[SIL] Preserve pointer_escape flag during cloning.

Author: nate-chandler

docs/SIL.rst

@@ -4517,6 +4517,9 @@ The optional ``lexical`` attribute specifies that the operand corresponds to a
 local variable in the Swift source, so special care must be taken when moving
 the end_borrow.
 
+The optional ``pointer_escape`` attribute specifies that a pointer to the
+operand escapes within the borrow scope introduced by this begin_borrow.
+
 This instruction is only valid in functions in Ownership SSA form.
 
 end_borrow
@@ -6375,6 +6378,9 @@ a type `T` into the move only value space.
 The ``lexical`` attribute specifies that the value corresponds to a local
 variable in the Swift source.
 
+The optional ``pointer_escape`` attribute specifies that a pointer to the
+operand escapes within the scope introduced by this move_value.
+
 
 drop_deinit
 ```````````

include/swift/SIL/SILCloner.h

@@ -1218,9 +1218,9 @@ void SILCloner<ImplClass>::visitBeginBorrowInst(BeginBorrowInst *Inst) {
   }
 
   recordClonedInstruction(
-      Inst, getBuilder().createBeginBorrow(getOpLocation(Inst->getLoc()),
-                                           getOpValue(Inst->getOperand()),
-                                           Inst->isLexical()));
+      Inst, getBuilder().createBeginBorrow(
+                getOpLocation(Inst->getLoc()), getOpValue(Inst->getOperand()),
+                Inst->isLexical(), Inst->hasPointerEscape()));
 }
 
 template <typename ImplClass>
@@ -1930,9 +1930,9 @@ void SILCloner<ImplClass>::visitMoveValueInst(MoveValueInst *Inst) {
   if (!getBuilder().hasOwnership()) {
     return recordFoldedValue(Inst, getOpValue(Inst->getOperand()));
   }
-  auto *MVI = getBuilder().createMoveValue(getOpLocation(Inst->getLoc()),
-                                           getOpValue(Inst->getOperand()),
-                                           Inst->isLexical());
+  auto *MVI = getBuilder().createMoveValue(
+      getOpLocation(Inst->getLoc()), getOpValue(Inst->getOperand()),
+      Inst->isLexical(), Inst->hasPointerEscape());
   MVI->setAllowsDiagnostics(Inst->getAllowDiagnostics());
   recordClonedInstruction(Inst, MVI);
 }

test/SIL/cloning.sil

@@ -28,20 +28,23 @@ bb0:
   return %2 : $()
 }
 
-sil [ossa] [always_inline] @callee_begin_borrow_lexical : $@convention(thin) () -> () {
+sil [ossa] [always_inline] @callee_begin_borrow : $@convention(thin) () -> () {
   %instance = alloc_ref $X
   %guaranteed_c = begin_borrow [lexical] %instance : $X
   end_borrow %guaranteed_c : $X
+  %guaranteed_c2 = begin_borrow [pointer_escape] %instance : $X
+  end_borrow %guaranteed_c2 : $X
   destroy_value %instance : $X
   %res = tuple ()
   return %res : $()
 }
 
 // CHECK-LABEL: sil [ossa] @caller_begin_borrow_lexical
 // CHECK: begin_borrow [lexical]
+// CHECK: begin_borrow [pointer_escape]
 // CHECK-LABEL: } // end sil function 'caller_begin_borrow_lexical'
 sil [ossa] @caller_begin_borrow_lexical : $@convention(thin) () -> () {
-  %callee_begin_borrow_lexical = function_ref @callee_begin_borrow_lexical : $@convention(thin) () -> ()
+  %callee_begin_borrow_lexical = function_ref @callee_begin_borrow : $@convention(thin) () -> ()
   %res = apply %callee_begin_borrow_lexical() : $@convention(thin) () -> ()
   return %res : $()
 }
@@ -77,7 +80,8 @@ entry(%0 : @owned $Builtin.NativeObject):
   %2 = move_value [allows_diagnostics] %1 : $Builtin.NativeObject
   %3 = move_value [lexical] %2 : $Builtin.NativeObject
   %4 = move_value [allows_diagnostics] [lexical] %3 : $Builtin.NativeObject
-  return %4 : $Builtin.NativeObject
+  %5 = move_value [pointer_escape] %4 : $Builtin.NativeObject
+  return %5 : $Builtin.NativeObject
 }
 
 // CHECK-LABEL: sil [ossa] @caller_move_value {{.*}} {
@@ -86,7 +90,8 @@ entry(%0 : @owned $Builtin.NativeObject):
 // CHECK:       [[REGISTER_2:%[^,]+]] = move_value [allows_diagnostics] [[REGISTER_1]]
 // CHECK:       [[REGISTER_3:%[^,]+]] = move_value [lexical] [[REGISTER_2]]
 // CHECK:       [[REGISTER_4:%[^,]+]] = move_value [allows_diagnostics] [lexical] [[REGISTER_3]]
-// CHECK:       return [[REGISTER_4]]
+// CHECK:       [[REGISTER_5:%[^,]+]] = move_value [pointer_escape] [[REGISTER_4]]
+// CHECK:       return [[REGISTER_5]]
 // CHECK-LABEL: } // end sil function 'caller_move_value'
 sil [ossa] @caller_move_value : $@convention(thin) (@owned Builtin.NativeObject) -> @owned Builtin.NativeObject {
 entry(%0 : @owned $Builtin.NativeObject):