[Sema] Support code completion for heterogeneous unresolved member chains

Author: Jumhyn

lib/Sema/TypeCheckConstraints.cpp

@@ -491,6 +491,8 @@ static Expr *getMemberChainSubExpr(Expr *expr) {
     return FVE->getSubExpr();
   } else if (auto *SE = dyn_cast<SubscriptExpr>(expr)) {
     return SE->getBase();
+  } else if (auto *CCE = dyn_cast<CodeCompletionExpr>(expr)) {
+    return CCE->getBase();
   } else {
     return nullptr;
   }

test/IDE/complete_unresolved_chains.swift

@@ -0,0 +1,79 @@
+// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=UNRESOLVED_CHAIN_1 | %FileCheck %s -check-prefix=UNRESOLVED_CHAIN_1
+// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=UNRESOLVED_CHAIN_2 | %FileCheck %s -check-prefix=UNRESOLVED_CHAIN_1
+// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=UNRESOLVED_CHAIN_3 | %FileCheck %s -check-prefix=UNRESOLVED_CHAIN_1
+// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=UNRESOLVED_CHAIN_4 | %FileCheck %s -check-prefix=UNRESOLVED_CHAIN_1
+// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=UNRESOLVED_CHAIN_5 | %FileCheck %s -check-prefix=UNRESOLVED_CHAIN_2
+// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=UNRESOLVED_CHAIN_6 | %FileCheck %s -check-prefix=UNRESOLVED_CHAIN_3
+// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=UNRESOLVED_CHAIN_7 | %FileCheck %s -check-prefix=UNRESOLVED_CHAIN_3
+// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=DOUBLY_NESTED| %FileCheck %s -check-prefix=DOUBLY_NESTED
+
+struct ChainStruct1 {
+  static var chain2 = ChainStruct2()
+  static func chain2Func() -> ChainStruct2 { ChainStruct2() }
+}
+
+struct ChainStruct2 {
+  var chainStruct1 = ChainStruct1()
+  var chainEnum = ChainEnum.case1
+  var chainStruct2: ChainStruct2 { ChainStruct2() }
+  func chainStruct1Func() -> ChainStruct1 { ChainStruct1() }
+}
+
+enum ChainEnum {
+  case case1
+  var chainStruct2: ChainStruct2 { ChainStruct2() }
+  func chainStruct2Func() -> ChainStruct2 { ChainStruct2() }
+}
+
+func testChains() {
+  let _: ChainStruct1 = .chain2.#^UNRESOLVED_CHAIN_1^#
+  let _: ChainStruct1 = .chain2.chainStruct2.#^UNRESOLVED_CHAIN_2^#
+  let _: ChainStruct1 = .chain2Func().#^UNRESOLVED_CHAIN_3^#
+  let _: ChainStruct1 = .chain2Func().#^UNRESOLVED_CHAIN_4^#
+  let _: ChainEnum = .case1.#^UNRESOLVED_CHAIN_5^#
+  let _: ChainEnum = .case1.chainStruct2.#^UNRESOLVED_CHAIN_6^#
+  let _: ChainEnum = .case1.chainStruct2.#^UNRESOLVED_CHAIN_7^#
+}
+
+// UNRESOLVED_CHAIN_1: Begin completions, 5 items
+// UNRESOLVED_CHAIN_1-DAG: Decl[InstanceVar]/CurrNominal/TypeRelation[Identical]: chainStruct1[#ChainStruct1#];
+// UNRESOLVED_CHAIN_1-DAG: Decl[InstanceVar]/CurrNominal:      chainEnum[#ChainEnum#];
+// UNRESOLVED_CHAIN_1-DAG: Decl[InstanceVar]/CurrNominal:      chainStruct2[#ChainStruct2#];
+// UNRESOLVED_CHAIN_1-DAG: Decl[InstanceMethod]/CurrNominal/TypeRelation[Identical]: chainStruct1Func()[#ChainStruct1#];
+// UNRESOLVED_CHAIN_1: End completions
+
+// UNRESOLVED_CHAIN_2: Begin completions, 5 items
+// UNRESOLVED_CHAIN_2-DAG: Decl[InstanceVar]/CurrNominal:      chainStruct2[#ChainStruct2#];
+// UNRESOLVED_CHAIN_2: End completions
+
+// UNRESOLVED_CHAIN_3: Begin completions, 5 items
+// UNRESOLVED_CHAIN_3-DAG: Decl[InstanceVar]/CurrNominal:      chainStruct1[#ChainStruct1#]; name=chainStruct1
+// UNRESOLVED_CHAIN_3-DAG: Decl[InstanceVar]/CurrNominal/TypeRelation[Identical]: chainEnum[#ChainEnum#]; name=chainEnum
+// UNRESOLVED_CHAIN_3-DAG: Decl[InstanceVar]/CurrNominal:      chainStruct2[#ChainStruct2#]; name=chainStruct2
+// UNRESOLVED_CHAIN_3-DAG: Decl[InstanceMethod]/CurrNominal:   chainStruct1Func()[#ChainStruct1#]; name=chainStruct1Func()
+// UNRESOLVED_CHAIN_3: End completions
+
+class Outer {
+  class Inner: Outer {
+    class InnerInner: Inner {}
+    static var outer = Outer()
+    static var inner = Inner()
+    static func makeOuter() -> Outer { Outer() }
+    static func makeInner() -> Inner { Inner() }
+  }
+}
+
+func testDoublyNestedType() {
+    let _: Outer = .Inner.#^DOUBLY_NESTED^#
+}
+
+// DOUBLY_NESTED: Begin completions, 8 items
+// DOUBLY_NESTED-DAG: Decl[Class]/CurrNominal/TypeRelation[Convertible]: InnerInner[#Outer.Inner.InnerInner#];
+// DOUBLY_NESTED-DAG: Decl[StaticVar]/CurrNominal/TypeRelation[Identical]: outer[#Outer#];
+// DOUBLY_NESTED-DAG: Decl[StaticVar]/CurrNominal/TypeRelation[Convertible]: inner[#Outer.Inner#];
+// DOUBLY_NESTED-DAG: Decl[StaticMethod]/CurrNominal/TypeRelation[Identical]: makeOuter()[#Outer#];
+// DOUBLY_NESTED-DAG: Decl[StaticMethod]/CurrNominal/TypeRelation[Convertible]: makeInner()[#Outer.Inner#];
+// DOUBLY_NESTED-DAG: Decl[Constructor]/CurrNominal/TypeRelation[Convertible]: init()[#Outer.Inner#];
+// DOUBLY_NESTED-DAG: Decl[Class]/Super/TypeRelation[Convertible]: Inner[#Outer.Inner#];
+// DOUBLY_NESTED: End completions
+