From 18aca45673f2311215b24db42f65fa23cc2dcbc4 Mon Sep 17 00:00:00 2001
From: "BADIM-PC\\Vadim" <grigoruk@gmail.com>
Date: Tue, 12 Dec 2017 12:50:39 +0300
Subject: [PATCH] Impossible to exit infinite while loop #197

---
 src/luaapi.c | 21 ++++++++++++++++++++-
 src/run.c    | 12 ++++++++++++
 src/ticapi.h |  3 +++
 3 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/src/luaapi.c b/src/luaapi.c
index bf40d61..7f01694 100644
--- a/src/luaapi.c
+++ b/src/luaapi.c
@@ -29,6 +29,8 @@
 #include "machine.h"
 #include "ext/moonscript.h"
 
+#define LUA_LOC_STACK 1E8 // 100.000.000
+
 static const char TicMachine[] = "_TIC80";
 
 s32 luaopen_lpeg(lua_State *L);
@@ -1061,6 +1063,21 @@ static const lua_CFunction ApiFunc[] =
 
 STATIC_ASSERT(api_func, COUNT_OF(ApiKeywords) == COUNT_OF(ApiFunc));
 
+static void checkForceExit(lua_State *lua, lua_Debug *luadebug)
+{
+	tic_machine* machine = getLuaMachine(lua);
+
+	tic_tick_data* tick = machine->data;
+
+	if(tick->hook)
+	{
+		tick->hook(tick->data);
+
+		if(tick->forceExit)
+			luaL_error(lua, "script execution was interrupted");
+	}
+}
+
 static void initAPI(tic_machine* machine)
 {
 	lua_pushlightuserdata(machine->lua, machine);
@@ -1072,6 +1089,8 @@ static void initAPI(tic_machine* machine)
 
 	registerLuaFunction(machine, lua_dofile, "dofile");
 	registerLuaFunction(machine, lua_loadfile, "loadfile");
+
+	lua_sethook(machine->lua, &checkForceExit, LUA_MASKCOUNT, LUA_LOC_STACK);
 }
 
 void closeLua(tic_machine* machine)
@@ -1216,7 +1235,7 @@ void callLuaTick(tic_machine* machine)
 		lua_getglobal(lua, TicFunc);
 		if(lua_isfunction(lua, -1)) 
 		{
-			if(lua_pcall(lua, 0, 0, 0) != LUA_OK)
+			if(lua_pcall(lua, 0, 0, 0) != LUA_OK)	
 				machine->data->error(machine->data->data, lua_tostring(lua, -1));
 		}
 		else 
diff --git a/src/run.c b/src/run.c
index 2565d75..ca847a4 100644
--- a/src/run.c
+++ b/src/run.c
@@ -178,6 +178,16 @@ static void preseed()
 #endif
 }
 
+static void poll(void* data)
+{
+	Run* run = (Run*)data;
+
+	while(pollEvent());
+
+	if (getStudioMode() != TIC_RUN_MODE)
+		run->tickData.forceExit = true;
+}
+
 void initRun(Run* run, Console* console, tic_mem* tic)
 {
 	*run = (Run)
@@ -197,6 +207,8 @@ void initRun(Run* run, Console* console, tic_mem* tic)
 			.data = run,
 			.exit = onExit,
 			.preprocessor = processDoFile,
+			.hook = poll,
+			.forceExit = false,
 		},
 	};
 
diff --git a/src/ticapi.h b/src/ticapi.h
index 3c61988..bb35833 100644
--- a/src/ticapi.h
+++ b/src/ticapi.h
@@ -45,16 +45,19 @@ typedef struct
 typedef void(*TraceOutput)(void*, const char*, u8 color);
 typedef void(*ErrorOutput)(void*, const char*);
 typedef void(*ExitCallback)(void*);
+typedef void(*HookCallback)(void*);
 
 typedef struct
 {
 	TraceOutput trace;
 	ErrorOutput error;
 	ExitCallback exit;
+	HookCallback hook;
 	
 	u64 (*counter)();
 	u64 (*freq)();
 	u64 start;
+	bool forceExit;
 
 	void (*preprocessor)(void* data, char* dst);