jam_pvm_builder/

lib.rs

//! Builder logic for creating PVM code blobs for execution on the JAM PVM instances (service code
//! and authorizer code).

#![allow(clippy::unwrap_used)]

// If you update this, you should also update the toolchain installed by .github/workflows/rust.yml
const TOOLCHAIN: &str = "nightly-2024-11-01";

use jam_program_blob::{ConventionalMetadata, CrateInfo, ProgramBlob};
use scale::Encode;
use std::{
	fmt::Display,
	fs,
	path::{Path, PathBuf},
	process::Command,
	sync::OnceLock,
};

pub enum BlobType {
	Service,
	Authorizer,
	CoreVm,
}
impl Display for BlobType {
	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
		match self {
			Self::Service => write!(f, "Service"),
			Self::Authorizer => write!(f, "Authorizer"),
			Self::CoreVm => write!(f, "CoreVm"),
		}
	}
}

impl BlobType {
	pub fn dispatch_table(&self) -> Vec<Vec<u8>> {
		match self {
			Self::Service =>
				vec![b"refine_ext".into(), b"accumulate_ext".into(), b"on_transfer_ext".into()],
			Self::Authorizer => vec![b"is_authorized_ext".into()],
			Self::CoreVm => vec![b"main".into()],
		}
	}
}

pub enum ProfileType {
	Debug,
	Release,
	Other(&'static str),
}
impl ProfileType {
	fn as_str(&self) -> &'static str {
		match self {
			ProfileType::Debug => "debug",
			ProfileType::Release => "release",
			ProfileType::Other(s) => s,
		}
	}
	fn to_arg(&self) -> String {
		match self {
			ProfileType::Debug => "--debug".into(),
			ProfileType::Release => "--release".into(),
			ProfileType::Other(s) => format!("--profile={s}"),
		}
	}
}

fn build_pvm_blob_in_build_script(crate_dir: &Path, blob_type: BlobType) {
	let out_dir: PathBuf = std::env::var("OUT_DIR").expect("No OUT_DIR").into();
	println!("cargo:rerun-if-env-changed=SKIP_PVM_BUILDS");
	if std::env::var_os("SKIP_PVM_BUILDS").is_some() {
		let output_file = out_dir.join(format!("{}.jam", &get_crate_info(crate_dir).name));
		fs::write(&output_file, []).expect("error creating dummy .jam blob");
	} else {
		println!("cargo:rerun-if-changed={}", crate_dir.to_str().unwrap());
		build_pvm_blob(crate_dir, blob_type, &out_dir, false, ProfileType::Release);
	}
}

/// Build the service crate in `crate_dir` for the RISCV target, convert to PVM code and finish
/// by creating a `<crate_name>.pvm` blob file.
///
/// This is intended to be called from a crate's `build.rs`. The generated blob may be included in
/// the crate by using the `pvm_binary` macro.
pub fn build_service(crate_dir: &Path) {
	build_pvm_blob_in_build_script(crate_dir, BlobType::Service);
}

/// Build the authorizer crate in `crate_dir` for the RISCV target, convert to PVM code and finish
/// by creating a `<crate_name>.pvm` blob file.
///
/// This is intended to be called from a crate's `build.rs`. The generated blob may be included in
/// the crate by using the `pvm_binary` macro.
pub fn build_authorizer(crate_dir: &Path) {
	build_pvm_blob_in_build_script(crate_dir, BlobType::Authorizer);
}

/// Build the CoreVM guest program crate in `crate_dir` for the RISCV target, convert to PVM code
/// and finish by creating a `<crate_name>.pvm` blob file.
///
/// If used in `build.rs`, then this may be included in the relevant crate by using the `pvm_binary`
/// macro.
pub fn build_core_vm(crate_dir: &Path) {
	build_pvm_blob_in_build_script(crate_dir, BlobType::CoreVm);
}

fn get_crate_info(crate_dir: &Path) -> CrateInfo {
	let manifest = Command::new("cargo")
		.current_dir(crate_dir)
		.arg("read-manifest")
		.output()
		.unwrap()
		.stdout;
	let man = serde_json::from_slice::<serde_json::Value>(&manifest).unwrap();
	let name = man.get("name").unwrap().as_str().unwrap().to_string();
	let version = man.get("version").unwrap().as_str().unwrap().to_string();
	let license = man.get("license").unwrap().as_str().unwrap().to_string();
	let authors = man
		.get("authors")
		.unwrap()
		.as_array()
		.unwrap()
		.iter()
		.map(|x| x.as_str().unwrap().to_owned())
		.collect::<Vec<String>>();
	CrateInfo { name, version, license, authors }
}

/// Build the PVM crate in `crate_dir` called `crate_name` for the RISCV target, convert to PVM
/// code and finish by creating a `.pvm` blob file of path `output_file`. `out_dir` is used to store
/// any intermediate build files.
pub fn build_pvm_blob(
	crate_dir: &Path,
	blob_type: BlobType,
	out_dir: &Path,
	install_rustc: bool,
	profile: ProfileType,
) -> (String, PathBuf) {
	let (target_name, target_json_path) =
		("riscv64emac-unknown-none-polkavm", polkavm_linker::target_json_64_path().unwrap());

	println!("🪤 PVM module type: {}", blob_type);
	println!("🎯 Target name: {}", target_name);

	let rustup_installed = if Command::new("rustup").output().is_ok() {
		let output = Command::new("rustup")
			.args(["component", "list", "--toolchain", TOOLCHAIN, "--installed"])
			.output()
			.unwrap_or_else(|_| {
				panic!(
				"Failed to execute `rustup component list --toolchain {TOOLCHAIN} --installed`.\n\
		Please install `rustup` to continue.",
			)
			});

		if !output.status.success() ||
			!output.stdout.split(|x| *x == b'\n').any(|x| x[..] == b"rust-src"[..])
		{
			if install_rustc {
				println!("Installing rustc dependencies...");
				let mut child = Command::new("rustup")
					.args(["toolchain", "install", TOOLCHAIN, "-c", "rust-src"])
					.stdout(std::process::Stdio::inherit())
					.stderr(std::process::Stdio::inherit())
					.spawn()
					.unwrap_or_else(|_| {
						panic!(
						"Failed to execute `rustup toolchain install {TOOLCHAIN} -c rust-src`.\n\
				Please install `rustup` to continue."
					)
					});
				if !child.wait().expect("Failed to execute rustup process").success() {
					panic!("Failed to install `rust-src` component of {TOOLCHAIN}.");
				}
			} else {
				panic!("`rust-src` component of {TOOLCHAIN} is required to build the PVM binary.",);
			}
		}

		true
	} else {
		println!("ℹ️ `rustup` not installed, here be dragons. Continuing build process...");

		false
	};

	let info = get_crate_info(crate_dir);
	println!("📦 Crate name: {}", info.name);
	println!("🏷️ Build profile: {}", profile.as_str());

	let mut child = Command::new("cargo");

	child
		.current_dir(crate_dir)
		.env_clear()
		.env("PATH", std::env::var("PATH").unwrap())
		.env("RUSTFLAGS", "-C panic=abort")
		.env("CARGO_TARGET_DIR", out_dir)
		// Support building on stable. (required for `-Zbuild-std`)
		.env("RUSTC_BOOTSTRAP", "1");

	if rustup_installed {
		child.arg(format!("+{TOOLCHAIN}"));
	}

	child
		.args(["build", "-Z", "build-std=core,alloc"])
		.arg(profile.to_arg())
		.arg("--target")
		.arg(target_json_path)
		.arg("--features")
		.arg(if cfg!(feature = "tiny") { "tiny" } else { "" });

	// Use job server to not oversubscribe CPU cores when compiling multiple PVM binaries in
	// parallel.
	if let Some(client) = get_job_server_client() {
		client.configure(&mut child);
	}

	let mut child = child.spawn().expect("Failed to execute cargo process");
	let status = child.wait().expect("Failed to execute cargo process");

	if !status.success() {
		eprintln!("Failed to build RISC-V ELF due to cargo execution error");
		std::process::exit(1);
	}

	// Post processing
	println!("Converting RISC-V ELF to PVM blob...");
	let mut config = polkavm_linker::Config::default();
	config.set_strip(true);
	config.set_dispatch_table(blob_type.dispatch_table());
	let input_path = &out_dir.join(target_name).join(profile.as_str()).join(&info.name);
	let orig =
		fs::read(input_path).unwrap_or_else(|e| panic!("Failed to read {:?} :{:?}", input_path, e));
	let linked = polkavm_linker::program_from_elf(config, orig.as_ref())
		.expect("Failed to link polkavm program:");

	// Write out a full `.polkavm` blob for debugging/inspection.
	let output_path_polkavm = &out_dir.join(format!("{}.polkavm", &info.name));
	fs::write(output_path_polkavm, &linked).expect("Error writing resulting binary");

	let parts = polkavm_linker::ProgramParts::from_bytes(linked.into())
		.expect("failed to deserialize linked PolkaVM program");

	let rw_data_padding = parts.rw_data_size as usize - parts.rw_data.len();
	let rw_data_padding_pages = rw_data_padding / 4096;

	let mut ro_data = parts.ro_data.to_vec();
	let mut rw_data = parts.rw_data.to_vec();

	ro_data.resize(parts.ro_data_size as usize, 0);
	rw_data.resize(ro_data.len() + parts.rw_data_size as usize - rw_data_padding_pages * 4096, 0);

	let name = info.name.clone();

	let rw_data_padding_pages: u16 =
		rw_data_padding_pages.try_into().expect("the RW data section is too big");
	let blob_jam = ProgramBlob {
		metadata: ConventionalMetadata::Info(info).encode().into(),
		ro_data: ro_data.into(),
		rw_data: (&parts.rw_data[..]).into(),
		code_blob: (&parts.code_and_jump_table[..]).into(),
		rw_data_padding_pages,
		stack_size: parts.stack_size,
	};

	let output_file = out_dir.join(format!("{}.jam", &name));
	fs::write(&output_file, blob_jam.to_vec().expect("error serializing the .jam blob"))
		.expect("error writing the .jam blob");

	(name, output_file)
}

fn get_job_server_client() -> Option<&'static jobserver::Client> {
	static CLIENT: OnceLock<Option<jobserver::Client>> = OnceLock::new();
	CLIENT.get_or_init(|| unsafe { jobserver::Client::from_env() }).as_ref()
}

#[macro_export]
macro_rules! pvm_binary {
	($name:literal) => {
		include_bytes!(concat!(env!("OUT_DIR"), "/", $name, ".jam"))
	};
}