[FFmpeg-devel] [PATCH] Speedup make removing implicit rules for makefiles and dependencies (cure for slow "make" in MSYS+MinGW)

Måns Rullgård mans
Wed Oct 28 00:33:26 CET 2009


Adam Strzelecki <ono at java.pl> writes:

>> There is no rule defined for .d files, nor is there a builtin rule, so
>> this does nothing.
>
> You are wrong. "include inexistent.d" (which is case where some .d not
> yet exist) cause make try many implicit rules and execute many
> (hundreds) of file checks.

We never try to include .d files that don't exist.

> Just check "make -d" on configures FFmpeg, you'll see what I mean.

make -d spews out lots of junk.  That's not news.

If the builtin rules are slowing down make on your system, you can run
"make -r" to run without them.  Your ugly hacks have no place in our
makefiles, and they only disable a tiny fraction of the builtin rules
anyway.

-- 
M?ns Rullg?rd
mans at mansr.com



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