// target-reloc.h -- target specific relocation support -*- C++ -*-
-// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
+// Copyright (C) 2006-2015 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
// template parameter Scan must be a class type which provides two
// functions: local() and global(). Those functions implement the
// machine specific part of scanning. We do it this way to
-// avoidmaking a function call for each relocation, and to avoid
+// avoid making a function call for each relocation, and to avoid
// repeating the generic code for each target.
template<int size, bool big_endian, typename Target_type, int sh_type,
Symbol_table* symtab,
Layout* layout,
Target_type* target,
- Sized_relobj<size, big_endian>* object,
+ Sized_relobj_file<size, big_endian>* object,
unsigned int data_shndx,
const unsigned char* prelocs,
size_t reloc_count,
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(shndx)
- && !symtab->is_section_folded(object, 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;
- }
+ // If RELOC is a relocation against a local symbol in a
+ // section we are discarding then we can ignore it. 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.
+ bool is_discarded = (is_ordinary
+ && shndx != elfcpp::SHN_UNDEF
+ && !object->is_section_included(shndx)
+ && !symtab->is_section_folded(object, shndx));
scan.local(symtab, layout, target, object, data_shndx,
- output_section, reloc, r_type, lsym);
+ output_section, reloc, r_type, lsym, is_discarded);
}
else
{
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)
+class Default_comdat_behavior
{
- 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;
-}
+ public:
+ // 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(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;
+ }
+};
// Give an error for a symbol with non-default visibility which is not
// defined locally.
v, sym->name());
}
+// Return true if we are should issue an error saying that SYM is an
+// undefined symbol. This is called if there is a relocation against
+// SYM.
+
+inline bool
+issue_undefined_symbol_error(const Symbol* sym)
+{
+ // We only report global symbols.
+ if (sym == NULL)
+ return false;
+
+ // We only report undefined symbols.
+ if (!sym->is_undefined() && !sym->is_placeholder())
+ return false;
+
+ // We don't report weak symbols.
+ if (sym->is_weak_undefined())
+ return false;
+
+ // We don't report symbols defined in discarded sections.
+ if (sym->is_defined_in_discarded_section())
+ return false;
+
+ // If the target defines this symbol, don't report it here.
+ if (parameters->target().is_defined_by_abi(sym))
+ return false;
+
+ // See if we've been told to ignore whether this symbol is
+ // undefined.
+ const char* const u = parameters->options().unresolved_symbols();
+ if (u != NULL)
+ {
+ if (strcmp(u, "ignore-all") == 0)
+ return false;
+ if (strcmp(u, "report-all") == 0)
+ return true;
+ if (strcmp(u, "ignore-in-object-files") == 0 && !sym->in_dyn())
+ return false;
+ if (strcmp(u, "ignore-in-shared-libs") == 0 && !sym->in_reg())
+ return false;
+ }
+
+ // If the symbol is hidden, report it.
+ if (sym->visibility() == elfcpp::STV_HIDDEN)
+ return true;
+
+ // When creating a shared library, only report unresolved symbols if
+ // -z defs was used.
+ if (parameters->options().shared() && !parameters->options().defs())
+ return false;
+
+ // Otherwise issue a warning.
+ return true;
+}
+
// 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
// specific part of a relocation.
+// The template parameter Relocate_comdat_behavior is a class type
+// which provides a single function, get(), which determines what the
+// linker should do for relocations that refer to discarded comdat
+// sections.
+
// 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.
// relocation.
template<int size, bool big_endian, typename Target_type, int sh_type,
- typename Relocate>
+ typename Relocate,
+ typename Relocate_comdat_behavior>
inline void
relocate_section(
const Relocate_info<size, big_endian>* relinfo,
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;
+ Relocate_comdat_behavior relocate_comdat_behavior;
- Sized_relobj<size, big_endian>* object = relinfo->object;
+ Sized_relobj_file<size, big_endian>* object = relinfo->object;
unsigned int local_count = object->local_symbol_count();
Comdat_behavior comdat_behavior = CB_UNDETERMINED;
// 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
+ // counterpart in the kept section. The symbol must not
// correspond to a section we are folding.
bool is_ordinary;
shndx = psymval->input_shndx(&is_ordinary);
else
symval.set_no_output_symtab_entry();
symval.set_output_value(sym->value());
+ if (gsym->type() == elfcpp::STT_TLS)
+ symval.set_is_tls_symbol();
+ else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
+ symval.set_is_ifunc_symbol();
psymval = &symval;
is_defined_in_discarded_section =
if (comdat_behavior == CB_UNDETERMINED)
{
std::string name = object->section_name(relinfo->data_shndx);
- comdat_behavior = get_comdat_behavior(name.c_str());
+ comdat_behavior = relocate_comdat_behavior.get(name.c_str());
}
if (comdat_behavior == CB_PRETEND)
{
psymval = &symval2;
}
+ // If OFFSET is out of range, still let the target decide to
+ // ignore the relocation. Pass in NULL as the VIEW argument so
+ // that it can return quickly without trashing an invalid memory
+ // address.
+ unsigned char *v = view + offset;
+ if (offset < 0 || static_cast<section_size_type>(offset) >= view_size)
+ v = NULL;
+
if (!relocate.relocate(relinfo, target, output_section, i, reloc,
- r_type, sym, psymval, view + offset,
- view_address + offset, view_size))
+ r_type, sym, psymval, v, view_address + offset,
+ view_size))
continue;
- if (offset < 0 || static_cast<section_size_type>(offset) >= view_size)
+ if (v == NULL)
{
gold_error_at_location(relinfo, i, offset,
_("reloc has bad offset %zu"),
continue;
}
- if (sym != NULL
- && sym->is_undefined()
- && sym->binding() != elfcpp::STB_WEAK
- && !is_defined_in_discarded_section
- && !target->is_defined_by_abi(sym)
- && (!parameters->options().shared() // -shared
- || parameters->options().defs())) // -z defs
+ if (issue_undefined_symbol_error(sym))
gold_undefined_symbol_at_location(sym, relinfo, i, offset);
else if (sym != NULL
&& sym->visibility() != elfcpp::STV_DEFAULT
- && (sym->is_undefined() || sym->is_from_dynobj()))
+ && (sym->is_strong_undefined() || sym->is_from_dynobj()))
visibility_error(sym);
if (sym != NULL && sym->has_warning())
}
}
+// Apply an incremental relocation.
+
+template<int size, bool big_endian, typename Target_type,
+ typename Relocate>
+void
+apply_relocation(const Relocate_info<size, big_endian>* relinfo,
+ Target_type* target,
+ typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
+ unsigned int r_type,
+ typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
+ const Symbol* gsym,
+ unsigned char* view,
+ typename elfcpp::Elf_types<size>::Elf_Addr address,
+ section_size_type view_size)
+{
+ // Construct the ELF relocation in a temporary buffer.
+ const int reloc_size = elfcpp::Elf_sizes<size>::rela_size;
+ unsigned char relbuf[reloc_size];
+ elfcpp::Rela<size, big_endian> rel(relbuf);
+ elfcpp::Rela_write<size, big_endian> orel(relbuf);
+ orel.put_r_offset(r_offset);
+ orel.put_r_info(elfcpp::elf_r_info<size>(0, r_type));
+ orel.put_r_addend(r_addend);
+
+ // Setup a Symbol_value for the global symbol.
+ const Sized_symbol<size>* sym = static_cast<const Sized_symbol<size>*>(gsym);
+ Symbol_value<size> symval;
+ gold_assert(sym->has_symtab_index() && sym->symtab_index() != -1U);
+ symval.set_output_symtab_index(sym->symtab_index());
+ symval.set_output_value(sym->value());
+ if (gsym->type() == elfcpp::STT_TLS)
+ symval.set_is_tls_symbol();
+ else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
+ symval.set_is_ifunc_symbol();
+
+ Relocate relocate;
+ relocate.relocate(relinfo, target, NULL, -1U, rel, r_type, sym, &symval,
+ view + r_offset, address + r_offset, view_size);
+}
+
// This class may be used as a typical class for the
// Scan_relocatable_reloc parameter to scan_relocatable_relocs. The
// template parameter Classify_reloc must be a class type which
scan_relocatable_relocs(
Symbol_table*,
Layout*,
- Sized_relobj<size, big_endian>* object,
+ Sized_relobj_file<size, big_endian>* object,
unsigned int data_shndx,
const unsigned char* prelocs,
size_t reloc_count,
}
}
-// Relocate relocs during a relocatable link. This is a default
-// definition which should work for most targets.
+// Relocate relocs. Called for a relocatable link, and for --emit-relocs.
+// This is a default definition which should work for most targets.
template<int size, bool big_endian, int sh_type>
void
-relocate_for_relocatable(
+relocate_relocs(
const Relocate_info<size, big_endian>* relinfo,
const unsigned char* prelocs,
size_t reloc_count,
Output_section* output_section,
- typename elfcpp::Elf_types<size>::Elf_Addr offset_in_output_section,
+ typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
const Relocatable_relocs* rr,
unsigned char* view,
typename elfcpp::Elf_types<size>::Elf_Addr view_address,
- section_size_type,
+ section_size_type view_size,
unsigned char* reloc_view,
section_size_type reloc_view_size)
{
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;
+ Sized_relobj_file<size, big_endian>* const object = relinfo->object;
const unsigned int local_count = object->local_symbol_count();
unsigned char* pwrite = reloc_view;
if (strategy == Relocatable_relocs::RELOC_DISCARD)
continue;
+ if (strategy == Relocatable_relocs::RELOC_SPECIAL)
+ {
+ // Target wants to handle this relocation.
+ Sized_target<size, big_endian>* target =
+ parameters->sized_target<size, big_endian>();
+ target->relocate_special_relocatable(relinfo, sh_type, prelocs,
+ i, output_section,
+ offset_in_output_section,
+ view, view_address,
+ view_size, pwrite);
+ pwrite += reloc_size;
+ continue;
+ }
Reltype reloc(prelocs);
Reltype_write reloc_write(pwrite);
case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_2:
case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4:
case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_8:
+ case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4_UNALIGNED:
{
// We are adjusting a section symbol. We need to find
// the symbol table index of the section symbol for
psymval);
break;
+ case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4_UNALIGNED:
+ Relocate_functions<size, big_endian>::rel32_unaligned(padd,
+ object,
+ psymval);
+ break;
+
default:
gold_unreachable();
}
projects / deliverable / binutils-gdb.git / blobdiff