<div dir="ltr"><p class="">Hello,</p>
<p class=""> Yeah
you are right Mikhail, thanks for pointing it out, I must ask, is there any bug
already logged for this issue ? </p>
<p class="">Ravi</p></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Nov 16, 2015 at 5:24 PM, Mikhail Filimonov via lldb-dev <span dir="ltr"><<a href="mailto:lldb-dev@lists.llvm.org" target="_blank">lldb-dev@lists.llvm.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<p class="MsoNormal">Hi guys and thank you for the excellent community project!<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Recently I’ve stumbled on a pesky, but trivial Invalid iterator dereference bug in SymbolContext and TypeMap implementations at revisions<u></u><u></u></p>
<p class="MsoNormal"><a href="https://github.com/llvm-mirror/lldb/blob/e528da256d14ecac7df858462b44dca931879509/source/Symbol/SymbolContext.cpp#L823" target="_blank">https://github.com/llvm-mirror/lldb/blob/e528da256d14ecac7df858462b44dca931879509/source/Symbol/SymbolContext.cpp#L823</a><u></u><u></u></p>
<p class="MsoNormal">and<u></u><u></u></p>
<p class="MsoNormal"><a href="https://github.com/llvm-mirror/lldb/blob/5ac1fc5bc961688505334395598a2bb174eabd3b/source/Symbol/TypeMap.cpp#L172" target="_blank">https://github.com/llvm-mirror/lldb/blob/5ac1fc5bc961688505334395598a2bb174eabd3b/source/Symbol/TypeMap.cpp#L172</a><u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">From the code below it is obvious that TypeMap::ForEach calls the pre-increment operator on m_types iterator right after it has been invalidated by m_types.erase<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">SymbolContext::SortTypeList(TypeMap &type_map, TypeList &type_list ) const<u></u><u></u></p>
<p class="MsoNormal">{<u></u><u></u></p>
<p class="MsoNormal"> TypeMaptoList callbackM2L (type_map, type_list);<u></u><u></u></p>
<p class="MsoNormal"> type_map.ForEach(callbackM2L);<u></u><u></u></p>
<p class="MsoNormal"> return ;<u></u><u></u></p>
<p class="MsoNormal">}<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">void<u></u><u></u></p>
<p class="MsoNormal">TypeMap::ForEach (std::function <bool(lldb::TypeSP &type_sp)> const &callback)<u></u><u></u></p>
<p class="MsoNormal">{<u></u><u></u></p>
<p class="MsoNormal"> for (auto pos = m_types.begin(), end = m_types.end(); pos != end; ++pos)<u></u><u></u></p>
<p class="MsoNormal"> {<u></u><u></u></p>
<p class="MsoNormal"> if (!callback(pos->second))<u></u><u></u></p>
<p class="MsoNormal"> break;<u></u><u></u></p>
<p class="MsoNormal"> }<u></u><u></u></p>
<p class="MsoNormal">}<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">bool<u></u><u></u></p>
<p class="MsoNormal">TypeMap::RemoveTypeWithUID (user_id_t uid)<u></u><u></u></p>
<p class="MsoNormal">{<u></u><u></u></p>
<p class="MsoNormal"> iterator pos = m_types.find(uid);<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal"> if (pos != m_types.end())<u></u><u></u></p>
<p class="MsoNormal"> {<u></u><u></u></p>
<p class="MsoNormal"> m_types.erase(pos);<u></u><u></u></p>
<p class="MsoNormal"> return true;<u></u><u></u></p>
<p class="MsoNormal"> }<u></u><u></u></p>
<p class="MsoNormal"> return false;<u></u><u></u></p>
<p class="MsoNormal">}<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">class TypeMaptoList<u></u><u></u></p>
<p class="MsoNormal">{<u></u><u></u></p>
<p class="MsoNormal">public:<u></u><u></u></p>
<p class="MsoNormal"> TypeMaptoList(TypeMap &typem, TypeList &typel) :<u></u><u></u></p>
<p class="MsoNormal"> type_map(typem),type_list(typel)<u></u><u></u></p>
<p class="MsoNormal"> {<u></u><u></u></p>
<p class="MsoNormal"> }<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"> bool<u></u><u></u></p>
<p class="MsoNormal"> operator() (const lldb::TypeSP& type)<u></u><u></u></p>
<p class="MsoNormal"> {<u></u><u></u></p>
<p class="MsoNormal"> if(type)<u></u><u></u></p>
<p class="MsoNormal"> {<u></u><u></u></p>
<p class="MsoNormal"> type_list.Insert(type);<u></u><u></u></p>
<p class="MsoNormal"> type_map.RemoveTypeWithUID(type->GetID());<u></u><u></u></p>
<p class="MsoNormal"> if (type_map.Empty())<u></u><u></u></p>
<p class="MsoNormal"> return false;<u></u><u></u></p>
<p class="MsoNormal"> }<u></u><u></u></p>
<p class="MsoNormal"> return true;<u></u><u></u></p>
<p class="MsoNormal"> }<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">private:<u></u><u></u></p>
<p class="MsoNormal"> TypeMap &type_map;<u></u><u></u></p>
<p class="MsoNormal"> TypeList &type_list;<u></u><u></u></p>
<p class="MsoNormal">};<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Regards,<u></u><u></u></p>
<p class="MsoNormal">Mikhail Filimonov<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
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