<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">I was able to successfully build with r194701, so I have reapplied that along with the compiler-rt changes. Somehow we need to get to the bottom of the problem. If you can reproduce it, please help!!<div><br><div><div>On Nov 14, 2013, at 11:01 PM, Eric Christopher <<a href="mailto:echristo@gmail.com">echristo@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><p dir="ltr">Yes. I'm seeing this as well and it predates Kostya's change. Shows up as memory corruption or double free on Linux. </p>
<div class="gmail_quote">On Nov 14, 2013 10:46 PM, "Alexey Samsonov" <<a href="mailto:samsonov@google.com">samsonov@google.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">FYI I've seen what looked like a memory corruption in (private) Clang bootstrap process long before Kostya's changes were submitted. I hope I'll have the chance to investigate it soon.</div><div class="gmail_extra">
<br><br><div class="gmail_quote">On Fri, Nov 15, 2013 at 10:20 AM, Bob Wilson <span dir="ltr"><<a href="mailto:bob.wilson@apple.com" target="_blank">bob.wilson@apple.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
I don’t know yet, but I will let you know as soon as I can.<br>
<div><br>
On Nov 14, 2013, at 10:18 PM, Kostya Serebryany <<a href="mailto:kcc@google.com" target="_blank">kcc@google.com</a>> wrote:<br>
<br>
> On Fri, Nov 15, 2013 at 10:16 AM, Bob Wilson <<a href="mailto:bob.wilson@apple.com" target="_blank">bob.wilson@apple.com</a>> wrote:<br>
>> No, not that I am aware of.<br>
><br>
> So, if my commits did indeed trigger the failures it could be<br>
> something like binary size change that caused different code alignment<br>
> or some such<br>
> and which triggered a latent memory bug somewhere else.<br>
><br>
> It's already late evening for you now. Will you have a chance to<br>
> reapply changes today?<br>
><br>
> --kcc<br>
><br>
>><br>
>> On Nov 14, 2013, at 10:15 PM, Kostya Serebryany <<a href="mailto:kcc@google.com" target="_blank">kcc@google.com</a>> wrote:<br>
>><br>
>>> On Fri, Nov 15, 2013 at 10:14 AM, Bob Wilson <<a href="mailto:bob.wilson@apple.com" target="_blank">bob.wilson@apple.com</a>> wrote:<br>
>>>> The bit code file produced by the stage 1 compiler for one of the files in the clang driver is corrupt and causes the linker for stage 2 to crash.<br>
>>><br>
>>> Is AddressSanitizer involved in any of the stages of the LTO build?<br>
>>><br>
>>>><br>
>>>> On Nov 14, 2013, at 10:13 PM, Kostya Serebryany <<a href="mailto:kcc@google.com" target="_blank">kcc@google.com</a>> wrote:<br>
>>>><br>
>>>>> What are the symptoms?<br>
>>>>><br>
>>>>> On Fri, Nov 15, 2013 at 9:37 AM, Bob Wilson <<a href="mailto:bob.wilson@apple.com" target="_blank">bob.wilson@apple.com</a>> wrote:<br>
>>>>>> I’m waiting to see if this fixes the buildbots. Unfortunately, because they were failing all day, there are a bunch of other regressions that have come up, and I’m still working through them. It takes quite a while to run a bootstrapped LTO clang build, so it will take a while longer.<br>
>>>>>><br>
>>>>>> I don’t have any other useful information at this point, and I share your puzzlement about how your changes could possibly break the compiler. My only hypothesis is some sort of memory corruption.<br>
>>>>>><br>
>>>>>> I will keep you posted.<br>
>>>>>><br>
>>>>>> On Nov 14, 2013, at 9:22 PM, Kostya Serebryany <<a href="mailto:kcc@google.com" target="_blank">kcc@google.com</a>> wrote:<br>
>>>>>><br>
>>>>>>> Also, when are you planing to "reapply the changes or help debug"?<br>
>>>>>>><br>
>>>>>>> On Fri, Nov 15, 2013 at 9:15 AM, Kostya Serebryany <<a href="mailto:kcc@google.com" target="_blank">kcc@google.com</a>> wrote:<br>
>>>>>>>> On Fri, Nov 15, 2013 at 7:26 AM, Bob Wilson <<a href="mailto:bob.wilson@apple.com" target="_blank">bob.wilson@apple.com</a>> wrote:<br>
>>>>>>>>> Hi Kostya,<br>
>>>>>>>>><br>
>>>>>>>>> Thanks for the heads-up on this. I haven’t had a chance to look into the<br>
>>>>>>>>> details yet, but it looks like these patches may be breaking our<br>
>>>>>>>>> bootstrapped LTO build. Our buildbots have been failing all day, and we’re<br>
>>>>>>>>> still trying to figure out the problem. I’m going to speculatively revert<br>
>>>>>>>>> those changes, since they were the only patches on the buildbot blame list.<br>
>>>>>>>>> I will either reapply the changes or help debug the problem.<br>
>>>>>>>><br>
>>>>>>>> How could this possibly affect your LTO build?<br>
>>>>>>>> The option is off by default.<br>
>>>>>>>> Do you have any details, logs, etc?<br>
>>>>>>>><br>
>>>>>>>>><br>
>>>>>>>>> —Bob<br>
>>>>>>>>><br>
>>>>>>>>> On Nov 14, 2013, at 5:42 AM, Kostya Serebryany <<a href="mailto:kcc@google.com" target="_blank">kcc@google.com</a>> wrote:<br>
>>>>>>>>><br>
>>>>>>>>> Bob, Justin,<br>
>>>>>>>>><br>
>>>>>>>>> I've just committed a poor man's coverage implementation that works with<br>
>>>>>>>>> asan.<br>
>>>>>>>>> <a href="http://llvm.org/viewvc/llvm-project?rev=194701&view=rev" target="_blank">http://llvm.org/viewvc/llvm-project?rev=194701&view=rev</a><br>
>>>>>>>>> <a href="http://llvm.org/viewvc/llvm-project?rev=194702&view=rev" target="_blank">http://llvm.org/viewvc/llvm-project?rev=194702&view=rev</a><br>
>>>>>>>>> It provides only function-level boolean coverage (i.e. no counters, just<br>
>>>>>>>>> "visited or not"),<br>
>>>>>>>>> but is very fast and very simple (no extra sections to the binary file, etc)<br>
>>>>>>>>> I've tried it for Chrome's content_shell (huge and heavy binary) and the<br>
>>>>>>>>> overhead<br>
>>>>>>>>> is negligible at both run-time and shutdown-time.<br>
>>>>>>>>><br>
>>>>>>>>> We'll be evaluating this implementation and collecting usage stats.<br>
>>>>>>>>> Maybe we want to implement something simple like this in the Clang coverage.<br>
>>>>>>>>><br>
>>>>>>>>> --kcc<br>
>>>>>>>>><br>
>>>>>>>>><br>
>>>>>><br>
>>>><br>
>><br>
<br>
<br>
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</div></blockquote></div><br><br clear="all"><div><br></div>-- <br><div>Alexey Samsonov, MSK</div>
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