Merge pull request #18425 from dundargoc/refactor/char_u/1

refactor: replace char_u variables and functions with char

51 files changed, 508 insertions, 506 deletions

diff --git a/src/nvim/api/extmark.c b/src/nvim/api/extmark.c
index 1f47ac4ebb..e05d80812d 100644
--- a/src/nvim/api/extmark.c
+++ b/src/nvim/api/extmark.c
@@ -586,7 +586,7 @@ Integer nvim_buf_set_extmark(Buffer buffer, Integer ns_id, Integer line, Integer
     String c = opts->conceal.data.string;
     decor.conceal = true;
     if (c.size) {
-      decor.conceal_char = utf_ptr2char((const char_u *)c.data);
+      decor.conceal_char = utf_ptr2char(c.data);
     }
     has_decor = true;
   } else if (HAS_KEY(opts->conceal)) {
diff --git a/src/nvim/api/private/helpers.c b/src/nvim/api/private/helpers.c
index 9f894d5533..a2ee4f91bc 100644
--- a/src/nvim/api/private/helpers.c
+++ b/src/nvim/api/private/helpers.c
@@ -654,9 +654,9 @@ void modify_keymap(uint64_t channel_id, Buffer buffer, bool is_unmap, String mod
   int mode_val;  // integer value of the mapping mode, to be passed to do_map()
   char *p = (mode.size) ? mode.data : "m";
   if (STRNCMP(p, "!", 2) == 0) {
-    mode_val = get_map_mode((char_u **)&p, true);  // mapmode-ic
+    mode_val = get_map_mode(&p, true);  // mapmode-ic
   } else {
-    mode_val = get_map_mode((char_u **)&p, false);
+    mode_val = get_map_mode(&p, false);
     if ((mode_val == VISUAL + SELECTMODE + NORMAL + OP_PENDING)
         && mode.size > 0) {
       // get_map_mode() treats unrecognized mode shortnames as ":map".
@@ -1128,7 +1128,7 @@ ArrayOf(Dictionary) keymap_array(String mode, buf_T *buf, bool from_lua)
 
   // Convert the string mode to the integer mode
   // that is stored within each mapblock
-  char_u *p = (char_u *)mode.data;
+  char *p = mode.data;
   int int_mode = get_map_mode(&p, 0);
 
   // Determine the desired buffer value
@@ -1666,11 +1666,11 @@ int init_sign_text(char **sign_text, char *text)
 
   // Count cells and check for non-printable chars
   int cells = 0;
-  for (s = text; s < endp; s += utfc_ptr2len((char_u *)s)) {
-    if (!vim_isprintc(utf_ptr2char((char_u *)s))) {
+  for (s = text; s < endp; s += utfc_ptr2len(s)) {
+    if (!vim_isprintc(utf_ptr2char(s))) {
       break;
     }
-    cells += utf_ptr2cells((char_u *)s);
+    cells += utf_ptr2cells(s);
   }
   // Currently must be empty, one or two display cells
   if (s != endp || cells > 2) {
diff --git a/src/nvim/api/ui.c b/src/nvim/api/ui.c
index d1b86ed328..b4d20ed975 100644
--- a/src/nvim/api/ui.c
+++ b/src/nvim/api/ui.c
@@ -665,7 +665,7 @@ static void remote_ui_raw_line(UI *ui, Integer grid, Integer row, Integer startc
       remote_ui_cursor_goto(ui, row, startcol + i);
       remote_ui_highlight_set(ui, attrs[i]);
       remote_ui_put(ui, (const char *)chunk[i]);
-      if (utf_ambiguous_width(utf_ptr2char(chunk[i]))) {
+      if (utf_ambiguous_width(utf_ptr2char((char *)chunk[i]))) {
         data->client_col = -1;  // force cursor update
       }
     }
diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
index 7f4fafa71b..185c043b06 100644
--- a/src/nvim/api/vim.c
+++ b/src/nvim/api/vim.c
@@ -2287,12 +2287,12 @@ Dictionary nvim_eval_statusline(String str, Dict(eval_statusline) *opts, Error *
 
   if (HAS_KEY(opts->fillchar)) {
     if (opts->fillchar.type != kObjectTypeString || opts->fillchar.data.string.size == 0
-        || ((size_t)utf_ptr2len((char_u *)opts->fillchar.data.string.data)
+        || ((size_t)utf_ptr2len(opts->fillchar.data.string.data)
             != opts->fillchar.data.string.size)) {
       api_set_error(err, kErrorTypeValidation, "fillchar must be a single character");
       return result;
     }
-    fillchar = utf_ptr2char((char_u *)opts->fillchar.data.string.data);
+    fillchar = utf_ptr2char(opts->fillchar.data.string.data);
   }
 
   if (HAS_KEY(opts->highlights)) {
diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index 9759bdb46e..9839f499eb 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -3456,7 +3456,7 @@ int build_stl_str_hl(win_T *wp, char_u *out, size_t outlen, char_u *fmt, int use
     wp->w_cursor.coladd = 0;
     byteval = 0;
   } else {
-    byteval = utf_ptr2char(line_ptr + wp->w_cursor.col);
+    byteval = utf_ptr2char((char *)line_ptr + wp->w_cursor.col);
   }
 
   int groupdepth = 0;
@@ -3616,7 +3616,7 @@ int build_stl_str_hl(win_T *wp, char_u *out, size_t outlen, char_u *fmt, int use
         long n = 0;
         while (group_len >= stl_items[stl_groupitems[groupdepth]].maxwid) {
           group_len -= ptr2cells(t + n);
-          n += utfc_ptr2len(t + n);
+          n += utfc_ptr2len((char *)t + n);
         }
         // }
 
@@ -4176,7 +4176,7 @@ int build_stl_str_hl(win_T *wp, char_u *out, size_t outlen, char_u *fmt, int use
       if (l > maxwid) {
         while (l >= maxwid) {
           l -= ptr2cells(t);
-          t += utfc_ptr2len(t);
+          t += utfc_ptr2len((char *)t);
         }
 
         // Early out if there isn't enough room for the truncation marker
@@ -4374,7 +4374,7 @@ int build_stl_str_hl(win_T *wp, char_u *out, size_t outlen, char_u *fmt, int use
 
         // Note: Only advance the pointer if the next
         //       character will fit in the available output space
-        trunc_p += utfc_ptr2len(trunc_p);
+        trunc_p += utfc_ptr2len((char *)trunc_p);
       }
 
       // Ignore any items in the statusline that occur after
@@ -4396,7 +4396,7 @@ int build_stl_str_hl(win_T *wp, char_u *out, size_t outlen, char_u *fmt, int use
       long trunc_len = 0;
       while (width >= maxwidth) {
         width     -= ptr2cells(trunc_p + trunc_len);
-        trunc_len += utfc_ptr2len(trunc_p + trunc_len);
+        trunc_len += utfc_ptr2len((char *)trunc_p + trunc_len);
       }
       // }
 
diff --git a/src/nvim/change.c b/src/nvim/change.c
index df7a7a00a9..bbb10d3a52 100644
--- a/src/nvim/change.c
+++ b/src/nvim/change.c
@@ -599,7 +599,7 @@ void ins_char_bytes(char_u *buf, size_t charlen)
         if (vcol > new_vcol && oldp[col + oldlen] == TAB) {
           break;
         }
-        oldlen += (size_t)utfc_ptr2len(oldp + col + oldlen);
+        oldlen += (size_t)utfc_ptr2len((char *)oldp + col + oldlen);
         // Deleted a bit too much, insert spaces.
         if (vcol > new_vcol) {
           newlen += (size_t)(vcol - new_vcol);
@@ -608,7 +608,7 @@ void ins_char_bytes(char_u *buf, size_t charlen)
       curwin->w_p_list = old_list;
     } else if (oldp[col] != NUL) {
       // normal replace
-      oldlen = (size_t)utfc_ptr2len(oldp + col);
+      oldlen = (size_t)utfc_ptr2len((char *)oldp + col);
     }
 
 
@@ -655,7 +655,7 @@ void ins_char_bytes(char_u *buf, size_t charlen)
   if (p_sm && (State & INSERT)
       && msg_silent == 0
       && !ins_compl_active()) {
-    showmatch(utf_ptr2char(buf));
+    showmatch(utf_ptr2char((char *)buf));
   }
 
   if (!p_ri || (State & REPLACE_FLAG)) {
@@ -715,7 +715,7 @@ int del_chars(long count, int fixpos)
   int bytes = 0;
   char_u *p = get_cursor_pos_ptr();
   for (long i = 0; i < count && *p != NUL; i++) {
-    int l = utfc_ptr2len(p);
+    int l = utfc_ptr2len((char *)p);
     bytes += l;
     p += l;
   }
@@ -756,7 +756,7 @@ int del_bytes(colnr_T count, bool fixpos_arg, bool use_delcombine)
   // If 'delcombine' is set and deleting (less than) one character, only
   // delete the last combining character.
   if (p_deco && use_delcombine
-      && utfc_ptr2len(oldp + col) >= count) {
+      && utfc_ptr2len((char *)oldp + col) >= count) {
     int cc[MAX_MCO];
 
     (void)utfc_ptr2char(oldp + col, cc);
@@ -765,7 +765,7 @@ int del_bytes(colnr_T count, bool fixpos_arg, bool use_delcombine)
       int n = col;
       do {
         col = n;
-        count = utf_ptr2len(oldp + n);
+        count = utf_ptr2len((char *)oldp + n);
         n += count;
       } while (utf_composinglike(oldp + col, oldp + n));
       fixpos = false;
@@ -1436,7 +1436,7 @@ int open_line(int dir, int flags, int second_line_indent, bool *did_do_comment)
             int l;
 
             for (i = 0; i < lead_len && p[i] != NUL; i += l) {
-              l = utfc_ptr2len(p + i);
+              l = utfc_ptr2len((char *)p + i);
               if (vim_strnsize(p, i + l) > repl_size) {
                 break;
               }
@@ -1459,7 +1459,7 @@ int open_line(int dir, int flags, int second_line_indent, bool *did_do_comment)
                 lead_len--;
                 memmove(p, p + 1, (size_t)(leader + lead_len - p));
               } else {
-                int l = utfc_ptr2len(p);
+                int l = utfc_ptr2len((char *)p);
 
                 if (l > 1) {
                   if (ptr2cells(p) > 1) {
@@ -1565,7 +1565,7 @@ int open_line(int dir, int flags, int second_line_indent, bool *did_do_comment)
     }
     if (curbuf->b_p_ai || (flags & OPENLINE_DELSPACES)) {
       while ((*p_extra == ' ' || *p_extra == '\t')
-             && !utf_iscomposing(utf_ptr2char(p_extra + 1))) {
+             && !utf_iscomposing(utf_ptr2char((char *)p_extra + 1))) {
         if (REPLACE_NORMAL(State)) {
           replace_push(*p_extra);
         }
diff --git a/src/nvim/charset.c b/src/nvim/charset.c
index 31c61a1398..6012c2ebc6 100644
--- a/src/nvim/charset.c
+++ b/src/nvim/charset.c
@@ -275,7 +275,7 @@ void trans_characters(char_u *buf, int bufsize)
   while (*buf != 0) {
     int trs_len;      // length of trs[]
     // Assume a multi-byte character doesn't need translation.
-    if ((trs_len = utfc_ptr2len(buf)) > 1) {
+    if ((trs_len = utfc_ptr2len((char *)buf)) > 1) {
       len -= trs_len;
     } else {
       trs = transchar_byte(*buf);
@@ -311,7 +311,7 @@ size_t transstr_len(const char *const s, bool untab)
   size_t len = 0;
 
   while (*p) {
-    const size_t l = (size_t)utfc_ptr2len((const char_u *)p);
+    const size_t l = (size_t)utfc_ptr2len(p);
     if (l > 1) {
       int pcc[MAX_MCO + 1];
       pcc[0] = utfc_ptr2char((const char_u *)p, &pcc[1]);
@@ -354,7 +354,7 @@ size_t transstr_buf(const char *const s, char *const buf, const size_t len, bool
   char *const buf_e = buf_p + len - 1;
 
   while (*p != NUL && buf_p < buf_e) {
-    const size_t l = (size_t)utfc_ptr2len((const char_u *)p);
+    const size_t l = (size_t)utfc_ptr2len(p);
     if (l > 1) {
       if (buf_p + l > buf_e) {
         break;  // Exceeded `buf` size.
@@ -424,7 +424,7 @@ char_u *str_foldcase(char_u *str, int orglen, char_u *buf, int buflen)
   int i;
   int len = orglen;
 
-#define GA_CHAR(i) ((char_u *)ga.ga_data)[i]
+#define GA_CHAR(i) ((char *)ga.ga_data)[i]
 #define GA_PTR(i) ((char_u *)ga.ga_data + (i))
 #define STR_CHAR(i) (buf == NULL ? GA_CHAR(i) : buf[i])
 #define STR_PTR(i) (buf == NULL ? GA_PTR(i) : buf + (i))
@@ -453,8 +453,8 @@ char_u *str_foldcase(char_u *str, int orglen, char_u *buf, int buflen)
   // Make each character lower case.
   i = 0;
   while (STR_CHAR(i) != NUL) {
-    int c = utf_ptr2char(STR_PTR(i));
-    int olen = utf_ptr2len(STR_PTR(i));
+    int c = utf_ptr2char((char *)STR_PTR(i));
+    int olen = utf_ptr2len((char *)STR_PTR(i));
     int lc = mb_tolower(c);
 
     // Only replace the character when it is not an invalid
@@ -492,7 +492,7 @@ char_u *str_foldcase(char_u *str, int orglen, char_u *buf, int buflen)
     }
 
     // skip to next multi-byte char
-    i += utfc_ptr2len(STR_PTR(i));
+    i += utfc_ptr2len((char *)STR_PTR(i));
   }
 
 
@@ -693,7 +693,7 @@ int ptr2cells(const char_u *p)
 {
   // For UTF-8 we need to look at more bytes if the first byte is >= 0x80.
   if (*p >= 0x80) {
-    return utf_ptr2cells(p);
+    return utf_ptr2cells((char *)p);
   }
 
   // For DBCS we can tell the cell count from the first byte.
@@ -727,7 +727,7 @@ int vim_strnsize(char_u *s, int len)
   assert(s != NULL);
   int size = 0;
   while (*s != NUL && --len >= 0) {
-    int l = utfc_ptr2len(s);
+    int l = utfc_ptr2len((char *)s);
     size += ptr2cells(s);
     s += l;
     len -= l - 1;
@@ -806,7 +806,7 @@ bool vim_iswordp_buf(const char_u *const p, buf_T *const buf)
   int c = *p;
 
   if (MB_BYTE2LEN(c) > 1) {
-    c = utf_ptr2char(p);
+    c = utf_ptr2char((char *)p);
   }
   return vim_iswordc_buf(c, buf);
 }
@@ -957,7 +957,7 @@ void getvcol(win_T *wp, pos_T *pos, colnr_T *start, colnr_T *cursor, colnr_T *en
         // For utf-8, if the byte is >= 0x80, need to look at
         // further bytes to find the cell width.
         if (c >= 0x80) {
-          incr = utf_ptr2cells(ptr);
+          incr = utf_ptr2cells((char *)ptr);
         } else {
           incr = g_chartab[c] & CT_CELL_MASK;
         }
@@ -1070,7 +1070,7 @@ void getvvcol(win_T *wp, pos_T *pos, colnr_T *start, colnr_T *cursor, colnr_T *e
     char_u *ptr = ml_get_buf(wp->w_buffer, pos->lnum, false);
 
     if (pos->col < (colnr_T)STRLEN(ptr)) {
-      int c = utf_ptr2char(ptr + pos->col);
+      int c = utf_ptr2char((char *)ptr + pos->col);
       if ((c != TAB) && vim_isprintc(c)) {
         endadd = (colnr_T)(char2cells(c) - 1);
         if (coladd > endadd) {
diff --git a/src/nvim/cursor.c b/src/nvim/cursor.c
index 87835ec50a..6208efc9c8 100644
--- a/src/nvim/cursor.c
+++ b/src/nvim/cursor.c
@@ -459,7 +459,7 @@ bool leftcol_changed(void)
 
 int gchar_cursor(void)
 {
-  return utf_ptr2char(get_cursor_pos_ptr());
+  return utf_ptr2char((char *)get_cursor_pos_ptr());
 }
 
 /// Write a character at the current cursor position.
diff --git a/src/nvim/diff.c b/src/nvim/diff.c
index 6b606f50a1..7e296ebf52 100644
--- a/src/nvim/diff.c
+++ b/src/nvim/diff.c
@@ -750,10 +750,10 @@ static int diff_write_buffer(buf_T *buf, diffin_T *din)
           c = NUL;
         } else {
           // xdiff doesn't support ignoring case, fold-case the text.
-          c = utf_ptr2char(s);
+          c = utf_ptr2char((char *)s);
           c = utf_fold(c);
         }
-        const int orig_len = utfc_ptr2len(s);
+        const int orig_len = utfc_ptr2len((char *)s);
         if (utf_char2bytes(c, cbuf) != orig_len) {
           // TODO(Bram): handle byte length difference
           memmove(ptr + len, s, (size_t)orig_len);
@@ -1937,15 +1937,15 @@ static bool diff_equal_entry(diff_T *dp, int idx1, int idx2)
 // ignoring case) return true and set "len" to the number of bytes.
 static bool diff_equal_char(const char_u *const p1, const char_u *const p2, int *const len)
 {
-  const int l = utfc_ptr2len(p1);
+  const int l = utfc_ptr2len((char *)p1);
 
-  if (l != utfc_ptr2len(p2)) {
+  if (l != utfc_ptr2len((char *)p2)) {
     return false;
   }
   if (l > 1) {
     if (STRNCMP(p1, p2, l) != 0
         && (!(diff_flags & DIFF_ICASE)
-            || utf_fold(utf_ptr2char(p1)) != utf_fold(utf_ptr2char(p2)))) {
+            || utf_fold(utf_ptr2char((char *)p1)) != utf_fold(utf_ptr2char((char *)p2)))) {
       return false;
     }
     *len = l;
diff --git a/src/nvim/edit.c b/src/nvim/edit.c
index a608612af5..3821cd3f41 100644
--- a/src/nvim/edit.c
+++ b/src/nvim/edit.c
@@ -440,7 +440,7 @@ static void insert_enter(InsertState *s)
       if (s->ptr[1] == NUL) {
         curwin->w_cursor.col++;
       } else {
-        s->i = utfc_ptr2len(s->ptr);
+        s->i = utfc_ptr2len((char *)s->ptr);
         if (s->ptr[s->i] == NUL) {
           curwin->w_cursor.col += s->i;
         }
@@ -727,7 +727,7 @@ static int insert_execute(VimState *state, int key)
 
         if (str != NULL) {
           for (p = str; *p != NUL; MB_PTR_ADV(p)) {
-            ins_compl_addleader(utf_ptr2char(p));
+            ins_compl_addleader(utf_ptr2char((char *)p));
           }
           xfree(str);
         } else {
@@ -1332,7 +1332,7 @@ normalchar:
         if (*str != NUL && stop_arrow() != FAIL) {
           // Insert the new value of v:char literally.
           for (p = str; *p != NUL; MB_PTR_ADV(p)) {
-            s->c = utf_ptr2char(p);
+            s->c = utf_ptr2char((char *)p);
             if (s->c == CAR || s->c == K_KENTER || s->c == NL) {
               ins_eol(s->c);
             } else {
@@ -1891,7 +1891,7 @@ void change_indent(int type, int amount, int round, int replaced, int call_chang
     while (vcol <= (int)curwin->w_virtcol) {
       last_vcol = vcol;
       if (new_cursor_col >= 0) {
-        new_cursor_col += utfc_ptr2len(ptr + new_cursor_col);
+        new_cursor_col += utfc_ptr2len((char *)ptr + new_cursor_col);
       } else {
         new_cursor_col++;
       }
@@ -2061,7 +2061,7 @@ static bool del_char_after_col(int limit_col)
     // composing character.
     mb_adjust_cursor();
     while (curwin->w_cursor.col < (colnr_T)limit_col) {
-      int l = utf_ptr2len(get_cursor_pos_ptr());
+      int l = utf_ptr2len((char *)get_cursor_pos_ptr());
 
       if (l == 0) {  // end of line
         break;
@@ -2566,8 +2566,8 @@ static void ins_compl_longest_match(compl_T *match)
     p = compl_leader;
     s = match->cp_str;
     while (*p != NUL) {
-      c1 = utf_ptr2char(p);
-      c2 = utf_ptr2char(s);
+      c1 = utf_ptr2char((char *)p);
+      c2 = utf_ptr2char((char *)s);
 
       if ((match->cp_flags & CP_ICASE)
           ? (mb_tolower(c1) != mb_tolower(c2))
@@ -3108,7 +3108,7 @@ static void ins_compl_files(int count, char_u **files, int thesaurus, int flags,
             // different classes, only separate words
             // with single-byte non-word characters.
             while (*ptr != NUL) {
-              const int l = utfc_ptr2len(ptr);
+              const int l = utfc_ptr2len((char *)ptr);
 
               if (l < 2 && !vim_iswordc(*ptr)) {
                 break;
@@ -3150,7 +3150,7 @@ char_u *find_word_start(char_u *ptr)
   FUNC_ATTR_PURE
 {
   while (*ptr != NUL && *ptr != '\n' && mb_get_class(ptr) <= 1) {
-    ptr += utfc_ptr2len(ptr);
+    ptr += utfc_ptr2len((char *)ptr);
   }
   return ptr;
 }
@@ -3165,7 +3165,7 @@ char_u *find_word_end(char_u *ptr)
   const int start_class = mb_get_class(ptr);
   if (start_class > 1) {
     while (*ptr != NUL) {
-      ptr += utfc_ptr2len(ptr);
+      ptr += utfc_ptr2len((char *)ptr);
       if (mb_get_class(ptr) != start_class) {
         break;
       }
@@ -3602,7 +3602,7 @@ static void ins_compl_addfrommatch(void)
     }
   }
   p += len;
-  c = utf_ptr2char(p);
+  c = utf_ptr2char((char *)p);
   ins_compl_addleader(c);
 }
 
@@ -5251,10 +5251,10 @@ static int ins_complete(int c, bool enable_pum)
         char_u *p = line + startcol;
 
         MB_PTR_BACK(line, p);
-        while (p > line && vim_isfilec(utf_ptr2char(p))) {
+        while (p > line && vim_isfilec(utf_ptr2char((char *)p))) {
           MB_PTR_BACK(line, p);
         }
-        if (p == line && vim_isfilec(utf_ptr2char(p))) {
+        if (p == line && vim_isfilec(utf_ptr2char((char *)p))) {
           startcol = 0;
         } else {
           startcol = (int)(p - line) + 1;
@@ -5590,7 +5590,7 @@ static unsigned quote_meta(char_u *dest, char_u *src, int len)
       *dest++ = *src;
     }
     // Copy remaining bytes of a multibyte character.
-    const int mb_len = utfc_ptr2len(src) - 1;
+    const int mb_len = utfc_ptr2len((char *)src) - 1;
     if (mb_len > 0 && len >= mb_len) {
       for (int i = 0; i < mb_len; i++) {
         len--;
@@ -5759,9 +5759,8 @@ static void insert_special(int c, int allow_modmask, int ctrlv)
  */
 #define ISSPECIAL(c)   ((c) < ' ' || (c) >= DEL || (c) == '0' || (c) == '^')
 
-#define WHITECHAR(cc) ( \
-                        ascii_iswhite(cc) \
-                        && !utf_iscomposing(utf_ptr2char(get_cursor_pos_ptr() + 1)))
+#define WHITECHAR(cc) (ascii_iswhite(cc) \
+                       && !utf_iscomposing(utf_ptr2char((char *)get_cursor_pos_ptr() + 1)))
 
 ///
 /// "flags": INSCHAR_FORMAT - force formatting
@@ -6903,7 +6902,7 @@ int oneright(void)
 
     // Adjust for multi-wide char (excluding TAB)
     ptr = get_cursor_pos_ptr();
-    coladvance(getviscol() + ((*ptr != TAB && vim_isprintc(utf_ptr2char(ptr))) ?
+    coladvance(getviscol() + ((*ptr != TAB && vim_isprintc(utf_ptr2char((char *)ptr))) ?
                               ptr2cells(ptr) : 1));
     curwin->w_set_curswant = true;
     // Return OK if the cursor moved, FAIL otherwise (at window edge).
@@ -6916,7 +6915,7 @@ int oneright(void)
     return FAIL;            // already at the very end
   }
 
-  l = utfc_ptr2len(ptr);
+  l = utfc_ptr2len((char *)ptr);
 
   // move "l" bytes right, but don't end up on the NUL, unless 'virtualedit'
   // contains "onemore".
@@ -6957,7 +6956,7 @@ int oneleft(void)
 
       // Adjust for multi-wide char (not a TAB)
       ptr = get_cursor_pos_ptr();
-      if (*ptr != TAB && vim_isprintc(utf_ptr2char(ptr))
+      if (*ptr != TAB && vim_isprintc(utf_ptr2char((char *)ptr))
           && ptr2cells(ptr) > 1) {
         curwin->w_cursor.coladd = 0;
       }
@@ -7249,7 +7248,7 @@ void replace_push(int c)
  */
 int replace_push_mb(char_u *p)
 {
-  int l = utfc_ptr2len(p);
+  int l = utfc_ptr2len((char *)p);
   int j;
 
   for (j = l - 1; j >= 0; --j) {
@@ -7337,7 +7336,7 @@ static void mb_replace_pop_ins(int cc)
     for (i = 1; i < n; i++) {
       buf[i] = (char_u)replace_pop();
     }
-    if (utf_iscomposing(utf_ptr2char(buf))) {
+    if (utf_iscomposing(utf_ptr2char((char *)buf))) {
       ins_bytes_len(buf, (size_t)n);
     } else {
       // Not a composing char, put it back.
@@ -7403,7 +7402,7 @@ static void replace_do_bs(int limit_col)
       vcol = start_vcol;
       for (i = 0; i < ins_len; i++) {
         vcol += win_chartabsize(curwin, p + i, vcol);
-        i += utfc_ptr2len(p) - 1;
+        i += utfc_ptr2len((char *)p) - 1;
       }
       vcol -= start_vcol;
 
@@ -8796,7 +8795,7 @@ static void ins_right(void)
     if (virtual_active()) {
       oneright();
     } else {
-      curwin->w_cursor.col += utfc_ptr2len(get_cursor_pos_ptr());
+      curwin->w_cursor.col += utfc_ptr2len((char *)get_cursor_pos_ptr());
     }
 
     revins_legal++;
@@ -9305,7 +9304,7 @@ int ins_copychar(linenr_T lnum)
     ptr = prev_ptr;
   }
 
-  c = utf_ptr2char(ptr);
+  c = utf_ptr2char((char *)ptr);
   if (c == NUL) {
     vim_beep(BO_COPY);
   }
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 548dd96444..901976bb16 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -2656,7 +2656,7 @@ bool next_for_item(void *fi_void, char *arg)
   }
 
   if (fi->fi_string != NULL) {
-    const int len = utfc_ptr2len((char_u *)fi->fi_string + fi->fi_byte_idx);
+    const int len = utfc_ptr2len(fi->fi_string + fi->fi_byte_idx);
     if (len == 0) {
       return false;
     }
@@ -7681,7 +7681,7 @@ int buf_byteidx_to_charidx(buf_T *buf, int lnum, int byteidx)
   char *t = str;
   int count;
   for (count = 0; *t != NUL && t <= str + byteidx; count++) {
-    t += utfc_ptr2len((char_u *)t);
+    t += utfc_ptr2len(t);
   }
 
   // In insert mode, when the cursor is at the end of a non-empty line,
@@ -7714,7 +7714,7 @@ int buf_charidx_to_byteidx(buf_T *buf, int lnum, int charidx)
   // Convert the character offset to a byte offset
   char *t = str;
   while (*t != NUL && --charidx > 0) {
-    t += utfc_ptr2len((char_u *)t);
+    t += utfc_ptr2len(t);
   }
 
   return t - str;
@@ -10409,7 +10409,7 @@ char *do_string_sub(char *str, char *pat, char *sub, typval_T *expr, char *flags
       if (regmatch.startp[0] == regmatch.endp[0]) {
         if ((char_u *)zero_width == regmatch.startp[0]) {
           // avoid getting stuck on a match with an empty string
-          int i = utfc_ptr2len((char_u *)tail);
+          int i = utfc_ptr2len(tail);
           memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
           ga.ga_len += i;
           tail += i;
diff --git a/src/nvim/eval/decode.c b/src/nvim/eval/decode.c
index ec9a30ad65..93e0a6cfb7 100644
--- a/src/nvim/eval/decode.c
+++ b/src/nvim/eval/decode.c
@@ -375,7 +375,7 @@ static inline int parse_json_string(const char *const buf, const size_t buf_len,
                 "inside string: %.*s"), LENP(p, e));
         goto parse_json_string_fail;
       }
-      const int ch = utf_ptr2char((char_u *)p);
+      const int ch = utf_ptr2char(p);
       // All characters above U+007F are encoded using two or more bytes
       // and thus cannot possibly be equal to *p. But utf_ptr2char({0xFF,
       // 0}) will return 0xFF, even though 0xFF cannot start any UTF-8
@@ -392,7 +392,7 @@ static inline int parse_json_string(const char *const buf, const size_t buf_len,
         goto parse_json_string_fail;
       }
       const size_t ch_len = (size_t)utf_char2len(ch);
-      assert(ch_len == (size_t)(ch ? utf_ptr2len((char_u *)p) : 1));
+      assert(ch_len == (size_t)(ch ? utf_ptr2len(p) : 1));
       len += ch_len;
       p += ch_len;
     }
diff --git a/src/nvim/eval/encode.c b/src/nvim/eval/encode.c
index 963837fefc..de93ddc70d 100644
--- a/src/nvim/eval/encode.c
+++ b/src/nvim/eval/encode.c
@@ -611,8 +611,8 @@ static inline int convert_to_json_string(garray_T *const gap, const char *const
 #define ENCODE_RAW(ch) \
   (ch >= 0x20 && utf_printable(ch))
     for (size_t i = 0; i < utf_len;) {
-      const int ch = utf_ptr2char((char_u *)utf_buf + i);
-      const size_t shift = (ch == 0 ? 1 : ((size_t)utf_ptr2len((char_u *)utf_buf + i)));
+      const int ch = utf_ptr2char(utf_buf + i);
+      const size_t shift = (ch == 0 ? 1 : ((size_t)utf_ptr2len(utf_buf + i)));
       assert(shift > 0);
       i += shift;
       switch (ch) {
@@ -651,11 +651,11 @@ static inline int convert_to_json_string(garray_T *const gap, const char *const
     ga_append(gap, '"');
     ga_grow(gap, (int)str_len);
     for (size_t i = 0; i < utf_len;) {
-      const int ch = utf_ptr2char((char_u *)utf_buf + i);
+      const int ch = utf_ptr2char(utf_buf + i);
       const size_t shift = (ch == 0 ? 1 : ((size_t)utf_char2len(ch)));
       assert(shift > 0);
       // Is false on invalid unicode, but this should already be handled.
-      assert(ch == 0 || shift == ((size_t)utf_ptr2len((char_u *)utf_buf + i)));
+      assert(ch == 0 || shift == ((size_t)utf_ptr2len(utf_buf + i)));
       switch (ch) {
       case BS:
       case TAB:
diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index 92c60e394a..be43c3010a 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -733,9 +733,9 @@ static void byteidx(typval_T *argvars, typval_T *rettv, int comp)
       return;
     }
     if (comp) {
-      t += utf_ptr2len((const char_u *)t);
+      t += utf_ptr2len(t);
     } else {
-      t += utfc_ptr2len((const char_u *)t);
+      t += utfc_ptr2len(t);
     }
   }
   rettv->vval.v_number = (varnumber_T)(t - str);
@@ -894,7 +894,7 @@ static void f_char2nr(typval_T *argvars, typval_T *rettv, FunPtr fptr)
     }
   }
 
-  rettv->vval.v_number = utf_ptr2char((const char_u *)tv_get_string(&argvars[0]));
+  rettv->vval.v_number = utf_ptr2char(tv_get_string(&argvars[0]));
 }
 
 /// Get the current cursor column and store it in 'rettv'.
@@ -925,7 +925,7 @@ static void get_col(typval_T *argvars, typval_T *rettv, bool charcol)
         if (curwin->w_cursor.coladd >=
             (colnr_T)win_chartabsize(curwin, p, curwin->w_virtcol - curwin->w_cursor.coladd)) {
           int l;
-          if (*p != NUL && p[(l = utfc_ptr2len(p))] == NUL) {
+          if (*p != NUL && p[(l = utfc_ptr2len((char *)p))] == NUL) {
             col += l;
           }
         }
@@ -968,7 +968,7 @@ static void f_charidx(typval_T *argvars, typval_T *rettv, FunPtr fptr)
     return;
   }
 
-  int (*ptr2len)(const char_u *);
+  int (*ptr2len)(const char *);
   if (countcc) {
     ptr2len = utf_ptr2len;
   } else {
@@ -981,7 +981,7 @@ static void f_charidx(typval_T *argvars, typval_T *rettv, FunPtr fptr)
     if (*p == NUL) {
       return;
     }
-    p += ptr2len((const char_u *)p);
+    p += ptr2len(p);
   }
 
   rettv->vval.v_number = len > 0 ? len - 1 : 0;
@@ -5691,7 +5691,7 @@ static void get_maparg(typval_T *argvars, typval_T *rettv, int exact)
     return;
   }
 
-  mode = get_map_mode((char_u **)&which, 0);
+  mode = get_map_mode((char **)&which, 0);
 
   char_u *keys_simplified
     = replace_termcodes(keys, STRLEN(keys), &keys_buf, flags, &did_simplify, CPO_TO_CPO_FLAGS);
@@ -5894,7 +5894,7 @@ static void find_some_match(typval_T *const argvars, typval_T *const rettv,
         idx++;
       } else {
         startcol = (colnr_T)(regmatch.startp[0]
-                             + utfc_ptr2len(regmatch.startp[0]) - str);
+                             + utfc_ptr2len((char *)regmatch.startp[0]) - str);
         if (startcol > (colnr_T)len || str + startcol <= regmatch.startp[0]) {
           match = false;
           break;
@@ -8062,7 +8062,7 @@ static void f_screenchar(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   } else {
     ScreenGrid *grid = &default_grid;
     screenchar_adjust_grid(&grid, &row, &col);
-    c = utf_ptr2char(grid->chars[grid->line_offset[row] + col]);
+    c = utf_ptr2char((char *)grid->chars[grid->line_offset[row] + col]);
   }
   rettv->vval.v_number = c;
 }
@@ -8660,7 +8660,7 @@ static void f_setcharsearch(typval_T *argvars, typval_T *rettv, FunPtr fptr)
     if (csearch != NULL) {
       int pcc[MAX_MCO];
       const int c = utfc_ptr2char(csearch, pcc);
-      set_last_csearch(c, csearch, utfc_ptr2len(csearch));
+      set_last_csearch(c, csearch, utfc_ptr2len((char *)csearch));
     }
 
     di = tv_dict_find(d, S_LEN("forward"));
@@ -9796,7 +9796,7 @@ static void f_split(typval_T *argvars, typval_T *rettv, FunPtr fptr)
         col = 0;
       } else {
         // Don't get stuck at the same match.
-        col = utfc_ptr2len(regmatch.endp[0]);
+        col = utfc_ptr2len((char *)regmatch.endp[0]);
       }
       str = (const char *)regmatch.endp[0];
     }
@@ -9856,8 +9856,8 @@ static void f_str2list(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   tv_list_alloc_ret(rettv, kListLenUnknown);
   const char_u *p = (const char_u *)tv_get_string(&argvars[0]);
 
-  for (; *p != NUL; p += utf_ptr2len(p)) {
-    tv_list_append_number(rettv->vval.v_list, utf_ptr2char(p));
+  for (; *p != NUL; p += utf_ptr2len((char *)p)) {
+    tv_list_append_number(rettv->vval.v_list, utf_ptr2char((char *)p));
   }
 }
 
@@ -9976,11 +9976,11 @@ static void f_strgetchar(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 
   while (charidx >= 0 && byteidx < len) {
     if (charidx == 0) {
-      rettv->vval.v_number = utf_ptr2char((const char_u *)str + byteidx);
+      rettv->vval.v_number = utf_ptr2char(str + byteidx);
       break;
     }
     charidx--;
-    byteidx += utf_ptr2len((const char_u *)str + byteidx);
+    byteidx += utf_ptr2len(str + byteidx);
   }
 }
 
@@ -10085,7 +10085,7 @@ static void f_strcharpart(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   if (!error) {
     if (nchar > 0) {
       while (nchar > 0 && (size_t)nbyte < slen) {
-        nbyte += utf_ptr2len((const char_u *)p + nbyte);
+        nbyte += utf_ptr2len(p + nbyte);
         nchar--;
       }
     } else {
@@ -10101,7 +10101,7 @@ static void f_strcharpart(typval_T *argvars, typval_T *rettv, FunPtr fptr)
       if (off < 0) {
         len += 1;
       } else {
-        len += utf_ptr2len((const char_u *)p + off);
+        len += utf_ptr2len(p + off);
       }
       charlen--;
     }
@@ -10164,7 +10164,7 @@ static void f_strpart(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 
     // length in characters
     for (off = n; off < (int)slen && len > 0; len--) {
-      off += utfc_ptr2len((char_u *)p + off);
+      off += utfc_ptr2len(p + off);
     }
     len = off - n;
   }
@@ -10935,16 +10935,16 @@ static void f_tr(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   bool first = true;
   while (*in_str != NUL) {
     const char *cpstr = in_str;
-    const int inlen = utfc_ptr2len((const char_u *)in_str);
+    const int inlen = utfc_ptr2len(in_str);
     int cplen = inlen;
     int idx = 0;
     int fromlen;
     for (const char *p = fromstr; *p != NUL; p += fromlen) {
-      fromlen = utfc_ptr2len((const char_u *)p);
+      fromlen = utfc_ptr2len(p);
       if (fromlen == inlen && STRNCMP(in_str, p, inlen) == 0) {
         int tolen;
         for (p = tostr; *p != NUL; p += tolen) {
-          tolen = utfc_ptr2len((const char_u *)p);
+          tolen = utfc_ptr2len(p);
           if (idx-- == 0) {
             cplen = tolen;
             cpstr = (char *)p;
@@ -10966,7 +10966,7 @@ static void f_tr(typval_T *argvars, typval_T *rettv, FunPtr fptr)
       first = false;
       int tolen;
       for (const char *p = tostr; *p != NUL; p += tolen) {
-        tolen = utfc_ptr2len((const char_u *)p);
+        tolen = utfc_ptr2len(p);
         idx--;
       }
       if (idx != 0) {
@@ -11029,14 +11029,14 @@ static void f_trim(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   if (dir == 0 || dir == 1) {
     // Trim leading characters
     while (*head != NUL) {
-      c1 = utf_ptr2char(head);
+      c1 = utf_ptr2char((char *)head);
       if (mask == NULL) {
         if (c1 > ' ' && c1 != 0xa0) {
           break;
         }
       } else {
         for (p = mask; *p != NUL; MB_PTR_ADV(p)) {
-          if (c1 == utf_ptr2char(p)) {
+          if (c1 == utf_ptr2char((char *)p)) {
             break;
           }
         }
@@ -11054,14 +11054,14 @@ static void f_trim(typval_T *argvars, typval_T *rettv, FunPtr fptr)
     for (; tail > head; tail = prev) {
       prev = tail;
       MB_PTR_BACK(head, prev);
-      c1 = utf_ptr2char(prev);
+      c1 = utf_ptr2char((char *)prev);
       if (mask == NULL) {
         if (c1 > ' ' && c1 != 0xa0) {
           break;
         }
       } else {
         for (p = mask; *p != NUL; MB_PTR_ADV(p)) {
-          if (c1 == utf_ptr2char(p)) {
+          if (c1 == utf_ptr2char((char *)p)) {
             break;
           }
         }
diff --git a/src/nvim/ex_cmds.c b/src/nvim/ex_cmds.c
index 5b831a21c0..7aab27577a 100644
--- a/src/nvim/ex_cmds.c
+++ b/src/nvim/ex_cmds.c
@@ -850,7 +850,7 @@ void ex_retab(exarg_T *eap)
         emsg(_(e_resulting_text_too_long));
         break;
       }
-      col += utfc_ptr2len((char_u *)ptr + col);
+      col += utfc_ptr2len(ptr + col);
     }
     if (new_line == NULL) {                 // out of memory
       break;
@@ -3785,7 +3785,7 @@ static buf_T *do_sub(exarg_T *eap, proftime_T timeout, bool do_buf_event, handle
             skip_match = true;
           } else {
             // search for a match at next column
-            matchcol += utfc_ptr2len((char_u *)sub_firstline + matchcol);
+            matchcol += utfc_ptr2len(sub_firstline + matchcol);
           }
           // match will be pushed to preview_lines, bring it into a proper state
           current_match.start.col = matchcol;
@@ -4179,7 +4179,7 @@ static buf_T *do_sub(exarg_T *eap, proftime_T timeout, bool do_buf_event, handle
                 p1 = new_start - 1;
               }
             } else {
-              p1 += utfc_ptr2len((char_u *)p1) - 1;
+              p1 += utfc_ptr2len(p1) - 1;
             }
           }
           size_t new_endcol = STRLEN(new_start);
@@ -5464,7 +5464,7 @@ void fix_help_buffer(void)
                   // illegal byte sequence is found.
                   if ((char_u)(*s) >= 0x80 && this_utf != kFalse) {
                     this_utf = kTrue;
-                    const int l = utf_ptr2len((char_u *)s);
+                    const int l = utf_ptr2len(s);
                     if (l == 1) {
                       this_utf = kFalse;
                     }
@@ -5613,7 +5613,7 @@ static void helptags_one(char *dir, const char *ext, const char *tagfname, bool
         for (s = (char *)IObuff; *s != NUL; s++) {
           if ((char_u)(*s) >= 0x80) {
             this_utf8 = kTrue;
-            const int l = utf_ptr2len((char_u *)s);
+            const int l = utf_ptr2len(s);
             if (l == 1) {
               // Illegal UTF-8 byte sequence.
               this_utf8 = kFalse;
diff --git a/src/nvim/ex_docmd.c b/src/nvim/ex_docmd.c
index a54d1a14ce..eed2a38a4f 100644
--- a/src/nvim/ex_docmd.c
+++ b/src/nvim/ex_docmd.c
@@ -3381,7 +3381,7 @@ const char *set_one_cmd_context(expand_T *xp, const char *buff)
     xp->xp_pattern = (char *)skipwhite((const char_u *)arg);
     p = (const char *)xp->xp_pattern;
     while (*p != NUL) {
-      c = utf_ptr2char((const char_u *)p);
+      c = utf_ptr2char(p);
       if (c == '\\' && p[1] != NUL) {
         p++;
       } else if (c == '`') {
@@ -3399,11 +3399,11 @@ const char *set_one_cmd_context(expand_T *xp, const char *buff)
                || ascii_iswhite(c)) {
         len = 0;          // avoid getting stuck when space is in 'isfname'
         while (*p != NUL) {
-          c = utf_ptr2char((const char_u *)p);
+          c = utf_ptr2char(p);
           if (c == '`' || vim_isfilec_or_wc(c)) {
             break;
           }
-          len = (size_t)utfc_ptr2len((const char_u *)p);
+          len = (size_t)utfc_ptr2len(p);
           MB_PTR_ADV(p);
         }
         if (in_quote) {
@@ -6030,7 +6030,7 @@ static char *uc_split_args(char *arg, size_t *lenp)
       }
       len += 3;       // ","
     } else {
-      const int charlen = utfc_ptr2len((char_u *)p);
+      const int charlen = utfc_ptr2len(p);
 
       len += charlen;
       p += charlen;
@@ -8167,7 +8167,7 @@ static void do_exmap(exarg_T *eap, int isabbrev)
 {
   int mode;
   char *cmdp = eap->cmd;
-  mode = get_map_mode((char_u **)&cmdp, eap->forceit || isabbrev);
+  mode = get_map_mode(&cmdp, eap->forceit || isabbrev);
 
   switch (do_map((*cmdp == 'n') ? 2 : (*cmdp == 'u'),
                  (char_u *)eap->arg, mode, isabbrev)) {
@@ -8828,7 +8828,7 @@ static void ex_normal(exarg_T *eap)
 
     // Count the number of characters to be escaped.
     for (p = eap->arg; *p != NUL; p++) {
-      for (l = utfc_ptr2len((char_u *)p) - 1; l > 0; l--) {
+      for (l = utfc_ptr2len(p) - 1; l > 0; l--) {
         if (*++p == (char)K_SPECIAL) {  // trailbyte K_SPECIAL
           len += 2;
         }
@@ -8839,7 +8839,7 @@ static void ex_normal(exarg_T *eap)
       len = 0;
       for (p = eap->arg; *p != NUL; p++) {
         arg[len++] = *p;
-        for (l = utfc_ptr2len((char_u *)p) - 1; l > 0; l--) {
+        for (l = utfc_ptr2len(p) - 1; l > 0; l--) {
           arg[len++] = *++p;
           if (*p == (char)K_SPECIAL) {
             arg[len++] = (char)KS_SPECIAL;
diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index faedba5e5a..1932c02cf2 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -1780,7 +1780,7 @@ static int command_line_handle_key(CommandLineState *s)
         }
 
         if (mb_get_class(p) != i) {
-          p += utfc_ptr2len(p);
+          p += utfc_ptr2len((char *)p);
         }
       }
 
@@ -1964,7 +1964,7 @@ static int command_line_handle_key(CommandLineState *s)
       }
 
       ccline.cmdspos += cells;
-      ccline.cmdpos += utfc_ptr2len(ccline.cmdbuff + ccline.cmdpos);
+      ccline.cmdpos += utfc_ptr2len((char *)ccline.cmdbuff + ccline.cmdpos);
     } while ((s->c == K_S_RIGHT || s->c == K_C_RIGHT
               || (mod_mask & (MOD_MASK_SHIFT|MOD_MASK_CTRL)))
              && ccline.cmdbuff[ccline.cmdpos] != ' ');
@@ -2039,7 +2039,7 @@ static int command_line_handle_key(CommandLineState *s)
 
       // Count ">" for double-wide char that doesn't fit.
       correct_screencol(ccline.cmdpos, cells, &ccline.cmdspos);
-      ccline.cmdpos += utfc_ptr2len(ccline.cmdbuff + ccline.cmdpos) - 1;
+      ccline.cmdpos += utfc_ptr2len((char *)ccline.cmdbuff + ccline.cmdpos) - 1;
       ccline.cmdspos += cells;
     }
     return command_line_not_changed(s);
@@ -2571,7 +2571,7 @@ static int cmd_screencol(int bytepos)
   }
 
   for (int i = 0; i < ccline.cmdlen && i < bytepos;
-       i += utfc_ptr2len(ccline.cmdbuff + i)) {
+       i += utfc_ptr2len((char *)ccline.cmdbuff + i)) {
     int c = cmdline_charsize(i);
     // Count ">" for double-wide multi-byte char that doesn't fit.
     correct_screencol(i, c, &col);
@@ -2590,8 +2590,8 @@ static int cmd_screencol(int bytepos)
 /// character that doesn't fit, so that a ">" must be displayed.
 static void correct_screencol(int idx, int cells, int *col)
 {
-  if (utfc_ptr2len(ccline.cmdbuff + idx) > 1
-      && utf_ptr2cells(ccline.cmdbuff + idx) > 1
+  if (utfc_ptr2len((char *)ccline.cmdbuff + idx) > 1
+      && utf_ptr2cells((char *)ccline.cmdbuff + idx) > 1
       && (*col) % Columns + cells > Columns) {
     (*col)++;
   }
@@ -2996,7 +2996,7 @@ static void draw_cmdline(int start, int len)
   if (cmdline_star > 0) {
     for (int i = 0; i < len; i++) {
       msg_putchar('*');
-      i += utfc_ptr2len(ccline.cmdbuff + start + i) - 1;
+      i += utfc_ptr2len((char *)ccline.cmdbuff + start + i) - 1;
     }
   } else if (p_arshape && !p_tbidi && len > 0) {
     bool do_arabicshape = false;
@@ -3029,7 +3029,7 @@ static void draw_cmdline(int start, int len)
     }
 
     int newlen = 0;
-    if (utf_iscomposing(utf_ptr2char(ccline.cmdbuff + start))) {
+    if (utf_iscomposing(utf_ptr2char((char *)ccline.cmdbuff + start))) {
       // Prepend a space to draw the leading composing char on.
       arshape_buf[0] = ' ';
       newlen = 1;
@@ -3055,7 +3055,7 @@ static void draw_cmdline(int start, int len)
           if (i + mb_l >= start + len) {
             nc = NUL;
           } else {
-            nc = utf_ptr2char(p + mb_l);
+            nc = utf_ptr2char((char *)p + mb_l);
           }
         } else {
           // Displaying from left to right.
@@ -3261,7 +3261,7 @@ void unputcmdline(void)
   if (ccline.cmdlen == ccline.cmdpos && !ui_has(kUICmdline)) {
     msg_putchar(' ');
   } else {
-    draw_cmdline(ccline.cmdpos, utfc_ptr2len(ccline.cmdbuff + ccline.cmdpos));
+    draw_cmdline(ccline.cmdpos, utfc_ptr2len((char *)ccline.cmdbuff + ccline.cmdpos));
   }
   msg_no_more = false;
   cursorcmd();
@@ -3297,13 +3297,13 @@ void put_on_cmdline(char_u *str, int len, int redraw)
   } else {
     // Count nr of characters in the new string.
     m = 0;
-    for (i = 0; i < len; i += utfc_ptr2len(str + i)) {
+    for (i = 0; i < len; i += utfc_ptr2len((char *)str + i)) {
       m++;
     }
     // Count nr of bytes in cmdline that are overwritten by these
     // characters.
     for (i = ccline.cmdpos; i < ccline.cmdlen && m > 0;
-         i += utfc_ptr2len(ccline.cmdbuff + i)) {
+         i += utfc_ptr2len((char *)ccline.cmdbuff + i)) {
       m--;
     }
     if (i < ccline.cmdlen) {
@@ -3321,17 +3321,17 @@ void put_on_cmdline(char_u *str, int len, int redraw)
     // When the inserted text starts with a composing character,
     // backup to the character before it.  There could be two of them.
     i = 0;
-    c = utf_ptr2char(ccline.cmdbuff + ccline.cmdpos);
+    c = utf_ptr2char((char *)ccline.cmdbuff + ccline.cmdpos);
     while (ccline.cmdpos > 0 && utf_iscomposing(c)) {
       i = utf_head_off(ccline.cmdbuff, ccline.cmdbuff + ccline.cmdpos - 1) + 1;
       ccline.cmdpos -= i;
       len += i;
-      c = utf_ptr2char(ccline.cmdbuff + ccline.cmdpos);
+      c = utf_ptr2char((char *)ccline.cmdbuff + ccline.cmdpos);
     }
     if (i == 0 && ccline.cmdpos > 0 && arabic_maycombine(c)) {
       // Check the previous character for Arabic combining pair.
       i = utf_head_off(ccline.cmdbuff, ccline.cmdbuff + ccline.cmdpos - 1) + 1;
-      if (arabic_combine(utf_ptr2char(ccline.cmdbuff + ccline.cmdpos - i), c)) {
+      if (arabic_combine(utf_ptr2char((char *)ccline.cmdbuff + ccline.cmdpos - i), c)) {
         ccline.cmdpos -= i;
         len += i;
       } else {
@@ -3379,7 +3379,7 @@ void put_on_cmdline(char_u *str, int len, int redraw)
     if (ccline.cmdspos + c < m) {
       ccline.cmdspos += c;
     }
-    c = utfc_ptr2len(ccline.cmdbuff + ccline.cmdpos) - 1;
+    c = utfc_ptr2len((char *)ccline.cmdbuff + ccline.cmdpos) - 1;
     if (c > len - i - 1) {
       c = len - i - 1;
     }
@@ -3464,7 +3464,7 @@ static bool cmdline_paste(int regname, bool literally, bool remcr)
       // Locate start of last word in the cmd buffer.
       for (w = ccline.cmdbuff + ccline.cmdpos; w > ccline.cmdbuff;) {
         len = utf_head_off(ccline.cmdbuff, w - 1) + 1;
-        if (!vim_iswordc(utf_ptr2char(w - len))) {
+        if (!vim_iswordc(utf_ptr2char((char *)w - len))) {
           break;
         }
         w -= len;
@@ -4025,10 +4025,10 @@ char_u *ExpandOne(expand_T *xp, char_u *str, char_u *orig, int options, int mode
     size_t len = 0;
 
     for (size_t mb_len; xp->xp_files[0][len]; len += mb_len) {
-      mb_len = (size_t)utfc_ptr2len((char_u *)&xp->xp_files[0][len]);
-      int c0 = utf_ptr2char((char_u *)&xp->xp_files[0][len]);
+      mb_len = (size_t)utfc_ptr2len(&xp->xp_files[0][len]);
+      int c0 = utf_ptr2char(&xp->xp_files[0][len]);
       for (i = 1; i < xp->xp_numfiles; i++) {
-        int ci = utf_ptr2char((char_u *)&xp->xp_files[i][len]);
+        int ci = utf_ptr2char(&xp->xp_files[i][len]);
 
         if (p_fic && (xp->xp_context == EXPAND_DIRECTORIES
                       || xp->xp_context == EXPAND_FILES
diff --git a/src/nvim/file_search.c b/src/nvim/file_search.c
index 1113459feb..6a3acef91d 100644
--- a/src/nvim/file_search.c
+++ b/src/nvim/file_search.c
@@ -1111,8 +1111,8 @@ static bool ff_wc_equal(char_u *s1, char_u *s2)
   }
 
   for (i = 0, j = 0; s1[i] != NUL && s2[j] != NUL;) {
-    c1 = utf_ptr2char(s1 + i);
-    c2 = utf_ptr2char(s2 + j);
+    c1 = utf_ptr2char((char *)s1 + i);
+    c2 = utf_ptr2char((char *)s2 + j);
 
     if ((p_fic ? mb_tolower(c1) != mb_tolower(c2) : c1 != c2)
         && (prev1 != '*' || prev2 != '*')) {
@@ -1121,8 +1121,8 @@ static bool ff_wc_equal(char_u *s1, char_u *s2)
     prev2 = prev1;
     prev1 = c1;
 
-    i += utfc_ptr2len(s1 + i);
-    j += utfc_ptr2len(s2 + j);
+    i += utfc_ptr2len((char *)s1 + i);
+    j += utfc_ptr2len((char *)s2 + j);
   }
   return s1[i] == s2[j];
 }
diff --git a/src/nvim/fileio.c b/src/nvim/fileio.c
index 24052d4951..ad0440e0b3 100644
--- a/src/nvim/fileio.c
+++ b/src/nvim/fileio.c
@@ -1377,7 +1377,7 @@ retry:
             } else {
               len = utf_head_off(ptr, p);
               p -= len;
-              u8c = utf_ptr2char(p);
+              u8c = utf_ptr2char((char *)p);
               if (len == 0) {
                 // Not a valid UTF-8 character, retry with
                 // another fenc when possible, otherwise just
@@ -3982,7 +3982,7 @@ static int buf_write_bytes(struct bw_info *ip)
             break;
           }
           if (n > 1) {
-            c = utf_ptr2char(ip->bw_rest);
+            c = utf_ptr2char((char *)ip->bw_rest);
           } else {
             c = ip->bw_rest[0];
           }
@@ -4010,7 +4010,7 @@ static int buf_write_bytes(struct bw_info *ip)
             break;
           }
           if (n > 1) {
-            c = utf_ptr2char(buf + wlen);
+            c = utf_ptr2char((char *)buf + wlen);
           } else {
             c = buf[wlen];
           }
diff --git a/src/nvim/fold.c b/src/nvim/fold.c
index af7288e103..56f3f4893d 100644
--- a/src/nvim/fold.c
+++ b/src/nvim/fold.c
@@ -1798,10 +1798,10 @@ char_u *get_foldtext(win_T *wp, linenr_T lnum, linenr_T lnume, foldinfo_T foldin
       // Replace unprintable characters, if there are any.  But
       // replace a TAB with a space.
       for (p = text; *p != NUL; p++) {
-        int len = utfc_ptr2len(p);
+        int len = utfc_ptr2len((char *)p);
 
         if (len > 1) {
-          if (!vim_isprintc(utf_ptr2char(p))) {
+          if (!vim_isprintc(utf_ptr2char((char *)p))) {
             break;
           }
           p += len - 1;
diff --git a/src/nvim/getchar.c b/src/nvim/getchar.c
index 4bf7543f5f..5f2a4a281b 100644
--- a/src/nvim/getchar.c
+++ b/src/nvim/getchar.c
@@ -700,7 +700,7 @@ static int read_redo(bool init, bool old_redo)
     buf[i] = (char_u)c;
     if (i == n - 1) {         // last byte of a character
       if (n != 1) {
-        c = utf_ptr2char(buf);
+        c = utf_ptr2char((char *)buf);
       }
       break;
     }
@@ -1624,7 +1624,7 @@ int vgetc(void)
           }
         }
         no_mapping--;
-        c = utf_ptr2char(buf);
+        c = utf_ptr2char((char *)buf);
       }
 
       if (vgetc_char == 0) {
@@ -1935,7 +1935,7 @@ static int handle_mapping(int *keylenp, bool *timedout, int *mapdepth)
         char_u *p1 = mp->m_keys;
         char_u *p2 = (char_u *)mb_unescape((const char **)&p1);
 
-        if (p2 != NULL && MB_BYTE2LEN(tb_c1) > utfc_ptr2len(p2)) {
+        if (p2 != NULL && MB_BYTE2LEN(tb_c1) > utfc_ptr2len((char *)p2)) {
           mlen = 0;
         }
 
@@ -2450,7 +2450,7 @@ static int vgetorpeek(bool advance)
                     curwin->w_wcol = vcol;
                   }
                   vcol += lbr_chartabsize(ptr, ptr + col, vcol);
-                  col += utfc_ptr2len(ptr + col);
+                  col += utfc_ptr2len((char *)ptr + col);
                 }
                 curwin->w_wrow = curwin->w_cline_row
                                  + curwin->w_wcol / curwin->w_width_inner;
@@ -2471,7 +2471,7 @@ static int vgetorpeek(bool advance)
               // of a double-wide character.
               ptr = get_cursor_line_ptr();
               col -= utf_head_off(ptr, ptr + col);
-              if (utf_ptr2cells(ptr + col) > 1) {
+              if (utf_ptr2cells((char *)ptr + col) > 1) {
                 curwin->w_wcol--;
               }
             }
@@ -3137,7 +3137,7 @@ int buf_do_map(int maptype, MapArguments *args, int mode, bool is_abbrev, buf_T
 
         const int first = vim_iswordp(lhs);
         int last = first;
-        p = lhs + utfc_ptr2len(lhs);
+        p = lhs + utfc_ptr2len((char *)lhs);
         n = 1;
         while (p < lhs + len) {
           n++;                                  // nr of (multi-byte) chars
@@ -3145,7 +3145,7 @@ int buf_do_map(int maptype, MapArguments *args, int mode, bool is_abbrev, buf_T
           if (same == -1 && last != first) {
             same = n - 1;                       // count of same char type
           }
-          p += utfc_ptr2len(p);
+          p += utfc_ptr2len((char *)p);
         }
         if (last && n > 2 && same >= 0 && same < n - 1) {
           retval = 1;
@@ -3543,14 +3543,14 @@ static void validate_maphash(void)
 /*
  * Get the mapping mode from the command name.
  */
-int get_map_mode(char_u **cmdp, bool forceit)
+int get_map_mode(char **cmdp, bool forceit)
 {
-  char_u *p;
+  char *p;
   int modec;
   int mode;
 
   p = *cmdp;
-  modec = *p++;
+  modec = (uint8_t)(*p++);
   if (modec == 'i') {
     mode = INSERT;                              // :imap
   } else if (modec == 'l') {
@@ -3597,7 +3597,7 @@ void map_clear_mode(char_u *cmdp, char_u *arg, int forceit, int abbr)
     return;
   }
 
-  mode = get_map_mode(&cmdp, forceit);
+  mode = get_map_mode((char **)&cmdp, forceit);
   map_clear_int(curbuf, mode,
                 local,
                 abbr);
@@ -3894,7 +3894,7 @@ char_u *set_context_in_map_cmd(expand_T *xp, char_u *cmd, char_u *arg, bool forc
     xp->xp_context = EXPAND_NOTHING;
   } else {
     if (isunmap) {
-      expand_mapmodes = get_map_mode(&cmd, forceit || isabbrev);
+      expand_mapmodes = get_map_mode((char **)&cmd, forceit || isabbrev);
     } else {
       expand_mapmodes = INSERT + CMDLINE;
       if (!isabbrev) {
@@ -4117,7 +4117,7 @@ bool check_abbr(int c, char_u *ptr, int col, int mincol)
     while (p > ptr + mincol) {
       p = mb_prevptr(ptr, p);
       if (ascii_isspace(*p) || (!vim_abbr && is_id != vim_iswordp(p))) {
-        p += utfc_ptr2len(p);
+        p += utfc_ptr2len((char *)p);
         break;
       }
       ++clen;
@@ -4310,8 +4310,8 @@ char_u *vim_strsave_escape_ks(char_u *p)
     } else {
       // Add character, possibly multi-byte to destination, escaping
       // K_SPECIAL. Be careful, it can be an illegal byte!
-      d = add_char2buf(utf_ptr2char(s), d);
-      s += utf_ptr2len(s);
+      d = add_char2buf(utf_ptr2char((char *)s), d);
+      s += utf_ptr2len((char *)s);
     }
   }
   *d = NUL;
diff --git a/src/nvim/hardcopy.c b/src/nvim/hardcopy.c
index b2974854c1..1e9c69c390 100644
--- a/src/nvim/hardcopy.c
+++ b/src/nvim/hardcopy.c
@@ -589,7 +589,7 @@ static void prt_header(prt_settings_T *const psettings, const int pagenum, const
   int page_line = 0 - prt_header_height();
   mch_print_start_line(true, page_line);
   for (char_u *p = tbuf; *p != NUL;) {
-    const int l = utfc_ptr2len(p);
+    const int l = utfc_ptr2len((char *)p);
     assert(l >= 0);
     if (mch_print_text_out(p, (size_t)l)) {
       page_line++;
@@ -896,7 +896,7 @@ static colnr_T hardcopy_line(prt_settings_T *psettings, int page_line, prt_pos_T
    * Loop over the columns until the end of the file line or right margin.
    */
   for (col = ppos->column; line[col] != NUL && !need_break; col += outputlen) {
-    if ((outputlen = utfc_ptr2len(line + col)) < 1) {
+    if ((outputlen = utfc_ptr2len((char *)line + col)) < 1) {
       outputlen = 1;
     }
     // syntax highlighting stuff.
@@ -949,7 +949,7 @@ static colnr_T hardcopy_line(prt_settings_T *psettings, int page_line, prt_pos_T
       need_break = 1;
     } else {
       need_break = mch_print_text_out(line + col, (size_t)outputlen);
-      print_pos += utf_ptr2cells(line + col);
+      print_pos += utf_ptr2cells((char *)line + col);
     }
   }
 
@@ -3002,7 +3002,7 @@ int mch_print_text_out(char_u *const textp, size_t len)
     }
   }
   if (prt_out_mbyte) {
-    const bool half_width = (utf_ptr2cells(p) == 1);
+    const bool half_width = (utf_ptr2cells((char *)p) == 1);
     if (half_width) {
       char_width /= 2;
     }
diff --git a/src/nvim/input.c b/src/nvim/input.c
index 6827dcae87..0dfd564e1f 100644
--- a/src/nvim/input.c
+++ b/src/nvim/input.c
@@ -144,7 +144,7 @@ int get_keystroke(MultiQueue *events)
       continue;
     }
     buf[len >= buflen ? buflen - 1 : len] = NUL;
-    n = utf_ptr2char(buf);
+    n = utf_ptr2char((char *)buf);
     break;
   }
   xfree(buf);
diff --git a/src/nvim/keymap.c b/src/nvim/keymap.c
index 7541837782..3c30389e0b 100644
--- a/src/nvim/keymap.c
+++ b/src/nvim/keymap.c
@@ -719,10 +719,10 @@ int find_special_key(const char_u **const srcp, const size_t src_len, int *const
           // Special case for a double-quoted string
           off = l = 2;
         } else {
-          l = utfc_ptr2len(last_dash + 1);
+          l = utfc_ptr2len((char *)last_dash + 1);
         }
         if (modifiers != 0 && last_dash[l + 1] == '>') {
-          key = utf_ptr2char(last_dash + off);
+          key = utf_ptr2char((char *)last_dash + off);
         } else {
           key = get_special_key_code(last_dash + off);
           if (!(flags & FSK_KEEP_X_KEY)) {
diff --git a/src/nvim/macros.h b/src/nvim/macros.h
index 0af7483154..69ff8c18e4 100644
--- a/src/nvim/macros.h
+++ b/src/nvim/macros.h
@@ -95,10 +95,10 @@
 
 // MB_PTR_ADV(): advance a pointer to the next character, taking care of
 // multi-byte characters if needed. Skip over composing chars.
-#define MB_PTR_ADV(p)      (p += utfc_ptr2len((char_u *)p))
+#define MB_PTR_ADV(p)      (p += utfc_ptr2len((char *)p))
 
 // Advance multi-byte pointer, do not skip over composing chars.
-#define MB_CPTR_ADV(p)     (p += utf_ptr2len(p))
+#define MB_CPTR_ADV(p)     (p += utf_ptr2len((char *)p))
 
 // MB_PTR_BACK(): backup a pointer to the previous character, taking care of
 // multi-byte characters if needed. Only use with "p" > "s" !
diff --git a/src/nvim/mark.c b/src/nvim/mark.c
index 0a9b1b26ef..02ae148396 100644
--- a/src/nvim/mark.c
+++ b/src/nvim/mark.c
@@ -1579,7 +1579,7 @@ void mark_mb_adjustpos(buf_T *buf, pos_T *lp)
     // double-wide character.
     if (lp->coladd == 1
         && p[lp->col] != TAB
-        && vim_isprintc(utf_ptr2char(p + lp->col))
+        && vim_isprintc(utf_ptr2char((char *)p + lp->col))
         && ptr2cells(p + lp->col) > 1) {
       lp->coladd = 0;
     }
diff --git a/src/nvim/match.c b/src/nvim/match.c
index e6f34c5876..808b761df0 100644
--- a/src/nvim/match.c
+++ b/src/nvim/match.c
@@ -93,7 +93,7 @@ static int match_add(win_T *wp, const char *const grp, const char *const pat, in
   m->match.rmm_maxcol = 0;
   m->conceal_char = 0;
   if (conceal_char != NULL) {
-    m->conceal_char = utf_ptr2char((const char_u *)conceal_char);
+    m->conceal_char = utf_ptr2char(conceal_char);
   }
 
   // Set up position matches
@@ -447,7 +447,7 @@ static void next_search_hl(win_T *win, match_T *search_hl, match_T *shl, linenr_
         shl->lnum = 0;
         break;
       }
-      matchcol += utfc_ptr2len(ml);
+      matchcol += utfc_ptr2len((char *)ml);
     } else {
       matchcol = shl->rm.endpos[0].col;
     }
@@ -634,7 +634,7 @@ bool prepare_search_hl_line(win_T *wp, linenr_T lnum, colnr_T mincol, char_u **l
       // Highlight one character for an empty match.
       if (shl->startcol == shl->endcol) {
         if ((*line)[shl->endcol] != NUL) {
-          shl->endcol += utfc_ptr2len(*line + shl->endcol);
+          shl->endcol += utfc_ptr2len((char *)(*line) + shl->endcol);
         } else {
           shl->endcol++;
         }
@@ -688,7 +688,7 @@ int update_search_hl(win_T *wp, linenr_T lnum, colnr_T col, char_u **line, match
       if (shl->startcol != MAXCOL
           && col >= shl->startcol
           && col < shl->endcol) {
-        int next_col = col + utfc_ptr2len(*line + col);
+        int next_col = col + utfc_ptr2len((char *)(*line) + col);
 
         if (shl->endcol < next_col) {
           shl->endcol = next_col;
@@ -736,7 +736,7 @@ int update_search_hl(win_T *wp, linenr_T lnum, colnr_T col, char_u **line, match
 
           if (shl->startcol == shl->endcol) {
             // highlight empty match, try again after it
-            shl->endcol += utfc_ptr2len(*line + shl->endcol);
+            shl->endcol += utfc_ptr2len((char *)(*line) + shl->endcol);
           }
 
           // Loop to check if the match starts at the
diff --git a/src/nvim/mbyte.c b/src/nvim/mbyte.c
index 6dbbb17da9..5f1114fa42 100644
--- a/src/nvim/mbyte.c
+++ b/src/nvim/mbyte.c
@@ -430,7 +430,7 @@ int mb_get_class_tab(const char_u *p, const uint64_t *const chartab)
     }
     return 1;
   }
-  return utf_class_tab(utf_ptr2char(p), chartab);
+  return utf_class_tab(utf_ptr2char((char *)p), chartab);
 }
 
 /*
@@ -512,12 +512,12 @@ int utf_char2cells(int c)
 
 /// Return the number of display cells character at "*p" occupies.
 /// This doesn't take care of unprintable characters, use ptr2cells() for that.
-int utf_ptr2cells(const char_u *p)
+int utf_ptr2cells(const char *p)
 {
   int c;
 
   // Need to convert to a character number.
-  if (*p >= 0x80) {
+  if ((uint8_t)(*p) >= 0x80) {
     c = utf_ptr2char(p);
     // An illegal byte is displayed as <xx>.
     if (utf_ptr2len(p) == 1 || c == NUL) {
@@ -543,9 +543,9 @@ int utf_ptr2cells_len(const char_u *p, int size)
     if (utf_ptr2len_len(p, size) < utf8len_tab[*p]) {
       return 1;        // truncated
     }
-    c = utf_ptr2char(p);
+    c = utf_ptr2char((char *)p);
     // An illegal byte is displayed as <xx>.
-    if (utf_ptr2len(p) == 1 || c == NUL) {
+    if (utf_ptr2len((char *)p) == 1 || c == NUL) {
       return 4;
     }
     // If the char is ASCII it must be an overlong sequence.
@@ -566,8 +566,8 @@ size_t mb_string2cells(const char *str)
 {
   size_t clen = 0;
 
-  for (const char_u *p = (char_u *)str; *p != NUL; p += utfc_ptr2len(p)) {
-    clen += utf_ptr2cells(p);
+  for (const char_u *p = (char_u *)str; *p != NUL; p += utfc_ptr2len((char *)p)) {
+    clen += utf_ptr2cells((char *)p);
   }
 
   return clen;
@@ -586,7 +586,7 @@ size_t mb_string2cells_len(const char_u *str, size_t size)
 
   for (const char_u *p = str; *p != NUL && p < str + size;
        p += utfc_ptr2len_len(p, size + (p - str))) {
-    clen += utf_ptr2cells(p);
+    clen += utf_ptr2cells((char *)p);
   }
 
   return clen;
@@ -602,9 +602,10 @@ size_t mb_string2cells_len(const char_u *str, size_t size)
 /// @param[in]  p  String to convert.
 ///
 /// @return Unicode codepoint or byte value.
-int utf_ptr2char(const char_u *const p)
+int utf_ptr2char(const char *const p_in)
   FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
 {
+  uint8_t *p = (uint8_t *)p_in;
   if (p[0] < 0x80) {  // Be quick for ASCII.
     return p[0];
   }
@@ -679,7 +680,7 @@ static int utf_safe_read_char_adv(const char_u **s, size_t *n)
     // We have a multibyte sequence and it isn't truncated by buffer
     // limits so utf_ptr2char() is safe to use. Or the first byte is
     // illegal (k=0), and it's also safe to use utf_ptr2char().
-    c = utf_ptr2char(*s);
+    c = utf_ptr2char((char *)(*s));
 
     // On failure, utf_ptr2char() returns the first byte, so here we
     // check equality with the first byte. The only non-ASCII character
@@ -706,8 +707,8 @@ int mb_ptr2char_adv(const char_u **const pp)
 {
   int c;
 
-  c = utf_ptr2char(*pp);
-  *pp += utfc_ptr2len(*pp);
+  c = utf_ptr2char((char *)(*pp));
+  *pp += utfc_ptr2len((char *)(*pp));
   return c;
 }
 
@@ -719,8 +720,8 @@ int mb_cptr2char_adv(const char_u **pp)
 {
   int c;
 
-  c = utf_ptr2char(*pp);
-  *pp += utf_ptr2len(*pp);
+  c = utf_ptr2char((char *)(*pp));
+  *pp += utf_ptr2len((char *)(*pp));
   return c;
 }
 
@@ -733,14 +734,14 @@ bool utf_composinglike(const char_u *p1, const char_u *p2)
 {
   int c2;
 
-  c2 = utf_ptr2char(p2);
+  c2 = utf_ptr2char((char *)p2);
   if (utf_iscomposing(c2)) {
     return true;
   }
   if (!arabic_maycombine(c2)) {
     return false;
   }
-  return arabic_combine(utf_ptr2char(p1), c2);
+  return arabic_combine(utf_ptr2char((char *)p1), c2);
 }
 
 /// Convert a UTF-8 string to a wide character
@@ -758,21 +759,21 @@ int utfc_ptr2char(const char_u *p, int *pcc)
   int cc;
   int i = 0;
 
-  c = utf_ptr2char(p);
-  len = utf_ptr2len(p);
+  c = utf_ptr2char((char *)p);
+  len = utf_ptr2len((char *)p);
 
   // Only accept a composing char when the first char isn't illegal.
   if ((len > 1 || *p < 0x80)
       && p[len] >= 0x80
       && utf_composinglike(p, p + len)) {
-    cc = utf_ptr2char(p + len);
+    cc = utf_ptr2char((char *)p + len);
     for (;;) {
       pcc[i++] = cc;
       if (i == MAX_MCO) {
         break;
       }
-      len += utf_ptr2len(p + len);
-      if (p[len] < 0x80 || !utf_iscomposing(cc = utf_ptr2char(p + len))) {
+      len += utf_ptr2len((char *)p + len);
+      if (p[len] < 0x80 || !utf_iscomposing(cc = utf_ptr2char((char *)p + len))) {
         break;
       }
     }
@@ -800,14 +801,14 @@ int utfc_ptr2char_len(const char_u *p, int *pcc, int maxlen)
   int len = utf_ptr2len_len(p, maxlen);
   // Is it safe to use utf_ptr2char()?
   bool safe = len > 1 && len <= maxlen;
-  int c = safe ? utf_ptr2char(p) : *p;
+  int c = safe ? utf_ptr2char((char *)p) : *p;
 
   // Only accept a composing char when the first char isn't illegal.
   if ((safe || c < 0x80) && len < maxlen && p[len] >= 0x80) {
     for (; i < MAX_MCO; i++) {
       int len_cc = utf_ptr2len_len(p + len, maxlen - len);
       safe = len_cc > 1 && len_cc <= maxlen - len;
-      if (!safe || (pcc[i] = utf_ptr2char(p + len)) < 0x80
+      if (!safe || (pcc[i] = utf_ptr2char((char *)p + len)) < 0x80
           || !(i == 0 ? utf_composinglike(p, p + len) : utf_iscomposing(pcc[i]))) {
         break;
       }
@@ -830,9 +831,10 @@ int utfc_ptr2char_len(const char_u *p, int *pcc, int maxlen)
 ///
 /// @return Sequence length, 0 for empty string and 1 for non-UTF-8 byte
 ///         sequence.
-int utf_ptr2len(const char_u *const p)
+int utf_ptr2len(const char *const p_in)
   FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_NONNULL_ALL
 {
+  uint8_t *p = (uint8_t *)p_in;
   if (*p == NUL) {
     return 0;
   }
@@ -889,10 +891,11 @@ int utf_ptr2len_len(const char_u *p, int size)
 /// Return the number of bytes occupied by a UTF-8 character in a string
 ///
 /// This includes following composing characters.
-int utfc_ptr2len(const char_u *const p)
+int utfc_ptr2len(const char *const p_in)
   FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_NONNULL_ALL
 {
-  uint8_t b0 = (uint8_t)(*p);
+  uint8_t *p = (uint8_t *)p_in;
+  uint8_t b0 = *p;
 
   if (b0 == NUL) {
     return 0;
@@ -902,7 +905,7 @@ int utfc_ptr2len(const char_u *const p)
   }
 
   // Skip over first UTF-8 char, stopping at a NUL byte.
-  int len = utf_ptr2len(p);
+  int len = utf_ptr2len((char *)p);
 
   // Check for illegal byte.
   if (len == 1 && b0 >= 0x80) {
@@ -919,7 +922,7 @@ int utfc_ptr2len(const char_u *const p)
 
     // Skip over composing char.
     prevlen = len;
-    len += utf_ptr2len(p + len);
+    len += utf_ptr2len((char *)p + len);
   }
 }
 
@@ -1510,7 +1513,7 @@ void mb_utflen(const char_u *s, size_t len, size_t *codepoints, size_t *codeunit
     clen = utf_ptr2len_len(s + i, len - i);
     // NB: gets the byte value of invalid sequence bytes.
     // we only care whether the char fits in the BMP or not
-    int c = (clen > 1) ? utf_ptr2char(s + i) : s[i];
+    int c = (clen > 1) ? utf_ptr2char((char *)s + i) : s[i];
     count++;
     if (c > 0xFFFF) {
       extra++;
@@ -1532,7 +1535,7 @@ ssize_t mb_utf_index_to_bytes(const char_u *s, size_t len, size_t index, bool us
     clen = utf_ptr2len_len(s + i, len - i);
     // NB: gets the byte value of invalid sequence bytes.
     // we only care whether the char fits in the BMP or not
-    int c = (clen > 1) ? utf_ptr2char(s + i) : s[i];
+    int c = (clen > 1) ? utf_ptr2char((char *)s + i) : s[i];
     count++;
     if (use_utf16_units && c > 0xFFFF) {
       count++;
@@ -1590,7 +1593,7 @@ void show_utf8(void)
   // Get the byte length of the char under the cursor, including composing
   // characters.
   line = get_cursor_pos_ptr();
-  len = utfc_ptr2len(line);
+  len = utfc_ptr2len((char *)line);
   if (len == 0) {
     msg("NUL");
     return;
@@ -1604,7 +1607,7 @@ void show_utf8(void)
         STRCPY(IObuff + rlen, "+ ");
         rlen += 2;
       }
-      clen = utf_ptr2len(line + i);
+      clen = utf_ptr2len((char *)line + i);
     }
     sprintf((char *)IObuff + rlen, "%02x ",
             (line[i] == NL) ? NUL : line[i]);          // NUL is stored as NL
@@ -1654,7 +1657,7 @@ int utf_head_off(const char_u *base, const char_u *p)
       break;
     }
 
-    c = utf_ptr2char(q);
+    c = utf_ptr2char((char *)q);
     if (utf_iscomposing(c)) {
       continue;
     }
@@ -1667,7 +1670,7 @@ int utf_head_off(const char_u *base, const char_u *p)
       while (j > base && (*j & 0xc0) == 0x80) {
         --j;
       }
-      if (arabic_combine(utf_ptr2char(j), c)) {
+      if (arabic_combine(utf_ptr2char((char *)j), c)) {
         continue;
       }
     }
@@ -1823,7 +1826,7 @@ bool utf_allow_break(int cc, int ncc)
 /// @param[in,out]  tp  Destination to copy to.
 void mb_copy_char(const char_u **const fp, char_u **const tp)
 {
-  const size_t l = (size_t)utfc_ptr2len(*fp);
+  const size_t l = (size_t)utfc_ptr2len((char *)(*fp));
 
   memmove(*tp, *fp, l);
   *tp += l;
@@ -1955,9 +1958,9 @@ void utf_find_illegal(void)
     while (*p != NUL) {
       // Illegal means that there are not enough trail bytes (checked by
       // utf_ptr2len()) or too many of them (overlong sequence).
-      len = utf_ptr2len(p);
+      len = utf_ptr2len((char *)p);
       if (*p >= 0x80 && (len == 1
-                         || utf_char2len(utf_ptr2char(p)) != len)) {
+                         || utf_char2len(utf_ptr2char((char *)p)) != len)) {
         if (vimconv.vc_type == CONV_NONE) {
           curwin->w_cursor.col += (colnr_T)(p - get_cursor_pos_ptr());
         } else {
@@ -1965,7 +1968,7 @@ void utf_find_illegal(void)
 
           len = (int)(p - tofree);
           for (p = get_cursor_pos_ptr(); *p != NUL && len-- > 0; p += l) {
-            l = utf_ptr2len(p);
+            l = utf_ptr2len((char *)p);
             curwin->w_cursor.col += l;
           }
         }
@@ -2027,7 +2030,7 @@ void mb_check_adjust_col(void *win_)
     // Reset `coladd` when the cursor would be on the right half of a
     // double-wide character.
     if (win->w_cursor.coladd == 1 && p[win->w_cursor.col] != TAB
-        && vim_isprintc(utf_ptr2char(p + win->w_cursor.col))
+        && vim_isprintc(utf_ptr2char((char *)p + win->w_cursor.col))
         && ptr2cells(p + win->w_cursor.col) > 1) {
       win->w_cursor.coladd = 0;
     }
@@ -2057,7 +2060,7 @@ int mb_charlen(const char_u *str)
   }
 
   for (count = 0; *p != NUL; count++) {
-    p += utfc_ptr2len(p);
+    p += utfc_ptr2len((char *)p);
   }
 
   return count;
@@ -2070,7 +2073,7 @@ int mb_charlen_len(const char_u *str, int len)
   int count;
 
   for (count = 0; *p != NUL && p < str + len; count++) {
-    p += utfc_ptr2len(p);
+    p += utfc_ptr2len((char *)p);
   }
 
   return count;
@@ -2110,7 +2113,7 @@ const char *mb_unescape(const char **const pp)
 
     // Return a multi-byte character if it's found.  An illegal sequence
     // will result in a 1 here.
-    if (utf_ptr2len((const char_u *)buf) > 1) {
+    if (utf_ptr2len(buf) > 1) {
       *pp = (const char *)str + str_idx + 1;
       return buf;
     }
@@ -2400,7 +2403,7 @@ static char_u *iconv_string(const vimconv_T *const vcp, char_u *str, size_t slen
       // conversion from 'encoding' to something else.  In other
       // situations we don't know what to skip anyway.
       *to++ = '?';
-      if (utf_ptr2cells((char_u *)from) > 1) {
+      if (utf_ptr2cells(from) > 1) {
         *to++ = '?';
       }
       l = utfc_ptr2len_len((const char_u *)from, (int)fromlen);
@@ -2616,7 +2619,7 @@ char_u *string_convert_ext(const vimconv_T *const vcp, char_u *ptr, size_t *lenp
         }
         *d++ = ptr[i];
       } else {
-        c = utf_ptr2char(ptr + i);
+        c = utf_ptr2char((char *)ptr + i);
         if (vcp->vc_type == CONV_TO_LATIN9) {
           switch (c) {
           case 0x20ac:
diff --git a/src/nvim/memline.c b/src/nvim/memline.c
index eec0b2fafc..081045ab18 100644
--- a/src/nvim/memline.c
+++ b/src/nvim/memline.c
@@ -1823,7 +1823,7 @@ int gchar_pos(pos_T *pos)
   if (pos->col == MAXCOL) {
     return NUL;
   }
-  return utf_ptr2char(ml_get_pos(pos));
+  return utf_ptr2char((char *)ml_get_pos(pos));
 }
 
 /// @param will_change  true mark the buffer dirty (chars in the line will be changed)
@@ -4206,7 +4206,7 @@ int inc(pos_T *lp)
   if (lp->col != MAXCOL) {
     const char_u *const p = ml_get_pos(lp);
     if (*p != NUL) {  // still within line, move to next char (may be NUL)
-      const int l = utfc_ptr2len(p);
+      const int l = utfc_ptr2len((char *)p);
 
       lp->col += l;
       return ((p[l] != NUL) ? 0 : 2);
diff --git a/src/nvim/message.c b/src/nvim/message.c
index 57433ac988..2cd3f8b63d 100644
--- a/src/nvim/message.c
+++ b/src/nvim/message.c
@@ -408,7 +408,7 @@ void trunc_string(char_u *s, char_u *buf, int room_in, int buflen)
     }
     len += n;
     buf[e] = s[e];
-    for (n = utfc_ptr2len(s + e); --n > 0;) {
+    for (n = utfc_ptr2len((char *)s + e); --n > 0;) {
       if (++e == buflen) {
         break;
       }
@@ -421,7 +421,7 @@ void trunc_string(char_u *s, char_u *buf, int room_in, int buflen)
   for (;;) {
     do {
       half = half - utf_head_off(s, s + half - 1) - 1;
-    } while (half > 0 && utf_iscomposing(utf_ptr2char(s + half)));
+    } while (half > 0 && utf_iscomposing(utf_ptr2char((char *)s + half)));
     n = ptr2cells(s + half);
     if (len + n > room || half == 0) {
       break;
@@ -882,8 +882,8 @@ char_u *msg_may_trunc(bool force, char_u *s)
     }
     int n;
     for (n = 0; size >= room;) {
-      size -= utf_ptr2cells(s + n);
-      n += utfc_ptr2len(s + n);
+      size -= utf_ptr2cells((char *)s + n);
+      n += utfc_ptr2len((char *)s + n);
     }
     n--;
     s += n;
@@ -1480,7 +1480,7 @@ char_u *msg_outtrans_one(char_u *p, int attr)
 {
   int l;
 
-  if ((l = utfc_ptr2len(p)) > 1) {
+  if ((l = utfc_ptr2len((char *)p)) > 1) {
     msg_outtrans_len_attr(p, l, attr);
     return p + l;
   }
@@ -1509,7 +1509,7 @@ int msg_outtrans_len_attr(const char_u *msgstr, int len, int attr)
 
   // If the string starts with a composing character first draw a space on
   // which the composing char can be drawn.
-  if (utf_iscomposing(utf_ptr2char(msgstr))) {
+  if (utf_iscomposing(utf_ptr2char((char *)msgstr))) {
     msg_puts_attr(" ", attr);
   }
 
@@ -1521,10 +1521,10 @@ int msg_outtrans_len_attr(const char_u *msgstr, int len, int attr)
     // Don't include composing chars after the end.
     mb_l = utfc_ptr2len_len((char_u *)str, len + 1);
     if (mb_l > 1) {
-      c = utf_ptr2char((char_u *)str);
+      c = utf_ptr2char(str);
       if (vim_isprintc(c)) {
         // Printable multi-byte char: count the cells.
-        retval += utf_ptr2cells((char_u *)str);
+        retval += utf_ptr2cells(str);
       } else {
         // Unprintable multi-byte char: print the printable chars so
         // far and the translation of the unprintable char.
@@ -1624,7 +1624,7 @@ int msg_outtrans_special(const char_u *strstart, bool from, int maxlen)
     }
     // Highlight special keys
     msg_puts_attr(text, (len > 1
-                         && utfc_ptr2len((char_u *)text) <= 1
+                         && utfc_ptr2len(text) <= 1
                          ? attr : 0));
     retval += len;
   }
@@ -1705,7 +1705,7 @@ const char *str2special(const char **const sp, const bool replace_spaces, const
     const char *p = mb_unescape(sp);
 
     if (p == NULL) {
-      const int len = utf_ptr2len((const char_u *)str);
+      const int len = utf_ptr2len(str);
       // Check for an illegal byte.
       if (MB_BYTE2LEN((uint8_t)(*str)) > len) {
         transchar_nonprint(curbuf, (char_u *)buf, c);
@@ -1717,7 +1717,7 @@ const char *str2special(const char **const sp, const bool replace_spaces, const
     }
     // Since 'special' is true the multi-byte character 'c' will be
     // processed by get_special_key_name().
-    c = utf_ptr2char((const char_u *)p);
+    c = utf_ptr2char(p);
   } else {
     *sp = str + 1;
   }
@@ -1813,16 +1813,16 @@ void msg_prt_line(char_u *s, int list)
         assert(p_extra != NULL);
         c = *p_extra++;
       }
-    } else if ((l = utfc_ptr2len(s)) > 1) {
-      col += utf_ptr2cells(s);
+    } else if ((l = utfc_ptr2len((char *)s)) > 1) {
+      col += utf_ptr2cells((char *)s);
       char buf[MB_MAXBYTES + 1];
       if (l >= MB_MAXBYTES) {
         xstrlcpy(buf, "?", sizeof(buf));
       } else if (curwin->w_p_lcs_chars.nbsp != NUL && list
-                 && (utf_ptr2char(s) == 160
-                     || utf_ptr2char(s) == 0x202f)) {
+                 && (utf_ptr2char((char *)s) == 160
+                     || utf_ptr2char((char *)s) == 0x202f)) {
         utf_char2bytes(curwin->w_p_lcs_chars.nbsp, (char_u *)buf);
-        buf[utfc_ptr2len((char_u *)buf)] = NUL;
+        buf[utfc_ptr2len(buf)] = NUL;
       } else {
         memmove(buf, s, (size_t)l);
         buf[l] = NUL;
@@ -1913,7 +1913,7 @@ static char_u *screen_puts_mbyte(char_u *s, int l, int attr)
   attr = hl_combine_attr(HL_ATTR(HLF_MSG), attr);
 
   msg_didout = true;            // remember that line is not empty
-  cw = utf_ptr2cells(s);
+  cw = utf_ptr2cells((char *)s);
   if (cw > 1
       && (cmdmsg_rl ? msg_col <= 1 : msg_col == Columns - 1)) {
     // Doesn't fit, print a highlighted '>' to fill it up.
@@ -2116,12 +2116,12 @@ static void msg_puts_display(const char_u *str, int maxlen, int attr, int recurs
         && (*s == '\n' || (cmdmsg_rl
                            ? (msg_col <= 1
                               || (*s == TAB && msg_col <= 7)
-                              || (utf_ptr2cells(s) > 1
+                              || (utf_ptr2cells((char *)s) > 1
                                   && msg_col <= 2))
                            : ((*s != '\r' && msg_col + t_col >= Columns - 1)
                               || (*s == TAB
                                   && msg_col + t_col >= ((Columns - 1) & ~7))
-                              || (utf_ptr2cells(s) > 1
+                              || (utf_ptr2cells((char *)s) > 1
                                   && msg_col + t_col >= Columns - 2))))) {
       // The screen is scrolled up when at the last row (some terminals
       // scroll automatically, some don't.  To avoid problems we scroll
@@ -2151,7 +2151,7 @@ static void msg_puts_display(const char_u *str, int maxlen, int attr, int recurs
           // Avoid including composing chars after the end.
           l = utfc_ptr2len_len(s, (int)((str + maxlen) - s));
         } else {
-          l = utfc_ptr2len(s);
+          l = utfc_ptr2len((char *)s);
         }
         s = screen_puts_mbyte((char_u *)s, l, attr);
         did_last_char = true;
@@ -2206,7 +2206,7 @@ static void msg_puts_display(const char_u *str, int maxlen, int attr, int recurs
 
     wrap = *s == '\n'
            || msg_col + t_col >= Columns
-           || (utf_ptr2cells(s) > 1
+           || (utf_ptr2cells((char *)s) > 1
                && msg_col + t_col >= Columns - 1)
     ;
     if (t_col > 0 && (wrap || *s == '\r' || *s == '\b'
@@ -2243,12 +2243,12 @@ static void msg_puts_display(const char_u *str, int maxlen, int attr, int recurs
     } else if (*s == BELL) {  // beep (from ":sh")
       vim_beep(BO_SH);
     } else if (*s >= 0x20) {  // printable char
-      cw = utf_ptr2cells(s);
+      cw = utf_ptr2cells((char *)s);
       if (maxlen >= 0) {
         // avoid including composing chars after the end
         l = utfc_ptr2len_len(s, (int)((str + maxlen) - s));
       } else {
-        l = utfc_ptr2len(s);
+        l = utfc_ptr2len((char *)s);
       }
       // When drawing from right to left or when a double-wide character
       // doesn't fit, draw a single character here.  Otherwise collect
@@ -2609,7 +2609,7 @@ static void t_puts(int *t_col, const char_u *t_s, const char_u *s, int attr)
   *t_col = 0;
   // If the string starts with a composing character don't increment the
   // column position for it.
-  if (utf_iscomposing(utf_ptr2char(t_s))) {
+  if (utf_iscomposing(utf_ptr2char((char *)t_s))) {
     msg_col--;
   }
   if (msg_col >= Columns) {
@@ -2645,7 +2645,7 @@ static void msg_puts_printf(const char *str, const ptrdiff_t maxlen)
   }
 
   while ((maxlen < 0 || s - str < maxlen) && *s != NUL) {
-    int len = utf_ptr2len((const char_u *)s);
+    int len = utf_ptr2len(s);
     if (!(silent_mode && p_verbose == 0)) {
       // NL --> CR NL translation (for Unix, not for "--version")
       p = &buf[0];
@@ -2661,7 +2661,7 @@ static void msg_puts_printf(const char *str, const ptrdiff_t maxlen)
       }
     }
 
-    int cw = utf_char2cells(utf_ptr2char((const char_u *)s));
+    int cw = utf_char2cells(utf_ptr2char(s));
     // primitive way to compute the current column
     if (cmdmsg_rl) {
       if (*s == '\r' || *s == '\n') {
@@ -3473,10 +3473,10 @@ int do_dialog(int type, char_u *title, char_u *message, char_u *buttons, int dfl
       c = mb_tolower(c);
       retval = 1;
       for (i = 0; hotkeys[i]; i++) {
-        if (utf_ptr2char(hotkeys + i) == c) {
+        if (utf_ptr2char((char *)hotkeys + i) == c) {
           break;
         }
-        i += utfc_ptr2len(hotkeys + i) - 1;
+        i += utfc_ptr2len((char *)hotkeys + i) - 1;
         retval++;
       }
       if (hotkeys[i]) {
@@ -3508,10 +3508,10 @@ static int copy_char(const char_u *from, char_u *to, bool lowercase)
   FUNC_ATTR_NONNULL_ALL
 {
   if (lowercase) {
-    int c = mb_tolower(utf_ptr2char(from));
+    int c = mb_tolower(utf_ptr2char((char *)from));
     return utf_char2bytes(c, to);
   }
-  int len = utfc_ptr2len(from);
+  int len = utfc_ptr2len((char *)from);
   memmove(to, from, (size_t)len);
   return len;
 }
diff --git a/src/nvim/mouse.c b/src/nvim/mouse.c
index 4495473074..8038ba2cad 100644
--- a/src/nvim/mouse.c
+++ b/src/nvim/mouse.c
@@ -702,7 +702,7 @@ static int mouse_adjust_click(win_T *wp, int row, int col)
     vcol = 0;
     while (vcol < offset && *ptr != NUL) {
       vcol += win_chartabsize(curwin, ptr, vcol);
-      ptr += utfc_ptr2len(ptr);
+      ptr += utfc_ptr2len((char *)ptr);
     }
 
     ptr_row_offset = ptr;
@@ -713,7 +713,7 @@ static int mouse_adjust_click(win_T *wp, int row, int col)
   ptr_end = ptr_row_offset;
   while (vcol < col && *ptr_end != NUL) {
     vcol += win_chartabsize(curwin, ptr_end, vcol);
-    ptr_end += utfc_ptr2len(ptr_end);
+    ptr_end += utfc_ptr2len((char *)ptr_end);
   }
 
   int matchid;
@@ -723,8 +723,8 @@ static int mouse_adjust_click(win_T *wp, int row, int col)
 
   vcol = offset;
 
-#define INCR() nudge++; ptr_end += utfc_ptr2len(ptr_end)
-#define DECR() nudge--; ptr_end -= utfc_ptr2len(ptr_end)
+#define INCR() nudge++; ptr_end += utfc_ptr2len((char *)ptr_end)
+#define DECR() nudge--; ptr_end -= utfc_ptr2len((char *)ptr_end)
 
   while (ptr < ptr_end && *ptr != NUL) {
     cwidth = win_chartabsize(curwin, ptr, vcol);
@@ -755,7 +755,7 @@ static int mouse_adjust_click(win_T *wp, int row, int col)
 
         while (prev_matchid == matchid && *ptr != NUL) {
           INCR();
-          ptr += utfc_ptr2len(ptr);
+          ptr += utfc_ptr2len((char *)ptr);
           matchid = syn_get_concealed_id(wp, lnum, (colnr_T)(ptr - line));
         }
 
@@ -763,7 +763,7 @@ static int mouse_adjust_click(win_T *wp, int row, int col)
       }
     }
 
-    ptr += utfc_ptr2len(ptr);
+    ptr += utfc_ptr2len((char *)ptr);
   }
 
   return col + nudge;
@@ -798,8 +798,8 @@ int mouse_check_fold(void)
     // Remember the character under the mouse, might be one of foldclose or
     // foldopen fillchars in the fold column.
     if (gp->chars != NULL) {
-      mouse_char = utf_ptr2char(gp->chars[gp->line_offset[row]
-                                          + (unsigned)col]);
+      mouse_char = utf_ptr2char((char *)gp->chars[gp->line_offset[row]
+                                                  + (unsigned)col]);
     }
 
     // Check for position outside of the fold column.
diff --git a/src/nvim/normal.c b/src/nvim/normal.c
index 81c95ec77f..9c8c27c9bb 100644
--- a/src/nvim/normal.c
+++ b/src/nvim/normal.c
@@ -2094,7 +2094,7 @@ bool do_mouse(oparg_T *oap, int c, int dir, long count, bool fixindent)
           find_start_of_word(&VIsual);
           if (*p_sel == 'e' && *get_cursor_pos_ptr() != NUL) {
             curwin->w_cursor.col +=
-              utfc_ptr2len(get_cursor_pos_ptr());
+              utfc_ptr2len((char *)get_cursor_pos_ptr());
           }
           find_end_of_word(&curwin->w_cursor);
         }
@@ -2157,7 +2157,7 @@ static void find_end_of_word(pos_T *pos)
   }
   cclass = get_mouse_class(line + pos->col);
   while (line[pos->col] != NUL) {
-    col = pos->col + utfc_ptr2len(line + pos->col);
+    col = pos->col + utfc_ptr2len((char *)line + pos->col);
     if (get_mouse_class(line + col) != cclass) {
       if (*p_sel == 'e') {
         pos->col = col;
@@ -2340,7 +2340,7 @@ size_t find_ident_at_pos(win_T *wp, linenr_T lnum, colnr_T startcol, char_u **te
       if (this_class != 0 && (i == 1 || this_class != 1)) {
         break;
       }
-      col += utfc_ptr2len(ptr + col);
+      col += utfc_ptr2len((char *)ptr + col);
     }
 
     // When starting on a ']' count it, so that we include the '['.
@@ -2408,7 +2408,7 @@ size_t find_ident_at_pos(win_T *wp, linenr_T lnum, colnr_T startcol, char_u **te
              || ((find_type & FIND_EVAL)
                  && col <= (int)startcol
                  && find_is_eval_item(ptr + col, &col, &bn, FORWARD)))) {
-    col += utfc_ptr2len(ptr + col);
+    col += utfc_ptr2len((char *)ptr + col);
   }
 
   assert(col >= 0);
@@ -2585,7 +2585,7 @@ void clear_showcmd(void)
         e = ml_get_pos(&VIsual);
       }
       while ((*p_sel != 'e') ? s <= e : s < e) {
-        l = utfc_ptr2len(s);
+        l = utfc_ptr2len((char *)s);
         if (l == 0) {
           bytes++;
           chars++;
@@ -3262,7 +3262,7 @@ static bool nv_screengo(oparg_T *oap, int dir, long dist)
       virtcol -= vim_strsize(get_showbreak_value(curwin));
     }
 
-    int c = utf_ptr2char(get_cursor_pos_ptr());
+    int c = utf_ptr2char((char *)get_cursor_pos_ptr());
     if (dir == FORWARD && virtcol < curwin->w_curswant
         && (curwin->w_curswant <= (colnr_T)width1)
         && !vim_isprintc(c) && c > 255) {
@@ -4239,7 +4239,7 @@ static void nv_ident(cmdarg_T *cap)
       }
       // When current byte is a part of multibyte character, copy all
       // bytes of that character.
-      const size_t len = (size_t)(utfc_ptr2len(ptr) - 1);
+      const size_t len = (size_t)(utfc_ptr2len((char *)ptr) - 1);
       for (size_t i = 0; i < len && n > 0; i++, n--) {
         *p++ = *ptr++;
       }
@@ -4308,7 +4308,7 @@ bool get_visual_text(cmdarg_T *cap, char_u **pp, size_t *lenp)
     }
     if (*lenp > 0) {
       // Correct the length to include all bytes of the last character.
-      *lenp += (size_t)(utfc_ptr2len(*pp + (*lenp - 1)) - 1);
+      *lenp += (size_t)(utfc_ptr2len((char *)(*pp) + (*lenp - 1)) - 1);
     }
   }
   reset_VIsual_and_resel();
@@ -4470,7 +4470,7 @@ static void nv_right(cmdarg_T *cap)
       if (virtual_active()) {
         oneright();
       } else {
-        curwin->w_cursor.col += utfc_ptr2len(get_cursor_pos_ptr());
+        curwin->w_cursor.col += utfc_ptr2len((char *)get_cursor_pos_ptr());
       }
     }
   }
@@ -4521,7 +4521,7 @@ static void nv_left(cmdarg_T *cap)
           char_u *cp = get_cursor_pos_ptr();
 
           if (*cp != NUL) {
-            curwin->w_cursor.col += utfc_ptr2len(cp);
+            curwin->w_cursor.col += utfc_ptr2len((char *)cp);
           }
           cap->retval |= CA_NO_ADJ_OP_END;
         }
diff --git a/src/nvim/ops.c b/src/nvim/ops.c
index f7a3201568..d9844b4e99 100644
--- a/src/nvim/ops.c
+++ b/src/nvim/ops.c
@@ -381,7 +381,7 @@ static void shift_block(oparg_T *oap, int amount)
     colnr_T ws_vcol = bd.start_vcol - bd.pre_whitesp;
     char_u *old_textstart = bd.textstart;
     if (bd.startspaces) {
-      if (utfc_ptr2len(bd.textstart) == 1) {
+      if (utfc_ptr2len((char *)bd.textstart) == 1) {
         bd.textstart++;
       } else {
         ws_vcol = 0;
@@ -2034,7 +2034,7 @@ static int op_replace(oparg_T *oap, int c)
       n = gchar_cursor();
       if (n != NUL) {
         int new_byte_len = utf_char2len(c);
-        int old_byte_len = utfc_ptr2len(get_cursor_pos_ptr());
+        int old_byte_len = utfc_ptr2len((char *)get_cursor_pos_ptr());
 
         if (new_byte_len > 1 || old_byte_len > 1) {
           // This is slow, but it handles replacing a single-byte
@@ -2195,7 +2195,7 @@ static int swapchars(int op_type, pos_T *pos, int length)
   int did_change = 0;
 
   for (int todo = length; todo > 0; todo--) {
-    const int len = utfc_ptr2len(ml_get_pos(pos));
+    const int len = utfc_ptr2len((char *)ml_get_pos(pos));
 
     // we're counting bytes, not characters
     if (len > 0) {
@@ -2256,7 +2256,7 @@ bool swapchar(int op_type, pos_T *pos)
 
       curwin->w_cursor = *pos;
       // don't use del_char(), it also removes composing chars
-      del_bytes(utf_ptr2len(get_cursor_pos_ptr()), false, false);
+      del_bytes(utf_ptr2len((char *)get_cursor_pos_ptr()), false, false);
       ins_char(nc);
       curwin->w_cursor = sp;
     } else {
@@ -3076,7 +3076,7 @@ void do_put(int regname, yankreg_T *reg, int dir, long count, int flags)
         bool one_past_line = (*cursor_pos == NUL);
         bool eol = false;
         if (!one_past_line) {
-          eol = (*(cursor_pos + utfc_ptr2len(cursor_pos)) == NUL);
+          eol = (*(cursor_pos + utfc_ptr2len((char *)cursor_pos)) == NUL);
         }
 
         bool ve_allows = (cur_ve_flags == VE_ALL || cur_ve_flags == VE_ONEMORE);
@@ -3291,7 +3291,7 @@ void do_put(int regname, yankreg_T *reg, int dir, long count, int flags)
       }
 
       // move to start of next multi-byte character
-      curwin->w_cursor.col += utfc_ptr2len(get_cursor_pos_ptr());
+      curwin->w_cursor.col += utfc_ptr2len((char *)get_cursor_pos_ptr());
       col++;
     } else {
       getvcol(curwin, &curwin->w_cursor, &col, NULL, &endcol2);
@@ -3466,7 +3466,7 @@ void do_put(int regname, yankreg_T *reg, int dir, long count, int flags)
       // if type is kMTCharWise, FORWARD is the same as BACKWARD on the next
       // char
       if (dir == FORWARD && gchar_cursor() != NUL) {
-        int bytelen = utfc_ptr2len(get_cursor_pos_ptr());
+        int bytelen = utfc_ptr2len((char *)get_cursor_pos_ptr());
 
         // put it on the next of the multi-byte character.
         col += bytelen;
@@ -3898,7 +3898,7 @@ void ex_display(exarg_T *eap)
             n -= 2;
           }
           for (p = yb->y_array[j]; *p != NUL && (n -= ptr2cells(p)) >= 0; p++) {  // -V1019
-            clen = utfc_ptr2len(p);
+            clen = utfc_ptr2len((char *)p);
             msg_outtrans_len(p, clen);
             p += clen - 1;
           }
@@ -3976,7 +3976,7 @@ static void dis_msg(const char_u *p, bool skip_esc)
   while (*p != NUL
          && !(*p == ESC && skip_esc && *(p + 1) == NUL)
          && (n -= ptr2cells(p)) >= 0) {
-    if ((l = utfc_ptr2len(p)) > 1) {
+    if ((l = utfc_ptr2len((char *)p)) > 1) {
       msg_outtrans_len(p, l);
       p += l;
     } else {
@@ -4120,11 +4120,11 @@ int do_join(size_t count, int insert_space, int save_undo, int use_formatoptions
           && sumsize != 0
           && endcurr1 != TAB
           && (!has_format_option(FO_MBYTE_JOIN)
-              || (utf_ptr2char(curr) < 0x100 && endcurr1 < 0x100))
+              || (utf_ptr2char((char *)curr) < 0x100 && endcurr1 < 0x100))
           && (!has_format_option(FO_MBYTE_JOIN2)
-              || (utf_ptr2char(curr) < 0x100 && !utf_eat_space(endcurr1))
+              || (utf_ptr2char((char *)curr) < 0x100 && !utf_eat_space(endcurr1))
               || (endcurr1 < 0x100
-                  && !utf_eat_space(utf_ptr2char(curr))))) {
+                  && !utf_eat_space(utf_ptr2char((char *)curr))))) {
         // don't add a space if the line is ending in a space
         if (endcurr1 == ' ') {
           endcurr1 = endcurr2;
@@ -4151,10 +4151,10 @@ int do_join(size_t count, int insert_space, int save_undo, int use_formatoptions
     if (insert_space && currsize > 0) {
       cend = curr + currsize;
       MB_PTR_BACK(curr, cend);
-      endcurr1 = utf_ptr2char(cend);
+      endcurr1 = utf_ptr2char((char *)cend);
       if (cend > curr) {
         MB_PTR_BACK(curr, cend);
-        endcurr2 = utf_ptr2char(cend);
+        endcurr2 = utf_ptr2char((char *)cend);
       }
     }
     line_breakcheck();
@@ -5117,7 +5117,7 @@ int do_addsub(int op_type, pos_T *pos, int length, linenr_T Prenum1)
   if (visual) {
     while (ptr[col] != NUL && length > 0 && !ascii_isdigit(ptr[col])
            && !(do_alpha && ASCII_ISALPHA(ptr[col]))) {
-      int mb_len = utfc_ptr2len(ptr + col);
+      int mb_len = utfc_ptr2len((char *)ptr + col);
 
       col += mb_len;
       length -= mb_len;
@@ -5842,7 +5842,7 @@ static varnumber_T line_count_info(char_u *line, varnumber_T *wc, varnumber_T *c
       is_word = 1;
     }
     chars++;
-    i += utfc_ptr2len(line + i);
+    i += utfc_ptr2len((char *)line + i);
   }
 
   if (is_word) {
@@ -6592,7 +6592,7 @@ void do_pending_operator(cmdarg_T *cap, int old_col, bool gui_yank)
 
     // Include the trailing byte of a multi-byte char.
     if (oap->inclusive) {
-      const int l = utfc_ptr2len(ml_get_pos(&oap->end));
+      const int l = utfc_ptr2len((char *)ml_get_pos(&oap->end));
       if (l > 1) {
         oap->end.col += l - 1;
       }
diff --git a/src/nvim/option.c b/src/nvim/option.c
index 9be55b91b4..aac05eba0b 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -1502,7 +1502,7 @@ int do_set(char_u *arg, int opt_flags)
                     ) {
                   arg++;                        // remove backslash
                 }
-                i = utfc_ptr2len(arg);
+                i = utfc_ptr2len((char *)arg);
                 if (i > 1) {
                   // copy multibyte char
                   memmove(s, arg, (size_t)i);
@@ -2664,13 +2664,13 @@ ambw_end:
       int x2 = -1;
       int x3 = -1;
 
-      p += utfc_ptr2len(p);
+      p += utfc_ptr2len((char *)p);
       if (*p != NUL) {
         x2 = *p++;
       }
       if (*p != NUL) {
-        x3 = utf_ptr2char(p);
-        p += utfc_ptr2len(p);
+        x3 = utf_ptr2char((char *)p);
+        p += utfc_ptr2len((char *)p);
       }
       if (x2 != ':' || x3 == -1 || (*p != NUL && *p != ',')) {
         errmsg = e_invarg;
@@ -3526,7 +3526,7 @@ static int get_encoded_char_adv(char_u **p)
   }
 
   // TODO(bfredl): use schar_T representation and utfc_ptr2len
-  int clen = utf_ptr2len(s);
+  int clen = utf_ptr2len((char *)s);
   int c = mb_cptr2char_adv((const char_u **)p);
   if (clen == 1 && c > 127) {  // Invalid UTF-8 byte
     return 0;
@@ -7140,7 +7140,7 @@ static void langmap_set(void)
       if (p[0] == '\\' && p[1] != NUL) {
         p++;
       }
-      from = utf_ptr2char(p);
+      from = utf_ptr2char((char *)p);
       to = NUL;
       if (p2 == NULL) {
         MB_PTR_ADV(p);
@@ -7148,14 +7148,14 @@ static void langmap_set(void)
           if (p[0] == '\\') {
             p++;
           }
-          to = utf_ptr2char(p);
+          to = utf_ptr2char((char *)p);
         }
       } else {
         if (p2[0] != ',') {
           if (p2[0] == '\\') {
             p2++;
           }
-          to = utf_ptr2char(p2);
+          to = utf_ptr2char((char *)p2);
         }
       }
       if (to == NUL) {
diff --git a/src/nvim/path.c b/src/nvim/path.c
index 4cbe6ebcf5..9e3aad5aae 100644
--- a/src/nvim/path.c
+++ b/src/nvim/path.c
@@ -299,7 +299,7 @@ void shorten_dir_len(char_u *str, int trim_len)
           skip = true;
         }
       }
-      int l = utfc_ptr2len(s);
+      int l = utfc_ptr2len((char *)s);
       while (--l > 0) {
         *d++ = *++s;
       }
@@ -642,12 +642,12 @@ static size_t do_path_expand(garray_T *gap, const char_u *path, size_t wildoff,
     } else if (path_end >= path + wildoff
                && (vim_strchr((char_u *)"*?[{~$", *path_end) != NULL
 #ifndef WIN32
-                   || (!p_fic && (flags & EW_ICASE) && mb_isalpha(utf_ptr2char(path_end)))
+                   || (!p_fic && (flags & EW_ICASE) && mb_isalpha(utf_ptr2char((char *)path_end)))
 #endif
                    )) {
       e = p;
     }
-    len = (size_t)(utfc_ptr2len(path_end));
+    len = (size_t)(utfc_ptr2len((char *)path_end));
     memcpy(p, path_end, len);
     p += len;
     path_end += len;
@@ -1980,8 +1980,8 @@ int pathcmp(const char *p, const char *q, int maxlen)
   const char *s = NULL;
 
   for (i = 0, j = 0; maxlen < 0 || (i < maxlen && j < maxlen);) {
-    c1 = utf_ptr2char((char_u *)p + i);
-    c2 = utf_ptr2char((char_u *)q + j);
+    c1 = utf_ptr2char(p + i);
+    c2 = utf_ptr2char(q + j);
 
     // End of "p": check if "q" also ends or just has a slash.
     if (c1 == NUL) {
@@ -2016,15 +2016,15 @@ int pathcmp(const char *p, const char *q, int maxlen)
                    : c1 - c2;  // no match
     }
 
-    i += utfc_ptr2len((char_u *)p + i);
-    j += utfc_ptr2len((char_u *)q + j);
+    i += utfc_ptr2len(p + i);
+    j += utfc_ptr2len(q + j);
   }
   if (s == NULL) {  // "i" or "j" ran into "maxlen"
     return 0;
   }
 
-  c1 = utf_ptr2char((char_u *)s + i);
-  c2 = utf_ptr2char((char_u *)s + i + utfc_ptr2len((char_u *)s + i));
+  c1 = utf_ptr2char(s + i);
+  c2 = utf_ptr2char(s + i + utfc_ptr2len(s + i));
   // ignore a trailing slash, but not "//" or ":/"
   if (c2 == NUL
       && i > 0
diff --git a/src/nvim/popupmnu.c b/src/nvim/popupmnu.c
index aff0ea94f7..78b3ceaacf 100644
--- a/src/nvim/popupmnu.c
+++ b/src/nvim/popupmnu.c
@@ -521,7 +521,7 @@ void pum_redraw(void)
 
               if (size > pum_width) {
                 do {
-                  size -= utf_ptr2cells(rt);
+                  size -= utf_ptr2cells((char *)rt);
                   MB_PTR_ADV(rt);
                 } while (size > pum_width);
 
diff --git a/src/nvim/regexp.c b/src/nvim/regexp.c
index cc960b0dc7..6a4a15d7f8 100644
--- a/src/nvim/regexp.c
+++ b/src/nvim/regexp.c
@@ -392,9 +392,9 @@ static int get_equi_class(char_u **pp)
   char_u      *p = *pp;
 
   if (p[1] == '=' && p[2] != NUL) {
-    l = utfc_ptr2len(p + 2);
+    l = utfc_ptr2len((char *)p + 2);
     if (p[l + 2] == '=' && p[l + 3] == ']') {
-      c = utf_ptr2char(p + 2);
+      c = utf_ptr2char((char *)p + 2);
       *pp += l + 4;
       return c;
     }
@@ -416,9 +416,9 @@ static int get_coll_element(char_u **pp)
   char_u      *p = *pp;
 
   if (p[0] != NUL && p[1] == '.' && p[2] != NUL) {
-    l = utfc_ptr2len(p + 2);
+    l = utfc_ptr2len((char *)p + 2);
     if (p[l + 2] == '.' && p[l + 3] == ']') {
-      c = utf_ptr2char(p + 2);
+      c = utf_ptr2char((char *)p + 2);
       *pp += l + 4;
       return c;
     }
@@ -449,7 +449,7 @@ static char_u *skip_anyof(char_u *p)
     p++;
   }
   while (*p != NUL && *p != ']') {
-    if ((l = utfc_ptr2len(p)) > 1) {
+    if ((l = utfc_ptr2len((char *)p)) > 1) {
       p += l;
     } else if (*p == '-')  {
       p++;
@@ -719,13 +719,13 @@ static int peekchr(void)
        * Next character can never be (made) magic?
        * Then backslashing it won't do anything.
        */
-      curchr = utf_ptr2char(regparse + 1);
+      curchr = utf_ptr2char((char *)regparse + 1);
     }
     break;
   }
 
   default:
-    curchr = utf_ptr2char(regparse);
+    curchr = utf_ptr2char((char *)regparse);
   }
 
   return curchr;
@@ -744,7 +744,7 @@ static void skipchr(void)
   }
   if (regparse[prevchr_len] != NUL) {
     // Exclude composing chars that utfc_ptr2len does include.
-    prevchr_len += utf_ptr2len(regparse + prevchr_len);
+    prevchr_len += utf_ptr2len((char *)regparse + prevchr_len);
   }
   regparse += prevchr_len;
   prev_at_start = at_start;
@@ -1463,8 +1463,8 @@ static inline char_u *cstrchr(const char_u *const s, const int c)
   // expected to be highly optimized.
   if (c > 0x80) {
     const int folded_c = utf_fold(c);
-    for (const char_u *p = s; *p != NUL; p += utfc_ptr2len(p)) {
-      if (utf_fold(utf_ptr2char(p)) == folded_c) {
+    for (const char_u *p = s; *p != NUL; p += utfc_ptr2len((char *)p)) {
+      if (utf_fold(utf_ptr2char((char *)p)) == folded_c) {
         return (char_u *)p;
       }
     }
@@ -1571,7 +1571,7 @@ char_u *regtilde(char_u *source, int magic, bool preview)
       if (*p == '\\' && p[1]) {         // skip escaped characters
         p++;
       }
-      p += utfc_ptr2len(p) - 1;
+      p += utfc_ptr2len((char *)p) - 1;
     }
   }
 
@@ -1914,7 +1914,7 @@ static int vim_regsub_both(char_u *source, typval_T *expr, char_u *dest,
             c = *src++;
           }
         } else {
-          c = utf_ptr2char(src - 1);
+          c = utf_ptr2char((char *)src - 1);
         }
         // Write to buffer, if copy is set.
         if (func_one != NULL) {
@@ -1926,13 +1926,13 @@ static int vim_regsub_both(char_u *source, typval_T *expr, char_u *dest,
           cc = c;
         }
 
-        int totlen = utfc_ptr2len(src - 1);
+        int totlen = utfc_ptr2len((char *)src - 1);
 
         if (copy) {
           utf_char2bytes(cc, dst);
         }
         dst += utf_char2len(cc) - 1;
-        int clen = utf_ptr2len(src - 1);
+        int clen = utf_ptr2len((char *)src - 1);
 
         // If the character length is shorter than "totlen", there
         // are composing characters; copy them as-is.
@@ -2005,7 +2005,7 @@ static int vim_regsub_both(char_u *source, typval_T *expr, char_u *dest,
                 }
                 dst += 2;
               } else {
-                c = utf_ptr2char(s);
+                c = utf_ptr2char((char *)s);
 
                 if (func_one != (fptr_T)NULL) {
                   // Turbo C complains without the typecast
@@ -2022,7 +2022,7 @@ static int vim_regsub_both(char_u *source, typval_T *expr, char_u *dest,
 
                   // Copy composing characters separately, one
                   // at a time.
-                  l = utf_ptr2len(s) - 1;
+                  l = utf_ptr2len((char *)s) - 1;
 
                   s += l;
                   len -= l;
diff --git a/src/nvim/regexp_bt.c b/src/nvim/regexp_bt.c
index 7d0b9a7a77..e8878d61d5 100644
--- a/src/nvim/regexp_bt.c
+++ b/src/nvim/regexp_bt.c
@@ -1895,8 +1895,8 @@ collection:
           } else {
             // produce a multibyte character, including any
             // following composing characters.
-            startc = utf_ptr2char(regparse);
-            int len = utfc_ptr2len(regparse);
+            startc = utf_ptr2char((char *)regparse);
+            int len = utfc_ptr2len((char *)regparse);
             if (utf_char2len(startc) != len) {
               // composing chars
               startc = -1;
@@ -1953,11 +1953,11 @@ do_multibyte:
 
           // Need to get composing character too.
           for (;; ) {
-            l = utf_ptr2len(regparse);
+            l = utf_ptr2len((char *)regparse);
             if (!utf_composinglike(regparse, regparse + l)) {
               break;
             }
-            regmbc(utf_ptr2char(regparse));
+            regmbc(utf_ptr2char((char *)regparse));
             skipchr();
           }
         }
@@ -2403,7 +2403,7 @@ static regprog_T *bt_regcomp(char_u *expr, int re_flags)
     }
 
     if (OP(scan) == EXACTLY) {
-      r->regstart = utf_ptr2char(OPERAND(scan));
+      r->regstart = utf_ptr2char((char *)OPERAND(scan));
     } else if (OP(scan) == BOW
                || OP(scan) == EOW
                || OP(scan) == NOTHING
@@ -2411,7 +2411,7 @@ static regprog_T *bt_regcomp(char_u *expr, int re_flags)
                || OP(scan) == MCLOSE + 0 || OP(scan) == NCLOSE) {
       char_u *regnext_scan = regnext(scan);
       if (OP(regnext_scan) == EXACTLY) {
-        r->regstart = utf_ptr2char(OPERAND(regnext_scan));
+        r->regstart = utf_ptr2char((char *)OPERAND(regnext_scan));
       }
     }
 
@@ -2614,7 +2614,7 @@ regrepeat(
   case SIDENT:
   case SIDENT + ADD_NL:
     while (count < maxcount) {
-      if (vim_isIDc(utf_ptr2char(scan)) && (testval || !ascii_isdigit(*scan))) {
+      if (vim_isIDc(utf_ptr2char((char *)scan)) && (testval || !ascii_isdigit(*scan))) {
         MB_PTR_ADV(scan);
       } else if (*scan == NUL) {
         if (!REG_MULTI || !WITH_NL(OP(p)) || rex.lnum > rex.reg_maxline
@@ -2671,7 +2671,7 @@ regrepeat(
   case SFNAME:
   case SFNAME + ADD_NL:
     while (count < maxcount) {
-      if (vim_isfilec(utf_ptr2char(scan)) && (testval || !ascii_isdigit(*scan))) {
+      if (vim_isfilec(utf_ptr2char((char *)scan)) && (testval || !ascii_isdigit(*scan))) {
         MB_PTR_ADV(scan);
       } else if (*scan == NUL) {
         if (!REG_MULTI || !WITH_NL(OP(p)) || rex.lnum > rex.reg_maxline
@@ -2709,7 +2709,7 @@ regrepeat(
         if (got_int) {
           break;
         }
-      } else if (vim_isprintc(utf_ptr2char(scan)) == 1
+      } else if (vim_isprintc(utf_ptr2char((char *)scan)) == 1
                  && (testval || !ascii_isdigit(*scan))) {
         MB_PTR_ADV(scan);
       } else if (rex.reg_line_lbr && *scan == '\n' && WITH_NL(OP(p))) {
@@ -2737,7 +2737,7 @@ do_class:
         if (got_int) {
           break;
         }
-      } else if ((l = utfc_ptr2len(scan)) > 1) {
+      } else if ((l = utfc_ptr2len((char *)scan)) > 1) {
         if (testval != 0) {
           break;
         }
@@ -2852,18 +2852,18 @@ do_class:
 
     // Safety check (just in case 'encoding' was changed since
     // compiling the program).
-    if ((len = utfc_ptr2len(opnd)) > 1) {
+    if ((len = utfc_ptr2len((char *)opnd)) > 1) {
       if (rex.reg_ic) {
-        cf = utf_fold(utf_ptr2char(opnd));
+        cf = utf_fold(utf_ptr2char((char *)opnd));
       }
-      while (count < maxcount && utfc_ptr2len(scan) >= len) {
+      while (count < maxcount && utfc_ptr2len((char *)scan) >= len) {
         for (i = 0; i < len; i++) {
           if (opnd[i] != scan[i]) {
             break;
           }
         }
         if (i < len && (!rex.reg_ic
-                        || utf_fold(utf_ptr2char(scan)) != cf)) {
+                        || utf_fold(utf_ptr2char((char *)scan)) != cf)) {
           break;
         }
         scan += len;
@@ -2894,8 +2894,8 @@ do_class:
         }
       } else if (rex.reg_line_lbr && *scan == '\n' && WITH_NL(OP(p))) {
         scan++;
-      } else if ((len = utfc_ptr2len(scan)) > 1) {
-        if ((cstrchr(opnd, utf_ptr2char(scan)) == NULL) == testval) {
+      } else if ((len = utfc_ptr2len((char *)scan)) > 1) {
+        if ((cstrchr(opnd, utf_ptr2char((char *)scan)) == NULL) == testval) {
           break;
         }
         scan += len;
@@ -3106,7 +3106,7 @@ static bool regmatch(
         if (WITH_NL(op)) {
           op -= ADD_NL;
         }
-        c = utf_ptr2char(rex.input);
+        c = utf_ptr2char((char *)rex.input);
         switch (op) {
         case BOL:
           if (rex.input != rex.line) {
@@ -3308,7 +3308,7 @@ static bool regmatch(
           break;
 
         case PRINT:
-          if (!vim_isprintc(utf_ptr2char(rex.input))) {
+          if (!vim_isprintc(utf_ptr2char((char *)rex.input))) {
             status = RA_NOMATCH;
           } else {
             ADVANCE_REGINPUT();
@@ -3316,7 +3316,7 @@ static bool regmatch(
           break;
 
         case SPRINT:
-          if (ascii_isdigit(*rex.input) || !vim_isprintc(utf_ptr2char(rex.input))) {
+          if (ascii_isdigit(*rex.input) || !vim_isprintc(utf_ptr2char((char *)rex.input))) {
             status = RA_NOMATCH;
           } else {
             ADVANCE_REGINPUT();
@@ -3507,25 +3507,25 @@ static bool regmatch(
           const char_u *opnd = OPERAND(scan);
             // Safety check (just in case 'encoding' was changed since
             // compiling the program).
-          if ((len = utfc_ptr2len(opnd)) < 2) {
+          if ((len = utfc_ptr2len((char *)opnd)) < 2) {
             status = RA_NOMATCH;
             break;
           }
-          const int opndc = utf_ptr2char(opnd);
+          const int opndc = utf_ptr2char((char *)opnd);
           if (utf_iscomposing(opndc)) {
               // When only a composing char is given match at any
               // position where that composing char appears.
             status = RA_NOMATCH;
             for (i = 0; rex.input[i] != NUL;
-                 i += utf_ptr2len(rex.input + i)) {
-              const int inpc = utf_ptr2char(rex.input + i);
+                 i += utf_ptr2len((char *)rex.input + i)) {
+              const int inpc = utf_ptr2char((char *)rex.input + i);
               if (!utf_iscomposing(inpc)) {
                 if (i > 0) {
                   break;
                 }
               } else if (opndc == inpc) {
                   // Include all following composing chars.
-                len = i + utfc_ptr2len(rex.input + i);
+                len = i + utfc_ptr2len((char *)rex.input + i);
                 status = RA_MATCH;
                 break;
               }
@@ -3545,7 +3545,7 @@ static bool regmatch(
         case RE_COMPOSING:
         {
             // Skip composing characters.
-          while (utf_iscomposing(utf_ptr2char(rex.input))) {
+          while (utf_iscomposing(utf_ptr2char((char *)rex.input))) {
             MB_CPTR_ADV(rex.input);
           }
         }
@@ -4495,7 +4495,7 @@ static long bt_regexec_both(char_u *line,
 
   // If there is a "must appear" string, look for it.
   if (prog->regmust != NULL) {
-    int c = utf_ptr2char(prog->regmust);
+    int c = utf_ptr2char((char *)prog->regmust);
     s = line + col;
 
     // This is used very often, esp. for ":global".  Use two versions of
@@ -4526,7 +4526,7 @@ static long bt_regexec_both(char_u *line,
 
   // Simplest case: Anchored match need be tried only once.
   if (prog->reganch) {
-    int c = utf_ptr2char(rex.line + col);
+    int c = utf_ptr2char((char *)rex.line + col);
     if (prog->regstart == NUL
         || prog->regstart == c
         || (rex.reg_ic
@@ -4570,7 +4570,7 @@ static long bt_regexec_both(char_u *line,
       if (rex.line[col] == NUL) {
         break;
       }
-      col += utfc_ptr2len(rex.line + col);
+      col += utfc_ptr2len((char *)rex.line + col);
       // Check for timeout once in a twenty times to avoid overhead.
       if (tm != NULL && ++tm_count == 20) {
         tm_count = 0;
diff --git a/src/nvim/regexp_nfa.c b/src/nvim/regexp_nfa.c
index a8d6e9c40b..0a6d513a35 100644
--- a/src/nvim/regexp_nfa.c
+++ b/src/nvim/regexp_nfa.c
@@ -1465,7 +1465,7 @@ static int nfa_regatom(void)
       return FAIL;
     }
     for (lp = reg_prev_sub; *lp != NUL; MB_CPTR_ADV(lp)) {
-      EMIT(utf_ptr2char(lp));
+      EMIT(utf_ptr2char((char *)lp));
       if (lp != reg_prev_sub) {
         EMIT(NFA_CONCAT);
       }
@@ -1902,7 +1902,7 @@ collection:
 
         // Normal printable char
         if (startc == -1) {
-          startc = utf_ptr2char(regparse);
+          startc = utf_ptr2char((char *)regparse);
         }
 
         /* Previous char was '-', so this char is end of range. */
@@ -2007,7 +2007,7 @@ collection:
 
 nfa_do_multibyte:
     // plen is length of current char with composing chars
-    if (utf_char2len(c) != (plen = utfc_ptr2len(old_regparse))
+    if (utf_char2len(c) != (plen = utfc_ptr2len((char *)old_regparse))
         || utf_iscomposing(c)) {
       int i = 0;
 
@@ -2025,7 +2025,7 @@ nfa_do_multibyte:
           EMIT(NFA_CONCAT);
         if ((i += utf_char2len(c)) >= plen)
           break;
-        c = utf_ptr2char(old_regparse + i);
+        c = utf_ptr2char((char *)old_regparse + i);
       }
       EMIT(NFA_COMPOSING);
       regparse = old_regparse + plen;
@@ -5167,17 +5167,17 @@ static long find_match_text(colnr_T startcol, int regstart, char_u *match_text)
 #define PTR2LEN(x) utf_ptr2len(x)
 
   colnr_T col = startcol;
-  int regstart_len = PTR2LEN(rex.line + startcol);
+  int regstart_len = PTR2LEN((char *)rex.line + startcol);
 
   for (;;) {
     bool match = true;
     char_u *s1 = match_text;
     char_u *s2 = rex.line + col + regstart_len;  // skip regstart
     while (*s1) {
-      int c1_len = PTR2LEN(s1);
-      int c1 = utf_ptr2char(s1);
-      int c2_len = PTR2LEN(s2);
-      int c2 = utf_ptr2char(s2);
+      int c1_len = PTR2LEN((char *)s1);
+      int c1 = utf_ptr2char((char *)s1);
+      int c2_len = PTR2LEN((char *)s2);
+      int c2 = utf_ptr2char((char *)s2);
 
       if ((c1 != c2 && (!rex.reg_ic || utf_fold(c1) != utf_fold(c2)))
           || c1_len != c2_len) {
@@ -5189,7 +5189,7 @@ static long find_match_text(colnr_T startcol, int regstart, char_u *match_text)
     }
     if (match
         // check that no composing char follows
-        && !utf_iscomposing(utf_ptr2char(s2))) {
+        && !utf_iscomposing(utf_ptr2char((char *)s2))) {
       cleanup_subexpr();
       if (REG_MULTI) {
         rex.reg_startpos[0].lnum = rex.lnum;
@@ -5343,8 +5343,8 @@ static int nfa_regmatch(nfa_regprog_T *prog, nfa_state_T *start,
    * Run for each character.
    */
   for (;; ) {
-    int curc = utf_ptr2char(rex.input);
-    int clen = utfc_ptr2len(rex.input);
+    int curc = utf_ptr2char((char *)rex.input);
+    int clen = utfc_ptr2len((char *)rex.input);
     if (curc == NUL) {
       clen = 0;
       go_to_nextline = false;
@@ -5822,7 +5822,7 @@ static int nfa_regmatch(nfa_regprog_T *prog, nfa_state_T *start,
           // We don't care about the order of composing characters.
           // Get them into cchars[] first.
           while (len < clen) {
-            mc = utf_ptr2char(rex.input + len);
+            mc = utf_ptr2char((char *)rex.input + len);
             cchars[ccount++] = mc;
             len += utf_char2len(mc);
             if (ccount == MAX_MCO) {
@@ -5987,12 +5987,12 @@ static int nfa_regmatch(nfa_regprog_T *prog, nfa_state_T *start,
         break;
 
       case NFA_PRINT:           //  \p
-        result = vim_isprintc(utf_ptr2char(rex.input));
+        result = vim_isprintc(utf_ptr2char((char *)rex.input));
         ADD_STATE_IF_MATCH(t->state);
         break;
 
       case NFA_SPRINT:          //  \P
-        result = !ascii_isdigit(curc) && vim_isprintc(utf_ptr2char(rex.input));
+        result = !ascii_isdigit(curc) && vim_isprintc(utf_ptr2char((char *)rex.input));
         ADD_STATE_IF_MATCH(t->state);
         break;
 
@@ -6346,7 +6346,7 @@ static int nfa_regmatch(nfa_regprog_T *prog, nfa_state_T *start,
         // If rex.reg_icombine is not set only skip over the character
         // itself.  When it is set skip over composing characters.
         if (result && !rex.reg_icombine) {
-          clen = utf_ptr2len(rex.input);
+          clen = utf_ptr2len((char *)rex.input);
         }
 
         ADD_STATE_IF_MATCH(t->state);
@@ -6494,7 +6494,7 @@ static int nfa_regmatch(nfa_regprog_T *prog, nfa_state_T *start,
           } else {
             // Checking if the required start character matches is
             // cheaper than adding a state that won't match.
-            const int c = utf_ptr2char(rex.input + clen);
+            const int c = utf_ptr2char((char *)rex.input + clen);
             if (c != prog->regstart
                 && (!rex.reg_ic
                     || utf_fold(c) != utf_fold(prog->regstart))) {
diff --git a/src/nvim/screen.c b/src/nvim/screen.c
index 07207b70d1..f3e627cc65 100644
--- a/src/nvim/screen.c
+++ b/src/nvim/screen.c
@@ -1858,8 +1858,8 @@ static int compute_foldcolumn(win_T *wp, int col)
 static int line_putchar(buf_T *buf, LineState *s, schar_T *dest, int maxcells, bool rl, int vcol)
 {
   const char_u *p = (char_u *)s->p;
-  int cells = utf_ptr2cells(p);
-  int c_len = utfc_ptr2len(p);
+  int cells = utf_ptr2cells((char *)p);
+  int c_len = utfc_ptr2len((char *)p);
   int u8c, u8cc[MAX_MCO];
   if (cells > maxcells) {
     return -1;
@@ -1886,7 +1886,7 @@ static int line_putchar(buf_T *buf, LineState *s, schar_T *dest, int maxcells, b
       if (rl) {
         pc = s->prev_c;
         pc1 = s->prev_c1;
-        nc = utf_ptr2char(p + c_len);
+        nc = utf_ptr2char((char *)p + c_len);
         s->prev_c1 = u8cc[0];
       } else {
         pc = utfc_ptr2char(p + c_len, pcc);
@@ -2534,7 +2534,7 @@ static int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool noc
       ptr = prev_ptr;
       // If the character fits on the screen, don't need to skip it.
       // Except for a TAB.
-      if (utf_ptr2cells(ptr) >= c || *ptr == TAB) {
+      if (utf_ptr2cells((char *)ptr) >= c || *ptr == TAB) {
         n_skip = v - vcol;
       }
     }
@@ -2958,7 +2958,7 @@ static int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool noc
       // handle Visual or match highlighting in this line
       if (vcol == fromcol
           || (vcol + 1 == fromcol && n_extra == 0
-              && utf_ptr2cells(ptr) > 1)
+              && utf_ptr2cells((char *)ptr) > 1)
           || ((int)vcol_prev == fromcol_prev
               && vcol_prev < vcol               // not at margin
               && vcol < tocol)) {
@@ -3058,7 +3058,7 @@ static int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool noc
         mb_c = c;
         // If the UTF-8 character is more than one byte:
         // Decode it into "mb_c".
-        mb_l = utfc_ptr2len(p_extra);
+        mb_l = utfc_ptr2len((char *)p_extra);
         mb_utf8 = false;
         if (mb_l > n_extra) {
           mb_l = 1;
@@ -3111,7 +3111,7 @@ static int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool noc
       mb_c = c;
       // If the UTF-8 character is more than one byte: Decode it
       // into "mb_c".
-      mb_l = utfc_ptr2len(ptr);
+      mb_l = utfc_ptr2len((char *)ptr);
       mb_utf8 = false;
       if (mb_l > 1) {
         mb_c = utfc_ptr2char(ptr, u8cc);
@@ -3169,7 +3169,7 @@ static int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool noc
         if (wp->w_p_rl) {
           pc = prev_c;
           pc1 = prev_c1;
-          nc = utf_ptr2char(ptr + mb_l);
+          nc = utf_ptr2char((char *)ptr + mb_l);
           prev_c1 = u8cc[0];
         } else {
           pc = utfc_ptr2char(ptr + mb_l, pcc);
@@ -5072,7 +5072,7 @@ void win_redr_status_matches(expand_T *xp, int num_matches, char_u **matches, in
       for (; *s != NUL; ++s) {
         s += skip_status_match_char(xp, s);
         clen += ptr2cells(s);
-        if ((l = utfc_ptr2len(s)) > 1) {
+        if ((l = utfc_ptr2len((char *)s)) > 1) {
           STRNCPY(buf + len, s, l);  // NOLINT(runtime/printf)
           s += l - 1;
           len += l;
@@ -5232,8 +5232,8 @@ static void win_redr_status(win_T *wp)
       // Find first character that will fit.
       // Going from start to end is much faster for DBCS.
       for (i = 0; p[i] != NUL && clen >= this_ru_col - 1;
-           i += utfc_ptr2len(p + i)) {
-        clen -= utf_ptr2cells(p + i);
+           i += utfc_ptr2len((char *)p + i)) {
+        clen -= utf_ptr2cells((char *)p + i);
       }
       len = clen;
       if (i > 0) {
@@ -5883,7 +5883,7 @@ void grid_puts_len(ScreenGrid *grid, char_u *text, int textlen, int row, int col
     if (len > 0) {
       mbyte_blen = utfc_ptr2len_len(ptr, (int)((text + len) - ptr));
     } else {
-      mbyte_blen = utfc_ptr2len(ptr);
+      mbyte_blen = utfc_ptr2len((char *)ptr);
     }
     if (len >= 0) {
       u8c = utfc_ptr2char_len(ptr, u8cc, (int)((text + len) - ptr));
@@ -6506,7 +6506,7 @@ void setcursor(void)
       // With 'rightleft' set and the cursor on a double-wide character,
       // position it on the leftmost column.
       col = curwin->w_width_inner - curwin->w_wcol
-            - ((utf_ptr2cells(get_cursor_pos_ptr()) == 2
+            - ((utf_ptr2cells((char *)get_cursor_pos_ptr()) == 2
                 && vim_isprintc(gchar_cursor())) ? 2 : 1);
     }
 
@@ -7371,8 +7371,8 @@ static void win_redr_ruler(win_T *wp, bool always)
       }
       // Truncate at window boundary.
       o = 0;
-      for (i = 0; buffer[i] != NUL; i += utfc_ptr2len(buffer + i)) {
-        o += utf_ptr2cells(buffer + i);
+      for (i = 0; buffer[i] != NUL; i += utfc_ptr2len((char *)buffer + i)) {
+        o += utf_ptr2cells((char *)buffer + i);
         if (this_ru_col + o > width) {
           buffer[i] = NUL;
           break;
diff --git a/src/nvim/search.c b/src/nvim/search.c
index 0749e53e68..a7a8d2762c 100644
--- a/src/nvim/search.c
+++ b/src/nvim/search.c
@@ -219,7 +219,7 @@ char_u *reverse_text(char_u *s) FUNC_ATTR_NONNULL_RET
   char_u *rev = xmalloc(len + 1);
   size_t rev_i = len;
   for (size_t s_i = 0; s_i < len; s_i++) {
-    const int mb_len = utfc_ptr2len(s + s_i);
+    const int mb_len = utfc_ptr2len((char *)s + s_i);
     rev_i -= mb_len;
     memmove(rev + rev_i, s + s_i, mb_len);
     s_i += mb_len - 1;
@@ -388,10 +388,10 @@ bool pat_has_uppercase(char_u *pat)
   char_u *p = pat;
 
   while (*p != NUL) {
-    const int l = utfc_ptr2len(p);
+    const int l = utfc_ptr2len((char *)p);
 
     if (l > 1) {
-      if (mb_isupper(utf_ptr2char(p))) {
+      if (mb_isupper(utf_ptr2char((char *)p))) {
         return true;
       }
       p += l;
@@ -602,7 +602,7 @@ int searchit(win_T *win, buf_T *buf, pos_T *pos, pos_T *end_pos, Direction dir,
       if ((int)STRLEN(ptr) <= pos->col) {
         start_char_len = 1;
       } else {
-        start_char_len = utfc_ptr2len(ptr + pos->col);
+        start_char_len = utfc_ptr2len((char *)ptr + pos->col);
       }
     } else {
       start_char_len = 1;
@@ -714,7 +714,7 @@ int searchit(win_T *win, buf_T *buf, pos_T *pos, pos_T *end_pos, Direction dir,
               }
 
               if (matchcol == matchpos.col && ptr[matchcol] != NUL) {
-                matchcol += utfc_ptr2len(ptr + matchcol);
+                matchcol += utfc_ptr2len((char *)ptr + matchcol);
               }
 
               if (matchcol == 0 && (options & SEARCH_START)) {
@@ -799,7 +799,7 @@ int searchit(win_T *win, buf_T *buf, pos_T *pos, pos_T *end_pos, Direction dir,
                 // for empty match: advance one char
                 if (matchcol == matchpos.col
                     && ptr[matchcol] != NUL) {
-                  matchcol += utfc_ptr2len(ptr + matchcol);
+                  matchcol += utfc_ptr2len((char *)ptr + matchcol);
                 }
               } else {
                 // Stop when the match is in a next line.
@@ -808,7 +808,7 @@ int searchit(win_T *win, buf_T *buf, pos_T *pos, pos_T *end_pos, Direction dir,
                 }
                 matchcol = matchpos.col;
                 if (ptr[matchcol] != NUL) {
-                  matchcol += utfc_ptr2len(ptr + matchcol);
+                  matchcol += utfc_ptr2len((char *)ptr + matchcol);
                 }
               }
               if (ptr[matchcol] == NUL
@@ -1248,7 +1248,7 @@ int do_search(oparg_T *oap, int dirc, int search_delim, char_u *pat, long count,
       // empty for the search_stat feature.
       if (!cmd_silent) {
         msgbuf[0] = dirc;
-        if (utf_iscomposing(utf_ptr2char(p))) {
+        if (utf_iscomposing(utf_ptr2char((char *)p))) {
           // Use a space to draw the composing char on.
           msgbuf[1] = ' ';
           memmove(msgbuf + 2, p, STRLEN(p));
@@ -1593,7 +1593,7 @@ int searchc(cmdarg_T *cap, int t_cmd)
   while (count--) {
     for (;;) {
       if (dir > 0) {
-        col += utfc_ptr2len(p + col);
+        col += utfc_ptr2len((char *)p + col);
         if (col >= len) {
           return FAIL;
         }
@@ -1709,31 +1709,31 @@ static void find_mps_values(int *initc, int *findc, bool *backwards, bool switch
   char_u *ptr = curbuf->b_p_mps;
 
   while (*ptr != NUL) {
-    if (utf_ptr2char(ptr) == *initc) {
+    if (utf_ptr2char((char *)ptr) == *initc) {
       if (switchit) {
         *findc = *initc;
-        *initc = utf_ptr2char(ptr + utfc_ptr2len(ptr) + 1);
+        *initc = utf_ptr2char((char *)ptr + utfc_ptr2len((char *)ptr) + 1);
         *backwards = true;
       } else {
-        *findc = utf_ptr2char(ptr + utfc_ptr2len(ptr) + 1);
+        *findc = utf_ptr2char((char *)ptr + utfc_ptr2len((char *)ptr) + 1);
         *backwards = false;
       }
       return;
     }
     char_u *prev = ptr;
-    ptr += utfc_ptr2len(ptr) + 1;
-    if (utf_ptr2char(ptr) == *initc) {
+    ptr += utfc_ptr2len((char *)ptr) + 1;
+    if (utf_ptr2char((char *)ptr) == *initc) {
       if (switchit) {
         *findc = *initc;
-        *initc = utf_ptr2char(prev);
+        *initc = utf_ptr2char((char *)prev);
         *backwards = false;
       } else {
-        *findc = utf_ptr2char(prev);
+        *findc = utf_ptr2char((char *)prev);
         *backwards = true;
       }
       return;
     }
-    ptr += utfc_ptr2len(ptr);
+    ptr += utfc_ptr2len((char *)ptr);
     if (*ptr == ',') {
       ptr++;
     }
@@ -1880,7 +1880,7 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
           --pos.col;
         }
         for (;;) {
-          initc = utf_ptr2char(linep + pos.col);
+          initc = utf_ptr2char((char *)linep + pos.col);
           if (initc == NUL) {
             break;
           }
@@ -1889,7 +1889,7 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
           if (findc) {
             break;
           }
-          pos.col += utfc_ptr2len(linep + pos.col);
+          pos.col += utfc_ptr2len((char *)linep + pos.col);
         }
         if (!findc) {
           // no brace in the line, maybe use "  #if" then
@@ -2061,7 +2061,7 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
           comment_col = check_linecomment(linep);
         }
       } else {
-        pos.col += utfc_ptr2len(linep + pos.col);
+        pos.col += utfc_ptr2len((char *)linep + pos.col);
       }
     }
 
@@ -2206,7 +2206,7 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
      *   inquote if the number of quotes in a line is even, unless this
      *   line or the previous one ends in a '\'.  Complicated, isn't it?
      */
-    const int c = utf_ptr2char(linep + pos.col);
+    const int c = utf_ptr2char((char *)linep + pos.col);
     switch (c) {
     case NUL:
       // at end of line without trailing backslash, reset inquote
@@ -2388,14 +2388,14 @@ void showmatch(int c)
    */
   // 'matchpairs' is "x:y,x:y"
   for (p = curbuf->b_p_mps; *p != NUL; p++) {
-    if (utf_ptr2char(p) == c && (curwin->w_p_rl ^ p_ri)) {
+    if (utf_ptr2char((char *)p) == c && (curwin->w_p_rl ^ p_ri)) {
       break;
     }
-    p += utfc_ptr2len(p) + 1;
-    if (utf_ptr2char(p) == c && !(curwin->w_p_rl ^ p_ri)) {
+    p += utfc_ptr2len((char *)p) + 1;
+    if (utf_ptr2char((char *)p) == c && !(curwin->w_p_rl ^ p_ri)) {
       break;
     }
-    p += utfc_ptr2len(p);
+    p += utfc_ptr2len((char *)p);
     if (*p == NUL) {
       return;
     }
@@ -3972,7 +3972,7 @@ static int find_next_quote(char_u *line, int col, int quotechar, char_u *escape)
     } else if (c == quotechar) {
       break;
     }
-    col += utfc_ptr2len(line + col);
+    col += utfc_ptr2len((char *)line + col);
   }
   return col;
 }
@@ -4883,10 +4883,10 @@ static int fuzzy_match_compute_score(const char_u *const str, const int strSz,
       int neighbor;
 
       for (uint32_t sidx = 0; sidx < currIdx; sidx++) {
-        neighbor = utf_ptr2char(p);
+        neighbor = utf_ptr2char((char *)p);
         MB_PTR_ADV(p);
       }
-      const int curr = utf_ptr2char(p);
+      const int curr = utf_ptr2char((char *)p);
 
       if (mb_islower(neighbor) && mb_isupper(curr)) {
         score += CAMEL_BONUS;
@@ -4934,8 +4934,8 @@ static int fuzzy_match_recursive(const char_u *fuzpat, const char_u *str, uint32
   // Loop through fuzpat and str looking for a match
   bool first_match = true;
   while (*fuzpat != NUL && *str != NUL) {
-    const int c1 = utf_ptr2char(fuzpat);
-    const int c2 = utf_ptr2char(str);
+    const int c1 = utf_ptr2char((char *)fuzpat);
+    const int c2 = utf_ptr2char((char *)str);
 
     // Found match
     if (mb_tolower(c1) == mb_tolower(c2)) {
@@ -4953,7 +4953,7 @@ static int fuzzy_match_recursive(const char_u *fuzpat, const char_u *str, uint32
       // Recursive call that "skips" this match
       uint32_t recursiveMatches[MAX_FUZZY_MATCHES];
       int recursiveScore = 0;
-      const char_u *const next_char = str + utfc_ptr2len(str);
+      const char_u *const next_char = str + utfc_ptr2len((char *)str);
       if (fuzzy_match_recursive(fuzpat, next_char, strIdx + 1, &recursiveScore, strBegin, strLen,
                                 matches, recursiveMatches,
                                 sizeof(recursiveMatches) / sizeof(recursiveMatches[0]), nextMatch,
@@ -5034,7 +5034,7 @@ bool fuzzy_match(char_u *const str, const char_u *const pat_arg, const bool matc
         break;
       }
       pat = p;
-      while (*p != NUL && !ascii_iswhite(utf_ptr2char(p))) {
+      while (*p != NUL && !ascii_iswhite(utf_ptr2char((char *)p))) {
         MB_PTR_ADV(p);
       }
       if (*p == NUL) {  // processed all the words
@@ -5157,7 +5157,7 @@ static void fuzzy_match_in_list(list_T *const l, char_u *const str, const bool m
         int j = 0;
         const char_u *p = str;
         while (*p != NUL) {
-          if (!ascii_iswhite(utf_ptr2char(p))) {
+          if (!ascii_iswhite(utf_ptr2char((char *)p))) {
             tv_list_append_number(items[match_count].lmatchpos, matches[j]);
             j++;
           }
@@ -5839,7 +5839,7 @@ exit_matched:
           && action == ACTION_EXPAND
           && !(compl_cont_status & CONT_SOL)
           && *startp != NUL
-          && *(p = startp + utfc_ptr2len(startp)) != NUL) {
+          && *(p = startp + utfc_ptr2len((char *)startp)) != NUL) {
         goto search_line;
       }
     }
diff --git a/src/nvim/sign.c b/src/nvim/sign.c
index e2d40b4a21..6e1ae1fdec 100644
--- a/src/nvim/sign.c
+++ b/src/nvim/sign.c
@@ -884,11 +884,11 @@ static int sign_define_init_text(sign_T *sp, char_u *text)
   }
   // Count cells and check for non-printable chars
   cells = 0;
-  for (s = text; s < endp; s += utfc_ptr2len(s)) {
-    if (!vim_isprintc(utf_ptr2char(s))) {
+  for (s = text; s < endp; s += utfc_ptr2len((char *)s)) {
+    if (!vim_isprintc(utf_ptr2char((char *)s))) {
       break;
     }
-    cells += utf_ptr2cells(s);
+    cells += utf_ptr2cells((char *)s);
   }
   // Currently must be empty, one or two display cells
   if (s != endp || cells > 2) {
diff --git a/src/nvim/spell.c b/src/nvim/spell.c
index ae3d475f36..047558b0cf 100644
--- a/src/nvim/spell.c
+++ b/src/nvim/spell.c
@@ -397,7 +397,7 @@ size_t spell_check(win_T *wp, char_u *ptr, hlf_T *attrp, int *capcol, bool docou
     bool this_upper = false;  // init for gcc
 
     if (use_camel_case) {
-      c = utf_ptr2char(mi.mi_fend);
+      c = utf_ptr2char((char *)mi.mi_fend);
       this_upper = SPELL_ISUPPER(c);
     }
 
@@ -405,7 +405,7 @@ size_t spell_check(win_T *wp, char_u *ptr, hlf_T *attrp, int *capcol, bool docou
       MB_PTR_ADV(mi.mi_fend);
       if (use_camel_case) {
         const bool prev_upper = this_upper;
-        c = utf_ptr2char(mi.mi_fend);
+        c = utf_ptr2char((char *)mi.mi_fend);
         this_upper = SPELL_ISUPPER(c);
         camel_case = !prev_upper && this_upper;
       }
@@ -414,7 +414,7 @@ size_t spell_check(win_T *wp, char_u *ptr, hlf_T *attrp, int *capcol, bool docou
 
     if (capcol != NULL && *capcol == 0 && wp->w_s->b_cap_prog != NULL) {
       // Check word starting with capital letter.
-      c = utf_ptr2char(ptr);
+      c = utf_ptr2char((char *)ptr);
       if (!SPELL_ISUPPER(c)) {
         wrongcaplen = (size_t)(mi.mi_fend - ptr);
       }
@@ -512,7 +512,7 @@ size_t spell_check(win_T *wp, char_u *ptr, hlf_T *attrp, int *capcol, bool docou
         }
       }
 
-      return (size_t)(utfc_ptr2len(ptr));
+      return (size_t)(utfc_ptr2len((char *)ptr));
     } else if (mi.mi_end == ptr) {
       // Always include at least one character.  Required for when there
       // is a mixup in "midword".
@@ -2023,8 +2023,8 @@ static int count_syllables(slang_T *slang, const char_u *word)
       skip = false;
     } else {
       // No recognized syllable item, at least a syllable char then?
-      c = utf_ptr2char(p);
-      len = utfc_ptr2len(p);
+      c = utf_ptr2char((char *)p);
+      len = utfc_ptr2len((char *)p);
       if (vim_strchr(slang->sl_syllable, c) == NULL) {
         skip = false;               // No, search for next syllable
       } else if (!skip) {
@@ -2355,8 +2355,8 @@ static void use_midword(slang_T *lp, win_T *wp)
   }
 
   for (char_u *p = lp->sl_midword; *p != NUL;) {
-    const int c = utf_ptr2char(p);
-    const int l = utfc_ptr2len(p);
+    const int c = utf_ptr2char((char *)p);
+    const int l = utfc_ptr2len((char *)p);
     if (c < 256 && l <= 2) {
       wp->w_s->b_spell_ismw[c] = true;
     } else if (wp->w_s->b_spell_ismw_mb == NULL) {
@@ -2423,7 +2423,7 @@ int captype(char_u *word, char_u *end)
   // But a word with an upper char only at start is a ONECAP.
   for (; end == NULL ? *p != NUL : p < end; MB_PTR_ADV(p)) {
     if (spell_iswordp_nmw(p, curwin)) {
-      c = utf_ptr2char(p);
+      c = utf_ptr2char((char *)p);
       if (!SPELL_ISUPPER(c)) {
         // UUl -> KEEPCAP
         if (past_second && allcap) {
@@ -2464,7 +2464,7 @@ static int badword_captype(char_u *word, char_u *end)
     l = u = 0;
     first = false;
     for (p = word; p < end; MB_PTR_ADV(p)) {
-      c = utf_ptr2char(p);
+      c = utf_ptr2char((char *)p);
       if (SPELL_ISUPPER(c)) {
         ++u;
         if (p == word) {
@@ -2674,7 +2674,7 @@ static bool spell_iswordp(const char_u *p, const win_T *wp)
 {
   int c;
 
-  const int l = utfc_ptr2len(p);
+  const int l = utfc_ptr2len((char *)p);
   const char_u *s = p;
   if (l == 1) {
     // be quick for ASCII
@@ -2682,7 +2682,7 @@ static bool spell_iswordp(const char_u *p, const win_T *wp)
       s = p + 1;                      // skip a mid-word character
     }
   } else {
-    c = utf_ptr2char(p);
+    c = utf_ptr2char((char *)p);
     if (c < 256
         ? wp->w_s->b_spell_ismw[c]
         : (wp->w_s->b_spell_ismw_mb != NULL
@@ -2691,7 +2691,7 @@ static bool spell_iswordp(const char_u *p, const win_T *wp)
     }
   }
 
-  c = utf_ptr2char(s);
+  c = utf_ptr2char((char *)s);
   if (c > 255) {
     return spell_mb_isword_class(mb_get_class(s), wp);
   }
@@ -2702,7 +2702,7 @@ static bool spell_iswordp(const char_u *p, const win_T *wp)
 // Unlike spell_iswordp() this doesn't check for "midword" characters.
 bool spell_iswordp_nmw(const char_u *p, win_T *wp)
 {
-  int c = utf_ptr2char(p);
+  int c = utf_ptr2char((char *)p);
   if (c > 255) {
     return spell_mb_isword_class(mb_get_class(p), wp);
   }
@@ -3314,7 +3314,7 @@ static void spell_find_suggest(char_u *badptr, int badlen, suginfo_T *su, int ma
   // If the word is not capitalised and spell_check() doesn't consider the
   // word to be bad then it might need to be capitalised.  Add a suggestion
   // for that.
-  c = utf_ptr2char(su->su_badptr);
+  c = utf_ptr2char((char *)su->su_badptr);
   if (!SPELL_ISUPPER(c) && attr == HLF_COUNT) {
     make_case_word(su->su_badword, buf, WF_ONECAP);
     add_suggestion(su, &su->su_ga, buf, su->su_badlen, SCORE_ICASE,
@@ -4009,7 +4009,7 @@ static void suggest_trie_walk(suginfo_T *su, langp_T *lp, char_u *fword, bool so
         c = su->su_badflags;
         if ((c & WF_ALLCAP)
             && su->su_badlen ==
-            utfc_ptr2len(su->su_badptr)) {
+            utfc_ptr2len((char *)su->su_badptr)) {
           c = WF_ONECAP;
         }
         c |= flags;
@@ -4258,7 +4258,7 @@ static void suggest_trie_walk(suginfo_T *su, langp_T *lp, char_u *fword, bool so
                 && goodword_ends) {
               int l;
 
-              l = utfc_ptr2len(fword + sp->ts_fidx);
+              l = utfc_ptr2len((char *)fword + sp->ts_fidx);
               if (fword_ends) {
                 // Copy the skipped character to preword.
                 memmove(preword + sp->ts_prewordlen,
@@ -4405,22 +4405,22 @@ static void suggest_trie_walk(suginfo_T *su, langp_T *lp, char_u *fword, bool so
               // Correct ts_fidx for the byte length of the
               // character (we didn't check that before).
               sp->ts_fidx = sp->ts_fcharstart
-                            + utfc_ptr2len(fword + sp->ts_fcharstart);
+                            + utfc_ptr2len((char *)fword + sp->ts_fcharstart);
 
               // For changing a composing character adjust
               // the score from SCORE_SUBST to
               // SCORE_SUBCOMP.
-              if (utf_iscomposing(utf_ptr2char(tword + sp->ts_twordlen
+              if (utf_iscomposing(utf_ptr2char((char *)tword + sp->ts_twordlen
                                                - sp->ts_tcharlen))
-                  && utf_iscomposing(utf_ptr2char(fword
+                  && utf_iscomposing(utf_ptr2char((char *)fword
                                                   + sp->ts_fcharstart))) {
                 sp->ts_score -= SCORE_SUBST - SCORE_SUBCOMP;
-              } else if (
-                         !soundfold
+              } else if (!soundfold
                          && slang->sl_has_map
                          && similar_chars(slang,
-                                          utf_ptr2char(tword + sp->ts_twordlen - sp->ts_tcharlen),
-                                          utf_ptr2char(fword + sp->ts_fcharstart))) {
+                                          utf_ptr2char((char *)tword + sp->ts_twordlen -
+                                                       sp->ts_tcharlen),
+                                          utf_ptr2char((char *)fword + sp->ts_fcharstart))) {
                 // For a similar character adjust score from
                 // SCORE_SUBST to SCORE_SIMILAR.
                 sp->ts_score -= SCORE_SUBST - SCORE_SIMILAR;
@@ -4428,7 +4428,7 @@ static void suggest_trie_walk(suginfo_T *su, langp_T *lp, char_u *fword, bool so
             } else if (sp->ts_isdiff == DIFF_INSERT
                        && sp->ts_twordlen > sp->ts_tcharlen) {
               p = tword + sp->ts_twordlen - sp->ts_tcharlen;
-              c = utf_ptr2char(p);
+              c = utf_ptr2char((char *)p);
               if (utf_iscomposing(c)) {
                 // Inserting a composing char doesn't
                 // count that much.
@@ -4440,7 +4440,7 @@ static void suggest_trie_walk(suginfo_T *su, langp_T *lp, char_u *fword, bool so
                 // tree (might seem illogical but does
                 // give better scores).
                 MB_PTR_BACK(tword, p);
-                if (c == utf_ptr2char(p)) {
+                if (c == utf_ptr2char((char *)p)) {
                   sp->ts_score -= SCORE_INS - SCORE_INSDUP;
                 }
               }
@@ -4491,11 +4491,11 @@ static void suggest_trie_walk(suginfo_T *su, langp_T *lp, char_u *fword, bool so
         // score if the same character is following "nn" -> "n".  It's
         // a bit illogical for soundfold tree but it does give better
         // results.
-        c = utf_ptr2char(fword + sp->ts_fidx);
-        stack[depth].ts_fidx += utfc_ptr2len(fword + sp->ts_fidx);
+        c = utf_ptr2char((char *)fword + sp->ts_fidx);
+        stack[depth].ts_fidx += utfc_ptr2len((char *)fword + sp->ts_fidx);
         if (utf_iscomposing(c)) {
           stack[depth].ts_score -= SCORE_DEL - SCORE_DELCOMP;
-        } else if (c == utf_ptr2char(fword + stack[depth].ts_fidx)) {
+        } else if (c == utf_ptr2char((char *)fword + stack[depth].ts_fidx)) {
           stack[depth].ts_score -= SCORE_DEL - SCORE_DELDUP;
         }
 
@@ -4610,14 +4610,14 @@ static void suggest_trie_walk(suginfo_T *su, langp_T *lp, char_u *fword, bool so
         break;
       }
 
-      n = utf_ptr2len(p);
-      c = utf_ptr2char(p);
+      n = utf_ptr2len((char *)p);
+      c = utf_ptr2char((char *)p);
       if (p[n] == NUL) {
         c2 = NUL;
       } else if (!soundfold && !spell_iswordp(p + n, curwin)) {
         c2 = c;  // don't swap non-word char
       } else {
-        c2 = utf_ptr2char(p + n);
+        c2 = utf_ptr2char((char *)p + n);
       }
 
       // When the second character is NUL we can't swap.
@@ -4659,9 +4659,9 @@ static void suggest_trie_walk(suginfo_T *su, langp_T *lp, char_u *fword, bool so
     case STATE_UNSWAP:
       // Undo the STATE_SWAP swap: "21" -> "12".
       p = fword + sp->ts_fidx;
-      n = utfc_ptr2len(p);
-      c = utf_ptr2char(p + n);
-      memmove(p + utfc_ptr2len(p + n), p, n);
+      n = utfc_ptr2len((char *)p);
+      c = utf_ptr2char((char *)p + n);
+      memmove(p + utfc_ptr2len((char *)p + n), p, n);
       utf_char2bytes(c, p);
 
       FALLTHROUGH;
@@ -4670,14 +4670,14 @@ static void suggest_trie_walk(suginfo_T *su, langp_T *lp, char_u *fword, bool so
       // Swap two bytes, skipping one: "123" -> "321".  We change
       // "fword" here, it's changed back afterwards at STATE_UNSWAP3.
       p = fword + sp->ts_fidx;
-      n = utf_ptr2len(p);
-      c = utf_ptr2char(p);
-      fl = utf_ptr2len(p + n);
-      c2 = utf_ptr2char(p + n);
+      n = utf_ptr2len((char *)p);
+      c = utf_ptr2char((char *)p);
+      fl = utf_ptr2len((char *)p + n);
+      c2 = utf_ptr2char((char *)p + n);
       if (!soundfold && !spell_iswordp(p + n + fl, curwin)) {
         c3 = c;  // don't swap non-word char
       } else {
-        c3 = utf_ptr2char(p + n + fl);
+        c3 = utf_ptr2char((char *)p + n + fl);
       }
 
       // When characters are identical: "121" then SWAP3 result is
@@ -4715,11 +4715,11 @@ static void suggest_trie_walk(suginfo_T *su, langp_T *lp, char_u *fword, bool so
     case STATE_UNSWAP3:
       // Undo STATE_SWAP3: "321" -> "123"
       p = fword + sp->ts_fidx;
-      n = utfc_ptr2len(p);
-      c2 = utf_ptr2char(p + n);
-      fl = utfc_ptr2len(p + n);
-      c = utf_ptr2char(p + n + fl);
-      tl = utfc_ptr2len(p + n + fl);
+      n = utfc_ptr2len((char *)p);
+      c2 = utf_ptr2char((char *)p + n);
+      fl = utfc_ptr2len((char *)p + n);
+      c = utf_ptr2char((char *)p + n + fl);
+      tl = utfc_ptr2len((char *)p + n + fl);
       memmove(p + fl + tl, p, n);
       utf_char2bytes(c, p);
       utf_char2bytes(c2, p + tl);
@@ -4747,10 +4747,10 @@ static void suggest_trie_walk(suginfo_T *su, langp_T *lp, char_u *fword, bool so
         sp->ts_state = STATE_UNROT3L;
         ++depth;
         p = fword + sp->ts_fidx;
-        n = utf_ptr2len(p);
-        c = utf_ptr2char(p);
-        fl = utf_ptr2len(p + n);
-        fl += utf_ptr2len(p + n + fl);
+        n = utf_ptr2len((char *)p);
+        c = utf_ptr2char((char *)p);
+        fl = utf_ptr2len((char *)p + n);
+        fl += utf_ptr2len((char *)p + n + fl);
         memmove(p, p + n, fl);
         utf_char2bytes(c, p + fl);
         stack[depth].ts_fidxtry = sp->ts_fidx + n + fl;
@@ -4763,10 +4763,10 @@ static void suggest_trie_walk(suginfo_T *su, langp_T *lp, char_u *fword, bool so
     case STATE_UNROT3L:
       // Undo ROT3L: "231" -> "123"
       p = fword + sp->ts_fidx;
-      n = utfc_ptr2len(p);
-      n += utfc_ptr2len(p + n);
-      c = utf_ptr2char(p + n);
-      tl = utfc_ptr2len(p + n);
+      n = utfc_ptr2len((char *)p);
+      n += utfc_ptr2len((char *)p + n);
+      c = utf_ptr2char((char *)p + n);
+      tl = utfc_ptr2len((char *)p + n);
       memmove(p + tl, p, n);
       utf_char2bytes(c, p);
 
@@ -4784,10 +4784,10 @@ static void suggest_trie_walk(suginfo_T *su, langp_T *lp, char_u *fword, bool so
         sp->ts_state = STATE_UNROT3R;
         ++depth;
         p = fword + sp->ts_fidx;
-        n = utf_ptr2len(p);
-        n += utf_ptr2len(p + n);
-        c = utf_ptr2char(p + n);
-        tl = utf_ptr2len(p + n);
+        n = utf_ptr2len((char *)p);
+        n += utf_ptr2len((char *)p + n);
+        c = utf_ptr2char((char *)p + n);
+        tl = utf_ptr2len((char *)p + n);
         memmove(p + tl, p, n);
         utf_char2bytes(c, p);
         stack[depth].ts_fidxtry = sp->ts_fidx + n + tl;
@@ -4800,10 +4800,10 @@ static void suggest_trie_walk(suginfo_T *su, langp_T *lp, char_u *fword, bool so
     case STATE_UNROT3R:
       // Undo ROT3R: "312" -> "123"
       p = fword + sp->ts_fidx;
-      c = utf_ptr2char(p);
-      tl = utfc_ptr2len(p);
-      n = utfc_ptr2len(p + tl);
-      n += utfc_ptr2len(p + tl + n);
+      c = utf_ptr2char((char *)p);
+      tl = utfc_ptr2len((char *)p);
+      n = utfc_ptr2len((char *)p + tl);
+      n += utfc_ptr2len((char *)p + tl + n);
       memmove(p, p + tl, n);
       utf_char2bytes(c, p + n);
 
@@ -5025,8 +5025,8 @@ static void find_keepcap_word(slang_T *slang, char_u *fword, char_u *kword)
     } else {
       // round[depth] == 1: Try using the folded-case character.
       // round[depth] == 2: Try using the upper-case character.
-      flen = utf_ptr2len(fword + fwordidx[depth]);
-      ulen = utf_ptr2len(uword + uwordidx[depth]);
+      flen = utf_ptr2len((char *)fword + fwordidx[depth]);
+      ulen = utf_ptr2len((char *)uword + uwordidx[depth]);
       if (round[depth] == 1) {
         p = fword + fwordidx[depth];
         l = flen;
@@ -5516,9 +5516,9 @@ badword:
         // lower to upper case.  Helps for "tath" -> "Kath", which is
         // less common than "tath" -> "path".  Don't do it when the
         // letter is the same, that has already been counted.
-        gc = utf_ptr2char(p);
+        gc = utf_ptr2char((char *)p);
         if (SPELL_ISUPPER(gc)) {
-          bc = utf_ptr2char(su->su_badword);
+          bc = utf_ptr2char((char *)su->su_badword);
           if (!SPELL_ISUPPER(bc)
               && SPELL_TOFOLD(bc) != SPELL_TOFOLD(gc)) {
             goodscore += SCORE_ICASE / 2;
@@ -5661,7 +5661,7 @@ static bool similar_chars(slang_T *slang, int c1, int c2)
     if (HASHITEM_EMPTY(hi)) {
       m1 = 0;
     } else {
-      m1 = utf_ptr2char(hi->hi_key + STRLEN(hi->hi_key) + 1);
+      m1 = utf_ptr2char((char *)hi->hi_key + STRLEN(hi->hi_key) + 1);
     }
   } else {
     m1 = slang->sl_map_array[c1];
@@ -5676,7 +5676,7 @@ static bool similar_chars(slang_T *slang, int c1, int c2)
     if (HASHITEM_EMPTY(hi)) {
       m2 = 0;
     } else {
-      m2 = utf_ptr2char(hi->hi_key + STRLEN(hi->hi_key) + 1);
+      m2 = utf_ptr2char((char *)hi->hi_key + STRLEN(hi->hi_key) + 1);
     }
   } else {
     m2 = slang->sl_map_array[c2];
@@ -5713,7 +5713,7 @@ static void add_suggestion(suginfo_T *su, garray_T *gap, const char_u *goodword,
     }
     MB_PTR_BACK(goodword, pgood);
     MB_PTR_BACK(su->su_badptr, pbad);
-    if (utf_ptr2char(pgood) != utf_ptr2char(pbad)) {
+    if (utf_ptr2char((char *)pgood) != utf_ptr2char((char *)pbad)) {
       break;
     }
   }
@@ -6940,7 +6940,7 @@ void spell_dump_compl(char_u *pat, int ic, Direction *dir, int dumpflags_arg)
       if (n == WF_ONECAP) {
         dumpflags |= DUMPFLAG_ONECAP;
       } else if (n == WF_ALLCAP
-                 && (int)STRLEN(pat) > utfc_ptr2len(pat)) {
+                 && (int)STRLEN(pat) > utfc_ptr2len((char *)pat)) {
         dumpflags |= DUMPFLAG_ALLCAP;
       }
     }
@@ -7189,7 +7189,7 @@ static linenr_T dump_prefixes(slang_T *slang, char_u *word, char_u *pat, Directi
 
   // If the word starts with a lower-case letter make the word with an
   // upper-case letter in word_up[].
-  c = utf_ptr2char(word);
+  c = utf_ptr2char((char *)word);
   if (SPELL_TOUPPER(c) != c) {
     onecap_copy(word, word_up, true);
     has_word_up = true;
diff --git a/src/nvim/spellfile.c b/src/nvim/spellfile.c
index c1b116e498..d4c0f389fb 100644
--- a/src/nvim/spellfile.c
+++ b/src/nvim/spellfile.c
@@ -2504,19 +2504,19 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
             // be empty or start with the same letter.
             if (aff_entry->ae_chop != NULL
                 && aff_entry->ae_add != NULL
-                && aff_entry->ae_chop[utfc_ptr2len(aff_entry->ae_chop)] ==
+                && aff_entry->ae_chop[utfc_ptr2len((char *)aff_entry->ae_chop)] ==
                 NUL) {
               int c, c_up;
 
-              c = utf_ptr2char(aff_entry->ae_chop);
+              c = utf_ptr2char((char *)aff_entry->ae_chop);
               c_up = SPELL_TOUPPER(c);
               if (c_up != c
                   && (aff_entry->ae_cond == NULL
-                      || utf_ptr2char(aff_entry->ae_cond) == c)) {
+                      || utf_ptr2char((char *)aff_entry->ae_cond) == c)) {
                 p = aff_entry->ae_add
                     + STRLEN(aff_entry->ae_add);
                 MB_PTR_BACK(aff_entry->ae_add, p);
-                if (utf_ptr2char(p) == c_up) {
+                if (utf_ptr2char((char *)p) == c_up) {
                   upper = true;
                   aff_entry->ae_chop = NULL;
                   *p = NUL;
diff --git a/src/nvim/strings.c b/src/nvim/strings.c
index a897228d6b..6582e6075a 100644
--- a/src/nvim/strings.c
+++ b/src/nvim/strings.c
@@ -98,7 +98,7 @@ char_u *vim_strsave_escaped_ext(const char_u *string, const char_u *esc_chars, c
    */
   size_t length = 1;                    // count the trailing NUL
   for (const char_u *p = string; *p; p++) {
-    const size_t l = (size_t)(utfc_ptr2len(p));
+    const size_t l = (size_t)(utfc_ptr2len((char *)p));
     if (l > 1) {
       length += l;                      // count a multibyte char
       p += l - 1;
@@ -113,7 +113,7 @@ char_u *vim_strsave_escaped_ext(const char_u *string, const char_u *esc_chars, c
   char_u *escaped_string = xmalloc(length);
   char_u *p2 = escaped_string;
   for (const char_u *p = string; *p; p++) {
-    const size_t l = (size_t)(utfc_ptr2len(p));
+    const size_t l = (size_t)(utfc_ptr2len((char *)p));
     if (l > 1) {
       memcpy(p2, p, l);
       p2 += l;
@@ -357,8 +357,8 @@ char *strcase_save(const char *const orig, bool upper)
 
   char *p = res;
   while (*p != NUL) {
-    int c = utf_ptr2char((const char_u *)p);
-    int l = utf_ptr2len((const char_u *)p);
+    int c = utf_ptr2char(p);
+    int l = utf_ptr2len(p);
     if (c == 0) {
       // overlong sequence, use only the first byte
       c = (char_u)(*p);
@@ -1011,8 +1011,8 @@ int vim_vsnprintf_typval(char *str, size_t str_m, const char *fmt, va_list ap, t
             char_u *p1;
             size_t i;
 
-            for (i = 0, p1 = (char_u *)str_arg; *p1; p1 += utfc_ptr2len(p1)) {
-              size_t cell = (size_t)utf_ptr2cells(p1);
+            for (i = 0, p1 = (char_u *)str_arg; *p1; p1 += utfc_ptr2len((char *)p1)) {
+              size_t cell = (size_t)utf_ptr2cells((char *)p1);
               if (precision_specified && i + cell > precision) {
                 break;
               }
diff --git a/src/nvim/syntax.c b/src/nvim/syntax.c
index 7afabdeb96..422e7150ab 100644
--- a/src/nvim/syntax.c
+++ b/src/nvim/syntax.c
@@ -2968,7 +2968,7 @@ static int check_keyword_id(char_u *const line, const int startcol, int *const e
   char_u *const kwp = line + startcol;
   int kwlen = 0;
   do {
-    kwlen += utfc_ptr2len(kwp + kwlen);
+    kwlen += utfc_ptr2len((char *)kwp + kwlen);
   } while (vim_iswordp_buf(kwp + kwlen, syn_buf));
 
   if (kwlen > MAXKEYWLEN) {
@@ -4178,8 +4178,8 @@ static char_u *get_syn_options(char_u *arg, syn_opt_arg_T *opt, int *conceal_cha
       }
     } else if (flagtab[fidx].argtype == 11 && arg[5] == '=') {
       // cchar=?
-      *conceal_char = utf_ptr2char(arg + 6);
-      arg += utfc_ptr2len(arg + 6) - 1;
+      *conceal_char = utf_ptr2char((char *)arg + 6);
+      arg += utfc_ptr2len((char *)arg + 6) - 1;
       if (!vim_isprintc_strict(*conceal_char)) {
         emsg(_("E844: invalid cchar value"));
         return NULL;
@@ -4416,7 +4416,7 @@ static void syn_cmd_keyword(exarg_T *eap, int syncing)
               kw = p + 1;
               break;   // skip over the "]"
             }
-            const int l = utfc_ptr2len(p + 1);
+            const int l = utfc_ptr2len((char *)p + 1);
 
             memmove(p, p + 1, l);
             p += l;
diff --git a/src/nvim/tag.c b/src/nvim/tag.c
index f2ba5d501c..b9203b4941 100644
--- a/src/nvim/tag.c
+++ b/src/nvim/tag.c
@@ -2583,7 +2583,7 @@ static int parse_match(char_u *lbuf, tagptrs_T *tagp)
       if (*p++ == TAB) {
         // Accept ASCII alphabetic kind characters and any multi-byte
         // character.
-        while (ASCII_ISALPHA(*p) || utfc_ptr2len(p) > 1) {
+        while (ASCII_ISALPHA(*p) || utfc_ptr2len((char *)p) > 1) {
           if (STRNCMP(p, "kind:", 5) == 0) {
             tagp->tagkind = p + 5;
           } else if (STRNCMP(p, "user_data:", 10) == 0) {
diff --git a/src/nvim/terminal.c b/src/nvim/terminal.c
index 385b55e545..1f763c3e1e 100644
--- a/src/nvim/terminal.c
+++ b/src/nvim/terminal.c
@@ -673,8 +673,8 @@ void terminal_paste(long count, char_u **y_array, size_t y_size)
       char_u *dst = buff;
       char_u *src = y_array[j];
       while (*src != '\0') {
-        len = (size_t)utf_ptr2len(src);
-        int c = utf_ptr2char(src);
+        len = (size_t)utf_ptr2len((char *)src);
+        int c = utf_ptr2char((char *)src);
         if (!is_filter_char(c)) {
           memcpy(dst, src, len);
           dst += len;
diff --git a/src/nvim/testing.c b/src/nvim/testing.c
index 07e1fe424b..9207ebe73b 100644
--- a/src/nvim/testing.c
+++ b/src/nvim/testing.c
@@ -90,7 +90,7 @@ static void ga_concat_shorten_esc(garray_T *gap, const char_u *str)
     const char_u *s = p;
     const int c = mb_ptr2char_adv(&s);
     const int clen = (int)(s - p);
-    while (*s != NUL && c == utf_ptr2char(s)) {
+    while (*s != NUL && c == utf_ptr2char((char *)s)) {
       same_len++;
       s += clen;
     }
diff --git a/src/nvim/version.c b/src/nvim/version.c
index fb718d3882..2369681dca 100644
--- a/src/nvim/version.c
+++ b/src/nvim/version.c
@@ -2312,7 +2312,7 @@ static void do_intro_line(long row, char_u *mesg, int attr)
          p[l] != NUL && (l == 0 || (p[l] != '<' && p[l - 1] != '>'));
          l++) {
       clen += ptr2cells(p + l);
-      l += utfc_ptr2len(p + l) - 1;
+      l += utfc_ptr2len((char *)p + l) - 1;
     }
     assert(row <= INT_MAX && col <= INT_MAX);
     grid_puts_len(&default_grid, p, l, (int)row, (int)col,
diff --git a/src/nvim/window.c b/src/nvim/window.c
index 887df31650..9cf1e3eca1 100644
--- a/src/nvim/window.c
+++ b/src/nvim/window.c
@@ -6534,7 +6534,7 @@ char_u *file_name_in_line(char_u *line, int col, int options, long count, char_u
       // Skip over the "\" in "\ ".
       ++len;
     }
-    len += (size_t)(utfc_ptr2len(ptr + len));
+    len += (size_t)(utfc_ptr2len((char *)ptr + len));
   }
 
   /*