refactor(options): remove `set_string_option_direct()`

Problem: `set_string_option_direct()` contains a separate codepath specifically for setting string options. Not only is that unnecessary code duplication, but it's also limited to only string options.

Solution: Replace `set_string_option_direct()` with `set_option_direct()` which calls `set_option()` under the hood. This reduces code duplication and allows directly setting an option of any type.

15 files changed, 93 insertions, 135 deletions

diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
index 43bf4eaf31..2b3ebb7bfb 100644
--- a/src/nvim/api/vim.c
+++ b/src/nvim/api/vim.c
@@ -988,8 +988,10 @@ Buffer nvim_create_buf(Boolean listed, Boolean scratch, Error *err)
   buf_copy_options(buf, BCO_ENTER | BCO_NOHELP);
 
   if (scratch) {
-    set_string_option_direct_in_buf(buf, kOptBufhidden, "hide", OPT_LOCAL, 0);
-    set_string_option_direct_in_buf(buf, kOptBuftype, "nofile", OPT_LOCAL, 0);
+    set_option_direct_for(kOptBufhidden, STATIC_CSTR_AS_OPTVAL("hide"), OPT_LOCAL, 0, kOptReqBuf,
+                          buf);
+    set_option_direct_for(kOptBuftype, STATIC_CSTR_AS_OPTVAL("nofile"), OPT_LOCAL, 0, kOptReqBuf,
+                          buf);
     assert(buf->b_ml.ml_mfp->mf_fd < 0);  // ml_open() should not have opened swapfile already
     buf->b_p_swf = false;
     buf->b_p_ml = false;
diff --git a/src/nvim/autocmd.c b/src/nvim/autocmd.c
index 285ef538b9..00cfef23c7 100644
--- a/src/nvim/autocmd.c
+++ b/src/nvim/autocmd.c
@@ -712,7 +712,7 @@ char *au_event_disable(char *what)
   } else {
     STRCAT(new_ei, what);
   }
-  set_string_option_direct(kOptEventignore, new_ei, 0, SID_NONE);
+  set_option_direct(kOptEventignore, CSTR_AS_OPTVAL(new_ei), 0, SID_NONE);
   xfree(new_ei);
   return save_ei;
 }
@@ -720,7 +720,7 @@ char *au_event_disable(char *what)
 void au_event_restore(char *old_ei)
 {
   if (old_ei != NULL) {
-    set_string_option_direct(kOptEventignore, old_ei, 0, SID_NONE);
+    set_option_direct(kOptEventignore, CSTR_AS_OPTVAL(old_ei), 0, SID_NONE);
     xfree(old_ei);
   }
 }
diff --git a/src/nvim/diff.c b/src/nvim/diff.c
index 39d9e9e978..ea846b46ec 100644
--- a/src/nvim/diff.c
+++ b/src/nvim/diff.c
@@ -1438,7 +1438,8 @@ void diff_win_options(win_T *wp, bool addbuf)
     }
     wp->w_p_fdm_save = xstrdup(wp->w_p_fdm);
   }
-  set_string_option_direct_in_win(wp, kOptFoldmethod, "diff", OPT_LOCAL, 0);
+  set_option_direct_for(kOptFoldmethod, STATIC_CSTR_AS_OPTVAL("diff"), OPT_LOCAL, 0, kOptReqWin,
+                        wp);
 
   if (!wp->w_p_diff) {
     wp->w_p_fen_save = wp->w_p_fen;
diff --git a/src/nvim/ex_cmds.c b/src/nvim/ex_cmds.c
index 7c49189602..dd30cdbba4 100644
--- a/src/nvim/ex_cmds.c
+++ b/src/nvim/ex_cmds.c
@@ -4294,7 +4294,7 @@ skip:
   // Show 'inccommand' preview if there are matched lines.
   if (cmdpreview_ns > 0 && !aborting()) {
     if (got_quit || profile_passed_limit(timeout)) {  // Too slow, disable.
-      set_string_option_direct(kOptInccommand, "", 0, SID_NONE);
+      set_option_direct(kOptInccommand, STATIC_CSTR_AS_OPTVAL(""), 0, SID_NONE);
     } else if (*p_icm != NUL && pat != NULL) {
       if (pre_hl_id == 0) {
         pre_hl_id = syn_check_group(S_LEN("Substitute"));
@@ -4574,7 +4574,7 @@ bool prepare_tagpreview(bool undo_sync)
   RESET_BINDING(curwin);                // don't take over 'scrollbind' and 'cursorbind'
   curwin->w_p_diff = false;             // no 'diff'
 
-  set_string_option_direct(kOptFoldcolumn, "0", 0, SID_NONE);  // no 'foldcolumn'
+  set_option_direct(kOptFoldcolumn, STATIC_CSTR_AS_OPTVAL("0"), 0, SID_NONE);  // no 'foldcolumn'
   return true;
 }
 
@@ -4593,7 +4593,7 @@ static int show_sub(exarg_T *eap, pos_T old_cusr, PreviewLines *preview_lines, i
   buf_T *cmdpreview_buf = NULL;
 
   // disable file info message
-  set_string_option_direct(kOptShortmess, "F", 0, SID_NONE);
+  set_option_direct(kOptShortmess, STATIC_CSTR_AS_OPTVAL("F"), 0, SID_NONE);
 
   // Place cursor on nearest matching line, to undo do_sub() cursor placement.
   for (size_t i = 0; i < lines.subresults.size; i++) {
@@ -4694,7 +4694,7 @@ static int show_sub(exarg_T *eap, pos_T old_cusr, PreviewLines *preview_lines, i
 
   xfree(str);
 
-  set_string_option_direct(kOptShortmess, save_shm_p, 0, SID_NONE);
+  set_option_direct(kOptShortmess, CSTR_AS_OPTVAL(save_shm_p), 0, SID_NONE);
   xfree(save_shm_p);
 
   return preview ? 2 : 1;
diff --git a/src/nvim/ex_docmd.c b/src/nvim/ex_docmd.c
index 6db72ff2d1..2454c77334 100644
--- a/src/nvim/ex_docmd.c
+++ b/src/nvim/ex_docmd.c
@@ -2697,7 +2697,7 @@ static void apply_cmdmod(cmdmod_T *cmod)
     // Set 'eventignore' to "all".
     // First save the existing option value for restoring it later.
     cmod->cmod_save_ei = xstrdup(p_ei);
-    set_string_option_direct(kOptEventignore, "all", 0, SID_NONE);
+    set_option_direct(kOptEventignore, STATIC_CSTR_AS_OPTVAL("all"), 0, SID_NONE);
   }
 }
 
@@ -2717,7 +2717,7 @@ void undo_cmdmod(cmdmod_T *cmod)
 
   if (cmod->cmod_save_ei != NULL) {
     // Restore 'eventignore' to the value before ":noautocmd".
-    set_string_option_direct(kOptEventignore, cmod->cmod_save_ei, 0, SID_NONE);
+    set_option_direct(kOptEventignore, CSTR_AS_OPTVAL(cmod->cmod_save_ei), 0, SID_NONE);
     free_string_option(cmod->cmod_save_ei);
     cmod->cmod_save_ei = NULL;
   }
diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index e5d82cc126..a4501a31c2 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -919,7 +919,7 @@ static uint8_t *command_line_enter(int firstc, int count, int indent, bool clear
     need_wait_return = false;
   }
 
-  set_string_option_direct(kOptInccommand, s->save_p_icm, 0, SID_NONE);
+  set_option_direct(kOptInccommand, CSTR_AS_OPTVAL(s->save_p_icm), 0, SID_NONE);
   State = s->save_State;
   if (cmdpreview != save_cmdpreview) {
     cmdpreview = save_cmdpreview;  // restore preview state
@@ -2554,7 +2554,7 @@ static bool cmdpreview_may_show(CommandLineState *s)
   // Open preview buffer if inccommand=split.
   if (icm_split && (cmdpreview_buf = cmdpreview_open_buf()) == NULL) {
     // Failed to create preview buffer, so disable preview.
-    set_string_option_direct(kOptInccommand, "nosplit", 0, SID_NONE);
+    set_option_direct(kOptInccommand, STATIC_CSTR_AS_OPTVAL("nosplit"), 0, SID_NONE);
     icm_split = false;
   }
   // Setup preview namespace if it's not already set.
diff --git a/src/nvim/fileio.c b/src/nvim/fileio.c
index f032604a59..6b50b031a3 100644
--- a/src/nvim/fileio.c
+++ b/src/nvim/fileio.c
@@ -1620,7 +1620,7 @@ failed:
     save_file_ff(curbuf);
     // If editing a new file: set 'fenc' for the current buffer.
     // Also for ":read ++edit file".
-    set_string_option_direct(kOptFileencoding, fenc, OPT_LOCAL, 0);
+    set_option_direct(kOptFileencoding, CSTR_AS_OPTVAL(fenc), OPT_LOCAL, 0);
   }
   if (fenc_alloced) {
     xfree(fenc);
@@ -1968,7 +1968,7 @@ void set_forced_fenc(exarg_T *eap)
   }
 
   char *fenc = enc_canonize(eap->cmd + eap->force_enc);
-  set_string_option_direct(kOptFileencoding, fenc, OPT_LOCAL, 0);
+  set_option_direct(kOptFileencoding, CSTR_AS_OPTVAL(fenc), OPT_LOCAL, 0);
   xfree(fenc);
 }
 
diff --git a/src/nvim/help.c b/src/nvim/help.c
index 779772cedf..e9f67ca3e4 100644
--- a/src/nvim/help.c
+++ b/src/nvim/help.c
@@ -613,7 +613,7 @@ void cleanup_help_tags(int num_file, char **file)
 void prepare_help_buffer(void)
 {
   curbuf->b_help = true;
-  set_string_option_direct(kOptBuftype, "help", OPT_LOCAL, 0);
+  set_option_direct(kOptBuftype, STATIC_CSTR_AS_OPTVAL("help"), OPT_LOCAL, 0);
 
   // Always set these options after jumping to a help tag, because the
   // user may have an autocommand that gets in the way.
@@ -622,13 +622,13 @@ void prepare_help_buffer(void)
   // Only set it when needed, buf_init_chartab() is some work.
   char *p = "!-~,^*,^|,^\",192-255";
   if (strcmp(curbuf->b_p_isk, p) != 0) {
-    set_string_option_direct(kOptIskeyword, p, OPT_LOCAL, 0);
+    set_option_direct(kOptIskeyword, CSTR_AS_OPTVAL(p), OPT_LOCAL, 0);
     check_buf_options(curbuf);
     buf_init_chartab(curbuf, false);
   }
 
   // Don't use the global foldmethod.
-  set_string_option_direct(kOptFoldmethod, "manual", OPT_LOCAL, 0);
+  set_option_direct(kOptFoldmethod, STATIC_CSTR_AS_OPTVAL("manual"), OPT_LOCAL, 0);
 
   curbuf->b_p_ts = 8;         // 'tabstop' is 8.
   curwin->w_p_list = false;   // No list mode.
diff --git a/src/nvim/indent.c b/src/nvim/indent.c
index 6cbb86866e..d477b466d7 100644
--- a/src/nvim/indent.c
+++ b/src/nvim/indent.c
@@ -1105,7 +1105,7 @@ void ex_retab(exarg_T *eap)
     colnr_T *old_vts_ary = curbuf->b_p_vts_array;
 
     if (tabstop_count(old_vts_ary) > 0 || tabstop_count(new_vts_array) > 1) {
-      set_string_option_direct(kOptVartabstop, new_ts_str, OPT_LOCAL, 0);
+      set_option_direct(kOptVartabstop, CSTR_AS_OPTVAL(new_ts_str), OPT_LOCAL, 0);
       curbuf->b_p_vts_array = new_vts_array;
       xfree(old_vts_ary);
     } else {
diff --git a/src/nvim/main.c b/src/nvim/main.c
index ea189aaa0c..361d43393b 100644
--- a/src/nvim/main.c
+++ b/src/nvim/main.c
@@ -1573,7 +1573,7 @@ static void handle_quickfix(mparm_T *paramp)
 {
   if (paramp->edit_type == EDIT_QF) {
     if (paramp->use_ef != NULL) {
-      set_string_option_direct(kOptErrorfile, paramp->use_ef, 0, SID_CARG);
+      set_option_direct(kOptErrorfile, CSTR_AS_OPTVAL(paramp->use_ef), 0, SID_CARG);
     }
     vim_snprintf(IObuff, IOSIZE, "cfile %s", p_ef);
     if (qf_init(NULL, p_ef, p_efm, true, IObuff, p_menc) < 0) {
diff --git a/src/nvim/option.c b/src/nvim/option.c
index 5fb93f9801..73a5af5520 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -430,10 +430,9 @@ static void set_option_default(const OptIndex opt_idx, int opt_flags)
   uint32_t flags = opt->flags;
   if (varp != NULL) {       // skip hidden option, nothing to do for it
     if (option_has_type(opt_idx, kOptValTypeString)) {
-      // Use set_string_option_direct() for local options to handle freeing and allocating the
-      // value.
+      // Use set_option_direct() for local options to handle freeing and allocating the value.
       if (opt->indir != PV_NONE) {
-        set_string_option_direct(opt_idx, opt->def_val.string, opt_flags, 0);
+        set_option_direct(opt_idx, CSTR_AS_OPTVAL(opt->def_val.string), opt_flags, 0);
       } else {
         if (flags & P_ALLOCED) {
           free_string_option(*(char **)(varp));
@@ -765,7 +764,7 @@ static char *stropt_get_default_val(OptIndex opt_idx, uint64_t flags)
 }
 
 /// Copy the new string value into allocated memory for the option.
-/// Can't use set_string_option_direct(), because we need to remove the backslashes.
+/// Can't use set_option_direct(), because we need to remove the backslashes.
 static char *stropt_copy_value(char *origval, char **argp, set_op_T op,
                                uint32_t flags FUNC_ATTR_UNUSED)
 {
@@ -3762,6 +3761,68 @@ static const char *set_option(const OptIndex opt_idx, void *varp, OptVal value,
   return errmsg;
 }
 
+/// Set option value directly, without processing any side effects.
+///
+/// @param  opt_idx    Option index in options[] table.
+/// @param  value      Option value.
+/// @param  opt_flags  Option flags.
+/// @param  set_sid    Script ID. Special values:
+///                      0: Use current script ID.
+///                      SID_NONE: Don't set script ID.
+void set_option_direct(OptIndex opt_idx, OptVal value, int opt_flags, scid_T set_sid)
+{
+  static char errbuf[IOSIZE];
+
+  vimoption_T *opt = get_option(opt_idx);
+
+  if (opt->var == NULL) {
+    return;
+  }
+
+  const bool scope_both = (opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0;
+  void *varp = get_varp_scope(opt, scope_both ? OPT_LOCAL : opt_flags);
+
+  set_option(opt_idx, varp, optval_copy(value), opt_flags, set_sid, true, true, errbuf,
+             sizeof(errbuf));
+}
+
+/// Set option value directly for buffer / window, without processing any side effects.
+///
+/// @param      opt_idx    Option index in options[] table.
+/// @param      value      Option value.
+/// @param      opt_flags  Option flags.
+/// @param      set_sid    Script ID. Special values:
+///                          0: Use current script ID.
+///                          SID_NONE: Don't set script ID.
+/// @param      req_scope  Requested option scope. See OptReqScope in option.h.
+/// @param[in]  from       Target buffer/window.
+void set_option_direct_for(OptIndex opt_idx, OptVal value, int opt_flags, scid_T set_sid,
+                           OptReqScope req_scope, void *const from)
+{
+  buf_T *save_curbuf = curbuf;
+  win_T *save_curwin = curwin;
+
+  // Don't use switch_option_context(), as that calls aucmd_prepbuf(), which may have unintended
+  // side-effects when setting an option directly. Just change the values of curbuf and curwin if
+  // needed, no need to properly switch the window / buffer.
+  switch (req_scope) {
+  case kOptReqGlobal:
+    break;
+  case kOptReqBuf:
+    curbuf = (buf_T *)from;
+    break;
+  case kOptReqWin:
+    curwin = (win_T *)from;
+    curbuf = curwin->w_buffer;
+    break;
+  }
+
+  set_option_direct(opt_idx, value, opt_flags, set_sid);
+
+  curwin = save_curwin;
+  curbuf = save_curbuf;
+}
+
 /// Set the value of an option.
 ///
 /// @param      opt_idx    Index in options[] table. Must not be kOptInvalid.
@@ -6244,7 +6305,7 @@ void set_fileformat(int eol_style, int opt_flags)
 
   // p is NULL if "eol_style" is EOL_UNKNOWN.
   if (p != NULL) {
-    set_string_option_direct(kOptFileformat, p, opt_flags, 0);
+    set_option_direct(kOptFileformat, CSTR_AS_OPTVAL(p), opt_flags, 0);
   }
 
   // This may cause the buffer to become (un)modified.
diff --git a/src/nvim/optionstr.c b/src/nvim/optionstr.c
index f80926726a..29433ddbb5 100644
--- a/src/nvim/optionstr.c
+++ b/src/nvim/optionstr.c
@@ -266,113 +266,6 @@ void check_string_option(char **pp)
   }
 }
 
-/// Set global value for string option when it's a local option.
-///
-/// @param opt  option
-/// @param varp  pointer to option variable
-static void set_string_option_global(vimoption_T *opt, char **varp)
-{
-  char **p;
-
-  // the global value is always allocated
-  if (opt->var == VAR_WIN) {
-    p = (char **)GLOBAL_WO(varp);
-  } else {
-    p = (char **)opt->var;
-  }
-  if (opt->indir != PV_NONE && p != varp) {
-    char *s = xstrdup(*varp);
-    free_string_option(*p);
-    *p = s;
-  }
-}
-
-/// Set a string option to a new value (without checking the effect).
-/// The string is copied into allocated memory.
-/// if ("opt_idx" == kOptInvalid) "name" is used, otherwise "opt_idx" is used.
-/// When "set_sid" is zero set the scriptID to current_sctx.sc_sid.  When
-/// "set_sid" is SID_NONE don't set the scriptID.  Otherwise set the scriptID to
-/// "set_sid".
-///
-/// @param  opt_flags  Option flags.
-///
-/// TODO(famiu): Remove this and its win/buf variants.
-void set_string_option_direct(OptIndex opt_idx, const char *val, int opt_flags, scid_T set_sid)
-{
-  vimoption_T *opt = get_option(opt_idx);
-
-  if (opt->var == NULL) {  // can't set hidden option
-    return;
-  }
-
-  assert(opt->var != &p_shada);
-
-  bool both = (opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0;
-  char *s = xstrdup(val);
-  char **varp = (char **)get_varp_scope(opt, both ? OPT_LOCAL : opt_flags);
-
-  if (opt->flags & P_ALLOCED) {
-    free_string_option(*varp);
-  }
-  *varp = s;
-
-  // For buffer/window local option may also set the global value.
-  if (both) {
-    set_string_option_global(opt, varp);
-  }
-
-  opt->flags |= P_ALLOCED;
-
-  // When setting both values of a global option with a local value,
-  // make the local value empty, so that the global value is used.
-  if ((opt->indir & PV_BOTH) && both) {
-    free_string_option(*varp);
-    *varp = empty_string_option;
-  }
-  if (set_sid != SID_NONE) {
-    sctx_T script_ctx;
-
-    if (set_sid == 0) {
-      script_ctx = current_sctx;
-    } else {
-      script_ctx.sc_sid = set_sid;
-      script_ctx.sc_seq = 0;
-      script_ctx.sc_lnum = 0;
-    }
-    set_option_sctx(opt_idx, opt_flags, script_ctx);
-  }
-}
-
-/// Like set_string_option_direct(), but for a window-local option in "wp".
-/// Blocks autocommands to avoid the old curwin becoming invalid.
-void set_string_option_direct_in_win(win_T *wp, OptIndex opt_idx, const char *val, int opt_flags,
-                                     int set_sid)
-{
-  win_T *save_curwin = curwin;
-
-  block_autocmds();
-  curwin = wp;
-  curbuf = curwin->w_buffer;
-  set_string_option_direct(opt_idx, val, opt_flags, set_sid);
-  curwin = save_curwin;
-  curbuf = curwin->w_buffer;
-  unblock_autocmds();
-}
-
-/// Like set_string_option_direct(), but for a buffer-local option in "buf".
-/// Blocks autocommands to avoid the old curwin becoming invalid.
-void set_string_option_direct_in_buf(buf_T *buf, OptIndex opt_idx, const char *val, int opt_flags,
-                                     int set_sid)
-{
-  buf_T *save_curbuf = curbuf;
-
-  block_autocmds();
-  curbuf = buf;
-  set_string_option_direct(opt_idx, val, opt_flags, set_sid);
-  curbuf = save_curbuf;
-  unblock_autocmds();
-}
-
 /// Return true if "val" is a valid 'filetype' name.
 /// Also used for 'syntax' and 'keymap'.
 static bool valid_filetype(const char *val)
diff --git a/src/nvim/popupmenu.c b/src/nvim/popupmenu.c
index 5e8fb7f5de..bed0a8df4a 100644
--- a/src/nvim/popupmenu.c
+++ b/src/nvim/popupmenu.c
@@ -704,7 +704,8 @@ static win_T *pum_create_float_preview(bool enter)
     return NULL;
   }
   buf_T *buf = find_buffer_by_handle(b, &err);
-  set_string_option_direct_in_buf(buf, kOptBufhidden, "wipe", OPT_LOCAL, 0);
+  set_option_direct_for(kOptBufhidden, STATIC_CSTR_AS_OPTVAL("wipe"), OPT_LOCAL, 0, kOptReqBuf,
+                        buf);
   wp->w_float_is_info = true;
   wp->w_p_diff = false;
   buf->b_p_bl = false;
diff --git a/src/nvim/quickfix.c b/src/nvim/quickfix.c
index 0f639bf86a..9f431556e8 100644
--- a/src/nvim/quickfix.c
+++ b/src/nvim/quickfix.c
@@ -5154,7 +5154,7 @@ void ex_cfile(exarg_T *eap)
     }
   }
   if (*eap->arg != NUL) {
-    set_string_option_direct(kOptErrorfile, eap->arg, 0, 0);
+    set_option_direct(kOptErrorfile, CSTR_AS_OPTVAL(eap->arg), 0, 0);
   }
 
   char *enc = (*curbuf->b_p_menc != NUL) ? curbuf->b_p_menc : p_menc;
diff --git a/src/nvim/statusline.c b/src/nvim/statusline.c
index 1d914dd105..ca7083a9e3 100644
--- a/src/nvim/statusline.c
+++ b/src/nvim/statusline.c
@@ -2187,7 +2187,7 @@ int build_stl_str_hl(win_T *wp, char *out, size_t outlen, char *fmt, OptIndex op
   // matter?
   // if (called_emsg > called_emsg_before)
   if (opt_idx != kOptInvalid && did_emsg > did_emsg_before) {
-    set_string_option_direct(opt_idx, "", opt_scope, SID_ERROR);
+    set_option_direct(opt_idx, STATIC_CSTR_AS_OPTVAL(""), opt_scope, SID_ERROR);
   }
 
   // A user function may reset KeyTyped, restore it.