unexpected-flag-enumerator-value: Don't warn for enums with 0

0 is a valid and very common flag

2 files changed, 13 insertions, 5 deletions

diff --git a/src/checks/manuallevel/unexpected-flag-enumerator-value.cpp b/src/checks/manuallevel/unexpected-flag-enumerator-value.cpp
index ad3dc39f..d48be74e 100644
--- a/src/checks/manuallevel/unexpected-flag-enumerator-value.cpp
+++ b/src/checks/manuallevel/unexpected-flag-enumerator-value.cpp
@@ -116,15 +116,14 @@ void UnexpectedFlagEnumeratorValue::VisitDecl(clang::Decl *decl)
     const SmallVector<EnumConstantDecl*, 16> enumerators = getEnumerators(enDecl);
 
     auto flagEnum = isFlagEnum(enumerators);
-    if (!flagEnum.isFlagEnum) {
+    if (!flagEnum.isFlagEnum)
         return;
-    }
 
     for (EnumConstantDecl* enumerator : enumerators) {
-        if (!enumerator->getInitVal().isPowerOf2()) {
-            if (isIntentionallyNotPowerOf2(enumerator)) {
+        const auto &initVal = enumerator->getInitVal();
+        if (!initVal.isPowerOf2() && !initVal.isNullValue()){
+            if (isIntentionallyNotPowerOf2(enumerator))
                 continue;
-            }
             const auto value = enumerator->getInitVal().getLimitedValue();
             Expr *initExpr = enumerator->getInitExpr();
             emitWarning(initExpr ? initExpr->getBeginLoc() : enumerator->getBeginLoc(), "Unexpected non power-of-2 enumerator value: " + std::to_string(value));
diff --git a/tests/unexpected-flag-enumerator-value/main.cpp b/tests/unexpected-flag-enumerator-value/main.cpp
index db070983..bb2d19f4 100644
--- a/tests/unexpected-flag-enumerator-value/main.cpp
+++ b/tests/unexpected-flag-enumerator-value/main.cpp
@@ -63,3 +63,12 @@ enum WithMasks
     V8 = 8,
     Mask = 0x0000FFFF
 };
+
+
+enum class WithZero {
+    Zero = 0,
+    Foo = 1,
+    Bar = 2,
+    Four = 4,
+    Eight = 8,
+};