module/lua/lparser.h

   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 */