// reloc.h -- relocate input files for gold -*- C++ -*-
+// Copyright 2006, 2007 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_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();
- Task_locker*
- locks(Workqueue*);
+ void
+ locks(Task_locker*);
void
run(Workqueue*);
+ std::string
+ get_name() const;
+
private:
const General_options& options_;
Symbol_table* symtab_;
// 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_;
};
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 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); }
- // Do a simple 16-bit REL relocation with the addend in the object
- // file data.
+ 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); }
+
+ static inline void
+ 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); }
- // 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,
+ 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); }
+
+ 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); }
+
+ // 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); }
+};
+
+// We try to avoid COPY relocations when possible. A COPY relocation
+// may be required when an executable refers to a variable defined in
+// a shared library. COPY relocations are problematic because they
+// tie the executable to the exact size of the variable in the shared
+// library. We can avoid them if all the references to the variable
+// are in a writeable section. In that case we can simply use dynamic
+// relocations. However, when scanning relocs, we don't know when we
+// see the relocation whether we will be forced to use a COPY
+// relocation or not. So we have to save the relocation during the
+// reloc scanning, and then emit it as a dynamic relocation if
+// necessary. This class implements that. It is used by the target
+// specific code.
+
+template<int size, bool big_endian>
+class Copy_relocs
+{
+ public:
+ Copy_relocs()
+ : entries_()
+ { }
+
+ // 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,
+ Sized_symbol<size>* gsym);
+
+ // Save a Rel against SYM for possible emission later. SHNDX is the
+ // index of the section to which the reloc is being applied.
+ void
+ save(Symbol* sym, Relobj*, unsigned int shndx,
+ Output_section* output_section, const elfcpp::Rel<size, big_endian>&);
+
+ // Save a Rela against SYM for possible emission later.
+ void
+ save(Symbol* sym, Relobj*, unsigned int shndx,
+ Output_section* output_section, const elfcpp::Rela<size, big_endian>&);
+
+ // Return whether there are any relocs to emit. This also discards
+ // entries which need not be emitted.
+ bool
+ any_to_emit();
+
+ // Emit relocs for each symbol which did not get a COPY reloc (i.e.,
+ // is still defined in the dynamic object).
+ template<int sh_type>
+ void
+ emit(Output_data_reloc<sh_type, true, size, big_endian>*);
+
+ private:
+ typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
+ typedef typename elfcpp::Elf_types<size>::Elf_Addr Addend;
+
+ // This POD class holds the entries we are saving.
+ class Copy_reloc_entry
{
- This::template pcrel<64>(view, value, address);
- }
+ public:
+ Copy_reloc_entry(Symbol* sym, unsigned int reloc_type,
+ Relobj* relobj, unsigned int shndx,
+ Output_section* output_section,
+ Address address, Addend addend)
+ : sym_(sym), reloc_type_(reloc_type), relobj_(relobj),
+ shndx_(shndx), output_section_(output_section),
+ address_(address), addend_(addend)
+ { }
+
+ // Return whether we should emit this reloc. If we should not
+ // emit, we clear it.
+ bool
+ should_emit();
+
+ // Emit this reloc.
+
+ void
+ emit(Output_data_reloc<elfcpp::SHT_REL, true, size, big_endian>*);
+
+ void
+ emit(Output_data_reloc<elfcpp::SHT_RELA, true, size, big_endian>*);
+
+ private:
+ Symbol* sym_;
+ unsigned int reloc_type_;
+ Relobj* relobj_;
+ unsigned int shndx_;
+ Output_section* output_section_;
+ Address address_;
+ Addend addend_;
+ };
+
+ // A list of relocs to be saved.
+ typedef std::vector<Copy_reloc_entry> Copy_reloc_entries;
+
+ // The list of relocs we are saving.
+ Copy_reloc_entries entries_;
+};
+
+// 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.
projects / deliverable / binutils-gdb.git / blobdiff