Merge pull request swiftlang#38929 from apple/revert-38816-emit-closure-literal-at-context-abstraction

Revert " SILGen: Emit literal closures at the abstraction level of their context."

Author: hborla

include/swift/SIL/AbstractionPattern.h

@@ -432,7 +432,6 @@ class AbstractionPattern {
     const clang::ObjCMethodDecl *ObjCMethod;
     const clang::CXXMethodDecl *CXXMethod;
     const AbstractionPattern *OrigTupleElements;
-    const void *RawTypePtr;
   };
   CanGenericSignature GenericSig;
 
@@ -1275,7 +1274,7 @@ class AbstractionPattern {
   /// pattern?
   bool matchesTuple(CanTupleType substType);
 
-  bool isTuple() const {
+  bool isTuple() {
     switch (getKind()) {
     case Kind::Invalid:
       llvm_unreachable("querying invalid abstraction pattern!");
@@ -1387,32 +1386,8 @@ class AbstractionPattern {
       Lowering::TypeConverter &TC
   ) const;
 
-  /// How values are passed or returned according to this abstraction pattern.
-  enum CallingConventionKind {
-    // Value is passed or returned directly as a unit.
-    Direct,
-    // Value is passed or returned indirectly through memory.
-    Indirect,
-    // Value is a tuple that is destructured, and each element is considered
-    // independently.
-    Destructured,
-  };
-  
-  /// If this abstraction pattern appears in function return position, how is
-  /// the corresponding value returned?
-  CallingConventionKind getResultConvention(TypeConverter &TC) const;
-  
-  /// If this abstraction pattern appears in function parameter position, how
-  /// is the corresponding value passed?
-  CallingConventionKind getParameterConvention(TypeConverter &TC) const;
-  
   void dump() const LLVM_ATTRIBUTE_USED;
   void print(raw_ostream &OS) const;
-  
-  bool operator==(const AbstractionPattern &other) const;
-  bool operator!=(const AbstractionPattern &other) const {
-    return !(*this == other);
-  }
 };
 
 inline llvm::raw_ostream &operator<<(llvm::raw_ostream &out,

include/swift/SIL/TypeLowering.h

@@ -734,9 +734,6 @@ class TypeConverter {
   ///
   /// Second element is a ResilienceExpansion.
   llvm::DenseMap<std::pair<SILType, unsigned>, unsigned> TypeFields;
-  
-  llvm::DenseMap<AbstractClosureExpr *, Optional<AbstractionPattern>>
-    ClosureAbstractionPatterns;
 
   CanAnyFunctionType makeConstantInterfaceType(SILDeclRef constant);
 
@@ -1109,22 +1106,6 @@ class TypeConverter {
                                          SILType enumType,
                                          EnumElementDecl *elt);
 
-  /// Get the preferred abstraction pattern, if any, by which to lower a
-  /// declaration.
-  ///
-  /// This can be set using \c setAbstractionPattern , but only before
-  /// the abstraction pattern is queried using this function. Once the
-  /// abstraction pattern has been asked for, it may not be changed.
-  Optional<AbstractionPattern> getConstantAbstractionPattern(SILDeclRef constant);
-  
-  /// Set the preferred abstraction pattern for a closure.
-  ///
-  /// The abstraction pattern can only be set before any calls to
-  /// \c getConstantAbstractionPattern on the same closure. It may not be
-  /// changed once it has been read.
-  void setAbstractionPattern(AbstractClosureExpr *closure,
-                             AbstractionPattern pattern);
-  
 private:
   CanType computeLoweredRValueType(TypeExpansionContext context,
                                    AbstractionPattern origType,

lib/SIL/IR/AbstractionPattern.cpp

@@ -1233,155 +1233,3 @@ AbstractionPattern AbstractionPattern::getAutoDiffDerivativeFunctionType(
     llvm_unreachable("called on unsupported abstraction pattern kind");
   }
 }
-
-AbstractionPattern::CallingConventionKind
-AbstractionPattern::getResultConvention(TypeConverter &TC) const {
-  // Tuples should be destructured.
-  if (isTuple()) {
-    return Destructured;
-  }
-  switch (getKind()) {
-  case Kind::Opaque:
-    // Maximally abstracted values are always passed indirectly.
-    return Indirect;
-  
-  case Kind::OpaqueFunction:
-  case Kind::OpaqueDerivativeFunction:
-  case Kind::PartialCurriedObjCMethodType:
-  case Kind::CurriedObjCMethodType:
-  case Kind::PartialCurriedCFunctionAsMethodType:
-  case Kind::CurriedCFunctionAsMethodType:
-  case Kind::CFunctionAsMethodType:
-  case Kind::ObjCMethodType:
-  case Kind::CXXMethodType:
-  case Kind::CurriedCXXMethodType:
-  case Kind::PartialCurriedCXXMethodType:
-  case Kind::CXXOperatorMethodType:
-  case Kind::CurriedCXXOperatorMethodType:
-  case Kind::PartialCurriedCXXOperatorMethodType:
-    // Function types are always passed directly
-    return Direct;
-      
-  case Kind::ClangType:
-  case Kind::Type:
-  case Kind::Discard:
-    // Pass according to the formal type.
-    return SILType::isFormallyReturnedIndirectly(getType(),
-                                                 TC,
-                                                 getGenericSignatureOrNull())
-      ? Indirect : Direct;
-  
-  case Kind::Invalid:
-  case Kind::Tuple:
-  case Kind::ObjCCompletionHandlerArgumentsType:
-    llvm_unreachable("should not get here");
-  }
-}
-
-AbstractionPattern::CallingConventionKind
-AbstractionPattern::getParameterConvention(TypeConverter &TC) const {
-  // Tuples should be destructured.
-  if (isTuple()) {
-    return Destructured;
-  }
-  switch (getKind()) {
-  case Kind::Opaque:
-    // Maximally abstracted values are always passed indirectly.
-    return Indirect;
-  
-  case Kind::OpaqueFunction:
-  case Kind::OpaqueDerivativeFunction:
-  case Kind::PartialCurriedObjCMethodType:
-  case Kind::CurriedObjCMethodType:
-  case Kind::PartialCurriedCFunctionAsMethodType:
-  case Kind::CurriedCFunctionAsMethodType:
-  case Kind::CFunctionAsMethodType:
-  case Kind::ObjCMethodType:
-  case Kind::CXXMethodType:
-  case Kind::CurriedCXXMethodType:
-  case Kind::PartialCurriedCXXMethodType:
-  case Kind::CXXOperatorMethodType:
-  case Kind::CurriedCXXOperatorMethodType:
-  case Kind::PartialCurriedCXXOperatorMethodType:
-    // Function types are always passed directly
-    return Direct;
-      
-  case Kind::ClangType:
-  case Kind::Type:
-  case Kind::Discard:
-    // Pass according to the formal type.
-    return SILType::isFormallyPassedIndirectly(getType(),
-                                                 TC,
-                                                 getGenericSignatureOrNull())
-      ? Indirect : Direct;
-  
-  case Kind::Invalid:
-  case Kind::Tuple:
-  case Kind::ObjCCompletionHandlerArgumentsType:
-    llvm_unreachable("should not get here");
-  }
-}
-
-bool
-AbstractionPattern::operator==(const AbstractionPattern &other) const {
-  if (TheKind != other.TheKind)
-    return false;
-  
-  switch (getKind()) {
-  case Kind::Opaque:
-  case Kind::Invalid:
-  case Kind::OpaqueFunction:
-  case Kind::OpaqueDerivativeFunction:
-    // No additional info to compare.
-    return true;
-
-  case Kind::Tuple:
-    if (getNumTupleElements() != other.getNumTupleElements()) {
-      return false;
-    }
-    for (unsigned i = 0; i < getNumTupleElements(); ++i) {
-      if (getTupleElementType(i) != other.getTupleElementType(i)) {
-        return false;
-      }
-    }
-    return true;
-  
-  case Kind::Type:
-  case Kind::Discard:
-    return OrigType == other.OrigType
-      && GenericSig == other.GenericSig;
-      
-  case Kind::ClangType:
-    return OrigType == other.OrigType
-      && GenericSig == other.GenericSig
-      && ClangType == other.ClangType;
-
-  case Kind::ObjCCompletionHandlerArgumentsType:
-  case Kind::CFunctionAsMethodType:
-  case Kind::CurriedCFunctionAsMethodType:
-  case Kind::PartialCurriedCFunctionAsMethodType:
-    return OrigType == other.OrigType
-      && GenericSig == other.GenericSig
-      && ClangType == other.ClangType
-      && OtherData == other.OtherData;
-
-  case Kind::ObjCMethodType:
-  case Kind::CurriedObjCMethodType:
-  case Kind::PartialCurriedObjCMethodType:
-    return OrigType == other.OrigType
-      && GenericSig == other.GenericSig
-      && ObjCMethod == other.ObjCMethod
-      && OtherData == other.OtherData;
-      
-  case Kind::CXXMethodType:
-  case Kind::CXXOperatorMethodType:
-  case Kind::CurriedCXXMethodType:
-  case Kind::CurriedCXXOperatorMethodType:
-  case Kind::PartialCurriedCXXMethodType:
-  case Kind::PartialCurriedCXXOperatorMethodType:
-    return OrigType == other.OrigType
-      && GenericSig == other.GenericSig
-      && CXXMethod == other.CXXMethod
-      && OtherData == other.OtherData;
-  }
-}

lib/SIL/IR/SILFunctionType.cpp

@@ -2072,8 +2072,7 @@ static CanSILFunctionType getSILFunctionType(
   // for thick or polymorphic functions.  We don't need to worry about
   // non-opaque patterns because the type-checker forbids non-thick
   // function types from having generic parameters or results.
-  if (!constant &&
-      origType.isTypeParameter() &&
+  if (origType.isTypeParameter() &&
       substFnInterfaceType->getExtInfo().getSILRepresentation()
         != SILFunctionType::Representation::Thick &&
       isa<FunctionType>(substFnInterfaceType)) {
@@ -3184,18 +3183,9 @@ static CanSILFunctionType getUncachedSILFunctionTypeForConstant(
       auto proto = constant.getDecl()->getDeclContext()->getSelfProtocolDecl();
       witnessMethodConformance = ProtocolConformanceRef(proto);
     }
-    
-    // Does this constant have a preferred abstraction pattern set?
-    AbstractionPattern origType = [&]{
-      if (auto abstraction = TC.getConstantAbstractionPattern(constant)) {
-        return *abstraction;
-      } else {
-        return AbstractionPattern(origLoweredInterfaceType);
-      }
-    }();
 
     return ::getNativeSILFunctionType(
-        TC, context, origType,
+        TC, context, AbstractionPattern(origLoweredInterfaceType),
         origLoweredInterfaceType, extInfoBuilder, constant, constant, None,
         witnessMethodConformance);
   }

lib/SIL/IR/TypeLowering.cpp

@@ -3491,28 +3491,6 @@ CanSILBoxType TypeConverter::getBoxTypeForEnumElement(
   return boxTy;
 }
 
-Optional<AbstractionPattern>
-TypeConverter::getConstantAbstractionPattern(SILDeclRef constant) {
-  if (auto closure = constant.getAbstractClosureExpr()) {
-    // Using operator[] here creates an entry in the map if one doesn't exist
-    // yet, marking the fact that the lack of abstraction pattern has been
-    // established and cannot be overridden by `setAbstractionPattern` later.
-    return ClosureAbstractionPatterns[closure];
-  }
-  return None;
-}
-
-void TypeConverter::setAbstractionPattern(AbstractClosureExpr *closure,
-                                          AbstractionPattern pattern) {
-  auto existing = ClosureAbstractionPatterns.find(closure);
-  if (existing != ClosureAbstractionPatterns.end()) {
-    assert(*existing->second == pattern
-     && "closure shouldn't be emitted at different abstraction level contexts");
-  } else {
-    ClosureAbstractionPatterns[closure] = pattern;
-  }
-}
-
 static void countNumberOfInnerFields(unsigned &fieldsCount, TypeConverter &TC,
                                      SILType Ty,
                                      TypeExpansionContext expansion) {

lib/SILGen/Conversion.h

@@ -59,11 +59,6 @@ class Conversion {
   static bool isBridgingKind(KindTy kind) {
     return kind <= LastBridgingKind;
   }
-  
-  static bool isReabstractionKind(KindTy kind) {
-    // Update if we end up with more kinds!
-    return !isBridgingKind(kind);
-  }
 
 private:
   KindTy Kind;
@@ -144,10 +139,6 @@ class Conversion {
   bool isBridging() const {
     return isBridgingKind(getKind());
   }
-  
-  bool isReabstraction() const {
-    return isReabstractionKind(getKind());
-  }
 
   AbstractionPattern getReabstractionOrigType() const {
     return Types.get<ReabstractionTypes>(Kind).OrigType;
@@ -273,21 +264,12 @@ class ConvertingInitialization final : public Initialization {
   StateTy getState() const {
     return State;
   }
-  
-  InitializationPtr OwnedSubInitialization;
 
 public:
   ConvertingInitialization(Conversion conversion, SGFContext finalContext)
     : State(Uninitialized), TheConversion(conversion),
       FinalContext(finalContext) {}
 
-  ConvertingInitialization(Conversion conversion,
-                           InitializationPtr subInitialization)
-    : State(Uninitialized), TheConversion(conversion),
-      FinalContext(SGFContext(subInitialization.get())) {
-    OwnedSubInitialization = std::move(subInitialization);
-  }
-  
   /// Return the conversion to apply to the unconverted value.
   const Conversion &getConversion() const {
     return TheConversion;
@@ -346,16 +328,11 @@ class ConvertingInitialization final : public Initialization {
   ConvertingInitialization *getAsConversion() override {
     return this;
   }
-  
-  // Get the abstraction pattern, if any, the value is converted to.
-  Optional<AbstractionPattern> getAbstractionPattern() const override;
 
   // Bookkeeping.
   void finishInitialization(SILGenFunction &SGF) override {
     assert(getState() == Initialized);
     State = Finished;
-    if (OwnedSubInitialization)
-      OwnedSubInitialization->finishInitialization(SGF);
   }
 };
 

lib/SILGen/Initialization.h

@@ -161,16 +161,6 @@ class Initialization {
                      "uninitialized");
   }
 
-  /// The preferred abstraction pattern to initialize with.
-  ///
-  /// Returning something other than None here gives expression emission the
-  /// opportunity to generate the initial value directly at the proper
-  /// abstraction level, avoiding the need for a conversion in some
-  /// circumstances.
-  virtual Optional<AbstractionPattern> getAbstractionPattern() const {
-    return None;
-  }
-
 protected:
   bool EmitDebugValueOnInit = true;
 

lib/SILGen/SGFContext.h

@@ -167,14 +167,6 @@ class SGFContext {
 
     return SGFContext();
   }
-  
-  /// Return the abstraction pattern of the context we're emitting into.
-  Optional<AbstractionPattern> getAbstractionPattern() const {
-    if (auto *init = getEmitInto()) {
-      return init->getAbstractionPattern();
-    }
-    return None;
-  }
 };
 
 using ValueProducerRef =