// target.h -- target support for gold -*- C++ -*-
-// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013
+// Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
class Relobj;
template<int size, bool big_endian>
class Sized_relobj;
+template<int size, bool big_endian>
+class Sized_relobj_file;
class Relocatable_relocs;
template<int size, bool big_endian>
-class Relocate_info;
+struct Relocate_info;
class Reloc_symbol_changes;
class Symbol;
template<int size>
class Sized_symbol;
class Symbol_table;
+class Output_data;
+class Output_data_got_base;
class Output_section;
class Input_objects;
+class Task;
+struct Symbol_location;
// The abstract class for target specific handling.
virtual ~Target()
{ }
- // Virtual function which is set to return true by a target if
- // it can use relocation types to determine if a function's
- // pointer is taken.
- virtual bool
- can_check_for_function_pointers() const
- { return false; }
-
// Return the bit size that this target implements. This should
// return 32 or 64.
int
this->abi_pagesize());
}
+ // Return whether PF_X segments must contain nothing but the contents of
+ // SHF_EXECINSTR sections (no non-executable data, no headers).
+ bool
+ isolate_execinstr() const
+ { return this->pti_->isolate_execinstr; }
+
+ uint64_t
+ rosegment_gap() const
+ { return this->pti_->rosegment_gap; }
+
// If we see some object files with .note.GNU-stack sections, and
// some objects files without them, this returns whether we should
// consider the object files without them to imply that the stack
// Adjust the output file header before it is written out. VIEW
// points to the header in external form. LEN is the length.
void
- adjust_elf_header(unsigned char* view, int len) const
+ adjust_elf_header(unsigned char* view, int len)
{ return this->do_adjust_elf_header(view, len); }
+ // Return address and size to plug into eh_frame FDEs associated with a PLT.
+ void
+ plt_fde_location(const Output_data* plt, unsigned char* oview,
+ uint64_t* address, off_t* len) const
+ { return this->do_plt_fde_location(plt, oview, address, len); }
+
// Return whether NAME is a local label name. This is used to implement the
// --discard-locals options.
bool
reloc_addend(void* arg, unsigned int type, uint64_t addend) const
{ return this->do_reloc_addend(arg, type, addend); }
+ // Return the PLT address to use for a global symbol.
+ uint64_t
+ plt_address_for_global(const Symbol* sym) const
+ { return this->do_plt_address_for_global(sym); }
+
+ // Return the PLT address to use for a local symbol.
+ uint64_t
+ plt_address_for_local(const Relobj* object, unsigned int symndx) const
+ { return this->do_plt_address_for_local(object, symndx); }
+
+ // Return the offset to use for the GOT_INDX'th got entry which is
+ // for a local tls symbol specified by OBJECT, SYMNDX.
+ int64_t
+ tls_offset_for_local(const Relobj* object,
+ unsigned int symndx,
+ unsigned int got_indx) const
+ { return do_tls_offset_for_local(object, symndx, got_indx); }
+
+ // Return the offset to use for the GOT_INDX'th got entry which is
+ // for global tls symbol GSYM.
+ int64_t
+ tls_offset_for_global(Symbol* gsym, unsigned int got_indx) const
+ { return do_tls_offset_for_global(gsym, got_indx); }
+
+ // For targets that use function descriptors, if LOC is the location
+ // of a function, modify it to point at the function entry location.
+ void
+ function_location(Symbol_location* loc) const
+ { return do_function_location(loc); }
+
+ // Return whether this target can use relocation types to determine
+ // if a function's address is taken.
+ bool
+ can_check_for_function_pointers() const
+ { return this->do_can_check_for_function_pointers(); }
+
+ // Return whether a relocation to a merged section can be processed
+ // to retrieve the contents.
+ bool
+ can_icf_inline_merge_sections () const
+ { return this->pti_->can_icf_inline_merge_sections; }
+
+ // Whether a section called SECTION_NAME may have function pointers to
+ // sections not eligible for safe ICF folding.
+ virtual bool
+ section_may_have_icf_unsafe_pointers(const char* section_name) const
+ { return this->do_section_may_have_icf_unsafe_pointers(section_name); }
+
+ // Return the base to use for the PC value in an FDE when it is
+ // encoded using DW_EH_PE_datarel. This does not appear to be
+ // documented anywhere, but it is target specific. Any use of
+ // DW_EH_PE_datarel in gcc requires defining a special macro
+ // (ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX) to output the value.
+ uint64_t
+ ehframe_datarel_base() const
+ { return this->do_ehframe_datarel_base(); }
+
// Return true if a reference to SYM from a reloc of type R_TYPE
// means that the current function may call an object compiled
// without -fsplit-stack. SYM is known to be defined in an object
// Perform a relaxation pass. Return true if layout may be changed.
bool
relax(int pass, const Input_objects* input_objects, Symbol_table* symtab,
- Layout* layout)
+ Layout* layout, const Task* task)
{
// Run the dummy relaxation pass twice if relaxation debugging is enabled.
if (is_debugging_enabled(DEBUG_RELAXATION))
return pass < 2;
- return this->do_relax(pass, input_objects, symtab, layout);
- }
+ return this->do_relax(pass, input_objects, symtab, layout, task);
+ }
// Return the target-specific name of attributes section. This is
// NULL if a target does not use attributes section or if it uses
{
return ((this->pti_->attributes_section != NULL
&& strcmp(name, this->pti_->attributes_section) == 0)
- || strcmp(name, ".gnu.attributes") == 0);
+ || strcmp(name, ".gnu.attributes") == 0);
}
// Return a bit mask of argument types for attribute with TAG.
// which may be used for expensive, target-specific initialization.
void
select_as_default_target()
- { this->do_select_as_default_target(); }
+ { this->do_select_as_default_target(); }
+
+ // Return the value to store in the EI_OSABI field in the ELF
+ // header.
+ elfcpp::ELFOSABI
+ osabi() const
+ { return this->osabi_; }
+
+ // Set the value to store in the EI_OSABI field in the ELF header.
+ void
+ set_osabi(elfcpp::ELFOSABI osabi)
+ { this->osabi_ = osabi; }
+
+ // Define target-specific standard symbols.
+ void
+ define_standard_symbols(Symbol_table* symtab, Layout* layout)
+ { this->do_define_standard_symbols(symtab, layout); }
+
+ // Return the output section name to use given an input section
+ // name, or NULL if no target specific name mapping is required.
+ // Set *PLEN to the length of the name if returning non-NULL.
+ const char*
+ output_section_name(const Relobj* relobj,
+ const char* name,
+ size_t* plen) const
+ { return this->do_output_section_name(relobj, name, plen); }
+
+ // Add any special sections for this symbol to the gc work list.
+ void
+ gc_mark_symbol(Symbol_table* symtab, Symbol* sym) const
+ { this->do_gc_mark_symbol(symtab, sym); }
+
+ // Return the name of the entry point symbol.
+ const char*
+ entry_symbol_name() const
+ { return this->pti_->entry_symbol_name; }
protected:
// This struct holds the constant information for a child class. We
// Whether an object file with no .note.GNU-stack sections implies
// that the stack should be executable.
bool is_default_stack_executable;
+ // Whether a relocation to a merged section can be processed to
+ // retrieve the contents.
+ bool can_icf_inline_merge_sections;
// Prefix character to strip when checking for wrapping.
char wrap_char;
// The default dynamic linker name.
uint64_t abi_pagesize;
// The common page size used by actual implementations.
uint64_t common_pagesize;
+ // Whether PF_X segments must contain nothing but the contents of
+ // SHF_EXECINSTR sections (no non-executable data, no headers).
+ bool isolate_execinstr;
+ // If nonzero, distance from the text segment to the read-only segment.
+ uint64_t rosegment_gap;
// The special section index for small common symbols; SHN_UNDEF
// if none.
elfcpp::Elf_Half small_common_shndx;
const char* attributes_section;
// Vendor name of vendor attributes.
const char* attributes_vendor;
+ // Name of the main entry point to the program.
+ const char* entry_symbol_name;
};
Target(const Target_info* pti)
: pti_(pti), processor_specific_flags_(0),
- are_processor_specific_flags_set_(false)
+ are_processor_specific_flags_set_(false), osabi_(elfcpp::ELFOSABI_NONE)
{ }
// Virtual function which may be implemented by the child class.
// Adjust the output file header before it is written out. VIEW
// points to the header in external form. LEN is the length, and
// will be one of the values of elfcpp::Elf_sizes<size>::ehdr_size.
- // By default, we do nothing.
+ // By default, we set the EI_OSABI field if requested (in
+ // Sized_target).
virtual void
- do_adjust_elf_header(unsigned char*, int) const
- { }
+ do_adjust_elf_header(unsigned char*, int) = 0;
- // Virtual function which may be overriden by the child class.
+ // Return address and size to plug into eh_frame FDEs associated with a PLT.
+ virtual void
+ do_plt_fde_location(const Output_data* plt, unsigned char* oview,
+ uint64_t* address, off_t* len) const;
+
+ // Virtual function which may be overridden by the child class.
virtual bool
do_is_local_label_name(const char*) const;
do_reloc_symbol_index(void*, unsigned int) const
{ gold_unreachable(); }
- // Virtual function that must be overidden by a target which uses
+ // Virtual function that must be overridden by a target which uses
// target specific relocations.
virtual uint64_t
do_reloc_addend(void*, unsigned int, uint64_t) const
{ gold_unreachable(); }
+ // Virtual functions that must be overridden by a target that uses
+ // STT_GNU_IFUNC symbols.
+ virtual uint64_t
+ do_plt_address_for_global(const Symbol*) const
+ { gold_unreachable(); }
+
+ virtual uint64_t
+ do_plt_address_for_local(const Relobj*, unsigned int) const
+ { gold_unreachable(); }
+
+ virtual int64_t
+ do_tls_offset_for_local(const Relobj*, unsigned int, unsigned int) const
+ { gold_unreachable(); }
+
+ virtual int64_t
+ do_tls_offset_for_global(Symbol*, unsigned int) const
+ { gold_unreachable(); }
+
+ virtual void
+ do_function_location(Symbol_location*) const = 0;
+
+ // Virtual function which may be overriden by the child class.
+ virtual bool
+ do_can_check_for_function_pointers() const
+ { return false; }
+
+ // Virtual function which may be overridden by the child class. We
+ // recognize some default sections for which we don't care whether
+ // they have function pointers.
+ virtual bool
+ do_section_may_have_icf_unsafe_pointers(const char* section_name) const
+ {
+ // We recognize sections for normal vtables, construction vtables and
+ // EH frames.
+ return (!is_prefix_of(".rodata._ZTV", section_name)
+ && !is_prefix_of(".data.rel.ro._ZTV", section_name)
+ && !is_prefix_of(".rodata._ZTC", section_name)
+ && !is_prefix_of(".data.rel.ro._ZTC", section_name)
+ && !is_prefix_of(".eh_frame", section_name));
+ }
+
+ virtual uint64_t
+ do_ehframe_datarel_base() const
+ { gold_unreachable(); }
+
// Virtual function which may be overridden by the child class. The
// default implementation is that any function not defined by the
// ABI is a call to a non-split function.
this->processor_specific_flags_ = flags;
this->are_processor_specific_flags_set_ = true;
}
-
+
#ifdef HAVE_TARGET_32_LITTLE
- // Virtual functions which may be overriden by the child class.
+ // Virtual functions which may be overridden by the child class.
virtual Object*
do_make_elf_object(const std::string&, Input_file*, off_t,
const elfcpp::Ehdr<32, false>&);
#endif
#ifdef HAVE_TARGET_32_BIG
- // Virtual functions which may be overriden by the child class.
+ // Virtual functions which may be overridden by the child class.
virtual Object*
do_make_elf_object(const std::string&, Input_file*, off_t,
const elfcpp::Ehdr<32, true>&);
#endif
#ifdef HAVE_TARGET_64_LITTLE
- // Virtual functions which may be overriden by the child class.
+ // Virtual functions which may be overridden by the child class.
virtual Object*
do_make_elf_object(const std::string&, Input_file*, off_t,
const elfcpp::Ehdr<64, false>& ehdr);
#endif
#ifdef HAVE_TARGET_64_BIG
- // Virtual functions which may be overriden by the child class.
+ // Virtual functions which may be overridden by the child class.
virtual Object*
do_make_elf_object(const std::string& name, Input_file* input_file,
off_t offset, const elfcpp::Ehdr<64, true>& ehdr);
#endif
- // Virtual functions which may be overriden by the child class.
+ // Virtual functions which may be overridden by the child class.
virtual Output_section*
do_make_output_section(const char* name, elfcpp::Elf_Word type,
elfcpp::Elf_Xword flags);
- // Virtual function which may be overriden by the child class.
+ // Virtual function which may be overridden by the child class.
virtual bool
do_may_relax() const
{ return parameters->options().relax(); }
- // Virtual function which may be overriden by the child class.
+ // Virtual function which may be overridden by the child class.
virtual bool
- do_relax(int, const Input_objects*, Symbol_table*, Layout*)
+ do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*)
{ return false; }
// A function for targets to call. Return whether BYTES/LEN matches
set_view_to_nop(unsigned char* view, section_size_type view_size,
section_offset_type offset, size_t len) const;
- // This must be overriden by the child class if it has target-specific
- // attributes subsection in the attribute section.
+ // This must be overridden by the child class if it has target-specific
+ // attributes subsection in the attribute section.
virtual int
do_attribute_arg_type(int) const
{ gold_unreachable(); }
do_select_as_default_target()
{ }
+ // This may be overridden by the child class.
+ virtual void
+ do_define_standard_symbols(Symbol_table*, Layout*)
+ { }
+
+ // This may be overridden by the child class.
+ virtual const char*
+ do_output_section_name(const Relobj*, const char*, size_t*) const
+ { return NULL; }
+
+ // This may be overridden by the child class.
+ virtual void
+ do_gc_mark_symbol(Symbol_table*, Symbol*) const
+ { }
+
private:
// The implementations of the four do_make_elf_object virtual functions are
// almost identical except for their sizes and endianness. We use a template.
elfcpp::Elf_Word processor_specific_flags_;
// Whether the processor-specific flags are set at least once.
bool are_processor_specific_flags_set_;
+ // If not ELFOSABI_NONE, the value to put in the EI_OSABI field of
+ // the ELF header. This is handled at this level because it is
+ // OS-specific rather than processor-specific.
+ elfcpp::ELFOSABI osabi_;
};
// The abstract class for a specific size and endianness of target.
virtual void
gc_process_relocs(Symbol_table* symtab,
Layout* layout,
- Sized_relobj<size, big_endian>* object,
+ Sized_relobj_file<size, big_endian>* object,
unsigned int data_shndx,
unsigned int sh_type,
const unsigned char* prelocs,
virtual void
scan_relocs(Symbol_table* symtab,
Layout* layout,
- Sized_relobj<size, big_endian>* object,
+ Sized_relobj_file<size, big_endian>* object,
unsigned int data_shndx,
unsigned int sh_type,
const unsigned char* prelocs,
virtual void
scan_relocatable_relocs(Symbol_table* symtab,
Layout* layout,
- Sized_relobj<size, big_endian>* object,
+ Sized_relobj_file<size, big_endian>* object,
unsigned int data_shndx,
unsigned int sh_type,
const unsigned char* prelocs,
const unsigned char* plocal_symbols,
Relocatable_relocs*) = 0;
- // Relocate a section during a relocatable link. The parameters are
- // like relocate_section, with additional parameters for the view of
- // the output reloc section.
+ // Emit relocations for a section during a relocatable link, and for
+ // --emit-relocs. The parameters are like relocate_section, with
+ // additional parameters for the view of the output reloc section.
+ virtual void
+ relocate_relocs(const Relocate_info<size, big_endian>*,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ typename elfcpp::Elf_types<size>::Elf_Off
+ offset_in_output_section,
+ const Relocatable_relocs*,
+ unsigned char* view,
+ typename elfcpp::Elf_types<size>::Elf_Addr view_address,
+ section_size_type view_size,
+ unsigned char* reloc_view,
+ section_size_type reloc_view_size) = 0;
+
+ // Perform target-specific processing in a relocatable link. This is
+ // only used if we use the relocation strategy RELOC_SPECIAL.
+ // RELINFO points to a Relocation_info structure. SH_TYPE is the relocation
+ // section type. PRELOC_IN points to the original relocation. RELNUM is
+ // the index number of the relocation in the relocation section.
+ // OUTPUT_SECTION is the output section to which the relocation is applied.
+ // OFFSET_IN_OUTPUT_SECTION is the offset of the relocation input section
+ // within the output section. VIEW points to the output view of the
+ // output section. VIEW_ADDRESS is output address of the view. VIEW_SIZE
+ // is the size of the output view and PRELOC_OUT points to the new
+ // relocation in the output object.
+ //
+ // A target only needs to override this if the generic code in
+ // target-reloc.h cannot handle some relocation types.
+
+ virtual void
+ relocate_special_relocatable(const Relocate_info<size, big_endian>*
+ /*relinfo */,
+ unsigned int /* sh_type */,
+ const unsigned char* /* preloc_in */,
+ size_t /* relnum */,
+ Output_section* /* output_section */,
+ typename elfcpp::Elf_types<size>::Elf_Off
+ /* offset_in_output_section */,
+ unsigned char* /* view */,
+ typename elfcpp::Elf_types<size>::Elf_Addr
+ /* view_address */,
+ section_size_type /* view_size */,
+ unsigned char* /* preloc_out*/)
+ { gold_unreachable(); }
+
+ // Return the number of entries in the GOT. This is only used for
+ // laying out the incremental link info sections. A target needs
+ // to implement this to support incremental linking.
+
+ virtual unsigned int
+ got_entry_count() const
+ { gold_unreachable(); }
+
+ // Return the number of entries in the PLT. This is only used for
+ // laying out the incremental link info sections. A target needs
+ // to implement this to support incremental linking.
+
+ virtual unsigned int
+ plt_entry_count() const
+ { gold_unreachable(); }
+
+ // Return the offset of the first non-reserved PLT entry. This is
+ // only used for laying out the incremental link info sections.
+ // A target needs to implement this to support incremental linking.
+
+ virtual unsigned int
+ first_plt_entry_offset() const
+ { gold_unreachable(); }
+
+ // Return the size of each PLT entry. This is only used for
+ // laying out the incremental link info sections. A target needs
+ // to implement this to support incremental linking.
+
+ virtual unsigned int
+ plt_entry_size() const
+ { gold_unreachable(); }
+
+ // Create the GOT and PLT sections for an incremental update.
+ // A target needs to implement this to support incremental linking.
+
+ virtual Output_data_got_base*
+ init_got_plt_for_update(Symbol_table*,
+ Layout*,
+ unsigned int /* got_count */,
+ unsigned int /* plt_count */)
+ { gold_unreachable(); }
+
+ // Reserve a GOT entry for a local symbol, and regenerate any
+ // necessary dynamic relocations.
virtual void
- relocate_for_relocatable(const Relocate_info<size, big_endian>*,
- unsigned int sh_type,
- const unsigned char* prelocs,
- size_t reloc_count,
- Output_section* output_section,
- off_t offset_in_output_section,
- const Relocatable_relocs*,
- unsigned char* view,
- typename elfcpp::Elf_types<size>::Elf_Addr
- view_address,
- section_size_type view_size,
- unsigned char* reloc_view,
- section_size_type reloc_view_size) = 0;
+ reserve_local_got_entry(unsigned int /* got_index */,
+ Sized_relobj<size, big_endian>* /* obj */,
+ unsigned int /* r_sym */,
+ unsigned int /* got_type */)
+ { gold_unreachable(); }
+
+ // Reserve a GOT entry for a global symbol, and regenerate any
+ // necessary dynamic relocations.
+ virtual void
+ reserve_global_got_entry(unsigned int /* got_index */, Symbol* /* gsym */,
+ unsigned int /* got_type */)
+ { gold_unreachable(); }
+
+ // Register an existing PLT entry for a global symbol.
+ // A target needs to implement this to support incremental linking.
+
+ virtual void
+ register_global_plt_entry(Symbol_table*, Layout*,
+ unsigned int /* plt_index */,
+ Symbol*)
+ { gold_unreachable(); }
+
+ // Force a COPY relocation for a given symbol.
+ // A target needs to implement this to support incremental linking.
+
+ virtual void
+ emit_copy_reloc(Symbol_table*, Symbol*, Output_section*, off_t)
+ { gold_unreachable(); }
+
+ // Apply an incremental relocation.
+
+ virtual void
+ apply_relocation(const Relocate_info<size, big_endian>* /* relinfo */,
+ 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 */)
+ { gold_unreachable(); }
+
+ // Handle target specific gc actions when adding a gc reference from
+ // SRC_OBJ, SRC_SHNDX to a location specified by DST_OBJ, DST_SHNDX
+ // and DST_OFF.
+ void
+ gc_add_reference(Symbol_table* symtab,
+ Object* src_obj,
+ unsigned int src_shndx,
+ Object* dst_obj,
+ unsigned int dst_shndx,
+ typename elfcpp::Elf_types<size>::Elf_Addr dst_off) const
+ {
+ this->do_gc_add_reference(symtab, src_obj, src_shndx,
+ dst_obj, dst_shndx, dst_off);
+ }
protected:
Sized_target(const Target::Target_info* pti)
gold_assert(pti->size == size);
gold_assert(pti->is_big_endian ? big_endian : !big_endian);
}
+
+ // Set the EI_OSABI field if requested.
+ virtual void
+ do_adjust_elf_header(unsigned char*, int);
+
+ // Handle target specific gc actions when adding a gc reference.
+ virtual void
+ do_gc_add_reference(Symbol_table*, Object*, unsigned int,
+ Object*, unsigned int,
+ typename elfcpp::Elf_types<size>::Elf_Addr) const
+ { }
+
+ virtual void
+ do_function_location(Symbol_location*) const
+ { }
};
} // End namespace gold.