[clang-tidy] fix for NOLINT after macro expansion

Summary:
When having
``` c++
    #define MACRO code-with-warning
    MACRO; // NOLINT
```
clang-tidy would still show the warning, because
it searched for "NOLINT" only in the first line,
not on the second.
This caused e.g. https://llvm.org/bugs/show_bug.cgi?id=29089
(where the macro was defined in a system header). See also
the added test cases.
Now clang-tidy looks at the line of macro invocation and every line
of macro definition for a NOLINT comment.

Reviewers: alexfh, aaron.ballman, hokein

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D24845

llvm-svn: 282330

1 files changed, 13 insertions, 1 deletions

diff --git a/clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp b/clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp
index 8dbae40e4e9..ca3877207f8 100644
--- a/clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp
+++ b/clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp
@@ -294,12 +294,24 @@ static bool LineIsMarkedWithNOLINT(SourceManager& SM, SourceLocation Loc) {
   return false;
 }
 
+static bool LineIsMarkedWithNOLINTinMacro(SourceManager &SM,
+                                          SourceLocation Loc) {
+  while (true) {
+    if (LineIsMarkedWithNOLINT(SM, Loc))
+      return true;
+    if (!Loc.isMacroID())
+      return false;
+    Loc = SM.getImmediateExpansionRange(Loc).first;
+  }
+  return false;
+}
+
 void ClangTidyDiagnosticConsumer::HandleDiagnostic(
     DiagnosticsEngine::Level DiagLevel, const Diagnostic &Info) {
   if (Info.getLocation().isValid() &&
       DiagLevel != DiagnosticsEngine::Error &&
       DiagLevel != DiagnosticsEngine::Fatal &&
-      LineIsMarkedWithNOLINT(Diags->getSourceManager(), Info.getLocation())) {
+      LineIsMarkedWithNOLINTinMacro(Diags->getSourceManager(), Info.getLocation())) {
     ++Context.Stats.ErrorsIgnoredNOLINT;
     return;
   }