pthreadsはシステムで動作します:
$ gcc -o what what.c
/tmp/ccI6m52b.o: In function `main':
what.c:(.text+0x37): undefined reference to `pthread_create'
what.c:(.text+0x48): undefined reference to `pthread_join'
collect2: error: ld returned 1 exit status
$ gcc -pthread -o what what.c
$ ./what
In the thread.
ただし、cmake
を次のベアボーンCMakeLists.txt
で実行すると:
cmake_minimum_required(VERSION 2.8.6)
FIND_PACKAGE (Threads)
出力は次のとおりです。
-- Could NOT find Threads (missing: Threads_FOUND)
何が得られますか?エラーログの状態:
/usr/bin/cc -std=c11 -D_GNU_SOURCE -Wall -Wextra -Wpointer-arith -Wundef -Wvla -Wwrite-strings -Werror -Wno-error=extra -Wno-error=deprecated-declarations -Wno-error=sign-compare -Wno-error=strict-aliasing -Wno-error=type-limits -Wno-unused-parameter -Wno-error=unused-variable -Wno-error=undef -Wno-error=uninitialized -Wlogical-op -Wno-error=maybe-uninitialized -Waggregate-return -Wnested-externs -Wold-style-definition -Wstrict-prototypes -march=native -o CMakeFiles/cmTryCompileExec2533162744.dir/CheckIncludeFiles.c.o -c /mnt/shared/fooproj/build/release/CMakeFiles/CMakeTmp/CheckIncludeFiles.c
/mnt/shared/fooproj/build/release/CMakeFiles/CMakeTmp/CheckIncludeFiles.c:5:5:
error: function declaration isn’t a prototype [-Werror=strict-prototypes]
int main(){return 0;}
^
/mnt/shared/fooproj/build/release/CMakeFiles/CMakeTmp/CheckIncludeFiles.c:
In function ‘main’:
/mnt/shared/fooproj/build/release/CMakeFiles/CMakeTmp/CheckIncludeFiles.c:5:5:
error: old-style function definition [-Werror=old-style-definition]
cc1: all warnings being treated as errors
[...]
Source:
/* */
#include <pthread.h>
int main(){return 0;}
この質問に答えました StackOverflowで 。
簡単な答え:それは私が報告し、パッチを提供したCMakeのバグです。