From aca7a0253d6e3116f846ad530b19d89644a64267 Mon Sep 17 00:00:00 2001
From: Jonathan Wakely <jwakely@redhat.com>
Date: Thu, 22 Jul 2021 14:37:24 +0100
Subject: [PATCH] libstdc++: Use std::addressof in ranges::uninitialized_xxx
 [PR101571]

Make the ranges::uninitialized_xxx algorithms use std::addressof to
protect against iterator types that overload operator&.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/101571
	* include/bits/ranges_uninitialized.h (_DestroyGuard): Change
	constructor parameter to reference and use addressof.
	* testsuite/util/testsuite_iterators.h: Define deleted operator&
	overloads for test iterators.
---
 libstdc++-v3/include/bits/ranges_uninitialized.h  | 26 +++++++++++------------
 libstdc++-v3/testsuite/util/testsuite_iterators.h |  8 +++++++
 2 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/libstdc++-v3/include/bits/ranges_uninitialized.h b/libstdc++-v3/include/bits/ranges_uninitialized.h
index 0a46fba..40664ea 100644
--- a/libstdc++-v3/include/bits/ranges_uninitialized.h
+++ b/libstdc++-v3/include/bits/ranges_uninitialized.h
@@ -106,8 +106,8 @@ namespace ranges
 
       public:
 	explicit
-	_DestroyGuard(const _Iter* __iter)
-	  : _M_first(*__iter), _M_cur(__iter)
+	_DestroyGuard(const _Iter& __iter)
+	  : _M_first(__iter), _M_cur(std::__addressof(__iter))
 	{ }
 
 	void
@@ -127,7 +127,7 @@ namespace ranges
       struct _DestroyGuard<_Iter>
       {
 	explicit
-	_DestroyGuard(const _Iter*)
+	_DestroyGuard(const _Iter&)
 	{ }
 
 	void
@@ -149,7 +149,7 @@ namespace ranges
 	  return ranges::next(__first, __last);
 	else
 	  {
-	    auto __guard = __detail::_DestroyGuard(&__first);
+	    auto __guard = __detail::_DestroyGuard(__first);
 	    for (; __first != __last; ++__first)
 	      ::new (__detail::__voidify(*__first)) _ValueType;
 	    __guard.release();
@@ -181,7 +181,7 @@ namespace ranges
 	  return ranges::next(__first, __n);
 	else
 	  {
-	    auto __guard = __detail::_DestroyGuard(&__first);
+	    auto __guard = __detail::_DestroyGuard(__first);
 	    for (; __n > 0; ++__first, (void) --__n)
 	      ::new (__detail::__voidify(*__first)) _ValueType;
 	    __guard.release();
@@ -207,7 +207,7 @@ namespace ranges
 	  return ranges::fill(__first, __last, _ValueType());
 	else
 	  {
-	    auto __guard = __detail::_DestroyGuard(&__first);
+	    auto __guard = __detail::_DestroyGuard(__first);
 	    for (; __first != __last; ++__first)
 	      ::new (__detail::__voidify(*__first)) _ValueType();
 	    __guard.release();
@@ -240,7 +240,7 @@ namespace ranges
 	  return ranges::fill_n(__first, __n, _ValueType());
 	else
 	  {
-	    auto __guard = __detail::_DestroyGuard(&__first);
+	    auto __guard = __detail::_DestroyGuard(__first);
 	    for (; __n > 0; ++__first, (void) --__n)
 	      ::new (__detail::__voidify(*__first)) _ValueType();
 	    __guard.release();
@@ -279,7 +279,7 @@ namespace ranges
 	  }
 	else
 	  {
-	    auto __guard = __detail::_DestroyGuard(&__ofirst);
+	    auto __guard = __detail::_DestroyGuard(__ofirst);
 	    for (; __ifirst != __ilast && __ofirst != __olast;
 		 ++__ofirst, (void)++__ifirst)
 	      ::new (__detail::__voidify(*__ofirst)) _OutType(*__ifirst);
@@ -326,7 +326,7 @@ namespace ranges
 	  }
 	else
 	  {
-	    auto __guard = __detail::_DestroyGuard(&__ofirst);
+	    auto __guard = __detail::_DestroyGuard(__ofirst);
 	    for (; __n > 0 && __ofirst != __olast;
 		 ++__ofirst, (void)++__ifirst, (void)--__n)
 	      ::new (__detail::__voidify(*__ofirst)) _OutType(*__ifirst);
@@ -368,7 +368,7 @@ namespace ranges
 	  }
 	else
 	  {
-	    auto __guard = __detail::_DestroyGuard(&__ofirst);
+	    auto __guard = __detail::_DestroyGuard(__ofirst);
 	    for (; __ifirst != __ilast && __ofirst != __olast;
 		 ++__ofirst, (void)++__ifirst)
 	      ::new (__detail::__voidify(*__ofirst))
@@ -419,7 +419,7 @@ namespace ranges
 	  }
 	else
 	  {
-	    auto __guard = __detail::_DestroyGuard(&__ofirst);
+	    auto __guard = __detail::_DestroyGuard(__ofirst);
 	    for (; __n > 0 && __ofirst != __olast;
 		 ++__ofirst, (void)++__ifirst, (void)--__n)
 	      ::new (__detail::__voidify(*__ofirst))
@@ -446,7 +446,7 @@ namespace ranges
 	  return ranges::fill(__first, __last, __x);
 	else
 	  {
-	    auto __guard = __detail::_DestroyGuard(&__first);
+	    auto __guard = __detail::_DestroyGuard(__first);
 	    for (; __first != __last; ++__first)
 	      ::new (__detail::__voidify(*__first)) _ValueType(__x);
 	    __guard.release();
@@ -479,7 +479,7 @@ namespace ranges
 	  return ranges::fill_n(__first, __n, __x);
 	else
 	  {
-	    auto __guard = __detail::_DestroyGuard(&__first);
+	    auto __guard = __detail::_DestroyGuard(__first);
 	    for (; __n > 0; ++__first, (void)--__n)
 	      ::new (__detail::__voidify(*__first)) _ValueType(__x);
 	    __guard.release();
diff --git a/libstdc++-v3/testsuite/util/testsuite_iterators.h b/libstdc++-v3/testsuite/util/testsuite_iterators.h
index 6b835ac..d0f87b1 100644
--- a/libstdc++-v3/testsuite/util/testsuite_iterators.h
+++ b/libstdc++-v3/testsuite/util/testsuite_iterators.h
@@ -175,10 +175,14 @@ namespace __gnu_test
 #if __cplusplus >= 201103L
     template<typename U>
       void operator,(const U&) const = delete;
+
+    void operator&() const = delete;
 #else
   private:
     template<typename U>
       void operator,(const U&) const;
+
+    void operator&() const;
 #endif
   };
 
@@ -288,10 +292,14 @@ namespace __gnu_test
 #if __cplusplus >= 201103L
     template<typename U>
       void operator,(const U&) const = delete;
+
+    void operator&() const = delete;
 #else
   private:
     template<typename U>
       void operator,(const U&) const;
+
+    void operator&() const;
 #endif
   };
 
-- 
2.7.4