筆記 undefined reference to `mq_open' under Ubuntu 12

今天在編譯開源程式時遇到了這個問題。心想一般開源的程式怎會有這種錯誤。莫非是我函式庫安裝不完整…

gcc -pthread -lrt -o"FreeRTOS_Posix"  ./main.o  ./ParTest/ParTest.o  ./FreeRTOS_Kernel/croutine.o ./FreeRTOS_Kernel/list.o ./FreeRTOS_Kernel/queue.o ./FreeRTOS_Kernel/tasks.o  ./FreeRTOS_Kernel/portable/MemMang/heap_3.o  ./FreeRTOS_Kernel/portable/GCC/Posix/port.o  ./FileIO/fileIO.o  ./Common_Demo/Minimal/GenQTest.o ./Common_Demo/Minimal/QPeek.o ./Common_Demo/Minimal/blocktim.o ./Common_Demo/Minimal/countsem.o ./Common_Demo/Minimal/crflash.o ./Common_Demo/Minimal/crhook.o ./Common_Demo/Minimal/recmutex.o  ./Common_Demo/Full/BlockQ.o ./Common_Demo/Full/PollQ.o ./Common_Demo/Full/death.o ./Common_Demo/Full/dynamic.o ./Common_Demo/Full/events.o ./Common_Demo/Full/flash.o ./Common_Demo/Full/flop.o ./Common_Demo/Full/integer.o ./Common_Demo/Full/print.o ./Common_Demo/Full/semtest.o  ./AsyncIO/AsyncIO.o ./AsyncIO/AsyncIOSerial.o ./AsyncIO/AsyncIOSocket.o ./AsyncIO/PosixMessageQueueIPC.o
./AsyncIO/PosixMessageQueueIPC.o: In function `xPosixIPCOpen':
/home/warren/src/Posix_GCC_Simulator/FreeRTOS_Posix/Debug/../AsyncIO/PosixMessageQueueIPC.c:44: undefined reference to `mq_open'
/home/warren/src/Posix_GCC_Simulator/FreeRTOS_Posix/Debug/../AsyncIO/PosixMessageQueueIPC.c:47: undefined reference to `mq_unlink'
/home/warren/src/Posix_GCC_Simulator/FreeRTOS_Posix/Debug/../AsyncIO/PosixMessageQueueIPC.c:85: undefined reference to `mq_notify'

觀察需聯結的library rt已寫在 -lrt。上網查了一下：

把整個指令改寫成如下就可以了：

gcc -pthread -o"FreeRTOS_Posix"  ./main.o  ./ParTest/ParTest.o  ./FreeRTOS_Kernel/croutine.o ./FreeRTOS_Kernel/list.o ./FreeRTOS_Kernel/queue.o ./FreeRTOS_Kernel/tasks.o  ./FreeRTOS_Kernel/portable/MemMang/heap_3.o  ./FreeRTOS_Kernel/portable/GCC/Posix/port.o  ./FileIO/fileIO.o  ./Common_Demo/Minimal/GenQTest.o ./Common_Demo/Minimal/QPeek.o ./Common_Demo/Minimal/blocktim.o ./Common_Demo/Minimal/countsem.o ./Common_Demo/Minimal/crflash.o ./Common_Demo/Minimal/crhook.o ./Common_Demo/Minimal/recmutex.o  ./Common_Demo/Full/BlockQ.o ./Common_Demo/Full/PollQ.o ./Common_Demo/Full/death.o ./Common_Demo/Full/dynamic.o ./Common_Demo/Full/events.o ./Common_Demo/Full/flash.o ./Common_Demo/Full/flop.o ./Common_Demo/Full/integer.o ./Common_Demo/Full/print.o ./Common_Demo/Full/semtest.o  ./AsyncIO/AsyncIO.o ./AsyncIO/AsyncIOSerial.o ./AsyncIO/AsyncIOSocket.o ./AsyncIO/PosixMessageQueueIPC.o -lrt

 問題有些特別，在此筆記一下。下次相同的錯誤，也許比照辦理試試。