SIL: add matchesActorIsolation

Returns true if the conformance is not isolated or if its isolation matches the isolation `inFunction`.

Author: eeckstein

SwiftCompilerSources/Sources/SIL/ASTExtensions.swift

@@ -54,3 +54,11 @@ extension SubstitutionMap {
     return SubstitutionMap(bridged: method.bridged.getMethodSubstitutions(bridged))
   }
 }
+
+extension Conformance {
+  /// Returns true if the conformance is not isolated or if its isolation matches
+  /// the isolation in `function`.
+  public func matchesActorIsolation(in function: Function) -> Bool {
+    return function.bridged.conformanceMatchesActorIsolation(bridged)
+  }
+}

include/swift/SIL/DynamicCasts.h

@@ -69,6 +69,10 @@ DynamicCastFeasibility classifyDynamicCast(
     bool isSourceTypeExact = false,
     bool isWholeModuleOpts = false);
 
+/// Returns true if the conformance is not isolated or if its isolation matches
+/// the isolation `inFunction`.
+bool matchesActorIsolation(ProtocolConformanceRef conformance, SILFunction *inFunction);
+
 SILValue emitSuccessfulScalarUnconditionalCast(SILBuilder &B, SILLocation loc,
                                                SILDynamicCastInst inst);
 

include/swift/SIL/SILBridging.h

@@ -507,6 +507,7 @@ struct BridgedFunction {
   BRIDGED_INLINE BridgedLinkage getLinkage() const;
   BRIDGED_INLINE void setLinkage(BridgedLinkage linkage) const;
   BRIDGED_INLINE void setIsSerialized(bool isSerialized) const;
+  BRIDGED_INLINE bool conformanceMatchesActorIsolation(BridgedConformance conformance) const;
   bool isTrapNoReturn() const;
   bool isConvertPointerToPointerArgument() const;
   bool isAutodiffVJP() const;

include/swift/SIL/SILBridgingImpl.h

@@ -28,6 +28,7 @@
 #include "swift/Basic/BasicBridging.h"
 #include "swift/Basic/Nullability.h"
 #include "swift/SIL/ApplySite.h"
+#include "swift/SIL/DynamicCasts.h"
 #include "swift/SIL/InstWrappers.h"
 #include "swift/SIL/SILBuilder.h"
 #include "swift/SIL/SILDefaultWitnessTable.h"
@@ -823,6 +824,10 @@ void BridgedFunction::setIsSerialized(bool isSerialized) const {
   getFunction()->setSerializedKind(isSerialized ? swift::IsSerialized : swift::IsNotSerialized);
 }
 
+bool BridgedFunction::conformanceMatchesActorIsolation(BridgedConformance conformance) const {
+  return swift::matchesActorIsolation(conformance.unbridged(), getFunction());
+}
+
 bool BridgedFunction::isResilientNominalDecl(BridgedDeclObj decl) const {
   return decl.getAs<swift::NominalTypeDecl>()->isResilient(getFunction()->getModule().getSwiftModule(),
                                                            getFunction()->getResilienceExpansion());

lib/SIL/Utils/DynamicCasts.cpp

@@ -881,6 +881,25 @@ swift::classifyDynamicCast(ModuleDecl *M,
   return DynamicCastFeasibility::WillFail;
 }
 
+bool swift::matchesActorIsolation(ProtocolConformanceRef conformance, SILFunction *inFunction) {
+  return !conformance.forEachIsolatedConformance([&](ProtocolConformanceRef isolatedConf) -> bool {
+    if (!isolatedConf.isConcrete())
+      return false;
+
+    ActorIsolation isolation = isolatedConf.getConcrete()->getIsolation();
+    if (isolation.isNonisolated())
+      return false;
+
+    if (isolation.isGlobalActor()) {
+      if (auto functionIsolation = inFunction->getActorIsolation()) {
+        if (isolation == functionIsolation.value())
+          return false;
+      }
+    }
+    return true;
+  });
+}
+
 static unsigned getOptionalDepth(CanType type) {
   unsigned depth = 0;
   while (CanType objectType = type.getOptionalObjectType()) {