use std::any::Any; use std::path::PathBuf; use std::str::FromStr; use std::sync::Arc; use std::sync::atomic::{AtomicBool, AtomicUsize}; use std::{env, io}; use rustc_data_structures::flock; use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet}; use rustc_data_structures::profiling::{SelfProfiler, SelfProfilerRef}; use rustc_data_structures::sync::{ AppendOnlyVec, DynSend, DynSync, Lock, MappedReadGuard, ReadGuard, RwLock, }; use rustc_errors::annotate_snippet_emitter_writer::AnnotateSnippetEmitter; use rustc_errors::codes::*; use rustc_errors::emitter::{DynEmitter, HumanReadableErrorType, OutputTheme, stderr_destination}; use rustc_errors::json::JsonEmitter; use rustc_errors::timings::TimingSectionHandler; use rustc_errors::{ Diag, DiagCtxt, DiagCtxtHandle, DiagMessage, Diagnostic, ErrorGuaranteed, FatalAbort, TerminalUrl, }; use rustc_feature::UnstableFeatures; use rustc_hir::limit::Limit; use rustc_macros::StableHash; pub use rustc_span::def_id::StableCrateId; use rustc_span::edition::Edition; use rustc_span::source_map::{FilePathMapping, SourceMap}; use rustc_span::{RealFileName, Span, Symbol}; use rustc_target::asm::InlineAsmArch; use rustc_target::spec::{ Arch, CodeModel, DebuginfoKind, Os, PanicStrategy, RelocModel, RelroLevel, SanitizerSet, SmallDataThresholdSupport, SplitDebuginfo, StackProtector, SymbolVisibility, Target, TargetTuple, TlsModel, apple, }; use crate::code_stats::CodeStats; pub use crate::code_stats::{DataTypeKind, FieldInfo, FieldKind, SizeKind, VariantInfo}; use crate::config::{ self, Cfg, CheckCfg, CoverageLevel, CoverageOptions, CrateType, DebugInfo, ErrorOutputType, FunctionReturn, Input, InstrumentCoverage, OptLevel, OutFileName, OutputType, SwitchWithOptPath, }; use crate::filesearch::FileSearch; use crate::lint::LintId; use crate::parse::ParseSess; use crate::search_paths::SearchPath; use crate::{errors, filesearch, lint}; /// The behavior of the CTFE engine when an error occurs with regards to backtraces. #[derive(Clone, Copy)] pub enum CtfeBacktrace { /// Do nothing special, return the error as usual without a backtrace. Disabled, /// Capture a backtrace at the point the error is created and return it in the error /// (to be printed later if/when the error ever actually gets shown to the user). Capture, /// Capture a backtrace at the point the error is created and immediately print it out. Immediate, } #[derive(Clone, Copy, Debug, StableHash)] pub struct Limits { /// The maximum recursion limit for potentially infinitely recursive /// operations such as auto-dereference and monomorphization. pub recursion_limit: Limit, /// The size at which the `large_assignments` lint starts /// being emitted. pub move_size_limit: Limit, /// The maximum length of types during monomorphization. pub type_length_limit: Limit, /// The maximum pattern complexity allowed (internal only). pub pattern_complexity_limit: Limit, } pub struct CompilerIO { pub input: Input, pub output_dir: Option, pub output_file: Option, pub temps_dir: Option, } pub trait DynLintStore: Any + DynSync + DynSend { /// Provides a way to access lint groups without depending on `rustc_lint` fn lint_groups_iter(&self) -> Box + '_>; } /// Represents the data associated with a compilation /// session for a single crate. pub struct Session { pub target: Target, pub host: Target, pub opts: config::Options, pub target_tlib_path: Arc, pub psess: ParseSess, pub unstable_features: UnstableFeatures, pub config: Cfg, pub check_config: CheckCfg, /// Spans passed to `proc_macro::quote_span`. Each span has a numerical /// identifier represented by its position in the vector. proc_macro_quoted_spans: AppendOnlyVec, /// Input, input file path and output file path to this compilation process. pub io: CompilerIO, incr_comp_session: RwLock, /// Used by `-Z self-profile`. pub prof: SelfProfilerRef, /// Used to emit section timings events (enabled by `--json=timings`). pub timings: TimingSectionHandler, /// Data about code being compiled, gathered during compilation. pub code_stats: CodeStats, /// This only ever stores a `LintStore` but we don't want a dependency on that type here. pub lint_store: Option>, /// Cap lint level specified by a driver specifically. pub driver_lint_caps: FxHashMap, /// Tracks the current behavior of the CTFE engine when an error occurs. /// Options range from returning the error without a backtrace to returning an error /// and immediately printing the backtrace to stderr. /// The `Lock` is only used by miri to allow setting `ctfe_backtrace` after analysis when /// `MIRI_BACKTRACE` is set. This makes it only apply to miri's errors and not to all CTFE /// errors. pub ctfe_backtrace: Lock, /// This tracks where `-Zunleash-the-miri-inside-of-you` was used to get around a /// const check, optionally with the relevant feature gate. We use this to /// warn about unleashing, but with a single diagnostic instead of dozens that /// drown everything else in noise. miri_unleashed_features: Lock)>>, /// Architecture to use for interpreting asm!. pub asm_arch: Option, /// Set of enabled features for the current target. pub target_features: FxIndexSet, /// Set of enabled features for the current target, including unstable ones. pub unstable_target_features: FxIndexSet, /// The version of the rustc process, possibly including a commit hash and description. pub cfg_version: &'static str, /// The inner atomic value is set to true when a feature marked as `internal` is /// enabled. Makes it so that "please report a bug" is hidden, as ICEs with /// internal features are wontfix, and they are usually the cause of the ICEs. /// None signifies that this is not tracked. pub using_internal_features: &'static AtomicBool, /// Environment variables accessed during the build and their values when they exist. pub env_depinfo: Lock)>>, /// File paths accessed during the build. pub file_depinfo: Lock>, target_filesearch: FileSearch, host_filesearch: FileSearch, /// The names of intrinsics that the current codegen backend replaces /// with its own implementations. pub replaced_intrinsics: FxHashSet, /// Does the codegen backend support ThinLTO? pub thin_lto_supported: bool, /// Global per-session counter for MIR optimization pass applications. /// /// Used by `-Zmir-opt-bisect-limit` to assign an index to each /// optimization-pass execution candidate during this compilation. pub mir_opt_bisect_eval_count: AtomicUsize, /// Enabled features that are used in the current compilation. /// /// The value is the `DepNodeIndex` of the node encodes the used feature. pub used_features: Lock>, } #[derive(Clone, Copy)] pub enum CodegenUnits { /// Specified by the user. In this case we try fairly hard to produce the /// number of CGUs requested. User(usize), /// A default value, i.e. not specified by the user. In this case we take /// more liberties about CGU formation, e.g. avoid producing very small /// CGUs. Default(usize), } impl CodegenUnits { pub fn as_usize(self) -> usize { match self { CodegenUnits::User(n) => n, CodegenUnits::Default(n) => n, } } } pub struct LintGroup { pub name: &'static str, pub lints: Vec, pub is_externally_loaded: bool, } impl Session { pub fn miri_unleashed_feature(&self, span: Span, feature_gate: Option) { self.miri_unleashed_features.lock().push((span, feature_gate)); } pub fn local_crate_source_file(&self) -> Option { Some( self.source_map() .path_mapping() .to_real_filename(self.source_map().working_dir(), self.io.input.opt_path()?), ) } fn check_miri_unleashed_features(&self) -> Option { let mut guar = None; let unleashed_features = self.miri_unleashed_features.lock(); if !unleashed_features.is_empty() { let mut must_err = false; // Create a diagnostic pointing at where things got unleashed. self.dcx().emit_warn(errors::SkippingConstChecks { unleashed_features: unleashed_features .iter() .map(|(span, gate)| { gate.map(|gate| { must_err = true; errors::UnleashedFeatureHelp::Named { span: *span, gate } }) .unwrap_or(errors::UnleashedFeatureHelp::Unnamed { span: *span }) }) .collect(), }); // If we should err, make sure we did. if must_err && self.dcx().has_errors().is_none() { // We have skipped a feature gate, and not run into other errors... reject. guar = Some(self.dcx().emit_err(errors::NotCircumventFeature)); } } guar } /// Invoked all the way at the end to finish off diagnostics printing. pub fn finish_diagnostics(&self) -> Option { let mut guar = None; guar = guar.or(self.check_miri_unleashed_features()); guar = guar.or(self.dcx().emit_stashed_diagnostics()); self.dcx().print_error_count(); if self.opts.json_future_incompat { self.dcx().emit_future_breakage_report(); } guar } /// Returns true if the crate is a testing one. pub fn is_test_crate(&self) -> bool { self.opts.test } /// `feature` must be a language feature. #[track_caller] pub fn create_feature_err<'a>(&'a self, err: impl Diagnostic<'a>, feature: Symbol) -> Diag<'a> { let mut err = self.dcx().create_err(err); if err.code.is_none() { err.code(E0658); } errors::add_feature_diagnostics(&mut err, self, feature); err } /// Record the fact that we called `trimmed_def_paths`, and do some /// checking about whether its cost was justified. pub fn record_trimmed_def_paths(&self) { if self.opts.unstable_opts.print_type_sizes || self.opts.unstable_opts.query_dep_graph || self.opts.unstable_opts.dump_mir.is_some() || self.opts.unstable_opts.unpretty.is_some() || self.prof.is_args_recording_enabled() || self.opts.output_types.contains_key(&OutputType::Mir) || std::env::var_os("RUSTC_LOG").is_some() { return; } self.dcx().set_must_produce_diag() } #[inline] pub fn dcx(&self) -> DiagCtxtHandle<'_> { self.psess.dcx() } #[inline] pub fn source_map(&self) -> &SourceMap { self.psess.source_map() } pub fn proc_macro_quoted_spans(&self) -> impl Iterator { // This is equivalent to `.iter().copied().enumerate()`, but that isn't possible for // AppendOnlyVec, so we resort to this scheme. self.proc_macro_quoted_spans.iter_enumerated() } pub fn save_proc_macro_span(&self, span: Span) -> usize { self.proc_macro_quoted_spans.push(span) } /// Returns `true` if internal lints should be added to the lint store - i.e. if /// `-Zunstable-options` is provided and this isn't rustdoc (internal lints can trigger errors /// to be emitted under rustdoc). pub fn enable_internal_lints(&self) -> bool { self.unstable_options() && !self.opts.actually_rustdoc } pub fn instrument_coverage(&self) -> bool { self.opts.cg.instrument_coverage() != InstrumentCoverage::No } pub fn instrument_coverage_branch(&self) -> bool { self.instrument_coverage() && self.opts.unstable_opts.coverage_options.level >= CoverageLevel::Branch } pub fn instrument_coverage_condition(&self) -> bool { self.instrument_coverage() && self.opts.unstable_opts.coverage_options.level >= CoverageLevel::Condition } /// Provides direct access to the `CoverageOptions` struct, so that /// individual flags for debugging/testing coverage instrumetation don't /// need separate accessors. pub fn coverage_options(&self) -> &CoverageOptions { &self.opts.unstable_opts.coverage_options } pub fn is_sanitizer_cfi_enabled(&self) -> bool { self.sanitizers().contains(SanitizerSet::CFI) } pub fn is_sanitizer_cfi_canonical_jump_tables_disabled(&self) -> bool { self.opts.unstable_opts.sanitizer_cfi_canonical_jump_tables == Some(false) } pub fn is_sanitizer_cfi_canonical_jump_tables_enabled(&self) -> bool { self.opts.unstable_opts.sanitizer_cfi_canonical_jump_tables == Some(true) } pub fn is_sanitizer_cfi_generalize_pointers_enabled(&self) -> bool { self.opts.unstable_opts.sanitizer_cfi_generalize_pointers == Some(true) } pub fn is_sanitizer_cfi_normalize_integers_enabled(&self) -> bool { self.opts.unstable_opts.sanitizer_cfi_normalize_integers == Some(true) } pub fn is_sanitizer_kcfi_arity_enabled(&self) -> bool { self.opts.unstable_opts.sanitizer_kcfi_arity == Some(true) } pub fn is_sanitizer_kcfi_enabled(&self) -> bool { self.sanitizers().contains(SanitizerSet::KCFI) } pub fn is_split_lto_unit_enabled(&self) -> bool { self.opts.unstable_opts.split_lto_unit == Some(true) } /// Check whether this compile session and crate type use static crt. pub fn crt_static(&self, crate_type: Option) -> bool { if !self.target.crt_static_respected { // If the target does not opt in to crt-static support, use its default. return self.target.crt_static_default; } let requested_features = self.opts.cg.target_feature.split(','); let found_negative = requested_features.clone().any(|r| r == "-crt-static"); let found_positive = requested_features.clone().any(|r| r == "+crt-static"); // JUSTIFICATION: necessary use of crate_types directly (see FIXME below) #[allow(rustc::bad_opt_access)] if found_positive || found_negative { found_positive } else if crate_type == Some(CrateType::ProcMacro) || crate_type == None && self.opts.crate_types.contains(&CrateType::ProcMacro) { // FIXME: When crate_type is not available, // we use compiler options to determine the crate_type. // We can't check `#![crate_type = "proc-macro"]` here. false } else { self.target.crt_static_default } } pub fn is_wasi_reactor(&self) -> bool { self.target.options.os == Os::Wasi && matches!( self.opts.unstable_opts.wasi_exec_model, Some(config::WasiExecModel::Reactor) ) } /// Returns `true` if the target can use the current split debuginfo configuration. pub fn target_can_use_split_dwarf(&self) -> bool { self.target.debuginfo_kind == DebuginfoKind::Dwarf } pub fn generate_proc_macro_decls_symbol(&self, stable_crate_id: StableCrateId) -> String { format!("__rustc_proc_macro_decls_{:08x}__", stable_crate_id.as_u64()) } pub fn target_filesearch(&self) -> &filesearch::FileSearch { &self.target_filesearch } pub fn host_filesearch(&self) -> &filesearch::FileSearch { &self.host_filesearch } /// Returns a list of directories where target-specific tool binaries are located. Some fallback /// directories are also returned, for example if `--sysroot` is used but tools are missing /// (#125246): we also add the bin directories to the sysroot where rustc is located. pub fn get_tools_search_paths(&self, self_contained: bool) -> Vec { let search_paths = self .opts .sysroot .all_paths() .map(|sysroot| filesearch::make_target_bin_path(&sysroot, config::host_tuple())); if self_contained { // The self-contained tools are expected to be e.g. in `bin/self-contained` in the // sysroot's `rustlib` path, so we add such a subfolder to the bin path, and the // fallback paths. search_paths.flat_map(|path| [path.clone(), path.join("self-contained")]).collect() } else { search_paths.collect() } } pub fn init_incr_comp_session(&self, session_dir: PathBuf, lock_file: flock::Lock) { let mut incr_comp_session = self.incr_comp_session.borrow_mut(); if let IncrCompSession::NotInitialized = *incr_comp_session { } else { panic!("Trying to initialize IncrCompSession `{:?}`", *incr_comp_session) } *incr_comp_session = IncrCompSession::Active { session_directory: session_dir, _lock_file: lock_file }; } pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) { let mut incr_comp_session = self.incr_comp_session.borrow_mut(); if let IncrCompSession::Active { .. } = *incr_comp_session { } else { panic!("trying to finalize `IncrCompSession` `{:?}`", *incr_comp_session); } // Note: this will also drop the lock file, thus unlocking the directory. *incr_comp_session = IncrCompSession::Finalized { session_directory: new_directory_path }; } pub fn mark_incr_comp_session_as_invalid(&self) { let mut incr_comp_session = self.incr_comp_session.borrow_mut(); let session_directory = match *incr_comp_session { IncrCompSession::Active { ref session_directory, .. } => session_directory.clone(), IncrCompSession::InvalidBecauseOfErrors { .. } => return, _ => panic!("trying to invalidate `IncrCompSession` `{:?}`", *incr_comp_session), }; // Note: this will also drop the lock file, thus unlocking the directory. *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors { session_directory }; } pub fn incr_comp_session_dir(&self) -> MappedReadGuard<'_, PathBuf> { let incr_comp_session = self.incr_comp_session.borrow(); ReadGuard::map(incr_comp_session, |incr_comp_session| match *incr_comp_session { IncrCompSession::NotInitialized => panic!( "trying to get session directory from `IncrCompSession`: {:?}", *incr_comp_session, ), IncrCompSession::Active { ref session_directory, .. } | IncrCompSession::Finalized { ref session_directory } | IncrCompSession::InvalidBecauseOfErrors { ref session_directory } => { session_directory } }) } pub fn incr_comp_session_dir_opt(&self) -> Option> { self.opts.incremental.as_ref().map(|_| self.incr_comp_session_dir()) } /// Is this edition 2015? pub fn is_rust_2015(&self) -> bool { self.edition().is_rust_2015() } /// Are we allowed to use features from the Rust 2018 edition? pub fn at_least_rust_2018(&self) -> bool { self.edition().at_least_rust_2018() } /// Are we allowed to use features from the Rust 2021 edition? pub fn at_least_rust_2021(&self) -> bool { self.edition().at_least_rust_2021() } /// Are we allowed to use features from the Rust 2024 edition? pub fn at_least_rust_2024(&self) -> bool { self.edition().at_least_rust_2024() } /// Returns `true` if we should use the PLT for shared library calls. pub fn needs_plt(&self) -> bool { // Check if the current target usually wants PLT to be enabled. // The user can use the command line flag to override it. let want_plt = self.target.plt_by_default; let dbg_opts = &self.opts.unstable_opts; let relro_level = self.opts.cg.relro_level.unwrap_or(self.target.relro_level); // Only enable this optimization by default if full relro is also enabled. // In this case, lazy binding was already unavailable, so nothing is lost. // This also ensures `-Wl,-z,now` is supported by the linker. let full_relro = RelroLevel::Full == relro_level; // If user didn't explicitly forced us to use / skip the PLT, // then use it unless the target doesn't want it by default or the full relro forces it on. dbg_opts.plt.unwrap_or(want_plt || !full_relro) } /// Checks if LLVM lifetime markers should be emitted. pub fn emit_lifetime_markers(&self) -> bool { self.opts.optimize != config::OptLevel::No // AddressSanitizer and KernelAddressSanitizer uses lifetimes to detect use after scope bugs. // // MemorySanitizer uses lifetimes to detect use of uninitialized stack variables. // // HWAddressSanitizer and KernelHWAddressSanitizer will use lifetimes to detect use after // scope bugs in the future. || self.sanitizers().intersects(SanitizerSet::ADDRESS | SanitizerSet::KERNELADDRESS | SanitizerSet::MEMORY | SanitizerSet::HWADDRESS | SanitizerSet::KERNELHWADDRESS) } pub fn diagnostic_width(&self) -> usize { let default_column_width = 140; if let Some(width) = self.opts.diagnostic_width { width } else if self.opts.unstable_opts.ui_testing { default_column_width } else { termize::dimensions().map_or(default_column_width, |(w, _)| w) } } /// Returns the default symbol visibility. pub fn default_visibility(&self) -> SymbolVisibility { self.opts .unstable_opts .default_visibility .or(self.target.options.default_visibility) .unwrap_or(SymbolVisibility::Interposable) } pub fn staticlib_components(&self, verbatim: bool) -> (&str, &str) { if verbatim { ("", "") } else { (&*self.target.staticlib_prefix, &*self.target.staticlib_suffix) } } pub fn lint_groups_iter(&self) -> Box + '_> { match self.lint_store { Some(ref lint_store) => lint_store.lint_groups_iter(), None => Box::new(std::iter::empty()), } } } // JUSTIFICATION: defn of the suggested wrapper fns #[allow(rustc::bad_opt_access)] impl Session { pub fn verbose_internals(&self) -> bool { self.opts.unstable_opts.verbose_internals } pub fn print_llvm_stats(&self) -> bool { self.opts.unstable_opts.print_codegen_stats } pub fn print_llvm_stats_json(&self) -> Option<&String> { self.opts.unstable_opts.print_codegen_stats_json.as_ref() } pub fn verify_llvm_ir(&self) -> bool { self.opts.unstable_opts.verify_llvm_ir || option_env!("RUSTC_VERIFY_LLVM_IR").is_some() } pub fn binary_dep_depinfo(&self) -> bool { self.opts.unstable_opts.binary_dep_depinfo } pub fn mir_opt_level(&self) -> usize { self.opts .unstable_opts .mir_opt_level .unwrap_or_else(|| if self.opts.optimize != OptLevel::No { 2 } else { 1 }) } /// Calculates the flavor of LTO to use for this compilation. pub fn lto(&self) -> config::Lto { // If our target has codegen requirements ignore the command line if self.target.requires_lto { return config::Lto::Fat; } // If the user specified something, return that. If they only said `-C // lto` and we've for whatever reason forced off ThinLTO via the CLI, // then ensure we can't use a ThinLTO. match self.opts.cg.lto { config::LtoCli::Unspecified => { // The compiler was invoked without the `-Clto` flag. Fall // through to the default handling } config::LtoCli::No => { // The user explicitly opted out of any kind of LTO return config::Lto::No; } config::LtoCli::Yes | config::LtoCli::Fat | config::LtoCli::NoParam => { // All of these mean fat LTO return config::Lto::Fat; } config::LtoCli::Thin => { // The user explicitly asked for ThinLTO if !self.thin_lto_supported { // Backend doesn't support ThinLTO, fallback to fat LTO. self.dcx().emit_warn(errors::ThinLtoNotSupportedByBackend); return config::Lto::Fat; } return config::Lto::Thin; } } if !self.thin_lto_supported { return config::Lto::No; } // Ok at this point the target doesn't require anything and the user // hasn't asked for anything. Our next decision is whether or not // we enable "auto" ThinLTO where we use multiple codegen units and // then do ThinLTO over those codegen units. The logic below will // either return `No` or `ThinLocal`. // If processing command line options determined that we're incompatible // with ThinLTO (e.g., `-C lto --emit llvm-ir`) then return that option. if self.opts.cli_forced_local_thinlto_off { return config::Lto::No; } // If `-Z thinlto` specified process that, but note that this is mostly // a deprecated option now that `-C lto=thin` exists. if let Some(enabled) = self.opts.unstable_opts.thinlto { if enabled { return config::Lto::ThinLocal; } else { return config::Lto::No; } } // If there's only one codegen unit and LTO isn't enabled then there's // no need for ThinLTO so just return false. if self.codegen_units().as_usize() == 1 { return config::Lto::No; } // Now we're in "defaults" territory. By default we enable ThinLTO for // optimized compiles (anything greater than O0). match self.opts.optimize { config::OptLevel::No => config::Lto::No, _ => config::Lto::ThinLocal, } } /// Returns the panic strategy for this compile session. If the user explicitly selected one /// using '-C panic', use that, otherwise use the panic strategy defined by the target. pub fn panic_strategy(&self) -> PanicStrategy { self.opts.cg.panic.unwrap_or(self.target.panic_strategy) } pub fn fewer_names(&self) -> bool { if let Some(fewer_names) = self.opts.unstable_opts.fewer_names { fewer_names } else { let more_names = self.opts.output_types.contains_key(&OutputType::LlvmAssembly) || self.opts.output_types.contains_key(&OutputType::Bitcode) // AddressSanitizer and MemorySanitizer use alloca name when reporting an issue. || self.opts.unstable_opts.sanitizer.intersects(SanitizerSet::ADDRESS | SanitizerSet::MEMORY); !more_names } } pub fn unstable_options(&self) -> bool { self.opts.unstable_opts.unstable_options } pub fn is_nightly_build(&self) -> bool { self.opts.unstable_features.is_nightly_build() } pub fn overflow_checks(&self) -> bool { self.opts.cg.overflow_checks.unwrap_or(self.opts.debug_assertions) } pub fn ub_checks(&self) -> bool { self.opts.unstable_opts.ub_checks.unwrap_or(self.opts.debug_assertions) } pub fn contract_checks(&self) -> bool { self.opts.unstable_opts.contract_checks.unwrap_or(false) } pub fn relocation_model(&self) -> RelocModel { self.opts.cg.relocation_model.unwrap_or(self.target.relocation_model) } pub fn code_model(&self) -> Option { self.opts.cg.code_model.or(self.target.code_model) } pub fn tls_model(&self) -> TlsModel { self.opts.unstable_opts.tls_model.unwrap_or(self.target.tls_model) } pub fn direct_access_external_data(&self) -> Option { self.opts .unstable_opts .direct_access_external_data .or(self.target.direct_access_external_data) } pub fn split_debuginfo(&self) -> SplitDebuginfo { self.opts.cg.split_debuginfo.unwrap_or(self.target.split_debuginfo) } /// Returns the DWARF version passed on the CLI or the default for the target. pub fn dwarf_version(&self) -> u32 { self.opts .cg .dwarf_version .or(self.opts.unstable_opts.dwarf_version) .unwrap_or(self.target.default_dwarf_version) } pub fn stack_protector(&self) -> StackProtector { if self.target.options.supports_stack_protector { self.opts.unstable_opts.stack_protector } else { StackProtector::None } } pub fn must_emit_unwind_tables(&self) -> bool { // This is used to control the emission of the `uwtable` attribute on // LLVM functions. The `uwtable` attribute according to LLVM is: // // This attribute indicates that the ABI being targeted requires that an // unwind table entry be produced for this function even if we can show // that no exceptions passes by it. This is normally the case for the // ELF x86-64 abi, but it can be disabled for some compilation units. // // Typically when we're compiling with `-C panic=abort` we don't need // `uwtable` because we can't generate any exceptions! But note that // some targets require unwind tables to generate backtraces. // Unwind tables are needed when compiling with `-C panic=unwind`, but // LLVM won't omit unwind tables unless the function is also marked as // `nounwind`, so users are allowed to disable `uwtable` emission. // Historically rustc always emits `uwtable` attributes by default, so // even they can be disabled, they're still emitted by default. // // On some targets (including windows), however, exceptions include // other events such as illegal instructions, segfaults, etc. This means // that on Windows we end up still needing unwind tables even if the `-C // panic=abort` flag is passed. // // You can also find more info on why Windows needs unwind tables in: // https://bugzilla.mozilla.org/show_bug.cgi?id=1302078 // // If a target requires unwind tables, then they must be emitted. // Otherwise, we can defer to the `-C force-unwind-tables=` // value, if it is provided, or disable them, if not. self.target.requires_uwtable || self .opts .cg .force_unwind_tables .unwrap_or(self.panic_strategy().unwinds() || self.target.default_uwtable) } /// Returns the number of threads used for the thread pool. /// /// `None` means thread pool is not used and synchronization is disabled. /// `Some(n)` means synchronization is enabled with `n` worker threads. #[inline] pub fn threads(&self) -> Option { self.opts.unstable_opts.threads } /// Returns the number of codegen units that should be used for this /// compilation pub fn codegen_units(&self) -> CodegenUnits { if let Some(n) = self.opts.cli_forced_codegen_units { return CodegenUnits::User(n); } if let Some(n) = self.target.default_codegen_units { return CodegenUnits::Default(n as usize); } // If incremental compilation is turned on, we default to a high number // codegen units in order to reduce the "collateral damage" small // changes cause. if self.opts.incremental.is_some() { return CodegenUnits::Default(256); } // Why is 16 codegen units the default all the time? // // The main reason for enabling multiple codegen units by default is to // leverage the ability for the codegen backend to do codegen and // optimization in parallel. This allows us, especially for large crates, to // make good use of all available resources on the machine once we've // hit that stage of compilation. Large crates especially then often // take a long time in codegen/optimization and this helps us amortize that // cost. // // Note that a high number here doesn't mean that we'll be spawning a // large number of threads in parallel. The backend of rustc contains // global rate limiting through the `jobserver` crate so we'll never // overload the system with too much work, but rather we'll only be // optimizing when we're otherwise cooperating with other instances of // rustc. // // Rather a high number here means that we should be able to keep a lot // of idle cpus busy. By ensuring that no codegen unit takes *too* long // to build we'll be guaranteed that all cpus will finish pretty closely // to one another and we should make relatively optimal use of system // resources // // Note that the main cost of codegen units is that it prevents LLVM // from inlining across codegen units. Users in general don't have a lot // of control over how codegen units are split up so it's our job in the // compiler to ensure that undue performance isn't lost when using // codegen units (aka we can't require everyone to slap `#[inline]` on // everything). // // If we're compiling at `-O0` then the number doesn't really matter too // much because performance doesn't matter and inlining is ok to lose. // In debug mode we just want to try to guarantee that no cpu is stuck // doing work that could otherwise be farmed to others. // // In release mode, however (O1 and above) performance does indeed // matter! To recover the loss in performance due to inlining we'll be // enabling ThinLTO by default (the function for which is just below). // This will ensure that we recover any inlining wins we otherwise lost // through codegen unit partitioning. // // --- // // Ok that's a lot of words but the basic tl;dr; is that we want a high // number here -- but not too high. Additionally we're "safe" to have it // always at the same number at all optimization levels. // // As a result 16 was chosen here! Mostly because it was a power of 2 // and most benchmarks agreed it was roughly a local optimum. Not very // scientific. CodegenUnits::Default(16) } pub fn teach(&self, code: ErrCode) -> bool { self.opts.unstable_opts.teach && self.dcx().must_teach(code) } pub fn edition(&self) -> Edition { self.opts.edition } pub fn link_dead_code(&self) -> bool { self.opts.cg.link_dead_code.unwrap_or(false) } /// Get the deployment target on Apple platforms based on the standard environment variables, /// or fall back to the minimum version supported by `rustc`. /// /// This should be guarded behind `if sess.target.is_like_darwin`. pub fn apple_deployment_target(&self) -> apple::OSVersion { let min = apple::OSVersion::minimum_deployment_target(&self.target); let env_var = apple::deployment_target_env_var(&self.target.os); // FIXME(madsmtm): Track changes to this. if let Ok(deployment_target) = env::var(env_var) { match apple::OSVersion::from_str(&deployment_target) { Ok(version) => { let os_min = apple::OSVersion::os_minimum_deployment_target(&self.target.os); // It is common that the deployment target is set a bit too low, for example on // macOS Aarch64 to also target older x86_64. So we only want to warn when variable // is lower than the minimum OS supported by rustc, not when the variable is lower // than the minimum for a specific target. if version < os_min { self.dcx().emit_warn(errors::AppleDeploymentTarget::TooLow { env_var, version: version.fmt_pretty().to_string(), os_min: os_min.fmt_pretty().to_string(), }); } // Raise the deployment target to the minimum supported. version.max(min) } Err(error) => { self.dcx().emit_err(errors::AppleDeploymentTarget::Invalid { env_var, error }); min } } } else { // If no deployment target variable is set, default to the minimum found above. min } } pub fn sanitizers(&self) -> SanitizerSet { return self.opts.unstable_opts.sanitizer | self.target.options.default_sanitizers; } } // JUSTIFICATION: part of session construction #[allow(rustc::bad_opt_access)] fn default_emitter(sopts: &config::Options, source_map: Arc) -> Box { let macro_backtrace = sopts.unstable_opts.macro_backtrace; let track_diagnostics = sopts.unstable_opts.track_diagnostics; let terminal_url = match sopts.unstable_opts.terminal_urls { TerminalUrl::Auto => { match (std::env::var("COLORTERM").as_deref(), std::env::var("TERM").as_deref()) { (Ok("truecolor"), Ok("xterm-256color")) if sopts.unstable_features.is_nightly_build() => { TerminalUrl::Yes } _ => TerminalUrl::No, } } t => t, }; let source_map = if sopts.unstable_opts.link_only { None } else { Some(source_map) }; match sopts.error_format { config::ErrorOutputType::HumanReadable { kind, color_config } => match kind { HumanReadableErrorType { short, unicode } => { let emitter = AnnotateSnippetEmitter::new(stderr_destination(color_config)) .sm(source_map) .short_message(short) .diagnostic_width(sopts.diagnostic_width) .macro_backtrace(macro_backtrace) .track_diagnostics(track_diagnostics) .terminal_url(terminal_url) .theme(if unicode { OutputTheme::Unicode } else { OutputTheme::Ascii }) .ignored_directories_in_source_blocks( sopts.unstable_opts.ignore_directory_in_diagnostics_source_blocks.clone(), ); Box::new(emitter.ui_testing(sopts.unstable_opts.ui_testing)) } }, config::ErrorOutputType::Json { pretty, json_rendered, color_config } => Box::new( JsonEmitter::new( Box::new(io::BufWriter::new(io::stderr())), source_map, pretty, json_rendered, color_config, ) .ui_testing(sopts.unstable_opts.ui_testing) .ignored_directories_in_source_blocks( sopts.unstable_opts.ignore_directory_in_diagnostics_source_blocks.clone(), ) .diagnostic_width(sopts.diagnostic_width) .macro_backtrace(macro_backtrace) .track_diagnostics(track_diagnostics) .terminal_url(terminal_url), ), } } // JUSTIFICATION: literally session construction #[allow(rustc::bad_opt_access)] pub fn build_session( sopts: config::Options, io: CompilerIO, driver_lint_caps: FxHashMap, target: Target, cfg_version: &'static str, ice_file: Option, using_internal_features: &'static AtomicBool, ) -> Session { // FIXME: This is not general enough to make the warning lint completely override // normal diagnostic warnings, since the warning lint can also be denied and changed // later via the source code. let warnings_allow = sopts .lint_opts .iter() .rfind(|&(key, _)| *key == "warnings") .is_some_and(|&(_, level)| level == lint::Allow); let cap_lints_allow = sopts.lint_cap.is_some_and(|cap| cap == lint::Allow); let can_emit_warnings = !(warnings_allow || cap_lints_allow); let source_map = rustc_span::source_map::get_source_map().unwrap(); let emitter = default_emitter(&sopts, Arc::clone(&source_map)); let mut dcx = DiagCtxt::new(emitter).with_flags(sopts.unstable_opts.dcx_flags(can_emit_warnings)); if let Some(ice_file) = ice_file { dcx = dcx.with_ice_file(ice_file); } let host_triple = TargetTuple::from_tuple(config::host_tuple()); let (host, target_warnings) = Target::search(&host_triple, sopts.sysroot.path(), sopts.unstable_opts.unstable_options) .unwrap_or_else(|e| { dcx.handle().fatal(format!("Error loading host specification: {e}")) }); for warning in target_warnings.warning_messages() { dcx.handle().warn(warning) } let self_profiler = if let SwitchWithOptPath::Enabled(ref d) = sopts.unstable_opts.self_profile { let directory = if let Some(directory) = d { directory } else { std::path::Path::new(".") }; let profiler = SelfProfiler::new( directory, sopts.crate_name.as_deref(), sopts.unstable_opts.self_profile_events.as_deref(), &sopts.unstable_opts.self_profile_counter, ); match profiler { Ok(profiler) => Some(Arc::new(profiler)), Err(e) => { dcx.handle().emit_warn(errors::FailedToCreateProfiler { err: e.to_string() }); None } } } else { None }; let psess = ParseSess::with_dcx(dcx, source_map); let host_triple = config::host_tuple(); let target_triple = sopts.target_triple.tuple(); // FIXME use host sysroot? let host_tlib_path = Arc::new(SearchPath::from_sysroot_and_triple(sopts.sysroot.path(), host_triple)); let target_tlib_path = if host_triple == target_triple { // Use the same `SearchPath` if host and target triple are identical to avoid unnecessary // rescanning of the target lib path and an unnecessary allocation. Arc::clone(&host_tlib_path) } else { Arc::new(SearchPath::from_sysroot_and_triple(sopts.sysroot.path(), target_triple)) }; let prof = SelfProfilerRef::new( self_profiler, sopts.unstable_opts.time_passes.then(|| sopts.unstable_opts.time_passes_format), ); let ctfe_backtrace = Lock::new(match env::var("RUSTC_CTFE_BACKTRACE") { Ok(ref val) if val == "immediate" => CtfeBacktrace::Immediate, Ok(ref val) if val != "0" => CtfeBacktrace::Capture, _ => CtfeBacktrace::Disabled, }); let asm_arch = if target.allow_asm { InlineAsmArch::from_arch(&target.arch) } else { None }; let target_filesearch = filesearch::FileSearch::new(&sopts.search_paths, &target_tlib_path, &target); let host_filesearch = filesearch::FileSearch::new(&sopts.search_paths, &host_tlib_path, &host); let timings = TimingSectionHandler::new(sopts.json_timings); let sess = Session { target, host, opts: sopts, target_tlib_path, psess, unstable_features: UnstableFeatures::from_environment(None), config: Cfg::default(), check_config: CheckCfg::default(), proc_macro_quoted_spans: Default::default(), io, incr_comp_session: RwLock::new(IncrCompSession::NotInitialized), prof, timings, code_stats: Default::default(), lint_store: None, driver_lint_caps, ctfe_backtrace, miri_unleashed_features: Lock::new(Default::default()), asm_arch, target_features: Default::default(), unstable_target_features: Default::default(), cfg_version, using_internal_features, env_depinfo: Default::default(), file_depinfo: Default::default(), target_filesearch, host_filesearch, replaced_intrinsics: FxHashSet::default(), // filled by `run_compiler` thin_lto_supported: true, // filled by `run_compiler` mir_opt_bisect_eval_count: AtomicUsize::new(0), used_features: Lock::default(), }; validate_commandline_args_with_session_available(&sess); sess } /// Validate command line arguments with a `Session`. /// /// If it is useful to have a Session available already for validating a commandline argument, you /// can do so here. // JUSTIFICATION: needs to access args to validate them #[allow(rustc::bad_opt_access)] fn validate_commandline_args_with_session_available(sess: &Session) { // Since we don't know if code in an rlib will be linked to statically or // dynamically downstream, rustc generates `__imp_` symbols that help linkers // on Windows deal with this lack of knowledge (#27438). Unfortunately, // these manually generated symbols confuse LLD when it tries to merge // bitcode during ThinLTO. Therefore we disallow dynamic linking on Windows // when compiling for LLD ThinLTO. This way we can validly just not generate // the `dllimport` attributes and `__imp_` symbols in that case. if sess.opts.cg.linker_plugin_lto.enabled() && sess.opts.cg.prefer_dynamic && sess.target.is_like_windows { sess.dcx().emit_err(errors::LinkerPluginToWindowsNotSupported); } // Make sure that any given profiling data actually exists so LLVM can't // decide to silently skip PGO. if let Some(ref path) = sess.opts.cg.profile_use { if !path.exists() { sess.dcx().emit_err(errors::ProfileUseFileDoesNotExist { path }); } } // Do the same for sample profile data. if let Some(ref path) = sess.opts.unstable_opts.profile_sample_use { if !path.exists() { sess.dcx().emit_err(errors::ProfileSampleUseFileDoesNotExist { path }); } } // Unwind tables cannot be disabled if the target requires them. if let Some(include_uwtables) = sess.opts.cg.force_unwind_tables { if sess.target.requires_uwtable && !include_uwtables { sess.dcx().emit_err(errors::TargetRequiresUnwindTables); } } // Sanitizers can only be used on platforms that we know have working sanitizer codegen. let supported_sanitizers = sess.target.options.supported_sanitizers; let mut unsupported_sanitizers = sess.opts.unstable_opts.sanitizer - supported_sanitizers; // Niche: if `fixed-x18`, or effectively switching on `reserved-x18` flag, is enabled // we should allow Shadow Call Stack sanitizer. if sess.opts.unstable_opts.fixed_x18 && sess.target.arch == Arch::AArch64 { unsupported_sanitizers -= SanitizerSet::SHADOWCALLSTACK; } match unsupported_sanitizers.into_iter().count() { 0 => {} 1 => { sess.dcx() .emit_err(errors::SanitizerNotSupported { us: unsupported_sanitizers.to_string() }); } _ => { sess.dcx().emit_err(errors::SanitizersNotSupported { us: unsupported_sanitizers.to_string(), }); } } // Cannot mix and match mutually-exclusive sanitizers. if let Some((first, second)) = sess.opts.unstable_opts.sanitizer.mutually_exclusive() { sess.dcx().emit_err(errors::CannotMixAndMatchSanitizers { first: first.to_string(), second: second.to_string(), }); } // Cannot enable crt-static with sanitizers on Linux if sess.crt_static(None) && !sess.opts.unstable_opts.sanitizer.is_empty() && !sess.target.is_like_msvc { sess.dcx().emit_err(errors::CannotEnableCrtStaticLinux); } // LLVM CFI requires LTO. if sess.is_sanitizer_cfi_enabled() && !(sess.lto() == config::Lto::Fat || sess.opts.cg.linker_plugin_lto.enabled()) { sess.dcx().emit_err(errors::SanitizerCfiRequiresLto); } // KCFI requires panic=abort if sess.is_sanitizer_kcfi_enabled() && sess.panic_strategy().unwinds() { sess.dcx().emit_err(errors::SanitizerKcfiRequiresPanicAbort); } // LLVM CFI using rustc LTO requires a single codegen unit. if sess.is_sanitizer_cfi_enabled() && sess.lto() == config::Lto::Fat && (sess.codegen_units().as_usize() != 1) { sess.dcx().emit_err(errors::SanitizerCfiRequiresSingleCodegenUnit); } // Canonical jump tables requires CFI. if sess.is_sanitizer_cfi_canonical_jump_tables_disabled() { if !sess.is_sanitizer_cfi_enabled() { sess.dcx().emit_err(errors::SanitizerCfiCanonicalJumpTablesRequiresCfi); } } // KCFI arity indicator requires KCFI. if sess.is_sanitizer_kcfi_arity_enabled() && !sess.is_sanitizer_kcfi_enabled() { sess.dcx().emit_err(errors::SanitizerKcfiArityRequiresKcfi); } // LLVM CFI pointer generalization requires CFI or KCFI. if sess.is_sanitizer_cfi_generalize_pointers_enabled() { if !(sess.is_sanitizer_cfi_enabled() || sess.is_sanitizer_kcfi_enabled()) { sess.dcx().emit_err(errors::SanitizerCfiGeneralizePointersRequiresCfi); } } // LLVM CFI integer normalization requires CFI or KCFI. if sess.is_sanitizer_cfi_normalize_integers_enabled() { if !(sess.is_sanitizer_cfi_enabled() || sess.is_sanitizer_kcfi_enabled()) { sess.dcx().emit_err(errors::SanitizerCfiNormalizeIntegersRequiresCfi); } } // LTO unit splitting requires LTO. if sess.is_split_lto_unit_enabled() && !(sess.lto() == config::Lto::Fat || sess.lto() == config::Lto::Thin || sess.opts.cg.linker_plugin_lto.enabled()) { sess.dcx().emit_err(errors::SplitLtoUnitRequiresLto); } // VFE requires LTO. if sess.lto() != config::Lto::Fat { if sess.opts.unstable_opts.virtual_function_elimination { sess.dcx().emit_err(errors::UnstableVirtualFunctionElimination); } } if sess.opts.unstable_opts.stack_protector != StackProtector::None { if !sess.target.options.supports_stack_protector { sess.dcx().emit_warn(errors::StackProtectorNotSupportedForTarget { stack_protector: sess.opts.unstable_opts.stack_protector, target_triple: &sess.opts.target_triple, }); } } if sess.opts.unstable_opts.small_data_threshold.is_some() { if sess.target.small_data_threshold_support() == SmallDataThresholdSupport::None { sess.dcx().emit_warn(errors::SmallDataThresholdNotSupportedForTarget { target_triple: &sess.opts.target_triple, }) } } if sess.opts.unstable_opts.branch_protection.is_some() && sess.target.arch != Arch::AArch64 { sess.dcx().emit_err(errors::BranchProtectionRequiresAArch64); } if let Some(dwarf_version) = sess.opts.cg.dwarf_version.or(sess.opts.unstable_opts.dwarf_version) { // DWARF 1 is not supported by LLVM and DWARF 6 is not yet finalized. if dwarf_version < 2 || dwarf_version > 5 { sess.dcx().emit_err(errors::UnsupportedDwarfVersion { dwarf_version }); } } if !sess.target.options.supported_split_debuginfo.contains(&sess.split_debuginfo()) && !sess.opts.unstable_opts.unstable_options { sess.dcx() .emit_err(errors::SplitDebugInfoUnstablePlatform { debuginfo: sess.split_debuginfo() }); } if sess.opts.unstable_opts.embed_source { let dwarf_version = sess.dwarf_version(); if dwarf_version < 5 { sess.dcx().emit_warn(errors::EmbedSourceInsufficientDwarfVersion { dwarf_version }); } if sess.opts.debuginfo == DebugInfo::None { sess.dcx().emit_warn(errors::EmbedSourceRequiresDebugInfo); } } if sess.opts.unstable_opts.instrument_xray.is_some() && !sess.target.options.supports_xray { sess.dcx().emit_err(errors::InstrumentationNotSupported { us: "XRay".to_string() }); } if let Some(flavor) = sess.opts.cg.linker_flavor && let Some(compatible_list) = sess.target.linker_flavor.check_compatibility(flavor) { let flavor = flavor.desc(); sess.dcx().emit_err(errors::IncompatibleLinkerFlavor { flavor, compatible_list }); } if sess.opts.unstable_opts.function_return != FunctionReturn::default() { if !matches!(sess.target.arch, Arch::X86 | Arch::X86_64) { sess.dcx().emit_err(errors::FunctionReturnRequiresX86OrX8664); } } if sess.opts.unstable_opts.indirect_branch_cs_prefix { if !matches!(sess.target.arch, Arch::X86 | Arch::X86_64) { sess.dcx().emit_err(errors::IndirectBranchCsPrefixRequiresX86OrX8664); } } if let Some(regparm) = sess.opts.unstable_opts.regparm { if regparm > 3 { sess.dcx().emit_err(errors::UnsupportedRegparm { regparm }); } if sess.target.arch != Arch::X86 { sess.dcx().emit_err(errors::UnsupportedRegparmArch); } } if sess.opts.unstable_opts.reg_struct_return { if sess.target.arch != Arch::X86 { sess.dcx().emit_err(errors::UnsupportedRegStructReturnArch); } } // The code model check applies to `thunk` and `thunk-extern`, but not `thunk-inline`, so it is // kept as a `match` to force a change if new ones are added, even if we currently only support // `thunk-extern` like Clang. match sess.opts.unstable_opts.function_return { FunctionReturn::Keep => (), FunctionReturn::ThunkExtern => { // FIXME: In principle, the inherited base LLVM target code model could be large, // but this only checks whether we were passed one explicitly (like Clang does). if let Some(code_model) = sess.code_model() && code_model == CodeModel::Large { sess.dcx().emit_err(errors::FunctionReturnThunkExternRequiresNonLargeCodeModel); } } } if sess.opts.unstable_opts.packed_stack { if sess.target.arch != Arch::S390x { sess.dcx().emit_err(errors::UnsupportedPackedStack); } } } /// Holds data on the current incremental compilation session, if there is one. #[derive(Debug)] enum IncrCompSession { /// This is the state the session will be in until the incr. comp. dir is /// needed. NotInitialized, /// This is the state during which the session directory is private and can /// be modified. `_lock_file` is never directly used, but its presence /// alone has an effect, because the file will unlock when the session is /// dropped. Active { session_directory: PathBuf, _lock_file: flock::Lock }, /// This is the state after the session directory has been finalized. In this /// state, the contents of the directory must not be modified any more. Finalized { session_directory: PathBuf }, /// This is an error state that is reached when some compilation error has /// occurred. It indicates that the contents of the session directory must /// not be used, since they might be invalid. InvalidBecauseOfErrors { session_directory: PathBuf }, } /// A wrapper around an [`DiagCtxt`] that is used for early error emissions. pub struct EarlyDiagCtxt { dcx: DiagCtxt, } impl EarlyDiagCtxt { pub fn new(output: ErrorOutputType) -> Self { let emitter = mk_emitter(output); Self { dcx: DiagCtxt::new(emitter) } } /// Swap out the underlying dcx once we acquire the user's preference on error emission /// format. If `early_err` was previously called this will panic. pub fn set_error_format(&mut self, output: ErrorOutputType) { assert!(self.dcx.handle().has_errors().is_none()); let emitter = mk_emitter(output); self.dcx = DiagCtxt::new(emitter); } pub fn early_note(&self, msg: impl Into) { self.dcx.handle().note(msg) } pub fn early_help(&self, msg: impl Into) { self.dcx.handle().struct_help(msg).emit() } #[must_use = "raise_fatal must be called on the returned ErrorGuaranteed in order to exit with a non-zero status code"] pub fn early_err(&self, msg: impl Into) -> ErrorGuaranteed { self.dcx.handle().err(msg) } pub fn early_fatal(&self, msg: impl Into) -> ! { self.dcx.handle().fatal(msg) } pub fn early_struct_fatal(&self, msg: impl Into) -> Diag<'_, FatalAbort> { self.dcx.handle().struct_fatal(msg) } pub fn early_warn(&self, msg: impl Into) { self.dcx.handle().warn(msg) } pub fn early_struct_warn(&self, msg: impl Into) -> Diag<'_, ()> { self.dcx.handle().struct_warn(msg) } } fn mk_emitter(output: ErrorOutputType) -> Box { let emitter: Box = match output { config::ErrorOutputType::HumanReadable { kind, color_config } => match kind { HumanReadableErrorType { short, unicode } => Box::new( AnnotateSnippetEmitter::new(stderr_destination(color_config)) .theme(if unicode { OutputTheme::Unicode } else { OutputTheme::Ascii }) .short_message(short), ), }, config::ErrorOutputType::Json { pretty, json_rendered, color_config } => { Box::new(JsonEmitter::new( Box::new(io::BufWriter::new(io::stderr())), Some(Arc::new(SourceMap::new(FilePathMapping::empty()))), pretty, json_rendered, color_config, )) } }; emitter }