Question

我有一个makefile，它应该编译一组使用<pthread.h>库的C文件。尽管makefile在我以前的Linux安装上运行，但我现在无法运行它。谁能帮我这个？

CC=gcc
CFLAGS=-c -std=c99
LDFLAGS= -lpthread
SOURCES=pc_0.c stak.h
OBJECTS=$(SOURCES:.c=.o)
EXECUTABLE=pcths

all: $(SOURCES) $(EXECUTABLE)   
$(EXECUTABLE): $(OBJECTS) 
    $(CC) $(LDFLAGS) $(OBJECTS) -o $@

.c.o:
    $(CC) $< -o $@ $(CFLAGS)
clean:
    rm -f *.o core

以下是我在shell提示符下输入“make”时收到的错误消息。

gcc pc_0.c -o pc_0.o -c -std=c99
pc_0.c: In function ‘main’:
pc_0.c:25:2: warning: passing argument 3 of ‘pthread_create’ from incompatible pointer type [enabled by default]
/usr/include/pthread.h:225:12: note: expected ‘void * (*)(void *)’ but argument is of type ‘void (*)()’
pc_0.c:29:2: warning: passing argument 3 of ‘pthread_create’ from incompatible pointer type [enabled by default]
/usr/include/pthread.h:225:12: note: expected ‘void * (*)(void *)’ but argument is of type ‘void (*)()’
pc_0.c:33:2: warning: passing argument 3 of ‘pthread_create’ from incompatible pointer type [enabled by default]
/usr/include/pthread.h:225:12: note: expected ‘void * (*)(void *)’ but argument is of type ‘void (*)()’
gcc -lpthread pc_0.o stak.h -o pcths
pc_0.o: In function `main':
pc_0.c:(.text+0x100): undefined reference to `pthread_create'
pc_0.c:(.text+0x15d): undefined reference to `pthread_create'
pc_0.c:(.text+0x1ba): undefined reference to `pthread_create'
pc_0.c:(.text+0x206): undefined reference to `pthread_join'
pc_0.c:(.text+0x21a): undefined reference to `pthread_join'
pc_0.c:(.text+0x22e): undefined reference to `pthread_join'
collect2: ld returned 1 exit status
make: *** [pcths] Error 1

但是，如果我手动运行以下说明，则会编译源：

cc pc_0.c -o pc_0.o -c -std=c99
cc pc_0.o -o pcths -lpthread

Answer 1

不确定它有多重要，但我总是在变量分配

附近添加

Answer 2

将-lpthread放在命令行的末尾，在目标文件之后，需要来自libthread.[a|so]的符号

当GNU ld（和其他链接器）解析未定义的引用时，它仅在对象文件和库中查找符号定义，该文件和库跟随包含所述引用的对象。

Makefile返回错误

2 个答案: