--- /dev/null
+// 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 "mapfile.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->layout_, this->mapfile_);
+}
+
+// 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);
+
+ // Sort by largest size first.
+ 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,
+ // largest alignment first.
+ 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(Layout* layout, Mapfile* mapfile)
+{
+ if (parameters->target().get_size() == 32)
+ {
+#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
+ this->do_allocate_commons<32>(layout, mapfile);
+#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>(layout, mapfile);
+#else
+ gold_unreachable();
+#endif
+ }
+ else
+ gold_unreachable();
+}
+
+// Allocated the common symbols, sized version.
+
+template<int size>
+void
+Symbol_table::do_allocate_commons(Layout* layout, Mapfile* mapfile)
+{
+ if (!this->commons_.empty())
+ this->do_allocate_commons_list<size>(layout, COMMONS_NORMAL,
+ &this->commons_, mapfile);
+ if (!this->tls_commons_.empty())
+ this->do_allocate_commons_list<size>(layout, COMMONS_TLS,
+ &this->tls_commons_, mapfile);
+ if (!this->small_commons_.empty())
+ this->do_allocate_commons_list<size>(layout, COMMONS_SMALL,
+ &this->small_commons_, mapfile);
+ if (!this->large_commons_.empty())
+ this->do_allocate_commons_list<size>(layout, COMMONS_LARGE,
+ &this->large_commons_, mapfile);
+}
+
+// Allocate the common symbols in a list. IS_TLS indicates whether
+// these are TLS common symbols.
+
+template<int size>
+void
+Symbol_table::do_allocate_commons_list(
+ Layout* layout,
+ Commons_section_type commons_section_type,
+ Commons_type* commons,
+ Mapfile* mapfile)
+{
+ 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 = commons->begin();
+ p != 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(commons->begin(), commons->end(),
+ Sort_commons<size>(this));
+
+ // Place them in a newly allocated BSS section.
+ elfcpp::Elf_Xword flags = elfcpp::SHF_WRITE | elfcpp::SHF_ALLOC;
+ const char* name;
+ const char* ds_name;
+ switch (commons_section_type)
+ {
+ case COMMONS_NORMAL:
+ name = ".bss";
+ ds_name = "** common";
+ break;
+ case COMMONS_TLS:
+ flags |= elfcpp::SHF_TLS;
+ name = ".tbss";
+ ds_name = "** tls common";
+ break;
+ case COMMONS_SMALL:
+ flags |= parameters->target().small_common_section_flags();
+ name = ".sbss";
+ ds_name = "** small common";
+ break;
+ case COMMONS_LARGE:
+ flags |= parameters->target().large_common_section_flags();
+ name = ".lbss";
+ ds_name = "** large common";
+ break;
+ default:
+ gold_unreachable();
+ }
+
+ Output_data_space *poc = new Output_data_space(addralign, ds_name);
+ Output_section *os = layout->add_output_section_data(name,
+ elfcpp::SHT_NOBITS,
+ flags, poc);
+ if (os != NULL)
+ {
+ if (commons_section_type == COMMONS_SMALL)
+ os->set_is_small_section();
+ else if (commons_section_type == COMMONS_LARGE)
+ os->set_is_large_section();
+ }
+
+ // Allocate them all.
+
+ off_t off = 0;
+ for (Commons_type::iterator p = commons->begin();
+ p != commons->end();
+ ++p)
+ {
+ Symbol* sym = *p;
+ if (sym == NULL)
+ break;
+ Sized_symbol<size>* ssym = this->get_sized_symbol<size>(sym);
+
+ // Record the symbol in the map file now, before we change its
+ // value. Pass the size in separately so that we don't have to
+ // templatize the map code, which is not performance sensitive.
+ if (mapfile != NULL)
+ mapfile->report_allocate_common(sym, ssym->symsize());
+
+ off = align_address(off, ssym->value());
+ ssym->allocate_common(poc, off);
+ off += ssym->symsize();
+ }
+
+ poc->set_current_data_size(off);
+
+ commons->clear();
+}
+
+} // End namespace gold.
projects / msp430-binutils.git / blobdiff