Re: [PATCH resend] Makefile: Use computed header dependencies if the compiler supports it

Fredrik Kuivinen wrote:

Oh, I missed "--help". But for me gcc always exits with status code 0
when I give it "--help", regardless of what other flags I
provide. Therefore, I don't see how "--help" can be used to test for
support of -MMD.

Ah, my mistake.  Good catch.

Here is an updated patch. It avoids the ++empty.c file by giving "-x
c" to the compiler.

Much nicer, thanks!

It also avoids the auto-detection when
COMPUTE_HEADER_DEPENDENCIES is set

Unfortunately "ifdef" in Makefiles means "if nonempty", so the
overhead of detection is still there if I want to explicitly disable
COMPUTE_HEADER_DEPENDENCIES.  That's okay, since that overhead is
small.  So for what it's worth,

Acked-by: Jonathan Nieder <redacted>