[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

1 files changed, 6 insertions, 8 deletions

diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index 25d091f1d8c..ed569635848 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/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);
   }