2
Je compile un programme simple qui utilise la bibliothèque SDL2.
MWE (une version simplifiée de Lazy Foo's tutorial):Adaptation d'un Makefile pour inclure SDL2
// main.cpp
#include <SDL.h>
int main(int argc, char* args[])
{
SDL_Window* window = NULL;
SDL_Surface* screenSurface = NULL;
SDL_Init(SDL_INIT_VIDEO);
window = SDL_CreateWindow("The exciting white window", DL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 480, SDL_WINDOW_SHOWN);
screenSurface = SDL_GetWindowSurface(window);
SDL_FillRect(screenSurface, NULL, SDL_MapRGB(screenSurface->format, 0xFF, 0xFF, 0xFF));
SDL_UpdateWindowSurface(window);
SDL_Delay(2000);
SDL_DestroyWindow(window);
SDL_Quit();
return 0;
}
Je voudrais adapter le Makefile de this tutorial à manipuler.
C'est ce que j'ai essayé:
program_NAME := main
program_CXX_SRCS := $(wildcard *.cpp)
program_CXX_OBJS := ${program_CXX_SRCS:.cpp=.o}
program_OBJS := $(program_CXX_OBJS)
program_INCLUDE_DIRS := /usr/include/SDL2
program_LIBRARY_DIRS :=
program_LIBRARIES := SDL2
CPPFLAGS += $(foreach includedir,$(program_INCLUDE_DIRS),-I$(includedir))
LDFLAGS += $(foreach librarydir,$(program_LIBRARY_DIRS),-L$(librarydir))
LDFLAGS += $(foreach library,$(program_LIBRARIES),-l$(library))
.PHONY: all clean distclean
all: $(program_NAME)
$(program_NAME): $(program_OBJS)
$(LINK.cc) $(program_OBJS) -o $(program_NAME)
clean:
@- $(RM) $(program_NAME)
@- $(RM) $(program_OBJS)
distclean: clean
Cependant, je reçois plusieurs erreurs de l'éditeur de liens:
$ make
g++ -I/usr/include/SDL2 -c -o main.o main.cpp
g++ -I/usr/include/SDL2 -lSDL2 main.o -o myprogram
main.o: In function `main':
main.cpp:(.text+0x25): undefined reference to `SDL_Init'
main.cpp:(.text+0x4a): undefined reference to `SDL_CreateWindow'
main.cpp:(.text+0x5a): undefined reference to `SDL_GetWindowSurface'
main.cpp:(.text+0x7d): undefined reference to `SDL_MapRGB'
main.cpp:(.text+0x90): undefined reference to `SDL_FillRect'
main.cpp:(.text+0x9c): undefined reference to `SDL_UpdateWindowSurface'
main.cpp:(.text+0xa6): undefined reference to `SDL_Delay'
main.cpp:(.text+0xb2): undefined reference to `SDL_DestroyWindow'
main.cpp:(.text+0xb7): undefined reference to `SDL_Quit'
collect2: error: ld returned 1 exit status
Makefile:18: recipe for target 'myprogram' failed
make: *** [myprogram] Error 1
Je compris de this answer que l'ordre des arguments qui compte maintenant. Appel
$ g++ -I/usr/include/SDL2 -c -o main.o main.cpp
$ g++ main.o -lSDL2 -o main
directement à partir de la ligne de commande fonctionne.
Donc finalement ma question: quelle est la bonne façon d'adapter le Makefile? (Par "correct" je veux dire évitant le type de pièges que le tutoriel Makefile mentionne ci-dessus.)