[PATCH] D24845: [clang-tidy] fix for NOLINT after macro expansion

[Matthias Gehre via cfe-commits]

mgehre created this revision.
mgehre added reviewers: alexfh, aaron.ballman, hokein.
mgehre added a subscriber: cfe-commits.

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.

https://reviews.llvm.org/D24845

Files:
  clang-tidy/ClangTidyDiagnosticConsumer.cpp
  test/clang-tidy/nolint.cpp

Index: test/clang-tidy/nolint.cpp
===================================================================
--- test/clang-tidy/nolint.cpp
+++ test/clang-tidy/nolint.cpp
@@ -13,4 +13,18 @@
   int j; // NOLINT
 }
 
-// CHECK-MESSAGES: Suppressed 3 warnings (3 NOLINT)
+#define MACRO(X) class X { X(int i); };
+MACRO(D)
+// CHECK-MESSAGES: :[[@LINE-1]]:7: warning: single-argument constructors must be marked explicit
+MACRO(E) // NOLINT
+
+#define MACRO_NOARG class F { F(int i); };
+MACRO_NOARG // NOLINT
+
+#define MACRO_NOLINT class G { G(int i); }; // NOLINT
+MACRO_NOLINT
+
+#define DOUBLE_MACRO MACRO(H) // NOLINT
+DOUBLE_MACRO
+
+// CHECK-MESSAGES: Suppressed 7 warnings (7 NOLINT)
Index: clang-tidy/ClangTidyDiagnosticConsumer.cpp
===================================================================
--- clang-tidy/ClangTidyDiagnosticConsumer.cpp
+++ clang-tidy/ClangTidyDiagnosticConsumer.cpp
@@ -294,12 +294,24 @@
   return false;
 }
 
+static bool LineIsMarkedWithNOLINTinMacro(SourceManager &SM,
+                                          SourceLocation Loc) {
+  while (true) {
+    if (LineIsMarkedWithNOLINT(SM, Loc))
+      return true;
+    if (!Loc.isMacroID())
+      break;
+    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;
   }


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