Merge pull request swiftlang#16742 from apple/revert-16677-fix-static-stripped-error-bridging

Revert "[Runtime] Look up Error bridging symbols indirectly through special symbols that won't be stripped in static builds."

Author: benlangmuir

stdlib/public/SDK/Foundation/CMakeLists.txt

@@ -26,7 +26,6 @@ add_swift_library(swiftFoundation ${SWIFT_SDK_OVERLAY_LIBRARY_BUILD_TYPES} IS_SD
   NSCoder.swift
   NSDate.swift
   NSDictionary.swift
-  NSError.c
   NSError.swift
   NSExpression.swift
   NSFastEnumeration.swift

stdlib/public/SDK/Foundation/NSError.c

@@ -220,21 +220,6 @@ static Class getSwiftNativeNSErrorClass() {
   object_dispose((id)error);
 }
 
-/// Look up a symbol that points to something else. Treats the symbol as
-/// a void** and dereferences it if it's non-NULL. Returns NULL if the
-/// symbol can't be found or if the value is NULL.
-static void *dynamicLookupSymbol(const char *name) {
-  void **ptr = reinterpret_cast<void **>(dlsym(RTLD_DEFAULT, name));
-  if (!ptr) return nullptr;
-  return *ptr;
-}
-
-/// Look up an indirect pointer to a mangled Swift symbol, automatically
-/// prepending the ErrorObjectLookup_ prefix. Used to find the various
-/// Foundation overlay symbols for Error bridging.
-#define DYNAMIC_LOOKUP_SYMBOL(symbol) \
-  dynamicLookupSymbol("ErrorObjectLookup_" MANGLE_AS_STRING(MANGLE_SYM(symbol)))
-
 static const WitnessTable *getNSErrorConformanceToError() {
   // CFError and NSError are toll-free-bridged, so we can use either type's
   // witness table interchangeably. CFError's is potentially slightly more
@@ -243,7 +228,8 @@ static Class getSwiftNativeNSErrorClass() {
   // to assume that that's been linked in if a user is using NSError in their
   // Swift source.
 
-  auto TheWitnessTable = SWIFT_LAZY_CONSTANT(DYNAMIC_LOOKUP_SYMBOL(So10CFErrorRefas5Error10FoundationWa));
+  auto TheWitnessTable = SWIFT_LAZY_CONSTANT(dlsym(RTLD_DEFAULT,
+      MANGLE_AS_STRING(MANGLE_SYM(So10CFErrorRefas5Error10FoundationWa))));
   assert(TheWitnessTable &&
          "Foundation overlay not loaded, or 'CFError : Error' conformance "
          "not available");
@@ -252,7 +238,8 @@ static Class getSwiftNativeNSErrorClass() {
 }
 
 static const HashableWitnessTable *getNSErrorConformanceToHashable() {
-  auto TheWitnessTable = SWIFT_LAZY_CONSTANT(DYNAMIC_LOOKUP_SYMBOL(So8NSObjectCs8Hashable10ObjectiveCWa));
+  auto TheWitnessTable = SWIFT_LAZY_CONSTANT(dlsym(RTLD_DEFAULT,
+           MANGLE_AS_STRING(MANGLE_SYM(So8NSObjectCs8Hashable10ObjectiveCWa))));
   assert(TheWitnessTable &&
          "ObjectiveC overlay not loaded, or 'NSObject : Hashable' conformance "
          "not available");
@@ -392,7 +379,8 @@ typedef SWIFT_CC(swift)
   // public func Foundation._getErrorDefaultUserInfo<T: Error>(_ error: T)
   //   -> AnyObject?
   auto foundationGetDefaultUserInfo = SWIFT_LAZY_CONSTANT(
-    reinterpret_cast<GetDefaultFn*> (DYNAMIC_LOOKUP_SYMBOL(10Foundation24_getErrorDefaultUserInfoyyXlSgxs0C0RzlF)));
+    reinterpret_cast<GetDefaultFn*> (dlsym(RTLD_DEFAULT,
+    MANGLE_AS_STRING(MANGLE_SYM(10Foundation24_getErrorDefaultUserInfoyyXlSgxs0C0RzlF)))));
   if (!foundationGetDefaultUserInfo) {
     SWIFT_CC_PLUSONE_GUARD(T->vw_destroy(error));
     return nullptr;
@@ -521,10 +509,12 @@ typedef SWIFT_CC(swift)
     bool BridgeFn(NSError *, OpaqueValue*, const Metadata *,
                   const WitnessTable *);
   auto bridgeNSErrorToError = SWIFT_LAZY_CONSTANT(
-    reinterpret_cast<BridgeFn*>(DYNAMIC_LOOKUP_SYMBOL(10Foundation21_bridgeNSErrorToError_3outSbSo0C0C_SpyxGtAA021_ObjectiveCBridgeableE0RzlF)));
+    reinterpret_cast<BridgeFn*>(dlsym(RTLD_DEFAULT,
+    MANGLE_AS_STRING(MANGLE_SYM(10Foundation21_bridgeNSErrorToError_3outSbSo0C0C_SpyxGtAA021_ObjectiveCBridgeableE0RzlF)))));
   // protocol _ObjectiveCBridgeableError
   auto TheObjectiveCBridgeableError = SWIFT_LAZY_CONSTANT(
-    reinterpret_cast<const ProtocolDescriptor *>(DYNAMIC_LOOKUP_SYMBOL(10Foundation26_ObjectiveCBridgeableErrorMp)));
+    reinterpret_cast<const ProtocolDescriptor *>(dlsym(RTLD_DEFAULT,
+    MANGLE_AS_STRING(MANGLE_SYM(10Foundation26_ObjectiveCBridgeableErrorMp)))));
 
   // If the Foundation overlay isn't loaded, then arbitrary NSErrors can't be
   // bridged.

stdlib/public/runtime/ErrorObject.mm

@@ -14,10 +14,6 @@ class Bar: Foo {
   override func foo(_ x: Int32) throws {
     try super.foo(5)
   }
-  
-  override func foothrows(_ x: Int32) throws {
-    try super.foothrows(5)
-  }
 }
 
 var ErrorBridgingStaticTests = TestSuite("ErrorBridging with static libs")
@@ -28,14 +24,4 @@ ErrorBridgingStaticTests.test("round-trip Swift override of ObjC method") {
   } catch { }
 }
 
-ErrorBridgingStaticTests.test("round-trip Swift override of throwing ObjC method") {
-  do {
-    try (Bar() as Foo).foothrows(5)
-  } catch {
-    print(error)
-    expectEqual(error._domain, "abcd")
-    expectEqual(error._code, 1234)
-  }
-}
-
 runAllTests()

test/stdlib/ErrorBridgedStatic.swift

@@ -3,6 +3,5 @@
 @interface Foo: NSObject
 
 - (BOOL)foo:(int)x error:(NSError**)error;
-- (BOOL)foothrows:(int)x error:(NSError**)error;
 
 @end

test/stdlib/Inputs/ErrorBridgedStaticImpl.h

@@ -7,10 +7,5 @@ - (BOOL)foo:(int)x error:(NSError**)error {
   return NO;
 }
 
-- (BOOL)foothrows:(int)x error:(NSError**)error {
-  *error = [NSError errorWithDomain: @"abcd" code: 1234 userInfo: nil];
-  return NO;
-}
-
 @end