xref: /llvm-project/clang/lib/Frontend/DependencyGraph.cpp (revision 83d46be31e56be9708495a832345bcec7499f904)
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 GraphViz format.
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/FrontendDiagnostic.h"
18 #include "clang/Lex/PPCallbacks.h"
19 #include "clang/Lex/Preprocessor.h"
20 #include "llvm/ADT/SetVector.h"
21 #include "llvm/Support/raw_ostream.h"
22 #include "llvm/Support/GraphWriter.h"
23 
24 using namespace clang;
25 namespace DOT = llvm::DOT;
26 
27 namespace {
28 class DependencyGraphCallback : public PPCallbacks {
29   const Preprocessor *PP;
30   std::string OutputFile;
31   std::string SysRoot;
32   llvm::SetVector<const FileEntry *> AllFiles;
33   typedef llvm::DenseMap<const FileEntry *,
34                          llvm::SmallVector<const FileEntry *, 2> >
35     DependencyMap;
36 
37   DependencyMap Dependencies;
38 
39 private:
40   llvm::raw_ostream &writeNodeReference(llvm::raw_ostream &OS,
41                                         const FileEntry *Node);
42   void OutputGraphFile();
43 
44 public:
45   DependencyGraphCallback(const Preprocessor *_PP, StringRef OutputFile,
46                           StringRef SysRoot)
47     : PP(_PP), OutputFile(OutputFile.str()), SysRoot(SysRoot.str()) { }
48 
49   virtual void InclusionDirective(SourceLocation HashLoc,
50                                   const Token &IncludeTok,
51                                   StringRef FileName,
52                                   bool IsAngled,
53                                   const FileEntry *File,
54                                   SourceLocation EndLoc,
55                                   StringRef SearchPath,
56                                   StringRef RelativePath);
57 
58   virtual void EndOfMainFile() {
59     OutputGraphFile();
60   }
61 
62 };
63 }
64 
65 void clang::AttachDependencyGraphGen(Preprocessor &PP, StringRef OutputFile,
66                                      StringRef SysRoot) {
67   PP.addPPCallbacks(new DependencyGraphCallback(&PP, OutputFile, SysRoot));
68 }
69 
70 void DependencyGraphCallback::InclusionDirective(SourceLocation HashLoc,
71                                                  const Token &IncludeTok,
72                                                  StringRef FileName,
73                                                  bool IsAngled,
74                                                  const FileEntry *File,
75                                                  SourceLocation EndLoc,
76                                                  StringRef SearchPath,
77                                                  StringRef RelativePath) {
78   if (!File)
79     return;
80 
81   SourceManager &SM = PP->getSourceManager();
82   const FileEntry *FromFile
83     = SM.getFileEntryForID(SM.getFileID(SM.getExpansionLoc(HashLoc)));
84   if (FromFile == 0)
85     return;
86 
87   Dependencies[FromFile].push_back(File);
88 
89   AllFiles.insert(File);
90   AllFiles.insert(FromFile);
91 }
92 
93 llvm::raw_ostream &
94 DependencyGraphCallback::writeNodeReference(llvm::raw_ostream &OS,
95                                             const FileEntry *Node) {
96   OS << "header_" << Node->getUID();
97   return OS;
98 }
99 
100 void DependencyGraphCallback::OutputGraphFile() {
101   std::string Err;
102   llvm::raw_fd_ostream OS(OutputFile.c_str(), Err);
103   if (!Err.empty()) {
104     PP->getDiagnostics().Report(diag::err_fe_error_opening)
105       << OutputFile << Err;
106     return;
107   }
108 
109   OS << "digraph \"dependencies\" {\n";
110 
111   // Write the nodes
112   for (unsigned I = 0, N = AllFiles.size(); I != N; ++I) {
113     // Write the node itself.
114     OS.indent(2);
115     writeNodeReference(OS, AllFiles[I]);
116     OS << " [ shape=\"box\", label=\"";
117     StringRef FileName = AllFiles[I]->getName();
118     if (FileName.startswith(SysRoot))
119       FileName = FileName.substr(SysRoot.size());
120 
121     OS << DOT::EscapeString(FileName)
122     << "\"];\n";
123   }
124 
125   // Write the edges
126   for (DependencyMap::iterator F = Dependencies.begin(),
127                             FEnd = Dependencies.end();
128        F != FEnd; ++F) {
129     for (unsigned I = 0, N = F->second.size(); I != N; ++I) {
130       OS.indent(2);
131       writeNodeReference(OS, F->first);
132       OS << " -> ";
133       writeNodeReference(OS, F->second[I]);
134       OS << ";\n";
135     }
136   }
137   OS << "}\n";
138 }
139 
140