From 3574b800cf72c3209e6200eee9fb93fd0228ad5f Mon Sep 17 00:00:00 2001
From: Nikolas Klauser <nikolasklauser@berlin.de>
Date: Thu, 10 Nov 2022 23:57:43 +0100
Subject: [PATCH] [libc++][clang-tidy] Enable readability-simplify-boolean-expr

Reviewed By: ldionne, #libc

Spies: Eugene.Zelenko, aheejin, libcxx-commits, xazax.hun

Differential Revision: https://reviews.llvm.org/D137804
---
 libcxx/.clang-tidy                | 3 ++-
 libcxx/include/__format/unicode.h | 5 +----
 libcxx/include/__locale           | 2 +-
 libcxx/include/charconv           | 2 +-
 libcxx/include/fstream            | 5 +++--
 libcxx/include/locale             | 5 +++--
 6 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/libcxx/.clang-tidy b/libcxx/.clang-tidy
index 88b9de1f56a8..4bc25c3ae605 100644
--- a/libcxx/.clang-tidy
+++ b/libcxx/.clang-tidy
@@ -25,6 +25,7 @@ Checks: >
   readability-redundant-control-flow,
   readability-redundant-function-ptr-dereference,
   readability-redundant-preprocessor,
+  readability-simplify-boolean-expr,
   readability-simplify-subscript-expr,
   readability-uniqueptr-delete-release,
 
@@ -63,4 +64,4 @@ CheckOptions:
 # readability-redundant-access-specifiers,
 # readability-redundant-declaration,
 # readability-redundant-member-init,
-# readability-simplify-boolean-expr,
+#
diff --git a/libcxx/include/__format/unicode.h b/libcxx/include/__format/unicode.h
index 94d3e2184836..50f66e72570b 100644
--- a/libcxx/include/__format/unicode.h
+++ b/libcxx/include/__format/unicode.h
@@ -369,10 +369,7 @@ _LIBCPP_HIDE_FROM_ABI constexpr bool __at_extended_grapheme_cluster_break(
 
   if (__prev == __property::__Regional_Indicator && __next == __property::__Regional_Indicator) { // GB12 + GB13
     __ri_break_allowed = !__ri_break_allowed;
-    if (__ri_break_allowed)
-      return true;
-
-    return false;
+    return __ri_break_allowed;
   }
 
   // *** Otherwise, break everywhere. ***
diff --git a/libcxx/include/__locale b/libcxx/include/__locale
index e02724c862e2..f1e0a07fd06b 100644
--- a/libcxx/include/__locale
+++ b/libcxx/include/__locale
@@ -701,7 +701,7 @@ public:
     const char_type* scan_not(mask __m, const char_type* __low, const char_type* __high) const
     {
         for (; __low != __high; ++__low)
-            if (!(isascii(*__low) && (__tab_[static_cast<int>(*__low)] & __m)))
+            if (!isascii(*__low) || !(__tab_[static_cast<int>(*__low)] & __m))
                 break;
         return __low;
     }
diff --git a/libcxx/include/charconv b/libcxx/include/charconv
index d2031eac8ba9..4063117b30ad 100644
--- a/libcxx/include/charconv
+++ b/libcxx/include/charconv
@@ -250,7 +250,7 @@ struct _LIBCPP_HIDDEN __traits : __traits_base<_Tp>
         int __i = digits;
         do
         {
-            if (!('0' <= *__p && *__p <= '9'))
+            if (*__p < '0' || *__p > '9')
                 break;
             __cprod[--__i] = *__p++ - '0';
         } while (__p != __ep && __i != 0);
diff --git a/libcxx/include/fstream b/libcxx/include/fstream
index b8417f3e6c02..65b22a4db70a 100644
--- a/libcxx/include/fstream
+++ b/libcxx/include/fstream
@@ -753,9 +753,10 @@ basic_filebuf<_CharT, _Traits>::underflow()
         }
         else
         {
-            _LIBCPP_ASSERT ( !(__extbufnext_ == NULL && (__extbufend_ != __extbufnext_)), "underflow moving from NULL" );
-            if (__extbufend_ != __extbufnext_)
+            if (__extbufend_ != __extbufnext_) {
+                _LIBCPP_ASSERT(__extbufnext_ != nullptr, "underflow moving from NULL" );
                 _VSTD::memmove(__extbuf_, __extbufnext_, __extbufend_ - __extbufnext_);
+            }
             __extbufnext_ = __extbuf_ + (__extbufend_ - __extbufnext_);
             __extbufend_ = __extbuf_ + (__extbuf_ == __extbuf_min_ ? sizeof(__extbuf_min_) : __ebs_);
             size_t __nmemb = _VSTD::min(static_cast<size_t>(__ibs_ - __unget_sz),
diff --git a/libcxx/include/locale b/libcxx/include/locale
index 015efd8b0dc7..c00b1dfc9375 100644
--- a/libcxx/include/locale
+++ b/libcxx/include/locale
@@ -4013,9 +4013,10 @@ _LIBCPP_SUPPRESS_DEPRECATED_POP
         }
         else
         {
-             _LIBCPP_ASSERT(!(__extbufnext_ == NULL && (__extbufend_ != __extbufnext_)), "underflow moving from NULL" );
-             if (__extbufend_ != __extbufnext_)
+             if (__extbufend_ != __extbufnext_) {
+                _LIBCPP_ASSERT(__extbufnext_ != NULL, "underflow moving from NULL" );
                 _VSTD::memmove(__extbuf_, __extbufnext_, __extbufend_ - __extbufnext_);
+             }
             __extbufnext_ = __extbuf_ + (__extbufend_ - __extbufnext_);
             __extbufend_ = __extbuf_ + (__extbuf_ == __extbuf_min_ ? sizeof(__extbuf_min_) : __ebs_);
             streamsize __nmemb = _VSTD::min(static_cast<streamsize>(this->egptr() - this->eback() - __unget_sz),