lua/src/lundump.c

   1 /*
   2 ** $Id: lundump.c,v 1.60 2006/02/16 15:53:49 lhf 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 #else
  33 #define IF(c,s)         if (c) error(S,s)
  34
  35 static void error(LoadState* S, const char* why)
  36 {
  37  luaO_pushfstring(S->L,"%s: %s in precompiled chunk",S->name,why);
  38  luaD_throw(S->L,LUA_ERRSYNTAX);
  39 }
  40 #endif
  41
  42 #define LoadMem(S,b,n,size)     LoadBlock(S,b,(n)*(size))
  43 #define LoadByte(S)             (lu_byte)LoadChar(S)
  44 #define LoadVar(S,x)            LoadMem(S,&x,1,sizeof(x))
  45 #define LoadVector(S,b,n,size)  LoadMem(S,b,n,size)
  46
  47 static void LoadBlock(LoadState* S, void* b, size_t size)
  48 {
  49  size_t r=luaZ_read(S->Z,b,size);
  50  IF (r!=0, "unexpected end");
  51 }
  52
  53 static int LoadChar(LoadState* S)
  54 {
  55  char x;
  56  LoadVar(S,x);
  57  return x;
  58 }
  59
  60 static int LoadInt(LoadState* S)
  61 {
  62  int x;
  63  LoadVar(S,x);
  64  IF (x<0, "bad integer");
  65  return x;
  66 }
  67
  68 static lua_Number LoadNumber(LoadState* S)
  69 {
  70  lua_Number x;
  71  LoadVar(S,x);
  72  return x;
  73 }
  74
  75 static TString* LoadString(LoadState* S)
  76 {
  77  size_t size;
  78  LoadVar(S,size);
  79  if (size==0)
  80   return NULL;
  81  else
  82  {
  83   char* s=luaZ_openspace(S->L,S->b,size);
  84   LoadBlock(S,s,size);
  85   return luaS_newlstr(S->L,s,size-1);           /* remove trailing '\0' */
  86  }
  87 }
  88
  89 static void LoadCode(LoadState* S, Proto* f)
  90 {
  91  int n=LoadInt(S);
  92  f->code=luaM_newvector(S->L,n,Instruction);
  93  f->sizecode=n;
  94  LoadVector(S,f->code,n,sizeof(Instruction));
  95 }
  96
  97 static Proto* LoadFunction(LoadState* S, TString* p);
  98
  99 static void LoadConstants(LoadState* S, Proto* f)
 100 {
 101  int i,n;
 102  n=LoadInt(S);
 103  f->k=luaM_newvector(S->L,n,TValue);
 104  f->sizek=n;
 105  for (i=0; i<n; i++) setnilvalue(&f->k[i]);
 106  for (i=0; i<n; i++)
 107  {
 108   TValue* o=&f->k[i];
 109   int t=LoadChar(S);
 110   switch (t)
 111   {
 112    case LUA_TNIL:
 113         setnilvalue(o);
 114         break;
 115    case LUA_TBOOLEAN:
 116         setbvalue(o,LoadChar(S));
 117         break;
 118    case LUA_TNUMBER:
 119         setnvalue(o,LoadNumber(S));
 120         break;
 121    case LUA_TSTRING:
 122         setsvalue2n(S->L,o,LoadString(S));
 123         break;
 124    default:
 125         IF (1, "bad constant");
 126         break;
 127   }
 128  }
 129  n=LoadInt(S);
 130  f->p=luaM_newvector(S->L,n,Proto*);
 131  f->sizep=n;
 132  for (i=0; i<n; i++) f->p[i]=NULL;
 133  for (i=0; i<n; i++) f->p[i]=LoadFunction(S,f->source);
 134 }
 135
 136 static void LoadDebug(LoadState* S, Proto* f)
 137 {
 138  int i,n;
 139  n=LoadInt(S);
 140  f->lineinfo=luaM_newvector(S->L,n,int);
 141  f->sizelineinfo=n;
 142  LoadVector(S,f->lineinfo,n,sizeof(int));
 143  n=LoadInt(S);
 144  f->locvars=luaM_newvector(S->L,n,LocVar);
 145  f->sizelocvars=n;
 146  for (i=0; i<n; i++) f->locvars[i].varname=NULL;
 147  for (i=0; i<n; i++)
 148  {
 149   f->locvars[i].varname=LoadString(S);
 150   f->locvars[i].startpc=LoadInt(S);
 151   f->locvars[i].endpc=LoadInt(S);
 152  }
 153  n=LoadInt(S);
 154  f->upvalues=luaM_newvector(S->L,n,TString*);
 155  f->sizeupvalues=n;
 156  for (i=0; i<n; i++) f->upvalues[i]=NULL;
 157  for (i=0; i<n; i++) f->upvalues[i]=LoadString(S);
 158 }
 159
 160 static Proto* LoadFunction(LoadState* S, TString* p)
 161 {
 162  Proto* f=luaF_newproto(S->L);
 163  setptvalue2s(S->L,S->L->top,f); incr_top(S->L);
 164  f->source=LoadString(S); if (f->source==NULL) f->source=p;
 165  f->linedefined=LoadInt(S);
 166  f->lastlinedefined=LoadInt(S);
 167  f->nups=LoadByte(S);
 168  f->numparams=LoadByte(S);
 169  f->is_vararg=LoadByte(S);
 170  f->maxstacksize=LoadByte(S);
 171  LoadCode(S,f);
 172  LoadConstants(S,f);
 173  LoadDebug(S,f);
 174  IF (!luaG_checkcode(f), "bad code");
 175  S->L->top--;
 176  return f;
 177 }
 178
 179 static void LoadHeader(LoadState* S)
 180 {
 181  char h[LUAC_HEADERSIZE];
 182  char s[LUAC_HEADERSIZE];
 183  luaU_header(h);
 184  LoadBlock(S,s,LUAC_HEADERSIZE);
 185  IF (memcmp(h,s,LUAC_HEADERSIZE)!=0, "bad header");
 186 }
 187
 188 /*
 189 ** load precompiled chunk
 190 */
 191 Proto* luaU_undump (lua_State* L, ZIO* Z, Mbuffer* buff, const char* name)
 192 {
 193  LoadState S;
 194  if (*name=='@' || *name=='=')
 195   S.name=name+1;
 196  else if (*name==LUA_SIGNATURE[0])
 197   S.name="binary string";
 198  else
 199   S.name=name;
 200  S.L=L;
 201  S.Z=Z;
 202  S.b=buff;
 203  LoadHeader(&S);
 204  return LoadFunction(&S,luaS_newliteral(L,"=?"));
 205 }
 206
 207 /*
 208 * make header
 209 */
 210 void luaU_header (char* h)
 211 {
 212  int x=1;
 213  memcpy(h,LUA_SIGNATURE,sizeof(LUA_SIGNATURE)-1);
 214  h+=sizeof(LUA_SIGNATURE)-1;
 215  *h++=(char)LUAC_VERSION;
 216  *h++=(char)LUAC_FORMAT;
 217  *h++=(char)*(char*)&x;                         /* endianness */
 218  *h++=(char)sizeof(int);
 219  *h++=(char)sizeof(size_t);
 220  *h++=(char)sizeof(Instruction);
 221  *h++=(char)sizeof(lua_Number);
 222  *h++=(char)(((lua_Number)0.5)==0);             /* is lua_Number integral? */
 223 }