Merge pull request #23162 from lewis6991/vimpatch/option_cb

vim-patch:9.0.{1330,1345,1353,1359,1369,1374}: handling new value of an option has a long "else if" chain

20 files changed, 1505 insertions, 947 deletions

diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index c63ab804af..14a07489a0 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -1687,7 +1687,7 @@ void enter_buffer(buf_T *buf)
   // May need to set the spell language.  Can only do this after the buffer
   // has been properly setup.
   if (!curbuf->b_help && curwin->w_p_spell && *curwin->w_s->b_p_spl != NUL) {
-    (void)did_set_spelllang(curwin);
+    (void)parse_spelllang(curwin);
   }
   curbuf->b_last_used = time(NULL);
 
diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index ebc34564e2..f898063fb0 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -7711,7 +7711,7 @@ static void f_spellbadword(typval_T *argvars, typval_T *rettv, EvalFuncData fptr
   const int wo_spell_save = curwin->w_p_spell;
 
   if (!curwin->w_p_spell) {
-    did_set_spelllang(curwin);
+    parse_spelllang(curwin);
     curwin->w_p_spell = true;
   }
 
@@ -7768,7 +7768,7 @@ static void f_spellsuggest(typval_T *argvars, typval_T *rettv, EvalFuncData fptr
   const int wo_spell_save = curwin->w_p_spell;
 
   if (!curwin->w_p_spell) {
-    did_set_spelllang(curwin);
+    parse_spelllang(curwin);
     curwin->w_p_spell = true;
   }
 
diff --git a/src/nvim/ex_cmds.c b/src/nvim/ex_cmds.c
index 7a77ffb4da..f276e8ae24 100644
--- a/src/nvim/ex_cmds.c
+++ b/src/nvim/ex_cmds.c
@@ -2640,7 +2640,7 @@ int do_ecmd(int fnum, char *ffname, char *sfname, exarg_T *eap, linenr_T newlnum
   // If the window options were changed may need to set the spell language.
   // Can only do this after the buffer has been properly setup.
   if (did_get_winopts && curwin->w_p_spell && *curwin->w_s->b_p_spl != NUL) {
-    (void)did_set_spelllang(curwin);
+    (void)parse_spelllang(curwin);
   }
 
   if (command == NULL) {
diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index 33a8dcafc2..c0c8a5605b 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -4277,7 +4277,7 @@ void cmdline_init(void)
 
 /// Check value of 'cedit' and set cedit_key.
 /// Returns NULL if value is OK, error message otherwise.
-const char *check_cedit(void)
+const char *did_set_cedit(optset_T *args)
 {
   if (*p_cedit == NUL) {
     cedit_key = -1;
diff --git a/src/nvim/generators/gen_options.lua b/src/nvim/generators/gen_options.lua
index 35302e1222..ecb1a0c11b 100644
--- a/src/nvim/generators/gen_options.lua
+++ b/src/nvim/generators/gen_options.lua
@@ -154,6 +154,9 @@ local dump_option = function(i, o)
     table.insert(defines,  { 'PV_' .. varname:sub(3):upper() , pv_name})
     w('    .indir=' .. pv_name)
   end
+  if o.cb then
+    w('    .opt_did_set_cb=' .. o.cb)
+  end
   if o.enable_if then
     w('#else')
     w('    .var=NULL')
diff --git a/src/nvim/insexpand.c b/src/nvim/insexpand.c
index 6624b39d0c..d6860fff30 100644
--- a/src/nvim/insexpand.c
+++ b/src/nvim/insexpand.c
@@ -2257,14 +2257,14 @@ static void copy_global_to_buflocal_cb(Callback *globcb, Callback *bufcb)
 /// Invoked when the 'completefunc' option is set. The option value can be a
 /// name of a function (string), or function(<name>) or funcref(<name>) or a
 /// lambda expression.
-void set_completefunc_option(const char **errmsg)
+const char *did_set_completefunc(optset_T *args FUNC_ATTR_UNUSED)
 {
   if (option_set_callback_func(curbuf->b_p_cfu, &cfu_cb) == FAIL) {
-    *errmsg = e_invarg;
-    return;
+    return e_invarg;
   }
 
   set_buflocal_cfu_callback(curbuf);
+  return NULL;
 }
 
 /// Copy the global 'completefunc' callback function to the buffer-local
@@ -2278,13 +2278,14 @@ void set_buflocal_cfu_callback(buf_T *buf)
 /// Invoked when the 'omnifunc' option is set. The option value can be a
 /// name of a function (string), or function(<name>) or funcref(<name>) or a
 /// lambda expression.
-void set_omnifunc_option(buf_T *buf, const char **errmsg)
+const char *did_set_omnifunc(optset_T *args)
 {
+  buf_T *buf = (buf_T *)args->os_buf;
   if (option_set_callback_func(buf->b_p_ofu, &ofu_cb) == FAIL) {
-    *errmsg = e_invarg;
-    return;
+    return e_invarg;
   }
   set_buflocal_ofu_callback(buf);
+  return NULL;
 }
 
 /// Copy the global 'omnifunc' callback function to the buffer-local 'omnifunc'
@@ -2298,7 +2299,7 @@ void set_buflocal_ofu_callback(buf_T *buf)
 /// Invoked when the 'thesaurusfunc' option is set. The option value can be a
 /// name of a function (string), or function(<name>) or funcref(<name>) or a
 /// lambda expression.
-void set_thesaurusfunc_option(const char **errmsg)
+const char *did_set_thesaurusfunc(optset_T *args FUNC_ATTR_UNUSED)
 {
   int retval;
 
@@ -2310,9 +2311,7 @@ void set_thesaurusfunc_option(const char **errmsg)
     retval = option_set_callback_func(p_tsrfu, &tsrfu_cb);
   }
 
-  if (retval == FAIL) {
-    *errmsg = e_invarg;
-  }
+  return retval == FAIL ? e_invarg : NULL;
 }
 
 /// Mark the global 'completefunc' 'omnifunc' and 'thesaurusfunc' callbacks with
diff --git a/src/nvim/lua/spell.c b/src/nvim/lua/spell.c
index 742e8720f9..37f1c5216d 100644
--- a/src/nvim/lua/spell.c
+++ b/src/nvim/lua/spell.c
@@ -39,7 +39,7 @@ int nlua_spell_check(lua_State *lstate)
   const int wo_spell_save = curwin->w_p_spell;
 
   if (!curwin->w_p_spell) {
-    did_set_spelllang(curwin);
+    parse_spelllang(curwin);
     curwin->w_p_spell = true;
   }
 
diff --git a/src/nvim/mapping.c b/src/nvim/mapping.c
index 9a835e0eb8..c1d02e89b8 100644
--- a/src/nvim/mapping.c
+++ b/src/nvim/mapping.c
@@ -2386,7 +2386,7 @@ void langmap_init(void)
 
 /// Called when langmap option is set; the language map can be
 /// changed at any time!
-void langmap_set(void)
+const char *did_set_langmap(optset_T *args)
 {
   char *p;
   char *p2;
@@ -2434,9 +2434,10 @@ void langmap_set(void)
         }
       }
       if (to == NUL) {
-        semsg(_("E357: 'langmap': Matching character missing for %s"),
-              transchar(from));
-        return;
+        snprintf(args->os_errbuf, args->os_errbuflen,
+                 _("E357: 'langmap': Matching character missing for %s"),
+                 transchar(from));
+        return args->os_errbuf;
       }
 
       if (from >= 256) {
@@ -2454,8 +2455,10 @@ void langmap_set(void)
           p = p2;
           if (p[0] != NUL) {
             if (p[0] != ',') {
-              semsg(_("E358: 'langmap': Extra characters after semicolon: %s"), p);
-              return;
+              snprintf(args->os_errbuf, args->os_errbuflen,
+                       _("E358: 'langmap': Extra characters after semicolon: %s"),
+                       p);
+              return args->os_errbuf;
             }
             p++;
           }
@@ -2464,6 +2467,8 @@ void langmap_set(void)
       }
     }
   }
+
+  return NULL;
 }
 
 static void do_exmap(exarg_T *eap, int isabbrev)
diff --git a/src/nvim/ops.c b/src/nvim/ops.c
index 2919b94d41..89fe9b464d 100644
--- a/src/nvim/ops.c
+++ b/src/nvim/ops.c
@@ -5628,11 +5628,12 @@ static void op_colon(oparg_T *oap)
 static Callback opfunc_cb;
 
 /// Process the 'operatorfunc' option value.
-void set_operatorfunc_option(const char **errmsg)
+const char *did_set_operatorfunc(optset_T *args FUNC_ATTR_UNUSED)
 {
   if (option_set_callback_func(p_opfunc, &opfunc_cb) == FAIL) {
-    *errmsg = e_invarg;
+    return e_invarg;
   }
+  return NULL;
 }
 
 #if defined(EXITFREE)
diff --git a/src/nvim/option.c b/src/nvim/option.c
index 040ab1b847..3264d80a2f 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -84,6 +84,7 @@
 #include "nvim/path.h"
 #include "nvim/popupmenu.h"
 #include "nvim/pos.h"
+#include "nvim/quickfix.h"
 #include "nvim/regexp.h"
 #include "nvim/runtime.h"
 #include "nvim/search.h"
@@ -135,17 +136,6 @@ static long p_tw_nopaste;
 static long p_wm_nopaste;
 static char *p_vsts_nopaste;
 
-// options[] is initialized here.
-// The order of the options MUST be alphabetic for ":set all" and findoption().
-// All option names MUST start with a lowercase letter (for findoption()).
-// Exception: "t_" options are at the end.
-// The options with a NULL variable are 'hidden': a set command for them is
-// ignored and they are not printed.
-
-#ifdef INCLUDE_GENERATED_DECLARATIONS
-# include "options.generated.h"
-#endif
-
 #define OPTION_COUNT ARRAY_SIZE(options)
 
 typedef enum {
@@ -159,6 +149,17 @@ typedef enum {
 # include "option.c.generated.h"
 #endif
 
+// options[] is initialized here.
+// The order of the options MUST be alphabetic for ":set all" and findoption().
+// All option names MUST start with a lowercase letter (for findoption()).
+// Exception: "t_" options are at the end.
+// The options with a NULL variable are 'hidden': a set command for them is
+// ignored and they are not printed.
+
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "options.generated.h"
+#endif
+
 void set_init_tablocal(void)
 {
   // susy baka: cmdheight calls itself OPT_GLOBAL but is really tablocal!
@@ -1237,7 +1238,7 @@ static void do_set_option_string(int opt_idx, int opt_flags, char **argp, int ne
     // Handle side effects, and set the global value for ":set" on local
     // options. Note: when setting 'syntax' or 'filetype' autocommands may
     // be triggered that can cause havoc.
-    *errmsg = did_set_string_option(opt_idx, (char **)varp, oldval,
+    *errmsg = did_set_string_option(opt_idx, (char **)varp, oldval, newval,
                                     errbuf, errbuflen,
                                     opt_flags, value_checked);
 
@@ -1840,9 +1841,9 @@ static void didset_options(void)
   (void)compile_cap_prog(curwin->w_s);
   (void)did_set_spell_option(true);
   // set cedit_key
-  (void)check_cedit();
+  (void)did_set_cedit(NULL);
   // initialize the table for 'breakat'.
-  fill_breakat_flags();
+  (void)did_set_breakat(NULL);
   didset_window_options(curwin, true);
 }
 
@@ -1853,10 +1854,10 @@ static void didset_options2(void)
   highlight_changed();
 
   // Parse default for 'fillchars'.
-  (void)set_chars_option(curwin, &curwin->w_p_fcs, true);
+  (void)set_fillchars_option(curwin, curwin->w_p_fcs, true);
 
   // Parse default for 'listchars'.
-  (void)set_chars_option(curwin, &curwin->w_p_lcs, true);
+  (void)set_listchars_option(curwin, curwin->w_p_lcs, true);
 
   // Parse default for 'wildmode'.
   check_opt_wim();
@@ -2101,25 +2102,27 @@ static const char *did_set_force_off(bool *doskip)
 }
 
 /// Process the updated 'langremap' option value.
-static void did_set_langremap(void)
+static const char *did_set_langremap(optset_T *args FUNC_ATTR_UNUSED)
 {
   // 'langremap' -> !'langnoremap'
   p_lnr = !p_lrm;
+  return NULL;
 }
 
 /// Process the updated 'langnoremap' option value.
-static void did_set_langnoremap(void)
+static const char *did_set_langnoremap(optset_T *args FUNC_ATTR_UNUSED)
 {
   // 'langnoremap' -> !'langremap'
   p_lrm = !p_lnr;
+  return NULL;
 }
 
 /// Process the updated 'undofile' option value.
-static void did_set_undofile(int opt_flags)
+static const char *did_set_undofile(optset_T *args)
 {
   // Only take action when the option was set.
   if (!curbuf->b_p_udf && !p_udf) {
-    return;
+    return NULL;
   }
 
   // When reset we do not delete the undo file, the option may be set again
@@ -2132,19 +2135,21 @@ static void did_set_undofile(int opt_flags)
     // if one exists, the buffer wasn't changed and the buffer was
     // loaded
     if ((curbuf == bp
-         || (opt_flags & OPT_GLOBAL) || opt_flags == 0)
+         || (args->os_flags & OPT_GLOBAL) || args->os_flags == 0)
         && !bufIsChanged(bp) && bp->b_ml.ml_mfp != NULL) {
       u_compute_hash(bp, hash);
       u_read_undo(NULL, hash, bp->b_fname);
     }
   }
+
+  return NULL;
 }
 
 /// Process the updated 'readonly' option value.
-static void did_set_readonly(int opt_flags)
+static const char *did_set_readonly(optset_T *args)
 {
   // when 'readonly' is reset globally, also reset readonlymode
-  if (!curbuf->b_p_ro && (opt_flags & OPT_LOCAL) == 0) {
+  if (!curbuf->b_p_ro && (args->os_flags & OPT_LOCAL) == 0) {
     readonlymode = false;
   }
 
@@ -2154,10 +2159,12 @@ static void did_set_readonly(int opt_flags)
   }
 
   redraw_titles();
+
+  return NULL;
 }
 
 /// Process the updated 'modifiable' option value.
-static char *did_set_modifiable(void)
+static const char *did_set_modifiable(optset_T *args FUNC_ATTR_UNUSED)
 {
   // when 'modifiable' is changed, redraw the window title
   redraw_titles();
@@ -2167,90 +2174,108 @@ static char *did_set_modifiable(void)
 
 /// Process the updated 'endoffile' or 'endofline' or 'fixendofline' or 'bomb'
 /// option value.
-static void did_set_eof_eol_fixeol_bomb(void)
+static const char *did_set_eof_eol_fixeol_bomb(optset_T *args FUNC_ATTR_UNUSED)
 {
   // redraw the window title and tab page text
   redraw_titles();
+  return NULL;
 }
 
 /// Process the updated 'binary' option value.
-static void did_set_binary(int opt_flags, long old_value)
+static const char *did_set_binary(optset_T *args)
 {
+  buf_T *buf = (buf_T *)args->os_buf;
+
   // when 'bin' is set also set some other options
-  set_options_bin((int)old_value, curbuf->b_p_bin, opt_flags);
+  set_options_bin((int)args->os_oldval.boolean, buf->b_p_bin, args->os_flags);
   redraw_titles();
+
+  return NULL;
 }
 
 /// Process the updated 'buflisted' option value.
-static void did_set_buflisted(long old_value)
+static const char *did_set_buflisted(optset_T *args)
 {
+  buf_T *buf = (buf_T *)args->os_buf;
+
   // when 'buflisted' changes, trigger autocommands
-  if (old_value != curbuf->b_p_bl) {
-    apply_autocmds(curbuf->b_p_bl ? EVENT_BUFADD : EVENT_BUFDELETE,
-                   NULL, NULL, true, curbuf);
+  if (args->os_oldval.boolean != buf->b_p_bl) {
+    apply_autocmds(buf->b_p_bl ? EVENT_BUFADD : EVENT_BUFDELETE,
+                   NULL, NULL, true, buf);
   }
+  return NULL;
 }
 
 /// Process the updated 'swapfile' option value.
-static void did_set_swapfile(void)
+static const char *did_set_swapfile(optset_T *args)
 {
+  buf_T *buf = (buf_T *)args->os_buf;
   // when 'swf' is set, create swapfile, when reset remove swapfile
-  if (curbuf->b_p_swf && p_uc) {
-    ml_open_file(curbuf);                     // create the swap file
+  if (buf->b_p_swf && p_uc) {
+    ml_open_file(buf);                     // create the swap file
   } else {
     // no need to reset curbuf->b_may_swap, ml_open_file() will check
     // buf->b_p_swf
-    mf_close_file(curbuf, true);              // remove the swap file
+    mf_close_file(buf, true);              // remove the swap file
   }
+  return NULL;
 }
 
 /// Process the updated 'paste' option value.
-static void did_set_paste(void)
+static const char *did_set_paste(optset_T *args FUNC_ATTR_UNUSED)
 {
   // when 'paste' is set or reset also change other options
   paste_option_changed();
+  return NULL;
 }
 
 /// Process the updated 'ignorecase' option value.
-static void did_set_ignorecase(void)
+static const char *did_set_ignorecase(optset_T *args FUNC_ATTR_UNUSED)
 {
   // when 'ignorecase' is set or reset and 'hlsearch' is set, redraw
   if (p_hls) {
     redraw_all_later(UPD_SOME_VALID);
   }
+  return NULL;
 }
 
 /// Process the updated 'hlsearch' option value.
-static void did_set_hlsearch(void)
+static const char *did_set_hlsearch(optset_T *args FUNC_ATTR_UNUSED)
 {
   // when 'hlsearch' is set or reset: reset no_hlsearch
   set_no_hlsearch(false);
+  return NULL;
 }
 
 /// Process the updated 'scrollbind' option value.
-static void did_set_scrollbind(void)
+static const char *did_set_scrollbind(optset_T *args)
 {
+  win_T *win = (win_T *)args->os_win;
+
   // when 'scrollbind' is set: snapshot the current position to avoid a jump
   // at the end of normal_cmd()
-  if (!curwin->w_p_scb) {
-    return;
+  if (!win->w_p_scb) {
+    return NULL;
   }
   do_check_scrollbind(false);
-  curwin->w_scbind_pos = curwin->w_topline;
+  win->w_scbind_pos = win->w_topline;
+  return NULL;
 }
 
 /// Process the updated 'previewwindow' option value.
-static const char *did_set_previewwindow(bool *doskip)
+static const char *did_set_previewwindow(optset_T *args)
 {
-  if (!curwin->w_p_pvw) {
+  win_T *win = (win_T *)args->os_win;
+
+  if (!win->w_p_pvw) {
     return NULL;
   }
 
   // There can be only one window with 'previewwindow' set.
-  FOR_ALL_WINDOWS_IN_TAB(win, curtab) {
-    if (win->w_p_pvw && win != curwin) {
-      curwin->w_p_pvw = false;
-      *doskip = true;
+  FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
+    if (wp->w_p_pvw && wp != win) {
+      win->w_p_pvw = false;
+      args->os_doskip = true;
       return e_preview_window_already_exists;
     }
   }
@@ -2259,32 +2284,37 @@ static const char *did_set_previewwindow(bool *doskip)
 }
 
 /// Process the updated 'lisp' option value.
-static void did_set_lisp(void)
+static const char *did_set_lisp(optset_T *args)
 {
+  buf_T *buf = (buf_T *)args->os_buf;
   // When 'lisp' option changes include/exclude '-' in keyword characters.
-  (void)buf_init_chartab(curbuf, false);          // ignore errors
+  (void)buf_init_chartab(buf, false);          // ignore errors
+  return NULL;
 }
 
 /// Process the updated 'title' or the 'icon' option value.
-static void did_set_title_icon(void)
+static const char *did_set_title_icon(optset_T *args FUNC_ATTR_UNUSED)
 {
   // when 'title' changed, may need to change the title; same for 'icon'
   did_set_title();
+  return NULL;
 }
 
 /// Process the updated 'modified' option value.
-static void did_set_modified(long value)
+static const char *did_set_modified(optset_T *args)
 {
-  if (!value) {
-    save_file_ff(curbuf);  // Buffer is unchanged
+  buf_T *buf = (buf_T *)args->os_buf;
+  if (!args->os_newval.boolean) {
+    save_file_ff(buf);  // Buffer is unchanged
   }
   redraw_titles();
-  modified_was_set = (int)value;
+  modified_was_set = (int)args->os_newval.boolean;
+  return NULL;
 }
 
 #ifdef BACKSLASH_IN_FILENAME
 /// Process the updated 'shellslash' option value.
-static void did_set_shellslash(void)
+static const char *did_set_shellslash(optset_T *args FUNC_ATTR_UNUSED)
 {
   if (p_ssl) {
     psepc = '/';
@@ -2300,63 +2330,76 @@ static void did_set_shellslash(void)
   buflist_slash_adjust();
   alist_slash_adjust();
   scriptnames_slash_adjust();
+  return NULL;
 }
 #endif
 
 /// Process the updated 'wrap' option value.
-static void did_set_wrap(void)
+static const char *did_set_wrap(optset_T *args)
 {
+  win_T *win = (win_T *)args->os_win;
+
   // If 'wrap' is set, set w_leftcol to zero.
-  if (curwin->w_p_wrap) {
-    curwin->w_leftcol = 0;
+  if (win->w_p_wrap) {
+    win->w_leftcol = 0;
   }
+  return NULL;
 }
 
 /// Process the updated 'equalalways' option value.
-static void did_set_equalalways(long old_value)
+static const char *did_set_equalalways(optset_T *args)
 {
-  if (p_ea && !old_value) {
-    win_equal(curwin, false, 0);
+  win_T *win = (win_T *)args->os_win;
+  if (p_ea && !args->os_oldval.boolean) {
+    win_equal(win, false, 0);
   }
+
+  return NULL;
 }
 
 /// Process the updated 'autochdir' option value.
-static void did_set_autochdir(void)
+static const char *did_set_autochdir(optset_T *args FUNC_ATTR_UNUSED)
 {
   // Change directories when the 'acd' option is set now.
   do_autochdir();
+  return NULL;
 }
 
 /// Process the updated 'diff' option value.
-static void did_set_diff(void)
+static const char *did_set_diff(optset_T *args)
 {
+  win_T *win = (win_T *)args->os_win;
   // May add or remove the buffer from the list of diff buffers.
-  diff_buf_adjust(curwin);
-  if (foldmethodIsDiff(curwin)) {
-    foldUpdateAll(curwin);
+  diff_buf_adjust(win);
+  if (foldmethodIsDiff(win)) {
+    foldUpdateAll(win);
   }
+  return NULL;
 }
 
 /// Process the updated 'spell' option value.
-static char *did_set_spell(void)
+static const char *did_set_spell(optset_T *args)
 {
-  if (curwin->w_p_spell) {
-    return did_set_spelllang(curwin);
+  win_T *win = (win_T *)args->os_win;
+  if (win->w_p_spell) {
+    return parse_spelllang(win);
   }
 
   return NULL;
 }
 
 /// Process the updated 'arabic' option value.
-static const char *did_set_arabic(void)
+static const char *did_set_arabic(optset_T *args)
 {
+  win_T *win = (win_T *)args->os_win;
   const char *errmsg = NULL;
-  if (curwin->w_p_arab) {
+
+  if (win->w_p_arab) {
     // 'arabic' is set, handle various sub-settings.
     if (!p_tbidi) {
       // set rightleft mode
-      if (!curwin->w_p_rl) {
-        curwin->w_p_rl = true;
+      if (!win->w_p_rl) {
+        win->w_p_rl = true;
         changed_window_setting();
       }
 
@@ -2386,8 +2429,8 @@ static const char *did_set_arabic(void)
     // 'arabic' is reset, handle various sub-settings.
     if (!p_tbidi) {
       // reset rightleft mode
-      if (curwin->w_p_rl) {
-        curwin->w_p_rl = false;
+      if (win->w_p_rl) {
+        win->w_p_rl = false;
         changed_window_setting();
       }
 
@@ -2406,85 +2449,15 @@ static const char *did_set_arabic(void)
   return errmsg;
 }
 
-static void did_set_number_relativenumber(void)
+/// Process the updated 'number' or 'relativenumber' option value.
+static const char *did_set_number_relativenumber(optset_T *args)
 {
-  if (*curwin->w_p_stc != NUL) {
+  win_T *win = (win_T *)args->os_win;
+  if (*win->w_p_stc != NUL) {
     // When 'relativenumber'/'number' is changed and 'statuscolumn' is set, reset width.
-    curwin->w_nrwidth_line_count = 0;
+    win->w_nrwidth_line_count = 0;
   }
-}
-
-/// When some boolean options are changed, need to take some action.
-static const char *did_set_bool_option(const char *varp, int opt_flags, long value, long old_value,
-                                       bool *doskip)
-{
-  const char *errmsg = NULL;
-
-  if ((int *)varp == &p_force_on) {
-    errmsg = did_set_force_on(doskip);
-  } else if ((int *)varp == &p_force_off) {
-    errmsg = did_set_force_off(doskip);
-  } else if ((int *)varp == &p_lrm) {              // 'langremap'
-    did_set_langremap();
-  } else if ((int *)varp == &p_lnr) {              // 'langnoremap'
-    did_set_langnoremap();
-  } else if ((int *)varp == &curbuf->b_p_udf      // buffer local 'undofile'
-             || (int *)varp == &p_udf) {         // 'undofile'
-    did_set_undofile(opt_flags);
-  } else if ((int *)varp == &curbuf->b_p_ro) {     // 'readonly'
-    did_set_readonly(opt_flags);
-  } else if ((int *)varp == &curbuf->b_p_ma) {
-    errmsg = did_set_modifiable();        // 'modifiable'
-  } else if ((int *)varp == &curbuf->b_p_eof      // 'endoffile'
-             || (int *)varp == &curbuf->b_p_eol  // 'endofline'
-             || (int *)varp == &curbuf->b_p_fixeol       // 'fixendofline'
-             || (int *)varp == &curbuf->b_p_bomb) {      // 'bomb'
-    did_set_eof_eol_fixeol_bomb();
-  } else if ((int *)varp == &curbuf->b_p_bin) {    // 'binary'
-    did_set_binary(opt_flags, old_value);
-  } else if ((int *)varp == &curbuf->b_p_bl) {     // 'buflisted'
-    did_set_buflisted(old_value);
-  } else if ((int *)varp == &curbuf->b_p_swf) {    // 'swapfile'
-    did_set_swapfile();
-  } else if ((int *)varp == &p_paste) {            // 'paste'
-    did_set_paste();
-  } else if ((int *)varp == &p_ic) {       // 'ignorecase'
-    did_set_ignorecase();
-  } else if ((int *)varp == &p_hls) {      // 'hlsearch'
-    did_set_hlsearch();
-  } else if ((int *)varp == &curwin->w_p_scb) {    // 'scrollbind'
-    did_set_scrollbind();
-  } else if ((int *)varp == &curwin->w_p_pvw) {    // 'previewwindow'
-    errmsg = did_set_previewwindow(doskip);
-  } else if (varp == (char *)&(curbuf->b_p_lisp)) {      // 'lisp'
-    did_set_lisp();
-  } else if ((int *)varp == &p_title            // 'title'
-             || (int *)varp == &p_icon) {        // 'icon'
-    did_set_title_icon();
-  } else if ((int *)varp == &curbuf->b_changed) {  // 'modified'
-    did_set_modified(value);
-#ifdef BACKSLASH_IN_FILENAME
-  } else if ((int *)varp == &p_ssl) {              // 'shellslash'
-    did_set_shellslash();
-#endif
-  } else if ((int *)varp == &curwin->w_p_wrap) {   // 'wrap'
-    did_set_wrap();
-  } else if ((int *)varp == &p_ea) {               // 'equalalways'
-    did_set_equalalways(old_value);
-  } else if ((int *)varp == &p_acd) {              // 'autochdir'
-    did_set_autochdir();
-  } else if ((int *)varp == &curwin->w_p_diff) {   // 'diff'
-    did_set_diff();
-  } else if ((int *)varp == &curwin->w_p_spell) {  // 'spell'
-    errmsg = did_set_spell();
-  } else if ((int *)varp == &curwin->w_p_arab) {   // 'arabic'
-    errmsg = did_set_arabic();
-  } else if ((int *)varp == &curwin->w_p_nu        // 'number'
-             || (int *)varp == &curwin->w_p_rnu) {  // 'relativenumber'
-    did_set_number_relativenumber();
-  }
-
-  return errmsg;
+  return NULL;
 }
 
 /// Set the value of a boolean option, taking care of side effects
@@ -2524,8 +2497,28 @@ static const char *set_bool_option(const int opt_idx, char *const varp, const in
   }
 
   // Handle side effects for changing a bool option.
+  const char *errmsg = NULL;
   bool doskip = false;
-  const char *errmsg = did_set_bool_option(varp, opt_flags, value, old_value, &doskip);
+  if ((int *)varp == &p_force_on) {
+    errmsg = did_set_force_on(&doskip);
+  } else if ((int *)varp == &p_force_off) {
+    errmsg = did_set_force_off(&doskip);
+  } else if (options[opt_idx].opt_did_set_cb != NULL) {
+    optset_T args = {
+      .os_varp = varp,
+      .os_flags = opt_flags,
+      .os_oldval.boolean = old_value,
+      .os_newval.boolean = value,
+      .os_doskip = false,
+      .os_errbuf = NULL,
+      .os_errbuflen = 0,
+      .os_buf = curbuf,
+      .os_win = curwin
+    };
+
+    errmsg = options[opt_idx].opt_did_set_cb(&args);
+    doskip = args.os_doskip;
+  }
   if (doskip) {
     return errmsg;
   }
@@ -2557,38 +2550,51 @@ static const char *set_bool_option(const int opt_idx, char *const varp, const in
 }
 
 /// Process the new 'winheight' value.
-static void did_set_winheight(win_T *win, long value)
+static const char *did_set_winheight(optset_T *args)
 {
   // Change window height NOW
   if (!ONE_WINDOW) {
-    if (win->w_height < value) {
-      win_setheight((int)value);
+    win_T *win = (win_T *)args->os_win;
+    if (win->w_height < p_wh) {
+      win_setheight((int)p_wh);
     }
   }
+
+  return NULL;
 }
 
 /// Process the new 'helpheight' option value.
-static void did_set_helpheight(buf_T *buf, win_T *win, long value)
+static const char *did_set_helpheight(optset_T *args)
 {
   // Change window height NOW
   if (!ONE_WINDOW) {
-    if (buf->b_help && win->w_height < value) {
-      win_setheight((int)value);
+    buf_T *buf = (buf_T *)args->os_buf;
+    win_T *win = (win_T *)args->os_win;
+    if (buf->b_help && win->w_height < p_hh) {
+      win_setheight((int)p_hh);
     }
   }
+
+  return NULL;
 }
 
 /// Process the new 'winwidth' option value.
-static void did_set_winwidth(win_T *win, long value)
+static const char *did_set_winwidth(optset_T *args)
 {
-  if (!ONE_WINDOW && win->w_width < value) {
-    win_setwidth((int)value);
+  win_T *win = (win_T *)args->os_win;
+
+  if (!ONE_WINDOW && win->w_width < p_wiw) {
+    win_setwidth((int)p_wiw);
   }
+  return NULL;
 }
 
 /// Process the new 'laststatus' option value.
-static void did_set_laststatus(long value, long old_value)
+static const char *did_set_laststatus(optset_T *args)
 {
+  long old_value = args->os_oldval.number;
+  long value = args->os_newval.number;
+
   // When switching to global statusline, decrease topframe height
   // Also clear the cmdline to remove the ruler if there is one
   if (value == 3 && old_value != 3) {
@@ -2604,38 +2610,49 @@ static void did_set_laststatus(long value, long old_value)
   }
 
   last_status(false);  // (re)set last window status line.
+  return NULL;
 }
 
 /// Process the new 'showtabline' option value.
-static void did_set_showtabline(void)
+static const char *did_set_showtabline(optset_T *args FUNC_ATTR_UNUSED)
 {
   // (re)set tab page line
   win_new_screen_rows();  // recompute window positions and heights
+  return NULL;
 }
 
 /// Process the new 'foldlevel' option value.
-static void did_set_foldlevel(void)
+static const char *did_set_foldlevel(optset_T *args FUNC_ATTR_UNUSED)
 {
   newFoldLevel();
+  return NULL;
 }
 
 /// Process the new 'foldminlines' option value.
-static void did_set_foldminlines(win_T *win)
+static const char *did_set_foldminlines(optset_T *args)
 {
+  win_T *win = (win_T *)args->os_win;
   foldUpdateAll(win);
+  return NULL;
 }
 
 /// Process the new 'foldnestmax' option value.
-static void did_set_foldnestmax(win_T *win)
+static const char *did_set_foldnestmax(optset_T