clang  16.0.0git
DependencyFile.cpp
Go to the documentation of this file.
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;
34  Preprocessor &PP;
35  DepCollectorPPCallbacks(DependencyCollector &L, Preprocessor &PP)
36  : DepCollector(L), PP(PP) {}
37 
38  void LexedFileChanged(FileID FID, LexedFileChangeReason Reason,
39  SrcMgr::CharacteristicKind FileType, FileID PrevFID,
40  SourceLocation Loc) override {
42  return;
43 
44  // Dependency generation really does want to go all the way to the
45  // file entry for a source location to find out what is depended on.
46  // We do not want #line markers to affect dependency generation!
49  DepCollector.maybeAddDependency(
50  llvm::sys::path::remove_leading_dotslash(*Filename),
51  /*FromModule*/ false, isSystem(FileType), /*IsModuleFile*/ false,
52  /*IsMissing*/ false);
53  }
54 
55  void FileSkipped(const FileEntryRef &SkippedFile, const Token &FilenameTok,
56  SrcMgr::CharacteristicKind FileType) override {
57  StringRef Filename =
58  llvm::sys::path::remove_leading_dotslash(SkippedFile.getName());
59  DepCollector.maybeAddDependency(Filename, /*FromModule=*/false,
60  /*IsSystem=*/isSystem(FileType),
61  /*IsModuleFile=*/false,
62  /*IsMissing=*/false);
63  }
64 
65  void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
66  StringRef FileName, bool IsAngled,
67  CharSourceRange FilenameRange,
68  Optional<FileEntryRef> File, StringRef SearchPath,
69  StringRef RelativePath, const Module *Imported,
70  SrcMgr::CharacteristicKind FileType) override {
71  if (!File)
72  DepCollector.maybeAddDependency(FileName, /*FromModule*/false,
73  /*IsSystem*/false, /*IsModuleFile*/false,
74  /*IsMissing*/true);
75  // Files that actually exist are handled by FileChanged.
76  }
77 
78  void HasInclude(SourceLocation Loc, StringRef SpelledFilename, bool IsAngled,
80  SrcMgr::CharacteristicKind FileType) override {
81  if (!File)
82  return;
83  StringRef Filename =
84  llvm::sys::path::remove_leading_dotslash(File->getName());
85  DepCollector.maybeAddDependency(Filename, /*FromModule=*/false,
86  /*IsSystem=*/isSystem(FileType),
87  /*IsModuleFile=*/false,
88  /*IsMissing=*/false);
89  }
90 
91  void EndOfMainFile() override {
92  DepCollector.finishedMainFile(PP.getDiagnostics());
93  }
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  StringRef SearchPath;
145 #ifdef _WIN32
146  // Make the search insensitive to case and separators.
148  llvm::sys::path::native(TmpPath);
149  std::transform(TmpPath.begin(), TmpPath.end(), TmpPath.begin(), ::tolower);
150  SearchPath = TmpPath.str();
151 #else
152  SearchPath = Filename;
153 #endif
154 
155  if (Seen.insert(SearchPath).second) {
156  Dependencies.push_back(std::string(Filename));
157  return true;
158  }
159  return false;
160 }
161 
162 static bool isSpecialFilename(StringRef Filename) {
163  return Filename == "<built-in>";
164 }
165 
166 bool DependencyCollector::sawDependency(StringRef Filename, bool FromModule,
167  bool IsSystem, bool IsModuleFile,
168  bool IsMissing) {
169  return !isSpecialFilename(Filename) &&
170  (needSystemDependencies() || !IsSystem);
171 }
172 
175  PP.addPPCallbacks(std::make_unique<DepCollectorPPCallbacks>(*this, PP));
177  std::make_unique<DepCollectorMMCallbacks>(*this));
178 }
180  R.addListener(std::make_unique<DepCollectorASTListener>(*this));
181 }
182 
184  const DependencyOutputOptions &Opts)
185  : OutputFile(Opts.OutputFile), Targets(Opts.Targets),
186  IncludeSystemHeaders(Opts.IncludeSystemHeaders),
187  PhonyTarget(Opts.UsePhonyTargets),
188  AddMissingHeaderDeps(Opts.AddMissingHeaderDeps), SeenMissingHeader(false),
189  IncludeModuleFiles(Opts.IncludeModuleFiles),
190  OutputFormat(Opts.OutputFormat), InputFileIndex(0) {
191  for (const auto &ExtraDep : Opts.ExtraDeps) {
192  if (addDependency(ExtraDep.first))
193  ++InputFileIndex;
194  }
195 }
196 
198  // Disable the "file not found" diagnostic if the -MG option was given.
199  if (AddMissingHeaderDeps)
201 
203 }
204 
205 bool DependencyFileGenerator::sawDependency(StringRef Filename, bool FromModule,
206  bool IsSystem, bool IsModuleFile,
207  bool IsMissing) {
208  if (IsMissing) {
209  // Handle the case of missing file from an inclusion directive.
210  if (AddMissingHeaderDeps)
211  return true;
212  SeenMissingHeader = true;
213  return false;
214  }
215  if (IsModuleFile && !IncludeModuleFiles)
216  return false;
217 
219  return false;
220 
221  if (IncludeSystemHeaders)
222  return true;
223 
224  return !IsSystem;
225 }
226 
228  outputDependencyFile(Diags);
229 }
230 
231 /// Print the filename, with escaping or quoting that accommodates the three
232 /// most likely tools that use dependency files: GNU Make, BSD Make, and
233 /// NMake/Jom.
234 ///
235 /// BSD Make is the simplest case: It does no escaping at all. This means
236 /// characters that are normally delimiters, i.e. space and # (the comment
237 /// character) simply aren't supported in filenames.
238 ///
239 /// GNU Make does allow space and # in filenames, but to avoid being treated
240 /// as a delimiter or comment, these must be escaped with a backslash. Because
241 /// backslash is itself the escape character, if a backslash appears in a
242 /// filename, it should be escaped as well. (As a special case, $ is escaped
243 /// as $$, which is the normal Make way to handle the $ character.)
244 /// For compatibility with BSD Make and historical practice, if GNU Make
245 /// un-escapes characters in a filename but doesn't find a match, it will
246 /// retry with the unmodified original string.
247 ///
248 /// GCC tries to accommodate both Make formats by escaping any space or #
249 /// characters in the original filename, but not escaping backslashes. The
250 /// apparent intent is so that filenames with backslashes will be handled
251 /// correctly by BSD Make, and by GNU Make in its fallback mode of using the
252 /// unmodified original string; filenames with # or space characters aren't
253 /// supported by BSD Make at all, but will be handled correctly by GNU Make
254 /// due to the escaping.
255 ///
256 /// A corner case that GCC gets only partly right is when the original filename
257 /// has a backslash immediately followed by space or #. GNU Make would expect
258 /// this backslash to be escaped; however GCC escapes the original backslash
259 /// only when followed by space, not #. It will therefore take a dependency
260 /// from a directive such as
261 /// #include "a\ b\#c.h"
262 /// and emit it as
263 /// a\\\ b\\#c.h
264 /// which GNU Make will interpret as
265 /// a\ b\
266 /// followed by a comment. Failing to find this file, it will fall back to the
267 /// original string, which probably doesn't exist either; in any case it won't
268 /// find
269 /// a\ b\#c.h
270 /// which is the actual filename specified by the include directive.
271 ///
272 /// Clang does what GCC does, rather than what GNU Make expects.
273 ///
274 /// NMake/Jom has a different set of scary characters, but wraps filespecs in
275 /// double-quotes to avoid misinterpreting them; see
276 /// https://msdn.microsoft.com/en-us/library/dd9y37ha.aspx for NMake info,
277 /// https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx
278 /// for Windows file-naming info.
279 static void PrintFilename(raw_ostream &OS, StringRef Filename,
280  DependencyOutputFormat OutputFormat) {
281  // Convert filename to platform native path
282  llvm::SmallString<256> NativePath;
283  llvm::sys::path::native(Filename.str(), NativePath);
284 
285  if (OutputFormat == DependencyOutputFormat::NMake) {
286  // Add quotes if needed. These are the characters listed as "special" to
287  // NMake, that are legal in a Windows filespec, and that could cause
288  // misinterpretation of the dependency string.
289  if (NativePath.find_first_of(" #${}^!") != StringRef::npos)
290  OS << '\"' << NativePath << '\"';
291  else
292  OS << NativePath;
293  return;
294  }
295  assert(OutputFormat == DependencyOutputFormat::Make);
296  for (unsigned i = 0, e = NativePath.size(); i != e; ++i) {
297  if (NativePath[i] == '#') // Handle '#' the broken gcc way.
298  OS << '\\';
299  else if (NativePath[i] == ' ') { // Handle space correctly.
300  OS << '\\';
301  unsigned j = i;
302  while (j > 0 && NativePath[--j] == '\\')
303  OS << '\\';
304  } else if (NativePath[i] == '$') // $ is escaped by $$.
305  OS << '$';
306  OS << NativePath[i];
307  }
308 }
309 
311  if (SeenMissingHeader) {
312  llvm::sys::fs::remove(OutputFile);
313  return;
314  }
315 
316  std::error_code EC;
317  llvm::raw_fd_ostream OS(OutputFile, EC, llvm::sys::fs::OF_TextWithCRLF);
318  if (EC) {
319  Diags.Report(diag::err_fe_error_opening) << OutputFile << EC.message();
320  return;
321  }
322 
324 }
325 
327  // Write out the dependency targets, trying to avoid overly long
328  // lines when possible. We try our best to emit exactly the same
329  // dependency file as GCC>=10, assuming the included files are the
330  // same.
331  const unsigned MaxColumns = 75;
332  unsigned Columns = 0;
333 
334  for (StringRef Target : Targets) {
335  unsigned N = Target.size();
336  if (Columns == 0) {
337  Columns += N;
338  } else if (Columns + N + 2 > MaxColumns) {
339  Columns = N + 2;
340  OS << " \\\n ";
341  } else {
342  Columns += N + 1;
343  OS << ' ';
344  }
345  // Targets already quoted as needed.
346  OS << Target;
347  }
348 
349  OS << ':';
350  Columns += 1;
351 
352  // Now add each dependency in the order it was seen, but avoiding
353  // duplicates.
355  for (StringRef File : Files) {
356  if (File == "<stdin>")
357  continue;
358  // Start a new line if this would exceed the column limit. Make
359  // sure to leave space for a trailing " \" in case we need to
360  // break the line on the next iteration.
361  unsigned N = File.size();
362  if (Columns + (N + 1) + 2 > MaxColumns) {
363  OS << " \\\n ";
364  Columns = 2;
365  }
366  OS << ' ';
367  PrintFilename(OS, File, OutputFormat);
368  Columns += N + 1;
369  }
370  OS << '\n';
371 
372  // Create phony targets if requested.
373  if (PhonyTarget && !Files.empty()) {
374  unsigned Index = 0;
375  for (auto I = Files.begin(), E = Files.end(); I != E; ++I) {
376  if (Index++ == InputFileIndex)
377  continue;
378  PrintFilename(OS, *I, OutputFormat);
379  OS << ":\n";
380  }
381  }
382 }
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:62
clang::DeclaratorContext::File
@ File
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:86
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:227
Filename
StringRef Filename
Definition: Format.cpp:2715
clang::DiagnosticsEngine
Concrete class used by the front-end to report problems and issues.
Definition: Diagnostic.h:192
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:79
DirectoryLookup.h
clang::Token
Token - This structure provides full information about a lexed token.
Definition: Token.h:35
clang::DependencyCollector::attachToPreprocessor
virtual void attachToPreprocessor(Preprocessor &PP)
Definition: DependencyFile.cpp:174
Preprocessor.h
clang::DependencyCollector::finishedMainFile
virtual void finishedMainFile(DiagnosticsEngine &Diags)
Called when the end of the main file is reached.
Definition: Utils.h:77
isSpecialFilename
static bool isSpecialFilename(StringRef Filename)
Definition: DependencyFile.cpp:162
clang::DependencyOutputFormat::Make
@ Make
clang::ASTReader::addListener
void addListener(std::unique_ptr< ASTReaderListener > L)
Add an AST callback listener.
Definition: ASTReader.h:1644
clang::DependencyOutputFormat
DependencyOutputFormat
DependencyOutputFormat - Format for the compiler dependency file.
Definition: DependencyOutputOptions.h:21
clang::DependencyCollector::~DependencyCollector
virtual ~DependencyCollector()
Definition: DependencyFile.cpp:173
clang::Module
Describes a module or submodule.
Definition: Module.h:98
clang::DependencyFileGenerator::attachToPreprocessor
void attachToPreprocessor(Preprocessor &PP) override
Definition: DependencyFile.cpp:197
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:166
clang::SourceManager::getNonBuiltinFilenameForID
Optional< StringRef > getNonBuiltinFilenameForID(FileID FID) const
Returns the filename for the provided FileID, unless it's a built-in buffer that's not represented by...
Definition: SourceManager.cpp:734
clang::PPCallbacks::LexedFileChangeReason::EnterFile
@ EnterFile
clang::DependencyCollector
An interface for collecting the dependencies of a compilation.
Definition: Utils.h:61
clang::FileEntry
Cached information about one file (either on disk or in the virtual file system).
Definition: FileEntry.h:366
clang::Preprocessor::getSourceManager
SourceManager & getSourceManager() const
Definition: Preprocessor.h:1065
clang::FileEntryRef::getName
StringRef getName() const
The name of this FileEntry.
Definition: FileEntry.h:66
clang::transformer::remove
ASTEdit remove(RangeSelector S)
Removes the source selected by S.
Definition: RewriteRule.cpp:163
clang::InclusionDirective
Record the location of an inclusion directive, such as an #include or #import statement.
Definition: PreprocessingRecord.h:207
clang::ModuleMap::addModuleMapCallbacks
void addModuleMapCallbacks(std::unique_ptr< ModuleMapCallbacks > Callback)
Add a module map callback.
Definition: ModuleMap.h:423
false
#define false
Definition: stdbool.h:22
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:253
clang::DependencyCollector::needSystemDependencies
virtual bool needSystemDependencies()
Return true if system files should be passed to sawDependency().
Definition: Utils.h:80
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:359
clang::DependencyFileGenerator::DependencyFileGenerator
DependencyFileGenerator(const DependencyOutputOptions &Opts)
Definition: DependencyFile.cpp:183
clang::DependencyCollector::attachToASTReader
virtual void attachToASTReader(ASTReader &R)
Definition: DependencyFile.cpp:179
clang
Definition: CalledOnceCheck.h:17
clang::Preprocessor::addPPCallbacks
void addPPCallbacks(std::unique_ptr< PPCallbacks > C)
Definition: Preprocessor.h:1159
PPCallbacks.h
FrontendDiagnostic.h
ASTReader.h
clang::Preprocessor::getDiagnostics
DiagnosticsEngine & getDiagnostics() const
Definition: Preprocessor.h:1058
clang::ASTReaderListener
Abstract interface for callback invocations by the ASTReader.
Definition: ASTReader.h:113
clang::Preprocessor::SetSuppressIncludeNotFoundError
void SetSuppressIncludeNotFoundError(bool Suppress)
Definition: Preprocessor.h:1111
clang::FileEntry::getName
StringRef getName() const
Definition: FileEntry.h:397
clang::DependencyFileGenerator::outputDependencyFile
void outputDependencyFile(llvm::raw_ostream &OS)
Definition: DependencyFile.cpp:326
clang::FileID
An opaque identifier used by SourceManager which refers to a source file (MemoryBuffer) along with it...
Definition: SourceLocation.h:38
clang::SrcMgr::isSystem
bool isSystem(CharacteristicKind CK)
Determine whether a file / directory characteristic is for system code.
Definition: SourceManager.h:88
clang::serialization::ModuleKind
ModuleKind
Specifies the kind of module that has been loaded.
Definition: ModuleFile.h:42
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:67
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:279
clang::DependencyFileGenerator::sawDependency
bool sawDependency(StringRef Filename, bool FromModule, bool IsSystem, bool IsModuleFile, bool IsMissing) final
Called when a new file is seen.
Definition: DependencyFile.cpp:205
clang::Preprocessor
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:129
clang::Preprocessor::getHeaderSearchInfo
HeaderSearch & getHeaderSearchInfo() const
Definition: Preprocessor.h:1066
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:791
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:1537