diff options
Diffstat (limited to 'lib/Sema/SemaExprObjC.cpp')
| -rw-r--r-- | lib/Sema/SemaExprObjC.cpp | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/lib/Sema/SemaExprObjC.cpp b/lib/Sema/SemaExprObjC.cpp index 17a7401d65..fa51098f1a 100644 --- a/lib/Sema/SemaExprObjC.cpp +++ b/lib/Sema/SemaExprObjC.cpp @@ -1771,6 +1771,20 @@ Sema::CheckObjCARCConversion(SourceRange castRange, QualType castType, << castRange << castExpr->getSourceRange(); } +/// Look for an ObjCReclaimReturnedObject cast and destroy it. +static Expr *maybeUndoReclaimObject(Expr *e) { + // For now, we just undo operands that are *immediately* reclaim + // expressions, which prevents the vast majority of potential + // problems here. To catch them all, we'd need to rebuild arbitrary + // value-propagating subexpressions --- we can't reliably rebuild + // in-place because of expression sharing. + if (ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(e)) + if (ice->getCastKind() == CK_ObjCReclaimReturnedObject) + return ice->getSubExpr(); + + return e; +} + ExprResult Sema::BuildObjCBridgedCast(SourceLocation LParenLoc, ObjCBridgeCastKind Kind, SourceLocation BridgeKeywordLoc, @@ -1815,6 +1829,9 @@ ExprResult Sema::BuildObjCBridgedCast(SourceLocation LParenLoc, // Okay: id -> CF switch (Kind) { case OBC_Bridge: + // Reclaiming a value that's going to be __bridge-casted to CF + // is very dangerous, so we don't do it. + SubExpr = maybeUndoReclaimObject(SubExpr); break; case OBC_BridgeRetained: |