Merge pull request #15393 from aschwaighofer/silgen_fix_withoutActuallyEscaping_of_blocks

Author: swift-ci

lib/SILGen/SILGenExpr.cpp

@@ -5480,6 +5480,28 @@ RValue RValueEmitter::visitMakeTemporarilyEscapableExpr(
     visit(E->getNonescapingClosureValue()).getAsSingleValue(SGF, E);
 
   auto escapingFnTy = SGF.getLoweredType(E->getOpaqueValue()->getType());
+  auto silFnTy = escapingFnTy.castTo<SILFunctionType>();
+
+  // Handle @convention(block). No withoutActuallyEscaping verification yet.
+  if (silFnTy->getExtInfo().getRepresentation() !=
+      SILFunctionTypeRepresentation::Thick) {
+    RValue rvalue;
+    auto escapingClosure =
+        SGF.emitManagedRValueWithCleanup(SGF.B.createConvertFunction(
+            E, functionValue.ensurePlusOne(SGF, E).forward(SGF), escapingFnTy));
+    // Bind the opaque value to the escaping function.
+    SILGenFunction::OpaqueValueState opaqueValue{
+        escapingClosure,
+        /*consumable*/ true,
+        /*hasBeenConsumed*/ false,
+    };
+    SILGenFunction::OpaqueValueRAII pushOpaqueValue(SGF, E->getOpaqueValue(),
+                                                    opaqueValue);
+
+    // Emit the guarded expression.
+    rvalue = visit(E->getSubExpr(), C);
+    return rvalue;
+  }
 
   // Convert it to an escaping function value.
   auto escapingClosure =

test/SILGen/without_actually_escaping_block.swift

@@ -0,0 +1,26 @@
+// RUN: %target-swift-frontend -module-name without_actually_escaping -emit-silgen -enable-sil-ownership %s | %FileCheck %s
+
+// REQUIRES: objc_interop
+
+import Foundation
+
+typealias Callback = @convention(block) () -> Void
+
+// CHECK-LABEL: sil {{.*}} @$S25without_actually_escaping9testBlock5blockyyyXB_tF
+// CHECK: bb0([[ARG:%.*]] : @guaranteed $@convention(block) @noescape () -> ()):
+// CHECK:  [[C1:%.*]] = copy_block [[ARG]]
+// CHECK:  [[B1:%.*]] = begin_borrow [[C1]]
+// CHECK:  [[C2:%.*]] = copy_value [[B1]]
+// CHECK:  [[CVT:%.*]] = convert_function [[C2]] : $@convention(block) @noescape () -> () to $@convention(block) () -> ()
+// CHECK:  [[B2:%.*]] = begin_borrow [[CVT]]
+// CHECK:  [[FN:%.*]] = function_ref @$S25without_actually_escaping9testBlock5blockyyyXB_tFyyyXBXEfU_
+// CHECK:  apply [[FN]]([[B2]])
+// CHECK:  end_borrow [[B2]] from [[CVT]]
+// CHECK:  destroy_value [[CVT]]
+// CHECK:  end_borrow [[B1]] from [[C1]]
+// CHECK:  destroy_value [[C1]]
+// CHECK:  return
+
+func testBlock(block: Callback) {
+  withoutActuallyEscaping(block) { $0() }
+}