lua/lparser.h
2001-09-07 14:39:10 -03:00

89 lines
2.5 KiB
C

/*
** $Id: lparser.h,v 1.34 2001/08/27 15:16:28 roberto Exp $
** Lua Parser
** See Copyright Notice in lua.h
*/
#ifndef lparser_h
#define lparser_h
#include "llimits.h"
#include "lobject.h"
#include "ltable.h"
#include "lzio.h"
/* small implementation of bit arrays */
#define BPW (CHAR_BIT*sizeof(unsigned int)) /* bits per word */
#define words2bits(b) (((b)-1)/BPW + 1)
#define setbit(a, b) ((a)[(b)/BPW] |= (1 << (b)%BPW))
#define resetbit(a, b) ((a)[(b)/BPW] &= ~((1 << (b)%BPW)))
#define testbit(a, b) ((a)[(b)/BPW] & (1 << (b)%BPW))
/*
** Expression descriptor
*/
typedef enum {
VVOID, /* no value */
VNIL,
VNUMBER, /* n = value */
VK, /* info = index of constant in `k' */
VLOCAL, /* info = local register */
VUPVAL, /* info = index of upvalue in `upvalues' */
VGLOBAL, /* info = index of global name in `k' */
VINDEXED, /* info = table register; aux = index register (or `k') */
VRELOCABLE, /* info = instruction pc */
VNONRELOC, /* info = result register */
VJMP, /* info = result register */
VCALL /* info = result register */
} expkind;
typedef struct expdesc {
expkind k;
union {
struct {
int info, aux;
} i;
lua_Number n;
} u;
int t; /* patch list of `exit when true' */
int f; /* patch list of `exit when false' */
} expdesc;
/* 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 lua_State *L; /* copy of the Lua state */
int pc; /* next position to code (equivalent to `ncode') */
int lasttarget; /* `pc' of last `jump target' */
int jlt; /* list of jumps to `lasttarget' */
int freereg; /* first free register */
int nk; /* number of elements in `k' */
Hash *h; /* table to find (and reuse) elements in `k' */
int np; /* number of elements in `p' */
int nlineinfo; /* number of elements in `lineinfo' */
int nlocvars; /* number of elements in `locvars' */
int nactloc; /* number of active local variables */
int lastline; /* line where last `lineinfo' was generated */
struct Breaklabel *bl; /* chain of breakable blocks */
expdesc upvalues[MAXUPVALUES]; /* upvalues */
int actloc[MAXLOCALS]; /* local-variable stack (indices to locvars) */
unsigned int wasup[words2bits(MAXLOCALS)]; /* bit array to mark whether a
local variable was used as upvalue at some level */
} FuncState;
Proto *luaY_parser (lua_State *L, ZIO *z);
#endif