[PATCH] D139774: [libclang] Add API to set temporary directory location

Tue Jan 10 08:31:05 PST 2023

vedgy added a comment.

In D139774#4039975 <https://reviews.llvm.org/D139774#4039975>, @aaron.ballman wrote:

> Oh that is a good point! Apologies for not noticing that earlier -- that makes me wonder if a better approach here is to add a `std::string` to the `CIndexer` class to represent the temp path to use.

I have suggested the possibility in this review:

> A copy of user-provided temporary directory path buffer can be stored in class `CIndexer`. But this API in //llvm/Support/Path.h// would stay fragile.

So the question is whether the LLVM API or `CIndexer` should store the buffer.

The only possible caller of `system_temp_directory()` used by libclang is `llvm::sys::fs::createUniquePath()`. This helper function is called by `createUniqueEntity()`, which in turn is called by several other helper functions, all in //llvm/lib/Support/Path.cpp//. Here is a backtrace from KDevelop built against LLVM at this review's branch:

  #0 llvm::sys::path::system_temp_directory(bool, llvm::SmallVectorImpl<char>&) (ErasedOnReboot=true, Result=...) at /home/Mint14_home/igor/Documents/C/LinuxProjects/external/llvm-project/llvm/lib/Support/Unix/Path.inc:1451
  #1 0x00007fb372a55d60 in llvm::sys::fs::createUniquePath(llvm::Twine const&, llvm::SmallVectorImpl<char>&, bool) (Model=<optimized out>, ResultPath=..., MakeAbsolute=<optimized out>) at /home/Mint14_home/igor/Documents/C/LinuxProjects/external/llvm-project/llvm/lib/Support/Path.cpp:811
  #2 0x00007fb372a55eb7 in createUniqueEntity(llvm::Twine const&, int&, llvm::SmallVectorImpl<char>&, bool, FSEntity, llvm::sys::fs::OpenFlags, unsigned int) (Model=..., ResultFD=@0x7fb36effc2d0: 0, ResultPath=..., MakeAbsolute=<optimized out>, Type=FS_File, Flags=llvm::sys::fs::OF_None, Mode=384) at /home/Mint14_home/igor/Documents/C/LinuxProjects/external/llvm-project/llvm/lib/Support/Path.cpp:181
  #3 0x00007fb372a5623b in llvm::sys::fs::createTemporaryFile (Flags=llvm::sys::fs::OF_None, Type=FS_File, ResultPath=..., ResultFD=@0x7fb36effc2d0: 0, Model=...) at /home/Mint14_home/igor/Documents/C/LinuxProjects/external/llvm-project/llvm/include/llvm/ADT/Twine.h:233
  #4 llvm::sys::fs::createTemporaryFile(llvm::Twine const&, llvm::StringRef, int&, llvm::SmallVectorImpl<char>&, FSEntity, llvm::sys::fs::OpenFlags) (Prefix=<optimized out>, Suffix=..., ResultFD=@0x7fb36effc2d0: 0, ResultPath=..., Type=Type at entry=FS_File, Flags=llvm::sys::fs::OF_None) at /home/Mint14_home/igor/Documents/C/LinuxProjects/external/llvm-project/llvm/lib/Support/Path.cpp:865
  #5 0x00007fb372a56451 in llvm::sys::fs::createTemporaryFile(llvm::Twine const&, llvm::StringRef, int&, llvm::SmallVectorImpl<char>&, llvm::sys::fs::OpenFlags) (Prefix=<optimized out>, Suffix=..., ResultFD=<optimized out>, ResultPath=<optimized out>, Flags=<optimized out>) at /home/Mint14_home/igor/Documents/C/LinuxProjects/external/llvm-project/llvm/lib/Support/Path.cpp:873
  #6 0x00007fb3717cc1b7 in (anonymous namespace)::TempPCHFile::create () at /home/Mint14_home/igor/Documents/C/LinuxProjects/external/llvm-project/llvm/include/llvm/ADT/Twine.h:233
  #7 clang::PrecompiledPreamble::Build(clang::CompilerInvocation const&, llvm::MemoryBuffer const*, clang::PreambleBounds, clang::DiagnosticsEngine&, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>, std::shared_ptr<clang::PCHContainerOperations>, bool, clang::PreambleCallbacks&) (Invocation=..., MainFileBuffer=0x7fb35000a360, Bounds=Bounds at entry=..., Diagnostics=..., VFS=..., PCHContainerOps=std::shared_ptr<clang::PCHContainerOperations> (use count 5, weak count 0) = {...}, StoreInMemory=false, Callbacks=...) at /home/igor/Documents/C/LinuxProjects/external/llvm-project/clang/lib/Frontend/PrecompiledPreamble.cpp:421
  #8 0x00007fb3717234a8 in clang::ASTUnit::getMainBufferWithPrecompiledPreamble(std::shared_ptr<clang::PCHContainerOperations>, clang::CompilerInvocation&, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>, bool, unsigned int) (this=0x7fb3505c44d0, PCHContainerOps=std::shared_ptr<clang::PCHContainerOperations> (use count 5, weak count 0) = {...}, PreambleInvocationIn=..., VFS=..., AllowRebuild=<optimized out>, MaxLines=0) at /usr/include/c++/12.2.0/bits/unique_ptr.h:191
  #9 0x00007fb371729bd6 in clang::ASTUnit::LoadFromCompilerInvocation(std::shared_ptr<clang::PCHContainerOperations>, unsigned int, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>) (this=0x7fb3505c44d0, PCHContainerOps=std::shared_ptr<clang::PCHContainerOperations> (use count 5, weak count 0) = {...}, PrecompilePreambleAfterNParses=<optimized out>, VFS=...) at /home/igor/Documents/C/LinuxProjects/external/llvm-project/clang/lib/Frontend/ASTUnit.cpp:1685
  #10 0x00007fb37172e359 in clang::ASTUnit::LoadFromCommandLine(char const**, char const**, std::shared_ptr<clang::PCHContainerOperations>, llvm::IntrusiveRefCntPtr<clang::DiagnosticsEngine>, llvm::StringRef, bool, clang::CaptureDiagsKind, llvm::ArrayRef<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, llvm::MemoryBuffer*> >, bool, unsigned int, clang::TranslationUnitKind, bool, bool, bool, clang::SkipFunctionBodiesScope, bool, bool, bool, bool, llvm::Optional<llvm::StringRef>, std::unique_ptr<clang::ASTUnit, std::default_delete<clang::ASTUnit> >*, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>) (ArgBegin=<optimized out>, ArgEnd=<optimized out>, PCHContainerOps=std::shared_ptr<clang::PCHContainerOperations> (empty) = {...}, Diags=..., ResourceFilesPath=..., OnlyLocalDecls=false, CaptureDiagnostics=clang::CaptureDiagsKind::All, RemappedFiles=..., RemappedFilesKeepOriginalName=true, PrecompilePreambleAfterNParses=1, TUKind=clang::TU_Complete, CacheCodeCompletionResults=true, IncludeBriefCommentsInCodeCompletion=false, AllowPCHWithCompilerErrors=true, SkipFunctionBodies=clang::SkipFunctionBodiesScope::None, SingleFileParse=false, UserFilesAreVolatile=true, ForSerialization=false, RetainExcludedConditionalBlocks=false, ModuleFormat=..., ErrAST=0x7fb36effd2d8, VFS=...) at /home/igor/Documents/C/LinuxProjects/external/llvm-project/clang/lib/Frontend/ASTUnit.cpp:1822
  #11 0x00007fb37104e462 in clang_parseTranslationUnit_Impl(CXIndex, char const*, char const* const*, int, llvm::ArrayRef<CXUnsavedFile>, unsigned int, CXTranslationUnit*) (CIdx=0x55dbe16c9360, source_filename=<optimized out>, command_line_args=<optimized out>, num_command_line_args=<optimized out>, unsaved_files=..., options=781, out_TU=0x7fb35ca7f630) at /usr/include/c++/12.2.0/bits/stl_vector.h:987
  #12 0x00007fb37104f2b4 in operator() (__closure=0x7fb37a7b6f40) at /home/igor/Documents/C/LinuxProjects/external/llvm-project/clang/tools/libclang/CIndex.cpp:3976
  #13 llvm::function_ref<void()>::callback_fn<clang_parseTranslationUnit2FullArgv(CXIndex, char const*, char const* const*, int, CXUnsavedFile*, unsigned int, unsigned int, CXTranslationUnitImpl**)::<lambda()> >(intptr_t) (callable=callable at entry=140408830783296) at /home/Mint14_home/igor/Documents/C/LinuxProjects/external/llvm-project/llvm/include/llvm/ADT/STLFunctionalExtras.h:45
  #14 0x00007fb3729cc6e0 in llvm::function_ref<void ()>::operator()() const (this=<synthetic pointer>) at /home/Mint14_home/igor/Documents/C/LinuxProjects/external/llvm-project/llvm/include/llvm/ADT/STLFunctionalExtras.h:68
  #15 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (this=<optimized out>, Fn=...) at /home/Mint14_home/igor/Documents/C/LinuxProjects/external/llvm-project/llvm/lib/Support/CrashRecoveryContext.cpp:433
  #16 0x00007fb3729cc724 in RunSafelyOnThread_Dispatch(void*) (UserData=0x7fb37a7b6e80) at /home/Mint14_home/igor/Documents/C/LinuxProjects/external/llvm-project/llvm/lib/Support/CrashRecoveryContext.cpp:514
  #17 0x00007fb3729cc19a in llvm::thread::Apply<void (*)(void*), (anonymous namespace)::RunSafelyOnThreadInfo*, 0> (Callee=std::tuple containing = {...}) at /home/Mint14_home/igor/Documents/C/LinuxProjects/external/llvm-project/llvm/include/llvm/Support/thread.h:42
  #18 llvm::thread::GenericThreadProxy<std::tuple<void (*)(void*), (anonymous namespace)::RunSafelyOnThreadInfo*> > (Ptr=0x55dbe3921080) at /home/Mint14_home/igor/Documents/C/LinuxProjects/external/llvm-project/llvm/include/llvm/Support/thread.h:50
  #19 llvm::thread::ThreadProxy<std::tuple<void (*)(void*), (anonymous namespace)::RunSafelyOnThreadInfo*> >(void*) (Ptr=0x55dbe3921080) at /home/Mint14_home/igor/Documents/C/LinuxProjects/external/llvm-project/llvm/include/llvm/Support/thread.h:60
  #20 0x00007fb3e909f8fd in () at /usr/lib/libc.so.6
  #21 0x00007fb3e9121a60 in () at /usr/lib/libc.so.6

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