Emit calls to objc_unsafeClaimAutoreleasedReturnValue when

reclaiming a call result in order to ignore it or assign it
to an __unsafe_unretained variable.  This avoids adding
an unwanted retain/release pair when the return value is
not actually returned autoreleased (e.g. when it is returned
from a nonatomic getter or a typical collection accessor).

This runtime function is only available on the latest Apple
OS releases; the backwards-compatibility story is that you
don't get the optimization unless your deployment target is
recent enough.  Sorry.

rdar://20530049

llvm-svn: 258962

1 files changed, 6 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 47c7ab2..fa1ceeb 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -2807,19 +2807,25 @@ public:
   llvm::Value *EmitARCAutoreleaseReturnValue(llvm::Value *value);
   llvm::Value *EmitARCRetainAutoreleaseReturnValue(llvm::Value *value);
   llvm::Value *EmitARCRetainAutoreleasedReturnValue(llvm::Value *value);
+  llvm::Value *EmitARCUnsafeClaimAutoreleasedReturnValue(llvm::Value *value);
 
   std::pair<LValue,llvm::Value*>
   EmitARCStoreAutoreleasing(const BinaryOperator *e);
   std::pair<LValue,llvm::Value*>
   EmitARCStoreStrong(const BinaryOperator *e, bool ignored);
+  std::pair<LValue,llvm::Value*>
+  EmitARCStoreUnsafeUnretained(const BinaryOperator *e, bool ignored);
 
   llvm::Value *EmitObjCThrowOperand(const Expr *expr);
   llvm::Value *EmitObjCConsumeObject(QualType T, llvm::Value *Ptr);
   llvm::Value *EmitObjCExtendObjectLifetime(QualType T, llvm::Value *Ptr);
 
   llvm::Value *EmitARCExtendBlockObject(const Expr *expr);
+  llvm::Value *EmitARCReclaimReturnedObject(const Expr *e,
+                                            bool allowUnsafeClaim);
   llvm::Value *EmitARCRetainScalarExpr(const Expr *expr);
   llvm::Value *EmitARCRetainAutoreleaseScalarExpr(const Expr *expr);
+  llvm::Value *EmitARCUnsafeUnretainedScalarExpr(const Expr *expr);
 
   void EmitARCIntrinsicUse(ArrayRef<llvm::Value*> values);