misc: add build.rs

build.rs

@@ -0,0 +1,48 @@
+use std::env;
+use std::fs;
+use std::path::{Path, PathBuf};
+use std::process::Command;
+
+static PIXI_TRAMPOLINE: &str = "pixi_trampoline";
+static TRAMPOLINES_FOLDER: &str = "trampolines";
+
+fn main() {
+    // Construct trampoline crate path
+    let manifest_dir = env!("CARGO_MANIFEST_DIR");
+    let trampoline_crate_path = format!("{}/crates/{}", manifest_dir, PIXI_TRAMPOLINE);
+    let trampoline_crate = Path::new(&trampoline_crate_path);
+    let trampolines_dir = trampoline_crate.join(TRAMPOLINES_FOLDER);
+
+    // Get the target triplet, which will be used to name the trampoline binary
+    let target_triplet = env::var("TARGET").expect("TARGET env variable should be set by cargo");
+
+    // Build the trampoline binary
+    // we always use --release profile for this
+    Command::new("cargo")
+        .current_dir(&trampoline_crate)
+        .args(&["build", "--release", "--target", target_triplet.as_str()])
+        .status()
+        .expect("Failed to build trampoline crate");
+
+    // Create trampolines directory if it doesn't exist
+    fs::create_dir_all(&trampolines_dir).expect("Failed to create trampolines directory");
+
+    let cargo_target_dir =
+        env::var("CARGO_TARGET_DIR").expect("CARGO_TARGET_DIR should be set by cargo");
+    // Construct the path to the built binary
+    let target_path = PathBuf::from_iter([
+        cargo_target_dir.as_str(),
+        target_triplet.as_str(),
+        "release",
+        PIXI_TRAMPOLINE,
+    ]);
+
+    let built_binary_path = trampoline_crate.join(target_path);
+    let dest_path = trampolines_dir.join(format!("pixi_trampoline-{}", target_triplet));
+
+    // Copy the built binary to the trampolines directory
+    fs::copy(&built_binary_path, &dest_path).expect("Failed to copy second crate binary");
+
+    // Tell cargo to re-run this build script if the trampoline binary code changes
+    println!("cargo:rerun-if-changed=crates/pixi_trampoline/src");
+}