llvm-project/clang-tools-extra/clang-tidy/modernize/ConcatNestedNamespacesCheck...

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//===--- ConcatNestedNamespacesCheck.cpp - clang-tidy----------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "ConcatNestedNamespacesCheck.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include <algorithm>
#include <iterator>
namespace clang {
namespace tidy {
namespace modernize {
static bool locationsInSameFile(const SourceManager &Sources,
SourceLocation Loc1, SourceLocation Loc2) {
return Loc1.isFileID() && Loc2.isFileID() &&
Sources.getFileID(Loc1) == Sources.getFileID(Loc2);
}
static bool anonymousOrInlineNamespace(const NamespaceDecl &ND) {
return ND.isAnonymousNamespace() || ND.isInlineNamespace();
}
static bool singleNamedNamespaceChild(const NamespaceDecl &ND) {
NamespaceDecl::decl_range Decls = ND.decls();
if (std::distance(Decls.begin(), Decls.end()) != 1)
return false;
const auto *ChildNamespace = dyn_cast<const NamespaceDecl>(*Decls.begin());
return ChildNamespace && !anonymousOrInlineNamespace(*ChildNamespace);
}
static bool alreadyConcatenated(std::size_t NumCandidates,
const SourceRange &ReplacementRange,
const SourceManager &Sources,
const LangOptions &LangOpts) {
CharSourceRange TextRange =
Lexer::getAsCharRange(ReplacementRange, Sources, LangOpts);
StringRef CurrentNamespacesText =
Lexer::getSourceText(TextRange, Sources, LangOpts);
return CurrentNamespacesText.count(':') == (NumCandidates - 1) * 2;
}
ConcatNestedNamespacesCheck::NamespaceString
ConcatNestedNamespacesCheck::concatNamespaces() {
NamespaceString Result("namespace ");
Result.append(Namespaces.front()->getName());
std::for_each(std::next(Namespaces.begin()), Namespaces.end(),
[&Result](const NamespaceDecl *ND) {
Result.append("::");
Result.append(ND->getName());
});
return Result;
}
void ConcatNestedNamespacesCheck::registerMatchers(
ast_matchers::MatchFinder *Finder) {
if (!getLangOpts().CPlusPlus17)
return;
Finder->addMatcher(ast_matchers::namespaceDecl().bind("namespace"), this);
}
void ConcatNestedNamespacesCheck::reportDiagnostic(
const SourceRange &FrontReplacement, const SourceRange &BackReplacement) {
diag(Namespaces.front()->getBeginLoc(),
"nested namespaces can be concatenated", DiagnosticIDs::Warning)
<< FixItHint::CreateReplacement(FrontReplacement, concatNamespaces())
<< FixItHint::CreateReplacement(BackReplacement, "}");
}
void ConcatNestedNamespacesCheck::check(
const ast_matchers::MatchFinder::MatchResult &Result) {
const NamespaceDecl &ND = *Result.Nodes.getNodeAs<NamespaceDecl>("namespace");
const SourceManager &Sources = *Result.SourceManager;
if (!locationsInSameFile(Sources, ND.getBeginLoc(), ND.getRBraceLoc()))
return;
if (!Sources.isInMainFile(ND.getBeginLoc()))
return;
if (anonymousOrInlineNamespace(ND))
return;
Namespaces.push_back(&ND);
if (singleNamedNamespaceChild(ND))
return;
SourceRange FrontReplacement(Namespaces.front()->getBeginLoc(),
Namespaces.back()->getLocation());
SourceRange BackReplacement(Namespaces.back()->getRBraceLoc(),
Namespaces.front()->getRBraceLoc());
if (!alreadyConcatenated(Namespaces.size(), FrontReplacement, Sources,
getLangOpts()))
reportDiagnostic(FrontReplacement, BackReplacement);
Namespaces.clear();
}
} // namespace modernize
} // namespace tidy
} // namespace clang