1 //===- InheritViz.cpp - Graphviz visualization for inheritance --*- C++ -*-===// 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 file implements CXXRecordDecl::viewInheritance, which 11 // generates a GraphViz DOT file that depicts the class inheritance 12 // diagram and then calls Graphviz/dot+gv on it. 13 // 14 //===----------------------------------------------------------------------===// 15 16 #include "clang/AST/ASTContext.h" 17 #include "clang/AST/Decl.h" 18 #include "clang/AST/DeclCXX.h" 19 #include "clang/AST/TypeOrdering.h" 20 #include "llvm/Support/FileSystem.h" 21 #include "llvm/Support/GraphWriter.h" 22 #include "llvm/Support/raw_ostream.h" 23 #include <map> 24 #include <set> 25 26 using namespace llvm; 27 28 namespace clang { 29 30 /// InheritanceHierarchyWriter - Helper class that writes out a 31 /// GraphViz file that diagrams the inheritance hierarchy starting at 32 /// a given C++ class type. Note that we do not use LLVM's 33 /// GraphWriter, because the interface does not permit us to properly 34 /// differentiate between uses of types as virtual bases 35 /// vs. non-virtual bases. 36 class InheritanceHierarchyWriter { 37 ASTContext& Context; 38 raw_ostream &Out; 39 std::map<QualType, int, QualTypeOrdering> DirectBaseCount; 40 std::set<QualType, QualTypeOrdering> KnownVirtualBases; 41 42 public: 43 InheritanceHierarchyWriter(ASTContext& Context, raw_ostream& Out) 44 : Context(Context), Out(Out) { } 45 46 void WriteGraph(QualType Type) { 47 Out << "digraph \"" << DOT::EscapeString(Type.getAsString()) << "\" {\n"; 48 WriteNode(Type, false); 49 Out << "}\n"; 50 } 51 52 protected: 53 /// WriteNode - Write out the description of node in the inheritance 54 /// diagram, which may be a base class or it may be the root node. 55 void WriteNode(QualType Type, bool FromVirtual); 56 57 /// WriteNodeReference - Write out a reference to the given node, 58 /// using a unique identifier for each direct base and for the 59 /// (only) virtual base. 60 raw_ostream& WriteNodeReference(QualType Type, bool FromVirtual); 61 }; 62 63 void InheritanceHierarchyWriter::WriteNode(QualType Type, bool FromVirtual) { 64 QualType CanonType = Context.getCanonicalType(Type); 65 66 if (FromVirtual) { 67 if (KnownVirtualBases.find(CanonType) != KnownVirtualBases.end()) 68 return; 69 70 // We haven't seen this virtual base before, so display it and 71 // its bases. 72 KnownVirtualBases.insert(CanonType); 73 } 74 75 // Declare the node itself. 76 Out << " "; 77 WriteNodeReference(Type, FromVirtual); 78 79 // Give the node a label based on the name of the class. 80 std::string TypeName = Type.getAsString(); 81 Out << " [ shape=\"box\", label=\"" << DOT::EscapeString(TypeName); 82 83 // If the name of the class was a typedef or something different 84 // from the "real" class name, show the real class name in 85 // parentheses so we don't confuse ourselves. 86 if (TypeName != CanonType.getAsString()) { 87 Out << "\\n(" << CanonType.getAsString() << ")"; 88 } 89 90 // Finished describing the node. 91 Out << " \"];\n"; 92 93 // Display the base classes. 94 const CXXRecordDecl *Decl 95 = static_cast<const CXXRecordDecl *>(Type->getAs<RecordType>()->getDecl()); 96 for (const auto &Base : Decl->bases()) { 97 QualType CanonBaseType = Context.getCanonicalType(Base.getType()); 98 99 // If this is not virtual inheritance, bump the direct base 100 // count for the type. 101 if (!Base.isVirtual()) 102 ++DirectBaseCount[CanonBaseType]; 103 104 // Write out the node (if we need to). 105 WriteNode(Base.getType(), Base.isVirtual()); 106 107 // Write out the edge. 108 Out << " "; 109 WriteNodeReference(Type, FromVirtual); 110 Out << " -> "; 111 WriteNodeReference(Base.getType(), Base.isVirtual()); 112 113 // Write out edge attributes to show the kind of inheritance. 114 if (Base.isVirtual()) { 115 Out << " [ style=\"dashed\" ]"; 116 } 117 Out << ";"; 118 } 119 } 120 121 /// WriteNodeReference - Write out a reference to the given node, 122 /// using a unique identifier for each direct base and for the 123 /// (only) virtual base. 124 raw_ostream& 125 InheritanceHierarchyWriter::WriteNodeReference(QualType Type, 126 bool FromVirtual) { 127 QualType CanonType = Context.getCanonicalType(Type); 128 129 Out << "Class_" << CanonType.getAsOpaquePtr(); 130 if (!FromVirtual) 131 Out << "_" << DirectBaseCount[CanonType]; 132 return Out; 133 } 134 135 /// viewInheritance - Display the inheritance hierarchy of this C++ 136 /// class using GraphViz. 137 void CXXRecordDecl::viewInheritance(ASTContext& Context) const { 138 QualType Self = Context.getTypeDeclType(this); 139 140 int FD; 141 SmallString<128> Filename; 142 std::error_code EC = 143 sys::fs::createTemporaryFile(Self.getAsString(), "dot", FD, Filename); 144 if (EC) { 145 llvm::errs() << "Error: " << EC.message() << "\n"; 146 return; 147 } 148 149 llvm::errs() << "Writing '" << Filename << "'... "; 150 151 llvm::raw_fd_ostream O(FD, true); 152 153 InheritanceHierarchyWriter Writer(Context, O); 154 Writer.WriteGraph(Self); 155 llvm::errs() << " done. \n"; 156 157 O.close(); 158 159 // Display the graph 160 DisplayGraph(Filename); 161 } 162 163 } 164
