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 
48 typedef struct upvaldesc {
49   lu_byte k;
50   lu_byte info;
51 } upvaldesc;
52 
53 
54 struct BlockCnt;  /* defined in lparser.c */
55 
56 
57 /* state needed to generate code for a given function */
58 typedef struct FuncState {
59   Proto *f;  /* current function header */
60   Table *h;  /* table to find (and reuse) elements in `k' */
61   struct FuncState *prev;  /* enclosing function */
62   struct LexState *ls;  /* lexical state */
63   struct lua_State *L;  /* copy of the Lua state */
64   struct BlockCnt *bl;  /* chain of current blocks */
65   int pc;  /* next position to code (equivalent to `ncode') */
66   int lasttarget;   /* `pc' of last `jump target' */
67   int jpc;  /* list of pending jumps to `pc' */
68   int freereg;  /* first free register */
69   int nk;  /* number of elements in `k' */
70   int np;  /* number of elements in `p' */
71   short nlocvars;  /* number of elements in `locvars' */
72   lu_byte nactvar;  /* number of active local variables */
73   upvaldesc upvalues[LUAI_MAXUPVALUES];  /* upvalues */
74   unsigned short actvar[LUAI_MAXVARS];  /* declared-variable stack */
75 } FuncState;
76 
77 
78 LUAI_FUNC Proto *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
79                                             const char *name);
80 
81 
82 #endif
83