[libTooling] Add function to Transformer to create a no-op edit.

This functionality is commonly needed in clang tidy checks (based on
transformer) that only print warnings, without suggesting any edits. The no-op
edit allows the user to associate a diagnostic message with a source location.

Differential Revision: https://reviews.llvm.org/D89961

1 files changed, 8 insertions, 0 deletions

diff --git a/clang/unittests/Tooling/TransformerTest.cpp b/clang/unittests/Tooling/TransformerTest.cpp
index a8d6d3d..ff735cd 100644
--- a/clang/unittests/Tooling/TransformerTest.cpp
+++ b/clang/unittests/Tooling/TransformerTest.cpp
@@ -426,6 +426,14 @@ TEST_F(TransformerTest, NoEdits) {
   testRule(makeRule(returnStmt().bind("return"), noEdits()), Input, Input);
 }
 
+TEST_F(TransformerTest, NoopEdit) {
+  using transformer::node;
+  using transformer::noopEdit;
+  std::string Input = "int f(int x) { return x; }";
+  testRule(makeRule(returnStmt().bind("return"), noopEdit(node("return"))),
+           Input, Input);
+}
+
 TEST_F(TransformerTest, IfBound2Args) {
   using transformer::ifBound;
   std::string Input = "int f(int x) { return x; }";