diff --git a/src/nvim/charset.c b/src/nvim/charset.c
index 86d6acc60b..6fb5ebf3e4 100644
--- a/src/nvim/charset.c
+++ b/src/nvim/charset.c
@@ -390,19 +390,13 @@ char_u *transstr(char_u *s) FUNC_ATTR_NONNULL_RET
   return res;
 }
 
-/// Convert the string "str[orglen]" to do ignore-case comparing.  Uses the
-/// current locale.
+/// Convert the string "str[orglen]" to do ignore-case comparing.
+/// Use the current locale.
 ///
-/// When "buf" is NULL returns an allocated string (NULL for out-of-memory).
-/// Otherwise puts the result in "buf[buflen]".
-///
-/// @param str
-/// @param orglen
-/// @param buf
-/// @param buflen
-///
-/// @return converted string.
+/// When "buf" is NULL, return an allocated string.
+/// Otherwise, put the result in buf, limited by buflen, and return buf.
 char_u* str_foldcase(char_u *str, int orglen, char_u *buf, int buflen)
+  FUNC_ATTR_NONNULL_RET
 {
   garray_T ga;
   int i;
diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index b942f69f61..ae8ec4637f 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -3265,6 +3265,7 @@ addstar (
     int len,
     int context                    /* EXPAND_FILES etc. */
 )
+  FUNC_ATTR_NONNULL_RET
 {
   char_u      *retval;
   int i, j;
@@ -3343,35 +3344,33 @@ addstar (
     }
   } else {
     retval = xmalloc(len + 4);
-    if (retval != NULL) {
-      STRLCPY(retval, fname, len + 1);
+    STRLCPY(retval, fname, len + 1);
 
-      /*
-       * Don't add a star to *, ~, ~user, $var or `cmd`.
-       * * would become **, which walks the whole tree.
-       * ~ would be at the start of the file name, but not the tail.
-       * $ could be anywhere in the tail.
-       * ` could be anywhere in the file name.
-       * When the name ends in '$' don't add a star, remove the '$'.
-       */
-      tail = path_tail(retval);
-      ends_in_star = (len > 0 && retval[len - 1] == '*');
+    /*
+     * Don't add a star to *, ~, ~user, $var or `cmd`.
+     * * would become **, which walks the whole tree.
+     * ~ would be at the start of the file name, but not the tail.
+     * $ could be anywhere in the tail.
+     * ` could be anywhere in the file name.
+     * When the name ends in '$' don't add a star, remove the '$'.
+     */
+    tail = path_tail(retval);
+    ends_in_star = (len > 0 && retval[len - 1] == '*');
 #ifndef BACKSLASH_IN_FILENAME
-      for (i = len - 2; i >= 0; --i) {
-        if (retval[i] != '\\')
-          break;
-        ends_in_star = !ends_in_star;
-      }
-#endif
-      if ((*retval != '~' || tail != retval)
-          && !ends_in_star
-          && vim_strchr(tail, '$') == NULL
-          && vim_strchr(retval, '`') == NULL)
-        retval[len++] = '*';
-      else if (len > 0 && retval[len - 1] == '$')
-        --len;
-      retval[len] = NUL;
+    for (i = len - 2; i >= 0; --i) {
+      if (retval[i] != '\\')
+        break;
+      ends_in_star = !ends_in_star;
     }
+#endif
+    if ((*retval != '~' || tail != retval)
+        && !ends_in_star
+        && vim_strchr(tail, '$') == NULL
+        && vim_strchr(retval, '`') == NULL)
+      retval[len++] = '*';
+    else if (len > 0 && retval[len - 1] == '$')
+      --len;
+    retval[len] = NUL;
   }
   return retval;
 }
diff --git a/src/nvim/fileio.c b/src/nvim/fileio.c
index 370584b095..c2f137b88e 100644
--- a/src/nvim/fileio.c
+++ b/src/nvim/fileio.c
@@ -28,6 +28,7 @@
 #include "nvim/ex_docmd.h"
 #include "nvim/ex_eval.h"
 #include "nvim/fold.h"
+#include "nvim/func_attr.h"
 #include "nvim/getchar.h"
 #include "nvim/hashtab.h"
 #include "nvim/iconv.h"
@@ -2106,6 +2107,7 @@ void set_forced_fenc(exarg_T *eap)
  * When *pp is not set to NULL, the result is in allocated memory.
  */
 static char_u *next_fenc(char_u **pp)
+  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_NONNULL_RET
 {
   char_u      *p;
   char_u      *r;