[libcxx-commits] [PATCH] D101206: [libc++] Remove UB in list, forward_list and __hash_table

[Michael Buch via Phabricator via libcxx-commits]

Michael137 added a comment.

In D101206#4653303 <https://reviews.llvm.org/D101206#4653303>, @dblaikie wrote:

> In D101206#4653253 <https://reviews.llvm.org/D101206#4653253>, @Michael137 wrote:
>
>> Looks like this broke the LLDB buildbot on Darwin: https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/61029/console
>>
>> Specifically the formatters:
>>
>>   Failed Tests (2):
>>     lldb-api :: commands/expression/import-std-module/queue/TestQueueFromStdModule.py
>>     lldb-api :: functionalities/data-formatter/data-formatter-stl/generic/unordered/TestDataFormatterGenericUnordered.py
>>
>>   AssertionError: Ran command:
>>   "frame variable map"
>>   
>>   Got output:
>>   (std::unordered_map<int, std::string>) map = size=5 {}
>>   
>>   Expecting regex pattern: "std::unordered_map" (was found, matched "std::unordered_map")
>>   Expecting regex pattern: "\[0\] = \{\s*first = " (was not found)
>>
>> Presumably because we removed the `_LIBCPP_STANDALONE_DEBUG`. I don't think we do constructor homing on Darwin since we do `-fstandalone-debug`
>
> Adding/removing the attribute shouldn't make any difference on Darwin. (the standalone debug attribute says "treat this type as though it were compiled with `-fstandalone-debug`" and Darwin's default is `-fstandalone-debug` - so adding/removing the attribute shouldn't change the behavior - it's possible there are bugs here, but I'd wager that's not the case/is a red herring)

Good point, though I did confirm that this patch caused the breakage.
Reason I pointed it at the attribute was following error:

  error: warning: warning: got name from symbols: C
  error: Couldn't look up symbols:
    __ZNSt3__19__voidifyB7v180000INS_11__list_nodeI1CPvEEEES3_RT_

Which on first glance sounds like a "lack of debug info" problem. Though your point makes sense, it shouldn't affect Darwin since it's already the default. Will investigate what else it could be


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  https://reviews.llvm.org/D101206/new/

https://reviews.llvm.org/D101206