Initial code generation for features.

tools/json_schema_compiler/features_h_generator.py

Index: tools/json_schema_compiler/features_h_generator.py
diff --git a/tools/json_schema_compiler/features_h_generator.py b/tools/json_schema_compiler/features_h_generator.py
new file mode 100644
index 0000000000000000000000000000000000000000..309af6da7ab2a21dec027859bbedf8f9b7e4de8f
--- /dev/null
+++ b/tools/json_schema_compiler/features_h_generator.py
@@ -0,0 +1,72 @@
+# Copyright (c) 2013 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.
+
+import os.path
+
+from code import Code
+import cpp_util
+
+
+class HGenerator(object):
+  def Generate(self, permission_defs, source_file):
+    return _Generator(permission_defs, source_file).Generate()
+
+
+class _Generator(object):
+  """A .cc generator for PermissionFeatures.
+  """
+  def __init__(self, permission_defs, source_file):
+    self._feature_defs = cpp_util.RemoveFeatureDuplicates(permission_defs)

[not at google - send to devlin, 2013/09/12 16:20:43]

why are there duplicates?

|features| is a simpler name

[dhnishi (use Chromium), 2013/09/13 17:36:42]

The same feature may be defined multiple times for different channels. When the
permission features are read in, there are two "Audio" definitions, for example.

|permission_defs| renamed to |features|.

[not at google - send to devlin, 2013/09/13 21:37:51]

Ah right.

So that's actually something that we need to support. Those are the
"ComplexFeatures". A list of dicts isn't actually a set of different Features,
it's a list of different configurations that single feature can have.

So what you really need to do I think is update the Feature model to allow this.

+    self._source_file = source_file
+    self._source_file_filename = os.path.splitext(source_file)[0]
+
+  def Generate(self):
+    """Generates a Code object for PermissionFeatures.
+    """
+    c = Code()
+    (c.Append(cpp_util.CHROMIUM_LICENSE)
+      .Append()
+      .Append(cpp_util.GENERATED_FEATURE_MESSAGE % self._source_file)
+      .Append()
+    )
+    ifndef_name = cpp_util.GenerateIfndefName(self._source_file_filename,
+                                              "PermissionFeatures")
+    (c.Append('#ifndef %s' % ifndef_name)
+      .Append('#define %s' % ifndef_name)
+      .Append()
+    )
+
+    (c.Append('class PermissionFeatures {')
+      .Sblock(None, 1)
+      .Append('public:')
+      .Sblock(None, 1)

[not at google - send to devlin, 2013/09/12 16:20:43]

rather than making changes to code.py and doing, this, do just

(c.Append('class PermissionFeatures {')
  .Append(' public:')
  .Cblock(self._GenerateBody()))

and about the self._GenerateBody() - it's nicer to read these Code blocks when
composed together. So write a GenerateBody method which returns a Code.

[dhnishi (use Chromium), 2013/09/13 17:36:42]

Done.

+    )
+
+    # Generate the ID enum.
+    (c.Append('// Replaces APIPermission::ID')

[not at google - send to devlin, 2013/09/12 16:20:43]

these comments were to you, I didn't mean to generate them as well

[dhnishi (use Chromium), 2013/09/13 17:36:42]

Whoops, haha. Removed.

+      .Append('enum ID {')
+      .Sblock()
+      .Append('kUnknown,')
+    )
+    for feature in self._feature_defs:
+      c.Append('%s,' % feature.constant_name)
+    (c.Append('kEnumBoundary')
+      .Eblock()
+      .Append('};')
+      .Append()

[not at google - send to devlin, 2013/09/12 16:20:43]

likewise, pull the enum list generation into another method and do like

(c.Append('enum ID {')
  .Cblock(self._GenerateEnumConstants(self._feature_defs))
  .Eblock('}')
)

dunno, something like that. Can't remember which of the Block things you need.

[dhnishi (use Chromium), 2013/09/13 17:36:42]

Done.

+    )
+
+    # Generate the ToString function.
+    c.Append('static std::string ToString(ID id);')

[not at google - send to devlin, 2013/09/12 16:20:43]

return const char* from these methods.

[dhnishi (use Chromium), 2013/09/13 17:36:42]

Done.

+
+    # Generate the FromString function.
+    c.Append('static ID FromString(const std::string& id);')
+
+    (c.Eblock(None, 1)  # public
+      .Eblock(None, 1)  # class PermissionFeatures

[not at google - send to devlin, 2013/09/12 16:20:43]

don't think you need these to be so complicated

[dhnishi (use Chromium), 2013/09/13 17:36:42]

Removed the EBlock change.

Done.

+      .Append('};')
+      .Append('#endif  // %s' % ifndef_name)
+      .Append()
+    )
+    return c