clang-tidy: [use-override] Remove 'override' if 'final' is also present.

Also, make warning more precise by distinguishing different cases.

llvm-svn: 210651

clang-tools-extra/clang-tidy/misc/UseOverride.cpp

@@ -61,14 +61,21 @@ void UseOverride::check(const MatchFinder::MatchResult &Result) {
       Method->isOutOfLine())
     return;
 
-  if ((Method->getAttr<clang::OverrideAttr>() != nullptr ||
-       Method->getAttr<clang::FinalAttr>() != nullptr) &&
-      !Method->isVirtualAsWritten())
+  bool HasVirtual = Method->isVirtualAsWritten();
+  bool HasOverride = Method->getAttr<OverrideAttr>();
+  bool HasFinal = Method->getAttr<FinalAttr>();
+
+  bool OnlyVirtualSpecified = HasVirtual && !HasOverride && !HasFinal;
+  unsigned KeywordCount = HasVirtual + HasOverride + HasFinal;
+
+  if (!OnlyVirtualSpecified && KeywordCount == 1)
     return; // Nothing to do.
 
   DiagnosticBuilder Diag =
       diag(Method->getLocation(),
-           "Prefer using 'override' or 'final' instead of 'virtual'");
+           OnlyVirtualSpecified
+               ? "Prefer using 'override' or 'final' instead of 'virtual'"
+               : "Use exactly one of 'virtual', 'override' and 'final'");
 
   CharSourceRange FileRange =
       Lexer::makeFileCharRange(CharSourceRange::getTokenRange(
@@ -85,8 +92,7 @@ void UseOverride::check(const MatchFinder::MatchResult &Result) {
                                               Result.Context->getLangOpts());
 
   // Add 'override' on inline declarations that don't already have it.
-  if (Method->getAttr<clang::OverrideAttr>() == nullptr &&
-      Method->getAttr<clang::FinalAttr>() == nullptr) {
+  if (!HasFinal && !HasOverride) {
     SourceLocation InsertLoc;
     StringRef ReplacementText = "override ";
 
@@ -120,6 +126,12 @@ void UseOverride::check(const MatchFinder::MatchResult &Result) {
     Diag << FixItHint::CreateInsertion(InsertLoc, ReplacementText);
   }
 
+  if (HasFinal && HasOverride) {
+    SourceLocation OverrideLoc = Method->getAttr<OverrideAttr>()->getLocation();
+    Diag << FixItHint::CreateRemoval(
+        CharSourceRange::getTokenRange(OverrideLoc, OverrideLoc));
+  }
+
   if (Method->isVirtualAsWritten()) {
     for (Token Tok : Tokens) {
       if (Tok.is(tok::raw_identifier) && GetText(Tok, Sources) == "virtual") {

clang-tools-extra/test/clang-tidy/use-override-fix.cpp

@@ -25,6 +25,8 @@ struct Base {
   virtual void j() const;
   virtual MustUseResultObject k();
   virtual bool l() MUST_USE_RESULT;
+
+  virtual void m();
 };
 
 struct SimpleCases : public Base {
@@ -54,6 +56,9 @@ public:
   // CHECK: {{^  MustUseResultObject k\(\) override;}}
   virtual bool l() MUST_USE_RESULT; // Has an explicit attribute
   // CHECK: {{^  bool l\(\) override MUST_USE_RESULT;}}
+
+  virtual void m() override final;
+  // CHECK: {{^  void m\(\) final;}}
 };
 
 void SimpleCases::i() {}
@@ -125,6 +130,9 @@ struct Macros : public Base {
 #define F virtual void f();
   F
   // CHECK: {{^  F}}
+
+  VIRTUAL void g() OVERRIDE final;
+  // CHECK: {{^  VIRTUAL void g\(\) final;}}
 };
 
 // Tests for templates.

clang-tools-extra/test/clang-tidy/use-override.cpp

@@ -7,6 +7,8 @@ struct Base {
   virtual void b();
   virtual void c();
   virtual void d();
+  virtual void e();
+  virtual void f();
 };
 
 struct SimpleCases : public Base {
@@ -15,11 +17,15 @@ public:
   // CHECK: :[[@LINE-1]]:11: warning: Prefer using 'override' or 'final' instead of 'virtual'
 
   void a();
-  // CHECK: :[[@LINE-1]]:8: warning: Prefer using
+  // CHECK: :[[@LINE-1]]:8: warning: Use exactly
   virtual void b();
   // CHECK: :[[@LINE-1]]:16: warning: Prefer using
-  void c() override;
+  virtual void c() override;
+  // CHECK: :[[@LINE-1]]:16: warning: Use exactly
+  void d() override final;
+  // CHECK: :[[@LINE-1]]:8: warning: Use exactly
+  void e() override;
   // CHECK-NOT: :[[@LINE-1]]:{{.*}} warning:
-  void d() final;
+  void f() final;
   // CHECK-NOT: :[[@LINE-1]]:{{.*}} warning:
 };