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 120