lundump.c

   1 /*
   2 ** $Id: lundump.c,v 2.7.1.4 2008/04/04 19:51:41 roberto Exp $
   3 ** load precompiled Lua chunks
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7 #if 0
   8 #include <string.h>
   9 #endif
  10
  11 #define lundump_c
  12 #define LUA_CORE
  13
  14 #include "lua.h"
  15
  16 #include "ldebug.h"
  17 #include "ldo.h"
  18 #include "lfunc.h"
  19 #include "lmem.h"
  20 #include "lobject.h"
  21 #include "lstring.h"
  22 #include "lundump.h"
  23 #include "lzio.h"
  24
  25 typedef struct {
  26  lua_State* L;
  27  ZIO* Z;
  28  Mbuffer* b;
  29  const char* name;
  30 } LoadState;
  31
  32 #ifdef LUAC_TRUST_BINARIES
  33 #define IF(c,s)
  34 #define error(S,s)
  35 #else
  36 #define IF(c,s)         if (c) error(S,s)
  37
  38 static void error(LoadState* S, const char* why)
  39 {
  40  luaO_pushfstring(S->L,"%s: %s in precompiled chunk",S->name,why);
  41  luaD_throw(S->L,LUA_ERRSYNTAX);
  42 }
  43 #endif
  44
  45 #define LoadMem(S,b,n,size)     LoadBlock(S,b,(n)*(size))
  46 #define LoadByte(S)             (lu_byte)LoadChar(S)
  47 #define LoadVar(S,x)            LoadMem(S,&x,1,sizeof(x))
  48 #define LoadVector(S,b,n,size)  LoadMem(S,b,n,size)
  49
  50 static void LoadBlock(LoadState* S, void* b, size_t size)
  51 {
  52  size_t r=luaZ_read(S->Z,b,size);
  53  IF (r!=0, "unexpected end");
  54 }
  55
  56 static int LoadChar(LoadState* S)
  57 {
  58  char x;
  59  LoadVar(S,x);
  60  return x;
  61 }
  62
  63 static int LoadInt(LoadState* S)
  64 {
  65  int x;
  66  LoadVar(S,x);
  67  IF (x<0, "bad integer");
  68  return x;
  69 }
  70
  71 static lua_Number LoadNumber(LoadState* S)
  72 {
  73  lua_Number x;
  74  LoadVar(S,x);
  75  return x;
  76 }
  77
  78 static TString* LoadString(LoadState* S)
  79 {
  80  size_t size;
  81  LoadVar(S,size);
  82  if (size==0)
  83   return NULL;
  84  else
  85  {
  86   char* s=luaZ_openspace(S->L,S->b,size);
  87   LoadBlock(S,s,size);
  88   return luaS_newlstr(S->L,s,size-1);           /* remove trailing '\0' */
  89  }
  90 }
  91
  92 static void LoadCode(LoadState* S, Proto* f)
  93 {
  94  int n=LoadInt(S);
  95  f->code=luaM_newvector(S->L,n,Instruction);
  96  f->sizecode=n;
  97  LoadVector(S,f->code,n,sizeof(Instruction));
  98 }
  99
 100 static Proto* LoadFunction(LoadState* S, TString* p);
 101
 102 static void LoadConstants(LoadState* S, Proto* f)
 103 {
 104  int i,n;
 105  n=LoadInt(S);
 106  f->k=luaM_newvector(S->L,n,TValue);
 107  f->sizek=n;
 108  for (i=0; i<n; i++) setnilvalue(&f->k[i]);
 109  for (i=0; i<n; i++)
 110  {
 111   TValue* o=&f->k[i];
 112   int t=LoadChar(S);
 113   switch (t)
 114   {
 115    case LUA_TNIL:
 116         setnilvalue(o);
 117         break;
 118    case LUA_TBOOLEAN:
 119         setbvalue(o,LoadChar(S)!=0);
 120         break;
 121    case LUA_TNUMBER:
 122         setnvalue(o,LoadNumber(S));
 123         break;
 124    case LUA_TSTRING:
 125         setsvalue2n(S->L,o,LoadString(S));
 126         break;
 127    default:
 128         error(S,"bad constant");
 129         break;
 130   }
 131  }
 132  n=LoadInt(S);
 133  f->p=luaM_newvector(S->L,n,Proto*);
 134  f->sizep=n;
 135  for (i=0; i<n; i++) f->p[i]=NULL;
 136  for (i=0; i<n; i++) f->p[i]=LoadFunction(S,f->source);
 137 }
 138
 139 static void LoadDebug(LoadState* S, Proto* f)
 140 {
 141  int i,n;
 142  n=LoadInt(S);
 143  f->lineinfo=luaM_newvector(S->L,n,int);
 144  f->sizelineinfo=n;
 145  LoadVector(S,f->lineinfo,n,sizeof(int));
 146  n=LoadInt(S);
 147  f->locvars=luaM_newvector(S->L,n,LocVar);
 148  f->sizelocvars=n;
 149  for (i=0; i<n; i++) f->locvars[i].varname=NULL;
 150  for (i=0; i<n; i++)
 151  {
 152   f->locvars[i].varname=LoadString(S);
 153   f->locvars[i].startpc=LoadInt(S);
 154   f->locvars[i].endpc=LoadInt(S);
 155  }
 156  n=LoadInt(S);
 157  f->upvalues=luaM_newvector(S->L,n,TString*);
 158  f->sizeupvalues=n;
 159  for (i=0; i<n; i++) f->upvalues[i]=NULL;
 160  for (i=0; i<n; i++) f->upvalues[i]=LoadString(S);
 161 }
 162
 163 static Proto* LoadFunction(LoadState* S, TString* p)
 164 {
 165  Proto* f;
 166  if (++S->L->nCcalls > LUAI_MAXCCALLS) error(S,"code too deep");
 167  f=luaF_newproto(S->L);
 168  setptvalue2s(S->L,S->L->top,f); incr_top(S->L);
 169  f->source=LoadString(S); if (f->source==NULL) f->source=p;
 170  f->linedefined=LoadInt(S);
 171  f->lastlinedefined=LoadInt(S);
 172  f->nups=LoadByte(S);
 173  f->numparams=LoadByte(S);
 174  f->is_vararg=LoadByte(S);
 175  f->maxstacksize=LoadByte(S);
 176  LoadCode(S,f);
 177  LoadConstants(S,f);
 178  LoadDebug(S,f);
 179  IF (!luaG_checkcode(f), "bad code");
 180  S->L->top--;
 181  S->L->nCcalls--;
 182  return f;
 183 }
 184
 185 static void LoadHeader(LoadState* S)
 186 {
 187  char h[LUAC_HEADERSIZE];
 188  char s[LUAC_HEADERSIZE];
 189  luaU_header(h);
 190  LoadBlock(S,s,LUAC_HEADERSIZE);
 191  IF (memcmp(h,s,LUAC_HEADERSIZE)!=0, "bad header");
 192 }
 193
 194 /*
 195 ** load precompiled chunk
 196 */
 197 Proto* luaU_undump (lua_State* L, ZIO* Z, Mbuffer* buff, const char* name)
 198 {
 199  LoadState S;
 200  if (*name=='@' || *name=='=')
 201   S.name=name+1;
 202  else if (*name==LUA_SIGNATURE[0])
 203   S.name="binary string";
 204  else
 205   S.name=name;
 206  S.L=L;
 207  S.Z=Z;
 208  S.b=buff;
 209  LoadHeader(&S);
 210  return LoadFunction(&S,luaS_newliteral(L,"=?"));
 211 }
 212
 213 /*
 214 * make header
 215 */
 216 void luaU_header (char* h)
 217 {
 218  int x=1;
 219  memcpy(h,LUA_SIGNATURE,sizeof(LUA_SIGNATURE)-1);
 220  h+=sizeof(LUA_SIGNATURE)-1;
 221  *h++=(char)LUAC_VERSION;
 222  *h++=(char)LUAC_FORMAT;
 223  *h++=(char)*(char*)&x;                         /* endianness */
 224  *h++=(char)sizeof(int);
 225  *h++=(char)sizeof(size_t);
 226  *h++=(char)sizeof(Instruction);
 227  *h++=(char)sizeof(lua_Number);
 228  *h++=(char)(((lua_Number)0.5)==0);             /* is lua_Number integral? */
 229 }