gas/compress-debug.c

   1 /* compress-debug.c - compress debug sections
   2    Copyright (C) 2010-2021 Free Software Foundation, Inc.
   3
   4    This file is part of GAS, the GNU Assembler.
   5
   6    GAS is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3, or (at your option)
   9    any later version.
  10
  11    GAS is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with GAS; see the file COPYING.  If not, write to the Free
  18    Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
  19    02110-1301, USA.  */
  20
  21 #include "config.h"
  22 #include <stdio.h>
  23 #include <zlib.h>
  24 #include "ansidecl.h"
  25 #include "compress-debug.h"
  26
  27 /* Initialize the compression engine.  */
  28
  29 struct z_stream_s *
  30 compress_init (void)
  31 {
  32   static struct z_stream_s strm;
  33
  34   strm.zalloc = NULL;
  35   strm.zfree = NULL;
  36   strm.opaque = NULL;
  37   deflateInit (&strm, Z_DEFAULT_COMPRESSION);
  38   return &strm;
  39 }
  40
  41 /* Stream the contents of a frag to the compression engine.  Output
  42    from the engine goes into the current frag on the obstack.  */
  43
  44 int
  45 compress_data (struct z_stream_s *strm, const char **next_in,
  46                int *avail_in, char **next_out, int *avail_out)
  47 {
  48   int out_size = 0;
  49   int x;
  50
  51   strm->next_in = (Bytef *) (*next_in);
  52   strm->avail_in = *avail_in;
  53   strm->next_out = (Bytef *) (*next_out);
  54   strm->avail_out = *avail_out;
  55
  56   x = deflate (strm, Z_NO_FLUSH);
  57   if (x != Z_OK)
  58     return -1;
  59
  60   out_size = *avail_out - strm->avail_out;
  61   *next_in = (char *) (strm->next_in);
  62   *avail_in = strm->avail_in;
  63   *next_out = (char *) (strm->next_out);
  64   *avail_out = strm->avail_out;
  65
  66   return out_size;
  67 }
  68
  69 /* Finish the compression and consume the remaining compressed output.
  70    Returns -1 for error, 0 when done, 1 when more output buffer is
  71    needed.  */
  72
  73 int
  74 compress_finish (struct z_stream_s *strm, char **next_out,
  75                  int *avail_out, int *out_size)
  76 {
  77   int x;
  78
  79   strm->avail_in = 0;
  80   strm->next_out = (Bytef *) (*next_out);
  81   strm->avail_out = *avail_out;
  82
  83   x = deflate (strm, Z_FINISH);
  84
  85   *out_size = *avail_out - strm->avail_out;
  86   *next_out = (char *) (strm->next_out);
  87   *avail_out = strm->avail_out;
  88
  89   if (x == Z_STREAM_END)
  90     {
  91       deflateEnd (strm);
  92       return 0;
  93     }
  94   if (strm->avail_out != 0)
  95     return -1;
  96   return 1;
  97 }