Handle value dependent LHS as well as RHS. Test both of these, they

don't seem to have been covered by our tests previously.

This should fix bootstrap failure.

llvm-svn: 126345

clang/lib/Sema/SemaExpr.cpp

@@ -6652,7 +6652,7 @@ static void DiagnoseBadShiftValues(Sema& S, Expr *&lex, Expr *&rex,
   // integers have defined behavior modulo one more than the maximum value
   // representable in the result type, so never warn for those.
   llvm::APSInt Left;
-  if (!lex->isIntegerConstantExpr(Left, S.Context) ||
+  if (lex->isValueDependent() || !lex->isIntegerConstantExpr(Left, S.Context) ||
       LHSTy->hasUnsignedIntegerRepresentation())
     return;
   llvm::APInt ResultBits =

clang/test/SemaCXX/shift.cpp

@@ -0,0 +1,14 @@
+// RUN: %clang_cc1 -Wall -Wshift-sign-overflow -ffreestanding -fsyntax-only -verify %s
+
+#include <limits.h>
+
+#define WORD_BIT (sizeof(int) * CHAR_BIT)
+
+template <int N> void f() {
+  (void)(N << 30); // expected-warning {{the promoted type of the shift expression is 'int'}}
+  (void)(30 << N); // expected-warning {{the promoted type of the shift expression is 'int'}}
+}
+
+void test() {
+  f<30>(); // expected-note {{instantiation}}
+}