Imported gcc-4.4.3

[msp430-gcc.git] / gmp / printf / vasprintf.c

diff --git a/gmp/printf/vasprintf.c b/gmp/printf/vasprintf.c
new file mode 100644 (file)
index 0000000..4ed4c5d
--- /dev/null
+++ b/gmp/printf/vasprintf.c
@@ -0,0 +1,113 @@
+/* gmp_vasprintf -- formatted output to an allocated space.
+
+Copyright 2001 Free Software Foundation, Inc.
+
+This file is part of the GNU MP Library.
+
+The GNU MP Library is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 3 of the License, or (at your
+option) any later version.
+
+The GNU MP Library is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */
+
+#include "config.h"
+
+#if HAVE_STDARG
+#include <stdarg.h>
+#else
+#include <varargs.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "gmp.h"
+#include "gmp-impl.h"
+
+#if ! HAVE_VSNPRINTF
+#define vsnprintf  __gmp_replacement_vsnprintf
+#endif
+
+
+/* vasprintf isn't used since we prefer all GMP allocs to go through
+   __gmp_allocate_func, and in particular we don't want the -1 return from
+   vasprintf for out-of-memory, instead __gmp_allocate_func should handle
+   that.  Using vsnprintf unfortunately means we might have to re-run it if
+   our current space is insufficient.
+
+   The initial guess for the needed space is an arbitrary 256 bytes.  If
+   that (and any extra GMP_ASPRINTF_T_NEED might give) isn't enough then an
+   ISO C99 standard vsnprintf will tell us what we really need.
+
+   GLIBC 2.0.x vsnprintf returns either -1 or space-1 to indicate overflow,
+   without giving any indication how much is really needed.  In this case
+   keep trying with double the space each time.
+
+   A return of space-1 is success on a C99 vsnprintf, but we're not
+   bothering to identify which style vsnprintf we've got, so just take the
+   pessimistic option and assume it's glibc 2.0.x.
+
+   Notice the use of ret+2 for the new space in the C99 case.  This ensures
+   the next vsnprintf return value will be space-2, which is unambiguously
+   successful.  But actually GMP_ASPRINTF_T_NEED() will realloc to even
+   bigger than that ret+2.
+
+   vsnprintf might trash it's given ap, so copy it in case we need to use it
+   more than once.  See comments with gmp_snprintf_format.  */
+
+static int
+gmp_asprintf_format (struct gmp_asprintf_t *d, const char *fmt,
+                     va_list orig_ap)
+{
+  int      ret;
+  va_list  ap;
+  size_t   space = 256;
+
+  for (;;)
+    {
+      GMP_ASPRINTF_T_NEED (d, space);
+      space = d->alloc - d->size;
+      va_copy (ap, orig_ap);
+      ret = vsnprintf (d->buf + d->size, space, fmt, ap);
+      if (ret == -1)
+        {
+          ASSERT (strlen (d->buf + d->size) == space-1);
+          ret = space-1;
+        }
+
+      /* done if output fits in our space */
+      if (ret < space-1)
+        break;
+
+      if (ret == space-1)
+        space *= 2;     /* possible glibc 2.0.x, so double */
+      else
+        space = ret+2;  /* C99, so now know space required */
+    }
+
+  d->size += ret;
+  return ret;
+}
+
+const struct doprnt_funs_t  __gmp_asprintf_funs = {
+  (doprnt_format_t) gmp_asprintf_format,
+  (doprnt_memory_t) __gmp_asprintf_memory,
+  (doprnt_reps_t)   __gmp_asprintf_reps,
+  (doprnt_final_t)  __gmp_asprintf_final
+};
+
+int
+gmp_vasprintf (char **result, const char *fmt, va_list ap)
+{
+  struct gmp_asprintf_t  d;
+  GMP_ASPRINTF_T_INIT (d, result);
+  return __gmp_doprnt (&__gmp_asprintf_funs, &d, fmt, ap);
+}