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/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 SourceManager &SM;
DepCollectorPPCallbacks__anonf3ab77ae0111::DepCollectorPPCallbacks35 DepCollectorPPCallbacks(DependencyCollector &L, SourceManager &SM)
36 : DepCollector(L), SM(SM) { }
37
FileChanged__anonf3ab77ae0111::DepCollectorPPCallbacks38 void FileChanged(SourceLocation Loc, FileChangeReason Reason,
39 SrcMgr::CharacteristicKind FileType,
40 FileID PrevFID) override {
41 if (Reason != PPCallbacks::EnterFile)
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!
47 const FileEntry *FE =
48 SM.getFileEntryForID(SM.getFileID(SM.getExpansionLoc(Loc)));
49 if (!FE)
50 return;
51
52 StringRef Filename = FE->getName();
53
54 // Remove leading "./" (or ".//" or "././" etc.)
55 while (Filename.size() > 2 && Filename[0] == '.' &&
56 llvm::sys::path::is_separator(Filename[1])) {
57 Filename = Filename.substr(1);
58 while (llvm::sys::path::is_separator(Filename[0]))
59 Filename = Filename.substr(1);
60 }
61
62 DepCollector.maybeAddDependency(Filename, /*FromModule*/false,
63 FileType != SrcMgr::C_User,
64 /*IsModuleFile*/false, /*IsMissing*/false);
65 }
66
InclusionDirective__anonf3ab77ae0111::DepCollectorPPCallbacks67 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) override {
72 if (!File)
73 DepCollector.maybeAddDependency(FileName, /*FromModule*/false,
74 /*IsSystem*/false, /*IsModuleFile*/false,
75 /*IsMissing*/true);
76 // Files that actually exist are handled by FileChanged.
77 }
78
EndOfMainFile__anonf3ab77ae0111::DepCollectorPPCallbacks79 void EndOfMainFile() override {
80 DepCollector.finishedMainFile();
81 }
82 };
83
84 struct DepCollectorASTListener : public ASTReaderListener {
85 DependencyCollector &DepCollector;
DepCollectorASTListener__anonf3ab77ae0111::DepCollectorASTListener86 DepCollectorASTListener(DependencyCollector &L) : DepCollector(L) { }
needsInputFileVisitation__anonf3ab77ae0111::DepCollectorASTListener87 bool needsInputFileVisitation() override { return true; }
needsSystemInputFileVisitation__anonf3ab77ae0111::DepCollectorASTListener88 bool needsSystemInputFileVisitation() override {
89 return DepCollector.needSystemDependencies();
90 }
visitModuleFile__anonf3ab77ae0111::DepCollectorASTListener91 void visitModuleFile(StringRef Filename) override {
92 DepCollector.maybeAddDependency(Filename, /*FromModule*/true,
93 /*IsSystem*/false, /*IsModuleFile*/true,
94 /*IsMissing*/false);
95 }
visitInputFile__anonf3ab77ae0111::DepCollectorASTListener96 bool visitInputFile(StringRef Filename, bool IsSystem,
97 bool IsOverridden) override {
98 if (IsOverridden)
99 return true;
100
101 DepCollector.maybeAddDependency(Filename, /*FromModule*/true, IsSystem,
102 /*IsModuleFile*/false, /*IsMissing*/false);
103 return true;
104 }
105 };
106 } // end anonymous namespace
107
maybeAddDependency(StringRef Filename,bool FromModule,bool IsSystem,bool IsModuleFile,bool IsMissing)108 void DependencyCollector::maybeAddDependency(StringRef Filename, bool FromModule,
109 bool IsSystem, bool IsModuleFile,
110 bool IsMissing) {
111 if (Seen.insert(Filename) &&
112 sawDependency(Filename, FromModule, IsSystem, IsModuleFile, IsMissing))
113 Dependencies.push_back(Filename);
114 }
115
sawDependency(StringRef Filename,bool FromModule,bool IsSystem,bool IsModuleFile,bool IsMissing)116 bool DependencyCollector::sawDependency(StringRef Filename, bool FromModule,
117 bool IsSystem, bool IsModuleFile,
118 bool IsMissing) {
119 return Filename != "<built-in>" && (needSystemDependencies() || !IsSystem);
120 }
121
~DependencyCollector()122 DependencyCollector::~DependencyCollector() { }
attachToPreprocessor(Preprocessor & PP)123 void DependencyCollector::attachToPreprocessor(Preprocessor &PP) {
124 PP.addPPCallbacks(new DepCollectorPPCallbacks(*this, PP.getSourceManager()));
125 }
attachToASTReader(ASTReader & R)126 void DependencyCollector::attachToASTReader(ASTReader &R) {
127 R.addListener(new DepCollectorASTListener(*this));
128 }
129
130 namespace {
131 /// Private implementation for DependencyFileGenerator
132 class DFGImpl : public PPCallbacks {
133 std::vector<std::string> Files;
134 llvm::StringSet<> FilesSet;
135 const Preprocessor *PP;
136 std::string OutputFile;
137 std::vector<std::string> Targets;
138 bool IncludeSystemHeaders;
139 bool PhonyTarget;
140 bool AddMissingHeaderDeps;
141 bool SeenMissingHeader;
142 bool IncludeModuleFiles;
143 private:
144 bool FileMatchesDepCriteria(const char *Filename,
145 SrcMgr::CharacteristicKind FileType);
146 void OutputDependencyFile();
147
148 public:
DFGImpl(const Preprocessor * _PP,const DependencyOutputOptions & Opts)149 DFGImpl(const Preprocessor *_PP, const DependencyOutputOptions &Opts)
150 : PP(_PP), OutputFile(Opts.OutputFile), Targets(Opts.Targets),
151 IncludeSystemHeaders(Opts.IncludeSystemHeaders),
152 PhonyTarget(Opts.UsePhonyTargets),
153 AddMissingHeaderDeps(Opts.AddMissingHeaderDeps),
154 SeenMissingHeader(false),
155 IncludeModuleFiles(Opts.IncludeModuleFiles) {}
156
157 void FileChanged(SourceLocation Loc, FileChangeReason Reason,
158 SrcMgr::CharacteristicKind FileType,
159 FileID PrevFID) override;
160 void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
161 StringRef FileName, bool IsAngled,
162 CharSourceRange FilenameRange, const FileEntry *File,
163 StringRef SearchPath, StringRef RelativePath,
164 const Module *Imported) override;
165
EndOfMainFile()166 void EndOfMainFile() override {
167 OutputDependencyFile();
168 }
169
170 void AddFilename(StringRef Filename);
includeSystemHeaders() const171 bool includeSystemHeaders() const { return IncludeSystemHeaders; }
includeModuleFiles() const172 bool includeModuleFiles() const { return IncludeModuleFiles; }
173 };
174
175 class DFGASTReaderListener : public ASTReaderListener {
176 DFGImpl &Parent;
177 public:
DFGASTReaderListener(DFGImpl & Parent)178 DFGASTReaderListener(DFGImpl &Parent)
179 : Parent(Parent) { }
needsInputFileVisitation()180 bool needsInputFileVisitation() override { return true; }
needsSystemInputFileVisitation()181 bool needsSystemInputFileVisitation() override {
182 return Parent.includeSystemHeaders();
183 }
184 void visitModuleFile(StringRef Filename) override;
185 bool visitInputFile(StringRef Filename, bool isSystem,
186 bool isOverridden) override;
187 };
188 }
189
DependencyFileGenerator(void * Impl)190 DependencyFileGenerator::DependencyFileGenerator(void *Impl)
191 : Impl(Impl) { }
192
CreateAndAttachToPreprocessor(clang::Preprocessor & PP,const clang::DependencyOutputOptions & Opts)193 DependencyFileGenerator *DependencyFileGenerator::CreateAndAttachToPreprocessor(
194 clang::Preprocessor &PP, const clang::DependencyOutputOptions &Opts) {
195
196 if (Opts.Targets.empty()) {
197 PP.getDiagnostics().Report(diag::err_fe_dependency_file_requires_MT);
198 return nullptr;
199 }
200
201 // Disable the "file not found" diagnostic if the -MG option was given.
202 if (Opts.AddMissingHeaderDeps)
203 PP.SetSuppressIncludeNotFoundError(true);
204
205 DFGImpl *Callback = new DFGImpl(&PP, Opts);
206 PP.addPPCallbacks(Callback); // PP owns the Callback
207 return new DependencyFileGenerator(Callback);
208 }
209
AttachToASTReader(ASTReader & R)210 void DependencyFileGenerator::AttachToASTReader(ASTReader &R) {
211 DFGImpl *I = reinterpret_cast<DFGImpl *>(Impl);
212 assert(I && "missing implementation");
213 R.addListener(new DFGASTReaderListener(*I));
214 }
215
216 /// FileMatchesDepCriteria - Determine whether the given Filename should be
217 /// considered as a dependency.
FileMatchesDepCriteria(const char * Filename,SrcMgr::CharacteristicKind FileType)218 bool DFGImpl::FileMatchesDepCriteria(const char *Filename,
219 SrcMgr::CharacteristicKind FileType) {
220 if (strcmp("<built-in>", Filename) == 0)
221 return false;
222
223 if (IncludeSystemHeaders)
224 return true;
225
226 return FileType == SrcMgr::C_User;
227 }
228
FileChanged(SourceLocation Loc,FileChangeReason Reason,SrcMgr::CharacteristicKind FileType,FileID PrevFID)229 void DFGImpl::FileChanged(SourceLocation Loc,
230 FileChangeReason Reason,
231 SrcMgr::CharacteristicKind FileType,
232 FileID PrevFID) {
233 if (Reason != PPCallbacks::EnterFile)
234 return;
235
236 // Dependency generation really does want to go all the way to the
237 // file entry for a source location to find out what is depended on.
238 // We do not want #line markers to affect dependency generation!
239 SourceManager &SM = PP->getSourceManager();
240
241 const FileEntry *FE =
242 SM.getFileEntryForID(SM.getFileID(SM.getExpansionLoc(Loc)));
243 if (!FE) return;
244
245 StringRef Filename = FE->getName();
246 if (!FileMatchesDepCriteria(Filename.data(), FileType))
247 return;
248
249 // Remove leading "./" (or ".//" or "././" etc.)
250 while (Filename.size() > 2 && Filename[0] == '.' &&
251 llvm::sys::path::is_separator(Filename[1])) {
252 Filename = Filename.substr(1);
253 while (llvm::sys::path::is_separator(Filename[0]))
254 Filename = Filename.substr(1);
255 }
256
257 AddFilename(Filename);
258 }
259
InclusionDirective(SourceLocation HashLoc,const Token & IncludeTok,StringRef FileName,bool IsAngled,CharSourceRange FilenameRange,const FileEntry * File,StringRef SearchPath,StringRef RelativePath,const Module * Imported)260 void DFGImpl::InclusionDirective(SourceLocation HashLoc,
261 const Token &IncludeTok,
262 StringRef FileName,
263 bool IsAngled,
264 CharSourceRange FilenameRange,
265 const FileEntry *File,
266 StringRef SearchPath,
267 StringRef RelativePath,
268 const Module *Imported) {
269 if (!File) {
270 if (AddMissingHeaderDeps)
271 AddFilename(FileName);
272 else
273 SeenMissingHeader = true;
274 }
275 }
276
AddFilename(StringRef Filename)277 void DFGImpl::AddFilename(StringRef Filename) {
278 if (FilesSet.insert(Filename))
279 Files.push_back(Filename);
280 }
281
282 /// PrintFilename - GCC escapes spaces, # and $, but apparently not ' or " or
283 /// other scary characters.
PrintFilename(raw_ostream & OS,StringRef Filename)284 static void PrintFilename(raw_ostream &OS, StringRef Filename) {
285 for (unsigned i = 0, e = Filename.size(); i != e; ++i) {
286 if (Filename[i] == ' ' || Filename[i] == '#')
287 OS << '\\';
288 else if (Filename[i] == '$') // $ is escaped by $$.
289 OS << '$';
290 OS << Filename[i];
291 }
292 }
293
OutputDependencyFile()294 void DFGImpl::OutputDependencyFile() {
295 if (SeenMissingHeader) {
296 llvm::sys::fs::remove(OutputFile);
297 return;
298 }
299
300 std::string Err;
301 llvm::raw_fd_ostream OS(OutputFile.c_str(), Err, llvm::sys::fs::F_Text);
302 if (!Err.empty()) {
303 PP->getDiagnostics().Report(diag::err_fe_error_opening)
304 << OutputFile << Err;
305 return;
306 }
307
308 // Write out the dependency targets, trying to avoid overly long
309 // lines when possible. We try our best to emit exactly the same
310 // dependency file as GCC (4.2), assuming the included files are the
311 // same.
312 const unsigned MaxColumns = 75;
313 unsigned Columns = 0;
314
315 for (std::vector<std::string>::iterator
316 I = Targets.begin(), E = Targets.end(); I != E; ++I) {
317 unsigned N = I->length();
318 if (Columns == 0) {
319 Columns += N;
320 } else if (Columns + N + 2 > MaxColumns) {
321 Columns = N + 2;
322 OS << " \\\n ";
323 } else {
324 Columns += N + 1;
325 OS << ' ';
326 }
327 // Targets already quoted as needed.
328 OS << *I;
329 }
330
331 OS << ':';
332 Columns += 1;
333
334 // Now add each dependency in the order it was seen, but avoiding
335 // duplicates.
336 for (std::vector<std::string>::iterator I = Files.begin(),
337 E = Files.end(); I != E; ++I) {
338 // Start a new line if this would exceed the column limit. Make
339 // sure to leave space for a trailing " \" in case we need to
340 // break the line on the next iteration.
341 unsigned N = I->length();
342 if (Columns + (N + 1) + 2 > MaxColumns) {
343 OS << " \\\n ";
344 Columns = 2;
345 }
346 OS << ' ';
347 PrintFilename(OS, *I);
348 Columns += N + 1;
349 }
350 OS << '\n';
351
352 // Create phony targets if requested.
353 if (PhonyTarget && !Files.empty()) {
354 // Skip the first entry, this is always the input file itself.
355 for (std::vector<std::string>::iterator I = Files.begin() + 1,
356 E = Files.end(); I != E; ++I) {
357 OS << '\n';
358 PrintFilename(OS, *I);
359 OS << ":\n";
360 }
361 }
362 }
363
visitInputFile(llvm::StringRef Filename,bool IsSystem,bool IsOverridden)364 bool DFGASTReaderListener::visitInputFile(llvm::StringRef Filename,
365 bool IsSystem, bool IsOverridden) {
366 assert(!IsSystem || needsSystemInputFileVisitation());
367 if (IsOverridden)
368 return true;
369
370 Parent.AddFilename(Filename);
371 return true;
372 }
373
visitModuleFile(llvm::StringRef Filename)374 void DFGASTReaderListener::visitModuleFile(llvm::StringRef Filename) {
375 if (Parent.includeModuleFiles())
376 Parent.AddFilename(Filename);
377 }
378