Runtime support for identity key paths.

include/swift/AST/Builtins.def

@@ -390,6 +390,11 @@ BUILTIN_SIL_OPERATION(AllocWithTailElems, "allocWithTailElems", Special)
 /// Projects the first tail-allocated element of type E from a class C.
 BUILTIN_SIL_OPERATION(ProjectTailElems, "projectTailElems", Special)
 
+/// identityKeyPath : <T> () -> WritableKeyPath<T, T>
+///
+/// Creates an identity key path object. (TODO: replace with proper syntax)
+BUILTIN_SIL_OPERATION(IdentityKeyPath, "identityKeyPath", Special)
+
 #undef BUILTIN_SIL_OPERATION
 
 // BUILTIN_RUNTIME_CALL - A call into a runtime function.

include/swift/AST/DiagnosticsParse.def

@@ -583,8 +583,6 @@ ERROR(sil_keypath_computed_property_missing_part,none,
 ERROR(sil_keypath_external_missing_part,none,
       "keypath external component with indices needs an indices_equals and "
       "indices_hash function", ())
-ERROR(sil_keypath_no_components,none,
-      "keypath must have at least one component", ())
 ERROR(sil_keypath_no_root,none,
       "keypath must have a root component declared",())
 ERROR(sil_keypath_index_not_hashable,none,

lib/AST/Builtins.cpp

@@ -556,6 +556,20 @@ makeTuple(const Gs & ...elementGenerators) {
   };
 }
 
+template <class... Gs>
+static BuiltinGenericSignatureBuilder::LambdaGenerator
+makeBoundGenericType(NominalTypeDecl *decl,
+                     const Gs & ...argumentGenerators) {
+  return {
+    [=](BuiltinGenericSignatureBuilder &builder) -> Type {
+      Type args[] = {
+        argumentGenerators.build(builder)...
+      };
+      return BoundGenericType::get(decl, Type(), args);
+    }
+  };
+}
+
 template <class T>
 static BuiltinGenericSignatureBuilder::MetatypeGenerator<T>
 makeMetatype(const T &object, Optional<MetatypeRepresentation> repr = None) {
@@ -972,6 +986,15 @@ static ValueDecl *getTypeJoinMetaOperation(ASTContext &Context, Identifier Id) {
   return builder.build(Id);
 }
 
+static ValueDecl *getIdentityKeyPathOperation(ASTContext &Context,
+                                              Identifier Id) {
+  BuiltinGenericSignatureBuilder builder(Context, 1);
+  auto arg = makeGenericParam();
+  builder.setResult(makeBoundGenericType(Context.getWritableKeyPathDecl(),
+                                         arg, arg));
+  return builder.build(Id);
+}
+
 static ValueDecl *getCanBeObjCClassOperation(ASTContext &Context,
                                              Identifier Id) {
   // <T> T.Type -> Builtin.Int8
@@ -1865,6 +1888,9 @@ ValueDecl *swift::getBuiltinValueDecl(ASTContext &Context, Identifier Id) {
 
   case BuiltinValueKind::TypeJoinMeta:
     return getTypeJoinMetaOperation(Context, Id);
+
+  case BuiltinValueKind::IdentityKeyPath:
+    return getIdentityKeyPathOperation(Context, Id);
   }
 
   llvm_unreachable("bad builtin value!");

lib/ParseSIL/ParseSIL.cpp

@@ -2884,8 +2884,6 @@ bool SILParser::parseSILInstruction(SILBuilder &B) {
         return true;
     }
 
-    if (components.empty())
-      P.diagnose(InstLoc.getSourceLoc(), diag::sil_keypath_no_components);
     if (rootType.isNull())
       P.diagnose(InstLoc.getSourceLoc(), diag::sil_keypath_no_root);
 
@@ -2943,8 +2941,13 @@ bool SILParser::parseSILInstruction(SILBuilder &B) {
     if (patternEnv && patternEnv->getGenericSignature()) {
       canSig = patternEnv->getGenericSignature()->getCanonicalSignature();
     }
+    CanType leafType;
+    if (!components.empty())
+      leafType = components.back().getComponentType();
+    else
+      leafType = rootType;
     auto pattern = KeyPathPattern::get(B.getModule(), canSig,
-                     rootType, components.back().getComponentType(),
+                     rootType, leafType,
                      components, objcString);
 
     ResultVal = B.createKeyPath(InstLoc, pattern, subMap, operands, Ty);

lib/SIL/SILOwnershipVerifier.cpp

@@ -1288,56 +1288,14 @@ CONSTANT_OWNERSHIP_BUILTIN(Trivial, MustBeLive, Swift3ImplicitObjCEntrypoint)
 
 // Builtins that should be lowered to SIL instructions so we should never see
 // them.
-#define BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(ID)                 \
+#define BUILTIN_SIL_OPERATION(ID, NAME, CATEGORY)                              \
   OwnershipUseCheckerResult                                                    \
       OwnershipCompatibilityBuiltinUseChecker::visit##ID(BuiltinInst *BI,      \
                                                          StringRef Attr) {     \
     llvm_unreachable("Builtin should have been lowered to SIL instruction?!"); \
   }
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(Retain)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(Release)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(Autorelease)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(TryPin)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(Unpin)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(Load)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(LoadRaw)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(LoadInvariant)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(Take)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(Destroy)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(Assign)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(Init)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(CastToNativeObject)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(UnsafeCastToNativeObject)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(CastFromNativeObject)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(CastToBridgeObject)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(
-    CastReferenceFromBridgeObject)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(
-    CastBitPatternFromBridgeObject)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(ClassifyBridgeObject)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(ValueToBridgeObject)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(BridgeToRawPointer)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(BridgeFromRawPointer)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(CastReference)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(ReinterpretCast)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(AddressOf)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(AddressOfBorrow)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(GepRaw)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(Gep)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(GetTailAddr)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(PerformInstantaneousReadAccess)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(BeginUnpairedModifyAccess)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(EndUnpairedAccess)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(CondFail)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(FixLifetime)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(IsUnique)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(IsUniqueOrPinned)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(IsUnique_native)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(IsUniqueOrPinned_native)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(BindMemory)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(AllocWithTailElems)
-BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS(ProjectTailElems)
-#undef BUILTINS_THAT_SHOULD_HAVE_BEEN_LOWERED_TO_SILINSTS
+#define BUILTIN(X, Y, Z)
+#include "swift/AST/Builtins.def"
 
 OwnershipUseCheckerResult
 OwnershipCompatibilityUseChecker::visitBuiltinInst(BuiltinInst *BI) {

lib/SIL/ValueOwnershipKindClassifier.cpp

@@ -397,8 +397,6 @@ struct ValueOwnershipKindBuiltinVisitor
     }                                                                          \
     return ValueOwnershipKind::OWNERSHIP;                                      \
   }
-CONSTANT_OWNERSHIP_BUILTIN(Owned, Take)
-CONSTANT_OWNERSHIP_BUILTIN(Owned, TryPin)
 // This returns a value at +1 that is destroyed strictly /after/ the
 // UnsafeGuaranteedEnd. This provides the guarantee that we want.
 CONSTANT_OWNERSHIP_BUILTIN(Owned, UnsafeGuaranteed)
@@ -443,9 +441,6 @@ CONSTANT_OWNERSHIP_BUILTIN(Trivial, ICMP_ULE)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, ICMP_ULT)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, IntToPtr)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, LShr)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, Load)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, LoadRaw)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, LoadInvariant)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, Mul)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, Or)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, PtrToInt)
@@ -472,32 +467,7 @@ CONSTANT_OWNERSHIP_BUILTIN(Trivial, ZExt)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, ZExtOrBitCast)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, FCMP_ORD)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, FCMP_UNO)
-CONSTANT_OWNERSHIP_BUILTIN(Unowned, CastToNativeObject)
-CONSTANT_OWNERSHIP_BUILTIN(Unowned, UnsafeCastToNativeObject)
-CONSTANT_OWNERSHIP_BUILTIN(Unowned, CastFromNativeObject)
-CONSTANT_OWNERSHIP_BUILTIN(Unowned, CastToBridgeObject)
-CONSTANT_OWNERSHIP_BUILTIN(Unowned, CastReferenceFromBridgeObject)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, CastBitPatternFromBridgeObject)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, ClassifyBridgeObject)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, BridgeToRawPointer)
-CONSTANT_OWNERSHIP_BUILTIN(Unowned, BridgeFromRawPointer)
-CONSTANT_OWNERSHIP_BUILTIN(Unowned, CastReference)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, AddressOf)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, AddressOfBorrow)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, GepRaw)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, Gep)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, GetTailAddr)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, PerformInstantaneousReadAccess)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, BeginUnpairedModifyAccess)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, EndUnpairedAccess)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, OnFastPath)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, IsUnique)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, IsUniqueOrPinned)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, IsUnique_native)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, IsUniqueOrPinned_native)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, BindMemory)
-CONSTANT_OWNERSHIP_BUILTIN(Owned, AllocWithTailElems)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, ProjectTailElems)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, IsOptionalType)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, Sizeof)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, Strideof)
@@ -543,21 +513,11 @@ CONSTANT_OWNERSHIP_BUILTIN(Trivial, UnexpectedError)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, ErrorInMain)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, DeallocRaw)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, Fence)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, Retain)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, Release)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, CondFail)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, FixLifetime)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, Autorelease)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, Unpin)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, Destroy)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, Assign)
-CONSTANT_OWNERSHIP_BUILTIN(Trivial, Init)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, AtomicStore)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, Once)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, OnceWithContext)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, TSanInoutAccess)
 CONSTANT_OWNERSHIP_BUILTIN(Trivial, Swift3ImplicitObjCEntrypoint)
-CONSTANT_OWNERSHIP_BUILTIN(Unowned, ValueToBridgeObject)
 
 #undef CONSTANT_OWNERSHIP_BUILTIN
 
@@ -570,14 +530,22 @@ CONSTANT_OWNERSHIP_BUILTIN(Unowned, ValueToBridgeObject)
     }                                                                          \
     return ValueOwnershipKind::Unowned;                                        \
   }
-UNOWNED_OR_TRIVIAL_DEPENDING_ON_RESULT(ReinterpretCast)
 UNOWNED_OR_TRIVIAL_DEPENDING_ON_RESULT(CmpXChg)
 UNOWNED_OR_TRIVIAL_DEPENDING_ON_RESULT(AtomicLoad)
 UNOWNED_OR_TRIVIAL_DEPENDING_ON_RESULT(ExtractElement)
 UNOWNED_OR_TRIVIAL_DEPENDING_ON_RESULT(InsertElement)
 UNOWNED_OR_TRIVIAL_DEPENDING_ON_RESULT(ZeroInitializer)
 #undef UNOWNED_OR_TRIVIAL_DEPENDING_ON_RESULT
 
+#define BUILTIN(X,Y,Z)
+#define BUILTIN_SIL_OPERATION(ID, NAME, CATEGORY) \
+  ValueOwnershipKind ValueOwnershipKindBuiltinVisitor::visit##ID( \
+      BuiltinInst *BI, StringRef Attr) { \
+    llvm_unreachable("builtin should have been lowered in SILGen"); \
+  }
+
+#include "swift/AST/Builtins.def"
+
 ValueOwnershipKind
 ValueOwnershipKindClassifier::visitBuiltinInst(BuiltinInst *BI) {
   // For now, just conservatively say builtins are None. We need to use a

lib/SILGen/SILGenBuiltin.cpp

@@ -21,6 +21,7 @@
 #include "swift/AST/ASTContext.h"
 #include "swift/AST/Builtins.h"
 #include "swift/AST/DiagnosticsSIL.h"
+#include "swift/AST/GenericEnvironment.h"
 #include "swift/AST/Module.h"
 #include "swift/AST/ReferenceCounting.h"
 #include "swift/SIL/SILArgument.h"
@@ -1055,6 +1056,58 @@ static ManagedValue emitBuiltinProjectTailElems(SILGenFunction &SGF,
   return ManagedValue::forUnmanaged(result);
 }
 
+static ManagedValue emitBuiltinIdentityKeyPath(SILGenFunction &SGF,
+                                               SILLocation loc,
+                                               SubstitutionMap subs,
+                                               ArrayRef<ManagedValue> args,
+                                               SGFContext C) {
+  assert(subs.getReplacementTypes().size() == 1 &&
+         "identityKeyPath should have one substitution");
+  assert(args.size() == 0 &&
+         "identityKeyPath should have no args");
+
+  auto identityTy = subs.getReplacementTypes()[0]->getCanonicalType();
+
+  // The `self` key can be used for identity in Cocoa KVC as well.
+  StringRef objcString = SGF.getASTContext().LangOpts.EnableObjCInterop
+    ? "self" : "";
+
+  // The key path pattern has to capture some generic context if the type is
+  // dependent on this generic context. We only need the specific type, though,
+  // not the entire generic environment.
+  bool isDependent = identityTy->hasArchetype();
+  CanType identityPatternTy = identityTy;
+  CanGenericSignature patternSig = nullptr;
+  SubstitutionMap patternSubs;
+  if (isDependent) {
+    auto param = GenericTypeParamType::get(0, 0, SGF.getASTContext());
+    identityPatternTy = param->getCanonicalType();
+    patternSig = GenericSignature::get(param, {})->getCanonicalSignature();
+    patternSubs = SubstitutionMap::get(patternSig,
+                                       llvm::makeArrayRef((Type)identityTy),
+                                       {});
+  }
+
+  auto identityPattern = KeyPathPattern::get(SGF.SGM.M,
+                                             patternSig,
+                                             identityPatternTy,
+                                             identityPatternTy,
+                                             {},
+                                             objcString);
+
+  auto kpTy = BoundGenericType::get(SGF.getASTContext().getWritableKeyPathDecl(),
+                                    Type(),
+                                    {identityTy, identityTy})
+    ->getCanonicalType();
+
+  auto keyPath = SGF.B.createKeyPath(loc, identityPattern,
+                                     patternSubs,
+                                     {},
+                                     SILType::getPrimitiveObjectType(kpTy));
+  return SGF.emitManagedRValueWithCleanup(keyPath);
+}
+
+
 /// Specialized emitter for type traits.
 template<TypeTraitResult (TypeBase::*Trait)(),
          BuiltinValueKind Kind>