functions on platform were that's the best way to handle exporting
global variables in shared libraries. To enable this functionality,
one must configure with "EXPORT_VAR_AS_FN" or defined the C macro
"OPENSSL_EXPORT_VAR_AS_FUNCTION" in crypto/opensslconf.h (the latter
is normally done by Configure or something similar).
To implement a global variable, use the macro OPENSSL_IMPLEMENT_GLOBAL
in the source file (foo.c) like this:
OPENSSL_IMPLEMENT_GLOBAL(int,foo)=1;
OPENSSL_IMPLEMENT_GLOBAL(double,bar);
To declare a global variable, use the macros OPENSSL_DECLARE_GLOBAL
and OPENSSL_GLOBAL_REF in the header file (foo.h) like this:
OPENSSL_DECLARE_GLOBAL(int,foo);
#define foo OPENSSL_GLOBAL_REF(foo)
OPENSSL_DECLARE_GLOBAL(double,bar);
#define bar OPENSSL_GLOBAL_REF(bar)
The #defines are very important, and therefore so is including the
header file everywere where the defined globals are used.
The macro OPENSSL_EXPORT_VAR_AS_FUNCTION also affects the definition
of ASN.1 items, but that structure is a bt different.
The largest change is in util/mkdef.pl which has been enhanced with
better and easier to understand logic to choose which symbols should
go into the Windows .def files as well as a number of fixes and code
cleanup (among others, algorithm keywords are now sorted
lexicographically to avoid constant rewrites).