refactor: replace char_u with char

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

43 files changed, 499 insertions, 537 deletions

diff --git a/src/nvim/cmdhist.c b/src/nvim/cmdhist.c
index cd494d2247..5725a6655d 100644
--- a/src/nvim/cmdhist.c
+++ b/src/nvim/cmdhist.c
@@ -583,7 +583,7 @@ void ex_history(exarg_T *eap)
   int hisidx2 = -1;
   int idx;
   int i, j, k;
-  char_u *end;
+  char *end;
   char_u *arg = (char_u *)eap->arg;
 
   if (hislen == 0) {
@@ -592,14 +592,14 @@ void ex_history(exarg_T *eap)
   }
 
   if (!(ascii_isdigit(*arg) || *arg == '-' || *arg == ',')) {
-    end = arg;
+    end = (char *)arg;
     while (ASCII_ISALPHA(*end)
            || vim_strchr(":=@>/?", *end) != NULL) {
       end++;
     }
-    histype1 = get_histtype((const char *)arg, (size_t)(end - arg), false);
+    histype1 = get_histtype((const char *)arg, (size_t)(end - (char *)arg), false);
     if (histype1 == HIST_INVALID) {
-      if (STRNICMP(arg, "all", end - arg) == 0) {
+      if (STRNICMP(arg, "all", end - (char *)arg) == 0) {
         histype1 = 0;
         histype2 = HIST_COUNT - 1;
       } else {
@@ -610,7 +610,7 @@ void ex_history(exarg_T *eap)
       histype2 = histype1;
     }
   } else {
-    end = arg;
+    end = (char *)arg;
   }
   if (!get_list_range(&end, &hisidx1, &hisidx2) || *end != NUL) {
     semsg(_(e_trailing_arg), end);
diff --git a/src/nvim/diff.c b/src/nvim/diff.c
index e3a6f9039d..ec580856f9 100644
--- a/src/nvim/diff.c
+++ b/src/nvim/diff.c
@@ -2143,14 +2143,14 @@ int diffopt_changed(void)
   long diff_algorithm_new = 0;
   long diff_indent_heuristic = 0;
 
-  char_u *p = p_dip;
+  char *p = (char *)p_dip;
   while (*p != NUL) {
     if (STRNCMP(p, "filler", 6) == 0) {
       p += 6;
       diff_flags_new |= DIFF_FILLER;
     } else if ((STRNCMP(p, "context:", 8) == 0) && ascii_isdigit(p[8])) {
       p += 8;
-      diff_context_new = getdigits_int((char **)&p, false, diff_context_new);
+      diff_context_new = getdigits_int(&p, false, diff_context_new);
     } else if (STRNCMP(p, "iblank", 6) == 0) {
       p += 6;
       diff_flags_new |= DIFF_IBLANK;
@@ -2174,7 +2174,7 @@ int diffopt_changed(void)
       diff_flags_new |= DIFF_VERTICAL;
     } else if ((STRNCMP(p, "foldcolumn:", 11) == 0) && ascii_isdigit(p[11])) {
       p += 11;
-      diff_foldcolumn_new = getdigits_int((char **)&p, false, diff_foldcolumn_new);
+      diff_foldcolumn_new = getdigits_int(&p, false, diff_foldcolumn_new);
     } else if (STRNCMP(p, "hiddenoff", 9) == 0) {
       p += 9;
       diff_flags_new |= DIFF_HIDDEN_OFF;
diff --git a/src/nvim/edit.c b/src/nvim/edit.c
index 5861e4c52b..7ddff92632 100644
--- a/src/nvim/edit.c
+++ b/src/nvim/edit.c
@@ -2022,7 +2022,7 @@ static void insert_special(int c, int allow_modmask, int ctrlv)
 /// @param second_indent  indent for second line if >= 0
 void insertchar(int c, int flags, int second_indent)
 {
-  char_u *p;
+  char *p;
   int force_format = flags & INSCHAR_FORMAT;
 
   const int textwidth = comp_textwidth(force_format);
@@ -2081,13 +2081,13 @@ void insertchar(int c, int flags, int second_indent)
     // Need to remove existing (middle) comment leader and insert end
     // comment leader.  First, check what comment leader we can find.
     char_u *line = get_cursor_line_ptr();
-    int i = get_leader_len((char *)line, (char **)&p, false, true);
-    if (i > 0 && vim_strchr((char *)p, COM_MIDDLE) != NULL) {  // Just checking
+    int i = get_leader_len((char *)line, &p, false, true);
+    if (i > 0 && vim_strchr(p, COM_MIDDLE) != NULL) {  // Just checking
       // Skip middle-comment string
       while (*p && p[-1] != ':') {  // find end of middle flags
         p++;
       }
-      int middle_len = (int)copy_option_part((char **)&p, (char *)lead_end, COM_MAX_LEN, ",");
+      int middle_len = (int)copy_option_part(&p, (char *)lead_end, COM_MAX_LEN, ",");
       // Don't count trailing white space for middle_len
       while (middle_len > 0 && ascii_iswhite(lead_end[middle_len - 1])) {
         middle_len--;
@@ -2097,7 +2097,7 @@ void insertchar(int c, int flags, int second_indent)
       while (*p && p[-1] != ':') {  // find end of end flags
         p++;
       }
-      int end_len = (int)copy_option_part((char **)&p, (char *)lead_end, COM_MAX_LEN, ",");
+      int end_len = (int)copy_option_part(&p, (char *)lead_end, COM_MAX_LEN, ",");
 
       // Skip white space before the cursor
       i = curwin->w_cursor.col;
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index c08b3e41d4..64a4a92ab7 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -2258,7 +2258,7 @@ static int eval_func(char **const arg, char *const name, const int name_len, typ
   funcexe.evaluate = evaluate;
   funcexe.partial = partial;
   funcexe.basetv = basetv;
-  int ret = get_func_tv((char_u *)s, len, rettv, (char_u **)arg, &funcexe);
+  int ret = get_func_tv((char_u *)s, len, rettv, arg, &funcexe);
 
   xfree(s);
 
@@ -3114,7 +3114,7 @@ static int eval7(char **arg, typval_T *rettv, int evaluate, int want_string)
   // Lambda: {arg, arg -> expr}
   // Dictionary: {'key': val, 'key': val}
   case '{':
-    ret = get_lambda_tv((char_u **)arg, rettv, evaluate);
+    ret = get_lambda_tv(arg, rettv, evaluate);
     if (ret == NOTDONE) {
       ret = dict_get_tv(arg, rettv, evaluate, false);
     }
@@ -3292,7 +3292,7 @@ static int call_func_rettv(char **const arg, typval_T *const rettv, const bool e
   funcexe.selfdict = selfdict;
   funcexe.basetv = basetv;
   const int ret = get_func_tv((char_u *)funcname, is_lua ? (int)(*arg - funcname) : -1, rettv,
-                              (char_u **)arg, &funcexe);
+                              arg, &funcexe);
 
   // Clear the funcref afterwards, so that deleting it while
   // evaluating the arguments is possible (see test55).
@@ -3320,7 +3320,7 @@ static int eval_lambda(char **const arg, typval_T *const rettv, const bool evalu
   typval_T base = *rettv;
   rettv->v_type = VAR_UNKNOWN;
 
-  int ret = get_lambda_tv((char_u **)arg, rettv, evaluate);
+  int ret = get_lambda_tv(arg, rettv, evaluate);
   if (ret != OK) {
     return FAIL;
   } else if (**arg != '(') {
@@ -3924,11 +3924,11 @@ static int get_string_tv(char **arg, typval_T *rettv, int evaluate)
         FALLTHROUGH;
 
       default:
-        mb_copy_char((const char_u **)&p, (char_u **)&name);
+        mb_copy_char((const char **)&p, &name);
         break;
       }
     } else {
-      mb_copy_char((const char_u **)&p, (char_u **)&name);
+      mb_copy_char((const char **)&p, &name);
     }
   }
   *name = NUL;
@@ -3987,7 +3987,7 @@ static int get_lit_string_tv(char **arg, typval_T *rettv, int evaluate)
       }
       ++p;
     }
-    mb_copy_char((const char_u **)&p, (char_u **)&str);
+    mb_copy_char((const char **)&p, &str);
   }
   *str = NUL;
   *arg = p + 1;
@@ -5092,7 +5092,7 @@ void common_function(typval_T *argvars, typval_T *rettv, bool is_funcref, FunPtr
 
   if ((use_string && vim_strchr(s, AUTOLOAD_CHAR) == NULL) || is_funcref) {
     name = s;
-    trans_name = (char *)trans_function_name((char_u **)&name, false,
+    trans_name = (char *)trans_function_name(&name, false,
                                              TFN_INT | TFN_QUIET | TFN_NO_AUTOLOAD
                                              | TFN_NO_DEREF, NULL, NULL);
     if (*name != NUL) {
diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index bb3418a392..e13046ef82 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -2557,7 +2557,7 @@ static void f_foldtextresult(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 
   foldinfo_T info = fold_info(curwin, lnum);
   if (info.fi_lines > 0) {
-    text = get_foldtext(curwin, lnum, lnum + (linenr_T)info.fi_lines - 1, info, buf);
+    text = get_foldtext(curwin, lnum, lnum + info.fi_lines - 1, info, buf);
     if (text == buf) {
       text = vim_strsave(text);
     }
@@ -3967,7 +3967,7 @@ static void f_globpath(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   if (file != NULL && !error) {
     garray_T ga;
     ga_init(&ga, (int)sizeof(char_u *), 10);
-    globpath((char_u *)tv_get_string(&argvars[0]), (char_u *)file, &ga, flags);
+    globpath((char *)tv_get_string(&argvars[0]), (char_u *)file, &ga, flags);
 
     if (rettv->v_type == VAR_STRING) {
       rettv->vval.v_string = ga_concat_strings_sep(&ga, "\n");
@@ -8266,10 +8266,10 @@ static void f_setqflist(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 }
 
 /// Translate a register type string to the yank type and block length
-static int get_yank_type(char_u **const pp, MotionType *const yank_type, long *const block_len)
+static int get_yank_type(char **const pp, MotionType *const yank_type, long *const block_len)
   FUNC_ATTR_NONNULL_ALL
 {
-  char *stropt = (char *)(*pp);
+  char *stropt = *pp;
   switch (*stropt) {
   case 'v':
   case 'c':  // character-wise selection
@@ -8291,7 +8291,7 @@ static int get_yank_type(char_u **const pp, MotionType *const yank_type, long *c
   default:
     return FAIL;
   }
-  *pp = (char_u *)stropt;
+  *pp = stropt;
   return OK;
 }
 
@@ -8323,7 +8323,7 @@ static void f_setreg(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 
     if (tv_dict_len(d) == 0) {
       // Empty dict, clear the register (like setreg(0, []))
-      char_u *lstval[2] = { NULL, NULL };
+      char *lstval[2] = { NULL, NULL };
       write_reg_contents_lst(regname, lstval, false, kMTUnknown, -1);
       return;
     }
@@ -8335,7 +8335,7 @@ static void f_setreg(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 
     const char *stropt = tv_dict_get_string(d, "regtype", false);
     if (stropt != NULL) {
-      const int ret = get_yank_type((char_u **)&stropt, &yank_type, &block_len);
+      const int ret = get_yank_type((char **)&stropt, &yank_type, &block_len);
 
       if (ret == FAIL || *(++stropt) != NUL) {
         semsg(_(e_invargval), "value");
@@ -8378,7 +8378,7 @@ static void f_setreg(typval_T *argvars, typval_T *rettv, FunPtr fptr)
         set_unnamed = true;
         break;
       default:
-        get_yank_type((char_u **)&stropt, &yank_type, &block_len);
+        get_yank_type((char **)&stropt, &yank_type, &block_len);
       }
     }
   }
@@ -8412,7 +8412,7 @@ static void f_setreg(typval_T *argvars, typval_T *rettv, FunPtr fptr)
     });
     *curval++ = NULL;
 
-    write_reg_contents_lst(regname, (char_u **)lstval, append, yank_type, (colnr_T)block_len);
+    write_reg_contents_lst(regname, lstval, append, yank_type, (colnr_T)block_len);
 
 free_lstval:
     while (curallocval > allocval) {
@@ -9632,20 +9632,20 @@ static int get_winnr(tabpage_T *tp, typval_T *argvar)
       }
     } else {
       // Extract the window count (if specified). e.g. winnr('3j')
-      char_u *endp;
-      long count = strtol((char *)arg, (char **)&endp, 10);
+      char *endp;
+      long count = strtol((char *)arg, &endp, 10);
       if (count <= 0) {
         // if count is not specified, default to 1
         count = 1;
       }
       if (endp != NULL && *endp != '\0') {
-        if (strequal((char *)endp, "j")) {
+        if (strequal(endp, "j")) {
           twin = win_vert_neighbor(tp, twin, false, count);
-        } else if (strequal((char *)endp, "k")) {
+        } else if (strequal(endp, "k")) {
           twin = win_vert_neighbor(tp, twin, true, count);
-        } else if (strequal((char *)endp, "h")) {
+        } else if (strequal(endp, "h")) {
           twin = win_horz_neighbor(tp, twin, true, count);
-        } else if (strequal((char *)endp, "l")) {
+        } else if (strequal(endp, "l")) {
           twin = win_horz_neighbor(tp, twin, false, count);
         } else {
           invalid_arg = true;
diff --git a/src/nvim/eval/userfunc.c b/src/nvim/eval/userfunc.c
index 6c437c1ff4..0ee44d59a9 100644
--- a/src/nvim/eval/userfunc.c
+++ b/src/nvim/eval/userfunc.c
@@ -75,12 +75,12 @@ hashtab_T *func_tbl_get(void)
 }
 
 /// Get function arguments.
-static int get_function_args(char_u **argp, char_u endchar, garray_T *newargs, int *varargs,
+static int get_function_args(char **argp, char_u endchar, garray_T *newargs, int *varargs,
                              garray_T *default_args, bool skip)
 {
   bool mustend = false;
-  char_u *arg = *argp;
-  char_u *p = arg;
+  char *arg = *argp;
+  char *p = arg;
   char_u c;
   int i;
 
@@ -97,7 +97,7 @@ static int get_function_args(char_u **argp, char_u endchar, garray_T *newargs, i
 
   // Isolate the arguments: "arg1, arg2, ...)"
   bool any_default = false;
-  while (*p != endchar) {
+  while (*p != (char)endchar) {
     if (p[0] == '.' && p[1] == '.' && p[2] == '.') {
       if (varargs != NULL) {
         *varargs = true;
@@ -119,44 +119,43 @@ static int get_function_args(char_u **argp, char_u endchar, garray_T *newargs, i
       }
       if (newargs != NULL) {
         ga_grow(newargs, 1);
-        c = *p;
+        c = (char_u)(*p);
         *p = NUL;
-        arg = vim_strsave(arg);
+        arg = xstrdup(arg);
 
         // Check for duplicate argument name.
         for (i = 0; i < newargs->ga_len; i++) {
-          if (STRCMP(((char_u **)(newargs->ga_data))[i], arg) == 0) {
+          if (STRCMP(((char **)(newargs->ga_data))[i], arg) == 0) {
             semsg(_("E853: Duplicate argument name: %s"), arg);
             xfree(arg);
             goto err_ret;
           }
         }
-        ((char_u **)(newargs->ga_data))[newargs->ga_len] = arg;
+        ((char **)(newargs->ga_data))[newargs->ga_len] = arg;
         newargs->ga_len++;
 
-        *p = c;
+        *p = (char)c;
       }
-      if (*skipwhite((char *)p) == '=' && default_args != NULL) {
+      if (*skipwhite(p) == '=' && default_args != NULL) {
         typval_T rettv;
 
         any_default = true;
-        p = (char_u *)skipwhite((char *)p) + 1;
-        p = (char_u *)skipwhite((char *)p);
-        char_u *expr = p;
-        if (eval1((char **)&p, &rettv, false) != FAIL) {
+        p = skipwhite(p) + 1;
+        p = skipwhite(p);
+        char_u *expr = (char_u *)p;
+        if (eval1(&p, &rettv, false) != FAIL) {
           ga_grow(default_args, 1);
 
           // trim trailing whitespace
-          while (p > expr && ascii_iswhite(p[-1])) {
+          while (p > (char *)expr && ascii_iswhite(p[-1])) {
             p--;
           }
-          c = *p;
+          c = (char_u)(*p);
           *p = NUL;
           expr = vim_strsave(expr);
-          ((char_u **)(default_args->ga_data))
-          [default_args->ga_len] = expr;
+          ((char **)(default_args->ga_data))[default_args->ga_len] = (char *)expr;
           default_args->ga_len++;
-          *p = c;
+          *p = (char)c;
         } else {
           mustend = true;
         }
@@ -170,15 +169,15 @@ static int get_function_args(char_u **argp, char_u endchar, garray_T *newargs, i
         mustend = true;
       }
     }
-    p = (char_u *)skipwhite((char *)p);
-    if (mustend && *p != endchar) {
+    p = skipwhite(p);
+    if (mustend && *p != (char)endchar) {
       if (!skip) {
         semsg(_(e_invarg2), *argp);
       }
       break;
     }
   }
-  if (*p != endchar) {
+  if (*p != (char)endchar) {
     goto err_ret;
   }
   p++;  // skip "endchar"
@@ -224,7 +223,7 @@ char_u *get_lambda_name(void)
 /// Parse a lambda expression and get a Funcref from "*arg".
 ///
 /// @return OK or FAIL.  Returns NOTDONE for dict or {expr}.
-int get_lambda_tv(char_u **arg, typval_T *rettv, bool evaluate)
+int get_lambda_tv(char **arg, typval_T *rettv, bool evaluate)
 {
   garray_T newargs = GA_EMPTY_INIT_VALUE;
   garray_T *pnewargs;
@@ -232,13 +231,13 @@ int get_lambda_tv(char_u **arg, typval_T *rettv, bool evaluate)
   partial_T *pt = NULL;
   int varargs;
   int ret;
-  char_u *start = (char_u *)skipwhite((char *)(*arg) + 1);
+  char_u *start = (char_u *)skipwhite(*arg + 1);
   char_u *s, *e;
   bool *old_eval_lavars = eval_lavars_used;
   bool eval_lavars = false;
 
   // First, check if this is a lambda expression. "->" must exists.
-  ret = get_function_args(&start, '-', NULL, NULL, NULL, true);
+  ret = get_function_args((char **)&start, '-', NULL, NULL, NULL, true);
   if (ret == FAIL || *start != '>') {
     return NOTDONE;
   }
@@ -249,7 +248,7 @@ int get_lambda_tv(char_u **arg, typval_T *rettv, bool evaluate)
   } else {
     pnewargs = NULL;
   }
-  *arg = (char_u *)skipwhite((char *)(*arg) + 1);
+  *arg = skipwhite(*arg + 1);
   ret = get_function_args(arg, '-', pnewargs, &varargs, NULL, false);
   if (ret == FAIL || **arg != '>') {
     goto errret;
@@ -261,14 +260,14 @@ int get_lambda_tv(char_u **arg, typval_T *rettv, bool evaluate)
   }
 
   // Get the start and the end of the expression.
-  *arg = (char_u *)skipwhite((char *)(*arg) + 1);
-  s = *arg;
-  ret = skip_expr((char **)arg);
+  *arg = skipwhite((*arg) + 1);
+  s = (char_u *)(*arg);
+  ret = skip_expr(arg);
   if (ret == FAIL) {
     goto errret;
   }
-  e = *arg;
-  *arg = (char_u *)skipwhite((char *)(*arg));
+  e = (char_u *)(*arg);
+  *arg = skipwhite(*arg);
   if (**arg != '}') {
     goto errret;
   }
@@ -290,7 +289,7 @@ int get_lambda_tv(char_u **arg, typval_T *rettv, bool evaluate)
     // Add "return " before the expression.
     size_t len = (size_t)(7 + e - s + 1);
     p = (char_u *)xmalloc(len);
-    ((char_u **)(newlines.ga_data))[newlines.ga_len++] = p;
+    ((char **)(newlines.ga_data))[newlines.ga_len++] = (char *)p;
     STRCPY(p, "return ");
     STRLCPY(p + 7, s, e - s + 1);
     if (strstr((char *)p + 7, "a:") == NULL) {
@@ -419,24 +418,22 @@ void emsg_funcname(char *ermsg, const char_u *name)
 /// @param funcexe  various values
 ///
 /// @return  OK or FAIL.
-int get_func_tv(const char_u *name, int len, typval_T *rettv, char_u **arg, funcexe_T *funcexe)
+int get_func_tv(const char_u *name, int len, typval_T *rettv, char **arg, funcexe_T *funcexe)
 {
-  char_u *argp;
+  char *argp;
   int ret = OK;
   typval_T argvars[MAX_FUNC_ARGS + 1];          // vars for arguments
   int argcount = 0;                     // number of arguments found
 
-  /*
-   * Get the arguments.
-   */
+  // Get the arguments.
   argp = *arg;
   while (argcount < MAX_FUNC_ARGS
          - (funcexe->partial == NULL ? 0 : funcexe->partial->pt_argc)) {
-    argp = (char_u *)skipwhite((char *)argp + 1);             // skip the '(' or ','
+    argp = skipwhite(argp + 1);             // skip the '(' or ','
     if (*argp == ')' || *argp == ',' || *argp == NUL) {
       break;
     }
-    if (eval1((char **)&argp, &argvars[argcount], funcexe->evaluate) == FAIL) {
+    if (eval1(&argp, &argvars[argcount], funcexe->evaluate) == FAIL) {
       ret = FAIL;
       break;
     }
@@ -480,7 +477,7 @@ int get_func_tv(const char_u *name, int len, typval_T *rettv, char_u **arg, func
     tv_clear(&argvars[argcount]);
   }
 
-  *arg = (char_u *)skipwhite((char *)argp);
+  *arg = skipwhite(argp);
   return ret;
 }
 
@@ -822,7 +819,7 @@ void call_user_func(ufunc_T *fp, int argcount, typval_T *argvars, typval_T *rett
   int ai;
   bool islambda = false;
   char_u numbuf[NUMBUFLEN];
-  char_u *name;
+  char *name;
   typval_T *tv_to_free[MAX_FUNC_ARGS];
   int tv_to_free_len = 0;
   proftime_T wait_start;
@@ -878,7 +875,7 @@ void call_user_func(ufunc_T *fp, int argcount, typval_T *argvars, typval_T *rett
     // some compiler that checks the destination size.
     v = (dictitem_T *)&fc->fixvar[fixvar_idx++];
 #ifndef __clang_analyzer__
-    name = v->di_key;
+    name = (char *)v->di_key;
     STRCPY(name, "self");
 #endif
     v->di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
@@ -904,7 +901,7 @@ void call_user_func(ufunc_T *fp, int argcount, typval_T *argvars, typval_T *rett
     // destination size.
     v = (dictitem_T *)&fc->fixvar[fixvar_idx++];
 #ifndef __clang_analyzer__
-    name = v->di_key;
+    name = (char *)v->di_key;
     STRCPY(name, "000");
 #endif
     v->di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
@@ -943,13 +940,13 @@ void call_user_func(ufunc_T *fp, int argcount, typval_T *argvars, typval_T *rett
       // evaluate named argument default expression
       isdefault = ai + fp->uf_def_args.ga_len >= 0 && i >= argcount;
       if (isdefault) {
-        char_u *default_expr = NULL;
+        char *default_expr = NULL;
         def_rettv.v_type = VAR_NUMBER;
         def_rettv.vval.v_number = -1;
 
-        default_expr = ((char_u **)(fp->uf_def_args.ga_data))
+        default_expr = ((char **)(fp->uf_def_args.ga_data))
                        [ai + fp->uf_def_args.ga_len];
-        if (eval1((char **)&default_expr, &def_rettv, true) == FAIL) {
+        if (eval1(&default_expr, &def_rettv, true) == FAIL) {
           default_arg_err = true;
           break;
         }
@@ -961,7 +958,7 @@ void call_user_func(ufunc_T *fp, int argcount, typval_T *argvars, typval_T *rett
       }
       // "..." argument a:1, a:2, etc.
       snprintf((char *)numbuf, sizeof(numbuf), "%d", ai + 1);
-      name = numbuf;
+      name = (char *)numbuf;
     }
     if (fixvar_idx < FIXVAR_CNT && STRLEN(name) <= VAR_SHORT_LEN) {
       v = (dictitem_T *)&fc->fixvar[fixvar_idx++];
@@ -1105,12 +1102,12 @@ void call_user_func(ufunc_T *fp, int argcount, typval_T *argvars, typval_T *rett
   if (default_arg_err && (fp->uf_flags & FC_ABORT)) {
     did_emsg = true;
   } else if (islambda) {
-    char_u *p = *(char_u **)fp->uf_lines.ga_data + 7;
+    char *p = *(char **)fp->uf_lines.ga_data + 7;
 
     // A Lambda always has the command "return {expr}".  It is much faster
     // to evaluate {expr} directly.
     ex_nesting_level++;
-    (void)eval1((char **)&p, rettv, true);
+    (void)eval1(&p, rettv, true);
     ex_nesting_level--;
   } else {
     // call do_cmdline() to execute the lines
@@ -1699,7 +1696,7 @@ static void list_func_head(ufunc_T *fp, int indent, bool force)
 /// @param partial  return: partial of a FuncRef
 ///
 /// @return the function name in allocated memory, or NULL for failure.
-char_u *trans_function_name(char_u **pp, bool skip, int flags, funcdict_T *fdp, partial_T **partial)
+char_u *trans_function_name(char **pp, bool skip, int flags, funcdict_T *fdp, partial_T **partial)
   FUNC_ATTR_NONNULL_ARG(1)
 {
   char_u *name = NULL;
@@ -1712,11 +1709,11 @@ char_u *trans_function_name(char_u **pp, bool skip, int flags, funcdict_T *fdp,
   if (fdp != NULL) {
     CLEAR_POINTER(fdp);
   }
-  start = *pp;
+  start = (char_u *)(*pp);
 
   // Check for hard coded <SNR>: already translated function ID (from a user
   // command).
-  if ((*pp)[0] == K_SPECIAL && (*pp)[1] == KS_EXTRA
+  if ((unsigned char)(*pp)[0] == K_SPECIAL && (unsigned char)(*pp)[1] == KS_EXTRA
       && (*pp)[2] == KE_SNR) {
     *pp += 3;
     len = get_id_len((const char **)pp) + 3;
@@ -1750,7 +1747,7 @@ char_u *trans_function_name(char_u **pp, bool skip, int flags, funcdict_T *fdp,
         semsg(_(e_invarg2), start);
       }
     } else {
-      *pp = (char_u *)find_name_end((char *)start, NULL, NULL, FNE_INCL_BR);
+      *pp = (char *)find_name_end((char *)start, NULL, NULL, FNE_INCL_BR);
     }
     goto theend;
   }
@@ -1764,7 +1761,7 @@ char_u *trans_function_name(char_u **pp, bool skip, int flags, funcdict_T *fdp,
     }
     if (lv.ll_tv->v_type == VAR_FUNC && lv.ll_tv->vval.v_string != NULL) {
       name = vim_strsave((char_u *)lv.ll_tv->vval.v_string);
-      *pp = (char_u *)end;
+      *pp = (char *)end;
     } else if (lv.ll_tv->v_type == VAR_PARTIAL
                && lv.ll_tv->vval.v_partial != NULL) {
       if (is_luafunc(lv.ll_tv->vval.v_partial) && *end == '.') {
@@ -1775,10 +1772,10 @@ char_u *trans_function_name(char_u **pp, bool skip, int flags, funcdict_T *fdp,
         }
         name = xmallocz((size_t)len);
         memcpy(name, end + 1, (size_t)len);
-        *pp = (char_u *)end + 1 + len;
+        *pp = (char *)end + 1 + len;
       } else {
         name = vim_strsave((char_u *)partial_name(lv.ll_tv->vval.v_partial));
-        *pp = (char_u *)end;
+        *pp = (char *)end;
       }
       if (partial != NULL) {
         *partial = lv.ll_tv->vval.v_partial;
@@ -1789,7 +1786,7 @@ char_u *trans_function_name(char_u **pp, bool skip, int flags, funcdict_T *fdp,
                                             || fdp->fd_newkey == NULL)) {
         emsg(_(e_funcref));
       } else {
-        *pp = (char_u *)end;
+        *pp = (char *)end;
       }
       name = NULL;
     }
@@ -1798,7 +1795,7 @@ char_u *trans_function_name(char_u **pp, bool skip, int flags, funcdict_T *fdp,
 
   if (lv.ll_name == NULL) {
     // Error found, but continue after the function name.
-    *pp = (char_u *)end;
+    *pp = (char *)end;
     goto theend;
   }
 
@@ -1811,16 +1808,16 @@ char_u *trans_function_name(char_u **pp, bool skip, int flags, funcdict_T *fdp,
       name = NULL;
     }
   } else if (!(flags & TFN_NO_DEREF)) {
-    len = (int)(end - *pp);
+    len = (int)(end - (char_u *)(*pp));