src/lparser.h

   1 /*
   2 ** $Id: lparser.h,v 1.57.1.1 2007/12/27 13:02:25 roberto Exp $
   3 ** Lua Parser
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7 #ifndef lparser_h
   8 #define lparser_h
   9
  10 #include "llimits.h"
  11 #include "lobject.h"
  12 #include "lzio.h"
  13
  14
  15 /*
  16 ** Expression descriptor
  17 */
  18
  19 typedef enum {
  20   VVOID,        /* no value */
  21   VNIL,
  22   VTRUE,
  23   VFALSE,
  24   VK,           /* info = index of constant in `k' */
  25   VKNUM,        /* nval = numerical value */
  26   VLOCAL,       /* info = local register */
  27   VUPVAL,       /* info = index of upvalue in `upvalues' */
  28   VGLOBAL,      /* info = index of table; aux = index of global name in `k' */
  29   VINDEXED,     /* info = table register; aux = index register (or `k') */
  30   VJMP,         /* info = instruction pc */
  31   VRELOCABLE,   /* info = instruction pc */
  32   VNONRELOC,    /* info = result register */
  33   VCALL,        /* info = instruction pc */
  34   VVARARG       /* info = instruction pc */
  35 } expkind;
  36
  37 typedef struct expdesc {
  38   expkind k;
  39   union {
  40     struct { int info, aux; } s;
  41     lua_Number nval;
  42   } u;
  43   int t;  /* patch list of `exit when true' */
  44   int f;  /* patch list of `exit when false' */
  45 } expdesc;
  46
  47 typedef struct expdesc_list {
  48   struct expdesc_list *prev;
  49   expdesc v;  /* variable (global, local, upvalue, or indexed) */
  50 } expdesc_list;
  51
  52 typedef struct upvaldesc {
  53   lu_byte k;
  54   lu_byte info;
  55 } upvaldesc;
  56
  57
  58 struct BlockCnt;  /* defined in lparser.c */
  59
  60
  61 /* state needed to generate code for a given function */
  62 typedef struct FuncState {
  63   Proto *f;  /* current function header */
  64   Table *h;  /* table to find (and reuse) elements in `k' */
  65   struct FuncState *prev;  /* enclosing function */
  66   struct LexState *ls;  /* lexical state */
  67   struct lua_State *L;  /* copy of the Lua state */
  68   struct BlockCnt *bl;  /* chain of current blocks */
  69   expdesc_list *lhs;  /* chain of left hand sides during assign */
  70   short nlhs;  /* number of lhs in chain */
  71   short nrhs;  /* number of rhs in assignment */
  72   int pc;  /* next position to code (equivalent to `ncode') */
  73   int lasttarget;   /* `pc' of last `jump target' */
  74   int jpc;  /* list of pending jumps to `pc' */
  75   int freereg;  /* first free register */
  76   int nk;  /* number of elements in `k' */
  77   int np;  /* number of elements in `p' */
  78   short nlocvars;  /* number of elements in `locvars' */
  79   lu_byte nactvar;  /* number of active local variables */
  80   upvaldesc upvalues[LUAI_MAXUPVALUES];  /* upvalues */
  81   unsigned short actvar[LUAI_MAXVARS];  /* declared-variable stack */
  82 } FuncState;
  83
  84
  85 LUAI_FUNC Proto *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
  86                                             const char *name);
  87
  88
  89 #endif