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| author | Douglas Gregor <dgregor@apple.com> | 2015-07-07 03:58:54 +0000 |
|---|---|---|
| committer | Douglas Gregor <dgregor@apple.com> | 2015-07-07 03:58:54 +0000 |
| commit | 1ac1b63c9ca898e66aae9775cca6045082907b9a (patch) | |
| tree | b9196b185b0185c84e60f99881aaffd69f4da93d /clang/lib/Lex/PPMacroExpansion.cpp | |
| parent | ab209d83be5dadff4f17364a71f323b89e3c63f8 (diff) | |
| download | bcm5719-llvm-1ac1b63c9ca898e66aae9775cca6045082907b9a.tar.gz bcm5719-llvm-1ac1b63c9ca898e66aae9775cca6045082907b9a.zip | |
Implement variance for Objective-C type parameters.
Introduce co- and contra-variance for Objective-C type parameters,
which allows us to express that (for example) an NSArray is covariant
in its type parameter. This means that NSArray<NSMutableString *> * is
a subtype of NSArray<NSString *> *, which is expected of the immutable
Foundation collections.
Type parameters can be annotated with __covariant or __contravariant
to make them co- or contra-variant, respectively. This feature can be
detected by __has_feature(objc_generics_variance). Implements
rdar://problem/20217490.
llvm-svn: 241549
Diffstat (limited to 'clang/lib/Lex/PPMacroExpansion.cpp')
| -rw-r--r-- | clang/lib/Lex/PPMacroExpansion.cpp | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/clang/lib/Lex/PPMacroExpansion.cpp b/clang/lib/Lex/PPMacroExpansion.cpp index 6790908fe4b..64ce8c91825 100644 --- a/clang/lib/Lex/PPMacroExpansion.cpp +++ b/clang/lib/Lex/PPMacroExpansion.cpp @@ -1108,6 +1108,7 @@ static bool HasFeature(const Preprocessor &PP, const IdentifierInfo *II) { .Case("objc_bridge_id", true) .Case("objc_bridge_id_on_typedefs", true) .Case("objc_generics", LangOpts.ObjC2) + .Case("objc_generics_variance", LangOpts.ObjC2) // C11 features .Case("c_alignas", LangOpts.C11) .Case("c_alignof", LangOpts.C11) |
