[ObjC] Use empty Objective-C collection literal constants when

available.

Original patch by Douglas Gregor with minor modifications.

rdar://problem/20689633

llvm-svn: 300389

1 files changed, 12 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index 485d012b6e6..d65570fcef7 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -5980,9 +5980,21 @@ ExprResult Sema::MaybeBindToTemporary(Expr *E) {
       } else if (ObjCBoxedExpr *BoxedExpr = dyn_cast<ObjCBoxedExpr>(E)) {
         D = BoxedExpr->getBoxingMethod();
       } else if (ObjCArrayLiteral *ArrayLit = dyn_cast<ObjCArrayLiteral>(E)) {
+        // Don't do reclaims if we're using the zero-element array
+        // constant.
+        if (ArrayLit->getNumElements() == 0 &&
+            Context.getLangOpts().ObjCRuntime.hasEmptyCollections())
+          return E;
+
         D = ArrayLit->getArrayWithObjectsMethod();
       } else if (ObjCDictionaryLiteral *DictLit
                                         = dyn_cast<ObjCDictionaryLiteral>(E)) {
+        // Don't do reclaims if we're using the zero-element dictionary
+        // constant.
+        if (DictLit->getNumElements() == 0 &&
+            Context.getLangOpts().ObjCRuntime.hasEmptyCollections())
+          return E;
+
         D = DictLit->getDictWithObjectsMethod();
       }