clang-tools  3.8.0
IncludeOrderCheck.cpp
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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 namespace clang {
16 namespace tidy {
17 namespace llvm {
18 
19 namespace {
20 class IncludeOrderPPCallbacks : public PPCallbacks {
21 public:
22  explicit IncludeOrderPPCallbacks(ClangTidyCheck &Check, SourceManager &SM)
23  : LookForMainModule(true), Check(Check), SM(SM) {}
24 
25  void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
26  StringRef FileName, bool IsAngled,
27  CharSourceRange FilenameRange, const FileEntry *File,
28  StringRef SearchPath, StringRef RelativePath,
29  const Module *Imported) override;
30  void EndOfMainFile() override;
31 
32 private:
33  struct IncludeDirective {
34  SourceLocation Loc; ///< '#' location in the include directive
35  CharSourceRange Range; ///< SourceRange for the file name
36  std::string Filename; ///< Filename as a string
37  bool IsAngled; ///< true if this was an include with angle brackets
38  bool IsMainModule; ///< true if this was the first include in a file
39  };
40  std::vector<IncludeDirective> IncludeDirectives;
42 
43  ClangTidyCheck &Check;
44  SourceManager &SM;
45 };
46 } // namespace
47 
48 void IncludeOrderCheck::registerPPCallbacks(CompilerInstance &Compiler) {
49  Compiler.getPreprocessor().addPPCallbacks(
50  ::llvm::make_unique<IncludeOrderPPCallbacks>(
51  *this, Compiler.getSourceManager()));
52 }
53 
54 static int getPriority(StringRef Filename, bool IsAngled, bool IsMainModule) {
55  // We leave the main module header at the top.
56  if (IsMainModule)
57  return 0;
58 
59  // LLVM and clang headers are in the penultimate position.
60  if (Filename.startswith("llvm/") || Filename.startswith("llvm-c/") ||
61  Filename.startswith("clang/") || Filename.startswith("clang-c/"))
62  return 2;
63 
64  // System headers are sorted to the end.
65  if (IsAngled || Filename.startswith("gtest/"))
66  return 3;
67 
68  // Other headers are inserted between the main module header and LLVM headers.
69  return 1;
70 }
71 
72 void IncludeOrderPPCallbacks::InclusionDirective(
73  SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
74  bool IsAngled, CharSourceRange FilenameRange, const FileEntry *File,
75  StringRef SearchPath, StringRef RelativePath, const Module *Imported) {
76  // We recognize the first include as a special main module header and want
77  // to leave it in the top position.
78  IncludeDirective ID = {HashLoc, FilenameRange, FileName, IsAngled, false};
79  if (LookForMainModule && !IsAngled) {
80  ID.IsMainModule = true;
81  LookForMainModule = false;
82  }
83  IncludeDirectives.push_back(std::move(ID));
84 }
85 
86 void IncludeOrderPPCallbacks::EndOfMainFile() {
87  LookForMainModule = true;
88  if (IncludeDirectives.empty())
89  return;
90 
91  // TODO: find duplicated includes.
92 
93  // Form blocks of includes. We don't want to sort across blocks. This also
94  // implicitly makes us never reorder over #defines or #if directives.
95  // FIXME: We should be more careful about sorting below comments as we don't
96  // know if the comment refers to the next include or the whole block that
97  // follows.
98  std::vector<unsigned> Blocks(1, 0);
99  for (unsigned I = 1, E = IncludeDirectives.size(); I != E; ++I)
100  if (SM.getExpansionLineNumber(IncludeDirectives[I].Loc) !=
101  SM.getExpansionLineNumber(IncludeDirectives[I - 1].Loc) + 1)
102  Blocks.push_back(I);
103  Blocks.push_back(IncludeDirectives.size()); // Sentinel value.
104 
105  // Get a vector of indices.
106  std::vector<unsigned> IncludeIndices;
107  for (unsigned I = 0, E = IncludeDirectives.size(); I != E; ++I)
108  IncludeIndices.push_back(I);
109 
110  // Sort the includes. We first sort by priority, then lexicographically.
111  for (unsigned BI = 0, BE = Blocks.size() - 1; BI != BE; ++BI)
112  std::sort(IncludeIndices.begin() + Blocks[BI],
113  IncludeIndices.begin() + Blocks[BI + 1],
114  [this](unsigned LHSI, unsigned RHSI) {
115  IncludeDirective &LHS = IncludeDirectives[LHSI];
116  IncludeDirective &RHS = IncludeDirectives[RHSI];
117 
118  int PriorityLHS =
119  getPriority(LHS.Filename, LHS.IsAngled, LHS.IsMainModule);
120  int PriorityRHS =
121  getPriority(RHS.Filename, RHS.IsAngled, RHS.IsMainModule);
122 
123  return std::tie(PriorityLHS, LHS.Filename) <
124  std::tie(PriorityRHS, RHS.Filename);
125  });
126 
127  // Emit a warning for each block and fixits for all changes within that block.
128  for (unsigned BI = 0, BE = Blocks.size() - 1; BI != BE; ++BI) {
129  // Find the first include that's not in the right position.
130  unsigned I, E;
131  for (I = Blocks[BI], E = Blocks[BI + 1]; I != E; ++I)
132  if (IncludeIndices[I] != I)
133  break;
134 
135  if (I == E)
136  continue;
137 
138  // Emit a warning.
139  auto D = Check.diag(IncludeDirectives[I].Loc,
140  "#includes are not sorted properly");
141 
142  // Emit fix-its for all following includes in this block.
143  for (; I != E; ++I) {
144  if (IncludeIndices[I] == I)
145  continue;
146  const IncludeDirective &CopyFrom = IncludeDirectives[IncludeIndices[I]];
147 
148  SourceLocation FromLoc = CopyFrom.Range.getBegin();
149  const char *FromData = SM.getCharacterData(FromLoc);
150  unsigned FromLen = std::strcspn(FromData, "\n");
151 
152  StringRef FixedName(FromData, FromLen);
153 
154  SourceLocation ToLoc = IncludeDirectives[I].Range.getBegin();
155  const char *ToData = SM.getCharacterData(ToLoc);
156  unsigned ToLen = std::strcspn(ToData, "\n");
157  auto ToRange =
158  CharSourceRange::getCharRange(ToLoc, ToLoc.getLocWithOffset(ToLen));
159 
160  D << FixItHint::CreateReplacement(ToRange, FixedName);
161  }
162  }
163 
164  IncludeDirectives.clear();
165 }
166 
167 } // namespace llvm
168 } // namespace tidy
169 } // namespace clang
SourceLocation Loc
'#' location in the include directive
HeaderHandle File
bool LookForMainModule
void registerPPCallbacks(CompilerInstance &Compiler) override
Override this to register PPCallbacks with Compiler.
SourceManager & SM
std::string Filename
Filename as a string.
bool IsAngled
true if this was an include with angle brackets
std::vector< IncludeDirective > IncludeDirectives
bool IsMainModule
true if this was the first include in a file
ClangTidyCheck & Check
CharSourceRange Range
SourceRange for the file name.
static int getPriority(StringRef Filename, bool IsAngled, bool IsMainModule)