The `-fwritable-strings' flag doesn't make the backing store strings of all
CFStrings writable.
The strings (both Unicode and ASCII) should reside in a read-only section. E.g.,
__TEXT,__cstring instead of __DATA,__data. This is done by making the global
variable created for the strings constant despite the value of that flag.
<rdar://problem/10657500>
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147845 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/cfstring.c b/test/CodeGen/cfstring.c
index 1f0977f..9d98b56 100644
--- a/test/CodeGen/cfstring.c
+++ b/test/CodeGen/cfstring.c
@@ -1,4 +1,14 @@
// RUN: %clang_cc1 -emit-llvm %s -o %t
+
+// <rdar://problem/10657500>: Check that the backing store of CFStrings are
+// constant with the -fwritable-strings flag.
+//
+// RUN: %clang_cc1 -fwritable-strings -emit-llvm %s -o - | FileCheck %s
+//
+// CHECK: @.str = linker_private unnamed_addr constant [14 x i8] c"Hello, World!\00", align 1
+// CHECK: @.str1 = linker_private unnamed_addr constant [7 x i8] c"yo joe\00", align 1
+// CHECK: @.str3 = linker_private unnamed_addr constant [16 x i8] c"Goodbye, World!\00", align 1
+
#define CFSTR __builtin___CFStringMakeConstantString
void f() {