1 /* printf implementation for the dynamic loader.
2 Copyright (C) 1997-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
21 #include <dl-writev.h>
32 /* Bare-bones printf implementation. This function only knows about
33 the formats and flags needed and can handle only up to 64 stripes in
36 _dl_debug_vdprintf (int fd, int tag_p, const char *fmt, va_list arg)
39 struct iovec iov[NIOVMAX];
40 /* Maximum size for 'd', 'u', and 'x' including padding. */
41 enum { IFMTSIZE = INT_STRLEN_BOUND(void *) };
42 char ifmtbuf[NIOVMAX][IFMTSIZE];
49 const char *startp = fmt;
53 /* Generate the tag line once. It consists of the PID and a
54 colon followed by a tab. */
59 assert (pid >= 0 && sizeof (pid_t) <= 4);
60 p = _itoa (pid, &pidbuf[10], 10, 0);
67 /* Append to the output. */
68 assert (niov < NIOVMAX);
69 iov[niov].iov_len = 12;
70 iov[niov++].iov_base = pidbuf;
72 /* No more tags until we see the next newline. */
76 /* Skip everything except % and \n (if tags are needed). */
77 while (*fmt != '\0' && *fmt != '%' && (! tag_p || *fmt != '\n'))
80 /* Append constant string. */
81 assert (niov < NIOVMAX);
82 if ((iov[niov].iov_len = fmt - startp) != 0)
83 iov[niov++].iov_base = (char *) startp;
87 /* It is a format specifier. */
91 #if LONG_MAX != INT_MAX
95 /* Recognize zero-digit fill flag. */
102 /* See whether with comes from a parameter. Note that no other
103 way to specify the width is implemented. */
106 width = va_arg (arg, int);
107 /* The maximum padding accepted is up to pointer size. */
108 assert (width < IFMTSIZE);
112 /* Handle precision. */
113 if (*fmt == '.' && fmt[1] == '*')
115 prec = va_arg (arg, int);
119 /* Recognize the l modifier. It is only important on some
120 platforms where long and int have a different size. We
121 can use the same code for size_t. */
122 if (*fmt == 'l' || *fmt == 'z')
124 #if LONG_MAX != INT_MAX
132 /* Integer formatting. */
137 /* We have to make a difference if long and int have a
139 #if LONG_MAX != INT_MAX
140 unsigned long int num = (long_mod
141 ? va_arg (arg, unsigned long int)
142 : va_arg (arg, unsigned int));
144 unsigned long int num = va_arg (arg, unsigned int);
146 bool negative = false;
149 #if LONG_MAX != INT_MAX
152 if ((long int) num < 0)
159 num = (unsigned int) num;
169 char *endp = &ifmtbuf[niov][IFMTSIZE];
170 char *cp = _itoa (num, endp, *fmt == 'x' ? 16 : 10, 0);
172 /* Pad to the width the user specified. */
174 while (endp - cp < width)
180 iov[niov].iov_base = cp;
181 iov[niov].iov_len = endp - cp;
187 /* Get the string argument. */
188 iov[niov].iov_base = va_arg (arg, char *);
189 iov[niov].iov_len = strlen (iov[niov].iov_base);
191 iov[niov].iov_len = MIN ((size_t) prec, iov[niov].iov_len);
196 iov[niov].iov_base = (void *) fmt;
197 iov[niov].iov_len = 1;
202 assert (! "invalid format specifier");
206 else if (*fmt == '\n')
208 /* See whether we have to print a single newline character. */
211 iov[niov].iov_base = (char *) startp;
212 iov[niov++].iov_len = 1;
215 /* No, just add it to the rest of the string. */
216 ++iov[niov - 1].iov_len;
218 /* Next line, print a tag again. */
224 /* Finally write the result. */
225 _dl_writev (fd, iov, niov);
229 /* Write to debug file. */
231 _dl_debug_printf (const char *fmt, ...)
236 _dl_debug_vdprintf (GLRO(dl_debug_fd), 1, fmt, arg);
241 /* Write to debug file but don't start with a tag. */
243 _dl_debug_printf_c (const char *fmt, ...)
248 _dl_debug_vdprintf (GLRO(dl_debug_fd), -1, fmt, arg);
253 /* Write the given file descriptor. */
255 _dl_dprintf (int fd, const char *fmt, ...)
260 _dl_debug_vdprintf (fd, 0, fmt, arg);
265 _dl_printf (const char *fmt, ...)
270 _dl_debug_vdprintf (STDOUT_FILENO, 0, fmt, arg);
275 _dl_error_printf (const char *fmt, ...)
280 _dl_debug_vdprintf (STDERR_FILENO, 0, fmt, arg);
285 _dl_fatal_printf (const char *fmt, ...)
290 _dl_debug_vdprintf (STDERR_FILENO, 0, fmt, arg);
294 rtld_hidden_def (_dl_fatal_printf)