DependencyGraph.cpp revision 55fc873017f10f6f566b182b70f6fc22aefa3464 
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
25using namespace clang;
26namespace DOT = llvm::DOT;
27
28namespace {
29class 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                         llvm::SmallVector<const FileEntry *, 2> >
36    DependencyMap;
37
38  DependencyMap Dependencies;
39
40private:
41  llvm::raw_ostream &writeNodeReference(llvm::raw_ostream &OS,
42                                        const FileEntry *Node);
43  void OutputGraphFile();
44
45public:
46  DependencyGraphCallback(const Preprocessor *_PP, StringRef OutputFile,
47                          StringRef SysRoot)
48    : PP(_PP), OutputFile(OutputFile.str()), SysRoot(SysRoot.str()) { }
49
50  virtual void InclusionDirective(SourceLocation HashLoc,
51                                  const Token &IncludeTok,
52                                  StringRef FileName,
53                                  bool IsAngled,
54                                  CharSourceRange FilenameRange,
55                                  const FileEntry *File,
56                                  StringRef SearchPath,
57                                  StringRef RelativePath,
58                                  const Module *Imported);
59
60  virtual void EndOfMainFile() {
61    OutputGraphFile();
62  }
63
64};
65}
66
67void clang::AttachDependencyGraphGen(Preprocessor &PP, StringRef OutputFile,
68                                     StringRef SysRoot) {
69  PP.addPPCallbacks(new DependencyGraphCallback(&PP, OutputFile, SysRoot));
70}
71
72void DependencyGraphCallback::InclusionDirective(SourceLocation HashLoc,
73                                                 const Token &IncludeTok,
74                                                 StringRef FileName,
75                                                 bool IsAngled,
76                                                 CharSourceRange FilenameRange,
77                                                 const FileEntry *File,
78                                                 StringRef SearchPath,
79                                                 StringRef RelativePath,
80                                                 const Module *Imported) {
81  if (!File)
82    return;
83
84  SourceManager &SM = PP->getSourceManager();
85  const FileEntry *FromFile
86    = SM.getFileEntryForID(SM.getFileID(SM.getExpansionLoc(HashLoc)));
87  if (FromFile == 0)
88    return;
89
90  Dependencies[FromFile].push_back(File);
91
92  AllFiles.insert(File);
93  AllFiles.insert(FromFile);
94}
95
96llvm::raw_ostream &
97DependencyGraphCallback::writeNodeReference(llvm::raw_ostream &OS,
98                                            const FileEntry *Node) {
99  OS << "header_" << Node->getUID();
100  return OS;
101}
102
103void DependencyGraphCallback::OutputGraphFile() {
104  std::string Err;
105  llvm::raw_fd_ostream OS(OutputFile.c_str(), Err);
106  if (!Err.empty()) {
107    PP->getDiagnostics().Report(diag::err_fe_error_opening)
108      << OutputFile << Err;
109    return;
110  }
111
112  OS << "digraph \"dependencies\" {\n";
113
114  // Write the nodes
115  for (unsigned I = 0, N = AllFiles.size(); I != N; ++I) {
116    // Write the node itself.
117    OS.indent(2);
118    writeNodeReference(OS, AllFiles[I]);
119    OS << " [ shape=\"box\", label=\"";
120    StringRef FileName = AllFiles[I]->getName();
121    if (FileName.startswith(SysRoot))
122      FileName = FileName.substr(SysRoot.size());
123
124    OS << DOT::EscapeString(FileName)
125    << "\"];\n";
126  }
127
128  // Write the edges
129  for (DependencyMap::iterator F = Dependencies.begin(),
130                            FEnd = Dependencies.end();
131       F != FEnd; ++F) {
132    for (unsigned I = 0, N = F->second.size(); I != N; ++I) {
133      OS.indent(2);
134      writeNodeReference(OS, F->first);
135      OS << " -> ";
136      writeNodeReference(OS, F->second[I]);
137      OS << ";\n";
138    }
139  }
140  OS << "}\n";
141}
142
143