Merge pull request swiftlang#34358 from jckarter/imported-async-type-lowering

Type lowering and SILGen for imported ObjC async decls.

Author: jckarter

docs/ABI/Mangling.rst

@@ -218,6 +218,8 @@ types where the metadata itself has unknown layout.)
   global ::= global 'Tm'                 // merged function
   global ::= entity                      // some identifiable thing
   global ::= from-type to-type generic-signature? 'TR'  // reabstraction thunk
+  global ::= from-type to-type generic-signature? 'TR'  // reabstraction thunk
+  global ::= impl-function-type 'Tz'     // objc-to-swift-async completion handler block implementation
   global ::= from-type to-type self-type generic-signature? 'Ty'  // reabstraction thunk with dynamic 'Self' capture
   global ::= from-type to-type generic-signature? 'Tr'  // obsolete mangling for reabstraction thunk
   global ::= entity generic-signature? type type* 'TK' // key path getter

include/swift/AST/ForeignAsyncConvention.h

@@ -26,42 +26,51 @@ namespace swift {
 class ForeignAsyncConvention {
 public:
   struct Info {
+  private:
     /// The index of the completion handler parameters.
     unsigned CompletionHandlerParamIndex;
 
     /// When non-zero, indicates which parameter to the completion handler is
     /// the Error? parameter (minus one) that makes this async function also
     /// throwing.
-    unsigned CompletionHandlerErrorParamIndex;
-
+    unsigned CompletionHandlerErrorParamIndexPlusOneOrZero;
+    
+  public:
     Info()
-      : CompletionHandlerParamIndex(0), CompletionHandlerErrorParamIndex(0) { }
+      : CompletionHandlerParamIndex(0),
+        CompletionHandlerErrorParamIndexPlusOneOrZero(0) { }
 
     Info(
         unsigned completionHandlerParamIndex,
         Optional<unsigned> completionHandlerErrorParamIndex)
       : CompletionHandlerParamIndex(completionHandlerParamIndex),
-        CompletionHandlerErrorParamIndex(
+        CompletionHandlerErrorParamIndexPlusOneOrZero(
             completionHandlerErrorParamIndex
               ? *completionHandlerErrorParamIndex + 1
               : 0) {}
 
+    /// Retrieve the index of the completion handler argument in the method's
+    /// parameter list.
+    unsigned completionHandlerParamIndex() const {
+      return CompletionHandlerParamIndex;
+    }
+    
     /// Retrieve the index of the \c Error? parameter in the completion handler's
     /// parameter list. When argument passed to this parameter is non-null, the
     /// provided error will be thrown by the async function.
     Optional<unsigned> completionHandlerErrorParamIndex() const {
-      if (CompletionHandlerErrorParamIndex == 0)
+      if (CompletionHandlerErrorParamIndexPlusOneOrZero == 0)
         return None;
 
-      return CompletionHandlerErrorParamIndex - 1;
+      return CompletionHandlerErrorParamIndexPlusOneOrZero - 1;
     }
 
     /// Whether the async function is throwing due to the completion handler
     /// having an \c Error? parameter.
     ///
     /// Equivalent to \c static_cast<bool>(completionHandlerErrorParamIndex()).
     bool isThrowing() const {
-      return CompletionHandlerErrorParamIndex != 0;
+      return CompletionHandlerErrorParamIndexPlusOneOrZero != 0;
     }
   };
 
@@ -88,7 +97,7 @@ class ForeignAsyncConvention {
   /// Retrieve the index of the completion handler parameter, which will be
   /// erased from the Swift signature of the imported async function.
   unsigned completionHandlerParamIndex() const {
-    return TheInfo.CompletionHandlerParamIndex;
+    return TheInfo.completionHandlerParamIndex();
   }
 
   /// Retrieve the index of the \c Error? parameter in the completion handler's
@@ -108,10 +117,10 @@ class ForeignAsyncConvention {
 
   bool operator==(ForeignAsyncConvention other) const {
     return CompletionHandlerType == other.CompletionHandlerType
-        && TheInfo.CompletionHandlerParamIndex ==
-          other.TheInfo.CompletionHandlerParamIndex
-        && TheInfo.CompletionHandlerErrorParamIndex ==
-          other.TheInfo.CompletionHandlerErrorParamIndex;
+        && TheInfo.completionHandlerParamIndex()
+             == other.TheInfo.completionHandlerParamIndex()
+        && TheInfo.completionHandlerErrorParamIndex()
+             == other.TheInfo.completionHandlerErrorParamIndex();
   }
 
   bool operator!=(ForeignAsyncConvention other) const {

include/swift/AST/ForeignInfo.h

@@ -19,6 +19,7 @@
 #ifndef SWIFT_FOREIGN_INFO_H
 #define SWIFT_FOREIGN_INFO_H
 
+#include "swift/AST/ForeignAsyncConvention.h"
 #include "swift/AST/ForeignErrorConvention.h"
 #include "swift/AST/Decl.h"
 
@@ -27,6 +28,7 @@ namespace swift {
 struct ForeignInfo {
   ImportAsMemberStatus Self;
   Optional<ForeignErrorConvention> Error;
+  Optional<ForeignAsyncConvention> Async;
 };
 
 } // end namespace swift

include/swift/Demangling/DemangleNodes.def

@@ -159,6 +159,7 @@ CONTEXT_NODE(NativePinningMutableAddressor)
 NODE(NominalTypeDescriptor)
 NODE(NonObjCAttribute)
 NODE(Number)
+NODE(ObjCAsyncCompletionHandlerImpl)
 NODE(ObjCAttribute)
 NODE(ObjCBlock)
 NODE(EscapingObjCBlock)

include/swift/SIL/AbstractionPattern.h

@@ -260,46 +260,116 @@ class AbstractionPattern {
     OpaqueDerivativeFunction,
   };
 
-  class EncodedForeignErrorInfo {
+  class EncodedForeignInfo {
     unsigned Value;
+    
+    enum Error_t {
+      Error,
+    };
+    
+    enum Async_t {
+      Async,
+    };
+    
+  public:
+    enum ForeignKind {
+      IsNotForeign,
+      IsError,
+      IsAsync,
+    };
+
+  private:
+    friend AbstractionPattern;
+
+    EncodedForeignInfo() : Value(0) {}
+    EncodedForeignInfo(Error_t,
+                       unsigned errorParameterIndex,
+                       bool replaceParamWithVoid,
+                       bool stripsResultOptionality)
+      : Value(1
+              + (unsigned(IsError) - 1)
+              + (unsigned(stripsResultOptionality) << 1)
+              + (unsigned(replaceParamWithVoid) << 2)
+              + (errorParameterIndex << 3)) {
+        assert(getKind() == IsError);
+        assert(getErrorParamIndex() == errorParameterIndex);
+        assert(hasErrorParameterReplacedWithVoid() == replaceParamWithVoid);
+        assert(errorStripsResultOptionality() == stripsResultOptionality);
+      }
+
+    EncodedForeignInfo(Async_t,
+                       unsigned completionParameterIndex,
+                       Optional<unsigned> completionErrorParameterIndex)
+      : Value(1
+              + (unsigned(IsAsync) - 1)
+              + (unsigned(completionParameterIndex) << 1)
+              + ((completionErrorParameterIndex ? *completionErrorParameterIndex + 1
+                                                : 0) << 21)) {
+        assert(getKind() == IsAsync);
+        assert(getAsyncCompletionHandlerParamIndex() == completionParameterIndex);
+        assert(getAsyncCompletionHandlerErrorParamIndex() == completionErrorParameterIndex);
+      }
 
   public:
-    EncodedForeignErrorInfo() : Value(0) {}
-    EncodedForeignErrorInfo(unsigned errorParameterIndex,
-                            bool replaceParamWithVoid,
-                            bool stripsResultOptionality)
-      : Value(1 +
-              (unsigned(stripsResultOptionality)) +
-              (unsigned(replaceParamWithVoid) << 1) +
-              (errorParameterIndex << 2)) {}
-
-    static EncodedForeignErrorInfo
-    encode(const Optional<ForeignErrorConvention> &foreignError);
+    static EncodedForeignInfo
+    encode(const Optional<ForeignErrorConvention> &foreignError,
+           const Optional<ForeignAsyncConvention> &foreignAsync);
 
     bool hasValue() const { return Value != 0; }
-    bool hasErrorParameter() const { return hasValue(); }
-    bool hasUnreplacedErrorParameter() const {
-      return hasValue() && !isErrorParameterReplacedWithVoid();
+    ForeignKind getKind() const {
+      if (!hasValue())
+        return IsNotForeign;
+      
+      return ForeignKind((Value - 1 & 1) + 1);
+    }
+    
+    bool errorStripsResultOptionality() const {
+      if (getKind() != IsError) return false;
+      return (Value - 1) & 2;
     }
 
-    bool stripsResultOptionality() const {
-      assert(hasValue());
-      return (Value - 1) & 1;
+    bool hasErrorParameterReplacedWithVoid() const {
+      if (getKind() != IsError) return false;
+      return (Value - 1) & 4;
     }
 
-    bool isErrorParameterReplacedWithVoid() const {
-      assert(hasValue());
-      return (Value - 1) & 2;
+    unsigned getErrorParamIndex() const {
+      assert(getKind() == IsError);
+      return (Value - 1) >> 3;
     }
+    
+    unsigned getAsyncCompletionHandlerParamIndex() const {
+      assert(getKind() == IsAsync);
+      return ((Value - 1) >> 1) & 0xFFFFFu;
+    }
+    
+    Optional<unsigned> getAsyncCompletionHandlerErrorParamIndex() const {
+      assert(getKind() == IsAsync);
 
-    unsigned getErrorParameterIndex() const {
-      assert(hasValue());
-      return (Value - 1) >> 2;
+      unsigned encodedValue = (Value - 1) >> 21;
+      if (encodedValue == 0) {
+        return llvm::None;
+      }
+      return encodedValue - 1;
+    }
+
+    unsigned getForeignParamIndex() const {
+      switch (getKind()) {
+      case IsNotForeign:
+        llvm_unreachable("no foreign param");
+      
+      case IsError:
+        return getErrorParamIndex();
+          
+      case IsAsync:
+        return getAsyncCompletionHandlerParamIndex();
+      }
+      llvm_unreachable("uncovered switch");
     }
 
     unsigned getOpaqueValue() const { return Value; }
-    static EncodedForeignErrorInfo fromOpaqueValue(unsigned value) {
-      EncodedForeignErrorInfo result;
+    static EncodedForeignInfo fromOpaqueValue(unsigned value) {
+      EncodedForeignInfo result;
       result.Value = value;
       return result;
     }
@@ -374,7 +444,7 @@ class AbstractionPattern {
     }
   }
 
-  bool hasStoredForeignErrorInfo() const {
+  bool hasStoredForeignInfo() const {
     return hasStoredObjCMethod();
   }
 
@@ -411,7 +481,7 @@ class AbstractionPattern {
 
   void initObjCMethod(CanGenericSignature signature,
                       CanType origType, const clang::ObjCMethodDecl *method,
-                      Kind kind, EncodedForeignErrorInfo errorInfo) {
+                      Kind kind, EncodedForeignInfo errorInfo) {
     initSwiftType(signature, origType, kind);
     ObjCMethod = method;
     OtherData = errorInfo.getOpaqueValue();
@@ -519,7 +589,8 @@ class AbstractionPattern {
   /// Objective-C method.
   static AbstractionPattern
   getCurriedObjCMethod(CanType origType, const clang::ObjCMethodDecl *method,
-                       const Optional<ForeignErrorConvention> &foreignError);
+                       const Optional<ForeignErrorConvention> &foreignError,
+                       const Optional<ForeignAsyncConvention> &foreignAsync);
 
   /// Return an abstraction pattern for the uncurried type of a C function
   /// imported as a method.
@@ -644,7 +715,7 @@ class AbstractionPattern {
   /// Objective-C method.
   static AbstractionPattern
   getCurriedObjCMethod(CanType origType, const clang::ObjCMethodDecl *method,
-                       EncodedForeignErrorInfo errorInfo) {
+                       EncodedForeignInfo errorInfo) {
     assert(isa<AnyFunctionType>(origType));
     AbstractionPattern pattern;
     pattern.initObjCMethod(nullptr, origType, method,
@@ -670,7 +741,7 @@ class AbstractionPattern {
   getPartialCurriedObjCMethod(CanGenericSignature signature,
                               CanType origType,
                               const clang::ObjCMethodDecl *method,
-                              EncodedForeignErrorInfo errorInfo) {
+                              EncodedForeignInfo errorInfo) {
     assert(isa<AnyFunctionType>(origType));
     AbstractionPattern pattern;
     pattern.initObjCMethod(signature, origType, method,
@@ -733,14 +804,15 @@ class AbstractionPattern {
   /// Return an abstraction pattern for the type of an Objective-C method.
   static AbstractionPattern
   getObjCMethod(CanType origType, const clang::ObjCMethodDecl *method,
-                const Optional<ForeignErrorConvention> &foreignError);
+                const Optional<ForeignErrorConvention> &foreignError,
+                const Optional<ForeignAsyncConvention> &foreignAsync);
 
 private:
   /// Return an abstraction pattern for the uncurried type of an
   /// Objective-C method.
   static AbstractionPattern
   getObjCMethod(CanType origType, const clang::ObjCMethodDecl *method,
-                EncodedForeignErrorInfo errorInfo) {
+                EncodedForeignInfo errorInfo) {
     assert(isa<AnyFunctionType>(origType));
     AbstractionPattern pattern;
     pattern.initObjCMethod(nullptr, origType, method, Kind::ObjCMethodType,
@@ -998,9 +1070,9 @@ class AbstractionPattern {
             getKind() == Kind::OpaqueDerivativeFunction);
   }
 
-  EncodedForeignErrorInfo getEncodedForeignErrorInfo() const {
-    assert(hasStoredForeignErrorInfo());
-    return EncodedForeignErrorInfo::fromOpaqueValue(OtherData);
+  EncodedForeignInfo getEncodedForeignInfo() const {
+    assert(hasStoredForeignInfo());
+    return EncodedForeignInfo::fromOpaqueValue(OtherData);
   }
 
   bool hasForeignErrorStrippingResultOptionality() const {
@@ -1029,8 +1101,8 @@ class AbstractionPattern {
     case Kind::PartialCurriedObjCMethodType:
     case Kind::CurriedObjCMethodType:
     case Kind::ObjCMethodType: {
-      auto errorInfo = getEncodedForeignErrorInfo();
-      return (errorInfo.hasValue() && errorInfo.stripsResultOptionality());
+      auto errorInfo = getEncodedForeignInfo();
+      return errorInfo.errorStripsResultOptionality();
     }
     }
     llvm_unreachable("bad kind");
@@ -1203,6 +1275,14 @@ class AbstractionPattern {
       GenericSignature derivativeGenericSignature = GenericSignature(),
       bool makeSelfParamFirst = false);
 
+  /// If this pattern refers to a foreign ObjC method that was imported as async, this returns
+  /// the abstraction pattern for the completion callback with the original ObjC block type.
+  ///
+  /// Otherwise, this produces the default fully-concrete abstraction pattern for the given
+  /// Swift type.
+  AbstractionPattern getObjCMethodAsyncCompletionHandlerType(
+                                     CanType swiftCompletionHandlerType) const;
+  
   void dump() const LLVM_ATTRIBUTE_USED;
   void print(raw_ostream &OS) const;
 };

lib/ClangImporter/ImportName.cpp

@@ -1965,12 +1965,12 @@ ImportedName NameImporter::importNameImpl(const clang::NamedDecl *D,
           method->hasRelatedResultType(), method->isInstanceMethod(),
           result.getAsyncInfo().map(
             [](const ForeignAsyncConvention::Info &info) {
-              return info.CompletionHandlerParamIndex;
+              return info.completionHandlerParamIndex();
             }),
           result.getAsyncInfo().map(
             [&](const ForeignAsyncConvention::Info &info) {
               return method->getDeclName().getObjCSelector().getNameForSlot(
-                  info.CompletionHandlerParamIndex);
+                                            info.completionHandlerParamIndex());
             }),
           *this);
     }

lib/ClangImporter/ImportType.cpp

@@ -2218,7 +2218,7 @@ ImportedType ClangImporter::Implementation::importMethodParamsAndReturnType(
     }
 
     bool paramIsCompletionHandler =
-        asyncInfo && paramIndex == asyncInfo->CompletionHandlerParamIndex;
+        asyncInfo && paramIndex == asyncInfo->completionHandlerParamIndex();
 
     // Import the parameter type into Swift.
 
@@ -2392,8 +2392,8 @@ ImportedType ClangImporter::Implementation::importMethodParamsAndReturnType(
 
   if (asyncInfo) {
     asyncConvention = ForeignAsyncConvention(
-        completionHandlerType, asyncInfo->CompletionHandlerParamIndex,
-        asyncInfo->CompletionHandlerErrorParamIndex);
+        completionHandlerType, asyncInfo->completionHandlerParamIndex(),
+        asyncInfo->completionHandlerErrorParamIndex());
   }
 
   if (errorInfo) {