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authorPaul Spooren2021-05-13 23:39:05 +0200
committerDenys Vlasenko2021-06-05 18:13:00 +0200
commit947a22b33262c93e5c50286b723b9086a33a4c1f (patch)
treea386baf9c281da44d705a0f6ec5c2263051016bc /scripts
parent1b30c63dfdd4f31faa6deda69345bf07f23aa334 (diff)
downloadbusybox-947a22b33262c93e5c50286b723b9086a33a4c1f.zip
busybox-947a22b33262c93e5c50286b723b9086a33a4c1f.tar.gz
build system: use SOURCE_DATE_EPOCH for timestamp if available
The SOURCE_DATE_EPOCH is an effort of the Reproducible Builds organization to make timestamps/build dates in compiled tools deterministic over several repetitive builds. Busybox shows by default the build date timestamp which changes whenever compiled. To have a reasonable accurate build date while staying reproducible, it's possible to use the *date of last source modification* rather than the current time and date. Further information on SOURCE_DATE_EPOCH are available online [1]. This patch modifies `confdata.c` so that the content of the SOURCE_DATE_EPOCH env variable is used as timestamp. To be independent of different timezones between builds, whenever SOURCE_DATE_EPOCH is defined the GMT time is used. [1]: https://reproducible-builds.org/docs/source-date-epoch/ Signed-off-by: Paul Spooren <mail@aparcar.org> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'scripts')
-rw-r--r--scripts/kconfig/confdata.c17
1 files changed, 14 insertions, 3 deletions
diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index 9976011..249a319 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -342,6 +342,8 @@ int conf_write(const char *name)
time_t now;
int use_timestamp = 1;
char *env;
+ char *source_date_epoch;
+ struct tm *build_time;
dirname[0] = 0;
if (name && name[0]) {
@@ -378,7 +380,16 @@ int conf_write(const char *name)
}
sym = sym_lookup("KERNELVERSION", 0);
sym_calc_value(sym);
- time(&now);
+
+ source_date_epoch = getenv("SOURCE_DATE_EPOCH");
+ if (source_date_epoch && *source_date_epoch) {
+ now = strtoull(source_date_epoch, NULL, 10);
+ build_time = gmtime(&now);
+ } else {
+ time(&now);
+ build_time = localtime(&now);
+ }
+
env = getenv("KCONFIG_NOTIMESTAMP");
if (env && *env)
use_timestamp = 0;
@@ -398,14 +409,14 @@ int conf_write(const char *name)
if (use_timestamp) {
size_t ret = \
strftime(buf, sizeof(buf), "#define AUTOCONF_TIMESTAMP "
- "\"%Y-%m-%d %H:%M:%S %Z\"\n", localtime(&now));
+ "\"%Y-%m-%d %H:%M:%S %Z\"\n", build_time);
/* if user has Factory timezone or some other odd install, the
* %Z above will overflow the string leaving us with undefined
* results ... so let's try again without the timezone.
*/
if (ret == 0)
strftime(buf, sizeof(buf), "#define AUTOCONF_TIMESTAMP "
- "\"%Y-%m-%d %H:%M:%S\"\n", localtime(&now));
+ "\"%Y-%m-%d %H:%M:%S\"\n", build_time);
} else { /* bbox */
strcpy(buf, "#define AUTOCONF_TIMESTAMP \"\"\n");
}