// object.h -- support for an object file for linking in gold -*- C++ -*-
-// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
class Task;
class Cref;
class Layout;
+class Output_data;
class Output_section;
class Output_file;
class Output_symtab_xindex;
section_addralign(unsigned int shndx)
{ return this->do_section_addralign(shndx); }
+ // Return the output section given a section index.
+ Output_section*
+ output_section(unsigned int shndx) const
+ { return this->do_output_section(shndx); }
+
+ // Given a section index, return the offset in the Output_section.
+ // The return value will be -1U if the section is specially mapped,
+ // such as a merge section.
+ uint64_t
+ output_section_offset(unsigned int shndx) const
+ { return this->do_output_section_offset(shndx); }
+
// Read the symbol information.
void
read_symbols(Read_symbols_data* sd)
// Add symbol information to the global symbol table.
Archive::Should_include
- should_include_member(Symbol_table* symtab, Read_symbols_data* sd,
- std::string* why)
- { return this->do_should_include_member(symtab, sd, why); }
+ should_include_member(Symbol_table* symtab, Layout* layout,
+ Read_symbols_data* sd, std::string* why)
+ { return this->do_should_include_member(symtab, layout, sd, why); }
// Functions and types for the elfcpp::Elf_file interface. This
// permit us to use Object as the File template parameter for
section_size_type* uncompressed_size) const
{ return this->do_section_is_compressed(shndx, uncompressed_size); }
+ // Return the index of the first incremental relocation for symbol SYMNDX.
+ unsigned int
+ get_incremental_reloc_base(unsigned int symndx) const
+ { return this->do_get_incremental_reloc_base(symndx); }
+
+ // Return the number of incremental relocations for symbol SYMNDX.
+ unsigned int
+ get_incremental_reloc_count(unsigned int symndx) const
+ { return this->do_get_incremental_reloc_count(symndx); }
+
protected:
// Returns NULL for Objects that are not plugin objects. This method
// is overridden in the Pluginobj class.
do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*) = 0;
virtual Archive::Should_include
- do_should_include_member(Symbol_table* symtab, Read_symbols_data*,
+ do_should_include_member(Symbol_table* symtab, Layout*, Read_symbols_data*,
std::string* why) = 0;
// Return the location of the contents of a section. Implemented by
virtual uint64_t
do_section_addralign(unsigned int shndx) = 0;
+ // Return the output section given a section index--implemented
+ // by child class.
+ virtual Output_section*
+ do_output_section(unsigned int) const
+ { gold_unreachable(); }
+
+ // Get the offset of a section--implemented by child class.
+ virtual uint64_t
+ do_output_section_offset(unsigned int) const
+ { gold_unreachable(); }
+
// Return the Xindex structure to use.
virtual Xindex*
do_initialize_xindex() = 0;
Symbol_table*);
// If NAME is the name of the special section which indicates that
- // this object was compiled with -fstack-split, mark it accordingly,
+ // this object was compiled with -fsplit-stack, mark it accordingly,
// and return true. Otherwise return false.
bool
handle_split_stack_section(const char* name);
do_section_is_compressed(unsigned int, section_size_type*) const
{ return false; }
+ // Return the index of the first incremental relocation for symbol SYMNDX--
+ // implemented by child class.
+ virtual unsigned int
+ do_get_incremental_reloc_base(unsigned int) const
+ { gold_unreachable(); }
+
+ // Return the number of incremental relocations for symbol SYMNDX--
+ // implemented by child class.
+ virtual unsigned int
+ do_get_incremental_reloc_count(unsigned int) const
+ { gold_unreachable(); }
+
private:
// This class may not be copied.
Object(const Object&);
map_to_relocatable_relocs_(NULL),
object_merge_map_(NULL),
relocs_must_follow_section_writes_(false),
- sd_(NULL)
+ sd_(NULL),
+ reloc_counts_(NULL),
+ reloc_bases_(NULL)
{ }
// During garbage collection, the Read_symbols_data pass for
// Decides which section names have to be included in the worklist
// as roots.
bool
- is_section_name_included(const char *name);
+ is_section_name_included(const char* name);
void
copy_symbols_data(Symbols_data* gc_sd, Read_symbols_data* sd,
return this->output_sections_[shndx] != NULL;
}
- // Given a section index, return the corresponding Output_section.
- // The return value will be NULL if the section is not included in
- // the link.
- Output_section*
- output_section(unsigned int shndx) const
- {
- gold_assert(shndx < this->output_sections_.size());
- return this->output_sections_[shndx];
- }
-
// The the output section of the input section with index SHNDX.
// This is only used currently to remove a section from the link in
// relaxation.
this->output_sections_[shndx] = os;
}
- // Given a section index, return the offset in the Output_section.
- // The return value will be -1U if the section is specially mapped,
- // such as a merge section.
- uint64_t
- output_section_offset(unsigned int shndx) const
- { return this->do_output_section_offset(shndx); }
-
// Set the offset of an input section within its output section.
void
set_section_offset(unsigned int shndx, uint64_t off)
layout_deferred_sections(Layout* layout)
{ this->do_layout_deferred_sections(layout); }
+ // Return the index of the first incremental relocation for symbol SYMNDX.
+ virtual unsigned int
+ do_get_incremental_reloc_base(unsigned int symndx) const
+ { return this->reloc_bases_[symndx]; }
+
+ // Return the number of incremental relocations for symbol SYMNDX.
+ virtual unsigned int
+ do_get_incremental_reloc_count(unsigned int symndx) const
+ { return this->reloc_counts_[symndx]; }
+
protected:
// The output section to be used for each input section, indexed by
// the input section number. The output section is NULL if the
virtual void
do_relocate(const Symbol_table* symtab, const Layout*, Output_file* of) = 0;
- // Get the offset of a section--implemented by child class.
- virtual uint64_t
- do_output_section_offset(unsigned int shndx) const = 0;
-
// Set the offset of a section--implemented by child class.
virtual void
do_set_section_offset(unsigned int shndx, uint64_t off) = 0;
virtual void
do_layout_deferred_sections(Layout*) = 0;
+ // Given a section index, return the corresponding Output_section.
+ // The return value will be NULL if the section is not included in
+ // the link.
+ Output_section*
+ do_output_section(unsigned int shndx) const
+ {
+ gold_assert(shndx < this->output_sections_.size());
+ return this->output_sections_[shndx];
+ }
+
// Return the vector mapping input sections to output sections.
Output_sections&
output_sections()
set_relocs_must_follow_section_writes()
{ this->relocs_must_follow_section_writes_ = true; }
+ // Allocate the array for counting incremental relocations.
+ void
+ allocate_incremental_reloc_counts()
+ {
+ unsigned int nsyms = this->do_get_global_symbols()->size();
+ this->reloc_counts_ = new unsigned int[nsyms];
+ gold_assert(this->reloc_counts_ != NULL);
+ memset(this->reloc_counts_, 0, nsyms * sizeof(unsigned int));
+ }
+
+ // Record a relocation in this object referencing global symbol SYMNDX.
+ // Used for tracking incremental link information.
+ void
+ count_incremental_reloc(unsigned int symndx)
+ {
+ unsigned int nsyms = this->do_get_global_symbols()->size();
+ gold_assert(symndx < nsyms);
+ gold_assert(this->reloc_counts_ != NULL);
+ ++this->reloc_counts_[symndx];
+ }
+
+ // Finalize the incremental relocation information.
+ void
+ finalize_incremental_relocs(Layout* layout);
+
+ // Return the index of the next relocation to be written for global symbol
+ // SYMNDX. Only valid after finalize_incremental_relocs() has been called.
+ unsigned int
+ next_incremental_reloc_index(unsigned int symndx)
+ {
+ unsigned int nsyms = this->do_get_global_symbols()->size();
+
+ gold_assert(this->reloc_counts_ != NULL);
+ gold_assert(this->reloc_bases_ != NULL);
+ gold_assert(symndx < nsyms);
+
+ unsigned int counter = this->reloc_counts_[symndx]++;
+ return this->reloc_bases_[symndx] + counter;
+ }
+
private:
// Mapping from input sections to output section.
Output_sections output_sections_;
// Used to store the symbols data computed by the Read_symbols pass.
// Again used during garbage collection when laying out referenced
// sections.
- gold::Symbols_data *sd_;
+ gold::Symbols_data* sd_;
+ // Per-symbol counts of relocations, for incremental links.
+ unsigned int* reloc_counts_;
+ // Per-symbol base indexes of relocations, for incremental links.
+ unsigned int* reloc_bases_;
};
// This class is used to handle relocations against a section symbol
Symbol_value()
: output_symtab_index_(0), output_dynsym_index_(-1U), input_shndx_(0),
is_ordinary_shndx_(false), is_section_symbol_(false),
- is_tls_symbol_(false), has_output_value_(true)
+ is_tls_symbol_(false), is_ifunc_symbol_(false), has_output_value_(true)
{ this->u_.value = 0; }
+ ~Symbol_value()
+ {
+ if (!this->has_output_value_)
+ delete this->u_.merged_symbol_value;
+ }
+
// Get the value of this symbol. OBJECT is the object in which this
// symbol is defined, and ADDEND is an addend to add to the value.
template<bool big_endian>
set_is_tls_symbol()
{ this->is_tls_symbol_ = true; }
- // Return TRUE if this is a TLS symbol.
+ // Return true if this is a TLS symbol.
bool
is_tls_symbol() const
{ return this->is_tls_symbol_; }
+ // Record that this is an IFUNC symbol.
+ void
+ set_is_ifunc_symbol()
+ { this->is_ifunc_symbol_ = true; }
+
+ // Return true if this is an IFUNC symbol.
+ bool
+ is_ifunc_symbol() const
+ { return this->is_ifunc_symbol_; }
+
+ // Return true if this has output value.
+ bool
+ has_output_value() const
+ { return this->has_output_value_; }
+
private:
// The index of this local symbol in the output symbol table. This
// will be 0 if no value has been assigned yet, and the symbol may
unsigned int output_dynsym_index_;
// The section index in the input file in which this symbol is
// defined.
- unsigned int input_shndx_ : 28;
+ unsigned int input_shndx_ : 27;
// Whether the section index is an ordinary index, not a special
// value.
bool is_ordinary_shndx_ : 1;
bool is_section_symbol_ : 1;
// Whether this is a STT_TLS symbol.
bool is_tls_symbol_ : 1;
+ // Whether this is a STT_GNU_IFUNC symbol.
+ bool is_ifunc_symbol_ : 1;
// Whether this symbol has a value for the output file. This is
// normally set to true during Layout::finalize, by
// finalize_local_symbols. It will be false for a section symbol in
return -1U;
}
+ // Return a pointer to the list, or NULL if the list is empty.
+ const Got_offset_list*
+ get_list() const
+ {
+ if (this->got_type_ == -1U)
+ return NULL;
+ return this;
+ }
+
+ // Loop over all GOT offset entries, applying the function F to each.
+ template<typename F>
+ void
+ for_all_got_offsets(F f) const
+ {
+ if (this->got_type_ == -1U)
+ return;
+ for (const Got_offset_list* g = this; g != NULL; g = g->got_next_)
+ f(g->got_type_, g->got_offset_);
+ }
+
private:
unsigned int got_type_;
unsigned int got_offset_;
static const Address invalid_address = static_cast<Address>(0) - 1;
+ enum Compute_final_local_value_status
+ {
+ // No error.
+ CFLV_OK,
+ // An error occurred.
+ CFLV_ERROR,
+ // The local symbol has no output section.
+ CFLV_DISCARDED
+ };
+
Sized_relobj(const std::string& name, Input_file* input_file, off_t offset,
const typename elfcpp::Ehdr<size, big_endian>&);
}
}
+ // Return the GOT offset list for the local symbol SYMNDX.
+ const Got_offset_list*
+ local_got_offset_list(unsigned int symndx) const
+ {
+ Local_got_offsets::const_iterator p =
+ this->local_got_offsets_.find(symndx);
+ if (p == this->local_got_offsets_.end())
+ return NULL;
+ return p->second;
+ }
+
+ // Return whether the local symbol SYMNDX has a PLT offset.
+ bool
+ local_has_plt_offset(unsigned int symndx) const;
+
+ // Return the PLT offset for a local symbol. It is an error to call
+ // this if it doesn't have one.
+ unsigned int
+ local_plt_offset(unsigned int symndx) const;
+
+ // Set the PLT offset of the local symbol SYMNDX.
+ void
+ set_local_plt_offset(unsigned int symndx, unsigned int plt_offset);
+
// Get the offset of input section SHNDX within its output section.
// This is -1 if the input section requires a special mapping, such
// as a merge section. The output section can be found in the
Address
map_to_kept_section(unsigned int shndx, bool* found) const;
+ // Compute final local symbol value. R_SYM is the local symbol index.
+ // LV_IN points to a local symbol value containing the input value.
+ // LV_OUT points to a local symbol value storing the final output value,
+ // which must not be a merged symbol value since before calling this
+ // method to avoid memory leak. SYMTAB points to a symbol table.
+ //
+ // The method returns a status code at return. If the return status is
+ // CFLV_OK, *LV_OUT contains the final value. If the return status is
+ // CFLV_ERROR, *LV_OUT is 0. If the return status is CFLV_DISCARDED,
+ // *LV_OUT is not modified.
+ Compute_final_local_value_status
+ compute_final_local_value(unsigned int r_sym,
+ const Symbol_value<size>* lv_in,
+ Symbol_value<size>* lv_out,
+ const Symbol_table* symtab);
+
protected:
// Set up.
virtual void
do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*);
Archive::Should_include
- do_should_include_member(Symbol_table* symtab, Read_symbols_data*,
+ do_should_include_member(Symbol_table* symtab, Layout*, Read_symbols_data*,
std::string* why);
// Read the relocs.
// This may be overriden by a child class.
virtual void
do_relocate_sections(const Symbol_table* symtab, const Layout* layout,
- const unsigned char* pshdrs, Views* pviews);
+ const unsigned char* pshdrs, Output_file* of,
+ Views* pviews);
// Allow a child to set output local symbol count.
void
// Whether to include a section group in the link.
bool
include_section_group(Symbol_table*, Layout*, unsigned int, const char*,
- const unsigned char*, const char *, section_size_type,
+ const unsigned char*, const char*, section_size_type,
std::vector<bool>*);
// Whether to include a linkonce section in the link.
// Relocate the sections in the output file.
void
relocate_sections(const Symbol_table* symtab, const Layout* layout,
- const unsigned char* pshdrs, Views* pviews)
- { this->do_relocate_sections(symtab, layout, pshdrs, pviews); }
+ const unsigned char* pshdrs, Output_file* of,
+ Views* pviews)
+ { this->do_relocate_sections(symtab, layout, pshdrs, of, pviews); }
// Scan the input relocations for --emit-relocs.
void
unsigned char* reloc_view,
section_size_type reloc_view_size);
+ // Scan the input relocations for --incremental.
+ void
+ incremental_relocs_scan(const Read_relocs_data::Relocs_list::iterator&);
+
+ // Scan the input relocations for --incremental, templatized on the
+ // type of the relocation section.
+ template<int sh_type>
+ void
+ incremental_relocs_scan_reltype(
+ const Read_relocs_data::Relocs_list::iterator&);
+
+ void
+ incremental_relocs_write(const Relocate_info<size, big_endian>*,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section*,
+ Address output_offset,
+ Output_file*);
+
+ template<int sh_type>
+ void
+ incremental_relocs_write_reltype(const Relocate_info<size, big_endian>*,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section*,
+ Address output_offset,
+ Output_file*);
+
// A type shared by split_stack_adjust_reltype and find_functions.
typedef std::map<section_offset_type, section_size_type> Function_offsets;
Output_symtab_xindex*,
Output_symtab_xindex*);
- // Clear the local symbol information.
- void
- clear_local_symbols()
- {
- this->local_values_.clear();
- this->local_got_offsets_.clear();
- }
-
// Record a mapping from discarded section SHNDX to the corresponding
// kept section.
void
return true;
}
+ // Compute final local symbol value. R_SYM is the local symbol index.
+ // LV_IN points to a local symbol value containing the input value.
+ // LV_OUT points to a local symbol value storing the final output value,
+ // which must not be a merged symbol value since before calling this
+ // method to avoid memory leak. RELOCATABLE indicates whether we are
+ // linking a relocatable output. OUT_SECTIONS is an array of output
+ // sections. OUT_OFFSETS is an array of offsets of the sections. SYMTAB
+ // points to a symbol table.
+ //
+ // The method returns a status code at return. If the return status is
+ // CFLV_OK, *LV_OUT contains the final value. If the return status is
+ // CFLV_ERROR, *LV_OUT is 0. If the return status is CFLV_DISCARDED,
+ // *LV_OUT is not modified.
+ inline Compute_final_local_value_status
+ compute_final_local_value_internal(unsigned int r_sym,
+ const Symbol_value<size>* lv_in,
+ Symbol_value<size>* lv_out,
+ bool relocatable,
+ const Output_sections& out_sections,
+ const std::vector<Address>& out_offsets,
+ const Symbol_table* symtab);
+
// The GOT offsets of local symbols. This map also stores GOT offsets
// for tp-relative offsets for TLS symbols.
typedef Unordered_map<unsigned int, Got_offset_list*> Local_got_offsets;
- // The TLS GOT offsets of local symbols. The map stores the offsets
- // for either a single GOT entry that holds the module index of a TLS
- // symbol, or a pair of GOT entries containing the module index and
- // dtv-relative offset.
- struct Tls_got_entry
- {
- Tls_got_entry(int got_offset, bool have_pair)
- : got_offset_(got_offset),
- have_pair_(have_pair)
- { }
- int got_offset_;
- bool have_pair_;
- };
- typedef Unordered_map<unsigned int, Tls_got_entry> Local_tls_got_offsets;
+ // The PLT offsets of local symbols.
+ typedef Unordered_map<unsigned int, unsigned int> Local_plt_offsets;
// Saved information for sections whose layout was deferred.
struct Deferred_layout
// GOT offsets for local non-TLS symbols, and tp-relative offsets
// for TLS symbols, indexed by symbol number.
Local_got_offsets local_got_offsets_;
+ // PLT offsets for local symbols.
+ Local_plt_offsets local_plt_offsets_;
// For each input section, the offset of the input section in its
// output section. This is INVALID_ADDRESS if the input section requires a
// special mapping.
extern bool
is_elf_object(Input_file* input_file, off_t offset,
- const unsigned char** start, int *read_size);
+ const unsigned char** start, int* read_size);
// Return an Object appropriate for the input file. P is BYTES long,
// and holds the ELF header. If PUNCONFIGURED is not NULL, then if