Hi Cyrille, On 13 February 2018 at 09:38, Cyrille Delaunay <cy.delaunay@gmail.com> wrote:
Hi everyone,
With last answers from Eliot and Alistair, I understand that using a ""GCC 5 VM" may solve the issue. Am I right ?
After posting about using gcc 5 I started getting weird results which make me wonder if something was wrong during my last testing. Stuart saw the problem on BSD compiled with clang. I assume that gcc and clang are independent enough that it suggests it isn't a gcc issue. But it needs proper investigation.
I am willing to give a try on mac os and check if the issue show up with such a vm. But where can I download such a vm ?
I think you'd have to compile your own VM at the moment. Cheers, Alistair
2018-01-23 9:24 GMT+01:00 Alistair Grant <akgrant0710@gmail.com>:
Hi Eliot,
On 23 January 2018 at 01:47, Eliot Miranda <eliot.miranda@gmail.com> wrote:
Hi Alistair,
On Mon, Jan 22, 2018 at 1:42 AM, Alistair Grant <akgrant0710@gmail.com> wrote:
Hi Eliot,
On Sat, Jan 20, 2018 at 09:19:04AM +0100, Alistair Grant wrote:
Hi Eliot,
On 19 January 2018 at 23:04, Eliot Miranda <eliot.miranda@gmail.com> wrote:
Hi Alistair, Hi Cl??ment,
On Fri, Jan 19, 2018 at 12:53 PM, Alistair Grant <akgrant0710@gmail.com> wrote:
Hi Cl??ment,
On 19 January 2018 at 17:21, Alistair Grant <akgrant0710@gmail.com> wrote:
Hi Cl??ment,
On 19 January 2018 at 17:04, Cl??ment Bera <bera.clement@gmail.com> wrote:
Does not seem to be related to prim 105.
I suspect that the problem is the same compactor bug I've been trying to reproduce all week, and have just fixed. Could you try and reproduce with a VM built from the latest commit?
Happy to, but I'm out all day today, so it will be tomorrow or Monday.
Cheers, Alistair (on the run...)
I've tested this with 2 images and 3 VMs in all 6 combinations:
- "Old VM": commit date: Wed Jan 10 23:39:30 2018 -0800, gcc 4.8.5 - "New VM": commit date: Sat Jan 20 13:52:26 2018 +0100, gcc 4.8.5 - "GCC 5 VM": commit date: Sat Jan 20 13:52:26 2018 +0100, gcc 5.4.0 - Clean image: commit id: b28d466f - Work image: commit id: eb0a6fb1
The gcc 5 is only there because I was playing with it. The results may be useful, or completely misleading. :-)
Each time I ran "5 timesRepeat: [ self test4 ]" with the halts replaced with a count increment. test4 is the method provided in Cyrille's original message.
Result summary:
- Old VM + Work image: 5, 5, 5, 0, 0 - Old VM + Clean image: 5, 5, 0, 0, 0 - New VM + Work image: 5, 0, 5, 5, 5 - New VM + Clean image: 0, 0, 1, 5, 5 - GCC 5 + Work image: 0, 0, 0, 0, 0 - GCC 5 + Clean image: 0, 0, 0, 0, 0
This is strong evidence for the issue being a compiler bug with 4.8.x If exactly the same input source for the Vm wrks with gcc 5 but not with 4.8.x then there is a small chance it is due to the Vm relying on undefined behavior, but I doubt it. Assuming it is a gcc bug then - it should be documented in the HowToBuild files for the relevant platforms - Ci builds should start using gcc 5 and dispense with gcc 4.8.x - since the problem is fixed with gcc 5 there seems little point trying to identify which version of gcc introduces the problem and communicating the problem to the gcc maintainers
What's the status of the bug on Windows and Mac OS X?
I can't check MacOS. Clement?
I get the problem on Windows (version info below).
Note that Max Leske and I have been using gcc 4.8 because of a problem with OSProcess and gcc 5 (it possibly doesn't affect me anymore, I'm currently using OSSubprocess). See:
http://lists.squeakfoundation.org/pipermail/vm-dev/2017-May/025216.html
I'll try and confirm correct OSSubprocess operation with gcc 5, but it will take a while, I'm battling too many different problems at the moment:
- TZ and DST handling on Windows - Windows VM suddenly can't find any of its plugins. Is anyone else seeing strange behaviour here with VMs from the last few days? -- It looks like the plugin handling mechanism is completely different on Windows to Unix, so the VM doesn't report where it is looking and doesn't provide the option to specify the directory. Grrrrrgh. - My linux build environment. - real life :-)
Windows version info:
OS: Windows 10 Image: Pharo 7.0 Build information: Pharo-7.0+alpha.build.439.sha.481071068244d0484241924f79ba791f80701316 (32 Bit) VM: Win32 built on Nov 27 2017 00:05:44 GMT Compiler: 6.4.0 [Production Spur VM] CoInterpreter VMMaker.oscog- nice.2281 uuid: 4beeaee7-567e-1a4b-b0fb-bd95ce302516 Nov 27 2017 StackToRegisterMappingCogit VMMaker.oscog-nice.2283 uuid: 2d20324d-a2ab-48d6-b0f6-9fc3d66899da Nov 27 2017 VM: 201711262336 https://github.com/OpenSmalltalk/opensmalltalk-vm.git $ Date: Mon Nov 27 00:36:29 2017 +0100 $ Plugins: 201711262336 https://github.com/OpenSmalltalk/opensmalltalk-vm.git $
Cheers, Alistair
-- Cyrille Delaunay