4 fn bool_env_var(key: &str) -> bool {
5 env::var(key).as_deref() == Ok("1")
8 /// The mode to use for compilation.
9 #[derive(Copy, Clone, Debug)]
10 pub enum CodegenMode {
11 /// AOT compile the crate. This is the default.
13 /// JIT compile and execute the crate.
15 /// JIT compile and execute the crate, but only compile functions the first time they are used.
19 impl FromStr for CodegenMode {
22 fn from_str(s: &str) -> Result<Self, Self::Err> {
24 "aot" => Ok(CodegenMode::Aot),
25 "jit" => Ok(CodegenMode::Jit),
26 "jit-lazy" => Ok(CodegenMode::JitLazy),
27 _ => Err(format!("Unknown codegen mode `{}`", s)),
32 /// Configuration of cg_clif as passed in through `-Cllvm-args` and various env vars.
33 #[derive(Clone, Debug)]
34 pub struct BackendConfig {
35 /// Should the crate be AOT compiled or JIT executed.
37 /// Defaults to AOT compilation. Can be set using `-Cllvm-args=mode=...`.
38 pub codegen_mode: CodegenMode,
40 /// When JIT mode is enable pass these arguments to the program.
42 /// Defaults to the value of `CG_CLIF_JIT_ARGS`.
43 pub jit_args: Vec<String>,
45 /// Enable the Cranelift ir verifier for all compilation passes. If not set it will only run
46 /// once before passing the clif ir to Cranelift for compilation.
48 /// Defaults to true when the `CG_CLIF_ENABLE_VERIFIER` env var is set to 1 or when cg_clif is
49 /// compiled with debug assertions enabled or false otherwise. Can be set using
50 /// `-Cllvm-args=enable_verifier=...`.
51 pub enable_verifier: bool,
53 /// Don't cache object files in the incremental cache. Useful during development of cg_clif
54 /// to make it possible to use incremental mode for all analyses performed by rustc without
55 /// caching object files when their content should have been changed by a change to cg_clif.
57 /// Defaults to true when the `CG_CLIF_DISABLE_INCR_CACHE` env var is set to 1 or false
58 /// otherwise. Can be set using `-Cllvm-args=disable_incr_cache=...`.
59 pub disable_incr_cache: bool,
62 impl Default for BackendConfig {
63 fn default() -> Self {
65 codegen_mode: CodegenMode::Aot,
67 let args = std::env::var("CG_CLIF_JIT_ARGS").unwrap_or_else(|_| String::new());
68 args.split(' ').map(|arg| arg.to_string()).collect()
70 enable_verifier: cfg!(debug_assertions) || bool_env_var("CG_CLIF_ENABLE_VERIFIER"),
71 disable_incr_cache: bool_env_var("CG_CLIF_DISABLE_INCR_CACHE"),
77 /// Parse the configuration passed in using `-Cllvm-args`.
78 pub fn from_opts(opts: &[String]) -> Result<Self, String> {
79 fn parse_bool(name: &str, value: &str) -> Result<bool, String> {
80 value.parse().map_err(|_| format!("failed to parse value `{}` for {}", value, name))
83 let mut config = BackendConfig::default();
85 if let Some((name, value)) = opt.split_once('=') {
87 "mode" => config.codegen_mode = value.parse()?,
88 "enable_verifier" => config.enable_verifier = parse_bool(name, value)?,
89 "disable_incr_cache" => config.disable_incr_cache = parse_bool(name, value)?,
90 _ => return Err(format!("Unknown option `{}`", name)),
93 return Err(format!("Invalid option `{}`", opt));