[CodeCompletion] Insert code completion token into build block call to retrieve contextual type

rdar://94224692

Author: ahoppen

lib/IDE/CodeCompletionResultType.cpp

@@ -184,7 +184,7 @@ const USRBasedType *USRBasedType::fromType(Type Ty, USRBasedTypeArena &Arena) {
   Ty = Ty->getCanonicalType();
 
   // For opaque types like 'some View', consider them equivalent to 'View'.
-  if (auto OpaqueType = Ty->getAs<OpaqueTypeArchetypeType>()) {
+  if (auto OpaqueType = Ty->getAs<ArchetypeType>()) {
     if (auto Existential = OpaqueType->getExistentialType()) {
       Ty = Existential;
     }

lib/Sema/BuilderTransform.cpp

@@ -1058,11 +1058,20 @@ class ResultBuilderTransform
                                {Identifier()});
     }
 
-    auto *capture = captureExpr(expr, newBody);
-    // A reference to the synthesized variable is passed as an argument
-    // to buildBlock.
-    buildBlockArguments.push_back(
-        builder.buildVarRef(capture, element.getStartLoc()));
+    if (isa<CodeCompletionExpr>(expr)) {
+      // Insert the CodeCompletionExpr directly into the buildBlock call. That
+      // way, we can extract the contextual type of the code completion token
+      // to rank code completion items that match the type expected by
+      // buildBlock higher.
+      buildBlockArguments.push_back(expr);
+    } else {
+      auto *capture = captureExpr(expr, newBody);
+      // A reference to the synthesized variable is passed as an argument
+      // to buildBlock.
+      buildBlockArguments.push_back(
+          builder.buildVarRef(capture, element.getStartLoc()));
+    }
+
     return None;
   }
 

lib/Sema/TypeCheckConstraints.cpp

@@ -998,11 +998,6 @@ static Type replaceArchetypesWithTypeVariables(ConstraintSystem &cs,
         return found->second;
 
       if (auto archetypeType = dyn_cast<ArchetypeType>(origType)) {
-        // We leave opaque types and their nested associated types alone here.
-        // They're globally available.
-        if (isa<OpaqueTypeArchetypeType>(archetypeType))
-          return origType;
-
         auto root = archetypeType->getRoot();
         // For other nested types, fail here so the default logic in subst()
         // for nested types applies.
@@ -1033,7 +1028,8 @@ static Type replaceArchetypesWithTypeVariables(ConstraintSystem &cs,
       types[origType] = replacement;
       return replacement;
     },
-    MakeAbstractConformanceForGenericType());
+    MakeAbstractConformanceForGenericType(),
+    SubstFlags::SubstituteOpaqueArchetypes);
 }
 
 bool TypeChecker::typesSatisfyConstraint(Type type1, Type type2,

test/IDE/complete_from_swift_module.swift

@@ -184,7 +184,7 @@ func testAmbiguousResultBuilder() {
     // Results should only contain globalVar once
     // AMBIGOUS_RESULT_BUILER: Begin completions
     // AMBIGOUS_RESULT_BUILER-NOT: globalVar
-    // AMBIGOUS_RESULT_BUILER-DAG: Decl[GlobalVar]/OtherModule[foo_swift_module]: globalVar[#Int#]; name=globalVar
+    // AMBIGOUS_RESULT_BUILER-DAG: Decl[GlobalVar]/OtherModule[foo_swift_module]/TypeRelation[Convertible]: globalVar[#Int#]; name=globalVar
     // AMBIGOUS_RESULT_BUILER-NOT: globalVar
     // AMBIGOUS_RESULT_BUILER: End completions
   }

test/IDE/complete_issue-57061.swift

@@ -39,5 +39,5 @@ public struct ForEach2<Data, ID, Content>: View2 where Data : RandomAccessCollec
 
 // CHECK: Begin completions, 2 items
 // CHECK-NEXT: Keyword[self]/CurrNominal:          self[#Text2#];
-// CHECK-NEXT: Decl[InstanceMethod]/Super:         font()[#View2#];
+// CHECK-NEXT: Decl[InstanceMethod]/Super/TypeRelation[Convertible]:         font()[#View2#];
 // CHECK-NEXT: End completions

tools/swift-ide-test/swift-ide-test.cpp

@@ -4395,6 +4395,8 @@ int main(int argc, char *argv[]) {
     options::ImportObjCHeader;
   InitInvok.getClangImporterOptions().BridgingHeader =
     options::ImportObjCHeader;
+  InitInvok.getLangOptions().Features.insert(
+      Feature::ResultBuilderASTTransform);
   InitInvok.getLangOptions().EnableAccessControl =
     !options::DisableAccessControl;
   InitInvok.getLangOptions().EnableSwift3ObjCInference =