refactor: reduce scope of locals as per the style guide 3 (#22221)

refactor: reduce scope of locals as per the style guide

21 files changed, 147 insertions, 275 deletions

diff --git a/src/nvim/debugger.c b/src/nvim/debugger.c
index dc58d6bf60..3c9a63f5a3 100644
--- a/src/nvim/debugger.c
+++ b/src/nvim/debugger.c
@@ -75,7 +75,6 @@ void do_debug(char *cmd)
   tasave_T typeaheadbuf;
   bool typeahead_saved = false;
   int save_ignore_script = 0;
-  int n;
   char *cmdline = NULL;
   char *p;
   char *tail = NULL;
@@ -146,7 +145,7 @@ void do_debug(char *cmd)
     }
 
     // don't debug any function call, e.g. from an expression mapping
-    n = debug_break_level;
+    int n = debug_break_level;
     debug_break_level = -1;
 
     xfree(cmdline);
diff --git a/src/nvim/diff.c b/src/nvim/diff.c
index 3bdc965146..c5b28822d0 100644
--- a/src/nvim/diff.c
+++ b/src/nvim/diff.c
@@ -2652,8 +2652,7 @@ bool diff_find_change(win_T *wp, linenr_T lnum, int *startp, int *endp)
   bool added = true;
 
   linenr_T off = lnum - dp->df_lnum[idx];
-  int i;
-  for (i = 0; i < DB_COUNT; i++) {
+  for (int i = 0; i < DB_COUNT; i++) {
     if ((curtab->tp_diffbuf[i] != NULL) && (i != idx)) {
       // Skip lines that are not in the other change (filler lines).
       if (off >= dp->df_count[i]) {
diff --git a/src/nvim/drawline.c b/src/nvim/drawline.c
index 6de920b544..e205850314 100644
--- a/src/nvim/drawline.c
+++ b/src/nvim/drawline.c
@@ -1725,9 +1725,7 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool nochange,
         // At start of the line we can have a composing char.
         // Draw it as a space with a composing char.
         if (utf_iscomposing(mb_c)) {
-          int i;
-
-          for (i = MAX_MCO - 1; i > 0; i--) {
+          for (int i = MAX_MCO - 1; i > 0; i--) {
             u8cc[i] = u8cc[i - 1];
           }
           u8cc[0] = mb_c;
@@ -2102,7 +2100,6 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool nochange,
             n_extra = tab_len;
           } else {
             char *p;
-            int i;
             int saved_nextra = n_extra;
 
             if (vcol_off > 0) {
@@ -2131,7 +2128,7 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool nochange,
             p[len] = NUL;
             xfree(p_extra_free);
             p_extra_free = p;
-            for (i = 0; i < tab_len; i++) {
+            for (int i = 0; i < tab_len; i++) {
               if (*p == NUL) {
                 tab_len = i;
                 break;
@@ -2486,7 +2483,6 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool nochange,
            || draw_color_col || line_attr_lowprio || line_attr
            || diff_hlf != (hlf_T)0 || has_virttext)) {
         int rightmost_vcol = 0;
-        int i;
 
         if (wp->w_p_cuc) {
           rightmost_vcol = wp->w_virtcol;
@@ -2494,7 +2490,7 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool nochange,
 
         if (draw_color_col) {
           // determine rightmost colorcolumn to possibly draw
-          for (i = 0; color_cols[i] >= 0; i++) {
+          for (int i = 0; color_cols[i] >= 0; i++) {
             if (rightmost_vcol < color_cols[i]) {
               rightmost_vcol = color_cols[i];
             }
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 1a10f8aebc..3ab704e250 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -1949,7 +1949,6 @@ void set_context_for_expression(expand_T *xp, char *arg, cmdidx_T cmdidx)
   FUNC_ATTR_NONNULL_ALL
 {
   bool got_eq = false;
-  int c;
   char *p;
 
   if (cmdidx == CMD_let || cmdidx == CMD_const) {
@@ -1970,7 +1969,7 @@ void set_context_for_expression(expand_T *xp, char *arg, cmdidx_T cmdidx)
                                         : EXPAND_EXPRESSION;
   }
   while ((xp->xp_pattern = strpbrk(arg, "\"'+-*/%.=!?~|&$([<>,#")) != NULL) {
-    c = (uint8_t)(*xp->xp_pattern);
+    int c = (uint8_t)(*xp->xp_pattern);
     if (c == '&') {
       c = (uint8_t)xp->xp_pattern[1];
       if (c == '&') {
@@ -2310,7 +2309,6 @@ int eval0(char *arg, typval_T *rettv, char **nextcmd, int evaluate)
 /// @return  OK or FAIL.
 int eval1(char **arg, typval_T *rettv, int evaluate)
 {
-  bool result;
   typval_T var2;
 
   // Get the first variable.
@@ -2319,7 +2317,7 @@ int eval1(char **arg, typval_T *rettv, int evaluate)
   }
 
   if ((*arg)[0] == '?') {
-    result = false;
+    bool result = false;
     if (evaluate) {
       bool error = false;
 
@@ -2499,7 +2497,6 @@ static int eval4(char **arg, typval_T *rettv, int evaluate)
   char *p;
   exprtype_T type = EXPR_UNKNOWN;
   int len = 2;
-  bool ic;
 
   // Get the first variable.
   if (eval5(arg, rettv, evaluate) == FAIL) {
@@ -2552,6 +2549,7 @@ static int eval4(char **arg, typval_T *rettv, int evaluate)
 
   // If there is a comparative operator, use it.
   if (type != EXPR_UNKNOWN) {
+    bool ic;
     // extra question mark appended: ignore case
     if (p[len] == '?') {
       ic = true;
@@ -2594,7 +2592,6 @@ static int eval5(char **arg, typval_T *rettv, int evaluate)
 {
   typval_T var2;
   typval_T var3;
-  int op;
   varnumber_T n1, n2;
   float_T f1 = 0, f2 = 0;
   char *p;
@@ -2606,7 +2603,7 @@ static int eval5(char **arg, typval_T *rettv, int evaluate)
 
   // Repeat computing, until no '+', '-' or '.' is following.
   for (;;) {
-    op = (char_u)(**arg);
+    int op = (char_u)(**arg);
     if (op != '+' && op != '-' && op != '.') {
       break;
     }
@@ -3276,7 +3273,6 @@ static int eval_index(char **arg, typval_T *rettv, int evaluate, int verbose)
 {
   bool empty1 = false;
   bool empty2 = false;
-  int n1, n2 = 0;
   ptrdiff_t len = -1;
   int range = false;
   char *key = NULL;
@@ -3373,7 +3369,8 @@ static int eval_index(char **arg, typval_T *rettv, int evaluate, int verbose)
   }
 
   if (evaluate) {
-    n1 = 0;
+    int n2 = 0;
+    int n1 = 0;
     if (!empty1 && rettv->v_type != VAR_DICT && !tv_is_luafunc(rettv)) {
       n1 = (int)tv_get_number(&var1);
       tv_clear(&var1);
@@ -4784,8 +4781,6 @@ void filter_map(typval_T *argvars, typval_T *rettv, int map)
   const char *const arg_errmsg = (map
                                   ? N_("map() argument")
                                   : N_("filter() argument"));
-  int save_did_emsg;
-  int idx = 0;
 
   // Always return the first argument, also on failure.
   tv_copy(&argvars[0], rettv);
@@ -4815,12 +4810,13 @@ void filter_map(typval_T *argvars, typval_T *rettv, int map)
   // message.  Avoid a misleading error message for an empty string that
   // was not passed as argument.
   if (expr->v_type != VAR_UNKNOWN) {
+    int idx = 0;
     typval_T save_val;
     prepare_vimvar(VV_VAL, &save_val);
 
     // We reset "did_emsg" to be able to detect whether an error
     // occurred during evaluation of the expression.
-    save_did_emsg = did_emsg;
+    int save_did_emsg = did_emsg;
     did_emsg = false;
 
     typval_T save_key;
@@ -8064,7 +8060,6 @@ repeat:
 /// @return  an allocated string, NULL for error.
 char *do_string_sub(char *str, char *pat, char *sub, typval_T *expr, const char *flags)
 {
-  int sublen;
   regmatch_T regmatch;
   garray_T ga;
   char *zero_width = NULL;
@@ -8080,6 +8075,7 @@ char *do_string_sub(char *str, char *pat, char *sub, typval_T *expr, const char
   regmatch.rm_ic = p_ic;
   regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
   if (regmatch.regprog != NULL) {
+    int sublen;
     char *tail = str;
     char *end = str + strlen(str);
     while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str))) {
diff --git a/src/nvim/ex_eval.c b/src/nvim/ex_eval.c
index 2c578564bc..1cef99297a 100644
--- a/src/nvim/ex_eval.c
+++ b/src/nvim/ex_eval.c
@@ -1154,7 +1154,6 @@ void do_throw(cstack_T *cstack)
 {
   int inactivate_try = false;
 
-  //
   // Cleanup and deactivate up to the next surrounding try conditional that
   // is not in its finally clause.  Normally, do not deactivate the try
   // conditional itself, so that its ACTIVE flag can be tested below.  But
@@ -1162,7 +1161,7 @@ void do_throw(cstack_T *cstack)
   // deactivate the try conditional, too, as if the conversion had been done,
   // and reset the did_emsg or got_int flag, so this won't happen again at
   // the next surrounding try conditional.
-  //
+
 #ifndef THROW_ON_ERROR_TRUE
   if (did_emsg && !THROW_ON_ERROR) {
     inactivate_try = true;
diff --git a/src/nvim/getchar.c b/src/nvim/getchar.c
index b54ecdb6ab..37840f8875 100644
--- a/src/nvim/getchar.c
+++ b/src/nvim/getchar.c
@@ -661,7 +661,6 @@ static int read_redo(bool init, bool old_redo)
   int c;
   int n;
   char_u buf[MB_MAXBYTES + 1];
-  int i;
 
   if (init) {
     bp = old_redo ? old_redobuff.bh_first.b_next : redobuff.bh_first.b_next;
@@ -682,7 +681,7 @@ static int read_redo(bool init, bool old_redo)
   } else {
     n = 1;
   }
-  for (i = 0;; i++) {
+  for (int i = 0;; i++) {
     if (c == K_SPECIAL) {  // special key or escaped K_SPECIAL
       c = TO_SPECIAL(p[1], p[2]);
       p += 2;
@@ -857,7 +856,6 @@ int ins_typebuf(char *str, int noremap, int offset, bool nottyped, bool silent)
 {
   char_u *s1, *s2;
   int addlen;
-  int i;
   int val;
   int nrm;
 
@@ -947,7 +945,7 @@ int ins_typebuf(char *str, int noremap, int offset, bool nottyped, bool silent)
   } else {
     nrm = noremap;
   }
-  for (i = 0; i < addlen; i++) {
+  for (int i = 0; i < addlen; i++) {
     typebuf.tb_noremap[typebuf.tb_off + i + offset] =
       (uint8_t)((--nrm >= 0) ? val : RM_YES);
   }
@@ -1426,7 +1424,6 @@ int vgetc(void)
   } else {
     int c2;
     int n;
-    int i;
     // number of characters recorded from the last vgetc() call
     static size_t last_vgetc_recorded_len = 0;
 
@@ -1552,7 +1549,7 @@ int vgetc(void)
       if ((n = MB_BYTE2LEN_CHECK(c)) > 1) {
         no_mapping++;
         buf[0] = (char_u)c;
-        for (i = 1; i < n; i++) {
+        for (int i = 1; i < n; i++) {
           buf[i] = (char_u)vgetorpeek(true);
           if (buf[i] == K_SPECIAL) {
             // Must be a K_SPECIAL - KS_SPECIAL - KE_FILLER sequence,
@@ -2904,13 +2901,12 @@ int fix_input_buffer(char *buf, int len)
   }
 
   // Reading from script, need to process special bytes
-  int i;
   char_u *p = (char_u *)buf;
 
   // Two characters are special: NUL and K_SPECIAL.
   // Replace       NUL by K_SPECIAL KS_ZERO    KE_FILLER
   // Replace K_SPECIAL by K_SPECIAL KS_SPECIAL KE_FILLER
-  for (i = len; --i >= 0; p++) {
+  for (int i = len; --i >= 0; p++) {
     if (p[0] == NUL
         || (p[0] == K_SPECIAL
             && (i < 2 || p[1] != KS_EXTRA))) {
diff --git a/src/nvim/grid.c b/src/nvim/grid.c
index 8815ac726a..16ebbfbb90 100644
--- a/src/nvim/grid.c
+++ b/src/nvim/grid.c
@@ -805,7 +805,6 @@ void grid_assign_handle(ScreenGrid *grid)
 /// 'row', 'col' and 'end' are relative to the start of the region.
 void grid_ins_lines(ScreenGrid *grid, int row, int line_count, int end, int col, int width)
 {
-  int i;
   int j;
   unsigned temp;
 
@@ -820,7 +819,7 @@ void grid_ins_lines(ScreenGrid *grid, int row, int line_count, int end, int col,
 
   // Shift line_offset[] line_count down to reflect the inserted lines.
   // Clear the inserted lines.
-  for (i = 0; i < line_count; i++) {
+  for (int i = 0; i < line_count; i++) {
     if (width != grid->cols) {
       // need to copy part of a line
       j = end - 1 - i;
@@ -855,7 +854,6 @@ void grid_ins_lines(ScreenGrid *grid, int row, int line_count, int end, int col,
 void grid_del_lines(ScreenGrid *grid, int row, int line_count, int end, int col, int width)
 {
   int j;
-  int i;
   unsigned temp;
 
   int row_off = 0;
@@ -869,7 +867,7 @@ void grid_del_lines(ScreenGrid *grid, int row, int line_count, int end, int col,
 
   // Now shift line_offset[] line_count up to reflect the deleted lines.
   // Clear the inserted lines.
-  for (i = 0; i < line_count; i++) {
+  for (int i = 0; i < line_count; i++) {
     if (width != grid->cols) {
       // need to copy part of a line
       j = row + i;
diff --git a/src/nvim/help.c b/src/nvim/help.c
index ab4ce4e9ba..5fa48e0cee 100644
--- a/src/nvim/help.c
+++ b/src/nvim/help.c
@@ -47,19 +47,14 @@
 void ex_help(exarg_T *eap)
 {
   char *arg;
-  char *tag;
   FILE *helpfd;          // file descriptor of help file
-  int n;
-  int i;
   win_T *wp;
   int num_matches;
   char **matches;
-  char *p;
   int empty_fnum = 0;
   int alt_fnum = 0;
   buf_T *buf;
   int len;
-  char *lang;
   const bool old_KeyTyped = KeyTyped;
 
   if (eap != NULL) {
@@ -88,13 +83,13 @@ void ex_help(exarg_T *eap)
   }
 
   // remove trailing blanks
-  p = arg + strlen(arg) - 1;
+  char *p = arg + strlen(arg) - 1;
   while (p > arg && ascii_iswhite(*p) && p[-1] != '\\') {
     *p-- = NUL;
   }
 
   // Check for a specified language
-  lang = check_help_lang(arg);
+  char *lang = check_help_lang(arg);
 
   // When no argument given go to the index.
   if (*arg == NUL) {
@@ -102,9 +97,9 @@ void ex_help(exarg_T *eap)
   }
 
   // Check if there is a match for the argument.
-  n = find_help_tags(arg, &num_matches, &matches, eap != NULL && eap->forceit);
+  int n = find_help_tags(arg, &num_matches, &matches, eap != NULL && eap->forceit);
 
-  i = 0;
+  int i = 0;
   if (n != FAIL && lang != NULL) {
     // Find first item with the requested language.
     for (i = 0; i < num_matches; i++) {
@@ -128,7 +123,7 @@ void ex_help(exarg_T *eap)
   }
 
   // The first match (in the requested language) is the best match.
-  tag = xstrdup(matches[i]);
+  char *tag = xstrdup(matches[i]);
   FreeWild(num_matches, matches);
 
   // Re-use an existing help window or open a new one.
@@ -259,11 +254,8 @@ char *check_help_lang(char *arg)
 int help_heuristic(char *matched_string, int offset, int wrong_case)
   FUNC_ATTR_PURE
 {
-  int num_letters;
-  char *p;
-
-  num_letters = 0;
-  for (p = matched_string; *p; p++) {
+  int num_letters = 0;
+  for (char *p = matched_string; *p; p++) {
     if (ASCII_ISALNUM(*p)) {
       num_letters++;
     }
@@ -298,11 +290,8 @@ int help_heuristic(char *matched_string, int offset, int wrong_case)
 /// that has been put after the tagname by find_tags().
 static int help_compare(const void *s1, const void *s2)
 {
-  char *p1;
-  char *p2;
-
-  p1 = *(char **)s1 + strlen(*(char **)s1) + 1;
-  p2 = *(char **)s2 + strlen(*(char **)s2) + 1;
+  char *p1 = *(char **)s1 + strlen(*(char **)s1) + 1;
+  char *p2 = *(char **)s2 + strlen(*(char **)s2) + 1;
 
   // Compare by help heuristic number first.
   int cmp = strcmp(p1, p2);
@@ -320,8 +309,6 @@ static int help_compare(const void *s1, const void *s2)
 /// When "keep_lang" is true try keeping the language of the current buffer.
 int find_help_tags(const char *arg, int *num_matches, char ***matches, bool keep_lang)
 {
-  int i;
-
   // Specific tags that either have a specific replacement or won't go
   // through the generic rules.
   static char *(except_tbl[][2]) = {
@@ -379,7 +366,7 @@ int find_help_tags(const char *arg, int *num_matches, char ***matches, bool keep
     // When the string starting with "expr-" and containing '?' and matches
     // the table, it is taken literally (but ~ is escaped).  Otherwise '?'
     // is recognized as a wildcard.
-    for (i = (int)ARRAY_SIZE(expr_table); --i >= 0;) {
+    for (int i = (int)ARRAY_SIZE(expr_table); --i >= 0;) {
       if (strcmp(arg + 5, expr_table[i]) == 0) {
         for (int si = 0, di = 0;; si++) {
           if (arg[si] == '~') {
@@ -396,7 +383,7 @@ int find_help_tags(const char *arg, int *num_matches, char ***matches, bool keep
   } else {
     // Recognize a few exceptions to the rule.  Some strings that contain
     // '*'are changed to "star", otherwise '*' is recognized as a wildcard.
-    for (i = 0; except_tbl[i][0] != NULL; i++) {
+    for (int i = 0; except_tbl[i][0] != NULL; i++) {
       if (strcmp(arg, except_tbl[i][0]) == 0) {
         STRCPY(d, except_tbl[i][1]);
         break;
diff --git a/src/nvim/keycodes.c b/src/nvim/keycodes.c
index ff1bcffbdb..8114efc10c 100644
--- a/src/nvim/keycodes.c
+++ b/src/nvim/keycodes.c
@@ -637,7 +637,6 @@ int find_special_key(const char **const srcp, const size_t src_len, int *const m
   const bool in_string = flags & FSK_IN_STRING;
   int modifiers;
   int bit;
-  int key;
   uvarnumber_T n;
   int l;
 
@@ -685,6 +684,7 @@ int find_special_key(const char **const srcp, const size_t src_len, int *const m
   }
 
   if (bp <= end && *bp == '>') {  // found matching '>'
+    int key;
     end_of_name = bp + 1;
 
     // Which modifiers are given?
diff --git a/src/nvim/mark.c b/src/nvim/mark.c
index 0a944da2c4..855fcb33ae 100644
--- a/src/nvim/mark.c
+++ b/src/nvim/mark.c
@@ -616,11 +616,8 @@ fmarkv_T mark_view_make(linenr_T topline, pos_T pos)
 /// @return  next mark or NULL if no mark is found.
 fmark_T *getnextmark(pos_T *startpos, int dir, int begin_line)
 {
-  int i;
   fmark_T *result = NULL;
-  pos_T pos;
-
-  pos = *startpos;
+  pos_T pos = *startpos;
 
   if (dir == BACKWARD && begin_line) {
     pos.col = 0;
@@ -628,7 +625,7 @@ fmark_T *getnextmark(pos_T *startpos, int dir, int begin_line)
     pos.col = MAXCOL;
   }
 
-  for (i = 0; i < NMARKS; i++) {
+  for (int i = 0; i < NMARKS; i++) {
     if (curbuf->b_namedm[i].mark.lnum > 0) {
       if (dir == FORWARD) {
         if ((result == NULL || lt(curbuf->b_namedm[i].mark, result->mark))
@@ -685,18 +682,17 @@ static void fname2fnum(xfmark_T *fm)
 void fmarks_check_names(buf_T *buf)
 {
   char *name = buf->b_ffname;
-  int i;
 
   if (buf->b_ffname == NULL) {
     return;
   }
 
-  for (i = 0; i < NGLOBALMARKS; i++) {
+  for (int i = 0; i < NGLOBALMARKS; i++) {
     fmarks_check_one(&namedfm[i], name, buf);
   }
 
   FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
-    for (i = 0; i < wp->w_jumplistlen; i++) {
+    for (int i = 0; i < wp->w_jumplistlen; i++) {
       fmarks_check_one(&wp->w_jumplist[i], name, buf);
     }
   }
@@ -820,7 +816,6 @@ static char *mark_line(pos_T *mp, int lead_len)
 void ex_marks(exarg_T *eap)
 {
   char *arg = eap->arg;
-  int i;
   char *name;
   pos_T *posp, *startp, *endp;
 
@@ -829,10 +824,10 @@ void ex_marks(exarg_T *eap)
   }
 
   show_one_mark('\'', arg, &curwin->w_pcmark, NULL, true);
-  for (i = 0; i < NMARKS; i++) {
+  for (int i = 0; i < NMARKS; i++) {
     show_one_mark(i + 'a', arg, &curbuf->b_namedm[i].mark, NULL, true);
   }
-  for (i = 0; i < NGLOBALMARKS; i++) {
+  for (int i = 0; i < NGLOBALMARKS; i++) {
     if (namedfm[i].fmark.fnum != 0) {
       name = fm_getname(&namedfm[i].fmark, 15);
     } else {
@@ -918,7 +913,6 @@ void ex_delmarks(exarg_T *eap)
 {
   char *p;
   int from, to;
-  int i;
   int lower;
   int digit;
   int n;
@@ -953,7 +947,7 @@ void ex_delmarks(exarg_T *eap)
           from = to = (uint8_t)(*p);
         }
 
-        for (i = from; i <= to; i++) {
+        for (int i = from; i <= to; i++) {
           if (lower) {
             curbuf->b_namedm[i - 'a'].mark.lnum = 0;
           } else {
@@ -997,13 +991,12 @@ void ex_delmarks(exarg_T *eap)
 // print the jumplist
 void ex_jumps(exarg_T *eap)
 {
-  int i;
   char *name;
 
   cleanup_jumplist(curwin, true);
   // Highlight title
   msg_puts_title(_("\n jump line  col file/text"));
-  for (i = 0; i < curwin->w_jumplistlen && !got_int; i++) {
+  for (int i = 0; i < curwin->w_jumplistlen && !got_int; i++) {
     if (curwin->w_jumplist[i].fmark.mark.lnum != 0) {
       name = fm_getname(&curwin->w_jumplist[i].fmark, 16);
 
@@ -1050,13 +1043,12 @@ void ex_clearjumps(exarg_T *eap)
 // print the changelist
 void ex_changes(exarg_T *eap)
 {
-  int i;
   char *name;
 
   // Highlight title
   msg_puts_title(_("\nchange line  col text"));
 
-  for (i = 0; i < curbuf->b_changelistlen && !got_int; i++) {
+  for (int i = 0; i < curbuf->b_changelistlen && !got_int; i++) {
     if (curbuf->b_changelist[i].mark.lnum != 0) {
       msg_putchar('\n');
       if (got_int) {
@@ -1137,7 +1129,6 @@ void mark_adjust_nofold(linenr_T line1, linenr_T line2, linenr_T amount, linenr_
 static void mark_adjust_internal(linenr_T line1, linenr_T line2, linenr_T amount,
                                  linenr_T amount_after, bool adjust_folds, ExtmarkOp op)
 {
-  int i;
   int fnum = curbuf->b_fnum;
   linenr_T *lp;
   static pos_T initpos = { 1, 0, 0 };
@@ -1148,13 +1139,13 @@ static void mark_adjust_internal(linenr_T line1, linenr_T line2, linenr_T amount
 
   if ((cmdmod.cmod_flags & CMOD_LOCKMARKS) == 0) {
     // named marks, lower case and upper case
-    for (i = 0; i < NMARKS; i++) {
+    for (int i = 0; i < NMARKS; i++) {
       ONE_ADJUST(&(curbuf->b_namedm[i].mark.lnum));
       if (namedfm[i].fmark.fnum == fnum) {
         ONE_ADJUST_NODEL(&(namedfm[i].fmark.mark.lnum));
       }
     }
-    for (i = NMARKS; i < NGLOBALMARKS; i++) {
+    for (int i = NMARKS; i < NGLOBALMARKS; i++) {
       if (namedfm[i].fmark.fnum == fnum) {
         ONE_ADJUST_NODEL(&(namedfm[i].fmark.mark.lnum));
       }
@@ -1172,7 +1163,7 @@ static void mark_adjust_internal(linenr_T line1, linenr_T line2, linenr_T amount
     }
 
     // list of change positions
-    for (i = 0; i < curbuf->b_changelistlen; i++) {
+    for (int i = 0; i < curbuf->b_changelistlen; i++) {
       ONE_ADJUST_NODEL(&(curbuf->b_changelist[i].mark.lnum));
     }
 
@@ -1216,7 +1207,7 @@ static void mark_adjust_internal(linenr_T line1, linenr_T line2, linenr_T amount
     if ((cmdmod.cmod_flags & CMOD_LOCKMARKS) == 0) {
       // Marks in the jumplist.  When deleting lines, this may create
       // duplicate marks in the jumplist, they will be removed later.
-      for (i = 0; i < win->w_jumplistlen; i++) {
+      for (int i = 0; i < win->w_jumplistlen; i++) {
         if (win->w_jumplist[i].fmark.fnum == fnum) {
           ONE_ADJUST_NODEL(&(win->w_jumplist[i].fmark.mark.lnum));
         }
@@ -1226,7 +1217,7 @@ static void mark_adjust_internal(linenr_T line1, linenr_T line2, linenr_T amount
     if (win->w_buffer == curbuf) {
       if ((cmdmod.cmod_flags & CMOD_LOCKMARKS) == 0) {
         // marks in the tag stack
-        for (i = 0; i < win->w_tagstacklen; i++) {
+        for (int i = 0; i < win->w_tagstacklen; i++) {
           if (win->w_tagstack[i].fmark.fnum == fnum) {
             ONE_ADJUST_NODEL(&(win->w_tagstack[i].fmark.mark.lnum));
           }
@@ -1308,7 +1299,6 @@ static void mark_adjust_internal(linenr_T line1, linenr_T line2, linenr_T amount
 void mark_col_adjust(linenr_T lnum, colnr_T mincol, linenr_T lnum_amount, long col_amount,
                      int spaces_removed)
 {
-  int i;
   int fnum = curbuf->b_fnum;
   pos_T *posp;
 
@@ -1316,13 +1306,13 @@ void mark_col_adjust(linenr_T lnum, colnr_T mincol, linenr_T lnum_amount, long c
     return;     // nothing to do
   }
   // named marks, lower case and upper case
-  for (i = 0; i < NMARKS; i++) {
+  for (int i = 0; i < NMARKS; i++) {
     COL_ADJUST(&(curbuf->b_namedm[i].mark));
     if (namedfm[i].fmark.fnum == fnum) {
       COL_ADJUST(&(namedfm[i].fmark.mark));
     }
   }
-  for (i = NMARKS; i < NGLOBALMARKS; i++) {
+  for (int i = NMARKS; i < NGLOBALMARKS; i++) {
     if (namedfm[i].fmark.fnum == fnum) {
       COL_ADJUST(&(namedfm[i].fmark.mark));
     }
@@ -1335,7 +1325,7 @@ void mark_col_adjust(linenr_T lnum, colnr_T mincol, linenr_T lnum_amount, long c
   COL_ADJUST(&(curbuf->b_last_change.mark));
 
   // list of change positions
-  for (i = 0; i < curbuf->b_changelistlen; i++) {
+  for (int i = 0; i < curbuf->b_changelistlen; i++) {
     COL_ADJUST(&(curbuf->b_changelist[i].mark));
   }
 
@@ -1355,7 +1345,7 @@ void mark_col_adjust(linenr_T lnum, colnr_T mincol, linenr_T lnum_amount, long c
   // Adjust items in all windows related to the current buffer.
   FOR_ALL_WINDOWS_IN_TAB(win, curtab) {
     // marks in the jumplist
-    for (i = 0; i < win->w_jumplistlen; i++) {
+    for (int i = 0; i < win->w_jumplistlen; i++) {
       if (win->w_jumplist[i].fmark.fnum == fnum) {
         COL_ADJUST(&(win->w_jumplist[i].fmark.mark));
       }
@@ -1363,7 +1353,7 @@ void mark_col_adjust(linenr_T lnum, colnr_T mincol, linenr_T lnum_amount, long c
 
     if (win->w_buffer == curbuf) {
       // marks in the tag stack
-      for (i = 0; i < win->w_tagstacklen; i++) {
+      for (int i = 0; i < win->w_tagstacklen; i++) {
         if (win->w_tagstack[i].fmark.fnum == fnum) {
           COL_ADJUST(&(win->w_tagstack[i].fmark.mark));
         }
@@ -1456,9 +1446,7 @@ void cleanup_jumplist(win_T *wp, bool loadfiles)
 // Copy the jumplist from window "from" to window "to".
 void copy_jumplist(win_T *from, win_T *to)
 {
-  int i;
-
-  for (i = 0; i < from->w_jumplistlen; i++) {
+  for (int i = 0; i < from->w_jumplistlen; i++) {
     to->w_jumplist[i] = from->w_jumplist[i];
     if (from->w_jumplist[i].fname != NULL) {
       to->w_jumplist[i].fname = xstrdup(from->w_jumplist[i].fname);
@@ -1670,9 +1658,7 @@ bool mark_set_local(const char name, buf_T *const buf, const fmark_T fm, const b
 // Free items in the jumplist of window "wp".
 void free_jumplist(win_T *wp)
 {
-  int i;
-
-  for (i = 0; i < wp->w_jumplistlen; i++) {
+  for (int i = 0; i < wp->w_jumplistlen; i++) {
     free_xfmark(wp->w_jumplist[i]);
   }
   wp->w_jumplistlen = 0;
diff --git a/src/nvim/mbyte.c b/src/nvim/mbyte.c
index c2bde53b32..e27bb003e7 100644
--- a/src/nvim/mbyte.c
+++ b/src/nvim/mbyte.c
@@ -847,7 +847,6 @@ int utf_byte2len(int b)
 int utf_ptr2len_len(const char *p, int size)
 {
   int len;
-  int i;
   int m;
 
   len = utf8len_tab[(uint8_t)(*p)];
@@ -859,7 +858,7 @@ int utf_ptr2len_len(const char *p, int size)
   } else {
     m = len;
   }
-  for (i = 1; i < m; i++) {
+  for (int i = 1; i < m; i++) {
     if ((p[i] & 0xc0) != 0x80) {
       return 1;
     }
@@ -1530,7 +1529,6 @@ void show_utf8(void)
   int rlen = 0;
   char *line;
   int clen;
-  int i;
 
   // Get the byte length of the char under the cursor, including composing
   // characters.
@@ -1542,7 +1540,7 @@ void show_utf8(void)
   }
 
   clen = 0;
-  for (i = 0; i < len; i++) {
+  for (int i = 0; i < len; i++) {
     if (clen == 0) {
       // start of (composing) character, get its length
       if (i > 0) {
@@ -2171,9 +2169,7 @@ char *enc_canonize(char *enc)
 /// Returns -1 when not found.
 static int enc_alias_search(const char *name)
 {
-  int i;
-
-  for (i = 0; enc_alias_table[i].name != NULL; i++) {
+  for (int i = 0; enc_alias_table[i].name != NULL; i++) {
     if (strcmp(name, enc_alias_table[i].name) == 0) {
       return enc_alias_table[i].canon;
     }
diff --git a/src/nvim/menu.c b/src/nvim/menu.c
index 8ab515bf0e..4fad926cb0 100644
--- a/src/nvim/menu.c
+++ b/src/nvim/menu.c
@@ -281,7 +281,6 @@ static int add_menu_path(const char *const menu_path, vimmenu_T *menuarg, const
   char *next_name;
   char c;
   char d;
-  int i;
   int pri_idx = 0;
   int old_modes = 0;
   int amenu;
@@ -411,7 +410,7 @@ static int add_menu_path(const char *const menu_path, vimmenu_T *menuarg, const
     p = (call_data == NULL) ? NULL : xstrdup(call_data);
 
     // loop over all modes, may add more than one
-    for (i = 0; i < MENU_MODES; i++) {
+    for (int i = 0; i < MENU_MODES; i++) {
       if (modes & (1 << i)) {
         // free any old menu
         free_menu_string(menu, i);
@@ -617,10 +616,7 @@ static int remove_menu(vimmenu_T **menup, char *name, int modes, bool silent)
 // Free the given menu structure and remove it from the linked list.
 static void free_menu(vimmenu_T **menup)
 {
-  int i;
-  vimmenu_T *menu;
-
-  menu = *menup;
+  vimmenu_T *menu = *menup;
 
   // Don't change *menup until after calling gui_mch_destroy_menu(). The
   // MacOS code needs the original structure to properly delete the menu.
@@ -630,7 +626,7 @@ static void free_menu(vimmenu_T **menup)
   xfree(menu->en_name);
   xfree(menu->en_dname);
   xfree(menu->actext);
-  for (i = 0; i < MENU_MODES; i++) {
+  for (int i = 0; i < MENU_MODES; i++) {
     free_menu_string(menu, i);
   }
   xfree(menu);
@@ -640,9 +636,8 @@ static void free_menu(vimmenu_T **menup)
 static void free_menu_string(vimmenu_T *menu, int idx)
 {
   int count = 0;
-  int i;
 
-  for (i = 0; i < MENU_MODES; i++) {
+  for (int i = 0; i < MENU_MODES; i++) {
     if (menu->strings[i] == menu->strings[idx]) {
       count++;
     }
@@ -662,13 +657,11 @@ static void free_menu_string(vimmenu_T *menu, int idx)
 /// @see menu_get
 static dict_T *menu_get_recursive(const vimmenu_T *menu, int modes)
 {
-  dict_T *dict;
-
   if (!menu || (menu->modes & modes) == 0x0) {
     return NULL;
   }
 
-  dict = tv_dict_alloc();
+  dict_T *dict = tv_dict_alloc();
   tv_dict_add_str(dict, S_LEN("name"), menu->dname);
   tv_dict_add_nr(dict, S_LEN("priority"), (int)menu->priority);
   tv_dict_add_nr(dict, S_LEN("hidden"), menu_is_hidden(menu->dname));
diff --git a/src/nvim/runtime.c b/src/nvim/runtime.c
index 70e1e00623..cff0f886ce 100644
--- a/src/nvim/runtime.c
+++ b/src/nvim/runtime.c
@@ -286,7 +286,6 @@ int do_in_path(char *path, char *name, int flags, DoInRuntimepathCB callback, vo
   char *buf = xmallocz(MAXPATHL);
   {
     char *tail;
-    int i;
     if (p_verbose > 10 && name != NULL) {
       verbose_enter();
       smsg(_("Searching for \"%s\" in \"%s\""), name, path);
@@ -335,7 +334,7 @@ int do_in_path(char *path, char *name, int flags, DoInRuntimepathCB callback, vo
 
           // Expand wildcards, invoke the callback for each match.
           if (gen_expand_wildcards(1, &buf, &num_files, &files, ew_flags) == OK) {
-            for (i = 0; i < num_files; i++) {
+            for (int i = 0; i < num_files; i++) {
               (*callback)(files[i], cookie);
               did_one = true;
               if (!(flags & DIP_ALL)) {
@@ -416,7 +415,6 @@ int do_in_cached_path(char *name, int flags, DoInRuntimepathCB callback, void *c
   char *tail;
   int num_files;
   char **files;
-  int i;
   bool did_one = false;
 
   char buf[MAXPATHL];
@@ -469,7 +467,7 @@ int do_in_cached_path(char *name, int flags, DoInRuntimepathCB callback, void *c
         // Expand wildcards, invoke the callback for each match.
         char *(pat[]) = { buf };
         if (gen_expand_wildcards(1, pat, &num_files, &files, ew_flags) == OK) {
-          for (i = 0; i < num_files; i++) {
+          for (int i = 0; i < num_files; i++) {
             (*callback)(files[i], cookie);
             did_one = true;
             if (!(flags & DIP_ALL)) {
diff --git a/src/nvim/screen.c b/src/nvim/screen.c
index 05da6e0ef1..da9178bdff 100644
--- a/src/nvim/screen.c
+++ b/src/nvim/screen.c
@@ -248,11 +248,8 @@ size_t fill_foldcolumn(char *p, win_T *wp, foldinfo_T foldinfo, linenr_T lnum)
 /// Only works for single-byte characters (e.g., numbers).
 void rl_mirror(char *str)
 {
-  char *p1, *p2;
-  char t;
-
-  for (p1 = str, p2 = str + strlen(str) - 1; p1 < p2; p1++, p2--) {
-    t = *p1;
+  for (char *p1 = str, *p2 = str + strlen(str) - 1; p1 < p2; p1++, p2--) {
+    char t = *p1;
     *p1 = *p2;
     *p2 = t;
   }
@@ -264,9 +261,7 @@ void rl_mirror(char *str)
 /// line of the window right of it.  If not, then it's a vertical separator.
 bool stl_connected(win_T *wp)
 {
-  frame_T *fr;
-
-  fr = wp->w_frame;
+  frame_T *fr = wp->w_frame;
   while (fr->fr_parent != NULL) {
     if (fr->fr_parent->fr_layout == FR_COL) {
       if (fr->fr_next != NULL) {
@@ -437,11 +432,7 @@ bool skip_showmode(void)
 /// @return the length of the message (0 if no message).
 int showmode(void)
 {
-  bool need_clear;
   int length = 0;
-  int do_mode;
-  int attr;
-  int sub_attr;
 
   if (ui_has(kUIMessages) && clear_cmdline) {
     msg_ext_clear(true);
@@ -452,12 +443,13 @@ int showmode(void)
 
   msg_grid_validate();
 
-  do_mode = ((p_smd && msg_silent == 0)
-             && ((State & MODE_TERMINAL)
-                 || (State & MODE_INSERT)
-                 || restart_edit != NUL
-                 || VIsual_active));
+  int do_mode = ((p_smd && msg_silent == 0)
+                 && ((State & MODE_TERMINAL)
+                     || (State & MODE_INSERT)
+                     || restart_edit != NUL
+                     || VIsual_active));
   if (do_mode || reg_recording != 0) {
+    int sub_attr;
     if (skip_showmode()) {
       return 0;  // show mode later
     }
@@ -468,14 +460,14 @@ int showmode(void)
     check_for_delay(false);
 
     // if the cmdline is more than one line high, erase top lines
-    need_clear = clear_cmdline;
+    bool need_clear = clear_cmdline;
     if (clear_cmdline && cmdline_row < Rows - 1) {
       msg_clr_cmdline();  // will reset clear_cmdline
     }
 
     // Position on the last line in the window, column 0
     msg_pos_mode();
-    attr = HL_ATTR(HLF_CM);                     // Highlight mode
+    int attr = HL_ATTR(HLF_CM);                     // Highlight mode
 
     // When the screen is too narrow to show the entire mode message,
     // avoid scrolling and truncate instead.
diff --git a/src/nvim/search.c b/src/nvim/search.c
index 74ae76e3b2..e5a456161f 100644
--- a/src/nvim/search.c
+++ b/src/nvim/search.c
@@ -136,14 +136,12 @@ typedef struct SearchedFile {
 int search_regcomp(char *pat, char **used_pat, int pat_save, int pat_use, int options,
                    regmmatch_T *regmatch)
 {
-  int magic;
-  int i;
-
   rc_did_emsg = false;
-  magic = magic_isset();
+  int magic = magic_isset();
 
   // If no pattern given, use a previously defined pattern.
   if (pat == NULL || *pat == NUL) {
+    int i;
     if (pat_use == RE_LAST) {
       i = last_idx;
     } else {
@@ -557,8 +555,6 @@ int searchit(win_T *win, buf_T *buf, pos_T *pos, pos_T *end_pos, Direction dir,
   lpos_T endpos;
   lpos_T matchpos;
   int loop;
-  pos_T start_pos;
-  int at_first_line;
   int extra_col;
   int start_char_len;
   bool match_ok;
@@ -611,9 +607,9 @@ int searchit(win_T *win, buf_T *buf, pos_T *pos, pos_T *end_pos, Direction dir,
       extra_col = (options & SEARCH_START) ? start_char_len : 0;
     }
 
-    start_pos = *pos;           // remember start pos for detecting no match
+    pos_T start_pos = *pos;           // remember start pos for detecting no match
     found = 0;                  // default: not found
-    at_first_line = true;       // default: start in first line
+    int at_first_line = true;       // default: start in first line
     if (pos->lnum == 0) {       // correct lnum for when starting in line 0
       pos->lnum = 1;
       pos->col = 0;
@@ -1028,7 +1024,6 @@ int do_search(oparg_T *oap, int dirc, int search_delim, char *pat, long count, i
 {
   pos_T pos;                    // position of the last match
   char *searchstr;
-  struct soffset old_off;
   int retval;                   // Return value
   char *p;
   int64_t c;
@@ -1047,7 +1042,7 @@ int do_search(oparg_T *oap, int dirc, int search_delim, char *pat, long count, i
 
   // Save the values for when (options & SEARCH_KEEP) is used.
   // (there is no "if ()" around this because gcc wants them initialized)
-  old_off = spats[0].off;
+  struct soffset old_off = spats[0].off;
 
   pos = curwin->w_cursor;       // start searching at the cursor position
 
@@ -1434,8 +1429,6 @@ end_do_search:
 int search_for_exact_line(buf_T *buf, pos_T *pos, Direction dir, char *pat)
 {
   linenr_T start = 0;
-  char *ptr;
-  char *p;
 
   if (buf->b_ml.ml_line_count == 0) {
     return FAIL;
@@ -1469,8 +1462,8 @@ int search_for_exact_line(buf_T *buf, pos_T *pos, Direction dir, char *pat)
     if (start == 0) {
       start = pos->lnum;
     }
-    ptr = ml_get_buf(buf, pos->lnum, false);
-    p = skipwhite(ptr);
+    char *ptr = ml_get_buf(buf, pos->lnum, false);
+    char *p = skipwhite(ptr);
     pos->col = (colnr_T)(p - ptr);
 
     // when adding lines the matching line may be empty but it is not
@@ -1503,9 +1496,6 @@ int searchc(cmdarg_T *cap, int t_cmd)
   int c = cap->nchar;                   // char to search for
   int dir = cap->arg;                   // true for searching forward
   long count = cap->count1;             // repeat count
-  int col;
-  char *p;
-  int len;
   bool stop = true;
 
   if (c != NUL) {       // normal search: remember args for repeat
@@ -1550,9 +1540,9 @@ int searchc(cmdarg_T *cap, int t_cmd)
     cap->oap->inclusive = true;
   }
 
-  p = get_cursor_line_ptr();
-  col = curwin->w_cursor.col;
-  len = (int)strlen(p);
+  char *p = get_cursor_line_ptr();
+  int col = curwin->w_cursor.col;
+  int len = (int)strlen(p);
 
   while (count--) {
     for (;;) {
@@ -2295,15 +2285,10 @@ int check_linecomment(const char *line)
 /// @param c  char to show match for
 void showmatch(int c)
 {
-  pos_T *lpos, save_cursor;
-  pos_T mpos;
+  pos_T *lpos;
   colnr_T vcol;
   long *so = curwin->w_p_so >= 0 ? &curwin->w_p_so : &p_so;
   long *siso = curwin->w_p_siso >= 0 ? &curwin->w_p_siso : &p_siso;
-  long save_so;
-  long save_siso;
-  int save_state;
-  colnr_T save_dollar_vcol;
   char *p;
 
   // Only show match for chars in the 'matchpairs' option.
@@ -2345,10 +2330,10 @@ void showmatch(int c)
     return;
   }
 
-  mpos = *lpos;  // save the pos, update_screen() may change it
-  save_cursor = curwin->w_cursor;
-  save_so = *so;
-  save_siso = *siso;
+  pos_T mpos = *lpos;  // save the pos, update_screen() may change it
+  pos_T save_cursor = curwin->w_cursor;
+  long save_so = *so;
+  long save_siso = *siso;
   // Handle "$" in 'cpo': If the ')' is typed on top of the "$",
   // stop displaying the "$".
   if (dollar_vcol >= 0 && dollar_vcol == curwin->w_virtcol) {
@@ -2357,8 +2342,8 @@ void showmatch(int c)
   curwin->w_virtcol++;              // do display ')' just before "$"
   update_screen();                  // show the new char first
 
-  save_dollar_vcol = dollar_vcol;
-  save_state = State;
+  colnr_T save_dollar_vcol = dollar_vcol;
+  int save_state = State;
   State = MODE_SHOWMATCH;
   ui_cursor_shape();                // may show different cursor shape
   curwin->w_cursor = mpos;          // move to matching char
@@ -2531,7 +2516,6 @@ int current_search(long count, bool forward)
 static int is_zero_width(char *pattern, int move, pos_T *cur, Direction direction)
 {
   regmmatch_T regmatch;
-  int nmatched = 0;
   int result = -1;
   pos_T pos;
   const int called_emsg_before = called_emsg;
@@ -2558,6 +2542,7 @@ static int is_zero_width(char *pattern, int move, pos_T *cur, Direction directio
   }
   if (searchit(curwin, curbuf, &pos, NULL, direction, pattern, 1,
                SEARCH_KEEP + flag, RE_SEARCH, NULL) != FAIL) {
+    int nmatched = 0;
     // Zero-width pattern should match somewhere, then we can check if
     // start and end are in the same position.
     do {
@@ -2587,9 +2572,7 @@ static int is_zero_width(char *pattern, int move, pos_T *cur, Direction directio
 /// return true if line 'lnum' is empty or has white chars only.
 int linewhite(linenr_T lnum)
 {
-  char *p;
-
-  p = skipwhite(ml_get(lnum));
+  char *p = skipwhite(ml_get(lnum));
   return *p == NUL;
 }
 
@@ -2682,7 +2665,6 @@ static void update_search_stat(int dirc, pos_T *pos, pos_T *cursor_pos, searchst
   static int chgtick = 0;
   static char *lastpat = NULL;
   static buf_T *lbuf = NULL;
-  proftime_T start;
 
   CLEAR_POINTER(stat);
 
@@ -2722,6 +2704,7 @@ static void update_search_stat(int dirc, pos_T *pos, pos_T *cursor_pos, searchst
       && (dirc == 0 || dirc == '/' ? cur < cnt : cur > 0)) {
     cur += dirc == 0 ? 0 : dirc == '/' ? 1 : -1;
   } else {
+    proftime_T start;
     bool done_search = false;
     pos_T endpos = { 0, 0, 0 };
     p_ws = false;
@@ -2788,7 +2771,6 @@ void f_searchcount(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   if (argvars[0].v_type != VAR_UNKNOWN) {
     dict_T *dict;
     dictitem_T *di;
-    listitem_T *li;
     bool error = false;
 
     if (argvars[0].v_type != VAR_DICT || argvars[0].vval.v_dict == NULL) {
@@ -2834,7 +2816,7 @@ void f_searchcount(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
         semsg(_(e_invarg2), "List format should be [lnum, col, off]");
         return;
       }
-      li = tv_list_find(di->di_tv.vval.v_list, 0L);
+      listitem_T *li = tv_list_find(di->di_tv.vval.v_list, 0L);
       if (li != NULL) {
         pos.lnum = (linenr_T)tv_get_number_chk(TV_LIST_ITEM_TV(li), &error);
         if (error) {
@@ -4156,8 +4138,6 @@ static void show_pat_in_path(char *line, int type, bool did_show, int action, FI
                              linenr_T *lnum, long count)
   FUNC_ATTR_NONNULL_ARG(1, 6)
 {
-  char *p;
-
   if (did_show) {
     msg_putchar('\n');          // cursor below last one
   } else if (!msg_silent) {
@@ -4167,7 +4147,7 @@ static void show_pat_in_path(char *line, int type, bool did_show, int action, FI
     return;
   }
   for (;;) {
-    p = line + strlen(line) - 1;
+    char *p = line + strlen(line) - 1;
     if (fp != NULL) {
       // We used fgets(), so get rid of newline at end
       if (p >= line && *p == '\n') {
diff --git a/src/nvim/spellfile.c b/src/nvim/spellfile.c
index 22a8587f66..e9dd0a4d5e 100644
--- a/src/nvim/spellfile.c
+++ b/src/nvim/spellfile.c
@@ -897,7 +897,6 @@ void suggest_load_files(void)
   char *dotp;
   FILE *fd;
   char buf[MAXWLEN];
-  int i;
   time_t timestamp;
   int wcount;
   int wordnr;
@@ -925,7 +924,7 @@ void suggest_load_files(void)
       }
 
       // <SUGHEADER>: <fileID> <versionnr> <timestamp>
-      for (i = 0; i < VIMSUGMAGICL; i++) {
+      for (int i = 0; i < VIMSUGMAGICL; i++) {
         buf[i] = (char)getc(fd);                              // <fileID>
       }
       if (strncmp(buf, VIMSUGMAGIC, VIMSUGMAGICL) != 0) {
@@ -1734,7 +1733,6 @@ static idx_T read_tree_node(FILE *fd, char_u *byts, idx_T *idxs, int maxidx, idx
                             bool prefixtree, int maxprefcondnr)
 {
   int len;
-  int i;
   int n;
   idx_T idx = startidx;
   int c2;
@@ -1751,7 +1749,7 @@ 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 (int i = 1; i <= len; i++) {
     int c = getc(fd);                                       // <byte>
     if (c < 0) {
       return SP_TRUNCERROR;
@@ -1814,7 +1812,7 @@ 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 (int i = 1; i <= len; i++) {
     if (byts[startidx + i] != 0) {
       if (idxs[startidx + i] & SHARED_MASK) {
         idxs[startidx + i] &= ~SHARED_MASK;
@@ -2673,9 +2671,7 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char *fname)
                  && sofoto == NULL) {
         sofoto = getroom_save(spin, items[1]);
       } else if (strcmp(items[0], "COMMON") == 0) {
-        int i;
-
-        for (i = 1; i < itemcnt; i++) {
+        for (int i = 1; i < itemcnt; i++) {
           if (HASHITEM_EMPTY(hash_find(&spin->si_commonwords, (char *)items[i]))) {
             p = xstrdup(items[i]);
             hash_add(&spin->si_commonwords, p);
@@ -3954,10 +3950,9 @@ static int tree_add_word(spellinfo_T *spin, const char_u *word, wordnode_T *root
   wordnode_T *np;
   wordnode_T *copyp, **copyprev;
   wordnode_T **prev = NULL;
-  int i;
 
   // Add each byte of the word to the tree, including the NUL at the end.
-  for (i = 0;; i++) {
+  for (int 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).
@@ -5737,13 +5732,12 @@ 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 *p = fol;
   int c;
 
   clear_spell_chartab(&new_st);
 
-  for (i = 0; i < 128; i++) {
+  for (int 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;
@@ -5818,7 +5812,6 @@ static void set_map_str(slang_T *lp, char *map)
 {
   char *p;
   int headc = 0;
-  int i;
 
   if (*map == NUL) {
     lp->sl_has_map = false;
@@ -5827,7 +5820,7 @@ static void set_map_str(slang_T *lp, char *map)
   lp->sl_has_map = true;
 
   // Init the array and hash tables empty.
-  for (i = 0; i < 256; i++) {
+  for (int i = 0; i < 256; i++) {
     lp->sl_map_array[i] = 0;
   }
   hash_init(&lp->sl_map_hash);
diff --git a/src/nvim/spellsuggest.c b/src/nvim/spellsuggest.c
index 66829c60c9..d176a65228 100644
--- a/src/nvim/spellsuggest.c
+++ b/src/nvim/spellsuggest.c
@@ -2491,7 +2491,6 @@ static void score_comp_sal(suginfo_T *su)
 {
   langp_T *lp;
   char badsound[MAXWLEN];
-  int i;
   suggest_T *stp;
   suggest_T *sstp;
   int score;
@@ -2505,7 +2504,7 @@ static void score_comp_sal(suginfo_T *su)
       // soundfold the bad word
       spell_soundfold(lp->lp_slang, su->su_fbadword, true, badsound);
 
-      for (i = 0; i < su->su_ga.ga_len; i++) {
+      for (int i = 0; i < su->su_ga.ga_len; i++) {
         stp = &SUG(su->su_ga, i);
 
         // Case-fold the suggested word, sound-fold it and compute the
diff --git a/src/nvim/statusline.c b/src/nvim/statusline.c
index 6e0dc2e8f7..6414b2bb74 100644
--- a/src/nvim/statusline.c
+++ b/src/nvim/statusline.c
@@ -260,23 +260,17 @@ static void win_redr_custom(win_T *wp, bool draw_winbar, bool draw_ruler)
 {
   static bool entered = false;
   int attr;
-  int curattr;
   int row;
   int col = 0;
   int maxwidth;
-  int width;
   int n;
-  int len;
   int fillchar;
   char buf[MAXPATHL];
   char *stl;
-  char *p;
   char *opt_name;
   int opt_scope = 0;
   stl_hlrec_t *hltab;
   StlClickRecord *tabtab;
-  win_T *ewp;
-  int p_crb_save;
   bool is_stl_global = global_stl_height() > 0;
 
   ScreenGrid *grid = &default_grid;
@@ -369,22 +363,22 @@ static void win_redr_custom(win_T *wp, bool draw_winbar, bool draw_ruler)
 
   // Temporarily reset 'cursorbind', we don't want a side effect from moving
   // the cursor away and back.
-  ewp = wp == NULL ? curwin : wp;
-  p_crb_save = ewp->w_p_crb;
+  win_T *ewp = wp == NULL ? curwin : wp;
+  int p_crb_save = ewp->w_p_crb;
   ewp->w_p_crb = false;
 
   // Make a copy, because the statusline may include a function call that
   // might change the option value and free the memory.
   stl = xstrdup(stl);
-  width = build_stl_str_hl(ewp, buf, sizeof(buf), stl, opt_name, opt_scope,
-                           fillchar, maxwidth, &hltab, &tabtab, NULL);
+  int width = build_stl_str_hl(ewp, buf, sizeof(buf), stl, opt_name, opt_scope,
+                               fillchar, maxwidth, &hltab, &tabtab, NULL);
 
   xfree(stl);
   ewp->w_p_crb = p_crb_save;
 
   // Make all characters printable.
-  p = transstr(buf, true);
-  len = (int)xstrlcpy(buf, p, sizeof(buf));
+  char *p = transstr(buf, true);
+  int len = (int)xstrlcpy(buf, p, sizeof(buf));
   len = (size_t)len < sizeof(buf) ? len : (int)sizeof(buf) - 1;
   xfree(p);
 
@@ -398,7 +392,7 @@ static void win_redr_custom(win_T *wp, bool draw_winbar, bool draw_ruler)
   // Draw each snippet with the specified highlighting.
   grid_puts_line_start(grid, row);
 
-  curattr = attr;
+  int curattr = attr;
   p = buf;
   for (n = 0; hltab[n].start != NULL; n++) {
     int textlen = (int)(hltab[n].start - p);
@@ -709,21 +703,9 @@ static void ui_ext_tabline_update(void)
 /// Draw the tab pages line at the top of the Vim window.
 void draw_tabline(void)
 {
-  int tabcount = 0;
-  int tabwidth = 0;
-  int col = 0;
-  int scol = 0;
-  int attr;
   win_T *wp;
-  win_T *cwp;
-  int wincount;
-  int modified;
-  int c;
-  int len;
   int attr_nosel = HL_ATTR(HLF_TP);
   int attr_fill = HL_ATTR(HLF_TPF);
-  char *p;
-  int room;
   int use_sep_chars = (t_colors < 8);
 
   if (default_grid.chars == NULL) {
@@ -748,6 +730,14 @@ void draw_tabline(void)
   if (*p_tal != NUL) {
     win_redr_custom(NULL, false, false);
   } else {
+    int tabcount = 0;
+    int tabwidth = 0;
+    int col = 0;
+    win_T *cwp;
+    int wincount;
+    int c;
+    int len;
+    char *p;
     FOR_ALL_TABS(tp) {
       tabcount++;
     }
@@ -760,7 +750,7 @@ void draw_tabline(void)
       tabwidth = 6;
     }
 
-    attr = attr_nosel;
+    int attr = attr_nosel;
     tabcount = 0;
 
     FOR_ALL_TABS(tp) {
@@ -768,7 +758,7 @@ void draw_tabline(void)
         break;
       }
 
-      scol = col;
+      int scol = col;
 
       if (tp == curtab) {
         cwp = curwin;
@@ -791,7 +781,7 @@ void draw_tabline(void)
 
       grid_putchar(&default_grid, ' ', 0, col++, attr);
 
-      modified = false;
+      int modified = false;
 
       for (wincount = 0; wp != NULL; wp = wp->w_next, wincount++) {
         if (bufIsChanged(wp->w_buffer)) {
@@ -816,7 +806,7 @@ void draw_tabline(void)
         grid_putchar(&default_grid, ' ', 0, col++, attr);
       }
 
-      room = scol - col + tabwidth - 1;
+      int room = scol - col + tabwidth - 1;
       if (room > 0) {
         // Get buffer name in NameBuff[]
         get_trans_bufname(cwp->w_buffer);
diff --git a/src/nvim/syntax.c b/src/nvim/syntax.c
index 49b63ad324..d4161b9ca2 100644
--- a/src/nvim/syntax.c
+++ b/src/nvim/syntax.c
@@ -1218,7 +1218,6 @@ static synstate_T *store_current_state(void)
 // Copy a state stack from "from" in b_sst_array[] to current_state;
 static void load_current_state(synstate_T *from)
 {
-  int i;
   bufstate_T *bp;
 
   clear_current_state();
@@ -1231,7 +1230,7 @@ static void load_current_state(synstate_T *from)
     } else {
       bp = from->sst_union.sst_stack;
     }
-    for (i = 0; i < from->sst_stacksize; i++) {
+    for (int i = 0; i < from->sst_stacksize; i++) {
       CUR_STATE(i).si_idx = bp[i].bs_idx;
       CUR_STATE(i).si_flags = bp[i].bs_flags;
       CUR_STATE(i).si_seqnr = bp[i].bs_seqnr;
@@ -3441,9 +3440,7 @@ static void syn_list_one(const int id, const bool syncing, const bool link_only)
 
 static void syn_list_flags(struct name_list *nlist, int flags, int attr)
 {
-  int i;
-
-  for (i = 0; nlist[i].flag != 0; i++) {
+  for (int i = 0; nlist[i].flag != 0; i++) {
     if (flags & nlist[i].flag) {
       msg_puts_attr(nlist[i].name, attr);
       msg_putchar(' ');
@@ -4736,17 +4733,15 @@ static void init_syn_patterns(void)
 /// @return  a pointer to the next argument, or NULL in case of an error.
 static char *get_syn_pattern(char *arg, synpat_T *ci)
 {
-  char *end;
   int *p;
   int idx;
-  char *cpo_save;
 
   // need at least three chars
   if (arg == NULL || arg[0] == NUL || arg[1] == NUL || arg[2] == NUL) {
     return NULL;
   }
 
-  end = skip_regexp(arg + 1, *arg, true);
+  char *end = skip_regexp(arg + 1, *arg, true);
   if (*end != *arg) {                       // end delimiter not found
     semsg(_("E401: Pattern delimiter not found: %s"), arg);
     return NULL;
@@ -4755,7 +4750,7 @@ static char *get_syn_pattern(char *arg, synpat_T *ci)
   ci->sp_pattern = xstrnsave(arg + 1, (size_t)(end - arg) - 1);
 
   // Make 'cpoptions' empty, to avoid the 'l' flag
-  cpo_save = p_cpo;
+  char *cpo_save = p_cpo;
   p_cpo = empty_option;
   ci->sp_prog = vim_regcomp(ci->sp_pattern, RE_MAGIC);
   p_cpo = cpo_save;
@@ -5145,7 +5140,6 @@ static int in_id_list(stateitem_T *cur_si, int16_t *list, struct sp_syn *ssp, in
 {
   int retval;
   int16_t *scl_list;
-  int16_t item;
   int16_t id = ssp->id;
   static int depth = 0;
   int r;
@@ -5181,7 +5175,7 @@ static int in_id_list(stateitem_T *cur_si, int16_t *list, struct sp_syn *ssp, in
   // If the first item is "ALLBUT", return true if "id" is NOT in the
   // contains list.  We also require that "id" is at the same ":syn include"
   // level as the list.
-  item = *list;
+  int16_t item = *list;
   if (item >= SYNID_ALLBUT && item < SYNID_CLUSTER) {
     if (item < SYNID_TOP) {
       // ALL or ALLBUT: accept all groups in the same file
@@ -5291,9 +5285,6 @@ void ex_syntax(exarg_T *eap)
 
 void ex_ownsyntax(exarg_T *eap)
 {
-  char *old_value;
-  char *new_value;
-
   if (curwin->w_s == &curwin->w_buffer->b_s) {
     curwin->w_s = xcalloc(1, sizeof(synblock_T));
     hash_init(&curwin->w_s->b_keywtab);
@@ -5309,7 +5300,7 @@ void ex_ownsyntax(exarg_T *eap)
   }
 
   // Save value of b:current_syntax.
-  old_value = get_var_value("b:current_syntax");
+  char *old_value = get_var_value("b:current_syntax");
   if (old_value != NULL) {
     old_value = xstrdup(old_value);
   }
@@ -5318,7 +5309,7 @@ void ex_ownsyntax(exarg_T *eap)
   apply_autocmds(EVENT_SYNTAX, eap->arg, curbuf->b_fname, true, curbuf);
 
   // Move value of b:current_syntax to w:current_syntax.
-  new_value = get_var_value("b:current_syntax");
+  char *new_value = get_var_value("b:current_syntax");
   if (new_value != NULL) {
     set_internal_string_var("w:current_syntax", new_value);
   }
@@ -5483,10 +5474,9 @@ int get_syntax_info(int *seqnrp)
 int syn_get_concealed_id(win_T *wp, linenr_T lnum, colnr_T col)
 {
   int seqnr;
-  int syntax_flags;
 
   (void)syn_get_id(wp, lnum, col, false, NULL, false);
-  syntax_flags = get_syntax_info(&seqnr);
+  int syntax_flags = get_syntax_info(&seqnr);
 
   if (syntax_flags & HL_CONCEAL) {
     return seqnr;
diff --git a/src/nvim/tag.c b/src/nvim/tag.c
index 4fecbeebc3..774157831d 100644
--- a/src/nvim/tag.c
+++ b/src/nvim/tag.c
@@ -795,7 +795,6 @@ static void print_tag_list(int new_tag, int use_tagstack, int num_matches, char
 {
   taggy_T *tagstack = curwin->w_tagstack;
   int tagstackidx = curwin->w_tagstackidx;
-  int i;
   char *p;
   char *command_end;
   tagptrs_T tagp;
@@ -821,7 +820,7 @@ static void print_tag_list(int new_tag, int use_tagstack, int num_matches, char
   taglen_advance(taglen);
   msg_puts_attr(_("file\n"), HL_ATTR(HLF_T));
 
-  for (i = 0; i < num_matches && !got_int; i++) {
+  for (int i = 0; i < num_matches && !got_int; i++) {
     parse_match(matches[i], &tagp);
     if (!new_tag && (
                      (g_do_tagpreview != 0
@@ -980,7 +979,6 @@ static void print_tag_list(int new_tag, int use_tagstack, int num_matches, char
 static int add_llist_tags(char *tag, int num_matches, char **matches)
 {
   char tag_name[128 + 1];
-  int i;
   char *p;
   tagptrs_T tagp;
 
@@ -988,7 +986,7 @@ static int add_llist_tags(char *tag, int num_matches, char **matches)
   char *cmd = xmalloc(CMDBUFFSIZE + 1);
   list_T *list = tv_list_alloc(0);
 
-  for (i = 0; i < num_matches; i++) {
+  for (int i = 0; i < num_matches; i++) {
     dict_T *dict;
 
     parse_match(matches[i], &tagp);
@@ -1119,7 +1117,6 @@ static void taglen_advance(int l)
 // Print the tag stack
 void do_tags(exarg_T *eap)
 {
-  int i;
   char *name;
   taggy_T *tagstack = curwin->w_tagstack;
   int tagstackidx = curwin->w_tagstackidx;
@@ -1127,7 +1124,7 @@ void do_tags(exarg_T *eap)
 
   // Highlight title
   msg_puts_title(_("\n  # TO tag         FROM line  in file/text"));
-  for (i = 0; i < tagstacklen; i++) {
+  for (int i = 0; i < tagstacklen; i++) {
     if (tagstack[i].tagname != NULL) {
       name = fm_getname(&(tagstack[i].fmark), 30);
       if (name == NULL) {           // file name not available
@@ -1731,8 +1728,6 @@ static tagmatch_status_T findtags_parse_line(findtags_state_T *st, tagptrs_T *ta
   // For "normal" tags: Do a quick check if the tag matches.
   // This speeds up tag searching a lot!
   if (st->orgpat->headlen) {
-    int i;
-    int tagcmp;
     CLEAR_FIELD(*tagpp);
     tagpp->tagname = st->lbuf;
     tagpp->tagname_end = vim_strchr(st->lbuf, TAB);
@@ -1754,8 +1749,9 @@ static tagmatch_status_T findtags_parse_line(findtags_state_T *st, tagptrs_T *ta
     }
 
     if (st->state == TS_BINARY) {
+      int tagcmp;
       // Simplistic check for unsorted tags file.
-      i = (int)tagpp->tagname[0];
+      int i = (int)tagpp->tagname[0];
       if (margs->sortic) {
         i = TOUPPER_ASC(tagpp->tagname[0]);
       }
@@ -2245,7 +2241,6 @@ static int findtags_copy_matches(findtags_state_T *st, char ***matchesp)
   const bool name_only = (st->flags & TAG_NAMES);
   char **matches;
   int mtt;
-  int i;
   char *mfp;
   char *p;
 
@@ -2256,7 +2251,7 @@ static int findtags_copy_matches(findtags_state_T *st, char ***matchesp)
   }
   st->match_count = 0;
   for (mtt = 0; mtt < MT_COUNT; mtt++) {
-    for (i = 0; i < st->ga_match[mtt].ga_len; i++) {
+    for (int i = 0; i < st->ga_match[mtt].ga_len; i++) {
       mfp = ((char **)(st->ga_match[mtt].ga_data))[i];
       if (matches == NULL) {
         xfree(mfp);
@@ -2731,7 +2726,6 @@ static int parse_match(char *lbuf, tagptrs_T *tagp)
   // Try to find a kind field: "kind:<kind>" or just "<kind>"
   p = tagp->command;
   if (find_extra(&p) == OK) {
-    char *pc;
     tagp->command_end = p;
     if (p > tagp->command && p[-1] == '|') {
       tagp->command_end = p - 1;  // drop trailing bar
@@ -2752,7 +2746,7 @@ static int parse_match(char *lbuf, tagptrs_T *tagp)
           break;
         }
 
-        pc = vim_strchr(p, ':');
+        char *pc = vim_strchr(p, ':');
         pt = vim_strchr(p, '\t');
         if (pc == NULL || (pt != NULL && pc > pt)) {
           tagp->tagkind = p;
@@ -3435,15 +3429,12 @@ static void get_tag_details(taggy_T *tag, dict_T *retdict)
 // 'retdict'.
 void get_tagstack(win_T *wp, dict_T *retdict)
 {
-  list_T *l;
-  int i;
-
   tv_dict_add_nr(retdict, S_LEN("length"), wp->w_tagstacklen);
   tv_dict_add_nr(retdict, S_LEN("curidx"), wp->w_tagstackidx + 1);
-  l = tv_list_alloc(2);
+  list_T *l = tv_list_alloc(2);
   tv_dict_add_list(retdict, S_LEN("items"), l);
 
-  for (i = 0; i < wp->w_tagstacklen; i++) {
+  for (int i = 0; i < wp->w_tagstacklen; i++) {
     dict_T *d = tv_dict_alloc();
     tv_list_append_dict(l, d);
     get_tag_details(&wp->w_tagstack[i], d);
diff --git a/src/nvim/textformat.c b/src/nvim/textformat.c
index 69cc0e046b..05e57e4b8f 100644
--- a/src/nvim/textformat.c
+++ b/src/nvim/textformat.c
@@ -633,19 +633,16 @@ static bool paragraph_start(linenr_T lnum)
 /// @param prev_line   may start in previous line
 void auto_format(bool trailblank, bool prev_line)
 {
-  pos_T pos;
   colnr_T len;
-  char *old;
   char *new, *pnew;
-  int wasatend;
   int cc;
 
   if (!has_format_option(FO_AUTO)) {
     return;
   }
 
-  pos = curwin->w_cursor;
-  old = get_cursor_line_ptr();
+  pos_T pos = curwin->w_cursor;
+  char *old = get_cursor_line_ptr();
 
   // may remove added space
   check_auto_format(false);
@@ -655,7 +652,7 @@ void auto_format(bool trailblank, bool prev_line)
   // in 'formatoptions' and there is a single character before the cursor.
   // Otherwise the line would be broken and when typing another non-white
   // next they are not joined back together.
-  wasatend = (pos.col == (colnr_T)strlen(old));
+  int wasatend = (pos.col == (colnr_T)strlen(old));
   if (*old != NUL && !trailblank && wasatend) {
     dec_cursor();
     cc = gchar_cursor();
@@ -733,18 +730,16 @@ void auto_format(bool trailblank, bool prev_line)
 /// @param end_insert  true when ending Insert mode
 void check_auto_format(bool end_insert)
 {
-  int c = ' ';
-  int cc;
-
   if (!did_add_space) {
     return;
   }
 
-  cc = gchar_cursor();
+  int cc = gchar_cursor();
   if (!WHITECHAR(cc)) {
     // Somehow the space was removed already.
     did_add_space = false;
   } else {
+    int c = ' ';
     if (!end_insert) {
       inc_cursor();
       c = gchar_cursor();
@@ -886,7 +881,6 @@ void op_formatexpr(oparg_T *oap)
 int fex_format(linenr_T lnum, long count, int c)
 {
   int use_sandbox = was_set_insecurely(curwin, "formatexpr", OPT_LOCAL);
-  int r;
 
   // Set v:lnum to the first line number and v:count to the number of lines.
   // Set v:char to the character to be inserted (can be NUL).
@@ -900,7 +894,7 @@ int fex_format(linenr_T lnum, long count, int c)
   if (use_sandbox) {
     sandbox++;
   }
-  r = (int)eval_to_number(fex);
+  int r = (int)eval_to_number(fex);
   if (use_sandbox) {
     sandbox--;
   }