llvm dev - Oct 2020 - Clang 3.9.1 fails to build LLVM 11.0.0

Hi folks. It’s my first time in this mailing list, and definitely not
the last :)

Recently, I’ve been into bootstrapping compilers. I’ve encountered
several issues, and will start with this one.

The doc claims that Clang >= 3.5 is required to build LLVM 11.0.0 [1].
So I built LLVM+Clang 3.9.1, then tried to build LLVM 11.0.0. Doing so,
I faced this error:
> no matching constructor for initialization of
> 'llvm::ValueEnumerator::MDRange'
(full log here [2])

Don’t worry, I’ve done my job. For a minimal reproducible example, here
[3] is a script that you should execute on a new Debian 10 system, most
likely a VM.

[1]
https://releases.llvm.org/11.0.0/docs/GettingStarted.html#host-c-toolchain-both-compiler-and-standard-library
[2]
https://gist.github.com/concatime/6b5b9bcbc91a74b2913234180a29c159#file-log-txt
[3]
https://gist.github.com/concatime/6b5b9bcbc91a74b2913234180a29c159#file-build-sh

Issam E.

PS: a feedback too about how I report bugs would be awesome!

Not sure we would call that a bug. Looks more like a minor documentation 
change to a more recent clang version. I wonder which version that is.

Neil Nelson

On 10/26/20 12:20 PM, Issam E. Maghni via llvm-dev
wrote:
> Hi folks. It’s my first time in this mailing list, and definitely not
> the last :)
>
> Recently, I’ve been into bootstrapping compilers. I’ve encountered
> several issues, and will start with this one.
>
> The doc claims that Clang >= 3.5 is required to build LLVM 11.0.0 [1].
> So I built LLVM+Clang 3.9.1, then tried to build LLVM 11.0.0. Doing so,
> I faced this error:
>> no matching constructor for initialization of
>> 'llvm::ValueEnumerator::MDRange'
> (full log here [2])
>
> Don’t worry, I’ve done my job. For a minimal reproducible example, here
> [3] is a script that you should execute on a new Debian 10 system, most
> likely a VM.
>
> [1]
>
https://releases.llvm.org/11.0.0/docs/GettingStarted.html#host-c-toolchain-both-compiler-and-standard-library
> [2]
>
https://gist.github.com/concatime/6b5b9bcbc91a74b2913234180a29c159#file-log-txt
> [3]
>
https://gist.github.com/concatime/6b5b9bcbc91a74b2913234180a29c159#file-build-sh
>
> Issam E.
>
> PS: a feedback too about how I report bugs would be awesome!
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
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When we upped our ‘required compiler’ version we were VERY explicit about making
sure we set our support matrix accordingly.  All of those host compiler versions
came after nearly a year of extended debates.

I WOULD expect it to compile with everything from 3.5 and newer, though I don’t
know what buildbots we have in place to ensure that is the case.

I do note that this is a bit of a strange bug that I haven’t been able to
minimally-reproduce on Godbolt.  Presumably this https://godbolt.org/z/xd1f4E is
a pretty close minimization of this, and it doesn’t reproduce.  For some reason
(despite the line-numbers matching what is in the LLVM 11.0 release), it doesn’t
seem to be considering line 100 of ValueEnumerator.h, the defaulted default
constructor.

Issam: Can you confirm that your copy of ValueEnumerator.h
(/root/llvm-project-llvmorg-11.0.0/llvm/lib/Bitcode/Writer/ValueEnumerator.h) 
line 100 is     MDRange() = default;
?

As for bugs, you can go to bugs.llvm.org to report defects, though the signup
has a manual process required by one of the admins due to spam.

From: llvm-dev <llvm-dev-bounces at lists.llvm.org> On Behalf Of Neil
Nelson via llvm-dev
Sent: Monday, October 26, 2020 11:42 AM
To: llvm-dev at lists.llvm.org
Subject: Re: [llvm-dev] Clang 3.9.1 fails to build LLVM 11.0.0


Not sure we would call that a bug. Looks more like a minor documentation change
to a more recent clang version. I wonder which version that is.

Neil Nelson
On 10/26/20 12:20 PM, Issam E. Maghni via llvm-dev wrote:

Hi folks. It’s my first time in this mailing list, and definitely not

the last :)



Recently, I’ve been into bootstrapping compilers. I’ve encountered

several issues, and will start with this one.



The doc claims that Clang >= 3.5 is required to build LLVM 11.0.0 [1].

So I built LLVM+Clang 3.9.1, then tried to build LLVM 11.0.0. Doing so,

I faced this error:

no matching constructor for initialization of

'llvm::ValueEnumerator::MDRange'

(full log here [2])



Don’t worry, I’ve done my job. For a minimal reproducible example, here

[3] is a script that you should execute on a new Debian 10 system, most

likely a VM.



[1]

https://releases.llvm.org/11.0.0/docs/GettingStarted.html#host-c-toolchain-both-compiler-and-standard-library

[2]

https://gist.github.com/concatime/6b5b9bcbc91a74b2913234180a29c159#file-log-txt

[3]

https://gist.github.com/concatime/6b5b9bcbc91a74b2913234180a29c159#file-build-sh



Issam E.



PS: a feedback too about how I report bugs would be awesome!

_______________________________________________

LLVM Developers mailing list

llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>

https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
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I also found out that this issue happens in 10.0.1 and 10.0.0, but not
in 9.0.1. I added these versions in my build script. Ideally, this issue
would be patched for 11.0.1. Still wondering how this was not detected
before..