Pepper: Simplify idl_thunk implementation.

ppapi/generators/idl_thunk.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 """ Generator for C++ style thunks """
 
 import glob
 import os
 import re
@@ skipping 261 matching lines @@
     version = node.GetVersion(release).replace('.', '_')
     function_name += version
 
   invocation = 'enter.%s()->%s(%s)' % (function_container,
                                        function_name,
                                        call_arglist)
 
   handle_errors = not (member.GetProperty('report_errors') == 'False')
   out_params = _GetOutputParams(member, release)
   if is_callback_func:
-    # TODO(teravest): Reduce code duplication below.
     body = '%s\n' % _MakeEnterLine(filenode, node, member, args[0],
                                    handle_errors, args[len(args) - 1][1], meta)
-    value = member.GetProperty('on_failure')
-    if value is None:
-      value = 'enter.retval()'
-    if member.GetProperty('always_set_output_parameters'):
-      body += 'if (enter.failed()) {\n'
-      for param in out_params:
-        body += '  memset(%s, 0, sizeof(*%s));\n' % (param, param)
-      body += '  return %s;\n' % value
-      body += '}\n'
-      body += 'return enter.SetResult(%s);' % invocation
-      meta.AddBuiltinInclude('string.h')
-    else:
-      body += 'if (enter.failed())\n'
-      body += '  return %s;\n' % value
-      body += 'return enter.SetResult(%s);' % invocation
+    failure_value = member.GetProperty('on_failure')
+    if failure_value is None:
+      failure_value = 'enter.retval()'
+    failure_return = 'return %s;' % failure_value
+    success_return = 'return enter.SetResult(%s);' % invocation
   elif rtype == 'void':
     body = '%s\n' % _MakeEnterLine(filenode, node, member, args[0],
                                    handle_errors, None, meta)
-    if member.GetProperty('always_set_output_parameters'):
-      body += 'if (enter.succeeded()) {\n'
-      body += '  %s;\n' % invocation
-      body += '  return;\n'
-      body += '}'
-      for param in out_params:
-        body += '\nmemset(%s, 0, sizeof(*%s));' % (param, param)
-      meta.AddBuiltinInclude('string.h')
-    else:
-      body += 'if (enter.succeeded())\n'
-      body += '  %s;' % invocation
-
+    failure_return = 'return;'
+    success_return = '%s;' % invocation  # We don't return anything for void.
   else:
-    value = member.GetProperty('on_failure')
-    if value is None:
-      value = _GetDefaultFailureValue(rtype)
-    if value is None:
-      raise TGenError('No default value for rtype %s' % rtype)
-
     body = '%s\n' % _MakeEnterLine(filenode, node, member, args[0],
                                    handle_errors, None, meta)
-    if member.GetProperty('always_set_output_parameters'):
-      body += 'if (enter.failed()) {\n'
-      for param in out_params:
-        body += '  memset(%s, 0, sizeof(*%s));\n' % (param, param)
-      body += '  return %s;\n' % value
-      body += '}\n'
-      body += 'return %s;' % invocation
-      meta.AddBuiltinInclude('string.h')
-    else:
-      body += 'if (enter.failed())\n'
-      body += '  return %s;\n' % value
-      body += 'return %s;' % invocation
+    failure_value = member.GetProperty('on_failure')
+    if failure_value is None:
+      failure_value = _GetDefaultFailureValue(rtype)
+    if failure_value is None:
+      raise TGenError('No default value for rtype %s' % rtype)

[dmichael (off chromium), 2013/04/18 15:41:15]

I know this is not a new line, but I think it would be nice to have a more
descriptive error message, to save time for anybody who hits it. Like...
"There is no default return value for type "%s". Maybe you should provide an
on_failure attribute in the IDL file?"

+    failure_return = 'return %s;' % failure_value
+    success_return = 'return %s;' % invocation
+
+  if member.GetProperty('always_set_output_parameters'):
+    body += 'if (enter.failed()) {\n'
+    for param in out_params:
+      body += '  memset(%s, 0, sizeof(*%s));\n' % (param, param)
+    body += '  %s\n' % failure_return
+    body += '}\n'
+    body += '%s' % success_return
+    meta.AddBuiltinInclude('string.h')
+  else:
+    body += 'if (enter.failed())\n'
+    body += '  %s\n' % failure_return
+    body += '%s' % success_return
   return body
 
 
 def DefineMember(filenode, node, member, release, include_version, meta):
   """Returns a definition for a member function of an interface.
 
   Args:
     filenode - IDLNode for the file
     node - IDLNode for the interface
     member - IDLNode for the member function
@@ skipping 223 matching lines @@
     print "Golden file for M13-M14 failed."
     failed = 1
   else:
     print "Golden file for M13-M14 passed."
 
   return failed
 
 
 if __name__ == '__main__':
   sys.exit(Main(sys.argv[1:]))