Re: [PATCH][_GLIBCXX_DEBUG] Fix std::__niter_base behavior
On Tue, 20 Feb 2024 at 18:43, François Dumont wrote: > >libstdc++: [_GLIBCXX_DEBUG] Fix std::__niter_wrap behavior > > In _GLIBCXX_DEBUG mode the std::__niter_base can remove 2 layers, the > __gnu_debug::_Safe_iterator<> and the __gnu_cxx::__normal_iterator<>. > When std::__niter_wrap is called to build a __gnu_debug::_Safe_iterator<> > from a __gnu_cxx::__normal_iterator<> we then have a consistency issue > as the difference between the 2 iterators will done on a __normal_iterator > on one side and a C pointer on the other. To avoid this problem call > std::__niter_base on both input iterators. > > libstdc++-v3/ChangeLog: > > * include/bits/stl_algobase.h (std::__niter_wrap): Add a call to > std::__niter_base on res iterator. > > Tested under Linux x86_64 normal and _GLIBCXX_DEBUG modes in c++98, c++11, > c++17. > > Ok to commit ? > OK, thanks.
Re: [PATCH][_GLIBCXX_DEBUG] Fix std::__niter_base behavior
libstdc++: [_GLIBCXX_DEBUG] Fix std::__niter_wrap behavior
In _GLIBCXX_DEBUG mode the std::__niter_base can remove 2 layers, the
__gnu_debug::_Safe_iterator<> and the __gnu_cxx::__normal_iterator<>.
When std::__niter_wrap is called to build a
__gnu_debug::_Safe_iterator<>
from a __gnu_cxx::__normal_iterator<> we then have a consistency issue
as the difference between the 2 iterators will done on a
__normal_iterator
on one side and a C pointer on the other. To avoid this problem call
std::__niter_base on both input iterators.
libstdc++-v3/ChangeLog:
* include/bits/stl_algobase.h (std::__niter_wrap): Add a
call to
std::__niter_base on res iterator.
Tested under Linux x86_64 normal and _GLIBCXX_DEBUG modes in c++98,
c++11, c++17.
Ok to commit ?
François
On 19/02/2024 09:21, Jonathan Wakely wrote:
On Mon, 19 Feb 2024, 08:12 Jonathan Wakely, wrote:
On Mon, 19 Feb 2024, 07:08 Stephan Bergmann,
wrote:
On 2/17/24 15:14, François Dumont wrote:
> Thanks for the link, tested and committed.
I assume this is the cause for the below failure now,
Yes, the new >= C++11 overload of __niter_base recursively unwraps
multiple layers of wrapping, so that a safe iterator wrapping a
normal iterator wrapping a pointer is unwrapped to just a pointer.
But then __niter_wrap doesn't restore both layers.
Actually that's not the problem. __niter_wrap would restore both
layers, except that it uses __niter_base itself:
> 347 | { return __from + (__res - std::__niter_base(__from)); }
> | ~~~^~~~
And it seems to be getting called with the wrong types. Maybe that's
just a bug in std:: erase or maybe niter_wrap needs adjusting.
I'll check in a couple of hours if François doesn't get to it first.
I have to wonder how this wasn't caught by existing tests though.
diff --git a/libstdc++-v3/include/bits/stl_algobase.h
b/libstdc++-v3/include/bits/stl_algobase.h
index 0f73da13172..d534e02871f 100644
--- a/libstdc++-v3/include/bits/stl_algobase.h
+++ b/libstdc++-v3/include/bits/stl_algobase.h
@@ -344,7 +344,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX20_CONSTEXPR
inline _From
__niter_wrap(_From __from, _To __res)
-{ return __from + (__res - std::__niter_base(__from)); }
+{ return __from + (std::__niter_base(__res) - std::__niter_base(__from)); }
// No need to wrap, iterator already has the right type.
template
Re: [PATCH][_GLIBCXX_DEBUG] Fix std::__niter_base behavior
Turns out that 23_containers/vector/erasure.cc was showing the problem
in _GLIBCXX_DEBUG mode.
I had only run 25_algorithms tests in _GLIBCXX_DEBUG mode.
This is what I'm testing, I 'll let you know tomorrow morning if all
successful.
Of course feel free to do or ask for a revert instead.
François
On 19/02/2024 09:21, Jonathan Wakely wrote:
On Mon, 19 Feb 2024, 08:12 Jonathan Wakely, wrote:
On Mon, 19 Feb 2024, 07:08 Stephan Bergmann,
wrote:
On 2/17/24 15:14, François Dumont wrote:
> Thanks for the link, tested and committed.
I assume this is the cause for the below failure now,
Yes, the new >= C++11 overload of __niter_base recursively unwraps
multiple layers of wrapping, so that a safe iterator wrapping a
normal iterator wrapping a pointer is unwrapped to just a pointer.
But then __niter_wrap doesn't restore both layers.
Actually that's not the problem. __niter_wrap would restore both
layers, except that it uses __niter_base itself:
> 347 | { return __from + (__res - std::__niter_base(__from)); }
> | ~~~^~~~
And it seems to be getting called with the wrong types. Maybe that's
just a bug in std:: erase or maybe niter_wrap needs adjusting.
I'll check in a couple of hours if François doesn't get to it first.
I have to wonder how this wasn't caught by existing tests though.
diff --git a/libstdc++-v3/include/bits/stl_algobase.h
b/libstdc++-v3/include/bits/stl_algobase.h
index 0f73da13172..d534e02871f 100644
--- a/libstdc++-v3/include/bits/stl_algobase.h
+++ b/libstdc++-v3/include/bits/stl_algobase.h
@@ -344,7 +344,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX20_CONSTEXPR
inline _From
__niter_wrap(_From __from, _To __res)
-{ return __from + (__res - std::__niter_base(__from)); }
+{ return __from + (std::__niter_base(__res) - std::__niter_base(__from)); }
// No need to wrap, iterator already has the right type.
template
Re: [PATCH][_GLIBCXX_DEBUG] Fix std::__niter_base behavior
On Mon, 19 Feb 2024, 08:12 Jonathan Wakely, wrote:
>
>
> On Mon, 19 Feb 2024, 07:08 Stephan Bergmann, wrote:
>
>> On 2/17/24 15:14, François Dumont wrote:
>> > Thanks for the link, tested and committed.
>>
>> I assume this is the cause for the below failure now,
>>
>
> Yes, the new >= C++11 overload of __niter_base recursively unwraps
> multiple layers of wrapping, so that a safe iterator wrapping a normal
> iterator wrapping a pointer is unwrapped to just a pointer. But then
> __niter_wrap doesn't restore both layers.
>
Actually that's not the problem. __niter_wrap would restore both layers,
except that it uses __niter_base itself:
> 347 | { return __from + (__res - std::__niter_base(__from)); }
> | ~~~^~~~
And it seems to be getting called with the wrong types. Maybe that's just a
bug in std:: erase or maybe niter_wrap needs adjusting.
I'll check in a couple of hours if François doesn't get to it first.
I have to wonder how this wasn't caught by existing tests though.
Re: [PATCH][_GLIBCXX_DEBUG] Fix std::__niter_base behavior
On Mon, 19 Feb 2024, 07:08 Stephan Bergmann, wrote:
> On 2/17/24 15:14, François Dumont wrote:
> > Thanks for the link, tested and committed.
>
> I assume this is the cause for the below failure now,
>
Yes, the new >= C++11 overload of __niter_base recursively unwraps multiple
layers of wrapping, so that a safe iterator wrapping a normal iterator
wrapping a pointer is unwrapped to just a pointer. But then __niter_wrap
doesn't restore both layers.
I think the change might need to be reverted.
> > $ cat test.cc
> > #include
> > #include
> > void f(std::vector , void const * p) {
> > std::erase(v, p);
> > }
>
> > $ ~/gcc/inst/bin/g++ -std=c++20 -D_GLIBCXX_DEBUG -fsyntax-only test.cc
> > In file included from ~/gcc/inst/include/c++/14.0.1/algorithm:60,
> > from test.cc:1:
> > ~/gcc/inst/include/c++/14.0.1/bits/stl_algobase.h: In instantiation of
> ‘constexpr _From std::__niter_wrap(_From, _To) [with _From =
> __gnu_debug::_Safe_iterator<__gnu_cxx::__normal_iterator __cxx1998::vector > >,
> __debug::vector, random_access_iterator_tag>; _To =
> __gnu_cxx::__normal_iterator allocator > >]’:
> > ~/gcc/inst/include/c++/14.0.1/vector:144:29: required from ‘constexpr
> typename std::__debug::vector<_Tp, _Allocator>::size_type
> std::erase(__debug::vector<_Tp, _Alloc>&, const _Up&) [with _Tp = const
> void*; _Alloc = allocator; _Up = const void*; typename
> __debug::vector<_Tp, _Allocator>::size_type = long unsigned int]’
> > 144 | __cont.erase(__niter_wrap(__cont.begin(), __removed),
> > |^~~
> > test.cc:4:15: required from here
> > 4 | std::erase(v, p);
> > | ~~^~
> > ~/gcc/inst/include/c++/14.0.1/bits/stl_algobase.h:347:30: error: no
> match for ‘operator-’ (operand types are
> ‘__gnu_cxx::__normal_iterator void*, std::allocator > >’ and ‘const void**’)
> > 347 | { return __from + (__res - std::__niter_base(__from)); }
> > | ~~~^~~~
> > In file included from
> ~/gcc/inst/include/c++/14.0.1/bits/stl_algobase.h:67:
> > ~/gcc/inst/include/c++/14.0.1/bits/stl_iterator.h:1148:7: note:
> candidate: ‘constexpr __gnu_cxx::__normal_iterator<_Iterator, _Container>
> __gnu_cxx::__normal_iterator<_Iterator,
> _Container>::operator-(difference_type) const [with _Iterator = const
> void**; _Container = std::__cxx1998::vector std::allocator >; difference_type = long int]’ (near match)
> > 1148 | operator-(difference_type __n) const _GLIBCXX_NOEXCEPT
> > | ^~~~
> > ~/gcc/inst/include/c++/14.0.1/bits/stl_iterator.h:1148:7: note:
> conversion of argument 1 would be ill-formed:
> > ~/gcc/inst/include/c++/14.0.1/bits/stl_algobase.h:347:49: error: invalid
> conversion from ‘const void**’ to ‘__gnu_cxx::__normal_iterator void**, std::__cxx1998::vector >
> >::difference_type’ {aka ‘long int’} [-fpermissive]
> > 347 | { return __from + (__res - std::__niter_base(__from)); }
> > |~^~~~
> > | |
> > | const void**
> > ~/gcc/inst/include/c++/14.0.1/bits/stl_iterator.h:618:5: note:
> candidate: ‘template constexpr decltype
> ((__y.base() - __x.base())) std::operator-(const
> reverse_iterator<_IteratorL>&, const reverse_iterator<_IteratorR>&)’
> > 618 | operator-(const reverse_iterator<_IteratorL>& __x,
> > | ^~~~
> > ~/gcc/inst/include/c++/14.0.1/bits/stl_iterator.h:618:5: note:
> template argument deduction/substitution failed:
> > ~/gcc/inst/include/c++/14.0.1/bits/stl_algobase.h:347:30: note:
> ‘__gnu_cxx::__normal_iterator void*, std::allocator > >’ is not derived from ‘const
> std::reverse_iterator<_IteratorL>’
> > 347 | { return __from + (__res - std::__niter_base(__from)); }
> > | ~~~^~~~
> > ~/gcc/inst/include/c++/14.0.1/bits/stl_iterator.h:1789:5: note:
> candidate: ‘template constexpr decltype
> ((__x.base() - __y.base())) std::operator-(const
> move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)’
> > 1789 | operator-(const move_iterator<_IteratorL>& __x,
> > | ^~~~
> > ~/gcc/inst/include/c++/14.0.1/bits/stl_iterator.h:1789:5: note:
> template argument deduction/substitution failed:
> > ~/gcc/inst/include/c++/14.0.1/bits/stl_algobase.h:347:30: note:
> ‘__gnu_cxx::__normal_iterator void*, std::allocator > >’ is not derived from ‘const
> std::move_iterator<_IteratorL>’
> > 347 | { return __from + (__res - std::__niter_base(__from)); }
> > | ~~~^~~~
> > ~/gcc/inst/include/c++/14.0.1/bits/stl_iterator.h:1312:5: note:
> candidate: ‘template
> constexpr decltype ((__lhs.base() - __rhs.base()))
> __gnu_cxx::operator-(const __normal_iterator<_IteratorL, _Container>&,
>
Re: [PATCH][_GLIBCXX_DEBUG] Fix std::__niter_base behavior
On 2/17/24 15:14, François Dumont wrote:
Thanks for the link, tested and committed.
I assume this is the cause for the below failure now,
$ cat test.cc
#include
#include
void f(std::vector , void const * p) {
std::erase(v, p);
}
$ ~/gcc/inst/bin/g++ -std=c++20 -D_GLIBCXX_DEBUG -fsyntax-only test.cc
In file included from ~/gcc/inst/include/c++/14.0.1/algorithm:60,
from test.cc:1:
~/gcc/inst/include/c++/14.0.1/bits/stl_algobase.h: In instantiation of ‘constexpr _From std::__niter_wrap(_From, _To) [with
_From = __gnu_debug::_Safe_iterator<__gnu_cxx::__normal_iterator > >, __debug::vector, random_access_iterator_tag>; _To =
__gnu_cxx::__normal_iterator > >]’:
~/gcc/inst/include/c++/14.0.1/vector:144:29: required from ‘constexpr typename std::__debug::vector<_Tp,
_Allocator>::size_type std::erase(__debug::vector<_Tp, _Alloc>&, const _Up&) [with _Tp = const
void*; _Alloc = allocator; _Up = const void*; typename __debug::vector<_Tp,
_Allocator>::size_type = long unsigned int]’
144 | __cont.erase(__niter_wrap(__cont.begin(), __removed),
|^~~
test.cc:4:15: required from here
4 | std::erase(v, p);
| ~~^~
~/gcc/inst/include/c++/14.0.1/bits/stl_algobase.h:347:30: error: no match for ‘operator-’
(operand types are ‘__gnu_cxx::__normal_iterator > >’ and ‘const void**’)
347 | { return __from + (__res - std::__niter_base(__from)); }
| ~~~^~~~
In file included from ~/gcc/inst/include/c++/14.0.1/bits/stl_algobase.h:67:
~/gcc/inst/include/c++/14.0.1/bits/stl_iterator.h:1148:7: note: candidate: ‘constexpr
__gnu_cxx::__normal_iterator<_Iterator, _Container> __gnu_cxx::__normal_iterator<_Iterator,
_Container>::operator-(difference_type) const [with _Iterator = const void**; _Container =
std::__cxx1998::vector >; difference_type = long
int]’ (near match)
1148 | operator-(difference_type __n) const _GLIBCXX_NOEXCEPT
| ^~~~
~/gcc/inst/include/c++/14.0.1/bits/stl_iterator.h:1148:7: note: conversion of
argument 1 would be ill-formed:
~/gcc/inst/include/c++/14.0.1/bits/stl_algobase.h:347:49: error: invalid conversion from ‘const
void**’ to ‘__gnu_cxx::__normal_iterator > >::difference_type’ {aka ‘long int’} [-fpermissive]
347 | { return __from + (__res - std::__niter_base(__from)); }
|~^~~~
| |
| const void**
~/gcc/inst/include/c++/14.0.1/bits/stl_iterator.h:618:5: note: candidate: ‘template constexpr decltype ((__y.base() - __x.base())) std::operator-(const
reverse_iterator<_IteratorL>&, const reverse_iterator<_IteratorR>&)’
618 | operator-(const reverse_iterator<_IteratorL>& __x,
| ^~~~
~/gcc/inst/include/c++/14.0.1/bits/stl_iterator.h:618:5: note: template
argument deduction/substitution failed:
~/gcc/inst/include/c++/14.0.1/bits/stl_algobase.h:347:30: note:
‘__gnu_cxx::__normal_iterator > >’ is not derived from ‘const
std::reverse_iterator<_IteratorL>’
347 | { return __from + (__res - std::__niter_base(__from)); }
| ~~~^~~~
~/gcc/inst/include/c++/14.0.1/bits/stl_iterator.h:1789:5: note: candidate: ‘template constexpr decltype ((__x.base() - __y.base())) std::operator-(const
move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)’
1789 | operator-(const move_iterator<_IteratorL>& __x,
| ^~~~
~/gcc/inst/include/c++/14.0.1/bits/stl_iterator.h:1789:5: note: template
argument deduction/substitution failed:
~/gcc/inst/include/c++/14.0.1/bits/stl_algobase.h:347:30: note:
‘__gnu_cxx::__normal_iterator > >’ is not derived from ‘const
std::move_iterator<_IteratorL>’
347 | { return __from + (__res - std::__niter_base(__from)); }
| ~~~^~~~
~/gcc/inst/include/c++/14.0.1/bits/stl_iterator.h:1312:5: note: candidate: ‘template constexpr decltype ((__lhs.base() - __rhs.base()))
__gnu_cxx::operator-(const __normal_iterator<_IteratorL, _Container>&, const
__normal_iterator<_IteratorR, _Container>&)’
1312 | operator-(const __normal_iterator<_IteratorL, _Container>& __lhs,
| ^~~~
~/gcc/inst/include/c++/14.0.1/bits/stl_iterator.h:1312:5: note: template
argument deduction/substitution failed:
~/gcc/inst/include/c++/14.0.1/bits/stl_algobase.h:347:30: note: mismatched types
‘const __gnu_cxx::__normal_iterator<_IteratorR, _Container>’ and ‘const void**’
347 | { return __from + (__res - std::__niter_base(__from)); }
| ~~~^~~~
~/gcc/inst/include/c++/14.0.1/bits/stl_iterator.h:1325:5: note: candidate: ‘template constexpr typename __gnu_cxx::__normal_iterator<_Iterator,
Re: [PATCH][_GLIBCXX_DEBUG] Fix std::__niter_base behavior
Thanks for the link, tested and committed.
On 15/02/2024 19:40, Jonathan Wakely wrote:
On Thu, 15 Feb 2024 at 18:38, François Dumont
wrote:
On 15/02/2024 14:17, Jonathan Wakely wrote:
On Wed, 14 Feb 2024 at 21:48, François Dumont
wrote:
On 14/02/2024 20:44, Jonathan Wakely wrote:
On Wed, 14 Feb 2024 at 18:39, François Dumont
wrote:
libstdc++: [_GLIBCXX_DEBUG] Fix std::__niter_base behavior
std::__niter_base is used in _GLIBCXX_DEBUG mode to
remove _Safe_iterator<>
wrapper on random access iterators. But doing so it
should also preserve
original
behavior to remove __normal_iterator wrapper.
libstdc++-v3/ChangeLog:
* include/bits/stl_algobase.h (std::__niter_base):
Redefine the
overload
definitions for __gnu_debug::_Safe_iterator.
* include/debug/safe_iterator.tcc
(std::__niter_base): Adapt
declarations.
Ok to commit once all tests completed (still need to
check pre-c++11) ?
The declaration in include/bits/stl_algobase.h has a
noexcept-specifier but the definition in
include/debug/safe_iterator.tcc does not have one - that
seems wrong (I'm surprised it even compiles).
It does !
The diagnostic is suppressed without -Wsystem-headers:
/home/jwakely/gcc/14/include/c++/14.0.1/debug/safe_iterator.tcc:255:5:warning:
declaration of 'template constexpr
decltype (std::__
niter_base(declval<_Ite>())) std::__niter_base(const
__gnu_debug::_Safe_iterator<_Iterator, _Sequence,
random_access_iterator_tag>&)' has a different except
ion specifier [-Wsystem-headers]
255 | __niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq,
| ^~~~
/home/jwakely/gcc/14/include/c++/14.0.1/bits/stl_algobase.h:335:5:note:
from previous declaration 'template
constexpr decltype (std
::__niter_base(declval<_Ite>())) std::__niter_base(const
__gnu_debug::_Safe_iterator<_Iterator, _Sequence,
random_access_iterator_tag>&) noexcept (noexcept
(is_nothrow_copy_constructible()))>::value))'
335 | __niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq,
| ^~~~
It's a hard error with Clang though:
deb.cc:7:10: error: call to '__niter_base' is ambiguous
Yes, I eventually got the error too, I hadn't run enough tests yet.
I thought it was only necessary at declaration, and I also
had troubles doing it right at definition because of the
interaction with the auto and ->.
The trailing-return-type has to come after the noexcept-specifier.
Now simplified and consistent in this new proposal.
Just using std::is_nothrow_copy_constructible<_Ite> seems
simpler, that will be true for __normal_iterator if
is_nothrow_copy_constructible is true.
Ok
The definition in include/debug/safe_iterator.tcc should use
std::declval<_Ite>() not declval<_Ite>(). Is there any
reason why the definition uses a late-specified-return-type
(i.e. auto and ->) when the declaration doesn't?
I initially plan to use '->
std::decltype(std::__niter_base(__it.base()))' but this did
not compile, ambiguity issue. So I resort to using
std::declval and I could have then done it the same way as
declaration, done now.
Attached is what I'm testing, ok to commit once fully tested ?
OK, thanks.
Thanks for validation but I have a problem to test for c++98.
When I do:
make CXXFLAGS=-std=c++98 check-debug
That doesn't work any more, see
https://gcc.gnu.org/onlinedocs/libstdc++/manual/test.html#test.run.permutations
I see in debug/libstdc++.log for example:
Executing on host: /home/fdumont/dev/gcc/build/./gcc/xg++
-shared-libgcc ... -mshstk -std=c++98 -g -O2 -DLOCALEDIR="."
-nostdinc++ -I/home/fdumont/dev/gcc/...
/home/fdumont/dev/gcc/git/libstdc++-v3/testsuite/25_algorithms/copy/3.cc
-D_GLIBCXX_DEBUG -std=gnu++17 -include bits/stdc++.h ... -lm
-o ./3.exe (timeout = 360)
The -std=c++98 is there but later comes the -std=gnu++17 so I
think it runs in C++17, no ?
I also tried the documented alternative:
make check
'RUNTESTFLAGS=--target_board=unix/-O3\"{-std=gnu++98,-std=gnu++11,-std=gnu++14}\"'
but same problem, -std=gnu++17 comes last.
I'll try to rebuild all from scratch but I won't commit soon then.
Re: [PATCH][_GLIBCXX_DEBUG] Fix std::__niter_base behavior
On Thu, 15 Feb 2024 at 18:38, François Dumont wrote:
>
> On 15/02/2024 14:17, Jonathan Wakely wrote:
>
>
>
> On Wed, 14 Feb 2024 at 21:48, François Dumont
> wrote:
>
>>
>> On 14/02/2024 20:44, Jonathan Wakely wrote:
>>
>>
>>
>> On Wed, 14 Feb 2024 at 18:39, François Dumont
>> wrote:
>>
>>> libstdc++: [_GLIBCXX_DEBUG] Fix std::__niter_base behavior
>>>
>>> std::__niter_base is used in _GLIBCXX_DEBUG mode to remove
>>> _Safe_iterator<>
>>> wrapper on random access iterators. But doing so it should also preserve
>>> original
>>> behavior to remove __normal_iterator wrapper.
>>>
>>> libstdc++-v3/ChangeLog:
>>>
>>> * include/bits/stl_algobase.h (std::__niter_base): Redefine the
>>> overload
>>> definitions for __gnu_debug::_Safe_iterator.
>>> * include/debug/safe_iterator.tcc (std::__niter_base): Adapt
>>> declarations.
>>>
>>> Ok to commit once all tests completed (still need to check pre-c++11) ?
>>>
>>
>>
>> The declaration in include/bits/stl_algobase.h has a noexcept-specifier
>> but the definition in include/debug/safe_iterator.tcc does not have one -
>> that seems wrong (I'm surprised it even compiles).
>>
>> It does !
>>
>
> The diagnostic is suppressed without -Wsystem-headers:
>
> /home/jwakely/gcc/14/include/c++/14.0.1/debug/safe_iterator.tcc:255:5:
> warning:
> declaration of 'template constexpr decltype
> (std::__
> niter_base(declval<_Ite>())) std::__niter_base(const
> __gnu_debug::_Safe_iterator<_Iterator, _Sequence,
> random_access_iterator_tag>&)' has a different except
> ion specifier [-Wsystem-headers]
> 255 | __niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq,
> | ^~~~
> /home/jwakely/gcc/14/include/c++/14.0.1/bits/stl_algobase.h:335:5: note: from
> previous declaration 'template constexpr decltype
> (std
> ::__niter_base(declval<_Ite>())) std::__niter_base(const
> __gnu_debug::_Safe_iterator<_Iterator, _Sequence,
> random_access_iterator_tag>&) noexcept (noexcept
> (is_nothrow_copy_constructible (std::__niter_base(declval<_Ite>()))>::value))'
> 335 | __niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq,
> | ^~~~
>
>
> It's a hard error with Clang though:
>
> deb.cc:7:10: error: call to '__niter_base' is ambiguous
>
>
> Yes, I eventually got the error too, I hadn't run enough tests yet.
>
>
>
>
>
>
>> I thought it was only necessary at declaration, and I also had troubles
>> doing it right at definition because of the interaction with the auto and
>> ->.
>>
>
> The trailing-return-type has to come after the noexcept-specifier.
>
>
>
>> Now simplified and consistent in this new proposal.
>>
>>
>> Just using std::is_nothrow_copy_constructible<_Ite> seems simpler, that
>> will be true for __normal_iterator if
>> is_nothrow_copy_constructible is true.
>>
>> Ok
>>
>>
>> The definition in include/debug/safe_iterator.tcc should use
>> std::declval<_Ite>() not declval<_Ite>(). Is there any reason why the
>> definition uses a late-specified-return-type (i.e. auto and ->) when the
>> declaration doesn't?
>>
>>
>> I initially plan to use '->
>> std::decltype(std::__niter_base(__it.base()))' but this did not compile,
>> ambiguity issue. So I resort to using std::declval and I could have then
>> done it the same way as declaration, done now.
>>
>> Attached is what I'm testing, ok to commit once fully tested ?
>>
>
> OK, thanks.
>
> Thanks for validation but I have a problem to test for c++98.
>
> When I do:
>
> make CXXFLAGS=-std=c++98 check-debug
>
That doesn't work any more, see
https://gcc.gnu.org/onlinedocs/libstdc++/manual/test.html#test.run.permutations
> I see in debug/libstdc++.log for example:
>
> Executing on host: /home/fdumont/dev/gcc/build/./gcc/xg++ -shared-libgcc
> ... -mshstk -std=c++98 -g -O2 -DLOCALEDIR="." -nostdinc++
> -I/home/fdumont/dev/gcc/...
> /home/fdumont/dev/gcc/git/libstdc++-v3/testsuite/25_algorithms/copy/3.cc
> -D_GLIBCXX_DEBUG -std=gnu++17 -include bits/stdc++.h ... -lm -o
> ./3.exe(timeout = 360)
>
> The -std=c++98 is there but later comes the -std=gnu++17 so I think it
> runs in C++17, no ?
>
> I also tried the documented alternative:
>
> make check
> 'RUNTESTFLAGS=--target_board=unix/-O3\"{-std=gnu++98,-std=gnu++11,-std=gnu++14}\"'
>
>
> but same problem, -std=gnu++17 comes last.
>
> I'll try to rebuild all from scratch but I won't commit soon then.
>
>
>
Re: [PATCH][_GLIBCXX_DEBUG] Fix std::__niter_base behavior
On 15/02/2024 14:17, Jonathan Wakely wrote:
On Wed, 14 Feb 2024 at 21:48, François Dumont
wrote:
On 14/02/2024 20:44, Jonathan Wakely wrote:
On Wed, 14 Feb 2024 at 18:39, François Dumont
wrote:
libstdc++: [_GLIBCXX_DEBUG] Fix std::__niter_base behavior
std::__niter_base is used in _GLIBCXX_DEBUG mode to remove
_Safe_iterator<>
wrapper on random access iterators. But doing so it should
also preserve
original
behavior to remove __normal_iterator wrapper.
libstdc++-v3/ChangeLog:
* include/bits/stl_algobase.h (std::__niter_base):
Redefine the
overload
definitions for __gnu_debug::_Safe_iterator.
* include/debug/safe_iterator.tcc (std::__niter_base):
Adapt
declarations.
Ok to commit once all tests completed (still need to check
pre-c++11) ?
The declaration in include/bits/stl_algobase.h has a
noexcept-specifier but the definition in
include/debug/safe_iterator.tcc does not have one - that seems
wrong (I'm surprised it even compiles).
It does !
The diagnostic is suppressed without -Wsystem-headers:
/home/jwakely/gcc/14/include/c++/14.0.1/debug/safe_iterator.tcc:255:5:warning:
declaration of 'template constexpr decltype
(std::__
niter_base(declval<_Ite>())) std::__niter_base(const
__gnu_debug::_Safe_iterator<_Iterator, _Sequence,
random_access_iterator_tag>&)' has a different except
ion specifier [-Wsystem-headers]
255 | __niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq,
| ^~~~
/home/jwakely/gcc/14/include/c++/14.0.1/bits/stl_algobase.h:335:5:note:
from previous declaration 'template constexpr
decltype (std
::__niter_base(declval<_Ite>())) std::__niter_base(const
__gnu_debug::_Safe_iterator<_Iterator, _Sequence,
random_access_iterator_tag>&) noexcept (noexcept
(is_nothrow_copy_constructible(std::__niter_base(declval<_Ite>()))>::value))'
335 | __niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq,
| ^~~~
It's a hard error with Clang though:
deb.cc:7:10: error: call to '__niter_base' is ambiguous
Yes, I eventually got the error too, I hadn't run enough tests yet.
I thought it was only necessary at declaration, and I also had
troubles doing it right at definition because of the interaction
with the auto and ->.
The trailing-return-type has to come after the noexcept-specifier.
Now simplified and consistent in this new proposal.
Just using std::is_nothrow_copy_constructible<_Ite> seems
simpler, that will be true for __normal_iterator if
is_nothrow_copy_constructible is true.
Ok
The definition in include/debug/safe_iterator.tcc should use
std::declval<_Ite>() not declval<_Ite>(). Is there any reason why
the definition uses a late-specified-return-type (i.e. auto and
->) when the declaration doesn't?
I initially plan to use '->
std::decltype(std::__niter_base(__it.base()))' but this did not
compile, ambiguity issue. So I resort to using std::declval and I
could have then done it the same way as declaration, done now.
Attached is what I'm testing, ok to commit once fully tested ?
OK, thanks.
Thanks for validation but I have a problem to test for c++98.
When I do:
make CXXFLAGS=-std=c++98 check-debug
I see in debug/libstdc++.log for example:
Executing on host: /home/fdumont/dev/gcc/build/./gcc/xg++ -shared-libgcc
... -mshstk -std=c++98 -g -O2 -DLOCALEDIR="." -nostdinc++
-I/home/fdumont/dev/gcc/...
/home/fdumont/dev/gcc/git/libstdc++-v3/testsuite/25_algorithms/copy/3.cc
-D_GLIBCXX_DEBUG -std=gnu++17 -include bits/stdc++.h ... -lm -o
./3.exe (timeout = 360)
The -std=c++98 is there but later comes the -std=gnu++17 so I think it
runs in C++17, no ?
I also tried the documented alternative:
make check
'RUNTESTFLAGS=--target_board=unix/-O3\"{-std=gnu++98,-std=gnu++11,-std=gnu++14}\"'
but same problem, -std=gnu++17 comes last.
I'll try to rebuild all from scratch but I won't commit soon then.
Re: [PATCH][_GLIBCXX_DEBUG] Fix std::__niter_base behavior
On Wed, 14 Feb 2024 at 21:48, François Dumont wrote: > > On 14/02/2024 20:44, Jonathan Wakely wrote: > > > > On Wed, 14 Feb 2024 at 18:39, François Dumont > wrote: > >> libstdc++: [_GLIBCXX_DEBUG] Fix std::__niter_base behavior >> >> std::__niter_base is used in _GLIBCXX_DEBUG mode to remove >> _Safe_iterator<> >> wrapper on random access iterators. But doing so it should also preserve >> original >> behavior to remove __normal_iterator wrapper. >> >> libstdc++-v3/ChangeLog: >> >> * include/bits/stl_algobase.h (std::__niter_base): Redefine the >> overload >> definitions for __gnu_debug::_Safe_iterator. >> * include/debug/safe_iterator.tcc (std::__niter_base): Adapt >> declarations. >> >> Ok to commit once all tests completed (still need to check pre-c++11) ? >> > > > The declaration in include/bits/stl_algobase.h has a noexcept-specifier > but the definition in include/debug/safe_iterator.tcc does not have one - > that seems wrong (I'm surprised it even compiles). > > It does ! > The diagnostic is suppressed without -Wsystem-headers: /home/jwakely/gcc/14/include/c++/14.0.1/debug/safe_iterator.tcc:255:5: warning: declaration of 'template constexpr decltype (std::__ niter_base(declval<_Ite>())) std::__niter_base(const __gnu_debug::_Safe_iterator<_Iterator, _Sequence, random_access_iterator_tag>&)' has a different except ion specifier [-Wsystem-headers] 255 | __niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, | ^~~~ /home/jwakely/gcc/14/include/c++/14.0.1/bits/stl_algobase.h:335:5: note: from previous declaration 'template constexpr decltype (std ::__niter_base(declval<_Ite>())) std::__niter_base(const __gnu_debug::_Safe_iterator<_Iterator, _Sequence, random_access_iterator_tag>&) noexcept (noexcept (is_nothrow_copy_constructible()))>::value))' 335 | __niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, | ^~~~ It's a hard error with Clang though: deb.cc:7:10: error: call to '__niter_base' is ambiguous > I thought it was only necessary at declaration, and I also had troubles > doing it right at definition because of the interaction with the auto and > ->. > The trailing-return-type has to come after the noexcept-specifier. > Now simplified and consistent in this new proposal. > > > Just using std::is_nothrow_copy_constructible<_Ite> seems simpler, that > will be true for __normal_iterator if > is_nothrow_copy_constructible is true. > > Ok > > > The definition in include/debug/safe_iterator.tcc should use > std::declval<_Ite>() not declval<_Ite>(). Is there any reason why the > definition uses a late-specified-return-type (i.e. auto and ->) when the > declaration doesn't? > > > I initially plan to use '-> std::decltype(std::__niter_base(__it.base()))' > but this did not compile, ambiguity issue. So I resort to using > std::declval and I could have then done it the same way as declaration, > done now. > > Attached is what I'm testing, ok to commit once fully tested ? > OK, thanks.
Re: [PATCH][_GLIBCXX_DEBUG] Fix std::__niter_base behavior
On 14/02/2024 20:44, Jonathan Wakely wrote:
On Wed, 14 Feb 2024 at 18:39, François Dumont
wrote:
libstdc++: [_GLIBCXX_DEBUG] Fix std::__niter_base behavior
std::__niter_base is used in _GLIBCXX_DEBUG mode to remove
_Safe_iterator<>
wrapper on random access iterators. But doing so it should also
preserve
original
behavior to remove __normal_iterator wrapper.
libstdc++-v3/ChangeLog:
* include/bits/stl_algobase.h (std::__niter_base): Redefine the
overload
definitions for __gnu_debug::_Safe_iterator.
* include/debug/safe_iterator.tcc (std::__niter_base): Adapt
declarations.
Ok to commit once all tests completed (still need to check
pre-c++11) ?
The declaration in include/bits/stl_algobase.h has a
noexcept-specifier but the definition in
include/debug/safe_iterator.tcc does not have one - that seems wrong
(I'm surprised it even compiles).
It does ! I thought it was only necessary at declaration, and I also had
troubles doing it right at definition because of the interaction with
the auto and ->. Now simplified and consistent in this new proposal.
Just using std::is_nothrow_copy_constructible<_Ite> seems simpler,
that will be true for __normal_iterator if
is_nothrow_copy_constructible is true.
Ok
The definition in include/debug/safe_iterator.tcc should use
std::declval<_Ite>() not declval<_Ite>(). Is there any reason why the
definition uses a late-specified-return-type (i.e. auto and ->) when
the declaration doesn't?
I initially plan to use '->
std::decltype(std::__niter_base(__it.base()))' but this did not compile,
ambiguity issue. So I resort to using std::declval and I could have then
done it the same way as declaration, done now.
Attached is what I'm testing, ok to commit once fully tested ?
François
diff --git a/libstdc++-v3/include/bits/stl_algobase.h
b/libstdc++-v3/include/bits/stl_algobase.h
index e7207f67266..0f73da13172 100644
--- a/libstdc++-v3/include/bits/stl_algobase.h
+++ b/libstdc++-v3/include/bits/stl_algobase.h
@@ -317,12 +317,26 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_NOEXCEPT_IF(std::is_nothrow_copy_constructible<_Iterator>::value)
{ return __it; }
+#if __cplusplus < 201103L
template
-_GLIBCXX20_CONSTEXPR
_Ite
__niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq,
std::random_access_iterator_tag>&);
+ template
+_Ite
+__niter_base(const ::__gnu_debug::_Safe_iterator<
+::__gnu_cxx::__normal_iterator<_Ite, _Cont>, _Seq,
+std::random_access_iterator_tag>&);
+#else
+ template
+_GLIBCXX20_CONSTEXPR
+decltype(std::__niter_base(std::declval<_Ite>()))
+__niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq,
+std::random_access_iterator_tag>&)
+noexcept(std::is_nothrow_copy_constructible<_Ite>::value);
+#endif
+
// Reverse the __niter_base transformation to get a
// __normal_iterator back again (this assumes that __normal_iterator
// is only used to wrap random access iterators, like pointers).
diff --git a/libstdc++-v3/include/debug/safe_iterator.tcc
b/libstdc++-v3/include/debug/safe_iterator.tcc
index 6eb70cbda04..a8b24233e85 100644
--- a/libstdc++-v3/include/debug/safe_iterator.tcc
+++ b/libstdc++-v3/include/debug/safe_iterator.tcc
@@ -235,13 +235,29 @@ namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
+#if __cplusplus < 201103L
template
-_GLIBCXX20_CONSTEXPR
_Ite
__niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq,
std::random_access_iterator_tag>& __it)
{ return __it.base(); }
+ template
+_Ite
+__niter_base(const ::__gnu_debug::_Safe_iterator<
+::__gnu_cxx::__normal_iterator<_Ite, _Cont>, _DbgSeq,
+std::random_access_iterator_tag>& __it)
+{ return __it.base().base(); }
+#else
+ template
+_GLIBCXX20_CONSTEXPR
+decltype(std::__niter_base(std::declval<_Ite>()))
+__niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq,
+std::random_access_iterator_tag>& __it)
+noexcept(std::is_nothrow_copy_constructible<_Ite>::value)
+{ return std::__niter_base(__it.base()); }
+#endif
+
template
_GLIBCXX20_CONSTEXPR
Re: [PATCH][_GLIBCXX_DEBUG] Fix std::__niter_base behavior
On Wed, 14 Feb 2024 at 18:39, François Dumont wrote: > libstdc++: [_GLIBCXX_DEBUG] Fix std::__niter_base behavior > > std::__niter_base is used in _GLIBCXX_DEBUG mode to remove _Safe_iterator<> > wrapper on random access iterators. But doing so it should also preserve > original > behavior to remove __normal_iterator wrapper. > > libstdc++-v3/ChangeLog: > > * include/bits/stl_algobase.h (std::__niter_base): Redefine the > overload > definitions for __gnu_debug::_Safe_iterator. > * include/debug/safe_iterator.tcc (std::__niter_base): Adapt > declarations. > > Ok to commit once all tests completed (still need to check pre-c++11) ? > The declaration in include/bits/stl_algobase.h has a noexcept-specifier but the definition in include/debug/safe_iterator.tcc does not have one - that seems wrong (I'm surprised it even compiles). Just using std::is_nothrow_copy_constructible<_Ite> seems simpler, that will be true for __normal_iterator if is_nothrow_copy_constructible is true. The definition in include/debug/safe_iterator.tcc should use std::declval<_Ite>() not declval<_Ite>(). Is there any reason why the definition uses a late-specified-return-type (i.e. auto and ->) when the declaration doesn't?
[PATCH][_GLIBCXX_DEBUG] Fix std::__niter_base behavior
libstdc++: [_GLIBCXX_DEBUG] Fix std::__niter_base behavior
std::__niter_base is used in _GLIBCXX_DEBUG mode to remove _Safe_iterator<>
wrapper on random access iterators. But doing so it should also preserve
original
behavior to remove __normal_iterator wrapper.
libstdc++-v3/ChangeLog:
* include/bits/stl_algobase.h (std::__niter_base): Redefine the
overload
definitions for __gnu_debug::_Safe_iterator.
* include/debug/safe_iterator.tcc (std::__niter_base): Adapt
declarations.
Ok to commit once all tests completed (still need to check pre-c++11) ?
François
diff --git a/libstdc++-v3/include/bits/stl_algobase.h
b/libstdc++-v3/include/bits/stl_algobase.h
index e7207f67266..056fa0c4173 100644
--- a/libstdc++-v3/include/bits/stl_algobase.h
+++ b/libstdc++-v3/include/bits/stl_algobase.h
@@ -317,12 +317,27 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_NOEXCEPT_IF(std::is_nothrow_copy_constructible<_Iterator>::value)
{ return __it; }
+#if __cplusplus < 201103L
template
-_GLIBCXX20_CONSTEXPR
_Ite
__niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq,
std::random_access_iterator_tag>&);
+ template
+_Ite
+__niter_base(const ::__gnu_debug::_Safe_iterator<
+::__gnu_cxx::__normal_iterator<_Ite, _Cont>, _Seq,
+std::random_access_iterator_tag>&);
+#else
+ template
+_GLIBCXX20_CONSTEXPR
+decltype(std::__niter_base(std::declval<_Ite>()))
+__niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq,
+std::random_access_iterator_tag>&)
+noexcept( noexcept(std::is_nothrow_copy_constructible<
+ decltype(std::__niter_base(std::declval<_Ite>()))>::value) );
+#endif
+
// Reverse the __niter_base transformation to get a
// __normal_iterator back again (this assumes that __normal_iterator
// is only used to wrap random access iterators, like pointers).
diff --git a/libstdc++-v3/include/debug/safe_iterator.tcc
b/libstdc++-v3/include/debug/safe_iterator.tcc
index 6eb70cbda04..d6cfe24cc83 100644
--- a/libstdc++-v3/include/debug/safe_iterator.tcc
+++ b/libstdc++-v3/include/debug/safe_iterator.tcc
@@ -235,13 +235,29 @@ namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
+#if __cplusplus < 201103L
template
-_GLIBCXX20_CONSTEXPR
_Ite
__niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq,
std::random_access_iterator_tag>& __it)
{ return __it.base(); }
+ template
+_Ite
+__niter_base(const ::__gnu_debug::_Safe_iterator<
+::__gnu_cxx::__normal_iterator<_Ite, _Cont>, _DbgSeq,
+std::random_access_iterator_tag>& __it)
+{ return __it.base().base(); }
+#else
+ template
+_GLIBCXX20_CONSTEXPR
+auto
+__niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq,
+std::random_access_iterator_tag>& __it)
+-> decltype(std::__niter_base(declval<_Ite>()))
+{ return std::__niter_base(__it.base()); }
+#endif
+
template
_GLIBCXX20_CONSTEXPR
