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first version of _ENV; no more global variables

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This commit is contained in:
Roberto Ierusalimschy
2010-03-12 16:14:06 -03:00
parent f292760f12
commit 25c557ec63
12 changed files with 52 additions and 124 deletions
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47
lparser.c
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@@ -1,5 +1,5 @@
/*
** $Id: lparser.c,v 2.77 2010/03/04 18:12:57 roberto Exp roberto $
** $Id: lparser.c,v 2.78 2010/03/08 16:55:52 roberto Exp roberto $
** Lua Parser
** See Copyright Notice in lua.h
*/
@@ -259,7 +259,7 @@ static void markupval (FuncState *fs, int level) {
*/
static int singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
if (fs == NULL) /* no more levels? */
return VGLOBAL; /* default is global variable */
return VVOID; /* default is global */
else {
int v = searchvar(fs, n); /* look up locals at current level */
if (v >= 0) { /* found? */
@@ -271,8 +271,8 @@ static int singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
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 */
if (singlevaraux(fs->prev, n, var, 0) == VVOID) /* try upper levels */
return VVOID; /* not found; is a global */
/* else was LOCAL or UPVAL */
idx = newupvalue(fs, n, var); /* will be a new upvalue */
}
@@ -286,15 +286,12 @@ static int singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
static void singlevar (LexState *ls, expdesc *var) {
TString *varname = str_checkname(ls);
FuncState *fs = ls->fs;
if (singlevaraux(fs, varname, var, 1) == VGLOBAL) {
if (fs->envreg == NO_REG) /* regular global? */
init_exp(var, VGLOBAL, luaK_stringK(fs, varname));
else { /* "globals" are in current lexical environment */
expdesc key;
init_exp(var, VLOCAL, fs->envreg); /* current environment */
codestring(ls, &key, varname); /* key is variable name */
luaK_indexed(fs, var, &key); /* env[varname] */
}
if (singlevaraux(fs, varname, var, 1) == VVOID) { /* global name? */
expdesc key;
singlevaraux(fs, ls->envn, var, 1); /* get _ENV variable */
lua_assert(var->k == VLOCAL || var->k == VUPVAL);
codestring(ls, &key, varname); /* key is variable name */
luaK_indexed(fs, var, &key); /* env[varname] */
}
}
@@ -363,7 +360,6 @@ static void pushclosure (LexState *ls, Proto *clp, expdesc *v) {
while (oldsize < f->sizep) f->p[oldsize++] = NULL;
f->p[fs->np++] = clp;
/* initial environment for new function is current lexical environment */
clp->envreg = fs->envreg;
luaC_objbarrier(ls->L, f, clp);
init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np-1));
}
@@ -386,7 +382,6 @@ static void open_func (LexState *ls, FuncState *fs) {
fs->nlocvars = 0;
fs->nactvar = 0;
fs->firstlocal = ls->varl->nactvar;
fs->envreg = NO_REG;
fs->bl = NULL;
f = luaF_newproto(L);
fs->f = f;
@@ -1304,24 +1299,6 @@ static void funcstat (LexState *ls, int line) {
}
static void instat (LexState *ls, int line) {
/* instat -> IN exp DO block END */
FuncState *fs = ls->fs;
int oldenv = fs->envreg; /* save current environment */
BlockCnt bl;
luaX_next(ls); /* skip IN */
enterblock(fs, &bl, 0); /* scope for environment variable */
new_localvarliteral(ls, "(environment)");
fs->envreg = exp1(ls); /* new environment */
adjustlocalvars(ls, 1);
checknext(ls, TK_DO);
block(ls);
leaveblock(fs);
check_match(ls, TK_END, TK_IN, line);
fs->envreg = oldenv; /* restore outer environment */
}
static void exprstat (LexState *ls) {
/* stat -> func | assignment */
FuncState *fs = ls->fs;
@@ -1386,10 +1363,6 @@ static int statement (LexState *ls) {
check_match(ls, TK_END, TK_DO, line);
return 0;
}
case TK_IN: {
instat(ls, line);
return 0;
}
case TK_FOR: { /* stat -> forstat */
forstat(ls, line);
return 0;