[clangd] Disable cppcoreguidelines-macro-to-enum clang-tidy checker (#129478)

Clangd does not support its checker because the checker relies on having
seen preprocessor conditionals that occur in the preamble, and clangd
does not currently replay those.

This checker was already disabled under its main name,
modernize-macro-to-enum (https://github.com/clangd/clangd/issues/1464).
This commit disables it under the alternative name
cppcoreguidelines-macro-to-enum as well.

Fixes https://github.com/llvm/llvm-project/issues/127965

2 files changed, 16 insertions, 0 deletions

diff --git a/clang-tools-extra/clangd/TidyProvider.cpp b/clang-tools-extra/clangd/TidyProvider.cpp
index 2ac1232..1d79a7a 100644
--- a/clang-tools-extra/clangd/TidyProvider.cpp
+++ b/clang-tools-extra/clangd/TidyProvider.cpp
@@ -210,6 +210,7 @@ TidyProvider disableUnusableChecks(llvm::ArrayRef<std::string> ExtraBadChecks) {
       // Check relies on seeing ifndef/define/endif directives,
       // clangd doesn't replay those when using a preamble.
       "-llvm-header-guard", "-modernize-macro-to-enum",
+      "-cppcoreguidelines-macro-to-enum",
 
       // ----- Crashing Checks -----
 
diff --git a/clang-tools-extra/clangd/unittests/DiagnosticsTests.cpp b/clang-tools-extra/clangd/unittests/DiagnosticsTests.cpp
index 7a47d6e..f9ff6f2 100644
--- a/clang-tools-extra/clangd/unittests/DiagnosticsTests.cpp
+++ b/clang-tools-extra/clangd/unittests/DiagnosticsTests.cpp
@@ -823,6 +823,21 @@ TEST(DiagnosticTest, ClangTidyNoLiteralDataInMacroToken) {
   EXPECT_THAT(TU.build().getDiagnostics(), UnorderedElementsAre()); // no-crash
 }
 
+TEST(DiagnosticTest, ClangTidyMacroToEnumCheck) {
+  Annotations Main(R"cpp(
+    #if 1
+    auto foo();
+    #endif
+  )cpp");
+  TestTU TU = TestTU::withCode(Main.code());
+  std::vector<TidyProvider> Providers;
+  Providers.push_back(
+      addTidyChecks("cppcoreguidelines-macro-to-enum,modernize-macro-to-enum"));
+  Providers.push_back(disableUnusableChecks());
+  TU.ClangTidyProvider = combine(std::move(Providers));
+  EXPECT_THAT(TU.build().getDiagnostics(), UnorderedElementsAre()); // no-crash
+}
+
 TEST(DiagnosticTest, ElseAfterReturnRange) {
   Annotations Main(R"cpp(
     int foo(int cond) {