7 files changed, 24 insertions, 0 deletions
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index d61ca589d5b..d51071440e7 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -1151,6 +1151,9 @@ void ASTContext::InitBuiltinTypes(const TargetInfo &Target,
 
   WIntTy = getFromTargetType(Target.getWIntType());
 
+  // C++20 (proposed)
+  InitBuiltinType(Char8Ty,              BuiltinType::Char8);
+
   if (LangOpts.CPlusPlus) // C++0x 3.9.1p5, extension for C++
     InitBuiltinType(Char16Ty,           BuiltinType::Char16);
   else // C99
@@ -1739,6 +1742,7 @@ TypeInfo ASTContext::getTypeInfoImpl(const Type *T) const {
     case BuiltinType::Char_U:
     case BuiltinType::UChar:
     case BuiltinType::SChar:
+    case BuiltinType::Char8:
       Width = Target->getCharWidth();
       Align = Target->getCharAlign();
       break;
@@ -5456,6 +5460,7 @@ QualType ASTContext::getPromotedIntegerType(QualType Promotable) const {
     // FIXME: Is there some better way to compute this?
     if (BT->getKind() == BuiltinType::WChar_S ||
         BT->getKind() == BuiltinType::WChar_U ||
+        BT->getKind() == BuiltinType::Char8 ||
         BT->getKind() == BuiltinType::Char16 ||
         BT->getKind() == BuiltinType::Char32) {
       bool FromIsSigned = BT->getKind() == BuiltinType::WChar_S;
@@ -6202,6 +6207,7 @@ static char getObjCEncodingForPrimitiveKind(const ASTContext *C,
     switch (kind) {
     case BuiltinType::Void:       return 'v';
     case BuiltinType::Bool:       return 'B';
+    case BuiltinType::Char8:
     case BuiltinType::Char_U:
     case BuiltinType::UChar:      return 'C';
     case BuiltinType::Char16:
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 81577248612..c540dfbbf07 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -7326,6 +7326,7 @@ static int EvaluateBuiltinClassifyType(const CallExpr *E,
       return pointer_type_class;
 
     case BuiltinType::WChar_U:
+    case BuiltinType::Char8:
     case BuiltinType::Char16:
     case BuiltinType::Char32:
     case BuiltinType::ObjCId:
diff --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp
index 609d0ebc849..610400d8322 100644
--- a/clang/lib/AST/ItaniumMangle.cpp
+++ b/clang/lib/AST/ItaniumMangle.cpp
@@ -2525,6 +2525,9 @@ void CXXNameMangler::mangleType(const BuiltinType *T) {
   case BuiltinType::WChar_U:
     Out << 'w';
     break;
+  case BuiltinType::Char8:
+    Out << "Du";
+    break;
   case BuiltinType::Char16:
     Out << "Ds";
     break;
diff --git a/clang/lib/AST/MicrosoftMangle.cpp b/clang/lib/AST/MicrosoftMangle.cpp
index 1039ae87ab6..e72804b2c3b 100644
--- a/clang/lib/AST/MicrosoftMangle.cpp
+++ b/clang/lib/AST/MicrosoftMangle.cpp
@@ -1918,6 +1918,7 @@ void MicrosoftCXXNameMangler::mangleType(const BuiltinType *T, Qualifiers,
     Out << "$$T";
     break;
 
+  case BuiltinType::Char8:
   case BuiltinType::Float16:
     mangleArtificalTagType(TTK_Struct, "_Float16", {"__clang"});
     break;
diff --git a/clang/lib/AST/NSAPI.cpp b/clang/lib/AST/NSAPI.cpp
index 8adaef1fb64..eb807f0cc53 100644
--- a/clang/lib/AST/NSAPI.cpp
+++ b/clang/lib/AST/NSAPI.cpp
@@ -436,6 +436,7 @@ NSAPI::getNSNumberFactoryMethodKind(QualType T) const {
   case BuiltinType::Void:
   case BuiltinType::WChar_U:
   case BuiltinType::WChar_S:
+  case BuiltinType::Char8:
   case BuiltinType::Char16:
   case BuiltinType::Char32:
   case BuiltinType::Int128:
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index a2a60772b77..571dc2abfa0 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -1763,6 +1763,12 @@ bool Type::isWideCharType() const {
   return false;
 }
 
+bool Type::isChar8Type() const {
+  if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
+    return BT->getKind() == BuiltinType::Char8;
+  return false;
+}
+
 bool Type::isChar16Type() const {
   if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType))
     return BT->getKind() == BuiltinType::Char16;
@@ -1785,6 +1791,7 @@ bool Type::isAnyCharacterType() const {
   case BuiltinType::Char_U:
   case BuiltinType::UChar:
   case BuiltinType::WChar_U:
+  case BuiltinType::Char8:
   case BuiltinType::Char16:
   case BuiltinType::Char32:
   case BuiltinType::Char_S:
@@ -2419,6 +2426,7 @@ bool Type::isPromotableIntegerType() const {
     case BuiltinType::UShort:
     case BuiltinType::WChar_S:
     case BuiltinType::WChar_U:
+    case BuiltinType::Char8:
     case BuiltinType::Char16:
     case BuiltinType::Char32:
       return true;
@@ -2655,6 +2663,8 @@ StringRef BuiltinType::getName(const PrintingPolicy &Policy) const {
   case WChar_S:
   case WChar_U:
     return Policy.MSWChar ? "__wchar_t" : "wchar_t";
+  case Char8:
+    return "char8_t";
   case Char16:
     return "char16_t";
   case Char32:
diff --git a/clang/lib/AST/TypeLoc.cpp b/clang/lib/AST/TypeLoc.cpp
index 0ac50b31ace..57349b46f54 100644
--- a/clang/lib/AST/TypeLoc.cpp
+++ b/clang/lib/AST/TypeLoc.cpp
@@ -317,6 +317,8 @@ TypeSpecifierType BuiltinTypeLoc::getWrittenTypeSpec() const {
   case BuiltinType::Char_U:
   case BuiltinType::Char_S:
     return TST_char;
+  case BuiltinType::Char8:
+    return TST_char8;
   case BuiltinType::Char16:
     return TST_char16;
   case BuiltinType::Char32: