[Bug libstdc++/88996] Implement P0439R0 - Make std::memory_order a scoped enumeration.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88996 emsr at gcc dot gnu.org changed: What|Removed |Added Status|NEW |RESOLVED Resolution|--- |FIXED --- Comment #8 from emsr at gcc dot gnu.org --- This was committed 269372.
[Bug libstdc++/88996] Implement P0439R0 - Make std::memory_order a scoped enumeration.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88996 --- Comment #7 from emsr at gcc dot gnu.org --- Author: emsr Date: Mon Mar 4 20:11:14 2019 New Revision: 269372 URL: https://gcc.gnu.org/viewcvs?rev=269372=gcc=rev Log: 2019-03-04 Edward Smith-Rowland <3dw...@verizon.net> PR libstdc++/88996 Implement P0439R0 Make std::memory_order a scoped enumeration. * include/bits/atomic_base.h: For C++20 make memory_order a scoped enum, add variables for the old enumerators. Adjust calls. * testsuite/29_atomics/headers/atomic/types_std_c++2a.cc: New test. * testsuite/29_atomics/headers/atomic/types_std_c++2a_neg.cc: New test. Added: trunk/libstdc++-v3/testsuite/29_atomics/headers/atomic/types_std_c++2a.cc trunk/libstdc++-v3/testsuite/29_atomics/headers/atomic/types_std_c++2a_neg.cc Modified: trunk/libstdc++-v3/ChangeLog trunk/libstdc++-v3/include/bits/atomic_base.h
[Bug libstdc++/88996] Implement P0439R0 - Make std::memory_order a scoped enumeration.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88996 --- Comment #6 from emsr at gcc dot gnu.org --- Created attachment 45502 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=45502=edit New patch, C++20 only, several fixes, no memory_order ops. Retesting.
[Bug libstdc++/88996] Implement P0439R0 - Make std::memory_order a scoped enumeration.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88996 --- Comment #5 from emsr at gcc dot gnu.org --- I was a bit surprised I "needed" these. There are apparently some uses of these. I'll roll back and show you... /home/ed/obj/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/atomic_base.h:104:7: error: no match for ‘operator|’ (operand types are ‘std::memory_order’ and ‘std::memory_order’) 103 | return memory_order(__cmpexch_failure_order2(__m & __memory_order_mask) | ~~~ | | | std::memory_order 104 | | (__m & __memory_order_modifier_mask)); | ^ | | | std::memory_order Ok, I'm casting: | __memory_order_modifier(__m & __memory_order_modifier_mask)); This will work without the operators. Those are sequatial flags. Killed the ops, fix some more sadness and retest.
[Bug libstdc++/88996] Implement P0439R0 - Make std::memory_order a scoped enumeration.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88996
--- Comment #4 from Jonathan Wakely ---
+ inline constexpr memory_order
+ operator&(memory_order __m1, memory_order __m2)
+ { return memory_order(int(__m1) & int(__m2)); }
+
+ inline constexpr memory_order
+ operator|(memory_order __m1, memory_order __m2)
+ { return memory_order(int(__m1) | int(__m2)); }
What are these operators for? One of the main points of P0439 was that this
isn't a bitmask type, and combining the values doesn't make sense. Quoting the
paper:
> a scoped enumeration is more strongly typed, disallowing implicit
> conversion to integers, and preventing nonsensical expressions such as
> memory_order_acquire|memory_order_release (which could be mistakenly
> assumed to be equivalent to memory_order_acq_rel) or ~memory_order_relaxed.
[Bug libstdc++/88996] Implement P0439R0 - Make std::memory_order a scoped enumeration.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88996 Jonathan Wakely changed: What|Removed |Added Status|UNCONFIRMED |NEW Last reconfirmed||2019-01-22 Ever confirmed|0 |1 --- Comment #3 from Jonathan Wakely --- The ABI says the mangling is the same for scoped and unscoped enumeration types. There are some corner cases with decltype expressions in function template declarations, where the enumerator names show up, but I don't expect them to happen in real code. I'm not sure if we want to do this for older standards though, it wasn't a DR.
[Bug libstdc++/88996] Implement P0439R0 - Make std::memory_order a scoped enumeration.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88996 --- Comment #2 from emsr at gcc dot gnu.org --- Still testing BTW.
[Bug libstdc++/88996] Implement P0439R0 - Make std::memory_order a scoped enumeration.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88996 emsr at gcc dot gnu.org changed: What|Removed |Added CC||emsr at gcc dot gnu.org --- Comment #1 from emsr at gcc dot gnu.org --- Created attachment 45499 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=45499=edit Patch that just does the thing for C++11 onwards. I did ed@bad-horse:~/bin$ nm lib64/libstdc++.so | grep memory_order 000a9120 T _ZNSt9__atomic011atomic_flag12test_and_setESt12memory_order 000a9170 T _ZNSt9__atomic011atomic_flag5clearESt12memory_order 000a9120 T _ZNVSt9__atomic011atomic_flag12test_and_setESt12memory_order@@GLIBCXX_3.4.11 and ed@bad-horse:~/bin$ nm lib32/libstdc++.so | grep memory_order 0008ae00 T _ZNSt9__atomic011atomic_flag12test_and_setESt12memory_order 0008ae70 T _ZNSt9__atomic011atomic_flag5clearESt12memory_order 0008ae00 T _ZNVSt9__atomic011atomic_flag12test_and_setESt12memory_order@@GLIBCXX_3.4.11 0008ae70 T _ZNVSt9__atomic011atomic_flag5clearESt12memory_order@@GLIBCXX_3.4.11 on x96_64-linux. This is what all teh abi files have. We'll need to check this on all the targets.
