Rollup of 11 pull requests

Cargo.lock

@@ -3604,13 +3604,13 @@ dependencies = [
  "rustc_query_system",
  "rustc_resolve",
  "rustc_session",
- "rustc_smir",
  "rustc_span",
  "rustc_target",
  "rustc_trait_selection",
  "rustc_ty_utils",
  "serde_json",
  "shlex",
+ "stable_mir",
  "tracing",
  "windows 0.59.0",
 ]
@@ -4515,6 +4515,7 @@ dependencies = [
  "rustc_session",
  "rustc_span",
  "rustc_transmute",
+ "rustc_type_ir",
  "smallvec",
  "thin-vec",
  "tracing",

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -514,6 +514,7 @@ pub fn check_crate(krate: &ast::Crate, sess: &Session, features: &Features) {
     gate_all!(contracts_internals, "contract internal machinery is for internal use only");
     gate_all!(where_clause_attrs, "attributes in `where` clause are unstable");
     gate_all!(super_let, "`super let` is experimental");
+    gate_all!(frontmatter, "frontmatters are experimental");
 
     if !visitor.features.never_patterns() {
         if let Some(spans) = spans.get(&sym::never_patterns) {

compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs

@@ -1282,7 +1282,7 @@ fn codegen_regular_intrinsic_call<'tcx>(
                     intrinsic.name,
                 );
             }
-            return Err(Instance::new(instance.def_id(), instance.args));
+            return Err(Instance::new_raw(instance.def_id(), instance.args));
         }
     }
 

compiler/rustc_codegen_gcc/src/intrinsic/mod.rs

@@ -399,7 +399,7 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'a, 'gcc, 'tc
             }
 
             // Fall back to default body
-            _ => return Err(Instance::new(instance.def_id(), instance.args)),
+            _ => return Err(Instance::new_raw(instance.def_id(), instance.args)),
         };
 
         if !fn_abi.ret.is_ignore() {

compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/unused.rs

@@ -157,7 +157,7 @@ fn make_dummy_instance<'tcx>(tcx: TyCtxt<'tcx>, local_def_id: LocalDefId) -> ty:
     let def_id = local_def_id.to_def_id();
 
     // Make a dummy instance that fills in all generics with placeholders.
-    ty::Instance::new(
+    ty::Instance::new_raw(
         def_id,
         ty::GenericArgs::for_item(tcx, def_id, |param, _| {
             if let ty::GenericParamDefKind::Lifetime = param.kind {

compiler/rustc_codegen_llvm/src/intrinsic.rs

@@ -613,7 +613,7 @@ impl<'ll, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
             _ => {
                 debug!("unknown intrinsic '{}' -- falling back to default body", name);
                 // Call the fallback body instead of generating the intrinsic code
-                return Err(ty::Instance::new(instance.def_id(), instance.args));
+                return Err(ty::Instance::new_raw(instance.def_id(), instance.args));
             }
         };
 

compiler/rustc_codegen_ssa/src/back/symbol_export.rs

@@ -612,7 +612,7 @@ pub(crate) fn symbol_name_for_instance_in_crate<'tcx>(
         ExportedSymbol::Generic(def_id, args) => {
             rustc_symbol_mangling::symbol_name_for_instance_in_crate(
                 tcx,
-                Instance::new(def_id, args),
+                Instance::new_raw(def_id, args),
                 instantiating_crate,
             )
         }
@@ -660,7 +660,7 @@ fn calling_convention_for_symbol<'tcx>(
             None
         }
         ExportedSymbol::NonGeneric(def_id) => Some(Instance::mono(tcx, def_id)),
-        ExportedSymbol::Generic(def_id, args) => Some(Instance::new(def_id, args)),
+        ExportedSymbol::Generic(def_id, args) => Some(Instance::new_raw(def_id, args)),
         // DropGlue always use the Rust calling convention and thus follow the target's default
         // symbol decoration scheme.
         ExportedSymbol::DropGlue(..) => None,

compiler/rustc_codegen_ssa/src/base.rs

@@ -457,7 +457,13 @@ where
                 rustc_hir::InlineAsmOperand::SymFn { expr } => {
                     let ty = cx.tcx().typeck(item_id.owner_id).expr_ty(expr);
                     let instance = match ty.kind() {
-                        &ty::FnDef(def_id, args) => Instance::new(def_id, args),
+                        &ty::FnDef(def_id, args) => Instance::expect_resolve(
+                            cx.tcx(),
+                            ty::TypingEnv::fully_monomorphized(),
+                            def_id,
+                            args,
+                            expr.span,
+                        ),
                         _ => span_bug!(*op_sp, "asm sym is not a function"),
                     };
 

compiler/rustc_codegen_ssa/src/mir/naked_asm.rs

@@ -95,7 +95,9 @@ fn inline_to_global_operand<'a, 'tcx, Cx: LayoutOf<'tcx, LayoutOfResult = TyAndL
             );
 
             let instance = match mono_type.kind() {
-                &ty::FnDef(def_id, args) => Instance::new(def_id, args),
+                &ty::FnDef(def_id, args) => {
+                    Instance::expect_resolve(cx.tcx(), cx.typing_env(), def_id, args, value.span)
+                }
                 _ => bug!("asm sym is not a function"),
             };
 

compiler/rustc_driver_impl/Cargo.toml

@@ -44,13 +44,13 @@ rustc_privacy = { path = "../rustc_privacy" }
 rustc_query_system = { path = "../rustc_query_system" }
 rustc_resolve = { path = "../rustc_resolve" }
 rustc_session = { path = "../rustc_session" }
-rustc_smir = { path = "../rustc_smir" }
 rustc_span = { path = "../rustc_span" }
 rustc_target = { path = "../rustc_target" }
 rustc_trait_selection = { path = "../rustc_trait_selection" }
 rustc_ty_utils = { path = "../rustc_ty_utils" }
 serde_json = "1.0.59"
 shlex = "1.0"
+stable_mir = { path = "../stable_mir", features = ["rustc_internal"] }
 tracing = { version = "0.1.35" }
 # tidy-alphabetical-end
 

compiler/rustc_driver_impl/src/pretty.rs

@@ -10,8 +10,8 @@ use rustc_middle::ty::{self, TyCtxt};
 use rustc_mir_build::thir::print::{thir_flat, thir_tree};
 use rustc_session::Session;
 use rustc_session::config::{OutFileName, PpHirMode, PpMode, PpSourceMode};
-use rustc_smir::rustc_internal::pretty::write_smir_pretty;
 use rustc_span::{FileName, Ident};
+use stable_mir::rustc_internal::pretty::write_smir_pretty;
 use tracing::debug;
 use {rustc_ast as ast, rustc_hir_pretty as pprust_hir};
 

compiler/rustc_feature/src/unstable.rs

@@ -510,6 +510,8 @@ declare_features! (
     (incomplete, fn_delegation, "1.76.0", Some(118212)),
     /// Allows impls for the Freeze trait.
     (internal, freeze_impls, "1.78.0", Some(121675)),
+    /// Frontmatter `---` blocks for use by external tools.
+    (unstable, frontmatter, "CURRENT_RUSTC_VERSION", Some(136889)),
     /// Allows defining gen blocks and `gen fn`.
     (unstable, gen_blocks, "1.75.0", Some(117078)),
     /// Infer generic args for both consts and types.

compiler/rustc_hir_analysis/src/lib.rs

@@ -216,7 +216,7 @@ pub fn check_crate(tcx: TyCtxt<'_>) {
                 check::maybe_check_static_with_link_section(tcx, item_def_id);
             }
             DefKind::Const if tcx.generics_of(item_def_id).is_empty() => {
-                let instance = ty::Instance::new(item_def_id.into(), ty::GenericArgs::empty());
+                let instance = ty::Instance::new_raw(item_def_id.into(), ty::GenericArgs::empty());
                 let cid = GlobalId { instance, promoted: None };
                 let typing_env = ty::TypingEnv::fully_monomorphized();
                 tcx.ensure_ok().eval_to_const_value_raw(typing_env.as_query_input(cid));

compiler/rustc_infer/src/infer/context.rs

@@ -121,28 +121,28 @@ impl<'tcx> rustc_type_ir::InferCtxtLike for InferCtxt<'tcx> {
         self.enter_forall(value, f)
     }
 
-    fn equate_ty_vids_raw(&self, a: rustc_type_ir::TyVid, b: rustc_type_ir::TyVid) {
+    fn equate_ty_vids_raw(&self, a: ty::TyVid, b: ty::TyVid) {
         self.inner.borrow_mut().type_variables().equate(a, b);
     }
 
-    fn equate_int_vids_raw(&self, a: rustc_type_ir::IntVid, b: rustc_type_ir::IntVid) {
+    fn equate_int_vids_raw(&self, a: ty::IntVid, b: ty::IntVid) {
         self.inner.borrow_mut().int_unification_table().union(a, b);
     }
 
-    fn equate_float_vids_raw(&self, a: rustc_type_ir::FloatVid, b: rustc_type_ir::FloatVid) {
+    fn equate_float_vids_raw(&self, a: ty::FloatVid, b: ty::FloatVid) {
         self.inner.borrow_mut().float_unification_table().union(a, b);
     }
 
-    fn equate_const_vids_raw(&self, a: rustc_type_ir::ConstVid, b: rustc_type_ir::ConstVid) {
+    fn equate_const_vids_raw(&self, a: ty::ConstVid, b: ty::ConstVid) {
         self.inner.borrow_mut().const_unification_table().union(a, b);
     }
 
     fn instantiate_ty_var_raw<R: PredicateEmittingRelation<Self>>(
         &self,
         relation: &mut R,
         target_is_expected: bool,
-        target_vid: rustc_type_ir::TyVid,
-        instantiation_variance: rustc_type_ir::Variance,
+        target_vid: ty::TyVid,
+        instantiation_variance: ty::Variance,
         source_ty: Ty<'tcx>,
     ) -> RelateResult<'tcx, ()> {
         self.instantiate_ty_var(
@@ -154,27 +154,19 @@ impl<'tcx> rustc_type_ir::InferCtxtLike for InferCtxt<'tcx> {
         )
     }
 
-    fn instantiate_int_var_raw(
-        &self,
-        vid: rustc_type_ir::IntVid,
-        value: rustc_type_ir::IntVarValue,
-    ) {
+    fn instantiate_int_var_raw(&self, vid: ty::IntVid, value: ty::IntVarValue) {
         self.inner.borrow_mut().int_unification_table().union_value(vid, value);
     }
 
-    fn instantiate_float_var_raw(
-        &self,
-        vid: rustc_type_ir::FloatVid,
-        value: rustc_type_ir::FloatVarValue,
-    ) {
+    fn instantiate_float_var_raw(&self, vid: ty::FloatVid, value: ty::FloatVarValue) {
         self.inner.borrow_mut().float_unification_table().union_value(vid, value);
     }
 
     fn instantiate_const_var_raw<R: PredicateEmittingRelation<Self>>(
         &self,
         relation: &mut R,
         target_is_expected: bool,
-        target_vid: rustc_type_ir::ConstVid,
+        target_vid: ty::ConstVid,
         source_ct: ty::Const<'tcx>,
     ) -> RelateResult<'tcx, ()> {
         self.instantiate_const_var(relation, target_is_expected, target_vid, source_ct)

compiler/rustc_infer/src/infer/outlives/obligations.rs

@@ -63,11 +63,11 @@ use rustc_data_structures::undo_log::UndoLogs;
 use rustc_middle::bug;
 use rustc_middle::mir::ConstraintCategory;
 use rustc_middle::traits::query::NoSolution;
+use rustc_middle::ty::outlives::{Component, push_outlives_components};
 use rustc_middle::ty::{
     self, GenericArgKind, GenericArgsRef, PolyTypeOutlivesPredicate, Region, Ty, TyCtxt,
     TypeFoldable as _, TypeVisitableExt,
 };
-use rustc_type_ir::outlives::{Component, push_outlives_components};
 use smallvec::smallvec;
 use tracing::{debug, instrument};
 

compiler/rustc_infer/src/infer/outlives/verify.rs

@@ -1,7 +1,7 @@
 use std::assert_matches::assert_matches;
 
+use rustc_middle::ty::outlives::{Component, compute_alias_components_recursive};
 use rustc_middle::ty::{self, OutlivesPredicate, Ty, TyCtxt};
-use rustc_type_ir::outlives::{Component, compute_alias_components_recursive};
 use smallvec::smallvec;
 use tracing::{debug, instrument, trace};
 

compiler/rustc_infer/src/infer/relate/mod.rs

@@ -2,9 +2,8 @@
 //! (except for some relations used for diagnostics and heuristics in the compiler).
 //! As well as the implementation of `Relate` for interned things (`Ty`/`Const`/etc).
 
-pub use rustc_middle::ty::relate::RelateResult;
-pub use rustc_type_ir::relate::combine::PredicateEmittingRelation;
-pub use rustc_type_ir::relate::*;
+pub use rustc_middle::ty::relate::combine::PredicateEmittingRelation;
+pub use rustc_middle::ty::relate::{RelateResult, *};
 
 mod generalize;
 mod higher_ranked;

compiler/rustc_infer/src/infer/relate/type_relating.rs

@@ -3,9 +3,8 @@ use rustc_middle::ty::relate::combine::{super_combine_consts, super_combine_tys}
 use rustc_middle::ty::relate::{
     Relate, RelateResult, TypeRelation, relate_args_invariantly, relate_args_with_variances,
 };
-use rustc_middle::ty::{self, Ty, TyCtxt, TyVar};
+use rustc_middle::ty::{self, DelayedSet, Ty, TyCtxt, TyVar};
 use rustc_span::Span;
-use rustc_type_ir::data_structures::DelayedSet;
 use tracing::{debug, instrument};
 
 use crate::infer::BoundRegionConversionTime::HigherRankedType;

compiler/rustc_infer/src/infer/resolve.rs

@@ -1,9 +1,8 @@
 use rustc_middle::bug;
 use rustc_middle::ty::{
-    self, Const, FallibleTypeFolder, InferConst, Ty, TyCtxt, TypeFoldable, TypeFolder,
+    self, Const, DelayedMap, FallibleTypeFolder, InferConst, Ty, TyCtxt, TypeFoldable, TypeFolder,
     TypeSuperFoldable, TypeVisitableExt,
 };
-use rustc_type_ir::data_structures::DelayedMap;
 
 use super::{FixupError, FixupResult, InferCtxt};
 

compiler/rustc_infer/src/infer/snapshot/fudge.rs

@@ -3,9 +3,8 @@ use std::ops::Range;
 use rustc_data_structures::{snapshot_vec as sv, unify as ut};
 use rustc_middle::ty::{
     self, ConstVid, FloatVid, IntVid, RegionVid, Ty, TyCtxt, TyVid, TypeFoldable, TypeFolder,
-    TypeSuperFoldable,
+    TypeSuperFoldable, TypeVisitableExt,
 };
-use rustc_type_ir::TypeVisitableExt;
 use tracing::instrument;
 use ut::UnifyKey;
 

compiler/rustc_infer/src/traits/util.rs

@@ -1,7 +1,7 @@
 use rustc_data_structures::fx::FxHashSet;
+pub use rustc_middle::ty::elaborate::*;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_span::{Ident, Span};
-pub use rustc_type_ir::elaborate::*;
 
 use crate::traits::{self, Obligation, ObligationCauseCode, PredicateObligation};
 

compiler/rustc_lexer/src/cursor.rs

@@ -1,5 +1,10 @@
 use std::str::Chars;
 
+pub enum FrontmatterAllowed {
+    Yes,
+    No,
+}
+
 /// Peekable iterator over a char sequence.
 ///
 /// Next characters can be peeked via `first` method,
@@ -8,17 +13,19 @@ pub struct Cursor<'a> {
     len_remaining: usize,
     /// Iterator over chars. Slightly faster than a &str.
     chars: Chars<'a>,
+    pub(crate) frontmatter_allowed: FrontmatterAllowed,
     #[cfg(debug_assertions)]
     prev: char,
 }
 
 pub(crate) const EOF_CHAR: char = '\0';
 
 impl<'a> Cursor<'a> {
-    pub fn new(input: &'a str) -> Cursor<'a> {
+    pub fn new(input: &'a str, frontmatter_allowed: FrontmatterAllowed) -> Cursor<'a> {
         Cursor {
             len_remaining: input.len(),
             chars: input.chars(),
+            frontmatter_allowed,
             #[cfg(debug_assertions)]
             prev: EOF_CHAR,
         }
@@ -95,6 +102,11 @@ impl<'a> Cursor<'a> {
         Some(c)
     }
 
+    /// Moves to a substring by a number of bytes.
+    pub(crate) fn bump_bytes(&mut self, n: usize) {
+        self.chars = self.as_str()[n..].chars();
+    }
+
     /// Eats symbols while predicate returns true or until the end of file is reached.
     pub(crate) fn eat_while(&mut self, mut predicate: impl FnMut(char) -> bool) {
         // It was tried making optimized version of this for eg. line comments, but