[clang-tidy] Add readability-simplify-boolean-expr check to clang-tidy

This check looks for comparisons between boolean expressions and boolean
constants and simplifies them to just use the appropriate boolean expression
directly.

if (b == true) becomes if (b)
if (b == false) becomes if (!b)
if (b && true) becomes if (b)
if (b && false) becomes if (false)
if (b || true) becomes if (true)
if (b || false) becomes if (b)
e ? true : false becomes e
e ? false : true becomes !e
if (true) t(); else f(); becomes t();
if (false) t(); else f(); becomes f();
if (e) return true; else return false; becomes return (e);
if (e) return false; else return true; becomes return !(e);
if (e) b = true; else b = false; becomes b = e;
if (e) b = false; else b = true; becomes b = !(e);

http://reviews.llvm.org/D7648

Patch by Richard Thomson!

llvm-svn: 234626

1 files changed, 5 insertions, 1 deletions

diff --git a/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp b/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
index c82062092cc..bf118f88ace 100644
--- a/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
@@ -18,6 +18,7 @@
 #include "RedundantSmartptrGetCheck.h"
 #include "RedundantStringCStrCheck.h"
 #include "ShrinkToFitCheck.h"
+#include "SimplifyBooleanExprCheck.h"
 
 namespace clang {
 namespace tidy {
@@ -40,7 +41,10 @@ public:
         "readability-redundant-smartptr-get");
     CheckFactories.registerCheck<RedundantStringCStrCheck>(
         "readability-redundant-string-cstr");
-    CheckFactories.registerCheck<ShrinkToFitCheck>("readability-shrink-to-fit");
+    CheckFactories.registerCheck<ShrinkToFitCheck>(
+        "readability-shrink-to-fit");
+    CheckFactories.registerCheck<SimplifyBooleanExprCheck>(
+        "readability-simplify-boolean-expr");
   }
 };