ba8b5c17 |
1 | /* |
2 | ** $Id: lparser.h,v 1.70 2012/05/08 13:53:33 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 | VNONRELOC, /* info = result register */ |
27 | VLOCAL, /* info = local register */ |
28 | VUPVAL, /* info = index of upvalue in 'upvalues' */ |
29 | VINDEXED, /* t = table register/upvalue; idx = index R/K */ |
30 | VJMP, /* info = instruction pc */ |
31 | VRELOCABLE, /* info = instruction pc */ |
32 | VCALL, /* info = instruction pc */ |
33 | VVARARG /* info = instruction pc */ |
34 | } expkind; |
35 | |
36 | |
37 | #define vkisvar(k) (VLOCAL <= (k) && (k) <= VINDEXED) |
38 | #define vkisinreg(k) ((k) == VNONRELOC || (k) == VLOCAL) |
39 | |
40 | typedef struct expdesc { |
41 | expkind k; |
42 | union { |
43 | struct { /* for indexed variables (VINDEXED) */ |
44 | short idx; /* index (R/K) */ |
45 | lu_byte t; /* table (register or upvalue) */ |
46 | lu_byte vt; /* whether 't' is register (VLOCAL) or upvalue (VUPVAL) */ |
47 | } ind; |
48 | int info; /* for generic use */ |
49 | lua_Number nval; /* for VKNUM */ |
50 | } u; |
51 | int t; /* patch list of `exit when true' */ |
52 | int f; /* patch list of `exit when false' */ |
53 | } expdesc; |
54 | |
55 | |
56 | /* description of active local variable */ |
57 | typedef struct Vardesc { |
58 | short idx; /* variable index in stack */ |
59 | } Vardesc; |
60 | |
61 | |
62 | /* description of pending goto statements and label statements */ |
63 | typedef struct Labeldesc { |
64 | TString *name; /* label identifier */ |
65 | int pc; /* position in code */ |
66 | int line; /* line where it appeared */ |
67 | lu_byte nactvar; /* local level where it appears in current block */ |
68 | } Labeldesc; |
69 | |
70 | |
71 | /* list of labels or gotos */ |
72 | typedef struct Labellist { |
73 | Labeldesc *arr; /* array */ |
74 | int n; /* number of entries in use */ |
75 | int size; /* array size */ |
76 | } Labellist; |
77 | |
78 | |
79 | /* dynamic structures used by the parser */ |
80 | typedef struct Dyndata { |
81 | struct { /* list of active local variables */ |
82 | Vardesc *arr; |
83 | int n; |
84 | int size; |
85 | } actvar; |
86 | Labellist gt; /* list of pending gotos */ |
87 | Labellist label; /* list of active labels */ |
88 | } Dyndata; |
89 | |
90 | |
91 | /* control of blocks */ |
92 | struct BlockCnt; /* defined in lparser.c */ |
93 | |
94 | |
95 | /* state needed to generate code for a given function */ |
96 | typedef struct FuncState { |
97 | Proto *f; /* current function header */ |
98 | Table *h; /* table to find (and reuse) elements in `k' */ |
99 | struct FuncState *prev; /* enclosing function */ |
100 | struct LexState *ls; /* lexical state */ |
101 | struct BlockCnt *bl; /* chain of current blocks */ |
102 | int pc; /* next position to code (equivalent to `ncode') */ |
103 | int lasttarget; /* 'label' of last 'jump label' */ |
104 | int jpc; /* list of pending jumps to `pc' */ |
105 | int nk; /* number of elements in `k' */ |
106 | int np; /* number of elements in `p' */ |
107 | int firstlocal; /* index of first local var (in Dyndata array) */ |
108 | short nlocvars; /* number of elements in 'f->locvars' */ |
109 | lu_byte nactvar; /* number of active local variables */ |
110 | lu_byte nups; /* number of upvalues */ |
111 | lu_byte freereg; /* first free register */ |
112 | } FuncState; |
113 | |
114 | |
115 | LUAI_FUNC Closure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff, |
116 | Dyndata *dyd, const char *name, int firstchar); |
117 | |
118 | |
119 | #endif |