IRGen: Refactor LocalTypeData a bit

The "abstract conformance is just a ProtocolDecl" assumption is pretty
fundamental here, so we have to fudge a bit at the API boundary for now.

Eventually, LocalTypeDataKind should just contain a ProtocolConformanceRef
instead of duplicating the representation, however this would require
fixing various calls to LocalTypeDataKind::forAbstractProtocolWitnessTable()
which pass in a ProtocolDecl to pass in a ProtocolConformanceRef instead.

Author: slavapestov

lib/IRGen/GenProto.cpp

@@ -3402,8 +3402,7 @@ MetadataResponse MetadataPath::followComponent(IRGenFunction &IGF,
   }
 
   case Component::Kind::OutOfLineBaseProtocol: {
-    auto conformance = sourceKey.Kind.getProtocolConformance();
-    auto protocol = conformance.getRequirement();
+    auto protocol = sourceKey.Kind.getConformedProtocol();
     auto &pi = IGF.IGM.getProtocolInfo(protocol,
                                        ProtocolInfoKind::RequirementSignature);
 
@@ -3413,9 +3412,10 @@ MetadataResponse MetadataPath::followComponent(IRGenFunction &IGF,
 
     sourceKey.Kind =
       LocalTypeDataKind::forAbstractProtocolWitnessTable(inheritedProtocol);
-    if (conformance.isConcrete()) {
+    if (sourceKey.Kind.isConcreteProtocolConformance()) {
       auto inheritedConformance =
-        conformance.getConcrete()->getInheritedConformance(inheritedProtocol);
+        sourceKey.Kind.getConcreteProtocolConformance()
+          ->getInheritedConformance(inheritedProtocol);
       if (inheritedConformance) {
         sourceKey.Kind = LocalTypeDataKind::forConcreteProtocolWitnessTable(
                                                           inheritedConformance);
@@ -3438,8 +3438,8 @@ MetadataResponse MetadataPath::followComponent(IRGenFunction &IGF,
 
   case Component::Kind::AssociatedConformance: {
     auto sourceType = sourceKey.Type;
-    auto sourceConformance = sourceKey.Kind.getProtocolConformance();
-    auto sourceProtocol = sourceConformance.getRequirement();
+    auto sourceConformance = sourceKey.Kind.getProtocolConformance(sourceType);
+    auto sourceProtocol = sourceKey.Kind.getConformedProtocol();
     auto &pi = IGF.IGM.getProtocolInfo(sourceProtocol,
                                        ProtocolInfoKind::RequirementSignature);
 
@@ -3473,7 +3473,8 @@ MetadataResponse MetadataPath::followComponent(IRGenFunction &IGF,
       // In Embedded Swift associated-conformance entries simply point to the witness table
       // of the associated conformance.
       llvm::Value *sourceWTable = source.getMetadata();
-      llvm::Value *associatedWTable = emitAssociatedConformanceValue(IGF, sourceWTable, associatedConformanceRef);
+      llvm::Value *associatedWTable = emitAssociatedConformanceValue(
+          IGF, sourceWTable, associatedConformanceRef);
       return MetadataResponse::forComplete(associatedWTable);
     }
 
@@ -3562,13 +3563,13 @@ MetadataResponse MetadataPath::followComponent(IRGenFunction &IGF,
   }
 
   case Component::Kind::ConditionalConformance: {
-    auto sourceConformance = sourceKey.Kind.getProtocolConformance();
+    auto sourceConformance = sourceKey.Kind.getConcreteProtocolConformance();
 
     auto reqtIndex = component.getPrimaryIndex();
 
     ProtocolDecl *conformingProto;
     auto found = SILWitnessTable::enumerateWitnessTableConditionalConformances(
-        sourceConformance.getConcrete(),
+        sourceConformance,
         [&](unsigned index, CanType type, ProtocolDecl *proto) {
           if (reqtIndex == index) {
             conformingProto = proto;

lib/IRGen/LocalTypeDataKind.h

@@ -19,6 +19,8 @@
 #ifndef SWIFT_IRGEN_LOCALTYPEDATAKIND_H
 #define SWIFT_IRGEN_LOCALTYPEDATAKIND_H
 
+#include "swift/AST/PackConformance.h"
+#include "swift/AST/ProtocolConformance.h"
 #include "swift/AST/ProtocolConformanceRef.h"
 #include "swift/AST/Type.h"
 #include "swift/IRGen/ValueWitness.h"
@@ -183,13 +185,23 @@ class LocalTypeDataKind {
     return reinterpret_cast<PackConformance*>(Value - Kind_PackConformance);
   }
 
-  ProtocolConformanceRef getProtocolConformance() const {
+  ProtocolDecl *getConformedProtocol() const {
+    assert(!isSingletonKind());
+    if ((Value & KindMask) == Kind_Decl) {
+      return getAbstractProtocolConformance();
+    } else if ((Value & KindMask) == Kind_PackConformance) {
+      return getPackProtocolConformance()->getProtocol();
+    } else {
+      assert((Value & KindMask) == Kind_Conformance);
+      return getConcreteProtocolConformance()->getProtocol();
+    }
+  }
+
+  ProtocolConformanceRef getProtocolConformance(Type conformingType) const {
     assert(!isSingletonKind());
     if ((Value & KindMask) == Kind_Decl) {
-      // FIXME: Passing an empty Type() here temporarily while staging in
-      // new representation for abstract conformances
       return ProtocolConformanceRef::forAbstract(
-          Type(), getAbstractProtocolConformance());
+          conformingType, getAbstractProtocolConformance());
     } else if ((Value & KindMask) == Kind_PackConformance) {
       return ProtocolConformanceRef(getPackProtocolConformance());
     } else {