Reverting r260096; it causes build bot failures:
http://bb.pgr.jp/builders/cmake-clang-tools-x86_64-linux/builds/23351
http://lab.llvm.org:8011/builders/clang-s390x-linux/builds/492
llvm-svn: 260097
diff --git a/clang-tools-extra/clang-tidy/readability/SimplifyBooleanExprCheck.h b/clang-tools-extra/clang-tidy/readability/SimplifyBooleanExprCheck.h
index 4a80765..c74e6c4 100644
--- a/clang-tools-extra/clang-tidy/readability/SimplifyBooleanExprCheck.h
+++ b/clang-tools-extra/clang-tidy/readability/SimplifyBooleanExprCheck.h
@@ -19,8 +19,75 @@
/// Looks for boolean expressions involving boolean constants and simplifies
/// them to use the appropriate boolean expression directly.
///
-/// For the user-facing documentation see:
-/// http://clang.llvm.org/extra/clang-tidy/checks/readability-simplify-boolean-expr.html
+/// Examples:
+///
+/// =========================================== ================
+/// Initial expression Result
+/// ------------------------------------------- ----------------
+/// `if (b == true)` `if (b)`
+/// `if (b == false)` `if (!b)`
+/// `if (b && true)` `if (b)`
+/// `if (b && false)` `if (false)`
+/// `if (b || true)` `if (true)`
+/// `if (b || false)` `if (b)`
+/// `e ? true : false` `e`
+/// `e ? false : true` `!e`
+/// `if (true) t(); else f();` `t();`
+/// `if (false) t(); else f();` `f();`
+/// `if (e) return true; else return false;` `return e;`
+/// `if (e) return false; else return true;` `return !e;`
+/// `if (e) b = true; else b = false;` `b = e;`
+/// `if (e) b = false; else b = true;` `b = !e;`
+/// `if (e) return true; return false;` `return e;`
+/// `if (e) return false; return true;` `return !e;`
+/// =========================================== ================
+///
+/// The resulting expression `e` is modified as follows:
+/// 1. Unnecessary parentheses around the expression are removed.
+/// 2. Negated applications of `!` are eliminated.
+/// 3. Negated applications of comparison operators are changed to use the
+/// opposite condition.
+/// 4. Implicit conversions of pointer to `bool` are replaced with explicit
+/// comparisons to `nullptr`.
+/// 5. Implicit casts to `bool` are replaced with explicit casts to `bool`.
+/// 6. Object expressions with `explicit operator bool` conversion operators
+/// are replaced with explicit casts to `bool`.
+///
+/// Examples:
+/// 1. The ternary assignment `bool b = (i < 0) ? true : false;` has redundant
+/// parentheses and becomes `bool b = i < 0;`.
+///
+/// 2. The conditional return `if (!b) return false; return true;` has an
+/// implied double negation and becomes `return b;`.
+///
+/// 3. The conditional return `if (i < 0) return false; return true;` becomes
+/// `return i >= 0;`.
+///
+/// The conditional return `if (i != 0) return false; return true;` becomes
+/// `return i == 0;`.
+///
+/// 4. The conditional return `if (p) return true; return false;` has an
+/// implicit conversion of a pointer to `bool` and becomes
+/// `return p != nullptr;`.
+///
+/// The ternary assignment `bool b = (i & 1) ? true : false;` has an
+/// implicit conversion of `i & 1` to `bool` and becomes
+/// `bool b = static_cast<bool>(i & 1);`.
+///
+/// 5. The conditional return `if (i & 1) return true; else return false;` has
+/// an implicit conversion of an integer quantity `i & 1` to `bool` and
+/// becomes `return static_cast<bool>(i & 1);`
+///
+/// 6. Given `struct X { explicit operator bool(); };`, and an instance `x` of
+/// `struct X`, the conditional return `if (x) return true; return false;`
+/// becomes `return static_cast<bool>(x);`
+///
+/// When a conditional boolean return or assignment appears at the end of a
+/// chain of `if`, `else if` statements, the conditional statement is left
+/// unchanged unless the option `ChainedConditionalReturn` or
+/// `ChainedConditionalAssignment`, respectively, is specified as non-zero.
+/// The default value for both options is zero.
+///
class SimplifyBooleanExprCheck : public ClangTidyCheck {
public:
SimplifyBooleanExprCheck(StringRef Name, ClangTidyContext *Context);