clang-tools-extra/clang-tidy/readability/DuplicateIncludeCheck.cpp

   1 //===--- DuplicateIncludeCheck.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 "DuplicateIncludeCheck.h"
  10 #include "clang/Frontend/CompilerInstance.h"
  11 #include "clang/Lex/Preprocessor.h"
  12 #include "llvm/ADT/STLExtras.h"
  13 #include "llvm/ADT/SmallVector.h"
  14 #include <memory>
  15
  16 namespace clang {
  17 namespace tidy {
  18 namespace readability {
  19
  20 static SourceLocation advanceBeyondCurrentLine(const SourceManager &SM,
  21                                                SourceLocation Start,
  22                                                int Offset) {
  23   const FileID Id = SM.getFileID(Start);
  24   const unsigned LineNumber = SM.getSpellingLineNumber(Start);
  25   while (SM.getFileID(Start) == Id &&
  26          SM.getSpellingLineNumber(Start.getLocWithOffset(Offset)) == LineNumber)
  27     Start = Start.getLocWithOffset(Offset);
  28   return Start;
  29 }
  30
  31 namespace {
  32
  33 using FileList = SmallVector<StringRef>;
  34
  35 class DuplicateIncludeCallbacks : public PPCallbacks {
  36 public:
  37   DuplicateIncludeCallbacks(DuplicateIncludeCheck &Check,
  38                             const SourceManager &SM)
  39       : Check(Check), SM(SM) {
  40     // The main file doesn't participate in the FileChanged notification.
  41     Files.emplace_back();
  42   }
  43
  44   void FileChanged(SourceLocation Loc, FileChangeReason Reason,
  45                    SrcMgr::CharacteristicKind FileType,
  46                    FileID PrevFID) override;
  47
  48   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
  49                           StringRef FileName, bool IsAngled,
  50                           CharSourceRange FilenameRange,
  51                           Optional<FileEntryRef> File, StringRef SearchPath,
  52                           StringRef RelativePath, const Module *Imported,
  53                           SrcMgr::CharacteristicKind FileType) override;
  54
  55   void MacroDefined(const Token &MacroNameTok,
  56                     const MacroDirective *MD) override;
  57
  58   void MacroUndefined(const Token &MacroNameTok, const MacroDefinition &MD,
  59                       const MacroDirective *Undef) override;
  60
  61 private:
  62   // A list of included files is kept for each file we enter.
  63   SmallVector<FileList> Files;
  64   DuplicateIncludeCheck &Check;
  65   const SourceManager &SM;
  66 };
  67
  68 void DuplicateIncludeCallbacks::FileChanged(SourceLocation Loc,
  69                                             FileChangeReason Reason,
  70                                             SrcMgr::CharacteristicKind FileType,
  71                                             FileID PrevFID) {
  72   if (Reason == EnterFile)
  73     Files.emplace_back();
  74   else if (Reason == ExitFile)
  75     Files.pop_back();
  76 }
  77
  78 void DuplicateIncludeCallbacks::InclusionDirective(
  79     SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
  80     bool IsAngled, CharSourceRange FilenameRange, Optional<FileEntryRef> File,
  81     StringRef SearchPath, StringRef RelativePath, const Module *Imported,
  82     SrcMgr::CharacteristicKind FileType) {
  83   if (llvm::is_contained(Files.back(), FileName)) {
  84     // We want to delete the entire line, so make sure that [Start,End] covers
  85     // everything.
  86     SourceLocation Start =
  87         advanceBeyondCurrentLine(SM, HashLoc, -1).getLocWithOffset(-1);
  88     SourceLocation End =
  89         advanceBeyondCurrentLine(SM, FilenameRange.getEnd(), 1);
  90     Check.diag(HashLoc, "duplicate include")
  91         << FixItHint::CreateRemoval(SourceRange{Start, End});
  92   } else
  93     Files.back().push_back(FileName);
  94 }
  95
  96 void DuplicateIncludeCallbacks::MacroDefined(const Token &MacroNameTok,
  97                                              const MacroDirective *MD) {
  98   Files.back().clear();
  99 }
 100
 101 void DuplicateIncludeCallbacks::MacroUndefined(const Token &MacroNameTok,
 102                                                const MacroDefinition &MD,
 103                                                const MacroDirective *Undef) {
 104   Files.back().clear();
 105 }
 106
 107 } // namespace
 108
 109 void DuplicateIncludeCheck::registerPPCallbacks(
 110     const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) {
 111   PP->addPPCallbacks(std::make_unique<DuplicateIncludeCallbacks>(*this, SM));
 112 }
 113
 114 } // namespace readability
 115 } // namespace tidy
 116 } // namespace clang