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  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. /*
  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.