1 /* printf implementation for the dynamic loader.
2 Copyright (C) 1997-2024 Free Software Foundation, Inc.
3 Copyright The GNU Toolchain Authors.
4 This file is part of the GNU C Library.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
22 # pragma GCC visibility push(hidden)
26 #include <dl-writev.h>
36 /* The function might be called before the process is self-relocated. */
38 _dl_debug_strlen (const char *s)
41 for (; *s != '\0'; s++);
45 /* Bare-bones printf implementation. This function only knows about
46 the formats and flags needed and can handle only up to 64 stripes in
49 _dl_debug_vdprintf (int fd, int tag_p, const char *fmt, va_list arg)
52 struct iovec iov[NIOVMAX];
53 /* Maximum size for 'd', 'u', and 'x' including padding. */
54 enum { IFMTSIZE = INT_STRLEN_BOUND(void *) };
55 char ifmtbuf[NIOVMAX][IFMTSIZE];
62 const char *startp = fmt;
66 /* Generate the tag line once. It consists of the PID and a
67 colon followed by a tab. */
72 assert (pid >= 0 && sizeof (pid_t) <= 4);
73 p = _itoa (pid, &pidbuf[10], 10, 0);
80 /* Append to the output. */
81 assert (niov < NIOVMAX);
82 iov[niov].iov_len = 12;
83 iov[niov++].iov_base = pidbuf;
85 /* No more tags until we see the next newline. */
89 /* Skip everything except % and \n (if tags are needed). */
90 while (*fmt != '\0' && *fmt != '%' && (! tag_p || *fmt != '\n'))
93 /* Append constant string. */
94 assert (niov < NIOVMAX);
95 if ((iov[niov].iov_len = fmt - startp) != 0)
96 iov[niov++].iov_base = (char *) startp;
100 /* It is a format specifier. */
104 #if LONG_MAX != INT_MAX
108 /* Recognize zero-digit fill flag. */
115 /* See whether with comes from a parameter. Note that no other
116 way to specify the width is implemented. */
119 width = va_arg (arg, int);
120 /* The maximum padding accepted is up to pointer size. */
121 assert (width < IFMTSIZE);
125 /* Handle precision. */
126 if (*fmt == '.' && fmt[1] == '*')
128 prec = va_arg (arg, int);
132 /* Recognize the l modifier. It is only important on some
133 platforms where long and int have a different size. We
134 can use the same code for size_t. */
135 if (*fmt == 'l' || *fmt == 'z')
137 #if LONG_MAX != INT_MAX
145 /* Integer formatting. */
150 /* We have to make a difference if long and int have a
152 #if LONG_MAX != INT_MAX
153 unsigned long int num = (long_mod
154 ? va_arg (arg, unsigned long int)
155 : va_arg (arg, unsigned int));
157 unsigned long int num = va_arg (arg, unsigned int);
159 bool negative = false;
162 #if LONG_MAX != INT_MAX
165 if ((long int) num < 0)
175 num = -(unsigned int) num;
188 char *endp = &ifmtbuf[niov][IFMTSIZE];
189 char *cp = _itoa (num, endp, *fmt == 'x' ? 16 : 10, 0);
191 /* Pad to the width the user specified. */
193 while (endp - cp < width)
199 iov[niov].iov_base = cp;
200 iov[niov].iov_len = endp - cp;
206 /* Get the string argument. */
207 iov[niov].iov_base = va_arg (arg, char *);
208 iov[niov].iov_len = _dl_debug_strlen (iov[niov].iov_base);
210 iov[niov].iov_len = MIN ((size_t) prec, iov[niov].iov_len);
215 iov[niov].iov_base = (void *) fmt;
216 iov[niov].iov_len = 1;
221 assert (! "invalid format specifier");
225 else if (*fmt == '\n')
227 /* See whether we have to print a single newline character. */
230 iov[niov].iov_base = (char *) startp;
231 iov[niov++].iov_len = 1;
234 /* No, just add it to the rest of the string. */
235 ++iov[niov - 1].iov_len;
237 /* Next line, print a tag again. */
243 /* Finally write the result. */
244 _dl_writev (fd, iov, niov);
248 /* Write to debug file. */
250 _dl_debug_printf (const char *fmt, ...)
255 _dl_debug_vdprintf (GLRO(dl_debug_fd), 1, fmt, arg);
260 /* Write to debug file but don't start with a tag. */
262 _dl_debug_printf_c (const char *fmt, ...)
267 _dl_debug_vdprintf (GLRO(dl_debug_fd), -1, fmt, arg);
272 /* Write the given file descriptor. */
274 _dl_dprintf (int fd, const char *fmt, ...)
279 _dl_debug_vdprintf (fd, 0, fmt, arg);
284 _dl_printf (const char *fmt, ...)
289 _dl_debug_vdprintf (STDOUT_FILENO, 0, fmt, arg);
294 _dl_error_printf (const char *fmt, ...)
299 _dl_debug_vdprintf (STDERR_FILENO, 0, fmt, arg);
304 _dl_fatal_printf (const char *fmt, ...)
309 _dl_debug_vdprintf (STDERR_FILENO, 0, fmt, arg);
313 rtld_hidden_def (_dl_fatal_printf)