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

Andreas Bießmann
2015-08-27T08:13:49Z

The SOURCE_DATE_EPOCH mechanism for reproducible builds requires the GNU
variant of date. Respect this and search it, error on missing GNU date.

Signed-off-by: Andreas Bie?mann <andreas.devel@googlemail.com>
---
This commit tries to figure out if we have a GNU date variant
available. It errors on missing GNU date when it is required (for
SOURCE_DATE_EPOCH set). The result is:

---8<---
abiessmann at punisher % PATH=$ARMv5_PATH:$PATH CROSS_COMPILE=arm-v5te-linux-gnueabi- make SOURCE_DATE_EPOCH="`date -R`" O=/tmp/picosam ARCH=arm include/generated/timestamp_autogenerated.h
make[1]: Entering directory '/tmp/picosam'
/home/abiessmann/src/u-boot/Makefile:1303: *** "No GNU date found". Stop.
make[1]: Leaving directory '/tmp/picosam'
Makefile:146: recipe for target 'sub-make' failed
make: *** [sub-make] Error 2
abiessmann@punisher % PATH=$ARMv5_PATH:$PATH CROSS_COMPILE=arm-v5te-linux-gnueabi- make O=/tmp/picosam ARCH=arm include/generated/timestamp_autogenerated.h
make[1]: Entering directory '/tmp/picosam'
CHK include/generated/timestamp_autogenerated.h
UPD include/generated/timestamp_autogenerated.h
make[1]: Leaving directory '/tmp/picosam'
--->8---

It applies on top of http://patchwork.ozlabs.org/patch/506856/ (Makefile: Use correct timezone for U_BOOT_TZ).

Makefile | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/Makefile b/Makefile
index b9b2375..95eae64 100644
--- a/Makefile
+++ b/Makefile
@@ -346,6 +346,9 @@ PERL = perl
PYTHON = python
DTC = dtc
CHECK = sparse
+GNUDATE := $(foreach date,gdate date.gnu date, \
+ $(shell _date=`which $(date)`; \
+ $${_date} --version 2> /dev/null | $(AWK) "/GNU coreutils/ { print \"$${_date}\"; }"))

CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
-Wbitwise -Wno-return-void -D__CHECK_ENDIAN__ $(CF)
@@ -1281,9 +1284,9 @@ 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 "$${SOURCE_DATE}" +'#define U_BOOT_TZ "%z"'; \
+ LC_ALL=C $(GNUDATE) -u -d "$${SOURCE_DATE}" +'#define U_BOOT_DATE "%b %d %C%y"'; \
+ LC_ALL=C $(GNUDATE) -u -d "$${SOURCE_DATE}" +'#define U_BOOT_TIME "%T"'; \
+ LC_ALL=C $(GNUDATE) -u -d "$${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 +1298,11 @@ $(version_h): include/config/uboot.release FORCE
$(call filechk,version.h)

$(timestamp_h): $(srctree)/Makefile FORCE
+ifneq ($(strip $(SOURCE_DATE_EPOCH)),)
+ifeq ($(strip $(GNUDATE)),)
+ $(error "No GNU date found")
+endif
+endif
$(call filechk,timestamp.h)

# ---------------------------------------------------------------------------
--
2.1.4