[GenericRequirement] Added pack variants.

Added pack flavors of requirement kinds for metadata and witness tables.

Fixes the function signatures for variadic generic functions which
previously used %swift.type* for variadic generic parameters--those are
lists of metadata and should actually be %swift.type**.

Author: nate-chandler

include/swift/IRGen/GenericRequirement.h

@@ -15,6 +15,7 @@
 
 #include "swift/AST/Decl.h"
 #include "swift/AST/Type.h"
+#include "swift/AST/Types.h"
 #include "llvm/Support/raw_ostream.h"
 
 namespace llvm {
@@ -41,10 +42,12 @@ class IRGenModule;
 /// generic signature.
 class GenericRequirement {
 public:
-  enum class Kind: uint8_t {
+  enum class Kind : uint8_t {
     Shape,
     Metadata,
-    WitnessTable
+    WitnessTable,
+    MetadataPack,
+    WitnessTablePack,
   };
 
 private:
@@ -55,6 +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;
@@ -81,17 +94,27 @@ 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,
@@ -112,6 +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;
     }
   }
 };
@@ -123,10 +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

@@ -3902,6 +3902,8 @@ namespace {
         break;
       case GenericRequirement::Kind::Metadata:
       case GenericRequirement::Kind::WitnessTable:
+      case GenericRequirement::Kind::MetadataPack:
+      case GenericRequirement::Kind::WitnessTablePack:
         B.addNullPointer(cast<llvm::PointerType>(requirement.getType(IGM)));
         break;
       }

lib/IRGen/GenProto.cpp

@@ -3560,9 +3560,11 @@ irgen::emitGenericRequirementFromSubstitutions(IRGenFunction &IGF,
     return IGF.emitPackShapeExpression(argType);
 
   case GenericRequirement::Kind::Metadata:
+  case GenericRequirement::Kind::MetadataPack:
     return IGF.emitTypeMetadataRef(argType, request).getMetadata();
 
-  case GenericRequirement::Kind::WitnessTable: {
+  case GenericRequirement::Kind::WitnessTable:
+  case GenericRequirement::Kind::WitnessTablePack: {
     auto proto = requirement.getProtocol();
     auto conformance = subs.lookupConformance(depTy, proto);
     assert(conformance.getRequirement() == proto);
@@ -3618,6 +3620,10 @@ llvm::Type *GenericRequirement::typeForKind(IRGenModule &IGM,
     return IGM.TypeMetadataPtrTy;
   case GenericRequirement::Kind::WitnessTable:
     return IGM.WitnessTablePtrTy;
+  case GenericRequirement::Kind::MetadataPack:
+    return IGM.TypeMetadataPtrPtrTy;
+  case GenericRequirement::Kind::WitnessTablePack:
+    return IGM.WitnessTablePtrPtrTy;
   }
 }
 
@@ -3638,13 +3644,15 @@ void irgen::bindGenericRequirement(IRGenFunction &IGF,
     break;
   }
 
-  case GenericRequirement::Kind::Metadata: {
+  case GenericRequirement::Kind::Metadata:
+  case GenericRequirement::Kind::MetadataPack: {
     setTypeMetadataName(IGF.IGM, value, type);
     IGF.bindLocalTypeDataFromTypeMetadata(type, IsExact, value, metadataState);
     break;
   }
 
-  case GenericRequirement::Kind::WitnessTable: {
+  case GenericRequirement::Kind::WitnessTable:
+  case GenericRequirement::Kind::WitnessTablePack: {
     auto proto = requirement.getProtocol();
     assert(isa<ArchetypeType>(type));
     setProtocolWitnessTableName(IGF.IGM, value, type, proto);
@@ -3683,9 +3691,11 @@ namespace {
           ++numShapes;
           break;
         case GenericRequirement::Kind::Metadata:
+        case GenericRequirement::Kind::MetadataPack:
           ++numTypeMetadataPtrs;
           break;
         case GenericRequirement::Kind::WitnessTable:
+        case GenericRequirement::Kind::WitnessTablePack:
           ++numWitnessTablePtrs;
           break;
         }

test/IRGen/variadic_generic_functions.swift

@@ -5,11 +5,11 @@
 
 // REQUIRES: PTRSIZE=64
 
-// CHECK-LABEL: define hidden swiftcc void @"$s26variadic_generic_functions2f11tyxxQp_tlF"(%swift.opaque** noalias nocapture %0, i64 %1, %swift.type* %T)
+// CHECK-LABEL: define hidden swiftcc void @"$s26variadic_generic_functions2f11tyxxQp_tlF"(%swift.opaque** noalias nocapture %0, i64 %1, %swift.type** %T)
 func f1<T...>(t: repeat each T) {}
 
-// CHECK-LABEL: define hidden swiftcc void @"$s26variadic_generic_functions2f21t1uyxxQp_q_q_Qptr0_lF"(%swift.opaque** noalias nocapture %0, %swift.opaque** noalias nocapture %1, i64 %2, i64 %3, %swift.type* %T, %swift.type* %U)
+// CHECK-LABEL: define hidden swiftcc void @"$s26variadic_generic_functions2f21t1uyxxQp_q_q_Qptr0_lF"(%swift.opaque** noalias nocapture %0, %swift.opaque** noalias nocapture %1, i64 %2, i64 %3, %swift.type** %T, %swift.type** %U)
 func f2<T..., U...>(t: repeat each T, u: repeat each U) {}
 
-// CHECK-LABEL: define hidden swiftcc void @"$s26variadic_generic_functions2f31t1uyxxQp_q_xQptq_Rhzr0_lF"(%swift.opaque** noalias nocapture %0, %swift.opaque** noalias nocapture %1, i64 %2, %swift.type* %T, %swift.type* %U)
+// CHECK-LABEL: define hidden swiftcc void @"$s26variadic_generic_functions2f31t1uyxxQp_q_xQptq_Rhzr0_lF"(%swift.opaque** noalias nocapture %0, %swift.opaque** noalias nocapture %1, i64 %2, %swift.type** %T, %swift.type** %U)
 func f3<T..., U...>(t: repeat each T, u: repeat each U) where (repeat (each T, each U)): Any {}