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 namespace clang {
16 namespace tidy {
17 namespace utils {
18
19 using namespace ast_matchers;
20
NamespaceAliaser(const SourceManager & SourceMgr)21 NamespaceAliaser::NamespaceAliaser(const SourceManager &SourceMgr)
22 : SourceMgr(SourceMgr) {}
23
AST_MATCHER_P(NamespaceAliasDecl,hasTargetNamespace,ast_matchers::internal::Matcher<NamespaceDecl>,innerMatcher)24 AST_MATCHER_P(NamespaceAliasDecl, hasTargetNamespace,
25 ast_matchers::internal::Matcher<NamespaceDecl>, innerMatcher) {
26 return innerMatcher.matches(*Node.getNamespace(), Finder, Builder);
27 }
28
29 Optional<FixItHint>
createAlias(ASTContext & Context,const Stmt & Statement,StringRef Namespace,const std::vector<std::string> & Abbreviations)30 NamespaceAliaser::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 None;
36
37 if (AddedAliases[Function].count(Namespace.str()) != 0)
38 return None;
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 "alias", match(functionDecl(hasBody(compoundStmt(has(declStmt(
47 has(namespaceAliasDecl(hasTargetNamespace(hasName(
48 std::string(Namespace))))
49 .bind("alias"))))))),
50 *Function, Context));
51
52 if (ExistingAlias != nullptr) {
53 AddedAliases[Function][Namespace.str()] = ExistingAlias->getName().str();
54 return None;
55 }
56
57 for (const auto &Abbreviation : Abbreviations) {
58 DeclarationMatcher ConflictMatcher = namedDecl(hasName(Abbreviation));
59 const auto HasConflictingChildren =
60 !match(findAll(ConflictMatcher), *Function, Context).empty();
61 const auto HasConflictingAncestors =
62 !match(functionDecl(hasAncestor(decl(has(ConflictMatcher)))), *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(Function->getBody()->getBeginLoc(), 0,
73 SourceMgr, Context.getLangOpts());
74 AddedAliases[Function][Namespace.str()] = Abbreviation;
75 return FixItHint::CreateInsertion(Loc, Declaration);
76 }
77
78 return None;
79 }
80
getNamespaceName(ASTContext & Context,const Stmt & Statement,StringRef Namespace) const81 std::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(Function);
86 if (FunctionAliases != AddedAliases.end()) {
87 if (FunctionAliases->second.count(Namespace) != 0) {
88 return FunctionAliases->second.find(Namespace)->getValue();
89 }
90 }
91 return Namespace.str();
92 }
93
94 } // namespace utils
95 } // namespace tidy
96 } // namespace clang
97