Simplify mark_object for pseudovectors

Suggested by Pip Cet (Bug#32405#14).
* src/alloc.c (mark_object): Remove unnecessary special cases for
PVEC_MARKER, PVEC_BOOL_VECTOR, PVEC_MISC_PTR, PVEC_USER_PTR, and
PVEC_FINALIZER.

change is to free up an enum Lisp_Type tag value, a scarce

2 files changed, 5 insertions, 19 deletions

diff --git a/src/alloc.c b/src/alloc.c
index fea0cec383b..337668f9c31 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -6495,28 +6495,10 @@ mark_object (Lisp_Object arg)
             mark_char_table (ptr, (enum pvec_type) pvectype);
             break;
 
-          case PVEC_MARKER:
-            /* DO NOT mark thru the marker's chain.
-               The buffer's markers chain does not preserve markers from gc;
-               instead, markers are removed from the chain when freed by gc.  */
-          case PVEC_BOOL_VECTOR:
-          case PVEC_MISC_PTR:
-#ifdef HAVE_MODULES
-          case PVEC_USER_PTR:
-#endif
-            /* No Lisp_Objects to mark in these.  */
-            VECTOR_MARK (ptr);
-            break;
-
           case PVEC_OVERLAY:
             mark_overlay (XOVERLAY (obj));
             break;
 
-          case PVEC_FINALIZER:
-            VECTOR_MARK (ptr);
-            mark_object (XFINALIZER (obj)->function);
-            break;
-
           case PVEC_SUBR:
             break;
 
@@ -6524,6 +6506,8 @@ mark_object (Lisp_Object arg)
             emacs_abort ();
 
           default:
+            /* A regular vector, or a pseudovector needing no special
+               treatment.  */
             mark_vectorlike (ptr);
           }
       }
diff --git a/src/lisp.h b/src/lisp.h
index c080cc6b146..dcc157e0b96 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -2264,7 +2264,9 @@ struct Lisp_Marker
      does not point anywhere.  */
 
   /* For markers that point somewhere,
-     this is used to chain of all the markers in a given buffer.  */
+     this is used to chain of all the markers in a given buffer.
+     The chain does not preserve markers from garbage collection;
+     instead, markers are removed from the chain when freed by GC.  */
   /* We could remove it and use an array in buffer_text instead.
      That would also allow us to preserve it ordered.  */
   struct Lisp_Marker *next;