[cmake-developers] How to handle dependencies of protobuf files ?

[Alexander Neundorf]

Any comments ?

Alex

On 2018 M05 15, Tue 21:45:06 CEST Alexander Neundorf wrote:
> Hi,
> 
> I stumbled upon a problem with protobuf files, I attached a testcase.
> There is a MyBase.proto, which is "imported" by Complex.proto.
> If MyBase.proto is modified, protoc is run again in MyBase.proto, but not on
> Complex.proto, although it should.
> You can have a look at the attached example.
> 
> The message MyData (in Complex.proto) has a member MyBase b1.
> If I rename the message MyBase (in MyBase.proto) e.g. to MyBaseXYZ, then the
> build fails, because Complex.pb.h was not regenerated, so it still refered
> to the now not existing class MyBase.
> 
> Is there already a solution to handle this ?
> 
> I think to do it properly, there would have to be a dependency scanning for
> proto files like there is for C/C++ headers.
> Parsing at the proto-files at cmake time wouldn't be good enough (since
> editing a proto file doesn't trigger a cmake run).
> 
> Comments ?
> 
> Alex