P0091R3: Implement basic parsing support for C++17 deduction-guides.

We model deduction-guides as functions with a new kind of name that identifies
the template whose deduction they guide; the bulk of this patch is adding the
new name kind. This gives us a clean way to attach an extensible list of guides
to a class template in a way that doesn't require any special handling in AST
files etc (and we're going to need these functions we come to performing
deduction).

llvm-svn: 294266

1 files changed, 9 insertions, 0 deletions

diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index f80ce35df2b..9ded89413e8 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -2264,6 +2264,7 @@ ASTNodeImporter::ImportDeclarationNameLoc(const DeclarationNameInfo &From,
   case DeclarationName::ObjCOneArgSelector:
   case DeclarationName::ObjCMultiArgSelector:
   case DeclarationName::CXXUsingDirective:
+  case DeclarationName::CXXDeductionGuideName:
     return;
 
   case DeclarationName::CXXOperatorName: {
@@ -7448,6 +7449,14 @@ DeclarationName ASTImporter::Import(DeclarationName FromName) {
                                                ToContext.getCanonicalType(T));
   }
 
+  case DeclarationName::CXXDeductionGuideName: {
+    TemplateDecl *Template = cast_or_null<TemplateDecl>(
+        Import(FromName.getCXXDeductionGuideTemplate()));
+    if (!Template)
+      return DeclarationName();
+    return ToContext.DeclarationNames.getCXXDeductionGuideName(Template);
+  }
+
   case DeclarationName::CXXConversionFunctionName: {
     QualType T = Import(FromName.getCXXNameType());
     if (T.isNull())