Code-generator for C/C++-Structs based on CASTXML gccxml-output

In the case existing C-Structs are used in a project, the need occurs to have compare-operators, toString-functions and maybe the occasional json-serializer and json-deserializer function.

Since a C-Struct has a well-defined structure, the CastXML-tool can be used to generate a C-family abstract syntax tree XML-representation of the struct. This XML-representation can then be transformed by using the GSL-language.

Purpose

• Minimal to no code-changes in existing code
• Analyze C / C++ -Structs
• Generate XML-representation with the CastXML-tool
• Transform XML to C++-code

Dependencies

• gsl
• castxml
• jsonxx

What is implemented?

Since the gccxml-syntax is well structured, the following entities are analyzed/handled:

• FundamentalTypes

  • uint8_t, 16,32,64
  • int8_t, 16,32,64
  • float, double
  • Typedefs to FundamentalTypes
  • std::vector, std::list, std::pair
  • std::map<K,V>
    • K,V must either be a FundamentalType, or a predefined Struct
    • ** std::map << K , std::vector|list|pair >> is not supported for now **

• Enumerations

• Old style C++

• New style C11 (not yet supported)

• Typedefs

  • Mostly tested typedef to Struct,FundamentalType

• Unions

  • Following assumption is made: The classifier of which union-Choice is to be used is conditioned by a previously defined Field ( in the same Struct).
  • By stipulating the condition for which this Union-Choice is valid in a seperate xyz.settings.xml file, we can generate the needed printers (toString, streaming) and json-serializer and json-deserializer code.

• std::list, std::vector

  • Are represented as Class-entities, and for these cases the generator is working.

• std::pair is converted by C++ into a Struct with first- and second-members.

Examples

• See the examples-directory for use cases.

Author

• Fabian N.C. van 't Hooft

Notes / Limitations

• The generator was conceived to run once under the control of the programmer.
• Other then jsonxx, there are no special requirements and the generated code should run, and is running on very limited hardware such as mk6800 etc.
• a precompiled castxml-utility can be downloaded directly from ITK by following these instructions.

Special thanks

• All the authors of the dependencies, gsl, castxml and jsonxx.

• Inspired by: cjson

• pygccxml

  • This library can also read the gccxml-output, but needs a python-infrastructure.

Open Issues / Todos

• Add comments in generated artifacts
• Cleanup test-includes for gtest
• Add sha1sum of input-file in generated artifacts
• Add better float comparison handling (floating-point according to IEEE754 standard)
• Tests ( json ser, json deser )
• Add Examples for meta-data injection ( structs, compare functions, union-serialization )
• Add Tests for meta-data injection ( structs, compare functions, union-serialization )