Add environment variable tracking in places where it was convenient

compiler/rustc_borrowck/src/nll.rs

@@ -22,6 +22,7 @@ use rustc_mir_dataflow::move_paths::MoveData;
 use rustc_mir_dataflow::points::DenseLocationMap;
 use rustc_session::config::MirIncludeSpans;
 use rustc_span::symbol::sym;
+use rustc_span::Symbol;
 use tracing::{debug, instrument};
 
 use crate::borrow_set::BorrowSet;
@@ -179,9 +180,11 @@ pub(crate) fn compute_regions<'a, 'tcx>(
         }
 
         if polonius_output {
-            let algorithm =
-                env::var("POLONIUS_ALGORITHM").unwrap_or_else(|_| String::from("Hybrid"));
-            let algorithm = Algorithm::from_str(&algorithm).unwrap();
+            let algorithm = infcx
+                .tcx
+                .env_var(Symbol::intern("POLONIUS_ALGORITHM"))
+                .unwrap_or_else(|| Symbol::intern("Hybrid"));
+            let algorithm = Algorithm::from_str(algorithm.as_str()).unwrap();
             debug!("compute_regions: using polonius algorithm {:?}", algorithm);
             let _prof_timer = infcx.tcx.prof.generic_activity("polonius_analysis");
             Some(Rc::new(Output::compute(all_facts, algorithm, false)))

compiler/rustc_lint/src/non_local_def.rs

@@ -105,8 +105,10 @@ impl<'tcx> LateLintPass<'tcx> for NonLocalDefinitions {
         // determining if we are in a doctest context can't currently be determined
         // by the code itself (there are no specific attributes), but fortunately rustdoc
         // sets a perma-unstable env var for libtest so we just reuse that for now
-        let is_at_toplevel_doctest =
-            || self.body_depth == 2 && std::env::var("UNSTABLE_RUSTDOC_TEST_PATH").is_ok();
+        let is_at_toplevel_doctest = || {
+            self.body_depth == 2
+                && cx.tcx.env_var(Symbol::intern("UNSTABLE_RUSTDOC_TEST_PATH")).is_some()
+        };
 
         match item.kind {
             ItemKind::Impl(impl_) => {