--- a/src/os_vms_conf.h
+++ b/src/os_vms_conf.h
@@ -1,100 +1,102 @@
-/* os_vms_conf.h.  Replaces auto/config.h for VMS */
+/*
+ * os_vms_conf.h.  Replaces auto/config.h for VMS
+ */
 
-#define CASE_INSENSITIVE_FILENAME   /* Open VMS is case insensitive */
-#define SPACE_IN_FILENAME	    /* There could be space between user and passwd */
-#define FNAME_ILLEGAL "|*#?%"       /* Illegal characters in a file name */
-#define BINARY_FILE_IO		    /* Use binary fileio */
+#define CASE_INSENSITIVE_FILENAME   // Open VMS is case insensitive
+#define SPACE_IN_FILENAME	    // There could be space between user and passwd
+#define FNAME_ILLEGAL "|*#?%"       // Illegal characters in a file name
+#define BINARY_FILE_IO		    // Use binary fileio
 #define USE_GETCWD
 #define USE_SYSTEM
 #define XPMATTRIBUTES_TYPE XpmAttributes
 
-/* Define when terminfo support found */
+// Define when terminfo support found
 #undef TERMINFO
 
-/* Define when termcap.h contains ospeed */
-/* #define HAVE_OSPEED */
+// Define when termcap.h contains ospeed
+// #define HAVE_OSPEED
 
-/* Define when termcap.h contains UP, BC and PC */
-/* #define HAVE_UP_BC_PC */
+// Define when termcap.h contains UP, BC and PC
+// #define HAVE_UP_BC_PC
 
-/* Define when termcap.h defines outfuntype */
-/*#define HAVE_OUTFUNTYPE */
+// Define when termcap.h defines outfuntype
+//#define HAVE_OUTFUNTYPE
 
-/* Define when __DATE__ " " __TIME__ can be used */
+// Define when __DATE__ " " __TIME__ can be used
 #define HAVE_DATE_TIME
 
-/* Defined to the size of an int */
+// Defined to the size of an int
 #define VIM_SIZEOF_INT  4
 
-/* #undef USEBCOPY */
+// #undef USEBCOPY
 #define USEMEMMOVE
-/* #undef USEMEMCPY */
+// #undef USEMEMCPY
 
-/* Define when "man -s 2" is to be used */
-/* #undef USEMAN_S */
+// Define when "man -s 2" is to be used
+// #undef USEMAN_S
 
-/* Define to empty if the keyword does not work.  */
-/* #undef const */
+// Define to empty if the keyword does not work.
+// #undef const
 
-/* Define to `int' if <sys/types.h> doesn't define.  */
-/* #undef mode_t */
+// Define to `int' if <sys/types.h> doesn't define.
+// #undef mode_t
 
-/* Define to `long' if <sys/types.h> doesn't define.  */
-/* #undef off_t */
+// Define to `long' if <sys/types.h> doesn't define.
+// #undef off_t
 
-/* Define to `long' if <sys/types.h> doesn't define.  */
-/* #undef pid_t */
+// Define to `long' if <sys/types.h> doesn't define.
+// #undef pid_t
 
-/* Define to `unsigned' if <sys/types.h> doesn't define.  */
-/* #undef size_t */
+// Define to `unsigned' if <sys/types.h> doesn't define.
+// #undef size_t
 
-/* Define to `int' if <sys/types.h> doesn't define.  */
-/* #undef uid_t */
+// Define to `int' if <sys/types.h> doesn't define.
+// #undef uid_t
 
-/* Define to `unsigned int' or other type that is 32 bit.  */
+// Define to `unsigned int' or other type that is 32 bit.
 #define UINT32_T unsigned int
 
-/* Define to `int' if <sys/types.h> doesn't define.  */
-/* #undef gid_t */
+// Define to `int' if <sys/types.h> doesn't define.
+// #undef gid_t
 
-/* Define to `long' if <sys/types.h> doesn't define.  */
-/* #undef ino_t */
+// Define to `long' if <sys/types.h> doesn't define.
+// #undef ino_t
 
-/* Define if you have the nanosleep() function.  */
-/* #undef HAVE_NANOSLEEP */
+// Define if you have the nanosleep() function.
+// #undef HAVE_NANOSLEEP
 
-/* Define if you can safely include both <sys/time.h> and <time.h>.  */
+// Define if you can safely include both <sys/time.h> and <time.h>.
 #define TIME_WITH_SYS_TIME
 
-/* Define if you can safely include both <sys/time.h> and <sys/select.h>.  */
-/* #undef SYS_SELECT_WITH_SYS_TIME */
+// Define if you can safely include both <sys/time.h> and <sys/select.h>.
+// #undef SYS_SELECT_WITH_SYS_TIME
 
-/* Define as the return type of signal handlers (int or void).  */
+// Define as the return type of signal handlers (int or void).
 #define RETSIGTYPE void
 
-/* Define as the command at the end of signal handlers ("" or "return 0;").  */
+// Define as the command at the end of signal handlers ("" or "return 0;").
 #define SIGRETURN return
 
-/* Define if struct sigcontext is present */
+// Define if struct sigcontext is present
 #define HAVE_SIGCONTEXT
 
-/* Define if toupper/tolower only work on lower/uppercase characters */
-/* #define BROKEN_TOUPPER */
+// Define if toupper/tolower only work on lower/uppercase characters
+// #define BROKEN_TOUPPER
 
-/* Define if tgetstr() has a second argument that is (char *) */
-/* #undef TGETSTR_CHAR_P */
+// Define if tgetstr() has a second argument that is (char *)
+// #undef TGETSTR_CHAR_P
 
-/* Define if you have the sigset() function.  */
-/* #undef HAVE_SIGSET */
+// Define if you have the sigset() function.
+// #undef HAVE_SIGSET
 
-/* Define if you have the setpgid() function.  */
-/* #undef HAVE_SETPGID */
+// Define if you have the setpgid() function.
+// #undef HAVE_SETPGID
 
-/* Define if you have the setsid() function.  */
-/* #undef HAVE_SETSID */
+// Define if you have the setsid() function.
+// #undef HAVE_SETSID
 
-/* Define if you have the sigset() function.  */
-/* #undef HAVE_SIGSET */
+// Define if you have the sigset() function.
+// #undef HAVE_SIGSET
 
 #define TGETENT_ZERO_ERR
 #define HAVE_GETCWD
@@ -145,7 +147,7 @@
 #undef  HAVE_FCHDIR
 #undef  HAVE_LSTAT
 
-/* Hardware specific */
+// Hardware specific
 #ifdef  VAX
 #undef  HAVE_GETTIMEOFDAY
 #undef  HAVE_USLEEP
@@ -155,7 +157,7 @@
 #undef  HAVE_ISNAN
 #define HAVE_NO_LONG_LONG
 #define VIM_SIZEOF_LONG 4
-#else /* AXP and IA64 */
+#else // AXP and IA64
 #define HAVE_GETTIMEOFDAY
 #define HAVE_USLEEP
 #define HAVE_STRCASECMP
@@ -165,7 +167,7 @@
 #define VIM_SIZEOF_LONG 8
 #endif
 
-/* Compiler specific */
+// Compiler specific
 #ifdef  VAXC
 #undef  HAVE_SELECT
 #undef  HAVE_FCNTL_H
@@ -194,7 +196,7 @@
 #undef HAVE_ICONV
 #endif
 
-/* GUI support defines */
+// GUI support defines
 #if defined(FEAT_GUI_MOTIF) || defined(FEAT_GUI_GTK)
 #define HAVE_X11
 #ifdef HAVE_XPM