Type of a conditional expression with two distinct objective-c
class pointer is the most derived common class of the two.
This is <rdar://problem/7334235>.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@85337 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 6c63c52..eb6d392 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -3846,6 +3846,28 @@
return false;
}
+/// areCommonBaseCompatible - Returns common base class of the two classes if
+/// one found. Note that this is O'2 algorithm. But it will be called as the
+/// last type comparison in a ?-exp of ObjC pointer types before a
+/// warning is issued. So, its invokation is extremely rare.
+QualType ASTContext::areCommonBaseCompatible(
+ const ObjCObjectPointerType *LHSOPT,
+ const ObjCObjectPointerType *RHSOPT) {
+ const ObjCInterfaceType* LHS = LHSOPT->getInterfaceType();
+ const ObjCInterfaceType* RHS = RHSOPT->getInterfaceType();
+ if (!LHS || !RHS)
+ return QualType();
+
+ while (const ObjCInterfaceDecl *LHSIDecl = LHS->getDecl()->getSuperClass()) {
+ QualType LHSTy = getObjCInterfaceType(LHSIDecl);
+ LHS = LHSTy->getAs<ObjCInterfaceType>();
+ if (canAssignObjCInterfaces(LHS, RHS))
+ return getObjCObjectPointerType(LHSTy);
+ }
+
+ return QualType();
+}
+
bool ASTContext::canAssignObjCInterfaces(const ObjCInterfaceType *LHS,
const ObjCInterfaceType *RHS) {
// Verify that the base decls are compatible: the RHS must be a subclass of