2 files changed, 35 insertions, 30 deletions
diff --git a/compiler/rustc_trait_selection/src/solve/eval_ctxt.rs b/compiler/rustc_trait_selection/src/solve/eval_ctxt.rs
index b2e464bd7fb..5d1083090e3 100644
--- a/compiler/rustc_trait_selection/src/solve/eval_ctxt.rs
+++ b/compiler/rustc_trait_selection/src/solve/eval_ctxt.rs
@@ -180,34 +180,6 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
         let mode = if infcx.intercrate { SolverMode::Coherence } else { SolverMode::Normal };
         let mut search_graph = search_graph::SearchGraph::new(infcx.tcx, mode);
 
-        let inspect = {
-            let generate_proof_tree = match (
-                infcx.tcx.sess.opts.unstable_opts.dump_solver_proof_tree,
-                infcx.tcx.sess.opts.unstable_opts.dump_solver_proof_tree_use_cache,
-                generate_proof_tree,
-            ) {
-                (_, Some(use_cache), GenerateProofTree::Yes(_)) => {
-                    GenerateProofTree::Yes(DisableGlobalCache::from_bool(!use_cache))
-                }
-
-                (SolverProofTreeCondition::Always, use_cache, GenerateProofTree::No) => {
-                    let use_cache = use_cache.unwrap_or(true);
-                    GenerateProofTree::Yes(DisableGlobalCache::from_bool(!use_cache))
-                }
-
-                (_, None, GenerateProofTree::Yes(_)) => generate_proof_tree,
-                (SolverProofTreeCondition::OnRequest, _, _) => generate_proof_tree,
-                (SolverProofTreeCondition::OnError, _, _) => generate_proof_tree,
-            };
-
-            match generate_proof_tree {
-                GenerateProofTree::No => ProofTreeBuilder::new_noop(),
-                GenerateProofTree::Yes(global_cache_disabled) => {
-                    ProofTreeBuilder::new_root(global_cache_disabled)
-                }
-            }
-        };
-
         let mut ecx = EvalCtxt {
             search_graph: &mut search_graph,
             infcx: infcx,
@@ -221,7 +193,7 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
             var_values: CanonicalVarValues::dummy(),
             nested_goals: NestedGoals::new(),
             tainted: Ok(()),
-            inspect,
+            inspect: ProofTreeBuilder::new_maybe_root(infcx.tcx, generate_proof_tree),
         };
         let result = f(&mut ecx);
 
diff --git a/compiler/rustc_trait_selection/src/solve/inspect.rs b/compiler/rustc_trait_selection/src/solve/inspect.rs
index 1872c0c92d8..2061c3feb82 100644
--- a/compiler/rustc_trait_selection/src/solve/inspect.rs
+++ b/compiler/rustc_trait_selection/src/solve/inspect.rs
@@ -3,9 +3,11 @@ use rustc_middle::traits::solve::inspect::{self, CacheHit, CandidateKind};
 use rustc_middle::traits::solve::{
     CanonicalInput, Certainty, Goal, IsNormalizesToHack, QueryInput, QueryResult,
 };
-use rustc_middle::ty;
+use rustc_middle::ty::{self, TyCtxt};
+use rustc_session::config::SolverProofTreeCondition;
 
 use super::eval_ctxt::DisableGlobalCache;
+use super::GenerateProofTree;
 
 #[derive(Eq, PartialEq, Debug, Hash, HashStable)]
 pub struct WipGoalEvaluation<'tcx> {
@@ -173,6 +175,37 @@ impl<'tcx> ProofTreeBuilder<'tcx> {
         self.disable_global_cache
     }
 
+    pub fn new_maybe_root(
+        tcx: TyCtxt<'tcx>,
+        generate_proof_tree: GenerateProofTree,
+    ) -> ProofTreeBuilder<'tcx> {
+        let generate_proof_tree = match (
+            tcx.sess.opts.unstable_opts.dump_solver_proof_tree,
+            tcx.sess.opts.unstable_opts.dump_solver_proof_tree_use_cache,
+            generate_proof_tree,
+        ) {
+            (_, Some(use_cache), GenerateProofTree::Yes(_)) => {
+                GenerateProofTree::Yes(DisableGlobalCache::from_bool(!use_cache))
+            }
+
+            (SolverProofTreeCondition::Always, use_cache, GenerateProofTree::No) => {
+                let use_cache = use_cache.unwrap_or(true);
+                GenerateProofTree::Yes(DisableGlobalCache::from_bool(!use_cache))
+            }
+
+            (_, None, GenerateProofTree::Yes(_)) => generate_proof_tree,
+            (SolverProofTreeCondition::OnRequest, _, _) => generate_proof_tree,
+            (SolverProofTreeCondition::OnError, _, _) => generate_proof_tree,
+        };
+
+        match generate_proof_tree {
+            GenerateProofTree::No => ProofTreeBuilder::new_noop(),
+            GenerateProofTree::Yes(global_cache_disabled) => {
+                ProofTreeBuilder::new_root(global_cache_disabled)
+            }
+        }
+    }
+
     pub fn new_root(disable_global_cache: DisableGlobalCache) -> ProofTreeBuilder<'tcx> {
         ProofTreeBuilder::new(DebugSolver::Root, disable_global_cache)
     }