clang-tools  7.0.0svn
IncludeOrderCheck.cpp
Go to the documentation of this file.
1 //===--- IncludeOrderCheck.cpp - clang-tidy -------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "IncludeOrderCheck.h"
11 #include "clang/Frontend/CompilerInstance.h"
12 #include "clang/Lex/PPCallbacks.h"
13 #include "clang/Lex/Preprocessor.h"
14 
15 #include <map>
16 
17 namespace clang {
18 namespace tidy {
19 namespace llvm {
20 
21 namespace {
22 class IncludeOrderPPCallbacks : public PPCallbacks {
23 public:
24  explicit IncludeOrderPPCallbacks(ClangTidyCheck &Check, SourceManager &SM)
25  : LookForMainModule(true), Check(Check), SM(SM) {}
26 
27  void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
28  StringRef FileName, bool IsAngled,
29  CharSourceRange FilenameRange, const FileEntry *File,
30  StringRef SearchPath, StringRef RelativePath,
31  const Module *Imported) override;
32  void EndOfMainFile() override;
33 
34 private:
35  struct IncludeDirective {
36  SourceLocation Loc; ///< '#' location in the include directive
37  CharSourceRange Range; ///< SourceRange for the file name
38  std::string Filename; ///< Filename as a string
39  bool IsAngled; ///< true if this was an include with angle brackets
40  bool IsMainModule; ///< true if this was the first include in a file
41  };
42 
43  typedef std::vector<IncludeDirective> FileIncludes;
44  std::map<clang::FileID, FileIncludes> IncludeDirectives;
45  bool LookForMainModule;
46 
47  ClangTidyCheck &Check;
48  SourceManager &SM;
49 };
50 } // namespace
51 
52 void IncludeOrderCheck::registerPPCallbacks(CompilerInstance &Compiler) {
53  Compiler.getPreprocessor().addPPCallbacks(
54  ::llvm::make_unique<IncludeOrderPPCallbacks>(
55  *this, Compiler.getSourceManager()));
56 }
57 
58 static int getPriority(StringRef Filename, bool IsAngled, bool IsMainModule) {
59  // We leave the main module header at the top.
60  if (IsMainModule)
61  return 0;
62 
63  // LLVM and clang headers are in the penultimate position.
64  if (Filename.startswith("llvm/") || Filename.startswith("llvm-c/") ||
65  Filename.startswith("clang/") || Filename.startswith("clang-c/"))
66  return 2;
67 
68  // System headers are sorted to the end.
69  if (IsAngled || Filename.startswith("gtest/"))
70  return 3;
71 
72  // Other headers are inserted between the main module header and LLVM headers.
73  return 1;
74 }
75 
76 void IncludeOrderPPCallbacks::InclusionDirective(
77  SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
78  bool IsAngled, CharSourceRange FilenameRange, const FileEntry *File,
79  StringRef SearchPath, StringRef RelativePath, const Module *Imported) {
80  // We recognize the first include as a special main module header and want
81  // to leave it in the top position.
82  IncludeDirective ID = {HashLoc, FilenameRange, FileName, IsAngled, false};
83  if (LookForMainModule && !IsAngled) {
84  ID.IsMainModule = true;
85  LookForMainModule = false;
86  }
87 
88  // Bucket the include directives by the id of the file they were declared in.
89  IncludeDirectives[SM.getFileID(HashLoc)].push_back(std::move(ID));
90 }
91 
92 void IncludeOrderPPCallbacks::EndOfMainFile() {
93  LookForMainModule = true;
94  if (IncludeDirectives.empty())
95  return;
96 
97  // TODO: find duplicated includes.
98 
99  // Form blocks of includes. We don't want to sort across blocks. This also
100  // implicitly makes us never reorder over #defines or #if directives.
101  // FIXME: We should be more careful about sorting below comments as we don't
102  // know if the comment refers to the next include or the whole block that
103  // follows.
104  for (auto &Bucket : IncludeDirectives) {
105  auto &FileDirectives = Bucket.second;
106  std::vector<unsigned> Blocks(1, 0);
107  for (unsigned I = 1, E = FileDirectives.size(); I != E; ++I)
108  if (SM.getExpansionLineNumber(FileDirectives[I].Loc) !=
109  SM.getExpansionLineNumber(FileDirectives[I - 1].Loc) + 1)
110  Blocks.push_back(I);
111  Blocks.push_back(FileDirectives.size()); // Sentinel value.
112 
113  // Get a vector of indices.
114  std::vector<unsigned> IncludeIndices;
115  for (unsigned I = 0, E = FileDirectives.size(); I != E; ++I)
116  IncludeIndices.push_back(I);
117 
118  // Sort the includes. We first sort by priority, then lexicographically.
119  for (unsigned BI = 0, BE = Blocks.size() - 1; BI != BE; ++BI)
120  std::sort(IncludeIndices.begin() + Blocks[BI],
121  IncludeIndices.begin() + Blocks[BI + 1],
122  [&FileDirectives](unsigned LHSI, unsigned RHSI) {
123  IncludeDirective &LHS = FileDirectives[LHSI];
124  IncludeDirective &RHS = FileDirectives[RHSI];
125 
126  int PriorityLHS =
127  getPriority(LHS.Filename, LHS.IsAngled, LHS.IsMainModule);
128  int PriorityRHS =
129  getPriority(RHS.Filename, RHS.IsAngled, RHS.IsMainModule);
130 
131  return std::tie(PriorityLHS, LHS.Filename) <
132  std::tie(PriorityRHS, RHS.Filename);
133  });
134 
135  // Emit a warning for each block and fixits for all changes within that
136  // block.
137  for (unsigned BI = 0, BE = Blocks.size() - 1; BI != BE; ++BI) {
138  // Find the first include that's not in the right position.
139  unsigned I, E;
140  for (I = Blocks[BI], E = Blocks[BI + 1]; I != E; ++I)
141  if (IncludeIndices[I] != I)
142  break;
143 
144  if (I == E)
145  continue;
146 
147  // Emit a warning.
148  auto D = Check.diag(FileDirectives[I].Loc,
149  "#includes are not sorted properly");
150 
151  // Emit fix-its for all following includes in this block.
152  for (; I != E; ++I) {
153  if (IncludeIndices[I] == I)
154  continue;
155  const IncludeDirective &CopyFrom = FileDirectives[IncludeIndices[I]];
156 
157  SourceLocation FromLoc = CopyFrom.Range.getBegin();
158  const char *FromData = SM.getCharacterData(FromLoc);
159  unsigned FromLen = std::strcspn(FromData, "\n");
160 
161  StringRef FixedName(FromData, FromLen);
162 
163  SourceLocation ToLoc = FileDirectives[I].Range.getBegin();
164  const char *ToData = SM.getCharacterData(ToLoc);
165  unsigned ToLen = std::strcspn(ToData, "\n");
166  auto ToRange =
167  CharSourceRange::getCharRange(ToLoc, ToLoc.getLocWithOffset(ToLen));
168 
169  D << FixItHint::CreateReplacement(ToRange, FixedName);
170  }
171  }
172  }
173 
174  IncludeDirectives.clear();
175 }
176 
177 } // namespace llvm
178 } // namespace tidy
179 } // namespace clang
SourceLocation Loc
&#39;#&#39; location in the include directive
HeaderHandle File
void registerPPCallbacks(CompilerInstance &Compiler) override
Override this to register PPCallbacks with Compiler.
std::string Filename
Filename as a string.
bool IsAngled
true if this was an include with angle brackets
bool IsMainModule
true if this was the first include in a file
CharSourceRange Range
SourceRange for the file name.
static int getPriority(StringRef Filename, bool IsAngled, bool IsMainModule)