Thread Safety Analysis: warnings for attributes without arguments

Summary:
When thread safety annotations are used without capability arguments,
they are assumed to apply to `this` instead. So we warn when either
`this` doesn't exist, or the class is not a capability type.

This is based on earlier work by Josh Gao that was committed in r310403,
but reverted in r310698 because it didn't properly work in template
classes. See also D36237.

The solution is not to go via the QualType of `this`, which is then a
template type, hence the attributes are not known because it could be
specialized. Instead we look directly at the class in which we are
contained.

Additionally I grouped two of the warnings together. There are two
issues here: the existence of `this`, which requires us to be a
non-static member function, and the appropriate annotation on the class
we are contained in. So we don't distinguish between not being in a
class and being static, because in both cases we don't have `this`.

Fixes PR38399.

Reviewers: aaron.ballman, delesley, jmgao, rtrieu

Reviewed By: delesley

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D51901

llvm-svn: 342605

1 files changed, 12 insertions, 2 deletions

diff --git a/clang/test/Sema/attr-capabilities.c b/clang/test/Sema/attr-capabilities.c
index 21cbae9e609..8bfc4a50654 100644
--- a/clang/test/Sema/attr-capabilities.c
+++ b/clang/test/Sema/attr-capabilities.c
@@ -37,15 +37,25 @@ void Func6(void) __attribute__((requires_shared_capability(BadCapability))) {}
 void Func7(void) __attribute__((assert_capability(GUI))) {}
 void Func8(void) __attribute__((assert_shared_capability(GUI))) {}
 
+void Func9(void) __attribute__((assert_capability())) {} // expected-warning {{'assert_capability' attribute without capability arguments can only be applied to non-static methods of a class}}
+void Func10(void) __attribute__((assert_shared_capability())) {} // expected-warning {{'assert_shared_capability' attribute without capability arguments can only be applied to non-static methods of a class}}
+
 void Func11(void) __attribute__((acquire_capability(GUI))) {}
 void Func12(void) __attribute__((acquire_shared_capability(GUI))) {}
 
+void Func13(void) __attribute__((acquire_capability())) {} // expected-warning {{'acquire_capability' attribute without capability arguments can only be applied to non-static methods of a class}}
+void Func14(void) __attribute__((acquire_shared_capability())) {} // expected-warning {{'acquire_shared_capability' attribute without capability arguments can only be applied to non-static methods of a class}}
+
 void Func15(void) __attribute__((release_capability(GUI))) {}
 void Func16(void) __attribute__((release_shared_capability(GUI))) {}
 void Func17(void) __attribute__((release_generic_capability(GUI))) {}
 
-void Func21(void) __attribute__((try_acquire_capability(1))) {}
-void Func22(void) __attribute__((try_acquire_shared_capability(1))) {}
+void Func18(void) __attribute__((release_capability())) {} // expected-warning {{'release_capability' attribute without capability arguments can only be applied to non-static methods of a class}}
+void Func19(void) __attribute__((release_shared_capability())) {} // expected-warning {{'release_shared_capability' attribute without capability arguments can only be applied to non-static methods of a class}}
+void Func20(void) __attribute__((release_generic_capability())) {} // expected-warning {{'release_generic_capability' attribute without capability arguments can only be applied to non-static methods of a class}}
+
+void Func21(void) __attribute__((try_acquire_capability(1))) {} // expected-warning {{'try_acquire_capability' attribute without capability arguments can only be applied to non-static methods of a class}}
+void Func22(void) __attribute__((try_acquire_shared_capability(1))) {} // expected-warning {{'try_acquire_shared_capability' attribute without capability arguments can only be applied to non-static methods of a class}}
 
 void Func23(void) __attribute__((try_acquire_capability(1, GUI))) {}
 void Func24(void) __attribute__((try_acquire_shared_capability(1, GUI))) {}