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      1 /*
      2 ** $Id: lundump.c,v 2.22 2012/05/08 13:53:33 roberto Exp $
      3 ** load precompiled Lua chunks
      4 ** See Copyright Notice in lua.h
      5 */
      6 
      7 #include <string.h>
      8 
      9 #define lundump_c
     10 #define LUA_CORE
     11 
     12 #include "lua.h"
     13 
     14 #include "ldebug.h"
     15 #include "ldo.h"
     16 #include "lfunc.h"
     17 #include "lmem.h"
     18 #include "lobject.h"
     19 #include "lstring.h"
     20 #include "lundump.h"
     21 #include "lzio.h"
     22 
     23 typedef struct {
     24  lua_State* L;
     25  ZIO* Z;
     26  Mbuffer* b;
     27  const char* name;
     28 } LoadState;
     29 
     30 static l_noret error(LoadState* S, const char* why)
     31 {
     32  luaO_pushfstring(S->L,"%s: %s precompiled chunk",S->name,why);
     33  luaD_throw(S->L,LUA_ERRSYNTAX);
     34 }
     35 
     36 #define LoadMem(S,b,n,size)	LoadBlock(S,b,(n)*(size))
     37 #define LoadByte(S)		(lu_byte)LoadChar(S)
     38 #define LoadVar(S,x)		LoadMem(S,&x,1,sizeof(x))
     39 #define LoadVector(S,b,n,size)	LoadMem(S,b,n,size)
     40 
     41 #if !defined(luai_verifycode)
     42 #define luai_verifycode(L,b,f)	/* empty */
     43 #endif
     44 
     45 static void LoadBlock(LoadState* S, void* b, size_t size)
     46 {
     47  if (luaZ_read(S->Z,b,size)!=0) error(S,"truncated");
     48 }
     49 
     50 static int LoadChar(LoadState* S)
     51 {
     52  char x;
     53  LoadVar(S,x);
     54  return x;
     55 }
     56 
     57 static int LoadInt(LoadState* S)
     58 {
     59  int x;
     60  LoadVar(S,x);
     61  if (x<0) error(S,"corrupted");
     62  return x;
     63 }
     64 
     65 static lua_Number LoadNumber(LoadState* S)
     66 {
     67  lua_Number x;
     68  LoadVar(S,x);
     69  return x;
     70 }
     71 
     72 static TString* LoadString(LoadState* S)
     73 {
     74  size_t size;
     75  LoadVar(S,size);
     76  if (size==0)
     77   return NULL;
     78  else
     79  {
     80   char* s=luaZ_openspace(S->L,S->b,size);
     81   LoadBlock(S,s,size*sizeof(char));
     82   return luaS_newlstr(S->L,s,size-1);		/* remove trailing '\0' */
     83  }
     84 }
     85 
     86 static void LoadCode(LoadState* S, Proto* f)
     87 {
     88  int n=LoadInt(S);
     89  f->code=luaM_newvector(S->L,n,Instruction);
     90  f->sizecode=n;
     91  LoadVector(S,f->code,n,sizeof(Instruction));
     92 }
     93 
     94 static void LoadFunction(LoadState* S, Proto* f);
     95 
     96 static void LoadConstants(LoadState* S, Proto* f)
     97 {
     98  int i,n;
     99  n=LoadInt(S);
    100  f->k=luaM_newvector(S->L,n,TValue);
    101  f->sizek=n;
    102  for (i=0; i<n; i++) setnilvalue(&f->k[i]);
    103  for (i=0; i<n; i++)
    104  {
    105   TValue* o=&f->k[i];
    106   int t=LoadChar(S);
    107   switch (t)
    108   {
    109    case LUA_TNIL:
    110 	setnilvalue(o);
    111 	break;
    112    case LUA_TBOOLEAN:
    113 	setbvalue(o,LoadChar(S));
    114 	break;
    115    case LUA_TNUMBER:
    116 	setnvalue(o,LoadNumber(S));
    117 	break;
    118    case LUA_TSTRING:
    119 	setsvalue2n(S->L,o,LoadString(S));
    120 	break;
    121     default: lua_assert(0);
    122   }
    123  }
    124  n=LoadInt(S);
    125  f->p=luaM_newvector(S->L,n,Proto*);
    126  f->sizep=n;
    127  for (i=0; i<n; i++) f->p[i]=NULL;
    128  for (i=0; i<n; i++)
    129  {
    130   f->p[i]=luaF_newproto(S->L);
    131   LoadFunction(S,f->p[i]);
    132  }
    133 }
    134 
    135 static void LoadUpvalues(LoadState* S, Proto* f)
    136 {
    137  int i,n;
    138  n=LoadInt(S);
    139  f->upvalues=luaM_newvector(S->L,n,Upvaldesc);
    140  f->sizeupvalues=n;
    141  for (i=0; i<n; i++) f->upvalues[i].name=NULL;
    142  for (i=0; i<n; i++)
    143  {
    144   f->upvalues[i].instack=LoadByte(S);
    145   f->upvalues[i].idx=LoadByte(S);
    146  }
    147 }
    148 
    149 static void LoadDebug(LoadState* S, Proto* f)
    150 {
    151  int i,n;
    152  f->source=LoadString(S);
    153  n=LoadInt(S);
    154  f->lineinfo=luaM_newvector(S->L,n,int);
    155  f->sizelineinfo=n;
    156  LoadVector(S,f->lineinfo,n,sizeof(int));
    157  n=LoadInt(S);
    158  f->locvars=luaM_newvector(S->L,n,LocVar);
    159  f->sizelocvars=n;
    160  for (i=0; i<n; i++) f->locvars[i].varname=NULL;
    161  for (i=0; i<n; i++)
    162  {
    163   f->locvars[i].varname=LoadString(S);
    164   f->locvars[i].startpc=LoadInt(S);
    165   f->locvars[i].endpc=LoadInt(S);
    166  }
    167  n=LoadInt(S);
    168  for (i=0; i<n; i++) f->upvalues[i].name=LoadString(S);
    169 }
    170 
    171 static void LoadFunction(LoadState* S, Proto* f)
    172 {
    173  f->linedefined=LoadInt(S);
    174  f->lastlinedefined=LoadInt(S);
    175  f->numparams=LoadByte(S);
    176  f->is_vararg=LoadByte(S);
    177  f->maxstacksize=LoadByte(S);
    178  LoadCode(S,f);
    179  LoadConstants(S,f);
    180  LoadUpvalues(S,f);
    181  LoadDebug(S,f);
    182 }
    183 
    184 /* the code below must be consistent with the code in luaU_header */
    185 #define N0	LUAC_HEADERSIZE
    186 #define N1	(sizeof(LUA_SIGNATURE)-sizeof(char))
    187 #define N2	N1+2
    188 #define N3	N2+6
    189 
    190 static void LoadHeader(LoadState* S)
    191 {
    192  lu_byte h[LUAC_HEADERSIZE];
    193  lu_byte s[LUAC_HEADERSIZE];
    194  luaU_header(h);
    195  memcpy(s,h,sizeof(char));			/* first char already read */
    196  LoadBlock(S,s+sizeof(char),LUAC_HEADERSIZE-sizeof(char));
    197  if (memcmp(h,s,N0)==0) return;
    198  if (memcmp(h,s,N1)!=0) error(S,"not a");
    199  if (memcmp(h,s,N2)!=0) error(S,"version mismatch in");
    200  if (memcmp(h,s,N3)!=0) error(S,"incompatible"); else error(S,"corrupted");
    201 }
    202 
    203 /*
    204 ** load precompiled chunk
    205 */
    206 Closure* luaU_undump (lua_State* L, ZIO* Z, Mbuffer* buff, const char* name)
    207 {
    208  LoadState S;
    209  Closure* cl;
    210  if (*name=='@' || *name=='=')
    211   S.name=name+1;
    212  else if (*name==LUA_SIGNATURE[0])
    213   S.name="binary string";
    214  else
    215   S.name=name;
    216  S.L=L;
    217  S.Z=Z;
    218  S.b=buff;
    219  LoadHeader(&S);
    220  cl=luaF_newLclosure(L,1);
    221  setclLvalue(L,L->top,cl); incr_top(L);
    222  cl->l.p=luaF_newproto(L);
    223  LoadFunction(&S,cl->l.p);
    224  if (cl->l.p->sizeupvalues != 1)
    225  {
    226   Proto* p=cl->l.p;
    227   cl=luaF_newLclosure(L,cl->l.p->sizeupvalues);
    228   cl->l.p=p;
    229   setclLvalue(L,L->top-1,cl);
    230  }
    231  luai_verifycode(L,buff,cl->l.p);
    232  return cl;
    233 }
    234 
    235 #define MYINT(s)	(s[0]-'0')
    236 #define VERSION		MYINT(LUA_VERSION_MAJOR)*16+MYINT(LUA_VERSION_MINOR)
    237 #define FORMAT		0		/* this is the official format */
    238 
    239 /*
    240 * make header for precompiled chunks
    241 * if you change the code below be sure to update LoadHeader and FORMAT above
    242 * and LUAC_HEADERSIZE in lundump.h
    243 */
    244 void luaU_header (lu_byte* h)
    245 {
    246  int x=1;
    247  memcpy(h,LUA_SIGNATURE,sizeof(LUA_SIGNATURE)-sizeof(char));
    248  h+=sizeof(LUA_SIGNATURE)-sizeof(char);
    249  *h++=cast_byte(VERSION);
    250  *h++=cast_byte(FORMAT);
    251  *h++=cast_byte(*(char*)&x);			/* endianness */
    252  *h++=cast_byte(sizeof(int));
    253  *h++=cast_byte(sizeof(size_t));
    254  *h++=cast_byte(sizeof(Instruction));
    255  *h++=cast_byte(sizeof(lua_Number));
    256  *h++=cast_byte(((lua_Number)0.5)==0);		/* is lua_Number integral? */
    257  memcpy(h,LUAC_TAIL,sizeof(LUAC_TAIL)-sizeof(char));
    258 }
    259