[IRGen] Lowered open_pack_element.

include/swift/IRGen/GenericRequirement.h

@@ -15,11 +15,19 @@
 
 #include "swift/AST/Decl.h"
 #include "swift/AST/Type.h"
+#include "swift/AST/Types.h"
 #include "llvm/Support/raw_ostream.h"
 
+namespace llvm {
+class Type;
+}
+
 namespace swift {
 
 class ProtocolDecl;
+namespace irgen {
+class IRGenModule;
+}
 
 /// The three kinds of entities passed in the runtime calling convention for
 /// generic code: pack shapes, type metadata, and witness tables.
@@ -34,10 +42,12 @@ class ProtocolDecl;
 /// generic signature.
 class GenericRequirement {
 public:
-  enum class Kind: uint8_t {
+  enum class Kind : uint8_t {
     Shape,
     Metadata,
-    WitnessTable
+    WitnessTable,
+    MetadataPack,
+    WitnessTablePack,
   };
 
 private:
@@ -48,6 +58,16 @@ class GenericRequirement {
   GenericRequirement(Kind kind, CanType type, ProtocolDecl *proto)
     : kind(kind), type(type), proto(proto) {}
 
+  static bool isPack(CanType ty) {
+    if (auto gp = dyn_cast<GenericTypeParamType>(ty))
+      return gp->isParameterPack();
+    if (auto dm = dyn_cast<DependentMemberType>(ty))
+      if (auto gp =
+              dyn_cast<GenericTypeParamType>(dm->getBase()->getCanonicalType()))
+        return gp->isParameterPack();
+    return false;
+  }
+
 public:
   Kind getKind() const {
     return kind;
@@ -74,17 +94,34 @@ class GenericRequirement {
     return kind == Kind::Metadata;
   }
 
+  static GenericRequirement forMetadata(CanType type, bool isPack) {
+    auto kind = isPack ? Kind::MetadataPack : Kind::Metadata;
+    return GenericRequirement(kind, type, nullptr);
+  }
+
   static GenericRequirement forMetadata(CanType type) {
-    return GenericRequirement(Kind::Metadata, type, nullptr);
+    return forMetadata(type, isPack(type));
   }
 
   bool isWitnessTable() const {
     return kind == Kind::WitnessTable;
   }
 
+  static GenericRequirement forWitnessTable(CanType type, ProtocolDecl *proto,
+                                            bool isPack) {
+    auto kind = isPack ? Kind::WitnessTablePack : Kind::WitnessTable;
+    return GenericRequirement(kind, type, proto);
+  }
+
   static GenericRequirement forWitnessTable(CanType type, ProtocolDecl *proto) {
-    assert(proto != nullptr);
-    return GenericRequirement(Kind::WitnessTable, type, proto);
+    return forWitnessTable(type, proto, isPack(type));
+  }
+
+  static llvm::Type *typeForKind(irgen::IRGenModule &IGM,
+                                 GenericRequirement::Kind kind);
+
+  llvm::Type *getType(irgen::IRGenModule &IGM) const {
+    return typeForKind(IGM, getKind());
   }
 
   void dump(llvm::raw_ostream &out) const {
@@ -98,6 +135,12 @@ class GenericRequirement {
     case Kind::WitnessTable:
       out << "witness_table: " << type << " : " << proto->getName();
       break;
+    case Kind::MetadataPack:
+      out << "metadata_pack: " << type;
+      break;
+    case Kind::WitnessTablePack:
+      out << "witness_table_pack: " << type << " : " << proto->getName();
+      break;
     }
   }
 };
@@ -109,10 +152,12 @@ template <> struct DenseMapInfo<swift::GenericRequirement> {
   using GenericRequirement = swift::GenericRequirement;
   using CanTypeInfo = llvm::DenseMapInfo<swift::CanType>;
   static GenericRequirement getEmptyKey() {
-    return GenericRequirement::forMetadata(CanTypeInfo::getEmptyKey());
+    return GenericRequirement::forMetadata(CanTypeInfo::getEmptyKey(),
+                                           /*isPack=*/false);
   }
   static GenericRequirement getTombstoneKey() {
-    return GenericRequirement::forMetadata(CanTypeInfo::getTombstoneKey());
+    return GenericRequirement::forMetadata(CanTypeInfo::getTombstoneKey(),
+                                           /*isPack=*/false);
   }
   static llvm::hash_code getHashValue(GenericRequirement req) {
     return hash_combine(CanTypeInfo::getHashValue(req.getTypeParameter()),

lib/IRGen/GenMeta.cpp

@@ -3898,13 +3898,13 @@ namespace {
                                ClassDecl *forClass) {
       switch (requirement.getKind()) {
       case GenericRequirement::Kind::Shape:
-        B.addInt(IGM.SizeTy, 0);
+        B.addInt(cast<llvm::IntegerType>(requirement.getType(IGM)), 0);
         break;
       case GenericRequirement::Kind::Metadata:
-        B.addNullPointer(IGM.TypeMetadataPtrTy);
-        break;
       case GenericRequirement::Kind::WitnessTable:
-        B.addNullPointer(IGM.WitnessTablePtrTy);
+      case GenericRequirement::Kind::MetadataPack:
+      case GenericRequirement::Kind::WitnessTablePack:
+        B.addNullPointer(cast<llvm::PointerType>(requirement.getType(IGM)));
         break;
       }
     }