commit be8445d7e4b6122620c428877b51a27d464253d5
parent 3d296304ef14ac9a6d1fa9357541ddd9bb54722f
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 10 Jul 2019 14:58:04 -0300
Details
In the generic for loop, it is simpler for OP_TFORLOOP to use the
same 'ra' as OP_TFORCALL. Moreover, the internal names of the loop
temporaries "(for ...)" don't need to leak internal details (even
because the numerical for loop doesn't have a fixed role for each of
its temporaries).
Diffstat:
3 files changed, 13 insertions(+), 13 deletions(-)
diff --git a/lparser.c b/lparser.c
@@ -1527,7 +1527,6 @@ static void forbody (LexState *ls, int base, int line, int nvars, int isgen) {
if (isgen) { /* generic for? */
luaK_codeABC(fs, OP_TFORCALL, base, 0, nvars);
luaK_fixline(fs, line);
- base += 2; /* base for 'OP_TFORLOOP' (skips function and state) */
}
endfor = luaK_codeABx(fs, forloop[isgen], base, 0);
fixforjump(fs, endfor, prep + 1, 1);
@@ -1539,9 +1538,9 @@ static void fornum (LexState *ls, TString *varname, int line) {
/* fornum -> NAME = exp,exp[,exp] forbody */
FuncState *fs = ls->fs;
int base = fs->freereg;
- new_localvarliteral(ls, "(for index)");
- new_localvarliteral(ls, "(for limit)");
- new_localvarliteral(ls, "(for step)");
+ new_localvarliteral(ls, "(for state)");
+ new_localvarliteral(ls, "(for state)");
+ new_localvarliteral(ls, "(for state)");
new_localvar(ls, varname);
checknext(ls, '=');
exp1(ls); /* initial value */
@@ -1566,10 +1565,10 @@ static void forlist (LexState *ls, TString *indexname) {
int line;
int base = fs->freereg;
/* create control variables */
- new_localvarliteral(ls, "(for generator)");
new_localvarliteral(ls, "(for state)");
- new_localvarliteral(ls, "(for control)");
- new_localvarliteral(ls, "(for toclose)");
+ new_localvarliteral(ls, "(for state)");
+ new_localvarliteral(ls, "(for state)");
+ new_localvarliteral(ls, "(for state)");
/* create declared variables */
new_localvar(ls, indexname);
while (testnext(ls, ',')) {
diff --git a/lvm.c b/lvm.c
@@ -1746,14 +1746,13 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
Protect(luaD_call(L, ra + 4, GETARG_C(i))); /* do the call */
updatestack(ci); /* stack may have changed */
i = *(pc++); /* go to next instruction */
- ra += 2; /* adjust for next instruction */
lua_assert(GET_OPCODE(i) == OP_TFORLOOP && ra == RA(i));
goto l_tforloop;
}
vmcase(OP_TFORLOOP) {
l_tforloop:
- if (!ttisnil(s2v(ra + 2))) { /* continue loop? */
- setobjs2s(L, ra, ra + 2); /* save control variable */
+ if (!ttisnil(s2v(ra + 4))) { /* continue loop? */
+ setobjs2s(L, ra + 2, ra + 4); /* save control variable */
pc -= GETARG_Bx(i); /* jump back */
}
vmbreak;
diff --git a/testes/files.lua b/testes/files.lua
@@ -427,10 +427,12 @@ do -- testing closing file in line iteration
-- get the to-be-closed variable from a loop
local function gettoclose (lv)
lv = lv + 1
- for i = 1, math.maxinteger do
+ local stvar = 0 -- to-be-closed is 4th state variable in the loop
+ for i = 1, 1000 do
local n, v = debug.getlocal(lv, i)
- if n == "(for toclose)" then
- return v
+ if n == "(for state)" then
+ stvar = stvar + 1
+ if stvar == 4 then return v end
end
end
end