1 //===--- DependencyGraph.cpp - Generate dependency file -------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This code generates a header dependency graph in DOT format, for use
10 // with, e.g., GraphViz.
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/GraphWriter.h"
22 #include "llvm/Support/raw_ostream.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<FileEntryRef> AllFiles;
33 using DependencyMap =
34 llvm::DenseMap<FileEntryRef, SmallVector<FileEntryRef, 2>>;
35
36 DependencyMap Dependencies;
37
38 private:
39 raw_ostream &writeNodeReference(raw_ostream &OS,
40 const FileEntry *Node);
41 void OutputGraphFile();
42
43 public:
DependencyGraphCallback(const Preprocessor * _PP,StringRef OutputFile,StringRef SysRoot)44 DependencyGraphCallback(const Preprocessor *_PP, StringRef OutputFile,
45 StringRef SysRoot)
46 : PP(_PP), OutputFile(OutputFile.str()), SysRoot(SysRoot.str()) { }
47
48 void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
49 StringRef FileName, bool IsAngled,
50 CharSourceRange FilenameRange,
51 OptionalFileEntryRef File, StringRef SearchPath,
52 StringRef RelativePath, const Module *Imported,
53 SrcMgr::CharacteristicKind FileType) 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(std::make_unique<DependencyGraphCallback>(&PP, OutputFile,
65 SysRoot));
66 }
67
InclusionDirective(SourceLocation HashLoc,const Token & IncludeTok,StringRef FileName,bool IsAngled,CharSourceRange FilenameRange,OptionalFileEntryRef File,StringRef SearchPath,StringRef RelativePath,const Module * Imported,SrcMgr::CharacteristicKind FileType)68 void DependencyGraphCallback::InclusionDirective(
69 SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
70 bool IsAngled, CharSourceRange FilenameRange, OptionalFileEntryRef File,
71 StringRef SearchPath, StringRef RelativePath, const Module *Imported,
72 SrcMgr::CharacteristicKind FileType) {
73 if (!File)
74 return;
75
76 SourceManager &SM = PP->getSourceManager();
77 OptionalFileEntryRef FromFile =
78 SM.getFileEntryRefForID(SM.getFileID(SM.getExpansionLoc(HashLoc)));
79 if (!FromFile)
80 return;
81
82 Dependencies[*FromFile].push_back(*File);
83
84 AllFiles.insert(*File);
85 AllFiles.insert(*FromFile);
86 }
87
88 raw_ostream &
writeNodeReference(raw_ostream & OS,const FileEntry * Node)89 DependencyGraphCallback::writeNodeReference(raw_ostream &OS,
90 const FileEntry *Node) {
91 OS << "header_" << Node->getUID();
92 return OS;
93 }
94
OutputGraphFile()95 void DependencyGraphCallback::OutputGraphFile() {
96 std::error_code EC;
97 llvm::raw_fd_ostream OS(OutputFile, EC, llvm::sys::fs::OF_TextWithCRLF);
98 if (EC) {
99 PP->getDiagnostics().Report(diag::err_fe_error_opening) << OutputFile
100 << EC.message();
101 return;
102 }
103
104 OS << "digraph \"dependencies\" {\n";
105
106 // Write the nodes
107 for (unsigned I = 0, N = AllFiles.size(); I != N; ++I) {
108 // Write the node itself.
109 OS.indent(2);
110 writeNodeReference(OS, AllFiles[I]);
111 OS << " [ shape=\"box\", label=\"";
112 StringRef FileName = AllFiles[I].getName();
113 FileName.consume_front(SysRoot);
114
115 OS << DOT::EscapeString(std::string(FileName)) << "\"];\n";
116 }
117
118 // Write the edges
119 for (DependencyMap::iterator F = Dependencies.begin(),
120 FEnd = Dependencies.end();
121 F != FEnd; ++F) {
122 for (unsigned I = 0, N = F->second.size(); I != N; ++I) {
123 OS.indent(2);
124 writeNodeReference(OS, F->first);
125 OS << " -> ";
126 writeNodeReference(OS, F->second[I]);
127 OS << ";\n";
128 }
129 }
130 OS << "}\n";
131 }
132
133