Iterative type checker: compute inherited protocols of a protocol.

Introduce a type check request for computing inherited protocols and
start using it in a few places.

Swift SVN r32562

include/swift/Sema/IterativeTypeChecker.h

@@ -20,6 +20,7 @@
 #define SWIFT_SEMA_ITERATIVE_TYPE_CHECKER_H
 
 #include "swift/Sema/TypeCheckRequest.h"
+#include "swift/AST/DiagnosticEngine.h"
 #include "swift/Basic/LLVM.h"
 #include "llvm/ADT/STLExtras.h"
 
@@ -54,6 +55,15 @@ class IterativeTypeChecker {
 public:
   IterativeTypeChecker(TypeChecker &tc) : TC(tc) { }
 
+  ASTContext &getASTContext() const;
+
+  DiagnosticEngine &getDiags() const;
+
+  template<typename ...ArgTypes>
+  InFlightDiagnostic diagnose(ArgTypes &&...Args) {
+    return getDiags().diagnose(std::forward<ArgTypes>(Args)...);
+  }
+
   /// Determine whether the given request has already been satisfied.
   bool isSatisfied(TypeCheckRequest request);
 

include/swift/Sema/TypeCheckRequest.h

@@ -28,6 +28,7 @@ namespace swift {
 class ClassDecl;
 class EnumDecl;
 class ExtensionDecl;
+class ProtocolDecl;
 class TypeDecl;
 
 /// A request to the type checker to compute some particular kind of

include/swift/Sema/TypeCheckRequestKinds.def

@@ -37,6 +37,7 @@
 TYPE_CHECK_REQUEST_PAYLOAD(Class, ClassDecl *)
 TYPE_CHECK_REQUEST_PAYLOAD(Enum, EnumDecl *)
 TYPE_CHECK_REQUEST_PAYLOAD(InheritedClauseEntry, std::pair<llvm::PointerUnion<TypeDecl *, ExtensionDecl *>, unsigned>)
+TYPE_CHECK_REQUEST_PAYLOAD(Protocol, ProtocolDecl *)
 
 /// Perform type checking on an entry in the inherited clause of a
 /// type or extension.
@@ -48,5 +49,8 @@ TYPE_CHECK_REQUEST(TypeCheckSuperclass, Class)
 /// Perform type checking on the raw type of a particular enum.
 TYPE_CHECK_REQUEST(TypeCheckRawType, Enum)
 
+/// Compute the set of inherited protocols for a given protocl
+TYPE_CHECK_REQUEST(InheritedProtocols, Protocol)
+
 #undef TYPE_CHECK_REQUEST_PAYLOAD
 #undef TYPE_CHECK_REQUEST