shada: Move shada file to a new location

src/nvim/main.c

@@ -2028,7 +2028,7 @@ static void usage(void)
   mch_msg(_("  -r, -L                List swap files and exit\n"));
   mch_msg(_("  -r <file>             Recover crashed session\n"));
   mch_msg(_("  -u <nvimrc>           Use <nvimrc> instead of the default\n"));
-  mch_msg(_("  -i <shada>            Use <shada> instead of the default " SHADA_FILE "\n"));  // NOLINT(whitespace/line_length)
+  mch_msg(_("  -i <shada>            Use <shada> instead of the default\n"));
   mch_msg(_("  --noplugin            Don't load plugin scripts\n"));
   mch_msg(_("  -o[N]                 Open N windows (default: one for each file)\n"));
   mch_msg(_("  -O[N]                 Like -o but split vertically\n"));

src/nvim/os/unix_defs.h

@@ -37,8 +37,5 @@
 #ifndef VIMRC_FILE
 # define VIMRC_FILE     ".nvimrc"
 #endif
-#ifndef SHADA_FILE
-# define SHADA_FILE "~/.nvim/shada/main.shada"
-#endif
 
 #endif  // NVIM_OS_UNIX_DEFS_H

src/nvim/os/win_defs.h

@@ -8,7 +8,6 @@
 
 // Defines needed to fix the build on Windows:
 // - USR_EXRC_FILE
-// - SHADA_FILE
 // - DFLT_DIR
 // - DFLT_BDIR
 // - DFLT_VDIR

src/nvim/shada.c

@@ -1583,6 +1583,20 @@ shada_read_main_cycle_end:
   kh_dealloc(strset, &oldfiles_set);
 }
 
+/// Default shada file location: cached path
+static char *default_shada_file = NULL;
+
+/// Get the default ShaDa file
+static const char *shada_get_default_file(void)
+  FUNC_ATTR_WARN_UNUSED_RESULT
+{
+  if (default_shada_file == NULL) {
+    char *shada_dir = stdpaths_user_data_subpath("shada");
+    default_shada_file = concat_fnames_realloc(shada_dir, "main.shada", true);
+  }
+  return default_shada_file;
+}
+
 /// Get the ShaDa file name to use
 ///
 /// If "file" is given and not empty, use it (has already been expanded by
@@ -1608,11 +1622,11 @@ static char *shada_filename(const char *file)
           if (STRCMP("$VIM", NameBuff) != 0) {  // $VIM was expanded
             file = SHADA_FILE2;
           } else {
-            file = SHADA_FILE;
+            file = shada_get_default_file();
           }
         } else {
 #endif
-          file =  SHADA_FILE;
+          file =  shada_get_default_file();
 #ifdef SHADA_FILE2
         }
 #endif