• f (9/9) Sep 10 void main()
• f (1/1) Sep 10 i mean , is this a bug?
• Jonathan M Davis (29/30) Sep 10 No, it's not a bug. Assertions with an expression that is known to be fa...
• ryuukk_ (6/10) Sep 11 It is a bug, don't claim it is not, the compiler gives the wrong
• Nick Treleaven (4/8) Sep 11 The behaviour is by design, it is not a bug, it is documented in
• ryuukk_ (7/16) Sep 11 Oh right, "illegal instruction" is what users should read in
• Kapendev (3/20) Sep 11 You can say that the error message is weird with -release, but
• user1234 (3/10) Sep 12 Oh no please stay, your unrecognisable passive aggressive style
• Andy Valencia (10/21) Sep 12 To put it more gently, ryuukk--and following the generally
• Fox (3/3) Sep 11 I don't care about whether it's a bug or not, I just want to
• Bradley Chatha (3/6) Sep 11 Fortunately Godbolt supports D, so it's easy to see that it
• Fox (3/9) Sep 11 This is great, thanks.
• Salih Dincer (6/7) Sep 12 This is not a bug. The problem is due to a misunderstanding of

f <f abc.com> writes:

void main()
{
assert(false);
}

dmd -release a.d

dmd version 2.109.1
debian bookworm x64

illegal instruction

thanks

f <f abc.com> writes:

i mean , is this a bug?

Jonathan M Davis <newsgroup.d jmdavisprog.com> writes:

On Tuesday, September 10, 2024 10:01:53 PM MDT f via Digitalmars-d-learn 
wrote:
 i mean , is this a bug?

No, it's not a bug. Assertions with an expression that is known to be false
at compile time are treated as special. They are always left in the
generated code so that they will kill your program if you ever hit that line
of code.

So, assertions which actually need to be validated at runtime will be
compiled out with -release, but assert(false) is always there, and with
-release, instead of throwing an AssertError, it immediately terminates the
program.

One common use case for this would be something like

auto foo(int i) nothrow
{
    try
    {
        ...
    }
    catch(Exception)
    {
        assert(false, "It should be impossible for this code to throw.");
    }
}

where you have code that you know will never throw given the input that
you're giving it, but it's not nothrow, because it could throw under other
circumstances. And so in order to call that code within a nothrow function,
you wrap it in a try-catch block, and then just in case you screwed up, and
it does somehow throw, the assertion is triggered even with -release, and
your program is terminated instead of continuing in an invalid state.

- Jonathan M Davis

ryuukk_ <ryuukk.dev gmail.com> writes:

On Wednesday, 11 September 2024 at 06:07:26 UTC, Jonathan M Davis 
wrote:
 On Tuesday, September 10, 2024 10:01:53 PM MDT f via 
 Digitalmars-d-learn wrote:
 i mean , is this a bug?

 No, it's not a bug.


It is a bug, don't claim it is not, the compiler gives the wrong 
information, wich lead to a confused user

You don't want confused users, you want compiler say what's up, 
if i type assert, it should assert, end of the story

Nick Treleaven <nick geany.org> writes:

On Wednesday, 11 September 2024 at 08:08:45 UTC, ryuukk_ wrote:
 It is a bug, don't claim it is not, the compiler gives the 
 wrong information, wich lead to a confused user

 You don't want confused users, you want compiler say what's up, 
 if i type assert, it should assert, end of the story

The behaviour is by design, it is not a bug, it is documented in 
the spec:
https://dlang.org/spec/expression.html#assert-ct

ryuukk_ <ryuukk.dev gmail.com> writes:

On Wednesday, 11 September 2024 at 09:14:39 UTC, Nick Treleaven 
wrote:
 On Wednesday, 11 September 2024 at 08:08:45 UTC, ryuukk_ wrote:
 It is a bug, don't claim it is not, the compiler gives the 
 wrong information, wich lead to a confused user

 You don't want confused users, you want compiler say what's 
 up, if i type assert, it should assert, end of the story

 The behaviour is by design, it is not a bug, it is documented 
 in the spec:
 https://dlang.org/spec/expression.html#assert-ct


Oh right, "illegal instruction" is what users should read in 
order to "fix" their code

I again apologies for being wrong and i apologies again for 
trying to improve things, i didn't meant to do that, i now may 
leave again

Kapendev <alexandroskapretsos gmail.com> writes:

On Wednesday, 11 September 2024 at 10:08:29 UTC, ryuukk_ wrote:
 On Wednesday, 11 September 2024 at 09:14:39 UTC, Nick Treleaven 
 wrote:
 On Wednesday, 11 September 2024 at 08:08:45 UTC, ryuukk_ wrote:
 It is a bug, don't claim it is not, the compiler gives the 
 wrong information, wich lead to a confused user

 You don't want confused users, you want compiler say what's 
 up, if i type assert, it should assert, end of the story

 The behaviour is by design, it is not a bug, it is documented 
 in the spec:
 https://dlang.org/spec/expression.html#assert-ct


 Oh right, "illegal instruction" is what users should read in 
 order to "fix" their code

 I again apologies for being wrong and i apologies again for 
 trying to improve things, i didn't meant to do that, i now may 
 leave again

You can say that the error message is weird with -release, but 
it's not a bug.

user1234 <user1234 12.de> writes:

On Wednesday, 11 September 2024 at 10:08:29 UTC, ryuukk_ wrote:
 On Wednesday, 11 September 2024 at 09:14:39 UTC, Nick Treleaven 
 wrote:
 On Wednesday, 11 September 2024 at 08:08:45 UTC, ryuukk_ wrote:

 [...]
 I again apologies for being wrong and i apologies again for 
 trying to improve things, i didn't meant to do that, i now may 
 leave again

Oh no please stay, your unrecognisable passive aggressive style 
is so useful.

Andy Valencia <dont spam.me> writes:

On Thursday, 12 September 2024 at 22:34:04 UTC, user1234 wrote:
 On Wednesday, 11 September 2024 at 10:08:29 UTC, ryuukk_ wrote:
 On Wednesday, 11 September 2024 at 09:14:39 UTC, Nick 
 Treleaven wrote:
 On Wednesday, 11 September 2024 at 08:08:45 UTC, ryuukk_ 
 wrote:

 [...]
 I again apologies for being wrong and i apologies again for 
 trying to improve things, i didn't meant to do that, i now may 
 leave again

 Oh no please stay, your unrecognisable passive aggressive style 
 is so useful.

To put it more gently, ryuukk--and following the generally 
congenial and informative flavor of communications here--you may 
not realize that your messages have an abrasive feel to them.  It 
really does make a difference to be polite and even respectful 
when people seek to help you by answering your questions.  
Showing gratitude makes it much more likely that these valuable 
contributors stay around and answer newbie questions in the 
future.

Andy

Fox <linuxl4 sohu.com> writes:

I don't care about whether it's a bug or not,  I just want to 
learn What illegal instructions did this "assert(false);" code 
create?

Bradley Chatha <sealabjaster gmail.com> writes:

On Wednesday, 11 September 2024 at 12:17:02 UTC, Fox wrote:
 I don't care about whether it's a bug or not,  I just want to 
 learn What illegal instructions did this "assert(false);" code 
 create?

Fortunately Godbolt supports D, so it's easy to see that it 
generates `ud2` on x86(_64): https://godbolt.org/z/4zq67boMW

Fox <linuxl4 sohu.com> writes:

On Wednesday, 11 September 2024 at 16:40:05 UTC, Bradley Chatha 
wrote:
 On Wednesday, 11 September 2024 at 12:17:02 UTC, Fox wrote:
 I don't care about whether it's a bug or not,  I just want to 
 learn What illegal instructions did this "assert(false);" code 
 create?

 Fortunately Godbolt supports D, so it's easy to see that it 
 generates `ud2` on x86(_64): https://godbolt.org/z/4zq67boMW

This is great, thanks.

Salih Dincer <salihdb hotmail.com> writes:

On Wednesday, 11 September 2024 at 04:01:53 UTC, f wrote:
 i mean , is this a bug?

This is not a bug. The problem is due to a misunderstanding of 
the -release parameter. The following related topic opened by 
Steven and the answers given by Walter are really valuable: 
https://forum.dlang.org/thread/pkeasakdbugctqdyetnw forum.dlang.org

SDB 79