// reloc.h -- relocate input files for gold -*- C++ -*-
+// Copyright 2006, 2007, 2008, 2009 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>
#include <byteswap.h>
+#include "elfcpp.h"
#include "workqueue.h"
namespace gold
{
class General_options;
+class Object;
class Relobj;
class Read_relocs_data;
-class Stringpool;
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;
+
+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 standard Task methods.
- Is_runnable_type
- is_runnable(Workqueue*);
+ Task_token*
+ is_runnable();
+
+ void
+ locks(Task_locker*);
+
+ void
+ run(Workqueue*);
+
+ std::string
+ get_name() const;
+
+ private:
+ const General_options& options_;
+ Symbol_table* symtab_;
+ Layout* layout_;
+ Relobj* object_;
+ Task_token* symtab_lock_;
+ Task_token* blocker_;
+};
+
+// Process the relocs to figure out which sections are garbage.
+// Very similar to scan relocs.
+
+class Gc_process_relocs : public Task
+{
+ public:
+ // SYMTAB_LOCK is used to lock the symbol table. BLOCKER should be
+ // unblocked when the task completes.
+ Gc_process_relocs(const General_options& options, Symbol_table* symtab,
+ Layout* layout, Relobj* object, Read_relocs_data* rd,
+ Task_token* symtab_lock, Task_token* blocker)
+ : options_(options), symtab_(symtab), layout_(layout), object_(object),
+ rd_(rd), symtab_lock_(symtab_lock), blocker_(blocker)
+ { }
+
+ // The standard Task methods.
+
+ Task_token*
+ is_runnable();
- Task_locker*
- locks(Workqueue*);
+ void
+ locks(Task_locker*);
void
run(Workqueue*);
+ std::string
+ get_name() const;
+
private:
const General_options& options_;
Symbol_table* symtab_;
Layout* layout_;
Relobj* object_;
+ Read_relocs_data* rd_;
Task_token* symtab_lock_;
Task_token* blocker_;
};
// The standard Task methods.
- Is_runnable_type
- is_runnable(Workqueue*);
+ Task_token*
+ is_runnable();
- Task_locker*
- locks(Workqueue*);
+ void
+ locks(Task_locker*);
void
run(Workqueue*);
- private:
- class Scan_relocs_locker;
+ std::string
+ get_name() const;
+ private:
const General_options& options_;
Symbol_table* symtab_;
Layout* layout_;
public:
Relocate_task(const General_options& options, const Symbol_table* symtab,
const Layout* layout, Relobj* object, Output_file* of,
- Task_token* final_blocker)
+ Task_token* input_sections_blocker,
+ Task_token* output_sections_blocker, Task_token* final_blocker)
: options_(options), symtab_(symtab), layout_(layout), object_(object),
- of_(of), final_blocker_(final_blocker)
+ of_(of), input_sections_blocker_(input_sections_blocker),
+ output_sections_blocker_(output_sections_blocker),
+ final_blocker_(final_blocker)
{ }
// The standard Task methods.
- Is_runnable_type
- is_runnable(Workqueue*);
+ Task_token*
+ is_runnable();
- Task_locker*
- locks(Workqueue*);
+ void
+ locks(Task_locker*);
void
run(Workqueue*);
- private:
- class Relocate_locker;
+ std::string
+ get_name() const;
+ private:
const General_options& options_;
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,
+ // 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.
elfcpp::Swap<valsize, big_endian>::writeval(wv, 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<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);
+ }
+
+ // 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<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>
elfcpp::Swap<valsize, big_endian>::writeval(wv, 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<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<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 object
- // file data.
+ // 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);
- }
+ { This::template rel<8>(view, value); }
+
+ static inline void
+ rel8(unsigned char* view,
+ const Sized_relobj<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<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
- // object file data.
+ // 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);
- }
+ { This::template pcrel<8>(view, value, address); }
+
+ static inline void
+ pcrel8(unsigned char* view,
+ const Sized_relobj<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 16-bit REL relocation with the addend in the object
- // file data.
+ // 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<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);
- }
+ { This::template rel<16>(view, value); }
- // Do a simple 32-bit PC relative REL relocation with the addend in
- // the object file data.
static inline void
- pcrel16(unsigned char* view, elfcpp::Elf_Word value,
+ rel16(unsigned char* view,
+ const Sized_relobj<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<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);
- }
+ { This::template pcrel<16>(view, value, address); }
+
+ static inline void
+ pcrel16(unsigned char* view,
+ const Sized_relobj<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<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);
- }
+ { This::template rel<32>(view, value); }
+
+ static inline void
+ rel32(unsigned char* view,
+ const Sized_relobj<size, big_endian>* object,
+ const Symbol_value<size>* psymval)
+ { This::template rel<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<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);
- }
+ { This::template pcrel<32>(view, value, address); }
+
+ static inline void
+ pcrel32(unsigned char* view,
+ const Sized_relobj<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<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);
- }
+ { This::template rel<64>(view, value); }
+
+ static inline void
+ rel64(unsigned char* view,
+ const Sized_relobj<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<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);
- }
+ { This::template pcrel<64>(view, value, address); }
+
+ static inline void
+ pcrel64(unsigned char* view,
+ const Sized_relobj<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); }
- // Return whether we need a COPY reloc for a reloc against GSYM,
- // which is being applied to section SHNDX in OBJECT.
- static bool
- need_copy_reloc(const General_options*, Relobj* object, unsigned int shndx,
- Symbol* gsym);
+ // 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<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); }
+};
+
+// 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;
+
+ // 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.