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bug: scope of generic for variables is not sound

v5-2
Roberto Ierusalimschy 22 years ago
parent
commit
cc4a22ebe2
  1. 5
      bugs
  2. 52
      lparser.c
  3. 25
      lvm.c

5
bugs

@ -298,3 +298,8 @@ Fri Aug 30 13:49:14 EST 2002
>> userdata may not be cleared properly
(by Roberto; since 5.0a)
** lparser.c
Fri Dec 6 17:06:40 UTC 2002
>> scope of generic for variables is not sound
(by Gavin Wraith; since 5.0a)

52
lparser.c

@ -1,5 +1,5 @@
/*
** $Id: lparser.c,v 1.199 2002/11/22 16:42:53 roberto Exp roberto $
** $Id: lparser.c,v 1.200 2002/12/04 17:38:31 roberto Exp roberto $
** Lua Parser
** See Copyright Notice in lua.h
*/
@ -303,8 +303,8 @@ static void pushclosure (LexState *ls, FuncState *func, expdesc *v) {
f->p[fs->np++] = func->f;
init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np-1));
for (i=0; i<func->f->nupvalues; i++) {
luaK_exp2nextreg(fs, &func->upvalues[i]);
fs->freereg--; /* CLOSURE will use these values */
OpCode o = (func->upvalues[i].k == VLOCAL) ? OP_MOVE : OP_GETUPVAL;
luaK_codeABC(fs, o, 0, func->upvalues[i].info, 0);
}
}
@ -1014,10 +1014,27 @@ static int exp1 (LexState *ls) {
}
static void forbody (LexState *ls, int base, int line, int nvars, int isnum) {
BlockCnt bl;
FuncState *fs = ls->fs;
int prep, endfor;
adjustlocalvars(ls, nvars); /* scope for all variables */
check(ls, TK_DO);
enterblock(fs, &bl, 1); /* loop block */
prep = luaK_getlabel(fs);
block(ls);
luaK_patchtohere(fs, prep-1);
endfor = (isnum) ? luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP) :
luaK_codeABC(fs, OP_TFORLOOP, base, 0, nvars - 3);
luaK_fixline(fs, line); /* pretend that `OP_FOR' starts the loop */
luaK_patchlist(fs, (isnum) ? endfor : luaK_jump(fs), prep);
leaveblock(fs);
}
static void fornum (LexState *ls, TString *varname, int line) {
/* fornum -> NAME = exp1,exp1[,exp1] DO body */
FuncState *fs = ls->fs;
int prep, endfor;
int base = fs->freereg;
new_localvar(ls, varname, 0);
new_localvarstr(ls, "(for limit)", 1);
@ -1032,16 +1049,9 @@ static void fornum (LexState *ls, TString *varname, int line) {
luaK_codeABx(fs, OP_LOADK, fs->freereg, luaK_numberK(fs, 1));
luaK_reserveregs(fs, 1);
}
adjustlocalvars(ls, 3); /* scope for control variables */
luaK_codeABC(fs, OP_SUB, fs->freereg - 3, fs->freereg - 3, fs->freereg - 1);
luaK_jump(fs);
prep = luaK_getlabel(fs);
check(ls, TK_DO);
block(ls);
luaK_patchtohere(fs, prep-1);
endfor = luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP);
luaK_fixline(fs, line); /* pretend that `OP_FOR' starts the loop */
luaK_patchlist(fs, endfor, prep);
forbody(ls, base, line, 3, 1);
}
@ -1049,9 +1059,8 @@ static void forlist (LexState *ls, TString *indexname) {
/* forlist -> NAME {,NAME} IN explist1 DO body */
FuncState *fs = ls->fs;
expdesc e;
int line;
int nvars = 0;
int prep;
int line;
int base = fs->freereg;
new_localvarstr(ls, "(for generator)", nvars++);
new_localvarstr(ls, "(for state)", nvars++);
@ -1060,18 +1069,9 @@ static void forlist (LexState *ls, TString *indexname) {
new_localvar(ls, str_checkname(ls), nvars++);
check(ls, TK_IN);
line = ls->linenumber;
adjust_assign(ls, 3, explist1(ls, &e), &e);
luaK_reserveregs(fs, nvars - 3); /* registers for other variables */
adjust_assign(ls, nvars, explist1(ls, &e), &e);
luaK_codeAsBx(fs, OP_TFORPREP, base, NO_JUMP);
adjustlocalvars(ls, nvars); /* scope for all variables */
check(ls, TK_DO);
prep = luaK_getlabel(fs);
block(ls);
luaK_patchtohere(fs, prep-1);
removevars(fs->ls, fs->nactvar - nvars); /* deactivate locals for next op. */
luaK_codeABC(fs, OP_TFORLOOP, base, 0, nvars - 3);
luaK_fixline(fs, line); /* pretend that `OP_FOR' starts the loop */
luaK_patchlist(fs, luaK_jump(fs), prep);
forbody(ls, base, line, nvars, 0);
}
@ -1080,7 +1080,7 @@ static void forstat (LexState *ls, int line) {
FuncState *fs = ls->fs;
TString *varname;
BlockCnt bl;
enterblock(fs, &bl, 1);
enterblock(fs, &bl, 0); /* block to control variable scope */
next(ls); /* skip `for' */
varname = str_checkname(ls); /* first variable name */
switch (ls->t.token) {

25
lvm.c

@ -1,5 +1,5 @@
/*
** $Id: lvm.c,v 1.270 2002/11/25 17:47:13 roberto Exp roberto $
** $Id: lvm.c,v 1.271 2002/12/04 17:38:31 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@ -671,14 +671,23 @@ StkId luaV_execute (lua_State *L) {
break;
}
case OP_TFORLOOP: {
setobjs2s(ra+4, ra+2);
setobjs2s(ra+3, ra+1);
setobjs2s(ra+2, ra);
L->top = ra+5;
luaD_call(L, ra+2, GETARG_C(i) + 1);
int nvar = GETARG_C(i) + 1;
StkId cb = ra + nvar + 2; /* call base */
setobjs2s(cb, ra);
setobjs2s(cb+1, ra+1);
setobjs2s(cb+2, ra+2);
L->top = cb+3; /* func. + 2 args (state and index) */
luaD_call(L, cb, nvar);
L->top = L->ci->top;
if (ttisnil(XRA(i)+2)) pc++; /* skip jump (break loop) */
else dojump(pc, GETARG_sBx(*pc) + 1); /* else jump back */
ra = XRA(i); /* call may change stack */
cb = ra + nvar + 2;
if (ttisnil(cb)) /* break loop? */
pc++; /* skip jump (break loop) */
else {
while (nvar--) /* move results to proper positions */
setobjs2s(ra+2+nvar, cb+nvar);
dojump(pc, GETARG_sBx(*pc) + 1); /* jump back */
}
break;
}
case OP_TFORPREP: { /* for compatibility only */

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