GlobalCtxt: Erase LintStore type.

Author: Centril

src/librustc/ty/context.rs

@@ -8,7 +8,7 @@ use crate::hir::map as hir_map;
 use crate::hir::map::DefPathHash;
 use crate::ich::{NodeIdHashingMode, StableHashingContext};
 use crate::infer::canonical::{Canonical, CanonicalVarInfo, CanonicalVarInfos};
-use crate::lint::{maybe_lint_level_root, struct_lint_level, LintSource, LintStore};
+use crate::lint::{maybe_lint_level_root, struct_lint_level, LintSource};
 use crate::middle;
 use crate::middle::cstore::CrateStoreDyn;
 use crate::middle::cstore::EncodedMetadata;
@@ -947,7 +947,11 @@ pub struct GlobalCtxt<'tcx> {
 
     pub sess: &'tcx Session,
 
-    pub lint_store: Lrc<LintStore>,
+    /// This only ever stores a `LintStore` but we don't want a dependency on that type here.
+    ///
+    /// FIXME(Centril): consider `dyn LintStoreMarker` once
+    /// we can upcast to `Any` for some additional type safety.
+    pub lint_store: Lrc<dyn Any>,
 
     pub dep_graph: DepGraph,
 
@@ -1116,7 +1120,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// reference to the context, to allow formatting values that need it.
     pub fn create_global_ctxt(
         s: &'tcx Session,
-        lint_store: Lrc<LintStore>,
+        lint_store: Lrc<dyn Any>,
         local_providers: ty::query::Providers<'tcx>,
         extern_providers: ty::query::Providers<'tcx>,
         arenas: &'tcx AllArenas,

src/librustc_lint/late.rs

@@ -15,8 +15,7 @@
 //! for all lint attributes.
 
 use rustc::hir::map::Map;
-use rustc::lint::LateContext;
-use rustc::lint::{LateLintPass, LateLintPassObject};
+use rustc::lint::{LateContext, LateLintPass, LateLintPassObject, LintStore};
 use rustc::ty::{self, TyCtxt};
 use rustc_data_structures::sync::{join, par_iter, ParallelIterator};
 use rustc_hir as hir;
@@ -31,6 +30,12 @@ use syntax::walk_list;
 use log::debug;
 use std::slice;
 
+/// Extract the `LintStore` from the query context.
+/// This function exists because we've erased `LintStore` as `dyn Any` in the context.
+crate fn unerased_lint_store<'tcx>(tcx: TyCtxt<'tcx>) -> &'tcx LintStore {
+    tcx.lint_store.downcast_ref().unwrap()
+}
+
 macro_rules! lint_callback { ($cx:expr, $f:ident, $($args:expr),*) => ({
     $cx.pass.$f(&$cx.context, $($args),*);
 }) }
@@ -356,7 +361,7 @@ fn late_lint_mod_pass<'tcx, T: for<'a> LateLintPass<'a, 'tcx>>(
         tables: &ty::TypeckTables::empty(None),
         param_env: ty::ParamEnv::empty(),
         access_levels,
-        lint_store: &tcx.lint_store,
+        lint_store: unerased_lint_store(tcx),
         last_node_with_lint_attrs: tcx.hir().as_local_hir_id(module_def_id).unwrap(),
         generics: None,
         only_module: true,
@@ -386,7 +391,7 @@ pub fn late_lint_mod<'tcx, T: for<'a> LateLintPass<'a, 'tcx>>(
     late_lint_mod_pass(tcx, module_def_id, builtin_lints);
 
     let mut passes: Vec<_> =
-        tcx.lint_store.late_module_passes.iter().map(|pass| (pass)()).collect();
+        unerased_lint_store(tcx).late_module_passes.iter().map(|pass| (pass)()).collect();
 
     if !passes.is_empty() {
         late_lint_mod_pass(tcx, module_def_id, LateLintPassObjects { lints: &mut passes[..] });
@@ -403,7 +408,7 @@ fn late_lint_pass_crate<'tcx, T: for<'a> LateLintPass<'a, 'tcx>>(tcx: TyCtxt<'tc
         tables: &ty::TypeckTables::empty(None),
         param_env: ty::ParamEnv::empty(),
         access_levels,
-        lint_store: &tcx.lint_store,
+        lint_store: unerased_lint_store(tcx),
         last_node_with_lint_attrs: hir::CRATE_HIR_ID,
         generics: None,
         only_module: false,
@@ -424,7 +429,7 @@ fn late_lint_pass_crate<'tcx, T: for<'a> LateLintPass<'a, 'tcx>>(tcx: TyCtxt<'tc
 }
 
 fn late_lint_crate<'tcx, T: for<'a> LateLintPass<'a, 'tcx>>(tcx: TyCtxt<'tcx>, builtin_lints: T) {
-    let mut passes = tcx.lint_store.late_passes.iter().map(|p| (p)()).collect::<Vec<_>>();
+    let mut passes = unerased_lint_store(tcx).late_passes.iter().map(|p| (p)()).collect::<Vec<_>>();
 
     if !tcx.sess.opts.debugging_opts.no_interleave_lints {
         if !passes.is_empty() {
@@ -443,7 +448,7 @@ fn late_lint_crate<'tcx, T: for<'a> LateLintPass<'a, 'tcx>>(tcx: TyCtxt<'tcx>, b
         }
 
         let mut passes: Vec<_> =
-            tcx.lint_store.late_module_passes.iter().map(|pass| (pass)()).collect();
+            unerased_lint_store(tcx).late_module_passes.iter().map(|pass| (pass)()).collect();
 
         for pass in &mut passes {
             tcx.sess

src/librustc_lint/levels.rs

@@ -1,3 +1,4 @@
+use super::late::unerased_lint_store;
 use rustc::hir::map::Map;
 use rustc::lint::{LintLevelMap, LintLevelSets, LintLevelsBuilder, LintStore};
 use rustc::ty::query::Providers;
@@ -11,11 +12,11 @@ pub use rustc_session::lint::{FutureIncompatibleInfo, Level, Lint, LintId};
 
 fn lint_levels(tcx: TyCtxt<'_>, cnum: CrateNum) -> &LintLevelMap {
     assert_eq!(cnum, LOCAL_CRATE);
-    let store = &tcx.lint_store;
+    let store = unerased_lint_store(tcx);
     let mut builder = LintLevelMapBuilder {
         levels: LintLevelSets::builder(tcx.sess, false, &store),
         tcx: tcx,
-        store: store,
+        store,
     };
     let krate = tcx.hir().krate();
 

src/librustc_lint/lib.rs

@@ -14,6 +14,7 @@
 #![feature(bool_to_option)]
 #![feature(box_patterns)]
 #![feature(box_syntax)]
+#![feature(crate_visibility_modifier)]
 #![feature(nll)]
 #![recursion_limit = "256"]