clang-tools  9.0.0
ConcatNestedNamespacesCheck.cpp
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1 //===--- ConcatNestedNamespacesCheck.cpp - clang-tidy----------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include <algorithm>
13 #include <iterator>
14 
15 namespace clang {
16 namespace tidy {
17 namespace modernize {
18 
19 static bool locationsInSameFile(const SourceManager &Sources,
20  SourceLocation Loc1, SourceLocation Loc2) {
21  return Loc1.isFileID() && Loc2.isFileID() &&
22  Sources.getFileID(Loc1) == Sources.getFileID(Loc2);
23 }
24 
25 static bool anonymousOrInlineNamespace(const NamespaceDecl &ND) {
26  return ND.isAnonymousNamespace() || ND.isInlineNamespace();
27 }
28 
29 static bool singleNamedNamespaceChild(const NamespaceDecl &ND) {
30  NamespaceDecl::decl_range Decls = ND.decls();
31  if (std::distance(Decls.begin(), Decls.end()) != 1)
32  return false;
33 
34  const auto *ChildNamespace = dyn_cast<const NamespaceDecl>(*Decls.begin());
35  return ChildNamespace && !anonymousOrInlineNamespace(*ChildNamespace);
36 }
37 
38 static bool alreadyConcatenated(std::size_t NumCandidates,
39  const SourceRange &ReplacementRange,
40  const SourceManager &Sources,
41  const LangOptions &LangOpts) {
42  // FIXME: This logic breaks when there is a comment with ':'s in the middle.
43  CharSourceRange TextRange =
44  Lexer::getAsCharRange(ReplacementRange, Sources, LangOpts);
45  StringRef CurrentNamespacesText =
46  Lexer::getSourceText(TextRange, Sources, LangOpts);
47  return CurrentNamespacesText.count(':') == (NumCandidates - 1) * 2;
48 }
49 
50 ConcatNestedNamespacesCheck::NamespaceString
51 ConcatNestedNamespacesCheck::concatNamespaces() {
52  NamespaceString Result("namespace ");
53  Result.append(Namespaces.front()->getName());
54 
55  std::for_each(std::next(Namespaces.begin()), Namespaces.end(),
56  [&Result](const NamespaceDecl *ND) {
57  Result.append("::");
58  Result.append(ND->getName());
59  });
60 
61  return Result;
62 }
63 
65  ast_matchers::MatchFinder *Finder) {
66  if (!getLangOpts().CPlusPlus17)
67  return;
68 
69  Finder->addMatcher(ast_matchers::namespaceDecl().bind("namespace"), this);
70 }
71 
72 void ConcatNestedNamespacesCheck::reportDiagnostic(
73  const SourceRange &FrontReplacement, const SourceRange &BackReplacement) {
74  diag(Namespaces.front()->getBeginLoc(),
75  "nested namespaces can be concatenated", DiagnosticIDs::Warning)
76  << FixItHint::CreateReplacement(FrontReplacement, concatNamespaces())
77  << FixItHint::CreateReplacement(BackReplacement, "}");
78 }
79 
81  const ast_matchers::MatchFinder::MatchResult &Result) {
82  const NamespaceDecl &ND = *Result.Nodes.getNodeAs<NamespaceDecl>("namespace");
83  const SourceManager &Sources = *Result.SourceManager;
84 
85  if (!locationsInSameFile(Sources, ND.getBeginLoc(), ND.getRBraceLoc()))
86  return;
87 
88  if (!Sources.isInMainFile(ND.getBeginLoc()))
89  return;
90 
92  return;
93 
94  Namespaces.push_back(&ND);
95 
97  return;
98 
99  SourceRange FrontReplacement(Namespaces.front()->getBeginLoc(),
100  Namespaces.back()->getLocation());
101  SourceRange BackReplacement(Namespaces.back()->getRBraceLoc(),
102  Namespaces.front()->getRBraceLoc());
103 
104  if (!alreadyConcatenated(Namespaces.size(), FrontReplacement, Sources,
105  getLangOpts()))
106  reportDiagnostic(FrontReplacement, BackReplacement);
107 
108  Namespaces.clear();
109 }
110 
111 } // namespace modernize
112 } // namespace tidy
113 } // namespace clang
const LangOptions & getLangOpts() const
Returns the language options from the context.
void check(const ast_matchers::MatchFinder::MatchResult &Result) override
ClangTidyChecks that register ASTMatchers should do the actual work in here.
static bool alreadyConcatenated(std::size_t NumCandidates, const SourceRange &ReplacementRange, const SourceManager &Sources, const LangOptions &LangOpts)
static bool anonymousOrInlineNamespace(const NamespaceDecl &ND)
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
llvm::Optional< llvm::Expected< tooling::AtomicChanges > > Result
Definition: Rename.cpp:36
static bool singleNamedNamespaceChild(const NamespaceDecl &ND)
static bool locationsInSameFile(const SourceManager &Sources, SourceLocation Loc1, SourceLocation Loc2)
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
Add a diagnostic with the check&#39;s name.
void registerMatchers(ast_matchers::MatchFinder *Finder) override
Override this to register AST matchers with Finder.