list used used_replacements after we figure out what is used

Author: Eh2406

src/cargo/core/resolver/context.rs

@@ -47,7 +47,6 @@ pub struct Context {
     // hash maps but are built up as "construction lists". We'll iterate these
     // at the very end and actually construct the map that we're making.
     pub resolve_graph: RcList<GraphNode>,
-    pub resolve_replacements: RcList<(PackageId, PackageId)>,
 }
 
 /// When backtracking it can be useful to know how far back to go.
@@ -104,7 +103,6 @@ impl Context {
                 None
             },
             parents: Graph::new(),
-            resolve_replacements: RcList::new(),
             activations: im_rc::HashMap::new(),
         }
     }
@@ -331,15 +329,14 @@ impl Context {
         Ok(ret)
     }
 
-    pub fn resolve_replacements(&self) -> HashMap<PackageId, PackageId> {
-        let mut replacements = HashMap::new();
-        let mut cur = &self.resolve_replacements;
-        while let Some(ref node) = cur.head {
-            let (k, v) = node.0;
-            replacements.insert(k, v);
-            cur = &node.1;
-        }
-        replacements
+    pub fn resolve_replacements(
+        &self,
+        registry: &RegistryQueryer<'_>,
+    ) -> HashMap<PackageId, PackageId> {
+        self.activations
+            .values()
+            .filter_map(|(s, _)| registry.used_replacement_for(s.package_id()))
+            .collect()
     }
 
     pub fn graph(&self) -> Graph<PackageId, Vec<Dependency>> {

src/cargo/core/resolver/mod.rs

@@ -143,7 +143,7 @@ pub fn resolve(
     }
     let resolve = Resolve::new(
         cx.graph(),
-        cx.resolve_replacements(),
+        cx.resolve_replacements(&registry),
         cx.resolve_features
             .iter()
             .map(|(k, v)| (*k, v.iter().map(|x| x.to_string()).collect()))
@@ -668,8 +668,6 @@ fn activate(
 
     let candidate = match candidate.replace {
         Some(replace) => {
-            cx.resolve_replacements
-                .push((candidate_pid, replace.package_id()));
             if cx.flag_activated(&replace, method)? && activated {
                 return Ok(None);
             }

src/cargo/core/resolver/types.rs

@@ -95,11 +95,12 @@ pub struct RegistryQueryer<'a> {
     pub registry: &'a mut (dyn Registry + 'a),
     replacements: &'a [(PackageIdSpec, Dependency)],
     try_to_use: &'a HashSet<PackageId>,
-    cache: HashMap<Dependency, Rc<Vec<Candidate>>>,
     // If set the list of dependency candidates will be sorted by minimal
     // versions first. That allows `cargo update -Z minimal-versions` which will
     // specify minimum dependency versions to be used.
     minimal_versions: bool,
+    cache: HashMap<Dependency, Rc<Vec<Candidate>>>,
+    used_replacements: HashMap<PackageId, PackageId>,
 }
 
 impl<'a> RegistryQueryer<'a> {
@@ -112,12 +113,17 @@ impl<'a> RegistryQueryer<'a> {
         RegistryQueryer {
             registry,
             replacements,
-            cache: HashMap::new(),
             try_to_use,
             minimal_versions,
+            cache: HashMap::new(),
+            used_replacements: HashMap::new(),
         }
     }
 
+    pub fn used_replacement_for(&self, p: PackageId) -> Option<(PackageId, PackageId)> {
+        self.used_replacements.get(&p).map(|&r| (p, r))
+    }
+
     /// Queries the `registry` to return a list of candidates for `dep`.
     ///
     /// This method is the location where overrides are taken into account. If
@@ -212,6 +218,10 @@ impl<'a> RegistryQueryer<'a> {
             for dep in summary.dependencies() {
                 debug!("\t{} => {}", dep.package_name(), dep.version_req());
             }
+            if let Some(r) = &replace {
+                self.used_replacements
+                    .insert(summary.package_id(), r.package_id());
+            }
 
             candidate.replace = replace;
         }