From: Jonathan Wakely <jwakely@redhat.com>
Date: Thu, 18 May 2017 15:30:42 +0000 (+0100)
Subject: libstdc++/78236 fix past-the-end std::regex_iterator
X-Git-Tag: releases/gcc-5.5.0~355
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5298e715c4df822d31a6292b893f3f0a60c0304d;p=thirdparty%2Fgcc.git

libstdc++/78236 fix past-the-end std::regex_iterator

Backport from mainline
2016-11-09  Tim Shen  <timshen@google.com>

	PR libstdc++/78236
	* libstdc++-v3/include/bits/regex.h (regex_iterator::regex_iterator()):
	Define end() as _M_pregex == nullptr.
	* libstdc++-v3/include/bits/regex.tcc (regex_iterator::operator==(),
	regex_iterator::operator++()): Fix operator==() and operator++() to
	look at null-ness of _M_pregex on both sides.
	* testsuite/28_regex/regression.cc: New testcase.

From-SVN: r248230
---

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index da49a499f14a..7674fb7ca9f9 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,5 +1,16 @@
 2017-05-18  Jonathan Wakely  <jwakely@redhat.com>
 
+	Backport from mainline
+	2016-11-09  Tim Shen  <timshen@google.com>
+
+	PR libstdc++/78236
+	* libstdc++-v3/include/bits/regex.h (regex_iterator::regex_iterator()):
+	Define end() as _M_pregex == nullptr.
+	* libstdc++-v3/include/bits/regex.tcc (regex_iterator::operator==(),
+	regex_iterator::operator++()): Fix operator==() and operator++() to
+	look at null-ness of _M_pregex on both sides.
+	* testsuite/28_regex/regression.cc: New testcase.
+
 	Backport from mainline
 	2016-12-15  Jonathan Wakely  <jwakely@redhat.com>
 
diff --git a/libstdc++-v3/include/bits/regex.h b/libstdc++-v3/include/bits/regex.h
index 90723e6e2551..c3cbfd7860f6 100644
--- a/libstdc++-v3/include/bits/regex.h
+++ b/libstdc++-v3/include/bits/regex.h
@@ -2454,7 +2454,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
        * one-past-the-end of a range.
        */
       regex_iterator()
-      : _M_match()
+      : _M_pregex()
       { }
 
       /**
diff --git a/libstdc++-v3/include/bits/regex.tcc b/libstdc++-v3/include/bits/regex.tcc
index 823ad51c3e8b..8aec031a6d30 100644
--- a/libstdc++-v3/include/bits/regex.tcc
+++ b/libstdc++-v3/include/bits/regex.tcc
@@ -509,12 +509,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     regex_iterator<_Bi_iter, _Ch_type, _Rx_traits>::
     operator==(const regex_iterator& __rhs) const
     {
-      return (_M_match.empty() && __rhs._M_match.empty())
-	|| (_M_begin == __rhs._M_begin
-	    && _M_end == __rhs._M_end
-	    && _M_pregex == __rhs._M_pregex
-	    && _M_flags == __rhs._M_flags
-	    && _M_match[0] == __rhs._M_match[0]);
+      if (_M_pregex == nullptr && __rhs._M_pregex == nullptr)
+	return true;
+      return _M_pregex == __rhs._M_pregex
+	  && _M_begin == __rhs._M_begin
+	  && _M_end == __rhs._M_end
+	  && _M_flags == __rhs._M_flags
+	  && _M_match[0] == __rhs._M_match[0];
     }
 
   template<typename _Bi_iter,
@@ -538,7 +539,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	    {
 	      if (__start == _M_end)
 		{
-		  _M_match = value_type();
+		  _M_pregex = nullptr;
 		  return *this;
 		}
 	      else
@@ -571,7 +572,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	      _M_match._M_begin = _M_begin;
 	    }
 	  else
-	    _M_match = value_type();
+	    _M_pregex = nullptr;
 	}
       return *this;
     }
diff --git a/libstdc++-v3/testsuite/28_regex/regression.cc b/libstdc++-v3/testsuite/28_regex/regression.cc
index 660d17070e60..0747cfcce78d 100644
--- a/libstdc++-v3/testsuite/28_regex/regression.cc
+++ b/libstdc++-v3/testsuite/28_regex/regression.cc
@@ -48,11 +48,33 @@ test02()
   VERIFY(std::regex_search("/abcd", rx));
 }
 
+// PR libstdc++/78236
+void
+test06()
+{
+  char const s[] = "afoo";
+  std::basic_regex<char> r("(f+)");
+  {
+    std::cregex_iterator i(s, s+sizeof(s), r);
+    std::cregex_iterator j(s, s+sizeof(s), r);
+    VERIFY(i == j);
+  }
+  // The iterator manipulation code must be repeated in the same scope
+  // to expose the undefined read during the execution of the ==
+  // operator (stack location reuse)
+  {
+    std::cregex_iterator i(s, s+sizeof(s), r);
+    std::cregex_iterator j;
+    VERIFY(!(i == j));
+  }
+}
+
 int
 main()
 {
   test01();
   test02();
+  test06();
   return 0;
 }