Merge pull request #18489 from dundargoc/refactor/remove-char_u

refactor: replace char_u variables and functions with char

48 files changed, 672 insertions, 679 deletions

diff --git a/src/nvim/autocmd.c b/src/nvim/autocmd.c
index c5b576b106..51a0521231 100644
--- a/src/nvim/autocmd.c
+++ b/src/nvim/autocmd.c
@@ -1521,11 +1521,10 @@ bool apply_autocmds(event_T event, char_u *fname, char_u *fname_io, bool force,
 /// @param exarg Ex command arguments
 ///
 /// @return true if some commands were executed.
-bool apply_autocmds_exarg(event_T event, char_u *fname, char_u *fname_io, bool force, buf_T *buf,
+bool apply_autocmds_exarg(event_T event, char *fname, char *fname_io, bool force, buf_T *buf,
                           exarg_T *eap)
 {
-  return apply_autocmds_group(event, (char *)fname, (char *)fname_io, force, AUGROUP_ALL, buf,
-                              eap);
+  return apply_autocmds_group(event, fname, fname_io, force, AUGROUP_ALL, buf, eap);
 }
 
 /// Like apply_autocmds(), but handles the caller's retval.  If the script
@@ -1541,14 +1540,14 @@ bool apply_autocmds_exarg(event_T event, char_u *fname, char_u *fname_io, bool f
 /// @param[in,out] retval caller's retval
 ///
 /// @return true if some autocommands were executed
-bool apply_autocmds_retval(event_T event, char_u *fname, char_u *fname_io, bool force, buf_T *buf,
+bool apply_autocmds_retval(event_T event, char *fname, char *fname_io, bool force, buf_T *buf,
                            int *retval)
 {
   if (should_abort(*retval)) {
     return false;
   }
 
-  bool did_cmd = apply_autocmds_group(event, (char *)fname, (char *)fname_io, force,
+  bool did_cmd = apply_autocmds_group(event, fname, fname_io, force,
                                       AUGROUP_ALL, buf, NULL);
   if (did_cmd && aborting()) {
     *retval = FAIL;
@@ -1659,9 +1658,9 @@ bool apply_autocmds_group(event_T event, char *fname, char *fname_io, bool force
   }
 
   // Save the autocmd_* variables and info about the current buffer.
-  char *save_autocmd_fname = (char *)autocmd_fname;
+  char *save_autocmd_fname = autocmd_fname;
   int save_autocmd_bufnr = autocmd_bufnr;
-  char *save_autocmd_match = (char *)autocmd_match;
+  char *save_autocmd_match = autocmd_match;
   int save_autocmd_busy = autocmd_busy;
   int save_autocmd_nested = autocmd_nested;
   bool save_changed = curbuf->b_changed;
@@ -1675,18 +1674,18 @@ bool apply_autocmds_group(event_T event, char *fname, char *fname_io, bool force
         || event == EVENT_OPTIONSET || event == EVENT_MODECHANGED) {
       autocmd_fname = NULL;
     } else if (fname != NULL && !ends_excmd(*fname)) {
-      autocmd_fname = (char_u *)fname;
+      autocmd_fname = fname;
     } else if (buf != NULL) {
-      autocmd_fname = buf->b_ffname;
+      autocmd_fname = (char *)buf->b_ffname;
     } else {
       autocmd_fname = NULL;
     }
   } else {
-    autocmd_fname = (char_u *)fname_io;
+    autocmd_fname = fname_io;
   }
   if (autocmd_fname != NULL) {
     // Allocate MAXPATHL for when eval_vars() resolves the fullpath.
-    autocmd_fname = vim_strnsave(autocmd_fname, MAXPATHL);
+    autocmd_fname = xstrnsave(autocmd_fname, MAXPATHL);
   }
 
   // Set the buffer number to be used for <abuf>.
@@ -1754,11 +1753,11 @@ bool apply_autocmds_group(event_T event, char *fname, char *fname_io, bool force
 #endif
 
   // Set the name to be used for <amatch>.
-  autocmd_match = (char_u *)fname;
+  autocmd_match = fname;
 
   // Don't redraw while doing autocommands.
   RedrawingDisabled++;
-  char *save_sourcing_name = (char *)sourcing_name;
+  char *save_sourcing_name = sourcing_name;
   sourcing_name = NULL;  // don't free this one
   linenr_T save_sourcing_lnum = sourcing_lnum;
   sourcing_lnum = 0;  // no line number here
@@ -1793,7 +1792,7 @@ bool apply_autocmds_group(event_T event, char *fname, char *fname_io, bool force
     did_filetype = true;
   }
 
-  char *tail = (char *)path_tail((char_u *)fname);
+  char *tail = path_tail(fname);
 
   // Find first autocommand that matches
   AutoPatCmd patcmd;
@@ -1860,12 +1859,12 @@ bool apply_autocmds_group(event_T event, char *fname, char *fname_io, bool force
   filechangeshell_busy = false;
   autocmd_nested = save_autocmd_nested;
   xfree(sourcing_name);
-  sourcing_name = (char_u *)save_sourcing_name;
+  sourcing_name = save_sourcing_name;
   sourcing_lnum = save_sourcing_lnum;
   xfree(autocmd_fname);
-  autocmd_fname = (char_u *)save_autocmd_fname;
+  autocmd_fname = save_autocmd_fname;
   autocmd_bufnr = save_autocmd_bufnr;
-  autocmd_match = (char_u *)save_autocmd_match;
+  autocmd_match = save_autocmd_match;
   current_sctx = save_current_sctx;
   restore_funccal();
   if (do_profiling == PROF_YES) {
@@ -1933,7 +1932,7 @@ void block_autocmds(void)
 {
   // Remember the value of v:termresponse.
   if (!is_autocmd_blocked()) {
-    old_termresponse = (char *)get_vim_var_str(VV_TERMRESPONSE);
+    old_termresponse = get_vim_var_str(VV_TERMRESPONSE);
   }
   autocmd_blocked++;
 }
@@ -1946,7 +1945,7 @@ void unblock_autocmds(void)
   // the autocommands now.  Esp. useful when executing a shell command
   // during startup (nvim -d).
   if (!is_autocmd_blocked()
-      && get_vim_var_str(VV_TERMRESPONSE) != (char_u *)old_termresponse) {
+      && get_vim_var_str(VV_TERMRESPONSE) != old_termresponse) {
     apply_autocmds(EVENT_TERMRESPONSE, NULL, NULL, false, curbuf);
   }
 }
@@ -1979,9 +1978,9 @@ void auto_next_pat(AutoPatCmd *apc, int stop_at_last)
       if (ap->buflocal_nr == 0
           ? match_file_pat(NULL,
                            &ap->reg_prog,
-                           (char_u *)apc->fname,
-                           (char_u *)apc->sfname,
-                           (char_u *)apc->tail,
+                           apc->fname,
+                           apc->sfname,
+                           apc->tail,
                            ap->allow_dirs)
           : ap->buflocal_nr == apc->arg_bufnr) {
         const char *const name = event_nr2name(apc->event);
@@ -1991,7 +1990,7 @@ void auto_next_pat(AutoPatCmd *apc, int stop_at_last)
           = (STRLEN(s) + strlen(name) + (size_t)ap->patlen + 1);
 
         sourcing_name = xmalloc(sourcing_name_len);
-        snprintf((char *)sourcing_name, sourcing_name_len, s, name, ap->pat);
+        snprintf(sourcing_name, sourcing_name_len, s, name, ap->pat);
         if (p_verbose >= 8) {
           verbose_enter();
           smsg(_("Executing %s"), sourcing_name);
@@ -2064,7 +2063,7 @@ static bool call_autocmd_callback(const AutoCmd *ac, const AutoPatCmd *apc)
 /// Get next autocommand command.
 /// Called by do_cmdline() to get the next line for ":if".
 /// @return allocated string, or NULL for end of autocommands.
-char_u *getnextac(int c, void *cookie, int indent, bool do_concat)
+char *getnextac(int c, void *cookie, int indent, bool do_concat)
 {
   // These arguments are required for do_cmdline.
   (void)c;
@@ -2155,7 +2154,7 @@ char_u *getnextac(int c, void *cookie, int indent, bool do_concat)
     acp->nextcmd = ac->next;
   }
 
-  return (char_u *)retval;
+  return retval;
 }
 
 /// Return true if there is a matching autocommand for "fname".
@@ -2165,12 +2164,13 @@ char_u *getnextac(int c, void *cookie, int indent, bool do_concat)
 /// @param event event that occurred.
 /// @param sfname filename the event occurred in.
 /// @param buf buffer the file is open in
-bool has_autocmd(event_T event, char_u *sfname, buf_T *buf) FUNC_ATTR_WARN_UNUSED_RESULT
+bool has_autocmd(event_T event, char *sfname, buf_T *buf)
+  FUNC_ATTR_WARN_UNUSED_RESULT
 {
-  char *tail = (char *)path_tail(sfname);
+  char *tail = path_tail(sfname);
   bool retval = false;
 
-  char *fname = FullName_save((char *)sfname, false);
+  char *fname = FullName_save(sfname, false);
   if (fname == NULL) {
     return false;
   }
@@ -2188,9 +2188,9 @@ bool has_autocmd(event_T event, char_u *sfname, buf_T *buf) FUNC_ATTR_WARN_UNUSE
         && (ap->buflocal_nr == 0
             ? match_file_pat(NULL,
                              &ap->reg_prog,
-                             (char_u *)fname,
+                             fname,
                              sfname,
-                             (char_u *)tail,
+                             tail,
                              ap->allow_dirs)
             : buf != NULL && ap->buflocal_nr == buf->b_fnum)) {
       retval = true;
@@ -2208,12 +2208,12 @@ bool has_autocmd(event_T event, char_u *sfname, buf_T *buf) FUNC_ATTR_WARN_UNUSE
 
 // Function given to ExpandGeneric() to obtain the list of autocommand group
 // names.
-char_u *expand_get_augroup_name(expand_T *xp, int idx)
+char *expand_get_augroup_name(expand_T *xp, int idx)
 {
   // Required for ExpandGeneric
   (void)xp;
 
-  return (char_u *)augroup_name(idx + 1);
+  return augroup_name(idx + 1);
 }
 
 /// @param doautocmd  true for :doauto*, false for :autocmd
@@ -2263,7 +2263,7 @@ char *set_context_in_autocmd(expand_T *xp, char *arg, int doautocmd)
 }
 
 // Function given to ExpandGeneric() to obtain the list of event names.
-char_u *expand_get_event_name(expand_T *xp, int idx)
+char *expand_get_event_name(expand_T *xp, int idx)
 {
   // xp is a required parameter to be used with ExpandGeneric
   (void)xp;
@@ -2273,14 +2273,14 @@ char_u *expand_get_event_name(expand_T *xp, int idx)
   if (name != NULL) {
     // skip when not including groups or skip deleted entries
     if (!autocmd_include_groups || name == get_deleted_augroup()) {
-      return (char_u *)"";
+      return "";
     }
 
-    return (char_u *)name;
+    return name;
   }
 
   // List event names
-  return (char_u *)event_names[idx - next_augroup_id].name;
+  return event_names[idx - next_augroup_id].name;
 }
 
 /// Check whether given autocommand is supported
@@ -2373,7 +2373,7 @@ bool au_exists(const char *const arg) FUNC_ATTR_WARN_UNUSED_RESULT
         && (group == AUGROUP_ALL || ap->group == group)
         && (pattern == NULL
             || (buflocal_buf == NULL
-                ? FNAMECMP(ap->pat, (char_u *)pattern) == 0
+                ? FNAMECMP(ap->pat, pattern) == 0
                 : ap->buflocal_nr == buflocal_buf->b_fnum))) {
       retval = true;
       break;
@@ -2410,7 +2410,7 @@ int aupat_get_buflocal_nr(char *pat, int patlen)
     }
 
     // "<buffer=123>"
-    if (skipdigits((char_u *)pat + 8) == (char_u *)pat + patlen - 1) {
+    if (skipdigits(pat + 8) == pat + patlen - 1) {
       return atoi(pat + 8);
     }
   }
@@ -2434,10 +2434,10 @@ void aupat_normalize_buflocal_pat(char *dest, char *pat, int patlen, int bufloca
            buflocal_nr);
 }
 
-int autocmd_delete_event(int group, event_T event, char_u *pat)
+int autocmd_delete_event(int group, event_T event, char *pat)
   FUNC_ATTR_NONNULL_ALL
 {
-  return do_autocmd_event(event, (char *)pat, false, false, "", true, group);
+  return do_autocmd_event(event, pat, false, false, "", true, group);
 }
 
 /// Deletes an autocmd by ID.
diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index 2c9f997ac1..18c8a2c250 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -111,8 +111,8 @@ static int read_buffer(int read_stdin, exarg_T *eap, int flags)
   // the end.  This makes it possible to retry when 'fileformat' or
   // 'fileencoding' was guessed wrong.
   line_count = curbuf->b_ml.ml_line_count;
-  retval = readfile(read_stdin ? NULL : curbuf->b_ffname,
-                    read_stdin ? NULL : curbuf->b_fname,
+  retval = readfile(read_stdin ? NULL : (char *)curbuf->b_ffname,
+                    read_stdin ? NULL : (char *)curbuf->b_fname,
                     line_count, (linenr_T)0, (linenr_T)MAXLNUM, eap,
                     flags | READ_BUFFER, silent);
   if (retval == OK) {
@@ -229,7 +229,7 @@ int open_buffer(int read_stdin, exarg_T *eap, int flags)
     }
 #endif
 
-    retval = readfile(curbuf->b_ffname, curbuf->b_fname,
+    retval = readfile((char *)curbuf->b_ffname, (char *)curbuf->b_fname,
                       (linenr_T)0, (linenr_T)0, (linenr_T)MAXLNUM, eap,
                       flags | READ_NEW | (read_fifo ? READ_FIFO : 0), silent);
 #ifdef UNIX
@@ -3175,7 +3175,7 @@ void maketitle(void)
                                      SPACE_FOR_FNAME + 1);
         buf_p += MIN(size, SPACE_FOR_FNAME);
       } else {
-        buf_p += transstr_buf((const char *)path_tail(curbuf->b_fname),
+        buf_p += transstr_buf((const char *)path_tail((char *)curbuf->b_fname),
                               buf_p, SPACE_FOR_FNAME + 1, true);
       }
 
@@ -3285,7 +3285,7 @@ void maketitle(void)
       if (buf_spname(curbuf) != NULL) {
         buf_p = buf_spname(curbuf);
       } else {                        // use file name only in icon
-        buf_p = path_tail(curbuf->b_ffname);
+        buf_p = (char_u *)path_tail((char *)curbuf->b_ffname);
       }
       *icon_str = NUL;
       // Truncate name at 100 bytes.
@@ -3841,7 +3841,7 @@ int build_stl_str_hl(win_T *wp, char *out, size_t outlen, char *fmt, int use_san
       if (opt != STL_FILENAME) {
         str = (char *)NameBuff;
       } else {
-        str = (char *)path_tail(NameBuff);
+        str = path_tail((char *)NameBuff);
       }
       break;
     case STL_VIM_EXPR:     // '{'
@@ -3909,7 +3909,7 @@ int build_stl_str_hl(win_T *wp, char *out, size_t outlen, char *fmt, int use_san
       // Check if the evaluated result is a number.
       // If so, convert the number to an int and free the string.
       if (str != NULL && *str != 0) {
-        if (*skipdigits((char_u *)str) == NUL) {
+        if (*skipdigits(str) == NUL) {
           num = atoi(str);
           XFREE_CLEAR(str);
           itemisflag = false;
@@ -5201,9 +5201,9 @@ static int chk_modeline(linenr_T lnum, int flags)
   s = linecopy = vim_strsave(s);      // copy the line, it will change
 
   save_sourcing_lnum = sourcing_lnum;
-  save_sourcing_name = sourcing_name;
+  save_sourcing_name = (char_u *)sourcing_name;
   sourcing_lnum = lnum;               // prepare for emsg()
-  sourcing_name = (char_u *)"modelines";
+  sourcing_name = "modelines";
 
   end = false;
   while (end == false) {
@@ -5259,7 +5259,7 @@ static int chk_modeline(linenr_T lnum, int flags)
   }
 
   sourcing_lnum = save_sourcing_lnum;
-  sourcing_name = save_sourcing_name;
+  sourcing_name = (char *)save_sourcing_name;
 
   xfree(linecopy);
 
@@ -5594,7 +5594,7 @@ bool buf_contents_changed(buf_T *buf)
   aucmd_prepbuf(&aco, newbuf);
 
   if (ml_open(curbuf) == OK
-      && readfile(buf->b_ffname, buf->b_fname,
+      && readfile((char *)buf->b_ffname, (char *)buf->b_fname,
                   (linenr_T)0, (linenr_T)0, (linenr_T)MAXLNUM,
                   &ea, READ_NEW | READ_DUMMY, false) == OK) {
     // compare the two files line by line
diff --git a/src/nvim/change.c b/src/nvim/change.c
index 767e6d3837..b15e90e0bc 100644
--- a/src/nvim/change.c
+++ b/src/nvim/change.c
@@ -557,7 +557,7 @@ void ins_char(int c)
   if (buf[0] == 0) {
     buf[0] = '\n';
   }
-  ins_char_bytes(buf, n);
+  ins_char_bytes((char_u *)buf, n);
 }
 
 void ins_char_bytes(char_u *buf, size_t charlen)
diff --git a/src/nvim/charset.c b/src/nvim/charset.c
index 5b93973f54..4f6033cbfa 100644
--- a/src/nvim/charset.c
+++ b/src/nvim/charset.c
@@ -1187,16 +1187,16 @@ intptr_t getwhitecols(const char_u *p)
 /// @param[in]  q  String to skip digits in.
 ///
 /// @return Pointer to the character after the skipped digits.
-char_u *skipdigits(const char_u *q)
+char *skipdigits(const char *q)
   FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_NONNULL_ALL
   FUNC_ATTR_NONNULL_RET
 {
-  const char_u *p = q;
+  const char *p = q;
   while (ascii_isdigit(*p)) {
     // skip to next non-digit
     p++;
   }
-  return (char_u *)p;
+  return (char *)p;
 }
 
 /// skip over binary digits
diff --git a/src/nvim/context.c b/src/nvim/context.c
index 0e0d8fdfde..db26667009 100644
--- a/src/nvim/context.c
+++ b/src/nvim/context.c
@@ -129,8 +129,8 @@ bool ctx_restore(Context *ctx, const int flags)
     free_ctx = true;
   }
 
-  char_u *op_shada;
-  get_option_value("shada", NULL, (char **)&op_shada, OPT_GLOBAL);
+  char *op_shada;
+  get_option_value("shada", NULL, &op_shada, OPT_GLOBAL);
   set_option_value("shada", 0L, "!,'100,%", OPT_GLOBAL);
 
   if (flags & kCtxRegs) {
@@ -157,7 +157,7 @@ bool ctx_restore(Context *ctx, const int flags)
     ctx_free(ctx);
   }
 
-  set_option_value("shada", 0L, (char *)op_shada, OPT_GLOBAL);
+  set_option_value("shada", 0L, op_shada, OPT_GLOBAL);
   xfree(op_shada);
 
   return true;
diff --git a/src/nvim/debugger.c b/src/nvim/debugger.c
index 6fab70d4c2..0f76c3e884 100644
--- a/src/nvim/debugger.c
+++ b/src/nvim/debugger.c
@@ -60,7 +60,7 @@ void do_debug(char_u *cmd)
   int save_ignore_script = 0;
   int n;
   char_u *cmdline = NULL;
-  char_u *p;
+  char *p;
   char *tail = NULL;
   static int last_cmd = 0;
 #define CMD_CONT        1
@@ -141,7 +141,7 @@ void do_debug(char_u *cmd)
       // If this is a debug command, set "last_cmd".
       // If not, reset "last_cmd".
       // For a blank line use previous command.
-      p = (char_u *)skipwhite((char *)cmdline);
+      p = skipwhite((char *)cmdline);
       if (*p != NUL) {
         switch (*p) {
         case 'c':
@@ -200,7 +200,7 @@ void do_debug(char_u *cmd)
         if (last_cmd != 0) {
           // Check that the tail matches.
           p++;
-          while (*p != NUL && *p == (char_u)(*tail)) {
+          while (*p != NUL && *p == *tail) {
             p++;
             tail++;
           }
@@ -242,8 +242,8 @@ void do_debug(char_u *cmd)
           if (*p == NUL) {
             do_showbacktrace(cmd);
           } else {
-            p = (char_u *)skipwhite((char *)p);
-            do_setdebugtracelevel(p);
+            p = skipwhite(p);
+            do_setdebugtracelevel((char_u *)p);
           }
           continue;
         case CMD_UP:
diff --git a/src/nvim/diff.c b/src/nvim/diff.c
index 55992f3fae..dcc9b51431 100644
--- a/src/nvim/diff.c
+++ b/src/nvim/diff.c
@@ -744,7 +744,7 @@ static int diff_write_buffer(buf_T *buf, diffin_T *din)
     for (char_u *s = ml_get_buf(buf, lnum, false); *s != NUL;) {
       if (diff_flags & DIFF_ICASE) {
         int c;
-        char_u cbuf[MB_MAXBYTES + 1];
+        char cbuf[MB_MAXBYTES + 1];
 
         if (*s == NL) {
           c = NUL;
@@ -794,7 +794,7 @@ static int diff_write(buf_T *buf, diffin_T *din)
   // Writing the buffer is an implementation detail of performing the diff,
   // so it shouldn't update the '[ and '] marks.
   cmdmod.lockmarks = true;
-  int r = buf_write(buf, din->din_fname, NULL,
+  int r = buf_write(buf, (char *)din->din_fname, NULL,
                     (linenr_T)1, buf->b_ml.ml_line_count,
                     NULL, false, false, false, true);
   cmdmod.lockmarks = save_lockmarks;
@@ -1178,7 +1178,7 @@ void ex_diffpatch(exarg_T *eap)
   }
 
   // Write the current buffer to "tmp_orig".
-  if (buf_write(curbuf, tmp_orig, NULL,
+  if (buf_write(curbuf, (char *)tmp_orig, NULL,
                 (linenr_T)1, curbuf->b_ml.ml_line_count,
                 NULL, false, false, false, true) == FAIL) {
     goto theend;
@@ -1982,8 +1982,8 @@ static int diff_cmp(char_u *s1, char_u *s2)
     return mb_stricmp((const char *)s1, (const char *)s2);
   }
 
-  char_u *p1 = s1;
-  char_u *p2 = s2;
+  char *p1 = (char *)s1;
+  char *p2 = (char *)s2;
 
   // Ignore white space changes and possibly ignore case.
   while (*p1 != NUL && *p2 != NUL) {
@@ -1991,11 +1991,11 @@ static int diff_cmp(char_u *s1, char_u *s2)
          && ascii_iswhite(*p1) && ascii_iswhite(*p2))
         || ((diff_flags & DIFF_IWHITEALL)
             && (ascii_iswhite(*p1) || ascii_iswhite(*p2)))) {
-      p1 = (char_u *)skipwhite((char *)p1);
-      p2 = (char_u *)skipwhite((char *)p2);
+      p1 = skipwhite(p1);
+      p2 = skipwhite(p2);
     } else {
       int l;
-      if (!diff_equal_char(p1, p2, &l)) {
+      if (!diff_equal_char((char_u *)p1, (char_u *)p2, &l)) {
         break;
       }
       p1 += l;
@@ -2004,8 +2004,8 @@ static int diff_cmp(char_u *s1, char_u *s2)
   }
 
   // Ignore trailing white space.
-  p1 = (char_u *)skipwhite((char *)p1);
-  p2 = (char_u *)skipwhite((char *)p2);
+  p1 = skipwhite(p1);
+  p2 = skipwhite(p2);
 
   if ((*p1 != NUL) || (*p2 != NUL)) {
     return 1;
diff --git a/src/nvim/digraph.c b/src/nvim/digraph.c
index da96379700..43ea32fc09 100644
--- a/src/nvim/digraph.c
+++ b/src/nvim/digraph.c
@@ -2087,7 +2087,7 @@ void ex_loadkeymap(exarg_T *eap)
 
   // Get each line of the sourced file, break at the end.
   for (;;) {
-    char_u *line = eap->getline(0, eap->cookie, 0, true);
+    char *line = eap->getline(0, eap->cookie, 0, true);
 
     if (line == NULL) {
       break;
diff --git a/src/nvim/edit.c b/src/nvim/edit.c
index 20bbc23ac4..c2e61271c7 100644
--- a/src/nvim/edit.c
+++ b/src/nvim/edit.c
@@ -1325,14 +1325,14 @@ normalchar:
 
     if (!p_paste) {
       // Trigger InsertCharPre.
-      char_u *str = do_insert_char_pre(s->c);
-      char_u *p;
+      char *str = (char *)do_insert_char_pre(s->c);
+      char *p;
 
       if (str != NULL) {
         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((char *)p);
+            s->c = utf_ptr2char(p);
             if (s->c == CAR || s->c == K_KENTER || s->c == NL) {
               ins_eol(s->c);
             } else {
@@ -3505,11 +3505,11 @@ static void ins_compl_addleader(int c)
     return;
   }
   if ((cc = utf_char2len(c)) > 1) {
-    char_u buf[MB_MAXBYTES + 1];
+    char buf[MB_MAXBYTES + 1];
 
     utf_char2bytes(c, (char *)buf);
     buf[cc] = NUL;
-    ins_char_bytes(buf, (size_t)cc);
+    ins_char_bytes((char_u *)buf, (size_t)cc);
   } else {
     ins_char(c);
   }
@@ -5939,11 +5939,11 @@ void insertchar(int c, int flags, int second_indent)
     int cc;
 
     if ((cc = utf_char2len(c)) > 1) {
-      char_u buf[MB_MAXBYTES + 1];
+      char buf[MB_MAXBYTES + 1];
 
       utf_char2bytes(c, (char *)buf);
       buf[cc] = NUL;
-      ins_char_bytes(buf, (size_t)cc);
+      ins_char_bytes((char_u *)buf, (size_t)cc);
       AppendCharToRedobuff(c);
     } else {
       ins_char(c);
@@ -6840,7 +6840,7 @@ char_u *add_char2buf(int c, char_u *s)
   char_u temp[MB_MAXBYTES + 1];
   const int len = utf_char2bytes(c, (char *)temp);
   for (int i = 0; i < len; i++) {
-    c = temp[i];
+    c = (uint8_t)temp[i];
     // Need to escape K_SPECIAL like in the typeahead buffer.
     if (c == K_SPECIAL) {
       *s++ = K_SPECIAL;
@@ -9460,7 +9460,7 @@ static char_u *do_insert_char_pre(int c)
     // character.  Only use it when changed, otherwise continue with the
     // original character to avoid breaking autoindent.
     if (STRCMP(buf, get_vim_var_str(VV_CHAR)) != 0) {
-      res = vim_strsave(get_vim_var_str(VV_CHAR));
+      res = vim_strsave((char_u *)get_vim_var_str(VV_CHAR));
     }
   }
 
diff --git a/src/nvim/eval.c b/src/nvim/eval.c<