[cfe-dev] Running clang with valgrind.

[Andrey Tarasevich]

Hi!

I'm using clang as a parser. I'm doing at the moment one simple thing.
I'm collecting function names from the files. I run clang on set of
the files from the Linux Kernel, i.e. <linux_kernel_folder>/kernel/
Although I'm calling llvm::llvm_shutdown(); after I finished with the
file processing, I get memory leak and seems to be it is not my code,
but I'm still investigating it.

I profiled program run with Valgrind and I received following results.

==18386== 65,536 bytes in 16 blocks are possibly lost in loss record 15 of 24
==18386==    at 0x4C274A8: malloc (vg_replace_malloc.c:236)
==18386==    by 0x9F985B: llvm::MallocSlabAllocator::Allocate(unsigned
long) (in /home/sevich/src/Debug/master)
==18386==    by 0x9F95B3: llvm::BumpPtrAllocator::StartNewSlab() (in
/home/sevich/src/Debug/master)
==18386==    by 0x9F9814: llvm::BumpPtrAllocator::Allocate(unsigned
long, unsigned long) (in /home/sevich/src/Debug/master)
==18386==    by 0x8025C9: llvm::StringMap<clang::TypoCorrection,
llvm::BumpPtrAllocator>::GetOrCreateValue(llvm::StringRef) (in
/home/sevich/src/Debug/master)
==18386==    by 0x7F3CAE: (anonymous
namespace)::TypoCorrectionConsumer::addCorrection(clang::TypoCorrection)
(in /home/sevich/src/Debug/master)
==18386==    by 0x7F40A3: (anonymous
namespace)::TypoCorrectionConsumer::addName(llvm::StringRef,
clang::NamedDecl*, unsigned int, clang::NestedNameSpecifier*, bool)
(in /home/sevich/src/Debug/master)
==18386==    by 0x7F423D: (anonymous
namespace)::TypoCorrectionConsumer::FoundName(llvm::StringRef) (in
/home/sevich/src/Debug/master)
==18386==    by 0x7FF21B:
clang::Sema::CorrectTypo(clang::DeclarationNameInfo const&,
clang::Sema::LookupNameKind, clang::Scope*, clang::CXXScopeSpec*,
clang::DeclContext*, bool, clang::Sema::CorrectTypoContext,
clang::ObjCObjectPointerType const*) (in
/home/sevich/src/Debug/master)
==18386==    by 0x6E37A5:
clang::Sema::DiagnoseUnknownTypeName(clang::IdentifierInfo const&,
clang::SourceLocation, clang::Scope*, clang::CXXScopeSpec*,
clang::OpaquePtr<clang::QualType>&) (in /home/sevich/src/Debug/master)
==18386==    by 0x6288B9:
clang::Parser::ParseImplicitInt(clang::DeclSpec&,
clang::CXXScopeSpec*, clang::Parser::ParsedTemplateInfo const&,
clang::AccessSpecifier) (in /home/sevich/src/Debug/master)
==18386==    by 0x624B19:
clang::Parser::ParseDeclarationSpecifiers(clang::DeclSpec&,
clang::Parser::ParsedTemplateInfo const&, clang::AccessSpecifier,
clang::Parser::DeclSpecContext) (in /home/sevich/src/Debug/master)
==18386==
==18386== 27,126,048 (486,080 direct, 26,639,968 indirect) bytes in
6,076 blocks are definitely lost in loss record 24 of 24
==18386==    at 0x4C27CC1: operator new(unsigned long) (vg_replace_malloc.c:261)
==18386==    by 0x7F3EF2: (anonymous
namespace)::TypoCorrectionConsumer::addCorrection(clang::TypoCorrection)
(in /home/sevich/src/Debug/master)
==18386==    by 0x7F40A3: (anonymous
namespace)::TypoCorrectionConsumer::addName(llvm::StringRef,
clang::NamedDecl*, unsigned int, clang::NestedNameSpecifier*, bool)
(in /home/sevich/src/Debug/master)
==18386==    by 0x7F423D: (anonymous
namespace)::TypoCorrectionConsumer::FoundName(llvm::StringRef) (in
/home/sevich/src/Debug/master)
==18386==    by 0x7FF21B:
clang::Sema::CorrectTypo(clang::DeclarationNameInfo const&,
clang::Sema::LookupNameKind, clang::Scope*, clang::CXXScopeSpec*,
clang::DeclContext*, bool, clang::Sema::CorrectTypoContext,
clang::ObjCObjectPointerType const*) (in
/home/sevich/src/Debug/master)
==18386==    by 0x6FD184: clang::Sema::ClassifyName(clang::Scope*,
clang::CXXScopeSpec&, clang::IdentifierInfo*&, clang::SourceLocation,
clang::Token const&) (in /home/sevich/src/Debug/master)
==18386==    by 0x5FD1A7:
clang::Parser::ParseStatementOrDeclaration(clang::ASTOwningVector<clang::Stmt*,
32u>&, bool) (in /home/sevich/src/Debug/master)
==18386==    by 0x5FAAED:
clang::Parser::ParseCompoundStatementBody(bool) (in
/home/sevich/src/Debug/master)
==18386==    by 0x5FB22C:
clang::Parser::ParseCompoundStatement(clang::ParsedAttributes&, bool,
unsigned int) (in /home/sevich/src/Debug/master)
==18386==    by 0x5FB280:
clang::Parser::ParseCompoundStatement(clang::ParsedAttributes&, bool)
(in /home/sevich/src/Debug/master)
==18386==    by 0x5FD4D9:
clang::Parser::ParseStatementOrDeclaration(clang::ASTOwningVector<clang::Stmt*,
32u>&, bool) (in /home/sevich/src/Debug/master)
==18386==    by 0x60029E:
clang::Parser::ParseWhileStatement(clang::ParsedAttributes&) (in
/home/sevich/src/Debug/master)

Is this really a memory leak or I'm missing something?

Cheers,
Andrey Tarasevich