Joseph pointed me at cb_get_source_date_epoch, which allows repeatable
builds and solves a FIXME I had on the modules branch. Unfortunately
it's used exclusively to generate __DATE__ and __TIME__ values, which
fallback to using a time(2) call. It'd be nicer if the preprocessor
made whatever time value it determined available to the rest of the
compiler. So this patch adds a new cpp_get_date function, which
abstracts the call to the get_source_date_epoch hook, or uses time
directly. The value is cached. Thus the timestamp I end up putting
on CMI files matches __DATE__ and __TIME__ expansions. That seems
worthwhile.
libcpp/
* include/cpplib.h (enum class CPP_time_kind): New.
(cpp_get_date): Declare.
* internal.h (struct cpp_reader): Replace source_date_epoch with
time_stamp and time_stamp_kind.
* init.c (cpp_create_reader): Initialize them.
* macro.c (_cpp_builtin_macro_text): Use cpp_get_date.
(cpp_get_date): Broken out from _cpp_builtin_macro_text and
genericized.
4b5f564a5d