clang-tools 10.0.0

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
9 #include "ConcatNestedNamespacesCheck.h"
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
64 void ConcatNestedNamespacesCheck::registerMatchers(
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
80 void ConcatNestedNamespacesCheck::check(
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
91 if (anonymousOrInlineNamespace(ND))
92 return;
93
94 Namespaces.push_back(&ND);
95
96 if (singleNamedNamespaceChild(ND))
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
clang::tidy::ClangTidyCheck::getLangOpts
const LangOptions & getLangOpts() const
Returns the language options from the context.
Definition: ClangTidyCheck.h:188
clang::tidy::modernize::ConcatNestedNamespacesCheck::check
void check(const ast_matchers::MatchFinder::MatchResult &Result) override
ClangTidyChecks that register ASTMatchers should do the actual work in here.
Definition: ConcatNestedNamespacesCheck.cpp:80
clang::tidy::modernize::alreadyConcatenated
static bool alreadyConcatenated(std::size_t NumCandidates, const SourceRange &ReplacementRange, const SourceManager &Sources, const LangOptions &LangOpts)
Definition: ConcatNestedNamespacesCheck.cpp:38
clang::tidy::modernize::anonymousOrInlineNamespace
static bool anonymousOrInlineNamespace(const NamespaceDecl &ND)
Definition: ConcatNestedNamespacesCheck.cpp:25
ConcatNestedNamespacesCheck.h
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ApplyReplacements.h:27
clang::tidy::modernize::singleNamedNamespaceChild
static bool singleNamedNamespaceChild(const NamespaceDecl &ND)
Definition: ConcatNestedNamespacesCheck.cpp:29
clang::tidy::modernize::locationsInSameFile
static bool locationsInSameFile(const SourceManager &Sources, SourceLocation Loc1, SourceLocation Loc2)
Definition: ConcatNestedNamespacesCheck.cpp:19
clang::tidy::ClangTidyCheck::diag
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
Add a diagnostic with the check&#39;s name.
Definition: ClangTidyCheck.cpp:21
clang::tidy::modernize::ConcatNestedNamespacesCheck::registerMatchers
void registerMatchers(ast_matchers::MatchFinder *Finder) override
Override this to register AST matchers with Finder.
Definition: ConcatNestedNamespacesCheck.cpp:64