feat(noir sync): Calculate noir hash based on just noir-repo-ref and noir-repo.patch

noir/.rebuild_patterns

@@ -3,3 +3,5 @@
 ^noir/scripts/bootstrap_packages.sh
 ^noir/scripts/test_js_packages.sh
 ^noir/scripts/test_native.sh
+^noir/noir-repo-ref
+^noir/noir-repo.patch

noir/bootstrap.sh

@@ -31,19 +31,37 @@ function noir_sync {
 # Calculate the content hash for caching, taking into account that `noir-repo`
 # is not part of the `aztec-packages` repo itself, so the `git ls-tree` used
 # by `cache_content_hash` would not take those files into account.
+function noir_repo_content_hash {
+  echo $(REPO_PATH=./noir-repo AZTEC_CACHE_COMMIT=HEAD cache_content_hash $@)
+}
+
+# Get the cache content hash. It should only be based on files committed to `aztec-packages`
+# in order to be able to support using `AZTEC_CACHE_COMMIT` for historical queries.
 function noir_content_hash {
-  function noir_repo_content_hash {
-    echo $(REPO_PATH=./noir-repo cache_content_hash $@)
-  }
-  with_tests=${1:-0}
+  # Currently we don't make a distinction between test and non-test hash
+  tests=${1:-0}
+
+  # If there are changes in the noir-repo which aren't just due to the patch applied to it,
+  # then just disable the cache, unless the noir-repo is in an evolving feature branch.
   noir_hash=$(cache_content_hash .rebuild_patterns)
-  noir_repo_hash=$(noir_repo_content_hash .noir-repo.rebuild_patterns)
-  if [ "$with_tests" == "1" ]; then
-    noir_repo_hash_tests=$(noir_repo_content_hash .noir-repo.rebuild_patterns_tests)
+
+  if [ "${AZTEC_CACHE_COMMIT:-HEAD}" != "HEAD" ]; then
+    # Ignore the current content of noir-repo, it doesn't support history anyway.
+    echo $noir_hash
   else
-    noir_repo_hash_tests=""
+    cache_mode=$(scripts/sync.sh cache-mode)
+    case "$cache_mode" in
+      "noir")
+        echo $noir_hash
+        ;;
+      "noir-repo")
+        echo $(hash_str $noir_hash $(noir_repo_content_hash .noir-repo.rebuild_patterns .noir-repo.rebuild_patterns_tests))
+        ;;
+      *)
+        echo $cache_mode
+        ;;
+    esac
   fi
-  echo $(hash_str $noir_hash $noir_repo_hash $noir_repo_hash_tests)
 }
 
 # Builds nargo, acvm and profiler binaries.

noir/scripts/sync.sh

@@ -340,6 +340,26 @@ function make_patch {
   fi
 }
 
+# Decide what kind of caching we should do.
+function cache_mode {
+  if has_uncommitted_changes; then
+    # Same magic word as the ci3 scripts like `cache_content_hash` use.
+    echo "disabled-cache"
+  elif is_on_branch; then
+    # If we're on a branch (not a tag or a commit) then we can only cache
+    # based on the evolving content of the noir-repo itself.
+    echo "noir-repo"
+  elif is_last_commit_patch; then
+    # If we're on a detached head and the last commit is the patch,
+    # then we can use the noir-repo-ref and the patch file as cache key.
+    echo "noir"
+  else
+    # Otherwise we're on a tag and added some extra commits which are
+    # not part of a patch yet, so we can't use the cache.
+    echo "disabled-cache"
+  fi
+}
+
 # Show debug information
 function info {
   function pad {
@@ -368,6 +388,7 @@ function info {
   echo_info "Has fixup and patch" $(yesno has_fixup_and_patch)
   echo_info "Has uncommitted changes" $(yesno has_uncommitted_changes)
   echo_info "Latest nightly" $(latest_nightly)
+  echo_info "Cache mode" $(cache_mode)
 }
 
 cmd=${1:-}
@@ -386,6 +407,9 @@ case "$cmd" in
   "needs-patch")
     [ -d noir-repo ] && [ -d noir-repo/.git ] && needs_patch && exit 0 || exit 1
     ;;
+  "cache-mode")
+    echo $(cache_mode)
+    ;;
   "latest-nightly")
     echo $(latest_nightly)
     ;;