From 35ef9d158396dbf013a862dd8f830db64909826b Mon Sep 17 00:00:00 2001
From: Ralph Corderoy <ralph@inputplus.co.uk>
Date: Mon, 21 Aug 2017 11:09:02 +0100
Subject: [PATCH] Add ZERO(p) for the typical memset(p, 0, sizeof *p) dance.

Also seen as memset(&foo->bar_xyzzy, 0, sizeof foo->bar_xyzzy).  I find
it tedious to keep checking the parameters are in agreement when reading
the code.
---
 h/utils.h         | 3 +++
 sbr/client.c      | 2 +-
 sbr/datetime.c    | 2 +-
 sbr/dtimep.l      | 3 ++-
 sbr/fmt_compile.c | 2 +-
 sbr/fmt_scan.c    | 2 +-
 sbr/mts.c         | 2 +-
 sbr/netsec.c      | 2 +-
 uip/fmttest.c     | 2 +-
 uip/replsbr.c     | 2 +-
 10 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/h/utils.h b/h/utils.h
index 19fbdcc6..dd3fb431 100644
--- a/h/utils.h
+++ b/h/utils.h
@@ -31,6 +31,9 @@ void mh_xfree(void *ptr);
 /* Set p to point to newly allocated, zeroed, memory. */
 #define NEW0(p) ((p) = mh_xcalloc(1, sizeof *(p)))
 
+/* Zero the bytes to which p points. */
+#define ZERO(p) memset((p), 0, sizeof *(p))
+
 char *pwd(void);
 char *add(const char *, char *);
 char *addlist(char *, const char *);
diff --git a/sbr/client.c b/sbr/client.c
index 1a7cb7fd..a64461bc 100644
--- a/sbr/client.c
+++ b/sbr/client.c
@@ -28,7 +28,7 @@ client (char *server, char *service, char *response, int len_response,
 	return NOTOK;
     }
 
-    memset(&hints, 0, sizeof(hints));
+    ZERO(&hints);
 #ifdef AI_ADDRCONFIG
     hints.ai_flags = AI_ADDRCONFIG;
 #endif
diff --git a/sbr/datetime.c b/sbr/datetime.c
index a5f6c77b..9ecff53c 100644
--- a/sbr/datetime.c
+++ b/sbr/datetime.c
@@ -64,7 +64,7 @@ parse_datetime (const char *datetime, const char *zone, int dst,
     int form_1 = 0;
     int items_matched;
 
-    memset(tws, 0, sizeof *tws);
+    ZERO(tws);
     items_matched =
         sscanf (datetime, "%4d%2d%2dT%2d%2d%2d%c",
                 &tws->tw_year, &tws->tw_mon, &tws->tw_mday,
diff --git a/sbr/dtimep.l b/sbr/dtimep.l
index e9dd8153..238af863 100644
--- a/sbr/dtimep.l
+++ b/sbr/dtimep.l
@@ -11,6 +11,7 @@
 %a5000
 %{
 #include <h/nmh.h>
+#include <h/utils.h>
 #include <h/tws.h>
 
   /* Since we're looking at a string at a time, don't worry about
@@ -231,7 +232,7 @@ nl      [ \t\n()]
   char *cp;
   static struct tws tw; 
 
-  memset(&tw,0,sizeof(struct tws));
+  ZERO(&tw);
 
   lexhandle = yy_scan_string(lexstr);
 %}
diff --git a/sbr/fmt_compile.c b/sbr/fmt_compile.c
index 5a4e4b8b..389e16c4 100644
--- a/sbr/fmt_compile.c
+++ b/sbr/fmt_compile.c
@@ -559,7 +559,7 @@ do_name(char *sp, int preprocess)
 	    CERROR("component used as both date and address");
 	}
 	if (cm->c_tws) {
-	    memset (cm->c_tws, 0, sizeof *cm->c_tws);
+	    ZERO(cm->c_tws);
 	} else {
 	    NEW0(cm->c_tws);
 	}
diff --git a/sbr/fmt_scan.c b/sbr/fmt_scan.c
index 075b7dd6..49fc717f 100644
--- a/sbr/fmt_scan.c
+++ b/sbr/fmt_scan.c
@@ -989,7 +989,7 @@ fmt_scan (struct format *format, charstring_t scanlp, int width, int *dat,
 		*comp->c_tws = *tws;
 		comp->c_flags &= ~CF_TRUE;
 	    } else if ((comp->c_flags & CF_DATEFAB) == 0) {
-		memset (comp->c_tws, 0, sizeof *comp->c_tws);
+		ZERO(comp->c_tws);
 		comp->c_flags = CF_TRUE;
 	    }
 	    comp->c_flags |= CF_PARSED;
diff --git a/sbr/mts.c b/sbr/mts.c
index ae617cec..f6180b03 100644
--- a/sbr/mts.c
+++ b/sbr/mts.c
@@ -235,7 +235,7 @@ LocalName (int flag)
 	gethostname (buf, sizeof(buffer0) - 1);
 	/* now fully qualify our name */
 
-	memset(&hints, 0, sizeof(hints));
+        ZERO(&hints);
 	hints.ai_flags = AI_CANONNAME;
 	hints.ai_family = PF_UNSPEC;
 	if (getaddrinfo(buf, NULL, &hints, &res) == 0) {
diff --git a/sbr/netsec.c b/sbr/netsec.c
index 3fcb2cf5..58cab1bb 100644
--- a/sbr/netsec.c
+++ b/sbr/netsec.c
@@ -1217,7 +1217,7 @@ netsec_negotiate_sasl(netsec_context *nsc, const char *mechlist, char **errstr)
      * messages.
      */
 
-    memset(&secprops, 0, sizeof(secprops));
+    ZERO(&secprops);
     secprops.maxbufsize = SASL_MAXRECVBUF;
 
     /*
diff --git a/uip/fmttest.c b/uip/fmttest.c
index 83e5c26d..e5323e64 100644
--- a/uip/fmttest.c
+++ b/uip/fmttest.c
@@ -336,7 +336,7 @@ main (int argc, char **argv)
      */
 
     if (dupaddrs == 0 || trace) {
-    	memset(&cb, 0, sizeof(cb));
+    	ZERO(&cb);
 	cbp = &cb;
 
 	if (dupaddrs == 0) {
diff --git a/uip/replsbr.c b/uip/replsbr.c
index d3ba2709..2444aa3c 100644
--- a/uip/replsbr.c
+++ b/uip/replsbr.c
@@ -205,7 +205,7 @@ finished:
     dat[2] = 0;
     dat[3] = outputlinelen;
     dat[4] = 0;
-    memset(&cb, 0, sizeof(cb));
+    ZERO(&cb);
     cb.formataddr = replformataddr;
     cb.concataddr = replconcataddr;
     fmt_scan (fmt, scanl, i, dat, &cb);
-- 
2.56.0