mojo: Validate fixed size array for the mojo java bindings.

mojo/public/tools/bindings/generators/mojom_java_generator.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Generates java source files from a mojom.Module."""
 
 import argparse
 import ast
 import os
 import re
@@ skipping 134 matching lines @@
       return _DecodeMethodName(mojom.INT32)
     if mojom.IsInterfaceRequestKind(kind):
       return "readInterfaceRequest"
     if mojom.IsInterfaceKind(kind):
       return "readServiceInterface"
     return _spec_to_decode_method[kind.spec]
   methodName = _DecodeMethodName(kind)
   params = [ str(offset) ]
   if (kind == mojom.BOOL):
     params.append(str(bit))
+  if mojom.IsAnyArrayKind(kind):
+    if mojom.IsFixedArrayKind(kind):
+      params.append(str(kind.length))
+    else:
+      params.append(
+        "org.chromium.mojo.bindings.BindingsHelper.UNSPECIFIED_ARRAY_LENGTH");
   if mojom.IsInterfaceKind(kind):
     params.append('%s.MANAGER' % GetJavaType(context, kind))
   if mojom.IsAnyArrayKind(kind) and mojom.IsInterfaceKind(kind.kind):
     params.append('%s.MANAGER' % GetJavaType(context, kind.kind))
   return '%s(%s)' % (methodName, ', '.join(params))
 
 @contextfilter
 def EncodeMethod(context, kind, variable, offset, bit):
   params = [ variable, str(offset) ]
   if (kind == mojom.BOOL):
     params.append(str(bit))
+  if mojom.IsAnyArrayKind(kind):
+    if mojom.IsFixedArrayKind(kind):
+      params.append(str(kind.length))
+    else:
+      params.append(
+        "org.chromium.mojo.bindings.BindingsHelper.UNSPECIFIED_ARRAY_LENGTH");

[yzshen1, 2014/08/29 16:32:24]

One nit: Other bindings use 0 as "unspecified length". I understand that they
don't affect each other, but it may worth considering to unify them:
https://code.google.com/p/chromium/codesearch#chromium/src/mojo/public/tools/...

[qsr, 2014/09/01 09:07:00]

 Not sure to understand exactly what to do here. The -1, 0 debate aside, I'm
using a constant here to make the code more readable. Do you want use to do this
in all bindings?

 For the -1, 0, I will push like this, and change to 0 if the discussion ends up
deciding we never want fixed size arrays of size 0.

   if mojom.IsInterfaceKind(kind):
     params.append('%s.MANAGER' % GetJavaType(context, kind))
   if mojom.IsAnyArrayKind(kind) and mojom.IsInterfaceKind(kind.kind):
     params.append('%s.MANAGER' % GetJavaType(context, kind.kind))
   return 'encode(%s)' % ', '.join(params)
 
 def GetPackage(module):
   if 'JavaPackage' in module.attributes:
     return ParseStringAttribute(module.attributes['JavaPackage'])
   # Default package.
@@ skipping 140 matching lines @@
 
   java_filters = {
     "interface_response_name": GetInterfaceResponseName,
     "constant_value": ConstantValue,
     "default_value": DefaultValue,
     "decode_method": DecodeMethod,
     "expression_to_text": ExpressionToText,
     "encode_method": EncodeMethod,
     "has_method_with_response": HasMethodWithResponse,
     "has_method_without_response": HasMethodWithoutResponse,
+    "is_fixed_array_kind": mojom.IsFixedArrayKind,
     "is_handle": mojom.IsNonInterfaceHandleKind,
     "is_pointer_array_kind": IsPointerArrayKind,
     "is_struct_kind": mojom.IsStructKind,
     "java_type": GetJavaType,
     "method_ordinal_name": GetMethodOrdinalName,
     "name": GetNameForElement,
     "new_array": NewArray,
     "response_struct_from_method": GetResponseStructFromMethod,
     "struct_from_method": GetStructFromMethod,
     "struct_size": lambda ps: ps.GetTotalSize() + _HEADER_SIZE,
@@ skipping 76 matching lines @@
   def GetJinjaParameters(self):
     return {
       'lstrip_blocks': True,
       'trim_blocks': True,
     }
 
   def GetGlobals(self):
     return {
       'module': self.module,
     }