1 //===----- CXXABI.h - Interface to C++ ABIs ---------------------*- C++ -*-===//
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 provides an abstract class for C++ AST support. Concrete
10 // subclasses of this implement AST support for specific C++ ABIs.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_CLANG_LIB_AST_CXXABI_H
15 #define LLVM_CLANG_LIB_AST_CXXABI_H
16 
17 #include "clang/AST/Type.h"
18 
19 namespace clang {
20 
21 class ASTContext;
22 class CXXConstructorDecl;
23 class DeclaratorDecl;
24 class Expr;
25 class MangleContext;
26 class MangleNumberingContext;
27 class MemberPointerType;
28 
29 /// Implements C++ ABI-specific semantic analysis functions.
30 class CXXABI {
31 public:
32   virtual ~CXXABI();
33 
34   struct MemberPointerInfo {
35     uint64_t Width;
36     unsigned Align;
37     bool HasPadding;
38   };
39 
40   /// Returns the width and alignment of a member pointer in bits, as well as
41   /// whether it has padding.
42   virtual MemberPointerInfo
43   getMemberPointerInfo(const MemberPointerType *MPT) const = 0;
44 
45   /// Returns the default calling convention for C++ methods.
46   virtual CallingConv getDefaultMethodCallConv(bool isVariadic) const = 0;
47 
48   /// Returns whether the given class is nearly empty, with just virtual
49   /// pointers and no data except possibly virtual bases.
50   virtual bool isNearlyEmpty(const CXXRecordDecl *RD) const = 0;
51 
52   /// Returns a new mangling number context for this C++ ABI.
53   virtual std::unique_ptr<MangleNumberingContext>
54   createMangleNumberingContext() const = 0;
55 
56   /// Adds a mapping from class to copy constructor for this C++ ABI.
57   virtual void addCopyConstructorForExceptionObject(CXXRecordDecl *,
58                                                     CXXConstructorDecl *) = 0;
59 
60   /// Retrieves the mapping from class to copy constructor for this C++ ABI.
61   virtual const CXXConstructorDecl *
62   getCopyConstructorForExceptionObject(CXXRecordDecl *) = 0;
63 
64   virtual void addTypedefNameForUnnamedTagDecl(TagDecl *TD,
65                                                TypedefNameDecl *DD) = 0;
66 
67   virtual TypedefNameDecl *
68   getTypedefNameForUnnamedTagDecl(const TagDecl *TD) = 0;
69 
70   virtual void addDeclaratorForUnnamedTagDecl(TagDecl *TD,
71                                               DeclaratorDecl *DD) = 0;
72 
73   virtual DeclaratorDecl *getDeclaratorForUnnamedTagDecl(const TagDecl *TD) = 0;
74 };
75 
76 /// Creates an instance of a C++ ABI class.
77 CXXABI *CreateItaniumCXXABI(ASTContext &Ctx);
78 CXXABI *CreateMicrosoftCXXABI(ASTContext &Ctx);
79 std::unique_ptr<MangleNumberingContext>
80 createItaniumNumberingContext(MangleContext *);
81 }
82 
83 #endif
84