }
4939 else
4948 }
4951 void
4953 {
4958 {
4962 {
4965 }
4966 }
4967 }
4969 /* Return true if function DECL can be inlined. This is used to force
4970 instantiation of methods that might be interesting for inlining. */
4971 bool
4973 {
4979 /* When optimizing, we might inline everything when flatten
4980 attribute or heuristics inlining for size or autoinlining
4981 is used. */
4983 }
4985 /* Normally, we can wait until instantiation-time to synthesize DECL.
4986 However, if DECL is a static data member initialized with a constant
4987 or a constexpr function, we need it right now because a reference to
4988 such a data member or a call to such function is not value-dependent.
4989 For a function that uses auto in the return type, we need to instantiate
4990 it to find out its type. For OpenMP user defined reductions, we need
4991 them instantiated for reduction clauses which inline them by hand
4992 directly. */
4994 static void
4996 {
5005 {
5006 /* Instantiating a function will result in garbage collection. We
5007 must treat this situation as if we were within the body of a
5008 function so as to avoid collecting live data only referenced from
5009 the stack (such as overload resolution candidates). */
5014 }
5015 }
5017 /* Mark DECL (either a _DECL or a BASELINK) as "used" in the program.
5018 If DECL is a specialization or implicitly declared class member,
5019 generate the actual definition. Return false if something goes
5020 wrong, true otherwise. */
5022 bool
5024 {
5025 /* If DECL is a BASELINK for a single function, then treat it just
5026 like the DECL for the function. Otherwise, if the BASELINK is
5027 for an overloaded function, we don't know which function was
5028 actually used until after overload resolution. */
5030 {
5035 }
5037 /* Set TREE_USED for the benefit of -Wunused. */
5046 /* Mark enumeration types as used. */
5055 {
5057 {
5060 {
5061 /* We mark a lambda conversion op as deleted if we can't
5062 generate it properly; see maybe_add_lambda_conv_op. */
5066 }
5067 }
5069 {
5073 }
5075 }
5081 /* We can only check DECL_ODR_USED on variables or functions with
5082 DECL_LANG_SPECIFIC set, and these are also the only decls that we
5083 might need special handling for. */
5087 {
5092 }
5094 /* We only want to do this processing once. We don't need to keep trying
5095 to instantiate inline templates, because unit-at-a-time will make sure
5096 we get them compiled before functions that want to inline them. */
5100 /* Normally, we can wait until instantiation-time to synthesize DECL.
5101 However, if DECL is a static data member initialized with a constant
5102 or a constexpr function, we need it right now because a reference to
5103 such a data member or a call to such function is not value-dependent.
5104 For a function that uses auto in the return type, we need to instantiate
5105 it to find out its type. For OpenMP user defined reductions, we need
5106 them instantiated for reduction clauses which inline them by hand
5107 directly. */
5113 /* Check this too in case we're within instantiate_non_dependent_expr. */
5121 /* If we don't need a value, then we don't need to synthesize DECL. */
5129 /* DR 757: A type without linkage shall not be used as the type of a
5130 variable or function with linkage, unless
5131 o the variable or function has extern "C" linkage (7.5 [dcl.link]), or
5132 o the variable or function is not used (3.2 [basic.def.odr]) or is
5133 defined in the same translation unit. */
5140 {
5142 /* There's no way to define a local extern, and adding it to
5143 the vector interferes with GC, so give an error now. */
5145 else
5147 }
5151 /* Remember it, so we can check it was defined. */
5154 /* Is it a synthesized method that needs to be synthesized? */
5158 /* A function defaulted outside the class is synthesized either by
5159 cp_finish_decl or instantiate_decl. */
5162 {
5163 /* Defer virtual destructors so that thunks get the right
5164 linkage. */
5166 {
5169 }
5171 /* Remember the current location for a function we will end up
5172 synthesizing. Then we can inform the user where it was
5173 required in the case of error. */
5176 /* Synthesizing an implicitly defined member function will result in
5177 garbage collection. We must treat this situation as if we were
5178 within the body of a function so as to avoid collecting live data
5179 on the stack (such as overload resolution candidates).
5181 We could just let cp_write_global_declarations handle synthesizing
5182 this function by adding it to deferred_fns, but doing
5183 it at the use site produces better error messages. */
5187 /* If this is a synthesized method we don't need to
5188 do the instantiation test below. */
5189 }
5195 /* If this is a function or variable that is an instance of some
5196 template, we now know that we will need to actually do the
5197 instantiation. We check that DECL is not an explicit
5198 instantiation because that is not checked in instantiate_decl.
5200 We put off instantiating functions in order to improve compile
5201 times. Maintaining a stack of active functions is expensive,
5202 and the inliner knows to instantiate any functions it might
5203 need. Therefore, we always try to defer instantiation. */
5204 {
5209 }
5212 }
5214 bool
5216 {
5218 }
5220 tree
5222 {
5224 }
5226 tree
5228 {
5229 tree fn;
5237 }