Auto merge of #112102 - Nilstrieb:rollup-ivu1hmc, r=Nilstrieb

Rollup of 7 pull requests

Successful merges:

 - #107916 (fix comment on Allocator trait)
 - #111543 (Uplift `clippy::invalid_utf8_in_unchecked` lint)
 - #111872 (fix: dedup `static_candidates` before report)
 - #111955 (bootstrap: Various Step refactors)
 - #112060 (`EarlyBinder::new` -> `EarlyBinder::bind`)
 - #112064 (Migrate GUI colors test to original CSS color format)
 - #112100 (Don't typecheck recovered method call from suggestion)

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

compiler/rustc_codegen_cranelift/src/common.rs

@@ -361,7 +361,7 @@ impl<'tcx> FunctionCx<'_, '_, 'tcx> {
         self.instance.subst_mir_and_normalize_erasing_regions(
             self.tcx,
             ty::ParamEnv::reveal_all(),
-            ty::EarlyBinder::new(value),
+            ty::EarlyBinder::bind(value),
         )
     }
 

compiler/rustc_codegen_llvm/src/debuginfo/create_scope_map.rs

@@ -93,7 +93,7 @@ fn make_mir_scope<'ll, 'tcx>(
             let callee = cx.tcx.subst_and_normalize_erasing_regions(
                 instance.substs,
                 ty::ParamEnv::reveal_all(),
-                ty::EarlyBinder::new(callee),
+                ty::EarlyBinder::bind(callee),
             );
             let callee_fn_abi = cx.fn_abi_of_instance(callee, ty::List::empty());
             cx.dbg_scope_fn(callee, callee_fn_abi, None)

compiler/rustc_codegen_ssa/src/mir/mod.rs

@@ -111,7 +111,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         self.instance.subst_mir_and_normalize_erasing_regions(
             self.cx.tcx(),
             ty::ParamEnv::reveal_all(),
-            ty::EarlyBinder::new(value),
+            ty::EarlyBinder::bind(value),
         )
     }
 }

compiler/rustc_const_eval/src/interpret/eval_context.rs

@@ -497,7 +497,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             .try_subst_mir_and_normalize_erasing_regions(
                 *self.tcx,
                 self.param_env,
-                ty::EarlyBinder::new(value),
+                ty::EarlyBinder::bind(value),
             )
             .map_err(|_| err_inval!(TooGeneric))
     }

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -1280,7 +1280,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             // params (and trait ref's late bound params). This logic is very similar to
             // `Predicate::subst_supertrait`, and it's no coincidence why.
             let shifted_output = tcx.shift_bound_var_indices(num_bound_vars, output);
-            let subst_output = ty::EarlyBinder::new(shifted_output).subst(tcx, substs);
+            let subst_output = ty::EarlyBinder::bind(shifted_output).subst(tcx, substs);
 
             let bound_vars = tcx.late_bound_vars(binding.hir_id);
             ty::Binder::bind_with_vars(subst_output, bound_vars)

compiler/rustc_hir_analysis/src/check/compare_impl_item.rs

@@ -796,14 +796,14 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
                     })
                 });
                 debug!(%ty);
-                collected_tys.insert(def_id, ty::EarlyBinder::new(ty));
+                collected_tys.insert(def_id, ty::EarlyBinder::bind(ty));
             }
             Err(err) => {
                 let reported = tcx.sess.delay_span_bug(
                     return_span,
                     format!("could not fully resolve: {ty} => {err:?}"),
                 );
-                collected_tys.insert(def_id, ty::EarlyBinder::new(tcx.ty_error(reported)));
+                collected_tys.insert(def_id, ty::EarlyBinder::bind(tcx.ty_error(reported)));
             }
         }
     }

compiler/rustc_hir_analysis/src/check/dropck.rs

@@ -128,7 +128,7 @@ fn ensure_drop_predicates_are_implied_by_item_defn<'tcx>(
     // We don't need to normalize this param-env or anything, since we're only
     // substituting it with free params, so no additional param-env normalization
     // can occur on top of what has been done in the param_env query itself.
-    let param_env = ty::EarlyBinder::new(tcx.param_env(adt_def_id))
+    let param_env = ty::EarlyBinder::bind(tcx.param_env(adt_def_id))
         .subst(tcx, adt_to_impl_substs)
         .with_constness(tcx.constness(drop_impl_def_id));
 

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -1407,7 +1407,7 @@ fn check_where_clauses<'tcx>(wfcx: &WfCheckingCtxt<'_, 'tcx>, span: Span, def_id
             }
             let mut param_count = CountParams::default();
             let has_region = pred.visit_with(&mut param_count).is_break();
-            let substituted_pred = ty::EarlyBinder::new(pred).subst(tcx, substs);
+            let substituted_pred = ty::EarlyBinder::bind(pred).subst(tcx, substs);
             // Don't check non-defaulted params, dependent defaults (including lifetimes)
             // or preds with multiple params.
             if substituted_pred.has_non_region_param() || param_count.params.len() > 1 || has_region

compiler/rustc_hir_analysis/src/collect.rs

@@ -1124,7 +1124,7 @@ fn fn_sig(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<ty::PolyFnSig<
             bug!("unexpected sort of node in fn_sig(): {:?}", x);
         }
     };
-    ty::EarlyBinder::new(output)
+    ty::EarlyBinder::bind(output)
 }
 
 fn infer_return_ty_for_fn_sig<'tcx>(
@@ -1312,7 +1312,7 @@ fn impl_trait_ref(
                 check_impl_constness(tcx, impl_.constness, ast_trait_ref),
             )
         })
-        .map(ty::EarlyBinder::new)
+        .map(ty::EarlyBinder::bind)
 }
 
 fn check_impl_constness(

compiler/rustc_hir_analysis/src/collect/item_bounds.rs

@@ -86,7 +86,7 @@ pub(super) fn explicit_item_bounds(
         Some(ty::ImplTraitInTraitData::Trait { opaque_def_id, .. }) => {
             let item = tcx.hir().get_by_def_id(opaque_def_id.expect_local()).expect_item();
             let opaque_ty = item.expect_opaque_ty();
-            return ty::EarlyBinder::new(opaque_type_bounds(
+            return ty::EarlyBinder::bind(opaque_type_bounds(
                 tcx,
                 opaque_def_id.expect_local(),
                 opaque_ty.bounds,
@@ -124,7 +124,7 @@ pub(super) fn explicit_item_bounds(
         }
         _ => bug!("item_bounds called on {:?}", def_id),
     };
-    ty::EarlyBinder::new(bounds)
+    ty::EarlyBinder::bind(bounds)
 }
 
 pub(super) fn item_bounds(

compiler/rustc_hir_analysis/src/collect/type_of.rs

@@ -323,7 +323,7 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<Ty
                 return map[&assoc_item.trait_item_def_id.unwrap()];
             }
             Err(_) => {
-                return ty::EarlyBinder::new(tcx.ty_error_with_message(
+                return ty::EarlyBinder::bind(tcx.ty_error_with_message(
                     DUMMY_SP,
                     "Could not collect return position impl trait in trait tys",
                 ));
@@ -497,7 +497,7 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<Ty
             bug!("unexpected sort of node in type_of(): {:?}", x);
         }
     };
-    ty::EarlyBinder::new(output)
+    ty::EarlyBinder::bind(output)
 }
 
 fn infer_placeholder_type<'a>(

compiler/rustc_hir_analysis/src/outlives/explicit.rs

@@ -68,7 +68,7 @@ impl<'tcx> ExplicitPredicatesMap<'tcx> {
                 }
             }
 
-            ty::EarlyBinder::new(required_predicates)
+            ty::EarlyBinder::bind(required_predicates)
         })
     }
 }

compiler/rustc_hir_analysis/src/outlives/implicit_infer.rs

@@ -74,7 +74,7 @@ pub(super) fn infer_predicates(
             if item_required_predicates.len() > item_predicates_len {
                 predicates_added = true;
                 global_inferred_outlives
-                    .insert(item_did.to_def_id(), ty::EarlyBinder::new(item_required_predicates));
+                    .insert(item_did.to_def_id(), ty::EarlyBinder::bind(item_required_predicates));
             }
         }
 

compiler/rustc_hir_typeck/src/callee.rs

@@ -420,20 +420,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         .steal_diagnostic(segment.ident.span, StashKey::CallIntoMethod)
                 {
                     // Try suggesting `foo(a)` -> `a.foo()` if possible.
-                    if let Some(ty) =
-                        self.suggest_call_as_method(
-                            &mut diag,
-                            segment,
-                            arg_exprs,
-                            call_expr,
-                            expected
-                        )
-                    {
-                        diag.emit();
-                        return ty;
-                    } else {
-                        diag.emit();
-                    }
+                    self.suggest_call_as_method(
+                        &mut diag,
+                        segment,
+                        arg_exprs,
+                        call_expr,
+                        expected
+                    );
+                    diag.emit();
                 }
 
                 let err = self.report_invalid_callee(call_expr, callee_expr, callee_ty, arg_exprs);
@@ -496,9 +490,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         arg_exprs: &'tcx [hir::Expr<'tcx>],
         call_expr: &'tcx hir::Expr<'tcx>,
         expected: Expectation<'tcx>,
-    ) -> Option<Ty<'tcx>> {
+    ) {
         if let [callee_expr, rest @ ..] = arg_exprs {
-            let callee_ty = self.typeck_results.borrow().expr_ty_adjusted_opt(callee_expr)?;
+            let Some(callee_ty) = self.typeck_results.borrow().expr_ty_adjusted_opt(callee_expr) else {
+                return;
+            };
 
             // First, do a probe with `IsSuggestion(true)` to avoid emitting
             // any strange errors. If it's successful, then we'll do a true
@@ -513,7 +509,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 ProbeScope::AllTraits,
                 expected.only_has_type(self),
             ) else {
-                return None;
+                return;
             };
 
             let pick = self.confirm_method(
@@ -525,7 +521,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 segment,
             );
             if pick.illegal_sized_bound.is_some() {
-                return None;
+                return;
             }
 
             let up_to_rcvr_span = segment.ident.span.until(callee_expr.span);
@@ -567,22 +563,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     sugg,
                     Applicability::MaybeIncorrect,
                 );
-
-                // Let's check the method fully now
-                let return_ty = self.check_method_argument_types(
-                    segment.ident.span,
-                    call_expr,
-                    Ok(pick.callee),
-                    rest,
-                    TupleArgumentsFlag::DontTupleArguments,
-                    expected,
-                );
-
-                return Some(return_ty);
             }
         }
-
-        None
     }
 
     fn report_invalid_callee(

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -473,6 +473,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let mut custom_span_label = false;
 
         let static_candidates = &mut no_match_data.static_candidates;
+
+        // `static_candidates` may have same candidates appended by
+        // inherent and extension, which may result in incorrect
+        // diagnostic.
+        static_candidates.dedup();
+
         if !static_candidates.is_empty() {
             err.note(
                 "found the following associated functions; to be used as methods, \

compiler/rustc_lint/messages.ftl

@@ -304,6 +304,14 @@ lint_improper_ctypes_union_layout_help = consider adding a `#[repr(C)]` or `#[re
 lint_improper_ctypes_union_layout_reason = this union has unspecified layout
 lint_improper_ctypes_union_non_exhaustive = this union is non-exhaustive
 
+# FIXME: we should ordinalize $valid_up_to when we add support for doing so
+lint_invalid_from_utf8_checked = calls to `{$method}` with a invalid literal always return an error
+    .label = the literal was valid UTF-8 up to the {$valid_up_to} bytes
+
+# FIXME: we should ordinalize $valid_up_to when we add support for doing so
+lint_invalid_from_utf8_unchecked = calls to `{$method}` with a invalid literal are undefined behavior
+    .label = the literal was valid UTF-8 up to the {$valid_up_to} bytes
+
 lint_lintpass_by_hand = implementing `LintPass` by hand
     .help = try using `declare_lint_pass!` or `impl_lint_pass!` instead
 

compiler/rustc_lint/src/invalid_from_utf8.rs

@@ -0,0 +1,118 @@
+use std::str::Utf8Error;
+
+use rustc_ast::{BorrowKind, LitKind};
+use rustc_hir::{Expr, ExprKind};
+use rustc_span::source_map::Spanned;
+use rustc_span::sym;
+
+use crate::lints::InvalidFromUtf8Diag;
+use crate::{LateContext, LateLintPass, LintContext};
+
+declare_lint! {
+    /// The `invalid_from_utf8_unchecked` lint checks for calls to
+    /// `std::str::from_utf8_unchecked` and `std::str::from_utf8_unchecked_mut`
+    /// with an invalid UTF-8 literal.
+    ///
+    /// ### Example
+    ///
+    /// ```rust,compile_fail
+    /// # #[allow(unused)]
+    /// unsafe {
+    ///     std::str::from_utf8_unchecked(b"Ru\x82st");
+    /// }
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// Creating such a `str` would result in undefined behavior as per documentation
+    /// for `std::str::from_utf8_unchecked` and `std::str::from_utf8_unchecked_mut`.
+    pub INVALID_FROM_UTF8_UNCHECKED,
+    Deny,
+    "using a non UTF-8 literal in `std::str::from_utf8_unchecked`"
+}
+
+declare_lint! {
+    /// The `invalid_from_utf8` lint checks for calls to
+    /// `std::str::from_utf8` and `std::str::from_utf8_mut`
+    /// with an invalid UTF-8 literal.
+    ///
+    /// ### Example
+    ///
+    /// ```rust
+    /// # #[allow(unused)]
+    /// std::str::from_utf8(b"Ru\x82st");
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// Trying to create such a `str` would always return an error as per documentation
+    /// for `std::str::from_utf8` and `std::str::from_utf8_mut`.
+    pub INVALID_FROM_UTF8,
+    Warn,
+    "using a non UTF-8 literal in `std::str::from_utf8`"
+}
+
+declare_lint_pass!(InvalidFromUtf8 => [INVALID_FROM_UTF8_UNCHECKED, INVALID_FROM_UTF8]);
+
+impl<'tcx> LateLintPass<'tcx> for InvalidFromUtf8 {
+    fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
+        if let ExprKind::Call(path, [arg]) = expr.kind
+            && let ExprKind::Path(ref qpath) = path.kind
+            && let Some(def_id) = cx.qpath_res(qpath, path.hir_id).opt_def_id()
+            && let Some(diag_item) = cx.tcx.get_diagnostic_name(def_id)
+            && [sym::str_from_utf8, sym::str_from_utf8_mut,
+                sym::str_from_utf8_unchecked, sym::str_from_utf8_unchecked_mut].contains(&diag_item)
+        {
+            let lint = |utf8_error: Utf8Error| {
+                let label = arg.span;
+                let method = diag_item.as_str().strip_prefix("str_").unwrap();
+                let method = format!("std::str::{method}");
+                let valid_up_to = utf8_error.valid_up_to();
+                let is_unchecked_variant = diag_item.as_str().contains("unchecked");
+
+                cx.emit_spanned_lint(
+                    if is_unchecked_variant { INVALID_FROM_UTF8_UNCHECKED } else { INVALID_FROM_UTF8 },
+                    expr.span,
+                    if is_unchecked_variant {
+                        InvalidFromUtf8Diag::Unchecked { method,  valid_up_to, label }
+                    } else {
+                        InvalidFromUtf8Diag::Checked { method,  valid_up_to, label }
+                    }
+                )
+            };
+
+            match &arg.kind {
+                ExprKind::Lit(Spanned { node: lit, .. }) => {
+                    if let LitKind::ByteStr(bytes, _) = &lit
+                        && let Err(utf8_error) = std::str::from_utf8(bytes)
+                    {
+                        lint(utf8_error);
+                    }
+                },
+                ExprKind::AddrOf(BorrowKind::Ref, _, Expr { kind: ExprKind::Array(args), .. }) => {
+                    let elements = args.iter().map(|e|{
+                        match &e.kind {
+                            ExprKind::Lit(Spanned { node: lit, .. }) => match lit {
+                                LitKind::Byte(b) => Some(*b),
+                                LitKind::Int(b, _) => Some(*b as u8),
+                                _ => None
+                            }
+                            _ => None
+                        }
+                    }).collect::<Option<Vec<_>>>();
+
+                    if let Some(elements) = elements
+                        && let Err(utf8_error) = std::str::from_utf8(&elements)
+                    {
+                        lint(utf8_error);
+                    }
+                }
+                _ => {}
+            }
+        }
+    }
+}