src/lundump.c

   1 /*
   2 ** $Id: lundump.c,v 2.7.1.2 2008/01/18 16:39:11 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 #ifdef LUAC_TRUST_BINARIES
  31 #define IF(c,s)
  32 #define error(S,s)
  33 #else
  34 #define IF(c,s)         if (c) error(S,s)
  35
  36 static void error(LoadState* S, const char* why)
  37 {
  38  luaO_pushfstring(S->L,"%s: %s in precompiled chunk",S->name,why);
  39  luaD_throw(S->L,LUA_ERRSYNTAX);
  40 }
  41 #endif
  42
  43 #define LoadMem(S,b,n,size)     LoadBlock(S,b,(n)*(size))
  44 #define LoadByte(S)             (lu_byte)LoadChar(S)
  45 #define LoadVar(S,x)            LoadMem(S,&x,1,sizeof(x))
  46 #define LoadVector(S,b,n,size)  LoadMem(S,b,n,size)
  47
  48 static void LoadBlock(LoadState* S, void* b, size_t size)
  49 {
  50  size_t r=luaZ_read(S->Z,b,size);
  51  UNUSED(r);
  52  IF (r!=0, "unexpected end");
  53 }
  54
  55 static int LoadChar(LoadState* S)
  56 {
  57  char x;
  58  LoadVar(S,x);
  59  return x;
  60 }
  61
  62 static int LoadInt(LoadState* S)
  63 {
  64  int x;
  65  LoadVar(S,x);
  66  IF (x<0, "bad integer");
  67  return x;
  68 }
  69
  70 static lua_Number LoadNumber(LoadState* S)
  71 {
  72  lua_Number x;
  73  LoadVar(S,x);
  74  return x;
  75 }
  76
  77 static TString* LoadString(LoadState* S)
  78 {
  79  size_t size;
  80  LoadVar(S,size);
  81  if (size==0)
  82   return NULL;
  83  else
  84  {
  85   char* s=luaZ_openspace(S->L,S->b,size);
  86   LoadBlock(S,s,size);
  87   return luaS_newlstr(S->L,s,size-1);           /* remove trailing '\0' */
  88  }
  89 }
  90
  91 static void LoadCode(LoadState* S, Proto* f)
  92 {
  93  int n=LoadInt(S);
  94  f->code=luaM_newvector(S->L,n,Instruction);
  95  f->sizecode=n;
  96  LoadVector(S,f->code,n,sizeof(Instruction));
  97 }
  98
  99 static Proto* LoadFunction(LoadState* S, TString* p);
 100
 101 static void LoadConstants(LoadState* S, Proto* f)
 102 {
 103  int i,n;
 104  n=LoadInt(S);
 105  f->k=luaM_newvector(S->L,n,TValue);
 106  f->sizek=n;
 107  for (i=0; i<n; i++) setnilvalue(&f->k[i]);
 108  for (i=0; i<n; i++)
 109  {
 110   TValue* o=&f->k[i];
 111   int t=LoadChar(S);
 112   switch (t)
 113   {
 114    case LUA_TNIL:
 115         setnilvalue(o);
 116         break;
 117    case LUA_TBOOLEAN:
 118         setbvalue(o,LoadChar(S));
 119         break;
 120    case LUA_TNUMBER:
 121         setnvalue(o,LoadNumber(S));
 122         break;
 123    case LUA_TSTRING:
 124         setsvalue2n(S->L,o,LoadString(S));
 125         break;
 126    default:
 127         error(S,"bad constant");
 128         break;
 129   }
 130  }
 131  n=LoadInt(S);
 132  f->p=luaM_newvector(S->L,n,Proto*);
 133  f->sizep=n;
 134  for (i=0; i<n; i++) f->p[i]=NULL;
 135  for (i=0; i<n; i++) f->p[i]=LoadFunction(S,f->source);
 136 }
 137
 138 static void LoadDebug(LoadState* S, Proto* f)
 139 {
 140  int i,n;
 141  n=LoadInt(S);
 142  f->lineinfo=luaM_newvector(S->L,n,int);
 143  f->sizelineinfo=n;
 144  LoadVector(S,f->lineinfo,n,sizeof(int));
 145  n=LoadInt(S);
 146  f->locvars=luaM_newvector(S->L,n,LocVar);
 147  f->sizelocvars=n;
 148  for (i=0; i<n; i++) f->locvars[i].varname=NULL;
 149  for (i=0; i<n; i++)
 150  {
 151   f->locvars[i].varname=LoadString(S);
 152   f->locvars[i].startpc=LoadInt(S);
 153   f->locvars[i].endpc=LoadInt(S);
 154  }
 155  n=LoadInt(S);
 156  f->upvalues=luaM_newvector(S->L,n,TString*);
 157  f->sizeupvalues=n;
 158  for (i=0; i<n; i++) f->upvalues[i]=NULL;
 159  for (i=0; i<n; i++) f->upvalues[i]=LoadString(S);
 160 }
 161
 162 static Proto* LoadFunction(LoadState* S, TString* p)
 163 {
 164  Proto* f=luaF_newproto(S->L);
 165  setptvalue2s(S->L,S->L->top,f); incr_top(S->L);
 166  f->source=LoadString(S); if (f->source==NULL) f->source=p;
 167  f->linedefined=LoadInt(S);
 168  f->lastlinedefined=LoadInt(S);
 169  f->nups=LoadByte(S);
 170  f->numparams=LoadByte(S);
 171  f->is_vararg=LoadByte(S);
 172  f->maxstacksize=LoadByte(S);
 173  LoadCode(S,f);
 174  LoadConstants(S,f);
 175  LoadDebug(S,f);
 176  IF (!luaG_checkcode(f), "bad code");
 177  S->L->top--;
 178  return f;
 179 }
 180
 181 static void LoadHeader(LoadState* S)
 182 {
 183  char h[LUAC_HEADERSIZE];
 184  char s[LUAC_HEADERSIZE];
 185  luaU_header(h);
 186  LoadBlock(S,s,LUAC_HEADERSIZE);
 187  IF (memcmp(h,s,LUAC_HEADERSIZE)!=0, "bad header");
 188 }
 189
 190 /*
 191 ** load precompiled chunk
 192 */
 193 Proto* luaU_undump (lua_State* L, ZIO* Z, Mbuffer* buff, const char* name)
 194 {
 195  LoadState S;
 196  if (*name=='@' || *name=='=')
 197   S.name=name+1;
 198  else if (*name==LUA_SIGNATURE[0])
 199   S.name="binary string";
 200  else
 201   S.name=name;
 202  S.L=L;
 203  S.Z=Z;
 204  S.b=buff;
 205  LoadHeader(&S);
 206  return LoadFunction(&S,luaS_newliteral(L,"=?"));
 207 }
 208
 209 /*
 210 * make header
 211 */
 212 void luaU_header (char* h)
 213 {
 214  int x=1;
 215  memcpy(h,LUA_SIGNATURE,sizeof(LUA_SIGNATURE)-1);
 216  h+=sizeof(LUA_SIGNATURE)-1;
 217  *h++=(char)LUAC_VERSION;
 218  *h++=(char)LUAC_FORMAT;
 219  *h++=(char)*(char*)&x;                         /* endianness */
 220  *h++=(char)sizeof(int);
 221  *h++=(char)sizeof(size_t);
 222  *h++=(char)sizeof(Instruction);
 223  *h++=(char)sizeof(lua_Number);
 224  *h++=(char)(((lua_Number)0.5)==0);             /* is lua_Number integral? */
 225 }