github.com/axw/llgo@v0.0.0-20160805011314-95b5fe4dca20/third_party/gofrontend/libbacktrace/posix.c (about)

     1  /* posix.c -- POSIX file I/O routines for the backtrace library.
     2     Copyright (C) 2012-2015 Free Software Foundation, Inc.
     3     Written by Ian Lance Taylor, Google.
     4  
     5  Redistribution and use in source and binary forms, with or without
     6  modification, are permitted provided that the following conditions are
     7  met:
     8  
     9      (1) Redistributions of source code must retain the above copyright
    10      notice, this list of conditions and the following disclaimer. 
    11  
    12      (2) Redistributions in binary form must reproduce the above copyright
    13      notice, this list of conditions and the following disclaimer in
    14      the documentation and/or other materials provided with the
    15      distribution.  
    16      
    17      (3) The name of the author may not be used to
    18      endorse or promote products derived from this software without
    19      specific prior written permission.
    20  
    21  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
    22  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
    23  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    24  DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
    25  INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
    26  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
    27  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    28  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
    29  STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
    30  IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    31  POSSIBILITY OF SUCH DAMAGE.  */
    32  
    33  #include "config.h"
    34  
    35  #include <errno.h>
    36  #include <sys/types.h>
    37  #include <sys/stat.h>
    38  #include <fcntl.h>
    39  #include <unistd.h>
    40  
    41  #include "backtrace.h"
    42  #include "internal.h"
    43  
    44  #ifndef O_BINARY
    45  #define O_BINARY 0
    46  #endif
    47  
    48  #ifndef O_CLOEXEC
    49  #define O_CLOEXEC 0
    50  #endif
    51  
    52  #ifndef FD_CLOEXEC
    53  #define FD_CLOEXEC 1
    54  #endif
    55  
    56  /* Open a file for reading.  */
    57  
    58  int
    59  backtrace_open (const char *filename, backtrace_error_callback error_callback,
    60  		void *data, int *does_not_exist)
    61  {
    62    int descriptor;
    63  
    64    if (does_not_exist != NULL)
    65      *does_not_exist = 0;
    66  
    67    descriptor = open (filename, O_RDONLY | O_BINARY | O_CLOEXEC);
    68    if (descriptor < 0)
    69      {
    70        if (does_not_exist != NULL && errno == ENOENT)
    71  	*does_not_exist = 1;
    72        else
    73  	error_callback (data, filename, errno);
    74        return -1;
    75      }
    76  
    77  #ifdef HAVE_FCNTL
    78    /* Set FD_CLOEXEC just in case the kernel does not support
    79       O_CLOEXEC. It doesn't matter if this fails for some reason.
    80       FIXME: At some point it should be safe to only do this if
    81       O_CLOEXEC == 0.  */
    82    fcntl (descriptor, F_SETFD, FD_CLOEXEC);
    83  #endif
    84  
    85    return descriptor;
    86  }
    87  
    88  /* Close DESCRIPTOR.  */
    89  
    90  int
    91  backtrace_close (int descriptor, backtrace_error_callback error_callback,
    92  		 void *data)
    93  {
    94    if (close (descriptor) < 0)
    95      {
    96        error_callback (data, "close", errno);
    97        return 0;
    98      }
    99    return 1;
   100  }