Rework OS abstractions

- As much as possible avoid dragging system headers into translation
  units. This should avoid namespace pollution and, hopefully, speed up
  builds a little bit.

- Avoid leaning on the UCRT so much on Windows - prefer native win32
  calls and native file handles except where doing so is inconvenient
  (in particular, for stat(), which we might try and replace later).

- Also, switch from SystemFunction036 to ProcessPrng on Windows. This
  requires us to generate a stub for bcryptprimitives.dll because
  Microsoft haven't bothered to provide a link library, but the function
  is better-documented and seems to be a more direct under-the-hood call
  as well. Apparently it's what's used by the major web browsers these
  days, which seems like a good indication it's stable and trusted.

- Lastly, remove a bunch of functions and macros and stuff that weren't
  actually being used. It seems good to try and keep the scope of
  OS-dependent stuff relatively contained and only add to it when
  actually required.

1 files changed, 7 insertions, 0 deletions

diff --git a/src/hook.c b/src/hook.c
index 9a6e885..fe311cc 100644
--- a/src/hook.c
+++ b/src/hook.c
@@ -23,6 +23,13 @@
 #include "os.h"
 #include "x86.h"
 
+#ifdef _WIN32
+// try to avoid pulling in all of Windows.h for this... (redundant dllimport
+// avoids warnings in hook.test.c where Windows.h is included via test.h)
+__declspec(dllimport) int __stdcall FlushInstructionCache(
+		void *, const void *, usize);
+#endif
+
 // Warning: half-arsed hacky implementation (because that's all we really need)
 // Almost certainly breaks in some weird cases. Oh well! Most of the time,
 // vtable hooking is more reliable, this is only for, uh, emergencies.