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>
16 namespace clang::tidy::utils {
17
18 using namespace ast_matchers;
19
NamespaceAliaser(const SourceManager & SourceMgr)20 NamespaceAliaser::NamespaceAliaser(const SourceManager &SourceMgr)
21 : SourceMgr(SourceMgr) {}
22
AST_MATCHER_P(NamespaceAliasDecl,hasTargetNamespace,ast_matchers::internal::Matcher<NamespaceDecl>,innerMatcher)23 AST_MATCHER_P(NamespaceAliasDecl, hasTargetNamespace,
24 ast_matchers::internal::Matcher<NamespaceDecl>, innerMatcher) {
25 return innerMatcher.matches(*Node.getNamespace(), Finder, Builder);
26 }
27
28 std::optional<FixItHint>
createAlias(ASTContext & Context,const Stmt & Statement,StringRef Namespace,const std::vector<std::string> & Abbreviations)29 NamespaceAliaser::createAlias(ASTContext &Context, const Stmt &Statement,
30 StringRef Namespace,
31 const std::vector<std::string> &Abbreviations) {
32 const FunctionDecl *Function = getSurroundingFunction(Context, Statement);
33 if (!Function || !Function->hasBody())
34 return std::nullopt;
35
36 if (AddedAliases[Function].count(Namespace.str()) != 0)
37 return std::nullopt;
38
39 // FIXME: Doesn't consider the order of declarations.
40 // If we accidentally pick an alias defined later in the function,
41 // the output won't compile.
42 // FIXME: Also doesn't consider file or class-scope aliases.
43
44 const auto *ExistingAlias = selectFirst<NamedDecl>(
45 "alias", match(functionDecl(hasBody(compoundStmt(has(declStmt(
46 has(namespaceAliasDecl(hasTargetNamespace(hasName(
47 std::string(Namespace))))
48 .bind("alias"))))))),
49 *Function, Context));
50
51 if (ExistingAlias != nullptr) {
52 AddedAliases[Function][Namespace.str()] = ExistingAlias->getName().str();
53 return std::nullopt;
54 }
55
56 for (const auto &Abbreviation : Abbreviations) {
57 DeclarationMatcher ConflictMatcher = namedDecl(hasName(Abbreviation));
58 const auto HasConflictingChildren =
59 !match(findAll(ConflictMatcher), *Function, Context).empty();
60 const auto HasConflictingAncestors =
61 !match(functionDecl(hasAncestor(decl(has(ConflictMatcher)))), *Function,
62 Context)
63 .empty();
64 if (HasConflictingAncestors || HasConflictingChildren)
65 continue;
66
67 std::string Declaration =
68 (llvm::Twine("\nnamespace ") + Abbreviation + " = " + Namespace + ";")
69 .str();
70 SourceLocation Loc =
71 Lexer::getLocForEndOfToken(Function->getBody()->getBeginLoc(), 0,
72 SourceMgr, Context.getLangOpts());
73 AddedAliases[Function][Namespace.str()] = Abbreviation;
74 return FixItHint::CreateInsertion(Loc, Declaration);
75 }
76
77 return std::nullopt;
78 }
79
getNamespaceName(ASTContext & Context,const Stmt & Statement,StringRef Namespace) const80 std::string NamespaceAliaser::getNamespaceName(ASTContext &Context,
81 const Stmt &Statement,
82 StringRef Namespace) const {
83 const auto *Function = getSurroundingFunction(Context, Statement);
84 auto FunctionAliases = AddedAliases.find(Function);
85 if (FunctionAliases != AddedAliases.end()) {
86 if (FunctionAliases->second.count(Namespace) != 0) {
87 return FunctionAliases->second.find(Namespace)->getValue();
88 }
89 }
90 return Namespace.str();
91 }
92
93 } // namespace clang::tidy::utils
94