clang  13.0.0git
DependencyFile.cpp
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1 //===--- DependencyFile.cpp - Generate dependency file --------------------===//
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 // This code generates dependency files.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "clang/Frontend/Utils.h"
19 #include "clang/Lex/ModuleMap.h"
20 #include "clang/Lex/PPCallbacks.h"
21 #include "clang/Lex/Preprocessor.h"
23 #include "llvm/ADT/StringSet.h"
24 #include "llvm/ADT/StringSwitch.h"
25 #include "llvm/Support/FileSystem.h"
26 #include "llvm/Support/Path.h"
27 #include "llvm/Support/raw_ostream.h"
28 
29 using namespace clang;
30 
31 namespace {
32 struct DepCollectorPPCallbacks : public PPCallbacks {
33  DependencyCollector &DepCollector;
35  DiagnosticsEngine &Diags;
36  DepCollectorPPCallbacks(DependencyCollector &L, SourceManager &SM,
37  DiagnosticsEngine &Diags)
38  : DepCollector(L), SM(SM), Diags(Diags) {}
39 
40  void FileChanged(SourceLocation Loc, FileChangeReason Reason,
42  FileID PrevFID) override {
43  if (Reason != PPCallbacks::EnterFile)
44  return;
45 
46  // Dependency generation really does want to go all the way to the
47  // file entry for a source location to find out what is depended on.
48  // We do not want #line markers to affect dependency generation!
49  if (Optional<StringRef> Filename = SM.getNonBuiltinFilenameForID(
50  SM.getFileID(SM.getExpansionLoc(Loc))))
51  DepCollector.maybeAddDependency(
52  llvm::sys::path::remove_leading_dotslash(*Filename),
53  /*FromModule*/ false, isSystem(FileType), /*IsModuleFile*/ false,
54  /*IsMissing*/ false);
55  }
56 
57  void FileSkipped(const FileEntryRef &SkippedFile, const Token &FilenameTok,
58  SrcMgr::CharacteristicKind FileType) override {
59  StringRef Filename =
60  llvm::sys::path::remove_leading_dotslash(SkippedFile.getName());
61  DepCollector.maybeAddDependency(Filename, /*FromModule=*/false,
62  /*IsSystem=*/isSystem(FileType),
63  /*IsModuleFile=*/false,
64  /*IsMissing=*/false);
65  }
66 
67  void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
68  StringRef FileName, bool IsAngled,
69  CharSourceRange FilenameRange, const FileEntry *File,
70  StringRef SearchPath, StringRef RelativePath,
71  const Module *Imported,
72  SrcMgr::CharacteristicKind FileType) override {
73  if (!File)
74  DepCollector.maybeAddDependency(FileName, /*FromModule*/false,
75  /*IsSystem*/false, /*IsModuleFile*/false,
76  /*IsMissing*/true);
77  // Files that actually exist are handled by FileChanged.
78  }
79 
80  void HasInclude(SourceLocation Loc, StringRef SpelledFilename, bool IsAngled,
82  SrcMgr::CharacteristicKind FileType) override {
83  if (!File)
84  return;
85  StringRef Filename =
86  llvm::sys::path::remove_leading_dotslash(File->getName());
87  DepCollector.maybeAddDependency(Filename, /*FromModule=*/false,
88  /*IsSystem=*/isSystem(FileType),
89  /*IsModuleFile=*/false,
90  /*IsMissing=*/false);
91  }
92 
93  void EndOfMainFile() override { DepCollector.finishedMainFile(Diags); }
94 };
95 
96 struct DepCollectorMMCallbacks : public ModuleMapCallbacks {
97  DependencyCollector &DepCollector;
98  DepCollectorMMCallbacks(DependencyCollector &DC) : DepCollector(DC) {}
99 
100  void moduleMapFileRead(SourceLocation Loc, const FileEntry &Entry,
101  bool IsSystem) override {
102  StringRef Filename = Entry.getName();
103  DepCollector.maybeAddDependency(Filename, /*FromModule*/false,
104  /*IsSystem*/IsSystem,
105  /*IsModuleFile*/false,
106  /*IsMissing*/false);
107  }
108 };
109 
110 struct DepCollectorASTListener : public ASTReaderListener {
111  DependencyCollector &DepCollector;
112  DepCollectorASTListener(DependencyCollector &L) : DepCollector(L) { }
113  bool needsInputFileVisitation() override { return true; }
114  bool needsSystemInputFileVisitation() override {
115  return DepCollector.needSystemDependencies();
116  }
117  void visitModuleFile(StringRef Filename,
118  serialization::ModuleKind Kind) override {
119  DepCollector.maybeAddDependency(Filename, /*FromModule*/true,
120  /*IsSystem*/false, /*IsModuleFile*/true,
121  /*IsMissing*/false);
122  }
123  bool visitInputFile(StringRef Filename, bool IsSystem,
124  bool IsOverridden, bool IsExplicitModule) override {
125  if (IsOverridden || IsExplicitModule)
126  return true;
127 
128  DepCollector.maybeAddDependency(Filename, /*FromModule*/true, IsSystem,
129  /*IsModuleFile*/false, /*IsMissing*/false);
130  return true;
131  }
132 };
133 } // end anonymous namespace
134 
136  bool FromModule, bool IsSystem,
137  bool IsModuleFile,
138  bool IsMissing) {
139  if (sawDependency(Filename, FromModule, IsSystem, IsModuleFile, IsMissing))
141 }
142 
144  if (Seen.insert(Filename).second) {
145  Dependencies.push_back(std::string(Filename));
146  return true;
147  }
148  return false;
149 }
150 
151 static bool isSpecialFilename(StringRef Filename) {
152  return llvm::StringSwitch<bool>(Filename)
153  .Case("<built-in>", true)
154  .Case("<stdin>", true)
155  .Default(false);
156 }
157 
158 bool DependencyCollector::sawDependency(StringRef Filename, bool FromModule,
159  bool IsSystem, bool IsModuleFile,
160  bool IsMissing) {
161  return !isSpecialFilename(Filename) &&
162  (needSystemDependencies() || !IsSystem);
163 }
164 
167  PP.addPPCallbacks(std::make_unique<DepCollectorPPCallbacks>(
168  *this, PP.getSourceManager(), PP.getDiagnostics()));
170  std::make_unique<DepCollectorMMCallbacks>(*this));
171 }
173  R.addListener(std::make_unique<DepCollectorASTListener>(*this));
174 }
175 
177  const DependencyOutputOptions &Opts)
178  : OutputFile(Opts.OutputFile), Targets(Opts.Targets),
179  IncludeSystemHeaders(Opts.IncludeSystemHeaders),
180  PhonyTarget(Opts.UsePhonyTargets),
181  AddMissingHeaderDeps(Opts.AddMissingHeaderDeps), SeenMissingHeader(false),
182  IncludeModuleFiles(Opts.IncludeModuleFiles),
183  OutputFormat(Opts.OutputFormat), InputFileIndex(0) {
184  for (const auto &ExtraDep : Opts.ExtraDeps) {
185  if (addDependency(ExtraDep.first))
186  ++InputFileIndex;
187  }
188 }
189 
191  // Disable the "file not found" diagnostic if the -MG option was given.
192  if (AddMissingHeaderDeps)
194 
196 }
197 
198 bool DependencyFileGenerator::sawDependency(StringRef Filename, bool FromModule,
199  bool IsSystem, bool IsModuleFile,
200  bool IsMissing) {
201  if (IsMissing) {
202  // Handle the case of missing file from an inclusion directive.
203  if (AddMissingHeaderDeps)
204  return true;
205  SeenMissingHeader = true;
206  return false;
207  }
208  if (IsModuleFile && !IncludeModuleFiles)
209  return false;
210 
212  return false;
213 
214  if (IncludeSystemHeaders)
215  return true;
216 
217  return !IsSystem;
218 }
219 
221  outputDependencyFile(Diags);
222 }
223 
224 /// Print the filename, with escaping or quoting that accommodates the three
225 /// most likely tools that use dependency files: GNU Make, BSD Make, and
226 /// NMake/Jom.
227 ///
228 /// BSD Make is the simplest case: It does no escaping at all. This means
229 /// characters that are normally delimiters, i.e. space and # (the comment
230 /// character) simply aren't supported in filenames.
231 ///
232 /// GNU Make does allow space and # in filenames, but to avoid being treated
233 /// as a delimiter or comment, these must be escaped with a backslash. Because
234 /// backslash is itself the escape character, if a backslash appears in a
235 /// filename, it should be escaped as well. (As a special case, $ is escaped
236 /// as $$, which is the normal Make way to handle the $ character.)
237 /// For compatibility with BSD Make and historical practice, if GNU Make
238 /// un-escapes characters in a filename but doesn't find a match, it will
239 /// retry with the unmodified original string.
240 ///
241 /// GCC tries to accommodate both Make formats by escaping any space or #
242 /// characters in the original filename, but not escaping backslashes. The
243 /// apparent intent is so that filenames with backslashes will be handled
244 /// correctly by BSD Make, and by GNU Make in its fallback mode of using the
245 /// unmodified original string; filenames with # or space characters aren't
246 /// supported by BSD Make at all, but will be handled correctly by GNU Make
247 /// due to the escaping.
248 ///
249 /// A corner case that GCC gets only partly right is when the original filename
250 /// has a backslash immediately followed by space or #. GNU Make would expect
251 /// this backslash to be escaped; however GCC escapes the original backslash
252 /// only when followed by space, not #. It will therefore take a dependency
253 /// from a directive such as
254 /// #include "a\ b\#c.h"
255 /// and emit it as
256 /// a\\\ b\\#c.h
257 /// which GNU Make will interpret as
258 /// a\ b\
259 /// followed by a comment. Failing to find this file, it will fall back to the
260 /// original string, which probably doesn't exist either; in any case it won't
261 /// find
262 /// a\ b\#c.h
263 /// which is the actual filename specified by the include directive.
264 ///
265 /// Clang does what GCC does, rather than what GNU Make expects.
266 ///
267 /// NMake/Jom has a different set of scary characters, but wraps filespecs in
268 /// double-quotes to avoid misinterpreting them; see
269 /// https://msdn.microsoft.com/en-us/library/dd9y37ha.aspx for NMake info,
270 /// https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx
271 /// for Windows file-naming info.
272 static void PrintFilename(raw_ostream &OS, StringRef Filename,
273  DependencyOutputFormat OutputFormat) {
274  // Convert filename to platform native path
275  llvm::SmallString<256> NativePath;
276  llvm::sys::path::native(Filename.str(), NativePath);
277 
278  if (OutputFormat == DependencyOutputFormat::NMake) {
279  // Add quotes if needed. These are the characters listed as "special" to
280  // NMake, that are legal in a Windows filespec, and that could cause
281  // misinterpretation of the dependency string.
282  if (NativePath.find_first_of(" #${}^!") != StringRef::npos)
283  OS << '\"' << NativePath << '\"';
284  else
285  OS << NativePath;
286  return;
287  }
288  assert(OutputFormat == DependencyOutputFormat::Make);
289  for (unsigned i = 0, e = NativePath.size(); i != e; ++i) {
290  if (NativePath[i] == '#') // Handle '#' the broken gcc way.
291  OS << '\\';
292  else if (NativePath[i] == ' ') { // Handle space correctly.
293  OS << '\\';
294  unsigned j = i;
295  while (j > 0 && NativePath[--j] == '\\')
296  OS << '\\';
297  } else if (NativePath[i] == '$') // $ is escaped by $$.
298  OS << '$';
299  OS << NativePath[i];
300  }
301 }
302 
304  if (SeenMissingHeader) {
305  llvm::sys::fs::remove(OutputFile);
306  return;
307  }
308 
309  std::error_code EC;
310  llvm::raw_fd_ostream OS(OutputFile, EC, llvm::sys::fs::OF_TextWithCRLF);
311  if (EC) {
312  Diags.Report(diag::err_fe_error_opening) << OutputFile << EC.message();
313  return;
314  }
315 
317 }
318 
320  // Write out the dependency targets, trying to avoid overly long
321  // lines when possible. We try our best to emit exactly the same
322  // dependency file as GCC (4.2), assuming the included files are the
323  // same.
324  const unsigned MaxColumns = 75;
325  unsigned Columns = 0;
326 
327  for (StringRef Target : Targets) {
328  unsigned N = Target.size();
329  if (Columns == 0) {
330  Columns += N;
331  } else if (Columns + N + 2 > MaxColumns) {
332  Columns = N + 2;
333  OS << " \\\n ";
334  } else {
335  Columns += N + 1;
336  OS << ' ';
337  }
338  // Targets already quoted as needed.
339  OS << Target;
340  }
341 
342  OS << ':';
343  Columns += 1;
344 
345  // Now add each dependency in the order it was seen, but avoiding
346  // duplicates.
348  for (StringRef File : Files) {
349  // Start a new line if this would exceed the column limit. Make
350  // sure to leave space for a trailing " \" in case we need to
351  // break the line on the next iteration.
352  unsigned N = File.size();
353  if (Columns + (N + 1) + 2 > MaxColumns) {
354  OS << " \\\n ";
355  Columns = 2;
356  }
357  OS << ' ';
358  PrintFilename(OS, File, OutputFormat);
359  Columns += N + 1;
360  }
361  OS << '\n';
362 
363  // Create phony targets if requested.
364  if (PhonyTarget && !Files.empty()) {
365  unsigned Index = 0;
366  for (auto I = Files.begin(), E = Files.end(); I != E; ++I) {
367  if (Index++ == InputFileIndex)
368  continue;
369  OS << '\n';
370  PrintFilename(OS, *I, OutputFormat);
371  OS << ":\n";
372  }
373  }
374 }
clang::DependencyOutputOptions
DependencyOutputOptions - Options for controlling the compiler dependency file generation.
Definition: DependencyOutputOptions.h:33
clang::FileEntryRef
A reference to a FileEntry that includes the name of the file as it was accessed by the FileManager's...
Definition: FileEntry.h:60
clang::DeclaratorContext::File
@ File
clang::DependencyFileGenerator::sawDependency
bool sawDependency(StringRef Filename, bool FromModule, bool IsSystem, bool IsModuleFile, bool IsMissing) final override
Called when a new file is seen.
Definition: DependencyFile.cpp:198
string
string(SUBSTRING ${CMAKE_CURRENT_BINARY_DIR} 0 ${PATH_LIB_START} PATH_HEAD) string(SUBSTRING $
Definition: CMakeLists.txt:22
clang::DependencyOutputOptions::ExtraDeps
std::vector< std::pair< std::string, ExtraDepKind > > ExtraDeps
A list of extra dependencies (filename and kind) to be used for every target.
Definition: DependencyOutputOptions.h:68
ModuleMap.h
clang::SourceLocation
Encodes a location in the source.
Definition: SourceLocation.h:89
clang::PPCallbacks
This interface provides a way to observe the actions of the preprocessor as it does its thing.
Definition: PPCallbacks.h:35
clang::MultiVersionKind::Target
@ Target
clang::DependencyFileGenerator::finishedMainFile
void finishedMainFile(DiagnosticsEngine &Diags) override
Called when the end of the main file is reached.
Definition: DependencyFile.cpp:220
Filename
StringRef Filename
Definition: Format.cpp:2176
clang::DiagnosticsEngine
Concrete class used by the front-end to report problems and issues.
Definition: Diagnostic.h:191
clang::PPCallbacks::EnterFile
@ EnterFile
Definition: PPCallbacks.h:40
llvm::Optional
Definition: LLVM.h:40
SourceManager.h
clang::SrcMgr::CharacteristicKind
CharacteristicKind
Indicates whether a file or directory holds normal user code, system code, or system code which is im...
Definition: SourceManager.h:78
DirectoryLookup.h
clang::Token
Token - This structure provides full information about a lexed token.
Definition: Token.h:34
clang::SourceManager
This class handles loading and caching of source files into memory.
Definition: SourceManager.h:624
clang::DependencyCollector::attachToPreprocessor
virtual void attachToPreprocessor(Preprocessor &PP)
Definition: DependencyFile.cpp:166
Preprocessor.h
clang::DependencyCollector::finishedMainFile
virtual void finishedMainFile(DiagnosticsEngine &Diags)
Called when the end of the main file is reached.
Definition: Utils.h:93
isSpecialFilename
static bool isSpecialFilename(StringRef Filename)
Definition: DependencyFile.cpp:151
clang::DependencyOutputFormat::Make
@ Make
clang::ASTReader::addListener
void addListener(std::unique_ptr< ASTReaderListener > L)
Add an AST callback listener.
Definition: ASTReader.h:1607
clang::DependencyOutputFormat
DependencyOutputFormat
DependencyOutputFormat - Format for the compiler dependency file.
Definition: DependencyOutputOptions.h:21
clang::DependencyCollector::~DependencyCollector
virtual ~DependencyCollector()
Definition: DependencyFile.cpp:165
clang::Module
Describes a module or submodule.
Definition: Module.h:96
clang::DependencyFileGenerator::attachToPreprocessor
void attachToPreprocessor(Preprocessor &PP) override
Definition: DependencyFile.cpp:190
Utils.h
clang::DependencyOutputFormat::NMake
@ NMake
DependencyOutputOptions.h
llvm::SmallString
Definition: LLVM.h:37
clang::DependencyCollector::sawDependency
virtual bool sawDependency(StringRef Filename, bool FromModule, bool IsSystem, bool IsModuleFile, bool IsMissing)
Called when a new file is seen.
Definition: DependencyFile.cpp:158
clang::DependencyCollector
An interface for collecting the dependencies of a compilation.
Definition: Utils.h:77
clang::FileEntry
Cached information about one file (either on disk or in the virtual file system).
Definition: FileEntry.h:331
clang::Preprocessor::getSourceManager
SourceManager & getSourceManager() const
Definition: Preprocessor.h:926
clang::FileEntryRef::getName
StringRef getName() const
Definition: FileEntry.h:62
clang::transformer::remove
ASTEdit remove(RangeSelector S)
Removes the source selected by S.
Definition: RewriteRule.cpp:146
clang::InclusionDirective
Record the location of an inclusion directive, such as an #include or #import statement.
Definition: PreprocessingRecord.h:208
clang::ModuleMap::addModuleMapCallbacks
void addModuleMapCallbacks(std::unique_ptr< ModuleMapCallbacks > Callback)
Add a module map callback.
Definition: ModuleMap.h:418
false
#define false
Definition: stdbool.h:17
clang::ModuleMapCallbacks
A mechanism to observe the actions of the module map parser as it reads module map files.
Definition: ModuleMap.h:47
llvm::ArrayRef< std::string >
clang::CharSourceRange
Represents a character-granular source range.
Definition: SourceLocation.h:255
clang::DependencyCollector::needSystemDependencies
virtual bool needSystemDependencies()
Return true if system files should be passed to sawDependency().
Definition: Utils.h:96
clang::ObjCPropertyAttribute::Kind
Kind
Definition: DeclObjCCommon.h:22
clang::ASTReader
Reads an AST files chain containing the contents of a translation unit.
Definition: ASTReader.h:342
clang::DependencyFileGenerator::DependencyFileGenerator
DependencyFileGenerator(const DependencyOutputOptions &Opts)
Definition: DependencyFile.cpp:176
clang::DependencyCollector::attachToASTReader
virtual void attachToASTReader(ASTReader &R)
Definition: DependencyFile.cpp:172
clang
Definition: CalledOnceCheck.h:17
clang::Preprocessor::addPPCallbacks
void addPPCallbacks(std::unique_ptr< PPCallbacks > C)
Definition: Preprocessor.h:1020
PPCallbacks.h
FrontendDiagnostic.h
ASTReader.h
clang::Preprocessor::getDiagnostics
DiagnosticsEngine & getDiagnostics() const
Definition: Preprocessor.h:919
clang::ASTReaderListener
Abstract interface for callback invocations by the ASTReader.
Definition: ASTReader.h:114
clang::Preprocessor::SetSuppressIncludeNotFoundError
void SetSuppressIncludeNotFoundError(bool Suppress)
Definition: Preprocessor.h:972
clang::FileEntry::getName
StringRef getName() const
Definition: FileEntry.h:364
clang::DependencyFileGenerator::outputDependencyFile
void outputDependencyFile(llvm::raw_ostream &OS)
Definition: DependencyFile.cpp:319
clang::FileID
An opaque identifier used by SourceManager which refers to a source file (MemoryBuffer) along with it...
Definition: SourceLocation.h:41
clang::SrcMgr::isSystem
bool isSystem(CharacteristicKind CK)
Determine whether a file / directory characteristic is for system code.
Definition: SourceManager.h:87
clang::serialization::ModuleKind
ModuleKind
Specifies the kind of module that has been loaded.
Definition: ModuleFile.h:41
clang::DependencyCollector::maybeAddDependency
virtual void maybeAddDependency(StringRef Filename, bool FromModule, bool IsSystem, bool IsModuleFile, bool IsMissing)
Add a dependency Filename if it has not been seen before and sawDependency() returns true.
Definition: DependencyFile.cpp:135
FileManager.h
clang::DependencyCollector::getDependencies
ArrayRef< std::string > getDependencies() const
Definition: Utils.h:83
PrintFilename
static void PrintFilename(raw_ostream &OS, StringRef Filename, DependencyOutputFormat OutputFormat)
Print the filename, with escaping or quoting that accommodates the three most likely tools that use d...
Definition: DependencyFile.cpp:272
clang::Preprocessor
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:129
SM
#define SM(sm)
Definition: Cuda.cpp:70
clang::Preprocessor::getHeaderSearchInfo
HeaderSearch & getHeaderSearchInfo() const
Definition: Preprocessor.h:927
clang::DependencyCollector::addDependency
bool addDependency(StringRef Filename)
Return true if the filename was added to the list of dependencies, false otherwise.
Definition: DependencyFile.cpp:143
clang::HeaderSearch::getModuleMap
ModuleMap & getModuleMap()
Retrieve the module map.
Definition: HeaderSearch.h:699
clang::ento::ObjKind::OS
@ OS
Indicates that the tracking object is a descendant of a referenced-counted OSObject,...
clang::DiagnosticsEngine::Report
DiagnosticBuilder Report(SourceLocation Loc, unsigned DiagID)
Issue the message to the client.
Definition: Diagnostic.h:1508