Trying to implement a "borrowck" pass

By overriding the `mir_borrowck` query

Author: smoelius

compiler/rustc_borrowck/src/consumers.rs

@@ -10,7 +10,7 @@ use rustc_middle::traits::DefiningAnchor;
 use rustc_middle::ty::TyCtxt;
 use std::rc::Rc;
 
-use crate::borrow_set::BorrowSet;
+use crate::{borrow_set::BorrowSet, BorrowCheckResult};
 
 pub use super::{
     constraints::OutlivesConstraint,
@@ -107,9 +107,18 @@ pub fn get_body_with_borrowck_facts(
     def: LocalDefId,
     options: ConsumerOptions,
 ) -> BodyWithBorrowckFacts<'_> {
+    *do_mir_borrowck(tcx, def, options).1.unwrap()
+}
+
+/// Like [`get_body_with_borrowck_facts`], but also return the borrow check results.
+pub fn do_mir_borrowck<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    def: LocalDefId,
+    options: ConsumerOptions,
+) -> (BorrowCheckResult<'tcx>, Option<Box<BodyWithBorrowckFacts<'tcx>>>) {
     let (input_body, promoted) = tcx.mir_promoted(def);
     let infcx = tcx.infer_ctxt().with_opaque_type_inference(DefiningAnchor::Bind(def)).build();
     let input_body: &Body<'_> = &input_body.borrow();
     let promoted: &IndexSlice<_, _> = &promoted.borrow();
-    *super::do_mir_borrowck(&infcx, input_body, promoted, Some(options)).1.unwrap()
+    super::do_mir_borrowck(&infcx, input_body, promoted, Some(options))
 }

compiler/rustc_borrowck/src/region_infer/mod.rs

@@ -1366,7 +1366,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
 
     // Evaluate whether `sup_region: sub_region`.
     #[instrument(skip(self), level = "debug", ret)]
-    fn eval_outlives(&self, sup_region: RegionVid, sub_region: RegionVid) -> bool {
+    pub fn eval_outlives(&self, sup_region: RegionVid, sub_region: RegionVid) -> bool {
         debug!(
             "sup_region's value = {:?} universal={:?}",
             self.region_value_str(sup_region),

compiler/rustc_lint/src/context.rs

@@ -190,19 +190,19 @@ impl LintStore {
     pub fn register_late_pass(
         &mut self,
         pass: impl for<'tcx> Fn(TyCtxt<'tcx>) -> LateLintPassObject<'tcx>
-        + 'static
-        + sync::DynSend
-        + sync::DynSync,
+            + 'static
+            + sync::DynSend
+            + sync::DynSync,
     ) {
         self.late_passes.push(Box::new(pass));
     }
 
     pub fn register_late_mod_pass(
         &mut self,
         pass: impl for<'tcx> Fn(TyCtxt<'tcx>) -> LateLintPassObject<'tcx>
-        + 'static
-        + sync::DynSend
-        + sync::DynSync,
+            + 'static
+            + sync::DynSend
+            + sync::DynSync,
     ) {
         self.late_module_passes.push(Box::new(pass));
     }
@@ -533,6 +533,7 @@ impl LintStore {
 }
 
 /// Context for lint checking outside of type inference.
+#[derive(Clone)]
 pub struct LateContext<'tcx> {
     /// Type context we're checking in.
     pub tcx: TyCtxt<'tcx>,
@@ -1145,6 +1146,20 @@ impl LintContext for EarlyContext<'_> {
 }
 
 impl<'tcx> LateContext<'tcx> {
+    pub fn new(tcx: TyCtxt<'tcx>, enclosing_body: Option<hir::BodyId>) -> Self {
+        Self {
+            tcx,
+            enclosing_body,
+            cached_typeck_results: Cell::new(None),
+            param_env: ty::ParamEnv::empty(),
+            effective_visibilities: &tcx.effective_visibilities(()),
+            lint_store: crate::unerased_lint_store(tcx),
+            last_node_with_lint_attrs: hir::CRATE_HIR_ID,
+            generics: None,
+            only_module: false,
+        }
+    }
+
     /// Gets the type-checking results for the current body,
     /// or `None` if outside a body.
     pub fn maybe_typeck_results(&self) -> Option<&'tcx ty::TypeckResults<'tcx>> {

compiler/rustc_lint/src/late.rs

@@ -43,8 +43,8 @@ macro_rules! lint_callback { ($cx:expr, $f:ident, $($args:expr),*) => ({
 /// Implements the AST traversal for late lint passes. `T` provides the
 /// `check_*` methods.
 pub struct LateContextAndPass<'tcx, T: LateLintPass<'tcx>> {
-    context: LateContext<'tcx>,
-    pass: T,
+    pub context: LateContext<'tcx>,
+    pub pass: T,
 }
 
 impl<'tcx, T: LateLintPass<'tcx>> LateContextAndPass<'tcx, T> {

compiler/rustc_lint/src/lib.rs

@@ -126,7 +126,7 @@ pub use builtin::SoftLints;
 pub use context::{CheckLintNameResult, FindLintError, LintStore};
 pub use context::{EarlyContext, LateContext, LintContext};
 pub use early::{check_ast_node, EarlyCheckNode};
-pub use late::{check_crate, unerased_lint_store};
+pub use late::{check_crate, unerased_lint_store, LateContextAndPass};
 pub use passes::{EarlyLintPass, LateLintPass};
 pub use rustc_session::lint::Level::{self, *};
 pub use rustc_session::lint::{BufferedEarlyLint, FutureIncompatibleInfo, Lint, LintId};