dawn_wire: Support deserializing s->c chained structs

Chained structs *may* contain objects which means
deserialization may need an ObjectIdResolver.
However, in practice, we never need to send chained
structs from the server to the client that contain objects for
a valid command.

The one upcoming need for chained server->client structs is to
serialize limit structs.

Because limit structs never need objects, we provide a dummy
implementation of the ObjectIdResolver which always yields an error.
An analogous change is done for ObjectIdProvider.
These classes will be used in a follow-up CL.

Bug: dawn:685
Change-Id: I1c0f3f2d080377f2e1a77bc6e896f24d3d9ab931
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/63981
Commit-Queue: Austin Eng <enga@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>

generator/templates/dawn_wire/WireCmd.cpp

@@ -57,7 +57,7 @@
 {% macro serialize_member(member, in, out) %}
     {%- if member.type.category == "object" -%}
         {%- set Optional = "Optional" if member.optional else "" -%}
-        {{out}} = provider.Get{{Optional}}Id({{in}});
+        WIRE_TRY(provider.Get{{Optional}}Id({{in}}, &{{out}}));
     {% elif member.type.category == "structure"%}
         {%- set Provider = ", provider" if member.type.may_have_dawn_object else "" -%}
         {% if member.annotation == "const*const*" %}
@@ -416,8 +416,8 @@ namespace {
     }
 
     WireResult {{Cmd}}::Serialize(size_t commandSize, SerializeBuffer* buffer
-        {%- if not is_return -%}
-            , const ObjectIdProvider& objectIdProvider
+        {%- if command.may_have_dawn_object -%}
+            , const ObjectIdProvider& provider
         {%- endif -%}
     ) const {
         {{Name}}Transfer* transfer;
@@ -426,7 +426,7 @@ namespace {
 
         WIRE_TRY({{Name}}Serialize(*this, transfer, buffer
             {%- if command.may_have_dawn_object -%}
-                , objectIdProvider
+                , provider
             {%- endif -%}
         ));
         return WireResult::Success;
@@ -666,6 +666,36 @@ namespace dawn_wire {
         {{ write_command_serialization_methods(command, True) }}
     {% endfor %}
 
+    // Implementation of ObjectIdResolver that always errors.
+    // Used when the generator adds a provider argument because of a chained
+    // struct, but in practice, a chained struct in that location is invalid.
+    class ErrorObjectIdResolver final : public ObjectIdResolver {
+        public:
+            {% for type in by_category["object"] %}
+                WireResult GetFromId(ObjectId id, {{as_cType(type.name)}}* out) const override {
+                    return WireResult::FatalError;
+                }
+                WireResult GetOptionalFromId(ObjectId id, {{as_cType(type.name)}}* out) const override {
+                    return WireResult::FatalError;
+                }
+            {% endfor %}
+    };
+
+    // Implementation of ObjectIdProvider that always errors.
+    // Used when the generator adds a provider argument because of a chained
+    // struct, but in practice, a chained struct in that location is invalid.
+    class ErrorObjectIdProvider final : public ObjectIdProvider {
+        public:
+            {% for type in by_category["object"] %}
+                WireResult GetId({{as_cType(type.name)}} object, ObjectId* out) const override {
+                    return WireResult::FatalError;
+                }
+                WireResult GetOptionalId({{as_cType(type.name)}} object, ObjectId* out) const override {
+                    return WireResult::FatalError;
+                }
+            {% endfor %}
+    };
+
         // Implementations of serialization/deserialization of WPGUDeviceProperties.
         size_t SerializedWGPUDevicePropertiesSize(const WGPUDeviceProperties* deviceProperties) {
             return sizeof(WGPUDeviceProperties) +

generator/templates/dawn_wire/WireCmd.h

@@ -66,8 +66,8 @@ namespace dawn_wire {
     class ObjectIdProvider {
         public:
             {% for type in by_category["object"] %}
-                virtual ObjectId GetId({{as_cType(type.name)}} object) const = 0;
-                virtual ObjectId GetOptionalId({{as_cType(type.name)}} object) const = 0;
+                virtual WireResult GetId({{as_cType(type.name)}} object, ObjectId* out) const = 0;
+                virtual WireResult GetOptionalId({{as_cType(type.name)}} object, ObjectId* out) const = 0;
             {% endfor %}
     };
 
@@ -98,11 +98,17 @@ namespace dawn_wire {
 
         //* Serialize the structure and everything it points to into serializeBuffer which must be
         //* big enough to contain all the data (as queried from GetRequiredSize).
-        WireResult Serialize(size_t commandSize, SerializeBuffer* serializeBuffer
-            {%- if not is_return_command -%}
-                , const ObjectIdProvider& objectIdProvider
-            {%- endif -%}
-        ) const;
+        {% if command.may_have_dawn_object %}
+            WireResult Serialize(size_t commandSize, SerializeBuffer* serializeBuffer, const ObjectIdProvider& objectIdProvider) const;
+        {% else %}
+            WireResult Serialize(size_t commandSize, SerializeBuffer* serializeBuffer) const;
+            // Override which drops the provider if it's not needed.
+            WireResult Serialize(size_t commandSize,
+                                 SerializeBuffer* serializeBuffer,
+                                 const ObjectIdProvider&) const {
+                return Serialize(commandSize, serializeBuffer);
+            }
+        {% endif %}
 
         //* Deserializes the structure from a buffer, consuming a maximum of *size bytes. When this
         //* function returns, buffer and size will be updated by the number of bytes consumed to

generator/templates/dawn_wire/client/ClientBase.h

@@ -49,14 +49,18 @@ namespace dawn_wire { namespace client {
       private:
         // Implementation of the ObjectIdProvider interface
         {% for type in by_category["object"] %}
-            ObjectId GetId({{as_cType(type.name)}} object) const final {
-                return object == nullptr ? 0 : reinterpret_cast<{{as_wireType(type)}}>(object)->id;
-            }
-            ObjectId GetOptionalId({{as_cType(type.name)}} object) const final {
+            WireResult GetId({{as_cType(type.name)}} object, ObjectId* out) const final {
+                ASSERT(out != nullptr);
                 if (object == nullptr) {
-                    return 0;
+                    return WireResult::FatalError;
                 }
-                return GetId(object);
+                *out = reinterpret_cast<{{as_wireType(type)}}>(object)->id;
+                return WireResult::Success;
+            }
+            WireResult GetOptionalId({{as_cType(type.name)}} object, ObjectId* out) const final {
+                ASSERT(out != nullptr);
+                *out = (object == nullptr ? 0 : reinterpret_cast<{{as_wireType(type)}}>(object)->id);
+                return WireResult::Success;
             }
         {% endfor %}
 

src/tests/unittests/wire/WireWGPUDevicePropertiesTests.cpp

@@ -21,7 +21,7 @@ class WireWGPUDevicePropertiesTests : public testing::Test {};
 
 // Test that the serialization and deserialization of WGPUDeviceProperties can work correctly.
 TEST_F(WireWGPUDevicePropertiesTests, SerializeWGPUDeviceProperties) {
-    WGPUDeviceProperties sentWGPUDeviceProperties;
+    WGPUDeviceProperties sentWGPUDeviceProperties = {};
     sentWGPUDeviceProperties.textureCompressionBC = true;
     // Set false to test that the serialization can handle both true and false correctly.
     sentWGPUDeviceProperties.pipelineStatisticsQuery = false;