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 20 typedef 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 41 typedef 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 */ 58 typedef struct Vardesc { 59 short idx; /* variable index in stack */ 60 } Vardesc; 61 62 63 /* description of pending goto statements and label statements */ 64 typedef 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 */ 73 typedef 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 */ 81 typedef 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 */ 93 struct BlockCnt; /* defined in lparser.c */ 94 95 96 /* state needed to generate code for a given function */ 97 typedef 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; 114 115 116 LUAI_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