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* [committed 1/2] libstdc++: Avoid reusing moved-from iterators in PSTL tests [PR90276]
@ 2024-02-02 10:28 Jonathan Wakely
  2024-02-02 10:28 ` [committed 2/2] libstdc++: Fix invalid order in PSTL inplace_merge test [PR90276] Jonathan Wakely
  0 siblings, 1 reply; 2+ messages in thread
From: Jonathan Wakely @ 2024-02-02 10:28 UTC (permalink / raw)
  To: libstdc++, gcc-patches; +Cc: François Dumont

Tested x86_64-linux. Pushed to trunk.

-- >8 --

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.
---
 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 ed6d48b9471..e35084eabb2 100644
--- a/libstdc++-v3/testsuite/util/pstl/test_utils.h
+++ b/libstdc++-v3/testsuite/util/pstl/test_utils.h
@@ -1083,18 +1083,18 @@ 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...);
     }
 };
 
-- 
2.43.0


^ permalink raw reply	[flat|nested] 2+ messages in thread

* [committed 2/2] libstdc++: Fix invalid order in PSTL inplace_merge test [PR90276]
  2024-02-02 10:28 [committed 1/2] libstdc++: Avoid reusing moved-from iterators in PSTL tests [PR90276] Jonathan Wakely
@ 2024-02-02 10:28 ` Jonathan Wakely
  0 siblings, 0 replies; 2+ messages in thread
From: Jonathan Wakely @ 2024-02-02 10:28 UTC (permalink / raw)
  To: libstdc++, gcc-patches; +Cc: François Dumont

Tested x86_64-linux. Pushed to trunk.

-- >8 --

This looks like a typo in the upstream test that causes a failure in
debug mode. It has been reported upstream.

libstdc++-v3/ChangeLog:

	PR libstdc++/90276
	* testsuite/25_algorithms/pstl/alg_merge/inplace_merge.cc: Fix
	comparison function to use less-than instead of equality.
---
 .../testsuite/25_algorithms/pstl/alg_merge/inplace_merge.cc     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libstdc++-v3/testsuite/25_algorithms/pstl/alg_merge/inplace_merge.cc b/libstdc++-v3/testsuite/25_algorithms/pstl/alg_merge/inplace_merge.cc
index 576f22423b8..a9205553574 100644
--- a/libstdc++-v3/testsuite/25_algorithms/pstl/alg_merge/inplace_merge.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/pstl/alg_merge/inplace_merge.cc
@@ -160,7 +160,7 @@ main()
     test_by_type<MemoryChecker>(
         [](std::size_t idx){ return MemoryChecker{std::int32_t(idx * 2)}; },
         [](std::size_t idx){ return MemoryChecker{std::int32_t(idx * 2 + 1)}; },
-        [](const MemoryChecker& val1, const MemoryChecker& val2){ return val1.value() == val2.value(); });
+        [](const MemoryChecker& val1, const MemoryChecker& val2){ return val1.value() < val2.value(); });
     EXPECT_FALSE(MemoryChecker::alive_objects() < 0, "wrong effect from inplace_merge: number of ctors calls < num of dtors calls");
     EXPECT_FALSE(MemoryChecker::alive_objects() > 0, "wrong effect from inplace_merge: number of ctors calls > num of dtors calls");
 
-- 
2.43.0


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