From d4ea9fa3fb400e1c5748489a65859fdead3dd132 Mon Sep 17 00:00:00 2001
From: Denis Merigoux <denis.merigoux@gmail.com>
Date: Tue, 1 Jun 2021 14:10:14 +0200
Subject: [PATCH] Restore the num_def_ids_untracked public function giving the
 total number of exported symbols for each crate

Restored underlying num_def_ids_method

Update compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs

Changed name to fit with naming convention

Co-authored-by: bjorn3 <bjorn3@users.noreply.github.com>

Update compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs

Replace regular doc with Rustdoc comment

Co-authored-by: Joshua Nelson <jyn514@gmail.com>

Clarifies third-party use of num_def_ids_untracked
---
 compiler/rustc_metadata/src/rmeta/decoder.rs             | 4 ++++
 compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs | 7 +++++++
 2 files changed, 11 insertions(+)

diff --git a/compiler/rustc_metadata/src/rmeta/decoder.rs b/compiler/rustc_metadata/src/rmeta/decoder.rs
index 706f3f6d8542b..59fec58f0a1b3 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder.rs
@@ -1931,6 +1931,10 @@ impl CrateMetadata {
         self.root.hash
     }
 
+    fn num_def_ids(&self) -> usize {
+        self.root.tables.def_keys.size()
+    }
+
     fn local_def_id(&self, index: DefIndex) -> DefId {
         DefId { krate: self.cnum, index }
     }
diff --git a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
index 02d1cf9aec79f..c1e12bb7a49cb 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
@@ -454,6 +454,13 @@ impl CStore {
         self.get_crate_data(def_id.krate).module_expansion(def_id.index, sess)
     }
 
+    /// Only public-facing way to traverse all the definitions in a non-local crate.
+    /// Critically useful for this third-party project: <https://github.com/hacspec/hacspec>.
+    /// See <https://github.com/rust-lang/rust/pull/85889> for context.
+    pub fn num_def_ids_untracked(&self, cnum: CrateNum) -> usize {
+        self.get_crate_data(cnum).num_def_ids()
+    }
+
     pub fn item_attrs(&self, def_id: DefId, sess: &Session) -> Vec<ast::Attribute> {
         self.get_crate_data(def_id.krate).get_item_attrs(def_id.index, sess).collect()
     }