| blob | 2da6f9023c5b764947ffc998a85622a4862b1cee |
1 /* Process declarations and variables for C++ compiler.
2 Copyright (C) 1988-2018 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 /* hash traits for declarations. Hashes single decls via
106 DECL_ASSEMBLER_NAME_RAW. */
109 {
114 {
116 }
118 {
121 }
127 {
129 }
131 {
133 }
134 };
136 /* A hash table of decls keyed by mangled name. Used to figure out if
137 we need compatibility aliases. */
140 /* Nonzero if we're done parsing and into end-of-file activities. */
144 /* True if note_mangling_alias should enqueue mangling aliases for
145 later generation, rather than emitting them right away. */
148 \f
150 /* Return a member function type (a METHOD_TYPE), given FNTYPE (a
151 FUNCTION_TYPE), CTYPE (class type), and QUALS (the cv-qualifiers
152 that apply to the function). */
154 tree
156 cp_ref_qualifier rqual)
157 {
158 tree raises;
159 tree attrs;
188 }
190 /* Return a variant of FNTYPE, a FUNCTION_TYPE or METHOD_TYPE, with its
191 return type changed to NEW_RET. */
193 tree
195 {
196 tree newtype;
209 {
214 }
215 else
216 newtype = build_method_type_directly
228 }
230 /* Build a PARM_DECL of FN with NAME and TYPE, and set DECL_ARG_TYPE
231 appropriately. */
233 tree
235 {
240 /* DECL_ARG_TYPE is only used by the back end and the back end never
241 sees templates. */
246 }
248 /* Returns a PARM_DECL of FN for a parameter of the indicated TYPE, with the
249 indicated NAME. */
251 tree
253 {
256 /* All our artificial parms are implicitly `const'; they cannot be
257 assigned to. */
260 }
262 /* Constructors for types with virtual baseclasses need an "in-charge" flag
263 saying whether this constructor is responsible for initialization of
264 virtual baseclasses or not. All destructors also need this "in-charge"
265 flag, which additionally determines whether or not the destructor should
266 free the memory for the object.
268 This function adds the "in-charge" flag to member function FN if
269 appropriate. It is called from grokclassfn and tsubst.
270 FN must be either a constructor or destructor.
272 The in-charge flag follows the 'this' parameter, and is followed by the
273 VTT parm (if any), then the user-written parms. */
275 void
277 {
280 /* If we've already add the in-charge parameter don't do it again. */
284 /* When processing templates we can't know, in general, whether or
285 not we're going to have virtual baseclasses. */
289 /* We don't need an in-charge parameter for constructors that don't
290 have virtual bases. */
301 /* If this is a subobject constructor or destructor, our caller will
302 pass us a pointer to our VTT. */
304 {
307 /* First add it to DECL_ARGUMENTS between 'this' and the real args... */
311 /* ...and then to TYPE_ARG_TYPES. */
315 }
317 /* Then add the in-charge parm (before the VTT parm). */
323 /* Insert our new parameter(s) into the list. */
326 /* And rebuild the function type. */
328 arg_types);
333 fntype = (cp_build_type_attribute_variant
337 /* Now we've got the in-charge parameter. */
339 }
341 /* Classes overload their constituent function names automatically.
342 When a function name is declared in a record structure,
343 its name is changed to it overloaded name. Since names for
344 constructors and destructors can conflict, we place a leading
345 '$' for destructors.
347 CNAME is the name of the class we are grokking for.
349 FUNCTION is a FUNCTION_DECL. It was created by `grokdeclarator'.
351 FLAGS contains bits saying what's special about today's
352 arguments. DTOR_FLAG == DESTRUCTOR.
354 If FUNCTION is a destructor, then we must add the `auto-delete' field
355 as a second parameter. There is some hair associated with the fact
356 that we must "declare" this variable in the manner consistent with the
357 way the rest of the arguments were declared.
359 QUALS are the qualifiers for the this pointer. */
361 void
363 {
366 /* Even within an `extern "C"' block, members get C++ linkage. See
367 [dcl.link] for details. */
371 {
375 }
384 }
386 /* Create an ARRAY_REF, checking for the user doing things backwards
387 along the way. DECLTYPE_P is for N3276, as in the parser. */
389 tree
392 {
393 tree type;
394 tree expr;
403 {
410 }
416 /* If they have an `operator[]', use that. */
418 {
424 }
425 else
426 {
429 /* Otherwise, create an ARRAY_REF for a pointer or array type.
430 It is a little-known fact that, if `a' is an array and `i' is
431 an int, you can write `i[a]', which means the same thing as
432 `a[i]'. */
435 else
440 else
455 else
456 {
460 }
467 else
471 }
473 {
480 }
482 }
484 /* Given the cast expression EXP, checking out its validity. Either return
485 an error_mark_node if there was an unavoidable error, return a cast to
486 void for trying to delete a pointer w/ the value 0, or return the
487 call to delete. If DOING_VEC is true, we handle things differently
488 for doing an array delete.
489 Implements ARM $5.3.4. This is called from the parser. */
491 tree
493 tsubst_flags_t complain)
494 {
501 {
507 }
509 /* An array can't have been allocated by new, so complain. */
516 {
520 }
524 /* As of Valley Forge, you can delete a pointer to const. */
526 /* You can't delete functions. */
528 {
532 }
534 /* Deleting ptr to void is undefined behavior [expr.delete/3]. */
536 {
539 }
541 /* Deleting a pointer with the value zero is valid and has no effect. */
547 sfk_deleting_destructor,
549 else
552 complain);
553 }
555 /* Report an error if the indicated template declaration is not the
556 sort of thing that should be a member template. */
558 void
560 {
561 tree decl;
570 {
571 /* The parser rejects template declarations in local classes
572 (with the exception of generic lambdas). */
574 /* The parser rejects any use of virtual in a function template. */
578 /* The debug-information generating code doesn't know what to do
579 with member templates. */
581 }
584 else
586 }
588 /* Sanity check: report error if this function FUNCTION is not
589 really a member of the class (CTYPE) it is supposed to belong to.
590 TEMPLATE_PARMS is used to specify the template parameters of a member
591 template passed as FUNCTION_DECL. If the member template is passed as a
592 TEMPLATE_DECL, it can be NULL since the parameters can be extracted
593 from the declaration. If the function is not a function template, it
594 must be NULL.
595 It returns the original declaration for the function, NULL_TREE if
596 no declaration was found, error_mark_node if an error was emitted. */
598 tree
600 {
605 /* Since this is a specialization of a member template,
606 we're not going to find the declaration in the class.
607 For example, in:
609 struct S { template <typename T> void f(T); };
610 template <> void S::f(int);
612 we're not going to find `S::f(int)', but there's no
613 reason we should, either. We let our callers know we didn't
614 find the method, but we don't complain. */
617 /* Basic sanity check: for a template function, the template parameters
618 either were not passed, or they are the same of DECL_TEMPLATE_PARMS. */
620 {
624 {
628 }
630 }
632 /* OK, is this a definition of a member template? */
635 /* [temp.mem]
637 A destructor shall not be a member template. */
639 {
642 }
644 /* We must enter the scope here, because conversion operators are
645 named by target type, and type equivalence relies on typenames
646 resolving within the scope of CTYPE. */
652 {
655 /* A member template definition only matches a member template
656 declaration. */
666 /* We cannot simply call decls_match because this doesn't work
667 for static member functions that are pretending to be
668 methods, and because the name may have been changed by
669 asm("new_name"). */
671 /* Get rid of the this parameter on functions that become
672 static. */
677 /* ref-qualifier or absence of same must match. */
682 // Include constraints in the match.
686 /* While finding a match, same types and params are not enough
687 if the function is versioned. Also check version ("target")
688 attributes. */
693 && (!is_template
702 }
705 {
708 else
709 {
720 else
725 }
727 }
733 }
735 /* DECL is a function with vague linkage. Remember it so that at the
736 end of the translation unit we can decide whether or not to emit
737 it. */
739 void
741 {
744 }
746 /* As above, but for variable template instantiations. */
748 void
750 {
752 }
754 /* We have just processed the DECL, which is a static data member.
755 The other parameters are as for cp_finish_decl. */
757 void
760 tree asmspec_tree,
762 {
765 /* We cannot call pushdecl here, because that would fill in the
766 TREE_CHAIN of our decl. Instead, we modify cp_finish_decl to do
767 the right thing, namely, to put this decl out straight away. */
773 /* We already complained about the template definition. */
777 else
781 {
787 }
796 {
797 /* Similarly to start_decl_1, we want to complete the type in order
798 to do the right thing in cp_apply_type_quals_to_decl, possibly
799 clear TYPE_QUAL_CONST (c++/65579). */
802 }
805 }
807 /* DECLARATOR and DECLSPECS correspond to a class member. The other
808 parameters are as for cp_finish_decl. Return the DECL for the
809 class member declared. */
811 tree
815 tree asmspec_tree,
816 tree attrlist)
817 {
818 tree value;
821 tree name;
831 /* friend or constructor went bad. */
837 {
840 }
842 /* Pass friendly classes back. */
850 {
852 {
855 }
860 value);
861 }
863 /* Stash away type declarations. */
865 {
870 {
873 /* If this is a typedef that names the class for linkage purposes
874 (7.1.3p8), apply any attributes directly to the type. */
880 }
887 /* It's important that push_template_decl below follows
888 set_underlying_type above so that the created template
889 carries the properly set type of VALUE. */
895 }
900 {
903 }
909 {
911 {
913 {
915 {
919 }
920 else
921 {
925 }
926 }
928 {
930 {
934 }
935 }
939 {
944 else
946 value);
947 }
948 else
949 {
953 value);
954 else
956 value);
957 }
958 }
963 }
965 /* Pass friend decls back. */
971 /* Need to set this before push_template_decl. */
976 {
980 }
987 else
991 {
1016 /* Pass friends back this way. */
1025 }
1027 }
1029 /* Like `grokfield', but for bitfields.
1030 WIDTH is the width of the bitfield, a constant expression.
1031 The other parameters are as for grokfield. */
1033 tree
1036 tree attrlist)
1037 {
1046 /* Pass friendly classes back. */
1053 {
1056 }
1059 {
1062 }
1064 /* Usually, finish_struct_1 catches bitfields with invalid types.
1065 But, in the case of bitfields with function type, we confuse
1066 ourselves into thinking they are member functions, so we must
1067 check here. */
1069 {
1073 }
1076 {
1080 }
1083 {
1087 }
1090 {
1093 }
1101 {
1102 /* The width must be an integer type. */
1107 else
1108 {
1109 /* Temporarily stash the width in DECL_BIT_FIELD_REPRESENTATIVE.
1110 check_bitfield_decl picks it from there later and sets DECL_SIZE
1111 accordingly. */
1114 }
1115 }
1123 }
1125 \f
1126 /* Returns true iff ATTR is an attribute which needs to be applied at
1127 instantiation time rather than template definition time. */
1129 static bool
1131 {
1135 tree arg;
1138 /* Unknown attribute. */
1141 /* Attribute weak handling wants to write out assembly right away. */
1145 /* Attributes used and unused are applied directly, as they appertain to
1146 decls. */
1151 /* Attribute tls_model wants to modify the symtab. */
1155 /* #pragma omp declare simd attribute needs to be always deferred. */
1160 /* An attribute pack is clearly dependent. */
1164 /* If any of the arguments are dependent expressions, we can't evaluate
1165 the attribute until instantiation time. */
1167 {
1170 /* If the first attribute argument is an identifier, only consider
1171 second and following arguments. Attributes like mode, format,
1172 cleanup and several target specific attributes aren't late
1173 just because they have an IDENTIFIER_NODE as first argument. */
1181 }
1186 {
1189 /* We can't apply any attributes to a completely unknown type until
1190 instantiation time. */
1196 /* Also defer most attributes on dependent types. This is not
1197 necessary in all cases, but is the better default. */
1199 /* But some attributes specifically apply to templates. */
1204 else
1206 }
1207 else
1209 }
1211 /* ATTR_P is a list of attributes. Remove any attributes which need to be
1212 applied at instantiation time and return them. If IS_DEPENDENT is true,
1213 the declaration itself is dependent, so all attributes should be applied
1214 at instantiation time. */
1216 static tree
1218 {
1227 {
1229 {
1235 }
1236 else
1238 }
1241 }
1243 /* Remove any late attributes from the list in ATTR_P and attach them to
1244 DECL_P. */
1246 static void
1248 {
1260 else
1265 /* Merge the late attributes at the beginning with the attribute
1266 list. */
1271 {
1274 else
1275 {
1278 }
1279 }
1280 else
1284 {
1285 /* We've added new attributes directly to the main variant, so
1286 now we need to update all of the other variants to include
1287 these new attributes. */
1288 tree variant;
1291 {
1294 }
1295 }
1296 }
1298 /* True if ATTRS contains any dependent attributes that affect type
1299 identity. */
1301 bool
1303 {
1306 {
1310 }
1312 }
1314 /* Return true iff ATTRS are acceptable attributes to be applied in-place
1315 to a typedef which gives a previously unnamed class or enum a name for
1316 linkage purposes. */
1318 bool
1320 {
1322 {
1326 }
1328 }
1330 /* Like reconstruct_complex_type, but handle also template trees. */
1332 tree
1334 {
1339 {
1343 }
1345 {
1349 }
1351 {
1354 /* Don't call cp_build_qualified_type on ARRAY_TYPEs, the
1355 element type qualification will be handled by the recursive
1356 cp_reconstruct_complex_type call and cp_build_qualified_type
1357 for ARRAY_TYPEs changes the element type. */
1359 }
1361 {
1368 }
1370 {
1373 /* The build_method_type_directly() routine prepends 'this' to argument list,
1374 so we must compensate by getting rid of it. */
1375 outer
1376 = build_method_type_directly
1379 }
1381 {
1384 }
1385 else
1396 }
1398 /* Replaces any constexpr expression that may be into the attributes
1399 arguments with their reduced value. */
1401 static void
1403 {
1407 tree attr;
1409 {
1410 tree arg;
1412 {
1416 }
1417 }
1418 }
1420 /* Return true if TYPE is an OpenMP mappable type. */
1421 bool
1423 {
1424 /* Mappable type has to be complete. */
1427 /* Arrays have mappable type if the elements have mappable type. */
1430 /* A mappable type cannot contain virtual members. */
1433 /* All data members must be non-static. */
1435 {
1436 tree field;
1440 /* All fields must have mappable types. */
1444 }
1446 }
1448 /* Return the last pushed declaration for the symbol DECL or NULL
1449 when no such declaration exists. */
1451 static tree
1453 {
1457 {
1458 /* Look up the declaration in its scope. */
1468 /* The declaration may be a member conversion operator
1469 or a bunch of overfloads (handle the latter below). */
1472 }
1478 {
1479 /* A set of overloads of the same function. */
1481 {
1487 }
1489 }
1492 }
1494 /* Like decl_attributes, but handle C++ complexity. */
1496 void
1498 {
1503 /* Add implicit "omp declare target" attribute if requested. */
1508 {
1518 else
1521 }
1524 {
1529 }
1537 {
1538 attributes
1542 }
1543 else
1544 {
1547 }
1552 /* Propagate deprecation out to the template. */
1555 {
1561 }
1562 }
1563 \f
1564 /* Walks through the namespace- or function-scope anonymous union
1565 OBJECT, with the indicated TYPE, building appropriate VAR_DECLs.
1566 Returns one of the fields for use in the mangled name. */
1568 static tree
1570 {
1572 tree field;
1574 /* Rather than write the code to handle the non-union case,
1575 just give an error. */
1577 {
1580 }
1585 {
1586 tree decl;
1587 tree ref;
1592 {
1594 "%q#D invalid; an anonymous union can only "
1597 }
1609 else
1614 {
1615 tree base;
1631 }
1634 else
1639 }
1642 }
1644 /* Finish off the processing of a UNION_TYPE structure. If the union is an
1645 anonymous union, then all members must be laid out together. PUBLIC_P
1646 is nonzero if this union is not declared static. */
1648 void
1650 {
1651 tree type;
1652 tree main_decl;
1661 /* The VAR_DECL's context is the same as the TYPE's context. */
1668 {
1671 }
1677 {
1680 }
1683 {
1684 /* Use main_decl to set the mangled name. */
1690 }
1694 }
1695 \f
1696 /* Auxiliary functions to make type signatures for
1697 `operator new' and `operator delete' correspond to
1698 what compiler will be expecting. */
1700 tree
1702 {
1709 {
1712 }
1715 {
1717 {
1718 /* [basic.stc.dynamic.allocation]
1720 The first parameter shall not have an associated default
1721 argument. */
1724 /* Throw away the default argument. */
1726 }
1729 {
1732 }
1733 }
1734 else
1742 {
1745 /* Fall through. */
1747 type = build_exception_variant
1750 /* Fall through. */
1752 }
1754 }
1756 tree
1758 {
1765 {
1768 }
1772 {
1777 ptr_type_node);
1778 }
1780 {
1783 /* Fall through. */
1785 type = build_exception_variant
1788 /* Fall through. */
1790 }
1793 }
1794 \f
1795 /* DECL is a VAR_DECL for a vtable: walk through the entries in the vtable
1796 and mark them as needed. */
1798 static void
1800 {
1801 tree fnaddr;
1804 /* It's OK for the vtable to refer to deprecated virtual functions. */
1809 {
1810 tree fn;
1816 /* This entry is an offset: a virtual base class offset, a
1817 virtual call offset, an RTTI offset, etc. */
1822 /* When we don't have vcall offsets, we output thunks whenever
1823 we output the vtables that contain them. With vcall offsets,
1824 we know all the thunks we'll need when we emit a virtual
1825 function, so we emit the thunks there instead. */
1829 }
1830 }
1832 /* Set DECL up to have the closest approximation of "initialized common"
1833 linkage available. */
1835 void
1837 {
1842 /* We can just emit function and compiler-generated variables
1843 statically; having multiple copies is (for the most part) only
1844 a waste of space.
1846 There are two correctness issues, however: the address of a
1847 template instantiation with external linkage should be the
1848 same, independent of what translation unit asks for the
1849 address, and this will not hold when we emit multiple copies of
1850 the function. However, there's little else we can do.
1852 Also, by default, the typeinfo implementation assumes that
1853 there will be only one copy of the string used as the name for
1854 each type. Therefore, if weak symbols are unavailable, the
1855 run-time library should perform a more conservative check; it
1856 should perform a string comparison, rather than an address
1857 comparison. */
1859 else
1860 {
1861 /* Static data member template instantiations, however, cannot
1862 have multiple copies. */
1867 {
1870 }
1872 {
1873 /* We can't do anything useful; leave vars for explicit
1874 instantiation. */
1877 }
1878 }
1882 }
1884 /* For win32 we also want to put explicit instantiations in
1885 linkonce sections, so that they will be merged with implicit
1886 instantiations; otherwise we get duplicate symbol errors.
1887 For Darwin we do not want explicit instantiations to be
1888 linkonce. */
1890 void
1892 {
1893 /* We used to say that this was not necessary on targets that support weak
1894 symbols, because the implicit instantiations will defer to the explicit
1895 one. However, that's not actually the case in SVR4; a strong definition
1896 after a weak one is an error. Also, not making explicit
1897 instantiations one_only means that we can end up with two copies of
1898 some template instantiations. */
1902 /* We can't set DECL_COMDAT on functions, or cp_finish_file will think
1903 we can get away with not emitting them if they aren't used. We need
1904 to for variables so that cp_finish_decl will update their linkage,
1905 because their DECL_INITIAL may not have been set properly yet. */
1910 {
1914 {
1917 /* Mark it needed so we don't forget to emit it. */
1920 }
1921 }
1922 }
1924 /* Returns true iff DECL, a FUNCTION_DECL or VAR_DECL, has vague linkage.
1925 This predicate will give the right answer during parsing of the
1926 function, which other tests may not. */
1928 bool
1930 {
1932 {
1933 /* maybe_thunk_body clears TREE_PUBLIC on the maybe-in-charge 'tor
1934 variants, check one of the "clones" for the real linkage. */
1943 }
1944 /* Unfortunately, import_export_decl has not always been called
1945 before the function is processed, so we cannot simply check
1946 DECL_COMDAT. */
1955 /* A local static in an inline effectively has vague linkage. */
1958 else
1960 }
1962 /* Determine whether or not we want to specifically import or export CTYPE,
1963 using various heuristics. */
1965 static void
1967 {
1968 /* -1 for imported, 1 for exported. */
1971 /* It only makes sense to call this function at EOF. The reason is
1972 that this function looks at whether or not the first non-inline
1973 non-abstract virtual member function has been defined in this
1974 translation unit. But, we can't possibly know that until we've
1975 seen the entire translation unit. */
1981 /* If MULTIPLE_SYMBOL_SPACES is set and we saw a #pragma interface,
1982 we will have CLASSTYPE_INTERFACE_ONLY set but not
1983 CLASSTYPE_INTERFACE_KNOWN. In that case, we don't want to use this
1984 heuristic because someone will supply a #pragma implementation
1985 elsewhere, and deducing it here would produce a conflict. */
1995 /* For a template class, without -fimplicit-templates, check the
1996 repository. If the virtual table is assigned to this
1997 translation unit, then export the class; otherwise, import
1998 it. */
2001 {
2002 /* The ABI specifies that the virtual table and associated
2003 information are emitted with the key method, if any. */
2005 /* If weak symbol support is not available, then we must be
2006 careful not to emit the vtable when the key function is
2007 inline. An inline function can be defined in multiple
2008 translation units. If we were to emit the vtable in each
2009 translation unit containing a definition, we would get
2010 multiple definition errors at link-time. */
2013 }
2015 /* When MULTIPLE_SYMBOL_SPACES is set, we cannot count on seeing
2016 a definition anywhere else. */
2020 /* Allow back ends the chance to overrule the decision. */
2025 {
2028 }
2029 }
2031 /* Return true if VAR has already been provided to the back end; in that
2032 case VAR should not be modified further by the front end. */
2033 static bool
2035 {
2037 }
2039 /* DECL is a VAR_DECL or FUNCTION_DECL which, for whatever reason,
2040 must be emitted in this translation unit. Mark it as such. */
2042 void
2044 {
2047 {
2048 /* Extern inline functions don't become needed when referenced.
2049 If we know a method will be emitted in other TU and no new
2050 functions can be marked reachable, just use the external
2051 definition. */
2055 /* #pragma interface and -frepo code can call mark_needed for
2056 maybe-in-charge 'tors; mark the clones as well. */
2057 tree clone;
2060 }
2062 {
2064 /* C++ frontend use mark_decl_references to force COMDAT variables
2065 to be output that might appear dead otherwise. */
2067 }
2068 }
2070 /* DECL is either a FUNCTION_DECL or a VAR_DECL. This function
2071 returns true if a definition of this entity should be provided in
2072 this object file. Callers use this function to determine whether
2073 or not to let the back end know that a definition of DECL is
2074 available in this translation unit. */
2076 bool
2078 {
2080 /* This function should only be called at the end of the translation
2081 unit. We cannot be sure of whether or not something will be
2082 COMDAT until that point. */
2085 /* All entities with external linkage that are not COMDAT/EXTERN should be
2086 emitted; they may be referred to from other object files. */
2089 /* Functions marked "dllexport" must be emitted so that they are
2090 visible to other DLLs. */
2095 /* When not optimizing, do not bother to produce definitions for extern
2096 symbols. */
2105 /* If this entity was used, let the back end see it; it will decide
2106 whether or not to emit it into the object file. */
2110 /* Virtual functions might be needed for devirtualization. */
2116 /* Otherwise, DECL does not need to be emitted -- yet. A subsequent
2117 reference to DECL might cause it to be emitted later. */
2119 }
2121 /* If necessary, write out the vtables for the dynamic class CTYPE.
2122 Returns true if any vtables were emitted. */
2124 static bool
2126 {
2127 tree vtbl;
2128 tree primary_vtbl;
2132 /* If the vtables for this class have already been emitted there is
2133 nothing more to do. */
2137 /* Ignore dummy vtables made by get_vtable_decl. */
2141 /* On some targets, we cannot determine the key method until the end
2142 of the translation unit -- which is when this function is
2143 called. */
2147 /* See if any of the vtables are needed. */
2149 {
2153 }
2155 {
2156 /* If the references to this class' vtables are optimized away,
2157 still emit the appropriate debugging information. See
2158 dfs_debug_mark. */
2163 }
2165 /* The ABI requires that we emit all of the vtables if we emit any
2166 of them. */
2168 {
2169 /* Mark entities references from the virtual table as used. */
2173 {
2176 LOOKUP_NORMAL);
2178 /* It had better be all done at compile-time. */
2180 }
2182 /* Write it out. */
2186 /* Because we're only doing syntax-checking, we'll never end up
2187 actually marking the variable as written. */
2191 {
2196 }
2197 }
2199 /* Since we're writing out the vtable here, also write the debug
2200 info. */
2204 }
2206 /* A special return value from type_visibility meaning internal
2207 linkage. */
2211 /* walk_tree helper function for type_visibility. */
2213 static tree
2215 {
2218 {
2220 }
2223 {
2226 }
2231 }
2233 /* Returns the visibility of TYPE, which is the minimum visibility of its
2234 component types. */
2236 static int
2238 {
2242 }
2244 /* Limit the visibility of DECL to VISIBILITY, if not explicitly
2245 specified (or if VISIBILITY is static). If TMPL is true, this
2246 constraint is for a template argument, and takes precedence
2247 over explicitly-specified visibility on the template. */
2249 static void
2251 {
2253 {
2254 /* extern "C" declarations aren't affected by the anonymous
2255 namespace. */
2257 {
2263 {
2268 }
2272 }
2273 }
2276 {
2278 /* This visibility was not specified. */
2280 }
2281 }
2283 /* Constrain the visibility of DECL based on the visibility of its template
2284 arguments. */
2286 static void
2288 {
2289 /* If this is a template instantiation, check the innermost
2290 template args for visibility constraints. The outer template
2291 args are covered by the class check. */
2295 {
2301 else
2302 {
2310 {
2313 else
2315 }
2316 }
2319 }
2320 }
2322 /* Like c_determine_visibility, but with additional C++-specific
2323 behavior.
2325 Function-scope entities can rely on the function's visibility because
2326 it is set in start_preparsed_function.
2328 Class-scope entities cannot rely on the class's visibility until the end
2329 of the enclosing class definition.
2331 Note that because namespaces have multiple independent definitions,
2332 namespace visibility is handled elsewhere using the #pragma visibility
2333 machinery rather than by decorating the namespace declaration.
2335 The goal is for constraints from the type to give a diagnostic, and
2336 other constraints to be applied silently. */
2338 void
2340 {
2341 /* Remember that all decls get VISIBILITY_DEFAULT when built. */
2343 /* Only relevant for names with external linkage. */
2347 /* Cloned constructors and destructors get the same visibility as
2348 the underlying function. That should be set up in
2349 maybe_clone_body. */
2355 /* The decl may be a template instantiation, which could influence
2356 visibilty. */
2359 {
2361 {
2364 }
2367 }
2371 /* If DECL is a member of a class, visibility specifiers on the
2372 class can influence the visibility of the DECL. */
2376 else
2377 {
2378 /* Not a class member. */
2380 /* Virtual tables have DECL_CONTEXT set to their associated class,
2381 so they are automatically handled above. */
2386 {
2387 /* Local statics and classes get the visibility of their
2388 containing function by default, except that
2389 -fvisibility-inlines-hidden doesn't affect them. */
2392 {
2396 }
2397 else
2398 {
2402 {
2406 }
2407 else
2408 {
2412 }
2413 }
2415 /* Local classes in templates have CLASSTYPE_USE_TEMPLATE set,
2416 but have no TEMPLATE_INFO. Their containing template
2417 function does, and the local class could be constrained
2418 by that. */
2422 {
2423 /* FN must be a regenerated lambda function, since they don't
2424 have template arguments. Find a containing non-lambda
2425 template instantiation. */
2430 }
2431 }
2434 {
2435 /* Under -fvisibility-ms-compat, types are visible by default,
2436 even though their contents aren't. */
2443 else
2445 }
2447 {
2448 /* tinfo visibility is based on the type it's for. */
2449 constrain_visibility
2452 /* Give the target a chance to override the visibility associated
2453 with DECL. */
2459 }
2461 /* Template instantiations and specializations get visibility based
2464 {
2467 else
2468 {
2469 /* Set default visibility to whatever the user supplied with
2470 #pragma GCC visibility or a namespace visibility attribute. */
2473 }
2474 }
2475 }
2478 {
2479 /* If the specialization doesn't specify visibility, use the
2480 visibility from the template. */
2488 {
2492 {
2496 else
2497 {
2501 }
2502 }
2505 /* Template argument visibility outweighs #pragma or namespace
2506 visibility, but not an explicit attribute. */
2508 {
2511 {
2512 /* A class template member with explicit visibility
2513 overrides the class visibility, so we need to apply
2514 all the levels of template args directly. */
2517 {
2520 }
2521 }
2523 /* Limit visibility based on its template arguments. */
2525 }
2526 }
2527 }
2533 /* Names in an anonymous namespace get internal linkage.
2534 This might change once we implement export. */
2537 {
2538 /* Propagate anonymity from type to decl. */
2543 }
2545 /* DR 757: A type without linkage shall not be used as the type of a
2546 variable or function with linkage, unless
2547 o the variable or function has extern "C" linkage (7.5 [dcl.link]), or
2548 o the variable or function is not used (3.2 [basic.def.odr]) or is
2549 defined in the same translation unit.
2551 Since non-extern "C" decls need to be defined in the same
2552 translation unit, we can make the type internal. */
2555 /* If visibility changed and DECL already has DECL_RTL, ensure
2556 symbol flags are updated. */
2563 }
2565 /* By default, static data members and function members receive
2566 the visibility of their containing class. */
2568 static void
2570 {
2576 else
2577 {
2578 /* Default to the class visibility. */
2582 }
2584 /* Give the target a chance to override the visibility associated
2585 with DECL. */
2589 /* Construction virtual tables are not exported because
2590 they cannot be referred to from other object files;
2591 their name is not standardized by the ABI. */
2597 }
2599 /* Returns true iff DECL is an inline that should get hidden visibility
2600 because of -fvisibility-inlines-hidden. */
2602 static bool
2604 {
2606 /* Don't do this for inline templates; specializations might not be
2607 inline, and we don't want them to inherit the hidden
2608 visibility. We'll set it here for all inline instantiations. */
2609 && !processing_template_decl
2614 }
2616 /* Constrain the visibility of a class TYPE based on the visibility of its
2617 field types. Warn if any fields require lesser visibility. */
2619 void
2621 {
2622 tree binfo;
2623 tree t;
2632 /* Don't warn about visibility if the class has explicit visibility. */
2639 {
2644 {
2646 {
2649 {
2654 else
2658 }
2659 else
2663 }
2664 }
2671 }
2675 {
2679 {
2681 {
2684 {
2689 else
2693 }
2694 else
2698 }
2699 }
2705 }
2706 }
2708 /* Functions for adjusting the visibility of a tagged type and its nested
2709 types and declarations when it gets a name for linkage purposes from a
2710 typedef. */
2715 /* First reset the visibility of all the types. */
2717 static void
2719 {
2724 }
2725 static void
2727 {
2729 }
2731 /* Then reset the visibility of any static data members or member
2732 functions that use those types. */
2734 static void
2736 {
2745 }
2747 static void
2749 {
2751 {
2753 {
2758 }
2760 {
2766 }
2768 {
2772 }
2775 }
2776 }
2778 static void
2780 {
2782 }
2783 void
2785 {
2788 }
2790 /* Set up our initial idea of what the linkage of DECL should be. */
2792 void
2794 {
2796 /* We've already made a decision as to how this function will
2799 {
2802 {
2806 /* A non-template inline function with external linkage will
2807 always be COMDAT. As we must eventually determine the
2808 linkage of all functions, and as that causes writes to
2809 the data mapped in from the PCH file, it's advantageous
2810 to mark the functions at this point. */
2814 {
2815 /* This function must have external linkage, as
2816 otherwise DECL_INTERFACE_KNOWN would have been
2817 set. */
2821 }
2822 }
2825 }
2826 }
2828 /* DECL is a FUNCTION_DECL or VAR_DECL. If the object file linkage
2829 for DECL has not already been determined, do so now by setting
2830 DECL_EXTERNAL, DECL_COMDAT and other related flags. Until this
2831 function is called entities with vague linkage whose definitions
2832 are available must have TREE_PUBLIC set.
2834 If this function decides to place DECL in COMDAT, it will set
2835 appropriate flags -- but will not clear DECL_EXTERNAL. It is up to
2836 the caller to decide whether or not to clear DECL_EXTERNAL. Some
2837 callers defer that decision until it is clear that DECL is actually
2838 required. */
2840 void
2842 {
2851 /* We cannot determine what linkage to give to an entity with vague
2852 linkage until the end of the file. For example, a virtual table
2853 for a class will be defined if and only if the key method is
2854 defined in this translation unit. As a further example, consider
2855 that when compiling a translation unit that uses PCH file with
2856 "-frepo" it would be incorrect to make decisions about what
2857 entities to emit when building the PCH; those decisions must be
2858 delayed until the repository information has been processed. */
2860 /* Object file linkage for explicit instantiations is handled in
2861 mark_decl_instantiated. For static variables in functions with
2862 vague linkage, maybe_commonize_var is used.
2864 Therefore, the only declarations that should be provided to this
2865 function are those with external linkage that are:
2867 * implicit instantiations of function templates
2869 * inline function
2871 * implicit instantiations of static data members of class
2872 templates
2874 * virtual tables
2876 * typeinfo objects
2878 Furthermore, all entities that reach this point must have a
2879 definition available in this translation unit.
2881 The following assertions check these conditions. */
2883 /* Any code that creates entities with TREE_PUBLIC cleared should
2884 also set DECL_INTERFACE_KNOWN. */
2890 else
2894 /* Check that a definition of DECL is available in this translation
2895 unit. */
2898 /* Assume that DECL will not have COMDAT linkage. */
2900 /* Assume that DECL will not be imported into this translation
2901 unit. */
2904 /* See if the repository tells us whether or not to emit DECL in
2905 this translation unit. */
2910 {
2911 /* The repository indicates that this entity should be defined
2912 here. Make sure the back end honors that request. */
2914 /* Output the definition as an ordinary strong definition. */
2918 }
2921 /* We have already decided what to do with this DECL; there is no
2922 need to check anything further. */
2923 ;
2925 {
2935 /* The ABI requires that all virtual tables be emitted with
2936 COMDAT linkage. However, on systems where COMDAT symbols
2937 don't show up in the table of contents for a static
2938 archive, or on systems without weak symbols (where we
2939 approximate COMDAT linkage by using internal linkage), the
2940 linker will report errors about undefined symbols because
2941 it will not see the virtual table definition. Therefore,
2942 in the case that we know that the virtual table will be
2943 emitted in only one translation unit, we make the virtual
2944 table an ordinary definition with external linkage. */
2947 {
2948 /* CLASS_TYPE is being exported from this translation unit,
2949 so DECL should be defined here. */
2951 /* If a class is declared in a header with the "extern
2952 template" extension, then it will not be instantiated,
2953 even in translation units that would normally require
2954 it. Often such classes are explicitly instantiated in
2955 one translation unit. Therefore, the explicit
2956 instantiation must be made visible to other translation
2957 units. */
2959 else
2960 {
2961 /* The generic C++ ABI says that class data is always
2962 COMDAT, even if there is a key function. Some
2963 variants (e.g., the ARM EABI) says that class data
2964 only has COMDAT linkage if the class data might be
2965 emitted in more than one translation unit. When the
2966 key method can be inline and is inline, we still have
2967 to arrange for comdat even though
2968 class_data_always_comdat is false. */
2972 {
2973 /* The ABI requires COMDAT linkage. Normally, we
2974 only emit COMDAT things when they are needed;
2975 make sure that we realize that this entity is
2976 indeed needed. */
2979 }
2980 }
2981 }
2985 else
2987 }
2989 {
2992 {
2998 /* If -fno-rtti was specified, then we cannot be sure
2999 that RTTI information will be emitted with the
3000 virtual table of the class, so we must emit it
3001 wherever it is used. */
3004 else
3005 {
3008 {
3014 {
3017 }
3018 }
3019 else
3021 }
3022 }
3023 else
3025 }
3027 {
3028 /* DECL is an implicit instantiation of a function or static
3029 data member. */
3032 || (flag_implicit_inline_templates
3036 else
3037 /* If we are not implicitly generating templates, then mark
3038 this entity as undefined in this translation unit. */
3040 }
3042 {
3044 {
3048 {
3052 && ! flag_implement_inlines
3058 /* Always make artificials weak. */
3061 else
3063 }
3064 }
3065 else
3067 }
3068 else
3072 {
3073 /* If we are importing DECL into this translation unit, mark is
3074 an undefined here. */
3077 }
3079 {
3080 /* If we decided to put DECL in COMDAT, mark it accordingly at
3081 this point. */
3083 }
3086 }
3088 /* Return an expression that performs the destruction of DECL, which
3089 must be a VAR_DECL whose type has a non-trivial destructor, or is
3090 an array whose (innermost) elements have a non-trivial destructor. */
3092 tree
3094 {
3098 }
3100 /* Returns the initialization guard variable for the variable DECL,
3101 which has static storage duration. */
3103 tree
3105 {
3106 tree sname;
3107 tree guard;
3112 {
3113 tree guard_type;
3115 /* We use a type that is big enough to contain a mutex as well
3116 as an integer counter. */
3121 /* The guard should have the same linkage as what it guards. */
3139 }
3141 }
3143 /* Return an atomic load of src with the appropriate memory model. */
3145 static tree
3147 {
3162 }
3164 /* Return those bits of the GUARD variable that should be set when the
3165 guarded entity is actually initialized. */
3167 static tree
3169 {
3171 {
3172 /* We only set the first byte of the guard, in order to leave room
3173 for a mutex in the high-order bits. */
3176 guard);
3179 guard);
3181 }
3184 }
3186 /* Return an expression which determines whether or not the GUARD
3187 variable has already been initialized. */
3189 tree
3191 {
3192 tree guard_value;
3196 else
3199 /* Mask off all but the low bit. */
3201 {
3207 tf_warning_or_error);
3208 }
3215 tf_warning_or_error);
3216 }
3218 /* Return an expression which sets the GUARD variable, indicating that
3219 the variable being guarded has been initialized. */
3221 tree
3223 {
3224 tree guard_init;
3226 /* Set the GUARD to one. */
3232 tf_warning_or_error);
3233 }
3235 /* Returns true iff we can tell that VAR does not have a dynamic
3236 initializer. */
3238 static bool
3240 {
3241 /* If it's defined in another TU, we can't tell. */
3244 /* If it has a non-trivial destructor, registering the destructor
3245 counts as dynamic initialization. */
3248 /* If it's in this TU, its initializer has been processed, unless
3249 it's a case of self-initialization, then DECL_INITIALIZED_P is
3250 false while the initializer is handled by finish_id_expression. */
3253 /* If it has no initializer or a constant one, it's not dynamic. */
3256 }
3258 /* Returns true iff VAR is a variable that needs uses to be
3259 wrapped for possible dynamic initialization. */
3261 static bool
3263 {
3269 }
3271 /* Get the FUNCTION_DECL for the shared TLS init function for this
3272 translation unit. */
3274 static tree
3276 {
3280 {
3283 void_list_node));
3289 }
3291 }
3293 /* Get a FUNCTION_DECL for the init function for the thread_local
3294 variable VAR. The init function will be an alias to the function
3295 that initializes all the non-local TLS variables in the translation
3296 unit. The init function is only used by the wrapper function. */
3298 static tree
3300 {
3301 /* Only C++11 TLS vars need this init fn. */
3305 /* If -fno-extern-tls-init, assume that we don't need to call
3306 a tls init function for a variable defined in another TU. */
3310 /* If the variable is internal, or if we can't generate aliases,
3311 call the local init function directly. */
3318 {
3321 void_list_node));
3330 {
3332 /* If the variable is defined somewhere else and might have static
3333 initialization, make the init function a weak reference. */
3339 else
3341 }
3351 }
3353 }
3355 /* Get a FUNCTION_DECL for the init wrapper function for the thread_local
3356 variable VAR. The wrapper function calls the init function (if any) for
3357 VAR and then returns a reference to VAR. The wrapper function is used
3358 in place of VAR everywhere VAR is mentioned. */
3360 tree
3362 {
3363 /* Only C++11 TLS vars need this wrapper fn. */
3370 {
3371 /* A named rvalue reference is an lvalue, so the wrapper should
3372 always return an lvalue reference. */
3381 /* The wrapper is inline and emitted everywhere var is used. */
3384 {
3386 #ifdef HAVE_GAS_HIDDEN
3387 /* Make the wrapper bind locally; there's no reason to share
3388 the wrapper between multiple shared objects. */
3391 #endif
3392 }
3398 #if 0
3399 /* We want CSE to commonize calls to the wrapper, but marking it as
3400 pure is unsafe since it has side-effects. I guess we need a new
3401 ECF flag even weaker than ECF_PURE. FIXME! */
3403 #endif
3408 }
3410 }
3412 /* At EOF, generate the definition for the TLS wrapper function FN:
3414 T& var_wrapper() {
3415 if (init_fn) init_fn();
3416 return var;
3417 } */
3419 static void
3421 {
3426 /* Only call the init fn if there might be one. */
3428 {
3430 /* If init_fn is a weakref, make sure it exists before calling. */
3432 {
3437 tf_warning_or_error);
3439 }
3443 {
3446 }
3447 }
3448 else
3449 /* If there's no initialization, the wrapper is a constant function. */
3454 }
3456 /* Start the process of running a particular set of global constructors
3457 or destructors. Subroutine of do_[cd]tors. Also called from
3458 vtv_start_verification_constructor_init_function. */
3460 static tree
3462 {
3463 tree body;
3464 tree fndecl;
3467 /* Make ctor or dtor function. METHOD_TYPE may be 'I' or 'D'. */
3470 {
3473 #ifdef JOINER
3475 #else
3477 #endif
3480 }
3481 else
3487 NULL_TREE));
3492 /* Mark as artificial because it's not explicitly in the user's
3493 source code. */
3496 /* Mark this declaration as used to avoid spurious warnings. */
3499 /* Mark this function as a global constructor or destructor. */
3502 else
3508 }
3510 /* Finish the process of running a particular set of global constructors
3511 or destructors. Subroutine of do_[cd]tors. */
3513 static void
3515 {
3516 tree fn;
3518 /* Finish up. */
3523 {
3526 }
3527 else
3528 {
3531 }
3534 }
3536 /* The names of the parameters to the function created to handle
3537 initializations and destructions for objects with static storage
3538 duration. */
3542 /* The name of the function we create to handle initializations and
3543 destructions for objects with static storage duration. */
3546 /* The declaration for the __INITIALIZE_P argument. */
3549 /* The declaration for the __PRIORITY argument. */
3552 /* The declaration for the static storage duration function. */
3555 /* All the static storage duration functions created in this
3556 translation unit. */
3559 /* A map from priority levels to information about that priority
3560 level. There may be many such levels, so efficient lookup is
3561 important. */
3564 /* Begins the generation of the function that will handle all
3565 initialization and destruction of objects with static storage
3566 duration. The function generated takes two parameters of type
3567 `int': __INITIALIZE_P and __PRIORITY. If __INITIALIZE_P is
3568 nonzero, it performs initializations. Otherwise, it performs
3569 destructions. It only performs those initializations or
3570 destructions with the indicated __PRIORITY. The generated function
3571 returns no value.
3573 It is assumed that this function will only be called once per
3574 translation unit. */
3576 static tree
3578 {
3579 tree type;
3580 tree body;
3583 /* Create the identifier for this function. It will be of the form
3584 SSDF_IDENTIFIER_<number>. */
3589 NULL_TREE);
3591 /* Create the FUNCTION_DECL itself. */
3594 type);
3598 /* Put this function in the list of functions to be called from the
3599 static constructors and destructors. */
3601 {
3604 /* Take this opportunity to initialize the map from priority
3605 numbers to information about that priority level. */
3608 /*delete_value_fn=*/
3612 /* We always need to generate functions for the
3613 DEFAULT_INIT_PRIORITY so enter it now. That way when we walk
3614 priorities later, we'll be sure to find the
3615 DEFAULT_INIT_PRIORITY. */
3617 }
3621 /* Create the argument list. */
3622 initialize_p_decl = cp_build_parm_decl
3625 priority_decl = cp_build_parm_decl
3632 /* Put the function in the global scope. */
3635 /* Start the function itself. This is equivalent to declaring the
3636 function as:
3638 static void __ssdf (int __initialize_p, init __priority_p);
3640 It is static because we only need to call this function from the
3641 various constructor and destructor functions for this module. */
3644 SF_PRE_PARSED);
3646 /* Set up the scope of the outermost block in the function. */
3650 }
3652 /* Finish the generation of the function which performs initialization
3653 and destruction of objects with static storage duration. After
3654 this point, no more such objects can be created. */
3656 static void
3658 {
3659 /* Close out the function. */
3662 }
3664 /* Return the information about the indicated PRIORITY level. If no
3665 code to handle this level has yet been generated, generate the
3666 appropriate prologue. */
3668 static priority_info
3670 {
3671 priority_info pi;
3672 splay_tree_node n;
3677 {
3678 /* Create a new priority information structure, and insert it
3679 into the map. */
3686 }
3687 else
3691 }
3693 /* The effective initialization priority of a DECL. */
3695 #define DECL_EFFECTIVE_INIT_PRIORITY(decl) \
3696 ((!DECL_HAS_INIT_PRIORITY_P (decl) || DECL_INIT_PRIORITY (decl) == 0) \
3697 ? DEFAULT_INIT_PRIORITY : DECL_INIT_PRIORITY (decl))
3699 /* Whether a DECL needs a guard to protect it against multiple
3700 initialization. */
3702 #define NEEDS_GUARD_P(decl) (TREE_PUBLIC (decl) && (DECL_COMMON (decl) \
3703 || DECL_ONE_ONLY (decl) \
3704 || DECL_WEAK (decl)))
3706 /* Called from one_static_initialization_or_destruction(),
3707 via walk_tree.
3708 Walks the initializer list of a global variable and looks for
3709 temporary variables (DECL_NAME() == NULL and DECL_ARTIFICIAL != 0)
3710 and that have their DECL_CONTEXT() == NULL.
3711 For each such temporary variable, set their DECL_CONTEXT() to
3712 the current function. This is necessary because otherwise
3713 some optimizers (enabled by -O2 -fprofile-arcs) might crash
3714 when trying to refer to a temporary variable that does not have
3715 it's DECL_CONTECT() properly set. */
3716 static tree
3720 {
3724 {
3725 tree var;
3733 }
3736 }
3738 /* Set up to handle the initialization or destruction of DECL. If
3739 INITP is nonzero, we are initializing the variable. Otherwise, we
3740 are destroying it. */
3742 static void
3744 {
3746 tree guard;
3748 /* If we are supposed to destruct and there's a trivial destructor,
3749 nothing has to be done. */
3754 /* Trick the compiler into thinking we are at the file and line
3755 where DECL was declared so that error-messages make sense, and so
3756 that the debugger will show somewhat sensible file and line
3757 information. */
3760 /* Make sure temporary variables in the initialiser all have
3761 their DECL_CONTEXT() set to a value different from NULL_TREE.
3762 This can happen when global variables initializers are built.
3763 In that case, the DECL_CONTEXT() of the global variables _AND_ of all
3764 the temporary variables that might have been generated in the
3765 accompanying initializers is NULL_TREE, meaning the variables have been
3766 declared in the global namespace.
3767 What we want to do here is to fix that and make sure the DECL_CONTEXT()
3768 of the temporaries are set to the current function decl. */
3770 fix_temporary_vars_context_r,
3771 NULL);
3773 /* Because of:
3775 [class.access.spec]
3777 Access control for implicit calls to the constructors,
3778 the conversion functions, or the destructor called to
3779 create and destroy a static data member is performed as
3780 if these calls appeared in the scope of the member's
3781 class.
3783 we pretend we are in a static member function of the class of
3784 which the DECL is a member. */
3786 {
3789 }
3791 /* Assume we don't need a guard. */
3793 /* We need a guard if this is an object with external linkage that
3794 might be initialized in more than one place. (For example, a
3795 static data member of a template, when the data member requires
3796 construction.) */
3798 {
3799 tree guard_cond;
3803 /* When using __cxa_atexit, we just check the GUARD as we would
3804 for a local static. */
3806 {
3807 /* When using __cxa_atexit, we never try to destroy
3808 anything from a static destructor. */
3811 }
3812 /* If we don't have __cxa_atexit, then we will be running
3813 destructors from .fini sections, or their equivalents. So,
3814 we need to know how many times we've tried to initialize this
3815 object. We do initializations only if the GUARD is zero,
3816 i.e., if we are the first to initialize the variable. We do
3817 destructions only if the GUARD is one, i.e., if we are the
3818 last to destroy the variable. */
3820 guard_cond
3822 EQ_EXPR,
3824 guard,
3826 tf_warning_or_error),
3827 integer_one_node,
3828 tf_warning_or_error);
3829 else
3830 guard_cond
3832 EQ_EXPR,
3834 guard,
3836 tf_warning_or_error),
3837 integer_zero_node,
3838 tf_warning_or_error);
3842 }
3845 /* If we're using __cxa_atexit, we have not already set the GUARD,
3846 so we must do so now. */
3850 /* Perform the initialization or destruction. */
3852 {
3854 {
3857 {
3861 }
3862 }
3864 /* If we're using __cxa_atexit, register a function that calls the
3865 destructor for the object. */
3868 }
3869 else
3872 /* Finish the guard if-stmt, if necessary. */
3874 {
3877 }
3879 /* Now that we're done with DECL we don't need to pretend to be a
3880 member of its class any longer. */
3883 }
3885 /* Generate code to do the initialization or destruction of the decls in VARS,
3886 a TREE_LIST of VAR_DECL with static storage duration.
3887 Whether initialization or destruction is performed is specified by INITP. */
3889 static void
3891 {
3894 /* Build the outer if-stmt to check for initialization or destruction. */
3898 EQ_EXPR,
3899 initialize_p_decl,
3900 cond,
3901 tf_warning_or_error);
3904 /* To make sure dynamic construction doesn't access globals from other
3905 compilation units where they might not be yet constructed, for
3906 -fsanitize=address insert __asan_before_dynamic_init call that
3907 prevents access to either all global variables that need construction
3908 in other compilation units, or at least those that haven't been
3909 initialized yet. Variables that need dynamic construction in
3910 the current compilation unit are kept accessible. */
3917 tree priority_if_stmt;
3919 priority_info pi;
3921 /* If we don't need a destructor, there's nothing to do. Avoid
3922 creating a possibly empty if-stmt. */
3924 {
3927 }
3929 /* Remember that we had an initialization or finalization at this
3930 priority. */
3935 else
3938 /* Conditionalize this initialization on being in the right priority
3939 and being initializing/finalizing appropriately. */
3942 EQ_EXPR,
3943 priority_decl,
3945 tf_warning_or_error);
3948 /* Process initializers with same priority. */
3952 /* Do one initialization or destruction. */
3956 /* Finish up the priority if-stmt body. */
3962 /* Revert what __asan_before_dynamic_init did by calling
3963 __asan_after_dynamic_init. */
3967 /* Finish up the init/destruct if-stmt body. */
3970 }
3972 /* VARS is a list of variables with static storage duration which may
3973 need initialization and/or finalization. Remove those variables
3974 that don't really need to be initialized or finalized, and return
3975 the resulting list. The order in which the variables appear in
3976 VARS is in reverse order of the order in which they should actually
3977 be initialized. The list we return is in the unreversed order;
3978 i.e., the first variable should be initialized first. */
3980 static tree
3982 {
3987 {
3992 /* Deal gracefully with error. */
3994 {
3997 }
3999 /* The only things that can be initialized are variables. */
4002 /* If this object is not defined, we don't need to do anything
4003 here. */
4005 {
4008 }
4010 /* Also, if the initializer already contains errors, we can bail
4011 out now. */
4014 {
4017 }
4019 /* This variable is going to need initialization and/or
4020 finalization, so we add it to the list. */
4024 }
4027 }
4029 /* Make sure we have told the back end about all the variables in
4030 VARS. */
4032 static void
4034 {
4035 tree v;
4038 {
4041 {
4044 }
4045 }
4046 }
4048 /* Generate a static constructor (if CONSTRUCTOR_P) or destructor
4049 (otherwise) that will initialize all global objects with static
4050 storage duration having the indicated PRIORITY. */
4052 static void
4055 {
4057 tree fndecl;
4058 tree body;
4062 /* ??? */
4063 /* Was: locus->line++; */
4065 /* We use `I' to indicate initialization and `D' to indicate
4066 destruction. */
4069 /* We emit the function lazily, to avoid generating empty
4070 global constructors and destructors. */
4073 /* For Objective-C++, we may need to initialize metadata found in this module.
4074 This must be done _before_ any other static initializations. */
4077 {
4080 }
4082 /* Call the static storage duration function with appropriate
4083 arguments. */
4085 {
4086 /* Calls to pure or const functions will expand to nothing. */
4088 {
4089 tree call;
4096 constructor_p),
4098 priority),
4099 NULL_TREE);
4101 }
4102 }
4104 /* Close out the function. */
4107 }
4109 /* Generate constructor and destructor functions for the priority
4110 indicated by N. */
4112 static int
4114 {
4119 /* Generate the functions themselves, but only if they are really
4120 needed. */
4126 /* Keep iterating. */
4128 }
4130 /* Return C++ property of T, based on given operation OP. */
4132 static int
4134 {
4136 {
4138 {
4146 }
4163 }
4164 }
4166 /* Collect source file references recursively, starting from NAMESPC. */
4168 static void
4170 {
4171 /* Iterate over names in this name space. */
4174 ;
4177 else
4179 }
4181 /* Collect decls relevant to SOURCE_FILE from all namespaces recursively,
4182 starting from NAMESPC. */
4184 static void
4186 {
4189 /* Collect decls from this namespace. This will skip
4190 NAMESPACE_DECLs (both aliases and regular, it cannot tell). */
4193 /* Now scan for namespace children, and dump them. */
4197 }
4199 /* Returns true iff there is a definition available for variable or
4200 function DECL. */
4202 bool
4204 {
4207 /* A pending instantiation of a friend temploid is defined. */
4211 else
4212 {
4215 }
4216 }
4218 /* Nonzero for a VAR_DECL whose value can be used in a constant expression.
4220 [expr.const]
4222 An integral constant-expression can only involve ... const
4223 variables of integral or enumeration types initialized with
4224 constant expressions ...
4226 C++0x also allows constexpr variables and temporaries initialized
4227 with constant expressions. We handle the former here, but the latter
4228 are just folded away in cxx_eval_constant_expression.
4230 The standard does not require that the expression be non-volatile.
4231 G++ implements the proposed correction in DR 457. */
4233 bool
4235 {
4239 /* We don't know if a template static data member is initialized with
4240 a constant expression until we instantiate its initializer. Even
4241 in the case of a constexpr variable, we can't treat it as a
4242 constant until its initializer is complete in case it's used in
4243 its own initializer. */
4246 }
4248 /* Returns true if DECL could be a symbolic constant variable, depending on
4249 its initializer. */
4251 bool
4253 {
4260 /* A proxy isn't constant. */
4267 else
4272 /* We know the initializer, and it isn't constant. */
4274 else
4276 }
4278 /* Complain that DECL uses a type with no linkage. In C++98 mode this is
4279 called from grokfndecl and grokvardecl; in all modes it is called from
4280 cp_write_global_declarations. */
4282 void
4284 {
4286 /* In C++11 it's ok if the decl is defined. */
4290 /* The type that got us on no_linkage_decls must have gotten a name for
4293 /* The type might end up having a typedef name for linkage purposes. */
4296 {
4304 /* DRs 132, 319 and 389 seem to indicate types with
4305 no linkage can only be used to declare extern "C"
4306 entities. Since it's not always an error in the
4307 ISO C++ 90 Standard, we only issue a warning. */
4309 "with no linkage used to declare variable %q#D with "
4311 else
4314 decl);
4319 }
4321 {
4324 "%q#D, declared using local type "
4326 }
4330 else
4333 }
4335 /* Collect declarations from all namespaces relevant to SOURCE_FILE. */
4337 static void
4339 {
4341 }
4343 /* Clear DECL_EXTERNAL for NODE. */
4345 static bool
4347 {
4350 }
4352 /* Build up the function to run dynamic initializers for thread_local
4353 variables in this translation unit and alias the init functions for the
4354 individual variables to it. */
4356 static void
4358 {
4368 boolean_type_node);
4383 tf_warning_or_error);
4386 boolean_true_node,
4387 tf_warning_or_error));
4389 {
4394 /* Output init aliases even with -fno-extern-tls-init. */
4396 {
4400 cgraph_node *alias
4404 }
4405 }
4411 }
4413 /* We're at the end of compilation, so generate any mangling aliases that
4414 we've been saving up, if DECL is going to be output and ID2 isn't
4415 already taken by another declaration. */
4417 static void
4419 {
4423 {
4426 /* Don't create an alias to an unreferenced function. */
4428 }
4430 tree *slot
4432 INSERT);
4434 /* If there's a declaration already using this mangled name,
4435 don't create a compatibility alias that conflicts. */
4450 else
4452 }
4454 /* Note that we might want to emit an alias with the symbol ID2 for DECL at
4455 the end of translation, for compatibility across bugs in the mangling
4456 implementation. */
4458 void
4460 {
4462 {
4465 else
4466 {
4469 }
4470 }
4471 }
4473 /* Emit all mangling aliases that were deferred up to this point. */
4475 void
4477 {
4479 {
4483 }
4485 }
4487 /* Record a mangling of DECL, whose DECL_ASSEMBLER_NAME has just been
4488 set. NEED_WARNING is true if we must warn about collisions. We do
4489 this to spot changes in mangling that may require compatibility
4490 aliases. */
4492 void
4494 {
4500 tree *slot
4502 INSERT);
4504 /* If this is already an alias, remove the alias, because the real
4505 decl takes precedence. */
4509 {
4512 }
4517 {
4524 "a later -fabi-version= (or =0)"
4527 }
4528 }
4530 /* The mangled name of DECL is being forcibly changed to NAME. Remove
4531 any existing knowledge of DECL's mangled name meaning DECL. */
4533 void
4535 {
4542 NO_INSERT))
4544 {
4547 /* If this is an alias, remove it from the symbol table. */
4552 }
4555 }
4557 /* The entire file is now complete. If requested, dump everything
4558 to a file. */
4560 static void
4562 {
4563 dump_flags_t flags;
4565 {
4568 }
4569 }
4573 /* Check the deallocation functions for CODE to see if we want to warn that
4574 only one was defined. */
4576 static void
4578 {
4584 {
4586 /* We're only interested in usual deallocation functions. */
4591 else
4593 }
4600 }
4602 /* Check the global deallocation functions to see if we want to warn about
4603 defining unsized without sized (or vice versa). */
4605 static void
4607 {
4612 }
4614 /* Earlier we left PTRMEM_CST in variable initializers alone so that we could
4615 look them up when evaluating non-type template parameters. Now we need to
4616 lower them to something the back end can understand. */
4618 static void
4620 {
4623 {
4627 }
4628 }
4630 /* This routine is called at the end of compilation.
4631 Its job is to create all the code needed to initialize and
4632 destroy the global aggregates. We do the destruction
4633 first, since that way we only need to reverse the decls once. */
4635 void
4637 {
4638 tree vars;
4643 tree decl;
4648 /* Bad parse errors. Just forget about it. */
4653 /* This is the point to write out a PCH if we're doing that.
4654 In that case we do not want to do anything else. */
4656 {
4657 /* Mangle all symbols at PCH creation time. */
4665 /* Ensure even the callers don't try to finalize the CU. */
4668 }
4675 /* Handle -fdump-ada-spec[-slim] */
4677 {
4680 else
4684 }
4686 /* FIXME - huh? was input_line -= 1;*/
4688 /* We now have to write out all the stuff we put off writing out.
4689 These include:
4691 o Template specializations that we have not yet instantiated,
4692 but which are needed.
4693 o Initialization and destruction for non-local objects with
4694 static storage duration. (Local objects with static storage
4695 duration are initialized when their scope is first entered,
4696 and are cleaned up via atexit.)
4697 o Virtual function tables.
4699 All of these may cause others to be needed. For example,
4700 instantiating one function may cause another to be needed, and
4701 generating the initializer for an object may cause templates to be
4702 instantiated, etc., etc. */
4706 do
4707 {
4708 tree t;
4709 tree decl;
4713 /* If there are templates that we've put off instantiating, do
4714 them now. */
4718 /* Write out virtual tables as required. Writing out the
4719 virtual table for a template class may cause the
4720 instantiation of members of that class. If we write out
4721 vtables then we remove the class from our list so we don't
4722 have to look at it again. */
4726 {
4729 }
4731 /* Write out needed type info variables. We have to be careful
4732 looping through unemitted decls, because emit_tinfo_decl may
4733 cause other variables to be needed. New elements will be
4734 appended, and we remove from the vector those that actually
4735 get emitted. */
4739 {
4742 }
4744 /* The list of objects with static storage duration is built up
4745 in reverse order. We clear STATIC_AGGREGATES so that any new
4746 aggregates added during the initialization of these will be
4747 initialized in the correct order when we next come around the
4748 loop. */
4752 {
4753 /* We need to start a new initialization function each time
4754 through the loop. That's because we need to know which
4755 vtables have been referenced, and TREE_SYMBOL_REFERENCED
4756 isn't computed until a function is finished, and written
4757 out. That's a deficiency in the back end. When this is
4758 fixed, these initialization functions could all become
4759 inline, with resulting performance improvements. */
4760 tree ssdf_body;
4762 /* Set the line and file, so that it is obviously not from
4763 the source file. */
4767 /* Make sure the back end knows about all the variables. */
4770 /* First generate code to do all the initializations. */
4774 /* Then, generate code to do all the destructions. Do these
4775 in reverse order so that the most recently constructed
4776 variable is the first destroyed. If we're using
4777 __cxa_atexit, then we don't need to do this; functions
4778 were registered at initialization time to destroy the
4779 local statics. */
4781 {
4784 }
4785 else
4788 /* Finish up the static storage duration function for this
4789 round. */
4793 /* All those initializations and finalizations might cause
4794 us to need more inline functions, more template
4795 instantiations, etc. */
4797 ssdf_count++;
4798 /* ??? was: locus_at_end_of_parsing.line++; */
4799 }
4801 /* Now do the same for thread_local variables. */
4804 /* Go through the set of inline functions whose bodies have not
4805 been emitted yet. If out-of-line copies of these functions
4806 are required, emit them. */
4808 {
4809 /* Does it need synthesizing? */
4812 {
4813 /* Even though we're already at the top-level, we push
4814 there again. That way, when we pop back a few lines
4815 hence, all of our state is restored. Otherwise,
4816 finish_function doesn't clean things up, and we end
4817 up with CURRENT_FUNCTION_DECL set. */
4819 /* The decl's location will mark where it was first
4820 needed. Save that so synthesize method can indicate
4821 where it was needed from, in case of error */
4826 }
4836 /* We lie to the back end, pretending that some functions
4837 are not defined when they really are. This keeps these
4838 functions from being put out unnecessarily. But, we must
4839 stop lying when the functions are referenced, or if they
4840 are not comdat since they need to be put out now. If
4841 DECL_INTERFACE_KNOWN, then we have already set
4842 DECL_EXTERNAL appropriately, so there's no need to check
4843 again, and we do not want to clear DECL_EXTERNAL if a
4844 previous call to import_export_decl set it.
4846 This is done in a separate for cycle, because if some
4847 deferred function is contained in another deferred
4848 function later in deferred_fns varray,
4849 rest_of_compilation would skip this function and we
4850 really cannot expand the same function twice. */
4855 {
4861 /* If we mark !DECL_EXTERNAL one of the symbols in some comdat
4862 group, we need to mark all symbols in the same comdat group
4863 that way. */
4871 }
4873 /* If we're going to need to write this function out, and
4874 there's already a body for it, create RTL for it now.
4875 (There might be no body if this is a method we haven't
4876 gotten around to synthesizing yet.) */
4881 {
4882 /* We will output the function; no longer consider it in this
4883 loop. */
4885 /* Generate RTL for this function now that we know we
4886 need it. */
4888 /* If we're compiling -fsyntax-only pretend that this
4889 function has been written out so that we don't try to
4890 expand it again. */
4894 }
4895 }
4900 /* Static data members are just like namespace-scope globals. */
4902 {
4904 /* Don't write it out if we haven't seen a definition. */
4908 /* If this static data member is needed, provide it to the
4909 back end. */
4912 }
4918 retries++;
4919 }
4926 /* All used inline functions must have a definition at this point. */
4928 {
4931 /* If the definition actually was available here, then the
4932 fact that the function was not defined merely represents
4933 that for some reason (use of a template repository,
4934 #pragma interface, etc.) we decided not to emit the
4935 definition here. */
4937 /* Don't complain if the template was defined. */
4941 {
4944 /* Avoid a duplicate warning from check_global_declaration. */
4946 }
4947 }
4949 /* So must decls that use a type with no linkage. */
4955 /* Then, do the Objective-C stuff. This is where all the
4956 Objective-C module stuff gets generated (symtab,
4957 class/protocol/selector lists etc). This must be done after C++
4958 templates, destructors etc. so that selectors used in C++
4959 templates are properly allocated. */
4963 /* We give C linkage to static constructors and destructors. */
4966 /* Generate initialization and destruction functions for all
4967 priorities for which they are required. */
4970 generate_ctor_and_dtor_functions_for_priority,
4973 /* If this is obj-c++ and we need a static init, call
4974 generate_ctor_or_dtor_function. */
4976 DEFAULT_INIT_PRIORITY,
4979 /* We're done with the splay-tree now. */
4983 /* Generate any missing aliases. */
4986 /* We're done with static constructors, so we can go back to "C++"
4987 linkage now. */
4991 {
4995 }
5002 /* The entire file is now complete. If requested, dump everything
5003 to a file. */
5007 {
5010 }
5015 /* Indicate that we're done with front end processing. */
5017 }
5019 /* Perform any post compilation-proper cleanups for the C++ front-end.
5020 This should really go away. No front-end should need to do
5021 anything past the compilation process. */
5023 void
5025 {
5029 {
5030 /* Generate the special constructor initialization function that
5031 calls __VLTRegisterPairs, and give it a very high
5032 initialization priority. This must be done after
5033 finalize_compilation_unit so that we have accurate
5034 information about which vtable will actually be emitted. */
5036 }
5044 }
5046 /* FN is an OFFSET_REF, DOTSTAR_EXPR or MEMBER_REF indicating the
5047 function to call in parse-tree form; it has not yet been
5048 semantically analyzed. ARGS are the arguments to the function.
5049 They have already been semantically analyzed. This may change
5050 ARGS. */
5052 tree
5054 tsubst_flags_t complain)
5055 {
5056 tree orig_fn;
5058 tree expr;
5059 tree object;
5065 {
5074 /* Transform the arguments and add the implicit "this"
5075 parameter. That must be done before the FN is transformed
5076 because we depend on the form of FN. */
5080 {
5084 }
5085 /* Now that the arguments are done, transform FN. */
5087 }
5089 /* A qualified name corresponding to a bound pointer-to-member is
5090 represented as an OFFSET_REF:
5092 struct B { void g(); };
5093 void (B::*p)();
5094 void B::g() { (this->*p)(); } */
5096 {
5100 complain);
5102 }
5106 else
5115 }
5118 void
5120 {
5125 {
5129 {
5132 }
5133 }
5134 }
5136 /* Return true if function DECL can be inlined. This is used to force
5137 instantiation of methods that might be interesting for inlining. */
5138 bool
5140 {
5146 /* When optimizing, we might inline everything when flatten
5147 attribute or heuristics inlining for size or autoinlining
5148 is used. */
5150 }
5152 /* Normally, we can wait until instantiation-time to synthesize DECL.
5153 However, if DECL is a static data member initialized with a constant
5154 or a constexpr function, we need it right now because a reference to
5155 such a data member or a call to such function is not value-dependent.
5156 For a function that uses auto in the return type, we need to instantiate
5157 it to find out its type. For OpenMP user defined reductions, we need
5158 them instantiated for reduction clauses which inline them by hand
5159 directly. */
5161 static void
5163 {
5172 {
5173 /* Instantiating a function will result in garbage collection. We
5174 must treat this situation as if we were within the body of a
5175 function so as to avoid collecting live data only referenced from
5176 the stack (such as overload resolution candidates). */
5181 }
5182 }
5184 /* Mark DECL (either a _DECL or a BASELINK) as "used" in the program.
5185 If DECL is a specialization or implicitly declared class member,
5186 generate the actual definition. Return false if something goes
5187 wrong, true otherwise. */
5189 bool
5191 {
5192 /* If DECL is a BASELINK for a single function, then treat it just
5193 like the DECL for the function. Otherwise, if the BASELINK is
5194 for an overloaded function, we don't know which function was
5195 actually used until after overload resolution. */
5197 {
5202 }
5204 /* Set TREE_USED for the benefit of -Wunused. */
5206 /* And for structured bindings also the underlying decl. */
5216 /* Mark enumeration types as used. */
5226 {
5230 /* We mark a lambda conversion op as deleted if we can't
5231 generate it properly; see maybe_add_lambda_conv_op. */
5234 {
5238 }
5240 }
5246 /* We can only check DECL_ODR_USED on variables or functions with
5247 DECL_LANG_SPECIFIC set, and these are also the only decls that we
5248 might need special handling for. */
5252 {
5257 }
5259 /* We only want to do this processing once. We don't need to keep trying
5260 to instantiate inline templates, because unit-at-a-time will make sure
5261 we get them compiled before functions that want to inline them. */
5265 /* Normally, we can wait until instantiation-time to synthesize DECL.
5266 However, if DECL is a static data member initialized with a constant
5267 or a constexpr function, we need it right now because a reference to
5268 such a data member or a call to such function is not value-dependent.
5269 For a function that uses auto in the return type, we need to instantiate
5270 it to find out its type. For OpenMP user defined reductions, we need
5271 them instantiated for reduction clauses which inline them by hand
5272 directly. */
5278 /* Check this too in case we're within instantiate_non_dependent_expr. */
5287 {
5291 }
5293 /* If we don't need a value, then we don't need to synthesize DECL. */
5301 /* DR 757: A type without linkage shall not be used as the type of a
5302 variable or function with linkage, unless
5303 o the variable or function has extern "C" linkage (7.5 [dcl.link]), or
5304 o the variable or function is not used (3.2 [basic.def.odr]) or is
5305 defined in the same translation unit. */
5312 {
5314 /* There's no way to define a local extern, and adding it to
5315 the vector interferes with GC, so give an error now. */
5317 else
5319 }
5323 /* Remember it, so we can check it was defined. */
5326 /* Is it a synthesized method that needs to be synthesized? */
5330 /* A function defaulted outside the class is synthesized either by
5331 cp_finish_decl or instantiate_decl. */
5334 {
5335 /* Defer virtual destructors so that thunks get the right
5336 linkage. */
5338 {
5341 }
5343 /* Remember the current location for a function we will end up
5344 synthesizing. Then we can inform the user where it was
5345 required in the case of error. */
5348 /* Synthesizing an implicitly defined member function will result in
5349 garbage collection. We must treat this situation as if we were
5350 within the body of a function so as to avoid collecting live data
5351 on the stack (such as overload resolution candidates).
5353 We could just let cp_write_global_declarations handle synthesizing
5354 this function by adding it to deferred_fns, but doing
5355 it at the use site produces better error messages. */
5359 /* If this is a synthesized method we don't need to
5360 do the instantiation test below. */
5361 }
5367 /* If this is a function or variable that is an instance of some
5368 template, we now know that we will need to actually do the
5369 instantiation. We check that DECL is not an explicit
5370 instantiation because that is not checked in instantiate_decl.
5372 We put off instantiating functions in order to improve compile
5373 times. Maintaining a stack of active functions is expensive,
5374 and the inliner knows to instantiate any functions it might
5375 need. Therefore, we always try to defer instantiation. */
5376 {
5381 }
5384 }
5386 bool
5388 {
5390 }
5392 tree
5394 {
5396 }
5398 tree
5400 {
5401 tree fn;
5409 }