commit cc4a22ebe28c5d09566facde05840ddf42778eac
parent acf62ddfbe1163f7cc1ab463842fb6a1b6aba8fe
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Fri, 6 Dec 2002 15:08:38 -0200
bug: scope of generic for variables is not sound
Diffstat:
| M | bugs | | | 5 | +++++ |
| M | lparser.c | | | 52 | ++++++++++++++++++++++++++-------------------------- |
| M | lvm.c | | | 25 | +++++++++++++++++-------- |
3 files changed, 48 insertions(+), 34 deletions(-)
diff --git a/bugs b/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)
+
diff --git a/lparser.c b/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) {
diff --git a/lvm.c b/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 */
