From a9443a427b957d62d055756a36e11ceb199111bd Mon Sep 17 00:00:00 2001
From: Aaron J Todd <todaaron@amazon.com>
Date: Fri, 23 Feb 2024 14:02:50 -0500
Subject: [PATCH 01/11] refactor xml protocol deserialization

---
 .../s3/UnwrappedXmlOutputIntegration.kt       |  15 +--
 .../s3/UnwrappedXmlOutputIntegrationTest.kt   |  30 -----
 .../kotlin/codegen/aws/protocols/AwsQuery.kt  | 119 +++++++++---------
 .../kotlin/codegen/aws/protocols/Ec2Query.kt  |  97 +++++++++-----
 .../kotlin/codegen/aws/protocols/RestXml.kt   | 104 ++++++++++++++-
 gradle/libs.versions.toml                     |   4 +-
 6 files changed, 244 insertions(+), 125 deletions(-)
 delete mode 100644 codegen/aws-sdk-codegen/src/test/kotlin/aws/sdk/kotlin/codegen/customization/s3/UnwrappedXmlOutputIntegrationTest.kt

diff --git a/codegen/aws-sdk-codegen/src/main/kotlin/aws/sdk/kotlin/codegen/customization/s3/UnwrappedXmlOutputIntegration.kt b/codegen/aws-sdk-codegen/src/main/kotlin/aws/sdk/kotlin/codegen/customization/s3/UnwrappedXmlOutputIntegration.kt
index d51f70624f0..42cca196eb6 100644
--- a/codegen/aws-sdk-codegen/src/main/kotlin/aws/sdk/kotlin/codegen/customization/s3/UnwrappedXmlOutputIntegration.kt
+++ b/codegen/aws-sdk-codegen/src/main/kotlin/aws/sdk/kotlin/codegen/customization/s3/UnwrappedXmlOutputIntegration.kt
@@ -11,31 +11,32 @@ import software.amazon.smithy.kotlin.codegen.model.expectShape
 import software.amazon.smithy.kotlin.codegen.model.hasTrait
 import software.amazon.smithy.kotlin.codegen.model.traits.UnwrappedXmlOutput
 import software.amazon.smithy.model.Model
+import software.amazon.smithy.model.shapes.OperationShape
 import software.amazon.smithy.model.shapes.ServiceShape
-import software.amazon.smithy.model.shapes.StructureShape
 import software.amazon.smithy.model.transform.ModelTransformer
 
 /**
- * Applies the [UnwrappedXmlOutput] custom-made [annotation trait](https://smithy.io/2.0/spec/model.html?highlight=annotation#annotation-traits) to structures
- * whose operation is annotated with `S3UnwrappedXmlOutput` trait to mark when special unwrapped xml output deserialization is required.
+ * Applies the custom [UnwrappedXmlOutput]
+ * [annotation trait](https://smithy.io/2.0/spec/model.html?highlight=annotation#annotation-traits) to operations
+ * annotated with `S3UnwrappedXmlOutput` trait to mark when special unwrapped xml output deserialization is required.
  */
 class UnwrappedXmlOutputIntegration : KotlinIntegration {
     override fun enabledForService(model: Model, settings: KotlinSettings): Boolean =
         model.expectShape<ServiceShape>(settings.service).isS3
 
     override fun preprocessModel(model: Model, settings: KotlinSettings): Model {
-        val unwrappedStructures = model
+        val unwrappedOperations = model
             .operationShapes
             .filter { it.hasTrait<S3UnwrappedXmlOutputTrait>() }
-            .map { it.outputShape }
+            .map { it.id }
             .toSet()
 
         return ModelTransformer
             .create()
             .mapShapes(model) { shape ->
                 when {
-                    shape.id in unwrappedStructures ->
-                        (shape as StructureShape).toBuilder().addTrait(UnwrappedXmlOutput()).build()
+                    shape.id in unwrappedOperations ->
+                        (shape as OperationShape).toBuilder().addTrait(UnwrappedXmlOutput()).build()
                     else -> shape
                 }
             }
diff --git a/codegen/aws-sdk-codegen/src/test/kotlin/aws/sdk/kotlin/codegen/customization/s3/UnwrappedXmlOutputIntegrationTest.kt b/codegen/aws-sdk-codegen/src/test/kotlin/aws/sdk/kotlin/codegen/customization/s3/UnwrappedXmlOutputIntegrationTest.kt
deleted file mode 100644
index 7827fed4915..00000000000
--- a/codegen/aws-sdk-codegen/src/test/kotlin/aws/sdk/kotlin/codegen/customization/s3/UnwrappedXmlOutputIntegrationTest.kt
+++ /dev/null
@@ -1,30 +0,0 @@
-/*
- * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-package aws.sdk.kotlin.codegen.customization.s3
-
-import aws.sdk.kotlin.codegen.testutil.model
-import org.junit.jupiter.api.Assertions.assertFalse
-import org.junit.jupiter.api.Test
-import software.amazon.smithy.kotlin.codegen.test.defaultSettings
-import kotlin.test.assertTrue
-
-/**
- * Verify [UnwrappedXmlOutputIntegration] is enabled for proper service (S3)
- */
-class UnwrappedXmlOutputIntegrationTest {
-    @Test
-    fun testNonS3Model() {
-        val model = model("NotS3")
-        val actual = UnwrappedXmlOutputIntegration().enabledForService(model, model.defaultSettings())
-        assertFalse(actual)
-    }
-
-    @Test
-    fun testS3Model() {
-        val model = model("S3")
-        val actual = UnwrappedXmlOutputIntegration().enabledForService(model, model.defaultSettings())
-        assertTrue(actual)
-    }
-}
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
index 5aed86cb8c2..4ed06644ca2 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
@@ -12,11 +12,10 @@ import software.amazon.smithy.kotlin.codegen.aws.protocols.core.AwsHttpBindingPr
 import software.amazon.smithy.kotlin.codegen.aws.protocols.core.QueryHttpBindingProtocolGenerator
 import software.amazon.smithy.kotlin.codegen.aws.protocols.formurl.QuerySerdeFormUrlDescriptorGenerator
 import software.amazon.smithy.kotlin.codegen.core.*
+import software.amazon.smithy.kotlin.codegen.lang.KotlinTypes
 import software.amazon.smithy.kotlin.codegen.model.*
-import software.amazon.smithy.kotlin.codegen.model.traits.OperationOutput
 import software.amazon.smithy.kotlin.codegen.rendering.protocol.*
 import software.amazon.smithy.kotlin.codegen.rendering.serde.*
-import software.amazon.smithy.kotlin.codegen.utils.dq
 import software.amazon.smithy.model.shapes.*
 import software.amazon.smithy.model.traits.*
 
@@ -68,24 +67,6 @@ private class AwsQuerySerdeFormUrlDescriptorGenerator(
         member.hasTrait<XmlFlattenedTrait>()
 }
 
-private class AwsQuerySerdeXmlDescriptorGenerator(
-    ctx: RenderingContext<Shape>,
-    memberShapes: List<MemberShape>? = null,
-) : XmlSerdeDescriptorGenerator(ctx, memberShapes) {
-
-    override fun getObjectDescriptorTraits(): List<SdkFieldDescriptorTrait> {
-        val traits = super.getObjectDescriptorTraits().toMutableList()
-
-        if (objectShape.hasTrait<OperationOutput>()) {
-            traits.removeIf { it.symbol == RuntimeTypes.Serde.SerdeXml.XmlSerialName }
-            val serialName = objectShape.changeNameSuffix("Response" to "Result")
-            traits.add(RuntimeTypes.Serde.SerdeXml.XmlSerialName, serialName.dq())
-        }
-
-        return traits
-    }
-}
-
 private class AwsQuerySerializerGenerator(
     private val protocolGenerator: AwsQuery,
 ) : AbstractQueryFormUrlSerializerGenerator(protocolGenerator, protocolGenerator.defaultTimestampFormat) {
@@ -98,50 +79,76 @@ private class AwsQuerySerializerGenerator(
 }
 
 private class AwsQueryXmlParserGenerator(
-    private val protocolGenerator: AwsQuery,
+    protocolGenerator: AwsQuery,
 ) : XmlParserGenerator(protocolGenerator, protocolGenerator.defaultTimestampFormat) {
 
-    override fun descriptorGenerator(
-        ctx: ProtocolGenerator.GenerationContext,
-        shape: Shape,
-        members: List<MemberShape>,
-        writer: KotlinWriter,
-    ): XmlSerdeDescriptorGenerator = AwsQuerySerdeXmlDescriptorGenerator(ctx.toRenderingContext(protocolGenerator, shape, writer), members)
-
-    override fun renderDeserializeOperationBody(
-        ctx: ProtocolGenerator.GenerationContext,
-        op: OperationShape,
-        documentMembers: List<MemberShape>,
-        writer: KotlinWriter,
-    ) {
-        writer.write("val deserializer = #T(payload)", RuntimeTypes.Serde.SerdeXml.XmlDeserializer)
-        unwrapOperationResponseBody(op.id.name, writer)
-        val shape = ctx.model.expectShape(op.output.get())
-        renderDeserializerBody(ctx, shape, documentMembers, writer)
-    }
-
     /**
      * Unwraps the response body as specified by
      * https://awslabs.github.io/smithy/1.0/spec/aws/aws-query-protocol.html#response-serialization so that the
      * deserializer is in the correct state.
+     *
+     * ```
+     * <SomeOperationResponse>
+     *     <SomeOperationResult>
+     *          <-- SAME AS REST XML -->
+     *     </SomeOperationResult>
+     *</SomeOperationResponse>
+     * ```
      */
-    private fun unwrapOperationResponseBody(
-        operationName: String,
+    override fun unwrapOperationBody(
+        ctx: ProtocolGenerator.GenerationContext,
+        serdeCtx: SerdeCtx,
+        op: OperationShape,
         writer: KotlinWriter,
-    ) {
-        writer.write("// begin unwrap response wrapper")
-            .write("val resultDescriptor = #T(#T.Struct, #T(#S))", RuntimeTypes.Serde.SdkFieldDescriptor, RuntimeTypes.Serde.SerialKind, RuntimeTypes.Serde.SerdeXml.XmlSerialName, "${operationName}Result")
-            .withBlock("val wrapperDescriptor = #T.build {", "}", RuntimeTypes.Serde.SdkObjectDescriptor) {
-                write("trait(#T(#S))", RuntimeTypes.Serde.SerdeXml.XmlSerialName, "${operationName}Response")
-                write("#T(resultDescriptor)", RuntimeTypes.Serde.field)
+    ): SerdeCtx {
+        val operationName = op.id.getName(ctx.service)
+
+        val unwrapAwsQueryOperation = buildSymbol {
+            name = "unwrapAwsQueryResponse"
+            namespace = ctx.settings.pkg.serde
+            definitionFile = "AwsQueryUtil.kt"
+            renderBy = { writer ->
+
+                writer.withBlock(
+                    "internal fun $name(root: #1T, operationName: #2T): #1T {",
+                    "}",
+                    RuntimeTypes.Serde.SerdeXml.TagReader,
+                    KotlinTypes.String,
+                ) {
+                    write("val responseWrapperName = \"\${operationName}Response\"")
+                    write("val resultWrapperName = \"\${operationName}Result\"")
+                    withBlock(
+                        "if (root.startTag.name.tag != responseWrapperName) {",
+                        "}",
+                    ) {
+                        write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid root, expected \$responseWrapperName; found `\${root.startTag}`")
+                    }
+
+                    write("val resultTag = ${serdeCtx.tagReader}.nextTag()")
+                    withBlock(
+                        "if (resultTag == null || resultTag.startTag.name.tag != resultWrapperName) {",
+                        "}",
+                    ) {
+                        write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid result, expected \$resultWrapperName; found `\${resultTag?.startTag}`")
+                    }
+
+                    write("return resultTag")
+                }
             }
-            .write("")
-            // abandon the iterator, this only occurs at the top level operational output
-            .write("val wrapper = deserializer.#T(wrapperDescriptor)", RuntimeTypes.Serde.deserializeStruct)
-            .withBlock("if (wrapper.findNextFieldIndex() != resultDescriptor.index) {", "}") {
-                write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "failed to unwrap $operationName response")
-            }
-            .write("// end unwrap response wrapper")
-            .write("")
+        }
+
+        writer.write("val unwrapped = #T(#L, #S)", unwrapAwsQueryOperation, serdeCtx.tagReader, operationName)
+
+        return SerdeCtx("unwrapped")
+    }
+
+    override fun unwrapOperationError(
+        ctx: ProtocolGenerator.GenerationContext,
+        serdeCtx: SerdeCtx,
+        errorShape: StructureShape,
+        writer: KotlinWriter,
+    ): SerdeCtx {
+        writer.write("val errReader = #T(${serdeCtx.tagReader})", RestXmlErrors.wrappedErrorResponseDeserializer(ctx))
+        return SerdeCtx("errReader")
     }
 }
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
index 3db60123682..a3168646a31 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
@@ -6,20 +6,19 @@ package software.amazon.smithy.kotlin.codegen.aws.protocols
 
 import software.amazon.smithy.aws.traits.protocols.Ec2QueryNameTrait
 import software.amazon.smithy.aws.traits.protocols.Ec2QueryTrait
+import software.amazon.smithy.codegen.core.Symbol
 import software.amazon.smithy.kotlin.codegen.aws.protocols.core.AbstractQueryFormUrlSerializerGenerator
 import software.amazon.smithy.kotlin.codegen.aws.protocols.core.QueryHttpBindingProtocolGenerator
 import software.amazon.smithy.kotlin.codegen.aws.protocols.formurl.QuerySerdeFormUrlDescriptorGenerator
 import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
 import software.amazon.smithy.kotlin.codegen.core.RenderingContext
 import software.amazon.smithy.kotlin.codegen.core.RuntimeTypes
-import software.amazon.smithy.kotlin.codegen.model.changeNameSuffix
+import software.amazon.smithy.kotlin.codegen.core.withBlock
+import software.amazon.smithy.kotlin.codegen.model.buildSymbol
 import software.amazon.smithy.kotlin.codegen.model.getTrait
-import software.amazon.smithy.kotlin.codegen.model.hasTrait
-import software.amazon.smithy.kotlin.codegen.model.traits.OperationOutput
 import software.amazon.smithy.kotlin.codegen.rendering.protocol.ProtocolGenerator
 import software.amazon.smithy.kotlin.codegen.rendering.protocol.toRenderingContext
 import software.amazon.smithy.kotlin.codegen.rendering.serde.*
-import software.amazon.smithy.kotlin.codegen.utils.dq
 import software.amazon.smithy.model.shapes.*
 import software.amazon.smithy.model.traits.XmlNameTrait
 
@@ -73,24 +72,6 @@ private class Ec2QuerySerdeFormUrlDescriptorGenerator(
         targetShape.type == ShapeType.LIST
 }
 
-private class Ec2QuerySerdeXmlDescriptorGenerator(
-    ctx: RenderingContext<Shape>,
-    memberShapes: List<MemberShape>? = null,
-) : XmlSerdeDescriptorGenerator(ctx, memberShapes) {
-
-    override fun getObjectDescriptorTraits(): List<SdkFieldDescriptorTrait> {
-        val traits = super.getObjectDescriptorTraits().toMutableList()
-
-        if (objectShape.hasTrait<OperationOutput>()) {
-            traits.removeIf { it.symbol == RuntimeTypes.Serde.SerdeXml.XmlSerialName }
-            val serialName = objectShape.changeNameSuffix("Response" to "Result")
-            traits.add(RuntimeTypes.Serde.SerdeXml.XmlSerialName, serialName.dq())
-        }
-
-        return traits
-    }
-}
-
 private class Ec2QuerySerializerGenerator(
     private val protocolGenerator: Ec2Query,
 ) : AbstractQueryFormUrlSerializerGenerator(protocolGenerator, protocolGenerator.defaultTimestampFormat) {
@@ -104,13 +85,73 @@ private class Ec2QuerySerializerGenerator(
 }
 
 private class Ec2QueryParserGenerator(
-    private val protocolGenerator: Ec2Query,
+    protocolGenerator: Ec2Query,
 ) : XmlParserGenerator(protocolGenerator, protocolGenerator.defaultTimestampFormat) {
-
-    override fun descriptorGenerator(
+    override fun unwrapOperationError(
         ctx: ProtocolGenerator.GenerationContext,
-        shape: Shape,
-        members: List<MemberShape>,
+        serdeCtx: SerdeCtx,
+        errorShape: StructureShape,
         writer: KotlinWriter,
-    ): XmlSerdeDescriptorGenerator = Ec2QuerySerdeXmlDescriptorGenerator(ctx.toRenderingContext(protocolGenerator, shape, writer), members)
+    ): SerdeCtx {
+        val unwrapFn = unwrapErrorResponse(ctx)
+        writer.write("val errReader = #T(${serdeCtx.tagReader})", unwrapFn)
+        return SerdeCtx("errReader")
+    }
+
+    /**
+     * Error deserializer for a wrapped error response
+     *
+     * ```
+     * <Response>
+     *     <Errors>
+     *         <Error>
+     *             <-- DATA -->>
+     *         </Error>
+     *     </Errors>
+     * </Response>
+     * ```
+     *
+     * See https://smithy.io/2.0/aws/protocols/aws-ec2-query-protocol.html#operation-error-serialization
+     */
+    private fun unwrapErrorResponse(ctx: ProtocolGenerator.GenerationContext): Symbol = buildSymbol {
+        name = "unwrapXmlErrorResponse"
+        namespace = ctx.settings.pkg.serde
+        definitionFile = "XmlErrorUtils.kt"
+        renderBy = { writer ->
+            writer.dokka("Handle [wrapped](https://smithy.io/2.0/aws/protocols/aws-ec2-query-protocol.html#operation-error-serialization) error responses")
+            writer.withBlock(
+                "internal fun $name(root: #1T): #1T {",
+                "}",
+                RuntimeTypes.Serde.SerdeXml.TagReader,
+            ) {
+                withBlock(
+                    "if (root.startTag.name.tag != #S) {",
+                    "}",
+                    "Response",
+                ) {
+                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid root, expected <Response>; found `\${root.startTag}`")
+                }
+
+                write("val errorsTag = root.nextTag()")
+                withBlock(
+                    "if (errorsTag == null || errorsTag.startTag.name.tag != #S) {",
+                    "}",
+                    "Errors",
+                ) {
+                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid error, expected <Errors>; found `\${errorsTag?.startTag}`")
+                }
+
+                write("val errTag = errorsTag.nextTag()")
+                withBlock(
+                    "if (errTag == null || errTag.startTag.name.tag != #S) {",
+                    "}",
+                    "Error",
+                ) {
+                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid error, expected <Error>; found `\${errTag?.startTag}`")
+                }
+
+                write("return errTag")
+            }
+        }
+    }
 }
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
index 158fc9c0262..36df309aefd 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
@@ -90,6 +90,7 @@ class RestXmlParserGenerator(
         else -> super.payloadDeserializer(ctx, shape, members)
     }
 
+    // FIXME - reconcile
     private fun explicitBoundStructureDeserializer(
         ctx: ProtocolGenerator.GenerationContext,
         boundMember: MemberShape,
@@ -112,14 +113,113 @@ class RestXmlParserGenerator(
                 addNestedDocumentDeserializers(ctx, targetShape, writer)
                 writer.dokka("Payload deserializer for ${memberSymbol.name} with a different XML name trait (${xmlNameTrait.value})")
                 writer.withBlock("internal fun $name(payload: ByteArray): #T {", "}", memberSymbol) {
-                    write("val deserializer = #T(payload)", RuntimeTypes.Serde.SerdeXml.XmlDeserializer)
+                    writer.write("val root = #T(payload).#T()", RuntimeTypes.Serde.SerdeXml.xmlStreamReader, RuntimeTypes.Serde.SerdeXml.root)
+                    val serdeCtx = SerdeCtx("root")
                     write("val builder = #T.Builder()", memberSymbol)
-                    renderDeserializerBody(ctx, copyWithMemberTraits, targetShape.members().toList(), writer)
+                    renderDeserializerBody(ctx, serdeCtx, copyWithMemberTraits, targetShape.members().toList(), writer)
                     write("return builder.build()")
                 }
             }
         }
     }
+
+    override fun unwrapOperationError(
+        ctx: ProtocolGenerator.GenerationContext,
+        serdeCtx: SerdeCtx,
+        errorShape: StructureShape,
+        writer: KotlinWriter,
+    ): SerdeCtx {
+        val unwrapFn = when (ctx.service.getTrait<RestXmlTrait>()?.isNoErrorWrapping == true) {
+            true -> RestXmlErrors.unwrappedErrorResponseDeserializer(ctx)
+            false -> RestXmlErrors.wrappedErrorResponseDeserializer(ctx)
+        }
+        writer.write("val errReader = #T(${serdeCtx.tagReader})", unwrapFn)
+        return SerdeCtx("errReader")
+    }
+}
+
+object RestXmlErrors {
+
+    /**
+     * Error deserializer for a wrapped error response
+     *
+     * ```
+     * <ErrorResponse>
+     *     <Error>
+     *         <-- DATA -->>
+     *     </Error>
+     * </ErrorResponse>
+     * ```
+     *
+     * See https://smithy.io/2.0/aws/protocols/aws-restxml-protocol.html#error-response-serialization
+     */
+    fun wrappedErrorResponseDeserializer(ctx: ProtocolGenerator.GenerationContext): Symbol = buildSymbol {
+        name = "unwrapWrappedXmlErrorResponse"
+        namespace = ctx.settings.pkg.serde
+        definitionFile = "XmlErrorUtils.kt"
+        renderBy = { writer ->
+            writer.dokka("Handle [wrapped](https://smithy.io/2.0/aws/protocols/aws-restxml-protocol.html#error-response-serialization) error responses")
+            writer.withBlock(
+                "internal fun $name(root: #1T): #1T {",
+                "}",
+                RuntimeTypes.Serde.SerdeXml.TagReader,
+            ) {
+                withBlock(
+                    "if (root.startTag.name.tag != #S) {",
+                    "}",
+                    "ErrorResponse",
+                ) {
+                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid root, expected <ErrorResponse>; found `\${root.startTag}`")
+                }
+
+                write("val errTag = root.nextTag()")
+                withBlock(
+                    "if (errTag == null || errTag.startTag.name.tag != #S) {",
+                    "}",
+                    "Error",
+                ) {
+                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid error, expected <Error>; found `\${errTag?.startTag}`")
+                }
+
+                write("return errTag")
+            }
+        }
+    }
+
+    /**
+     * Error deserializer for an unwrapped error response
+     *
+     * ```
+     * <Error>
+     *    <-- DATA -->>
+     * </Error>
+     * ```
+     *
+     * See https://smithy.io/2.0/aws/protocols/aws-restxml-protocol.html#error-response-serialization
+     */
+    fun unwrappedErrorResponseDeserializer(ctx: ProtocolGenerator.GenerationContext): Symbol = buildSymbol {
+        name = "unwrapXmlErrorResponse"
+        namespace = ctx.settings.pkg.serde
+        definitionFile = "XmlErrorUtils.kt"
+        renderBy = { writer ->
+            writer.dokka("Handle [unwrapped](https://smithy.io/2.0/aws/protocols/aws-restxml-protocol.html#error-response-serialization) error responses (restXml.noErrorWrapping == true)")
+            writer.withBlock(
+                "internal fun $name(root: #1T): #1T {",
+                "}",
+                RuntimeTypes.Serde.SerdeXml.TagReader,
+            ) {
+                withBlock(
+                    "if (root.startTag.name.tag != #S) {",
+                    "}",
+                    "Error",
+                ) {
+                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid error, expected <Error>; found `\${errTag?.startTag}`")
+                }
+
+                write("return root")
+            }
+        }
+    }
 }
 
 class RestXmlSerializerGenerator(
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 063cd76d368..88a30d55c61 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -9,8 +9,8 @@ coroutines-version = "1.7.3"
 atomicfu-version = "0.23.1"
 
 # smithy-kotlin codegen and runtime are versioned separately
-smithy-kotlin-runtime-version = "1.0.15"
-smithy-kotlin-codegen-version = "0.30.16"
+smithy-kotlin-runtime-version = "1.0.16-SNAPSHOT"
+smithy-kotlin-codegen-version = "0.30.17-SNAPSHOT"
 
 # codegen
 smithy-version = "1.42.0"

From 614d0a64298c5e650fd260083116cb5490355cce Mon Sep 17 00:00:00 2001
From: Aaron J Todd <todaaron@amazon.com>
Date: Fri, 23 Feb 2024 14:54:00 -0500
Subject: [PATCH 02/11] fix error deserializer

---
 .../amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt      | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
index 36df309aefd..7b8190a4fb6 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
@@ -213,7 +213,7 @@ object RestXmlErrors {
                     "}",
                     "Error",
                 ) {
-                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid error, expected <Error>; found `\${errTag?.startTag}`")
+                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid error, expected <Error>; found `\${root.startTag}`")
                 }
 
                 write("return root")
@@ -245,6 +245,7 @@ class RestXmlSerializerGenerator(
         else -> super.payloadSerializer(ctx, shape, members)
     }
 
+    // FIXME
     private fun explicitBoundStructureSerializer(
         ctx: ProtocolGenerator.GenerationContext,
         boundMember: MemberShape,

From 406d43f34969b7f2e4ba67b82de5a14c55428aaf Mon Sep 17 00:00:00 2001
From: Aaron J Todd <todaaron@amazon.com>
Date: Sat, 24 Feb 2024 21:15:51 -0500
Subject: [PATCH 03/11] fix custom deserializers

---
 .../ChangeResourceRecordSetsUnmarshalling.kt  | 62 +++++++++----------
 ...angeResourceRecordSetsUnmarshallingTest.kt |  2 +-
 .../services/s3/internal/S3ErrorMetadata.kt   | 36 ++++-------
 3 files changed, 43 insertions(+), 57 deletions(-)

diff --git a/services/route53/common/src/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshalling.kt b/services/route53/common/src/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshalling.kt
index 5b5af0d4748..e75a0e7dd6f 100644
--- a/services/route53/common/src/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshalling.kt
+++ b/services/route53/common/src/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshalling.kt
@@ -6,50 +6,48 @@ package aws.sdk.kotlin.services.route53.internal
 
 import aws.sdk.kotlin.services.route53.model.InvalidChangeBatch
 import aws.smithy.kotlin.runtime.awsprotocol.ErrorDetails
-import aws.smithy.kotlin.runtime.serde.*
+import aws.smithy.kotlin.runtime.awsprotocol.xml.parseRestXmlErrorResponse
 import aws.smithy.kotlin.runtime.serde.xml.*
 
 internal fun parseRestXmlInvalidChangeBatchResponse(payload: ByteArray): InvalidChangeBatchErrorResponse? =
     deserializeInvalidChangeBatchError(InvalidChangeBatch.Builder(), payload)
 
 internal fun deserializeInvalidChangeBatchError(builder: InvalidChangeBatch.Builder, payload: ByteArray): InvalidChangeBatchErrorResponse? {
-    val deserializer = XmlDeserializer(payload)
-    val MESSAGE_DESCRIPTOR = SdkFieldDescriptor(SerialKind.String, XmlSerialName("message"), XmlAliasName("Message"))
-    val MESSAGES_DESCRIPTOR = SdkFieldDescriptor(SerialKind.List, XmlSerialName("messages"), XmlAliasName("Messages"), XmlCollectionName("Message"))
-    val REQUESTID_DESCRIPTOR = SdkFieldDescriptor(SerialKind.String, XmlSerialName("RequestId"))
-    val OBJ_DESCRIPTOR = SdkObjectDescriptor.build {
-        trait(XmlSerialName("InvalidChangeBatch"))
-        trait(XmlNamespace("https://route53.amazonaws.com/doc/2013-04-01/"))
-        field(MESSAGE_DESCRIPTOR)
-        field(MESSAGES_DESCRIPTOR)
-        field(REQUESTID_DESCRIPTOR)
+    val root = xmlStreamReader(payload).root()
+    if (root.startTag.name.tag == "ErrorResponse") {
+        val errDetails = parseRestXmlErrorResponse(payload)
+        builder.message = errDetails.message
+        return InvalidChangeBatchErrorResponse(errDetails, builder.build())
     }
+
     var requestId: String? = null
 
-    return try {
-        deserializer.deserializeStruct(OBJ_DESCRIPTOR) {
-            loop@while (true) {
-                when (findNextFieldIndex()) {
-                    MESSAGE_DESCRIPTOR.index -> builder.message = deserializeString()
-                    REQUESTID_DESCRIPTOR.index -> requestId = deserializeString()
-                    MESSAGES_DESCRIPTOR.index ->
-                        builder.messages = deserializer.deserializeList(MESSAGES_DESCRIPTOR) {
-                            val col0 = mutableListOf<String>()
-                            while (hasNextElement()) {
-                                val el0 = if (nextHasValue()) { deserializeString() } else { deserializeNull(); continue }
-                                col0.add(el0)
-                            }
-                            col0
-                        }
-                    null -> break@loop
-                    else -> skipValue()
-                }
+    loop@while (true) {
+        val curr = root.nextTag() ?: break@loop
+        when (curr.startTag.name.tag) {
+            "Message", "message" -> builder.message = curr.data()
+            "Messages", "messages" -> builder.messages = deserializeMessages(curr)
+            "RequestId" -> requestId = curr.data()
+        }
+        curr.drop()
+    }
+
+    return InvalidChangeBatchErrorResponse(ErrorDetails("InvalidChangeBatch", builder.message, requestId), builder.build())
+}
+
+private fun deserializeMessages(root: TagReader): List<String> {
+    val result = mutableListOf<String>()
+    loop@while (true) {
+        val curr = root.nextTag() ?: break@loop
+        when (curr.startTag.name.tag) {
+            "Message" -> {
+                val el = curr.tryData().getOrNull() ?: continue@loop
+                result.add(el)
             }
         }
-        InvalidChangeBatchErrorResponse(ErrorDetails("InvalidChangeBatch", builder.message, requestId), builder.build())
-    } catch (e: DeserializationException) {
-        null // return so an appropriate exception type can be instantiated above here.
     }
+
+    return result
 }
 
 internal data class InvalidChangeBatchErrorResponse(
diff --git a/services/route53/common/test/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshallingTest.kt b/services/route53/common/test/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshallingTest.kt
index b6bd664a3d3..de99fd13630 100644
--- a/services/route53/common/test/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshallingTest.kt
+++ b/services/route53/common/test/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshallingTest.kt
@@ -32,7 +32,7 @@ class ChangeResourceRecordSetsUnmarshallingTest {
             </InvalidChangeBatch>
         """.trimIndent()
 
-        val response: HttpResponse = HttpResponse(
+        val response = HttpResponse(
             HttpStatusCode.BadRequest,
             Headers.Empty,
             HttpBody.fromBytes(bodyText.encodeToByteArray()),
diff --git a/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/S3ErrorMetadata.kt b/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/S3ErrorMetadata.kt
index 68ad4342281..4bec30f39ac 100644
--- a/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/S3ErrorMetadata.kt
+++ b/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/S3ErrorMetadata.kt
@@ -14,8 +14,9 @@ import aws.smithy.kotlin.runtime.awsprotocol.setAseErrorMetadata
 import aws.smithy.kotlin.runtime.collections.setIfValueNotNull
 import aws.smithy.kotlin.runtime.http.response.HttpResponse
 import aws.smithy.kotlin.runtime.serde.*
-import aws.smithy.kotlin.runtime.serde.xml.XmlDeserializer
-import aws.smithy.kotlin.runtime.serde.xml.XmlSerialName
+import aws.smithy.kotlin.runtime.serde.xml.data
+import aws.smithy.kotlin.runtime.serde.xml.root
+import aws.smithy.kotlin.runtime.serde.xml.xmlStreamReader
 
 /**
  * Default header name identifying secondary request ID
@@ -45,35 +46,22 @@ internal fun setS3ErrorMetadata(exception: Any, response: HttpResponse, errorDet
 }
 
 internal fun parseS3ErrorResponse(payload: ByteArray): S3ErrorDetails {
-    val MESSAGE_DESCRIPTOR = SdkFieldDescriptor(SerialKind.String, XmlSerialName("Message"))
-    val CODE_DESCRIPTOR = SdkFieldDescriptor(SerialKind.String, XmlSerialName("Code"))
-    val REQUESTID_DESCRIPTOR = SdkFieldDescriptor(SerialKind.String, XmlSerialName("RequestId"))
-    val HOSTID_DESCRIPTOR = SdkFieldDescriptor(SerialKind.String, XmlSerialName("HostId"))
-    val OBJ_DESCRIPTOR = SdkObjectDescriptor.build {
-        trait(XmlSerialName("Error"))
-        field(MESSAGE_DESCRIPTOR)
-        field(CODE_DESCRIPTOR)
-        field(REQUESTID_DESCRIPTOR)
-        field(HOSTID_DESCRIPTOR)
-    }
+    val root = xmlStreamReader(payload).root()
 
     var message: String? = null
     var code: String? = null
     var requestId: String? = null
     var requestId2: String? = null
 
-    val deserializer = XmlDeserializer(payload, true)
-    deserializer.deserializeStruct(OBJ_DESCRIPTOR) {
-        loop@ while (true) {
-            when (findNextFieldIndex()) {
-                MESSAGE_DESCRIPTOR.index -> message = deserializeString()
-                CODE_DESCRIPTOR.index -> code = deserializeString()
-                REQUESTID_DESCRIPTOR.index -> requestId = deserializeString()
-                HOSTID_DESCRIPTOR.index -> requestId2 = deserializeString()
-                null -> break@loop
-                else -> skipValue()
-            }
+    loop@ while (true) {
+        val curr = root.nextTag() ?: break@loop
+        when (curr.startTag.name.tag) {
+            "Code" -> code = curr.data()
+            "Message", "message" -> message = curr.data()
+            "RequestId" -> requestId = curr.data()
+            "HostId" -> requestId2 = curr.data()
         }
+        curr.drop()
     }
 
     return S3ErrorDetails(code, message, requestId, requestId2)

From 437846dc18b7fa90fd73026d16b99babbb37c636 Mon Sep 17 00:00:00 2001
From: Aaron J Todd <todaaron@amazon.com>
Date: Sat, 24 Feb 2024 21:24:43 -0500
Subject: [PATCH 04/11] remove unused

---
 .../kotlin/codegen/aws/protocols/AwsQuery.kt       |  2 +-
 .../kotlin/codegen/aws/protocols/Ec2Query.kt       |  2 +-
 .../smithy/kotlin/codegen/aws/protocols/RestXml.kt | 14 +++-----------
 3 files changed, 5 insertions(+), 13 deletions(-)

diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
index 4ed06644ca2..5606696d7a9 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
@@ -80,7 +80,7 @@ private class AwsQuerySerializerGenerator(
 
 private class AwsQueryXmlParserGenerator(
     protocolGenerator: AwsQuery,
-) : XmlParserGenerator(protocolGenerator, protocolGenerator.defaultTimestampFormat) {
+) : XmlParserGenerator(protocolGenerator.defaultTimestampFormat) {
 
     /**
      * Unwraps the response body as specified by
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
index a3168646a31..aa7dab7d932 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
@@ -86,7 +86,7 @@ private class Ec2QuerySerializerGenerator(
 
 private class Ec2QueryParserGenerator(
     protocolGenerator: Ec2Query,
-) : XmlParserGenerator(protocolGenerator, protocolGenerator.defaultTimestampFormat) {
+) : XmlParserGenerator(protocolGenerator.defaultTimestampFormat) {
     override fun unwrapOperationError(
         ctx: ProtocolGenerator.GenerationContext,
         serdeCtx: SerdeCtx,
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
index 7b8190a4fb6..5db443c5cbd 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
@@ -52,7 +52,7 @@ open class RestXml : AwsHttpBindingProtocolGenerator() {
     }
 
     override fun structuredDataParser(ctx: ProtocolGenerator.GenerationContext): StructuredDataParserGenerator =
-        RestXmlParserGenerator(this, defaultTimestampFormat)
+        RestXmlParserGenerator(this)
 
     override fun structuredDataSerializer(ctx: ProtocolGenerator.GenerationContext): StructuredDataSerializerGenerator =
         RestXmlSerializerGenerator(this, defaultTimestampFormat)
@@ -68,16 +68,8 @@ open class RestXml : AwsHttpBindingProtocolGenerator() {
 }
 
 class RestXmlParserGenerator(
-    private val protocolGenerator: RestXml,
-    defaultTimestampFormat: TimestampFormatTrait.Format,
-) : XmlParserGenerator(protocolGenerator, defaultTimestampFormat) {
-
-    override fun descriptorGenerator(
-        ctx: ProtocolGenerator.GenerationContext,
-        shape: Shape,
-        members: List<MemberShape>,
-        writer: KotlinWriter,
-    ): XmlSerdeDescriptorGenerator = RestXmlSerdeDescriptorGenerator(ctx.toRenderingContext(protocolGenerator, shape, writer), members)
+    protocolGenerator: RestXml,
+) : XmlParserGenerator(protocolGenerator.defaultTimestampFormat) {
 
     override fun payloadDeserializer(
         ctx: ProtocolGenerator.GenerationContext,

From 5e39c2f1c05b71e7117e7c90be0f4d44458d4476 Mon Sep 17 00:00:00 2001
From: Aaron J Todd <todaaron@amazon.com>
Date: Sat, 24 Feb 2024 22:31:45 -0500
Subject: [PATCH 05/11] upstream cleanup

---
 .../kotlin/codegen/aws/protocols/AwsQuery.kt       |  8 ++++----
 .../kotlin/codegen/aws/protocols/Ec2Query.kt       | 12 ++++++------
 .../smithy/kotlin/codegen/aws/protocols/RestXml.kt | 14 +++++++-------
 .../ChangeResourceRecordSetsUnmarshalling.kt       |  8 ++++----
 .../kotlin/services/s3/internal/S3ErrorMetadata.kt |  9 +++------
 5 files changed, 24 insertions(+), 27 deletions(-)

diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
index 5606696d7a9..620a1eae03e 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
@@ -118,18 +118,18 @@ private class AwsQueryXmlParserGenerator(
                     write("val responseWrapperName = \"\${operationName}Response\"")
                     write("val resultWrapperName = \"\${operationName}Result\"")
                     withBlock(
-                        "if (root.startTag.name.tag != responseWrapperName) {",
+                        "if (root.tag.name.tag != responseWrapperName) {",
                         "}",
                     ) {
-                        write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid root, expected \$responseWrapperName; found `\${root.startTag}`")
+                        write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid root, expected \$responseWrapperName; found `\${root.tag}`")
                     }
 
                     write("val resultTag = ${serdeCtx.tagReader}.nextTag()")
                     withBlock(
-                        "if (resultTag == null || resultTag.startTag.name.tag != resultWrapperName) {",
+                        "if (resultTag == null || resultTag.tag.name.tag != resultWrapperName) {",
                         "}",
                     ) {
-                        write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid result, expected \$resultWrapperName; found `\${resultTag?.startTag}`")
+                        write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid result, expected \$resultWrapperName; found `\${resultTag?.tag}`")
                     }
 
                     write("return resultTag")
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
index aa7dab7d932..9bb0e5a45c1 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
@@ -125,29 +125,29 @@ private class Ec2QueryParserGenerator(
                 RuntimeTypes.Serde.SerdeXml.TagReader,
             ) {
                 withBlock(
-                    "if (root.startTag.name.tag != #S) {",
+                    "if (root.tag.name.tag != #S) {",
                     "}",
                     "Response",
                 ) {
-                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid root, expected <Response>; found `\${root.startTag}`")
+                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid root, expected <Response>; found `\${root.tag}`")
                 }
 
                 write("val errorsTag = root.nextTag()")
                 withBlock(
-                    "if (errorsTag == null || errorsTag.startTag.name.tag != #S) {",
+                    "if (errorsTag == null || errorsTag.tag.name.tag != #S) {",
                     "}",
                     "Errors",
                 ) {
-                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid error, expected <Errors>; found `\${errorsTag?.startTag}`")
+                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid error, expected <Errors>; found `\${errorsTag?.tag}`")
                 }
 
                 write("val errTag = errorsTag.nextTag()")
                 withBlock(
-                    "if (errTag == null || errTag.startTag.name.tag != #S) {",
+                    "if (errTag == null || errTag.tag.name.tag != #S) {",
                     "}",
                     "Error",
                 ) {
-                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid error, expected <Error>; found `\${errTag?.startTag}`")
+                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid error, expected <Error>; found `\${errTag?.tag}`")
                 }
 
                 write("return errTag")
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
index 5db443c5cbd..96397d75622 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
@@ -105,7 +105,7 @@ class RestXmlParserGenerator(
                 addNestedDocumentDeserializers(ctx, targetShape, writer)
                 writer.dokka("Payload deserializer for ${memberSymbol.name} with a different XML name trait (${xmlNameTrait.value})")
                 writer.withBlock("internal fun $name(payload: ByteArray): #T {", "}", memberSymbol) {
-                    writer.write("val root = #T(payload).#T()", RuntimeTypes.Serde.SerdeXml.xmlStreamReader, RuntimeTypes.Serde.SerdeXml.root)
+                    writer.write("val root = #T(payload)", RuntimeTypes.Serde.SerdeXml.xmlTagReader)
                     val serdeCtx = SerdeCtx("root")
                     write("val builder = #T.Builder()", memberSymbol)
                     renderDeserializerBody(ctx, serdeCtx, copyWithMemberTraits, targetShape.members().toList(), writer)
@@ -157,20 +157,20 @@ object RestXmlErrors {
                 RuntimeTypes.Serde.SerdeXml.TagReader,
             ) {
                 withBlock(
-                    "if (root.startTag.name.tag != #S) {",
+                    "if (root.tag.name.tag != #S) {",
                     "}",
                     "ErrorResponse",
                 ) {
-                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid root, expected <ErrorResponse>; found `\${root.startTag}`")
+                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid root, expected <ErrorResponse>; found `\${root.tag}`")
                 }
 
                 write("val errTag = root.nextTag()")
                 withBlock(
-                    "if (errTag == null || errTag.startTag.name.tag != #S) {",
+                    "if (errTag == null || errTag.tag.name.tag != #S) {",
                     "}",
                     "Error",
                 ) {
-                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid error, expected <Error>; found `\${errTag?.startTag}`")
+                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid error, expected <Error>; found `\${errTag?.tag}`")
                 }
 
                 write("return errTag")
@@ -201,11 +201,11 @@ object RestXmlErrors {
                 RuntimeTypes.Serde.SerdeXml.TagReader,
             ) {
                 withBlock(
-                    "if (root.startTag.name.tag != #S) {",
+                    "if (root.tag.name.tag != #S) {",
                     "}",
                     "Error",
                 ) {
-                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid error, expected <Error>; found `\${root.startTag}`")
+                    write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid error, expected <Error>; found `\${root.tag}`")
                 }
 
                 write("return root")
diff --git a/services/route53/common/src/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshalling.kt b/services/route53/common/src/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshalling.kt
index e75a0e7dd6f..32d929445c9 100644
--- a/services/route53/common/src/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshalling.kt
+++ b/services/route53/common/src/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshalling.kt
@@ -14,7 +14,7 @@ internal fun parseRestXmlInvalidChangeBatchResponse(payload: ByteArray): Invalid
 
 internal fun deserializeInvalidChangeBatchError(builder: InvalidChangeBatch.Builder, payload: ByteArray): InvalidChangeBatchErrorResponse? {
     val root = xmlStreamReader(payload).root()
-    if (root.startTag.name.tag == "ErrorResponse") {
+    if (root.tag.name.tag == "ErrorResponse") {
         val errDetails = parseRestXmlErrorResponse(payload)
         builder.message = errDetails.message
         return InvalidChangeBatchErrorResponse(errDetails, builder.build())
@@ -24,7 +24,7 @@ internal fun deserializeInvalidChangeBatchError(builder: InvalidChangeBatch.Buil
 
     loop@while (true) {
         val curr = root.nextTag() ?: break@loop
-        when (curr.startTag.name.tag) {
+        when (curr.tag.name.tag) {
             "Message", "message" -> builder.message = curr.data()
             "Messages", "messages" -> builder.messages = deserializeMessages(curr)
             "RequestId" -> requestId = curr.data()
@@ -35,11 +35,11 @@ internal fun deserializeInvalidChangeBatchError(builder: InvalidChangeBatch.Buil
     return InvalidChangeBatchErrorResponse(ErrorDetails("InvalidChangeBatch", builder.message, requestId), builder.build())
 }
 
-private fun deserializeMessages(root: TagReader): List<String> {
+private fun deserializeMessages(root: XmlTagReader): List<String> {
     val result = mutableListOf<String>()
     loop@while (true) {
         val curr = root.nextTag() ?: break@loop
-        when (curr.startTag.name.tag) {
+        when (curr.tag.name.tag) {
             "Message" -> {
                 val el = curr.tryData().getOrNull() ?: continue@loop
                 result.add(el)
diff --git a/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/S3ErrorMetadata.kt b/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/S3ErrorMetadata.kt
index 4bec30f39ac..2a2db6fad87 100644
--- a/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/S3ErrorMetadata.kt
+++ b/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/S3ErrorMetadata.kt
@@ -5,7 +5,6 @@
 package aws.sdk.kotlin.services.s3.internal
 
 import aws.sdk.kotlin.runtime.AwsServiceException
-import aws.sdk.kotlin.runtime.http.*
 import aws.sdk.kotlin.services.s3.model.S3ErrorMetadata
 import aws.sdk.kotlin.services.s3.model.S3Exception
 import aws.smithy.kotlin.runtime.ServiceErrorMetadata
@@ -13,10 +12,8 @@ import aws.smithy.kotlin.runtime.awsprotocol.AwsErrorDetails
 import aws.smithy.kotlin.runtime.awsprotocol.setAseErrorMetadata
 import aws.smithy.kotlin.runtime.collections.setIfValueNotNull
 import aws.smithy.kotlin.runtime.http.response.HttpResponse
-import aws.smithy.kotlin.runtime.serde.*
 import aws.smithy.kotlin.runtime.serde.xml.data
-import aws.smithy.kotlin.runtime.serde.xml.root
-import aws.smithy.kotlin.runtime.serde.xml.xmlStreamReader
+import aws.smithy.kotlin.runtime.serde.xml.xmlTagReader
 
 /**
  * Default header name identifying secondary request ID
@@ -46,7 +43,7 @@ internal fun setS3ErrorMetadata(exception: Any, response: HttpResponse, errorDet
 }
 
 internal fun parseS3ErrorResponse(payload: ByteArray): S3ErrorDetails {
-    val root = xmlStreamReader(payload).root()
+    val root = xmlTagReader(payload)
 
     var message: String? = null
     var code: String? = null
@@ -55,7 +52,7 @@ internal fun parseS3ErrorResponse(payload: ByteArray): S3ErrorDetails {
 
     loop@ while (true) {
         val curr = root.nextTag() ?: break@loop
-        when (curr.startTag.name.tag) {
+        when (curr.tag.name.tag) {
             "Code" -> code = curr.data()
             "Message", "message" -> message = curr.data()
             "RequestId" -> requestId = curr.data()

From 04e0a44c7a9eb1ae0e59b2616fd15ad0fd4e3ca1 Mon Sep 17 00:00:00 2001
From: Aaron J Todd <todaaron@amazon.com>
Date: Sat, 24 Feb 2024 23:15:06 -0500
Subject: [PATCH 06/11] more upstream cleanup

---
 .../smithy/kotlin/codegen/aws/protocols/AwsQuery.kt  |  6 +++---
 .../smithy/kotlin/codegen/aws/protocols/Ec2Query.kt  |  8 ++++----
 .../smithy/kotlin/codegen/aws/protocols/RestXml.kt   | 12 ++++++------
 .../ChangeResourceRecordSetsUnmarshalling.kt         |  8 ++++----
 .../s3/internal/Handle200ErrorsInterceptor.kt        |  2 +-
 .../kotlin/services/s3/internal/S3ErrorMetadata.kt   |  2 +-
 6 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
index 620a1eae03e..841a04c937a 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
@@ -112,13 +112,13 @@ private class AwsQueryXmlParserGenerator(
                 writer.withBlock(
                     "internal fun $name(root: #1T, operationName: #2T): #1T {",
                     "}",
-                    RuntimeTypes.Serde.SerdeXml.TagReader,
+                    RuntimeTypes.Serde.SerdeXml.XmlTagReader,
                     KotlinTypes.String,
                 ) {
                     write("val responseWrapperName = \"\${operationName}Response\"")
                     write("val resultWrapperName = \"\${operationName}Result\"")
                     withBlock(
-                        "if (root.tag.name.tag != responseWrapperName) {",
+                        "if (root.tag.name != responseWrapperName) {",
                         "}",
                     ) {
                         write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid root, expected \$responseWrapperName; found `\${root.tag}`")
@@ -126,7 +126,7 @@ private class AwsQueryXmlParserGenerator(
 
                     write("val resultTag = ${serdeCtx.tagReader}.nextTag()")
                     withBlock(
-                        "if (resultTag == null || resultTag.tag.name.tag != resultWrapperName) {",
+                        "if (resultTag == null || resultTag.tag.name != resultWrapperName) {",
                         "}",
                     ) {
                         write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid result, expected \$resultWrapperName; found `\${resultTag?.tag}`")
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
index 9bb0e5a45c1..ec17ca24423 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
@@ -122,10 +122,10 @@ private class Ec2QueryParserGenerator(
             writer.withBlock(
                 "internal fun $name(root: #1T): #1T {",
                 "}",
-                RuntimeTypes.Serde.SerdeXml.TagReader,
+                RuntimeTypes.Serde.SerdeXml.XmlTagReader,
             ) {
                 withBlock(
-                    "if (root.tag.name.tag != #S) {",
+                    "if (root.tag.name != #S) {",
                     "}",
                     "Response",
                 ) {
@@ -134,7 +134,7 @@ private class Ec2QueryParserGenerator(
 
                 write("val errorsTag = root.nextTag()")
                 withBlock(
-                    "if (errorsTag == null || errorsTag.tag.name.tag != #S) {",
+                    "if (errorsTag == null || errorsTag.tag.name != #S) {",
                     "}",
                     "Errors",
                 ) {
@@ -143,7 +143,7 @@ private class Ec2QueryParserGenerator(
 
                 write("val errTag = errorsTag.nextTag()")
                 withBlock(
-                    "if (errTag == null || errTag.tag.name.tag != #S) {",
+                    "if (errTag == null || errTag.tag.name != #S) {",
                     "}",
                     "Error",
                 ) {
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
index 96397d75622..03fc1a57419 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
@@ -105,7 +105,7 @@ class RestXmlParserGenerator(
                 addNestedDocumentDeserializers(ctx, targetShape, writer)
                 writer.dokka("Payload deserializer for ${memberSymbol.name} with a different XML name trait (${xmlNameTrait.value})")
                 writer.withBlock("internal fun $name(payload: ByteArray): #T {", "}", memberSymbol) {
-                    writer.write("val root = #T(payload)", RuntimeTypes.Serde.SerdeXml.xmlTagReader)
+                    writer.write("val root = #T(payload)", RuntimeTypes.Serde.SerdeXml.xmlRootTagReader)
                     val serdeCtx = SerdeCtx("root")
                     write("val builder = #T.Builder()", memberSymbol)
                     renderDeserializerBody(ctx, serdeCtx, copyWithMemberTraits, targetShape.members().toList(), writer)
@@ -154,10 +154,10 @@ object RestXmlErrors {
             writer.withBlock(
                 "internal fun $name(root: #1T): #1T {",
                 "}",
-                RuntimeTypes.Serde.SerdeXml.TagReader,
+                RuntimeTypes.Serde.SerdeXml.XmlTagReader,
             ) {
                 withBlock(
-                    "if (root.tag.name.tag != #S) {",
+                    "if (root.tag.name != #S) {",
                     "}",
                     "ErrorResponse",
                 ) {
@@ -166,7 +166,7 @@ object RestXmlErrors {
 
                 write("val errTag = root.nextTag()")
                 withBlock(
-                    "if (errTag == null || errTag.tag.name.tag != #S) {",
+                    "if (errTag == null || errTag.tag.name != #S) {",
                     "}",
                     "Error",
                 ) {
@@ -198,10 +198,10 @@ object RestXmlErrors {
             writer.withBlock(
                 "internal fun $name(root: #1T): #1T {",
                 "}",
-                RuntimeTypes.Serde.SerdeXml.TagReader,
+                RuntimeTypes.Serde.SerdeXml.XmlTagReader,
             ) {
                 withBlock(
-                    "if (root.tag.name.tag != #S) {",
+                    "if (root.tag.name != #S) {",
                     "}",
                     "Error",
                 ) {
diff --git a/services/route53/common/src/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshalling.kt b/services/route53/common/src/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshalling.kt
index 32d929445c9..4d240e353e9 100644
--- a/services/route53/common/src/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshalling.kt
+++ b/services/route53/common/src/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshalling.kt
@@ -13,8 +13,8 @@ internal fun parseRestXmlInvalidChangeBatchResponse(payload: ByteArray): Invalid
     deserializeInvalidChangeBatchError(InvalidChangeBatch.Builder(), payload)
 
 internal fun deserializeInvalidChangeBatchError(builder: InvalidChangeBatch.Builder, payload: ByteArray): InvalidChangeBatchErrorResponse? {
-    val root = xmlStreamReader(payload).root()
-    if (root.tag.name.tag == "ErrorResponse") {
+    val root = xmlTagReader(payload)
+    if (root.tag.name == "ErrorResponse") {
         val errDetails = parseRestXmlErrorResponse(payload)
         builder.message = errDetails.message
         return InvalidChangeBatchErrorResponse(errDetails, builder.build())
@@ -24,7 +24,7 @@ internal fun deserializeInvalidChangeBatchError(builder: InvalidChangeBatch.Buil
 
     loop@while (true) {
         val curr = root.nextTag() ?: break@loop
-        when (curr.tag.name.tag) {
+        when (curr.tag.name) {
             "Message", "message" -> builder.message = curr.data()
             "Messages", "messages" -> builder.messages = deserializeMessages(curr)
             "RequestId" -> requestId = curr.data()
@@ -39,7 +39,7 @@ private fun deserializeMessages(root: XmlTagReader): List<String> {
     val result = mutableListOf<String>()
     loop@while (true) {
         val curr = root.nextTag() ?: break@loop
-        when (curr.tag.name.tag) {
+        when (curr.tag.name) {
             "Message" -> {
                 val el = curr.tryData().getOrNull() ?: continue@loop
                 result.add(el)
diff --git a/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/Handle200ErrorsInterceptor.kt b/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/Handle200ErrorsInterceptor.kt
index c5fe16baeda..aafdf1718e5 100644
--- a/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/Handle200ErrorsInterceptor.kt
+++ b/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/Handle200ErrorsInterceptor.kt
@@ -32,7 +32,7 @@ internal object Handle200ErrorsInterceptor : HttpInterceptor {
         // according to the knowledge center article above we should treat these as 5xx,
         // our retry policy will handle standard error codes like `SlowDown`
         val statusCode = HttpStatusCode.InternalServerError
-            .takeIf { token?.name?.local == "Error" }
+            .takeIf { token?.qualifiedName?.local == "Error" }
             ?: response.status
         return response.copy(status = statusCode, body = HttpBody.fromBytes(payload))
     }
diff --git a/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/S3ErrorMetadata.kt b/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/S3ErrorMetadata.kt
index 2a2db6fad87..6f5cb7fef85 100644
--- a/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/S3ErrorMetadata.kt
+++ b/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/S3ErrorMetadata.kt
@@ -52,7 +52,7 @@ internal fun parseS3ErrorResponse(payload: ByteArray): S3ErrorDetails {
 
     loop@ while (true) {
         val curr = root.nextTag() ?: break@loop
-        when (curr.tag.name.tag) {
+        when (curr.tag.name) {
             "Code" -> code = curr.data()
             "Message", "message" -> message = curr.data()
             "RequestId" -> requestId = curr.data()

From 79d42ba59bcd8b53f036103705305a9242b54ce9 Mon Sep 17 00:00:00 2001
From: Aaron J Todd <todaaron@amazon.com>
Date: Mon, 26 Feb 2024 08:20:35 -0500
Subject: [PATCH 07/11] changelog

---
 .changes/119ee420-38a5-4974-922e-29cb11de02d0.json | 8 ++++++++
 1 file changed, 8 insertions(+)
 create mode 100644 .changes/119ee420-38a5-4974-922e-29cb11de02d0.json

diff --git a/.changes/119ee420-38a5-4974-922e-29cb11de02d0.json b/.changes/119ee420-38a5-4974-922e-29cb11de02d0.json
new file mode 100644
index 00000000000..6b02874fee1
--- /dev/null
+++ b/.changes/119ee420-38a5-4974-922e-29cb11de02d0.json
@@ -0,0 +1,8 @@
+{
+    "id": "119ee420-38a5-4974-922e-29cb11de02d0",
+    "type": "bugfix",
+    "description": "Refactor XML deserialization to handle flat collections",
+    "issues": [
+        "awslabs/aws-sdk-kotlin#1220"
+    ]
+}
\ No newline at end of file

From 3d96773d402355892d6fb9253d5947567287dbe6 Mon Sep 17 00:00:00 2001
From: Aaron J Todd <todaaron@amazon.com>
Date: Tue, 27 Feb 2024 12:33:46 -0500
Subject: [PATCH 08/11] upstream changes

---
 .../kotlin/codegen/aws/protocols/AwsQuery.kt  |  4 +--
 .../kotlin/codegen/aws/protocols/Ec2Query.kt  |  6 ++--
 .../kotlin/codegen/aws/protocols/RestXml.kt   |  6 ++--
 .../ChangeResourceRecordSetsUnmarshalling.kt  | 11 ++-----
 ...angeResourceRecordSetsUnmarshallingTest.kt | 31 -------------------
 .../s3/internal/Handle200ErrorsInterceptor.kt |  2 +-
 .../services/s3/internal/S3ErrorMetadata.kt   |  2 +-
 7 files changed, 12 insertions(+), 50 deletions(-)

diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
index 841a04c937a..027e9050f30 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
@@ -118,7 +118,7 @@ private class AwsQueryXmlParserGenerator(
                     write("val responseWrapperName = \"\${operationName}Response\"")
                     write("val resultWrapperName = \"\${operationName}Result\"")
                     withBlock(
-                        "if (root.tag.name != responseWrapperName) {",
+                        "if (root.tagName != responseWrapperName) {",
                         "}",
                     ) {
                         write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid root, expected \$responseWrapperName; found `\${root.tag}`")
@@ -126,7 +126,7 @@ private class AwsQueryXmlParserGenerator(
 
                     write("val resultTag = ${serdeCtx.tagReader}.nextTag()")
                     withBlock(
-                        "if (resultTag == null || resultTag.tag.name != resultWrapperName) {",
+                        "if (resultTag == null || resultTag.tagName != resultWrapperName) {",
                         "}",
                     ) {
                         write("throw #T(#S)", RuntimeTypes.Serde.DeserializationException, "invalid result, expected \$resultWrapperName; found `\${resultTag?.tag}`")
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
index ec17ca24423..65751cefad6 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
@@ -125,7 +125,7 @@ private class Ec2QueryParserGenerator(
                 RuntimeTypes.Serde.SerdeXml.XmlTagReader,
             ) {
                 withBlock(
-                    "if (root.tag.name != #S) {",
+                    "if (root.tagName != #S) {",
                     "}",
                     "Response",
                 ) {
@@ -134,7 +134,7 @@ private class Ec2QueryParserGenerator(
 
                 write("val errorsTag = root.nextTag()")
                 withBlock(
-                    "if (errorsTag == null || errorsTag.tag.name != #S) {",
+                    "if (errorsTag == null || errorsTag.tagName != #S) {",
                     "}",
                     "Errors",
                 ) {
@@ -143,7 +143,7 @@ private class Ec2QueryParserGenerator(
 
                 write("val errTag = errorsTag.nextTag()")
                 withBlock(
-                    "if (errTag == null || errTag.tag.name != #S) {",
+                    "if (errTag == null || errTag.tagName != #S) {",
                     "}",
                     "Error",
                 ) {
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
index 03fc1a57419..27eada3b0ad 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
@@ -157,7 +157,7 @@ object RestXmlErrors {
                 RuntimeTypes.Serde.SerdeXml.XmlTagReader,
             ) {
                 withBlock(
-                    "if (root.tag.name != #S) {",
+                    "if (root.tagName != #S) {",
                     "}",
                     "ErrorResponse",
                 ) {
@@ -166,7 +166,7 @@ object RestXmlErrors {
 
                 write("val errTag = root.nextTag()")
                 withBlock(
-                    "if (errTag == null || errTag.tag.name != #S) {",
+                    "if (errTag == null || errTag.tagName != #S) {",
                     "}",
                     "Error",
                 ) {
@@ -201,7 +201,7 @@ object RestXmlErrors {
                 RuntimeTypes.Serde.SerdeXml.XmlTagReader,
             ) {
                 withBlock(
-                    "if (root.tag.name != #S) {",
+                    "if (root.tagName != #S) {",
                     "}",
                     "Error",
                 ) {
diff --git a/services/route53/common/src/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshalling.kt b/services/route53/common/src/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshalling.kt
index 4d240e353e9..e61e2a62021 100644
--- a/services/route53/common/src/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshalling.kt
+++ b/services/route53/common/src/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshalling.kt
@@ -6,7 +6,6 @@ package aws.sdk.kotlin.services.route53.internal
 
 import aws.sdk.kotlin.services.route53.model.InvalidChangeBatch
 import aws.smithy.kotlin.runtime.awsprotocol.ErrorDetails
-import aws.smithy.kotlin.runtime.awsprotocol.xml.parseRestXmlErrorResponse
 import aws.smithy.kotlin.runtime.serde.xml.*
 
 internal fun parseRestXmlInvalidChangeBatchResponse(payload: ByteArray): InvalidChangeBatchErrorResponse? =
@@ -14,17 +13,11 @@ internal fun parseRestXmlInvalidChangeBatchResponse(payload: ByteArray): Invalid
 
 internal fun deserializeInvalidChangeBatchError(builder: InvalidChangeBatch.Builder, payload: ByteArray): InvalidChangeBatchErrorResponse? {
     val root = xmlTagReader(payload)
-    if (root.tag.name == "ErrorResponse") {
-        val errDetails = parseRestXmlErrorResponse(payload)
-        builder.message = errDetails.message
-        return InvalidChangeBatchErrorResponse(errDetails, builder.build())
-    }
-
     var requestId: String? = null
 
     loop@while (true) {
         val curr = root.nextTag() ?: break@loop
-        when (curr.tag.name) {
+        when (curr.tagName) {
             "Message", "message" -> builder.message = curr.data()
             "Messages", "messages" -> builder.messages = deserializeMessages(curr)
             "RequestId" -> requestId = curr.data()
@@ -39,7 +32,7 @@ private fun deserializeMessages(root: XmlTagReader): List<String> {
     val result = mutableListOf<String>()
     loop@while (true) {
         val curr = root.nextTag() ?: break@loop
-        when (curr.tag.name) {
+        when (curr.tagName) {
             "Message" -> {
                 val el = curr.tryData().getOrNull() ?: continue@loop
                 result.add(el)
diff --git a/services/route53/common/test/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshallingTest.kt b/services/route53/common/test/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshallingTest.kt
index de99fd13630..e8a3b2e5b3d 100644
--- a/services/route53/common/test/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshallingTest.kt
+++ b/services/route53/common/test/aws/sdk/kotlin/services/route53/internal/ChangeResourceRecordSetsUnmarshallingTest.kt
@@ -5,7 +5,6 @@
 package aws.sdk.kotlin.services.route53.internal
 
 import aws.sdk.kotlin.services.route53.model.InvalidChangeBatch
-import aws.sdk.kotlin.services.route53.model.Route53Exception
 import aws.sdk.kotlin.services.route53.serde.ChangeResourceRecordSetsOperationDeserializer
 import aws.smithy.kotlin.runtime.http.Headers
 import aws.smithy.kotlin.runtime.http.HttpBody
@@ -107,34 +106,4 @@ class ChangeResourceRecordSetsUnmarshallingTest {
         assertEquals(listOf<String>("InvalidChangeBatch message 1", "InvalidChangeBatch message 2"), exception.messages)
         assertEquals("InvalidChangeBatch message 3", exception.message)
     }
-
-    @Test
-    fun changeResourceRecordSetsError() {
-        val bodyText = """
-            <?xml version="1.0"?>
-            <ErrorResponse xmlns="http://route53.amazonaws.com/doc/2016-09-07/">
-              <Error>
-                <Type>Sender</Type>
-                <Code>MalformedXML</Code>
-                <Message>ChangeResourceRecordSets error message</Message>
-              </Error>
-              <RequestId>b25f48e8-84fd-11e6-80d9-574e0c4664cb</RequestId>
-            </ErrorResponse>
-        """.trimIndent()
-
-        val response: HttpResponse = HttpResponse(
-            HttpStatusCode.BadRequest,
-            Headers.Empty,
-            HttpBody.fromBytes(bodyText.encodeToByteArray()),
-        )
-
-        val call = HttpCall(HttpRequestBuilder().build(), response)
-
-        val exception = assertFailsWith<Route53Exception> {
-            runBlocking {
-                ChangeResourceRecordSetsOperationDeserializer().deserialize(ExecutionContext(), call)
-            }
-        }
-        assertEquals("ChangeResourceRecordSets error message", exception.message)
-    }
 }
diff --git a/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/Handle200ErrorsInterceptor.kt b/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/Handle200ErrorsInterceptor.kt
index aafdf1718e5..c5fe16baeda 100644
--- a/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/Handle200ErrorsInterceptor.kt
+++ b/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/Handle200ErrorsInterceptor.kt
@@ -32,7 +32,7 @@ internal object Handle200ErrorsInterceptor : HttpInterceptor {
         // according to the knowledge center article above we should treat these as 5xx,
         // our retry policy will handle standard error codes like `SlowDown`
         val statusCode = HttpStatusCode.InternalServerError
-            .takeIf { token?.qualifiedName?.local == "Error" }
+            .takeIf { token?.name?.local == "Error" }
             ?: response.status
         return response.copy(status = statusCode, body = HttpBody.fromBytes(payload))
     }
diff --git a/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/S3ErrorMetadata.kt b/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/S3ErrorMetadata.kt
index 6f5cb7fef85..45074546fcd 100644
--- a/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/S3ErrorMetadata.kt
+++ b/services/s3/common/src/aws/sdk/kotlin/services/s3/internal/S3ErrorMetadata.kt
@@ -52,7 +52,7 @@ internal fun parseS3ErrorResponse(payload: ByteArray): S3ErrorDetails {
 
     loop@ while (true) {
         val curr = root.nextTag() ?: break@loop
-        when (curr.tag.name) {
+        when (curr.tagName) {
             "Code" -> code = curr.data()
             "Message", "message" -> message = curr.data()
             "RequestId" -> requestId = curr.data()

From 0ade972b3eec01a0129b6a28014c29866d0612ff Mon Sep 17 00:00:00 2001
From: Aaron J Todd <todaaron@amazon.com>
Date: Tue, 27 Feb 2024 14:44:55 -0500
Subject: [PATCH 09/11] remove fixme

---
 .../amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt        | 1 -
 1 file changed, 1 deletion(-)

diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
index 27eada3b0ad..c7c834c3175 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
@@ -82,7 +82,6 @@ class RestXmlParserGenerator(
         else -> super.payloadDeserializer(ctx, shape, members)
     }
 
-    // FIXME - reconcile
     private fun explicitBoundStructureDeserializer(
         ctx: ProtocolGenerator.GenerationContext,
         boundMember: MemberShape,

From d78f5d479a05f7aab1472a19cc2b97fb32ce34a6 Mon Sep 17 00:00:00 2001
From: Aaron J Todd <todaaron@amazon.com>
Date: Tue, 27 Feb 2024 20:49:21 -0500
Subject: [PATCH 10/11] tickle ci


From 8dbaea8978bcabb270a3f0a16e68b8018957b504 Mon Sep 17 00:00:00 2001
From: Aaron J Todd <todaaron@amazon.com>
Date: Wed, 28 Feb 2024 21:48:23 -0500
Subject: [PATCH 11/11] bump versions

---
 gradle/libs.versions.toml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 88a30d55c61..f19bf376040 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -9,8 +9,8 @@ coroutines-version = "1.7.3"
 atomicfu-version = "0.23.1"
 
 # smithy-kotlin codegen and runtime are versioned separately
-smithy-kotlin-runtime-version = "1.0.16-SNAPSHOT"
-smithy-kotlin-codegen-version = "0.30.17-SNAPSHOT"
+smithy-kotlin-runtime-version = "1.0.16"
+smithy-kotlin-codegen-version = "0.30.17"
 
 # codegen
 smithy-version = "1.42.0"