/*

** $Id: lundump.c,v 2.7.1.4 2008/04/04 19:51:41 roberto Exp $

** load precompiled Lua chunks

** See Copyright Notice in lua.h

*/

#include <string.h>

#define lundump_c

#define LUA_CORE

#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"

typedef struct {

 lua_State* L;

 ZIO* Z;

 Mbuffer* b;

 const char* name;

} LoadState;

#ifdef LUAC_TRUST_BINARIES

#define IF(c,s)

#define error(S,s)

#else

#define IF(c,s)		if (c) error(S,s)

static void error(LoadState* S, const char* why)

{

 luaO_pushfstring(S->L,"%s: %s in precompiled chunk",S->name,why);

 luaD_throw(S->L,LUA_ERRSYNTAX);

}

#endif

#define LoadMem(S,b,n,size)	LoadBlock(S,b,(n)*(size))

#define	LoadByte(S)		(lu_byte)LoadChar(S)

#define LoadVar(S,x)		LoadMem(S,&x,1,sizeof(x))

#define LoadVector(S,b,n,size)	LoadMem(S,b,n,size)

static void LoadBlock(LoadState* S, void* b, size_t size)

{

 size_t r=luaZ_read(S->Z,b,size);

 IF (r!=0, "unexpected end");

}

static int LoadChar(LoadState* S)

{

 char x;

 LoadVar(S,x);

 return x;

}

static int LoadInt(LoadState* S)

{

 int x;

 LoadVar(S,x);

 IF (x<0, "bad integer");

 return x;

}

static lua_Number LoadNumber(LoadState* S)

{

 lua_Number x;

 LoadVar(S,x);

 return x;

}

static TString* LoadString(LoadState* S)

{

 size_t size;

 LoadVar(S,size);

 if (size==0)

  return NULL;

 else

 {

  char* s=luaZ_openspace(S->L,S->b,size);

  LoadBlock(S,s,size);

  return luaS_newlstr(S->L,s,size-1);		/* remove trailing '\0' */

 }

}

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,sizeof(Instruction));

}

static Proto* LoadFunction(LoadState* S, TString* p);

static void LoadConstants(LoadState* S, Proto* f)

{

 int i,n;

 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=LoadChar(S);

  switch (t)

  {

   case LUA_TNIL:

   	setnilvalue(o);

	break;

   case LUA_TBOOLEAN:

   	setbvalue(o,LoadChar(S)!=0);

	break;

   case LUA_TNUMBER:

	setnvalue(o,LoadNumber(S));

	break;

   case LUA_TSTRING:

	setsvalue2n(S->L,o,LoadString(S));

	break;

   default:

	error(S,"bad constant");

	break;

  }

 }

 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]=LoadFunction(S,f->source);

}

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,sizeof(int));

 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);

 f->upvalues=luaM_newvector(S->L,n,TString*);

 f->sizeupvalues=n;

 for (i=0; i<n; i++) f->upvalues[i]=NULL;

 for (i=0; i<n; i++) f->upvalues[i]=LoadString(S);

}

static Proto* LoadFunction(LoadState* S, TString* p)

{

 Proto* f;

 if (++S->L->nCcalls > LUAI_MAXCCALLS) error(S,"code too deep");

 f=luaF_newproto(S->L);

 setptvalue2s(S->L,S->L->top,f); incr_top(S->L);

 f->source=LoadString(S); if (f->source==NULL) f->source=p;

 f->linedefined=LoadInt(S);

 f->lastlinedefined=LoadInt(S);

 f->nups=LoadByte(S);

 f->numparams=LoadByte(S);

 f->is_vararg=LoadByte(S);

 f->maxstacksize=LoadByte(S);

 LoadCode(S,f);

 LoadConstants(S,f);

 LoadDebug(S,f);

 IF (!luaG_checkcode(f), "bad code");

 S->L->top--;

 S->L->nCcalls--;

 return f;

}

static void LoadHeader(LoadState* S)

{

 char h[LUAC_HEADERSIZE];

 char s[LUAC_HEADERSIZE];

 luaU_header(h);

 LoadBlock(S,s,LUAC_HEADERSIZE);

 IF (memcmp(h,s,LUAC_HEADERSIZE)!=0, "bad header");

}

/*

** load precompiled chunk

*/

Proto* luaU_undump (lua_State* L, ZIO* Z, Mbuffer* buff, const char* name)

{

 LoadState S;

 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;

 S.b=buff;

 LoadHeader(&S);

 return LoadFunction(&S,luaS_newliteral(L,"=?"));

}

/*

* make header

*/

void luaU_header (char* h)

{

 int x=1;

 memcpy(h,LUA_SIGNATURE,sizeof(LUA_SIGNATURE)-1);

 h+=sizeof(LUA_SIGNATURE)-1;

 *h++=(char)LUAC_VERSION;

 *h++=(char)LUAC_FORMAT;

 *h++=(char)*(char*)&x;				/* endianness */

 *h++=(char)sizeof(int);

 *h++=(char)sizeof(size_t);

 *h++=(char)sizeof(Instruction);

 *h++=(char)sizeof(lua_Number);

 *h++=(char)(((lua_Number)0.5)==0);		/* is lua_Number integral? */

}