Linux: add our own headers for system call numbers.

Linux: add our own headers for system call numbers.


BUG=
NOTRY=true

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=150390

[jln (very slow on Chromium), 2012-08-07 18:34:00]

This is a small CL to add our own headers to define system call numbers.

I have generated them automatically from the Linux kernel sources.

[Markus (顧孟勤), 2012-08-07 18:36:50]

lgtm

[Jorge Lucangeli Obes, 2012-08-07 18:38:06]

On 2012/08/07 18:36:50, Markus (顧孟勤) wrote:
> lgtm

Adding automatically-generated files that no-one else can recreate seems like a
bad idea.

[jln (very slow on Chromium), 2012-08-07 18:42:38]

On 2012/08/07 18:38:06, Jorge Lucangeli Obes wrote:
> On 2012/08/07 18:36:50, Markus (顧孟勤) wrote:
> > lgtm
> 
> Adding automatically-generated files that no-one else can recreate seems like
a
> bad idea.

Why couldn't anyone else recreate them ? I clearly indicate the source files to
do so (syscall_32.tbl / syscall_64.tbl in the Linux kernel source). They are
trivial to re-create, and (most likely what will be needed), trivial to updates
since new system calls are added incrementally.

Julien

[Markus (顧孟勤), 2012-08-07 18:48:30]

I am with Julien here. If you want to recreate them, you can a) use sed, b)
use an ad-hoc keyboard macro in your editor of choice, or c) type them
manually. It'll take a whole 3 minutes :-)


Markus

On Tue, Aug 7, 2012 at 11:42 AM, <jln@chromium.org> wrote:

> On 2012/08/07 18:38:06, Jorge Lucangeli Obes wrote:
>
>> On 2012/08/07 18:36:50, Markus (顧孟勤) wrote:
>> > lgtm
>>
>
>  Adding automatically-generated files that no-one else can recreate seems
>> like
>>
> a
>
>> bad idea.
>>
>
> Why couldn't anyone else recreate them ? I clearly indicate the source
> files to
> do so (syscall_32.tbl / syscall_64.tbl in the Linux kernel source). They
> are
> trivial to re-create, and (most likely what will be needed), trivial to
> updates
> since new system calls are added incrementally.
>
> Julien
>
>
https://chromiumcodereview.**appspot.com/10825227/<https://chromiumcodereview...
>

[Jorge Lucangeli Obes, 2012-08-07 19:07:56]

On 2012/08/07 18:48:30, Markus (顧孟勤) wrote:
> I am with Julien here. If you want to recreate them, you can a) use sed, b)
> use an ad-hoc keyboard macro in your editor of choice, or c) type them
> manually. It'll take a whole 3 minutes :-)

The fact that the mechanism (script) is so simple is exactly the reason why it
should be included as a comment in the code. It doesn't matter if it takes 3
minutes or 30, if a file is generated automatically, it should be self-contained
and re-creatable.

We have the same thing in Minijail in Chrome OS and we have a sed script in the
Makefile.

> On Tue, Aug 7, 2012 at 11:42 AM, <mailto:jln@chromium.org> wrote:
> 
> > On 2012/08/07 18:38:06, Jorge Lucangeli Obes wrote:
> >
> >> On 2012/08/07 18:36:50, Markus (顧孟勤) wrote:
> >> > lgtm
> >>
> >
> >  Adding automatically-generated files that no-one else can recreate seems
> >> like
> >>
> > a
> >
> >> bad idea.
> >>
> >
> > Why couldn't anyone else recreate them ? I clearly indicate the source
> > files to
> > do so (syscall_32.tbl / syscall_64.tbl in the Linux kernel source). They
> > are
> > trivial to re-create, and (most likely what will be needed), trivial to
> > updates
> > since new system calls are added incrementally.
> >
> > Julien
> >
> >
>
https://chromiumcodereview.**appspot.com/10825227/%3Chttps://chromiumcoderevi...>
> >

[jln (very slow on Chromium), 2012-08-07 19:14:00]

On 2012/08/07 19:07:56, Jorge Lucangeli Obes wrote:
> On 2012/08/07 18:48:30, Markus (顧孟勤) wrote:
> > I am with Julien here. If you want to recreate them, you can a) use sed, b)
> > use an ad-hoc keyboard macro in your editor of choice, or c) type them
> > manually. It'll take a whole 3 minutes :-)
> 
> The fact that the mechanism (script) is so simple is exactly the reason why it
> should be included as a comment in the code. It doesn't matter if it takes 3
> minutes or 30, if a file is generated automatically, it should be
self-contained
> and re-creatable.

Forget that they are auto generated if you wish. What's important is that now,
instead of adding new syscall in an ad-hoc way into various .cc files as people
do know, one can add them to these files. They most likely would do that
manually.

If at some point someone want to include syscall_32.tbl / syscall_64.tbl here
(and figure out the licensing restrictions because they may be likely GPL), and
modify the GYP files so that those headers file are automatically generated,
they should feel free to do so.

What matters is that this CL is a net improvement over what happens at the
moment: people adding #define in .cc files manually and breaking the build
because some build bots have more outdated headers than others.

[jln (very slow on Chromium), 2012-08-07 19:25:03]

On 2012/08/07 19:14:00, Julien Tinnes wrote:
> On 2012/08/07 19:07:56, Jorge Lucangeli Obes wrote:
> > On 2012/08/07 18:48:30, Markus (顧孟勤) wrote:
> > > I am with Julien here. If you want to recreate them, you can a) use sed,
b)
> > > use an ad-hoc keyboard macro in your editor of choice, or c) type them
> > > manually. It'll take a whole 3 minutes :-)
> > 
> > The fact that the mechanism (script) is so simple is exactly the reason why
it
> > should be included as a comment in the code. It doesn't matter if it takes 3
> > minutes or 30, if a file is generated automatically, it should be
> self-contained
> > and re-creatable.
> 
> Forget that they are auto generated if you wish. What's important is that now,
> instead of adding new syscall in an ad-hoc way into various .cc files as
people
> do know, one can add them to these files. They most likely would do that
> manually.
> 
> If at some point someone want to include syscall_32.tbl / syscall_64.tbl here
> (and figure out the licensing restrictions because they may be likely GPL),
and
> modify the GYP files so that those headers file are automatically generated,
> they should feel free to do so.
> 
> What matters is that this CL is a net improvement over what happens at the
> moment: people adding #define in .cc files manually and breaking the build
> because some build bots have more outdated headers than others.

I spoke to Jorge, he's not thrilled, but not mortally offended either if I
commit it.
I'll commit it, but we may want to improve on this CL later.

[commit-bot: I haz the power, 2012-08-07 19:25:27]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/jln@chromium.org/10825227/1

[commit-bot: I haz the power, 2012-08-07 19:25:44]

Change committed as 150390