1 /* 2 ** $Id: lparser.h,v 1.74 2014/10/25 11:50:46 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 VKFLT, /* nval = numerical float value */ 26 VKINT, /* nval = numerical integer 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 VKFLT */ 51 lua_Integer ival; /* for VKINT */ 52 } u; 53 int t; /* patch list of 'exit when true' */ 54 int f; /* patch list of 'exit when false' */ 55 } expdesc; 56 57 58 /* description of active local variable */ 59 typedef struct Vardesc { 60 short idx; /* variable index in stack */ 61 } Vardesc; 62 63 64 /* description of pending goto statements and label statements */ 65 typedef struct Labeldesc { 66 TString *name; /* label identifier */ 67 int pc; /* position in code */ 68 int line; /* line where it appeared */ 69 lu_byte nactvar; /* local level where it appears in current block */ 70 } Labeldesc; 71 72 73 /* list of labels or gotos */ 74 typedef struct Labellist { 75 Labeldesc *arr; /* array */ 76 int n; /* number of entries in use */ 77 int size; /* array size */ 78 } Labellist; 79 80 81 /* dynamic structures used by the parser */ 82 typedef struct Dyndata { 83 struct { /* 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 93 /* control of blocks */ 94 struct BlockCnt; /* defined in lparser.c */ 95 96 97 /* state needed to generate code for a given function */ 98 typedef struct FuncState { 99 Proto *f; /* current function header */ 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 LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff, 117 Dyndata *dyd, const char *name, int firstchar); 118 119 120 #endif 121