A patch for _ENV support
- From: 云风 <cloudwu@xxxxxxxxx>
- To: luajit@xxxxxxxxxxxxx
- Date: Thu, 25 Oct 2012 15:06:55 +0800
It looks like that Mike dislike _ENV ;) But I really need it to
compatible my lua 5.2 code in luajit 2.0 .
So I make a patch to support it. I guess someone would need it , too.
Here it is:
diff --git a/src/lib_base.c b/src/lib_base.c
index 568216e..b58a5a4 100644
--- a/src/lib_base.c
+++ b/src/lib_base.c
@@ -363,6 +363,10 @@ static int load_aux(lua_State *L, int status, int envarg)
GCtab *t = tabV(L->base+envarg-1);
setgcref(fn->c.env, obj2gco(t));
lj_gc_objbarrier(L, fn, t);
+ if (LJ_52) {
+ lua_pushvalue(L, envarg);
+ lua_setupvalue(L, -2, 1);
+ }
}
return 1;
} else {
diff --git a/src/lj_lex.c b/src/lj_lex.c
index b54d2a2..59b2b84 100644
--- a/src/lj_lex.c
+++ b/src/lj_lex.c
@@ -381,6 +381,7 @@ int lj_lex_setup(lua_State *L, LexState *ls)
ls->lookahead = TK_eof; /* No look-ahead token. */
ls->linenumber = 1;
ls->lastline = 1;
+ ls->env = NULL;
lj_str_resizebuf(ls->L, &ls->sb, LJ_MIN_SBUF);
next(ls); /* Read-ahead first char. */
if (ls->current == 0xef && ls->n >= 2 && char2int(ls->p[0]) == 0xbb &&
diff --git a/src/lj_lex.h b/src/lj_lex.h
index d16461a..37c15eb 100644
--- a/src/lj_lex.h
+++ b/src/lj_lex.h
@@ -73,6 +73,7 @@ typedef struct LexState {
BCInsLine *bcstack; /* Stack for bytecode instructions/line numbers. */
MSize sizebcstack; /* Size of bytecode stack. */
uint32_t level; /* Syntactical nesting level. */
+ GCstr *env; /* const _ENV */
} LexState;
LJ_FUNC int lj_lex_setup(lua_State *L, LexState *ls);
diff --git a/src/lj_load.c b/src/lj_load.c
index e30421e..5a389af 100644
--- a/src/lj_load.c
+++ b/src/lj_load.c
@@ -40,6 +40,9 @@ static TValue *cpparser(lua_State *L, lua_CFunction
dummy, void *ud)
}
pt = bc ? lj_bcread(ls) : lj_parse(ls);
fn = lj_func_newL_empty(L, pt, tabref(L->env));
+ if (LJ_52) {
+ settabV(L, uvval(&gcref(fn->l.uvptr[0])->uv), tabref(L->env)); /*
Set env table to upvalue 1 */
+ }
/* Don't combine above/below into one statement. */
setfuncV(L, L->top++, fn);
return NULL;
diff --git a/src/lj_parse.c b/src/lj_parse.c
index 29def7b..2f435a5 100644
--- a/src/lj_parse.c
+++ b/src/lj_parse.c
@@ -1112,6 +1112,12 @@ static MSize var_lookup_(FuncState *fs, GCstr
*name, ExpDesc *e, int first)
fscope_uvmark(fs, reg); /* Scope now has an upvalue. */
return (MSize)(e->u.s.aux = (uint32_t)fs->varmap[reg]);
} else {
+ if (LJ_52 && name == fs->ls->env && fs->prev == NULL) {
+ fscope_uvmark(fs,0);
+ expr_init(e, VUPVAL, 0);
+ e->u.s.aux = 0;
+ return 0;
+ }
MSize vidx = var_lookup_(fs->prev, name, e, 0); /* Var in outer func? */
if ((int32_t)vidx >= 0) { /* Yes, make it an upvalue here. */
e->u.s.info = (uint8_t)var_lookup_uv(fs, vidx, e);
@@ -1128,7 +1134,9 @@ static MSize var_lookup_(FuncState *fs, GCstr
*name, ExpDesc *e, int first)
/* Lookup variable name. */
#define var_lookup(ls, e) \
- var_lookup_((ls)->fs, lex_str(ls), (e), 1)
+ var_lookup_((ls)->fs, lex_str(ls), (e), 1); if (LJ_52 && (e)->k ==
VGLOBAL) var_global_((ls), (e))
+
+static void var_global_(LexState *ls, ExpDesc *e);
/* -- Goto an label handling ---------------------------------------------- */
@@ -1687,6 +1695,18 @@ static void expr_index(FuncState *fs, ExpDesc
*t, ExpDesc *e)
t->u.s.aux = expr_toanyreg(fs, e); /* 0..255: register */
}
+/* Convert global to _ENV index. */
+static void var_global_(LexState *ls, ExpDesc *e)
+{
+ FuncState *fs = ls->fs;
+ ExpDesc key;
+ expr_init(&key, VKSTR, 0);
+ key.u.sval = e->u.sval;
+ var_lookup_(fs, ls->env, e, 1);
+ expr_toanyreg(fs, e);
+ expr_index(fs, e, &key);
+}
+
/* Parse index expression with named field. */
static void expr_field(LexState *ls, ExpDesc *v)
{
@@ -2732,6 +2752,16 @@ GCproto *lj_parse(LexState *ls)
fs.bcbase = NULL;
fs.bclim = 0;
fs.flags |= PROTO_VARARG; /* Main chunk is always a vararg func. */
+
+ if (LJ_52) {
+ /* Create upvalue named _ENV */
+ ls->env = lj_parse_keepstr(ls, "_ENV", 4); /* Anchor _ENV
string, 4 is sizeof _ENV */
+ var_new(ls, 0, ls->env);
+ fs.uvmap[0] = 0;
+ fs.uvtmp[0] = 0;
+ fs.nuv = 1;
+ }
+
fscope_begin(&fs, &bl, 0);
bcemit_AD(&fs, BC_FUNCV, 0, 0); /* Placeholder. */
lj_lex_next(ls); /* Read-ahead first token. */
--
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