Rollup merge of rust-lang#109665 - fee1-dead-contrib:rm-remap-queries, r=oli-obk

Remove `remap_env_constness` in queries

This removes some of the complexities with const traits. rust-lang#88119 used to be caused by this but was fixed by `param_env = param_env.without_const()`.

Author: fee1-dead

compiler/rustc_macros/src/query.rs

@@ -112,9 +112,6 @@ struct QueryModifiers {
     /// Use a separate query provider for local and extern crates
     separate_provide_extern: Option<Ident>,
 
-    /// Always remap the ParamEnv's constness before hashing.
-    remap_env_constness: Option<Ident>,
-
     /// Generate a `feed` method to set the query's value from another query.
     feedable: Option<Ident>,
 }
@@ -130,7 +127,6 @@ fn parse_query_modifiers(input: ParseStream<'_>) -> Result<QueryModifiers> {
     let mut eval_always = None;
     let mut depth_limit = None;
     let mut separate_provide_extern = None;
-    let mut remap_env_constness = None;
     let mut feedable = None;
 
     while !input.is_empty() {
@@ -189,8 +185,6 @@ fn parse_query_modifiers(input: ParseStream<'_>) -> Result<QueryModifiers> {
             try_insert!(depth_limit = modifier);
         } else if modifier == "separate_provide_extern" {
             try_insert!(separate_provide_extern = modifier);
-        } else if modifier == "remap_env_constness" {
-            try_insert!(remap_env_constness = modifier);
         } else if modifier == "feedable" {
             try_insert!(feedable = modifier);
         } else {
@@ -211,7 +205,6 @@ fn parse_query_modifiers(input: ParseStream<'_>) -> Result<QueryModifiers> {
         eval_always,
         depth_limit,
         separate_provide_extern,
-        remap_env_constness,
         feedable,
     })
 }
@@ -332,7 +325,6 @@ pub fn rustc_queries(input: TokenStream) -> TokenStream {
             eval_always,
             depth_limit,
             separate_provide_extern,
-            remap_env_constness,
         );
 
         if modifiers.cache.is_some() {

compiler/rustc_middle/src/infer/canonical.rs

@@ -348,14 +348,6 @@ impl<'tcx, R> Canonical<'tcx, QueryResponse<'tcx, R>> {
     }
 }
 
-impl<'tcx, R> Canonical<'tcx, ty::ParamEnvAnd<'tcx, R>> {
-    #[inline]
-    pub fn without_const(mut self) -> Self {
-        self.value = self.value.without_const();
-        self
-    }
-}
-
 impl<'tcx, V> Canonical<'tcx, V> {
     /// Allows you to map the `value` of a canonical while keeping the
     /// same set of bound variables.

compiler/rustc_middle/src/query/mod.rs

@@ -1094,7 +1094,6 @@ rustc_queries! {
         key: ty::ParamEnvAnd<'tcx, mir::ConstantKind<'tcx>>
     ) -> Option<mir::DestructuredConstant<'tcx>> {
         desc { "destructuring MIR constant"}
-        remap_env_constness
     }
 
     /// Dereference a constant reference or raw pointer and turn the result into a constant
@@ -1103,7 +1102,6 @@ rustc_queries! {
         key: ty::ParamEnvAnd<'tcx, mir::ConstantKind<'tcx>>
     ) -> mir::ConstantKind<'tcx> {
         desc { "dereferencing MIR constant" }
-        remap_env_constness
     }
 
     query const_caller_location(key: (rustc_span::Symbol, u32, u32)) -> ConstValue<'tcx> {
@@ -1346,32 +1344,26 @@ rustc_queries! {
     /// `ty.is_copy()`, etc, since that will prune the environment where possible.
     query is_copy_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
         desc { "computing whether `{}` is `Copy`", env.value }
-        remap_env_constness
     }
     /// Query backing `Ty::is_sized`.
     query is_sized_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
         desc { "computing whether `{}` is `Sized`", env.value }
-        remap_env_constness
     }
     /// Query backing `Ty::is_freeze`.
     query is_freeze_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
         desc { "computing whether `{}` is freeze", env.value }
-        remap_env_constness
     }
     /// Query backing `Ty::is_unpin`.
     query is_unpin_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
         desc { "computing whether `{}` is `Unpin`", env.value }
-        remap_env_constness
     }
     /// Query backing `Ty::needs_drop`.
     query needs_drop_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
         desc { "computing whether `{}` needs drop", env.value }
-        remap_env_constness
     }
     /// Query backing `Ty::has_significant_drop_raw`.
     query has_significant_drop_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
         desc { "computing whether `{}` has a significant drop", env.value }
-        remap_env_constness
     }
 
     /// Query backing `Ty::is_structural_eq_shallow`.
@@ -1411,7 +1403,6 @@ rustc_queries! {
     ) -> Result<ty::layout::TyAndLayout<'tcx>, ty::layout::LayoutError<'tcx>> {
         depth_limit
         desc { "computing layout of `{}`", key.value }
-        remap_env_constness
     }
 
     /// Compute a `FnAbi` suitable for indirect calls, i.e. to `fn` pointers.
@@ -1422,7 +1413,6 @@ rustc_queries! {
         key: ty::ParamEnvAnd<'tcx, (ty::PolyFnSig<'tcx>, &'tcx ty::List<Ty<'tcx>>)>
     ) -> Result<&'tcx abi::call::FnAbi<'tcx, Ty<'tcx>>, ty::layout::FnAbiError<'tcx>> {
         desc { "computing call ABI of `{}` function pointers", key.value.0 }
-        remap_env_constness
     }
 
     /// Compute a `FnAbi` suitable for declaring/defining an `fn` instance, and for
@@ -1434,7 +1424,6 @@ rustc_queries! {
         key: ty::ParamEnvAnd<'tcx, (ty::Instance<'tcx>, &'tcx ty::List<Ty<'tcx>>)>
     ) -> Result<&'tcx abi::call::FnAbi<'tcx, Ty<'tcx>>, ty::layout::FnAbiError<'tcx>> {
         desc { "computing call ABI of `{}`", key.value.0 }
-        remap_env_constness
     }
 
     query dylib_dependency_formats(_: CrateNum)
@@ -1937,15 +1926,13 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "normalizing `{}`", goal.value.value }
-        remap_env_constness
     }
 
     /// Do not call this query directly: invoke `try_normalize_erasing_regions` instead.
     query try_normalize_generic_arg_after_erasing_regions(
         goal: ParamEnvAnd<'tcx, GenericArg<'tcx>>
     ) -> Result<GenericArg<'tcx>, NoSolution> {
         desc { "normalizing `{}`", goal.value }
-        remap_env_constness
     }
 
     query implied_outlives_bounds(
@@ -1955,7 +1942,6 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "computing implied outlives bounds for `{}`", goal.value.value }
-        remap_env_constness
     }
 
     /// Do not call this query directly:
@@ -1967,7 +1953,6 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "computing dropck types for `{}`", goal.value.value }
-        remap_env_constness
     }
 
     /// Do not call this query directly: invoke `infcx.predicate_may_hold()` or
@@ -1995,7 +1980,6 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "evaluating `type_op_ascribe_user_type` `{:?}`", goal.value.value }
-        remap_env_constness
     }
 
     /// Do not call this query directly: part of the `Eq` type-op
@@ -2006,7 +1990,6 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "evaluating `type_op_eq` `{:?}`", goal.value.value }
-        remap_env_constness
     }
 
     /// Do not call this query directly: part of the `Subtype` type-op
@@ -2017,7 +2000,6 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "evaluating `type_op_subtype` `{:?}`", goal.value.value }
-        remap_env_constness
     }
 
     /// Do not call this query directly: part of the `ProvePredicate` type-op
@@ -2038,7 +2020,6 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "normalizing `{}`", goal.value.value.value }
-        remap_env_constness
     }
 
     /// Do not call this query directly: part of the `Normalize` type-op
@@ -2049,7 +2030,6 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "normalizing `{:?}`", goal.value.value.value }
-        remap_env_constness
     }
 
     /// Do not call this query directly: part of the `Normalize` type-op
@@ -2060,7 +2040,6 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "normalizing `{:?}`", goal.value.value.value }
-        remap_env_constness
     }
 
     /// Do not call this query directly: part of the `Normalize` type-op
@@ -2071,7 +2050,6 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "normalizing `{:?}`", goal.value.value.value }
-        remap_env_constness
     }
 
     query subst_and_check_impossible_predicates(key: (DefId, SubstsRef<'tcx>)) -> bool {
@@ -2093,7 +2071,6 @@ rustc_queries! {
         goal: CanonicalTyGoal<'tcx>
     ) -> MethodAutoderefStepsResult<'tcx> {
         desc { "computing autoderef types for `{}`", goal.value.value }
-        remap_env_constness
     }
 
     query supported_target_features(_: CrateNum) -> &'tcx FxHashMap<String, Option<Symbol>> {
@@ -2138,7 +2115,6 @@ rustc_queries! {
         key: ty::ParamEnvAnd<'tcx, (DefId, SubstsRef<'tcx>)>
     ) -> Result<Option<ty::Instance<'tcx>>, ErrorGuaranteed> {
         desc { "resolving instance `{}`", ty::Instance::new(key.value.0, key.value.1) }
-        remap_env_constness
     }
 
     query resolve_instance_of_const_arg(
@@ -2148,7 +2124,6 @@ rustc_queries! {
             "resolving instance of the const argument `{}`",
             ty::Instance::new(key.value.0.to_def_id(), key.value.2),
         }
-        remap_env_constness
     }
 
     query reveal_opaque_types_in_bounds(key: &'tcx ty::List<ty::Predicate<'tcx>>) -> &'tcx ty::List<ty::Predicate<'tcx>> {

compiler/rustc_middle/src/ty/mod.rs

@@ -1850,12 +1850,6 @@ impl<'tcx, T> ParamEnvAnd<'tcx, T> {
     pub fn into_parts(self) -> (ParamEnv<'tcx>, T) {
         (self.param_env, self.value)
     }
-
-    #[inline]
-    pub fn without_const(mut self) -> Self {
-        self.param_env = self.param_env.without_const();
-        self
-    }
 }
 
 #[derive(Copy, Clone, Debug, HashStable, Encodable, Decodable)]

compiler/rustc_middle/src/ty/query.rs

@@ -202,16 +202,6 @@ macro_rules! separate_provide_extern_default {
     };
 }
 
-macro_rules! opt_remap_env_constness {
-    ([][$name:ident]) => {};
-    ([(remap_env_constness) $($rest:tt)*][$name:ident]) => {
-        let $name = $name.without_const();
-    };
-    ([$other:tt $($modifiers:tt)*][$name:ident]) => {
-        opt_remap_env_constness!([$($modifiers)*][$name])
-    };
-}
-
 macro_rules! define_callbacks {
     (
      $($(#[$attr:meta])*
@@ -353,7 +343,6 @@ macro_rules! define_callbacks {
             #[inline(always)]
             pub fn $name(self, key: query_helper_param_ty!($($K)*)) {
                 let key = key.into_query_param();
-                opt_remap_env_constness!([$($modifiers)*][key]);
 
                 match try_get_cached(self.tcx, &self.tcx.query_system.caches.$name, &key) {
                     Some(_) => return,
@@ -372,7 +361,6 @@ macro_rules! define_callbacks {
             #[inline(always)]
             pub fn $name(self, key: query_helper_param_ty!($($K)*)) {
                 let key = key.into_query_param();
-                opt_remap_env_constness!([$($modifiers)*][key]);
 
                 match try_get_cached(self.tcx, &self.tcx.query_system.caches.$name, &key) {
                     Some(_) => return,
@@ -402,7 +390,6 @@ macro_rules! define_callbacks {
             pub fn $name(self, key: query_helper_param_ty!($($K)*)) -> $V
             {
                 let key = key.into_query_param();
-                opt_remap_env_constness!([$($modifiers)*][key]);
 
                 restore::<$V>(match try_get_cached(self.tcx, &self.tcx.query_system.caches.$name, &key) {
                     Some(value) => value,
@@ -492,7 +479,6 @@ macro_rules! define_feedable {
             #[inline(always)]
             pub fn $name(self, value: query_provided::$name<'tcx>) -> $V {
                 let key = self.key().into_query_param();
-                opt_remap_env_constness!([$($modifiers)*][key]);
 
                 let tcx = self.tcx;
                 let erased = query_provided_to_value::$name(tcx, value);

compiler/rustc_trait_selection/src/traits/query/type_op/prove_predicate.rs

@@ -32,14 +32,8 @@ impl<'tcx> super::QueryTypeOp<'tcx> for ProvePredicate<'tcx> {
 
     fn perform_query(
         tcx: TyCtxt<'tcx>,
-        mut canonicalized: Canonical<'tcx, ParamEnvAnd<'tcx, Self>>,
+        canonicalized: Canonical<'tcx, ParamEnvAnd<'tcx, Self>>,
     ) -> Fallible<CanonicalQueryResponse<'tcx, ()>> {
-        match canonicalized.value.value.predicate.kind().skip_binder() {
-            ty::PredicateKind::Clause(ty::Clause::Trait(pred)) => {
-                canonicalized.value.param_env.remap_constness_with(pred.constness);
-            }
-            _ => canonicalized.value.param_env = canonicalized.value.param_env.without_const(),
-        }
         tcx.type_op_prove_predicate(canonicalized)
     }
 }

compiler/rustc_traits/src/type_op.rs

@@ -89,6 +89,7 @@ fn relate_mir_and_user_substs<'tcx>(
     def_id: hir::def_id::DefId,
     user_substs: UserSubsts<'tcx>,
 ) -> Result<(), NoSolution> {
+    let param_env = param_env.without_const();
     let UserSubsts { user_self_ty, substs } = user_substs;
     let tcx = ocx.infcx.tcx;
     let cause = ObligationCause::dummy_with_span(span);

tests/ui/rfc-2632-const-trait-impl/trait-method-ptr-in-consts-ice.rs

@@ -0,0 +1,23 @@
+// check-pass
+
+struct LazyLock<T> {
+    data: (Option<T>, fn() -> T),
+}
+
+impl<T> LazyLock<T> {
+    pub const fn new(f: fn() -> T) -> LazyLock<T> {
+        LazyLock { data: (None, f) }
+    }
+}
+
+struct A<T = i32>(Option<T>);
+
+impl<T> Default for A<T> {
+    fn default() -> Self {
+        A(None)
+    }
+}
+
+static EMPTY_SET: LazyLock<A<i32>> = LazyLock::new(A::default);
+
+fn main() {}