Branch: refs/heads/smoke-me/davem/rc_stack2
Home: https://github.com/Perl/perl5
Commit: 24b19b5ff0128e55c377933f81cbdada1ce4c4a7
https://github.com/Perl/perl5/commit/24b19b5ff0128e55c377933f81cbdada1ce4c4a7
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: af26e127b2471ce18f7cda719f4c91a10a51b3f1
https://github.com/Perl/perl5/commit/af26e127b2471ce18f7cda719f4c91a10a51b3f1
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 45c43ff3713fb60dcb508257dc402d4c0e8196e4
https://github.com/Perl/perl5/commit/45c43ff3713fb60dcb508257dc402d4c0e8196e4
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 0315e7ccaf8c1d4fd605120946a774608a209ff6
https://github.com/Perl/perl5/commit/0315e7ccaf8c1d4fd605120946a774608a209ff6
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: eefb89f8710557e8293fe07268ac60118b4689c0
https://github.com/Perl/perl5/commit/eefb89f8710557e8293fe07268ac60118b4689c0
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 483d0748e726d2f2fc3ac0bf08d1c46d00e04835
https://github.com/Perl/perl5/commit/483d0748e726d2f2fc3ac0bf08d1c46d00e04835
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 4450252fdf1e1cfb154100e816b3edf610af2306
https://github.com/Perl/perl5/commit/4450252fdf1e1cfb154100e816b3edf610af2306
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: bb78617877c4aa2e7d167b6934b394b1fc3fa679
https://github.com/Perl/perl5/commit/bb78617877c4aa2e7d167b6934b394b1fc3fa679
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 3b1df59e652df74b00eca1b7def7d5d96e899f06
https://github.com/Perl/perl5/commit/3b1df59e652df74b00eca1b7def7d5d96e899f06
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: fe247cc2a834f9061acd1e24a09107912a33d3b7
https://github.com/Perl/perl5/commit/fe247cc2a834f9061acd1e24a09107912a33d3b7
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 5eb1ca40a31a79e43b01e848930883ba035c611c
https://github.com/Perl/perl5/commit/5eb1ca40a31a79e43b01e848930883ba035c611c
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 84dc01ec7cdb97b321177cc328fba65f4b880fe3
https://github.com/Perl/perl5/commit/84dc01ec7cdb97b321177cc328fba65f4b880fe3
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: c8ef37a4579a926c1026205a1bf1d952ef58324a
https://github.com/Perl/perl5/commit/c8ef37a4579a926c1026205a1bf1d952ef58324a
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 0127060817386de4129d6fca3147bef7f4cc1e6f
https://github.com/Perl/perl5/commit/0127060817386de4129d6fca3147bef7f4cc1e6f
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 3f50405bb9fa401ba743487b928067b0b9e6fac0
https://github.com/Perl/perl5/commit/3f50405bb9fa401ba743487b928067b0b9e6fac0
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 1c04d885d33f04e11f9b7f276fd6b1ef244ec0a2
https://github.com/Perl/perl5/commit/1c04d885d33f04e11f9b7f276fd6b1ef244ec0a2
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 8d4809e11c5faef6b7d0ab2501a30a99d3847494
https://github.com/Perl/perl5/commit/8d4809e11c5faef6b7d0ab2501a30a99d3847494
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 8b2bf0708150757b9125e287f998edbfe06d26f1
https://github.com/Perl/perl5/commit/8b2bf0708150757b9125e287f998edbfe06d26f1
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: bab8138a304058df60a2959e20127fbe8b743583
https://github.com/Perl/perl5/commit/bab8138a304058df60a2959e20127fbe8b743583
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: c5c6ee9f72326d6040f9907a8cd87f0a32491e2e
https://github.com/Perl/perl5/commit/c5c6ee9f72326d6040f9907a8cd87f0a32491e2e
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 3dd66a643c9d044534c6a495d0faf0f076a4fc8d
https://github.com/Perl/perl5/commit/3dd66a643c9d044534c6a495d0faf0f076a4fc8d
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: a710a39b8ec62ecb8dfd014c8e94f576d98fdd05
https://github.com/Perl/perl5/commit/a710a39b8ec62ecb8dfd014c8e94f576d98fdd05
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: d58a9687ece49682574c3a8b0ed24b0126d2053c
https://github.com/Perl/perl5/commit/d58a9687ece49682574c3a8b0ed24b0126d2053c
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 2bdae954afd170109645a528fc0b0d7169557d4c
https://github.com/Perl/perl5/commit/2bdae954afd170109645a528fc0b0d7169557d4c
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 9ea8db092b53cf229caa321b171d526e0656c9ae
https://github.com/Perl/perl5/commit/9ea8db092b53cf229caa321b171d526e0656c9ae
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 1d026c9a9bef8fd6dfb68f1b87980f4c73d15aee
https://github.com/Perl/perl5/commit/1d026c9a9bef8fd6dfb68f1b87980f4c73d15aee
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: ffbd35f20eb7a9f2a352ab8fd49f8f08b548d511
https://github.com/Perl/perl5/commit/ffbd35f20eb7a9f2a352ab8fd49f8f08b548d511
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 3a3aca281e76e5041e18616c8b20c3236538972d
https://github.com/Perl/perl5/commit/3a3aca281e76e5041e18616c8b20c3236538972d
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 55469df3b1439b5fd94b277db8a3450c5cb5699c
https://github.com/Perl/perl5/commit/55469df3b1439b5fd94b277db8a3450c5cb5699c
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 8f76dea6161eeb96da03a5593ce485a6da444aec
https://github.com/Perl/perl5/commit/8f76dea6161eeb96da03a5593ce485a6da444aec
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 0f64491c9cdbd9e79417d197149fc445b2dc4146
https://github.com/Perl/perl5/commit/0f64491c9cdbd9e79417d197149fc445b2dc4146
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 76ad30a8202531cbab9b21b3188e2c9c70558d33
https://github.com/Perl/perl5/commit/76ad30a8202531cbab9b21b3188e2c9c70558d33
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 55bb823071f6875e1909fe98cfce3f545654ce19
https://github.com/Perl/perl5/commit/55bb823071f6875e1909fe98cfce3f545654ce19
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 8b55d99e490ddf171372987ccfd06d63a2dae1ed
https://github.com/Perl/perl5/commit/8b55d99e490ddf171372987ccfd06d63a2dae1ed
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: b3c301bbeeed7c75d093f1e007b0b24fb0ce1ae6
https://github.com/Perl/perl5/commit/b3c301bbeeed7c75d093f1e007b0b24fb0ce1ae6
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 810deb04af49a239ee7c55ff58b87ca3cf407cf7
https://github.com/Perl/perl5/commit/810deb04af49a239ee7c55ff58b87ca3cf407cf7
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 29ea9b8a5a35fcfde92f289a21765150c242850a
https://github.com/Perl/perl5/commit/29ea9b8a5a35fcfde92f289a21765150c242850a
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 064d2ad0fc89254fc8a61f7728bbd6335ee3a165
https://github.com/Perl/perl5/commit/064d2ad0fc89254fc8a61f7728bbd6335ee3a165
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 5c9aca77ec9a3545ccd5f71525f8419b5b0147fb
https://github.com/Perl/perl5/commit/5c9aca77ec9a3545ccd5f71525f8419b5b0147fb
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 Aug 2023)
Changed paths:
M dist/threads/lib/threads.pm
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: 600728531fc2e621795e5345e9010ac32c2df09d
https://github.com/Perl/perl5/commit/600728531fc2e621795e5345e9010ac32c2df09d
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 982845e8e26f1f8cda840b2543d92e4bba735f6e
https://github.com/Perl/perl5/commit/982845e8e26f1f8cda840b2543d92e4bba735f6e
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 28580fd1f45bed204d97ac9cb051fc6d6cc48294
https://github.com/Perl/perl5/commit/28580fd1f45bed204d97ac9cb051fc6d6cc48294
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 6fa0a102361ddaeadfb6426fb4d7fd8907540cad
https://github.com/Perl/perl5/commit/6fa0a102361ddaeadfb6426fb4d7fd8907540cad
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 Aug 2023)
Changed paths:
M class.c
Log Message:
-----------
make RC-stack-aware: class.c: pp_methstart etc
Commit: 9f70b42ae33d4a5a770a0edf13fd2b9a67b38691
https://github.com/Perl/perl5/commit/9f70b42ae33d4a5a770a0edf13fd2b9a67b38691
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 0b260301389aed57e613c263af117275cc74c6d8
https://github.com/Perl/perl5/commit/0b260301389aed57e613c263af117275cc74c6d8
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 2b95dbd6dcbab875282a6e33e36789fa6d0fa097
https://github.com/Perl/perl5/commit/2b95dbd6dcbab875282a6e33e36789fa6d0fa097
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: bb3a68d1a6bb7459e0bc648351b02eb30edfdab8
https://github.com/Perl/perl5/commit/bb3a68d1a6bb7459e0bc648351b02eb30edfdab8
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 0081067206aa2bcdf84505105659e7517d706029
https://github.com/Perl/perl5/commit/0081067206aa2bcdf84505105659e7517d706029
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 45942fb750e80bbbd354aee26d409fe813955560
https://github.com/Perl/perl5/commit/45942fb750e80bbbd354aee26d409fe813955560
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 04e44eb0e63a0673cfca2a9d5c85c041143fa261
https://github.com/Perl/perl5/commit/04e44eb0e63a0673cfca2a9d5c85c041143fa261
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: ae091657d3b5b15e20eb296e792a2230105370c6
https://github.com/Perl/perl5/commit/ae091657d3b5b15e20eb296e792a2230105370c6
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: e496c5dbc1053d38fdc9674ad18423834c9bc365
https://github.com/Perl/perl5/commit/e496c5dbc1053d38fdc9674ad18423834c9bc365
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 4f33d997195e90ec0e817bd04f2d62b0b0e9f3e4
https://github.com/Perl/perl5/commit/4f33d997195e90ec0e817bd04f2d62b0b0e9f3e4
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: dfd7ce929192fa66fa5d7d948ec2af1eaaad62fa
https://github.com/Perl/perl5/commit/dfd7ce929192fa66fa5d7d948ec2af1eaaad62fa
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: a1131a5068f5f0c5d71ab483f4fe794972afcd90
https://github.com/Perl/perl5/commit/a1131a5068f5f0c5d71ab483f4fe794972afcd90
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 8d47b4169dc4924debc5c47dba2e659aa2e3f3e8
https://github.com/Perl/perl5/commit/8d47b4169dc4924debc5c47dba2e659aa2e3f3e8
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 557d6e73b3ca7280871e3816d35d9eb0e8aae111
https://github.com/Perl/perl5/commit/557d6e73b3ca7280871e3816d35d9eb0e8aae111
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: c806e3fbac315913955acc0aff1c86b31ec2d918
https://github.com/Perl/perl5/commit/c806e3fbac315913955acc0aff1c86b31ec2d918
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 381c82c3d0c70fcbc39cf3a24302f9fd67b146c0
https://github.com/Perl/perl5/commit/381c82c3d0c70fcbc39cf3a24302f9fd67b146c0
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 7e2aa65ba111d98f8691bcfdcac89d1de3d2803c
https://github.com/Perl/perl5/commit/7e2aa65ba111d98f8691bcfdcac89d1de3d2803c
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 353b2b328d8afedd393677296490915017d44f3a
https://github.com/Perl/perl5/commit/353b2b328d8afedd393677296490915017d44f3a
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 8cefaa3f325324e5c79a26c1f6f11ca5c98ff11f
https://github.com/Perl/perl5/commit/8cefaa3f325324e5c79a26c1f6f11ca5c98ff11f
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: a49733cd47d4cd0cc2e8a98bd04c473b24a32f94
https://github.com/Perl/perl5/commit/a49733cd47d4cd0cc2e8a98bd04c473b24a32f94
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 99440763f926c6f34cce86855cfb9e2c5572a346
https://github.com/Perl/perl5/commit/99440763f926c6f34cce86855cfb9e2c5572a346
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 3f16b5f6985c42a69ff68aaf8986d9ba01035bfb
https://github.com/Perl/perl5/commit/3f16b5f6985c42a69ff68aaf8986d9ba01035bfb
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: e96dd01c49bc9af280a3f7a0c9e9e4af289bbdf7
https://github.com/Perl/perl5/commit/e96dd01c49bc9af280a3f7a0c9e9e4af289bbdf7
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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: 14148aac9cfc6e1e4c4ddb99a21ecd2ebf0934fc
https://github.com/Perl/perl5/commit/14148aac9cfc6e1e4c4ddb99a21ecd2ebf0934fc
Author: David Mitchell <da...@iabyn.com>
Date: 2023-08-04 (Fri, 04 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).
Compare: https://github.com/Perl/perl5/compare/f67f2243f29c...14148aac9cfc
