Initial import of a C portability framework and utility functions from

remctl so that the wallet client error handling can rest on a firmer
foundation.

1 files changed, 55 insertions, 0 deletions

diff --git a/m4/snprintf.m4 b/m4/snprintf.m4
new file mode 100644
index 0000000..a09833f
--- /dev/null
+++ b/m4/snprintf.m4
@@ -0,0 +1,55 @@
+dnl snprintf.m4 -- Test for a working C99 snprintf.
+dnl $Id$
+dnl
+dnl Check for a working snprintf.  Some systems have an snprintf that doesn't
+dnl nul-terminate if the buffer isn't large enough.  Others return -1 if the
+dnl string doesn't fit into the buffer instead of returning the number of
+dnl characters that would have been formatted.  Still others don't support
+dnl NULL as the buffer argument (just to get a count of the formatted length).
+dnl
+dnl Provides RRA_FUNC_SNPRINTF, which adds snprintf.o to LIBOBJS unless a
+dnl fully working snprintf is found.
+dnl
+dnl Written by Russ Allbery <rra@stanford.edu>
+dnl Copyright 2006 Board of Trustees, Leland Stanford Jr. University
+dnl See README for licensing terms.
+
+dnl Source used by RRA_FUNC_SNPRINTF.
+define([_RRA_FUNC_SNPRINTF_SOURCE],
+[[#include <stdio.h>
+#include <stdarg.h>
+
+char buf[2];
+
+int
+test(char *format, ...)
+{
+    va_list args;
+    int count;
+
+    va_start(args, format);
+    count = vsnprintf(buf, sizeof buf, format, args);
+    va_end(args);
+    return count;
+}
+
+int
+main()
+{
+    return ((test("%s", "abcd") == 4 && buf[0] == 'a' && buf[1] == '\0'
+             && snprintf(NULL, 0, "%s", "abcd") == 4) ? 0 : 1);
+}]])
+
+dnl The user-callable test.
+AC_DEFUN([RRA_FUNC_SNPRINTF],
+[AC_CACHE_CHECK([for working snprintf], [rra_cv_func_snprintf_works],
+    [AC_TRY_RUN(_RRA_FUNC_SNPRINTF_SOURCE(),
+        [rra_cv_func_snprintf_works=yes],
+        [rra_cv_func_snprintf_works=no],
+        [rra_cv_func_snprintf_works=no])])
+if test "$rra_cv_func_snprintf_works" = yes ; then
+    AC_DEFINE([HAVE_SNPRINTF], 1,
+        [Define if your system has a working snprintf function.])
+else
+    AC_LIBOBJ([snprintf])
+fi])