Re: FreeBSD / libobj2 issue after update - all apps crash

[David Chisnall]

On 05/06/2019 05:30, Riccardo Mottola wrote:
> Hi,
>
>
> David Chisnall wrote:
> > On 04/06/2019 09:46, Riccardo Mottola wrote:
> > > Hi David,
> > >
> > > David Chisnall wrote:
> > > > Thanks for the report.  Please can you file an issue on GitHub? This 
> > > > is a quite surprising error - it implies that either clang has a bug 
> > > > or that something is trying to manually create or modify protocols 
> > > > without calling through the runtime.  This might happen if you have 
> > > > a version of GNUstep compiled against the gcc runtime and using 
> > > > ObjectiveC2.framework instead of the runtime's public APIs, but that 
> > > > shouldn't be the case with the packaged versions.
> > >
> > > clang and libobjc2 are packaged, however gnustep installation is 
> > > compiled by my by current sources. I did not do anything special, I 
> > > configured make with:
> > >
> > > $ ./configure --prefix=/ --with-layout=gnustep 
> > > CFLAGS=-I/usr/local/include
> >
> > Are you using -make from packages, which will be configured to use the 
> > new ABI?
>
>
> no, I am using everyghing from git HEAD of our repositories, including 
> latest gnustep make.
> Do you pass some special configuration parameters when packaging? I can 
> attempt that.

All of the configuration parameters that I use for the packages are in 
the port Makefile(s).  I do build everything with the ng library combo 
though.

> > Okay, this is not one that will be used by -make from packages, 
> > because it doesn't support the 2.0 ABI.  Please use the clang from the 
> > llvm7 or lllv8 package, or from the base system in 12.  It looks as if 
> > you're using the old (GCC) ABI, which may mean that you've linked in 
> > the ObjectiveC2 framework and are explicitly constructing internal 
> > runtime data structures from an old version of the runtime.  Please 
> > can you check where the invalid protocol is coming from?  It may also 
> > be something that we're failing to correctly upgrade when using the 
> > legacy ABI.
>
> Ok, so it is an older compiler, but should not the runtime support it? 
> there are no two libobjc2 packages, or is libobjc2 no longer compatible 
> with the GCC runtime?
>
> How can I check for the protocol? It is coming "from inside GNUstep" 
> since I just installed core packages and then am running Ink, so there 
> is no custom code of mine.
> Maybe we just have some issue in gnustep which we didn't discover.

Can you do a backtrace of where the crash is?  What is the protocol that 
it's inspecting while crashing?

> When you say "upgrade" are you referring to FreeBSD package upgrade or 
> GNUstep ?

The 2.x runtime series uses a new set of internal structures.  It 
transparently upgrades all old runtime structures to the new layout 
(there may be places where this fails, if so they are bugs - please 
report them with test cases in the GitHub issue tracker).  The runtime 
has not for a long time supported external code generating these 
structures, as the ObjectiveC2 framework does when used with an old 
runtime, and provides public APIs for creating and modifying them so 
that they can be opaque to user code.  With the 1.x series, this all 
probably mostly worked, because things were upgraded lazily where 
necessary, not on load.  That complicated the runtime internals a lot 
and the 2.x series is a lot cleaner, but will definitely break if used 
with code that expects to poke runtime data structures and expects them 
to have the GCC runtime layouts.

> Indeed, on another computer where I am running FreeBSD 12 instead, 
> everything worked out of the box.

Hopefully that's picking up the 8.x compiler and everything is the new ABI.

David