gdb/target/target-utils.c

   1 /* Utility target functions for GDB, and GDBserver.
   2
   3    Copyright (C) 2015 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "common-defs.h"
  21 #include "target/target-utils.h"
  22
  23 LONGEST
  24 read_alloc (gdb_byte **buf_p, int handle, read_alloc_pread_ftype *pread_func,
  25             int padding)
  26 {
  27   size_t buf_alloc, buf_pos;
  28   gdb_byte *buf;
  29   LONGEST n;
  30   int target_errno;
  31
  32   /* Start by reading up to 4K at a time.  The target will throttle
  33      this number down if necessary.  */
  34   buf_alloc = 4096;
  35   buf = xmalloc (buf_alloc);
  36   buf_pos = 0;
  37   while (1)
  38     {
  39       n = pread_func (handle, &buf[buf_pos], buf_alloc - buf_pos - padding,
  40                       buf_pos, &target_errno);
  41       if (n <= 0)
  42         {
  43           if (n < 0 || (n == 0 && buf_pos == 0))
  44             xfree (buf);
  45           else
  46             *buf_p = buf;
  47           if (n < 0)
  48             {
  49               /* An error occurred.  */
  50               return -1;
  51             }
  52           else
  53             {
  54               /* Read all there was.  */
  55               return buf_pos;
  56             }
  57         }
  58
  59       buf_pos += n;
  60
  61       /* If the buffer is filling up, expand it.  */
  62       if (buf_alloc < buf_pos * 2)
  63         {
  64           buf_alloc *= 2;
  65           buf = xrealloc (buf, buf_alloc);
  66         }
  67     }
  68 }
  69
  70 char *
  71 read_stralloc (struct inferior *inf, const char *filename,
  72                read_stralloc_func_ftype *func)
  73 {
  74   gdb_byte *buffer;
  75   char *bufstr;
  76   LONGEST i, transferred;
  77
  78   transferred = func (inf, filename, &buffer, 1);
  79   bufstr = (char *) buffer;
  80
  81   if (transferred < 0)
  82     return NULL;
  83
  84   if (transferred == 0)
  85     return xstrdup ("");
  86
  87   bufstr[transferred] = 0;
  88
  89   /* Check for embedded NUL bytes; but allow trailing NULs.  */
  90   for (i = strlen (bufstr); i < transferred; i++)
  91     if (bufstr[i] != 0)
  92       {
  93         warning (_("target file %s "
  94                    "contained unexpected null characters"),
  95                  filename);
  96         break;
  97       }
  98
  99   return bufstr;
 100 }