fix(3p/nix): Fix all remaining compiler warnings r/1403

This compiles under `-Wall -Werror`.

The largest chunk of this change is `final` qualifiers for the various
Nix CLI command structs, which inherit from a Command class that has
more virtual functions than are implemented by each command.

Change-Id: I0925e6e1a39013f026773db5816e4a77d50f3b4a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1294
Tested-by: BuildkiteCI
Reviewed-by: isomer <isomer@tvl.fyi>
Reviewed-by: kanepyork <rikingcoding@gmail.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/third_party/nix/src/libstore/nar-info-disk-cache.cc b/third_party/nix/src/libstore/nar-info-disk-cache.cc
index c98882bff319..be2ad8f2dac1 100644
--- a/third_party/nix/src/libstore/nar-info-disk-cache.cc
+++ b/third_party/nix/src/libstore/nar-info-disk-cache.cc
@@ -49,7 +49,7 @@ create table if not exists LastPurge (
 
 )sql";
 
-class NarInfoDiskCacheImpl : public NarInfoDiskCache {
+class NarInfoDiskCacheImpl final : public NarInfoDiskCache {
  public:
   /* How often to purge expired entries from the cache. */
   const int purgeInterval = 24 * 3600;
@@ -280,8 +280,9 @@ class NarInfoDiskCacheImpl : public NarInfoDiskCache {
   }
 };
 
-ref<NarInfoDiskCache> getNarInfoDiskCache() {
-  static ref<NarInfoDiskCache> cache = make_ref<NarInfoDiskCacheImpl>();
+std::shared_ptr<NarInfoDiskCache> getNarInfoDiskCache() {
+  static std::shared_ptr<NarInfoDiskCache> cache =
+      std::make_shared<NarInfoDiskCacheImpl>();
   return cache;
 }