src/lobject.h

   1 /*
   2 ** $Id: lobject.h,v 1.82 2000/10/30 17:49:19 roberto Exp $
   3 ** Type definitions for Lua objects
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7 #ifndef lobject_h
   8 #define lobject_h
   9
  10
  11 #include "llimits.h"
  12 #include "lua.h"
  13
  14
  15 #ifdef LUA_DEBUG
  16 #undef NDEBUG
  17 #include <assert.h>
  18 #define LUA_INTERNALERROR(s)    assert(((void)s,0))
  19 #define LUA_ASSERT(c,s)         assert(((void)s,(c)))
  20 #else
  21 #define LUA_INTERNALERROR(s)    /* empty */
  22 #define LUA_ASSERT(c,s)         /* empty */
  23 #endif
  24
  25
  26 #ifdef LUA_DEBUG
  27 /* to avoid warnings, and make sure value is really unused */
  28 #define UNUSED(x)       (x=0, (void)(x))
  29 #else
  30 #define UNUSED(x)       ((void)(x))     /* to avoid warnings */
  31 #endif
  32
  33
  34 /* mark for closures active in the stack */
  35 #define LUA_TMARK       6
  36
  37
  38 /* tags for values visible from Lua == first user-created tag */
  39 #define NUM_TAGS        6
  40
  41
  42 /* check whether `t' is a mark */
  43 #define is_T_MARK(t)    ((t) == LUA_TMARK)
  44
  45
  46 typedef union {
  47   struct TString *ts;   /* LUA_TSTRING, LUA_TUSERDATA */
  48   struct Closure *cl;   /* LUA_TFUNCTION */
  49   struct Hash *a;       /* LUA_TTABLE */
  50   struct CallInfo *i;   /* LUA_TLMARK */
  51   Number n;             /* LUA_TNUMBER */
  52 } Value;
  53
  54
  55 /* Macros to access values */
  56 #define ttype(o)        ((o)->ttype)
  57 #define nvalue(o)       ((o)->value.n)
  58 #define tsvalue(o)      ((o)->value.ts)
  59 #define clvalue(o)      ((o)->value.cl)
  60 #define hvalue(o)       ((o)->value.a)
  61 #define infovalue(o)    ((o)->value.i)
  62 #define svalue(o)       (tsvalue(o)->str)
  63
  64
  65 typedef struct lua_TObject {
  66   int ttype;
  67   Value value;
  68 } TObject;
  69
  70
  71 /*
  72 ** String headers for string table
  73 */
  74
  75 /*
  76 ** most `malloc' libraries allocate memory in blocks of 8 bytes. TSPACK
  77 ** tries to make sizeof(TString) a multiple of this granularity, to reduce
  78 ** waste of space.
  79 */
  80 #define TSPACK  ((int)sizeof(int))
  81
  82 typedef struct TString {
  83   union {
  84     struct {  /* for strings */
  85       unsigned long hash;
  86       int constindex;  /* hint to reuse constants */
  87     } s;
  88     struct {  /* for userdata */
  89       int tag;
  90       void *value;
  91     } d;
  92   } u;
  93   size_t len;
  94   struct TString *nexthash;  /* chain for hash table */
  95   int marked;
  96   char str[TSPACK];   /* variable length string!! must be the last field! */
  97 } TString;
  98
  99
 100 /*
 101 ** Function Prototypes
 102 */
 103 typedef struct Proto {
 104   Number *knum;  /* Number numbers used by the function */
 105   int nknum;  /* size of `knum' */
 106   struct TString **kstr;  /* strings used by the function */
 107   int nkstr;  /* size of `kstr' */
 108   struct Proto **kproto;  /* functions defined inside the function */
 109   int nkproto;  /* size of `kproto' */
 110   Instruction *code;
 111   int ncode;  /* size of `code'; when 0 means an incomplete `Proto' */
 112   short numparams;
 113   short is_vararg;
 114   short maxstacksize;
 115   short marked;
 116   struct Proto *next;
 117   /* debug information */
 118   int *lineinfo;  /* map from opcodes to source lines */
 119   int nlineinfo;  /* size of `lineinfo' */
 120   int nlocvars;
 121   struct LocVar *locvars;  /* information about local variables */
 122   int lineDefined;
 123   TString  *source;
 124 } Proto;
 125
 126
 127 typedef struct LocVar {
 128   TString *varname;
 129   int startpc;  /* first point where variable is active */
 130   int endpc;    /* first point where variable is dead */
 131 } LocVar;
 132
 133
 134 /*
 135 ** Closures
 136 */
 137 typedef struct Closure {
 138   union {
 139     lua_CFunction c;  /* C functions */
 140     struct Proto *l;  /* Lua functions */
 141   } f;
 142   struct Closure *next;
 143   struct Closure *mark;  /* marked closures (point to itself when not marked) */
 144   short isC;  /* 0 for Lua functions, 1 for C functions */
 145   short nupvalues;
 146   TObject upvalue[1];
 147 } Closure;
 148
 149
 150 #define iscfunction(o)  (ttype(o) == LUA_TFUNCTION && clvalue(o)->isC)
 151
 152
 153 typedef struct Node {
 154   TObject key;
 155   TObject val;
 156   struct Node *next;  /* for chaining */
 157 } Node;
 158
 159 typedef struct Hash {
 160   Node *node;
 161   int htag;
 162   int size;
 163   Node *firstfree;  /* this position is free; all positions after it are full */
 164   struct Hash *next;
 165   struct Hash *mark;  /* marked tables (point to itself when not marked) */
 166 } Hash;
 167
 168
 169 /* unmarked tables and closures are represented by pointing `mark' to
 170 ** themselves
 171 */
 172 #define ismarked(x)     ((x)->mark != (x))
 173
 174
 175 /*
 176 ** informations about a call (for debugging)
 177 */
 178 typedef struct CallInfo {
 179   struct Closure *func;  /* function being called */
 180   const Instruction **pc;  /* current pc of called function */
 181   int lastpc;  /* last pc traced */
 182   int line;  /* current line */
 183   int refi;  /* current index in `lineinfo' */
 184 } CallInfo;
 185
 186
 187 extern const TObject luaO_nilobject;
 188 extern const char *const luaO_typenames[];
 189
 190
 191 #define luaO_typename(o)        (luaO_typenames[ttype(o)])
 192
 193
 194 lint32 luaO_power2 (lint32 n);
 195 char *luaO_openspace (lua_State *L, size_t n);
 196
 197 int luaO_equalObj (const TObject *t1, const TObject *t2);
 198 int luaO_str2d (const char *s, Number *result);
 199
 200 void luaO_verror (lua_State *L, const char *fmt, ...);
 201 void luaO_chunkid (char *out, const char *source, int len);
 202
 203
 204 #endif