// target.h -- target support for gold -*- C++ -*-
-// Copyright 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
+// Copyright (C) 2006-2020 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#include "elfcpp.h"
#include "options.h"
#include "parameters.h"
+#include "stringpool.h"
#include "debug.h"
namespace gold
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;
-template<int size, bool big_endian>
-class Output_data_got;
+class Output_data_got_base;
class Output_section;
class Input_objects;
class Task;
+struct Symbol_location;
+class Versions;
// The abstract class for target specific handling.
{ return this->pti_->dynamic_linker; }
// Return the default address to use for the text segment.
+ // If a -z max-page-size argument has set the ABI page size
+ // to a value larger than the default starting address,
+ // bump the starting address up to the page size, to avoid
+ // misaligning the text segment in the file.
uint64_t
default_text_segment_address() const
- { return this->pti_->default_text_segment_address; }
+ {
+ uint64_t addr = this->pti_->default_text_segment_address;
+ uint64_t pagesize = this->abi_pagesize();
+ if (addr < pagesize)
+ addr = pagesize;
+ return addr;
+ }
// Return the ABI specified page size.
uint64_t
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 section to use for a global symbol. This is used
- // for STT_GNU_IFUNC symbols.
- Output_data*
- plt_section_for_global(const Symbol* sym) const
- { return this->do_plt_section_for_global(sym); }
+ // 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 section to use for a local symbol. This is used
- // for STT_GNU_IFUNC symbols.
- Output_data*
- plt_section_for_local(const Relobj* object, unsigned int symndx) const
- { return this->do_plt_section_for_local(object, symndx); }
+ // 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.
ehframe_datarel_base() const
{ return this->do_ehframe_datarel_base(); }
- // Return true if a reference to SYM from a reloc of type R_TYPE
+ // Return true if a reference to SYM from a reloc at *PRELOC
// means that the current function may call an object compiled
// without -fsplit-stack. SYM is known to be defined in an object
// compiled without -fsplit-stack.
bool
- is_call_to_non_split(const Symbol* sym, unsigned int r_type) const
- { return this->do_is_call_to_non_split(sym, r_type); }
+ is_call_to_non_split(const Symbol* sym, const unsigned char* preloc,
+ const unsigned char* view,
+ section_size_type view_size) const
+ { return this->do_is_call_to_non_split(sym, preloc, view, view_size); }
// A function starts at OFFSET in section SHNDX in OBJECT. That
// function was compiled with -fsplit-stack, but it refers to a
void
calls_non_split(Relobj* object, unsigned int shndx,
section_offset_type fnoffset, section_size_type fnsize,
+ const unsigned char* prelocs, size_t reloc_count,
unsigned char* view, section_size_type view_size,
std::string* from, std::string* to) const
{
- this->do_calls_non_split(object, shndx, fnoffset, fnsize, view, view_size,
+ this->do_calls_non_split(object, shndx, fnoffset, fnsize,
+ prelocs, reloc_count, view, view_size,
from, to);
}
return pass < 2;
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.
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; }
+
+ // Return the size in bits of SHT_HASH entry.
+ int
+ hash_entry_size() const
+ { return this->pti_->hash_entry_size; }
+
+ // Return the section type to use for unwind sections.
+ unsigned int
+ unwind_section_type() const
+ { return this->pti_->unwind_section_type; }
+
+ // Whether the target has a custom set_dynsym_indexes method.
+ bool
+ has_custom_set_dynsym_indexes() const
+ { return this->do_has_custom_set_dynsym_indexes(); }
+
+ // Custom set_dynsym_indexes method for a target.
+ unsigned int
+ set_dynsym_indexes(std::vector<Symbol*>* dyn_symbols, unsigned int index,
+ std::vector<Symbol*>* syms, Stringpool* dynpool,
+ Versions* versions, Symbol_table* symtab) const
+ {
+ return this->do_set_dynsym_indexes(dyn_symbols, index, syms, dynpool,
+ versions, symtab);
+ }
+
+ // Get the custom dynamic tag value.
+ unsigned int
+ dynamic_tag_custom_value(elfcpp::DT tag) const
+ { return this->do_dynamic_tag_custom_value(tag); }
+
+ // Adjust the value written to the dynamic symbol table.
+ void
+ adjust_dyn_symbol(const Symbol* sym, unsigned char* view) const
+ { this->do_adjust_dyn_symbol(sym, view); }
+
+ // Return whether to include the section in the link.
+ bool
+ should_include_section(elfcpp::Elf_Word sh_type) const
+ { return this->do_should_include_section(sh_type); }
+
+ // Finalize the target-specific properties in the .note.gnu.property section.
+ void
+ finalize_gnu_properties(Layout* layout) const
+ { this->do_finalize_gnu_properties(layout); }
+
protected:
// This struct holds the constant information for a child class. We
// use a struct to avoid the overhead of virtual function calls for
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;
+ // Size (in bits) of SHT_HASH entry. Always equal to 32, except for
+ // 64-bit S/390.
+ const int hash_entry_size;
+ // Processor-specific section type for ".eh_frame" (unwind) sections.
+ // SHT_PROGBITS if there is no special section type.
+ const unsigned int unwind_section_type;
};
Target(const Target_info* pti)
// By default, we set the EI_OSABI field if requested (in
// Sized_target).
virtual void
- do_adjust_elf_header(unsigned char*, int) const = 0;
+ do_adjust_elf_header(unsigned char*, int) = 0;
+
+ // 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
// Virtual functions that must be overridden by a target that uses
// STT_GNU_IFUNC symbols.
- virtual Output_data*
- do_plt_section_for_global(const Symbol*) const
+ 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 Output_data*
- do_plt_section_for_local(const Relobj*, unsigned int) const
+ 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
// default implementation is that any function not defined by the
// ABI is a call to a non-split function.
virtual bool
- do_is_call_to_non_split(const Symbol* sym, unsigned int) const;
+ do_is_call_to_non_split(const Symbol* sym, const unsigned char*,
+ const unsigned char*, section_size_type) const;
// Virtual function which may be overridden by the child class.
virtual void
do_calls_non_split(Relobj* object, unsigned int, section_offset_type,
- section_size_type, unsigned char*, section_size_type,
+ section_size_type, const unsigned char*, size_t,
+ unsigned char*, section_size_type,
std::string*, std::string*) const;
// make_elf_object hooks. There are four versions of these for
this->processor_specific_flags_ = flags;
this->are_processor_specific_flags_set_ = true;
}
-
+
#ifdef HAVE_TARGET_32_LITTLE
// Virtual functions which may be overridden by the child class.
virtual Object*
section_offset_type offset, size_t len) const;
// This must be overridden by the child class if it has target-specific
- // attributes subsection in the attribute section.
+ // 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
+ { }
+
+ // This may be overridden by the child class.
+ virtual bool
+ do_has_custom_set_dynsym_indexes() const
+ { return false; }
+
+ // This may be overridden by the child class.
+ virtual unsigned int
+ do_set_dynsym_indexes(std::vector<Symbol*>*, unsigned int,
+ std::vector<Symbol*>*, Stringpool*, Versions*,
+ Symbol_table*) const
+ { gold_unreachable(); }
+
+ // This may be overridden by the child class.
+ virtual unsigned int
+ do_dynamic_tag_custom_value(elfcpp::DT) const
+ { gold_unreachable(); }
+
+ // This may be overridden by the child class.
+ virtual void
+ do_adjust_dyn_symbol(const Symbol*, unsigned char*) const
+ { }
+
+ // This may be overridden by the child class.
+ virtual bool
+ do_should_include_section(elfcpp::Elf_Word) const
+ { return true; }
+
+ // Finalize the target-specific properties in the .note.gnu.property section.
+ virtual void
+ do_finalize_gnu_properties(Layout*) 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.
// symbol table. This will only be called if has_make_symbol()
// returns true.
virtual Sized_symbol<size>*
- make_symbol() const
+ make_symbol(const char*, elfcpp::STT, Object*, unsigned int, uint64_t)
{ gold_unreachable(); }
// Resolve a symbol for the target. This should be overridden by a
// pre-existing symbol. SYM is the new symbol, seen in OBJECT.
// VERSION is the version of SYM. This will only be called if
// has_resolve() returns true.
- virtual void
+ virtual bool
resolve(Symbol*, const elfcpp::Sym<size, big_endian>&, Object*,
const char*)
{ gold_unreachable(); }
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.
+ // Scan the relocs for --emit-relocs. The parameters are
+ // like scan_relocatable_relocs.
+ virtual void
+ emit_relocs_scan(Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj_file<size, big_endian>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_syms,
+ Relocatable_relocs* rr) = 0;
+
+ // 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_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;
-
+ 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,
+ 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
const unsigned char* /* preloc_in */,
size_t /* relnum */,
Output_section* /* output_section */,
- off_t /* offset_in_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.
plt_entry_size() const
{ gold_unreachable(); }
+ // Return the size of each GOT entry. This is only used for
+ // laying out the incremental link info sections. A target needs
+ // to implement this if its GOT size is different.
+
+ virtual unsigned int
+ got_entry_size() const
+ { return size / 8; }
+
// Create the GOT and PLT sections for an incremental update.
// A target needs to implement this to support incremental linking.
- virtual Output_data_got<size, big_endian>*
+ virtual Output_data_got_base*
init_got_plt_for_update(Symbol_table*,
Layout*,
unsigned int /* got_count */,
// A target needs to implement this to support incremental linking.
virtual void
- register_global_plt_entry(unsigned int /* plt_index */,
+ register_global_plt_entry(Symbol_table*, Layout*,
+ unsigned int /* plt_index */,
Symbol*)
{ gold_unreachable(); }
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,
+ Relobj* src_obj,
+ unsigned int src_shndx,
+ Relobj* 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);
+ }
+
+ // Return the r_sym field from a relocation.
+ // Most targets can use the default version of this routine,
+ // but some targets have a non-standard r_info field, and will
+ // need to provide a target-specific version.
+ virtual unsigned int
+ get_r_sym(const unsigned char* preloc) const
+ {
+ // Since REL and RELA relocs share the same structure through
+ // the r_info field, we can just use REL here.
+ elfcpp::Rel<size, big_endian> rel(preloc);
+ return elfcpp::elf_r_sym<size>(rel.get_r_info());
+ }
+
+ // Record a target-specific program property in the .note.gnu.property
+ // section.
+ virtual void
+ record_gnu_property(unsigned int, unsigned int, size_t,
+ const unsigned char*, const Object*)
+ { }
+
+ // Merge the target-specific program properties from the current object.
+ virtual void
+ merge_gnu_properties(const Object*)
+ { }
+
protected:
Sized_target(const Target::Target_info* pti)
: Target(pti)
// Set the EI_OSABI field if requested.
virtual void
- do_adjust_elf_header(unsigned char*, int) const;
+ 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*, Relobj*, unsigned int,
+ Relobj*, unsigned int,
+ typename elfcpp::Elf_types<size>::Elf_Addr) const
+ { }
+
+ virtual void
+ do_function_location(Symbol_location*) const
+ { }
};
} // End namespace gold.
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