Changes to the code generation

[Christofer Dutz <ch...@c-ware.de>]

Hi all,

the last few days and especially during the weekend I worked hard on the freemarker based code generation.
After making the code-generation a lot better for C I extracted common code into a new BaseFreemarkerLanguageTemplateHelper class which is now the base of the Java and the C code generation helper. It generally contains methods for type, checks and generic operations (Like listing up the names of all types referenced in a given definition … It resolves the types of expressions etc.)

I completely overworked the discriminator code … you can now use as many discriminator fields as you like. And you no longer need to use these strange discriminatorValuex[0] expressions, which you actually have no reference to where they come from. Now everything is typesafe and should be a lot cleaner.

As an example the S7 mspec changed from:

[discriminatedType 'S7Payload' [uint 8 'messageType', S7Parameter 'parameter']
    [typeSwitch 'parameter.discriminatorValues[0]', 'messageType'
        ['0x04','0x03' S7PayloadReadVarResponse
            [array S7VarPayloadDataItem 'items' count 'CAST(parameter, S7ParameterReadVarResponse).numItems' ['lastItem']]
        ]
        ['0x05','0x01' S7PayloadWriteVarRequest
            [array S7VarPayloadDataItem 'items' count 'COUNT(CAST(parameter, S7ParameterWriteVarRequest).items)' ['lastItem']]
        ]
        ['0x05','0x03' S7PayloadWriteVarResponse
            [array S7VarPayloadStatusItem 'items' count 'CAST(parameter, S7ParameterWriteVarResponse).numItems']
        ]
        ['0x00','0x07' S7PayloadUserData
            [array S7PayloadUserDataItem 'items' count 'COUNT(CAST(parameter, S7ParameterUserData).items)' ['CAST(CAST(parameter, S7ParameterUserData).items[0], S7ParameterUserDataItemCPUFunctions).cpuFunctionType']]
        ]
    ]
]

To:


[discriminatedType 'S7Payload' [uint 8 'messageType', S7Parameter 'parameter']
    [typeSwitch 'parameter.parameterType', 'messageType'
        ['0x04','0x03' S7PayloadReadVarResponse
            [array S7VarPayloadDataItem 'items' count 'CAST(parameter, S7ParameterReadVarResponse).numItems' ['lastItem']]
        ]
        ['0x05','0x01' S7PayloadWriteVarRequest
            [array S7VarPayloadDataItem 'items' count 'COUNT(CAST(parameter, S7ParameterWriteVarRequest).items)' ['lastItem']]
        ]
        ['0x05','0x03' S7PayloadWriteVarResponse
            [array S7VarPayloadStatusItem 'items' count 'CAST(parameter, S7ParameterWriteVarResponse).numItems']
        ]
        ['0x00','0x07' S7PayloadUserData
            [array S7PayloadUserDataItem 'items' count 'COUNT(CAST(parameter, S7ParameterUserData).items)' ['CAST(CAST(parameter, S7ParameterUserData).items[0], S7ParameterUserDataItemCPUFunctions).cpuFunctionType']]
        ]
    ]
]

Which is quite a bit more intuitive, I think.

Also I had to extend the code generation plugin a bit … so we need to re-release that before we’re able to release something that contains my current changes.

As the changes also affect mspec files, I would really like to merge things from my current “feature/c-code-generation-tagged-unions” back to develop.

Feedback greatly appreciated.

Chris