// target-reloc.h -- target specific relocation support -*- C++ -*-
-// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#include "elfcpp.h"
#include "symtab.h"
+#include "object.h"
#include "reloc.h"
#include "reloc-types.h"
typename Scan>
inline void
scan_relocs(
- const General_options& options,
Symbol_table* symtab,
Layout* layout,
Target_type* target,
gold_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
+ unsigned int shndx = lsym.get_st_shndx();
+ bool is_ordinary;
+ shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
+ if (is_ordinary
&& shndx != elfcpp::SHN_UNDEF
- && !object->is_section_included(lsym.get_st_shndx()))
+ && !object->is_section_included(shndx))
{
// RELOC is a relocation against a local symbol in a
// section we are discarding. We can ignore this
continue;
}
- scan.local(options, symtab, layout, target, object, data_shndx,
+ scan.local(symtab, layout, target, object, data_shndx,
output_section, reloc, r_type, lsym);
}
else
if (gsym->is_forwarder())
gsym = symtab->resolve_forwards(gsym);
- scan.global(options, symtab, layout, target, object, data_shndx,
+ scan.global(symtab, layout, target, object, data_shndx,
output_section, reloc, r_type, gsym);
}
}
}
+// Behavior for relocations to discarded comdat sections.
+
+enum Comdat_behavior
+{
+ CB_UNDETERMINED, // Not yet determined -- need to look at section name.
+ CB_PRETEND, // Attempt to map to the corresponding kept section.
+ CB_IGNORE, // Ignore the relocation.
+ CB_WARNING // Print a warning.
+};
+
+// Decide what the linker should do for relocations that refer to discarded
+// comdat sections. This decision is based on the name of the section being
+// relocated.
+
+inline Comdat_behavior
+get_comdat_behavior(const char* name)
+{
+ if (Layout::is_debug_info_section(name))
+ return CB_PRETEND;
+ if (strcmp(name, ".eh_frame") == 0
+ || strcmp(name, ".gcc_except_table") == 0)
+ return CB_IGNORE;
+ return CB_WARNING;
+}
+
// This function implements the generic part of relocation processing.
// The template parameter Relocate must be a class type which provides
// a single function, relocate(), which implements the machine
// NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
// the output section.
+// RELOC_SYMBOL_CHANGES is used for -fsplit-stack support. If it is
+// not NULL, it is a vector indexed by relocation index. If that
+// entry is not NULL, it points to a global symbol which used as the
+// symbol for the relocation, ignoring the symbol index in the
+// relocation.
+
template<int size, bool big_endian, typename Target_type, int sh_type,
typename Relocate>
inline void
bool needs_special_offset_handling,
unsigned char* view,
typename elfcpp::Elf_types<size>::Elf_Addr view_address,
- section_size_type view_size)
+ section_size_type view_size,
+ const Reloc_symbol_changes* reloc_symbol_changes)
{
typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
Sized_relobj<size, big_endian>* object = relinfo->object;
unsigned int local_count = object->local_symbol_count();
+ Comdat_behavior comdat_behavior = CB_UNDETERMINED;
+
for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
{
Reltype reloc(prelocs);
Symbol_value<size> symval;
const Symbol_value<size> *psymval;
- if (r_sym < local_count)
+ if (r_sym < local_count
+ && (reloc_symbol_changes == NULL
+ || (*reloc_symbol_changes)[i] == NULL))
{
sym = NULL;
psymval = object->local_symbol(r_sym);
+
+ // If the local symbol belongs to a section we are discarding,
+ // and that section is a debug section, try to find the
+ // corresponding kept section and map this symbol to its
+ // counterpart in the kept section. The symbol must not
+ // correspond to a section we are folding.
+ bool is_ordinary;
+ unsigned int shndx = psymval->input_shndx(&is_ordinary);
+ if (is_ordinary
+ && shndx != elfcpp::SHN_UNDEF
+ && !object->is_section_included(shndx)
+ && !(relinfo->symtab->is_section_folded(object, shndx)))
+ {
+ if (comdat_behavior == CB_UNDETERMINED)
+ {
+ std::string name = object->section_name(relinfo->data_shndx);
+ comdat_behavior = get_comdat_behavior(name.c_str());
+ }
+ if (comdat_behavior == CB_PRETEND)
+ {
+ bool found;
+ typename elfcpp::Elf_types<size>::Elf_Addr value =
+ object->map_to_kept_section(shndx, &found);
+ if (found)
+ symval.set_output_value(value + psymval->input_value());
+ else
+ symval.set_output_value(0);
+ }
+ else
+ {
+ if (comdat_behavior == CB_WARNING)
+ gold_warning_at_location(relinfo, i, offset,
+ _("relocation refers to discarded "
+ "comdat section"));
+ symval.set_output_value(0);
+ }
+ symval.set_no_output_symtab_entry();
+ psymval = &symval;
+ }
}
else
{
- const Symbol* gsym = object->global_symbol(r_sym);
- gold_assert(gsym != NULL);
- if (gsym->is_forwarder())
- gsym = relinfo->symtab->resolve_forwards(gsym);
+ const Symbol* gsym;
+ if (reloc_symbol_changes != NULL
+ && (*reloc_symbol_changes)[i] != NULL)
+ gsym = (*reloc_symbol_changes)[i];
+ else
+ {
+ gsym = object->global_symbol(r_sym);
+ gold_assert(gsym != NULL);
+ if (gsym->is_forwarder())
+ gsym = relinfo->symtab->resolve_forwards(gsym);
+ }
sym = static_cast<const Sized_symbol<size>*>(gsym);
if (sym->has_symtab_index())
psymval = &symval;
}
- if (!relocate.relocate(relinfo, target, i, reloc, r_type, sym, psymval,
- view + offset, view_address + offset, view_size))
+ if (!relocate.relocate(relinfo, target, output_section, i, reloc,
+ r_type, sym, psymval, view + offset,
+ view_address + offset, view_size))
continue;
if (offset < 0 || static_cast<section_size_type>(offset) >= view_size)
if (sym != NULL
&& sym->is_undefined()
&& sym->binding() != elfcpp::STB_WEAK
- && !parameters->options().shared())
- gold_undefined_symbol(sym, relinfo, i, offset);
+ && !target->is_defined_by_abi(sym)
+ && (!parameters->options().shared() // -shared
+ || parameters->options().defs())) // -z defs
+ gold_undefined_symbol_at_location(sym, relinfo, i, offset);
if (sym != NULL && sym->has_warning())
relinfo->symtab->issue_warning(sym, relinfo, i, offset);
// Return the strategy to use for a local symbol which is not a
// section symbol, given the relocation type.
inline Relocatable_relocs::Reloc_strategy
- local_non_section_strategy(unsigned int, Relobj*)
- { return Relocatable_relocs::RELOC_COPY; }
+ local_non_section_strategy(unsigned int r_type, Relobj*, unsigned int r_sym)
+ {
+ // We assume that relocation type 0 is NONE. Targets which are
+ // different must override.
+ if (r_type == 0 && r_sym == 0)
+ return Relocatable_relocs::RELOC_DISCARD;
+ return Relocatable_relocs::RELOC_COPY;
+ }
// Return the strategy to use for a local symbol which is a section
// symbol, given the relocation type.
typename Scan_relocatable_reloc>
void
scan_relocatable_relocs(
- const General_options&,
Symbol_table*,
Layout*,
Sized_relobj<size, big_endian>* object,
gold_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
+ unsigned int shndx = lsym.get_st_shndx();
+ bool is_ordinary;
+ shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
+ if (is_ordinary
&& shndx != elfcpp::SHN_UNDEF
- && !object->is_section_included(lsym.get_st_shndx()))
+ && !object->is_section_included(shndx))
{
// RELOC is a relocation against a local symbol
// defined in a section we are discarding. Discard
strategy = Relocatable_relocs::RELOC_DISCARD;
}
else if (lsym.get_st_type() != elfcpp::STT_SECTION)
- strategy = scan.local_non_section_strategy(r_type, object);
+ strategy = scan.local_non_section_strategy(r_type, object,
+ r_sym);
else
{
strategy = scan.local_section_strategy(r_type, object);
if (strategy != Relocatable_relocs::RELOC_DISCARD)
- {
- section_offset_type dummy;
- Output_section* os = object->output_section(shndx,
- &dummy);
- os->set_needs_symtab_index();
- }
+ object->output_section(shndx)->set_needs_symtab_index();
}
}
}
const unsigned char* prelocs,
size_t reloc_count,
Output_section* output_section,
- off_t offset_in_output_section,
+ typename elfcpp::Elf_types<size>::Elf_Addr offset_in_output_section,
const Relocatable_relocs* rr,
unsigned char* view,
typename elfcpp::Elf_types<size>::Elf_Addr view_address,
unsigned char* reloc_view,
section_size_type reloc_view_size)
{
+ typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
typedef typename Reloc_types<sh_type, size, big_endian>::Reloc_write
Reltype_write;
const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
+ const Address invalid_address = static_cast<Address>(0) - 1;
Sized_relobj<size, big_endian>* const object = relinfo->object;
const unsigned int local_count = object->local_symbol_count();
switch (strategy)
{
case Relocatable_relocs::RELOC_COPY:
- new_symndx = object->symtab_index(r_sym);
- gold_assert(new_symndx != -1U);
+ if (r_sym == 0)
+ new_symndx = 0;
+ else
+ {
+ new_symndx = object->symtab_index(r_sym);
+ gold_assert(new_symndx != -1U);
+ }
break;
case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA:
// the output section corresponding to input section
// in which this symbol is defined.
gold_assert(r_sym < local_count);
- unsigned int shndx = object->local_symbol_input_shndx(r_sym);
- section_offset_type dummy;
- Output_section* os = object->output_section(shndx, &dummy);
+ bool is_ordinary;
+ unsigned int shndx =
+ object->local_symbol_input_shndx(r_sym, &is_ordinary);
+ gold_assert(is_ordinary);
+ Output_section* os = object->output_section(shndx);
gold_assert(os != NULL);
gold_assert(os->needs_symtab_index());
new_symndx = os->symtab_index();
// Get the new offset--the location in the output section where
// this relocation should be applied.
- off_t offset = reloc.get_r_offset();
- off_t new_offset;
- if (offset_in_output_section != -1)
+ Address offset = reloc.get_r_offset();
+ Address new_offset;
+ if (offset_in_output_section != invalid_address)
new_offset = offset + offset_in_output_section;
else
{
- new_offset = output_section->output_offset(object,
- relinfo->data_shndx,
- offset);
- gold_assert(new_offset != -1);
+ section_offset_type sot_offset =
+ convert_types<section_offset_type, Address>(offset);
+ section_offset_type new_sot_offset =
+ output_section->output_offset(object, relinfo->data_shndx,
+ sot_offset);
+ gold_assert(new_sot_offset != -1);
+ new_offset = new_sot_offset;
}
// In an object file, r_offset is an offset within the section.
// In an executable or dynamic object, generated by
// --emit-relocs, r_offset is an absolute address.
if (!parameters->options().relocatable())
- new_offset += view_address;
+ {
+ new_offset += view_address;
+ if (offset_in_output_section != invalid_address)
+ new_offset -= offset_in_output_section;
+ }
reloc_write.put_r_offset(new_offset);
reloc_write.put_r_info(elfcpp::elf_r_info<size>(new_symndx, r_type));
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