diff options
| -rw-r--r-- | NEWS | 3 | ||||
| -rw-r--r-- | manual/stdio.texi | 8 | ||||
| -rw-r--r-- | stdio-common/Makefile | 4 | ||||
| -rw-r--r-- | stdio-common/tst-sprintf-errno.c | 93 | ||||
| -rw-r--r-- | stdio-common/vfprintf-internal.c | 25 |
5 files changed, 125 insertions, 8 deletions
diff --git a/NEWS b/NEWS index c7200cd4e8..9294a7b953 100644 --- a/NEWS +++ b/NEWS @@ -99,6 +99,9 @@ Major new features: is set to 'madvise' mode while the latter uses the system reserved huge pages. +* 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: * On x86-64, the LD_PREFER_MAP_32BIT_EXEC environment variable support diff --git a/manual/stdio.texi b/manual/stdio.texi index 29d01b9ec9..1fac8e5f78 100644 --- a/manual/stdio.texi +++ b/manual/stdio.texi @@ -1949,6 +1949,9 @@ 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 @@ -2271,8 +2274,9 @@ 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 diff --git a/stdio-common/Makefile b/stdio-common/Makefile index bbb3a2ca56..202439117e 100644 --- a/stdio-common/Makefile +++ b/stdio-common/Makefile @@ -71,7 +71,9 @@ tests := tstscanf test_rdwr test-popen tstgetln test-fseek \ tst-printf-fp-free \ tst-printf-fp-leak \ test-strerr \ - tst-printf-binary + tst-printf-binary \ + tst-sprintf-errno \ + # tests test-srcs = tst-unbputc tst-printf tst-printfsz-islongdouble diff --git a/stdio-common/tst-sprintf-errno.c b/stdio-common/tst-sprintf-errno.c new file mode 100644 index 0000000000..7622fdbc48 --- /dev/null +++ b/stdio-common/tst-sprintf-errno.c @@ -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> diff --git a/stdio-common/vfprintf-internal.c b/stdio-common/vfprintf-internal.c index e717f50073..8547090d45 100644 --- a/stdio-common/vfprintf-internal.c +++ b/stdio-common/vfprintf-internal.c @@ -950,11 +950,26 @@ 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() \ |