[ClangTidy - performance-unnecessary-value-param] Only add "const" when current parameter is not already const qualified

Reviewers: alexfh, sbenza, aaron.ballman

Subscribers: cfe-commits

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

llvm-svn: 286010

1 files changed, 4 insertions, 1 deletions

diff --git a/clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.cpp b/clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.cpp
index f00133c4987..1d229cf1e38 100644
--- 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);
   }
 }