Merge pull request #23502 from rintaro/ide-completion-unresolvedoptional-rdar47806831

[CodeCompletion] Don't provide 'init(nilLiteral:)' et al in optional context

Author: rintaro

lib/IDE/CodeCompletion.cpp

@@ -2725,7 +2725,8 @@ class CompletionLookup final : public swift::VisibleDeclConsumer {
   void addKeyword(StringRef Name, Type TypeAnnotation = Type(),
                   SemanticContextKind SK = SemanticContextKind::None,
                   CodeCompletionKeywordKind KeyKind
-                    = CodeCompletionKeywordKind::None) {
+                    = CodeCompletionKeywordKind::None,
+                  unsigned NumBytesToErase = 0) {
     CodeCompletionResultBuilder Builder(
         Sink, CodeCompletionResult::ResultKind::Keyword, SK,
         expectedTypeContext);
@@ -2734,6 +2735,8 @@ class CompletionLookup final : public swift::VisibleDeclConsumer {
     Builder.setKeywordKind(KeyKind);
     if (TypeAnnotation)
       addTypeAnnotation(Builder, TypeAnnotation);
+    if (NumBytesToErase > 0)
+      Builder.setNumBytesToErase(NumBytesToErase);
   }
 
   void addKeyword(StringRef Name, StringRef TypeAnnotation,
@@ -3622,6 +3625,15 @@ class CompletionLookup final : public swift::VisibleDeclConsumer {
           return false;
       }
 
+      if (T->getOptionalObjectType() &&
+          VD->getModuleContext()->isStdlibModule()) {
+        // In optional context, ignore '.init(<some>)', 'init(nilLiteral:)',
+        if (isa<ConstructorDecl>(VD))
+          return false;
+        // TODO: Ignore '.some(<Wrapped>)' and '.none' too *in expression
+        // context*. They are useful in pattern context though.
+      }
+
       // Enum element decls can always be referenced by implicit member
       // expression.
       if (isa<EnumElementDecl>(VD))
@@ -3692,6 +3704,14 @@ class CompletionLookup final : public swift::VisibleDeclConsumer {
         // If this is optional type, perform completion for the object type.
         // i.e. 'let _: Enum??? = .enumMember' is legal.
         getUnresolvedMemberCompletions(objT->lookThroughAllOptionalTypes());
+
+        // Add 'nil' keyword with erasing '.' instruction.
+        unsigned bytesToErase = 0;
+        auto &SM = CurrDeclContext->getASTContext().SourceMgr;
+        if (DotLoc.isValid())
+          bytesToErase = SM.getByteDistance(DotLoc, SM.getCodeCompletionLoc());
+        addKeyword("nil", T, SemanticContextKind::ExpressionSpecific,
+                   CodeCompletionKeywordKind::kw_nil, bytesToErase);
       }
       getUnresolvedMemberCompletions(T);
     }

test/IDE/complete_unresolved_members.swift

@@ -14,6 +14,7 @@
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=UNRESOLVED_OPT_1 | %FileCheck %s -check-prefix=UNRESOLVED_3_OPT
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=UNRESOLVED_OPT_2 | %FileCheck %s -check-prefix=UNRESOLVED_3_OPT
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=UNRESOLVED_OPT_3 | %FileCheck %s -check-prefix=UNRESOLVED_3_OPTOPTOPT
+// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=UNRESOLVED_OPT_4 | %FileCheck %s -check-prefix=UNRESOLVED_OPT_4
 
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=UNRESOLVED_12 | %FileCheck %s -check-prefix=UNRESOLVED_3
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=UNRESOLVED_13 | %FileCheck %s -check-prefix=UNRESOLVED_3
@@ -241,29 +242,54 @@ class C4 {
     var _: SomeEnum1??? = .#^UNRESOLVED_OPT_3^#
   }
 }
-// UNRESOLVED_3: Begin completions
+// UNRESOLVED_3: Begin completions, 2 items
 // UNRESOLVED_3-DAG: Decl[EnumElement]/ExprSpecific:     North[#SomeEnum1#]; name=North
 // UNRESOLVED_3-DAG: Decl[EnumElement]/ExprSpecific:     South[#SomeEnum1#]; name=South
 // UNRESOLVED_3-NOT: SomeOptions1
 // UNRESOLVED_3-NOT: SomeOptions2
 // UNRESOLVED_3-NOT: none
 // UNRESOLVED_3-NOT: some(
 
-// UNRESOLVED_3_OPT: Begin completions
+// UNRESOLVED_3_OPT: Begin completions, 5 items
 // UNRESOLVED_3_OPT-DAG: Decl[EnumElement]/ExprSpecific:     North[#SomeEnum1#];
 // UNRESOLVED_3_OPT-DAG: Decl[EnumElement]/ExprSpecific:     South[#SomeEnum1#];
+// UNRESOLVED_3_OPT-DAG: Keyword[nil]/ExprSpecific/Erase[1]: nil[#SomeEnum1?#]; name=nil
 // UNRESOLVED_3_OPT-DAG: Decl[EnumElement]/ExprSpecific:     none[#Optional<SomeEnum1>#]; name=none
 // UNRESOLVED_3_OPT-DAG: Decl[EnumElement]/ExprSpecific:     some({#SomeEnum1#})[#Optional<SomeEnum1>#];
-// UNRESOLVED_3_OPT-DAG: Decl[Constructor]/CurrNominal:      init({#(some): SomeEnum1#})[#Optional<SomeEnum1>#];
-// UNRESOLVED_3_OPT-DAG: Decl[Constructor]/CurrNominal:      init({#nilLiteral: ()#})[#Optional<SomeEnum1>#];
+// UNRESOLVED_3_OPT-NOT: init({#(some):
+// UNRESOLVED_3_OPT-NOT: init({#nilLiteral:
 
-// UNRESOLVED_3_OPTOPTOPT: Begin completions
+// UNRESOLVED_3_OPTOPTOPT: Begin completions, 5 items
 // UNRESOLVED_3_OPTOPTOPT-DAG: Decl[EnumElement]/ExprSpecific:     North[#SomeEnum1#];
 // UNRESOLVED_3_OPTOPTOPT-DAG: Decl[EnumElement]/ExprSpecific:     South[#SomeEnum1#];
+// UNRESOLVED_3_OPTOPTOPT-DAG: Keyword[nil]/ExprSpecific/Erase[1]: nil[#SomeEnum1???#]; name=nil
 // UNRESOLVED_3_OPTOPTOPT-DAG: Decl[EnumElement]/ExprSpecific:     none[#Optional<SomeEnum1??>#]; name=none
 // UNRESOLVED_3_OPTOPTOPT-DAG: Decl[EnumElement]/ExprSpecific:     some({#SomeEnum1??#})[#Optional<SomeEnum1??>#];
-// UNRESOLVED_3_OPTOPTOPT-DAG: Decl[Constructor]/CurrNominal:      init({#(some): SomeEnum1??#})[#Optional<SomeEnum1??>#];
-// UNRESOLVED_3_OPTOPTOPT-DAG: Decl[Constructor]/CurrNominal:      init({#nilLiteral: ()#})[#Optional<SomeEnum1??>#];
+// UNRESOLVED_3_OPTOPTOPT-NOT: init({#(some):
+// UNRESOLVED_3_OPTOPTOPT-NOT: init({#nilLiteral:
+
+enum Somewhere {
+  case earth, mars
+}
+extension Optional where Wrapped == Somewhere {
+  init(str: String) { fatalError() }
+  static var nowhere: Self { return nil }
+}
+func testOptionalWithCustomExtension() {
+  var _: Somewhere? = .#^UNRESOLVED_OPT_4^#
+// UNRESOLVED_OPT_4: Begin completions, 7 items
+// UNRESOLVED_OPT_4-DAG: Decl[EnumElement]/ExprSpecific:     earth[#Somewhere#];
+// UNRESOLVED_OPT_4-DAG: Decl[EnumElement]/ExprSpecific:     mars[#Somewhere#];
+// UNRESOLVED_OPT_4-DAG: Keyword[nil]/ExprSpecific/Erase[1]: nil[#Somewhere?#]; name=nil
+// UNRESOLVED_OPT_4-DAG: Decl[EnumElement]/ExprSpecific:     none[#Optional<Somewhere>#]; name=none
+// UNRESOLVED_OPT_4-DAG: Decl[EnumElement]/ExprSpecific:     some({#Somewhere#})[#Optional<Somewhere>#];
+// UNRESOLVED_OPT_4-DAG: Decl[Constructor]/CurrNominal:      init({#str: String#})[#Optional<Somewhere>#]; name=init(str: String)
+// UNRESOLVED_OPT_4-DAG: Decl[StaticVar]/CurrNominal/TypeRelation[Identical]: nowhere[#Optional<Somewhere>#]; name=nowhere
+// UNRESOLVED_OPT_4-NOT: init({#(some):
+// UNRESOLVED_OPT_4-NOT: init({#nilLiteral:
+// UNRESOLVED_OPT_4: End completions
+}
+
 
 class C5 {
   func f1() {