1 // common.cc -- handle common symbols for gold
3 // Copyright 2006, 2007 Free Software Foundation, Inc.
6 // This file is part of gold.
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.
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.
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.
27 #include "workqueue.h"
36 // Allocate_commons_task methods.
38 // This task allocates the common symbols. We need a lock on the
41 Task::Is_runnable_type
42 Allocate_commons_task::is_runnable(Workqueue*)
44 if (!this->symtab_lock_->is_writable())
49 // Return the locks we hold: one on the symbol table, and one blocker.
51 class Allocate_commons_task::Allocate_commons_locker : public Task_locker
54 Allocate_commons_locker(Task_token& symtab_lock, Task* task,
55 Task_token& blocker, Workqueue* workqueue)
56 : symtab_locker_(symtab_lock, task),
57 blocker_(blocker, workqueue)
61 Task_locker_write symtab_locker_;
62 Task_locker_block blocker_;
66 Allocate_commons_task::locks(Workqueue* workqueue)
68 return new Allocate_commons_locker(*this->symtab_lock_, this,
69 *this->blocker_, workqueue);
72 // Allocate the common symbols.
75 Allocate_commons_task::run(Workqueue*)
77 this->symtab_->allocate_commons(this->options_, this->layout_);
80 // This class is used to sort the common symbol by size. We put the
81 // larger common symbols first.
87 Sort_commons(const Symbol_table* symtab)
91 bool operator()(const Symbol* a, const Symbol* b) const;
94 const Symbol_table* symtab_;
99 Sort_commons<size>::operator()(const Symbol* pa, const Symbol* pb) const
106 const Symbol_table* symtab = this->symtab_;
107 const Sized_symbol<size>* psa;
108 psa = symtab->get_sized_symbol SELECT_SIZE_NAME(size) (pa
110 const Sized_symbol<size>* psb;
111 psb = symtab->get_sized_symbol SELECT_SIZE_NAME(size) (pb
114 typename Sized_symbol<size>::Size_type sa = psa->symsize();
115 typename Sized_symbol<size>::Size_type sb = psb->symsize();
121 // When the symbols are the same size, we sort them by alignment.
122 typename Sized_symbol<size>::Value_type va = psa->value();
123 typename Sized_symbol<size>::Value_type vb = psb->value();
129 // Otherwise we stabilize the sort by sorting by name.
130 return strcmp(psa->name(), psb->name()) < 0;
133 // Allocate the common symbols.
136 Symbol_table::allocate_commons(const General_options& options, Layout* layout)
138 if (parameters->get_size() == 32)
140 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
141 this->do_allocate_commons<32>(options, layout);
146 else if (parameters->get_size() == 64)
148 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
149 this->do_allocate_commons<64>(options, layout);
158 // Allocated the common symbols, sized version.
162 Symbol_table::do_allocate_commons(const General_options&,
165 typedef typename Sized_symbol<size>::Value_type Value_type;
166 typedef typename Sized_symbol<size>::Size_type Size_type;
168 // We've kept a list of all the common symbols. But the symbol may
169 // have been resolved to a defined symbol by now. And it may be a
170 // forwarder. First remove all non-common symbols.
172 uint64_t addralign = 0;
173 for (Commons_type::iterator p = this->commons_.begin();
174 p != this->commons_.end();
178 if (sym->is_forwarder())
180 sym = this->resolve_forwards(sym);
183 if (!sym->is_common())
188 Sized_symbol<size>* ssym;
189 ssym = this->get_sized_symbol SELECT_SIZE_NAME(size) (
192 if (ssym->value() > addralign)
193 addralign = ssym->value();
199 // Sort the common symbols by size, so that they pack better into
201 std::sort(this->commons_.begin(), this->commons_.end(),
202 Sort_commons<size>(this));
204 // Place them in a newly allocated .bss section.
206 Output_data_space *poc = new Output_data_space(addralign);
208 layout->add_output_section_data(".bss", elfcpp::SHT_NOBITS,
209 elfcpp::SHF_WRITE | elfcpp::SHF_ALLOC,
212 // Allocate them all.
215 for (Commons_type::iterator p = this->commons_.begin();
216 p != this->commons_.end();
223 Sized_symbol<size>* ssym;
224 ssym = this->get_sized_symbol SELECT_SIZE_NAME(size) (sym
227 off = align_address(off, ssym->value());
229 ssym->allocate_common(poc, off);
231 off += ssym->symsize();
234 poc->set_space_size(off);
236 this->commons_.clear();
239 } // End namespace gold.