lua/lobject.h
Roberto Ierusalimschy 8047b2d03e Tables have a 'lastfree' information only when needed
Only tables with some minimum number of entries in their hash part
have a 'lastfree' field, kept in a header before the node vector.
2022-11-01 15:42:08 -03:00

816 lines
22 KiB
C

/*
** $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"
/*
** Extra types for collectable non-values
*/
#define LUA_TUPVAL LUA_NUMTYPES /* upvalues */
#define LUA_TPROTO (LUA_NUMTYPES+1) /* function prototypes */
#define LUA_TDEADKEY (LUA_NUMTYPES+2) /* removed keys in tables */
/*
** number of all possible types (including LUA_TNONE but excluding DEADKEY)
*/
#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 */
/* not used, but may avoid warnings for uninitialized value */
lu_byte ub;
} 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. The option 'L == NULL' allows other
** macros using this one to be used where L is not available.
*/
#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 'obj2' to 'obj1') */
#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 a Lua stack. Field 'tbclist' forms a list of all
** to-be-closed variables active in this stack. Dummy entries are
** used when the distance between two tbc variables does not fit
** in an unsigned short. They are represented by delta==0, and
** their real delta is always the maximum value that fits in
** that field.
*/
typedef union StackValue {
TValue val;
struct {
TValuefields;
unsigned short delta;
} tbclist;
} StackValue;
/* index to stack elements */
typedef StackValue *StkId;
/*
** When reallocating the stack, change all pointers to the stack into
** proper offsets.
*/
typedef union {
StkId p; /* actual pointer */
ptrdiff_t offset; /* used while the stack is being reallocated */
} StkIdRel;
/* 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;
/* }================================================================== */
/*
** {==================================================================
** Functions
** ===================================================================
*/
#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 ttisLclosure(o) checktag((o), ctb(LUA_VLCL))
#define ttislcf(o) checktag((o), LUA_VLCF)
#define ttisCclosure(o) checktag((o), ctb(LUA_VCCL))
#define ttisclosure(o) (ttisLclosure(o) || ttisCclosure(o))
#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 */
union {
TValue *p; /* points to stack or to its own value */
ptrdiff_t offset; /* used while the stack is being reallocated */
} v;
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)->flags & BITRAS))
#define setrealasize(t) ((t)->flags &= cast_byte(~BITRAS))
#define setnorealasize(t) ((t)->flags |= 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;
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)
/*
** Dead keys in tables have the tag DEADKEY but keep their original
** gcvalue. This distinguishes them from regular keys but allows them to
** be found when searched in a special way. ('next' needs that to find
** keys removed from a table during a traversal.)
*/
#define setdeadkey(node) (keytt(node) = LUA_TDEADKEY)
#define keyisdead(node) (keytt(node) == LUA_TDEADKEY)
/* }================================================================== */
/*
** '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