refactor: replace char_u with char

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

33 files changed, 513 insertions, 512 deletions

diff --git a/src/nvim/api/private/helpers.c b/src/nvim/api/private/helpers.c
index b7cd0c82fb..ca8ad16cbf 100644
--- a/src/nvim/api/private/helpers.c
+++ b/src/nvim/api/private/helpers.c
@@ -505,7 +505,7 @@ String buf_get_text(buf_T *buf, int64_t lnum, int64_t start_col, int64_t end_col
     return rv;
   }
 
-  return cstrn_as_string((char *)&bufstr[start_col], (size_t)(end_col - start_col));
+  return cstrn_as_string(&bufstr[start_col], (size_t)(end_col - start_col));
 }
 
 void api_free_string(String value)
diff --git a/src/nvim/charset.c b/src/nvim/charset.c
index 82a4698058..1f9b8f9a65 100644
--- a/src/nvim/charset.c
+++ b/src/nvim/charset.c
@@ -274,7 +274,7 @@ int buf_init_chartab(buf_T *buf, int global)
 /// @param bufsize
 void trans_characters(char *buf, int bufsize)
 {
-  char_u *trs;                 // translated character
+  char *trs;                   // translated character
   int len = (int)strlen(buf);  // length of string needing translation
   int room = bufsize - len;    // room in buffer after string
 
@@ -284,8 +284,8 @@ void trans_characters(char *buf, int bufsize)
     if ((trs_len = utfc_ptr2len(buf)) > 1) {
       len -= trs_len;
     } else {
-      trs = transchar_byte((uint8_t)(*buf));
-      trs_len = (int)STRLEN(trs);
+      trs = (char *)transchar_byte((uint8_t)(*buf));
+      trs_len = (int)strlen(trs);
 
       if (trs_len > 1) {
         room -= trs_len - 1;
diff --git a/src/nvim/cmdexpand.c b/src/nvim/cmdexpand.c
index 39865d7508..79ffd7552d 100644
--- a/src/nvim/cmdexpand.c
+++ b/src/nvim/cmdexpand.c
@@ -180,7 +180,7 @@ int nextwild(expand_T *xp, int type, int options, bool escape)
   CmdlineInfo *const ccline = get_cmdline_info();
   int i, j;
   char_u *p1;
-  char_u *p2;
+  char *p2;
   int difflen;
 
   if (xp->xp_numfiles == -1) {
@@ -210,7 +210,7 @@ int nextwild(expand_T *xp, int type, int options, bool escape)
 
   if (type == WILD_NEXT || type == WILD_PREV || type == WILD_PUM_WANT) {
     // Get next/previous match for a previous expanded pattern.
-    p2 = (char_u *)ExpandOne(xp, NULL, NULL, 0, type);
+    p2 = ExpandOne(xp, NULL, NULL, 0, type);
   } else {
     // Translate string into pattern and expand it.
     p1 = (char_u *)addstar(xp->xp_pattern, xp->xp_pattern_len, xp->xp_context);
@@ -220,8 +220,8 @@ int nextwild(expand_T *xp, int type, int options, bool escape)
                              | WILD_SILENT
                              | (escape ? WILD_ESCAPE : 0)
                              | (p_wic ? WILD_ICASE : 0));
-    p2 = (char_u *)ExpandOne(xp, (char *)p1, xstrnsave(&ccline->cmdbuff[i], xp->xp_pattern_len),
-                             use_options, type);
+    p2 = ExpandOne(xp, (char *)p1, xstrnsave(&ccline->cmdbuff[i], xp->xp_pattern_len),
+                   use_options, type);
     xfree(p1);
 
     // xp->xp_pattern might have been modified by ExpandOne (for example,
@@ -237,14 +237,14 @@ int nextwild(expand_T *xp, int type, int options, bool escape)
           break;
         }
       }
-      if ((int)STRLEN(p2) < j) {
+      if ((int)strlen(p2) < j) {
         XFREE_CLEAR(p2);
       }
     }
   }
 
   if (p2 != NULL && !got_int) {
-    difflen = (int)STRLEN(p2) - (int)(xp->xp_pattern_len);
+    difflen = (int)strlen(p2) - (int)(xp->xp_pattern_len);
     if (ccline->cmdlen + difflen + 4 > ccline->cmdbufflen) {
       realloc_cmdbuff(ccline->cmdlen + difflen + 4);
       xp->xp_pattern = ccline->cmdbuff + i;
@@ -253,7 +253,7 @@ int nextwild(expand_T *xp, int type, int options, bool escape)
     memmove(&ccline->cmdbuff[ccline->cmdpos + difflen],
             &ccline->cmdbuff[ccline->cmdpos],
             (size_t)ccline->cmdlen - (size_t)ccline->cmdpos + 1);
-    memmove(&ccline->cmdbuff[i], p2, STRLEN(p2));
+    memmove(&ccline->cmdbuff[i], p2, strlen(p2));
     ccline->cmdlen += difflen;
     ccline->cmdpos += difflen;
   }
@@ -588,7 +588,7 @@ static char *ExpandOne_start(int mode, expand_T *xp, char *str, int options)
   char *ss = NULL;
 
   // Do the expansion.
-  if (ExpandFromContext(xp, (char_u *)str, &xp->xp_numfiles, &xp->xp_files, options) == FAIL) {
+  if (ExpandFromContext(xp, str, &xp->xp_numfiles, &xp->xp_files, options) == FAIL) {
 #ifdef FNAME_ILLEGAL
     // Illegal file name has been silently skipped.  But when there
     // are wildcards, the real problem is that there was no match,
@@ -1600,13 +1600,13 @@ static const char *set_context_by_cmdname(const char *cmd, cmdidx_T cmdidx, cons
   case CMD_doautoall:
     return (const char *)set_context_in_autocmd(xp, (char *)arg, true);
   case CMD_set:
-    set_context_in_set_cmd(xp, (char_u *)arg, 0);
+    set_context_in_set_cmd(xp, (char *)arg, 0);
     break;
   case CMD_setglobal:
-    set_context_in_set_cmd(xp, (char_u *)arg, OPT_GLOBAL);
+    set_context_in_set_cmd(xp, (char *)arg, OPT_GLOBAL);
     break;
   case CMD_setlocal:
-    set_context_in_set_cmd(xp, (char_u *)arg, OPT_LOCAL);
+    set_context_in_set_cmd(xp, (char *)arg, OPT_LOCAL);
     break;
   case CMD_tag:
   case CMD_stag:
@@ -2163,7 +2163,7 @@ int expand_cmdline(expand_T *xp, const char_u *str, int col, int *matchcount, ch
   }
 
   // find all files that match the description
-  if (ExpandFromContext(xp, file_str, matchcount, matches, options) == FAIL) {
+  if (ExpandFromContext(xp, (char *)file_str, matchcount, matches, options) == FAIL) {
     *matchcount = 0;
     *matches = NULL;
   }
@@ -2352,7 +2352,7 @@ static int ExpandOther(expand_T *xp, regmatch_T *rmp, int *num_file, char ***fil
 /// Do the expansion based on xp->xp_context and "pat".
 ///
 /// @param options  WILD_ flags
-static int ExpandFromContext(expand_T *xp, char_u *pat, int *num_file, char ***file, int options)
+static int ExpandFromContext(expand_T *xp, char *pat, int *num_file, char ***file, int options)
 {
   regmatch_T regmatch;
   int ret;
@@ -2381,7 +2381,7 @@ static int ExpandFromContext(expand_T *xp, char_u *pat, int *num_file, char ***f
   if (xp->xp_context == EXPAND_FILES
       || xp->xp_context == EXPAND_DIRECTORIES
       || xp->xp_context == EXPAND_FILES_IN_PATH) {
-    return expand_files_and_dirs(xp, (char *)pat, file, num_file, flags, options);
+    return expand_files_and_dirs(xp, pat, file, num_file, flags, options);
   }
 
   *file = NULL;
@@ -2389,7 +2389,7 @@ static int ExpandFromContext(expand_T *xp, char_u *pat, int *num_file, char ***f
   if (xp->xp_context == EXPAND_HELP) {
     // With an empty argument we would get all the help tags, which is
     // very slow.  Get matches for "help" instead.
-    if (find_help_tags(*pat == NUL ? "help" : (char *)pat,
+    if (find_help_tags(*pat == NUL ? "help" : pat,
                        num_file, file, false) == OK) {
       cleanup_help_tags(*num_file, *file);
       return OK;
@@ -2399,7 +2399,7 @@ static int ExpandFromContext(expand_T *xp, char_u *pat, int *num_file, char ***f
 
   if (xp->xp_context == EXPAND_SHELLCMD) {
     *file = NULL;
-    expand_shellcmd((char *)pat, num_file, file, flags);
+    expand_shellcmd(pat, num_file, file, flags);
     return OK;
   }
   if (xp->xp_context == EXPAND_OLD_SETTING) {
@@ -2407,30 +2407,30 @@ static int ExpandFromContext(expand_T *xp, char_u *pat, int *num_file, char ***f
     return OK;
   }
   if (xp->xp_context == EXPAND_BUFFERS) {
-    return ExpandBufnames((char *)pat, num_file, file, options);
+    return ExpandBufnames(pat, num_file, file, options);
   }
   if (xp->xp_context == EXPAND_DIFF_BUFFERS) {
-    return ExpandBufnames((char *)pat, num_file, file, options | BUF_DIFF_FILTER);
+    return ExpandBufnames(pat, num_file, file, options | BUF_DIFF_FILTER);
   }
   if (xp->xp_context == EXPAND_TAGS
       || xp->xp_context == EXPAND_TAGS_LISTFILES) {
-    return expand_tags(xp->xp_context == EXPAND_TAGS, pat, num_file, file);
+    return expand_tags(xp->xp_context == EXPAND_TAGS, (char_u *)pat, num_file, file);
   }
   if (xp->xp_context == EXPAND_COLORS) {
     char *directories[] = { "colors", NULL };
-    return ExpandRTDir((char *)pat, DIP_START + DIP_OPT + DIP_LUA, num_file, file, directories);
+    return ExpandRTDir(pat, DIP_START + DIP_OPT + DIP_LUA, num_file, file, directories);
   }
   if (xp->xp_context == EXPAND_COMPILER) {
     char *directories[] = { "compiler", NULL };
-    return ExpandRTDir((char *)pat, DIP_LUA, num_file, file, directories);
+    return ExpandRTDir(pat, DIP_LUA, num_file, file, directories);
   }
   if (xp->xp_context == EXPAND_OWNSYNTAX) {
     char *directories[] = { "syntax", NULL };
-    return ExpandRTDir((char *)pat, 0, num_file, file, directories);
+    return ExpandRTDir(pat, 0, num_file, file, directories);
   }
   if (xp->xp_context == EXPAND_FILETYPE) {
     char *directories[] = { "syntax", "indent", "ftplugin", NULL };
-    return ExpandRTDir((char *)pat, DIP_LUA, num_file, file, directories);
+    return ExpandRTDir(pat, DIP_LUA, num_file, file, directories);
   }
   if (xp->xp_context == EXPAND_USER_LIST) {
     return ExpandUserList(xp, num_file, file);
@@ -2439,32 +2439,32 @@ static int ExpandFromContext(expand_T *xp, char_u *pat, int *num_file, char ***f
     return ExpandUserLua(xp, num_file, file);
   }
   if (xp->xp_context == EXPAND_PACKADD) {
-    return ExpandPackAddDir((char *)pat, num_file, file);
+    return ExpandPackAddDir(pat, num_file, file);
   }
 
   // When expanding a function name starting with s:, match the <SNR>nr_
   // prefix.
   char *tofree = NULL;
   if (xp->xp_context == EXPAND_USER_FUNC && STRNCMP(pat, "^s:", 3) == 0) {
-    const size_t len = STRLEN(pat) + 20;
+    const size_t len = strlen(pat) + 20;
 
     tofree = xmalloc(len);
     snprintf(tofree, len, "^<SNR>\\d\\+_%s", pat + 3);
-    pat = (char_u *)tofree;
+    pat = tofree;
   }
 
   if (xp->xp_context == EXPAND_LUA) {
     ILOG("PAT %s", pat);
-    return nlua_expand_pat(xp, (char *)pat, num_file, file);
+    return nlua_expand_pat(xp, pat, num_file, file);
   }
 
-  regmatch.regprog = vim_regcomp((char *)pat, p_magic ? RE_MAGIC : 0);
+  regmatch.regprog = vim_regcomp(pat, p_magic ? RE_MAGIC : 0);
   if (regmatch.regprog == NULL) {
     return FAIL;
   }
 
   // set ignore-case according to p_ic, p_scs and pat
-  regmatch.rm_ic = ignorecase(pat);
+  regmatch.rm_ic = ignorecase((char_u *)pat);
 
   if (xp->xp_context == EXPAND_SETTINGS
       || xp->xp_context == EXPAND_BOOL_SETTINGS) {
@@ -2651,19 +2651,19 @@ static void expand_shellcmd(char *filepat, int *num_file, char ***file, int flag
       ga_grow(&ga, *num_file);
       {
         for (i = 0; i < *num_file; i++) {
-          char_u *name = (char_u *)(*file)[i];
+          char *name = (*file)[i];
 
-          if (STRLEN(name) > l) {
+          if (strlen(name) > l) {
             // Check if this name was already found.
-            hash_T hash = hash_hash(name + l);
+            hash_T hash = hash_hash((char_u *)name + l);
             hashitem_T *hi =
               hash_lookup(&found_ht, (const char *)(name + l),
-                          STRLEN(name + l), hash);
+                          strlen(name + l), hash);
             if (HASHITEM_EMPTY(hi)) {
               // Remove the path that was prepended.
               STRMOVE(name, name + l);
-              ((char_u **)ga.ga_data)[ga.ga_len++] = name;
-              hash_add_item(&found_ht, hi, name, hash);
+              ((char **)ga.ga_data)[ga.ga_len++] = name;
+              hash_add_item(&found_ht, hi, (char_u *)name, hash);
               name = NULL;
             }
           }
@@ -2834,14 +2834,14 @@ void globpath(char *path, char *file, garray_T *ga, int expand_options)
   ExpandInit(&xpc);
   xpc.xp_context = EXPAND_FILES;
 
-  char_u *buf = xmalloc(MAXPATHL);
+  char *buf = xmalloc(MAXPATHL);
 
   // Loop over all entries in {path}.
   while (*path != NUL) {
     // Copy one item of the path to buf[] and concatenate the file name.
-    copy_option_part(&path, (char *)buf, MAXPATHL, ",");
-    if (STRLEN(buf) + strlen(file) + 2 < MAXPATHL) {
-      add_pathsep((char *)buf);
+    copy_option_part(&path, buf, MAXPATHL, ",");
+    if (strlen(buf) + strlen(file) + 2 < MAXPATHL) {
+      add_pathsep(buf);
       STRCAT(buf, file);  // NOLINT
 
       char **p;
@@ -2849,7 +2849,7 @@ void globpath(char *path, char *file, garray_T *ga, int expand_options)
       (void)ExpandFromContext(&xpc, buf, &num_p, &p,
                               WILD_SILENT | expand_options);
       if (num_p > 0) {
-        ExpandEscape(&xpc, buf, num_p, p, WILD_SILENT | expand_options);
+        ExpandEscape(&xpc, (char_u *)buf, num_p, p, WILD_SILENT | expand_options);
 
         // Concatenate new results to previous ones.
         ga_grow(ga, num_p);
diff --git a/src/nvim/cursor.c b/src/nvim/cursor.c
index 811f397cb8..84a2cf83ac 100644
--- a/src/nvim/cursor.c
+++ b/src/nvim/cursor.c
@@ -108,14 +108,14 @@ static int coladvance2(pos_T *pos, bool addspaces, bool finetune, colnr_T wcol_a
                  || (VIsual_active && *p_sel != 'o')
                  || ((get_ve_flags() & VE_ONEMORE) && wcol < MAXCOL);
 
-  char_u *line = (char_u *)ml_get_buf(curbuf, pos->lnum, false);
+  char *line = ml_get_buf(curbuf, pos->lnum, false);
 
   if (wcol >= MAXCOL) {
-    idx = (int)STRLEN(line) - 1 + one_more;
+    idx = (int)strlen(line) - 1 + one_more;
     col = wcol;
 
     if ((addspaces || finetune) && !VIsual_active) {
-      curwin->w_curswant = linetabsize(line) + one_more;
+      curwin->w_curswant = linetabsize((char_u *)line) + one_more;
       if (curwin->w_curswant > 0) {
         curwin->w_curswant--;
       }
@@ -129,7 +129,7 @@ static int coladvance2(pos_T *pos, bool addspaces, bool finetune, colnr_T wcol_a
         && curwin->w_width_inner != 0
         && wcol >= (colnr_T)width
         && width > 0) {
-      csize = linetabsize(line);
+      csize = linetabsize((char_u *)line);
       if (csize > 0) {
         csize--;
       }
@@ -145,7 +145,7 @@ static int coladvance2(pos_T *pos, bool addspaces, bool finetune, colnr_T wcol_a
     }
 
     chartabsize_T cts;
-    init_chartabsize_arg(&cts, curwin, pos->lnum, 0, (char *)line, (char *)line);
+    init_chartabsize_arg(&cts, curwin, pos->lnum, 0, line, line);
     while (cts.cts_vcol <= wcol && *cts.cts_ptr != NUL) {
       // Count a tab for what it's worth (if list mode not on)
       csize = win_lbr_chartabsize(&cts, &head);
@@ -153,7 +153,7 @@ static int coladvance2(pos_T *pos, bool addspaces, bool finetune, colnr_T wcol_a
       cts.cts_vcol += csize;
     }
     col = cts.cts_vcol;
-    idx = (int)(cts.cts_ptr - (char *)line);
+    idx = (int)(cts.cts_ptr - line);
     clear_chartabsize_arg(&cts);
 
     // Handle all the special cases.  The virtual_active() check
@@ -188,7 +188,7 @@ static int coladvance2(pos_T *pos, bool addspaces, bool finetune, colnr_T wcol_a
         col = wcol;
       } else {
         // Break a tab
-        int linelen = (int)STRLEN(line);
+        int linelen = (int)strlen(line);
         int correct = wcol - col - csize + 1;             // negative!!
         char_u *newline;
 
@@ -315,8 +315,8 @@ void check_pos(buf_T *buf, pos_T *pos)
   }
 
   if (pos->col > 0) {
-    char_u *line = (char_u *)ml_get_buf(buf, pos->lnum, false);
-    colnr_T len = (colnr_T)STRLEN(line);
+    char *line = ml_get_buf(buf, pos->lnum, false);
+    colnr_T len = (colnr_T)strlen(line);
     if (pos->col > len) {
       pos->col = len;
     }
diff --git a/src/nvim/diff.c b/src/nvim/diff.c
index 4b71142c11..121b98d047 100644
--- a/src/nvim/diff.c
+++ b/src/nvim/diff.c
@@ -1043,7 +1043,7 @@ static int check_external_diff(diffio_T *diffio)
           for (;;) {
             // For normal diff there must be a line that contains
             // "1c1".  For unified diff "@@ -1 +1 @@".
-            if (vim_fgets((char_u *)linebuf, LBUFLEN, fd)) {
+            if (vim_fgets(linebuf, LBUFLEN, fd)) {
               break;
             }
 
@@ -1218,9 +1218,9 @@ void ex_diffpatch(exarg_T *eap)
   esc_name =
     (char *)vim_strsave_shellescape((char_u *)(fullname != NULL ? fullname : eap->arg), true, true);
 #else
-  esc_name = vim_strsave_shellescape(eap->arg, true, true);
+  esc_name = (char *)vim_strsave_shellescape(eap->arg, true, true);
 #endif
-  size_t buflen = STRLEN(tmp_orig) + STRLEN(esc_name) + STRLEN(tmp_new) + 16;
+  size_t buflen = strlen(tmp_orig) + strlen(esc_name) + strlen(tmp_new) + 16;
   buf = xmalloc(buflen);
 
 #ifdef UNIX
@@ -1557,7 +1557,7 @@ static bool extract_hunk(FILE *fd, diffhunk_T *hunk, diffstyle_T *diffstyle)
 {
   for (;;) {
     char line[LBUFLEN];  // only need to hold the diff line
-    if (vim_fgets((char_u *)line, LBUFLEN, fd)) {
+    if (vim_fgets(line, LBUFLEN, fd)) {
       return true;  // end of file
     }
 
@@ -1577,9 +1577,9 @@ static bool extract_hunk(FILE *fd, diffhunk_T *hunk, diffstyle_T *diffstyle)
       } else if ((STRNCMP(line, "@@ ", 3) == 0)) {
         *diffstyle = DIFF_UNIFIED;
       } else if ((STRNCMP(line, "--- ", 4) == 0)  // -V501
-                 && (vim_fgets((char_u *)line, LBUFLEN, fd) == 0)  // -V501
+                 && (vim_fgets(line, LBUFLEN, fd) == 0)  // -V501
                  && (STRNCMP(line, "+++ ", 4) == 0)
-                 && (vim_fgets((char_u *)line, LBUFLEN, fd) == 0)  // -V501
+                 && (vim_fgets(line, LBUFLEN, fd) == 0)  // -V501
                  && (STRNCMP(line, "@@ ", 3) == 0)) {
         *diffstyle = DIFF_UNIFIED;
       } else {
diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index 12568ec965..e49b0fd14c 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -2343,13 +2343,13 @@ static void findfilendir(typval_T *argvars, typval_T *rettv, int find_what)
       if (rettv->v_type == VAR_STRING || rettv->v_type == VAR_LIST) {
         xfree(fresult);
       }
-      fresult = find_file_in_path_option(first ? (char_u *)fname : NULL,
-                                         first ? strlen(fname) : 0,
-                                         0, first, path,
-                                         find_what, (char_u *)curbuf->b_ffname,
-                                         (find_what == FINDFILE_DIR
-                                          ? (char_u *)""
-                                          : (char_u *)curbuf->b_p_sua));
+      fresult = (char_u *)find_file_in_path_option(first ? (char *)fname : NULL,
+                                                   first ? strlen(fname) : 0,
+                                                   0, first, (char *)path,
+                                                   find_what, curbuf->b_ffname,
+                                                   (find_what == FINDFILE_DIR
+                                                    ? ""
+                                                    : curbuf->b_p_sua));
       first = false;
 
       if (fresult != NULL && rettv->v_type == VAR_LIST) {
diff --git a/src/nvim/ex_docmd.c b/src/nvim/ex_docmd.c
index 0733bcf683..a2bd6fb43f 100644
--- a/src/nvim/ex_docmd.c
+++ b/src/nvim/ex_docmd.c
@@ -3378,7 +3378,7 @@ static linenr_T get_address(exarg_T *eap, char **ptr, cmd_addr_T addr_type, int
         }
         searchcmdlen = 0;
         flags = silent ? 0 : SEARCH_HIS | SEARCH_MSG;
-        if (!do_search(NULL, c, c, (char_u *)cmd, 1L, flags, NULL)) {
+        if (!do_search(NULL, c, c, cmd, 1L, flags, NULL)) {
           curwin->w_cursor = pos;
           cmd = NULL;
           goto error;
@@ -3831,7 +3831,7 @@ int expand_filename(exarg_T *eap, char **cmdlinep, char **errormsgp)
       // if there are still wildcards present.
       if (vim_strchr(eap->arg, '$') != NULL
           || vim_strchr(eap->arg, '~') != NULL) {
-        expand_env_esc((char_u *)eap->arg, (char_u *)NameBuff, MAXPATHL, true, true, NULL);
+        expand_env_esc(eap->arg, NameBuff, MAXPATHL, true, true, NULL);
         has_wildcards = path_has_wildcard(NameBuff);
         p = (char *)NameBuff;
       } else {
@@ -5541,7 +5541,7 @@ bool changedir_func(char *new_dir, CdScope scope)
   bool dir_differs = pdir == NULL || pathcmp(pdir, new_dir, -1) != 0;
   if (dir_differs) {
     do_autocmd_dirchanged(new_dir, scope, kCdCauseManual, true);
-    if (vim_chdir((char_u *)new_dir) != 0) {
+    if (vim_chdir(new_dir) != 0) {
       emsg(_(e_failed));
       xfree(pdir);
       return false;
diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index 89d295e1a8..fc9559172f 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -439,7 +439,7 @@ static void may_do_incsearch_highlighting(int firstc, long count, incsearch_stat
       .sa_tm = &tm,
     };
     found = do_search(NULL, firstc == ':' ? '/' : firstc, search_delim,
-                      (char_u *)ccline.cmdbuff + skiplen, count,
+                      ccline.cmdbuff + skiplen, count,
                       search_flags, &sia);
     ccline.cmdbuff[skiplen + patlen] = next_char;
     emsg_off--;
diff --git a/src/nvim/file_search.c b/src/nvim/file_search.c
index 1d891799a5..36d58923b0 100644
--- a/src/nvim/file_search.c
+++ b/src/nvim/file_search.c
@@ -82,8 +82,8 @@ typedef struct ff_stack {
 
   // the fix part (no wildcards) and the part containing the wildcards
   // of the search path
-  char_u *ffs_fix_path;
-  char_u *ffs_wc_path;
+  char *ffs_fix_path;
+  char *ffs_wc_path;
 
   // files/dirs found in the above directory, matched by the first wildcard
   // of wc_part
@@ -511,7 +511,7 @@ char_u *vim_findfile_stopdir(char_u *buf)
   while (*r_ptr != NUL && *r_ptr != ';') {
     if (r_ptr[0] == '\\' && r_ptr[1] == ';') {
       // Overwrite the escape char,
-      // use STRLEN(r_ptr) to move the trailing '\0'.
+      // use strlen(r_ptr) to move the trailing '\0'.
       STRMOVE(r_ptr, r_ptr + 1);
       r_ptr++;
     }
@@ -553,12 +553,12 @@ void vim_findfile_cleanup(void *ctx)
 ///          NULL if nothing found.
 char_u *vim_findfile(void *search_ctx_arg)
 {
-  char_u *file_path;
-  char_u *rest_of_wildcards;
+  char *file_path;
+  char *rest_of_wildcards;
   char_u *path_end = NULL;
   ff_stack_T *stackp = NULL;
   size_t len;
-  char_u *p;
+  char *p;
   char *suf;
   ff_search_ctx_T *search_ctx;
 
@@ -612,7 +612,7 @@ char_u *vim_findfile(void *search_ctx_arg)
       // first time (hence stackp->ff_filearray == NULL)
       if (stackp->ffs_filearray == NULL
           && ff_check_visited(&search_ctx->ffsc_dir_visited_list->ffvl_visited_list,
-                              (char *)stackp->ffs_fix_path, (char *)stackp->ffs_wc_path) == FAIL) {
+                              stackp->ffs_fix_path, stackp->ffs_wc_path) == FAIL) {
 #ifdef FF_VERBOSE
         if (p_verbose >= 5) {
           verbose_enter_scroll();
@@ -650,37 +650,37 @@ char_u *vim_findfile(void *search_ctx_arg)
         char *dirptrs[2];
 
         // we use filepath to build the path expand_wildcards() should expand.
-        dirptrs[0] = (char *)file_path;
+        dirptrs[0] = file_path;
         dirptrs[1] = NULL;
 
         // if we have a start dir copy it in
-        if (!vim_isAbsName(stackp->ffs_fix_path)
+        if (!vim_isAbsName((char_u *)stackp->ffs_fix_path)
             && search_ctx->ffsc_start_dir) {
           if (strlen(search_ctx->ffsc_start_dir) + 1 >= MAXPATHL) {
             ff_free_stack_element(stackp);
             goto fail;
           }
           STRCPY(file_path, search_ctx->ffsc_start_dir);
-          if (!add_pathsep((char *)file_path)) {
+          if (!add_pathsep(file_path)) {
             ff_free_stack_element(stackp);
             goto fail;
           }
         }
 
         // append the fix part of the search path
-        if (STRLEN(file_path) + STRLEN(stackp->ffs_fix_path) + 1 >= MAXPATHL) {
+        if (strlen(file_path) + strlen(stackp->ffs_fix_path) + 1 >= MAXPATHL) {
           ff_free_stack_element(stackp);
           goto fail;
         }
         STRCAT(file_path, stackp->ffs_fix_path);
-        if (!add_pathsep((char *)file_path)) {
+        if (!add_pathsep(file_path)) {
           ff_free_stack_element(stackp);
           goto fail;
         }
 
         rest_of_wildcards = stackp->ffs_wc_path;
         if (*rest_of_wildcards != NUL) {
-          len = STRLEN(file_path);
+          len = strlen(file_path);
           if (STRNCMP(rest_of_wildcards, "**", 2) == 0) {
             // pointer to the restrict byte
             // The restrict byte is not a character!
@@ -705,7 +705,7 @@ char_u *vim_findfile(void *search_ctx_arg)
             if (stackp->ffs_star_star_empty == 0) {
               // if not done before, expand '**' to empty
               stackp->ffs_star_star_empty = 1;
-              dirptrs[1] = (char *)stackp->ffs_fix_path;
+              dirptrs[1] = stackp->ffs_fix_path;
             }
           }
 
@@ -748,7 +748,7 @@ char_u *vim_findfile(void *search_ctx_arg)
         stackp->ffs_filearray_cur = 0;
         stackp->ffs_stage = 0;
       } else {
-        rest_of_wildcards = &stackp->ffs_wc_path[STRLEN(stackp->ffs_wc_path)];
+        rest_of_wildcards = &stackp->ffs_wc_path[strlen(stackp->ffs_wc_path)];
       }
 
       if (stackp->ffs_stage == 0) {
@@ -768,7 +768,7 @@ char_u *vim_findfile(void *search_ctx_arg)
               goto fail;
             }
             STRCPY(file_path, stackp->ffs_filearray[i]);
-            if (!add_pathsep((char *)file_path)) {
+            if (!add_pathsep(file_path)) {
               ff_free_stack_element(stackp);
               goto fail;
             }
@@ -776,7 +776,7 @@ char_u *vim_findfile(void *search_ctx_arg)
 
             // Try without extra suffix and then with suffixes
             // from 'suffixesadd'.
-            len = STRLEN(file_path);
+            len = strlen(file_path);
             if (search_ctx->ffsc_tagfile) {
               suf = "";
             } else {
@@ -784,14 +784,14 @@ char_u *vim_findfile(void *search_ctx_arg)
             }
             for (;;) {
               // if file exists and we didn't already find it
-              if ((path_with_url((char *)file_path)
-                   || (os_path_exists((char *)file_path)
+              if ((path_with_url(file_path)
+                   || (os_path_exists(file_path)
                        && (search_ctx->ffsc_find_what == FINDFILE_BOTH
                            || ((search_ctx->ffsc_find_what == FINDFILE_DIR)
-                               == os_isdir((char *)file_path)))))
+                               == os_isdir(file_path)))))
 #ifndef FF_VERBOSE
                   && (ff_check_visited(&search_ctx->ffsc_visited_list->ffvl_visited_list,
-                                       (char *)file_path, "") == OK)
+                                       file_path, "") == OK)
 #endif
                   ) {
 #ifdef FF_VERBOSE
@@ -812,12 +812,11 @@ char_u *vim_findfile(void *search_ctx_arg)
                 stackp->ffs_filearray_cur = i + 1;
                 ff_push(search_ctx, stackp);
 
-                if (!path_with_url((char *)file_path)) {
-                  simplify_filename(file_path);
+                if (!path_with_url(file_path)) {
+                  simplify_filename((char_u *)file_path);
                 }
-                if (os_dirname((char_u *)ff_expand_buffer, MAXPATHL)
-                    == OK) {
-                  p = (char_u *)path_shorten_fname((char *)file_path, ff_expand_buffer);
+                if (os_dirname((char_u *)ff_expand_buffer, MAXPATHL) == OK) {
+                  p = path_shorten_fname(file_path, ff_expand_buffer);
                   if (p != NULL) {
                     STRMOVE(file_path, p);
                   }
@@ -830,7 +829,7 @@ char_u *vim_findfile(void *search_ctx_arg)
                   verbose_leave_scroll();
                 }
 #endif
-                return file_path;
+                return (char_u *)file_path;
               }
 
               // Not found or found already, try next suffix.
@@ -838,7 +837,7 @@ char_u *vim_findfile(void *search_ctx_arg)
                 break;
               }
               assert(MAXPATHL >= len);
-              copy_option_part(&suf, (char *)file_path + len, MAXPATHL - len, ",");
+              copy_option_part(&suf, file_path + len, MAXPATHL - len, ",");
             }
           }
         } else {
@@ -849,7 +848,7 @@ char_u *vim_findfile(void *search_ctx_arg)
             }
             ff_push(search_ctx,
                     ff_create_stack_element(stackp->ffs_filearray[i],
-                                            (char *)rest_of_wildcards,
+                                            rest_of_wildcards,
                                             stackp->ffs_level - 1, 0));
           }
         }
@@ -863,7 +862,7 @@ char_u *vim_findfile(void *search_ctx_arg)
         for (int i = stackp->ffs_filearray_cur;
              i < stackp->ffs_filearray_size; i++) {
           if (path_fnamecmp(stackp->ffs_filearray[i],
-                            (char *)stackp->ffs_fix_path) == 0) {
+                            stackp->ffs_fix_path) == 0) {
             continue;             // don't repush same directory
           }
           if (!os_isdir(stackp->ffs_filearray[i])) {
@@ -871,7 +870,7 @@ char_u *vim_findfile(void *search_ctx_arg)
           }
           ff_push(search_ctx,
                   ff_create_stack_element(stackp->ffs_filearray[i],
-                                          (char *)stackp->ffs_wc_path, stackp->ffs_level - 1, 1));
+                                          stackp->ffs_wc_path, stackp->ffs_level - 1, 1));
         }
       }
 
@@ -911,13 +910,13 @@ char_u *vim_findfile(void *search_ctx_arg)
         goto fail;
       }
       STRCPY(file_path, search_ctx->ffsc_start_dir);
-      if (!add_pathsep((char *)file_path)) {
+      if (!add_pathsep(file_path)) {
         goto fail;
       }
       STRCAT(file_path, search_ctx->ffsc_fix_path);
 
       // create a new stack entry
-      sptr = ff_create_stack_element((char *)file_path,
+      sptr = ff_create_stack_element(file_path,
                                      search_ctx->ffsc_wc_path, search_ctx->ffsc_level, 0);
       ff_push(search_ctx, sptr);
     } else {
@@ -1136,12 +1135,12 @@ static ff_stack_T *ff_create_stack_element(char *fix_part, char *wc_part, int le
   if (fix_part == NULL) {
     fix_part = "";
   }
-  new->ffs_fix_path = (char_u *)xstrdup(fix_part);
+  new->ffs_fix_path = xstrdup(fix_part);
 
   if (wc_part == NULL) {
     wc_part = "";
   }
-  new->ffs_wc_path = (char_u *)xstrdup(wc_part);
+  new->ffs_wc_path = xstrdup(wc_part);
 
   return new;
 }
@@ -1242,7 +1241,7 @@ static int ff_path_in_stoplist(char *path, int path_len, char **stopdirs_v)
   }
 
   for (i = 0; stopdirs_v[i] != NULL; i++) {
-    if ((int)STRLEN(stopdirs_v[i]) > path_len) {
+    if ((int)strlen(stopdirs_v[i]) > path_len) {
       // match for parent directory. So '/home' also matches
       // '/home/rks'. Check for PATHSEP in stopdirs_v[i], else
       // '/home/r' would also match '/home/rks'
@@ -1288,11 +1287,11 @@ static int ff_path_in_stoplist(char *path, int path_len, char **stopdirs_v)
 /// @return  an allocated string for the file name.  NULL for error.
 char_u *find_file_in_path(char_u *ptr, size_t len, int options, int first, char_u *rel_fname)
 {
-  return find_file_in_path_option(ptr, len, options, first,
-                                  (*curbuf->b_p_path == NUL
-                                   ? p_path
-                                   : (char_u *)curbuf->b_p_path),
-                                  FINDFILE_BOTH, rel_fname, (char_u *)curbuf->b_p_sua);
+  return (char_u *)find_file_in_path_option((char *)ptr, len, options, first,
+                                            (*curbuf->b_p_path == NUL
+                                             ? (char *)p_path
+                                             : curbuf->b_p_path),
+                                            FINDFILE_BOTH, (char *)rel_fname, curbuf->b_p_sua);
 }
 
 static char *ff_file_to_find = NULL;
@@ -1323,8 +1322,8 @@ void free_findfile(void)
 /// @return  an allocated string for the file name.  NULL for error.
 char_u *find_directory_in_path(char_u *ptr, size_t len, int options, char_u *rel_fname)
 {
-  return find_file_in_path_option(ptr, len, options, true, p_cdpath,
-                                  FINDFILE_DIR, rel_fname, (char_u *)"");
+  return (char_u *)find_file_in_path_option((char *)ptr, len, options, true, (char *)p_cdpath,
+                                            FINDFILE_DIR, (char *)rel_fname, "");
 }
 
 /// @param ptr  file name
@@ -1334,13 +1333,12 @@ char_u *find_directory_in_path(char_u *ptr, size_t len, int options, char_u *rel
 /// @param find_what  FINDFILE_FILE, _DIR or _BOTH
 /// @param rel_fname  file name we are looking relative to.
 /// @param suffixes  list of suffixes, 'suffixesadd' option
-char_u *find_file_in_path_option(char_u *ptr, size_t len, int options, int first,
-                                 char_u *path_option, int find_what, char_u *rel_fname,
-                                 char_u *suffixes)
+char *find_file_in_path_option(char *ptr, size_t len, int options, int first, char *path_option,
+                               int find_what, char *rel_fname, char *suffixes)
 {
   static char *dir;
   static int did_findfile_init = false;
-  char_u save_char;
+  char save_char;
   char *file_name = NULL;
   char *buf = NULL;
   int rel_to_curdir;
@@ -1358,16 +1356,16 @@ char_u *find_file_in_path_option(char_u *ptr, size_t len, int options, int first
     // copy file name into NameBuff, expanding environment variables
     save_char = ptr[len];
     ptr[len] = NUL;
-    expand_env_esc(ptr, (char_u *)NameBuff, MAXPATHL, false, true, NULL);
+    expand_env_esc(ptr, NameBuff, MAXPATHL, false, true, NULL);
     ptr[len] = save_char;
 
     xfree(ff_file_to_find);
     ff_file_to_find = xstrdup(NameBuff);
     if (options & FNAME_UNESC) {
       // Change all "\ " to " ".
-      for (ptr = (char_u *)ff_file_to_find; *ptr != NUL; ptr++) {
+      for (ptr = ff_file_to_find; *ptr != NUL; ptr++) {
         if (ptr[0] == '\\' && ptr[1] == ' ') {
-          memmove(ptr, ptr + 1, STRLEN(ptr));
+          memmove(ptr, ptr + 1, strlen(ptr));
         }
       }
     }
@@ -1406,7 +1404,7 @@ char_u *find_file_in_path_option(char_u *ptr, size_t len, int options, int first
             && rel_to_curdir
             && (options & FNAME_REL)
             && rel_fname != NULL
-            && STRLEN(rel_fname) + l < MAXPATHL) {
+            && strlen(rel_fname) + l < MAXPATHL) {
           STRCPY(NameBuff, rel_fname);
           STRCPY(path_tail((char *)NameBuff), ff_file_to_find);
           l = strlen(NameBuff);
@@ -1416,7 +1414,7 @@ char_u *find_file_in_path_option(char_u *ptr, size_t len, int options, int first
         }
 
         // When the file doesn't exist, try adding parts of 'suffixesadd'.
-        buf = (char *)suffixes;
+        buf = suffixes;
         for (;;) {
           if ((os_path_exists(NameBuff)
                && (find_what == FINDFILE_BOTH
@@ -1440,7 +1438,7 @@ char_u *find_file_in_path_option(char_u *ptr, size_t len, int options, int first
     if (first == true) {
       // vim_findfile_free_visited can handle a possible NULL pointer
       vim_findfile_free_visited(fdip_search_ctx);
-      dir = (char *)path_option;
+      dir = path_option;
       did_findfile_init = false;
     }
 
@@ -1472,7 +1470,7 @@ char_u *find_file_in_path_option(char_u *ptr, size_t len, int options, int first
         r_ptr = vim_findfile_stopdir((char_u *)buf);
         fdip_search_ctx = vim_findfile_init(buf, ff_file_to_find,
                                             (char *)r_ptr, 100, false, find_what,
-                                            fdip_search_ctx, false, (char *)rel_fname);
+                                            fdip_search_ctx, false, rel_fname);
         if (fdip_search_ctx != NULL) {
           did_findfile_init = true;
         }
@@ -1501,7 +1499,7 @@ char_u *find_file_in_path_option(char_u *ptr, size_t len, int options, int first
   }
 
 theend:
-  return (char_u *)file_name;
+  return file_name;
 }
 
 void do_autocmd_dirchanged(char *new_dir, CdScope scope, CdCause cause, bool pre)
@@ -1608,9 +1606,9 @@ int vim_chdirfile(char *fname, CdCause cause)
 }
 
 /// Change directory to "new_dir". Search 'cdpath' for relative directory names.
-int vim_chdir(char_u *new_dir)
+int vim_chdir(char *new_dir)
 {
-  char *dir_name = (char *)find_directory_in_path(new_dir, STRLEN(new_dir),
+  char *dir_name = (char *)find_directory_in_path((char_u *)new_dir, strlen(new_dir),
                                                   FNAME_MESS, (char_u *)curbuf->b_ffname);
   if (dir_name == NULL) {
     return -1;
diff --git a/src/nvim/fileio.c b/src/nvim/fileio.c
index d6bc861c09..746788413f 100644
--- a/src/nvim/fileio.c
+++ b/src/nvim/fileio.c
@@ -993,7 +993,7 @@ retry:
             tlen = 0;
             for (;;) {
               p = (char_u *)ml_get(read_buf_lnum) + read_buf_col;
-              n = (int)STRLEN(p);
+              n = (int)strlen((char *)p);
               if ((int)tlen + n + 1 > size) {
                 // Filled up to "size", append partial line.
                 // Change NL to NUL to reverse the effect done
@@ -3737,22 +3737,22 @@ static bool msg_add_fileformat(int eol_type)
 /// Append line and character count to IObuff.
 void msg_add_lines(int insert_space, long lnum, off_T nchars)
 {
-  char_u *p;
+  char *p;
 
-  p = (char_u *)IObuff + STRLEN(IObuff);
+  p = IObuff + strlen(IObuff);
 
   if (insert_space) {
     *p++ = ' ';
   }
   if (shortmess(SHM_LINES)) {
-    vim_snprintf((char *)p, (size_t)(IOSIZE - (p - (char_u *)IObuff)), "%" PRId64 "L, %" PRId64 "B",
+    vim_snprintf(p, (size_t)(IOSIZE - (p - IObuff)), "%" PRId64 "L, %" PRId64 "B",
                  (int64_t)lnum, (int64_t)nchars);
   } else {
-    vim_snprintf((char *)p, (size_t)(IOSIZE - (p - (char_u *)IObuff)),
+    vim_snprintf(p, (size_t)(IOSIZE - (p - IObuff)),
                  NGETTEXT("%" PRId64 " line, ", "%" PRId64 " lines, ", lnum),
                  (int64_t)lnum);
-    p += STRLEN(p);
-    vim_snprintf((char *)p, (size_t)(IOSIZE - (p - (char_u *)IObuff)),
+    p += strlen(p);
+    vim_snprintf(p, (size_t)(IOSIZE - (p - IObuff)),
                  NGETTEXT("%" PRId64 " byte", "%" PRId64 " bytes", nchars),
                  (int64_t)nchars);
   }
@@ -4342,7 +4342,8 @@ char *modname(const char *fname, const char *ext, bool prepend_dot)
 /// @param fp file to read from
 ///
 /// @return true for EOF or error
-bool vim_fgets(char_u *buf, int size, FILE *fp) FUNC_ATTR_NONNULL_ALL
+bool vim_fgets(char *buf, int size, FILE *fp)
+  FUNC_ATTR_NONNULL_ALL
 {
   char *retval;
 
@@ -4351,7 +4352,7 @@ bool vim_fgets(char_u *buf, int size, FILE *fp) FUNC_ATTR_NONNULL_ALL
 
   do {
     errno = 0;
-    retval = fgets((char *)buf, size, fp);
+    retval = fgets(buf, size, fp);
   } while (retval == NULL && errno == EINTR && ferror(fp));
 
   if (buf[size - 2] != NUL && buf[size - 2] != '\n') {
diff --git a/src/nvim/help.c b/src/nvim/help.c
index 7ea7dfb709..8930f74e7f 100644
--- a/src/nvim/help.c
+++ b/src/nvim/help.c
@@ -570,7 +570,7 @@ int find_help_tags(const char *arg, int *num_matches, char ***matches, bool keep
 void cleanup_help_tags(int num_file, char **file)
 {
   char buf[4];
-  char_u *p = (char_u *)buf;
+  char *p = buf;
 
   if (p_hlg[0] != NUL && (p_hlg[0] != 'e' || p_hlg[1] != 'n')) {
     *p++ = '@';
@@ -785,7 +785,7 @@ void fix_help_buffer(void)
               if (fd == NULL) {
                 continue;
               }
-              vim_fgets((char_u *)IObuff, IOSIZE, fd);
+              vim_fgets(IObuff, IOSIZE, fd);
               if (IObuff[0] == '*'
                   && (s = vim_strchr((char *)IObuff + 1, '*'))
                   != NULL) {
@@ -944,7 +944,7 @@ static void helptags_one(char *dir, const char *ext, const char *tagfname, bool
     const char *const fname = files[fi] + dirlen + 1;
 
     bool firstline = true;
-    while (!vim_fgets((char_u *)IObuff, IOSIZE, fd) && !got_int) {
+    while (!vim_fgets(IObuff, IOSIZE, fd) && !got_int) {
       if (firstline) {
         // Detect utf-8 file by a non-ASCII char in the first line.
         TriState this_utf8 = kNone;
diff --git a/src/nvim/indent_c.c b/src/nvim/indent_c.c
index 77fe176de1..0f1159fb94 100644
--- a/src/nvim/indent_c.c
+++ b/src/nvim/indent_c.c
@@ -1003,7 +1003,7 @@ static int cin_iswhileofdo(const char_u *p, linenr_T lnum)  // XXX
       curwin->w_cursor.col++;
     }
     if ((trypos = findmatchlimit(NULL, 0, 0, curbuf->b_ind_maxparen)) != NULL
-        && *cin_skipcomment(ml_get_pos(trypos) + 1) == ';') {
+        && *cin_skipcomment((char_u *)ml_get_pos(trypos) + 1) == ';') {
       retval = true;
     }
     curwin->w_cursor = cursor_save;
diff --git a/src/nvim/insexpand.c b/src/nvim/insexpand.c
index ed851683fd..65380b92fc 100644
--- a/src/nvim/insexpand.c
+++ b/src/nvim/insexpand.c
@@ -1463,12 +1463,12 @@ static void ins_compl_files(int count, char **files, int thesaurus, int flags, r
 
     // Read dictionary file line by line.
     // Check each line for a match.
-    while (!got_int && !compl_interrupted && !vim_fgets(buf, LSIZE, fp)) {
+    while (!got_int && !compl_interrupted && !vim_fgets((char *)buf, LSIZE, fp)) {
       ptr = buf;
       while (vim_regexec(regmatch, (char *)buf, (colnr_T)(ptr - buf))) {
         ptr = (char_u *)regmatch->startp[0];
         if (ctrl_x_mode_line_or_eval()) {
-          ptr = find_line_end(ptr);
+          ptr = (char_u *)find_line_end((char *)ptr);
         } else {
           ptr = find_word_end(ptr);
         }
@@ -1529,12 +1529,13 @@ char_u *find_word_end(char_u *ptr)
 }
 
 /// Find the end of the line, omitting CR and NL at the end.
-/// Returns a pointer to just after the line.
-static char_u *find_line_end(char_u *ptr)
+///
+/// @return  a pointer to just after the line.
+static char *find_line_end(char *ptr)
 {
-  char_u *s;
+  char *s;
 
-  s = ptr + STRLEN(ptr);
+  s = ptr + strlen(ptr);
   while (s > ptr && (s[-1] == CAR || s[-1] == NL)) {
     s--;
   }
diff --git a/src/nvim/mapping.c b/src/nvim/mapping.c
index 76a646083e..cc8ebe10cf 100644
--- a/src/nvim/mapping.c
+++ b/src/nvim/mapping.c
@@ -419,7 +419,7 @@ static int str_to_mapargs(const char_u *strargs, bool is_unmap, MapArguments *ma
 
   // {lhs_end} is a pointer to the "terminating whitespace" after {lhs}.
   // Use that to initialize {rhs_start}.
-  const char_u *rhs_start = (char_u *)skipwhite((char *)lhs_end);
+  const char *rhs_start = skipwhite((char *)lhs_end);
 
   // Given {lhs} might be larger than MAXMAPLEN before replace_termcodes
   // (e.g. "<Space>" is longer than ' '), so first copy into a buffer.
@@ -430,9 +430,9 @@ static int str_to_mapargs(const char_u *strargs, bool is_unmap, MapArguments *ma
   char_u lhs_to_replace[256];
   STRLCPY(lhs_to_replace, to_parse, orig_lhs_len + 1);
 
-  size_t orig_rhs_len = STRLEN(rhs_start);
+  size_t orig_rhs_len = strlen(rhs_start);
   if (!set_maparg_lhs_rhs((char *)lhs_to_replace, orig_lhs_len,
-                          (char *)rhs_start, orig_rhs_len, LUA_NOREF,
+                          rhs_start, orig_rhs_len, LUA_NOREF,
                           CPO_TO_CPO_FLAGS, mapargs)) {
     return 1;
   }
@@ -471,7 +471,7 @@ static void map_add(buf_T *buf, mapblock_T **map_table, mapblock_T **abbr_table,
     args->orig_rhs = NULL;
     args->rhs_lua = LUA_NOREF;
   }
-  mp->m_keylen = (int)STRLEN(mp->m_keys);
+  mp->m_keylen = (int)strlen((char *)mp->m_keys);
   mp->m_noremap = noremap;
   mp->m_nowait = args->nowait;
   mp->m_silent = args->silent;
@@ -1392,7 +1392,7 @@ bool check_abbr(int c, char_u *ptr, int col, int mincol)
   int len;
   int scol;                     // starting column of the abbr.
   int j;
-  char_u *s;
+  char *s;
   char_u tb[MB_MAXBYTES + 4];
   mapblock_T *mp;
   mapblock_T *mp2;
@@ -1462,7 +1462,7 @@ bool check_abbr(int c, char_u *ptr, int col, int mincol)
         // Might have K_SPECIAL escaped mp->m_keys.
         q = xstrdup((char *)mp->m_keys);
         vim_unescape_ks((char_u *)q);
-        qlen = (int)STRLEN(q);
+        qlen = (int)strlen(q);
       }
       // find entries with right mode and keys
       match = (mp->m_mode & State)
@@ -1505,9 +1505,9 @@ bool check_abbr(int c, char_u *ptr, int col, int mincol)
           int newlen = utf_char2bytes(c, (char *)tb + j);
           tb[j + newlen] = NUL;
           // Need to escape K_SPECIAL.
-          char_u *escaped = (char_u *)vim_strsave_escape_ks((char *)tb + j);
+          char *escaped = vim_strsave_escape_ks((char *)tb + j);
           if (escaped != NULL) {
-            newlen = (int)STRLEN(escaped);
+            newlen = (int)strlen(escaped);
             memmove(tb + j, escaped, (size_t)newlen);
             j += newlen;
             xfree(escaped);
@@ -1518,15 +1518,15 @@ bool check_abbr(int c, char_u *ptr, int col, int mincol)
         (void)ins_typebuf((char *)tb, 1, 0, true, mp->m_silent);
       }
       if (mp->m_expr) {
-        s = (char_u *)eval_map_expr(mp, c);
+        s = eval_map_expr(mp, c);
       } else {
-        s = (char_u *)mp->m_str;
+        s = mp->m_str;
       }
       if (s != NULL) {
         // insert the to string
-        (void)ins_typebuf((char *)s, mp->m_noremap, 0, true, mp->m_silent);
+        (void)ins_typebuf(s, mp->m_noremap, 0, true, mp->m_silent);
         // no abbrev. for these chars
-        typebuf.tb_no_abbr_cnt += (int)STRLEN(s) + j + 1;
+        typebuf.tb_no_abbr_cnt += (int)strlen(s) + j + 1;
         if (mp->m_expr) {
           xfree(s);
         }
@@ -1597,7 +1597,7 @@ char *eval_map_expr(mapblock_T *mp, int c)
   char *res = NULL;
 
   if (mp->m_replace_keycodes) {
-    replace_termcodes(p, STRLEN(p), &res, REPTERM_DO_LT, NULL, CPO_TO_CPO_FLAGS);
+    replace_termcodes(p, strlen(p), &res, REPTERM_DO_LT, NULL, CPO_TO_CPO_FLAGS);
   } else {
     // Escape K_SPECIAL in the result to be able to use the string as typeahead.
     res = vim_strsave_escape_ks(p);
@@ -1926,14 +1926,14 @@ int put_escstr(FILE *fd, char_u *strstart, int what)
 /// @param abbr  do abbreviations
 /// @param mp_ptr  return: pointer to mapblock or NULL
 /// @param local_ptr  return: buffer-local mapping or NULL
-char_u *check_map(char_u *keys, int mode, int exact, int ign_mod, int abbr, mapblock_T **mp_ptr,
-                  int *local_ptr, int *rhs_lua)
+char *check_map(char *keys, int mode, int exact, int ign_mod, int abbr, mapblock_T **mp_ptr,
+                int *local_ptr, int *rhs_lua)
 {
   int len, minlen;
   mapblock_T *mp;
   *rhs_lua = LUA_NOREF;
 
-  len = (int)STRLEN(keys);
+  len = (int)strlen(keys);
   for (int local = 1; local >= 0; local--) {
     // loop over all hash lists
     for (int hash = 0; hash < 256; hash++) {
@@ -1970,7 +1970,7 @@ char_u *check_map(char_u *keys, int mode, int exact, int ign_mod, int abbr, mapb
               *local_ptr = local;
             }
             *rhs_lua = mp->m_luaref;
-            return mp->m_luaref == LUA_NOREF ? (char_u *)mp->m_str : NULL;
+            return mp->m_luaref == LUA_NOREF ? mp->m_str : NULL;
           }
         }
       }
@@ -2104,7 +2104,8 @@ static void get_maparg(typval_T *argvars, typval_T *rettv, int exact)
   mapblock_T *mp = NULL;
   int buffer_local;
   LuaRef rhs_lua;
-  char_u *rhs = check_map(keys_simplified, mode, exact, false, abbr, &mp, &buffer_local, &rhs_lua);
+  char *rhs = check_map((char *)keys_simplified, mode, exact, false, abbr, &mp, &buffer_local,
+                        &rhs_lua);
   if (did_simplify) {
     // When the lhs is being simplified the not-simplified keys are
     // preferred for printing, like in do_map().
@@ -2112,7 +2113,7 @@ static void get_maparg(typval_T *argvars, typval_T *rettv, int exact)
                             strlen(keys),
                             &alt_keys_buf, flags | REPTERM_NO_SIMPLIFY, NULL,
                             CPO_TO_CPO_FLAGS);
-    rhs = check_map((char_u *)alt_keys_buf, mode, exact, false, abbr, &mp, &buffer_local, &rhs_lua);
+    rhs = check_map(alt_keys_buf, mode, exact, false, abbr, &mp, &buffer_local, &rhs_lua);
   }
 
   if (!get_dict) {
@@ -2121,7 +2122,7 @@ static void get_maparg(typval_T *argvars, typval_T *rettv, int exact)
       if (*rhs == NUL) {
         rettv->vval.v_string = xstrdup("<Nop>");
       } else {
-        rettv->vval.v_string = str2special_save((char *)rhs, false, false);
+        rettv->vval.v_string = str2special_save(rhs, false, false);
       }
     } else if (rhs_lua != LUA_NOREF) {
       rettv->vval.v_string = nlua_funcref_str(mp->m_luaref);
diff --git a/src/nvim/memline.c b/src/nvim/memline.c
index 5f21a3dd0e..6e1316d651 100644
--- a/src/nvim/memline.c
+++ b/src/nvim/memline.c
@@ -1262,7 +1262,7 @@ int recover_names(char_u *fname, int list, int nr, char **fname_out)
         names[2] = concat_fnames(dir_name, ".sw?", true);
         num_names = 3;
       } else {
-        int len = (int)STRLEN(dir_name);
+        int len = (int)strlen(dir_name);
         p = dir_name + len;
         if (after_pathsep(dir_name, p)
             && len > 1
@@ -1745,10 +1745,10 @@ char *ml_get(linenr_T lnum)
 }
 
 /// @return  pointer to position "pos".
-char_u *ml_get_pos(const pos_T *pos)
+char *ml_get_pos(const pos_T *pos)
   FUNC_ATTR_NONNULL_ALL
 {
-  return (char_u *)ml_get_buf(curbuf, pos->lnum, false) + pos->col;
+  return ml_get_buf(curbuf, pos->lnum, false) + pos->col;
 }
 
 /// @return  codepoint at pos. pos must be either valid or have col set to MAXCOL!
@@ -1759,7 +1759,7 @@ int gchar_pos(pos_T *pos)
   if (pos->col == MAXCOL) {
     return NUL;
   }
-  return utf_ptr2char((char *)ml_get_pos(pos));
+  return utf_ptr2char(ml_get_pos(pos));
 }
 
 /// @param will_change  true mark the buffer dirty (chars in the line will be changed)
@@ -1828,7 +1828,7 @@ errorret:
   }
   if (will_change) {
     buf->b_ml.ml_flags |= (ML_LOCKED_DIRTY | ML_LOCKED_POS);
-    ml_add_deleted_len_buf(buf, buf->b_ml.ml_line_ptr, -1);
+    ml_add_deleted_len_buf(buf, (char *)buf->b_ml.ml_line_ptr, -1);
   }
 
   return (char *)buf->b_ml.ml_line_ptr;
@@ -2304,10 +2304,10 @@ static int ml_append_int(buf_T *buf, linenr_T lnum, char_u *line, colnr_T len, b
 
 void ml_add_deleted_len(char *ptr, ssize_t len)
 {
-  ml_add_deleted_len_buf(curbuf, (char_u *)ptr, len);
+  ml_add_deleted_len_buf(curbuf, ptr, len);
 }
 
-void ml_add_deleted_len_buf(buf_T *buf, char_u *ptr, ssize_t len)
+void ml_add_deleted_len_buf(buf_T *buf, char *ptr, ssize_t len)
 {
   if (inhibit_delete_count) {
     return;
@@ -2319,7 +2319,7 @@ void ml_add_deleted_len_buf(buf_T *buf, char_u *ptr, ssize_t len)
   curbuf->deleted_bytes += (size_t)len + 1;
   curbuf->deleted_bytes2 += (size_t)len + 1;
   if (curbuf->update_need_codepoints) {
-    mb_utflen(ptr, (size_t)len, &curbuf->deleted_codepoints,
+    mb_utflen((char_u *)ptr, (size_t)len, &curbuf->deleted_codepoints,
               &curbuf->deleted_codeunits);
     curbuf->deleted_codepoints++;  // NL char
     curbuf->deleted_codeunits++;
@@ -2362,14 +2362,14 @@ int ml_replace_buf(buf_T *buf, linenr_T lnum, char *line, bool copy)
   if (buf->b_ml.ml_line_lnum != lnum) {  // other line buffered
     ml_flush_line(buf);  // flush it
   } else if (buf->b_ml.ml_flags & ML_LINE_DIRTY) {  // same line allocated
-    ml_add_deleted_len_buf(buf, buf->b_ml.ml_line_ptr, -1);
+    ml_add_deleted_len_buf(buf, (char *)buf->b_ml.ml_line_ptr, -1);
     readlen = false;  // already added the length
 
     xfree(buf->b_ml.ml_line_ptr);  // free it
   }
 
   if (readlen && kv_size(buf->update_callbacks)) {
-    ml_add_deleted_len_buf(buf, (char_u *)ml_get_buf(buf, lnum, false), -1);
+    ml_add_deleted_len_buf(buf, ml_get_buf(buf, lnum, false), -1);
   }
 
   buf->b_ml.ml_line_ptr = (char_u *)line;
@@ -2446,7 +2446,7 @@ static int ml_delete_int(buf_T *buf, linenr_T lnum, bool message)
   // Line should always have an NL char internally (represented as NUL),
   // even if 'noeol' is set.
   assert(line_size >= 1);
-  ml_add_deleted_len_buf(buf, (char_u *)dp + line_start, line_size - 1);
+  ml_add_deleted_len_buf(buf, (char *)dp + line_start, line_size - 1);
 
   // special case: If there is only one line in the data block it becomes empty.
   // Then we have to remove the entry, pointing to this data block, from the
@@ -3003,8 +3003,8 @@ int resolve_symlink(const char *fname, char *buf)
     if (path_is_absolute((char_u *)buf)) {
       STRCPY(tmp, buf);
     } else {
-      char_u *tail = (char_u *)path_tail(tmp);
-      if (STRLEN(tail) + strlen(buf) >= MAXPATHL) {
+      char *tail = path_tail(tmp);
+      if (strlen(tail) + strlen(buf) >= MAXPATHL) {
         return FAIL;
       }
       STRCPY(tail, buf);
@@ -3968,7 +3968,7 @@ int inc(pos_T *lp)
 {
   // when searching position may be set to end of a line
   if (lp->col != MAXCOL) {
-    const char_u *const p = ml_get_pos(lp);
+    const char *const p = ml_get_pos(lp);
     if (*p != NUL) {  // still within line, move to next char (may be NUL)
       const int l = utfc_ptr2len((char *)p);
 
diff --git a/src/nvim/normal.c b/src/nvim/normal.c
index ed689df91c..5536b7ba08 100644
--- a/src/nvim/normal.c
+++ b/src/nvim/normal.c
@@ -1832,11 +1832,11 @@ void clear_showcmd(void)
       int chars = 0;
 
       if (cursor_bot) {
-        s = ml_get_pos(&VIsual);
+        s = (char_u *)ml_get_pos(&VIsual);
         e = (char_u *)get_cursor_pos_ptr();
       } else {
         s = (char_u *)get_cursor_pos_ptr();
-        e = ml_get_pos(&VIsual);
+        e = (char_u *)ml_get_pos(&VIsual);
       }
       while ((*p_sel != 'e') ? s <= e : s < e) {
         l = utfc_ptr2len((char *)s);
@@ -2740,7 +2740,7 @@ static int nv_zg_zw(cmdarg_T *cap, int nchar)
     len = spell_move_to(curwin, FORWARD, true, true, NULL);
     emsg_off--;
     if (len != 0 && curwin->w_cursor.col <= pos.col) {
-      ptr = (char *)ml_get_pos(&curwin->w_cursor);
+      ptr = ml_get_pos(&curwin->w_cursor);
     }
     curwin->w_cursor = pos;
   }
@@ -3586,10 +3586,10 @@ bool get_visual_text(cmdarg_T *cap, char **pp, size_t *lenp)
     *lenp = strlen(*pp);
   } else {
     if (lt(curwin->w_cursor, VIsual)) {
-      *pp = (char *)ml_get_pos(&curwin->w_cursor);
+      *pp = ml_get_pos(&curwin->w_cursor);
       *lenp = (size_t)VIsual.col - (size_t)curwin->w_cursor.col + 1;
     } else {
-      *pp = (char *)ml_get_pos(&VIsual);
+      *pp = ml_get_pos(&VIsual);
       *lenp = (size_t)curwin->w_cursor.col - (size_t)VIsual.col + 1;
     }
     if (**pp == NUL) {
@@ -4006,7 +4006,7 @@ static int normal_search(cmdarg_T *cap, int dir, char *pat, int opt, int *wrappe
   curwin->w_set_curswant = true;
 
   CLEAR_FIELD(sia);
-  int i = do_search(cap->oap, dir, dir, (char_u *)pat, cap->count1,
+  int i = do_search(cap->oap, dir, dir, pat, cap->count1,
                     opt | SEARCH_OPT | SEARCH_ECHO | SEARCH_MSG, &sia);
   if (wrapped != NULL) {
     *wrapped = sia.sa_wrapped;
diff --git a/src/nvim/ops.c b/src/nvim/ops.c
index f1814291b8..0cae0e854f 100644
--- a/src/nvim/ops.c
+++ b/src/nvim/ops.c
@@ -80,7 +80,7 @@ struct block_def {
   int startspaces;              // 'extra' cols before first char
   int endspaces;                // 'extra' cols after last char
   int textlen;                  // chars in block
-  char_u *textstart;       // pointer to 1st char (partially) in block
+  char *textstart;              // pointer to 1st char (partially) in block
   colnr_T textcol;              // index of chars (partially) in block
   colnr_T start_vcol;           // start col of 1st char wholly inside block
   colnr_T end_vcol;             // start col of 1st char wholly after block
@@ -90,7 +90,7 @@ struct block_def {
   int pre_whitesp;              // screen cols of ws before block
   int pre_whitesp_c;            // chars of ws before block
   colnr_T end_char_vcols;       // number of vcols of post-block char
-  colnr_T start_char_vcols;       // number of vcols of pre-block char
+  colnr_T start_char_vcols;     // number of vcols of pre-block char
 };
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
@@ -358,7 +358,7 @@ static void shift_block(oparg_T *oap, int amount)
     return;   // multiplication overflow
   }
 
-  char_u *const oldp = (char_u *)get_cursor_line_ptr();
+  char *const oldp = get_cursor_line_ptr();
 
   int startcol, oldlen, newlen;
 
@@ -369,9 +369,9 @@ static void shift_block(oparg_T *oap, int amount)
     //  4. Construct new string
     total += bd.pre_whitesp;    // all virtual WS up to & incl a split TAB
     colnr_T ws_vcol = bd.start_vcol - bd.pre_whitesp;
-    char_u *old_textstart = bd.textstart;
+    char *old_textstart = bd.textstart;
     if (bd.startspaces) {
-      if (utfc_ptr2len((char *)bd.textstart) == 1) {
+      if (utfc_ptr2len(bd.textstart) == 1) {
         bd.textstart++;
       } else {
         ws_vcol = 0;
@@ -382,13 +382,13 @@ static void shift_block(oparg_T *oap, int amount)
     // TODO(vim): is passing bd.textstart for start of the line OK?
     chartabsize_T cts;
     init_chartabsize_arg(&cts, curwin, curwin->w_cursor.lnum,
-                         bd.start_vcol, (char *)bd.textstart, (char *)bd.textstart);
+                         bd.start_vcol, bd.textstart, bd.textstart);
     while (ascii_iswhite(*cts.cts_ptr)) {
       incr = lbr_chartabsize_adv(&cts);
       total += incr;
       cts.cts_vcol += incr;
     }
-    bd.textstart = (char_u *)cts.cts_ptr;
+    bd.textstart = cts.cts_ptr;
     bd.start_vcol = cts.cts_vcol;
     clear_chartabsize_arg(&cts);
 
@@ -403,7 +403,7 @@ static void shift_block(oparg_T *oap, int amount)
     // if we're splitting a TAB, allow for it
     int col_pre = bd.pre_whitesp_c - (bd.startspaces != 0);
     bd.textcol -= col_pre;
-    const int len = (int)STRLEN(bd.textstart) + 1;
+    const int len = (int)strlen(bd.textstart) + 1;
     int col = bd.textcol + i + j + len;
     assert(col >= 0);
     newp = (char_u *)xmalloc((size_t)col);
@@ -419,14 +419,14 @@ static void shift_block(oparg_T *oap, int amount)
   } else {  // left
     colnr_T destination_col;      // column to which text in block will
                                   // be shifted
-    char_u *verbatim_copy_end;    // end of the part of the line which is
+    char *verbatim_copy_end;      // end of the part of the line which is
                                   // copied verbatim
     colnr_T verbatim_copy_width;  // the (displayed) width of this part
                                   // of line
     size_t fill;                  // nr of spaces that replace a TAB
     size_t new_line_len;          // the length of the line after the
                                   // block shift
-    char *non_white = (char *)bd.textstart;
+    char *non_white = bd.textstart;
 
     // Firstly, let's find the first non-whitespace character that is
     // displayed after the block's start column and the character's column
@@ -446,7 +446,7 @@ static void shift_block(oparg_T *oap, int amount)
 
     chartabsize_T cts;
     init_chartabsize_arg(&cts, curwin, curwin->w_cursor.lnum,
-                         non_white_col, (char *)bd.textstart, non_white);
+                         non_white_col, bd.textstart, non_white);
     while (ascii_iswhite(*cts.cts_ptr)) {
       incr = lbr_chartabsize_adv(&cts);
       cts.cts_vcol += incr;
@@ -475,7 +475,7 @@ static void shift_block(oparg_T *oap, int amount)
       verbatim_copy_width -= bd.start_char_vcols;
     }
     init_chartabsize_arg(&cts, curwin, 0, verbatim_copy_width,
-                         (char *)bd.textstart, (char *)verbatim_copy_end);
+                         bd.textstart, verbatim_copy_end);
     while (cts.cts_vcol < destination_col) {
       incr = lbr_chartabsize(&cts);
       if (cts.cts_vcol + incr > destination_col) {
@@ -485,7 +485,7 @@ static void shift_block(oparg_T *oap, int amount)
       MB_PTR_ADV(cts.cts_ptr);
     }
     verbatim_copy_width = cts.cts_vcol;
-    verbatim_copy_end = (char_u *)cts.cts_ptr;
+    verbatim_copy_end = cts.cts_ptr;
     clear_chartabsize_arg(&cts);
 
     // If "destination_col" is different from the width of the initial
@@ -504,7 +504,7 @@ static void shift_block(oparg_T *oap, int amount)
 
     newp = (char_u *)xmalloc(new_line_len);
     startcol = (int)verbatim_diff;
-    oldlen = bd.textcol + (int)(non_white - (char *)bd.textstart) - (int)verbatim_diff;
+    oldlen = bd.textcol + (int)(non_white - bd.textstart) - (int)verbatim_diff;
     newlen = (int)fill;
     memmove(newp, oldp, verbatim_diff);
     memset(newp + verbatim_diff, ' ', fill);
@@ -2095,7 +2095,7 @@ void op_tilde(oparg_T *oap)
       for (;;) {
         did_change |= swapchars(oap->op_type, &pos,
                                 pos.lnum == oap->end.lnum ? oap->end.col + 1 :
-                                (int)STRLEN(ml_get_pos(&pos)));
+                                (int)strlen(ml_get_pos(&pos)));
         if (ltoreq(oap->end, pos) || inc(&pos) == -1) {
           break;
         }
@@ -2138,7 +2138,7 @@ 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((char *)ml_get_pos(pos));
+    const int len = utfc_ptr2len(ml_get_pos(pos));
 
     // we're counting bytes, not characters
     if (len > 0) {
@@ -2727,7 +2727,7 @@ static void op_yank_reg(oparg_T *oap, bool message, yankreg_T *reg, bool append)
       } else {
         bd.textlen = endcol - startcol + oap->inclusive;
       }
-      bd.textstart = (char_u *)p + startcol;
+      bd.textstart = p + startcol;
       yank_copy_line(reg, &bd, y_idx, false);
       break;
     }
@@ -2838,7 +2838,7 @@ static void yank_copy_line(yankreg_T *reg, struct block_def *bd, size_t y_idx,
     int s = bd->textlen + bd->endspaces;
 
     while (s > 0 && ascii_iswhite(*(bd->textstart + s - 1))) {
-      s = s - utf_head_off((char *)bd->textstart, (char *)bd->textstart + s - 1) - 1;
+      s = s - utf_head_off(bd->textstart, bd->textstart + s - 1) - 1;
       pnew--;
     }
   }
@@ -4346,7 +4346,7 @@ static void block_prep(oparg_T *oap, struct block_def *bdp, linenr_T lnum, bool
     bdp->textlen = (int)(pend - pstart);
   }
   bdp->textcol = (colnr_T)(pstart - line);
-  bdp->textstart = (char_u *)pstart;
+  bdp->textstart = pstart;
   restore_lbr(lbr_saved);
 }
 
@@ -5403,7 +5403,7 @@ void cursor_pos_info(dict_T *dict)
           virtual_op = virtual_active();
           block_prep(&oparg, &bd, lnum, false);
           virtual_op = kNone;
-          s = (char *)bd.textstart;
+          s = bd.textstart;
           len = (long)bd.textlen;
           break;
         case 'V':
@@ -6085,7 +6085,7 @@ 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((char *)ml_get_pos(&oap->end));
+      const int l = utfc_ptr2len(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 80931016a5..b78fc7c27a 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -702,14 +702,14 @@ void set_helplang_default(const char *lang)
   int idx = findoption("hlg");
   if (idx >= 0 && !(options[idx].flags & P_WAS_SET)) {
     if (options[idx].flags & P_ALLOCED) {
-      free_string_option((char *)p_hlg);
+      free_string_option(p_hlg);
     }
-    p_hlg = (char_u *)xmemdupz(lang, lang_len);
+    p_hlg = xmemdupz(lang, lang_len);
     // zh_CN becomes "cn", zh_TW becomes "tw".
-    if (STRNICMP(p_hlg, "zh_", 3) == 0 && STRLEN(p_hlg) >= 5) {
-      p_hlg[0] = (char_u)TOLOWER_ASC(p_hlg[3]);
-      p_hlg[1] = (char_u)TOLOWER_ASC(p_hlg[4]);
-    } else if (STRLEN(p_hlg) >= 1 && *p_hlg == 'C') {
+    if (STRNICMP(p_hlg, "zh_", 3) == 0 && strlen(p_hlg) >= 5) {
+      p_hlg[0] = (char)TOLOWER_ASC(p_hlg[3]);
+      p_hlg[1] = (char)TOLOWER_ASC(p_hlg[4]);
+    } else if (strlen(p_hlg) >= 1 && *p_hlg == 'C') {
       // any C like setting, such as C.UTF-8, becomes "en"
       p_hlg[0] = 'e';
       p_hlg[1] = 'n';
@@ -1686,9 +1686,9 @@ static char *option_expand(int opt_idx, char *val)
   // Escape spaces when expanding 'tags', they are used to separate file
   // names.
   // For 'spellsuggest' expand after "file:".
-  expand_env_esc((char_u *)val, (char_u *)NameBuff, MAXPATHL,
+  expand_env_esc(val, NameBuff, MAXPATHL,
                  (char_u **)options[opt_idx].var == &p_tags, false,
-                 (char_u **)options[opt_idx].var == (char_u **)&p_sps ? (char_u *)"file:" :
+                 (char_u **)options[opt_idx].var == (char_u **)&p_sps ? "file:" :
                  NULL);
   if (strcmp(NameBuff, val) == 0) {   // they are the same
     return NULL;
@@ -4565,13 +4565,13 @@ static char_u expand_option_name[5] = { 't', '_', NUL, NUL, NUL };
 static int expand_option_flags = 0;
 
 /// @param opt_flags  OPT_GLOBAL and/or OPT_LOCAL
-void set_context_in_set_cmd(expand_T *xp, char_u *arg, int opt_flags)
+void set_context_in_set_cmd(expand_T *xp, char *arg, int opt_flags)
 {
-  char_u nextchar;
+  char nextchar;
   uint32_t flags = 0;           // init for GCC
   int opt_idx = 0;              // init for GCC
-  char_u *p;
-  char_u *s;
+  char *p;
+  char *s;
   int is_term_option = false;
   int key;
 
@@ -4579,12 +4579,12 @@ void set_context_in_set_cmd(expand_T *xp, char_u *arg, int opt_flags)
 
   xp->xp_context = EXPAND_SETTINGS;
   if (*arg == NUL) {
-    xp->xp_pattern = (char *)arg;
+    xp->xp_pattern = arg;
     return;
   }
-  p = arg + STRLEN(arg) - 1;
+  p = arg + strlen(arg) - 1;
   if (*p == ' ' && *(p - 1) != '\\') {
-    xp->xp_pattern = (char *)p + 1;
+    xp->xp_pattern = p + 1;
     return;
   }
   while (p > arg) {
@@ -4610,7 +4610,7 @@ void set_context_in_set_cmd(expand_T *xp, char_u *arg, int opt_flags)
     xp->xp_context = EXPAND_BOOL_SETTINGS;
     p += 3;
   }
-  xp->xp_pattern = (char *)p;
+  xp->xp_pattern = p;
   arg = p;
   if (*arg == '<') {
     while (*p != '>') {
@@ -4618,7 +4618,7 @@ void set_context_in_set_cmd(expand_T *xp, char_u *arg, int opt_flags)
         return;
       }
     }
-    key = get_special_key_code(arg + 1);
+    key = get_special_key_code((char_u *)arg + 1);
     if (key == 0) {                 // unknown name
       xp->xp_context = EXPAND_NOTHING;
       return;
@@ -4638,8 +4638,8 @@ void set_context_in_set_cmd(expand_T *xp, char_u *arg, int opt_flags)
       }
       nextchar = *++p;
       is_term_option = true;
-      expand_option_name[2] = p[-2];
-      expand_option_name[3] = p[-1];
+      expand_option_name[2] = (char_u)p[-2];
+      expand_option_name[3] = (char_u)p[-1];
     } else {
       // Allow * wildcard.
       while (ASCII_ISALNUM(*p) || *p == '_' || *p == '*') {
@@ -4678,7 +4678,7 @@ void set_context_in_set_cmd(expand_T *xp, char_u *arg, int opt_flags)
     } else {
       expand_option_idx = opt_idx;
     }
-    xp->xp_pattern = (char *)p + 1;
+    xp->xp_pattern = p + 1;
     return;
   }
   xp->xp_context = EXPAND_NOTHING;
@@ -4686,29 +4686,29 @@ void set_context_in_set_cmd(expand_T *xp, char_u *arg, int opt_flags)
     return;
   }
 
-  xp->xp_pattern = (char *)p + 1;
+  xp->xp_pattern = p + 1;
 
   if (flags & P_EXPAND) {
-    p = options[opt_idx].var;
-    if (p == (char_u *)&p_bdir
-        || p == (char_u *)&p_dir
-        || p == (char_u *)&p_path
-        || p == (char_u *)&p_pp
-        || p == (char_u *)&p_rtp
-        || p == (char_u *)&p_cdpath
-        || p == (char_u *)&p_vdir) {
+    p = (char *)options[opt_idx].var;
+    if (p == (char *)&p_bdir
+        || p == (char *)&p_dir
+        || p == (char *)&p_path
+        || p == (char *)&p_pp
+        || p == (char *)&p_rtp
+        || p == (char *)&p_cdpath
+        || p == (char *)&p_vdir) {
       xp->xp_context = EXPAND_DIRECTORIES;
-      if (p == (char_u *)&p_path || p == (char_u *)&p_cdpath) {
+      if (p == (char *)&p_path || p == (char *)&p_cdpath) {
         xp->xp_backslash = XP_BS_THREE;
       } else {
         xp->xp_backslash = XP_BS_ONE;
       }
-    } else if (p == (char_u *)&p_ft) {
+    } else if (p == (char *)&p_ft) {
       xp->xp_context = EXPAND_FILETYPE;
     } else {
       xp->xp_context = EXPAND_FILES;
       // for 'tags' need three backslashes for a space
-      if (p == (char_u *)&p_tags) {
+      if (p == (char *)&p_tags) {
         xp->xp_backslash = XP_BS_THREE;
       } else {
         xp->xp_backslash = XP_BS_ONE;
@@ -4718,16 +4718,16 @@ void set_context_in_set_cmd(expand_T *xp, char_u *arg, int opt_flags)
 
   // For an option that is a list of file names, find the start of the
   // last file name.
-  for (p = arg + STRLEN(arg) - 1; p > (char_u *)xp->xp_pattern; p--) {
+  for (p = arg + strlen(arg) - 1; p > xp->xp_pattern; p--) {
     // count number of backslashes before ' ' or ','
     if (*p == ' ' || *p == ',') {
       s = p;
-      while (s > (char_u *)xp->xp_pattern && *(s - 1) == '\\') {
+      while (s > xp->xp_pattern && *(s - 1) == '\\') {
         s--;
       }
       if ((*p == ' ' && (xp->xp_backslash == XP_BS_THREE && (p - s) < 3))
           || (*p == ',' && (flags & P_COMMA) && ((p - s) & 1) == 0)) {
-        xp->xp_pattern = (char *)p + 1;
+        xp->xp_pattern = p + 1;
         break;
       }
     }
@@ -4735,7 +4735,7 @@ void set_context_in_set_cmd(expand_T *xp, char_u *arg, int opt_flags)
     // for 'spellsuggest' start at "file:"
     if (options[opt_idx].var == (char_u *)&p_sps
         && STRNCMP(p, "file:", 5) == 0) {
-      xp->xp_pattern = (char *)p + 5;
+      xp->xp_pattern = p + 5;
       break;
     }
   }
diff --git a/src/nvim/option_defs.h b/src/nvim/option_defs.h
index c60925d485..40ce022bea 100644
--- a/src/nvim/option_defs.h
+++ b/src/nvim/option_defs.h
@@ -545,7 +545,7 @@ EXTERN char_u *p_guifont;       // 'guifont'
 EXTERN char_u *p_guifontwide;   // 'guifontwide'
 EXTERN char *p_hf;              // 'helpfile'
 EXTERN long p_hh;               // 'helpheight'
-EXTERN char_u *p_hlg;           // 'helplang'
+EXTERN char *p_hlg;             // 'helplang'
 EXTERN int p_hid;               // 'hidden'
 EXTERN char *p_hl;              // 'highlight'
 EXTERN int p_hls;               // 'hlsearch'
diff --git a/src/nvim/optionstr.c b/src/nvim/optionstr.c
index 5022334582..7522745bcb 100644
--- a/src/nvim/optionstr.c
+++ b/src/nvim/optionstr.c
@@ -741,9 +741,9 @@ char *did_set_string_option(int opt_idx, char **varp, char *oldval, char *errbuf
     }
   } else if (varp == &curwin->w_p_cc) {  // 'colorcolumn'
     errmsg = check_colorcolumn(curwin);
-  } else if (varp == (char **)&p_hlg) {  // 'helplang'
+  } else if (varp == &p_hlg) {  // 'helplang'
     // Check for "", "ab", "ab,cd", etc.
-    for (s = (char *)p_hlg; *s != NUL; s += 3) {
+    for (s = p_hlg; *s != NUL; s += 3) {
       if (s[1] == NUL || ((s[2] != ',' || s[3] == NUL) && s[2] != NUL)) {
         errmsg = e_invarg;
         break;
diff --git a/src/nvim/os/env.c b/src/nvim/os/env.c
index 8f58f5217e..dac3cae199 100644
--- a/src/nvim/os/env.c
+++ b/src/nvim/os/env.c
@@ -554,7 +554,7 @@ char *expand_env_save(char *src)
 char_u *expand_env_save_opt(char_u *src, bool one)
 {
   char_u *p = xmalloc(MAXPATHL);
-  expand_env_esc(src, p, MAXPATHL, false, one, NULL);
+  expand_env_esc((char *)src, (char *)p, MAXPATHL, false, one, NULL);
   return p;
 }
 
@@ -568,7 +568,7 @@ char_u *expand_env_save_opt(char_u *src, bool one)
 /// @param dstlen     Maximum length of the result
 void expand_env(char *src, char *dst, int dstlen)
 {
-  expand_env_esc((char_u *)src, (char_u *)dst, dstlen, false, false, NULL);
+  expand_env_esc(src, dst, dstlen, false, false, NULL);
 }
 
 /// Expand environment variable with path name and escaping.
@@ -580,34 +580,34 @@ void expand_env(char *src, char *dst, int dstlen)
 /// @param esc        Escape spaces in expanded variables
 /// @param one        `srcp` is a single filename
 /// @param prefix     Start again after this (can be NULL)
-void expand_env_esc(char_u *restrict srcp, char_u *restrict dst, int dstlen, bool esc, bool one,
-                    char_u *prefix)
+void expand_env_esc(char *restrict srcp, char *restrict dst, int dstlen, bool esc, bool one,
+                    char *prefix)
   FUNC_ATTR_NONNULL_ARG(1, 2)
 {
-  char_u *tail;
-  char_u *var;
+  char *tail;
+  char *var;
   bool copy_char;
   bool mustfree;  // var was allocated, need to free it later
   bool at_start = true;  // at start of a name
 
-  int prefix_len = (prefix == NULL) ? 0 : (int)STRLEN(prefix);
+  int prefix_len = (prefix == NULL) ? 0 : (int)strlen(prefix);
 
-  char *src = skipwhite((char *)srcp);
+  char *src = skipwhite(srcp);
   dstlen--;  // leave one char space for "\,"
   while (*src && dstlen > 0) {
     // Skip over `=expr`.
     if (src[0] == '`' && src[1] == '=') {
-      var = (char_u *)src;
+      var = src;
       src += 2;
       (void)skip_expr(&src);
       if (*src == '`') {
         src++;
       }
-      size_t len = (size_t)(src - (char *)var);
+      size_t len = (size_t)(src - var);
       if (len > (size_t)dstlen) {
         len = (size_t)dstlen;
       }
-      memcpy((char *)dst, (char *)var, len);
+      memcpy(dst, var, len);
       dst += len;
       dstlen -= (int)len;
       continue;
@@ -620,7 +620,7 @@ void expand_env_esc(char_u *restrict srcp, char_u *restrict dst, int dstlen, boo
       // The variable name is copied into dst temporarily, because it may
       // be a string in read-only memory and a NUL needs to be appended.
       if (*src != '~') {  // environment var
-        tail = (char_u *)src + 1;
+        tail = src + 1;
         var = dst;
         int c = dstlen - 1;
 
@@ -649,7 +649,7 @@ void expand_env_esc(char_u *restrict srcp, char_u *restrict dst, int dstlen, boo
           }
 #endif
         *var = NUL;
-        var = (char_u *)vim_getenv((char *)dst);
+        var = vim_getenv(dst);
         mustfree = true;
 #if defined(UNIX)
       }
@@ -657,12 +657,12 @@ void expand_env_esc(char_u *restrict srcp, char_u *restrict dst, int dstlen, boo
       } else if (src[1] == NUL  // home directory
                  || vim_ispathsep(src[1])
                  || vim_strchr(" ,\t\n", src[1]) != NULL) {
-        var = (char_u *)homedir;
-        tail = (char_u *)src + 1;
+        var = homedir;
+        tail = src + 1;
       } else {  // user directory
 #if defined(UNIX)
         // Copy ~user to dst[], so we can put a NUL after it.
-        tail = (char_u *)src;
+        tail = src;
         var = dst;
         int c = dstlen - 1;
         while (c-- > 0
@@ -675,15 +675,15 @@ void expand_env_esc(char_u *restrict srcp, char_u *restrict dst, int dstlen, boo
         // Get the user directory. If this fails the shell is used to expand
         // ~user, which is slower and may fail on old versions of /bin/sh.
         var = (*dst == NUL) ? NULL
-                            : (char_u *)os_get_userdir((char *)dst + 1);
+                            : os_get_userdir(dst + 1);
         mustfree = true;
         if (var == NULL) {
           expand_T xpc;
 
           ExpandInit(&xpc);
           xpc.xp_context = EXPAND_FILES;
-          var = (char_u *)ExpandOne(&xpc, (char *)dst, NULL,
-                                    WILD_ADD_SLASH|WILD_SILENT, WILD_EXPAND_FREE);
+          var = ExpandOne(&xpc, dst, NULL,
+                          WILD_ADD_SLASH|WILD_SILENT, WILD_EXPAND_FREE);
           mustfree = true;
         }
 #else
@@ -710,8 +710,8 @@ void expand_env_esc(char_u *restrict srcp, char_u *restrict dst, int dstlen, boo
 
       // If "var" contains white space, escape it with a backslash.
       // Required for ":e ~/tt" when $HOME includes a space.
-      if (esc && var != NULL && strpbrk((char *)var, " \t") != NULL) {
-        char_u *p = vim_strsave_escaped(var, (char_u *)" \t");
+      if (esc && var != NULL && strpbrk(var, " \t") != NULL) {
+        char *p = (char *)vim_strsave_escaped((char_u *)var, (char_u *)" \t");
 
         if (mustfree) {
           xfree(var);
@@ -721,13 +721,13 @@ void expand_env_esc(char_u *restrict srcp, char_u *restrict dst, int dstlen, boo
       }
 
       if (var != NULL && *var != NUL
-          && (STRLEN(var) + STRLEN(tail) + 1 < (unsigned)dstlen)) {
+          && (strlen(var) + strlen(tail) + 1 < (unsigned)dstlen)) {
         STRCPY(dst, var);
-        dstlen -= (int)STRLEN(var);
-        int c = (int)STRLEN(var);
+        dstlen -= (int)strlen(var);
+        int c = (int)strlen(var);
         // if var[] ends in a path separator and tail[] starts
         // with it, skip a character
-        if (after_pathsep((char *)dst, (char *)dst + c)
+        if (after_pathsep(dst, dst + c)
 #if defined(BACKSLASH_IN_FILENAME)
             && dst[-1] != ':'
 #endif
@@ -735,7 +735,7 @@ void expand_env_esc(char_u *restrict srcp, char_u *restrict dst, int dstlen, boo
           tail++;
         }
         dst += c;
-        src = (char *)tail;
+        src = tail;
         copy_char = false;
       }
       if (mustfree) {
@@ -749,17 +749,17 @@ void expand_env_esc(char_u *restrict srcp, char_u *restrict dst, int dstlen, boo
       // ":edit foo ~ foo".
       at_start = false;
       if (src[0] == '\\' && src[1] != NUL) {
-        *dst++ = (char_u)(*src++);
+        *dst++ = *src++;
         dstlen--;
       } else if ((src[0] == ' ' || src[0] == ',') && !one) {
         at_start = true;
       }
       if (dstlen > 0) {
-        *dst++ = (char_u)(*src++);
+        *dst++ = *src++;
         dstlen--;
 
         if (prefix != NULL
-            && src - prefix_len >= (char *)srcp
+            && src - prefix_len >= srcp
             && STRNCMP(src - prefix_len, prefix, prefix_len) == 0) {
           at_start = true;
         }
diff --git a/src/nvim/os/shell.c b/src/nvim/os/shell.c
index b4bee6e550..c1359d6ece 100644
--- a/src/nvim/os/shell.c
+++ b/src/nvim/os/shell.c
@@ -120,15 +120,15 @@ int os_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, in
 {
   int i;
   size_t len;
-  char_u *p;
+  char *p;
   bool dir;
   char_u *extra_shell_arg = NULL;
   ShellOpts shellopts = kShellOptExpand | kShellOptSilent;
   int j;
-  char_u *tempname;
-  char_u *command;
+  char *tempname;
+  char *command;
   FILE *fd;
-  char_u *buffer;
+  char *buffer;
 #define STYLE_ECHO      0       // use "echo", the default
 #define STYLE_GLOB      1       // use "glob", for csh
 #define STYLE_VIMGLOB   2       // use "vimglob", for Posix sh
@@ -175,7 +175,7 @@ int os_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, in
   }
 
   // get a name for the temp file
-  if ((tempname = (char_u *)vim_tempname()) == NULL) {
+  if ((tempname = vim_tempname()) == NULL) {
     emsg(_(e_notmp));
     return FAIL;
   }
@@ -196,7 +196,7 @@ int os_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, in
       && (len = strlen(pat[0])) > 2
       && *(pat[0] + len - 1) == '`') {
     shell_style = STYLE_BT;
-  } else if ((len = STRLEN(p_sh)) >= 3) {
+  } else if ((len = strlen(p_sh)) >= 3) {
     if (strcmp(p_sh + len - 3, "csh") == 0) {
       shell_style = STYLE_GLOB;
     } else if (strcmp(p_sh + len - 3, "zsh") == 0) {
@@ -211,7 +211,7 @@ int os_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, in
   // Compute the length of the command.  We need 2 extra bytes: for the
   // optional '&' and for the NUL.
   // Worst case: "unset nonomatch; print -N >" plus two is 29
-  len = STRLEN(tempname) + 29;
+  len = strlen(tempname) + 29;
   if (shell_style == STYLE_VIMGLOB) {
     len += strlen(sh_vimglob_func);
   }
@@ -248,7 +248,7 @@ int os_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, in
       STRCPY(command, "(");
     }
     STRCAT(command, pat[0] + 1);                // exclude first backtick
-    p = command + STRLEN(command) - 1;
+    p = command + strlen(command) - 1;
     if (is_fish_shell) {
       *p-- = ';';
       STRCAT(command, " end");
@@ -294,7 +294,7 @@ int os_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, in
       // characters, except inside ``.
       bool intick = false;
 
-      p = command + STRLEN(command);
+      p = command + strlen(command);
       *p++ = ' ';
       for (j = 0; pat[i][j] != NUL; j++) {
         if (pat[i][j] == '`') {
@@ -319,7 +319,7 @@ int os_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, in
         }
 
         // Copy one character.
-        *p++ = (char_u)pat[i][j];
+        *p++ = pat[i][j];
       }
       *p = NUL;
     }
@@ -347,7 +347,7 @@ int os_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, in
   }
 
   // execute the shell command
-  i = call_shell(command, shellopts, extra_shell_arg);
+  i = call_shell((char_u *)command, shellopts, extra_shell_arg);
 
   // When running in the background, give it some time to create the temp
   // file, but don't wait for it to finish.
@@ -358,7 +358,7 @@ int os_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, in
   xfree(command);
 
   if (i) {                         // os_call_shell() failed
-    os_remove((char *)tempname);
+    os_remove(tempname);
     xfree(tempname);
     // With interactive completion, the error message is not printed.
     if (!(flags & EW_SILENT)) {
@@ -377,7 +377,7 @@ int os_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, in
   }
 
   // read the names from the file into memory
-  fd = fopen((char *)tempname, READBIN);
+  fd = fopen(tempname, READBIN);
   if (fd == NULL) {
     // Something went wrong, perhaps a file name with a special char.
     if (!(flags & EW_SILENT)) {
@@ -407,9 +407,9 @@ int os_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, in
   buffer = xmalloc(len + 1);
   // fread() doesn't terminate buffer with NUL;
   // appropriate termination (not always NUL) is done below.
-  size_t readlen = fread((char *)buffer, 1, len, fd);
+  size_t readlen = fread(buffer, 1, len, fd);
   fclose(fd);
-  os_remove((char *)tempname);
+  os_remove(tempname);
   if (readlen != len) {
     // unexpected read error
     semsg(_(e_notread), tempname);
@@ -427,7 +427,7 @@ int os_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, in
       while (*p != ' ' && *p != '\n') {
         p++;
       }
-      p = (char_u *)skipwhite((char *)p);                 // skip to next entry
+      p = skipwhite(p);                 // skip to next entry
     }
     // file names are separated with NL
   } else if (shell_style == STYLE_BT || shell_style == STYLE_VIMGLOB) {
@@ -440,7 +440,7 @@ int os_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, in
       if (*p != NUL) {
         p++;
       }
-      p = (char_u *)skipwhite((char *)p);                 // skip leading white space
+      p = skipwhite(p);                 // skip leading white space
     }
     // file names are separated with NUL
   } else {
@@ -454,7 +454,7 @@ int os_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, in
     if (shell_style == STYLE_PRINT && !did_find_nul) {
       // If there is a NUL, set did_find_nul, else set check_spaces
       buffer[len] = NUL;
-      if (len && (int)STRLEN(buffer) < (int)len) {
+      if (len && (int)strlen(buffer) < (int)len) {
         did_find_nul = true;
       } else {
         check_spaces = true;
@@ -493,7 +493,7 @@ int os_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, in
   // Isolate the individual file names.
   p = buffer;
   for (i = 0; i < *num_file; i++) {
-    (*file)[i] = (char *)p;
+    (*file)[i] = p;
     // Space or NL separates
     if (shell_style == STYLE_ECHO || shell_style == STYLE_BT
         || shell_style == STYLE_VIMGLOB) {
@@ -505,7 +505,7 @@ int os_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, in
         *p = NUL;
       } else {
         *p++ = NUL;
-        p = (char_u *)skipwhite((char *)p);                       // skip to next entry
+        p = skipwhite(p);                       // skip to next entry
       }
     } else {          // NUL separates
       while (*p && p < buffer + len) {          // skip entry
@@ -537,9 +537,9 @@ int os_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, in
     p = xmalloc(strlen((*file)[i]) + 1 + dir);
     STRCPY(p, (*file)[i]);
     if (dir) {
-      add_pathsep((char *)p);             // add '/' to a directory name
+      add_pathsep(p);             // add '/' to a directory name
     }
-    (*file)[j++] = (char *)p;
+    (*file)[j++] = p;
   }
   xfree(buffer);
   *num_file = j;
diff --git a/src/nvim/path.c b/src/nvim/path.c
index 68c4b596d7..49deb821be 100644
--- a/src/nvim/path.c
+++ b/src/nvim/path.c
@@ -628,26 +628,26 @@ static size_t do_path_expand(garray_T *gap, const char *path, size_t wildoff, in
 
   // Make room for file name.  When doing encoding conversion the actual
   // length may be quite a bit longer, thus use the maximum possible length.
-  char_u *buf = xmalloc(MAXPATHL);
+  char *buf = xmalloc(MAXPATHL);
 
   // Find the first part in the path name that contains a wildcard.
   // When EW_ICASE is set every letter is considered to be a wildcard.
   // Copy it into "buf", including the preceding characters.
-  char_u *p = buf;
-  char_u *s = buf;
-  char_u *e = NULL;
-  const char_u *path_end = (char_u *)path;
+  char *p = buf;
+  char *s = buf;
+  char *e = NULL;
+  const char *path_end = path;
   while (*path_end != NUL) {
     // May ignore a wildcard that has a backslash before it; it will
     // be removed by rem_backslash() or file_pat_to_reg_pat() below.
-    if (path_end >= (char_u *)path + wildoff && rem_backslash((char *)path_end)) {
+    if (path_end >= path + wildoff && rem_backslash((char *)path_end)) {
       *p++ = *path_end++;
     } else if (vim_ispathsep_nocolon(*path_end)) {
       if (e != NULL) {
         break;
       }
       s = p + 1;
-    } else if (path_end >= (char_u *)path + wildoff
+    } else if (path_end >= path + wildoff
                && (vim_strchr("*?[{~$", *path_end) != NULL
 #ifndef MSWIN
                    || (!p_fic && (flags & EW_ICASE) && mb_isalpha(utf_ptr2char((char *)path_end)))
@@ -667,7 +667,7 @@ static size_t do_path_expand(garray_T *gap, const char *path, size_t wildoff, in
   // Remove backslashes between "wildoff" and the start of the wildcard
   // component.
   for (p = buf + wildoff; p < s; p++) {
-    if (rem_backslash((char *)p)) {
+    if (rem_backslash(p)) {
       STRMOVE(p, p + 1);
       e--;
       s--;
@@ -683,7 +683,7 @@ static size_t do_path_expand(garray_T *gap, const char *path, size_t wildoff, in
 
   // convert the file pattern to a regexp pattern
   int starts_with_dot = *s == '.';
-  char *pat = file_pat_to_reg_pat((char *)s, (char *)e, NULL, false);
+  char *pat = file_pat_to_reg_pat(s, e, NULL, false);
   if (pat == NULL) {
     xfree(buf);
     return 0;
@@ -717,13 +717,13 @@ static size_t do_path_expand(garray_T *gap, const char *path, size_t wildoff, in
       && *path_end == '/') {
     STRCPY(s, path_end + 1);
     stardepth++;
-    (void)do_path_expand(gap, (char *)buf, (size_t)(s - buf), flags, true);
+    (void)do_path_expand(gap, buf, (size_t)(s - buf), flags, true);
     stardepth--;
   }
   *s = NUL;
 
   Directory dir;
-  char *dirpath = (*buf == NUL ? "." : (char *)buf);
+  char *dirpath = (*buf == NUL ? "." : buf);
   if (os_file_is_readable(dirpath) && os_scandir(&dir, dirpath)) {
     // Find all matching entries.
     char *name;
@@ -738,7 +738,7 @@ static size_t do_path_expand(garray_T *gap, const char *path, size_t wildoff, in
               || ((flags & EW_NOTWILD)
                   && path_fnamencmp(path + (s - buf), name, (size_t)(e - s)) == 0))) {
         STRCPY(s, name);
-        len = STRLEN(buf);
+        len = strlen(buf);
 
         if (starstar && stardepth < 100) {
           // For "**" in the pattern first go deeper in the tree to
@@ -746,27 +746,27 @@ static size_t do_path_expand(garray_T *gap, const char *path, size_t wildoff, in
           STRCPY(buf + len, "/**");  // NOLINT
           STRCPY(buf + len + 3, path_end);
           stardepth++;
-          (void)do_path_expand(gap, (char *)buf, len + 1, flags, true);
+          (void)do_path_expand(gap, buf, len + 1, flags, true);
           stardepth--;
         }
 
         STRCPY(buf + len, path_end);
-        if (path_has_exp_wildcard(path_end)) {      // handle more wildcards
+        if (path_has_exp_wildcard((char_u *)path_end)) {      // handle more wildcards
           // need to expand another component of the path
           // remove backslashes for the remaining components only
-          (void)do_path_expand(gap, (char *)buf, len + 1, flags, false);
+          (void)do_path_expand(gap, buf, len + 1, flags, false);
         } else {
           FileInfo file_info;
 
           // no more wildcards, check if there is a match
           // remove backslashes for the remaining components only
           if (*path_end != NUL) {
-            backslash_halve((char *)buf + len + 1);
+            backslash_halve(buf + len + 1);
           }
           // add existing file or symbolic link
           if ((flags & EW_ALLLINKS)
-              ? os_fileinfo_link((char *)buf, &file_info)
-              : os_path_exists((char *)buf)) {
+              ? os_fileinfo_link(buf, &file_info)
+              : os_path_exists(buf)) {
             addfile(gap, buf, flags);
           }
         }
@@ -839,7 +839,7 @@ static bool is_unique(char *maybe_unique, garray_T *gap, int i)
 //
 // TODO(vim): handle upward search (;) and path limiter (**N) notations by
 // expanding each into their equivalent path(s).
-static void expand_path_option(char_u *curdir, garray_T *gap)
+static void expand_path_option(char *curdir, garray_T *gap)
 {
   char_u *path_option = *curbuf->b_p_path == NUL ? p_path : (char_u *)curbuf->b_p_path;
   char *buf = xmalloc(MAXPATHL);
@@ -872,7 +872,7 @@ static void expand_path_option(char_u *curdir, garray_T *gap)
       continue;  // URL can't be used here
     } else if (!path_is_absolute((char_u *)buf)) {
       // Expand relative path to their full path equivalent
-      size_t len = STRLEN(curdir);
+      size_t len = strlen(curdir);
       if (len + strlen(buf) + 3 > MAXPATHL) {
         continue;
       }
@@ -927,10 +927,10 @@ static char_u *get_path_cutoff(char_u *fname, garray_T *gap)
   return cutoff;
 }
 
-// Sorts, removes duplicates and modifies all the fullpath names in "gap" so
-// that they are unique with respect to each other while conserving the part
-// that matches the pattern. Beware, this is at least O(n^2) wrt "gap->ga_len".
-static void uniquefy_paths(garray_T *gap, char_u *pattern)
+/// Sorts, removes duplicates and modifies all the fullpath names in "gap" so
+/// that they are unique with respect to each other while conserving the part
+/// that matches the pattern. Beware, this is at least O(n^2) wrt "gap->ga_len".
+static void uniquefy_paths(garray_T *gap, char *pattern)
 {
   char **fnames = gap->ga_data;
   bool sort_again = false;
@@ -945,7 +945,7 @@ static void uniquefy_paths(garray_T *gap, char_u *pattern)
   // We need to prepend a '*' at the beginning of file_pattern so that the
   // regex matches anywhere in the path. FIXME: is this valid for all
   // possible patterns?
-  size_t len = STRLEN(pattern);
+  size_t len = strlen(pattern);
   char *file_pattern = xmalloc(len + 2);
   file_pattern[0] = '*';
   file_pattern[1] = NUL;
@@ -965,7 +965,7 @@ static void uniquefy_paths(garray_T *gap, char_u *pattern)
 
   char *curdir = xmalloc(MAXPATHL);
   os_dirname((char_u *)curdir, MAXPATHL);
-  expand_path_option((char_u *)curdir, &path_ga);
+  expand_path_option(curdir, &path_ga);
 
   in_curdir = xcalloc((size_t)gap->ga_len, sizeof(char_u *));
 
@@ -976,7 +976,7 @@ static void uniquefy_paths(garray_T *gap, char_u *pattern)
     char *pathsep_p;
     char *path_cutoff;
 
-    len = STRLEN(path);
+    len = strlen(path);
     is_in_curdir = path_fnamencmp(curdir, path, (size_t)(dir_end - path)) == 0
                    && curdir[dir_end - path] == NUL;
     if (is_in_curdir) {
@@ -1026,7 +1026,7 @@ static void uniquefy_paths(garray_T *gap, char_u *pattern)
       if (short_name != NULL && short_name > path + 1) {
         STRCPY(path, ".");
         add_pathsep(path);
-        STRMOVE(path + STRLEN(path), short_name);
+        STRMOVE(path + strlen(path), short_name);
       }
     }
     os_breakcheck();
@@ -1121,7 +1121,7 @@ static int expand_in_path(garray_T *const gap, char_u *const pattern, const int
   os_dirname(curdir, MAXPATHL);
 
   ga_init(&path_ga, (int)sizeof(char_u *), 1);
-  expand_path_option(curdir, &path_ga);
+  expand_path_option((char *)curdir, &path_ga);
   xfree(curdir);
   if (GA_EMPTY(&path_ga)) {
     return 0;
@@ -1232,7 +1232,7 @@ int gen_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, i
   // For `=expr` do use the internal function.
   for (int i = 0; i < num_pat; i++) {
     if (has_special_wildchar((char_u *)pat[i])
-        && !(vim_backtick((char_u *)pat[i]) && pat[i][1] == '=')) {
+        && !(vim_backtick(pat[i]) && pat[i][1] == '=')) {
       return os_expand_wildcards(num_pat, pat, num_file, file, flags);
     }
   }
@@ -1247,7 +1247,7 @@ int gen_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, i
     add_pat = -1;
     p = (char_u *)pat[i];
 
-    if (vim_backtick(p)) {
+    if (vim_backtick((char *)p)) {
       add_pat = expand_backtick(&ga, (char *)p, flags);
       if (add_pat == -1) {
         recursive = false;
@@ -1311,9 +1311,9 @@ int gen_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, i
       // When EW_NOTFOUND is used, always add files and dirs.  Makes
       // "vim c:/" work.
       if (flags & EW_NOTFOUND) {
-        addfile(&ga, t, flags | EW_DIR | EW_FILE);
+        addfile(&ga, (char *)t, flags | EW_DIR | EW_FILE);
       } else {
-        addfile(&ga, t, flags);
+        addfile(&ga, (char *)t, flags);
       }
 
       if (t != p) {
@@ -1322,7 +1322,7 @@ int gen_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, i
     }
 
     if (did_expand_in_path && !GA_EMPTY(&ga) && (flags & EW_PATH)) {
-      uniquefy_paths(&ga, p);
+      uniquefy_paths(&ga, (char *)p);
     }
     if (p != (char_u *)pat[i]) {
       xfree(p);
@@ -1349,10 +1349,10 @@ void FreeWild(int count, char **files)
   xfree(files);
 }
 
-/// Return true if we can expand this backtick thing here.
-static int vim_backtick(char_u *p)
+/// @return  true if we can expand this backtick thing here.
+static int vim_backtick(char *p)
 {
-  return *p == '`' && *(p + 1) != NUL && *(p + STRLEN(p) - 1) == '`';
+  return *p == '`' && *(p + 1) != NUL && *(p + strlen(p) - 1) == '`';
 }
 
 /// Expand an item in `backticks` by executing it as a command.
@@ -1391,7 +1391,7 @@ static int expand_backtick(garray_T *gap, char *pat, int flags)
     if (p > cmd) {
       char i = *p;
       *p = NUL;
-      addfile(gap, (char_u *)cmd, flags);
+      addfile(gap, cmd, flags);
       *p = i;
       cnt++;
     }
@@ -1446,7 +1446,7 @@ void slash_adjust(char_u *p)
 /// EW_ALLLINKS add symlink also when the referred file does not exist
 ///
 /// @param f  filename
-void addfile(garray_T *gap, char_u *f, int flags)
+void addfile(garray_T *gap, char *f, int flags)
 {
   bool isdir;
   FileInfo file_info;
@@ -1454,8 +1454,8 @@ void addfile(garray_T *gap, char_u *f, int flags)
   // if the file/dir/link doesn't exist, may not add it
   if (!(flags & EW_NOTFOUND)
       && ((flags & EW_ALLLINKS)
-          ? !os_fileinfo_link((char *)f, &file_info)
-          : !os_path_exists((char *)f))) {
+          ? !os_fileinfo_link(f, &file_info)
+          : !os_path_exists(f))) {
     return;
   }
 
@@ -1466,7 +1466,7 @@ void addfile(garray_T *gap, char_u *f, int flags)
   }
 #endif
 
-  isdir = os_isdir((char *)f);
+  isdir = os_isdir(f);
   if ((isdir && !(flags & EW_DIR)) || (!isdir && !(flags & EW_FILE))) {
     return;
   }
@@ -1474,11 +1474,11 @@ void addfile(garray_T *gap, char_u *f, int flags)
   // If the file isn't executable, may not add it.  Do accept directories.
   // When invoked from expand_shellcmd() do not use $PATH.
   if (!isdir && (flags & EW_EXEC)
-      && !os_can_exe((char *)f, NULL, !(flags & EW_SHELLCMD))) {
+      && !os_can_exe(f, NULL, !(flags & EW_SHELLCMD))) {
     return;
   }
 
-  char_u *p = xmalloc(STRLEN(f) + 1 + isdir);
+  char_u *p = xmalloc(strlen(f) + 1 + isdir);
 
   STRCPY(p, f);
 #ifdef BACKSLASH_IN_FILENAME
diff --git a/src/nvim/profile.c b/src/nvim/profile.c
index d54deaf983..f3a55696aa 100644
--- a/src/nvim/profile.c
+++ b/src/nvim/profile.c
@@ -742,7 +742,7 @@ static void script_dump_profile(FILE *fd)
         // Keep going till the end of file, so that trailing
         // continuation lines are listed.
         for (int i = 0;; i++) {
-          if (vim_fgets((char_u *)IObuff, IOSIZE, sfd)) {
+          if (vim_fgets(IObuff, IOSIZE, sfd)) {
             break;
           }
           // When a line has been truncated, append NL, taking care
diff --git a/src/nvim/quickfix.c b/src/nvim/quickfix.c
index cadbab91f4..f0a983b80f 100644
--- a/src/nvim/quickfix.c
+++ b/src/nvim/quickfix.c
@@ -2784,7 +2784,7 @@ static void qf_jump_goto_line(linenr_T qf_lnum, int qf_col, char qf_viscol, char
     // Move the cursor to the first line in the buffer
     pos_T save_cursor = curwin->w_cursor;
     curwin->w_cursor.lnum = 0;
-    if (!do_search(NULL, '/', '/', (char_u *)qf_pattern, (long)1, SEARCH_KEEP, NULL)) {
+    if (!do_search(NULL, '/', '/', qf_pattern, (long)1, SEARCH_KEEP, NULL)) {
       curwin->w_cursor = save_cursor;
     }
   }
@@ -6993,7 +6993,7 @@ static void hgr_search_file(qf_list_T *qfl, char *fname, regmatch_T *p_regmatch)
   }
 
   linenr_T lnum = 1;
-  while (!vim_fgets((char_u *)IObuff, IOSIZE, fd) && !got_int) {
+  while (!vim_fgets(IObuff, IOSIZE, fd) && !got_int) {
     char *line = (char *)IObuff;
 
     if (vim_regexec(p_regmatch, line, (colnr_T)0)) {
diff --git a/src/nvim/runtime.c b/src/nvim/runtime.c
index db8dc04907..8fafe4b6b9 100644
--- a/src/nvim/runtime.c
+++ b/src/nvim/runtime.c
@@ -2043,7 +2043,7 @@ int do_source(char *fname, int check_other, int is_vimrc)
   } else {
     // Read the first line so we can check for a UTF-8 BOM.
     firstline = (uint8_t *)getsourceline(0, (void *)&cookie, 0, true);
-    if (firstline != NULL && STRLEN(firstline) >= 3 && firstline[0] == 0xef
+    if (firstline != NULL && strlen((char *)firstline) >= 3 && firstline[0] == 0xef
         && firstline[1] == 0xbb && firstline[2] == 0xbf) {
       // Found BOM; setup conversion, skip over BOM and recode the line.
       convert_setup(&cookie.conv, "utf-8", p_enc);
diff --git a/src/nvim/search.c b/src/nvim/search.c
index 378306b8d7..cb31da3e87 100644
--- a/src/nvim/search.c
+++ b/src/nvim/search.c
@@ -156,7 +156,7 @@ int search_regcomp(char_u *pat, int pat_save, int pat_use, int options, regmmatc
       rc_did_emsg = true;
       return FAIL;
     }
-    pat = spats[i].pat;
+    pat = (char_u *)spats[i].pat;
     magic = spats[i].magic;
     no_smartcase = spats[i].no_scs;
   } else if (options & SEARCH_HIS) {      // put new pattern in history
@@ -205,9 +205,9 @@ char_u *get_search_pat(void)
 
 void save_re_pat(int idx, char *pat, int magic)
 {
-  if (spats[idx].pat != (char_u *)pat) {
+  if (spats[idx].pat != pat) {
     free_spat(&spats[idx]);
-    spats[idx].pat = (char_u *)xstrdup(pat);
+    spats[idx].pat = xstrdup(pat);
     spats[idx].magic = magic;
     spats[idx].no_scs = no_smartcase;
     spats[idx].timestamp = os_time();
@@ -230,11 +230,11 @@ void save_search_patterns(void)
   if (save_level++ == 0) {
     saved_spats[0] = spats[0];
     if (spats[0].pat != NULL) {
-      saved_spats[0].pat = (char_u *)xstrdup((char *)spats[0].pat);
+      saved_spats[0].pat = xstrdup(spats[0].pat);
     }
     saved_spats[1] = spats[1];
     if (spats[1].pat != NULL) {
-      saved_spats[1].pat = (char_u *)xstrdup((char *)spats[1].pat);
+      saved_spats[1].pat = xstrdup(spats[1].pat);
     }
     saved_spats_last_idx = last_idx;
     saved_spats_no_hlsearch = no_hlsearch;
@@ -301,7 +301,7 @@ void save_last_search_pattern(void)
 
   saved_last_search_spat = spats[RE_SEARCH];
   if (spats[RE_SEARCH].pat != NULL) {
-    saved_last_search_spat.pat = (char_u *)xstrdup((char *)spats[RE_SEARCH].pat);
+    saved_last_search_spat.pat = xstrdup(spats[RE_SEARCH].pat);
   }
   saved_last_idx = last_idx;
   saved_no_hlsearch = no_hlsearch;
@@ -344,7 +344,7 @@ static void restore_incsearch_state(void)
 
 char_u *last_search_pattern(void)
 {
-  return spats[RE_SEARCH].pat;
+  return (char_u *)spats[RE_SEARCH].pat;
 }
 
 /// Return true when case should be ignored for search pattern "pat".
@@ -440,7 +440,7 @@ void set_csearch_until(int t_cmd)
 
 char_u *last_search_pat(void)
 {
-  return spats[last_idx].pat;
+  return (char_u *)spats[last_idx].pat;
 }
 
 // Reset search direction to forward.  For "gd" and "gD" commands.
@@ -459,7 +459,7 @@ void set_last_search_pat(const char_u *s, int idx, int magic, int setlast)
   if (*s == NUL) {
     spats[idx].pat = NULL;
   } else {
-    spats[idx].pat = (char_u *)xstrdup((char *)s);
+    spats[idx].pat = xstrdup((char *)s);
   }
   spats[idx].timestamp = os_time();
   spats[idx].additional_data = NULL;
@@ -479,7 +479,7 @@ void set_last_search_pat(const char_u *s, int idx, int magic, int setlast)
     if (spats[idx].pat == NULL) {
       saved_spats[idx].pat = NULL;
     } else {
-      saved_spats[idx].pat = (char_u *)xstrdup((char *)spats[idx].pat);
+      saved_spats[idx].pat = xstrdup(spats[idx].pat);
     }
     saved_spats_last_idx = last_idx;
   }
@@ -532,7 +532,7 @@ int searchit(win_T *win, buf_T *buf, pos_T *pos, pos_T *end_pos, Direction dir,
   int found;
   linenr_T lnum;                // no init to shut up Apollo cc
   regmmatch_T regmatch;
-  char_u *ptr;
+  char *ptr;
   colnr_T matchcol;
   lpos_T endpos;
   lpos_T matchpos;
@@ -576,11 +576,11 @@ int searchit(win_T *win, buf_T *buf, pos_T *pos, pos_T *end_pos, Direction dir,
                && pos->lnum <= buf->b_ml.ml_line_count
                && pos->col < MAXCOL - 2) {
       // Watch out for the "col" being MAXCOL - 2, used in a closed fold.
-      ptr = (char_u *)ml_get_buf(buf, pos->lnum, false);
-      if ((int)STRLEN(ptr) <= pos->col) {
+      ptr = ml_get_buf(buf, pos->lnum, false);
+      if ((int)strlen(ptr) <= pos->col) {
         start_char_len = 1;
       } else {
-        start_char_len = utfc_ptr2len((char *)ptr + pos->col);
+        start_char_len = utfc_ptr2len(ptr + pos->col);
       }
     } else {
       start_char_len = 1;
@@ -645,9 +645,9 @@ int searchit(win_T *win, buf_T *buf, pos_T *pos, pos_T *end_pos, Direction dir,
           submatch = first_submatch(&regmatch);
           // "lnum" may be past end of buffer for "\n\zs".
           if (lnum + matchpos.lnum > buf->b_ml.ml_line_count) {
-            ptr = (char_u *)"";
+            ptr = "";
           } else {
-            ptr = (char_u *)ml_get_buf(buf, lnum + matchpos.lnum, false);
+            ptr = ml_get_buf(buf, lnum + matchpos.lnum, false);
           }
 
           // Forward search in the first line: match should be after
@@ -686,7 +686,7 @@ 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((char *)ptr + matchcol);
+                matchcol += utfc_ptr2len(ptr + matchcol);
               }
 
               if (matchcol == 0 && (options & SEARCH_START)) {
@@ -716,7 +716,7 @@ int searchit(win_T *win, buf_T *buf, pos_T *pos, pos_T *end_pos, Direction dir,
               }
               // Need to get the line pointer again, a multi-line search may
               // have made it invalid.
-              ptr = (char_u *)ml_get_buf(buf, lnum, false);
+              ptr = ml_get_buf(buf, lnum, false);
             }
             if (!match_ok) {
               continue;
@@ -769,7 +769,7 @@ 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((char *)ptr + matchcol);
+                  matchcol += utfc_ptr2len(ptr + matchcol);
                 }
               } else {
                 // Stop when the match is in a next line.
@@ -778,7 +778,7 @@ 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((char *)ptr + matchcol);
+                  matchcol += utfc_ptr2len(ptr + matchcol);
                 }
               }
               if (ptr[matchcol] == NUL
@@ -798,7 +798,7 @@ int searchit(win_T *win, buf_T *buf, pos_T *pos, pos_T *end_pos, Direction dir,
               }
               // Need to get the line pointer again, a
               // multi-line search may have made it invalid.
-              ptr = (char_u *)ml_get_buf(buf, lnum + matchpos.lnum, false);
+              ptr = ml_get_buf(buf, lnum + matchpos.lnum, false);
             }
 
             // If there is only a match after the cursor, skip
@@ -826,8 +826,8 @@ int searchit(win_T *win, buf_T *buf, pos_T *pos, pos_T *end_pos, Direction dir,
             } else {
               pos->col--;
               if (pos->lnum <= buf->b_ml.ml_line_count) {
-                ptr = (char_u *)ml_get_buf(buf, pos->lnum, false);
-                pos->col -= utf_head_off((char *)ptr, (char *)ptr + pos->col);
+                ptr = ml_get_buf(buf, pos->lnum, false);
+                pos->col -= utf_head_off(ptr, ptr + pos->col);
               }
             }
             if (end_pos != NULL) {
@@ -1000,19 +1000,19 @@ static int first_submatch(regmmatch_T *rp)
 /// @param sia           optional arguments or NULL
 ///
 /// @return              0 for failure, 1 for found, 2 for found and line offset added.
-int do_search(oparg_T *oap, int dirc, int search_delim, char_u *pat, long count, int options,
+int do_search(oparg_T *oap, int dirc, int search_delim, char *pat, long count, int options,
               searchit_arg_T *sia)
 {
   pos_T pos;                    // position of the last match
-  char_u *searchstr;
+  char *searchstr;
   struct soffset old_off;
   int retval;                   // Return value
-  char_u *p;
+  char *p;
   long c;
-  char_u *dircp;
+  char *dircp;
   char *strcopy = NULL;
   char_u *ps;
-  char_u *msgbuf = NULL;
+  char *msgbuf = NULL;
   size_t len;
   bool has_offset = false;
 
@@ -1078,7 +1078,7 @@ int do_search(oparg_T *oap, int dirc, int search_delim, char_u *pat, long count,
         }
       } else {
         // make search_regcomp() use spats[RE_SEARCH].pat
-        searchstr = (char_u *)"";
+        searchstr = "";
       }
     }
 
@@ -1086,12 +1086,12 @@ int do_search(oparg_T *oap, int dirc, int search_delim, char_u *pat, long count,
       // Find end of regular expression.
       // If there is a matching '/' or '?', toss it.
       ps = (char_u *)strcopy;
-      p = (char_u *)skip_regexp_ex((char *)pat, search_delim, p_magic, &strcopy, NULL);
+      p = skip_regexp_ex(pat, search_delim, p_magic, &strcopy, NULL);
       if (strcopy != (char *)ps) {
         // made a copy of "pat" to change "\?" to "?"
-        searchcmdlen += (int)(STRLEN(pat) - strlen(strcopy));
-        pat = (char_u *)strcopy;
-        searchstr = (char_u *)strcopy;
+        searchcmdlen += (int)(strlen(pat) - strlen(strcopy));
+        pat = strcopy;
+        searchstr = strcopy;
       }
       if (*p == search_delim) {
         dircp = p;              // remember where we put the NUL
@@ -1116,7 +1116,7 @@ int do_search(oparg_T *oap, int dirc, int search_delim, char_u *pat, long count,
       if (ascii_isdigit(*p) || *p == '+' || *p == '-') {      // got an offset
         // 'nr' or '+nr' or '-nr'
         if (ascii_isdigit(*p) || ascii_isdigit(*(p + 1))) {
-          spats[0].off.off = atol((char *)p);
+          spats[0].off.off = atol(p);
         } else if (*p == '-') {                      // single '-'
           spats[0].off.off = -1;
         } else {  // single '+'
@@ -1136,8 +1136,8 @@ int do_search(oparg_T *oap, int dirc, int search_delim, char_u *pat, long count,
 
     if ((options & SEARCH_ECHO) && messaging() && !msg_silent
         && (!cmd_silent || !shortmess(SHM_SEARCHCOUNT))) {
-      char_u *trunc;
-      char_u off_buf[40];
+      char *trunc;
+      char off_buf[40];
       size_t off_len = 0;
 
       // Compute msg_row early.
@@ -1147,7 +1147,7 @@ int do_search(oparg_T *oap, int dirc, int search_delim, char_u *pat, long count,
       if (!cmd_silent
           && (spats[0].off.line || spats[0].off.end || spats[0].off.off)) {
         p = off_buf;  // -V507
-        *p++ = (char_u)dirc;
+        *p++ = (char)dirc;
         if (spats[0].off.end) {
           *p++ = 'e';
         } else if (!spats[0].off.line) {
@@ -1158,10 +1158,10 @@ int do_search(oparg_T *oap, int dirc, int search_delim, char_u *pat, long count,
         }
         *p = NUL;
         if (spats[0].off.off != 0 || spats[0].off.line) {
-          snprintf((char *)p, sizeof(off_buf) - 1 - (size_t)(p - off_buf),
+          snprintf(p, sizeof(off_buf) - 1 - (size_t)(p - off_buf),
                    "%" PRId64, spats[0].off.off);
         }
-        off_len = STRLEN(off_buf);
+        off_len = strlen(off_buf);
       }
 
       if (*searchstr == NUL) {
@@ -1184,12 +1184,12 @@ int do_search(oparg_T *oap, int dirc, int search_delim, char_u *pat, long count,
           // Use up to 'showcmd' column.
           len = (size_t)((Rows - msg_row - 1) * Columns + sc_col - 1);
         }
-        if (len < STRLEN(p) + off_len + SEARCH_STAT_BUF_LEN + 3) {
-          len = STRLEN(p) + off_len + SEARCH_STAT_BUF_LEN + 3;
+        if (len < strlen(p) + off_len + SEARCH_STAT_BUF_LEN + 3) {
+          len = strlen(p) + off_len + SEARCH_STAT_BUF_LEN + 3;
         }
       } else {
         // Reserve enough space for the search pattern + offset.
-        len = STRLEN(p) + off_len + 3;
+        len = strlen(p) + off_len + 3;
       }
 
       xfree(msgbuf);
@@ -1200,19 +1200,19 @@ int do_search(oparg_T *oap, int dirc, int search_delim, char_u *pat, long count,
       // do not fill the msgbuf buffer, if cmd_silent is set, leave it
       // empty for the search_stat feature.
       if (!cmd_silent) {
-        msgbuf[0] = (char_u)dirc;
-        if (utf_iscomposing(utf_ptr2char((char *)p))) {
+        msgbuf[0] = (char)dirc;
+        if (utf_iscomposing(utf_ptr2char(p))) {
           // Use a space to draw the composing char on.
           msgbuf[1] = ' ';
-          memmove(msgbuf + 2, p, STRLEN(p));
+          memmove(msgbuf + 2, p, strlen(p));
         } else {
-          memmove(msgbuf + 1, p, STRLEN(p));
+          memmove(msgbuf + 1, p, strlen(p));
         }
         if (off_len > 0) {
-          memmove(msgbuf + STRLEN(p) + 1, off_buf, off_len);
+          memmove(msgbuf + strlen(p) + 1, off_buf, off_len);
         }
 
-        trunc = (char_u *)msg_strtrunc((char *)msgbuf, true);
+        trunc = msg_strtrunc(msgbuf, true);
         if (trunc != NULL) {
           xfree(msgbuf);
           msgbuf = trunc;
@@ -1223,14 +1223,14 @@ int do_search(oparg_T *oap, int dirc, int search_delim, char_u *pat, long count,
         // it would be blanked out again very soon.  Show it on the
         // left, but do reverse the text.
         if (curwin->w_p_rl && *curwin->w_p_rlc == 's') {
-          char_u *r = (char_u *)reverse_text(trunc != NULL ? (char *)trunc : (char *)msgbuf);
+          char *r = reverse_text(trunc != NULL ? trunc : msgbuf);
           xfree(msgbuf);
           msgbuf = r;
           // move reversed text to beginning of buffer
           while (*r == ' ') {
             r++;
           }
-          size_t pat_len = (size_t)(msgbuf + STRLEN(msgbuf) - r);
+          size_t pat_len = (size_t)(msgbuf + strlen(msgbuf) - r);
           memmove(msgbuf, r, pat_len);
           // overwrite old text
           if ((size_t)(r - msgbuf) >= pat_len) {
@@ -1239,7 +1239,7 @@ int do_search(oparg_T *oap, int dirc, int search_delim, char_u *pat, long count,
             memset(msgbuf + pat_len, ' ', (size_t)(r - msgbuf));
           }
         }
-        msg_outtrans((char *)msgbuf);
+        msg_outtrans(msgbuf);
         msg_clr_eos();
         msg_check();
 
@@ -1279,7 +1279,7 @@ int do_search(oparg_T *oap, int dirc, int search_delim, char_u *pat, long count,
     }
 
     c = searchit(curwin, curbuf, &pos, NULL, dirc == '/' ? FORWARD : BACKWARD,
-                 searchstr, count,
+                 (char_u *)searchstr, count,
                  (spats[0].off.end * SEARCH_END
                   + (options
                      & (SEARCH_KEEP + SEARCH_PEEK + SEARCH_HIS + SEARCH_MSG
@@ -1288,7 +1288,7 @@ int do_search(oparg_T *oap, int dirc, int search_delim, char_u *pat, long count,
                  RE_LAST, sia);
 
     if (dircp != NULL) {
-      *dircp = (char_u)search_delim;  // restore second '/' or '?' for normal_cmd()
+      *dircp = (char)search_delim;  // restore second '/' or '?' for normal_cmd()
     }
 
     if (!shortmess(SHM_SEARCH)
@@ -1375,7 +1375,7 @@ int do_search(oparg_T *oap, int dirc, int search_delim, char_u *pat, long count,
       break;
     }
 
-    dirc = *++pat;
+    dirc = (uint8_t)(*++pat);
     search_delim = dirc;
     if (dirc != '?' && dirc != '/') {
       retval = 0;
@@ -1480,7 +1480,7 @@ int searchc(cmdarg_T *cap, int t_cmd)
   int dir = cap->arg;                   // true for searching forward
   long count = cap->count1;             // repeat count
   int col;
-  char_u *p;
+  char *p;
   int len;
   bool stop = true;
 
@@ -1526,14 +1526,14 @@ int searchc(cmdarg_T *cap, int t_cmd)
     cap->oap->inclusive = true;
   }
 
-  p = (char_u *)get_cursor_line_ptr();
+  p = get_cursor_line_ptr();
   col = curwin->w_cursor.col;
-  len = (int)STRLEN(p);
+  len = (int)strlen(p);
 
   while (count--) {
     for (;;) {
       if (dir > 0) {
-        col += utfc_ptr2len((char *)p + col);
+        col += utfc_ptr2len(p + col);
         if (col >= len) {
           return FAIL;
         }
@@ -1541,7 +1541,7 @@ int searchc(cmdarg_T *cap, int t_cmd)
         if (col == 0) {
           return FAIL;
         }
-        col -= utf_head_off((char *)p, (char *)p + col - 1) + 1;
+        col -= utf_head_off(p, p + col - 1) + 1;
       }
       if (lastc_bytelen == 1) {
         if (p[col] == c && stop) {
@@ -1562,7 +1562,7 @@ int searchc(cmdarg_T *cap, int t_cmd)
       col += lastc_bytelen - 1;
     } else {
       // To previous char, which may be multi-byte.
-      col -= utf_head_off((char *)p, (char *)p + col);
+      col -= utf_head_off(p, p + col);
     }
   }
   curwin->w_cursor.col = col;
@@ -1699,7 +1699,7 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
   bool backwards = false;               // init for gcc
   bool raw_string = false;              // search for raw string
   bool inquote = false;                 // true when inside quotes
-  char_u *ptr;
+  char *ptr;
   int hash_dir = 0;                     // Direction searched for # things
   int comment_dir = 0;                  // Direction searched for comments
   int traveled = 0;                     // how far we've searched so far
@@ -1712,7 +1712,7 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
 
   pos = curwin->w_cursor;
   pos.coladd = 0;
-  char_u *linep = (char_u *)ml_get(pos.lnum);     // pointer to current line
+  char *linep = ml_get(pos.lnum);     // pointer to current line
 
   // vi compatible matching
   bool cpo_match = (vim_strchr(p_cpo, CPO_MATCH) != NULL);
@@ -1759,9 +1759,9 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
       // Only check for special things when 'cpo' doesn't have '%'.
       if (!cpo_match) {
         // Are we before or at #if, #else etc.?
-        ptr = (char_u *)skipwhite((char *)linep);
+        ptr = skipwhite(linep);
         if (*ptr == '#' && pos.col <= (colnr_T)(ptr - linep)) {
-          ptr = (char_u *)skipwhite((char *)ptr + 1);
+          ptr = skipwhite(ptr + 1);
           if (STRNCMP(ptr, "if", 2) == 0
               || STRNCMP(ptr, "endif", 5) == 0
               || STRNCMP(ptr, "el", 2) == 0) {
@@ -1798,7 +1798,7 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
           pos.col--;
         }
         for (;;) {
-          initc = utf_ptr2char((char *)linep + pos.col);
+          initc = utf_ptr2char(linep + pos.col);
           if (initc == NUL) {
             break;
           }
@@ -1807,11 +1807,11 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
           if (findc) {
             break;
           }
-          pos.col += utfc_ptr2len((char *)linep + pos.col);
+          pos.col += utfc_ptr2len(linep + pos.col);
         }
         if (!findc) {
           // no brace in the line, maybe use "  #if" then
-          if (!cpo_match && *skipwhite((char *)linep) == '#') {
+          if (!cpo_match && *skipwhite(linep) == '#') {
             hash_dir = 1;
           } else {
             return NULL;
@@ -1821,7 +1821,7 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
 
           // Set "match_escaped" if there are an odd number of
           // backslashes.
-          for (col = pos.col; check_prevcol(linep, col, '\\', &col);) {
+          for (col = pos.col; check_prevcol((char_u *)linep, col, '\\', &col);) {
             bslcnt++;
           }
           match_escaped = (bslcnt & 1);
@@ -1834,7 +1834,7 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
         oap->motion_type = kMTLineWise;  // Linewise for this case only
       }
       if (initc != '#') {
-        ptr = (char_u *)skipwhite(skipwhite((char *)linep) + 1);
+        ptr = skipwhite(skipwhite(linep) + 1);
         if (STRNCMP(ptr, "if", 2) == 0 || STRNCMP(ptr, "el", 2) == 0) {
           hash_dir = 1;
         } else if (STRNCMP(ptr, "endif", 5) == 0) {
@@ -1853,14 +1853,14 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
           break;
         }
         pos.lnum += hash_dir;
-        linep = (char_u *)ml_get(pos.lnum);
+        linep = ml_get(pos.lnum);
         line_breakcheck();              // check for CTRL-C typed
-        ptr = (char_u *)skipwhite((char *)linep);
+        ptr = skipwhite(linep);
         if (*ptr != '#') {
           continue;
         }
         pos.col = (colnr_T)(ptr - linep);
-        ptr = (char_u *)skipwhite((char *)ptr + 1);
+        ptr = skipwhite(ptr + 1);
         if (hash_dir > 0) {
           if (STRNCMP(ptr, "if", 2) == 0) {
             count++;
@@ -1907,7 +1907,7 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
 
   // backward search: Check if this line contains a single-line comment
   if ((backwards && comment_dir) || lisp) {
-    comment_col = check_linecomment((char *)linep);
+    comment_col = check_linecomment(linep);
   }
   if (lisp && comment_col != MAXCOL && pos.col > (colnr_T)comment_col) {
     lispcomm = true;        // find match inside this comment
@@ -1931,14 +1931,14 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
           break;
         }
 
-        linep = (char_u *)ml_get(pos.lnum);
-        pos.col = (colnr_T)STRLEN(linep);         // pos.col on trailing NUL
+        linep = ml_get(pos.lnum);
+        pos.col = (colnr_T)strlen(linep);         // pos.col on trailing NUL
         do_quotes = -1;
         line_breakcheck();
 
         // Check if this line contains a single-line comment
         if (comment_dir || lisp) {
-          comment_col = check_linecomment((char *)linep);
+          comment_col = check_linecomment(linep);
         }
         // skip comment
         if (lisp && comment_col != MAXCOL) {
@@ -1946,7 +1946,7 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
         }
       } else {
         pos.col--;
-        pos.col -= utf_head_off((char *)linep, (char *)linep + pos.col);
+        pos.col -= utf_head_off(linep, linep + pos.col);
       }
     } else {                          // forward search
       if (linep[pos.col] == NUL
@@ -1966,15 +1966,15 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
           break;
         }
 
-        linep = (char_u *)ml_get(pos.lnum);
+        linep = ml_get(pos.lnum);
         pos.col = 0;
         do_quotes = -1;
         line_breakcheck();
         if (lisp) {         // find comment pos in new line
-          comment_col = check_linecomment((char *)linep);
+          comment_col = check_linecomment(linep);
         }
       } else {
-        pos.col += utfc_ptr2len((char *)linep + pos.col);
+        pos.col += utfc_ptr2len(linep + pos.col);
       }
     }
 
@@ -2003,18 +2003,18 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
         } else if (raw_string) {
           if (linep[pos.col - 1] == 'R'
               && linep[pos.col] == '"'
-              && vim_strchr((char *)linep + pos.col + 1, '(') != NULL) {
+              && vim_strchr(linep + pos.col + 1, '(') != NULL) {
             // Possible start of raw string. Now that we have the
             // delimiter we can check if it ends before where we
             // started searching, or before the previously found
             // raw string start.
-            if (!find_rawstring_end((char *)linep, &pos,
+            if (!find_rawstring_end(linep, &pos,
                                     count > 0 ? &match_pos : &curwin->w_cursor)) {
               count++;
               match_pos = pos;
               match_pos.col--;
             }
-            linep = (char_u *)ml_get(pos.lnum);  // may have been released
+            linep = ml_get(pos.lnum);  // may have been released
           }
         } else if (linep[pos.col - 1] == '/'
                    && linep[pos.col] == '*'
@@ -2078,8 +2078,8 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
           }
         }
         if (pos.lnum > 1) {
-          ptr = (char_u *)ml_get(pos.lnum - 1);
-          if (*ptr && *(ptr + STRLEN(ptr) - 1) == '\\') {
+          ptr = ml_get(pos.lnum - 1);
+          if (*ptr && *(ptr + strlen(ptr) - 1) == '\\') {
             do_quotes = 1;
             if (start_in_quotes == kNone) {
               inquote = at_start;
@@ -2092,7 +2092,7 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
           }
 
           // ml_get() only keeps one line, need to get linep again
-          linep = (char_u *)ml_get(pos.lnum);
+          linep = ml_get(pos.lnum);
         }
       }
     }
@@ -2109,7 +2109,7 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
     //   we do not know which part to ignore. Therefore we only set
     //   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((char *)linep + pos.col);
+    const int c = utf_ptr2char(linep + pos.col);
     switch (c) {
     case NUL:
       // at end of line without trailing backslash, reset inquote
@@ -2174,8 +2174,8 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
       if (curbuf->b_p_lisp
           && vim_strchr("(){}[]", c) != NULL
           && pos.col > 1
-          && check_prevcol(linep, pos.col, '\\', NULL)
-          && check_prevcol(linep, pos.col - 1, '#', NULL)) {
+          && check_prevcol((char_u *)linep, pos.col, '\\', NULL)
+          && check_prevcol((char_u *)linep, pos.col - 1, '#', NULL)) {
         break;
       }
 
@@ -2186,7 +2186,7 @@ pos_T *findmatchlimit(oparg_T *oap, int initc, int flags, int64_t maxtravel)
         int col, bslcnt = 0;
 
         if (!cpo_bsl) {
-          for (col = pos.col; check_prevcol(linep, col, '\\', &col);) {
+          for (col = pos.col; check_prevcol((char_u *)linep, col, '\\', &col);) {
             bslcnt++;
           }
         }
@@ -2389,7 +2389,7 @@ int current_search(long count, bool forward)
   }
 
   // Is the pattern is zero-width?, this time, don't care about the direction
-  int zero_width = is_zero_width(spats[last_idx].pat, true, &curwin->w_cursor,
+  int zero_width = is_zero_width((char_u *)spats[last_idx].pat, true, &curwin->w_cursor,
                                  FORWARD);
   if (zero_width == -1) {
     return FAIL;  // pattern not found
@@ -2423,7 +2423,7 @@ int current_search(long count, bool forward)
 
     result = searchit(curwin, curbuf, &pos, &end_pos,
                       (dir ? FORWARD : BACKWARD),
-                      spats[last_idx].pat, i ? count : 1,
+                      (char_u *)spats[last_idx].pat, i ? count : 1,
                       SEARCH_KEEP | flags, RE_SEARCH, NULL);
 
     p_ws = old_p_ws;
@@ -2507,7 +2507,7 @@ static int is_zero_width(char_u *pattern, int move, pos_T *cur, Direction direct
   int flag = 0;
 
   if (pattern == NULL) {
-    pattern = spats[last_idx].pat;
+    pattern = (char_u *)spats[last_idx].pat;
   }
 
   if (search_regcomp(pattern, RE_SEARCH, RE_SEARCH,
@@ -2562,10 +2562,10 @@ int linewhite(linenr_T lnum)
   return *p == NUL;
 }
 
-// Add the search count "[3/19]" to "msgbuf".
-// See update_search_stat() for other arguments.
+/// Add the search count "[3/19]" to "msgbuf".
+/// See update_search_stat() for other arguments.
 static void cmdline_search_stat(int dirc, pos_T *pos, pos_T *cursor_pos, bool show_top_bot_msg,
-                                char_u *msgbuf, bool recompute, int maxcount, long timeout)
+                                char *msgbuf, bool recompute, int maxcount, long timeout)
 {
   searchstat_T stat;
 
@@ -2610,7 +2610,7 @@ static void cmdline_search_stat(int dirc, pos_T *pos, pos_T *cursor_pos, bool sh
       len += 2;
     }
 
-    memmove(msgbuf + STRLEN(msgbuf) - len, t, len);
+    memmove(msgbuf + strlen(msgbuf) - len, t, len);
     if (dirc == '?' && stat.cur == maxcount + 1) {
       stat.cur = -1;
     }
@@ -2618,7 +2618,7 @@ static void cmdline_search_stat(int dirc, pos_T *pos, pos_T *cursor_pos, bool sh
     // keep the message even after redraw, but don't put in history
     msg_hist_off = true;
     msg_ext_set_kind("search_count");
-    give_warning((char *)msgbuf, false);
+    give_warning(msgbuf, false);
     msg_hist_off = false;
   }
 }
@@ -2642,7 +2642,7 @@ static void update_search_stat(int dirc, pos_T *pos, pos_T *cursor_pos, searchst
   static int incomplete = 0;
   static int last_maxcount = SEARCH_STAT_DEF_MAX_COUNT;
   static int chgtick = 0;
-  static char_u *lastpat = NULL;
+  static char *lastpat = NULL;
   static buf_T *lbuf = NULL;
   proftime_T start;
 
@@ -2666,8 +2666,8 @@ static void update_search_stat(int dirc, pos_T *pos, pos_T *cursor_pos, searchst
   // XXX: above comment should be "no MB_STRCMP function" ?
   if (!(chgtick == buf_get_changedtick(curbuf)
         && lastpat != NULL  // suppress clang/NULL passed as nonnull parameter
-        && STRNICMP(lastpat, spats[last_idx].pat, STRLEN(lastpat)) == 0
-        && STRLEN(lastpat) == STRLEN(spats[last_idx].pat)
+        && STRNICMP(lastpat, spats[last_idx].pat, strlen(lastpat)) == 0
+        && strlen(lastpat) == strlen(spats[last_idx].pat)
         && equalpos(lastpos, *cursor_pos)
         && lbuf == curbuf)
       || wraparound || cur < 0 || (maxcount > 0 && cur > maxcount)
@@ -2717,7 +2717,7 @@ static void update_search_stat(int dirc, pos_T *pos, pos_T *cursor_pos, searchst
     }
     if (done_search) {
       xfree(lastpat);
-      lastpat = (char_u *)xstrdup((char *)spats[last_idx].pat);
+      lastpat = xstrdup(spats[last_idx].pat);
       chgtick = (int)buf_get_changedtick(curbuf);
       lbuf = curbuf;
       lastpos = p;
@@ -2827,7 +2827,7 @@ void f_searchcount(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
       goto the_end;
     }
     xfree(spats[last_idx].pat);
-    spats[last_idx].pat = (char_u *)xstrdup((char *)pattern);
+    spats[last_idx].pat = xstrdup((char *)pattern);
   }
   if (spats[last_idx].pat == NULL || *spats[last_idx].pat == NUL) {
     goto the_end;  // the previous pattern was never defined
@@ -3433,9 +3433,9 @@ void find_pattern_in_path(char_u *ptr, Direction dir, size_t len, bool whole, bo
   int old_files;
   int already_searched;
   char_u *file_line;
-  char_u *line;
-  char_u *p;
-  char_u save_char;
+  char *line;
+  char *p;
+  char save_char;
   bool define_matched;
   regmatch_T regmatch;
   regmatch_T incl_regmatch;
@@ -3444,8 +3444,8 @@ void find_pattern_in_path(char_u *ptr, Direction dir, size_t len, bool whole, bo
   bool did_show = false;
   bool found = false;
   int i;
-  char_u *already = NULL;
-  char_u *startp = NULL;
+  char *already = NULL;
+  char *startp = NULL;
   win_T *curwin_save = NULL;
   const int l_g_do_tagpreview = g_do_tagpreview;
 
@@ -3499,11 +3499,11 @@ void find_pattern_in_path(char_u *ptr, Direction dir, size_t len, bool whole, bo
   if (lnum > end_lnum) {                // do at least one line
     lnum = end_lnum;
   }
-  line = get_line_and_copy(lnum, file_line);
+  line = (char *)get_line_and_copy(lnum, file_line);
 
   for (;;) {
     if (incl_regmatch.regprog != NULL
-        && vim_regexec(&incl_regmatch, (char *)line, (colnr_T)0)) {
+        && vim_regexec(&incl_regmatch, line, (colnr_T)0)) {
       char_u *p_fname = (curr_fname == (char_u *)curbuf->b_fname)
                         ? (char_u *)curbuf->b_ffname : curr_fname;
 
@@ -3584,20 +3584,20 @@ void find_pattern_in_path(char_u *ptr, Direction dir, size_t len, bool whole, bo
             if (inc_opt != NULL
                 && strstr(inc_opt, "\\zs") != NULL) {
               // pattern contains \zs, use the match
-              p = (char_u *)incl_regmatch.startp[0];
+              p = incl_regmatch.startp[0];
               i = (int)(incl_regmatch.endp[0]
                         - incl_regmatch.startp[0]);
             } else {
               // find the file name after the end of the match
-              for (p = (char_u *)incl_regmatch.endp[0];
-                   *p && !vim_isfilec(*p); p++) {}
-              for (i = 0; vim_isfilec(p[i]); i++) {}
+              for (p = incl_regmatch.endp[0];
+                   *p && !vim_isfilec((uint8_t)(*p)); p++) {}
+              for (i = 0; vim_isfilec((uint8_t)p[i]); i++) {}
             }
 
             if (i == 0) {
               // Nothing found, use the rest of the line.
-              p = (char_u *)incl_regmatch.endp[0];
-              i = (int)STRLEN(p);
+              p = incl_regmatch.endp[0];
+              i = (int)strlen(p);
             } else if (p > line) {
               // Avoid checking before the start of the line, can
               // happen if \zs appears in the regexp.
@@ -3611,7 +3611,7 @@ void find_pattern_in_path(char_u *ptr, Direction dir, size_t len, bool whole, bo
             }
             save_char = p[i];
             p[i] = NUL;
-            msg_outtrans_attr((char *)p, HL_ATTR(HLF_D));
+            msg_outtrans_attr(p, HL_ATTR(HLF_D));
             p[i] = save_char;
           }
 
@@ -3678,12 +3678,12 @@ void find_pattern_in_path(char_u *ptr, Direction dir, size_t len, bool whole, bo
 search_line:
       define_matched = false;
       if (def_regmatch.regprog != NULL
-          && vim_regexec(&def_regmatch, (char *)line, (colnr_T)0)) {
+          && vim_regexec(&def_regmatch, line, (colnr_T)0)) {
         // Pattern must be first identifier after 'define', so skip
         // to that position before checking for match of pattern.  Also
         // don't let it match beyond the end of this identifier.
-        p = (char_u *)def_regmatch.endp[0];
-        while (*p && !vim_iswordc(*p)) {
+        p = def_regmatch.endp[0];
+        while (*p && !vim_iswordc((uint8_t)(*p))) {
           p++;
         }
         define_matched = true;
@@ -3694,27 +3694,27 @@ search_line:
       if (def_regmatch.regprog == NULL || define_matched) {
         if (define_matched || compl_status_sol()) {
           // compare the first "len" chars from "ptr"
-          startp = (char_u *)skipwhite((char *)p);
+          startp = skipwhite(p);
           if (p_ic) {
-            matched = !mb_strnicmp((char *)startp, (char *)ptr, len);
+            matched = !mb_strnicmp(startp, (char *)ptr, len);
           } else {
             matched = !STRNCMP(startp, ptr, len);
           }
           if (matched && define_matched && whole
-              && vim_iswordc(startp[len])) {
+              && vim_iswordc((uint8_t)startp[len])) {
             matched = false;
           }
         } else if (regmatch.regprog != NULL
-                   && vim_regexec(&regmatch, (char *)line, (colnr_T)(p - line))) {
+                   && vim_regexec(&regmatch, line, (colnr_T)(p - line))) {
           matched = true;
-          startp = (char_u *)regmatch.startp[0];
+          startp = regmatch.startp[0];
           // Check if the line is not a comment line (unless we are
           // looking for a define).  A line starting with "# define"
           // is not considered to be a comment line.
           if (skip_comments) {
             if ((*line != '#'
                  || STRNCMP(skipwhite((char *)line + 1), "define", 6) != 0)
-                && get_leader_len((char *)line, NULL, false, true)) {
+                && get_leader_len(line, NULL, false, true)) {
               matched = false;
             }
 
@@ -3722,7 +3722,7 @@ search_line:
             // Skips lines like "int backwards;  / * normal index
             // * /" when looking for "normal".
             // Note: Doesn't skip "/ *" in comments.
-            p = (char_u *)skipwhite((char *)line);
+            p = skipwhite(line);
             if (matched
                 || (p[0] == '/' && p[1] == '*') || p[0] == '*') {
               for (p = line; *p && p < startp; p++) {
@@ -3754,15 +3754,15 @@ search_line:
           break;
         }
         found = true;
-        char_u *aux = p = startp;
+        char *aux = p = startp;
         if (compl_status_adding()) {
           p += ins_compl_len();
-          if (vim_iswordp(p)) {
+          if (vim_iswordp((char_u *)p)) {
             goto exit_matched;
           }
-          p = find_word_start(p);
+          p = (char *)find_word_start((char_u *)p);
         }
-        p = find_word_end(p);
+        p = (char *)find_word_end((char_u *)p);
         i = (int)(p - aux);
 
         if (compl_status_adding() && i == ins_compl_len()) {
@@ -3776,8 +3776,8 @@ search_line:
             if (lnum >= end_lnum) {
               goto exit_matched;
             }
-            line = get_line_and_copy(++lnum, file_line);
-          } else if (vim_fgets(line = file_line,
+            line = (char *)get_line_and_copy(++lnum, file_line);
+          } else if (vim_fgets(line = (char *)file_line,
                                LSIZE, files[depth].fp)) {
             goto exit_matched;
           }
@@ -3785,9 +3785,9 @@ search_line:
           // we read a line, set "already" to check this "line" later
           // if depth >= 0 we'll increase files[depth].lnum far
           // below  -- Acevedo
-          already = aux = p = (char_u *)skipwhite((char *)line);
-          p = find_word_start(p);
-          p = find_word_end(p);
+          already = aux = p = skipwhite(line);
+          p = (char *)find_word_start((char_u *)p);
+          p = (char *)find_word_end((char_u *)p);
           if (p > aux) {
             if (*aux != ')' && IObuff[i - 1] != TAB) {
               if (IObuff[i - 1] != ' ') {
@@ -3810,14 +3810,14 @@ search_line:
             cont_s_ipos = true;
           }
           IObuff[i] = NUL;
-          aux = (char_u *)IObuff;
+          aux = IObuff;
 
           if (i == ins_compl_len()) {
             goto exit_matched;
           }
         }
 
-        const int add_r = ins_compl_add_infercase(aux, i, p_ic,
+        const int add_r = ins_compl_add_infercase((char_u *)aux, i, p_ic,
                                                   curr_fname == (char_u *)curbuf->b_fname
                                                   ? NULL : curr_fname,
                                                   dir, cont_s_ipos);
@@ -3924,7 +3924,7 @@ exit_matched:
           && action == ACTION_EXPAND
           && !compl_status_sol()
           && *startp != NUL
-          && *(p = startp + utfc_ptr2len((char *)startp)) != NUL) {
+          && *(p = startp + utfc_ptr2len(startp)) != NUL) {
         goto search_line;
       }
     }
@@ -3940,7 +3940,7 @@ exit_matched:
     // end-of-file, close the file and continue in the file that included
     // it.
     while (depth >= 0 && !already
-           && vim_fgets(line = file_line, LSIZE, files[depth].fp)) {
+           && vim_fgets(line = (char *)file_line, LSIZE, files[depth].fp)) {
       fclose(files[depth].fp);
       old_files--;
       files[old_files].name = files[depth].name;
@@ -3955,7 +3955,7 @@ exit_matched:
     if (depth >= 0) {           // we could read the line
       files[depth].lnum++;
       // Remove any CR and LF from the line.
-      i = (int)STRLEN(line);
+      i = (int)strlen(line);
       if (i > 0 && line[i - 1] == '\n') {
         line[--i] = NUL;
       }
@@ -3966,7 +3966,7 @@ exit_matched:
       if (++lnum > end_lnum) {
         break;
       }
-      line = get_line_and_copy(lnum, file_line);
+      line = (char *)get_line_and_copy(lnum, file_line);
     }
     already = NULL;
   }
@@ -4011,11 +4011,11 @@ fpip_end:
   vim_regfree(def_regmatch.regprog);
 }
 
-static void show_pat_in_path(char_u *line, int type, bool did_show, int action, FILE *fp,
+static void show_pat_in_path(char *line, int type, bool did_show, int action, FILE *fp,
                              linenr_T *lnum, long count)
   FUNC_ATTR_NONNULL_ARG(1, 6)
 {
-  char_u *p;
+  char *p;
 
   if (did_show) {
     msg_putchar('\n');          // cursor below last one
@@ -4026,7 +4026,7 @@ static void show_pat_in_path(char_u *line, int type, bool did_show, int action,
     return;
   }
   for (;;) {
-    p = line + STRLEN(line) - 1;
+    p = line + strlen(line) - 1;
     if (fp != NULL) {
       // We used fgets(), so get rid of newline at end
       if (p >= line && *p == '\n') {
@@ -4045,7 +4045,7 @@ static void show_pat_in_path(char_u *line, int type, bool did_show, int action,
       msg_puts_attr((const char *)IObuff, HL_ATTR(HLF_N));
       msg_puts(" ");
     }
-    msg_prt_line((char *)line, false);
+    msg_prt_line(line, false);
 
     // Definition continues until line that doesn't end with '\'
     if (got_int || type != FIND_DEFINE || p < line || *p != '\\') {
@@ -4061,7 +4061,7 @@ static void show_pat_in_path(char_u *line, int type, bool did_show, int action,
       if (++*lnum > curbuf->b_ml.ml_line_count) {
         break;
       }
-      line = (char_u *)ml_get(*lnum);
+      line = ml_get(*lnum);
     }
     msg_putchar('\n');
   }
diff --git a/src/nvim/search.h b/src/nvim/search.h
index cd8431c916..092098d5fd 100644
--- a/src/nvim/search.h
+++ b/src/nvim/search.h
@@ -73,7 +73,7 @@ typedef struct soffset {
 
 /// Structure containing last search pattern and its attributes.
 typedef struct spat {
-  char_u *pat;          ///< The pattern (in allocated memory) or NULL.
+  char *pat;            ///< The pattern (in allocated memory) or NULL.
   bool magic;           ///< Magicness of the pattern.
   bool no_scs;          ///< No smartcase for this pattern.
   Timestamp timestamp;  ///< Time of the last change.
diff --git a/src/nvim/shada.c b/src/nvim/shada.c
index 42f5e3456d..0f81217b4a 100644
--- a/src/nvim/shada.c
+++ b/src/nvim/shada.c
@@ -1217,7 +1217,7 @@ static void shada_read(ShaDaReadDef *const sd_reader, const int flags)
           .end = cur_entry.data.search_pattern.place_cursor_at_end,
           .off = cur_entry.data.search_pattern.offset,
         },
-        .pat = (char_u *)cur_entry.data.search_pattern.pat,
+        .pat = cur_entry.data.search_pattern.pat,
         .additional_data = cur_entry.data.search_pattern.additional_data,
         .timestamp = cur_entry.timestamp,
       };
@@ -2379,7 +2379,7 @@ static inline void add_search_pattern(PossiblyFreedShadaEntry *const ret_pse,
             .is_substitute_pattern = is_substitute_pattern,
             .highlighted = ((is_substitute_pattern ^ search_last_used)
                             && search_highlighted),
-            .pat = (char *)pat.pat,
+            .pat = pat.pat,
             .additional_data = pat.additional_data,
             .search_backward = (!is_substitute_pattern && pat.off.dir == '?'),
           }
diff --git a/src/nvim/spell.c b/src/nvim/spell.c
index 8ee28fea34..e6d2eac7c3 100644
--- a/src/nvim/spell.c
+++ b/src/nvim/spell.c
@@ -2590,7 +2590,7 @@ void ex_spellrepall(exarg_T *eap)
   sub_nlines = 0;
   curwin->w_cursor.lnum = 0;
   while (!got_int) {
-    if (do_search(NULL, '/', '/', frompat, 1L, SEARCH_KEEP, NULL) == 0
+    if (do_search(NULL, '/', '/', (char *)frompat, 1L, SEARCH_KEEP, NULL) == 0
         || u_save_cursor() == FAIL) {
       break;
     }
diff --git a/src/nvim/spellfile.c b/src/nvim/spellfile.c
index 395051453a..1b338ef4bf 100644
--- a/src/nvim/spellfile.c
+++ b/src/nvim/spellfile.c
@@ -2086,7 +2086,7 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
   hash_init(&aff->af_comp);
 
   // Read all the lines in the file one by one.
-  while (!vim_fgets(rline, MAXLINELEN, fd) && !got_int) {
+  while (!vim_fgets((char *)rline, MAXLINELEN, fd) && !got_int) {
     line_breakcheck();
     lnum++;
 
@@ -3146,14 +3146,14 @@ static int spell_read_dic(spellinfo_T *spin, char_u *fname, afffile_T *affile)
   spin->si_msg_count = 999999;
 
   // Read and ignore the first line: word count.
-  if (vim_fgets(line, MAXLINELEN, fd) || !ascii_isdigit(*skipwhite((char *)line))) {
+  if (vim_fgets((char *)line, MAXLINELEN, fd) || !ascii_isdigit(*skipwhite((char *)line))) {
     semsg(_("E760: No word count in %s"), fname);
   }
 
   // Read all the lines in the file one by one.
   // The words are converted to 'encoding' here, before being added to
   // the hashtable.
-  while (!vim_fgets(line, MAXLINELEN, fd) && !got_int) {
+  while (!vim_fgets((char *)line, MAXLINELEN, fd) && !got_int) {
     line_breakcheck();
     lnum++;
     if (line[0] == '#' || line[0] == '/') {
@@ -3696,7 +3696,7 @@ static int spell_read_wordfile(spellinfo_T *spin, char_u *fname)
   spell_message(spin, (char *)IObuff);
 
   // Read all the lines in the file one by one.
-  while (!vim_fgets(rline, MAXLINELEN, fd) && !got_int) {
+  while (!vim_fgets((char *)rline, MAXLINELEN, fd) && !got_int) {
     line_breakcheck();
     lnum++;
 
@@ -5598,7 +5598,7 @@ void spell_add_word(char_u *word, int len, SpellAddType what, int idx, bool undo
     // since its flags sort before the one with WF_BANNED.
     fd = os_fopen(fname, "r");
     if (fd != NULL) {
-      while (!vim_fgets(line, MAXWLEN * 2, fd)) {
+      while (!vim_fgets((char *)line, MAXWLEN * 2, fd)) {
         fpos = fpos_next;
         fpos_next = ftell(fd);
         if (fpos_next < 0) {
diff --git a/src/nvim/spellsuggest.c b/src/nvim/spellsuggest.c
index 355233fc5b..cc5c61b855 100644
--- a/src/nvim/spellsuggest.c
+++ b/src/nvim/spellsuggest.c
@@ -641,7 +641,7 @@ void spell_suggest(int count)
     }
 
     // Replace the word.
-    p = xmalloc(STRLEN(line) - (size_t)stp->st_orglen + (size_t)stp->st_wordlen + 1);
+    p = xmalloc(strlen(line) - (size_t)stp->st_orglen + (size_t)stp->st_wordlen + 1);
     c = (int)(sug.su_badptr - (char_u *)line);
     memmove(p, line, (size_t)c);
     STRCPY(p + c, stp->st_word);
@@ -880,7 +880,7 @@ static void spell_suggest_file(suginfo_T *su, char_u *fname)
   }
 
   // Read it line by line.
-  while (!vim_fgets(line, MAXWLEN * 2, fd) && !got_int) {
+  while (!vim_fgets((char *)line, MAXWLEN * 2, fd) && !got_int) {
     line_breakcheck();
 
     p = (char_u *)vim_strchr((char *)line, '/');
diff --git a/src/nvim/tag.c b/src/nvim/tag.c
index 45fe59012e..8be343b055 100644
--- a/src/nvim/tag.c
+++ b/src/nvim/tag.c
@@ -1507,7 +1507,7 @@ static bool findtags_in_help_init(findtags_state_T *st)
   } else {
     st->help_pri = 1;
     char *s;
-    for (s = (char *)p_hlg; *s != NUL; s++) {
+    for (s = p_hlg; *s != NUL; s++) {
       if (STRNICMP(s, st->help_lang, 2) == 0) {
         break;
       }
@@ -1584,7 +1584,7 @@ static tags_read_status_T findtags_get_next_line(findtags_state_T *st, tagsearch
     // Adjust the search file offset to the correct position
     sinfo_p->curr_offset_used = sinfo_p->curr_offset;
     vim_ignored = vim_fseek(st->fp, sinfo_p->curr_offset, SEEK_SET);
-    eof = vim_fgets((char_u *)st->lbuf, st->lbuf_size, st->fp);
+    eof = vim_fgets(st->lbuf, st->lbuf_size, st->fp);
     if (!eof && sinfo_p->curr_offset != 0) {
       sinfo_p->curr_offset = vim_ftell(st->fp);
       if (sinfo_p->curr_offset == sinfo_p->high_offset) {
@@ -1592,12 +1592,12 @@ static tags_read_status_T findtags_get_next_line(findtags_state_T *st, tagsearch
         vim_ignored = vim_fseek(st->fp, sinfo_p->low_offset, SEEK_SET);
         sinfo_p->curr_offset = sinfo_p->low_offset;
       }
-      eof = vim_fgets((char_u *)st->lbuf, st->lbuf_size, st->fp);
+      eof = vim_fgets(st->lbuf, st->lbuf_size, st->fp);
     }
     // skip empty and blank lines
     while (!eof && vim_isblankline(st->lbuf)) {
       sinfo_p->curr_offset = vim_ftell(st->fp);
-      eof = vim_fgets((char_u *)st->lbuf, st->lbuf_size, st->fp);
+      eof = vim_fgets(st->lbuf, st->lbuf_size, st->fp);
     }
     if (eof) {
       // Hit end of file.  Skip backwards.
@@ -1611,7 +1611,7 @@ static tags_read_status_T findtags_get_next_line(findtags_state_T *st, tagsearch
 
     // skip empty and blank lines
     do {
-      eof = vim_fgets((char_u *)st->lbuf, st->lbuf_size, st->fp);
+      eof = vim_fgets(st->lbuf, st->lbuf_size, st->fp);
     } while (!eof && vim_isblankline(st->lbuf));
 
     if (eof) {
@@ -2997,7 +2997,7 @@ static int jumpto_tag(const char_u *lbuf_arg, int forceit, int keep_help)
         // start search before first line
         curwin->w_cursor.lnum = 0;
       }
-      if (do_search(NULL, pbuf[0], pbuf[0], pbuf + 1, (long)1,
+      if (do_search(NULL, pbuf[0], pbuf[0], (char *)pbuf + 1, (long)1,
                     search_options, NULL)) {
         retval = OK;
       } else {
@@ -3006,7 +3006,7 @@ static int jumpto_tag(const char_u *lbuf_arg, int forceit, int keep_help)
 
         // try again, ignore case now
         p_ic = true;
-        if (!do_search(NULL, pbuf[0], pbuf[0], pbuf + 1, (long)1,
+        if (!do_search(NULL, pbuf[0], pbuf[0], (char *)pbuf + 1, (long)1,
                        search_options, NULL)) {
           // Failed to find pattern, take a guess: "^func  ("
           found = 2;
@@ -3014,11 +3014,11 @@ static int jumpto_tag(const char_u *lbuf_arg, int forceit, int keep_help)
           cc = *tagp.tagname_end;
           *tagp.tagname_end = NUL;
           snprintf((char *)pbuf, LSIZE, "^%s\\s\\*(", tagp.tagname);
-          if (!do_search(NULL, '/', '/', pbuf, (long)1, search_options, NULL)) {
+          if (!do_search(NULL, '/', '/', (char *)pbuf, (long)1, search_options, NULL)) {
             // Guess again: "^char * \<func  ("
             snprintf((char *)pbuf, LSIZE, "^\\[#a-zA-Z_]\\.\\*\\<%s\\s\\*(",
                      tagp.tagname);
-            if (!do_search(NULL, '/', '/', pbuf, (long)1,
+            if (!do_search(NULL, '/', '/', (char *)pbuf, (long)1,
                            search_options, NULL)) {
               found = 0;
             }