12.2.2.1.20. LOBJECT

12.2.2.1.20.1. lobject.h

/*
** $Id: lobject.h $
** Type definitions for Lua objects
** See Copyright Notice in lua.h
*/


#ifndef lobject_h
#define lobject_h


#include <stdarg.h>


#include "llimits.h"
#include "lua.h"

#include "_native_lua_config.h"  /* native Lua */


/*
** Extra types for collectable non-values
*/
#define LUA_TUPVAL	LUA_NUMTYPES  /* upvalues */
#define LUA_TPROTO	(LUA_NUMTYPES+1)  /* function prototypes */


/*
** number of all possible types (including LUA_TNONE)
*/
#define LUA_TOTALTYPES		(LUA_TPROTO + 2)


/*
** tags for Tagged Values have the following use of bits:
** bits 0-3: actual tag (a LUA_T* constant)
** bits 4-5: variant bits
** bit 6: whether value is collectable
*/

/* add variant bits to a type */
#define makevariant(t,v)	((t) | ((v) << 4))



/*
** Union of all Lua values
*/
typedef union Value {
  struct GCObject *gc;    /* collectable objects */
  void *p;         /* light userdata */
  lua_CFunction f; /* light C functions */
  lua_Integer i;   /* integer numbers */
  lua_Number n;    /* float numbers */
} Value;


/*
** Tagged Values. This is the basic representation of values in Lua:
** an actual value plus a tag with its type.
*/

#define TValuefields	Value value_; lu_byte tt_

typedef struct TValue {
  TValuefields;
} TValue;


#define val_(o)		((o)->value_)
#define valraw(o)	(&val_(o))


/* raw type tag of a TValue */
#define rawtt(o)	((o)->tt_)

/* tag with no variants (bits 0-3) */
#define novariant(t)	((t) & 0x0F)

/* type tag of a TValue (bits 0-3 for tags + variant bits 4-5) */
#define withvariant(t)	((t) & 0x3F)
#define ttypetag(o)	withvariant(rawtt(o))

/* type of a TValue */
#define ttype(o)	(novariant(rawtt(o)))


/* Macros to test type */
#define checktag(o,t)		(rawtt(o) == (t))
#define checktype(o,t)		(ttype(o) == (t))


/* Macros for internal tests */

/* collectable object has the same tag as the original value */
#define righttt(obj)		(ttypetag(obj) == gcvalue(obj)->tt)

/*
** Any value being manipulated by the program either is non
** collectable, or the collectable object has the right tag
** and it is not dead.
*/
#define checkliveness(L,obj) \
	((void)L, lua_longassert(!iscollectable(obj) || \
		(righttt(obj) && (L == NULL || !isdead(G(L),gcvalue(obj))))))


/* Macros to set values */

/* set a value's tag */
#define settt_(o,t)	((o)->tt_=(t))


/* main macro to copy values (from 'obj1' to 'obj2') */
#define setobj(L,obj1,obj2) \
	{ TValue *io1=(obj1); const TValue *io2=(obj2); \
          io1->value_ = io2->value_; settt_(io1, io2->tt_); \
	  checkliveness(L,io1); lua_assert(!isnonstrictnil(io1)); }

/*
** Different types of assignments, according to source and destination.
** (They are mostly equal now, but may be different in the future.)
*/

/* from stack to stack */
#define setobjs2s(L,o1,o2)	setobj(L,s2v(o1),s2v(o2))
/* to stack (not from same stack) */
#define setobj2s(L,o1,o2)	setobj(L,s2v(o1),o2)
/* from table to same table */
#define setobjt2t	setobj
/* to new object */
#define setobj2n	setobj
/* to table */
#define setobj2t	setobj


/*
** Entries in the Lua stack
*/
typedef union StackValue {
  TValue val;
} StackValue;


/* index to stack elements */
typedef StackValue *StkId;

/* convert a 'StackValue' to a 'TValue' */
#define s2v(o)	(&(o)->val)



/*
** {==================================================================
** Nil
** ===================================================================
*/

/* Standard nil */
#define LUA_VNIL	makevariant(LUA_TNIL, 0)

/* Empty slot (which might be different from a slot containing nil) */
#define LUA_VEMPTY	makevariant(LUA_TNIL, 1)

/* Value returned for a key not found in a table (absent key) */
#define LUA_VABSTKEY	makevariant(LUA_TNIL, 2)


/* macro to test for (any kind of) nil */
#define ttisnil(v)		checktype((v), LUA_TNIL)


/* macro to test for a standard nil */
#define ttisstrictnil(o)	checktag((o), LUA_VNIL)


#define setnilvalue(obj) settt_(obj, LUA_VNIL)


#define isabstkey(v)		checktag((v), LUA_VABSTKEY)


/*
** macro to detect non-standard nils (used only in assertions)
*/
#define isnonstrictnil(v)	(ttisnil(v) && !ttisstrictnil(v))


/*
** By default, entries with any kind of nil are considered empty.
** (In any definition, values associated with absent keys must also
** be accepted as empty.)
*/
#define isempty(v)		ttisnil(v)


/* macro defining a value corresponding to an absent key */
#define ABSTKEYCONSTANT		{NULL}, LUA_VABSTKEY


/* mark an entry as empty */
#define setempty(v)		settt_(v, LUA_VEMPTY)



/* }================================================================== */


/*
** {==================================================================
** Booleans
** ===================================================================
*/


#define LUA_VFALSE	makevariant(LUA_TBOOLEAN, 0)
#define LUA_VTRUE	makevariant(LUA_TBOOLEAN, 1)

#define ttisboolean(o)		checktype((o), LUA_TBOOLEAN)
#define ttisfalse(o)		checktag((o), LUA_VFALSE)
#define ttistrue(o)		checktag((o), LUA_VTRUE)


#define l_isfalse(o)	(ttisfalse(o) || ttisnil(o))


#define setbfvalue(obj)		settt_(obj, LUA_VFALSE)
#define setbtvalue(obj)		settt_(obj, LUA_VTRUE)

/* }================================================================== */


/*
** {==================================================================
** Threads
** ===================================================================
*/

#define LUA_VTHREAD		makevariant(LUA_TTHREAD, 0)

#define ttisthread(o)		checktag((o), ctb(LUA_VTHREAD))

#define thvalue(o)	check_exp(ttisthread(o), gco2th(val_(o).gc))

#define setthvalue(L,obj,x) \
  { TValue *io = (obj); lua_State *x_ = (x); \
    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VTHREAD)); \
    checkliveness(L,io); }

#define setthvalue2s(L,o,t)	setthvalue(L,s2v(o),t)

/* }================================================================== */


/*
** {==================================================================
** Collectable Objects
** ===================================================================
*/

/*
** Common Header for all collectable objects (in macro form, to be
** included in other objects)
*/
#define CommonHeader	struct GCObject *next; lu_byte tt; lu_byte marked


/* Common type for all collectable objects */
typedef struct GCObject {
  CommonHeader;
} GCObject;


/* Bit mark for collectable types */
#define BIT_ISCOLLECTABLE	(1 << 6)

#define iscollectable(o)	(rawtt(o) & BIT_ISCOLLECTABLE)

/* mark a tag as collectable */
#define ctb(t)			((t) | BIT_ISCOLLECTABLE)

#define gcvalue(o)	check_exp(iscollectable(o), val_(o).gc)

#define gcvalueraw(v)	((v).gc)

#define setgcovalue(L,obj,x) \
  { TValue *io = (obj); GCObject *i_g=(x); \
    val_(io).gc = i_g; settt_(io, ctb(i_g->tt)); }

/* }================================================================== */


/*
** {==================================================================
** Numbers
** ===================================================================
*/

/* Variant tags for numbers */
#define LUA_VNUMINT	makevariant(LUA_TNUMBER, 0)  /* integer numbers */
#define LUA_VNUMFLT	makevariant(LUA_TNUMBER, 1)  /* float numbers */

#define ttisnumber(o)		checktype((o), LUA_TNUMBER)
#define ttisfloat(o)		checktag((o), LUA_VNUMFLT)
#define ttisinteger(o)		checktag((o), LUA_VNUMINT)

#define nvalue(o)	check_exp(ttisnumber(o), \
	(ttisinteger(o) ? cast_num(ivalue(o)) : fltvalue(o)))
#define fltvalue(o)	check_exp(ttisfloat(o), val_(o).n)
#define ivalue(o)	check_exp(ttisinteger(o), val_(o).i)

#define fltvalueraw(v)	((v).n)
#define ivalueraw(v)	((v).i)

#define setfltvalue(obj,x) \
  { TValue *io=(obj); val_(io).n=(x); settt_(io, LUA_VNUMFLT); }

#define chgfltvalue(obj,x) \
  { TValue *io=(obj); lua_assert(ttisfloat(io)); val_(io).n=(x); }

#define setivalue(obj,x) \
  { TValue *io=(obj); val_(io).i=(x); settt_(io, LUA_VNUMINT); }

#define chgivalue(obj,x) \
  { TValue *io=(obj); lua_assert(ttisinteger(io)); val_(io).i=(x); }

/* }================================================================== */


/*
** {==================================================================
** Strings
** ===================================================================
*/

/* Variant tags for strings */
#define LUA_VSHRSTR	makevariant(LUA_TSTRING, 0)  /* short strings */
#define LUA_VLNGSTR	makevariant(LUA_TSTRING, 1)  /* long strings */

#define ttisstring(o)		checktype((o), LUA_TSTRING)
#define ttisshrstring(o)	checktag((o), ctb(LUA_VSHRSTR))
#define ttislngstring(o)	checktag((o), ctb(LUA_VLNGSTR))

#define tsvalueraw(v)	(gco2ts((v).gc))

#define tsvalue(o)	check_exp(ttisstring(o), gco2ts(val_(o).gc))

#define setsvalue(L,obj,x) \
  { TValue *io = (obj); TString *x_ = (x); \
    val_(io).gc = obj2gco(x_); settt_(io, ctb(x_->tt)); \
    checkliveness(L,io); }

/* set a string to the stack */
#define setsvalue2s(L,o,s)	setsvalue(L,s2v(o),s)

/* set a string to a new object */
#define setsvalue2n	setsvalue


/*
** Header for a string value.
*/
typedef struct TString {
  CommonHeader;
  lu_byte extra;  /* reserved words for short strings; "has hash" for longs */
  lu_byte shrlen;  /* length for short strings */
  unsigned int hash;
  union {
    size_t lnglen;  /* length for long strings */
    struct TString *hnext;  /* linked list for hash table */
  } u;
  char contents[1];
} TString;



/*
** Get the actual string (array of bytes) from a 'TString'.
*/
#define getstr(ts)  ((ts)->contents)


/* get the actual string (array of bytes) from a Lua value */
#define svalue(o)       getstr(tsvalue(o))

/* get string length from 'TString *s' */
#define tsslen(s)	((s)->tt == LUA_VSHRSTR ? (s)->shrlen : (s)->u.lnglen)

/* get string length from 'TValue *o' */
#define vslen(o)	tsslen(tsvalue(o))

/* }================================================================== */


/*
** {==================================================================
** Userdata
** ===================================================================
*/


/*
** Light userdata should be a variant of userdata, but for compatibility
** reasons they are also different types.
*/
#define LUA_VLIGHTUSERDATA	makevariant(LUA_TLIGHTUSERDATA, 0)

#define LUA_VUSERDATA		makevariant(LUA_TUSERDATA, 0)

#define ttislightuserdata(o)	checktag((o), LUA_VLIGHTUSERDATA)
#define ttisfulluserdata(o)	checktag((o), ctb(LUA_VUSERDATA))

#define pvalue(o)	check_exp(ttislightuserdata(o), val_(o).p)
#define uvalue(o)	check_exp(ttisfulluserdata(o), gco2u(val_(o).gc))

#define pvalueraw(v)	((v).p)

#define setpvalue(obj,x) \
  { TValue *io=(obj); val_(io).p=(x); settt_(io, LUA_VLIGHTUSERDATA); }

#define setuvalue(L,obj,x) \
  { TValue *io = (obj); Udata *x_ = (x); \
    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VUSERDATA)); \
    checkliveness(L,io); }


/* Ensures that addresses after this type are always fully aligned. */
typedef union UValue {
  TValue uv;
  LUAI_MAXALIGN;  /* ensures maximum alignment for udata bytes */
} UValue;


/*
** Header for userdata with user values;
** memory area follows the end of this structure.
*/
typedef struct Udata {
  CommonHeader;
  unsigned short nuvalue;  /* number of user values */
  size_t len;  /* number of bytes */
  struct Table *metatable;
  GCObject *gclist;
  UValue uv[1];  /* user values */
} Udata;


/*
** Header for userdata with no user values. These userdata do not need
** to be gray during GC, and therefore do not need a 'gclist' field.
** To simplify, the code always use 'Udata' for both kinds of userdata,
** making sure it never accesses 'gclist' on userdata with no user values.
** This structure here is used only to compute the correct size for
** this representation. (The 'bindata' field in its end ensures correct
** alignment for binary data following this header.)
*/
typedef struct Udata0 {
  CommonHeader;
  unsigned short nuvalue;  /* number of user values */
  size_t len;  /* number of bytes */
  struct Table *metatable;
  union {LUAI_MAXALIGN;} bindata;
} Udata0;


/* compute the offset of the memory area of a userdata */
#define udatamemoffset(nuv) \
	((nuv) == 0 ? offsetof(Udata0, bindata)  \
                    : offsetof(Udata, uv) + (sizeof(UValue) * (nuv)))

/* get the address of the memory block inside 'Udata' */
#define getudatamem(u)	(cast_charp(u) + udatamemoffset((u)->nuvalue))

/* compute the size of a userdata */
#define sizeudata(nuv,nb)	(udatamemoffset(nuv) + (nb))

/* }================================================================== */


/*
** {==================================================================
** Prototypes
** ===================================================================
*/

#define LUA_VPROTO	makevariant(LUA_TPROTO, 0)


/*
** Description of an upvalue for function prototypes
*/
typedef struct Upvaldesc {
  TString *name;  /* upvalue name (for debug information) */
  lu_byte instack;  /* whether it is in stack (register) */
  lu_byte idx;  /* index of upvalue (in stack or in outer function's list) */
  lu_byte kind;  /* kind of corresponding variable */
} Upvaldesc;


/*
** Description of a local variable for function prototypes
** (used for debug information)
*/
typedef struct LocVar {
  TString *varname;
  int startpc;  /* first point where variable is active */
  int endpc;    /* first point where variable is dead */
} LocVar;


/*
** Associates the absolute line source for a given instruction ('pc').
** The array 'lineinfo' gives, for each instruction, the difference in
** lines from the previous instruction. When that difference does not
** fit into a byte, Lua saves the absolute line for that instruction.
** (Lua also saves the absolute line periodically, to speed up the
** computation of a line number: we can use binary search in the
** absolute-line array, but we must traverse the 'lineinfo' array
** linearly to compute a line.)
*/
typedef struct AbsLineInfo {
  int pc;
  int line;
} AbsLineInfo;

/*
** Function Prototypes
*/
typedef struct Proto {
  CommonHeader;
  lu_byte numparams;  /* number of fixed (named) parameters */
  lu_byte is_vararg;
  lu_byte maxstacksize;  /* number of registers needed by this function */
  int sizeupvalues;  /* size of 'upvalues' */
  int sizek;  /* size of 'k' */
  int sizecode;
  int sizelineinfo;
  int sizep;  /* size of 'p' */
  int sizelocvars;
  int sizeabslineinfo;  /* size of 'abslineinfo' */
  int linedefined;  /* debug information  */
  int lastlinedefined;  /* debug information  */
  TValue *k;  /* constants used by the function */
  Instruction *code;  /* opcodes */
  struct Proto **p;  /* functions defined inside the function */
  Upvaldesc *upvalues;  /* upvalue information */
  ls_byte *lineinfo;  /* information about source lines (debug information) */
  AbsLineInfo *abslineinfo;  /* idem */
  LocVar *locvars;  /* information about local variables (debug information) */
  TString  *source;  /* used for debug information */
  GCObject *gclist;
} Proto;

/* }================================================================== */


/*
** {==================================================================
** Closures
** ===================================================================
*/

#define LUA_VUPVAL	makevariant(LUA_TUPVAL, 0)


/* Variant tags for functions */
#define LUA_VLCL	makevariant(LUA_TFUNCTION, 0)  /* Lua closure */
#define LUA_VLCF	makevariant(LUA_TFUNCTION, 1)  /* light C function */
#define LUA_VCCL	makevariant(LUA_TFUNCTION, 2)  /* C closure */

#define ttisfunction(o)		checktype(o, LUA_TFUNCTION)
#define ttisclosure(o)		((rawtt(o) & 0x1F) == LUA_VLCL)
#define ttisLclosure(o)		checktag((o), ctb(LUA_VLCL))
#define ttislcf(o)		checktag((o), LUA_VLCF)
#define ttisCclosure(o)		checktag((o), ctb(LUA_VCCL))

#define isLfunction(o)	ttisLclosure(o)

#define clvalue(o)	check_exp(ttisclosure(o), gco2cl(val_(o).gc))
#define clLvalue(o)	check_exp(ttisLclosure(o), gco2lcl(val_(o).gc))
#define fvalue(o)	check_exp(ttislcf(o), val_(o).f)
#define clCvalue(o)	check_exp(ttisCclosure(o), gco2ccl(val_(o).gc))

#define fvalueraw(v)	((v).f)

#define setclLvalue(L,obj,x) \
  { TValue *io = (obj); LClosure *x_ = (x); \
    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VLCL)); \
    checkliveness(L,io); }

#define setclLvalue2s(L,o,cl)	setclLvalue(L,s2v(o),cl)

#define setfvalue(obj,x) \
  { TValue *io=(obj); val_(io).f=(x); settt_(io, LUA_VLCF); }

#define setclCvalue(L,obj,x) \
  { TValue *io = (obj); CClosure *x_ = (x); \
    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VCCL)); \
    checkliveness(L,io); }


/*
** Upvalues for Lua closures
*/
typedef struct UpVal {
  CommonHeader;
  lu_byte tbc;  /* true if it represents a to-be-closed variable */
  TValue *v;  /* points to stack or to its own value */
  union {
    struct {  /* (when open) */
      struct UpVal *next;  /* linked list */
      struct UpVal **previous;
    } open;
    TValue value;  /* the value (when closed) */
  } u;
} UpVal;



#define ClosureHeader \
	CommonHeader; lu_byte nupvalues; GCObject *gclist

typedef struct CClosure {
  ClosureHeader;
  lua_CFunction f;
  TValue upvalue[1];  /* list of upvalues */
} CClosure;


typedef struct LClosure {
  ClosureHeader;
  struct Proto *p;
  UpVal *upvals[1];  /* list of upvalues */
} LClosure;


typedef union Closure {
  CClosure c;
  LClosure l;
} Closure;


#define getproto(o)	(clLvalue(o)->p)

/* }================================================================== */


/*
** {==================================================================
** Tables
** ===================================================================
*/

#define LUA_VTABLE	makevariant(LUA_TTABLE, 0)

#define ttistable(o)		checktag((o), ctb(LUA_VTABLE))

#define hvalue(o)	check_exp(ttistable(o), gco2t(val_(o).gc))

#define sethvalue(L,obj,x) \
  { TValue *io = (obj); Table *x_ = (x); \
    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VTABLE)); \
    checkliveness(L,io); }

#define sethvalue2s(L,o,h)	sethvalue(L,s2v(o),h)


/*
** Nodes for Hash tables: A pack of two TValue's (key-value pairs)
** plus a 'next' field to link colliding entries. The distribution
** of the key's fields ('key_tt' and 'key_val') not forming a proper
** 'TValue' allows for a smaller size for 'Node' both in 4-byte
** and 8-byte alignments.
*/
typedef union Node {
  struct NodeKey {
    TValuefields;  /* fields for value */
    lu_byte key_tt;  /* key type */
    int next;  /* for chaining */
    Value key_val;  /* key value */
  } u;
  TValue i_val;  /* direct access to node's value as a proper 'TValue' */
} Node;


/* copy a value into a key */
#define setnodekey(L,node,obj) \
	{ Node *n_=(node); const TValue *io_=(obj); \
	  n_->u.key_val = io_->value_; n_->u.key_tt = io_->tt_; \
	  checkliveness(L,io_); }


/* copy a value from a key */
#define getnodekey(L,obj,node) \
	{ TValue *io_=(obj); const Node *n_=(node); \
	  io_->value_ = n_->u.key_val; io_->tt_ = n_->u.key_tt; \
	  checkliveness(L,io_); }


/*
** About 'alimit': if 'isrealasize(t)' is true, then 'alimit' is the
** real size of 'array'. Otherwise, the real size of 'array' is the
** smallest power of two not smaller than 'alimit' (or zero iff 'alimit'
** is zero); 'alimit' is then used as a hint for #t.
*/

#define BITRAS		(1 << 7)
#define isrealasize(t)		(!((t)->marked & BITRAS))
#define setrealasize(t)		((t)->marked &= cast_byte(~BITRAS))
#define setnorealasize(t)	((t)->marked |= BITRAS)


typedef struct Table {
  CommonHeader;
  lu_byte flags;  /* 1<<p means tagmethod(p) is not present */
  lu_byte lsizenode;  /* log2 of size of 'node' array */
  unsigned int alimit;  /* "limit" of 'array' array */
  TValue *array;  /* array part */
  Node *node;
  Node *lastfree;  /* any free position is before this position */
  struct Table *metatable;
  GCObject *gclist;
} Table;


/*
** Macros to manipulate keys inserted in nodes
*/
#define keytt(node)		((node)->u.key_tt)
#define keyval(node)		((node)->u.key_val)

#define keyisnil(node)		(keytt(node) == LUA_TNIL)
#define keyisinteger(node)	(keytt(node) == LUA_VNUMINT)
#define keyival(node)		(keyval(node).i)
#define keyisshrstr(node)	(keytt(node) == ctb(LUA_VSHRSTR))
#define keystrval(node)		(gco2ts(keyval(node).gc))

#define setnilkey(node)		(keytt(node) = LUA_TNIL)

#define keyiscollectable(n)	(keytt(n) & BIT_ISCOLLECTABLE)

#define gckey(n)	(keyval(n).gc)
#define gckeyN(n)	(keyiscollectable(n) ? gckey(n) : NULL)


/*
** Use a "nil table" to mark dead keys in a table. Those keys serve
** to keep space for removed entries, which may still be part of
** chains. Note that the 'keytt' does not have the BIT_ISCOLLECTABLE
** set, so these values are considered not collectable and are different
** from any valid value.
*/
#define setdeadkey(n)	(keytt(n) = LUA_TTABLE, gckey(n) = NULL)

/* }================================================================== */



/*
** 'module' operation for hashing (size is always a power of 2)
*/
#define lmod(s,size) \
	(check_exp((size&(size-1))==0, (cast_int((s) & ((size)-1)))))


#define twoto(x)	(1<<(x))
#define sizenode(t)	(twoto((t)->lsizenode))


/* size of buffer for 'luaO_utf8esc' function */
#define UTF8BUFFSZ	8

LUAI_FUNC int luaO_utf8esc (char *buff, unsigned long x);
LUAI_FUNC int luaO_ceillog2 (unsigned int x);
LUAI_FUNC int luaO_rawarith (lua_State *L, int op, const TValue *p1,
                             const TValue *p2, TValue *res);
LUAI_FUNC void luaO_arith (lua_State *L, int op, const TValue *p1,
                           const TValue *p2, StkId res);
LUAI_FUNC size_t luaO_str2num (const char *s, TValue *o);
LUAI_FUNC int luaO_hexavalue (int c);
LUAI_FUNC void luaO_tostring (lua_State *L, TValue *obj);
LUAI_FUNC const char *luaO_pushvfstring (lua_State *L, const char *fmt,
                                                       va_list argp);
LUAI_FUNC const char *luaO_pushfstring (lua_State *L, const char *fmt, ...);
LUAI_FUNC void luaO_chunkid (char *out, const char *source, size_t srclen);


#endif

12.2.2.1.20.2. lobject.c

/*
** $Id: lobject.c $
** Some generic functions over Lua objects
** See Copyright Notice in lua.h
*/

#define lobject_c
#define LUA_CORE

#include "lprefix.h"


#include <locale.h>
#include <math.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "lua.h"

#include "lctype.h"
#include "ldebug.h"
#include "ldo.h"
#include "lmem.h"
#include "lobject.h"
#include "lstate.h"
#include "lstring.h"
#include "lvm.h"


/*
** Computes ceil(log2(x))
*/
int luaO_ceillog2 (unsigned int x) {
  static const lu_byte log_2[256] = {  /* log_2[i] = ceil(log2(i - 1)) */
    0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
    6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8
  };
  int l = 0;
  x--;
  while (x >= 256) { l += 8; x >>= 8; }
  return l + log_2[x];
}


static lua_Integer intarith (lua_State *L, int op, lua_Integer v1,
                                                   lua_Integer v2) {
  switch (op) {
    case LUA_OPADD: return intop(+, v1, v2);
    case LUA_OPSUB:return intop(-, v1, v2);
    case LUA_OPMUL:return intop(*, v1, v2);
    case LUA_OPMOD: return luaV_mod(L, v1, v2);
    case LUA_OPIDIV: return luaV_idiv(L, v1, v2);
    case LUA_OPBAND: return intop(&, v1, v2);
    case LUA_OPBOR: return intop(|, v1, v2);
    case LUA_OPBXOR: return intop(^, v1, v2);
    case LUA_OPSHL: return luaV_shiftl(v1, v2);
    case LUA_OPSHR: return luaV_shiftl(v1, -v2);
    case LUA_OPUNM: return intop(-, 0, v1);
    case LUA_OPBNOT: return intop(^, ~l_castS2U(0), v1);
    default: lua_assert(0); return 0;
  }
}


static lua_Number numarith (lua_State *L, int op, lua_Number v1,
                                                  lua_Number v2) {
  switch (op) {
    case LUA_OPADD: return luai_numadd(L, v1, v2);
    case LUA_OPSUB: return luai_numsub(L, v1, v2);
    case LUA_OPMUL: return luai_nummul(L, v1, v2);
    case LUA_OPDIV: return luai_numdiv(L, v1, v2);
    case LUA_OPPOW: return luai_numpow(L, v1, v2);
    case LUA_OPIDIV: return luai_numidiv(L, v1, v2);
    case LUA_OPUNM: return luai_numunm(L, v1);
    case LUA_OPMOD: return luaV_modf(L, v1, v2);
    default: lua_assert(0); return 0;
  }
}


int luaO_rawarith (lua_State *L, int op, const TValue *p1, const TValue *p2,
                   TValue *res) {
  switch (op) {
    case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR:
    case LUA_OPSHL: case LUA_OPSHR:
    case LUA_OPBNOT: {  /* operate only on integers */
      lua_Integer i1; lua_Integer i2;
      if (tointegerns(p1, &i1) && tointegerns(p2, &i2)) {
        setivalue(res, intarith(L, op, i1, i2));
        return 1;
      }
      else return 0;  /* fail */
    }
    case LUA_OPDIV: case LUA_OPPOW: {  /* operate only on floats */
      lua_Number n1; lua_Number n2;
      if (tonumberns(p1, n1) && tonumberns(p2, n2)) {
        setfltvalue(res, numarith(L, op, n1, n2));
        return 1;
      }
      else return 0;  /* fail */
    }
    default: {  /* other operations */
      lua_Number n1; lua_Number n2;
      if (ttisinteger(p1) && ttisinteger(p2)) {
        setivalue(res, intarith(L, op, ivalue(p1), ivalue(p2)));
        return 1;
      }
      else if (tonumberns(p1, n1) && tonumberns(p2, n2)) {
        setfltvalue(res, numarith(L, op, n1, n2));
        return 1;
      }
      else return 0;  /* fail */
    }
  }
}


void luaO_arith (lua_State *L, int op, const TValue *p1, const TValue *p2,
                 StkId res) {
  if (!luaO_rawarith(L, op, p1, p2, s2v(res))) {
    /* could not perform raw operation; try metamethod */
    luaT_trybinTM(L, p1, p2, res, cast(TMS, (op - LUA_OPADD) + TM_ADD));
  }
}


int luaO_hexavalue (int c) {
  if (lisdigit(c)) return c - '0';
  else return (ltolower(c) - 'a') + 10;
}


static int isneg (const char **s) {
  if (**s == '-') { (*s)++; return 1; }
  else if (**s == '+') (*s)++;
  return 0;
}



/*
** {==================================================================
** Lua's implementation for 'lua_strx2number'
** ===================================================================
*/

#if !defined(lua_strx2number)

/* maximum number of significant digits to read (to avoid overflows
   even with single floats) */
#define MAXSIGDIG	30

/*
** convert a hexadecimal numeric string to a number, following
** C99 specification for 'strtod'
*/
static lua_Number lua_strx2number (const char *s, char **endptr) {
  int dot = lua_getlocaledecpoint();
  lua_Number r = 0.0;  /* result (accumulator) */
  int sigdig = 0;  /* number of significant digits */
  int nosigdig = 0;  /* number of non-significant digits */
  int e = 0;  /* exponent correction */
  int neg;  /* 1 if number is negative */
  int hasdot = 0;  /* true after seen a dot */
  *endptr = cast_charp(s);  /* nothing is valid yet */
  while (lisspace(cast_uchar(*s))) s++;  /* skip initial spaces */
  neg = isneg(&s);  /* check sign */
  if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X')))  /* check '0x' */
    return 0.0;  /* invalid format (no '0x') */
  for (s += 2; ; s++) {  /* skip '0x' and read numeral */
    if (*s == dot) {
      if (hasdot) break;  /* second dot? stop loop */
      else hasdot = 1;
    }
    else if (lisxdigit(cast_uchar(*s))) {
      if (sigdig == 0 && *s == '0')  /* non-significant digit (zero)? */
        nosigdig++;
      else if (++sigdig <= MAXSIGDIG)  /* can read it without overflow? */
          r = (r * cast_num(16.0)) + luaO_hexavalue(*s);
      else e++; /* too many digits; ignore, but still count for exponent */
      if (hasdot) e--;  /* decimal digit? correct exponent */
    }
    else break;  /* neither a dot nor a digit */
  }
  if (nosigdig + sigdig == 0)  /* no digits? */
    return 0.0;  /* invalid format */
  *endptr = cast_charp(s);  /* valid up to here */
  e *= 4;  /* each digit multiplies/divides value by 2^4 */
  if (*s == 'p' || *s == 'P') {  /* exponent part? */
    int exp1 = 0;  /* exponent value */
    int neg1;  /* exponent sign */
    s++;  /* skip 'p' */
    neg1 = isneg(&s);  /* sign */
    if (!lisdigit(cast_uchar(*s)))
      return 0.0;  /* invalid; must have at least one digit */
    while (lisdigit(cast_uchar(*s)))  /* read exponent */
      exp1 = exp1 * 10 + *(s++) - '0';
    if (neg1) exp1 = -exp1;
    e += exp1;
    *endptr = cast_charp(s);  /* valid up to here */
  }
  if (neg) r = -r;
  return l_mathop(ldexp)(r, e);
}

#endif
/* }====================================================== */


/* maximum length of a numeral */
#if !defined (L_MAXLENNUM)
#define L_MAXLENNUM	200
#endif

static const char *l_str2dloc (const char *s, lua_Number *result, int mode) {
  char *endptr;
  *result = (mode == 'x') ? lua_strx2number(s, &endptr)  /* try to convert */
                          : lua_str2number(s, &endptr);
  if (endptr == s) return NULL;  /* nothing recognized? */
  while (lisspace(cast_uchar(*endptr))) endptr++;  /* skip trailing spaces */
  return (*endptr == '\0') ? endptr : NULL;  /* OK if no trailing characters */
}


/*
** Convert string 's' to a Lua number (put in 'result'). Return NULL
** on fail or the address of the ending '\0' on success.
** 'pmode' points to (and 'mode' contains) special things in the string:
** - 'x'/'X' means a hexadecimal numeral
** - 'n'/'N' means 'inf' or 'nan' (which should be rejected)
** - '.' just optimizes the search for the common case (nothing special)
** This function accepts both the current locale or a dot as the radix
** mark. If the conversion fails, it may mean number has a dot but
** locale accepts something else. In that case, the code copies 's'
** to a buffer (because 's' is read-only), changes the dot to the
** current locale radix mark, and tries to convert again.
*/
static const char *l_str2d (const char *s, lua_Number *result) {
  const char *endptr;
  const char *pmode = strpbrk(s, ".xXnN");
  int mode = pmode ? ltolower(cast_uchar(*pmode)) : 0;
  if (mode == 'n')  /* reject 'inf' and 'nan' */
    return NULL;
  endptr = l_str2dloc(s, result, mode);  /* try to convert */
  if (endptr == NULL) {  /* failed? may be a different locale */
    char buff[L_MAXLENNUM + 1];
    const char *pdot = strchr(s, '.');
    if (strlen(s) > L_MAXLENNUM || pdot == NULL)
      return NULL;  /* string too long or no dot; fail */
    strcpy(buff, s);  /* copy string to buffer */
    buff[pdot - s] = lua_getlocaledecpoint();  /* correct decimal point */
    endptr = l_str2dloc(buff, result, mode);  /* try again */
    if (endptr != NULL)
      endptr = s + (endptr - buff);  /* make relative to 's' */
  }
  return endptr;
}


#define MAXBY10		cast(lua_Unsigned, LUA_MAXINTEGER / 10)
#define MAXLASTD	cast_int(LUA_MAXINTEGER % 10)

static const char *l_str2int (const char *s, lua_Integer *result) {
  lua_Unsigned a = 0;
  int empty = 1;
  int neg;
  while (lisspace(cast_uchar(*s))) s++;  /* skip initial spaces */
  neg = isneg(&s);
  if (s[0] == '0' &&
      (s[1] == 'x' || s[1] == 'X')) {  /* hex? */
    s += 2;  /* skip '0x' */
    for (; lisxdigit(cast_uchar(*s)); s++) {
      a = a * 16 + luaO_hexavalue(*s);
      empty = 0;
    }
  }
  else {  /* decimal */
    for (; lisdigit(cast_uchar(*s)); s++) {
      int d = *s - '0';
      if (a >= MAXBY10 && (a > MAXBY10 || d > MAXLASTD + neg))  /* overflow? */
        return NULL;  /* do not accept it (as integer) */
      a = a * 10 + d;
      empty = 0;
    }
  }
  while (lisspace(cast_uchar(*s))) s++;  /* skip trailing spaces */
  if (empty || *s != '\0') return NULL;  /* something wrong in the numeral */
  else {
    *result = l_castU2S((neg) ? 0u - a : a);
    return s;
  }
}


size_t luaO_str2num (const char *s, TValue *o) {
  lua_Integer i; lua_Number n;
  const char *e;
  if ((e = l_str2int(s, &i)) != NULL) {  /* try as an integer */
    setivalue(o, i);
  }
  else if ((e = l_str2d(s, &n)) != NULL) {  /* else try as a float */
    setfltvalue(o, n);
  }
  else
    return 0;  /* conversion failed */
  return (e - s) + 1;  /* success; return string size */
}


int luaO_utf8esc (char *buff, unsigned long x) {
  int n = 1;  /* number of bytes put in buffer (backwards) */
  lua_assert(x <= 0x7FFFFFFFu);
  if (x < 0x80)  /* ascii? */
    buff[UTF8BUFFSZ - 1] = cast_char(x);
  else {  /* need continuation bytes */
    unsigned int mfb = 0x3f;  /* maximum that fits in first byte */
    do {  /* add continuation bytes */
      buff[UTF8BUFFSZ - (n++)] = cast_char(0x80 | (x & 0x3f));
      x >>= 6;  /* remove added bits */
      mfb >>= 1;  /* now there is one less bit available in first byte */
    } while (x > mfb);  /* still needs continuation byte? */
    buff[UTF8BUFFSZ - n] = cast_char((~mfb << 1) | x);  /* add first byte */
  }
  return n;
}


/* maximum length of the conversion of a number to a string */
#define MAXNUMBER2STR	50


/*
** Convert a number object to a string, adding it to a buffer
*/
static int tostringbuff (TValue *obj, char *buff) {
  int len;
  lua_assert(ttisnumber(obj));
  if (ttisinteger(obj))
    len = lua_integer2str(buff, MAXNUMBER2STR, ivalue(obj));
  else {
    len = lua_number2str(buff, MAXNUMBER2STR, fltvalue(obj));
    if (buff[strspn(buff, "-0123456789")] == '\0') {  /* looks like an int? */
      buff[len++] = lua_getlocaledecpoint();
      buff[len++] = '0';  /* adds '.0' to result */
    }
  }
  return len;
}


/*
** Convert a number object to a Lua string, replacing the value at 'obj'
*/
void luaO_tostring (lua_State *L, TValue *obj) {
  char buff[MAXNUMBER2STR];
  int len = tostringbuff(obj, buff);
  setsvalue(L, obj, luaS_newlstr(L, buff, len));
}




/*
** {==================================================================
** 'luaO_pushvfstring'
** ===================================================================
*/

/* size for buffer space used by 'luaO_pushvfstring' */
#define BUFVFS		400

/* buffer used by 'luaO_pushvfstring' */
typedef struct BuffFS {
  lua_State *L;
  int pushed;  /* number of string pieces already on the stack */
  int blen;  /* length of partial string in 'space' */
  char space[BUFVFS];  /* holds last part of the result */
} BuffFS;


/*
** Push given string to the stack, as part of the buffer. If the stack
** is almost full, join all partial strings in the stack into one.
*/
static void pushstr (BuffFS *buff, const char *str, size_t l) {
  lua_State *L = buff->L;
  setsvalue2s(L, L->top, luaS_newlstr(L, str, l));
  L->top++;  /* may use one extra slot */
  buff->pushed++;
  if (buff->pushed > 1 && L->top + 1 >= L->stack_last) {
    luaV_concat(L, buff->pushed);  /* join all partial results into one */
    buff->pushed = 1;
  }
}


/*
** empty the buffer space into the stack
*/
static void clearbuff (BuffFS *buff) {
  pushstr(buff, buff->space, buff->blen);  /* push buffer contents */
  buff->blen = 0;  /* space now is empty */
}


/*
** Get a space of size 'sz' in the buffer. If buffer has not enough
** space, empty it. 'sz' must fit in an empty buffer.
*/
static char *getbuff (BuffFS *buff, int sz) {
  lua_assert(buff->blen <= BUFVFS); lua_assert(sz <= BUFVFS);
  if (sz > BUFVFS - buff->blen)  /* not enough space? */
    clearbuff(buff);
  return buff->space + buff->blen;
}


#define addsize(b,sz)	((b)->blen += (sz))


/*
** Add 'str' to the buffer. If string is larger than the buffer space,
** push the string directly to the stack.
*/
static void addstr2buff (BuffFS *buff, const char *str, size_t slen) {
  if (slen <= BUFVFS) {  /* does string fit into buffer? */
    char *bf = getbuff(buff, cast_int(slen));
    memcpy(bf, str, slen);  /* add string to buffer */
    addsize(buff, cast_int(slen));
  }
  else {  /* string larger than buffer */
    clearbuff(buff);  /* string comes after buffer's content */
    pushstr(buff, str, slen);  /* push string */
  }
}


/*
** Add a number to the buffer.
*/
static void addnum2buff (BuffFS *buff, TValue *num) {
  char *numbuff = getbuff(buff, MAXNUMBER2STR);
  int len = tostringbuff(num, numbuff);  /* format number into 'numbuff' */
  addsize(buff, len);
}


/*
** this function handles only '%d', '%c', '%f', '%p', '%s', and '%%'
   conventional formats, plus Lua-specific '%I' and '%U'
*/
const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
  BuffFS buff;  /* holds last part of the result */
  const char *e;  /* points to next '%' */
  buff.pushed = buff.blen = 0;
  buff.L = L;
  while ((e = strchr(fmt, '%')) != NULL) {
    addstr2buff(&buff, fmt, e - fmt);  /* add 'fmt' up to '%' */
    switch (*(e + 1)) {  /* conversion specifier */
      case 's': {  /* zero-terminated string */
        const char *s = va_arg(argp, char *);
        if (s == NULL) s = "(null)";
        addstr2buff(&buff, s, strlen(s));
        break;
      }
      case 'c': {  /* an 'int' as a character */
        char c = cast_uchar(va_arg(argp, int));
        addstr2buff(&buff, &c, sizeof(char));
        break;
      }
      case 'd': {  /* an 'int' */
        TValue num;
        setivalue(&num, va_arg(argp, int));
        addnum2buff(&buff, &num);
        break;
      }
      case 'I': {  /* a 'lua_Integer' */
        TValue num;
        setivalue(&num, cast(lua_Integer, va_arg(argp, l_uacInt)));
        addnum2buff(&buff, &num);
        break;
      }
      case 'f': {  /* a 'lua_Number' */
        TValue num;
        setfltvalue(&num, cast_num(va_arg(argp, l_uacNumber)));
        addnum2buff(&buff, &num);
        break;
      }
      case 'p': {  /* a pointer */
        const int sz = 3 * sizeof(void*) + 8; /* enough space for '%p' */
        char *bf = getbuff(&buff, sz);
        void *p = va_arg(argp, void *);
        int len = lua_pointer2str(bf, sz, p);
        addsize(&buff, len);
        break;
      }
      case 'U': {  /* a 'long' as a UTF-8 sequence */
        char bf[UTF8BUFFSZ];
        int len = luaO_utf8esc(bf, va_arg(argp, long));
        addstr2buff(&buff, bf + UTF8BUFFSZ - len, len);
        break;
      }
      case '%': {
        addstr2buff(&buff, "%", 1);
        break;
      }
      default: {
        luaG_runerror(L, "invalid option '%%%c' to 'lua_pushfstring'",
                         *(e + 1));
      }
    }
    fmt = e + 2;  /* skip '%' and the specifier */
  }
  addstr2buff(&buff, fmt, strlen(fmt));  /* rest of 'fmt' */
  clearbuff(&buff);  /* empty buffer into the stack */
  if (buff.pushed > 1)
    luaV_concat(L, buff.pushed);  /* join all partial results */
  return svalue(s2v(L->top - 1));
}


const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
  const char *msg;
  va_list argp;
  va_start(argp, fmt);
  msg = luaO_pushvfstring(L, fmt, argp);
  va_end(argp);
  return msg;
}

/* }================================================================== */


#define RETS	"..."
#define PRE	"[string \""
#define POS	"\"]"

#define addstr(a,b,l)	( memcpy(a,b,(l) * sizeof(char)), a += (l) )

void luaO_chunkid (char *out, const char *source, size_t srclen) {
  size_t bufflen = LUA_IDSIZE;  /* free space in buffer */
  if (*source == '=') {  /* 'literal' source */
    if (srclen <= bufflen)  /* small enough? */
      memcpy(out, source + 1, srclen * sizeof(char));
    else {  /* truncate it */
      addstr(out, source + 1, bufflen - 1);
      *out = '\0';
    }
  }
  else if (*source == '@') {  /* file name */
    if (srclen <= bufflen)  /* small enough? */
      memcpy(out, source + 1, srclen * sizeof(char));
    else {  /* add '...' before rest of name */
      addstr(out, RETS, LL(RETS));
      bufflen -= LL(RETS);
      memcpy(out, source + 1 + srclen - bufflen, bufflen * sizeof(char));
    }
  }
  else {  /* string; format as [string "source"] */
    const char *nl = strchr(source, '\n');  /* find first new line (if any) */
    addstr(out, PRE, LL(PRE));  /* add prefix */
    bufflen -= LL(PRE RETS POS) + 1;  /* save space for prefix+suffix+'\0' */
    if (srclen < bufflen && nl == NULL) {  /* small one-line source? */
      addstr(out, source, srclen);  /* keep it */
    }
    else {
      if (nl != NULL) srclen = nl - source;  /* stop at first newline */
      if (srclen > bufflen) srclen = bufflen;
      addstr(out, source, srclen);
      addstr(out, RETS, LL(RETS));
    }
    memcpy(out, POS, (LL(POS) + 1) * sizeof(char));
  }
}