API review

Proposer: Mirza

Present at review:

• Tully
• William
• Dirk
• Mirza

Question / concerns / comments

Issue in c++ name mangling is not standard across compilers

4 options:

Just open and call known methods in a library

No way to easily introspect a library

Need 1 well known function

• uses extern c to avoid mangling, poco_build_manifest()
• Poco poco_build_manifest inserts factories for each class registered by a macro system. connecting class name to factory.
• two other libraries do the same thing.
• this require macros declared in one place, standard practice is to put all macros in a single file

current implementation

• Poco named manifests
  • poco_build_manifest_FOO
  • need the name from the xml files in the manifest

Ioan's approach

• Create a proxy class
  • library links against it
  • contains registry of plugins
• In your cpp file you call your macro, the macro creates a constructor, which registers it with the proxy library
• a static global variable is instantiated to force loading
• Issues:
  • cleaning up on unload
  • do we do one proxy for all plugins
    • aggregate at pluginlib
• want to avoid symbol visibility to protect from unload failures
• possibly a header only implementation

Meeting agenda

To be filled out by proposer based on comments gathered during API review period

Conclusion

• We're going to try to continue with Ioan's approach.

• {x} Might be able to keep API compatiability for pluginlib MACROS, might deprecate one of the arguments as it's now unnecessary. Provides easy migration.

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