[sema] Fix infinite loop when using a boolean value as designated initializer.

For designated indices use the max array size type bitwidth, not the bitwidth of the index value itself.
rdar://21942503

llvm-svn: 243343

clang/lib/Sema/SemaInit.cpp

@@ -2372,14 +2372,12 @@ InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
       return true;
     }
   } else {
-    // Make sure the bit-widths and signedness match.
-    if (DesignatedStartIndex.getBitWidth() > DesignatedEndIndex.getBitWidth())
-      DesignatedEndIndex
-        = DesignatedEndIndex.extend(DesignatedStartIndex.getBitWidth());
-    else if (DesignatedStartIndex.getBitWidth() <
-             DesignatedEndIndex.getBitWidth())
-      DesignatedStartIndex
-        = DesignatedStartIndex.extend(DesignatedEndIndex.getBitWidth());
+    unsigned DesignatedIndexBitWidth =
+      ConstantArrayType::getMaxSizeBits(SemaRef.Context);
+    DesignatedStartIndex =
+      DesignatedStartIndex.extOrTrunc(DesignatedIndexBitWidth);
+    DesignatedEndIndex =
+      DesignatedEndIndex.extOrTrunc(DesignatedIndexBitWidth);
     DesignatedStartIndex.setIsUnsigned(true);
     DesignatedEndIndex.setIsUnsigned(true);
   }

clang/test/CodeGenObjCXX/designated-initializers.mm

@@ -0,0 +1,36 @@
+// RUN: %clang_cc1 -triple arm64 %s -verify -emit-llvm -o - | FileCheck %s
+// expected-no-diagnostics
+
+// Make sure we don't enter an infinite loop (rdar://21942503)
+
+int vals1[] = {
+  [__objc_yes] = 1,
+  [__objc_no] = 2
+};
+// CHECK: @vals1 = global [2 x i32] [i32 2, i32 1]
+
+int vals2[] = {
+  [true] = 3,
+  [false] = 4
+};
+// CHECK: @vals2 = global [2 x i32] [i32 4, i32 3]
+
+int vals3[] = {
+  [false] = 1,
+  [true] = 2,
+  5
+};
+// CHECK: @vals3 = global [3 x i32] [i32 1, i32 2, i32 5]
+
+int vals4[2] = {
+  [true] = 5,
+  [false] = 6
+};
+// CHECK: @vals4 = global [2 x i32] [i32 6, i32 5]
+
+int vals5[3] = {
+  [false] = 1,
+  [true] = 2,
+  6
+};
+// CHECK: @vals5 = global [3 x i32] [i32 1, i32 2, i32 6]