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
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
|
// common.cc -- handle common symbols for gold
// Copyright 2006, 2007, 2008 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"
#include <algorithm>
#include "workqueue.h"
#include "layout.h"
#include "output.h"
#include "symtab.h"
#include "common.h"
namespace gold
{
// Allocate_commons_task methods.
// This task allocates the common symbols. We need a lock on the
// symbol table.
Task_token*
Allocate_commons_task::is_runnable()
{
if (!this->symtab_lock_->is_writable())
return this->symtab_lock_;
return NULL;
}
// Return the locks we hold: one on the symbol table, and one blocker.
void
Allocate_commons_task::locks(Task_locker* tl)
{
tl->add(this, this->blocker_);
tl->add(this, this->symtab_lock_);
}
// Allocate the common symbols.
void
Allocate_commons_task::run(Workqueue*)
{
this->symtab_->allocate_commons(this->options_, this->layout_);
}
// This class is used to sort the common symbol by size. We put the
// larger common symbols first.
template<int size>
class Sort_commons
{
public:
Sort_commons(const Symbol_table* symtab)
: symtab_(symtab)
{ }
bool operator()(const Symbol* a, const Symbol* b) const;
private:
const Symbol_table* symtab_;
};
template<int size>
bool
Sort_commons<size>::operator()(const Symbol* pa, const Symbol* pb) const
{
if (pa == NULL)
return false;
if (pb == NULL)
return true;
const Symbol_table* symtab = this->symtab_;
const Sized_symbol<size>* psa = symtab->get_sized_symbol<size>(pa);
const Sized_symbol<size>* psb = symtab->get_sized_symbol<size>(pb);
typename Sized_symbol<size>::Size_type sa = psa->symsize();
typename Sized_symbol<size>::Size_type sb = psb->symsize();
if (sa < sb)
return false;
else if (sb > sa)
return true;
// When the symbols are the same size, we sort them by alignment.
typename Sized_symbol<size>::Value_type va = psa->value();
typename Sized_symbol<size>::Value_type vb = psb->value();
if (va < vb)
return false;
else if (vb > va)
return true;
// Otherwise we stabilize the sort by sorting by name.
return strcmp(psa->name(), psb->name()) < 0;
}
// Allocate the common symbols.
void
Symbol_table::allocate_commons(const General_options& options, Layout* layout)
{
if (parameters->target().get_size() == 32)
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
this->do_allocate_commons<32>(options, layout);
#else
gold_unreachable();
#endif
}
else if (parameters->target().get_size() == 64)
{
#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
this->do_allocate_commons<64>(options, layout);
#else
gold_unreachable();
#endif
}
else
gold_unreachable();
}
// Allocated the common symbols, sized version.
template<int size>
void
Symbol_table::do_allocate_commons(const General_options&,
Layout* layout)
{
typedef typename Sized_symbol<size>::Value_type Value_type;
typedef typename Sized_symbol<size>::Size_type Size_type;
// We've kept a list of all the common symbols. But the symbol may
// have been resolved to a defined symbol by now. And it may be a
// forwarder. First remove all non-common symbols.
bool any = false;
uint64_t addralign = 0;
for (Commons_type::iterator p = this->commons_.begin();
p != this->commons_.end();
++p)
{
Symbol* sym = *p;
if (sym->is_forwarder())
{
sym = this->resolve_forwards(sym);
*p = sym;
}
if (!sym->is_common())
*p = NULL;
else
{
any = true;
Sized_symbol<size>* ssym = this->get_sized_symbol<size>(sym);
if (ssym->value() > addralign)
addralign = ssym->value();
}
}
if (!any)
return;
// Sort the common symbols by size, so that they pack better into
// memory.
std::sort(this->commons_.begin(), this->commons_.end(),
Sort_commons<size>(this));
// Place them in a newly allocated .bss section.
Output_data_space *poc = new Output_data_space(addralign);
layout->add_output_section_data(".bss", elfcpp::SHT_NOBITS,
elfcpp::SHF_WRITE | elfcpp::SHF_ALLOC,
poc);
// Allocate them all.
off_t off = 0;
for (Commons_type::iterator p = this->commons_.begin();
p != this->commons_.end();
++p)
{
Symbol* sym = *p;
if (sym == NULL)
break;
Sized_symbol<size>* ssym = this->get_sized_symbol<size>(sym);
off = align_address(off, ssym->value());
ssym->allocate_common(poc, off);
off += ssym->symsize();
}
poc->set_current_data_size(off);
this->commons_.clear();
}
} // End namespace gold.
|
