Don't produce "comparison is always (true|false)" warnings when the
comparison itself is a constant expression. Fixes PR7536.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@126057 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 2cddac5..5566654 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -2581,7 +2581,11 @@
// We don't do anything special if this isn't an unsigned integral
// comparison: we're only interested in integral comparisons, and
// signed comparisons only happen in cases we don't care to warn about.
- if (!T->hasUnsignedIntegerRepresentation())
+ //
+ // We also don't care about value-dependent expressions or expressions
+ // whose result is a constant.
+ if (!T->hasUnsignedIntegerRepresentation()
+ || E->isValueDependent() || E->isIntegerConstantExpr(S.Context))
return AnalyzeImpConvsInComparison(S, E);
Expr *lex = E->getLHS()->IgnoreParenImpCasts();
diff --git a/test/SemaCXX/compare.cpp b/test/SemaCXX/compare.cpp
index ebecc06..ca8af21 100644
--- a/test/SemaCXX/compare.cpp
+++ b/test/SemaCXX/compare.cpp
@@ -206,3 +206,9 @@
if (vp < 0) { }
if (test1 < e) { } // expected-error{{comparison between pointer and integer}}
}
+
+// PR7536
+static const unsigned int kMax = 0;
+int pr7536() {
+ return (kMax > 0);
+}
diff --git a/test/SemaCXX/type-dependent-exprs.cpp b/test/SemaCXX/type-dependent-exprs.cpp
index 37d7cee..398c3cb 100644
--- a/test/SemaCXX/type-dependent-exprs.cpp
+++ b/test/SemaCXX/type-dependent-exprs.cpp
@@ -26,10 +26,10 @@
// This one entered into an infinite loop.
template <unsigned long N>
void rdar8520617() {
- if (N > 1) { } // expected-warning {{comparison of 0 > unsigned expression is always false}}
+ if (N > 1) { }
}
int f2() {
- rdar8520617<0>(); // expected-note {{in instantiation}}
+ rdar8520617<0>();
}