xref: /llvm-project/clang-tools-extra/clang-tidy/modernize/DeprecatedIosBaseAliasesCheck.cpp (revision 7d2ea6c422d3f5712b7253407005e1a465a76946)
1 //===--- DeprecatedIosBaseAliasesCheck.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 "DeprecatedIosBaseAliasesCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include <optional>
13 
14 using namespace clang::ast_matchers;
15 
16 namespace clang::tidy::modernize {
17 
18 static constexpr std::array<StringRef, 5> DeprecatedTypes = {
19     "::std::ios_base::io_state", "::std::ios_base::open_mode",
20     "::std::ios_base::seek_dir", "::std::ios_base::streamoff",
21     "::std::ios_base::streampos"};
22 
getReplacementType(StringRef Type)23 static std::optional<const char *> getReplacementType(StringRef Type) {
24   return llvm::StringSwitch<std::optional<const char *>>(Type)
25       .Case("io_state", "iostate")
26       .Case("open_mode", "openmode")
27       .Case("seek_dir", "seekdir")
28       .Default(std::nullopt);
29 }
30 
registerMatchers(MatchFinder * Finder)31 void DeprecatedIosBaseAliasesCheck::registerMatchers(MatchFinder *Finder) {
32   auto IoStateDecl = typedefDecl(hasAnyName(DeprecatedTypes)).bind("TypeDecl");
33   auto IoStateType =
34       qualType(hasDeclaration(IoStateDecl), unless(elaboratedType()));
35 
36   Finder->addMatcher(typeLoc(loc(IoStateType)).bind("TypeLoc"), this);
37 }
38 
check(const MatchFinder::MatchResult & Result)39 void DeprecatedIosBaseAliasesCheck::check(
40     const MatchFinder::MatchResult &Result) {
41   SourceManager &SM = *Result.SourceManager;
42 
43   const auto *Typedef = Result.Nodes.getNodeAs<TypedefDecl>("TypeDecl");
44   StringRef TypeName = Typedef->getName();
45   auto Replacement = getReplacementType(TypeName);
46 
47   const auto *TL = Result.Nodes.getNodeAs<TypeLoc>("TypeLoc");
48   SourceLocation IoStateLoc = TL->getBeginLoc();
49 
50   // Do not generate fixits for matches depending on template arguments and
51   // macro expansions.
52   bool Fix = Replacement && !TL->getType()->isDependentType();
53   if (IoStateLoc.isMacroID()) {
54     IoStateLoc = SM.getSpellingLoc(IoStateLoc);
55     Fix = false;
56   }
57 
58   SourceLocation EndLoc = IoStateLoc.getLocWithOffset(TypeName.size() - 1);
59 
60   if (Replacement) {
61     const char *FixName = *Replacement;
62     auto Builder = diag(IoStateLoc, "'std::ios_base::%0' is deprecated; use "
63                                     "'std::ios_base::%1' instead")
64                    << TypeName << FixName;
65 
66     if (Fix)
67       Builder << FixItHint::CreateReplacement(SourceRange(IoStateLoc, EndLoc),
68                                               FixName);
69   } else
70     diag(IoStateLoc, "'std::ios_base::%0' is deprecated") << TypeName;
71 }
72 
73 } // namespace clang::tidy::modernize
74