Pre-build step in makefile

Question

How can I run a script, which must execute before all other makefile commands? And it will be nice (but not mandatory) to the script is not executed if there is nothing to build

Answer 1

You could add a special target to your Makefile and have all your build rules depend on that:

run-script:
    myscript

.o.c: run-script
     $(CC) $(CFLAGS) -o $@ $<

.o.S: run-script
     $(AS) $(AFLAGS) -o $@ $<

Depending on what your script actually does, putting it to run once in a stage before the Makefile (configure stage in autoconf terms) could make even more sense (and be less work).