Merge pull request #4693 from jrose-apple/swift-3-swift_error-zero_result

[SILGen] Restore old logic for checking (non-)zero error results.

Author: tkremenek

lib/SILGen/SILGenForeignError.cpp

@@ -290,20 +290,16 @@ void SILGenFunction::emitForeignErrorBlock(SILLocation loc,
 static SILValue emitUnwrapIntegerResult(SILGenFunction &gen,
                                         SILLocation loc,
                                         SILValue value) {
-  CanType boolType = gen.SGM.Types.getBoolType();
-
-  value = gen.emitBridgedToNativeValue(
-      loc, ManagedValue::forUnmanaged(value),
-      SILFunctionTypeRepresentation::CFunctionPointer,
-      boolType).forward(gen);
-
-  auto structDecl = value->getType().getStructOrBoundGenericStruct();
-  assert(structDecl && "value for error result wasn't of struct type!");
-  assert(std::next(structDecl->getStoredProperties().begin())
-           == structDecl->getStoredProperties().end());
-  auto property = *structDecl->getStoredProperties().begin();
-  value = gen.B.createStructExtract(loc, value, property);
-  assert(value->getType().is<BuiltinIntegerType>());
+  // This is a loop because we want to handle types that wrap integer types,
+  // like ObjCBool (which may be Bool or Int8).
+  while (!value->getType().is<BuiltinIntegerType>()) {
+    auto structDecl = value->getType().getStructOrBoundGenericStruct();
+    assert(structDecl && "value for error result wasn't of struct type!");
+    assert(std::next(structDecl->getStoredProperties().begin())
+             == structDecl->getStoredProperties().end());
+    auto property = *structDecl->getStoredProperties().begin();
+    value = gen.B.createStructExtract(loc, value, property);
+  }
 
   return value;
 }

test/Inputs/clang-importer-sdk/swift-modules/Foundation.swift

@@ -103,6 +103,28 @@ extension Int : _ObjectiveCBridgeable {
   }
 }
 
+extension Bool: _ObjectiveCBridgeable {
+  public func _bridgeToObjectiveC() -> NSNumber {
+    return NSNumber()
+  }
+  public static func _forceBridgeFromObjectiveC(
+    _ x: NSNumber, 
+    result: inout Bool?
+  ) {
+  }
+  public static func _conditionallyBridgeFromObjectiveC(
+    _ x: NSNumber,
+    result: inout Bool?
+  ) -> Bool {
+    return true
+  }
+  public static func _unconditionallyBridgeFromObjectiveC(
+    _ x: NSNumber?
+  ) -> Bool {
+    return false
+  }
+}
+
 extension Array : _ObjectiveCBridgeable {
   public func _bridgeToObjectiveC() -> NSArray {
     return NSArray()

test/Inputs/clang-importer-sdk/usr/include/errors.h

@@ -45,6 +45,7 @@
 + (float) bounce: (NSError**) err __attribute__((swift_error(nonnull_error)));
 + (void) flounce: (NSError**) err __attribute__((swift_error(nonnull_error)));
 + (int) ounce: (NSError**) err __attribute__((swift_error(zero_result)));
++ (NSInteger) ounceWord: (NSError**) err __attribute__((swift_error(zero_result)));
 + (int) once: (NSError**) err __attribute__((swift_error(nonzero_result)));
 + (BOOL) sconce: (NSError**) err __attribute__((swift_error(zero_result)));
 + (BOOL) scotch: (NSError**) err __attribute__((swift_error(nonzero_result)));

test/SILGen/foreign_errors.swift

@@ -1,4 +1,6 @@
-// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -emit-silgen -parse-as-library %s | %FileCheck %s
+// RUN: rm -rf %t && mkdir -p %t
+// RUN: %build-clang-importer-objc-overlays
+// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk-nosource -I %t) -emit-silgen -parse-as-library %s | %FileCheck %s
 
 // REQUIRES: objc_interop
 
@@ -31,10 +33,12 @@ func test0() throws {
   // CHECK: assign [[T1]] to [[ERR_TEMP0]]
 
   //   Pull out the boolean value and compare it to zero.
-  // CHECK: [[FN:%.*]] = function_ref @_TF10ObjectiveC22_convertObjCBoolToBoolFVS_8ObjCBoolSb
-  // CHECK: [[BOOL:%.*]] = apply [[FN]]([[RESULT]])
-  // CHECK: [[BIT:%.*]] = struct_extract [[BOOL]]
-  // CHECK: cond_br [[BIT]], [[NORMAL_BB:bb[0-9]+]], [[ERROR_BB:bb[0-9]+]]
+  // CHECK: [[BOOL_OR_INT:%.*]] = struct_extract [[RESULT]]
+  // CHECK: [[RAW_VALUE:%.*]] = struct_extract [[BOOL_OR_INT]]
+  //   On some platforms RAW_VALUE will be compared against 0; on others it's
+  //   already an i1 (bool) and those instructions will be skipped. Just do a
+  //   looser check.
+  // CHECK: cond_br {{%.+}}, [[NORMAL_BB:bb[0-9]+]], [[ERROR_BB:bb[0-9]+]]
   try ErrorProne.fail()
 
   //   Normal path: fall out and return.
@@ -229,3 +233,39 @@ func testPreservedResult() throws -> CInt {
 // CHECK-NOT: release
 // CHECK:   return [[RESULT]]
 // CHECK: [[ERROR_BB]]
+
+func testPreservedResultBridged() throws -> Int {
+  return try ErrorProne.ounceWord()
+}
+
+// CHECK-LABEL: sil hidden @_TF14foreign_errors26testPreservedResultBridgedFzT_Si
+// CHECK:   [[T0:%.*]] = metatype $@thick ErrorProne.Type
+// CHECK:   [[T1:%.*]] = class_method [volatile] [[T0]] : $@thick ErrorProne.Type, #ErrorProne.ounceWord!1.foreign : (ErrorProne.Type) -> () throws -> Int , $@convention(objc_method) (ImplicitlyUnwrappedOptional<AutoreleasingUnsafeMutablePointer<Optional<NSError>>>, @objc_metatype ErrorProne.Type) -> Int
+// CHECK:   [[OPTERR:%.*]] = alloc_stack $Optional<NSError>
+// CHECK:   [[RESULT:%.*]] = apply [[T1]](
+// CHECK:   [[T0:%.*]] = struct_extract [[RESULT]]
+// CHECK:   [[T1:%.*]] = integer_literal $[[PRIM:Builtin.Int[0-9]+]], 0
+// CHECK:   [[T2:%.*]] = builtin "cmp_ne_Int{{.*}}"([[T0]] : $[[PRIM]], [[T1]] : $[[PRIM]])
+// CHECK:   cond_br [[T2]], [[NORMAL_BB:bb[0-9]+]], [[ERROR_BB:bb[0-9]+]]
+// CHECK: [[NORMAL_BB]]:
+// CHECK-NOT: release
+// CHECK:   return [[RESULT]]
+// CHECK: [[ERROR_BB]]
+
+func testPreservedResultInverted() throws {
+  try ErrorProne.once()
+}
+
+// CHECK-LABEL: sil hidden @_TF14foreign_errors27testPreservedResultInvertedFzT_T_
+// CHECK:   [[T0:%.*]] = metatype $@thick ErrorProne.Type
+// CHECK:   [[T1:%.*]] = class_method [volatile] [[T0]] : $@thick ErrorProne.Type, #ErrorProne.once!1.foreign : (ErrorProne.Type) -> () throws -> () , $@convention(objc_method) (ImplicitlyUnwrappedOptional<AutoreleasingUnsafeMutablePointer<Optional<NSError>>>, @objc_metatype ErrorProne.Type) -> Int32
+// CHECK:   [[OPTERR:%.*]] = alloc_stack $Optional<NSError>
+// CHECK:   [[RESULT:%.*]] = apply [[T1]](
+// CHECK:   [[T0:%.*]] = struct_extract [[RESULT]]
+// CHECK:   [[T1:%.*]] = integer_literal $[[PRIM:Builtin.Int[0-9]+]], 0
+// CHECK:   [[T2:%.*]] = builtin "cmp_ne_Int32"([[T0]] : $[[PRIM]], [[T1]] : $[[PRIM]])
+// CHECK:   cond_br [[T2]], [[ERROR_BB:bb[0-9]+]], [[NORMAL_BB:bb[0-9]+]]
+// CHECK: [[NORMAL_BB]]:
+// CHECK-NOT: release
+// CHECK:   return {{%.+}} : $()
+// CHECK: [[ERROR_BB]]