disabled some clang-tidy checks which are not necessary and slow down the analysis / documented disabled checks (#4468)

* added `clang-tidy.md` to document our `.clang-tidy` configuration

* disabled some clang-tidy checks which are not necessary and slow down the analysis

.clang-tidy

@@ -1,5 +1,5 @@
 ---
-Checks:          '*,-abseil-*,-altera-*,-android-*,-boost-*,-cert-*,-cppcoreguidelines-*,-darwin-*,-fuchsia-*,-google-*,-hicpp-*,-linuxkernel-*,-llvm-*,-llvmlibc-*,-mpi-*,-objc-*,-openmp-*,-zircon-*,-readability-braces-around-statements,-readability-magic-numbers,-bugprone-macro-parentheses,-readability-isolate-declaration,-readability-function-size,-modernize-use-trailing-return-type,-readability-implicit-bool-conversion,-readability-uppercase-literal-suffix,-modernize-use-auto,-readability-else-after-return,-modernize-use-default-member-init,-readability-named-parameter,-readability-redundant-member-init,-performance-faster-string-find,-modernize-avoid-c-arrays,-modernize-use-equals-default,-readability-container-size-empty,-readability-simplify-boolean-expr,-bugprone-branch-clone,-bugprone-narrowing-conversions,-modernize-raw-string-literal,-readability-convert-member-functions-to-static,-modernize-loop-convert,-readability-const-return-type,-performance-unnecessary-value-param,-modernize-return-braced-init-list,-performance-inefficient-string-concatenation,-misc-throw-by-value-catch-by-reference,-readability-avoid-const-params-in-decls,-readability-non-const-parameter,-misc-non-private-member-variables-in-classes,-bugprone-suspicious-string-compare,-clang-analyzer-*,-bugprone-signed-char-misuse,-misc-no-recursion,-readability-use-anyofallof,-performance-no-automatic-move,-bugprone-suspicious-include,-modernize-replace-random-shuffle,-readability-function-cognitive-complexity,-readability-redundant-access-specifiers,-performance-noexcept-move-constructor,-concurrency-mt-unsafe,-bugprone-easily-swappable-parameters,-readability-suspicious-call-argument,-readability-identifier-length,-readability-container-data-pointer,-bugprone-assignment-in-if-condition,-misc-const-correctness'
+Checks:          '*,-abseil-*,-altera-*,-android-*,-boost-*,-cert-*,-cppcoreguidelines-*,-darwin-*,-fuchsia-*,-google-*,-hicpp-*,-linuxkernel-*,-llvm-*,-llvmlibc-*,-mpi-*,-objc-*,-openmp-*,-zircon-*,-readability-braces-around-statements,-readability-magic-numbers,-bugprone-macro-parentheses,-readability-isolate-declaration,-readability-function-size,-modernize-use-trailing-return-type,-readability-implicit-bool-conversion,-readability-uppercase-literal-suffix,-modernize-use-auto,-readability-else-after-return,-modernize-use-default-member-init,-readability-named-parameter,-readability-redundant-member-init,-performance-faster-string-find,-modernize-avoid-c-arrays,-modernize-use-equals-default,-readability-container-size-empty,-readability-simplify-boolean-expr,-bugprone-branch-clone,-bugprone-narrowing-conversions,-modernize-raw-string-literal,-readability-convert-member-functions-to-static,-modernize-loop-convert,-readability-const-return-type,-performance-unnecessary-value-param,-modernize-return-braced-init-list,-performance-inefficient-string-concatenation,-misc-throw-by-value-catch-by-reference,-readability-avoid-const-params-in-decls,-readability-non-const-parameter,-misc-non-private-member-variables-in-classes,-bugprone-suspicious-string-compare,-clang-analyzer-*,-bugprone-signed-char-misuse,-misc-no-recursion,-readability-use-anyofallof,-performance-no-automatic-move,-bugprone-suspicious-include,-modernize-replace-random-shuffle,-readability-function-cognitive-complexity,-readability-redundant-access-specifiers,-performance-noexcept-move-constructor,-concurrency-mt-unsafe,-bugprone-easily-swappable-parameters,-readability-suspicious-call-argument,-readability-identifier-length,-readability-container-data-pointer,-bugprone-assignment-in-if-condition,-misc-const-correctness,-portability-std-allocator-const,-modernize-deprecated-ios-base-aliases,-bugprone-unchecked-optional-access,-modernize-replace-auto-ptr,-readability-identifier-naming,-portability-simd-intrinsics'
 WarningsAsErrors: '*'
 CheckOptions:
   - key:             misc-non-private-member-variables-in-classes.IgnoreClassesWithAllMemberVariablesBeingPublic

clang-tidy.md

@@ -0,0 +1,156 @@
+# clang-tidy
+
+Below are the reasoning why certain checks are (currently) disabled for out code base
+
+## Externals
+
+We do not perform static analysis of the source of the external libraries. `simplecpp` has its own CI with a clang-tidy workflow.
+
+## Disabled Checks
+
+`abseil-*`<br>
+`altera-*`<br>
+`android-*`<br>
+`boost-*`<br>
+`darwin-*`<br>
+`fuchsia-*`<br>
+`linuxkernel-*`<br>
+`llvm-*`<br>
+`llvmlibc-*`<br>
+`mpi-*`<br>
+`objc-*`<br>
+`openmp-*`<br>
+`zircon-*`<br>
+
+These are disabled since the platforms/libraries in question are not targeted by us.
+
+`cert-*`<br>
+`cppcoreguidelines-*`<br>
+`google-*`<br>
+`hicpp-*`<br>
+
+These are coding guidelines we do not follow. Some of the checks might be explicitly enabled though.
+
+`readability-braces-around-statements`<br>
+`readability-isolate-declaration`<br>
+`modernize-use-trailing-return-type`<br>
+`modernize-use-auto`<br>
+`readability-uppercase-literal-suffix`<br>
+`readability-else-after-return`<br>
+`modernize-use-default-member-init`<br>
+`readability-identifier-length`<br>
+
+These do not relect the style we are (currently) enforcing.
+
+`readability-function-size`<br>
+`readability-function-cognitive-complexity`<br>
+
+We are not interesting in the size/complexity of a function.
+
+`readability-magic-numbers`<br>
+`readability-redundant-member-init`<br>
+`readability-simplify-boolean-expr`<br>
+
+These do not (always) increase readbility.
+
+`bugprone-macro-parentheses`<br>
+`readability-implicit-bool-conversion`<br>
+`readability-named-parameter`<br>
+
+To be documented.
+
+`performance-faster-string-find`<br>
+`bugprone-narrowing-conversions`<br>
+`performance-no-automatic-move`<br>
+
+It was decided not to apply these.
+
+`modernize-use-equals-default`<br>
+`modernize-loop-convert`<br>
+
+These might change the behavior of code which might not be intended (need to file an upstream issue)
+
+`modernize-raw-string-literal`<br>
+
+This leads to a mismatch of raw string literals and regular ones and does reduce the readability.
+
+`readability-convert-member-functions-to-static`<br>
+
+Disabled because of false postives with Qt `slot` methods (see https://github.com/llvm/llvm-project/issues/57520).
+
+`-clang-analyzer-*`<br>
+
+Disable because of false positives (needs to file an upstream bug report).
+
+`misc-non-private-member-variables-in-classes`<br>
+
+We actively use this.
+
+`misc-no-recursion`<br>
+
+Leads to lots of "false positives". This seem to enforce a coding guidelines of certain codebases.
+
+`readability-use-anyofallof`<br>
+
+We currently don't even apply our own `useStlAlgorithm` findings.
+
+`bugprone-easily-swappable-parameters`<br>
+
+This produces a lot of noise and they are not fixable that easily.
+
+`readability-container-data-pointer`<br>
+
+Disable because of false positives and inconsistent warnings (need to file an upstream bug report).
+
+`misc-const-correctness`<br>
+
+Work in progress.
+
+`bugprone-assignment-in-if-condition`<br>
+
+Is reported for valid patterns we are using.
+
+`modernize-avoid-c-arrays`<br>
+`readability-container-size-empty`<br>
+`bugprone-branch-clone`<br>
+`readability-const-return-type`<br>
+`performance-unnecessary-value-param`<br>
+`modernize-return-braced-init-list`<br>
+`performance-inefficient-string-concatenation`<br>
+`misc-throw-by-value-catch-by-reference`<br>
+`readability-avoid-const-params-in-decls`<br>
+`readability-non-const-parameter`<br>
+`bugprone-suspicious-string-compare`<br>
+`bugprone-signed-char-misuse`<br>
+`bugprone-suspicious-include`<br>
+`modernize-replace-random-shuffle`<br>
+`readability-redundant-access-specifiers`<br>
+`performance-noexcept-move-constructor`<br>
+`concurrency-mt-unsafe`<br>
+`readability-suspicious-call-argument`<br>
+
+To be evaluated.
+
+`portability-std-allocator-const`<br>
+
+Only necessary for code which is exclusively compiled with `libc++`. Also disabled for performance reasons - see https://github.com/llvm/llvm-project/issues/57527#issuecomment-1237935132.
+
+`modernize-deprecated-ios-base-aliases`<br>
+
+Warns about aliases which are removed in C++20. Also disabled for performance reasons - see https://github.com/llvm/llvm-project/issues/57527#issuecomment-1237935132.
+
+`bugprone-unchecked-optional-access`<br>
+
+We are not using any `optional` implementation. Also disabled for performance reasons - see https://github.com/llvm/llvm-project/issues/57527#issuecomment-1237935132.
+
+`modernize-replace-auto-ptr`<br>
+
+Still available until C++17. It is unlikely such code will ever be introduced. Also disabled for performance reasons - see https://github.com/llvm/llvm-project/issues/57527#issuecomment-1237935132.
+
+`readability-identifier-naming`<br>
+
+We are currently using our own `naming.json` to enforce naming schemes. Also disabled for performance reasons - see https://github.com/llvm/llvm-project/issues/57527#issuecomment-1237935132.
+
+`portability-simd-intrinsics`<br>
+
+We are not using SIMD instructions and it suggests to use `std::experiemental::` features which might not be commonly available. Also disabled for performance reasons - see https://github.com/llvm/llvm-project/issues/57527#issuecomment-1237935132.