Remove UNSPECIFIED aliases for enums with natural zero values #493
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astarche
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astarche
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reckenro
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Found a few non-attribute enums that still had the allow_alias and UNSPECIFIED value due to the other 0 value not being directly after it:
- BT
- AcpResultsMeasurementStatus
- PacketType
- Instr
- Boolean
- LinearInterpolationFormat
- Personality
- SelfCalStep
- WLAN
- OfdmLtfSize
- OfdmModAccLSigParityCheckStatus
- OfdmModAccSigBCrcStatus
- OfdmModAccSigCrcStatus
- RFSG
- RoutedSignal
reckenro
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Jan 28, 2022
mgumble
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Jan 28, 2022
reckenro
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Feb 1, 2022
reckenro
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Co-authored-by: Ryan Eckenrode <[email protected]>
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What does this Pull Request accomplish?
Remove UNSPECIFIED aliases for enums with natural zero values
Fixes #444.
Why should this Pull Request be merged?
Enum aliases make it impossible to map protobuf data back to one-or-the-other specific alias. This specifically causes problems and/or confusion in replay/capture and other grpc-json use cases.
Normally the
UNSPECIFIEDzero-value enum is used as a convention to ensure that the default value of an enum is defined to be invalid/meaningless. This isn't effective when it is aliased to a meaningful zero value from the C API. Also, we use enums along withoneofs which are a different way of ensuring that a value is set. Ultimately, avoiding aliases is more useful than injecting a conventionalUNSPECIFIEDvalue that doesn't serve it's intended purpose.Alternatives Considered
Use mapped enum values to avoid valid zero values. The reason we have zero valued enums is because we're using the enum values from the C API, some of which have zero values. Mapped enums provide a way to avoid this. Reason Rejected: This would be massively API breaking for existing drivers and also deviate from the C API. We can consider offering a "mapped" alternative if there is some case where it is especially useful (consider attribute values, which have a lot of overlap), but we should stay-the-course of supporting an API that uses C enum values directly and that solution is sufficient for now.
Breaking change
This change Does not break binary compatibility.
It will break "source compatibility" for existing clients that intentionally use the
UNSPECIFIEDenum value for enums that have a value default value. Those clients will need to make some sort of edit after re-running protoc (Very rare. Either a bug or a test.).What testing has been done?
Ran all RF, Scope, Switch, DCPower, and DAQmx tests. One pre-existing failure.