GCC dependency generation for a different output directory

Question

I\'m using GCC to generate a dependency file, but my build rules put the output into a subdirectory. Is there a way to tell GCC to put my subdirectory prefix in the dependency f

Answer 1

You may like this briefer version of Don McCaughey's answer:

SRCS = \
    main.c \
    foo.c \
    stuff/bar.c

DEPS = $(SRCS:.c=.d)

Add -include $(DEPS) note the - prefix, which silences errors if the .d files don't yet exist.

There's no need for a separate pattern rule to generate the dependency files. Simply add -MD or -MMD to your normal compilation line, and the .d files get generated at the same time your source files are compiled. For example:

%.o: %.c
     gcc $(INCLUDE) -MMD -c $< -o $@

# -MD can be used to generate a dependency output file as a side-effect of the compilation process.