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Re: What is the purpose of parser-built?
From: |
Peng Yu |
Subject: |
Re: What is the purpose of parser-built? |
Date: |
Wed, 6 Feb 2019 17:05:20 -0600 |
On Wed, Feb 6, 2019 at 4:49 PM Eric Blake <eblake@redhat.com> wrote:
>
> On 2/6/19 4:18 PM, Peng Yu wrote:
> > Hi,
> >
> > I deleted the file parser-built, and bash still compiles and an empty
> > parser-built file will be generated upon compilation. What is the
> > purpose of this file? Should it be deleted? Thanks.
> parser-built is a witness that $(YACC) was run, even if the timestamps
> did not change (because the generated file did not change compared to
> last time). It exists in the file system so as to let make compute
> timestamp dependencies where we know the parser is up-to-date, even
> though the actual file we depend on has a timestamp that does NOT change
> (because we intentionally don't override it when there is no
> difference), all in order to minimize the time spent rebuilding the
> project when making a tweak to parse.y (for example, being able to tell
> the difference between a minor edit that changes a comment but not the
> generated parser, vs. a major edit that requires rebuilding other files
> to pick up the changes implied by the changed parser).
I don't get the point. Should parser-built be deleted? If bash can be
compiled without it, why put it in the source tar.gz file?
--
Regards,
Peng