Make closure_saved_names_of_captured_variables a query.

4 files changed, 22 insertions, 32 deletions

diff --git a/compiler/rustc_middle/src/arena.rs b/compiler/rustc_middle/src/arena.rs
index 6c404fbb7c6..ac4cef34fdd 100644
--- a/compiler/rustc_middle/src/arena.rs
+++ b/compiler/rustc_middle/src/arena.rs
@@ -27,6 +27,11 @@ macro_rules! arena_types {
                     rustc_middle::mir::Promoted,
                     rustc_middle::mir::Body<'tcx>
                 >,
+            [decode] closure_debuginfo:
+                rustc_index::IndexVec<
+                    rustc_target::abi::FieldIdx,
+                    rustc_span::symbol::Symbol,
+                >,
             [decode] typeck_results: rustc_middle::ty::TypeckResults<'tcx>,
             [decode] borrowck_result:
                 rustc_middle::mir::BorrowCheckResult<'tcx>,
diff --git a/compiler/rustc_middle/src/query/erase.rs b/compiler/rustc_middle/src/query/erase.rs
index fd02a16130f..7d962b92caa 100644
--- a/compiler/rustc_middle/src/query/erase.rs
+++ b/compiler/rustc_middle/src/query/erase.rs
@@ -55,6 +55,10 @@ impl<T> EraseType for &'_ ty::List<T> {
     type Result = [u8; size_of::<*const ()>()];
 }
 
+impl<I: rustc_index::Idx, T> EraseType for &'_ rustc_index::IndexSlice<I, T> {
+    type Result = [u8; size_of::<&'static rustc_index::IndexSlice<u32, ()>>()];
+}
+
 impl<T> EraseType for Result<&'_ T, traits::query::NoSolution> {
     type Result = [u8; size_of::<Result<&'static (), traits::query::NoSolution>>()];
 }
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 132b11b29eb..ee8f3201ddd 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -531,6 +531,19 @@ rustc_queries! {
         }
     }
 
+    /// Returns names of captured upvars for closures and generators.
+    ///
+    /// Here are some examples:
+    ///  - `name__field1__field2` when the upvar is captured by value.
+    ///  - `_ref__name__field` when the upvar is captured by reference.
+    ///
+    /// For generators this only contains upvars that are shared by all states.
+    query closure_saved_names_of_captured_variables(def_id: DefId) -> &'tcx IndexVec<abi::FieldIdx, Symbol> {
+        arena_cache
+        desc { |tcx| "computing debuginfo for closure `{}`", tcx.def_path_str(def_id) }
+        separate_provide_extern
+    }
+
     query mir_generator_witnesses(key: DefId) -> &'tcx Option<mir::GeneratorLayout<'tcx>> {
         arena_cache
         desc { |tcx| "generator witness types for `{}`", tcx.def_path_str(key) }
diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs
index c9f69c37782..2e841e261fc 100644
--- a/compiler/rustc_middle/src/ty/util.rs
+++ b/compiler/rustc_middle/src/ty/util.rs
@@ -738,38 +738,6 @@ impl<'tcx> TyCtxt<'tcx> {
         if visitor.found_recursion { Err(expanded_type) } else { Ok(expanded_type) }
     }
 
-    /// Returns names of captured upvars for closures and generators.
-    ///
-    /// Here are some examples:
-    ///  - `name__field1__field2` when the upvar is captured by value.
-    ///  - `_ref__name__field` when the upvar is captured by reference.
-    ///
-    /// For generators this only contains upvars that are shared by all states.
-    pub fn closure_saved_names_of_captured_variables(
-        self,
-        def_id: DefId,
-    ) -> SmallVec<[String; 16]> {
-        let body = self.optimized_mir(def_id);
-
-        body.var_debug_info
-            .iter()
-            .filter_map(|var| {
-                let is_ref = match var.value {
-                    mir::VarDebugInfoContents::Place(place)
-                        if place.local == mir::Local::new(1) =>
-                    {
-                        // The projection is either `[.., Field, Deref]` or `[.., Field]`. It
-                        // implies whether the variable is captured by value or by reference.
-                        matches!(place.projection.last().unwrap(), mir::ProjectionElem::Deref)
-                    }
-                    _ => return None,
-                };
-                let prefix = if is_ref { "_ref__" } else { "" };
-                Some(prefix.to_owned() + var.name.as_str())
-            })
-            .collect()
-    }
-
     // FIXME(eddyb) maybe precompute this? Right now it's computed once
     // per generator monomorphization, but it doesn't depend on substs.
     pub fn generator_layout_and_saved_local_names(