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 using namespace clang;
26
27 namespace {
28 /// InheritanceHierarchyWriter - Helper class that writes out a
29 /// GraphViz file that diagrams the inheritance hierarchy starting at
30 /// a given C++ class type. Note that we do not use LLVM's
31 /// GraphWriter, because the interface does not permit us to properly
32 /// differentiate between uses of types as virtual bases
33 /// vs. non-virtual bases.
34 class InheritanceHierarchyWriter {
35 ASTContext& Context;
36 raw_ostream &Out;
37 std::map<QualType, int, QualTypeOrdering> DirectBaseCount;
38 std::set<QualType, QualTypeOrdering> KnownVirtualBases;
39
40 public:
InheritanceHierarchyWriter(ASTContext & Context,raw_ostream & Out)41 InheritanceHierarchyWriter(ASTContext& Context, raw_ostream& Out)
42 : Context(Context), Out(Out) { }
43
WriteGraph(QualType Type)44 void WriteGraph(QualType Type) {
45 Out << "digraph \"" << llvm::DOT::EscapeString(Type.getAsString())
46 << "\" {\n";
47 WriteNode(Type, false);
48 Out << "}\n";
49 }
50
51 protected:
52 /// WriteNode - Write out the description of node in the inheritance
53 /// diagram, which may be a base class or it may be the root node.
54 void WriteNode(QualType Type, bool FromVirtual);
55
56 /// WriteNodeReference - Write out a reference to the given node,
57 /// using a unique identifier for each direct base and for the
58 /// (only) virtual base.
59 raw_ostream& WriteNodeReference(QualType Type, bool FromVirtual);
60 };
61 } // namespace
62
WriteNode(QualType Type,bool FromVirtual)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=\"" << llvm::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&
WriteNodeReference(QualType Type,bool FromVirtual)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.
viewInheritance(ASTContext & Context) const137 void CXXRecordDecl::viewInheritance(ASTContext& Context) const {
138 QualType Self = Context.getTypeDeclType(this);
139
140 int FD;
141 SmallString<128> Filename;
142 if (std::error_code EC = llvm::sys::fs::createTemporaryFile(
143 Self.getAsString(), "dot", FD, Filename)) {
144 llvm::errs() << "Error: " << EC.message() << "\n";
145 return;
146 }
147
148 llvm::errs() << "Writing '" << Filename << "'... ";
149
150 llvm::raw_fd_ostream O(FD, true);
151
152 InheritanceHierarchyWriter Writer(Context, O);
153 Writer.WriteGraph(Self);
154 llvm::errs() << " done. \n";
155
156 O.close();
157
158 // Display the graph
159 DisplayGraph(Filename);
160 }
161