configure check for the type of the list (second) parameter of the Xa…

…wListChange function, and cast to it in the call; probably too simplistic

git-svn-id: svn://tug.org/texlive/trunk/Build/source@74082 c570f23f-e606-0410-a88d-b1316a301751

texk/xdvik/ChangeLog

@@ -1,3 +1,17 @@
+2025-02-17  Karl Berry  <karl@freefriends.org>
+
+	* m4/xdvi-check-xaw.m4: try to discern the type of the list
+	(second) parameter of the XawListChange function, (too) simply
+	with: sed -n 's/list,$//p' /usr/include/X11/Xaw/List.h.
+	Default to the type of the page_labels member, as before.
+	Maybe it will work in practice?
+	* gui/pagesel.c (XAWLISTCHANGELISTTYPE): define if not defined.
+	(xaw_update_list): cast to it.
+	(See next ChangeLog entry for links to discussions.)
+
+	* c-auto.in,
+	* configure: regenerate.
+
 2025-02-15  Karl Berry  <karl@freefriends.org>
 
 	* gui/pagesel.c (xaw_update_list): put in comment about the known

texk/xdvik/c-auto.in

@@ -484,6 +484,9 @@
 /* Define to use the Xaw toolkit. */
 #undef XAW
 
+/* type of XawListChange list parameter */
+#undef XAWLISTCHANGELISTTYPE
+
 /* Define to 1 if the X Window System is missing or not being used. */
 #undef X_DISPLAY_MISSING
 

texk/xdvik/configure

@@ -19947,6 +19947,55 @@ if test "x$xdvi_have_xaw" = xyes; then
 
 printf "%s\n" "#define XAW 1" >>confdefs.h
 
+
+  # We need the type of the "list" parameter to XawListChange
+  # (the second parameter), for use in gui/pagesel.c. See more comments there.
+  #
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for type of XawListChange list parameter" >&5
+printf %s "checking for type of XawListChange list parameter... " >&6; }
+  # Although we could try to use the compiler to discern the location of
+  # <X11/Xaw/List.h>, that seems likely to have its own problems. Let's
+  # try just assuming the standard location.
+  #
+  listh=/usr/include/X11/Xaw/List.h
+
+  # Clearly this simple search is subject to plenty of problems in
+  # theory, but in practice, if no one gratuitously changes the
+  # formatting in Xaw/List.h, it should be ok? The line intended to be
+  # matched looks like
+  #   String                      *list, [except with tabs]
+  # or
+  #   _Xconst char *list,
+  # or who knows what else. Hopefully it will be the complete type.
+  #
+  list_type=`sed -n 's/list,$//p' $listh`
+  #
+  # The type ordinarily has lots of whitespace, as in the String line above.
+  # People will uselessly complain about that, so reduce it to a single space:
+  tab='	' # that's a tab character
+  # The outer square brackets are the Autoconf quote pair;
+  # the inner square brackets are the normal regexp character class.
+  echo "got '$list_type' from $listh, tab=$tab." >/tmp/lh
+  list_type=`echo "$list_type" | sed "s/[ $tab][ $tab]*/ /g"`
+  echo "new '$list_type' from $listh" >>/tmp/lh
+  #
+  if test -z "$list_type"; then
+    # But if we didn't find anything, default to the type of our
+    # page_labels member in pagesel.c, which has been the traditional
+    # effective behavior.
+    list_type="char **"
+  fi
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $list_type" >&5
+printf "%s\n" "$list_type" >&6; }
+  #debug: echo "got '$list_type' from $listh" >/tmp/lh
+  #
+  # autoconf internally quotes the shell variable value with
+  # ac_define_unquoted; we don't use shell "quotes" here since the final
+  # value must not have any quotes, being a type that we want to use in
+  # a cast, not a string constant.
+
+printf "%s\n" "#define XAWLISTCHANGELISTTYPE $list_type" >>confdefs.h
+
 else
   as_fn_error $? "Sorry, you will need at least the Xaw header/library files to compile xdvik." "$LINENO" 5
 fi

texk/xdvik/gui/pagesel.c

@@ -539,18 +539,25 @@ xaw_update_list(void)
     /* delete and re-create list */
     ASSERT(total_pages <= (int)page_info.index_size, "");
 
-    /* The following line causes a gcc incompatible-pointer-types error
-       on some system, due to lack and/or presence of const in the
+    /* The purpose of the (XAWLISTCHANGELISTTYPE) cast for page_labels
+       is to avoid a gcc incompatible-pointer-types error
+       on some systems, due to the lack and/or presence of const in the
        XawListChange function parameter. Unfortunately different systems
        evidently have different, and incompatible, types for that
        parameter. Thus a cast to any single type will fail on some
-       systems. A configure test to determine the correct type for the
-       cast seems like the only robust solution? --karl, 15feb25.
-       xdvi bug report: https://sourceforge.net/p/xdvi/bugs/406/
-       discussion of alternatives:
-         https://tug.org/pipermail/tex-k/2024-February/004008.html
+       systems. A (too) simplistic configure test to determine the
+       correct type is done in xdvi-check-xaw.m4. See more comments there.
+         xdvi bug report:
+           https://sourceforge.net/p/xdvi/bugs/406/
+         discussion of alternatives:
+           https://tug.org/pipermail/tex-k/2024-February/004008.html
     */
-    XawListChange(LIST_WIDGET, page_info.page_labels, 0,
+#ifndef XAWLISTCHANGELISTTYPE
+#define XAWLISTCHANGELISTTYPE char **
+#endif
+    XawListChange(LIST_WIDGET, 
+                  (XAWLISTCHANGELISTTYPE) page_info.page_labels,
+                  0,
 		  MAX(button_width, pagelist_width), False);
     /* restore selected item */
     if (idx != XAW_LIST_NONE) {

texk/xdvik/m4/xdvi-check-xaw.m4

@@ -70,10 +70,56 @@ if test "x$xdvi_have_xaw" = xyes; then
              [$x_xp_lib $x_xmu_lib -lXt $X_PRE_LIBS $x_ext_lib $x_xpm_libs -lX11 $X_EXTRA_LIBS $XLFLAG])
        fi],
       [$x_xmu_lib -lXt $X_PRE_LIBS $x_ext_lib $x_xpm_libs -lX11 $X_EXTRA_LIBS $XLFLAG])
-fi 
+fi
 if test "x$xdvi_have_xaw" = xyes; then
   prog_extension="xaw"
   AC_DEFINE([XAW], 1, [Define to use the Xaw toolkit.])
+
+  # We need the type of the "list" parameter to XawListChange
+  # (the second parameter), for use in gui/pagesel.c. See more comments there.
+  #
+  AC_MSG_CHECKING([for type of XawListChange list parameter])
+  # Although we could try to use the compiler to discern the location of
+  # <X11/Xaw/List.h>, that seems likely to have its own problems. Let's
+  # try just assuming the standard location.
+  #
+  listh=/usr/include/X11/Xaw/List.h
+
+  # Clearly this simple search is subject to plenty of problems in
+  # theory, but in practice, if no one gratuitously changes the
+  # formatting in Xaw/List.h, it should be ok? The line intended to be
+  # matched looks like
+  #   String                      *list, [except with tabs]
+  # or
+  #   _Xconst char *list,
+  # or who knows what else. Hopefully it will be the complete type.
+  #
+  list_type=`sed -n 's/list,$//p' $listh`
+  #
+  # The type ordinarily has lots of whitespace, as in the String line above.
+  # People will uselessly complain about that, so reduce it to a single space:
+  tab='	' # that's a tab character
+  # The outer square brackets are the Autoconf quote pair;
+  # the inner square brackets are the normal regexp character class.
+  #echo "got '$list_type' from $listh, tab=$tab." >/tmp/lh
+  list_type=`echo "$list_type" | sed ["s/[ $tab][ $tab]*/ /g"]`
+  #echo "new '$list_type' from $listh" >>/tmp/lh
+  #
+  if test -z "$list_type"; then
+    # But if we didn't find anything, default to the type of our
+    # page_labels member in pagesel.c, which has been the traditional
+    # effective behavior.
+    list_type="char **"
+  fi
+  AC_MSG_RESULT([$list_type])
+  #debug: echo "got '$list_type' from $listh" >/tmp/lh
+  #
+  # autoconf internally quotes the shell variable value with
+  # ac_define_unquoted; we don't use shell "quotes" here since the final
+  # value must not have any quotes, being a type that we want to use in
+  # a cast, not a string constant.
+  AC_DEFINE_UNQUOTED([XAWLISTCHANGELISTTYPE], $list_type,
+                     [type of XawListChange list parameter])
 else
   AC_MSG_ERROR([Sorry, you will need at least the Xaw header/library files to compile xdvik.])
 fi