use _GL_ATTRIBUTE_CONST and _GL_ATTRIBUTE_PURE

[pspp] / lib / ftoastr.c

diff --git a/lib/ftoastr.c b/lib/ftoastr.c
index f74740088e971b19805c3e89a1c3d771b763b16a..ff3d87ce22d9e36e5f3048ef47ab5ca5dac64677 100644 (file)
--- a/lib/ftoastr.c
+++ b/lib/ftoastr.c
@@ -1,6 +1,6 @@
 /* floating point to accurate string
 
-   Copyright (C) 2010 Free Software Foundation, Inc.
+   Copyright (C) 2010-2011 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -17,6 +17,16 @@
 
 /* Written by Paul Eggert.  */
 
+/* This code can misbehave on some buggy or older platforms, when
+   operating on arguments on floating types other than 'double', or
+   when given unusual combinations of options.  Gnulib's
+   snprintf-posix module works around many of these problems.
+
+   This code relies on sprintf, strtod, etc. operating accurately;
+   otherwise, the resulting strings could be inaccurate or too long.  */
+
+#include <config.h>
+
 #include "ftoastr.h"
 
 #include "intprops.h"
@@ -56,6 +66,34 @@
 # define STRTOF strtod
 #endif
 
+/* On hosts where it's not known that snprintf works, use sprintf to
+   implement the subset needed here.  Typically BUFSIZE is big enough
+   and there's little or no performance hit.  */
+#if ! GNULIB_SNPRINTF
+# undef snprintf
+# define snprintf ftoastr_snprintf
+static int
+ftoastr_snprintf (char *buf, size_t bufsize, char const *format,
+                  int width, int prec, FLOAT x)
+{
+  char width_0_buffer[LENGTH == 1 ? FLT_BUFSIZE_BOUND
+                      : LENGTH == 2 ? DBL_BUFSIZE_BOUND
+                      : LDBL_BUFSIZE_BOUND];
+  int n = width;
+  if (bufsize < sizeof width_0_buffer)
+    {
+      n = sprintf (width_0_buffer, format, 0, prec, x);
+      if (n < 0)
+        return n;
+      if (n < width)
+        n = width;
+    }
+  if (n < bufsize)
+    n = sprintf (buf, format, width, prec, x);
+  return n;
+}
+#endif
+
 int
 FTOASTR (char *buf, size_t bufsize, int flags, int width, FLOAT x)
 {