Implement Chalk's debug methods using TLS

crates/ra_hir_ty/Cargo.toml

@@ -24,6 +24,8 @@ ra_prof = { path = "../ra_prof" }
 ra_syntax = { path = "../ra_syntax" }
 test_utils = { path = "../test_utils" }
 
+scoped-tls = "1"
+
 chalk-solve =   { git = "https://github.com/rust-lang/chalk.git", rev = "039fc904a05f8cb3d0c682c9a57a63dda7a35356" }
 chalk-rust-ir = { git = "https://github.com/rust-lang/chalk.git", rev = "039fc904a05f8cb3d0c682c9a57a63dda7a35356" }
 chalk-ir =      { git = "https://github.com/rust-lang/chalk.git", rev = "039fc904a05f8cb3d0c682c9a57a63dda7a35356" }

crates/ra_hir_ty/src/display.rs

@@ -247,19 +247,21 @@ impl HirDisplay for ApplicationTy {
                 }
             }
             TypeCtor::Closure { .. } => {
-                let sig = self.parameters[0]
-                    .callable_sig(f.db)
-                    .expect("first closure parameter should contain signature");
-                if sig.params().is_empty() {
-                    write!(f, "||")?;
-                } else if f.omit_verbose_types() {
-                    write!(f, "|{}|", TYPE_HINT_TRUNCATION)?;
+                let sig = self.parameters[0].callable_sig(f.db);
+                if let Some(sig) = sig {
+                    if sig.params().is_empty() {
+                        write!(f, "||")?;
+                    } else if f.omit_verbose_types() {
+                        write!(f, "|{}|", TYPE_HINT_TRUNCATION)?;
+                    } else {
+                        write!(f, "|")?;
+                        f.write_joined(sig.params(), ", ")?;
+                        write!(f, "|")?;
+                    };
+                    write!(f, " -> {}", sig.ret().display(f.db))?;
                 } else {
-                    write!(f, "|")?;
-                    f.write_joined(sig.params(), ", ")?;
-                    write!(f, "|")?;
-                };
-                write!(f, " -> {}", sig.ret().display(f.db))?;
+                    write!(f, "{{closure}}")?;
+                }
             }
         }
         Ok(())

crates/ra_hir_ty/src/traits.rs

@@ -177,20 +177,29 @@ fn solve(
 
     let fuel = std::cell::Cell::new(CHALK_SOLVER_FUEL);
 
-    let solution = solver.solve_limited(&context, goal, || {
+    let should_continue = || {
         context.db.check_canceled();
         let remaining = fuel.get();
         fuel.set(remaining - 1);
         if remaining == 0 {
             log::debug!("fuel exhausted");
         }
         remaining > 0
-    });
+    };
+    let mut solve = || 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
 }
 
+fn is_chalk_debug() -> bool {
+    std::env::var("CHALK_DEBUG").is_ok()
+}
+
 fn solution_from_chalk(
     db: &dyn HirDatabase,
     solution: chalk_solve::Solution<Interner>,

crates/ra_hir_ty/src/traits/chalk.rs

@@ -20,6 +20,8 @@ use crate::{
     ProjectionTy, Substs, TraitRef, Ty, TypeCtor,
 };
 
+pub(super) mod tls;
+
 #[derive(Debug, Copy, Clone, Hash, PartialOrd, Ord, PartialEq, Eq)]
 pub struct Interner;
 
@@ -33,90 +35,85 @@ impl chalk_ir::interner::Interner for Interner {
     type Identifier = TypeAliasId;
     type DefId = InternId;
 
-    // FIXME: implement these
     fn debug_struct_id(
-        _type_kind_id: chalk_ir::StructId<Self>,
-        _fmt: &mut fmt::Formatter<'_>,
+        type_kind_id: StructId,
+        fmt: &mut fmt::Formatter<'_>,
     ) -> Option<fmt::Result> {
-        None
+        tls::with_current_program(|prog| Some(prog?.debug_struct_id(type_kind_id, fmt)))
     }
 
-    fn debug_trait_id(
-        _type_kind_id: chalk_ir::TraitId<Self>,
-        _fmt: &mut fmt::Formatter<'_>,
-    ) -> Option<fmt::Result> {
-        None
+    fn debug_trait_id(type_kind_id: TraitId, fmt: &mut fmt::Formatter<'_>) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_trait_id(type_kind_id, fmt)))
     }
 
-    fn debug_assoc_type_id(
-        _id: chalk_ir::AssocTypeId<Self>,
-        _fmt: &mut fmt::Formatter<'_>,
-    ) -> Option<fmt::Result> {
-        None
+    fn debug_assoc_type_id(id: AssocTypeId, fmt: &mut fmt::Formatter<'_>) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_assoc_type_id(id, fmt)))
     }
 
     fn debug_alias(
-        _projection: &chalk_ir::AliasTy<Self>,
-        _fmt: &mut fmt::Formatter<'_>,
+        alias: &chalk_ir::AliasTy<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
     ) -> Option<fmt::Result> {
-        None
+        tls::with_current_program(|prog| Some(prog?.debug_alias(alias, fmt)))
     }
 
-    fn debug_ty(_ty: &chalk_ir::Ty<Self>, _fmt: &mut fmt::Formatter<'_>) -> Option<fmt::Result> {
-        None
+    fn debug_ty(ty: &chalk_ir::Ty<Interner>, fmt: &mut fmt::Formatter<'_>) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_ty(ty, fmt)))
     }
 
     fn debug_lifetime(
-        _lifetime: &chalk_ir::Lifetime<Self>,
-        _fmt: &mut fmt::Formatter<'_>,
+        lifetime: &chalk_ir::Lifetime<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
     ) -> Option<fmt::Result> {
-        None
+        tls::with_current_program(|prog| Some(prog?.debug_lifetime(lifetime, fmt)))
     }
 
     fn debug_parameter(
-        _parameter: &Parameter<Self>,
-        _fmt: &mut fmt::Formatter<'_>,
+        parameter: &Parameter<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
     ) -> Option<fmt::Result> {
-        None
+        tls::with_current_program(|prog| Some(prog?.debug_parameter(parameter, fmt)))
     }
 
-    fn debug_goal(_goal: &Goal<Self>, _fmt: &mut fmt::Formatter<'_>) -> Option<fmt::Result> {
-        None
+    fn debug_goal(goal: &Goal<Interner>, fmt: &mut fmt::Formatter<'_>) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_goal(goal, fmt)))
     }
 
     fn debug_goals(
-        _goals: &chalk_ir::Goals<Self>,
-        _fmt: &mut fmt::Formatter<'_>,
+        goals: &chalk_ir::Goals<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
     ) -> Option<fmt::Result> {
-        None
+        tls::with_current_program(|prog| Some(prog?.debug_goals(goals, fmt)))
     }
 
     fn debug_program_clause_implication(
-        _pci: &chalk_ir::ProgramClauseImplication<Self>,
-        _fmt: &mut fmt::Formatter<'_>,
+        pci: &chalk_ir::ProgramClauseImplication<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
     ) -> Option<fmt::Result> {
-        None
+        tls::with_current_program(|prog| Some(prog?.debug_program_clause_implication(pci, fmt)))
     }
 
     fn debug_application_ty(
-        _application_ty: &chalk_ir::ApplicationTy<Self>,
-        _fmt: &mut fmt::Formatter<'_>,
+        application_ty: &chalk_ir::ApplicationTy<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
     ) -> Option<fmt::Result> {
-        None
+        tls::with_current_program(|prog| Some(prog?.debug_application_ty(application_ty, fmt)))
     }
 
     fn debug_substitution(
-        _substitution: &chalk_ir::Substitution<Self>,
-        _fmt: &mut fmt::Formatter<'_>,
+        substitution: &chalk_ir::Substitution<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
     ) -> Option<fmt::Result> {
-        None
+        tls::with_current_program(|prog| Some(prog?.debug_substitution(substitution, fmt)))
     }
 
     fn debug_separator_trait_ref(
-        _separator_trait_ref: &chalk_ir::SeparatorTraitRef<Self>,
-        _fmt: &mut fmt::Formatter<'_>,
+        separator_trait_ref: &chalk_ir::SeparatorTraitRef<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
     ) -> Option<fmt::Result> {
-        None
+        tls::with_current_program(|prog| {
+            Some(prog?.debug_separator_trait_ref(separator_trait_ref, fmt))
+        })
     }
 
     fn intern_ty(&self, ty: chalk_ir::TyData<Self>) -> Box<chalk_ir::TyData<Self>> {