[ownership] When deserializing a SILFunction, match the ownership of …

include/swift/SIL/SILFunction.h

@@ -318,6 +318,12 @@ class SILFunction
          SILFunction *InsertBefore = nullptr,
          const SILDebugScope *DebugScope = nullptr);
 
+  /// Set has ownership to the given value. True means that the function has
+  /// ownership, false means it does not.
+  ///
+  /// Only for use by FunctionBuilders!
+  void setHasOwnership(bool newValue) { HasOwnership = newValue; }
+
 public:
   ~SILFunction();
 
@@ -444,9 +450,7 @@ class SILFunction
 
   /// Sets the HasOwnership flag to false. This signals to SIL that no
   /// ownership instructions should be in this function any more.
-  void setOwnershipEliminated() {
-    HasOwnership = false;
-  }
+  void setOwnershipEliminated() { setHasOwnership(false); }
 
   /// Returns true if this function was deserialized from canonical
   /// SIL. (.swiftmodule files contain canonical SIL; .sib files may be 'raw'

include/swift/SIL/SILFunctionBuilder.h

@@ -106,7 +106,15 @@ class SILFunctionBuilder {
 
   void addFunctionAttributes(SILFunction *F, DeclAttributes &Attrs,
                              SILModule &M, SILDeclRef constant = SILDeclRef());
+
+  /// We do not expose this to everyone, instead we allow for our users to opt
+  /// into this if they need to. Please do not do this in general! We only want
+  /// to use this when deserializing a function body.
+  static void setHasOwnership(SILFunction *F, bool newValue) {
+    F->setHasOwnership(newValue);
+  }
 };
+
 } // namespace swift
 
 #endif

lib/Serialization/DeserializeSIL.cpp

@@ -545,6 +545,8 @@ SILDeserializer::readSILFunctionChecked(DeclID FID, SILFunction *existingFn,
   if (SILMod.isSerialized())
     isSerialized = IsNotSerialized;
 
+  SILSerializationFunctionBuilder builder(SILMod);
+
   // If we have an existing function, verify that the types match up.
   if (fn) {
     if (fn->getLoweredType() != ty) {
@@ -576,7 +578,6 @@ SILDeserializer::readSILFunctionChecked(DeclID FID, SILFunction *existingFn,
 
   } else {
     // Otherwise, create a new function.
-    SILSerializationFunctionBuilder builder(SILMod);
     fn = builder.createDeclaration(name, ty, loc);
     fn->setLinkage(linkage.getValue());
     fn->setTransparent(IsTransparent_t(isTransparent == 1));
@@ -599,19 +600,22 @@ SILDeserializer::readSILFunctionChecked(DeclID FID, SILFunction *existingFn,
     for (auto ID : SemanticsIDs) {
       fn->addSemanticsAttr(MF->getIdentifierText(ID));
     }
-    if (!hasQualifiedOwnership)
-      fn->setOwnershipEliminated();
     if (Callback) Callback->didDeserialize(MF->getAssociatedModule(), fn);
   }
+
+  // First before we do /anything/ validate that our function is truly empty.
+  assert(fn->empty() && "SILFunction to be deserialized starts being empty.");
+
+  // Given that our original function was empty, just match the deserialized
+  // function. Ownership doesn't really have a meaning without a body.
+  builder.setHasOwnership(fn, hasQualifiedOwnership);
+
   // Mark this function as deserialized. This avoids rerunning diagnostic
   // passes. Certain passes in the madatory pipeline may not work as expected
   // after arbitrary optimization and lowering.
   if (!MF->IsSIB)
     fn->setWasDeserializedCanonical();
 
-  assert(fn->empty() &&
-         "SILFunction to be deserialized starts being empty.");
-
   fn->setBare(IsBare);
   const SILDebugScope *DS = fn->getDebugScope();
   if (!DS) {
@@ -675,9 +679,6 @@ SILDeserializer::readSILFunctionChecked(DeclID FID, SILFunction *existingFn,
          && "function already has context generic params?!");
   if (genericEnv)
     fn->setGenericEnvironment(genericEnv);
-  if (!hasQualifiedOwnership) {
-    fn->setOwnershipEliminated();
-  }
 
   scratch.clear();
   kind = SILCursor.readRecord(entry.ID, scratch);

lib/Serialization/SILSerializationFunctionBuilder.h

@@ -33,6 +33,10 @@ class LLVM_LIBRARY_VISIBILITY SILSerializationFunctionBuilder {
         IsNotSerialized, IsNotDynamic, ProfileCounter(), IsNotThunk,
         SubclassScope::NotApplicable);
   }
+
+  void setHasOwnership(SILFunction *f, bool newValue) {
+    builder.setHasOwnership(f, newValue);
+  }
 };
 
 } // namespace swift