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"
15 #include "clang/Basic/FileManager.h"
16 #include "clang/Basic/SourceManager.h"
17 #include "clang/Frontend/DependencyOutputOptions.h"
18 #include "clang/Frontend/FrontendDiagnostic.h"
19 #include "clang/Lex/DirectoryLookup.h"
20 #include "clang/Lex/LexDiagnostic.h"
21 #include "clang/Lex/PPCallbacks.h"
22 #include "clang/Lex/Preprocessor.h"
23 #include "clang/Serialization/ASTReader.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;
35 SourceManager &SM;
DepCollectorPPCallbacks__anonc90c6eea0111::DepCollectorPPCallbacks36 DepCollectorPPCallbacks(DependencyCollector &L, SourceManager &SM)
37 : DepCollector(L), SM(SM) { }
38
FileChanged__anonc90c6eea0111::DepCollectorPPCallbacks39 void FileChanged(SourceLocation Loc, FileChangeReason Reason,
40 SrcMgr::CharacteristicKind FileType,
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 =
49 SM.getFileEntryForID(SM.getFileID(SM.getExpansionLoc(Loc)));
50 if (!FE)
51 return;
52
53 StringRef Filename = FE->getName();
54
55 // Remove leading "./" (or ".//" or "././" etc.)
56 while (Filename.size() > 2 && Filename[0] == '.' &&
57 llvm::sys::path::is_separator(Filename[1])) {
58 Filename = Filename.substr(1);
59 while (llvm::sys::path::is_separator(Filename[0]))
60 Filename = Filename.substr(1);
61 }
62
63 DepCollector.maybeAddDependency(Filename, /*FromModule*/false,
64 FileType != SrcMgr::C_User,
65 /*IsModuleFile*/false, /*IsMissing*/false);
66 }
67
InclusionDirective__anonc90c6eea0111::DepCollectorPPCallbacks68 void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
69 StringRef FileName, bool IsAngled,
70 CharSourceRange FilenameRange, const FileEntry *File,
71 StringRef SearchPath, StringRef RelativePath,
72 const Module *Imported) 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
EndOfMainFile__anonc90c6eea0111::DepCollectorPPCallbacks80 void EndOfMainFile() override {
81 DepCollector.finishedMainFile();
82 }
83 };
84
85 struct DepCollectorASTListener : public ASTReaderListener {
86 DependencyCollector &DepCollector;
DepCollectorASTListener__anonc90c6eea0111::DepCollectorASTListener87 DepCollectorASTListener(DependencyCollector &L) : DepCollector(L) { }
needsInputFileVisitation__anonc90c6eea0111::DepCollectorASTListener88 bool needsInputFileVisitation() override { return true; }
needsSystemInputFileVisitation__anonc90c6eea0111::DepCollectorASTListener89 bool needsSystemInputFileVisitation() override {
90 return DepCollector.needSystemDependencies();
91 }
visitModuleFile__anonc90c6eea0111::DepCollectorASTListener92 void visitModuleFile(StringRef Filename) override {
93 DepCollector.maybeAddDependency(Filename, /*FromModule*/true,
94 /*IsSystem*/false, /*IsModuleFile*/true,
95 /*IsMissing*/false);
96 }
visitInputFile__anonc90c6eea0111::DepCollectorASTListener97 bool visitInputFile(StringRef Filename, bool IsSystem,
98 bool IsOverridden) override {
99 if (IsOverridden)
100 return true;
101
102 DepCollector.maybeAddDependency(Filename, /*FromModule*/true, IsSystem,
103 /*IsModuleFile*/false, /*IsMissing*/false);
104 return true;
105 }
106 };
107 } // end anonymous namespace
108
maybeAddDependency(StringRef Filename,bool FromModule,bool IsSystem,bool IsModuleFile,bool IsMissing)109 void DependencyCollector::maybeAddDependency(StringRef Filename, bool FromModule,
110 bool IsSystem, bool IsModuleFile,
111 bool IsMissing) {
112 if (Seen.insert(Filename).second &&
113 sawDependency(Filename, FromModule, IsSystem, IsModuleFile, IsMissing))
114 Dependencies.push_back(Filename);
115 }
116
isSpecialFilename(StringRef Filename)117 static bool isSpecialFilename(StringRef Filename) {
118 return llvm::StringSwitch<bool>(Filename)
119 .Case("<built-in>", true)
120 .Case("<stdin>", true)
121 .Default(false);
122 }
123
sawDependency(StringRef Filename,bool FromModule,bool IsSystem,bool IsModuleFile,bool IsMissing)124 bool DependencyCollector::sawDependency(StringRef Filename, bool FromModule,
125 bool IsSystem, bool IsModuleFile,
126 bool IsMissing) {
127 return !isSpecialFilename(Filename) &&
128 (needSystemDependencies() || !IsSystem);
129 }
130
~DependencyCollector()131 DependencyCollector::~DependencyCollector() { }
attachToPreprocessor(Preprocessor & PP)132 void DependencyCollector::attachToPreprocessor(Preprocessor &PP) {
133 PP.addPPCallbacks(
134 llvm::make_unique<DepCollectorPPCallbacks>(*this, PP.getSourceManager()));
135 }
attachToASTReader(ASTReader & R)136 void DependencyCollector::attachToASTReader(ASTReader &R) {
137 R.addListener(llvm::make_unique<DepCollectorASTListener>(*this));
138 }
139
140 namespace {
141 /// Private implementation for DependencyFileGenerator
142 class DFGImpl : public PPCallbacks {
143 std::vector<std::string> Files;
144 llvm::StringSet<> FilesSet;
145 const Preprocessor *PP;
146 std::string OutputFile;
147 std::vector<std::string> Targets;
148 bool IncludeSystemHeaders;
149 bool PhonyTarget;
150 bool AddMissingHeaderDeps;
151 bool SeenMissingHeader;
152 bool IncludeModuleFiles;
153 private:
154 bool FileMatchesDepCriteria(const char *Filename,
155 SrcMgr::CharacteristicKind FileType);
156 void OutputDependencyFile();
157
158 public:
DFGImpl(const Preprocessor * _PP,const DependencyOutputOptions & Opts)159 DFGImpl(const Preprocessor *_PP, const DependencyOutputOptions &Opts)
160 : PP(_PP), OutputFile(Opts.OutputFile), Targets(Opts.Targets),
161 IncludeSystemHeaders(Opts.IncludeSystemHeaders),
162 PhonyTarget(Opts.UsePhonyTargets),
163 AddMissingHeaderDeps(Opts.AddMissingHeaderDeps),
164 SeenMissingHeader(false),
165 IncludeModuleFiles(Opts.IncludeModuleFiles) {}
166
167 void FileChanged(SourceLocation Loc, FileChangeReason Reason,
168 SrcMgr::CharacteristicKind FileType,
169 FileID PrevFID) override;
170 void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
171 StringRef FileName, bool IsAngled,
172 CharSourceRange FilenameRange, const FileEntry *File,
173 StringRef SearchPath, StringRef RelativePath,
174 const Module *Imported) override;
175
EndOfMainFile()176 void EndOfMainFile() override {
177 OutputDependencyFile();
178 }
179
180 void AddFilename(StringRef Filename);
includeSystemHeaders() const181 bool includeSystemHeaders() const { return IncludeSystemHeaders; }
includeModuleFiles() const182 bool includeModuleFiles() const { return IncludeModuleFiles; }
183 };
184
185 class DFGASTReaderListener : public ASTReaderListener {
186 DFGImpl &Parent;
187 public:
DFGASTReaderListener(DFGImpl & Parent)188 DFGASTReaderListener(DFGImpl &Parent)
189 : Parent(Parent) { }
needsInputFileVisitation()190 bool needsInputFileVisitation() override { return true; }
needsSystemInputFileVisitation()191 bool needsSystemInputFileVisitation() override {
192 return Parent.includeSystemHeaders();
193 }
194 void visitModuleFile(StringRef Filename) override;
195 bool visitInputFile(StringRef Filename, bool isSystem,
196 bool isOverridden) override;
197 };
198 }
199
DependencyFileGenerator(void * Impl)200 DependencyFileGenerator::DependencyFileGenerator(void *Impl)
201 : Impl(Impl) { }
202
CreateAndAttachToPreprocessor(clang::Preprocessor & PP,const clang::DependencyOutputOptions & Opts)203 DependencyFileGenerator *DependencyFileGenerator::CreateAndAttachToPreprocessor(
204 clang::Preprocessor &PP, const clang::DependencyOutputOptions &Opts) {
205
206 if (Opts.Targets.empty()) {
207 PP.getDiagnostics().Report(diag::err_fe_dependency_file_requires_MT);
208 return nullptr;
209 }
210
211 // Disable the "file not found" diagnostic if the -MG option was given.
212 if (Opts.AddMissingHeaderDeps)
213 PP.SetSuppressIncludeNotFoundError(true);
214
215 DFGImpl *Callback = new DFGImpl(&PP, Opts);
216 PP.addPPCallbacks(std::unique_ptr<PPCallbacks>(Callback));
217 return new DependencyFileGenerator(Callback);
218 }
219
AttachToASTReader(ASTReader & R)220 void DependencyFileGenerator::AttachToASTReader(ASTReader &R) {
221 DFGImpl *I = reinterpret_cast<DFGImpl *>(Impl);
222 assert(I && "missing implementation");
223 R.addListener(llvm::make_unique<DFGASTReaderListener>(*I));
224 }
225
226 /// FileMatchesDepCriteria - Determine whether the given Filename should be
227 /// considered as a dependency.
FileMatchesDepCriteria(const char * Filename,SrcMgr::CharacteristicKind FileType)228 bool DFGImpl::FileMatchesDepCriteria(const char *Filename,
229 SrcMgr::CharacteristicKind FileType) {
230 if (isSpecialFilename(Filename))
231 return false;
232
233 if (IncludeSystemHeaders)
234 return true;
235
236 return FileType == SrcMgr::C_User;
237 }
238
FileChanged(SourceLocation Loc,FileChangeReason Reason,SrcMgr::CharacteristicKind FileType,FileID PrevFID)239 void DFGImpl::FileChanged(SourceLocation Loc,
240 FileChangeReason Reason,
241 SrcMgr::CharacteristicKind FileType,
242 FileID PrevFID) {
243 if (Reason != PPCallbacks::EnterFile)
244 return;
245
246 // Dependency generation really does want to go all the way to the
247 // file entry for a source location to find out what is depended on.
248 // We do not want #line markers to affect dependency generation!
249 SourceManager &SM = PP->getSourceManager();
250
251 const FileEntry *FE =
252 SM.getFileEntryForID(SM.getFileID(SM.getExpansionLoc(Loc)));
253 if (!FE) return;
254
255 StringRef Filename = FE->getName();
256 if (!FileMatchesDepCriteria(Filename.data(), FileType))
257 return;
258
259 // Remove leading "./" (or ".//" or "././" etc.)
260 while (Filename.size() > 2 && Filename[0] == '.' &&
261 llvm::sys::path::is_separator(Filename[1])) {
262 Filename = Filename.substr(1);
263 while (llvm::sys::path::is_separator(Filename[0]))
264 Filename = Filename.substr(1);
265 }
266
267 AddFilename(Filename);
268 }
269
InclusionDirective(SourceLocation HashLoc,const Token & IncludeTok,StringRef FileName,bool IsAngled,CharSourceRange FilenameRange,const FileEntry * File,StringRef SearchPath,StringRef RelativePath,const Module * Imported)270 void DFGImpl::InclusionDirective(SourceLocation HashLoc,
271 const Token &IncludeTok,
272 StringRef FileName,
273 bool IsAngled,
274 CharSourceRange FilenameRange,
275 const FileEntry *File,
276 StringRef SearchPath,
277 StringRef RelativePath,
278 const Module *Imported) {
279 if (!File) {
280 if (AddMissingHeaderDeps)
281 AddFilename(FileName);
282 else
283 SeenMissingHeader = true;
284 }
285 }
286
AddFilename(StringRef Filename)287 void DFGImpl::AddFilename(StringRef Filename) {
288 if (FilesSet.insert(Filename).second)
289 Files.push_back(Filename);
290 }
291
292 /// PrintFilename - GCC escapes spaces, # and $, but apparently not ' or " or
293 /// other scary characters.
PrintFilename(raw_ostream & OS,StringRef Filename)294 static void PrintFilename(raw_ostream &OS, StringRef Filename) {
295 for (unsigned i = 0, e = Filename.size(); i != e; ++i) {
296 if (Filename[i] == ' ' || Filename[i] == '#')
297 OS << '\\';
298 else if (Filename[i] == '$') // $ is escaped by $$.
299 OS << '$';
300 OS << Filename[i];
301 }
302 }
303
OutputDependencyFile()304 void DFGImpl::OutputDependencyFile() {
305 if (SeenMissingHeader) {
306 llvm::sys::fs::remove(OutputFile);
307 return;
308 }
309
310 std::error_code EC;
311 llvm::raw_fd_ostream OS(OutputFile, EC, llvm::sys::fs::F_Text);
312 if (EC) {
313 PP->getDiagnostics().Report(diag::err_fe_error_opening) << OutputFile
314 << EC.message();
315 return;
316 }
317
318 // Write out the dependency targets, trying to avoid overly long
319 // lines when possible. We try our best to emit exactly the same
320 // dependency file as GCC (4.2), assuming the included files are the
321 // same.
322 const unsigned MaxColumns = 75;
323 unsigned Columns = 0;
324
325 for (std::vector<std::string>::iterator
326 I = Targets.begin(), E = Targets.end(); I != E; ++I) {
327 unsigned N = I->length();
328 if (Columns == 0) {
329 Columns += N;
330 } else if (Columns + N + 2 > MaxColumns) {
331 Columns = N + 2;
332 OS << " \\\n ";
333 } else {
334 Columns += N + 1;
335 OS << ' ';
336 }
337 // Targets already quoted as needed.
338 OS << *I;
339 }
340
341 OS << ':';
342 Columns += 1;
343
344 // Now add each dependency in the order it was seen, but avoiding
345 // duplicates.
346 for (std::vector<std::string>::iterator I = Files.begin(),
347 E = Files.end(); I != E; ++I) {
348 // Start a new line if this would exceed the column limit. Make
349 // sure to leave space for a trailing " \" in case we need to
350 // break the line on the next iteration.
351 unsigned N = I->length();
352 if (Columns + (N + 1) + 2 > MaxColumns) {
353 OS << " \\\n ";
354 Columns = 2;
355 }
356 OS << ' ';
357 PrintFilename(OS, *I);
358 Columns += N + 1;
359 }
360 OS << '\n';
361
362 // Create phony targets if requested.
363 if (PhonyTarget && !Files.empty()) {
364 // Skip the first entry, this is always the input file itself.
365 for (std::vector<std::string>::iterator I = Files.begin() + 1,
366 E = Files.end(); I != E; ++I) {
367 OS << '\n';
368 PrintFilename(OS, *I);
369 OS << ":\n";
370 }
371 }
372 }
373
visitInputFile(llvm::StringRef Filename,bool IsSystem,bool IsOverridden)374 bool DFGASTReaderListener::visitInputFile(llvm::StringRef Filename,
375 bool IsSystem, bool IsOverridden) {
376 assert(!IsSystem || needsSystemInputFileVisitation());
377 if (IsOverridden)
378 return true;
379
380 Parent.AddFilename(Filename);
381 return true;
382 }
383
visitModuleFile(llvm::StringRef Filename)384 void DFGASTReaderListener::visitModuleFile(llvm::StringRef Filename) {
385 if (Parent.includeModuleFiles())
386 Parent.AddFilename(Filename);
387 }
388