From 698f8c2f01ea549d77d7dc3338a12e04c11057b9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:02:58 +0200 Subject: Adding upstream version 1.64.0+dfsg1. Signed-off-by: Daniel Baumann --- compiler/rustc_middle/src/mir/interpret/queries.rs | 217 +++++++++++++++++++++ 1 file changed, 217 insertions(+) create mode 100644 compiler/rustc_middle/src/mir/interpret/queries.rs (limited to 'compiler/rustc_middle/src/mir/interpret/queries.rs') diff --git a/compiler/rustc_middle/src/mir/interpret/queries.rs b/compiler/rustc_middle/src/mir/interpret/queries.rs new file mode 100644 index 000000000..786927e2d --- /dev/null +++ b/compiler/rustc_middle/src/mir/interpret/queries.rs @@ -0,0 +1,217 @@ +use super::{ErrorHandled, EvalToConstValueResult, EvalToValTreeResult, GlobalId}; + +use crate::mir; +use crate::ty::subst::InternalSubsts; +use crate::ty::visit::TypeVisitable; +use crate::ty::{self, query::TyCtxtAt, query::TyCtxtEnsure, TyCtxt}; +use rustc_hir::def_id::DefId; +use rustc_span::{Span, DUMMY_SP}; + +impl<'tcx> TyCtxt<'tcx> { + /// Evaluates a constant without providing any substitutions. This is useful to evaluate consts + /// that can't take any generic arguments like statics, const items or enum discriminants. If a + /// generic parameter is used within the constant `ErrorHandled::ToGeneric` will be returned. + #[instrument(skip(self), level = "debug")] + pub fn const_eval_poly(self, def_id: DefId) -> EvalToConstValueResult<'tcx> { + // In some situations def_id will have substitutions within scope, but they aren't allowed + // to be used. So we can't use `Instance::mono`, instead we feed unresolved substitutions + // into `const_eval` which will return `ErrorHandled::ToGeneric` if any of them are + // encountered. + let substs = InternalSubsts::identity_for_item(self, def_id); + let instance = ty::Instance::new(def_id, substs); + let cid = GlobalId { instance, promoted: None }; + let param_env = self.param_env(def_id).with_reveal_all_normalized(self); + self.const_eval_global_id(param_env, cid, None) + } + /// Resolves and evaluates a constant. + /// + /// The constant can be located on a trait like `::C`, in which case the given + /// substitutions and environment are used to resolve the constant. Alternatively if the + /// constant has generic parameters in scope the substitutions are used to evaluate the value of + /// the constant. For example in `fn foo() { let _ = [0; bar::()]; }` the repeat count + /// constant `bar::()` requires a substitution for `T`, if the substitution for `T` is still + /// too generic for the constant to be evaluated then `Err(ErrorHandled::TooGeneric)` is + /// returned. + #[instrument(level = "debug", skip(self))] + pub fn const_eval_resolve( + self, + param_env: ty::ParamEnv<'tcx>, + ct: ty::Unevaluated<'tcx>, + span: Option, + ) -> EvalToConstValueResult<'tcx> { + // Cannot resolve `Unevaluated` constants that contain inference + // variables. We reject those here since `resolve_opt_const_arg` + // would fail otherwise. + // + // When trying to evaluate constants containing inference variables, + // use `Infcx::const_eval_resolve` instead. + if ct.substs.has_infer_types_or_consts() { + bug!("did not expect inference variables here"); + } + + match ty::Instance::resolve_opt_const_arg(self, param_env, ct.def, ct.substs) { + Ok(Some(instance)) => { + let cid = GlobalId { instance, promoted: ct.promoted }; + self.const_eval_global_id(param_env, cid, span) + } + Ok(None) => Err(ErrorHandled::TooGeneric), + Err(error_reported) => Err(ErrorHandled::Reported(error_reported)), + } + } + + #[instrument(level = "debug", skip(self))] + pub fn const_eval_resolve_for_typeck( + self, + param_env: ty::ParamEnv<'tcx>, + ct: ty::Unevaluated<'tcx>, + span: Option, + ) -> EvalToValTreeResult<'tcx> { + // Cannot resolve `Unevaluated` constants that contain inference + // variables. We reject those here since `resolve_opt_const_arg` + // would fail otherwise. + // + // When trying to evaluate constants containing inference variables, + // use `Infcx::const_eval_resolve` instead. + if ct.substs.has_infer_types_or_consts() { + bug!("did not expect inference variables here"); + } + + match ty::Instance::resolve_opt_const_arg(self, param_env, ct.def, ct.substs) { + Ok(Some(instance)) => { + let cid = GlobalId { instance, promoted: ct.promoted }; + self.const_eval_global_id_for_typeck(param_env, cid, span) + } + Ok(None) => Err(ErrorHandled::TooGeneric), + Err(error_reported) => Err(ErrorHandled::Reported(error_reported)), + } + } + + pub fn const_eval_instance( + self, + param_env: ty::ParamEnv<'tcx>, + instance: ty::Instance<'tcx>, + span: Option, + ) -> EvalToConstValueResult<'tcx> { + self.const_eval_global_id(param_env, GlobalId { instance, promoted: None }, span) + } + + /// Evaluate a constant to a `ConstValue`. + #[instrument(skip(self), level = "debug")] + pub fn const_eval_global_id( + self, + param_env: ty::ParamEnv<'tcx>, + cid: GlobalId<'tcx>, + span: Option, + ) -> EvalToConstValueResult<'tcx> { + let param_env = param_env.with_const(); + // Const-eval shouldn't depend on lifetimes at all, so we can erase them, which should + // improve caching of queries. + let inputs = self.erase_regions(param_env.and(cid)); + if let Some(span) = span { + self.at(span).eval_to_const_value_raw(inputs) + } else { + self.eval_to_const_value_raw(inputs) + } + } + + /// Evaluate a constant to a type-level constant. + #[instrument(skip(self), level = "debug")] + pub fn const_eval_global_id_for_typeck( + self, + param_env: ty::ParamEnv<'tcx>, + cid: GlobalId<'tcx>, + span: Option, + ) -> EvalToValTreeResult<'tcx> { + let param_env = param_env.with_const(); + debug!(?param_env); + // Const-eval shouldn't depend on lifetimes at all, so we can erase them, which should + // improve caching of queries. + let inputs = self.erase_regions(param_env.and(cid)); + debug!(?inputs); + if let Some(span) = span { + self.at(span).eval_to_valtree(inputs) + } else { + self.eval_to_valtree(inputs) + } + } + + /// Evaluate a static's initializer, returning the allocation of the initializer's memory. + #[inline(always)] + pub fn eval_static_initializer( + self, + def_id: DefId, + ) -> Result, ErrorHandled> { + self.at(DUMMY_SP).eval_static_initializer(def_id) + } +} + +impl<'tcx> TyCtxtAt<'tcx> { + /// Evaluate a static's initializer, returning the allocation of the initializer's memory. + pub fn eval_static_initializer( + self, + def_id: DefId, + ) -> Result, ErrorHandled> { + trace!("eval_static_initializer: Need to compute {:?}", def_id); + assert!(self.is_static(def_id)); + let instance = ty::Instance::mono(*self, def_id); + let gid = GlobalId { instance, promoted: None }; + self.eval_to_allocation(gid, ty::ParamEnv::reveal_all()) + } + + /// Evaluate anything constant-like, returning the allocation of the final memory. + fn eval_to_allocation( + self, + gid: GlobalId<'tcx>, + param_env: ty::ParamEnv<'tcx>, + ) -> Result, ErrorHandled> { + let param_env = param_env.with_const(); + trace!("eval_to_allocation: Need to compute {:?}", gid); + let raw_const = self.eval_to_allocation_raw(param_env.and(gid))?; + Ok(self.global_alloc(raw_const.alloc_id).unwrap_memory()) + } +} + +impl<'tcx> TyCtxtEnsure<'tcx> { + /// Evaluates a constant without providing any substitutions. This is useful to evaluate consts + /// that can't take any generic arguments like statics, const items or enum discriminants. If a + /// generic parameter is used within the constant `ErrorHandled::ToGeneric` will be returned. + #[instrument(skip(self), level = "debug")] + pub fn const_eval_poly(self, def_id: DefId) { + // In some situations def_id will have substitutions within scope, but they aren't allowed + // to be used. So we can't use `Instance::mono`, instead we feed unresolved substitutions + // into `const_eval` which will return `ErrorHandled::ToGeneric` if any of them are + // encountered. + let substs = InternalSubsts::identity_for_item(self.tcx, def_id); + let instance = ty::Instance::new(def_id, substs); + let cid = GlobalId { instance, promoted: None }; + let param_env = + self.tcx.param_env(def_id).with_reveal_all_normalized(self.tcx).with_const(); + // Const-eval shouldn't depend on lifetimes at all, so we can erase them, which should + // improve caching of queries. + let inputs = self.tcx.erase_regions(param_env.and(cid)); + self.eval_to_const_value_raw(inputs) + } + + /// Evaluate a static's initializer, returning the allocation of the initializer's memory. + pub fn eval_static_initializer(self, def_id: DefId) { + trace!("eval_static_initializer: Need to compute {:?}", def_id); + assert!(self.tcx.is_static(def_id)); + let instance = ty::Instance::mono(self.tcx, def_id); + let gid = GlobalId { instance, promoted: None }; + let param_env = ty::ParamEnv::reveal_all().with_const(); + trace!("eval_to_allocation: Need to compute {:?}", gid); + self.eval_to_allocation_raw(param_env.and(gid)) + } +} + +impl<'tcx> TyCtxt<'tcx> { + /// Destructure a mir constant ADT or array into its variant index and its field values. + /// Panics if the destructuring fails, use `try_destructure_mir_constant` for fallible version. + pub fn destructure_mir_constant( + self, + param_env: ty::ParamEnv<'tcx>, + constant: mir::ConstantKind<'tcx>, + ) -> mir::DestructuredMirConstant<'tcx> { + self.try_destructure_mir_constant(param_env.and(constant)).unwrap() + } +} -- cgit v1.2.3