Bindings are created manually. This is mostly fine and intended.
However, there is one place where we would like to use code generation instead. C library defines quite a lot of enums, and these enums are replicated one-to-one in bindings.
It would be nice to implement a script that automatically parses enums in C library and generates corresponding Go and Java files.
The easiest way to parse C declarations is to run doxygen build, which will produce XML file with all C API declarations. Then we can find enum declarations in that file.
After building documentation, as described here, Doxygen-generated XML files will be located in build/docs/public_api/xml.
For example, there is roc_format enum with ROC_FORMAT_PCM_FLOAT32 value, and here is corresponding nodes in XML:
<memberdef kind="enum" id="config_8h_1ac24a6637fefa48d61bb8631c25bde919" prot="public" static="n o" strong="no">
<type></type>
<name>roc_format</name>
<enumvalue id="config_8h_1ac24a6637fefa48d61bb8631c25bde919aa851fa1a679b2df37b113fefe53b98e1" prot="public">
<name>ROC_FORMAT_PCM_FLOAT32</name>
<initializer>= 1</initializer>
<briefdescription>
<para>PCM floats. </para>
</briefdescription>
<detaileddescription>
<para>Uncompressed samples coded as 32-bit native-endian floats in range [-1; 1]. Channels are interle aved, e.g. two channels are encoded as "L R L R ...". </para>
</detaileddescription>
</enumvalue>
In go, all enums are currently in same file (config.go), and in java, each enum is in its own file. Currently they're updated manually. And now we want to replace this hand-written definitions with generated code.
Generator should produce something similar to what exists currently. It should:
follow same naming conventions (e.g. snake_case it converted to CamelCase for enum names),
preserve enum values equal to value in C library
preserve comments
Since one class per file is preferred for Java, for simplicity we can use same approach for Go as well.
We should keep in mind that in future more bindings may be added, and it should be feasible to extend generator to support more output languages.
We have a C library and Go and Java bindings for it.
Bindings are created manually. This is mostly fine and intended.
However, there is one place where we would like to use code generation instead. C library defines quite a lot of enums, and these enums are replicated one-to-one in bindings.
It would be nice to implement a script that automatically parses enums in C library and generates corresponding Go and Java files.
The easiest way to parse C declarations is to run doxygen build, which will produce XML file with all C API declarations. Then we can find enum declarations in that file.
Enums are declared in these headers:
After building documentation, as described here, Doxygen-generated XML files will be located in
build/docs/public_api/xml.For example, there is
roc_formatenum withROC_FORMAT_PCM_FLOAT32value, and here is corresponding nodes in XML:And here is what we should generate (kind of):
In go, all enums are currently in same file (
config.go), and in java, each enum is in its own file. Currently they're updated manually. And now we want to replace this hand-written definitions with generated code.Generator should produce something similar to what exists currently. It should:
Since one class per file is preferred for Java, for simplicity we can use same approach for Go as well.
We should keep in mind that in future more bindings may be added, and it should be feasible to extend generator to support more output languages.
We use Python for scripting, so let's use it for generator as well. The script should be added here: https://github.com/roc-streaming/roc-toolkit/tree/develop/scripts
We'll need 3 pull requests:
roc-toolkitrepo that adds generator scriptroc-goandroc-javarepos that replace hand-written enum declarations with generated