lundump.c
(5.4.6)
/*
** $Id: lundump.c $
** load precompiled Lua chunks
** See Copyright Notice in lua.h
*/
#define lundump_c
#define LUA_CORE
#include "lprefix.h"
#include <limits.h>
#include <string.h>
#include "lua.h"
#include "ldebug.h"
#include "ldo.h"
#include "lfunc.h"
#include "lmem.h"
#include "lobject.h"
#include "lstring.h"
#include "lundump.h"
#include "lzio.h"
#if !defined(luai_verifycode)
#define luai_verifycode(L,f) /* empty */
#endif
typedef struct {
lua_State *L;
ZIO *Z;
const char *name;
} LoadState;
static l_noret error (LoadState *S, const char *why) {
luaO_pushfstring(S->L, "%s: bad binary format (%s)", S->name, why);
luaD_throw(S->L, LUA_ERRSYNTAX);
}
/*
** All high-level loads go through loadVector; you can change it to
** adapt to the endianness of the input
*/
#define loadVector(S,b,n) loadBlock(S,b,(n)*sizeof((b)[0]))
static void loadBlock (LoadState *S, void *b, size_t size) {
if (luaZ_read(S->Z, b, size) != 0)
error(S, "truncated chunk");
}
#define loadVar(S,x) loadVector(S,&x,1)
static lu_byte loadByte (LoadState *S) {
int b = zgetc(S->Z);
if (b == EOZ)
error(S, "truncated chunk");
return cast_byte(b);
}
static size_t loadUnsigned (LoadState *S, size_t limit) {
size_t x = 0;
int b;
limit >>= 7;
do {
b = loadByte(S);
if (x >= limit)
error(S, "integer overflow");
x = (x << 7) | (b & 0x7f);
} while ((b & 0x80) == 0);
return x;
}
static size_t loadSize (LoadState *S) {
return loadUnsigned(S, ~(size_t)0);
}
static int loadInt (LoadState *S) {
return cast_int(loadUnsigned(S, INT_MAX));
}
static lua_Number loadNumber (LoadState *S) {
lua_Number x;
loadVar(S, x);
return x;
}
static lua_Integer loadInteger (LoadState *S) {
lua_Integer x;
loadVar(S, x);
return x;
}
/*
** Load a nullable string into prototype 'p'.
*/
static TString *loadStringN (LoadState *S, Proto *p) {
lua_State *L = S->L;
TString *ts;
size_t size = loadSize(S);
if (size == 0) /* no string? */
return NULL;
else if (--size <= LUAI_MAXSHORTLEN) { /* short string? */
char buff[LUAI_MAXSHORTLEN];
loadVector(S, buff, size); /* load string into buffer */
ts = luaS_newlstr(L, buff, size); /* create string */
}
else { /* long string */
ts = luaS_createlngstrobj(L, size); /* create string */
setsvalue2s(L, L->top.p, ts); /* anchor it ('loadVector' can GC) */
luaD_inctop(L);
loadVector(S, getstr(ts), size); /* load directly in final place */
L->top.p--; /* pop string */
}
luaC_objbarrier(L, p, ts);
return ts;
}
/*
** Load a non-nullable string into prototype 'p'.
*/
static TString *loadString (LoadState *S, Proto *p) {
TString *st = loadStringN(S, p);
if (st == NULL)
error(S, "bad format for constant string");
return st;
}
static void loadCode (LoadState *S, Proto *f) {
int n = loadInt(S);
f->code = luaM_newvectorchecked(S->L, n, Instruction);
f->sizecode = n;
loadVector(S, f->code, n);
}
static void loadFunction(LoadState *S, Proto *f, TString *psource);
static void loadConstants (LoadState *S, Proto *f) {
int i;
int n = loadInt(S);
f->k = luaM_newvectorchecked(S->L, n, TValue);
f->sizek = n;
for (i = 0; i < n; i++)
setnilvalue(&f->k[i]);
for (i = 0; i < n; i++) {
TValue *o = &f->k[i];
int t = loadByte(S);
switch (t) {
case LUA_VNIL:
setnilvalue(o);
break;
case LUA_VFALSE:
setbfvalue(o);
break;
case LUA_VTRUE:
setbtvalue(o);
break;
case LUA_VNUMFLT:
setfltvalue(o, loadNumber(S));
break;
case LUA_VNUMINT:
setivalue(o, loadInteger(S));
break;
case LUA_VSHRSTR:
case LUA_VLNGSTR:
setsvalue2n(S->L, o, loadString(S, f));
break;
default: lua_assert(0);
}
}
}
static void loadProtos (LoadState *S, Proto *f) {
int i;
int n = loadInt(S);
f->p = luaM_newvectorchecked(S->L, n, Proto *);
f->sizep = n;
for (i = 0; i < n; i++)
f->p[i] = NULL;
for (i = 0; i < n; i++) {
f->p[i] = luaF_newproto(S->L);
luaC_objbarrier(S->L, f, f->p[i]);
loadFunction(S, f->p[i], f->source);
}
}
/*
** Load the upvalues for a function. The names must be filled first,
** because the filling of the other fields can raise read errors and
** the creation of the error message can call an emergency collection;
** in that case all prototypes must be consistent for the GC.
*/
static void loadUpvalues (LoadState *S, Proto *f) {
int i, n;
n = loadInt(S);
f->upvalues = luaM_newvectorchecked(S->L, n, Upvaldesc);
f->sizeupvalues = n;
for (i = 0; i < n; i++) /* make array valid for GC */
f->upvalues[i].name = NULL;
for (i = 0; i < n; i++) { /* following calls can raise errors */
f->upvalues[i].instack = loadByte(S);
f->upvalues[i].idx = loadByte(S);
f->upvalues[i].kind = loadByte(S);
}
}
static void loadDebug (LoadState *S, Proto *f) {
int i, n;
n = loadInt(S);
f->lineinfo = luaM_newvectorchecked(S->L, n, ls_byte);
f->sizelineinfo = n;
loadVector(S, f->lineinfo, n);
n = loadInt(S);
f->abslineinfo = luaM_newvectorchecked(S->L, n, AbsLineInfo);
f->sizeabslineinfo = n;
for (i = 0; i < n; i++) {
f->abslineinfo[i].pc = loadInt(S);
f->abslineinfo[i].line = loadInt(S);
}
n = loadInt(S);
f->locvars = luaM_newvectorchecked(S->L, n, LocVar);
f->sizelocvars = n;
for (i = 0; i < n; i++)
f->locvars[i].varname = NULL;
for (i = 0; i < n; i++) {
f->locvars[i].varname = loadStringN(S, f);
f->locvars[i].startpc = loadInt(S);
f->locvars[i].endpc = loadInt(S);
}
n = loadInt(S);
if (n != 0) /* does it have debug information? */
n = f->sizeupvalues; /* must be this many */
for (i = 0; i < n; i++)
f->upvalues[i].name = loadStringN(S, f);
}
static void loadFunction (LoadState *S, Proto *f, TString *psource) {
f->source = loadStringN(S, f);
if (f->source == NULL) /* no source in dump? */
f->source = psource; /* reuse parent's source */
f->linedefined = loadInt(S);
f->lastlinedefined = loadInt(S);
f->numparams = loadByte(S);
f->is_vararg = loadByte(S);
f->maxstacksize = loadByte(S);
loadCode(S, f);
loadConstants(S, f);
loadUpvalues(S, f);
loadProtos(S, f);
loadDebug(S, f);
}
static void checkliteral (LoadState *S, const char *s, const char *msg) {
char buff[sizeof(LUA_SIGNATURE) + sizeof(LUAC_DATA)]; /* larger than both */
size_t len = strlen(s);
loadVector(S, buff, len);
if (memcmp(s, buff, len) != 0)
error(S, msg);
}
static void fchecksize (LoadState *S, size_t size, const char *tname) {
if (loadByte(S) != size)
error(S, luaO_pushfstring(S->L, "%s size mismatch", tname));
}
#define checksize(S,t) fchecksize(S,sizeof(t),#t)
static void checkHeader (LoadState *S) {
/* skip 1st char (already read and checked) */
checkliteral(S, &LUA_SIGNATURE[1], "not a binary chunk");
if (loadByte(S) != LUAC_VERSION)
error(S, "version mismatch");
if (loadByte(S) != LUAC_FORMAT)
error(S, "format mismatch");
checkliteral(S, LUAC_DATA, "corrupted chunk");
checksize(S, Instruction);
checksize(S, lua_Integer);
checksize(S, lua_Number);
if (loadInteger(S) != LUAC_INT)
error(S, "integer format mismatch");
if (loadNumber(S) != LUAC_NUM)
error(S, "float format mismatch");
}
/*
** Load precompiled chunk.
*/
LClosure *luaU_undump(lua_State *L, ZIO *Z, const char *name) {
LoadState S;
LClosure *cl;
if (*name == '@' || *name == '=')
S.name = name + 1;
else if (*name == LUA_SIGNATURE[0])
S.name = "binary string";
else
S.name = name;
S.L = L;
S.Z = Z;
checkHeader(&S);
cl = luaF_newLclosure(L, loadByte(&S));
setclLvalue2s(L, L->top.p, cl);
luaD_inctop(L);
cl->p = luaF_newproto(L);
luaC_objbarrier(L, cl, cl->p);
loadFunction(&S, cl->p, NULL);
lua_assert(cl->nupvalues == cl->p->sizeupvalues);
luai_verifycode(L, cl->p);
return cl;
}