[ClangTidy - performance-unnecessary-value-param] Only add "const" when current param...

Reviewers: alexfh, sbenza, aaron.ballman

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D26207

llvm-svn: 286010

diff --git a/clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.cpp b/clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.cpp
index f00133c..1d229cf 100644 (file)
--- a/clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.cpp
+++ b/clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.cpp
@@ -128,7 +128,10 @@ void UnnecessaryValueParamCheck::check(const MatchFinder::MatchResult &Result) {
     const auto &CurrentParam = *FunctionDecl->getParamDecl(Index);
     Diag << utils::fixit::changeVarDeclToReference(CurrentParam,
                                                            *Result.Context);
-    if (!IsConstQualified)
+    // The parameter of each declaration needs to be checked individually as to
+    // whether it is const or not as constness can differ between definition and
+    // declaration.
+    if (!CurrentParam.getType().getCanonicalType().isConstQualified())
       Diag << utils::fixit::changeVarDeclToConst(CurrentParam);
   }
 }

diff --git a/clang-tools-extra/test/clang-tidy/performance-unnecessary-value-param.cpp b/clang-tools-extra/test/clang-tidy/performance-unnecessary-value-param.cpp
index 75c8e10..f83e965 100644 (file)
--- a/clang-tools-extra/test/clang-tidy/performance-unnecessary-value-param.cpp
+++ b/clang-tools-extra/test/clang-tidy/performance-unnecessary-value-param.cpp
@@ -244,3 +244,19 @@ struct IncompleteType;
 void NegativeForIncompleteType(IncompleteType I) {
   // CHECK-MESSAGES: [[@LINE-1]]:47: error: variable has incomplete type 'IncompleteType' [clang-diagnostic-error]
 }
+
+// Case where parameter in declaration is already const-qualified but not in
+// implementation. Make sure a second 'const' is not added to the declaration.
+void PositiveConstDeclaration(const ExpensiveToCopyType A);
+// CHECK-FIXES: void PositiveConstDeclaration(const ExpensiveToCopyType& A);
+void PositiveConstDeclaration(ExpensiveToCopyType A) {
+  // CHECK-MESSAGES: [[@LINE-1]]:51: warning: the parameter 'A' is copied
+  // CHECK-FIXES: void PositiveConstDeclaration(const ExpensiveToCopyType& A) {
+}
+
+void PositiveNonConstDeclaration(ExpensiveToCopyType A);
+// CHECK-FIXES: void PositiveNonConstDeclaration(const ExpensiveToCopyType& A);
+void PositiveNonConstDeclaration(const ExpensiveToCopyType A) {
+  // CHECK-MESSAGES: [[@LINE-1]]:60: warning: the const qualified parameter 'A'
+  // CHECK-FIXES: void PositiveNonConstDeclaration(const ExpensiveToCopyType& A) {
+}