From d7504df2a5d8985f2a8b04f17acff5e324572c39 Mon Sep 17 00:00:00 2001
From: Richard Leach <richardleach@users.noreply.github.com>
Date: Sun, 11 Oct 2020 12:26:27 +0100
Subject: [PATCH] pp_split: no SWITCHSTACK in @ary = split(...) optimisation
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Petr Písař: 607eaf26a99ff76ab48877e68f1d7b005dc51575 ported to 5.32.0.
Signed-off-by: Petr Písař <ppisar@redhat.com>
---
pp.c | 89 +++++++++++++++++++++++++++++-----------------------
t/op/split.t | 23 +++++++++++++-
2 files changed, 72 insertions(+), 40 deletions(-)
diff --git a/pp.c b/pp.c
index df80830..e4863d3 100644
--- a/pp.c
+++ b/pp.c
@@ -5985,6 +5985,7 @@ PP(pp_split)
/* handle @ary = split(...) optimisation */
if (PL_op->op_private & OPpSPLIT_ASSIGN) {
+ realarray = 1;
if (!(PL_op->op_flags & OPf_STACKED)) {
if (PL_op->op_private & OPpSPLIT_LEX) {
if (PL_op->op_private & OPpLVAL_INTRO)
@@ -6007,26 +6008,10 @@ PP(pp_split)
oldsave = PL_savestack_ix;
}
- realarray = 1;
- PUTBACK;
- av_extend(ary,0);
- (void)sv_2mortal(SvREFCNT_inc_simple_NN(sv));
- av_clear(ary);
- SPAGAIN;
if ((mg = SvTIED_mg((const SV *)ary, PERL_MAGIC_tied))) {
PUSHMARK(SP);
XPUSHs(SvTIED_obj(MUTABLE_SV(ary), mg));
- }
- else {
- if (!AvREAL(ary)) {
- I32 i;
- AvREAL_on(ary);
- AvREIFY_off(ary);
- for (i = AvFILLp(ary); i >= 0; i--)
- AvARRAY(ary)[i] = &PL_sv_undef; /* don't free mere refs */
- }
- /* temporarily switch stacks */
- SAVESWITCHSTACK(PL_curstack, ary);
+ } else {
make_mortal = 0;
}
}
@@ -6358,29 +6343,56 @@ PP(pp_split)
LEAVE_SCOPE(oldsave); /* may undo an earlier SWITCHSTACK */
SPAGAIN;
if (realarray) {
- if (!mg) {
- if (SvSMAGICAL(ary)) {
- PUTBACK;
+ if (!mg) {
+ PUTBACK;
+ if(AvREAL(ary)) {
+ if (av_count(ary) > 0)
+ av_clear(ary);
+ } else {
+ AvREAL_on(ary);
+ AvREIFY_off(ary);
+
+ if (AvMAX(ary) > -1) {
+ /* don't free mere refs */
+ Zero(AvARRAY(ary), AvMAX(ary), SV*);
+ }
+ }
+ if(AvMAX(ary) < iters)
+ av_extend(ary,iters);
+ SPAGAIN;
+
+ /* Need to copy the SV*s from the stack into ary */
+ Copy(SP + 1 - iters, AvARRAY(ary), iters, SV*);
+ AvFILLp(ary) = iters - 1;
+
+ if (SvSMAGICAL(ary)) {
+ PUTBACK;
mg_set(MUTABLE_SV(ary));
SPAGAIN;
- }
- if (gimme == G_ARRAY) {
- EXTEND(SP, iters);
- Copy(AvARRAY(ary), SP + 1, iters, SV*);
- SP += iters;
- RETURN;
- }
+ }
+
+ if (gimme != G_ARRAY) {
+ /* SP points to the final SV* pushed to the stack. But the SV* */
+ /* are not going to be used from the stack. Point SP to below */
+ /* the first of these SV*. */
+ SP -= iters;
+ PUTBACK;
+ }
}
else {
- PUTBACK;
- ENTER_with_name("call_PUSH");
- call_sv(SV_CONST(PUSH),G_SCALAR|G_DISCARD|G_METHOD_NAMED);
- LEAVE_with_name("call_PUSH");
- SPAGAIN;
+ PUTBACK;
+ av_extend(ary,iters);
+ av_clear(ary);
+
+ ENTER_with_name("call_PUSH");
+ call_sv(SV_CONST(PUSH),G_SCALAR|G_DISCARD|G_METHOD_NAMED);
+ LEAVE_with_name("call_PUSH");
+ SPAGAIN;
+
if (gimme == G_ARRAY) {
SSize_t i;
/* EXTEND should not be needed - we just popped them */
- EXTEND(SP, iters);
+ EXTEND_SKIP(SP, iters);
for (i=0; i < iters; i++) {
SV **svp = av_fetch(ary, i, FALSE);
PUSHs((svp) ? *svp : &PL_sv_undef);
@@ -6389,13 +6401,12 @@ PP(pp_split)
}
}
}
- else {
- if (gimme == G_ARRAY)
- RETURN;
- }
- GETTARGET;
- XPUSHi(iters);
+ if (gimme != G_ARRAY) {
+ GETTARGET;
+ XPUSHi(iters);
+ }
+
RETURN;
}
diff --git a/t/op/split.t b/t/op/split.t
index 14f9158..7f37512 100644
--- a/t/op/split.t
+++ b/t/op/split.t
@@ -7,7 +7,7 @@ BEGIN {
set_up_inc('../lib');
}
-plan tests => 176;
+plan tests => 182;
$FS = ':';
@@ -648,6 +648,19 @@ is "@a", '1 2 3', 'assignment to split-to-array (stacked)';
is (+@a, 0, "empty utf8 string");
}
+# correct stack adjustments (gh#18232)
+{
+ sub foo { return @_ }
+ my @a = foo(1, scalar split " ", "a b");
+ is(join('', @a), "12", "Scalar split to a sub parameter");
+}
+
+{
+ sub foo { return @_ }
+ my @a = foo(1, scalar(@x = split " ", "a b"));
+ is(join('', @a), "12", "Split to @x then use scalar result as a sub parameter");
+}
+
fresh_perl_is(<<'CODE', '', {}, "scalar split stack overflow");
map{int"";split//.0>60for"0000000000000000"}split// for"00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
CODE
@@ -667,3 +680,11 @@ CODE
ok(eq_array(\@result,['a','b']), "Resulting in ('a','b')");
}
}
+
+# check that the (@ary = split) optimisation survives @ary being modified
+
+fresh_perl_is('my @ary; @ary = split(/\w(?{ @ary[1000] = 1 })/, "abc");',
+ '',{},'(@ary = split ...) survives @ary being Renew()ed');
+fresh_perl_is('my @ary; @ary = split(/\w(?{ undef @ary })/, "abc");',
+ '',{},'(@ary = split ...) survives an (undef @ary)');
+
--
2.25.4