I had thought that the result of sprintf(..., "%015.10x", ...)
was unspecified by POSIX and ISO C. But in fact
ISO C 99 § 7.19.6.1.(6)
ISO C 11 § 7.21.6.1.(6)
ISO C 23 § 7.23.6.1.(6)
all say: "For d, i, o, u, x, and X conversions, if a precision is specified,
the 0 flag is ignored." And likewise for swprintf.
Our vasnprintf does not implement it like this so far, as evidenced by building
a testdir of module 'vasnwprintf-posix' on mingw 5, without
__USE_MINGW_ANSI_STDIO: With NEED_PRINTF_UNBOUNDED_PRECISION the unit test
succeeds, without NEED_PRINTF_UNBOUNDED_PRECISION it fails. This is an
unintended effect of NEED_PRINTF_UNBOUNDED_PRECISION.
This patch fixes our vasnprintf implementation. As a consequence, some
previous special cases in the unit tests no longer occur.
2023-05-03 Bruno Haible <br...@clisp.org>
vasnprintf, vasnwprintf: Make '0' flag handling more ISO C compliant.
* lib/vasnprintf.c (VASNPRINTF): When doing the padding ourselves,
ignore the '0' flag if a precision is specified and the conversion is
one of d, i, o, u, x, X, b, B.
* tests/test-vasnprintf-posix.c (test_function): Update expected results
accordingly.
* tests/test-vasprintf-posix.c (test_function): Likewise.
* tests/test-snprintf-posix.h (test_function): Likewise.
* tests/test-sprintf-posix.h (test_function): Likewise.
* tests/test-vasnwprintf-posix.c (test_function): Likewise.
diff --git a/lib/vasnprintf.c b/lib/vasnprintf.c
index efd610ebe4..802790e14e 100644
--- a/lib/vasnprintf.c
+++ b/lib/vasnprintf.c
@@ -5612,7 +5612,7 @@ VASNPRINTF (DCHAR_T *resultbuf, size_t *lengthp,
#if !USE_SNPRINTF || WIDE_CHAR_VERSION || !HAVE_SNPRINTF_RETVAL_C99 ||
USE_MSVC__SNPRINTF || !DCHAR_IS_TCHAR || ENABLE_UNISTDIO ||
NEED_PRINTF_FLAG_LEFTADJUST || NEED_PRINTF_FLAG_ZERO ||
NEED_PRINTF_UNBOUNDED_PRECISION
size_t width;
#endif
-#if !USE_SNPRINTF || (WIDE_CHAR_VERSION && DCHAR_IS_TCHAR) ||
!HAVE_SNPRINTF_RETVAL_C99 || USE_MSVC__SNPRINTF ||
NEED_PRINTF_UNBOUNDED_PRECISION
+#if !USE_SNPRINTF || (WIDE_CHAR_VERSION && DCHAR_IS_TCHAR) ||
!HAVE_SNPRINTF_RETVAL_C99 || USE_MSVC__SNPRINTF || (WIDE_CHAR_VERSION &&
MUSL_LIBC) || !DCHAR_IS_TCHAR || ENABLE_UNISTDIO || NEED_PRINTF_FLAG_LEFTADJUST
|| NEED_PRINTF_FLAG_ZERO || NEED_PRINTF_UNBOUNDED_PRECISION
int has_precision;
size_t precision;
#endif
@@ -5669,13 +5669,13 @@ VASNPRINTF (DCHAR_T *resultbuf, size_t *lengthp,
width = xsum (xtimes (width, 10), *digitp++ - '0');
while (digitp != dp->width_end);
}
-#if (WIDE_CHAR_VERSION && MUSL_LIBC) || !DCHAR_IS_TCHAR || ENABLE_UNISTDIO ||
NEED_PRINTF_FLAG_LEFTADJUST || NEED_PRINTF_FLAG_ZERO ||
NEED_PRINTF_UNBOUNDED_PRECISION
+# if (WIDE_CHAR_VERSION && MUSL_LIBC) || !DCHAR_IS_TCHAR || ENABLE_UNISTDIO ||
NEED_PRINTF_FLAG_LEFTADJUST || NEED_PRINTF_FLAG_ZERO ||
NEED_PRINTF_UNBOUNDED_PRECISION
has_width = 1;
-#endif
+# endif
}
#endif
-#if !USE_SNPRINTF || (WIDE_CHAR_VERSION && DCHAR_IS_TCHAR) ||
!HAVE_SNPRINTF_RETVAL_C99 || USE_MSVC__SNPRINTF ||
NEED_PRINTF_UNBOUNDED_PRECISION
+#if !USE_SNPRINTF || (WIDE_CHAR_VERSION && DCHAR_IS_TCHAR) ||
!HAVE_SNPRINTF_RETVAL_C99 || USE_MSVC__SNPRINTF || (WIDE_CHAR_VERSION &&
MUSL_LIBC) || !DCHAR_IS_TCHAR || ENABLE_UNISTDIO || NEED_PRINTF_FLAG_LEFTADJUST
|| NEED_PRINTF_FLAG_ZERO || NEED_PRINTF_UNBOUNDED_PRECISION
has_precision = 0;
precision = 6;
if (dp->precision_start != dp->precision_end)
@@ -6794,7 +6794,22 @@ VASNPRINTF (DCHAR_T *resultbuf, size_t *lengthp,
for (; pad > 0; pad--)
*p++ = ' ';
}
- else if ((flags & FLAG_ZERO) && pad_ptr != NULL)
+ else if ((flags & FLAG_ZERO) && pad_ptr != NULL
+ /* ISO C says: "For d, i, o, u, x, and X
+ conversions, if a precision is
+ specified, the 0 flag is ignored. */
+ && !(has_precision
+ && (dp->conversion == 'd'
+ || dp->conversion == 'i'
+ || dp->conversion == 'o'
+ || dp->conversion == 'u'
+ || dp->conversion == 'x'
+ || dp->conversion == 'X'
+ /* Although ISO C does not
+ require it, treat 'b' and
'B'
+ like 'x' and 'X'. */
+ || dp->conversion == 'b'
+ || dp->conversion == 'B')))
{
/* Pad with zeroes. */
DCHAR_T *q = end;
diff --git a/tests/test-snprintf-posix.h b/tests/test-snprintf-posix.h
index 5b81910ec3..482335a3ef 100644
--- a/tests/test-snprintf-posix.h
+++ b/tests/test-snprintf-posix.h
@@ -3187,14 +3187,9 @@ test_function (int (*my_snprintf) (char *, size_t, const
char *, ...))
{ /* Padding and precision. */
int retval =
my_snprintf (result, sizeof (result), "%015.10x %d", 12348, 33, 44, 55);
- /* Neither ISO C nor POSIX specify that the '0' flag is ignored when a
width
- and a precision are both present. But most implementations do so. */
- #ifdef __MINGW32__
- ASSERT (strcmp (result, "00000000000303c 33") == 0 /* mingw 5 */
- || strcmp (result, " 000000303c 33") == 0 /* mingw 10 */);
- #else
+ /* ISO C 99 § 7.19.6.1.(6) says: "For d, i, o, u, x, and X conversions, if
a
+ precision is specified, the 0 flag is ignored." */
ASSERT (strcmp (result, " 000000303c 33") == 0);
- #endif
ASSERT (retval == strlen (result));
}
@@ -3250,14 +3245,9 @@ test_function (int (*my_snprintf) (char *, size_t, const
char *, ...))
{ /* FLAG_ALT with a positive number and padding and precision. */
int retval =
my_snprintf (result, sizeof (result), "%0#15.10x %d", 12348, 33, 44, 55);
- /* Neither ISO C nor POSIX specify that the '0' flag is ignored when a
width
- and a precision are both present. But most implementations do so. */
- #ifdef __MINGW32__
- ASSERT (strcmp (result, "0x000000000303c 33") == 0 /* mingw 5 */
- || strcmp (result, " 0x000000303c 33") == 0 /* mingw 10 */);
- #else
+ /* ISO C 99 § 7.19.6.1.(6) says: "For d, i, o, u, x, and X conversions, if
a
+ precision is specified, the 0 flag is ignored." */
ASSERT (strcmp (result, " 0x000000303c 33") == 0);
- #endif
ASSERT (retval == strlen (result));
}
diff --git a/tests/test-sprintf-posix.h b/tests/test-sprintf-posix.h
index a0b5eb3391..c0957a6967 100644
--- a/tests/test-sprintf-posix.h
+++ b/tests/test-sprintf-posix.h
@@ -3163,14 +3163,9 @@ test_function (int (*my_sprintf) (char *, const char *,
...))
{ /* Padding and precision. */
int retval =
my_sprintf (result, "%015.10x %d", 12348, 33, 44, 55);
- /* Neither ISO C nor POSIX specify that the '0' flag is ignored when a
width
- and a precision are both present. But most implementations do so. */
- #ifdef __MINGW32__
- ASSERT (strcmp (result, "00000000000303c 33") == 0 /* mingw 5 */
- || strcmp (result, " 000000303c 33") == 0 /* mingw 10 */);
- #else
+ /* ISO C 99 § 7.19.6.1.(6) says: "For d, i, o, u, x, and X conversions, if
a
+ precision is specified, the 0 flag is ignored." */
ASSERT (strcmp (result, " 000000303c 33") == 0);
- #endif
ASSERT (retval == strlen (result));
}
@@ -3226,14 +3221,9 @@ test_function (int (*my_sprintf) (char *, const char *,
...))
{ /* FLAG_ALT with a positive number and padding and precision. */
int retval =
my_sprintf (result, "%0#15.10x %d", 12348, 33, 44, 55);
- /* Neither ISO C nor POSIX specify that the '0' flag is ignored when a
width
- and a precision are both present. But most implementations do so. */
- #ifdef __MINGW32__
- ASSERT (strcmp (result, "0x000000000303c 33") == 0 /* mingw 5 */
- || strcmp (result, " 0x000000303c 33") == 0 /* mingw 10 */);
- #else
+ /* ISO C 99 § 7.19.6.1.(6) says: "For d, i, o, u, x, and X conversions, if
a
+ precision is specified, the 0 flag is ignored." */
ASSERT (strcmp (result, " 0x000000303c 33") == 0);
- #endif
ASSERT (retval == strlen (result));
}
diff --git a/tests/test-vasnprintf-posix.c b/tests/test-vasnprintf-posix.c
index 51b1d26a33..33387c32e7 100644
--- a/tests/test-vasnprintf-posix.c
+++ b/tests/test-vasnprintf-posix.c
@@ -4145,14 +4145,9 @@ test_function (char * (*my_asnprintf) (char *, size_t *,
const char *, ...))
char *result =
my_asnprintf (NULL, &length, "%015.10x %d", 12348, 33, 44, 55);
ASSERT (result != NULL);
- /* Neither ISO C nor POSIX specify that the '0' flag is ignored when a
width
- and a precision are both present. But most implementations do so. */
- #ifdef __MINGW32__
- ASSERT (strcmp (result, "00000000000303c 33") == 0 /* mingw 5 */
- || strcmp (result, " 000000303c 33") == 0 /* mingw 10 */);
- #else
+ /* ISO C 99 § 7.19.6.1.(6) says: "For d, i, o, u, x, and X conversions, if
a
+ precision is specified, the 0 flag is ignored." */
ASSERT (strcmp (result, " 000000303c 33") == 0);
- #endif
ASSERT (length == strlen (result));
free (result);
}
@@ -4232,14 +4227,9 @@ test_function (char * (*my_asnprintf) (char *, size_t *,
const char *, ...))
char *result =
my_asnprintf (NULL, &length, "%0#15.10x %d", 12348, 33, 44, 55);
ASSERT (result != NULL);
- /* Neither ISO C nor POSIX specify that the '0' flag is ignored when a
width
- and a precision are both present. But most implementations do so. */
- #ifdef __MINGW32__
- ASSERT (strcmp (result, "0x000000000303c 33") == 0 /* mingw 5 */
- || strcmp (result, " 0x000000303c 33") == 0 /* mingw 10 */);
- #else
+ /* ISO C 99 § 7.19.6.1.(6) says: "For d, i, o, u, x, and X conversions, if
a
+ precision is specified, the 0 flag is ignored." */
ASSERT (strcmp (result, " 0x000000303c 33") == 0);
- #endif
ASSERT (length == strlen (result));
free (result);
}
diff --git a/tests/test-vasnwprintf-posix.c b/tests/test-vasnwprintf-posix.c
index 67e6654e5c..351fc8b8c2 100644
--- a/tests/test-vasnwprintf-posix.c
+++ b/tests/test-vasnwprintf-posix.c
@@ -4203,13 +4203,9 @@ test_function (wchar_t * (*my_asnwprintf) (wchar_t *,
size_t *, const wchar_t *,
wchar_t *result =
my_asnwprintf (NULL, &length, L"%015.10x %d", 12348, 33, 44, 55);
ASSERT (result != NULL);
- /* Neither ISO C nor POSIX specify that the '0' flag is ignored when a
width
- and a precision are both present. But most implementations do so. */
- #if MUSL_LIBC
- ASSERT (wcscmp (result, L"00000000000303c 33") == 0);
- #else
+ /* ISO C 99 § 7.24.2.1.(6) says: "For d, i, o, u, x, and X conversions, if
a
+ precision is specified, the 0 flag is ignored." */
ASSERT (wcscmp (result, L" 000000303c 33") == 0);
- #endif
ASSERT (length == wcslen (result));
free (result);
}
@@ -4289,13 +4285,9 @@ test_function (wchar_t * (*my_asnwprintf) (wchar_t *,
size_t *, const wchar_t *,
wchar_t *result =
my_asnwprintf (NULL, &length, L"%0#15.10x %d", 12348, 33, 44, 55);
ASSERT (result != NULL);
- /* Neither ISO C nor POSIX specify that the '0' flag is ignored when a
width
- and a precision are both present. But most implementations do so. */
- #if MUSL_LIBC
- ASSERT (wcscmp (result, L"0x000000000303c 33") == 0);
- #else
+ /* ISO C 99 § 7.24.2.1.(6) says: "For d, i, o, u, x, and X conversions, if
a
+ precision is specified, the 0 flag is ignored." */
ASSERT (wcscmp (result, L" 0x000000303c 33") == 0);
- #endif
ASSERT (length == wcslen (result));
free (result);
}
diff --git a/tests/test-vasprintf-posix.c b/tests/test-vasprintf-posix.c
index 858a477a43..897109537f 100644
--- a/tests/test-vasprintf-posix.c
+++ b/tests/test-vasprintf-posix.c
@@ -4086,14 +4086,9 @@ test_function (int (*my_asprintf) (char **, const char
*, ...))
int retval =
my_asprintf (&result, "%015.10x %d", 12348, 33, 44, 55);
ASSERT (result != NULL);
- /* Neither ISO C nor POSIX specify that the '0' flag is ignored when a
width
- and a precision are both present. But most implementations do so. */
- #ifdef __MINGW32__
- ASSERT (strcmp (result, "00000000000303c 33") == 0 /* mingw 5 */
- || strcmp (result, " 000000303c 33") == 0 /* mingw 10 */);
- #else
+ /* ISO C 99 § 7.19.6.1.(6) says: "For d, i, o, u, x, and X conversions, if
a
+ precision is specified, the 0 flag is ignored." */
ASSERT (strcmp (result, " 000000303c 33") == 0);
- #endif
ASSERT (retval == strlen (result));
free (result);
}
@@ -4173,14 +4168,9 @@ test_function (int (*my_asprintf) (char **, const char
*, ...))
int retval =
my_asprintf (&result, "%0#15.10x %d", 12348, 33, 44, 55);
ASSERT (result != NULL);
- /* Neither ISO C nor POSIX specify that the '0' flag is ignored when a
width
- and a precision are both present. But most implementations do so. */
- #ifdef __MINGW32__
- ASSERT (strcmp (result, "0x000000000303c 33") == 0 /* mingw 5 */
- || strcmp (result, " 0x000000303c 33") == 0 /* mingw 10 */);
- #else
+ /* ISO C 99 § 7.19.6.1.(6) says: "For d, i, o, u, x, and X conversions, if
a
+ precision is specified, the 0 flag is ignored." */
ASSERT (strcmp (result, " 0x000000303c 33") == 0);
- #endif
ASSERT (retval == strlen (result));
free (result);
}
