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label names must be unique inside a function

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This commit is contained in:
Roberto Ierusalimschy 2011-06-16 13:36:39 -03:00
parent beab626061
commit fdede85419
1 changed files with 27 additions and 12 deletions
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39
lparser.c
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@ -1,5 +1,5 @@
/*
** $Id: lparser.c,v 2.108 2011/04/18 19:48:24 roberto Exp roberto $
** $Id: lparser.c,v 2.109 2011/05/02 17:33:01 roberto Exp roberto $
** Lua Parser
** See Copyright Notice in lua.h
*/
@ -367,7 +367,7 @@ static int findlabel (LexState *ls, int g) {
/* check labels in current block for a match */
for (i = bl->firstlabel; i < dyd->label.n; i++) {
Labeldesc *lb = &dyd->label.arr[i];
if (eqstr(lb->name, gt->name)) { /* correct label? */
if (eqstr(lb->name, gt->name) && lb->pc != -1) { /* correct label? */
if (gt->nactvar > lb->nactvar &&
(bl->upval || dyd->label.n > bl->firstlabel))
luaK_patchclose(ls->fs, gt->pc, lb->nactvar);
@ -411,7 +411,7 @@ static void findgotos (LexState *ls, Labeldesc *lb) {
/*
** "export" pending gotos to outer level, to check them against
** outer labels; if the block being exited has upvalues, and
** the goto exists the scope of any variable (which can be the
** the goto exits the scope of any variable (which can be the
** upvalue), close those variables being exited.
*/
static void movegotosout (FuncState *fs, BlockCnt *bl) {
@ -460,12 +460,18 @@ static void breaklabel (LexState *ls) {
static void undefgoto (LexState *ls, Labeldesc *gt) {
const char *msg = (gt->name->tsv.reserved > 0)
? "<%s> at line %d not inside a loop"
: "label " LUA_QS " (<goto> at line %d) undefined";
: "no visible label " LUA_QS " for <goto> at line %d";
msg = luaO_pushfstring(ls->L, msg, getstr(gt->name), gt->line);
semerror(ls, msg);
}
static void invalidatelabels (Labellist *ll, int level) {
for (; level < ll->n; level++)
ll->arr[level].pc = -1; /* mark label as out of scope */
}
static void leaveblock (FuncState *fs) {
BlockCnt *bl = fs->bl;
LexState *ls = fs->ls;
@ -481,7 +487,7 @@ static void leaveblock (FuncState *fs) {
removevars(fs, bl->nactvar);
lua_assert(bl->nactvar == fs->nactvar);
fs->freereg = fs->nactvar; /* free registers */
ls->dyd->label.n = bl->firstlabel; /* remove local labels */
invalidatelabels(&ls->dyd->label, bl->firstlabel); /* remove local labels */
if (bl->previous) /* inner block? */
movegotosout(fs, bl); /* update pending gotos to outer block */
else if (bl->firstgoto < ls->dyd->gt.n) /* pending gotos in outer block? */
@ -526,6 +532,7 @@ static void open_func (LexState *ls, FuncState *fs, BlockCnt *bl) {
fs->nlocvars = 0;
fs->nactvar = 0;
fs->firstlocal = ls->dyd->actvar.n;
fs->firstlabel = ls->dyd->label.n;
fs->bl = NULL;
f = luaF_newproto(L);
fs->f = f;
@ -548,6 +555,7 @@ static void close_func (LexState *ls) {
Proto *f = fs->f;
luaK_ret(fs, 0, 0); /* final return */
leaveblock(fs);
ls->dyd->label.n = fs->firstlabel; /* remove labels */
luaM_reallocvector(L, f->code, f->sizecode, fs->pc, Instruction);
f->sizecode = fs->pc;
luaM_reallocvector(L, f->lineinfo, f->sizelineinfo, fs->pc, int);
@ -1185,13 +1193,11 @@ static void gotostat (LexState *ls, TString *label, int line) {
}
static void labelstat (LexState *ls, TString *label, int line) {
/* label -> '@' NAME ':' */
FuncState *fs = ls->fs;
Labellist *ll = &ls->dyd->label;
int l, i; /* index of new label being created */
/* check for repeated labels on the same block */
for (i = ls->fs->bl->firstlabel; i < ll->n; i++) {
/* check for repeated labels on the same function */
static void checkrepeated (LexState *ls, FuncState *fs, Labellist *ll,
TString *label) {
int i;
for (i = fs->firstlabel; i < ll->n; i++) {
if (eqstr(label, ll->arr[i].name)) {
const char *msg = luaO_pushfstring(ls->L,
"label " LUA_QS " already defined on line %d",
@ -1199,6 +1205,15 @@ static void labelstat (LexState *ls, TString *label, int line) {
semerror(ls, msg);
}
}
}
static void labelstat (LexState *ls, TString *label, int line) {
/* label -> '@' NAME ':' */
FuncState *fs = ls->fs;
Labellist *ll = &ls->dyd->label;
int l; /* index of new label being created */
checkrepeated(ls, fs, ll, label); /* check for repeated labels */
checknext(ls, ':'); /* skip colon */
/* create new entry for this label */
l = newlabelentry(ls, ll, label, line, fs->pc);