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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 
error(LoadState * S,const char * why)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 
LoadBlock(LoadState * S,void * b,size_t size)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 
LoadChar(LoadState * S)50 static int LoadChar(LoadState* S)
51 {
52  char x;
53  LoadVar(S,x);
54  return x;
55 }
56 
LoadInt(LoadState * S)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 
LoadNumber(LoadState * S)65 static lua_Number LoadNumber(LoadState* S)
66 {
67  lua_Number x;
68  LoadVar(S,x);
69  return x;
70 }
71 
LoadString(LoadState * S)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 
LoadCode(LoadState * S,Proto * f)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 
LoadConstants(LoadState * S,Proto * f)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 
LoadUpvalues(LoadState * S,Proto * f)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 
LoadDebug(LoadState * S,Proto * f)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 
LoadFunction(LoadState * S,Proto * f)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 
LoadHeader(LoadState * S)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 */
luaU_undump(lua_State * L,ZIO * Z,Mbuffer * buff,const char * name)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 */
luaU_header(lu_byte * h)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