[clang] [clang-tools-extra] [Clang] support friend declarations with a dependent nested-name-specifier (PR #191268)

[Yanzuo Liu via cfe-commits]

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@@ -1832,36 +1832,41 @@ void ASTDeclWriter::VisitAccessSpecDecl(AccessSpecDecl *D) {
 }
 
 void ASTDeclWriter::VisitFriendDecl(FriendDecl *D) {
-  // Record the number of friend type template parameter lists here
-  // so as to simplify memory allocation during deserialization.
-  Record.push_back(D->NumTPLists);
   VisitDecl(D);
   bool hasFriendDecl = isa<NamedDecl *>(D->Friend);
   Record.push_back(hasFriendDecl);
   if (hasFriendDecl)
     Record.AddDeclRef(D->getFriendDecl());
   else
     Record.AddTypeSourceInfo(D->getFriendType());
-  for (unsigned i = 0; i < D->NumTPLists; ++i)
-    Record.AddTemplateParameterList(D->getFriendTypeTemplateParameterList(i));
   Record.AddDeclRef(D->getNextFriend());
-  Record.push_back(D->UnsupportedFriend);
   Record.AddSourceLocation(D->FriendLoc);
   Record.AddSourceLocation(D->EllipsisLoc);
   Code = serialization::DECL_FRIEND;
 }
 
 void ASTDeclWriter::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
+  // Record the number of friend type template parameter lists here
+  // so as to simplify memory allocation during deserialization.
+  Record.push_back(D->NumTPLists);
   VisitDecl(D);
-  Record.push_back(D->getNumTemplateParameters());
-  for (unsigned i = 0, e = D->getNumTemplateParameters(); i != e; ++i)
-    Record.AddTemplateParameterList(D->getTemplateParameterList(i));
-  Record.push_back(D->getFriendDecl() != nullptr);
-  if (D->getFriendDecl())
-    Record.AddDeclRef(D->getFriendDecl());
-  else
-    Record.AddTypeSourceInfo(D->getFriendType());
-  Record.AddSourceLocation(D->getFriendLoc());
+  for (TemplateParameterList *TPL : D->getFriendTypeTemplateParameterLists())
+    Record.AddTemplateParameterList(TPL);
+  if (D->Template.isNull()) {
+    if (D->getFriendDecl()) {
+      Record.push_back(1);
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zwuis wrote:

Can we avoid magic numbers?

https://github.com/llvm/llvm-project/pull/191268