static int gettraceback(lua_State* l) {
lua_checkstack(l, 5);
char errormsg[2048] = "";
// obtain the error first:
const char* p = lua_tostring(l, -1);
if (p) {
unsigned int i = strlen(p);
if (i >= sizeof(errormsg)) {i = sizeof(errormsg)-1;}
memcpy(errormsg, p, i);
errormsg[i] = 0;
}
lua_pop(l, 1);
// add a line break if we can
if (strlen(errormsg) + strlen("\n") < sizeof(errormsg)) {
strcat(errormsg, "\n");
}
// call the original debug.traceback
lua_pushstring(l, "debug_traceback_preserved");
lua_gettable(l, LUA_REGISTRYINDEX);
if (lua_type(l, -1) != LUA_TFUNCTION) { // make sure it is valid
// oops.
char invaliddebugtraceback[] = "OOPS: The debug traceback "
"couldn't be generated:\n"
" Traceback function is not present or invalid (lua type is '";
if (strlen(errormsg) + strlen(invaliddebugtraceback) <
sizeof(errormsg)) {
strcat(errormsg, invaliddebugtraceback);
}
// clarify on the invalid type of the function (which is not a func):
char typebuf[64] = "";
luatypetoname(lua_type(l, -1), typebuf, 16);
strcat(typebuf, "')");
if (strlen(errormsg) + strlen(typebuf) < sizeof(errormsg)) {
strcat(errormsg, typebuf);
}
// pop non-function:
lua_pop(l, 1);
// push error:
lua_pushstring(l, errormsg);
return 1;
}
lua_call(l, 0, 1);
// add the traceback as much as we can
p = lua_tostring(l, -1);
if (p) {
int len = strlen(p);
if (strlen(errormsg) + len >= sizeof(errormsg)) {
len = sizeof(errormsg) - strlen(errormsg) - 1;
}
if (len > 0) {
int offset = strlen(errormsg);
memcpy(errormsg + offset, p, len);
errormsg[offset + len] = 0;
}
}
lua_pop(l, 1); // pop traceback
// push the whole result
lua_pushstring(l, errormsg);
return 1;
}
const char* lua_strtype(lua_State* l, int stack) {
int type = lua_type(l, stack);
luatypetoname(type, strtypebuf, sizeof(strtypebuf));
return strtypebuf;
}
