Unverified Commit 24479395 authored by Dmitrii Kuragin's avatar Dmitrii Kuragin Committed by GitHub
Browse files

[Clang-Tidy] Skip `misc-unused-parameters` in macro. (#194999) 



The new parameter allows to skip the check for the cases when we need to
use the macro, but there is no immediate way to fix the macro itself. It
recently come up with a gradual adoption of clang-tidy and not all parts
of the code could be fixed at once.

Simply enabling it using `clang-tidy-diff` is not enough, since
`misc-unused-parameters` would cause false-positive, since the given
diff didn't introduce the unused parameters and might be not easy to
change.

The given parameters allow for better incremental adoption.

---------

Co-authored-by: default avatarDmitrii Kuragin <dkuragin@adobe.com>
Co-authored-by: default avatarEugeneZelenko <eugene.zelenko@gmail.com>
parent 1b1e14f1

clang-tools-extra/clang-tidy/misc/UnusedParametersCheck.cpp

+5 −1
Original line number Diff line number Diff line
@@ -130,11 +130,13 @@ UnusedParametersCheck::UnusedParametersCheck(StringRef Name, 
                                             ClangTidyContext *Context)

    : ClangTidyCheck(Name, Context),

      StrictMode(Options.get("StrictMode", false)),

      IgnoreVirtual(Options.get("IgnoreVirtual", false)) {}

      IgnoreVirtual(Options.get("IgnoreVirtual", false)),

      IgnoreMacroParameters(Options.get("IgnoreMacroParameters", false)) {}



void UnusedParametersCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {

  Options.store(Opts, "StrictMode", StrictMode);

  Options.store(Opts, "IgnoreVirtual", IgnoreVirtual);

  Options.store(Opts, "IgnoreMacroParameters", IgnoreMacroParameters);

}



void UnusedParametersCheck::warnOnUnusedParameter(
@@ -198,6 +200,8 @@ void UnusedParametersCheck::check(const MatchFinder::MatchResult &Result) { 
      // type if we remove the preceding parameter name.

      continue;

    }

    if (IgnoreMacroParameters && Param->getLocation().isMacroID())

      continue;



    // In non-strict mode ignore function definitions with empty bodies

    // (constructor initializer counts for non-empty body).

clang-tools-extra/clang-tidy/misc/UnusedParametersCheck.h

+1 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ public: 
private:

  const bool StrictMode;

  const bool IgnoreVirtual;

  const bool IgnoreMacroParameters;

  class IndexerVisitor;

  std::unique_ptr<IndexerVisitor> Indexer;

clang-tools-extra/docs/ReleaseNotes.rst

+5 −0
Original line number Diff line number Diff line
@@ -393,6 +393,11 @@ Changes in existing checks 
  - Fixed the `CheckThrowTemporaries` option to correctly reflect its

    configured value in exported settings.



- Improved :doc:`misc-unused-parameters

  <clang-tidy/checks/misc/unused-parameters>` check by adding

  `IgnoreMacroParameters` option to suppress warnings for unused parameters

  whose declarations originate from macro expansions.



- Improved :doc:`misc-unused-using-decls

  <clang-tidy/checks/misc/unused-using-decls>` to not diagnose ``using``

  declarations as unused if they're exported from a module.

clang-tools-extra/docs/clang-tidy/checks/misc/unused-parameters.rst

+8 −0
Original line number Diff line number Diff line
@@ -45,3 +45,11 @@ Options 


  Determines whether virtual method parameters should be inspected.

  Set to `true` to ignore them. Default is `false`.



.. option:: IgnoreMacroParameters



  When `true`, the check will not report unused parameters whose declarations

  originate from a macro expansion. This suppresses false positives in code

  that uses macros to define function signatures where parameters are

  structurally required by the macro but not used in every expansion.

  Default is `false`.

clang-tools-extra/test/clang-tidy/checkers/misc/unused-parameters-macro.cpp

0 → 100644
+21 −0
Original line number Diff line number Diff line 
// RUN: %check_clang_tidy %s misc-unused-parameters %t -- \

// RUN:   -config="{CheckOptions: {misc-unused-parameters.IgnoreMacroParameters: true, \

// RUN:             misc-unused-parameters.StrictMode: true}}" --



// Parameters declared inside a macro expansion should not be reported when

// IgnoreMacroParameters is enabled.



#define HANDLER(RetType, ParamType, ParamName) \

  RetType handler_##ParamName(ParamType ParamName) { return 0; }



HANDLER(int, int, unused_from_macro)

// No warning: parameter comes from macro expansion.



#define WRAP_PARAM(type) type macro_arg

void functionWithMacroParam(WRAP_PARAM(int)) {}

// No warning: parameter name comes from macro expansion.



// Regular unused parameter should still be reported.

void normalFunction(int unused_normal) {}

// CHECK-MESSAGES: :[[@LINE-1]]:25: warning: parameter 'unused_normal' is unused [misc-unused-parameters]

// CHECK-FIXES: void normalFunction(int  /*unused_normal*/) {}