| 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 |