lua/src/lundump.c

   1 /*
   2 ** $Id: lundump.c,v 1.71 2011/12/07 10:39:12 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 static void 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)  (f)
  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 Proto* LoadFunction(LoadState* S);
  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   }
 122  }
 123  n=LoadInt(S);
 124  f->p=luaM_newvector(S->L,n,Proto*);
 125  f->sizep=n;
 126  for (i=0; i<n; i++) f->p[i]=NULL;
 127  for (i=0; i<n; i++) f->p[i]=LoadFunction(S);
 128 }
 129
 130 static void LoadUpvalues(LoadState* S, Proto* f)
 131 {
 132  int i,n;
 133  n=LoadInt(S);
 134  f->upvalues=luaM_newvector(S->L,n,Upvaldesc);
 135  f->sizeupvalues=n;
 136  for (i=0; i<n; i++) f->upvalues[i].name=NULL;
 137  for (i=0; i<n; i++)
 138  {
 139   f->upvalues[i].instack=LoadByte(S);
 140   f->upvalues[i].idx=LoadByte(S);
 141  }
 142 }
 143
 144 static void LoadDebug(LoadState* S, Proto* f)
 145 {
 146  int i,n;
 147  f->source=LoadString(S);
 148  n=LoadInt(S);
 149  f->lineinfo=luaM_newvector(S->L,n,int);
 150  f->sizelineinfo=n;
 151  LoadVector(S,f->lineinfo,n,sizeof(int));
 152  n=LoadInt(S);
 153  f->locvars=luaM_newvector(S->L,n,LocVar);
 154  f->sizelocvars=n;
 155  for (i=0; i<n; i++) f->locvars[i].varname=NULL;
 156  for (i=0; i<n; i++)
 157  {
 158   f->locvars[i].varname=LoadString(S);
 159   f->locvars[i].startpc=LoadInt(S);
 160   f->locvars[i].endpc=LoadInt(S);
 161  }
 162  n=LoadInt(S);
 163  for (i=0; i<n; i++) f->upvalues[i].name=LoadString(S);
 164 }
 165
 166 static Proto* LoadFunction(LoadState* S)
 167 {
 168  Proto* f=luaF_newproto(S->L);
 169  setptvalue2s(S->L,S->L->top,f); incr_top(S->L);
 170  f->linedefined=LoadInt(S);
 171  f->lastlinedefined=LoadInt(S);
 172  f->numparams=LoadByte(S);
 173  f->is_vararg=LoadByte(S);
 174  f->maxstacksize=LoadByte(S);
 175  LoadCode(S,f);
 176  LoadConstants(S,f);
 177  LoadUpvalues(S,f);
 178  LoadDebug(S,f);
 179  S->L->top--;
 180  return f;
 181 }
 182
 183 /* the code below must be consistent with the code in luaU_header */
 184 #define N0      LUAC_HEADERSIZE
 185 #define N1      (sizeof(LUA_SIGNATURE)-sizeof(char))
 186 #define N2      N1+2
 187 #define N3      N2+6
 188
 189 static void LoadHeader(LoadState* S)
 190 {
 191  lu_byte h[LUAC_HEADERSIZE];
 192  lu_byte s[LUAC_HEADERSIZE];
 193  luaU_header(h);
 194  memcpy(s,h,sizeof(char));                      /* first char already read */
 195  LoadBlock(S,s+sizeof(char),LUAC_HEADERSIZE-sizeof(char));
 196  if (memcmp(h,s,N0)==0) return;
 197  if (memcmp(h,s,N1)!=0) error(S,"not a");
 198  if (memcmp(h,s,N2)!=0) error(S,"version mismatch in");
 199  if (memcmp(h,s,N3)!=0) error(S,"incompatible"); else error(S,"corrupted");
 200 }
 201
 202 /*
 203 ** load precompiled chunk
 204 */
 205 Proto* luaU_undump (lua_State* L, ZIO* Z, Mbuffer* buff, const char* name)
 206 {
 207  LoadState S;
 208  if (*name=='@' || *name=='=')
 209   S.name=name+1;
 210  else if (*name==LUA_SIGNATURE[0])
 211   S.name="binary string";
 212  else
 213   S.name=name;
 214  S.L=L;
 215  S.Z=Z;
 216  S.b=buff;
 217  LoadHeader(&S);
 218  return luai_verifycode(L,buff,LoadFunction(&S));
 219 }
 220
 221 #define MYINT(s)        (s[0]-'0')
 222 #define VERSION         MYINT(LUA_VERSION_MAJOR)*16+MYINT(LUA_VERSION_MINOR)
 223 #define FORMAT          0               /* this is the official format */
 224
 225 /*
 226 * make header for precompiled chunks
 227 * if you change the code below be sure to update LoadHeader and FORMAT above
 228 * and LUAC_HEADERSIZE in lundump.h
 229 */
 230 void luaU_header (lu_byte* h)
 231 {
 232  int x=1;
 233  memcpy(h,LUA_SIGNATURE,sizeof(LUA_SIGNATURE)-sizeof(char));
 234  h+=sizeof(LUA_SIGNATURE)-sizeof(char);
 235  *h++=cast_byte(VERSION);
 236  *h++=cast_byte(FORMAT);
 237  *h++=cast_byte(*(char*)&x);                    /* endianness */
 238  *h++=cast_byte(sizeof(int));
 239  *h++=cast_byte(sizeof(size_t));
 240  *h++=cast_byte(sizeof(Instruction));
 241  *h++=cast_byte(sizeof(lua_Number));
 242  *h++=cast_byte(((lua_Number)0.5)==0);          /* is lua_Number integral? */
 243  memcpy(h,LUAC_TAIL,sizeof(LUAC_TAIL)-sizeof(char));
 244 }