diff mbox series

[XEN,2/5] docs: set DATE to SOURCE_DATE_EPOCH if available

Message ID 1ad1283052a580cbe7dbd7581b64f3cfd87cbf88.1735585600.git.maxi@daemonizer.de (mailing list archive)
State New
Headers show
Series Fixes for reproducible builds and other small fixes | expand

Commit Message

Maximilian Engelhardt Dec. 30, 2024, 9 p.m. UTC
Use the solution described in [1] to replace the call to the 'date'
command with a version that uses SOURCE_DATE_EPOCH if available. This
is needed for reproducible builds.

The -d "@..." syntax was introduced in GNU date about 2005 (but only
added to the docuemntation in 2011), so I assume a version supporting
this syntax is available, if SOURCE_DATE_EPOCH is defined. If
SOURCE_DATE_EPOCH is not defined, nothing changes with respect to the
current behavior.

[1] https://reproducible-builds.org/docs/source-date-epoch/

Signed-off-by: Maximilian Engelhardt <maxi@daemonizer.de>
---
 docs/Makefile | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

Comments

Andrew Cooper Dec. 30, 2024, 9:38 p.m. UTC | #1
On 30/12/2024 9:00 pm, Maximilian Engelhardt wrote:
> Use the solution described in [1] to replace the call to the 'date'
> command with a version that uses SOURCE_DATE_EPOCH if available. This
> is needed for reproducible builds.
>
> The -d "@..." syntax was introduced in GNU date about 2005 (but only
> added to the docuemntation in 2011), so I assume a version supporting
> this syntax is available, if SOURCE_DATE_EPOCH is defined. If
> SOURCE_DATE_EPOCH is not defined, nothing changes with respect to the
> current behavior.
>
> [1] https://reproducible-builds.org/docs/source-date-epoch/
>
> Signed-off-by: Maximilian Engelhardt <maxi@daemonizer.de>
> ---
>  docs/Makefile | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/docs/Makefile b/docs/Makefile
> index b30cc619f8..beba02a94f 100644
> --- a/docs/Makefile
> +++ b/docs/Makefile
> @@ -3,7 +3,13 @@ include $(XEN_ROOT)/Config.mk
>  -include $(XEN_ROOT)/config/Docs.mk
>  
>  VERSION		:= $(shell $(MAKE) -C $(XEN_ROOT)/xen --no-print-directory xenversion)
> -DATE		:= $(shell date +%Y-%m-%d)
> +
> +DATE_FMT	:= +%Y-%m-%d
> +ifdef SOURCE_DATE_EPOCH
> +DATE		:= $(shell date -u -d "@$(SOURCE_DATE_EPOCH)" "$(DATE_FMT)" 2>/dev/null || date -u -r "$(SOURCE_DATE_EPOCH)" "$(DATE_FMT)" 2>/dev/null || date -u "$(DATE_FMT)")
> +else
> +DATE		:= $(shell date "$(DATE_FMT)")
> +endif
>  
>  DOC_ARCHES      := arm x86_32 x86_64
>  MAN_SECTIONS    := 1 5 7 8

While this looks fine for docs, there's another (identical) use of date
in tools/firmware/hvmloader/Makefile, as well as some differing uses to
construct XEN_BUILD_{DATE,TIME}.  INSTALL talks about VGABIOS_REL_DATE too.

Does something like this work for you?  It seems to DTRT for SMBIOS.  It
needs adapting a bit more for vgabios and Xen, but I think having one
common $(date) is going to be better than ad-hoc ones over the tree.

~Andrew
Maximilian Engelhardt Dec. 30, 2024, 10:28 p.m. UTC | #2
On Montag, 30. Dezember 2024 22:38:24 CET Andrew Cooper wrote:
> On 30/12/2024 9:00 pm, Maximilian Engelhardt wrote:
> > Use the solution described in [1] to replace the call to the 'date'
> > command with a version that uses SOURCE_DATE_EPOCH if available. This
> > is needed for reproducible builds.
> > 
> > The -d "@..." syntax was introduced in GNU date about 2005 (but only
> > added to the docuemntation in 2011), so I assume a version supporting
> > this syntax is available, if SOURCE_DATE_EPOCH is defined. If
> > SOURCE_DATE_EPOCH is not defined, nothing changes with respect to the
> > current behavior.
> > 
> > [1] https://reproducible-builds.org/docs/source-date-epoch/
> > 
> > Signed-off-by: Maximilian Engelhardt <maxi@daemonizer.de>
> > ---
> > 
> >  docs/Makefile | 8 +++++++-
> >  1 file changed, 7 insertions(+), 1 deletion(-)
> > 
> > diff --git a/docs/Makefile b/docs/Makefile
> > index b30cc619f8..beba02a94f 100644
> > --- a/docs/Makefile
> > +++ b/docs/Makefile
> > @@ -3,7 +3,13 @@ include $(XEN_ROOT)/Config.mk
> > 
> >  -include $(XEN_ROOT)/config/Docs.mk
> >  
> >  VERSION		:= $(shell $(MAKE) -C $(XEN_ROOT)/xen --no-print-directory
> >  xenversion)> 
> > -DATE		:= $(shell date +%Y-%m-%d)
> > +
> > +DATE_FMT	:= +%Y-%m-%d
> > +ifdef SOURCE_DATE_EPOCH
> > +DATE		:= $(shell date -u -d "@$(SOURCE_DATE_EPOCH)" "$(DATE_FMT)"
> > 2>/dev/null || date -u -r "$(SOURCE_DATE_EPOCH)" "$(DATE_FMT)"
> > 2>/dev/null || date -u "$(DATE_FMT)") +else
> > +DATE		:= $(shell date "$(DATE_FMT)")
> > +endif
> > 
> >  DOC_ARCHES      := arm x86_32 x86_64
> >  MAN_SECTIONS    := 1 5 7 8
> 
> While this looks fine for docs, there's another (identical) use of date
> in tools/firmware/hvmloader/Makefile, as well as some differing uses to
> construct XEN_BUILD_{DATE,TIME}.  INSTALL talks about VGABIOS_REL_DATE too.
> 
> Does something like this work for you?  It seems to DTRT for SMBIOS.  It
> needs adapting a bit more for vgabios and Xen, but I think having one
> common $(date) is going to be better than ad-hoc ones over the tree.
> 
> ~Andrew

Hi Andrew,

Thanks for your quick reply. Your patch looks fine to me. You can add my 
Tested-by.

We currently use "export XEN_BUILD_{DATE,TIME}=...", "export 
SMBIOS_REL_DATE=..." and "export VGABIOS_REL_DATE=..." for building xen in 
Debian, so we did not run into reproducibility problems with these. But having 
them combined to all use SOURCE_DATE_EPOCH if available sounds like a good 
idea and would also benefit other downstream users.

Maxi
Maximilian Engelhardt Jan. 1, 2025, 7:03 p.m. UTC | #3
On Montag, 30. Dezember 2024 23:28:42 CET Maximilian Engelhardt wrote:
> On Montag, 30. Dezember 2024 22:38:24 CET Andrew Cooper wrote:
> > On 30/12/2024 9:00 pm, Maximilian Engelhardt wrote:
> > > Use the solution described in [1] to replace the call to the 'date'
> > > command with a version that uses SOURCE_DATE_EPOCH if available. This
> > > is needed for reproducible builds.
> > > 
> > > The -d "@..." syntax was introduced in GNU date about 2005 (but only
> > > added to the docuemntation in 2011), so I assume a version supporting
> > > this syntax is available, if SOURCE_DATE_EPOCH is defined. If
> > > SOURCE_DATE_EPOCH is not defined, nothing changes with respect to the
> > > current behavior.
> > > 
> > > [1] https://reproducible-builds.org/docs/source-date-epoch/
> > > 
> > > Signed-off-by: Maximilian Engelhardt <maxi@daemonizer.de>
> > > ---
> > > 
> > >  docs/Makefile | 8 +++++++-
> > >  1 file changed, 7 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/docs/Makefile b/docs/Makefile
> > > index b30cc619f8..beba02a94f 100644
> > > --- a/docs/Makefile
> > > +++ b/docs/Makefile
> > > @@ -3,7 +3,13 @@ include $(XEN_ROOT)/Config.mk
> > > 
> > >  -include $(XEN_ROOT)/config/Docs.mk
> > >  
> > >  VERSION		:= $(shell $(MAKE) -C $(XEN_ROOT)/xen --no-print-
directory
> > >  xenversion)>
> > > 
> > > -DATE		:= $(shell date +%Y-%m-%d)
> > > +
> > > +DATE_FMT	:= +%Y-%m-%d
> > > +ifdef SOURCE_DATE_EPOCH
> > > +DATE		:= $(shell date -u -d "@$(SOURCE_DATE_EPOCH)" "$(DATE_FMT)"
> > > 2>/dev/null || date -u -r "$(SOURCE_DATE_EPOCH)" "$(DATE_FMT)"
> > > 2>/dev/null || date -u "$(DATE_FMT)") +else
> > > +DATE		:= $(shell date "$(DATE_FMT)")
> > > +endif
> > > 
> > >  DOC_ARCHES      := arm x86_32 x86_64
> > >  MAN_SECTIONS    := 1 5 7 8
> > 
> > While this looks fine for docs, there's another (identical) use of date
> > in tools/firmware/hvmloader/Makefile, as well as some differing uses to
> > construct XEN_BUILD_{DATE,TIME}.  INSTALL talks about VGABIOS_REL_DATE
> > too.
> > 
> > Does something like this work for you?  It seems to DTRT for SMBIOS.  It
> > needs adapting a bit more for vgabios and Xen, but I think having one
> > common $(date) is going to be better than ad-hoc ones over the tree.
> > 
> > ~Andrew
> 
> Hi Andrew,
> 
> Thanks for your quick reply. Your patch looks fine to me. You can add my
> Tested-by.
> 
> We currently use "export XEN_BUILD_{DATE,TIME}=...", "export
> SMBIOS_REL_DATE=..." and "export VGABIOS_REL_DATE=..." for building xen in
> Debian, so we did not run into reproducibility problems with these. But
> having them combined to all use SOURCE_DATE_EPOCH if available sounds like
> a good idea and would also benefit other downstream users.
> 
> Maxi

Hi Andrew,

I extended your patch to also cover the other uses of date. Please check if 
this look reasonable as I'm not an expert in makefiles. It seems to DTRT in 
the cases I tested.

What I changed compared to your patch:

* Add LC_ALL=C to all date commands. This was also missing in my original 
patch, but I think it's a good thing to do and XEN_BUILD_{DATE,TIME} already 
do it.

* Change the quoting to allow calling the date command without any additional 
(formatting) arguments.

* Add an include of Config.mk to tools/firmware/vgabios/Makefile and moved the 
definition of XEN_BUILD_{DATE,TIME} further down in xen/Makefile to have the 
newly defined date wrapper available.

Does this look reasonable or are there parts that should be done differently?

Thanks,
Maxi
diff mbox series

Patch

diff --git a/docs/Makefile b/docs/Makefile
index b30cc619f8..beba02a94f 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -3,7 +3,13 @@  include $(XEN_ROOT)/Config.mk
 -include $(XEN_ROOT)/config/Docs.mk
 
 VERSION		:= $(shell $(MAKE) -C $(XEN_ROOT)/xen --no-print-directory xenversion)
-DATE		:= $(shell date +%Y-%m-%d)
+
+DATE_FMT	:= +%Y-%m-%d
+ifdef SOURCE_DATE_EPOCH
+DATE		:= $(shell date -u -d "@$(SOURCE_DATE_EPOCH)" "$(DATE_FMT)" 2>/dev/null || date -u -r "$(SOURCE_DATE_EPOCH)" "$(DATE_FMT)" 2>/dev/null || date -u "$(DATE_FMT)")
+else
+DATE		:= $(shell date "$(DATE_FMT)")
+endif
 
 DOC_ARCHES      := arm x86_32 x86_64
 MAN_SECTIONS    := 1 5 7 8