Getting base name of the source file at compile time

I don't know of a direct way. You could use:

#line 1 "filename.c"

at the top of the source file to set the value of __FILE__, but I'm not sure that that's much better than hard coding it. or just using a #define to create your own macro.

Another option might be to pass the name from your Makefile using -D and $(shell basename $<)

Edit: If you use a #define or the -D option, you should create your own new name and not try to redefine __FILE__.

If you're using a make program, you should be able to munge the filename beforehand and pass it as a macro to gcc to be used in your program. For example, in your makefile, change the line:

file.o: file.c
    gcc -c -o file.o src/file.c

to:

file.o: src/file.c
    gcc "-DMYFILE=\"`basename $<`\"" -c -o file.o src/file.c

This will allow you to use MYFILE in your code instead of __FILE__.

The use of basename of the source file $< means you can use it in generalized rules such as .c.o. The following code illustrates how it works. First, a makefile:

mainprog: main.o makefile
    gcc -o mainprog main.o

main.o: src/main.c makefile
    gcc "-DMYFILE=\"`basename $<`\"" -c -o main.o src/main.c

Then a file in a subdirectory, src/main.c:

#include <stdio.h>

int main (int argc, char *argv[]) {
    printf ("file = %s\n", MYFILE);
    return 0;
}

Finally, a transcript showing it running:

pax:~$ mainprog
file = main.c

Note the file = line which contains only the base name of the file, not the directory name as well.