Lunatic: fix stack discipline.

Preventing a continuously growing stack top and inevitable program termination.
Also, commonize the error handling to live on the engine side.

git-svn-id: https://svn.eduke32.com/eduke32@3352 1a8010ca-5511-0410-912e-c29ae57300e0

polymer/eduke32/build/include/lunatic.h

@@ -16,12 +16,14 @@ typedef struct
 // -- functions --
 
 // helpers taking the lua_State directly:
-void L_SetupDebugTraceback(lua_State *L);
 void L_PushDebugTraceback(lua_State *L);
 void L_CheckAndRegisterFunction(lua_State *L, void *regkeyaddr);
+int L_HandleError(lua_State *L, int errcode, void (*ErrorPrintFunc)(const char *));
 
 // Callback on Lua error. <str> must be used immediately or strdup'd.
 void (*L_ErrorFunc)(const char *str);
+// Out-of-memory handler, supposed to terminate the host program.
+void (*L_OutOfMemFunc)(void);
 
 int L_CreateState(L_State *estate, const char *name, void (*StateSetupFunc)(lua_State *));
 void L_DestroyState(L_State *estate);

polymer/eduke32/build/src/lunatic.c

@@ -25,7 +25,7 @@ void L_CheckAndRegisterFunction(lua_State *L, void *regkeyaddr)
     lua_settable(L, LUA_REGISTRYINDEX);  // "registry[regkeyaddr] = <lua function>", pop 2
 }
 
-void L_SetupDebugTraceback(lua_State *L)
+static void L_SetupDebugTraceback(lua_State *L)
 {
     // get debug.traceback
     lua_getglobal(L, "debug");
@@ -103,7 +103,17 @@ int L_CreateState(L_State *estate, const char *name, void (*StateSetupFunc)(lua_
         return -2;
     }
 
-    StateSetupFunc(L);
+    luaL_openlibs(L);
+    L_SetupDebugTraceback(L);
+    if (StateSetupFunc)
+        StateSetupFunc(L);
+
+    if (lua_gettop(L)==0)
+        L_PushDebugTraceback(L);
+    // Otherwise, it is assumed that StateSetupFunc pushed a custom traceback
+    // function onto the stack.
+
+    Bassert(lua_gettop(L)==1);
 
     return 0;
 }
@@ -120,7 +130,55 @@ void L_DestroyState(L_State *estate)
     estate->L = NULL;
 }
 
+static void L_OnOutOfMem(void)
+{
+    extern void uninitengine(void);
+    OSD_Printf("Out of memory in Lunatic.\n");
+    uninitengine();
+    exit(127);
+}
+
 void (*L_ErrorFunc)(const char *) = NULL;
+void (*L_OutOfMemFunc)(void) = L_OnOutOfMem;
+
+int L_HandleError(lua_State *L, int errcode, void (*ErrorPrintFunc)(const char *))
+{
+    if (errcode == LUA_ERRMEM)
+        L_OutOfMemFunc();
+
+    if (errcode == LUA_ERRRUN || errcode == LUA_ERRERR)
+    {
+        if (lua_isboolean(L, -1))
+        {
+            int32_t killit = lua_toboolean(L, -1);
+            lua_pop(L, 1);
+            return killit;
+        }
+        else
+        {
+            const char *errstr = (lua_type(L, -1)==LUA_TSTRING) ?
+                lua_tostring(L, -1) : "??? (error message not a string)";
+
+            ErrorPrintFunc(errstr);
+            if (L_ErrorFunc)
+                L_ErrorFunc(errstr);
+            lua_pop(L, 1);
+            return -1;
+        }
+    }
+
+    /* unreachable */
+#ifdef NDEBUG
+    return 0;
+#else
+    Bassert(0);
+#endif
+}
+
+static void L_ErrorPrint(const char *errmsg)
+{
+    OSD_Printf(OSD_ERROR "runtime error: %s\n", errmsg);
+}
 
 int L_RunString(L_State *estate, char *buf, int dofreebuf)
 {
@@ -128,9 +186,7 @@ int L_RunString(L_State *estate, char *buf, int dofreebuf)
     lua_State *L = estate->L;
 
     // -- lua --
-    Bassert(lua_gettop(L)==0);
+    Bassert(lua_gettop(L)==1);  // on top: a traceback function
-
-    L_PushDebugTraceback(L);
 
     i = luaL_loadstring(L, buf);
     Bassert(lua_gettop(L)==2);
@@ -138,47 +194,26 @@ int L_RunString(L_State *estate, char *buf, int dofreebuf)
         Bfree(buf);
 
     if (i == LUA_ERRMEM)
-    {
+        L_OutOfMemFunc();
-        lua_pop(L, 2);
-        return -1;
-    }
 
     if (i == LUA_ERRSYNTAX)
     {
         OSD_Printf(OSD_ERROR "state \"%s\" syntax error: %s\n", estate->name,
                    lua_tostring(L, -1));  // get err msg
-        lua_pop(L, 2);  // pop errmsg and debug.traceback
+        lua_pop(L, 1);  // pop errmsg
         return 3;
     }
 
-    // -- call the lua chunk! --
+    // call the lua chunk!
+    i = lua_pcall(L, 0, 0, 1);
+    Bassert(lua_gettop(L) == 1 + (i!=0));
 
-    i = lua_pcall(L, 0, 0, -2);
+    if (i != 0)
-    Bassert(lua_gettop(L) == 1+!!i);
+        L_HandleError(L, i, &L_ErrorPrint);
-    Bassert(i != LUA_ERRERR);  // we expect debug.traceback not to fail
 
-    if (i == LUA_ERRMEM)  // XXX: should be more sophisticated.  Clean up stack? Do GC?
+    Bassert(lua_gettop(L)==1);
-    {
-        lua_pop(L, 2);
-        return -1;
-    }
 
-    if (i == LUA_ERRRUN)
+    return i ? 4 : 0;
-    {
-        // get error message if possible
-        const char *errstr = (lua_type(L, -1)==LUA_TSTRING) ?
-            lua_tostring(L, -1) : "??? (errmsg not a string)";
-
-        OSD_Printf(OSD_ERROR "state \"%s\" runtime error: %s\n", estate->name, errstr);
-        if (L_ErrorFunc)
-            L_ErrorFunc(errstr);
-        lua_pop(L, 2);  // pop errmsg and debug.traceback
-        return 4;
-    }
-
-    lua_pop(L, 1);
-
-    return 0;
 }
 
 // -1: alloc failure

polymer/eduke32/source/lunatic/lunatic_game.c

@@ -31,8 +31,8 @@ double g_eventTotalMs[MAXEVENTS], g_actorTotalMs[MAXTILES];
 
 
 // forward-decls...
-static int32_t SetEvent_luacf(lua_State *L);
+static int32_t SetEvent_CF(lua_State *L);
-static int32_t SetActor_luacf(lua_State *L);
+static int32_t SetActor_CF(lua_State *L);
 
 // in lpeg.o
 extern int luaopen_lpeg(lua_State *L);
@@ -171,6 +171,12 @@ static void El_OnError(const char *str)
     }
 }
 
+static void El_OnOutOfMem(void)
+{
+    extern void G_GameExit(const char *msg);
+    G_GameExit("Out of memory in Lunatic.");
+}
+
 void El_ClearErrors(void)
 {
     int32_t i;
@@ -194,27 +200,48 @@ void El_DisplayErrors(void)
 
 ////////// STATE CREATION/DESTRUCTIION //////////
 
+static int our_traceback_CF(lua_State *L)
+{
+    Bassert(lua_gettop(L)==1);
+
+    if (lua_type(L, 1)==LUA_TBOOLEAN)
+    {
+        lua_pushvalue(L, 1);  // duplicate it
+        return 1;  // and tell Lua to return it
+    }
+
+    Bassert(lua_type(L, 1)==LUA_TSTRING);
+
+    // call debug.traceback with the string
+    L_PushDebugTraceback(L);
+    lua_pushvalue(L, 1);
+    lua_call(L, 1, 1);
+    Bassert(lua_gettop(L)==2);  // Lua will pop off args
+
+    return 1;
+}
+
 static void El_StateSetup(lua_State *L)
 {
-    luaL_openlibs(L);  // NOTE: we set up the sandbox in defs.ilua
     luaopen_lpeg(L);
     lua_pop(L, lua_gettop(L));  // pop off whatever lpeg leaves on the stack
 
-    L_SetupDebugTraceback(L);
-
     // create misc. global functions in the Lua state
-    lua_pushcfunction(L, SetEvent_luacf);
+    lua_pushcfunction(L, SetEvent_CF);
     lua_setglobal(L, "gameevent_internal");
-    lua_pushcfunction(L, SetActor_luacf);
+    lua_pushcfunction(L, SetActor_CF);
     lua_setglobal(L, "gameactor_internal");
 
     Bassert(lua_gettop(L)==0);
+
+    lua_pushcfunction(L, &our_traceback_CF);
 }
 
 // 0: success, <0: failure
 int32_t El_CreateState(L_State *estate, const char *name)
 {
     L_ErrorFunc = El_OnError;
+    L_OutOfMemFunc = El_OnOutOfMem;
 
     return L_CreateState(estate, name, &El_StateSetup);
 }
@@ -228,7 +255,7 @@ void El_DestroyState(L_State *estate)
 ////////// Lua_CFunctions //////////
 
 // gameevent(EVENT_..., lua_function)
-static int32_t SetEvent_luacf(lua_State *L)
+static int32_t SetEvent_CF(lua_State *L)
 {
     int32_t eventidx;
 
@@ -243,7 +270,7 @@ static int32_t SetEvent_luacf(lua_State *L)
 }
 
 // gameactor(actortile, strength, act, mov, movflags, lua_function)
-static int32_t SetActor_luacf(lua_State *L)
+static int32_t SetActor_CF(lua_State *L)
 {
     int32_t actortile, strength, movflags;
     const con_action_t *act;
@@ -281,8 +308,8 @@ static int32_t call_regd_function3(lua_State *L, void *keyaddr,
                                    int32_t iActor, int32_t iPlayer, int32_t lDist)
 {
     int32_t i;
-#ifdef DEBUGGINGAIDS
+#if !defined NDEBUG
-    L_PushDebugTraceback(L);
+    int32_t top = lua_gettop(L);
 #endif
     // get the Lua function from the registry
     lua_pushlightuserdata(L, keyaddr);
@@ -293,22 +320,24 @@ static int32_t call_regd_function3(lua_State *L, void *keyaddr,
     lua_pushinteger(L, lDist);
 
     // -- call it! --
-
 #ifdef DEBUGGINGAIDS
     i = lua_pcall(L, 3, 0, 1);
 #else
     i = lua_pcall(L, 3, 0, 0);
 #endif
 
-    if (i == LUA_ERRMEM)
+    Bassert(lua_gettop(L) == top+(i!=0));
-    {
-        lua_pop(L, 1);
-        // XXX: should be more sophisticated.  Clean up stack? Do GC?
-    }
 
     return i;
 }
 
+static int32_t g_eventIdx = 0;
+static void El_EventErrorPrint(const char *errmsg)
+{
+    OSD_Printf(OSD_ERROR "event \"%s\" runtime error: %s\n",
+               EventNames[g_eventIdx], errmsg);
+}
+
 int32_t El_CallEvent(L_State *estate, int32_t eventidx, int32_t iActor, int32_t iPlayer, int32_t lDist)
 {
     // XXX: estate must be the one where the events were registered...
@@ -321,29 +350,22 @@ int32_t El_CallEvent(L_State *estate, int32_t eventidx, int32_t iActor, int32_t
     i = call_regd_function3(L, &g_elEvents[eventidx], iActor, iPlayer, lDist);
     g_elCallDepth--;
 
-    if (i == LUA_ERRRUN)
+    if (i != 0)
     {
-        const char *errstr;
+        g_eventIdx = eventidx;
-
+        return L_HandleError(L, i, &El_EventErrorPrint);
-        if (lua_isboolean(L, -1))
-        {
-            lua_pop(L, 1);
-            return 0;
-        }
-
-        errstr = lua_tostring(L, -1);
-        Bassert(lua_type(L, -1)==LUA_TSTRING);
-        OSD_Printf(OSD_ERROR "event \"%s\" (state \"%s\") runtime error: %s\n",
-                   EventNames[eventidx], estate->name, errstr);
-        if (L_ErrorFunc)
-            L_ErrorFunc(errstr);
-        lua_pop(L, 1);
-        return -1;
     }
 
     return 0;
 }
 
+static int32_t g_actorTile, g_iActor;
+static void El_ActorErrorPrint(const char *errmsg)
+{
+    OSD_Printf(OSD_ERROR "actor %d (sprite %d) runtime error: %s\n",
+               g_actorTile, g_iActor, errmsg);
+}
+
 int32_t El_CallActor(L_State *estate, int32_t actortile, int32_t iActor, int32_t iPlayer, int32_t lDist)
 {
     lua_State *const L = estate->L;
@@ -353,25 +375,11 @@ int32_t El_CallActor(L_State *estate, int32_t actortile, int32_t iActor, int32_t
     i = call_regd_function3(L, &g_elActors[actortile], iActor, iPlayer, lDist);
     g_elCallDepth--;
 
-    if (i == LUA_ERRRUN)
+    if (i != 0)
     {
-        const char *errstr;
+        g_actorTile = actortile;
-
+        g_iActor = iActor;
-        if (lua_isboolean(L, -1))
+        return L_HandleError(L, i, &El_ActorErrorPrint);
-        {
-            int32_t killit = lua_toboolean(L, -1);
-            lua_pop(L, 1);
-            return killit;
-        }
-
-        Bassert(lua_type(L, -1)==LUA_TSTRING);
-        errstr = lua_tostring(L, -1);
-        OSD_Printf(OSD_ERROR "actor %d (sprite %d, state \"%s\") runtime error: %s\n",
-                   actortile, iActor, estate->name, errstr);
-        if (L_ErrorFunc)
-            L_ErrorFunc(errstr);
-        lua_pop(L, 1);
-        return -1;
     }
 
     return 0;

polymer/eduke32/source/lunatic/lunatic_m32.c

@@ -5,16 +5,9 @@
 #include "lunatic_m32.h"
 
 
-static void Em_StateSetup(lua_State *L)
-{
-    luaL_openlibs(L);
-    L_SetupDebugTraceback(L);
-}
-
-
 int Em_CreateState(L_State *estate)
 {
-    return L_CreateState(estate, "m32", &Em_StateSetup);
+    return L_CreateState(estate, "m32", NULL);
 }
 
 void Em_DestroyState(L_State *estate)