[Serialization] witness_method should reference existing conformances.

Part of a series of commits to remove redundantly-serialized conformances.

Swift SVN r22196

lib/Serialization/DeserializeSIL.cpp

@@ -614,6 +614,8 @@ bool SILDeserializer::readSILInstruction(SILFunction *Fn, SILBasicBlock *BB,
   ValueID ValID, ValID2;
   TypeID TyID, TyID2;
   TypeID ConcreteTyID;
+  DeclID ProtoID;
+  ModuleID OwningModuleID;
   SourceLoc SLoc;
   ArrayRef<uint64_t> ListOfValues;
   SILLocation Loc = SILFileLocation(SLoc);
@@ -673,6 +675,14 @@ bool SILDeserializer::readSILInstruction(SILFunction *Fn, SILBasicBlock *BB,
   case SIL_INST_NO_OPERAND:
     SILInstNoOperandLayout::readRecord(scratch, OpCode);
     break;
+  case SIL_INST_WITNESS_METHOD:
+    SILInstWitnessMethodLayout::readRecord(scratch, TyID, TyCategory, Attr,
+                                           TyID2, TyCategory2,
+                                           ProtoID, ConcreteTyID,
+                                           OwningModuleID,
+                                           ListOfValues);
+    OpCode = (unsigned)ValueKind::WitnessMethodInst;
+    break;
   }
 
   ValueBase *ResultVal;
@@ -1362,7 +1372,6 @@ bool SILDeserializer::readSILInstruction(SILFunction *Fn, SILBasicBlock *BB,
                                              ResultTy);
     break;
   }
-  case ValueKind::WitnessMethodInst:
   case ValueKind::ProtocolMethodInst:
   case ValueKind::ClassMethodInst:
   case ValueKind::SuperMethodInst:
@@ -1370,8 +1379,6 @@ bool SILDeserializer::readSILInstruction(SILFunction *Fn, SILBasicBlock *BB,
     // Format: a type, an operand and a SILDeclRef. Use SILOneTypeValuesLayout:
     // type, Attr, SILDeclRef (DeclID, Kind, uncurryLevel, IsObjC),
     // and an operand.
-    // WitnessMethodInst is additionally optionally followed by a
-    // ProtocolConformance record.
     unsigned NextValueIndex = 1;
     SILDeclRef DRef = getSILDeclRef(MF, ListOfValues, NextValueIndex);
     SILType Ty = getSILType(MF->getType(TyID), (SILValueCategory)TyCategory);
@@ -1384,14 +1391,6 @@ bool SILDeserializer::readSILInstruction(SILFunction *Fn, SILBasicBlock *BB,
 
     switch ((ValueKind)OpCode) {
     default: assert(0 && "Out of sync with parent switch");
-    case ValueKind::WitnessMethodInst: {
-      auto conformance = MF->maybeReadConformance(Ty.getSwiftRValueType(),
-                                                  SILCursor);
-      ResultVal = Builder.createWitnessMethod(Loc, Ty,
-                                              conformance.getValueOr(nullptr),
-                                              DRef, operandTy, IsVolatile);
-      break;
-    }
     case ValueKind::ProtocolMethodInst:
       ResultVal = Builder.createProtocolMethod(Loc,
                     getLocalValue(ListOfValues[NextValueIndex],
@@ -1419,6 +1418,24 @@ bool SILDeserializer::readSILInstruction(SILFunction *Fn, SILBasicBlock *BB,
     }
     break;
   }
+  case ValueKind::WitnessMethodInst: {
+    unsigned NextValueIndex = 0;
+    SILDeclRef DRef = getSILDeclRef(MF, ListOfValues, NextValueIndex);
+    assert(ListOfValues.size() >= NextValueIndex &&
+           "Out of entries for MethodInst");
+
+    SILType Ty = getSILType(MF->getType(TyID), (SILValueCategory)TyCategory);
+    SILType OperandTy = getSILType(MF->getType(TyID2),
+                                   (SILValueCategory)TyCategory2);
+
+    auto *Proto = cast_or_null<ProtocolDecl>(MF->getDecl(ProtoID));
+    auto *Conformance = MF->readReferencedConformance(Proto, ConcreteTyID,
+                                                      OwningModuleID,
+                                                      SILCursor);
+    ResultVal = Builder.createWitnessMethod(Loc, Ty, Conformance, DRef,
+                                            OperandTy, Attr);
+    break;
+  }
   case ValueKind::DynamicMethodBranchInst: {
     // Format: a typed value, a SILDeclRef, a BasicBlock ID for method,
     // a BasicBlock ID for no method. Use SILOneTypeValuesLayout.

lib/Serialization/SILFormat.h

@@ -136,6 +136,7 @@ namespace sil_block {
     SIL_WITNESS_ASSOC_PROTOCOL,
     SIL_WITNESS_ASSOC_ENTRY,
     SIL_GENERIC_OUTER_PARAMS,
+    SIL_INST_WITNESS_METHOD,
 
     // We also share these layouts from the decls block. Their enumerators must
     // not overlap with ours.
@@ -346,6 +347,20 @@ namespace sil_block {
     SIL_GENERIC_OUTER_PARAMS,
     DeclIDField // The decl id of the outer param if any.
   >;
+
+  using SILInstWitnessMethodLayout = BCRecordLayout<
+    SIL_INST_WITNESS_METHOD,
+    TypeIDField,           // result type
+    SILTypeCategoryField,
+    BCFixed<1>,            // volatile?
+    TypeIDField,           // lookup type
+    SILTypeCategoryField,
+    DeclIDField,           // conformance proto
+    TypeIDField,           // conformance type
+    ModuleIDField,         // conformance module
+    BCArray<ValueIDField>  // SILDeclRef
+    // may be trailed by an inline protocol conformance
+  >;
 }
 
 } // end namespace serialization

lib/Serialization/Serialization.cpp

@@ -293,6 +293,7 @@ void Serializer::writeBlockInfoBlock() {
   BLOCK_RECORD(sil_block, SIL_WITNESS_ASSOC_PROTOCOL);
   BLOCK_RECORD(sil_block, SIL_WITNESS_ASSOC_ENTRY);
   BLOCK_RECORD(sil_block, SIL_GENERIC_OUTER_PARAMS);
+  BLOCK_RECORD(sil_block, SIL_INST_WITNESS_METHOD);
 
   // These layouts can exist in both decl blocks and sil blocks.
 #define BLOCK_RECORD_WITH_NAMESPACE(K, X) emitRecordID(Out, X, #X, nameBuffer)

lib/Serialization/SerializeSIL.cpp

@@ -382,7 +382,7 @@ void SILSerializer::writeSILInstruction(const SILInstruction &SI) {
 
     for (auto conformance : conformancesToWrite) {
       S.writeConformance(conformance->getProtocol(), conformance, nullptr,
-                         SILAbbrCodes, /*writeIncomplete=*/true);
+                         SILAbbrCodes);
     }
     break;
   }
@@ -1123,23 +1123,38 @@ void SILSerializer::writeSILInstruction(const SILInstruction &SI) {
     SILType Ty = AMI->getLookupType();
     SILType Ty2 = AMI->getType(0);
 
-    SmallVector<ValueID, 7> ListOfValues;
-    ListOfValues.push_back(AMI->isVolatile());
+    SmallVector<ValueID, 8> ListOfValues;
     handleSILDeclRef(S, AMI->getMember(), ListOfValues);
-    ListOfValues.push_back(S.addTypeRef(Ty2.getSwiftRValueType()));
-    ListOfValues.push_back((unsigned)Ty2.getCategory());
 
-    SILOneTypeValuesLayout::emitRecord(Out, ScratchRecord,
-        SILAbbrCodes[SILOneTypeValuesLayout::Code], (unsigned)SI.getKind(),
-        S.addTypeRef(Ty.getSwiftRValueType()),
-        (unsigned)Ty.getCategory(), ListOfValues);
+    DeclID ConformanceProto;
+    TypeID AdopterTy;
+    ModuleID ConformanceModule;
+    bool WriteConformance = false;
 
-    if (AMI->getConformance())
-      S.writeConformance(
-               cast<ProtocolDecl>(AMI->getMember().getDecl()->getDeclContext()),
+    if (auto *Conformance = AMI->getConformance()) {
+      ConformanceProto = S.addDeclRef(Conformance->getProtocol());
+      WriteConformance = S.encodeReferencedConformance(Conformance,
+                                                       AdopterTy,
+                                                       ConformanceModule,
+                                                       true);
+    } else {
+      ConformanceProto = S.addDeclRef(nullptr);
+    }
+
+    SILInstWitnessMethodLayout::emitRecord(Out, ScratchRecord,
+        SILAbbrCodes[SILInstWitnessMethodLayout::Code],
+        S.addTypeRef(Ty.getSwiftRValueType()), (unsigned)Ty.getCategory(),
+        AMI->isVolatile(),
+        S.addTypeRef(Ty2.getSwiftRValueType()), (unsigned)Ty2.getCategory(),
+        ConformanceProto, AdopterTy, ConformanceModule,
+        ListOfValues);
+
+    if (WriteConformance) {
+      S.writeConformance(AMI->getConformance()->getProtocol(),
                          AMI->getConformance(),
                          nullptr,
                          SILAbbrCodes);
+    }
 
     break;
   }
@@ -1525,6 +1540,7 @@ void SILSerializer::writeSILBlock(const SILModule *SILMod) {
   registerSILAbbr<SILGenericOuterParamsLayout>();
 
   registerSILAbbr<SILInstCastLayout>();
+  registerSILAbbr<SILInstWitnessMethodLayout>();
 
   // Register the abbreviation codes so these layouts can exist in both
   // decl blocks and sil blocks.