Merge pull request #25710 from nkcsgexi/ownership-revert

Revert some ownership changes that causes source compatibility failures

Author: nkcsgexi

lib/SIL/LinearLifetimeChecker.cpp

@@ -486,12 +486,11 @@ LinearLifetimeError swift::valueHasLinearLifetime(
   // have been detected by initializing our consuming uses. So we are done.
   if (consumingUses.size() == 1 &&
       consumingUses[0].getParent() == value->getParentBlock()) {
-    // Check if any of our non consuming uses are not in the parent block and
-    // are reachable. We flag those as additional use after frees. Any in the
-    // same block, we would have flagged.
+    // Check if any of our non consuming uses are not in the parent block. We
+    // flag those as additional use after frees. Any in the same block, we would
+    // have flagged.
     if (llvm::any_of(nonConsumingUses, [&](BranchPropagatedUser user) {
-          return user.getParent() != value->getParentBlock() &&
-            !deBlocks.isDeadEnd(user.getParent());
+          return user.getParent() != value->getParentBlock();
         })) {
       state.error.handleUseAfterFree([&] {
         llvm::errs() << "Function: '" << value->getFunction()->getName()

lib/SIL/SILUndef.cpp

@@ -16,15 +16,6 @@
 using namespace swift;
 
 static ValueOwnershipKind getOwnershipKindForUndef(SILType type, const SILFunction &f) {
-  if (type.isAddress()) {
-    // If we have an address only type and we are supposed to use
-    // lowered addresses, return Owned. Otherwise addresses are any.
-    if (type.isAddressOnly(f) && f.getConventions().useLoweredAddresses()) {
-      return ValueOwnershipKind::Owned;
-    }
-    return ValueOwnershipKind::Any;
-  }
-
   if (type.isTrivial(f))
     return ValueOwnershipKind::Any;
   return ValueOwnershipKind::Owned;

lib/SILOptimizer/Mandatory/MarkUninitializedFixup.cpp

@@ -119,7 +119,7 @@ struct MarkUninitializedFixup : SILFunctionTransform {
 
         // Then create the new mark_uninitialized and force all uses of the
         // project_box to go through the new mark_uninitialized.
-        SILBuilderWithScope B(&*std::next(PBI->getIterator()));
+        SILBuilder B(std::next(PBI->getIterator()));
         SILValue Undef = SILUndef::get(PBI->getType(), *PBI->getFunction());
         auto *NewMUI =
             B.createMarkUninitialized(PBI->getLoc(), Undef, MUI->getKind());

lib/SILOptimizer/Transforms/OwnershipModelEliminator.cpp

@@ -382,9 +382,6 @@ struct OwnershipModelEliminator : SILModuleTransform {
       if (SkipTransparent && F.isTransparent())
         continue;
 
-      // Verify here to make sure ownership is correct before we strip.
-      F.verify();
-
       if (stripOwnership(F)) {
         auto InvalidKind =
             SILAnalysis::InvalidationKind::BranchesAndInstructions;

test/SIL/ownership-verifier/undef.sil

@@ -105,10 +105,6 @@ sil @unowned_tuple_user : $@convention(thin) ((Builtin.Int32, Builtin.NativeObje
 sil @produce_owned_optional : $@convention(thin) () -> @owned Optional<Builtin.NativeObject>
 sil @guaranteed_nativeobject_user : $@convention(thin) (@guaranteed Builtin.NativeObject) -> ()
 
-class UnsafeUnownedFieldKlass {
-  unowned(safe) var x: @sil_unowned Builtin.NativeObject
-}
-
 ////////////////
 // Test Cases //
 ////////////////
@@ -1160,26 +1156,3 @@ bb0:
   %9999 = tuple()
   return %9999 : $()
 }
-
-// Make sure that we do not false positive due to borrow users of %12 in an
-// unreachable block.
-sil [ossa] @test_unreachable_users : $@convention(method) (@guaranteed UnsafeUnownedFieldKlass) -> () {
-bb0(%0 : @guaranteed $UnsafeUnownedFieldKlass):
-  %3 = ref_element_addr %0 : $UnsafeUnownedFieldKlass, #UnsafeUnownedFieldKlass.x
-  %4 = load_borrow %3 : $*@sil_unowned Builtin.NativeObject
-  %5 = copy_unowned_value %4 : $@sil_unowned Builtin.NativeObject
-  end_borrow %4 : $@sil_unowned Builtin.NativeObject
-  %12 = begin_borrow %5 : $Builtin.NativeObject
-  %func = function_ref @guaranteed_nativeobject_user : $@convention(thin) (@guaranteed Builtin.NativeObject) -> ()
-  apply %func(%12) : $@convention(thin) (@guaranteed Builtin.NativeObject) -> ()
-  end_borrow %12 : $Builtin.NativeObject
-  destroy_value %5 : $Builtin.NativeObject
-  %36 = tuple ()
-  return %36 : $()
-
-bb1:
-  %func2 = function_ref @guaranteed_nativeobject_user : $@convention(thin) (@guaranteed Builtin.NativeObject) -> ()
-  apply %func2(%12) : $@convention(thin) (@guaranteed Builtin.NativeObject) -> ()
-  unreachable
-}
-