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

Måns Rullgård mans
Tue Oct 27 23:41:44 CET 2009


Adam Strzelecki <ono at java.pl> writes:

> Lately I was obliged to make sure one of my multiplatform projects
> using FFmpeg compiles well on MinGW. Then I found out the "make" takes
> AGES in MSYS+MinGW. All because "include *.dep" causes implicit rules
> on .d files (checkout "make -d"), while file testing on UNIX is pretty
> cheap, it's not in Windoze.
> So here's a cure that really speeds up "make" in Windoze, and of
> course on other systems, however the speed up not so significant on
> UNIX.
> (1) Puts all dependency files to .PHONY, which cancels implicit rules

There is no rule defined for .d files, nor is there a builtin rule, so
this does nothing.

> (2) Define empty rules for Makefile, common.mak, subdir.mak &
> config.mak that cancels implicit rules also for those files

Why?

> (3) Define empty rules for .svn/entries & version.sh... as above

Why?

Whatever you think you saw, this patch had nothing to do with it.

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



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