use crate::errors;
use info;
use libloading::Library;
use rustc_ast as ast;
use rustc_codegen_ssa::traits::CodegenBackend;
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
#[cfg(parallel_compiler)]
use rustc_data_structures::sync;
use rustc_errors::registry::Registry;
use rustc_parse::validate_attr;
use rustc_session as session;
use rustc_session::config::CheckCfg;
use rustc_session::config::{self, CrateType};
use rustc_session::config::{OutFileName, OutputFilenames, OutputTypes};
use rustc_session::filesearch::sysroot_candidates;
use rustc_session::lint::{self, BuiltinLintDiagnostics, LintBuffer};
use rustc_session::parse::CrateConfig;
use rustc_session::{filesearch, output, Session};
use rustc_span::edit_distance::find_best_match_for_name;
use rustc_span::edition::Edition;
use rustc_span::source_map::FileLoader;
use rustc_span::symbol::{sym, Symbol};
use session::{CompilerIO, EarlyErrorHandler};
use std::env;
use std::env::consts::{DLL_PREFIX, DLL_SUFFIX};
use std::mem;
use std::path::{Path, PathBuf};
use std::sync::atomic::{AtomicBool, Ordering};
use std::sync::OnceLock;
use std::thread;
pub type MakeBackendFn = fn() -> Box<dyn CodegenBackend>;
pub fn add_configuration(
cfg: &mut CrateConfig,
sess: &mut Session,
codegen_backend: &dyn CodegenBackend,
) {
let tf = sym::target_feature;
let unstable_target_features = codegen_backend.target_features(sess, true);
sess.unstable_target_features.extend(unstable_target_features.iter().cloned());
let target_features = codegen_backend.target_features(sess, false);
sess.target_features.extend(target_features.iter().cloned());
cfg.extend(target_features.into_iter().map(|feat| (tf, Some(feat))));
if sess.crt_static(None) {
cfg.insert((tf, Some(sym::crt_dash_static)));
}
}
pub fn create_session(
handler: &EarlyErrorHandler,
sopts: config::Options,
cfg: FxHashSet<(String, Option<String>)>,
check_cfg: CheckCfg,
locale_resources: &'static [&'static str],
file_loader: Option<Box<dyn FileLoader + Send + Sync + 'static>>,
io: CompilerIO,
lint_caps: FxHashMap<lint::LintId, lint::Level>,
make_codegen_backend: Option<
Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>,
>,
descriptions: Registry,
ice_file: Option<PathBuf>,
expanded_args: Vec<String>,
) -> (Session, Box<dyn CodegenBackend>) {
let codegen_backend = if let Some(make_codegen_backend) = make_codegen_backend {
make_codegen_backend(&sopts)
} else {
get_codegen_backend(
handler,
&sopts.maybe_sysroot,
sopts.unstable_opts.codegen_backend.as_deref(),
)
};
let target_override = codegen_backend.target_override(&sopts);
let bundle = match rustc_errors::fluent_bundle(
sopts.maybe_sysroot.clone(),
sysroot_candidates().to_vec(),
sopts.unstable_opts.translate_lang.clone(),
sopts.unstable_opts.translate_additional_ftl.as_deref(),
sopts.unstable_opts.translate_directionality_markers,
) {
Ok(bundle) => bundle,
Err(e) => {
handler.early_error(format!("failed to load fluent bundle: {e}"));
}
};
let mut locale_resources = Vec::from(locale_resources);
locale_resources.push(codegen_backend.locale_resource());
let mut sess = session::build_session(
handler,
sopts,
io,
bundle,
descriptions,
locale_resources,
lint_caps,
file_loader,
target_override,
rustc_version_str().unwrap_or("unknown"),
ice_file,
expanded_args,
);
codegen_backend.init(&sess);
let mut cfg = config::build_configuration(&sess, config::to_crate_config(cfg));
add_configuration(&mut cfg, &mut sess, &*codegen_backend);
let mut check_cfg = config::to_crate_check_config(check_cfg);
check_cfg.fill_well_known(&sess.target);
sess.parse_sess.config = cfg;
sess.parse_sess.check_config = check_cfg;
(sess, codegen_backend)
}
const STACK_SIZE: usize = 8 * 1024 * 1024;
fn get_stack_size() -> Option<usize> {
env::var_os("RUST_MIN_STACK").is_none().then_some(STACK_SIZE)
}
pub(crate) fn run_in_thread_with_globals<F: FnOnce() -> R + Send, R: Send>(
edition: Edition,
f: F,
) -> R {
let mut builder = thread::Builder::new().name("rustc".to_string());
if let Some(size) = get_stack_size() {
builder = builder.stack_size(size);
}
thread::scope(|s| {
let r = builder
.spawn_scoped(s, move || rustc_span::create_session_globals_then(edition, f))
.unwrap()
.join();
match r {
Ok(v) => v,
Err(e) => std::panic::resume_unwind(e),
}
})
}
#[cfg(not(parallel_compiler))]
pub(crate) fn run_in_thread_pool_with_globals<F: FnOnce() -> R + Send, R: Send>(
edition: Edition,
_threads: usize,
f: F,
) -> R {
run_in_thread_with_globals(edition, f)
}
#[cfg(parallel_compiler)]
pub(crate) fn run_in_thread_pool_with_globals<F: FnOnce() -> R + Send, R: Send>(
edition: Edition,
threads: usize,
f: F,
) -> R {
use rustc_data_structures::{jobserver, sync::FromDyn};
use rustc_middle::ty::tls;
use rustc_query_impl::QueryCtxt;
use rustc_query_system::query::{deadlock, QueryContext};
let registry = sync::Registry::new(threads);
if !sync::is_dyn_thread_safe() {
return run_in_thread_with_globals(edition, || {
registry.register();
f()
});
}
let mut builder = rayon::ThreadPoolBuilder::new()
.thread_name(|_| "rustc".to_string())
.acquire_thread_handler(jobserver::acquire_thread)
.release_thread_handler(jobserver::release_thread)
.num_threads(threads)
.deadlock_handler(|| {
let query_map = FromDyn::from(tls::with(|tcx| {
QueryCtxt::new(tcx)
.try_collect_active_jobs()
.expect("active jobs shouldn't be locked in deadlock handler")
}));
let registry = rayon_core::Registry::current();
thread::spawn(move || deadlock(query_map.into_inner(), ®istry));
});
if let Some(size) = get_stack_size() {
builder = builder.stack_size(size);
}
rustc_span::create_session_globals_then(edition, || {
rustc_span::with_session_globals(|session_globals| {
let session_globals = FromDyn::from(session_globals);
builder
.build_scoped(
move |thread: rayon::ThreadBuilder| {
registry.register();
rustc_span::set_session_globals_then(session_globals.into_inner(), || {
thread.run()
})
},
move |pool: &rayon::ThreadPool| pool.install(f),
)
.unwrap()
})
})
}
fn load_backend_from_dylib(handler: &EarlyErrorHandler, path: &Path) -> MakeBackendFn {
let lib = unsafe { Library::new(path) }.unwrap_or_else(|err| {
let err = format!("couldn't load codegen backend {path:?}: {err}");
handler.early_error(err);
});
let backend_sym = unsafe { lib.get::<MakeBackendFn>(b"__rustc_codegen_backend") }
.unwrap_or_else(|e| {
let err = format!("couldn't load codegen backend: {e}");
handler.early_error(err);
});
let backend_sym = unsafe { backend_sym.into_raw() };
mem::forget(lib);
*backend_sym
}
pub fn get_codegen_backend(
handler: &EarlyErrorHandler,
maybe_sysroot: &Option<PathBuf>,
backend_name: Option<&str>,
) -> Box<dyn CodegenBackend> {
static LOAD: OnceLock<unsafe fn() -> Box<dyn CodegenBackend>> = OnceLock::new();
let load = LOAD.get_or_init(|| {
let default_codegen_backend = option_env!("CFG_DEFAULT_CODEGEN_BACKEND").unwrap_or("llvm");
match backend_name.unwrap_or(default_codegen_backend) {
filename if filename.contains('.') => {
load_backend_from_dylib(handler, filename.as_ref())
}
#[cfg(feature = "llvm")]
"llvm" => rustc_codegen_llvm::LlvmCodegenBackend::new,
backend_name => get_codegen_sysroot(handler, maybe_sysroot, backend_name),
}
});
unsafe { load() }
}
pub fn rustc_path<'a>() -> Option<&'a Path> {
static RUSTC_PATH: OnceLock<Option<PathBuf>> = OnceLock::new();
const BIN_PATH: &str = env!("RUSTC_INSTALL_BINDIR");
RUSTC_PATH.get_or_init(|| get_rustc_path_inner(BIN_PATH)).as_deref()
}
fn get_rustc_path_inner(bin_path: &str) -> Option<PathBuf> {
sysroot_candidates().iter().find_map(|sysroot| {
let candidate = sysroot.join(bin_path).join(if cfg!(target_os = "windows") {
"rustc.exe"
} else {
"rustc"
});
candidate.exists().then_some(candidate)
})
}
fn get_codegen_sysroot(
handler: &EarlyErrorHandler,
maybe_sysroot: &Option<PathBuf>,
backend_name: &str,
) -> MakeBackendFn {
static LOADED: AtomicBool = AtomicBool::new(false);
assert!(
!LOADED.fetch_or(true, Ordering::SeqCst),
"cannot load the default codegen backend twice"
);
let target = session::config::host_triple();
let sysroot_candidates = sysroot_candidates();
let sysroot = maybe_sysroot
.iter()
.chain(sysroot_candidates.iter())
.map(|sysroot| {
filesearch::make_target_lib_path(sysroot, target).with_file_name("codegen-backends")
})
.find(|f| {
info!("codegen backend candidate: {}", f.display());
f.exists()
});
let sysroot = sysroot.unwrap_or_else(|| {
let candidates = sysroot_candidates
.iter()
.map(|p| p.display().to_string())
.collect::<Vec<_>>()
.join("\n* ");
let err = format!(
"failed to find a `codegen-backends` folder \
in the sysroot candidates:\n* {candidates}"
);
handler.early_error(err);
});
info!("probing {} for a codegen backend", sysroot.display());
let d = sysroot.read_dir().unwrap_or_else(|e| {
let err = format!(
"failed to load default codegen backend, couldn't \
read `{}`: {}",
sysroot.display(),
e
);
handler.early_error(err);
});
let mut file: Option<PathBuf> = None;
let expected_names = &[
format!("rustc_codegen_{}-{}", backend_name, env!("CFG_RELEASE")),
format!("rustc_codegen_{backend_name}"),
];
for entry in d.filter_map(|e| e.ok()) {
let path = entry.path();
let Some(filename) = path.file_name().and_then(|s| s.to_str()) else { continue };
if !(filename.starts_with(DLL_PREFIX) && filename.ends_with(DLL_SUFFIX)) {
continue;
}
let name = &filename[DLL_PREFIX.len()..filename.len() - DLL_SUFFIX.len()];
if !expected_names.iter().any(|expected| expected == name) {
continue;
}
if let Some(ref prev) = file {
let err = format!(
"duplicate codegen backends found\n\
first: {}\n\
second: {}\n\
",
prev.display(),
path.display()
);
handler.early_error(err);
}
file = Some(path.clone());
}
match file {
Some(ref s) => load_backend_from_dylib(handler, s),
None => {
let err = format!("unsupported builtin codegen backend `{backend_name}`");
handler.early_error(err);
}
}
}
pub(crate) fn check_attr_crate_type(
sess: &Session,
attrs: &[ast::Attribute],
lint_buffer: &mut LintBuffer,
) {
for a in attrs.iter() {
if a.has_name(sym::crate_type) {
if let Some(n) = a.value_str() {
if categorize_crate_type(n).is_some() {
return;
}
if let ast::MetaItemKind::NameValue(spanned) = a.meta_kind().unwrap() {
let span = spanned.span;
let lev_candidate = find_best_match_for_name(
&CRATE_TYPES.iter().map(|(k, _)| *k).collect::<Vec<_>>(),
n,
None,
);
if let Some(candidate) = lev_candidate {
lint_buffer.buffer_lint_with_diagnostic(
lint::builtin::UNKNOWN_CRATE_TYPES,
ast::CRATE_NODE_ID,
span,
"invalid `crate_type` value",
BuiltinLintDiagnostics::UnknownCrateTypes(
span,
"did you mean".to_string(),
format!("\"{candidate}\""),
),
);
} else {
lint_buffer.buffer_lint(
lint::builtin::UNKNOWN_CRATE_TYPES,
ast::CRATE_NODE_ID,
span,
"invalid `crate_type` value",
);
}
}
} else {
validate_attr::emit_fatal_malformed_builtin_attribute(
&sess.parse_sess,
a,
sym::crate_type,
);
}
}
}
}
const CRATE_TYPES: &[(Symbol, CrateType)] = &[
(sym::rlib, CrateType::Rlib),
(sym::dylib, CrateType::Dylib),
(sym::cdylib, CrateType::Cdylib),
(sym::lib, config::default_lib_output()),
(sym::staticlib, CrateType::Staticlib),
(sym::proc_dash_macro, CrateType::ProcMacro),
(sym::bin, CrateType::Executable),
];
fn categorize_crate_type(s: Symbol) -> Option<CrateType> {
Some(CRATE_TYPES.iter().find(|(key, _)| *key == s)?.1)
}
pub fn collect_crate_types(session: &Session, attrs: &[ast::Attribute]) -> Vec<CrateType> {
let attr_types: Vec<CrateType> = attrs
.iter()
.filter_map(|a| {
if a.has_name(sym::crate_type) {
match a.value_str() {
Some(s) => categorize_crate_type(s),
_ => None,
}
} else {
None
}
})
.collect();
if session.opts.test {
return vec![CrateType::Executable];
}
#[allow(rustc::bad_opt_access)]
let mut base = session.opts.crate_types.clone();
if base.is_empty() {
base.extend(attr_types);
if base.is_empty() {
base.push(output::default_output_for_target(session));
} else {
base.sort();
base.dedup();
}
}
base.retain(|crate_type| {
if output::invalid_output_for_target(session, *crate_type) {
session.emit_warning(errors::UnsupportedCrateTypeForTarget {
crate_type: *crate_type,
target_triple: &session.opts.target_triple,
});
false
} else {
true
}
});
base
}
fn multiple_output_types_to_stdout(
output_types: &OutputTypes,
single_output_file_is_stdout: bool,
) -> bool {
use std::io::IsTerminal;
if std::io::stdout().is_terminal() {
let named_text_types = output_types
.iter()
.filter(|(f, o)| f.is_text_output() && *o == &Some(OutFileName::Stdout))
.count();
let unnamed_text_types =
output_types.iter().filter(|(f, o)| f.is_text_output() && o.is_none()).count();
named_text_types > 1 || unnamed_text_types > 1 && single_output_file_is_stdout
} else {
let named_types =
output_types.values().filter(|o| *o == &Some(OutFileName::Stdout)).count();
let unnamed_types = output_types.values().filter(|o| o.is_none()).count();
named_types > 1 || unnamed_types > 1 && single_output_file_is_stdout
}
}
pub fn build_output_filenames(attrs: &[ast::Attribute], sess: &Session) -> OutputFilenames {
if multiple_output_types_to_stdout(
&sess.opts.output_types,
sess.io.output_file == Some(OutFileName::Stdout),
) {
sess.emit_fatal(errors::MultipleOutputTypesToStdout);
}
let crate_name = sess
.opts
.crate_name
.clone()
.or_else(|| rustc_attr::find_crate_name(attrs).map(|n| n.to_string()));
match sess.io.output_file {
None => {
let dirpath = sess.io.output_dir.clone().unwrap_or_default();
let stem = crate_name.clone().unwrap_or_else(|| sess.io.input.filestem().to_owned());
OutputFilenames::new(
dirpath,
crate_name.unwrap_or_else(|| stem.replace('-', "_")),
stem,
None,
sess.io.temps_dir.clone(),
sess.opts.cg.extra_filename.clone(),
sess.opts.output_types.clone(),
)
}
Some(ref out_file) => {
let unnamed_output_types =
sess.opts.output_types.values().filter(|a| a.is_none()).count();
let ofile = if unnamed_output_types > 1 {
sess.emit_warning(errors::MultipleOutputTypesAdaption);
None
} else {
if !sess.opts.cg.extra_filename.is_empty() {
sess.emit_warning(errors::IgnoringExtraFilename);
}
Some(out_file.clone())
};
if sess.io.output_dir != None {
sess.emit_warning(errors::IgnoringOutDir);
}
let out_filestem =
out_file.filestem().unwrap_or_default().to_str().unwrap().to_string();
OutputFilenames::new(
out_file.parent().unwrap_or_else(|| Path::new("")).to_path_buf(),
crate_name.unwrap_or_else(|| out_filestem.replace('-', "_")),
out_filestem,
ofile,
sess.io.temps_dir.clone(),
sess.opts.cg.extra_filename.clone(),
sess.opts.output_types.clone(),
)
}
}
}
pub macro version_str() {
option_env!("CFG_VERSION")
}
pub fn rustc_version_str() -> Option<&'static str> {
version_str!()
}