Auto merge of #142689 - Urgau:rollup-4ho6835, r=Urgau

Rollup of 6 pull requests

Successful merges:

 - #135656 (Add `-Z hint-mostly-unused` to tell rustc that most of a crate will go unused)
 - #138237 (Get rid of `EscapeDebugInner`.)
 - #141614 (lint direct use of rustc_type_ir )
 - #142123 (Implement initial support for timing sections (`--json=timings`))
 - #142377 (Try unremapping compiler sources)
 - #142674 (remove duplicate crash test)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_errors/src/emitter.rs

@@ -34,6 +34,7 @@ use crate::snippet::{
     Annotation, AnnotationColumn, AnnotationType, Line, MultilineAnnotation, Style, StyledString,
 };
 use crate::styled_buffer::StyledBuffer;
+use crate::timings::TimingRecord;
 use crate::translation::{Translate, to_fluent_args};
 use crate::{
     CodeSuggestion, DiagInner, DiagMessage, ErrCode, FluentBundle, LazyFallbackBundle, Level,
@@ -164,11 +165,16 @@ impl Margin {
     }
 }
 
+pub enum TimingEvent {
+    Start,
+    End,
+}
+
 const ANONYMIZED_LINE_NUM: &str = "LL";
 
 pub type DynEmitter = dyn Emitter + DynSend;
 
-/// Emitter trait for emitting errors.
+/// Emitter trait for emitting errors and other structured information.
 pub trait Emitter: Translate {
     /// Emit a structured diagnostic.
     fn emit_diagnostic(&mut self, diag: DiagInner, registry: &Registry);
@@ -177,6 +183,10 @@ pub trait Emitter: Translate {
     /// Currently only supported for the JSON format.
     fn emit_artifact_notification(&mut self, _path: &Path, _artifact_type: &str) {}
 
+    /// Emit a timestamp with start/end of a timing section.
+    /// Currently only supported for the JSON format.
+    fn emit_timing_section(&mut self, _record: TimingRecord, _event: TimingEvent) {}
+
     /// Emit a report about future breakage.
     /// Currently only supported for the JSON format.
     fn emit_future_breakage_report(&mut self, _diags: Vec<DiagInner>, _registry: &Registry) {}

compiler/rustc_errors/src/json.rs

@@ -28,9 +28,10 @@ use termcolor::{ColorSpec, WriteColor};
 use crate::diagnostic::IsLint;
 use crate::emitter::{
     ColorConfig, Destination, Emitter, HumanEmitter, HumanReadableErrorType, OutputTheme,
-    should_show_source_code,
+    TimingEvent, should_show_source_code,
 };
 use crate::registry::Registry;
+use crate::timings::{TimingRecord, TimingSection};
 use crate::translation::{Translate, to_fluent_args};
 use crate::{
     CodeSuggestion, FluentBundle, LazyFallbackBundle, MultiSpan, SpanLabel, Subdiag, Suggestions,
@@ -104,6 +105,7 @@ impl JsonEmitter {
 enum EmitTyped<'a> {
     Diagnostic(Diagnostic),
     Artifact(ArtifactNotification<'a>),
+    SectionTiming(SectionTimestamp<'a>),
     FutureIncompat(FutureIncompatReport<'a>),
     UnusedExtern(UnusedExterns<'a>),
 }
@@ -135,6 +137,21 @@ impl Emitter for JsonEmitter {
         }
     }
 
+    fn emit_timing_section(&mut self, record: TimingRecord, event: TimingEvent) {
+        let event = match event {
+            TimingEvent::Start => "start",
+            TimingEvent::End => "end",
+        };
+        let name = match record.section {
+            TimingSection::Linking => "link",
+        };
+        let data = SectionTimestamp { name, event, timestamp: record.timestamp };
+        let result = self.emit(EmitTyped::SectionTiming(data));
+        if let Err(e) = result {
+            panic!("failed to print timing section: {e:?}");
+        }
+    }
+
     fn emit_future_breakage_report(&mut self, diags: Vec<crate::DiagInner>, registry: &Registry) {
         let data: Vec<FutureBreakageItem<'_>> = diags
             .into_iter()
@@ -263,6 +280,16 @@ struct ArtifactNotification<'a> {
     emit: &'a str,
 }
 
+#[derive(Serialize)]
+struct SectionTimestamp<'a> {
+    /// Name of the section
+    name: &'a str,
+    /// Start/end of the section
+    event: &'a str,
+    /// Opaque timestamp.
+    timestamp: u128,
+}
+
 #[derive(Serialize)]
 struct FutureBreakageItem<'a> {
     // Always EmitTyped::Diagnostic, but we want to make sure it gets serialized

compiler/rustc_errors/src/lib.rs

@@ -7,6 +7,7 @@
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(not(bootstrap), allow(rustc::direct_use_of_rustc_type_ir))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(array_windows)]
@@ -74,7 +75,9 @@ pub use snippet::Style;
 pub use termcolor::{Color, ColorSpec, WriteColor};
 use tracing::debug;
 
+use crate::emitter::TimingEvent;
 use crate::registry::Registry;
+use crate::timings::TimingRecord;
 
 pub mod annotate_snippet_emitter_writer;
 pub mod codes;
@@ -90,6 +93,7 @@ mod snippet;
 mod styled_buffer;
 #[cfg(test)]
 mod tests;
+pub mod timings;
 pub mod translation;
 
 pub type PResult<'a, T> = Result<T, Diag<'a>>;
@@ -1156,6 +1160,14 @@ impl<'a> DiagCtxtHandle<'a> {
         self.inner.borrow_mut().emitter.emit_artifact_notification(path, artifact_type);
     }
 
+    pub fn emit_timing_section_start(&self, record: TimingRecord) {
+        self.inner.borrow_mut().emitter.emit_timing_section(record, TimingEvent::Start);
+    }
+
+    pub fn emit_timing_section_end(&self, record: TimingRecord) {
+        self.inner.borrow_mut().emitter.emit_timing_section(record, TimingEvent::End);
+    }
+
     pub fn emit_future_breakage_report(&self) {
         let inner = &mut *self.inner.borrow_mut();
         let diags = std::mem::take(&mut inner.future_breakage_diagnostics);

compiler/rustc_errors/src/timings.rs

@@ -0,0 +1,80 @@
+use std::time::Instant;
+
+use crate::DiagCtxtHandle;
+
+/// A high-level section of the compilation process.
+#[derive(Copy, Clone, Debug)]
+pub enum TimingSection {
+    /// Time spent linking.
+    Linking,
+}
+
+/// Section with attached timestamp
+#[derive(Copy, Clone, Debug)]
+pub struct TimingRecord {
+    pub section: TimingSection,
+    /// Microseconds elapsed since some predetermined point in time (~start of the rustc process).
+    pub timestamp: u128,
+}
+
+impl TimingRecord {
+    fn from_origin(origin: Instant, section: TimingSection) -> Self {
+        Self { section, timestamp: Instant::now().duration_since(origin).as_micros() }
+    }
+
+    pub fn section(&self) -> TimingSection {
+        self.section
+    }
+
+    pub fn timestamp(&self) -> u128 {
+        self.timestamp
+    }
+}
+
+/// Manages emission of start/end section timings, enabled through `--json=timings`.
+pub struct TimingSectionHandler {
+    /// Time when the compilation session started.
+    /// If `None`, timing is disabled.
+    origin: Option<Instant>,
+}
+
+impl TimingSectionHandler {
+    pub fn new(enabled: bool) -> Self {
+        let origin = if enabled { Some(Instant::now()) } else { None };
+        Self { origin }
+    }
+
+    /// Returns a RAII guard that will immediately emit a start the provided section, and then emit
+    /// its end when it is dropped.
+    pub fn start_section<'a>(
+        &self,
+        diag_ctxt: DiagCtxtHandle<'a>,
+        section: TimingSection,
+    ) -> TimingSectionGuard<'a> {
+        TimingSectionGuard::create(diag_ctxt, section, self.origin)
+    }
+}
+
+/// RAII wrapper for starting and ending section timings.
+pub struct TimingSectionGuard<'a> {
+    dcx: DiagCtxtHandle<'a>,
+    section: TimingSection,
+    origin: Option<Instant>,
+}
+
+impl<'a> TimingSectionGuard<'a> {
+    fn create(dcx: DiagCtxtHandle<'a>, section: TimingSection, origin: Option<Instant>) -> Self {
+        if let Some(origin) = origin {
+            dcx.emit_timing_section_start(TimingRecord::from_origin(origin, section));
+        }
+        Self { dcx, section, origin }
+    }
+}
+
+impl<'a> Drop for TimingSectionGuard<'a> {
+    fn drop(&mut self) {
+        if let Some(origin) = self.origin {
+            self.dcx.emit_timing_section_end(TimingRecord::from_origin(origin, self.section));
+        }
+    }
+}

compiler/rustc_infer/src/lib.rs

@@ -16,6 +16,7 @@
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(not(bootstrap), allow(rustc::direct_use_of_rustc_type_ir))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]

compiler/rustc_interface/src/queries.rs

@@ -4,6 +4,7 @@ use std::sync::Arc;
 use rustc_codegen_ssa::CodegenResults;
 use rustc_codegen_ssa::traits::CodegenBackend;
 use rustc_data_structures::svh::Svh;
+use rustc_errors::timings::TimingSection;
 use rustc_hir::def_id::LOCAL_CRATE;
 use rustc_metadata::EncodedMetadata;
 use rustc_middle::dep_graph::DepGraph;
@@ -88,6 +89,7 @@ impl Linker {
         }
 
         let _timer = sess.prof.verbose_generic_activity("link_crate");
+        let _timing = sess.timings.start_section(sess.dcx(), TimingSection::Linking);
         codegen_backend.link(sess, codegen_results, self.metadata, &self.output_filenames)
     }
 }

compiler/rustc_interface/src/tests.rs

@@ -802,6 +802,7 @@ fn test_unstable_options_tracking_hash() {
     tracked!(force_unstable_if_unmarked, true);
     tracked!(function_return, FunctionReturn::ThunkExtern);
     tracked!(function_sections, Some(false));
+    tracked!(hint_mostly_unused, true);
     tracked!(human_readable_cgu_names, true);
     tracked!(incremental_ignore_spans, true);
     tracked!(inline_mir, Some(true));

compiler/rustc_lint/messages.ftl

@@ -812,6 +812,9 @@ lint_tykind = usage of `ty::TyKind`
 lint_tykind_kind = usage of `ty::TyKind::<kind>`
     .suggestion = try using `ty::<kind>` directly
 
+lint_type_ir_direct_use = do not use `rustc_type_ir` unless you are implementing type system internals
+    .note = use `rustc_middle::ty` instead
+
 lint_type_ir_inherent_usage = do not use `rustc_type_ir::inherent` unless you're inside of the trait solver
     .note = the method or struct you're looking for is likely defined somewhere else downstream in the compiler
 

compiler/rustc_lint/src/internal.rs

@@ -14,8 +14,8 @@ use {rustc_ast as ast, rustc_hir as hir};
 use crate::lints::{
     BadOptAccessDiag, DefaultHashTypesDiag, DiagOutOfImpl, LintPassByHand,
     NonGlobImportTypeIrInherent, QueryInstability, QueryUntracked, SpanUseEqCtxtDiag,
-    SymbolInternStringLiteralDiag, TyQualified, TykindDiag, TykindKind, TypeIrInherentUsage,
-    TypeIrTraitUsage, UntranslatableDiag,
+    SymbolInternStringLiteralDiag, TyQualified, TykindDiag, TykindKind, TypeIrDirectUse,
+    TypeIrInherentUsage, TypeIrTraitUsage, UntranslatableDiag,
 };
 use crate::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
 
@@ -301,8 +301,18 @@ declare_tool_lint! {
     "usage `rustc_type_ir`-specific abstraction traits outside of trait system",
     report_in_external_macro: true
 }
+declare_tool_lint! {
+    /// The `direct_use_of_rustc_type_ir` lint detects usage of `rustc_type_ir`.
+    ///
+    /// This module should only be used within the trait solver and some desirable
+    /// crates like rustc_middle.
+    pub rustc::DIRECT_USE_OF_RUSTC_TYPE_IR,
+    Allow,
+    "usage `rustc_type_ir` abstraction outside of trait system",
+    report_in_external_macro: true
+}
 
-declare_lint_pass!(TypeIr => [NON_GLOB_IMPORT_OF_TYPE_IR_INHERENT, USAGE_OF_TYPE_IR_INHERENT, USAGE_OF_TYPE_IR_TRAITS]);
+declare_lint_pass!(TypeIr => [DIRECT_USE_OF_RUSTC_TYPE_IR, NON_GLOB_IMPORT_OF_TYPE_IR_INHERENT, USAGE_OF_TYPE_IR_INHERENT, USAGE_OF_TYPE_IR_TRAITS]);
 
 impl<'tcx> LateLintPass<'tcx> for TypeIr {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'tcx>) {
@@ -372,6 +382,21 @@ impl<'tcx> LateLintPass<'tcx> for TypeIr {
             NonGlobImportTypeIrInherent { suggestion: lo.eq_ctxt(hi).then(|| lo.to(hi)), snippet },
         );
     }
+
+    fn check_path(
+        &mut self,
+        cx: &LateContext<'tcx>,
+        path: &rustc_hir::Path<'tcx>,
+        _: rustc_hir::HirId,
+    ) {
+        if let Some(seg) = path.segments.iter().find(|seg| {
+            seg.res
+                .opt_def_id()
+                .is_some_and(|def_id| cx.tcx.is_diagnostic_item(sym::type_ir, def_id))
+        }) {
+            cx.emit_span_lint(DIRECT_USE_OF_RUSTC_TYPE_IR, seg.ident.span, TypeIrDirectUse);
+        }
+    }
 }
 
 declare_tool_lint! {

compiler/rustc_lint/src/lib.rs

@@ -668,6 +668,7 @@ fn register_internals(store: &mut LintStore) {
             LintId::of(USAGE_OF_TYPE_IR_TRAITS),
             LintId::of(BAD_OPT_ACCESS),
             LintId::of(SPAN_USE_EQ_CTXT),
+            LintId::of(DIRECT_USE_OF_RUSTC_TYPE_IR),
         ],
     );
 }

compiler/rustc_lint/src/lints.rs

@@ -969,6 +969,11 @@ pub(crate) struct TypeIrInherentUsage;
 #[note]
 pub(crate) struct TypeIrTraitUsage;
 
+#[derive(LintDiagnostic)]
+#[diag(lint_type_ir_direct_use)]
+#[note]
+pub(crate) struct TypeIrDirectUse;
+
 #[derive(LintDiagnostic)]
 #[diag(lint_non_glob_import_type_ir_inherent)]
 pub(crate) struct NonGlobImportTypeIrInherent {