Support for QNX 7.1

[kheaactua]

Without specifying _XOPEN_SOURCE>=600, QNX 7.1 (ntoaarch64le) fails with:

/target/qnx7/usr/include/c++/v1/__threading_support: In function 'int std::__1::__libcpp_condvar_timedwait(std::__1::__libcpp_condvar_t*, std::__1::__libcpp_mutex_t*, timespec*)': /target/qnx7/usr/include/c++/v1/__threading_support:293:10: error: 'pthread_cond_timedwait' was not declared in this scope
   return pthread_cond_timedwait(__cv, __m, __ts);
          ^~~~~~~~~~~~~~~~~~~~~~
/target/qnx7/usr/include/c++/v1/__threading_support:293:10: note: suggested alternative: 'pthread_cond_wait'
   return pthread_cond_timedwait(__cv, __m, __ts);
          ^~~~~~~~~~~~~~~~~~~~~~
          pthread_cond_wait

[derekmauro]

Can you post the full error message? The part of the error message that you posted mentions pthread_cond_timedwait but I don't see how that is used by this file. It also seems weird that if this change is to fix pthread_cond_timedwait that the #define is going into a block guarded by #if defined(HAS_STRPTIME) && HAS_STRPTIME.

[kheaactua]

Can you post the full error message? The part of the error message that you posted mentions pthread_cond_timedwait but I don't see how that is used by this file. It also seems weird that if this change is to fix pthread_cond_timedwait that the #define is going into a block guarded by #if defined(HAS_STRPTIME) && HAS_STRPTIME.

Sure. This is from a conan build with a QNX profile I set up.

FAILED: CMakeFiles/cctz.dir/src/time_zone_format.cc.o
ccache /sdp710-qc/stage/host/linux/x86_64/usr/bin/q++ -Vaarch64 -Wc,-isysroot,/sdp710-qc/stage/target/qnx7 -lang-c++ -D_FILE_OFFSET_BITS=64 -D_FORTIFY_SOURCE=2 -D_LARGEFILE64_SOURCE -D_LARGEFILE_SOURCE -I/home/matt/.conan2/p/b/cctz69ae74031be22/b/src/include -Vgcc_ntoaarch64le  -O2 -g -DNDEBUG -std=gnu++17 -fPIC -fdiagnostics-color=always -march=armv8-a -mcpu=cortex-a57 -mtune=cortex-a57 -fstack-protector-strong -ftrapv -ffast-math -fno-unsafe-math-optimizations -Werror=return-type -Wp,-MD,CMakeFiles/cctz.dir/src/time_zone_format.cc.o.d -Wp,-MT,CMakeFiles/cctz.dir/src/time_zone_format.cc.o -Wp,-MF,CMakeFiles/cctz.dir/src/time_zone_format.cc.o.d -o CMakeFiles/cctz.dir/src/time_zone_format.cc.o -c /home/matt/.conan2/p/b/cctz69ae74031be22/b/src/src/time_zone_format.cc
In file included from /sdp710-qc/stage/target/qnx7/usr/include/c++/v1/__mutex_base:17,
                 from /sdp710-qc/stage/target/qnx7/usr/include/c++/v1/mutex:191,
                 from /sdp710-qc/stage/target/qnx7/usr/include/c++/v1/__locale:18,
                 from /sdp710-qc/stage/target/qnx7/usr/include/c++/v1/ios:216,
                 from /sdp710-qc/stage/target/qnx7/usr/include/c++/v1/ostream:138,
                 from /home/matt/.conan2/p/b/cctz69ae74031be22/b/src/include/cctz/civil_time_detail.h:20,
                 from /home/matt/.conan2/p/b/cctz69ae74031be22/b/src/include/cctz/civil_time.h:18,
                 from /home/matt/.conan2/p/b/cctz69ae74031be22/b/src/include/cctz/time_zone.h:30,
                 from /home/matt/.conan2/p/b/cctz69ae74031be22/b/src/src/time_zone_format.cc:27:
/sdp710-qc/stage/target/qnx7/usr/include/c++/v1/__threading_support: In function 'int std::__1::__libcpp_condvar_timedwait(std::__1::__libcpp_condvar_t*, std::__1::__libcpp_mutex_t*, timespec*)':
/sdp710-qc/stage/target/qnx7/usr/include/c++/v1/__threading_support:293:10: error: 'pthread_cond_timedwait' was not declared in this scope
   return pthread_cond_timedwait(__cv, __m, __ts);
          ^~~~~~~~~~~~~~~~~~~~~~
/sdp710-qc/stage/target/qnx7/usr/include/c++/v1/__threading_support:293:10: note: suggested alternative: 'pthread_cond_wait'
   return pthread_cond_timedwait(__cv, __m, __ts);
          ^~~~~~~~~~~~~~~~~~~~~~
          pthread_cond_wait

[kheaactua]

I'm reconsidering this PR. My toolchain used to define _QNX_SOURCE, which would also enable these pthread functions. I removed it from my toolchain based on the docs

There are additional variants of this option that enable vendor-specific compiler extensions: gnu99, gnu11, gnu++98, gnu++11, gnu++14, and gnu++17. If you use these variants, _QNX_SOURCE is defined automatically

As hard as I try, I can't show that this statement is in any way true.

Re-enabling this in a QNX toolchain (add_compile_definitions(_QNX_SOURCE)) solves this issue without any code change.