Commit 50e99563 authored by Mitchell Balan's avatar Mitchell Balan
Browse files

[clang-tidy] modernize-use-override new option AllowOverrideAndFinal 

Summary:
In addition to adding `override` wherever possible, clang-tidy's `modernize-use-override` nicely removes `virtual` when `override` or `final` is specified, and further removes override when final is specified. While this is great default behavior, when code needs to be compiled with gcc at high warning levels that include `gcc -Wsuggest-override` or `gcc -Werror=suggest-override`, clang-tidy's removal of the redundant `override` keyword causes gcc to emit a warning or error. This discrepancy / conflict has been noted by others including a comment on Stack Overflow and by Mozilla's Firefox developers.

This patch adds an AllowOverrideAndFinal option defaulting to 0 - thus preserving current behavior - that when enabled allows both `override` and `final` to co-exist, while still fixing all other issues.

The patch includes a test file verifying all combinations of virtual/override/final, and mentions the new option in the release notes.

Reviewers: alexfh, djasper, JonasToth

Patch by: poelmanc

Subscribers: JonasToth, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D70165
parent ee0882bd

clang-tools-extra/clang-tidy/readability/RedundantStringInitCheck.cpp

+13 −13
Original line number Diff line number Diff line
@@ -46,23 +46,23 @@ void RedundantStringInitCheck::registerMatchers(MatchFinder *Finder) { 
  //     string bar("");

  Finder->addMatcher(

      namedDecl(

          varDecl(hasType(hasUnqualifiedDesugaredType(recordType(

          varDecl(

              hasType(hasUnqualifiedDesugaredType(recordType(

                  hasDeclaration(cxxRecordDecl(hasName("basic_string")))))),

              hasInitializer(expr(ignoringImplicit(anyOf(

                                          EmptyStringCtorExpr,

                                          EmptyStringCtorExprWithTemporaries)))

                                     .bind("expr"))),

          unless(parmVarDecl()))

          .bind("decl"),

                  EmptyStringCtorExpr, EmptyStringCtorExprWithTemporaries)))))

              .bind("vardecl"),

          unless(parmVarDecl())),

      this);

}



void RedundantStringInitCheck::check(const MatchFinder::MatchResult &Result) {

  const auto *CtorExpr = Result.Nodes.getNodeAs<Expr>("expr");

  const auto *Decl = Result.Nodes.getNodeAs<NamedDecl>("decl");

  diag(CtorExpr->getExprLoc(), "redundant string initialization")

      << FixItHint::CreateReplacement(CtorExpr->getSourceRange(),

                                      Decl->getName());

  const auto *VDecl = Result.Nodes.getNodeAs<VarDecl>("vardecl");

  // VarDecl's getSourceRange() spans 'string foo = ""' or 'string bar("")'.

  // So start at getLocation() to span just 'foo = ""' or 'bar("")'.

  SourceRange ReplaceRange(VDecl->getLocation(), VDecl->getEndLoc());

  diag(VDecl->getLocation(), "redundant string initialization")

      << FixItHint::CreateReplacement(ReplaceRange, VDecl->getName());

}



} // namespace readability

clang-tools-extra/test/clang-tidy/checkers/readability-redundant-string-init-msvc.cpp

+1 −2
Original line number Diff line number Diff line 
// RUN: %check_clang_tidy -std=c++11,c++14 %s readability-redundant-string-init %t

// FIXME: Fix the checker to work in C++17 mode.

// RUN: %check_clang_tidy %s readability-redundant-string-init %t



namespace std {

template <typename T>

clang-tools-extra/test/clang-tidy/checkers/readability-redundant-string-init.cpp

+6 −2
Original line number Diff line number Diff line 
// RUN: %check_clang_tidy -std=c++11,c++14 %s readability-redundant-string-init %t

// FIXME: Fix the checker to work in C++17 mode.

// RUN: %check_clang_tidy %s readability-redundant-string-init %t



namespace std {

template <typename T>
@@ -131,6 +130,11 @@ void k() { 
  // CHECK-FIXES: std::string a, b, c;



  std::string d = "u", e = "u", f = "u";



  std::string g = "u", h = "", i = "uuu", j = "", k;

  // CHECK-MESSAGES: [[@LINE-1]]:24: warning: redundant string initialization

  // CHECK-MESSAGES: [[@LINE-2]]:43: warning: redundant string initialization

  // CHECK-FIXES: std::string g = "u", h, i = "uuu", j, k;

}



// These cases should not generate warnings.