1 /* 2 ** $Id: lparser.h,v 1.70.1.1 2013/04/12 18:48:47 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 ** Expression descriptor 16 */ 17 18 typedef enum 19 { 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 #define vkisvar(k) (VLOCAL <= (k) && (k) <= VINDEXED) 37 #define vkisinreg(k) ((k) == VNONRELOC || (k) == VLOCAL) 38 39 typedef struct expdesc 40 { 41 expkind k; 42 union { 43 struct 44 { /* 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 /* description of active local variable */ 57 typedef struct Vardesc 58 { 59 short idx; /* variable index in stack */ 60 } Vardesc; 61 62 /* description of pending goto statements and label statements */ 63 typedef struct Labeldesc 64 { 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 /* list of labels or gotos */ 72 typedef struct Labellist 73 { 74 Labeldesc *arr; /* array */ 75 int n; /* number of entries in use */ 76 int size; /* array size */ 77 } Labellist; 78 79 /* dynamic structures used by the parser */ 80 typedef struct Dyndata 81 { 82 struct 83 { /* list of active local variables */ 84 Vardesc *arr; 85 int n; 86 int size; 87 } actvar; 88 Labellist gt; /* list of pending gotos */ 89 Labellist label; /* list of active labels */ 90 } Dyndata; 91 92 /* control of blocks */ 93 struct BlockCnt; /* defined in lparser.c */ 94 95 /* state needed to generate code for a given function */ 96 typedef struct FuncState 97 { 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 LUAI_FUNC Closure *luaY_parser(lua_State *L, ZIO *z, Mbuffer *buff, 116 Dyndata *dyd, const char *name, int firstchar); 117 118 #endif 119