[Sema] Handle transparent_union attributes in C mode only
This commit marks the transparent_union attributes as C only because clang
doesn't support them in C++ mode. Prior to this commit, clang still tried to
verify these attributes in C++, leading to crashes when analyzing templated
transparent_union unions that have dependent field types. This commit ensures
that such crashes won't happen again.
As a result of this commit clang now displays a warning every time it encounters
a transparent_union attribute in C++ mode.
Differential Revision: https://reviews.llvm.org/D25308
llvm-svn: 283995
diff --git a/clang/test/SemaCXX/attr-gnu.cpp b/clang/test/SemaCXX/attr-gnu.cpp
index b4e9f46..a553f0d 100644
--- a/clang/test/SemaCXX/attr-gnu.cpp
+++ b/clang/test/SemaCXX/attr-gnu.cpp
@@ -27,3 +27,19 @@
void test3() __attribute__((cf_unknown_transfer)) override {} // Ok, not known to GCC.
};
}
+
+template<typename T>
+union Tu { T b; } __attribute__((transparent_union)); // expected-warning {{'transparent_union' attribute ignored}}
+
+template<typename T>
+union Tu2 { int x; T b; } __attribute__((transparent_union)); // expected-warning {{'transparent_union' attribute ignored}}
+
+union Tu3 { int x; } __attribute((transparent_union)); // expected-warning {{'transparent_union' attribute ignored}}
+
+void tuTest1(Tu<int> u); // expected-note {{candidate function not viable: no known conversion from 'int' to 'Tu<int>' for 1st argument}}
+void tuTest2(Tu3 u); // expected-note {{candidate function not viable: no known conversion from 'int' to 'Tu3' for 1st argument}}
+void tu() {
+ int x = 2;
+ tuTest1(x); // expected-error {{no matching function for call to 'tuTest1'}}
+ tuTest2(x); // expected-error {{no matching function for call to 'tuTest2'}}
+}