feat: use the build script to download the cairo crate (#597)

crates/starknet_sierra_compile/build.rs

@@ -0,0 +1,90 @@
+use std::path::Path;
+use std::process::Command;
+
+fn main() {
+    println!("cargo:rerun-if-changed=../../Cargo.lock");
+    println!("cargo:rerun-if-changed=build.rs");
+
+    install_starknet_sierra_compile();
+}
+
+const BINARY_NAME: &str = "starknet-sierra-compile";
+const REQUIRED_VERSION: &str = "2.7.1";
+
+/// Downloads the Cairo crate from StarkWare's release page and extracts its contents into the
+/// `target` directory. This crate includes the `starknet-sierra-compile` binary, which is used to
+/// compile Sierra to Casm. The binary is executed as a subprocess whenever Sierra compilation is
+/// required.
+fn install_starknet_sierra_compile() {
+    let out_dir = Path::new(
+        &std::env::var("OUT_DIR").expect("Failed to get the OUT_DIR environment variable"),
+    )
+    .to_path_buf();
+    // Get the crate's `OUT_DIR` and navigate up to reach the `target/BUILD_FLAVOR` directory.
+    // This directory is shared accross all crates in this project.
+    let shared_folder_dir = out_dir
+        .ancestors()
+        .nth(3)
+        .expect("Failed to navigate up three levels from OUT_DIR")
+        .join("shared_executables");
+    let binary_path = shared_folder_dir.join(BINARY_NAME);
+
+    match Command::new(&binary_path).args(["--version"]).output() {
+        Ok(binary_version) => {
+            let binary_version = String::from_utf8(binary_version.stdout)
+                .expect("Failed to convert the binary version to a string.");
+            if binary_version.contains(REQUIRED_VERSION) {
+                println!("The starknet-sierra-compile binary is up to date.");
+                return;
+            } else {
+                println!(
+                    "The starknet-sierra-compile binary is not up to date. Installing the \
+                     required version."
+                );
+                std::fs::remove_file(&binary_path).expect("Failed to remove the old binary.");
+            }
+        }
+        Err(_) => {
+            println!(
+                "The starknet-sierra-compile binary is not installed. Installing the required \
+                 version."
+            );
+        }
+    }
+
+    let temp_cargo_path = out_dir.join("cargo");
+    let post_install_file_path = temp_cargo_path.join("bin").join(BINARY_NAME);
+
+    // Create the temporary cargo directory if it doesn't exist
+    std::fs::create_dir_all(&temp_cargo_path).expect("Failed to create cargo directory");
+    let install_command_status = Command::new("cargo")
+        .args([
+            "install",
+            BINARY_NAME,
+            "--root",
+            temp_cargo_path.to_str().expect("Failed to convert cargo_path to str"),
+            "--version",
+            REQUIRED_VERSION,
+        ])
+        .status()
+        .expect("Failed to install starknet-sierra-compile");
+
+    if !install_command_status.success() {
+        panic!("Failed to install starknet-sierra-compile");
+    }
+
+    // Move the 'starknet-sierra-compile' executable to a shared location
+    std::fs::create_dir_all(shared_folder_dir).expect("Failed to create shared executables folder");
+    let move_command_status = Command::new("mv")
+        .args([post_install_file_path.as_os_str(), binary_path.as_os_str()])
+        .status()
+        .expect("Failed to perform mv command.");
+
+    if !move_command_status.success() {
+        panic!("Failed to move the starknet-sierra-compile binary to the shared folder.");
+    }
+
+    std::fs::remove_dir_all(temp_cargo_path).expect("Failed to remove the cargo directory.");
+
+    println!("Successfully set executable file: {:?}", binary_path.display());
+}