[clang-tidy] Fix more enum declaration cases in misc-unused-using-decls check.

Summary: Fix PR28350.

Reviewers: alexfh

Subscribers: aaron.ballman, Eugene.Zelenko, cfe-commits

Differential Revision: http://reviews.llvm.org/D21833

llvm-svn: 274496

2 files changed, 18 insertions, 9 deletions

diff --git a/clang-tools-extra/clang-tidy/misc/UnusedUsingDeclsCheck.cpp b/clang-tools-extra/clang-tidy/misc/UnusedUsingDeclsCheck.cpp
index 30ff7b80a6c..8c9859c6792 100644
--- a/clang-tools-extra/clang-tidy/misc/UnusedUsingDeclsCheck.cpp
+++ b/clang-tools-extra/clang-tidy/misc/UnusedUsingDeclsCheck.cpp
@@ -31,6 +31,7 @@ static bool ShouldCheckDecl(const Decl *TargetDecl) {
 void UnusedUsingDeclsCheck::registerMatchers(MatchFinder *Finder) {
   Finder->addMatcher(usingDecl(isExpansionInMainFile()).bind("using"), this);
   auto DeclMatcher = hasDeclaration(namedDecl().bind("used"));
+  Finder->addMatcher(loc(enumType(DeclMatcher)), this);
   Finder->addMatcher(loc(recordType(DeclMatcher)), this);
   Finder->addMatcher(loc(templateSpecializationType(DeclMatcher)), this);
   Finder->addMatcher(declRefExpr().bind("used"), this);
@@ -94,6 +95,8 @@ void UnusedUsingDeclsCheck::check(const MatchFinder::MatchResult &Result) {
       removeFromFoundDecls(VD);
     } else if (const auto *ECD = dyn_cast<EnumConstantDecl>(DRE->getDecl())) {
       removeFromFoundDecls(ECD);
+      if (const auto *ET = ECD->getType()->getAs<EnumType>())
+        removeFromFoundDecls(ET->getDecl());
     }
   }
   // Check the uninstantiated template function usage.
diff --git a/clang-tools-extra/test/clang-tidy/misc-unused-using-decls.cpp b/clang-tools-extra/test/clang-tidy/misc-unused-using-decls.cpp
index a5399fa5545..618a9f661f9 100644
--- a/clang-tools-extra/test/clang-tidy/misc-unused-using-decls.cpp
+++ b/clang-tools-extra/test/clang-tidy/misc-unused-using-decls.cpp
@@ -44,11 +44,13 @@ public:
 extern ostream cout;
 ostream &endl(ostream &os);
 
-enum Color {
-  Green,
-  Red,
-  Yellow
-};
+enum Color1 { Green };
+
+enum Color2 { Red };
+
+enum Color3 { Yellow };
+
+enum Color4 { Blue };
 
 }  // namespace n
 
@@ -126,11 +128,13 @@ void IgnoreFunctionScope() {
 using n::H;
 }
 
-using n::Color;
-// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: using decl 'Color' is unused
+using n::Color1;
+// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: using decl 'Color1' is unused
 using n::Green;
 // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: using decl 'Green' is unused
-using n::Red;
+using n::Color2;
+using n::Color3;
+using n::Blue;
 
 // ----- Usages -----
 void f(B b);
@@ -144,5 +148,7 @@ void g() {
   UsedFunc();
   UsedTemplateFunc<int>();
   cout << endl;
-  int t = Red;
+  Color2 color2;
+  int t1 = Color3::Yellow;
+  int t2 = Blue;
 }