Auto merge of rust-lang#127079 - GuillaumeGomez:rollup-ciimias, r=GuillaumeGomez

Rollup of 10 pull requests

Successful merges:

 - rust-lang#123714 (Add test for fn pointer duplication.)
 - rust-lang#124091 (Update AST validation module docs)
 - rust-lang#126963 (Add basic Serde serialization capabilities to Stable MIR)
 - rust-lang#127015 (Switch back `non_local_definitions` lint to allow-by-default)
 - rust-lang#127016 (docs: check if the disambiguator matches its suffix)
 - rust-lang#127029 (Fix Markdown tables in platform-support.md)
 - rust-lang#127032 (Enable const casting for `f16` and `f128`)
 - rust-lang#127041 (Migrate `run-make/override-aliased-flags` to `rmake.rs`)
 - rust-lang#127045 (Rename `super_predicates_of` and similar queries to `explicit_*` to note that they're not elaborated)
 - rust-lang#127075 (rustc_data_structures: Explicitly check for 64-bit atomics support)

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

Author: bors

Cargo.lock

@@ -5263,6 +5263,7 @@ name = "stable_mir"
 version = "0.1.0-preview"
 dependencies = [
  "scoped-tls",
+ "serde",
 ]
 
 [[package]]

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -1,10 +1,20 @@
-// Validate AST before lowering it to HIR.
-//
-// This pass is supposed to catch things that fit into AST data structures,
-// but not permitted by the language. It runs after expansion when AST is frozen,
-// so it can check for erroneous constructions produced by syntax extensions.
-// This pass is supposed to perform only simple checks not requiring name resolution
-// or type checking or some other kind of complex analysis.
+//! Validate AST before lowering it to HIR.
+//!
+//! This pass intends to check that the constructed AST is *syntactically valid* to allow the rest
+//! of the compiler to assume that the AST is valid. These checks cannot be performed during parsing
+//! because attribute macros are allowed to accept certain pieces of invalid syntax such as a
+//! function without body outside of a trait definition:
+//!
+//! ```ignore (illustrative)
+//! #[my_attribute]
+//! mod foo {
+//!     fn missing_body();
+//! }
+//! ```
+//!
+//! These checks are run post-expansion, after AST is frozen, to be able to check for erroneous
+//! constructions produced by proc macros. This pass is only intended for simple checks that do not
+//! require name resolution or type checking, or other kinds of complex analysis.
 
 use itertools::{Either, Itertools};
 use rustc_ast::ptr::P;

compiler/rustc_const_eval/src/interpret/cast.rs

@@ -1,6 +1,6 @@
 use std::assert_matches::assert_matches;
 
-use rustc_apfloat::ieee::{Double, Single};
+use rustc_apfloat::ieee::{Double, Half, Quad, Single};
 use rustc_apfloat::{Float, FloatConvert};
 use rustc_middle::mir::interpret::{InterpResult, PointerArithmetic, Scalar};
 use rustc_middle::mir::CastKind;
@@ -187,10 +187,10 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             bug!("FloatToFloat/FloatToInt cast: source type {} is not a float type", src.layout.ty)
         };
         let val = match fty {
-            FloatTy::F16 => unimplemented!("f16_f128"),
+            FloatTy::F16 => self.cast_from_float(src.to_scalar().to_f16()?, cast_to.ty),
             FloatTy::F32 => self.cast_from_float(src.to_scalar().to_f32()?, cast_to.ty),
             FloatTy::F64 => self.cast_from_float(src.to_scalar().to_f64()?, cast_to.ty),
-            FloatTy::F128 => unimplemented!("f16_f128"),
+            FloatTy::F128 => self.cast_from_float(src.to_scalar().to_f128()?, cast_to.ty),
         };
         Ok(ImmTy::from_scalar(val, cast_to))
     }
@@ -296,18 +296,18 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             Float(fty) if signed => {
                 let v = v as i128;
                 match fty {
-                    FloatTy::F16 => unimplemented!("f16_f128"),
+                    FloatTy::F16 => Scalar::from_f16(Half::from_i128(v).value),
                     FloatTy::F32 => Scalar::from_f32(Single::from_i128(v).value),
                     FloatTy::F64 => Scalar::from_f64(Double::from_i128(v).value),
-                    FloatTy::F128 => unimplemented!("f16_f128"),
+                    FloatTy::F128 => Scalar::from_f128(Quad::from_i128(v).value),
                 }
             }
             // unsigned int -> float
             Float(fty) => match fty {
-                FloatTy::F16 => unimplemented!("f16_f128"),
+                FloatTy::F16 => Scalar::from_f16(Half::from_u128(v).value),
                 FloatTy::F32 => Scalar::from_f32(Single::from_u128(v).value),
                 FloatTy::F64 => Scalar::from_f64(Double::from_u128(v).value),
-                FloatTy::F128 => unimplemented!("f16_f128"),
+                FloatTy::F128 => Scalar::from_f128(Quad::from_u128(v).value),
             },
 
             // u8 -> char
@@ -321,7 +321,12 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
     /// Low-level cast helper function. Converts an apfloat `f` into int or float types.
     fn cast_from_float<F>(&self, f: F, dest_ty: Ty<'tcx>) -> Scalar<M::Provenance>
     where
-        F: Float + Into<Scalar<M::Provenance>> + FloatConvert<Single> + FloatConvert<Double>,
+        F: Float
+            + Into<Scalar<M::Provenance>>
+            + FloatConvert<Half>
+            + FloatConvert<Single>
+            + FloatConvert<Double>
+            + FloatConvert<Quad>,
     {
         use rustc_type_ir::TyKind::*;
 
@@ -358,10 +363,12 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             }
             // float -> float
             Float(fty) => match fty {
-                FloatTy::F16 => unimplemented!("f16_f128"),
+                FloatTy::F16 => Scalar::from_f16(adjust_nan(self, f, f.convert(&mut false).value)),
                 FloatTy::F32 => Scalar::from_f32(adjust_nan(self, f, f.convert(&mut false).value)),
                 FloatTy::F64 => Scalar::from_f64(adjust_nan(self, f, f.convert(&mut false).value)),
-                FloatTy::F128 => unimplemented!("f16_f128"),
+                FloatTy::F128 => {
+                    Scalar::from_f128(adjust_nan(self, f, f.convert(&mut false).value))
+                }
             },
             // That's it.
             _ => span_bug!(self.cur_span(), "invalid float to {} cast", dest_ty),

compiler/rustc_data_structures/Cargo.toml

@@ -50,7 +50,7 @@ libc = "0.2"
 memmap2 = "0.2.1"
 # tidy-alphabetical-end
 
-[target.'cfg(any(target_arch = "mips", target_arch = "powerpc", target_arch = "sparc"))'.dependencies]
+[target.'cfg(not(target_has_atomic = "64"))'.dependencies]
 portable-atomic = "1.5.1"
 
 [features]

compiler/rustc_data_structures/src/marker.rs

@@ -147,14 +147,13 @@ cfg_match! {
             [crate::owned_slice::OwnedSlice]
         );
 
-        // MIPS, PowerPC and SPARC platforms with 32-bit pointers do not
-        // have AtomicU64 type.
-        #[cfg(not(any(target_arch = "powerpc", target_arch = "powerpc", target_arch = "sparc")))]
+        // Use portable AtomicU64 for targets without native 64-bit atomics
+        #[cfg(target_has_atomic = "64")]
         already_sync!(
             [std::sync::atomic::AtomicU64]
         );
 
-        #[cfg(any(target_arch = "mips", target_arch = "powerpc", target_arch = "sparc"))]
+        #[cfg(not(target_has_atomic = "64"))]
         already_sync!(
             [portable_atomic::AtomicU64]
         );

compiler/rustc_data_structures/src/sync.rs

@@ -270,12 +270,11 @@ cfg_match! {
 
         pub use std::sync::atomic::{AtomicBool, AtomicUsize, AtomicU32};
 
-        // MIPS, PowerPC and SPARC platforms with 32-bit pointers do not
-        // have AtomicU64 type.
-        #[cfg(not(any(target_arch = "mips", target_arch = "powerpc", target_arch = "sparc")))]
+        // Use portable AtomicU64 for targets without native 64-bit atomics
+        #[cfg(target_has_atomic = "64")]
         pub use std::sync::atomic::AtomicU64;
 
-        #[cfg(any(target_arch = "mips", target_arch = "powerpc", target_arch = "sparc"))]
+        #[cfg(not(target_has_atomic = "64"))]
         pub use portable_atomic::AtomicU64;
 
         pub use std::sync::Arc as Lrc;

compiler/rustc_hir_analysis/src/collect.rs

@@ -70,10 +70,10 @@ pub fn provide(providers: &mut Providers) {
         predicates_of: predicates_of::predicates_of,
         predicates_defined_on,
         explicit_predicates_of: predicates_of::explicit_predicates_of,
-        super_predicates_of: predicates_of::super_predicates_of,
-        implied_predicates_of: predicates_of::implied_predicates_of,
-        super_predicates_that_define_assoc_item:
-            predicates_of::super_predicates_that_define_assoc_item,
+        explicit_super_predicates_of: predicates_of::explicit_super_predicates_of,
+        explicit_implied_predicates_of: predicates_of::explicit_implied_predicates_of,
+        explicit_supertraits_containing_assoc_item:
+            predicates_of::explicit_supertraits_containing_assoc_item,
         trait_explicit_predicates_and_bounds: predicates_of::trait_explicit_predicates_and_bounds,
         type_param_predicates: predicates_of::type_param_predicates,
         trait_def,
@@ -691,14 +691,14 @@ fn lower_item(tcx: TyCtxt<'_>, item_id: hir::ItemId) {
         hir::ItemKind::Trait(..) => {
             tcx.ensure().generics_of(def_id);
             tcx.ensure().trait_def(def_id);
-            tcx.at(it.span).super_predicates_of(def_id);
+            tcx.at(it.span).explicit_super_predicates_of(def_id);
             tcx.ensure().predicates_of(def_id);
             tcx.ensure().associated_items(def_id);
         }
         hir::ItemKind::TraitAlias(..) => {
             tcx.ensure().generics_of(def_id);
-            tcx.at(it.span).implied_predicates_of(def_id);
-            tcx.at(it.span).super_predicates_of(def_id);
+            tcx.at(it.span).explicit_implied_predicates_of(def_id);
+            tcx.at(it.span).explicit_super_predicates_of(def_id);
             tcx.ensure().predicates_of(def_id);
         }
         hir::ItemKind::Struct(struct_def, _) | hir::ItemKind::Union(struct_def, _) => {

compiler/rustc_hir_analysis/src/collect/predicates_of.rs

@@ -519,21 +519,21 @@ pub(super) fn explicit_predicates_of<'tcx>(
 /// Ensures that the super-predicates of the trait with a `DefId`
 /// of `trait_def_id` are lowered and stored. This also ensures that
 /// the transitive super-predicates are lowered.
-pub(super) fn super_predicates_of(
+pub(super) fn explicit_super_predicates_of(
     tcx: TyCtxt<'_>,
     trait_def_id: LocalDefId,
 ) -> ty::GenericPredicates<'_> {
     implied_predicates_with_filter(tcx, trait_def_id.to_def_id(), PredicateFilter::SelfOnly)
 }
 
-pub(super) fn super_predicates_that_define_assoc_item(
+pub(super) fn explicit_supertraits_containing_assoc_item(
     tcx: TyCtxt<'_>,
     (trait_def_id, assoc_name): (DefId, Ident),
 ) -> ty::GenericPredicates<'_> {
     implied_predicates_with_filter(tcx, trait_def_id, PredicateFilter::SelfThatDefines(assoc_name))
 }
 
-pub(super) fn implied_predicates_of(
+pub(super) fn explicit_implied_predicates_of(
     tcx: TyCtxt<'_>,
     trait_def_id: LocalDefId,
 ) -> ty::GenericPredicates<'_> {
@@ -560,7 +560,7 @@ pub(super) fn implied_predicates_with_filter(
         // if `assoc_name` is None, then the query should've been redirected to an
         // external provider
         assert!(matches!(filter, PredicateFilter::SelfThatDefines(_)));
-        return tcx.super_predicates_of(trait_def_id);
+        return tcx.explicit_super_predicates_of(trait_def_id);
     };
 
     let Node::Item(item) = tcx.hir_node_by_def_id(trait_def_id) else {
@@ -601,7 +601,7 @@ pub(super) fn implied_predicates_with_filter(
                 if let ty::ClauseKind::Trait(bound) = pred.kind().skip_binder()
                     && bound.polarity == ty::PredicatePolarity::Positive
                 {
-                    tcx.at(span).super_predicates_of(bound.def_id());
+                    tcx.at(span).explicit_super_predicates_of(bound.def_id());
                 }
             }
         }
@@ -611,7 +611,7 @@ pub(super) fn implied_predicates_with_filter(
                 if let ty::ClauseKind::Trait(bound) = pred.kind().skip_binder()
                     && bound.polarity == ty::PredicatePolarity::Positive
                 {
-                    tcx.at(span).implied_predicates_of(bound.def_id());
+                    tcx.at(span).explicit_implied_predicates_of(bound.def_id());
                 }
             }
         }

compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs

@@ -1760,7 +1760,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
             if let Some(assoc_item) = trait_defines_associated_item_named(def_id) {
                 break Some((bound_vars.into_iter().collect(), assoc_item));
             }
-            let predicates = tcx.super_predicates_that_define_assoc_item((def_id, assoc_name));
+            let predicates = tcx.explicit_supertraits_containing_assoc_item((def_id, assoc_name));
             let obligations = predicates.predicates.iter().filter_map(|&(pred, _)| {
                 let bound_predicate = pred.kind();
                 match bound_predicate.skip_binder() {

compiler/rustc_infer/src/traits/util.rs

@@ -275,10 +275,10 @@ impl<'tcx, O: Elaboratable<'tcx>> Elaborator<'tcx, O> {
                 }
                 // Get predicates implied by the trait, or only super predicates if we only care about self predicates.
                 let predicates = match self.mode {
-                    Filter::All => tcx.implied_predicates_of(data.def_id()),
-                    Filter::OnlySelf => tcx.super_predicates_of(data.def_id()),
+                    Filter::All => tcx.explicit_implied_predicates_of(data.def_id()),
+                    Filter::OnlySelf => tcx.explicit_super_predicates_of(data.def_id()),
                     Filter::OnlySelfThatDefines(ident) => {
-                        tcx.super_predicates_that_define_assoc_item((data.def_id(), ident))
+                        tcx.explicit_supertraits_containing_assoc_item((data.def_id(), ident))
                     }
                 };
 
@@ -420,7 +420,7 @@ pub fn transitive_bounds<'tcx>(
 
 /// A specialized variant of `elaborate` that only elaborates trait references that may
 /// define the given associated item with the name `assoc_name`. It uses the
-/// `super_predicates_that_define_assoc_item` query to avoid enumerating super-predicates that
+/// `explicit_supertraits_containing_assoc_item` query to avoid enumerating super-predicates that
 /// aren't related to `assoc_item`. This is used when resolving types like `Self::Item` or
 /// `T::Item` and helps to avoid cycle errors (see e.g. #35237).
 pub fn transitive_bounds_that_define_assoc_item<'tcx>(