misc/liblua/ldblib.c
author unc0rr
Sun, 02 Dec 2012 01:25:11 +0400
changeset 8178 8bd087478b48
parent 3697 d5b30d6373fc
child 10017 de822cd3df3a
permissions -rw-r--r--
Fix QSettings problems: - Reopen file in ReadOnly mode if it was open in ReadWrite mode and is being read. This is needed for stupid QSettings which opens file in ReadWrite mode just to call readAll() on it. - Implement setSize(0)

/*
** $Id: ldblib.c,v 1.104.1.3 2008/01/21 13:11:21 roberto Exp $
** Interface from Lua to its debug API
** See Copyright Notice in lua.h
*/


#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define ldblib_c
#define LUA_LIB

#include "lua.h"

#include "lauxlib.h"
#include "lualib.h"



static int db_getregistry (lua_State *L) {
  lua_pushvalue(L, LUA_REGISTRYINDEX);
  return 1;
}


static int db_getmetatable (lua_State *L) {
  luaL_checkany(L, 1);
  if (!lua_getmetatable(L, 1)) {
    lua_pushnil(L);  /* no metatable */
  }
  return 1;
}


static int db_setmetatable (lua_State *L) {
  int t = lua_type(L, 2);
  luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
                    "nil or table expected");
  lua_settop(L, 2);
  lua_pushboolean(L, lua_setmetatable(L, 1));
  return 1;
}


static int db_getfenv (lua_State *L) {
  lua_getfenv(L, 1);
  return 1;
}


static int db_setfenv (lua_State *L) {
  luaL_checktype(L, 2, LUA_TTABLE);
  lua_settop(L, 2);
  if (lua_setfenv(L, 1) == 0)
    luaL_error(L, LUA_QL("setfenv")
                  " cannot change environment of given object");
  return 1;
}


static void settabss (lua_State *L, const char *i, const char *v) {
  lua_pushstring(L, v);
  lua_setfield(L, -2, i);
}


static void settabsi (lua_State *L, const char *i, int v) {
  lua_pushinteger(L, v);
  lua_setfield(L, -2, i);
}


static lua_State *getthread (lua_State *L, int *arg) {
  if (lua_isthread(L, 1)) {
    *arg = 1;
    return lua_tothread(L, 1);
  }
  else {
    *arg = 0;
    return L;
  }
}


static void treatstackoption (lua_State *L, lua_State *L1, const char *fname) {
  if (L == L1) {
    lua_pushvalue(L, -2);
    lua_remove(L, -3);
  }
  else
    lua_xmove(L1, L, 1);
  lua_setfield(L, -2, fname);
}


static int db_getinfo (lua_State *L) {
  lua_Debug ar;
  int arg;
  lua_State *L1 = getthread(L, &arg);
  const char *options = luaL_optstring(L, arg+2, "flnSu");
  if (lua_isnumber(L, arg+1)) {
    if (!lua_getstack(L1, (int)lua_tointeger(L, arg+1), &ar)) {
      lua_pushnil(L);  /* level out of range */
      return 1;
    }
  }
  else if (lua_isfunction(L, arg+1)) {
    lua_pushfstring(L, ">%s", options);
    options = lua_tostring(L, -1);
    lua_pushvalue(L, arg+1);
    lua_xmove(L, L1, 1);
  }
  else
    return luaL_argerror(L, arg+1, "function or level expected");
  if (!lua_getinfo(L1, options, &ar))
    return luaL_argerror(L, arg+2, "invalid option");
  lua_createtable(L, 0, 2);
  if (strchr(options, 'S')) {
    settabss(L, "source", ar.source);
    settabss(L, "short_src", ar.short_src);
    settabsi(L, "linedefined", ar.linedefined);
    settabsi(L, "lastlinedefined", ar.lastlinedefined);
    settabss(L, "what", ar.what);
  }
  if (strchr(options, 'l'))
    settabsi(L, "currentline", ar.currentline);
  if (strchr(options, 'u'))
    settabsi(L, "nups", ar.nups);
  if (strchr(options, 'n')) {
    settabss(L, "name", ar.name);
    settabss(L, "namewhat", ar.namewhat);
  }
  if (strchr(options, 'L'))
    treatstackoption(L, L1, "activelines");
  if (strchr(options, 'f'))
    treatstackoption(L, L1, "func");
  return 1;  /* return table */
}


static int db_getlocal (lua_State *L) {
  int arg;
  lua_State *L1 = getthread(L, &arg);
  lua_Debug ar;
  const char *name;
  if (!lua_getstack(L1, luaL_checkint(L, arg+1), &ar))  /* out of range? */
    return luaL_argerror(L, arg+1, "level out of range");
  name = lua_getlocal(L1, &ar, luaL_checkint(L, arg+2));
  if (name) {
    lua_xmove(L1, L, 1);
    lua_pushstring(L, name);
    lua_pushvalue(L, -2);
    return 2;
  }
  else {
    lua_pushnil(L);
    return 1;
  }
}


static int db_setlocal (lua_State *L) {
  int arg;
  lua_State *L1 = getthread(L, &arg);
  lua_Debug ar;
  if (!lua_getstack(L1, luaL_checkint(L, arg+1), &ar))  /* out of range? */
    return luaL_argerror(L, arg+1, "level out of range");
  luaL_checkany(L, arg+3);
  lua_settop(L, arg+3);
  lua_xmove(L, L1, 1);
  lua_pushstring(L, lua_setlocal(L1, &ar, luaL_checkint(L, arg+2)));
  return 1;
}


static int auxupvalue (lua_State *L, int get) {
  const char *name;
  int n = luaL_checkint(L, 2);
  luaL_checktype(L, 1, LUA_TFUNCTION);
  if (lua_iscfunction(L, 1)) return 0;  /* cannot touch C upvalues from Lua */
  name = get ? lua_getupvalue(L, 1, n) : lua_setupvalue(L, 1, n);
  if (name == NULL) return 0;
  lua_pushstring(L, name);
  lua_insert(L, -(get+1));
  return get + 1;
}


static int db_getupvalue (lua_State *L) {
  return auxupvalue(L, 1);
}


static int db_setupvalue (lua_State *L) {
  luaL_checkany(L, 3);
  return auxupvalue(L, 0);
}



static const char KEY_HOOK = 'h';


static void hookf (lua_State *L, lua_Debug *ar) {
  static const char *const hooknames[] =
    {"call", "return", "line", "count", "tail return"};
  lua_pushlightuserdata(L, (void *)&KEY_HOOK);
  lua_rawget(L, LUA_REGISTRYINDEX);
  lua_pushlightuserdata(L, L);
  lua_rawget(L, -2);
  if (lua_isfunction(L, -1)) {
    lua_pushstring(L, hooknames[(int)ar->event]);
    if (ar->currentline >= 0)
      lua_pushinteger(L, ar->currentline);
    else lua_pushnil(L);
    lua_assert(lua_getinfo(L, "lS", ar));
    lua_call(L, 2, 0);
  }
}


static int makemask (const char *smask, int count) {
  int mask = 0;
  if (strchr(smask, 'c')) mask |= LUA_MASKCALL;
  if (strchr(smask, 'r')) mask |= LUA_MASKRET;
  if (strchr(smask, 'l')) mask |= LUA_MASKLINE;
  if (count > 0) mask |= LUA_MASKCOUNT;
  return mask;
}


static char *unmakemask (int mask, char *smask) {
  int i = 0;
  if (mask & LUA_MASKCALL) smask[i++] = 'c';
  if (mask & LUA_MASKRET) smask[i++] = 'r';
  if (mask & LUA_MASKLINE) smask[i++] = 'l';
  smask[i] = '\0';
  return smask;
}


static void gethooktable (lua_State *L) {
  lua_pushlightuserdata(L, (void *)&KEY_HOOK);
  lua_rawget(L, LUA_REGISTRYINDEX);
  if (!lua_istable(L, -1)) {
    lua_pop(L, 1);
    lua_createtable(L, 0, 1);
    lua_pushlightuserdata(L, (void *)&KEY_HOOK);
    lua_pushvalue(L, -2);
    lua_rawset(L, LUA_REGISTRYINDEX);
  }
}


static int db_sethook (lua_State *L) {
  int arg, mask, count;
  lua_Hook func;
  lua_State *L1 = getthread(L, &arg);
  if (lua_isnoneornil(L, arg+1)) {
    lua_settop(L, arg+1);
    func = NULL; mask = 0; count = 0;  /* turn off hooks */
  }
  else {
    const char *smask = luaL_checkstring(L, arg+2);
    luaL_checktype(L, arg+1, LUA_TFUNCTION);
    count = luaL_optint(L, arg+3, 0);
    func = hookf; mask = makemask(smask, count);
  }
  gethooktable(L);
  lua_pushlightuserdata(L, L1);
  lua_pushvalue(L, arg+1);
  lua_rawset(L, -3);  /* set new hook */
  lua_pop(L, 1);  /* remove hook table */
  lua_sethook(L1, func, mask, count);  /* set hooks */
  return 0;
}


static int db_gethook (lua_State *L) {
  int arg;
  lua_State *L1 = getthread(L, &arg);
  char buff[5];
  int mask = lua_gethookmask(L1);
  lua_Hook hook = lua_gethook(L1);
  if (hook != NULL && hook != hookf)  /* external hook? */
    lua_pushliteral(L, "external hook");
  else {
    gethooktable(L);
    lua_pushlightuserdata(L, L1);
    lua_rawget(L, -2);   /* get hook */
    lua_remove(L, -2);  /* remove hook table */
  }
  lua_pushstring(L, unmakemask(mask, buff));
  lua_pushinteger(L, lua_gethookcount(L1));
  return 3;
}


static int db_debug (lua_State *L) {
  for (;;) {
    char buffer[250];
    fputs("lua_debug> ", stderr);
    if (fgets(buffer, sizeof(buffer), stdin) == 0 ||
        strcmp(buffer, "cont\n") == 0)
      return 0;
    if (luaL_loadbuffer(L, buffer, strlen(buffer), "=(debug command)") ||
        lua_pcall(L, 0, 0, 0)) {
      fputs(lua_tostring(L, -1), stderr);
      fputs("\n", stderr);
    }
    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 db_errorfb (lua_State *L) {
  int level;
  int firstpart = 1;  /* still before eventual `...' */
  int arg;
  lua_State *L1 = getthread(L, &arg);
  lua_Debug ar;
  if (lua_isnumber(L, arg+2)) {
    level = (int)lua_tointeger(L, arg+2);
    lua_pop(L, 1);
  }
  else
    level = (L == L1) ? 1 : 0;  /* level 0 may be this own function */
  if (lua_gettop(L) == arg)
    lua_pushliteral(L, "");
  else if (!lua_isstring(L, arg+1)) return 1;  /* message is not a string */
  else lua_pushliteral(L, "\n");
  lua_pushliteral(L, "stack traceback:");
  while (lua_getstack(L1, level++, &ar)) {
    if (level > LEVELS1 && firstpart) {
      /* no more than `LEVELS2' more levels? */
      if (!lua_getstack(L1, level+LEVELS2, &ar))
        level--;  /* keep going */
      else {
        lua_pushliteral(L, "\n\t...");  /* too many levels */
        while (lua_getstack(L1, level+LEVELS2, &ar))  /* find last levels */
          level++;
      }
      firstpart = 0;
      continue;
    }
    lua_pushliteral(L, "\n\t");
    lua_getinfo(L1, "Snl", &ar);
    lua_pushfstring(L, "%s:", ar.short_src);
    if (ar.currentline > 0)
      lua_pushfstring(L, "%d:", ar.currentline);
    if (*ar.namewhat != '\0')  /* is there a name? */
        lua_pushfstring(L, " in function " LUA_QS, ar.name);
    else {
      if (*ar.what == 'm')  /* main? */
        lua_pushfstring(L, " in main chunk");
      else if (*ar.what == 'C' || *ar.what == 't')
        lua_pushliteral(L, " ?");  /* C function or tail call */
      else
        lua_pushfstring(L, " in function <%s:%d>",
                           ar.short_src, ar.linedefined);
    }
    lua_concat(L, lua_gettop(L) - arg);
  }
  lua_concat(L, lua_gettop(L) - arg);
  return 1;
}


static const luaL_Reg dblib[] = {
  {"debug", db_debug},
  {"getfenv", db_getfenv},
  {"gethook", db_gethook},
  {"getinfo", db_getinfo},
  {"getlocal", db_getlocal},
  {"getregistry", db_getregistry},
  {"getmetatable", db_getmetatable},
  {"getupvalue", db_getupvalue},
  {"setfenv", db_setfenv},
  {"sethook", db_sethook},
  {"setlocal", db_setlocal},
  {"setmetatable", db_setmetatable},
  {"setupvalue", db_setupvalue},
  {"traceback", db_errorfb},
  {NULL, NULL}
};


LUALIB_API int luaopen_debug (lua_State *L) {
  luaL_register(L, LUA_DBLIBNAME, dblib);
  return 1;
}