1 files changed, 11 insertions, 6 deletions
diff --git a/libbuild2/action.hxx b/libbuild2/action.hxx
index e149574..85012ba 100644
--- a/libbuild2/action.hxx
+++ b/libbuild2/action.hxx
@@ -45,16 +45,17 @@ namespace build2
   // inner rule. In particular, it should not replace or override the inner's
   // logic.
   //
-  // While most of the relevant target state is duplicated, certain things are
-  // shared among the inner/outer rules, such as the target data pad and the
-  // group state. In particular, it is assumed the group state is always
-  // determined by the inner rule (see resolve_members()).
+  // While most of the action-specific target state is duplicated (see
+  // target::opstate), certain things are shared among the inner/outer rules,
+  // such as the path, mtime, and group state. In particular, it is assumed
+  // the group state is always determined by the inner rule (see
+  // resolve_members()).
   //
   // Normally, an outer rule will be responsible for any additional, outer
   // operation-specific work. Sometimes, however, the inner rule needs to
   // customize its behavior. In this case the outer and inner rules must
-  // communicate this explicitly (normally via the target's data pad) and
-  // there is a number of restrictions to this approach. See
+  // communicate this explicitly (normally via the target's auxiliary data
+  // storage) and there is a number of restrictions to this approach. See
   // cc::{link,install}_rule for details.
   //
   struct action
@@ -150,6 +151,7 @@ namespace build2
   // Id constants for build-in and pre-defined meta/operations.
   //
   // Note: currently max 15 (see above).
+  // Note: update small_vector in meta_operations if adding more.
   //
   const meta_operation_id noop_id      = 1; // nomop?
   const meta_operation_id perform_id   = 2;
@@ -164,6 +166,7 @@ namespace build2
   // something here remember to update the man page.
   //
   // Note: currently max 15 (see above).
+  // Note: update small_vector in operations if adding more.
   //
   const operation_id default_id            = 1; // Shall be first.
   const operation_id update_id             = 2; // Shall be second.
@@ -176,6 +179,8 @@ namespace build2
   const operation_id uninstall_id          = 7;
   const operation_id update_for_install_id = 8; // update(for install) alias.
 
+  // Commonly-used action ids.
+  //
   const action_id perform_update_id     = (perform_id << 4) | update_id;
   const action_id perform_clean_id      = (perform_id << 4) | clean_id;
   const action_id perform_test_id       = (perform_id << 4) | test_id;