Fix -Wshift-count-negative. It didn't work if the right hand side

of the shift wasn't a constant integer expression, now it (hopefully)
does.

PR:		22059
llvm-svn: 233320

2 files changed, 7 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index c061e0610ed..6eac5b6a936 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -7769,7 +7769,7 @@ static void DiagnoseBadShiftValues(Sema& S, ExprResult &LHS, ExprResult &RHS,
   llvm::APSInt Right;
   // Check right/shifter operand
   if (RHS.get()->isValueDependent() ||
-      !RHS.get()->isIntegerConstantExpr(Right, S.Context))
+      !RHS.get()->EvaluateAsInt(Right, S.Context))
     return;
 
   if (Right.isNegative()) {
diff --git a/clang/test/Sema/warn-shift-negative.c b/clang/test/Sema/warn-shift-negative.c
new file mode 100644
index 00000000000..c65d66c1214
--- /dev/null
+++ b/clang/test/Sema/warn-shift-negative.c
@@ -0,0 +1,6 @@
+// RUN: %clang_cc1 -fsyntax-only -Wshift-count-negative -fblocks -verify %s
+
+int f(int a) {
+  const int i = -1;
+  return a << i; // expected-warning{{shift count is negative}}
+}