MoveOnlyAddressChecker: More robust checking for consume-during-borrow.

- While an opaque borrow access occurs to part of a value, the entire scope of
  the access needs to be treated as a liveness range, so add the `EndAccess`es
  to the liveness range.
- The SIL verifier may crash the compiler on SILGen-generated code when the
  developer's source contains consume-during-borrow code patterns. Allow
  `load_borrow` instructions to be marked `[unchecked]`, which suppresses
  verifier checks until the move checker runs and gets a chance to properly
  diagnose these errors.

Fixes rdar:https://124360175.

include/swift/SIL/SILInstruction.h

@@ -4588,14 +4588,29 @@ class EndBorrowInst;
 /// instruction in its use-def list.
 class LoadBorrowInst :
  public UnaryInstructionBase<SILInstructionKind::LoadBorrowInst,
- SingleValueInstruction> {
+ SingleValueInstruction>
+{
  friend class SILBuilder;
 
+ bool Unchecked = false;
+
 public:
  LoadBorrowInst(SILDebugLocation DebugLoc, SILValue LValue)
  : UnaryInstructionBase(DebugLoc, LValue,
  LValue->getType().getObjectType()) {}
 
+ // True if the invariants on `load_borrow` have not been checked and
+ // should not be strictly enforced.
+ //
+ // This can only occur during raw SIL before move-only checking occurs.
+ // Developers can write incorrect code using noncopyable types that
+ // consumes or mutates a memory location while that location is borrowed,
+ // but the move-only checker must diagnose those problems before canonical
+ // SIL is formed.
+ bool isUnchecked() const { return Unchecked; }
+
+ void setUnchecked(bool value) { Unchecked = value; }
+
  using EndBorrowRange =
  decltype(std::declval<ValueBase>().getUsersOfType<EndBorrowInst>());
 

lib/SIL/IR/SILPrinter.cpp

@@ -1738,6 +1738,9 @@ class SILPrinter : public SILInstructionVisitor<SILPrinter> {
  }
 
  void visitLoadBorrowInst(LoadBorrowInst *LBI) {
+ if (LBI->isUnchecked()) {
+ *this << "[unchecked] ";
+ }
  *this << getIDAndType(LBI->getOperand());
  }
 

lib/SIL/Parser/ParseSIL.cpp

@@ -3727,12 +3727,28 @@ bool SILParser::parseSpecificSILInstruction(SILBuilder &B,
 
  case SILInstructionKind::LoadBorrowInst: {
  SourceLoc AddrLoc;
+
+ bool IsUnchecked = false;
+ StringRef AttrName;
+ SourceLoc AttrLoc;
+ if (parseSILOptional(AttrName, AttrLoc, *this)) {
+ if (AttrName == "unchecked") {
+ IsUnchecked = true;
+ } else {
+ P.diagnose(InstLoc.getSourceLoc(),
+ diag::sil_invalid_attribute_for_instruction, AttrName,
+ "load_borrow");
+ return true;
+ }
+ }
 
  if (parseTypedValueRef(Val, AddrLoc, B) ||
  parseSILDebugLocation(InstLoc, B))
  return true;
 
- ResultVal = B.createLoadBorrow(InstLoc, Val);
+ auto LB = B.createLoadBorrow(InstLoc, Val);
+ LB->setUnchecked(IsUnchecked);
+ ResultVal = LB;
  break;
  }
 

lib/SIL/Verifier/MemoryLifetimeVerifier.cpp

@@ -781,7 +781,9 @@ void MemoryLifetimeVerifier::checkBlock(SILBasicBlock *block, Bits &bits) {
  requireBitsSet(bits, sbi->getDest(), &I);
  locations.clearBits(bits, sbi->getDest());
  } else if (auto *lbi = dyn_cast<LoadBorrowInst>(ebi->getOperand())) {
- requireBitsSet(bits, lbi->getOperand(), &I);
+ if (!lbi->isUnchecked()) {
+ requireBitsSet(bits, lbi->getOperand(), &I);
+ }
  }
  break;
  }

lib/SIL/Verifier/SILVerifier.cpp

@@ -2626,8 +2626,13 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
  requireSameType(LBI->getOperand()->getType().getObjectType(),
  LBI->getType(),
  "Load operand type and result type mismatch");
- require(loadBorrowImmutabilityAnalysis.isImmutable(LBI),
- "Found load borrow that is invalidated by a local write?!");
+ if (LBI->isUnchecked()) {
+ require(LBI->getModule().getStage() == SILStage::Raw,
+ "load_borrow can only be [unchecked] in raw SIL");
+ } else {
+ require(loadBorrowImmutabilityAnalysis.isImmutable(LBI),
+ "Found load borrow that is invalidated by a local write?!");
+ }
  }
 
  void checkBeginBorrowInst(BeginBorrowInst *bbi) {

lib/SILGen/SILGenLValue.cpp

@@ -1231,6 +1231,11 @@ namespace {
  return base;
  }
  auto result = SGF.B.createLoadBorrow(loc, base.getValue());
+ // Mark the load_borrow as unchecked. We can't stop the source code from
+ // trying to mutate or consume the same lvalue during this borrow, so
+ // we don't want verifiers to trip before the move checker gets a chance
+ // to diagnose these situations.
+ result->setUnchecked(true);
  return SGF.emitFormalEvaluationManagedBorrowedRValueWithCleanup(loc,
  base.getValue(), result);
  }

lib/SILOptimizer/Mandatory/MoveOnlyAddressCheckerUtils.cpp

@@ -1257,23 +1257,29 @@ void UseState::initializeLiveness(
  << *livenessInstAndValue.first;
  liveness.print(llvm::dbgs()));
  }
+
+ auto updateForLivenessAccess = [&](BeginAccessInst *beginAccess,
+ const SmallBitVector &livenessMask) {
+ for (auto *endAccess : beginAccess->getEndAccesses()) {
+ liveness.updateForUse(endAccess, livenessMask, false /*lifetime ending*/);
+ }
+ };
 
  for (auto livenessInstAndValue : nonconsumingUses) {
  if (auto *lbi = dyn_cast<LoadBorrowInst>(livenessInstAndValue.first)) {
  auto accessPathWithBase =
  AccessPathWithBase::computeInScope(lbi->getOperand());
  if (auto *beginAccess =
- dyn_cast<BeginAccessInst>(accessPathWithBase.base)) {
- for (auto *endAccess : beginAccess->getEndAccesses()) {
- liveness.updateForUse(endAccess, livenessInstAndValue.second,
- false /*lifetime ending*/);
- }
+ dyn_cast_or_null<BeginAccessInst>(accessPathWithBase.base)) {
+ updateForLivenessAccess(beginAccess, livenessInstAndValue.second);
  } else {
  for (auto *ebi : lbi->getEndBorrows()) {
  liveness.updateForUse(ebi, livenessInstAndValue.second,
  false /*lifetime ending*/);
  }
  }
+ } else if (auto *bai = dyn_cast<BeginAccessInst>(livenessInstAndValue.first)) {
+ updateForLivenessAccess(bai, livenessInstAndValue.second);
  } else {
  liveness.updateForUse(livenessInstAndValue.first,
  livenessInstAndValue.second,

lib/SILOptimizer/Mandatory/MoveOnlyChecker.cpp

@@ -203,6 +203,22 @@ void MoveOnlyChecker::checkAddresses() {
 
 namespace {
 
+static bool canonicalizeLoadBorrows(SILFunction *F) {
+ bool changed = false;
+ for (auto &block : *F) {
+ for (auto &inst : block) {
+ if (auto *lbi = dyn_cast<LoadBorrowInst>(&inst)) {
+ if (lbi->isUnchecked()) {
+ changed = true;
+ lbi->setUnchecked(false);
+ }
+ }
+ }
+ }
+
+ return changed;
+}
+
 class MoveOnlyCheckerPass : public SILFunctionTransform {
  void run() override {
  auto *fn = getFunction();
@@ -217,8 +233,11 @@ class MoveOnlyCheckerPass : public SILFunctionTransform {
  // If an earlier pass told use to not emit diagnostics for this function,
  // clean up any copies, invalidate the analysis, and return early.
  if (fn->hasSemanticsAttr(semantics::NO_MOVEONLY_DIAGNOSTICS)) {
- if (cleanupNonCopyableCopiesAfterEmittingDiagnostic(getFunction()))
+ bool didChange = canonicalizeLoadBorrows(fn);
+ didChange |= cleanupNonCopyableCopiesAfterEmittingDiagnostic(getFunction());
+ if (didChange) {
  invalidateAnalysis(SILAnalysis::InvalidationKind::Instructions);
+ }
  return;
  }
 
@@ -241,6 +260,11 @@ class MoveOnlyCheckerPass : public SILFunctionTransform {
  checker.diagnosticEmitter);
  }
 
+ // Remaining borrows
+ // should be correctly immutable. We can canonicalize any remaining
+ // `load_borrow [unchecked]` instructions.
+ checker.madeChange |= canonicalizeLoadBorrows(fn);
+
  checker.madeChange |=
  cleanupNonCopyableCopiesAfterEmittingDiagnostic(fn);
 

lib/Serialization/DeserializeSIL.cpp

@@ -2257,7 +2257,6 @@ bool SILDeserializer::readSILInstruction(SILFunction *Fn,
  UNARY_INSTRUCTION(FixLifetime)
  UNARY_INSTRUCTION(EndLifetime)
  UNARY_INSTRUCTION(CopyBlock)
- UNARY_INSTRUCTION(LoadBorrow)
  UNARY_INSTRUCTION(EndInitLetRef)
  REFCOUNTING_INSTRUCTION(StrongRetain)
  REFCOUNTING_INSTRUCTION(StrongRelease)
@@ -2269,6 +2268,17 @@ bool SILDeserializer::readSILInstruction(SILFunction *Fn,
 #undef UNARY_INSTRUCTION
 #undef REFCOUNTING_INSTRUCTION
 
+ case SILInstructionKind::LoadBorrowInst: {
+ assert(RecordKind == SIL_ONE_OPERAND && "Layout should be OneOperand.");
+ auto LB = Builder.createLoadBorrow(
+ Loc, getLocalValue(Builder.maybeGetFunction(), ValID,
+ getSILType(MF->getType(TyID),
+ (SILValueCategory)TyCategory, Fn)));
+ LB->setUnchecked(Attr != 0);
+ ResultInst = LB;
+ break;
+ }
+
  case SILInstructionKind::BeginBorrowInst: {
  assert(RecordKind == SIL_ONE_OPERAND && "Layout should be OneOperand.");
  auto isLexical = IsLexical_t(Attr & 0x1);

lib/Serialization/SerializeSIL.cpp

@@ -1601,6 +1601,8 @@ void SILSerializer::writeSILInstruction(const SILInstruction &SI) {
  } else if (auto *I = dyn_cast<CopyableToMoveOnlyWrapperValueInst>(&SI)) {
  Attr = I->getForwardingOwnershipKind() == OwnershipKind::Owned ? true
  : false;
+ } else if (auto *LB = dyn_cast<LoadBorrowInst>(&SI)) {
+ Attr = LB->isUnchecked();
  }
  writeOneOperandLayout(SI.getKind(), Attr, SI.getOperand(0));
  break;

test/SILGen/moveonly.swift

@@ -974,7 +974,7 @@ public struct LoadableSubscriptGetOnlyTester : ~Copyable {
 // The get call
 // CHECK: [[ACCESS:%.*]] = begin_access [read] [unknown] [[PROJECT]]
 // CHECK: [[MARK:%.*]] = mark_unresolved_non_copyable_value [no_consume_or_assign] [[ACCESS]]
-// CHECK: [[LOAD_BORROW:%.*]] = load_borrow [[MARK]]
+// CHECK: [[LOAD_BORROW:%.*]] = load_borrow [unchecked] [[MARK]]
 // CHECK: [[TEMP:%.*]] = alloc_stack $AddressOnlyProtocol
 // CHECK: [[TEMP_MARK:%.*]] = mark_unresolved_non_copyable_value [consumable_and_assignable] [[TEMP]]
 // CHECK: apply {{%.*}}([[TEMP_MARK]], {{%.*}}, [[LOAD_BORROW]])
@@ -989,7 +989,7 @@ public struct LoadableSubscriptGetOnlyTester : ~Copyable {
 // CHECK: [[M2_PROJECT:%.*]] = project_box [[M2_BORROW]]
 // CHECK: [[ACCESS:%.*]] = begin_access [read] [unknown] [[PROJECT]]
 // CHECK: [[MARK:%.*]] = mark_unresolved_non_copyable_value [no_consume_or_assign] [[ACCESS]]
-// CHECK: [[LOAD:%.*]] = load_borrow [[MARK]]
+// CHECK: [[LOAD:%.*]] = load_borrow [unchecked] [[MARK]]
 // CHECK: apply {{%.*}}([[M2_PROJECT]], {{%.*}}, [[LOAD]])
 // CHECK: end_borrow [[LOAD]]
 // CHECK: end_access [[ACCESS]]
@@ -1030,7 +1030,7 @@ public func testSubscriptGetOnly_BaseLoadable_ResultAddressOnly_Let() {
 // CHECK: [[MARK:%.*]] = mark_unresolved_non_copyable_value [consumable_and_assignable] [[ARG]]
 //
 // CHECK: [[ACCESS:%.*]] = begin_access [read] [unknown] [[MARK]]
-// CHECK: [[LOAD_BORROW:%.*]] = load_borrow [[ACCESS]]
+// CHECK: [[LOAD_BORROW:%.*]] = load_borrow [unchecked] [[ACCESS]]
 // CHECK: [[TEMP:%.*]] = alloc_stack $AddressOnlyProtocol
 // CHECK: [[TEMP_MARK:%.*]] = mark_unresolved_non_copyable_value [consumable_and_assignable] [[TEMP]]
 // CHECK: apply {{%.*}}([[TEMP_MARK]], {{%.*}}, [[LOAD_BORROW]])
@@ -1049,7 +1049,7 @@ public func testSubscriptGetOnly_BaseLoadable_ResultAddressOnly_InOut(m: inout L
 // The get call
 // CHECK: [[ACCESS:%.*]] = begin_access [read] [dynamic] [[GLOBAL_ADDR]]
 // CHECK: [[MARK:%.*]] = mark_unresolved_non_copyable_value [no_consume_or_assign] [[ACCESS]]
-// CHECK: [[LOAD_BORROW:%.*]] = load_borrow [[MARK]]
+// CHECK: [[LOAD_BORROW:%.*]] = load_borrow [unchecked] [[MARK]]
 // CHECK: [[TEMP:%.*]] = alloc_stack $AddressOnlyProtocol
 // CHECK: [[TEMP_MARK:%.*]] = mark_unresolved_non_copyable_value [consumable_and_assignable] [[TEMP]]
 // CHECK: apply {{%.*}}([[TEMP_MARK]], {{%.*}}, [[LOAD_BORROW]])
@@ -1078,7 +1078,7 @@ public struct LoadableSubscriptGetOnlyTesterNonCopyableStructParent : ~Copyable
 // CHECK: [[ACCESS:%.*]] = begin_access [read] [unknown] [[PROJECT]]
 // CHECK: [[MARK:%.*]] = mark_unresolved_non_copyable_value [no_consume_or_assign] [[ACCESS]]
 // CHECK: [[GEP:%.*]] = struct_element_addr [[MARK]]
-// CHECK: [[LOAD_BORROW:%.*]] = load_borrow [[GEP]]
+// CHECK: [[LOAD_BORROW:%.*]] = load_borrow [unchecked] [[GEP]]
 // CHECK: [[TEMP:%.*]] = alloc_stack $AddressOnlyProtocol
 // CHECK: [[TEMP_MARK:%.*]] = mark_unresolved_non_copyable_value [consumable_and_assignable] [[TEMP]]
 // CHECK: apply {{%.*}}([[TEMP_MARK]], {{%.*}}, [[LOAD_BORROW]])
@@ -1090,7 +1090,7 @@ public struct LoadableSubscriptGetOnlyTesterNonCopyableStructParent : ~Copyable
 // The second get call.
 // CHECK: [[ACCESS:%.*]] = begin_access [read] [unknown] [[PROJECT]]
 // CHECK: [[MARK:%.*]] = mark_unresolved_non_copyable_value [no_consume_or_assign] [[ACCESS]]
-// CHECK: [[LOAD_BORROW:%.*]] = load_borrow [[MARK]]
+// CHECK: [[LOAD_BORROW:%.*]] = load_borrow [unchecked] [[MARK]]
 // CHECK: [[VALUE:%.*]] = apply {{%.*}}([[LOAD_BORROW]])
 //
 // CHECK: [[BORROWED_VALUE:%.*]] = begin_borrow [[VALUE]]
@@ -1137,7 +1137,7 @@ public func testSubscriptGetOnlyThroughNonCopyableParentStruct_BaseLoadable_Resu
 //
 // CHECK: [[ACCESS:%.*]] = begin_access [read] [unknown] [[MARK]]
 // CHECK: [[GEP:%.*]] = struct_element_addr [[ACCESS]]
-// CHECK: [[LOAD:%.*]] = load_borrow [[GEP]]
+// CHECK: [[LOAD:%.*]] = load_borrow [unchecked] [[GEP]]
 // CHECK: [[TEMP:%.*]] = alloc_stack $AddressOnlyProtocol
 // CHECK: [[TEMP_MARK:%.*]] = mark_unresolved_non_copyable_value [consumable_and_assignable] [[TEMP]]
 // CHECK: apply {{%.*}}([[TEMP_MARK]], {{%.*}}, [[LOAD]])
@@ -1155,7 +1155,7 @@ public func testSubscriptGetOnlyThroughNonCopyableParentStruct_BaseLoadable_Resu
 // CHECK: [[ACCESS:%.*]] = begin_access [read] [dynamic] [[GLOBAL]]
 // CHECK: [[MARK:%.*]] = mark_unresolved_non_copyable_value [no_consume_or_assign] [[ACCESS]]
 // CHECK: [[GEP:%.*]] = struct_element_addr [[MARK]]
-// CHECK: [[LOAD:%.*]] = load_borrow [[GEP]]
+// CHECK: [[LOAD:%.*]] = load_borrow [unchecked] [[GEP]]
 // CHECK: [[TEMP:%.*]] = alloc_stack $AddressOnlyProtocol
 // CHECK: [[TEMP_MARK:%.*]] = mark_unresolved_non_copyable_value [consumable_and_assignable] [[TEMP]]
 // CHECK: apply {{%.*}}([[TEMP_MARK]], {{%.*}}, [[LOAD]])
@@ -1192,7 +1192,7 @@ public class LoadableSubscriptGetOnlyTesterClassParent {
 // CHECK: [[TEMP:%.*]] = alloc_stack $LoadableSubscriptGetOnlyTester
 // CHECK: [[TEMP_MARK:%.*]] = mark_unresolved_non_copyable_value [no_consume_or_assign] [[TEMP]]
 // CHECK: [[TEMP_MARK_BORROW:%.*]] = store_borrow [[CORO_RESULT]] to [[TEMP_MARK]]
-// CHECK: [[LOAD:%.*]] = load_borrow [[TEMP_MARK_BORROW]]
+// CHECK: [[LOAD:%.*]] = load_borrow [unchecked] [[TEMP_MARK_BORROW]]
 // CHECK: [[TEMP2:%.*]] = alloc_stack $
 // CHECK: [[TEMP2_MARK:%.*]] = mark_unresolved_non_copyable_value [consumable_and_assignable] [[TEMP2]]
 // CHECK: apply {{%.*}}([[TEMP2_MARK]], {{%.*}}, [[LOAD]])
@@ -1214,7 +1214,7 @@ public class LoadableSubscriptGetOnlyTesterClassParent {
 // CHECK: [[TEMP_MARK:%.*]] = mark_unresolved_non_copyable_value [no_consume_or_assign] [[TEMP]]
 // CHECK: [[TEMP_MARK_BORROW:%.*]] = store_borrow [[CORO_RESULT]] to [[TEMP_MARK]]
 // CHECK: [[GEP:%.*]] = struct_element_addr [[TEMP_MARK_BORROW]]
-// CHECK: [[LOAD:%.*]] = load_borrow [[GEP]]
+// CHECK: [[LOAD:%.*]] = load_borrow [unchecked] [[GEP]]
 // CHECK: [[TEMP2:%.*]] = alloc_stack $
 // CHECK: [[TEMP2_MARK:%.*]] = mark_unresolved_non_copyable_value [consumable_and_assignable] [[TEMP2]]
 // CHECK: apply {{%.*}}([[TEMP2_MARK]], {{%.*}}, [[LOAD]])
@@ -1226,7 +1226,7 @@ public class LoadableSubscriptGetOnlyTesterClassParent {
 // Third read.
 //
 // CHECK: [[ACCESS:%.*]] = begin_access [read] [unknown] [[PROJECT]]
-// CHECK: [[LOAD:%.*]] = load_borrow [[ACCESS]]
+// CHECK: [[LOAD:%.*]] = load_borrow [unchecked] [[ACCESS]]
 // CHECK: ([[CORO_RESULT_ORIG:%.*]], [[CORO_TOKEN:%.*]]) = begin_apply {{%.*}}([[LOAD]])
 // CHECK: [[CORO_RESULT_CP:%.*]] = copy_value [[CORO_RESULT_ORIG]]
 // CHECK: [[CORO_RESULT_MK:%.*]] = mark_unresolved_non_copyable_value [no_consume_or_assign] [[CORO_RESULT_CP]]
@@ -1455,7 +1455,7 @@ public struct LoadableSubscriptGetSetTesterNonCopyableStructParent : ~Copyable {
 // The second get call.
 // CHECK: [[ACCESS:%.*]] = begin_access [read] [unknown] [[PROJECT]]
 // CHECK: [[MARK:%.*]] = mark_unresolved_non_copyable_value [no_consume_or_assign] [[ACCESS]]
-// CHECK: [[LOAD_BORROW:%.*]] = load_borrow [[MARK]]
+// CHECK: [[LOAD_BORROW:%.*]] = load_borrow [unchecked] [[MARK]]
 // CHECK: [[VALUE:%.*]] = apply {{%.*}}([[LOAD_BORROW]])
 // CHECK: [[BORROWED_VALUE:%.*]] = begin_borrow [[VALUE]]
 // CHECK: [[TEMP:%.*]] = alloc_stack $AddressOnlyProtocol
@@ -1652,7 +1652,7 @@ public class LoadableSubscriptGetSetTesterClassParent {
 // Third read.
 //
 // CHECK: [[ACCESS:%.*]] = begin_access [read] [unknown] [[PROJECT]]
-// CHECK: [[CLASS:%.*]] = load_borrow [[ACCESS]]
+// CHECK: [[CLASS:%.*]] = load_borrow [unchecked] [[ACCESS]]
 // CHECK: ([[CORO_RESULT_ORIG:%.*]], [[CORO_TOKEN:%.*]]) = begin_apply {{%.*}}([[CLASS]])
 // CHECK: [[CORO_RESULT_CP:%.*]] = copy_value [[CORO_RESULT_ORIG]]
 // CHECK: [[CORO_RESULT_MK:%.*]] = mark_unresolved_non_copyable_value [no_consume_or_assign] [[CORO_RESULT_CP]]
@@ -1911,7 +1911,7 @@ public struct LoadableSubscriptReadModifyTesterNonCopyableStructParent : ~Copyab
 // The second get call.
 // CHECK: [[ACCESS:%.*]] = begin_access [read] [unknown] [[PROJECT]]
 // CHECK: [[MARK:%.*]] = mark_unresolved_non_copyable_value [no_consume_or_assign] [[ACCESS]]
-// CHECK: [[LOAD_BORROW:%.*]] = load_borrow [[MARK]]
+// CHECK: [[LOAD_BORROW:%.*]] = load_borrow [unchecked] [[MARK]]
 // CHECK: [[VALUE:%.*]] = apply {{%.*}}([[LOAD_BORROW]])
 // CHECK: [[BORROWED_VALUE:%.*]] = begin_borrow [[VALUE]]
 // CHECK: ([[CORO_RESULT_ORIG:%.*]], [[CORO_TOKEN:%.*]]) = begin_apply {{%.*}}({{%.*}}, [[BORROWED_VALUE]])
@@ -2092,7 +2092,7 @@ public class LoadableSubscriptReadModifyTesterClassParent {
 // Third read.
 //
 // CHECK: [[ACCESS:%.*]] = begin_access [read] [unknown] [[PROJECT]]
-// CHECK: [[CLASS:%.*]] = load_borrow [[ACCESS]]
+// CHECK: [[CLASS:%.*]] = load_borrow [unchecked] [[ACCESS]]
 // CHECK: ([[CORO_RESULT_ORIG:%.*]], [[CORO_TOKEN:%.*]]) = begin_apply {{%.*}}([[CLASS]])
 // CHECK: [[CORO_RESULT_CP:%.*]] = copy_value [[CORO_RESULT_ORIG]]
 // CHECK: [[CORO_RESULT_MK:%.*]] = mark_unresolved_non_copyable_value [no_consume_or_assign] [[CORO_RESULT_CP]]
@@ -2348,7 +2348,7 @@ public struct LoadableSubscriptGetModifyTesterNonCopyableStructParent : ~Copyabl
 // The second get call.
 // CHECK: [[ACCESS:%.*]] = begin_access [read] [unknown] [[PROJECT]]
 // CHECK: [[MARK:%.*]] = mark_unresolved_non_copyable_value [no_consume_or_assign] [[ACCESS]]
-// CHECK: [[LOAD_BORROW:%.*]] = load_borrow [[MARK]]
+// CHECK: [[LOAD_BORROW:%.*]] = load_borrow [unchecked] [[MARK]]
 // CHECK: [[VALUE:%.*]] = apply {{%.*}}([[LOAD_BORROW]])
 // CHECK: [[BORROWED_VALUE:%.*]] = begin_borrow [[VALUE]]
 // CHECK: [[TEMP:%.*]] = alloc_stack $AddressOnlyProtocol
@@ -2502,7 +2502,7 @@ public class LoadableSubscriptGetModifyTesterClassParent {
 // Third read.
 //
 // CHECK: [[ACCESS:%.*]] = begin_access [read] [unknown] [[PROJECT]]
-// CHECK: [[CLASS:%.*]] = load_borrow [[ACCESS]]
+// CHECK: [[CLASS:%.*]] = load_borrow [unchecked] [[ACCESS]]
 // CHECK: ([[CORO_RESULT_ORIG:%.*]], [[CORO_TOKEN:%.*]]) = begin_apply {{%.*}}([[CLASS]])
 // CHECK: [[CORO_RESULT_CP:%.*]] = copy_value [[CORO_RESULT_ORIG]]
 // CHECK: [[CORO_RESULT_MK:%.*]] = mark_unresolved_non_copyable_value [no_consume_or_assign] [[CORO_RESULT_CP]]

test/SILOptimizer/moveonly_consume_during_borrow_1.swift

@@ -0,0 +1,15 @@
+// RUN: %target-swift-frontend -emit-sil -verify %s
+
+func foo(x: consuming Foo) { // expected-error{{'x' used after consume}}
+ x.bar.foo(x) // expected-error{{overlapping accesses to 'x'}} expected-note 3 {{}}
+}
+
+struct Foo: ~Copyable {
+ var bar: Bar {
+ _read { fatalError() }
+ }
+}
+
+struct Bar: ~Copyable {
+ func foo(_: consuming Foo) {}
+}