1 files changed, 12 insertions, 19 deletions

diff --git a/src/l4d1democompat.c b/src/l4d1democompat.c
index 1cfe959..4280d53 100644
--- a/src/l4d1democompat.c
+++ b/src/l4d1democompat.c
@@ -17,15 +17,16 @@
  */
 
 #include "accessor.h"
+#include "chunklets/x86.h"
 #include "con_.h"
 #include "errmsg.h"
 #include "feature.h"
+#include "gametype.h"
 #include "hook.h"
 #include "intdefs.h"
 #include "mem.h"
 #include "sst.h"
 #include "vcall.h"
-#include "x86.h"
 #include "x86util.h"
 
 FEATURE("Left 4 Dead 1 demo file backwards compatibility")
@@ -50,9 +51,8 @@ static GetHostVersion_func orig_GetHostVersion;
 typedef void (*VCALLCONV ReadDemoHeader_func)(void *);
 static ReadDemoHeader_func orig_ReadDemoHeader;
 
-static inline bool find_ReadDemoHeader(con_cmdcb listdemo_cb) {
+static inline bool find_ReadDemoHeader(const uchar *insns) {
 	// Find the call to ReadDemoHeader in the listdemo callback
-	const uchar *insns = (const uchar *)listdemo_cb;
 	for (const uchar *p = insns; p - insns < 192;) {
 		if (p[0] == X86_LEA && p[1] == X86_MODRM(2, 1, 4) && p[2] == 0x24 &&
 				p[7] == X86_CALL && p[12] == X86_LEA &&
@@ -115,21 +115,14 @@ static void VCALLCONV hook_ReadDemoHeader(struct CDemoFile *this) {
 	orig_ReadDemoHeader(this);
 }
 
-#if defined(__clang__)
-__attribute__((naked))
-#elif defined(_MSC_VER)
-#error Inadequate inline assembly syntax, use Clang instead.
-#else
-#error No way to do naked functions! We only support Clang at the moment.
-#endif
-static int hook_midpoint() {
-	__asm__ volatile (
-		"pushl %%eax\n"
-		"movl %1, %%eax\n"
-		"movl (%%eax), %%eax\n" // dereference this_protocol
-		"movl %%eax, %0\n" // store in demoversion
-		"popl %%eax\n"
-		"jmpl *%2\n"
+static asm_only int hook_midpoint() {
+	__asm volatile (
+		"push eax\n"
+		"mov eax, %1\n"
+		"mov eax, [eax]\n" // dereference this_protocol
+		"mov %0, eax\n" // store in demoversion
+		"pop eax\n"
+		"jmp dword ptr %2\n"
 		: "=m" (demoversion)
 		: "m" (this_protocol), "m" (ReadDemoHeader_midpoint)
 	);
@@ -138,7 +131,7 @@ static int hook_midpoint() {
 INIT {
 	struct con_cmd *cmd_listdemo = con_findcmd("listdemo");
 	if_cold (!cmd_listdemo) return FEAT_INCOMPAT; // should never happen!
-	if_cold (!find_ReadDemoHeader(cmd_listdemo->cb)) {
+	if_cold (!find_ReadDemoHeader(cmd_listdemo->cb_insns)) {
 		errmsg_errorx("couldn't find ReadDemoHeader function");
 		return FEAT_INCOMPAT;
 	}