Code generation for extensions api

tools/json_schema_compiler/generate_cc.py

Index: tools/json_schema_compiler/generate_cc.py
diff --git a/tools/json_schema_compiler/generate_cc.py b/tools/json_schema_compiler/generate_cc.py
new file mode 100644
index 0000000000000000000000000000000000000000..5a58a841e84bbb39642c912605af92bef578faa0
--- /dev/null
+++ b/tools/json_schema_compiler/generate_cc.py
@@ -0,0 +1,287 @@
+# Copyright (c) 2011 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.
+
+from model import PropertyType
+import code
+import type_manager
+
+class CC_Generator(object):

[not at google - send to devlin, 2012/01/13 02:14:09]

I like this name, so the file should be called cc_generator.py.

Also I believe that the style is just "class CCGenerator:" ...

[calamity, 2012/01/16 04:01:06]

Done.

+  """A .cc generator for a namespace."""
+
+  def __init__(self, namespace, model):
+    self.type_manager = type_manager.TypeManager(namespace, model)
+    self.namespace = namespace
+
+  def generate(self):
+    """Generates the .cc code for a single namespace.

[not at google - send to devlin, 2012/01/13 02:14:09]

"""Generates a code.Code object with the .cc code for a namespace.
"""

[calamity, 2012/01/16 04:01:06]

Done.

+
+    Returns a code.Code object.
+    """
+    include_path = self.namespace.parent_dir
+    filename = self.namespace.filename
+    c = code.Code()
+    (c.append(code.CHROMIUM_LICENSE).append()

[not at google - send to devlin, 2012/01/13 02:14:09]

put the second .append() on its own line; this would mirror the generated code
more closely.

[calamity, 2012/01/16 04:01:06]

Done.

+      .append(code.WARNING_MESSAGE % self.namespace.parent_path)
+      .append()
+      .append('#include "tools/json_schema_compiler/util.h"')
+      .append('#include "%s/%s.h"' % (include_path, filename))
+  #    .append('#include "base/json/json_converter.h"')

[not at google - send to devlin, 2012/01/13 02:14:09]

delete

[calamity, 2012/01/16 04:01:06]

Done.

+      .append()
+      .append('namespace extensions {')

[not at google - send to devlin, 2012/01/13 02:14:09]

"extensions" needs to be taken from the command-line options.

[calamity, 2012/01/16 04:01:06]

Done.

+      .append('namespace %s {' % filename)
+      .append()
+      .append('//')
+      .append('// Types')
+      .append('//')
+      .append()
+    )
+    for tipe in self.namespace.types.values():
+      c.add(self.generate_type(tipe))

[not at google - send to devlin, 2012/01/13 02:14:09]

pull the last "c.append()" out of generate_type and into here.

[calamity, 2012/01/16 04:01:06]

Done. Also did the same with all other "c.append()"s at the end of functions

+    c.append('//')
+    c.append('// Functions')
+    c.append('//')
+    c.append()
+    for function in self.namespace.functions.values():
+      c.add(self.generate_function(function))
+    c.append('} // namespace extensions')

[not at google - send to devlin, 2012/01/13 02:14:09]

ditto extensions

[calamity, 2012/01/16 04:01:06]

Done.

+    c.append('} // namespace %s' % filename)
+    # TODO(calamity): Events
+    return c
+
+  def generate_type(self, tipe):
+    """Generates the function definitions for a type in the namespace."""

[not at google - send to devlin, 2012/01/13 02:14:09]

... for a type.
"""

(no need for "in the namespace")

[calamity, 2012/01/16 04:01:06]

Done.

+    c = code.Code()
+    classname = '%s' % (tipe.name)

[not at google - send to devlin, 2012/01/13 02:14:09]

can delete this line and inline it?

...
c.substitute({'classname': tipe.name})

[calamity, 2012/01/16 04:01:06]

Done.

+
+    c.append('%(classname)s::%(classname)s() {}')
+    c.append('%(classname)s::~%(classname)s() {}')
+    c.substitute({'classname': classname})
+    c.append()
+
+    c.add(self.generate_type_populate(tipe))
+    # TODO(calamity): deal with non-serializable
+    c.add(self.generate_type_tovalue(tipe))
+    c.append()
+
+    return c
+
+  def generate_type_populate(self, tipe):
+    """Generates the function for populating a type given a pointer to it."""
+    c = code.Code()
+    c.append('// static')
+    c.sblock('bool %(name)s::Populate(const Value& value, %(name)s* out) {')
+    c.substitute({'name': tipe.name})
+    c.append('if (!value.IsType(Value::TYPE_DICTIONARY))')
+    c.append('  return false;')
+    c.append('const DictionaryValue* dict = '
+        'static_cast<const DictionaryValue*>(&value);')
+
+    c.append()
+    # TODO(calamity): this doesn't even handle single properties.
+    # add ALL the types
+    for prop in tipe.properties.values():
+      sub = {'name': prop.name}
+      if prop.type == PropertyType.ARRAY:
+        if prop.item_type.type == PropertyType.REF:
+          if prop.optional:
+            c.append('if (!json_schema_compiler::util::GetOptionalTypes<%(type)s>(*dict,')

[not at google - send to devlin, 2012/01/13 02:14:09]

this line is too long.

this makes me think though -- I think it would be nice to have a few global
variables that are automatically resolved at the top level (although probably by
the Code object, since the Code object needs to know about any global
substitutions so that unresolved ones can be error checked, anyway)

Things like
 - the path to the utils ('json_schema_compiler::util' in this case)
 - the namepace that everything is being generated to ('extensions' in this
case)

this line could then become

c.append("if (!%(global.utils)s::GetOptionalTypes(...)")

likewise where you've written "extensions", could be %(global.namespace)s or
whatever you've been calling it.

[calamity, 2012/01/16 04:01:06]

Yeah, but as always it's a tradeoff between usability and readability. Wouldn't
that introduce global state?

[not at google - send to devlin, 2012/01/17 01:59:24]

Not really, it's not global state because it's not state.  They're constants.  I
think it would be nice to have an explicit global constant system.

+            c.append('    "%(name)s", &out->%(name)s))')
+            c.append('  return false;')
+          else:
+            c.append('if (!json_schema_compiler::util::GetTypes<%(type)s>(*dict,')
+            c.append('    "%(name)s", &out->%(name)s))')
+            c.append('  return false;')
+          sub['type'] = self.type_manager.get_generic_type(prop.item_type)
+        elif prop.item_type.json_type == 'string':
+          if prop.optional:
+            c.append('if (!json_schema_compiler::util::GetOptionalStrings'
+                '(*dict, "%(name)s", &out->%(name)s))')
+            c.append('  return false;')
+          else:
+            c.append('if (!json_schema_compiler::util::GetStrings'
+                '(*dict, "%(name)s", &out->%(name)s))')
+            c.append('  return false;')

[calamity, 2012/01/16 04:01:06]

Clearly this if block is going to grow. On a dev branch I've pulled this into
it's own class that deals with interactions with util.cc.

[not at google - send to devlin, 2012/01/17 01:59:24]

I'm missing the context for this comment.

+        else:
+          raise NotImplementedError(prop.item_type.json_type)
+      elif prop.type == PropertyType.FUNDAMENTAL:
+        c.append('if(!dict->%s)' % get_fundamental_value(prop,
+            '&out->%s' % prop.name))
+        c.append('  return false;')
+      else:
+        raise NotImplementedError(prop.type)
+      c.substitute(sub)
+    c.append('return true;')
+    c.eblock('}')
+    c.append()
+    return c
+
+  def generate_type_tovalue(self, tipe):
+    """Generates a function that serializes the type into a
+    |DictionaryValue|."""
+    c = code.Code()
+    c.sblock('DictionaryValue* %s::ToValue() const {' % tipe.name)
+    name = tipe.name.lower()
+    c.append('DictionaryValue* value = new DictionaryValue();')
+    c.append()
+    for prop in tipe.properties.values():
+      prop_name = name + '_' + prop.name if name else prop.name
+      this_var =  prop.name
+      c.add(self.create_value_from_property(prop_name, prop, this_var))
+    c.append()
+    c.append('return value;')
+
+    c.eblock('}')
+    return c
+
+  # TODO(calamity): object and choices proptypes
+  def create_value_from_property(self, name, prop, var):
+    """Generates code to serialize a single property in a type."""
+    c = code.Code()
+    if prop.type == PropertyType.FUNDAMENTAL:
+      c.append(
+          'Value* %s_value = %s;' % (name, create_fundamental_value(prop, var)))
+    elif prop.type == PropertyType.ARRAY:
+      if prop.item_type.json_type == 'string':
+        if prop.optional:
+          c.append('json_schema_compiler::util::SetOptionalStrings(%s, "%s", value);'
+              % (var, prop.name))
+        else:
+          c.append('json_schema_compiler::util::SetStrings(%s, "%s", value);' %
+              (var, prop.name))
+      else:
+        item_name = name + '_single'
+        c.append('ListValue* %(name)s_value = new ListValue();')
+        c.append('for (%(it_type)s::iterator it = %(var)s->begin();')
+        c.sblock('    it != %(var)s->end(); ++it) {')
+        c.add(self.create_value_from_property(item_name, prop.item_type, '*it'))
+        c.append('%(name)s_value->Append(%(prop_val)s_value);')
+        c.substitute(
+            {'it_type': self.type_manager.get_type(prop),
+                'name': name, 'var': var, 'prop_val': item_name})
+        c.eblock('}')
+    elif prop.type == PropertyType.REF:
+      c.append('Value* %s_value = %s.ToValue();' % (name, var))
+    else:
+      raise NotImplementedError
+    return c
+
+  def generate_function(self, function):
+    """Generates the definitions for function structs."""
+    classname = code.cpp_name(function.name)
+    c = code.Code()
+
+    # Params::Populate function
+    if function.params:
+      c.append('%(name)s::Params::Params() {}')
+      c.append('%(name)s::Params::~Params() {}')
+      c.append()
+      c.add(self.generate_function_params_populate(function))
+
+    # Result::Create function
+    c.add(self.generate_function_result_create(function))
+
+    c.substitute({'name': classname})
+
+    return c
+
+  def generate_function_params_populate(self, function):
+    """Generate function to populate an instance of Params given a pointer."""
+    classname = code.cpp_name(function.name)
+    c = code.Code()
+    c.append('// static')
+    c.append('bool %(classname)s::Params::Populate(const ListValue& args,')
+    c.sblock('    %(classname)s::Params* out) {')
+    c.substitute({'classname': classname})
+    c.append('if (args.GetSize() != %d)' % len(function.params))
+    c.append('  return false;')
+
+    # TODO(calamity): generalize, needs to move to function to do populates for
+    # wider variety of args
+    for i, param in enumerate(function.params):
+      sub = {'name': param.name, 'pos': i}
+      c.append()
+      # TODO(calamity): Make valid for not just objects
+      c.append('DictionaryValue* %(name)s_param = NULL;')
+      c.append('if (!args.GetDictionary(%(pos)d, &%(name)s_param))')
+      c.append('  return false;')
+      if param.type == PropertyType.REF:
+        c.append('if (!%(ctype)s::Populate(*%(name)s_param, &out->%(name)s))')
+        c.append('  return false;')
+        sub['ctype'] = self.type_manager.get_type(param)
+      elif param.type == PropertyType.FUNDAMENTAL:
+        #XXX THIS IS WRONG
+        c.append('// TODO Needs some sort of casting')
+        c.append('if (!%(name)s_param->' +
+            get_fundamental_value(param,'&out->%s' % param.name) +');')
+        c.append('  return false;')
+      elif param.type == PropertyType.OBJECT:
+        c.append('if(!%(ctype)s::Populate(*%(name)s_param, &out->%(name)s))')
+        c.append('  return false;')
+        sub['ctype'] = self.type_manager.get_type(param)
+      elif param.type == PropertyType.CHOICES:
+        c.append('// TODO handle chocies')
+      else:
+        raise NotImplementedError(param.type)
+      c.substitute(sub)
+    c.append()
+    c.append('return true;')
+    c.eblock('}')
+    c.append()
+
+    return c
+
+  def generate_function_result_create(self, function):
+    """Generate function to create a Result given the return value."""
+    classname = code.cpp_name(function.name)
+    c = code.Code()
+    c.append('// static')
+    param = function.callback.param
+    arg = ''
+    if param:
+      arg = 'const ' + self.type_manager.parameter_declaration(param,
+          type_modifiers={PropertyType.REF: type_manager.ParamFormat.REFERENCE})
+    c.sblock('Value* %(classname)s::Result::Create(%(arg)s) {')
+    sub = {'classname': classname, 'arg': arg}
+    # TODO(calamity): Choices
+    if not param:
+      c.append('return Value::CreateNullValue();')
+    else:
+      sub['argname'] = param.name
+      if param.type == PropertyType.FUNDAMENTAL:
+        c.append('return %s;' % create_fundamental_value(param, param.name))
+      elif param.type == PropertyType.REF:
+        c.append('DictionaryValue* result = new DictionaryValue();')
+        c.append('result->Set("%(argname)s", %(argname)s.ToValue());')

[not at google - send to devlin, 2012/01/13 02:14:09]

SetWithoutPathExpansion

(need to audit this whole file for that..)

[calamity, 2012/01/16 04:01:06]

Done.

+        c.append('return result;')
+      elif param.type == PropertyType.OBJECT:
+        c.append('// TODO object stuff')
+      elif param.type == PropertyType.ARRAY:
+        c.append('// TODO array stuff')
+      else:
+        raise NotImplementedError(param.type)
+    c.substitute(sub)
+    c.eblock('}')
+    c.append()
+    return c
+
+def create_fundamental_value(prop, var):
+  """Returns the C++ code for creating a value of the given property type
+  using the given variable."""
+  return {
+      'string': 'Value::CreateStringValue(%s)',
+      'boolean': 'Value::CreateBooleanValue(%s)',
+      'integer': 'Value::CreateIntegerValue(%s)',
+      'double': 'Value::CreateDoubleValue(%s)',
+  }[prop.json_type] % var
+
+
+def get_fundamental_value(prop, var):
+  """Returns the C++ code for retrieving a fundamental type from a Value
+  into a variable."""
+  return {
+      'string': 'GetAsString(%s)',
+      'boolean': 'GetAsBoolean(%s)',
+      'integer': 'GetAsInteger(%s)',
+      'double': 'GetAsDouble(%s)',
+  }[prop.json_type] % var