We were using an anti-pattern of:
- LoadLibrary
- GetProcAddress
- FreeLibrary
This is problematic because of several reasons:
- We are holding on to pointers into a library we just unloaded.
- Calling LoadLibrary results in an increase in the reference count of
the library in question and any libraries that it depends on and
so-on and so-forth. This is none too quick.
Instead, use GetModuleHandleEx with GET_MODULE_HANDLE_EX_FLAG_PIN. This
is done because because we didn't bring the reference for the library
into existence and therefor shouldn't count on it being around later.
llvm-svn: 192550
This addresses several issues in a similar vein:
- Use the Unicode APIs when possible, running nm on clang shows that we
only use Unicode APIs except for FormatMessage, CreateSemaphore, and
GetModuleHandle. AFAICT, the latter two are coming from MinGW and
not LLVM itself.
- Make getMainExecutable more resilient. It previously considered
return values of zero from ::GetModuleFileNameA to be acceptable.
llvm-svn: 192096