Temporarily introduce AnyInteriorPointer operand ownership.

This is necessary to fix a recent OSSA bug that breaks common occurrences on
mark_dependence [nonescaping]. Rather than reverting that change above, we make
forward progress toward implicit borrows scopes, as was the original intention.

In the near future, all InteriorPointer instructions will create an implicit
borrow scope. This means we have the option of not emitting extraneous
begin/end_borrow instructions around intructions like ref_element_addr,
open_existential, and project_box. After that, we can also migrate
GuaranteedForwarding instructions like tuple_extract and struct_extract.

Author: atrick

SwiftCompilerSources/Sources/Optimizer/Utilities/OwnershipLiveness.swift

@@ -415,9 +415,11 @@ extension OwnershipUseVisitor {
     case .borrow:
       return visitBorrowingUse(of: operand)
 
-    // TODO: Eventually, visit owned InteriorPointers as implicit borrows.
-    case .interiorPointer, .trivialUse, .endBorrow, .reborrow,
-      .guaranteedForwarding:
+    case .anyInteriorPointer:
+      return visitInteriorPointerUse(of: operand)
+
+    // TODO: .interiorPointer should instead be handled like .anyInteriorPointer.
+    case .interiorPointer, .trivialUse, .endBorrow, .reborrow, .guaranteedForwarding:
       fatalError("ownership incompatible with an owned value");
     }
   }
@@ -449,7 +451,7 @@ extension OwnershipUseVisitor {
     case .borrow:
       return visitBorrowingUse(of: operand)
 
-    case .interiorPointer:
+    case .interiorPointer, .anyInteriorPointer:
       return visitInteriorPointerUse(of: operand)
 
     case .trivialUse, .forwardingConsume, .destroyingConsume:

SwiftCompilerSources/Sources/SIL/Operand.swift

@@ -268,7 +268,11 @@ public enum OperandOwnership {
   /// Interior Pointer. Propagates a trivial value (e.g. address, pointer, or no-escape closure) that depends on the guaranteed value within the base's borrow scope. The verifier checks that all uses of the trivial
   /// value are in scope. (ref_element_addr, open_existential_box)
   case interiorPointer
-  
+
+  /// Any Interior Pointer. An interior pointer that allows any operand ownership. This will be removed as soon as SIL
+  /// migrates away from extraneous borrow scopes.
+  case anyInteriorPointer
+
   /// Forwarded Borrow. Propagates the guaranteed value within the base's borrow scope. (tuple_extract, struct_extract, cast, switch)
   case guaranteedForwarding
 
@@ -282,7 +286,7 @@ public enum OperandOwnership {
     switch self {
     case .nonUse, .trivialUse, .instantaneousUse, .unownedInstantaneousUse,
          .forwardingUnowned, .pointerEscape, .bitwiseEscape, .borrow,
-         .interiorPointer, .guaranteedForwarding:
+         .interiorPointer, .anyInteriorPointer, .guaranteedForwarding:
       return false
     case .destroyingConsume, .forwardingConsume, .endBorrow, .reborrow:
       return true
@@ -313,6 +317,8 @@ public enum OperandOwnership {
       return BridgedOperand.OperandOwnership.ForwardingConsume
     case .interiorPointer:
       return BridgedOperand.OperandOwnership.InteriorPointer
+    case .anyInteriorPointer:
+      return BridgedOperand.OperandOwnership.AnyInteriorPointer
     case .guaranteedForwarding:
       return BridgedOperand.OperandOwnership.GuaranteedForwarding
     case .endBorrow:
@@ -337,6 +343,7 @@ extension Operand {
     case .DestroyingConsume: return .destroyingConsume
     case .ForwardingConsume: return .forwardingConsume
     case .InteriorPointer: return .interiorPointer
+    case .AnyInteriorPointer: return .anyInteriorPointer
     case .GuaranteedForwarding: return .guaranteedForwarding
     case .EndBorrow: return .endBorrow
     case .Reborrow: return .reborrow

include/swift/SIL/OwnershipUseVisitor.h

@@ -397,6 +397,9 @@ bool OwnershipUseVisitor<Impl>::visitOwnedUse(Operand *use) {
     }
     return handleUsePoint(use, UseLifetimeConstraint::LifetimeEnding);
 
+  case OperandOwnership::AnyInteriorPointer:
+    return visitInteriorPointerUses(use);
+
   case OperandOwnership::PointerEscape:
     // TODO: Change ProjectBox ownership to InteriorPointer and allow them to
     // take owned values.
@@ -416,7 +419,7 @@ bool OwnershipUseVisitor<Impl>::visitOwnedUse(Operand *use) {
   case OperandOwnership::Borrow:
     return visitInnerBorrow(use);
 
-  // TODO: Eventually, handle owned InteriorPointers as implicit borrows.
+  // TODO: InteriorPointer should be handled like AnyInteriorPointer.
   case OperandOwnership::InteriorPointer:
   case OperandOwnership::TrivialUse:
   case OperandOwnership::EndBorrow:
@@ -479,6 +482,7 @@ bool OwnershipUseVisitor<Impl>::visitGuaranteedUse(Operand *use) {
     return visitInnerBorrow(use);
 
   case OperandOwnership::InteriorPointer:
+  case OperandOwnership::AnyInteriorPointer:
     return visitInteriorPointerUses(use);
 
   case OperandOwnership::TrivialUse:
@@ -490,8 +494,9 @@ bool OwnershipUseVisitor<Impl>::visitGuaranteedUse(Operand *use) {
 
 template <typename Impl>
 bool OwnershipUseVisitor<Impl>::visitInteriorPointerUses(Operand *use) {
-  assert(use->getOperandOwnership() == OperandOwnership::InteriorPointer ||
-         isa<ProjectBoxInst>(use->getUser()));
+  assert(use->getOperandOwnership() == OperandOwnership::InteriorPointer
+         || use->getOperandOwnership() == OperandOwnership::AnyInteriorPointer
+         || isa<ProjectBoxInst>(use->getUser()));
 
   if (auto scopedAddress = ScopedAddressValue::forUse(use)) {
     // e.g. client may need to insert end_borrow if scopedAddress is a store_borrow.

include/swift/SIL/SILBridging.h

@@ -373,6 +373,7 @@ struct BridgedOperand {
     DestroyingConsume,
     ForwardingConsume,
     InteriorPointer,
+    AnyInteriorPointer,
     GuaranteedForwarding,
     EndBorrow,
     Reborrow

include/swift/SIL/SILBridgingImpl.h

@@ -645,6 +645,8 @@ BridgedOperand::OperandOwnership BridgedOperand::getOperandOwnership() const {
     return OperandOwnership::ForwardingConsume;
   case swift::OperandOwnership::InteriorPointer:
     return OperandOwnership::InteriorPointer;
+  case swift::OperandOwnership::AnyInteriorPointer:
+    return OperandOwnership::AnyInteriorPointer;
   case swift::OperandOwnership::GuaranteedForwarding:
     return OperandOwnership::GuaranteedForwarding;
   case swift::OperandOwnership::EndBorrow:

include/swift/SIL/SILValue.h

@@ -848,6 +848,13 @@ struct OperandOwnership {
     /// value are in scope.
     /// (ref_element_addr, open_existential_box)
     InteriorPointer,
+
+    // TODO: Remove AnyInteriorPointer after fixing
+    // OperandOwnership::getOwnershipConstraint() to allow InteriorPointer
+    // operands to take any operand ownership.  This will prevent useless borrow
+    // scopes from being generated, so it will require some SIL migration. But
+    // all OSSA utilities need to correctly handle interior uses anyway.
+    AnyInteriorPointer,
     /// Forwarded Borrow. Propagates the guaranteed value within the base's
     /// borrow scope.
     /// (tuple_extract, struct_extract, cast, switch)
@@ -942,6 +949,9 @@ inline OwnershipConstraint OperandOwnership::getOwnershipConstraint() {
   case OperandOwnership::DestroyingConsume:
   case OperandOwnership::ForwardingConsume:
     return {OwnershipKind::Owned, UseLifetimeConstraint::LifetimeEnding};
+  case OperandOwnership::AnyInteriorPointer:
+    return {OwnershipKind::Any, UseLifetimeConstraint::NonLifetimeEnding};
+  // TODO: InteriorPointer should be handled like AnyInteriorPointer.
   case OperandOwnership::InteriorPointer:
   case OperandOwnership::GuaranteedForwarding:
     return {OwnershipKind::Guaranteed,
@@ -971,6 +981,7 @@ inline bool canAcceptUnownedValue(OperandOwnership operandOwnership) {
   case OperandOwnership::DestroyingConsume:
   case OperandOwnership::ForwardingConsume:
   case OperandOwnership::InteriorPointer:
+  case OperandOwnership::AnyInteriorPointer:
   case OperandOwnership::GuaranteedForwarding:
   case OperandOwnership::EndBorrow:
   case OperandOwnership::Reborrow:

lib/SIL/IR/SILValue.cpp

@@ -564,6 +564,8 @@ StringRef OperandOwnership::asString() const {
     return "forwarding-consume";
   case OperandOwnership::InteriorPointer:
     return "interior-pointer";
+  case OperandOwnership::AnyInteriorPointer:
+    return "any-interior-pointer";
   case OperandOwnership::GuaranteedForwarding:
     return "guaranteed-forwarding";
   case OperandOwnership::EndBorrow:

lib/SIL/Utils/OwnershipUtils.cpp

@@ -81,7 +81,8 @@ bool swift::findPointerEscape(SILValue original) {
         });
         break;
       }
-      case OperandOwnership::InteriorPointer: {
+      case OperandOwnership::InteriorPointer:
+      case OperandOwnership::AnyInteriorPointer: {
         if (InteriorPointerOperand(use).findTransitiveUses() !=
             AddressUseKind::NonEscaping) {
           return true;
@@ -247,6 +248,7 @@ bool swift::findInnerTransitiveGuaranteedUses(
       break;
 
     case OperandOwnership::InteriorPointer:
+    case OperandOwnership::AnyInteriorPointer:
 #if 0 // FIXME!!! Enable in a following commit that fixes RAUW
       // If our base guaranteed value does not have any consuming uses
       // (consider function arguments), we need to be sure to include interior
@@ -387,6 +389,7 @@ bool swift::findExtendedUsesOfSimpleBorrowedValue(
       break;
 
     case OperandOwnership::InteriorPointer:
+    case OperandOwnership::AnyInteriorPointer:
       if (InteriorPointerOperandKind::get(use) ==
           InteriorPointerOperandKind::Invalid)
         return false;

lib/SIL/Utils/PrunedLiveness.cpp

@@ -299,7 +299,8 @@ PrunedLiveRange<LivenessWithDefs>::updateForBorrowingOperand(Operand *operand) {
 template <typename LivenessWithDefs>
 AddressUseKind PrunedLiveRange<LivenessWithDefs>::checkAndUpdateInteriorPointer(
     Operand *operand) {
-  assert(operand->getOperandOwnership() == OperandOwnership::InteriorPointer);
+  assert(operand->getOperandOwnership() == OperandOwnership::InteriorPointer
+         || operand->getOperandOwnership() == OperandOwnership::AnyInteriorPointer);
 
   if (auto scopedAddress = ScopedAddressValue::forUse(operand)) {
     scopedAddress.visitScopeEndingUses([this](Operand *end) {
@@ -364,6 +365,7 @@ LiveRangeSummary PrunedLiveRange<LivenessWithDefs>::recursivelyUpdateForDef(
       summary.meet(AddressUseKind::PointerEscape);
       break;
     case OperandOwnership::InteriorPointer:
+    case OperandOwnership::AnyInteriorPointer:
       summary.meet(checkAndUpdateInteriorPointer(use));
       break;
     case OperandOwnership::GuaranteedForwarding: {

lib/SIL/Verifier/SILVerifier.cpp

@@ -1458,12 +1458,16 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
                 "kind since guaranteed and owned values can always be passed "
                 "in unowned positions");
 
-        require(operand.getOperandOwnership() !=
-                        OperandOwnership::InteriorPointer ||
-                    InteriorPointerOperandKind::get(&operand) !=
-                        InteriorPointerOperandKind::Invalid,
-                "All operands with InteriorPointer operand ownership should be "
-                "added to the InteriorPointerOperand utility");
+        switch (operand.getOperandOwnership()) {
+        default:
+          break;
+        case OperandOwnership::InteriorPointer:
+        case OperandOwnership::AnyInteriorPointer:
+          require(InteriorPointerOperandKind::get(&operand) !=
+                  InteriorPointerOperandKind::Invalid,
+                  "All operands with InteriorPointer operand ownership should be "
+                  "added to the InteriorPointerOperand utility");
+        }
       }
     }