clang-tools 10.0.0

UsingNamespaceDirectiveCheck.cpp
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1 //===--- UsingNamespaceDirectiveCheck.cpp - clang-tidy ----------*- C++ -*-===//
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 "UsingNamespaceDirectiveCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include "clang/ASTMatchers/ASTMatchers.h"
13
14 using namespace clang::ast_matchers;
15
16 namespace clang {
17 namespace tidy {
18 namespace google {
19 namespace build {
20
21 void UsingNamespaceDirectiveCheck::registerMatchers(
22 ast_matchers::MatchFinder *Finder) {
23 // Only register the matchers for C++; the functionality currently does not
24 // provide any benefit to other languages, despite being benign.
25 if (getLangOpts().CPlusPlus)
26 Finder->addMatcher(usingDirectiveDecl().bind("usingNamespace"), this);
27 }
28
29 void UsingNamespaceDirectiveCheck::check(
30 const MatchFinder::MatchResult &Result) {
31 const auto *U = Result.Nodes.getNodeAs<UsingDirectiveDecl>("usingNamespace");
32 SourceLocation Loc = U->getBeginLoc();
33 if (U->isImplicit() || !Loc.isValid())
34 return;
35
36 // Do not warn if namespace is a std namespace with user-defined literals. The
37 // user-defined literals can only be used with a using directive.
38 if (isStdLiteralsNamespace(U->getNominatedNamespace()))
39 return;
40
41 diag(Loc, "do not use namespace using-directives; "
42 "use using-declarations instead");
43 // TODO: We could suggest a list of using directives replacing the using
44 // namespace directive.
45 }
46
47 bool UsingNamespaceDirectiveCheck::isStdLiteralsNamespace(
48 const NamespaceDecl *NS) {
49 if (!NS->getName().endswith("literals"))
50 return false;
51
52 const auto *Parent = dyn_cast_or_null<NamespaceDecl>(NS->getParent());
53 if (!Parent)
54 return false;
55
56 if (Parent->isStdNamespace())
57 return true;
58
59 return Parent->getName() == "literals" && Parent->getParent() &&
60 Parent->getParent()->isStdNamespace();
61 }
62 } // namespace build
63 } // namespace google
64 } // namespace tidy
65 } // namespace clang
Loc
SourceLocation Loc
&#39;#&#39; location in the include directive
Definition: IncludeOrderCheck.cpp:37
clang::ast_matchers
Definition: AbseilMatcher.h:14
Parent
const Node * Parent
Definition: ExtractFunction.cpp:148
UsingNamespaceDirectiveCheck.h
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ApplyReplacements.h:27