forked from Imagelibrary/binutils-gdb
4a7870a831
This file is a bit of a grab-bag of dict-wide API functions like ctf_set_open_errno or ctf_errwarning_next and portabilty functions and wrappers like ctf_mmap or ctf_pread. Split the latter out, and move other dict-wide functions that got stuck in ctf-util.c (because it was so hard to tell the two files apart) into ctf-api.c where they belong.
123 lines
2.6 KiB
C
123 lines
2.6 KiB
C
/* Portability and helper wrappers.
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Copyright (C) 2019-2024 Free Software Foundation, Inc.
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This file is part of libctf.
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libctf is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 3, or (at your option) any later
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version.
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This program is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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See the GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; see the file COPYING. If not see
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<http://www.gnu.org/licenses/>. */
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#include <ctf-impl.h>
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#ifdef HAVE_MMAP
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#include <sys/mman.h>
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#endif
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#include <sys/types.h>
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#include <stdarg.h>
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#include <string.h>
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#include <unistd.h>
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/* Private, read-only mmap from a file, with fallback to copying.
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No handling of page-offset issues at all: the caller must allow for that. */
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_libctf_malloc_ void *
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ctf_mmap (size_t length, size_t offset, int fd)
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{
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void *data;
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#ifdef HAVE_MMAP
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data = mmap (NULL, length, PROT_READ, MAP_PRIVATE, fd, offset);
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if (data == MAP_FAILED)
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data = NULL;
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#else
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if ((data = malloc (length)) != NULL)
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{
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if (ctf_pread (fd, data, length, offset) <= 0)
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{
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free (data);
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data = NULL;
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}
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}
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#endif
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return data;
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}
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void
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ctf_munmap (void *buf, size_t length _libctf_unused_)
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{
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#ifdef HAVE_MMAP
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(void) munmap (buf, length);
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#else
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free (buf);
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#endif
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}
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/* pread() implementation, retrying on short reads. */
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ssize_t
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ctf_pread (int fd, void *buf, ssize_t count, off_t offset)
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{
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ssize_t len;
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size_t acc = 0;
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char *data = (char *) buf;
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#ifdef HAVE_PREAD
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while (count > 0)
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{
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errno = 0;
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if (((len = pread (fd, data, count, offset)) < 0) &&
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errno != EINTR)
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return len;
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if (errno == EINTR)
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continue;
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acc += len;
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if (len == 0) /* EOF. */
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return acc;
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count -= len;
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offset += len;
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data += len;
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}
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return acc;
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#else
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off_t orig_off;
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if ((orig_off = lseek (fd, 0, SEEK_CUR)) < 0)
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return -1;
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if ((lseek (fd, offset, SEEK_SET)) < 0)
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return -1;
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while (count > 0)
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{
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errno = 0;
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if (((len = read (fd, data, count)) < 0) &&
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errno != EINTR)
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return len;
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if (errno == EINTR)
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continue;
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acc += len;
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if (len == 0) /* EOF. */
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break;
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count -= len;
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data += len;
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}
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if ((lseek (fd, orig_off, SEEK_SET)) < 0)
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return -1; /* offset is smashed. */
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#endif
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return acc;
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}
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