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when searching for a variable name, look existing upvalues before

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goingg to upper levels
This commit is contained in:
Roberto Ierusalimschy 2010-03-04 15:12:57 -03:00
parent 915a9a912c
commit e560ac4862
1 changed files with 32 additions and 20 deletions
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52
lparser.c
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@ -1,5 +1,5 @@
/*
** $Id: lparser.c,v 2.75 2010/01/06 11:48:02 roberto Exp roberto $
** $Id: lparser.c,v 2.76 2010/02/26 20:40:29 roberto Exp roberto $
** Lua Parser
** See Copyright Notice in lua.h
*/
@ -207,26 +207,26 @@ static void removevars (FuncState *fs, int tolevel) {
}
static int indexupvalue (FuncState *fs, TString *name, expdesc *v) {
static int searchupvalue (FuncState *fs, TString *name) {
int i;
Upvaldesc *up = fs->f->upvalues;
for (i = 0; i < fs->nups; i++) {
if (up[i].name == name) return i;
}
return -1; /* not found */
}
static int newupvalue (FuncState *fs, TString *name, expdesc *v) {
Proto *f = fs->f;
int oldsize = f->sizeupvalues;
int instk = (v->k == VLOCAL);
lua_assert(instk || v->k == VUPVAL);
for (i=0; i<fs->nups; i++) {
if (f->upvalues[i].instack == instk && f->upvalues[i].idx == v->u.s.info) {
lua_assert(f->upvalues[i].name == name);
return i;
}
}
/* new one */
checklimit(fs, fs->nups + 1, UCHAR_MAX, "upvalues");
luaM_growvector(fs->L, f->upvalues, fs->nups, f->sizeupvalues,
Upvaldesc, UCHAR_MAX, "upvalues");
while (oldsize < f->sizeupvalues) f->upvalues[oldsize++].name = NULL;
f->upvalues[fs->nups].name = name;
luaC_objbarrier(fs->L, f, name);
f->upvalues[fs->nups].instack = cast_byte(instk);
f->upvalues[fs->nups].instack = (v->k == VLOCAL);
f->upvalues[fs->nups].idx = cast_byte(v->u.s.info);
return fs->nups++;
}
@ -242,6 +242,10 @@ static int searchvar (FuncState *fs, TString *n) {
}
/*
Mark block where variable at given level was defined
(to emit OP_CLOSE later).
*/
static void markupval (FuncState *fs, int level) {
BlockCnt *bl = fs->bl;
while (bl && bl->nactvar > level) bl = bl->previous;
@ -249,22 +253,30 @@ static void markupval (FuncState *fs, int level) {
}
/*
Find variable with given name 'n'. If it is an upvalue, add this
upvalue into all intermediate functions.
*/
static int singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
if (fs == NULL) /* no more levels? */
return VGLOBAL; /* default is global variable */
else {
int v = searchvar(fs, n); /* look up at current level */
if (v >= 0) {
init_exp(var, VLOCAL, v);
int v = searchvar(fs, n); /* look up locals at current level */
if (v >= 0) { /* found? */
init_exp(var, VLOCAL, v); /* variable is local */
if (!base)
markupval(fs, v); /* local will be used as an upval */
return VLOCAL;
}
else { /* not found at current level; try upper one */
if (singlevaraux(fs->prev, n, var, 0) == VGLOBAL)
return VGLOBAL;
var->u.s.info = indexupvalue(fs, n, var); /* else was LOCAL or UPVAL */
var->k = VUPVAL; /* upvalue in this level */
else { /* not found as local at current level; try upvalues */
int idx = searchupvalue(fs, n); /* try existing upvalues */
if (idx < 0) { /* not found? */
if (singlevaraux(fs->prev, n, var, 0) == VGLOBAL) /* try upper levels */
return VGLOBAL; /* not found; is a global */
/* else was LOCAL or UPVAL */
idx = newupvalue(fs, n, var); /* will be a new upvalue */
}
init_exp(var, VUPVAL, idx);
return VUPVAL;
}
}