[CodeCompletion] Introduce 'Unknown' type relation

Now

* NotApplicable: The result is not relevant for type relation (e.g.
  keywords, and overloads)
* Unknown: the relation was not calculated (e.g. cached results), or the
  context type is unknown.
* Invalid: The result type is invalid for this context (i.e. 'Void' for
  non-'Void' context)
* Unrelated: The result type has no relation to the context type
* Convertible: The result type is convertible to the context type
* Identical: The result type is identical to the context type

Author: rintaro

include/swift/IDE/CodeCompletion.h

@@ -530,6 +530,9 @@ class CodeCompletionResult {
     /// The result does not have a type (e.g. keyword).
     NotApplicable,
 
+    /// The type relation have not been calculated.
+    Unknown,
+
     /// The relationship of the result's type to the expected type is not
     /// invalid, not convertible, and not identical.
     Unrelated,

lib/IDE/CodeCompletion.cpp

@@ -903,6 +903,9 @@ static CodeCompletionResult::ExpectedTypeRelation
 calculateMaxTypeRelationForDecl(
     const Decl *D, const ExpectedTypeContext &typeContext,
     bool IsImplicitlyCurriedInstanceMethod = false) {
+  if (typeContext.empty())
+    return CodeCompletionResult::ExpectedTypeRelation::Unknown;
+
   auto Result = CodeCompletionResult::ExpectedTypeRelation::Unrelated;
   for (auto Type : typeContext.possibleTypes) {
     // Do not use Void type context for a single-expression body, since the
@@ -1034,7 +1037,7 @@ CodeCompletionResult *CodeCompletionResultBuilder::takeResult() {
     }
 
     auto typeRelation = ExpectedTypeRelation;
-    if (typeRelation == CodeCompletionResult::Unrelated)
+    if (typeRelation == CodeCompletionResult::Unknown)
       typeRelation =
           calculateMaxTypeRelationForDecl(AssociatedDecl, declTypeContext);
 

lib/IDE/CodeCompletionResultBuilder.h

@@ -65,7 +65,7 @@ class CodeCompletionResultBuilder {
       CurrentModule;
   ExpectedTypeContext declTypeContext;
   CodeCompletionResult::ExpectedTypeRelation ExpectedTypeRelation =
-      CodeCompletionResult::Unrelated;
+      CodeCompletionResult::Unknown;
   bool Cancelled = false;
   ArrayRef<std::pair<StringRef, StringRef>> CommentWords;
   bool IsNotRecommended = false;

test/SourceKit/CodeComplete/complete_constructor.swift.response

@@ -7,7 +7,7 @@
       key.description: "(arg1: Int, arg2: Int)",
       key.typename: "Foo",
       key.context: source.codecompletion.context.thisclass,
-      key.typerelation: source.codecompletion.typerelation.unrelated,
+      key.typerelation: source.codecompletion.typerelation.unknown,
       key.num_bytes_to_erase: 0,
       key.associated_usrs: "s:20complete_constructor3FooC4arg14arg2ACSi_Sitcfc",
       key.modulename: "complete_constructor"

test/SourceKit/CodeComplete/complete_from_clang_module.swift

@@ -9,7 +9,7 @@ import Foo
 // CHECK-NEXT:       key.typename: "Int32",
 // CHECK-NEXT:       key.doc.brief: "Aaa.  fooIntVar.  Bbb.",
 // CHECK-NEXT:       key.context: source.codecompletion.context.othermodule,
-// CHECK-NEXT:       key.typerelation: source.codecompletion.typerelation.unrelated,
+// CHECK-NEXT:       key.typerelation: source.codecompletion.typerelation.unknown,
 // CHECK-NEXT:       key.num_bytes_to_erase: 0,
 // CHECK-NEXT:       key.associated_usrs: "c:@fooIntVar",
 // CHECK-NEXT:       key.modulename: "Foo"

test/SourceKit/CodeComplete/complete_member.swift.response

@@ -44,7 +44,7 @@
       key.description: "self",
       key.typename: "FooProtocol",
       key.context: source.codecompletion.context.thisclass,
-      key.typerelation: source.codecompletion.typerelation.unrelated,
+      key.typerelation: source.codecompletion.typerelation.unknown,
       key.num_bytes_to_erase: 0
     }
   ]

test/SourceKit/CodeComplete/complete_optionalmethod.swift.response

@@ -19,7 +19,7 @@
       key.description: "self",
       key.typename: "T",
       key.context: source.codecompletion.context.thisclass,
-      key.typerelation: source.codecompletion.typerelation.unrelated,
+      key.typerelation: source.codecompletion.typerelation.unknown,
       key.num_bytes_to_erase: 0
     }
   ]

test/SourceKit/CodeComplete/complete_typerelation.swift.convertible.response

@@ -56,7 +56,7 @@
       key.description: "self",
       key.typename: "MyEnum.Type",
       key.context: source.codecompletion.context.thisclass,
-      key.typerelation: source.codecompletion.typerelation.unrelated,
+      key.typerelation: source.codecompletion.typerelation.unknown,
       key.num_bytes_to_erase: 0
     },
     {
@@ -91,7 +91,7 @@
       key.description: "Type",
       key.typename: "MyEnum.Type",
       key.context: source.codecompletion.context.thisclass,
-      key.typerelation: source.codecompletion.typerelation.unrelated,
+      key.typerelation: source.codecompletion.typerelation.unknown,
       key.num_bytes_to_erase: 0
     }
   ]

test/SourceKit/CodeComplete/complete_typerelation.swift.identical.response

@@ -56,7 +56,7 @@
       key.description: "self",
       key.typename: "MyEnum.Type",
       key.context: source.codecompletion.context.thisclass,
-      key.typerelation: source.codecompletion.typerelation.unrelated,
+      key.typerelation: source.codecompletion.typerelation.unknown,
       key.num_bytes_to_erase: 0
     },
     {
@@ -91,7 +91,7 @@
       key.description: "Type",
       key.typename: "MyEnum.Type",
       key.context: source.codecompletion.context.thisclass,
-      key.typerelation: source.codecompletion.typerelation.unrelated,
+      key.typerelation: source.codecompletion.typerelation.unknown,
       key.num_bytes_to_erase: 0
     }
   ]

tools/SourceKit/lib/SwiftLang/SwiftCompletion.cpp

@@ -503,6 +503,7 @@ bool SwiftToSourceKitCompletionAdapter::handleResult(
   }
 
   static UIdent CCTypeRelNotApplicable("source.codecompletion.typerelation.notapplicable");
+  static UIdent CCTypeRelUnknown("source.codecompletion.typerelation.unknown");
   static UIdent CCTypeRelUnrelated("source.codecompletion.typerelation.unrelated");
   static UIdent CCTypeRelInvalid("source.codecompletion.typerelation.invalid");
   static UIdent CCTypeRelConvertible("source.codecompletion.typerelation.convertible");
@@ -511,6 +512,8 @@ bool SwiftToSourceKitCompletionAdapter::handleResult(
   switch (Result->getExpectedTypeRelation()) {
   case CodeCompletionResult::NotApplicable:
     Info.TypeRelation = CCTypeRelNotApplicable; break;
+  case CodeCompletionResult::Unknown:
+    Info.TypeRelation = CCTypeRelUnknown; break;
   case CodeCompletionResult::Unrelated:
     Info.TypeRelation = CCTypeRelUnrelated; break;
   case CodeCompletionResult::Invalid: