1 files changed, 17 insertions, 4 deletions

diff --git a/crates/hir_ty/src/traits.rs b/crates/hir_ty/src/traits.rs
index 255323717..14cd3a2b4 100644
--- a/crates/hir_ty/src/traits.rs
+++ b/crates/hir_ty/src/traits.rs
@@ -3,7 +3,7 @@ use std::sync::Arc;
 
 use base_db::CrateId;
 use chalk_ir::cast::Cast;
-use chalk_solve::Solver;
+use chalk_solve::{logging_db::LoggingRustIrDatabase, Solver};
 use hir_def::{lang_item::LangItemTarget, TraitId};
 
 use crate::{db::HirDatabase, DebruijnIndex, Substs};
@@ -166,16 +166,25 @@ fn solve(
         }
         remaining > 0
     };
+
     let mut solve = || {
-        let solution = solver.solve_limited(&context, goal, should_continue);
-        log::debug!("solve({:?}) => {:?}", goal, solution);
-        solution
+        if is_chalk_print() {
+            let logging_db = LoggingRustIrDatabase::new(context);
+            let solution = solver.solve_limited(&logging_db, goal, &should_continue);
+            log::debug!("chalk program:\n{}", logging_db);
+            solution
+        } else {
+            solver.solve_limited(&context, goal, &should_continue)
+        }
     };
+
     // don't set the TLS for Chalk unless Chalk debugging is active, to make
     // extra sure we only use it for debugging
     let solution =
         if is_chalk_debug() { chalk::tls::set_current_program(db, solve) } else { solve() };
 
+    log::debug!("solve({:?}) => {:?}", goal, solution);
+
     solution
 }
 
@@ -183,6 +192,10 @@ fn is_chalk_debug() -> bool {
     std::env::var("CHALK_DEBUG").is_ok()
 }
 
+fn is_chalk_print() -> bool {
+    std::env::var("CHALK_PRINT").is_ok()
+}
+
 fn solution_from_chalk(
     db: &dyn HirDatabase,
     solution: chalk_solve::Solution<Interner>,