[clang-tidy] Do not issue fix for functions that are referenced outside of callExpr

Summary: Suppress fixes for functions that are referenced within the
compilation unit outside of a call expression as the signature change
could break the code referencing the function.

We still issue a warning in this case so that users can decide to
manually change the function signature.

Reviewers: alexfh, sbenza, aaron.ballman

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D26203

llvm-svn: 286424

1 files changed, 18 insertions, 0 deletions

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 2006942c181..3da15a359c8 100644
--- a/clang-tools-extra/test/clang-tidy/performance-unnecessary-value-param.cpp
+++ b/clang-tools-extra/test/clang-tidy/performance-unnecessary-value-param.cpp
@@ -253,3 +253,21 @@ void PositiveNonConstDeclaration(const ExpensiveToCopyType A) {
   // CHECK-MESSAGES: [[@LINE-1]]:60: warning: the const qualified parameter 'A'
   // CHECK-FIXES: void PositiveNonConstDeclaration(const ExpensiveToCopyType& A) {
 }
+
+void PositiveOnlyMessageAsReferencedInCompilationUnit(ExpensiveToCopyType A) {
+  // CHECK-MESSAGES: [[@LINE-1]]:75: warning: the parameter 'A' is copied
+  // CHECK-FIXES: void PositiveOnlyMessageAsReferencedInCompilationUnit(ExpensiveToCopyType A) {
+}
+
+void ReferenceFunctionOutsideOfCallExpr() {
+  void (*ptr)(ExpensiveToCopyType) = &PositiveOnlyMessageAsReferencedInCompilationUnit;
+}
+
+void PositiveMessageAndFixAsFunctionIsCalled(ExpensiveToCopyType A) {
+  // CHECK-MESSAGES: [[@LINE-1]]:66: warning: the parameter 'A' is copied
+  // CHECK-FIXES: void PositiveMessageAndFixAsFunctionIsCalled(const ExpensiveToCopyType& A) {
+}
+
+void ReferenceFunctionByCallingIt() {
+  PositiveMessageAndFixAsFunctionIsCalled(ExpensiveToCopyType());
+}