| blob | ef7e6de41c30bf3ed764f9ec53c62837517fd3b8 |
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. */
2421 }
2424 {
2425 /* Under -fvisibility-ms-compat, types are visible by default,
2426 even though their contents aren't. */
2433 else
2435 }
2437 {
2438 /* tinfo visibility is based on the type it's for. */
2439 constrain_visibility
2442 /* Give the target a chance to override the visibility associated
2443 with DECL. */
2449 }
2451 /* Template instantiations and specializations get visibility based
2454 {
2457 else
2458 {
2459 /* Set default visibility to whatever the user supplied with
2460 #pragma GCC visibility or a namespace visibility attribute. */
2463 }
2464 }
2465 }
2468 {
2469 /* If the specialization doesn't specify visibility, use the
2470 visibility from the template. */
2478 {
2482 {
2486 else
2487 {
2491 }
2492 }
2495 /* Template argument visibility outweighs #pragma or namespace
2496 visibility, but not an explicit attribute. */
2498 {
2501 {
2502 /* A class template member with explicit visibility
2503 overrides the class visibility, so we need to apply
2504 all the levels of template args directly. */
2507 {
2510 }
2511 }
2513 /* Limit visibility based on its template arguments. */
2515 }
2516 }
2517 }
2523 /* Names in an anonymous namespace get internal linkage.
2524 This might change once we implement export. */
2527 {
2528 /* Propagate anonymity from type to decl. */
2533 }
2535 /* DR 757: A type without linkage shall not be used as the type of a
2536 variable or function with linkage, unless
2537 o the variable or function has extern "C" linkage (7.5 [dcl.link]), or
2538 o the variable or function is not used (3.2 [basic.def.odr]) or is
2539 defined in the same translation unit.
2541 Since non-extern "C" decls need to be defined in the same
2542 translation unit, we can make the type internal. */
2545 /* If visibility changed and DECL already has DECL_RTL, ensure
2546 symbol flags are updated. */
2553 }
2555 /* By default, static data members and function members receive
2556 the visibility of their containing class. */
2558 static void
2560 {
2566 else
2567 {
2568 /* Default to the class visibility. */
2572 }
2574 /* Give the target a chance to override the visibility associated
2575 with DECL. */
2579 /* Construction virtual tables are not exported because
2580 they cannot be referred to from other object files;
2581 their name is not standardized by the ABI. */
2587 }
2589 /* Returns true iff DECL is an inline that should get hidden visibility
2590 because of -fvisibility-inlines-hidden. */
2592 static bool
2594 {
2596 /* Don't do this for inline templates; specializations might not be
2597 inline, and we don't want them to inherit the hidden
2598 visibility. We'll set it here for all inline instantiations. */
2599 && !processing_template_decl
2604 }
2606 /* Constrain the visibility of a class TYPE based on the visibility of its
2607 field types. Warn if any fields require lesser visibility. */
2609 void
2611 {
2612 tree binfo;
2613 tree t;
2622 /* Don't warn about visibility if the class has explicit visibility. */
2629 {
2634 {
2636 {
2639 {
2644 else
2648 }
2649 else
2653 }
2654 }
2661 }
2665 {
2669 {
2671 {
2674 {
2679 else
2683 }
2684 else
2688 }
2689 }
2695 }
2696 }
2698 /* Functions for adjusting the visibility of a tagged type and its nested
2699 types and declarations when it gets a name for linkage purposes from a
2700 typedef. */
2705 /* First reset the visibility of all the types. */
2707 static void
2709 {
2714 }
2715 static void
2717 {
2719 }
2721 /* Then reset the visibility of any static data members or member
2722 functions that use those types. */
2724 static void
2726 {
2735 }
2737 static void
2739 {
2741 {
2743 {
2748 }
2750 {
2756 }
2758 {
2762 }
2765 }
2766 }
2768 static void
2770 {
2772 }
2773 void
2775 {
2778 }
2780 /* Set up our initial idea of what the linkage of DECL should be. */
2782 void
2784 {
2786 /* We've already made a decision as to how this function will
2789 {
2792 {
2796 /* A non-template inline function with external linkage will
2797 always be COMDAT. As we must eventually determine the
2798 linkage of all functions, and as that causes writes to
2799 the data mapped in from the PCH file, it's advantageous
2800 to mark the functions at this point. */
2804 {
2805 /* This function must have external linkage, as
2806 otherwise DECL_INTERFACE_KNOWN would have been
2807 set. */
2811 }
2812 }
2815 }
2816 }
2818 /* DECL is a FUNCTION_DECL or VAR_DECL. If the object file linkage
2819 for DECL has not already been determined, do so now by setting
2820 DECL_EXTERNAL, DECL_COMDAT and other related flags. Until this
2821 function is called entities with vague linkage whose definitions
2822 are available must have TREE_PUBLIC set.
2824 If this function decides to place DECL in COMDAT, it will set
2825 appropriate flags -- but will not clear DECL_EXTERNAL. It is up to
2826 the caller to decide whether or not to clear DECL_EXTERNAL. Some
2827 callers defer that decision until it is clear that DECL is actually
2828 required. */
2830 void
2832 {
2841 /* We cannot determine what linkage to give to an entity with vague
2842 linkage until the end of the file. For example, a virtual table
2843 for a class will be defined if and only if the key method is
2844 defined in this translation unit. As a further example, consider
2845 that when compiling a translation unit that uses PCH file with
2846 "-frepo" it would be incorrect to make decisions about what
2847 entities to emit when building the PCH; those decisions must be
2848 delayed until the repository information has been processed. */
2850 /* Object file linkage for explicit instantiations is handled in
2851 mark_decl_instantiated. For static variables in functions with
2852 vague linkage, maybe_commonize_var is used.
2854 Therefore, the only declarations that should be provided to this
2855 function are those with external linkage that are:
2857 * implicit instantiations of function templates
2859 * inline function
2861 * implicit instantiations of static data members of class
2862 templates
2864 * virtual tables
2866 * typeinfo objects
2868 Furthermore, all entities that reach this point must have a
2869 definition available in this translation unit.
2871 The following assertions check these conditions. */
2873 /* Any code that creates entities with TREE_PUBLIC cleared should
2874 also set DECL_INTERFACE_KNOWN. */
2880 else
2884 /* Check that a definition of DECL is available in this translation
2885 unit. */
2888 /* Assume that DECL will not have COMDAT linkage. */
2890 /* Assume that DECL will not be imported into this translation
2891 unit. */
2894 /* See if the repository tells us whether or not to emit DECL in
2895 this translation unit. */
2900 {
2901 /* The repository indicates that this entity should be defined
2902 here. Make sure the back end honors that request. */
2904 /* Output the definition as an ordinary strong definition. */
2908 }
2911 /* We have already decided what to do with this DECL; there is no
2912 need to check anything further. */
2913 ;
2915 {
2925 /* The ABI requires that all virtual tables be emitted with
2926 COMDAT linkage. However, on systems where COMDAT symbols
2927 don't show up in the table of contents for a static
2928 archive, or on systems without weak symbols (where we
2929 approximate COMDAT linkage by using internal linkage), the
2930 linker will report errors about undefined symbols because
2931 it will not see the virtual table definition. Therefore,
2932 in the case that we know that the virtual table will be
2933 emitted in only one translation unit, we make the virtual
2934 table an ordinary definition with external linkage. */
2937 {
2938 /* CLASS_TYPE is being exported from this translation unit,
2939 so DECL should be defined here. */
2941 /* If a class is declared in a header with the "extern
2942 template" extension, then it will not be instantiated,
2943 even in translation units that would normally require
2944 it. Often such classes are explicitly instantiated in
2945 one translation unit. Therefore, the explicit
2946 instantiation must be made visible to other translation
2947 units. */
2949 else
2950 {
2951 /* The generic C++ ABI says that class data is always
2952 COMDAT, even if there is a key function. Some
2953 variants (e.g., the ARM EABI) says that class data
2954 only has COMDAT linkage if the class data might be
2955 emitted in more than one translation unit. When the
2956 key method can be inline and is inline, we still have
2957 to arrange for comdat even though
2958 class_data_always_comdat is false. */
2962 {
2963 /* The ABI requires COMDAT linkage. Normally, we
2964 only emit COMDAT things when they are needed;
2965 make sure that we realize that this entity is
2966 indeed needed. */
2969 }
2970 }
2971 }
2975 else
2977 }
2979 {
2982 {
2988 /* If -fno-rtti was specified, then we cannot be sure
2989 that RTTI information will be emitted with the
2990 virtual table of the class, so we must emit it
2991 wherever it is used. */
2994 else
2995 {
2998 {
3004 {
3007 }
3008 }
3009 else
3011 }
3012 }
3013 else
3015 }
3017 {
3018 /* DECL is an implicit instantiation of a function or static
3019 data member. */
3022 || (flag_implicit_inline_templates
3026 else
3027 /* If we are not implicitly generating templates, then mark
3028 this entity as undefined in this translation unit. */
3030 }
3032 {
3034 {
3038 {
3042 && ! flag_implement_inlines
3048 /* Always make artificials weak. */
3051 else
3053 }
3054 }
3055 else
3057 }
3058 else
3062 {
3063 /* If we are importing DECL into this translation unit, mark is
3064 an undefined here. */
3067 }
3069 {
3070 /* If we decided to put DECL in COMDAT, mark it accordingly at
3071 this point. */
3073 }
3076 }
3078 /* Return an expression that performs the destruction of DECL, which
3079 must be a VAR_DECL whose type has a non-trivial destructor, or is
3080 an array whose (innermost) elements have a non-trivial destructor. */
3082 tree
3084 {
3088 }
3090 /* Returns the initialization guard variable for the variable DECL,
3091 which has static storage duration. */
3093 tree
3095 {
3096 tree sname;
3097 tree guard;
3102 {
3103 tree guard_type;
3105 /* We use a type that is big enough to contain a mutex as well
3106 as an integer counter. */
3111 /* The guard should have the same linkage as what it guards. */
3129 }
3131 }
3133 /* Return an atomic load of src with the appropriate memory model. */
3135 static tree
3137 {
3152 }
3154 /* Return those bits of the GUARD variable that should be set when the
3155 guarded entity is actually initialized. */
3157 static tree
3159 {
3161 {
3162 /* We only set the first byte of the guard, in order to leave room
3163 for a mutex in the high-order bits. */
3166 guard);
3169 guard);
3171 }
3174 }
3176 /* Return an expression which determines whether or not the GUARD
3177 variable has already been initialized. */
3179 tree
3181 {
3182 tree guard_value;
3186 else
3189 /* Mask off all but the low bit. */
3191 {
3197 tf_warning_or_error);
3198 }
3205 tf_warning_or_error);
3206 }
3208 /* Return an expression which sets the GUARD variable, indicating that
3209 the variable being guarded has been initialized. */
3211 tree
3213 {
3214 tree guard_init;
3216 /* Set the GUARD to one. */
3222 tf_warning_or_error);
3223 }
3225 /* Returns true iff we can tell that VAR does not have a dynamic
3226 initializer. */
3228 static bool
3230 {
3231 /* If it's defined in another TU, we can't tell. */
3234 /* If it has a non-trivial destructor, registering the destructor
3235 counts as dynamic initialization. */
3238 /* If it's in this TU, its initializer has been processed, unless
3239 it's a case of self-initialization, then DECL_INITIALIZED_P is
3240 false while the initializer is handled by finish_id_expression. */
3243 /* If it has no initializer or a constant one, it's not dynamic. */
3246 }
3248 /* Returns true iff VAR is a variable that needs uses to be
3249 wrapped for possible dynamic initialization. */
3251 static bool
3253 {
3259 }
3261 /* Get the FUNCTION_DECL for the shared TLS init function for this
3262 translation unit. */
3264 static tree
3266 {
3270 {
3273 void_list_node));
3279 }
3281 }
3283 /* Get a FUNCTION_DECL for the init function for the thread_local
3284 variable VAR. The init function will be an alias to the function
3285 that initializes all the non-local TLS variables in the translation
3286 unit. The init function is only used by the wrapper function. */
3288 static tree
3290 {
3291 /* Only C++11 TLS vars need this init fn. */
3295 /* If -fno-extern-tls-init, assume that we don't need to call
3296 a tls init function for a variable defined in another TU. */
3300 /* If the variable is internal, or if we can't generate aliases,
3301 call the local init function directly. */
3308 {
3311 void_list_node));
3320 {
3322 /* If the variable is defined somewhere else and might have static
3323 initialization, make the init function a weak reference. */
3329 else
3331 }
3341 }
3343 }
3345 /* Get a FUNCTION_DECL for the init wrapper function for the thread_local
3346 variable VAR. The wrapper function calls the init function (if any) for
3347 VAR and then returns a reference to VAR. The wrapper function is used
3348 in place of VAR everywhere VAR is mentioned. */
3350 tree
3352 {
3353 /* Only C++11 TLS vars need this wrapper fn. */
3360 {
3361 /* A named rvalue reference is an lvalue, so the wrapper should
3362 always return an lvalue reference. */
3371 /* The wrapper is inline and emitted everywhere var is used. */
3374 {
3376 #ifdef HAVE_GAS_HIDDEN
3377 /* Make the wrapper bind locally; there's no reason to share
3378 the wrapper between multiple shared objects. */
3381 #endif
3382 }
3388 #if 0
3389 /* We want CSE to commonize calls to the wrapper, but marking it as
3390 pure is unsafe since it has side-effects. I guess we need a new
3391 ECF flag even weaker than ECF_PURE. FIXME! */
3393 #endif
3398 }
3400 }
3402 /* At EOF, generate the definition for the TLS wrapper function FN:
3404 T& var_wrapper() {
3405 if (init_fn) init_fn();
3406 return var;
3407 } */
3409 static void
3411 {
3416 /* Only call the init fn if there might be one. */
3418 {
3420 /* If init_fn is a weakref, make sure it exists before calling. */
3422 {
3427 tf_warning_or_error);
3429 }
3433 {
3436 }
3437 }
3438 else
3439 /* If there's no initialization, the wrapper is a constant function. */
3444 }
3446 /* Start the process of running a particular set of global constructors
3447 or destructors. Subroutine of do_[cd]tors. Also called from
3448 vtv_start_verification_constructor_init_function. */
3450 static tree
3452 {
3453 tree body;
3454 tree fndecl;
3457 /* Make ctor or dtor function. METHOD_TYPE may be 'I' or 'D'. */
3460 {
3463 #ifdef JOINER
3465 #else
3467 #endif
3470 }
3471 else
3477 NULL_TREE));
3482 /* Mark as artificial because it's not explicitly in the user's
3483 source code. */
3486 /* Mark this declaration as used to avoid spurious warnings. */
3489 /* Mark this function as a global constructor or destructor. */
3492 else
3498 }
3500 /* Finish the process of running a particular set of global constructors
3501 or destructors. Subroutine of do_[cd]tors. */
3503 static void
3505 {
3506 tree fn;
3508 /* Finish up. */
3513 {
3516 }
3517 else
3518 {
3521 }
3524 }
3526 /* The names of the parameters to the function created to handle
3527 initializations and destructions for objects with static storage
3528 duration. */
3532 /* The name of the function we create to handle initializations and
3533 destructions for objects with static storage duration. */
3536 /* The declaration for the __INITIALIZE_P argument. */
3539 /* The declaration for the __PRIORITY argument. */
3542 /* The declaration for the static storage duration function. */
3545 /* All the static storage duration functions created in this
3546 translation unit. */
3549 /* A map from priority levels to information about that priority
3550 level. There may be many such levels, so efficient lookup is
3551 important. */
3554 /* Begins the generation of the function that will handle all
3555 initialization and destruction of objects with static storage
3556 duration. The function generated takes two parameters of type
3557 `int': __INITIALIZE_P and __PRIORITY. If __INITIALIZE_P is
3558 nonzero, it performs initializations. Otherwise, it performs
3559 destructions. It only performs those initializations or
3560 destructions with the indicated __PRIORITY. The generated function
3561 returns no value.
3563 It is assumed that this function will only be called once per
3564 translation unit. */
3566 static tree
3568 {
3569 tree type;
3570 tree body;
3573 /* Create the identifier for this function. It will be of the form
3574 SSDF_IDENTIFIER_<number>. */
3579 NULL_TREE);
3581 /* Create the FUNCTION_DECL itself. */
3584 type);
3588 /* Put this function in the list of functions to be called from the
3589 static constructors and destructors. */
3591 {
3594 /* Take this opportunity to initialize the map from priority
3595 numbers to information about that priority level. */
3598 /*delete_value_fn=*/
3602 /* We always need to generate functions for the
3603 DEFAULT_INIT_PRIORITY so enter it now. That way when we walk
3604 priorities later, we'll be sure to find the
3605 DEFAULT_INIT_PRIORITY. */
3607 }
3611 /* Create the argument list. */
3612 initialize_p_decl = cp_build_parm_decl
3615 priority_decl = cp_build_parm_decl
3622 /* Put the function in the global scope. */
3625 /* Start the function itself. This is equivalent to declaring the
3626 function as:
3628 static void __ssdf (int __initialize_p, init __priority_p);
3630 It is static because we only need to call this function from the
3631 various constructor and destructor functions for this module. */
3634 SF_PRE_PARSED);
3636 /* Set up the scope of the outermost block in the function. */
3640 }
3642 /* Finish the generation of the function which performs initialization
3643 and destruction of objects with static storage duration. After
3644 this point, no more such objects can be created. */
3646 static void
3648 {
3649 /* Close out the function. */
3652 }
3654 /* Return the information about the indicated PRIORITY level. If no
3655 code to handle this level has yet been generated, generate the
3656 appropriate prologue. */
3658 static priority_info
3660 {
3661 priority_info pi;
3662 splay_tree_node n;
3667 {
3668 /* Create a new priority information structure, and insert it
3669 into the map. */
3676 }
3677 else
3681 }
3683 /* The effective initialization priority of a DECL. */
3685 #define DECL_EFFECTIVE_INIT_PRIORITY(decl) \
3686 ((!DECL_HAS_INIT_PRIORITY_P (decl) || DECL_INIT_PRIORITY (decl) == 0) \
3687 ? DEFAULT_INIT_PRIORITY : DECL_INIT_PRIORITY (decl))
3689 /* Whether a DECL needs a guard to protect it against multiple
3690 initialization. */
3692 #define NEEDS_GUARD_P(decl) (TREE_PUBLIC (decl) && (DECL_COMMON (decl) \
3693 || DECL_ONE_ONLY (decl) \
3694 || DECL_WEAK (decl)))
3696 /* Called from one_static_initialization_or_destruction(),
3697 via walk_tree.
3698 Walks the initializer list of a global variable and looks for
3699 temporary variables (DECL_NAME() == NULL and DECL_ARTIFICIAL != 0)
3700 and that have their DECL_CONTEXT() == NULL.
3701 For each such temporary variable, set their DECL_CONTEXT() to
3702 the current function. This is necessary because otherwise
3703 some optimizers (enabled by -O2 -fprofile-arcs) might crash
3704 when trying to refer to a temporary variable that does not have
3705 it's DECL_CONTECT() properly set. */
3706 static tree
3710 {
3714 {
3715 tree var;
3723 }
3726 }
3728 /* Set up to handle the initialization or destruction of DECL. If
3729 INITP is nonzero, we are initializing the variable. Otherwise, we
3730 are destroying it. */
3732 static void
3734 {
3736 tree guard;
3738 /* If we are supposed to destruct and there's a trivial destructor,
3739 nothing has to be done. */
3744 /* Trick the compiler into thinking we are at the file and line
3745 where DECL was declared so that error-messages make sense, and so
3746 that the debugger will show somewhat sensible file and line
3747 information. */
3750 /* Make sure temporary variables in the initialiser all have
3751 their DECL_CONTEXT() set to a value different from NULL_TREE.
3752 This can happen when global variables initializers are built.
3753 In that case, the DECL_CONTEXT() of the global variables _AND_ of all
3754 the temporary variables that might have been generated in the
3755 accompanying initializers is NULL_TREE, meaning the variables have been
3756 declared in the global namespace.
3757 What we want to do here is to fix that and make sure the DECL_CONTEXT()
3758 of the temporaries are set to the current function decl. */
3760 fix_temporary_vars_context_r,
3761 NULL);
3763 /* Because of:
3765 [class.access.spec]
3767 Access control for implicit calls to the constructors,
3768 the conversion functions, or the destructor called to
3769 create and destroy a static data member is performed as
3770 if these calls appeared in the scope of the member's
3771 class.
3773 we pretend we are in a static member function of the class of
3774 which the DECL is a member. */
3776 {
3779 }
3781 /* Assume we don't need a guard. */
3783 /* We need a guard if this is an object with external linkage that
3784 might be initialized in more than one place. (For example, a
3785 static data member of a template, when the data member requires
3786 construction.) */
3788 {
3789 tree guard_cond;
3793 /* When using __cxa_atexit, we just check the GUARD as we would
3794 for a local static. */
3796 {
3797 /* When using __cxa_atexit, we never try to destroy
3798 anything from a static destructor. */
3801 }
3802 /* If we don't have __cxa_atexit, then we will be running
3803 destructors from .fini sections, or their equivalents. So,
3804 we need to know how many times we've tried to initialize this
3805 object. We do initializations only if the GUARD is zero,
3806 i.e., if we are the first to initialize the variable. We do
3807 destructions only if the GUARD is one, i.e., if we are the
3808 last to destroy the variable. */
3810 guard_cond
3812 EQ_EXPR,
3814 guard,
3816 tf_warning_or_error),
3817 integer_one_node,
3818 tf_warning_or_error);
3819 else
3820 guard_cond
3822 EQ_EXPR,
3824 guard,
3826 tf_warning_or_error),
3827 integer_zero_node,
3828 tf_warning_or_error);
3832 }
3835 /* If we're using __cxa_atexit, we have not already set the GUARD,
3836 so we must do so now. */
3840 /* Perform the initialization or destruction. */
3842 {
3844 {
3847 {
3851 }
3852 }
3854 /* If we're using __cxa_atexit, register a function that calls the
3855 destructor for the object. */
3858 }
3859 else
3862 /* Finish the guard if-stmt, if necessary. */
3864 {
3867 }
3869 /* Now that we're done with DECL we don't need to pretend to be a
3870 member of its class any longer. */
3873 }
3875 /* Generate code to do the initialization or destruction of the decls in VARS,
3876 a TREE_LIST of VAR_DECL with static storage duration.
3877 Whether initialization or destruction is performed is specified by INITP. */
3879 static void
3881 {
3884 /* Build the outer if-stmt to check for initialization or destruction. */
3888 EQ_EXPR,
3889 initialize_p_decl,
3890 cond,
3891 tf_warning_or_error);
3894 /* To make sure dynamic construction doesn't access globals from other
3895 compilation units where they might not be yet constructed, for
3896 -fsanitize=address insert __asan_before_dynamic_init call that
3897 prevents access to either all global variables that need construction
3898 in other compilation units, or at least those that haven't been
3899 initialized yet. Variables that need dynamic construction in
3900 the current compilation unit are kept accessible. */
3907 tree priority_if_stmt;
3909 priority_info pi;
3911 /* If we don't need a destructor, there's nothing to do. Avoid
3912 creating a possibly empty if-stmt. */
3914 {
3917 }
3919 /* Remember that we had an initialization or finalization at this
3920 priority. */
3925 else
3928 /* Conditionalize this initialization on being in the right priority
3929 and being initializing/finalizing appropriately. */
3932 EQ_EXPR,
3933 priority_decl,
3935 tf_warning_or_error);
3938 /* Process initializers with same priority. */
3942 /* Do one initialization or destruction. */
3946 /* Finish up the priority if-stmt body. */
3952 /* Revert what __asan_before_dynamic_init did by calling
3953 __asan_after_dynamic_init. */
3957 /* Finish up the init/destruct if-stmt body. */
3960 }
3962 /* VARS is a list of variables with static storage duration which may
3963 need initialization and/or finalization. Remove those variables
3964 that don't really need to be initialized or finalized, and return
3965 the resulting list. The order in which the variables appear in
3966 VARS is in reverse order of the order in which they should actually
3967 be initialized. The list we return is in the unreversed order;
3968 i.e., the first variable should be initialized first. */
3970 static tree
3972 {
3977 {
3982 /* Deal gracefully with error. */
3984 {
3987 }
3989 /* The only things that can be initialized are variables. */
3992 /* If this object is not defined, we don't need to do anything
3993 here. */
3995 {
3998 }
4000 /* Also, if the initializer already contains errors, we can bail
4001 out now. */
4004 {
4007 }
4009 /* This variable is going to need initialization and/or
4010 finalization, so we add it to the list. */
4014 }
4017 }
4019 /* Make sure we have told the back end about all the variables in
4020 VARS. */
4022 static void
4024 {
4025 tree v;
4028 {
4031 {
4034 }
4035 }
4036 }
4038 /* Generate a static constructor (if CONSTRUCTOR_P) or destructor
4039 (otherwise) that will initialize all global objects with static
4040 storage duration having the indicated PRIORITY. */
4042 static void
4045 {
4047 tree fndecl;
4048 tree body;
4052 /* ??? */
4053 /* Was: locus->line++; */
4055 /* We use `I' to indicate initialization and `D' to indicate
4056 destruction. */
4059 /* We emit the function lazily, to avoid generating empty
4060 global constructors and destructors. */
4063 /* For Objective-C++, we may need to initialize metadata found in this module.
4064 This must be done _before_ any other static initializations. */
4067 {
4070 }
4072 /* Call the static storage duration function with appropriate
4073 arguments. */
4075 {
4076 /* Calls to pure or const functions will expand to nothing. */
4078 {
4079 tree call;
4086 constructor_p),
4088 priority),
4089 NULL_TREE);
4091 }
4092 }
4094 /* Close out the function. */
4097 }
4099 /* Generate constructor and destructor functions for the priority
4100 indicated by N. */
4102 static int
4104 {
4109 /* Generate the functions themselves, but only if they are really
4110 needed. */
4116 /* Keep iterating. */
4118 }
4120 /* Return C++ property of T, based on given operation OP. */
4122 static int
4124 {
4126 {
4128 {
4136 }
4153 }
4154 }
4156 /* Collect source file references recursively, starting from NAMESPC. */
4158 static void
4160 {
4161 /* Iterate over names in this name space. */
4164 ;
4167 else
4169 }
4171 /* Collect decls relevant to SOURCE_FILE from all namespaces recursively,
4172 starting from NAMESPC. */
4174 static void
4176 {
4179 /* Collect decls from this namespace. This will skip
4180 NAMESPACE_DECLs (both aliases and regular, it cannot tell). */
4183 /* Now scan for namespace children, and dump them. */
4187 }
4189 /* Returns true iff there is a definition available for variable or
4190 function DECL. */
4192 bool
4194 {
4197 /* A pending instantiation of a friend temploid is defined. */
4201 else
4202 {
4205 }
4206 }
4208 /* Nonzero for a VAR_DECL whose value can be used in a constant expression.
4210 [expr.const]
4212 An integral constant-expression can only involve ... const
4213 variables of integral or enumeration types initialized with
4214 constant expressions ...
4216 C++0x also allows constexpr variables and temporaries initialized
4217 with constant expressions. We handle the former here, but the latter
4218 are just folded away in cxx_eval_constant_expression.
4220 The standard does not require that the expression be non-volatile.
4221 G++ implements the proposed correction in DR 457. */
4223 bool
4225 {
4229 /* We don't know if a template static data member is initialized with
4230 a constant expression until we instantiate its initializer. Even
4231 in the case of a constexpr variable, we can't treat it as a
4232 constant until its initializer is complete in case it's used in
4233 its own initializer. */
4236 }
4238 /* Returns true if DECL could be a symbolic constant variable, depending on
4239 its initializer. */
4241 bool
4243 {
4250 /* A proxy isn't constant. */
4257 else
4262 /* We know the initializer, and it isn't constant. */
4264 else
4266 }
4268 /* Complain that DECL uses a type with no linkage. In C++98 mode this is
4269 called from grokfndecl and grokvardecl; in all modes it is called from
4270 cp_write_global_declarations. */
4272 void
4274 {
4276 /* In C++11 it's ok if the decl is defined. */
4280 /* The type that got us on no_linkage_decls must have gotten a name for
4283 /* The type might end up having a typedef name for linkage purposes. */
4286 {
4294 /* DRs 132, 319 and 389 seem to indicate types with
4295 no linkage can only be used to declare extern "C"
4296 entities. Since it's not always an error in the
4297 ISO C++ 90 Standard, we only issue a warning. */
4299 "with no linkage used to declare variable %q#D with "
4301 else
4304 decl);
4309 }
4311 {
4314 "%q#D, declared using local type "
4316 }
4320 else
4323 }
4325 /* Collect declarations from all namespaces relevant to SOURCE_FILE. */
4327 static void
4329 {
4331 }
4333 /* Clear DECL_EXTERNAL for NODE. */
4335 static bool
4337 {
4340 }
4342 /* Build up the function to run dynamic initializers for thread_local
4343 variables in this translation unit and alias the init functions for the
4344 individual variables to it. */
4346 static void
4348 {
4358 boolean_type_node);
4373 tf_warning_or_error);
4376 boolean_true_node,
4377 tf_warning_or_error));
4379 {
4384 /* Output init aliases even with -fno-extern-tls-init. */
4386 {
4390 cgraph_node *alias
4394 }
4395 }
4401 }
4403 /* We're at the end of compilation, so generate any mangling aliases that
4404 we've been saving up, if DECL is going to be output and ID2 isn't
4405 already taken by another declaration. */
4407 static void
4409 {
4413 {
4416 /* Don't create an alias to an unreferenced function. */
4418 }
4420 tree *slot
4422 INSERT);
4424 /* If there's a declaration already using this mangled name,
4425 don't create a compatibility alias that conflicts. */
4440 else
4442 }
4444 /* Note that we might want to emit an alias with the symbol ID2 for DECL at
4445 the end of translation, for compatibility across bugs in the mangling
4446 implementation. */
4448 void
4450 {
4452 {
4455 else
4456 {
4459 }
4460 }
4461 }
4463 /* Emit all mangling aliases that were deferred up to this point. */
4465 void
4467 {
4469 {
4473 }
4475 }
4477 /* Record a mangling of DECL, whose DECL_ASSEMBLER_NAME has just been
4478 set. NEED_WARNING is true if we must warn about collisions. We do
4479 this to spot changes in mangling that may require compatibility
4480 aliases. */
4482 void
4484 {
4490 tree *slot
4492 INSERT);
4494 /* If this is already an alias, remove the alias, because the real
4495 decl takes precedence. */
4499 {
4502 }
4507 {
4514 "a later -fabi-version= (or =0)"
4517 }
4518 }
4520 /* The mangled name of DECL is being forcibly changed to NAME. Remove
4521 any existing knowledge of DECL's mangled name meaning DECL. */
4523 void
4525 {
4532 NO_INSERT))
4534 {
4537 /* If this is an alias, remove it from the symbol table. */
4542 }
4545 }
4547 /* The entire file is now complete. If requested, dump everything
4548 to a file. */
4550 static void
4552 {
4553 dump_flags_t flags;
4555 {
4558 }
4559 }
4563 /* Check the deallocation functions for CODE to see if we want to warn that
4564 only one was defined. */
4566 static void
4568 {
4574 {
4576 /* We're only interested in usual deallocation functions. */
4581 else
4583 }
4590 }
4592 /* Check the global deallocation functions to see if we want to warn about
4593 defining unsized without sized (or vice versa). */
4595 static void
4597 {
4602 }
4604 /* Earlier we left PTRMEM_CST in variable initializers alone so that we could
4605 look them up when evaluating non-type template parameters. Now we need to
4606 lower them to something the back end can understand. */
4608 static void
4610 {
4613 {
4617 }
4618 }
4620 /* This routine is called at the end of compilation.
4621 Its job is to create all the code needed to initialize and
4622 destroy the global aggregates. We do the destruction
4623 first, since that way we only need to reverse the decls once. */
4625 void
4627 {
4628 tree vars;
4633 tree decl;
4638 /* Bad parse errors. Just forget about it. */
4643 /* This is the point to write out a PCH if we're doing that.
4644 In that case we do not want to do anything else. */
4646 {
4647 /* Mangle all symbols at PCH creation time. */
4655 /* Ensure even the callers don't try to finalize the CU. */
4658 }
4665 /* Handle -fdump-ada-spec[-slim] */
4667 {
4670 else
4674 }
4676 /* FIXME - huh? was input_line -= 1;*/
4678 /* We now have to write out all the stuff we put off writing out.
4679 These include:
4681 o Template specializations that we have not yet instantiated,
4682 but which are needed.
4683 o Initialization and destruction for non-local objects with
4684 static storage duration. (Local objects with static storage
4685 duration are initialized when their scope is first entered,
4686 and are cleaned up via atexit.)
4687 o Virtual function tables.
4689 All of these may cause others to be needed. For example,
4690 instantiating one function may cause another to be needed, and
4691 generating the initializer for an object may cause templates to be
4692 instantiated, etc., etc. */
4696 do
4697 {
4698 tree t;
4699 tree decl;
4703 /* If there are templates that we've put off instantiating, do
4704 them now. */
4708 /* Write out virtual tables as required. Writing out the
4709 virtual table for a template class may cause the
4710 instantiation of members of that class. If we write out
4711 vtables then we remove the class from our list so we don't
4712 have to look at it again. */
4716 {
4719 }
4721 /* Write out needed type info variables. We have to be careful
4722 looping through unemitted decls, because emit_tinfo_decl may
4723 cause other variables to be needed. New elements will be
4724 appended, and we remove from the vector those that actually
4725 get emitted. */
4729 {
4732 }
4734 /* The list of objects with static storage duration is built up
4735 in reverse order. We clear STATIC_AGGREGATES so that any new
4736 aggregates added during the initialization of these will be
4737 initialized in the correct order when we next come around the
4738 loop. */
4742 {
4743 /* We need to start a new initialization function each time
4744 through the loop. That's because we need to know which
4745 vtables have been referenced, and TREE_SYMBOL_REFERENCED
4746 isn't computed until a function is finished, and written
4747 out. That's a deficiency in the back end. When this is
4748 fixed, these initialization functions could all become
4749 inline, with resulting performance improvements. */
4750 tree ssdf_body;
4752 /* Set the line and file, so that it is obviously not from
4753 the source file. */
4757 /* Make sure the back end knows about all the variables. */
4760 /* First generate code to do all the initializations. */
4764 /* Then, generate code to do all the destructions. Do these
4765 in reverse order so that the most recently constructed
4766 variable is the first destroyed. If we're using
4767 __cxa_atexit, then we don't need to do this; functions
4768 were registered at initialization time to destroy the
4769 local statics. */
4771 {
4774 }
4775 else
4778 /* Finish up the static storage duration function for this
4779 round. */
4783 /* All those initializations and finalizations might cause
4784 us to need more inline functions, more template
4785 instantiations, etc. */
4787 ssdf_count++;
4788 /* ??? was: locus_at_end_of_parsing.line++; */
4789 }
4791 /* Now do the same for thread_local variables. */
4794 /* Go through the set of inline functions whose bodies have not
4795 been emitted yet. If out-of-line copies of these functions
4796 are required, emit them. */
4798 {
4799 /* Does it need synthesizing? */
4802 {
4803 /* Even though we're already at the top-level, we push
4804 there again. That way, when we pop back a few lines
4805 hence, all of our state is restored. Otherwise,
4806 finish_function doesn't clean things up, and we end
4807 up with CURRENT_FUNCTION_DECL set. */
4809 /* The decl's location will mark where it was first
4810 needed. Save that so synthesize method can indicate
4811 where it was needed from, in case of error */
4816 }
4826 /* We lie to the back end, pretending that some functions
4827 are not defined when they really are. This keeps these
4828 functions from being put out unnecessarily. But, we must
4829 stop lying when the functions are referenced, or if they
4830 are not comdat since they need to be put out now. If
4831 DECL_INTERFACE_KNOWN, then we have already set
4832 DECL_EXTERNAL appropriately, so there's no need to check
4833 again, and we do not want to clear DECL_EXTERNAL if a
4834 previous call to import_export_decl set it.
4836 This is done in a separate for cycle, because if some
4837 deferred function is contained in another deferred
4838 function later in deferred_fns varray,
4839 rest_of_compilation would skip this function and we
4840 really cannot expand the same function twice. */
4845 {
4851 /* If we mark !DECL_EXTERNAL one of the symbols in some comdat
4852 group, we need to mark all symbols in the same comdat group
4853 that way. */
4861 }
4863 /* If we're going to need to write this function out, and
4864 there's already a body for it, create RTL for it now.
4865 (There might be no body if this is a method we haven't
4866 gotten around to synthesizing yet.) */
4871 {
4872 /* We will output the function; no longer consider it in this
4873 loop. */
4875 /* Generate RTL for this function now that we know we
4876 need it. */
4878 /* If we're compiling -fsyntax-only pretend that this
4879 function has been written out so that we don't try to
4880 expand it again. */
4884 }
4885 }
4890 /* Static data members are just like namespace-scope globals. */
4892 {
4894 /* Don't write it out if we haven't seen a definition. */
4898 /* If this static data member is needed, provide it to the
4899 back end. */
4902 }
4908 retries++;
4909 }
4916 /* All used inline functions must have a definition at this point. */
4918 {
4921 /* If the definition actually was available here, then the
4922 fact that the function was not defined merely represents
4923 that for some reason (use of a template repository,
4924 #pragma interface, etc.) we decided not to emit the
4925 definition here. */
4927 /* Don't complain if the template was defined. */
4931 {
4934 /* Avoid a duplicate warning from check_global_declaration. */
4936 }
4937 }
4939 /* So must decls that use a type with no linkage. */
4945 /* Then, do the Objective-C stuff. This is where all the
4946 Objective-C module stuff gets generated (symtab,
4947 class/protocol/selector lists etc). This must be done after C++
4948 templates, destructors etc. so that selectors used in C++
4949 templates are properly allocated. */
4953 /* We give C linkage to static constructors and destructors. */
4956 /* Generate initialization and destruction functions for all
4957 priorities for which they are required. */
4960 generate_ctor_and_dtor_functions_for_priority,
4963 /* If this is obj-c++ and we need a static init, call
4964 generate_ctor_or_dtor_function. */
4966 DEFAULT_INIT_PRIORITY,
4969 /* We're done with the splay-tree now. */
4973 /* Generate any missing aliases. */
4976 /* We're done with static constructors, so we can go back to "C++"
4977 linkage now. */
4981 {
4985 }
4992 /* The entire file is now complete. If requested, dump everything
4993 to a file. */
4997 {
5000 }
5005 /* Indicate that we're done with front end processing. */
5007 }
5009 /* Perform any post compilation-proper cleanups for the C++ front-end.
5010 This should really go away. No front-end should need to do
5011 anything past the compilation process. */
5013 void
5015 {
5019 {
5020 /* Generate the special constructor initialization function that
5021 calls __VLTRegisterPairs, and give it a very high
5022 initialization priority. This must be done after
5023 finalize_compilation_unit so that we have accurate
5024 information about which vtable will actually be emitted. */
5026 }
5034 }
5036 /* FN is an OFFSET_REF, DOTSTAR_EXPR or MEMBER_REF indicating the
5037 function to call in parse-tree form; it has not yet been
5038 semantically analyzed. ARGS are the arguments to the function.
5039 They have already been semantically analyzed. This may change
5040 ARGS. */
5042 tree
5044 tsubst_flags_t complain)
5045 {
5046 tree orig_fn;
5048 tree expr;
5049 tree object;
5055 {
5064 /* Transform the arguments and add the implicit "this"
5065 parameter. That must be done before the FN is transformed
5066 because we depend on the form of FN. */
5070 {
5074 }
5075 /* Now that the arguments are done, transform FN. */
5077 }
5079 /* A qualified name corresponding to a bound pointer-to-member is
5080 represented as an OFFSET_REF:
5082 struct B { void g(); };
5083 void (B::*p)();
5084 void B::g() { (this->*p)(); } */
5086 {
5090 complain);
5092 }
5096 else
5105 }
5108 void
5110 {
5115 {
5119 {
5122 }
5123 }
5124 }
5126 /* Return true if function DECL can be inlined. This is used to force
5127 instantiation of methods that might be interesting for inlining. */
5128 bool
5130 {
5136 /* When optimizing, we might inline everything when flatten
5137 attribute or heuristics inlining for size or autoinlining
5138 is used. */
5140 }
5142 /* Normally, we can wait until instantiation-time to synthesize DECL.
5143 However, if DECL is a static data member initialized with a constant
5144 or a constexpr function, we need it right now because a reference to
5145 such a data member or a call to such function is not value-dependent.
5146 For a function that uses auto in the return type, we need to instantiate
5147 it to find out its type. For OpenMP user defined reductions, we need
5148 them instantiated for reduction clauses which inline them by hand
5149 directly. */
5151 static void
5153 {
5162 {
5163 /* Instantiating a function will result in garbage collection. We
5164 must treat this situation as if we were within the body of a
5165 function so as to avoid collecting live data only referenced from
5166 the stack (such as overload resolution candidates). */
5171 }
5172 }
5174 /* Mark DECL (either a _DECL or a BASELINK) as "used" in the program.
5175 If DECL is a specialization or implicitly declared class member,
5176 generate the actual definition. Return false if something goes
5177 wrong, true otherwise. */
5179 bool
5181 {
5182 /* If DECL is a BASELINK for a single function, then treat it just
5183 like the DECL for the function. Otherwise, if the BASELINK is
5184 for an overloaded function, we don't know which function was
5185 actually used until after overload resolution. */
5187 {
5192 }
5194 /* Set TREE_USED for the benefit of -Wunused. */
5196 /* And for structured bindings also the underlying decl. */
5206 /* Mark enumeration types as used. */
5216 {
5220 /* We mark a lambda conversion op as deleted if we can't
5221 generate it properly; see maybe_add_lambda_conv_op. */
5224 {
5228 }
5230 }
5236 /* We can only check DECL_ODR_USED on variables or functions with
5237 DECL_LANG_SPECIFIC set, and these are also the only decls that we
5238 might need special handling for. */
5242 {
5247 }
5249 /* We only want to do this processing once. We don't need to keep trying
5250 to instantiate inline templates, because unit-at-a-time will make sure
5251 we get them compiled before functions that want to inline them. */
5255 /* Normally, we can wait until instantiation-time to synthesize DECL.
5256 However, if DECL is a static data member initialized with a constant
5257 or a constexpr function, we need it right now because a reference to
5258 such a data member or a call to such function is not value-dependent.
5259 For a function that uses auto in the return type, we need to instantiate
5260 it to find out its type. For OpenMP user defined reductions, we need
5261 them instantiated for reduction clauses which inline them by hand
5262 directly. */
5268 /* Check this too in case we're within instantiate_non_dependent_expr. */
5277 {
5281 }
5283 /* If we don't need a value, then we don't need to synthesize DECL. */
5291 /* DR 757: A type without linkage shall not be used as the type of a
5292 variable or function with linkage, unless
5293 o the variable or function has extern "C" linkage (7.5 [dcl.link]), or
5294 o the variable or function is not used (3.2 [basic.def.odr]) or is
5295 defined in the same translation unit. */
5302 {
5304 /* There's no way to define a local extern, and adding it to
5305 the vector interferes with GC, so give an error now. */
5307 else
5309 }
5313 /* Remember it, so we can check it was defined. */
5316 /* Is it a synthesized method that needs to be synthesized? */
5320 /* A function defaulted outside the class is synthesized either by
5321 cp_finish_decl or instantiate_decl. */
5324 {
5325 /* Defer virtual destructors so that thunks get the right
5326 linkage. */
5328 {
5331 }
5333 /* Remember the current location for a function we will end up
5334 synthesizing. Then we can inform the user where it was
5335 required in the case of error. */
5338 /* Synthesizing an implicitly defined member function will result in
5339 garbage collection. We must treat this situation as if we were
5340 within the body of a function so as to avoid collecting live data
5341 on the stack (such as overload resolution candidates).
5343 We could just let cp_write_global_declarations handle synthesizing
5344 this function by adding it to deferred_fns, but doing
5345 it at the use site produces better error messages. */
5349 /* If this is a synthesized method we don't need to
5350 do the instantiation test below. */
5351 }
5357 /* If this is a function or variable that is an instance of some
5358 template, we now know that we will need to actually do the
5359 instantiation. We check that DECL is not an explicit
5360 instantiation because that is not checked in instantiate_decl.
5362 We put off instantiating functions in order to improve compile
5363 times. Maintaining a stack of active functions is expensive,
5364 and the inliner knows to instantiate any functions it might
5365 need. Therefore, we always try to defer instantiation. */
5366 {
5371 }
5374 }
5376 bool
5378 {
5380 }
5382 tree
5384 {
5386 }
5388 tree
5390 {
5391 tree fn;
5399 }