[clang-tidy] new check 'readability-redundant-preprocessor'

Finds potentially redundant preprocessor directives.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D54349

llvm-svn: 350922

1 files changed, 36 insertions, 0 deletions

diff --git a/clang-tools-extra/test/clang-tidy/readability-redundant-preprocessor-ifdef.cpp b/clang-tools-extra/test/clang-tidy/readability-redundant-preprocessor-ifdef.cpp
new file mode 100644
index 00000000000..72b608b1c2c
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/readability-redundant-preprocessor-ifdef.cpp
@@ -0,0 +1,36 @@
+// RUN: %check_clang_tidy %s readability-redundant-preprocessor %t -- -- -DFOO
+
+// Positive testing.
+#ifdef FOO
+// CHECK-NOTES: [[@LINE+1]]:2: warning: nested redundant #ifdef; consider removing it [readability-redundant-preprocessor]
+#ifdef FOO
+// CHECK-NOTES: [[@LINE-3]]:2: note: previous #ifdef was here
+void f();
+#endif
+#endif
+
+// Positive testing of inverted condition.
+#ifdef FOO
+// CHECK-NOTES: [[@LINE+1]]:2: warning: nested redundant #ifndef; consider removing it [readability-redundant-preprocessor]
+#ifndef FOO
+// CHECK-NOTES: [[@LINE-3]]:2: note: previous #ifdef was here
+void f2();
+#endif
+#endif
+
+// Negative testing.
+#ifdef BAR
+void g();
+#endif
+
+#ifdef FOO
+#ifdef BAR
+void h();
+#endif
+#endif
+
+#ifdef FOO
+#ifndef BAR
+void i();
+#endif
+#endif