e I understand the need to page-align data structures in
> some situations, I still don’t see its relevance to a discussion of
> the C standard’s requirements regarding padding in struct types and
> how it’s affected by flexible arrays.
>
>
>
> From: shwaresyst <mailto:shw
roup-l@opengroup.org
Subject: RE: [1003.1(2013)/Issue7+TC1 0000697]: Adding of a getdirentries()
function
That example still has a byte of added padding, or the offsetof would be 5. The
sizeof value is just incorrect, as it assumes one flex member is present. It
should be 5 or 6, and which i
Hallo Jörg.
Joerg Schilling wrote in
<5f4fabb0.NZ6ZB9gXMVdfs/6x%joerg.schill...@fokus.fraunhofer.de>:
|Steffen Nurpmeso via austin-group-l at The Open Group wrote:
|
|> I personally would say that these should be skipped. The data is
|> copied over to user buffers, and these entries are
Philip Guenther via austin-group-l at The Open Group wrote in
:
|On Tue, Sep 1, 2020 at 1:20 PM Steffen Nurpmeso wrote:
|> Philip Guenther wrote in
|> :
|>|On Tue, Sep 1, 2020 at 6:22 AM Steffen Nurpmeso via austin-group-l at The
|>|Open Group wrote:
|>|> Robert Elz via austin-group-l at
t;
Sent: September 1, 2020 2:27 PM
To: Wojtek Lerch mailto:wle...@blackberry.com>>;
austin-group-l@opengroup.org<mailto:austin-group-l@opengroup.org>
Subject: RE: [1003.1(2013)/Issue7+TC1 697]: Adding of a getdirentries()
function
I agree some additional clarity might be u
array is not a VLA, in the sense C uses the term.
From: shwaresyst
Sent: September 1, 2020 4:55 PM
To: Wojtek Lerch ; austin-group-l@opengroup.org
Subject: RE: [1003.1(2013)/Issue7+TC1 697]: Adding of a getdirentries()
function
What that refers to, it looks, is any tail padding
On 2020-09-02 10:34, Joerg Schilling wrote:
Wojtek Lerch via austin-group-l at The Open Group
wrote:
A structure member can be a "flexible array" in standard C, but that's not the
same thing as a VLA.
Are you speaking about array[] in contrast to array[size] with size being a
variable?
Wojtek Lerch via austin-group-l at The Open Group
wrote:
> A structure member can be a "flexible array" in standard C, but that's not
> the same thing as a VLA.
Are you speaking about array[] in contrast to array[size] with size being a
variable?
Jörg
--
EMail:jo...@schily.net
Steffen Nurpmeso via austin-group-l at The Open Group
wrote:
> I personally would say that these should be skipped. The data is
> copied over to user buffers, and these entries are simply not
> copied. That seems to be the best. The Group does not seem to
> want to add DT_WHITEOUT or similar
Steffen Nurpmeso wrote, on 01 Sep 2020:
>
> |Do the existing implementations ever return such things? Do they
> |hide them by making the reclen of the previous entry (if there is
> |one in the buffer) bigger, or do they squash them out, moving the
> |next existing entry down to follow
Philip Guenther wrote, on 01 Sep 2020:
>
> If a posix_getdents() implementation returned the names of all the files
> that ever existed in the given directory, including ones that were removed
> before the fd for this call was opened, what requirement in the standard
> would that violate? I don't
Wojtek Lerch wrote, on 01 Sep 2020:
>
> Geoff Clare wrote:
> > We can't require d_name in struct dirent to be a VLA since there are
> > implementations where it is not.
>
> Another good reason is that standard C does not allow structure members to be
> VLAs.
Mea culpa. I tried to save some
On Tue, Sep 1, 2020 at 1:20 PM Steffen Nurpmeso wrote:
> Philip Guenther wrote in
> :
> |On Tue, Sep 1, 2020 at 6:22 AM Steffen Nurpmeso via austin-group-l at The
> |Open Group wrote:
> |> Robert Elz via austin-group-l at The Open Group wrote in
> |> <9252.1598969...@jinx.noi.kre.to>:
>
No, that is not what I would want nor would anyone else. NAME_MAX doesn't
guarantee no d_name will ever be longer than this value, what it says is all
drivers for file systems provided by the implementation are capable of
processing names up to that length. Some provided may support much
Philip Guenther wrote in
:
|On Tue, Sep 1, 2020 at 6:22 AM Steffen Nurpmeso via austin-group-l at The
|Open Group wrote:
|> Robert Elz via austin-group-l at The Open Group wrote in
|> <9252.1598969...@jinx.noi.kre.to>:
|>|Date:Tue, 1 Sep 2020 10:32:55 +0100
|>|From:
to be page aligned or why you
mention a VLA. A flexible array is not a VLA, in the sense C uses the term.
From: shwaresyst
Sent: September 1, 2020 4:55 PM
To: Wojtek Lerch ; austin-group-l@opengroup.org
Subject: RE: [1003.1(2013)/Issue7+TC1 697]: Adding of a getdirentries()
function
What
shwaresyst wrote in
<1739483391.1543785.1598977118...@mail.yahoo.com>:
|No, it couldn't introduce such a macro, because such would have to \
|assume all d_name entries are the same length. Adding an option to \
Well it has to go for NAME_MAX + the_size_of_posix_dent for each
and every entry,
Wojtek Lerch via austin-group-l at The Open Group wrote in
:
|Geoff Clare wrote:
|> We can't require d_name in struct dirent to be a VLA since there \
|> are implementations where it is not.
|
|Another good reason is that standard C does not allow structure members \
|to be VLAs.
|
|C11
To: Wojtek Lerch ; austin-group-l@opengroup.org
Subject: RE: [1003.1(2013)/Issue7+TC1 697]: Adding of a getdirentries()
function
I agree some additional clarity might be useful there, in the C standard. I'm
reading it as the intent being sizeof is equivalent to offsetof the VLA
On Tue, Sep 1, 2020 at 6:22 AM Steffen Nurpmeso via austin-group-l at The
Open Group wrote:
> Robert Elz via austin-group-l at The Open Group wrote in
> <9252.1598969...@jinx.noi.kre.to>:
> |Date:Tue, 1 Sep 2020 10:32:55 +0100
> |From:"Geoff Clare via austin-group-l at
@opengroup.org>;
austin-group-l@opengroup.org<mailto:austin-group-l@opengroup.org>
Subject: Re: [1003.1(2013)/Issue7+TC1 697]: Adding of a getdirentries()
function
It's my understanding, by C11 6.7.2.1p18, sizeof on a struct with a variable
array works as if the variable member wa
On Tue, Sep 1, 2020 at 5:40 AM Geoff Clare via austin-group-l at The Open
Group wrote:
> > --
> > (0004958) philip-guenther (reporter) - 2020-08-30 23:06
> > https://austingroupbugs.net/view.php?id=6
>
AM
To: g...@opengroup.org; austin-group-l@opengroup.org
Subject: Re: [1003.1(2013)/Issue7+TC1 0000697]: Adding of a getdirentries()
function
It's my understanding, by C11 6.7.2.1p18, sizeof on a struct with a variable
array works as if the variable member was not present, but does count
tin-group-l@opengroup.org
Subject: Re: [1003.1(2013)/Issue7+TC1 697]: Adding of a getdirentries()
function
It's my understanding, by C11 6.7.2.1p18, sizeof on a struct with a variable
array works as if the variable member was not present, but does count any bytes
added for alignment padd
Geoff Clare wrote:
> We can't require d_name in struct dirent to be a VLA since there are
> implementations where it is not.
Another good reason is that standard C does not allow structure members to be
VLAs.
C11 6.7.2.1#9 "A member of a structure or union may have any complete object
type
No, it couldn't introduce such a macro, because such would have to assume all
d_name entries are the same length. Adding an option to the interface to do a
count, as a vararg parameter, and directly malloc the necessary space, returned
via my suggested change to buf as a **, is plausible.
shwaresyst wrote, on 01 Sep 2020:
>
> It's my understanding, by C11 6.7.2.1p18, sizeof on a struct with a variable
> array works as if the variable member was not present
Thanks for the pointer.
So it looks like removing "or equal to" is all that is needed here.
> On Tuesday, September 1,
Geoff Clare via austin-group-l at The Open Group wrote in
<20200901143300.GB24606@localhost>:
|> --
|> (0004953) philip-guenther (reporter) - 2020-08-28 22:52
|> https://www.austingroupbugs.net/view.php?id=697#c4953
|>
Robert Elz via austin-group-l at The Open Group wrote in
<9252.1598969...@jinx.noi.kre.to>:
|Date:Tue, 1 Sep 2020 10:32:55 +0100
|From:"Geoff Clare via austin-group-l at The Open Group" \
|
|Message-ID: <20200901093255.GA7629@localhost>
|
|| but I'm not sure
> --
> (0004958) philip-guenther (reporter) - 2020-08-30 23:06
> https://austingroupbugs.net/view.php?id=697#c4958
> --
> The proposed text includes:
>
> --
> (0004953) philip-guenther (reporter) - 2020-08-28 22:52
> https://www.austingroupbugs.net/view.php?id=697#c4953
> --
> I think the unspecified nature
> --
> (0004949) kre (reporter) - 2020-08-28 17:52
> https://www.austingroupbugs.net/view.php?id=697#c4949
> --
> I suspect that the intent of all of this is
Date:Tue, 1 Sep 2020 10:32:55 +0100
From:"Geoff Clare via austin-group-l at The Open Group"
Message-ID: <20200901093255.GA7629@localhost>
| but I'm not sure how useful this would be to applications. In any case
| it would be highly unusual for an application
Per Mildner wrote, on 30 Aug 2020:
>
> The posix_getdents() function shall ... place ... posix_dent structures in
> the buffer pointed to by buf up to a maximum of nbyte bytes"
> "The array d_name ... shall contain a filename of at most {NAME_MAX} bytes
> followed by a terminating null byte."
The posix_getdents() function shall ... place ... posix_dent structures in the
buffer pointed to by buf up to a maximum of nbyte bytes"
"The array d_name ... shall contain a filename of at most {NAME_MAX} bytes
followed by a terminating null byte." (so could need up to {NAME_MAX} + 1
bytes).
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