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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).
This commit is contained in:
Roberto Ierusalimschy 2019-07-10 14:58:31 -03:00
parent 3d296304ef
commit be8445d7e4
3 changed files with 13 additions and 13 deletions
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13
lparser.c
View File

@ -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, ',')) {

5
lvm.c
View File

@ -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;

8
testes/files.lua
View File

@ -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