Auto merge of #135277 - matthiaskrgr:rollup-0k61sf8, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - #128110 (Suggest Replacing Comma with Semicolon in Incorrect Repeat Expressions)
 - #134609 (Add new `{x86_64,i686}-win7-windows-gnu` targets)
 - #134875 (Implement `const Destruct` in old solver)
 - #135221 (Include rustc and rustdoc book in replace-version-placeholder)
 - #135231 (bootstrap: Add more comments to some of the test steps)
 - #135256 (Move `mod cargo`  below the import statements)

Failed merges:

 - #135195 (Make `lit_to_mir_constant` and `lit_to_const` infallible)

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

Author: bors

compiler/rustc_hir/src/hir.rs

@@ -7,7 +7,7 @@ use rustc_ast::token::CommentKind;
 use rustc_ast::util::parser::{AssocOp, ExprPrecedence};
 use rustc_ast::{
     self as ast, AttrId, AttrStyle, DelimArgs, FloatTy, InlineAsmOptions, InlineAsmTemplatePiece,
-    IntTy, Label, LitKind, MetaItemInner, MetaItemLit, TraitObjectSyntax, UintTy,
+    IntTy, Label, LitIntType, LitKind, MetaItemInner, MetaItemLit, TraitObjectSyntax, UintTy,
 };
 pub use rustc_ast::{
     BinOp, BinOpKind, BindingMode, BorrowKind, BoundConstness, BoundPolarity, ByRef, CaptureBy,
@@ -2094,6 +2094,18 @@ impl Expr<'_> {
         }
     }
 
+    /// Check if expression is an integer literal that can be used
+    /// where `usize` is expected.
+    pub fn is_size_lit(&self) -> bool {
+        matches!(
+            self.kind,
+            ExprKind::Lit(Lit {
+                node: LitKind::Int(_, LitIntType::Unsuffixed | LitIntType::Unsigned(UintTy::Usize)),
+                ..
+            })
+        )
+    }
+
     /// If `Self.kind` is `ExprKind::DropTemps(expr)`, drill down until we get a non-`DropTemps`
     /// `Expr`. This is used in suggestions to ignore this `ExprKind` as it is semantically
     /// silent, only signaling the ownership system. By doing this, suggestions that check the

compiler/rustc_hir_typeck/messages.ftl

@@ -165,6 +165,8 @@ hir_typeck_remove_semi_for_coerce_ret = the `match` arms can conform to this ret
 hir_typeck_remove_semi_for_coerce_semi = the `match` is a statement because of this semicolon, consider removing it
 hir_typeck_remove_semi_for_coerce_suggestion = remove this semicolon
 
+hir_typeck_replace_comma_with_semicolon = replace the comma with a semicolon to create {$descr}
+
 hir_typeck_return_stmt_outside_of_fn_body =
     {$statement_kind} statement outside of function body
     .encl_body_label = the {$statement_kind} is part of this body...

compiler/rustc_hir_typeck/src/demand.rs

@@ -30,7 +30,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         if expr_ty == expected {
             return;
         }
-
         self.annotate_alternative_method_deref(err, expr, error);
         self.explain_self_literal(err, expr, expected, expr_ty);
 
@@ -39,6 +38,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             || self.suggest_missing_unwrap_expect(err, expr, expected, expr_ty)
             || self.suggest_remove_last_method_call(err, expr, expected)
             || self.suggest_associated_const(err, expr, expected)
+            || self.suggest_semicolon_in_repeat_expr(err, expr, expr_ty)
             || self.suggest_deref_ref_or_into(err, expr, expected, expr_ty, expected_ty_expr)
             || self.suggest_option_to_bool(err, expr, expr_ty, expected)
             || self.suggest_compatible_variants(err, expr, expected, expr_ty)

compiler/rustc_hir_typeck/src/errors.rs

@@ -846,3 +846,16 @@ pub(crate) struct PassFnItemToVariadicFunction {
     pub sugg_span: Span,
     pub replace: String,
 }
+
+#[derive(Subdiagnostic)]
+#[suggestion(
+    hir_typeck_replace_comma_with_semicolon,
+    applicability = "machine-applicable",
+    style = "verbose",
+    code = "; "
+)]
+pub(crate) struct ReplaceCommaWithSemicolon {
+    #[primary_span]
+    pub comma_span: Span,
+    pub descr: &'static str,
+}

compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs

@@ -1320,14 +1320,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 let span = expr.span.shrink_to_hi();
                 let subdiag = if self.type_is_copy_modulo_regions(self.param_env, ty) {
                     errors::OptionResultRefMismatch::Copied { span, def_path }
-                } else if let Some(clone_did) = self.tcx.lang_items().clone_trait()
-                    && rustc_trait_selection::traits::type_known_to_meet_bound_modulo_regions(
-                        self,
-                        self.param_env,
-                        ty,
-                        clone_did,
-                    )
-                {
+                } else if self.type_is_clone_modulo_regions(self.param_env, ty) {
                     errors::OptionResultRefMismatch::Cloned { span, def_path }
                 } else {
                     return false;
@@ -2182,6 +2175,87 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
+    /// Suggest replacing comma with semicolon in incorrect repeat expressions
+    /// like `["_", 10]` or `vec![String::new(), 10]`.
+    pub(crate) fn suggest_semicolon_in_repeat_expr(
+        &self,
+        err: &mut Diag<'_>,
+        expr: &hir::Expr<'_>,
+        expr_ty: Ty<'tcx>,
+    ) -> bool {
+        // Check if `expr` is contained in array of two elements
+        if let hir::Node::Expr(array_expr) = self.tcx.parent_hir_node(expr.hir_id)
+            && let hir::ExprKind::Array(elements) = array_expr.kind
+            && let [first, second] = &elements[..]
+            && second.hir_id == expr.hir_id
+        {
+            // Span between the two elements of the array
+            let comma_span = first.span.between(second.span);
+
+            // Check if `expr` is a constant value of type `usize`.
+            // This can only detect const variable declarations and
+            // calls to const functions.
+
+            // Checking this here instead of rustc_hir::hir because
+            // this check needs access to `self.tcx` but rustc_hir
+            // has no access to `TyCtxt`.
+            let expr_is_const_usize = expr_ty.is_usize()
+                && match expr.kind {
+                    ExprKind::Path(QPath::Resolved(
+                        None,
+                        Path { res: Res::Def(DefKind::Const, _), .. },
+                    )) => true,
+                    ExprKind::Call(
+                        Expr {
+                            kind:
+                                ExprKind::Path(QPath::Resolved(
+                                    None,
+                                    Path { res: Res::Def(DefKind::Fn, fn_def_id), .. },
+                                )),
+                            ..
+                        },
+                        _,
+                    ) => self.tcx.is_const_fn(*fn_def_id),
+                    _ => false,
+                };
+
+            // Type of the first element is guaranteed to be checked
+            // when execution reaches here because `mismatched types`
+            // error occurs only when type of second element of array
+            // is not the same as type of first element.
+            let first_ty = self.typeck_results.borrow().expr_ty(first);
+
+            // `array_expr` is from a macro `vec!["a", 10]` if
+            // 1. array expression's span is imported from a macro
+            // 2. first element of array implements `Clone` trait
+            // 3. second element is an integer literal or is an expression of `usize` like type
+            if self.tcx.sess.source_map().is_imported(array_expr.span)
+                && self.type_is_clone_modulo_regions(self.param_env, first_ty)
+                && (expr.is_size_lit() || expr_ty.is_usize_like())
+            {
+                err.subdiagnostic(errors::ReplaceCommaWithSemicolon {
+                    comma_span,
+                    descr: "a vector",
+                });
+                return true;
+            }
+
+            // `array_expr` is from an array `["a", 10]` if
+            // 1. first element of array implements `Copy` trait
+            // 2. second element is an integer literal or is a const value of type `usize`
+            if self.type_is_copy_modulo_regions(self.param_env, first_ty)
+                && (expr.is_size_lit() || expr_is_const_usize)
+            {
+                err.subdiagnostic(errors::ReplaceCommaWithSemicolon {
+                    comma_span,
+                    descr: "an array",
+                });
+                return true;
+            }
+        }
+        false
+    }
+
     /// If the expected type is an enum (Issue #55250) with any variants whose
     /// sole field is of the found type, suggest such variants. (Issue #42764)
     pub(crate) fn suggest_compatible_variants(

compiler/rustc_middle/src/ty/mod.rs

@@ -1417,8 +1417,8 @@ impl Hash for FieldDef {
 impl<'tcx> FieldDef {
     /// Returns the type of this field. The resulting type is not normalized. The `arg` is
     /// typically obtained via the second field of [`TyKind::Adt`].
-    pub fn ty(&self, tcx: TyCtxt<'tcx>, arg: GenericArgsRef<'tcx>) -> Ty<'tcx> {
-        tcx.type_of(self.did).instantiate(tcx, arg)
+    pub fn ty(&self, tcx: TyCtxt<'tcx>, args: GenericArgsRef<'tcx>) -> Ty<'tcx> {
+        tcx.type_of(self.did).instantiate(tcx, args)
     }
 
     /// Computes the `Ident` of this variant by looking up the `Span`

compiler/rustc_middle/src/ty/sty.rs

@@ -27,7 +27,7 @@ use crate::infer::canonical::Canonical;
 use crate::ty::InferTy::*;
 use crate::ty::{
     self, AdtDef, BoundRegionKind, Discr, GenericArg, GenericArgs, GenericArgsRef, List, ParamEnv,
-    Region, Ty, TyCtxt, TypeFlags, TypeSuperVisitable, TypeVisitable, TypeVisitor,
+    Region, Ty, TyCtxt, TypeFlags, TypeSuperVisitable, TypeVisitable, TypeVisitor, UintTy,
 };
 
 // Re-export and re-parameterize some `I = TyCtxt<'tcx>` types here
@@ -1017,6 +1017,18 @@ impl<'tcx> Ty<'tcx> {
         }
     }
 
+    /// Check if type is an `usize`.
+    #[inline]
+    pub fn is_usize(self) -> bool {
+        matches!(self.kind(), Uint(UintTy::Usize))
+    }
+
+    /// Check if type is an `usize` or an integral type variable.
+    #[inline]
+    pub fn is_usize_like(self) -> bool {
+        matches!(self.kind(), Uint(UintTy::Usize) | Infer(IntVar(_)))
+    }
+
     #[inline]
     pub fn is_never(self) -> bool {
         matches!(self.kind(), Never)

compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs

@@ -712,6 +712,8 @@ pub(in crate::solve) fn extract_fn_def_from_const_callable<I: Interner>(
     }
 }
 
+// NOTE: Keep this in sync with `evaluate_host_effect_for_destruct_goal` in
+// the old solver, for as long as that exists.
 pub(in crate::solve) fn const_conditions_for_destruct<I: Interner>(
     cx: I,
     self_ty: I::Ty,

compiler/rustc_target/src/spec/mod.rs

@@ -1812,9 +1812,11 @@ supported_targets! {
     ("aarch64-unknown-illumos", aarch64_unknown_illumos),
 
     ("x86_64-pc-windows-gnu", x86_64_pc_windows_gnu),
+    ("x86_64-uwp-windows-gnu", x86_64_uwp_windows_gnu),
+    ("x86_64-win7-windows-gnu", x86_64_win7_windows_gnu),
     ("i686-pc-windows-gnu", i686_pc_windows_gnu),
     ("i686-uwp-windows-gnu", i686_uwp_windows_gnu),
-    ("x86_64-uwp-windows-gnu", x86_64_uwp_windows_gnu),
+    ("i686-win7-windows-gnu", i686_win7_windows_gnu),
 
     ("aarch64-pc-windows-gnullvm", aarch64_pc_windows_gnullvm),
     ("i686-pc-windows-gnullvm", i686_pc_windows_gnullvm),

compiler/rustc_target/src/spec/targets/i686_win7_windows_gnu.rs

@@ -0,0 +1,35 @@
+use crate::spec::{Cc, FramePointer, LinkerFlavor, Lld, Target, base};
+
+pub(crate) fn target() -> Target {
+    let mut base = base::windows_gnu::opts();
+    base.vendor = "win7".into();
+    base.cpu = "pentium4".into();
+    base.max_atomic_width = Some(64);
+    base.frame_pointer = FramePointer::Always; // Required for backtraces
+    base.linker = Some("i686-w64-mingw32-gcc".into());
+
+    // Mark all dynamic libraries and executables as compatible with the larger 4GiB address
+    // space available to x86 Windows binaries on x86_64.
+    base.add_pre_link_args(LinkerFlavor::Gnu(Cc::No, Lld::No), &[
+        "-m",
+        "i386pe",
+        "--large-address-aware",
+    ]);
+    base.add_pre_link_args(LinkerFlavor::Gnu(Cc::Yes, Lld::No), &["-Wl,--large-address-aware"]);
+
+    Target {
+        llvm_target: "i686-pc-windows-gnu".into(),
+        metadata: crate::spec::TargetMetadata {
+            description: Some("32-bit MinGW (Windows 7+)".into()),
+            tier: Some(3),
+            host_tools: Some(false),
+            std: Some(true),
+        },
+        pointer_width: 32,
+        data_layout: "e-m:x-p:32:32-p270:32:32-p271:32:32-p272:64:64-\
+            i64:64-i128:128-f80:32-n8:16:32-a:0:32-S32"
+            .into(),
+        arch: "x86".into(),
+        options: base,
+    }
+}