Auto merge of #119747 - matthiaskrgr:rollup-cm6htwo, r=matthiaskrgr

Rollup of 11 pull requests

Successful merges:

 - #116343 (Stop mentioning internal lang items in no_std binary errors)
 - #118903 (Improved support of collapse_debuginfo attribute for macros.)
 - #119033 (coverage: `llvm-cov` expects column numbers to be bytes, not code points)
 - #119598 (Fix a typo in core::ops::Deref's doc)
 - #119660 (remove an unnecessary stderr-per-bitwidth)
 - #119663 (tests: Normalize `\r\n` to `\n` in some run-make tests)
 - #119681 (coverage: Anonymize line numbers in branch views)
 - #119704 (Fix two variable binding issues in lint let_underscore)
 - #119725 (Add helper for when we want to know if an item has a host param)
 - #119738 (Add `riscv32imafc-esp-espidf` tier 3 target for the ESP32-P4.)
 - #119740 (Remove crossbeam-channel)

Failed merges:

 - #119723 (Remove `-Zdont-buffer-diagnostics`.)

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

Author: bors

Cargo.lock

@@ -3797,7 +3797,6 @@ dependencies = [
 name = "rustc_expand"
 version = "0.0.0"
 dependencies = [
- "crossbeam-channel",
  "rustc_ast",
  "rustc_ast_passes",
  "rustc_ast_pretty",

compiler/rustc_codegen_cranelift/src/debuginfo/line_info.rs

@@ -68,15 +68,7 @@ impl DebugContext {
         // In order to have a good line stepping behavior in debugger, we overwrite debug
         // locations of macro expansions with that of the outermost expansion site (when the macro is
         // annotated with `#[collapse_debuginfo]` or when `-Zdebug-macros` is provided).
-        let span = if tcx.should_collapse_debuginfo(span) {
-            span
-        } else {
-            // Walk up the macro expansion chain until we reach a non-expanded span.
-            // We also stop at the function body level because no line stepping can occur
-            // at the level above that.
-            rustc_span::hygiene::walk_chain(span, function_span.ctxt())
-        };
-
+        let span = tcx.collapsed_debuginfo(span, function_span);
         match tcx.sess.source_map().lookup_line(span.lo()) {
             Ok(SourceFileAndLine { sf: file, line }) => {
                 let line_pos = file.lines()[line];

compiler/rustc_codegen_ssa/src/mir/debuginfo.rs

@@ -228,21 +228,16 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
     /// In order to have a good line stepping behavior in debugger, we overwrite debug
     /// locations of macro expansions with that of the outermost expansion site (when the macro is
     /// annotated with `#[collapse_debuginfo]` or when `-Zdebug-macros` is provided).
-    fn adjust_span_for_debugging(&self, mut span: Span) -> Span {
+    fn adjust_span_for_debugging(&self, span: Span) -> Span {
         // Bail out if debug info emission is not enabled.
         if self.debug_context.is_none() {
             return span;
         }
-
-        if self.cx.tcx().should_collapse_debuginfo(span) {
-            // Walk up the macro expansion chain until we reach a non-expanded span.
-            // We also stop at the function body level because no line stepping can occur
-            // at the level above that.
-            // Use span of the outermost expansion site, while keeping the original lexical scope.
-            span = rustc_span::hygiene::walk_chain(span, self.mir.span.ctxt());
-        }
-
-        span
+        // Walk up the macro expansion chain until we reach a non-expanded span.
+        // We also stop at the function body level because no line stepping can occur
+        // at the level above that.
+        // Use span of the outermost expansion site, while keeping the original lexical scope.
+        self.cx.tcx().collapsed_debuginfo(span, self.mir.span)
     }
 
     fn spill_operand_to_stack(

compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs

@@ -157,9 +157,7 @@ impl Qualif for NeedsNonConstDrop {
         // FIXME(effects): If `destruct` is not a `const_trait`,
         // or effects are disabled in this crate, then give up.
         let destruct_def_id = cx.tcx.require_lang_item(LangItem::Destruct, Some(cx.body.span));
-        if cx.tcx.generics_of(destruct_def_id).host_effect_index.is_none()
-            || !cx.tcx.features().effects
-        {
+        if !cx.tcx.has_host_param(destruct_def_id) || !cx.tcx.features().effects {
             return NeedsDrop::in_any_value_of_ty(cx, ty);
         }
 

compiler/rustc_expand/Cargo.toml

@@ -9,7 +9,6 @@ doctest = false
 
 [dependencies]
 # tidy-alphabetical-start
-crossbeam-channel = "0.5.0"
 rustc_ast = { path = "../rustc_ast" }
 rustc_ast_passes = { path = "../rustc_ast_passes" }
 rustc_ast_pretty = { path = "../rustc_ast_pretty" }

compiler/rustc_expand/src/proc_macro.rs

@@ -13,16 +13,16 @@ use rustc_session::config::ProcMacroExecutionStrategy;
 use rustc_span::profiling::SpannedEventArgRecorder;
 use rustc_span::{Span, DUMMY_SP};
 
-struct CrossbeamMessagePipe<T> {
-    tx: crossbeam_channel::Sender<T>,
-    rx: crossbeam_channel::Receiver<T>,
+struct MessagePipe<T> {
+    tx: std::sync::mpsc::SyncSender<T>,
+    rx: std::sync::mpsc::Receiver<T>,
 }
 
-impl<T> pm::bridge::server::MessagePipe<T> for CrossbeamMessagePipe<T> {
+impl<T> pm::bridge::server::MessagePipe<T> for MessagePipe<T> {
     fn new() -> (Self, Self) {
-        let (tx1, rx1) = crossbeam_channel::bounded(1);
-        let (tx2, rx2) = crossbeam_channel::bounded(1);
-        (CrossbeamMessagePipe { tx: tx1, rx: rx2 }, CrossbeamMessagePipe { tx: tx2, rx: rx1 })
+        let (tx1, rx1) = std::sync::mpsc::sync_channel(1);
+        let (tx2, rx2) = std::sync::mpsc::sync_channel(1);
+        (MessagePipe { tx: tx1, rx: rx2 }, MessagePipe { tx: tx2, rx: rx1 })
     }
 
     fn send(&mut self, value: T) {
@@ -35,7 +35,7 @@ impl<T> pm::bridge::server::MessagePipe<T> for CrossbeamMessagePipe<T> {
 }
 
 fn exec_strategy(ecx: &ExtCtxt<'_>) -> impl pm::bridge::server::ExecutionStrategy {
-    pm::bridge::server::MaybeCrossThread::<CrossbeamMessagePipe<_>>::new(
+    pm::bridge::server::MaybeCrossThread::<MessagePipe<_>>::new(
         ecx.sess.opts.unstable_opts.proc_macro_execution_strategy
             == ProcMacroExecutionStrategy::CrossThread,
     )

compiler/rustc_hir/src/hir.rs

@@ -1997,7 +1997,7 @@ pub enum LocalSource {
     AsyncFn,
     /// A desugared `<expr>.await`.
     AwaitDesugar,
-    /// A desugared `expr = expr`, where the LHS is a tuple, struct or array.
+    /// A desugared `expr = expr`, where the LHS is a tuple, struct, array or underscore expression.
     /// The span is that of the `=` sign.
     AssignDesugar(Span),
 }

compiler/rustc_hir_typeck/src/callee.rs

@@ -490,11 +490,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         self.tcx.require_lang_item(hir::LangItem::FnOnce, Some(span));
                     let fn_once_output_def_id =
                         self.tcx.require_lang_item(hir::LangItem::FnOnceOutput, Some(span));
-                    if self.tcx.generics_of(fn_once_def_id).host_effect_index.is_none() {
-                        if idx == 0 && !self.tcx.is_const_fn_raw(def_id) {
-                            self.dcx().emit_err(errors::ConstSelectMustBeConst { span });
-                        }
-                    } else {
+                    if self.tcx.has_host_param(fn_once_def_id) {
                         let const_param: ty::GenericArg<'tcx> =
                             ([self.tcx.consts.false_, self.tcx.consts.true_])[idx].into();
                         self.register_predicate(traits::Obligation::new(
@@ -523,6 +519,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         ));
 
                         self.select_obligations_where_possible(|_| {});
+                    } else if idx == 0 && !self.tcx.is_const_fn_raw(def_id) {
+                        self.dcx().emit_err(errors::ConstSelectMustBeConst { span });
                     }
                 } else {
                     self.dcx().emit_err(errors::ConstSelectMustBeFn { span, ty: arg_ty });

compiler/rustc_lint/src/let_underscore.rs

@@ -108,6 +108,10 @@ impl<'tcx> LateLintPass<'tcx> for LetUnderscore {
         if !matches!(local.pat.kind, hir::PatKind::Wild) {
             return;
         }
+
+        if matches!(local.source, rustc_hir::LocalSource::AsyncFn) {
+            return;
+        }
         if let Some(init) = local.init {
             let init_ty = cx.typeck_results().expr_ty(init);
             // If the type has a trivial Drop implementation, then it doesn't
@@ -126,6 +130,7 @@ impl<'tcx> LateLintPass<'tcx> for LetUnderscore {
                 suggestion: local.pat.span,
                 multi_suggestion_start: local.span.until(init.span),
                 multi_suggestion_end: init.span.shrink_to_hi(),
+                is_assign_desugar: matches!(local.source, rustc_hir::LocalSource::AssignDesugar(_)),
             };
             if is_sync_lock {
                 let mut span = MultiSpan::from_spans(vec![local.pat.span, init.span]);

compiler/rustc_lint/src/lints.rs

@@ -932,17 +932,19 @@ pub struct NonBindingLetSub {
     pub suggestion: Span,
     pub multi_suggestion_start: Span,
     pub multi_suggestion_end: Span,
+    pub is_assign_desugar: bool,
 }
 
 impl AddToDiagnostic for NonBindingLetSub {
     fn add_to_diagnostic_with<F>(self, diag: &mut Diagnostic, _: F)
     where
         F: Fn(&mut Diagnostic, SubdiagnosticMessage) -> SubdiagnosticMessage,
     {
+        let prefix = if self.is_assign_desugar { "let " } else { "" };
         diag.span_suggestion_verbose(
             self.suggestion,
             fluent::lint_non_binding_let_suggestion,
-            "_unused",
+            format!("{prefix}_unused"),
             Applicability::MachineApplicable,
         );
         diag.multipart_suggestion(