* lisp.h (toplevel): Add compile-time assert to verify suitable member layout

in Lisp_Sub_Char_Table.

2 files changed, 7 insertions, 1 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 05916477140..bb514753bdb 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -6,6 +6,8 @@
         (enum char_table_specials): Rename from CHAR_TABLE_STANDARD_SLOTS.
         Add SUB_CHAR_TABLE_OFFSET member.
         (make_uninit_sub_char_table): New function.
+        (toplevel): Add compile-time assert to verify suitable member layout
+        in Lisp_Sub_Char_Table.
         * alloc.c (mark_char_table): Add extra argument to denote char table
         subtype.  Adjust to match new layout of sub char-table.
         (mark_object): Always mark sub char-tables with mark_char_table.
diff --git a/src/lisp.h b/src/lisp.h
index 3c4845ec79b..6af390604d6 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -1561,7 +1561,11 @@ CHAR_TABLE_EXTRA_SLOTS (struct Lisp_Char_Table *ct)
           - CHAR_TABLE_STANDARD_SLOTS);
 }
 
-
+/* Make sure that sub char-table contents slot
+   is aligned on a multiple of Lisp_Objects.  */
+verify ((offsetof (struct Lisp_Sub_Char_Table, contents)
+         - offsetof (struct Lisp_Sub_Char_Table, depth)) % word_size == 0);
+
 /***********************************************************************
                                Symbols
  ***********************************************************************/