InheritViz.cpp revision 355940
1238431Sdteske//===- InheritViz.cpp - Graphviz visualization for inheritance --*- C++ -*-===// 2222417Sjulian// 3222417Sjulian// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4222417Sjulian// See https://llvm.org/LICENSE.txt for license information. 5222417Sjulian// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6222417Sjulian// 7222417Sjulian//===----------------------------------------------------------------------===// 8222417Sjulian// 9222417Sjulian// This file implements CXXRecordDecl::viewInheritance, which 10222417Sjulian// generates a GraphViz DOT file that depicts the class inheritance 11222417Sjulian// diagram and then calls Graphviz/dot+gv on it. 12222417Sjulian// 13222417Sjulian//===----------------------------------------------------------------------===// 14222417Sjulian 15222417Sjulian#include "clang/AST/ASTContext.h" 16222417Sjulian#include "clang/AST/Decl.h" 17222417Sjulian#include "clang/AST/DeclCXX.h" 18222417Sjulian#include "clang/AST/TypeOrdering.h" 19222417Sjulian#include "llvm/Support/FileSystem.h" 20222417Sjulian#include "llvm/Support/GraphWriter.h" 21222417Sjulian#include "llvm/Support/raw_ostream.h" 22222417Sjulian#include <map> 23222417Sjulian#include <set> 24222417Sjulianusing namespace clang; 25222417Sjulian 26222417Sjuliannamespace { 27222417Sjulian/// InheritanceHierarchyWriter - Helper class that writes out a 28222417Sjulian/// GraphViz file that diagrams the inheritance hierarchy starting at 29222417Sjulian/// a given C++ class type. Note that we do not use LLVM's 30222417Sjulian/// GraphWriter, because the interface does not permit us to properly 31222417Sjulian/// differentiate between uses of types as virtual bases 32222417Sjulian/// vs. non-virtual bases. 33222417Sjulianclass InheritanceHierarchyWriter { 34222417Sjulian ASTContext& Context; 35222417Sjulian raw_ostream &Out; 36222417Sjulian std::map<QualType, int, QualTypeOrdering> DirectBaseCount; 37222417Sjulian std::set<QualType, QualTypeOrdering> KnownVirtualBases; 38222417Sjulian 39222417Sjulianpublic: 40222417Sjulian InheritanceHierarchyWriter(ASTContext& Context, raw_ostream& Out) 41222417Sjulian : Context(Context), Out(Out) { } 42222417Sjulian 43222417Sjulian void WriteGraph(QualType Type) { 44222417Sjulian Out << "digraph \"" << llvm::DOT::EscapeString(Type.getAsString()) 45222417Sjulian << "\" {\n"; 46222417Sjulian WriteNode(Type, false); 47222417Sjulian Out << "}\n"; 48222417Sjulian } 49222417Sjulian 50222417Sjulianprotected: 51222417Sjulian /// WriteNode - Write out the description of node in the inheritance 52222417Sjulian /// diagram, which may be a base class or it may be the root node. 53222417Sjulian void WriteNode(QualType Type, bool FromVirtual); 54222417Sjulian 55222417Sjulian /// WriteNodeReference - Write out a reference to the given node, 56222417Sjulian /// using a unique identifier for each direct base and for the 57222417Sjulian /// (only) virtual base. 58222417Sjulian raw_ostream& WriteNodeReference(QualType Type, bool FromVirtual); 59267010Srodrigc}; 60267010Srodrigc} // namespace 61222417Sjulian 62222417Sjulianvoid InheritanceHierarchyWriter::WriteNode(QualType Type, bool FromVirtual) { 63222417Sjulian QualType CanonType = Context.getCanonicalType(Type); 64222417Sjulian 65222417Sjulian if (FromVirtual) { 66222417Sjulian if (KnownVirtualBases.find(CanonType) != KnownVirtualBases.end()) 67222417Sjulian return; 68222417Sjulian 69222417Sjulian // We haven't seen this virtual base before, so display it and 70222417Sjulian // its bases. 71222417Sjulian KnownVirtualBases.insert(CanonType); 72222417Sjulian } 73222417Sjulian 74222417Sjulian // Declare the node itself. 75222417Sjulian Out << " "; 76222417Sjulian WriteNodeReference(Type, FromVirtual); 77222417Sjulian 78222417Sjulian // Give the node a label based on the name of the class. 79222417Sjulian std::string TypeName = Type.getAsString(); 80222417Sjulian Out << " [ shape=\"box\", label=\"" << llvm::DOT::EscapeString(TypeName); 81222417Sjulian 82222417Sjulian // If the name of the class was a typedef or something different 83222417Sjulian // from the "real" class name, show the real class name in 84222417Sjulian // parentheses so we don't confuse ourselves. 85222417Sjulian if (TypeName != CanonType.getAsString()) { 86222417Sjulian Out << "\\n(" << CanonType.getAsString() << ")"; 87222417Sjulian } 88222417Sjulian 89222417Sjulian // Finished describing the node. 90222417Sjulian Out << " \"];\n"; 91222417Sjulian 92267010Srodrigc // Display the base classes. 93267010Srodrigc const CXXRecordDecl *Decl 94267010Srodrigc = static_cast<const CXXRecordDecl *>(Type->getAs<RecordType>()->getDecl()); 95267010Srodrigc for (const auto &Base : Decl->bases()) { 96267010Srodrigc QualType CanonBaseType = Context.getCanonicalType(Base.getType()); 97267010Srodrigc 98267010Srodrigc // If this is not virtual inheritance, bump the direct base 99267010Srodrigc // count for the type. 100267010Srodrigc if (!Base.isVirtual()) 101222417Sjulian ++DirectBaseCount[CanonBaseType]; 102222417Sjulian 103 // Write out the node (if we need to). 104 WriteNode(Base.getType(), Base.isVirtual()); 105 106 // Write out the edge. 107 Out << " "; 108 WriteNodeReference(Type, FromVirtual); 109 Out << " -> "; 110 WriteNodeReference(Base.getType(), Base.isVirtual()); 111 112 // Write out edge attributes to show the kind of inheritance. 113 if (Base.isVirtual()) { 114 Out << " [ style=\"dashed\" ]"; 115 } 116 Out << ";"; 117 } 118} 119 120/// WriteNodeReference - Write out a reference to the given node, 121/// using a unique identifier for each direct base and for the 122/// (only) virtual base. 123raw_ostream& 124InheritanceHierarchyWriter::WriteNodeReference(QualType Type, 125 bool FromVirtual) { 126 QualType CanonType = Context.getCanonicalType(Type); 127 128 Out << "Class_" << CanonType.getAsOpaquePtr(); 129 if (!FromVirtual) 130 Out << "_" << DirectBaseCount[CanonType]; 131 return Out; 132} 133 134/// viewInheritance - Display the inheritance hierarchy of this C++ 135/// class using GraphViz. 136void CXXRecordDecl::viewInheritance(ASTContext& Context) const { 137 QualType Self = Context.getTypeDeclType(this); 138 139 int FD; 140 SmallString<128> Filename; 141 if (std::error_code EC = llvm::sys::fs::createTemporaryFile( 142 Self.getAsString(), "dot", FD, Filename)) { 143 llvm::errs() << "Error: " << EC.message() << "\n"; 144 return; 145 } 146 147 llvm::errs() << "Writing '" << Filename << "'... "; 148 149 llvm::raw_fd_ostream O(FD, true); 150 151 InheritanceHierarchyWriter Writer(Context, O); 152 Writer.WriteGraph(Self); 153 llvm::errs() << " done. \n"; 154 155 O.close(); 156 157 // Display the graph 158 DisplayGraph(Filename); 159} 160