[U-Boot] [RFC PATCH v2] Makefile: search for GNU date

Andreas Bießmann
2015-08-27T13:52:13Z

On 08/27/2015 03:03 PM, Paul Kocialkowski wrote:
> Le jeudi 27 ao?t 2015 ? 11:30 +0200, Andreas Bie?mann a ?crit :

>> Changes in v2:
>> * check for '-u' and '-d "@0"' switch rather than for the GNU variant
>>
>> Makefile | 15 ++++++++++++---
>> 1 file changed, 12 insertions(+), 3 deletions(-)
>>
>> diff --git a/Makefile b/Makefile
>> index b9b2375..b797e38 100644
>> --- a/Makefile
>> +++ b/Makefile
>> @@ -346,6 +346,10 @@ PERL = perl
>> PYTHON = python
>> DTC = dtc
>> CHECK = sparse
>> +DATE := $(foreach date,gdate date.gnu date, \
>> + $(shell _date=`which $(date)`; \
>> + $${_date} -u -d "@0" >/dev/null 2>&1; \
>> + test $$? -eq 0 && echo $${_date}))
>
> First, I don't understand why you need to call date with the full path:
> if which can find it, then calling the binary without its full path
> should do just as well, right?

You'r right.

> Then, correct me if I'm wrong, but calling test and using && is
> overkill, you could simply do: $${_date} -u -d "@0" >/dev/null 2>&1 &&
> echo $${_date}

Also true.

> So in the end, the whole line would look like:
>
> DATE := $(foreach date,gdate date.gnu date, \
> $($${date} -u -d "@0" >/dev/null 2>&1 \
> && echo $${date}))
>
> Let me know what you think (and please test it as well).

That should work. I wonder however why we don't include this snippet in
the filechk_timestamp.h script directly. In fact the $(DATE) (a date
that support -d '@0' switch) is just used there, so why clobber the
Makefile with it?

---8<---
define filechk_timestamp.h
(if test -n "$${SOURCE_DATE_EPOCH}"; then \
date=""; \
for _date in gdate date.gnu date; do \
$${_date} -u -d "$${SOURCE_DATE}" >/dev/null 2>&1 && \
date="$${_date}"; \
done; \
if test -n "$${date}"; then \
SOURCE_DATE="@$${SOURCE_DATE_EPOCH}"; \
LC_ALL=C $${date} -u -d "$${SOURCE_DATE}" +'#define U_BOOT_DATE "%b
%d %C%y"'; \
LC_ALL=C $${date} -u -d "$${SOURCE_DATE}" +'#define U_BOOT_TIME "%T"'; \
LC_ALL=C $${date} -u -d "$${SOURCE_DATE}" +'#define U_BOOT_TZ "%z"'; \
else \
return 42; \
fi; \
else \
LC_ALL=C date +'#define U_BOOT_DATE "%b %d %C%y"'; \
LC_ALL=C date +'#define U_BOOT_TIME "%T"'; \
LC_ALL=C date +'#define U_BOOT_TZ "%z"'; \
fi)
endef
--->8---

>> CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
>> -Wbitwise -Wno-return-void -D__CHECK_ENDIAN__ $(CF)
>> @@ -1281,9 +1285,9 @@ endef
>> define filechk_timestamp.h
>> (if test -n "$${SOURCE_DATE_EPOCH}"; then \
>> SOURCE_DATE="@$${SOURCE_DATE_EPOCH}"; \
>> - LC_ALL=C date -u -d "$${SOURCE_DATE}" +'#define U_BOOT_DATE "%b %d %C%y"'; \
>> - LC_ALL=C date -u -d "$${SOURCE_DATE}" +'#define U_BOOT_TIME "%T"'; \
>> - LC_ALL=C date -u -d "$${SOURCE_DATE}" +'#define U_BOOT_TZ "%z"'; \
>> + LC_ALL=C $(DATE) -u -d "$${SOURCE_DATE}" +'#define U_BOOT_DATE "%b %d %C%y"'; \
>> + LC_ALL=C $(DATE) -u -d "$${SOURCE_DATE}" +'#define U_BOOT_TIME "%T"'; \
>> + LC_ALL=C $(DATE) -u -d "$${SOURCE_DATE}" +'#define U_BOOT_TZ "%z"'; \
>> else \
>> LC_ALL=C date +'#define U_BOOT_DATE "%b %d %C%y"'; \
>> LC_ALL=C date +'#define U_BOOT_TIME "%T"'; \
>> @@ -1295,6 +1299,11 @@ $(version_h): include/config/uboot.release FORCE
>> $(call filechk,version.h)
>>
>> $(timestamp_h): $(srctree)/Makefile FORCE
>> +ifneq ($(strip $(SOURCE_DATE_EPOCH)),)
>> +ifeq ($(strip $(DATE)),)
>> + $(error "Your gdate/date.gnu/date does not support the '-u' and '-d' switches like GNU date does!")
>> +endif
>> +endif
>> $(call filechk,timestamp.h)
>>
>> # ---------------------------------------------------------------------------
>