[5.6] Use the API Name of Enum Parameters to Determine Coding Keys

lib/Sema/DerivedConformanceCodable.cpp

@@ -54,7 +54,13 @@ static bool superclassConformsTo(ClassDecl *target, KnownProtocolKind kpk) {
 static Identifier getVarNameForCoding(VarDecl *var,
                                       Optional<int> paramIndex = None) {
   auto &C = var->getASTContext();
-  Identifier identifier = var->getName();
+  Identifier identifier;
+  if (auto *PD = dyn_cast<ParamDecl>(var)) {
+    identifier = PD->getArgumentName();
+  } else {
+    identifier = var->getName();
+  }
+
   if (auto originalVar = var->getOriginalWrappedProperty())
     identifier = originalVar->getName();
 

test/decl/protocol/special/coding/enum_codable_simple.swift

@@ -6,6 +6,7 @@ enum SimpleEnum : Codable {
     case a(x: Int, y: Double)
     case b(z: String)
     case c(Int, String, b: Bool)
+    case d(_ inner: Int)
 
     // These lines have to be within the SimpleEnum type because CodingKeys
     // should be private.
@@ -15,6 +16,7 @@ enum SimpleEnum : Codable {
         let _ = SimpleEnum.ACodingKeys.self
         let _ = SimpleEnum.BCodingKeys.self
         let _ = SimpleEnum.CCodingKeys.self
+        let _ = SimpleEnum.DCodingKeys.self
 
         // The enum should have a case for each of the cases.
         let _ = SimpleEnum.CodingKeys.a
@@ -29,6 +31,8 @@ enum SimpleEnum : Codable {
         let _ = SimpleEnum.CCodingKeys._0
         let _ = SimpleEnum.CCodingKeys._1
         let _ = SimpleEnum.CCodingKeys.b
+
+        let _ = SimpleEnum.DCodingKeys._0
     }
 }
 

validation-test/compiler_crashers_2_fixed/rdar86339848.swift

@@ -0,0 +1,7 @@
+// RUN: %target-swift-frontend %s -emit-silgen
+
+struct Boom: Decodable {}
+
+enum Whiz: Decodable {
+  case bang(_ boom: Boom)
+}