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 *Imported, 53 SrcMgr::CharacteristicKind FileType) override; 54 55 void EndOfMainFile() override { 56 OutputGraphFile(); 57 } 58 59 }; 60 } 61 62 void clang::AttachDependencyGraphGen(Preprocessor &PP, StringRef OutputFile, 63 StringRef SysRoot) { 64 PP.addPPCallbacks(std::make_unique<DependencyGraphCallback>(&PP, OutputFile, 65 SysRoot)); 66 } 67 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 & 89 DependencyGraphCallback::writeNodeReference(raw_ostream &OS, 90 const FileEntry *Node) { 91 OS << "header_" << Node->getUID(); 92 return OS; 93 } 94 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