refactor: replace char_u with char 18 (#21237)

refactor: replace char_u with char

Work on https://github.com/neovim/neovim/issues/459

45 files changed, 451 insertions, 451 deletions

diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index 58abec351b..e6d0dcb8cf 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -1089,7 +1089,7 @@ char *do_bufdel(int command, char *arg, int addr_count, int start_bnr, int end_b
       } else {
         STRCPY(IObuff, _("E517: No buffers were wiped out"));
       }
-      errormsg = (char *)IObuff;
+      errormsg = IObuff;
     } else if (deleted >= p_report) {
       if (command == DOBUF_UNLOAD) {
         smsg(NGETTEXT("%d buffer unloaded", "%d buffers unloaded", deleted),
@@ -2762,7 +2762,7 @@ void buflist_list(exarg_T *eap)
     if (buf_spname(buf) != NULL) {
       xstrlcpy(NameBuff, buf_spname(buf), MAXPATHL);
     } else {
-      home_replace(buf, buf->b_fname, (char *)NameBuff, MAXPATHL, true);
+      home_replace(buf, buf->b_fname, NameBuff, MAXPATHL, true);
     }
 
     if (message_filtered(NameBuff)) {
@@ -2778,7 +2778,7 @@ void buflist_list(exarg_T *eap)
     }
 
     msg_putchar('\n');
-    len = vim_snprintf((char *)IObuff, IOSIZE - 20, "%3d%c%c%c%c%c \"%s\"",
+    len = vim_snprintf(IObuff, IOSIZE - 20, "%3d%c%c%c%c%c \"%s\"",
                        buf->b_fnum,
                        buf->b_p_bl ? ' ' : 'u',
                        buf == curbuf ? '%' : (curwin->w_alt_fnum == buf->b_fnum ? '#' : ' '),
@@ -2792,18 +2792,18 @@ void buflist_list(exarg_T *eap)
     }
 
     // put "line 999" in column 40 or after the file name
-    i = 40 - vim_strsize((char *)IObuff);
+    i = 40 - vim_strsize(IObuff);
     do {
       IObuff[len++] = ' ';
     } while (--i > 0 && len < IOSIZE - 18);
     if (vim_strchr(eap->arg, 't') && buf->b_last_used) {
-      undo_fmt_time((char_u *)IObuff + len, (size_t)(IOSIZE - len), buf->b_last_used);
+      undo_fmt_time(IObuff + len, (size_t)(IOSIZE - len), buf->b_last_used);
     } else {
-      vim_snprintf((char *)IObuff + len, (size_t)(IOSIZE - len), _("line %" PRId64),
+      vim_snprintf(IObuff + len, (size_t)(IOSIZE - len), _("line %" PRId64),
                    buf == curbuf ? (int64_t)curwin->w_cursor.lnum : (int64_t)buflist_findlnum(buf));
     }
 
-    msg_outtrans((char *)IObuff);
+    msg_outtrans(IObuff);
     line_breakcheck();
   }
 
diff --git a/src/nvim/channel.c b/src/nvim/channel.c
index 386ec832eb..65bb87bc2c 100644
--- a/src/nvim/channel.c
+++ b/src/nvim/channel.c
@@ -215,7 +215,7 @@ void channel_create_event(Channel *chan, const char *ext_source)
     // external events should be included.
     source = ext_source;
   } else {
-    eval_fmt_source_name_line((char *)IObuff, sizeof(IObuff));
+    eval_fmt_source_name_line(IObuff, sizeof(IObuff));
     source = (const char *)IObuff;
   }
 
diff --git a/src/nvim/charset.c b/src/nvim/charset.c
index 51ea7f3205..4115743e1c 100644
--- a/src/nvim/charset.c
+++ b/src/nvim/charset.c
@@ -439,7 +439,7 @@ size_t kv_transstr(StringBuilder *str, const char *const s, bool untab)
 ///
 /// When "buf" is NULL, return an allocated string.
 /// Otherwise, put the result in buf, limited by buflen, and return buf.
-char_u *str_foldcase(char_u *str, int orglen, char *buf, int buflen)
+char *str_foldcase(char *str, int orglen, char *buf, int buflen)
   FUNC_ATTR_NONNULL_RET
 {
   garray_T ga;
@@ -518,9 +518,9 @@ char_u *str_foldcase(char_u *str, int orglen, char *buf, int buflen)
   }
 
   if (buf == NULL) {
-    return (char_u *)ga.ga_data;
+    return ga.ga_data;
   }
-  return (char_u *)buf;
+  return buf;
 }
 
 // Catch 22: g_chartab[] can't be initialized before the options are
@@ -809,10 +809,10 @@ bool vim_iswordc_buf(const int c, buf_T *const buf)
 /// @param  p  pointer to the multi-byte character
 ///
 /// @return true if "p" points to a keyword character.
-bool vim_iswordp(const char_u *const p)
+bool vim_iswordp(const char *const p)
   FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_NONNULL_ALL
 {
-  return vim_iswordp_buf((char *)p, curbuf);
+  return vim_iswordp_buf(p, curbuf);
 }
 
 /// Just like vim_iswordc_buf() but uses a pointer to the (multi-byte)
diff --git a/src/nvim/cmdexpand.c b/src/nvim/cmdexpand.c
index a1030389a9..761e915131 100644
--- a/src/nvim/cmdexpand.c
+++ b/src/nvim/cmdexpand.c
@@ -107,7 +107,7 @@ static int sort_func_compare(const void *s1, const void *s2)
 static void ExpandEscape(expand_T *xp, char_u *str, int numfiles, char **files, int options)
 {
   int i;
-  char_u *p;
+  char *p;
   const int vse_what = xp->xp_context == EXPAND_BUFFERS ? VSE_BUFFER : VSE_NONE;
 
   // May change home directory back to "~"
@@ -126,9 +126,9 @@ static void ExpandEscape(expand_T *xp, char_u *str, int numfiles, char **files,
       for (i = 0; i < numfiles; i++) {
         // for ":set path=" we need to escape spaces twice
         if (xp->xp_backslash == XP_BS_THREE) {
-          p = vim_strsave_escaped((char_u *)files[i], (char_u *)" ");
+          p = (char *)vim_strsave_escaped((char_u *)files[i], (char_u *)" ");
           xfree(files[i]);
-          files[i] = (char *)p;
+          files[i] = p;
 #if defined(BACKSLASH_IN_FILENAME)
           p = vim_strsave_escaped(files[i], (char_u *)" ");
           xfree(files[i]);
@@ -136,13 +136,13 @@ static void ExpandEscape(expand_T *xp, char_u *str, int numfiles, char **files,
 #endif
         }
 #ifdef BACKSLASH_IN_FILENAME
-        p = (char_u *)vim_strsave_fnameescape((const char *)files[i], vse_what);
+        p = vim_strsave_fnameescape((const char *)files[i], vse_what);
 #else
-        p = (char_u *)vim_strsave_fnameescape((const char *)files[i],
-                                              xp->xp_shell ? VSE_SHELL : vse_what);
+        p = vim_strsave_fnameescape((const char *)files[i],
+                                    xp->xp_shell ? VSE_SHELL : vse_what);
 #endif
         xfree(files[i]);
-        files[i] = (char *)p;
+        files[i] = p;
 
         // If 'str' starts with "\~", replace "~" at start of
         // files[i] with "\~".
@@ -161,9 +161,9 @@ static void ExpandEscape(expand_T *xp, char_u *str, int numfiles, char **files,
       // Insert a backslash before characters in a tag name that
       // would terminate the ":tag" command.
       for (i = 0; i < numfiles; i++) {
-        p = vim_strsave_escaped((char_u *)files[i], (char_u *)"\\|\"");
+        p = (char *)vim_strsave_escaped((char_u *)files[i], (char_u *)"\\|\"");
         xfree(files[i]);
-        files[i] = (char *)p;
+        files[i] = p;
       }
     }
   }
@@ -180,7 +180,7 @@ int nextwild(expand_T *xp, int type, int options, bool escape)
 {
   CmdlineInfo *const ccline = get_cmdline_info();
   int i, j;
-  char_u *p1;
+  char *p1;
   char *p2;
   int difflen;
 
@@ -214,14 +214,14 @@ int nextwild(expand_T *xp, int type, int options, bool escape)
     p2 = ExpandOne(xp, NULL, NULL, 0, type);
   } else {
     // Translate string into pattern and expand it.
-    p1 = (char_u *)addstar(xp->xp_pattern, xp->xp_pattern_len, xp->xp_context);
+    p1 = addstar(xp->xp_pattern, xp->xp_pattern_len, xp->xp_context);
     const int use_options = (options
                              | WILD_HOME_REPLACE
                              | WILD_ADD_SLASH
                              | WILD_SILENT
                              | (escape ? WILD_ESCAPE : 0)
                              | (p_wic ? WILD_ICASE : 0));
-    p2 = ExpandOne(xp, (char *)p1, xstrnsave(&ccline->cmdbuff[i], xp->xp_pattern_len),
+    p2 = ExpandOne(xp, p1, xstrnsave(&ccline->cmdbuff[i], xp->xp_pattern_len),
                    use_options, type);
     xfree(p1);
 
@@ -358,16 +358,16 @@ static void redraw_wildmenu(expand_T *xp, int num_matches, char **matches, int m
 {
 #define L_MATCH(m) (showtail ? showmatches_gettail(matches[m], false) : matches[m])
   int row;
-  char_u *buf;
+  char *buf;
   int len;
   int clen;                     // length in screen cells
   int fillchar;
   int attr;
   int i;
   bool highlight = true;
-  char_u *selstart = NULL;
+  char *selstart = NULL;
   int selstart_col = 0;
-  char_u *selend = NULL;
+  char *selend = NULL;
   static int first_match = 0;
   bool add_left = false;
   char *s;
@@ -450,7 +450,7 @@ static void redraw_wildmenu(expand_T *xp, int num_matches, char **matches, int m
              || xp->xp_context == EXPAND_MENUNAMES);
     if (emenu && menu_is_separator(s)) {
       STRCPY(buf + len, transchar('|'));
-      l = (int)strlen((char *)buf + len);
+      l = (int)strlen(buf + len);
       len += l;
       clen += l;
     } else {
@@ -520,10 +520,10 @@ static void redraw_wildmenu(expand_T *xp, int num_matches, char **matches, int m
     ScreenGrid *grid = (wild_menu_showing == WM_SCROLLED)
                         ? &msg_grid_adj : &default_grid;
 
-    grid_puts(grid, (char *)buf, row, 0, attr);
+    grid_puts(grid, buf, row, 0, attr);
     if (selstart != NULL && highlight) {
       *selend = NUL;
-      grid_puts(grid, (char *)selstart, row, selstart_col, HL_ATTR(HLF_WM));
+      grid_puts(grid, selstart, row, selstart_col, HL_ATTR(HLF_WM));
     }
 
     grid_fill(grid, row, row + 1, clen, Columns,
@@ -835,14 +835,14 @@ int showmatches(expand_T *xp, int wildmenu)
   int maxlen;
   int lines;
   int columns;
-  char_u *p;
+  char *p;
   int lastlen;
   int attr;
   int showtail;
 
   if (xp->xp_numfiles == -1) {
     set_expand_context(xp);
-    i = expand_cmdline(xp, (char_u *)ccline->cmdbuff, ccline->cmdpos,
+    i = expand_cmdline(xp, ccline->cmdbuff, ccline->cmdpos,
                        &num_files, &files_found);
     showtail = expand_showtail(xp);
     if (i != EXPAND_OK) {
@@ -903,8 +903,8 @@ int showmatches(expand_T *xp, int wildmenu)
       if (!showtail && (xp->xp_context == EXPAND_FILES
                         || xp->xp_context == EXPAND_SHELLCMD
                         || xp->xp_context == EXPAND_BUFFERS)) {
-        home_replace(NULL, files_found[i], (char *)NameBuff, MAXPATHL, true);
-        j = vim_strsize((char *)NameBuff);
+        home_replace(NULL, files_found[i], NameBuff, MAXPATHL, true);
+        j = vim_strsize(NameBuff);
       } else {
         j = vim_strsize(L_SHOWFILE(i));
       }
@@ -940,11 +940,11 @@ int showmatches(expand_T *xp, int wildmenu)
       for (k = i; k < num_files; k += lines) {
         if (xp->xp_context == EXPAND_TAGS_LISTFILES) {
           msg_outtrans_attr(files_found[k], HL_ATTR(HLF_D));
-          p = (char_u *)files_found[k] + strlen(files_found[k]) + 1;
+          p = files_found[k] + strlen(files_found[k]) + 1;
           msg_advance(maxlen + 1);
           msg_puts((const char *)p);
           msg_advance(maxlen + 3);
-          msg_outtrans_long_attr((char *)p + 2, HL_ATTR(HLF_D));
+          msg_outtrans_long_attr(p + 2, HL_ATTR(HLF_D));
           break;
         }
         for (j = maxlen - lastlen; --j >= 0;) {
@@ -958,10 +958,10 @@ int showmatches(expand_T *xp, int wildmenu)
             // Expansion was done before and special characters
             // were escaped, need to halve backslashes.  Also
             // $HOME has been replaced with ~/.
-            char_u *exp_path = expand_env_save_opt((char_u *)files_found[k], true);
-            char_u *path = exp_path != NULL ? exp_path : (char_u *)files_found[k];
-            char_u *halved_slash = (char_u *)backslash_halve_save((char *)path);
-            j = os_isdir((char *)halved_slash);
+            char *exp_path = (char *)expand_env_save_opt((char_u *)files_found[k], true);
+            char *path = exp_path != NULL ? exp_path : files_found[k];
+            char *halved_slash = backslash_halve_save(path);
+            j = os_isdir(halved_slash);
             xfree(exp_path);
             if (halved_slash != path) {
               xfree(halved_slash);
@@ -971,16 +971,16 @@ int showmatches(expand_T *xp, int wildmenu)
             j = os_isdir(files_found[k]);
           }
           if (showtail) {
-            p = (char_u *)L_SHOWFILE(k);
+            p = L_SHOWFILE(k);
           } else {
-            home_replace(NULL, files_found[k], (char *)NameBuff, MAXPATHL, true);
-            p = (char_u *)NameBuff;
+            home_replace(NULL, files_found[k], NameBuff, MAXPATHL, true);
+            p = NameBuff;
           }
         } else {
           j = false;
-          p = (char_u *)L_SHOWFILE(k);
+          p = L_SHOWFILE(k);
         }
-        lastlen = msg_outtrans_attr((char *)p, j ? attr : 0);
+        lastlen = msg_outtrans_attr(p, j ? attr : 0);
       }
       if (msg_col > 0) {        // when not wrapped around
         msg_clr_eos();
@@ -1008,11 +1008,11 @@ int showmatches(expand_T *xp, int wildmenu)
 /// Return the tail of file name path "s", ignoring a trailing "/".
 static char *showmatches_gettail(char *s, bool eager)
 {
-  char_u *p;
-  char_u *t = (char_u *)s;
+  char *p;
+  char *t = s;
   bool had_sep = false;
 
-  for (p = (char_u *)s; *p != NUL;) {
+  for (p = s; *p != NUL;) {
     if (vim_ispathsep(*p)
 #ifdef BACKSLASH_IN_FILENAME
         && !rem_backslash(p)
@@ -1029,7 +1029,7 @@ static char *showmatches_gettail(char *s, bool eager)
     }
     MB_PTR_ADV(p);
   }
-  return (char *)t;
+  return t;
 }
 
 /// Return true if we only need to show the tail of completion matches.
@@ -1037,8 +1037,8 @@ static char *showmatches_gettail(char *s, bool eager)
 /// returned.
 static bool expand_showtail(expand_T *xp)
 {
-  char_u *s;
-  char_u *end;
+  char *s;
+  char *end;
 
   // When not completing file names a "/" may mean something different.
   if (xp->xp_context != EXPAND_FILES
@@ -1047,15 +1047,15 @@ static bool expand_showtail(expand_T *xp)
     return false;
   }
 
-  end = (char_u *)path_tail(xp->xp_pattern);
-  if (end == (char_u *)xp->xp_pattern) {          // there is no path separator
+  end = path_tail(xp->xp_pattern);
+  if (end == xp->xp_pattern) {          // there is no path separator
     return false;
   }
 
-  for (s = (char_u *)xp->xp_pattern; s < end; s++) {
+  for (s = xp->xp_pattern; s < end; s++) {
     // Skip escaped wildcards.  Only when the backslash is not a path
     // separator, on DOS the '*' "path\*\file" must not be skipped.
-    if (rem_backslash((char *)s)) {
+    if (rem_backslash(s)) {
       s++;
     } else if (vim_strchr("*?[", *s) != NULL) {
       return false;
@@ -2149,9 +2149,9 @@ void set_cmd_context(expand_T *xp, char_u *str, int len, int col, int use_ccline
 /// @param col  position of cursor
 /// @param matchcount  return: nr of matches
 /// @param matches  return: array of pointers to matches
-int expand_cmdline(expand_T *xp, const char_u *str, int col, int *matchcount, char ***matches)
+int expand_cmdline(expand_T *xp, const char *str, int col, int *matchcount, char ***matches)
 {
-  char_u *file_str = NULL;
+  char *file_str = NULL;
   int options = WILD_ADD_SLASH|WILD_SILENT;
 
   if (xp->xp_context == EXPAND_UNSUCCESSFUL) {
@@ -2164,16 +2164,16 @@ int expand_cmdline(expand_T *xp, const char_u *str, int col, int *matchcount, ch
   }
 
   // add star to file name, or convert to regexp if not exp. files.
-  assert((str + col) - (char_u *)xp->xp_pattern >= 0);
-  xp->xp_pattern_len = (size_t)((str + col) - (char_u *)xp->xp_pattern);
-  file_str = (char_u *)addstar(xp->xp_pattern, xp->xp_pattern_len, xp->xp_context);
+  assert((str + col) - xp->xp_pattern >= 0);
+  xp->xp_pattern_len = (size_t)((str + col) - xp->xp_pattern);
+  file_str = addstar(xp->xp_pattern, xp->xp_pattern_len, xp->xp_context);
 
   if (p_wic) {
     options += WILD_ICASE;
   }
 
   // find all files that match the description
-  if (ExpandFromContext(xp, (char *)file_str, matchcount, matches, options) == FAIL) {
+  if (ExpandFromContext(xp, file_str, matchcount, matches, options) == FAIL) {
     *matchcount = 0;
     *matches = NULL;
   }
@@ -2424,7 +2424,7 @@ static int ExpandFromContext(expand_T *xp, char *pat, int *num_file, char ***fil
   }
   if (xp->xp_context == EXPAND_TAGS
       || xp->xp_context == EXPAND_TAGS_LISTFILES) {
-    return expand_tags(xp->xp_context == EXPAND_TAGS, (char_u *)pat, num_file, file);
+    return expand_tags(xp->xp_context == EXPAND_TAGS, pat, num_file, file);
   }
   if (xp->xp_context == EXPAND_COLORS) {
     char *directories[] = { "colors", NULL };
@@ -3097,7 +3097,7 @@ void wildmenu_cleanup(CmdlineInfo *cclp)
 /// "getcompletion()" function
 void f_getcompletion(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
-  char_u *pat;
+  char *pat;
   expand_T xpc;
   bool filtered = false;
   int options = WILD_SILENT | WILD_USE_NL | WILD_ADD_SLASH
@@ -3155,8 +3155,8 @@ void f_getcompletion(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   }
 
 theend:
-  pat = (char_u *)addstar(xpc.xp_pattern, xpc.xp_pattern_len, xpc.xp_context);
-  ExpandOne(&xpc, (char *)pat, NULL, options, WILD_ALL_KEEP);
+  pat = addstar(xpc.xp_pattern, xpc.xp_pattern_len, xpc.xp_context);
+  ExpandOne(&xpc, pat, NULL, options, WILD_ALL_KEEP);
   tv_list_alloc_ret(rettv, xpc.xp_numfiles);
 
   for (int i = 0; i < xpc.xp_numfiles; i++) {
diff --git a/src/nvim/cmdhist.c b/src/nvim/cmdhist.c
index 0556a56d5d..d12ac87bbb 100644
--- a/src/nvim/cmdhist.c
+++ b/src/nvim/cmdhist.c
@@ -648,7 +648,7 @@ void ex_history(exarg_T *eap)
     STRCPY(IObuff, "\n      #  ");
     assert(history_names[histype1] != NULL);
     STRCAT(STRCAT(IObuff, history_names[histype1]), " history");
-    msg_puts_title((char *)IObuff);
+    msg_puts_title(IObuff);
     idx = hisidx[histype1];
     hist = history[histype1];
     j = hisidx1;
@@ -667,15 +667,15 @@ void ex_history(exarg_T *eap)
         if (hist[i].hisstr != NULL
             && hist[i].hisnum >= j && hist[i].hisnum <= k) {
           msg_putchar('\n');
-          snprintf((char *)IObuff, IOSIZE, "%c%6d  ", i == idx ? '>' : ' ',
+          snprintf(IObuff, IOSIZE, "%c%6d  ", i == idx ? '>' : ' ',
                    hist[i].hisnum);
           if (vim_strsize(hist[i].hisstr) > Columns - 10) {
-            trunc_string(hist[i].hisstr, (char *)IObuff + strlen(IObuff),
+            trunc_string(hist[i].hisstr, IObuff + strlen(IObuff),
                          Columns - 10, IOSIZE - (int)strlen(IObuff));
           } else {
             STRCAT(IObuff, hist[i].hisstr);
           }
-          msg_outtrans((char *)IObuff);
+          msg_outtrans(IObuff);
         }
         if (i == idx) {
           break;
diff --git a/src/nvim/edit.c b/src/nvim/edit.c
index 611dab41a2..5646abf3c4 100644
--- a/src/nvim/edit.c
+++ b/src/nvim/edit.c
@@ -3167,7 +3167,7 @@ bool in_cinkeys(int keytyped, int when, bool line_is_empty)
           line = get_cursor_line_ptr();
           for (s = line + curwin->w_cursor.col; s > line; s = n) {
             n = (char *)mb_prevptr((char_u *)line, (char_u *)s);
-            if (!vim_iswordp((char_u *)n)) {
+            if (!vim_iswordp(n)) {
               break;
             }
           }
diff --git a/src/nvim/eval/encode.c b/src/nvim/eval/encode.c
index b7ef109f06..03d4862550 100644
--- a/src/nvim/eval/encode.c
+++ b/src/nvim/eval/encode.c
@@ -141,9 +141,9 @@ static int conv_error(const char *const msg, const MPConvStack *const mpstack,
                                                                   1))->hi_key },
       };
       char *const key = encode_tv2string(&key_tv, NULL);
-      vim_snprintf((char *)IObuff, IOSIZE, key_msg, key);
+      vim_snprintf(IObuff, IOSIZE, key_msg, key);
       xfree(key);
-      ga_concat(&msg_ga, (char *)IObuff);
+      ga_concat(&msg_ga, IObuff);
       break;
     }
     case kMPConvPairs:
@@ -163,8 +163,8 @@ static int conv_error(const char *const msg, const MPConvStack *const mpstack,
           || li == NULL
           || (TV_LIST_ITEM_TV(li)->v_type != VAR_LIST
               && tv_list_len(TV_LIST_ITEM_TV(li)->vval.v_list) <= 0)) {
-        vim_snprintf((char *)IObuff, IOSIZE, idx_msg, idx);
-        ga_concat(&msg_ga, (char *)IObuff);
+        vim_snprintf(IObuff, IOSIZE, idx_msg, idx);
+        ga_concat(&msg_ga, IObuff);
       } else {
         assert(li != NULL);
         listitem_T *const first_item =
@@ -172,9 +172,9 @@ static int conv_error(const char *const msg, const MPConvStack *const mpstack,
         assert(first_item != NULL);
         typval_T key_tv = *TV_LIST_ITEM_TV(first_item);
         char *const key = encode_tv2echo(&key_tv, NULL);
-        vim_snprintf((char *)IObuff, IOSIZE, key_pair_msg, key, idx);
+        vim_snprintf(IObuff, IOSIZE, key_pair_msg, key, idx);
         xfree(key);
-        ga_concat(&msg_ga, (char *)IObuff);
+        ga_concat(&msg_ga, IObuff);
       }
       break;
     }
@@ -193,8 +193,8 @@ static int conv_error(const char *const msg, const MPConvStack *const mpstack,
       break;
     case kMPConvPartialList: {
       const int idx = (int)(v.data.a.arg - v.data.a.argv) - 1;
-      vim_snprintf((char *)IObuff, IOSIZE, partial_arg_i_msg, idx);
-      ga_concat(&msg_ga, (char *)IObuff);
+      vim_snprintf(IObuff, IOSIZE, partial_arg_i_msg, idx);
+      ga_concat(&msg_ga, IObuff);
       break;
     }
     }
diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index b79a69bc6e..5cb4dc2631 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -169,13 +169,13 @@ char *get_function_name(expand_T *xp, int idx)
     intidx = -1;
   }
   if (intidx < 0) {
-    char_u *name = (char_u *)get_user_func_name(xp, idx);
+    char *name = get_user_func_name(xp, idx);
     if (name != NULL) {
       if (*name != NUL && *name != '<'
           && strncmp("g:", xp->xp_pattern, 2) == 0) {
-        return cat_prefix_varname('g', (char *)name);
+        return cat_prefix_varname('g', name);
       }
-      return (char *)name;
+      return name;
     }
   }
 
@@ -192,7 +192,7 @@ char *get_function_name(expand_T *xp, int idx)
   } else {
     IObuff[key_len + 1] = NUL;
   }
-  return (char *)IObuff;
+  return IObuff;
 }
 
 /// Function given to ExpandGeneric() to obtain the list of internal or
@@ -205,9 +205,9 @@ char *get_expr_name(expand_T *xp, int idx)
     intidx = -1;
   }
   if (intidx < 0) {
-    char_u *name = (char_u *)get_function_name(xp, idx);
+    char *name = get_function_name(xp, idx);
     if (name != NULL) {
-      return (char *)name;
+      return name;
     }
   }
   return get_user_var_name(xp, ++intidx);
@@ -548,19 +548,19 @@ static void f_call(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   }
 
   bool owned = false;
-  char_u *func;
+  char *func;
   partial_T *partial = NULL;
   if (argvars[0].v_type == VAR_FUNC) {
-    func = (char_u *)argvars[0].vval.v_string;
+    func = argvars[0].vval.v_string;
   } else if (argvars[0].v_type == VAR_PARTIAL) {
     partial = argvars[0].vval.v_partial;
-    func = (char_u *)partial_name(partial);
+    func = partial_name(partial);
   } else if (nlua_is_table_from_lua(&argvars[0])) {
     // TODO(tjdevries): UnifiedCallback
-    func = nlua_register_table_as_callable(&argvars[0]);
+    func = (char *)nlua_register_table_as_callable(&argvars[0]);
     owned = true;
   } else {
-    func = (char_u *)tv_get_string(&argvars[0]);
+    func = (char *)tv_get_string(&argvars[0]);
   }
 
   if (*func == NUL) {
@@ -572,16 +572,16 @@ static void f_call(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     if (argvars[2].v_type != VAR_DICT) {
       emsg(_(e_dictreq));
       if (owned) {
-        func_unref(func);
+        func_unref((char_u *)func);
       }
       return;
     }
     selfdict = argvars[2].vval.v_dict;
   }
 
-  func_call(func, &argvars[1], partial, selfdict, rettv);
+  func_call((char_u *)func, &argvars[1], partial, selfdict, rettv);
   if (owned) {
-    func_unref(func);
+    func_unref((char_u *)func);
   }
 }
 
@@ -949,7 +949,7 @@ static void f_count(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 
   if (argvars[0].v_type == VAR_STRING) {
     const char *expr = tv_get_string_chk(&argvars[1]);
-    const char_u *p = (char_u *)argvars[0].vval.v_string;
+    const char *p = argvars[0].vval.v_string;
 
     if (!error && expr != NULL && *expr != NUL && p != NULL) {
       if (ic) {
@@ -964,8 +964,8 @@ static void f_count(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
           }
         }
       } else {
-        char_u *next;
-        while ((next = (char_u *)strstr((char *)p, (char *)expr)) != NULL) {
+        char *next;
+        while ((next = strstr((char *)p, (char *)expr)) != NULL) {
           n++;
           p = next + strlen(expr);
         }
@@ -1531,14 +1531,14 @@ static void f_escape(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 /// "getenv()" function
 static void f_getenv(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
-  char_u *p = (char_u *)vim_getenv(tv_get_string(&argvars[0]));
+  char *p = vim_getenv(tv_get_string(&argvars[0]));
 
   if (p == NULL) {
     rettv->v_type = VAR_SPECIAL;
     rettv->vval.v_special = kSpecialVarNull;
     return;
   }
-  rettv->vval.v_string = (char *)p;
+  rettv->vval.v_string = p;
   rettv->v_type = VAR_STRING;
 }
 
@@ -1771,7 +1771,7 @@ static void f_expand(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     }
     size_t len;
     char *errormsg = NULL;
-    char_u *result = eval_vars((char_u *)s, (char_u *)s, &len, NULL, &errormsg, NULL, false);
+    char *result = (char *)eval_vars((char_u *)s, (char_u *)s, &len, NULL, &errormsg, NULL, false);
     if (p_verbose == 0) {
       emsg_off--;
     } else if (errormsg != NULL) {
@@ -1784,7 +1784,7 @@ static void f_expand(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
       }
       XFREE_CLEAR(result);
     } else {
-      rettv->vval.v_string = (char *)result;
+      rettv->vval.v_string = result;
     }
   } else {
     // When the optional second argument is non-zero, don't remove matches
@@ -2022,8 +2022,8 @@ static void f_filewritable(typval_T *argvars, typval_T *rettv, EvalFuncData fptr
 
 static void findfilendir(typval_T *argvars, typval_T *rettv, int find_what)
 {
-  char_u *fresult = NULL;
-  char_u *path = *curbuf->b_p_path == NUL ? p_path : (char_u *)curbuf->b_p_path;
+  char *fresult = NULL;
+  char *path = *curbuf->b_p_path == NUL ? (char *)p_path : curbuf->b_p_path;
   int count = 1;
   bool first = true;
   bool error = false;
@@ -2040,7 +2040,7 @@ static void findfilendir(typval_T *argvars, typval_T *rettv, int find_what)
       error = true;
     } else {
       if (*p != NUL) {
-        path = (char_u *)p;
+        path = (char *)p;
       }
 
       if (argvars[2].v_type != VAR_UNKNOWN) {
@@ -2058,13 +2058,13 @@ static void findfilendir(typval_T *argvars, typval_T *rettv, int find_what)
       if (rettv->v_type == VAR_STRING || rettv->v_type == VAR_LIST) {
         xfree(fresult);
       }
-      fresult = (char_u *)find_file_in_path_option(first ? (char *)fname : NULL,
-                                                   first ? strlen(fname) : 0,
-                                                   0, first, (char *)path,
-                                                   find_what, curbuf->b_ffname,
-                                                   (find_what == FINDFILE_DIR
-                                                    ? ""
-                                                    : curbuf->b_p_sua));
+      fresult = find_file_in_path_option(first ? (char *)fname : NULL,
+                                         first ? strlen(fname) : 0,
+                                         0, first, path,
+                                         find_what, curbuf->b_ffname,
+                                         (find_what == FINDFILE_DIR
+                                          ? ""
+                                          : curbuf->b_p_sua));
       first = false;
 
       if (fresult != NULL && rettv->v_type == VAR_LIST) {
@@ -2074,7 +2074,7 @@ static void findfilendir(typval_T *argvars, typval_T *rettv, int find_what)
   }
 
   if (rettv->v_type == VAR_STRING) {
-    rettv->vval.v_string = (char *)fresult;
+    rettv->vval.v_string = fresult;
   }
 }
 
@@ -2138,7 +2138,7 @@ static void f_fnameescape(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 /// "fnamemodify({fname}, {mods})" function
 static void f_fnamemodify(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
-  char_u *fbuf = NULL;
+  char *fbuf = NULL;
   size_t len = 0;
   char buf[NUMBUFLEN];
   const char *fname = tv_get_string_chk(&argvars[0]);
@@ -2150,7 +2150,7 @@ static void f_fnamemodify(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     if (*mods != NUL) {
       size_t usedlen = 0;
       (void)modify_fname((char *)mods, false, &usedlen,
-                         (char **)&fname, (char **)&fbuf, &len);
+                         (char **)&fname, &fbuf, &len);
     }
   }
 
@@ -2545,7 +2545,7 @@ static void f_getfontname(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 static void f_getfperm(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
   char *perm = NULL;
-  char_u flags[] = "rwx";
+  char flags[] = "rwx";
 
   const char *filename = tv_get_string(&argvars[0]);
   int32_t file_perm = os_getperm(filename);
@@ -2553,7 +2553,7 @@ static void f_getfperm(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     perm = xstrdup("---------");
     for (int i = 0; i < 9; i++) {
       if (file_perm & (1 << (8 - i))) {
-        perm[i] = (char)flags[i % 3];
+        perm[i] = flags[i % 3];
       }
     }
   }
@@ -6780,14 +6780,14 @@ long do_searchpair(const char *spat, const char *mpat, const char *epat, int dir
   // Make two search patterns: start/end (pat2, for in nested pairs) and
   // start/middle/end (pat3, for the top pair).
   const size_t pat2_len = strlen(spat) + strlen(epat) + 17;
-  char_u *pat2 = xmalloc(pat2_len);
+  char *pat2 = xmalloc(pat2_len);
   const size_t pat3_len = strlen(spat) + strlen(mpat) + strlen(epat) + 25;
-  char_u *pat3 = xmalloc(pat3_len);
-  snprintf((char *)pat2, pat2_len, "\\m\\(%s\\m\\)\\|\\(%s\\m\\)", spat, epat);
+  char *pat3 = xmalloc(pat3_len);
+  snprintf(pat2, pat2_len, "\\m\\(%s\\m\\)\\|\\(%s\\m\\)", spat, epat);
   if (*mpat == NUL) {
     STRCPY(pat3, pat2);
   } else {
-    snprintf((char *)pat3, pat3_len,
+    snprintf(pat3, pat3_len,
              "\\m\\(%s\\m\\)\\|\\(%s\\m\\)\\|\\(%s\\m\\)", spat, epat, mpat);
   }
   if (flags & SP_START) {
@@ -6804,14 +6804,14 @@ long do_searchpair(const char *spat, const char *mpat, const char *epat, int dir
   clearpos(&firstpos);
   pos_T foundpos;
   clearpos(&foundpos);
-  char_u *pat = pat3;
+  char *pat = pat3;
   for (;;) {
     searchit_arg_T sia = {
       .sa_stop_lnum = lnum_stop,
       .sa_tm = &tm,
     };
 
-    int n = searchit(curwin, curbuf, &pos, NULL, dir, pat, 1L,
+    int n = searchit(curwin, curbuf, &pos, NULL, dir, (char_u *)pat, 1L,
                      options, RE_SEARCH, &sia);
     if (n == FAIL || (firstpos.lnum != 0 && equalpos(pos, firstpos))) {
       // didn't find it or found the first match again: FAIL
@@ -7755,10 +7755,10 @@ static void f_str2float(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 static void f_str2list(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
   tv_list_alloc_ret(rettv, kListLenUnknown);
-  const char_u *p = (const char_u *)tv_get_string(&argvars[0]);
+  const char *p = tv_get_string(&argvars[0]);
 
-  for (; *p != NUL; p += utf_ptr2len((char *)p)) {
-    tv_list_append_number(rettv->vval.v_list, utf_ptr2char((char *)p));
+  for (; *p != NUL; p += utf_ptr2len(p)) {
+    tv_list_append_number(rettv->vval.v_list, utf_ptr2char(p));
   }
 }
 
@@ -7779,10 +7779,10 @@ static void f_str2nr(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     }
   }
 
-  char_u *p = (char_u *)skipwhite(tv_get_string(&argvars[0]));
+  char *p = skipwhite(tv_get_string(&argvars[0]));
   bool isneg = (*p == '-');
   if (*p == '+' || *p == '-') {
-    p = (char_u *)skipwhite((char *)p + 1);
+    p = skipwhite(p + 1);
   }
   switch (base) {
   case 2:
@@ -7796,7 +7796,7 @@ static void f_str2nr(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     break;
   }
   varnumber_T n;
-  vim_str2nr((char *)p, NULL, NULL, what, &n, NULL, 0, false);
+  vim_str2nr(p, NULL, NULL, what, &n, NULL, 0, false);
   // Text after the number is silently ignored.
   if (isneg) {
     rettv->vval.v_number = -n;
@@ -8372,7 +8372,7 @@ static void f_synconcealed(typval_T *argvars, typval_T *rettv, EvalFuncData fptr
   int syntax_flags = 0;
   int cchar;
   int matchid = 0;
-  char_u str[NUMBUFLEN];
+  char str[NUMBUFLEN];
 
   tv_list_set_ret(rettv, NULL);
 
@@ -8396,7 +8396,7 @@ static void f_synconcealed(typval_T *argvars, typval_T *rettv, EvalFuncData fptr
           : curwin->w_p_lcs_chars.conceal;
       }
       if (cchar != NUL) {
-        utf_char2bytes(cchar, (char *)str);
+        utf_char2bytes(cchar, str);
       }
     }
   }
@@ -8404,7 +8404,7 @@ static void f_synconcealed(typval_T *argvars, typval_T *rettv, EvalFuncData fptr
   tv_list_alloc_ret(rettv, 3);
   tv_list_append_number(rettv->vval.v_list, (syntax_flags & HL_CONCEAL) != 0);
   // -1 to auto-determine strlen
-  tv_list_append_string(rettv->vval.v_list, (const char *)str, -1);
+  tv_list_append_string(rettv->vval.v_list, str, -1);
   tv_list_append_number(rettv->vval.v_list, matchid);
 }
 
@@ -8497,7 +8497,7 @@ static void f_taglist(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     fname = tv_get_string(&argvars[1]);
   }
   (void)get_tags(tv_list_alloc_ret(rettv, kListLenUnknown),
-                 (char_u *)tag_pattern, (char_u *)fname);
+                 (char *)tag_pattern, (char *)fname);
 }
 
 /// "tempname()" function
@@ -8591,9 +8591,9 @@ static void f_termopen(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   int pid = chan->stream.pty.process.pid;
 
   // "./…" => "/home/foo/…"
-  vim_FullName(cwd, (char *)NameBuff, sizeof(NameBuff), false);
+  vim_FullName(cwd, NameBuff, sizeof(NameBuff), false);
   // "/home/foo/…" => "~/…"
-  size_t len = home_replace(NULL, (char *)NameBuff, (char *)IObuff, sizeof(IObuff), true);
+  size_t len = home_replace(NULL, NameBuff, IObuff, sizeof(IObuff), true);
   // Trim slash.
   if (len != 1 && (IObuff[len - 1] == '\\' || IObuff[len - 1] == '/')) {
     IObuff[len - 1] = '\0';
@@ -8606,14 +8606,14 @@ static void f_termopen(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   }
 
   // Terminal URI: "term://$CWD//$PID:$CMD"
-  snprintf((char *)NameBuff, sizeof(NameBuff), "term://%s//%d:%s",
-           (char *)IObuff, pid, cmd);
+  snprintf(NameBuff, sizeof(NameBuff), "term://%s//%d:%s",
+           IObuff, pid, cmd);
   // at this point the buffer has no terminal instance associated yet, so unset
   // the 'swapfile' option to ensure no swap file will be created
   curbuf->b_p_swf = false;
 
   apply_autocmds(EVENT_BUFFILEPRE, NULL, NULL, false, curbuf);
-  (void)setfname(curbuf, (char *)NameBuff, NULL, true);
+  (void)setfname(curbuf, NameBuff, NULL, true);
   apply_autocmds(EVENT_BUFFILEPOST, NULL, NULL, false, curbuf);
 
   // Save the job id and pid in b:terminal_job_{id,pid}
diff --git a/src/nvim/eval/userfunc.c b/src/nvim/eval/userfunc.c
index 9f6aa0776c..54c4285453 100644
--- a/src/nvim/eval/userfunc.c
+++ b/src/nvim/eval/userfunc.c
@@ -259,13 +259,13 @@ int get_lambda_tv(char **arg, typval_T *rettv, bool evaluate)
   partial_T *pt = NULL;
   int varargs;
   int ret;
-  char_u *start = (char_u *)skipwhite(*arg + 1);
+  char *start = skipwhite(*arg + 1);
   char *s, *e;
   bool *old_eval_lavars = eval_lavars_used;
   bool eval_lavars = false;
 
   // First, check if this is a lambda expression. "->" must exists.
-  ret = get_function_args((char **)&start, '-', NULL, NULL, NULL, true);
+  ret = get_function_args(&start, '-', NULL, NULL, NULL, true);
   if (ret == FAIL || *start != '>') {
     return NOTDONE;
   }
@@ -2765,7 +2765,7 @@ char *get_user_func_name(expand_T *xp, int idx)
         STRCAT(IObuff, ")");
       }
     }
-    return (char *)IObuff;
+    return IObuff;
   }
   return NULL;
 }
@@ -2950,7 +2950,7 @@ static int can_free_funccal(funccall_T *fc, int copyID)
 /// ":return [expr]"
 void ex_return(exarg_T *eap)
 {
-  char_u *arg = (char_u *)eap->arg;
+  char *arg = eap->arg;
   typval_T rettv;
   int returning = false;
 
@@ -2965,7 +2965,7 @@ void ex_return(exarg_T *eap)
 
   eap->nextcmd = NULL;
   if ((*arg != NUL && *arg != '|' && *arg != '\n')
-      && eval0((char *)arg, &rettv, &eap->nextcmd, !eap->skip) != FAIL) {
+      && eval0(arg, &rettv, &eap->nextcmd, !eap->skip) != FAIL) {
     if (!eap->skip) {
       returning = do_return(eap, false, true, &rettv);
     } else {
@@ -2988,7 +2988,7 @@ void ex_return(exarg_T *eap)
   if (returning) {
     eap->nextcmd = NULL;
   } else if (eap->nextcmd == NULL) {          // no argument
-    eap->nextcmd = check_nextcmd((char *)arg);
+    eap->nextcmd = check_nextcmd(arg);
   }
 
   if (eap->skip) {
@@ -2999,9 +2999,9 @@ void ex_return(exarg_T *eap)
 /// ":1,25call func(arg1, arg2)" function call.
 void ex_call(exarg_T *eap)
 {
-  char_u *arg = (char_u *)eap->arg;
-  char_u *startarg;
-  char_u *name;
+  char *arg = eap->arg;
+  char *startarg;
+  char *name;
   char *tofree;
   int len;
   typval_T rettv;
@@ -3023,7 +3023,7 @@ void ex_call(exarg_T *eap)
     return;
   }
 
-  tofree = (char *)trans_function_name((char **)&arg, false, TFN_INT, &fudi, &partial);
+  tofree = (char *)trans_function_name(&arg, false, TFN_INT, &fudi, &partial);
   if (fudi.fd_newkey != NULL) {
     // Still need to give an error message for missing key.
     semsg(_(e_dictkey), fudi.fd_newkey);
@@ -3043,11 +3043,11 @@ void ex_call(exarg_T *eap)
   // contents. For VAR_PARTIAL get its partial, unless we already have one
   // from trans_function_name().
   len = (int)strlen(tofree);
-  name = deref_func_name(tofree, &len, partial != NULL ? NULL : &partial, false);
+  name = (char *)deref_func_name(tofree, &len, partial != NULL ? NULL : &partial, false);
 
   // Skip white space to allow ":call func ()".  Not good, but required for
   // backward compatibility.
-  startarg = (char_u *)skipwhite((char *)arg);
+  startarg = skipwhite(arg);
   rettv.v_type = VAR_UNKNOWN;  // tv_clear() uses this.
 
   if (*startarg != '(') {
@@ -3077,7 +3077,7 @@ void ex_call(exarg_T *eap)
     funcexe.fe_evaluate = true;
     funcexe.fe_partial = partial;
     funcexe.fe_selfdict = fudi.fd_dict;
-    if (get_func_tv(name, -1, &rettv, (char **)&arg, &funcexe) == FAIL) {
+    if (get_func_tv((char_u *)name, -1, &rettv, &arg, &funcexe) == FAIL) {
       failed = true;
       break;
     }
@@ -3114,7 +3114,7 @@ void ex_call(exarg_T *eap)
         semsg(_(e_trailing_arg), arg);
       }
     } else {
-      eap->nextcmd = check_nextcmd((char *)arg);
+      eap->nextcmd = check_nextcmd(arg);
     }
   }
 
@@ -3219,7 +3219,7 @@ char *get_return_cmd(void *rettv)
     STRCPY(IObuff + IOSIZE - 4, "...");
   }
   xfree(tofree);
-  return xstrdup((char *)IObuff);
+  return xstrdup(IObuff);
 }
 
 /// Get next function line.
@@ -3296,21 +3296,21 @@ int func_has_abort(void *cookie)
 /// Changes "rettv" in-place.
 void make_partial(dict_T *const selfdict, typval_T *const rettv)
 {
-  char_u *fname;
-  char_u *tofree = NULL;
+  char *fname;
+  char *tofree = NULL;
   ufunc_T *fp;
-  char_u fname_buf[FLEN_FIXED + 1];
+  char fname_buf[FLEN_FIXED + 1];
   int error;
 
   if (rettv->v_type == VAR_PARTIAL && rettv->vval.v_partial->pt_func != NULL) {
     fp = rettv->vval.v_partial->pt_func;
   } else {
     fname = rettv->v_type == VAR_FUNC || rettv->v_type == VAR_STRING
-                                      ? (char_u *)rettv->vval.v_string
-                                      : (char_u *)rettv->vval.v_partial->pt_name;
+                                      ? rettv->vval.v_string
+                                      : rettv->vval.v_partial->pt_name;
     // Translate "s:func" to the stored function name.
-    fname = (char_u *)fname_trans_sid((char *)fname, (char *)fname_buf, (char **)&tofree, &error);
-    fp = find_func(fname);
+    fname = fname_trans_sid(fname, (char *)fname_buf, &tofree, &error);
+    fp = find_func((char_u *)fname);
     xfree(tofree);
   }
 
@@ -3646,17 +3646,17 @@ bool set_ref_in_func(char_u *name, ufunc_T *fp_in, int copyID)
   ufunc_T *fp = fp_in;
   funccall_T *fc;
   int error = FCERR_NONE;
-  char_u fname_buf[FLEN_FIXED + 1];
-  char_u *tofree = NULL;
-  char_u *fname;
+  char fname_buf[FLEN_FIXED + 1];
+  char *tofree = NULL;
+  char *fname;
   bool abort = false;
   if (name == NULL && fp_in == NULL) {
     return false;
   }
 
   if (fp_in == NULL) {
-    fname = (char_u *)fname_trans_sid((char *)name, (char *)fname_buf, (char **)&tofree, &error);
-    fp = find_func(fname);
+    fname = fname_trans_sid((char *)name, (char *)fname_buf, &tofree, &error);
+    fp = find_func((char_u *)fname);
   }
   if (fp != NULL) {
     for (fc = fp->uf_scoped; fc != NULL; fc = fc->func->uf_scoped) {
diff --git a/src/nvim/ex_cmds.c b/src/nvim/ex_cmds.c
index 8d230c699d..8861d0e7e3 100644
--- a/src/nvim/ex_cmds.c
+++ b/src/nvim/ex_cmds.c
@@ -160,12 +160,12 @@ void do_ascii(const exarg_T *const eap)
 
     dig = (char *)get_digraph_for_char(cval);
     if (dig != NULL) {
-      iobuff_len += (size_t)vim_snprintf((char *)IObuff + iobuff_len,
+      iobuff_len += (size_t)vim_snprintf(IObuff + iobuff_len,
                                          sizeof(IObuff) - iobuff_len,
                                          _("<%s>%s%s  %d,  Hex %02x,  Oct %03o, Digr %s"),
                                          transchar(c), buf1, buf2, cval, cval, cval, dig);
     } else {
-      iobuff_len += (size_t)vim_snprintf((char *)IObuff + iobuff_len,
+      iobuff_len += (size_t)vim_snprintf(IObuff + iobuff_len,
                                          sizeof(IObuff) - iobuff_len,
                                          _("<%s>%s%s  %d,  Hex %02x,  Octal %03o"),
                                          transchar(c), buf1, buf2, cval, cval, cval);
@@ -204,18 +204,18 @@ void do_ascii(const exarg_T *const eap)
     if (utf_iscomposing(c)) {
       IObuff[iobuff_len++] = ' ';  // Draw composing char on top of a space.
     }
-    iobuff_len += (size_t)utf_char2bytes(c, (char *)IObuff + iobuff_len);
+    iobuff_len += (size_t)utf_char2bytes(c, IObuff + iobuff_len);
 
     dig = (char *)get_digraph_for_char(c);
     if (dig != NULL) {
-      iobuff_len += (size_t)vim_snprintf((char *)IObuff + iobuff_len,
+      iobuff_len += (size_t)vim_snprintf(IObuff + iobuff_len,
                                          sizeof(IObuff) - iobuff_len,
                                          (c < 0x10000
                                           ? _("> %d, Hex %04x, Oct %o, Digr %s")
                                           : _("> %d, Hex %08x, Oct %o, Digr %s")),
                                          c, c, c, dig);
     } else {
-      iobuff_len += (size_t)vim_snprintf((char *)IObuff + iobuff_len,
+      iobuff_len += (size_t)vim_snprintf(IObuff + iobuff_len,
                                          sizeof(IObuff) - iobuff_len,
                                          (c < 0x10000
                                           ? _("> %d, Hex %04x, Octal %o")
@@ -228,10 +228,10 @@ void do_ascii(const exarg_T *const eap)
     c = cc[ci++];
   }
   if (ci != MAX_MCO && c != 0) {
-    xstrlcpy((char *)IObuff + iobuff_len, " ...", sizeof(IObuff) - iobuff_len);
+    xstrlcpy(IObuff + iobuff_len, " ...", sizeof(IObuff) - iobuff_len);
   }
 
-  msg((char *)IObuff);
+  msg(IObuff);
 }
 
 /// ":left", ":center" and ":right": align text.
diff --git a/src/nvim/ex_docmd.c b/src/nvim/ex_docmd.c
index 7921fe0fc2..e847f74289 100644
--- a/src/nvim/ex_docmd.c
+++ b/src/nvim/ex_docmd.c
@@ -869,10 +869,10 @@ void handle_did_throw(void)
   // interrupt message is given elsewhere.
   switch (current_exception->type) {
   case ET_USER:
-    vim_snprintf((char *)IObuff, IOSIZE,
+    vim_snprintf(IObuff, IOSIZE,
                  _("E605: Exception not caught: %s"),
                  current_exception->value);
-    p = xstrdup((char *)IObuff);
+    p = xstrdup(IObuff);
     break;
   case ET_ERROR:
     messages = current_exception->messages;
@@ -1445,7 +1445,7 @@ bool parse_cmdline(char *cmdline, exarg_T *eap, CmdParseInfo *cmdinfo, char **er
     // If the modifier was parsed OK the error must be in the following command
     char *cmdname = after_modifier ? after_modifier : cmdline;
     append_command(cmdname);
-    *errormsg = (char *)IObuff;
+    *errormsg = IObuff;
     goto end;
   }
 
@@ -2038,7 +2038,7 @@ static char *do_one_cmd(char **cmdlinep, int flags, cstack_T *cstack, LineGetter
       if (!(flags & DOCMD_VERBOSE)) {
         append_command(cmdname);
       }
-      errormsg = (char *)IObuff;
+      errormsg = IObuff;
       did_emsg_syntax = true;
       verify_command(cmdname);
     }
@@ -2307,9 +2307,9 @@ doend:
 
   if (errormsg != NULL && *errormsg != NUL && !did_emsg) {
     if (flags & DOCMD_VERBOSE) {
-      if (errormsg != (char *)IObuff) {
+      if (errormsg != IObuff) {
         STRCPY(IObuff, errormsg);
-        errormsg = (char *)IObuff;
+        errormsg = IObuff;
       }
       append_command(*ea.cmdlinep);
     }
@@ -2870,8 +2870,8 @@ static void append_command(char *cmd)
 
   if (len > IOSIZE - 100) {
     // Not enough space, truncate and put in "...".
-    d = (char *)IObuff + IOSIZE - 100;
-    d -= utf_head_off((char *)IObuff, d);
+    d = IObuff + IOSIZE - 100;
+    d -= utf_head_off(IObuff, d);
     STRCPY(d, "...");
   }
   STRCAT(IObuff, ": ");
@@ -3840,7 +3840,7 @@ int expand_filename(exarg_T *eap, char **cmdlinep, char **errormsgp)
           || vim_strchr(eap->arg, '~') != NULL) {
         expand_env_esc(eap->arg, NameBuff, MAXPATHL, true, true, NULL);
         has_wildcards = path_has_wildcard(NameBuff);
-        p = (char *)NameBuff;
+        p = NameBuff;
       } else {
         p = NULL;
       }
@@ -5089,8 +5089,8 @@ static void ex_tabs(exarg_T *eap)
     }
 
     msg_putchar('\n');
-    vim_snprintf((char *)IObuff, IOSIZE, _("Tab page %d"), tabcount++);
-    msg_outtrans_attr((char *)IObuff, HL_ATTR(HLF_T));
+    vim_snprintf(IObuff, IOSIZE, _("Tab page %d"), tabcount++);
+    msg_outtrans_attr(IObuff, HL_ATTR(HLF_T));
     os_breakcheck();
 
     FOR_ALL_WINDOWS_IN_TAB(wp, tp) {
@@ -5106,9 +5106,9 @@ static void ex_tabs(exarg_T *eap)
       if (buf_spname(wp->w_buffer) != NULL) {
         xstrlcpy(IObuff, buf_spname(wp->w_buffer), IOSIZE);
       } else {
-        home_replace(wp->w_buffer, wp->w_buffer->b_fname, (char *)IObuff, IOSIZE, true);
+        home_replace(wp->w_buffer, wp->w_buffer->b_fname, IObuff, IOSIZE, true);
       }
-      msg_outtrans((char *)IObuff);
+      msg_outtrans(IObuff);
       os_breakcheck();
     }
   }
@@ -5559,7 +5559,7 @@ bool changedir_func(char *new_dir, CdScope scope)
 #endif
     // Use NameBuff for home directory name.
     expand_env("$HOME", NameBuff, MAXPATHL);
-    new_dir = (char *)NameBuff;
+    new_dir = NameBuff;
   }
 
   bool dir_differs = pdir == NULL || pathcmp(pdir, new_dir, -1) != 0;
@@ -5640,9 +5640,9 @@ static void ex_pwd(exarg_T *eap)
       } else if (curtab->tp_localdir != NULL) {
         context = "tabpage";
       }
-      smsg("[%s] %s", context, (char *)NameBuff);
+      smsg("[%s] %s", context, NameBuff);
     } else {
-      msg((char *)NameBuff);
+      msg(NameBuff);
     }
   } else {
     emsg(_("E187: Unknown"));
diff --git a/src/nvim/ex_eval.c b/src/nvim/ex_eval.c
index 137e94145a..6450892e39 100644
--- a/src/nvim/ex_eval.c
+++ b/src/nvim/ex_eval.c
@@ -538,7 +538,7 @@ static void discard_exception(except_T *excp, bool was_finished)
   if (p_verbose >= 13 || debug_break_level > 0) {
     int save_msg_silent = msg_silent;
 
-    saved_IObuff = xstrdup((char *)IObuff);
+    saved_IObuff = xstrdup(IObuff);
     if (debug_break_level > 0) {
       msg_silent = false;               // display messages
     } else {
@@ -592,12 +592,12 @@ static void catch_exception(except_T *excp)
   set_vim_var_string(VV_EXCEPTION, excp->value, -1);
   if (*excp->throw_name != NUL) {
     if (excp->throw_lnum != 0) {
-      vim_snprintf((char *)IObuff, IOSIZE, _("%s, line %" PRId64),
+      vim_snprintf(IObuff, IOSIZE, _("%s, line %" PRId64),
                    excp->throw_name, (int64_t)excp->throw_lnum);
     } else {
-      vim_snprintf((char *)IObuff, IOSIZE, "%s", excp->throw_name);
+      vim_snprintf(IObuff, IOSIZE, "%s", excp->throw_name);
     }
-    set_vim_var_string(VV_THROWPOINT, (char *)IObuff, -1);
+    set_vim_var_string(VV_THROWPOINT, IObuff, -1);
   } else {
     // throw_name not set on an exception from a command that was typed.
     set_vim_var_string(VV_THROWPOINT, NULL, -1);
@@ -641,14 +641,14 @@ static void finish_exception(except_T *excp)
     set_vim_var_string(VV_EXCEPTION, caught_stack->value, -1);
     if (*caught_stack->throw_name != NUL) {
       if (caught_stack->throw_lnum != 0) {
-        vim_snprintf((char *)IObuff, IOSIZE,
+        vim_snprintf(IObuff, IOSIZE,
                      _("%s, line %" PRId64), caught_stack->throw_name,
                      (int64_t)caught_stack->throw_lnum);
       } else {
-        vim_snprintf((char *)IObuff, IOSIZE, "%s",
+        vim_snprintf(IObuff, IOSIZE, "%s",
                      caught_stack->throw_name);
       }
-      set_vim_var_string(VV_THROWPOINT, (char *)IObuff, -1);
+      set_vim_var_string(VV_THROWPOINT, IObuff, -1);
     } else {
       // throw_name not set on an exception from a command that was
       // typed.
@@ -714,9 +714,9 @@ static void report_pending(int action, int pending, void *value)
 
   default:
     if (pending & CSTP_THROW) {
-      vim_snprintf((char *)IObuff, IOSIZE,
+      vim_snprintf(IObuff, IOSIZE,
                    mesg, _("Exception"));
-      mesg = concat_str((char *)IObuff, ": %s");
+      mesg = concat_str(IObuff, ": %s");
       s = ((except_T *)value)->value;
     } else if ((pending & CSTP_ERROR) && (pending & CSTP_INTERRUPT)) {
       s = _("Error and interrupt");
diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index 16aaca8a24..93d137eab9 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -2099,7 +2099,7 @@ static int command_line_handle_key(CommandLineState *s)
   if (IS_SPECIAL(s->c) || mod_mask != 0) {
     put_on_cmdline(get_special_key_name(s->c, mod_mask), -1, true);
   } else {
-    int j = utf_char2bytes(s->c, (char *)IObuff);
+    int j = utf_char2bytes(s->c, IObuff);
     IObuff[j] = NUL;                // exclude composing chars
     put_on_cmdline((char_u *)IObuff, j, true);
   }
diff --git a/src/nvim/file_search.c b/src/nvim/file_search.c
index b1742c04c3..5c5839cb08 100644
--- a/src/nvim/file_search.c
+++ b/src/nvim/file_search.c
@@ -1408,7 +1408,7 @@ char *find_file_in_path_option(char *ptr, size_t len, int options, int first, ch
             && rel_fname != NULL
             && strlen(rel_fname) + l < MAXPATHL) {
           STRCPY(NameBuff, rel_fname);
-          STRCPY(path_tail((char *)NameBuff), ff_file_to_find);
+          STRCPY(path_tail(NameBuff), ff_file_to_find);
           l = strlen(NameBuff);
         } else {
           STRCPY(NameBuff, ff_file_to_find);
@@ -1429,7 +1429,7 @@ char *find_file_in_path_option(char *ptr, size_t len, int options, int first, ch
             break;
           }
           assert(MAXPATHL >= l);
-          copy_option_part(&buf, (char *)NameBuff + l, MAXPATHL - l, ",");
+          copy_option_part(&buf, NameBuff + l, MAXPATHL - l, ",");
         }
       }
     }
@@ -1587,7 +1587,7 @@ int vim_chdirfile(char *fname, CdCause cause)
     NameBuff[0] = NUL;
   }
 
-  if (pathcmp(dir, (char *)NameBuff, -1) == 0) {
+  if (pathcmp(dir, NameBuff, -1) == 0) {
     // nothing to do
     return OK;
   }
diff --git a/src/nvim/fileio.c b/src/nvim/fileio.c
index 6ebc382ab5..fb45157d9c 100644
--- a/src/nvim/fileio.c
+++ b/src/nvim/fileio.c
@@ -138,7 +138,7 @@ void filemess(buf_T *buf, char *name, char *s, int attr)
   if (msg_silent != 0) {
     return;
   }
-  add_quoted_fname((char *)IObuff, IOSIZE - 100, buf, (const char *)name);
+  add_quoted_fname(IObuff, IOSIZE - 100, buf, (const char *)name);
   // Avoid an over-long translation to cause trouble.
   xstrlcat(IObuff, s, IOSIZE);
   // For the first message may have to start a new line.
@@ -155,7 +155,7 @@ void filemess(buf_T *buf, char *name, char *s, int attr)
   msg_scroll = msg_scroll_save;
   msg_scrolled_ign = true;
   // may truncate the message to avoid a hit-return prompt
-  msg_outtrans_attr(msg_may_trunc(false, (char *)IObuff), attr);
+  msg_outtrans_attr(msg_may_trunc(false, IObuff), attr);
   msg_clr_eos();
   ui_flush();
   msg_scrolled_ign = false;
@@ -1758,7 +1758,7 @@ failed:
     }
 
     if (!filtering && !(flags & READ_DUMMY) && !silent) {
-      add_quoted_fname((char *)IObuff, IOSIZE, curbuf, (const char *)sfname);
+      add_quoted_fname(IObuff, IOSIZE, curbuf, (const char *)sfname);
       c = false;
 
 #ifdef UNIX
@@ -1823,7 +1823,7 @@ failed:
       msg_scrolled_ign = true;
 
       if (!read_stdin && !read_buffer) {
-        p = (char_u *)msg_trunc_attr((char *)IObuff, false, 0);
+        p = (char_u *)msg_trunc_attr(IObuff, false, 0);
       }
 
       if (read_stdin || read_buffer || restart_edit != 0
@@ -2615,21 +2615,21 @@ int buf_write(buf_T *buf, char *fname, char *sfname, linenr_T start, linenr_T en
         // arbitrary numbers).
         STRCPY(IObuff, fname);
         for (i = 4913;; i += 123) {
-          char *tail = path_tail((char *)IObuff);
+          char *tail = path_tail(IObuff);
           size_t size = (size_t)(tail - IObuff);
           snprintf(tail, IOSIZE - size, "%d", i);
-          if (!os_fileinfo_link((char *)IObuff, &file_info)) {
+          if (!os_fileinfo_link(IObuff, &file_info)) {
             break;
           }
         }
-        fd = os_open((char *)IObuff,
+        fd = os_open(IObuff,
                      O_CREAT|O_WRONLY|O_EXCL|O_NOFOLLOW, (int)perm);
         if (fd < 0) {           // can't write in directory
           backup_copy = true;
         } else {
 #ifdef UNIX
           os_fchown(fd, (uv_uid_t)file_info_old.stat.st_uid, (uv_gid_t)file_info_old.stat.st_gid);
-          if (!os_fileinfo((char *)IObuff, &file_info)
+          if (!os_fileinfo(IObuff, &file_info)
               || file_info.stat.st_uid != file_info_old.stat.st_uid
               || file_info.stat.st_gid != file_info_old.stat.st_gid
               || (long)file_info.stat.st_mode != perm) {
@@ -2639,7 +2639,7 @@ int buf_write(buf_T *buf, char *fname, char *sfname, linenr_T start, linenr_T en
           // Close the file before removing it, on MS-Windows we
           // can't delete an open file.
           close(fd);
-          os_remove((char *)IObuff);
+          os_remove(IObuff);
         }
       }
     }
@@ -2693,16 +2693,16 @@ int buf_write(buf_T *buf, char *fname, char *sfname, linenr_T start, linenr_T en
       dirp = p_bdir;
       while (*dirp) {
         // Isolate one directory name, using an entry in 'bdir'.
-        size_t dir_len = copy_option_part(&dirp, (char *)IObuff, IOSIZE, ",");
-        p = (char *)IObuff + dir_len;
-        bool trailing_pathseps = after_pathsep((char *)IObuff, p) && p[-1] == p[-2];
+        size_t dir_len = copy_option_part(&dirp, IObuff, IOSIZE, ",");
+        p = IObuff + dir_len;
+        bool trailing_pathseps = after_pathsep(IObuff, p) && p[-1] == p[-2];
         if (trailing_pathseps) {
           IObuff[dir_len - 2] = NUL;
         }
-        if (*dirp == NUL && !os_isdir((char *)IObuff)) {
+        if (*dirp == NUL && !os_isdir(IObuff)) {
           int ret;
           char *failed_dir;
-          if ((ret = os_mkdir_recurse((char *)IObuff, 0755, &failed_dir)) != 0) {
+          if ((ret = os_mkdir_recurse(IObuff, 0755, &failed_dir)) != 0) {
             semsg(_("E303: Unable to create directory \"%s\" for backup file: %s"),
                   failed_dir, os_strerror(ret));
             xfree(failed_dir);
@@ -2710,14 +2710,14 @@ int buf_write(buf_T *buf, char *fname, char *sfname, linenr_T start, linenr_T en
         }
         if (trailing_pathseps) {
           // Ends with '//', Use Full path
-          if ((p = make_percent_swname((char *)IObuff, fname))
+          if ((p = make_percent_swname(IObuff, fname))
               != NULL) {
             backup = modname(p, backup_ext, no_prepend_dot);
             xfree(p);
           }
         }
 
-        rootname = get_file_in_dir(fname, (char *)IObuff);
+        rootname = get_file_in_dir(fname, IObuff);
         if (rootname == NULL) {
           some_error = true;                // out of memory
           goto nobackup;
@@ -2844,16 +2844,16 @@ nobackup:
       dirp = p_bdir;
       while (*dirp) {
         // Isolate one directory name and make the backup file name.
-        size_t dir_len = copy_option_part(&dirp, (char *)IObuff, IOSIZE, ",");
-        p = (char *)IObuff + dir_len;
-        bool trailing_pathseps = after_pathsep((char *)IObuff, p) && p[-1] == p[-2];
+        size_t dir_len = copy_option_part(&dirp, IObuff, IOSIZE, ",");
+        p = IObuff + dir_len;
+        bool trailing_pathseps = after_pathsep(IObuff, p) && p[-1] == p[-2];
         if (trailing_pathseps) {
           IObuff[dir_len - 2] = NUL;
         }
-        if (*dirp == NUL && !os_isdir((char *)IObuff)) {
+        if (*dirp == NUL && !os_isdir(IObuff)) {
           int ret;
           char *failed_dir;
-          if ((ret = os_mkdir_recurse((char *)IObuff, 0755, &failed_dir)) != 0) {
+          if ((ret = os_mkdir_recurse(IObuff, 0755, &failed_dir)) != 0) {
             semsg(_("E303: Unable to create directory \"%s\" for backup file: %s"),
                   failed_dir, os_strerror(ret));
             xfree(failed_dir);
@@ -2861,7 +2861,7 @@ nobackup:
         }
         if (trailing_pathseps) {
           // path ends with '//', use full path
-          if ((p = make_percent_swname((char *)IObuff, fname))
+          if ((p = make_percent_swname(IObuff, fname))
               != NULL) {
             backup = modname(p, backup_ext, no_prepend_dot);
             xfree(p);
@@ -2869,7 +2869,7 @@ nobackup:
         }
 
         if (backup == NULL) {
-          rootname = get_file_in_dir(fname, (char *)IObuff);
+          rootname = get_file_in_dir(fname, IObuff);
           if (rootname == NULL) {
             backup = NULL;
           } else {
@@ -3419,13 +3419,13 @@ restore_backup:
   fname = sfname;           // use shortname now, for the messages
 #endif
   if (!filtering) {
-    add_quoted_fname((char *)IObuff, IOSIZE, buf, (const char *)fname);
+    add_quoted_fname(IObuff, IOSIZE, buf, (const char *)fname);
     c = false;
     if (write_info.bw_conv_error) {
       STRCAT(IObuff, _(" CONVERSION ERROR"));
       c = true;
       if (write_info.bw_conv_error_lnum != 0) {
-        vim_snprintf_add((char *)IObuff, IOSIZE, _(" in line %" PRId64 ";"),
+        vim_snprintf_add(IObuff, IOSIZE, _(" in line %" PRId64 ";"),
                          (int64_t)write_info.bw_conv_error_lnum);
       }
     } else if (notconverted) {
@@ -3459,7 +3459,7 @@ restore_backup:
       }
     }
 
-    set_keep_msg(msg_trunc_attr((char *)IObuff, false, 0), 0);
+    set_keep_msg(msg_trunc_attr(IObuff, false, 0), 0);
   }
 
   // When written everything correctly: reset 'modified'.  Unless not
@@ -3564,9 +3564,9 @@ nofail:
   if (errmsg != NULL) {
     // - 100 to save some space for further error message
 #ifndef UNIX
-    add_quoted_fname((char *)IObuff, IOSIZE - 100, buf, (const char *)sfname);
+    add_quoted_fname(IObuff, IOSIZE - 100, buf, (const char *)sfname);
 #else
-    add_quoted_fname((char *)IObuff, IOSIZE - 100, buf, (const char *)fname);
+    add_quoted_fname(IObuff, IOSIZE - 100, buf, (const char *)fname);
 #endif
     if (errnum != NULL) {
       if (errmsgarg != 0) {
@@ -5317,7 +5317,7 @@ int delete_recursive(const char *name)
     garray_T ga;
     if (readdir_core(&ga, exp, NULL, NULL) == OK) {
       for (int i = 0; i < ga.ga_len; i++) {
-        vim_snprintf((char *)NameBuff, MAXPATHL, "%s/%s", exp, ((char_u **)ga.ga_data)[i]);
+        vim_snprintf(NameBuff, MAXPATHL, "%s/%s", exp, ((char_u **)ga.ga_data)[i]);
         if (delete_recursive((const char *)NameBuff) != 0) {
           // Remember the failure but continue deleting any further
           // entries.
diff --git a/src/nvim/getchar.c b/src/nvim/getchar.c
index 5a2589cc66..b9e3b6b902 100644
--- a/src/nvim/getchar.c
+++ b/src/nvim/getchar.c
@@ -1275,7 +1275,7 @@ void openscript(char *name, bool directly)
   // use NameBuff for expanded name
   expand_env(name, NameBuff, MAXPATHL);
   int error;
-  if ((scriptin[curscript] = file_open_new(&error, (char *)NameBuff,
+  if ((scriptin[curscript] = file_open_new(&error, NameBuff,
                                            kFileReadOnly, 0)) == NULL) {
     semsg(_(e_notopen_2), name, os_strerror(error));
     if (curscript) {
diff --git a/src/nvim/help.c b/src/nvim/help.c
index af28c37910..0a695a0aa7 100644
--- a/src/nvim/help.c
+++ b/src/nvim/help.c
@@ -372,7 +372,7 @@ int find_help_tags(const char *arg, int *num_matches, char ***matches, bool keep
     "!=?", "!~?", "<=?", "<?", "==?", "=~?",
     ">=?", ">?", "is?", "isnot?"
   };
-  char *d = (char *)IObuff;       // assume IObuff is long enough!
+  char *d = IObuff;       // assume IObuff is long enough!
   d[0] = NUL;
 
   if (STRNICMP(arg, "expr-", 5) == 0) {
@@ -550,7 +550,7 @@ int find_help_tags(const char *arg, int *num_matches, char ***matches, bool keep
   if (keep_lang) {
     flags |= TAG_KEEP_LANG;
   }
-  if (find_tags((char *)IObuff, num_matches, matches, flags, MAXCOL, NULL) == OK
+  if (find_tags(IObuff, num_matches, matches, flags, MAXCOL, NULL) == OK
       && *num_matches > 0) {
     // Sort the matches found on the heuristic number that is after the
     // tag name.
@@ -716,10 +716,10 @@ void fix_help_buffer(void)
       // $VIMRUNTIME.
       char *p = p_rtp;
       while (*p != NUL) {
-        copy_option_part(&p, (char *)NameBuff, MAXPATHL, ",");
+        copy_option_part(&p, NameBuff, MAXPATHL, ",");
         char *const rt = vim_getenv("VIMRUNTIME");
         if (rt != NULL
-            && path_full_compare(rt, (char *)NameBuff, false, true) != kEqualFiles) {
+            && path_full_compare(rt, NameBuff, false, true) != kEqualFiles) {
           int fcount;
           char **fnames;
           char *s;
@@ -727,7 +727,7 @@ void fix_help_buffer(void)
           char *cp;
 
           // Find all "doc/ *.txt" files in this directory.
-          if (!add_pathsep((char *)NameBuff)
+          if (!add_pathsep(NameBuff)
               || xstrlcat(NameBuff, "doc/*.??[tx]",  // NOLINT
                           sizeof(NameBuff)) >= MAXPATHL) {
             emsg(_(e_fnametoolong));
@@ -736,7 +736,7 @@ void fix_help_buffer(void)
 
           // Note: We cannot just do `&NameBuff` because it is a statically sized array
           //       so `NameBuff == &NameBuff` according to C semantics.
-          char *buff_list[1] = { (char *)NameBuff };
+          char *buff_list[1] = { NameBuff };
           if (gen_expand_wildcards(1, buff_list, &fcount,
                                    &fnames, EW_FILE|EW_SILENT) == OK
               && fcount > 0) {
@@ -785,7 +785,7 @@ void fix_help_buffer(void)
               }
               vim_fgets(IObuff, IOSIZE, fd);
               if (IObuff[0] == '*'
-                  && (s = vim_strchr((char *)IObuff + 1, '*'))
+                  && (s = vim_strchr(IObuff + 1, '*'))
                   != NULL) {
                 TriState this_utf = kNone;
                 // Change tag definition to a
@@ -818,13 +818,13 @@ void fix_help_buffer(void)
                               p_enc);
                 if (vc.vc_type == CONV_NONE) {
                   // No conversion needed.
-                  cp = (char *)IObuff;
+                  cp = IObuff;
                 } else {
                   // Do the conversion.  If it fails
                   // use the unconverted text.
-                  cp = string_convert(&vc, (char *)IObuff, NULL);
+                  cp = string_convert(&vc, IObuff, NULL);
                   if (cp == NULL) {
-                    cp = (char *)IObuff;
+                    cp = IObuff;
                   }
                 }
                 convert_setup(&vc, NULL, NULL);
@@ -890,7 +890,7 @@ static void helptags_one(char *dir, const char *ext, const char *tagfname, bool
 
   // Note: We cannot just do `&NameBuff` because it is a statically sized array
   //       so `NameBuff == &NameBuff` according to C semantics.
-  char *buff_list[1] = { (char *)NameBuff };
+  char *buff_list[1] = { NameBuff };
   const int res = gen_expand_wildcards(1, buff_list, &filecount, &files,
                                        EW_FILE|EW_SILENT);
   if (res == FAIL || filecount == 0) {
@@ -906,13 +906,13 @@ static void helptags_one(char *dir, const char *ext, const char *tagfname, bool
   // Open the tags file for writing.
   // Do this before scanning through all the files.
   memcpy(NameBuff, dir, dirlen + 1);
-  if (!add_pathsep((char *)NameBuff)
+  if (!add_pathsep(NameBuff)
       || xstrlcat(NameBuff, tagfname, sizeof(NameBuff)) >= MAXPATHL) {
     emsg(_(e_fnametoolong));
     return;
   }
 
-  FILE *const fd_tags = os_fopen((char *)NameBuff, "w");
+  FILE *const fd_tags = os_fopen(NameBuff, "w");
   if (fd_tags == NULL) {
     if (!ignore_writeerr) {
       semsg(_("E152: Cannot open %s for writing"), NameBuff);
@@ -947,7 +947,7 @@ static void helptags_one(char *dir, const char *ext, const char *tagfname, bool
       if (firstline) {
         // Detect utf-8 file by a non-ASCII char in the first line.
         TriState this_utf8 = kNone;
-        for (s = (char *)IObuff; *s != NUL; s++) {
+        for (s = IObuff; *s != NUL; s++) {
           if ((char_u)(*s) >= 0x80) {
             this_utf8 = kTrue;
             const int l = utf_ptr2len(s);
@@ -1033,10 +1033,10 @@ static void helptags_one(char *dir, const char *ext, const char *tagfname, bool
       while (*p1 == *p2) {
         if (*p2 == '\t') {
           *p2 = NUL;
-          vim_snprintf((char *)NameBuff, MAXPATHL,
+          vim_snprintf(NameBuff, MAXPATHL,
                        _("E154: Duplicate tag \"%s\" in file %s/%s"),
                        ((char_u **)ga.ga_data)[i], dir, p2 + 1);
-          emsg((char *)NameBuff);
+          emsg(NameBuff);
           *p2 = '\t';
           break;
         }
@@ -1098,7 +1098,7 @@ static void do_helptags(char *dirname, bool add_help_tags, bool ignore_writeerr)
 
   // Note: We cannot just do `&NameBuff` because it is a statically sized array
   //       so `NameBuff == &NameBuff` according to C semantics.
-  char *buff_list[1] = { (char *)NameBuff };
+  char *buff_list[1] = { NameBuff };
   if (gen_expand_wildcards(1, buff_list, &filecount, &files,
                            EW_FILE|EW_SILENT) == FAIL
       || filecount == 0) {
diff --git a/src/nvim/insexpand.c b/src/nvim/insexpand.c
index 27d522d759..f2ee299211 100644
--- a/src/nvim/insexpand.c
+++ b/src/nvim/insexpand.c
@@ -653,7 +653,7 @@ static char_u *ins_compl_infercase_gettext(const char_u *str, int char_len, int
 
   // Generate encoding specific output from wide character array.
   garray_T gap;
-  char *p = (char *)IObuff;
+  char *p = IObuff;
   int i = 0;
   ga_init(&gap, 1, 500);
   while (i < char_len) {
@@ -662,7 +662,7 @@ static char_u *ins_compl_infercase_gettext(const char_u *str, int char_len, int
       assert(gap.ga_data != NULL);  // suppress clang "Dereference of NULL pointer"
       p = (char *)gap.ga_data + gap.ga_len;
       gap.ga_len += utf_char2bytes(wca[i++], p);
-    } else if ((p - (char *)IObuff) + 6 >= IOSIZE) {
+    } else if ((p - IObuff) + 6 >= IOSIZE) {
       // Multi-byte characters can occupy up to five bytes more than
       // ASCII characters, and we also need one byte for NUL, so when
       // getting to six bytes from the edge of IObuff switch to using a
@@ -1452,9 +1452,9 @@ static void ins_compl_files(int count, char **files, int thesaurus, int flags, r
     fp = os_fopen(files[i], "r");  // open dictionary file
     if (flags != DICT_EXACT && !shortmess(SHM_COMPLETIONSCAN)) {
       msg_hist_off = true;  // reset in msg_trunc_attr()
-      vim_snprintf((char *)IObuff, IOSIZE,
+      vim_snprintf(IObuff, IOSIZE,
                    _("Scanning dictionary: %s"), files[i]);
-      (void)msg_trunc_attr((char *)IObuff, true, HL_ATTR(HLF_R));
+      (void)msg_trunc_attr(IObuff, true, HL_ATTR(HLF_R));
     }
 
     if (fp == NULL) {
@@ -2880,13 +2880,13 @@ static int process_next_cpt_value(ins_compl_next_state_T *st, int *compl_type_ar
     }
     if (!shortmess(SHM_COMPLETIONSCAN)) {
       msg_hist_off = true;  // reset in msg_trunc_attr()
-      vim_snprintf((char *)IObuff, IOSIZE, _("Scanning: %s"),
+      vim_snprintf(IObuff, IOSIZE, _("Scanning: %s"),
                    st->ins_buf->b_fname == NULL
                    ? buf_spname(st->ins_buf)
                    : st->ins_buf->b_sfname == NULL
                    ? st->ins_buf->b_fname
                    : st->ins_buf->b_sfname);
-      (void)msg_trunc_attr((char *)IObuff, true, HL_ATTR(HLF_R));
+      (void)msg_trunc_attr(IObuff, true, HL_ATTR(HLF_R));
     }
   } else if (*st->e_cpt == NUL) {
     status = INS_COMPL_CPT_END;
@@ -2911,15 +2911,15 @@ static int process_next_cpt_value(ins_compl_next_state_T *st, int *compl_type_ar
       compl_type = CTRL_X_TAGS;
       if (!shortmess(SHM_COMPLETIONSCAN)) {
         msg_hist_off = true;  // reset in msg_trunc_attr()
-        vim_snprintf((char *)IObuff, IOSIZE, "%s", _("Scanning tags."));
-        (void)msg_trunc_attr((char *)IObuff, true, HL_ATTR(HLF_R));
+        vim_snprintf(IObuff, IOSIZE, "%s", _("Scanning tags."));
+        (void)msg_trunc_attr(IObuff, true, HL_ATTR(HLF_R));
       }
     } else {
       compl_type = -1;
     }
 
     // in any case e_cpt is advanced to the next entry
-    (void)copy_option_part(&st->e_cpt, (char *)IObuff, IOSIZE, ",");
+    (void)copy_option_part(&st->e_cpt, IObuff, IOSIZE, ",");
 
     st->found_all = true;
     if (compl_type == -1) {
@@ -3019,7 +3019,7 @@ static void get_next_cmdline_completion(void)
 {
   char **matches;
   int num_matches;
-  if (expand_cmdline(&compl_xp, (char_u *)compl_pattern,
+  if (expand_cmdline(&compl_xp, compl_pattern,
                      (int)strlen(compl_pattern),
                      &num_matches, &matches) == EXPAND_OK) {
     ins_compl_add_matches(num_matches, matches, false);
@@ -3067,7 +3067,7 @@ static char_u *ins_comp_get_next_word_or_line(buf_T *ins_buf, pos_T *cur_match_p
     if (compl_status_adding() && compl_length <= (int)strlen(tmp_ptr)) {
       tmp_ptr += compl_length;
       // Skip if already inside a word.
-      if (vim_iswordp((char_u *)tmp_ptr)) {
+      if (vim_iswordp(tmp_ptr)) {
         return NULL;
       }
       // Find start of next word.
@@ -3483,9 +3483,9 @@ static void ins_compl_show_filename(void)
     }
   }
   msg_hist_off = true;
-  vim_snprintf((char *)IObuff, IOSIZE, "%s %s%s", lead,
+  vim_snprintf(IObuff, IOSIZE, "%s %s%s", lead,
                s > compl_shown_match->cp_fname ? "<" : "", s);
-  msg((char *)IObuff);
+  msg(IObuff);
   msg_hist_off = false;
   redraw_cmdline = false;  // don't overwrite!
 }
@@ -3824,7 +3824,7 @@ static int get_normal_compl_info(char *line, int startcol, colnr_T curs_col)
       compl_length = curs_col - startcol;
     }
     if (p_ic) {
-      compl_pattern = (char *)str_foldcase((char_u *)line + compl_col, compl_length, NULL, 0);
+      compl_pattern = str_foldcase(line + compl_col, compl_length, NULL, 0);
     } else {
       compl_pattern = xstrnsave(line + compl_col, (size_t)compl_length);
     }
@@ -3833,16 +3833,16 @@ static int get_normal_compl_info(char *line, int startcol, colnr_T curs_col)
 
     // we need up to 2 extra chars for the prefix
     compl_pattern = xmalloc(quote_meta(NULL, (char_u *)line + compl_col, compl_length) + 2);
-    if (!vim_iswordp((char_u *)line + compl_col)
+    if (!vim_iswordp(line + compl_col)
         || (compl_col > 0
-            && (vim_iswordp(mb_prevptr((char_u *)line, (char_u *)line + compl_col))))) {
+            && (vim_iswordp((char *)mb_prevptr((char_u *)line, (char_u *)line + compl_col))))) {
       prefix = "";
     }
     STRCPY(compl_pattern, prefix);
     (void)quote_meta((char_u *)compl_pattern + strlen(prefix),
                      (char_u *)line + compl_col, compl_length);
   } else if (--startcol < 0
-             || !vim_iswordp(mb_prevptr((char_u *)line, (char_u *)line + startcol + 1))) {
+             || !vim_iswordp((char *)mb_prevptr((char_u *)line, (char_u *)line + startcol + 1))) {
     // Match any word of at least two chars
     compl_pattern = xstrdup("\\<\\k\\k");
     compl_col += curs_col;
@@ -3891,7 +3891,7 @@ static int get_wholeline_compl_info(char *line, colnr_T curs_col)
     compl_length = 0;
   }
   if (p_ic) {
-    compl_pattern = (char *)str_foldcase((char_u *)line + compl_col, compl_length, NULL, 0);
+    compl_pattern = str_foldcase(line + compl_col, compl_length, NULL, 0);
   } else {
     compl_pattern = xstrnsave(line + compl_col, (size_t)compl_length);
   }
diff --git a/src/nvim/lua/executor.c b/src/nvim/lua/executor.c
index cd022068ce..12ddbd094f 100644
--- a/src/nvim/lua/executor.c
+++ b/src/nvim/lua/executor.c
@@ -1052,8 +1052,8 @@ static int nlua_require(lua_State *const lstate)
   time_push(&rel_time, &start_time);
   int status = lua_pcall(lstate, 1, 1, 0);
   if (status == 0) {
-    vim_snprintf((char *)IObuff, IOSIZE, "require('%s')", name);
-    time_msg((char *)IObuff, &start_time);
+    vim_snprintf(IObuff, IOSIZE, "require('%s')", name);
+    time_msg(IObuff, &start_time);
   }
   time_pop(rel_time);
 
@@ -1342,7 +1342,7 @@ void nlua_typval_eval(const String str, typval_T *const arg, typval_T *const ret
   const size_t lcmd_len = sizeof(EVALHEADER) - 1 + str.size + 1;
   char *lcmd;
   if (lcmd_len < IOSIZE) {
-    lcmd = (char *)IObuff;
+    lcmd = IObuff;
   } else {
     lcmd = xmalloc(lcmd_len);
   }
@@ -1352,7 +1352,7 @@ void nlua_typval_eval(const String str, typval_T *const arg, typval_T *const ret
 #undef EVALHEADER
   nlua_typval_exec(lcmd, lcmd_len, "luaeval()", arg, 1, true, ret_tv);
 
-  if (lcmd != (char *)IObuff) {
+  if (lcmd != IObuff) {
     xfree(lcmd);
   }
 }
@@ -1366,7 +1366,7 @@ void nlua_typval_call(const char *str, size_t len, typval_T *const args, int arg
   const size_t lcmd_len = sizeof(CALLHEADER) - 1 + len + sizeof(CALLSUFFIX) - 1;
   char *lcmd;
   if (lcmd_len < IOSIZE) {
-    lcmd = (char *)IObuff;
+    lcmd = IObuff;
   } else {
     lcmd = xmalloc(lcmd_len);
   }
@@ -1379,7 +1379,7 @@ void nlua_typval_call(const char *str, size_t len, typval_T *const args, int arg
 
   nlua_typval_exec(lcmd, lcmd_len, "v:lua", args, argcount, false, ret_tv);
 
-  if (lcmd != (char *)IObuff) {
+  if (lcmd != IObuff) {
     xfree(lcmd);
   }
 }
@@ -1645,7 +1645,7 @@ void ex_luado(exarg_T *const eap)
                            + (sizeof(DOEND) - 1));
   char *lcmd;
   if (lcmd_len < IOSIZE) {
-    lcmd = (char *)IObuff;
+    lcmd = IObuff;
   } else {
     lcmd = xmalloc(lcmd_len + 1);
   }
diff --git a/src/nvim/lua/treesitter.c b/src/nvim/lua/treesitter.c
index d77e210c6a..fecf746036 100644
--- a/src/nvim/lua/treesitter.c
+++ b/src/nvim/lua/treesitter.c
@@ -182,19 +182,19 @@ int tslua_add_language(lua_State *L)
 
   uv_lib_t lib;
   if (uv_dlopen(path, &lib)) {
-    snprintf((char *)IObuff, IOSIZE, "Failed to load parser: uv_dlopen: %s",
+    snprintf(IObuff, IOSIZE, "Failed to load parser: uv_dlopen: %s",
              uv_dlerror(&lib));
     uv_dlclose(&lib);
-    lua_pushstring(L, (char *)IObuff);
+    lua_pushstring(L, IObuff);
     return lua_error(L);
   }
 
   TSLanguage *(*lang_parser)(void);
   if (uv_dlsym(&lib, symbol_buf, (void **)&lang_parser)) {
-    snprintf((char *)IObuff, IOSIZE, "Failed to load parser: uv_dlsym: %s",
+    snprintf(IObuff, IOSIZE, "Failed to load parser: uv_dlsym: %s",
              uv_dlerror(&lib));
     uv_dlclose(&lib);
-    lua_pushstring(L, (char *)IObuff);
+    lua_pushstring(L, IObuff);
     return lua_error(L);
   }
 
diff --git a/src/nvim/main.c b/src/nvim/main.c
index 953385836b..048fdd4052 100644
--- a/src/nvim/main.c
+++ b/src/nvim/main.c
@@ -1336,7 +1336,7 @@ static void command_line_scan(mparm_T *parmp)
         case 's':    // "-s {scriptin}" read from script file
           if (parmp->scriptin != NULL) {
 scripterror:
-            vim_snprintf((char *)IObuff, IOSIZE,
+            vim_snprintf(IObuff, IOSIZE,
                          _("Attempt to open script file again: \"%s %s\"\n"),
                          argv[-1], argv[0]);
             os_errmsg(IObuff);
@@ -1514,8 +1514,8 @@ static void handle_quickfix(mparm_T *paramp)
     if (paramp->use_ef != NULL) {
       set_string_option_direct("ef", -1, paramp->use_ef, OPT_FREE, SID_CARG);
     }
-    vim_snprintf((char *)IObuff, IOSIZE, "cfile %s", p_ef);
-    if (qf_init(NULL, (char *)p_ef, p_efm, true, (char *)IObuff, p_menc) < 0) {
+    vim_snprintf(IObuff, IOSIZE, "cfile %s", p_ef);
+    if (qf_init(NULL, (char *)p_ef, p_efm, true, IObuff, p_menc) < 0) {
       msg_putchar('\n');
       os_exit(3);
     }
@@ -1530,8 +1530,8 @@ static void handle_tag(char_u *tagname)
   if (tagname != NULL) {
     swap_exists_did_quit = false;
 
-    vim_snprintf((char *)IObuff, IOSIZE, "ta %s", tagname);
-    do_cmdline_cmd((char *)IObuff);
+    vim_snprintf(IObuff, IOSIZE, "ta %s", tagname);
+    do_cmdline_cmd(IObuff);
     TIME_MSG("jumping to tag");
 
     // If the user doesn't want to edit the file then we quit here.
diff --git a/src/nvim/mapping.c b/src/nvim/mapping.c
index 199cc7b369..757855c350 100644
--- a/src/nvim/mapping.c
+++ b/src/nvim/mapping.c
@@ -589,13 +589,13 @@ static int buf_do_map(int maptype, MapArguments *args, int mode, bool is_abbrev,
         // vi-compatible way.
         int same = -1;
 
-        const int first = vim_iswordp((char_u *)lhs);
+        const int first = vim_iswordp(lhs);
         int last = first;
         p = (char *)lhs + utfc_ptr2len((char *)lhs);
         n = 1;
         while (p < (char *)lhs + len) {
           n++;                                  // nr of (multi-byte) chars
-          last = vim_iswordp((char_u *)p);                // type of last char
+          last = vim_iswordp(p);                // type of last char
           if (same == -1 && last != first) {
             same = n - 1;                       // count of same char type
           }
@@ -1419,18 +1419,18 @@ bool check_abbr(int c, char *ptr, int col, int mincol)
   {
     bool vim_abbr;
     char_u *p = mb_prevptr((char_u *)ptr, (char_u *)ptr + col);
-    if (!vim_iswordp(p)) {
+    if (!vim_iswordp((char *)p)) {
       vim_abbr = true;    // Vim added abbr.
     } else {
       vim_abbr = false;   // vi compatible abbr.
       if (p > (char_u *)ptr) {
-        is_id = vim_iswordp(mb_prevptr((char_u *)ptr, p));
+        is_id = vim_iswordp((char *)mb_prevptr((char_u *)ptr, p));
       }
     }
     clen = 1;
     while (p > (char_u *)ptr + mincol) {
       p = mb_prevptr((char_u *)ptr, p);
-      if (ascii_isspace(*p) || (!vim_abbr && is_id != vim_iswordp(p))) {
+      if (ascii_isspace(*p) || (!vim_abbr && is_id != vim_iswordp((char *)p))) {
         p += utfc_ptr2len((char *)p);
         break;
       }
diff --git a/src/nvim/mark.c b/src/nvim/mark.c
index 0d4a95ebab..af3f1e3679 100644
--- a/src/nvim/mark.c
+++ b/src/nvim/mark.c
@@ -899,8 +899,8 @@ static void show_one_mark(int c, char_u *arg, pos_T *p, char_u *name_arg, int cu
       }
       msg_putchar('\n');
       if (!got_int) {
-        snprintf((char *)IObuff, IOSIZE, " %c %6" PRIdLINENR " %4d ", c, p->lnum, p->col);
-        msg_outtrans((char *)IObuff);
+        snprintf(IObuff, IOSIZE, " %c %6" PRIdLINENR " %4d ", c, p->lnum, p->col);
+        msg_outtrans(IObuff);
         if (name != NULL) {
           msg_outtrans_attr((char *)name, current ? HL_ATTR(HLF_D) : 0);
         }
@@ -1022,11 +1022,11 @@ void ex_jumps(exarg_T *eap)
         xfree(name);
         break;
       }
-      snprintf((char *)IObuff, IOSIZE, "%c %2d %5" PRIdLINENR " %4d ",
+      snprintf(IObuff, IOSIZE, "%c %2d %5" PRIdLINENR " %4d ",
                i == curwin->w_jumplistidx ? '>' : ' ',
                i > curwin->w_jumplistidx ? i - curwin->w_jumplistidx : curwin->w_jumplistidx - i,
                curwin->w_jumplist[i].fmark.mark.lnum, curwin->w_jumplist[i].fmark.mark.col);
-      msg_outtrans((char *)IObuff);
+      msg_outtrans(IObuff);
       msg_outtrans_attr(name,
                         curwin->w_jumplist[i].fmark.fnum == curbuf->b_fnum
                         ? HL_ATTR(HLF_D) : 0);
@@ -1066,7 +1066,7 @@ void ex_changes(exarg_T *eap)
                i > curwin->w_changelistidx ? i - curwin->w_changelistidx : curwin->w_changelistidx - i,
                (long)curbuf->b_changelist[i].mark.lnum,
                curbuf->b_changelist[i].mark.col);
-      msg_outtrans((char *)IObuff);
+      msg_outtrans(IObuff);
       name = (char_u *)mark_line(&curbuf->b_changelist[i].mark, 17);
       msg_outtrans_attr((char *)name, HL_ATTR(HLF_D));
       xfree(name);
diff --git a/src/nvim/mbyte.c b/src/nvim/mbyte.c
index 450b84dced..e1a870071c 100644
--- a/src/nvim/mbyte.c
+++ b/src/nvim/mbyte.c
@@ -1557,7 +1557,7 @@ void show_utf8(void)
       }
       clen = utf_ptr2len((char *)line + i);
     }
-    sprintf((char *)IObuff + rlen, "%02x ",  // NOLINT(runtime/printf)
+    sprintf(IObuff + rlen, "%02x ",  // NOLINT(runtime/printf)
             (line[i] == NL) ? NUL : line[i]);          // NUL is stored as NL
     clen--;
     rlen += (int)strlen(IObuff + rlen);
@@ -1566,7 +1566,7 @@ void show_utf8(void)
     }
   }
 
-  msg((char *)IObuff);
+  msg(IObuff);
 }
 
 /// Return offset from "p" to the start of a character, including composing characters.
diff --git a/src/nvim/memline.c b/src/nvim/memline.c
index 8d92b30959..33223f6d1e 100644
--- a/src/nvim/memline.c
+++ b/src/nvim/memline.c
@@ -887,18 +887,18 @@ void ml_recover(bool checkext)
   // If .swp file name given directly, use name from swap file for buffer.
   if (directly) {
     expand_env((char *)b0p->b0_fname, NameBuff, MAXPATHL);
-    if (setfname(curbuf, (char *)NameBuff, NULL, true) == FAIL) {
+    if (setfname(curbuf, NameBuff, NULL, true) == FAIL) {
       goto theend;
     }
   }
 
-  home_replace(NULL, mfp->mf_fname, (char *)NameBuff, MAXPATHL, true);
+  home_replace(NULL, mfp->mf_fname, NameBuff, MAXPATHL, true);
   smsg(_("Using swap file \"%s\""), NameBuff);
 
   if (buf_spname(curbuf) != NULL) {
     xstrlcpy(NameBuff, buf_spname(curbuf), MAXPATHL);
   } else {
-    home_replace(NULL, curbuf->b_ffname, (char *)NameBuff, MAXPATHL, true);
+    home_replace(NULL, curbuf->b_ffname, NameBuff, MAXPATHL, true);
   }
   smsg(_("Original file \"%s\""), NameBuff);
   msg_putchar('\n');
diff --git a/src/nvim/message.c b/src/nvim/message.c
index 8eea09ed13..e9d66ea184 100644
--- a/src/nvim/message.c
+++ b/src/nvim/message.c
@@ -491,10 +491,10 @@ int smsg(const char *s, ...)
   va_list arglist;
 
   va_start(arglist, s);
-  vim_vsnprintf((char *)IObuff, IOSIZE, s, arglist);
+  vim_vsnprintf(IObuff, IOSIZE, s, arglist);
   va_end(arglist);
 
-  return msg((char *)IObuff);
+  return msg(IObuff);
 }
 
 int smsg_attr(int attr, const char *s, ...)
@@ -503,7 +503,7 @@ int smsg_attr(int attr, const char *s, ...)
   va_list arglist;
 
   va_start(arglist, s);
-  vim_vsnprintf((char *)IObuff, IOSIZE, s, arglist);
+  vim_vsnprintf(IObuff, IOSIZE, s, arglist);
   va_end(arglist);
   return msg_attr((const char *)IObuff, attr);
 }
@@ -514,7 +514,7 @@ int smsg_attr_keep(int attr, const char *s, ...)
   va_list arglist;
 
   va_start(arglist, s);
-  vim_vsnprintf((char *)IObuff, IOSIZE, s, arglist);
+  vim_vsnprintf(IObuff, IOSIZE, s, arglist);
   va_end(arglist);
   return msg_attr_keep((const char *)IObuff, attr, true, false);
 }
@@ -881,10 +881,10 @@ void msg_schedule_semsg(const char *const fmt, ...)
 {
   va_list ap;
   va_start(ap, fmt);
-  vim_vsnprintf((char *)IObuff, IOSIZE, fmt, ap);
+  vim_vsnprintf(IObuff, IOSIZE, fmt, ap);
   va_end(ap);
 
-  char *s = xstrdup((char *)IObuff);
+  char *s = xstrdup(IObuff);
   loop_schedule_deferred(&main_loop, event_create(msg_semsg_event, 1, s));
 }
 
@@ -3447,8 +3447,8 @@ void give_warning(char *message, bool hl)
 
 void give_warning2(char *const message, char *const a1, bool hl)
 {
-  vim_snprintf((char *)IObuff, IOSIZE, message, a1);
-  give_warning((char *)IObuff, hl);
+  vim_snprintf(IObuff, IOSIZE, message, a1);
+  give_warning(IObuff, hl);
 }
 
 /// Advance msg cursor to column "col".
diff --git a/src/nvim/normal.c b/src/nvim/normal.c
index 7979d2502e..6da71a9354 100644
--- a/src/nvim/normal.c
+++ b/src/nvim/normal.c
@@ -2285,7 +2285,7 @@ bool find_decl(char_u *ptr, size_t len, bool locally, bool thisblock, int flags_
   // Put "\V" before the pattern to avoid that the special meaning of "."
   // and "~" causes trouble.
   assert(len <= INT_MAX);
-  sprintf((char *)pat, vim_iswordp(ptr) ? "\\V\\<%.*s\\>" : "\\V%.*s",  // NOLINT(runtime/printf)
+  sprintf((char *)pat, vim_iswordp((char *)ptr) ? "\\V\\<%.*s\\>" : "\\V%.*s",  // NOLINT(runtime/printf)
           (int)len, ptr);
   old_pos = curwin->w_cursor;
   save_p_ws = p_ws;
@@ -3467,7 +3467,7 @@ static void nv_ident(cmdarg_T *cap)
     setpcmark();
     curwin->w_cursor.col = (colnr_T)(ptr - get_cursor_line_ptr());
 
-    if (!g_cmd && vim_iswordp((char_u *)ptr)) {
+    if (!g_cmd && vim_iswordp(ptr)) {
       STRCPY(buf, "\\<");
     }
     no_smartcase = true;                // don't use 'smartcase' now
@@ -3549,7 +3549,7 @@ static void nv_ident(cmdarg_T *cap)
   // Execute the command.
   if (cmdchar == '*' || cmdchar == '#') {
     if (!g_cmd
-        && vim_iswordp(mb_prevptr((char_u *)get_cursor_line_ptr(), (char_u *)ptr))) {
+        && vim_iswordp((char *)mb_prevptr((char_u *)get_cursor_line_ptr(), (char_u *)ptr))) {
       STRCAT(buf, "\\>");
     }
 
diff --git a/src/nvim/ops.c b/src/nvim/ops.c
index 2566108618..ec3ceca5bc 100644
--- a/src/nvim/ops.c
+++ b/src/nvim/ops.c
@@ -264,10 +264,10 @@ void op_shift(oparg_T *oap, int curs_top, int amount)
                                      "%" PRId64 " line %sed %d times", amount);
     char *msg_line_plural = NGETTEXT("%" PRId64 " lines %sed %d time",
                                      "%" PRId64 " lines %sed %d times", amount);
-    vim_snprintf((char *)IObuff, IOSIZE,
+    vim_snprintf(IObuff, IOSIZE,
                  NGETTEXT(msg_line_single, msg_line_plural, oap->line_count),
                  (int64_t)oap->line_count, op, amount);
-    msg_attr_keep((char *)IObuff, 0, true, false);
+    msg_attr_keep(IObuff, 0, true, false);
   }
 
   if ((cmdmod.cmod_flags & CMOD_LOCKMARKS) == 0) {
@@ -5467,7 +5467,7 @@ void cursor_pos_info(dict_T *dict)
 
         if (char_count_cursor == byte_count_cursor
             && char_count == byte_count) {
-          vim_snprintf((char *)IObuff, IOSIZE,
+          vim_snprintf(IObuff, IOSIZE,
                        _("Selected %s%" PRId64 " of %" PRId64 " Lines;"
                          " %" PRId64 " of %" PRId64 " Words;"
                          " %" PRId64 " of %" PRId64 " Bytes"),
@@ -5476,7 +5476,7 @@ void cursor_pos_info(dict_T *dict)
                        (int64_t)word_count_cursor, (int64_t)word_count,
                        (int64_t)byte_count_cursor, (int64_t)byte_count);
         } else {
-          vim_snprintf((char *)IObuff, IOSIZE,
+          vim_snprintf(IObuff, IOSIZE,
                        _("Selected %s%" PRId64 " of %" PRId64 " Lines;"
                          " %" PRId64 " of %" PRId64 " Words;"
                          " %" PRId64 " of %" PRId64 " Chars;"
@@ -5496,7 +5496,7 @@ void cursor_pos_info(dict_T *dict)
 
         if (char_count_cursor == byte_count_cursor
             && char_count == byte_count) {
-          vim_snprintf((char *)IObuff, IOSIZE,
+          vim_snprintf(IObuff, IOSIZE,
                        _("Col %s of %s; Line %" PRId64 " of %" PRId64 ";"
                          " Word %" PRId64 " of %" PRId64 ";"
                          " Byte %" PRId64 " of %" PRId64 ""),
@@ -5506,7 +5506,7 @@ void cursor_pos_info(dict_T *dict)
                        (int64_t)word_count_cursor, (int64_t)word_count,
                        (int64_t)byte_count_cursor, (int64_t)byte_count);
         } else {
-          vim_snprintf((char *)IObuff, IOSIZE,
+          vim_snprintf(IObuff, IOSIZE,
                        _("Col %s of %s; Line %" PRId64 " of %" PRId64 ";"
                          " Word %" PRId64 " of %" PRId64 ";"
                          " Char %" PRId64 " of %" PRId64 ";"
@@ -5524,7 +5524,7 @@ void cursor_pos_info(dict_T *dict)
     bom_count = bomb_size();
     if (dict == NULL && bom_count > 0) {
       const size_t len = strlen(IObuff);
-      vim_snprintf((char *)IObuff + len, IOSIZE - len,
+      vim_snprintf(IObuff + len, IOSIZE - len,
                    _("(+%" PRId64 " for BOM)"), (int64_t)bom_count);
     }
     if (dict == NULL) {
@@ -5535,7 +5535,7 @@ void cursor_pos_info(dict_T *dict)
         msg_start();
         msg_scroll = true;
       }
-      msg((char *)IObuff);
+      msg(IObuff);
       p_shm = p;
     }
   }
diff --git a/src/nvim/option.c b/src/nvim/option.c
index 06de8be129..a6ec0a08c2 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -1465,10 +1465,10 @@ skip:
         IObuff[i + (arg - startarg)] = NUL;
       }
       // make sure all characters are printable
-      trans_characters((char *)IObuff, IOSIZE);
+      trans_characters(IObuff, IOSIZE);
 
       no_wait_return++;         // wait_return() done later
-      emsg((char *)IObuff);     // show error highlighted
+      emsg(IObuff);             // show error highlighted
       no_wait_return--;
 
       return FAIL;
@@ -3159,7 +3159,7 @@ static void showoptions(int all, int opt_flags)
           len = 1;                      // a toggle option fits always
         } else {
           option_value2string(p, opt_flags);
-          len = (int)strlen(p->fullname) + vim_strsize((char *)NameBuff) + 1;
+          len = (int)strlen(p->fullname) + vim_strsize(NameBuff) + 1;
         }
         if ((len <= INC - GAP && run == 1)
             || (len > INC - GAP && run == 2)) {
@@ -3270,7 +3270,7 @@ static void showoneopt(vimoption_T *p, int opt_flags)
     msg_putchar('=');
     // put value string in NameBuff
     option_value2string(p, opt_flags);
-    msg_outtrans((char *)NameBuff);
+    msg_outtrans(NameBuff);
   }
 
   silent_mode = save_silent;
@@ -4808,7 +4808,7 @@ static void option_value2string(vimoption_T *opp, int scope)
     } else if (wc != 0) {
       xstrlcpy(NameBuff, (char *)transchar((int)wc), sizeof(NameBuff));
     } else {
-      snprintf((char *)NameBuff,
+      snprintf(NameBuff,
                sizeof(NameBuff),
                "%" PRId64,
                (int64_t)(*(long *)varp));
@@ -4821,7 +4821,7 @@ static void option_value2string(vimoption_T *opp, int scope)
       home_replace(NULL, varp, (char *)NameBuff, MAXPATHL, false);
       // Translate 'pastetoggle' into special key names.
     } else if ((char **)opp->var == &p_pt) {
-      str2specialbuf((const char *)p_pt, (char *)NameBuff, MAXPATHL);
+      str2specialbuf((const char *)p_pt, NameBuff, MAXPATHL);
     } else {
       xstrlcpy(NameBuff, varp, MAXPATHL);
     }
diff --git a/src/nvim/os/signal.c b/src/nvim/os/signal.c
index 08d24d47e2..b8daaabba2 100644
--- a/src/nvim/os/signal.c
+++ b/src/nvim/os/signal.c
@@ -172,7 +172,7 @@ static void deadly_signal(int signum)
 
   ILOG("got signal %d (%s)", signum, signal_name(signum));
 
-  snprintf((char *)IObuff, sizeof(IObuff), "Vim: Caught deadly signal '%s'\r\n",
+  snprintf(IObuff, sizeof(IObuff), "Vim: Caught deadly signal '%s'\r\n",
            signal_name(signum));
 
   // Preserve files and exit.
diff --git a/src/nvim/path.c b/src/nvim/path.c
index 0905c16e39..c78b899636 100644
--- a/src/nvim/path.c
+++ b/src/nvim/path.c
@@ -2442,8 +2442,8 @@ void path_guess_exepath(const char *argv0, char *buf, size_t bufsize)
       xstrlcpy(NameBuff, dir, dir_len + 1);
       xstrlcat(NameBuff, PATHSEPSTR, sizeof(NameBuff));
       xstrlcat(NameBuff, argv0, sizeof(NameBuff));
-      if (os_can_exe((char *)NameBuff, NULL, false)) {
-        xstrlcpy(buf, (char *)NameBuff, bufsize);
+      if (os_can_exe(NameBuff, NULL, false)) {
+        xstrlcpy(buf, NameBuff, bufsize);
         return;
       }
     } while (iter != NULL);
diff --git a/src/nvim/quickfix.c b/src/nvim/quickfix.c
index 63a6dcec50..7d7bf9d8ba 100644
--- a/src/nvim/quickfix.c
+++ b/src/nvim/quickfix.c
@@ -673,7 +673,7 @@ static int qf_get_next_str_line(qfstate_T *state)
   if (len > IOSIZE - 2) {
     state->linebuf = qf_grow_linebuf(state, len);
   } else {
-    state->linebuf = (char *)IObuff;
+    state->linebuf = IObuff;
     state->linelen = len;
   }
   memcpy(state->linebuf, p_str, state->linelen);
@@ -708,7 +708,7 @@ static int qf_get_next_list_line(qfstate_T *state)
   if (len > IOSIZE - 2) {
     state->linebuf = qf_grow_linebuf(state, len);
   } else {
-    state->linebuf = (char *)IObuff;
+    state->linebuf = IObuff;
     state->linelen = len;
   }
 
@@ -733,7 +733,7 @@ static int qf_get_next_buf_line(qfstate_T *state)
   if (len > IOSIZE - 2) {
     state->linebuf = qf_grow_linebuf(state, len);
   } else {
-    state->linebuf = (char *)IObuff;
+    state->linebuf = IObuff;
     state->linelen = len;
   }
   xstrlcpy(state->linebuf, p_buf, state->linelen + 1);
@@ -746,7 +746,7 @@ static int qf_get_next_file_line(qfstate_T *state)
 {
 retry:
   errno = 0;
-  if (fgets((char *)IObuff, IOSIZE, state->fd) == NULL) {
+  if (fgets(IObuff, IOSIZE, state->fd) == NULL) {
     if (errno == EINTR) {
       goto retry;
     }
@@ -796,7 +796,7 @@ retry:
       // The current line is longer than LINE_MAXLEN, continue reading but
       // discard everything until EOL or EOF is reached.
       errno = 0;
-      if (fgets((char *)IObuff, IOSIZE, state->fd) == NULL) {
+      if (fgets(IObuff, IOSIZE, state->fd) == NULL) {
         if (errno == EINTR) {
           continue;
         }
@@ -810,7 +810,7 @@ retry:
     state->linebuf = state->growbuf;
     state->linelen = growbuflen;
   } else {
-    state->linebuf = (char *)IObuff;
+    state->linebuf = IObuff;
   }
 
   // Convert a line if it contains a non-ASCII character
@@ -2803,13 +2803,13 @@ static void qf_jump_print_msg(qf_info_T *qi, int qf_index, qfline_T *qf_ptr, buf
       update_screen();
     }
   }
-  snprintf((char *)IObuff, IOSIZE, _("(%d of %d)%s%s: "), qf_index,
+  snprintf(IObuff, IOSIZE, _("(%d of %d)%s%s: "), qf_index,
            qf_get_curlist(qi)->qf_count,
            qf_ptr->qf_cleared ? _(" (line deleted)") : "",
            qf_types(qf_ptr->qf_type, qf_ptr->qf_nr));
   // Add the message, skipping leading whitespace and newlines.
   int len = (int)strlen(IObuff);
-  qf_fmt_text(skipwhite(qf_ptr->qf_text), (char *)IObuff + len, IOSIZE - len);
+  qf_fmt_text(skipwhite(qf_ptr->qf_text), IObuff + len, IOSIZE - len);
 
   // Output the message.  Overwrite to avoid scrolling when the 'O'
   // flag is present in 'shortmess'; But when not jumping, print the
@@ -2821,7 +2821,7 @@ static void qf_jump_print_msg(qf_info_T *qi, int qf_index, qfline_T *qf_ptr, buf
     msg_scroll = false;
   }
   msg_ext_set_kind("quickfix");
-  msg_attr_keep((char *)IObuff, 0, true, false);
+  msg_attr_keep(IObuff, 0, true, false);
   msg_scroll = (int)i;
 }
 
@@ -3039,7 +3039,7 @@ static void qf_list_entry(qfline_T *qfp, int qf_idx, bool cursel)
 {
   char *fname = NULL;
   if (qfp->qf_module != NULL && *qfp->qf_module != NUL) {
-    vim_snprintf((char *)IObuff, IOSIZE, "%2d %s", qf_idx, qfp->qf_module);
+    vim_snprintf(IObuff, IOSIZE, "%2d %s", qf_idx, qfp->qf_module);
   } else {
     buf_T *buf;
     if (qfp->qf_fnum != 0
@@ -3050,9 +3050,9 @@ static void qf_list_entry(qfline_T *qfp, int qf_idx, bool cursel)
       }
     }
     if (fname == NULL) {
-      snprintf((char *)IObuff, IOSIZE, "%2d", qf_idx);
+      snprintf(IObuff, IOSIZE, "%2d", qf_idx);
     } else {
-      vim_snprintf((char *)IObuff, IOSIZE, "%2d %s", qf_idx, fname);
+      vim_snprintf(IObuff, IOSIZE, "%2d %s", qf_idx, fname);
     }
   }
 
@@ -3077,7 +3077,7 @@ static void qf_list_entry(qfline_T *qfp, int qf_idx, bool cursel)
   }
 
   msg_putchar('\n');
-  msg_outtrans_attr((char *)IObuff, cursel ? HL_ATTR(HLF_QFL) : qfFileAttr);
+  msg_outtrans_attr(IObuff, cursel ? HL_ATTR(HLF_QFL) : qfFileAttr);
 
   if (qfp->qf_lnum != 0) {
     msg_puts_attr(":", qfSepAttr);
@@ -3085,13 +3085,13 @@ static void qf_list_entry(qfline_T *qfp, int qf_idx, bool cursel)
   if (qfp->qf_lnum == 0) {
     IObuff[0] = NUL;
   } else {
-    qf_range_text(qfp, (char *)IObuff, IOSIZE);
+    qf_range_text(qfp, IObuff, IOSIZE);
   }
-  vim_snprintf((char *)IObuff + strlen(IObuff), IOSIZE, "%s", qf_types(qfp->qf_type, qfp->qf_nr));
+  vim_snprintf(IObuff + strlen(IObuff), IOSIZE, "%s", qf_types(qfp->qf_type, qfp->qf_nr));
   msg_puts_attr((const char *)IObuff, qfLineAttr);
   msg_puts_attr(":", qfSepAttr);
   if (qfp->qf_pattern != NULL) {
-    qf_fmt_text(qfp->qf_pattern, (char *)IObuff, IOSIZE);
+    qf_fmt_text(qfp->qf_pattern, IObuff, IOSIZE);
     msg_puts((const char *)IObuff);
     msg_puts_attr(":", qfSepAttr);
   }
@@ -3975,14 +3975,14 @@ static int qf_buf_add_line(qf_list_T *qfl, buf_T *buf, linenr_T lnum, const qfli
       IObuff[len++] = '|';
     }
     if (qfp->qf_lnum > 0) {
-      qf_range_text(qfp, (char *)IObuff + len, IOSIZE - len);
+      qf_range_text(qfp, IObuff + len, IOSIZE - len);
       len += (int)strlen(IObuff + len);
 
-      snprintf((char *)IObuff + len, (size_t)(IOSIZE - len), "%s", qf_types(qfp->qf_type,
-                                                                            qfp->qf_nr));
+      snprintf(IObuff + len, (size_t)(IOSIZE - len), "%s", qf_types(qfp->qf_type,
+                                                                    qfp->qf_nr));
       len += (int)strlen(IObuff + len);
     } else if (qfp->qf_pattern != NULL) {
-      qf_fmt_text(qfp->qf_pattern, (char *)IObuff + len, IOSIZE - len);
+      qf_fmt_text(qfp->qf_pattern, IObuff + len, IOSIZE - len);
       len += (int)strlen(IObuff + len);
     }
     if (len < IOSIZE - 2) {
@@ -3994,7 +3994,7 @@ static int qf_buf_add_line(qf_list_T *qfl, buf_T *buf, linenr_T lnum, const qfli
     // For an unrecognized line keep the indent, the compiler may
     // mark a word with ^^^^.
     qf_fmt_text(len > 3 ? skipwhite(qfp->qf_text) : qfp->qf_text,
-                (char *)IObuff + len, IOSIZE - len);
+                IObuff + len, IOSIZE - len);
   }
 
   if (ml_append_buf(buf, lnum, (char_u *)IObuff,
@@ -6856,8 +6856,8 @@ void ex_cbuffer(exarg_T *eap)
   char *qf_title = qf_cmdtitle(*eap->cmdlinep);
 
   if (buf->b_sfname) {
-    vim_snprintf((char *)IObuff, IOSIZE, "%s (%s)", qf_title, buf->b_sfname);
-    qf_title = (char *)IObuff;
+    vim_snprintf(IObuff, IOSIZE, "%s (%s)", qf_title, buf->b_sfname);
+    qf_title = IObuff;
   }
 
   incr_quickfix_busy();
@@ -7002,7 +7002,7 @@ static void hgr_search_file(qf_list_T *qfl, char *fname, regmatch_T *p_regmatch)
 
   linenr_T lnum = 1;
   while (!vim_fgets(IObuff, IOSIZE, fd) && !got_int) {
-    char *line = (char *)IObuff;
+    char *line = IObuff;
 
     if (vim_regexec(p_regmatch, line, (colnr_T)0)) {
       int l = (int)strlen(line);
@@ -7085,9 +7085,9 @@ static void hgr_search_in_rtp(qf_list_T *qfl, regmatch_T *p_regmatch, const char
   // Go through all directories in 'runtimepath'
   char *p = p_rtp;
   while (*p != NUL && !got_int) {
-    copy_option_part(&p, (char *)NameBuff, MAXPATHL, ",");
+    copy_option_part(&p, NameBuff, MAXPATHL, ",");
 
-    hgr_search_files_in_dir(qfl, (char *)NameBuff, p_regmatch, (char *)lang);
+    hgr_search_files_in_dir(qfl, NameBuff, p_regmatch, (char *)lang);
   }
 }
 
diff --git a/src/nvim/runtime.c b/src/nvim/runtime.c
index 0e1fe67e4a..e009b883ca 100644
--- a/src/nvim/runtime.c
+++ b/src/nvim/runtime.c
@@ -2085,8 +2085,8 @@ int do_source(char *fname, int check_other, int is_vimrc)
   }
 
   if (l_time_fd != NULL) {
-    vim_snprintf((char *)IObuff, IOSIZE, "sourcing %s", fname);
-    time_msg((char *)IObuff, &start_time);
+    vim_snprintf(IObuff, IOSIZE, "sourcing %s", fname);
+    time_msg(IObuff, &start_time);
     time_pop(rel_time);
   }
 
@@ -2174,11 +2174,11 @@ void ex_scriptnames(exarg_T *eap)
 
   for (int i = 1; i <= script_items.ga_len && !got_int; i++) {
     if (SCRIPT_ITEM(i).sn_name != NULL) {
-      home_replace(NULL, SCRIPT_ITEM(i).sn_name, (char *)NameBuff, MAXPATHL, true);
-      vim_snprintf((char *)IObuff, IOSIZE, "%3d: %s", i, NameBuff);
-      if (!message_filtered((char *)IObuff)) {
+      home_replace(NULL, SCRIPT_ITEM(i).sn_name, NameBuff, MAXPATHL, true);
+      vim_snprintf(IObuff, IOSIZE, "%3d: %s", i, NameBuff);
+      if (!message_filtered(IObuff)) {
         msg_putchar('\n');
-        msg_outtrans((char *)IObuff);
+        msg_outtrans(IObuff);
         line_breakcheck();
       }
     }
@@ -2220,16 +2220,16 @@ char *get_scriptname(LastSet last_set, bool *should_free)
   case SID_LUA:
     return _("Lua");
   case SID_API_CLIENT:
-    snprintf((char *)IObuff, IOSIZE, _("API client (channel id %" PRIu64 ")"), last_set.channel_id);
-    return (char *)IObuff;
+    snprintf(IObuff, IOSIZE, _("API client (channel id %" PRIu64 ")"), last_set.channel_id);
+    return IObuff;
   case SID_STR:
     return _("anonymous :source");
   default: {
     char *const sname = SCRIPT_ITEM(last_set.script_ctx.sc_sid).sn_name;
     if (sname == NULL) {
-      snprintf((char *)IObuff, IOSIZE, _("anonymous :source (script id %d)"),
+      snprintf(IObuff, IOSIZE, _("anonymous :source (script id %d)"),
                last_set.script_ctx.sc_sid);
-      return (char *)IObuff;
+      return IObuff;
     }
 
     *should_free = true;
diff --git a/src/nvim/screen.c b/src/nvim/screen.c
index 58aec2e84c..52ab2ad25e 100644
--- a/src/nvim/screen.c
+++ b/src/nvim/screen.c
@@ -547,8 +547,8 @@ int showmode(void)
           if (curwin->w_p_arab) {
             msg_puts_attr(_(" Arabic"), attr);
           } else if (get_keymap_str(curwin, " (%s)",
-                                    (char *)NameBuff, MAXPATHL)) {
-            msg_puts_attr((char *)NameBuff, attr);
+                                    NameBuff, MAXPATHL)) {
+            msg_puts_attr(NameBuff, attr);
           }
         }
         if ((State & MODE_INSERT) && p_paste) {
@@ -683,9 +683,9 @@ void get_trans_bufname(buf_T *buf)
   if (buf_spname(buf) != NULL) {
     xstrlcpy(NameBuff, buf_spname(buf), MAXPATHL);
   } else {
-    home_replace(buf, buf->b_fname, (char *)NameBuff, MAXPATHL, true);
+    home_replace(buf, buf->b_fname, NameBuff, MAXPATHL, true);
   }
-  trans_characters((char *)NameBuff, MAXPATHL);
+  trans_characters(NameBuff, MAXPATHL);
 }
 
 /// Get the character to use in a separator between vertically split windows.
diff --git a/src/nvim/search.c b/src/nvim/search.c
index 51ad2b0cbb..73a62429bd 100644
--- a/src/nvim/search.c
+++ b/src/nvim/search.c
@@ -3678,10 +3678,10 @@ void find_pattern_in_path(char *ptr, Direction dir, size_t len, bool whole, bool
           files[depth].matched = false;
           if (action == ACTION_EXPAND) {
             msg_hist_off = true;                // reset in msg_trunc_attr()
-            vim_snprintf((char *)IObuff, IOSIZE,
+            vim_snprintf(IObuff, IOSIZE,
                          _("Scanning included file: %s"),
                          (char *)new_fname);
-            msg_trunc_attr((char *)IObuff, true, HL_ATTR(HLF_R));
+            msg_trunc_attr(IObuff, true, HL_ATTR(HLF_R));
           } else if (p_verbose >= 5) {
             verbose_enter();
             smsg(_("Searching included file %s"),
@@ -3775,7 +3775,7 @@ search_line:
         char *aux = p = startp;
         if (compl_status_adding()) {
           p += ins_compl_len();
-          if (vim_iswordp((char_u *)p)) {
+          if (vim_iswordp(p)) {
             goto exit_matched;
           }
           p = (char *)find_word_start((char_u *)p);
@@ -4056,9 +4056,9 @@ static void show_pat_in_path(char *line, int type, bool did_show, int action, FI
       *(p + 1) = NUL;
     }
     if (action == ACTION_SHOW_ALL) {
-      snprintf((char *)IObuff, IOSIZE, "%3ld: ", count);  // Show match nr.
+      snprintf(IObuff, IOSIZE, "%3ld: ", count);  // Show match nr.
       msg_puts((const char *)IObuff);
-      snprintf((char *)IObuff, IOSIZE, "%4" PRIdLINENR, *lnum);  // Show line nr.
+      snprintf(IObuff, IOSIZE, "%4" PRIdLINENR, *lnum);  // Show line nr.
       // Highlight line numbers.
       msg_puts_attr((const char *)IObuff, HL_ATTR(HLF_N));
       msg_puts(" ");
diff --git a/src/nvim/shada.c b/src/nvim/shada.c
index 151cb834be..8c17d8d8be 100644
--- a/src/nvim/shada.c
+++ b/src/nvim/shada.c
@@ -4017,7 +4017,7 @@ static bool shada_removable(const char *name)
   for (p = p_shada; *p;) {
     (void)copy_option_part(&p, part, ARRAY_SIZE(part), ", ");
     if (part[0] == 'r') {
-      home_replace(NULL, part + 1, (char *)NameBuff, MAXPATHL, true);
+      home_replace(NULL, part + 1, NameBuff, MAXPATHL, true);
       size_t n = strlen(NameBuff);
       if (mb_strnicmp(NameBuff, new_name, n) == 0) {
         retval = true;
diff --git a/src/nvim/spell.c b/src/nvim/spell.c
index 33dd76b704..10abd16ca7 100644
--- a/src/nvim/spell.c
+++ b/src/nvim/spell.c
@@ -3231,8 +3231,8 @@ void spell_dump_compl(char *pat, int ic, Direction *dir, int dumpflags_arg)
 
   if (do_region && region_names != NULL) {
     if (pat == NULL) {
-      vim_snprintf((char *)IObuff, IOSIZE, "/regions=%s", region_names);
-      ml_append(lnum++, (char *)IObuff, (colnr_T)0, false);
+      vim_snprintf(IObuff, IOSIZE, "/regions=%s", region_names);
+      ml_append(lnum++, IObuff, (colnr_T)0, false);
     }
   } else {
     do_region = false;
@@ -3247,8 +3247,8 @@ void spell_dump_compl(char *pat, int ic, Direction *dir, int dumpflags_arg)
     }
 
     if (pat == NULL) {
-      vim_snprintf((char *)IObuff, IOSIZE, "# file: %s", slang->sl_fname);
-      ml_append(lnum++, (char *)IObuff, (colnr_T)0, false);
+      vim_snprintf(IObuff, IOSIZE, "# file: %s", slang->sl_fname);
+      ml_append(lnum++, IObuff, (colnr_T)0, false);
     }
 
     // When matching with a pattern and there are no prefixes only use
@@ -3411,7 +3411,7 @@ static void dump_word(slang_T *slang, char *word, char *pat, Direction *dir, int
       // Include the word count for ":spelldump!".
       hi = hash_find(&slang->sl_wordcount, tw);
       if (!HASHITEM_EMPTY(hi)) {
-        vim_snprintf((char *)IObuff, IOSIZE, "%s\t%d",
+        vim_snprintf(IObuff, IOSIZE, "%s\t%d",
                      tw, HI2WC(hi)->wc_count);
         p = IObuff;
       }
diff --git a/src/nvim/spellfile.c b/src/nvim/spellfile.c
index d01acd6300..5b99d0767c 100644
--- a/src/nvim/spellfile.c
+++ b/src/nvim/spellfile.c
@@ -2064,8 +2064,8 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
     return NULL;
   }
 
-  vim_snprintf((char *)IObuff, IOSIZE, _("Reading affix file %s..."), fname);
-  spell_message(spin, (char *)IObuff);
+  vim_snprintf(IObuff, IOSIZE, _("Reading affix file %s..."), fname);
+  spell_message(spin, IObuff);
 
   // Only do REP lines when not done in another .aff file already.
   do_rep = GA_EMPTY(&spin->si_rep);
@@ -3137,9 +3137,9 @@ static int spell_read_dic(spellinfo_T *spin, char_u *fname, afffile_T *affile)
   // The hashtable is only used to detect duplicated words.
   hash_init(&ht);
 
-  vim_snprintf((char *)IObuff, IOSIZE,
+  vim_snprintf(IObuff, IOSIZE,
                _("Reading dictionary file %s..."), fname);
-  spell_message(spin, (char *)IObuff);
+  spell_message(spin, IObuff);
 
   // start with a message for the first line
   spin->si_msg_count = 999999;
@@ -3691,8 +3691,8 @@ static int spell_read_wordfile(spellinfo_T *spin, char_u *fname)
     return FAIL;
   }
 
-  vim_snprintf((char *)IObuff, IOSIZE, _("Reading word file %s..."), fname);
-  spell_message(spin, (char *)IObuff);
+  vim_snprintf(IObuff, IOSIZE, _("Reading word file %s..."), fname);
+  spell_message(spin, IObuff);
 
   // Read all the lines in the file one by one.
   while (!vim_fgets((char *)rline, MAXLINELEN, fd) && !got_int) {
@@ -3834,9 +3834,9 @@ static int spell_read_wordfile(spellinfo_T *spin, char_u *fname)
   fclose(fd);
 
   if (spin->si_ascii && non_ascii > 0) {
-    vim_snprintf((char *)IObuff, IOSIZE,
+    vim_snprintf(IObuff, IOSIZE,
                  _("Ignored %d words with non-ASCII characters"), non_ascii);
-    spell_message(spin, (char *)IObuff);
+    spell_message(spin, IObuff);
   }
 
   return retval;
@@ -4226,10 +4226,10 @@ static void wordtree_compress(spellinfo_T *spin, wordnode_T *root, const char *n
       } else {
         perc = (tot - n) * 100 / tot;
       }
-      vim_snprintf((char *)IObuff, IOSIZE,
+      vim_snprintf(IObuff, IOSIZE,
                    _("Compressed %s of %ld nodes; %ld (%ld%%) remaining"),
                    name, tot, tot - n, perc);
-      spell_message(spin, (char *)IObuff);
+      spell_message(spin, IObuff);
     }
 #ifdef SPELL_PRINTTREE
     spell_print_tree(root->wn_sibling);
@@ -5208,9 +5208,9 @@ static void sug_write(spellinfo_T *spin, char_u *fname)
     return;
   }
 
-  vim_snprintf((char *)IObuff, IOSIZE,
+  vim_snprintf(IObuff, IOSIZE,
                _("Writing suggestion file %s..."), fname);
-  spell_message(spin, (char *)IObuff);
+  spell_message(spin, IObuff);
 
   // <SUGHEADER>: <fileID> <versionnr> <timestamp>
   if (fwrite(VIMSUGMAGIC, VIMSUGMAGICL, (size_t)1, fd) != 1) {  // <fileID>
@@ -5264,9 +5264,9 @@ static void sug_write(spellinfo_T *spin, char_u *fname)
     emsg(_(e_write));
   }
 
-  vim_snprintf((char *)IObuff, IOSIZE,
+  vim_snprintf(IObuff, IOSIZE,
                _("Estimated runtime memory use: %d bytes"), spin->si_memtot);
-  spell_message(spin, (char *)IObuff);
+  spell_message(spin, IObuff);
 
 theend:
   // close the file
@@ -5445,16 +5445,16 @@ static void mkspell(int fcount, char **fnames, bool ascii, bool over_write, bool
 
     if (!error && !got_int) {
       // Write the info in the spell file.
-      vim_snprintf((char *)IObuff, IOSIZE,
+      vim_snprintf(IObuff, IOSIZE,
                    _("Writing spell file %s..."), wfname);
-      spell_message(&spin, (char *)IObuff);
+      spell_message(&spin, IObuff);
 
       error = write_vim_spell(&spin, wfname) == FAIL;
 
       spell_message(&spin, _("Done!"));
-      vim_snprintf((char *)IObuff, IOSIZE,
+      vim_snprintf(IObuff, IOSIZE,
                    _("Estimated runtime memory use: %d bytes"), spin.si_memtot);
-      spell_message(&spin, (char *)IObuff);
+      spell_message(&spin, IObuff);
 
       // If the file is loaded need to reload it.
       if (!error) {
@@ -5616,7 +5616,7 @@ void spell_add_word(char *word, int len, SpellAddType what, int idx, bool undo)
           if (fseek(fd, fpos, SEEK_SET) == 0) {
             fputc('#', fd);
             if (undo) {
-              home_replace(NULL, fname, (char *)NameBuff, MAXPATHL, true);
+              home_replace(NULL, fname, NameBuff, MAXPATHL, true);
               smsg(_("Word '%.*s' removed from %s"), len, word, NameBuff);
             }
           }
@@ -5666,7 +5666,7 @@ void spell_add_word(char *word, int len, SpellAddType what, int idx, bool undo)
       }
       fclose(fd);
 
-      home_replace(NULL, fname, (char *)NameBuff, MAXPATHL, true);
+      home_replace(NULL, fname, NameBuff, MAXPATHL, true);
       smsg(_("Word '%.*s' added to %s"), len, word, NameBuff);
     }
   }
diff --git a/src/nvim/spellsuggest.c b/src/nvim/spellsuggest.c
index bde61e753c..2768a89d6c 100644
--- a/src/nvim/spellsuggest.c
+++ b/src/nvim/spellsuggest.c
@@ -544,12 +544,12 @@ void spell_suggest(int count)
     msg_start();
     msg_row = Rows - 1;         // for when 'cmdheight' > 1
     lines_left = Rows;          // avoid more prompt
-    vim_snprintf((char *)IObuff, IOSIZE, _("Change \"%.*s\" to:"),
+    vim_snprintf(IObuff, IOSIZE, _("Change \"%.*s\" to:"),
                  sug.su_badlen, sug.su_badptr);
     if (cmdmsg_rl && strncmp(IObuff, "Change", 6) == 0) {
       // And now the rabbit from the high hat: Avoid showing the
       // untranslated message rightleft.
-      vim_snprintf((char *)IObuff, IOSIZE, ":ot \"%.*s\" egnahC",
+      vim_snprintf(IObuff, IOSIZE, ":ot \"%.*s\" egnahC",
                    sug.su_badlen, sug.su_badptr);
     }
     msg_puts((const char *)IObuff);
@@ -567,18 +567,18 @@ void spell_suggest(int count)
       if (el > 0 && stp->st_wordlen + el <= MAXWLEN) {
         xstrlcpy(wcopy + stp->st_wordlen, sug.su_badptr + stp->st_orglen, (size_t)el + 1);
       }
-      vim_snprintf((char *)IObuff, IOSIZE, "%2d", i + 1);
+      vim_snprintf(IObuff, IOSIZE, "%2d", i + 1);
       if (cmdmsg_rl) {
         rl_mirror(IObuff);
       }
       msg_puts((const char *)IObuff);
 
-      vim_snprintf((char *)IObuff, IOSIZE, " \"%s\"", wcopy);
+      vim_snprintf(IObuff, IOSIZE, " \"%s\"", wcopy);
       msg_puts((const char *)IObuff);
 
       // The word may replace more than "su_badlen".
       if (sug.su_badlen < stp->st_orglen) {
-        vim_snprintf((char *)IObuff, IOSIZE, _(" < \"%.*s\""),
+        vim_snprintf(IObuff, IOSIZE, _(" < \"%.*s\""),
                      stp->st_orglen, sug.su_badptr);
         msg_puts((const char *)IObuff);
       }
@@ -586,11 +586,11 @@ void spell_suggest(int count)
       if (p_verbose > 0) {
         // Add the score.
         if (sps_flags & (SPS_DOUBLE | SPS_BEST)) {
-          vim_snprintf((char *)IObuff, IOSIZE, " (%s%d - %d)",
+          vim_snprintf(IObuff, IOSIZE, " (%s%d - %d)",
                        stp->st_salscore ? "s " : "",
                        stp->st_score, stp->st_altscore);
         } else {
-          vim_snprintf((char *)IObuff, IOSIZE, " (%d)",
+          vim_snprintf(IObuff, IOSIZE, " (%d)",
                        stp->st_score);
         }
         if (cmdmsg_rl) {
@@ -630,10 +630,10 @@ void spell_suggest(int count)
       // Replacing less than "su_badlen", append the remainder to
       // repl_to.
       repl_from = xstrnsave(sug.su_badptr, (size_t)sug.su_badlen);
-      vim_snprintf((char *)IObuff, IOSIZE, "%s%.*s", stp->st_word,
+      vim_snprintf(IObuff, IOSIZE, "%s%.*s", stp->st_word,
                    sug.su_badlen - stp->st_orglen,
                    sug.su_badptr + stp->st_orglen);
-      repl_to = xstrdup((char *)IObuff);
+      repl_to = xstrdup(IObuff);
     } else {
       // Replacing su_badlen or more, use the whole word.
       repl_from = xstrnsave(sug.su_badptr, (size_t)stp->st_orglen);
diff --git a/src/nvim/statusline.c b/src/nvim/statusline.c
index 80936251b0..0f28eae0d8 100644
--- a/src/nvim/statusline.c
+++ b/src/nvim/statusline.c
@@ -155,7 +155,7 @@ void win_redr_status(win_T *wp)
     grid_fill(&default_grid, row, row + 1, len + col,
               this_ru_col + col, fillchar, fillchar, attr);
 
-    if (get_keymap_str(wp, "<%s>", (char *)NameBuff, MAXPATHL)
+    if (get_keymap_str(wp, "<%s>", NameBuff, MAXPATHL)
         && this_ru_col - len > (int)(strlen(NameBuff) + 1)) {
       grid_puts(&default_grid, NameBuff, row,
                 (int)((size_t)this_ru_col - strlen(NameBuff) - 1), attr);
@@ -666,7 +666,7 @@ static void ui_ext_tabline_update(void)
 
     win_T *cwp = (tp == curtab) ? curwin : tp->tp_curwin;
     get_trans_bufname(cwp->w_buffer);
-    PUT_C(tab_info, "name", STRING_OBJ(arena_string(&arena, cstr_as_string((char *)NameBuff))));
+    PUT_C(tab_info, "name", STRING_OBJ(arena_string(&arena, cstr_as_string(NameBuff))));
 
     ADD_C(tabs, DICTIONARY_OBJ(tab_info));
   }
@@ -687,7 +687,7 @@ static void ui_ext_tabline_update(void)
     PUT_C(buffer_info, "buffer", BUFFER_OBJ(buf->handle));
 
     get_trans_bufname(buf);
-    PUT_C(buffer_info, "name", STRING_OBJ(arena_string(&arena, cstr_as_string((char *)NameBuff))));
+    PUT_C(buffer_info, "name", STRING_OBJ(arena_string(&arena, cstr_as_string(NameBuff))));
 
     ADD_C(buffers, DICTIONARY_OBJ(buffer_info));
   }
@@ -787,7 +787,7 @@ void draw_tabline(void)
 
       if (modified || wincount > 1) {
         if (wincount > 1) {
-          vim_snprintf((char *)NameBuff, MAXPATHL, "%d", wincount);
+          vim_snprintf(NameBuff, MAXPATHL, "%d", wincount);
           len = (int)strlen(NameBuff);
           if (col + len >= Columns - 3) {
             break;
@@ -807,7 +807,7 @@ void draw_tabline(void)
         // Get buffer name in NameBuff[]
         get_trans_bufname(cwp->w_buffer);
         shorten_dir(NameBuff);
-        len = vim_strsize((char *)NameBuff);
+        len = vim_strsize(NameBuff);
         p = (char_u *)NameBuff;
         while (len > room) {
           len -= ptr2cells((char *)p);
@@ -1353,13 +1353,13 @@ int build_stl_str_hl(win_T *wp, char *out, size_t outlen, char *fmt, char *opt_n
       } else {
         char *t = (opt == STL_FULLPATH) ? wp->w_buffer->b_ffname
                                           : wp->w_buffer->b_fname;
-        home_replace(wp->w_buffer, t, (char *)NameBuff, MAXPATHL, true);
+        home_replace(wp->w_buffer, t, NameBuff, MAXPATHL, true);
       }
-      trans_characters((char *)NameBuff, MAXPATHL);
+      trans_characters(NameBuff, MAXPATHL);
       if (opt != STL_FILENAME) {
-        str = (char *)NameBuff;
+        str = NameBuff;
       } else {
-        str = path_tail((char *)NameBuff);
+        str = path_tail(NameBuff);
       }
       break;
     case STL_VIM_EXPR:     // '{'
diff --git a/src/nvim/syntax.c b/src/nvim/syntax.c
index 8f0d8d2041..87d537559a 100644
--- a/src/nvim/syntax.c
+++ b/src/nvim/syntax.c
@@ -2754,7 +2754,7 @@ static int check_keyword_id(char *const line, const int startcol, int *const end
 
   // ignoring case
   if (kp == NULL && syn_block->b_keywtab_ic.ht_used != 0) {
-    str_foldcase((char_u *)kwp, kwlen, keyword, MAXKEYWLEN + 1);
+    str_foldcase(kwp, kwlen, keyword, MAXKEYWLEN + 1);
     kp = match_keyword(keyword, &syn_block->b_keywtab_ic, cur_si);
   }
 
@@ -3727,8 +3727,8 @@ static void add_keyword(char *const name, const int id, const int flags,
 {
   char name_folded[MAXKEYWLEN + 1];
   const char *const name_ic = (curwin->w_s->b_syn_ic)
-      ? (char *)str_foldcase((char_u *)name, (int)strlen(name), name_folded,
-                             sizeof(name_folded))
+      ? str_foldcase(name, (int)strlen(name), name_folded,
+                     sizeof(name_folded))
       : name;
 
   keyentry_T *const kp = xmalloc(sizeof(keyentry_T) + strlen(name_ic));
diff --git a/src/nvim/tag.c b/src/nvim/tag.c
index 72d7ae1154..42de9e1152 100644
--- a/src/nvim/tag.c
+++ b/src/nvim/tag.c
@@ -720,7 +720,7 @@ void do_tag(char *tag, int type, int count, int forceit, int verbose)
           && (num_matches > 1 || ic)
           && !skip_msg) {
         // Give an indication of the number of matching tags
-        snprintf((char *)IObuff, sizeof(IObuff), _("tag %d of %d%s"),
+        snprintf(IObuff, sizeof(IObuff), _("tag %d of %d%s"),
                  cur_match + 1,
                  num_matches,
                  max_num_matches != MAXCOL ? _(" or more") : "");
@@ -732,11 +732,11 @@ void do_tag(char *tag, int type, int count, int forceit, int verbose)
           if (ic) {
             msg_attr((const char *)IObuff, HL_ATTR(HLF_W));
           } else {
-            msg((char *)IObuff);
+            msg(IObuff);
           }
           msg_scroll = true;  // Don't overwrite this message.
         } else {
-          give_warning((char *)IObuff, ic);
+          give_warning(IObuff, ic);
         }
         if (ic && !msg_scrolled && msg_silent == 0) {
           ui_flush();
@@ -745,8 +745,8 @@ void do_tag(char *tag, int type, int count, int forceit, int verbose)
       }
 
       // Let the SwapExists event know what tag we are jumping to.
-      vim_snprintf((char *)IObuff, IOSIZE, ":ta %s\r", name);
-      set_vim_var_string(VV_SWAPCOMMAND, (char *)IObuff, -1);
+      vim_snprintf(IObuff, IOSIZE, ":ta %s\r", name);
+      set_vim_var_string(VV_SWAPCOMMAND, IObuff, -1);
 
       // Jump to the desired match.
       i = jumpto_tag((char_u *)matches[cur_match], forceit, true);
@@ -836,10 +836,10 @@ static void print_tag_list(int new_tag, int use_tagstack, int num_matches, char
     } else {
       *IObuff = ' ';
     }
-    vim_snprintf((char *)IObuff + 1, IOSIZE - 1,
+    vim_snprintf(IObuff + 1, IOSIZE - 1,
                  "%2d %s ", i + 1,
                  mt_names[matches[i][0] & MT_MASK]);
-    msg_puts((char *)IObuff);
+    msg_puts(IObuff);
     if (tagp.tagkind != NULL) {
       msg_outtrans_len((char *)tagp.tagkind,
                        (int)(tagp.tagkind_end - tagp.tagkind));
@@ -1099,8 +1099,8 @@ static int add_llist_tags(char_u *tag, int num_matches, char **matches)
     }
   }
 
-  vim_snprintf((char *)IObuff, IOSIZE, "ltag %s", tag);
-  set_errorlist(curwin, list, ' ', (char *)IObuff, NULL);
+  vim_snprintf(IObuff, IOSIZE, "ltag %s", tag);
+  set_errorlist(curwin, list, ' ', IObuff, NULL);
 
   tv_list_free(list);
   XFREE_CLEAR(fname);
@@ -1144,13 +1144,13 @@ void do_tags(exarg_T *eap)
       }
 
       msg_putchar('\n');
-      vim_snprintf((char *)IObuff, IOSIZE, "%c%2d %2d %-15s %5" PRIdLINENR "  ",
+      vim_snprintf(IObuff, IOSIZE, "%c%2d %2d %-15s %5" PRIdLINENR "  ",
                    i == tagstackidx ? '>' : ' ',
                    i + 1,
                    tagstack[i].cur_match + 1,
                    tagstack[i].tagname,
                    tagstack[i].fmark.mark.lnum);
-      msg_outtrans((char *)IObuff);
+      msg_outtrans(IObuff);
       msg_outtrans_attr((char *)name, tagstack[i].fmark.fnum == curbuf->b_fnum
                         ? HL_ATTR(HLF_D) : 0);
       xfree(name);
@@ -3227,7 +3227,7 @@ static void tagstack_clear_entry(taggy_T *item)
 }
 
 /// @param tagnames  expand tag names
-int expand_tags(int tagnames, char_u *pat, int *num_file, char ***file)
+int expand_tags(int tagnames, char *pat, int *num_file, char ***file)
 {
   int i;
   int extra_flag;
@@ -3244,11 +3244,11 @@ int expand_tags(int tagnames, char_u *pat, int *num_file, char ***file)
     extra_flag = 0;
   }
   if (pat[0] == '/') {
-    ret = find_tags((char *)pat + 1, num_file, file,
+    ret = find_tags(pat + 1, num_file, file,
                     TAG_REGEXP | extra_flag | TAG_VERBOSE | TAG_NO_TAGFUNC,
                     TAG_MANY, curbuf->b_ffname);
   } else {
-    ret = find_tags((char *)pat, num_file, file,
+    ret = find_tags(pat, num_file, file,
                     TAG_REGEXP | extra_flag | TAG_VERBOSE | TAG_NO_TAGFUNC | TAG_NOIC,
                     TAG_MANY, curbuf->b_ffname);
   }
@@ -3324,17 +3324,17 @@ static int add_tag_field(dict_T *dict, const char *field_name, const char *start
 
 /// Add the tags matching the specified pattern "pat" to the list "list"
 /// as a dictionary. Use "buf_fname" for priority, unless NULL.
-int get_tags(list_T *list, char_u *pat, char_u *buf_fname)
+int get_tags(list_T *list, char *pat, char *buf_fname)
 {
   int num_matches, i, ret;
   char **matches;
-  char_u *full_fname;
+  char *full_fname;
   dict_T *dict;
   tagptrs_T tp;
   bool is_static;
 
-  ret = find_tags((char *)pat, &num_matches, &matches,
-                  TAG_REGEXP | TAG_NOIC, MAXCOL, (char *)buf_fname);
+  ret = find_tags(pat, &num_matches, &matches,
+                  TAG_REGEXP | TAG_NOIC, MAXCOL, buf_fname);
   if (ret == OK && num_matches > 0) {
     for (i = 0; i < num_matches; i++) {
       int parse_result = parse_match(matches[i], &tp);
@@ -3354,9 +3354,9 @@ int get_tags(list_T *list, char_u *pat, char_u *buf_fname)
       dict = tv_dict_alloc();
       tv_list_append_dict(list, dict);
 
-      full_fname = tag_full_fname(&tp);
+      full_fname = (char *)tag_full_fname(&tp);
       if (add_tag_field(dict, "name", tp.tagname, (char *)tp.tagname_end) == FAIL
-          || add_tag_field(dict, "filename", (char *)full_fname, NULL) == FAIL
+          || add_tag_field(dict, "filename", full_fname, NULL) == FAIL
           || add_tag_field(dict, "cmd", tp.command, (char *)tp.command_end) == FAIL
           || add_tag_field(dict, "kind", (char *)tp.tagkind,
                            tp.tagkind ? (char *)tp.tagkind_end : NULL) == FAIL
diff --git a/src/nvim/testing.c b/src/nvim/testing.c
index 8c54d9ad32..edb24c6dc5 100644
--- a/src/nvim/testing.c
+++ b/src/nvim/testing.c
@@ -394,12 +394,12 @@ static int assert_equalfile(typval_T *argvars)
   char line2[200];
   ptrdiff_t lineidx = 0;
   if (fd1 == NULL) {
-    snprintf((char *)IObuff, IOSIZE, (char *)e_notread, fname1);
+    snprintf(IObuff, IOSIZE, (char *)e_notread, fname1);
   } else {
     FILE *const fd2 = os_fopen(fname2, READBIN);
     if (fd2 == NULL) {
       fclose(fd1);
-      snprintf((char *)IObuff, IOSIZE, (char *)e_notread, fname2);
+      snprintf(IObuff, IOSIZE, (char *)e_notread, fname2);
     } else {
       int64_t linecount = 1;
       for (int64_t count = 0;; count++) {
@@ -418,7 +418,7 @@ static int assert_equalfile(typval_T *argvars)
           line2[lineidx] = (char)c2;
           lineidx++;
           if (c1 != c2) {
-            snprintf((char *)IObuff, IOSIZE,
+            snprintf(IObuff, IOSIZE,
                      "difference at byte %" PRId64 ", line %" PRId64,
                      count, linecount);
             break;
@@ -445,7 +445,7 @@ static int assert_equalfile(typval_T *argvars)
       xfree(tofree);
       ga_concat(&ga, ": ");
     }
-    ga_concat(&ga, (char *)IObuff);
+    ga_concat(&ga, IObuff);
     if (lineidx > 0) {
       line1[lineidx] = NUL;
       line2[lineidx] = NUL;
diff --git a/src/nvim/undo.c b/src/nvim/undo.c
index 9cbe5d5d9e..c39e11f266 100644
--- a/src/nvim/undo.c
+++ b/src/nvim/undo.c
@@ -2569,7 +2569,7 @@ static void u_undo_end(bool did_undo, bool absolute, bool quiet)
   if (uhp == NULL) {
     *msgbuf = NUL;
   } else {
-    undo_fmt_time(msgbuf, sizeof(msgbuf), uhp->uh_time);
+    undo_fmt_time((char *)msgbuf, sizeof(msgbuf), uhp->uh_time);
   }
 
   {
@@ -2594,7 +2594,7 @@ static void u_undo_end(bool did_undo, bool absolute, bool quiet)
 }
 
 /// Put the timestamp of an undo header in "buf[buflen]" in a nice format.
-void undo_fmt_time(char_u *buf, size_t buflen, time_t tt)
+void undo_fmt_time(char *buf, size_t buflen, time_t tt)
 {
   if (time(NULL) - tt >= 100) {
     struct tm curtime;
@@ -2602,17 +2602,17 @@ void undo_fmt_time(char_u *buf, size_t buflen, time_t tt)
     size_t n;
     if (time(NULL) - tt < (60L * 60L * 12L)) {
       // within 12 hours
-      n = strftime((char *)buf, buflen, "%H:%M:%S", &curtime);
+      n = strftime(buf, buflen, "%H:%M:%S", &curtime);
     } else {
       // longer ago
-      n = strftime((char *)buf, buflen, "%Y/%m/%d %H:%M:%S", &curtime);
+      n = strftime(buf, buflen, "%Y/%m/%d %H:%M:%S", &curtime);
     }
     if (n == 0) {
       buf[0] = NUL;
     }
   } else {
     int64_t seconds = time(NULL) - tt;
-    vim_snprintf((char *)buf, buflen,
+    vim_snprintf(buf, buflen,
                  NGETTEXT("%" PRId64 " second ago",
                           "%" PRId64 " seconds ago", (uint32_t)seconds),
                  seconds);
@@ -2654,15 +2654,15 @@ void ex_undolist(exarg_T *eap)
   while (uhp != NULL) {
     if (uhp->uh_prev.ptr == NULL && uhp->uh_walk != nomark
         && uhp->uh_walk != mark) {
-      vim_snprintf((char *)IObuff, IOSIZE, "%6ld %7d  ", uhp->uh_seq, changes);
-      undo_fmt_time((char_u *)IObuff + strlen(IObuff), IOSIZE - strlen(IObuff), uhp->uh_time);
+      vim_snprintf(IObuff, IOSIZE, "%6ld %7d  ", uhp->uh_seq, changes);
+      undo_fmt_time(IObuff + strlen(IObuff), IOSIZE - strlen(IObuff), uhp->uh_time);
       if (uhp->uh_save_nr > 0) {
         while (strlen(IObuff) < 33) {
           STRCAT(IObuff, " ");
         }
-        vim_snprintf_add((char *)IObuff, IOSIZE, "  %3ld", uhp->uh_save_nr);
+        vim_snprintf_add(IObuff, IOSIZE, "  %3ld", uhp->uh_save_nr);
       }
-      GA_APPEND(char *, &ga, xstrdup((char *)IObuff));
+      GA_APPEND(char *, &ga, xstrdup(IObuff));
     }
 
     uhp->uh_walk = mark;
diff --git a/src/nvim/usercmd.c b/src/nvim/usercmd.c
index bc47b1b807..0109c048ec 100644
--- a/src/nvim/usercmd.c
+++ b/src/nvim/usercmd.c
@@ -484,14 +484,14 @@ static void uc_list(char *name, size_t name_len)
       if (a & (EX_RANGE | EX_COUNT)) {
         if (a & EX_COUNT) {
           // -count=N
-          snprintf((char *)IObuff + len, IOSIZE, "%" PRId64 "c",
+          snprintf(IObuff + len, IOSIZE, "%" PRId64 "c",
                    (int64_t)cmd->uc_def);
           len += (int)strlen(IObuff + len);
         } else if (a & EX_DFLALL) {
           IObuff[len++] = '%';
         } else if (cmd->uc_def >= 0) {
           // -range=N
-          snprintf((char *)IObuff + len, IOSIZE, "%" PRId64 "",
+          snprintf(IObuff + len, IOSIZE, "%" PRId64 "",
                    (int64_t)cmd->uc_def);
           len += (int)strlen(IObuff + len);
         } else {
@@ -529,7 +529,7 @@ static void uc_list(char *name, size_t name_len)
       } while (len < 25 - over);
 
       IObuff[len] = '\0';
-      msg_outtrans((char *)IObuff);
+      msg_outtrans(IObuff);
 
       if (cmd->uc_luaref != LUA_NOREF) {
         char *fn = nlua_funcref_str(cmd->uc_luaref);