Combine individual limit queries into single limits query

Author: Aaron1011

Diff for: compiler/rustc_interface/src/passes.rs

@@ -872,13 +872,11 @@ fn analysis(tcx: TyCtxt<'_>, (): ()) -> Result<()> {
                 });
             },
             {
-                // Mark the attributes as used, and ensure that
-                // they're not ill-formed. We force these queries
-                // to run, since they might not otherwise get called.
-                tcx.ensure().recursion_limit(());
-                tcx.ensure().move_size_limit(());
-                tcx.ensure().type_length_limit(());
-                tcx.ensure().const_eval_limit(());
+                // We force these querie to run,
+                // since they might not otherwise get called.
+                // This marks the corresponding crate-level attributes
+                // as used, and ensures that their values are valid.
+                tcx.ensure().limits(());
             }
         );
     });

Diff for: compiler/rustc_middle/src/middle/limits.rs

@@ -12,20 +12,29 @@
 use crate::bug;
 use crate::ty;
 use rustc_ast::Attribute;
-use rustc_session::Limit;
 use rustc_session::Session;
+use rustc_session::{Limit, Limits};
 use rustc_span::symbol::{sym, Symbol};
 
 use std::num::IntErrorKind;
 
 pub fn provide(providers: &mut ty::query::Providers) {
-    providers.recursion_limit = |tcx, ()| get_recursion_limit(tcx.hir().krate_attrs(), tcx.sess);
-    providers.move_size_limit =
-        |tcx, ()| get_limit(tcx.hir().krate_attrs(), tcx.sess, sym::move_size_limit, 0).0;
-    providers.type_length_limit =
-        |tcx, ()| get_limit(tcx.hir().krate_attrs(), tcx.sess, sym::type_length_limit, 1048576);
-    providers.const_eval_limit =
-        |tcx, ()| get_limit(tcx.hir().krate_attrs(), tcx.sess, sym::const_eval_limit, 1_000_000);
+    providers.limits = |tcx, ()| Limits {
+        recursion_limit: get_recursion_limit(tcx.hir().krate_attrs(), tcx.sess),
+        move_size_limit: get_limit(tcx.hir().krate_attrs(), tcx.sess, sym::move_size_limit, 0),
+        type_length_limit: get_limit(
+            tcx.hir().krate_attrs(),
+            tcx.sess,
+            sym::type_length_limit,
+            1048576,
+        ),
+        const_eval_limit: get_limit(
+            tcx.hir().krate_attrs(),
+            tcx.sess,
+            sym::const_eval_limit,
+            1_000_000,
+        ),
+    }
 }
 
 pub fn get_recursion_limit(krate_attrs: &[Attribute], sess: &Session) -> Limit {

Diff for: compiler/rustc_middle/src/query/mod.rs

@@ -1713,25 +1713,7 @@ rustc_queries! {
         desc { "conservatively checking if {:?} is privately uninhabited", key }
     }
 
-    /// The maximum recursion limit for potentially infinitely recursive
-    /// operations such as auto-dereference and monomorphization.
-    query recursion_limit(key: ()) -> Limit {
-        desc { "looking up recursion limit" }
-    }
-
-    /// The size at which the `large_assignments` lint starts
-    /// being emitted.
-    query move_size_limit(key: ()) -> usize {
-        desc { "looking up move size limit" }
-    }
-
-    /// The maximum length of types during monomorphization.
-    query type_length_limit(key: ()) -> Limit {
-        desc { "looking up type length limit" }
-    }
-
-    /// The maximum blocks a const expression can evaluate.
-    query const_eval_limit(key: ()) -> Limit {
-        desc { "looking up const eval limit" }
+    query limits(key: ()) -> Limits {
+        desc { "looking up limits" }
     }
 }

Diff for: compiler/rustc_middle/src/ty/context.rs

@@ -53,6 +53,7 @@ use rustc_middle::ty::OpaqueTypeKey;
 use rustc_serialize::opaque::{FileEncodeResult, FileEncoder};
 use rustc_session::config::{BorrowckMode, CrateType, OutputFilenames};
 use rustc_session::lint::{Level, Lint};
+use rustc_session::Limit;
 use rustc_session::Session;
 use rustc_span::def_id::StableCrateId;
 use rustc_span::source_map::MultiSpan;
@@ -1569,6 +1570,22 @@ impl<'tcx> TyCtxt<'tcx> {
             def_kind => (def_kind.article(), def_kind.descr(def_id)),
         }
     }
+
+    pub fn type_length_limit(self) -> Limit {
+        self.limits(()).type_length_limit
+    }
+
+    pub fn recursion_limit(self) -> Limit {
+        self.limits(()).recursion_limit
+    }
+
+    pub fn move_size_limit(self) -> Limit {
+        self.limits(()).move_size_limit
+    }
+
+    pub fn const_eval_limit(self) -> Limit {
+        self.limits(()).const_eval_limit
+    }
 }
 
 /// A trait implemented for all `X<'a>` types that can be safely and

Diff for: compiler/rustc_middle/src/ty/layout.rs

@@ -221,7 +221,7 @@ fn layout_raw<'tcx>(
     ty::tls::with_related_context(tcx, move |icx| {
         let (param_env, ty) = query.into_parts();
 
-        if !tcx.recursion_limit(()).value_within_limit(icx.layout_depth) {
+        if !tcx.recursion_limit().value_within_limit(icx.layout_depth) {
             tcx.sess.fatal(&format!("overflow representing the type `{}`", ty));
         }
 

Diff for: compiler/rustc_middle/src/ty/print/pretty.rs

@@ -1437,7 +1437,7 @@ impl<F: fmt::Write> Printer<'tcx> for FmtPrinter<'_, 'tcx, F> {
     }
 
     fn print_type(mut self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error> {
-        let type_length_limit = self.tcx.type_length_limit(());
+        let type_length_limit = self.tcx.type_length_limit();
         if type_length_limit.value_within_limit(self.printed_type_count) {
             self.printed_type_count += 1;
             self.pretty_print_type(ty)

Diff for: compiler/rustc_middle/src/ty/query/mod.rs

@@ -49,7 +49,7 @@ use rustc_serialize::opaque;
 use rustc_session::config::{EntryFnType, OptLevel, OutputFilenames, SymbolManglingVersion};
 use rustc_session::utils::NativeLibKind;
 use rustc_session::CrateDisambiguator;
-use rustc_session::Limit;
+use rustc_session::Limits;
 use rustc_target::spec::PanicStrategy;
 
 use rustc_ast as ast;

Diff for: compiler/rustc_middle/src/ty/util.rs

@@ -206,7 +206,7 @@ impl<'tcx> TyCtxt<'tcx> {
         mut ty: Ty<'tcx>,
         normalize: impl Fn(Ty<'tcx>) -> Ty<'tcx>,
     ) -> Ty<'tcx> {
-        let recursion_limit = self.recursion_limit(());
+        let recursion_limit = self.recursion_limit();
         for iteration in 0.. {
             if !recursion_limit.value_within_limit(iteration) {
                 return self.ty_error_with_message(

Diff for: compiler/rustc_mir/src/const_eval/eval_queries.rs

@@ -98,7 +98,7 @@ pub(super) fn mk_eval_cx<'mir, 'tcx>(
         tcx,
         root_span,
         param_env,
-        CompileTimeInterpreter::new(tcx.const_eval_limit(())),
+        CompileTimeInterpreter::new(tcx.const_eval_limit()),
         MemoryExtra { can_access_statics },
     )
 }
@@ -300,7 +300,7 @@ pub fn eval_to_allocation_raw_provider<'tcx>(
         tcx,
         tcx.def_span(def.did),
         key.param_env,
-        CompileTimeInterpreter::new(tcx.const_eval_limit(())),
+        CompileTimeInterpreter::new(tcx.const_eval_limit()),
         // Statics (and promoteds inside statics) may access other statics, because unlike consts
         // they do not have to behave "as if" they were evaluated at runtime.
         MemoryExtra { can_access_statics: is_static },

Diff for: compiler/rustc_mir/src/interpret/eval_context.rs

@@ -392,7 +392,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             tcx: tcx.at(root_span),
             param_env,
             memory: Memory::new(tcx, memory_extra),
-            recursion_limit: tcx.recursion_limit(()),
+            recursion_limit: tcx.recursion_limit(),
         }
     }
 

Diff for: compiler/rustc_mir/src/monomorphize/collector.rs

@@ -295,7 +295,7 @@ pub fn collect_crate_mono_items(
 
     let mut visited = MTLock::new(FxHashSet::default());
     let mut inlining_map = MTLock::new(InliningMap::new());
-    let recursion_limit = tcx.recursion_limit(());
+    let recursion_limit = tcx.recursion_limit();
 
     {
         let visited: MTRef<'_, _> = &mut visited;
@@ -587,7 +587,7 @@ fn check_type_length_limit<'tcx>(tcx: TyCtxt<'tcx>, instance: Instance<'tcx>) {
     // which means that rustc basically hangs.
     //
     // Bail out in these cases to avoid that bad user experience.
-    if !tcx.type_length_limit(()).value_within_limit(type_length) {
+    if !tcx.type_length_limit().value_within_limit(type_length) {
         let (shrunk, written_to_path) = shrunk_instance_name(tcx, &instance, 32, 32);
         let msg = format!("reached the type-length limit while instantiating `{}`", shrunk);
         let mut diag = tcx.sess.struct_span_fatal(tcx.def_span(instance.def_id()), &msg);
@@ -824,7 +824,7 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirNeighborCollector<'a, 'tcx> {
 
     fn visit_operand(&mut self, operand: &mir::Operand<'tcx>, location: Location) {
         self.super_operand(operand, location);
-        let limit = self.tcx.move_size_limit(());
+        let limit = self.tcx.move_size_limit().0;
         if limit == 0 {
             return;
         }

Diff for: compiler/rustc_mir/src/transform/inline/cycle.rs

@@ -133,7 +133,7 @@ crate fn mir_callgraph_reachable(
         &mut Vec::new(),
         &mut FxHashSet::default(),
         &mut FxHashMap::default(),
-        tcx.recursion_limit(()),
+        tcx.recursion_limit(),
     )
 }
 

Diff for: compiler/rustc_session/src/session.rs

@@ -112,6 +112,20 @@ impl Mul<usize> for Limit {
     }
 }
 
+#[derive(Clone, Copy, Debug, HashStable_Generic)]
+pub struct Limits {
+    /// The maximum recursion limit for potentially infinitely recursive
+    /// operations such as auto-dereference and monomorphization.
+    pub recursion_limit: Limit,
+    /// The size at which the `large_assignments` lint starts
+    /// being emitted.
+    pub move_size_limit: Limit,
+    /// The maximum length of types during monomorphization.
+    pub type_length_limit: Limit,
+    /// The maximum blocks a const expression can evaluate.
+    pub const_eval_limit: Limit,
+}
+
 /// Represents the data associated with a compilation
 /// session for a single crate.
 pub struct Session {

Diff for: compiler/rustc_trait_selection/src/autoderef.rs

@@ -53,7 +53,7 @@ impl<'a, 'tcx> Iterator for Autoderef<'a, 'tcx> {
         }
 
         // If we have reached the recursion limit, error gracefully.
-        if !tcx.recursion_limit(()).value_within_limit(self.state.steps.len()) {
+        if !tcx.recursion_limit().value_within_limit(self.state.steps.len()) {
             if !self.silence_errors {
                 report_autoderef_recursion_limit_error(tcx, self.span, self.state.cur_ty);
             }
@@ -217,7 +217,7 @@ impl<'a, 'tcx> Autoderef<'a, 'tcx> {
 
 pub fn report_autoderef_recursion_limit_error<'tcx>(tcx: TyCtxt<'tcx>, span: Span, ty: Ty<'tcx>) {
     // We've reached the recursion limit, error gracefully.
-    let suggested_limit = tcx.recursion_limit(()) * 2;
+    let suggested_limit = tcx.recursion_limit() * 2;
     let msg = format!("reached the recursion limit while auto-dereferencing `{:?}`", ty);
     let error_id = (DiagnosticMessageId::ErrorId(55), Some(span), msg);
     let fresh = tcx.sess.one_time_diagnostics.borrow_mut().insert(error_id);

Diff for: compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs

@@ -2310,7 +2310,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
     }
 
     fn suggest_new_overflow_limit(&self, err: &mut DiagnosticBuilder<'_>) {
-        let current_limit = self.tcx.recursion_limit(());
+        let current_limit = self.tcx.recursion_limit();
         let suggested_limit = current_limit * 2;
         err.help(&format!(
             "consider adding a `#![recursion_limit=\"{}\"]` attribute to your crate (`{}`)",

Diff for: compiler/rustc_trait_selection/src/traits/project.rs

@@ -344,7 +344,7 @@ impl<'a, 'b, 'tcx> TypeFolder<'tcx> for AssocTypeNormalizer<'a, 'b, 'tcx> {
                     Reveal::UserFacing => ty,
 
                     Reveal::All => {
-                        let recursion_limit = self.tcx().recursion_limit(());
+                        let recursion_limit = self.tcx().recursion_limit();
                         if !recursion_limit.value_within_limit(self.depth) {
                             let obligation = Obligation::with_depth(
                                 self.cause.clone(),
@@ -726,7 +726,7 @@ fn project_type<'cx, 'tcx>(
 ) -> Result<ProjectedTy<'tcx>, ProjectionTyError<'tcx>> {
     debug!(?obligation, "project_type");
 
-    if !selcx.tcx().recursion_limit(()).value_within_limit(obligation.recursion_depth) {
+    if !selcx.tcx().recursion_limit().value_within_limit(obligation.recursion_depth) {
         debug!("project: overflow!");
         // This should really be an immediate error, but some existing code
         // relies on being able to recover from this.

Diff for: compiler/rustc_trait_selection/src/traits/query/normalize.rs

@@ -116,7 +116,7 @@ impl<'cx, 'tcx> TypeFolder<'tcx> for QueryNormalizer<'cx, 'tcx> {
                     Reveal::UserFacing => ty,
 
                     Reveal::All => {
-                        let recursion_limit = self.tcx().recursion_limit(());
+                        let recursion_limit = self.tcx().recursion_limit();
                         if !recursion_limit.value_within_limit(self.anon_depth) {
                             let obligation = Obligation::with_depth(
                                 self.cause.clone(),

Diff for: compiler/rustc_trait_selection/src/traits/select/mod.rs

@@ -993,7 +993,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         obligation: &Obligation<'tcx, T>,
         error_obligation: &Obligation<'tcx, V>,
     ) -> Result<(), OverflowError> {
-        if !self.infcx.tcx.recursion_limit(()).value_within_limit(obligation.recursion_depth) {
+        if !self.infcx.tcx.recursion_limit().value_within_limit(obligation.recursion_depth) {
             match self.query_mode {
                 TraitQueryMode::Standard => {
                     self.infcx().report_overflow_error(error_obligation, true);

Diff for: compiler/rustc_traits/src/dropck_outlives.rs

@@ -163,7 +163,7 @@ fn dtorck_constraint_for_ty<'tcx>(
 ) -> Result<(), NoSolution> {
     debug!("dtorck_constraint_for_ty({:?}, {:?}, {:?}, {:?})", span, for_ty, depth, ty);
 
-    if !tcx.recursion_limit(()).value_within_limit(depth) {
+    if !tcx.recursion_limit().value_within_limit(depth) {
         constraints.overflows.push(ty);
         return Ok(());
     }

Diff for: compiler/rustc_ty_utils/src/needs_drop.rs

@@ -63,7 +63,7 @@ impl<'tcx, F> NeedsDropTypes<'tcx, F> {
             seen_tys,
             query_ty: ty,
             unchecked_tys: vec![(ty, 0)],
-            recursion_limit: tcx.recursion_limit(()),
+            recursion_limit: tcx.recursion_limit(),
             adt_components,
         }
     }