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581c785bf3
I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 7061 files FOO. I then removed trailing white space from math/tgmath.h, support/tst-support-open-dev-null-range.c, and sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following obscure pre-commit check failure diagnostics from Savannah. I don't know why I run into these diagnostics whereas others evidently do not. remote: *** 912-#endif remote: *** 913: remote: *** 914- remote: *** error: lines with trailing whitespace found ... remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
274 lines
7.3 KiB
C
274 lines
7.3 KiB
C
/* Minimal replacements for basic facilities used in the dynamic linker.
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Copyright (C) 1995-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <assert.h>
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#include <ldsodefs.h>
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#include <dl-irel.h>
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#include <dl-hash.h>
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#include <dl-sym-post.h>
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#include <_itoa.h>
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#include <dl-minimal-malloc.h>
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#include <stdio.h>
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#include <unistd.h>
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/* The rtld startup code calls __rtld_malloc_init_stubs after the
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first self-relocation to adjust the pointers to the minimal
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implementation below. Before the final relocation,
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__rtld_malloc_init_real is called to replace the pointers with the
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real implementation. */
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__typeof (calloc) *__rtld_calloc attribute_relro;
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__typeof (free) *__rtld_free attribute_relro;
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__typeof (malloc) *__rtld_malloc attribute_relro;
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__typeof (realloc) *__rtld_realloc attribute_relro;
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void
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__rtld_malloc_init_stubs (void)
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{
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__rtld_calloc = &__minimal_calloc;
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__rtld_free = &__minimal_free;
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__rtld_malloc = &__minimal_malloc;
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__rtld_realloc = &__minimal_realloc;
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}
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bool
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__rtld_malloc_is_complete (void)
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{
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/* The caller assumes that there is an active malloc. */
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assert (__rtld_malloc != NULL);
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return __rtld_malloc != &__minimal_malloc;
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}
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/* Lookup NAME at VERSION in the scope of MATCH. */
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static void *
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lookup_malloc_symbol (struct link_map *main_map, const char *name,
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struct r_found_version *version)
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{
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const ElfW(Sym) *ref = NULL;
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lookup_t result = _dl_lookup_symbol_x (name, main_map, &ref,
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main_map->l_scope,
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version, 0, 0, NULL);
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assert (ELFW(ST_TYPE) (ref->st_info) != STT_TLS);
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void *value = DL_SYMBOL_ADDRESS (result, ref);
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return _dl_sym_post (result, ref, value, 0, main_map);
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}
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void
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__rtld_malloc_init_real (struct link_map *main_map)
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{
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/* We cannot use relocations and initializers for this because the
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changes made by __rtld_malloc_init_stubs break REL-style
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(non-RELA) relocations that depend on the previous pointer
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contents. Also avoid direct relocation depedencies for the
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malloc symbols so this function can be called before the final
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rtld relocation (which enables RELRO, after which the pointer
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variables cannot be written to). */
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struct r_found_version version;
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version.name = symbol_version_string (libc, GLIBC_2_0);
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version.hidden = 0;
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version.hash = _dl_elf_hash (version.name);
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version.filename = NULL;
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void *new_calloc = lookup_malloc_symbol (main_map, "calloc", &version);
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void *new_free = lookup_malloc_symbol (main_map, "free", &version);
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void *new_malloc = lookup_malloc_symbol (main_map, "malloc", &version);
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void *new_realloc = lookup_malloc_symbol (main_map, "realloc", &version);
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/* Update the pointers in one go, so that any internal allocations
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performed by lookup_malloc_symbol see a consistent
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implementation. */
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__rtld_calloc = new_calloc;
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__rtld_free = new_free;
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__rtld_malloc = new_malloc;
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__rtld_realloc = new_realloc;
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}
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/* Avoid signal frobnication in setjmp/longjmp. Keeps things smaller. */
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#include <setjmp.h>
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int weak_function
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__sigjmp_save (sigjmp_buf env, int savemask __attribute__ ((unused)))
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{
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env[0].__mask_was_saved = 0;
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return 0;
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}
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/* Define our own version of the internal function used by strerror. We
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only provide the messages for some common errors. This avoids pulling
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in the whole error list. */
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char * weak_function
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__strerror_r (int errnum, char *buf, size_t buflen)
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{
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char *msg;
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switch (errnum)
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{
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case ENOMEM:
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msg = (char *) "Cannot allocate memory";
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break;
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case EINVAL:
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msg = (char *) "Invalid argument";
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break;
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case ENOENT:
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msg = (char *) "No such file or directory";
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break;
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case EPERM:
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msg = (char *) "Operation not permitted";
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break;
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case EIO:
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msg = (char *) "Input/output error";
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break;
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case EACCES:
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msg = (char *) "Permission denied";
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break;
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default:
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/* No need to check buffer size, all calls in the dynamic linker
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provide enough space. */
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buf[buflen - 1] = '\0';
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msg = _itoa (errnum, buf + buflen - 1, 10, 0);
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msg = memcpy (msg - (sizeof ("Error ") - 1), "Error ",
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sizeof ("Error ") - 1);
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break;
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}
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return msg;
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}
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void
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__libc_fatal (const char *message)
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{
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_dl_fatal_printf ("%s", message);
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}
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rtld_hidden_def (__libc_fatal)
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void
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__attribute__ ((noreturn))
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__chk_fail (void)
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{
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_exit (127);
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}
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rtld_hidden_def (__chk_fail)
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#ifndef NDEBUG
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/* Define (weakly) our own assert failure function which doesn't use stdio.
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If we are linked into the user program (-ldl), the normal __assert_fail
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defn can override this one. */
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void weak_function
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__assert_fail (const char *assertion,
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const char *file, unsigned int line, const char *function)
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{
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_dl_fatal_printf ("\
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Inconsistency detected by ld.so: %s: %u: %s%sAssertion `%s' failed!\n",
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file, line, function ?: "", function ? ": " : "",
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assertion);
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}
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# ifndef NO_RTLD_HIDDEN
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rtld_hidden_weak (__assert_fail)
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# endif
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void weak_function
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__assert_perror_fail (int errnum,
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const char *file, unsigned int line,
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const char *function)
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{
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char errbuf[400];
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_dl_fatal_printf ("\
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Inconsistency detected by ld.so: %s: %u: %s%sUnexpected error: %s.\n",
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file, line, function ?: "", function ? ": " : "",
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__strerror_r (errnum, errbuf, sizeof errbuf));
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}
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# ifndef NO_RTLD_HIDDEN
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rtld_hidden_weak (__assert_perror_fail)
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# endif
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#endif
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#undef _itoa
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/* We always use _itoa instead of _itoa_word in ld.so since the former
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also has to be present and it is never about speed when these
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functions are used. */
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char *
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_itoa (unsigned long long int value, char *buflim, unsigned int base,
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int upper_case)
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{
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assert (! upper_case);
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do
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*--buflim = _itoa_lower_digits[value % base];
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while ((value /= base) != 0);
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return buflim;
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}
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/* The '_itoa_lower_digits' variable in libc.so is able to handle bases
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up to 36. We don't need this here. */
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const char _itoa_lower_digits[16] = "0123456789abcdef";
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rtld_hidden_data_def (_itoa_lower_digits)
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/* The following is not a complete strsep implementation. It cannot
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handle empty delimiter strings. But this isn't necessary for the
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execution of ld.so. */
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#undef strsep
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#undef __strsep
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char *
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__strsep (char **stringp, const char *delim)
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{
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char *begin;
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assert (delim[0] != '\0');
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begin = *stringp;
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if (begin != NULL)
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{
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char *end = begin;
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while (*end != '\0' || (end = NULL))
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{
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const char *dp = delim;
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do
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if (*dp == *end)
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break;
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while (*++dp != '\0');
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if (*dp != '\0')
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{
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*end++ = '\0';
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break;
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}
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++end;
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}
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*stringp = end;
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}
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return begin;
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}
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weak_alias (__strsep, strsep)
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strong_alias (__strsep, __strsep_g)
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