Add a way to not use bindgen

[hug-dev]

Fix #489

Add the use-bindgen feature which is activated by default.

If disabled, then the previously generated bindings will be used instead of generating new ones. It will fail compilation if this feature is disabled for the non supported targets.

If enabled, the behaviour is the same as before.

[hug-dev]

hmm --no-default-features is used with targets that do not have pregenerated bindings... I can instead make a not-use-bindgen feature and reverse the logic everywhere?

[BusyJay]

How about using rust-lang/cargo#7914 to enable use-bindgen for unsupported targets?

[hug-dev]

How about using rust-lang/cargo#7914 to enable use-bindgen for unsupported targets?

That is a good idea but I think the cfg parameters can not filter on the target triple individually... So I don't think I can use that to enable bindgen on every target but Aarch64 and x86 on Linux.

I fixed the Mac CI workflow here by enabling the use-bindgen feature there.

I am aware though that this will break compilation for everyone using this crate with --no-default-features on unsupported platforms.

[BusyJay]

...the cfg parameters can not filter on the target triple individually...

How about:

[target.'cfg(not(all(any(target_arch="x86_64", target_arch="aarch64"), target_os="linux", target_env="gnu")))'.dependencies.grpcio-sys]
path = "grpc-sys"
version = "0.7"
features = ["use-bindgen"]

?

[hug-dev]

ooh yes I guess that would do it, nice 👌

With the following:

diff --git a/Cargo.toml b/Cargo.toml
index 70b1b39..a02033d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -17,7 +17,7 @@ autoexamples = false
 all-features = true

 [dependencies]
-grpcio-sys = { path = "grpc-sys", version = "0.7", default-features = false }
+grpcio-sys = { path = "grpc-sys", version = "0.7" }
 libc = "0.2"
 futures = "0.3"
 protobuf = { version = "2.0", optional = true }
@@ -30,7 +30,7 @@ parking_lot = "0.11"
 members = ["proto", "benchmark", "compiler", "interop", "tests-and-examples"]

 [features]
-default = ["protobuf-codec", "secure", "use-bindgen"]
+default = ["protobuf-codec", "secure"]
 protobuf-codec = ["protobuf"]
 prost-codec = ["prost", "bytes"]
 secure = ["grpcio-sys/secure"]
@@ -47,3 +47,6 @@ travis-ci = { repository = "tikv/grpc-rs" }

 [patch.crates-io]
 grpcio-compiler = { path = "compiler", version = "0.7.0", default-features = false }
+
+[target.'cfg(not(all(any(target_arch="x86_64", target_arch="aarch64"), target_os="linux", target_env="gnu")))'.dependencies]
+grpcio-sys = { path = "grpc-sys", version = "0.7", features = ["use-bindgen"] }
diff --git a/grpc-sys/Cargo.toml b/grpc-sys/Cargo.toml
index 60e1d2f..c02f7eb 100644
--- a/grpc-sys/Cargo.toml
+++ b/grpc-sys/Cargo.toml
@@ -53,7 +53,6 @@ openssl-sys = { version = "0.9", optional = true, features = ["vendored"] }
 libz-sys = { version = "1.0.25", features = ["static"] }

 [features]
-default = ["use-bindgen"]
 secure = []
 openssl = ["secure"]
 openssl-vendored = ["openssl", "openssl-sys"]

compiling with cargo build -Z features=itarget with nightly rust, the use-bindgen feature is not enabled on my machine (x86 linux gnu). I can enable it adding --features use-bindgen.

I guess that would do it but the main problem I see is that this requires a nightly toolchain to work... For my use-case ideally stable would be used.

[BusyJay]

Got it. I guess this can only be brought to 0.8.0.

[hug-dev]

Hello @BusyJay !

Do you know when 0.8.0 is planned to be released? We would be happy to use the change of this PR 😃

[hug-dev]

Hello @BusyJay

Kindly pinging you again to know about plans for a next release 👌

[BusyJay]

Hi, @hug-dev, we are working on #506, when it's merged we may release next version.

[hug-dev]

Excellent! Sorry for the spam 😋

[hug-dev]

Thanks for the release 👌