// object.h -- support for an object file for linking in gold -*- C++ -*-
-// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
class General_options;
class Task;
+class Cref;
+class Archive;
class Layout;
class Output_section;
class Output_file;
+class Output_symtab_xindex;
+class Pluginobj;
class Dynobj;
class Object_merge_map;
class Relocatable_relocs;
+class Symbols_data;
template<typename Stringpool_char>
class Stringpool_template;
File_view* local_symbols;
};
+// The Xindex class manages section indexes for objects with more than
+// 0xff00 sections.
+
+class Xindex
+{
+ public:
+ Xindex(int large_shndx_offset)
+ : large_shndx_offset_(large_shndx_offset), symtab_xindex_()
+ { }
+
+ // Initialize the symtab_xindex_ array, given the object and the
+ // section index of the symbol table to use.
+ template<int size, bool big_endian>
+ void
+ initialize_symtab_xindex(Object*, unsigned int symtab_shndx);
+
+ // Read in the symtab_xindex_ array, given its section index.
+ // PSHDRS may optionally point to the section headers.
+ template<int size, bool big_endian>
+ void
+ read_symtab_xindex(Object*, unsigned int xindex_shndx,
+ const unsigned char* pshdrs);
+
+ // Symbol SYMNDX in OBJECT has a section of SHN_XINDEX; return the
+ // real section index.
+ unsigned int
+ sym_xindex_to_shndx(Object* object, unsigned int symndx);
+
+ private:
+ // The type of the array giving the real section index for symbols
+ // whose st_shndx field holds SHN_XINDEX.
+ typedef std::vector<unsigned int> Symtab_xindex;
+
+ // Adjust a section index if necessary. This should only be called
+ // for ordinary section indexes.
+ unsigned int
+ adjust_shndx(unsigned int shndx)
+ {
+ if (shndx >= elfcpp::SHN_LORESERVE)
+ shndx += this->large_shndx_offset_;
+ return shndx;
+ }
+
+ // Adjust to apply to large section indexes.
+ int large_shndx_offset_;
+ // The data from the SHT_SYMTAB_SHNDX section.
+ Symtab_xindex symtab_xindex_;
+};
+
// Object is an abstract base class which represents either a 32-bit
// or a 64-bit input object. This can be a regular object file
// (ET_REL) or a shared object (ET_DYN).
class Object
{
public:
+ typedef std::vector<Symbol*> Symbols;
+
// NAME is the name of the object as we would report it to the user
// (e.g., libfoo.a(bar.o) if this is in an archive. INPUT_FILE is
// used to read the file. OFFSET is the offset within the input
Object(const std::string& name, Input_file* input_file, bool is_dynamic,
off_t offset = 0)
: name_(name), input_file_(input_file), offset_(offset), shnum_(-1U),
- is_dynamic_(is_dynamic), target_(NULL)
+ is_dynamic_(is_dynamic), is_needed_(false), uses_split_stack_(false),
+ has_no_split_stack_(false), no_export_(false), xindex_(NULL)
{ input_file->file().add_object(); }
virtual ~Object()
is_dynamic() const
{ return this->is_dynamic_; }
- // Return the target structure associated with this object.
- Target*
- target() const
- { return this->target_; }
+ // Return whether this object is needed--true if it is a dynamic
+ // object which defines some symbol referenced by a regular object.
+ // We keep the flag here rather than in Dynobj for convenience when
+ // setting it.
+ bool
+ is_needed() const
+ { return this->is_needed_; }
+
+ // Record that this object is needed.
+ void
+ set_is_needed()
+ { this->is_needed_ = true; }
+
+ // Return whether this object was compiled with -fsplit-stack.
+ bool
+ uses_split_stack() const
+ { return this->uses_split_stack_; }
+
+ // Return whether this object contains any functions compiled with
+ // the no_split_stack attribute.
+ bool
+ has_no_split_stack() const
+ { return this->has_no_split_stack_; }
+
+ // Returns NULL for Objects that are not plugin objects. This method
+ // is overridden in the Pluginobj class.
+ Pluginobj*
+ pluginobj()
+ { return this->do_pluginobj(); }
+
+ // Get the file. We pass on const-ness.
+ Input_file*
+ input_file()
+ { return this->input_file_; }
+
+ const Input_file*
+ input_file() const
+ { return this->input_file_; }
// Lock the underlying file.
void
just_symbols() const
{ return this->input_file()->just_symbols(); }
- // Return the sized target structure associated with this object.
- // This is like the target method but it returns a pointer of
- // appropriate checked type.
- template<int size, bool big_endian>
- Sized_target<size, big_endian>*
- sized_target() const;
-
// Get the number of sections.
unsigned int
shnum() const
const unsigned char*
section_contents(unsigned int shndx, section_size_type* plen, bool cache);
+ // Adjust a symbol's section index as needed. SYMNDX is the index
+ // of the symbol and SHNDX is the symbol's section from
+ // get_st_shndx. This returns the section index. It sets
+ // *IS_ORDINARY to indicate whether this is a normal section index,
+ // rather than a special code between SHN_LORESERVE and
+ // SHN_HIRESERVE.
+ unsigned int
+ adjust_sym_shndx(unsigned int symndx, unsigned int shndx, bool* is_ordinary)
+ {
+ if (shndx < elfcpp::SHN_LORESERVE)
+ *is_ordinary = true;
+ else if (shndx == elfcpp::SHN_XINDEX)
+ {
+ if (this->xindex_ == NULL)
+ this->xindex_ = this->do_initialize_xindex();
+ shndx = this->xindex_->sym_xindex_to_shndx(this, symndx);
+ *is_ordinary = true;
+ }
+ else
+ *is_ordinary = false;
+ return shndx;
+ }
+
// Return the size of a section given a section index.
uint64_t
section_size(unsigned int shndx)
section_flags(unsigned int shndx)
{ return this->do_section_flags(shndx); }
+ // Return the section entsize given a section index.
+ uint64_t
+ section_entsize(unsigned int shndx)
+ { return this->do_section_entsize(shndx); }
+
// Return the section address given a section index.
uint64_t
section_address(unsigned int shndx)
// Add symbol information to the global symbol table.
void
- add_symbols(Symbol_table* symtab, Read_symbols_data* sd)
- { this->do_add_symbols(symtab, sd); }
+ add_symbols(Symbol_table* symtab, Read_symbols_data* sd, Layout *layout)
+ { this->do_add_symbols(symtab, sd, layout); }
// Functions and types for the elfcpp::Elf_file interface. This
// permit us to use Object as the File template parameter for
// Return a View.
View
view(off_t file_offset, section_size_type data_size)
- { return View(this->get_view(file_offset, data_size, true)); }
+ { return View(this->get_view(file_offset, data_size, true, true)); }
// Report an error.
void
// Get a View given a Location.
View view(Location loc)
- { return View(this->get_view(loc.file_offset, loc.data_size, true)); }
+ { return View(this->get_view(loc.file_offset, loc.data_size, true, true)); }
// Get a view into the underlying file.
const unsigned char*
- get_view(off_t start, section_size_type size, bool cache)
+ get_view(off_t start, section_size_type size, bool aligned, bool cache)
{
- return this->input_file()->file().get_view(start + this->offset_, size,
- cache);
+ return this->input_file()->file().get_view(this->offset_, start, size,
+ aligned, cache);
}
// Get a lasting view into the underlying file.
File_view*
- get_lasting_view(off_t start, section_size_type size, bool cache)
+ get_lasting_view(off_t start, section_size_type size, bool aligned,
+ bool cache)
{
- return this->input_file()->file().get_lasting_view(start + this->offset_,
- size, cache);
+ return this->input_file()->file().get_lasting_view(this->offset_, start,
+ size, aligned, cache);
}
// Read data from the underlying file.
void
- read(off_t start, section_size_type size, void* p) const
+ read(off_t start, section_size_type size, void* p)
{ this->input_file()->file().read(start + this->offset_, size, p); }
// Read multiple data from the underlying file.
clear_view_cache_marks()
{ this->input_file()->file().clear_view_cache_marks(); }
+ // Get the number of global symbols defined by this object, and the
+ // number of the symbols whose final definition came from this
+ // object.
+ void
+ get_global_symbol_counts(const Symbol_table* symtab, size_t* defined,
+ size_t* used) const
+ { this->do_get_global_symbol_counts(symtab, defined, used); }
+
+ // Get the symbols defined in this object.
+ const Symbols*
+ get_global_symbols() const
+ { return this->do_get_global_symbols(); }
+
+ // Return whether this object was found in a system directory.
+ bool
+ is_in_system_directory() const
+ { return this->input_file()->is_in_system_directory(); }
+
+ // Return whether we found this object by searching a directory.
+ bool
+ searched_for() const
+ { return this->input_file()->will_search_for(); }
+
+ bool
+ no_export() const
+ { return this->no_export_; }
+
+ void
+ set_no_export(bool value)
+ { this->no_export_ = value; }
+
protected:
+ // Returns NULL for Objects that are not plugin objects. This method
+ // is overridden in the Pluginobj class.
+ virtual Pluginobj*
+ do_pluginobj()
+ { return NULL; }
+
// Read the symbols--implemented by child class.
virtual void
do_read_symbols(Read_symbols_data*) = 0;
// Add symbol information to the global symbol table--implemented by
// child class.
virtual void
- do_add_symbols(Symbol_table*, Read_symbols_data*) = 0;
+ do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*) = 0;
// Return the location of the contents of a section. Implemented by
// child class.
virtual uint64_t
do_section_flags(unsigned int shndx) = 0;
+ // Get section entsize--implemented by child class.
+ virtual uint64_t
+ do_section_entsize(unsigned int shndx) = 0;
+
// Get section address--implemented by child class.
virtual uint64_t
do_section_address(unsigned int shndx) = 0;
virtual uint64_t
do_section_addralign(unsigned int shndx) = 0;
- // Get the file. We pass on const-ness.
- Input_file*
- input_file()
- { return this->input_file_; }
+ // Return the Xindex structure to use.
+ virtual Xindex*
+ do_initialize_xindex() = 0;
- const Input_file*
- input_file() const
- { return this->input_file_; }
+ // Implement get_global_symbol_counts--implemented by child class.
+ virtual void
+ do_get_global_symbol_counts(const Symbol_table*, size_t*, size_t*) const = 0;
- // Set the target.
- void
- set_target(int machine, int size, bool big_endian, int osabi,
- int abiversion);
+ virtual const Symbols*
+ do_get_global_symbols() const = 0;
// Set the number of sections.
void
read_section_data(elfcpp::Elf_file<size, big_endian, Object>*,
Read_symbols_data*);
+ // Let the child class initialize the xindex object directly.
+ void
+ set_xindex(Xindex* xindex)
+ {
+ gold_assert(this->xindex_ == NULL);
+ this->xindex_ = xindex;
+ }
+
// If NAME is the name of a special .gnu.warning section, arrange
// for the warning to be issued. SHNDX is the section index.
// Return whether it is a warning section.
handle_gnu_warning_section(const char* name, unsigned int shndx,
Symbol_table*);
+ // If NAME is the name of the special section which indicates that
+ // this object was compiled with -fstack-split, mark it accordingly,
+ // and return true. Otherwise return false.
+ bool
+ handle_split_stack_section(const char* name);
+
private:
// This class may not be copied.
Object(const Object&);
// Number of input sections.
unsigned int shnum_;
// Whether this is a dynamic object.
- bool is_dynamic_;
- // Target functions--may be NULL if the target is not known.
- Target* target_;
+ bool is_dynamic_ : 1;
+ // Whether this object is needed. This is only set for dynamic
+ // objects, and means that the object defined a symbol which was
+ // used by a reference from a regular object.
+ bool is_needed_ : 1;
+ // Whether this object was compiled with -fsplit-stack.
+ bool uses_split_stack_ : 1;
+ // Whether this object contains any functions compiled with the
+ // no_split_stack attribute.
+ bool has_no_split_stack_ : 1;
+ // True if exclude this object from automatic symbol export.
+ // This is used only for archive objects.
+ bool no_export_ : 1;
+ // Many sections for objects with more than SHN_LORESERVE sections.
+ Xindex* xindex_;
};
-// Implement sized_target inline for efficiency. This approach breaks
-// static type checking, but is made safe using asserts.
-
-template<int size, bool big_endian>
-inline Sized_target<size, big_endian>*
-Object::sized_target() const
-{
- gold_assert(this->target_->get_size() == size);
- gold_assert(this->target_->is_big_endian() ? big_endian : !big_endian);
- return static_cast<Sized_target<size, big_endian>*>(this->target_);
-}
-
// A regular object (ET_REL). This is an abstract base class itself.
// The implementation is the template class Sized_relobj.
public:
Relobj(const std::string& name, Input_file* input_file, off_t offset = 0)
: Object(name, input_file, false, offset),
- map_to_output_(),
+ output_sections_(),
map_to_relocatable_relocs_(NULL),
object_merge_map_(NULL),
- relocs_must_follow_section_writes_(false)
+ relocs_must_follow_section_writes_(false),
+ sd_(NULL)
{ }
+ // During garbage collection, the Read_symbols_data pass for
+ // each object is stored as layout needs to be done after
+ // reloc processing.
+ Symbols_data*
+ get_symbols_data()
+ { return this->sd_; }
+
+ // Decides which section names have to be included in the worklist
+ // as roots.
+ bool
+ is_section_name_included(const char *name);
+
+ void
+ copy_symbols_data(Symbols_data* gc_sd, Read_symbols_data* sd,
+ unsigned int section_header_size);
+
+ void
+ set_symbols_data(Symbols_data* sd)
+ { this->sd_ = sd; }
+
+ // During garbage collection, the Read_relocs pass for all objects
+ // is done before scanning the relocs. In that case, this->rd_ is
+ // used to store the information from Read_relocs for each object.
+ // This data is also used to compute the list of relevant sections.
+ Read_relocs_data*
+ get_relocs_data()
+ { return this->rd_; }
+
+ void
+ set_relocs_data(Read_relocs_data* rd)
+ { this->rd_ = rd; }
+
+ virtual bool
+ is_output_section_offset_invalid(unsigned int shndx) const = 0;
+
// Read the relocs.
void
read_relocs(Read_relocs_data* rd)
{ return this->do_read_relocs(rd); }
+ // Process the relocs, during garbage collection only.
+ void
+ gc_process_relocs(Symbol_table* symtab, Layout* layout, Read_relocs_data* rd)
+ { return this->do_gc_process_relocs(symtab, layout, rd); }
+
// Scan the relocs and adjust the symbol table.
void
- scan_relocs(const General_options& options, Symbol_table* symtab,
- Layout* layout, Read_relocs_data* rd)
- { return this->do_scan_relocs(options, symtab, layout, rd); }
+ scan_relocs(Symbol_table* symtab, Layout* layout, Read_relocs_data* rd)
+ { return this->do_scan_relocs(symtab, layout, rd); }
// The number of local symbols in the input symbol table.
virtual unsigned int
// indexes for the local variables, and set the offset where local
// symbol information will be stored. Returns the new local symbol index.
unsigned int
- finalize_local_symbols(unsigned int index, off_t off)
- { return this->do_finalize_local_symbols(index, off); }
+ finalize_local_symbols(unsigned int index, off_t off, Symbol_table* symtab)
+ { return this->do_finalize_local_symbols(index, off, symtab); }
// Set the output dynamic symbol table indexes for the local variables.
unsigned int
// Relocate the input sections and write out the local symbols.
void
- relocate(const General_options& options, const Symbol_table* symtab,
- const Layout* layout, Output_file* of)
- { return this->do_relocate(options, symtab, layout, of); }
+ relocate(const Symbol_table* symtab, const Layout* layout, Output_file* of)
+ { return this->do_relocate(symtab, layout, of); }
// Return whether an input section is being included in the link.
bool
is_section_included(unsigned int shndx) const
{
- gold_assert(shndx < this->map_to_output_.size());
- return this->map_to_output_[shndx].output_section != NULL;
+ gold_assert(shndx < this->output_sections_.size());
+ return this->output_sections_[shndx] != NULL;
}
- // Return whether an input section requires special
- // handling--whether it is not simply mapped from the input file to
- // the output file.
- bool
- is_section_specially_mapped(unsigned int shndx) const
+ // 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->map_to_output_.size());
- return (this->map_to_output_[shndx].output_section != NULL
- && this->map_to_output_[shndx].offset == -1);
+ gold_assert(shndx < this->output_sections_.size());
+ return this->output_sections_[shndx];
}
- // Given a section index, return the corresponding Output_section
- // (which will be NULL if the section is not included in the link)
- // and set *POFF to the offset within that section. *POFF will be
- // set to -1 if the section requires special handling.
- inline Output_section*
- output_section(unsigned int shndx, section_offset_type* poff) const;
-
- // Set the offset of an input section within its output section.
+ // 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.
void
- set_section_offset(unsigned int shndx, section_offset_type off)
+ set_output_section(unsigned int shndx, Output_section* os)
{
- gold_assert(shndx < this->map_to_output_.size());
- this->map_to_output_[shndx].offset = off;
+ gold_assert(shndx < this->output_sections_.size());
+ 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)
+ { this->do_set_section_offset(shndx, off); }
// Return true if we need to wait for output sections to be written
// before we can apply relocations. This is true if the object has
return (*this->map_to_relocatable_relocs_)[reloc_shndx];
}
+ // Layout sections whose layout was deferred while waiting for
+ // input files from a plugin.
+ void
+ layout_deferred_sections(Layout* layout)
+ { this->do_layout_deferred_sections(layout); }
+
protected:
- // What we need to know to map an input section to an output
- // section. We keep an array of these, one for each input section,
- // indexed by the input section number.
- struct Map_to_output
- {
- // The output section. This is NULL if the input section is to be
- // discarded.
- Output_section* output_section;
- // The offset within the output section. This is -1 if the
- // section requires special handling.
- section_offset_type offset;
- };
+ // The output section to be used for each input section, indexed by
+ // the input section number. The output section is NULL if the
+ // input section is to be discarded.
+ typedef std::vector<Output_section*> Output_sections;
// Read the relocs--implemented by child class.
virtual void
do_read_relocs(Read_relocs_data*) = 0;
+ // Process the relocs--implemented by child class.
+ virtual void
+ do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*) = 0;
+
// Scan the relocs--implemented by child class.
virtual void
- do_scan_relocs(const General_options&, Symbol_table*, Layout*,
- Read_relocs_data*) = 0;
+ do_scan_relocs(Symbol_table*, Layout*, Read_relocs_data*) = 0;
// Return the number of local symbols--implemented by child class.
virtual unsigned int
// for the local variables, and set the offset where local symbol
// information will be stored.
virtual unsigned int
- do_finalize_local_symbols(unsigned int, off_t) = 0;
+ do_finalize_local_symbols(unsigned int, off_t, Symbol_table*) = 0;
// Set the output dynamic symbol table indexes for the local variables.
virtual unsigned int
// Relocate the input sections and write out the local
// symbols--implemented by child class.
virtual void
- do_relocate(const General_options& options, const Symbol_table* symtab,
- const Layout*, Output_file* of) = 0;
+ 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;
+
+ // Layout sections whose layout was deferred while waiting for
+ // input files from a plugin--implemented by child class.
+ virtual void
+ do_layout_deferred_sections(Layout*) = 0;
// Return the vector mapping input sections to output sections.
- std::vector<Map_to_output>&
- map_to_output()
- { return this->map_to_output_; }
+ Output_sections&
+ output_sections()
+ { return this->output_sections_; }
- const std::vector<Map_to_output>&
- map_to_output() const
- { return this->map_to_output_; }
+ const Output_sections&
+ output_sections() const
+ { return this->output_sections_; }
// Set the size of the relocatable relocs array.
void
private:
// Mapping from input sections to output section.
- std::vector<Map_to_output> map_to_output_;
+ Output_sections output_sections_;
// Mapping from input section index to the information recorded for
// the relocations. This is only used for a relocatable link.
std::vector<Relocatable_relocs*>* map_to_relocatable_relocs_;
// Whether we need to wait for output sections to be written before
// we can apply relocations.
bool relocs_must_follow_section_writes_;
+ // Used to store the relocs data computed by the Read_relocs pass.
+ // Used during garbage collection of unused sections.
+ Read_relocs_data* rd_;
+ // 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_;
};
-// Implement Object::output_section inline for efficiency.
-inline Output_section*
-Relobj::output_section(unsigned int shndx, section_offset_type* poff) const
-{
- gold_assert(shndx < this->map_to_output_.size());
- const Map_to_output& mo(this->map_to_output_[shndx]);
- *poff = mo.offset;
- return mo.output_section;
-}
-
// This class is used to handle relocations against a section symbol
// in an SHF_MERGE section. For such a symbol, we need to know the
// addend of the relocation before we can determine the final value.
Value
value(const Relobj* object, unsigned int input_shndx, Value addend) const
{
- Value input_offset = this->input_value_ + addend;
+ // This is a relocation against a section symbol. ADDEND is the
+ // offset in the section. The result should be the start of some
+ // merge area. If the object file wants something else, it should
+ // use a regular symbol rather than a section symbol.
+ // Unfortunately, PR 6658 shows a case in which the object file
+ // refers to the section symbol, but uses a negative ADDEND to
+ // compensate for a PC relative reloc. We can't handle the
+ // general case. However, we can handle the special case of a
+ // negative addend, by assuming that it refers to the start of the
+ // section. Of course, that means that we have to guess when
+ // ADDEND is negative. It is normal to see a 32-bit value here
+ // even when the template parameter size is 64, as 64-bit object
+ // file formats have 32-bit relocations. We know this is a merge
+ // section, so we know it has to fit into memory. So we assume
+ // that we won't see a value larger than a large 32-bit unsigned
+ // value. This will break objects with very very large merge
+ // sections; they probably break in other ways anyhow.
+ Value input_offset = this->input_value_;
+ if (addend < 0xffffff00)
+ {
+ input_offset += addend;
+ addend = 0;
+ }
typename Output_addresses::const_iterator p =
this->output_addresses_.find(input_offset);
if (p != this->output_addresses_.end())
- return p->second;
+ return p->second + addend;
- return this->value_from_output_section(object, input_shndx, input_offset);
+ return (this->value_from_output_section(object, input_shndx, input_offset)
+ + addend);
}
private:
Symbol_value()
: output_symtab_index_(0), output_dynsym_index_(-1U), input_shndx_(0),
- is_section_symbol_(false), is_tls_symbol_(false),
- has_output_value_(true)
+ is_ordinary_shndx_(false), is_section_symbol_(false),
+ is_tls_symbol_(false), has_output_value_(true)
{ this->u_.value = 0; }
// Get the value of this symbol. OBJECT is the object in which this
if (this->has_output_value_)
return this->u_.value + addend;
else
- return this->u_.merged_symbol_value->value(object, this->input_shndx_,
- addend);
+ {
+ gold_assert(this->is_ordinary_shndx_);
+ return this->u_.merged_symbol_value->value(object, this->input_shndx_,
+ addend);
+ }
}
// Set the value of this symbol in the output symbol table.
{
if (!this->has_output_value_)
{
- gold_assert(this->is_section_symbol_);
+ gold_assert(this->is_section_symbol_ && this->is_ordinary_shndx_);
Merged_symbol_value<size>* msv = this->u_.merged_symbol_value;
msv->initialize_input_to_output_map(object, this->input_shndx_);
}
{ this->u_.value = value; }
// Return the input value. This is only called by
- // finalize_local_symbols.
+ // finalize_local_symbols and (in special cases) relocate_section.
Value
input_value() const
{ return this->u_.value; }
// Set the index of the input section in the input file.
void
- set_input_shndx(unsigned int i)
+ set_input_shndx(unsigned int i, bool is_ordinary)
{
this->input_shndx_ = i;
// input_shndx_ field is a bitfield, so make sure that the value
// fits.
gold_assert(this->input_shndx_ == i);
+ this->is_ordinary_shndx_ = is_ordinary;
}
// Return the index of the input section in the input file.
unsigned int
- input_shndx() const
- { return this->input_shndx_; }
+ input_shndx(bool* is_ordinary) const
+ {
+ *is_ordinary = this->is_ordinary_shndx_;
+ return this->input_shndx_;
+ }
// Whether this is a section symbol.
bool
unsigned int output_dynsym_index_;
// The section index in the input file in which this symbol is
// defined.
- unsigned int input_shndx_ : 29;
+ unsigned int input_shndx_ : 28;
+ // Whether the section index is an ordinary index, not a special
+ // value.
+ bool is_ordinary_shndx_ : 1;
// Whether this is a STT_SECTION symbol.
bool is_section_symbol_ : 1;
// Whether this is a STT_TLS symbol.
Got_offset_list* got_next_;
};
+// This type is used to modify relocations for -fsplit-stack. It is
+// indexed by relocation index, and means that the relocation at that
+// index should use the symbol from the vector, rather than the one
+// indicated by the relocation.
+
+class Reloc_symbol_changes
+{
+ public:
+ Reloc_symbol_changes(size_t count)
+ : vec_(count, NULL)
+ { }
+
+ void
+ set(size_t i, Symbol* sym)
+ { this->vec_[i] = sym; }
+
+ const Symbol*
+ operator[](size_t i) const
+ { return this->vec_[i]; }
+
+ private:
+ std::vector<Symbol*> vec_;
+};
+
// A regular object file. This is size and endian specific.
template<int size, bool big_endian>
typedef std::vector<Symbol*> Symbols;
typedef std::vector<Symbol_value<size> > Local_values;
+ static const Address invalid_address = static_cast<Address>(0) - 1;
+
Sized_relobj(const std::string& name, Input_file* input_file, off_t offset,
const typename elfcpp::Ehdr<size, big_endian>&);
~Sized_relobj();
- // Set up the object file based on the ELF header.
+ // Checks if the offset of input section SHNDX within its output
+ // section is invalid.
+ bool
+ is_output_section_offset_invalid(unsigned int shndx) const
+ { return this->get_output_section_offset(shndx) == invalid_address; }
+
+ // Set up the object file based on TARGET.
void
- setup(const typename elfcpp::Ehdr<size, big_endian>&);
+ setup()
+ { this->do_setup(); }
+
+ // Return the number of symbols. This is only valid after
+ // Object::add_symbols has been called.
+ unsigned int
+ symbol_count() const
+ { return this->local_symbol_count_ + this->symbols_.size(); }
// If SYM is the index of a global symbol in the object file's
// symbol table, return the Symbol object. Otherwise, return NULL.
}
// Return the section index of symbol SYM. Set *VALUE to its value
- // in the object file. Note that for a symbol which is not defined
- // in this object file, this will set *VALUE to 0 and return
- // SHN_UNDEF; it will not return the final value of the symbol in
- // the link.
+ // in the object file. Set *IS_ORDINARY if this is an ordinary
+ // section index, not a special code between SHN_LORESERVE and
+ // SHN_HIRESERVE. Note that for a symbol which is not defined in
+ // this object file, this will set *VALUE to 0 and return SHN_UNDEF;
+ // it will not return the final value of the symbol in the link.
unsigned int
- symbol_section_and_value(unsigned int sym, Address* value);
+ symbol_section_and_value(unsigned int sym, Address* value, bool* is_ordinary);
// Return a pointer to the Symbol_value structure which holds the
// value of a local symbol.
// Return the input section index of local symbol SYM.
unsigned int
- local_symbol_input_shndx(unsigned int sym) const
+ local_symbol_input_shndx(unsigned int sym, bool* is_ordinary) const
{
gold_assert(sym < this->local_values_.size());
- return this->local_values_[sym].input_shndx();
+ return this->local_values_[sym].input_shndx(is_ordinary);
}
- // Return the appropriate Sized_target structure.
- Sized_target<size, big_endian>*
- sized_target()
- { return this->Object::sized_target<size, big_endian>(); }
-
// Record that local symbol SYM needs a dynamic symbol entry.
void
set_needs_output_dynsym_entry(unsigned int sym)
}
}
+ // 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
+ // output_sections_ field of the parent class Relobj.
+ Address
+ get_output_section_offset(unsigned int shndx) const
+ {
+ gold_assert(shndx < this->section_offsets_.size());
+ return this->section_offsets_[shndx];
+ }
+
// Return the name of the symbol that spans the given offset in the
// specified section in this object. This is used only for error
// messages and is not particularly efficient.
get_symbol_location_info(unsigned int shndx, off_t offset,
Symbol_location_info* info);
+ // Look for a kept section corresponding to the given discarded section,
+ // and return its output address. This is used only for relocations in
+ // debugging sections.
+ Address
+ map_to_kept_section(unsigned int shndx, bool* found) const;
+
protected:
+ // Set up.
+ virtual void
+ do_setup();
+
// Read the symbols.
void
do_read_symbols(Read_symbols_data*);
void
do_layout(Symbol_table*, Layout*, Read_symbols_data*);
+ // Layout sections whose layout was deferred while waiting for
+ // input files from a plugin.
+ void
+ do_layout_deferred_sections(Layout*);
+
// Add the symbols to the symbol table.
void
- do_add_symbols(Symbol_table*, Read_symbols_data*);
+ do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*);
// Read the relocs.
void
do_read_relocs(Read_relocs_data*);
+ // Process the relocs to find list of referenced sections. Used only
+ // during garbage collection.
+ void
+ do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
+
// Scan the relocs and adjust the symbol table.
void
- do_scan_relocs(const General_options&, Symbol_table*, Layout*,
- Read_relocs_data*);
+ do_scan_relocs(Symbol_table*, Layout*, Read_relocs_data*);
// Count the local symbols.
void
// Finalize the local symbols.
unsigned int
- do_finalize_local_symbols(unsigned int, off_t);
+ do_finalize_local_symbols(unsigned int, off_t, Symbol_table*);
// Set the offset where local dynamic symbol information will be stored.
unsigned int
// Relocate the input sections and write out the local symbols.
void
- do_relocate(const General_options& options, const Symbol_table* symtab,
- const Layout*, Output_file* of);
+ do_relocate(const Symbol_table* symtab, const Layout*, Output_file* of);
// Get the size of a section.
uint64_t
// Return section flags.
uint64_t
- do_section_flags(unsigned int shndx)
- { return this->elf_file_.section_flags(shndx); }
+ do_section_flags(unsigned int shndx);
+
+ // Return section entsize.
+ uint64_t
+ do_section_entsize(unsigned int shndx);
// Return section address.
uint64_t
do_section_addralign(unsigned int shndx)
{ return this->elf_file_.section_addralign(shndx); }
+ // Return the Xindex structure to use.
+ Xindex*
+ do_initialize_xindex();
+
+ // Get symbol counts.
+ void
+ do_get_global_symbol_counts(const Symbol_table*, size_t*, size_t*) const;
+
+ // Get the global symbols.
+ const Symbols*
+ do_get_global_symbols() const
+ { return &this->symbols_; }
+
+ // Get the offset of a section.
+ uint64_t
+ do_output_section_offset(unsigned int shndx) const
+ {
+ Address off = this->get_output_section_offset(shndx);
+ if (off == invalid_address)
+ return -1ULL;
+ return off;
+ }
+
+ // Set the offset of a section.
+ void
+ do_set_section_offset(unsigned int shndx, uint64_t off)
+ {
+ gold_assert(shndx < this->section_offsets_.size());
+ this->section_offsets_[shndx] =
+ (off == static_cast<uint64_t>(-1)
+ ? invalid_address
+ : convert_types<Address, uint64_t>(off));
+ }
+
+ // Adjust a section index if necessary.
+ unsigned int
+ adjust_shndx(unsigned int shndx)
+ {
+ if (shndx >= elfcpp::SHN_LORESERVE)
+ shndx += this->elf_file_.large_shndx_offset();
+ return shndx;
+ }
+
+ // Initialize input to output maps for section symbols in merged
+ // sections.
+ void
+ initialize_input_to_output_maps();
+
+ // Free the input to output maps for section symbols in merged
+ // sections.
+ void
+ free_input_to_output_maps();
+
+ // Return symbol table section index.
+ unsigned int
+ symtab_shndx() const
+ { return this->symtab_shndx_; }
+
+ // Allow a child class to access the ELF file.
+ elfcpp::Elf_file<size, big_endian, Object>*
+ elf_file()
+ { return &this->elf_file_; }
+
+ // Allow a child class to access the local values.
+ Local_values*
+ local_values()
+ { return &this->local_values_; }
+
+ // Views and sizes when relocating.
+ struct View_size
+ {
+ unsigned char* view;
+ typename elfcpp::Elf_types<size>::Elf_Addr address;
+ off_t offset;
+ section_size_type view_size;
+ bool is_input_output_view;
+ bool is_postprocessing_view;
+ };
+
+ typedef std::vector<View_size> Views;
+
+ // 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);
+
+ // Allow a child to set output local symbol count.
+ void
+ set_output_local_symbol_count(unsigned int value)
+ { this->output_local_symbol_count_ = value; }
+
private:
// For convenience.
typedef Sized_relobj<size, big_endian> This;
static const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
typedef elfcpp::Shdr<size, big_endian> Shdr;
+ // To keep track of discarded comdat sections, we need to map a member
+ // section index to the object and section index of the corresponding
+ // kept section.
+ struct Kept_comdat_section
+ {
+ Kept_comdat_section(Relobj* a_object, unsigned int a_shndx)
+ : object(a_object), shndx(a_shndx)
+ { }
+ Relobj* object;
+ unsigned int shndx;
+ };
+ typedef std::map<unsigned int, Kept_comdat_section>
+ Kept_comdat_section_table;
+
// Find the SHT_SYMTAB section, given the section headers.
void
find_symtab(const unsigned char* pshdrs);
// Whether to include a section group in the link.
bool
include_section_group(Symbol_table*, Layout*, unsigned int, const char*,
- const elfcpp::Shdr<size, big_endian>&,
+ const unsigned char*, const char *, section_size_type,
std::vector<bool>*);
// Whether to include a linkonce section in the link.
bool
- include_linkonce_section(Layout*, const char*,
+ include_linkonce_section(Layout*, unsigned int, const char*,
const elfcpp::Shdr<size, big_endian>&);
- // Views and sizes when relocating.
- struct View_size
- {
- unsigned char* view;
- typename elfcpp::Elf_types<size>::Elf_Addr address;
- off_t offset;
- section_size_type view_size;
- bool is_input_output_view;
- bool is_postprocessing_view;
- };
-
- typedef std::vector<View_size> Views;
+ // Layout an input section.
+ void
+ layout_section(Layout* layout, unsigned int shndx, const char* name,
+ typename This::Shdr& shdr, unsigned int reloc_shndx,
+ unsigned int reloc_type);
// Write section data to the output file. Record the views and
// sizes in VIEWS for use when relocating.
// Relocate the sections in the output file.
void
- relocate_sections(const General_options& options, const Symbol_table*,
- const Layout*, const unsigned char* pshdrs, Views*);
+ relocate_sections(const Symbol_table* symtab, const Layout* layout,
+ const unsigned char* pshdrs, Views* pviews)
+ { this->do_relocate_sections(symtab, layout, pshdrs, pviews); }
// Scan the input relocations for --emit-relocs.
void
- emit_relocs_scan(const General_options&, Symbol_table*, Layout*,
- const unsigned char* plocal_syms,
+ emit_relocs_scan(Symbol_table*, Layout*, const unsigned char* plocal_syms,
const Read_relocs_data::Relocs_list::iterator&);
// Scan the input relocations for --emit-relocs, templatized on the
// type of the relocation section.
template<int sh_type>
void
- emit_relocs_scan_reltype(const General_options&, Symbol_table*, Layout*,
+ emit_relocs_scan_reltype(Symbol_table*, Layout*,
const unsigned char* plocal_syms,
const Read_relocs_data::Relocs_list::iterator&,
Relocatable_relocs*);
void
emit_relocs(const Relocate_info<size, big_endian>*, unsigned int,
unsigned int sh_type, const unsigned char* prelocs,
- size_t reloc_count, Output_section*, off_t output_offset,
+ size_t reloc_count, Output_section*, Address output_offset,
unsigned char* view, Address address,
section_size_type view_size,
unsigned char* reloc_view, section_size_type reloc_view_size);
void
emit_relocs_reltype(const Relocate_info<size, big_endian>*, unsigned int,
const unsigned char* prelocs, size_t reloc_count,
- Output_section*, off_t output_offset,
+ Output_section*, Address output_offset,
unsigned char* view, Address address,
section_size_type view_size,
unsigned char* reloc_view,
section_size_type reloc_view_size);
- // Initialize input to output maps for section symbols in merged
- // sections.
+ // A type shared by split_stack_adjust_reltype and find_functions.
+ typedef std::map<section_offset_type, section_size_type> Function_offsets;
+
+ // Check for -fsplit-stack routines calling non-split-stack routines.
void
- initialize_input_to_output_maps();
+ split_stack_adjust(const Symbol_table*, const unsigned char* pshdrs,
+ unsigned int sh_type, unsigned int shndx,
+ const unsigned char* prelocs, size_t reloc_count,
+ unsigned char* view, section_size_type view_size,
+ Reloc_symbol_changes** reloc_map);
- // Free the input to output maps for section symbols in merged
- // sections.
+ template<int sh_type>
void
- free_input_to_output_maps();
+ split_stack_adjust_reltype(const Symbol_table*, const unsigned char* pshdrs,
+ unsigned int shndx, const unsigned char* prelocs,
+ size_t reloc_count, unsigned char* view,
+ section_size_type view_size,
+ Reloc_symbol_changes** reloc_map);
+
+ // Find all functions in a section.
+ void
+ find_functions(const unsigned char* pshdrs, unsigned int shndx,
+ Function_offsets*);
// Write out the local symbols.
void
write_local_symbols(Output_file*,
const Stringpool_template<char>*,
- const Stringpool_template<char>*);
+ const Stringpool_template<char>*,
+ Output_symtab_xindex*,
+ Output_symtab_xindex*);
// Clear the local symbol information.
void
this->local_got_offsets_.clear();
}
+ // Record a mapping from discarded section SHNDX to the corresponding
+ // kept section.
+ void
+ set_kept_comdat_section(unsigned int shndx, Relobj* kept_object,
+ unsigned int kept_shndx)
+ {
+ Kept_comdat_section kept(kept_object, kept_shndx);
+ this->kept_comdat_sections_.insert(std::make_pair(shndx, kept));
+ }
+
+ // Find the kept section corresponding to the discarded section
+ // SHNDX. Return true if found.
+ bool
+ get_kept_comdat_section(unsigned int shndx, Relobj** kept_object,
+ unsigned int* kept_shndx) const
+ {
+ typename Kept_comdat_section_table::const_iterator p =
+ this->kept_comdat_sections_.find(shndx);
+ if (p == this->kept_comdat_sections_.end())
+ return false;
+ *kept_object = p->second.object;
+ *kept_shndx = p->second.shndx;
+ return true;
+ }
+
// 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;
};
typedef Unordered_map<unsigned int, Tls_got_entry> Local_tls_got_offsets;
+ // Saved information for sections whose layout was deferred.
+ struct Deferred_layout
+ {
+ static const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
+ Deferred_layout(unsigned int shndx, const char* name,
+ const unsigned char* pshdr,
+ unsigned int reloc_shndx, unsigned int reloc_type)
+ : shndx_(shndx), name_(name), reloc_shndx_(reloc_shndx),
+ reloc_type_(reloc_type)
+ {
+ memcpy(this->shdr_data_, pshdr, shdr_size);
+ }
+ unsigned int shndx_;
+ std::string name_;
+ unsigned int reloc_shndx_;
+ unsigned int reloc_type_;
+ unsigned char shdr_data_[shdr_size];
+ };
+
// General access to the ELF file.
elfcpp::Elf_file<size, big_endian, Object> elf_file_;
// Index of SHT_SYMTAB section.
unsigned int output_local_dynsym_count_;
// The entries in the symbol table for the external symbols.
Symbols symbols_;
+ // Number of symbols defined in object file itself.
+ size_t defined_count_;
// File offset for local symbols.
off_t local_symbol_offset_;
// File offset for local dynamic symbols.
// GOT offsets for local non-TLS symbols, and tp-relative offsets
// for TLS symbols, indexed by symbol number.
Local_got_offsets local_got_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.
+ std::vector<Address> section_offsets_;
+ // Table mapping discarded comdat sections to corresponding kept sections.
+ Kept_comdat_section_table kept_comdat_sections_;
// Whether this object has a GNU style .eh_frame section.
bool has_eh_frame_;
+ // If this object has a GNU style .eh_frame section that is discarded in
+ // output, record the index here. Otherwise it is -1U.
+ unsigned int discarded_eh_frame_shndx_;
+ // The list of sections whose layout was deferred.
+ std::vector<Deferred_layout> deferred_layout_;
};
// A class to manage the list of all objects.
{
public:
Input_objects()
- : relobj_list_(), dynobj_list_(), sonames_(), system_library_directory_()
+ : relobj_list_(), dynobj_list_(), sonames_(), cref_(NULL)
{ }
// The type of the list of input relocateable objects.
bool
add_object(Object*);
+ // Start processing an archive.
+ void
+ archive_start(Archive*);
+
+ // Stop processing an archive.
+ void
+ archive_stop(Archive*);
+
// For each dynamic object, check whether we've seen all of its
// explicit dependencies.
void
bool
found_in_system_library_directory(const Object*) const;
+ // Print symbol counts.
+ void
+ print_symbol_counts(const Symbol_table*) const;
+
+ // Print a cross reference table.
+ void
+ print_cref(const Symbol_table*, FILE*) const;
+
// Iterate over all regular objects.
Relobj_iterator
Dynobj_list dynobj_list_;
// SONAMEs that we have seen.
Unordered_set<std::string> sonames_;
- // The directory in which we find the libc.so.
- std::string system_library_directory_;
+ // Manage cross-references if requested.
+ Cref* cref_;
};
// Some of the information we pass to the relocation routines. We
template<int size, bool big_endian>
struct Relocate_info
{
- // Command line options.
- const General_options* options;
// Symbol table.
const Symbol_table* symtab;
// Layout.
Sized_relobj<size, big_endian>* object;
// Section index of relocation section.
unsigned int reloc_shndx;
+ // Section header of relocation section.
+ const unsigned char* reloc_shdr;
// Section index of section being relocated.
unsigned int data_shndx;
+ // Section header of data section.
+ const unsigned char* data_shdr;
// Return a string showing the location of a relocation. This is
// only used for error messages.
location(size_t relnum, off_t reloffset) const;
};
+// This is used to represent a section in an object and is used as the
+// key type for various section maps.
+typedef std::pair<Object*, unsigned int> Section_id;
+
+// This is similar to Section_id but is used when the section
+// pointers are const.
+typedef std::pair<const Object*, unsigned int> Const_section_id;
+
+// The hash value is based on the address of an object in memory during
+// linking. It is okay to use this for looking up sections but never use
+// this in an unordered container that we want to traverse in a repeatable
+// manner.
+
+struct Section_id_hash
+{
+ size_t operator()(const Section_id& loc) const
+ { return reinterpret_cast<uintptr_t>(loc.first) ^ loc.second; }
+};
+
+struct Const_section_id_hash
+{
+ size_t operator()(const Const_section_id& loc) const
+ { return reinterpret_cast<uintptr_t>(loc.first) ^ loc.second; }
+};
+
+// Return whether INPUT_FILE contains an ELF object start at file
+// offset OFFSET. This sets *START to point to a view of the start of
+// the file. It sets *READ_SIZE to the number of bytes in the view.
+
+extern bool
+is_elf_object(Input_file* input_file, off_t offset,
+ const unsigned char** start, int *read_size);
+
// Return an Object appropriate for the input file. P is BYTES long,
-// and holds the ELF header.
+// and holds the ELF header. If PUNCONFIGURED is not NULL, then if
+// this sees an object the linker is not configured to support, it
+// sets *PUNCONFIGURED to true and returns NULL without giving an
+// error message.
extern Object*
make_elf_object(const std::string& name, Input_file*,
off_t offset, const unsigned char* p,
- section_offset_type bytes);
+ section_offset_type bytes, bool* punconfigured);
} // end namespace gold