From b18912cda823452bc139fe1cb524a08fc12df1f1 Mon Sep 17 00:00:00 2001
From: Mark Pizzolato <mark@infocomm.com>
Date: Mon, 30 Dec 2019 15:33:51 -0800
Subject: [PATCH] SCP: Silence GCC optimizer warnings about unused function
 results

---
 scp.c            |  2 +-
 sim_console.c    |  2 +-
 sim_ether.c      | 14 +++++++-------
 sim_frontpanel.c |  2 +-
 4 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/scp.c b/scp.c
index 3cc41f41..77e03a32 100644
--- a/scp.c
+++ b/scp.c
@@ -13618,7 +13618,7 @@ rewind (tmp);
 /* Discard leading blank lines/redundant titles */
 
 for (i =0; i < skiplines; i++)
-    fgets (tbuf, sizeof (tbuf), tmp);
+    if (fgets (tbuf, sizeof (tbuf), tmp)) {};
 
 while (fgets (tbuf, sizeof (tbuf), tmp)) {
     if (tbuf[0] != '\n')
diff --git a/sim_console.c b/sim_console.c
index 2eb20859..b084e6c2 100644
--- a/sim_console.c
+++ b/sim_console.c
@@ -4219,7 +4219,7 @@ static t_stat sim_os_putchar (int32 out)
 char c;
 
 c = out;
-(void)write (1, &c, 1);
+if (write (1, &c, 1)) {};
 return SCPE_OK;
 }
 
diff --git a/sim_ether.c b/sim_ether.c
index f242e909..fd02d25d 100644
--- a/sim_ether.c
+++ b/sim_ether.c
@@ -417,7 +417,7 @@ t_stat eth_mac_scan_ex (ETH_MAC* mac, const char* strmac, UNIT *uptr)
   memset (&state, 0, sizeof(state));
   _eth_get_system_id (state.system_id, sizeof(state.system_id));
   strlcpy (state.sim, sim_name, sizeof(state.sim));
-  getcwd (state.cwd, sizeof(state.cwd));
+  if (getcwd (state.cwd, sizeof(state.cwd))) {};
   if (uptr)
     strlcpy (state.uname, sim_uname (uptr), sizeof(state.uname));
   cptr = strchr (strmac, '>');
@@ -426,7 +426,7 @@ t_stat eth_mac_scan_ex (ETH_MAC* mac, const char* strmac, UNIT *uptr)
     strlcpy (state.file, cptr + 1, sizeof(state.file));
     if ((f = fopen (state.file, "r"))) {
       filebuf[sizeof(filebuf)-1] = '\0';
-      fgets (filebuf, sizeof(filebuf)-1, f);
+      if (fgets (filebuf, sizeof(filebuf)-1, f)) {};
       strmac = filebuf;
       fclose (f);
       strcpy (state.file, "");  /* avoid saving */
@@ -1573,10 +1573,10 @@ static void eth_get_nic_hw_addr(ETH_DEV* dev, const char *devname)
     memset(command, 0, sizeof(command));
     /* try to force an otherwise unused interface to be turned on */
     snprintf(command, sizeof(command)-1, "ifconfig %.*s up", (int)(sizeof(command) - 14), devname);
-    (void)system(command);
+    if (system(command)) {};
     for (i=0; patterns[i] && (0 == dev->have_host_nic_phy_addr); ++i) {
       snprintf(command, sizeof(command)-1, "ifconfig %.*s | %s  >NIC.hwaddr", (int)(sizeof(command) - (26 + strlen(patterns[i]))), devname, patterns[i]);
-      (void)system(command);
+      if (system(command)) {};
       if (NULL != (f = fopen("NIC.hwaddr", "r"))) {
         while (0 == dev->have_host_nic_phy_addr) {
           if (fgets(command, sizeof(command)-1, f)) {
@@ -1662,12 +1662,12 @@ FILE *f;
 
 memset (buf, 0, buf_size);
 if ((f = fopen ("/etc/machine-id", "r"))) {
-  fread (buf, 1, buf_size, f);
+  if (fread (buf, 1, buf_size - 1, f)) {};
   fclose (f);
   }
 else {
   if ((f = popen ("hostname", "r"))) {
-    fread (buf, 1, buf_size, f);
+    if (fread (buf, 1, buf_size - 1, f)) {};
     pclose (f);
     }
   }
@@ -2165,7 +2165,7 @@ else { /* !tap: */
             /* try to force an otherwise unused interface to be turned on */
             memset(command, 0, sizeof(command));
             snprintf(command, sizeof(command)-1, "ifconfig %s up", savname);
-            (void)system(command);
+            if (system(command)) {};
             errbuf[0] = '\0';
             *handle = (void*) pcap_open_live(savname, bufsz, ETH_PROMISC, PCAP_READ_TIMEOUT, errbuf);
             }
diff --git a/sim_frontpanel.c b/sim_frontpanel.c
index 2ad2a2c4..32b2b0fd 100644
--- a/sim_frontpanel.c
+++ b/sim_frontpanel.c
@@ -867,7 +867,7 @@ if (!simulator_panel) {
     p->pidProcess = fork();
     if (p->pidProcess == 0) {
         close (0); close (1); close (2);        /* make sure not to pass the open standard handles */
-        dup (dup (open ("/dev/null", O_RDWR))); /* open standard handles to /dev/null */
+        if (dup (dup (open ("/dev/null", O_RDWR)))) {}; /* open standard handles to /dev/null */
         if (execlp (sim_path, sim_path, p->temp_config, NULL, NULL)) {
             perror ("execl");
             exit(errno);