Question

I’ve added a custom build step to my Visual Studio project files which generates the google protobuf .h/.cc files from the .proto input files. But I’ve been wondering if it’s possible to start a compile only if the content of the proto files has changed?

Is there a way to tell VisualStudio from a custom build step exactly that? What is the optimal way to integrate proto files into a visual studio build solution?

At the moment, at every build the .proto file is updated which then also updates the time stamp of the output .h/.cc files …which then issues a recompile of everything dependent from that. Is there a better way around it, while still building them directly from visual studio?

Answer 1

Maybe this helps. Especially look at the post of Igor Zavoychinskiy:

Solution of this nasty problem is actually simple: in outputs sections
you should specify full path(s). This isn’t explicitly stated anywhere
but without this checker just fails to find the files and, hence,
assumes they don’t exist. For example for protobuffers compiling
outputs section will be like this:

$(InputDir)\$(InputName).pb.cc;$(InputDir)\$(InputName).pb.h

and (maybe?) kmote00:

…
Bottom line: I just had to make sure my “Outputs” entry exactly
matched the Default Value in the (user-defined) “OutputFile” property.
(Thankfully this also obviated the need for a two-pass build, which
was another annoyance I had previously put up with.)