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9a0910c3 ILT |
1 | // compressed_output.cc -- manage compressed output sections for gold |
2 | ||
ebdbb458 | 3 | // Copyright 2007, 2008 Free Software Foundation, Inc. |
9a0910c3 ILT |
4 | // Written by Ian Lance Taylor <iant@google.com>. |
5 | ||
6 | // This file is part of gold. | |
7 | ||
8 | // This program is free software; you can redistribute it and/or modify | |
9 | // it under the terms of the GNU General Public License as published by | |
10 | // the Free Software Foundation; either version 3 of the License, or | |
11 | // (at your option) any later version. | |
12 | ||
13 | // This program is distributed in the hope that it will be useful, | |
14 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | // GNU General Public License for more details. | |
17 | ||
18 | // You should have received a copy of the GNU General Public License | |
19 | // along with this program; if not, write to the Free Software | |
20 | // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, | |
21 | // MA 02110-1301, USA. | |
22 | ||
23 | #include "gold.h" | |
24 | ||
25 | #ifdef HAVE_ZLIB_H | |
26 | #include <zlib.h> | |
27 | #endif | |
28 | ||
9a0910c3 | 29 | #include "parameters.h" |
14144f39 | 30 | #include "options.h" |
96803768 | 31 | #include "compressed_output.h" |
9a0910c3 ILT |
32 | |
33 | namespace gold | |
34 | { | |
35 | ||
36 | // Compress UNCOMPRESSED_DATA of size UNCOMPRESSED_SIZE. Returns true | |
37 | // if it successfully compressed, false if it failed for any reason | |
38 | // (including not having zlib support in the library). If it returns | |
39 | // true, it allocates memory for the compressed data using new, and | |
40 | // sets *COMPRESSED_DATA and *COMPRESSED_SIZE to appropriate values. | |
41 | ||
b589a5bc ILT |
42 | #ifdef HAVE_ZLIB_H |
43 | ||
9a0910c3 ILT |
44 | static bool |
45 | zlib_compress(const char* uncompressed_data, unsigned long uncompressed_size, | |
46 | char** compressed_data, unsigned long* compressed_size) | |
47 | { | |
9a0910c3 ILT |
48 | *compressed_size = uncompressed_size + uncompressed_size / 1000 + 128; |
49 | *compressed_data = new char[*compressed_size]; | |
50 | ||
51 | int compress_level; | |
8851ecca | 52 | if (parameters->options().optimize() >= 1) |
9a0910c3 ILT |
53 | compress_level = 9; |
54 | else | |
55 | compress_level = 1; | |
56 | ||
57 | int rc = compress2(reinterpret_cast<Bytef*>(*compressed_data), | |
58 | compressed_size, | |
59 | reinterpret_cast<const Bytef*>(uncompressed_data), | |
60 | uncompressed_size, | |
61 | compress_level); | |
62 | if (rc == Z_OK) | |
63 | return true; | |
64 | else | |
65 | { | |
66 | delete[] *compressed_data; | |
67 | *compressed_data = NULL; | |
68 | return false; | |
69 | } | |
9a0910c3 ILT |
70 | } |
71 | ||
b589a5bc ILT |
72 | #else // !defined(HAVE_ZLIB_H) |
73 | ||
74 | static bool | |
75 | zlib_compress(const char*, unsigned long, char**, unsigned long*) | |
76 | { | |
77 | return false; | |
78 | } | |
79 | ||
80 | #endif // !defined(HAVE_ZLIB_H) | |
81 | ||
9a0910c3 ILT |
82 | // After compressing an output section, we rename it from foo to |
83 | // foo.zlib.nnnn, where nnnn is the uncompressed size of the section. | |
84 | ||
85 | static std::string | |
86 | zlib_compressed_suffix(unsigned long uncompressed_size) | |
87 | { | |
88 | char size_string[64]; | |
89 | snprintf(size_string, sizeof(size_string), "%lu", uncompressed_size); | |
90 | return std::string(".zlib.") + size_string; | |
91 | } | |
92 | ||
96803768 | 93 | // Class Output_compressed_section. |
9a0910c3 ILT |
94 | |
95 | // Set the final data size of a compressed section. This is where | |
96 | // we actually compress the section data. | |
97 | ||
98 | void | |
96803768 | 99 | Output_compressed_section::set_final_data_size() |
9a0910c3 | 100 | { |
96803768 | 101 | off_t uncompressed_size = this->postprocessing_buffer_size(); |
9a0910c3 ILT |
102 | |
103 | // (Try to) compress the data. | |
104 | unsigned long compressed_size; | |
96803768 ILT |
105 | unsigned char* u_uncompressed_data = this->postprocessing_buffer(); |
106 | char* uncompressed_data = reinterpret_cast<char*>(u_uncompressed_data); | |
107 | ||
108 | // At this point the contents of all regular input sections will | |
109 | // have been copied into the postprocessing buffer, and relocations | |
110 | // will have been applied. Now we need to copy in the contents of | |
111 | // anything other than a regular input section. | |
112 | this->write_to_postprocessing_buffer(); | |
9a0910c3 ILT |
113 | |
114 | bool success = false; | |
ee1fe73e | 115 | if (strcmp(this->options_->compress_debug_sections(), "zlib") == 0) |
9a0910c3 ILT |
116 | success = zlib_compress(uncompressed_data, uncompressed_size, |
117 | &this->data_, &compressed_size); | |
118 | if (success) | |
119 | { | |
96803768 ILT |
120 | std::string suffix(zlib_compressed_suffix(uncompressed_size)); |
121 | this->new_section_name_ = std::string(this->name()) + suffix; | |
122 | this->set_name(this->new_section_name_.c_str()); | |
9a0910c3 | 123 | this->set_data_size(compressed_size); |
9a0910c3 ILT |
124 | } |
125 | else | |
126 | { | |
96803768 | 127 | gold_warning(_("not compressing section data: zlib error")); |
9a0910c3 | 128 | gold_assert(this->data_ == NULL); |
9a0910c3 ILT |
129 | this->set_data_size(uncompressed_size); |
130 | } | |
131 | } | |
132 | ||
9a0910c3 ILT |
133 | // Write out a compressed section. If we couldn't compress, we just |
134 | // write it out as normal, uncompressed data. | |
135 | ||
136 | void | |
96803768 | 137 | Output_compressed_section::do_write(Output_file* of) |
9a0910c3 | 138 | { |
96803768 ILT |
139 | off_t offset = this->offset(); |
140 | off_t data_size = this->data_size(); | |
141 | unsigned char* view = of->get_output_view(offset, data_size); | |
142 | if (this->data_ == NULL) | |
143 | memcpy(view, this->postprocessing_buffer(), data_size); | |
9a0910c3 | 144 | else |
96803768 ILT |
145 | memcpy(view, this->data_, data_size); |
146 | of->write_output_view(offset, data_size, view); | |
9a0910c3 ILT |
147 | } |
148 | ||
9a0910c3 | 149 | } // End namespace gold. |