| //===- InheritViz.cpp - Graphviz visualization for inheritance --*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements CXXRecordDecl::viewInheritance, which |
| // generates a GraphViz DOT file that depicts the class inheritance |
| // diagram and then calls Graphviz/dot+gv on it. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/Decl.h" |
| #include "clang/AST/DeclCXX.h" |
| #include "clang/AST/TypeOrdering.h" |
| #include "llvm/Support/FileSystem.h" |
| #include "llvm/Support/GraphWriter.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include <map> |
| #include <set> |
| using namespace clang; |
| |
| namespace { |
| /// InheritanceHierarchyWriter - Helper class that writes out a |
| /// GraphViz file that diagrams the inheritance hierarchy starting at |
| /// a given C++ class type. Note that we do not use LLVM's |
| /// GraphWriter, because the interface does not permit us to properly |
| /// differentiate between uses of types as virtual bases |
| /// vs. non-virtual bases. |
| class InheritanceHierarchyWriter { |
| ASTContext& Context; |
| raw_ostream &Out; |
| std::map<QualType, int, QualTypeOrdering> DirectBaseCount; |
| std::set<QualType, QualTypeOrdering> KnownVirtualBases; |
| |
| public: |
| InheritanceHierarchyWriter(ASTContext& Context, raw_ostream& Out) |
| : Context(Context), Out(Out) { } |
| |
| void WriteGraph(QualType Type) { |
| Out << "digraph \"" << llvm::DOT::EscapeString(Type.getAsString()) |
| << "\" {\n"; |
| WriteNode(Type, false); |
| Out << "}\n"; |
| } |
| |
| protected: |
| /// WriteNode - Write out the description of node in the inheritance |
| /// diagram, which may be a base class or it may be the root node. |
| void WriteNode(QualType Type, bool FromVirtual); |
| |
| /// WriteNodeReference - Write out a reference to the given node, |
| /// using a unique identifier for each direct base and for the |
| /// (only) virtual base. |
| raw_ostream& WriteNodeReference(QualType Type, bool FromVirtual); |
| }; |
| } // namespace |
| |
| void InheritanceHierarchyWriter::WriteNode(QualType Type, bool FromVirtual) { |
| QualType CanonType = Context.getCanonicalType(Type); |
| |
| if (FromVirtual) { |
| if (KnownVirtualBases.find(CanonType) != KnownVirtualBases.end()) |
| return; |
| |
| // We haven't seen this virtual base before, so display it and |
| // its bases. |
| KnownVirtualBases.insert(CanonType); |
| } |
| |
| // Declare the node itself. |
| Out << " "; |
| WriteNodeReference(Type, FromVirtual); |
| |
| // Give the node a label based on the name of the class. |
| std::string TypeName = Type.getAsString(); |
| Out << " [ shape=\"box\", label=\"" << llvm::DOT::EscapeString(TypeName); |
| |
| // If the name of the class was a typedef or something different |
| // from the "real" class name, show the real class name in |
| // parentheses so we don't confuse ourselves. |
| if (TypeName != CanonType.getAsString()) { |
| Out << "\\n(" << CanonType.getAsString() << ")"; |
| } |
| |
| // Finished describing the node. |
| Out << " \"];\n"; |
| |
| // Display the base classes. |
| const auto *Decl = |
| static_cast<const CXXRecordDecl *>(Type->castAs<RecordType>()->getDecl()); |
| for (const auto &Base : Decl->bases()) { |
| QualType CanonBaseType = Context.getCanonicalType(Base.getType()); |
| |
| // If this is not virtual inheritance, bump the direct base |
| // count for the type. |
| if (!Base.isVirtual()) |
| ++DirectBaseCount[CanonBaseType]; |
| |
| // Write out the node (if we need to). |
| WriteNode(Base.getType(), Base.isVirtual()); |
| |
| // Write out the edge. |
| Out << " "; |
| WriteNodeReference(Type, FromVirtual); |
| Out << " -> "; |
| WriteNodeReference(Base.getType(), Base.isVirtual()); |
| |
| // Write out edge attributes to show the kind of inheritance. |
| if (Base.isVirtual()) { |
| Out << " [ style=\"dashed\" ]"; |
| } |
| Out << ";"; |
| } |
| } |
| |
| /// WriteNodeReference - Write out a reference to the given node, |
| /// using a unique identifier for each direct base and for the |
| /// (only) virtual base. |
| raw_ostream& |
| InheritanceHierarchyWriter::WriteNodeReference(QualType Type, |
| bool FromVirtual) { |
| QualType CanonType = Context.getCanonicalType(Type); |
| |
| Out << "Class_" << CanonType.getAsOpaquePtr(); |
| if (!FromVirtual) |
| Out << "_" << DirectBaseCount[CanonType]; |
| return Out; |
| } |
| |
| /// viewInheritance - Display the inheritance hierarchy of this C++ |
| /// class using GraphViz. |
| void CXXRecordDecl::viewInheritance(ASTContext& Context) const { |
| QualType Self = Context.getTypeDeclType(this); |
| |
| int FD; |
| SmallString<128> Filename; |
| if (std::error_code EC = llvm::sys::fs::createTemporaryFile( |
| Self.getAsString(), "dot", FD, Filename)) { |
| llvm::errs() << "Error: " << EC.message() << "\n"; |
| return; |
| } |
| |
| llvm::errs() << "Writing '" << Filename << "'... "; |
| |
| llvm::raw_fd_ostream O(FD, true); |
| |
| InheritanceHierarchyWriter Writer(Context, O); |
| Writer.WriteGraph(Self); |
| llvm::errs() << " done. \n"; |
| |
| O.close(); |
| |
| // Display the graph |
| DisplayGraph(Filename); |
| } |