---

yaml
---
r: 268767
b: refs/heads/marcrasi-const-evaluator-part-2
c: 0f319dd
h: refs/heads/master
i:
  268765: d1131e9
  268763: b30b825
  268759: 0239b72
  268751: cb3e0f3
  268735: e7f256a

Author: gottesmm

[refs]

@@ -1081,7 +1081,7 @@ refs/tags/swift-DEVELOPMENT-SNAPSHOT-2018-09-28-a: c30bf9b3ca148b1b90ebcd80141d9
 refs/heads/bananaphone: 2af9a1dc7f40dcb4b2949876f7e237763d1a7972
 refs/heads/marcrasi-const-evaluator-part-3: 867d96d6aa4cfb5079b7478be617387a1f621c88
 refs/heads/marcrasi-const-evaluator-part-1: 390daeaeea2181a1fc24910e09b5861053cd3558
-refs/heads/marcrasi-const-evaluator-part-2: 8112f68b96b48300b07f6155c49c236f078720e6
+refs/heads/marcrasi-const-evaluator-part-2: 0f319dda67b003c38d56c13b8624bc7e8feef03a
 refs/heads/revert-19689-keep-sourcekitd-response-alive-while-variant-lives: b5b1d9ab2340a64a3c7332529cdca1cb2318d93c
 refs/tags/swift-4.2-DEVELOPMENT-SNAPSHOT-2018-10-01-a: 63059bdab8bbcdd68591738fa28c68c8c19bde75
 refs/tags/swift-4.2-DEVELOPMENT-SNAPSHOT-2018-10-02-a: 12514879eff2c34a64ac6e65b323447f6525cfd0

branches/marcrasi-const-evaluator-part-2/include/swift/AST/Decl.h

@@ -3985,9 +3985,6 @@ class ProtocolDecl final : public NominalTypeDecl {
              ->existentialConformsToSelfSlow();
   }
 
-  /// Does this protocol require a self-conformance witness table?
-  bool requiresSelfConformanceWitnessTable() const;
-
   /// Find direct Self references within the given requirement.
   ///
   /// \param allowCovariantParameters If true, 'Self' is assumed to be

branches/marcrasi-const-evaluator-part-2/include/swift/SIL/SILBuilder.h

@@ -2095,8 +2095,7 @@ class SILBuilder {
   /// lowering for the non-address value.
   void emitDestroyValueOperation(SILLocation Loc, SILValue v) {
     assert(!v->getType().isAddress());
-    if (F->hasQualifiedOwnership() &&
-        v.getOwnershipKind() == ValueOwnershipKind::Any)
+    if (v.getOwnershipKind() == ValueOwnershipKind::Trivial)
       return;
     auto &lowering = getTypeLowering(v->getType());
     lowering.emitDestroyValue(*this, Loc, v);

branches/marcrasi-const-evaluator-part-2/include/swift/SIL/SILCloner.h

@@ -2130,8 +2130,8 @@ void SILCloner<ImplClass>::visitUncheckedOwnershipConversionInst(
   getBuilder().setCurrentDebugScope(getOpScope(Inst->getDebugScope()));
   ValueOwnershipKind Kind = SILValue(Inst).getOwnershipKind();
   if (getOpValue(Inst->getOperand()).getOwnershipKind() ==
-      ValueOwnershipKind::Any) {
-    Kind = ValueOwnershipKind::Any;
+      ValueOwnershipKind::Trivial) {
+    Kind = ValueOwnershipKind::Trivial;
   }
   recordClonedInstruction(Inst, getBuilder().createUncheckedOwnershipConversion(
                                     getOpLocation(Inst->getLoc()),

branches/marcrasi-const-evaluator-part-2/include/swift/SIL/SILInstruction.h

@@ -5023,7 +5023,7 @@ class EnumInst : public InstructionBase<SILInstructionKind::EnumInst,
       : InstructionBase(DebugLoc, ResultTy,
                         Operand
                             ? Operand.getOwnershipKind()
-                            : ValueOwnershipKind(ValueOwnershipKind::Any)),
+                            : ValueOwnershipKind(ValueOwnershipKind::Trivial)),
         Element(Element) {
     if (Operand) {
       OptionalOperand.emplace(this, Operand);

branches/marcrasi-const-evaluator-part-2/include/swift/SIL/SILValue.h

@@ -19,7 +19,6 @@
 
 #include "swift/Basic/Range.h"
 #include "swift/Basic/ArrayRefView.h"
-#include "swift/Basic/STLExtras.h"
 #include "swift/SIL/SILNode.h"
 #include "swift/SIL/SILType.h"
 #include "llvm/ADT/ArrayRef.h"
@@ -87,6 +86,17 @@ llvm::raw_ostream &operator<<(llvm::raw_ostream &os,
 /// have.
 struct ValueOwnershipKind {
   enum innerty : uint8_t {
+    /// A SILValue with Trivial ownership kind is an independent value that can
+    /// not be owned. Ownership does not place any constraints on how a SILValue
+    /// with Trivial ownership kind can be used. Other side effects (e.g. Memory
+    /// dependencies) must still be respected. A SILValue with Trivial ownership
+    /// kind must be of Trivial SILType (i.e. SILType::isTrivial(SILModule &)
+    /// must return true).
+    ///
+    /// Some examples of SIL types with Trivial ownership are: Builtin.Int32,
+    /// Builtin.RawPointer, aggregates containing all trivial types.
+    Trivial,
+
     /// A SILValue with `Unowned` ownership kind is an independent value that
     /// has a lifetime that is only guaranteed to last until the next program
     /// visible side-effect. To maintain the lifetime of an unowned value, it
@@ -117,11 +127,10 @@ struct ValueOwnershipKind {
     /// instruction exactly once along any path through the program.
     Guaranteed,
 
-    /// A SILValue with Any ownership kind is an independent value outside of
-    /// the ownership system. It is used to model trivially typed values as well
-    /// as trivial cases of non-trivial enums. Naturally Any can be merged with
-    /// any ValueOwnershipKind allowing us to naturally model merge and branch
-    /// points in the SSA graph.
+    /// A SILValue with undefined ownership. It can pair with /Any/ ownership
+    /// kinds. This means that it could take on /any/ ownership semantics. This
+    /// is meant only to model SILUndef and to express certain situations where
+    /// we use unqualified ownership. Expected to tighten over time.
     Any,
 
     LastValueOwnershipKind = Any,
@@ -153,6 +162,10 @@ struct ValueOwnershipKind {
 
   Optional<ValueOwnershipKind> merge(ValueOwnershipKind RHS) const;
 
+  bool isTrivialOr(ValueOwnershipKind Kind) const {
+    return Value == Trivial || Value == Kind;
+  }
+
   /// Given that there is an aggregate value (like a struct or enum) with this
   /// ownership kind, and a subobject of type Proj is being projected from the
   /// aggregate, return Trivial if Proj has trivial type and the aggregate's
@@ -167,6 +180,7 @@ struct ValueOwnershipKind {
   /// kinds.
   UseLifetimeConstraint getForwardingLifetimeConstraint() const {
     switch (Value) {
+    case ValueOwnershipKind::Trivial:
     case ValueOwnershipKind::Any:
     case ValueOwnershipKind::Guaranteed:
     case ValueOwnershipKind::Unowned:
@@ -185,16 +199,12 @@ struct ValueOwnershipKind {
     return merge(other).hasValue();
   }
 
-  template <typename RangeTy>
-  static Optional<ValueOwnershipKind> merge(RangeTy &&r) {
-    auto initial = Optional<ValueOwnershipKind>(ValueOwnershipKind::Any);
-    return accumulate(
-        std::forward<RangeTy>(r), initial,
-        [](Optional<ValueOwnershipKind> acc, ValueOwnershipKind x) {
-          if (!acc)
-            return acc;
-          return acc.getValue().merge(x);
-        });
+  /// Returns true if \p Other is compatible with ValueOwnershipKind::Trivial or
+  /// this. See isCompatibleWith for more information on what "compatibility"
+  /// means.
+  bool isTrivialOrCompatibleWith(ValueOwnershipKind other) const {
+    return isCompatibleWith(ValueOwnershipKind::Trivial) ||
+           isCompatibleWith(other);
   }
 };
 

branches/marcrasi-const-evaluator-part-2/include/swift/Serialization/ModuleFormat.h

@@ -52,7 +52,7 @@ const uint16_t SWIFTMODULE_VERSION_MAJOR = 0;
 /// describe what change you made. The content of this comment isn't important;
 /// it just ensures a conflict if two people change the module format.
 /// Don't worry about adhering to the 80-column limit for this line.
-const uint16_t SWIFTMODULE_VERSION_MINOR = 470; // Last change: Remove @trivial
+const uint16_t SWIFTMODULE_VERSION_MINOR = 469; // @_hasStorage
 
 using DeclIDField = BCFixed<31>;
 

branches/marcrasi-const-evaluator-part-2/lib/AST/Decl.cpp

@@ -3910,22 +3910,15 @@ bool ProtocolDecl::requiresClassSlow() {
   return Bits.ProtocolDecl.RequiresClass;
 }
 
-bool ProtocolDecl::requiresSelfConformanceWitnessTable() const {
-  return isSpecificProtocol(KnownProtocolKind::Error);
-}
-
 bool ProtocolDecl::existentialConformsToSelfSlow() {
   // Assume for now that the existential conforms to itself; this
   // prevents circularity issues.
   Bits.ProtocolDecl.ExistentialConformsToSelfValid = true;
   Bits.ProtocolDecl.ExistentialConformsToSelf = true;
 
-  // If it's not @objc, it conforms to itself only if it has a
-  // self-conformance witness table.
   if (!isObjC()) {
-    bool hasSelfConformance = requiresSelfConformanceWitnessTable();
-    Bits.ProtocolDecl.ExistentialConformsToSelf = hasSelfConformance;
-    return hasSelfConformance;
+    Bits.ProtocolDecl.ExistentialConformsToSelf = false;
+    return false;
   }
 
   // Check whether this protocol conforms to itself.

branches/marcrasi-const-evaluator-part-2/lib/AST/Module.cpp

@@ -585,15 +585,6 @@ ModuleDecl::lookupExistentialConformance(Type type, ProtocolDecl *protocol) {
   // existential to an archetype parameter, so for now we restrict this to
   // @objc protocols.
   if (!layout.isObjC()) {
-    // There's a specific exception for protocols with self-conforming
-    // witness tables, but the existential has to be *exactly* that type.
-    // TODO: synthesize witness tables on-demand for protocol compositions
-    // that can satisfy the requirement.
-    if (protocol->requiresSelfConformanceWitnessTable() &&
-        type->is<ProtocolType>() &&
-        type->castTo<ProtocolType>()->getDecl() == protocol)
-      return ProtocolConformanceRef(protocol);
-
     return None;
   }
 
@@ -685,7 +676,7 @@ ModuleDecl::lookupConformance(Type type, ProtocolDecl *protocol) {
   auto nominal = type->getAnyNominal();
 
   // If we don't have a nominal type, there are no conformances.
-  if (!nominal || isa<ProtocolDecl>(nominal)) return None;
+  if (!nominal) return None;
 
   // Find the (unspecialized) conformance.
   SmallVector<ProtocolConformance *, 2> conformances;

branches/marcrasi-const-evaluator-part-2/lib/AST/ProtocolConformance.cpp

@@ -1432,12 +1432,9 @@ DeclContext::getLocalConformances(
   if (!nominal)
     return result;
 
-  // Protocols only have self-conformances.
-  if (auto protocol = dyn_cast<ProtocolDecl>(nominal)) {
-    if (protocol->requiresSelfConformanceWitnessTable())
-      return { protocol->getASTContext().getSelfConformance(protocol) };
+  // Protocols don't have conformances.
+  if (isa<ProtocolDecl>(nominal))
     return { };
-  }
 
   // Update to record all potential conformances.
   nominal->prepareConformanceTable();

branches/marcrasi-const-evaluator-part-2/lib/IRGen/GenProto.cpp

@@ -2876,23 +2876,16 @@ llvm::Value *irgen::emitWitnessTableRef(IRGenFunction &IGF,
   // If we don't have concrete conformance information, the type must be
   // an archetype and the conformance must be via one of the protocol
   // requirements of the archetype. Look at what's locally bound.
-  ProtocolConformance *concreteConformance;
   if (conformance.isAbstract()) {
-    if (auto archetype = dyn_cast<ArchetypeType>(srcType))
-      return emitArchetypeWitnessTableRef(IGF, archetype, proto);
-
-    // Otherwise, this must be a self-conformance.
-    assert(proto->requiresSelfConformanceWitnessTable());
-    assert(cast<ProtocolType>(srcType)->getDecl() == proto);
-    concreteConformance = IGF.IGM.Context.getSelfConformance(proto);
+    auto archetype = cast<ArchetypeType>(srcType);
+    return emitArchetypeWitnessTableRef(IGF, archetype, proto);
+  }
 
   // All other source types should be concrete enough that we have
   // conformance info for them.  However, that conformance info might be
   // more concrete than we're expecting.
   // TODO: make a best effort to devirtualize, maybe?
-  } else {
-    concreteConformance = conformance.getConcrete();
-  }
+  auto concreteConformance = conformance.getConcrete();
   assert(concreteConformance->getProtocol() == proto);
 
   auto cacheKind =

branches/marcrasi-const-evaluator-part-2/lib/IRGen/LoadableByAddress.cpp

@@ -1326,7 +1326,7 @@ SILArgument *LoadableStorageAllocation::replaceArgType(SILBuilder &argBuilder,
                    arg) == pass.largeLoadableArgs.end());
 
   arg = arg->getParent()->replaceFunctionArgument(
-      arg->getIndex(), newSILType, ValueOwnershipKind::Any, arg->getDecl());
+      arg->getIndex(), newSILType, ValueOwnershipKind::Trivial, arg->getDecl());
 
   copyArg->replaceAllUsesWith(arg);
   copyArg->eraseFromParent();
@@ -1352,7 +1352,7 @@ void LoadableStorageAllocation::insertIndirectReturnArgs() {
       ctx.getIdentifier("$return_value"),
       pass.F->getDeclContext());
   pass.F->begin()->insertFunctionArgument(0, resultStorageType.getAddressType(),
-                                          ValueOwnershipKind::Any, var);
+                                          ValueOwnershipKind::Trivial, var);
 }
 
 void LoadableStorageAllocation::convertIndirectFunctionArgs() {

branches/marcrasi-const-evaluator-part-2/lib/ParseSIL/ParseSIL.cpp

@@ -329,12 +329,11 @@ namespace {
     bool parseSILOwnership(ValueOwnershipKind &OwnershipKind) {
       // We parse here @ <identifier>.
       if (!P.consumeIf(tok::at_sign)) {
-        // If we fail, we must have @any ownership.
-        OwnershipKind = ValueOwnershipKind::Any;
-        return false;
+        // Add error here.
+        return true;
       }
 
-      StringRef AllOwnershipKinds[3] = {"unowned", "owned",
+      StringRef AllOwnershipKinds[4] = {"trivial", "unowned", "owned",
                                         "guaranteed"};
       return parseSILIdentifierSwitch(OwnershipKind, AllOwnershipKinds,
                                       diag::expected_sil_value_ownership_kind);