Re: How to speed up 'automake'

[Jan Engelhardt]

On Monday 2022-05-02 15:31, Jan Engelhardt wrote:
>> If empty files are ok (assuming they are needed at all), can they be produced
>> with a minimum number of executions of a 'touch' command?
>
>Better yet, they can be produced with the ">>" shell builtin, skipping
>spawning the touch program. (We need to use >>, because > truncates,
>and configure does not truncate deps files for a good reason - doing
>so would be like `make clean`)

touch wasn't even used. but mv was, which should become redundant too.

(The use '>' with 'mv' may have to do with desires for atomicity
reasons when you do make -j)

diff --git a/lib/am/depend.am b/lib/am/depend.am
index ecc6180a6..3a493c3de 100644
--- a/lib/am/depend.am
+++ b/lib/am/depend.am
@@ -18,7 +18,7 @@ am__mv = mv -f
 
 $(am__depfiles_remade):
        @$(MKDIR_P) $(@D)
-       @echo '# dummy' >$@-t && $(am__mv) $@-t $@
+       @: >>$@
 
 am--depfiles: $(am__depfiles_remade)
 .PHONY: am--depfiles