ClazyClangTidy plugin not working

[SquallATF]

Description / Steps to reproduce the issue

When running the following command, no checks are listed:

clang-tidy -checks=-*,clazy-* -list-checks -load ClazyClangTidy.dll

The issue seems related to how the plugin links against libclangTidy. The mingw-w64-clazy/001-fix-linking.patch patch links the ClazyClangTidy plugin with the static clangTidy library, but clang-tidy plugins actually require certain symbols to be exported from clang-tidy.exe itself.

Expected behavior

When running the following command, should print clazy serials checks:

clang-tidy -checks=-*,clazy-* -list-checks -load ClazyClangTidy.dll

Enabled checks:
    clazy-assert-with-side-effects
    clazy-auto-unexpected-qstringbuilder
    clazy-base-class-event
    clazy-child-event-qobject-cast
    clazy-connect-3arg-lambda
    clazy-connect-by-name
    clazy-connect-non-signal
    clazy-connect-not-normalized
    clazy-const-signal-or-slot
    clazy-container-anti-pattern
    clazy-container-inside-loop
    clazy-copyable-polymorphic
    clazy-ctor-missing-parent-argument
    clazy-detaching-member
    clazy-detaching-temporary
    clazy-empty-qstringliteral
    clazy-foreach
    clazy-fully-qualified-moc-types
    clazy-function-args-by-ref
    clazy-function-args-by-value
    clazy-global-const-char-pointer
    clazy-heap-allocated-small-trivial-type
    clazy-ifndef-define-typo
    clazy-implicit-casts
    clazy-incorrect-emit
    clazy-install-event-filter
    clazy-isempty-vs-count
    clazy-jni-signatures
    clazy-lambda-in-connect
    clazy-lambda-unique-connection
    clazy-lowercase-qml-type-name
    clazy-missing-qobject-macro
    clazy-missing-typeinfo
    clazy-mutable-container-key
    clazy-no-module-include
    clazy-non-pod-global-static
    clazy-old-style-connect
    clazy-overloaded-signal
    clazy-overridden-signal
    clazy-post-event
    clazy-qbytearray-conversion-to-c-style
    clazy-qcolor-from-literal
    clazy-qdatetime-utc
    clazy-qdeleteall
    clazy-qenums
    clazy-qfileinfo-exists
    clazy-qgetenv
    clazy-qhash-namespace
    clazy-qhash-with-char-pointer-key
    clazy-qlatin1string-non-ascii
    clazy-qmap-with-pointer-key
    clazy-qproperty-type-mismatch
    clazy-qproperty-without-notify
    clazy-qrequiredresult-candidates
    clazy-qstring-allocations
    clazy-qstring-arg
    clazy-qstring-comparison-to-implicit-char
    clazy-qstring-insensitive-allocation
    clazy-qstring-left
    clazy-qstring-ref
    clazy-qstring-varargs
    clazy-qt-keyword-emit
    clazy-qt-keywords
    clazy-qt-macros
    clazy-qvariant-template-instantiation
    clazy-range-loop-detach
    clazy-range-loop-reference
    clazy-raw-environment-function
    clazy-readlock-detaching
    clazy-reserve-candidates
    clazy-returning-data-from-temporary
    clazy-returning-void-expression
    clazy-rule-of-three
    clazy-rule-of-two-soft
    clazy-sanitize-inline-keyword
    clazy-signal-with-return-value
    clazy-skipped-base-method
    clazy-static-pmf
    clazy-strict-iterators
    clazy-temporary-iterator
    clazy-thread-with-slots
    clazy-tr-non-literal
    clazy-unexpected-flag-enumerator-value
    clazy-unneeded-cast
    clazy-unused-non-trivial-variable
    clazy-unused-result-check
    clazy-use-arrow-operator-instead-of-data
    clazy-use-chrono-in-qtimer
    clazy-use-static-qregularexpression
    clazy-used-qunused-variable
    clazy-virtual-call-ctor
    clazy-virtual-signal
    clazy-writing-to-temporary
    clazy-wrong-qevent-cast
    clazy-wrong-qglobalstatic

Actual behavior

When running the following command, no checks are listed:

clang-tidy -checks=-*,clazy-* -list-checks -load ClazyClangTidy.dll

Verification

• [x] I have verified that my MSYS2 is up-to-date before submitting the report (see https://www.msys2.org/docs/updating/)

Windows Version

MINGW64_NT-10.0-26200

MINGW environments affected

• [ ] MINGW64
• [ ] MINGW32
• [ ] UCRT64
• [x] CLANG64
• [ ] CLANGARM64

Are you willing to submit a PR?

No response

[Alexpux]

@SquallATF without this patch it not linking at all. You can try provide better solution

[SquallATF]

Normally, when building Clazy on Windows, LLVM must be compiled with the CMake option -DLLVM_EXPORT_SYMBOLS_FOR_PLUGINS=ON so that the necessary plugin symbols are exported from the executable.

But LLVM_LINK_LLVM_DYLIB and LLVM_EXPORT_SYMBOLS_FOR_PLUGINS are incompatible, it’s not possible to both link against the shared LLVM library and also export plugin symbols from the executable at the same time.

One possible workaround is to:

1. Build clangTidy library as a shared library might be the best solution. I haven’t tested it yet, but exporting symbols from an executable feels a bit odd, or
2. Follow the logic in AddLLVM.cmake#L1388-L1399 and AddLLVM.cmake#L140-L166 to generate a .def file from libclangTidy.a and make clang-tidy.exe export the corresponding symbols. However, the generated .def file has some issues:
   it doesn’t correctly mark which exported symbols are DATA, which causes runtime errors.
   To make the ClazyClangTidy.dll plugin work properly, the following symbols must be manually marked as DATA:

...
_ZN4llvm8RegistryIN5clang4tidy15ClangTidyModuleEE4HeadE DATA
_ZN4llvm8RegistryIN5clang4tidy15ClangTidyModuleEE4TailE DATA
...
_ZN5clang4tidy24ClangTidyOptionsProvider30OptionsSourceTypeDefaultBinaryE DATA
_ZN5clang4tidy24ClangTidyOptionsProvider39OptionsSourceTypeCheckCommandLineOptionE DATA
_ZN5clang4tidy24ClangTidyOptionsProvider40OptionsSourceTypeConfigCommandLineOptionE DATA
...

Otherwise, the plugin will fail to load at runtime. or 3. can simply disable this plugin for now, as the currently compiled version doesn’t work correctly anyway.