Use repeatable timestamps
This moves all of the date references under build/ to using a single
datetime that can be set manually using BUILD_DATETIME.
It also adds an option, OVERRIDE_C_DATE_TIME, that if set to true, will
redefine __DATE__ and __TIME__ for all C/C++ files so that it matches
BUILD_DATETIME.
Bug: 23117013
Change-Id: I7c17a32b794a5adf40b9cd69136fb0ff9f6084ec
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index f3b2297..170e20b 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -24,6 +24,7 @@
# DEFAULT_APP_TARGET_SDK
# BUILD_ID
# BUILD_NUMBER
+# BUILD_DATETIME
#
# Look for an optional file containing overrides of the defaults,
@@ -89,6 +90,18 @@
BUILD_ID := UNKNOWN
endif
+ifeq "" "$(BUILD_DATETIME)"
+ # Used to reproduce builds by setting the same time. Must be the number
+ # of seconds since the Epoch.
+ BUILD_DATETIME := $(shell date +%s)
+endif
+
+ifneq (,$(findstring Darwin,$(shell uname -sm)))
+DATE := date -r $(BUILD_DATETIME)
+else
+DATE := date -d @$(BUILD_DATETIME)
+endif
+
ifeq "" "$(BUILD_NUMBER)"
# BUILD_NUMBER should be set to the source control value that
# represents the current state of the source code. E.g., a
@@ -99,5 +112,5 @@
# If no BUILD_NUMBER is set, create a useful "I am an engineering build
# from this date/time" value. Make it start with a non-digit so that
# anyone trying to parse it as an integer will probably get "0".
- BUILD_NUMBER := eng.$(USER).$(shell date +%Y%m%d.%H%M%S)
+ BUILD_NUMBER := eng.$(USER).$(shell $(DATE) +%Y%m%d.%H%M%S)
endif