Merge pull request #37037 from ahoppen/pr/vararg-label-completion

[CodeCompletion] Fix code suggestions for arguments in vararg followed by normal arg

Author: ahoppen

lib/IDE/ExprContextAnalysis.cpp

@@ -795,6 +795,12 @@ static bool getPositionInParams(DeclContext &DC, Expr *Args, Expr *CCExpr,
     if (!SM.isBeforeInBuffer(tuple->getElement(PosInArgs)->getEndLoc(),
                              CCExpr->getStartLoc())) {
       // The arg is after the code completion position. Stop.
+      if (LastParamWasVariadic && tuple->getElementName(PosInArgs).empty()) {
+        // If the last parameter was variadic and this argument stands by itself
+        // without a label, assume that it belongs to the previous vararg
+        // list.
+        PosInParams--;
+      }
       break;
     }
 

test/IDE/complete_call_arg.swift

@@ -865,6 +865,9 @@ func testCompleteLabelAfterVararg() {
   enum Foo {
     case bar
   }
+  enum Baz {
+    case bazCase
+  }
 
   struct Rdar76355192 {
     func test(_: String, xArg: Foo..., yArg: Foo..., zArg: Foo...) {}
@@ -887,6 +890,37 @@ func testCompleteLabelAfterVararg() {
     // COMPLETE_MEMBER_IN_VARARG-DAG: Decl[InstanceMethod]/CurrNominal/TypeRelation[Invalid]: hash({#(self): Foo#})[#(into: inout Hasher) -> Void#];
     // COMPLETE_MEMBER_IN_VARARG: End completions
   }
+
+  struct Sr14515 {
+    func test(_: Foo..., yArg: Baz) {}
+  }
+
+  private func testSr14515(value: Sr14515, foo: Foo, baz: Baz) {
+    value.test(foo, #^COMPLETE_VARARG_FOLLOWED_BY_NORMAL_ARG^#)
+    // COMPLETE_VARARG_FOLLOWED_BY_NORMAL_ARG: Begin completions
+    // COMPLETE_VARARG_FOLLOWED_BY_NORMAL_ARG-DAG: Decl[LocalVar]/Local/TypeRelation[Identical]: foo[#Foo#];
+    // COMPLETE_VARARG_FOLLOWED_BY_NORMAL_ARG-DAG: Pattern/ExprSpecific:               {#yArg: Baz#}[#Baz#];
+    // COMPLETE_VARARG_FOLLOWED_BY_NORMAL_ARG: End completions
+
+    // The leading dot completion tests that have picked the right type for the argument
+    value.test(foo, .#^COMPLETE_VARARG_FOLLOWED_BY_NORMAL_ARG_DOT^#)
+    // COMPLETE_VARARG_FOLLOWED_BY_NORMAL_ARG_DOT: Begin completions, 2 items
+    // COMPLETE_VARARG_FOLLOWED_BY_NORMAL_ARG_DOT-DAG: Decl[EnumElement]/ExprSpecific/TypeRelation[Identical]: bar[#Foo#];
+    // COMPLETE_VARARG_FOLLOWED_BY_NORMAL_ARG_DOT-DAG: Decl[InstanceMethod]/CurrNominal/TypeRelation[Invalid]: hash({#(self): Foo#})[#(into: inout Hasher) -> Void#];
+    // COMPLETE_VARARG_FOLLOWED_BY_NORMAL_ARG_DOT: End completions
+
+    value.test(foo, yArg: #^COMPLETE_ARG_AFTER_VARARG^#)
+    // COMPLETE_ARG_AFTER_VARARG: Begin completions
+    // COMPLETE_ARG_AFTER_VARARG-DAG: Decl[LocalVar]/Local/TypeRelation[Identical]: baz[#Baz#];
+    // COMPLETE_ARG_AFTER_VARARG-NOT: Pattern/ExprSpecific:               {#yArg: Baz#}[#Baz#];
+    // COMPLETE_ARG_AFTER_VARARG: End completions
+
+    value.test(foo, yArg: .#^COMPLETE_ARG_AFTER_VARARG_DOT^#)
+    // COMPLETE_ARG_AFTER_VARARG_DOT: Begin completions, 2 items
+    // COMPLETE_ARG_AFTER_VARARG_DOT-DAG: Decl[EnumElement]/ExprSpecific/TypeRelation[Identical]: bazCase[#Baz#];
+    // COMPLETE_ARG_AFTER_VARARG_DOT-DAG: Decl[InstanceMethod]/CurrNominal/TypeRelation[Invalid]: hash({#(self): Baz#})[#(into: inout Hasher) -> Void#];
+    // COMPLETE_ARG_AFTER_VARARG_DOT: End completions
+  }
 }
 
 func testGenericConstructor() {