a67858e046
* parameters.cc (Parameters::entry): Return target-specific entry symbol name. * target.h (Target::entry_symbol_name): New function. (Target_info::entry_symbol_name): New data member. * arm.cc (Target_arm::arm_info): Add entry_symbol_name. (Target_arm_nacl::arm_nacl_info): Likewise. * i386.cc (Target_i386::i386_info): Likewise. (Target_i386_nacl::i386_nacl_info): Likewise. * powerpc.cc (Target_powerpc::powerpc_info): Likewise. * sparc.cc (Target_sparc::sparc_info): Likewise. * tilegx.cc (Target_tilegx::tilegx_info): Likewise. * x86_64.cc: (Target_x86_64::x86_64_info) Likewise. (Target_x86_64_nacl::x86_64_nacl_info) Likewise. * testsuite/testfile.cc (Target_test::test_target_info): Likewise.
1037 lines
36 KiB
C++
1037 lines
36 KiB
C++
// target.h -- target support for gold -*- C++ -*-
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// Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012
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// Free Software Foundation, Inc.
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// Written by Ian Lance Taylor <iant@google.com>.
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// This file is part of gold.
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// This program is free software; you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation; either version 3 of the License, or
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// (at your option) any later version.
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// You should have received a copy of the GNU General Public License
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// along with this program; if not, write to the Free Software
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// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
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// MA 02110-1301, USA.
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// The abstract class Target is the interface for target specific
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// support. It defines abstract methods which each target must
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// implement. Typically there will be one target per processor, but
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// in some cases it may be necessary to have subclasses.
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// For speed and consistency we want to use inline functions to handle
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// relocation processing. So besides implementations of the abstract
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// methods, each target is expected to define a template
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// specialization of the relocation functions.
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#ifndef GOLD_TARGET_H
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#define GOLD_TARGET_H
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#include "elfcpp.h"
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#include "options.h"
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#include "parameters.h"
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#include "debug.h"
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namespace gold
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{
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class Object;
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class Relobj;
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template<int size, bool big_endian>
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class Sized_relobj;
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template<int size, bool big_endian>
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class Sized_relobj_file;
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class Relocatable_relocs;
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template<int size, bool big_endian>
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struct Relocate_info;
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class Reloc_symbol_changes;
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class Symbol;
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template<int size>
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class Sized_symbol;
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class Symbol_table;
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class Output_data;
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class Output_data_got_base;
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class Output_section;
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class Input_objects;
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class Task;
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struct Symbol_location;
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// The abstract class for target specific handling.
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class Target
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{
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public:
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virtual ~Target()
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{ }
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// Return the bit size that this target implements. This should
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// return 32 or 64.
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int
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get_size() const
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{ return this->pti_->size; }
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// Return whether this target is big-endian.
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bool
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is_big_endian() const
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{ return this->pti_->is_big_endian; }
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// Machine code to store in e_machine field of ELF header.
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elfcpp::EM
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machine_code() const
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{ return this->pti_->machine_code; }
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// Processor specific flags to store in e_flags field of ELF header.
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elfcpp::Elf_Word
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processor_specific_flags() const
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{ return this->processor_specific_flags_; }
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// Whether processor specific flags are set at least once.
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bool
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are_processor_specific_flags_set() const
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{ return this->are_processor_specific_flags_set_; }
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// Whether this target has a specific make_symbol function.
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bool
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has_make_symbol() const
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{ return this->pti_->has_make_symbol; }
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// Whether this target has a specific resolve function.
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bool
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has_resolve() const
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{ return this->pti_->has_resolve; }
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// Whether this target has a specific code fill function.
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bool
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has_code_fill() const
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{ return this->pti_->has_code_fill; }
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// Return the default name of the dynamic linker.
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const char*
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dynamic_linker() const
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{ return this->pti_->dynamic_linker; }
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// Return the default address to use for the text segment.
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uint64_t
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default_text_segment_address() const
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{ return this->pti_->default_text_segment_address; }
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// Return the ABI specified page size.
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uint64_t
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abi_pagesize() const
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{
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if (parameters->options().max_page_size() > 0)
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return parameters->options().max_page_size();
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else
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return this->pti_->abi_pagesize;
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}
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// Return the common page size used on actual systems.
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uint64_t
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common_pagesize() const
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{
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if (parameters->options().common_page_size() > 0)
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return std::min(parameters->options().common_page_size(),
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this->abi_pagesize());
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else
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return std::min(this->pti_->common_pagesize,
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this->abi_pagesize());
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}
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// Return whether PF_X segments must contain nothing but the contents of
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// SHF_EXECINSTR sections (no non-executable data, no headers).
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bool
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isolate_execinstr() const
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{ return this->pti_->isolate_execinstr; }
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uint64_t
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rosegment_gap() const
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{ return this->pti_->rosegment_gap; }
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// If we see some object files with .note.GNU-stack sections, and
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// some objects files without them, this returns whether we should
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// consider the object files without them to imply that the stack
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// should be executable.
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bool
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is_default_stack_executable() const
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{ return this->pti_->is_default_stack_executable; }
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// Return a character which may appear as a prefix for a wrap
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// symbol. If this character appears, we strip it when checking for
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// wrapping and add it back when forming the final symbol name.
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// This should be '\0' if not special prefix is required, which is
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// the normal case.
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char
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wrap_char() const
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{ return this->pti_->wrap_char; }
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// Return the special section index which indicates a small common
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// symbol. This will return SHN_UNDEF if there are no small common
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// symbols.
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elfcpp::Elf_Half
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small_common_shndx() const
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{ return this->pti_->small_common_shndx; }
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// Return values to add to the section flags for the section holding
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// small common symbols.
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elfcpp::Elf_Xword
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small_common_section_flags() const
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{
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gold_assert(this->pti_->small_common_shndx != elfcpp::SHN_UNDEF);
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return this->pti_->small_common_section_flags;
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}
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// Return the special section index which indicates a large common
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// symbol. This will return SHN_UNDEF if there are no large common
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// symbols.
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elfcpp::Elf_Half
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large_common_shndx() const
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{ return this->pti_->large_common_shndx; }
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// Return values to add to the section flags for the section holding
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// large common symbols.
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elfcpp::Elf_Xword
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large_common_section_flags() const
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{
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gold_assert(this->pti_->large_common_shndx != elfcpp::SHN_UNDEF);
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return this->pti_->large_common_section_flags;
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}
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// This hook is called when an output section is created.
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void
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new_output_section(Output_section* os) const
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{ this->do_new_output_section(os); }
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// This is called to tell the target to complete any sections it is
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// handling. After this all sections must have their final size.
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void
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finalize_sections(Layout* layout, const Input_objects* input_objects,
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Symbol_table* symtab)
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{ return this->do_finalize_sections(layout, input_objects, symtab); }
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// Return the value to use for a global symbol which needs a special
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// value in the dynamic symbol table. This will only be called if
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// the backend first calls symbol->set_needs_dynsym_value().
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uint64_t
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dynsym_value(const Symbol* sym) const
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{ return this->do_dynsym_value(sym); }
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// Return a string to use to fill out a code section. This is
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// basically one or more NOPS which must fill out the specified
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// length in bytes.
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std::string
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code_fill(section_size_type length) const
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{ return this->do_code_fill(length); }
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// Return whether SYM is known to be defined by the ABI. This is
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// used to avoid inappropriate warnings about undefined symbols.
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bool
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is_defined_by_abi(const Symbol* sym) const
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{ return this->do_is_defined_by_abi(sym); }
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// Adjust the output file header before it is written out. VIEW
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// points to the header in external form. LEN is the length.
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void
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adjust_elf_header(unsigned char* view, int len) const
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{ return this->do_adjust_elf_header(view, len); }
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// Return address and size to plug into eh_frame FDEs associated with a PLT.
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void
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plt_fde_location(const Output_data* plt, unsigned char* oview,
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uint64_t* address, off_t* len) const
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{ return this->do_plt_fde_location(plt, oview, address, len); }
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// Return whether NAME is a local label name. This is used to implement the
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// --discard-locals options.
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bool
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is_local_label_name(const char* name) const
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{ return this->do_is_local_label_name(name); }
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// Get the symbol index to use for a target specific reloc.
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unsigned int
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reloc_symbol_index(void* arg, unsigned int type) const
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{ return this->do_reloc_symbol_index(arg, type); }
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// Get the addend to use for a target specific reloc.
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uint64_t
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reloc_addend(void* arg, unsigned int type, uint64_t addend) const
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{ return this->do_reloc_addend(arg, type, addend); }
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// Return the PLT address to use for a global symbol.
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uint64_t
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plt_address_for_global(const Symbol* sym) const
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{ return this->do_plt_address_for_global(sym); }
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// Return the PLT address to use for a local symbol.
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uint64_t
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plt_address_for_local(const Relobj* object, unsigned int symndx) const
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{ return this->do_plt_address_for_local(object, symndx); }
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// Return the offset to use for the GOT_INDX'th got entry which is
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// for a local tls symbol specified by OBJECT, SYMNDX.
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int64_t
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tls_offset_for_local(const Relobj* object,
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unsigned int symndx,
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unsigned int got_indx) const
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{ return do_tls_offset_for_local(object, symndx, got_indx); }
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// Return the offset to use for the GOT_INDX'th got entry which is
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// for global tls symbol GSYM.
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int64_t
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tls_offset_for_global(Symbol* gsym, unsigned int got_indx) const
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{ return do_tls_offset_for_global(gsym, got_indx); }
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// For targets that use function descriptors, if LOC is the location
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// of a function, modify it to point at the function entry location.
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void
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function_location(Symbol_location* loc) const
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{ return do_function_location(loc); }
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// Return whether this target can use relocation types to determine
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// if a function's address is taken.
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bool
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can_check_for_function_pointers() const
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{ return this->do_can_check_for_function_pointers(); }
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// Return whether a relocation to a merged section can be processed
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// to retrieve the contents.
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bool
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can_icf_inline_merge_sections () const
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{ return this->pti_->can_icf_inline_merge_sections; }
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// Whether a section called SECTION_NAME may have function pointers to
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// sections not eligible for safe ICF folding.
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virtual bool
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section_may_have_icf_unsafe_pointers(const char* section_name) const
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{ return this->do_section_may_have_icf_unsafe_pointers(section_name); }
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// Return the base to use for the PC value in an FDE when it is
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// encoded using DW_EH_PE_datarel. This does not appear to be
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// documented anywhere, but it is target specific. Any use of
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// DW_EH_PE_datarel in gcc requires defining a special macro
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// (ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX) to output the value.
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uint64_t
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ehframe_datarel_base() const
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{ return this->do_ehframe_datarel_base(); }
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// Return true if a reference to SYM from a reloc of type R_TYPE
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// means that the current function may call an object compiled
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// without -fsplit-stack. SYM is known to be defined in an object
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// compiled without -fsplit-stack.
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bool
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is_call_to_non_split(const Symbol* sym, unsigned int r_type) const
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{ return this->do_is_call_to_non_split(sym, r_type); }
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// A function starts at OFFSET in section SHNDX in OBJECT. That
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// function was compiled with -fsplit-stack, but it refers to a
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// function which was compiled without -fsplit-stack. VIEW is a
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// modifiable view of the section; VIEW_SIZE is the size of the
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// view. The target has to adjust the function so that it allocates
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// enough stack.
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void
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calls_non_split(Relobj* object, unsigned int shndx,
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section_offset_type fnoffset, section_size_type fnsize,
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unsigned char* view, section_size_type view_size,
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std::string* from, std::string* to) const
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{
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this->do_calls_non_split(object, shndx, fnoffset, fnsize, view, view_size,
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from, to);
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}
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// Make an ELF object.
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template<int size, bool big_endian>
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Object*
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make_elf_object(const std::string& name, Input_file* input_file,
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off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr)
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{ return this->do_make_elf_object(name, input_file, offset, ehdr); }
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// Make an output section.
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Output_section*
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make_output_section(const char* name, elfcpp::Elf_Word type,
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elfcpp::Elf_Xword flags)
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{ return this->do_make_output_section(name, type, flags); }
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// Return true if target wants to perform relaxation.
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bool
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may_relax() const
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{
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// Run the dummy relaxation pass twice if relaxation debugging is enabled.
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if (is_debugging_enabled(DEBUG_RELAXATION))
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return true;
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return this->do_may_relax();
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}
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// Perform a relaxation pass. Return true if layout may be changed.
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bool
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relax(int pass, const Input_objects* input_objects, Symbol_table* symtab,
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Layout* layout, const Task* task)
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{
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// Run the dummy relaxation pass twice if relaxation debugging is enabled.
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if (is_debugging_enabled(DEBUG_RELAXATION))
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return pass < 2;
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return this->do_relax(pass, input_objects, symtab, layout, task);
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}
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// Return the target-specific name of attributes section. This is
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// NULL if a target does not use attributes section or if it uses
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// the default section name ".gnu.attributes".
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const char*
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attributes_section() const
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{ return this->pti_->attributes_section; }
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// Return the vendor name of vendor attributes.
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const char*
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attributes_vendor() const
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{ return this->pti_->attributes_vendor; }
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// Whether a section called NAME is an attribute section.
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bool
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is_attributes_section(const char* name) const
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{
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return ((this->pti_->attributes_section != NULL
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&& strcmp(name, this->pti_->attributes_section) == 0)
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|| strcmp(name, ".gnu.attributes") == 0);
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}
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// Return a bit mask of argument types for attribute with TAG.
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int
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attribute_arg_type(int tag) const
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{ return this->do_attribute_arg_type(tag); }
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// Return the attribute tag of the position NUM in the list of fixed
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// attributes. Normally there is no reordering and
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// attributes_order(NUM) == NUM.
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int
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attributes_order(int num) const
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{ return this->do_attributes_order(num); }
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// When a target is selected as the default target, we call this method,
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// which may be used for expensive, target-specific initialization.
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void
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select_as_default_target()
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{ this->do_select_as_default_target(); }
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// Return the value to store in the EI_OSABI field in the ELF
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// header.
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elfcpp::ELFOSABI
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osabi() const
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{ return this->osabi_; }
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// Set the value to store in the EI_OSABI field in the ELF header.
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void
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set_osabi(elfcpp::ELFOSABI osabi)
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{ this->osabi_ = osabi; }
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// Define target-specific standard symbols.
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void
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define_standard_symbols(Symbol_table* symtab, Layout* layout)
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{ this->do_define_standard_symbols(symtab, layout); }
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// Return the output section name to use given an input section
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// name, or NULL if no target specific name mapping is required.
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// Set *PLEN to the length of the name if returning non-NULL.
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const char*
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output_section_name(const Relobj* relobj,
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const char* name,
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size_t* plen) const
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{ return this->do_output_section_name(relobj, name, plen); }
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// Add any special sections for this symbol to the gc work list.
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void
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gc_mark_symbol(Symbol_table* symtab, Symbol* sym) const
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{ this->do_gc_mark_symbol(symtab, sym); }
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// Return the name of the entry point symbol.
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const char*
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entry_symbol_name() const
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{ return this->pti_->entry_symbol_name; }
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protected:
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// This struct holds the constant information for a child class. We
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// use a struct to avoid the overhead of virtual function calls for
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// simple information.
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struct Target_info
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{
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// Address size (32 or 64).
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int size;
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// Whether the target is big endian.
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bool is_big_endian;
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// The code to store in the e_machine field of the ELF header.
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elfcpp::EM machine_code;
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// Whether this target has a specific make_symbol function.
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bool has_make_symbol;
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// Whether this target has a specific resolve function.
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bool has_resolve;
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// Whether this target has a specific code fill function.
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bool has_code_fill;
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// Whether an object file with no .note.GNU-stack sections implies
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// that the stack should be executable.
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bool is_default_stack_executable;
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// Whether a relocation to a merged section can be processed to
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// retrieve the contents.
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bool can_icf_inline_merge_sections;
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// Prefix character to strip when checking for wrapping.
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char wrap_char;
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// The default dynamic linker name.
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const char* dynamic_linker;
|
|
// The default text segment address.
|
|
uint64_t default_text_segment_address;
|
|
// The ABI specified page size.
|
|
uint64_t abi_pagesize;
|
|
// The common page size used by actual implementations.
|
|
uint64_t common_pagesize;
|
|
// Whether PF_X segments must contain nothing but the contents of
|
|
// SHF_EXECINSTR sections (no non-executable data, no headers).
|
|
bool isolate_execinstr;
|
|
// If nonzero, distance from the text segment to the read-only segment.
|
|
uint64_t rosegment_gap;
|
|
// The special section index for small common symbols; SHN_UNDEF
|
|
// if none.
|
|
elfcpp::Elf_Half small_common_shndx;
|
|
// The special section index for large common symbols; SHN_UNDEF
|
|
// if none.
|
|
elfcpp::Elf_Half large_common_shndx;
|
|
// Section flags for small common section.
|
|
elfcpp::Elf_Xword small_common_section_flags;
|
|
// Section flags for large common section.
|
|
elfcpp::Elf_Xword large_common_section_flags;
|
|
// Name of attributes section if it is not ".gnu.attributes".
|
|
const char* attributes_section;
|
|
// Vendor name of vendor attributes.
|
|
const char* attributes_vendor;
|
|
// Name of the main entry point to the program.
|
|
const char* entry_symbol_name;
|
|
};
|
|
|
|
Target(const Target_info* pti)
|
|
: pti_(pti), processor_specific_flags_(0),
|
|
are_processor_specific_flags_set_(false), osabi_(elfcpp::ELFOSABI_NONE)
|
|
{ }
|
|
|
|
// Virtual function which may be implemented by the child class.
|
|
virtual void
|
|
do_new_output_section(Output_section*) const
|
|
{ }
|
|
|
|
// Virtual function which may be implemented by the child class.
|
|
virtual void
|
|
do_finalize_sections(Layout*, const Input_objects*, Symbol_table*)
|
|
{ }
|
|
|
|
// Virtual function which may be implemented by the child class.
|
|
virtual uint64_t
|
|
do_dynsym_value(const Symbol*) const
|
|
{ gold_unreachable(); }
|
|
|
|
// Virtual function which must be implemented by the child class if
|
|
// needed.
|
|
virtual std::string
|
|
do_code_fill(section_size_type) const
|
|
{ gold_unreachable(); }
|
|
|
|
// Virtual function which may be implemented by the child class.
|
|
virtual bool
|
|
do_is_defined_by_abi(const Symbol*) const
|
|
{ return false; }
|
|
|
|
// Adjust the output file header before it is written out. VIEW
|
|
// points to the header in external form. LEN is the length, and
|
|
// will be one of the values of elfcpp::Elf_sizes<size>::ehdr_size.
|
|
// By default, we set the EI_OSABI field if requested (in
|
|
// Sized_target).
|
|
virtual void
|
|
do_adjust_elf_header(unsigned char*, int) const = 0;
|
|
|
|
// Return address and size to plug into eh_frame FDEs associated with a PLT.
|
|
virtual void
|
|
do_plt_fde_location(const Output_data* plt, unsigned char* oview,
|
|
uint64_t* address, off_t* len) const;
|
|
|
|
// Virtual function which may be overridden by the child class.
|
|
virtual bool
|
|
do_is_local_label_name(const char*) const;
|
|
|
|
// Virtual function that must be overridden by a target which uses
|
|
// target specific relocations.
|
|
virtual unsigned int
|
|
do_reloc_symbol_index(void*, unsigned int) const
|
|
{ gold_unreachable(); }
|
|
|
|
// Virtual function that must be overridden by a target which uses
|
|
// target specific relocations.
|
|
virtual uint64_t
|
|
do_reloc_addend(void*, unsigned int, uint64_t) const
|
|
{ gold_unreachable(); }
|
|
|
|
// Virtual functions that must be overridden by a target that uses
|
|
// STT_GNU_IFUNC symbols.
|
|
virtual uint64_t
|
|
do_plt_address_for_global(const Symbol*) const
|
|
{ gold_unreachable(); }
|
|
|
|
virtual uint64_t
|
|
do_plt_address_for_local(const Relobj*, unsigned int) const
|
|
{ gold_unreachable(); }
|
|
|
|
virtual int64_t
|
|
do_tls_offset_for_local(const Relobj*, unsigned int, unsigned int) const
|
|
{ gold_unreachable(); }
|
|
|
|
virtual int64_t
|
|
do_tls_offset_for_global(Symbol*, unsigned int) const
|
|
{ gold_unreachable(); }
|
|
|
|
virtual void
|
|
do_function_location(Symbol_location*) const = 0;
|
|
|
|
// Virtual function which may be overriden by the child class.
|
|
virtual bool
|
|
do_can_check_for_function_pointers() const
|
|
{ return false; }
|
|
|
|
// Virtual function which may be overridden by the child class. We
|
|
// recognize some default sections for which we don't care whether
|
|
// they have function pointers.
|
|
virtual bool
|
|
do_section_may_have_icf_unsafe_pointers(const char* section_name) const
|
|
{
|
|
// We recognize sections for normal vtables, construction vtables and
|
|
// EH frames.
|
|
return (!is_prefix_of(".rodata._ZTV", section_name)
|
|
&& !is_prefix_of(".data.rel.ro._ZTV", section_name)
|
|
&& !is_prefix_of(".rodata._ZTC", section_name)
|
|
&& !is_prefix_of(".data.rel.ro._ZTC", section_name)
|
|
&& !is_prefix_of(".eh_frame", section_name));
|
|
}
|
|
|
|
virtual uint64_t
|
|
do_ehframe_datarel_base() const
|
|
{ gold_unreachable(); }
|
|
|
|
// Virtual function which may be overridden by the child class. The
|
|
// default implementation is that any function not defined by the
|
|
// ABI is a call to a non-split function.
|
|
virtual bool
|
|
do_is_call_to_non_split(const Symbol* sym, unsigned int) const;
|
|
|
|
// Virtual function which may be overridden by the child class.
|
|
virtual void
|
|
do_calls_non_split(Relobj* object, unsigned int, section_offset_type,
|
|
section_size_type, unsigned char*, section_size_type,
|
|
std::string*, std::string*) const;
|
|
|
|
// make_elf_object hooks. There are four versions of these for
|
|
// different address sizes and endianness.
|
|
|
|
// Set processor specific flags.
|
|
void
|
|
set_processor_specific_flags(elfcpp::Elf_Word flags)
|
|
{
|
|
this->processor_specific_flags_ = flags;
|
|
this->are_processor_specific_flags_set_ = true;
|
|
}
|
|
|
|
#ifdef HAVE_TARGET_32_LITTLE
|
|
// Virtual functions which may be overridden by the child class.
|
|
virtual Object*
|
|
do_make_elf_object(const std::string&, Input_file*, off_t,
|
|
const elfcpp::Ehdr<32, false>&);
|
|
#endif
|
|
|
|
#ifdef HAVE_TARGET_32_BIG
|
|
// Virtual functions which may be overridden by the child class.
|
|
virtual Object*
|
|
do_make_elf_object(const std::string&, Input_file*, off_t,
|
|
const elfcpp::Ehdr<32, true>&);
|
|
#endif
|
|
|
|
#ifdef HAVE_TARGET_64_LITTLE
|
|
// Virtual functions which may be overridden by the child class.
|
|
virtual Object*
|
|
do_make_elf_object(const std::string&, Input_file*, off_t,
|
|
const elfcpp::Ehdr<64, false>& ehdr);
|
|
#endif
|
|
|
|
#ifdef HAVE_TARGET_64_BIG
|
|
// Virtual functions which may be overridden by the child class.
|
|
virtual Object*
|
|
do_make_elf_object(const std::string& name, Input_file* input_file,
|
|
off_t offset, const elfcpp::Ehdr<64, true>& ehdr);
|
|
#endif
|
|
|
|
// Virtual functions which may be overridden by the child class.
|
|
virtual Output_section*
|
|
do_make_output_section(const char* name, elfcpp::Elf_Word type,
|
|
elfcpp::Elf_Xword flags);
|
|
|
|
// Virtual function which may be overridden by the child class.
|
|
virtual bool
|
|
do_may_relax() const
|
|
{ return parameters->options().relax(); }
|
|
|
|
// Virtual function which may be overridden by the child class.
|
|
virtual bool
|
|
do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*)
|
|
{ return false; }
|
|
|
|
// A function for targets to call. Return whether BYTES/LEN matches
|
|
// VIEW/VIEW_SIZE at OFFSET.
|
|
bool
|
|
match_view(const unsigned char* view, section_size_type view_size,
|
|
section_offset_type offset, const char* bytes, size_t len) const;
|
|
|
|
// Set the contents of a VIEW/VIEW_SIZE to nops starting at OFFSET
|
|
// for LEN bytes.
|
|
void
|
|
set_view_to_nop(unsigned char* view, section_size_type view_size,
|
|
section_offset_type offset, size_t len) const;
|
|
|
|
// This must be overridden by the child class if it has target-specific
|
|
// attributes subsection in the attribute section.
|
|
virtual int
|
|
do_attribute_arg_type(int) const
|
|
{ gold_unreachable(); }
|
|
|
|
// This may be overridden by the child class.
|
|
virtual int
|
|
do_attributes_order(int num) const
|
|
{ return num; }
|
|
|
|
// This may be overridden by the child class.
|
|
virtual void
|
|
do_select_as_default_target()
|
|
{ }
|
|
|
|
// This may be overridden by the child class.
|
|
virtual void
|
|
do_define_standard_symbols(Symbol_table*, Layout*)
|
|
{ }
|
|
|
|
// This may be overridden by the child class.
|
|
virtual const char*
|
|
do_output_section_name(const Relobj*, const char*, size_t*) const
|
|
{ return NULL; }
|
|
|
|
// This may be overridden by the child class.
|
|
virtual void
|
|
do_gc_mark_symbol(Symbol_table*, Symbol*) const
|
|
{ }
|
|
|
|
private:
|
|
// The implementations of the four do_make_elf_object virtual functions are
|
|
// almost identical except for their sizes and endianness. We use a template.
|
|
// for their implementations.
|
|
template<int size, bool big_endian>
|
|
inline Object*
|
|
do_make_elf_object_implementation(const std::string&, Input_file*, off_t,
|
|
const elfcpp::Ehdr<size, big_endian>&);
|
|
|
|
Target(const Target&);
|
|
Target& operator=(const Target&);
|
|
|
|
// The target information.
|
|
const Target_info* pti_;
|
|
// Processor-specific flags.
|
|
elfcpp::Elf_Word processor_specific_flags_;
|
|
// Whether the processor-specific flags are set at least once.
|
|
bool are_processor_specific_flags_set_;
|
|
// If not ELFOSABI_NONE, the value to put in the EI_OSABI field of
|
|
// the ELF header. This is handled at this level because it is
|
|
// OS-specific rather than processor-specific.
|
|
elfcpp::ELFOSABI osabi_;
|
|
};
|
|
|
|
// The abstract class for a specific size and endianness of target.
|
|
// Each actual target implementation class should derive from an
|
|
// instantiation of Sized_target.
|
|
|
|
template<int size, bool big_endian>
|
|
class Sized_target : public Target
|
|
{
|
|
public:
|
|
// Make a new symbol table entry for the target. This should be
|
|
// overridden by a target which needs additional information in the
|
|
// symbol table. This will only be called if has_make_symbol()
|
|
// returns true.
|
|
virtual Sized_symbol<size>*
|
|
make_symbol() const
|
|
{ gold_unreachable(); }
|
|
|
|
// Resolve a symbol for the target. This should be overridden by a
|
|
// target which needs to take special action. TO is the
|
|
// pre-existing symbol. SYM is the new symbol, seen in OBJECT.
|
|
// VERSION is the version of SYM. This will only be called if
|
|
// has_resolve() returns true.
|
|
virtual void
|
|
resolve(Symbol*, const elfcpp::Sym<size, big_endian>&, Object*,
|
|
const char*)
|
|
{ gold_unreachable(); }
|
|
|
|
// Process the relocs for a section, and record information of the
|
|
// mapping from source to destination sections. This mapping is later
|
|
// used to determine unreferenced garbage sections. This procedure is
|
|
// only called during garbage collection.
|
|
virtual void
|
|
gc_process_relocs(Symbol_table* symtab,
|
|
Layout* layout,
|
|
Sized_relobj_file<size, big_endian>* object,
|
|
unsigned int data_shndx,
|
|
unsigned int sh_type,
|
|
const unsigned char* prelocs,
|
|
size_t reloc_count,
|
|
Output_section* output_section,
|
|
bool needs_special_offset_handling,
|
|
size_t local_symbol_count,
|
|
const unsigned char* plocal_symbols) = 0;
|
|
|
|
// Scan the relocs for a section, and record any information
|
|
// required for the symbol. SYMTAB is the symbol table. OBJECT is
|
|
// the object in which the section appears. DATA_SHNDX is the
|
|
// section index that these relocs apply to. SH_TYPE is the type of
|
|
// the relocation section, SHT_REL or SHT_RELA. PRELOCS points to
|
|
// the relocation data. RELOC_COUNT is the number of relocs.
|
|
// LOCAL_SYMBOL_COUNT is the number of local symbols.
|
|
// OUTPUT_SECTION is the output section.
|
|
// NEEDS_SPECIAL_OFFSET_HANDLING is true if offsets to the output
|
|
// sections are not mapped as usual. PLOCAL_SYMBOLS points to the
|
|
// local symbol data from OBJECT. GLOBAL_SYMBOLS is the array of
|
|
// pointers to the global symbol table from OBJECT.
|
|
virtual void
|
|
scan_relocs(Symbol_table* symtab,
|
|
Layout* layout,
|
|
Sized_relobj_file<size, big_endian>* object,
|
|
unsigned int data_shndx,
|
|
unsigned int sh_type,
|
|
const unsigned char* prelocs,
|
|
size_t reloc_count,
|
|
Output_section* output_section,
|
|
bool needs_special_offset_handling,
|
|
size_t local_symbol_count,
|
|
const unsigned char* plocal_symbols) = 0;
|
|
|
|
// Relocate section data. SH_TYPE is the type of the relocation
|
|
// section, SHT_REL or SHT_RELA. PRELOCS points to the relocation
|
|
// information. RELOC_COUNT is the number of relocs.
|
|
// OUTPUT_SECTION is the output section.
|
|
// NEEDS_SPECIAL_OFFSET_HANDLING is true if offsets must be mapped
|
|
// to correspond to the output section. VIEW is a view into the
|
|
// output file holding the section contents, VIEW_ADDRESS is the
|
|
// virtual address of the view, and VIEW_SIZE is the size of the
|
|
// view. If NEEDS_SPECIAL_OFFSET_HANDLING is true, the VIEW_xx
|
|
// parameters refer to the complete output section data, not just
|
|
// the input section data.
|
|
virtual void
|
|
relocate_section(const Relocate_info<size, big_endian>*,
|
|
unsigned int sh_type,
|
|
const unsigned char* prelocs,
|
|
size_t reloc_count,
|
|
Output_section* output_section,
|
|
bool needs_special_offset_handling,
|
|
unsigned char* view,
|
|
typename elfcpp::Elf_types<size>::Elf_Addr view_address,
|
|
section_size_type view_size,
|
|
const Reloc_symbol_changes*) = 0;
|
|
|
|
// Scan the relocs during a relocatable link. The parameters are
|
|
// like scan_relocs, with an additional Relocatable_relocs
|
|
// parameter, used to record the disposition of the relocs.
|
|
virtual void
|
|
scan_relocatable_relocs(Symbol_table* symtab,
|
|
Layout* layout,
|
|
Sized_relobj_file<size, big_endian>* object,
|
|
unsigned int data_shndx,
|
|
unsigned int sh_type,
|
|
const unsigned char* prelocs,
|
|
size_t reloc_count,
|
|
Output_section* output_section,
|
|
bool needs_special_offset_handling,
|
|
size_t local_symbol_count,
|
|
const unsigned char* plocal_symbols,
|
|
Relocatable_relocs*) = 0;
|
|
|
|
// Emit relocations for a section during a relocatable link, and for
|
|
// --emit-relocs. The parameters are like relocate_section, with
|
|
// additional parameters for the view of the output reloc section.
|
|
virtual void
|
|
relocate_relocs(const Relocate_info<size, big_endian>*,
|
|
unsigned int sh_type,
|
|
const unsigned char* prelocs,
|
|
size_t reloc_count,
|
|
Output_section* output_section,
|
|
typename elfcpp::Elf_types<size>::Elf_Off
|
|
offset_in_output_section,
|
|
const Relocatable_relocs*,
|
|
unsigned char* view,
|
|
typename elfcpp::Elf_types<size>::Elf_Addr view_address,
|
|
section_size_type view_size,
|
|
unsigned char* reloc_view,
|
|
section_size_type reloc_view_size) = 0;
|
|
|
|
// Perform target-specific processing in a relocatable link. This is
|
|
// only used if we use the relocation strategy RELOC_SPECIAL.
|
|
// RELINFO points to a Relocation_info structure. SH_TYPE is the relocation
|
|
// section type. PRELOC_IN points to the original relocation. RELNUM is
|
|
// the index number of the relocation in the relocation section.
|
|
// OUTPUT_SECTION is the output section to which the relocation is applied.
|
|
// OFFSET_IN_OUTPUT_SECTION is the offset of the relocation input section
|
|
// within the output section. VIEW points to the output view of the
|
|
// output section. VIEW_ADDRESS is output address of the view. VIEW_SIZE
|
|
// is the size of the output view and PRELOC_OUT points to the new
|
|
// relocation in the output object.
|
|
//
|
|
// A target only needs to override this if the generic code in
|
|
// target-reloc.h cannot handle some relocation types.
|
|
|
|
virtual void
|
|
relocate_special_relocatable(const Relocate_info<size, big_endian>*
|
|
/*relinfo */,
|
|
unsigned int /* sh_type */,
|
|
const unsigned char* /* preloc_in */,
|
|
size_t /* relnum */,
|
|
Output_section* /* output_section */,
|
|
typename elfcpp::Elf_types<size>::Elf_Off
|
|
/* offset_in_output_section */,
|
|
unsigned char* /* view */,
|
|
typename elfcpp::Elf_types<size>::Elf_Addr
|
|
/* view_address */,
|
|
section_size_type /* view_size */,
|
|
unsigned char* /* preloc_out*/)
|
|
{ gold_unreachable(); }
|
|
|
|
// Return the number of entries in the GOT. This is only used for
|
|
// laying out the incremental link info sections. A target needs
|
|
// to implement this to support incremental linking.
|
|
|
|
virtual unsigned int
|
|
got_entry_count() const
|
|
{ gold_unreachable(); }
|
|
|
|
// Return the number of entries in the PLT. This is only used for
|
|
// laying out the incremental link info sections. A target needs
|
|
// to implement this to support incremental linking.
|
|
|
|
virtual unsigned int
|
|
plt_entry_count() const
|
|
{ gold_unreachable(); }
|
|
|
|
// Return the offset of the first non-reserved PLT entry. This is
|
|
// only used for laying out the incremental link info sections.
|
|
// A target needs to implement this to support incremental linking.
|
|
|
|
virtual unsigned int
|
|
first_plt_entry_offset() const
|
|
{ gold_unreachable(); }
|
|
|
|
// Return the size of each PLT entry. This is only used for
|
|
// laying out the incremental link info sections. A target needs
|
|
// to implement this to support incremental linking.
|
|
|
|
virtual unsigned int
|
|
plt_entry_size() const
|
|
{ gold_unreachable(); }
|
|
|
|
// Create the GOT and PLT sections for an incremental update.
|
|
// A target needs to implement this to support incremental linking.
|
|
|
|
virtual Output_data_got_base*
|
|
init_got_plt_for_update(Symbol_table*,
|
|
Layout*,
|
|
unsigned int /* got_count */,
|
|
unsigned int /* plt_count */)
|
|
{ gold_unreachable(); }
|
|
|
|
// Reserve a GOT entry for a local symbol, and regenerate any
|
|
// necessary dynamic relocations.
|
|
virtual void
|
|
reserve_local_got_entry(unsigned int /* got_index */,
|
|
Sized_relobj<size, big_endian>* /* obj */,
|
|
unsigned int /* r_sym */,
|
|
unsigned int /* got_type */)
|
|
{ gold_unreachable(); }
|
|
|
|
// Reserve a GOT entry for a global symbol, and regenerate any
|
|
// necessary dynamic relocations.
|
|
virtual void
|
|
reserve_global_got_entry(unsigned int /* got_index */, Symbol* /* gsym */,
|
|
unsigned int /* got_type */)
|
|
{ gold_unreachable(); }
|
|
|
|
// Register an existing PLT entry for a global symbol.
|
|
// A target needs to implement this to support incremental linking.
|
|
|
|
virtual void
|
|
register_global_plt_entry(Symbol_table*, Layout*,
|
|
unsigned int /* plt_index */,
|
|
Symbol*)
|
|
{ gold_unreachable(); }
|
|
|
|
// Force a COPY relocation for a given symbol.
|
|
// A target needs to implement this to support incremental linking.
|
|
|
|
virtual void
|
|
emit_copy_reloc(Symbol_table*, Symbol*, Output_section*, off_t)
|
|
{ gold_unreachable(); }
|
|
|
|
// Apply an incremental relocation.
|
|
|
|
virtual void
|
|
apply_relocation(const Relocate_info<size, big_endian>* /* relinfo */,
|
|
typename elfcpp::Elf_types<size>::Elf_Addr /* r_offset */,
|
|
unsigned int /* r_type */,
|
|
typename elfcpp::Elf_types<size>::Elf_Swxword /* r_addend */,
|
|
const Symbol* /* gsym */,
|
|
unsigned char* /* view */,
|
|
typename elfcpp::Elf_types<size>::Elf_Addr /* address */,
|
|
section_size_type /* view_size */)
|
|
{ gold_unreachable(); }
|
|
|
|
// Handle target specific gc actions when adding a gc reference from
|
|
// SRC_OBJ, SRC_SHNDX to a location specified by DST_OBJ, DST_SHNDX
|
|
// and DST_OFF.
|
|
void
|
|
gc_add_reference(Symbol_table* symtab,
|
|
Object* src_obj,
|
|
unsigned int src_shndx,
|
|
Object* dst_obj,
|
|
unsigned int dst_shndx,
|
|
typename elfcpp::Elf_types<size>::Elf_Addr dst_off) const
|
|
{
|
|
this->do_gc_add_reference(symtab, src_obj, src_shndx,
|
|
dst_obj, dst_shndx, dst_off);
|
|
}
|
|
|
|
protected:
|
|
Sized_target(const Target::Target_info* pti)
|
|
: Target(pti)
|
|
{
|
|
gold_assert(pti->size == size);
|
|
gold_assert(pti->is_big_endian ? big_endian : !big_endian);
|
|
}
|
|
|
|
// Set the EI_OSABI field if requested.
|
|
virtual void
|
|
do_adjust_elf_header(unsigned char*, int) const;
|
|
|
|
// Handle target specific gc actions when adding a gc reference.
|
|
virtual void
|
|
do_gc_add_reference(Symbol_table*, Object*, unsigned int,
|
|
Object*, unsigned int,
|
|
typename elfcpp::Elf_types<size>::Elf_Addr) const
|
|
{ }
|
|
|
|
virtual void
|
|
do_function_location(Symbol_location*) const
|
|
{ }
|
|
};
|
|
|
|
} // End namespace gold.
|
|
|
|
#endif // !defined(GOLD_TARGET_H)
|