Fix isIntegerConstantExpr eval of __builtin_offsetof to return result

with correct width.
 - PR2728.

Also, fix PR2727 test case.

llvm-svn: 55493

1 files changed, 1 insertions, 0 deletions

diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index 49c76a89d86..1410f7e05ca 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -814,6 +814,7 @@ bool Expr::isIntegerConstantExpr(llvm::APSInt &Result, ASTContext &Ctx,
       Result = ~Result;
       break;
     case UnaryOperator::OffsetOf:
+      Result.zextOrTrunc(static_cast<uint32_t>(Ctx.getTypeSize(getType())));
       Result = Exp->evaluateOffsetOf(Ctx);
     }
     break;