共享库和ldflags的“未定义的引用”错误

当尝试使用make在QEMU中编译我的代码时,在链接阶段我得到一个未定义的引用错误. Afaik配置参数是正确的,因此共享库应该正确用于链接,但也许我忽略了一些东西.

任何帮助,将不胜感激！

以下是我已收集的大量其他信息：

解决方案：见Zach’s answer

我现在通过将LIBS = -lcity添加到Makefile.target文件来管理它.

谢谢大家！

更新：

使V = 1输出：

cc -Werror -fPIE -DPIE -m64 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64
-D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wall -Wundef
-Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -I/home/user/cityhash
-Wendif-labels -Wmissing-include-dirs -Wempty-body -Wnested-externs
-Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers
-Wold-style-declaration -Wold-style-definition -Wtype-limits
-fstack-protector-all -I/usr/include/p11-kit-1     -I/usr/include/libpng12
-I/usr/include/pixman-1     -I../linux-headers -I..
-I/home/user/qemu/target-i386 -DNEED_CPU_H -I/home/user/qemu/include -pthread
-I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include   -O2
-D_FORTIFY_SOURCE=2 -g  -Wl,--warn-common -Wl,-z,relro -Wl,now -pie -m64 -g
-L/home/user/lib -Wl,-rpath=/home/user/lib -lcity -o qemu-system-x86_64 [… all
*.o files … ] ../libqemuutil.a ../libqemustub.a   -lrt -pthread -lgthread-2.0
-lrt -lglib-2.0    -lutil -lrbd -lrados -lbluetooth   -lcurl   -lncurses -ltinfo
-lbrlapi  -luuid -lpng12   -ljpeg -lsasl2 -lgnutls   -lSDL   -lX11  -lz -laio
-lpixman-1   -lm

接下来是我在下面写的正常错误输出(除了LINK,在这种情况下缺少).

错误：

~/qemu$make
...
  LINK  x86_64-softmmu/qemu-system-x86_64
my_code.o: In function `function`:
/home/user/qemu/my_code.c:982: undefined reference to `CityHash64'
...
collect2: error: ld returned 1 exit status
make[1]: *** [qemu-system-x86_64] Error 1
make: *** [subdir-x86_64-softmmu] Error 2

配置参数：

./configure [...] 
    --extra-cflags='-I/home/user/cityhash' 
    --extra-ldflags='-L/home/user/lib -Wl,-rpath=/home/user/lib -lcity'

文件夹结构：

~
├─ cityhash/
│  ├─ city.h
│  └─ ...
├─ lib/
│  ├─ libcity.so
│  └─ ...
└─ qemu/

标题包含和函数用法(my_code.c)：

[...]
 11  #include "city.h"

982  hash = CityHash64(buf,len);
[...]

共享库的Nm输出：

~/lib$nm libcity.so
[...]
0000000000000fdc T CityHash64
[...]

make期间的Strace输出：

~/qemu$strace -f -o ../strace.out -- make
[...]
16111 stat("/home/user/lib/libcity.so",{st_mode=S_IFREG|0755,st_size=18468,...}) = 0
16111 open("/home/user/lib/libcity.so",O_RDONLY) = 7
16111 fcntl(7,F_GETFD)                 = 0
16111 fcntl(7,F_SETFD,FD_CLOEXEC)     = 0
16111 fstat(7,...}) = 0
16111 mmap(NULL,4096,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANONYMOUS,-1,0) = 0x2aaaaaad9000
16111 lseek(7,SEEK_SET)             = 0
16111 read(7,"177ELF2113>1`7"...,4096) = 4096
16111 lseek(7,SEEK_SET)          = 4096
16111 lseek(7,SEEK_SET)          = 4096
16111 brk(0x2129000)                    = 0x2129000
16111 lseek(7,12288,SEEK_SET)         = 12288
16111 read(7,"9232%252413642412E232412>2324120324"...,16384,SEEK_SET)         = 16384
16111 lseek(7,8192,SEEK_SET)          = 8192
16111 read(7,"62233f710$3141314354377377210A16202062Cr"...,SEEK_SET)         = 12288
16111 lseek(7,SEEK_SET)          = 4096
[...]
16111 close(7)                          = 0
[...]

-g -L/home/user/lib -Wl,-rpath=/home/user/lib -lcity -o qemu-system-x86_64

[... all *.o files ...] ../libqemuutil.a ../libqemustub.a 
-lrt -pthread -lgthread2.0 [... more libraries ...]