Add a codegen builder

[danburkert]

There are expected to be a few more optional features in the future: map type, service generator, zero copy, etc.

[valarauca]

I'm just passing by to 👍 this issue.

I'm using ProtoBufs in a Rust project for work and we currently have a monorepo that holds all our protobuffers (and a very long 200+ LoC Makefile) to build them I've spent a few hours to integrate this tool this morning and exposing a way to pass args to --proto_path is desperately needed via the build.rs file.

[danburkert]

@valarauca That's already possible, have you seen the docs in https://github.com/danburkert/prost/tree/master/prost-build README? prost_build::compile_protos's second argument is the include paths. Note that the protobuf builtin .protos are already included (the well known types stuff).

[valarauca]

I'm really not sure I understand (or I misstated my issue).

I'm attempting to retrofit prost into our my companies existing structure without breaking anything.

Structure example:

proto/
----Makefile
----build.gradle
----Gopkg.toml
----Gopkg.lock
-----team/
---------team.proto
-----another_team/
---------name1.proto
---------name2.proto

So this becomes

proto/
----Cargo.toml
----build.rs
----Makefile
----build.gradle
----Gopkg.toml
----Gopkg.lock
-----src/
---------lib.rs
---------item.rs #Hopefuly
-----team/
---------team.proto
-----another_team/
---------name1.proto
---------name2.proto

If I just do something like prost_build::compile_protos(&["agent/agent.proto"], &[], None).unwrap()

This fails as agent.proto's package is agent.proto So I should do prost_build::compile_protos(&[], &["agent/agent.proto"], None).unwrap()?

---

I will try this but currently I cannot build prost requires bytes = "0.1.2" which requires nightly? I see 0.4 is called out, but 0.1.2 is always fetched by cargo. I attempted to fully purge my ~/.cargo/registry

---

I've attempted to rm -rf ~/.cargo/register and cargo update ref neither solves the bytes = "0.1.2" requirement. It ends up being the second crate that is fetched.

[danburkert]

Yes, this is currently supported. The first arg to compile_protos is the list of .protos you want to compile (you can skip any that are transitively imported, you only have to include the 'root' .protos). The second arg is the include paths. What the include paths should be depends on what the package declaration in the protobufs is, but assuming that's package team; and package another_team;, and we're compiling from the first source tree above, I think you want:

prost_build::compile_protos(&["src/team/team.proto"], &["src/"], None).unwrap()

[valarauca]

Awesome. Any clue what's up with the bytes v0.1.2 being imported?

My first attempt it didn't happen, but on the 2nd, 3rd, and 4th it crashed and burned. Currently I can't even build anything that requires prost.

[danburkert]

hmm, no. My usual route for debugging issues like that is to inspect Cargo.lock and figure out where they are coming from. prost and prost-build have a dependency on 0.4, so it shouldn't be pulling in 0.1.

[valarauca]

Interesting.

I'll throw this in queue.

[danburkert]

A code generator config has been added in 17474e8. @valarauca if you're still having build issues feel free to open another issue.