od: fix bugs in displaying floating-point values

* NEWS: Describe patch.
* bootstrap.conf (gnulib_modules): Add ftoastr.
* src/od.c: Include ftoastr.h, not float.h.
(FLT_DIG, DBL_DIG): Remove.  No need to verify LDBL_DIG.
(FMT_BYTES_ALLOCATED): No need to worry about floating point now,
since this format is no longer used for floating point.
(PRINT_FIELDS): New macro, with most of the guts of the old PRINT_TYPE.
(PRINT_TYPE): Rewrite to use PRINT_FIELDS.
(PRINT_FLOATTYPE): New macro.  This uses the new functions from
ftoastr.
(print_float, print_double, print_long_double): Reimplement
using PRINT_FLOATTYPE.
(decode_one_format): Calculate field widths based on ftoastr-supplied
macros.
* tests/Makefile.am (TESTS): Add misc/od-float.
* tests/misc/od-float: New file.

1 files changed, 29 insertions, 34 deletions

diff --git a/src/od.c b/src/od.c
index 1d106b1b1..2f7ef000a 100644
--- a/src/od.c
+++ b/src/od.c
@@ -24,6 +24,7 @@
 #include <sys/types.h>
 #include "system.h"
 #include "error.h"
+#include "ftoastr.h"
 #include "quote.h"
 #include "xfreopen.h"
 #include "xprintf.h"
@@ -34,21 +35,9 @@
 
 #define AUTHORS proper_name ("Jim Meyering")
 
-#include <float.h>
-
 /* The default number of input bytes per output line.  */
 #define DEFAULT_BYTES_PER_BLOCK 16
 
-/* The number of decimal digits of precision in a float.  */
-#ifndef FLT_DIG
-# define FLT_DIG 7
-#endif
-
-/* The number of decimal digits of precision in a double.  */
-#ifndef DBL_DIG
-# define DBL_DIG 15
-#endif
-
 #if HAVE_UNSIGNED_LONG_LONG_INT
 typedef unsigned long long int unsigned_long_long_int;
 #else
@@ -92,17 +81,15 @@ enum output_format
 enum
   {
     FMT_BYTES_ALLOCATED =
-      MAX ((sizeof "%*.99" - 1
+           (sizeof "%*.99" - 1
             + MAX (sizeof "ld",
                    MAX (sizeof PRIdMAX,
                         MAX (sizeof PRIoMAX,
                              MAX (sizeof PRIuMAX,
-                                  sizeof PRIxMAX))))),
-           sizeof "%*.99Le")
+                                  sizeof PRIxMAX)))))
   };
 
 /* Ensure that our choice for FMT_BYTES_ALLOCATED is reasonable.  */
-verify (LDBL_DIG <= 99);
 verify (MAX_INTEGRAL_TYPE_SIZE * CHAR_BIT / 3 <= 99);
 
 /* Each output format specification (from `-t spec' or from
@@ -401,10 +388,10 @@ implies 32.  By default, od uses -A o -t oS -w16.\n\
 
 /* Define the print functions.  */
 
-#define PRINT_TYPE(N, T)                                                \
+#define PRINT_FIELDS(N, T, FMT_STRING, ACTION)                          \
 static void                                                             \
 N (size_t fields, size_t blank, void const *block,                      \
-   char const *fmt_string, int width, int pad)                          \
+   char const *FMT_STRING, int width, int pad)                          \
 {                                                                       \
   T const *p = block;                                                   \
   size_t i;                                                             \
@@ -412,11 +399,22 @@ N (size_t fields, size_t blank, void const *block,                      \
   for (i = fields; blank < i; i--)                                      \
     {                                                                   \
       int next_pad = pad * (i - 1) / fields;                            \
-      xprintf (fmt_string, pad_remaining - next_pad + width, *p++);     \
+      int adjusted_width = pad_remaining - next_pad + width;            \
+      T x = *p++;                                                       \
+      ACTION;                                                           \
       pad_remaining = next_pad;                                         \
     }                                                                   \
 }
 
+#define PRINT_TYPE(N, T)                                                \
+  PRINT_FIELDS (N, T, fmt_string, xprintf (fmt_string, adjusted_width, x))
+
+#define PRINT_FLOATTYPE(N, T, FTOASTR, BUFSIZE)                         \
+  PRINT_FIELDS (N, T, fmt_string ATTRIBUTE_UNUSED,                      \
+                char buf[BUFSIZE];                                      \
+                FTOASTR (buf, sizeof buf, 0, 0, x);                     \
+                xprintf ("%*s", adjusted_width, buf))
+
 PRINT_TYPE (print_s_char, signed char)
 PRINT_TYPE (print_char, unsigned char)
 PRINT_TYPE (print_s_short, short int)
@@ -424,11 +422,13 @@ PRINT_TYPE (print_short, unsigned short int)
 PRINT_TYPE (print_int, unsigned int)
 PRINT_TYPE (print_long, unsigned long int)
 PRINT_TYPE (print_long_long, unsigned_long_long_int)
-PRINT_TYPE (print_float, float)
-PRINT_TYPE (print_double, double)
-PRINT_TYPE (print_long_double, long double)
+
+PRINT_FLOATTYPE (print_float, float, ftoastr, FLT_BUFSIZE_BOUND)
+PRINT_FLOATTYPE (print_double, double, dtoastr, DBL_BUFSIZE_BOUND)
+PRINT_FLOATTYPE (print_long_double, long double, ldtoastr, LDBL_BUFSIZE_BOUND)
 
 #undef PRINT_TYPE
+#undef PRINT_FLOATTYPE
 
 static void
 dump_hexl_mode_trailer (size_t n_bytes, const char *block)
@@ -586,13 +586,11 @@ decode_one_format (const char *s_orig, const char *s, const char **next,
   enum size_spec size_spec;
   unsigned long int size;
   enum output_format fmt;
-  const char *pre_fmt_string;
   void (*print_function) (size_t, size_t, void const *, char const *,
                           int, int);
   const char *p;
   char c;
   int field_width;
-  int precision;
 
   assert (tspec != NULL);
 
@@ -772,34 +770,31 @@ this system doesn't provide a %lu-byte floating point type"),
         }
       size_spec = fp_type_size[size];
 
+      struct lconv const *locale = localeconv ();
+      size_t decimal_point_len =
+        (locale->decimal_point[0] ? strlen (locale->decimal_point) : 1);
+
       switch (size_spec)
         {
         case FLOAT_SINGLE:
           print_function = print_float;
-          /* FIXME - should we use %g instead of %e?  */
-          pre_fmt_string = "%%*.%de";
-          precision = FLT_DIG;
+          field_width = FLT_STRLEN_BOUND_L (decimal_point_len);
           break;
 
         case FLOAT_DOUBLE:
           print_function = print_double;
-          pre_fmt_string = "%%*.%de";
-          precision = DBL_DIG;
+          field_width = DBL_STRLEN_BOUND_L (decimal_point_len);
           break;
 
         case FLOAT_LONG_DOUBLE:
           print_function = print_long_double;
-          pre_fmt_string = "%%*.%dLe";
-          precision = LDBL_DIG;
+          field_width = LDBL_STRLEN_BOUND_L (decimal_point_len);
           break;
 
         default:
           abort ();
         }
 
-      field_width = precision + 8;
-      sprintf (tspec->fmt_string, pre_fmt_string, precision);
-      assert (strlen (tspec->fmt_string) < FMT_BYTES_ALLOCATED);
       break;
 
     case 'a':