clang-tools  5.0.0
RedundantDeclarationCheck.cpp
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1 //===--- RedundantDeclarationCheck.cpp - clang-tidy------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
11 #include "clang/AST/ASTContext.h"
12 #include "clang/ASTMatchers/ASTMatchFinder.h"
13 #include "clang/Lex/Lexer.h"
14 
15 using namespace clang::ast_matchers;
16 
17 namespace clang {
18 namespace tidy {
19 namespace readability {
20 
21 void RedundantDeclarationCheck::registerMatchers(MatchFinder *Finder) {
22  Finder->addMatcher(
23  namedDecl(
24  anyOf(varDecl(unless(isDefinition())),
25  functionDecl(unless(anyOf(isDefinition(), isDefaulted())))))
26  .bind("Decl"),
27  this);
28 }
29 
30 void RedundantDeclarationCheck::check(const MatchFinder::MatchResult &Result) {
31  const auto *D = Result.Nodes.getNodeAs<NamedDecl>("Decl");
32  const auto *Prev = D->getPreviousDecl();
33  if (!Prev)
34  return;
35  if (!Prev->getLocation().isValid())
36  return;
37  if (Prev->getLocation() == D->getLocation())
38  return;
39 
40  const SourceManager &SM = *Result.SourceManager;
41 
42  const bool DifferentHeaders =
43  !SM.isInMainFile(D->getLocation()) &&
44  !SM.isWrittenInSameFile(Prev->getLocation(), D->getLocation());
45 
46  bool MultiVar = false;
47  if (const auto *VD = dyn_cast<VarDecl>(D)) {
48  // Is this a multivariable declaration?
49  for (const auto Other : VD->getDeclContext()->decls()) {
50  if (Other != D && Other->getLocStart() == VD->getLocStart()) {
51  MultiVar = true;
52  break;
53  }
54  }
55  }
56 
57  SourceLocation EndLoc = Lexer::getLocForEndOfToken(
58  D->getSourceRange().getEnd(), 0, SM, Result.Context->getLangOpts());
59  {
60  auto Diag = diag(D->getLocation(), "redundant %0 declaration") << D;
61  if (!MultiVar && !DifferentHeaders)
62  Diag << FixItHint::CreateRemoval(
63  SourceRange(D->getSourceRange().getBegin(), EndLoc));
64  }
65  diag(Prev->getLocation(), "previously declared here", DiagnosticIDs::Note);
66 }
67 
68 } // namespace readability
69 } // namespace tidy
70 } // namespace clang
std::unique_ptr< ast_matchers::MatchFinder > Finder
Definition: ClangTidy.cpp:275
SourceManager & SM