Generate code for encoding cloud policy protobufs

components/policy/tools/generate_policy_source.py

Index: components/policy/tools/generate_policy_source.py
diff --git a/components/policy/tools/generate_policy_source.py b/components/policy/tools/generate_policy_source.py
index 889038aa97b71d57f4005fe85977998c8b133d27..7f2843f34205885e2c9c758cdbbe1f51f4ebd1b3 100755
--- a/components/policy/tools/generate_policy_source.py
+++ b/components/policy/tools/generate_policy_source.py
@@ -203,6 +203,16 @@ def main():
                     dest='risk_header_path',
                     help='generate header file for policy risk tags',
                     metavar='FILE')
+  parser.add_option('--crospch', '--cros-policy-constants-header',
+                    dest='cros_constants_header_path',
+                    help='generate header file of policy constants for use in '
+                         'Chrome OS',
+                    metavar='FILE')
+  parser.add_option('--crospcc', '--cros-policy-constants-source',
+                    dest='cros_constants_source_path',
+                    help='generate source file of policy constants for use in '
+                         'Chrome OS',
+                    metavar='FILE')
   (opts, args) = parser.parse_args()
 
   if len(args) != 4:
@@ -251,6 +261,14 @@ def main():
   if os == 'android' and opts.app_restrictions_path:
     GenerateFile(opts.app_restrictions_path, _WriteAppRestrictions, xml=True)
 
+  # Generated code for Chrome OS (unused in Chromium).
+  if opts.cros_constants_header_path:
+    GenerateFile(opts.cros_constants_header_path,
+        _WriteChromeOSPolicyConstantsHeader, sorted=True)
+  if opts.cros_constants_source_path:
+    GenerateFile(opts.cros_constants_source_path,
+        _WriteChromeOSPolicyConstantsSource, sorted=True)
+
   return 0
 
 
@@ -1098,7 +1116,7 @@ def _WriteCloudPolicyFullRuntimeProtobuf(policies, os, f, riskTags):
 
 #------------------ protobuf decoder -------------------------------#
 
-CPP_HEAD = '''
+POLICY_DECODER_CPP_HEAD = '''

[emaxx, 2017/03/02 16:56:15]

nit: Add word "CLOUD" into the constant names here and in line 1183 (for
consistency with
_WriteCloudPolicyDecoder)?

[ljusten (tachyonic), 2017/03/16 23:45:27]

Done.

 #include <limits>
 #include <memory>
 #include <utility>
@@ -1162,7 +1180,7 @@ void DecodePolicy(const em::CloudPolicySettings& policy,
 '''
 
 
-CPP_FOOT = '''}
+POLICY_DECODER_CPP_FOOT = '''}
 
 }  // namespace policy
 '''
@@ -1189,7 +1207,7 @@ def _CreateExternalDataFetcher(type, name):
   return 'nullptr'
 
 
-def _WritePolicyCode(f, policy):
+def _WritePolicyDecoderCode(f, policy):

[emaxx, 2017/03/02 16:56:15]

nit: Add word "Cloud" into the function name (for consistency with
_WriteCloudPolicyDecoder)?

[ljusten (tachyonic), 2017/03/16 23:45:27]

Done.

   membername = policy.name.lower()
   proto_type = '%sPolicyProto' % policy.policy_protobuf_type
   f.write('  if (policy.has_%s()) {\n' % membername)
@@ -1235,12 +1253,115 @@ def _WritePolicyCode(f, policy):
 
 
 def _WriteCloudPolicyDecoder(policies, os, f, riskTags):
-  f.write(CPP_HEAD)
+  f.write(POLICY_DECODER_CPP_HEAD)
   for policy in policies:
     if policy.is_supported and not policy.is_device_only:
-      _WritePolicyCode(f, policy)
-  f.write(CPP_FOOT)
+      _WritePolicyDecoderCode(f, policy)
+  f.write(POLICY_DECODER_CPP_FOOT)
+
+
+#------------------ Chrome OS policy constants header ------------------------#

[emaxx, 2017/03/02 16:56:15]

nit: Could you please reformat this bar and the other comment bars in the file
to the same length? (Most of them are 69 characters long - for some reason :) )

[ljusten (tachyonic), 2017/03/16 23:45:27]

Done.

+
+# Returns a list of supported user policies by filtering |policies|.
+def _GetSupportedUserPolicies(policies):
+  return filter(lambda policy: policy.is_supported and \

[emaxx, 2017/03/02 16:56:15]

nit: Backslash is not required.

[ljusten (tachyonic), 2017/03/16 23:45:27]

Done.

+                               not policy.is_device_only, policies)
+
+
+# Returns the set of all policy.policy_protobuf_type strings from |policies|.
+def _GetProtobufTypes(policies):
+  protobuf_types = set()

[emaxx, 2017/03/02 16:56:15]

nit: Maybe simply:
return set(policy.policy_protobuf_type for policy in policies)

[ljusten (tachyonic), 2017/03/16 23:45:27]

Done.

+  for policy in policies:
+    protobuf_types.add(policy.policy_protobuf_type)
+  return protobuf_types
+
+
+# Writes the definition of an array that contains the pointers to the mutable
+# proto field for each policy in |policies| of the given |protobuf_type|.
+def _WriteChromeOSPolicyAccessHeader(f, protobuf_type):
+  f.write('// Access to the mutable protobuf function of all supported '
+          '%s user\n// policies.\n' % protobuf_type.lower())
+  f.write('struct %sPolicyAccess {\n'
+          '  const char* policy_key;\n'
+          '  enterprise_management::%sPolicyProto*\n'
+          '      (enterprise_management::CloudPolicySettings::'
+          '*mutable_proto_ptr)();\n'
+          '};\n' % (protobuf_type, protobuf_type))
+  f.write('extern const %sPolicyAccess k%sPolicyAccess[];\n\n'
+          % (protobuf_type, protobuf_type))
+
+
+# Writes policy_constants.h for use in Chrome OS.
+def _WriteChromeOSPolicyConstantsHeader(policies, os, f, riskTags):

[emaxx, 2017/03/02 16:56:15]

nit: s/riskTags/risk_tags/ according to style guide (across the whole file?)

[ljusten (tachyonic), 2017/03/16 23:45:27]

Done.

+  f.write('#ifndef __BINDINGS_POLICY_CONSTANTS_H_\n'
+          '#define __BINDINGS_POLICY_CONSTANTS_H_\n\n')
+
+  # Forward declarations.
+  supported_user_policies = _GetSupportedUserPolicies(policies)
+  protobuf_types = _GetProtobufTypes(supported_user_policies)
+  f.write('namespace enterprise_management {\n'
+          'class CloudPolicySettings;\n')
+  for protobuf_type in protobuf_types:
+    f.write('class %sPolicyProto;\n' % protobuf_type)
+  f.write('}  // namespace enterprise_management\n\n')
+
+  f.write('namespace policy {\n\n')
+
+  # Policy keys.
+  f.write('// Registry key names for user and device policies.\n'
+          'namespace key {\n\n')
+  for policy in policies:
+    f.write('extern const char k' + policy.name + '[];\n')
+  f.write('\n}  // namespace key\n\n')
+
+  # User policy proto pointers, one struct for each protobuf type.
+  for protobuf_type in protobuf_types:
+    _WriteChromeOSPolicyAccessHeader(f, protobuf_type)
+
+  f.write('}  // namespace policy\n\n'
+          '#endif  // __BINDINGS_POLICY_CONSTANTS_H_\n')
+
+
+#------------------ Chrome OS policy constants source ------------------------#
+
+# Writes an array that contains the pointers to the mutable proto field for each
+# policy in |policies| of the given |protobuf_type|.
+def _WriteChromeOSPolicyAccessSource(policies, f, protobuf_type):
+  f.write('constexpr %sPolicyAccess k%sPolicyAccess[] = {\n'
+          % (protobuf_type, protobuf_type))
+  for policy in policies:
+    if policy.policy_protobuf_type == protobuf_type:
+      f.write('  {key::k%s,\n'
+              '   &em::CloudPolicySettings::mutable_%s},\n'
+              % (policy.name, policy.name.lower()))
+  # The list is nullptr-terminated.
+  f.write('  {nullptr, nullptr},\n'
+          '};\n\n')
+
+
+# Writes policy_constants.cc for use in Chrome OS.
+def _WriteChromeOSPolicyConstantsSource(policies, os, f, riskTags):
+  f.write('#include "bindings/cloud_policy.pb.h"\n'
+          '#include "bindings/policy_constants.h"\n\n'
+          'namespace em = enterprise_management;\n\n'
+          'namespace policy {\n\n')
+
+  # Policy keys.
+  f.write('namespace key {\n\n')
+  for policy in policies:
+    f.write('const char k{name}[] = "{name}";\n'.format(name=policy.name))
+  f.write('\n}  // namespace key\n\n')
+
+  # User policy proto pointers, one struct for each protobuf type.
+  supported_user_policies = _GetSupportedUserPolicies(policies)
+  protobuf_types = _GetProtobufTypes(supported_user_policies)
+  for protobuf_type in protobuf_types:
+    _WriteChromeOSPolicyAccessSource(supported_user_policies, f, protobuf_type)
+
+  f.write('}  // namespace policy\n')
+
 
+#------------------ app restrictions -------------------------------#
 
 def _WriteAppRestrictions(policies, os, f, riskTags):