1 //===- DeclFriend.cpp - C++ Friend Declaration AST Node Implementation ----===//
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 the AST classes related to C++ friend
11 // declarations.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "clang/AST/DeclFriend.h"
16 #include "clang/AST/Decl.h"
17 #include "clang/AST/DeclBase.h"
18 #include "clang/AST/DeclCXX.h"
19 #include "clang/AST/ASTContext.h"
20 #include "clang/AST/DeclTemplate.h"
21 #include "clang/Basic/LLVM.h"
22 #include "llvm/Support/Casting.h"
23 #include <cassert>
24 #include <cstddef>
25 
26 using namespace clang;
27 
28 void FriendDecl::anchor() {}
29 
30 FriendDecl *FriendDecl::getNextFriendSlowCase() {
31   return cast_or_null<FriendDecl>(
32                            NextFriend.get(getASTContext().getExternalSource()));
33 }
34 
35 FriendDecl *FriendDecl::Create(ASTContext &C, DeclContext *DC,
36                                SourceLocation L,
37                                FriendUnion Friend,
38                                SourceLocation FriendL,
39                           ArrayRef<TemplateParameterList *> FriendTypeTPLists) {
40 #ifndef NDEBUG
41   if (Friend.is<NamedDecl *>()) {
42     const auto *D = Friend.get<NamedDecl*>();
43     assert(isa<FunctionDecl>(D) ||
44            isa<CXXRecordDecl>(D) ||
45            isa<FunctionTemplateDecl>(D) ||
46            isa<ClassTemplateDecl>(D));
47 
48     // As a temporary hack, we permit template instantiation to point
49     // to the original declaration when instantiating members.
50     assert(D->getFriendObjectKind() ||
51            (cast<CXXRecordDecl>(DC)->getTemplateSpecializationKind()));
52     // These template parameters are for friend types only.
53     assert(FriendTypeTPLists.empty());
54   }
55 #endif
56 
57   std::size_t Extra =
58       FriendDecl::additionalSizeToAlloc<TemplateParameterList *>(
59           FriendTypeTPLists.size());
60   auto *FD = new (C, DC, Extra) FriendDecl(DC, L, Friend, FriendL,
61                                            FriendTypeTPLists);
62   cast<CXXRecordDecl>(DC)->pushFriendDecl(FD);
63   return FD;
64 }
65 
66 FriendDecl *FriendDecl::CreateDeserialized(ASTContext &C, unsigned ID,
67                                            unsigned FriendTypeNumTPLists) {
68   std::size_t Extra =
69       additionalSizeToAlloc<TemplateParameterList *>(FriendTypeNumTPLists);
70   return new (C, ID, Extra) FriendDecl(EmptyShell(), FriendTypeNumTPLists);
71 }
72 
73 FriendDecl *CXXRecordDecl::getFirstFriend() const {
74   ExternalASTSource *Source = getParentASTContext().getExternalSource();
75   Decl *First = data().FirstFriend.get(Source);
76   return First ? cast<FriendDecl>(First) : nullptr;
77 }
78