rust/src/config.rs

105 lines
3.8 KiB
Rust

use std::env;
use std::str::FromStr;
fn bool_env_var(key: &str) -> bool {
env::var(key).as_deref() == Ok("1")
}
/// The mode to use for compilation.
#[derive(Copy, Clone, Debug)]
pub enum CodegenMode {
/// AOT compile the crate. This is the default.
Aot,
/// JIT compile and execute the crate.
Jit,
/// JIT compile and execute the crate, but only compile functions the first time they are used.
JitLazy,
}
impl FromStr for CodegenMode {
type Err = String;
fn from_str(s: &str) -> Result<Self, Self::Err> {
match s {
"aot" => Ok(CodegenMode::Aot),
"jit" => Ok(CodegenMode::Jit),
"jit-lazy" => Ok(CodegenMode::JitLazy),
_ => Err(format!("Unknown codegen mode `{}`", s)),
}
}
}
/// Configuration of cg_clif as passed in through `-Cllvm-args` and various env vars.
#[derive(Clone, Debug)]
pub struct BackendConfig {
/// Should the crate be AOT compiled or JIT executed.
///
/// Defaults to AOT compilation. Can be set using `-Cllvm-args=mode=...`.
pub codegen_mode: CodegenMode,
/// When JIT mode is enable pass these arguments to the program.
///
/// Defaults to the value of `CG_CLIF_JIT_ARGS`.
pub jit_args: Vec<String>,
/// Enable the Cranelift ir verifier for all compilation passes. If not set it will only run
/// once before passing the clif ir to Cranelift for compilation.
///
/// Defaults to true when the `CG_CLIF_ENABLE_VERIFIER` env var is set to 1 or when cg_clif is
/// compiled with debug assertions enabled or false otherwise. Can be set using
/// `-Cllvm-args=enable_verifier=...`.
pub enable_verifier: bool,
/// Don't cache object files in the incremental cache. Useful during development of cg_clif
/// to make it possible to use incremental mode for all analyses performed by rustc without
/// caching object files when their content should have been changed by a change to cg_clif.
///
/// Defaults to true when the `CG_CLIF_DISABLE_INCR_CACHE` env var is set to 1 or false
/// otherwise. Can be set using `-Cllvm-args=disable_incr_cache=...`.
pub disable_incr_cache: bool,
}
impl Default for BackendConfig {
fn default() -> Self {
BackendConfig {
codegen_mode: CodegenMode::Aot,
jit_args: {
let args = std::env::var("CG_CLIF_JIT_ARGS").unwrap_or_else(|_| String::new());
args.split(' ').map(|arg| arg.to_string()).collect()
},
enable_verifier: cfg!(debug_assertions) || bool_env_var("CG_CLIF_ENABLE_VERIFIER"),
disable_incr_cache: bool_env_var("CG_CLIF_DISABLE_INCR_CACHE"),
}
}
}
impl BackendConfig {
/// Parse the configuration passed in using `-Cllvm-args`.
pub fn from_opts(opts: &[String]) -> Result<Self, String> {
fn parse_bool(name: &str, value: &str) -> Result<bool, String> {
value.parse().map_err(|_| format!("failed to parse value `{}` for {}", value, name))
}
let mut config = BackendConfig::default();
for opt in opts {
if opt.starts_with("-import-instr-limit") {
// Silently ignore -import-instr-limit. It is set by rust's build system even when
// testing cg_clif.
continue;
}
if let Some((name, value)) = opt.split_once('=') {
match name {
"mode" => config.codegen_mode = value.parse()?,
"enable_verifier" => config.enable_verifier = parse_bool(name, value)?,
"disable_incr_cache" => config.disable_incr_cache = parse_bool(name, value)?,
_ => return Err(format!("Unknown option `{}`", name)),
}
} else {
return Err(format!("Invalid option `{}`", opt));
}
}
Ok(config)
}
}