clang-tools  9.0.0
Headers.cpp
Go to the documentation of this file.
1 //===--- Headers.cpp - Include headers ---------------------------*- C++-*-===//
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 "Headers.h"
10 #include "Compiler.h"
11 #include "Logger.h"
12 #include "SourceCode.h"
13 #include "clang/Frontend/CompilerInstance.h"
14 #include "clang/Frontend/CompilerInvocation.h"
15 #include "clang/Frontend/FrontendActions.h"
16 #include "clang/Lex/HeaderSearch.h"
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/Support/Path.h"
19 
20 namespace clang {
21 namespace clangd {
22 namespace {
23 
24 class RecordHeaders : public PPCallbacks {
25 public:
26  RecordHeaders(const SourceManager &SM, IncludeStructure *Out)
27  : SM(SM), Out(Out) {}
28 
29  // Record existing #includes - both written and resolved paths. Only #includes
30  // in the main file are collected.
31  void InclusionDirective(SourceLocation HashLoc, const Token & /*IncludeTok*/,
32  llvm::StringRef FileName, bool IsAngled,
33  CharSourceRange FilenameRange, const FileEntry *File,
34  llvm::StringRef /*SearchPath*/,
35  llvm::StringRef /*RelativePath*/,
36  const Module * /*Imported*/,
37  SrcMgr::CharacteristicKind FileKind) override {
38  if (isInsideMainFile(HashLoc, SM)) {
39  Out->MainFileIncludes.emplace_back();
40  auto &Inc = Out->MainFileIncludes.back();
41  Inc.R = halfOpenToRange(SM, FilenameRange);
42  Inc.Written =
43  (IsAngled ? "<" + FileName + ">" : "\"" + FileName + "\"").str();
44  Inc.Resolved = File ? File->tryGetRealPathName() : "";
45  Inc.HashOffset = SM.getFileOffset(HashLoc);
46  Inc.FileKind = FileKind;
47  }
48  if (File) {
49  auto *IncludingFileEntry = SM.getFileEntryForID(SM.getFileID(HashLoc));
50  if (!IncludingFileEntry) {
51  assert(SM.getBufferName(HashLoc).startswith("<") &&
52  "Expected #include location to be a file or <built-in>");
53  // Treat as if included from the main file.
54  IncludingFileEntry = SM.getFileEntryForID(SM.getMainFileID());
55  }
56  Out->recordInclude(IncludingFileEntry->getName(), File->getName(),
57  File->tryGetRealPathName());
58  }
59  }
60 
61 private:
62  const SourceManager &SM;
63  IncludeStructure *Out;
64 };
65 
66 } // namespace
67 
68 bool isLiteralInclude(llvm::StringRef Include) {
69  return Include.startswith("<") || Include.startswith("\"");
70 }
71 
72 bool HeaderFile::valid() const {
73  return (Verbatim && isLiteralInclude(File)) ||
74  (!Verbatim && llvm::sys::path::is_absolute(File));
75 }
76 
77 llvm::Expected<HeaderFile> toHeaderFile(llvm::StringRef Header,
78  llvm::StringRef HintPath) {
79  if (isLiteralInclude(Header))
80  return HeaderFile{Header.str(), /*Verbatim=*/true};
81  auto U = URI::parse(Header);
82  if (!U)
83  return U.takeError();
84 
85  auto IncludePath = URI::includeSpelling(*U);
86  if (!IncludePath)
87  return IncludePath.takeError();
88  if (!IncludePath->empty())
89  return HeaderFile{std::move(*IncludePath), /*Verbatim=*/true};
90 
91  auto Resolved = URI::resolve(*U, HintPath);
92  if (!Resolved)
93  return Resolved.takeError();
94  return HeaderFile{std::move(*Resolved), /*Verbatim=*/false};
95 }
96 
97 llvm::SmallVector<llvm::StringRef, 1> getRankedIncludes(const Symbol &Sym) {
98  auto Includes = Sym.IncludeHeaders;
99  // Sort in descending order by reference count and header length.
100  llvm::sort(Includes, [](const Symbol::IncludeHeaderWithReferences &LHS,
102  if (LHS.References == RHS.References)
103  return LHS.IncludeHeader.size() < RHS.IncludeHeader.size();
104  return LHS.References > RHS.References;
105  });
106  llvm::SmallVector<llvm::StringRef, 1> Headers;
107  for (const auto &Include : Includes)
108  Headers.push_back(Include.IncludeHeader);
109  return Headers;
110 }
111 
112 std::unique_ptr<PPCallbacks>
113 collectIncludeStructureCallback(const SourceManager &SM,
114  IncludeStructure *Out) {
115  return llvm::make_unique<RecordHeaders>(SM, Out);
116 }
117 
118 void IncludeStructure::recordInclude(llvm::StringRef IncludingName,
119  llvm::StringRef IncludedName,
120  llvm::StringRef IncludedRealName) {
121  auto Child = fileIndex(IncludedName);
122  if (!IncludedRealName.empty() && RealPathNames[Child].empty())
123  RealPathNames[Child] = IncludedRealName;
124  auto Parent = fileIndex(IncludingName);
125  IncludeChildren[Parent].push_back(Child);
126 }
127 
128 unsigned IncludeStructure::fileIndex(llvm::StringRef Name) {
129  auto R = NameToIndex.try_emplace(Name, RealPathNames.size());
130  if (R.second)
131  RealPathNames.emplace_back();
132  return R.first->getValue();
133 }
134 
135 llvm::StringMap<unsigned>
136 IncludeStructure::includeDepth(llvm::StringRef Root) const {
137  // Include depth 0 is the main file only.
138  llvm::StringMap<unsigned> Result;
139  Result[Root] = 0;
140  std::vector<unsigned> CurrentLevel;
141  llvm::DenseSet<unsigned> Seen;
142  auto It = NameToIndex.find(Root);
143  if (It != NameToIndex.end()) {
144  CurrentLevel.push_back(It->second);
145  Seen.insert(It->second);
146  }
147 
148  // Each round of BFS traversal finds the next depth level.
149  std::vector<unsigned> PreviousLevel;
150  for (unsigned Level = 1; !CurrentLevel.empty(); ++Level) {
151  PreviousLevel.clear();
152  PreviousLevel.swap(CurrentLevel);
153  for (const auto &Parent : PreviousLevel) {
154  for (const auto &Child : IncludeChildren.lookup(Parent)) {
155  if (Seen.insert(Child).second) {
156  CurrentLevel.push_back(Child);
157  const auto &Name = RealPathNames[Child];
158  // Can't include files if we don't have their real path.
159  if (!Name.empty())
160  Result[Name] = Level;
161  }
162  }
163  }
164  }
165  return Result;
166 }
167 
169  IncludedHeaders.insert(Inc.Written);
170  if (!Inc.Resolved.empty())
171  IncludedHeaders.insert(Inc.Resolved);
172 }
173 
174 /// FIXME(ioeric): we might not want to insert an absolute include path if the
175 /// path is not shortened.
177  PathRef DeclaringHeader, const HeaderFile &InsertedHeader) const {
178  assert(InsertedHeader.valid());
179  if (!HeaderSearchInfo && !InsertedHeader.Verbatim)
180  return false;
181  if (FileName == DeclaringHeader || FileName == InsertedHeader.File)
182  return false;
183  auto Included = [&](llvm::StringRef Header) {
184  return IncludedHeaders.find(Header) != IncludedHeaders.end();
185  };
186  return !Included(DeclaringHeader) && !Included(InsertedHeader.File);
187 }
188 
189 llvm::Optional<std::string>
191  llvm::StringRef IncludingFile) const {
192  assert(InsertedHeader.valid());
193  if (InsertedHeader.Verbatim)
194  return InsertedHeader.File;
195  bool IsSystem = false;
196  std::string Suggested;
197  if (HeaderSearchInfo) {
198  Suggested = HeaderSearchInfo->suggestPathToFileForDiagnostics(
199  InsertedHeader.File, BuildDir, IncludingFile, &IsSystem);
200  } else {
201  // Calculate include relative to including file only.
202  StringRef IncludingDir = llvm::sys::path::parent_path(IncludingFile);
203  SmallString<256> RelFile(InsertedHeader.File);
204  // Replacing with "" leaves "/RelFile" if IncludingDir doesn't end in "/".
205  llvm::sys::path::replace_path_prefix(RelFile, IncludingDir, "./");
206  Suggested = llvm::sys::path::convert_to_slash(
207  llvm::sys::path::remove_leading_dotslash(RelFile));
208  }
209  // FIXME: should we allow (some limited number of) "../header.h"?
210  if (llvm::sys::path::is_absolute(Suggested))
211  return None;
212  if (IsSystem)
213  Suggested = "<" + Suggested + ">";
214  else
215  Suggested = "\"" + Suggested + "\"";
216  return Suggested;
217 }
218 
219 llvm::Optional<TextEdit>
220 IncludeInserter::insert(llvm::StringRef VerbatimHeader) const {
221  llvm::Optional<TextEdit> Edit = None;
222  if (auto Insertion = Inserter.insert(VerbatimHeader.trim("\"<>"),
223  VerbatimHeader.startswith("<")))
224  Edit = replacementToEdit(Code, *Insertion);
225  return Edit;
226 }
227 
228 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const Inclusion &Inc) {
229  return OS << Inc.Written << " = "
230  << (Inc.Resolved.empty() ? Inc.Resolved : "[unresolved]") << " at "
231  << Inc.R;
232 }
233 
234 } // namespace clangd
235 } // namespace clang
unsigned References
The number of translation units that reference this symbol and include this header.
Definition: Symbol.h:104
bool Verbatim
If this is true, File is a literal string quoted with <> or "" that can be #included directly; otherw...
Definition: Headers.h:37
bool isInsideMainFile(SourceLocation Loc, const SourceManager &SM)
Returns true iff Loc is inside the main file.
Definition: SourceCode.cpp:372
llvm::StringRef PathRef
A typedef to represent a ref to file path.
Definition: Path.h:23
Documents should not be synced at all.
llvm::Optional< TextEdit > insert(llvm::StringRef VerbatimHeader) const
Calculates an edit that inserts VerbatimHeader into code.
Definition: Headers.cpp:220
std::string Written
Definition: Headers.h:54
llvm::SmallVector< IncludeHeaderWithReferences, 1 > IncludeHeaders
One Symbol can potentially be incuded via different headers.
Definition: Symbol.h:111
void addExisting(const Inclusion &Inc)
Definition: Headers.cpp:168
bool IsAngled
true if this was an include with angle brackets
llvm::Expected< HeaderFile > toHeaderFile(llvm::StringRef Header, llvm::StringRef HintPath)
Creates a HeaderFile from Header which can be either a URI or a literal include.
Definition: Headers.cpp:77
static constexpr llvm::StringLiteral Name
PathRef FileName
void recordInclude(llvm::StringRef IncludingName, llvm::StringRef IncludedName, llvm::StringRef IncludedRealName)
Definition: Headers.cpp:118
llvm::StringRef IncludeHeader
This can be either a URI of the header to be #include&#39;d for this symbol, or a literal header quoted w...
Definition: Symbol.h:101
The class presents a C++ symbol, e.g.
Definition: Symbol.h:36
std::unique_ptr< PPCallbacks > collectIncludeStructureCallback(const SourceManager &SM, IncludeStructure *Out)
Returns a PPCallback that visits all inclusions in the main file.
Definition: Headers.cpp:113
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
TextEdit replacementToEdit(llvm::StringRef Code, const tooling::Replacement &R)
Definition: SourceCode.cpp:443
llvm::StringMap< unsigned > includeDepth(llvm::StringRef Root) const
Definition: Headers.cpp:136
llvm::Optional< std::string > calculateIncludePath(const HeaderFile &InsertedHeader, llvm::StringRef IncludingFile) const
Determines the preferred way to #include a file, taking into account the search path.
Definition: Headers.cpp:190
llvm::SmallVector< llvm::StringRef, 1 > getRankedIncludes(const Symbol &Sym)
Definition: Headers.cpp:97
llvm::Optional< llvm::Expected< tooling::AtomicChanges > > Result
Definition: Rename.cpp:36
static llvm::Expected< std::string > resolve(const URI &U, llvm::StringRef HintPath="")
Resolves the absolute path of U.
Definition: URI.cpp:222
static llvm::Expected< std::string > includeSpelling(const URI &U)
Gets the preferred spelling of this file for #include, if there is one, e.g.
Definition: URI.cpp:250
static llvm::Expected< URI > parse(llvm::StringRef Uri)
Parse a URI string "<scheme>:[//<authority>/]<path>".
Definition: URI.cpp:164
bool shouldInsertInclude(PathRef DeclaringHeader, const HeaderFile &InsertedHeader) const
Checks whether to add an #include of the header into File.
Definition: Headers.cpp:176
llvm::raw_ostream & operator<<(llvm::raw_ostream &OS, const CodeCompletion &C)
Represents a header file to be #include&#39;d.
Definition: Headers.h:33
bool isLiteralInclude(llvm::StringRef Include)
Returns true if Include is literal include like "path" or <path>.
Definition: Headers.cpp:68
Range halfOpenToRange(const SourceManager &SM, CharSourceRange R)
Definition: SourceCode.cpp:418