blob: 9369c1771a35ed10c6c90caa5e5db0e3c7043ed8 [file] [log] [blame]
pub use crate::code_stats::{DataTypeKind, SizeKind, FieldInfo, VariantInfo};
use crate::code_stats::CodeStats;
use crate::cgu_reuse_tracker::CguReuseTracker;
use rustc_data_structures::fingerprint::Fingerprint;
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use crate::lint;
use crate::filesearch;
use crate::config::{self, OutputType, PrintRequest, Sanitizer, SwitchWithOptPath};
use crate::search_paths::{PathKind, SearchPath};
use crate::utils::duration_to_secs_str;
use rustc_errors::ErrorReported;
use rustc_data_structures::base_n;
use rustc_data_structures::sync::{
self, Lrc, Lock, OneThread, Once, AtomicU64, AtomicUsize, Ordering,
Ordering::SeqCst,
};
use rustc_data_structures::impl_stable_hash_via_hash;
use rustc_errors::{DiagnosticBuilder, DiagnosticId, Applicability};
use rustc_errors::emitter::{Emitter, EmitterWriter};
use rustc_errors::emitter::HumanReadableErrorType;
use rustc_errors::annotate_snippet_emitter_writer::{AnnotateSnippetEmitterWriter};
use syntax_pos::edition::Edition;
use rustc_errors::json::JsonEmitter;
use syntax_pos::source_map;
use crate::parse::ParseSess;
use syntax_pos::{MultiSpan, Span};
use rustc_target::spec::{PanicStrategy, RelroLevel, Target, TargetTriple};
use rustc_data_structures::flock;
use rustc_data_structures::jobserver::{self, Client};
use rustc_data_structures::profiling::{SelfProfiler, SelfProfilerRef};
use std;
use std::cell::{self, RefCell};
use std::env;
use std::fmt;
use std::io::Write;
use std::num::NonZeroU32;
use std::path::PathBuf;
use std::time::Duration;
use std::sync::Arc;
pub struct OptimizationFuel {
/// If `-zfuel=crate=n` is specified, initially set to `n`, otherwise `0`.
remaining: u64,
/// We're rejecting all further optimizations.
out_of_fuel: bool,
}
/// Represents the data associated with a compilation
/// session for a single crate.
pub struct Session {
pub target: config::Config,
pub host: Target,
pub opts: config::Options,
pub host_tlib_path: SearchPath,
/// `None` if the host and target are the same.
pub target_tlib_path: Option<SearchPath>,
pub parse_sess: ParseSess,
pub sysroot: PathBuf,
/// The name of the root source file of the crate, in the local file system.
/// `None` means that there is no source file.
pub local_crate_source_file: Option<PathBuf>,
/// The directory the compiler has been executed in plus a flag indicating
/// if the value stored here has been affected by path remapping.
pub working_dir: (PathBuf, bool),
/// Set of `(DiagnosticId, Option<Span>, message)` tuples tracking
/// (sub)diagnostics that have been set once, but should not be set again,
/// in order to avoid redundantly verbose output (Issue #24690, #44953).
pub one_time_diagnostics: Lock<FxHashSet<(DiagnosticMessageId, Option<Span>, String)>>,
pub crate_types: Once<Vec<config::CrateType>>,
/// The `crate_disambiguator` is constructed out of all the `-C metadata`
/// arguments passed to the compiler. Its value together with the crate-name
/// forms a unique global identifier for the crate. It is used to allow
/// multiple crates with the same name to coexist. See the
/// `rustc_codegen_llvm::back::symbol_names` module for more information.
pub crate_disambiguator: Once<CrateDisambiguator>,
features: Once<rustc_feature::Features>,
/// The maximum recursion limit for potentially infinitely recursive
/// operations such as auto-dereference and monomorphization.
pub recursion_limit: Once<usize>,
/// The maximum length of types during monomorphization.
pub type_length_limit: Once<usize>,
/// Map from imported macro spans (which consist of
/// the localized span for the macro body) to the
/// macro name and definition span in the source crate.
pub imported_macro_spans: OneThread<RefCell<FxHashMap<Span, (String, Span)>>>,
incr_comp_session: OneThread<RefCell<IncrCompSession>>,
/// Used for incremental compilation tests. Will only be populated if
/// `-Zquery-dep-graph` is specified.
pub cgu_reuse_tracker: CguReuseTracker,
/// Used by `-Z self-profile`.
pub prof: SelfProfilerRef,
/// Some measurements that are being gathered during compilation.
pub perf_stats: PerfStats,
/// Data about code being compiled, gathered during compilation.
pub code_stats: CodeStats,
/// If `-zfuel=crate=n` is specified, `Some(crate)`.
optimization_fuel_crate: Option<String>,
/// Tracks fuel info if `-zfuel=crate=n` is specified.
optimization_fuel: Lock<OptimizationFuel>,
// The next two are public because the driver needs to read them.
/// If `-zprint-fuel=crate`, `Some(crate)`.
pub print_fuel_crate: Option<String>,
/// Always set to zero and incremented so that we can print fuel expended by a crate.
pub print_fuel: AtomicU64,
/// Loaded up early on in the initialization of this `Session` to avoid
/// false positives about a job server in our environment.
pub jobserver: Client,
/// Cap lint level specified by a driver specifically.
pub driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
/// `Span`s of trait methods that weren't found to avoid emitting object safety errors
pub trait_methods_not_found: Lock<FxHashSet<Span>>,
/// Mapping from ident span to path span for paths that don't exist as written, but that
/// exist under `std`. For example, wrote `str::from_utf8` instead of `std::str::from_utf8`.
pub confused_type_with_std_module: Lock<FxHashMap<Span, Span>>,
}
pub struct PerfStats {
/// The accumulated time spent on computing symbol hashes.
pub symbol_hash_time: Lock<Duration>,
/// The accumulated time spent decoding def path tables from metadata.
pub decode_def_path_tables_time: Lock<Duration>,
/// Total number of values canonicalized queries constructed.
pub queries_canonicalized: AtomicUsize,
/// Number of times this query is invoked.
pub normalize_ty_after_erasing_regions: AtomicUsize,
/// Number of times this query is invoked.
pub normalize_projection_ty: AtomicUsize,
}
/// Enum to support dispatch of one-time diagnostics (in `Session.diag_once`).
enum DiagnosticBuilderMethod {
Note,
SpanNote,
SpanSuggestion(String), // suggestion
// Add more variants as needed to support one-time diagnostics.
}
/// Diagnostic message ID, used by `Session.one_time_diagnostics` to avoid
/// emitting the same message more than once.
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum DiagnosticMessageId {
ErrorId(u16), // EXXXX error code as integer
LintId(lint::LintId),
StabilityId(Option<NonZeroU32>), // issue number
}
impl From<&'static lint::Lint> for DiagnosticMessageId {
fn from(lint: &'static lint::Lint) -> Self {
DiagnosticMessageId::LintId(lint::LintId::of(lint))
}
}
impl Session {
pub fn local_crate_disambiguator(&self) -> CrateDisambiguator {
*self.crate_disambiguator.get()
}
pub fn struct_span_warn<S: Into<MultiSpan>>(
&self,
sp: S,
msg: &str,
) -> DiagnosticBuilder<'_> {
self.diagnostic().struct_span_warn(sp, msg)
}
pub fn struct_span_warn_with_code<S: Into<MultiSpan>>(
&self,
sp: S,
msg: &str,
code: DiagnosticId,
) -> DiagnosticBuilder<'_> {
self.diagnostic().struct_span_warn_with_code(sp, msg, code)
}
pub fn struct_warn(&self, msg: &str) -> DiagnosticBuilder<'_> {
self.diagnostic().struct_warn(msg)
}
pub fn struct_span_err<S: Into<MultiSpan>>(
&self,
sp: S,
msg: &str,
) -> DiagnosticBuilder<'_> {
self.diagnostic().struct_span_err(sp, msg)
}
pub fn struct_span_err_with_code<S: Into<MultiSpan>>(
&self,
sp: S,
msg: &str,
code: DiagnosticId,
) -> DiagnosticBuilder<'_> {
self.diagnostic().struct_span_err_with_code(sp, msg, code)
}
// FIXME: This method should be removed (every error should have an associated error code).
pub fn struct_err(&self, msg: &str) -> DiagnosticBuilder<'_> {
self.diagnostic().struct_err(msg)
}
pub fn struct_err_with_code(
&self,
msg: &str,
code: DiagnosticId,
) -> DiagnosticBuilder<'_> {
self.diagnostic().struct_err_with_code(msg, code)
}
pub fn struct_span_fatal<S: Into<MultiSpan>>(
&self,
sp: S,
msg: &str,
) -> DiagnosticBuilder<'_> {
self.diagnostic().struct_span_fatal(sp, msg)
}
pub fn struct_span_fatal_with_code<S: Into<MultiSpan>>(
&self,
sp: S,
msg: &str,
code: DiagnosticId,
) -> DiagnosticBuilder<'_> {
self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
}
pub fn struct_fatal(&self, msg: &str) -> DiagnosticBuilder<'_> {
self.diagnostic().struct_fatal(msg)
}
pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
self.diagnostic().span_fatal(sp, msg).raise()
}
pub fn span_fatal_with_code<S: Into<MultiSpan>>(
&self,
sp: S,
msg: &str,
code: DiagnosticId,
) -> ! {
self.diagnostic()
.span_fatal_with_code(sp, msg, code)
.raise()
}
pub fn fatal(&self, msg: &str) -> ! {
self.diagnostic().fatal(msg).raise()
}
pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
if is_warning {
self.span_warn(sp, msg);
} else {
self.span_err(sp, msg);
}
}
pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
self.diagnostic().span_err(sp, msg)
}
pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
self.diagnostic().span_err_with_code(sp, &msg, code)
}
pub fn err(&self, msg: &str) {
self.diagnostic().err(msg)
}
pub fn err_count(&self) -> usize {
self.diagnostic().err_count()
}
pub fn has_errors(&self) -> bool {
self.diagnostic().has_errors()
}
pub fn has_errors_or_delayed_span_bugs(&self) -> bool {
self.diagnostic().has_errors_or_delayed_span_bugs()
}
pub fn abort_if_errors(&self) {
self.diagnostic().abort_if_errors();
}
pub fn compile_status(&self) -> Result<(), ErrorReported> {
if self.has_errors() {
self.diagnostic().emit_stashed_diagnostics();
Err(ErrorReported)
} else {
Ok(())
}
}
// FIXME(matthewjasper) Remove this method, it should never be needed.
pub fn track_errors<F, T>(&self, f: F) -> Result<T, ErrorReported>
where
F: FnOnce() -> T,
{
let old_count = self.err_count();
let result = f();
let errors = self.err_count() - old_count;
if errors == 0 {
Ok(result)
} else {
Err(ErrorReported)
}
}
pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
self.diagnostic().span_warn(sp, msg)
}
pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
self.diagnostic().span_warn_with_code(sp, msg, code)
}
pub fn warn(&self, msg: &str) {
self.diagnostic().warn(msg)
}
pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
match opt_sp {
Some(sp) => self.span_warn(sp, msg),
None => self.warn(msg),
}
}
/// Delay a span_bug() call until abort_if_errors()
pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
self.diagnostic().delay_span_bug(sp, msg)
}
pub fn note_without_error(&self, msg: &str) {
self.diagnostic().note_without_error(msg)
}
pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
self.diagnostic().span_note_without_error(sp, msg)
}
pub fn diagnostic(&self) -> &rustc_errors::Handler {
&self.parse_sess.span_diagnostic
}
/// Analogous to calling methods on the given `DiagnosticBuilder`, but
/// deduplicates on lint ID, span (if any), and message for this `Session`
fn diag_once<'a, 'b>(
&'a self,
diag_builder: &'b mut DiagnosticBuilder<'a>,
method: DiagnosticBuilderMethod,
msg_id: DiagnosticMessageId,
message: &str,
span_maybe: Option<Span>,
) {
let id_span_message = (msg_id, span_maybe, message.to_owned());
let fresh = self.one_time_diagnostics
.borrow_mut()
.insert(id_span_message);
if fresh {
match method {
DiagnosticBuilderMethod::Note => {
diag_builder.note(message);
}
DiagnosticBuilderMethod::SpanNote => {
let span = span_maybe.expect("`span_note` needs a span");
diag_builder.span_note(span, message);
}
DiagnosticBuilderMethod::SpanSuggestion(suggestion) => {
let span = span_maybe.expect("`span_suggestion_*` needs a span");
diag_builder.span_suggestion(
span,
message,
suggestion,
Applicability::Unspecified,
);
}
}
}
}
pub fn diag_span_note_once<'a, 'b>(
&'a self,
diag_builder: &'b mut DiagnosticBuilder<'a>,
msg_id: DiagnosticMessageId,
span: Span,
message: &str,
) {
self.diag_once(
diag_builder,
DiagnosticBuilderMethod::SpanNote,
msg_id,
message,
Some(span),
);
}
pub fn diag_note_once<'a, 'b>(
&'a self,
diag_builder: &'b mut DiagnosticBuilder<'a>,
msg_id: DiagnosticMessageId,
message: &str,
) {
self.diag_once(
diag_builder,
DiagnosticBuilderMethod::Note,
msg_id,
message,
None,
);
}
pub fn diag_span_suggestion_once<'a, 'b>(
&'a self,
diag_builder: &'b mut DiagnosticBuilder<'a>,
msg_id: DiagnosticMessageId,
span: Span,
message: &str,
suggestion: String,
) {
self.diag_once(
diag_builder,
DiagnosticBuilderMethod::SpanSuggestion(suggestion),
msg_id,
message,
Some(span),
);
}
pub fn source_map(&self) -> &source_map::SourceMap {
self.parse_sess.source_map()
}
pub fn verbose(&self) -> bool {
self.opts.debugging_opts.verbose
}
pub fn time_passes(&self) -> bool {
self.opts.debugging_opts.time_passes || self.opts.debugging_opts.time
}
pub fn time_extended(&self) -> bool {
self.opts.debugging_opts.time_passes
}
pub fn instrument_mcount(&self) -> bool {
self.opts.debugging_opts.instrument_mcount
}
pub fn time_llvm_passes(&self) -> bool {
self.opts.debugging_opts.time_llvm_passes
}
pub fn meta_stats(&self) -> bool {
self.opts.debugging_opts.meta_stats
}
pub fn asm_comments(&self) -> bool {
self.opts.debugging_opts.asm_comments
}
pub fn verify_llvm_ir(&self) -> bool {
self.opts.debugging_opts.verify_llvm_ir
|| cfg!(always_verify_llvm_ir)
}
pub fn borrowck_stats(&self) -> bool {
self.opts.debugging_opts.borrowck_stats
}
pub fn print_llvm_passes(&self) -> bool {
self.opts.debugging_opts.print_llvm_passes
}
pub fn binary_dep_depinfo(&self) -> bool {
self.opts.debugging_opts.binary_dep_depinfo
}
/// Gets the features enabled for the current compilation session.
/// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents
/// dependency tracking. Use tcx.features() instead.
#[inline]
pub fn features_untracked(&self) -> &rustc_feature::Features {
self.features.get()
}
pub fn init_features(&self, features: rustc_feature::Features) {
self.features.set(features);
}
/// 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.target.options.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 => {
return if self.opts.cli_forced_thinlto_off {
config::Lto::Fat
} else {
config::Lto::Thin
};
}
}
// 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_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.debugging_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() == 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.target.options.panic_strategy)
}
pub fn fewer_names(&self) -> bool {
let more_names = self.opts
.output_types
.contains_key(&OutputType::LlvmAssembly)
|| self.opts.output_types.contains_key(&OutputType::Bitcode);
// Address sanitizer and memory sanitizer use alloca name when reporting an issue.
let more_names = match self.opts.debugging_opts.sanitizer {
Some(Sanitizer::Address) => true,
Some(Sanitizer::Memory) => true,
_ => more_names,
};
self.opts.debugging_opts.fewer_names || !more_names
}
pub fn no_landing_pads(&self) -> bool {
self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
}
pub fn unstable_options(&self) -> bool {
self.opts.debugging_opts.unstable_options
}
pub fn overflow_checks(&self) -> bool {
self.opts
.cg
.overflow_checks
.or(self.opts.debugging_opts.force_overflow_checks)
.unwrap_or(self.opts.debug_assertions)
}
pub fn crt_static(&self) -> bool {
// If the target does not opt in to crt-static support, use its default.
if self.target.target.options.crt_static_respected {
self.crt_static_feature()
} else {
self.target.target.options.crt_static_default
}
}
pub fn crt_static_feature(&self) -> bool {
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");
// If the target we're compiling for requests a static crt by default,
// then see if the `-crt-static` feature was passed to disable that.
// Otherwise if we don't have a static crt by default then see if the
// `+crt-static` feature was passed.
if self.target.target.options.crt_static_default {
!found_negative
} else {
found_positive
}
}
pub fn must_not_eliminate_frame_pointers(&self) -> bool {
// "mcount" function relies on stack pointer.
// See <https://sourceware.org/binutils/docs/gprof/Implementation.html>.
if self.instrument_mcount() {
true
} else if let Some(x) = self.opts.cg.force_frame_pointers {
x
} else {
!self.target.target.options.eliminate_frame_pointer
}
}
/// Returns the symbol name for the registrar function,
/// given the crate `Svh` and the function `DefIndex`.
pub fn generate_plugin_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
format!(
"__rustc_plugin_registrar_{}__",
disambiguator.to_fingerprint().to_hex()
)
}
pub fn generate_proc_macro_decls_symbol(&self, disambiguator: CrateDisambiguator) -> String {
format!(
"__rustc_proc_macro_decls_{}__",
disambiguator.to_fingerprint().to_hex()
)
}
pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
filesearch::FileSearch::new(
&self.sysroot,
self.opts.target_triple.triple(),
&self.opts.search_paths,
// `target_tlib_path == None` means it's the same as `host_tlib_path`.
self.target_tlib_path.as_ref().unwrap_or(&self.host_tlib_path),
kind,
)
}
pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
filesearch::FileSearch::new(
&self.sysroot,
config::host_triple(),
&self.opts.search_paths,
&self.host_tlib_path,
kind,
)
}
pub fn set_incr_session_load_dep_graph(&self, load: bool) {
let mut incr_comp_session = self.incr_comp_session.borrow_mut();
if let IncrCompSession::Active { ref mut load_dep_graph, .. } = *incr_comp_session {
*load_dep_graph = load;
}
}
pub fn incr_session_load_dep_graph(&self) -> bool {
let incr_comp_session = self.incr_comp_session.borrow();
match *incr_comp_session {
IncrCompSession::Active { load_dep_graph, .. } => load_dep_graph,
_ => false,
}
}
pub fn init_incr_comp_session(
&self,
session_dir: PathBuf,
lock_file: flock::Lock,
load_dep_graph: bool,
) {
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,
load_dep_graph,
};
}
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) -> cell::Ref<'_, PathBuf> {
let incr_comp_session = self.incr_comp_session.borrow();
cell::Ref::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<cell::Ref<'_, PathBuf>> {
if self.opts.incremental.is_some() {
Some(self.incr_comp_session_dir())
} else {
None
}
}
pub fn print_perf_stats(&self) {
println!(
"Total time spent computing symbol hashes: {}",
duration_to_secs_str(*self.perf_stats.symbol_hash_time.lock())
);
println!(
"Total time spent decoding DefPath tables: {}",
duration_to_secs_str(*self.perf_stats.decode_def_path_tables_time.lock())
);
println!("Total queries canonicalized: {}",
self.perf_stats.queries_canonicalized.load(Ordering::Relaxed));
println!("normalize_ty_after_erasing_regions: {}",
self.perf_stats.normalize_ty_after_erasing_regions.load(Ordering::Relaxed));
println!("normalize_projection_ty: {}",
self.perf_stats.normalize_projection_ty.load(Ordering::Relaxed));
}
/// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
/// This expends fuel if applicable, and records fuel if applicable.
pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
let mut ret = true;
if let Some(ref c) = self.optimization_fuel_crate {
if c == crate_name {
assert_eq!(self.threads(), 1);
let mut fuel = self.optimization_fuel.lock();
ret = fuel.remaining != 0;
if fuel.remaining == 0 && !fuel.out_of_fuel {
eprintln!("optimization-fuel-exhausted: {}", msg());
fuel.out_of_fuel = true;
} else if fuel.remaining > 0 {
fuel.remaining -= 1;
}
}
}
if let Some(ref c) = self.print_fuel_crate {
if c == crate_name {
assert_eq!(self.threads(), 1);
self.print_fuel.fetch_add(1, SeqCst);
}
}
ret
}
/// Returns the number of query threads that should be used for this
/// compilation
pub fn threads(&self) -> usize {
self.opts.debugging_opts.threads
}
/// Returns the number of codegen units that should be used for this
/// compilation
pub fn codegen_units(&self) -> usize {
if let Some(n) = self.opts.cli_forced_codegen_units {
return n;
}
if let Some(n) = self.target.target.options.default_codegen_units {
return n as usize;
}
// 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.
16
}
pub fn teach(&self, code: &DiagnosticId) -> bool {
self.opts.debugging_opts.teach && self.diagnostic().must_teach(code)
}
pub fn rust_2015(&self) -> bool {
self.opts.edition == Edition::Edition2015
}
/// Are we allowed to use features from the Rust 2018 edition?
pub fn rust_2018(&self) -> bool {
self.opts.edition >= Edition::Edition2018
}
pub fn edition(&self) -> Edition {
self.opts.edition
}
/// Returns `true` if we cannot skip the PLT for shared library calls.
pub fn needs_plt(&self) -> bool {
// Check if the current target usually needs PLT to be enabled.
// The user can use the command line flag to override it.
let needs_plt = self.target.target.options.needs_plt;
let dbg_opts = &self.opts.debugging_opts;
let relro_level = dbg_opts.relro_level
.unwrap_or(self.target.target.options.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 try to skip it where possible.
dbg_opts.plt.unwrap_or(needs_plt || !full_relro)
}
}
pub fn build_session(
sopts: config::Options,
local_crate_source_file: Option<PathBuf>,
registry: rustc_errors::registry::Registry,
) -> Session {
let file_path_mapping = sopts.file_path_mapping();
build_session_with_source_map(
sopts,
local_crate_source_file,
registry,
Lrc::new(source_map::SourceMap::new(file_path_mapping)),
DiagnosticOutput::Default,
Default::default(),
)
}
fn default_emitter(
sopts: &config::Options,
registry: rustc_errors::registry::Registry,
source_map: &Lrc<source_map::SourceMap>,
emitter_dest: Option<Box<dyn Write + Send>>,
) -> Box<dyn Emitter + sync::Send> {
let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
match (sopts.error_format, emitter_dest) {
(config::ErrorOutputType::HumanReadable(kind), dst) => {
let (short, color_config) = kind.unzip();
if let HumanReadableErrorType::AnnotateSnippet(_) = kind {
let emitter = AnnotateSnippetEmitterWriter::new(
Some(source_map.clone()),
short,
external_macro_backtrace,
);
Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
} else {
let emitter = match dst {
None => EmitterWriter::stderr(
color_config,
Some(source_map.clone()),
short,
sopts.debugging_opts.teach,
sopts.debugging_opts.terminal_width,
external_macro_backtrace,
),
Some(dst) => EmitterWriter::new(
dst,
Some(source_map.clone()),
short,
false, // no teach messages when writing to a buffer
false, // no colors when writing to a buffer
None, // no terminal width
external_macro_backtrace,
),
};
Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
}
},
(config::ErrorOutputType::Json { pretty, json_rendered }, None) => Box::new(
JsonEmitter::stderr(
Some(registry),
source_map.clone(),
pretty,
json_rendered,
external_macro_backtrace,
).ui_testing(sopts.debugging_opts.ui_testing),
),
(config::ErrorOutputType::Json { pretty, json_rendered }, Some(dst)) => Box::new(
JsonEmitter::new(
dst,
Some(registry),
source_map.clone(),
pretty,
json_rendered,
external_macro_backtrace,
).ui_testing(sopts.debugging_opts.ui_testing),
),
}
}
pub enum DiagnosticOutput {
Default,
Raw(Box<dyn Write + Send>)
}
pub fn build_session_with_source_map(
sopts: config::Options,
local_crate_source_file: Option<PathBuf>,
registry: rustc_errors::registry::Registry,
source_map: Lrc<source_map::SourceMap>,
diagnostics_output: DiagnosticOutput,
lint_caps: FxHashMap<lint::LintId, lint::Level>,
) -> 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()
.filter(|&&(ref key, _)| *key == "warnings")
.map(|&(_, ref level)| *level == lint::Allow)
.last()
.unwrap_or(false);
let cap_lints_allow = sopts.lint_cap.map_or(false, |cap| cap == lint::Allow);
let can_emit_warnings = !(warnings_allow || cap_lints_allow);
let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
let dont_buffer_diagnostics = sopts.debugging_opts.dont_buffer_diagnostics;
let report_delayed_bugs = sopts.debugging_opts.report_delayed_bugs;
let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
let write_dest = match diagnostics_output {
DiagnosticOutput::Default => None,
DiagnosticOutput::Raw(write) => Some(write),
};
let emitter = default_emitter(&sopts, registry, &source_map, write_dest);
let diagnostic_handler = rustc_errors::Handler::with_emitter_and_flags(
emitter,
rustc_errors::HandlerFlags {
can_emit_warnings,
treat_err_as_bug,
report_delayed_bugs,
dont_buffer_diagnostics,
external_macro_backtrace,
..Default::default()
},
);
build_session_(
sopts,
local_crate_source_file,
diagnostic_handler,
source_map,
lint_caps,
)
}
fn build_session_(
sopts: config::Options,
local_crate_source_file: Option<PathBuf>,
span_diagnostic: rustc_errors::Handler,
source_map: Lrc<source_map::SourceMap>,
driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
) -> Session {
let self_profiler =
if let SwitchWithOptPath::Enabled(ref d) = sopts.debugging_opts.self_profile {
let directory = if let Some(ref directory) = d {
directory
} else {
std::path::Path::new(".")
};
let profiler = SelfProfiler::new(
directory,
sopts.crate_name.as_ref().map(|s| &s[..]),
&sopts.debugging_opts.self_profile_events
);
match profiler {
Ok(profiler) => {
Some(Arc::new(profiler))
},
Err(e) => {
early_warn(sopts.error_format, &format!("failed to create profiler: {}", e));
None
}
}
}
else { None };
let host_triple = TargetTriple::from_triple(config::host_triple());
let host = Target::search(&host_triple).unwrap_or_else(|e|
span_diagnostic
.fatal(&format!("Error loading host specification: {}", e))
.raise()
);
let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
let parse_sess = ParseSess::with_span_handler(
span_diagnostic,
source_map,
);
let sysroot = match &sopts.maybe_sysroot {
Some(sysroot) => sysroot.clone(),
None => filesearch::get_or_default_sysroot(),
};
let host_triple = config::host_triple();
let target_triple = sopts.target_triple.triple();
let host_tlib_path = SearchPath::from_sysroot_and_triple(&sysroot, host_triple);
let target_tlib_path = if host_triple == target_triple {
None
} else {
Some(SearchPath::from_sysroot_and_triple(&sysroot, target_triple))
};
let file_path_mapping = sopts.file_path_mapping();
let local_crate_source_file =
local_crate_source_file.map(|path| file_path_mapping.map_prefix(path).0);
let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
let optimization_fuel = Lock::new(OptimizationFuel {
remaining: sopts.debugging_opts.fuel.as_ref().map(|i| i.1).unwrap_or(0),
out_of_fuel: false,
});
let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
let print_fuel = AtomicU64::new(0);
let working_dir = env::current_dir().unwrap_or_else(|e|
parse_sess.span_diagnostic
.fatal(&format!("Current directory is invalid: {}", e))
.raise()
);
let working_dir = file_path_mapping.map_prefix(working_dir);
let cgu_reuse_tracker = if sopts.debugging_opts.query_dep_graph {
CguReuseTracker::new()
} else {
CguReuseTracker::new_disabled()
};
let sess = Session {
target: target_cfg,
host,
opts: sopts,
host_tlib_path,
target_tlib_path,
parse_sess,
sysroot,
local_crate_source_file,
working_dir,
one_time_diagnostics: Default::default(),
crate_types: Once::new(),
crate_disambiguator: Once::new(),
features: Once::new(),
recursion_limit: Once::new(),
type_length_limit: Once::new(),
imported_macro_spans: OneThread::new(RefCell::new(FxHashMap::default())),
incr_comp_session: OneThread::new(RefCell::new(IncrCompSession::NotInitialized)),
cgu_reuse_tracker,
prof: SelfProfilerRef::new(self_profiler),
perf_stats: PerfStats {
symbol_hash_time: Lock::new(Duration::from_secs(0)),
decode_def_path_tables_time: Lock::new(Duration::from_secs(0)),
queries_canonicalized: AtomicUsize::new(0),
normalize_ty_after_erasing_regions: AtomicUsize::new(0),
normalize_projection_ty: AtomicUsize::new(0),
},
code_stats: Default::default(),
optimization_fuel_crate,
optimization_fuel,
print_fuel_crate,
print_fuel,
jobserver: jobserver::client(),
driver_lint_caps,
trait_methods_not_found: Lock::new(Default::default()),
confused_type_with_std_module: Lock::new(Default::default()),
};
validate_commandline_args_with_session_available(&sess);
sess
}
// If it is useful to have a Session available already for validating a
// commandline argument, you can do so here.
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 the
// MSVC linker 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 MSVC
// 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.target.options.is_like_msvc {
sess.err("Linker plugin based LTO is not supported together with \
`-C prefer-dynamic` when targeting MSVC");
}
// 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.err(&format!("File `{}` passed to `-C profile-use` does not exist.",
path.display()));
}
}
// PGO does not work reliably with panic=unwind on Windows. Let's make it
// an error to combine the two for now. It always runs into an assertions
// if LLVM is built with assertions, but without assertions it sometimes
// does not crash and will probably generate a corrupted binary.
// We should only display this error if we're actually going to run PGO.
// If we're just supposed to print out some data, don't show the error (#61002).
if sess.opts.cg.profile_generate.enabled() &&
sess.target.target.options.is_like_msvc &&
sess.panic_strategy() == PanicStrategy::Unwind &&
sess.opts.prints.iter().all(|&p| p == PrintRequest::NativeStaticLibs) {
sess.err("Profile-guided optimization does not yet work in conjunction \
with `-Cpanic=unwind` on Windows when targeting MSVC. \
See https://github.com/rust-lang/rust/issues/61002 for details.");
}
}
/// Hash value constructed out of all the `-C metadata` arguments passed to the
/// compiler. Together with the crate-name forms a unique global identifier for
/// the crate.
#[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, RustcEncodable, RustcDecodable)]
pub struct CrateDisambiguator(Fingerprint);
impl CrateDisambiguator {
pub fn to_fingerprint(self) -> Fingerprint {
self.0
}
}
impl fmt::Display for CrateDisambiguator {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
let (a, b) = self.0.as_value();
let as_u128 = a as u128 | ((b as u128) << 64);
f.write_str(&base_n::encode(as_u128, base_n::CASE_INSENSITIVE))
}
}
impl From<Fingerprint> for CrateDisambiguator {
fn from(fingerprint: Fingerprint) -> CrateDisambiguator {
CrateDisambiguator(fingerprint)
}
}
impl_stable_hash_via_hash!(CrateDisambiguator);
/// Holds data on the current incremental compilation session, if there is one.
#[derive(Debug)]
pub 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.
Active {
session_directory: PathBuf,
lock_file: flock::Lock,
load_dep_graph: bool,
},
/// 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 },
}
pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
let emitter: Box<dyn Emitter + sync::Send> = match output {
config::ErrorOutputType::HumanReadable(kind) => {
let (short, color_config) = kind.unzip();
Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
}
config::ErrorOutputType::Json { pretty, json_rendered } =>
Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
};
let handler = rustc_errors::Handler::with_emitter(true, None, emitter);
handler.struct_fatal(msg).emit();
rustc_errors::FatalError.raise();
}
pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
let emitter: Box<dyn Emitter + sync::Send> = match output {
config::ErrorOutputType::HumanReadable(kind) => {
let (short, color_config) = kind.unzip();
Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
}
config::ErrorOutputType::Json { pretty, json_rendered } =>
Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
};
let handler = rustc_errors::Handler::with_emitter(true, None, emitter);
handler.struct_warn(msg).emit();
}
pub type CompileResult = Result<(), ErrorReported>;