Re: [Patch, regex, libstdc++/70745] Fix match_not_bow and match_not_eow

[Tim Shen]

On Fri, Apr 22, 2016 at 3:23 AM, Jonathan Wakely wrote:
> OK for trunk.
>
> It is a small, safe change, so OK for the branches (6/5/4.9) too, but
> let's wait a short while to make sure nobody finds any problems on
> trunk (and gcc-6-branch is frozen for release right now anyway).

Committed to trunk as r235382.

Thanks!


-- 
Regards,
Tim Shen

Re: [Patch, regex, libstdc++/70745] Fix match_not_bow and match_not_eow

[Jonathan Wakely]

On 21/04/16 21:10 -0700, Tim Shen wrote:

Bootstrapped and tested on x86-pc-linux-gnu debug.

It is a conformance fix, but I don't think it's very important. I'm
happy to backport it to gcc 5/4.9, but if it's not considered
necessary, I'm Ok as well.


OK for trunk.

It is a small, safe change, so OK for the branches (6/5/4.9) too, but
let's wait a short while to make sure nobody finds any problems on
trunk (and gcc-6-branch is frozen for release right now anyway).

Thanks.

[Patch, regex, libstdc++/70745] Fix match_not_bow and match_not_eow

[Tim Shen]

Bootstrapped and tested on x86-pc-linux-gnu debug.

It is a conformance fix, but I don't think it's very important. I'm
happy to backport it to gcc 5/4.9, but if it's not considered
necessary, I'm Ok as well.

Thanks!


-- 
Regards,
Tim Shen
commit 7f4f729d5dd80050ff966398e28909a40fb57932
Author: Tim Shen 
Date:   Thu Apr 21 21:02:11 2016 -0700

PR libstdc++/70745
* include/bits/regex_executor.tcc (_Executor<>::_M_word_boundary):
Fix the match_not_bow and match_not_eow behavior.
* testsuite/28_regex/regression.cc: Add testcase.

diff --git a/libstdc++-v3/include/bits/regex_executor.tcc 
b/libstdc++-v3/include/bits/regex_executor.tcc
index 2abd020..6bbcb1b 100644
--- a/libstdc++-v3/include/bits/regex_executor.tcc
+++ b/libstdc++-v3/include/bits/regex_executor.tcc
@@ -413,6 +413,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 bool _Executor<_BiIter, _Alloc, _TraitsT, __dfs_mode>::
 _M_word_boundary() const
 {
+  if (_M_current == _M_begin && (_M_flags & 
regex_constants::match_not_bow))
+   return false;
+  if (_M_current == _M_end && (_M_flags & regex_constants::match_not_eow))
+   return false;
+
   bool __left_is_word = false;
   if (_M_current != _M_begin
  || (_M_flags & regex_constants::match_prev_avail))
@@ -424,13 +429,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   bool __right_is_word =
 _M_current != _M_end && _M_is_word(*_M_current);
 
-  if (__left_is_word == __right_is_word)
-   return false;
-  if (__left_is_word && !(_M_flags & regex_constants::match_not_eow))
-   return true;
-  if (__right_is_word && !(_M_flags & regex_constants::match_not_bow))
-   return true;
-  return false;
+  return __left_is_word != __right_is_word;
 }
 
 _GLIBCXX_END_NAMESPACE_VERSION
diff --git a/libstdc++-v3/testsuite/28_regex/regression.cc 
b/libstdc++-v3/testsuite/28_regex/regression.cc
index c9a3402..d367c8b 100644
--- a/libstdc++-v3/testsuite/28_regex/regression.cc
+++ b/libstdc++-v3/testsuite/28_regex/regression.cc
@@ -45,7 +45,20 @@ test02()
   "/ghci"
 };
   auto rx = std::regex(re_str, std::regex_constants::grep | 
std::regex_constants::icase);
-  VERIFY(std::regex_search("/abcd", rx));
+  VERIFY(regex_search_debug("/abcd", rx));
+}
+
+void
+test03()
+{
+  bool test __attribute__((unused)) = true;
+
+  VERIFY(regex_match_debug("a.", regex(R"(a\b.)"), 
regex_constants::match_not_eow));
+  VERIFY(regex_match_debug(".a", regex(R"(.\ba)"), 
regex_constants::match_not_bow));
+  VERIFY(regex_search_debug("a", regex(R"(^\b)")));
+  VERIFY(regex_search_debug("a", regex(R"(\b$)")));
+  VERIFY(!regex_search_debug("a", regex(R"(^\b)"), 
regex_constants::match_not_bow));
+  VERIFY(!regex_search_debug("a", regex(R"(\b$)"), 
regex_constants::match_not_eow));
 }
 
 int
@@ -53,6 +66,7 @@ main()
 {
   test01();
   test02();
+  test03();
   return 0;
 }