Add support for arrays in performance-implicit-conversion-in-loop

Summary:
Add support for arrays (and structure that use naked pointers for their iterator, like std::array) in performance-implicit-conversion-in-loop

Reviewers: alexfh

Reviewed By: alexfh

Subscribers: cfe-commits

Patch by Alex Pilkiewicz.

Differential Revision: https://reviews.llvm.org/D47945

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@334400 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 15 insertions, 9 deletions

diff --git a/clang-tidy/performance/ImplicitConversionInLoopCheck.cpp b/clang-tidy/performance/ImplicitConversionInLoopCheck.cpp
index 2acbca34..1a5605f5 100644
--- a/clang-tidy/performance/ImplicitConversionInLoopCheck.cpp
+++ b/clang-tidy/performance/ImplicitConversionInLoopCheck.cpp
@@ -28,7 +28,7 @@ namespace performance {
 static bool IsNonTrivialImplicitCast(const Stmt *ST) {
   if (const auto *ICE = dyn_cast<ImplicitCastExpr>(ST)) {
     return (ICE->getCastKind() != CK_NoOp) ||
-           IsNonTrivialImplicitCast(ICE->getSubExpr());
+            IsNonTrivialImplicitCast(ICE->getSubExpr());
   }
   return false;
 }
@@ -39,7 +39,9 @@ void ImplicitConversionInLoopCheck::registerMatchers(MatchFinder *Finder) {
   // conversion. The check on the implicit conversion is done in check() because
   // we can't access implicit conversion subnode via matchers: has() skips casts
   // and materialize! We also bind on the call to operator* to get the proper
-  // type in the diagnostic message.
+  // type in the diagnostic message. We use both cxxOperatorCallExpr for user
+  // defined operator and unaryOperator when the iterator is a pointer, like
+  // for arrays or std::array.
   //
   // Note that when the implicit conversion is done through a user defined
   // conversion operator, the node is a CXXMemberCallExpr, not a
@@ -47,10 +49,14 @@ void ImplicitConversionInLoopCheck::registerMatchers(MatchFinder *Finder) {
   // cxxOperatorCallExpr() matcher.
   Finder->addMatcher(
       cxxForRangeStmt(hasLoopVariable(
-          varDecl(hasType(qualType(references(qualType(isConstQualified())))),
-                  hasInitializer(expr(hasDescendant(cxxOperatorCallExpr().bind(
-                                          "operator-call")))
-                                     .bind("init")))
+          varDecl(
+              hasType(qualType(references(qualType(isConstQualified())))),
+              hasInitializer(
+                  expr(anyOf(hasDescendant(
+                                 cxxOperatorCallExpr().bind("operator-call")),
+                             hasDescendant(unaryOperator(hasOperatorName("*"))
+                                               .bind("operator-call"))))
+                      .bind("init")))
               .bind("faulty-var"))),
       this);
 }
@@ -60,7 +66,7 @@ void ImplicitConversionInLoopCheck::check(
   const auto *VD = Result.Nodes.getNodeAs<VarDecl>("faulty-var");
   const auto *Init = Result.Nodes.getNodeAs<Expr>("init");
   const auto *OperatorCall =
-      Result.Nodes.getNodeAs<CXXOperatorCallExpr>("operator-call");
+      Result.Nodes.getNodeAs<Expr>("operator-call");
 
   if (const auto *Cleanup = dyn_cast<ExprWithCleanups>(Init))
     Init = Cleanup->getSubExpr();
@@ -79,7 +85,7 @@ void ImplicitConversionInLoopCheck::check(
 
 void ImplicitConversionInLoopCheck::ReportAndFix(
     const ASTContext *Context, const VarDecl *VD,
-    const CXXOperatorCallExpr *OperatorCall) {
+    const Expr *OperatorCall) {
   // We only match on const ref, so we should print a const ref version of the
   // type.
   QualType ConstType = OperatorCall->getType().withConst();
diff --git a/clang-tidy/performance/ImplicitConversionInLoopCheck.h b/clang-tidy/performance/ImplicitConversionInLoopCheck.h
index 8a459ab0..55cb84c3 100644
--- a/clang-tidy/performance/ImplicitConversionInLoopCheck.h
+++ b/clang-tidy/performance/ImplicitConversionInLoopCheck.h
@@ -28,7 +28,7 @@ public:
 
 private:
   void ReportAndFix(const ASTContext *Context, const VarDecl *VD,
-                    const CXXOperatorCallExpr *OperatorCall);
+                    const Expr *OperatorCall);
 };
 
 } // namespace performance