[gcc r13-8304] libstdc++: Avoid reusing moved-from iterators in PSTL tests [PR90276]

[Jonathan Wakely]

https://gcc.gnu.org/g:3c04a1533b32362c7c28fc32b05623dda45a1b44

commit r13-8304-g3c04a1533b32362c7c28fc32b05623dda45a1b44
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Wed Jan 31 10:41:49 2024 +0000

    libstdc++: Avoid reusing moved-from iterators in PSTL tests [PR90276]
    
    The reverse_invoker utility for PSTL tests uses forwarding references for
    all parameters, but some of those parameters get forwarded to move
    constructors which then leave the objects in a moved-from state. When
    the parameters are forwarded a second time that results in making new
    copies of moved-from iterators.  For libstdc++ debug mode iterators, the
    moved-from state is singular, which means copying them will abort at
    runtime.
    
    The fix is to make copies of iterator arguments instead of forwarding
    them.
    
    The callers of reverse_invoker::operator() also forward the iterators
    multiple times, but that's OK because reverse_invoker accepts them by
    forwarding reference but then breaks the chain of forwarding and copies
    them as lvalues.
    
    libstdc++-v3/ChangeLog:
    
            PR libstdc++/90276
            * testsuite/util/pstl/test_utils.h (reverse_invoker): Do not use
            perfect forwarding for iterator arguments.
    
    (cherry picked from commit 723a7c1ad29523b9ddff53c7b147bffea56fbb63)

Diff:
---
 libstdc++-v3/testsuite/util/pstl/test_utils.h | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/libstdc++-v3/testsuite/util/pstl/test_utils.h b/libstdc++-v3/testsuite/util/pstl/test_utils.h
index 80a8f9c7b879..9991f37d7eee 100644
--- a/libstdc++-v3/testsuite/util/pstl/test_utils.h
+++ b/libstdc++-v3/testsuite/util/pstl/test_utils.h
@@ -1007,18 +1007,18 @@ struct iterator_invoker<std::forward_iterator_tag, /*isReverse=*/std::true_type>
 template <typename IsReverse>
 struct reverse_invoker
 {
-    template <typename... Rest>
+    template <typename Policy, typename Op, typename... Rest>
     void
-    operator()(Rest&&... rest)
+    operator()(Policy&& exec, Op op, Rest&&... rest)
     {
         // Random-access iterator
-        iterator_invoker<std::random_access_iterator_tag, IsReverse>()(std::forward<Rest>(rest)...);
+        iterator_invoker<std::random_access_iterator_tag, IsReverse>()(std::forward<Policy>(exec), op, rest...);
 
         // Forward iterator
-        iterator_invoker<std::forward_iterator_tag, IsReverse>()(std::forward<Rest>(rest)...);
+        iterator_invoker<std::forward_iterator_tag, IsReverse>()(std::forward<Policy>(exec), op, rest...);
 
         // Bidirectional iterator
-        iterator_invoker<std::bidirectional_iterator_tag, IsReverse>()(std::forward<Rest>(rest)...);
+        iterator_invoker<std::bidirectional_iterator_tag, IsReverse>()(std::forward<Policy>(exec), op, rest...);
     }
 };