努力编译简单的C程序（gcc）

Question

I have a very old C program and want to compile to Windows. So I try doing this:

gcc -DNO_GLIBC=1 sakide.c -o sakide.exe

and this returns:

\AppData\Local\Temp\ccx7khiy.o:sakide.c:(.text+0xa4): undefined reference to `ekiGetLibVersion'
\AppData\Local\Temp\ccx7khiy.o:sakide.c:(.text+0x6b6): undefined reference to `ekiGetLibVersion'
\AppData\Local\Temp\ccx7khiy.o:sakide.c:(.text+0x8ff): undefined reference to `ekiEncodeUrl'
\AppData\Local\Temp\ccx7khiy.o:sakide.c:(.text+0x954): undefined reference to `ekiDecodeUrl'
\AppData\Local\Temp\ccx7khiy.o:sakide.c:(.text+0x993): undefined reference to `ekiDecodeUrl'
\AppData\Local\Temp\ccx7khiy.o:sakide.c:(.text+0xa62): undefined reference to `ekiGetKeyInfo'
collect2.exe: error: ld returned 1 exit status

This ekiGetLibVersion is in a .h file:

INT EKIAPI ekiGetLibVersion(char *outBuffer, LPINT outBufferSize);

and I also have a .dll name of it.

Ive never compiled anything with C though

Answer 1

You are getting linker errors.

You need to link the library (or object file) where those functions are defined.

Answer 2

On windows you cannot link against directly with the .dll, you have to link the import library, name .lib. For more information, refer:

On dynamic linking:

https://msdn.microsoft.com/en-us/library/windows/desktop/ms682592(v=vs.85).aspx

On implicit linking:

https://msdn.microsoft.com/en-us/library/d14wsce5.aspx

Answer 3

Undefined reference usually means the compiler has not seen a proper declaration for this variable. Did you include the header file (which defines this variable) in your C program ?

#include "header_file.h"