Fixes in SILGen for opaque value support in coroutines (#58696)

Author: meg-gupta

lib/SILGen/SILGenApply.cpp

@@ -3119,7 +3119,7 @@ class ArgEmitter {
     auto emissionKind = SGFAccessKind::BorrowedObjectRead;
     for (auto param : claimedParams) {
       assert(!param.isConsumed());
-      if (param.isIndirectInGuaranteed()) {
+      if (param.isIndirectInGuaranteed() && SGF.silConv.useLoweredAddresses()) {
         emissionKind = SGFAccessKind::BorrowedAddressRead;
         break;
       }
@@ -3497,8 +3497,10 @@ static void emitBorrowedLValueRecursive(SILGenFunction &SGF,
 
   // Load if necessary.
   assert(!param.isConsumed() && "emitting borrow into consumed parameter?");
-  if (!param.isIndirectInGuaranteed() && value.getType().isAddress()) {
-    value = SGF.B.createFormalAccessLoadBorrow(loc, value);
+  if (value.getType().isAddress()) {
+    if (!param.isIndirectInGuaranteed() || !SGF.silConv.useLoweredAddresses()) {
+      value = SGF.B.createFormalAccessLoadBorrow(loc, value);
+    }
   }
 
   assert(param.getInterfaceType() == value.getType().getASTType());

lib/SILGen/SILGenPoly.cpp

@@ -1746,8 +1746,12 @@ static ManagedValue manageYield(SILGenFunction &SGF, SILValue value,
     if (value.getOwnershipKind() == OwnershipKind::None)
       return ManagedValue::forUnmanaged(value);
     return ManagedValue::forBorrowedObjectRValue(value);
-  case ParameterConvention::Indirect_In_Guaranteed:
-    return ManagedValue::forBorrowedAddressRValue(value);
+  case ParameterConvention::Indirect_In_Guaranteed: {
+    bool isOpaque = SGF.getTypeLowering(value->getType()).isAddressOnly() &&
+                    !SGF.silConv.useLoweredAddresses();
+    return isOpaque ? ManagedValue::forBorrowedObjectRValue(value)
+                    : ManagedValue::forBorrowedAddressRValue(value);
+  }
   }
   llvm_unreachable("bad kind");
 }

test/SILGen/opaque_values_silgen.swift

@@ -435,3 +435,29 @@ func testCastClassArchetypeToClass<T : AnyObject>(_ o: T) -> C {
     break
   }
 }
+
+class TestGeneric<T> {
+  init() {}
+
+  var generic: T
+  @_borrowed
+  var borrowedGeneric: T
+}
+
+// CHECK-LABEL: sil hidden [transparent] [ossa] @$s20opaque_values_silgen11TestGenericC08borrowedE0xvr :
+// CHECK: bb0(%0 : @guaranteed $TestGeneric<T>):
+// CHECK:   [[REF:%.*]] = ref_element_addr %0 : $TestGeneric<T>, #TestGeneric.borrowedGeneric
+// CHECK:   [[ACCESS:%.*]] = begin_access [read] [dynamic] [[REF]] : $*T
+// CHECK:   [[LD:%.*]] = load_borrow [[ACCESS]] : $*T
+// CHECK:   yield [[LD]] : $T, resume bb1, unwind bb2
+// CHECK: bb1:
+// CHECK:   end_borrow [[LD]] : $T
+// CHECK:   end_access [[ACCESS]] : $*T
+// CHECK:   [[RES:%.*]] = tuple ()
+// CHECK:   return [[RES]] : $()
+// CHECK: bb2:
+// CHECK:   end_borrow [[LD]] : $T
+// CHECK:   end_access [[ACCESS]] : $*T
+// CHECK:   unwind
+// CHECK-LABEL: } // end sil function '$s20opaque_values_silgen11TestGenericC08borrowedE0xvr'
+