refactor: reorganize option header files (#25437)

- Move vimoption_T to option.h
- option_defs.h is for option-related types
- option_vars.h corresponds to Vim's option.h
- option_defs.h and option_vars.h don't include each other

src/nvim/option.h

@@ -1,15 +1,95 @@
 #ifndef NVIM_OPTION_H
 #define NVIM_OPTION_H
 
+#include <stdint.h>
+
 #include "nvim/api/private/helpers.h"
+#include "nvim/eval/typval_defs.h"
 #include "nvim/ex_cmds_defs.h"
+#include "nvim/option_defs.h"
 
-// flags for buf_copy_options()
-#define BCO_ENTER       1       // going to enter the buffer
-#define BCO_ALWAYS      2       // always copy the options
-#define BCO_NOHELP      4       // don't touch the help related options
+/// 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.
+enum {
+  PV_BOTH = 0x1000,
+  PV_WIN  = 0x2000,
+  PV_BUF  = 0x4000,
+  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))
 
-#define MAX_NUMBERWIDTH 20      // used for 'numberwidth' and 'statuscolumn'
+/// 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 *)-1)
+
+typedef struct vimoption {
+  char *fullname;    ///< full option name
+  char *shortname;   ///< permissible abbreviation
+  uint32_t flags;    ///< see above
+  void *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
+                     ///< callback function to invoke after an option is modified to validate and
+                     ///< apply the new value.
+  opt_did_set_cb_T opt_did_set_cb;
+  void *def_val;     ///< default values for variable (neovim!!)
+  LastSet last_set;  ///< script in which the option was last set
+} vimoption_T;
+
+/// flags for buf_copy_options()
+enum {
+  BCO_ENTER  = 1,  ///< going to enter the buffer
+  BCO_ALWAYS = 2,  ///< always copy the options
+  BCO_NOHELP = 4,  ///< don't touch the help related options
+};
+
+/// Flags for option-setting functions
+///
+/// When OPT_GLOBAL and OPT_LOCAL are both missing, set both local and global
+/// values, get local value.
+typedef enum {
+  OPT_FREE      = 0x01,   ///< Free old value if it was allocated.
+  OPT_GLOBAL    = 0x02,   ///< Use global value.
+  OPT_LOCAL     = 0x04,   ///< Use local value.
+  OPT_MODELINE  = 0x08,   ///< Option in modeline.
+  OPT_WINONLY   = 0x10,   ///< Only set window-local options.
+  OPT_NOWIN     = 0x20,   ///< Don’t set window-local options.
+  OPT_ONECOLUMN = 0x40,   ///< list options one per line
+  OPT_NO_REDRAW = 0x80,   ///< ignore redraw flags on option
+  OPT_SKIPRTP   = 0x100,  ///< "skiprtp" in 'sessionoptions'
+} OptionFlags;
+
+/// Return value from get_option_value_strict
+enum {
+  SOPT_BOOL   = 0x01,  ///< Boolean option
+  SOPT_NUM    = 0x02,  ///< Number option
+  SOPT_STRING = 0x04,  ///< String option
+  SOPT_GLOBAL = 0x08,  ///< Option has global value
+  SOPT_WIN    = 0x10,  ///< Option has window-local value
+  SOPT_BUF    = 0x20,  ///< Option has buffer-local value
+  SOPT_UNSET  = 0x40,  ///< Option does not have local value set
+};
+
+/// Option types for various functions in option.c
+enum {
+  SREQ_GLOBAL = 0,  ///< Request global option value
+  SREQ_WIN    = 1,  ///< Request window-local option value
+  SREQ_BUF    = 2,  ///< Request buffer-local option value
+};
 
 // OptVal helper macros.
 #define NIL_OPTVAL ((OptVal) { .type = kOptValTypeNil })