[Foundation][runtime] Remove swift_errorBridgingInfo

To implement swift_errorBridgingInfo, the Foundation overlay needs to import private runtime headers. Now that we cannot statically link the Foundation overlay, there is no point to keeping this workaround in the overlay any more.

This effectively reverts #16677.

rdar://problem/57809306

Author: lorentey

stdlib/public/Darwin/Foundation/CMakeLists.txt

@@ -32,7 +32,6 @@ add_swift_target_library(swiftFoundation ${SWIFT_SDK_OVERLAY_LIBRARY_BUILD_TYPES
   NSCoder.swift
   NSDate.swift
   NSDictionary.swift
-  NSError.mm
   NSError.swift
   NSExpression.swift
   NSFastEnumeration.swift

stdlib/public/Darwin/Foundation/NSError.h

@@ -37,7 +37,6 @@
 #include <objc/message.h>
 #include <objc/objc.h>
 #include <Foundation/Foundation.h>
-#include "../Darwin/Foundation/NSError.h"
 
 using namespace swift;
 using namespace swift::hashable_support;
@@ -260,19 +259,6 @@ static id getEmptyNSDictionary() {
   object_dispose((id)error);
 }
 
-/// Get the error bridging info from the Foundation overlay. If it can't
-/// be loaded, return all NULLs.
-static ErrorBridgingInfo getErrorBridgingInfo() {
-  auto *info = SWIFT_LAZY_CONSTANT(
-    reinterpret_cast<ErrorBridgingInfo *>(
-      dlsym(RTLD_DEFAULT, ERROR_BRIDGING_SYMBOL_NAME_STRING)));
-  if (!info) {
-    ErrorBridgingInfo nulls = {};
-    return nulls;
-  }
-  return *info;
-}
-
 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
@@ -281,7 +267,10 @@ static ErrorBridgingInfo getErrorBridgingInfo() {
   // safe to assume that that's been linked in if a user is using NSError in
   // their Swift source.
 
-  auto conformance = getErrorBridgingInfo().CFErrorErrorConformance;
+  auto *conformance = SWIFT_LAZY_CONSTANT(
+    reinterpret_cast<const ProtocolConformanceDescriptor *>(
+      dlsym(RTLD_DEFAULT,
+            MANGLE_AS_STRING(MANGLE_SYM(So10CFErrorRefas5Error10FoundationMc)))));
   assert(conformance &&
          "Foundation overlay not loaded, or 'CFError : Error' conformance "
          "not available");
@@ -291,7 +280,10 @@ static ErrorBridgingInfo getErrorBridgingInfo() {
 }
 
 static const HashableWitnessTable *getNSErrorConformanceToHashable() {
-  auto conformance = getErrorBridgingInfo().NSObjectHashableConformance;
+  auto *conformance = SWIFT_LAZY_CONSTANT(
+    reinterpret_cast<const ProtocolConformanceDescriptor *>(
+      dlsym(RTLD_DEFAULT,
+            MANGLE_AS_STRING(MANGLE_SYM(So8NSObjectCSH10ObjectiveCMc)))));
   assert(conformance &&
          "ObjectiveC overlay not loaded, or 'NSObject : Hashable' conformance "
          "not available");
@@ -427,7 +419,15 @@ id _swift_stdlib_getErrorDefaultUserInfo(OpaqueValue *error,
                                          const WitnessTable *Error) {
   // public func Foundation._getErrorDefaultUserInfo<T: Error>(_ error: T)
   //   -> AnyObject?
-  auto foundationGetDefaultUserInfo = getErrorBridgingInfo().GetErrorDefaultUserInfo;
+  typedef SWIFT_CC(swift) NSDictionary *(*GetErrorDefaultUserInfoFunction)(
+    const OpaqueValue *error,
+    const Metadata *T,
+    const WitnessTable *Error);
+  auto foundationGetDefaultUserInfo = SWIFT_LAZY_CONSTANT(
+    reinterpret_cast<GetErrorDefaultUserInfoFunction>(
+      dlsym(RTLD_DEFAULT,
+            MANGLE_AS_STRING(MANGLE_SYM(10Foundation24_getErrorDefaultUserInfoyyXlSgxs0C0RzlF)))));
+
   if (!foundationGetDefaultUserInfo) {
     return nullptr;
   }
@@ -533,9 +533,19 @@ ProtocolDescriptorRef theErrorProtocol(&PROTOCOL_DESCR_SYM(s5Error),
   // public func Foundation._bridgeNSErrorToError<
   //   T : _ObjectiveCBridgeableError
   // >(error: NSError, out: UnsafeMutablePointer<T>) -> Bool {
-  auto bridgeNSErrorToError = getErrorBridgingInfo().BridgeErrorToNSError;
+  typedef SWIFT_CC(swift) bool (*BridgeErrorToNSErrorFunction)(
+    NSError *, OpaqueValue*, const Metadata *,
+    const WitnessTable *);
+  auto bridgeNSErrorToError = SWIFT_LAZY_CONSTANT(
+    reinterpret_cast<BridgeErrorToNSErrorFunction>(
+      dlsym(RTLD_DEFAULT,
+            MANGLE_AS_STRING(MANGLE_SYM(10Foundation21_bridgeNSErrorToError_3outSbSo0C0C_SpyxGtAA021_ObjectiveCBridgeableE0RzlF)))));
+  
   // protocol _ObjectiveCBridgeableError
-  auto TheObjectiveCBridgeableError = getErrorBridgingInfo().ObjectiveCBridgeableError;
+  auto TheObjectiveCBridgeableError = SWIFT_LAZY_CONSTANT(
+    reinterpret_cast<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.