Re: [Automake-ng] [PATCH 1/4] [ng] compiling: implement VPATH rewrites using GNU make primitives

[Stefano Lattarini]

Hi Jim.

On 02/01/2012 10:50 AM, Jim Meyering wrote:
> Stefano Lattarini wrote:
>> This will shave off extra forks from compilation rules.  No semantic
>> change is expected from this commit.  Suggestion from Eric Bake.
>>
>> * lib/am/depend2.am (am__vpath_rewrite): New internal macro,
>> implements VPATH rewrites only using GNU make primitives.
>> Use it in several compilation rules.
>> ---
>>  lib/am/depend2.am |   25 ++++++++++++++-----------
>>  1 files changed, 14 insertions(+), 11 deletions(-)
>>
>> diff --git a/lib/am/depend2.am b/lib/am/depend2.am
> ...
>> +## Emulate VPATH rewrites.  This only uses GNU make primitives, which
>> +## allows us to avoid extra forks.
>> +am__vpath_rewrite = $(firstword $(wildcard $(strip $(1))) $(srcdir)/$(strip 
>> $(1)))
> 
> Nice change.
> At least when it's easy, as it is here, please try to limit
> line length to 79 or 80:
> 
> am__vpath_rewrite = \
>   $(firstword $(wildcard $(strip $(1))) $(srcdir)/$(strip $(1)))
>
Good point.  Still, since the better line wrapping you proposed is already
implemented later in [PATCH 3/4] (when we move the $(am__vpath_rewrite)
definition from depend2.am to header-vars.am), could we just keep this patch
as-is, to avoid unnecessary rebase pains?

Thanks,
  Stefano