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// target-reloc.h -- target specific relocation support -*- C++ -*-
#ifndef GOLD_TARGET_RELOC_H
#define GOLD_TARGET_RELOC_H
#include "elfcpp.h"
#include "object.h"
#include "symtab.h"
namespace gold
{
// Pick the ELF relocation accessor class and the size based on
// SH_TYPE, which is either SHT_REL or SHT_RELA.
template<int sh_type, int size, bool big_endian>
struct Reloc_types;
template<int size, bool big_endian>
struct Reloc_types<elfcpp::SHT_REL, size, big_endian>
{
typedef typename elfcpp::Rel<size, big_endian> Reloc;
static const int reloc_size = elfcpp::Elf_sizes<size>::rel_size;
};
template<int size, bool big_endian>
struct Reloc_types<elfcpp::SHT_RELA, size, big_endian>
{
typedef typename elfcpp::Rela<size, big_endian> Reloc;
static const int reloc_size = elfcpp::Elf_sizes<size>::rela_size;
};
// This function implements the generic part of reloc scanning. This
// is an inline function which takes a class whose operator()
// implements the machine specific part of scanning. We do it this
// way to avoidmaking a function call for each relocation, and to
// avoid repeating the generic code for each target.
template<int size, bool big_endian, int sh_type, typename Scan>
inline void
scan_relocs(
const General_options& options,
Symbol_table* symtab,
Sized_object<size, big_endian>* object,
const unsigned char* prelocs,
size_t reloc_count,
size_t local_count,
const unsigned char* plocal_syms,
Symbol** global_syms)
{
typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
Scan scan;
for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
{
Reltype reloc(prelocs);
typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
unsigned int r_type = elfcpp::elf_r_type<size>(r_info);
if (r_sym < local_count)
{
assert(plocal_syms != NULL);
typename elfcpp::Sym<size, big_endian> lsym(plocal_syms
+ r_sym * sym_size);
const unsigned int shndx = lsym.get_st_shndx();
if (shndx < elfcpp::SHN_LORESERVE
&& !object->is_section_included(lsym.get_st_shndx()))
{
// RELOC is a relocation against a local symbol in a
// section we are discarding. We can ignore this
// relocation. It will eventually become a reloc
// against the value zero.
//
// FIXME: We should issue a warning if this is an
// allocated section; is this the best place to do it?
//
// FIXME: The old GNU linker would in some cases look
// for the linkonce section which caused this section to
// be discarded, and, if the other section was the same
// size, change the reloc to refer to the other section.
// That seems risky and weird to me, and I don't know of
// any case where it is actually required.
continue;
}
scan.local(options, object, reloc, r_type, lsym);
}
else
{
Symbol* gsym = global_syms[r_sym - local_count];
assert(gsym != NULL);
if (gsym->is_forwarder())
gsym = symtab->resolve_forwards(gsym);
scan.global(options, object, reloc, r_type, gsym);
}
}
}
// This function implements the generic part of relocation processing.
// This is an inline function which take a class whose operator()
// implements the machine specific part of relocation. We do it this
// way to avoid making a function call for each relocation, and to
// avoid repeating the generic relocation handling code for each
// target.
// SIZE is the ELF size: 32 or 64. BIG_ENDIAN is the endianness of
// the data. SH_TYPE is the section type: SHT_REL or SHT_RELA.
// RELOCATE implements operator() to do a relocation.
// PRELOCS points to the relocation data. RELOC_COUNT is the number
// of relocs. VIEW is the section data, VIEW_ADDRESS is its memory
// address, and VIEW_SIZE is the size.
template<int size, bool big_endian, int sh_type, typename Relocate>
inline void
relocate_section(
const Relocate_info<size, big_endian>* relinfo,
const unsigned char* prelocs,
size_t reloc_count,
unsigned char* view,
typename elfcpp::Elf_types<size>::Elf_Addr view_address,
off_t view_size)
{
typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
Relocate relocate;
unsigned int local_count = relinfo->local_symbol_count;
typename elfcpp::Elf_types<size>::Elf_Addr *local_values = relinfo->values;
Symbol** global_syms = relinfo->symbols;
for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
{
Reltype reloc(prelocs);
off_t offset = reloc.get_r_offset();
if (offset < 0 || offset >= view_size)
{
fprintf(stderr, _("%s: %s: reloc has bad offset %zu\n"),
program_name, relinfo->location(i, offset).c_str(),
static_cast<size_t>(offset));
gold_exit(false);
}
typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
unsigned int r_type = elfcpp::elf_r_type<size>(r_info);
Sized_symbol<size>* sym;
typename elfcpp::Elf_types<size>::Elf_Addr value;
if (r_sym < local_count)
{
sym = NULL;
value = local_values[r_sym];
}
else
{
Symbol* gsym = global_syms[r_sym - local_count];
assert(gsym != NULL);
if (gsym->is_forwarder())
gsym = relinfo->symtab->resolve_forwards(gsym);
sym = static_cast<Sized_symbol<size>*>(gsym);
value = sym->value();
if (sym->shnum() == elfcpp::SHN_UNDEF
&& sym->binding() != elfcpp::STB_WEAK)
{
fprintf(stderr, _("%s: %s: undefined reference to '%s'\n"),
program_name, relinfo->location(i, offset).c_str(),
sym->name());
// gold_exit(false);
}
}
relocate.relocate(relinfo, i, reloc, r_type, sym, value, view + offset,
view_address + offset, view_size);
}
}
} // End namespace gold.
#endif // !defined(GOLD_TARGET_RELOC_H)
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