Auto merge of #152239 - JonathanBrouwer:rollup-2BolGX5, r=JonathanBrouwer

Rollup of 3 pull requests

Successful merges:

 - #152129 (MGCA: require #[type_const] on free consts too)
 - #152139 (mGCA: Support directly represented negated literals)
 - #152189 (Convert to inline diagnostics in `rustc_passes`)

Author: bors

Cargo.lock

@@ -3789,7 +3789,6 @@ dependencies = [
  "rustc_mir_build",
  "rustc_mir_transform",
  "rustc_parse",
- "rustc_passes",
  "rustc_public",
  "rustc_resolve",
  "rustc_session",
@@ -4417,7 +4416,6 @@ dependencies = [
  "rustc_errors",
  "rustc_expand",
  "rustc_feature",
- "rustc_fluent_macro",
  "rustc_hir",
  "rustc_index",
  "rustc_macros",

compiler/rustc_ast_lowering/src/lib.rs

@@ -2570,7 +2570,19 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
 
                 ConstArg {
                     hir_id: self.lower_node_id(expr.id),
-                    kind: hir::ConstArgKind::Literal(literal.node),
+                    kind: hir::ConstArgKind::Literal { lit: literal.node, negated: false },
+                    span,
+                }
+            }
+            ExprKind::Unary(UnOp::Neg, inner_expr)
+                if let ExprKind::Lit(literal) = &inner_expr.kind =>
+            {
+                let span = expr.span;
+                let literal = self.lower_lit(literal, span);
+
+                ConstArg {
+                    hir_id: self.lower_node_id(expr.id),
+                    kind: hir::ConstArgKind::Literal { lit: literal.node, negated: true },
                     span,
                 }
             }

compiler/rustc_driver_impl/Cargo.toml

@@ -29,7 +29,6 @@ rustc_middle = { path = "../rustc_middle" }
 rustc_mir_build = { path = "../rustc_mir_build" }
 rustc_mir_transform = { path = "../rustc_mir_transform" }
 rustc_parse = { path = "../rustc_parse" }
-rustc_passes = { path = "../rustc_passes" }
 rustc_public = { path = "../rustc_public", features = ["rustc_internal"] }
 rustc_resolve = { path = "../rustc_resolve" }
 rustc_session = { path = "../rustc_session" }

compiler/rustc_driver_impl/src/lib.rs

@@ -117,7 +117,6 @@ pub static DEFAULT_LOCALE_RESOURCES: &[&str] = &[
     rustc_lint::DEFAULT_LOCALE_RESOURCE,
     rustc_mir_build::DEFAULT_LOCALE_RESOURCE,
     rustc_parse::DEFAULT_LOCALE_RESOURCE,
-    rustc_passes::DEFAULT_LOCALE_RESOURCE,
     // tidy-alphabetical-end
 ];
 

compiler/rustc_hir/src/hir.rs

@@ -521,7 +521,10 @@ pub enum ConstArgKind<'hir, Unambig = ()> {
     /// This variant is not always used to represent inference consts, sometimes
     /// [`GenericArg::Infer`] is used instead.
     Infer(Unambig),
-    Literal(LitKind),
+    Literal {
+        lit: LitKind,
+        negated: bool,
+    },
 }
 
 #[derive(Clone, Copy, Debug, HashStable_Generic)]
@@ -1958,8 +1961,6 @@ pub struct PatExpr<'hir> {
 pub enum PatExprKind<'hir> {
     Lit {
         lit: Lit,
-        // FIXME: move this into `Lit` and handle negated literal expressions
-        // once instead of matching on unop neg expressions everywhere.
         negated: bool,
     },
     /// A path pattern for a unit struct/variant or a (maybe-associated) constant.

compiler/rustc_hir/src/intravisit.rs

@@ -1110,7 +1110,7 @@ pub fn walk_const_arg<'v, V: Visitor<'v>>(
         ConstArgKind::Path(qpath) => visitor.visit_qpath(qpath, *hir_id, qpath.span()),
         ConstArgKind::Anon(anon) => visitor.visit_anon_const(*anon),
         ConstArgKind::Error(_) => V::Result::output(), // errors and spans are not important
-        ConstArgKind::Literal(..) => V::Result::output(), // FIXME(mcga)
+        ConstArgKind::Literal { .. } => V::Result::output(), // FIXME(mcga)
     }
 }
 

compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs

@@ -1422,14 +1422,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             LowerTypeRelativePathMode::Const,
         )? {
             TypeRelativePath::AssocItem(def_id, args) => {
-                if !self.tcx().is_type_const(def_id) {
-                    let mut err = self.dcx().struct_span_err(
-                        span,
-                        "use of trait associated const without `#[type_const]`",
-                    );
-                    err.note("the declaration in the trait must be marked with `#[type_const]`");
-                    return Err(err.emit());
-                }
+                self.require_type_const_attribute(def_id, span)?;
                 let ct = Const::new_unevaluated(tcx, ty::UnevaluatedConst::new(def_id, args));
                 let ct = self.check_param_uses_if_mcg(ct, span, false);
                 Ok(ct)
@@ -1885,30 +1878,18 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         item_def_id: DefId,
         trait_segment: Option<&hir::PathSegment<'tcx>>,
         item_segment: &hir::PathSegment<'tcx>,
-    ) -> Const<'tcx> {
-        match self.lower_resolved_assoc_item_path(
+    ) -> Result<Const<'tcx>, ErrorGuaranteed> {
+        let (item_def_id, item_args) = self.lower_resolved_assoc_item_path(
             span,
             opt_self_ty,
             item_def_id,
             trait_segment,
             item_segment,
             ty::AssocTag::Const,
-        ) {
-            Ok((item_def_id, item_args)) => {
-                if !self.tcx().is_type_const(item_def_id) {
-                    let mut err = self.dcx().struct_span_err(
-                        span,
-                        "use of `const` in the type system without `#[type_const]`",
-                    );
-                    err.note("the declaration must be marked with `#[type_const]`");
-                    return Const::new_error(self.tcx(), err.emit());
-                }
-
-                let uv = ty::UnevaluatedConst::new(item_def_id, item_args);
-                Const::new_unevaluated(self.tcx(), uv)
-            }
-            Err(guar) => Const::new_error(self.tcx(), guar),
-        }
+        )?;
+        self.require_type_const_attribute(item_def_id, span)?;
+        let uv = ty::UnevaluatedConst::new(item_def_id, item_args);
+        Ok(Const::new_unevaluated(self.tcx(), uv))
     }
 
     /// Lower a [resolved][hir::QPath::Resolved] (type-level) associated item path.
@@ -2396,8 +2377,8 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             hir::ConstArgKind::Anon(anon) => self.lower_const_arg_anon(anon),
             hir::ConstArgKind::Infer(()) => self.ct_infer(None, const_arg.span),
             hir::ConstArgKind::Error(e) => ty::Const::new_error(tcx, e),
-            hir::ConstArgKind::Literal(kind) => {
-                self.lower_const_arg_literal(&kind, ty, const_arg.span)
+            hir::ConstArgKind::Literal { lit, negated } => {
+                self.lower_const_arg_literal(&lit, negated, ty, const_arg.span)
             }
         }
     }
@@ -2668,6 +2649,10 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                 self.lower_const_param(def_id, hir_id)
             }
             Res::Def(DefKind::Const, did) => {
+                if let Err(guar) = self.require_type_const_attribute(did, span) {
+                    return Const::new_error(self.tcx(), guar);
+                }
+
                 assert_eq!(opt_self_ty, None);
                 let [leading_segments @ .., segment] = path.segments else { bug!() };
                 let _ = self
@@ -2718,6 +2703,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                     trait_segment,
                     path.segments.last().unwrap(),
                 )
+                .unwrap_or_else(|guar| Const::new_error(tcx, guar))
             }
             Res::Def(DefKind::Static { .. }, _) => {
                 span_bug!(span, "use of bare `static` ConstArgKind::Path's not yet supported")
@@ -2804,9 +2790,15 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
     }
 
     #[instrument(skip(self), level = "debug")]
-    fn lower_const_arg_literal(&self, kind: &LitKind, ty: Ty<'tcx>, span: Span) -> Const<'tcx> {
+    fn lower_const_arg_literal(
+        &self,
+        kind: &LitKind,
+        neg: bool,
+        ty: Ty<'tcx>,
+        span: Span,
+    ) -> Const<'tcx> {
         let tcx = self.tcx();
-        let input = LitToConstInput { lit: *kind, ty, neg: false };
+        let input = LitToConstInput { lit: *kind, ty, neg };
         tcx.at(span).lit_to_const(input)
     }
 
@@ -2843,6 +2835,33 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             .map(|l| tcx.at(expr.span).lit_to_const(l))
     }
 
+    fn require_type_const_attribute(
+        &self,
+        def_id: DefId,
+        span: Span,
+    ) -> Result<(), ErrorGuaranteed> {
+        let tcx = self.tcx();
+        if tcx.is_type_const(def_id) {
+            Ok(())
+        } else {
+            let mut err = self
+                .dcx()
+                .struct_span_err(span, "use of `const` in the type system without `#[type_const]`");
+            if def_id.is_local() {
+                let name = tcx.def_path_str(def_id);
+                err.span_suggestion(
+                    tcx.def_span(def_id).shrink_to_lo(),
+                    format!("add `#[type_const]` attribute to `{name}`"),
+                    format!("#[type_const]\n"),
+                    Applicability::MaybeIncorrect,
+                );
+            } else {
+                err.note("only consts marked with `#[type_const]` may be used in types");
+            }
+            Err(err.emit())
+        }
+    }
+
     fn lower_delegation_ty(&self, idx: hir::InferDelegationKind) -> Ty<'tcx> {
         let delegation_sig = self.tcx().inherit_sig_for_delegation_item(self.item_def_id());
         match idx {

compiler/rustc_hir_pretty/src/lib.rs

@@ -1158,9 +1158,12 @@ impl<'a> State<'a> {
             ConstArgKind::Anon(anon) => self.print_anon_const(anon),
             ConstArgKind::Error(_) => self.word("/*ERROR*/"),
             ConstArgKind::Infer(..) => self.word("_"),
-            ConstArgKind::Literal(node) => {
+            ConstArgKind::Literal { lit, negated } => {
+                if *negated {
+                    self.word("-");
+                }
                 let span = const_arg.span;
-                self.print_literal(&Spanned { span, node: *node })
+                self.print_literal(&Spanned { span, node: *lit })
             }
         }
     }

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -1439,7 +1439,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                         | hir::ConstArgKind::TupleCall(..)
                         | hir::ConstArgKind::Tup(..)
                         | hir::ConstArgKind::Path(..)
-                        | hir::ConstArgKind::Literal(..)
+                        | hir::ConstArgKind::Literal { .. }
                         | hir::ConstArgKind::Infer(..) => true,
                         hir::ConstArgKind::Anon(..) => false,
                     },

compiler/rustc_passes/Cargo.toml

@@ -13,7 +13,6 @@ rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
 rustc_expand = { path = "../rustc_expand" }
 rustc_feature = { path = "../rustc_feature" }
-rustc_fluent_macro = { path = "../rustc_fluent_macro" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_macros = { path = "../rustc_macros" }