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1 //===--- DependencyGraph.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 a header dependency graph in DOT format, for use
11 // with, e.g., GraphViz.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "clang/Frontend/Utils.h"
16 #include "clang/Basic/FileManager.h"
17 #include "clang/Basic/SourceManager.h"
18 #include "clang/Frontend/FrontendDiagnostic.h"
19 #include "clang/Lex/PPCallbacks.h"
20 #include "clang/Lex/Preprocessor.h"
21 #include "llvm/ADT/SetVector.h"
22 #include "llvm/Support/GraphWriter.h"
23 #include "llvm/Support/raw_ostream.h"
24 
25 using namespace clang;
26 namespace DOT = llvm::DOT;
27 
28 namespace {
29 class DependencyGraphCallback : public PPCallbacks {
30   const Preprocessor *PP;
31   std::string OutputFile;
32   std::string SysRoot;
33   llvm::SetVector<const FileEntry *> AllFiles;
34   typedef llvm::DenseMap<const FileEntry *,
35                          SmallVector<const FileEntry *, 2> > DependencyMap;
36 
37   DependencyMap Dependencies;
38 
39 private:
40   raw_ostream &writeNodeReference(raw_ostream &OS,
41                                   const FileEntry *Node);
42   void OutputGraphFile();
43 
44 public:
DependencyGraphCallback(const Preprocessor * _PP,StringRef OutputFile,StringRef SysRoot)45   DependencyGraphCallback(const Preprocessor *_PP, StringRef OutputFile,
46                           StringRef SysRoot)
47     : PP(_PP), OutputFile(OutputFile.str()), SysRoot(SysRoot.str()) { }
48 
49   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
50                           StringRef FileName, bool IsAngled,
51                           CharSourceRange FilenameRange, const FileEntry *File,
52                           StringRef SearchPath, StringRef RelativePath,
53                           const Module *Imported) override;
54 
EndOfMainFile()55   void EndOfMainFile() override {
56     OutputGraphFile();
57   }
58 
59 };
60 }
61 
AttachDependencyGraphGen(Preprocessor & PP,StringRef OutputFile,StringRef SysRoot)62 void clang::AttachDependencyGraphGen(Preprocessor &PP, StringRef OutputFile,
63                                      StringRef SysRoot) {
64   PP.addPPCallbacks(llvm::make_unique<DependencyGraphCallback>(&PP, OutputFile,
65                                                                SysRoot));
66 }
67 
InclusionDirective(SourceLocation HashLoc,const Token & IncludeTok,StringRef FileName,bool IsAngled,CharSourceRange FilenameRange,const FileEntry * File,StringRef SearchPath,StringRef RelativePath,const Module * Imported)68 void DependencyGraphCallback::InclusionDirective(SourceLocation HashLoc,
69                                                  const Token &IncludeTok,
70                                                  StringRef FileName,
71                                                  bool IsAngled,
72                                                  CharSourceRange FilenameRange,
73                                                  const FileEntry *File,
74                                                  StringRef SearchPath,
75                                                  StringRef RelativePath,
76                                                  const Module *Imported) {
77   if (!File)
78     return;
79 
80   SourceManager &SM = PP->getSourceManager();
81   const FileEntry *FromFile
82     = SM.getFileEntryForID(SM.getFileID(SM.getExpansionLoc(HashLoc)));
83   if (!FromFile)
84     return;
85 
86   Dependencies[FromFile].push_back(File);
87 
88   AllFiles.insert(File);
89   AllFiles.insert(FromFile);
90 }
91 
92 raw_ostream &
writeNodeReference(raw_ostream & OS,const FileEntry * Node)93 DependencyGraphCallback::writeNodeReference(raw_ostream &OS,
94                                             const FileEntry *Node) {
95   OS << "header_" << Node->getUID();
96   return OS;
97 }
98 
OutputGraphFile()99 void DependencyGraphCallback::OutputGraphFile() {
100   std::error_code EC;
101   llvm::raw_fd_ostream OS(OutputFile, EC, llvm::sys::fs::F_Text);
102   if (EC) {
103     PP->getDiagnostics().Report(diag::err_fe_error_opening) << OutputFile
104                                                             << EC.message();
105     return;
106   }
107 
108   OS << "digraph \"dependencies\" {\n";
109 
110   // Write the nodes
111   for (unsigned I = 0, N = AllFiles.size(); I != N; ++I) {
112     // Write the node itself.
113     OS.indent(2);
114     writeNodeReference(OS, AllFiles[I]);
115     OS << " [ shape=\"box\", label=\"";
116     StringRef FileName = AllFiles[I]->getName();
117     if (FileName.startswith(SysRoot))
118       FileName = FileName.substr(SysRoot.size());
119 
120     OS << DOT::EscapeString(FileName)
121     << "\"];\n";
122   }
123 
124   // Write the edges
125   for (DependencyMap::iterator F = Dependencies.begin(),
126                             FEnd = Dependencies.end();
127        F != FEnd; ++F) {
128     for (unsigned I = 0, N = F->second.size(); I != N; ++I) {
129       OS.indent(2);
130       writeNodeReference(OS, F->first);
131       OS << " -> ";
132       writeNodeReference(OS, F->second[I]);
133       OS << ";\n";
134     }
135   }
136   OS << "}\n";
137 }
138 
139