[PATCH v5] Makefile: Add build time and compiler info string

[Peter Korsgaard]

>>>>> "Bin" == Bin Meng <bmeng.cn at gmail.com> writes:

Hi,

 >> Users will have to figure-out/remember a fixed build date when
 >> using SOURCE_DATA_EPOCH for reproducible builds whereas
 >> users don't need to do anything when BUILD_INFO is not defined.

 > This is not 100% true as with current OpenSBI we never claim its build
 > is fully reproducible. For example, one can easily add __DATE__ to the
 > source codes which will alter unless we provide SOURCE_DATA_EPOCH.

Notice that GCC >= 7 does in fact look for SOURCE_DATE_EPOCH in the
environment and change the behaviour of the __DATE__ / __TIME__ macros:

https://gcc.gnu.org/onlinedocs/cpp/Environment-Variables.html

-- 
Bye, Peter Korsgaard