@@ -64,6 +64,9 @@ Major new features:
to be used by compilers for optimizing usage of 'memcmp' when its
return value is only used for its boolean status.
+* The printf family of functions now handles the flagged %#m conversion
+ specifier, printing errno as an error constant (similar to strerrorname_np).
+
Deprecated and removed features, and other changes affecting compatibility:
* The r_version update in the debugger interface makes the glibc binary
@@ -1938,6 +1938,9 @@ which can be parsed by the @code{strtoul} function (@pxref{Parsing of
Integers}) and @code{scanf} with the @samp{%i} conversion
(@pxref{Numeric Input Conversions}).
+For the @samp{%m} conversion, print an error constant or decimal error
+number, instead of a (possibly translated) error message.
+
@item @samp{'}
Separate the digits into groups as specified by the locale specified for
the @code{LC_NUMERIC} category; @pxref{General Numeric}. This flag is a
@@ -2259,8 +2262,9 @@ is equivalent to:
fprintf (stderr, "can't open `%s': %s\n", filename, strerror (errno));
@end smallexample
-@noindent
-The @samp{%m} conversion is a @glibcadj{} extension.
+The @samp{%m} conversion can be used with the @samp{#} flag to print an
+error constant, as provided by @code{strerrorname_np}. Both @samp{%m}
+and @samp{%#m} are @glibcadj{} extensions.
The @samp{%p} conversion prints a pointer value. The corresponding
argument must be of type @code{void *}. In practice, you can use any
@@ -70,7 +70,9 @@ tests := tstscanf test_rdwr test-popen tstgetln test-fseek \
tst-vfprintf-width-prec-alloc \
tst-printf-fp-free \
tst-printf-fp-leak \
- test-strerr
+ test-strerr \
+ tst-sprintf-errno \
+ # tests
test-srcs = tst-unbputc tst-printf tst-printfsz-islongdouble
new file mode 100644
@@ -0,0 +1,93 @@
+/* Test the %m, %#m printf specifiers via asprintf.
+ Copyright (C) 2021 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C 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 2.1 of the License, or (at your option) any later version.
+
+ The GNU C 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 C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <errno.h>
+#include <libc-diag.h>
+#include <stdio.h>
+#include <support/check.h>
+#include <support/support.h>
+
+/* GCC does not yet know about the %#m specifier. */
+DIAG_PUSH_NEEDS_COMMENT;
+DIAG_IGNORE_NEEDS_COMMENT (11, "-Wformat=");
+
+static int
+do_test (void)
+{
+ char buf[64];
+
+ errno = EINVAL;
+ TEST_COMPARE (sprintf (buf, "%m"), 16);
+ TEST_COMPARE_STRING (buf, "Invalid argument");
+
+ errno = EINVAL;
+ TEST_COMPARE (sprintf (buf, "%#m"), 6);
+ TEST_COMPARE_STRING (buf, "EINVAL");
+
+ errno = 0;
+ TEST_COMPARE (sprintf (buf, "%m"), 7);
+ TEST_COMPARE_STRING (buf, "Success");
+
+ errno = 0;
+ TEST_COMPARE (sprintf (buf, "%#m"), 1);
+ TEST_COMPARE_STRING (buf, "0");
+
+ errno = -1;
+ TEST_COMPARE (sprintf (buf, "%m"), 16);
+ TEST_COMPARE_STRING (buf, "Unknown error -1");
+
+ errno = -1;
+ TEST_COMPARE (sprintf (buf, "%#m"), 2);
+ TEST_COMPARE_STRING (buf, "-1");
+
+ errno = 1002003;
+ TEST_COMPARE (sprintf (buf, "%m"), 21);
+ TEST_COMPARE_STRING (buf, "Unknown error 1002003");
+
+ errno = 1002003;
+ TEST_COMPARE (sprintf (buf, "%#m"), 7);
+ TEST_COMPARE_STRING (buf, "1002003");
+
+ errno = EINVAL;
+ TEST_COMPARE (sprintf (buf, "%20m"), 20);
+ TEST_COMPARE_STRING (buf, " Invalid argument");
+
+ errno = EINVAL;
+ TEST_COMPARE (sprintf (buf, "%#20m"), 20);
+ TEST_COMPARE_STRING (buf, " EINVAL");
+
+ errno = EINVAL;
+ TEST_COMPARE (sprintf (buf, "%-20m"), 20);
+ TEST_COMPARE_STRING (buf, "Invalid argument ");
+
+ errno = EINVAL;
+ TEST_COMPARE (sprintf (buf, "%-#20m"), 20);
+ TEST_COMPARE_STRING (buf, "EINVAL ");
+
+ errno = 0;
+ TEST_COMPARE (sprintf (buf, "%-20m"), 20);
+ TEST_COMPARE_STRING (buf, "Success ");
+
+ errno = 0;
+ TEST_COMPARE (sprintf (buf, "%-#20m"), 20);
+ TEST_COMPARE_STRING (buf, "0 ");
+
+ return 0;
+}
+
+#include <support/test-driver.c>
@@ -936,11 +936,26 @@ static const uint8_t jump_table[] =
\
LABEL (form_strerror): \
/* Print description of error ERRNO. */ \
- string = \
- (CHAR_T *) __strerror_r (save_errno, (char *) work_buffer, \
- WORK_BUFFER_SIZE * sizeof (CHAR_T)); \
- is_long = 0; /* This is no wide-char string. */ \
- goto LABEL (print_string)
+ if (alt) \
+ string = (CHAR_T *) __get_errname (save_errno); \
+ else \
+ string = (CHAR_T *) __strerror_r (save_errno, (char *) work_buffer, \
+ WORK_BUFFER_SIZE * sizeof (CHAR_T));\
+ if (string == NULL) \
+ { \
+ /* Print as a decimal number. */ \
+ base = 10; \
+ is_negative = save_errno < 0; \
+ number.word = save_errno; \
+ if (is_negative) \
+ number.word = -number.word; \
+ goto LABEL (number); \
+ } \
+ else \
+ { \
+ is_long = 0; /* This is no wide-char string. */ \
+ goto LABEL (print_string); \
+ }
#ifdef COMPILE_WPRINTF
# define process_string_arg() \