.clang-tidy

---
# Configure clang-tidy for this project.

# Here is an explanation for why some of the checks are disabled:
#
#  -google-readability-namespace-comments: the *_CLIENT_NS is a macro, and
#      clang-tidy fails to match it against the initial value.
#
#  -modernize-use-trailing-return-type: clang-tidy recommends using
#      `auto Foo() -> std::string { return ...; }`, we think the code is less
#      readable in this form.
#
#  -modernize-return-braced-init-list: We think removing typenames and using
#      only braced-init can hurt readability.
#
#  -modernize-avoid-c-arrays: We only use C arrays when they seem to be the
#      right tool for the job, such as `char foo[] = "hello"`. In these cases,
#      avoiding C arrays often makes the code less readable, and std::array is
#      not a drop-in replacement because it doesn't deduce the size.
#
#  -performance-move-const-arg: This warning requires the developer to
#      know/care more about the implementation details of types/functions than
#      should be necessary. For example, `A a; F(std::move(a));` will trigger a
#      warning IFF `A` is a trivial type (and therefore the move is
#      meaningless). It would also warn if `F` accepts by `const&`, which is
#      another detail that the caller need not care about.
#
#  -readability-redundant-declaration: A friend declaration inside a class
#      counts as a declaration, so if we also declare that friend outside the
#      class in order to document it as part of the public API, that will
#      trigger a redundant declaration warning from this check.
#
#  -readability-function-cognitive-complexity: too many false positives with
#      clang-tidy-12. We need to disable this check in macros, and that setting
#      only appears in clang-tidy-13.
#
#  -bugprone-narrowing-conversions: too many false positives around
#      `std::size_t`  vs. `*::difference_type`.
#
#  -bugprone-easily-swappable-parameters: too many false positives.
#
#  -bugprone-implicit-widening-of-multiplication-result: too many false positives.
#     Almost any expression of the form `2 * variable` or `long x = a_int * b_int;`
#     generates an error.
#
Checks: >
  -*,
  abseil-*,
  bugprone-*,
  google-*,
  misc-*,
  modernize-*,
  performance-*,
  portability-*,
  readability-*,
  -google-readability-braces-around-statements,
  -google-readability-namespace-comments,
  -google-runtime-references,
  -misc-non-private-member-variables-in-classes,
  -modernize-return-braced-init-list,
  -modernize-use-trailing-return-type,
  -modernize-avoid-c-arrays,
  -performance-move-const-arg,
  -readability-braces-around-statements,
  -readability-identifier-length,
  -readability-magic-numbers,
  -readability-named-parameter,
  -readability-redundant-declaration,
  -readability-function-cognitive-complexity,
  -bugprone-narrowing-conversions,
  -bugprone-easily-swappable-parameters,
  -bugprone-implicit-widening-of-multiplication-result
  -unused-includes

HeaderFilterRegex: "(google/cloud/|generator/).*\\.h$"

CheckOptions:
  - { key: readability-identifier-naming.NamespaceCase, value: lower_case }
  - { key: readability-identifier-naming.ClassCase, value: CamelCase }
  - { key: readability-identifier-naming.StructCase, value: CamelCase }
  - {
      key: readability-identifier-naming.TemplateParameterCase,
      value: CamelCase,
    }
  - { key: readability-identifier-naming.FunctionCase, value: aNy_CasE }
  - { key: readability-identifier-naming.VariableCase, value: camelBack }
  - { key: readability-identifier-naming.ClassMemberCase, value: CamelCase }
  - { key: readability-identifier-naming.ClassMemberPrefix, value: m }
  - { key: readability-identifier-naming.PrivateMemberCase, value: CamelCase }
  - { key: readability-identifier-naming.PrivateMemberPrefix, value: p }
  - { key: readability-identifier-naming.ProtectedMemberCase, value: CamelCase }
  - { key: readability-identifier-naming.ProtectedMemberPrefix, value: p }
  - { key: readability-identifier-naming.EnumConstantCase, value: CamelCase }
  - { key: readability-identifier-naming.EnumConstantPrefix, value: k }
  - {
      key: readability-identifier-naming.ConstexprVariableCase,
      value: CamelCase,
    }
  - { key: readability-identifier-naming.ConstexprVariablePrefix, value: k }
  - { key: readability-identifier-naming.GlobalConstantCase, value: CamelCase }
  - { key: readability-identifier-naming.GlobalConstantPrefix, value: k }
  - { key: readability-identifier-naming.MemberConstantCase, value: CamelCase }
  - { key: readability-identifier-naming.MemberConstantPrefix, value: k }
  - { key: readability-identifier-naming.StaticConstantCase, value: CamelCase }
  - { key: readability-identifier-naming.StaticConstantPrefix, value: k }
  - {
      key: readability-implicit-bool-conversion.AllowIntegerConditions,
      value: 1,
    }
  - {
      key: readability-implicit-bool-conversion.AllowPointerConditions,
      value: 1,
    }
  - { key: readability-function-cognitive-complexity.IgnoreMacros, value: 1 }