From 5e6685c6896dd66e3a96f6d3b8243aee3a563372 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Sat, 1 May 2021 12:17:21 +0200 Subject: feat(cheddar): Add a build script that injects BAT_SYNTAXES The BAT_SYNTAXES environment variable is injected during Nix builds and points to the build result of //third_party/bat_syntaxes, which is included in the cheddar binary. During development this is a bit annoying: Opening a Nix shell will set the right variable, but it will also mess with the Cargo environment in ways that make it annoying to use (*and* require a pre-build of all dependencies as required by naersk). For an easier development flow, this adds a build script that automatically runs Nix, fetches the path to the syntax set and sets the environment variable. It is a no-op if the variable is already set. This makes for a smoother development experience when working on cheddar in a depot checkout. Change-Id: Ib5435518897e3443247edd9f362821c0b9ff756b Reviewed-on: https://cl.tvl.fyi/c/depot/+/3081 Tested-by: BuildkiteCI Reviewed-by: flokli --- tools/cheddar/build.rs | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 tools/cheddar/build.rs diff --git a/tools/cheddar/build.rs b/tools/cheddar/build.rs new file mode 100644 index 0000000000..c04209d6a4 --- /dev/null +++ b/tools/cheddar/build.rs @@ -0,0 +1,50 @@ +//! Build script that can be used outside of Nix builds to inject the +//! BAT_SYNTAXES variable when building in development mode. +//! +//! Note that this script assumes that cheddar is in a checkout of the +//! TVL depot. + +use std::process::Command; + +static BAT_SYNTAXES: &str = "BAT_SYNTAXES"; +static ERROR_MESSAGE: &str = r#"Failed to build syntax set. + +When building during development, cheddar expects to be in a checkout +of the TVL depot. This is required to automatically build the syntax +highlighting files that are needed at compile time. + +As cheddar can not automatically detect the location of the syntax +files, you must set the `BAT_SYNTAXES` environment variable to the +right path. + +The expected syntax files are at //third_party/bat_syntaxes in the +depot."#; + +fn main() { + // Do nothing if the variable is already set (e.g. via Nix) + if let Ok(_) = std::env::var(BAT_SYNTAXES) { + return; + } + + // Otherwise ask Nix to build it and inject the result. + let output = Command::new("nix-build") + .arg("-A").arg("third_party.bat_syntaxes") + // ... assuming cheddar is at //tools/cheddar ... + .arg("../..") + .output() + .expect(ERROR_MESSAGE); + + if !output.status.success() { + eprintln!("{}\nNix output: {}", ERROR_MESSAGE, String::from_utf8_lossy(&output.stderr)); + return; + } + + let out_path = String::from_utf8(output.stdout) + .expect("Nix returned invalid output after building syntax set"); + + // Return an instruction to Cargo that will set the environment + // variale during rustc calls. + // + // https://doc.rust-lang.org/cargo/reference/build-scripts.html#cargorustc-envvarvalue + println!("cargo:rustc-env={}={}", BAT_SYNTAXES, out_path.trim()); +} -- cgit 1.4.1