[clang-tidy] Add a checker for implicit bool conversion of a bool*.

The goal is to find code like the example below, which is likely a typo
where someone meant to write "if (*b)".
bool *b = SomeFunction();
 if (b) {
   // b never dereferenced
 }

This checker naturally has a relatively high false positive rate so it
applies some heuristics to avoid cases where the pointer is checked for
nullptr before being written.

Differential Revision: http://reviews.llvm.org/D4458

llvm-svn: 212797

1 files changed, 34 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/misc/BoolPointerImplicitConversion.h b/clang-tools-extra/clang-tidy/misc/BoolPointerImplicitConversion.h
new file mode 100644
index 00000000000..16c0d631eec
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/misc/BoolPointerImplicitConversion.h
@@ -0,0 +1,34 @@
+//===--- BoolPointerImplicitConversion.h - clang-tidy -----------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_BOOL_POINTER_IMPLICIT_CONV_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_BOOL_POINTER_IMPLICIT_CONV_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+
+/// \brief Checks for conditions based on implicit conversion from a bool
+/// pointer to bool e.g.
+/// bool *p;
+/// if (p) {
+///   // Never used in a pointer-specific way.
+/// }
+class BoolPointerImplicitConversion : public ClangTidyCheck {
+public:
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+};
+
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_BOOL_POINTER_IMPLICIT_CONV_H
+