Thread safety analysis: check for LOCKABLE attribute on base classes.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@156175 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index 3706bb8..ba1e699 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -14,6 +14,7 @@
 #include "clang/Sema/SemaInternal.h"
 #include "TargetAttributesSema.h"
 #include "clang/AST/ASTContext.h"
+#include "clang/AST/CXXInheritance.h"
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/DeclTemplate.h"
 #include "clang/AST/DeclObjC.h"
@@ -298,6 +299,16 @@
   return 0;
 }
 
+
+bool checkBaseClassIsLockableCallback(const CXXBaseSpecifier *Specifier,
+                                      CXXBasePath &Path, void *UserData) {
+  const RecordType *RT = Specifier->getType()->getAs<RecordType>();
+  if (RT->getDecl()->getAttr<LockableAttr>())
+    return true;
+  return false;
+}
+
+
 /// \brief Thread Safety Analysis: Checks that the passed in RecordType
 /// resolves to a lockable object.
 static void checkForLockableRecord(Sema &S, Decl *D, const AttributeList &Attr,
@@ -320,12 +331,20 @@
   if (threadSafetyCheckIsSmartPointer(S, RT))
     return;
 
-  // Warn if the type is not lockable.
-  if (!RT->getDecl()->getAttr<LockableAttr>()) {
-    S.Diag(Attr.getLoc(), diag::warn_thread_attribute_argument_not_lockable)
-      << Attr.getName() << Ty.getAsString();
+  // Check if the type is lockable.
+  RecordDecl *RD = RT->getDecl();
+  if (RD->getAttr<LockableAttr>())
     return;
+
+  // Else check if any base classes are lockable.
+  if (CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) {
+    CXXBasePaths BPaths(false, false);
+    if (CRD->lookupInBases(checkBaseClassIsLockableCallback, 0, BPaths))
+      return;
   }
+
+  S.Diag(Attr.getLoc(), diag::warn_thread_attribute_argument_not_lockable)
+    << Attr.getName() << Ty.getAsString();
 }
 
 /// \brief Thread Safety Analysis: Checks that all attribute arguments, starting
diff --git a/test/SemaCXX/warn-thread-safety-parsing.cpp b/test/SemaCXX/warn-thread-safety-parsing.cpp
index 62db3af..3f8a735 100644
--- a/test/SemaCXX/warn-thread-safety-parsing.cpp
+++ b/test/SemaCXX/warn-thread-safety-parsing.cpp
@@ -1319,6 +1319,8 @@
   Mutex mu_;
 };
 
+} // end namespace TestMultiDecl
+
 
 namespace NestedClassLateDecl {
 
@@ -1393,5 +1395,38 @@
 }
 
 
-} // end namespace TestMultiDecl
+namespace InheritanceTest {
+
+class LOCKABLE Base {
+ public:
+  void lock()   EXCLUSIVE_LOCK_FUNCTION();
+  void unlock() UNLOCK_FUNCTION();
+};
+
+class Base2 { };
+
+class Derived1 : public Base { };
+
+class Derived2 : public Base2, public Derived1 { };
+
+class Derived3 : public Base2 { };
+
+class Foo {
+  Derived1 mu1_;
+  Derived2 mu2_;
+  Derived3 mu3_;
+  int a GUARDED_BY(mu1_);
+  int b GUARDED_BY(mu2_);
+  int c GUARDED_BY(mu3_);  // \
+    // expected-warning {{'guarded_by' attribute requires arguments whose type is annotated with 'lockable' attribute; type here is 'class InheritanceTest::Derived3'}}
+
+  void foo() EXCLUSIVE_LOCKS_REQUIRED(mu1_, mu2_) {
+    a = 0;
+    b = 0;
+  }
+};
+
+}
+
+