diff options
author | James Y Knight <jyknight@google.com> | 2019-10-17 15:27:04 +0000 |
---|---|---|
committer | James Y Knight <jyknight@google.com> | 2019-10-17 15:27:04 +0000 |
commit | 3b8d539899d6651504edfbaaa2ea68eb9d7aa6ac (patch) | |
tree | cebec8b73d1d3ba1a8e41dfd889d75f437c2eb12 /lib | |
parent | b15c08d32c072399e59c388bbf6a814831a0bb92 (diff) | |
download | clang-3b8d539899d6651504edfbaaa2ea68eb9d7aa6ac.tar.gz |
[ObjC] Diagnose implicit type coercion from ObjC 'Class' to object
pointer types.
For example, in Objective-C mode, the initialization of 'x' in:
```
@implementation MyType
+ (void)someClassMethod {
MyType *x = self;
}
@end
```
is correctly diagnosed with an incompatible-pointer-types warning, but
in Objective-C++ mode, it is not diagnosed at all -- even though
incompatible pointer conversions generally become an error in C++.
This patch fixes that oversight, allowing implicit conversions
involving Class only to/from unqualified-id, and between qualified and
unqualified Class, where the protocols are compatible.
Note that this does change some behaviors in Objective-C, as well, as
shown by the modified tests.
Of particular note is that assignment from from 'Class<MyProtocol>' to
'id<MyProtocol>' now warns. (Despite appearances, those are not
compatible types. 'Class<MyProtocol>' is not expected to have instance
methods defined by 'MyProtocol', while 'id<MyProtocol>' is.)
Differential Revision: https://reviews.llvm.org/D67983
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@375125 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
-rw-r--r-- | lib/AST/ASTContext.cpp | 26 | ||||
-rw-r--r-- | lib/Sema/SemaExpr.cpp | 4 |
2 files changed, 19 insertions, 11 deletions
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp index 1a3bde00ee..cda51ec755 100644 --- a/lib/AST/ASTContext.cpp +++ b/lib/AST/ASTContext.cpp @@ -8025,14 +8025,15 @@ bool ASTContext::ObjCQualifiedClassTypesAreCompatible( bool ASTContext::ObjCQualifiedIdTypesAreCompatible( const ObjCObjectPointerType *lhs, const ObjCObjectPointerType *rhs, bool compare) { - // Allow id<P..> and an 'id' or void* type in all cases. - if (lhs->isVoidPointerType() || - lhs->isObjCIdType() || lhs->isObjCClassType()) - return true; - else if (rhs->isVoidPointerType() || - rhs->isObjCIdType() || rhs->isObjCClassType()) + // Allow id<P..> and an 'id' in all cases. + if (lhs->isObjCIdType() || rhs->isObjCIdType()) return true; + // Don't allow id<P..> to convert to Class or Class<P..> in either direction. + if (lhs->isObjCClassType() || lhs->isObjCQualifiedClassType() || + rhs->isObjCClassType() || rhs->isObjCQualifiedClassType()) + return false; + if (lhs->isObjCQualifiedIdType()) { if (rhs->qual_empty()) { // If the RHS is a unqualified interface pointer "NSString*", @@ -8142,9 +8143,8 @@ bool ASTContext::canAssignObjCInterfaces(const ObjCObjectPointerType *LHSOPT, const ObjCObjectType* LHS = LHSOPT->getObjectType(); const ObjCObjectType* RHS = RHSOPT->getObjectType(); - // If either type represents the built-in 'id' or 'Class' types, return true. - if (LHS->isObjCUnqualifiedIdOrClass() || - RHS->isObjCUnqualifiedIdOrClass()) + // If either type represents the built-in 'id' type, return true. + if (LHS->isObjCUnqualifiedId() || RHS->isObjCUnqualifiedId()) return true; // Function object that propagates a successful result or handles @@ -8162,14 +8162,22 @@ bool ASTContext::canAssignObjCInterfaces(const ObjCObjectPointerType *LHSOPT, LHSOPT->stripObjCKindOfTypeAndQuals(*this)); }; + // Casts from or to id<P> are allowed when the other side has compatible + // protocols. if (LHS->isObjCQualifiedId() || RHS->isObjCQualifiedId()) { return finish(ObjCQualifiedIdTypesAreCompatible(LHSOPT, RHSOPT, false)); } + // Verify protocol compatibility for casts from Class<P1> to Class<P2>. if (LHS->isObjCQualifiedClass() && RHS->isObjCQualifiedClass()) { return finish(ObjCQualifiedClassTypesAreCompatible(LHSOPT, RHSOPT)); } + // Casts from Class to Class<Foo>, or vice-versa, are allowed. + if (LHS->isObjCClass() && RHS->isObjCClass()) { + return true; + } + // If we have 2 user-defined types, fall into that path. if (LHS->getInterface() && RHS->getInterface()) { return finish(canAssignObjCInterfaces(LHS, RHS)); diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp index 6e3980275a..333983a430 100644 --- a/lib/Sema/SemaExpr.cpp +++ b/lib/Sema/SemaExpr.cpp @@ -10068,8 +10068,8 @@ static bool convertPointersToCompositeType(Sema &S, SourceLocation Loc, QualType T = S.FindCompositePointerType(Loc, LHS, RHS); if (T.isNull()) { - if ((LHSType->isPointerType() || LHSType->isMemberPointerType()) && - (RHSType->isPointerType() || RHSType->isMemberPointerType())) + if ((LHSType->isAnyPointerType() || LHSType->isMemberPointerType()) && + (RHSType->isAnyPointerType() || RHSType->isMemberPointerType())) diagnoseDistinctPointerComparison(S, Loc, LHS, RHS, /*isError*/true); else S.InvalidOperands(Loc, LHS, RHS); |