[gcc r13-491] [Ada] replace call to bzero in terminals.c by call to memset

[Pierre-Marie de Rodat <pmderodat@gcc.gnu.org>]

https://gcc.gnu.org/g:dec636b831a286ab9f7773364a6f0cedf08ac9c0

commit r13-491-gdec636b831a286ab9f7773364a6f0cedf08ac9c0
Author: Joel Brobecker <brobecker@adacore.com>
Date:   Fri Mar 11 04:22:15 2022 +0000

    [Ada] replace call to bzero in terminals.c by call to memset
    
    bzero is marked as legacy in POSIX.1-2001, and using it triggers a
    deprecation warnings on some systems such as QNX. This change adjusts
    the one place where we use it in terminals.c to use memset instead.
    This, in turns, allows us to get rid of a hack for HP/UX and Solaris.
    
    gcc/ada/
    
            * terminals.c: Remove bzero #define on HP/UX or Solaris
            platforms.
            (child_setup_tty): Replace bzero call by equivalent call to
            memset.

Diff:
---
 gcc/ada/terminals.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/gcc/ada/terminals.c b/gcc/ada/terminals.c
index 32d30a49c7e..330128abf5d 100644
--- a/gcc/ada/terminals.c
+++ b/gcc/ada/terminals.c
@@ -1123,12 +1123,6 @@ __gnat_setup_winsize (void *desc ATTRIBUTE_UNUSED,
 
 #define CDISABLE _POSIX_VDISABLE
 
-/* On HP-UX and Sun system, there is a bzero function but with a different
-   signature. Use memset instead */
-#if defined (__hpux__) || defined (__sun__) || defined (_AIX)
-#   define bzero(s,n) memset (s,0,n)
-#endif
-
 /* POSIX does not specify how to open the master side of a terminal.Several
    methods are available (system specific):
       1- using a cloning device (USE_CLONE_DEVICE)
@@ -1289,8 +1283,15 @@ child_setup_tty (int fd)
   struct termios s;
   int    status;
 
-  /* ensure that s is filled with 0 */
-  bzero (&s, sizeof (s));
+  /* Ensure that s is filled with 0.
+
+     Note that we avoid using bzero for a few reasons:
+       - On HP-UX and Sun system, there is a bzero function but with
+         a different signature, thus making the use of bzero more
+	 complicated on these platforms (we used to define a bzero
+	 macro that rewrote calls to bzero into calls to memset);
+       - bzero is deprecated (marked as LEGACY in POSIX.1-2001).  */
+  memset (&s, 0, sizeof (s));
 
   /* Get the current terminal settings */
   status = tcgetattr (fd, &s);