Lua 5.3.4 里的 lundump.c
lundump.h 定义了一些宏跟声明了 luaU_undump 跟 luaU_dump。
#ifndef lundump_h
#define lundump_h
#include "llimits.h"
#include "lobject.h"
#include "lzio.h"
/* data to catch conversion errors */
#define LUAC_DATA "\x19\x93\r\n\x1a\n"
#define LUAC_INT 0x5678
#define LUAC_NUM cast_num(370.5)
#define MYINT(s) (s[0]-'0')
#define LUAC_VERSION (MYINT(LUA_VERSION_MAJOR)*16+MYINT(LUA_VERSION_MINOR))
#define LUAC_FORMAT 0 /* this is the official format */
/* load one chunk; from lundump.c */
LUAI_FUNC LClosure* luaU_undump (lua_State* L, ZIO* Z, const char* name);
/* dump one chunk; from ldump.c */
LUAI_FUNC int luaU_dump (lua_State* L, const Proto* f, lua_Writer w,
void* data, int strip);
#endiflundump.c 其实跟 ldump.c 差不多。它主要是 luaU_undump 方法，这个方法从 ZIO *Z 里面读入数据，最终返回一个闭包。
/*
** load precompiled chunk
*/
LClosure *luaU_undump(lua_State *L, ZIO *Z, const char *name) {
LoadState S;
LClosure *cl;
if (*name == '@' || *name == '=')
S.name = name + 1;
else if (*name == LUA_SIGNATURE[0])
S.name = "binary string";
else
S.name = name;
S.L = L;
S.Z = Z;
checkHeader(&S);
cl = luaF_newLclosure(L, LoadByte(&S));
setclLvalue(L, L->top, cl);
luaD_inctop(L);
cl->p = luaF_newproto(L);
LoadFunction(&S, cl->p, NULL);
lua_assert(cl->nupvalues == cl->p->sizeupvalues);
luai_verifycode(L, buff, cl->p);
return cl;
}而其它的则都是检查或者读入数据转成代码或者数据。
#define LUA_CORE
#include "lprefix.h"
#include <string.h>
#include "lua.h"
#include "ldebug.h"
#include "ldo.h"
#include "lfunc.h"
#include "lmem.h"
#include "lobject.h"
#include "lstring.h"
#include "lundump.h"
#include "lzio.h"
#if !defined(luai_verifycode)
#define luai_verifycode(L,b,f) /* empty */
#endif
typedef struct {
lua_State *L;
ZIO *Z;
const char *name;
} LoadState;
static l_noret error(LoadState *S, const char *why) {
luaO_pushfstring(S->L, "%s: %s precompiled chunk", S->name, why);
luaD_throw(S->L, LUA_ERRSYNTAX);
}
/*
** All high-level loads go through LoadVector; you can change it to
** adapt to the endianness of the input
*/
#define LoadVector(S,b,n) LoadBlock(S,b,(n)*sizeof((b)[0]))
static void LoadBlock (LoadState *S, void *b, size_t size) {
if (luaZ_read(S->Z, b, size) != 0)
error(S, "truncated");
}
#define LoadVar(S,x) LoadVector(S,&x,1)
static lu_byte LoadByte (LoadState *S) {
lu_byte x;
LoadVar(S, x);
return x;
}
static int LoadInt (LoadState *S) {
int x;
LoadVar(S, x);
return x;
}
static lua_Number LoadNumber (LoadState *S) {
lua_Number x;
LoadVar(S, x);
return x;
}
static lua_Integer LoadInteger (LoadState *S) {
lua_Integer x;
LoadVar(S, x);
return x;
}
static TString *LoadString (LoadState *S) {
size_t size = LoadByte(S);
if (size == 0xFF)
LoadVar(S, size);
if (size == 0)
return NULL;
else if (--size <= LUAI_MAXSHORTLEN) { /* short string? */
char buff[LUAI_MAXSHORTLEN];
LoadVector(S, buff, size);
return luaS_newlstr(S->L, buff, size);
}
else { /* long string */
TString *ts = luaS_createlngstrobj(S->L, size);
LoadVector(S, getstr(ts), size); /* load directly in final place */
return ts;
}
}
static void LoadCode (LoadState *S, Proto *f) {
int n = LoadInt(S);
f->code = luaM_newvector(S->L, n, Instruction);
f->sizecode = n;
LoadVector(S, f->code, n);
}
static void LoadFunction(LoadState *S, Proto *f, TString *psource);
static void LoadConstants (LoadState *S, Proto *f) {
int i;
int n = LoadInt(S);
f->k = luaM_newvector(S->L, n, TValue);
f->sizek = n;
for (i = 0; i < n; i++)
setnilvalue(&f->k[i]);
for (i = 0; i < n; i++) {
TValue *o = &f->k[i];
int t = LoadByte(S);
switch (t) {
case LUA_TNIL:
setnilvalue(o);
break;
case LUA_TBOOLEAN:
setbvalue(o, LoadByte(S));
break;
case LUA_TNUMFLT:
setfltvalue(o, LoadNumber(S));
break;
case LUA_TNUMINT:
setivalue(o, LoadInteger(S));
break;
case LUA_TSHRSTR:
case LUA_TLNGSTR:
setsvalue2n(S->L, o, LoadString(S));
break;
default:
lua_assert(0);
}
}
}
static void LoadProtos (LoadState *S, Proto *f) {
int i;
int n = LoadInt(S);
f->p = luaM_newvector(S->L, n, Proto *);
f->sizep = n;
for (i = 0; i < n; i++)
f->p[i] = NULL;
for (i = 0; i < n; i++) {
f->p[i] = luaF_newproto(S->L);
LoadFunction(S, f->p[i], f->source);
}
}
static void LoadUpvalues (LoadState *S, Proto *f) {
int i, n;
n = LoadInt(S);
f->upvalues = luaM_newvector(S->L, n, Upvaldesc);
f->sizeupvalues = n;
for (i = 0; i < n; i++)
f->upvalues[i].name = NULL;
for (i = 0; i < n; i++) {
f->upvalues[i].instack = LoadByte(S);
f->upvalues[i].idx = LoadByte(S);
}
}
static void LoadDebug (LoadState *S, Proto *f) {
int i, n;
n = LoadInt(S);
f->lineinfo = luaM_newvector(S->L, n, int);
f->sizelineinfo = n;
LoadVector(S, f->lineinfo, n);
n = LoadInt(S);
f->locvars = luaM_newvector(S->L, n, LocVar);
f->sizelocvars = n;
for (i = 0; i < n; i++)
f->locvars[i].varname = NULL;
for (i = 0; i < n; i++) {
f->locvars[i].varname = LoadString(S);
f->locvars[i].startpc = LoadInt(S);
f->locvars[i].endpc = LoadInt(S);
}
n = LoadInt(S);
for (i = 0; i < n; i++)
f->upvalues[i].name = LoadString(S);
}
static void LoadFunction (LoadState *S, Proto *f, TString *psource) {
f->source = LoadString(S);
if (f->source == NULL) /* no source in dump? */
f->source = psource; /* reuse parent's source */
f->linedefined = LoadInt(S);
f->lastlinedefined = LoadInt(S);
f->numparams = LoadByte(S);
f->is_vararg = LoadByte(S);
f->maxstacksize = LoadByte(S);
LoadCode(S, f);
LoadConstants(S, f);
LoadUpvalues(S, f);
LoadProtos(S, f);
LoadDebug(S, f);
}
static void checkliteral (LoadState *S, const char *s, const char *msg) {
char buff[sizeof(LUA_SIGNATURE) + sizeof(LUAC_DATA)]; /* larger than both */
size_t len = strlen(s);
LoadVector(S, buff, len);
if (memcmp(s, buff, len) != 0)
error(S, msg);
}
static void fchecksize (LoadState *S, size_t size, const char *tname) {
if (LoadByte(S) != size)
error(S, luaO_pushfstring(S->L, "%s size mismatch in", tname));
}
#define checksize(S,t) fchecksize(S,sizeof(t),#t)
static void checkHeader (LoadState *S) {
checkliteral(S, LUA_SIGNATURE + 1, "not a"); /* 1st char already checked */
if (LoadByte(S) != LUAC_VERSION)
error(S, "version mismatch in");
if (LoadByte(S) != LUAC_FORMAT)
error(S, "format mismatch in");
checkliteral(S, LUAC_DATA, "corrupted");
checksize(S, int);
checksize(S, size_t);
checksize(S, Instruction);
checksize(S, lua_Integer);
checksize(S, lua_Number);
if (LoadInteger(S) != LUAC_INT)
error(S, "endianness mismatch in");
if (LoadNumber(S) != LUAC_NUM)
error(S, "float format mismatch in");
}