(gc_sweep): Add comment.

diff --git a/src/alloc.c b/src/alloc.c
index 83007657e20d14e60474de0a0c24a68ed3f04c72..eba9d867c8c53cdbdc247d3bc3d459079a7ea70f 100644 (file)
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -4774,6 +4774,9 @@ gc_sweep ()
 
        for (; sym < end; ++sym)
          {
+           /* Check if the symbol was created during loadup.  In such a case
+              it might be pointed to by pure bytecode which we don't trace,
+              so we conservatively assume that it is live.  */
            int pure_p = PURE_POINTER_P (sym->name);
            
            if (!XMARKBIT (sym->plist) && !pure_p)