Branch: refs/heads/smoke-me/davem/rc_stack
Home: https://github.com/Perl/perl5
Commit: 9bd72d6fa6f74c2770c18d75782532787818f408
https://github.com/Perl/perl5/commit/9bd72d6fa6f74c2770c18d75782532787818f408
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_ctl.c
M t/op/svleak.t
Log Message:
-----------
fix leaks in new ${^HOOK}{require__*} facility
In the initial implementation, a few temporary SVs ended up with a ref
count one too high.
Commit: e3d7d6aa9a5bd8990b411698ed6b29a70f336d19
https://github.com/Perl/perl5/commit/e3d7d6aa9a5bd8990b411698ed6b29a70f336d19
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M perl.c
M perl.h
Log Message:
-----------
add PERL_RC_STACK define (not yet defined)
This macro turns on stack reference counting.
Add the macro, but commented out for now.
In addition, temporarily define and enable PERL_XXX_TMP_NORC.
This is a temporary transition measure: even in the presence of
PERL_RC_STACK, do not actually modify reference counts yet. So
PERL_RC_STACK will still define all the new static functions and code
behaviour, except for the bits that actually modify reference counts in
ways that assume the stack is reference counted. It allows this branch
to have many commits which incrementally deal with adding support for
PERL_RC_STACK, with each individual commit still working while half of
the core is still not yet "ref count aware".
Commit: 00f00ced624682da70fe6d001fab904257e025b0
https://github.com/Perl/perl5/commit/00f00ced624682da70fe6d001fab904257e025b0
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M lib/Internals.pod
M universal.c
Log Message:
-----------
add Internals::stack_refcounted()
This indicates whether perl has been built with PERL_RC_STACK.
For now this should only be used by core; It's not yet decided whether
CPAN modules have a use case too.
Commit: f8f63437b7ec14459883aa05e6ed9c9ea8caee2d
https://github.com/Perl/perl5/commit/f8f63437b7ec14459883aa05e6ed9c9ea8caee2d
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M ext/Devel-Peek/t/Peek.t
Log Message:
-----------
ext/Devel-Peek/t/Peek.t: fixup top refcount
There are a few 'expected' Dump() output patterns which expect the
refcount of the top-most SV in the tree to be fixed number like
REFCNT = 1
Change all those occurrences to
REFCNT = \d+
or similar, since a reference-counted stack will cause higher values
Commit: 27ee56b6e989a0a402228adcd4c2477e21f08806
https://github.com/Perl/perl5/commit/27ee56b6e989a0a402228adcd4c2477e21f08806
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_ctl.c
M scope.c
Log Message:
-----------
pp_dbstate: skip SAVESTACK_POS()
On PERL_RC_STACK builds, skip the call to SAVESTACK_POS().
I suspect that saving the stack position is no longer
required. It was added in 5.001 by:
NETaa13155: &DB::DB left trash on the stack.
From: Thomas Koenig
Files patched: lib/perl5db.pl pp_ctl.c
The call by pp_dbstate() to &DB::DB left trash on the
stack. It now calls DB in list context, and DB returns
().
but the details of what bug it fixed are long lost to history.
SAVESTACK_POS() doesn't work well with stacks which may be split into
partly reference-counted and partly not halves, so skip it and hope it
doesn't cause any problems.
Also, assert that SAVEt_STACK_POS isn't used anywhere any more.
Commit: 13e5ecd96857d48be27f0fdd03d95e5c34b3d9f1
https://github.com/Perl/perl5/commit/13e5ecd96857d48be27f0fdd03d95e5c34b3d9f1
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_ctl.c
Log Message:
-----------
pp_mapwhile(): null out holes in stack
>From time to time, pp_mapwhile() shifts up any remaining args on the
stack, in order to leave enough space to add the current results to any
accumulated results. This leaves a hole in the stack, which might not be
fully filled until the last iteration. As well as making the output of
perl -Ds confusing, any garbage left in the hole will double-count
towards the reference count of each SV once the stack becomes
reference-counted.
So fill the newly-created hole in the stack with NULL pointers.
Commit: 27b2eb0395dbcb71874095ab0ca1b6d3c01878d1
https://github.com/Perl/perl5/commit/27b2eb0395dbcb71874095ab0ca1b6d3c01878d1
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M av.c
M embed.fnc
M embed.h
M inline.h
M proto.h
Log Message:
-----------
Add av_remove_offset() core-only function
This function abstracts away removing any AvARRAY(av) - AvALLOC(av)
offset from an array (previously added by av_shift()).
Also use Zero() rather than a loop to NULL out any elements in the
offset area.
Commit: 1f23a8dbeb9aacd23b37b3453153939f93686fad
https://github.com/Perl/perl5/commit/1f23a8dbeb9aacd23b37b3453153939f93686fad
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M embed.fnc
M embed.h
M op.c
M perl.c
M pp_ctl.c
M proto.h
Log Message:
-----------
create_eval_scope(): parameterise the stack pos
Rather than always using PL_stack_sp to pass to cx_pushblock(),
allow the caller of create_eval_scope() to specify what stack position
is to be saved.
This will be used shortly to fix a bug.
Commit: e5a0c059ea44ec9c3388c89593ba5fcd5e79d3a5
https://github.com/Perl/perl5/commit/e5a0c059ea44ec9c3388c89593ba5fcd5e79d3a5
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M perl.c
Log Message:
-----------
Perl_call_sv(G_EVAL): set oldsp correctly
call_sv(cv, G_EVAL) pushes a CXt_EVAL context, fakes up an entersub op,
then runs it, letting entersub consume the arguments pushed onto the current
stack frame by call_sv()'s caller.
So the C-level
PUSHMARK():
PUSHs(arg1);
...
PUSHs(argN);
call_sv(cv, G_EVAL);
is about equivalent to the perl-level:
eval { cv($arg1,..$argN) }
Except that in the latter, when the CXt_EVAL is pushed, it is done
*before* any of the arguments have been pushed, so the eval context's
blk_oldsp points to just before the arguments. Conversely in the case of
call_sv(), blk_oldsp gets set to just *after* the arguments.
During an exception, the context stack gets unwound until the CXt_EVAL
is reached, then PL_stack_sp is restored to the blk_oldsp value.
The difference currently makes no real functional difference, as
call_sv() resets PL_stack_sp immediately after an exception anyway, so
the bad just-restored value is discarded. But it does mean that
PL_stack_sp briefly points to junk on the stack. When the stack becomes
reference-counted, this will start to become important. So fix now.
This commit changes it so that call_sv()'s blk_oldsp gets set to just
before the arguments too. It also asserts that the stack was cleared
back to blk_oldsp.
Commit: 2491211277c3337f7bdf7ab63e48b3f73c3f84cf
https://github.com/Perl/perl5/commit/2491211277c3337f7bdf7ab63e48b3f73c3f84cf
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M inline.h
Log Message:
-----------
assert that cxstack[i].oldsp are increasing
The saved stack positions
cxstack[0].oldsp
cxstack[1].oldsp
cxstack[2].oldsp
...
effectively divide the argument stack into a series of stack frames.
This unravels if an earlier oldsp is actually greater than a later one.
It didn't really matter before, but for a reference-counted stack it
becomes a mess when trying to unwind the stack after an exception. So
assert that oldsp never decreases.
This assert found one failure in core, which was fixed by the previous
commit.
Commit: a69c1e3dfa70735b976953c94c111a9ab35495c8
https://github.com/Perl/perl5/commit/a69c1e3dfa70735b976953c94c111a9ab35495c8
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M autodoc.pl
M embed.fnc
M embed.h
M inline.h
M proto.h
Log Message:
-----------
add rpp_foo() refcounted-stack manipulation fns
The various new inline functions like rpp_push_1() are intended to be
(approximate) replacements for the traditional PUSHs(), POPs() etc
macros, except that when compiled under PERL_RC_STACK, they understand
a reference-counted stack.
Except currently they assume the stack is still not reference-counted in
the presence of PERL_XXX_TMP_NORC. This will be turned off in a few
commits' time.
Commit: ff15b2e547232e8758f93d4113487ef8f55e7c13
https://github.com/Perl/perl5/commit/ff15b2e547232e8758f93d4113487ef8f55e7c13
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_hot.c
Log Message:
-----------
use new rpp_is_lone() function
This inline function checks for whether an SV is only referenced
from the stack or temps stack. (Well, it only checks TEMPs currently, but
will shortly handle a ref-counted stack too). In particular it tests for:
SvTEMP(sv) && && SvREFCNT(sv) == 1
This commit uses it in various places to replace where the conditions
are currently written out in full. This will allow those places to still
work correctly when the stack becomes reference-counted.
Commit: 20eed5399f7ac1164dcd7c3cba7dcc418ac282f7
https://github.com/Perl/perl5/commit/20eed5399f7ac1164dcd7c3cba7dcc418ac282f7
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M doop.c
M embed.fnc
M makedef.pl
M pp.c
M pp.h
M pp_ctl.c
M pp_hot.c
M pp_pack.c
M pp_sys.c
M proto.h
Log Message:
-----------
wrap normal non-RC-stack-aware pp functions
In the presence of PERL_RC_STACK, wrap most pp functions with a function
that calls the real pp function with a (non-reference-counted) copy of
the stack arguments. On return, the wrapper bumps up the reference
count of the returned list and, as appropriate, shifts them down the
stack.
This allows a pp function which is not aware of a reference-counted
stack to be called in a reference-counted stack environment.
About 250 such functions are wrappable; the remaining 50 or so need
individual handling and will be dealt with in the following few commits.
This is a temporary band-aid which slows down calls to pp() functions.
It is expected that over time these functions will be unwrapped and
updated to to understand a reference-counted stack. But by temporarily
wrapping them now, it allows perl to be (experimentally) shifted over to
a reference-counted stack without having to review and modify all 30K
lines of pp code first.
(Except currently, the wrapper assumes the stack is still not
reference-counted in the presence of PERL_XXX_TMP_NORC. This will be
turned off in a few commits' time.)
Note also that pp_wrap() is not yet complete. It simulates wrapping by
making a copy of the args on entry to the wrapped function and shifting
any returned values back down. But as well as being temporarily
inhibited from actually modifying reference counts by PERL_XXX_TMP_NORC,
there are extra considerations which will be taken account of by the
"Allow stacks to be reference-counted" commit coming later.
Commit: dd747a0d1a029a3ed3b23dbc2482ca170d05707a
https://github.com/Perl/perl5/commit/dd747a0d1a029a3ed3b23dbc2482ca170d05707a
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_hot.c
Log Message:
-----------
pp_method*: fixup wrapping
The various method ops are sometimes naughty and substitute a different
object at the base of the current stack frame. This is "below"
the area of the stack normally processed by pp_wrap(), so the reference
count adjusting must be done manually.
Commit: 2e0a1cf5bfc08b220ea9e3b271f9d100feec245c
https://github.com/Perl/perl5/commit/2e0a1cf5bfc08b220ea9e3b271f9d100feec245c
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_ctl.c
Log Message:
-----------
make RC-stack-aware: regcomp
Update pp_regcomp() to handle a reference-counted stack environment in
the presence of PERL_RC_STACK.
But in the presence of PERL_XXX_TMP_NORC, don't actually manipulate
reference counts yet. This will be turned off in a few commits' time.
Commit: b9aa958e12d43cd8e4d94a062d8f31a7e436b949
https://github.com/Perl/perl5/commit/b9aa958e12d43cd8e4d94a062d8f31a7e436b949
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M embed.fnc
M makedef.pl
M pp_hot.c
M proto.h
Log Message:
-----------
make RC-stack-aware: entersub
Update pp_entersub() to handle a reference-counted stack environment in
the presence of PERL_RC_STACK.
As well as the expected changes to pp_entersub(), this commit also adds
a function, xs_wrap(), which is similar in concept to pp_wrap(), but
which makes a non-reference-counted copy of the arguments on the stack
before calling any XS function which isn't RC-stack-aware yet (which is
currently all of them).
xs_wrap() will soon be used by pp_goto() too.
In the presence of PERL_XXX_TMP_NORC, don't actually manipulate
reference counts yet. This will be turned off in a few commits' time.
Note also that xs_wrap() is not yet complete. It simulates wrapping by
making a copy of the args on entry to the wrapped function and shifting
any returned values back down. But as well as being temporarily
inhibited from actually modifying reference counts by PERL_XXX_TMP_NORC,
there are extra considerations which will be taken account of by the
"Allow stacks to be reference-counted" commit coming later.
Commit: 6f31eab8189a4b48c570ad1464530fd54f2c93b8
https://github.com/Perl/perl5/commit/6f31eab8189a4b48c570ad1464530fd54f2c93b8
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_ctl.c
M pp_hot.c
Log Message:
-----------
make RC-stack-aware: db/nextstate, unstack
Update pp_dbstate(), pp_nextstate() and pp_unstack() to handle a
reference-counted stack environment in the presence of PERL_RC_STACK.
But in the presence of PERL_XXX_TMP_NORC, don't actually manipulate
reference counts yet. This will be turned off in a few commits' time.
Commit: e17193de7d7df4b131e352956b2b638fc548ed7c
https://github.com/Perl/perl5/commit/e17193de7d7df4b131e352956b2b638fc548ed7c
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_ctl.c
M pp_hot.c
M t/op/grep.t
Log Message:
-----------
make RC-stack-aware: map and grep
Update pp_grepstart(), pp_grepwhile() and pp_mapwhile() to handle a
reference-counted stack environment in the presence of PERL_RC_STACK.
But in the presence of PERL_XXX_TMP_NORC, don't actually manipulate
reference counts yet. This will be turned off in a few commits' time.
Also add some tests to op/grep.t to check for stuff being freed at an
appropriate time (they weren't being at one iteration of this commit).
Commit: a318e4c7121192e7d6f56cb49442bb5fa6372917
https://github.com/Perl/perl5/commit/a318e4c7121192e7d6f56cb49442bb5fa6372917
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_ctl.c
Log Message:
-----------
make RC-stack-aware: enteriter, leaveloop
Update pp_enteriter() and pp_leveloop() to handle a reference-counted
stack environment in the presence of PERL_RC_STACK.
But in the presence of PERL_XXX_TMP_NORC, don't actually manipulate
reference counts yet. This will be turned off in a few commits' time.
Commit: e97974d144639ac0e7d8655286672995489e6c4e
https://github.com/Perl/perl5/commit/e97974d144639ac0e7d8655286672995489e6c4e
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_ctl.c
M pp_hot.c
Log Message:
-----------
make RC-stack-aware: pp_leavefoo()
Update some pp_leavefoo() functions to handle a reference-counted stack
environment in the presence of PERL_RC_STACK.
But in the presence of PERL_XXX_TMP_NORC, don't actually manipulate
reference counts yet. This will be turned off in a few commits' time.
Commit: f0491eeb4b13b8b6dbd96724687d2b9e35944c39
https://github.com/Perl/perl5/commit/f0491eeb4b13b8b6dbd96724687d2b9e35944c39
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_ctl.c
Log Message:
-----------
make RC-stack-aware: last
Update pp_last() to handle a reference-counted stack environment in
the presence of PERL_RC_STACK.
But in the presence of PERL_XXX_TMP_NORC, don't actually manipulate
reference counts yet. This will be turned off in a few commits' time.
Commit: 0a84cd486546ceb9ef442aebc3a45e2bec017b70
https://github.com/Perl/perl5/commit/0a84cd486546ceb9ef442aebc3a45e2bec017b70
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_ctl.c
Log Message:
-----------
make RC-stack-aware: goto
Update pp_goto() to handle a reference-counted stack environment in
the presence of PERL_RC_STACK.
But in the presence of PERL_XXX_TMP_NORC, don't actually manipulate
reference counts yet. This will be turned off in a few commits' time.
Commit: 3c197103a4add33fd14123c05ba9977afac196c8
https://github.com/Perl/perl5/commit/3c197103a4add33fd14123c05ba9977afac196c8
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_ctl.c
Log Message:
-----------
make RC-stack-aware: require,eval
Update pp_entereval() et al to handle a reference-counted stack
environment in the presence of PERL_RC_STACK.
But in the presence of PERL_XXX_TMP_NORC, don't actually manipulate
reference counts yet. This will be turned off in a few commits' time.
Commit: 98de7a9c269ae91ef3b086bc22524935a2e13dd6
https://github.com/Perl/perl5/commit/98de7a9c269ae91ef3b086bc22524935a2e13dd6
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_ctl.c
Log Message:
-----------
make RC-stack-aware: enter/leavegiven etc
Update pp_entergiven() et al to handle a reference-counted stack
environment in the presence of PERL_RC_STACK.
But in the presence of PERL_XXX_TMP_NORC, don't actually manipulate
reference counts yet. This will be turned off in a few commits' time.
Commit: 19595987c4167543e145bdf7da1379fa5ec153e0
https://github.com/Perl/perl5/commit/19595987c4167543e145bdf7da1379fa5ec153e0
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_sys.c
Log Message:
-----------
make RC-stack-aware: enter/leavewrite
Update pp_enterwrite() and pp_leavewrite() to handle a reference-counted
stack environment in the presence of PERL_RC_STACK.
But in the presence of PERL_XXX_TMP_NORC, don't actually manipulate
reference counts yet. This will be turned off in a few commits' time.
Commit: 77dd2f4896077041d8c213a7fbc3b389e5fa988c
https://github.com/Perl/perl5/commit/77dd2f4896077041d8c213a7fbc3b389e5fa988c
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_sort.c
M t/op/sort.t
Log Message:
-----------
make RC-stack-aware: pp_sort()
Update pp_sort() to handle a reference-counted stack environment in
the presence of PERL_RC_STACK.
(But in the presence of PERL_XXX_TMP_NORC, don't actually manipulate
reference counts yet. This will be turned off in a few commits' time.)
In addition to replacing all the POPs type stuff with rpp_foo() inline
function calls, three slight functional changes were done to make this
work.
1) The stack entry pointing to the SV containing the sort function name
is now NULLed out rather than being left on the stack, just after
being freed. It is usually overwritten later on in the process.
2) For an in-place sort (@a = sort @a), the AV is now left on the stack
so that it isn't prematurely freed. This is okay, because...
3) Also for an in-place sort, after the results are stored in @a, the
stack frame is cleared. This is safe because the optimisation is
only ever done in void context. Previously the stack would be be
cleared by the following nextstate op or similar anyway.
Commit: 60610fe26e34374efe39348a2da6bbfe7df7e055
https://github.com/Perl/perl5/commit/60610fe26e34374efe39348a2da6bbfe7df7e055
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_sort.c
Log Message:
-----------
make RC-stack-aware: sort cmp function invokers
Update S_sortcv() etc to handle a reference-counted stack environment in
the presence of PERL_RC_STACK.
These three static functions are used by pp_sort() to invoke a suitable
comparison subroutine.
(But in the presence of PERL_XXX_TMP_NORC, don't actually manipulate
reference counts yet. This will be turned off in a few commits' time.)
Commit: 27e2578575eb728cb36f4d7863fe699c90dd8eeb
https://github.com/Perl/perl5/commit/27e2578575eb728cb36f4d7863fe699c90dd8eeb
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M doio.c
M pp_sys.c
Log Message:
-----------
make RC-stack-aware: stat and filetest ops
Update the pp functions which do stat and filetest operations to handle
a reference-counted stack environment in the presence of PERL_RC_STACK.
But in the presence of PERL_XXX_TMP_NORC, don't actually manipulate
reference counts yet. This will be turned off in a few commits' time.
Commit: 3fc24b91e62e28b37b2f7f9cf91ba5e93c4dcc2b
https://github.com/Perl/perl5/commit/3fc24b91e62e28b37b2f7f9cf91ba5e93c4dcc2b
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M inline.h
M pp.c
Log Message:
-----------
make RC-stack-aware: misc pp() functions
Update the remaining miscellaneous pp() functions to handle a
reference-counted stack environment in the presence of PERL_RC_STACK.
But in the presence of PERL_XXX_TMP_NORC, don't actually manipulate
reference counts yet. This will be turned off in a few commits' time.
Commit: f3ca9a98e7e21d3c6f7ac60c81d9537c1d385008
https://github.com/Perl/perl5/commit/f3ca9a98e7e21d3c6f7ac60c81d9537c1d385008
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M perl.c
Log Message:
-----------
make RC-stack-aware: call_sv() and similar
Update the functions which directly or indirectly call a CV, to handle
a reference-counted stack environment.
Note that call_sv(), eval_pv() etc are slightly unusual in that they can
be called from either a reference-counted or non-RC stack environment,
so must be able to handle either case. This is done mostly by relying on
CALLRUNOPS() to fix things up, but for anything pushed/pulled around
that, by checking rpp_stack_is_rc(): which currently always returns
false, but once ref-counting is enabled in a few commits' time, may
start returning true.
Commit: a129878b58874f0bcd855c5319afe9b2d68683fa
https://github.com/Perl/perl5/commit/a129878b58874f0bcd855c5319afe9b2d68683fa
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M perl.c
Log Message:
-----------
make RC-stack-aware: eval_sv()
Similar to the previous commit which fixed up call_sv() and similar,
the commit updates eval_sv() to handle a reference-counted stack
environment.
Note that these functions are slightly unusual in that they can
be called from either a reference-counted or non-RC stack environment,
so must be able to handle either case. This is done mostly by relying on
CALLRUNOPS() to fix things up, but for anything pushed/pulled around
that, by checking rpp_stack_is_rc(): which currently always returns
false, but once ref-counting is enabled in a few commits' time, may
start returning true.
Commit: 0a6d59abc11ef70bb48c88ba4c98489f4a16e0b3
https://github.com/Perl/perl5/commit/0a6d59abc11ef70bb48c88ba4c98489f4a16e0b3
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_ctl.c
Log Message:
-----------
make RC-stack-aware: defer
The defer keyword saves the address of an optree, which is then
run during leave_scope(). Since that can happen in unpredictable
places (e.g. during a croak), we won't know until runtime where the
stack is currently reference-counted. So handle both cases.
Commit: dfca5de2dc13fbf7f4169387e9a5b1cfe6b17a0d
https://github.com/Perl/perl5/commit/dfca5de2dc13fbf7f4169387e9a5b1cfe6b17a0d
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_hot.c
Log Message:
-----------
make RC-stack-aware: unwrap pp_add()
Remove the temporary wrapper from pp_add() and update it to directly
work in a refcounted-stack environment.
This is mainly a proof of concept to check that all the new rpp_foo()
inline functions and macros are suitable for working with a typical
binary operator.
Commit: edf4998fddef3b8360134411ea59017be1758395
https://github.com/Perl/perl5/commit/edf4998fddef3b8360134411ea59017be1758395
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp.c
Log Message:
-----------
make RC-stack-aware: unwrap pp_not()
Remove the temporary wrapper from pp_not() and update it to directly
work in a refcounted-stack environment.
This is mainly a proof of concept to check that rpp_tryAMAGICun_MG() and
its underlying Perl_try_amagic_un() work ok.
Commit: 2bb2de3c8efb0d8072f71bc77e72f9e0ea1b55e8
https://github.com/Perl/perl5/commit/2bb2de3c8efb0d8072f71bc77e72f9e0ea1b55e8
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M op.c
Log Message:
-----------
make RC-stack-aware: S_fold_constants()
The folded SV it pops off the stack should be treated as
reference counted.
Commit: dadecf8bf706a085c36af3eb4ff8cd2f873f2b7c
https://github.com/Perl/perl5/commit/dadecf8bf706a085c36af3eb4ff8cd2f873f2b7c
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M ext/Devel-Peek/Peek.pm
M ext/Devel-Peek/Peek.xs
Log Message:
-----------
make RC-stack-aware: Devel::Peek::Dump()
This function is implemented as a custom op rather than as a function
call, so it wasn't getting wrapped for reference-count purposes by
either pp_wrap() nor xs_wrap().
This commit makes it directly handle a reference-counted stack.
This was a particularly confusing one, as a failing test in t/op/eval.t
was reduced to
use Devel::Peek;
Dump($@);
eval { die "boo\n"; };
Dump($@);
which showed the ref count of $@ increasing after the eval {}. But it
was actually Dump(), not eval{} which was messing with the ref count.
Commit: 3cb80f0529e9ca34d69717fe52dc296cd3951ff4
https://github.com/Perl/perl5/commit/3cb80f0529e9ca34d69717fe52dc296cd3951ff4
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M sv.c
Log Message:
-----------
make RC-stack-aware: perl_clone()
It has some code that calls out to PACKAGE::CLONE(). Depending on how
the interpreter is being cloned, the code which assembles the args on
the stack for the CLONE() call may be operating on either a
reference-counted stack, or a non-RC one. So handle both cases
Commit: dab621b75ef49e29348107d84b524ccec241e342
https://github.com/Perl/perl5/commit/dab621b75ef49e29348107d84b524ccec241e342
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M gv.c
Log Message:
-----------
make RC-stack-aware: Perl_try_amagic_un() & _bin()
Note that these two functions may be called both from PP functions aware
of a reference-counted stack and from wrapped (non-aware) functions,
hence the RC manipulation is runtime conditional.
Commit: e54d7cab1cfbb649240f35a3ddc8868a221f2baa
https://github.com/Perl/perl5/commit/e54d7cab1cfbb649240f35a3ddc8868a221f2baa
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M dist/threads/threads.xs
Log Message:
-----------
make RC-stack-aware: threads.xs
S_ithread_run() starts running a new top-level perl interpreter, which
will have a ref-counted stack. So treat the stack as ref-counted.
Commit: a5daa733185be42e702b20769b3ed8fab76d2df0
https://github.com/Perl/perl5/commit/a5daa733185be42e702b20769b3ed8fab76d2df0
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M t/cmd/for.t
Log Message:
-----------
make RC-stack-aware: t/cmd/for.t
A test that expects to fail on a non reference-counted stack should no
longer do so if the stack is fully reference-counted
Commit: 9c49f8c80c2cd0e1d2127857d1e3e23eabc4dd8d
https://github.com/Perl/perl5/commit/9c49f8c80c2cd0e1d2127857d1e3e23eabc4dd8d
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M op.c
Log Message:
-----------
make RC-stack-aware: invoking DB::postponed()
Various places in core call DB::postponed(). This all happens in
places where the stack will be reference-counted, so fix the callers.
Commit: d128e6bb4caee5040390253639ffabead3fbb8f5
https://github.com/Perl/perl5/commit/d128e6bb4caee5040390253639ffabead3fbb8f5
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M ext/XS-APItest/APItest.pm
M ext/XS-APItest/APItest.xs
M ext/XS-APItest/t/magic.t
Log Message:
-----------
make RC-stack-aware: ext/XS-APItest/
APItest.xs mainly consists of XS functions - which are not aware of a
ref counted stack - but such functions are called via xs_wrap(), so
that's ok.
However, THX_pp_establish_cleanup() is actually a PP function attached
to an op, rather than an XS function - so it doesn't get automatically
wrapped. Update it to handle a reference-counted stack.
Also, use the standard CALLRUNOPS() macro to call a runops loop rather
than invoking directly; the former will allow a wrapper to be inserted.
Finally, parameterise the expected ref count in t/magic.t, as it will
change if the stack is ref counted.
Commit: a6f6b069bdba54e2074a0b156c1a97db789087ef
https://github.com/Perl/perl5/commit/a6f6b069bdba54e2074a0b156c1a97db789087ef
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M class.c
Log Message:
-----------
make RC-stack-aware: class.c: pp_methstart etc
Commit: eefb192fcdb5b56c93d4f9054efadf0b2f0f421b
https://github.com/Perl/perl5/commit/eefb192fcdb5b56c93d4f9054efadf0b2f0f421b
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M av.c
M inline.h
M pp_hot.c
Log Message:
-----------
make shift(@a) leave old pointer
Generally shifting is done by adjusting the start position of the
array, so that AvALLOC() and AvARRAY() no longer align. Previously if
the array was AvREAL(), perl NULL-ed out the old pointer at the same
time, i.e. doing the equivalent of AvARRAY(av)[-1] = NULL.
This commit changes it so that on PERL_RC_STACK builds, perl instead
keeps the old pointer there on AvREAL() arrays too, even if it now
points to a freed SV; and instead makes av_clear() and av_unshift()
responsible for NULL-ing out the slot only when actually reclaiming any
unused slots between AvALLOC() and AvARRAY().
The reason for this is because of the mechanism whereby @DB::args is
sometimes populated by caller(), as used by Carp.pm to display function
arguments in stack traces etc. For the common idiom of
sub f {
my $self = shift;
....;
}
then previously, since @_ wasn't AvREAL(), the old pointer in @_ to
argument 0 was kept around and thus the hidden pointer value was still
available for caller() to add to @DB::args.
But since the next commit will change @_ to be AvREAL(), this will no
longer work. Thus to keep the ability to debug stack traces etc (via
the awful @DB::args hack), we make shift keep the pointer even for the
AvREAL() case.
Commit: 4f151d7f31f291647e249ffe7b266b1547740e0b
https://github.com/Perl/perl5/commit/4f151d7f31f291647e249ffe7b266b1547740e0b
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M cop.h
M embed.fnc
M embed.h
M inline.h
M pad.c
M pp_ctl.c
M pp_hot.c
M pp_sort.c
M proto.h
M t/op/sub.t
Log Message:
-----------
make @_ AvREAL() on RC-stack
Traditionally, the @_ AV has been marked as AvREAL_off(), but AvREIFY_on().
This commit changes it so that on PERL_RC_STACK builds, @_ is AvREAL().
This will mean that when the stack is ref-counted, the stack frame can
be directly moved to @_ while maintaining the correct ref count for each
argument (in the same way that !AvREAL() worked well with a
non-ref-counted stack).
Note that the stack will not actually be reference-counted for a few
more commits yet. In the meantime, this commit allows for that by
bumping up the reference count of SVs being transferred from the stack
to @_. This extra step will soon be skipped.
Commit: 6ce0b312ed1bb63b79e64862e2397c5e32877833
https://github.com/Perl/perl5/commit/6ce0b312ed1bb63b79e64862e2397c5e32877833
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M cop.h
M embed.fnc
M embed.h
M inline.h
M pp.h
M pp_sort.c
M proto.h
Log Message:
-----------
add switch_argstack(), push/pop_stackinfo() fns
These new inline functions are supposed to be near-identical
replacements for these macros:
PUSHSTACKi(type) push_stackinfo(type)
POPSTACK() pop_stackinfo()
SWITCHSTACK(from,to) switch_argstack(to) // assumes (from == PL_curstack)
except that they don't require dSP to be in scope (they operate on
PL_stack_sp rather than sp) and their names more clearly specify what
sort of stack they manipulate.
The macros are now thin wrappers around the functions. I've kept most of
their uses in core for now as they are still used in places with dSP
present.
Commit: aee32c8dcb563016fdc9bfb53ed9afd6c3192a2c
https://github.com/Perl/perl5/commit/aee32c8dcb563016fdc9bfb53ed9afd6c3192a2c
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M cop.h
M embed.fnc
M embed.h
M inline.h
M perl.c
M pp_sort.c
M proto.h
M scope.c
Log Message:
-----------
allow argument stack to be AvREAL()
Add a _flags() variant of new_stackinfo() which indicates whether the
new stack AV should be created real or not.
Modify the new push_stackinfo() function to have a similar flag.
Then make the backcompat macros like PUSHSTACKi() still push a non-real
stack, while functions which have been updated to use the new
push_stackinfo() etc will be able get a real AV. The next commit makes
use of that.
This means that existing code (core and XS) which hasn't been updated to
the new ref-counted stack regime can do stuff like:
PUSHSTACKi(FOO);
PUSHMARK(sp)
XPUSHs(sv);
call_sv();
where call_sv() (or rather, the runops loop it invokes) will be able to
determine that it's been called from a non-RC environment and that the
args on the stack aren't reference-counted.
The next commit will update the runops loops etc to do exactly that.
Commit: f3e79c9cf9a48c6eed3e8c71ec63dc2fb7ba1724
https://github.com/Perl/perl5/commit/f3e79c9cf9a48c6eed3e8c71ec63dc2fb7ba1724
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M cop.h
M embed.fnc
M embed.h
M inline.h
M makedef.pl
M perl.c
M perl.h
M pp_ctl.c
M pp_hot.c
M pp_pack.c
M pp_sort.c
M proto.h
M run.c
M scope.c
M sv.c
Log Message:
-----------
Allow argument stacks to be reference-counted
When built with PERL_RC_STACK, this substantial commit:
* makes stacks AvREAL() by default.
* adds the si_stack_nonrc_base field to the stackinfo structure.
* adds the runops_wrap() wrapper
It also adds rpp_obliterate_stack_to() for clearing the stack on
exceptions
Collectively, this allows each stack to be in one of three states:
1) AvREAL(PL_curstack) && PL_curstackinfo->si_stack_nonrc_base == 0
(the new default) all the SVs pointed to from the stack are
reference-counted.
2) AvREAL(PL_curstack) && PL_curstackinfo->si_stack_nonrc_base > 0
items on the stack are reference-counted only below si_stack_nonrc_base.
3) !AvREAL(PL_curstack)
(existing behaviour) no items on the stack are reference-counted.
The way it generally works is that runops loops assume that all the PP
functions they call out to are reference-count-aware. Where this isn't
yet the case, the recently-added pp_wrap() and xs_wrap() functions
assume a reference-counted stack, but use the si_stack_nonrc_base
mechanism to call out to PP or XS functions which aren't aware of a
reference-counted stack.
Conversely, the runops_wrap() function added by this commit wraps calls
to runops loops, since such loops work only with an RC stack. So if
called with a non-RC or partially-RC stack, the wrapper temporarily
fixes up the stack to be fully-RC, calls the real runops loop, then on
return reverts the stack back to it's non-RC ways, mortalising any
return values if necessary.
This downgrading and upgrading by pp_wrap()/xs_wrap() and
runops_wrap() allows handling of multiple nesting of when, for
example, perl calls pp_entersub(), which calls XS code, which calls
call_sv(), which calls a runops loop, which calls pp_entersub(), which
calls XS code, and so on.
For si_stack_nonrc_base, this index value marks the lowest position on
the argument stack which is not reference-counted. The special (and
normal) value of 0 indicates that *all* items on the stack are
reference-counted.
The new function rpp_obliterate_stack_to() is a bit like
rpp_popfree_to(), except that it can handle stacks in all three of the
states listed above. It's intended to be used when dying, throwing
exceptions or exiting, since the stack could be in any state when that
happens.
Note that as of this commit, PERL_XXX_TMP_NORC is still defined, which
means that even in the presence of AvREAL(PL_curstack) etc, the stack
isn't yet actually reference counted. So with this commit, perl goes
through all the motions, (calling wrappers like runops_wrap()
etc), but skips actually manipulating any reference counts. There will
be a few more commits, fixing up a few more things, before
PERL_XXX_TMP_NORC will be removed.
Commit: b63a623900b1f70f1c2f2de01ca740cd1cba6e67
https://github.com/Perl/perl5/commit/b63a623900b1f70f1c2f2de01ca740cd1cba6e67
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_ctl.c
Log Message:
-----------
add stack extend to Perl_die_unwind()
When invoked via a scalar-context eval, die_unwind() was pushing
&PL_sv_undef without extending the stack first. It's been this way for
many years. Spotted by visual inspection while adding rpp_() code.
I could get a SEGV with the following code, but I haven't added it as a
test as it's highly sensitive to exactly what size stack is initially
allocated and the OS's malloc().
my $x;
my @a =
($x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,
$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,
$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,
$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,
$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,
$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,
$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,
$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,$x,
scalar eval { die },
);
Commit: d9262482161c0671ae62517a3f3f0be2b0fb6ae2
https://github.com/Perl/perl5/commit/d9262482161c0671ae62517a3f3f0be2b0fb6ae2
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M toke.c
Log Message:
-----------
make RC-stack-aware: Perl_filter_read()
This function in toke.c calls out to a random C-level filter function
for each source input chunk. Because that function may in turn invoke
a Perl function via call_sv() - and may itself push stuff onto or off the
stack for that call - present that function with a
non-reference-counted stack environment for backwards compatibility.
Commit: 60130dca53120e1d23964586dd24663c3fe8db35
https://github.com/Perl/perl5/commit/60130dca53120e1d23964586dd24663c3fe8db35
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M inline.h
Log Message:
-----------
rpp_is_lone(): allow non-temp SV too
This function indicates whether an SV on the stack is kept alive only by
a single ref from the temps stack - which is often the case with stuff
pushed onto the stack by PP functions. Often this means that the SV can
be passed through rather then copied in places like returning from a
subroutine.
With a ref-counted stack, it's possible for a *non* SvTEMP SV to also be
stealable, if it has a refcount of 1, since that SV is being kept alive
purely by its (now refcounted) link from the stack.
So this commit adds that condition too (and also simplifies the
condition for efficiency).
In summary: originally perl (and then this function) did:
if (SvTEMP(sv) && SvREFCNT(sv) == 1) { ... steal it ... }
Now this function's condition is the equivalent of
#ifdef PERL_RC_STACK
( (SvREFCNT(sv) == 1)
|| (SvTEMP(sv) && SvREFCNT(sv) == 2))
#else
(SvTEMP(sv) && SvREFCNT(sv) == 1)
#endif
Commit: 33327fc76618322ed29b850e1a3aa6db82b3ae85
https://github.com/Perl/perl5/commit/33327fc76618322ed29b850e1a3aa6db82b3ae85
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M deb.c
M embed.fnc
M embed.h
M proto.h
Log Message:
-----------
Perl_debstack(): indicate stack refcount status
When displaying the stack with perl -Ds or -Dsv, put a vertical bar (|)
at the boundary between the reference-counted part of the stack and the
non-reference-counted part, if any.
In addition with -Dsv, for each stack show its status;
(real) all items on the stack are reference-counted
(partial real) items below si->si_stack_nonrc_base are RCed
blank no items are RCed
This commit switches to invoking S_deb_stack_n() directly, rather than
via the deb_stack_n() macro, as some compilers can't cope with the
'ifdef' amongst the calling args.
Commit: 1e23bda858bca193cd445719cd509641ca0d0f46
https://github.com/Perl/perl5/commit/1e23bda858bca193cd445719cd509641ca0d0f46
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M perl.h
Log Message:
-----------
disable PERL_XXX_TMP_NORC
This macro was just a temporary crutch that disabled actually adjusting
the reference count of things being pushed and popped off the stack,
even on PERL_RC_STACK builds. It allowed the core to be converted to
support a reference-counted stack as a bunch of incremental changes.
This commit turns it off, enabling the stack to become actually
reference-counted on PERL_RC_STACK builds.
In a few commits' time, this macro will be completely eliminated from
the source code.
Commit: d8e7e56cc92b7b08f401709dd62d3f1beb737b12
https://github.com/Perl/perl5/commit/d8e7e56cc92b7b08f401709dd62d3f1beb737b12
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M inline.h
M pp.h
Log Message:
-----------
stack push/pops: assert rpp_stack_is_rc() state
On perls built with both -DPERL_RC_STACK and -DDEBUG_LEAKING_SCALARS,
add asserts to the various old-style PUSHs() etc macros and new-style
rpp_push_1() etc functions that they're operating on the right sort of
stack. In particular:
PUSHs() and POPs() should only be used on stacks where rpp_stack_is_rc()
is false, since they don't modify the reference count of the SVs they
are pushing or popping.
Conversely, rpp_push_1(), rpp_popfree_1() etc should only be used on
stacks where rpp_stack_is_rc() is true, since they modify the reference
counts of the SVs they push and pop.
On perls not compiled with PERL_RC_STACK, the rpp_ functions don't
modify the reference counts, but on such builds the rpp_stack_is_rc()
assertions in the rpp_ functions are disabled, so it all works out
still.
Commit: de588f44fe3d5f6720fb193286e4aded2838199c
https://github.com/Perl/perl5/commit/de588f44fe3d5f6720fb193286e4aded2838199c
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M dump.c
Log Message:
-----------
runops_debug(): add RC-stack assertions
on PERL_RC_STACK builds,
1) assert that the stack is reference-counted (rpp_stack_is_rc()).
2) assert the any split point (si_stack_nonrc_base) isn't above the
top of the stack.
Commit: 7955be58143024b2b77811c487344150f02f1663
https://github.com/Perl/perl5/commit/7955be58143024b2b77811c487344150f02f1663
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_hot.c
Log Message:
-----------
pp_wrap(), xs_wrap(): extract some common code
and put it in a static function, S_pp_xs_wrap_return().
Commit: abe9589e487db745a93764494d40acf17029d040
https://github.com/Perl/perl5/commit/abe9589e487db745a93764494d40acf17029d040
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_hot.c
Log Message:
-----------
tweak pp_wrap() and xs_wrap()
After bumping up the reference counts of the returned values,
reset si_stack_nonrc_base earlier, so that if perl dies while
decrementing the original args, all reference counts will be properly
accounted for.
Also in xs_wrap(), only bother doing
PL_markstack_ptr[0] += nargs;
in the branch where nargs > 0.
Commit: 7e0d26bc39ac1ccf439cad708458c039aa136e9f
https://github.com/Perl/perl5/commit/7e0d26bc39ac1ccf439cad708458c039aa136e9f
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M MANIFEST
M ext/XS-APItest/APItest.xs
A ext/XS-APItest/t/xsppwrap.t
Log Message:
-----------
add tests for XSPP_wrapped() macro
This new macro allows an old-style non-reference-counted PP-style
function to be used on a PERL_RC_STACK builds. It's intended for
non-core PP functions which are typically in an XS file and are used to
replace the PP function of an existing op, or to be attached to a custom
op.
It's virtually identical to the PP_wrapped() macro, except that it
uses the name as-is rather than prepending Perl_ to the name
Commit: 005ea4fb620a61cb598a9063d0617dec22dfa605
https://github.com/Perl/perl5/commit/005ea4fb620a61cb598a9063d0617dec22dfa605
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M ext/XS-APItest/APItest.xs
Log Message:
-----------
XS::APItest::clone_with_stack(); check SI RC state
In this test function, push a couple of stackinfos, one with a
ref-counted stack, and one without.
After cloning, pop the cloned stackinfos and assert that the cloned
argument stacks are also appropriately RC or non-RC.
This should probably have been done properly as some new tests rather
than a couple of asserts, but that would have involved a lot more
effort.
Commit: 498e35335469ed77474654e00086ea250ee129da
https://github.com/Perl/perl5/commit/498e35335469ed77474654e00086ea250ee129da
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M dist/threads/threads.xs
M ext/XS-APItest/t/magic.t
M inline.h
M op.c
M perl.c
M perl.h
M pp_ctl.c
M pp_hot.c
M pp_pack.c
M pp_sort.c
M run.c
M t/cmd/for.t
M universal.c
Log Message:
-----------
Eliminate PERL_XXX_TMP_NORC
This macro was disabled a few commits ago. Now remove all use of it
from the core.
It was just a temporary crutch that disabled actually adjusting the
reference count of things being pushed and popped off the stack, even on
PERL_RC_STACK builds. It allowed the core to be converted to support a
reference-counted stack as a bunch of incremental changes.
Commit: 0afdcd5a4788b12ae817d154b37bedecb28ccb85
https://github.com/Perl/perl5/commit/0afdcd5a4788b12ae817d154b37bedecb28ccb85
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pod/perlguts.pod
Log Message:
-----------
add perlguts section on a reference-counted stack
Explain what all the new rpp_foo() functions are for.
Commit: b7f94df2b4f26722f1f9199a3582b174a8442d15
https://github.com/Perl/perl5/commit/b7f94df2b4f26722f1f9199a3582b174a8442d15
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_ctl.c
Log Message:
-----------
pp_goto: fix macro-in-macro compile error
Turns out MSVC 1.42 doesn't like
FOO(bar,
#ifdef X
1
#else
0
#endif
);
where FOO is a macro.
Commit: 0617a5f3d193da8bc4a499a085eeb5c2bc65422e
https://github.com/Perl/perl5/commit/0617a5f3d193da8bc4a499a085eeb5c2bc65422e
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M run.c
M t/op/grep.t
Log Message:
-----------
Perl_runops_wrap((): don't mortalise NULLs
This function was doing a delayed ref count decrement of all the SVs it
had previously temporarily incremented, by mortalising each one. For
efficiency it was just doing a Copy() of a block of SVs addresses from
the argument stack to the TEMPs stack.
However, the TEMPs stack can't cope with NULL pointers, while there are
sometimes NULL pointers on the argument stack - in particular, while
doing a map, any temporary holes in the stack are set to NULL on
PERL_RC_STACK builds.
The fix is simple - copy individual non-NULL addresses to the TEMPS
stack rather than doing a block copy.
Commit: 735ece1f92da7522d061bf479a21506afe766607
https://github.com/Perl/perl5/commit/735ece1f92da7522d061bf479a21506afe766607
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_ctl.c
Log Message:
-----------
pp_caller(): set @DB::args earlier
Copy @_ SV pointers to @DB::args earlier, before pp_caller() has the
chance to create any new SVs (e.g. for the package name). This will give
the next commit a chance to discover and skip any freed elements in @_.
This commit makes no changes to the block of code that is moved;
that's saved for the next commit.
Commit: 3f844e25e112a9f457bffd6bf754a0e976d910b2
https://github.com/Perl/perl5/commit/3f844e25e112a9f457bffd6bf754a0e976d910b2
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_ctl.c
M t/op/caller.t
Log Message:
-----------
caller(): don't copy freed SV pointer to @DB::args
When pp_caller() aliases the elements of @_ to @DB::args, it may include
pointers to array elements which have been shifted away. So for example
in
sub f { my $self = shift; ....; croak() }
it populates $DB::args[0] with the SV pointer one position below the
AvARRAY() of @_. This means that the argument lists in the stack
backtrace provided by croak() will include the original first arg,
which is nice, but is very fragile. There is no guarantee that that SV
hasn't been freed or reallocated in the meantime.
This commit adds a check for each SV pointer being copied to @DB::args,
which NULLs it if the SV has a refcount of 0.
This means that in something like:
package DB:
() = caller($i);
my @args = @DB::args;
perl will no longer panic about copying a freed SV.
Note that this commit does not address the issue of the SV having already
been reallocated. In the example above, some elements of @args may
contain a copy of some other random variable. However, the previous
commit moved to earlier in the function, the block of code in
pp_caller() which populates @DB::args, to before pp_caller() allocates
new SVs for things like the package name. Which means the RC==0 test
added by this commit has a better chance of spotting SVs which have been
freed but not yet reallocated.
In summary, @DB::args is still a horrible, fragile hack, but these two
commits make it slightly less fragile in some circumstances.
Commit: c42e5da75e48b9391ab7b176c0f93c7204f927a6
https://github.com/Perl/perl5/commit/c42e5da75e48b9391ab7b176c0f93c7204f927a6
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M pp_hot.c
M t/op/goto.t
Log Message:
-----------
when (re)creating @_, zero its elements
When a sub's @_ gets abandoned (e.g. when 'goto &bar' "donates" the
current @_ to the new sub), a new AV is created at pad[0] for the old
sub. Perl alloc()'s the AvARRAY() buffer for the new AV, but didn't zero
it. This didn't used to be a problem, because @_ AVs are created
!AvREAL(), so the first thing perl did when someone tries to modify @_,
is to call av_reify() on it. And it just so happens that av_reify()
zeros out all the unused slots on the array first. So code like
$_[1] = 1;
do_something_with($_[0])
was fine.
However, on PERL_RC_STACK builds, @_ is AvREAL() by default now, so
av_reify() doesn't get called, so AvARRAY() can sometimes contain random
wild pointers.
The fix is simple: zero AvARRAY() when creating it.
This was showing as a failure in Test::Trap
Commit: 9cf734d8ad15fd880dac6f4d2d093953d3856677
https://github.com/Perl/perl5/commit/9cf734d8ad15fd880dac6f4d2d093953d3856677
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M inline.h
M pod/perlguts.pod
M pp.h
Log Message:
-----------
RC_STACK asserts without DEBUG_LEAKING_SCALARS
An earlier commit added some asserts to the old-style and new-style
stack push/pop functions such as PUSHs() or rpp_popfree_1(). These
assert that the stack is reference-counted or not as appropriate.
These asserts were enabled only if perl was built with all of
DEBUGGING && PERL_RC_STACK && DEBUG_LEAKING_SCALARS.
This commit makes the asserts available under just
DEBUGGING && PERL_RC_STACK
Initially I was worried about the performance implications (you expect
DEBUGGING builds to be slow, but not *too* slow), but they don't seem
too bad. So by making them more likely to be enabled, they're more
likely to help people spot code that needs fixing (e.g. code still doing
POPs when the stack is reference counted and the function hasn't been
wrapped).
Commit: d2ccb40b1455fd37a3c4782a905ca235a445edab
https://github.com/Perl/perl5/commit/d2ccb40b1455fd37a3c4782a905ca235a445edab
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M MANIFEST
A t/op/refstack.t
Log Message:
-----------
add t/op/refstack.t
Add a suite of tests which check whether all the "stack not reference
counted" tickets are fixed when perl is built with PERL_RC_STACK
Commit: 02a97567655db7badbbec37154265a19db2c8485
https://github.com/Perl/perl5/commit/02a97567655db7badbbec37154265a19db2c8485
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M embed.fnc
M embed.h
M inline.h
M pod/perlguts.pod
M pp_ctl.c
M pp_hot.c
M pp_sort.c
M proto.h
Log Message:
-----------
add rpp_invoke_xs() function
This function is just a neater version of:
#ifdef PERL_RC_STACK
Perl_xs_wrap(aTHX_ CvXSUB(cv), cv);
#else
(void)(*CvXSUB(cv))(aTHX_ cv);
#endif
but shortly it will be extended to allow XS CVs to be flagged as
"RC-aware".
Commit: 2899bb28de16dfbadf5cfc19f6015cb1a46d2918
https://github.com/Perl/perl5/commit/2899bb28de16dfbadf5cfc19f6015cb1a46d2918
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-12 (Sat, 12 Aug 2023)
Changed paths:
M MANIFEST
M cv.h
M ext/XS-APItest/APItest.xs
A ext/XS-APItest/t/rpp_invoke_xs.t
M inline.h
Log Message:
-----------
support RC XS subs: add CVf_XS_RCSTACK flag
Allow an XS sub to be flagged with CVf_XS_RCSTACK, which indicates that
it expects a reference-counted stack - and so pp_entersub() etc should
invoke it directly rather than via xs_wrap() on PERL_RC_STACK builds.
Note that there is not yet any syntax in an XS file which supports
marking an XS sub as 'RC-aware', so this facility is very much
in the early stages and "at your own risk", requiring the CV to
manually have its CVf_XS_RCSTACK flag set.
Compare: https://github.com/Perl/perl5/compare/9bd72d6fa6f7%5E...2899bb28de16
