Move to static trampolines and type-safe hooks

For some reason the DLL got a tiny little bit bigger again but that's
fine. This will make orig_ calls more efficient in the inline case, and
also make it harder to screw up and hook the wrong thing by mistake.

Self-explanatory-ish, apart from the fact it's a fairly large API change
of course. And it relies on some more bonkers assembler directive
hackery.

But it works!

The only complaint one might have is that the featsetup functions no
longer take an explicit string which occasionally yields slightly less
perfect error messages, but I've decided this isn't really a problem and
makes the API nicer to use. It's a tradeoff, innit.

1 files changed, 21 insertions, 25 deletions

diff --git a/src/rinput.c b/src/rinput.c
index a7ed1a4..8d3a6d9 100644
--- a/src/rinput.c
+++ b/src/rinput.c
@@ -91,27 +91,24 @@ static ssize __stdcall inproc(void *wnd, uint msg, usize wp, ssize lp) {
 
 typedef int (*__stdcall GetCursorPos_func)(POINT *p);
 typedef uint (*VCALLCONV GetRawMouseAccumulators_func)(void *, int *, int *);
-static union { // more cheeky space saving
-	GetCursorPos_func orig_GetCursorPos;
-	GetRawMouseAccumulators_func orig_GetRawMouseAccumulators;
-} u2;
-#define orig_GetCursorPos u2.orig_GetCursorPos
-#define orig_GetRawMouseAccumulators u2.orig_GetRawMouseAccumulators
-
-static int __stdcall hook_GetCursorPos(POINT *p) {
+DEF_INLINE_HOOK(GetCursorPos_func, GetCursorPos)
+DEF_VTABLE_HOOK(GetRawMouseAccumulators_func, GetRawMouseAccumulators)
+
+static int __stdcall hookdest_GetCursorPos(POINT *p) {
 	if (!con_getvari(m_rawinput)) return orig_GetCursorPos(p);
 	p->x = cx; p->y = cy;
 	return 1;
 }
 
 typedef int (*__stdcall SetCursorPos_func)(int x, int y);
-static SetCursorPos_func orig_SetCursorPos = 0;
-static int __stdcall hook_SetCursorPos(int x, int y) {
+DEF_INLINE_HOOK(SetCursorPos_func, SetCursorPos)
+static int __stdcall hookdest_SetCursorPos(int x, int y) {
 	cx = x; cy = y;
 	return orig_SetCursorPos(x, y);
 }
 
-static uint VCALLCONV hook_GetRawMouseAccumulators(void *this, int *x, int *y) {
+static uint VCALLCONV hookdest_GetRawMouseAccumulators(void *this,
+		int *x, int *y) {
 	int dx, dy;
 	uint ret = orig_GetRawMouseAccumulators(this, &dx, &dy);
 	int d = con_getvari(sst_mouse_factor);
@@ -135,9 +132,8 @@ INIT {
 			errmsg_errorx("couldn't make virtual table writable");
 			return FEAT_FAIL;
 		}
-		orig_GetRawMouseAccumulators = (GetRawMouseAccumulators_func)hook_vtable(
-				vtable_insys, vtidx_GetRawMouseAccumulators,
-				(void *)&hook_GetRawMouseAccumulators);
+		hook_GetRawMouseAccumulators(vtable_insys, vtidx_GetRawMouseAccumulators,
+				&hookdest_GetRawMouseAccumulators);
 	}
 	else {
 		// create cvar hidden so config is still preserved if we fail to init
@@ -181,11 +177,11 @@ INIT {
 	}
 
 	int err;
-	struct hook_inline_featsetup_ret h1 = hook_inline_featsetup(
-			(void *)GetCursorPos, (void **)&orig_GetCursorPos, "GetCursorPos");
+	struct hook_featsetup_ret_GetCursorPos h1 =
+			hook_featsetup_GetCursorPos(&GetCursorPos);
 	if_cold (err = h1.err) goto e0;
-	struct hook_inline_featsetup_ret h2 = hook_inline_featsetup(
-			(void *)SetCursorPos, (void **)&orig_SetCursorPos, "SetCursorPos");
+	struct hook_featsetup_ret_SetCursorPos h2 =
+			hook_featsetup_SetCursorPos(&SetCursorPos);
 	if_cold (err = h2.err) goto e0;
 	inwin = CreateWindowExW(0, L"RInput", L"RInput", 0, 0, 0, 0, 0, 0, 0, 0, 0);
 	if_cold (!inwin) {
@@ -202,8 +198,8 @@ INIT {
 		err = FEAT_FAIL;
 		goto e1;
 	}
-	hook_inline_commit(h1.prologue, (void *)&hook_GetCursorPos);
-	hook_inline_commit(h2.prologue, (void *)&hook_SetCursorPos);
+	hook_commit_GetCursorPos(h1.hookpos, &hookdest_GetCursorPos);
+	hook_commit_SetCursorPos(h2.hookpos, &hookdest_SetCursorPos);
 
 ok:	// XXX: this is a little tricky and a little clunky. we have registered
 	// m_rawinput above but sst_mouse_factor will get auto-registered after init
@@ -218,7 +214,7 @@ e0:	UnregisterClassW(L"RInput", 0);
 }
 
 END {
-	if_hot (orig_SetCursorPos) { // we inited our own implementation
+	if_hot (inwin) { // we inited our own implementation
 		RAWINPUTDEVICE rd = {
 			.dwFlags = RIDEV_REMOVE,
 			.hwndTarget = 0,
@@ -229,13 +225,13 @@ END {
 		DestroyWindow(inwin);
 		if_hot (!sst_userunloaded) return;
 		UnregisterClassW(L"RInput", 0);
-		unhook_inline((void *)orig_GetCursorPos);
-		unhook_inline((void *)orig_SetCursorPos);
+		unhook_SetCursorPos();
+		unhook_GetCursorPos();
 	}
 	else if_cold (sst_userunloaded) {
 		// we must have hooked the *existing* implementation
-		unhook_vtable(vtable_insys, vtidx_GetRawMouseAccumulators,
-				(void *)orig_GetRawMouseAccumulators);
+		unhook_GetRawMouseAccumulators(vtable_insys,
+				vtidx_GetRawMouseAccumulators);
 	}
 }