[clangd-dev] [cfe-dev] Random non-reproducible errors in ClangdTests
Ilya Biryukov via clangd-dev
clangd-dev at lists.llvm.org
Thu Sep 6 04:58:55 PDT 2018
The TSAN logs were produced with non-sanitized standard library, I couldn't
reproduce the failures with a sanitized build of libc++.
Please check if r341538 fixes the error, there is a good chance it was the
root cause.
If it doesn't help, please let us know, we'll investigate further.
On Thu, Sep 6, 2018 at 1:40 PM Ilya Biryukov <ibiryukov at google.com> wrote:
> There was a data race in another test, fixed in r341538.
> Might be causing these failures, but I couldn't reproduce the original
> ones, so can't be sure.
>
> On Thu, Sep 6, 2018 at 1:01 PM Ilya Biryukov <ibiryukov at google.com> wrote:
>
>> Thanks for the logs. Will take a look.
>>
>> On Thu, Sep 6, 2018 at 12:36 PM Kirill Bobyrev <kbobyrev.lists at gmail.com>
>> wrote:
>>
>>> Thanks for the information!
>>>
>>> I was able to reproduce many failures in tests using TSan and MSan. I'm
>>> attaching logs for TSan for this particular test that was originally
>>> mentioned (WorkspaceSymbolsTest.Namespaces): it looks like a data race in
>>> Trace and TUScheduler. The pattern looks to be the same for all other tests.
>>>
>>> +CC Ilya who is knowledgeable about TUScheduler.
>>>
>>> I will attach stdout logs of the test failure and whole TSan output.
>>>
>>> Kind regards,
>>> Kirill
>>>
>>> thread-sanitizer.logs
>>> <https://drive.google.com/file/d/1D51ldaFyZgJrqugmLlCnIoCe1EsetRC2/view?usp=drive_web>
>>>
>>>
>>> On Thu, Sep 6, 2018 at 7:54 AM Mikael Holmén <mikael.holmen at ericsson.com>
>>> wrote:
>>>
>>>> Hi,
>>>>
>>>> On 09/05/2018 10:55 PM, Kirill Bobyrev via cfe-dev wrote:
>>>> > Hi Mikael,
>>>> >
>>>> > Thanks for pointing that out! Could you share information about what
>>>> > compiler + system you used to build and run tests?
>>>>
>>>> I've seen the failures when compiling with clang 3.6.0 on RHEL 6.9 as
>>>> well as gcc 5.4.0 on SLED 11.2.
>>>>
>>>> The valgrind run was made on a binary compiled with clang 3.6.0 on
>>>> Ubuntu 14.04.
>>>>
>>>> > Sometimes, UB is
>>>> > relatively easy to reproduce using the same setup.
>>>> >
>>>> > As Mehmet mentioned, it looks that there might be uninitialised
>>>> variable
>>>> > given the Valgrind log that you provided.
>>>> >
>>>> > Could you please attach the whole log so that it would be easier for
>>>> us
>>>> > to understand the cause of problem(s)?
>>>>
>>>> Sure!
>>>>
>>>> Thanks,
>>>> Mikael
>>>>
>>>> >
>>>> > +clangd-dev
>>>> >
>>>> > Kind regards,
>>>> > Kirill
>>>> >
>>>> >> On 5 Sep 2018, at 17:39, Mehmet Erol Sanliturk via cfe-dev
>>>> >> <cfe-dev at lists.llvm.org <mailto:cfe-dev at lists.llvm.org>> wrote:
>>>> >>
>>>> >>
>>>> >>
>>>> >> On Wed, Sep 5, 2018 at 4:19 PM, Mikael Holmén via
>>>> >> cfe-dev<cfe-dev at lists.llvm.org <mailto:cfe-dev at lists.llvm.org
>>>> >>wrote:
>>>> >>
>>>> >> Hi,
>>>> >>
>>>> >> For a while now we randomly see failures when running the
>>>> >> ClangdTests test.
>>>> >>
>>>> >> E.g the below but sometimes other failures:
>>>> >>
>>>> >> --------
>>>> >> FAIL: Extra Tools Unit Tests ::
>>>> >> clangd/./ClangdTests/WorkspaceSymbolsTest.Namespaces (16172 of
>>>> 39758)
>>>> >> ******************** TEST 'Extra Tools Unit Tests ::
>>>> >> clangd/./ClangdTests/WorkspaceSymbolsTest.Namespaces' FAILED
>>>> >> ********************
>>>> >> Note: Google Test filter = WorkspaceSymbolsTest.Namespaces
>>>> >> [==========] Running 1 test from 1 test case.
>>>> >> [----------] Global test environment set-up.
>>>> >> [----------] 1 test from WorkspaceSymbolsTest
>>>> >> [ RUN ] WorkspaceSymbolsTest.Namespaces
>>>> >>
>>>> ../tools/clang/tools/extra/unittests/clangd/FindSymbolsTests.cpp:151:
>>>> >> Failure
>>>> >> Value of: getSymbols("a")
>>>> >> Expected: has 4 elements and there exists some permutation of
>>>> >> elements such that:
>>>> >> - element #0 (named "ans1") and (in container ""), and
>>>> >> - element #1 (named "ai1") and (in container "ans1"), and
>>>> >> - element #2 (named "ans2") and (in container "ans1"), and
>>>> >> - element #3 (named "ai2") and (in container "ans1::ans2")
>>>> >> Actual: {}
>>>> >>
>>>> ../tools/clang/tools/extra/unittests/clangd/FindSymbolsTests.cpp:153:
>>>> >> Failure
>>>> >> Value of: getSymbols("::")
>>>> >> Expected: has 1 element that (named "ans1") and (in container "")
>>>> >> Actual: {}
>>>> >>
>>>> ../tools/clang/tools/extra/unittests/clangd/FindSymbolsTests.cpp:155:
>>>> >> Failure
>>>> >> Value of: getSymbols("::a")
>>>> >> Expected: has 1 element that (named "ans1") and (in container "")
>>>> >> Actual: {}
>>>> >>
>>>> ../tools/clang/tools/extra/unittests/clangd/FindSymbolsTests.cpp:158:
>>>> >> Failure
>>>> >> Value of: getSymbols("ans1::")
>>>> >> Expected: has 2 elements and there exists some permutation of
>>>> >> elements such that:
>>>> >> - element #0 (named "ai1") and (in container "ans1"), and
>>>> >> - element #1 (named "ans2") and (in container "ans1")
>>>> >> Actual: {}
>>>> >>
>>>> ../tools/clang/tools/extra/unittests/clangd/FindSymbolsTests.cpp:160:
>>>> >> Failure
>>>> >> Value of: getSymbols("::ans1")
>>>> >> Expected: has 1 element that (named "ans1") and (in container "")
>>>> >> Actual: {}
>>>> >>
>>>> ../tools/clang/tools/extra/unittests/clangd/FindSymbolsTests.cpp:163:
>>>> >> Failure
>>>> >> Value of: getSymbols("::ans1::")
>>>> >> Expected: has 2 elements and there exists some permutation of
>>>> >> elements such that:
>>>> >> - element #0 (named "ai1") and (in container "ans1"), and
>>>> >> - element #1 (named "ans2") and (in container "ans1")
>>>> >> Actual: {}
>>>> >>
>>>> ../tools/clang/tools/extra/unittests/clangd/FindSymbolsTests.cpp:165:
>>>> >> Failure
>>>> >> Value of: getSymbols("::ans1::ans2")
>>>> >> Expected: has 1 element that (named "ans2") and (in container
>>>> "ans1")
>>>> >> Actual: {}
>>>> >>
>>>> ../tools/clang/tools/extra/unittests/clangd/FindSymbolsTests.cpp:167:
>>>> >> Failure
>>>> >> Value of: getSymbols("::ans1::ans2::")
>>>> >> Expected: has 1 element that (named "ai2") and (in container
>>>> >> "ans1::ans2")
>>>> >> Actual: {}
>>>> >> [ FAILED ] WorkspaceSymbolsTest.Namespaces (39 ms)
>>>> >> [----------] 1 test from WorkspaceSymbolsTest (39 ms total)
>>>> >>
>>>> >> [----------] Global test environment tear-down
>>>> >> [==========] 1 test from 1 test case ran. (40 ms total)
>>>> >> [ PASSED ] 0 tests.
>>>> >> [ FAILED ] 1 test, listed below:
>>>> >> [ FAILED ] WorkspaceSymbolsTest.Namespaces
>>>> >>
>>>> >> 1 FAILED TEST
>>>> >>
>>>> >>
>>>> >> It can fail and then at once pass again so something funny is
>>>> >> going on.
>>>> >>
>>>> >>
>>>> >> I ran valgrind on ClangdTests and then I got a bunch of
>>>> >> complaints, the first being:
>>>> >>
>>>> >>
>>>> >> [ RUN ] ClangdVFSTest.SearchLibDir
>>>> >> Updating file /clangd-test/foo.cpp with command [/clangd-test]
>>>> >> clang -ffreestanding -xc++ -target x86_64-linux-unknown -m64
>>>> >> --gcc-toolchain=/randomusr -stdlib=libstdc++ /clangd-test/foo.cpp
>>>> >>
>>>> -resource-dir=/data/repo/llvm-patch/build-all/tools/clang/tools/extra/unittests/clangd/../lib/clang/8.0.0
>>>> >> Preamble for file /clangd-test/foo.cpp cannot be reused.
>>>> >> Attempting to rebuild it.
>>>> >> Built preamble of size 175020 for file /clangd-test/foo.cpp
>>>> >> ==14605== Thread 2 worker:foo.cpp:
>>>> >> ==14605== Conditional jump or move depends on uninitialised
>>>> value(s)
>>>> >> ==14605== at 0xCDF8A6:
>>>> >> clang::Sema::SetCtorInitializers(clang::CXXConstructorDecl*,
>>>> bool,
>>>> >> llvm::ArrayRef<clang::CXXCtorInitializer*>) (in
>>>> >>
>>>> /data/repo/llvm-patch/build-all/tools/clang/tools/extra/unittests/clangd/ClangdTests)
>>>> >> ==14605== by 0xD01CB9:
>>>> >>
>>>> clang::Sema::DefineImplicitDefaultConstructor(clang::SourceLocation,
>>>> >> clang::CXXConstructorDecl*) (in
>>>> >>
>>>> /data/repo/llvm-patch/build-all/tools/clang/tools/extra/unittests/clangd/ClangdTests)
>>>> >> ==14605== by 0xEA3B93:
>>>> >> PerformConstructorInitialization(clang::Sema&,
>>>> >> clang::InitializedEntity const&, clang::InitializationKind
>>>> const&,
>>>> >> llvm::MutableArrayRef<clang::Expr*>,
>>>> >> clang::InitializationSequence::Step const&, bool&, bool, bool,
>>>> >> clang::SourceLocation, clang::SourceLocation) (in
>>>> >>
>>>> /data/repo/llvm-patch/build-all/tools/clang/tools/extra/unittests/clangd/ClangdTests)
>>>> >> ==14605== by 0xE9AA3F:
>>>> >> clang::InitializationSequence::Perform(clang::Sema&,
>>>> >> clang::InitializedEntity const&, clang::InitializationKind
>>>> const&,
>>>> >> llvm::MutableArrayRef<clang::Expr*>, clang::QualType*) (in
>>>> >>
>>>> /data/repo/llvm-patch/build-all/tools/clang/tools/extra/unittests/clangd/ClangdTests)
>>>> >> ==14605== by 0xBFA3C4:
>>>> >> clang::Sema::ActOnUninitializedDecl(clang::Decl*) (in
>>>> >>
>>>> /data/repo/llvm-patch/build-all/tools/clang/tools/extra/unittests/clangd/ClangdTests)
>>>> >> ==14605== by 0x13C5EFF:
>>>> >>
>>>> clang::Parser::ParseDeclarationAfterDeclaratorAndAttributes(clang::Declarator&,
>>>> >> clang::Parser::ParsedTemplateInfo const&,
>>>> >> clang::Parser::ForRangeInit*) (in
>>>> >>
>>>> /data/repo/llvm-patch/build-all/tools/clang/tools/extra/unittests/clangd/ClangdTests)
>>>> >> ==14605== by 0x13C40B7:
>>>> >> clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&,
>>>> >> clang::DeclaratorContext, clang::SourceLocation*,
>>>> >> clang::Parser::ForRangeInit*) (in
>>>> >>
>>>> /data/repo/llvm-patch/build-all/tools/clang/tools/extra/unittests/clangd/ClangdTests)
>>>> >> ==14605== by 0x13AAF5B:
>>>> >>
>>>> clang::Parser::ParseDeclOrFunctionDefInternal(clang::Parser::ParsedAttributesWithRange&,
>>>> >> clang::ParsingDeclSpec&, clang::AccessSpecifier) (in
>>>> >>
>>>> /data/repo/llvm-patch/build-all/tools/clang/tools/extra/unittests/clangd/ClangdTests)
>>>> >> ==14605== by 0x13AAA1D:
>>>> >>
>>>> clang::Parser::ParseDeclarationOrFunctionDefinition(clang::Parser::ParsedAttributesWithRange&,
>>>> >> clang::ParsingDeclSpec*, clang::AccessSpecifier) (in
>>>> >>
>>>> /data/repo/llvm-patch/build-all/tools/clang/tools/extra/unittests/clangd/ClangdTests)
>>>> >> ==14605== by 0x13A9861:
>>>> >>
>>>> clang::Parser::ParseExternalDeclaration(clang::Parser::ParsedAttributesWithRange&,
>>>> >> clang::ParsingDeclSpec*) (in
>>>> >>
>>>> /data/repo/llvm-patch/build-all/tools/clang/tools/extra/unittests/clangd/ClangdTests)
>>>> >> ==14605== by 0x13A8629:
>>>> >>
>>>> clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&)
>>>> >> (in
>>>> >>
>>>> /data/repo/llvm-patch/build-all/tools/clang/tools/extra/unittests/clangd/ClangdTests)
>>>> >> ==14605== by 0x13A840F:
>>>> >>
>>>> clang::Parser::ParseFirstTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&)
>>>> >> (in
>>>> >>
>>>> /data/repo/llvm-patch/build-all/tools/clang/tools/extra/unittests/clangd/ClangdTests)
>>>> >> ==14605==
>>>> >> Updating file /clangd-test/foo.cpp with command [/clangd-test]
>>>> >> clang -ffreestanding -xc++ -target x86_64-linux-unknown -m64
>>>> >> --gcc-toolchain=/randomusr -stdlib=libstdc++ /clangd-test/foo.cpp
>>>> >>
>>>> -resource-dir=/data/repo/llvm-patch/build-all/tools/clang/tools/extra/unittests/clangd/../lib/clang/8.0.0
>>>> >> Reusing preamble for file /clangd-test/foo.cpp
>>>> >> [ OK ] ClangdVFSTest.SearchLibDir (952 ms)
>>>> >>
>>>> >>
>>>> >>
>>>> >> It's not obvious to me what the problem really is. Does anyone
>>>> >> here have a clue?
>>>> >>
>>>> >> Regards,
>>>> >> Mikael
>>>> >> _______________________________________________
>>>> >>
>>>> >>
>>>> >>
>>>> >>
>>>> >>
>>>> >> One reason of non-reproducible errors in a program is mainly
>>>> >> "uninitialized variables" .
>>>> >> These variables uses whatever remains in the memory from previous
>>>> >> allocations and used by the new program .
>>>> >> Therefore when these values are used , program behavior is
>>>> unexpected .
>>>> >>
>>>> >>
>>>> >> Another may be "array index showing outside of an array" .
>>>> Especially
>>>> >> in loops , if loop passes array boundaries toward up or down .
>>>> >> Or , when a value is directly used to index an array , but it is out
>>>> >> of bounds .
>>>> >>
>>>> >>
>>>> >> The above reasons are not , "all" , but "some" .
>>>> >>
>>>> >>
>>>> >>
>>>> >>
>>>> >> Mehmet Erol Sanliturk
>>>> >>
>>>> >>
>>>> >>
>>>> >>
>>>> >>
>>>> >> _______________________________________________
>>>> >> cfe-dev mailing list
>>>> >> cfe-dev at lists.llvm.org <mailto:cfe-dev at lists.llvm.org>
>>>> >> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev
>>>> >
>>>> >
>>>> >
>>>> > _______________________________________________
>>>> > cfe-dev mailing list
>>>> > cfe-dev at lists.llvm.org
>>>> > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev
>>>> >
>>>>
>>>
>>
>> --
>> Regards,
>> Ilya Biryukov
>>
>
>
> --
> Regards,
> Ilya Biryukov
>
--
Regards,
Ilya Biryukov
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