1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
// compressed_output.cc -- manage compressed output sections for gold
// Copyright 2007 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
// MA 02110-1301, USA.
#include "gold.h"
#ifdef HAVE_ZLIB_H
#include <zlib.h>
#endif
#include "parameters.h"
#include "options.h"
#include "compressed_output.h"
namespace gold
{
// Compress UNCOMPRESSED_DATA of size UNCOMPRESSED_SIZE. Returns true
// if it successfully compressed, false if it failed for any reason
// (including not having zlib support in the library). If it returns
// true, it allocates memory for the compressed data using new, and
// sets *COMPRESSED_DATA and *COMPRESSED_SIZE to appropriate values.
#ifdef HAVE_ZLIB_H
static bool
zlib_compress(const char* uncompressed_data, unsigned long uncompressed_size,
char** compressed_data, unsigned long* compressed_size)
{
*compressed_size = uncompressed_size + uncompressed_size / 1000 + 128;
*compressed_data = new char[*compressed_size];
int compress_level;
if (parameters->options().optimize() >= 1)
compress_level = 9;
else
compress_level = 1;
int rc = compress2(reinterpret_cast<Bytef*>(*compressed_data),
compressed_size,
reinterpret_cast<const Bytef*>(uncompressed_data),
uncompressed_size,
compress_level);
if (rc == Z_OK)
return true;
else
{
delete[] *compressed_data;
*compressed_data = NULL;
return false;
}
}
#else // !defined(HAVE_ZLIB_H)
static bool
zlib_compress(const char*, unsigned long, char**, unsigned long*)
{
return false;
}
#endif // !defined(HAVE_ZLIB_H)
// After compressing an output section, we rename it from foo to
// foo.zlib.nnnn, where nnnn is the uncompressed size of the section.
static std::string
zlib_compressed_suffix(unsigned long uncompressed_size)
{
char size_string[64];
snprintf(size_string, sizeof(size_string), "%lu", uncompressed_size);
return std::string(".zlib.") + size_string;
}
// Class Output_compressed_section.
// Set the final data size of a compressed section. This is where
// we actually compress the section data.
void
Output_compressed_section::set_final_data_size()
{
off_t uncompressed_size = this->postprocessing_buffer_size();
// (Try to) compress the data.
unsigned long compressed_size;
unsigned char* u_uncompressed_data = this->postprocessing_buffer();
char* uncompressed_data = reinterpret_cast<char*>(u_uncompressed_data);
// At this point the contents of all regular input sections will
// have been copied into the postprocessing buffer, and relocations
// will have been applied. Now we need to copy in the contents of
// anything other than a regular input section.
this->write_to_postprocessing_buffer();
bool success = false;
if (this->options_->zlib_compress_debug_sections())
success = zlib_compress(uncompressed_data, uncompressed_size,
&this->data_, &compressed_size);
if (success)
{
std::string suffix(zlib_compressed_suffix(uncompressed_size));
this->new_section_name_ = std::string(this->name()) + suffix;
this->set_name(this->new_section_name_.c_str());
this->set_data_size(compressed_size);
}
else
{
gold_warning(_("not compressing section data: zlib error"));
gold_assert(this->data_ == NULL);
this->set_data_size(uncompressed_size);
}
}
// Write out a compressed section. If we couldn't compress, we just
// write it out as normal, uncompressed data.
void
Output_compressed_section::do_write(Output_file* of)
{
off_t offset = this->offset();
off_t data_size = this->data_size();
unsigned char* view = of->get_output_view(offset, data_size);
if (this->data_ == NULL)
memcpy(view, this->postprocessing_buffer(), data_size);
else
memcpy(view, this->data_, data_size);
of->write_output_view(offset, data_size, view);
}
} // End namespace gold.
|
