--- /dev/null
+// copy-relocs.cc -- handle COPY relocations 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 "symtab.h"
+#include "copy-relocs.h"
+
+namespace gold
+{
+
+// Copy_relocs::Copy_reloc_entry methods.
+
+// Emit the reloc if appropriate.
+
+template<int sh_type, int size, bool big_endian>
+void
+Copy_relocs<sh_type, size, big_endian>::Copy_reloc_entry::emit(
+ Output_data_reloc<sh_type, true, size, big_endian>* reloc_section)
+{
+ // If the symbol is no longer defined in a dynamic object, then we
+ // emitted a COPY relocation, and we do not want to emit this
+ // dynamic relocation.
+ if (this->sym_->is_from_dynobj())
+ reloc_section->add_global(this->sym_, this->reloc_type_,
+ this->output_section_, this->relobj_,
+ this->shndx_, this->address_,
+ this->addend_);
+}
+
+// Copy_relocs methods.
+
+// Handle a relocation against a symbol which may force us to generate
+// a COPY reloc.
+
+template<int sh_type, int size, bool big_endian>
+void
+Copy_relocs<sh_type, size, big_endian>::copy_reloc(
+ Symbol_table* symtab,
+ Layout* layout,
+ Sized_symbol<size>* sym,
+ Sized_relobj<size, big_endian>* object,
+ unsigned int shndx,
+ Output_section *output_section,
+ const Reloc& rel,
+ Output_data_reloc<sh_type, true, size, big_endian>* reloc_section)
+{
+ if (this->need_copy_reloc(sym, object, shndx))
+ this->emit_copy_reloc(symtab, layout, sym, reloc_section);
+ else
+ {
+ // We may not need a COPY relocation. Save this relocation to
+ // possibly be emitted later.
+ this->save(sym, object, shndx, output_section, rel);
+ }
+}
+
+// Return whether we need a COPY reloc for a relocation against SYM.
+// The relocation is begin applied to section SHNDX in OBJECT.
+
+template<int sh_type, int size, bool big_endian>
+bool
+Copy_relocs<sh_type, size, big_endian>::need_copy_reloc(
+ Sized_symbol<size>* sym,
+ Sized_relobj<size, big_endian>* object,
+ unsigned int shndx) const
+{
+ if (!parameters->options().copyreloc())
+ return false;
+
+ if (sym->symsize() == 0)
+ return false;
+
+ // If this is a readonly section, then we need a COPY reloc.
+ // Otherwise we can use a dynamic reloc. Note that calling
+ // section_flags here can be slow, as the information is not cached;
+ // fortunately we shouldn't see too many potential COPY relocs.
+ if ((object->section_flags(shndx) & elfcpp::SHF_WRITE) == 0)
+ return true;
+
+ return false;
+}
+
+// Emit a COPY relocation for SYM.
+
+template<int sh_type, int size, bool big_endian>
+void
+Copy_relocs<sh_type, size, big_endian>::emit_copy_reloc(
+ Symbol_table* symtab,
+ Layout* layout,
+ Sized_symbol<size>* sym,
+ Output_data_reloc<sh_type, true, size, big_endian>* reloc_section)
+{
+ // We should not be here if -z nocopyreloc is given.
+ gold_assert(parameters->options().copyreloc());
+
+ typename elfcpp::Elf_types<size>::Elf_WXword symsize = sym->symsize();
+
+ // There is no defined way to determine the required alignment of
+ // the symbol. We know that the symbol is defined in a dynamic
+ // object. We start with the alignment of the section in which it
+ // is defined; presumably we do not require an alignment larger than
+ // that. Then we reduce that alignment if the symbol is not aligned
+ // within the section.
+ gold_assert(sym->is_from_dynobj());
+ bool is_ordinary;
+ unsigned int shndx = sym->shndx(&is_ordinary);
+ gold_assert(is_ordinary);
+ typename elfcpp::Elf_types<size>::Elf_WXword addralign =
+ sym->object()->section_addralign(shndx);
+
+ typename Sized_symbol<size>::Value_type value = sym->value();
+ while ((value & (addralign - 1)) != 0)
+ addralign >>= 1;
+
+ if (this->dynbss_ == NULL)
+ {
+ this->dynbss_ = new Output_data_space(addralign, "** dynbss");
+ layout->add_output_section_data(".bss",
+ elfcpp::SHT_NOBITS,
+ elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
+ this->dynbss_);
+ }
+
+ Output_data_space* dynbss = this->dynbss_;
+
+ if (addralign > dynbss->addralign())
+ dynbss->set_space_alignment(addralign);
+
+ section_size_type dynbss_size =
+ convert_to_section_size_type(dynbss->current_data_size());
+ dynbss_size = align_address(dynbss_size, addralign);
+ section_size_type offset = dynbss_size;
+ dynbss->set_current_data_size(dynbss_size + symsize);
+
+ // Define the symbol as being copied.
+ symtab->define_with_copy_reloc(sym, dynbss, offset);
+
+ // Add the COPY relocation to the dynamic reloc section.
+ this->add_copy_reloc(sym, offset, reloc_section);
+}
+
+// Add a COPY relocation for SYM to RELOC_SECTION.
+
+template<int sh_type, int size, bool big_endian>
+void
+Copy_relocs<sh_type, size, big_endian>::add_copy_reloc(
+ Symbol* sym,
+ section_size_type offset,
+ Output_data_reloc<sh_type, true, size, big_endian>* reloc_section)
+{
+ reloc_section->add_global(sym, this->copy_reloc_type_, this->dynbss_,
+ offset, 0);
+}
+
+// Save a relocation to possibly be emitted later.
+
+template<int sh_type, int size, bool big_endian>
+void
+Copy_relocs<sh_type, size, big_endian>::save(
+ Symbol* sym,
+ Sized_relobj<size, big_endian>* object,
+ unsigned int shndx,
+ Output_section* output_section,
+ const Reloc& rel)
+{
+ unsigned int reloc_type = elfcpp::elf_r_type<size>(rel.get_r_info());
+ typename elfcpp::Elf_types<size>::Elf_Addr addend =
+ Reloc_types<sh_type, size, big_endian>::get_reloc_addend_noerror(&rel);
+ this->entries_.push_back(Copy_reloc_entry(sym, reloc_type, object, shndx,
+ output_section, rel.get_r_offset(),
+ addend));
+}
+
+// Emit any saved relocs.
+
+template<int sh_type, int size, bool big_endian>
+void
+Copy_relocs<sh_type, size, big_endian>::emit(
+ Output_data_reloc<sh_type, true, size, big_endian>* reloc_section)
+{
+ for (typename Copy_reloc_entries::iterator p = this->entries_.begin();
+ p != this->entries_.end();
+ ++p)
+ p->emit(reloc_section);
+
+ // We no longer need the saved information.
+ this->entries_.clear();
+}
+
+// Instantiate the templates we need.
+
+#ifdef HAVE_TARGET_32_LITTLE
+template
+class Copy_relocs<elfcpp::SHT_REL, 32, false>;
+
+template
+class Copy_relocs<elfcpp::SHT_RELA, 32, false>;
+#endif
+
+#ifdef HAVE_TARGET_32_BIG
+template
+class Copy_relocs<elfcpp::SHT_REL, 32, true>;
+
+template
+class Copy_relocs<elfcpp::SHT_RELA, 32, true>;
+#endif
+
+#ifdef HAVE_TARGET_64_LITTLE
+template
+class Copy_relocs<elfcpp::SHT_REL, 64, false>;
+
+template
+class Copy_relocs<elfcpp::SHT_RELA, 64, false>;
+#endif
+
+#ifdef HAVE_TARGET_64_BIG
+template
+class Copy_relocs<elfcpp::SHT_REL, 64, true>;
+
+template
+class Copy_relocs<elfcpp::SHT_RELA, 64, true>;
+#endif
+
+} // End namespace gold.
projects / msp430-binutils.git / blobdiff