Merge remote-tracking branch 'upstream/master' into usermarksusermarks

1 files changed, 654 insertions, 649 deletions

diff --git a/src/nvim/spellfile.c b/src/nvim/spellfile.c
index be1373f617..44414ca1a5 100644
--- a/src/nvim/spellfile.c
+++ b/src/nvim/spellfile.c
@@ -226,82 +226,101 @@
 //                          stored as an offset to the previous number in as
 //                          few bytes as possible, see offset2bytes())
 
-#include <stdint.h>
+#include <assert.h>
+#include <ctype.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <stdbool.h>
 #include <stdio.h>
-#include <wctype.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
 
+#include "auto/config.h"
 #include "nvim/arglist.h"
 #include "nvim/ascii.h"
 #include "nvim/buffer.h"
 #include "nvim/charset.h"
 #include "nvim/drawscreen.h"
-#include "nvim/ex_cmds2.h"
+#include "nvim/ex_cmds_defs.h"
 #include "nvim/fileio.h"
+#include "nvim/garray.h"
+#include "nvim/gettext.h"
+#include "nvim/globals.h"
+#include "nvim/hashtab.h"
+#include "nvim/macros.h"
+#include "nvim/mbyte.h"
 #include "nvim/memline.h"
 #include "nvim/memory.h"
+#include "nvim/message.h"
 #include "nvim/option.h"
 #include "nvim/os/input.h"
 #include "nvim/os/os.h"
+#include "nvim/os/time.h"
 #include "nvim/path.h"
+#include "nvim/pos.h"
 #include "nvim/regexp.h"
 #include "nvim/runtime.h"
 #include "nvim/spell.h"
 #include "nvim/spell_defs.h"
 #include "nvim/spellfile.h"
+#include "nvim/strings.h"
+#include "nvim/types.h"
 #include "nvim/ui.h"
 #include "nvim/undo.h"
 #include "nvim/vim.h"
 
-#ifndef UNIX            // it's in os/unix_defs.h for Unix
-# include <time.h>      // for time_t
-#endif
-
 // Special byte values for <byte>.  Some are only used in the tree for
 // postponed prefixes, some only in the other trees.  This is a bit messy...
-#define BY_NOFLAGS      0       // end of word without flags or region; for
-                                // postponed prefix: no <pflags>
-#define BY_INDEX        1       // child is shared, index follows
-#define BY_FLAGS        2       // end of word, <flags> byte follows; for
-                                // postponed prefix: <pflags> follows
-#define BY_FLAGS2       3       // end of word, <flags> and <flags2> bytes
-                                // follow; never used in prefix tree
-#define BY_SPECIAL  BY_FLAGS2   // highest special byte value
+enum {
+  BY_NOFLAGS = 0,  // end of word without flags or region; for postponed prefix: no <pflags>
+  BY_INDEX = 1,    // child is shared, index follows
+  BY_FLAGS = 2,    // end of word, <flags> byte follows; for postponed prefix: <pflags> follows
+  BY_FLAGS2 = 3,   // end of word, <flags> and <flags2> bytes follow; never used in prefix tree
+  BY_SPECIAL = BY_FLAGS2,  // highest special byte value
+};
 
 #define ZERO_FLAG   65009       // used when flag is zero: "0"
 
 // Flags used in .spl file for soundsalike flags.
-#define SAL_F0LLOWUP            1
-#define SAL_COLLAPSE            2
-#define SAL_REM_ACCENTS         4
+enum {
+  SAL_F0LLOWUP = 1,
+  SAL_COLLAPSE = 2,
+  SAL_REM_ACCENTS = 4,
+};
 
 #define VIMSPELLMAGIC "VIMspell"  // string at start of Vim spell file
 #define VIMSPELLMAGICL (sizeof(VIMSPELLMAGIC) - 1)
 #define VIMSPELLVERSION 50
 
 // Section IDs.  Only renumber them when VIMSPELLVERSION changes!
-#define SN_REGION       0       // <regionname> section
-#define SN_CHARFLAGS    1       // charflags section
-#define SN_MIDWORD      2       // <midword> section
-#define SN_PREFCOND     3       // <prefcond> section
-#define SN_REP          4       // REP items section
-#define SN_SAL          5       // SAL items section
-#define SN_SOFO         6       // soundfolding section
-#define SN_MAP          7       // MAP items section
-#define SN_COMPOUND     8       // compound words section
-#define SN_SYLLABLE     9       // syllable section
-#define SN_NOBREAK      10      // NOBREAK section
-#define SN_SUGFILE      11      // timestamp for .sug file
-#define SN_REPSAL       12      // REPSAL items section
-#define SN_WORDS        13      // common words
-#define SN_NOSPLITSUGS  14      // don't split word for suggestions
-#define SN_INFO         15      // info section
-#define SN_NOCOMPOUNDSUGS 16    // don't compound for suggestions
-#define SN_END          255     // end of sections
+enum {
+  SN_REGION = 0,           // <regionname> section
+  SN_CHARFLAGS = 1,        // charflags section
+  SN_MIDWORD = 2,          // <midword> section
+  SN_PREFCOND = 3,         // <prefcond> section
+  SN_REP = 4,              // REP items section
+  SN_SAL = 5,              // SAL items section
+  SN_SOFO = 6,             // soundfolding section
+  SN_MAP = 7,              // MAP items section
+  SN_COMPOUND = 8,         // compound words section
+  SN_SYLLABLE = 9,         // syllable section
+  SN_NOBREAK = 10,         // NOBREAK section
+  SN_SUGFILE = 11,         // timestamp for .sug file
+  SN_REPSAL = 12,          // REPSAL items section
+  SN_WORDS = 13,           // common words
+  SN_NOSPLITSUGS = 14,     // don't split word for suggestions
+  SN_INFO = 15,            // info section
+  SN_NOCOMPOUNDSUGS = 16,  // don't compound for suggestions
+  SN_END = 255,            // end of sections
+};
 
 #define SNF_REQUIRED    1       // <sectionflags>: required section
 
-#define CF_WORD         0x01
-#define CF_UPPER        0x02
+enum {
+  CF_WORD = 0x01,
+  CF_UPPER = 0x02,
+};
 
 static char *e_spell_trunc = N_("E758: Truncated spell file");
 static char *e_illegal_character_in_word = N_("E1280: Illegal character in word");
@@ -313,7 +332,7 @@ static char *msg_compressing = N_("Compressing word tree...");
                                 // and .dic file.
 // Main structure to store the contents of a ".aff" file.
 typedef struct afffile_S {
-  char_u *af_enc;          // "SET", normalized, alloc'ed string or NULL
+  char *af_enc;                 // "SET", normalized, alloc'ed string or NULL
   int af_flagtype;              // AFT_CHAR, AFT_LONG, AFT_NUM or AFT_CAPLONG
   unsigned af_rare;             // RARE ID for rare word
   unsigned af_keepcase;         // KEEPCASE ID for keep-case word
@@ -341,12 +360,12 @@ typedef struct afffile_S {
 typedef struct affentry_S affentry_T;
 // Affix entry from ".aff" file.  Used for prefixes and suffixes.
 struct affentry_S {
-  affentry_T *ae_next;         // next affix with same name/number
-  char_u *ae_chop;         // text to chop off basic word (can be NULL)
-  char_u *ae_add;          // text to add to basic word (can be NULL)
-  char_u *ae_flags;        // flags on the affix (can be NULL)
-  char_u *ae_cond;         // condition (NULL for ".")
-  regprog_T *ae_prog;         // regexp program for ae_cond or NULL
+  affentry_T *ae_next;          // next affix with same name/number
+  char *ae_chop;                // text to chop off basic word (can be NULL)
+  char *ae_add;                 // text to add to basic word (can be NULL)
+  char *ae_flags;               // flags on the affix (can be NULL)
+  char *ae_cond;                // condition (NULL for ".")
+  regprog_T *ae_prog;           // regexp program for ae_cond or NULL
   char ae_compforbid;           // COMPOUNDFORBIDFLAG found
   char ae_comppermit;           // COMPOUNDPERMITFLAG found
 };
@@ -355,12 +374,12 @@ struct affentry_S {
 
 // Affix header from ".aff" file.  Used for af_pref and af_suff.
 typedef struct affheader_S {
-  char_u ah_key[AH_KEY_LEN];    // key for hashtab == name of affix
+  char ah_key[AH_KEY_LEN];      // key for hashtab == name of affix
   unsigned ah_flag;             // affix name as number, uses "af_flagtype"
   int ah_newID;                 // prefix ID after renumbering; 0 if not used
   int ah_combine;               // suffix may combine with prefix
   int ah_follows;               // another affix block should be following
-  affentry_T *ah_first;        // first affix entry
+  affentry_T *ah_first;         // first affix entry
 } affheader_T;
 
 #define HI2AH(hi)   ((affheader_T *)(hi)->hi_key)
@@ -415,7 +434,7 @@ struct wordnode_S {
   // "wn_region" the LSW of the wordnr.
   char_u wn_affixID;            // supported/required prefix ID or 0
   uint16_t wn_flags;            // WF_ flags
-  short wn_region;              // region mask
+  int16_t wn_region;            // region mask
 
 #ifdef SPELL_PRINTTREE
   int wn_nr;                    // sequence nr for printing
@@ -440,7 +459,7 @@ typedef struct spellinfo_S {
 
   sblock_T *si_blocks;       // memory blocks used
   long si_blocks_cnt;           // memory blocks allocated
-  int si_did_emsg;              // TRUE when ran out of memory
+  int si_did_emsg;              // true when ran out of memory
 
   long si_compress_cnt;         // words to add before lowering
                                 // compression limit
@@ -454,13 +473,13 @@ typedef struct spellinfo_S {
 
   int si_ascii;                 // handling only ASCII words
   int si_add;                   // addition file
-  int si_clear_chartab;             // when TRUE clear char tables
+  int si_clear_chartab;             // when true clear char tables
   int si_region;                // region mask
   vimconv_T si_conv;            // for conversion to 'encoding'
   int si_memtot;                // runtime memory used
   int si_verbose;               // verbose messages
   int si_msg_count;             // number of words added since last message
-  char_u *si_info;         // info text chars or NULL
+  char *si_info;                // info text chars or NULL
   int si_region_count;          // number of regions supported (1 when there
                                 // are no regions)
   char_u si_region_name[MAXREGIONS * 2 + 1];
@@ -470,8 +489,8 @@ typedef struct spellinfo_S {
   garray_T si_rep;              // list of fromto_T entries from REP lines
   garray_T si_repsal;           // list of fromto_T entries from REPSAL lines
   garray_T si_sal;              // list of fromto_T entries from SAL lines
-  char_u *si_sofofr;       // SOFOFROM text
-  char_u *si_sofoto;       // SOFOTO text
+  char *si_sofofr;              // SOFOFROM text
+  char *si_sofoto;              // SOFOTO text
   int si_nosugfile;             // NOSUGFILE item found
   int si_nosplitsugs;           // NOSPLITSUGS item found
   int si_nocompoundsugs;        // NOCOMPOUNDSUGS item found
@@ -481,16 +500,16 @@ typedef struct spellinfo_S {
   time_t si_sugtime;            // timestamp for .sug file
   int si_rem_accents;           // soundsalike: remove accents
   garray_T si_map;              // MAP info concatenated
-  char_u *si_midword;      // MIDWORD chars or NULL
+  char *si_midword;             // MIDWORD chars or NULL
   int si_compmax;               // max nr of words for compounding
   int si_compminlen;            // minimal length for compounding
   int si_compsylmax;            // max nr of syllables for compounding
   int si_compoptions;           // COMP_ flags
   garray_T si_comppat;          // CHECKCOMPOUNDPATTERN items, each stored as
                                 // a string
-  char_u *si_compflags;    // flags used for compounding
+  char *si_compflags;           // flags used for compounding
   char_u si_nobreak;            // NOBREAK
-  char_u *si_syllable;     // syllable string
+  char *si_syllable;            // syllable string
   garray_T si_prefcond;         // table with conditions for postponed
                                 // prefixes, each stored as a string
   int si_newprefID;             // current value for ah_newID
@@ -552,7 +571,7 @@ static inline int spell_check_magic_string(FILE *const fd)
   FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_ALWAYS_INLINE
 {
   char buf[VIMSPELLMAGICL];
-  SPELL_READ_BYTES(buf, VIMSPELLMAGICL, fd,; );
+  SPELL_READ_BYTES(buf, VIMSPELLMAGICL, fd,; );  // NOLINT(whitespace/parens)
   if (memcmp(buf, VIMSPELLMAGIC, VIMSPELLMAGICL) != 0) {
     return SP_FORMERROR;
   }
@@ -572,10 +591,10 @@ static inline int spell_check_magic_string(FILE *const fd)
 /// @param silent  no error if file doesn't exist
 ///
 /// @return  the slang_T the spell file was loaded into.  NULL for error.
-slang_T *spell_load_file(char_u *fname, char_u *lang, slang_T *old_lp, bool silent)
+slang_T *spell_load_file(char *fname, char *lang, slang_T *old_lp, bool silent)
 {
   FILE *fd;
-  char_u *p;
+  char *p;
   int n;
   int len;
   slang_T *lp = NULL;
@@ -583,7 +602,7 @@ slang_T *spell_load_file(char_u *fname, char_u *lang, slang_T *old_lp, bool sile
   int res;
   bool did_estack_push = false;
 
-  fd = os_fopen((char *)fname, "r");
+  fd = os_fopen(fname, "r");
   if (fd == NULL) {
     if (!silent) {
       semsg(_(e_notopen), fname);
@@ -604,16 +623,16 @@ slang_T *spell_load_file(char_u *fname, char_u *lang, slang_T *old_lp, bool sile
     lp = slang_alloc(lang);
 
     // Remember the file name, used to reload the file when it's updated.
-    lp->sl_fname = vim_strsave(fname);
+    lp->sl_fname = xstrdup(fname);
 
     // Check for .add.spl.
-    lp->sl_add = strstr(path_tail((char *)fname), SPL_FNAME_ADD) != NULL;
+    lp->sl_add = strstr(path_tail(fname), SPL_FNAME_ADD) != NULL;
   } else {
     lp = old_lp;
   }
 
   // Set sourcing_name, so that error messages mention the file name.
-  estack_push(ETYPE_SPELL, (char *)fname, 0);
+  estack_push(ETYPE_SPELL, fname, 0);
   did_estack_push = true;
 
   // <HEADER>: <fileID>
@@ -697,7 +716,7 @@ slang_T *spell_load_file(char_u *fname, char_u *lang, slang_T *old_lp, bool sile
       break;
 
     case SN_MAP:
-      p = READ_STRING(fd, len);                         // <mapstr>
+      p = (char *)READ_STRING(fd, len);                         // <mapstr>
       if (p == NULL) {
         goto endFAIL;
       }
@@ -819,7 +838,7 @@ endOK:
 
 // Fill in the wordcount fields for a trie.
 // Returns the total number of words.
-static void tree_count_words(char_u *byts, idx_T *idxs)
+static void tree_count_words(const char_u *byts, idx_T *idxs)
 {
   int depth;
   idx_T arridx[MAXWLEN];
@@ -845,12 +864,12 @@ static void tree_count_words(char_u *byts, idx_T *idxs)
     } else {
       // Do one more byte at this node.
       n = arridx[depth] + curi[depth];
-      ++curi[depth];
+      curi[depth]++;
 
       c = byts[n];
       if (c == 0) {
         // End of word, count it.
-        ++wordcount[depth];
+        wordcount[depth]++;
 
         // Skip over any other NUL bytes (same word with different
         // flags).
@@ -869,14 +888,14 @@ static void tree_count_words(char_u *byts, idx_T *idxs)
   }
 }
 
-// Load the .sug files for languages that have one and weren't loaded yet.
+/// Load the .sug files for languages that have one and weren't loaded yet.
 void suggest_load_files(void)
 {
   langp_T *lp;
   slang_T *slang;
-  char_u *dotp;
+  char *dotp;
   FILE *fd;
-  char_u buf[MAXWLEN];
+  char buf[MAXWLEN];
   int i;
   time_t timestamp;
   int wcount;
@@ -885,7 +904,7 @@ void suggest_load_files(void)
   int c;
 
   // Do this for all languages that support sound folding.
-  for (int lpi = 0; lpi < curwin->w_s->b_langp.ga_len; ++lpi) {
+  for (int lpi = 0; lpi < curwin->w_s->b_langp.ga_len; lpi++) {
     lp = LANGP_ENTRY(curwin->w_s->b_langp, lpi);
     slang = lp->lp_slang;
     if (slang->sl_sugtime != 0 && !slang->sl_sugloaded) {
@@ -894,21 +913,21 @@ void suggest_load_files(void)
       // don't try again and again.
       slang->sl_sugloaded = true;
 
-      dotp = STRRCHR(slang->sl_fname, '.');
-      if (dotp == NULL || FNAMECMP(dotp, ".spl") != 0) {
+      dotp = strrchr(slang->sl_fname, '.');
+      if (dotp == NULL || path_fnamecmp(dotp, ".spl") != 0) {
         continue;
       }
       STRCPY(dotp, ".sug");
-      fd = os_fopen((char *)slang->sl_fname, "r");
+      fd = os_fopen(slang->sl_fname, "r");
       if (fd == NULL) {
         goto nextone;
       }
 
       // <SUGHEADER>: <fileID> <versionnr> <timestamp>
       for (i = 0; i < VIMSUGMAGICL; i++) {
-        buf[i] = (char_u)getc(fd);                              // <fileID>
+        buf[i] = (char)getc(fd);                              // <fileID>
       }
-      if (STRNCMP(buf, VIMSUGMAGIC, VIMSUGMAGICL) != 0) {
+      if (strncmp(buf, VIMSUGMAGIC, VIMSUGMAGICL) != 0) {
         semsg(_("E778: This does not look like a .sug file: %s"),
               slang->sl_fname);
         goto nextone;
@@ -960,7 +979,7 @@ someerror:
       // Read all the wordnr lists into the buffer, one NUL terminated
       // list per line.
       ga_init(&ga, 1, 100);
-      for (wordnr = 0; wordnr < wcount; ++wordnr) {
+      for (wordnr = 0; wordnr < wcount; wordnr++) {
         ga.ga_len = 0;
         for (;;) {
           c = getc(fd);                                     // <sugline>
@@ -981,8 +1000,8 @@ someerror:
 
       // Need to put word counts in the word tries, so that we can find
       // a word by its number.
-      tree_count_words(slang->sl_fbyts, slang->sl_fidxs);
-      tree_count_words(slang->sl_sbyts, slang->sl_sidxs);
+      tree_count_words((char_u *)slang->sl_fbyts, slang->sl_fidxs);
+      tree_count_words((char_u *)slang->sl_sbyts, slang->sl_sidxs);
 
 nextone:
       if (fd != NULL) {
@@ -1031,7 +1050,7 @@ static int read_region_section(FILE *fd, slang_T *lp, int len)
   if (len > MAXREGIONS * 2) {
     return SP_FORMERROR;
   }
-  SPELL_READ_NONNUL_BYTES((char *)lp->sl_regions, (size_t)len, fd,; );
+  SPELL_READ_NONNUL_BYTES(lp->sl_regions, (size_t)len, fd,; );  // NOLINT(whitespace/parens)
   lp->sl_regions[len] = NUL;
   return 0;
 }
@@ -1041,12 +1060,12 @@ static int read_region_section(FILE *fd, slang_T *lp, int len)
 // Return SP_*ERROR flags.
 static int read_charflags_section(FILE *fd)
 {
-  char_u *flags;
+  char *flags;
   char_u *fol;
   int flagslen, follen;
 
   // <charflagslen> <charflags>
-  flags = read_cnt_string(fd, 1, &flagslen);
+  flags = (char *)read_cnt_string(fd, 1, &flagslen);
   if (flagslen < 0) {
     return flagslen;
   }
@@ -1060,7 +1079,7 @@ static int read_charflags_section(FILE *fd)
 
   // Set the word-char flags and fill SPELL_ISUPPER() table.
   if (flags != NULL && fol != NULL) {
-    set_spell_charflags(flags, flagslen, fol);
+    set_spell_charflags((char_u *)flags, flagslen, (char *)fol);
   }
 
   xfree(flags);
@@ -1098,7 +1117,7 @@ static int read_prefcond_section(FILE *fd, slang_T *lp)
     if (n > 0) {
       char buf[MAXWLEN + 1];
       buf[0] = '^';  // always match at one position only
-      SPELL_READ_NONNUL_BYTES(buf + 1, (size_t)n, fd,; );
+      SPELL_READ_NONNUL_BYTES(buf + 1, (size_t)n, fd,; );  // NOLINT(whitespace/parens)
       buf[n + 1] = NUL;
       lp->sl_prefprog[i] = vim_regcomp(buf, RE_MAGIC | RE_STRING);
     }
@@ -1121,17 +1140,17 @@ static int read_rep_section(FILE *fd, garray_T *gap, int16_t *first)
   ga_grow(gap, cnt);
 
   // <rep> : <repfromlen> <repfrom> <reptolen> <repto>
-  for (; gap->ga_len < cnt; ++gap->ga_len) {
+  for (; gap->ga_len < cnt; gap->ga_len++) {
     int c;
     ftp = &((fromto_T *)gap->ga_data)[gap->ga_len];
-    ftp->ft_from = read_cnt_string(fd, 1, &c);
+    ftp->ft_from = (char *)read_cnt_string(fd, 1, &c);
     if (c < 0) {
       return c;
     }
     if (c == 0) {
       return SP_FORMERROR;
     }
-    ftp->ft_to = read_cnt_string(fd, 1, &c);
+    ftp->ft_to = (char *)read_cnt_string(fd, 1, &c);
     if (c <= 0) {
       xfree(ftp->ft_from);
       if (c < 0) {
@@ -1142,13 +1161,13 @@ static int read_rep_section(FILE *fd, garray_T *gap, int16_t *first)
   }
 
   // Fill the first-index table.
-  for (int i = 0; i < 256; ++i) {
+  for (int i = 0; i < 256; i++) {
     first[i] = -1;
   }
-  for (int i = 0; i < gap->ga_len; ++i) {
+  for (int i = 0; i < gap->ga_len; i++) {
     ftp = &((fromto_T *)gap->ga_data)[i];
-    if (first[*ftp->ft_from] == -1) {
-      first[*ftp->ft_from] = (int16_t)i;
+    if (first[(uint8_t)(*ftp->ft_from)] == -1) {
+      first[(uint8_t)(*ftp->ft_from)] = (int16_t)i;
     }
   }
   return 0;
@@ -1196,24 +1215,24 @@ static int read_sal_section(FILE *fd, slang_T *slang)
       return SP_TRUNCERROR;
     }
     p = xmalloc((size_t)ccnt + 2);
-    smp->sm_lead = p;
+    smp->sm_lead = (char *)p;
 
     // Read up to the first special char into sm_lead.
     int i = 0;
-    for (; i < ccnt; ++i) {
+    for (; i < ccnt; i++) {
       c = getc(fd);                             // <salfrom>
       if (vim_strchr("0123456789(-<^$", c) != NULL) {
         break;
       }
       *p++ = (char_u)c;
     }
-    smp->sm_leadlen = (int)(p - smp->sm_lead);
+    smp->sm_leadlen = (int)(p - (char_u *)smp->sm_lead);
     *p++ = NUL;
 
     // Put (abc) chars in sm_oneof, if any.
     if (c == '(') {
       smp->sm_oneof = p;
-      for (++i; i < ccnt; ++i) {
+      for (++i; i < ccnt; i++) {
         c = getc(fd);                           // <salfrom>
         if (c == ')') {
           break;
@@ -1229,7 +1248,7 @@ static int read_sal_section(FILE *fd, slang_T *slang)
     }
 
     // Any following chars go in sm_rules.
-    smp->sm_rules = p;
+    smp->sm_rules = (char *)p;
     if (i < ccnt) {
       // store the char we got while checking for end of sm_lead
       *p++ = (char_u)c;
@@ -1244,7 +1263,7 @@ static int read_sal_section(FILE *fd, slang_T *slang)
     *p++ = NUL;
 
     // <saltolen> <salto>
-    smp->sm_to = read_cnt_string(fd, 1, &ccnt);
+    smp->sm_to = (char *)read_cnt_string(fd, 1, &ccnt);
     if (ccnt < 0) {
       xfree(smp->sm_lead);
       return ccnt;
@@ -1256,7 +1275,7 @@ static int read_sal_section(FILE *fd, slang_T *slang)
     if (smp->sm_oneof == NULL) {
       smp->sm_oneof_w = NULL;
     } else {
-      smp->sm_oneof_w = mb_str2wide(smp->sm_oneof);
+      smp->sm_oneof_w = mb_str2wide((char *)smp->sm_oneof);
     }
     if (smp->sm_to == NULL) {
       smp->sm_to_w = NULL;
@@ -1271,12 +1290,12 @@ static int read_sal_section(FILE *fd, slang_T *slang)
     smp = &((salitem_T *)gap->ga_data)[gap->ga_len];
     p = xmalloc(1);
     p[0] = NUL;
-    smp->sm_lead = p;
+    smp->sm_lead = (char *)p;
     smp->sm_lead_w = mb_str2wide(smp->sm_lead);
     smp->sm_leadlen = 0;
     smp->sm_oneof = NULL;
     smp->sm_oneof_w = NULL;
-    smp->sm_rules = p;
+    smp->sm_rules = (char *)p;
     smp->sm_to = NULL;
     smp->sm_to_w = NULL;
     gap->ga_len++;
@@ -1299,7 +1318,7 @@ static int read_words_section(FILE *fd, slang_T *lp, int len)
 
   while (done < len) {
     // Read one word at a time.
-    for (i = 0;; ++i) {
+    for (i = 0;; i++) {
       c = getc(fd);
       if (c == EOF) {
         return SP_TRUNCERROR;
@@ -1314,7 +1333,7 @@ static int read_words_section(FILE *fd, slang_T *lp, int len)
     }
 
     // Init the count to 10.
-    count_common_word(lp, word, -1, 10);
+    count_common_word(lp, (char *)word, -1, 10);
     done += i + 1;
   }
   return 0;
@@ -1325,19 +1344,19 @@ static int read_words_section(FILE *fd, slang_T *lp, int len)
 static int read_sofo_section(FILE *fd, slang_T *slang)
 {
   int cnt;
-  char_u *from, *to;
+  char *from, *to;
   int res;
 
   slang->sl_sofo = true;
 
   // <sofofromlen> <sofofrom>
-  from = read_cnt_string(fd, 2, &cnt);
+  from = (char *)read_cnt_string(fd, 2, &cnt);
   if (cnt < 0) {
     return cnt;
   }
 
   // <sofotolen> <sofoto>
-  to = read_cnt_string(fd, 2, &cnt);
+  to = (char *)read_cnt_string(fd, 2, &cnt);
   if (cnt < 0) {
     xfree(from);
     return cnt;
@@ -1407,7 +1426,7 @@ static int read_compound(FILE *fd, slang_T *slang, int len)
       return SP_TRUNCERROR;
     }
     todo -= 2;
-    ga_init(gap, sizeof(char_u *), c);
+    ga_init(gap, sizeof(char *), c);
     ga_grow(gap, c);
     while (--c >= 0) {
       ((char **)(gap->ga_data))[gap->ga_len++] = (char *)read_cnt_string(fd, 1, &cnt);
@@ -1428,25 +1447,25 @@ static int read_compound(FILE *fd, slang_T *slang, int len)
   // Conversion to utf-8 may double the size.
   c = todo * 2 + 7;
   c += todo * 2;
-  char_u *pat = xmalloc((size_t)c);
+  char *pat = xmalloc((size_t)c);
 
   // We also need a list of all flags that can appear at the start and one
   // for all flags.
-  char_u *cp = xmalloc((size_t)todo + 1);
+  uint8_t *cp = xmalloc((size_t)todo + 1);
   slang->sl_compstartflags = cp;
   *cp = NUL;
 
-  char_u *ap = xmalloc((size_t)todo + 1);
+  uint8_t *ap = xmalloc((size_t)todo + 1);
   slang->sl_compallflags = ap;
   *ap = NUL;
 
   // And a list of all patterns in their original form, for checking whether
   // compounding may work in match_compoundrule().  This is freed when we
   // encounter a wildcard, the check doesn't work then.
-  char_u *crp = xmalloc((size_t)todo + 1);
+  uint8_t *crp = xmalloc((size_t)todo + 1);
   slang->sl_comprules = crp;
 
-  char_u *pp = pat;
+  char_u *pp = (char_u *)pat;
   *pp++ = '^';
   *pp++ = '\\';
   *pp++ = '(';
@@ -1515,7 +1534,7 @@ static int read_compound(FILE *fd, slang_T *slang, int len)
     *crp = NUL;
   }
 
-  slang->sl_compprog = vim_regcomp((char *)pat, RE_MAGIC + RE_STRING + RE_STRICT);
+  slang->sl_compprog = vim_regcomp(pat, RE_MAGIC + RE_STRING + RE_STRICT);
   xfree(pat);
   if (slang->sl_compprog == NULL) {
     return SP_FORMERROR;
@@ -1526,10 +1545,10 @@ static int read_compound(FILE *fd, slang_T *slang, int len)
 
 // Set the SOFOFROM and SOFOTO items in language "lp".
 // Returns SP_*ERROR flags when there is something wrong.
-static int set_sofo(slang_T *lp, char_u *from, char_u *to)
+static int set_sofo(slang_T *lp, char *from, char *to)
 {
-  char_u *s;
-  char_u *p;
+  char *s;
+  char *p;
 
   // Use "sl_sal" as an array with 256 pointers to a list of wide
   // characters.  The index is the low byte of the character.
@@ -1544,7 +1563,7 @@ static int set_sofo(slang_T *lp, char_u *from, char_u *to)
   // First count the number of items for each list.  Temporarily use
   // sl_sal_first[] for this.
   for (p = from, s = to; *p != NUL && *s != NUL;) {
-    const int c = mb_cptr2char_adv((const char_u **)&p);
+    const int c = mb_cptr2char_adv((const char **)&p);
     MB_CPTR_ADV(s);
     if (c >= 256) {
       lp->sl_sal_first[c & 0xff]++;
@@ -1567,8 +1586,8 @@ static int set_sofo(slang_T *lp, char_u *from, char_u *to)
   // list.
   memset(lp->sl_sal_first, 0, sizeof(salfirst_T) * 256);
   for (p = from, s = to; *p != NUL && *s != NUL;) {
-    const int c = mb_cptr2char_adv((const char_u **)&p);
-    const int i = mb_cptr2char_adv((const char_u **)&s);
+    const int c = mb_cptr2char_adv((const char **)&p);
+    const int i = mb_cptr2char_adv((const char **)&s);
     if (c >= 256) {
       // Append the from-to chars at the end of the list with
       // the low byte.
@@ -1597,7 +1616,7 @@ static void set_sal_first(slang_T *lp)
   garray_T *gap = &lp->sl_sal;
 
   sfirst = lp->sl_sal_first;
-  for (int i = 0; i < 256; ++i) {
+  for (int i = 0; i < 256; i++) {
     sfirst[i] = -1;
   }
   smp = (salitem_T *)gap->ga_data;
@@ -1637,13 +1656,13 @@ static void set_sal_first(slang_T *lp)
 
 // Turn a multi-byte string into a wide character string.
 // Return it in allocated memory.
-static int *mb_str2wide(char_u *s)
+static int *mb_str2wide(char *s)
 {
   int i = 0;
 
   int *res = xmalloc(((size_t)mb_charlen(s) + 1) * sizeof(int));
-  for (char_u *p = s; *p != NUL;) {
-    res[i++] = mb_ptr2char_adv((const char_u **)&p);
+  for (char *p = s; *p != NUL;) {
+    res[i++] = mb_ptr2char_adv((const char **)&p);
   }
   res[i] = NUL;
 
@@ -1658,12 +1677,12 @@ static int *mb_str2wide(char_u *s)
 /// @param prefixcnt  when "prefixtree" is true: prefix count
 ///
 /// @return  zero when OK, SP_ value for an error.
-static int spell_read_tree(FILE *fd, char_u **bytsp, long *bytsp_len, idx_T **idxsp,
-                           bool prefixtree, int prefixcnt)
+static int spell_read_tree(FILE *fd, char **bytsp, long *bytsp_len, idx_T **idxsp, bool prefixtree,
+                           int prefixcnt)
   FUNC_ATTR_NONNULL_ARG(1, 2, 4)
 {
   int idx;
-  char_u *bp;
+  char *bp;
   idx_T *ip;
 
   // The tree size was computed when writing the file, so that we can
@@ -1676,23 +1695,25 @@ static int spell_read_tree(FILE *fd, char_u **bytsp, long *bytsp_len, idx_T **id
     // Invalid length, multiply with sizeof(int) would overflow.
     return SP_FORMERROR;
   }
-  if (len > 0) {
-    // Allocate the byte array.
-    bp = xmalloc((size_t)len);
-    *bytsp = bp;
-    if (bytsp_len != NULL) {
-      *bytsp_len = len;
-    }
+  if (len <= 0) {
+    return 0;
+  }
 
-    // Allocate the index array.
-    ip = xcalloc((size_t)len, sizeof(*ip));
-    *idxsp = ip;
+  // Allocate the byte array.
+  bp = xmalloc((size_t)len);
+  *bytsp = bp;
+  if (bytsp_len != NULL) {
+    *bytsp_len = len;
+  }
 
-    // Recursively read the tree and store it in the array.
-    idx = read_tree_node(fd, bp, ip, (int)len, 0, prefixtree, prefixcnt);
-    if (idx < 0) {
-      return idx;
-    }
+  // Allocate the index array.
+  ip = xcalloc((size_t)len, sizeof(*ip));
+  *idxsp = ip;
+
+  // Recursively read the tree and store it in the array.
+  idx = read_tree_node(fd, (char_u *)bp, ip, (int)len, 0, prefixtree, prefixcnt);
+  if (idx < 0) {
+    return idx;
   }
   return 0;
 }
@@ -1732,7 +1753,7 @@ static idx_T read_tree_node(FILE *fd, char_u *byts, idx_T *idxs, int maxidx, idx
   byts[idx++] = (char_u)len;
 
   // Read the byte values, flag/region bytes and shared indexes.
-  for (i = 1; i <= len; ++i) {
+  for (i = 1; i <= len; i++) {
     c = getc(fd);                                       // <byte>
     if (c < 0) {
       return SP_TRUNCERROR;
@@ -1795,7 +1816,7 @@ static idx_T read_tree_node(FILE *fd, char_u *byts, idx_T *idxs, int maxidx, idx
   // Recursively read the children for non-shared siblings.
   // Skip the end-of-word ones (zero byte value) and the shared ones (and
   // remove SHARED_MASK)
-  for (i = 1; i <= len; ++i) {
+  for (i = 1; i <= len; i++) {
     if (byts[startidx + i] != 0) {
       if (idxs[startidx + i] & SHARED_MASK) {
         idxs[startidx + i] &= ~SHARED_MASK;
@@ -1816,19 +1837,19 @@ static idx_T read_tree_node(FILE *fd, char_u *byts, idx_T *idxs, int maxidx, idx
 /// Reload the spell file "fname" if it's loaded.
 ///
 /// @param added_word  invoked through "zg"
-static void spell_reload_one(char_u *fname, bool added_word)
+static void spell_reload_one(char *fname, bool added_word)
 {
   slang_T *slang;
   bool didit = false;
 
   for (slang = first_lang; slang != NULL; slang = slang->sl_next) {
-    if (path_full_compare((char *)fname, (char *)slang->sl_fname, false, true) == kEqualFiles) {
+    if (path_full_compare(fname, slang->sl_fname, false, true) == kEqualFiles) {
       slang_clear(slang);
       if (spell_load_file(fname, NULL, slang, false) == NULL) {
         // reloading failed, clear the language
         slang_clear(slang);
       }
-      redraw_all_later(SOME_VALID);
+      redraw_all_later(UPD_SOME_VALID);
       didit = true;
     }
   }
@@ -1863,7 +1884,7 @@ static long compress_added = 500000;    // word count
 // Sets "sps_flags".
 int spell_check_msm(void)
 {
-  char *p = (char *)p_msm;
+  char *p = p_msm;
   long start = 0;
   long incr = 0;
   long added = 0;
@@ -1924,7 +1945,7 @@ static void spell_clear_flags(wordnode_T *node)
   wordnode_T *np;
 
   for (np = node; np != NULL; np = np->wn_sibling) {
-    np->wn_u1.index = FALSE;
+    np->wn_u1.index = false;
     spell_clear_flags(np->wn_child);
   }
 }
@@ -1940,7 +1961,7 @@ static void spell_print_node(wordnode_T *node, int depth)
     msg((char_u *)line2);
     msg((char_u *)line3);
   } else {
-    node->wn_u1.index = TRUE;
+    node->wn_u1.index = true;
 
     if (node->wn_byte != NUL) {
       if (node->wn_child != NULL) {
@@ -1984,38 +2005,39 @@ static void spell_print_node(wordnode_T *node, int depth)
 
 static void spell_print_tree(wordnode_T *root)
 {
-  if (root != NULL) {
-    // Clear the "wn_u1.index" fields, used to remember what has been
-    // done.
-    spell_clear_flags(root);
-
-    // Recursively print the tree.
-    spell_print_node(root, 0);
+  if (root == NULL) {
+    return;
   }
+
+  // Clear the "wn_u1.index" fields, used to remember what has been done.
+  spell_clear_flags(root);
+
+  // Recursively print the tree.
+  spell_print_node(root, 0);
 }
 
-#endif // SPELL_PRINTTREE
+#endif  // SPELL_PRINTTREE
 
 // Reads the affix file "fname".
 // Returns an afffile_T, NULL for complete failure.
-static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
+static afffile_T *spell_read_aff(spellinfo_T *spin, char *fname)
 {
   FILE *fd;
-  char_u rline[MAXLINELEN];
-  char_u *line;
-  char_u *pc = NULL;
+  char rline[MAXLINELEN];
+  char *line;
+  char *pc = NULL;
 #define MAXITEMCNT  30
-  char_u *(items[MAXITEMCNT]);
+  char *(items[MAXITEMCNT]);
   int itemcnt;
-  char_u *p;
+  char *p;
   int lnum = 0;
   affheader_T *cur_aff = NULL;
   bool did_postpone_prefix = false;
   int aff_todo = 0;
   hashtab_T *tp;
-  char_u *low = NULL;
-  char_u *fol = NULL;
-  char_u *upp = NULL;
+  char *low = NULL;
+  char *fol = NULL;
+  char *upp = NULL;
   int do_rep;
   int do_repsal;
   int do_sal;
@@ -2023,25 +2045,25 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
   bool found_map = false;
   hashitem_T *hi;
   int l;
-  int compminlen = 0;                   // COMPOUNDMIN value
-  int compsylmax = 0;                   // COMPOUNDSYLMAX value
-  int compoptions = 0;                  // COMP_ flags
-  int compmax = 0;                      // COMPOUNDWORDMAX value
-  char_u *compflags = NULL;        // COMPOUNDFLAG and COMPOUNDRULE
+  int compminlen = 0;              // COMPOUNDMIN value
+  int compsylmax = 0;              // COMPOUNDSYLMAX value
+  int compoptions = 0;             // COMP_ flags
+  int compmax = 0;                 // COMPOUNDWORDMAX value
+  char *compflags = NULL;          // COMPOUNDFLAG and COMPOUNDRULE
                                    // concatenated
-  char_u *midword = NULL;          // MIDWORD value
-  char_u *syllable = NULL;         // SYLLABLE value
-  char_u *sofofrom = NULL;         // SOFOFROM value
-  char_u *sofoto = NULL;           // SOFOTO value
+  char *midword = NULL;            // MIDWORD value
+  char *syllable = NULL;           // SYLLABLE value
+  char *sofofrom = NULL;           // SOFOFROM value
+  char *sofoto = NULL;             // SOFOTO value
 
   // Open the file.
-  fd = os_fopen((char *)fname, "r");
+  fd = os_fopen(fname, "r");
   if (fd == NULL) {
     semsg(_(e_notopen), fname);
     return NULL;
   }
 
-  vim_snprintf((char *)IObuff, IOSIZE, _("Reading affix file %s..."), fname);
+  vim_snprintf(IObuff, IOSIZE, _("Reading affix file %s..."), fname);
   spell_message(spin, IObuff);
 
   // Only do REP lines when not done in another .aff file already.
@@ -2091,7 +2113,7 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
     // item.
     itemcnt = 0;
     for (p = line;;) {
-      while (*p != NUL && *p <= ' ') {  // skip white space and CR/NL
+      while (*p != NUL && (uint8_t)(*p) <= ' ') {  // skip white space and CR/NL
         p++;
       }
       if (*p == NUL) {
@@ -2103,11 +2125,11 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
       items[itemcnt++] = p;
       // A few items have arbitrary text argument, don't split them.
       if (itemcnt == 2 && spell_info_item(items[0])) {
-        while (*p >= ' ' || *p == TAB) {  // skip until CR/NL
+        while ((uint8_t)(*p) >= ' ' || *p == TAB) {  // skip until CR/NL
           p++;
         }
       } else {
-        while (*p > ' ') {  // skip until white space or CR/NL
+        while ((uint8_t)(*p) > ' ') {  // skip until white space or CR/NL
           p++;
         }
       }
@@ -2121,21 +2143,20 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
     if (itemcnt > 0) {
       if (is_aff_rule(items, itemcnt, "SET", 2) && aff->af_enc == NULL) {
         // Setup for conversion from "ENC" to 'encoding'.
-        aff->af_enc = enc_canonize(items[1]);
+        aff->af_enc = enc_canonize((char *)items[1]);
         if (!spin->si_ascii
-            && convert_setup(&spin->si_conv, aff->af_enc,
-                             p_enc) == FAIL) {
+            && convert_setup(&spin->si_conv, aff->af_enc, p_enc) == FAIL) {
           smsg(_("Conversion in %s not supported: from %s to %s"),
                fname, aff->af_enc, p_enc);
         }
         spin->si_conv.vc_fail = true;
       } else if (is_aff_rule(items, itemcnt, "FLAG", 2)
                  && aff->af_flagtype == AFT_CHAR) {
-        if (STRCMP(items[1], "long") == 0) {
+        if (strcmp(items[1], "long") == 0) {
           aff->af_flagtype = AFT_LONG;
-        } else if (STRCMP(items[1], "num") == 0) {
+        } else if (strcmp(items[1], "num") == 0) {
           aff->af_flagtype = AFT_NUM;
-        } else if (STRCMP(items[1], "caplong") == 0) {
+        } else if (strcmp(items[1], "caplong") == 0) {
           aff->af_flagtype = AFT_CAPLONG;
         } else {
           smsg(_("Invalid value for FLAG in %s line %d: %s"),
@@ -2157,9 +2178,9 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
         }
       } else if (spell_info_item(items[0]) && itemcnt > 1) {
         p = getroom(spin,
-                    (spin->si_info == NULL ? 0 : STRLEN(spin->si_info))
-                    + STRLEN(items[0])
-                    + STRLEN(items[1]) + 3, false);
+                    (spin->si_info == NULL ? 0 : strlen(spin->si_info))
+                    + strlen(items[0])
+                    + strlen(items[1]) + 3, false);
         if (spin->si_info != NULL) {
           STRCPY(p, spin->si_info);
           STRCAT(p, "\n");
@@ -2168,63 +2189,48 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
         STRCAT(p, " ");
         STRCAT(p, items[1]);
         spin->si_info = p;
-      } else if (is_aff_rule(items, itemcnt, "MIDWORD", 2)
-                 && midword == NULL) {
+      } else if (is_aff_rule(items, itemcnt, "MIDWORD", 2) && midword == NULL) {
         midword = getroom_save(spin, items[1]);
       } else if (is_aff_rule(items, itemcnt, "TRY", 2)) {
         // ignored, we look in the tree for what chars may appear
-      }
-      // TODO: remove "RAR" later
-      else if ((is_aff_rule(items, itemcnt, "RAR", 2)
-                || is_aff_rule(items, itemcnt, "RARE", 2))
-               && aff->af_rare == 0) {
-        aff->af_rare = affitem2flag(aff->af_flagtype, items[1],
-                                    fname, lnum);
-      }
-      // TODO: remove "KEP" later
-      else if ((is_aff_rule(items, itemcnt, "KEP", 2)
-                || is_aff_rule(items, itemcnt, "KEEPCASE", 2))
-               && aff->af_keepcase == 0) {
-        aff->af_keepcase = affitem2flag(aff->af_flagtype, items[1],
-                                        fname, lnum);
+      } else if ((is_aff_rule(items, itemcnt, "RAR", 2)  // TODO(vim): remove "RAR" later
+                  || is_aff_rule(items, itemcnt, "RARE", 2))
+                 && aff->af_rare == 0) {
+        aff->af_rare = affitem2flag(aff->af_flagtype, items[1], fname, lnum);
+      } else if ((is_aff_rule(items, itemcnt, "KEP", 2)  // TODO(vim): remove "KEP" later
+                  || is_aff_rule(items, itemcnt, "KEEPCASE", 2))
+                 && aff->af_keepcase == 0) {
+        aff->af_keepcase = affitem2flag(aff->af_flagtype, items[1], fname, lnum);
       } else if ((is_aff_rule(items, itemcnt, "BAD", 2)
                   || is_aff_rule(items, itemcnt, "FORBIDDENWORD", 2))
                  && aff->af_bad == 0) {
-        aff->af_bad = affitem2flag(aff->af_flagtype, items[1],
-                                   fname, lnum);
+        aff->af_bad = affitem2flag(aff->af_flagtype, items[1], fname, lnum);
       } else if (is_aff_rule(items, itemcnt, "NEEDAFFIX", 2)
                  && aff->af_needaffix == 0) {
-        aff->af_needaffix = affitem2flag(aff->af_flagtype, items[1],
-                                         fname, lnum);
+        aff->af_needaffix = affitem2flag(aff->af_flagtype, items[1], fname, lnum);
       } else if (is_aff_rule(items, itemcnt, "CIRCUMFIX", 2)
                  && aff->af_circumfix == 0) {
-        aff->af_circumfix = affitem2flag(aff->af_flagtype, items[1],
-                                         fname, lnum);
+        aff->af_circumfix = affitem2flag(aff->af_flagtype, items[1], fname, lnum);
       } else if (is_aff_rule(items, itemcnt, "NOSUGGEST", 2)
                  && aff->af_nosuggest == 0) {
-        aff->af_nosuggest = affitem2flag(aff->af_flagtype, items[1],
-                                         fname, lnum);
+        aff->af_nosuggest = affitem2flag(aff->af_flagtype, items[1], fname, lnum);
       } else if ((is_aff_rule(items, itemcnt, "NEEDCOMPOUND", 2)
                   || is_aff_rule(items, itemcnt, "ONLYINCOMPOUND", 2))
                  && aff->af_needcomp == 0) {
-        aff->af_needcomp = affitem2flag(aff->af_flagtype, items[1],
-                                        fname, lnum);
+        aff->af_needcomp = affitem2flag(aff->af_flagtype, items[1], fname, lnum);
       } else if (is_aff_rule(items, itemcnt, "COMPOUNDROOT", 2)
                  && aff->af_comproot == 0) {
-        aff->af_comproot = affitem2flag(aff->af_flagtype, items[1],
-                                        fname, lnum);
+        aff->af_comproot = affitem2flag(aff->af_flagtype, items[1], fname, lnum);
       } else if (is_aff_rule(items, itemcnt, "COMPOUNDFORBIDFLAG", 2)
                  && aff->af_compforbid == 0) {
-        aff->af_compforbid = affitem2flag(aff->af_flagtype, items[1],
-                                          fname, lnum);
+        aff->af_compforbid = affitem2flag(aff->af_flagtype, items[1], fname, lnum);
         if (aff->af_pref.ht_used > 0) {
           smsg(_("Defining COMPOUNDFORBIDFLAG after PFX item may give wrong results in %s line %d"),
                fname, lnum);
         }
       } else if (is_aff_rule(items, itemcnt, "COMPOUNDPERMITFLAG", 2)
                  && aff->af_comppermit == 0) {
-        aff->af_comppermit = affitem2flag(aff->af_flagtype, items[1],
-                                          fname, lnum);
+        aff->af_comppermit = affitem2flag(aff->af_flagtype, items[1], fname, lnum);
         if (aff->af_pref.ht_used > 0) {
           smsg(_("Defining COMPOUNDPERMITFLAG after PFX item may give wrong results in %s line %d"),
                fname, lnum);
@@ -2233,7 +2239,7 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
                  && compflags == NULL) {
         // Turn flag "c" into COMPOUNDRULE compatible string "c+",
         // "Na" into "Na+", "1234" into "1234+".
-        p = getroom(spin, STRLEN(items[1]) + 2, false);
+        p = getroom(spin, strlen(items[1]) + 2, false);
         STRCPY(p, items[1]);
         STRCAT(p, "+");
         compflags = p;
@@ -2249,9 +2255,9 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
         if (compflags != NULL || *skipdigits((char *)items[1]) != NUL) {
           // Concatenate this string to previously defined ones,
           // using a slash to separate them.
-          l = (int)STRLEN(items[1]) + 1;
+          l = (int)strlen(items[1]) + 1;
           if (compflags != NULL) {
-            l += (int)STRLEN(compflags) + 1;
+            l += (int)strlen(compflags) + 1;
           }
           p = getroom(spin, (size_t)l, false);
           if (compflags != NULL) {
@@ -2301,15 +2307,15 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
 
         // Only add the couple if it isn't already there.
         for (i = 0; i < gap->ga_len - 1; i += 2) {
-          if (STRCMP(((char **)(gap->ga_data))[i], items[1]) == 0
-              && STRCMP(((char **)(gap->ga_data))[i + 1], items[2]) == 0) {
+          if (strcmp(((char **)(gap->ga_data))[i], items[1]) == 0
+              && strcmp(((char **)(gap->ga_data))[i + 1], items[2]) == 0) {
             break;
           }
         }
         if (i >= gap->ga_len) {
           ga_grow(gap, 2);
-          ((char **)(gap->ga_data))[gap->ga_len++] = (char *)getroom_save(spin, items[1]);
-          ((char **)(gap->ga_data))[gap->ga_len++] = (char *)getroom_save(spin, items[2]);
+          ((char **)(gap->ga_data))[gap->ga_len++] = getroom_save(spin, items[1]);
+          ((char **)(gap->ga_data))[gap->ga_len++] = getroom_save(spin, items[2]);
         }
       } else if (is_aff_rule(items, itemcnt, "SYLLABLE", 2)
                  && syllable == NULL) {
@@ -2326,12 +2332,12 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
         aff->af_pfxpostpone = true;
       } else if (is_aff_rule(items, itemcnt, "IGNOREEXTRA", 1)) {
         aff->af_ignoreextra = true;
-      } else if ((STRCMP(items[0], "PFX") == 0
-                  || STRCMP(items[0], "SFX") == 0)
+      } else if ((strcmp(items[0], "PFX") == 0
+                  || strcmp(items[0], "SFX") == 0)
                  && aff_todo == 0
                  && itemcnt >= 4) {
         int lasti = 4;
-        char_u key[AH_KEY_LEN];
+        char key[AH_KEY_LEN];
 
         if (*items[0] == 'P') {
           tp = &aff->af_pref;
@@ -2343,7 +2349,7 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
         // times.  The affix files that do this have an undocumented
         // "S" flag on all but the last block, thus we check for that
         // and store it in ah_follows.
-        STRLCPY(key, items[1], AH_KEY_LEN);
+        xstrlcpy(key, items[1], AH_KEY_LEN);
         hi = hash_find(tp, (char *)key);
         if (!HASHITEM_EMPTY(hi)) {
           cur_aff = HI2AH(hi);
@@ -2358,9 +2364,8 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
         } else {
           // New affix letter.
           cur_aff = getroom(spin, sizeof(*cur_aff), true);
-          cur_aff->ah_flag = affitem2flag(aff->af_flagtype, items[1],
-                                          fname, lnum);
-          if (cur_aff->ah_flag == 0 || STRLEN(items[1]) >= AH_KEY_LEN) {
+          cur_aff->ah_flag = affitem2flag(aff->af_flagtype, items[1], fname, lnum);
+          if (cur_aff->ah_flag == 0 || strlen(items[1]) >= AH_KEY_LEN) {
             break;
           }
           if (cur_aff->ah_flag == aff->af_bad
@@ -2384,7 +2389,7 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
 
         // Check for the "S" flag, which apparently means that another
         // block with the same affix name is following.
-        if (itemcnt > lasti && STRCMP(items[lasti], "S") == 0) {
+        if (itemcnt > lasti && strcmp(items[lasti], "S") == 0) {
           lasti++;
           cur_aff->ah_follows = true;
         } else {
@@ -2400,7 +2405,7 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
           smsg(_(e_afftrailing), fname, lnum, items[lasti]);
         }
 
-        if (STRCMP(items[2], "Y") != 0 && STRCMP(items[2], "N") != 0) {
+        if (strcmp(items[2], "Y") != 0 && strcmp(items[2], "N") != 0) {
           smsg(_("Expected Y or N in %s line %d: %s"),
                fname, lnum, items[2]);
         }
@@ -2423,10 +2428,10 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
         }
 
         aff_todo = atoi((char *)items[3]);
-      } else if ((STRCMP(items[0], "PFX") == 0
-                  || STRCMP(items[0], "SFX") == 0)
+      } else if ((strcmp(items[0], "PFX") == 0
+                  || strcmp(items[0], "SFX") == 0)
                  && aff_todo > 0
-                 && STRCMP(cur_aff->ah_key, items[1]) == 0
+                 && strcmp(cur_aff->ah_key, items[1]) == 0
                  && itemcnt >= 5) {
         affentry_T *aff_entry;
         bool upper = false;
@@ -2436,7 +2441,7 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
         // mean mistakes go unnoticed.  Require a comment-starter.
         // Hunspell uses a "-" item.
         if (itemcnt > lasti && *items[lasti] != '#'
-            && (STRCMP(items[lasti], "-") != 0
+            && (strcmp(items[lasti], "-") != 0
                 || itemcnt != lasti + 1)) {
           smsg(_(e_afftrailing), fname, lnum, items[lasti]);
         }
@@ -2445,14 +2450,14 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
         aff_todo--;
         aff_entry = getroom(spin, sizeof(*aff_entry), true);
 
-        if (STRCMP(items[2], "0") != 0) {
+        if (strcmp(items[2], "0") != 0) {
           aff_entry->ae_chop = getroom_save(spin, items[2]);
         }
-        if (STRCMP(items[3], "0") != 0) {
+        if (strcmp(items[3], "0") != 0) {
           aff_entry->ae_add = getroom_save(spin, items[3]);
 
           // Recognize flags on the affix: abcd/XYZ
-          aff_entry->ae_flags = (char_u *)vim_strchr((char *)aff_entry->ae_add, '/');
+          aff_entry->ae_flags = vim_strchr(aff_entry->ae_add, '/');
           if (aff_entry->ae_flags != NULL) {
             *aff_entry->ae_flags++ = NUL;
             aff_process_flags(aff, aff_entry);
@@ -2466,16 +2471,16 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
           aff_entry->ae_next = cur_aff->ah_first;
           cur_aff->ah_first = aff_entry;
 
-          if (STRCMP(items[4], ".") != 0) {
-            char_u buf[MAXLINELEN];
+          if (strcmp(items[4], ".") != 0) {
+            char buf[MAXLINELEN];
 
             aff_entry->ae_cond = getroom_save(spin, items[4]);
             if (*items[0] == 'P') {
-              sprintf((char *)buf, "^%s", items[4]);
+              sprintf(buf, "^%s", items[4]);  // NOLINT(runtime/printf)
             } else {
-              sprintf((char *)buf, "%s$", items[4]);
+              sprintf(buf, "%s$", items[4]);  // NOLINT(runtime/printf)
             }
-            aff_entry->ae_prog = vim_regcomp((char *)buf, RE_MAGIC + RE_STRING + RE_STRICT);
+            aff_entry->ae_prog = vim_regcomp(buf, RE_MAGIC + RE_STRING + RE_STRICT);
             if (aff_entry->ae_prog == NULL) {
               smsg(_("Broken condition in %s line %d: %s"),
                    fname, lnum, items[4]);
@@ -2495,19 +2500,18 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
             // be empty or start with the same letter.
             if (aff_entry->ae_chop != NULL
                 && aff_entry->ae_add != NULL
-                && aff_entry->ae_chop[utfc_ptr2len((char *)aff_entry->ae_chop)] ==
+                && aff_entry->ae_chop[utfc_ptr2len(aff_entry->ae_chop)] ==
                 NUL) {
               int c, c_up;
 
-              c = utf_ptr2char((char *)aff_entry->ae_chop);
+              c = utf_ptr2char(aff_entry->ae_chop);
               c_up = SPELL_TOUPPER(c);
               if (c_up != c
                   && (aff_entry->ae_cond == NULL
-                      || utf_ptr2char((char *)aff_entry->ae_cond) == c)) {
-                p = aff_entry->ae_add
-                    + STRLEN(aff_entry->ae_add);
+                      || utf_ptr2char(aff_entry->ae_cond) == c)) {
+                p = aff_entry->ae_add + strlen(aff_entry->ae_add);
                 MB_PTR_BACK(aff_entry->ae_add, p);
-                if (utf_ptr2char((char *)p) == c_up) {
+                if (utf_ptr2char(p) == c_up) {
                   upper = true;
                   aff_entry->ae_chop = NULL;
                   *p = NUL;
@@ -2516,14 +2520,13 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
                   // actual word, thus must check for the
                   // upper-case letter.
                   if (aff_entry->ae_cond != NULL) {
-                    char_u buf[MAXLINELEN];
+                    char buf[MAXLINELEN];
                     onecap_copy(items[4], buf, true);
                     aff_entry->ae_cond = getroom_save(spin, buf);
                     if (aff_entry->ae_cond != NULL) {
-                      sprintf((char *)buf, "^%s",
-                              aff_entry->ae_cond);
+                      sprintf(buf, "^%s", aff_entry->ae_cond);  // NOLINT(runtime/printf)
                       vim_regfree(aff_entry->ae_prog);
-                      aff_entry->ae_prog = vim_regcomp((char *)buf, RE_MAGIC + RE_STRING);
+                      aff_entry->ae_prog = vim_regcomp(buf, RE_MAGIC + RE_STRING);
                     }
                   }
                 }
@@ -2536,9 +2539,8 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
               int n;
 
               // Find a previously used condition.
-              for (idx = spin->si_prefcond.ga_len - 1; idx >= 0;
-                   --idx) {
-                p = ((char_u **)spin->si_prefcond.ga_data)[idx];
+              for (idx = spin->si_prefcond.ga_len - 1; idx >= 0; idx--) {
+                p = ((char **)spin->si_prefcond.ga_data)[idx];
                 if (str_equal(p, aff_entry->ae_cond)) {
                   break;
                 }
@@ -2548,12 +2550,12 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
                 idx = spin->si_prefcond.ga_len;
                 pp = GA_APPEND_VIA_PTR(char_u *, &spin->si_prefcond);
                 *pp = (aff_entry->ae_cond == NULL) ?
-                      NULL : getroom_save(spin, aff_entry->ae_cond);
+                      NULL : (char_u *)getroom_save(spin, aff_entry->ae_cond);
               }
 
               // Add the prefix to the prefix tree.
               if (aff_entry->ae_add == NULL) {
-                p = (char_u *)"";
+                p = "";
               } else {
                 p = aff_entry->ae_add;
               }
@@ -2573,33 +2575,33 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
               if (aff_entry->ae_compforbid) {
                 n |= WFP_COMPFORBID;
               }
-              tree_add_word(spin, p, spin->si_prefroot, n,
+              tree_add_word(spin, (char_u *)p, spin->si_prefroot, n,
                             idx, cur_aff->ah_newID);
               did_postpone_prefix = true;
             }
 
             // Didn't actually use ah_newID, backup si_newprefID.
             if (aff_todo == 0 && !did_postpone_prefix) {
-              --spin->si_newprefID;
+              spin->si_newprefID--;
               cur_aff->ah_newID = 0;
             }
           }
         }
       } else if (is_aff_rule(items, itemcnt, "FOL", 2) && fol == NULL) {
-        fol = vim_strsave(items[1]);
+        fol = xstrdup(items[1]);
       } else if (is_aff_rule(items, itemcnt, "LOW", 2) && low == NULL) {
-        low = vim_strsave(items[1]);
+        low = xstrdup(items[1]);
       } else if (is_aff_rule(items, itemcnt, "UPP", 2) && upp == NULL) {
-        upp = vim_strsave(items[1]);
+        upp = xstrdup(items[1]);
       } else if (is_aff_rule(items, itemcnt, "REP", 2)
                  || is_aff_rule(items, itemcnt, "REPSAL", 2)) {
         // Ignore REP/REPSAL count
-        if (!isdigit(*items[1])) {
+        if (!isdigit((uint8_t)(*items[1]))) {
           smsg(_("Expected REP(SAL) count in %s line %d"),
                fname, lnum);
         }
-      } else if ((STRCMP(items[0], "REP") == 0
-                  || STRCMP(items[0], "REPSAL") == 0)
+      } else if ((strcmp(items[0], "REP") == 0
+                  || strcmp(items[0], "REPSAL") == 0)
                  && itemcnt >= 3) {
         // REP/REPSAL item
         // Myspell ignores extra arguments, we require it starts with
@@ -2621,15 +2623,15 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
             }
           }
           add_fromto(spin, items[0][3] == 'S'
-              ? &spin->si_repsal
-              : &spin->si_rep, items[1], items[2]);
+                     ? &spin->si_repsal
+                     : &spin->si_rep, items[1], items[2]);
         }
       } else if (is_aff_rule(items, itemcnt, "MAP", 2)) {
         // MAP item or count
         if (!found_map) {
           // First line contains the count.
           found_map = true;
-          if (!isdigit(*items[1])) {
+          if (!isdigit((uint8_t)(*items[1]))) {
             smsg(_("Expected MAP count in %s line %d"),
                  fname, lnum);
           }
@@ -2638,11 +2640,11 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
 
           // Check that every character appears only once.
           for (p = items[1]; *p != NUL;) {
-            c = mb_ptr2char_adv((const char_u **)&p);
+            c = mb_ptr2char_adv((const char **)&p);
             if ((!GA_EMPTY(&spin->si_map)
                  && vim_strchr(spin->si_map.ga_data, c)
                  != NULL)
-                || vim_strchr((char *)p, c) != NULL) {
+                || vim_strchr(p, c) != NULL) {
               smsg(_("Duplicate character in MAP in %s line %d"),
                    fname, lnum);
             }
@@ -2659,17 +2661,17 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
         if (do_sal) {
           // SAL item (sounds-a-like)
           // Either one of the known keys or a from-to pair.
-          if (STRCMP(items[1], "followup") == 0) {
+          if (strcmp(items[1], "followup") == 0) {
             spin->si_followup = sal_to_bool(items[2]);
-          } else if (STRCMP(items[1], "collapse_result") == 0) {
+          } else if (strcmp(items[1], "collapse_result") == 0) {
             spin->si_collapse = sal_to_bool(items[2]);
-          } else if (STRCMP(items[1], "remove_accents") == 0) {
+          } else if (strcmp(items[1], "remove_accents") == 0) {
             spin->si_rem_accents = sal_to_bool(items[2]);
           } else {
             // when "to" is "_" it means empty
             add_fromto(spin, &spin->si_sal, items[1],
-                       STRCMP(items[2], "_") == 0 ? (char_u *)""
-                                                  : items[2]);
+                       strcmp(items[2], "_") == 0 ? ""
+                       : items[2]);
           }
         }
       } else if (is_aff_rule(items, itemcnt, "SOFOFROM", 2)
@@ -2678,12 +2680,12 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
       } else if (is_aff_rule(items, itemcnt, "SOFOTO", 2)
                  && sofoto == NULL) {
         sofoto = getroom_save(spin, items[1]);
-      } else if (STRCMP(items[0], "COMMON") == 0) {
+      } else if (strcmp(items[0], "COMMON") == 0) {
         int i;
 
         for (i = 1; i < itemcnt; i++) {
           if (HASHITEM_EMPTY(hash_find(&spin->si_commonwords, (char *)items[i]))) {
-            p = vim_strsave(items[i]);
+            p = xstrdup(items[i]);
             hash_add(&spin->si_commonwords, p);
           }
         }
@@ -2775,11 +2777,11 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
   return aff;
 }
 
-// Returns true when items[0] equals "rulename", there are "mincount" items or
-// a comment is following after item "mincount".
-static bool is_aff_rule(char_u **items, int itemcnt, char *rulename, int mincount)
+/// @return  true when items[0] equals "rulename", there are "mincount" items or
+///          a comment is following after item "mincount".
+static bool is_aff_rule(char **items, int itemcnt, char *rulename, int mincount)
 {
-  return STRCMP(items[0], rulename) == 0
+  return strcmp(items[0], rulename) == 0
          && (itemcnt == mincount
              || (itemcnt > mincount && items[mincount][0] == '#'));
 }
@@ -2788,18 +2790,18 @@ static bool is_aff_rule(char_u **items, int itemcnt, char *rulename, int mincoun
 // ae_flags to ae_comppermit and ae_compforbid.
 static void aff_process_flags(afffile_T *affile, affentry_T *entry)
 {
-  char_u *p;
+  char *p;
   char_u *prevp;
   unsigned flag;
 
   if (entry->ae_flags != NULL
       && (affile->af_compforbid != 0 || affile->af_comppermit != 0)) {
     for (p = entry->ae_flags; *p != NUL;) {
-      prevp = p;
+      prevp = (char_u *)p;
       flag = get_affitem(affile->af_flagtype, &p);
       if (flag == affile->af_comppermit || flag == affile->af_compforbid) {
-        STRMOVE(prevp, p);
-        p = prevp;
+        STRMOVE(prevp, (char *)p);
+        p = (char *)prevp;
         if (flag == affile->af_comppermit) {
           entry->ae_comppermit = true;
         } else {
@@ -2816,23 +2818,23 @@ static void aff_process_flags(afffile_T *affile, affentry_T *entry)
   }
 }
 
-// Returns true if "s" is the name of an info item in the affix file.
-static bool spell_info_item(char_u *s)
+/// @return  true if "s" is the name of an info item in the affix file.
+static bool spell_info_item(char *s)
 {
-  return STRCMP(s, "NAME") == 0
-         || STRCMP(s, "HOME") == 0
-         || STRCMP(s, "VERSION") == 0
-         || STRCMP(s, "AUTHOR") == 0
-         || STRCMP(s, "EMAIL") == 0
-         || STRCMP(s, "COPYRIGHT") == 0;
+  return strcmp(s, "NAME") == 0
+         || strcmp(s, "HOME") == 0
+         || strcmp(s, "VERSION") == 0
+         || strcmp(s, "AUTHOR") == 0
+         || strcmp(s, "EMAIL") == 0
+         || strcmp(s, "COPYRIGHT") == 0;
 }
 
 // Turn an affix flag name into a number, according to the FLAG type.
 // returns zero for failure.
-static unsigned affitem2flag(int flagtype, char_u *item, char_u *fname, int lnum)
+static unsigned affitem2flag(int flagtype, char *item, char *fname, int lnum)
 {
   unsigned res;
-  char_u *p = item;
+  char *p = item;
 
   res = get_affitem(flagtype, &p);
   if (res == 0) {
@@ -2855,54 +2857,54 @@ static unsigned affitem2flag(int flagtype, char_u *item, char_u *fname, int lnum
 // Get one affix name from "*pp" and advance the pointer.
 // Returns ZERO_FLAG for "0".
 // Returns zero for an error, still advances the pointer then.
-static unsigned get_affitem(int flagtype, char_u **pp)
+static unsigned get_affitem(int flagtype, char **pp)
 {
   int res;
 
   if (flagtype == AFT_NUM) {
     if (!ascii_isdigit(**pp)) {
-      ++*pp;            // always advance, avoid getting stuck
+      (*pp)++;            // always advance, avoid getting stuck
       return 0;
     }
-    res = getdigits_int((char **)pp, true, 0);
+    res = getdigits_int(pp, true, 0);
     if (res == 0) {
       res = ZERO_FLAG;
     }
   } else {
-    res = mb_ptr2char_adv((const char_u **)pp);
+    res = mb_ptr2char_adv((const char **)pp);
     if (flagtype == AFT_LONG || (flagtype == AFT_CAPLONG
                                  && res >= 'A' && res <= 'Z')) {
       if (**pp == NUL) {
         return 0;
       }
-      res = mb_ptr2char_adv((const char_u **)pp) + (res << 16);
+      res = mb_ptr2char_adv((const char **)pp) + (res << 16);
     }
   }
   return (unsigned)res;
 }
 
-// Process the "compflags" string used in an affix file and append it to
-// spin->si_compflags.
-// The processing involves changing the affix names to ID numbers, so that
-// they fit in one byte.
-static void process_compflags(spellinfo_T *spin, afffile_T *aff, char_u *compflags)
+/// Process the "compflags" string used in an affix file and append it to
+/// spin->si_compflags.
+/// The processing involves changing the affix names to ID numbers, so that
+/// they fit in one byte.
+static void process_compflags(spellinfo_T *spin, afffile_T *aff, char *compflags)
 {
-  char_u *p;
-  char_u *prevp;
+  char *p;
+  char *prevp;
   unsigned flag;
   compitem_T *ci;
   int id;
   int len;
   char_u *tp;
-  char_u key[AH_KEY_LEN];
+  char key[AH_KEY_LEN];
   hashitem_T *hi;
 
   // Make room for the old and the new compflags, concatenated with a / in
   // between.  Processing it makes it shorter, but we don't know by how
   // much, thus allocate the maximum.
-  len = (int)STRLEN(compflags) + 1;
+  len = (int)strlen(compflags) + 1;
   if (spin->si_compflags != NULL) {
-    len += (int)STRLEN(spin->si_compflags) + 1;
+    len += (int)strlen(spin->si_compflags) + 1;
   }
   p = getroom(spin, (size_t)len, false);
   if (spin->si_compflags != NULL) {
@@ -2910,12 +2912,12 @@ static void process_compflags(spellinfo_T *spin, afffile_T *aff, char_u *compfla
     STRCAT(p, "/");
   }
   spin->si_compflags = p;
-  tp = p + STRLEN(p);
+  tp = (char_u *)p + strlen(p);
 
   for (p = compflags; *p != NUL;) {
-    if (vim_strchr("/?*+[]", *p) != NULL) {
+    if (vim_strchr("/?*+[]", (uint8_t)(*p)) != NULL) {
       // Copy non-flag characters directly.
-      *tp++ = *p++;
+      *tp++ = (char_u)(*p++);
     } else {
       // First get the flag number, also checks validity.
       prevp = p;
@@ -2923,7 +2925,7 @@ static void process_compflags(spellinfo_T *spin, afffile_T *aff, char_u *compfla
       if (flag != 0) {
         // Find the flag in the hashtable.  If it was used before, use
         // the existing ID.  Otherwise add a new entry.
-        STRLCPY(key, prevp, p - prevp + 1);
+        xstrlcpy(key, prevp, (size_t)(p - prevp) + 1);
         hi = hash_find(&aff->af_comp, (char *)key);
         if (!HASHITEM_EMPTY(hi)) {
           id = HI2CI(hi)->ci_newID;
@@ -2938,7 +2940,7 @@ static void process_compflags(spellinfo_T *spin, afffile_T *aff, char_u *compfla
             id = spin->si_newcompID--;
           } while (vim_strchr("/?*+[]\\-^", id) != NULL);
           ci->ci_newID = id;
-          hash_add(&aff->af_comp, ci->ci_key);
+          hash_add(&aff->af_comp, (char *)ci->ci_key);
         }
         *tp++ = (char_u)id;
       }
@@ -2964,22 +2966,22 @@ static void check_renumber(spellinfo_T *spin)
 }
 
 // Returns true if flag "flag" appears in affix list "afflist".
-static bool flag_in_afflist(int flagtype, char_u *afflist, unsigned flag)
+static bool flag_in_afflist(int flagtype, char *afflist, unsigned flag)
 {
   char *p;
   unsigned n;
 
   switch (flagtype) {
   case AFT_CHAR:
-    return vim_strchr((char *)afflist, (int)flag) != NULL;
+    return vim_strchr(afflist, (int)flag) != NULL;
 
   case AFT_CAPLONG:
   case AFT_LONG:
-    for (p = (char *)afflist; *p != NUL;) {
-      n = (unsigned)mb_ptr2char_adv((const char_u **)&p);
+    for (p = afflist; *p != NUL;) {
+      n = (unsigned)mb_ptr2char_adv((const char **)&p);
       if ((flagtype == AFT_LONG || (n >= 'A' && n <= 'Z'))
           && *p != NUL) {
-        n = (unsigned)mb_ptr2char_adv((const char_u **)&p) + (n << 16);
+        n = (unsigned)mb_ptr2char_adv((const char **)&p) + (n << 16);
       }
       if (n == flag) {
         return true;
@@ -2988,7 +2990,7 @@ static bool flag_in_afflist(int flagtype, char_u *afflist, unsigned flag)
     break;
 
   case AFT_NUM:
-    for (p = (char *)afflist; *p != NUL;) {
+    for (p = afflist; *p != NUL;) {
       int digits = getdigits_int(&p, true, 0);
       assert(digits >= 0);
       n = (unsigned int)digits;
@@ -3016,42 +3018,42 @@ static void aff_check_number(int spinval, int affval, char *name)
   }
 }
 
-// Give a warning when "spinval" and "affval" strings are set and not the same.
-static void aff_check_string(char_u *spinval, char_u *affval, char *name)
+/// Give a warning when "spinval" and "affval" strings are set and not the same.
+static void aff_check_string(char *spinval, char *affval, char *name)
 {
-  if (spinval != NULL && STRCMP(spinval, affval) != 0) {
+  if (spinval != NULL && strcmp(spinval, affval) != 0) {
     smsg(_("%s value differs from what is used in another .aff file"),
          name);
   }
 }
 
-// Returns true if strings "s1" and "s2" are equal.  Also consider both being
-// NULL as equal.
-static bool str_equal(char_u *s1, char_u *s2)
+/// @return  true if strings "s1" and "s2" are equal.  Also consider both being
+///          NULL as equal.
+static bool str_equal(char *s1, char *s2)
 {
   if (s1 == NULL || s2 == NULL) {
     return s1 == s2;
   }
-  return STRCMP(s1, s2) == 0;
+  return strcmp(s1, s2) == 0;
 }
 
-// Add a from-to item to "gap".  Used for REP and SAL items.
-// They are stored case-folded.
-static void add_fromto(spellinfo_T *spin, garray_T *gap, char_u *from, char_u *to)
+/// Add a from-to item to "gap".  Used for REP and SAL items.
+/// They are stored case-folded.
+static void add_fromto(spellinfo_T *spin, garray_T *gap, char *from, char *to)
 {
-  char_u word[MAXWLEN];
+  char word[MAXWLEN];
 
   fromto_T *ftp = GA_APPEND_VIA_PTR(fromto_T, gap);
-  (void)spell_casefold(curwin, from, (int)STRLEN(from), word, MAXWLEN);
+  (void)spell_casefold(curwin, from, (int)strlen(from), word, MAXWLEN);
   ftp->ft_from = getroom_save(spin, word);
-  (void)spell_casefold(curwin, to, (int)STRLEN(to), word, MAXWLEN);
+  (void)spell_casefold(curwin, to, (int)strlen(to), word, MAXWLEN);
   ftp->ft_to = getroom_save(spin, word);
 }
 
-// Converts a boolean argument in a SAL line to true or false;
-static bool sal_to_bool(char_u *s)
+/// Converts a boolean argument in a SAL line to true or false;
+static bool sal_to_bool(char *s)
 {
-  return STRCMP(s, "1") == 0 || STRCMP(s, "true") == 0;
+  return strcmp(s, "1") == 0 || strcmp(s, "true") == 0;
 }
 
 // Free the structure filled by spell_read_aff().
@@ -3068,7 +3070,7 @@ static void spell_free_aff(afffile_T *aff)
   // All this trouble to free the "ae_prog" items...
   for (ht = &aff->af_pref;; ht = &aff->af_suff) {
     todo = (int)ht->ht_used;
-    for (hi = ht->ht_array; todo > 0; ++hi) {
+    for (hi = ht->ht_array; todo > 0; hi++) {
       if (!HASHITEM_EMPTY(hi)) {
         todo--;
         ah = HI2AH(hi);
@@ -3089,16 +3091,16 @@ static void spell_free_aff(afffile_T *aff)
 
 // Read dictionary file "fname".
 // Returns OK or FAIL;
-static int spell_read_dic(spellinfo_T *spin, char_u *fname, afffile_T *affile)
+static int spell_read_dic(spellinfo_T *spin, char *fname, afffile_T *affile)
 {
   hashtab_T ht;
-  char_u line[MAXLINELEN];
+  char line[MAXLINELEN];
   char_u *p;
   char_u *afflist;
   char_u store_afflist[MAXWLEN];
   int pfxlen;
   bool need_affix;
-  char_u *dw;
+  char *dw;
   char_u *pc;
   char_u *w;
   int l;
@@ -3114,7 +3116,7 @@ static int spell_read_dic(spellinfo_T *spin, char_u *fname, afffile_T *affile)
   Timestamp last_msg_time = 0;
 
   // Open the file.
-  fd = os_fopen((char *)fname, "r");
+  fd = os_fopen(fname, "r");
   if (fd == NULL) {
     semsg(_(e_notopen), fname);
     return FAIL;
@@ -3123,7 +3125,7 @@ static int spell_read_dic(spellinfo_T *spin, char_u *fname, afffile_T *affile)
   // The hashtable is only used to detect duplicated words.
   hash_init(&ht);
 
-  vim_snprintf((char *)IObuff, IOSIZE,
+  vim_snprintf(IObuff, IOSIZE,
                _("Reading dictionary file %s..."), fname);
   spell_message(spin, IObuff);
 
@@ -3131,14 +3133,14 @@ 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] == '/') {
@@ -3146,7 +3148,7 @@ static int spell_read_dic(spellinfo_T *spin, char_u *fname, afffile_T *affile)
     }
     // Remove CR, LF and white space from the end.  White space halfway through
     // the word is kept to allow multi-word terms like "et al.".
-    l = (int)STRLEN(line);
+    l = (int)strlen(line);
     while (l > 0 && line[l - 1] <= ' ') {
       l--;
     }
@@ -3157,7 +3159,7 @@ static int spell_read_dic(spellinfo_T *spin, char_u *fname, afffile_T *affile)
 
     // Convert from "SET" to 'encoding' when needed.
     if (spin->si_conv.vc_type != CONV_NONE) {
-      pc = string_convert(&spin->si_conv, line, NULL);
+      pc = (char_u *)string_convert(&spin->si_conv, (char *)line, NULL);
       if (pc == NULL) {
         smsg(_("Conversion failure for word in %s line %d: %s"),
              fname, lnum, line);
@@ -3166,7 +3168,7 @@ static int spell_read_dic(spellinfo_T *spin, char_u *fname, afffile_T *affile)
       w = pc;
     } else {
       pc = NULL;
-      w = line;
+      w = (char_u *)line;
     }
 
     // Truncate the word at the "/", set "afflist" to what follows.
@@ -3174,7 +3176,7 @@ static int spell_read_dic(spellinfo_T *spin, char_u *fname, afffile_T *affile)
     afflist = NULL;
     for (p = w; *p != NUL; MB_PTR_ADV(p)) {
       if (*p == '\\' && (p[1] == '\\' || p[1] == '/')) {
-        STRMOVE(p, p + 1);
+        STRMOVE(p, (char *)p + 1);
       } else if (*p == '/') {
         *p = NUL;
         afflist = p + 1;
@@ -3183,7 +3185,7 @@ static int spell_read_dic(spellinfo_T *spin, char_u *fname, afffile_T *affile)
     }
 
     // Skip non-ASCII words when "spin->si_ascii" is true.
-    if (spin->si_ascii && has_non_ascii(w)) {
+    if (spin->si_ascii && has_non_ascii((char *)w)) {
       non_ascii++;
       xfree(pc);
       continue;
@@ -3199,7 +3201,7 @@ static int spell_read_dic(spellinfo_T *spin, char_u *fname, afffile_T *affile)
                      _("line %6d, word %6ld - %s"),
                      lnum, spin->si_foldwcount + spin->si_keepwcount, w);
         msg_start();
-        msg_outtrans_long_attr(message, 0);
+        msg_outtrans_long_attr((char *)message, 0);
         msg_clr_eos();
         msg_didout = false;
         msg_col = 0;
@@ -3208,7 +3210,7 @@ static int spell_read_dic(spellinfo_T *spin, char_u *fname, afffile_T *affile)
     }
 
     // Store the word in the hashtable to be able to find duplicates.
-    dw = getroom_save(spin, w);
+    dw = getroom_save(spin, (char *)w);
     if (dw == NULL) {
       retval = FAIL;
       xfree(pc);
@@ -3216,7 +3218,7 @@ static int spell_read_dic(spellinfo_T *spin, char_u *fname, afffile_T *affile)
     }
 
     hash = hash_hash(dw);
-    hi = hash_lookup(&ht, (const char *)dw, STRLEN(dw), hash);
+    hi = hash_lookup(&ht, (const char *)dw, strlen(dw), hash);
     if (!HASHITEM_EMPTY(hi)) {
       if (p_verbose > 0) {
         smsg(_("Duplicate word in %s line %d: %s"),
@@ -3236,45 +3238,45 @@ static int spell_read_dic(spellinfo_T *spin, char_u *fname, afffile_T *affile)
     need_affix = false;
     if (afflist != NULL) {
       // Extract flags from the affix list.
-      flags |= get_affix_flags(affile, afflist);
+      flags |= get_affix_flags(affile, (char *)afflist);
 
       if (affile->af_needaffix != 0
-          && flag_in_afflist(affile->af_flagtype, afflist,
+          && flag_in_afflist(affile->af_flagtype, (char *)afflist,
                              affile->af_needaffix)) {
         need_affix = true;
       }
 
       if (affile->af_pfxpostpone) {
         // Need to store the list of prefix IDs with the word.
-        pfxlen = get_pfxlist(affile, afflist, store_afflist);
+        pfxlen = get_pfxlist(affile, (char *)afflist, store_afflist);
       }
 
       if (spin->si_compflags != NULL) {
         // Need to store the list of compound flags with the word.
         // Concatenate them to the list of prefix IDs.
-        get_compflags(affile, afflist, store_afflist + pfxlen);
+        get_compflags(affile, (char *)afflist, store_afflist + pfxlen);
       }
     }
 
     // Add the word to the word tree(s).
     if (store_word(spin, dw, flags, spin->si_region,
-                   store_afflist, need_affix) == FAIL) {
+                   (char *)store_afflist, need_affix) == FAIL) {
       retval = FAIL;
     }
 
     if (afflist != NULL) {
       // Find all matching suffixes and add the resulting words.
       // Additionally do matching prefixes that combine.
-      if (store_aff_word(spin, dw, afflist, affile,
+      if (store_aff_word(spin, dw, (char *)afflist, affile,
                          &affile->af_suff, &affile->af_pref,
-                         CONDIT_SUF, flags, store_afflist, pfxlen) == FAIL) {
+                         CONDIT_SUF, flags, (char *)store_afflist, pfxlen) == FAIL) {
         retval = FAIL;
       }
 
       // Find all matching prefixes and add the resulting words.
-      if (store_aff_word(spin, dw, afflist, affile,
+      if (store_aff_word(spin, dw, (char *)afflist, affile,
                          &affile->af_pref, NULL,
-                         CONDIT_SUF, flags, store_afflist, pfxlen) == FAIL) {
+                         CONDIT_SUF, flags, (char *)store_afflist, pfxlen) == FAIL) {
         retval = FAIL;
       }
     }
@@ -3297,7 +3299,7 @@ static int spell_read_dic(spellinfo_T *spin, char_u *fname, afffile_T *affile)
 
 // Check for affix flags in "afflist" that are turned into word flags.
 // Return WF_ flags.
-static int get_affix_flags(afffile_T *affile, char_u *afflist)
+static int get_affix_flags(afffile_T *affile, char *afflist)
 {
   int flags = 0;
 
@@ -3336,13 +3338,13 @@ static int get_affix_flags(afffile_T *affile, char_u *afflist)
 // Used for PFXPOSTPONE.
 // Put the resulting flags in "store_afflist[MAXWLEN]" with a terminating NUL
 // and return the number of affixes.
-static int get_pfxlist(afffile_T *affile, char_u *afflist, char_u *store_afflist)
+static int get_pfxlist(afffile_T *affile, char *afflist, char_u *store_afflist)
 {
-  char_u *p;
-  char_u *prevp;
+  char *p;
+  char *prevp;
   int cnt = 0;
   int id;
-  char_u key[AH_KEY_LEN];
+  char key[AH_KEY_LEN];
   hashitem_T *hi;
 
   for (p = afflist; *p != NUL;) {
@@ -3350,7 +3352,7 @@ static int get_pfxlist(afffile_T *affile, char_u *afflist, char_u *store_afflist
     if (get_affitem(affile->af_flagtype, &p) != 0) {
       // A flag is a postponed prefix flag if it appears in "af_pref"
       // and its ID is not zero.
-      STRLCPY(key, prevp, p - prevp + 1);
+      xstrlcpy(key, prevp, (size_t)(p - prevp) + 1);
       hi = hash_find(&affile->af_pref, (char *)key);
       if (!HASHITEM_EMPTY(hi)) {
         id = HI2AH(hi)->ah_newID;
@@ -3371,19 +3373,19 @@ static int get_pfxlist(afffile_T *affile, char_u *afflist, char_u *store_afflist
 // Get the list of compound IDs from the affix list "afflist" that are used
 // for compound words.
 // Puts the flags in "store_afflist[]".
-static void get_compflags(afffile_T *affile, char_u *afflist, char_u *store_afflist)
+static void get_compflags(afffile_T *affile, char *afflist, char_u *store_afflist)
 {
-  char_u *p;
-  char_u *prevp;
+  char *p;
+  char *prevp;
   int cnt = 0;
-  char_u key[AH_KEY_LEN];
+  char key[AH_KEY_LEN];
   hashitem_T *hi;
 
   for (p = afflist; *p != NUL;) {
     prevp = p;
     if (get_affitem(affile->af_flagtype, &p) != 0) {
       // A flag is a compound flag if it appears in "af_comp".
-      STRLCPY(key, prevp, p - prevp + 1);
+      xstrlcpy(key, prevp, (size_t)(p - prevp) + 1);
       hi = hash_find(&affile->af_comp, (char *)key);
       if (!HASHITEM_EMPTY(hi)) {
         store_afflist[cnt++] = (char_u)HI2CI(hi)->ci_newID;
@@ -3412,29 +3414,29 @@ static void get_compflags(afffile_T *affile, char_u *afflist, char_u *store_affl
 /// @param pfxlen  nr of flags in "pfxlist" for prefixes, rest is compound flags
 ///
 /// @return  FAIL when out of memory.
-static int store_aff_word(spellinfo_T *spin, char_u *word, char_u *afflist, afffile_T *affile,
-                          hashtab_T *ht, hashtab_T *xht, int condit, int flags, char_u *pfxlist,
+static int store_aff_word(spellinfo_T *spin, char *word, char *afflist, afffile_T *affile,
+                          hashtab_T *ht, hashtab_T *xht, int condit, int flags, char *pfxlist,
                           int pfxlen)
 {
   int todo;
   hashitem_T *hi;
   affheader_T *ah;
   affentry_T *ae;
-  char_u newword[MAXWLEN];
+  char newword[MAXWLEN];
   int retval = OK;
   int i, j;
-  char_u *p;
+  char *p;
   int use_flags;
-  char_u *use_pfxlist;
+  char *use_pfxlist;
   int use_pfxlen;
   bool need_affix;
   char_u store_afflist[MAXWLEN];
-  char_u pfx_pfxlist[MAXWLEN];
-  size_t wordlen = STRLEN(word);
+  char pfx_pfxlist[MAXWLEN];
+  size_t wordlen = strlen(word);
   int use_condit;
 
   todo = (int)ht->ht_used;
-  for (hi = ht->ht_array; todo > 0 && retval == OK; ++hi) {
+  for (hi = ht->ht_array; todo > 0 && retval == OK; hi++) {
     if (!HASHITEM_EMPTY(hi)) {
       todo--;
       ah = HI2AH(hi);
@@ -3460,7 +3462,7 @@ static int store_aff_word(spellinfo_T *spin, char_u *word, char_u *afflist, afff
                || ae->ae_chop != NULL
                || ae->ae_flags != NULL)
               && (ae->ae_chop == NULL
-                  || STRLEN(ae->ae_chop) < wordlen)
+                  || strlen(ae->ae_chop) < wordlen)
               && (ae->ae_prog == NULL
                   || vim_regexec_prog(&ae->ae_prog, false, word, (colnr_T)0))
               && (((condit & CONDIT_CFIX) == 0)
@@ -3474,7 +3476,7 @@ static int store_aff_word(spellinfo_T *spin, char_u *word, char_u *afflist, afff
               if (ae->ae_add == NULL) {
                 *newword = NUL;
               } else {
-                STRLCPY(newword, ae->ae_add, MAXWLEN);
+                xstrlcpy(newword, ae->ae_add, MAXWLEN);
               }
               p = word;
               if (ae->ae_chop != NULL) {
@@ -3487,10 +3489,10 @@ static int store_aff_word(spellinfo_T *spin, char_u *word, char_u *afflist, afff
               STRCAT(newword, p);
             } else {
               // suffix: chop/add at the end of the word
-              STRLCPY(newword, word, MAXWLEN);
+              xstrlcpy(newword, word, MAXWLEN);
               if (ae->ae_chop != NULL) {
                 // Remove chop string.
-                p = newword + STRLEN(newword);
+                p = newword + strlen(newword);
                 i = mb_charlen(ae->ae_chop);
                 for (; i > 0; i--) {
                   MB_PTR_BACK(newword, p);
@@ -3511,16 +3513,18 @@ static int store_aff_word(spellinfo_T *spin, char_u *word, char_u *afflist, afff
               // Extract flags from the affix list.
               use_flags |= get_affix_flags(affile, ae->ae_flags);
 
-              if (affile->af_needaffix != 0 && flag_in_afflist(affile->af_flagtype, ae->ae_flags,
-                                                               affile->af_needaffix)) {
+              if (affile->af_needaffix != 0
+                  && flag_in_afflist(affile->af_flagtype, ae->ae_flags,
+                                     affile->af_needaffix)) {
                 need_affix = true;
               }
 
               // When there is a CIRCUMFIX flag the other affix
               // must also have it and we don't add the word
               // with one affix.
-              if (affile->af_circumfix != 0 && flag_in_afflist(affile->af_flagtype, ae->ae_flags,
-                                                               affile->af_circumfix)) {
+              if (affile->af_circumfix != 0
+                  && flag_in_afflist(affile->af_flagtype, ae->ae_flags,
+                                     affile->af_circumfix)) {
                 use_condit |= CONDIT_CFIX;
                 if ((condit & CONDIT_CFIX) == 0) {
                   need_affix = true;
@@ -3531,17 +3535,16 @@ static int store_aff_word(spellinfo_T *spin, char_u *word, char_u *afflist, afff
                   || spin->si_compflags != NULL) {
                 if (affile->af_pfxpostpone) {
                   // Get prefix IDS from the affix list.
-                  use_pfxlen = get_pfxlist(affile,
-                                           ae->ae_flags, store_afflist);
+                  use_pfxlen = get_pfxlist(affile, ae->ae_flags, store_afflist);
                 } else {
                   use_pfxlen = 0;
                 }
-                use_pfxlist = store_afflist;
+                use_pfxlist = (char *)store_afflist;
 
                 // Combine the prefix IDs. Avoid adding the
                 // same ID twice.
-                for (i = 0; i < pfxlen; ++i) {
-                  for (j = 0; j < use_pfxlen; ++j) {
+                for (i = 0; i < pfxlen; i++) {
+                  for (j = 0; j < use_pfxlen; j++) {
                     if (pfxlist[i] == use_pfxlist[j]) {
                       break;
                     }
@@ -3554,7 +3557,7 @@ static int store_aff_word(spellinfo_T *spin, char_u *word, char_u *afflist, afff
                 if (spin->si_compflags != NULL) {
                   // Get compound IDS from the affix list.
                   get_compflags(affile, ae->ae_flags,
-                                use_pfxlist + use_pfxlen);
+                                (char_u *)use_pfxlist + use_pfxlen);
                 } else {
                   use_pfxlist[use_pfxlen] = NUL;
                 }
@@ -3562,9 +3565,8 @@ static int store_aff_word(spellinfo_T *spin, char_u *word, char_u *afflist, afff
                 // Combine the list of compound flags.
                 // Concatenate them to the prefix IDs list.
                 // Avoid adding the same ID twice.
-                for (i = pfxlen; pfxlist[i] != NUL; ++i) {
-                  for (j = use_pfxlen;
-                       use_pfxlist[j] != NUL; ++j) {
+                for (i = pfxlen; pfxlist[i] != NUL; i++) {
+                  for (j = use_pfxlen; use_pfxlist[j] != NUL; j++) {
                     if (pfxlist[i] == use_pfxlist[j]) {
                       break;
                     }
@@ -3580,7 +3582,7 @@ static int store_aff_word(spellinfo_T *spin, char_u *word, char_u *afflist, afff
             // Obey a "COMPOUNDFORBIDFLAG" of the affix: don't
             // use the compound flags.
             if (use_pfxlist != NULL && ae->ae_compforbid) {
-              STRLCPY(pfx_pfxlist, use_pfxlist, use_pfxlen + 1);
+              xstrlcpy(pfx_pfxlist, use_pfxlist, (size_t)use_pfxlen + 1);
               use_pfxlist = pfx_pfxlist;
             }
 
@@ -3622,7 +3624,7 @@ static int store_aff_word(spellinfo_T *spin, char_u *word, char_u *afflist, afff
               if (store_aff_word(spin, newword, ae->ae_flags,
                                  affile, &affile->af_suff, xht,
                                  use_condit & (xht == NULL
-                                    ? ~0 :  ~CONDIT_SUF),
+                                               ? ~0 :  ~CONDIT_SUF),
                                  use_flags, use_pfxlist, pfxlen) == FAIL) {
                 retval = FAIL;
               }
@@ -3656,12 +3658,12 @@ static int store_aff_word(spellinfo_T *spin, char_u *word, char_u *afflist, afff
 }
 
 // Read a file with a list of words.
-static int spell_read_wordfile(spellinfo_T *spin, char_u *fname)
+static int spell_read_wordfile(spellinfo_T *spin, char *fname)
 {
   FILE *fd;
   long lnum = 0;
-  char_u rline[MAXLINELEN];
-  char_u *line;
+  char rline[MAXLINELEN];
+  char *line;
   char_u *pc = NULL;
   char_u *p;
   int l;
@@ -3672,13 +3674,13 @@ static int spell_read_wordfile(spellinfo_T *spin, char_u *fname)
   int regionmask;
 
   // Open the file.
-  fd = os_fopen((char *)fname, "r");
+  fd = os_fopen(fname, "r");
   if (fd == NULL) {
     semsg(_(e_notopen), fname);
     return FAIL;
   }
 
-  vim_snprintf((char *)IObuff, IOSIZE, _("Reading word file %s..."), fname);
+  vim_snprintf(IObuff, IOSIZE, _("Reading word file %s..."), fname);
   spell_message(spin, IObuff);
 
   // Read all the lines in the file one by one.
@@ -3692,8 +3694,8 @@ static int spell_read_wordfile(spellinfo_T *spin, char_u *fname)
     }
 
     // Remove CR, LF and white space from the end.
-    l = (int)STRLEN(rline);
-    while (l > 0 && rline[l - 1] <= ' ') {
+    l = (int)strlen(rline);
+    while (l > 0 && (uint8_t)rline[l - 1] <= ' ') {
       l--;
     }
     if (l == 0) {
@@ -3704,13 +3706,13 @@ static int spell_read_wordfile(spellinfo_T *spin, char_u *fname)
     // Convert from "/encoding={encoding}" to 'encoding' when needed.
     xfree(pc);
     if (spin->si_conv.vc_type != CONV_NONE) {
-      pc = string_convert(&spin->si_conv, rline, NULL);
+      pc = (char_u *)string_convert(&spin->si_conv, rline, NULL);
       if (pc == NULL) {
         smsg(_("Conversion failure for word in %s line %ld: %s"),
              fname, lnum, rline);
         continue;
       }
-      line = pc;
+      line = (char *)pc;
     } else {
       pc = NULL;
       line = rline;
@@ -3718,7 +3720,7 @@ static int spell_read_wordfile(spellinfo_T *spin, char_u *fname)
 
     if (*line == '/') {
       line++;
-      if (STRNCMP(line, "encoding=", 9) == 0) {
+      if (strncmp(line, "encoding=", 9) == 0) {
         if (spin->si_conv.vc_type != CONV_NONE) {
           smsg(_("Duplicate /encoding= line ignored in %s line %ld: %s"),
                fname, lnum, line - 1);
@@ -3726,14 +3728,13 @@ static int spell_read_wordfile(spellinfo_T *spin, char_u *fname)
           smsg(_("/encoding= line after word ignored in %s line %ld: %s"),
                fname, lnum, line - 1);
         } else {
-          char_u *enc;
+          char *enc;
 
           // Setup for conversion to 'encoding'.
           line += 9;
           enc = enc_canonize(line);
           if (!spin->si_ascii
-              && convert_setup(&spin->si_conv, enc,
-                               p_enc) == FAIL) {
+              && convert_setup(&spin->si_conv, enc, p_enc) == FAIL) {
             smsg(_("Conversion in %s not supported: from %s to %s"),
                  fname, line, p_enc);
           }
@@ -3743,17 +3744,17 @@ static int spell_read_wordfile(spellinfo_T *spin, char_u *fname)
         continue;
       }
 
-      if (STRNCMP(line, "regions=", 8) == 0) {
+      if (strncmp(line, "regions=", 8) == 0) {
         if (spin->si_region_count > 1) {
           smsg(_("Duplicate /regions= line ignored in %s line %ld: %s"),
                fname, lnum, line);
         } else {
           line += 8;
-          if (STRLEN(line) > MAXREGIONS * 2) {
+          if (strlen(line) > MAXREGIONS * 2) {
             smsg(_("Too many regions in %s line %ld: %s"),
                  fname, lnum, line);
           } else {
-            spin->si_region_count = (int)STRLEN(line) / 2;
+            spin->si_region_count = (int)strlen(line) / 2;
             STRCPY(spin->si_region_name, line);
 
             // Adjust the mask for a word valid in all regions.
@@ -3772,7 +3773,7 @@ static int spell_read_wordfile(spellinfo_T *spin, char_u *fname)
     regionmask = spin->si_region;
 
     // Check for flags and region after a slash.
-    p = (char_u *)vim_strchr((char *)line, '/');
+    p = (char_u *)vim_strchr(line, '/');
     if (p != NULL) {
       *p++ = NUL;
       while (*p != NUL) {
@@ -3822,7 +3823,7 @@ static int spell_read_wordfile(spellinfo_T *spin, char_u *fname)
   fclose(fd);
 
   if (spin->si_ascii && non_ascii > 0) {
-    vim_snprintf((char *)IObuff, IOSIZE,
+    vim_snprintf(IObuff, IOSIZE,
                  _("Ignored %d words with non-ASCII characters"), non_ascii);
     spell_message(spin, IObuff);
   }
@@ -3858,7 +3859,7 @@ static void *getroom(spellinfo_T *spin, size_t len, bool align)
     bl->sb_next = spin->si_blocks;
     spin->si_blocks = bl;
     bl->sb_used = 0;
-    ++spin->si_blocks_cnt;
+    spin->si_blocks_cnt++;
   }
 
   p = bl->sb_data + bl->sb_used;
@@ -3867,11 +3868,12 @@ static void *getroom(spellinfo_T *spin, size_t len, bool align)
   return p;
 }
 
-// Make a copy of a string into memory allocated with getroom().
-// Returns NULL when out of memory.
-static char_u *getroom_save(spellinfo_T *spin, char_u *s)
+/// Make a copy of a string into memory allocated with getroom().
+///
+/// @return  NULL when out of memory.
+static char *getroom_save(spellinfo_T *spin, char *s)
 {
-  const size_t s_size = STRLEN(s) + 1;
+  const size_t s_size = strlen(s) + 1;
   return memcpy(getroom(spin, s_size, false), s, s_size);
 }
 
@@ -3897,13 +3899,13 @@ static wordnode_T *wordtree_alloc(spellinfo_T *spin)
 
 /// Return true if "word" contains valid word characters.
 /// Control characters and trailing '/' are invalid.  Space is OK.
-static bool valid_spell_word(const char_u *word, const char_u *end)
+static bool valid_spell_word(const char *word, const char *end)
 {
-  if (!utf_valid_string(word, end)) {
+  if (!utf_valid_string((char_u *)word, (char_u *)end)) {
     return false;
   }
-  for (const char_u *p = word; *p != NUL && p < end; p += utfc_ptr2len((const char *)p)) {
-    if (*p < ' ' || (p[0] == '/' && p[1] == NUL)) {
+  for (const char *p = word; *p != NUL && p < end; p += utfc_ptr2len(p)) {
+    if ((uint8_t)(*p) < ' ' || (p[0] == '/' && p[1] == NUL)) {
       return false;
     }
   }
@@ -3922,10 +3924,10 @@ static bool valid_spell_word(const char_u *word, const char_u *end)
 /// @param region  supported region(s)
 /// @param pfxlist  list of prefix ids or null
 /// @param need_affix  only store word with affix id
-static int store_word(spellinfo_T *spin, char_u *word, int flags, int region, const char_u *pfxlist,
+static int store_word(spellinfo_T *spin, char *word, int flags, int region, const char *pfxlist,
                       bool need_affix)
 {
-  int len = (int)STRLEN(word);
+  int len = (int)strlen(word);
   int ct = captype(word, word + len);
   char_u foldword[MAXWLEN];
   int res = OK;
@@ -3935,8 +3937,8 @@ static int store_word(spellinfo_T *spin, char_u *word, int flags, int region, co
     return FAIL;
   }
 
-  (void)spell_casefold(curwin, word, len, foldword, MAXWLEN);
-  for (const char_u *p = pfxlist; res == OK; p++) {
+  (void)spell_casefold(curwin, word, len, (char *)foldword, MAXWLEN);
+  for (const char_u *p = (char_u *)pfxlist; res == OK; p++) {
     if (!need_affix || (p != NULL && *p != NUL)) {
       res = tree_add_word(spin, foldword, spin->si_foldroot, ct | flags,
                           region, p == NULL ? 0 : *p);
@@ -3945,19 +3947,19 @@ static int store_word(spellinfo_T *spin, char_u *word, int flags, int region, co
       break;
     }
   }
-  ++spin->si_foldwcount;
+  spin->si_foldwcount++;
 
   if (res == OK && (ct == WF_KEEPCAP || (flags & WF_KEEPCAP))) {
-    for (const char_u *p = pfxlist; res == OK; p++) {
+    for (const char_u *p = (char_u *)pfxlist; res == OK; p++) {
       if (!need_affix || (p != NULL && *p != NUL)) {
-        res = tree_add_word(spin, word, spin->si_keeproot, flags,
+        res = tree_add_word(spin, (char_u *)word, spin->si_keeproot, flags,
                             region, p == NULL ? 0 : *p);
       }
       if (p == NULL || *p == NUL) {
         break;
       }
     }
-    ++spin->si_keepwcount;
+    spin->si_keepwcount++;
   }
   return res;
 }
@@ -3966,8 +3968,8 @@ static int store_word(spellinfo_T *spin, char_u *word, int flags, int region, co
 // When "flags" < 0 we are adding to the prefix tree where "flags" is used for
 // "rare" and "region" is the condition nr.
 // Returns FAIL when out of memory.
-static int tree_add_word(spellinfo_T *spin, char_u *word, wordnode_T *root, int flags, int region,
-                         int affixID)
+static int tree_add_word(spellinfo_T *spin, const char_u *word, wordnode_T *root, int flags,
+                         int region, int affixID)
 {
   wordnode_T *node = root;
   wordnode_T *np;
@@ -3976,12 +3978,12 @@ static int tree_add_word(spellinfo_T *spin, char_u *word, wordnode_T *root, int
   int i;
 
   // Add each byte of the word to the tree, including the NUL at the end.
-  for (i = 0;; ++i) {
+  for (i = 0;; i++) {
     // When there is more than one reference to this node we need to make
     // a copy, so that we can modify it.  Copy the whole list of siblings
     // (we don't optimize for a partly shared list of siblings).
     if (node != NULL && node->wn_refs > 1) {
-      --node->wn_refs;
+      node->wn_refs--;
       copyprev = prev;
       for (copyp = node; copyp != NULL; copyp = copyp->wn_sibling) {
         // Allocate a new node and copy the info.
@@ -3991,7 +3993,7 @@ static int tree_add_word(spellinfo_T *spin, char_u *word, wordnode_T *root, int
         }
         np->wn_child = copyp->wn_child;
         if (np->wn_child != NULL) {
-          ++np->wn_child->wn_refs;              // child gets extra ref
+          np->wn_child->wn_refs++;              // child gets extra ref
         }
         np->wn_byte = copyp->wn_byte;
         if (np->wn_byte == NUL) {
@@ -4078,7 +4080,7 @@ static int tree_add_word(spellinfo_T *spin, char_u *word, wordnode_T *root, int
 #endif
 
   // count nr of words added since last message
-  ++spin->si_msg_count;
+  spin->si_msg_count++;
 
   if (spin->si_compress_cnt > 1) {
     if (--spin->si_compress_cnt == 1) {
@@ -4097,7 +4099,7 @@ static int tree_add_word(spellinfo_T *spin, char_u *word, wordnode_T *root, int
   // 3. When compressed before, added "compress_added" words
   //    (si_compress_cnt == 1) and the number of free nodes drops below the
   //    maximum word length.
-#ifndef SPELL_COMPRESS_ALLWAYS
+#ifndef SPELL_COMPRESS_ALWAYS
   if (spin->si_compress_cnt == 1       // NOLINT(readability/braces)
       ? spin->si_free_count < MAXWLEN
       : spin->si_blocks_cnt >= compress_start)
@@ -4173,7 +4175,7 @@ static int deref_wordnode(spellinfo_T *spin, wordnode_T *node)
       free_wordnode(spin, np);
       cnt++;
     }
-    ++cnt;          // length field
+    cnt++;          // length field
   }
   return cnt;
 }
@@ -4185,7 +4187,7 @@ static void free_wordnode(spellinfo_T *spin, wordnode_T *n)
 {
   n->wn_child = spin->si_first_free;
   spin->si_first_free = n;
-  ++spin->si_free_count;
+  spin->si_free_count++;
 }
 
 // Compress a tree: find tails that are identical and can be shared.
@@ -4198,31 +4200,33 @@ static void wordtree_compress(spellinfo_T *spin, wordnode_T *root, const char *n
 
   // Skip the root itself, it's not actually used.  The first sibling is the
   // start of the tree.
-  if (root->wn_sibling != NULL) {
-    hash_init(&ht);
-    const long n = node_compress(spin, root->wn_sibling, &ht, &tot);
+  if (root->wn_sibling == NULL) {
+    return;
+  }
+
+  hash_init(&ht);
+  const long n = node_compress(spin, root->wn_sibling, &ht, &tot);
 
 #ifndef SPELL_PRINTTREE
-    if (spin->si_verbose || p_verbose > 2)
+  if (spin->si_verbose || p_verbose > 2)
 #endif
-    {
-      if (tot > 1000000) {
-        perc = (tot - n) / (tot / 100);
-      } else if (tot == 0) {
-        perc = 0;
-      } else {
-        perc = (tot - n) * 100 / tot;
-      }
-      vim_snprintf((char *)IObuff, IOSIZE,
-                   _("Compressed %s of %ld nodes; %ld (%ld%%) remaining"),
-                   name, tot, tot - n, perc);
-      spell_message(spin, IObuff);
+  {
+    if (tot > 1000000) {
+      perc = (tot - n) / (tot / 100);
+    } else if (tot == 0) {
+      perc = 0;
+    } else {
+      perc = (tot - n) * 100 / tot;
     }
+    vim_snprintf(IObuff, IOSIZE,
+                 _("Compressed %s of %ld nodes; %ld (%ld%%) remaining"),
+                 name, tot, tot - n, perc);
+    spell_message(spin, IObuff);
+  }
 #ifdef SPELL_PRINTTREE
-    spell_print_tree(root->wn_sibling);
+  spell_print_tree(root->wn_sibling);
 #endif
-    hash_clear(&ht);
-  }
+  hash_clear(&ht);
 }
 
 /// Compress a node, its siblings and its children, depth first.
@@ -4252,9 +4256,9 @@ static long node_compress(spellinfo_T *spin, wordnode_T *node, hashtab_T *ht, lo
       compressed += node_compress(spin, child, ht, tot);
 
       // Try to find an identical child.
-      hash = hash_hash(child->wn_u1.hashkey);
+      hash = hash_hash((char *)child->wn_u1.hashkey);
       hi = hash_lookup(ht, (const char *)child->wn_u1.hashkey,
-                       STRLEN(child->wn_u1.hashkey), hash);
+                       strlen((char *)child->wn_u1.hashkey), hash);
       if (!HASHITEM_EMPTY(hi)) {
         // There are children we encountered before with a hash value
         // identical to the current child.  Now check if there is one
@@ -4264,7 +4268,7 @@ static long node_compress(spellinfo_T *spin, wordnode_T *node, hashtab_T *ht, lo
             // Found one!  Now use that child in place of the
             // current one.  This means the current child and all
             // its siblings is unlinked from the tree.
-            ++tp->wn_refs;
+            tp->wn_refs++;
             compressed += deref_wordnode(spin, child);
             np->wn_child = tp;
             break;
@@ -4281,7 +4285,7 @@ static long node_compress(spellinfo_T *spin, wordnode_T *node, hashtab_T *ht, lo
       } else {
         // No other child has this hash value, add it to the
         // hashtable.
-        hash_add_item(ht, hi, child->wn_u1.hashkey, hash);
+        hash_add_item(ht, hi, (char *)child->wn_u1.hashkey, hash);
       }
     }
   }
@@ -4341,23 +4345,24 @@ static bool node_equal(wordnode_T *n1, wordnode_T *n2)
   return p1 == NULL && p2 == NULL;
 }
 
-// Function given to qsort() to sort the REP items on "from" string.
+/// Function given to qsort() to sort the REP items on "from" string.
 static int rep_compare(const void *s1, const void *s2)
 {
   fromto_T *p1 = (fromto_T *)s1;
   fromto_T *p2 = (fromto_T *)s2;
 
-  return STRCMP(p1->ft_from, p2->ft_from);
+  return strcmp(p1->ft_from, p2->ft_from);
 }
 
-// Write the Vim .spl file "fname".
-// Return OK/FAIL.
-static int write_vim_spell(spellinfo_T *spin, char_u *fname)
+/// Write the Vim .spl file "fname".
+///
+/// @return  OK/FAIL.
+static int write_vim_spell(spellinfo_T *spin, char *fname)
 {
   int retval = OK;
   int regionmask;
 
-  FILE *fd = os_fopen((char *)fname, "w");
+  FILE *fd = os_fopen(fname, "w");
   if (fd == NULL) {
     semsg(_(e_notopen), fname);
     return FAIL;
@@ -4379,7 +4384,7 @@ static int write_vim_spell(spellinfo_T *spin, char_u *fname)
   if (spin->si_info != NULL) {
     putc(SN_INFO, fd);                                  // <sectionID>
     putc(0, fd);                                        // <sectionflags>
-    size_t i = STRLEN(spin->si_info);
+    size_t i = strlen(spin->si_info);
     put_bytes(fd, i, 4);                                // <sectionlen>
     fwv &= fwrite(spin->si_info, i, 1, fd);             // <infotext>
   }
@@ -4422,7 +4427,7 @@ static int write_vim_spell(spellinfo_T *spin, char_u *fname)
     put_bytes(fd, 1 + 128 + 2 + l, 4);                  // <sectionlen>
 
     fputc(128, fd);                                     // <charflagslen>
-    for (size_t i = 128; i < 256; ++i) {
+    for (size_t i = 128; i < 256; i++) {
       flags = 0;
       if (spelltab.st_isw[i]) {
         flags |= CF_WORD;
@@ -4442,7 +4447,7 @@ static int write_vim_spell(spellinfo_T *spin, char_u *fname)
     putc(SN_MIDWORD, fd);                               // <sectionID>
     putc(SNF_REQUIRED, fd);                             // <sectionflags>
 
-    size_t i = STRLEN(spin->si_midword);
+    size_t i = strlen(spin->si_midword);
     put_bytes(fd, i, 4);                                // <sectionlen>
     fwv &= fwrite(spin->si_midword, i, 1, fd);
     // <midword>
@@ -4466,7 +4471,7 @@ static int write_vim_spell(spellinfo_T *spin, char_u *fname)
   // round 1: SN_REP section
   // round 2: SN_SAL section (unless SN_SOFO is used)
   // round 3: SN_REPSAL section
-  for (unsigned int round = 1; round <= 3; ++round) {
+  for (unsigned int round = 1; round <= 3; round++) {
     garray_T *gap;
     if (round == 1) {
       gap = &spin->si_rep;
@@ -4500,13 +4505,13 @@ static int write_vim_spell(spellinfo_T *spin, char_u *fname)
     // Compute the length of what follows.
     size_t l = 2;  // count <repcount> or <salcount>
     assert(gap->ga_len >= 0);
-    for (size_t i = 0; i < (size_t)gap->ga_len; ++i) {
+    for (size_t i = 0; i < (size_t)gap->ga_len; i++) {
       fromto_T *ftp = &((fromto_T *)gap->ga_data)[i];
-      l += 1 + STRLEN(ftp->ft_from);  // count <*fromlen> and <*from>
-      l += 1 + STRLEN(ftp->ft_to);    // count <*tolen> and <*to>
+      l += 1 + strlen(ftp->ft_from);  // count <*fromlen> and <*from>
+      l += 1 + strlen(ftp->ft_to);    // count <*tolen> and <*to>
     }
     if (round == 2) {
-      ++l;                            // count <salflags>
+      l++;                            // count <salflags>
     }
     put_bytes(fd, l, 4);                                // <sectionlen>
 
@@ -4525,13 +4530,13 @@ static int write_vim_spell(spellinfo_T *spin, char_u *fname)
     }
 
     put_bytes(fd, (uintmax_t)gap->ga_len, 2);    // <repcount> or <salcount>
-    for (size_t i = 0; i < (size_t)gap->ga_len; ++i) {
+    for (size_t i = 0; i < (size_t)gap->ga_len; i++) {
       // <rep> : <repfromlen> <repfrom> <reptolen> <repto>
       // <sal> : <salfromlen> <salfrom> <saltolen> <salto>
       fromto_T *ftp = &((fromto_T *)gap->ga_data)[i];
-      for (unsigned int rr = 1; rr <= 2; ++rr) {
-        char_u *p = rr == 1 ? ftp->ft_from : ftp->ft_to;
-        l = STRLEN(p);
+      for (unsigned int rr = 1; rr <= 2; rr++) {
+        char *p = rr == 1 ? ftp->ft_from : ftp->ft_to;
+        l = strlen(p);
         assert(l < INT_MAX);
         putc((int)l, fd);
         if (l > 0) {
@@ -4547,13 +4552,13 @@ static int write_vim_spell(spellinfo_T *spin, char_u *fname)
     putc(SN_SOFO, fd);                                  // <sectionID>
     putc(0, fd);                                        // <sectionflags>
 
-    size_t l = STRLEN(spin->si_sofofr);
-    put_bytes(fd, l + STRLEN(spin->si_sofoto) + 4, 4);  // <sectionlen>
+    size_t l = strlen(spin->si_sofofr);
+    put_bytes(fd, l + strlen(spin->si_sofoto) + 4, 4);  // <sectionlen>
 
     put_bytes(fd, l, 2);                                // <sofofromlen>
     fwv &= fwrite(spin->si_sofofr, l, 1, fd);           // <sofofrom>
 
-    l = STRLEN(spin->si_sofoto);
+    l = strlen(spin->si_sofoto);
     put_bytes(fd, l, 2);                                // <sofotolen>
     fwv &= fwrite(spin->si_sofoto, l, 1, fd);           // <sofoto>
   }
@@ -4566,15 +4571,15 @@ static int write_vim_spell(spellinfo_T *spin, char_u *fname)
 
     // round 1: count the bytes
     // round 2: write the bytes
-    for (unsigned int round = 1; round <= 2; ++round) {
+    for (unsigned int round = 1; round <= 2; round++) {
       size_t todo;
       size_t len = 0;
       hashitem_T *hi;
 
       todo = spin->si_commonwords.ht_used;
-      for (hi = spin->si_commonwords.ht_array; todo > 0; ++hi) {
+      for (hi = spin->si_commonwords.ht_array; todo > 0; hi++) {
         if (!HASHITEM_EMPTY(hi)) {
-          size_t l = STRLEN(hi->hi_key) + 1;
+          size_t l = strlen(hi->hi_key) + 1;
           len += l;
           if (round == 2) {                             // <word>
             fwv &= fwrite(hi->hi_key, l, 1, fd);
@@ -4640,10 +4645,10 @@ static int write_vim_spell(spellinfo_T *spin, char_u *fname)
     putc(SN_COMPOUND, fd);                              // <sectionID>
     putc(0, fd);                                        // <sectionflags>
 
-    size_t l = STRLEN(spin->si_compflags);
+    size_t l = strlen(spin->si_compflags);
     assert(spin->si_comppat.ga_len >= 0);
     for (size_t i = 0; i < (size_t)spin->si_comppat.ga_len; i++) {
-      l += STRLEN(((char **)(spin->si_comppat.ga_data))[i]) + 1;
+      l += strlen(((char **)(spin->si_comppat.ga_data))[i]) + 1;
     }
     put_bytes(fd, l + 7, 4);                            // <sectionlen>
 
@@ -4655,12 +4660,12 @@ static int write_vim_spell(spellinfo_T *spin, char_u *fname)
     put_bytes(fd, (uintmax_t)spin->si_comppat.ga_len, 2);  // <comppatcount>
     for (size_t i = 0; i < (size_t)spin->si_comppat.ga_len; i++) {
       char *p = ((char **)(spin->si_comppat.ga_data))[i];
-      assert(STRLEN(p) < INT_MAX);
-      putc((int)STRLEN(p), fd);                         // <comppatlen>
-      fwv &= fwrite(p, STRLEN(p), 1, fd);               // <comppattext>
+      assert(strlen(p) < INT_MAX);
+      putc((int)strlen(p), fd);                         // <comppatlen>
+      fwv &= fwrite(p, strlen(p), 1, fd);               // <comppattext>
     }
     // <compflags>
-    fwv &= fwrite(spin->si_compflags, STRLEN(spin->si_compflags), 1, fd);
+    fwv &= fwrite(spin->si_compflags, strlen(spin->si_compflags), 1, fd);
   }
 
   // SN_NOBREAK: NOBREAK flag
@@ -4679,7 +4684,7 @@ static int write_vim_spell(spellinfo_T *spin, char_u *fname)
     putc(SN_SYLLABLE, fd);                              // <sectionID>
     putc(0, fd);                                        // <sectionflags>
 
-    size_t l = STRLEN(spin->si_syllable);
+    size_t l = strlen(spin->si_syllable);
     put_bytes(fd, l, 4);                                // <sectionlen>
     fwv &= fwrite(spin->si_syllable, l, 1, fd);         // <syllable>
   }
@@ -4689,7 +4694,7 @@ static int write_vim_spell(spellinfo_T *spin, char_u *fname)
 
   // <LWORDTREE>  <KWORDTREE>  <PREFIXTREE>
   spin->si_memtot = 0;
-  for (unsigned int round = 1; round <= 3; ++round) {
+  for (unsigned int round = 1; round <= 3; round++) {
     wordnode_T *tree;
     if (round == 1) {
       tree = spin->si_foldroot->wn_sibling;
@@ -4878,27 +4883,29 @@ void ex_mkspell(exarg_T *eap)
 {
   int fcount;
   char **fnames;
-  char_u *arg = (char_u *)eap->arg;
+  char *arg = eap->arg;
   bool ascii = false;
 
-  if (STRNCMP(arg, "-ascii", 6) == 0) {
+  if (strncmp(arg, "-ascii", 6) == 0) {
     ascii = true;
-    arg = (char_u *)skipwhite((char *)arg + 6);
+    arg = skipwhite(arg + 6);
   }
 
   // Expand all the remaining arguments (e.g., $VIMRUNTIME).
-  if (get_arglist_exp(arg, &fcount, &fnames, false) == OK) {
-    mkspell(fcount, fnames, ascii, eap->forceit, false);
-    FreeWild(fcount, fnames);
+  if (get_arglist_exp(arg, &fcount, &fnames, false) != OK) {
+    return;
   }
+
+  mkspell(fcount, fnames, ascii, eap->forceit, false);
+  FreeWild(fcount, fnames);
 }
 
 // Create the .sug file.
 // Uses the soundfold info in "spin".
 // Writes the file with the name "wfname", with ".spl" changed to ".sug".
-static void spell_make_sugfile(spellinfo_T *spin, char_u *wfname)
+static void spell_make_sugfile(spellinfo_T *spin, char *wfname)
 {
-  char_u *fname = NULL;
+  char *fname = NULL;
   int len;
   slang_T *slang;
   bool free_slang = false;
@@ -4909,13 +4916,13 @@ static void spell_make_sugfile(spellinfo_T *spin, char_u *wfname)
   // of the code for the soundfolding stuff.
   // It might have been done already by spell_reload_one().
   for (slang = first_lang; slang != NULL; slang = slang->sl_next) {
-    if (path_full_compare((char *)wfname, (char *)slang->sl_fname, false, true)
+    if (path_full_compare(wfname, slang->sl_fname, false, true)
         == kEqualFiles) {
       break;
     }
   }
   if (slang == NULL) {
-    spell_message(spin, (char_u *)_("Reading back spell file..."));
+    spell_message(spin, _("Reading back spell file..."));
     slang = spell_load_file(wfname, NULL, NULL, false);
     if (slang == NULL) {
       return;
@@ -4933,7 +4940,7 @@ static void spell_make_sugfile(spellinfo_T *spin, char_u *wfname)
 
   // Go through the trie of good words, soundfold each word and add it to
   // the soundfold trie.
-  spell_message(spin, (char_u *)_("Performing soundfolding..."));
+  spell_message(spin, _("Performing soundfolding..."));
   if (sug_filltree(spin, slang) == FAIL) {
     goto theend;
   }
@@ -4950,14 +4957,14 @@ static void spell_make_sugfile(spellinfo_T *spin, char_u *wfname)
        (int64_t)spin->si_spellbuf->b_ml.ml_line_count);
 
   // Compress the soundfold trie.
-  spell_message(spin, (char_u *)_(msg_compressing));
+  spell_message(spin, _(msg_compressing));
   wordtree_compress(spin, spin->si_foldroot, "case-folded");
 
   // Write the .sug file.
   // Make the file name by changing ".spl" to ".sug".
   fname = xmalloc(MAXPATHL);
-  STRLCPY(fname, wfname, MAXPATHL);
-  len = (int)STRLEN(fname);
+  xstrlcpy(fname, wfname, MAXPATHL);
+  len = (int)strlen(fname);
   fname[len - 2] = 'u';
   fname[len - 1] = 'g';
   sug_write(spin, fname);
@@ -4994,7 +5001,7 @@ static int sug_filltree(spellinfo_T *spin, slang_T *slang)
 
   // Go through the whole case-folded tree, soundfold each word and put it
   // in the trie.
-  byts = slang->sl_fbyts;
+  byts = (char_u *)slang->sl_fbyts;
   idxs = slang->sl_fidxs;
 
   arridx[0] = 0;
@@ -5015,13 +5022,13 @@ static int sug_filltree(spellinfo_T *spin, slang_T *slang)
     } else {
       // Do one more byte at this node.
       n = arridx[depth] + curi[depth];
-      ++curi[depth];
+      curi[depth]++;
 
       c = byts[n];
       if (c == 0) {
         // Sound-fold the word.
         tword[depth] = NUL;
-        spell_soundfold(slang, tword, true, tsalword);
+        spell_soundfold(slang, (char *)tword, true, (char *)tsalword);
 
         // We use the "flags" field for the MSB of the wordnr,
         // "region" for the LSB of the wordnr.
@@ -5185,16 +5192,16 @@ static int offset2bytes(int nr, char_u *buf)
 }
 
 // Write the .sug file in "fname".
-static void sug_write(spellinfo_T *spin, char_u *fname)
+static void sug_write(spellinfo_T *spin, char *fname)
 {
   // Create the file.  Note that an existing file is silently overwritten!
-  FILE *fd = os_fopen((char *)fname, "w");
+  FILE *fd = os_fopen(fname, "w");
   if (fd == NULL) {
     semsg(_(e_notopen), fname);
     return;
   }
 
-  vim_snprintf((char *)IObuff, IOSIZE,
+  vim_snprintf(IObuff, IOSIZE,
                _("Writing suggestion file %s..."), fname);
   spell_message(spin, IObuff);
 
@@ -5233,10 +5240,10 @@ static void sug_write(spellinfo_T *spin, char_u *fname)
   assert(wcount >= 0);
   put_bytes(fd, (uintmax_t)wcount, 4);                  // <sugwcount>
 
-  for (linenr_T lnum = 1; lnum <= wcount; ++lnum) {
+  for (linenr_T lnum = 1; lnum <= wcount; lnum++) {
     // <sugline>: <sugnr> ... NUL
-    char_u *line = ml_get_buf(spin->si_spellbuf, lnum, false);
-    size_t len = STRLEN(line) + 1;
+    char *line = ml_get_buf(spin->si_spellbuf, lnum, false);
+    size_t len = strlen(line) + 1;
     if (fwrite(line, len, 1, fd) == 0) {
       emsg(_(e_write));
       goto theend;
@@ -5250,7 +5257,7 @@ static void sug_write(spellinfo_T *spin, char_u *fname)
     emsg(_(e_write));
   }
 
-  vim_snprintf((char *)IObuff, IOSIZE,
+  vim_snprintf(IObuff, IOSIZE,
                _("Estimated runtime memory use: %d bytes"), spin->si_memtot);
   spell_message(spin, IObuff);
 
@@ -5270,8 +5277,7 @@ theend:
 /// @param added_word  invoked through "zg"
 static void mkspell(int fcount, char **fnames, bool ascii, bool over_write, bool added_word)
 {
-  char_u *fname = NULL;
-  char_u *wfname;
+  char *fname = NULL;
   char **innames;
   int incount;
   afffile_T *(afile[MAXREGIONS]);
@@ -5288,9 +5294,9 @@ static void mkspell(int fcount, char **fnames, bool ascii, bool over_write, bool
   ga_init(&spin.si_rep, (int)sizeof(fromto_T), 20);
   ga_init(&spin.si_repsal, (int)sizeof(fromto_T), 20);
   ga_init(&spin.si_sal, (int)sizeof(fromto_T), 20);
-  ga_init(&spin.si_map, (int)sizeof(char_u), 100);
-  ga_init(&spin.si_comppat, (int)sizeof(char_u *), 20);
-  ga_init(&spin.si_prefcond, (int)sizeof(char_u *), 50);
+  ga_init(&spin.si_map, (int)sizeof(char), 100);
+  ga_init(&spin.si_comppat, (int)sizeof(char *), 20);
+  ga_init(&spin.si_prefcond, (int)sizeof(char *), 50);
   hash_init(&spin.si_commonwords);
   spin.si_newcompID = 127;      // start compound ID at first maximum
 
@@ -5299,43 +5305,43 @@ static void mkspell(int fcount, char **fnames, bool ascii, bool over_write, bool
   innames = &fnames[fcount == 1 ? 0 : 1];
   incount = fcount - 1;
 
-  wfname = xmalloc(MAXPATHL);
+  char *wfname = xmalloc(MAXPATHL);
 
   if (fcount >= 1) {
-    len = (int)STRLEN(fnames[0]);
-    if (fcount == 1 && len > 4 && STRCMP(fnames[0] + len - 4, ".add") == 0) {
+    len = (int)strlen(fnames[0]);
+    if (fcount == 1 && len > 4 && strcmp(fnames[0] + len - 4, ".add") == 0) {
       // For ":mkspell path/en.latin1.add" output file is
       // "path/en.latin1.add.spl".
       incount = 1;
-      vim_snprintf((char *)wfname, MAXPATHL, "%s.spl", fnames[0]);
+      vim_snprintf(wfname, MAXPATHL, "%s.spl", fnames[0]);
     } else if (fcount == 1) {
       // For ":mkspell path/vim" output file is "path/vim.latin1.spl".
       incount = 1;
-      vim_snprintf((char *)wfname, MAXPATHL, SPL_FNAME_TMPL,
-                   fnames[0], spin.si_ascii ? (char_u *)"ascii" : spell_enc());
-    } else if (len > 4 && STRCMP(fnames[0] + len - 4, ".spl") == 0) {
+      vim_snprintf(wfname, MAXPATHL, SPL_FNAME_TMPL,
+                   fnames[0], spin.si_ascii ? "ascii" : spell_enc());
+    } else if (len > 4 && strcmp(fnames[0] + len - 4, ".spl") == 0) {
       // Name ends in ".spl", use as the file name.
-      STRLCPY(wfname, fnames[0], MAXPATHL);
+      xstrlcpy(wfname, fnames[0], MAXPATHL);
     } else {
       // Name should be language, make the file name from it.
-      vim_snprintf((char *)wfname, MAXPATHL, SPL_FNAME_TMPL,
-                   fnames[0], spin.si_ascii ? (char_u *)"ascii" : spell_enc());
+      vim_snprintf(wfname, MAXPATHL, SPL_FNAME_TMPL,
+                   fnames[0], spin.si_ascii ? "ascii" : spell_enc());
     }
 
     // Check for .ascii.spl.
-    if (strstr(path_tail((char *)wfname), SPL_FNAME_ASCII) != NULL) {
+    if (strstr(path_tail(wfname), SPL_FNAME_ASCII) != NULL) {
       spin.si_ascii = true;
     }
 
     // Check for .add.spl.
-    if (strstr(path_tail((char *)wfname), SPL_FNAME_ADD) != NULL) {
+    if (strstr(path_tail(wfname), SPL_FNAME_ADD) != NULL) {
       spin.si_add = true;
     }
   }
 
   if (incount <= 0) {
     emsg(_(e_invarg));          // need at least output and input names
-  } else if (vim_strchr(path_tail((char *)wfname), '_') != NULL) {
+  } else if (vim_strchr(path_tail(wfname), '_') != NULL) {
     emsg(_("E751: Output file name must not have region name"));
   } else if (incount > MAXREGIONS) {
     semsg(_("E754: Only up to %d regions supported"), MAXREGIONS);
@@ -5355,12 +5361,12 @@ static void mkspell(int fcount, char **fnames, bool ascii, bool over_write, bool
 
     // Init the aff and dic pointers.
     // Get the region names if there are more than 2 arguments.
-    for (i = 0; i < incount; ++i) {
+    for (i = 0; i < incount; i++) {
       afile[i] = NULL;
 
       if (incount > 1) {
-        len = (int)STRLEN(innames[i]);
-        if (STRLEN(path_tail((char *)innames[i])) < 5
+        len = (int)strlen(innames[i]);
+        if (strlen(path_tail(innames[i])) < 5
             || innames[i][len - 3] != '_') {
           semsg(_("E755: Invalid region in %s"), innames[i]);
           goto theend;
@@ -5387,11 +5393,11 @@ static void mkspell(int fcount, char **fnames, bool ascii, bool over_write, bool
     // Read all the .aff and .dic files.
     // Text is converted to 'encoding'.
     // Words are stored in the case-folded and keep-case trees.
-    for (i = 0; i < incount && !error; ++i) {
+    for (i = 0; i < incount && !error; i++) {
       spin.si_conv.vc_type = CONV_NONE;
       spin.si_region = 1 << i;
 
-      vim_snprintf((char *)fname, MAXPATHL, "%s.aff", innames[i]);
+      vim_snprintf(fname, MAXPATHL, "%s.aff", innames[i]);
       if (os_path_exists(fname)) {
         // Read the .aff file.  Will init "spin->si_conv" based on the
         // "SET" line.
@@ -5400,8 +5406,7 @@ static void mkspell(int fcount, char **fnames, bool ascii, bool over_write, bool
           error = true;
         } else {
           // Read the .dic file and store the words in the trees.
-          vim_snprintf((char *)fname, MAXPATHL, "%s.dic",
-                       innames[i]);
+          vim_snprintf(fname, MAXPATHL, "%s.dic", innames[i]);
           if (spell_read_dic(&spin, fname, afile[i]) == FAIL) {
             error = true;
           }
@@ -5409,7 +5414,7 @@ static void mkspell(int fcount, char **fnames, bool ascii, bool over_write, bool
       } else {
         // No .aff file, try reading the file as a word list.  Store
         // the words in the trees.
-        if (spell_read_wordfile(&spin, (char_u *)innames[i]) == FAIL) {
+        if (spell_read_wordfile(&spin, innames[i]) == FAIL) {
           error = true;
         }
       }
@@ -5424,7 +5429,7 @@ static void mkspell(int fcount, char **fnames, bool ascii, bool over_write, bool
 
     if (!error && !got_int) {
       // Combine tails in the tree.
-      spell_message(&spin, (char_u *)_(msg_compressing));
+      spell_message(&spin, _(msg_compressing));
       wordtree_compress(&spin, spin.si_foldroot, "case-folded");
       wordtree_compress(&spin, spin.si_keeproot, "keep-case");
       wordtree_compress(&spin, spin.si_prefroot, "prefixes");
@@ -5432,14 +5437,14 @@ static void mkspell(int fcount, char **fnames, bool ascii, bool over_write, bool
 
     if (!error && !got_int) {
       // Write the info in the spell file.
-      vim_snprintf((char *)IObuff, IOSIZE,
+      vim_snprintf(IObuff, IOSIZE,
                    _("Writing spell file %s..."), wfname);
       spell_message(&spin, IObuff);
 
       error = write_vim_spell(&spin, wfname) == FAIL;
 
-      spell_message(&spin, (char_u *)_("Done!"));
-      vim_snprintf((char *)IObuff, IOSIZE,
+      spell_message(&spin, _("Done!"));
+      vim_snprintf(IObuff, IOSIZE,
                    _("Estimated runtime memory use: %d bytes"), spin.si_memtot);
       spell_message(&spin, IObuff);
 
@@ -5459,7 +5464,7 @@ static void mkspell(int fcount, char **fnames, bool ascii, bool over_write, bool
     hash_clear_all(&spin.si_commonwords, 0);
 
     // Free the .aff file structures.
-    for (i = 0; i < incount; ++i) {
+    for (i = 0; i < incount; i++) {
       if (afile[i] != NULL) {
         spell_free_aff(afile[i]);
       }
@@ -5482,14 +5487,14 @@ theend:
 
 // Display a message for spell file processing when 'verbose' is set or using
 // ":mkspell".  "str" can be IObuff.
-static void spell_message(const spellinfo_T *spin, char_u *str)
+static void spell_message(const spellinfo_T *spin, char *str)
   FUNC_ATTR_NONNULL_ALL
 {
   if (spin->si_verbose || p_verbose > 2) {
     if (!spin->si_verbose) {
       verbose_enter();
     }
-    msg((char *)str);
+    msg(str);
     ui_flush();
     if (!spin->si_verbose) {
       verbose_leave();
@@ -5503,7 +5508,7 @@ static void spell_message(const spellinfo_T *spin, char_u *str)
 // ":[count]spellrare  {word}"
 void ex_spell(exarg_T *eap)
 {
-  spell_add_word((char_u *)eap->arg, (int)STRLEN(eap->arg),
+  spell_add_word(eap->arg, (int)strlen(eap->arg),
                  eap->cmdidx == CMD_spellwrong ? SPELL_ADD_BAD :
                  eap->cmdidx == CMD_spellrare ? SPELL_ADD_RARE : SPELL_ADD_GOOD,
                  eap->forceit ? 0 : (int)eap->line2,
@@ -5515,17 +5520,17 @@ void ex_spell(exarg_T *eap)
 /// @param what  SPELL_ADD_ values
 /// @param idx  "zG" and "zW": zero, otherwise index in 'spellfile'
 /// @param bool  // true for "zug", "zuG", "zuw" and "zuW"
-void spell_add_word(char_u *word, int len, SpellAddType what, int idx, bool undo)
+void spell_add_word(char *word, int len, SpellAddType what, int idx, bool undo)
 {
   FILE *fd = NULL;
   buf_T *buf = NULL;
   bool new_spf = false;
   char *fname;
-  char_u *fnamebuf = NULL;
-  char_u line[MAXWLEN * 2];
+  char *fnamebuf = NULL;
+  char line[MAXWLEN * 2];
   long fpos, fpos_next = 0;
   int i;
-  char_u *spf;
+  char *spf;
 
   if (!valid_spell_word(word, word + len)) {
     emsg(_(e_illegal_character_in_word));
@@ -5539,7 +5544,7 @@ void spell_add_word(char_u *word, int len, SpellAddType what, int idx, bool undo
         return;
       }
     }
-    fname = (char *)int_wordlist;
+    fname = int_wordlist;
   } else {
     // If 'spellfile' isn't set figure out a good default value.
     if (*curwin->w_s->b_p_spf == NUL) {
@@ -5554,7 +5559,7 @@ void spell_add_word(char_u *word, int len, SpellAddType what, int idx, bool undo
     fnamebuf = xmalloc(MAXPATHL);
 
     for (spf = curwin->w_s->b_p_spf, i = 1; *spf != NUL; i++) {
-      copy_option_part((char **)&spf, (char *)fnamebuf, MAXPATHL, ",");
+      copy_option_part(&spf, fnamebuf, MAXPATHL, ",");
       if (i == idx) {
         break;
       }
@@ -5566,7 +5571,7 @@ void spell_add_word(char_u *word, int len, SpellAddType what, int idx, bool undo
     }
 
     // Check that the user isn't editing the .add file somewhere.
-    buf = buflist_findname_exp((char *)fnamebuf);
+    buf = buflist_findname_exp(fnamebuf);
     if (buf != NULL && buf->b_ml.ml_mfp == NULL) {
       buf = NULL;
     }
@@ -5576,7 +5581,7 @@ void spell_add_word(char_u *word, int len, SpellAddType what, int idx, bool undo
       return;
     }
 
-    fname = (char *)fnamebuf;
+    fname = fnamebuf;
   }
 
   if (what == SPELL_ADD_BAD || undo) {
@@ -5584,14 +5589,14 @@ 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) {
           break;  // should never happen
         }
-        if (STRNCMP(word, line, len) == 0
-            && (line[len] == '/' || line[len] < ' ')) {
+        if (strncmp(word, line, (size_t)len) == 0
+            && (line[len] == '/' || (uint8_t)line[len] < ' ')) {
           // Found duplicate word.  Remove it by writing a '#' at
           // the start of the line.  Mixing reading and writing
           // doesn't work for all systems, close the file first.
@@ -5603,7 +5608,7 @@ void spell_add_word(char_u *word, int len, SpellAddType what, int idx, bool undo
           if (fseek(fd, fpos, SEEK_SET) == 0) {
             fputc('#', fd);
             if (undo) {
-              home_replace(NULL, fname, (char *)NameBuff, MAXPATHL, true);
+              home_replace(NULL, fname, NameBuff, MAXPATHL, true);
               smsg(_("Word '%.*s' removed from %s"), len, word, NameBuff);
             }
           }
@@ -5628,7 +5633,7 @@ void spell_add_word(char_u *word, int len, SpellAddType what, int idx, bool undo
       // file.  We may need to create the "spell" directory first.  We
       // already checked the runtime directory is writable in
       // init_spellfile().
-      if (!dir_of_file_exists((char_u *)fname)
+      if (!dir_of_file_exists(fname)
           && (p = (char_u *)path_tail_with_sep(fname)) != (char_u *)fname) {
         int c = *p;
 
@@ -5653,7 +5658,7 @@ void spell_add_word(char_u *word, int len, SpellAddType what, int idx, bool undo
       }
       fclose(fd);
 
-      home_replace(NULL, fname, (char *)NameBuff, MAXPATHL, true);
+      home_replace(NULL, fname, NameBuff, MAXPATHL, true);
       smsg(_("Word '%.*s' added to %s"), len, word, NameBuff);
     }
   }
@@ -5667,7 +5672,7 @@ void spell_add_word(char_u *word, int len, SpellAddType what, int idx, bool undo
       buf_reload(buf, buf->b_orig_mode, false);
     }
 
-    redraw_all_later(SOME_VALID);
+    redraw_all_later(UPD_SOME_VALID);
   }
   xfree(fnamebuf);
 }
@@ -5675,98 +5680,98 @@ void spell_add_word(char_u *word, int len, SpellAddType what, int idx, bool undo
 // Initialize 'spellfile' for the current buffer.
 static void init_spellfile(void)
 {
-  char_u *buf;
+  char *buf;
   int l;
-  char_u *fname;
-  char_u *rtp;
-  char_u *lend;
+  char *fname;
+  char *rtp;
+  char *lend;
   bool aspath = false;
-  char_u *lstart = curbuf->b_s.b_p_spl;
-
-  if (*curwin->w_s->b_p_spl != NUL && !GA_EMPTY(&curwin->w_s->b_langp)) {
-    buf = xmalloc(MAXPATHL);
-
-    // Find the end of the language name.  Exclude the region.  If there
-    // is a path separator remember the start of the tail.
-    for (lend = curwin->w_s->b_p_spl; *lend != NUL
-         && vim_strchr(",._", *lend) == NULL; lend++) {
-      if (vim_ispathsep(*lend)) {
-        aspath = true;
-        lstart = lend + 1;
-      }
+  char *lstart = curbuf->b_s.b_p_spl;
+
+  if (*curwin->w_s->b_p_spl == NUL || GA_EMPTY(&curwin->w_s->b_langp)) {
+    return;
+  }
+
+  buf = xmalloc(MAXPATHL);
+
+  // Find the end of the language name.  Exclude the region.  If there
+  // is a path separator remember the start of the tail.
+  for (lend = curwin->w_s->b_p_spl; *lend != NUL
+       && vim_strchr(",._", (uint8_t)(*lend)) == NULL; lend++) {
+    if (vim_ispathsep(*lend)) {
+      aspath = true;
+      lstart = lend + 1;
     }
+  }
 
-    // Loop over all entries in 'runtimepath'.  Use the first one where we
-    // are allowed to write.
-    rtp = p_rtp;
-    while (*rtp != NUL) {
+  // Loop over all entries in 'runtimepath'.  Use the first one where we
+  // are allowed to write.
+  rtp = p_rtp;
+  while (*rtp != NUL) {
+    if (aspath) {
+      // Use directory of an entry with path, e.g., for
+      // "/dir/lg.utf-8.spl" use "/dir".
+      xstrlcpy(buf, curbuf->b_s.b_p_spl, (size_t)(lstart - curbuf->b_s.b_p_spl));
+    } else {
+      // Copy the path from 'runtimepath' to buf[].
+      copy_option_part(&rtp, buf, MAXPATHL, ",");
+    }
+    if (os_file_is_writable(buf) == 2) {
+      // Use the first language name from 'spelllang' and the
+      // encoding used in the first loaded .spl file.
       if (aspath) {
-        // Use directory of an entry with path, e.g., for
-        // "/dir/lg.utf-8.spl" use "/dir".
-        STRLCPY(buf, curbuf->b_s.b_p_spl,
-                lstart - curbuf->b_s.b_p_spl);
+        xstrlcpy(buf, curbuf->b_s.b_p_spl, (size_t)(lend - curbuf->b_s.b_p_spl + 1));
       } else {
-        // Copy the path from 'runtimepath' to buf[].
-        copy_option_part((char **)&rtp, (char *)buf, MAXPATHL, ",");
-      }
-      if (os_file_is_writable((char *)buf) == 2) {
-        // Use the first language name from 'spelllang' and the
-        // encoding used in the first loaded .spl file.
-        if (aspath) {
-          STRLCPY(buf, curbuf->b_s.b_p_spl,
-                  lend - curbuf->b_s.b_p_spl + 1);
-        } else {
-          // Create the "spell" directory if it doesn't exist yet.
-          l = (int)STRLEN(buf);
-          vim_snprintf((char *)buf + l, MAXPATHL - (size_t)l, "/spell");
-          if (os_file_is_writable((char *)buf) != 2) {
-            os_mkdir((char *)buf, 0755);
-          }
-
-          l = (int)STRLEN(buf);
-          vim_snprintf((char *)buf + l, MAXPATHL - (size_t)l,
-                       "/%.*s", (int)(lend - lstart), lstart);
+        // Create the "spell" directory if it doesn't exist yet.
+        l = (int)strlen(buf);
+        vim_snprintf(buf + l, MAXPATHL - (size_t)l, "/spell");
+        if (os_file_is_writable(buf) != 2) {
+          os_mkdir(buf, 0755);
         }
-        l = (int)STRLEN(buf);
-        fname = LANGP_ENTRY(curwin->w_s->b_langp, 0)
-                ->lp_slang->sl_fname;
-        vim_snprintf((char *)buf + l, MAXPATHL - (size_t)l, ".%s.add",
-                     ((fname != NULL
-                       && strstr(path_tail((char *)fname), ".ascii.") != NULL)
-                      ? "ascii"
-                      : (const char *)spell_enc()));
-        set_option_value("spellfile", 0L, (const char *)buf, OPT_LOCAL);
-        break;
+
+        l = (int)strlen(buf);
+        vim_snprintf(buf + l, MAXPATHL - (size_t)l,
+                     "/%.*s", (int)(lend - lstart), lstart);
       }
-      aspath = false;
+      l = (int)strlen(buf);
+      fname = LANGP_ENTRY(curwin->w_s->b_langp, 0)
+              ->lp_slang->sl_fname;
+      vim_snprintf(buf + l, MAXPATHL - (size_t)l, ".%s.add",
+                   ((fname != NULL
+                     && strstr(path_tail(fname), ".ascii.") != NULL)
+                    ? "ascii"
+                    : (const char *)spell_enc()));
+      set_option_value_give_err("spellfile", 0L, buf, OPT_LOCAL);
+      break;
     }
-
-    xfree(buf);
+    aspath = false;
   }
+
+  xfree(buf);
 }
 
 /// Set the spell character tables from strings in the .spl file.
 ///
 /// @param cnt  length of "flags"
-static void set_spell_charflags(char_u *flags, int cnt, char_u *fol)
+static void set_spell_charflags(const char_u *flags, int cnt, char *fol)
 {
   // We build the new tables here first, so that we can compare with the
   // previous one.
   spelltab_T new_st;
   int i;
-  char_u *p = fol;
+  char *p = fol;
   int c;
 
   clear_spell_chartab(&new_st);
 
-  for (i = 0; i < 128; ++i) {
+  for (i = 0; i < 128; i++) {
     if (i < cnt) {
       new_st.st_isw[i + 128] = (flags[i] & CF_WORD) != 0;
       new_st.st_isu[i + 128] = (flags[i] & CF_UPPER) != 0;
     }
 
     if (*p != NUL) {
-      c = mb_ptr2char_adv((const char_u **)&p);
+      c = mb_ptr2char_adv((const char **)&p);
       new_st.st_fold[i + 128] = (char_u)c;
       if (i + 128 != c && new_st.st_isu[i + 128] && c < 256) {
         new_st.st_upper[c] = (char_u)(i + 128);
@@ -5783,7 +5788,7 @@ static int set_spell_finish(spelltab_T *new_st)
 
   if (did_set_spelltab) {
     // check that it's the same table
-    for (i = 0; i < 256; ++i) {
+    for (i = 0; i < 256; i++) {
       if (spelltab.st_isw[i] != new_st->st_isw[i]
           || spelltab.st_isu[i] != new_st->st_isu[i]
           || spelltab.st_fold[i] != new_st->st_fold[i]
@@ -5815,7 +5820,7 @@ static int write_spell_prefcond(FILE *fd, garray_T *gap, size_t *fwv)
     // <prefcond> : <condlen> <condstr>
     char *p = ((char **)gap->ga_data)[i];
     if (p != NULL) {
-      size_t len = STRLEN(p);
+      size_t len = strlen(p);
       if (fd != NULL) {
         assert(len <= INT_MAX);
         fputc((int)len, fd);
@@ -5832,9 +5837,9 @@ static int write_spell_prefcond(FILE *fd, garray_T *gap, size_t *fwv)
 }
 
 // Use map string "map" for languages "lp".
-static void set_map_str(slang_T *lp, char_u *map)
+static void set_map_str(slang_T *lp, char *map)
 {
-  char_u *p;
+  char *p;
   int headc = 0;
   int c;
   int i;
@@ -5846,7 +5851,7 @@ static void set_map_str(slang_T *lp, char_u *map)
   lp->sl_has_map = true;
 
   // Init the array and hash tables empty.
-  for (i = 0; i < 256; ++i) {
+  for (i = 0; i < 256; i++) {
     lp->sl_map_array[i] = 0;
   }
   hash_init(&lp->sl_map_hash);
@@ -5855,7 +5860,7 @@ static void set_map_str(slang_T *lp, char_u *map)
   // "aaa/bbb/ccc/".  Fill sl_map_array[c] with the character before c and
   // before the same slash.  For characters above 255 sl_map_hash is used.
   for (p = map; *p != NUL;) {
-    c = mb_cptr2char_adv((const char_u **)&p);
+    c = mb_cptr2char_adv((const char **)&p);
     if (c == '/') {
       headc = 0;
     } else {
@@ -5877,10 +5882,10 @@ static void set_map_str(slang_T *lp, char_u *map)
         b[cl] = NUL;
         utf_char2bytes(headc, b + cl + 1);
         b[cl + 1 + headcl] = NUL;
-        hash = hash_hash((char_u *)b);
-        hi = hash_lookup(&lp->sl_map_hash, (const char *)b, STRLEN(b), hash);
+        hash = hash_hash(b);
+        hi = hash_lookup(&lp->sl_map_hash, (const char *)b, strlen(b), hash);
         if (HASHITEM_EMPTY(hi)) {
-          hash_add_item(&lp->sl_map_hash, hi, (char_u *)b, hash);
+          hash_add_item(&lp->sl_map_hash, hi, b, hash);
         } else {
           // This should have been checked when generating the .spl
           // file.