[Serialization] Recover from failures under AnyObjectLookup

rdar://89494507

Author: xymus

lib/Serialization/ModuleFile.cpp

@@ -774,7 +774,15 @@ void ModuleFile::lookupClassMember(ImportPath::Access accessPath,
     // one.
     if (name.isSimpleName()) {
       for (auto item : *iter) {
-        auto vd = cast<ValueDecl>(getDecl(item.second));
+        auto declOrError = getDeclChecked(item.second);
+        if (!declOrError) {
+          if (!getContext().LangOpts.EnableDeserializationRecovery)
+            fatal(declOrError.takeError());
+          consumeError(declOrError.takeError());
+          continue;
+        }
+
+        auto vd = cast<ValueDecl>(declOrError.get());
         auto dc = vd->getDeclContext();
         while (!dc->getParent()->isModuleScopeContext())
           dc = dc->getParent();
@@ -784,7 +792,15 @@ void ModuleFile::lookupClassMember(ImportPath::Access accessPath,
       }
     } else {
       for (auto item : *iter) {
-        auto vd = cast<ValueDecl>(getDecl(item.second));
+        auto declOrError = getDeclChecked(item.second);
+        if (!declOrError) {
+          if (!getContext().LangOpts.EnableDeserializationRecovery)
+            fatal(declOrError.takeError());
+          consumeError(declOrError.takeError());
+          continue;
+        }
+
+        auto vd = cast<ValueDecl>(declOrError.get());
         if (!vd->getName().matchesRef(name))
           continue;
 
@@ -800,7 +816,15 @@ void ModuleFile::lookupClassMember(ImportPath::Access accessPath,
   }
 
   for (auto item : *iter) {
-    auto vd = cast<ValueDecl>(getDecl(item.second));
+    auto declOrError = getDeclChecked(item.second);
+    if (!declOrError) {
+      if (!getContext().LangOpts.EnableDeserializationRecovery)
+        fatal(declOrError.takeError());
+      consumeError(declOrError.takeError());
+      continue;
+    }
+
+    auto vd = cast<ValueDecl>(declOrError.get());
     results.push_back(vd);
   }
 }
@@ -818,6 +842,8 @@ void ModuleFile::lookupClassMembers(ImportPath::Access accessPath,
       for (auto item : list) {
         auto decl = getDeclChecked(item.second);
         if (!decl) {
+          if (!getContext().LangOpts.EnableDeserializationRecovery)
+            fatal(decl.takeError());
           llvm::consumeError(decl.takeError());
           continue;
         }
@@ -839,6 +865,8 @@ void ModuleFile::lookupClassMembers(ImportPath::Access accessPath,
     for (auto item : list) {
         auto decl = getDeclChecked(item.second);
         if (!decl) {
+          if (!getContext().LangOpts.EnableDeserializationRecovery)
+            fatal(decl.takeError());
           llvm::consumeError(decl.takeError());
           continue;
         }

test/Serialization/Recovery/Inputs/custom-modules/AnyObjectLookup.h

@@ -0,0 +1,3 @@
+#import <Foundation.h>
+
+@interface ImplOnlyBase: NSObject @end

test/Serialization/Recovery/Inputs/custom-modules/module.modulemap

@@ -14,3 +14,4 @@ module Typedefs { header "Typedefs.h" }
 module TypeRemovalObjC { header "TypeRemovalObjC.h" }
 module Types { header "Types.h" }
 module Conformance { header "Conformance.h" }
+module AnyObjectLookup { header "AnyObjectLookup.h" }

test/Serialization/Recovery/anyobject-lookup.swift

@@ -0,0 +1,29 @@
+/// Recover from searching though all possible methods on AnyObject.
+/// rdar://89494507
+
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -emit-module -DLIB_B %s -module-name B -emit-module-path %t/B.swiftmodule -I %t -I %S/Inputs/custom-modules -enable-library-evolution -swift-version 5
+// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -typecheck -DLIB_C %s -I %t -verify
+// Add this flag to the previous line to get back the original crash: -disable-deserialization-recovery
+
+// REQUIRES: objc_interop
+
+#if LIB_B
+
+import Foundation
+@_implementationOnly import AnyObjectLookup
+
+@objc internal class InternalClass: ImplOnlyBase {
+  @objc func invisibleMethod() {
+  }
+}
+
+#elseif LIB_C
+
+import B
+
+func use(_ obj: AnyObject) {
+  obj.invisibleMethod() // expected-error {{value of type 'AnyObject' has no member 'invisibleMethod'}}
+}
+
+#endif