Rollup of 8 pull requests

compiler/rustc_ast_passes/messages.ftl

@@ -92,9 +92,6 @@ ast_passes_fn_body_extern = incorrect function inside `extern` block
 ast_passes_fn_param_c_var_args_not_last =
     `...` must be the last argument of a C-variadic function
 
-ast_passes_fn_param_c_var_args_only =
-    C-variadic function must be declared with at least one named argument
-
 ast_passes_fn_param_doc_comment =
     documentation comments cannot be applied to function parameters
     .label = doc comments are not allowed here

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -364,7 +364,7 @@ impl<'a> AstValidator<'a> {
 
     fn check_fn_decl(&self, fn_decl: &FnDecl, self_semantic: SelfSemantic) {
         self.check_decl_num_args(fn_decl);
-        self.check_decl_cvaradic_pos(fn_decl);
+        self.check_decl_cvariadic_pos(fn_decl);
         self.check_decl_attrs(fn_decl);
         self.check_decl_self_param(fn_decl, self_semantic);
     }
@@ -379,13 +379,11 @@ impl<'a> AstValidator<'a> {
         }
     }
 
-    fn check_decl_cvaradic_pos(&self, fn_decl: &FnDecl) {
+    /// Emits an error if a function declaration has a variadic parameter in the
+    /// beginning or middle of parameter list.
+    /// Example: `fn foo(..., x: i32)` will emit an error.
+    fn check_decl_cvariadic_pos(&self, fn_decl: &FnDecl) {
         match &*fn_decl.inputs {
-            [Param { ty, span, .. }] => {
-                if let TyKind::CVarArgs = ty.kind {
-                    self.dcx().emit_err(errors::FnParamCVarArgsOnly { span: *span });
-                }
-            }
             [ps @ .., _] => {
                 for Param { ty, span, .. } in ps {
                     if let TyKind::CVarArgs = ty.kind {

compiler/rustc_ast_passes/src/errors.rs

@@ -92,13 +92,6 @@ pub struct FnParamTooMany {
     pub max_num_args: usize,
 }
 
-#[derive(Diagnostic)]
-#[diag(ast_passes_fn_param_c_var_args_only)]
-pub struct FnParamCVarArgsOnly {
-    #[primary_span]
-    pub span: Span,
-}
-
 #[derive(Diagnostic)]
 #[diag(ast_passes_fn_param_c_var_args_not_last)]
 pub struct FnParamCVarArgsNotLast {

compiler/rustc_codegen_ssa/src/codegen_attrs.rs

@@ -327,6 +327,18 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
                     } else {
                         codegen_fn_attrs.linkage = linkage;
                     }
+                    if tcx.is_mutable_static(did.into()) {
+                        let mut diag = tcx.dcx().struct_span_err(
+                            attr.span,
+                            "mutable statics are not allowed with `#[linkage]`",
+                        );
+                        diag.note(
+                            "making the static mutable would allow changing which symbol the \
+                             static references rather than make the target of the symbol \
+                             mutable",
+                        );
+                        diag.emit();
+                    }
                 }
             }
             sym::link_section => {

compiler/rustc_hir_typeck/src/coercion.rs

@@ -1871,11 +1871,8 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
         // If this is due to a block, then maybe we forgot a `return`/`break`.
         if due_to_block
             && let Some(expr) = expression
-            && let Some((parent_fn_decl, parent_id)) = fcx
-                .tcx
-                .hir()
-                .parent_iter(block_or_return_id)
-                .find_map(|(_, node)| Some((node.fn_decl()?, node.associated_body()?.0)))
+            && let Some(parent_fn_decl) =
+                fcx.tcx.hir().fn_decl_by_hir_id(fcx.tcx.local_def_id_to_hir_id(fcx.body_id))
         {
             fcx.suggest_missing_break_or_return_expr(
                 &mut err,
@@ -1884,7 +1881,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
                 expected,
                 found,
                 block_or_return_id,
-                parent_id,
+                fcx.body_id,
             );
         }
 

compiler/rustc_hir_typeck/src/method/probe.rs

@@ -395,8 +395,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // ambiguous.
         if let Some(bad_ty) = &steps.opt_bad_ty {
             if is_suggestion.0 {
-                // Ambiguity was encountered during a suggestion. Just keep going.
-                debug!("ProbeContext: encountered ambiguity in suggestion");
+                // Ambiguity was encountered during a suggestion. There's really
+                // not much use in suggesting methods in this case.
+                return Err(MethodError::NoMatch(NoMatchData {
+                    static_candidates: Vec::new(),
+                    unsatisfied_predicates: Vec::new(),
+                    out_of_scope_traits: Vec::new(),
+                    similar_candidate: None,
+                    mode,
+                }));
             } else if bad_ty.reached_raw_pointer
                 && !self.tcx.features().arbitrary_self_types
                 && !self.tcx.sess.at_least_rust_2018()

compiler/rustc_mir_transform/src/dataflow_const_prop.rs

@@ -142,10 +142,10 @@ impl<'tcx> ValueAnalysis<'tcx> for ConstAnalysis<'_, 'tcx> {
                     _ => return,
                 };
                 if let Some(variant_target_idx) = variant_target {
-                    for (field_index, operand) in operands.iter().enumerate() {
+                    for (field_index, operand) in operands.iter_enumerated() {
                         if let Some(field) = self.map().apply(
                             variant_target_idx,
-                            TrackElem::Field(FieldIdx::from_usize(field_index)),
+                            TrackElem::Field(field_index),
                         ) {
                             self.assign_operand(state, field, operand);
                         }

compiler/rustc_mir_transform/src/instsimplify.rs

@@ -9,7 +9,6 @@ use rustc_middle::ty::layout::ValidityRequirement;
 use rustc_middle::ty::{self, GenericArgsRef, ParamEnv, Ty, TyCtxt};
 use rustc_span::sym;
 use rustc_span::symbol::Symbol;
-use rustc_target::abi::FieldIdx;
 use rustc_target::spec::abi::Abi;
 
 pub struct InstSimplify;
@@ -217,11 +216,11 @@ impl<'tcx> InstSimplifyContext<'tcx, '_> {
                     && let Some(place) = operand.place()
                 {
                     let variant = adt_def.non_enum_variant();
-                    for (i, field) in variant.fields.iter().enumerate() {
+                    for (i, field) in variant.fields.iter_enumerated() {
                         let field_ty = field.ty(self.tcx, args);
                         if field_ty == *cast_ty {
                             let place = place.project_deeper(
-                                &[ProjectionElem::Field(FieldIdx::from_usize(i), *cast_ty)],
+                                &[ProjectionElem::Field(i, *cast_ty)],
                                 self.tcx,
                             );
                             let operand = if operand.is_move() {

library/core/src/num/int_macros.rs

@@ -1282,8 +1282,7 @@ macro_rules! int_impl {
                 concat!(stringify!($SelfT), "::unchecked_shl cannot overflow"),
                 (
                     rhs: u32 = rhs,
-                    bits: u32 = Self::BITS,
-                ) => rhs < bits,
+                ) => rhs < <$ActualT>::BITS,
             );
 
             // SAFETY: this is guaranteed to be safe by the caller.
@@ -1381,8 +1380,7 @@ macro_rules! int_impl {
                 concat!(stringify!($SelfT), "::unchecked_shr cannot overflow"),
                 (
                     rhs: u32 = rhs,
-                    bits: u32 = Self::BITS,
-                ) => rhs < bits,
+                ) => rhs < <$ActualT>::BITS,
             );
 
             // SAFETY: this is guaranteed to be safe by the caller.

library/core/src/num/uint_macros.rs

@@ -1369,8 +1369,7 @@ macro_rules! uint_impl {
                 concat!(stringify!($SelfT), "::unchecked_shl cannot overflow"),
                 (
                     rhs: u32 = rhs,
-                    bits: u32 = Self::BITS,
-                ) => rhs < bits,
+                ) => rhs < <$ActualT>::BITS,
             );
 
             // SAFETY: this is guaranteed to be safe by the caller.
@@ -1468,8 +1467,7 @@ macro_rules! uint_impl {
                 concat!(stringify!($SelfT), "::unchecked_shr cannot overflow"),
                 (
                     rhs: u32 = rhs,
-                    bits: u32 = Self::BITS,
-                ) => rhs < bits,
+                ) => rhs < <$ActualT>::BITS,
             );
 
             // SAFETY: this is guaranteed to be safe by the caller.

tests/mir-opt/inline/unchecked_shifts.unchecked_shl_unsigned_smaller.Inline.panic-abort.diff

@@ -29,7 +29,7 @@
       }
 
       bb1: {
-+         _6 = core::num::<impl u16>::unchecked_shl::precondition_check(_4, const core::num::<impl u16>::BITS) -> [return: bb2, unwind unreachable];
++         _6 = core::num::<impl u16>::unchecked_shl::precondition_check(_4) -> [return: bb2, unwind unreachable];
 +     }
 + 
 +     bb2: {

tests/mir-opt/inline/unchecked_shifts.unchecked_shl_unsigned_smaller.Inline.panic-unwind.diff

@@ -29,7 +29,7 @@
       }
 
       bb1: {
-+         _6 = core::num::<impl u16>::unchecked_shl::precondition_check(_4, const core::num::<impl u16>::BITS) -> [return: bb2, unwind unreachable];
++         _6 = core::num::<impl u16>::unchecked_shl::precondition_check(_4) -> [return: bb2, unwind unreachable];
 +     }
 + 
 +     bb2: {

tests/mir-opt/inline/unchecked_shifts.unchecked_shr_signed_bigger.Inline.panic-abort.diff

@@ -29,7 +29,7 @@
       }
 
       bb1: {
-+         _6 = core::num::<impl i64>::unchecked_shr::precondition_check(_4, const core::num::<impl i64>::BITS) -> [return: bb2, unwind unreachable];
++         _6 = core::num::<impl i64>::unchecked_shr::precondition_check(_4) -> [return: bb2, unwind unreachable];
 +     }
 + 
 +     bb2: {

tests/mir-opt/inline/unchecked_shifts.unchecked_shr_signed_bigger.Inline.panic-unwind.diff

@@ -29,7 +29,7 @@
       }
 
       bb1: {
-+         _6 = core::num::<impl i64>::unchecked_shr::precondition_check(_4, const core::num::<impl i64>::BITS) -> [return: bb2, unwind unreachable];
++         _6 = core::num::<impl i64>::unchecked_shr::precondition_check(_4) -> [return: bb2, unwind unreachable];
 +     }
 + 
 +     bb2: {

tests/ui/c-variadic/variadic-ffi-no-fixed-args.rs

@@ -1,6 +1,9 @@
+//@ build-pass
+
+// Supported since C23
+// https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2975.pdf
 extern "C" {
     fn foo(...);
-//~^ ERROR C-variadic function must be declared with at least one named argument
 }
 
 fn main() {}

tests/ui/issues/issue-33992.rs

@@ -5,9 +5,6 @@
 
 #![feature(linkage)]
 
-#[linkage = "common"]
-pub static mut TEST1: u32 = 0u32;
-
 #[linkage = "external"]
 pub static TEST2: bool = true;
 

tests/ui/linkage-attr/linkage-attr-mutable-static.rs

@@ -0,0 +1,15 @@
+//! The symbols are resolved by the linker. It doesn't make sense to change
+//! them at runtime, so deny mutable statics with #[linkage].
+
+#![feature(linkage)]
+
+fn main() {
+    extern "C" {
+        #[linkage = "weak"] //~ ERROR mutable statics are not allowed with `#[linkage]`
+        static mut ABC: *const u8;
+    }
+
+    unsafe {
+        assert_eq!(ABC as usize, 0);
+    }
+}

tests/ui/linkage-attr/linkage-attr-mutable-static.stderr

@@ -0,0 +1,10 @@
+error: mutable statics are not allowed with `#[linkage]`
+  --> $DIR/linkage-attr-mutable-static.rs:8:9
+   |
+LL |         #[linkage = "weak"]
+   |         ^^^^^^^^^^^^^^^^^^^
+   |
+   = note: making the static mutable would allow changing which symbol the static references rather than make the target of the symbol mutable
+
+error: aborting due to 1 previous error
+

tests/ui/methods/suggest-method-on-call-for-ambig-receiver.rs

@@ -0,0 +1,16 @@
+// Fix for <https://github.com/rust-lang/rust/issues/125432>.
+
+fn separate_arms() {
+    let mut x = None;
+    match x {
+        None => {
+            x = Some(0);
+        }
+        Some(right) => {
+            consume(right);
+            //~^ ERROR cannot find function `consume` in this scope
+        }
+    }
+}
+
+fn main() {}

tests/ui/methods/suggest-method-on-call-for-ambig-receiver.stderr

@@ -0,0 +1,9 @@
+error[E0425]: cannot find function `consume` in this scope
+  --> $DIR/suggest-method-on-call-for-ambig-receiver.rs:10:13
+   |
+LL |             consume(right);
+   |             ^^^^^^^ not found in this scope
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0425`.

tests/ui/parser/variadic-ffi-semantic-restrictions.rs

@@ -8,14 +8,12 @@ fn f1_1(x: isize, ...) {}
 
 fn f1_2(...) {}
 //~^ ERROR only foreign or `unsafe extern "C"` functions may be C-variadic
-//~| ERROR C-variadic function must be declared with at least one named argument
 
 extern "C" fn f2_1(x: isize, ...) {}
 //~^ ERROR only foreign or `unsafe extern "C"` functions may be C-variadic
 
 extern "C" fn f2_2(...) {}
 //~^ ERROR only foreign or `unsafe extern "C"` functions may be C-variadic
-//~| ERROR C-variadic function must be declared with at least one named argument
 
 extern "C" fn f2_3(..., x: isize) {}
 //~^ ERROR only foreign or `unsafe extern "C"` functions may be C-variadic
@@ -26,7 +24,6 @@ extern "C" fn f3_1(x: isize, ...) {}
 
 extern "C" fn f3_2(...) {}
 //~^ ERROR only foreign or `unsafe extern "C"` functions may be C-variadic
-//~| ERROR C-variadic function must be declared with at least one named argument
 
 extern "C" fn f3_3(..., x: isize) {}
 //~^ ERROR only foreign or `unsafe extern "C"` functions may be C-variadic
@@ -47,8 +44,6 @@ const extern "C" fn f4_3(..., x: isize, ...) {}
 //~| ERROR `...` must be the last argument of a C-variadic function
 
 extern "C" {
-    fn e_f1(...);
-    //~^ ERROR C-variadic function must be declared with at least one named argument
     fn e_f2(..., x: isize);
     //~^ ERROR `...` must be the last argument of a C-variadic function
 }
@@ -60,7 +55,6 @@ impl X {
     //~^ ERROR only foreign or `unsafe extern "C"` functions may be C-variadic
     fn i_f2(...) {}
     //~^ ERROR only foreign or `unsafe extern "C"` functions may be C-variadic
-    //~| ERROR C-variadic function must be declared with at least one named argument
     fn i_f3(..., x: isize, ...) {}
     //~^ ERROR only foreign or `unsafe extern "C"` functions may be C-variadic
     //~| ERROR `...` must be the last argument of a C-variadic function
@@ -80,10 +74,8 @@ trait T {
     //~^ ERROR only foreign or `unsafe extern "C"` functions may be C-variadic
     fn t_f3(...) {}
     //~^ ERROR only foreign or `unsafe extern "C"` functions may be C-variadic
-    //~| ERROR C-variadic function must be declared with at least one named argument
     fn t_f4(...);
     //~^ ERROR only foreign or `unsafe extern "C"` functions may be C-variadic
-    //~| ERROR C-variadic function must be declared with at least one named argument
     fn t_f5(..., x: isize) {}
     //~^ ERROR only foreign or `unsafe extern "C"` functions may be C-variadic
     //~| ERROR `...` must be the last argument of a C-variadic function