Merge pull request #62515 from slavapestov/irgen-generic-requirement

IRGen: Refactor GenericRequirement

Author: slavapestov

include/swift/AST/GenericRequirement.h

@@ -0,0 +1,129 @@
+//===--- GenericRequirement.h - Generic requirement -------------*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SWIFT_AST_GENERIC_REQUIREMENT_H
+#define SWIFT_AST_GENERIC_REQUIREMENT_H
+
+#include "swift/AST/Decl.h"
+#include "swift/AST/Type.h"
+#include "llvm/Support/raw_ostream.h"
+
+namespace swift {
+
+class ProtocolDecl;
+
+/// The three kinds of entities passed in the runtime calling convention for
+/// generic code: pack shapes, type metadata, and witness tables.
+///
+/// A pack shape describes an equivalence class of type parameter packs; the
+/// runtime value is a single integer, which is the length of the pack.
+///
+/// Type metadata is emitted for each reduced generic parameter (that is,
+/// not same-type constrained to another generic parameter or concrete type).
+///
+/// A witness table is emitted for each conformance requirement in the
+/// generic signature.
+class GenericRequirement {
+public:
+  enum class Kind: uint8_t {
+    Shape,
+    Metadata,
+    WitnessTable
+  };
+
+private:
+  Kind kind;
+  CanType type;
+  ProtocolDecl *proto;
+
+  GenericRequirement(Kind kind, CanType type, ProtocolDecl *proto)
+    : kind(kind), type(type), proto(proto) {}
+
+public:
+  Kind getKind() const {
+    return kind;
+  }
+
+  CanType getTypeParameter() const {
+    return type;
+  }
+
+  ProtocolDecl *getProtocol() const {
+    return proto;
+  }
+
+  bool isShape() const {
+    return kind == Kind::Shape;
+  }
+
+  static GenericRequirement forShape(CanType type) {
+    assert(type->isParameterPack());
+    return GenericRequirement(Kind::Shape, type, nullptr);
+  }
+
+  bool isMetadata() const {
+    return kind == Kind::Metadata;
+  }
+
+  static GenericRequirement forMetadata(CanType type) {
+    return GenericRequirement(Kind::Metadata, type, nullptr);
+  }
+
+  bool isWitnessTable() const {
+    return kind == Kind::WitnessTable;
+  }
+
+  static GenericRequirement forWitnessTable(CanType type, ProtocolDecl *proto) {
+    assert(proto != nullptr);
+    return GenericRequirement(Kind::WitnessTable, type, proto);
+  }
+
+  void dump(llvm::raw_ostream &out) const {
+    switch (kind) {
+    case Kind::Shape:
+      out << "shape: " << type;
+      break;
+    case Kind::Metadata:
+      out << "metadata: " << type;
+      break;
+    case Kind::WitnessTable:
+      out << "witness_table: " << type << " : " << proto->getName();
+      break;
+    }
+  }
+};
+
+} // end namespace swift
+
+namespace llvm {
+template <> struct DenseMapInfo<swift::GenericRequirement> {
+  using GenericRequirement = swift::GenericRequirement;
+  using CanTypeInfo = llvm::DenseMapInfo<swift::CanType>;
+  static GenericRequirement getEmptyKey() {
+    return GenericRequirement::forMetadata(CanTypeInfo::getEmptyKey());
+  }
+  static GenericRequirement getTombstoneKey() {
+    return GenericRequirement::forMetadata(CanTypeInfo::getTombstoneKey());
+  }
+  static llvm::hash_code getHashValue(GenericRequirement req) {
+    return hash_combine(CanTypeInfo::getHashValue(req.getTypeParameter()),
+                        hash_value(req.getProtocol()));
+  }
+  static bool isEqual(GenericRequirement lhs, GenericRequirement rhs) {
+    return (lhs.getKind() == rhs.getKind() &&
+            lhs.getTypeParameter() == rhs.getTypeParameter() &&
+            lhs.getProtocol() == rhs.getProtocol());
+  }
+};
+} // end namespace llvm
+
+#endif // SWIFT_AST_GENERIC_REQUIREMENT_H

include/swift/IRGen/GenericRequirement.h

@@ -14,9 +14,9 @@
 #define SWIFT_IRGEN_IRABIDETAILSPROVIDER_H
 
 #include "swift/AST/Decl.h"
-#include "swift/AST/GenericRequirement.h"
 #include "swift/AST/Type.h"
 #include "swift/AST/Types.h"
+#include "swift/IRGen/GenericRequirement.h"
 #include "clang/AST/CharUnits.h"
 #include "llvm/ADT/MapVector.h"
 #include "llvm/ADT/Optional.h"

include/swift/IRGen/IRABIDetailsProvider.h

@@ -18,7 +18,7 @@ class Value;
 
 namespace swift {
 
-struct GenericRequirement;
+class GenericRequirement;
 class SILArgument;
 
 namespace irgen {

lib/IRGen/EntryPointArgumentEmission.h

@@ -150,7 +150,7 @@ bool FulfillmentMap::searchTypeMetadata(IRGenModule &IGM, CanType type,
     }
 
     // Add the fulfillment.
-    hadFulfillment |= addFulfillment({type, nullptr},
+    hadFulfillment |= addFulfillment(GenericRequirement::forMetadata(type),
                                      source, std::move(path), metadataState);
     return hadFulfillment;
   }
@@ -251,8 +251,9 @@ bool FulfillmentMap::searchWitnessTable(
   // If we're not limiting the set of interesting conformances, or if
   // this is an interesting conformance, record it.
   if (!interestingConformances || interestingConformances->count(protocol)) {
-    hadFulfillment |= addFulfillment({type, protocol}, source,
-                                     std::move(path), MetadataState::Complete);
+    hadFulfillment |= addFulfillment(
+        GenericRequirement::forWitnessTable(type, protocol), source,
+        std::move(path), MetadataState::Complete);
   }
 
   return hadFulfillment;
@@ -315,7 +316,7 @@ bool FulfillmentMap::searchNominalTypeMetadata(IRGenModule &IGM,
 }
 
 /// Testify that there's a fulfillment at the given path.
-bool FulfillmentMap::addFulfillment(FulfillmentKey key,
+bool FulfillmentMap::addFulfillment(GenericRequirement key,
                                     unsigned source,
                                     MetadataPath &&path,
                                     MetadataState metadataState) {
@@ -360,10 +361,8 @@ static StringRef getStateName(MetadataState state) {
 void FulfillmentMap::dump() const {
   auto &out = llvm::errs();
   for (auto &entry : Fulfillments) {
-    out << "(" << entry.first.first;
-    if (auto proto = entry.first.second) {
-      out << ", " << proto->getNameStr();
-    }
+    out << "(";
+    entry.first.dump(out);
     out << ") => " << getStateName(entry.second.getState())
         << " at sources[" << entry.second.SourceIndex
         << "]." << entry.second.Path << "\n";

lib/IRGen/Fulfillment.cpp

@@ -21,6 +21,7 @@
 #include "llvm/ADT/DenseMap.h"
 #include "swift/AST/Types.h"
 #include "swift/AST/GenericSignature.h"
+#include "swift/IRGen/GenericRequirement.h"
 #include "MetadataPath.h"
 
 namespace swift {
@@ -48,9 +49,7 @@ struct Fulfillment {
 };
 
 class FulfillmentMap {
-  using FulfillmentKey = std::pair<Type, ProtocolDecl*>;
-
-  llvm::DenseMap<FulfillmentKey, Fulfillment> Fulfillments;
+  llvm::DenseMap<GenericRequirement, Fulfillment> Fulfillments;
 
 public:
   struct InterestingKeysCallback {
@@ -115,25 +114,28 @@ class FulfillmentMap {
   ///
   /// \return true if the fulfillment was added, which won't happen if there's
   ///   already a fulfillment that was at least as good
-  bool addFulfillment(FulfillmentKey key, unsigned source,
+  bool addFulfillment(GenericRequirement key, unsigned source,
                       MetadataPath &&path, MetadataState state);
 
-  const Fulfillment *getTypeMetadata(CanType type) const {
-    auto it = Fulfillments.find({type, nullptr});
+  const Fulfillment *getFulfillment(GenericRequirement key) const {
+    auto it = Fulfillments.find(key);
     if (it != Fulfillments.end()) {
       return &it->second;
     } else {
       return nullptr;
     }
   }
 
+  const Fulfillment *getShape(CanType type) const {
+    return getFulfillment(GenericRequirement::forShape(type));
+  }
+
+  const Fulfillment *getTypeMetadata(CanType type) const {
+    return getFulfillment(GenericRequirement::forMetadata(type));
+  }
+
   const Fulfillment *getWitnessTable(CanType type, ProtocolDecl *proto) const {
-    auto it = Fulfillments.find({type, proto});
-    if (it != Fulfillments.end()) {
-      return &it->second;
-    } else {
-      return nullptr;
-    }
+    return getFulfillment(GenericRequirement::forWitnessTable(type, proto));
   }
 
   void dump() const;

lib/IRGen/Fulfillment.h

@@ -435,14 +435,15 @@ withOpaqueTypeGenericArgs(IRGenFunction &IGF,
     enumerateGenericSignatureRequirements(
         opaqueDecl->getGenericSignature().getCanonicalSignature(),
         [&](GenericRequirement reqt) {
-          auto ty = reqt.TypeParameter.subst(archetype->getSubstitutions())
+          auto ty = reqt.getTypeParameter().subst(archetype->getSubstitutions())
                         ->getReducedType(opaqueDecl->getGenericSignature());
-          if (reqt.Protocol) {
+          if (reqt.isWitnessTable()) {
             auto ref =
-                ProtocolConformanceRef(reqt.Protocol)
-                    .subst(reqt.TypeParameter, archetype->getSubstitutions());
+                ProtocolConformanceRef(reqt.getProtocol())
+                    .subst(reqt.getTypeParameter(), archetype->getSubstitutions());
             args.push_back(emitWitnessTableRef(IGF, ty, ref));
           } else {
+            assert(reqt.isMetadata());
             args.push_back(IGF.emitAbstractTypeMetadataRef(ty));
           }
           types.push_back(args.back()->getType());

lib/IRGen/GenArchetype.cpp

@@ -886,7 +886,7 @@ emitKeyPathComponent(IRGenModule &IGM,
         enumerateGenericSignatureRequirements(
             componentCanSig, [&](GenericRequirement reqt) {
               auto substType =
-                  reqt.TypeParameter.subst(subs)->getCanonicalType();
+                  reqt.getTypeParameter().subst(subs)->getCanonicalType();
 
               // FIXME: This seems wrong. We used to just mangle opened archetypes as
               // their interface type. Let's make that explicit now.
@@ -896,14 +896,17 @@ emitKeyPathComponent(IRGenModule &IGM,
                 return None;
               })->getCanonicalType();
 
-              if (!reqt.Protocol) {
+              if (reqt.isMetadata()) {
                 // Type requirement.
                 externalSubArgs.push_back(emitMetadataTypeRefForKeyPath(
                     IGM, substType, componentCanSig));
               } else {
+                assert(reqt.isWitnessTable());
+
                 // Protocol requirement.
                 auto conformance = subs.lookupConformance(
-                    reqt.TypeParameter->getCanonicalType(), reqt.Protocol);
+                    reqt.getTypeParameter()->getCanonicalType(),
+                    reqt.getProtocol());
                 externalSubArgs.push_back(IGM.emitWitnessTableRefString(
                     substType, conformance,
                     genericEnv ? genericEnv->getGenericSignature() : nullptr,

lib/IRGen/GenKeyPath.cpp

@@ -4250,20 +4250,21 @@ namespace {
     }
 
     void addGenericArgument(GenericRequirement requirement) {
-      auto t = requirement.TypeParameter.subst(genericSubstitutions());
+      auto t = requirement.getTypeParameter().subst(genericSubstitutions());
       ConstantReference ref = IGM.getAddrOfTypeMetadata(
           CanType(t), SymbolReferenceKind::Relative_Direct);
       this->B.add(ref.getDirectValue());
     }
 
     void addGenericWitnessTable(GenericRequirement requirement) {
       auto conformance = genericSubstitutions().lookupConformance(
-          requirement.TypeParameter->getCanonicalType(), requirement.Protocol);
+          requirement.getTypeParameter()->getCanonicalType(),
+          requirement.getProtocol());
       ProtocolConformance *concreteConformance = conformance.getConcrete();
 
       llvm::Constant *addr;
 
-      Type argument = requirement.TypeParameter.subst(genericSubstitutions());
+      Type argument = requirement.getTypeParameter().subst(genericSubstitutions());
       auto argumentNominal = argument->getAnyNominal();
       if (argumentNominal && argumentNominal->isGenericContext()) {
         // TODO: Statically specialize the witness table pattern for t's