refactor: replace unnecessary helper functions in optionstr.c

Replaces unnecessary helper functions in `optionstr.c` such as
`get_option_flags()`, `get_option_fullname()`, `set_option_flag()`,
`is_global_option()`, etc. with a single `get_option()` helper function
that allows direct access to the `options` array.

Also refactors `f_exists()` to use `get_varp_scope` instead of using
`get_option_tv`. This opens up the path for removing `getoptions_T`
altogether later down the line since the hidden option logic is no
longer needed.

5 files changed, 89 insertions, 141 deletions

diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index c2a7b6bba5..6eaf3d1f5e 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -3659,7 +3659,6 @@ static int eval_index(char **arg, typval_T *rettv, int evaluate, int verbose)
 int get_option_tv(const char **const arg, typval_T *const rettv, const bool evaluate)
   FUNC_ATTR_NONNULL_ARG(1)
 {
-  bool working = (**arg == '+');  // has("+option")
   int opt_flags;
 
   // Isolate the option name and find its value.
@@ -3704,10 +3703,6 @@ int get_option_tv(const char **const arg, typval_T *const rettv, const bool eval
       rettv->v_type = VAR_STRING;
       rettv->vval.v_string = stringval;
     }
-  } else if (working && (opt_type == gov_hidden_bool
-                         || opt_type == gov_hidden_number
-                         || opt_type == gov_hidden_string)) {
-    ret = FAIL;
   }
 
   *option_end = c;                  // put back for error messages
diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index 9ba2ce2365..f2ef8e5cdd 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -1938,9 +1938,14 @@ static void f_exists(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
       xfree(exp);
     }
   } else if (*p == '&' || *p == '+') {  // Option.
-    n = (get_option_tv(&p, NULL, true) == OK);
-    if (*skipwhite(p) != NUL) {
-      n = false;  // Trailing garbage.
+    bool working = (*p == '+');  // whether option needs to be working
+    int opt_flags;
+
+    if (find_option_end(&p, &opt_flags) != NULL) {
+      int opt_idx = findoption(p);
+      n = (opt_idx >= 0 && (!working || get_varp_scope(get_option(opt_idx), opt_flags) != NULL));
+    } else {
+      n = false;
     }
   } else if (*p == '*') {  // Internal or user defined function.
     n = function_exists(p + 1, false);
diff --git a/src/nvim/option.c b/src/nvim/option.c
index 5b67f0e471..e7d0b171f6 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -106,30 +106,6 @@ static char e_number_required_after_equal[]
 static char e_preview_window_already_exists[]
   = N_("E590: A preview window already exists");
 
-// The options that are local to a window or buffer have "indir" set to one of
-// these values.  Special values:
-// PV_NONE: global option.
-// PV_WIN is added: window-local option
-// PV_BUF is added: buffer-local option
-// PV_BOTH is added: global option which also has a local value.
-#define PV_BOTH 0x1000
-#define PV_WIN  0x2000
-#define PV_BUF  0x4000
-#define PV_MASK 0x0fff
-#define OPT_WIN(x)  (idopt_T)(PV_WIN + (int)(x))
-#define OPT_BUF(x)  (idopt_T)(PV_BUF + (int)(x))
-#define OPT_BOTH(x) (idopt_T)(PV_BOTH + (int)(x))
-
-// WV_ and BV_ values get typecasted to this for the "indir" field
-typedef enum {
-  PV_NONE = 0,
-  PV_MAXVAL = 0xffff,  // to avoid warnings for value out of range
-} idopt_T;
-
-// Options local to a window have a value local to a buffer and global to all
-// buffers.  Indicate this by setting "var" to VAR_WIN.
-#define VAR_WIN ((char_u *)-1)
-
 static char *p_term = NULL;
 static char *p_ttytype = NULL;
 
@@ -147,19 +123,6 @@ static long p_tw_nopaste;
 static long p_wm_nopaste;
 static char *p_vsts_nopaste;
 
-typedef struct vimoption {
-  char *fullname;        // full option name
-  char *shortname;       // permissible abbreviation
-  uint32_t flags;               // see below
-  char_u *var;             // global option: pointer to variable;
-                           // window-local option: VAR_WIN;
-                           // buffer-local option: global value
-  idopt_T indir;                // global option: PV_NONE;
-                                // local option: indirect option index
-  char *def_val;         // default values for variable (neovim!!)
-  LastSet last_set;             // script in which the option was last set
-} vimoption_T;
-
 // 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()).
@@ -3047,47 +3010,10 @@ int get_option_value_strict(char *name, int64_t *numval, char **stringval, int o
   return rv;
 }
 
-/// Return the flags for the option at 'opt_idx'.
-uint32_t get_option_flags(int opt_idx)
-{
-  return options[opt_idx].flags;
-}
-
-/// Set a flag for the option at 'opt_idx'.
-void set_option_flag(int opt_idx, uint32_t flag)
-{
-  options[opt_idx].flags |= flag;
-}
-
-/// Clear a flag for the option at 'opt_idx'.
-void clear_option_flag(int opt_idx, uint32_t flag)
-{
-  options[opt_idx].flags &= ~flag;
-}
-
-/// Returns true if the option at 'opt_idx' is a global option
-bool is_global_option(int opt_idx)
-{
-  return options[opt_idx].indir == PV_NONE;
-}
-
-/// Returns true if the option at 'opt_idx' is a global option which also has a
-/// local value.
-int is_global_local_option(int opt_idx)
+// Return information for option at 'opt_idx'
+vimoption_T *get_option(int opt_idx)
 {
-  return options[opt_idx].indir & PV_BOTH;
-}
-
-/// Returns true if the option at 'opt_idx' is a window-local option
-bool is_window_local_option(int opt_idx)
-{
-  return options[opt_idx].var == VAR_WIN;
-}
-
-/// Returns true if the option at 'opt_idx' is a hidden option
-bool is_hidden_option(int opt_idx)
-{
-  return options[opt_idx].var == NULL;
+  return &options[opt_idx];
 }
 
 /// Set the value of an option
@@ -3761,7 +3687,7 @@ void unset_global_local_option(char *name, void *from)
 }
 
 /// Get pointer to option variable, depending on local or global scope.
-static char *get_varp_scope(vimoption_T *p, int opt_flags)
+char *get_varp_scope(vimoption_T *p, int opt_flags)
 {
   if ((opt_flags & OPT_GLOBAL) && p->indir != PV_NONE) {
     if (p->var == VAR_WIN) {
@@ -3833,13 +3759,6 @@ static char *get_varp_scope(vimoption_T *p, int opt_flags)
   return (char *)get_varp(p);
 }
 
-/// Get pointer to option variable at 'opt_idx', depending on local or global
-/// scope.
-char *get_option_varp_scope(int opt_idx, int opt_flags)
-{
-  return get_varp_scope(&(options[opt_idx]), opt_flags);
-}
-
 /// Get pointer to option variable.
 static char_u *get_varp(vimoption_T *p)
 {
@@ -4149,18 +4068,6 @@ static char_u *get_varp(vimoption_T *p)
   return (char_u *)&(curbuf->b_p_wm);
 }
 
-/// Return a pointer to the variable for option at 'opt_idx'
-char_u *get_option_var(int opt_idx)
-{
-  return options[opt_idx].var;
-}
-
-/// Return the full name of the option at 'opt_idx'
-char *get_option_fullname(int opt_idx)
-{
-  return options[opt_idx].fullname;
-}
-
 /// Get the value of 'equalprg', either the buffer-local one or the global one.
 char_u *get_equalprg(void)
 {
diff --git a/src/nvim/option_defs.h b/src/nvim/option_defs.h
index e8cf338cf1..e27607d7a8 100644
--- a/src/nvim/option_defs.h
+++ b/src/nvim/option_defs.h
@@ -990,4 +990,41 @@ typedef struct {
   uint64_t channel_id;     /// Only used when script_id is SID_API_CLIENT.
 } LastSet;
 
+// WV_ and BV_ values get typecasted to this for the "indir" field
+typedef enum {
+  PV_NONE = 0,
+  PV_MAXVAL = 0xffff,  // to avoid warnings for value out of range
+} idopt_T;
+
+typedef struct vimoption {
+  char *fullname;        // full option name
+  char *shortname;       // permissible abbreviation
+  uint32_t flags;               // see below
+  char_u *var;             // global option: pointer to variable;
+                           // window-local option: VAR_WIN;
+                           // buffer-local option: global value
+  idopt_T indir;                // global option: PV_NONE;
+                                // local option: indirect option index
+  char *def_val;         // default values for variable (neovim!!)
+  LastSet last_set;             // script in which the option was last set
+} vimoption_T;
+
+// The options that are local to a window or buffer have "indir" set to one of
+// these values.  Special values:
+// PV_NONE: global option.
+// PV_WIN is added: window-local option
+// PV_BUF is added: buffer-local option
+// PV_BOTH is added: global option which also has a local value.
+#define PV_BOTH 0x1000
+#define PV_WIN  0x2000
+#define PV_BUF  0x4000
+#define PV_MASK 0x0fff
+#define OPT_WIN(x)  (idopt_T)(PV_WIN + (int)(x))
+#define OPT_BUF(x)  (idopt_T)(PV_BUF + (int)(x))
+#define OPT_BOTH(x) (idopt_T)(PV_BOTH + (int)(x))
+
+// Options local to a window have a value local to a buffer and global to all
+// buffers.  Indicate this by setting "var" to VAR_WIN.
+#define VAR_WIN ((char_u *)-1)
+
 #endif  // NVIM_OPTION_DEFS_H
diff --git a/src/nvim/optionstr.c b/src/nvim/optionstr.c
index 7278b1a12d..aff88a755b 100644
--- a/src/nvim/optionstr.c
+++ b/src/nvim/optionstr.c
@@ -178,7 +178,7 @@ void trigger_optionsset_string(int opt_idx, int opt_flags, char *oldval, char *o
       set_vim_var_string(VV_OPTION_COMMAND, "modeline", -1);
       set_vim_var_string(VV_OPTION_OLDLOCAL, oldval, -1);
     }
-    apply_autocmds(EVENT_OPTIONSET, get_option_fullname(opt_idx), NULL, false, NULL);
+    apply_autocmds(EVENT_OPTIONSET, get_option(opt_idx)->fullname, NULL, false, NULL);
     reset_v_option_vars();
   }
 }
@@ -280,19 +280,19 @@ void check_string_option(char **pp)
 
 /// Set global value for string option when it's a local option.
 ///
-/// @param opt_idx  option index
+/// @param opt  option
 /// @param varp  pointer to option variable
-static void set_string_option_global(int opt_idx, char **varp)
+static void set_string_option_global(vimoption_T *opt, char **varp)
 {
   char **p;
 
   // the global value is always allocated
-  if (is_window_local_option(opt_idx)) {
+  if (opt->var == VAR_WIN) {
     p = (char **)GLOBAL_WO(varp);
   } else {
-    p = (char **)get_option_var(opt_idx);
+    p = (char **)opt->var;
   }
-  if (!is_global_option(opt_idx) && p != varp) {
+  if (opt->indir != PV_NONE && p != varp) {
     char *s = xstrdup(*varp);
     free_string_option(*p);
     *p = s;
@@ -324,30 +324,32 @@ void set_string_option_direct(const char *name, int opt_idx, const char *val, in
     }
   }
 
-  if (is_hidden_option(idx)) {       // can't set hidden option
+  vimoption_T *opt = get_option(idx);
+
+  if (opt->var == NULL) {  // can't set hidden option
     return;
   }
 
-  assert((void *)get_option_var(idx) != (void *)&p_shada);
+  assert((void *)opt->var != (void *)&p_shada);
 
   s = xstrdup(val);
   {
-    varp = (char **)get_option_varp_scope(idx, both ? OPT_LOCAL : opt_flags);
-    if ((opt_flags & OPT_FREE) && (get_option_flags(idx) & P_ALLOCED)) {
+    varp = (char **)get_varp_scope(opt, both ? OPT_LOCAL : opt_flags);
+    if ((opt_flags & OPT_FREE) && (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(idx, varp);
+      set_string_option_global(opt, varp);
     }
 
-    set_option_flag(idx, P_ALLOCED);
+    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 (is_global_local_option(idx) && both) {
+    if ((opt->indir & PV_BOTH) && both) {
       free_string_option(*varp);
       *varp = empty_option;
     }
@@ -393,24 +395,24 @@ void set_string_option_direct_in_win(win_T *wp, const char *name, int opt_idx, c
 char *set_string_option(const int opt_idx, const char *const value, const int opt_flags)
   FUNC_ATTR_NONNULL_ARG(2) FUNC_ATTR_WARN_UNUSED_RESULT
 {
-  if (is_hidden_option(opt_idx)) {  // don't set hidden option
+  vimoption_T *opt = get_option(opt_idx);
+
+  if (opt->var == NULL) {  // don't set hidden option
     return NULL;
   }
 
   char *const s = xstrdup(value);
   char **const varp
-    = (char **)get_option_varp_scope(opt_idx,
-                                     (opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0
-                                     ? (is_global_local_option(opt_idx)
-                                        ? OPT_GLOBAL : OPT_LOCAL)
-                                     : opt_flags);
+    = (char **)get_varp_scope(opt, ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0
+                                    ? ((opt->indir & PV_BOTH) ? OPT_GLOBAL : OPT_LOCAL)
+                                    : opt_flags));
   char *const oldval = *varp;
   char *oldval_l = NULL;
   char *oldval_g = NULL;
 
   if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0) {
-    oldval_l = *(char **)get_option_varp_scope(opt_idx, OPT_LOCAL);
-    oldval_g = *(char **)get_option_varp_scope(opt_idx, OPT_GLOBAL);
+    oldval_l = *(char **)get_varp_scope(opt, OPT_LOCAL);
+    oldval_g = *(char **)get_varp_scope(opt, OPT_GLOBAL);
   }
 
   *varp = s;
@@ -434,8 +436,8 @@ char *set_string_option(const int opt_idx, const char *const value, const int op
       trigger_optionsset_string(opt_idx, opt_flags, saved_oldval, saved_oldval_l, saved_oldval_g,
                                 saved_newval);
     }
-    if (get_option_flags(opt_idx) & P_UI_OPTION) {
-      ui_call_option_set(cstr_as_string(get_option_fullname(opt_idx)),
+    if (opt->flags & P_UI_OPTION) {
+      ui_call_option_set(cstr_as_string(opt->fullname),
                          STRING_OBJ(cstr_as_string(saved_newval)));
     }
   }
@@ -638,20 +640,21 @@ char *did_set_string_option(int opt_idx, char **varp, char *oldval, char *errbuf
   char *errmsg = NULL;
   char *s, *p;
   int did_chartab = false;
-  bool free_oldval = (get_option_flags(opt_idx) & P_ALLOCED);
+  vimoption_T *opt = get_option(opt_idx);
+  bool free_oldval = (opt->flags & P_ALLOCED);
   bool value_changed = false;
 
   // Get the global option to compare with, otherwise we would have to check
   // two values for all local options.
-  char **gvarp = (char **)get_option_varp_scope(opt_idx, OPT_GLOBAL);
+  char **gvarp = (char **)get_varp_scope(opt, OPT_GLOBAL);
 
   // Disallow changing some options from secure mode
   if ((secure || sandbox != 0)
-      && (get_option_flags(opt_idx) & P_SECURE)) {
+      && (opt->flags & P_SECURE)) {
     errmsg = e_secure;
-  } else if (((get_option_flags(opt_idx) & P_NFNAME)
+  } else if (((opt->flags & P_NFNAME)
               && strpbrk(*varp, (secure ? "/\\*?[|;&<>\r\n" : "/\\*?[<>\r\n")) != NULL)
-             || ((get_option_flags(opt_idx) & P_NDNAME)
+             || ((opt->flags & P_NDNAME)
                  && strpbrk(*varp, "*?[|;&<>\r\n") != NULL)) {
     // Check for a "normal" directory or file name in some options.  Disallow a
     // path separator (slash and/or backslash), wildcards and characters that
@@ -986,13 +989,14 @@ char *did_set_string_option(int opt_idx, char **varp, char *oldval, char *errbuf
   } else if (varp == &p_shada) {  // 'shada'
     // TODO(ZyX-I): Remove this code in the future, alongside with &viminfo
     //              option.
-    opt_idx = ((get_option_fullname(opt_idx)[0] == 'v')
+    opt_idx = ((opt->fullname[0] == 'v')
                ? (shada_idx == -1 ? ((shada_idx = findoption("shada"))) : shada_idx)
                : opt_idx);
+    opt = get_option(opt_idx);
     // Update free_oldval now that we have the opt_idx for 'shada', otherwise
     // there would be a disconnect between the check for P_ALLOCED at the start
     // of the function and the set of P_ALLOCED at the end of the function.
-    free_oldval = (get_option_flags(opt_idx) & P_ALLOCED);
+    free_oldval = (opt->flags & P_ALLOCED);
     for (s = p_shada; *s;) {
       // Check it's a valid character
       if (vim_strchr("!\"%'/:<@cfhnrs", *s) == NULL) {
@@ -1522,18 +1526,18 @@ char *did_set_string_option(int opt_idx, char **varp, char *oldval, char *errbuf
     if (free_oldval) {
       free_string_option(oldval);
     }
-    set_option_flag(opt_idx, P_ALLOCED);
+    opt->flags |= P_ALLOCED;
 
     if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0
-        && is_global_local_option(opt_idx)) {
+        && (opt->indir & PV_BOTH)) {
       // global option with local value set to use global value; free
       // the local value and make it empty
-      p = get_option_varp_scope(opt_idx, OPT_LOCAL);
+      p = get_varp_scope(opt, OPT_LOCAL);
       free_string_option(*(char **)p);
       *(char **)p = empty_option;
     } else if (!(opt_flags & OPT_LOCAL) && opt_flags != OPT_GLOBAL) {
       // May set global value for local option.
-      set_string_option_global(opt_idx, varp);
+      set_string_option_global(opt, varp);
     }
 
     // Trigger the autocommand only after setting the flags.
@@ -1604,11 +1608,11 @@ char *did_set_string_option(int opt_idx, char **varp, char *oldval, char *errbuf
   }
 
   if (curwin->w_curswant != MAXCOL
-      && (get_option_flags(opt_idx) & (P_CURSWANT | P_RALL)) != 0) {
+      && (opt->flags & (P_CURSWANT | P_RALL)) != 0) {
     curwin->w_set_curswant = true;
   }
 
-  check_redraw(get_option_flags(opt_idx));
+  check_redraw(opt->flags);
 
   return errmsg;
 }