Question

Here’s the makefile:

makefile.win

CC=gcc
CFLAGS=-Wall -ID:\dev\include -LD:\dev\lib -LD:\dev\bin
LIBS=-l mingw32 -l SDLmain -l SDL
TARGET=-mwindows
EXECUTABLE=main.exe

all:
    $(CC) $(CFLAGS) $(LIBS) $(TARGET) main.c -o $(EXECUTABLE)

clean:
    rm *o

(libSDL and libSDLmain are in D:\dev\lib. SDL.dll is in D:\dev\bin.)

and here’s the code

#include <SDL/SDL.h>

int main(int argc, char* argv[])
{
    if (SDL_Init(SDL_INIT_EVERYTHING) < 0)
        printf("Could not initialize!");

    SDL_Surface* screen = SDL_SetVideoMode(640, 480, 16, SDL_HWSURFACE|SDL_DOUBLEBUF);
    if (!screen) printf("Could not load video!");

    int done = 0;
    SDL_Event event;

    while(!done)
    {
        while(SDL_PollEvent(&event))
        {
            if (event.type == SDL_QUIT)
                done = 1;
        }

        SDL_Flip(screen);
    }

    SDL_FreeSurface(screen);
    printf("Exited cleanly");

    return 0;
}

I build it with this command:

mingw32-make -f makefile.win

and mingw32-make translates the makefile into:

gcc -Wall -ID:\dev\include -LD:\dev\lib -LD:\dev\bin -l mingw32 -l SDLmain -l SD
L -mwindows main.c -o main.exe

which is alright.

But then I get all thes charming errors:

main.c:(.text+0x42): undefined reference to `SDL_SetVideoMode'
main.c:(.text+0x7c): undefined reference to `SDL_PollEvent'
main.c:(.text+0x8b): undefined reference to `SDL_Flip'
main.c:(.text+0x9c): undefined reference to `SDL_FreeSurface'
collect2: ld returned 1 exit status
mingw32-make: *** [all] Error 1

So, since I’m linking with mingw32, SDL and SDLmain. And I am adding the directory to the SDL headers. Why am I getting the errors?

Answer 1

You should place the library flags as last:

gcc -o main.exe main.c -lSDL -lSDLmain -lmingw32