.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.

########################################################
########################################################
#                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!

Checks: >
  -*,
  bugprone-assert-side-effect,
  bugprone-assignment-in-if-condition,
  bugprone-bool-pointer-implicit-conversion,
  bugprone-branch-clone,
  bugprone-casting-through-void,
  bugprone-chained-comparison,
  bugprone-dynamic-static-initializers,
  bugprone-implicit-widening-of-multiplication-result,
  bugprone-inc-dec-in-conditions,
  bugprone-incorrect-roundings,
  bugprone-infinite-loop,
  bugprone-integer-division,
  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-multi-level-implicit-pointer-conversion,
  bugprone-multiple-statement-macro,
  bugprone-non-zero-enum-to-bool-conversion,
  bugprone-not-null-terminated-result,
  bugprone-redundant-branch-condition,
  bugprone-signal-handler,
  bugprone-signed-char-misuse,
  bugprone-sizeof-expression,
  bugprone-spuriously-wake-up-functions,
  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-semicolon,
  bugprone-suspicious-string-compare,
  bugprone-swapped-arguments,
  bugprone-switch-missing-default-case,
  bugprone-terminating-continue,
  bugprone-too-small-loop-variable,
  bugprone-unsafe-functions,
  bugprone-unused-return-value,
  cert-dcl50-cpp,
  cert-env33-c,
  cert-err34-c,
  cert-flp30-c,
  cert-err52-cpp,
  cppcoreguidelines-init-variables,
  cppcoreguidelines-narrowing-conversions,
  google-runtime-int,
  misc-confusable-identifiers,
  misc-definitions-in-headers,
  misc-header-include-cycle,
  misc-misleading-identifier,
  misc-no-recursion,
  misc-redundant-expression,
  misc-static-assert,
  misc-unused-parameters,
  modernize-use-bool-literals,
  readability-avoid-nested-conditional-operator,
  readability-avoid-return-with-void-value,
  readability-avoid-unconditional-preprocessor-if,
  readability-const-return-type,
  readability-duplicate-include,
  readability-else-after-return,
  readability-function-size,
  readability-identifier-length,
  readability-implicit-bool-conversion,
  readability-inconsistent-declaration-parameter-name,
  readability-isolate-declaration,
  readability-magic-numbers,
  readability-misleading-indentation,
  readability-misplaced-array-index,
  readability-non-const-parameter,
  readability-redundant-casting,
  readability-redundant-control-flow,
  readability-redundant-declaration,
  readability-redundant-preprocessor,
  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.deadcode.DeadStores,
  clang-analyzer.optin.core.EnumCastOutOfRange,
  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=c23', '-c', '-O0', '--pedantic', '-DDEBUG', '-D_DEBUG']
# 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:         ['h', 'cuh']

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

ImplementationFileExtensions: ['c', 'cu']

WarningsAsErrors: ''

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-assert-side-effect.AssertMacros
    value: 'assert,static_assert'
  - key: bugprone-assert-side-effect.CheckFunctionCalls
    value: false
  - key: bugprone-assert-side-effect.IgnoredFunctions
    value: ''

  - 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: google-runtime-int.UnsignedTypePrefix
    value: uint
  - key: google-runtime-int.SignedTypePrefix
    value: int
  - key: google-runtime-int.TypeSuffix
    value: 32_t

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

  - key: readability-function-size.LineThreshold
    value: 500
  - key: readability-function-size.StatementThreshold
    value: 400
  - key: readability-function-size.BranchThreshold
    value: 100
  - key: readability-function-size.ParameterThreshold
    value: 6
  - key: readability-function-size.NestingThreshold
    value: 10
  - key: readability-function-size.VariableThreshold
    value: 20

  - key: readability-identifier-length.MinimumVariableNameLength
    value: 3
  - key: readability-identifier-length.MinimumParameterNameLength
    value: 3
  - key: readability-identifier-length.IgnoredParameterNames
    value: ^[abcnxy]$
  - key: readability-identifier-length.MinimumLoopCounterNameLength
    value: 3
  - key: readability-identifier-length.IgnoredLoopCounterNames
    value: ^[ijn_]$

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

  - key: readability-magic-numbers.IgnoredIntegerValues
    value: ''
  - key: readability-magic-numbers.IgnorePowersOf2IntegerValues
    value: false
  - key: readability-magic-numbers.IgnoredFloatingPointValues
    value: ''
  - key: readability-magic-numbers.IgnoreAllFloatingPointValues
    value: false
  - key: readability-magic-numbers.IgnoreBitFieldsWidths
    value: true
  - key: readability-magic-numbers.IgnoreTypeAliases
    value: false

  - 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