C++ support for Objective-C lightweight generics.

Teach C++'s tentative parsing to handle specializations of Objective-C
class types (e.g., NSArray<NSString *>) as well as Objective-C
protocol qualifiers (id<NSCopying>) by extending type-annotation
tokens to handle this case. As part of this, remove Objective-C
protocol qualifiers from the declaration specifiers, which never
really made sense: instead, provide Sema entry points to make them
part of the type annotation token. Among other things, this properly
diagnoses bogus types such as "<NSCopying> id" which should have been
written as "id <NSCopying>".

Implements template instantiation support for, e.g., NSArray<T>*
in C++. Note that parameterized classes are not templates in the C++
sense, so that cannot (for example) be used as a template argument for
a template template parameter. Part of rdar://problem/6294649.

llvm-svn: 241545

1 files changed, 48 insertions, 7 deletions

diff --git a/clang/lib/Parse/Parser.cpp b/clang/lib/Parse/Parser.cpp
index e32df95..e76f767 100644
--- a/clang/lib/Parse/Parser.cpp
+++ b/clang/lib/Parse/Parser.cpp
@@ -1413,14 +1413,35 @@ Parser::TryAnnotateName(bool IsAddressOfOperand,
     // It's not something we know about. Leave it unannotated.
     break;
 
-  case Sema::NC_Type:
-    Tok.setKind(tok::annot_typename);
-    setTypeAnnotation(Tok, Classification.getType());
-    Tok.setAnnotationEndLoc(NameLoc);
+  case Sema::NC_Type: {
+    SourceLocation BeginLoc = NameLoc;
     if (SS.isNotEmpty())
-      Tok.setLocation(SS.getBeginLoc());
+      BeginLoc = SS.getBeginLoc();
+
+    /// An Objective-C object type followed by '<' is a specialization of
+    /// a parameterized class type or a protocol-qualified type.
+    ParsedType Ty = Classification.getType();
+    if (getLangOpts().ObjC1 && NextToken().is(tok::less) &&
+        (Ty.get()->isObjCObjectType() ||
+         Ty.get()->isObjCObjectPointerType())) {
+      // Consume the name.
+      SourceLocation IdentifierLoc = ConsumeToken();
+      SourceLocation NewEndLoc;
+      TypeResult NewType
+          = parseObjCTypeArgsAndProtocolQualifiers(IdentifierLoc, Ty,
+                                                   /*consumeLastToken=*/false,
+                                                   NewEndLoc);
+      if (NewType.isUsable())
+        Ty = NewType.get();
+    }
+
+    Tok.setKind(tok::annot_typename);
+    setTypeAnnotation(Tok, Ty);
+    Tok.setAnnotationEndLoc(Tok.getLocation());
+    Tok.setLocation(BeginLoc);
     PP.AnnotateCachedTokens(Tok);
     return ANK_Success;
+  }
 
   case Sema::NC_Expression:
     Tok.setKind(tok::annot_primary_expr);
@@ -1627,13 +1648,33 @@ bool Parser::TryAnnotateTypeOrScopeTokenAfterScopeSpec(bool EnteringContext,
       // A FixIt was applied as a result of typo correction
       if (CorrectedII)
         Tok.setIdentifierInfo(CorrectedII);
+
+      SourceLocation BeginLoc = Tok.getLocation();
+      if (SS.isNotEmpty()) // it was a C++ qualified type name.
+        BeginLoc = SS.getBeginLoc();
+
+      /// An Objective-C object type followed by '<' is a specialization of
+      /// a parameterized class type or a protocol-qualified type.
+      if (getLangOpts().ObjC1 && NextToken().is(tok::less) &&
+          (Ty.get()->isObjCObjectType() ||
+           Ty.get()->isObjCObjectPointerType())) {
+        // Consume the name.
+        SourceLocation IdentifierLoc = ConsumeToken();
+        SourceLocation NewEndLoc;
+        TypeResult NewType
+          = parseObjCTypeArgsAndProtocolQualifiers(IdentifierLoc, Ty,
+                                                   /*consumeLastToken=*/false,
+                                                   NewEndLoc);
+        if (NewType.isUsable())
+          Ty = NewType.get();
+      }
+
       // This is a typename. Replace the current token in-place with an
       // annotation type token.
       Tok.setKind(tok::annot_typename);
       setTypeAnnotation(Tok, Ty);
       Tok.setAnnotationEndLoc(Tok.getLocation());
-      if (SS.isNotEmpty()) // it was a C++ qualified type name.
-        Tok.setLocation(SS.getBeginLoc());
+      Tok.setLocation(BeginLoc);
 
       // In case the tokens were cached, have Preprocessor replace
       // them with the annotation token.