1/* BEGIN CSTYLED */
2/*
3** $Id: lparser.h,v 1.70.1.1 2013/04/12 18:48:47 roberto Exp $
4** Lua Parser
5** See Copyright Notice in lua.h
6*/
7
8#ifndef lparser_h
9#define lparser_h
10
11#include "llimits.h"
12#include "lobject.h"
13#include "lzio.h"
14
15
16/*
17** Expression descriptor
18*/
19
20typedef enum {
21  VVOID,	/* no value */
22  VNIL,
23  VTRUE,
24  VFALSE,
25  VK,		/* info = index of constant in `k' */
26  VKNUM,	/* nval = numerical value */
27  VNONRELOC,	/* info = result register */
28  VLOCAL,	/* info = local register */
29  VUPVAL,       /* info = index of upvalue in 'upvalues' */
30  VINDEXED,	/* t = table register/upvalue; idx = index R/K */
31  VJMP,		/* info = instruction pc */
32  VRELOCABLE,	/* info = instruction pc */
33  VCALL,	/* info = instruction pc */
34  VVARARG	/* info = instruction pc */
35} expkind;
36
37
38#define vkisvar(k)	(VLOCAL <= (k) && (k) <= VINDEXED)
39#define vkisinreg(k)	((k) == VNONRELOC || (k) == VLOCAL)
40
41typedef struct expdesc {
42  expkind k;
43  union {
44    struct {  /* for indexed variables (VINDEXED) */
45      short idx;  /* index (R/K) */
46      lu_byte t;  /* table (register or upvalue) */
47      lu_byte vt;  /* whether 't' is register (VLOCAL) or upvalue (VUPVAL) */
48    } ind;
49    int info;  /* for generic use */
50    lua_Number nval;  /* for VKNUM */
51  } u;
52  int t;  /* patch list of `exit when true' */
53  int f;  /* patch list of `exit when false' */
54} expdesc;
55
56
57/* description of active local variable */
58typedef struct Vardesc {
59  short idx;  /* variable index in stack */
60} Vardesc;
61
62
63/* description of pending goto statements and label statements */
64typedef struct Labeldesc {
65  TString *name;  /* label identifier */
66  int pc;  /* position in code */
67  int line;  /* line where it appeared */
68  lu_byte nactvar;  /* local level where it appears in current block */
69} Labeldesc;
70
71
72/* list of labels or gotos */
73typedef struct Labellist {
74  Labeldesc *arr;  /* array */
75  int n;  /* number of entries in use */
76  int size;  /* array size */
77} Labellist;
78
79
80/* dynamic structures used by the parser */
81typedef struct Dyndata {
82  struct {  /* list of active local variables */
83    Vardesc *arr;
84    int n;
85    int size;
86  } actvar;
87  Labellist gt;  /* list of pending gotos */
88  Labellist label;   /* list of active labels */
89} Dyndata;
90
91
92/* control of blocks */
93struct BlockCnt;  /* defined in lparser.c */
94
95
96/* state needed to generate code for a given function */
97typedef struct FuncState {
98  Proto *f;  /* current function header */
99  Table *h;  /* table to find (and reuse) elements in `k' */
100  struct FuncState *prev;  /* enclosing function */
101  struct LexState *ls;  /* lexical state */
102  struct BlockCnt *bl;  /* chain of current blocks */
103  int pc;  /* next position to code (equivalent to `ncode') */
104  int lasttarget;   /* 'label' of last 'jump label' */
105  int jpc;  /* list of pending jumps to `pc' */
106  int nk;  /* number of elements in `k' */
107  int np;  /* number of elements in `p' */
108  int firstlocal;  /* index of first local var (in Dyndata array) */
109  short nlocvars;  /* number of elements in 'f->locvars' */
110  lu_byte nactvar;  /* number of active local variables */
111  lu_byte nups;  /* number of upvalues */
112  lu_byte freereg;  /* first free register */
113} FuncState;
114
115
116LUAI_FUNC Closure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
117                                Dyndata *dyd, const char *name, int firstchar);
118
119
120#endif
121/* END CSTYLED */
122