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Diffstat (limited to 'compiler/rustc_interface/src/util.rs')
| -rw-r--r-- | compiler/rustc_interface/src/util.rs | 672 |
1 files changed, 672 insertions, 0 deletions
diff --git a/compiler/rustc_interface/src/util.rs b/compiler/rustc_interface/src/util.rs new file mode 100644 index 000000000..5e5596f13 --- /dev/null +++ b/compiler/rustc_interface/src/util.rs @@ -0,0 +1,672 @@ +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::jobserver; +use rustc_data_structures::sync::Lrc; +use rustc_errors::registry::Registry; +#[cfg(parallel_compiler)] +use rustc_middle::ty::tls; +use rustc_parse::validate_attr; +#[cfg(parallel_compiler)] +use rustc_query_impl::{QueryContext, QueryCtxt}; +use rustc_session as session; +use rustc_session::config::CheckCfg; +use rustc_session::config::{self, CrateType}; +use rustc_session::config::{ErrorOutputType, Input, OutputFilenames}; +use rustc_session::lint::{self, BuiltinLintDiagnostics, LintBuffer}; +use rustc_session::parse::CrateConfig; +use rustc_session::{early_error, filesearch, output, DiagnosticOutput, Session}; +use rustc_span::edition::Edition; +use rustc_span::lev_distance::find_best_match_for_name; +use rustc_span::source_map::FileLoader; +use rustc_span::symbol::{sym, Symbol}; +use std::env; +use std::env::consts::{DLL_PREFIX, DLL_SUFFIX}; +use std::mem; +#[cfg(not(parallel_compiler))] +use std::panic; +use std::path::{Path, PathBuf}; +use std::sync::atomic::{AtomicBool, Ordering}; +use std::sync::OnceLock; +use std::thread; +use tracing::info; + +/// Function pointer type that constructs a new CodegenBackend. +pub type MakeBackendFn = fn() -> Box<dyn CodegenBackend>; + +/// Adds `target_feature = "..."` cfgs for a variety of platform +/// specific features (SSE, NEON etc.). +/// +/// This is performed by checking whether a set of permitted features +/// is available on the target machine, by querying LLVM. +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( + sopts: config::Options, + cfg: FxHashSet<(String, Option<String>)>, + check_cfg: CheckCfg, + diagnostic_output: DiagnosticOutput, + file_loader: Option<Box<dyn FileLoader + Send + Sync + 'static>>, + input_path: Option<PathBuf>, + lint_caps: FxHashMap<lint::LintId, lint::Level>, + make_codegen_backend: Option< + Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>, + >, + descriptions: Registry, +) -> (Lrc<Session>, Lrc<Box<dyn CodegenBackend>>) { + let codegen_backend = if let Some(make_codegen_backend) = make_codegen_backend { + make_codegen_backend(&sopts) + } else { + get_codegen_backend( + &sopts.maybe_sysroot, + sopts.unstable_opts.codegen_backend.as_ref().map(|name| &name[..]), + ) + }; + + // target_override is documented to be called before init(), so this is okay + let target_override = codegen_backend.target_override(&sopts); + + let bundle = match rustc_errors::fluent_bundle( + sopts.maybe_sysroot.clone(), + sysroot_candidates(), + 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) => { + early_error(sopts.error_format, &format!("failed to load fluent bundle: {e}")); + } + }; + + let mut sess = session::build_session( + sopts, + input_path, + bundle, + descriptions, + diagnostic_output, + lint_caps, + file_loader, + target_override, + ); + + 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.parse_sess.config = cfg; + sess.parse_sess.check_config = check_cfg; + + (Lrc::new(sess), Lrc::new(codegen_backend)) +} + +const STACK_SIZE: usize = 8 * 1024 * 1024; + +fn get_stack_size() -> Option<usize> { + // FIXME: Hacks on hacks. If the env is trying to override the stack size + // then *don't* set it explicitly. + env::var_os("RUST_MIN_STACK").is_none().then_some(STACK_SIZE) +} + +/// Like a `thread::Builder::spawn` followed by a `join()`, but avoids the need +/// for `'static` bounds. +#[cfg(not(parallel_compiler))] +fn scoped_thread<F: FnOnce() -> R + Send, R: Send>(cfg: thread::Builder, f: F) -> R { + // SAFETY: join() is called immediately, so any closure captures are still + // alive. + match unsafe { cfg.spawn_unchecked(f) }.unwrap().join() { + Ok(v) => v, + Err(e) => panic::resume_unwind(e), + } +} + +#[cfg(not(parallel_compiler))] +pub fn run_in_thread_pool_with_globals<F: FnOnce() -> R + Send, R: Send>( + edition: Edition, + _threads: usize, + f: F, +) -> R { + let mut cfg = thread::Builder::new().name("rustc".to_string()); + + if let Some(size) = get_stack_size() { + cfg = cfg.stack_size(size); + } + + let main_handler = move || rustc_span::create_session_globals_then(edition, f); + + scoped_thread(cfg, main_handler) +} + +/// Creates a new thread and forwards information in thread locals to it. +/// The new thread runs the deadlock handler. +/// Must only be called when a deadlock is about to happen. +#[cfg(parallel_compiler)] +unsafe fn handle_deadlock() { + let registry = rustc_rayon_core::Registry::current(); + + let query_map = tls::with(|tcx| { + QueryCtxt::from_tcx(tcx) + .try_collect_active_jobs() + .expect("active jobs shouldn't be locked in deadlock handler") + }); + thread::spawn(move || rustc_query_impl::deadlock(query_map, ®istry)); +} + +#[cfg(parallel_compiler)] +pub fn run_in_thread_pool_with_globals<F: FnOnce() -> R + Send, R: Send>( + edition: Edition, + threads: usize, + f: F, +) -> R { + let mut config = 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(|| unsafe { handle_deadlock() }); + + if let Some(size) = get_stack_size() { + config = config.stack_size(size); + } + + let with_pool = move |pool: &rayon::ThreadPool| pool.install(f); + + rustc_span::create_session_globals_then(edition, || { + rustc_span::with_session_globals(|session_globals| { + // The main handler runs for each Rayon worker thread and sets up + // the thread local rustc uses. `session_globals` is captured and set + // on the new threads. + let main_handler = move |thread: rayon::ThreadBuilder| { + rustc_span::set_session_globals_then(session_globals, || thread.run()) + }; + + config.build_scoped(main_handler, with_pool).unwrap() + }) + }) +} + +fn load_backend_from_dylib(path: &Path) -> MakeBackendFn { + let lib = unsafe { Library::new(path) }.unwrap_or_else(|err| { + let err = format!("couldn't load codegen backend {:?}: {}", path, err); + early_error(ErrorOutputType::default(), &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); + early_error(ErrorOutputType::default(), &err); + }); + + // Intentionally leak the dynamic library. We can't ever unload it + // since the library can make things that will live arbitrarily long. + let backend_sym = unsafe { backend_sym.into_raw() }; + mem::forget(lib); + + *backend_sym +} + +/// Get the codegen backend based on the name and specified sysroot. +/// +/// A name of `None` indicates that the default backend should be used. +pub fn get_codegen_backend( + 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(filename.as_ref()), + #[cfg(feature = "llvm")] + "llvm" => rustc_codegen_llvm::LlvmCodegenBackend::new, + backend_name => get_codegen_sysroot(maybe_sysroot, backend_name), + } + }); + + // SAFETY: In case of a builtin codegen backend this is safe. In case of an external codegen + // backend we hope that the backend links against the same rustc_driver version. If this is not + // the case, we get UB. + unsafe { load() } +} + +// This is used for rustdoc, but it uses similar machinery to codegen backend +// loading, so we leave the code here. It is potentially useful for other tools +// that want to invoke the rustc binary while linking to rustc as well. +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_ref().map(|v| &**v) +} + +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 sysroot_candidates() -> Vec<PathBuf> { + let target = session::config::host_triple(); + let mut sysroot_candidates = vec![filesearch::get_or_default_sysroot()]; + let path = current_dll_path().and_then(|s| s.canonicalize().ok()); + if let Some(dll) = path { + // use `parent` twice to chop off the file name and then also the + // directory containing the dll which should be either `lib` or `bin`. + if let Some(path) = dll.parent().and_then(|p| p.parent()) { + // The original `path` pointed at the `rustc_driver` crate's dll. + // Now that dll should only be in one of two locations. The first is + // in the compiler's libdir, for example `$sysroot/lib/*.dll`. The + // other is the target's libdir, for example + // `$sysroot/lib/rustlib/$target/lib/*.dll`. + // + // We don't know which, so let's assume that if our `path` above + // ends in `$target` we *could* be in the target libdir, and always + // assume that we may be in the main libdir. + sysroot_candidates.push(path.to_owned()); + + if path.ends_with(target) { + sysroot_candidates.extend( + path.parent() // chop off `$target` + .and_then(|p| p.parent()) // chop off `rustlib` + .and_then(|p| p.parent()) // chop off `lib` + .map(|s| s.to_owned()), + ); + } + } + } + + return sysroot_candidates; + + #[cfg(unix)] + fn current_dll_path() -> Option<PathBuf> { + use std::ffi::{CStr, OsStr}; + use std::os::unix::prelude::*; + + unsafe { + let addr = current_dll_path as usize as *mut _; + let mut info = mem::zeroed(); + if libc::dladdr(addr, &mut info) == 0 { + info!("dladdr failed"); + return None; + } + if info.dli_fname.is_null() { + info!("dladdr returned null pointer"); + return None; + } + let bytes = CStr::from_ptr(info.dli_fname).to_bytes(); + let os = OsStr::from_bytes(bytes); + Some(PathBuf::from(os)) + } + } + + #[cfg(windows)] + fn current_dll_path() -> Option<PathBuf> { + use std::ffi::OsString; + use std::io; + use std::os::windows::prelude::*; + use std::ptr; + + use winapi::um::libloaderapi::{ + GetModuleFileNameW, GetModuleHandleExW, GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS, + }; + + unsafe { + let mut module = ptr::null_mut(); + let r = GetModuleHandleExW( + GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS, + current_dll_path as usize as *mut _, + &mut module, + ); + if r == 0 { + info!("GetModuleHandleExW failed: {}", io::Error::last_os_error()); + return None; + } + let mut space = Vec::with_capacity(1024); + let r = GetModuleFileNameW(module, space.as_mut_ptr(), space.capacity() as u32); + if r == 0 { + info!("GetModuleFileNameW failed: {}", io::Error::last_os_error()); + return None; + } + let r = r as usize; + if r >= space.capacity() { + info!("our buffer was too small? {}", io::Error::last_os_error()); + return None; + } + space.set_len(r); + let os = OsString::from_wide(&space); + Some(PathBuf::from(os)) + } + } +} + +fn get_codegen_sysroot(maybe_sysroot: &Option<PathBuf>, backend_name: &str) -> MakeBackendFn { + // For now we only allow this function to be called once as it'll dlopen a + // few things, which seems to work best if we only do that once. In + // general this assertion never trips due to the once guard in `get_codegen_backend`, + // but there's a few manual calls to this function in this file we protect + // against. + 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 + ); + early_error(ErrorOutputType::default(), &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_error(ErrorOutputType::default(), &err); + }); + + let mut file: Option<PathBuf> = None; + + let expected_names = &[ + format!("rustc_codegen_{}-{}", backend_name, release_str().expect("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_error(ErrorOutputType::default(), &err); + } + file = Some(path.clone()); + } + + match file { + Some(ref s) => load_backend_from_dylib(s), + None => { + let err = format!("unsupported builtin codegen backend `{}`", backend_name); + early_error(ErrorOutputType::default(), &err); + } + } +} + +pub(crate) fn check_attr_crate_type( + sess: &Session, + attrs: &[ast::Attribute], + lint_buffer: &mut LintBuffer, +) { + // Unconditionally collect crate types from attributes to make them used + 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 { + // This is here mainly to check for using a macro, such as + // #![crate_type = foo!()]. That is not supported since the + // crate type needs to be known very early in compilation long + // before expansion. Otherwise, validation would normally be + // caught in AstValidator (via `check_builtin_attribute`), but + // by the time that runs the macro is expanded, and it doesn't + // give an error. + 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> { + // Unconditionally collect crate types from attributes to make them used + 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 we're generating a test executable, then ignore all other output + // styles at all other locations + if session.opts.test { + return vec![CrateType::Executable]; + } + + // Only check command line flags if present. If no types are specified by + // command line, then reuse the empty `base` Vec to hold the types that + // will be found in crate attributes. + // JUSTIFICATION: before wrapper fn is available + #[cfg_attr(not(bootstrap), 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| { + let res = !output::invalid_output_for_target(session, *crate_type); + + if !res { + session.warn(&format!( + "dropping unsupported crate type `{}` for target `{}`", + *crate_type, session.opts.target_triple + )); + } + + res + }); + + base +} + +pub fn build_output_filenames( + input: &Input, + odir: &Option<PathBuf>, + ofile: &Option<PathBuf>, + temps_dir: &Option<PathBuf>, + attrs: &[ast::Attribute], + sess: &Session, +) -> OutputFilenames { + match *ofile { + None => { + // "-" as input file will cause the parser to read from stdin so we + // have to make up a name + // We want to toss everything after the final '.' + let dirpath = (*odir).as_ref().cloned().unwrap_or_default(); + + // If a crate name is present, we use it as the link name + let stem = sess + .opts + .crate_name + .clone() + .or_else(|| rustc_attr::find_crate_name(sess, attrs).map(|n| n.to_string())) + .unwrap_or_else(|| input.filestem().to_owned()); + + OutputFilenames::new( + dirpath, + stem, + None, + 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.warn( + "due to multiple output types requested, the explicitly specified \ + output file name will be adapted for each output type", + ); + None + } else { + if !sess.opts.cg.extra_filename.is_empty() { + sess.warn("ignoring -C extra-filename flag due to -o flag"); + } + Some(out_file.clone()) + }; + if *odir != None { + sess.warn("ignoring --out-dir flag due to -o flag"); + } + + OutputFilenames::new( + out_file.parent().unwrap_or_else(|| Path::new("")).to_path_buf(), + out_file.file_stem().unwrap_or_default().to_str().unwrap().to_string(), + ofile, + temps_dir.clone(), + sess.opts.cg.extra_filename.clone(), + sess.opts.output_types.clone(), + ) + } + } +} + +/// Returns a version string such as "1.46.0 (04488afe3 2020-08-24)" +pub fn version_str() -> Option<&'static str> { + option_env!("CFG_VERSION") +} + +/// Returns a version string such as "0.12.0-dev". +pub fn release_str() -> Option<&'static str> { + option_env!("CFG_RELEASE") +} + +/// Returns the full SHA1 hash of HEAD of the Git repo from which rustc was built. +pub fn commit_hash_str() -> Option<&'static str> { + option_env!("CFG_VER_HASH") +} + +/// Returns the "commit date" of HEAD of the Git repo from which rustc was built as a static string. +pub fn commit_date_str() -> Option<&'static str> { + option_env!("CFG_VER_DATE") +} |