如何使用gcc检查动态库中符号的完整性

Check out the linker option "-z defs" / "--no-undefined". When creating a shared object, it will cause the link to fail if there are unresolved symbols.

 

If you are using gcc to invoke the linker, you'll use the compiler -Wl option to pass the option to the linker:

gcc -shared ... -Wl,-z,defs
As an example, consider the following file:

#include <stdio.h>

void forgot_to_define(FILE *fp);

void doit(const char *filename)

{   

         FILE *fp = fopen(filename, "r");   

         if (fp != NULL)   

         {       

              forgot_to_define(fp);       

              fclose(fp);   

         }

}
Now, if you build that into a shared object, it will succeed:

 

> gcc -shared -fPIC -o libsilly.so silly.c && echo succeeded || echo failedsucceeded
But if you add -z defs, the link will fail and tell you about your missing symbol:

 

> gcc -shared -fPIC -o libsilly.so silly.c -Wl,-z,defs && echo succeeded || echo failed/tmp/cccIwwbn.o: In function `doit':silly.c:(.text+0x2c): undefined reference to `forgot_to_define'collect2: ld returned 1 exit statusfailed