// ehframe.h -- handle exception frame sections for gold -*- C++ -*-
-// Copyright 2006, 2007 Free Software Foundation, Inc.
+// Copyright (C) 2006-2014 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#ifndef GOLD_EHFRAME_H
#define GOLD_EHFRAME_H
+#include <map>
+#include <set>
+#include <vector>
+
#include "output.h"
#include "merge.h"
// time and when a shared object is loaded, and the time required to
// deregister the exception handlers when a shared object is unloaded.
-// FIXME: gcc supports using storing a sorted lookup table for the
-// FDEs in the PT_GNU_EH_FRAME segment, but we do not yet generate
-// that.
-
class Eh_frame_hdr : public Output_section_data
{
public:
// Record an FDE.
void
- record_fde(off_t fde_offset, unsigned char fde_encoding)
+ record_fde(section_offset_type fde_offset, unsigned char fde_encoding)
{
if (!this->any_unrecognized_eh_frame_sections_)
this->fde_offsets_.push_back(std::make_pair(fde_offset, fde_encoding));
}
+ protected:
// Set the final data size.
void
- do_set_address(uint64_t address, off_t offset);
+ set_final_data_size();
// Write the data to the file.
void
do_write(Output_file*);
+ // Write to a map file.
+ void
+ do_print_to_mapfile(Mapfile* mapfile) const
+ { mapfile->print_output_data(this, _("** eh_frame_hdr")); }
+
private:
// Write the data to the file with the right endianness.
template<int size, bool big_endian>
// The data we record for one FDE: the offset of the FDE within the
// .eh_frame section, and the FDE encoding.
- typedef std::pair<off_t, unsigned char> Fde_offset;
+ typedef std::pair<section_offset_type, unsigned char> Fde_offset;
// The list of information we record for an FDE.
typedef std::vector<Fde_offset> Fde_offsets;
// Return the PC to which an FDE refers.
template<int size, bool big_endian>
typename elfcpp::Elf_types<size>::Elf_Addr
- get_fde_pc(const unsigned char* eh_frame_contents,
- off_t fde_offset, unsigned char fde_encoding);
+ get_fde_pc(typename elfcpp::Elf_types<size>::Elf_Addr eh_frame_address,
+ const unsigned char* eh_frame_contents,
+ section_offset_type fde_offset, unsigned char fde_encoding);
// Convert Fde_offsets to Fde_addresses.
template<int size, bool big_endian>
class Fde
{
public:
- Fde(Relobj* object, unsigned int shndx, off_t input_offset,
+ Fde(Relobj* object, unsigned int shndx, section_offset_type input_offset,
const unsigned char* contents, size_t length)
- : object_(object), shndx_(shndx), input_offset_(input_offset),
+ : object_(object),
contents_(reinterpret_cast<const char*>(contents), length)
- { }
+ {
+ this->u_.from_object.shndx = shndx;
+ this->u_.from_object.input_offset = input_offset;
+ }
+
+ // Create an FDE associated with a PLT.
+ Fde(Output_data* plt, const unsigned char* contents, size_t length,
+ bool post_map)
+ : object_(NULL),
+ contents_(reinterpret_cast<const char*>(contents), length)
+ {
+ this->u_.from_linker.plt = plt;
+ this->u_.from_linker.post_map = post_map;
+ }
// Return the length of this FDE. Add 4 for the length and 4 for
// the offset to the CIE.
length() const
{ return this->contents_.length() + 8; }
- // Add a mapping for this FDE to MERGE_MAP.
+ // Add a mapping for this FDE to MERGE_MAP, so that relocations
+ // against the FDE are applied to right part of the output file.
void
- add_mapping(off_t output_offset, Merge_map* merge_map) const
+ add_mapping(section_offset_type output_offset, Merge_map* merge_map) const
{
- merge_map->add_mapping(this->object_, this->shndx_,
- this->input_offset_, this->length(),
- output_offset);
+ if (this->object_ != NULL)
+ merge_map->add_mapping(this->object_, this->u_.from_object.shndx,
+ this->u_.from_object.input_offset, this->length(),
+ output_offset);
}
+ // Return whether this FDE was added after merge mapping.
+ bool
+ post_map()
+ { return this->object_ == NULL && this->u_.from_linker.post_map; }
+
// Write the FDE to OVIEW starting at OFFSET. FDE_ENCODING is the
- // encoding, from the CIE. Record the FDE in EH_FRAME_HDR. Return
- // the new offset.
+ // encoding, from the CIE. Round up the bytes to ADDRALIGN if
+ // necessary. ADDRESS is the virtual address of OVIEW. Record the
+ // FDE in EH_FRAME_HDR. Return the new offset.
template<int size, bool big_endian>
- off_t
- write(unsigned char* oview, off_t offset, off_t cie_offset,
- unsigned char fde_encoding, Eh_frame_hdr* eh_frame_hdr);
+ section_offset_type
+ write(unsigned char* oview, section_offset_type offset,
+ uint64_t address, unsigned int addralign,
+ section_offset_type cie_offset, unsigned char fde_encoding,
+ Eh_frame_hdr* eh_frame_hdr);
private:
- // The object in which this FDE was seen.
+ // The object in which this FDE was seen. This will be NULL for a
+ // linker generated FDE.
Relobj* object_;
- // Input section index for this FDE.
- unsigned int shndx_;
- // Offset within the input section for this FDE.
- off_t input_offset_;
+ union
+ {
+ // These fields are used if the FDE is from an input object (the
+ // object_ field is not NULL).
+ struct
+ {
+ // Input section index for this FDE.
+ unsigned int shndx;
+ // Offset within the input section for this FDE.
+ section_offset_type input_offset;
+ } from_object;
+ // This field is used if the FDE is generated by the linker (the
+ // object_ field is NULL).
+ struct
+ {
+ // The only linker generated FDEs are for PLT sections, and this
+ // points to the PLT section.
+ Output_data* plt;
+ // Set if the FDE was added after merge mapping.
+ bool post_map;
+ } from_linker;
+ } u_;
// FDE data.
std::string contents_;
};
+// A FDE plus some info from a CIE to allow later writing of the FDE.
+
+struct Post_fde
+{
+ Post_fde(Fde* f, section_offset_type cie_off, unsigned char encoding)
+ : fde(f), cie_offset(cie_off), fde_encoding(encoding)
+ { }
+
+ Fde* fde;
+ section_offset_type cie_offset;
+ unsigned char fde_encoding;
+};
+
+typedef std::vector<Post_fde> Post_fdes;
+
// This class holds a CIE.
class Cie
{
public:
- Cie(Relobj* object, unsigned int shndx, off_t input_offset,
+ Cie(Relobj* object, unsigned int shndx, section_offset_type input_offset,
unsigned char fde_encoding, const char* personality_name,
const unsigned char* contents, size_t length)
: object_(object),
// followed by all its FDEs. ADDRALIGN is the required address
// alignment, typically 4 or 8. This updates MERGE_MAP with the
// mapping. It returns the new output offset.
- off_t
- set_output_offset(off_t output_offset, unsigned int addralign, Merge_map*);
-
- // Write the CIE to OVIEW starting at OFFSET. EH_FRAME_HDR is the
- // exception frame header for FDE recording. Return the new offset.
+ section_offset_type
+ set_output_offset(section_offset_type output_offset, unsigned int addralign,
+ Merge_map*);
+
+ // Write the CIE to OVIEW starting at OFFSET. Round up the bytes to
+ // ADDRALIGN. ADDRESS is the virtual address of OVIEW.
+ // EH_FRAME_HDR is the exception frame header for FDE recording.
+ // POST_FDES stashes FDEs created after mappings were done, for later
+ // writing. Return the new offset.
template<int size, bool big_endian>
- off_t
- write(unsigned char* oview, off_t offset, Eh_frame_hdr* eh_frame_hdr);
+ section_offset_type
+ write(unsigned char* oview, section_offset_type offset, uint64_t address,
+ unsigned int addralign, Eh_frame_hdr* eh_frame_hdr,
+ Post_fdes* post_fdes);
friend bool operator<(const Cie&, const Cie&);
friend bool operator==(const Cie&, const Cie&);
// The class is not assignable.
Cie& operator=(const Cie&);
- // The object in which this CIE was first seen.
+ // The object in which this CIE was first seen. This will be NULL
+ // for a linker generated CIE.
Relobj* object_;
- // Input section index for this CIE.
+ // Input section index for this CIE. This will be 0 for a linker
+ // generated CIE.
unsigned int shndx_;
- // Offset within the input section for this CIE.
- off_t input_offset_;
+ // Offset within the input section for this CIE. This will be 0 for
+ // a linker generated CIE.
+ section_offset_type input_offset_;
// The encoding of the FDE. This is a DW_EH_PE code.
unsigned char fde_encoding_;
// The name of the personality routine. This will be the name of a
// data.
template<int size, bool big_endian>
bool
- add_ehframe_input_section(Sized_relobj<size, big_endian>* object,
+ add_ehframe_input_section(Sized_relobj_file<size, big_endian>* object,
const unsigned char* symbols,
- off_t symbols_size,
+ section_size_type symbols_size,
const unsigned char* symbol_names,
- off_t symbol_names_size,
+ section_size_type symbol_names_size,
unsigned int shndx, unsigned int reloc_shndx,
unsigned int reloc_type);
+ // Add a CIE and an FDE for a PLT section, to permit unwinding
+ // through a PLT. The FDE data should start with 8 bytes of zero,
+ // which will be replaced by a 4 byte PC relative reference to the
+ // address of PLT and a 4 byte size of PLT.
+ void
+ add_ehframe_for_plt(Output_data* plt, const unsigned char* cie_data,
+ size_t cie_length, const unsigned char* fde_data,
+ size_t fde_length);
+
// Return the number of FDEs.
unsigned int
fde_count() const;
+ protected:
// Set the final data size.
void
- do_set_address(uint64_t, off_t);
+ set_final_data_size();
// Return the output address for an input address.
bool
- do_output_offset(const Relobj*, unsigned int shndx, off_t offset,
- off_t* poutput) const;
+ do_output_offset(const Relobj*, unsigned int shndx,
+ section_offset_type offset,
+ section_offset_type* poutput) const;
+
+ // Return whether this is the merge section for an input section.
+ bool
+ do_is_merge_section_for(const Relobj*, unsigned int shndx) const;
// Write the data to the file.
void
do_write(Output_file*);
+ // Write to a map file.
+ void
+ do_print_to_mapfile(Mapfile* mapfile) const
+ { mapfile->print_output_data(this, _("** eh_frame")); }
+
private:
// The comparison routine for the CIE map.
struct Cie_less
{ return *cie1 < *cie2; }
};
- // A mapping from unique CIEs to their offset in the output file.
- typedef std::map<Cie*, uint64_t, Cie_less> Cie_offsets;
+ // A set of unique CIEs.
+ typedef std::set<Cie*, Cie_less> Cie_offsets;
- // A list of unmergeable CIEs with their offsets.
- typedef std::vector<std::pair<Cie*, uint64_t> > Unmergeable_cie_offsets;
+ // A list of unmergeable CIEs.
+ typedef std::vector<Cie*> Unmergeable_cie_offsets;
// A mapping from offsets to CIEs. This is used while reading an
// input section.
// The implementation of add_ehframe_input_section.
template<int size, bool big_endian>
bool
- do_add_ehframe_input_section(Sized_relobj<size, big_endian>* object,
+ do_add_ehframe_input_section(Sized_relobj_file<size, big_endian>* object,
const unsigned char* symbols,
- off_t symbols_size,
+ section_size_type symbols_size,
const unsigned char* symbol_names,
- off_t symbol_names_size,
+ section_size_type symbol_names_size,
unsigned int shndx,
unsigned int reloc_shndx,
unsigned int reloc_type,
const unsigned char* pcontents,
- off_t contents_len,
+ section_size_type contents_len,
New_cies*);
// Read a CIE.
template<int size, bool big_endian>
bool
- read_cie(Sized_relobj<size, big_endian>* object,
+ read_cie(Sized_relobj_file<size, big_endian>* object,
unsigned int shndx,
const unsigned char* symbols,
- off_t symbols_size,
+ section_size_type symbols_size,
const unsigned char* symbol_names,
- off_t symbol_names_size,
+ section_size_type symbol_names_size,
const unsigned char* pcontents,
const unsigned char* pcie,
- const unsigned char *pcieend,
+ const unsigned char* pcieend,
Track_relocs<size, big_endian>* relocs,
Offsets_to_cie* cies,
New_cies* new_cies);
// Read an FDE.
template<int size, bool big_endian>
bool
- read_fde(Sized_relobj<size, big_endian>* object,
+ read_fde(Sized_relobj_file<size, big_endian>* object,
unsigned int shndx,
const unsigned char* symbols,
- off_t symbols_size,
+ section_size_type symbols_size,
const unsigned char* pcontents,
unsigned int offset,
const unsigned char* pfde,
- const unsigned char *pfdeend,
+ const unsigned char* pfdeend,
Track_relocs<size, big_endian>* relocs,
Offsets_to_cie* cies);
Unmergeable_cie_offsets unmergeable_cie_offsets_;
// A mapping from input sections to the output section.
Merge_map merge_map_;
+ // Whether we have created the mappings to the output section.
+ bool mappings_are_done_;
+ // The final data size. This is only set if mappings_are_done_ is
+ // true.
+ section_size_type final_data_size_;
};
} // End namespace gold.