[PATCH] fix breakage from "libstdc++: Remove unnecessary uses of <utility>"
Hans-Peter Nilsson
hp@bitrange.com
Thu Jul 29 22:43:09 GMT 2021
Commit r12-2534 was incomplete and (by inspection derived from
an MMIX build) failing for targets without an insn for
compare_and_swap for pointer-size objects, IOW for targets for
which "ATOMIC_POINTER_LOCK_FREE != 2" is true:
x/gcc/libstdc++-v3/src/c++17/memory_resource.cc: In member function
'std::pmr::memory_resource*
std::pmr::{anonymous}::atomic_mem_res::exchange(std::pmr::memory_resource*)':
x/gcc/libstdc++-v3/src/c++17/memory_resource.cc:140:21: error:
'exchange' is not a member of 'std'
140 | return std::exchange(val, r);
| ^~~~~~~~
make[5]: *** [Makefile:577: memory_resource.lo] Error 1
make[5]: Leaving directory
'/home/hp/tmp/newmmix-r12-2579-p3/gccobj/mmix/libstdc++-v3/src/c++17'
This fix was derived from edits elsewhere in that patch.
Tested mmix-knuth-mmixware, restoring build (together with
target-reviving patches as MMIX is currently and at that commit
broken for target-specific reasons).
Ok to commit?
libstdc++-v3/:
* src/c++17/memory_resource.cc: Use __exchange instead
of std::exchange.
---
libstdc++-v3/src/c++17/memory_resource.cc | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/libstdc++-v3/src/c++17/memory_resource.cc b/libstdc++-v3/src/c++17/memory_resource.cc
index 5dfc29fc0ec8..1ba79903f870 100644
--- a/libstdc++-v3/src/c++17/memory_resource.cc
+++ b/libstdc++-v3/src/c++17/memory_resource.cc
@@ -29,7 +29,7 @@
#include <new>
#if ATOMIC_POINTER_LOCK_FREE != 2
# include <bits/std_mutex.h> // std::mutex, std::lock_guard
-# include <bits/move.h> // std::exchange
+# include <bits/move.h> // std::__exchange
#endif
namespace std _GLIBCXX_VISIBILITY(default)
@@ -117,7 +117,7 @@ namespace pmr
memory_resource* exchange(memory_resource* r)
{
lock_guard<mutex> lock(mx);
- return std::exchange(val, r);
+ return std::__exchange(val, r);
}
};
#else
@@ -137,7 +137,7 @@ namespace pmr
memory_resource* exchange(memory_resource* r)
{
- return std::exchange(val, r);
+ return std::__exchange(val, r);
}
};
#endif // ATOMIC_POINTER_LOCK_FREE == 2
--
2.20.1
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