.clang-tidy

# clang-tidy is a C/C++ static analyzer that is helpful in detecting potential errors or malpractices in C/C++ codebases.
# clang-tidy bundles its own checks and also capable of using Clang Static Analyzer checks.
# Each check offered by clang-tidy or Clang Static Analyzer has a name and can be chosen for use using the `-checks=` option.
# -checks= option specifies a list of comma separated globs.
# these globs are either prefixed with a negative sign or not
# prefixing globs with negative sign removes them from clang-tidy's consideration while no prefix adds them to the checks performed by clang-tidy.
# -checks also accepts wildcard specifiers which help to chose subsets of like named checks or to enable or disable checks alltogether.

# e.g. -checks=-* will disable all the checks available in clang-tidy
# while -checks=* will enable all available checks.
# REMEBER WHAT MATTERS HERE IS THE PREFIX, HYPHENS THAT OCCUR IN THE MIDDLE OF CHECK TOKENS ARE USED WITH WILDCARD SPECIFIERS FOR PATTERN MATCHING.

# e.g. -checks=-*,clang-analyzer-*,-clang-analyzer-cplusplus*
# this will first disable all available (checks that were enabled by default) checks. then will enable all checks under the category
# clang-analyzer-* (note the use of wildcard here) except for checks that were under the subcategory clang-analyzer-cplusplus* (again note the ocurrence of the wildcard here)

# some clang-tidy checks are draconian and overly pedantic. there are few ways to suppress such warnings/errors.
# check specific workarounds are available to disable select instances of certain diagnostics!
# bugprone-use-after-move can be silenced by re-initializing the variable after it has been moved out
# bugprone-string-integer-assignment can be suppressed by explicitly casting the integer to char
# readability-implicit-bool-conversion can also be suppressed by using explicit casts, etc.

# clang-tidy also offers some generic mechanisms to override the diagnostic configs
# an inline trailing // NOLINT disables all diagnostics for the line.
# the reason for choosing to suppress the warning can be registered like so
# // NOLINT: <did that because of this>

# // NOLINT offers customization options with the option to use wildcards for categorical exclusion.
# // NOLINT(google-explicit-constructor, google-runtime-int)
# will disable only the chosen two checks for the line

# // NOLINT(google*) will disable all checks from the module google.

# // NOLINT(*-avoid-c-arrays) will disable all diagnostics (possibly from different modules) with a label that ends with `-avoid-c-arrays`
# this is a cross module linter flag for that line.

# // NOLINTNEXTLINE can be used in the same way as // NOLINT but its effects only apply to the following line.
# specify // NOLINTNEXTLIN in a dedicated line i.e not as a trailing comment on an existing line

# clang-tidy also has an option to ignore diagnostics for code regions, using the BEGIN and END postfixes
# // NOLINTBEGIN starts a section where clang-tidy diagnostics are skipped
# // NOLINTEND closes the preceding section.
# // NOLINTBEGIN also accepts optional parameters inside a parenthesis, like // NOLINTBEGIN(google-*)

# note that whitespaces between NOLINT/NOLINTNEXTLINE/NOLINTBEGIN/NOLINTEND and the opening parenthesis are not allowed
# (in this case the comment will be treated just as NOLINT/NOLINTNEXTLINE/NOLINTBEGIN/NOLINTEND), whereas in the check names list
# (inside the parentheses), whitespaces can be used and will be ignored.

# all NOLINTBEGIN comments must be paired by an equal number of NOLINTEND comments. Moreover, a pair of comments must have matching arguments
# for example, NOLINTBEGIN(check-name) can be paired with NOLINTEND(check-name) but not with NOLINTEND (zero arguments).
# clang-tidy will generate a clang-tidy-nolint error diagnostic if any NOLINTBEGIN/NOLINTEND comment violates these requirements.

########################################################
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#                TAILOR MADE FOR C++                   #
########################################################
# AVOID TRAILING INLINE COMMENTS IN .clang-tidy FILES! #
########################################################
########################################################

# JSON is a subset of YAML, so we could practically use JSON syntax in .clang-format, .clang-tidy and .clangd files!

# Here is a list of slow checks that were initially enabled, now removed to improve lint time.
# REMEMBER THESE ARE C++ PROBLEMS, DOESN'T APPLY TO LINTING C SOURCES.

# misc-const-correctness, readability-uppercase-literal-suffix, bugprone-standalone-empty, modernize-use-std-numbers, bugprone-unused-return-value,
# bugprone-assert-side-effect, cppcoreguidelines-pro-bounds-array-to-pointer-decay, modernize-use-nullptr, misc-unused-using-decls,
# bugprone-stringview-nullptr, bugprone-infinite-loop, readability-non-const-parameter, readability-container-size-empty, bugprone-suspicious-string-compare,
# misc-redundant-expression, modernize-type-traits, misc-confusable-identifiers, bugprone-implicit-widening-of-multiplication-result, readability-redundant-control-flow,
# readability-identifier-length, bugprone-multiple-statement-macro, bugprone-suspicious-semicolon, bugprone-sizeof-expression, bugprone-inc-dec-in-conditions,
# readability-redundant-casting, modernize-use-bool-literals,

Checks: >
  -*,
  bugprone-assignment-in-if-condition,
  bugprone-bool-pointer-implicit-conversion,
  bugprone-branch-clone,
  bugprone-casting-through-void,
  bugprone-chained-comparison,
  bugprone-compare-pointer-to-member-virtual-function,
  bugprone-copy-constructor-init,
  bugprone-crtp-constructor-accessibility,
  bugprone-dangling-handle,
  bugprone-dynamic-static-initializers,
  bugprone-empty-catch,
  bugprone-exception-escape,
  bugprone-fold-init-type,
  bugprone-forward-declaration-namespace,
  bugprone-forwarding-reference-overload,
  bugprone-inaccurate-erase,
  bugprone-incorrect-enable-if,
  bugprone-incorrect-roundings,
  bugprone-integer-division,
  bugprone-lambda-function-name,
  bugprone-macro-parentheses,
  bugprone-macro-repeated-side-effects,
  bugprone-misplaced-operator-in-strlen-in-alloc,
  bugprone-misplaced-pointer-arithmetic-in-alloc,
  bugprone-misplaced-widening-cast,
  bugprone-move-forwarding-reference,
  bugprone-multi-level-implicit-pointer-conversion,
  bugprone-multiple-new-in-one-expression,
  bugprone-non-zero-enum-to-bool-conversion,
  bugprone-not-null-terminated-result,
  bugprone-redundant-branch-condition,
  bugprone-shared-ptr-array-mismatch,
  bugprone-signal-handler,
  bugprone-signed-char-misuse,
  bugprone-sizeof-container,
  bugprone-spuriously-wake-up-functions,
  bugprone-string-constructor,
  bugprone-string-integer-assignment,
  bugprone-string-literal-with-embedded-nul,
  bugprone-suspicious-enum-usage,
  bugprone-suspicious-include,
  bugprone-suspicious-memory-comparison,
  bugprone-suspicious-memset-usage,
  bugprone-suspicious-missing-comma,
  bugprone-suspicious-realloc-usage,
  bugprone-suspicious-stringview-data-usage,
  bugprone-swapped-arguments,
  bugprone-switch-missing-default-case,
  bugprone-terminating-continue,
  bugprone-throw-keyword-missing,
  bugprone-too-small-loop-variable,
  bugprone-unchecked-optional-access,
  bugprone-undefined-memory-manipulation,
  bugprone-undelegated-constructor,
  bugprone-unhandled-exception-at-new,
  bugprone-unhandled-self-assignment,
  bugprone-unique-ptr-array-mismatch,
  bugprone-unsafe-functions,
  bugprone-unused-local-non-trivial-variable,
  bugprone-unused-raii,
  bugprone-use-after-move,
  bugprone-virtual-near-miss,
  cert-dcl50-cpp,
  cert-dcl58-cpp,
  cert-env33-c,
  cert-err34-c,
  cert-flp30-c,
  cert-err52-cpp,
  cert-err58-cpp,
  cert-err60-cpp,
  cert-mem57-cpp,
  cert-oop57-cpp,
  cert-oop58-cpp,
  cppcoreguidelines-avoid-capturing-lambda-coroutines,
  cppcoreguidelines-avoid-const-or-ref-data-members,
  cppcoreguidelines-avoid-non-const-global-variables,
  cppcoreguidelines-avoid-reference-coroutine-parameters,
  cppcoreguidelines-init-variables,
  cppcoreguidelines-interfaces-global-init,
  cppcoreguidelines-macro-usage,
  cppcoreguidelines-misleading-capture-default-by-value,
  cppcoreguidelines-missing-std-forward,
  cppcoreguidelines-narrowing-conversions,
  cppcoreguidelines-no-suspend-with-lock,
  cppcoreguidelines-prefer-member-initializer,
  cppcoreguidelines-pro-bounds-constant-array-index,
  cppcoreguidelines-pro-bounds-pointer-arithmetic,
  cppcoreguidelines-pro-type-const-cast,
  cppcoreguidelines-pro-type-cstyle-cast,
  cppcoreguidelines-pro-type-member-init,
  cppcoreguidelines-pro-type-static-cast-downcast,
  cppcoreguidelines-pro-type-union-access,
  cppcoreguidelines-pro-type-vararg,
  cppcoreguidelines-rvalue-reference-param-not-moved,
  cppcoreguidelines-slicing,
  cppcoreguidelines-special-member-functions,
  cppcoreguidelines-virtual-class-destructor,
  google-build-namespaces,
  google-build-using-namespace,
  google-explicit-constructor,
  google-runtime-operator,
  misc-coroutine-hostile-raii,
  misc-definitions-in-headers,
  misc-header-include-cycle,
  misc-misplaced-const,
  misc-new-delete-overloads,
  misc-no-recursion,
  misc-non-private-member-variables-in-classes,
  misc-static-assert,
  misc-throw-by-value-catch-by-reference,
  misc-unconventional-assign-operator,
  misc-unused-alias-decls,
  misc-unused-parameters,
  modernize-avoid-c-arrays,
  modernize-concat-nested-namespaces,
  modernize-deprecated-headers,
  modernize-deprecated-ios-base-aliases,
  modernize-raw-string-literal,
  modernize-redundant-void-arg,
  modernize-replace-random-shuffle,
  modernize-return-braced-init-list,
  modernize-use-constraints,
  modernize-use-designated-initializers,
  modernize-use-emplace,
  modernize-use-equals-default,
  modernize-use-equals-delete,
  modernize-use-override,
  modernize-use-uncaught-exceptions,
  modernize-use-using,
  performance-avoid-endl,
  performance-enum-size,
  performance-faster-string-find,
  performance-for-range-copy,
  performance-implicit-conversion-in-loop,
  performance-inefficient-algorithm,
  performance-inefficient-string-concatenation,
  performance-inefficient-vector-operation,
  performance-move-const-arg,
  performance-no-int-to-ptr,
  performance-noexcept-destructor,
  performance-noexcept-move-constructor,
  performance-trivially-destructible,
  performance-type-promotion-in-math-fn,
  performance-unnecessary-copy-initialization,
  performance-unnecessary-value-param,
  readability-avoid-const-params-in-decls,
  readability-avoid-nested-conditional-operator,
  readability-avoid-return-with-void-value,
  readability-avoid-unconditional-preprocessor-if,
  readability-const-return-type,
  readability-convert-member-functions-to-static,
  readability-delete-null-pointer,
  readability-duplicate-include,
  readability-else-after-return,
  readability-enum-initial-value,
  readability-inconsistent-declaration-parameter-name,
  readability-isolate-declaration,
  readability-make-member-function-const,
  readability-misleading-indentation,
  readability-misplaced-array-index,
  readability-qualified-auto,
  readability-redundant-access-specifiers,
  readability-redundant-declaration,
  readability-redundant-function-ptr-dereference,
  readability-redundant-inline-specifier,
  readability-redundant-member-init,
  readability-redundant-preprocessor,
  readability-redundant-smartptr-get,
  readability-redundant-string-cstr,
  readability-redundant-string-init,
  readability-reference-to-constructed-temporary,
  readability-simplify-boolean-expr,
  readability-simplify-subscript-expr,
  readability-static-accessed-through-instance,
  readability-static-definition-in-anonymous-namespace,
  readability-string-compare,
  readability-uniqueptr-delete-release,
  readability-use-anyofallof,
  readability-use-std-min-max,
  clang-analyzer-core.BitwiseShift,
  clang-analyzer-core.CallAndMessage,
  clang-analyzer-core.DivideZero,
  clang-analyzer-core.NonNullParamChecker,
  clang-analyzer-core.NullDereference,
  clang-analyzer-core.StackAddressEscape,
  clang-analyzer-core.UndefinedBinaryOperatorResult,
  clang-analyzer-core.VLASize,
  clang-analyzer-core.uninitialized.ArraySubscript,
  clang-analyzer-core.uninitialized.Assign,
  clang-analyzer-core.uninitialized.Branch,
  clang-analyzer-core.uninitialized.CapturedBlockVariable,
  clang-analyzer-core.uninitialized.UndefReturn,
  clang-analyzer-core.uninitialized.NewArraySize,
  clang-analyzer-cplusplus.ArrayDelete,
  clang-analyzer-cplusplus.InnerPointer,
  clang-analyzer-cplusplus.NewDelete,
  clang-analyzer-cplusplus.NewDeleteLeaks,
  clang-analyzer-cplusplus.PlacementNew,
  clang-analyzer-cplusplus.SelfAssignment,
  clang-analyzer-cplusplus.StringChecker,
  clang-analyzer.deadcode.DeadStores,
  clang-analyzer.optin.core.EnumCastOutOfRange,
  clang-analyzer.optin.cplusplus.UninitializedObject,
  clang-analyzer.optin.cplusplus.VirtualCall,
  clang-analyzer.optin.performance.Padding,
  clang-analyzer.security.cert.env.InvalidPtr,
  clang-analyzer.security.FloatLoopCounter,
  clang-analyzer.security.insecureAPI.UncheckedReturn,
  clang-analyzer.security.insecureAPI.bcmp,
  clang-analyzer.security.insecureAPI.bcopy,
  clang-analyzer.security.insecureAPI.bzero,
  clang-analyzer.security.insecureAPI.getpw,
  clang-analyzer.security.insecureAPI.gets,
  clang-analyzer.security.insecureAPI.mkstemp,
  clang-analyzer.security.insecureAPI.mktemp,
  clang-analyzer.security.insecureAPI.rand,
  clang-analyzer.security.insecureAPI.strcpy,
  clang-analyzer.security.insecureAPI.DeprecatedOrUnsafeBufferHandling,
  clang-analyzer-unix.API,
  clang-analyzer-unix.Errno,
  clang-analyzer-unix.Malloc,
  clang-analyzer-unix.MallocSizeof,
  clang-analyzer-unix.MismatchedDeallocator,
  clang-analyzer-unix.StdCLibraryFunctions,
  clang-analyzer-unix.cstring.BadSizeArg,
  clang-analyzer-unix.cstring.NullArg,
  clang-analyzer-valist.CopyToSelf,
  clang-analyzer-valist.Uninitialized,
  clang-analyzer-valist.Unterminated,
  clang-analyzer-webkit.NoUncountedMemberChecker

# -* disables all default checks. doing this as I want to handpick the checks I want without any interference from clang-tidy's defaults.

ExtraArgs: ['-Wall', '-Wextra', '--std=c++20', '-c', '-O0', '--pedantic', '-DDEBUG', '-D_DEBUG', '-I./']
# extra arguments to pass to the compiler, these have decisive impact on the diagnostics issued as clang-tidy uses the AST generated by the
# clang frontend for static analyses, not the raw source file. and these flags can significantly alter the structure of the AST

FormatStyle: file
# format the source file using the specs in the .clang-format file.

HeaderFileExtensions:         ['hpp', 'cuh', '']

HeaderFilterRegex:   ''
# ignore diagnostics from c++ STL headers.

ImplementationFileExtensions: ['cpp', 'cu']

WarningsAsErrors: '-*'
# treat all clang-tidy warnings as errors, similar to -Werr or /WX, but for linting

User: anoban
# Specifies the name or e-mail of the user running clang-tidy. This option is used, for example, to place the correct user name
# in TODO() comments in the relevant check.

UseColor: true

# for the configs in bugprone-argument-comment, clang-tidy uses an arbitraty heuristic to determine how close the comment is to the
# parameter name. it'll issue a diagnostic if the comment in `ago` where the parameter name was `age` but won't when the comment is `address`

# list of required checks
CheckOptions:

  - key: bugprone-implicit-widening-of-multiplication-result.UseCXXStaticCastsInCppSources
    value: false
  - key: bugprone-implicit-widening-of-multiplication-result.UseCXXHeadersInCppSources
    value: true

  - key: bugprone-not-null-terminated-result.WantToUseSafeFunctions
    value: true

  - key: bugprone-signal-handler.AsyncSafeFunctionSet
    value: POSIX

  - key: bugprone-sizeof-expression.WarnOnSizeOfConstant
    value: true
  - key: bugprone-sizeof-expression.WarnOnSizeOfIntegerExpression
    value: true
  - key: bugprone-sizeof-expression.WarnOnSizeOfCompareToConstant
    value: true
  - key: bugprone-sizeof-expression.WarnOnSizeOfPointerToAggregate
    value: true

  - key: bugprone-suspicious-enum-usage.StrictMode
    value: 1

  - key: bugprone-too-small-loop-variable.MagnitudeBitsUpperLimit
    value: 30

  - key: misc-unused-parameters.StrictMode
    value: true

  - key: readability-enum-initial-value.AllowExplicitZeroFirstInitialValue
    value: true
  - key: readability-enum-initial-value.AllowExplicitSequentialInitialValues
    value: true

  - key: readability-inconsistent-declaration-parameter-name.IgnoreMacros
    value: false
  - key: readability-inconsistent-declaration-parameter-name.Strict
    value: true

  - key: readability-redundant-inline-specifier.StrictMode
    value: true

  - key: readability-uppercase-literal-suffix.NewSuffixes
    value: 'L;LU;LLU;I8;U8,I16,U16,I32,U32,I64,U64'

  - key: clang-analyzer-core.BitwiseShift.Pedantic
    value: true

  - key: clang-analyzer.security.cert.env.InvalidPtr.InvalidatingGetEnv
    value: true

  - key: cppcoreguidelines-narrowing-conversions.WarnOnIntegerNarrowingConversion
    value: true
  - key: cppcoreguidelines-narrowing-conversions.WarnOnIntegerToFloatingPointNarrowingConversion
    value: true
  - key: cppcoreguidelines-narrowing-conversions.WarnOnFloatingPointNarrowingConversion
    value: true
  - key: cppcoreguidelines-narrowing-conversions.WarnWithinTemplateInstantiation
    value: true
  - key: cppcoreguidelines-narrowing-conversions.WarnOnEquivalentBitWidth
    value: true
  - key: cppcoreguidelines-narrowing-conversions.PedanticMode
    value: true

  - key: cppcoreguidelines-pro-type-const-cast.StrictMode
    value: true

  - key: cppcoreguidelines-pro-type-member-init.IgnoreArrays
    value: true

  - key: misc-non-private-member-variables-in-classes.IgnoreClassesWithAllMemberVariablesBeingPublic
    value: true
  - key: misc-non-private-member-variables-in-classes.IgnorePublicMemberVariables
    value: true

  - key: misc-throw-by-value-catch-by-reference.CheckThrowTemporaries
    value: true
  - key: misc-throw-by-value-catch-by-reference.WarnOnLargeObject
    value: true
  - key: misc-throw-by-value-catch-by-reference.MaxSize
    value: 8