diff options
| author | Richard Smith <richard-llvm@metafoo.co.uk> | 2013-02-13 21:18:23 +0000 |
|---|---|---|
| committer | Richard Smith <richard-llvm@metafoo.co.uk> | 2013-02-13 21:18:23 +0000 |
| commit | c764830bdb6de82baed068889096bd3e52d4cbda (patch) | |
| tree | 73a7173f5bd2dcbb43b3950276f7e8f429a39a17 /lib/CodeGen/CGExprScalar.cpp | |
| parent | a03ab10f0e4d888139b3b694dd55d176982f72a4 (diff) | |
ubsan: Add checking for invalid downcasts. Per [expr.static.cast]p2 and p11,
base-to-derived casts have undefined behavior if the object is not actually an
instance of the derived type.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175078 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/CGExprScalar.cpp')
| -rw-r--r-- | lib/CodeGen/CGExprScalar.cpp | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp index 49494be901..7b86c04e8a 100644 --- a/lib/CodeGen/CGExprScalar.cpp +++ b/lib/CodeGen/CGExprScalar.cpp @@ -1220,7 +1220,15 @@ Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) { const CXXRecordDecl *DerivedClassDecl = DestTy->getPointeeCXXRecordDecl(); assert(DerivedClassDecl && "BaseToDerived arg isn't a C++ object pointer!"); - return CGF.GetAddressOfDerivedClass(Visit(E), DerivedClassDecl, + llvm::Value *V = Visit(E); + + // C++11 [expr.static.cast]p11: Behavior is undefined if a downcast is + // performed and the object is not of the derived type. + if (CGF.SanitizePerformTypeCheck) + CGF.EmitTypeCheck(CodeGenFunction::TCK_DowncastPointer, CE->getExprLoc(), + V, DestTy->getPointeeType()); + + return CGF.GetAddressOfDerivedClass(V, DerivedClassDecl, CE->path_begin(), CE->path_end(), ShouldNullCheckClassCastValue(CE)); } |