Add SILType::isEscapable

Author: atrick

SwiftCompilerSources/Sources/SIL/Type.swift

@@ -58,6 +58,7 @@ public struct Type : CustomStringConvertible, NoReflectionChildren {
   public var isMetatype: Bool { bridged.isMetatype() }
   public var isNoEscapeFunction: Bool { bridged.isNoEscapeFunction() }
   public var isAsyncFunction: Bool { bridged.isAsyncFunction() }
+  public var isEscapable: Bool { bridged.isEscapable() }
 
   public var canBeClass: BridgedType.TraitResult { bridged.canBeClass() }
 

include/swift/SIL/SILBridging.h

@@ -110,6 +110,7 @@ struct BridgedType {
   BRIDGED_INLINE bool isAsyncFunction() const;
   BRIDGED_INLINE TraitResult canBeClass() const;
   BRIDGED_INLINE bool isMoveOnly() const;
+  BRIDGED_INLINE bool isEscapable() const;
   BRIDGED_INLINE bool isOrContainsObjectiveCClass() const;
   BRIDGED_INLINE bool isBuiltinInteger() const;
   BRIDGED_INLINE bool isBuiltinFloat() const;

include/swift/SIL/SILBridgingImpl.h

@@ -140,6 +140,10 @@ bool BridgedType::isMoveOnly() const {
   return get().isMoveOnly();
 }
 
+bool BridgedType::isEscapable() const {
+  return get().isEscapable();
+}
+
 bool BridgedType::isOrContainsObjectiveCClass() const {
   return get().isOrContainsObjectiveCClass();
 }

include/swift/SIL/SILType.h

@@ -881,6 +881,10 @@ class SILType {
   ProtocolConformanceRef conformsToProtocol(SILFunction *fn,
                                             ProtocolDecl *protocol) const;
 
+  /// False if SILValues of this type cannot be used outside the scope of their
+  /// lifetime dependence.
+  bool isEscapable() const;
+
   //
   // Accessors for types used in SIL instructions:
   //

lib/SIL/IR/SILType.cpp

@@ -1130,6 +1130,13 @@ bool SILType::isMarkedAsImmortal() const {
   return false;
 }
 
+bool SILType::isEscapable() const {
+  if (auto *nom = getASTType().getAnyNominal())
+    return nom->isEscapable();
+
+  return true;
+}
+
 intptr_t SILType::getFieldIdxOfNominalType(StringRef fieldName) const {
   auto *nominal = getNominalOrBoundGenericNominal();
   if (!nominal)