common/lualib.h

   1 /*
   2  * lualib.h - useful functions and type for Lua
   3  *
   4  * Copyright © 2009 Julien Danjou <julien@danjou.info>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  */
  21
  22 #ifndef AWESOME_COMMON_LUALIB
  23 #define AWESOME_COMMON_LUALIB
  24
  25 #include <lauxlib.h>
  26 #include "common/util.h"
  27
  28 /** Lua function to call on dofuction() error */
  29 lua_CFunction lualib_dofunction_on_error;
  30
  31 #define luaA_checkfunction(L, n) \
  32     do { \
  33         if(!lua_isfunction(L, n)) \
  34             luaL_typerror(L, n, "function"); \
  35     } while(0)
  36
  37 /** Dump the Lua stack. Useful for debugging.
  38  * \param L The Lua VM state.
  39  */
  40 static inline void
  41 luaA_dumpstack(lua_State *L)
  42 {
  43     fprintf(stderr, "-------- Lua stack dump ---------\n");
  44     for(int i = lua_gettop(L); i; i--)
  45     {
  46         int t = lua_type(L, i);
  47         switch (t)
  48         {
  49           case LUA_TSTRING:
  50             fprintf(stderr, "%d: string: `%s'\n", i, lua_tostring(L, i));
  51             break;
  52           case LUA_TBOOLEAN:
  53             fprintf(stderr, "%d: bool:   %s\n", i, lua_toboolean(L, i) ? "true" : "false");
  54             break;
  55           case LUA_TNUMBER:
  56             fprintf(stderr, "%d: number: %g\n", i, lua_tonumber(L, i));
  57             break;
  58           case LUA_TNIL:
  59             fprintf(stderr, "%d: nil\n", i);
  60             break;
  61           default:
  62             fprintf(stderr, "%d: %s\t#%d\t%p\n", i, lua_typename(L, t),
  63                     (int) lua_objlen(L, i),
  64                     lua_topointer(L, i));
  65             break;
  66         }
  67     }
  68     fprintf(stderr, "------- Lua stack dump end ------\n");
  69 }
  70
  71 /** Convert s stack index to positive.
  72  * \param L The Lua VM state.
  73  * \param ud The index.
  74  * \return A positive index.
  75  */
  76 static inline int
  77 luaA_absindex(lua_State *L, int ud)
  78 {
  79     return (ud > 0 || ud <= LUA_REGISTRYINDEX) ? ud : lua_gettop(L) + ud + 1;
  80 }
  81
  82 static inline int
  83 luaA_dofunction_error(lua_State *L)
  84 {
  85     if(lualib_dofunction_on_error)
  86         return lualib_dofunction_on_error(L);
  87     return 0;
  88 }
  89
  90 /** Execute an Lua function on top of the stack.
  91  * \param L The Lua stack.
  92  * \param nargs The number of arguments for the Lua function.
  93  * \param nret The number of returned value from the Lua function.
  94  * \return True on no error, false otherwise.
  95  */
  96 static inline bool
  97 luaA_dofunction(lua_State *L, int nargs, int nret)
  98 {
  99     /* Move function before arguments */
 100     lua_insert(L, - nargs - 1);
 101     /* Push error handling function */
 102     lua_pushcfunction(L, luaA_dofunction_error);
 103     /* Move error handling function before args and function */
 104     lua_insert(L, - nargs - 2);
 105     int error_func_pos = lua_gettop(L) - nargs - 1;
 106     if(lua_pcall(L, nargs, nret, - nargs - 2))
 107     {
 108         warn("%s", lua_tostring(L, -1));
 109         /* Remove error function and error string */
 110         lua_pop(L, 2);
 111         return false;
 112     }
 113     /* Remove error function */
 114     lua_remove(L, error_func_pos);
 115     return true;
 116 }
 117
 118 #define luaA_checktable(L, n) \
 119     do { \
 120         if(!lua_istable(L, n)) \
 121             luaL_typerror(L, n, "table"); \
 122     } while(0)
 123
 124 #endif
 125
 126 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=80