This commit changes the following code paths to do direct system calls
to some WIN32 functions rather than loading them from an external
library, shaving some code in the process:
- Creation of restricted tokens in pg_ctl.c, introduced by a25cd81.
- QuerySecurityContextToken() in auth.c for SSPI authentication in the
backend, introduced in d602592.
- CreateRestrictedToken() in src/common/. This change is similar to the
case of pg_ctl.c.
Most of these functions were loaded rather than directly called because,
as mentioned in the code comments, MinGW headers were not declaring
them. I have double-checked the recent MinGW code, and all the
functions changed here are declared in its headers, so this change
should be safe. Note that I do not have a MinGW environment at hand so
I have not tested it directly, but that MSVC was fine with the change.
The buildfarm will tell soon enough if this change is appropriate or not
for a much broader set of environments.
A few code paths still use GetProcAddress() to load some functions:
- LDAP authentication for ldap_start_tls_sA(), where I am not confident
that this change would work.
- win32env.c and win32ntdll.c where we have a per-MSVC version
dependency for the name of the library loaded.
- crashdump.c for MiniDumpWriteDump() and EnumDirTree(), where direct
calls were not able to work after testing.
Reported-by: Thomas Munro
Reviewed-by: Justin Prysby
Discussion: https://postgr.es/m/CA+hUKG+BMdcaCe=P-EjMoLTCr3zrrzqbcVE=8h5LyNsSVHKXZA@mail.gmail.com