.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.
#
#  -bugprone-unchecked-optional-access: too many false positives in tests.
#     Despite what the documentation says, this warning appears after
#     `ASSERT_TRUE(variable)` or `ASSERT_TRUE(variable.has_value())`.
#
Checks: >
  -*,
  abseil-*,
  bugprone-*,
  google-*,
  misc-*,
  modernize-*,
  performance-*,
  portability-*,
  readability-*,
  cppcoreguidelines-avoid-do-while,
  cppcoreguidelines-avoid-goto,
  cppcoreguidelines-avoid-non-const-global-variables,
  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-malloc,
  cppcoreguidelines-prefer-member-initializer,
  cppcoreguidelines-pro-type-cstyle-cast,
  cppcoreguidelines-pro-type-member-init,
  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-readability-braces-around-statements,
  -google-readability-todo,
  -google-readability-namespace-comments,
  -google-runtime-references,
  -misc-non-private-member-variables-in-classes,
  -misc-const-correctness,
  -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,
  -readability-simplify-boolean-expr,
  -bugprone-narrowing-conversions,
  -bugprone-easily-swappable-parameters,
  -bugprone-implicit-widening-of-multiplication-result,
  -bugprone-unchecked-optional-access,
  cppcoreguidelines-pro-type-const-cast,
  cppcoreguidelines-pro-type-reinterpret-cast,
  cppcoreguidelines-pro-type-static-cast-downcast,

# Turn all the warnings from the checks above into errors.
WarningsAsErrors: "*"

HeaderFilterRegex: ".*\\.hh$"

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: camelBack  }
  - { key: readability-identifier-naming.VariableCase,           value: lower_case }
  - { key: readability-identifier-naming.ClassMemberCase,        value: lower_case }
  - { key: readability-identifier-naming.ClassMemberSuffix,      value: _          }
  - { key: readability-identifier-naming.PrivateMemberSuffix,    value: _          }
  - { key: readability-identifier-naming.ProtectedMemberSuffix,  value: _          }
  - { key: readability-identifier-naming.EnumConstantCase,         value: CamelCase }
  - { key: readability-identifier-naming.EnumConstantPrefix,       value: k         }
  - { key: readability-identifier-naming.ConstexprVariableCase,    value: Camel_Snake_Case }
  - { key: readability-identifier-naming.ConstexprVariablePrefix,  value: k         }
  - { key: readability-identifier-naming.GlobalConstantCase,       value: Camel_Snake_Case }
  - { 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   }