Re: Compiling my 1st GTK+ program

[Todd Fisher <taf2 lehigh edu>]

Maya wrote:

> OK, I have a very simple program that goes as follows:
> ------------ base.c ---------------------
> #include <gtk/gtk.h>
>
> int main( int   argc, char *argv[] ){
>    GtkWidget *window;
>    gtk_init (&argc, &argv);
>    window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
>    gtk_widget_show  (window);
>    gtk_main ();
>    return 0;
> }
> -------------- eof -----------------------
>
>
>
> With the help of Todd and the litle bit I could find about writing Makefiles I wrote the following script to 
> compile the above program:
> ----------- Makefile  ----------
> # Compiler name
> CC=gcc
>
> # Flagas
> CFLAGS = -Wall -g -ansi `pkg-config --cflags --libs gtk+-2.0`
> LDLIBS = `pkg-config --libs gtk+-2.0`
>
> # Variables
> OBJS = base.o  
> EXEC = Base
>
> #Application name
> all: $(OBJS)
>    $(CC) $(LDLIBS) $(OBJS) -o $(EXEC)
>
> # Thanks tod :)
> $(EXEC): $(OBJS)
>
> base.o: 
>    $(CC) $(CFLAGS) -c base.c
>
> clean:
>    rm -f $(OBJS)
>    rm -f $(EXEC)
>
> PHONY: clean
> --------- eof -------------
>
> The program compiles and creates a 'base.o' file, but I get the following error:
>
> base.o(.text+0x44): In function `main':
> /home/Jamil/dev/jme/tmp/GTK_TST/base.c:7: undefined reference to `_gtk_init_abi_check'
> base.o(.text+0x50):/home/Jamil/dev/jme/tmp/GTK_TST/base.c:9: undefined reference to `_gtk_window_new'
> base.o(.text+0x5e):/home/Jamil/dev/jme/tmp/GTK_TST/base.c:10: undefined reference to `_gtk_widget_show'
> base.o(.text+0x63):/home/Jamil/dev/jme/tmp/GTK_TST/base.c:12: undefined reference to `_gtk_main'
> collect2: ld returned 1 exit status
> make: *** [all] Error 1
>
>
> I am not an expert, but it looks like the linker is having problems finding the gtk+ libraries, am I right? 
> It is irrelevant if I am right or not; I would not know how to fix problem anyway!
> Any help would be very much appreciated.
>
> Thanks Todd for the help with the Makefile, I really don't know much about Makefiles, but little by little 
> all this stuff is falling into place
>
>  
Maya,

# Compiler name
CC=gcc # usually not needed

CFLAGS = -Wall -g -ansi `pkg-config --cflags --libs gtk+-2.0`  # compile time flags for .c files use CXXFLAGS 
for .cc or .cpp
LDFLAGS = `pkg-config --libs gtk+-2.0`  # link time flags that get used during the link step

OBJS = base.o  # you can list all the object files, which have corresponding .c,.cpp,and .cc files here
EXEC = base  # by keeping this name the same as at least one of the object files listed above you can make 
use of implicit rules

# all lets you list 'all' the targets you want to be run when you type 'make'
all: $(EXEC)

# This is all you need it will derive the rest for you
$(EXEC): $(OBJS)

clean:
   rm -f $(EXEC) $(OBJS) # this can all be on the same line

PHONY: clean # usually not needed