[cfe-dev] Random non-reproducible errors in ClangdTests
Mikael Holmén via cfe-dev
cfe-dev at lists.llvm.org
Wed Sep 5 22:54:43 PDT 2018
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
>
>
>
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