[ExprContextAnalysis] Look into base type of optional as well when collecting callees for unresolved member (#33292)

Author: theblixguy

lib/IDE/ExprContextAnalysis.cpp

@@ -669,11 +669,9 @@ static bool collectPossibleCalleesForUnresolvedMember(
     SmallVectorImpl<FunctionTypeAndDecl> &candidates) {
   auto currModule = DC.getParentModule();
 
-  // Get the context of the expression itself.
-  ExprContextInfo contextInfo(&DC, unresolvedMemberExpr);
-  for (auto expectedTy : contextInfo.getPossibleTypes()) {
+  auto collectMembers = [&](Type expectedTy) {
     if (!expectedTy->mayHaveMembers())
-      continue;
+      return;
     SmallVector<FunctionTypeAndDecl, 2> members;
     collectPossibleCalleesByQualifiedLookup(DC, MetatypeType::get(expectedTy),
                                             unresolvedMemberExpr->getName(),
@@ -683,6 +681,16 @@ static bool collectPossibleCalleesForUnresolvedMember(
                                               member.Decl))
         candidates.push_back(member);
     }
+  };
+
+  // Get the context of the expression itself.
+  ExprContextInfo contextInfo(&DC, unresolvedMemberExpr);
+  for (auto expectedTy : contextInfo.getPossibleTypes()) {
+    collectMembers(expectedTy);
+    // If this is an optional type, let's also check its base type.
+    if (auto baseTy = expectedTy->getOptionalObjectType()) {
+      collectMembers(baseTy->lookThroughAllOptionalTypes());
+    }
   }
   return !candidates.empty();
 }

test/IDE/complete_call_arg.swift

@@ -80,6 +80,7 @@
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=STATIC_METHOD_SKIPPED | %FileCheck %s -check-prefix=STATIC_METHOD_SKIPPED
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=IMPLICIT_MEMBER_AFTERPAREN_1 | %FileCheck %s -check-prefix=IMPLICIT_MEMBER_AFTERPAREN_1
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=IMPLICIT_MEMBER_AFTERPAREN_2 | %FileCheck %s -check-prefix=IMPLICIT_MEMBER_AFTERPAREN_2
+// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=IMPLICIT_MEMBER_AFTERPAREN_3 | %FileCheck %s -check-prefix=IMPLICIT_MEMBER_AFTERPAREN_3
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=IMPLICIT_MEMBER_SECOND | %FileCheck %s -check-prefix=IMPLICIT_MEMBER_SECOND
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=IMPLICIT_MEMBER_SKIPPED | %FileCheck %s -check-prefix=IMPLICIT_MEMBER_SKIPPED
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=IMPLICIT_MEMBER_ARRAY_1_AFTERPAREN_1 | %FileCheck %s -check-prefix=IMPLICIT_MEMBER_AFTERPAREN_1
@@ -707,6 +708,11 @@ func testImplicitMember() {
 // IMPLICIT_MEMBER_AFTERPAREN_2-DAG: Literal[Integer]/None/TypeRelation[Identical]: 0[#Int#];
 // IMPLICIT_MEMBER_AFTERPAREN_2: End completions
 
+  let _: TestStaticMemberCall? = .create1(#^IMPLICIT_MEMBER_AFTERPAREN_3^#)
+// IMPLICIT_MEMBER_AFTERPAREN_3: Begin completions, 1 items
+// IMPLICIT_MEMBER_AFTERPAREN_3: Decl[StaticMethod]/CurrNominal:     ['(']{#arg1: Int#}[')'][#TestStaticMemberCall#]; name=arg1: Int
+// IMPLICIT_MEMBER_AFTERPAREN_3: End completions
+
   let _: TestStaticMemberCall = .create2(1, #^IMPLICIT_MEMBER_SECOND^#)
 // IMPLICIT_MEMBER_SECOND: Begin completions, 3 items
 // IMPLICIT_MEMBER_SECOND: Pattern/ExprSpecific: {#arg2: Int#}[#Int#];