[PATCH:xmodmap 3/3] Replace chk_malloc + sprintf with asprintf

[Alan Coopersmith]

Includes local private copy of asprintf for OS'es without it in libc.
Removes chk_malloc as no callers remain anymore.

Signed-off-by: Alan Coopersmith <alan.coopersmith at oracle.com>
---
 configure.ac |    2 +-
 xmodmap.c    |   69 +++++++++++++++++++++++++++++++++++++++++++++------------
 xmodmap.h    |    5 +++-
 3 files changed, 59 insertions(+), 17 deletions(-)

diff --git a/configure.ac b/configure.ac
index de88e4c..f9ebca3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -37,7 +37,7 @@ XORG_DEFAULT_OPTIONS
 
 AC_CONFIG_HEADERS([config.h])
 
-AC_CHECK_FUNCS([strncasecmp])
+AC_CHECK_FUNCS([strncasecmp asprintf])
 
 # Checks for pkg-config packages
 PKG_CHECK_MODULES(XMODMAP, x11 xproto >= 7.0.17)
diff --git a/xmodmap.c b/xmodmap.c
index f49bc33..58a8e70 100644
--- a/xmodmap.c
+++ b/xmodmap.c
@@ -31,6 +31,7 @@ from The Open Group.
 #include <stdio.h>
 #include <stdlib.h>
 #include <ctype.h>
+#include <stdarg.h>
 #include "xmodmap.h"
 
 const char *ProgramName;
@@ -50,16 +51,54 @@ Exit(int status)
     exit (status);
 }
 
-void *
-chk_malloc(size_t n_bytes)
+static void _X_NORETURN
+FatalError(const char *message)
 {
-    void *buf = malloc(n_bytes);
-    if (!buf) {
-	fprintf(stderr, "%s: Could not allocate %d bytes\n", ProgramName, (int)n_bytes);
-	Exit(-1);
+    fprintf(stderr, "%s: %s\n", ProgramName, message);
+    Exit(-1);
+}
+
+#ifndef HAVE_ASPRINTF
+/* sprintf variant found in newer libc's which allocates string to print to */
+static int _X_ATTRIBUTE_PRINTF(2,3)
+asprintf(char ** ret, const char *format, ...)
+{
+    char buf[256];
+    int len;
+    va_list ap;
+
+    va_start(ap, format);
+    len = vsnprintf(buf, sizeof(buf), format, ap);
+    va_end(ap);
+
+    if (len < 0)
+	return -1;
+
+    if (len < sizeof(buf))
+    {
+	*ret = strdup(buf);
     }
-    return buf;
+    else
+    {
+	*ret = malloc(len + 1); /* snprintf doesn't count trailing '\0' */
+	if (*ret != NULL)
+	{
+	    va_start(ap, format);
+	    len = vsnprintf(*ret, len + 1, format, ap);
+	    va_end(ap);
+	    if (len < 0) {
+		free(*ret);
+		*ret = NULL;
+	    }
+	}
+    }
+
+    if (*ret == NULL)
+	return -1;
+
+    return len;
 }
+#endif /* HAVE_ASPRINTF */
 
 static const char help_message[] = 
 "\nwhere options include:\n"
@@ -247,11 +286,11 @@ main(int argc, char *argv[])
 		  char *cmd;
 		  didAnything = True;
 		  if (++i >= argc) usage ();
-		  cmd = chk_malloc (strlen ("remove control = ") + strlen (argv[i]) + 1);
-		  (void) sprintf (cmd, "remove %s = %s",
+		  if (asprintf (&cmd, "remove %s = %s",
 				  ((arg[1] == 's') ? "shift" :
 				   ((arg[1] == 'l') ? "lock" :
-				    "control")), argv[i]);
+				    "control")), argv[i]) == -1)
+		      FatalError("Could not allocate memory for remove cmd");
 		  process_line (cmd);
 		  continue;
 	      }
@@ -269,8 +308,8 @@ main(int argc, char *argv[])
 		  char *cmd;
 		  didAnything = True;
 		  if (++i >= argc) usage ();
-		  cmd = chk_malloc (strlen ("add modX = ") + strlen (argv[i]) + 1);
-		  (void) sprintf (cmd, "add mod%c = %s", arg[1], argv[i]);
+		  if (asprintf (&cmd, "add mod%c = %s", arg[1], argv[i]) == -1)
+		      FatalError("Could not allocate memory for add cmd");
 		  process_line (cmd);
 		  continue;
 	      }
@@ -285,11 +324,11 @@ main(int argc, char *argv[])
 		  char *cmd;
 		  didAnything = True;
 		  if (++i >= argc) usage ();
-		  cmd = chk_malloc (strlen ("add control = ") + strlen (argv[i]) + 1);
-		  (void) sprintf (cmd, "add %s = %s",
+		  if (asprintf (&cmd, "add %s = %s",
 				  ((arg[1] == 's') ? "shift" :
 				   ((arg[1] == 'l') ? "lock" :
-				    "control")), argv[i]);
+				    "control")), argv[i]) == -1)
+		      FatalError("Could not allocate memory for remove cmd");
 		  process_line (cmd);
 		  continue;
 	      }
diff --git a/xmodmap.h b/xmodmap.h
index 1540b2a..686ee1b 100644
--- a/xmodmap.h
+++ b/xmodmap.h
@@ -26,6 +26,10 @@ from The Open Group.
 
 */
 
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
 extern const char *ProgramName;
 extern Display *dpy;
 extern int min_keycode, max_keycode;
@@ -56,4 +60,3 @@ extern void PrintPointerMap(FILE *fp);
 extern int SetPointerMap(unsigned char *map, int n);
 
 extern void _X_NORETURN Exit(int status);
-extern void *chk_malloc(size_t n_bytes);
-- 
1.7.3.2