Auto merge of #89854 - cuviper:beta-next, r=Mark-Simulacrum

[beta] backports

- 2229: Consume IfLet expr #89282
- Wrapper for -Z gcc-ld=lld to invoke rust-lld with the correct flavor #89288
- Fix unsound optimization with explicit variant discriminants #89489
- Fix stabilization version for bindings_after_at #89605
- Turn vtable_allocation() into a query #89619
- Revert "Stabilize Iterator::intersperse()" #89638
- Ignore type of projections for upvar capturing #89648
- ~~Add Poll::ready and~~ revert stabilization of task::ready! #89651
- CI: Use mirror for libisl downloads for more docker dist builds #89661
-  Use correct edition for panic in [debug_]assert!(). #89622
-  Switch to our own mirror of libisl plus ct-ng oldconfig fixes #89599
-  Emit item no type error even if type inference fails #89585
-  Revert enum discriminants #89884

Author: bors

Cargo.lock

@@ -1966,6 +1966,10 @@ dependencies = [
  "walkdir",
 ]
 
+[[package]]
+name = "lld-wrapper"
+version = "0.1.0"
+
 [[package]]
 name = "lock_api"
 version = "0.4.1"

Cargo.toml

@@ -35,6 +35,7 @@ members = [
   "src/tools/expand-yaml-anchors",
   "src/tools/jsondocck",
   "src/tools/html-checker",
+  "src/tools/lld-wrapper",
 ]
 
 exclude = [

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -1,11 +1,11 @@
 use rustc_ast as ast;
 use rustc_ast::visit::{self, AssocCtxt, FnCtxt, FnKind, Visitor};
 use rustc_ast::{AssocTyConstraint, AssocTyConstraintKind, NodeId};
-use rustc_ast::{PatKind, RangeEnd};
+use rustc_ast::{PatKind, RangeEnd, VariantData};
 use rustc_errors::struct_span_err;
 use rustc_feature::{AttributeGate, BUILTIN_ATTRIBUTE_MAP};
 use rustc_feature::{Features, GateIssue};
-use rustc_session::parse::feature_err_issue;
+use rustc_session::parse::{feature_err, feature_err_issue};
 use rustc_session::Session;
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::sym;
@@ -218,6 +218,46 @@ impl<'a> PostExpansionVisitor<'a> {
         }
     }
 
+    fn maybe_report_invalid_custom_discriminants(&self, variants: &[ast::Variant]) {
+        let has_fields = variants.iter().any(|variant| match variant.data {
+            VariantData::Tuple(..) | VariantData::Struct(..) => true,
+            VariantData::Unit(..) => false,
+        });
+
+        let discriminant_spans = variants
+            .iter()
+            .filter(|variant| match variant.data {
+                VariantData::Tuple(..) | VariantData::Struct(..) => false,
+                VariantData::Unit(..) => true,
+            })
+            .filter_map(|variant| variant.disr_expr.as_ref().map(|c| c.value.span))
+            .collect::<Vec<_>>();
+
+        if !discriminant_spans.is_empty() && has_fields {
+            let mut err = feature_err(
+                &self.sess.parse_sess,
+                sym::arbitrary_enum_discriminant,
+                discriminant_spans.clone(),
+                "custom discriminant values are not allowed in enums with tuple or struct variants",
+            );
+            for sp in discriminant_spans {
+                err.span_label(sp, "disallowed custom discriminant");
+            }
+            for variant in variants.iter() {
+                match &variant.data {
+                    VariantData::Struct(..) => {
+                        err.span_label(variant.span, "struct variant defined here");
+                    }
+                    VariantData::Tuple(..) => {
+                        err.span_label(variant.span, "tuple variant defined here");
+                    }
+                    VariantData::Unit(..) => {}
+                }
+            }
+            err.emit();
+        }
+    }
+
     fn check_gat(&self, generics: &ast::Generics, span: Span) {
         if !generics.params.is_empty() {
             gate_feature_post!(
@@ -362,6 +402,26 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
                 }
             }
 
+            ast::ItemKind::Enum(ast::EnumDef { ref variants, .. }, ..) => {
+                for variant in variants {
+                    match (&variant.data, &variant.disr_expr) {
+                        (ast::VariantData::Unit(..), _) => {}
+                        (_, Some(disr_expr)) => gate_feature_post!(
+                            &self,
+                            arbitrary_enum_discriminant,
+                            disr_expr.value.span,
+                            "discriminants on non-unit variants are experimental"
+                        ),
+                        _ => {}
+                    }
+                }
+
+                let has_feature = self.features.arbitrary_enum_discriminant;
+                if !has_feature && !i.span.allows_unstable(sym::arbitrary_enum_discriminant) {
+                    self.maybe_report_invalid_custom_discriminants(&variants);
+                }
+            }
+
             ast::ItemKind::Impl(box ast::ImplKind {
                 polarity, defaultness, ref of_trait, ..
             }) => {

compiler/rustc_builtin_macros/src/assert.rs

@@ -1,10 +1,10 @@
-use rustc_errors::{Applicability, DiagnosticBuilder};
-
+use crate::panic::use_panic_2021;
 use rustc_ast::ptr::P;
 use rustc_ast::token;
 use rustc_ast::tokenstream::{DelimSpan, TokenStream};
 use rustc_ast::{self as ast, *};
 use rustc_ast_pretty::pprust;
+use rustc_errors::{Applicability, DiagnosticBuilder};
 use rustc_expand::base::*;
 use rustc_parse::parser::Parser;
 use rustc_span::symbol::{sym, Ident, Symbol};
@@ -28,7 +28,7 @@ pub fn expand_assert<'cx>(
     let sp = cx.with_call_site_ctxt(span);
 
     let panic_call = if let Some(tokens) = custom_message {
-        let path = if span.rust_2021() {
+        let path = if use_panic_2021(span) {
             // On edition 2021, we always call `$crate::panic::panic_2021!()`.
             Path {
                 span: sp,

compiler/rustc_builtin_macros/src/panic.rs

@@ -2,6 +2,7 @@ use rustc_ast::ptr::P;
 use rustc_ast::tokenstream::{DelimSpan, TokenStream};
 use rustc_ast::*;
 use rustc_expand::base::*;
+use rustc_span::edition::Edition;
 use rustc_span::symbol::sym;
 use rustc_span::Span;
 
@@ -19,7 +20,7 @@ pub fn expand_panic<'cx>(
     sp: Span,
     tts: TokenStream,
 ) -> Box<dyn MacResult + 'cx> {
-    let panic = if sp.rust_2021() { sym::panic_2021 } else { sym::panic_2015 };
+    let panic = if use_panic_2021(sp) { sym::panic_2021 } else { sym::panic_2015 };
 
     let sp = cx.with_call_site_ctxt(sp);
 
@@ -46,3 +47,19 @@ pub fn expand_panic<'cx>(
         ),
     )
 }
+
+pub fn use_panic_2021(mut span: Span) -> bool {
+    // To determine the editon, we check the first span up the expansion
+    // stack that does not have #[allow_internal_unstable(edition_panic)].
+    // (To avoid using the edition of e.g. the assert!() or debug_assert!() definition.)
+    loop {
+        let expn = span.ctxt().outer_expn_data();
+        if let Some(features) = expn.allow_internal_unstable {
+            if features.iter().any(|&f| f == sym::edition_panic) {
+                span = expn.call_site;
+                continue;
+            }
+        }
+        break expn.edition >= Edition::Edition2021;
+    }
+}

compiler/rustc_codegen_cranelift/src/vtable.rs

@@ -68,7 +68,7 @@ pub(crate) fn get_vtable<'tcx>(
     ty: Ty<'tcx>,
     trait_ref: Option<ty::PolyExistentialTraitRef<'tcx>>,
 ) -> Value {
-    let alloc_id = fx.tcx.vtable_allocation(ty, trait_ref);
+    let alloc_id = fx.tcx.vtable_allocation((ty, trait_ref));
     let data_id =
         data_id_for_alloc_id(&mut fx.constants_cx, &mut *fx.module, alloc_id, Mutability::Not);
     let local_data_id = fx.module.declare_data_in_func(data_id, &mut fx.bcx.func);

compiler/rustc_codegen_ssa/src/meth.rs

@@ -72,7 +72,7 @@ pub fn get_vtable<'tcx, Cx: CodegenMethods<'tcx>>(
         return val;
     }
 
-    let vtable_alloc_id = tcx.vtable_allocation(ty, trait_ref);
+    let vtable_alloc_id = tcx.vtable_allocation((ty, trait_ref));
     let vtable_allocation = tcx.global_alloc(vtable_alloc_id).unwrap_memory();
     let vtable_const = cx.const_data_from_alloc(vtable_allocation);
     let align = cx.data_layout().pointer_align.abi;

compiler/rustc_error_codes/src/error_codes/E0732.md

@@ -3,6 +3,8 @@ An `enum` with a discriminant must specify a `#[repr(inttype)]`.
 Erroneous code example:
 
 ```compile_fail,E0732
+#![feature(arbitrary_enum_discriminant)]
+
 enum Enum { // error!
     Unit = 1,
     Tuple() = 2,
@@ -18,6 +20,8 @@ is a well-defined way to extract a variant's discriminant from a value;
 for instance:
 
 ```
+#![feature(arbitrary_enum_discriminant)]
+
 #[repr(u8)]
 enum Enum {
     Unit = 3,

compiler/rustc_feature/src/accepted.rs

@@ -289,13 +289,11 @@ declare_features! (
     (accepted, member_constraints, "1.54.0", Some(61997), None),
     /// Allows bindings in the subpattern of a binding pattern.
     /// For example, you can write `x @ Some(y)`.
-    (accepted, bindings_after_at, "1.54.0", Some(65490), None),
+    (accepted, bindings_after_at, "1.56.0", Some(65490), None),
     /// Allows calling `transmute` in const fn
     (accepted, const_fn_transmute, "1.56.0", Some(53605), None),
     /// Allows accessing fields of unions inside `const` functions.
     (accepted, const_fn_union, "1.56.0", Some(51909), None),
-    /// Allows explicit discriminants on non-unit enum variants.
-    (accepted, arbitrary_enum_discriminant, "1.56.0", Some(60553), None),
 
     // -------------------------------------------------------------------------
     // feature-group-end: accepted features

compiler/rustc_feature/src/active.rs

@@ -468,6 +468,9 @@ declare_features! (
     /// Allows #[repr(transparent)] on unions (RFC 2645).
     (active, transparent_unions, "1.37.0", Some(60405), None),
 
+    /// Allows explicit discriminants on non-unit enum variants.
+    (active, arbitrary_enum_discriminant, "1.37.0", Some(60553), None),
+
     /// Allows `async || body` closures.
     (active, async_closure, "1.37.0", Some(62290), None),
 

compiler/rustc_middle/src/query/mod.rs

@@ -1006,6 +1006,13 @@ rustc_queries! {
             key.1, key.0 }
     }
 
+    query vtable_allocation(key: (Ty<'tcx>, Option<ty::PolyExistentialTraitRef<'tcx>>)) -> mir::interpret::AllocId {
+        desc { |tcx| "vtable const allocation for <{} as {}>",
+            key.0,
+            key.1.map(|trait_ref| format!("{}", trait_ref)).unwrap_or("_".to_owned())
+        }
+    }
+
     query codegen_fulfill_obligation(
         key: (ty::ParamEnv<'tcx>, ty::PolyTraitRef<'tcx>)
     ) -> Result<ImplSource<'tcx, ()>, ErrorReported> {

compiler/rustc_middle/src/ty/context.rs

@@ -10,7 +10,7 @@ use crate::middle;
 use crate::middle::cstore::EncodedMetadata;
 use crate::middle::resolve_lifetime::{self, LifetimeScopeForPath, ObjectLifetimeDefault};
 use crate::middle::stability;
-use crate::mir::interpret::{self, AllocId, Allocation, ConstValue, Scalar};
+use crate::mir::interpret::{self, Allocation, ConstValue, Scalar};
 use crate::mir::{Body, Field, Local, Place, PlaceElem, ProjectionKind, Promoted};
 use crate::thir::Thir;
 use crate::traits;
@@ -1062,9 +1062,6 @@ pub struct GlobalCtxt<'tcx> {
     layout_interner: ShardedHashMap<&'tcx Layout, ()>,
 
     output_filenames: Arc<OutputFilenames>,
-
-    pub(super) vtables_cache:
-        Lock<FxHashMap<(Ty<'tcx>, Option<ty::PolyExistentialTraitRef<'tcx>>), AllocId>>,
 }
 
 impl<'tcx> TyCtxt<'tcx> {
@@ -1212,7 +1209,6 @@ impl<'tcx> TyCtxt<'tcx> {
             const_stability_interner: Default::default(),
             alloc_map: Lock::new(interpret::AllocMap::new()),
             output_filenames: Arc::new(output_filenames),
-            vtables_cache: Default::default(),
         }
     }
 

compiler/rustc_middle/src/ty/mod.rs

@@ -2046,6 +2046,7 @@ pub fn provide(providers: &mut ty::query::Providers) {
         trait_impls_of: trait_def::trait_impls_of_provider,
         type_uninhabited_from: inhabitedness::type_uninhabited_from,
         const_param_default: consts::const_param_default,
+        vtable_allocation: vtable::vtable_allocation_provider,
         ..*providers
     };
 }

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -2177,6 +2177,7 @@ forward_display_to_print! {
     // because `for<'tcx>` isn't possible yet.
     ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>,
     ty::Binder<'tcx, ty::TraitRef<'tcx>>,
+    ty::Binder<'tcx, ty::ExistentialTraitRef<'tcx>>,
     ty::Binder<'tcx, TraitRefPrintOnlyTraitPath<'tcx>>,
     ty::Binder<'tcx, ty::FnSig<'tcx>>,
     ty::Binder<'tcx, ty::TraitPredicate<'tcx>>,