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old-cross-binutils/gold/reloc.h
Ian Lance Taylor bef2b43452 * reloc.h (Bits): New class with static functions, copied from 
namespace utils in arm.cc.
	* arm.cc (namespace utils): Remove.  Rewrite all uses to use Bits
	instead.
2012-01-28 01:47:01 +00:00

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// reloc.h -- relocate input files for gold -*- C++ -*-
// Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012
// 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.
#ifndef GOLD_RELOC_H
#define GOLD_RELOC_H
#include <vector>
#ifdef HAVE_BYTESWAP_H
#include <byteswap.h>
#endif
#include "elfcpp.h"
#include "workqueue.h"
namespace gold
{
class General_options;
class Object;
class Relobj;
class Read_relocs_data;
class Symbol;
class Layout;
class Output_data;
class Output_section;
template<int size>
class Sized_symbol;
template<int size, bool big_endian>
class Sized_relobj_file;
template<int size>
class Symbol_value;
template<int sh_type, bool dynamic, int size, bool big_endian>
class Output_data_reloc;
// A class to read the relocations for an object file, and then queue
// up a task to see if they require any GOT/PLT/COPY relocations in
// the symbol table.
class Read_relocs : public Task
{
public:
// THIS_BLOCKER and NEXT_BLOCKER are passed along to a Scan_relocs
// or Gc_process_relocs task, so that they run in a deterministic
// order.
Read_relocs(Symbol_table* symtab, Layout* layout, Relobj* object,
Task_token* this_blocker, Task_token* next_blocker)
: symtab_(symtab), layout_(layout), object_(object),
this_blocker_(this_blocker), next_blocker_(next_blocker)
{ }
// The standard Task methods.
Task_token*
is_runnable();
void
locks(Task_locker*);
void
run(Workqueue*);
std::string
get_name() const;
private:
Symbol_table* symtab_;
Layout* layout_;
Relobj* object_;
Task_token* this_blocker_;
Task_token* next_blocker_;
};
// Process the relocs to figure out which sections are garbage.
// Very similar to scan relocs.
class Gc_process_relocs : public Task
{
public:
// THIS_BLOCKER prevents this task from running until the previous
// one is finished. NEXT_BLOCKER prevents the next task from
// running.
Gc_process_relocs(Symbol_table* symtab, Layout* layout, Relobj* object,
Read_relocs_data* rd, Task_token* this_blocker,
Task_token* next_blocker)
: symtab_(symtab), layout_(layout), object_(object), rd_(rd),
this_blocker_(this_blocker), next_blocker_(next_blocker)
{ }
~Gc_process_relocs();
// The standard Task methods.
Task_token*
is_runnable();
void
locks(Task_locker*);
void
run(Workqueue*);
std::string
get_name() const;
private:
Symbol_table* symtab_;
Layout* layout_;
Relobj* object_;
Read_relocs_data* rd_;
Task_token* this_blocker_;
Task_token* next_blocker_;
};
// Scan the relocations for an object to see if they require any
// GOT/PLT/COPY relocations.
class Scan_relocs : public Task
{
public:
// THIS_BLOCKER prevents this task from running until the previous
// one is finished. NEXT_BLOCKER prevents the next task from
// running.
Scan_relocs(Symbol_table* symtab, Layout* layout, Relobj* object,
Read_relocs_data* rd, Task_token* this_blocker,
Task_token* next_blocker)
: symtab_(symtab), layout_(layout), object_(object), rd_(rd),
this_blocker_(this_blocker), next_blocker_(next_blocker)
{ }
~Scan_relocs();
// The standard Task methods.
Task_token*
is_runnable();
void
locks(Task_locker*);
void
run(Workqueue*);
std::string
get_name() const;
private:
Symbol_table* symtab_;
Layout* layout_;
Relobj* object_;
Read_relocs_data* rd_;
Task_token* this_blocker_;
Task_token* next_blocker_;
};
// A class to perform all the relocations for an object file.
class Relocate_task : public Task
{
public:
Relocate_task(const Symbol_table* symtab, const Layout* layout,
Relobj* object, Output_file* of,
Task_token* input_sections_blocker,
Task_token* output_sections_blocker, Task_token* final_blocker)
: symtab_(symtab), layout_(layout), object_(object), of_(of),
input_sections_blocker_(input_sections_blocker),
output_sections_blocker_(output_sections_blocker),
final_blocker_(final_blocker)
{ }
// The standard Task methods.
Task_token*
is_runnable();
void
locks(Task_locker*);
void
run(Workqueue*);
std::string
get_name() const;
private:
const Symbol_table* symtab_;
const Layout* layout_;
Relobj* object_;
Output_file* of_;
Task_token* input_sections_blocker_;
Task_token* output_sections_blocker_;
Task_token* final_blocker_;
};
// During a relocatable link, this class records how relocations
// should be handled for a single input reloc section. An instance of
// this class is created while scanning relocs, and it is used while
// processing relocs.
class Relocatable_relocs
{
public:
// We use a vector of unsigned char to indicate how the input relocs
// should be handled. Each element is one of the following values.
// We create this vector when we initially scan the relocations.
enum Reloc_strategy
{
// Copy the input reloc. Don't modify it other than updating the
// r_offset field and the r_sym part of the r_info field.
RELOC_COPY,
// Copy the input reloc which is against an STT_SECTION symbol.
// Update the r_offset and r_sym part of the r_info field. Adjust
// the addend by subtracting the value of the old local symbol and
// adding the value of the new local symbol. The addend is in the
// SHT_RELA reloc and the contents of the data section do not need
// to be changed.
RELOC_ADJUST_FOR_SECTION_RELA,
// Like RELOC_ADJUST_FOR_SECTION_RELA but the addend should not be
// adjusted.
RELOC_ADJUST_FOR_SECTION_0,
// Like RELOC_ADJUST_FOR_SECTION_RELA but the contents of the
// section need to be changed. The number indicates the number of
// bytes in the addend in the section contents.
RELOC_ADJUST_FOR_SECTION_1,
RELOC_ADJUST_FOR_SECTION_2,
RELOC_ADJUST_FOR_SECTION_4,
RELOC_ADJUST_FOR_SECTION_8,
// Like RELOC_ADJUST_FOR_SECTION_4 but for unaligned relocs.
RELOC_ADJUST_FOR_SECTION_4_UNALIGNED,
// Discard the input reloc--process it completely when relocating
// the data section contents.
RELOC_DISCARD,
// An input reloc which is not discarded, but which requires
// target specific processing in order to update it.
RELOC_SPECIAL
};
Relocatable_relocs()
: reloc_strategies_(), output_reloc_count_(0), posd_(NULL)
{ }
// Record the number of relocs.
void
set_reloc_count(size_t reloc_count)
{ this->reloc_strategies_.reserve(reloc_count); }
// Record what to do for the next reloc.
void
set_next_reloc_strategy(Reloc_strategy strategy)
{
this->reloc_strategies_.push_back(static_cast<unsigned char>(strategy));
if (strategy != RELOC_DISCARD)
++this->output_reloc_count_;
}
// Record the Output_data associated with this reloc section.
void
set_output_data(Output_data* posd)
{
gold_assert(this->posd_ == NULL);
this->posd_ = posd;
}
// Return the Output_data associated with this reloc section.
Output_data*
output_data() const
{ return this->posd_; }
// Return what to do for reloc I.
Reloc_strategy
strategy(unsigned int i) const
{
gold_assert(i < this->reloc_strategies_.size());
return static_cast<Reloc_strategy>(this->reloc_strategies_[i]);
}
// Return the number of relocations to create in the output file.
size_t
output_reloc_count() const
{ return this->output_reloc_count_; }
private:
typedef std::vector<unsigned char> Reloc_strategies;
// The strategies for the input reloc. There is one entry in this
// vector for each relocation in the input section.
Reloc_strategies reloc_strategies_;
// The number of relocations to be created in the output file.
size_t output_reloc_count_;
// The output data structure associated with this relocation.
Output_data* posd_;
};
// Standard relocation routines which are used on many targets. Here
// SIZE and BIG_ENDIAN refer to the target, not the relocation type.
template<int size, bool big_endian>
class Relocate_functions
{
private:
// Do a simple relocation with the addend in the section contents.
// VALSIZE is the size of the value.
template<int valsize>
static inline void
rel(unsigned char* view,
typename elfcpp::Swap<valsize, big_endian>::Valtype value)
{
typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
Valtype* wv = reinterpret_cast<Valtype*>(view);
Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv);
elfcpp::Swap<valsize, big_endian>::writeval(wv, x + value);
}
// Like the above but for relocs at unaligned addresses.
template<int valsize>
static inline void
rel_unaligned(unsigned char* view,
typename elfcpp::Swap<valsize, big_endian>::Valtype value)
{
typedef typename elfcpp::Swap_unaligned<valsize, big_endian>::Valtype
Valtype;
Valtype x = elfcpp::Swap_unaligned<valsize, big_endian>::readval(view);
elfcpp::Swap_unaligned<valsize, big_endian>::writeval(view, x + value);
}
// Do a simple relocation using a Symbol_value with the addend in
// the section contents. VALSIZE is the size of the value to
// relocate.
template<int valsize>
static inline void
rel(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval)
{
typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
Valtype* wv = reinterpret_cast<Valtype*>(view);
Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv);
x = psymval->value(object, x);
elfcpp::Swap<valsize, big_endian>::writeval(wv, x);
}
// Like the above but for relocs at unaligned addresses.
template<int valsize>
static inline void
rel_unaligned(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval)
{
typedef typename elfcpp::Swap_unaligned<valsize, big_endian>::Valtype
Valtype;
Valtype x = elfcpp::Swap_unaligned<valsize, big_endian>::readval(view);
x = psymval->value(object, x);
elfcpp::Swap_unaligned<valsize, big_endian>::writeval(view, x);
}
// Do a simple relocation with the addend in the relocation.
// VALSIZE is the size of the value.
template<int valsize>
static inline void
rela(unsigned char* view,
typename elfcpp::Swap<valsize, big_endian>::Valtype value,
typename elfcpp::Swap<valsize, big_endian>::Valtype addend)
{
typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
Valtype* wv = reinterpret_cast<Valtype*>(view);
elfcpp::Swap<valsize, big_endian>::writeval(wv, value + addend);
}
// Do a simple relocation using a symbol value with the addend in
// the relocation. VALSIZE is the size of the value.
template<int valsize>
static inline void
rela(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
typename elfcpp::Swap<valsize, big_endian>::Valtype addend)
{
typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
Valtype* wv = reinterpret_cast<Valtype*>(view);
Valtype x = psymval->value(object, addend);
elfcpp::Swap<valsize, big_endian>::writeval(wv, x);
}
// Do a simple PC relative relocation with the addend in the section
// contents. VALSIZE is the size of the value.
template<int valsize>
static inline void
pcrel(unsigned char* view,
typename elfcpp::Swap<valsize, big_endian>::Valtype value,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{
typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
Valtype* wv = reinterpret_cast<Valtype*>(view);
Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv);
elfcpp::Swap<valsize, big_endian>::writeval(wv, x + value - address);
}
// Like the above but for relocs at unaligned addresses.
template<int valsize>
static inline void
pcrel_unaligned(unsigned char* view,
typename elfcpp::Swap<valsize, big_endian>::Valtype value,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{
typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
Valtype x = elfcpp::Swap_unaligned<valsize, big_endian>::readval(view);
elfcpp::Swap_unaligned<valsize, big_endian>::writeval(view,
x + value - address);
}
// Do a simple PC relative relocation with a Symbol_value with the
// addend in the section contents. VALSIZE is the size of the
// value.
template<int valsize>
static inline void
pcrel(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{
typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
Valtype* wv = reinterpret_cast<Valtype*>(view);
Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv);
x = psymval->value(object, x);
elfcpp::Swap<valsize, big_endian>::writeval(wv, x - address);
}
// Do a simple PC relative relocation with the addend in the
// relocation. VALSIZE is the size of the value.
template<int valsize>
static inline void
pcrela(unsigned char* view,
typename elfcpp::Swap<valsize, big_endian>::Valtype value,
typename elfcpp::Swap<valsize, big_endian>::Valtype addend,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{
typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
Valtype* wv = reinterpret_cast<Valtype*>(view);
elfcpp::Swap<valsize, big_endian>::writeval(wv, value + addend - address);
}
// Do a simple PC relative relocation with a Symbol_value with the
// addend in the relocation. VALSIZE is the size of the value.
template<int valsize>
static inline void
pcrela(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
typename elfcpp::Swap<valsize, big_endian>::Valtype addend,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{
typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
Valtype* wv = reinterpret_cast<Valtype*>(view);
Valtype x = psymval->value(object, addend);
elfcpp::Swap<valsize, big_endian>::writeval(wv, x - address);
}
typedef Relocate_functions<size, big_endian> This;
public:
// Do a simple 8-bit REL relocation with the addend in the section
// contents.
static inline void
rel8(unsigned char* view, unsigned char value)
{ This::template rel<8>(view, value); }
static inline void
rel8(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval)
{ This::template rel<8>(view, object, psymval); }
// Do an 8-bit RELA relocation with the addend in the relocation.
static inline void
rela8(unsigned char* view, unsigned char value, unsigned char addend)
{ This::template rela<8>(view, value, addend); }
static inline void
rela8(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
unsigned char addend)
{ This::template rela<8>(view, object, psymval, addend); }
// Do a simple 8-bit PC relative relocation with the addend in the
// section contents.
static inline void
pcrel8(unsigned char* view, unsigned char value,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{ This::template pcrel<8>(view, value, address); }
static inline void
pcrel8(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{ This::template pcrel<8>(view, object, psymval, address); }
// Do a simple 8-bit PC relative RELA relocation with the addend in
// the reloc.
static inline void
pcrela8(unsigned char* view, unsigned char value, unsigned char addend,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{ This::template pcrela<8>(view, value, addend, address); }
static inline void
pcrela8(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
unsigned char addend,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{ This::template pcrela<8>(view, object, psymval, addend, address); }
// Do a simple 16-bit REL relocation with the addend in the section
// contents.
static inline void
rel16(unsigned char* view, elfcpp::Elf_Half value)
{ This::template rel<16>(view, value); }
static inline void
rel16(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval)
{ This::template rel<16>(view, object, psymval); }
// Do an 16-bit RELA relocation with the addend in the relocation.
static inline void
rela16(unsigned char* view, elfcpp::Elf_Half value, elfcpp::Elf_Half addend)
{ This::template rela<16>(view, value, addend); }
static inline void
rela16(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
elfcpp::Elf_Half addend)
{ This::template rela<16>(view, object, psymval, addend); }
// Do a simple 16-bit PC relative REL relocation with the addend in
// the section contents.
static inline void
pcrel16(unsigned char* view, elfcpp::Elf_Half value,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{ This::template pcrel<16>(view, value, address); }
static inline void
pcrel16(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{ This::template pcrel<16>(view, object, psymval, address); }
// Do a simple 16-bit PC relative RELA relocation with the addend in
// the reloc.
static inline void
pcrela16(unsigned char* view, elfcpp::Elf_Half value,
elfcpp::Elf_Half addend,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{ This::template pcrela<16>(view, value, addend, address); }
static inline void
pcrela16(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
elfcpp::Elf_Half addend,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{ This::template pcrela<16>(view, object, psymval, addend, address); }
// Do a simple 32-bit REL relocation with the addend in the section
// contents.
static inline void
rel32(unsigned char* view, elfcpp::Elf_Word value)
{ This::template rel<32>(view, value); }
// Like above but for relocs at unaligned addresses.
static inline void
rel32_unaligned(unsigned char* view, elfcpp::Elf_Word value)
{ This::template rel_unaligned<32>(view, value); }
static inline void
rel32(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval)
{ This::template rel<32>(view, object, psymval); }
// Like above but for relocs at unaligned addresses.
static inline void
rel32_unaligned(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval)
{ This::template rel_unaligned<32>(view, object, psymval); }
// Do an 32-bit RELA relocation with the addend in the relocation.
static inline void
rela32(unsigned char* view, elfcpp::Elf_Word value, elfcpp::Elf_Word addend)
{ This::template rela<32>(view, value, addend); }
static inline void
rela32(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
elfcpp::Elf_Word addend)
{ This::template rela<32>(view, object, psymval, addend); }
// Do a simple 32-bit PC relative REL relocation with the addend in
// the section contents.
static inline void
pcrel32(unsigned char* view, elfcpp::Elf_Word value,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{ This::template pcrel<32>(view, value, address); }
// Unaligned version of the above.
static inline void
pcrel32_unaligned(unsigned char* view, elfcpp::Elf_Word value,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{ This::template pcrel_unaligned<32>(view, value, address); }
static inline void
pcrel32(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{ This::template pcrel<32>(view, object, psymval, address); }
// Do a simple 32-bit PC relative RELA relocation with the addend in
// the relocation.
static inline void
pcrela32(unsigned char* view, elfcpp::Elf_Word value,
elfcpp::Elf_Word addend,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{ This::template pcrela<32>(view, value, addend, address); }
static inline void
pcrela32(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
elfcpp::Elf_Word addend,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{ This::template pcrela<32>(view, object, psymval, addend, address); }
// Do a simple 64-bit REL relocation with the addend in the section
// contents.
static inline void
rel64(unsigned char* view, elfcpp::Elf_Xword value)
{ This::template rel<64>(view, value); }
static inline void
rel64(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval)
{ This::template rel<64>(view, object, psymval); }
// Do a 64-bit RELA relocation with the addend in the relocation.
static inline void
rela64(unsigned char* view, elfcpp::Elf_Xword value,
elfcpp::Elf_Xword addend)
{ This::template rela<64>(view, value, addend); }
static inline void
rela64(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
elfcpp::Elf_Xword addend)
{ This::template rela<64>(view, object, psymval, addend); }
// Do a simple 64-bit PC relative REL relocation with the addend in
// the section contents.
static inline void
pcrel64(unsigned char* view, elfcpp::Elf_Xword value,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{ This::template pcrel<64>(view, value, address); }
static inline void
pcrel64(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{ This::template pcrel<64>(view, object, psymval, address); }
// Do a simple 64-bit PC relative RELA relocation with the addend in
// the relocation.
static inline void
pcrela64(unsigned char* view, elfcpp::Elf_Xword value,
elfcpp::Elf_Xword addend,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{ This::template pcrela<64>(view, value, addend, address); }
static inline void
pcrela64(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
elfcpp::Elf_Xword addend,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{ This::template pcrela<64>(view, object, psymval, addend, address); }
};
// Integer manipulation functions used by various targets when
// performing relocations.
template<int bits>
class Bits
{
public:
// Sign extend an n-bit unsigned integer stored in a uint32_t into
// an int32_t. BITS must be between 0 and 32.
static inline int32_t
sign_extend32(uint32_t val)
{
gold_assert(bits >= 0 && bits <= 32);
if (bits == 32)
return static_cast<int32_t>(val);
uint32_t mask = (~static_cast<uint32_t>(0)) >> (32 - bits);
val &= mask;
uint32_t top_bit = 1U << (bits - 1);
int32_t as_signed = static_cast<int32_t>(val);
if ((val & top_bit) != 0)
as_signed -= static_cast<int32_t>(top_bit * 2);
return as_signed;
}
// Return true if VAL (stored in a uint32_t) has overflowed a signed
// value with BITS bits.
static inline bool
has_overflow32(uint32_t val)
{
gold_assert(bits >= 0 && bits <= 32);
if (bits == 32)
return false;
int32_t max = (1 << (bits - 1)) - 1;
int32_t min = -(1 << (bits - 1));
int32_t as_signed = static_cast<int32_t>(val);
return as_signed > max || as_signed < min;
}
// Return true if VAL (stored in a uint32_t) has overflowed both a
// signed and an unsigned value. E.g.,
// Bits<8>::has_signed_unsigned_overflow32 would check -128 <= VAL <
// 255.
static inline bool
has_signed_unsigned_overflow32(uint32_t val)
{
gold_assert(bits >= 0 && bits <= 32);
if (bits == 32)
return false;
int32_t max = static_cast<int32_t>((1U << bits) - 1);
int32_t min = -(1 << (bits - 1));
int32_t as_signed = static_cast<int32_t>(val);
return as_signed > max || as_signed < min;
}
// Select bits from A and B using bits in MASK. For each n in
// [0..31], the n-th bit in the result is chosen from the n-th bits
// of A and B. A zero selects A and a one selects B.
static inline uint32_t
bit_select32(uint32_t a, uint32_t b, uint32_t mask)
{ return (a & ~mask) | (b & mask); }
// Sign extend an n-bit unsigned integer stored in a uint64_t into
// an int64_t. BITS must be between 0 and 64.
static inline int64_t
sign_extend(uint64_t val)
{
gold_assert(bits >= 0 && bits <= 64);
if (bits == 64)
return static_cast<int64_t>(val);
uint64_t mask = (~static_cast<uint64_t>(0)) >> (64 - bits);
val &= mask;
uint64_t top_bit = static_cast<uint64_t>(1) << (bits - 1);
int64_t as_signed = static_cast<int64_t>(val);
if ((val & top_bit) != 0)
as_signed -= static_cast<int64_t>(top_bit * 2);
return as_signed;
}
// Return true if VAL (stored in a uint64_t) has overflowed a signed
// value with BITS bits.
static inline bool
has_overflow(uint64_t val)
{
gold_assert(bits >= 0 && bits <= 64);
if (bits == 64)
return false;
int64_t max = (static_cast<int64_t>(1) << (bits - 1)) - 1;
int64_t min = -(static_cast<int64_t>(1) << (bits - 1));
int64_t as_signed = static_cast<int64_t>(val);
return as_signed > max || as_signed < min;
}
// Return true if VAL (stored in a uint64_t) has overflowed both a
// signed and an unsigned value. E.g.,
// Bits<8>::has_signed_unsigned_overflow would check -128 <= VAL <
// 255.
static inline bool
has_signed_unsigned_overflow64(uint64_t val)
{
gold_assert(bits >= 0 && bits <= 64);
if (bits == 64)
return false;
int64_t max = static_cast<int64_t>((static_cast<uint64_t>(1) << bits) - 1);
int64_t min = -(static_cast<int64_t>(1) << (bits - 1));
int64_t as_signed = static_cast<int64_t>(val);
return as_signed > max || as_signed < min;
}
// Select bits from A and B using bits in MASK. For each n in
// [0..31], the n-th bit in the result is chosen from the n-th bits
// of A and B. A zero selects A and a one selects B.
static inline uint64_t
bit_select64(uint64_t a, uint64_t b, uint64_t mask)
{ return (a & ~mask) | (b & mask); }
};
// Track relocations while reading a section. This lets you ask for
// the relocation at a certain offset, and see how relocs occur
// between points of interest.
template<int size, bool big_endian>
class Track_relocs
{
public:
Track_relocs()
: prelocs_(NULL), len_(0), pos_(0), reloc_size_(0)
{ }
// Initialize the Track_relocs object. OBJECT is the object holding
// the reloc section, RELOC_SHNDX is the section index of the reloc
// section, and RELOC_TYPE is the type of the reloc section
// (elfcpp::SHT_REL or elfcpp::SHT_RELA). This returns false if
// something went wrong.
bool
initialize(Object* object, unsigned int reloc_shndx,
unsigned int reloc_type);
// Return the offset in the data section to which the next reloc
// applies. This returns -1 if there is no next reloc.
off_t
next_offset() const;
// Return the symbol index of the next reloc. This returns -1U if
// there is no next reloc.
unsigned int
next_symndx() const;
// Return the addend of the next reloc. This returns 0 if there is
// no next reloc.
uint64_t
next_addend() const;
// Advance to OFFSET within the data section, and return the number
// of relocs which would be skipped.
int
advance(off_t offset);
private:
// The contents of the input object's reloc section.
const unsigned char* prelocs_;
// The length of the reloc section.
section_size_type len_;
// Our current position in the reloc section.
section_size_type pos_;
// The size of the relocs in the section.
int reloc_size_;
};
} // End namespace gold.
#endif // !defined(GOLD_RELOC_H)
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