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 "llvm/ADT/StringSet.h"
24 #include "llvm/Support/Path.h"
25 #include "llvm/Support/raw_ostream.h"
26
27 using namespace clang;
28
29 namespace {
30 class DependencyFileCallback : public PPCallbacks {
31 std::vector<std::string> Files;
32 llvm::StringSet<> FilesSet;
33 const Preprocessor *PP;
34 std::string OutputFile;
35 std::vector<std::string> Targets;
36 bool IncludeSystemHeaders;
37 bool PhonyTarget;
38 bool AddMissingHeaderDeps;
39 bool SeenMissingHeader;
40 private:
41 bool FileMatchesDepCriteria(const char *Filename,
42 SrcMgr::CharacteristicKind FileType);
43 void AddFilename(StringRef Filename);
44 void OutputDependencyFile();
45
46 public:
DependencyFileCallback(const Preprocessor * _PP,const DependencyOutputOptions & Opts)47 DependencyFileCallback(const Preprocessor *_PP,
48 const DependencyOutputOptions &Opts)
49 : PP(_PP), OutputFile(Opts.OutputFile), Targets(Opts.Targets),
50 IncludeSystemHeaders(Opts.IncludeSystemHeaders),
51 PhonyTarget(Opts.UsePhonyTargets),
52 AddMissingHeaderDeps(Opts.AddMissingHeaderDeps),
53 SeenMissingHeader(false) {}
54
55 virtual void FileChanged(SourceLocation Loc, FileChangeReason Reason,
56 SrcMgr::CharacteristicKind FileType,
57 FileID PrevFID);
58 virtual void InclusionDirective(SourceLocation HashLoc,
59 const Token &IncludeTok,
60 StringRef FileName,
61 bool IsAngled,
62 CharSourceRange FilenameRange,
63 const FileEntry *File,
64 StringRef SearchPath,
65 StringRef RelativePath,
66 const Module *Imported);
67
EndOfMainFile()68 virtual void EndOfMainFile() {
69 OutputDependencyFile();
70 }
71 };
72 }
73
AttachDependencyFileGen(Preprocessor & PP,const DependencyOutputOptions & Opts)74 void clang::AttachDependencyFileGen(Preprocessor &PP,
75 const DependencyOutputOptions &Opts) {
76 if (Opts.Targets.empty()) {
77 PP.getDiagnostics().Report(diag::err_fe_dependency_file_requires_MT);
78 return;
79 }
80
81 // Disable the "file not found" diagnostic if the -MG option was given.
82 if (Opts.AddMissingHeaderDeps)
83 PP.SetSuppressIncludeNotFoundError(true);
84
85 PP.addPPCallbacks(new DependencyFileCallback(&PP, Opts));
86 }
87
88 /// FileMatchesDepCriteria - Determine whether the given Filename should be
89 /// considered as a dependency.
FileMatchesDepCriteria(const char * Filename,SrcMgr::CharacteristicKind FileType)90 bool DependencyFileCallback::FileMatchesDepCriteria(const char *Filename,
91 SrcMgr::CharacteristicKind FileType) {
92 if (strcmp("<built-in>", Filename) == 0)
93 return false;
94
95 if (IncludeSystemHeaders)
96 return true;
97
98 return FileType == SrcMgr::C_User;
99 }
100
FileChanged(SourceLocation Loc,FileChangeReason Reason,SrcMgr::CharacteristicKind FileType,FileID PrevFID)101 void DependencyFileCallback::FileChanged(SourceLocation Loc,
102 FileChangeReason Reason,
103 SrcMgr::CharacteristicKind FileType,
104 FileID PrevFID) {
105 if (Reason != PPCallbacks::EnterFile)
106 return;
107
108 // Dependency generation really does want to go all the way to the
109 // file entry for a source location to find out what is depended on.
110 // We do not want #line markers to affect dependency generation!
111 SourceManager &SM = PP->getSourceManager();
112
113 const FileEntry *FE =
114 SM.getFileEntryForID(SM.getFileID(SM.getExpansionLoc(Loc)));
115 if (FE == 0) return;
116
117 StringRef Filename = FE->getName();
118 if (!FileMatchesDepCriteria(Filename.data(), FileType))
119 return;
120
121 // Remove leading "./" (or ".//" or "././" etc.)
122 while (Filename.size() > 2 && Filename[0] == '.' &&
123 llvm::sys::path::is_separator(Filename[1])) {
124 Filename = Filename.substr(1);
125 while (llvm::sys::path::is_separator(Filename[0]))
126 Filename = Filename.substr(1);
127 }
128
129 AddFilename(Filename);
130 }
131
InclusionDirective(SourceLocation HashLoc,const Token & IncludeTok,StringRef FileName,bool IsAngled,CharSourceRange FilenameRange,const FileEntry * File,StringRef SearchPath,StringRef RelativePath,const Module * Imported)132 void DependencyFileCallback::InclusionDirective(SourceLocation HashLoc,
133 const Token &IncludeTok,
134 StringRef FileName,
135 bool IsAngled,
136 CharSourceRange FilenameRange,
137 const FileEntry *File,
138 StringRef SearchPath,
139 StringRef RelativePath,
140 const Module *Imported) {
141 if (!File) {
142 if (AddMissingHeaderDeps)
143 AddFilename(FileName);
144 else
145 SeenMissingHeader = true;
146 }
147 }
148
AddFilename(StringRef Filename)149 void DependencyFileCallback::AddFilename(StringRef Filename) {
150 if (FilesSet.insert(Filename))
151 Files.push_back(Filename);
152 }
153
154 /// PrintFilename - GCC escapes spaces, but apparently not ' or " or other
155 /// scary characters.
PrintFilename(raw_ostream & OS,StringRef Filename)156 static void PrintFilename(raw_ostream &OS, StringRef Filename) {
157 for (unsigned i = 0, e = Filename.size(); i != e; ++i) {
158 if (Filename[i] == ' ')
159 OS << '\\';
160 OS << Filename[i];
161 }
162 }
163
OutputDependencyFile()164 void DependencyFileCallback::OutputDependencyFile() {
165 if (SeenMissingHeader) {
166 llvm::sys::Path(OutputFile).eraseFromDisk();
167 return;
168 }
169
170 std::string Err;
171 llvm::raw_fd_ostream OS(OutputFile.c_str(), Err);
172 if (!Err.empty()) {
173 PP->getDiagnostics().Report(diag::err_fe_error_opening)
174 << OutputFile << Err;
175 return;
176 }
177
178 // Write out the dependency targets, trying to avoid overly long
179 // lines when possible. We try our best to emit exactly the same
180 // dependency file as GCC (4.2), assuming the included files are the
181 // same.
182 const unsigned MaxColumns = 75;
183 unsigned Columns = 0;
184
185 for (std::vector<std::string>::iterator
186 I = Targets.begin(), E = Targets.end(); I != E; ++I) {
187 unsigned N = I->length();
188 if (Columns == 0) {
189 Columns += N;
190 } else if (Columns + N + 2 > MaxColumns) {
191 Columns = N + 2;
192 OS << " \\\n ";
193 } else {
194 Columns += N + 1;
195 OS << ' ';
196 }
197 // Targets already quoted as needed.
198 OS << *I;
199 }
200
201 OS << ':';
202 Columns += 1;
203
204 // Now add each dependency in the order it was seen, but avoiding
205 // duplicates.
206 for (std::vector<std::string>::iterator I = Files.begin(),
207 E = Files.end(); I != E; ++I) {
208 // Start a new line if this would exceed the column limit. Make
209 // sure to leave space for a trailing " \" in case we need to
210 // break the line on the next iteration.
211 unsigned N = I->length();
212 if (Columns + (N + 1) + 2 > MaxColumns) {
213 OS << " \\\n ";
214 Columns = 2;
215 }
216 OS << ' ';
217 PrintFilename(OS, *I);
218 Columns += N + 1;
219 }
220 OS << '\n';
221
222 // Create phony targets if requested.
223 if (PhonyTarget && !Files.empty()) {
224 // Skip the first entry, this is always the input file itself.
225 for (std::vector<std::string>::iterator I = Files.begin() + 1,
226 E = Files.end(); I != E; ++I) {
227 OS << '\n';
228 PrintFilename(OS, *I);
229 OS << ":\n";
230 }
231 }
232 }
233
234