| blob | a4a5ebf58ea12426580ee37970e7b0f605bb0dfc |
1 /* Process declarations and variables for C++ compiler.
2 Copyright (C) 1988-2015 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. */
76 /* This structure contains information about the initializations
77 and/or destructions required for a particular priority level. */
79 /* Nonzero if there have been any initializations at this priority
80 throughout the translation unit. */
82 /* Nonzero if there have been any destructions at this priority
83 throughout the translation unit. */
108 /* A list of static class variables. This is needed, because a
109 static class variable can be declared inside the class without
110 an initializer, and then initialized, statically, outside the class. */
113 /* A list of functions which were declared inline, but which we
114 may need to emit outline anyway. */
117 /* A list of decls that use types with no linkage, which we need to make
118 sure are defined. */
121 /* Nonzero if we're done parsing and into end-of-file activities. */
124 \f
126 /* Return a member function type (a METHOD_TYPE), given FNTYPE (a
127 FUNCTION_TYPE), CTYPE (class type), and QUALS (the cv-qualifiers
128 that apply to the function). */
130 tree
132 cp_ref_qualifier rqual)
133 {
134 tree raises;
135 tree attrs;
164 }
166 /* Return a variant of FNTYPE, a FUNCTION_TYPE or METHOD_TYPE, with its
167 return type changed to NEW_RET. */
169 tree
171 {
172 tree newtype;
185 {
190 }
191 else
192 newtype = build_method_type_directly
202 }
204 /* Build a PARM_DECL with NAME and TYPE, and set DECL_ARG_TYPE
205 appropriately. */
207 tree
209 {
212 /* DECL_ARG_TYPE is only used by the back end and the back end never
213 sees templates. */
218 }
220 /* Returns a PARM_DECL for a parameter of the indicated TYPE, with the
221 indicated NAME. */
223 tree
225 {
228 /* All our artificial parms are implicitly `const'; they cannot be
229 assigned to. */
232 }
234 /* Constructors for types with virtual baseclasses need an "in-charge" flag
235 saying whether this constructor is responsible for initialization of
236 virtual baseclasses or not. All destructors also need this "in-charge"
237 flag, which additionally determines whether or not the destructor should
238 free the memory for the object.
240 This function adds the "in-charge" flag to member function FN if
241 appropriate. It is called from grokclassfn and tsubst.
242 FN must be either a constructor or destructor.
244 The in-charge flag follows the 'this' parameter, and is followed by the
245 VTT parm (if any), then the user-written parms. */
247 void
249 {
252 /* If we've already add the in-charge parameter don't do it again. */
256 /* When processing templates we can't know, in general, whether or
257 not we're going to have virtual baseclasses. */
261 /* We don't need an in-charge parameter for constructors that don't
262 have virtual bases. */
273 /* If this is a subobject constructor or destructor, our caller will
274 pass us a pointer to our VTT. */
276 {
279 /* First add it to DECL_ARGUMENTS between 'this' and the real args... */
283 /* ...and then to TYPE_ARG_TYPES. */
287 }
289 /* Then add the in-charge parm (before the VTT parm). */
295 /* Insert our new parameter(s) into the list. */
298 /* And rebuild the function type. */
300 arg_types);
305 fntype = (cp_build_type_attribute_variant
309 /* Now we've got the in-charge parameter. */
311 }
313 /* Classes overload their constituent function names automatically.
314 When a function name is declared in a record structure,
315 its name is changed to it overloaded name. Since names for
316 constructors and destructors can conflict, we place a leading
317 '$' for destructors.
319 CNAME is the name of the class we are grokking for.
321 FUNCTION is a FUNCTION_DECL. It was created by `grokdeclarator'.
323 FLAGS contains bits saying what's special about today's
324 arguments. DTOR_FLAG == DESTRUCTOR.
326 If FUNCTION is a destructor, then we must add the `auto-delete' field
327 as a second parameter. There is some hair associated with the fact
328 that we must "declare" this variable in the manner consistent with the
329 way the rest of the arguments were declared.
331 QUALS are the qualifiers for the this pointer. */
333 void
335 {
338 /* Even within an `extern "C"' block, members get C++ linkage. See
339 [dcl.link] for details. */
343 {
347 }
356 }
358 /* Create an ARRAY_REF, checking for the user doing things backwards
359 along the way. DECLTYPE_P is for N3276, as in the parser. */
361 tree
364 {
365 tree type;
366 tree expr;
374 {
381 }
387 /* If they have an `operator[]', use that. */
389 {
395 }
396 else
397 {
400 /* Otherwise, create an ARRAY_REF for a pointer or array type.
401 It is a little-known fact that, if `a' is an array and `i' is
402 an int, you can write `i[a]', which means the same thing as
403 `a[i]'. */
406 else
411 else
426 else
427 {
431 }
437 }
442 }
444 /* Given the cast expression EXP, checking out its validity. Either return
445 an error_mark_node if there was an unavoidable error, return a cast to
446 void for trying to delete a pointer w/ the value 0, or return the
447 call to delete. If DOING_VEC is true, we handle things differently
448 for doing an array delete.
449 Implements ARM $5.3.4. This is called from the parser. */
451 tree
453 tsubst_flags_t complain)
454 {
461 {
467 }
469 /* An array can't have been allocated by new, so complain. */
476 {
480 }
484 /* As of Valley Forge, you can delete a pointer to const. */
486 /* You can't delete functions. */
488 {
492 }
494 /* Deleting ptr to void is undefined behavior [expr.delete/3]. */
496 {
499 }
501 /* Deleting a pointer with the value zero is valid and has no effect. */
507 sfk_deleting_destructor,
509 else
512 complain);
513 }
515 /* Report an error if the indicated template declaration is not the
516 sort of thing that should be a member template. */
518 void
520 {
521 tree decl;
530 {
531 /* The parser rejects template declarations in local classes
532 (with the exception of generic lambdas). */
534 /* The parser rejects any use of virtual in a function template. */
538 /* The debug-information generating code doesn't know what to do
539 with member templates. */
541 }
544 else
546 }
548 /* Return true iff TYPE is a valid Java parameter or return type. */
550 static bool
552 {
559 {
562 {
571 {
577 }
579 }
580 }
582 }
584 /* For a METHOD in a Java class CTYPE, return true if
585 the parameter and return types are valid Java types.
586 Otherwise, print appropriate error messages, and return false. */
588 bool
590 {
596 {
600 }
609 {
612 {
617 }
618 }
620 }
622 /* Sanity check: report error if this function FUNCTION is not
623 really a member of the class (CTYPE) it is supposed to belong to.
624 TEMPLATE_PARMS is used to specify the template parameters of a member
625 template passed as FUNCTION_DECL. If the member template is passed as a
626 TEMPLATE_DECL, it can be NULL since the parameters can be extracted
627 from the declaration. If the function is not a function template, it
628 must be NULL.
629 It returns the original declaration for the function, NULL_TREE if
630 no declaration was found, error_mark_node if an error was emitted. */
632 tree
634 {
637 tree pushed_scope;
643 /* Since this is a specialization of a member template,
644 we're not going to find the declaration in the class.
645 For example, in:
647 struct S { template <typename T> void f(T); };
648 template <> void S::f(int);
650 we're not going to find `S::f(int)', but there's no
651 reason we should, either. We let our callers know we didn't
652 find the method, but we don't complain. */
655 /* Basic sanity check: for a template function, the template parameters
656 either were not passed, or they are the same of DECL_TEMPLATE_PARMS. */
658 {
662 {
666 }
668 }
670 /* OK, is this a definition of a member template? */
673 /* [temp.mem]
675 A destructor shall not be a member template. */
677 {
680 }
682 /* We must enter the scope here, because conversion operators are
683 named by target type, and type equivalence relies on typenames
684 resolving within the scope of CTYPE. */
688 {
696 {
703 /* We cannot simply call decls_match because this doesn't
704 work for static member functions that are pretending to
705 be methods, and because the name may have been changed by
706 asm("new_name"). */
708 /* Get rid of the this parameter on functions that become
709 static. */
714 /* A member template definition only matches a member template
715 declaration. */
719 /* ref-qualifier or absence of same must match. */
724 /* While finding a match, same types and params are not enough
725 if the function is versioned. Also check version ("target")
726 attributes. */
731 && (!is_template
740 }
742 {
746 }
757 {
762 {
764 {
767 {
770 }
771 }
772 else
774 }
779 else
782 }
783 }
786 else
793 }
795 /* DECL is a function with vague linkage. Remember it so that at the
796 end of the translation unit we can decide whether or not to emit
797 it. */
799 void
801 {
804 }
806 /* As above, but for variable template instantiations. */
808 void
810 {
812 }
814 /* We have just processed the DECL, which is a static data member.
815 The other parameters are as for cp_finish_decl. */
817 void
820 tree asmspec_tree,
822 {
825 /* We cannot call pushdecl here, because that would fill in the
826 TREE_CHAIN of our decl. Instead, we modify cp_finish_decl to do
827 the right thing, namely, to put this decl out straight away. */
833 /* We already complained about the template definition. */
837 else
841 {
847 }
856 }
858 /* DECLARATOR and DECLSPECS correspond to a class member. The other
859 parameters are as for cp_finish_decl. Return the DECL for the
860 class member declared. */
862 tree
866 tree asmspec_tree,
867 tree attrlist)
868 {
869 tree value;
872 tree name;
882 /* friend or constructor went bad. */
888 {
891 }
893 /* Pass friendly classes back. */
901 {
903 {
906 }
911 value);
912 }
914 /* Stash away type declarations. */
916 {
921 {
924 /* If this is a typedef that names the class for linkage purposes
925 (7.1.3p8), apply any attributes directly to the type. */
931 }
938 /* It's important that push_template_decl below follows
939 set_underlying_type above so that the created template
940 carries the properly set type of VALUE. */
946 }
951 {
954 }
960 {
962 {
964 {
968 }
970 {
972 {
976 }
977 }
981 {
986 else
988 value);
989 }
990 else
991 {
995 value);
996 else
998 value);
999 }
1000 }
1005 }
1007 /* Pass friend decls back. */
1013 /* Need to set this before push_template_decl. */
1018 {
1022 }
1029 else
1033 {
1058 /* Pass friends back this way. */
1067 }
1069 }
1071 /* Like `grokfield', but for bitfields.
1072 WIDTH is non-NULL for bit fields only, and is an INTEGER_CST node. */
1074 tree
1077 tree attrlist)
1078 {
1086 /* Pass friendly classes back. */
1093 {
1096 }
1099 {
1102 }
1104 /* Usually, finish_struct_1 catches bitfields with invalid types.
1105 But, in the case of bitfields with function type, we confuse
1106 ourselves into thinking they are member functions, so we must
1107 check here. */
1109 {
1113 }
1116 {
1120 }
1123 {
1126 }
1130 {
1131 /* The width must be an integer type. */
1138 }
1146 }
1148 \f
1149 /* Returns true iff ATTR is an attribute which needs to be applied at
1150 instantiation time rather than template definition time. */
1152 static bool
1154 {
1158 tree arg;
1161 /* Unknown attribute. */
1164 /* Attribute weak handling wants to write out assembly right away. */
1168 /* Attribute unused is applied directly, as it appertains to
1169 decls. */
1173 /* #pragma omp declare simd attribute needs to be always deferred. */
1178 /* If any of the arguments are dependent expressions, we can't evaluate
1179 the attribute until instantiation time. */
1181 {
1184 /* If the first attribute argument is an identifier, only consider
1185 second and following arguments. Attributes like mode, format,
1186 cleanup and several target specific attributes aren't late
1187 just because they have an IDENTIFIER_NODE as first argument. */
1194 }
1199 {
1202 /* We can't apply any attributes to a completely unknown type until
1203 instantiation time. */
1209 /* Also defer most attributes on dependent types. This is not
1210 necessary in all cases, but is the better default. */
1212 /* But some attributes specifically apply to templates. */
1217 else
1219 }
1220 else
1222 }
1224 /* ATTR_P is a list of attributes. Remove any attributes which need to be
1225 applied at instantiation time and return them. If IS_DEPENDENT is true,
1226 the declaration itself is dependent, so all attributes should be applied
1227 at instantiation time. */
1229 static tree
1231 {
1240 {
1242 {
1248 }
1249 else
1251 }
1254 }
1256 /* Remove any late attributes from the list in ATTR_P and attach them to
1257 DECL_P. */
1259 static void
1261 {
1273 else
1278 /* Merge the late attributes at the beginning with the attribute
1279 list. */
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 /* Return true iff ATTRS are acceptable attributes to be applied in-place
1299 to a typedef which gives a previously anonymous class or enum a name for
1300 linkage purposes. */
1302 bool
1304 {
1306 {
1310 }
1312 }
1314 /* Like reconstruct_complex_type, but handle also template trees. */
1316 tree
1318 {
1323 {
1327 }
1329 {
1333 }
1335 {
1338 /* Don't call cp_build_qualified_type on ARRAY_TYPEs, the
1339 element type qualification will be handled by the recursive
1340 cp_reconstruct_complex_type call and cp_build_qualified_type
1341 for ARRAY_TYPEs changes the element type. */
1343 }
1345 {
1352 }
1354 {
1357 /* The build_method_type_directly() routine prepends 'this' to argument list,
1358 so we must compensate by getting rid of it. */
1359 outer
1360 = build_method_type_directly
1363 }
1365 {
1368 }
1369 else
1380 }
1382 /* Replaces any constexpr expression that may be into the attributes
1383 arguments with their reduced value. */
1385 static void
1387 {
1391 tree attr;
1393 {
1394 tree arg;
1396 {
1400 }
1401 }
1402 }
1404 /* Return true if TYPE is an OpenMP mappable type. */
1405 bool
1407 {
1408 /* Mappable type has to be complete. */
1411 /* Arrays have mappable type if the elements have mappable type. */
1414 /* A mappable type cannot contain virtual members. */
1417 /* All data members must be non-static. */
1419 {
1420 tree field;
1424 /* All fields must have mappable types. */
1428 }
1430 }
1432 /* Like decl_attributes, but handle C++ complexity. */
1434 void
1436 {
1441 /* Add implicit "omp declare target" attribute if requested. */
1445 {
1460 else
1463 }
1466 {
1471 }
1479 {
1480 attributes
1484 }
1485 else
1491 /* Propagate deprecation out to the template. */
1494 {
1500 }
1501 }
1502 \f
1503 /* Walks through the namespace- or function-scope anonymous union
1504 OBJECT, with the indicated TYPE, building appropriate VAR_DECLs.
1505 Returns one of the fields for use in the mangled name. */
1507 static tree
1509 {
1511 tree field;
1513 /* Rather than write the code to handle the non-union case,
1514 just give an error. */
1516 {
1519 }
1524 {
1525 tree decl;
1526 tree ref;
1531 {
1535 }
1545 else
1550 {
1551 tree base;
1567 }
1570 else
1575 }
1578 }
1580 /* Finish off the processing of a UNION_TYPE structure. If the union is an
1581 anonymous union, then all members must be laid out together. PUBLIC_P
1582 is nonzero if this union is not declared static. */
1584 void
1586 {
1587 tree type;
1588 tree main_decl;
1597 /* The VAR_DECL's context is the same as the TYPE's context. */
1604 {
1607 }
1613 {
1616 }
1619 {
1620 /* Use main_decl to set the mangled name. */
1626 }
1630 }
1631 \f
1632 /* Auxiliary functions to make type signatures for
1633 `operator new' and `operator delete' correspond to
1634 what compiler will be expecting. */
1636 tree
1638 {
1645 {
1648 }
1651 {
1653 {
1654 /* [basic.stc.dynamic.allocation]
1656 The first parameter shall not have an associated default
1657 argument. */
1660 /* Throw away the default argument. */
1662 }
1665 {
1668 }
1669 }
1670 else
1678 {
1681 /* Fall through. */
1683 type = build_exception_variant
1686 /* Fall through. */
1688 }
1690 }
1692 tree
1694 {
1701 {
1704 }
1708 {
1713 ptr_type_node);
1714 }
1716 {
1719 /* Fall through. */
1721 type = build_exception_variant
1724 /* Fall through. */
1726 }
1729 }
1730 \f
1731 /* DECL is a VAR_DECL for a vtable: walk through the entries in the vtable
1732 and mark them as needed. */
1734 static void
1736 {
1737 tree fnaddr;
1742 {
1743 tree fn;
1749 /* This entry is an offset: a virtual base class offset, a
1750 virtual call offset, an RTTI offset, etc. */
1755 /* When we don't have vcall offsets, we output thunks whenever
1756 we output the vtables that contain them. With vcall offsets,
1757 we know all the thunks we'll need when we emit a virtual
1758 function, so we emit the thunks there instead. */
1762 }
1763 }
1765 /* Set DECL up to have the closest approximation of "initialized common"
1766 linkage available. */
1768 void
1770 {
1775 /* We can just emit function and compiler-generated variables
1776 statically; having multiple copies is (for the most part) only
1777 a waste of space.
1779 There are two correctness issues, however: the address of a
1780 template instantiation with external linkage should be the
1781 same, independent of what translation unit asks for the
1782 address, and this will not hold when we emit multiple copies of
1783 the function. However, there's little else we can do.
1785 Also, by default, the typeinfo implementation assumes that
1786 there will be only one copy of the string used as the name for
1787 each type. Therefore, if weak symbols are unavailable, the
1788 run-time library should perform a more conservative check; it
1789 should perform a string comparison, rather than an address
1790 comparison. */
1792 else
1793 {
1794 /* Static data member template instantiations, however, cannot
1795 have multiple copies. */
1800 {
1803 }
1805 {
1806 /* We can't do anything useful; leave vars for explicit
1807 instantiation. */
1810 }
1811 }
1814 }
1816 /* For win32 we also want to put explicit instantiations in
1817 linkonce sections, so that they will be merged with implicit
1818 instantiations; otherwise we get duplicate symbol errors.
1819 For Darwin we do not want explicit instantiations to be
1820 linkonce. */
1822 void
1824 {
1825 /* We used to say that this was not necessary on targets that support weak
1826 symbols, because the implicit instantiations will defer to the explicit
1827 one. However, that's not actually the case in SVR4; a strong definition
1828 after a weak one is an error. Also, not making explicit
1829 instantiations one_only means that we can end up with two copies of
1830 some template instantiations. */
1834 /* We can't set DECL_COMDAT on functions, or cp_finish_file will think
1835 we can get away with not emitting them if they aren't used. We need
1836 to for variables so that cp_finish_decl will update their linkage,
1837 because their DECL_INITIAL may not have been set properly yet. */
1842 {
1846 {
1849 /* Mark it needed so we don't forget to emit it. */
1852 }
1853 }
1854 }
1856 /* Returns true iff DECL, a FUNCTION_DECL or VAR_DECL, has vague linkage.
1857 This predicate will give the right answer during parsing of the
1858 function, which other tests may not. */
1860 bool
1862 {
1863 /* Unfortunately, import_export_decl has not always been called
1864 before the function is processed, so we cannot simply check
1865 DECL_COMDAT. */
1874 /* A local static in an inline effectively has vague linkage. */
1877 else
1879 }
1881 /* Determine whether or not we want to specifically import or export CTYPE,
1882 using various heuristics. */
1884 static void
1886 {
1887 /* -1 for imported, 1 for exported. */
1890 /* It only makes sense to call this function at EOF. The reason is
1891 that this function looks at whether or not the first non-inline
1892 non-abstract virtual member function has been defined in this
1893 translation unit. But, we can't possibly know that until we've
1894 seen the entire translation unit. */
1900 /* If MULTIPLE_SYMBOL_SPACES is set and we saw a #pragma interface,
1901 we will have CLASSTYPE_INTERFACE_ONLY set but not
1902 CLASSTYPE_INTERFACE_KNOWN. In that case, we don't want to use this
1903 heuristic because someone will supply a #pragma implementation
1904 elsewhere, and deducing it here would produce a conflict. */
1914 /* For a template class, without -fimplicit-templates, check the
1915 repository. If the virtual table is assigned to this
1916 translation unit, then export the class; otherwise, import
1917 it. */
1920 {
1921 /* The ABI specifies that the virtual table and associated
1922 information are emitted with the key method, if any. */
1924 /* If weak symbol support is not available, then we must be
1925 careful not to emit the vtable when the key function is
1926 inline. An inline function can be defined in multiple
1927 translation units. If we were to emit the vtable in each
1928 translation unit containing a definition, we would get
1929 multiple definition errors at link-time. */
1932 }
1934 /* When MULTIPLE_SYMBOL_SPACES is set, we cannot count on seeing
1935 a definition anywhere else. */
1939 /* Allow back ends the chance to overrule the decision. */
1944 {
1947 }
1948 }
1950 /* Return true if VAR has already been provided to the back end; in that
1951 case VAR should not be modified further by the front end. */
1952 static bool
1954 {
1956 }
1958 /* DECL is a VAR_DECL or FUNCTION_DECL which, for whatever reason,
1959 must be emitted in this translation unit. Mark it as such. */
1961 void
1963 {
1966 {
1967 /* Extern inline functions don't become needed when referenced.
1968 If we know a method will be emitted in other TU and no new
1969 functions can be marked reachable, just use the external
1970 definition. */
1974 /* #pragma interface and -frepo code can call mark_needed for
1975 maybe-in-charge 'tors; mark the clones as well. */
1976 tree clone;
1979 }
1981 {
1983 /* C++ frontend use mark_decl_references to force COMDAT variables
1984 to be output that might appear dead otherwise. */
1986 }
1987 }
1989 /* DECL is either a FUNCTION_DECL or a VAR_DECL. This function
1990 returns true if a definition of this entity should be provided in
1991 this object file. Callers use this function to determine whether
1992 or not to let the back end know that a definition of DECL is
1993 available in this translation unit. */
1995 bool
1997 {
1999 /* This function should only be called at the end of the translation
2000 unit. We cannot be sure of whether or not something will be
2001 COMDAT until that point. */
2004 /* All entities with external linkage that are not COMDAT/EXTERN should be
2005 emitted; they may be referred to from other object files. */
2008 /* Functions marked "dllexport" must be emitted so that they are
2009 visible to other DLLs. */
2014 /* When not optimizing, do not bother to produce definitions for extern
2015 symbols. */
2024 /* If this entity was used, let the back end see it; it will decide
2025 whether or not to emit it into the object file. */
2028 /* Virtual functions might be needed for devirtualization. */
2033 /* Otherwise, DECL does not need to be emitted -- yet. A subsequent
2034 reference to DECL might cause it to be emitted later. */
2036 }
2038 /* If necessary, write out the vtables for the dynamic class CTYPE.
2039 Returns true if any vtables were emitted. */
2041 static bool
2043 {
2044 tree vtbl;
2045 tree primary_vtbl;
2049 /* If the vtables for this class have already been emitted there is
2050 nothing more to do. */
2054 /* Ignore dummy vtables made by get_vtable_decl. */
2058 /* On some targets, we cannot determine the key method until the end
2059 of the translation unit -- which is when this function is
2060 called. */
2064 /* See if any of the vtables are needed. */
2066 {
2070 }
2072 {
2073 /* If the references to this class' vtables are optimized away,
2074 still emit the appropriate debugging information. See
2075 dfs_debug_mark. */
2080 }
2082 /* The ABI requires that we emit all of the vtables if we emit any
2083 of them. */
2085 {
2086 /* Mark entities references from the virtual table as used. */
2090 {
2093 LOOKUP_NORMAL);
2095 /* It had better be all done at compile-time. */
2097 }
2099 /* Write it out. */
2103 /* Because we're only doing syntax-checking, we'll never end up
2104 actually marking the variable as written. */
2108 {
2113 }
2114 }
2116 /* Since we're writing out the vtable here, also write the debug
2117 info. */
2121 }
2123 /* A special return value from type_visibility meaning internal
2124 linkage. */
2128 /* walk_tree helper function for type_visibility. */
2130 static tree
2132 {
2135 {
2137 }
2140 {
2143 }
2148 }
2150 /* Returns the visibility of TYPE, which is the minimum visibility of its
2151 component types. */
2153 static int
2155 {
2159 }
2161 /* Limit the visibility of DECL to VISIBILITY, if not explicitly
2162 specified (or if VISIBILITY is static). If TMPL is true, this
2163 constraint is for a template argument, and takes precedence
2164 over explicitly-specified visibility on the template. */
2166 static void
2168 {
2170 {
2171 /* extern "C" declarations aren't affected by the anonymous
2172 namespace. */
2174 {
2181 {
2186 }
2190 }
2191 }
2194 {
2196 /* This visibility was not specified. */
2198 }
2199 }
2201 /* Constrain the visibility of DECL based on the visibility of its template
2202 arguments. */
2204 static void
2206 {
2207 /* If this is a template instantiation, check the innermost
2208 template args for visibility constraints. The outer template
2209 args are covered by the class check. */
2213 {
2219 else
2220 {
2228 {
2231 else
2233 }
2234 }
2237 }
2238 }
2240 /* Like c_determine_visibility, but with additional C++-specific
2241 behavior.
2243 Function-scope entities can rely on the function's visibility because
2244 it is set in start_preparsed_function.
2246 Class-scope entities cannot rely on the class's visibility until the end
2247 of the enclosing class definition.
2249 Note that because namespaces have multiple independent definitions,
2250 namespace visibility is handled elsewhere using the #pragma visibility
2251 machinery rather than by decorating the namespace declaration.
2253 The goal is for constraints from the type to give a diagnostic, and
2254 other constraints to be applied silently. */
2256 void
2258 {
2264 /* Remember that all decls get VISIBILITY_DEFAULT when built. */
2266 /* Only relevant for names with external linkage. */
2270 /* Cloned constructors and destructors get the same visibility as
2271 the underlying function. That should be set up in
2272 maybe_clone_body. */
2279 {
2284 else
2286 }
2289 else
2292 /* If DECL is a member of a class, visibility specifiers on the
2293 class can influence the visibility of the DECL. */
2296 else
2297 {
2298 /* Not a class member. */
2300 /* Virtual tables have DECL_CONTEXT set to their associated class,
2301 so they are automatically handled above. */
2306 {
2307 /* Local statics and classes get the visibility of their
2308 containing function by default, except that
2309 -fvisibility-inlines-hidden doesn't affect them. */
2312 {
2316 }
2317 else
2318 {
2322 {
2326 }
2327 else
2328 {
2332 }
2333 }
2335 /* Local classes in templates have CLASSTYPE_USE_TEMPLATE set,
2336 but have no TEMPLATE_INFO, so don't try to check it. */
2338 }
2341 {
2342 /* Under -fvisibility-ms-compat, types are visible by default,
2343 even though their contents aren't. */
2350 else
2352 }
2354 {
2355 /* tinfo visibility is based on the type it's for. */
2356 constrain_visibility
2359 /* Give the target a chance to override the visibility associated
2360 with DECL. */
2366 }
2368 /* Template instantiations and specializations get visibility based
2371 {
2374 else
2375 {
2376 /* Set default visibility to whatever the user supplied with
2377 #pragma GCC visibility or a namespace visibility attribute. */
2380 }
2381 }
2382 }
2385 {
2386 /* If the specialization doesn't specify visibility, use the
2387 visibility from the template. */
2397 {
2401 {
2405 else
2406 {
2410 }
2411 }
2414 /* Template argument visibility outweighs #pragma or namespace
2415 visibility, but not an explicit attribute. */
2417 {
2420 {
2421 /* A class template member with explicit visibility
2422 overrides the class visibility, so we need to apply
2423 all the levels of template args directly. */
2426 {
2429 }
2430 }
2432 /* Limit visibility based on its template arguments. */
2434 }
2435 }
2436 }
2442 /* Names in an anonymous namespace get internal linkage.
2443 This might change once we implement export. */
2446 {
2447 /* Propagate anonymity from type to decl. */
2452 }
2454 /* DR 757: A type without linkage shall not be used as the type of a
2455 variable or function with linkage, unless
2456 o the variable or function has extern "C" linkage (7.5 [dcl.link]), or
2457 o the variable or function is not used (3.2 [basic.def.odr]) or is
2458 defined in the same translation unit.
2460 Since non-extern "C" decls need to be defined in the same
2461 translation unit, we can make the type internal. */
2464 /* If visibility changed and DECL already has DECL_RTL, ensure
2465 symbol flags are updated. */
2472 }
2474 /* By default, static data members and function members receive
2475 the visibility of their containing class. */
2477 static void
2479 {
2485 else
2486 {
2487 /* Default to the class visibility. */
2491 }
2493 /* Give the target a chance to override the visibility associated
2494 with DECL. */
2498 /* Construction virtual tables are not exported because
2499 they cannot be referred to from other object files;
2500 their name is not standardized by the ABI. */
2506 }
2508 /* Returns true iff DECL is an inline that should get hidden visibility
2509 because of -fvisibility-inlines-hidden. */
2511 static bool
2513 {
2515 /* Don't do this for inline templates; specializations might not be
2516 inline, and we don't want them to inherit the hidden
2517 visibility. We'll set it here for all inline instantiations. */
2518 && !processing_template_decl
2523 }
2525 /* Constrain the visibility of a class TYPE based on the visibility of its
2526 field types. Warn if any fields require lesser visibility. */
2528 void
2530 {
2531 tree binfo;
2532 tree t;
2541 /* Don't warn about visibility if the class has explicit visibility. */
2547 {
2552 {
2557 }
2564 }
2568 {
2572 {
2577 }
2583 }
2584 }
2586 /* Functions for adjusting the visibility of a tagged type and its nested
2587 types and declarations when it gets a name for linkage purposes from a
2588 typedef. */
2593 /* First reset the visibility of all the types. */
2595 static void
2597 {
2602 }
2603 static void
2605 {
2607 }
2609 /* Then reset the visibility of any static data members or member
2610 functions that use those types. */
2612 static void
2614 {
2623 }
2624 static void
2626 {
2628 {
2630 {
2635 }
2637 {
2643 }
2651 }
2652 }
2653 static void
2655 {
2657 }
2658 void
2660 {
2663 }
2665 /* Set up our initial idea of what the linkage of DECL should be. */
2667 void
2669 {
2671 /* We've already made a decision as to how this function will
2674 {
2677 {
2681 /* A non-template inline function with external linkage will
2682 always be COMDAT. As we must eventually determine the
2683 linkage of all functions, and as that causes writes to
2684 the data mapped in from the PCH file, it's advantageous
2685 to mark the functions at this point. */
2689 {
2690 /* This function must have external linkage, as
2691 otherwise DECL_INTERFACE_KNOWN would have been
2692 set. */
2696 }
2697 }
2700 }
2701 }
2703 /* DECL is a FUNCTION_DECL or VAR_DECL. If the object file linkage
2704 for DECL has not already been determined, do so now by setting
2705 DECL_EXTERNAL, DECL_COMDAT and other related flags. Until this
2706 function is called entities with vague linkage whose definitions
2707 are available must have TREE_PUBLIC set.
2709 If this function decides to place DECL in COMDAT, it will set
2710 appropriate flags -- but will not clear DECL_EXTERNAL. It is up to
2711 the caller to decide whether or not to clear DECL_EXTERNAL. Some
2712 callers defer that decision until it is clear that DECL is actually
2713 required. */
2715 void
2717 {
2726 /* We cannot determine what linkage to give to an entity with vague
2727 linkage until the end of the file. For example, a virtual table
2728 for a class will be defined if and only if the key method is
2729 defined in this translation unit. As a further example, consider
2730 that when compiling a translation unit that uses PCH file with
2731 "-frepo" it would be incorrect to make decisions about what
2732 entities to emit when building the PCH; those decisions must be
2733 delayed until the repository information has been processed. */
2735 /* Object file linkage for explicit instantiations is handled in
2736 mark_decl_instantiated. For static variables in functions with
2737 vague linkage, maybe_commonize_var is used.
2739 Therefore, the only declarations that should be provided to this
2740 function are those with external linkage that are:
2742 * implicit instantiations of function templates
2744 * inline function
2746 * implicit instantiations of static data members of class
2747 templates
2749 * virtual tables
2751 * typeinfo objects
2753 Furthermore, all entities that reach this point must have a
2754 definition available in this translation unit.
2756 The following assertions check these conditions. */
2758 /* Any code that creates entities with TREE_PUBLIC cleared should
2759 also set DECL_INTERFACE_KNOWN. */
2765 else
2769 /* Check that a definition of DECL is available in this translation
2770 unit. */
2773 /* Assume that DECL will not have COMDAT linkage. */
2775 /* Assume that DECL will not be imported into this translation
2776 unit. */
2779 /* See if the repository tells us whether or not to emit DECL in
2780 this translation unit. */
2785 {
2786 /* The repository indicates that this entity should be defined
2787 here. Make sure the back end honors that request. */
2789 /* Output the definition as an ordinary strong definition. */
2793 }
2796 /* We have already decided what to do with this DECL; there is no
2797 need to check anything further. */
2798 ;
2800 {
2812 /* The ABI requires that all virtual tables be emitted with
2813 COMDAT linkage. However, on systems where COMDAT symbols
2814 don't show up in the table of contents for a static
2815 archive, or on systems without weak symbols (where we
2816 approximate COMDAT linkage by using internal linkage), the
2817 linker will report errors about undefined symbols because
2818 it will not see the virtual table definition. Therefore,
2819 in the case that we know that the virtual table will be
2820 emitted in only one translation unit, we make the virtual
2821 table an ordinary definition with external linkage. */
2824 {
2825 /* CLASS_TYPE is being exported from this translation unit,
2826 so DECL should be defined here. */
2828 /* If a class is declared in a header with the "extern
2829 template" extension, then it will not be instantiated,
2830 even in translation units that would normally require
2831 it. Often such classes are explicitly instantiated in
2832 one translation unit. Therefore, the explicit
2833 instantiation must be made visible to other translation
2834 units. */
2836 else
2837 {
2838 /* The generic C++ ABI says that class data is always
2839 COMDAT, even if there is a key function. Some
2840 variants (e.g., the ARM EABI) says that class data
2841 only has COMDAT linkage if the class data might be
2842 emitted in more than one translation unit. When the
2843 key method can be inline and is inline, we still have
2844 to arrange for comdat even though
2845 class_data_always_comdat is false. */
2849 {
2850 /* The ABI requires COMDAT linkage. Normally, we
2851 only emit COMDAT things when they are needed;
2852 make sure that we realize that this entity is
2853 indeed needed. */
2856 }
2857 }
2858 }
2862 else
2864 }
2866 {
2869 {
2875 /* If -fno-rtti was specified, then we cannot be sure
2876 that RTTI information will be emitted with the
2877 virtual table of the class, so we must emit it
2878 wherever it is used. */
2881 else
2882 {
2885 {
2891 {
2894 }
2895 }
2896 else
2898 }
2899 }
2900 else
2902 }
2904 {
2905 /* DECL is an implicit instantiation of a function or static
2906 data member. */
2909 || (flag_implicit_inline_templates
2913 else
2914 /* If we are not implicitly generating templates, then mark
2915 this entity as undefined in this translation unit. */
2917 }
2919 {
2921 {
2925 {
2929 && ! flag_implement_inlines
2935 /* Always make artificials weak. */
2938 else
2940 }
2941 }
2942 else
2944 }
2945 else
2949 {
2950 /* If we are importing DECL into this translation unit, mark is
2951 an undefined here. */
2954 }
2956 {
2957 /* If we decided to put DECL in COMDAT, mark it accordingly at
2958 this point. */
2960 }
2963 }
2965 /* Return an expression that performs the destruction of DECL, which
2966 must be a VAR_DECL whose type has a non-trivial destructor, or is
2967 an array whose (innermost) elements have a non-trivial destructor. */
2969 tree
2971 {
2975 }
2977 /* Returns the initialization guard variable for the variable DECL,
2978 which has static storage duration. */
2980 tree
2982 {
2983 tree sname;
2984 tree guard;
2989 {
2990 tree guard_type;
2992 /* We use a type that is big enough to contain a mutex as well
2993 as an integer counter. */
2998 /* The guard should have the same linkage as what it guards. */
3015 }
3017 }
3019 /* Return those bits of the GUARD variable that should be set when the
3020 guarded entity is actually initialized. */
3022 static tree
3024 {
3026 {
3027 /* We only set the first byte of the guard, in order to leave room
3028 for a mutex in the high-order bits. */
3031 guard);
3034 guard);
3036 }
3039 }
3041 /* Return an expression which determines whether or not the GUARD
3042 variable has already been initialized. */
3044 tree
3046 {
3047 tree guard_value;
3049 /* Check to see if the GUARD is zero. */
3052 /* Mask off all but the low bit. */
3054 {
3060 tf_warning_or_error);
3061 }
3068 tf_warning_or_error);
3069 }
3071 /* Return an expression which sets the GUARD variable, indicating that
3072 the variable being guarded has been initialized. */
3074 tree
3076 {
3077 tree guard_init;
3079 /* Set the GUARD to one. */
3085 tf_warning_or_error);
3086 }
3088 /* Returns true iff we can tell that VAR does not have a dynamic
3089 initializer. */
3091 static bool
3093 {
3094 /* If it's defined in another TU, we can't tell. */
3097 /* If it has a non-trivial destructor, registering the destructor
3098 counts as dynamic initialization. */
3101 /* If it's in this TU, its initializer has been processed, unless
3102 it's a case of self-initialization, then DECL_INITIALIZED_P is
3103 false while the initializer is handled by finish_id_expression. */
3106 /* If it has no initializer or a constant one, it's not dynamic. */
3109 }
3111 /* Returns true iff VAR is a variable that needs uses to be
3112 wrapped for possible dynamic initialization. */
3114 static bool
3116 {
3122 }
3124 /* Get the FUNCTION_DECL for the shared TLS init function for this
3125 translation unit. */
3127 static tree
3129 {
3133 {
3136 void_list_node));
3142 }
3144 }
3146 /* Get a FUNCTION_DECL for the init function for the thread_local
3147 variable VAR. The init function will be an alias to the function
3148 that initializes all the non-local TLS variables in the translation
3149 unit. The init function is only used by the wrapper function. */
3151 static tree
3153 {
3154 /* Only C++11 TLS vars need this init fn. */
3158 /* If -fno-extern-tls-init, assume that we don't need to call
3159 a tls init function for a variable defined in another TU. */
3163 #ifdef ASM_OUTPUT_DEF
3164 /* If the variable is internal, or if we can't generate aliases,
3165 call the local init function directly. */
3167 #endif
3173 {
3176 void_list_node));
3185 {
3187 /* If the variable is defined somewhere else and might have static
3188 initialization, make the init function a weak reference. */
3194 else
3196 }
3206 }
3208 }
3210 /* Get a FUNCTION_DECL for the init wrapper function for the thread_local
3211 variable VAR. The wrapper function calls the init function (if any) for
3212 VAR and then returns a reference to VAR. The wrapper function is used
3213 in place of VAR everywhere VAR is mentioned. */
3215 tree
3217 {
3218 /* Only C++11 TLS vars need this wrapper fn. */
3225 {
3226 /* A named rvalue reference is an lvalue, so the wrapper should
3227 always return an lvalue reference. */
3236 /* The wrapper is inline and emitted everywhere var is used. */
3239 {
3241 #ifdef HAVE_GAS_HIDDEN
3242 /* Make the wrapper bind locally; there's no reason to share
3243 the wrapper between multiple shared objects. */
3246 #endif
3247 }
3253 #if 0
3254 /* We want CSE to commonize calls to the wrapper, but marking it as
3255 pure is unsafe since it has side-effects. I guess we need a new
3256 ECF flag even weaker than ECF_PURE. FIXME! */
3258 #endif
3263 }
3265 }
3267 /* At EOF, generate the definition for the TLS wrapper function FN:
3269 T& var_wrapper() {
3270 if (init_fn) init_fn();
3271 return var;
3272 } */
3274 static void
3276 {
3281 /* Only call the init fn if there might be one. */
3283 {
3285 /* If init_fn is a weakref, make sure it exists before calling. */
3287 {
3292 tf_warning_or_error);
3294 }
3298 {
3301 }
3302 }
3303 else
3304 /* If there's no initialization, the wrapper is a constant function. */
3309 }
3311 /* Start the process of running a particular set of global constructors
3312 or destructors. Subroutine of do_[cd]tors. Also called from
3313 vtv_start_verification_constructor_init_function. */
3315 static tree
3317 {
3318 tree body;
3319 tree fndecl;
3322 /* Make ctor or dtor function. METHOD_TYPE may be 'I' or 'D'. */
3325 {
3328 #ifdef JOINER
3330 #else
3332 #endif
3335 }
3336 else
3342 NULL_TREE));
3347 /* Mark as artificial because it's not explicitly in the user's
3348 source code. */
3351 /* Mark this declaration as used to avoid spurious warnings. */
3354 /* Mark this function as a global constructor or destructor. */
3357 else
3363 }
3365 /* Finish the process of running a particular set of global constructors
3366 or destructors. Subroutine of do_[cd]tors. */
3368 static void
3370 {
3371 tree fn;
3373 /* Finish up. */
3378 {
3381 }
3382 else
3383 {
3386 }
3389 }
3391 /* The names of the parameters to the function created to handle
3392 initializations and destructions for objects with static storage
3393 duration. */
3397 /* The name of the function we create to handle initializations and
3398 destructions for objects with static storage duration. */
3401 /* The declaration for the __INITIALIZE_P argument. */
3404 /* The declaration for the __PRIORITY argument. */
3407 /* The declaration for the static storage duration function. */
3410 /* All the static storage duration functions created in this
3411 translation unit. */
3414 /* A map from priority levels to information about that priority
3415 level. There may be many such levels, so efficient lookup is
3416 important. */
3419 /* Begins the generation of the function that will handle all
3420 initialization and destruction of objects with static storage
3421 duration. The function generated takes two parameters of type
3422 `int': __INITIALIZE_P and __PRIORITY. If __INITIALIZE_P is
3423 nonzero, it performs initializations. Otherwise, it performs
3424 destructions. It only performs those initializations or
3425 destructions with the indicated __PRIORITY. The generated function
3426 returns no value.
3428 It is assumed that this function will only be called once per
3429 translation unit. */
3431 static tree
3433 {
3434 tree type;
3435 tree body;
3438 /* Create the identifier for this function. It will be of the form
3439 SSDF_IDENTIFIER_<number>. */
3444 NULL_TREE);
3446 /* Create the FUNCTION_DECL itself. */
3449 type);
3453 /* Put this function in the list of functions to be called from the
3454 static constructors and destructors. */
3456 {
3459 /* Take this opportunity to initialize the map from priority
3460 numbers to information about that priority level. */
3463 /*delete_value_fn=*/
3466 /* We always need to generate functions for the
3467 DEFAULT_INIT_PRIORITY so enter it now. That way when we walk
3468 priorities later, we'll be sure to find the
3469 DEFAULT_INIT_PRIORITY. */
3471 }
3475 /* Create the argument list. */
3476 initialize_p_decl = cp_build_parm_decl
3480 priority_decl = cp_build_parm_decl
3488 /* Put the function in the global scope. */
3491 /* Start the function itself. This is equivalent to declaring the
3492 function as:
3494 static void __ssdf (int __initialize_p, init __priority_p);
3496 It is static because we only need to call this function from the
3497 various constructor and destructor functions for this module. */
3500 SF_PRE_PARSED);
3502 /* Set up the scope of the outermost block in the function. */
3506 }
3508 /* Finish the generation of the function which performs initialization
3509 and destruction of objects with static storage duration. After
3510 this point, no more such objects can be created. */
3512 static void
3514 {
3515 /* Close out the function. */
3518 }
3520 /* Return the information about the indicated PRIORITY level. If no
3521 code to handle this level has yet been generated, generate the
3522 appropriate prologue. */
3524 static priority_info
3526 {
3527 priority_info pi;
3528 splay_tree_node n;
3533 {
3534 /* Create a new priority information structure, and insert it
3535 into the map. */
3542 }
3543 else
3547 }
3549 /* The effective initialization priority of a DECL. */
3551 #define DECL_EFFECTIVE_INIT_PRIORITY(decl) \
3552 ((!DECL_HAS_INIT_PRIORITY_P (decl) || DECL_INIT_PRIORITY (decl) == 0) \
3553 ? DEFAULT_INIT_PRIORITY : DECL_INIT_PRIORITY (decl))
3555 /* Whether a DECL needs a guard to protect it against multiple
3556 initialization. */
3558 #define NEEDS_GUARD_P(decl) (TREE_PUBLIC (decl) && (DECL_COMMON (decl) \
3559 || DECL_ONE_ONLY (decl) \
3560 || DECL_WEAK (decl)))
3562 /* Called from one_static_initialization_or_destruction(),
3563 via walk_tree.
3564 Walks the initializer list of a global variable and looks for
3565 temporary variables (DECL_NAME() == NULL and DECL_ARTIFICIAL != 0)
3566 and that have their DECL_CONTEXT() == NULL.
3567 For each such temporary variable, set their DECL_CONTEXT() to
3568 the current function. This is necessary because otherwise
3569 some optimizers (enabled by -O2 -fprofile-arcs) might crash
3570 when trying to refer to a temporary variable that does not have
3571 it's DECL_CONTECT() properly set. */
3572 static tree
3576 {
3580 {
3581 tree var;
3589 }
3592 }
3594 /* Set up to handle the initialization or destruction of DECL. If
3595 INITP is nonzero, we are initializing the variable. Otherwise, we
3596 are destroying it. */
3598 static void
3600 {
3602 tree guard;
3604 /* If we are supposed to destruct and there's a trivial destructor,
3605 nothing has to be done. */
3610 /* Trick the compiler into thinking we are at the file and line
3611 where DECL was declared so that error-messages make sense, and so
3612 that the debugger will show somewhat sensible file and line
3613 information. */
3616 /* Make sure temporary variables in the initialiser all have
3617 their DECL_CONTEXT() set to a value different from NULL_TREE.
3618 This can happen when global variables initialisers are built.
3619 In that case, the DECL_CONTEXT() of the global variables _AND_ of all
3620 the temporary variables that might have been generated in the
3621 accompagning initialisers is NULL_TREE, meaning the variables have been
3622 declared in the global namespace.
3623 What we want to do here is to fix that and make sure the DECL_CONTEXT()
3624 of the temporaries are set to the current function decl. */
3626 fix_temporary_vars_context_r,
3627 NULL);
3629 /* Because of:
3631 [class.access.spec]
3633 Access control for implicit calls to the constructors,
3634 the conversion functions, or the destructor called to
3635 create and destroy a static data member is performed as
3636 if these calls appeared in the scope of the member's
3637 class.
3639 we pretend we are in a static member function of the class of
3640 which the DECL is a member. */
3642 {
3645 }
3647 /* Assume we don't need a guard. */
3649 /* We need a guard if this is an object with external linkage that
3650 might be initialized in more than one place. (For example, a
3651 static data member of a template, when the data member requires
3652 construction.) */
3654 {
3655 tree guard_cond;
3659 /* When using __cxa_atexit, we just check the GUARD as we would
3660 for a local static. */
3662 {
3663 /* When using __cxa_atexit, we never try to destroy
3664 anything from a static destructor. */
3667 }
3668 /* If we don't have __cxa_atexit, then we will be running
3669 destructors from .fini sections, or their equivalents. So,
3670 we need to know how many times we've tried to initialize this
3671 object. We do initializations only if the GUARD is zero,
3672 i.e., if we are the first to initialize the variable. We do
3673 destructions only if the GUARD is one, i.e., if we are the
3674 last to destroy the variable. */
3676 guard_cond
3678 EQ_EXPR,
3680 guard,
3682 tf_warning_or_error),
3683 integer_one_node,
3684 tf_warning_or_error);
3685 else
3686 guard_cond
3688 EQ_EXPR,
3690 guard,
3692 tf_warning_or_error),
3693 integer_zero_node,
3694 tf_warning_or_error);
3698 }
3701 /* If we're using __cxa_atexit, we have not already set the GUARD,
3702 so we must do so now. */
3706 /* Perform the initialization or destruction. */
3708 {
3710 {
3713 {
3717 }
3718 }
3720 /* If we're using __cxa_atexit, register a function that calls the
3721 destructor for the object. */
3724 }
3725 else
3728 /* Finish the guard if-stmt, if necessary. */
3730 {
3733 }
3735 /* Now that we're done with DECL we don't need to pretend to be a
3736 member of its class any longer. */
3739 }
3741 /* Generate code to do the initialization or destruction of the decls in VARS,
3742 a TREE_LIST of VAR_DECL with static storage duration.
3743 Whether initialization or destruction is performed is specified by INITP. */
3745 static void
3747 {
3750 /* Build the outer if-stmt to check for initialization or destruction. */
3754 EQ_EXPR,
3755 initialize_p_decl,
3756 cond,
3757 tf_warning_or_error);
3760 /* To make sure dynamic construction doesn't access globals from other
3761 compilation units where they might not be yet constructed, for
3762 -fsanitize=address insert __asan_before_dynamic_init call that
3763 prevents access to either all global variables that need construction
3764 in other compilation units, or at least those that haven't been
3765 initialized yet. Variables that need dynamic construction in
3766 the current compilation unit are kept accessible. */
3773 tree priority_if_stmt;
3775 priority_info pi;
3777 /* If we don't need a destructor, there's nothing to do. Avoid
3778 creating a possibly empty if-stmt. */
3780 {
3783 }
3785 /* Remember that we had an initialization or finalization at this
3786 priority. */
3791 else
3794 /* Conditionalize this initialization on being in the right priority
3795 and being initializing/finalizing appropriately. */
3798 EQ_EXPR,
3799 priority_decl,
3801 tf_warning_or_error);
3804 /* Process initializers with same priority. */
3808 /* Do one initialization or destruction. */
3812 /* Finish up the priority if-stmt body. */
3818 /* Revert what __asan_before_dynamic_init did by calling
3819 __asan_after_dynamic_init. */
3823 /* Finish up the init/destruct if-stmt body. */
3826 }
3828 /* VARS is a list of variables with static storage duration which may
3829 need initialization and/or finalization. Remove those variables
3830 that don't really need to be initialized or finalized, and return
3831 the resulting list. The order in which the variables appear in
3832 VARS is in reverse order of the order in which they should actually
3833 be initialized. The list we return is in the unreversed order;
3834 i.e., the first variable should be initialized first. */
3836 static tree
3838 {
3843 {
3848 /* Deal gracefully with error. */
3850 {
3853 }
3855 /* The only things that can be initialized are variables. */
3858 /* If this object is not defined, we don't need to do anything
3859 here. */
3861 {
3864 }
3866 /* Also, if the initializer already contains errors, we can bail
3867 out now. */
3870 {
3873 }
3875 /* This variable is going to need initialization and/or
3876 finalization, so we add it to the list. */
3880 }
3883 }
3885 /* Make sure we have told the back end about all the variables in
3886 VARS. */
3888 static void
3890 {
3891 tree v;
3894 {
3897 {
3900 }
3901 }
3902 }
3904 /* Generate a static constructor (if CONSTRUCTOR_P) or destructor
3905 (otherwise) that will initialize all global objects with static
3906 storage duration having the indicated PRIORITY. */
3908 static void
3911 {
3913 tree fndecl;
3914 tree body;
3918 /* ??? */
3919 /* Was: locus->line++; */
3921 /* We use `I' to indicate initialization and `D' to indicate
3922 destruction. */
3925 /* We emit the function lazily, to avoid generating empty
3926 global constructors and destructors. */
3929 /* For Objective-C++, we may need to initialize metadata found in this module.
3930 This must be done _before_ any other static initializations. */
3933 {
3936 }
3938 /* Call the static storage duration function with appropriate
3939 arguments. */
3941 {
3942 /* Calls to pure or const functions will expand to nothing. */
3944 {
3945 tree call;
3952 constructor_p),
3954 priority),
3955 NULL_TREE);
3957 }
3958 }
3960 /* Close out the function. */
3963 }
3965 /* Generate constructor and destructor functions for the priority
3966 indicated by N. */
3968 static int
3970 {
3975 /* Generate the functions themselves, but only if they are really
3976 needed. */
3982 /* Keep iterating. */
3984 }
3986 /* Java requires that we be able to reference a local address for a
3987 method, and not be confused by PLT entries. If hidden aliases are
3988 supported, collect and return all the functions for which we should
3989 emit a hidden alias. */
3993 {
3997 #ifndef HAVE_GAS_HIDDEN
3999 #endif
4002 {
4008 {
4012 }
4013 }
4016 }
4019 /* Java requires that we be able to reference a local address for a
4020 method, and not be confused by PLT entries. If hidden aliases are
4021 supported, emit one for each java function that we've emitted.
4022 CANDIDATES is the set of FUNCTION_DECLs that were gathered
4023 by collect_candidates_for_java_method_aliases. */
4025 static void
4027 {
4030 #ifndef HAVE_GAS_HIDDEN
4032 #endif
4035 {
4040 {
4041 /* Mangle the name in a predictable way; we need to reference
4042 this from a java compiled object file. */
4058 }
4059 }
4060 }
4062 /* Return C++ property of T, based on given operation OP. */
4064 static int
4066 {
4068 {
4083 }
4084 }
4086 /* Collect source file references recursively, starting from NAMESPC. */
4088 static void
4090 {
4091 tree t;
4096 /* Iterate over names in this name space. */
4101 /* Dump siblings, if any */
4104 /* Dump children, if any */
4106 }
4108 /* Collect decls relevant to SOURCE_FILE from all namespaces recursively,
4109 starting from NAMESPC. */
4111 static void
4113 {
4117 /* Collect decls from this namespace */
4120 /* Collect siblings, if any */
4123 /* Collect children, if any */
4125 }
4127 /* Returns true iff there is a definition available for variable or
4128 function DECL. */
4130 static bool
4132 {
4135 else
4136 {
4139 }
4140 }
4142 /* Nonzero for a VAR_DECL whose value can be used in a constant expression.
4144 [expr.const]
4146 An integral constant-expression can only involve ... const
4147 variables of integral or enumeration types initialized with
4148 constant expressions ...
4150 C++0x also allows constexpr variables and temporaries initialized
4151 with constant expressions. We handle the former here, but the latter
4152 are just folded away in cxx_eval_constant_expression.
4154 The standard does not require that the expression be non-volatile.
4155 G++ implements the proposed correction in DR 457. */
4157 bool
4159 {
4163 /* We don't know if a template static data member is initialized with
4164 a constant expression until we instantiate its initializer. Even
4165 in the case of a constexpr variable, we can't treat it as a
4166 constant until its initializer is complete in case it's used in
4167 its own initializer. */
4170 }
4172 /* Returns true if DECL could be a symbolic constant variable, depending on
4173 its initializer. */
4175 bool
4177 {
4185 }
4187 /* Complain that DECL uses a type with no linkage. In C++98 mode this is
4188 called from grokfndecl and grokvardecl; in all modes it is called from
4189 cp_write_global_declarations. */
4191 void
4193 {
4195 /* In C++11 it's ok if the decl is defined. */
4199 /* The type that got us on no_linkage_decls must have gotten a name for
4202 /* The type might end up having a typedef name for linkage purposes. */
4205 {
4213 /* DRs 132, 319 and 389 seem to indicate types with
4214 no linkage can only be used to declare extern "C"
4215 entities. Since it's not always an error in the
4216 ISO C++ 90 Standard, we only issue a warning. */
4218 "with no linkage used to declare variable %q#D with "
4220 else
4223 decl);
4228 }
4235 else
4238 }
4240 /* Collect declarations from all namespaces relevant to SOURCE_FILE. */
4242 static void
4244 {
4246 }
4248 /* Clear DECL_EXTERNAL for NODE. */
4250 static bool
4252 {
4255 }
4257 /* Build up the function to run dynamic initializers for thread_local
4258 variables in this translation unit and alias the init functions for the
4259 individual variables to it. */
4261 static void
4263 {
4273 boolean_type_node);
4287 tf_warning_or_error);
4290 tf_warning_or_error));
4292 {
4297 #ifdef ASM_OUTPUT_DEF
4298 /* Output init aliases even with -fno-extern-tls-init. */
4300 {
4304 cgraph_node *alias
4308 }
4309 #endif
4310 }
4316 }
4318 /* The entire file is now complete. If requested, dump everything
4319 to a file. */
4321 static void
4323 {
4328 {
4331 }
4332 }
4334 /* Check the deallocation functions for CODE to see if we want to warn that
4335 only one was defined. */
4337 static void
4339 {
4345 {
4347 /* We're only interested in usual deallocation functions. */
4352 else
4354 }
4361 }
4363 /* Check the global deallocation functions to see if we want to warn about
4364 defining unsized without sized (or vice versa). */
4366 static void
4368 {
4373 }
4375 /* This routine is called at the end of compilation.
4376 Its job is to create all the code needed to initialize and
4377 destroy the global aggregates. We do the destruction
4378 first, since that way we only need to reverse the decls once. */
4380 void
4382 {
4383 tree vars;
4386 location_t locus;
4389 tree decl;
4395 /* Bad parse errors. Just forget about it. */
4400 /* This is the point to write out a PCH if we're doing that.
4401 In that case we do not want to do anything else. */
4403 {
4407 }
4411 /* Handle -fdump-ada-spec[-slim] */
4413 {
4416 else
4420 }
4422 /* FIXME - huh? was input_line -= 1;*/
4426 /* We now have to write out all the stuff we put off writing out.
4427 These include:
4429 o Template specializations that we have not yet instantiated,
4430 but which are needed.
4431 o Initialization and destruction for non-local objects with
4432 static storage duration. (Local objects with static storage
4433 duration are initialized when their scope is first entered,
4434 and are cleaned up via atexit.)
4435 o Virtual function tables.
4437 All of these may cause others to be needed. For example,
4438 instantiating one function may cause another to be needed, and
4439 generating the initializer for an object may cause templates to be
4440 instantiated, etc., etc. */
4444 do
4445 {
4446 tree t;
4447 tree decl;
4451 /* If there are templates that we've put off instantiating, do
4452 them now. */
4456 /* Write out virtual tables as required. Note that writing out
4457 the virtual table for a template class may cause the
4458 instantiation of members of that class. If we write out
4459 vtables then we remove the class from our list so we don't
4460 have to look at it again. */
4464 {
4467 }
4471 {
4475 {
4477 {
4480 }
4481 else
4485 }
4486 }
4488 /* Write out needed type info variables. We have to be careful
4489 looping through unemitted decls, because emit_tinfo_decl may
4490 cause other variables to be needed. New elements will be
4491 appended, and we remove from the vector those that actually
4492 get emitted. */
4496 {
4499 }
4501 /* The list of objects with static storage duration is built up
4502 in reverse order. We clear STATIC_AGGREGATES so that any new
4503 aggregates added during the initialization of these will be
4504 initialized in the correct order when we next come around the
4505 loop. */
4509 {
4510 /* We need to start a new initialization function each time
4511 through the loop. That's because we need to know which
4512 vtables have been referenced, and TREE_SYMBOL_REFERENCED
4513 isn't computed until a function is finished, and written
4514 out. That's a deficiency in the back end. When this is
4515 fixed, these initialization functions could all become
4516 inline, with resulting performance improvements. */
4517 tree ssdf_body;
4519 /* Set the line and file, so that it is obviously not from
4520 the source file. */
4524 /* Make sure the back end knows about all the variables. */
4527 /* First generate code to do all the initializations. */
4531 /* Then, generate code to do all the destructions. Do these
4532 in reverse order so that the most recently constructed
4533 variable is the first destroyed. If we're using
4534 __cxa_atexit, then we don't need to do this; functions
4535 were registered at initialization time to destroy the
4536 local statics. */
4538 {
4541 }
4542 else
4545 /* Finish up the static storage duration function for this
4546 round. */
4550 /* All those initializations and finalizations might cause
4551 us to need more inline functions, more template
4552 instantiations, etc. */
4554 ssdf_count++;
4555 /* ??? was: locus.line++; */
4556 }
4558 /* Now do the same for thread_local variables. */
4561 /* Go through the set of inline functions whose bodies have not
4562 been emitted yet. If out-of-line copies of these functions
4563 are required, emit them. */
4565 {
4566 /* Does it need synthesizing? */
4569 {
4570 /* Even though we're already at the top-level, we push
4571 there again. That way, when we pop back a few lines
4572 hence, all of our state is restored. Otherwise,
4573 finish_function doesn't clean things up, and we end
4574 up with CURRENT_FUNCTION_DECL set. */
4576 /* The decl's location will mark where it was first
4577 needed. Save that so synthesize method can indicate
4578 where it was needed from, in case of error */
4583 }
4591 /* We lie to the back end, pretending that some functions
4592 are not defined when they really are. This keeps these
4593 functions from being put out unnecessarily. But, we must
4594 stop lying when the functions are referenced, or if they
4595 are not comdat since they need to be put out now. If
4596 DECL_INTERFACE_KNOWN, then we have already set
4597 DECL_EXTERNAL appropriately, so there's no need to check
4598 again, and we do not want to clear DECL_EXTERNAL if a
4599 previous call to import_export_decl set it.
4601 This is done in a separate for cycle, because if some
4602 deferred function is contained in another deferred
4603 function later in deferred_fns varray,
4604 rest_of_compilation would skip this function and we
4605 really cannot expand the same function twice. */
4610 {
4619 /* If we mark !DECL_EXTERNAL one of the symbols in some comdat
4620 group, we need to mark all symbols in the same comdat group
4621 that way. */
4628 }
4630 /* If we're going to need to write this function out, and
4631 there's already a body for it, create RTL for it now.
4632 (There might be no body if this is a method we haven't
4633 gotten around to synthesizing yet.) */
4638 {
4639 /* We will output the function; no longer consider it in this
4640 loop. */
4642 /* Generate RTL for this function now that we know we
4643 need it. */
4645 /* If we're compiling -fsyntax-only pretend that this
4646 function has been written out so that we don't try to
4647 expand it again. */
4651 }
4652 }
4657 /* Static data members are just like namespace-scope globals. */
4659 {
4661 /* Don't write it out if we haven't seen a definition. */
4665 /* If this static data member is needed, provide it to the
4666 back end. */
4669 }
4675 retries++;
4676 }
4679 /* All used inline functions must have a definition at this point. */
4681 {
4684 /* If the definition actually was available here, then the
4685 fact that the function was not defined merely represents
4686 that for some reason (use of a template repository,
4687 #pragma interface, etc.) we decided not to emit the
4688 definition here. */
4690 /* Don't complain if the template was defined. */
4694 {
4696 /* Avoid a duplicate warning from check_global_declaration_1. */
4698 }
4699 }
4701 /* So must decls that use a type with no linkage. */
4707 /* Then, do the Objective-C stuff. This is where all the
4708 Objective-C module stuff gets generated (symtab,
4709 class/protocol/selector lists etc). This must be done after C++
4710 templates, destructors etc. so that selectors used in C++
4711 templates are properly allocated. */
4715 /* We give C linkage to static constructors and destructors. */
4718 /* Generate initialization and destruction functions for all
4719 priorities for which they are required. */
4722 generate_ctor_and_dtor_functions_for_priority,
4725 /* If this is obj-c++ and we need a static init, call
4726 generate_ctor_or_dtor_function. */
4730 /* We're done with the splay-tree now. */
4734 /* Generate any missing aliases. */
4737 /* We're done with static constructors, so we can go back to "C++"
4738 linkage now. */
4741 /* Collect candidates for Java hidden aliases. */
4748 {
4752 }
4757 {
4758 /* Generate the special constructor initialization function that
4759 calls __VLTRegisterPairs, and give it a very high
4760 initialization priority. This must be done after
4761 finalize_compilation_unit so that we have accurate
4762 information about which vtable will actually be emitted. */
4764 }
4769 /* Now, issue warnings about static, but not defined, functions,
4770 etc., and emit debugging information. */
4773 {
4778 }
4782 /* Generate hidden aliases for Java. */
4784 {
4787 }
4791 /* The entire file is now complete. If requested, dump everything
4792 to a file. */
4796 {
4799 }
4802 #ifdef ENABLE_CHECKING
4807 }
4809 /* FN is an OFFSET_REF, DOTSTAR_EXPR or MEMBER_REF indicating the
4810 function to call in parse-tree form; it has not yet been
4811 semantically analyzed. ARGS are the arguments to the function.
4812 They have already been semantically analyzed. This may change
4813 ARGS. */
4815 tree
4817 tsubst_flags_t complain)
4818 {
4819 tree orig_fn;
4821 tree expr;
4822 tree object;
4828 {
4837 /* Transform the arguments and add the implicit "this"
4838 parameter. That must be done before the FN is transformed
4839 because we depend on the form of FN. */
4843 {
4847 }
4848 /* Now that the arguments are done, transform FN. */
4850 }
4852 /* A qualified name corresponding to a bound pointer-to-member is
4853 represented as an OFFSET_REF:
4855 struct B { void g(); };
4856 void (B::*p)();
4857 void B::g() { (this->*p)(); } */
4859 {
4863 complain);
4865 }
4869 else
4878 }
4881 void
4883 {
4888 {
4892 {
4895 }
4896 }
4897 }
4899 /* Return true if function DECL can be inlined. This is used to force
4900 instantiation of methods that might be interesting for inlining. */
4901 bool
4903 {
4909 /* When optimizing, we might inline everything when flatten
4910 attribute or heuristics inlining for size or autoinlining
4911 is used. */
4913 }
4915 /* Mark DECL (either a _DECL or a BASELINK) as "used" in the program.
4916 If DECL is a specialization or implicitly declared class member,
4917 generate the actual definition. Return false if something goes
4918 wrong, true otherwise. */
4920 bool
4922 {
4923 /* If DECL is a BASELINK for a single function, then treat it just
4924 like the DECL for the function. Otherwise, if the BASELINK is
4925 for an overloaded function, we don't know which function was
4926 actually used until after overload resolution. */
4928 {
4933 }
4935 /* Set TREE_USED for the benefit of -Wunused. */
4940 /* Mark enumeration types as used. */
4949 {
4951 {
4954 {
4955 /* We mark a lambda conversion op as deleted if we can't
4956 generate it properly; see maybe_add_lambda_conv_op. */
4960 }
4961 }
4963 {
4967 }
4969 }
4975 /* We can only check DECL_ODR_USED on variables or functions with
4976 DECL_LANG_SPECIFIC set, and these are also the only decls that we
4977 might need special handling for. */
4981 {
4983 {
4987 }
4989 }
4991 /* We only want to do this processing once. We don't need to keep trying
4992 to instantiate inline templates, because unit-at-a-time will make sure
4993 we get them compiled before functions that want to inline them. */
4997 /* If within finish_function, defer the rest until that function
4998 finishes, otherwise it might recurse. */
5000 {
5003 }
5005 /* Normally, we can wait until instantiation-time to synthesize DECL.
5006 However, if DECL is a static data member initialized with a constant
5007 or a constexpr function, we need it right now because a reference to
5008 such a data member or a call to such function is not value-dependent.
5009 For a function that uses auto in the return type, we need to instantiate
5010 it to find out its type. For OpenMP user defined reductions, we need
5011 them instantiated for reduction clauses which inline them by hand
5012 directly. */
5021 {
5022 /* Instantiating a function will result in garbage collection. We
5023 must treat this situation as if we were within the body of a
5024 function so as to avoid collecting live data only referenced from
5025 the stack (such as overload resolution candidates). */
5030 }
5035 /* Check this too in case we're within instantiate_non_dependent_expr. */
5042 /* If we don't need a value, then we don't need to synthesize DECL. */
5050 /* DR 757: A type without linkage shall not be used as the type of a
5051 variable or function with linkage, unless
5052 o the variable or function has extern "C" linkage (7.5 [dcl.link]), or
5053 o the variable or function is not used (3.2 [basic.def.odr]) or is
5054 defined in the same translation unit. */
5061 {
5063 /* There's no way to define a local extern, and adding it to
5064 the vector interferes with GC, so give an error now. */
5066 else
5068 }
5072 /* Remember it, so we can check it was defined. */
5075 /* Is it a synthesized method that needs to be synthesized? */
5079 /* A function defaulted outside the class is synthesized either by
5080 cp_finish_decl or instantiate_decl. */
5083 {
5084 /* Defer virtual destructors so that thunks get the right
5085 linkage. */
5087 {
5090 }
5092 /* Remember the current location for a function we will end up
5093 synthesizing. Then we can inform the user where it was
5094 required in the case of error. */
5097 /* Synthesizing an implicitly defined member function will result in
5098 garbage collection. We must treat this situation as if we were
5099 within the body of a function so as to avoid collecting live data
5100 on the stack (such as overload resolution candidates).
5102 We could just let cp_write_global_declarations handle synthesizing
5103 this function by adding it to deferred_fns, but doing
5104 it at the use site produces better error messages. */
5108 /* If this is a synthesized method we don't need to
5109 do the instantiation test below. */
5110 }
5115 /* If this is a function or variable that is an instance of some
5116 template, we now know that we will need to actually do the
5117 instantiation. We check that DECL is not an explicit
5118 instantiation because that is not checked in instantiate_decl.
5120 We put off instantiating functions in order to improve compile
5121 times. Maintaining a stack of active functions is expensive,
5122 and the inliner knows to instantiate any functions it might
5123 need. Therefore, we always try to defer instantiation. */
5124 {
5129 }
5132 }
5134 bool
5136 {
5138 }
5140 tree
5142 {
5144 }
5146 tree
5148 {
5149 tree fn;
5157 }