Consider zero-length array of structs when

computing ivar layouts for objc-gc.
Fixes // rdar://8800513

llvm-svn: 122762

2 files changed, 23 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/CGObjCMac.cpp b/clang/lib/CodeGen/CGObjCMac.cpp
index 66913c8ee28..2a27e919250 100644
--- a/clang/lib/CodeGen/CGObjCMac.cpp
+++ b/clang/lib/CodeGen/CGObjCMac.cpp
@@ -3681,7 +3681,7 @@ void CGObjCCommonMac::BuildAggrIvarLayout(const ObjCImplementationDecl *OI,
 
       assert(!FQT->isUnionType() &&
              "layout for array of unions not supported");
-      if (FQT->isRecordType()) {
+      if (FQT->isRecordType() && ElCount) {
         int OldIndex = IvarsInfo.size() - 1;
         int OldSkIndex = SkipIvars.size() -1;
 
diff --git a/clang/test/CodeGenObjC/ivar-layout-array0-struct.m b/clang/test/CodeGenObjC/ivar-layout-array0-struct.m
new file mode 100644
index 00000000000..4300db36415
--- /dev/null
+++ b/clang/test/CodeGenObjC/ivar-layout-array0-struct.m
@@ -0,0 +1,22 @@
+// RUN: %clang_cc1 -fobjc-gc -triple x86_64-apple-darwin -O0 -S %s -o %t-64.s
+// RUN: FileCheck -check-prefix LP64 --input-file=%t-64.s %s
+
+// rdar://8800513
+@interface NSObject {
+  id isa;
+}
+@end
+
+typedef struct {
+    id b;
+} st;
+
+@interface Test : NSObject {
+    int a;
+    st b[0];
+}
+@end
+
+@implementation Test @end
+// CHECK-LP64: L_OBJC_CLASS_NAME_4:
+// CHECK-LP64-NEXT: .asciz      "\001\020"