src/blua/lapi.c

@@ -28,6 +28,7 @@
 #include "ltm.h"
 #include "lundump.h"
 #include "lvm.h"
+#include "lauxlib.h"
 
 
 
@@ -155,6 +156,11 @@ LUA_API lua_State *lua_newthread (lua_State *L) {
 ** basic stack manipulation
 */
 
+LUA_API int lua_absindex (lua_State *L, int i) {
+  if (i < 0 && i > LUA_REGISTRYINDEX)
+    i += lua_gettop(L) + 1;
+  return i;
+}
 
 LUA_API int lua_gettop (lua_State *L) {
   return cast_int(L->top - L->base);
@@ -979,6 +985,12 @@ LUA_API int lua_next (lua_State *L, int idx) {
   return more;
 }
 
+LUA_API void lua_copy (lua_State *L, int from, int to) {
+  int abs_to = lua_absindex(L, to);
+  luaL_checkstack(L, 1, "not enough stack slots");
+  lua_pushvalue(L, from);
+  lua_replace(L, abs_to);
+}
 
 LUA_API void lua_concat (lua_State *L, int n) {
   lua_lock(L);

src/blua/lauxlib.c

@@ -32,6 +32,111 @@
 #define abs_index(L, i)		((i) > 0 || (i) <= LUA_REGISTRYINDEX ? (i) : \
 					lua_gettop(L) + (i) + 1)
 
+/*
+** {======================================================
+** Traceback
+** =======================================================
+*/
+
+static int countlevels (lua_State *L) {
+  lua_Debug ar;
+  int li = 1, le = 1;
+  /* find an upper bound */
+  while (lua_getstack(L, le, &ar)) { li = le; le *= 2; }
+  /* do a binary search */
+  while (li < le) {
+    int m = (li + le)/2;
+    if (lua_getstack(L, m, &ar)) li = m + 1;
+    else le = m;
+  }
+  return le - 1;
+}
+
+static int findfield (lua_State *L, int objidx, int level) {
+  if (level == 0 || !lua_istable(L, -1))
+    return 0;  /* not found */
+  lua_pushnil(L);  /* start 'next' loop */
+  while (lua_next(L, -2)) {  /* for each pair in table */
+    if (lua_type(L, -2) == LUA_TSTRING) {  /* ignore non-string keys */
+      if (lua_rawequal(L, objidx, -1)) {  /* found object? */
+        lua_pop(L, 1);  /* remove value (but keep name) */
+        return 1;
+      }
+      else if (findfield(L, objidx, level - 1)) {  /* try recursively */
+        lua_remove(L, -2);  /* remove table (but keep name) */
+        lua_pushliteral(L, ".");
+        lua_insert(L, -2);  /* place '.' between the two names */
+        lua_concat(L, 3);
+        return 1;
+      }
+    }
+    lua_pop(L, 1);  /* remove value */
+  }
+  return 0;  /* not found */
+}
+
+static int pushglobalfuncname (lua_State *L, lua_Debug *ar) {
+  int top = lua_gettop(L);
+  lua_getinfo(L, "f", ar);  /* push function */
+  lua_pushvalue(L, LUA_GLOBALSINDEX);
+  if (findfield(L, top + 1, 2)) {
+    lua_copy(L, -1, top + 1);  /* move name to proper place */
+    lua_pop(L, 2);  /* remove pushed values */
+    return 1;
+  }
+  else {
+    lua_settop(L, top);  /* remove function and global table */
+    return 0;
+  }
+}
+
+static void pushfuncname (lua_State *L, lua_Debug *ar) {
+  if (*ar->namewhat != '\0')  /* is there a name? */
+    lua_pushfstring(L, "function " LUA_QS, ar->name);
+  else if (*ar->what == 'm')  /* main? */
+      lua_pushliteral(L, "main chunk");
+  else if (*ar->what == 'C') {
+    if (pushglobalfuncname(L, ar)) {
+      lua_pushfstring(L, "function " LUA_QS, lua_tostring(L, -1));
+      lua_remove(L, -2);  /* remove name */
+    }
+    else
+      lua_pushliteral(L, "?");
+  }
+  else
+    lua_pushfstring(L, "function <%s:%d>", ar->short_src, ar->linedefined);
+}
+
+#define LEVELS1 12  /* size of the first part of the stack */
+#define LEVELS2 10  /* size of the second part of the stack */
+
+void luaL_traceback (lua_State *L, lua_State *L1,
+                                const char *msg, int level) {
+  lua_Debug ar;
+  int top = lua_gettop(L);
+  int numlevels = countlevels(L1);
+  int mark = (numlevels > LEVELS1 + LEVELS2) ? LEVELS1 : 0;
+  if (msg) lua_pushfstring(L, "%s\n", msg);
+  lua_pushliteral(L, "stack traceback:");
+  while (lua_getstack(L1, level++, &ar)) {
+    if (level == mark) {  /* too many levels? */
+      lua_pushliteral(L, "\n\t...");  /* add a '...' */
+      level = numlevels - LEVELS2;  /* and skip to last ones */
+    }
+    else {
+      lua_getinfo(L1, "Slnt", &ar);
+      lua_pushfstring(L, "\n\t%s:", ar.short_src);
+      if (ar.currentline > 0)
+        lua_pushfstring(L, "%d:", ar.currentline);
+      lua_pushliteral(L, " in ");
+      pushfuncname(L, &ar);
+      lua_concat(L, lua_gettop(L) - top);
+    }
+  }
+  lua_concat(L, lua_gettop(L) - top);
+}
+
+/* }====================================================== */
 
 /*
 ** {======================================================

src/blua/lauxlib.h

@@ -39,6 +39,8 @@ typedef struct luaL_Reg {
 
 
 
+LUALIB_API void (luaL_traceback) (lua_State *L, lua_State *L1,
+                                const char *msg, int level);
 LUALIB_API void (luaI_openlib) (lua_State *L, const char *libname,
                                 const luaL_Reg *l, int nup);
 LUALIB_API void (luaL_register) (lua_State *L, const char *libname,

src/blua/lua.h

@@ -117,6 +117,7 @@ LUA_API lua_CFunction (lua_atpanic) (lua_State *L, lua_CFunction panicf);
 /*
 ** basic stack manipulation
 */
+LUA_API int   (lua_absindex) (lua_State *L, int i);
 LUA_API int   (lua_gettop) (lua_State *L);
 LUA_API void  (lua_settop) (lua_State *L, int idx);
 LUA_API void  (lua_pushvalue) (lua_State *L, int idx);
@@ -238,7 +239,7 @@ LUA_API int (lua_gc) (lua_State *L, int what, int data);
 LUA_API int   (lua_error) (lua_State *L);
 
 LUA_API int   (lua_next) (lua_State *L, int idx);
-
+LUA_API void  (lua_copy) (lua_State *L, int from, int to);
 LUA_API void  (lua_concat) (lua_State *L, int n);
 
 LUA_API lua_Alloc (lua_getallocf) (lua_State *L, void **ud);

src/d_netcmd.c

@@ -43,6 +43,7 @@
 #include "mserv.h"
 #include "z_zone.h"
 #include "lua_script.h"
+#include "lua_libs.h"
 #include "lua_hook.h"
 #include "m_cond.h"
 #include "m_anigif.h"
@@ -4597,4 +4598,4 @@ static void BaseNumLaps_OnChange(void)
 		else
 			CONS_Printf(M_GetText("Number of laps will be changed to %d next round.\n"), cv_basenumlaps.value);
 	}
-}
+}
\ No newline at end of file

src/lua_script.c

@@ -36,6 +36,8 @@
 
 lua_State *gL = NULL;
 
+int tracebackidx;
+
 // List of internal libraries to load from SRB2
 static lua_CFunction liblist[] = {
 	LUA_EnumLib, // global metatable for enums
@@ -397,6 +399,14 @@ void LUA_ClearExtVars(void)
 // (i.e. they were called in hooks or coroutines etc)
 boolean lua_lumploading = false;
 
+int LUA_Traceback(lua_State *L)
+{
+	CONS_Alert(CONS_WARNING,"%s\n",lua_tostring(gL,-1));
+	luaL_traceback(L, L, NULL, 1);
+	CONS_Printf("%s\n", lua_tostring(L, -1));
+	return 1;
+}
+
 // Load a script from a MYFILE
 static inline void LUA_LoadFile(MYFILE *f, char *name)
 {
@@ -407,13 +417,15 @@ static inline void LUA_LoadFile(MYFILE *f, char *name)
 		LUA_ClearState();
 	lua_pushinteger(gL, f->wad);
 	lua_setfield(gL, LUA_REGISTRYINDEX, "WAD");
+	lua_pushcfunction(gL, LUA_Traceback);
+	tracebackidx = lua_gettop(gL);
 
 	lua_lumploading = true; // turn on loading flag
 
-	if (luaL_loadbuffer(gL, f->data, f->size, va("@%s",name)) || lua_pcall(gL, 0, 0, 0)) {
-		CONS_Alert(CONS_WARNING,"%s\n",lua_tostring(gL,-1));
+	if (luaL_loadbuffer(gL, f->data, f->size, va("@%s",name)) || lua_pcall(gL, 0, 0, tracebackidx)) {
 		lua_pop(gL,1);
 	}
+	lua_remove(gL, tracebackidx);
 	lua_gc(gL, LUA_GCCOLLECT, 0);
 
 	lua_lumploading = false; // turn off again

src/lua_script.h

@@ -37,7 +37,9 @@
 void LUA_ClearExtVars(void);
 #endif
 
+extern int LUA_Traceback(lua_State *L);
 extern boolean lua_lumploading; // is LUA_LoadLump being called?
+extern int tracebackidx;
 
 void LUA_LoadLump(UINT16 wad, UINT16 lump);
 #ifdef LUA_ALLOW_BYTECODE
@@ -66,8 +68,9 @@ void COM_Lua_f(void);
 
 #define LUA_Call(L,a)\
 {\
-	if (lua_pcall(L, a, 0, 0)) {\
-		CONS_Alert(CONS_WARNING,"%s\n",lua_tostring(L,-1));\
+	lua_pushcfunction(L, LUA_Traceback); \
+	tracebackidx = lua_gettop(L); \
+	if (lua_pcall(L, a, 0, tracebackidx)) {\
 		lua_pop(L, 1);\
 	}\
 }