// target-reloc.h -- target specific relocation support -*- C++ -*-
-// Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013
-// Free Software Foundation, Inc.
+// Copyright (C) 2006-2021 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
// 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,
- typename Scan>
+template<int size, bool big_endian, typename Target_type,
+ typename Scan, typename Classify_reloc>
inline void
scan_relocs(
Symbol_table* symtab,
size_t local_count,
const unsigned char* plocal_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;
+ typedef typename Classify_reloc::Reltype Reltype;
+ const int reloc_size = Classify_reloc::reloc_size;
const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
Scan scan;
reloc.get_r_offset()))
continue;
- 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);
+ unsigned int r_sym = Classify_reloc::get_r_sym(&reloc);
+ unsigned int r_type = Classify_reloc::get_r_type(&reloc);
if (r_sym < local_count)
{
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.
+ CB_ERROR // Print an error.
};
class Default_comdat_behavior
if (Layout::is_debug_info_section(name))
return CB_PRETEND;
if (strcmp(name, ".eh_frame") == 0
+ || is_prefix_of (".gnu.build.attributes", name)
|| strcmp(name, ".gcc_except_table") == 0)
return CB_IGNORE;
- return CB_WARNING;
+ return CB_ERROR;
}
};
return false;
// We don't report weak symbols.
- if (sym->binding() == elfcpp::STB_WEAK)
+ if (sym->is_weak_undefined())
return false;
- // We don't report symbols defined in discarded sections.
- if (sym->is_defined_in_discarded_section())
+ // We don't report symbols defined in discarded sections,
+ // unless they're placeholder symbols that should have been
+ // provided by a plugin.
+ if (sym->is_defined_in_discarded_section() && !sym->is_placeholder())
return false;
// If the target defines this symbol, don't report it here.
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 true;
}
+template<int size, bool big_endian>
+inline void
+issue_discarded_error(
+ const Relocate_info<size, big_endian>* relinfo,
+ size_t shndx,
+ section_offset_type offset,
+ unsigned int r_sym,
+ const Symbol* gsym)
+{
+ Sized_relobj_file<size, big_endian>* object = relinfo->object;
+
+ if (gsym == NULL)
+ {
+ gold_error_at_location(
+ relinfo, shndx, offset,
+ _("relocation refers to local symbol \"%s\" [%u], "
+ "which is defined in a discarded section"),
+ object->get_symbol_name(r_sym), r_sym);
+ }
+ else
+ {
+ gold_error_at_location(
+ relinfo, shndx, offset,
+ _("relocation refers to global symbol \"%s\", "
+ "which is defined in a discarded section"),
+ gsym->demangled_name().c_str());
+ }
+
+ bool is_ordinary;
+ typename elfcpp::Elf_types<size>::Elf_Addr value;
+ unsigned int orig_shndx = object->symbol_section_and_value(r_sym, &value,
+ &is_ordinary);
+ if (orig_shndx != elfcpp::SHN_UNDEF)
+ {
+ unsigned int key_symndx = 0;
+ Relobj* kept_obj = object->find_kept_section_object(orig_shndx,
+ &key_symndx);
+ if (key_symndx != 0)
+ gold_info(_(" section group signature: \"%s\""),
+ object->get_symbol_name(key_symndx));
+ if (kept_obj != NULL)
+ gold_info(_(" prevailing definition is from %s"),
+ kept_obj->name().c_str());
+ }
+}
+
// 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
// symbol for the relocation, ignoring the symbol index in the
// relocation.
-template<int size, bool big_endian, typename Target_type, int sh_type,
+template<int size, bool big_endian, typename Target_type,
typename Relocate,
- typename Relocate_comdat_behavior>
+ typename Relocate_comdat_behavior,
+ typename Classify_reloc>
inline void
relocate_section(
const Relocate_info<size, big_endian>* relinfo,
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;
+ typedef typename Classify_reloc::Reltype Reltype;
+ const int reloc_size = Classify_reloc::reloc_size;
Relocate relocate;
Relocate_comdat_behavior relocate_comdat_behavior;
continue;
}
- 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);
+ unsigned int r_sym = Classify_reloc::get_r_sym(&reloc);
const Sized_symbol<size>* sym;
const Symbol_value<size> *psymval;
bool is_defined_in_discarded_section;
unsigned int shndx;
+ const Symbol* gsym = NULL;
if (r_sym < local_count
&& (reloc_symbol_changes == NULL
|| (*reloc_symbol_changes)[i] == NULL))
}
else
{
- const Symbol* gsym;
if (reloc_symbol_changes != NULL
&& (*reloc_symbol_changes)[i] != NULL)
gsym = (*reloc_symbol_changes)[i];
Symbol_value<size> symval2;
if (is_defined_in_discarded_section)
{
+ std::string name = object->section_name(relinfo->data_shndx);
+
if (comdat_behavior == CB_UNDETERMINED)
- {
- std::string name = object->section_name(relinfo->data_shndx);
comdat_behavior = relocate_comdat_behavior.get(name.c_str());
- }
+
if (comdat_behavior == CB_PRETEND)
{
// FIXME: This case does not work for global symbols.
// script.
bool found;
typename elfcpp::Elf_types<size>::Elf_Addr value =
- object->map_to_kept_section(shndx, &found);
+ object->map_to_kept_section(shndx, name, &found);
if (found)
symval2.set_output_value(value + psymval->input_value());
else
}
else
{
- if (comdat_behavior == CB_WARNING)
- gold_warning_at_location(relinfo, i, offset,
- _("relocation refers to discarded "
- "section"));
+ if (comdat_behavior == CB_ERROR)
+ issue_discarded_error(relinfo, i, offset, r_sym, gsym);
symval2.set_output_value(0);
}
symval2.set_no_output_symtab_entry();
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, v, view_address + offset,
- view_size))
+ if (!relocate.relocate(relinfo, Classify_reloc::sh_type, target,
+ output_section, i, prelocs, sym, psymval,
+ v, view_address + offset, view_size))
continue;
if (v == NULL)
}
if (issue_undefined_symbol_error(sym))
- {
- gold_undefined_symbol_at_location(sym, relinfo, i, offset);
- if (sym->is_cxx_vtable())
- gold_info(_("%s: the vtable symbol may be undefined because "
- "the class is missing its key function"),
- program_name);
- }
+ 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())
// 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));
symval.set_is_ifunc_symbol();
Relocate relocate;
- relocate.relocate(relinfo, target, NULL, -1U, rel, r_type, sym, &symval,
+ relocate.relocate(relinfo, elfcpp::SHT_RELA, target, NULL,
+ -1U, relbuf, sym, &symval,
view + r_offset, address + r_offset, view_size);
}
+// A class for inquiring about properties of a relocation,
+// used while scanning relocs during a relocatable link and
+// garbage collection. This class may be used as the default
+// for SHT_RELA targets, but SHT_REL targets must implement
+// a derived class that overrides get_size_for_reloc.
+// The MIPS-64 target also needs to override the methods
+// for accessing the r_sym and r_type fields of a relocation,
+// due to its non-standard use of the r_info field.
+
+template<int sh_type_, int size, bool big_endian>
+class Default_classify_reloc
+{
+ public:
+ typedef typename Reloc_types<sh_type_, size, big_endian>::Reloc
+ Reltype;
+ typedef typename Reloc_types<sh_type_, size, big_endian>::Reloc_write
+ Reltype_write;
+ static const int reloc_size =
+ Reloc_types<sh_type_, size, big_endian>::reloc_size;
+ static const int sh_type = sh_type_;
+
+ // Return the symbol referred to by the relocation.
+ static inline unsigned int
+ get_r_sym(const Reltype* reloc)
+ { return elfcpp::elf_r_sym<size>(reloc->get_r_info()); }
+
+ // Return the type of the relocation.
+ static inline unsigned int
+ get_r_type(const Reltype* reloc)
+ { return elfcpp::elf_r_type<size>(reloc->get_r_info()); }
+
+ // Return the explicit addend of the relocation (return 0 for SHT_REL).
+ static inline typename elfcpp::Elf_types<size>::Elf_Swxword
+ get_r_addend(const Reltype* reloc)
+ { return Reloc_types<sh_type_, size, big_endian>::get_reloc_addend(reloc); }
+
+ // Write the r_info field to a new reloc, using the r_info field from
+ // the original reloc, replacing the r_sym field with R_SYM.
+ static inline void
+ put_r_info(Reltype_write* new_reloc, Reltype* reloc, unsigned int r_sym)
+ {
+ unsigned int r_type = elfcpp::elf_r_type<size>(reloc->get_r_info());
+ new_reloc->put_r_info(elfcpp::elf_r_info<size>(r_sym, r_type));
+ }
+
+ // Write the r_addend field to a new reloc.
+ static inline void
+ put_r_addend(Reltype_write* to,
+ typename elfcpp::Elf_types<size>::Elf_Swxword addend)
+ { Reloc_types<sh_type_, size, big_endian>::set_reloc_addend(to, addend); }
+
+ // Return the size of the addend of the relocation (only used for SHT_REL).
+ static unsigned int
+ get_size_for_reloc(unsigned int, Relobj*)
+ {
+ gold_unreachable();
+ return 0;
+ }
+};
+
// 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
-// provides a function get_size_for_reloc which returns the number of
-// bytes to which a reloc applies. This class is intended to capture
-// the most typical target behaviour, while still permitting targets
-// to define their own independent class for Scan_relocatable_reloc.
-
-template<int sh_type, typename Classify_reloc>
+// Scan_relocatable_reloc parameter to scan_relocatable_relocs.
+// This class is intended to capture the most typical target behaviour,
+// while still permitting targets to define their own independent class
+// for Scan_relocatable_reloc.
+
+template<typename Classify_reloc>
class Default_scan_relocatable_relocs
{
public:
+ typedef typename Classify_reloc::Reltype Reltype;
+ static const int reloc_size = Classify_reloc::reloc_size;
+ static const int sh_type = Classify_reloc::sh_type;
+
+ // Return the symbol referred to by the relocation.
+ static inline unsigned int
+ get_r_sym(const Reltype* reloc)
+ { return Classify_reloc::get_r_sym(reloc); }
+
+ // Return the type of the relocation.
+ static inline unsigned int
+ get_r_type(const Reltype* reloc)
+ { return Classify_reloc::get_r_type(reloc); }
+
// Return the strategy to use for a local symbol which is not a
// section symbol, given the relocation type.
inline Relocatable_relocs::Reloc_strategy
return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
else
{
- Classify_reloc classify;
- switch (classify.get_size_for_reloc(r_type, object))
+ switch (Classify_reloc::get_size_for_reloc(r_type, object))
{
case 0:
return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
{ return Relocatable_relocs::RELOC_COPY; }
};
+// This is a strategy class used with scan_relocatable_relocs
+// and --emit-relocs.
+
+template<typename Classify_reloc>
+class Default_emit_relocs_strategy
+{
+ public:
+ typedef typename Classify_reloc::Reltype Reltype;
+ static const int reloc_size = Classify_reloc::reloc_size;
+ static const int sh_type = Classify_reloc::sh_type;
+
+ // Return the symbol referred to by the relocation.
+ static inline unsigned int
+ get_r_sym(const Reltype* reloc)
+ { return Classify_reloc::get_r_sym(reloc); }
+
+ // Return the type of the relocation.
+ static inline unsigned int
+ get_r_type(const Reltype* reloc)
+ { return Classify_reloc::get_r_type(reloc); }
+
+ // A local non-section symbol.
+ inline Relocatable_relocs::Reloc_strategy
+ local_non_section_strategy(unsigned int, Relobj*, unsigned int)
+ { return Relocatable_relocs::RELOC_COPY; }
+
+ // A local section symbol.
+ inline Relocatable_relocs::Reloc_strategy
+ local_section_strategy(unsigned int, Relobj*)
+ {
+ if (sh_type == elfcpp::SHT_RELA)
+ return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
+ else
+ {
+ // The addend is stored in the section contents. Since this
+ // is not a relocatable link, we are going to apply the
+ // relocation contents to the section as usual. This means
+ // that we have no way to record the original addend. If the
+ // original addend is not zero, there is basically no way for
+ // the user to handle this correctly. Caveat emptor.
+ return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
+ }
+ }
+
+ // A global symbol.
+ inline Relocatable_relocs::Reloc_strategy
+ global_strategy(unsigned int, Relobj*, unsigned int)
+ { return Relocatable_relocs::RELOC_COPY; }
+};
+
// Scan relocs during a relocatable link. This is a default
// definition which should work for most targets.
// Scan_relocatable_reloc must name a class type which provides three
// local_section_strategy. Most targets should be able to use
// Default_scan_relocatable_relocs as this class.
-template<int size, bool big_endian, int sh_type,
- typename Scan_relocatable_reloc>
+template<int size, bool big_endian, typename Scan_relocatable_reloc>
void
scan_relocatable_relocs(
Symbol_table*,
const unsigned char* plocal_syms,
Relocatable_relocs* rr)
{
- typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
- const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
+ typedef typename Scan_relocatable_reloc::Reltype Reltype;
+ const int reloc_size = Scan_relocatable_reloc::reloc_size;
const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
Scan_relocatable_reloc scan;
strategy = Relocatable_relocs::RELOC_DISCARD;
else
{
- typename elfcpp::Elf_types<size>::Elf_WXword r_info =
- reloc.get_r_info();
- const unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
- const unsigned int r_type = elfcpp::elf_r_type<size>(r_info);
+ const unsigned int r_sym = Scan_relocatable_reloc::get_r_sym(&reloc);
+ const unsigned int r_type =
+ Scan_relocatable_reloc::get_r_type(&reloc);
if (r_sym >= local_symbol_count)
strategy = scan.global_strategy(r_type, object, r_sym);
// 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>
+template<int size, bool big_endian, typename Classify_reloc>
void
relocate_relocs(
const Relocate_info<size, big_endian>* relinfo,
size_t reloc_count,
Output_section* 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 view_size,
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;
+ typedef typename Classify_reloc::Reltype Reltype;
+ typedef typename Classify_reloc::Reltype_write Reltype_write;
+ const int reloc_size = Classify_reloc::reloc_size;
const Address invalid_address = static_cast<Address>(0) - 1;
Sized_relobj_file<size, big_endian>* const object = relinfo->object;
unsigned char* pwrite = reloc_view;
+ const bool relocatable = parameters->options().relocatable();
+
for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
{
- Relocatable_relocs::Reloc_strategy strategy = rr->strategy(i);
+ Relocatable_relocs::Reloc_strategy strategy = relinfo->rr->strategy(i);
if (strategy == Relocatable_relocs::RELOC_DISCARD)
continue;
// 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,
+ target->relocate_special_relocatable(relinfo, Classify_reloc::sh_type,
+ prelocs, i, output_section,
offset_in_output_section,
view, view_address,
view_size, pwrite);
Reltype reloc(prelocs);
Reltype_write reloc_write(pwrite);
- typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
- const unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
- const unsigned int r_type = elfcpp::elf_r_type<size>(r_info);
+ const unsigned int r_sym = Classify_reloc::get_r_sym(&reloc);
// Get the new symbol index.
+ Output_section* os = NULL;
unsigned int new_symndx;
if (r_sym < local_count)
{
unsigned int shndx =
object->local_symbol_input_shndx(r_sym, &is_ordinary);
gold_assert(is_ordinary);
- Output_section* os = object->output_section(shndx);
+ os = object->output_section(shndx);
gold_assert(os != NULL);
gold_assert(os->needs_symtab_index());
new_symndx = os->symtab_index();
// 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())
+ if (!relocatable)
{
new_offset += view_address;
if (offset_in_output_section != invalid_address)
}
reloc_write.put_r_offset(new_offset);
- reloc_write.put_r_info(elfcpp::elf_r_info<size>(new_symndx, r_type));
+ Classify_reloc::put_r_info(&reloc_write, &reloc, new_symndx);
// Handle the reloc addend based on the strategy.
if (strategy == Relocatable_relocs::RELOC_COPY)
{
- if (sh_type == elfcpp::SHT_RELA)
- Reloc_types<sh_type, size, big_endian>::
- copy_reloc_addend(&reloc_write,
- &reloc);
+ if (Classify_reloc::sh_type == elfcpp::SHT_RELA)
+ Classify_reloc::put_r_addend(&reloc_write,
+ Classify_reloc::get_r_addend(&reloc));
}
else
{
{
case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA:
{
- typename elfcpp::Elf_types<size>::Elf_Swxword addend;
- addend = Reloc_types<sh_type, size, big_endian>::
- get_reloc_addend(&reloc);
+ typename elfcpp::Elf_types<size>::Elf_Swxword addend
+ = Classify_reloc::get_r_addend(&reloc);
addend = psymval->value(object, addend);
- Reloc_types<sh_type, size, big_endian>::
- set_reloc_addend(&reloc_write, addend);
+ // In a relocatable link, the symbol value is relative to
+ // the start of the output section. For a non-relocatable
+ // link, we need to adjust the addend.
+ if (!relocatable)
+ {
+ gold_assert(os != NULL);
+ addend -= os->address();
+ }
+ Classify_reloc::put_r_addend(&reloc_write, addend);
}
break;