/*
** $Id: lparser.h,v 1.74 2014/10/25 11:50:46 roberto Exp $
** Lua Parser
** See Copyright Notice in lua.h
*/
#ifndef lparser_h
#define lparser_h
#include "llimits.h"
#include "lobject.h"
#include "lzio.h"
/*
** Expression descriptor
*/
typedef enum {
  VVOID,        /* no value */
  VNIL,
  VTRUE,
  VFALSE,
  VK,           /* info = index of constant in 'k' */
  VKFLT,        /* nval = numerical float value */
  VKINT,        /* nval = numerical integer value */
  VNONRELOC,    /* info = result register */
  VLOCAL,       /* info = local register */
  VUPVAL,       /* info = index of upvalue in 'upvalues' */
  VINDEXED,     /* t = table register/upvalue; idx = index R/K */
  VJMP,         /* info = instruction pc */
  VRELOCABLE,   /* info = instruction pc */
  VCALL,        /* info = instruction pc */
  VVARARG       /* info = instruction pc */
} expkind;
#define vkisvar(k)      (VLOCAL <= (k) && (k) <= VINDEXED)
#define vkisinreg(k)    ((k) == VNONRELOC || (k) == VLOCAL)
typedef struct expdesc {
  expkind k;
  union {
    struct {  /* for indexed variables (VINDEXED) */
      short idx;  /* index (R/K) */
      lu_byte t;  /* table (register or upvalue) */
      lu_byte vt;  /* whether 't' is register (VLOCAL) or upvalue (VUPVAL) */
    } ind;
    int info;  /* for generic use */
    lua_Number nval;  /* for VKFLT */
    lua_Integer ival;    /* for VKINT */
  } u;
  int t;  /* patch list of 'exit when true' */
  int f;  /* patch list of 'exit when false' */
} expdesc;
/* description of active local variable */
typedef struct Vardesc {
  short idx;  /* variable index in stack */
} Vardesc;
/* description of pending goto statements and label statements */
typedef struct Labeldesc {
  TString *name;  /* label identifier */
  int pc;  /* position in code */
  int line;  /* line where it appeared */
  lu_byte nactvar;  /* local level where it appears in current block */
} Labeldesc;
/* list of labels or gotos */
typedef struct Labellist {
  Labeldesc *arr;  /* array */
  int n;  /* number of entries in use */
  int size;  /* array size */
} Labellist;
/* dynamic structures used by the parser */
typedef struct Dyndata {
  struct {  /* list of active local variables */
    Vardesc *arr;
    int n;
    int size;
  } actvar;
  Labellist gt;  /* list of pending gotos */
  Labellist label;   /* list of active labels */
} Dyndata;
/* control of blocks */
struct BlockCnt;  /* defined in lparser.c */
/* state needed to generate code for a given function */
typedef struct FuncState {
  Proto *f;  /* current function header */
  struct FuncState *prev;  /* enclosing function */
  struct LexState *ls;  /* lexical state */
  struct BlockCnt *bl;  /* chain of current blocks */
  int pc;  /* next position to code (equivalent to 'ncode') */
  int lasttarget;   /* 'label' of last 'jump label' */
  int jpc;  /* list of pending jumps to 'pc' */
  int nk;  /* number of elements in 'k' */
  int np;  /* number of elements in 'p' */
  int firstlocal;  /* index of first local var (in Dyndata array) */
  short nlocvars;  /* number of elements in 'f->locvars' */
  lu_byte nactvar;  /* number of active local variables */
  lu_byte nups;  /* number of upvalues */
  lu_byte freereg;  /* first free register */
} FuncState;
LUAI_FUNC LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
                                 Dyndata *dyd, const char *name, int firstchar);
#endif