C bindings: Implement _DeepCopy() & some unittests.

mojo/public/c/bindings/lib/type_descriptor.c

Index: mojo/public/c/bindings/lib/type_descriptor.c
diff --git a/mojo/public/c/bindings/lib/type_descriptor.c b/mojo/public/c/bindings/lib/type_descriptor.c
index 2846965b02ee033f267a1463a89ff4fbd5702065..098237c0d90f0b4d84f371e3b19a350591fcb244 100644
--- a/mojo/public/c/bindings/lib/type_descriptor.c
+++ b/mojo/public/c/bindings/lib/type_descriptor.c
@@ -84,7 +84,7 @@ static void encode_pointer(union MojomPointer* pointer, uint32_t max_offset) {
   if (pointer->ptr == NULL) {
     pointer->offset = 0;
   } else {
-    assert((char*)pointer->ptr > (char*)pointer);
+    assert((char*)(pointer->ptr) > (char*)pointer);
     assert((char*)pointer->ptr - (char*)pointer < max_offset);
     pointer->offset = (char*)(pointer->ptr) - (char*)pointer;
   }
@@ -399,3 +399,66 @@ MojomValidationResult MojomType_DispatchValidate(
   }
   return MOJOM_VALIDATION_ERROR_NONE;
 }
+
+void move_handle(MojoHandle* in_handle, MojoHandle* out_handle) {
+  *out_handle = *in_handle;
+  *in_handle = MOJO_HANDLE_INVALID;
+}
+
+void MojomType_DispatchDeepCopy(struct MojomBuffer* buffer,
+                        enum MojomTypeDescriptorType in_elem_type,
+                        const void* in_type_desc,
+                        void* in_data,
+                        void* out_data) {
+  assert(in_data);
+
+  struct MojomUnionLayout* in_union_data = (struct MojomUnionLayout*)in_data;
+  struct MojomUnionLayout* out_union_data = (struct MojomUnionLayout*)out_data;
+  union MojomPointer* in_pointer = in_data;
+  switch (in_elem_type) {
+    case MOJOM_TYPE_DESCRIPTOR_TYPE_MAP_PTR:
+    case MOJOM_TYPE_DESCRIPTOR_TYPE_STRUCT_PTR:
+      if (in_pointer->ptr == NULL) {
+        ((union MojomPointer*)out_data)->ptr = NULL;
+        break;
+      }
+      ((union MojomPointer*)out_data)->ptr = MojomStruct_DeepCopy(
+          buffer, (const struct MojomTypeDescriptorStruct*)in_type_desc,
+          ((union MojomPointer*)in_data)->ptr);
+      break;
+    case MOJOM_TYPE_DESCRIPTOR_TYPE_ARRAY_PTR:
+      if (in_pointer->ptr == NULL) {
+        ((union MojomPointer*)out_data)->ptr = NULL;
+        break;
+      }
+      ((union MojomPointer*)out_data)->ptr = MojomArray_DeepCopy(
+          buffer, (const struct MojomTypeDescriptorArray*)in_type_desc,
+          ((union MojomPointer*)in_data)->ptr);
+      break;
+    case MOJOM_TYPE_DESCRIPTOR_TYPE_UNION_PTR:
+      in_union_data = ((union MojomPointer*)in_data)->ptr;
+      if (in_union_data == NULL) {
+        ((union MojomPointer*)out_data)->ptr = NULL;
+        break;
+      }
+      out_union_data =
+          MojomBuffer_Allocate(buffer, sizeof(struct MojomUnionLayout));
+      ((union MojomPointer*)out_data)->ptr = out_union_data;
+      // Fall through.
+    case MOJOM_TYPE_DESCRIPTOR_TYPE_UNION:
+      MojomUnion_DeepCopy(buffer,
+                          (const struct MojomTypeDescriptorUnion*)in_type_desc,
+                          in_union_data,
+                          out_union_data);
+      break;
+    case MOJOM_TYPE_DESCRIPTOR_TYPE_HANDLE:
+      move_handle((MojoHandle*)in_data, (MojoHandle*)out_data);
+      break;
+    case MOJOM_TYPE_DESCRIPTOR_TYPE_INTERFACE:
+      move_handle(&((struct MojomInterfaceData*)in_data)->handle,
+                  &((struct MojomInterfaceData*)out_data)->handle);
+      break;
+    case MOJOM_TYPE_DESCRIPTOR_TYPE_POD:
+      break;
+  }
+}