Fix a pair of IRGen bugs around materializing function type metadata

with sending results:

- The sending result mangling was added in the 6.0 runtime, so demangling
  cannot be used to produce this metadata when targeting an earlier
  runtime.

- The combination of a sending result with isolation requires the 6.1
  runtime to successfully demangle, due to a bug in the 6.0 demangler.

Author: rjmccall

lib/IRGen/GenReflection.cpp

@@ -182,9 +182,10 @@ getRuntimeVersionThatSupportsDemanglingType(CanType type) {
     Swift_5_2,
     Swift_5_5,
     Swift_6_0,
+    Swift_6_1,
 
     // Short-circuit if we find this requirement.
-    Latest = Swift_6_0
+    Latest = Swift_6_1
   };
 
   VersionRequirement latestRequirement = None;
@@ -198,16 +199,29 @@ getRuntimeVersionThatSupportsDemanglingType(CanType type) {
 
   (void) type.findIf([&](CanType t) -> bool {
     if (auto fn = dyn_cast<AnyFunctionType>(t)) {
+      auto isolation = fn->getIsolation();
+      auto sendingResult = fn->hasSendingResult();
+
+      // The Swift 6.1 runtime fixes a bug preventing successful demangling
+      // when @isolated(any) or global actor isolation is combined with a
+      // sending result.
+      if (sendingResult &&
+          (isolation.isErased() || isolation.isGlobalActor()))
+        return addRequirement(Swift_6_1);
+
       // The Swift 6.0 runtime is the first version able to demangle types
-      // that involve typed throws or @isolated(any), or for that matter
-      // represent them at all at runtime.
-      if (!fn.getThrownError().isNull() || fn->getIsolation().isErased())
+      // that involve typed throws, @isolated(any), or a sending result, or
+      // for that matter to represent them at all at runtime.
+      if (!fn.getThrownError().isNull() ||
+          isolation.isErased() ||
+          sendingResult)
         return addRequirement(Swift_6_0);
 
       // The Swift 5.5 runtime is the first version able to demangle types
       // related to concurrency.
-      if (fn->isAsync() || fn->isSendable() ||
-          !fn->getIsolation().isNonIsolated())
+      if (fn->isAsync() ||
+          fn->isSendable() ||
+          !isolation.isNonIsolated())
         return addRequirement(Swift_5_5);
 
       return false;
@@ -255,6 +269,7 @@ getRuntimeVersionThatSupportsDemanglingType(CanType type) {
   });
 
   switch (latestRequirement) {
+  case Swift_6_1: return llvm::VersionTuple(6, 1);
   case Swift_6_0: return llvm::VersionTuple(6, 0);
   case Swift_5_5: return llvm::VersionTuple(5, 5);
   case Swift_5_2: return llvm::VersionTuple(5, 2);

lib/IRGen/MetadataRequest.cpp

@@ -1674,12 +1674,6 @@ static MetadataResponse emitFunctionTypeMetadataRef(IRGenFunction &IGF,
   }
 
   default:
-    assert((!params.empty() || type->isDifferentiable() ||
-            !type->getIsolation().isNonIsolated() ||
-            type->getThrownError()) &&
-           "0 parameter case should be specialized unless it is a "
-           "differentiable function or has a global actor");
-
     llvm::SmallVector<llvm::Value *, 8> arguments;
 
     arguments.push_back(flagsVal);

test/IRGen/isolated_any_metadata.sil

@@ -1,10 +1,13 @@
-// RUN: %swift -emit-ir %s -target x86_64-apple-macosx10.10 -disable-legacy-type-info -parse-stdlib | %FileCheck -DINT=i64 %s -check-prefixes=CHECK,CHECK-ACCESSOR
-// RUN: %swift -emit-ir %s -target x86_64-unknown-linux-gnu -disable-legacy-type-info -parse-stdlib | %FileCheck -DINT=i64 %s -check-prefixes=CHECK,CHECK-DEMANGLE
+// RUN: %swift -emit-ir %s -target x86_64-apple-macosx10.10 -disable-legacy-type-info -parse-stdlib | %FileCheck -DINT=i64 %s -check-prefixes=CHECK,CHECK-ACCESSOR,CHECK-COMBO-ACCESSOR
+// RUN: %swift -emit-ir %s -target x86_64-apple-macos15.0 -disable-legacy-type-info -parse-stdlib | %FileCheck -DINT=i64 %s -check-prefixes=CHECK,CHECK-DEMANGLE,CHECK-COMBO-ACCESSOR
+// RUN: %swift -emit-ir %s -target x86_64-unknown-linux-gnu -disable-legacy-type-info -parse-stdlib | %FileCheck -DINT=i64 %s -check-prefixes=CHECK,CHECK-DEMANGLE,CHECK-COMBO-DEMANGLE
 
 // REQUIRES: concurrency
 
 sil_stage canonical
 
+struct NonSendable {}
+
 // CHECK-LABEL:        define{{.*}} swiftcc ptr @get_metadata
 // CHECK:              entry:
 // CHECK-ACCESSOR-NEXT:  [[T0:%.*]] = call swiftcc %swift.metadata_response @"$syyYbYAcMa"([[INT]] 0)
@@ -22,3 +25,20 @@ entry:
 //   3288334336 == 0xc4000000 == (ExtendedFlags | Sendable | Escaping)
 //   2 == IsolatedAny
 // CHECK-ACCESSOR:         call ptr @swift_getExtendedFunctionTypeMetadata([[INT]] 3288334336, [[INT]] 0, ptr null, ptr null, ptr getelementptr inbounds {{.*}} @"$sytN"{{.*}}), ptr null, i32 2, ptr null)
+
+// CHECK-LABEL:        define{{.*}} swiftcc ptr @get_combo_metadata
+// CHECK:              entry:
+// CHECK-COMBO-ACCESSOR-NEXT: [[T0:%.*]] = call swiftcc %swift.metadata_response @"$s21isolated_any_metadata11NonSendableVyYbYAYTcMa"([[INT]] 0)
+// CHECK-COMBO-ACCESSOR-NEXT:  [[METADATA:%.]] = extractvalue %swift.metadata_response [[T0]], 0
+// CHECK-COMBO-DEMANGLE-NEXT: [[METADATA:%.*]] = call ptr @__swift_instantiateConcreteTypeFromMangledName(ptr @"$s21isolated_any_metadata11NonSendableVyYbYAYTcMD")
+// CHECK-NEXT:           ret ptr [[METADATA]]
+sil @get_combo_metadata : $() -> @thick Any.Type {
+entry:
+  %type = metatype $@thick (@isolated(any) @Sendable () -> sending NonSendable).Type
+  %result = init_existential_metatype %type : $@thick (@isolated(any) @Sendable () -> sending NonSendable).Type, $@thick Any.Type
+  return %result : $@thick Any.Type
+}
+
+// CHECK-COMBO-ACCESSOR-LABEL: define{{.*}} swiftcc %swift.metadata_response @"$s21isolated_any_metadata11NonSendableVyYbYAYTcMa"
+//   18 == 0x12 == IsolatedAny | HasSendingResult
+// CHECK-COMBO-ACCESSOR:         call ptr @swift_getExtendedFunctionTypeMetadata([[INT]] 3288334336, [[INT]] 0, ptr null, ptr null, ptr getelementptr inbounds {{.*}} @"$s21isolated_any_metadata11NonSendableVMf"{{.*}}), ptr null, i32 18, ptr null)