// output.h -- manage the output file for gold -*- C++ -*-
-// Copyright 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
+// Copyright (C) 2006-2016 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#ifndef GOLD_OUTPUT_H
#define GOLD_OUTPUT_H
+#include <algorithm>
#include <list>
#include <vector>
class General_options;
class Object;
class Symbol;
-class Output_file;
class Output_merge_base;
class Output_section;
class Relocatable_relocs;
template<int size, bool big_endian>
class Sized_relobj_file;
+// This class represents the output file.
+
+class Output_file
+{
+ public:
+ Output_file(const char* name);
+
+ // Indicate that this is a temporary file which should not be
+ // output.
+ void
+ set_is_temporary()
+ { this->is_temporary_ = true; }
+
+ // Try to open an existing file. Returns false if the file doesn't
+ // exist, has a size of 0 or can't be mmaped. This method is
+ // thread-unsafe. If BASE_NAME is not NULL, use the contents of
+ // that file as the base for incremental linking.
+ bool
+ open_base_file(const char* base_name, bool writable);
+
+ // Open the output file. FILE_SIZE is the final size of the file.
+ // If the file already exists, it is deleted/truncated. This method
+ // is thread-unsafe.
+ void
+ open(off_t file_size);
+
+ // Resize the output file. This method is thread-unsafe.
+ void
+ resize(off_t file_size);
+
+ // Close the output file (flushing all buffered data) and make sure
+ // there are no errors. This method is thread-unsafe.
+ void
+ close();
+
+ // Return the size of this file.
+ off_t
+ filesize()
+ { return this->file_size_; }
+
+ // Return the name of this file.
+ const char*
+ filename()
+ { return this->name_; }
+
+ // We currently always use mmap which makes the view handling quite
+ // simple. In the future we may support other approaches.
+
+ // Write data to the output file.
+ void
+ write(off_t offset, const void* data, size_t len)
+ { memcpy(this->base_ + offset, data, len); }
+
+ // Get a buffer to use to write to the file, given the offset into
+ // the file and the size.
+ unsigned char*
+ get_output_view(off_t start, size_t size)
+ {
+ gold_assert(start >= 0
+ && start + static_cast<off_t>(size) <= this->file_size_);
+ return this->base_ + start;
+ }
+
+ // VIEW must have been returned by get_output_view. Write the
+ // buffer to the file, passing in the offset and the size.
+ void
+ write_output_view(off_t, size_t, unsigned char*)
+ { }
+
+ // Get a read/write buffer. This is used when we want to write part
+ // of the file, read it in, and write it again.
+ unsigned char*
+ get_input_output_view(off_t start, size_t size)
+ { return this->get_output_view(start, size); }
+
+ // Write a read/write buffer back to the file.
+ void
+ write_input_output_view(off_t, size_t, unsigned char*)
+ { }
+
+ // Get a read buffer. This is used when we just want to read part
+ // of the file back it in.
+ const unsigned char*
+ get_input_view(off_t start, size_t size)
+ { return this->get_output_view(start, size); }
+
+ // Release a read bfufer.
+ void
+ free_input_view(off_t, size_t, const unsigned char*)
+ { }
+
+ private:
+ // Map the file into memory or, if that fails, allocate anonymous
+ // memory.
+ void
+ map();
+
+ // Allocate anonymous memory for the file.
+ bool
+ map_anonymous();
+
+ // Map the file into memory.
+ bool
+ map_no_anonymous(bool);
+
+ // Unmap the file from memory (and flush to disk buffers).
+ void
+ unmap();
+
+ // File name.
+ const char* name_;
+ // File descriptor.
+ int o_;
+ // File size.
+ off_t file_size_;
+ // Base of file mapped into memory.
+ unsigned char* base_;
+ // True iff base_ points to a memory buffer rather than an output file.
+ bool map_is_anonymous_;
+ // True if base_ was allocated using new rather than mmap.
+ bool map_is_allocated_;
+ // True if this is a temporary file which should not be output.
+ bool is_temporary_;
+};
+
// An abtract class for data which has to go into the output file.
class Output_data
class Output_file_header : public Output_data
{
public:
- Output_file_header(const Target*,
+ Output_file_header(Target*,
const Symbol_table*,
const Output_segment_headers*);
off_t
do_size() const;
- const Target* target_;
+ Target* target_;
const Symbol_table* symtab_;
const Output_segment_headers* segment_header_;
const Output_section_headers* section_header_;
section_offset_type* poutput) const
{ return this->do_output_offset(object, shndx, offset, poutput); }
- // Return whether this is the merge section for the input section
- // SHNDX in OBJECT. This should return true when output_offset
- // would return true for some values of OFFSET.
- bool
- is_merge_section_for(const Relobj* object, unsigned int shndx) const
- { return this->do_is_merge_section_for(object, shndx); }
-
// Write the contents to a buffer. This is used for sections which
// require postprocessing, such as compression.
void
section_offset_type*) const
{ return false; }
- // The child class may implement is_merge_section_for.
- virtual bool
- do_is_merge_section_for(const Relobj*, unsigned int) const
- { return false; }
-
// The child class may implement write_to_buffer. Most child
// classes can not appear in a compressed section, and they do not
// implement this.
r2) const
{ return this->compare(r2) < 0; }
- private:
- // Record that we need a dynamic symbol index.
- void
- set_needs_dynsym_index();
-
// Return the symbol index.
unsigned int
get_symbol_index() const;
Address
get_address() const;
+ private:
+ // Record that we need a dynamic symbol index.
+ void
+ set_needs_dynsym_index();
+
// Codes for local_sym_index_.
enum
{
void
do_write(Output_file*);
+ // Generic implementation of do_write, allowing a customized
+ // class for writing the output relocation (e.g., for MIPS-64).
+ template<class Output_reloc_writer>
+ void
+ do_write_generic(Output_file* of)
+ {
+ const off_t off = this->offset();
+ const off_t oview_size = this->data_size();
+ unsigned char* const oview = of->get_output_view(off, oview_size);
+
+ if (this->sort_relocs())
+ {
+ gold_assert(dynamic);
+ std::sort(this->relocs_.begin(), this->relocs_.end(),
+ Sort_relocs_comparison());
+ }
+
+ unsigned char* pov = oview;
+ for (typename Relocs::const_iterator p = this->relocs_.begin();
+ p != this->relocs_.end();
+ ++p)
+ {
+ Output_reloc_writer::write(p, pov);
+ pov += reloc_size;
+ }
+
+ gold_assert(pov - oview == oview_size);
+
+ of->write_output_view(off, oview_size, oview);
+
+ // We no longer need the relocation entries.
+ this->relocs_.clear();
+ }
+
// Set the entry size and the link.
void
do_adjust_output_section(Output_section* os);
address, true, true, false, false));
}
+ void
+ add_local_relative(Sized_relobj<size, big_endian>* relobj,
+ unsigned int local_sym_index, unsigned int type,
+ Output_data* od, unsigned int shndx, Address address,
+ bool use_plt_offset)
+ {
+ this->add(od, Output_reloc_type(relobj, local_sym_index, type, shndx,
+ address, true, true, false,
+ use_plt_offset));
+ }
+
// Add a local relocation which does not use a symbol for the relocation,
// but which gets its addend from a symbol.
bool
add_local(Relobj* object, unsigned int sym_index, unsigned int got_type);
+ // Add an entry for a local symbol plus ADDEND to the GOT. This returns
+ // true if this is a new GOT entry, false if the symbol already has a GOT
+ // entry.
+ bool
+ add_local(Relobj* object, unsigned int sym_index, unsigned int got_type,
+ uint64_t addend);
+
// Like add_local, but use the PLT offset of the local symbol if it
// has one.
bool
unsigned int got_type, Output_data_reloc_generic* rel_dyn,
unsigned int r_type);
+ // Add an entry for a local symbol plus ADDEND to the GOT, and add a dynamic
+ // relocation of type R_TYPE for the GOT entry.
+ void
+ add_local_with_rel(Relobj* object, unsigned int sym_index,
+ unsigned int got_type, Output_data_reloc_generic* rel_dyn,
+ unsigned int r_type, uint64_t addend);
+
// Add a pair of entries for a local symbol to the GOT, and add
// a dynamic relocation of type R_TYPE using the section symbol of
// the output section to which input section SHNDX maps, on the first.
Output_data_reloc_generic* rel_dyn,
unsigned int r_type);
+ // Add a pair of entries for a local symbol plus ADDEND to the GOT, and add
+ // a dynamic relocation of type R_TYPE using the section symbol of
+ // the output section to which input section SHNDX maps, on the first.
+ // The first got entry will have a value of zero, the second the
+ // value of the local symbol.
+ void
+ add_local_pair_with_rel(Relobj* object, unsigned int sym_index,
+ unsigned int shndx, unsigned int got_type,
+ Output_data_reloc_generic* rel_dyn,
+ unsigned int r_type, uint64_t addend);
+
// Add a pair of entries for a local symbol to the GOT, and add
// a dynamic relocation of type R_TYPE using STN_UNDEF on the first.
// The first got entry will have a value of zero, the second the
// entry from the start of the GOT.
unsigned int
add_constant(Valtype constant)
- {
- unsigned int got_offset = this->add_got_entry(Got_entry(constant));
- return got_offset;
- }
+ { return this->add_got_entry(Got_entry(constant)); }
+
+ // Add a pair of constants to the GOT. This returns the offset of
+ // the new entry from the start of the GOT.
+ unsigned int
+ add_constant_pair(Valtype c1, Valtype c2)
+ { return this->add_got_entry_pair(Got_entry(c1), Got_entry(c2)); }
// Replace GOT entry I with a new constant.
void
public:
// Create a zero entry.
Got_entry()
- : local_sym_index_(RESERVED_CODE), use_plt_or_tls_offset_(false)
+ : local_sym_index_(RESERVED_CODE), use_plt_or_tls_offset_(false),
+ addend_(0)
{ this->u_.constant = 0; }
// Create a global symbol entry.
Got_entry(Symbol* gsym, bool use_plt_or_tls_offset)
: local_sym_index_(GSYM_CODE),
- use_plt_or_tls_offset_(use_plt_or_tls_offset)
+ use_plt_or_tls_offset_(use_plt_or_tls_offset), addend_(0)
{ this->u_.gsym = gsym; }
// Create a local symbol entry.
Got_entry(Relobj* object, unsigned int local_sym_index,
bool use_plt_or_tls_offset)
: local_sym_index_(local_sym_index),
- use_plt_or_tls_offset_(use_plt_or_tls_offset)
+ use_plt_or_tls_offset_(use_plt_or_tls_offset), addend_(0)
{
gold_assert(local_sym_index != GSYM_CODE
&& local_sym_index != CONSTANT_CODE
this->u_.object = object;
}
+ // Create a local symbol entry plus addend.
+ Got_entry(Relobj* object, unsigned int local_sym_index,
+ bool use_plt_or_tls_offset, uint64_t addend)
+ : local_sym_index_(local_sym_index),
+ use_plt_or_tls_offset_(use_plt_or_tls_offset), addend_(addend)
+ {
+ gold_assert(local_sym_index != GSYM_CODE
+ && local_sym_index != CONSTANT_CODE
+ && local_sym_index != RESERVED_CODE
+ && local_sym_index == this->local_sym_index_);
+ this->u_.object = object;
+ }
+
// Create a constant entry. The constant is a host value--it will
// be swapped, if necessary, when it is written out.
explicit Got_entry(Valtype constant)
// Whether to use the PLT offset of the symbol if it has one.
// For TLS symbols, whether to offset the symbol value.
bool use_plt_or_tls_offset_ : 1;
+ // The addend.
+ uint64_t addend_;
};
typedef std::vector<Got_entry> Got_entries;
add_string(elfcpp::DT tag, const std::string& str)
{ this->add_string(tag, str.c_str()); }
+ // Add a new dynamic entry with custom value.
+ void
+ add_custom(elfcpp::DT tag)
+ { this->add_entry(Dynamic_entry(tag)); }
+
protected:
// Adjust the output section to set the entry size.
void
: tag_(tag), offset_(DYNAMIC_STRING)
{ this->u_.str = str; }
+ // Create an entry with a custom value.
+ Dynamic_entry(elfcpp::DT tag)
+ : tag_(tag), offset_(DYNAMIC_CUSTOM)
+ { }
+
// Return the tag of this entry.
elfcpp::DT
tag() const
// Symbol adress.
DYNAMIC_SYMBOL = -3U,
// String.
- DYNAMIC_STRING = -4U
+ DYNAMIC_STRING = -4U,
+ // Custom value.
+ DYNAMIC_CUSTOM = -5U
// Any other value indicates a section address plus OFFSET.
};
public:
Output_section_lookup_maps()
: is_valid_(true), merge_sections_by_properties_(),
- merge_sections_by_id_(), relaxed_input_sections_by_id_()
+ relaxed_input_sections_by_id_()
{ }
// Whether the maps are valid.
clear()
{
this->merge_sections_by_properties_.clear();
- this->merge_sections_by_id_.clear();
this->relaxed_input_sections_by_id_.clear();
// A cleared map is valid.
this->is_valid_ = true;
return p != this->merge_sections_by_properties_.end() ? p->second : NULL;
}
- // Find a merge section by section ID of a merge input section. Return NULL
- // if none is found.
- Output_merge_base*
- find_merge_section(const Object* object, unsigned int shndx) const
- {
- gold_assert(this->is_valid_);
- Merge_sections_by_id::const_iterator p =
- this->merge_sections_by_id_.find(Const_section_id(object, shndx));
- return p != this->merge_sections_by_id_.end() ? p->second : NULL;
- }
-
// Add a merge section pointed by POMB with properties MSP.
void
add_merge_section(const Merge_section_properties& msp,
gold_assert(result.second);
}
- // Add a mapping from a merged input section in OBJECT with index SHNDX
- // to a merge output section pointed by POMB.
- void
- add_merge_input_section(const Object* object, unsigned int shndx,
- Output_merge_base* pomb)
- {
- Const_section_id csid(object, shndx);
- std::pair<Const_section_id, Output_merge_base*> value(csid, pomb);
- std::pair<Merge_sections_by_id::iterator, bool> result =
- this->merge_sections_by_id_.insert(value);
- gold_assert(result.second);
- }
-
// Find a relaxed input section of OBJECT with index SHNDX.
Output_relaxed_input_section*
- find_relaxed_input_section(const Object* object, unsigned int shndx) const
+ find_relaxed_input_section(const Relobj* object, unsigned int shndx) const
{
gold_assert(this->is_valid_);
Relaxed_input_sections_by_id::const_iterator p =
}
private:
- typedef Unordered_map<Const_section_id, Output_merge_base*,
- Const_section_id_hash>
- Merge_sections_by_id;
-
typedef Unordered_map<Merge_section_properties, Output_merge_base*,
Merge_section_properties::hash,
Merge_section_properties::equal_to>
bool is_valid_;
// Merge sections by merge section properties.
Merge_sections_by_properties merge_sections_by_properties_;
- // Merge sections by section IDs.
- Merge_sections_by_id merge_sections_by_id_;
// Relaxed sections by section IDs.
Relaxed_input_sections_by_id relaxed_input_sections_by_id_;
};
void
update_flags_for_input_section(elfcpp::Elf_Xword flags);
+ // Set the output section flags.
+ void
+ set_flags(elfcpp::Elf_Xword flags)
+ { this->flags_ = flags; }
+
// Return the entsize field.
uint64_t
entsize() const
this->dynsym_index_ = index;
}
+ // Sort the attached input sections.
+ void
+ sort_attached_input_sections();
+
// Return whether the input sections sections attachd to this output
// section may require sorting. This is used to handle constructor
// priorities compatibly with GNU ld.
section_offset_type offset,
section_offset_type* poutput) const;
- // Return whether this is the merge section for the input section
- // SHNDX in OBJECT.
- bool
- is_merge_section_for(const Relobj* object, unsigned int shndx) const;
-
// Write out the data. This does nothing for an input section.
void
write(Output_file*);
input_sections() const
{ return this->input_sections_; }
+ Input_section_list&
+ input_sections()
+ { return this->input_sections_; }
+
protected:
// Return the output section--i.e., the object itself.
Output_section*
const Input_section_sort_entry&) const;
};
+ // This is the sort comparison function for .text to sort sections with
+ // prefixes .text.{unlikely,exit,startup,hot} before other sections.
+ struct Input_section_sort_section_prefix_special_ordering_compare
+ {
+ bool
+ operator()(const Input_section_sort_entry&,
+ const Input_section_sort_entry&) const;
+ };
+
+ // This is the sort comparison function for sorting sections by name.
+ struct Input_section_sort_section_name_compare
+ {
+ bool
+ operator()(const Input_section_sort_entry&,
+ const Input_section_sort_entry&) const;
+ };
+
// Fill data. This is used to fill in data between input sections.
// It is also used for data statements (BYTE, WORD, etc.) in linker
// scripts. When we have to keep track of the input sections, we
add_output_merge_section(Output_section_data* posd, bool is_string,
uint64_t entsize);
- // Sort the attached input sections.
- void
- sort_attached_input_sections();
-
// Find the merge section into which an input section with index SHNDX in
// OBJECT has been added. Return NULL if none found.
- Output_section_data*
+ const Output_section_data*
find_merge_section(const Relobj* object, unsigned int shndx) const;
// Build a relaxation map.
// address of the immediately following segment. Update *POFF and
// *PSHNDX. This should only be called for a PT_LOAD segment.
uint64_t
- set_section_addresses(Layout*, bool reset, uint64_t addr,
+ set_section_addresses(const Target*, Layout*, bool reset, uint64_t addr,
unsigned int* increase_relro, bool* has_relro,
off_t* poff, unsigned int* pshndx);
bool is_unique_segment_ : 1;
};
-// This class represents the output file.
-
-class Output_file
-{
- public:
- Output_file(const char* name);
-
- // Indicate that this is a temporary file which should not be
- // output.
- void
- set_is_temporary()
- { this->is_temporary_ = true; }
-
- // Try to open an existing file. Returns false if the file doesn't
- // exist, has a size of 0 or can't be mmaped. This method is
- // thread-unsafe. If BASE_NAME is not NULL, use the contents of
- // that file as the base for incremental linking.
- bool
- open_base_file(const char* base_name, bool writable);
-
- // Open the output file. FILE_SIZE is the final size of the file.
- // If the file already exists, it is deleted/truncated. This method
- // is thread-unsafe.
- void
- open(off_t file_size);
-
- // Resize the output file. This method is thread-unsafe.
- void
- resize(off_t file_size);
-
- // Close the output file (flushing all buffered data) and make sure
- // there are no errors. This method is thread-unsafe.
- void
- close();
-
- // Return the size of this file.
- off_t
- filesize()
- { return this->file_size_; }
-
- // Return the name of this file.
- const char*
- filename()
- { return this->name_; }
-
- // We currently always use mmap which makes the view handling quite
- // simple. In the future we may support other approaches.
-
- // Write data to the output file.
- void
- write(off_t offset, const void* data, size_t len)
- { memcpy(this->base_ + offset, data, len); }
-
- // Get a buffer to use to write to the file, given the offset into
- // the file and the size.
- unsigned char*
- get_output_view(off_t start, size_t size)
- {
- gold_assert(start >= 0
- && start + static_cast<off_t>(size) <= this->file_size_);
- return this->base_ + start;
- }
-
- // VIEW must have been returned by get_output_view. Write the
- // buffer to the file, passing in the offset and the size.
- void
- write_output_view(off_t, size_t, unsigned char*)
- { }
-
- // Get a read/write buffer. This is used when we want to write part
- // of the file, read it in, and write it again.
- unsigned char*
- get_input_output_view(off_t start, size_t size)
- { return this->get_output_view(start, size); }
-
- // Write a read/write buffer back to the file.
- void
- write_input_output_view(off_t, size_t, unsigned char*)
- { }
-
- // Get a read buffer. This is used when we just want to read part
- // of the file back it in.
- const unsigned char*
- get_input_view(off_t start, size_t size)
- { return this->get_output_view(start, size); }
-
- // Release a read bfufer.
- void
- free_input_view(off_t, size_t, const unsigned char*)
- { }
-
- private:
- // Map the file into memory or, if that fails, allocate anonymous
- // memory.
- void
- map();
-
- // Allocate anonymous memory for the file.
- bool
- map_anonymous();
-
- // Map the file into memory.
- bool
- map_no_anonymous(bool);
-
- // Unmap the file from memory (and flush to disk buffers).
- void
- unmap();
-
- // File name.
- const char* name_;
- // File descriptor.
- int o_;
- // File size.
- off_t file_size_;
- // Base of file mapped into memory.
- unsigned char* base_;
- // True iff base_ points to a memory buffer rather than an output file.
- bool map_is_anonymous_;
- // True if base_ was allocated using new rather than mmap.
- bool map_is_allocated_;
- // True if this is a temporary file which should not be output.
- bool is_temporary_;
-};
-
} // End namespace gold.
#endif // !defined(GOLD_OUTPUT_H)