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, 12 insertions, 4 deletions

diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index da8e5ff6b90..67c7e460997 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -944,6 +944,10 @@ DeclarationNameKey::DeclarationNameKey(DeclarationName Name)
   case DeclarationName::CXXLiteralOperatorName:
     Data = (uint64_t)Name.getCXXLiteralIdentifier();
     break;
+  case DeclarationName::CXXDeductionGuideName:
+    Data = (uint64_t)Name.getCXXDeductionGuideTemplate()
+               ->getDeclName().getAsIdentifierInfo();
+    break;
   case DeclarationName::CXXConstructorName:
   case DeclarationName::CXXDestructorName:
   case DeclarationName::CXXConversionFunctionName:
@@ -960,6 +964,7 @@ unsigned DeclarationNameKey::getHash() const {
   switch (Kind) {
   case DeclarationName::Identifier:
   case DeclarationName::CXXLiteralOperatorName:
+  case DeclarationName::CXXDeductionGuideName:
     ID.AddString(((IdentifierInfo*)Data)->getName());
     break;
   case DeclarationName::ObjCZeroArgSelector:
@@ -1003,6 +1008,8 @@ ASTDeclContextNameLookupTrait::ReadKey(const unsigned char *d, unsigned) {
   uint64_t Data;
   switch (Kind) {
   case DeclarationName::Identifier:
+  case DeclarationName::CXXLiteralOperatorName:
+  case DeclarationName::CXXDeductionGuideName:
     Data = (uint64_t)Reader.getLocalIdentifier(
         F, endian::readNext<uint32_t, little, unaligned>(d));
     break;
@@ -1017,10 +1024,6 @@ ASTDeclContextNameLookupTrait::ReadKey(const unsigned char *d, unsigned) {
   case DeclarationName::CXXOperatorName:
     Data = *d++; // OverloadedOperatorKind
     break;
-  case DeclarationName::CXXLiteralOperatorName:
-    Data = (uint64_t)Reader.getLocalIdentifier(
-        F, endian::readNext<uint32_t, little, unaligned>(d));
-    break;
   case DeclarationName::CXXConstructorName:
   case DeclarationName::CXXDestructorName:
   case DeclarationName::CXXConversionFunctionName:
@@ -7992,6 +7995,10 @@ ASTReader::ReadDeclarationName(ModuleFile &F,
     return Context.DeclarationNames.getCXXDestructorName(
                           Context.getCanonicalType(readType(F, Record, Idx)));
 
+  case DeclarationName::CXXDeductionGuideName:
+    return Context.DeclarationNames.getCXXDeductionGuideName(
+                          ReadDeclAs<TemplateDecl>(F, Record, Idx));
+
   case DeclarationName::CXXConversionFunctionName:
     return Context.DeclarationNames.getCXXConversionFunctionName(
                           Context.getCanonicalType(readType(F, Record, Idx)));
@@ -8039,6 +8046,7 @@ void ASTReader::ReadDeclarationNameLoc(ModuleFile &F,
   case DeclarationName::ObjCOneArgSelector:
   case DeclarationName::ObjCMultiArgSelector:
   case DeclarationName::CXXUsingDirective:
+  case DeclarationName::CXXDeductionGuideName:
     break;
   }
 }