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: 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 *SuggestedModule, 53 bool ModuleImported, 54 SrcMgr::CharacteristicKind FileType) override; 55 56 void EndOfMainFile() override { 57 OutputGraphFile(); 58 } 59 60 }; 61 } 62 63 void clang::AttachDependencyGraphGen(Preprocessor &PP, StringRef OutputFile, 64 StringRef SysRoot) { 65 PP.addPPCallbacks(std::make_unique<DependencyGraphCallback>(&PP, OutputFile, 66 SysRoot)); 67 } 68 69 void DependencyGraphCallback::InclusionDirective( 70 SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName, 71 bool IsAngled, CharSourceRange FilenameRange, OptionalFileEntryRef File, 72 StringRef SearchPath, StringRef RelativePath, const Module *SuggestedModule, 73 bool ModuleImported, SrcMgr::CharacteristicKind FileType) { 74 if (!File) 75 return; 76 77 SourceManager &SM = PP->getSourceManager(); 78 OptionalFileEntryRef FromFile = 79 SM.getFileEntryRefForID(SM.getFileID(SM.getExpansionLoc(HashLoc))); 80 if (!FromFile) 81 return; 82 83 Dependencies[*FromFile].push_back(*File); 84 85 AllFiles.insert(*File); 86 AllFiles.insert(*FromFile); 87 } 88 89 raw_ostream & 90 DependencyGraphCallback::writeNodeReference(raw_ostream &OS, 91 const FileEntry *Node) { 92 OS << "header_" << Node->getUID(); 93 return OS; 94 } 95 96 void DependencyGraphCallback::OutputGraphFile() { 97 std::error_code EC; 98 llvm::raw_fd_ostream OS(OutputFile, EC, llvm::sys::fs::OF_TextWithCRLF); 99 if (EC) { 100 PP->getDiagnostics().Report(diag::err_fe_error_opening) << OutputFile 101 << EC.message(); 102 return; 103 } 104 105 OS << "digraph \"dependencies\" {\n"; 106 107 // Write the nodes 108 for (unsigned I = 0, N = AllFiles.size(); I != N; ++I) { 109 // Write the node itself. 110 OS.indent(2); 111 writeNodeReference(OS, AllFiles[I]); 112 OS << " [ shape=\"box\", label=\""; 113 StringRef FileName = AllFiles[I].getName(); 114 FileName.consume_front(SysRoot); 115 116 OS << DOT::EscapeString(std::string(FileName)) << "\"];\n"; 117 } 118 119 // Write the edges 120 for (DependencyMap::iterator F = Dependencies.begin(), 121 FEnd = Dependencies.end(); 122 F != FEnd; ++F) { 123 for (unsigned I = 0, N = F->second.size(); I != N; ++I) { 124 OS.indent(2); 125 writeNodeReference(OS, F->first); 126 OS << " -> "; 127 writeNodeReference(OS, F->second[I]); 128 OS << ";\n"; 129 } 130 } 131 OS << "}\n"; 132 } 133 134