Auto merge of #154999 - cuviper:beta-next, r=cuviper

[beta] reverts and backports

This reverts two `dbg!` changes to avoid regressions[^1][^2] in the upcoming 1.95 release:

- std: avoid tearing `dbg!` prints #149869
- don't drop arguments' temporaries in `dbg!` #154074
  - ... which was previously backported in #154725

This also reverts a stabilization over a late issue[^3] of semantics:

- Stabilize `assert_matches` #137487

And a few other backport/reverts from `main`:

- Revert performing basic const checks in typeck on stable #154930 / #155033
- Revert "`-Znext-solver` Remove the forced ambiguity hack from search graph" #154712
- Clarify that core::range ranges do not have special syntax #155002
  
[^1]: #153850
[^2]: #154988
[^3]: #154406

Author: bors

compiler/rustc_abi/src/lib.rs

@@ -1,5 +1,5 @@
 // tidy-alphabetical-start
-#![cfg_attr(all(feature = "nightly", bootstrap, test), feature(assert_matches))]
+#![cfg_attr(all(feature = "nightly", test), feature(assert_matches))]
 #![cfg_attr(feature = "nightly", allow(internal_features))]
 #![cfg_attr(feature = "nightly", feature(rustc_attrs))]
 #![cfg_attr(feature = "nightly", feature(step_trait))]

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -545,6 +545,8 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
     }
 
     // for dbg!(x) which may take ownership, suggest dbg!(&x) instead
+    // but here we actually do not check whether the macro name is `dbg!`
+    // so that we may extend the scope a bit larger to cover more cases
     fn suggest_ref_for_dbg_args(
         &self,
         body: &hir::Expr<'_>,
@@ -558,41 +560,29 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
         });
         let Some(var_info) = var_info else { return };
         let arg_name = var_info.name;
-        struct MatchArgFinder<'tcx> {
-            tcx: TyCtxt<'tcx>,
-            move_span: Span,
+        struct MatchArgFinder {
+            expr_span: Span,
+            match_arg_span: Option<Span>,
             arg_name: Symbol,
-            match_arg_span: Option<Span> = None,
         }
-        impl Visitor<'_> for MatchArgFinder<'_> {
+        impl Visitor<'_> for MatchArgFinder {
             fn visit_expr(&mut self, e: &hir::Expr<'_>) {
                 // dbg! is expanded into a match pattern, we need to find the right argument span
-                if let hir::ExprKind::Match(scrutinee, ..) = &e.kind
-                    && let hir::ExprKind::Tup(args) = scrutinee.kind
-                    && e.span.macro_backtrace().any(|expn| {
-                        expn.macro_def_id.is_some_and(|macro_def_id| {
-                            self.tcx.is_diagnostic_item(sym::dbg_macro, macro_def_id)
-                        })
-                    })
+                if let hir::ExprKind::Match(expr, ..) = &e.kind
+                    && let hir::ExprKind::Path(hir::QPath::Resolved(
+                        _,
+                        path @ Path { segments: [seg], .. },
+                    )) = &expr.kind
+                    && seg.ident.name == self.arg_name
+                    && self.expr_span.source_callsite().contains(expr.span)
                 {
-                    for arg in args {
-                        if let hir::ExprKind::Path(hir::QPath::Resolved(
-                            _,
-                            path @ Path { segments: [seg], .. },
-                        )) = &arg.kind
-                            && seg.ident.name == self.arg_name
-                            && self.move_span.source_equal(arg.span)
-                        {
-                            self.match_arg_span = Some(path.span);
-                            return;
-                        }
-                    }
+                    self.match_arg_span = Some(path.span);
                 }
                 hir::intravisit::walk_expr(self, e);
             }
         }
 
-        let mut finder = MatchArgFinder { tcx: self.infcx.tcx, move_span, arg_name, .. };
+        let mut finder = MatchArgFinder { expr_span: move_span, match_arg_span: None, arg_name };
         finder.visit_expr(body);
         if let Some(macro_arg_span) = finder.match_arg_span {
             err.span_suggestion_verbose(

compiler/rustc_borrowck/src/lib.rs

@@ -2,8 +2,8 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(default_field_values)]
 #![feature(file_buffered)]

compiler/rustc_builtin_macros/src/lib.rs

@@ -3,8 +3,8 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(decl_macro)]
 #![feature(iter_order_by)]

compiler/rustc_codegen_llvm/src/lib.rs

@@ -5,8 +5,8 @@
 //! This API is completely unstable and subject to change.
 
 // tidy-alphabetical-start
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
+#![feature(assert_matches)]
 #![feature(extern_types)]
 #![feature(file_buffered)]
 #![feature(impl_trait_in_assoc_type)]

compiler/rustc_codegen_ssa/src/lib.rs

@@ -1,6 +1,6 @@
 // tidy-alphabetical-start
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(file_buffered)]
 #![feature(negative_impls)]

compiler/rustc_const_eval/src/lib.rs

@@ -1,7 +1,7 @@
 // tidy-alphabetical-start
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
 #![feature(array_try_map)]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(decl_macro)]
 #![feature(never_type)]

compiler/rustc_data_structures/src/lib.rs

@@ -10,14 +10,14 @@
 #![allow(internal_features)]
 #![allow(rustc::default_hash_types)]
 #![allow(rustc::potential_query_instability)]
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(cfg_select))]
 #![cfg_attr(bootstrap, feature(cold_path))]
 #![cfg_attr(test, feature(test))]
 #![deny(unsafe_op_in_unsafe_fn)]
 #![feature(allocator_api)]
 #![feature(ascii_char)]
 #![feature(ascii_char_variants)]
+#![feature(assert_matches)]
 #![feature(auto_traits)]
 #![feature(const_default)]
 #![feature(const_trait_impl)]

compiler/rustc_errors/src/lib.rs

@@ -5,7 +5,7 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![allow(rustc::direct_use_of_rustc_type_ir)]
-#![cfg_attr(bootstrap, feature(assert_matches))]
+#![feature(assert_matches)]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
 #![feature(default_field_values)]

compiler/rustc_hir_analysis/src/lib.rs

@@ -56,8 +56,8 @@ This API is completely unstable and subject to change.
 */
 
 // tidy-alphabetical-start
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
+#![feature(assert_matches)]
 #![feature(default_field_values)]
 #![feature(gen_blocks)]
 #![feature(iter_intersperse)]