Auto merge of #127614 - matthiaskrgr:rollup-8geziwi, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - #124599 (Suggest borrowing on fn argument that is `impl AsRef`)
 - #127572 (Don't mark `DEBUG_EVENT` struct as `repr(packed)`)
 - #127588 (core: Limit remaining f16 doctests to x86_64 linux)
 - #127591 (Make sure that labels are defined after the primary span in diagnostics)
 - #127598 (Allows `#[diagnostic::do_not_recommend]` to supress trait impls in suggestions as well)
 - #127599 (Rename `lazy_cell_consume` to `lazy_cell_into_inner`)
 - #127601 (check is_ident before parse_ident)
 - #127605 (Remove extern "wasm" ABI)

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

Author: bors

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -445,31 +445,81 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
                 } else {
                     (None, &[][..], 0)
                 };
+                let mut can_suggest_clone = true;
                 if let Some(def_id) = def_id
                     && let node = self.infcx.tcx.hir_node_by_def_id(def_id)
                     && let Some(fn_sig) = node.fn_sig()
                     && let Some(ident) = node.ident()
                     && let Some(pos) = args.iter().position(|arg| arg.hir_id == expr.hir_id)
                     && let Some(arg) = fn_sig.decl.inputs.get(pos + offset)
                 {
-                    let mut span: MultiSpan = arg.span.into();
-                    span.push_span_label(
-                        arg.span,
-                        "this parameter takes ownership of the value".to_string(),
-                    );
-                    let descr = match node.fn_kind() {
-                        Some(hir::intravisit::FnKind::ItemFn(..)) | None => "function",
-                        Some(hir::intravisit::FnKind::Method(..)) => "method",
-                        Some(hir::intravisit::FnKind::Closure) => "closure",
-                    };
-                    span.push_span_label(ident.span, format!("in this {descr}"));
-                    err.span_note(
-                        span,
-                        format!(
-                            "consider changing this parameter type in {descr} `{ident}` to borrow \
-                             instead if owning the value isn't necessary",
-                        ),
-                    );
+                    let mut is_mut = false;
+                    if let hir::TyKind::Path(hir::QPath::Resolved(None, path)) = arg.kind
+                        && let Res::Def(DefKind::TyParam, param_def_id) = path.res
+                        && self
+                            .infcx
+                            .tcx
+                            .predicates_of(def_id)
+                            .instantiate_identity(self.infcx.tcx)
+                            .predicates
+                            .into_iter()
+                            .any(|pred| {
+                                if let ty::ClauseKind::Trait(predicate) = pred.kind().skip_binder()
+                                    && [
+                                        self.infcx.tcx.get_diagnostic_item(sym::AsRef),
+                                        self.infcx.tcx.get_diagnostic_item(sym::AsMut),
+                                        self.infcx.tcx.get_diagnostic_item(sym::Borrow),
+                                        self.infcx.tcx.get_diagnostic_item(sym::BorrowMut),
+                                    ]
+                                    .contains(&Some(predicate.def_id()))
+                                    && let ty::Param(param) = predicate.self_ty().kind()
+                                    && let generics = self.infcx.tcx.generics_of(def_id)
+                                    && let param = generics.type_param(*param, self.infcx.tcx)
+                                    && param.def_id == param_def_id
+                                {
+                                    if [
+                                        self.infcx.tcx.get_diagnostic_item(sym::AsMut),
+                                        self.infcx.tcx.get_diagnostic_item(sym::BorrowMut),
+                                    ]
+                                    .contains(&Some(predicate.def_id()))
+                                    {
+                                        is_mut = true;
+                                    }
+                                    true
+                                } else {
+                                    false
+                                }
+                            })
+                    {
+                        // The type of the argument corresponding to the expression that got moved
+                        // is a type parameter `T`, which is has a `T: AsRef` obligation.
+                        err.span_suggestion_verbose(
+                            expr.span.shrink_to_lo(),
+                            "borrow the value to avoid moving it",
+                            format!("&{}", if is_mut { "mut " } else { "" }),
+                            Applicability::MachineApplicable,
+                        );
+                        can_suggest_clone = is_mut;
+                    } else {
+                        let mut span: MultiSpan = arg.span.into();
+                        span.push_span_label(
+                            arg.span,
+                            "this parameter takes ownership of the value".to_string(),
+                        );
+                        let descr = match node.fn_kind() {
+                            Some(hir::intravisit::FnKind::ItemFn(..)) | None => "function",
+                            Some(hir::intravisit::FnKind::Method(..)) => "method",
+                            Some(hir::intravisit::FnKind::Closure) => "closure",
+                        };
+                        span.push_span_label(ident.span, format!("in this {descr}"));
+                        err.span_note(
+                            span,
+                            format!(
+                                "consider changing this parameter type in {descr} `{ident}` to \
+                                 borrow instead if owning the value isn't necessary",
+                            ),
+                        );
+                    }
                 }
                 let place = &self.move_data.move_paths[mpi].place;
                 let ty = place.ty(self.body, self.infcx.tcx).ty;
@@ -487,9 +537,10 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
                         ClosureKind::Coroutine(CoroutineKind::Desugared(_, CoroutineSource::Block)),
                     ..
                 } = move_spans
+                    && can_suggest_clone
                 {
                     self.suggest_cloning(err, ty, expr, None, Some(move_spans));
-                } else if self.suggest_hoisting_call_outside_loop(err, expr) {
+                } else if self.suggest_hoisting_call_outside_loop(err, expr) && can_suggest_clone {
                     // The place where the type moves would be misleading to suggest clone.
                     // #121466
                     self.suggest_cloning(err, ty, expr, None, Some(move_spans));

compiler/rustc_codegen_llvm/src/attributes.rs

@@ -6,7 +6,6 @@ use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, PatchableFuncti
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_session::config::{FunctionReturn, OptLevel};
 use rustc_span::symbol::sym;
-use rustc_target::spec::abi::Abi;
 use rustc_target::spec::{FramePointer, SanitizerSet, StackProbeType, StackProtector};
 use smallvec::SmallVec;
 
@@ -482,7 +481,7 @@ pub fn from_fn_attrs<'ll, 'tcx>(
         return;
     }
 
-    let mut function_features = function_features
+    let function_features = function_features
         .iter()
         .flat_map(|feat| {
             llvm_util::to_llvm_features(cx.tcx.sess, feat).into_iter().map(|f| format!("+{f}"))
@@ -504,17 +503,6 @@ pub fn from_fn_attrs<'ll, 'tcx>(
             let name = name.as_str();
             to_add.push(llvm::CreateAttrStringValue(cx.llcx, "wasm-import-name", name));
         }
-
-        // The `"wasm"` abi on wasm targets automatically enables the
-        // `+multivalue` feature because the purpose of the wasm abi is to match
-        // the WebAssembly specification, which has this feature. This won't be
-        // needed when LLVM enables this `multivalue` feature by default.
-        if !cx.tcx.is_closure_like(instance.def_id()) {
-            let abi = cx.tcx.fn_sig(instance.def_id()).skip_binder().abi();
-            if abi == Abi::Wasm {
-                function_features.push("+multivalue".to_string());
-            }
-        }
     }
 
     let global_features = cx.tcx.global_backend_features(()).iter().map(|s| s.as_str());