btrfs-progs/common/messages.h
Julien Olivain 9fdb8d7469 btrfs-progs: add uClibc-ng compatibility for printf format %pV
Commit [1] 164bc10d "btrfs-progs: add musl compatibility for printf
format %pV" added a logic to detect the presence of the glibc
<printf.h> header, and if present, to use the
register_printf_specifier() and register_printf_modifier() functions.

The original intent (as the commit log suggests), was to support the
musl libc, which does not provides this <printf.h> header.

When compiling with another libc, such as uClibc-ng, btrfs-progs fail
to build with error:

    common/messages.c: In function 'print_va_format':
    common/messages.c:51:19: error: 'const struct printf_info' has no member named 'user'
       51 |         if (!(info->user & va_modifier))
          |                   ^~
    common/messages.c: In function 'btrfs_no_printk':
    common/messages.c:76:17: warning: implicit declaration of function 'register_printf_specifier'; did you mean 'register_printf_function'? [-Wimplicit-function-declaration]
       76 |                 register_printf_specifier('V', print_va_format,
          |                 ^~~~~~~~~~~~~~~~~~~~~~~~~
          |                 register_printf_function
    common/messages.c:78:31: warning: implicit declaration of function 'register_printf_modifier'; did you mean 'register_printf_function'? [-Wimplicit-function-declaration]
       78 |                 va_modifier = register_printf_modifier(L"p");
          |                               ^~~~~~~~~~~~~~~~~~~~~~~~
          |                               register_printf_function

This is because uClibc-ng provides a <printf.h> header, but not the
register_printf_specifier() and register_printf_modifier() functions.
See [2]. It mainly includes register_printf_function(). uClibc-ng
emulates an older glibc behavior. Glibc added support for printf user
elements in commit [3] (first included in glibc-2.10, in 2009). Checking
only the <printf.h> is not sufficient.

This commit fixes this build issue by refining the detection logic of
the <printf.h> functions required by btrfs-progs.

[1] 164bc10dfc
[2] https://gogs.waldemar-brodkorb.de/oss/uclibc-ng/src/v1.0.49/include/printf.h
[3] https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=9d26efa90c6dcbcd6b3e586c9927b6058ef4d529

Pull-request: #843
Signed-off-by: Julien Olivain <ju.o@free.fr>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-07-30 19:53:33 +02:00

204 lines
5.3 KiB
C

/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#ifndef __BTRFS_MESSAGES_H__
#define __BTRFS_MESSAGES_H__
#include "kerncompat.h"
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
/*
* Workaround for custom format %pV that may not be supported on all libcs.
*/
#if defined(HAVE_PRINTF_H) \
&& defined(HAVE_REGISTER_PRINTF_SPECIFIER) \
&& defined(HAVE_REGISTER_PRINTF_MODIFIER)
#define DECLARE_PV(name) struct va_format name
#define PV_FMT "%pV"
#define PV_VAL(va) &va
#define PV_ASSIGN(_va, _fmt, _args) ({ _va.fmt = (_fmt); _va.va = &(_args); })
#include <printf.h>
#else
#define PV_WORKAROUND
#define DECLARE_PV(name) char name[1024]
#define PV_FMT "%s"
#define PV_VAL(va) va
#define PV_ASSIGN(_va, _fmt, _args) vsnprintf(_va, 1024, _fmt, _args)
#endif
#ifdef DEBUG_VERBOSE_ERROR
#define PRINT_VERBOSE_ERROR fprintf(stderr, "%s:%d:", __FILE__, __LINE__)
#else
#define PRINT_VERBOSE_ERROR
#endif
#ifdef DEBUG_TRACE_ON_ERROR
#define PRINT_TRACE_ON_ERROR print_trace()
#else
#define PRINT_TRACE_ON_ERROR do { } while (0)
#endif
#ifdef DEBUG_ABORT_ON_ERROR
#define DO_ABORT_ON_ERROR abort()
#else
#define DO_ABORT_ON_ERROR do { } while (0)
#endif
#ifndef BTRFS_DISABLE_BACKTRACE
static inline void assert_trace(const char *assertion, const char *filename,
const char *func, unsigned line, long val)
{
if (val)
return;
fprintf(stderr,
"%s:%d: %s: Assertion `%s` failed, value %ld\n",
filename, line, func, assertion, val);
#ifndef BTRFS_DISABLE_BACKTRACE
print_trace();
#endif
abort();
exit(1);
}
#define UASSERT(c) assert_trace(#c, __FILE__, __func__, __LINE__, (long)(c))
#else
#define UASSERT(c) assert(c)
#endif
#define PREFIX_ERROR "ERROR: "
#define PREFIX_WARNING "WARNING: "
#define __btrfs_msg(prefix, fmt, ...) \
do { \
fputs((prefix), stderr); \
__btrfs_printf((fmt), ##__VA_ARGS__); \
fputc('\n', stderr); \
} while (0)
#define __btrfs_warning(fmt, ...) \
__btrfs_msg(PREFIX_WARNING, fmt, ##__VA_ARGS__)
#define __btrfs_error(fmt, ...) \
__btrfs_msg(PREFIX_ERROR, fmt, ##__VA_ARGS__)
#define internal_error(fmt, ...) \
do { \
__btrfs_msg("INTERNAL " PREFIX_ERROR, fmt, ##__VA_ARGS__); \
print_trace(); \
} while (0)
#define error(fmt, ...) \
do { \
PRINT_TRACE_ON_ERROR; \
PRINT_VERBOSE_ERROR; \
__btrfs_error((fmt), ##__VA_ARGS__); \
DO_ABORT_ON_ERROR; \
} while (0)
#define error_on(cond, fmt, ...) \
do { \
if ((cond)) { \
PRINT_TRACE_ON_ERROR; \
PRINT_VERBOSE_ERROR; \
__btrfs_error((fmt), ##__VA_ARGS__); \
DO_ABORT_ON_ERROR; \
} \
} while (0)
#define error_btrfs_util(err) \
do { \
const char *errno_str = strerror(errno); \
const char *lib_str = btrfs_util_strerror(err); \
PRINT_TRACE_ON_ERROR; \
PRINT_VERBOSE_ERROR; \
if (lib_str && strcmp(errno_str, lib_str) != 0) \
__btrfs_error("%s: %m", lib_str); \
else \
__btrfs_error("%m"); \
DO_ABORT_ON_ERROR; \
} while (0)
#define warning(fmt, ...) \
do { \
PRINT_TRACE_ON_ERROR; \
PRINT_VERBOSE_ERROR; \
__btrfs_warning((fmt), ##__VA_ARGS__); \
} while (0)
#define warning_on(cond, fmt, ...) \
do { \
if ((cond)) { \
PRINT_TRACE_ON_ERROR; \
PRINT_VERBOSE_ERROR; \
__btrfs_warning((fmt), ##__VA_ARGS__); \
} \
} while (0)
__attribute__ ((format (printf, 1, 2)))
void __btrfs_printf(const char *fmt, ...);
__attribute__ ((format (printf, 2, 3)))
void btrfs_no_printk(const void *fs_info, const char *fmt, ...);
/*
* Level of messages that must be printed by default (in case the verbosity
* options haven't been set by the user) due to backward compatibility reasons
* where applications may expect the output.
*/
#define LOG_ALWAYS (-1)
/*
* Default level for any messages that should be printed by default, a one line
* summary or with more details. Applications should not rely on such messages.
*/
#define LOG_DEFAULT (1)
/*
* Information about the ongoing actions, high level description
*/
#define LOG_INFO (2)
/*
* Verbose description and individual steps of the previous level
*/
#define LOG_VERBOSE (3)
/*
* Anything that should not be normally printed but can be useful for debugging
*/
#define LOG_DEBUG (4)
__attribute__ ((format (printf, 2, 3)))
void pr_verbose(int level, const char *fmt, ...);
__attribute__ ((format (printf, 2, 3)))
void pr_stderr(int level, const char *fmt, ...);
/*
* Commonly used errors
*/
enum common_error {
ERROR_MSG_MEMORY,
ERROR_MSG_START_TRANS,
ERROR_MSG_COMMIT_TRANS,
ERROR_MSG_UNEXPECTED,
ERROR_MSG_READ,
ERROR_MSG_WRITE,
};
__attribute__ ((format (printf, 2, 3)))
void error_msg(enum common_error error, const char *msg, ...);
#endif