[Parser] Ignore generic arguments after a code completion token

Author: ahoppen

lib/Parse/ParseExpr.cpp

@@ -1760,6 +1760,11 @@ ParserResult<Expr> Parser::parseExprPrimary(Diag<> ID, bool isExprBasic) {
       }
     }
     consumeToken(tok::code_complete);
+    if (canParseAsGenericArgumentList()) {
+      SmallVector<TypeRepr*, 8> args;
+      SourceLoc LAngleLoc, RAngleLoc;
+      parseGenericArguments(args, LAngleLoc, RAngleLoc);
+    }
     return Result;
   }
 

test/IDE/complete_constructor.swift

@@ -361,3 +361,19 @@ func testInitWithUnresolved() {
 // INIT_WITH_UNRESOLVEDTYPE_1-DAG: Decl[Constructor]/CurrNominal/Flair[ArgLabels]:      ['(']{#arg2: _#}[')'][#InitWithUnresolved<_>#];
 // INIT_WITH_UNRESOLVEDTYPE_1: End completions
 }
+
+func testIgnoreGenericArgsAfterCompletionToken() {
+  struct IPv4 {}
+
+  public struct HostRecord<IPType> {
+    init(position: inout Int) throws {}
+  }
+
+  func deserializeRecord() throws -> HostRecord<IPv4> {
+    var position = 42
+    return try #^IGNORE_GENERIC_ARGS_AFTER_COMPLETION_TOKEN^#HostRecord<IPv4>(position: &position)
+// IGNORE_GENERIC_ARGS_AFTER_COMPLETION_TOKEN: Begin completions
+// IGNORE_GENERIC_ARGS_AFTER_COMPLETION_TOKEN-DAG: Decl[Struct]/Local: HostRecord[#HostRecord#];
+// IGNORE_GENERIC_ARGS_AFTER_COMPLETION_TOKEN: End completions
+  }
+}