use std::env::consts::{DLL_PREFIX, DLL_SUFFIX};
use std::path::{Path, PathBuf};
use std::sync::atomic::{AtomicBool, Ordering};
use std::sync::OnceLock;
use std::{env, iter, thread};
use rustc_ast as ast;
use rustc_codegen_ssa::traits::CodegenBackend;
#[cfg(parallel_compiler)]
use rustc_data_structures::sync;
use rustc_metadata::{load_symbol_from_dylib, DylibError};
use rustc_middle::ty::CurrentGcx;
use rustc_parse::validate_attr;
use rustc_session::config::{host_triple, Cfg, OutFileName, OutputFilenames, OutputTypes};
use rustc_session::filesearch::sysroot_candidates;
use rustc_session::lint::{self, BuiltinLintDiag, LintBuffer};
use rustc_session::output::{categorize_crate_type, CRATE_TYPES};
use rustc_session::{filesearch, EarlyDiagCtxt, Session};
use rustc_span::edit_distance::find_best_match_for_name;
use rustc_span::edition::Edition;
use rustc_span::source_map::SourceMapInputs;
use rustc_span::symbol::sym;
use rustc_target::spec::Target;
use tracing::info;
use crate::errors;
pub type MakeBackendFn = fn() -> Box<dyn CodegenBackend>;
pub fn add_configuration(cfg: &mut Cfg, 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 static STACK_SIZE: OnceLock<usize> = OnceLock::new();
pub const DEFAULT_STACK_SIZE: usize = 8 * 1024 * 1024;
fn init_stack_size(early_dcx: &EarlyDiagCtxt) -> usize {
*STACK_SIZE.get_or_init(|| {
env::var_os("RUST_MIN_STACK")
.as_ref()
.map(|os_str| os_str.to_string_lossy())
.filter(|s| !s.trim().is_empty())
.map(|s| {
let s = s.trim();
#[allow(rustc::untranslatable_diagnostic, rustc::diagnostic_outside_of_impl)]
s.parse::<usize>().unwrap_or_else(|_| {
let mut err = early_dcx.early_struct_fatal(format!(
r#"`RUST_MIN_STACK` should be a number of bytes, but was "{s}""#,
));
err.note("you can also unset `RUST_MIN_STACK` to use the default stack size");
err.emit()
})
})
.unwrap_or(DEFAULT_STACK_SIZE)
})
}
fn run_in_thread_with_globals<F: FnOnce(CurrentGcx) -> R + Send, R: Send>(
thread_stack_size: usize,
edition: Edition,
sm_inputs: SourceMapInputs,
f: F,
) -> R {
let builder = thread::Builder::new().name("rustc".to_string()).stack_size(thread_stack_size);
thread::scope(|s| {
let r = builder
.spawn_scoped(s, move || {
rustc_span::create_session_globals_then(edition, Some(sm_inputs), || {
f(CurrentGcx::new())
})
})
.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(CurrentGcx) -> R + Send, R: Send>(
thread_builder_diag: &EarlyDiagCtxt,
edition: Edition,
_threads: usize,
sm_inputs: SourceMapInputs,
f: F,
) -> R {
let thread_stack_size = init_stack_size(thread_builder_diag);
run_in_thread_with_globals(thread_stack_size, edition, sm_inputs, f)
}
#[cfg(parallel_compiler)]
pub(crate) fn run_in_thread_pool_with_globals<F: FnOnce(CurrentGcx) -> R + Send, R: Send>(
thread_builder_diag: &EarlyDiagCtxt,
edition: Edition,
threads: usize,
sm_inputs: SourceMapInputs,
f: F,
) -> R {
use std::process;
use rustc_data_structures::sync::FromDyn;
use rustc_data_structures::{defer, jobserver};
use rustc_middle::ty::tls;
use rustc_query_impl::QueryCtxt;
use rustc_query_system::query::{break_query_cycles, QueryContext};
let thread_stack_size = init_stack_size(thread_builder_diag);
let registry = sync::Registry::new(std::num::NonZero::new(threads).unwrap());
if !sync::is_dyn_thread_safe() {
return run_in_thread_with_globals(thread_stack_size, edition, sm_inputs, |current_gcx| {
registry.register();
f(current_gcx)
});
}
let current_gcx = FromDyn::from(CurrentGcx::new());
let current_gcx2 = current_gcx.clone();
let 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(move || {
let query_map = current_gcx2.access(|gcx| {
tls::enter_context(&tls::ImplicitCtxt::new(gcx), || {
tls::with(|tcx| QueryCtxt::new(tcx).collect_active_jobs())
})
});
let query_map = FromDyn::from(query_map);
let registry = rayon_core::Registry::current();
thread::Builder::new()
.name("rustc query cycle handler".to_string())
.spawn(move || {
let on_panic = defer(|| {
eprintln!("query cycle handler thread panicked, aborting process");
process::abort();
});
break_query_cycles(query_map.into_inner(), ®istry);
on_panic.disable();
})
.unwrap();
})
.stack_size(thread_stack_size);
rustc_span::create_session_globals_then(edition, Some(sm_inputs), || {
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(current_gcx.into_inner())),
)
.unwrap()
})
})
}
#[allow(rustc::untranslatable_diagnostic)] fn load_backend_from_dylib(early_dcx: &EarlyDiagCtxt, path: &Path) -> MakeBackendFn {
match unsafe { load_symbol_from_dylib::<MakeBackendFn>(path, "__rustc_codegen_backend") } {
Ok(backend_sym) => backend_sym,
Err(DylibError::DlOpen(path, err)) => {
let err = format!("couldn't load codegen backend {path}{err}");
early_dcx.early_fatal(err);
}
Err(DylibError::DlSym(_path, err)) => {
let e = format!(
"`__rustc_codegen_backend` symbol lookup in the codegen backend failed{err}",
);
early_dcx.early_fatal(e);
}
}
}
pub fn get_codegen_backend(
early_dcx: &EarlyDiagCtxt,
sysroot: &Path,
backend_name: Option<&str>,
target: &Target,
) -> Box<dyn CodegenBackend> {
static LOAD: OnceLock<unsafe fn() -> Box<dyn CodegenBackend>> = OnceLock::new();
let load = LOAD.get_or_init(|| {
let backend = backend_name
.or(target.default_codegen_backend.as_deref())
.or(option_env!("CFG_DEFAULT_CODEGEN_BACKEND"))
.unwrap_or("llvm");
match backend {
filename if filename.contains('.') => {
load_backend_from_dylib(early_dcx, filename.as_ref())
}
#[cfg(feature = "llvm")]
"llvm" => rustc_codegen_llvm::LlvmCodegenBackend::new,
backend_name => get_codegen_sysroot(early_dcx, 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)
})
}
#[allow(rustc::untranslatable_diagnostic)] fn get_codegen_sysroot(
early_dcx: &EarlyDiagCtxt,
sysroot: &Path,
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 = host_triple();
let sysroot_candidates = sysroot_candidates();
let sysroot = iter::once(sysroot)
.chain(sysroot_candidates.iter().map(<_>::as_ref))
.map(|sysroot| {
filesearch::make_target_lib_path(sysroot, target).with_file_name("codegen-backends")
})
.find(|f| {
info!("codegen backend candidate: {}", f.display());
f.exists()
})
.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}"
);
early_dcx.early_fatal(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
);
early_dcx.early_fatal(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()
);
early_dcx.early_fatal(err);
}
file = Some(path.clone());
}
match file {
Some(ref s) => load_backend_from_dylib(early_dcx, s),
None => {
let err = format!("unsupported builtin codegen backend `{backend_name}`");
early_dcx.early_fatal(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 candidate = find_best_match_for_name(
&CRATE_TYPES.iter().map(|(k, _)| *k).collect::<Vec<_>>(),
n,
None,
);
lint_buffer.buffer_lint(
lint::builtin::UNKNOWN_CRATE_TYPES,
ast::CRATE_NODE_ID,
span,
BuiltinLintDiag::UnknownCrateTypes { span, candidate },
);
}
} else {
validate_attr::emit_fatal_malformed_builtin_attribute(
&sess.psess,
a,
sym::crate_type,
);
}
}
}
}
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.dcx().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.dcx().emit_warn(errors::MultipleOutputTypesAdaption);
None
} else {
if !sess.opts.cg.extra_filename.is_empty() {
sess.dcx().emit_warn(errors::IgnoringExtraFilename);
}
Some(out_file.clone())
};
if sess.io.output_dir != None {
sess.dcx().emit_warn(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!()
}