standard libraries in packages

ldblib.c

@@ -1,5 +1,5 @@
 /*
-** $Id: ldblib.c,v 1.1 2001/11/29 22:14:34 rieru Exp rieru $
+** $Id: ldblib.c,v 1.43 2002/02/07 17:24:32 roberto Exp roberto $
 ** Interface from Lua to its debug API
 ** See Copyright Notice in lua.h
 */
@@ -167,17 +167,105 @@ static int setlinehook (lua_State *L) {
 }
 
 
+static int debug (lua_State *L) {
+  for (;;) {
+    char buffer[250];
+    fprintf(stderr, "lua_debug> ");
+    if (fgets(buffer, sizeof(buffer), stdin) == 0 ||
+        strcmp(buffer, "cont\n") == 0)
+      return 0;
+    lua_dostring(L, buffer);
+    lua_settop(L, 0);  /* remove eventual returns */
+  }
+}
+
+
+#define LEVELS1	12	/* size of the first part of the stack */
+#define LEVELS2	10	/* size of the second part of the stack */
+
+static int errorfb (lua_State *L) {
+  int level = 1;  /* skip level 0 (it's this function) */
+  int firstpart = 1;  /* still before eventual `...' */
+  lua_Debug ar;
+  luaL_Buffer b;
+  luaL_buffinit(L, &b);
+  luaL_addstring(&b, "error: ");
+  luaL_addstring(&b, luaL_check_string(L, 1));
+  luaL_addstring(&b, "\n");
+  while (lua_getstack(L, level++, &ar)) {
+    char buff[120];  /* enough to fit following `sprintf's */
+    if (level == 2)
+      luaL_addstring(&b, "stack traceback:\n");
+    else if (level > LEVELS1 && firstpart) {
+      /* no more than `LEVELS2' more levels? */
+      if (!lua_getstack(L, level+LEVELS2, &ar))
+        level--;  /* keep going */
+      else {
+        luaL_addstring(&b, "       ...\n");  /* too many levels */
+        while (lua_getstack(L, level+LEVELS2, &ar))  /* find last levels */
+          level++;
+      }
+      firstpart = 0;
+      continue;
+    }
+    sprintf(buff, "%4d:  ", level-1);
+    luaL_addstring(&b, buff);
+    lua_getinfo(L, "Snl", &ar);
+    switch (*ar.namewhat) {
+      case 'g':  case 'l':  /* global, local */
+        sprintf(buff, "function `%.50s'", ar.name);
+        break;
+      case 'f':  /* field */
+        sprintf(buff, "method `%.50s'", ar.name);
+        break;
+      case 't':  /* tag method */
+        sprintf(buff, "`%.50s' tag method", ar.name);
+        break;
+      default: {
+        if (*ar.what == 'm')  /* main? */
+          sprintf(buff, "main of %.70s", ar.short_src);
+        else if (*ar.what == 'C')  /* C function? */
+          sprintf(buff, "%.70s", ar.short_src);
+        else
+          sprintf(buff, "function <%d:%.70s>", ar.linedefined, ar.short_src);
+        ar.source = NULL;  /* do not print source again */
+      }
+    }
+    luaL_addstring(&b, buff);
+    if (ar.currentline > 0) {
+      sprintf(buff, " at line %d", ar.currentline);
+      luaL_addstring(&b, buff);
+    }
+    if (ar.source) {
+      sprintf(buff, " [%.70s]", ar.short_src);
+      luaL_addstring(&b, buff);
+    }
+    luaL_addstring(&b, "\n");
+  }
+  luaL_pushresult(&b);
+  lua_getglobal(L, LUA_ALERT);
+  if (lua_isfunction(L, -1)) {  /* avoid loop if _ALERT is not defined */
+    lua_pushvalue(L, -2);  /* error message */
+    lua_rawcall(L, 1, 0);
+  }
+  return 0;
+}
+
+
 static const luaL_reg dblib[] = {
   {"getlocal", getlocal},
   {"getinfo", getinfo},
   {"setcallhook", setcallhook},
   {"setlinehook", setlinehook},
-  {"setlocal", setlocal}
+  {"setlocal", setlocal},
+  {"debug", debug},
+  {NULL, NULL}
 };
 
 
 LUALIB_API int lua_dblibopen (lua_State *L) {
-  luaL_openl(L, dblib);
+  luaL_opennamedlib(L, "dbg", dblib);
+  lua_register(L, LUA_ERRORMESSAGE, errorfb);
   return 0;
 }