mariadb/include/mysql/service_my_snprintf.h
ParadoxV5 5100773ab9 Tag my_vsnprintf.c with ATTRIBUTE_FORMAT
[Breaking]
Good news:
GCC now checks your `my_snprintf` (direct) calls (`-Wformat` was on);
Bad news:
The build process no longer lets your incorrect
formats/arguments sneak past (`-Werror` was also on).

As such, this commit also migrates all direct `my_snprintf` calls from
the old specifiers to MDEV-21978’s new `-Wformat`-compatible suffixes.
The next commits will cover non-direct calls to `my_snprintf`.
(I call them “`my_snprintf` descendants”.)

This commit does not update the ABI records because
there’re more ABI “changes” to come – half a dozen
`include/mysql/plugin_*.h.pp`s are now missing the new `__attribute__`s.
2025-02-11 20:32:55 +01:00

124 lines
4.3 KiB
C

#ifndef MYSQL_SERVICE_MY_SNPRINTF_INCLUDED
/* Copyright (c) 2009, 2012, Oracle and/or its affiliates. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
/**
@file
my_snprintf service
Portable and limited vsnprintf() implementation.
This is a portable, limited vsnprintf() implementation, with some
extra features. "Portable" means that it'll produce identical result
on all platforms (for example, on Windows and Linux system printf %e
formats the exponent differently, on different systems %p either
prints leading 0x or not, %s may accept null pointer or crash on
it). "Limited" means that it does not support all the C89 features.
But it supports few extensions, not in any standard.
my_vsnprintf(to, n, fmt, ap)
@param[out] to A buffer to store the result in
@param[in] n Store up to n-1 characters, followed by an end 0
@param[in] fmt printf-like format string
@param[in] ap Arguments
@return a number of bytes written to a buffer *excluding* terminating '\0'
@note
The syntax of a format string is generally the same:
%[<flag>][<length>][.<precision>][<size modifier>]<format>[<format extension>]
where everything but the <format> is optional.
Two one-character <flags> are recognized:
'0' has the standard zero-padding semantics;
'-' is parsed, but silently ignored;
Both <length> and <precision> are the same as in the standard.
They can be specified as integers, or as '*' to consume an int argument.
<size modifier> can be 'l', 'll', or 'z'.
Supported <format>s are 's' (null pointer is accepted, printed as "(null)"),
'c', 'd', 'i', 'u', 'x', 'X', 'o', 'p' (works as "0x%x"), 'f', and 'g'.
The '$n' syntax for positional arguments is supported.
Format extensions:
Format 'sQ'
quotes the string with '`' (backtick)s similar to "`%s`",
but also "escapes" existing '`'s in the string to '``' as in SQL ''''.
Format 'sB'
treats the argument as a byte sequence. It reads and prints exactly
<precision> bytes without terminating on any '\0's in the sequence.
The default <precision> when it's unspecified is not defined.
Format 'sT'
replaces the end of the printed string with "..." if it was truncated.
Format 'sS'
is a synonym for 's'. It's an escape that avoid
consuming the following plain char as one of the above extension suffixes.
Example: "Data Class: %sSType"
Format 'iE'
treats the argument as an errno number. It prints this number, a space,
then its corresponding error message in double quotes. In other words:
printf("%iE", n) === printf("%i \"%sT\"", n, strerror(n))
Format 'dE' has no effect. Therefore, to escape '%iE', use '%dE' instead.
Unrecognized and multiple suffixes are not parsed;
for example, both "%sTQ" and "%iQ" will suffix with a literal 'Q'.
*/
#ifdef __cplusplus
extern "C" {
#endif
#ifndef MYSQL_ABI_CHECK
#include <stdarg.h>
#include <stdlib.h>
#endif
#include <my_attribute.h>
extern struct my_snprintf_service_st {
size_t (*my_snprintf_type)(char*, size_t, const char*, ...)
ATTRIBUTE_FORMAT_FPTR(printf, 3, 4);
size_t (*my_vsnprintf_type)(char *, size_t, const char*, va_list)
ATTRIBUTE_FORMAT_FPTR(printf, 3, 0);
} *my_snprintf_service;
#ifdef MYSQL_DYNAMIC_PLUGIN
#define my_vsnprintf my_snprintf_service->my_vsnprintf_type
#define my_snprintf my_snprintf_service->my_snprintf_type
#else
size_t my_snprintf(char* to, size_t n, const char* fmt, ...)
ATTRIBUTE_FORMAT(printf, 3, 4);
size_t my_vsnprintf(char *to, size_t n, const char* fmt, va_list ap)
ATTRIBUTE_FORMAT(printf, 3, 0);
#endif
#ifdef __cplusplus
}
#endif
#define MYSQL_SERVICE_MY_SNPRINTF_INCLUDED
#endif