1 //===- DeclFriend.cpp - C++ Friend Declaration AST Node Implementation ----===//
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 file implements the AST classes related to C++ friend
10 // declarations.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/AST/DeclFriend.h"
15 #include "clang/AST/Decl.h"
16 #include "clang/AST/DeclBase.h"
17 #include "clang/AST/DeclCXX.h"
18 #include "clang/AST/ASTContext.h"
19 #include "clang/AST/DeclTemplate.h"
20 #include "clang/Basic/LLVM.h"
21 #include "llvm/Support/Casting.h"
22 #include <cassert>
23 #include <cstddef>
24 
25 using namespace clang;
26 
27 void FriendDecl::anchor() {}
28 
29 FriendDecl *FriendDecl::getNextFriendSlowCase() {
30   return cast_or_null<FriendDecl>(
31                            NextFriend.get(getASTContext().getExternalSource()));
32 }
33 
34 FriendDecl *FriendDecl::Create(ASTContext &C, DeclContext *DC,
35                                SourceLocation L,
36                                FriendUnion Friend,
37                                SourceLocation FriendL,
38                           ArrayRef<TemplateParameterList *> FriendTypeTPLists) {
39 #ifndef NDEBUG
40   if (Friend.is<NamedDecl *>()) {
41     const auto *D = Friend.get<NamedDecl*>();
42     assert(isa<FunctionDecl>(D) ||
43            isa<CXXRecordDecl>(D) ||
44            isa<FunctionTemplateDecl>(D) ||
45            isa<ClassTemplateDecl>(D));
46 
47     // As a temporary hack, we permit template instantiation to point
48     // to the original declaration when instantiating members.
49     assert(D->getFriendObjectKind() ||
50            (cast<CXXRecordDecl>(DC)->getTemplateSpecializationKind()));
51     // These template parameters are for friend types only.
52     assert(FriendTypeTPLists.empty());
53   }
54 #endif
55 
56   std::size_t Extra =
57       FriendDecl::additionalSizeToAlloc<TemplateParameterList *>(
58           FriendTypeTPLists.size());
59   auto *FD = new (C, DC, Extra) FriendDecl(DC, L, Friend, FriendL,
60                                            FriendTypeTPLists);
61   cast<CXXRecordDecl>(DC)->pushFriendDecl(FD);
62   return FD;
63 }
64 
65 FriendDecl *FriendDecl::CreateDeserialized(ASTContext &C, unsigned ID,
66                                            unsigned FriendTypeNumTPLists) {
67   std::size_t Extra =
68       additionalSizeToAlloc<TemplateParameterList *>(FriendTypeNumTPLists);
69   return new (C, ID, Extra) FriendDecl(EmptyShell(), FriendTypeNumTPLists);
70 }
71 
72 FriendDecl *CXXRecordDecl::getFirstFriend() const {
73   ExternalASTSource *Source = getParentASTContext().getExternalSource();
74   Decl *First = data().FirstFriend.get(Source);
75   return First ? cast<FriendDecl>(First) : nullptr;
76 }
77