1//===---------- NamespaceAliaser.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 "NamespaceAliaser.h"
10
11#include "ASTUtils.h"
12#include "clang/ASTMatchers/ASTMatchFinder.h"
13#include "clang/ASTMatchers/ASTMatchers.h"
14#include "clang/Lex/Lexer.h"
15#include <optional>
16namespace clang::tidy::utils {
17
18using namespace ast_matchers;
19namespace {
20AST_MATCHER_P(NamespaceAliasDecl, hasTargetNamespace,
21 ast_matchers::internal::Matcher<NamespaceDecl>, InnerMatcher) {
22 return InnerMatcher.matches(Node: *Node.getNamespace(), Finder, Builder);
23}
24} // namespace
25
26NamespaceAliaser::NamespaceAliaser(const SourceManager &SourceMgr)
27 : SourceMgr(SourceMgr) {}
28
29std::optional<FixItHint>
30NamespaceAliaser::createAlias(ASTContext &Context, const Stmt &Statement,
31 StringRef Namespace,
32 const std::vector<std::string> &Abbreviations) {
33 const FunctionDecl *Function = getSurroundingFunction(Context, Statement);
34 if (!Function || !Function->hasBody())
35 return std::nullopt;
36
37 if (AddedAliases[Function].count(Key: Namespace.str()) != 0)
38 return std::nullopt;
39
40 // FIXME: Doesn't consider the order of declarations.
41 // If we accidentally pick an alias defined later in the function,
42 // the output won't compile.
43 // FIXME: Also doesn't consider file or class-scope aliases.
44
45 const auto *ExistingAlias = selectFirst<NamedDecl>(
46 BoundTo: "alias", Results: match(Matcher: functionDecl(hasBody(InnerMatcher: compoundStmt(has(declStmt(
47 has(namespaceAliasDecl(hasTargetNamespace(InnerMatcher: hasName(
48 Name: std::string(Namespace))))
49 .bind(ID: "alias"))))))),
50 Node: *Function, Context));
51
52 if (ExistingAlias != nullptr) {
53 AddedAliases[Function][Namespace.str()] = ExistingAlias->getName().str();
54 return std::nullopt;
55 }
56
57 for (const auto &Abbreviation : Abbreviations) {
58 DeclarationMatcher ConflictMatcher = namedDecl(hasName(Name: Abbreviation));
59 const auto HasConflictingChildren =
60 !match(Matcher: findAll(Matcher: ConflictMatcher), Node: *Function, Context).empty();
61 const auto HasConflictingAncestors =
62 !match(Matcher: functionDecl(hasAncestor(decl(has(ConflictMatcher)))), Node: *Function,
63 Context)
64 .empty();
65 if (HasConflictingAncestors || HasConflictingChildren)
66 continue;
67
68 std::string Declaration =
69 (llvm::Twine("\nnamespace ") + Abbreviation + " = " + Namespace + ";")
70 .str();
71 SourceLocation Loc =
72 Lexer::getLocForEndOfToken(Loc: Function->getBody()->getBeginLoc(), Offset: 0,
73 SM: SourceMgr, LangOpts: Context.getLangOpts());
74 AddedAliases[Function][Namespace.str()] = Abbreviation;
75 return FixItHint::CreateInsertion(InsertionLoc: Loc, Code: Declaration);
76 }
77
78 return std::nullopt;
79}
80
81std::string NamespaceAliaser::getNamespaceName(ASTContext &Context,
82 const Stmt &Statement,
83 StringRef Namespace) const {
84 const auto *Function = getSurroundingFunction(Context, Statement);
85 auto FunctionAliases = AddedAliases.find(Val: Function);
86 if (FunctionAliases != AddedAliases.end()) {
87 if (FunctionAliases->second.count(Key: Namespace) != 0) {
88 return FunctionAliases->second.find(Key: Namespace)->getValue();
89 }
90 }
91 return Namespace.str();
92}
93
94} // namespace clang::tidy::utils
95

source code of clang-tools-extra/clang-tidy/utils/NamespaceAliaser.cpp