clang  9.0.0svn
DependencyFile.cpp
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1 //===--- DependencyFile.cpp - Generate dependency file --------------------===//
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 // This code generates dependency files.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Frontend/Utils.h"
20 #include "clang/Lex/ModuleMap.h"
21 #include "clang/Lex/PPCallbacks.h"
22 #include "clang/Lex/Preprocessor.h"
24 #include "llvm/ADT/StringSet.h"
25 #include "llvm/ADT/StringSwitch.h"
26 #include "llvm/Support/FileSystem.h"
27 #include "llvm/Support/Path.h"
28 #include "llvm/Support/raw_ostream.h"
29 
30 using namespace clang;
31 
32 namespace {
33 struct DepCollectorPPCallbacks : public PPCallbacks {
34  DependencyCollector &DepCollector;
36  DepCollectorPPCallbacks(DependencyCollector &L, SourceManager &SM)
37  : DepCollector(L), SM(SM) { }
38 
39  void FileChanged(SourceLocation Loc, FileChangeReason Reason,
41  FileID PrevFID) override {
42  if (Reason != PPCallbacks::EnterFile)
43  return;
44 
45  // Dependency generation really does want to go all the way to the
46  // file entry for a source location to find out what is depended on.
47  // We do not want #line markers to affect dependency generation!
48  const FileEntry *FE =
50  if (!FE)
51  return;
52 
53  StringRef Filename =
54  llvm::sys::path::remove_leading_dotslash(FE->getName());
55 
56  DepCollector.maybeAddDependency(Filename, /*FromModule*/false,
57  isSystem(FileType),
58  /*IsModuleFile*/false, /*IsMissing*/false);
59  }
60 
61  void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
62  StringRef FileName, bool IsAngled,
63  CharSourceRange FilenameRange, const FileEntry *File,
64  StringRef SearchPath, StringRef RelativePath,
65  const Module *Imported,
66  SrcMgr::CharacteristicKind FileType) override {
67  if (!File)
68  DepCollector.maybeAddDependency(FileName, /*FromModule*/false,
69  /*IsSystem*/false, /*IsModuleFile*/false,
70  /*IsMissing*/true);
71  // Files that actually exist are handled by FileChanged.
72  }
73 
74  void EndOfMainFile() override {
75  DepCollector.finishedMainFile();
76  }
77 };
78 
79 struct DepCollectorMMCallbacks : public ModuleMapCallbacks {
80  DependencyCollector &DepCollector;
81  DepCollectorMMCallbacks(DependencyCollector &DC) : DepCollector(DC) {}
82 
83  void moduleMapFileRead(SourceLocation Loc, const FileEntry &Entry,
84  bool IsSystem) override {
85  StringRef Filename = Entry.getName();
86  DepCollector.maybeAddDependency(Filename, /*FromModule*/false,
87  /*IsSystem*/IsSystem,
88  /*IsModuleFile*/false,
89  /*IsMissing*/false);
90  }
91 };
92 
93 struct DepCollectorASTListener : public ASTReaderListener {
94  DependencyCollector &DepCollector;
95  DepCollectorASTListener(DependencyCollector &L) : DepCollector(L) { }
96  bool needsInputFileVisitation() override { return true; }
97  bool needsSystemInputFileVisitation() override {
98  return DepCollector.needSystemDependencies();
99  }
100  void visitModuleFile(StringRef Filename,
101  serialization::ModuleKind Kind) override {
102  DepCollector.maybeAddDependency(Filename, /*FromModule*/true,
103  /*IsSystem*/false, /*IsModuleFile*/true,
104  /*IsMissing*/false);
105  }
106  bool visitInputFile(StringRef Filename, bool IsSystem,
107  bool IsOverridden, bool IsExplicitModule) override {
108  if (IsOverridden || IsExplicitModule)
109  return true;
110 
111  DepCollector.maybeAddDependency(Filename, /*FromModule*/true, IsSystem,
112  /*IsModuleFile*/false, /*IsMissing*/false);
113  return true;
114  }
115 };
116 } // end anonymous namespace
117 
118 void DependencyCollector::maybeAddDependency(StringRef Filename, bool FromModule,
119  bool IsSystem, bool IsModuleFile,
120  bool IsMissing) {
121  if (Seen.insert(Filename).second &&
122  sawDependency(Filename, FromModule, IsSystem, IsModuleFile, IsMissing))
123  Dependencies.push_back(Filename);
124 }
125 
126 static bool isSpecialFilename(StringRef Filename) {
127  return llvm::StringSwitch<bool>(Filename)
128  .Case("<built-in>", true)
129  .Case("<stdin>", true)
130  .Default(false);
131 }
132 
133 bool DependencyCollector::sawDependency(StringRef Filename, bool FromModule,
134  bool IsSystem, bool IsModuleFile,
135  bool IsMissing) {
136  return !isSpecialFilename(Filename) &&
137  (needSystemDependencies() || !IsSystem);
138 }
139 
142  PP.addPPCallbacks(
143  llvm::make_unique<DepCollectorPPCallbacks>(*this, PP.getSourceManager()));
145  llvm::make_unique<DepCollectorMMCallbacks>(*this));
146 }
148  R.addListener(llvm::make_unique<DepCollectorASTListener>(*this));
149 }
150 
151 namespace {
152 /// Private implementation for DependencyFileGenerator
153 class DFGImpl : public PPCallbacks {
154  std::vector<std::string> Files;
155  llvm::StringSet<> FilesSet;
156  const Preprocessor *PP;
157  std::string OutputFile;
158  std::vector<std::string> Targets;
159  bool IncludeSystemHeaders;
160  bool PhonyTarget;
161  bool AddMissingHeaderDeps;
162  bool SeenMissingHeader;
163  bool IncludeModuleFiles;
164  DependencyOutputFormat OutputFormat;
165  unsigned InputFileIndex;
166 
167 private:
168  bool FileMatchesDepCriteria(const char *Filename,
169  SrcMgr::CharacteristicKind FileType);
170  void OutputDependencyFile();
171 
172 public:
173  DFGImpl(const Preprocessor *_PP, const DependencyOutputOptions &Opts)
174  : PP(_PP), OutputFile(Opts.OutputFile), Targets(Opts.Targets),
175  IncludeSystemHeaders(Opts.IncludeSystemHeaders),
176  PhonyTarget(Opts.UsePhonyTargets),
177  AddMissingHeaderDeps(Opts.AddMissingHeaderDeps),
178  SeenMissingHeader(false),
179  IncludeModuleFiles(Opts.IncludeModuleFiles),
180  OutputFormat(Opts.OutputFormat),
181  InputFileIndex(0) {
182  for (const auto &ExtraDep : Opts.ExtraDeps) {
183  if (AddFilename(ExtraDep))
184  ++InputFileIndex;
185  }
186  }
187 
188  void FileChanged(SourceLocation Loc, FileChangeReason Reason,
190  FileID PrevFID) override;
191 
192  void FileSkipped(const FileEntry &SkippedFile, const Token &FilenameTok,
193  SrcMgr::CharacteristicKind FileType) override;
194 
195  void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
196  StringRef FileName, bool IsAngled,
197  CharSourceRange FilenameRange, const FileEntry *File,
198  StringRef SearchPath, StringRef RelativePath,
199  const Module *Imported,
200  SrcMgr::CharacteristicKind FileType) override;
201 
202  void HasInclude(SourceLocation Loc, StringRef SpelledFilename, bool IsAngled,
203  const FileEntry *File,
204  SrcMgr::CharacteristicKind FileType) override;
205 
206  void EndOfMainFile() override {
207  OutputDependencyFile();
208  }
209 
210  bool AddFilename(StringRef Filename);
211  bool includeSystemHeaders() const { return IncludeSystemHeaders; }
212  bool includeModuleFiles() const { return IncludeModuleFiles; }
213 };
214 
215 class DFGMMCallback : public ModuleMapCallbacks {
216  DFGImpl &Parent;
217 public:
218  DFGMMCallback(DFGImpl &Parent) : Parent(Parent) {}
219  void moduleMapFileRead(SourceLocation Loc, const FileEntry &Entry,
220  bool IsSystem) override {
221  if (!IsSystem || Parent.includeSystemHeaders())
222  Parent.AddFilename(Entry.getName());
223  }
224 };
225 
226 class DFGASTReaderListener : public ASTReaderListener {
227  DFGImpl &Parent;
228 public:
229  DFGASTReaderListener(DFGImpl &Parent)
230  : Parent(Parent) { }
231  bool needsInputFileVisitation() override { return true; }
232  bool needsSystemInputFileVisitation() override {
233  return Parent.includeSystemHeaders();
234  }
235  void visitModuleFile(StringRef Filename,
236  serialization::ModuleKind Kind) override;
237  bool visitInputFile(StringRef Filename, bool isSystem,
238  bool isOverridden, bool isExplicitModule) override;
239 };
240 }
241 
242 DependencyFileGenerator::DependencyFileGenerator(void *Impl)
243 : Impl(Impl) { }
244 
247 
248  if (Opts.Targets.empty()) {
249  PP.getDiagnostics().Report(diag::err_fe_dependency_file_requires_MT);
250  return nullptr;
251  }
252 
253  // Disable the "file not found" diagnostic if the -MG option was given.
254  if (Opts.AddMissingHeaderDeps)
256 
257  DFGImpl *Callback = new DFGImpl(&PP, Opts);
258  PP.addPPCallbacks(std::unique_ptr<PPCallbacks>(Callback));
260  llvm::make_unique<DFGMMCallback>(*Callback));
261  return new DependencyFileGenerator(Callback);
262 }
263 
265  DFGImpl *I = reinterpret_cast<DFGImpl *>(Impl);
266  assert(I && "missing implementation");
267  R.addListener(llvm::make_unique<DFGASTReaderListener>(*I));
268 }
269 
270 /// FileMatchesDepCriteria - Determine whether the given Filename should be
271 /// considered as a dependency.
272 bool DFGImpl::FileMatchesDepCriteria(const char *Filename,
273  SrcMgr::CharacteristicKind FileType) {
274  if (isSpecialFilename(Filename))
275  return false;
276 
277  if (IncludeSystemHeaders)
278  return true;
279 
280  return !isSystem(FileType);
281 }
282 
283 void DFGImpl::FileChanged(SourceLocation Loc,
284  FileChangeReason Reason,
286  FileID PrevFID) {
287  if (Reason != PPCallbacks::EnterFile)
288  return;
289 
290  // Dependency generation really does want to go all the way to the
291  // file entry for a source location to find out what is depended on.
292  // We do not want #line markers to affect dependency generation!
293  SourceManager &SM = PP->getSourceManager();
294 
295  const FileEntry *FE =
297  if (!FE) return;
298 
299  StringRef Filename = FE->getName();
300  if (!FileMatchesDepCriteria(Filename.data(), FileType))
301  return;
302 
303  AddFilename(llvm::sys::path::remove_leading_dotslash(Filename));
304 }
305 
306 void DFGImpl::FileSkipped(const FileEntry &SkippedFile,
307  const Token &FilenameTok,
308  SrcMgr::CharacteristicKind FileType) {
309  StringRef Filename = SkippedFile.getName();
310  if (!FileMatchesDepCriteria(Filename.data(), FileType))
311  return;
312 
313  AddFilename(llvm::sys::path::remove_leading_dotslash(Filename));
314 }
315 
316 void DFGImpl::InclusionDirective(SourceLocation HashLoc,
317  const Token &IncludeTok,
318  StringRef FileName,
319  bool IsAngled,
320  CharSourceRange FilenameRange,
321  const FileEntry *File,
322  StringRef SearchPath,
323  StringRef RelativePath,
324  const Module *Imported,
325  SrcMgr::CharacteristicKind FileType) {
326  if (!File) {
327  if (AddMissingHeaderDeps)
328  AddFilename(FileName);
329  else
330  SeenMissingHeader = true;
331  }
332 }
333 
334 void DFGImpl::HasInclude(SourceLocation Loc, StringRef SpelledFilename,
335  bool IsAngled, const FileEntry *File,
336  SrcMgr::CharacteristicKind FileType) {
337  if (!File)
338  return;
339  StringRef Filename = File->getName();
340  if (!FileMatchesDepCriteria(Filename.data(), FileType))
341  return;
342  AddFilename(llvm::sys::path::remove_leading_dotslash(Filename));
343 }
344 
345 bool DFGImpl::AddFilename(StringRef Filename) {
346  if (FilesSet.insert(Filename).second) {
347  Files.push_back(Filename);
348  return true;
349  }
350  return false;
351 }
352 
353 /// Print the filename, with escaping or quoting that accommodates the three
354 /// most likely tools that use dependency files: GNU Make, BSD Make, and
355 /// NMake/Jom.
356 ///
357 /// BSD Make is the simplest case: It does no escaping at all. This means
358 /// characters that are normally delimiters, i.e. space and # (the comment
359 /// character) simply aren't supported in filenames.
360 ///
361 /// GNU Make does allow space and # in filenames, but to avoid being treated
362 /// as a delimiter or comment, these must be escaped with a backslash. Because
363 /// backslash is itself the escape character, if a backslash appears in a
364 /// filename, it should be escaped as well. (As a special case, $ is escaped
365 /// as $$, which is the normal Make way to handle the $ character.)
366 /// For compatibility with BSD Make and historical practice, if GNU Make
367 /// un-escapes characters in a filename but doesn't find a match, it will
368 /// retry with the unmodified original string.
369 ///
370 /// GCC tries to accommodate both Make formats by escaping any space or #
371 /// characters in the original filename, but not escaping backslashes. The
372 /// apparent intent is so that filenames with backslashes will be handled
373 /// correctly by BSD Make, and by GNU Make in its fallback mode of using the
374 /// unmodified original string; filenames with # or space characters aren't
375 /// supported by BSD Make at all, but will be handled correctly by GNU Make
376 /// due to the escaping.
377 ///
378 /// A corner case that GCC gets only partly right is when the original filename
379 /// has a backslash immediately followed by space or #. GNU Make would expect
380 /// this backslash to be escaped; however GCC escapes the original backslash
381 /// only when followed by space, not #. It will therefore take a dependency
382 /// from a directive such as
383 /// #include "a\ b\#c.h"
384 /// and emit it as
385 /// a\\\ b\\#c.h
386 /// which GNU Make will interpret as
387 /// a\ b\
388 /// followed by a comment. Failing to find this file, it will fall back to the
389 /// original string, which probably doesn't exist either; in any case it won't
390 /// find
391 /// a\ b\#c.h
392 /// which is the actual filename specified by the include directive.
393 ///
394 /// Clang does what GCC does, rather than what GNU Make expects.
395 ///
396 /// NMake/Jom has a different set of scary characters, but wraps filespecs in
397 /// double-quotes to avoid misinterpreting them; see
398 /// https://msdn.microsoft.com/en-us/library/dd9y37ha.aspx for NMake info,
399 /// https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx
400 /// for Windows file-naming info.
401 static void PrintFilename(raw_ostream &OS, StringRef Filename,
402  DependencyOutputFormat OutputFormat) {
403  // Convert filename to platform native path
404  llvm::SmallString<256> NativePath;
405  llvm::sys::path::native(Filename.str(), NativePath);
406 
407  if (OutputFormat == DependencyOutputFormat::NMake) {
408  // Add quotes if needed. These are the characters listed as "special" to
409  // NMake, that are legal in a Windows filespec, and that could cause
410  // misinterpretation of the dependency string.
411  if (NativePath.find_first_of(" #${}^!") != StringRef::npos)
412  OS << '\"' << NativePath << '\"';
413  else
414  OS << NativePath;
415  return;
416  }
417  assert(OutputFormat == DependencyOutputFormat::Make);
418  for (unsigned i = 0, e = NativePath.size(); i != e; ++i) {
419  if (NativePath[i] == '#') // Handle '#' the broken gcc way.
420  OS << '\\';
421  else if (NativePath[i] == ' ') { // Handle space correctly.
422  OS << '\\';
423  unsigned j = i;
424  while (j > 0 && NativePath[--j] == '\\')
425  OS << '\\';
426  } else if (NativePath[i] == '$') // $ is escaped by $$.
427  OS << '$';
428  OS << NativePath[i];
429  }
430 }
431 
432 void DFGImpl::OutputDependencyFile() {
433  if (SeenMissingHeader) {
434  llvm::sys::fs::remove(OutputFile);
435  return;
436  }
437 
438  std::error_code EC;
439  llvm::raw_fd_ostream OS(OutputFile, EC, llvm::sys::fs::F_Text);
440  if (EC) {
441  PP->getDiagnostics().Report(diag::err_fe_error_opening) << OutputFile
442  << EC.message();
443  return;
444  }
445 
446  // Write out the dependency targets, trying to avoid overly long
447  // lines when possible. We try our best to emit exactly the same
448  // dependency file as GCC (4.2), assuming the included files are the
449  // same.
450  const unsigned MaxColumns = 75;
451  unsigned Columns = 0;
452 
453  for (StringRef Target : Targets) {
454  unsigned N = Target.size();
455  if (Columns == 0) {
456  Columns += N;
457  } else if (Columns + N + 2 > MaxColumns) {
458  Columns = N + 2;
459  OS << " \\\n ";
460  } else {
461  Columns += N + 1;
462  OS << ' ';
463  }
464  // Targets already quoted as needed.
465  OS << Target;
466  }
467 
468  OS << ':';
469  Columns += 1;
470 
471  // Now add each dependency in the order it was seen, but avoiding
472  // duplicates.
473  for (StringRef File : Files) {
474  // Start a new line if this would exceed the column limit. Make
475  // sure to leave space for a trailing " \" in case we need to
476  // break the line on the next iteration.
477  unsigned N = File.size();
478  if (Columns + (N + 1) + 2 > MaxColumns) {
479  OS << " \\\n ";
480  Columns = 2;
481  }
482  OS << ' ';
483  PrintFilename(OS, File, OutputFormat);
484  Columns += N + 1;
485  }
486  OS << '\n';
487 
488  // Create phony targets if requested.
489  if (PhonyTarget && !Files.empty()) {
490  unsigned Index = 0;
491  for (auto I = Files.begin(), E = Files.end(); I != E; ++I) {
492  if (Index++ == InputFileIndex)
493  continue;
494  OS << '\n';
495  PrintFilename(OS, *I, OutputFormat);
496  OS << ":\n";
497  }
498  }
499 }
500 
501 bool DFGASTReaderListener::visitInputFile(llvm::StringRef Filename,
502  bool IsSystem, bool IsOverridden,
503  bool IsExplicitModule) {
504  assert(!IsSystem || needsSystemInputFileVisitation());
505  if (IsOverridden || IsExplicitModule)
506  return true;
507 
508  Parent.AddFilename(Filename);
509  return true;
510 }
511 
512 void DFGASTReaderListener::visitModuleFile(llvm::StringRef Filename,
514  if (Parent.includeModuleFiles())
515  Parent.AddFilename(Filename);
516 }
Defines the clang::FileManager interface and associated types.
An interface for collecting the dependencies of a compilation.
Definition: Utils.h:83
Defines the SourceManager interface.
unsigned IncludeModuleFiles
Include module file dependencies.
DiagnosticBuilder Report(SourceLocation Loc, unsigned DiagID)
Issue the message to the client.
Definition: Diagnostic.h:1295
CharacteristicKind
Indicates whether a file or directory holds normal user code, system code, or system code which is im...
Definition: SourceManager.h:78
ModuleMap & getModuleMap()
Retrieve the module map.
Definition: HeaderSearch.h:655
This interface provides a way to observe the actions of the preprocessor as it does its thing...
Definition: PPCallbacks.h:36
unsigned IncludeSystemHeaders
Include system header dependencies.
virtual bool needSystemDependencies()
Return true if system files should be passed to sawDependency().
Definition: Utils.h:102
Token - This structure provides full information about a lexed token.
Definition: Token.h:35
Describes a module or submodule.
Definition: Module.h:65
void SetSuppressIncludeNotFoundError(bool Suppress)
Definition: Preprocessor.h:860
virtual void attachToASTReader(ASTReader &R)
HeaderSearch & getHeaderSearchInfo() const
Definition: Preprocessor.h:821
SourceLocation getExpansionLoc(SourceLocation Loc) const
Given a SourceLocation object Loc, return the expansion location referenced by the ID...
void addModuleMapCallbacks(std::unique_ptr< ModuleMapCallbacks > Callback)
Add a module map callback.
Definition: ModuleMap.h:414
Builds a depdenency file when attached to a Preprocessor (for includes) and ASTReader (for module imp...
Definition: Utils.h:119
NodeId Parent
Definition: ASTDiff.cpp:192
static DependencyFileGenerator * CreateAndAttachToPreprocessor(Preprocessor &PP, const DependencyOutputOptions &Opts)
ModuleKind
Specifies the kind of module that has been loaded.
Definition: Module.h:43
StringRef Filename
Definition: Format.cpp:1629
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...
static bool isSpecialFilename(StringRef Filename)
Represents a character-granular source range.
const FileEntry * getFileEntryForID(FileID FID) const
Returns the FileEntry record for the provided FileID.
virtual void finishedMainFile()
Called when the end of the main file is reached.
Definition: Utils.h:99
Defines the clang::Preprocessor interface.
A mechanism to observe the actions of the module map parser as it reads module map files...
Definition: ModuleMap.h:47
Record the location of an inclusion directive, such as an #include or #import statement.
const SourceManager & SM
Definition: Format.cpp:1490
SourceManager & getSourceManager() const
Definition: Preprocessor.h:819
Kind
void addListener(std::unique_ptr< ASTReaderListener > L)
Add an AST callback listener.
Definition: ASTReader.h:1582
void AttachToASTReader(ASTReader &R)
Encodes a location in the source.
StringRef getName() const
Definition: FileManager.h:86
Cached information about one file (either on disk or in the virtual file system). ...
Definition: FileManager.h:60
DependencyOutputOptions - Options for controlling the compiler dependency file generation.
std::vector< std::string > ExtraDeps
A list of filenames to be used as extra dependencies for every target.
std::string OutputFile
The file to write dependency output to.
An opaque identifier used by SourceManager which refers to a source file (MemoryBuffer) along with it...
DependencyOutputFormat OutputFormat
The format for the dependency file.
Dataflow Directional Tag Classes.
Reads an AST files chain containing the contents of a translation unit.
Definition: ASTReader.h:355
unsigned UsePhonyTargets
Include phony targets for each dependency, which can avoid some &#39;make&#39; problems.
FileID getFileID(SourceLocation SpellingLoc) const
Return the FileID for a SourceLocation.
Abstract interface for callback invocations by the ASTReader.
Definition: ASTReader.h:127
virtual void attachToPreprocessor(Preprocessor &PP)
Defines the PPCallbacks interface.
DiagnosticsEngine & getDiagnostics() const
Definition: Preprocessor.h:812
std::vector< std::string > Targets
A list of names to use as the targets in the dependency file; this list must contain at least one ent...
unsigned AddMissingHeaderDeps
Add missing headers to dependency list.
virtual bool sawDependency(StringRef Filename, bool FromModule, bool IsSystem, bool IsModuleFile, bool IsMissing)
Called when a new file is seen.
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...
DependencyOutputFormat
DependencyOutputFormat - Format for the compiler dependency file.
bool isSystem(CharacteristicKind CK)
Determine whether a file / directory characteristic is for system code.
Definition: SourceManager.h:83
void addPPCallbacks(std::unique_ptr< PPCallbacks > C)
Definition: Preprocessor.h:908
This class handles loading and caching of source files into memory.
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:125