Query-ify global limit attribute handling

Author: Aaron1011

compiler/rustc_interface/src/passes.rs

@@ -211,10 +211,6 @@ pub fn register_plugins<'a>(
         });
     }
 
-    sess.time("recursion_limit", || {
-        middle::limits::update_limits(sess, &krate);
-    });
-
     let mut lint_store = rustc_lint::new_lint_store(
         sess.opts.debugging_opts.no_interleave_lints,
         sess.unstable_options(),
@@ -311,9 +307,11 @@ pub fn configure_and_expand(
 
         // Create the config for macro expansion
         let features = sess.features_untracked();
+        let recursion_limit =
+            rustc_middle::middle::limits::get_recursion_limit(&krate.attrs, &sess);
         let cfg = rustc_expand::expand::ExpansionConfig {
             features: Some(&features),
-            recursion_limit: sess.recursion_limit(),
+            recursion_limit,
             trace_mac: sess.opts.debugging_opts.trace_macros,
             should_test: sess.opts.test,
             span_debug: sess.opts.debugging_opts.span_debug,
@@ -872,6 +870,15 @@ fn analysis(tcx: TyCtxt<'_>, (): ()) -> Result<()> {
                     tcx.ensure().check_mod_unstable_api_usage(module);
                     tcx.ensure().check_mod_const_bodies(module);
                 });
+            },
+            {
+                // 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(());
             }
         );
     });

compiler/rustc_middle/src/ich/hcx.rs

@@ -245,6 +245,8 @@ impl<'a> rustc_span::HashStableContext for StableHashingContext<'a> {
     }
 }
 
+impl rustc_session::HashStableContext for StableHashingContext<'a> {}
+
 pub fn hash_stable_trait_impls<'a>(
     hcx: &mut StableHashingContext<'a>,
     hasher: &mut StableHasher,

compiler/rustc_middle/src/middle/limits.rs

@@ -10,38 +10,37 @@
 //! just peeks and looks for that attribute.
 
 use crate::bug;
-use rustc_ast as ast;
-use rustc_data_structures::sync::OnceCell;
+use crate::ty;
+use rustc_ast::Attribute;
+use rustc_session::Limit;
 use rustc_session::Session;
 use rustc_span::symbol::{sym, Symbol};
 
 use std::num::IntErrorKind;
 
-pub fn update_limits(sess: &Session, krate: &ast::Crate) {
-    update_limit(sess, krate, &sess.recursion_limit, sym::recursion_limit, 128);
-    update_limit(sess, krate, &sess.move_size_limit, sym::move_size_limit, 0);
-    update_limit(sess, krate, &sess.type_length_limit, sym::type_length_limit, 1048576);
-    update_limit(sess, krate, &sess.const_eval_limit, sym::const_eval_limit, 1_000_000);
+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);
 }
 
-fn update_limit(
-    sess: &Session,
-    krate: &ast::Crate,
-    limit: &OnceCell<impl From<usize> + std::fmt::Debug>,
-    name: Symbol,
-    default: usize,
-) {
-    for attr in &krate.attrs {
+pub fn get_recursion_limit(krate_attrs: &[Attribute], sess: &Session) -> Limit {
+    get_limit(krate_attrs, sess, sym::recursion_limit, 128)
+}
+
+fn get_limit(krate_attrs: &[Attribute], sess: &Session, name: Symbol, default: usize) -> Limit {
+    for attr in krate_attrs {
         if !sess.check_name(attr, name) {
             continue;
         }
 
         if let Some(s) = attr.value_str() {
             match s.as_str().parse() {
-                Ok(n) => {
-                    limit.set(From::from(n)).unwrap();
-                    return;
-                }
+                Ok(n) => return Limit::new(n),
                 Err(e) => {
                     let mut err =
                         sess.struct_span_err(attr.span, "`limit` must be a non-negative integer");
@@ -68,5 +67,5 @@ fn update_limit(
             }
         }
     }
-    limit.set(From::from(default)).unwrap();
+    return Limit::new(default);
 }

compiler/rustc_middle/src/middle/mod.rs

@@ -32,3 +32,7 @@ pub mod privacy;
 pub mod region;
 pub mod resolve_lifetime;
 pub mod stability;
+
+pub fn provide(providers: &mut crate::ty::query::Providers) {
+    limits::provide(providers);
+}

compiler/rustc_middle/src/query/mod.rs

@@ -1712,4 +1712,26 @@ rustc_queries! {
     query conservative_is_privately_uninhabited(key: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
         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" }
+    }
 }

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.sess.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));
         }
 

compiler/rustc_middle/src/ty/mod.rs

@@ -1987,6 +1987,7 @@ pub fn provide(providers: &mut ty::query::Providers) {
     util::provide(providers);
     print::provide(providers);
     super::util::bug::provide(providers);
+    super::middle::provide(providers);
     *providers = ty::query::Providers {
         trait_impls_of: trait_def::trait_impls_of_provider,
         type_uninhabited_from: inhabitedness::type_uninhabited_from,

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.sess.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)

compiler/rustc_middle/src/ty/query/mod.rs

@@ -49,6 +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_target::spec::PanicStrategy;
 
 use rustc_ast as ast;

compiler/rustc_middle/src/ty/util.rs

@@ -206,8 +206,9 @@ impl<'tcx> TyCtxt<'tcx> {
         mut ty: Ty<'tcx>,
         normalize: impl Fn(Ty<'tcx>) -> Ty<'tcx>,
     ) -> Ty<'tcx> {
+        let recursion_limit = self.recursion_limit(());
         for iteration in 0.. {
-            if !self.sess.recursion_limit().value_within_limit(iteration) {
+            if !recursion_limit.value_within_limit(iteration) {
                 return self.ty_error_with_message(
                     DUMMY_SP,
                     &format!("reached the recursion limit finding the struct tail for {}", ty),