On 11 January 2012 00:46, Esteban Lorenzano estebanlm@gmail.com wrote:

hi  Sean,

gcc is still there... but is not the default anymore :) also... I don't know how much time they are going to maintain it... and how much that will affect us :(

so, that means that at some point we should start investigating the problem why it doesn't works when compiled using llvm? i expecting a great adventure ahead :)

best, Esteban

El 10/01/2012, a las 8:38p.m., Sean P. DeNigris escribió:

...

In Xcode 4.2, the choices are:  1) Apple LLVM 3.0, and  2) LLVM gcc 4.2

#2 seems to work okay...

-- View this message in context: http://forum.world.st/Xcode-no-longer-includes-gcc-tp4283855p4283855.html Sent from the Squeak VM mailing list archive at Nabble.com.

At the Apple Developer conference in 2009 the nice Apple LLVM folks told me, can we have a "small" code sample that shows the problem... Fails on the old interpreter from that era, you should start with that, you don't actually need to step "too much" in order to get it to die btw.

On Tue, Jan 10, 2012 at 8:16 PM, Sean P. DeNigris sean@clipperadams.comwrote:

EstebanLM wrote

...

gcc is still there...

Not with a fresh install of Xcode 4.2! See

http://ask.metafilter.com/200231/How-to-install-gcc-42-on-a-macbook-with-Xco...

I was able to get it and fix Xcode:

1. install via Mac Ports: "sudo port install apple-gcc42"
2. Follow http://stackoverflow.com/a/8593831/424245 to get it to appear in

Xcode, the last two steps will probably look like: a) sudo ln -s /opt/local/bin/gcc-apple-4.2 /Developer/usr/bin/gcc-4.2 b) sudo ln -s /opt/local/bin/g++-apple-4.2 /Developer/usr/bin/g++-4.2

-- View this message in context: http://forum.world.st/Xcode-no-longer-includes-gcc-tp4283855p4284100.html Sent from the Squeak VM mailing list archive at Nabble.com.

On Wed, Jan 11, 2012 at 08:25:14AM +0100, Stefan Marr wrote:

Hi:

Most of the things you'll find are undefined behavior in C.

I posted at least one issue to the list (I think it had to do with overflow in one of the arithmetic primitives, multiplication or so).

Indeed that was in interesting catch. The thread is here: http://lists.squeakfoundation.org/pipermail/vm-dev/2011-July/008913.html

It was added to an existing Mantis issue at: http://bugs.squeak.org/view.php?id=6987

And a fix was hopefully applied here:

Name: VMMaker-dtl.245 Author: dtl Time: 2 August 2011, 7:11:17.088 am Ancestors: VMMaker-dtl.244

VMMaker 4.7.2

Reference http://lists.squeakfoundation.org/pipermail/vm-dev/2011-August/009006.html Fix NewObjectMemory>>newObjectHash to use shiftForWord rather than bytesPerWord (check to ensure corresponding fix in oscog).

Reference Mantis 6987: signed32BitValueOf:, signed64BitValueOf: etc. broken Discussion at http://lists.squeakfoundation.org/pipermail/vm-dev/2011-July/008905.html

Fix #signed32BitValueOf: and #signed64BitValueOf: which are reported broken for some optimizing C compilers. Cast to unsigned integer to prevent undefined behavior on arithmetic overflow.

Add InterpreterPrimitivesTest to provide some coverage of #signed64BitValueOf:

Follow up required - Test to verify fix on problematic compilers. Merge with oscog.

It seems quite likely that other problems like this exist in the VM, particularly in the slang generated code that tends to be a bit casual when it come to type declarations.

If porting to LLVM helps flush out some more issues like this, that would be a good thing :)

Dave

My strategy to fix these things for the RoarVM was to use a bytecode trace, output to a file. And you have to make sure that you got as few as possible non-determinism. For that I disabled preemptive scheduling completely.

Afterwards I had two VMs, one compiled with GCC, and one with Clang. And then fixed the issues as they popped up.

Takes a bit, but it is possible. The trace usually points at the bytecodes that behave incorrectly.

Hope that helps. Stefan

On 11 Jan 2012, at 02:22, John McIntosh wrote:

...

At the Apple Developer conference in 2009 the nice Apple LLVM folks told me, can we have a "small" code sample that shows the problem... Fails on the old interpreter from that era, you should start with that, you don't actually need to step "too much" in order to get it to die btw.

On Tue, Jan 10, 2012 at 8:16 PM, Sean P. DeNigris sean@clipperadams.com wrote:

EstebanLM wrote

...

gcc is still there...

Not with a fresh install of Xcode 4.2! See http://ask.metafilter.com/200231/How-to-install-gcc-42-on-a-macbook-with-Xco...

I was able to get it and fix Xcode:

1. install via Mac Ports: "sudo port install apple-gcc42"
2. Follow http://stackoverflow.com/a/8593831/424245 to get it to appear in

Xcode, the last two steps will probably look like: a) sudo ln -s /opt/local/bin/gcc-apple-4.2 /Developer/usr/bin/gcc-4.2 b) sudo ln -s /opt/local/bin/g++-apple-4.2 /Developer/usr/bin/g++-4.2

-- View this message in context: http://forum.world.st/Xcode-no-longer-includes-gcc-tp4283855p4284100.html Sent from the Squeak VM mailing list archive at Nabble.com.

--

John M. McIntosh johnmci@smalltalkconsulting.com Corporate Smalltalk Consulting Ltd. http://www.smalltalkconsulting.com ===========================================================================

-- Stefan Marr Software Languages Lab Vrije Universiteit Brussel Pleinlaan 2 / B-1050 Brussels / Belgium http://soft.vub.ac.be/~smarr Phone: +32 2 629 2974 Fax: +32 2 629 3525

Hi:

On 11 Jan 2012, at 17:38, Sean P. DeNigris wrote:

Sean P. DeNigris wrote

...

I was able to get it and fix Xcode:

To put all the info in one place, I wrote a blog post: http://seandenigris.com/blog/?p=931

Our experience shows that an update from Snow Leopard to Lion seems to delete the old gcc-4.2 binaries. You might want to add that detail.

However, while I can't check it, the binaries might not have been deleted but just moved out of the search path, see: http://superuser.com/questions/313107/does-updating-to-os-x-lion-delete-gcc

Best regards Stefan