Re: [PATCH] Support building development version without git

[Ethan M. <eam...@gm...>]

On Tuesday, 30 June 2020 16:03:22 PDT Henri Menke wrote:
> Currently building the development version requires git to be installed
> to fetch the `last modified' date from the commit information.  This is
> okay when building from a git clone, but fails when downloading a
> snapshot that does not contain the .git directory.

Yeah, that has been a problem.
Thanks for looking at this.

> To this end, I implemented a fallback which just uses the current date
> if git is not available.  

If you are building from a snapshot, the correct date should be the
date of the snapshot.  I don't know how to do that.  Do you?

	Ethan

> The old version had the advantage that
> `timestamp.h' would only be rebuilt when changing the git branch.  If
> git is not available, this logic fails of course.  Instead I made
> `timestamp.h' a phony target, i.e. it will be rebuilt unconditionally
> every time.  The disadvantage here is that this will also trigger a
> rebuild of every file that depends on `timestamp.h' but as far as I can
> see this is only `version.c'.
> ---
>  src/Makefile.am | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/src/Makefile.am b/src/Makefile.am
> index 1b0d8136e..7eca23cfa 100644
> --- a/src/Makefile.am
> +++ b/src/Makefile.am
> @@ -107,12 +107,12 @@ endif
>  
>  DISTCLEANFILES = timestamp.h
>  BUILT_SOURCES = timestamp.h
> -git_current := $(shell cut -c6- $(top_srcdir)/.git/HEAD)
> -timestamp.h: $(top_srcdir)/.git/${git_current} Makefile
> +.PHONY: timestamp.h
> +timestamp.h: Makefile
>  	@echo Making $@
>  	@echo "#ifndef GNUPLOT_TIMEBASE_H_INCLUDED" >$@t
>  	@echo "#define GNUPLOT_TIMEBASE_H_INCLUDED" >>$@t
> -	@echo "const char gnuplot_date[] = \"`git --git-dir '$(top_srcdir)/.git' log -1 --format=%ci | cut -b-11`\";" >>$@t
> +	@echo "const char gnuplot_date[] = \"`git --git-dir '$(top_srcdir)/.git' log -1 --format=%cs || date +'%Y-%m-%d'`\";" >>$@t
>  	@echo "#endif /* GNUPLOT_TIMEBASE_H_INCLUDED */" >> $@t
>  	@if cmp -s $@ $@t; then rm -f $@t; else mv $@t $@; fi
>  
>