Generate a complete exception frame header. Discard duplicate

exception frame information.

1 files changed, 358 insertions, 1 deletions

diff --git a/gold/ehframe.h b/gold/ehframe.h
index 0641ac8..6a584f9 100644
--- a/gold/ehframe.h
+++ b/gold/ehframe.h
@@ -24,10 +24,16 @@
 #define GOLD_EHFRAME_H
 
 #include "output.h"
+#include "merge.h"
 
 namespace gold
 {
 
+template<int size, bool big_endian>
+class Track_relocs;
+
+class Eh_frame;
+
 // This class manages the .eh_frame_hdr section, which holds the data
 // for the PT_GNU_EH_FRAME segment.  gcc's unwind support code uses
 // the PT_GNU_EH_FRAME segment to find the list of FDEs.  This saves
@@ -42,7 +48,20 @@ namespace gold
 class Eh_frame_hdr : public Output_section_data
 {
  public:
-  Eh_frame_hdr(Output_section* eh_frame_section);
+  Eh_frame_hdr(Output_section* eh_frame_section, const Eh_frame*);
+
+  // Record that we found an unrecognized .eh_frame section.
+  void
+  found_unrecognized_eh_frame_section()
+  { this->any_unrecognized_eh_frame_sections_ = true; }
+
+  // Record an FDE.
+  void
+  record_fde(off_t 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));
+  }
 
   // Set the final data size.
   void
@@ -53,8 +72,346 @@ class Eh_frame_hdr : public Output_section_data
   do_write(Output_file*);
 
  private:
+  // Write the data to the file with the right endianness.
+  template<int size, bool big_endian>
+  void
+  do_sized_write(Output_file*);
+
+  // 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;
+
+  // The list of information we record for an FDE.
+  typedef std::vector<Fde_offset> Fde_offsets;
+
+  // When writing out the header, we convert the FDE offsets into FDE
+  // addresses.  This is a list of pairs of the offset from the header
+  // to the FDE PC and to the FDE itself.
+  template<int size>
+  class Fde_addresses
+  {
+   public:
+    typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
+    typedef typename std::pair<Address, Address> Fde_address;
+    typedef typename std::vector<Fde_address> Fde_address_list;
+    typedef typename Fde_address_list::iterator iterator;
+
+    Fde_addresses(unsigned int reserve)
+      : fde_addresses_()
+    { this->fde_addresses_.reserve(reserve); }
+
+    void
+    push_back(Address pc_address, Address fde_address)
+    {
+      this->fde_addresses_.push_back(std::make_pair(pc_address, fde_address));
+    }
+
+    iterator
+    begin()
+    { return this->fde_addresses_.begin(); }
+
+    iterator
+    end()
+    { return this->fde_addresses_.end(); }
+
+   private:
+    Fde_address_list fde_addresses_;
+  };
+
+  // Compare Fde_address objects.
+  template<int size>
+  struct Fde_address_compare
+  {
+    bool
+    operator()(const typename Fde_addresses<size>::Fde_address& f1,
+	       const typename Fde_addresses<size>::Fde_address& f2) const
+    { return f1.first < f2.first; }
+  };
+
+  // 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);
+
+  // Convert Fde_offsets to Fde_addresses.
+  template<int size, bool big_endian>
+  void
+  get_fde_addresses(Output_file* of,
+		    const Fde_offsets* fde_offsets,
+		    Fde_addresses<size>* fde_addresses);
+
   // The .eh_frame section.
   Output_section* eh_frame_section_;
+  // The .eh_frame section data.
+  const Eh_frame* eh_frame_data_;
+  // Data from the FDEs in the .eh_frame sections.
+  Fde_offsets fde_offsets_;
+  // Whether we found any .eh_frame sections which we could not
+  // process.
+  bool any_unrecognized_eh_frame_sections_;
+};
+
+// This class holds an FDE.
+
+class Fde
+{
+ public:
+  Fde(Relobj* object, unsigned int shndx, off_t input_offset,
+      const unsigned char* contents, size_t length)
+    : object_(object), shndx_(shndx), input_offset_(input_offset),
+      contents_(reinterpret_cast<const char*>(contents), length)
+  { }
+
+  // Return the length of this FDE.  Add 4 for the length and 4 for
+  // the offset to the CIE.
+  size_t
+  length() const
+  { return this->contents_.length() + 8; }
+
+  // Add a mapping for this FDE to MERGE_MAP.
+  void
+  add_mapping(off_t output_offset, Merge_map* merge_map) const
+  {
+    merge_map->add_mapping(this->object_, this->shndx_,
+			   this->input_offset_, this->length(),
+			   output_offset);
+  }
+
+  // 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.
+  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);
+
+ private:
+  // The object in which this FDE was seen.
+  Relobj* object_;
+  // Input section index for this FDE.
+  unsigned int shndx_;
+  // Offset within the input section for this FDE.
+  off_t input_offset_;
+  // FDE data.
+  std::string contents_;
+};
+
+// This class holds a CIE.
+
+class Cie
+{
+ public:
+  Cie(Relobj* object, unsigned int shndx, off_t input_offset,
+      unsigned char fde_encoding, const char* personality_name,
+      const unsigned char* contents, size_t length)
+    : object_(object),
+      shndx_(shndx),
+      input_offset_(input_offset),
+      fde_encoding_(fde_encoding),
+      personality_name_(personality_name),
+      fdes_(),
+      contents_(reinterpret_cast<const char*>(contents), length)
+  { }
+
+  ~Cie();
+
+  // We permit copying a CIE when there are no FDEs.  This is
+  // convenient in the code which creates them.
+  Cie(const Cie& cie)
+    : object_(cie.object_),
+      shndx_(cie.shndx_),
+      input_offset_(cie.input_offset_),
+      fde_encoding_(cie.fde_encoding_),
+      personality_name_(cie.personality_name_),
+      fdes_(),
+      contents_(cie.contents_)
+  { gold_assert(cie.fdes_.empty()); }
+
+  // Add an FDE associated with this CIE.
+  void
+  add_fde(Fde* fde)
+  { this->fdes_.push_back(fde); }
+
+  // Return the number of FDEs.
+  unsigned int
+  fde_count() const
+  { return this->fdes_.size(); }
+
+  // Set the output offset of this CIE to OUTPUT_OFFSET.  It will be
+  // 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.
+  template<int size, bool big_endian>
+  off_t
+  write(unsigned char* oview, off_t offset, Eh_frame_hdr* eh_frame_hdr);
+
+  friend bool operator<(const Cie&, const Cie&);
+  friend bool operator==(const Cie&, const Cie&);
+
+ private:
+  // The class is not assignable.
+  Cie& operator=(const Cie&);
+
+  // The object in which this CIE was first seen.
+  Relobj* object_;
+  // Input section index for this CIE.
+  unsigned int shndx_;
+  // Offset within the input section for this CIE.
+  off_t 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
+  // global symbol, or will be the empty string.
+  std::string personality_name_;
+  // List of FDEs.
+  std::vector<Fde*> fdes_;
+  // CIE data.
+  std::string contents_;
+};
+
+extern bool operator<(const Cie&, const Cie&);
+extern bool operator==(const Cie&, const Cie&);
+
+// This class manages .eh_frame sections.  It discards duplicate
+// exception information.
+
+class Eh_frame : public Output_section_data
+{
+ public:
+  Eh_frame();
+
+  // Record the associated Eh_frame_hdr, if any.
+  void
+  set_eh_frame_hdr(Eh_frame_hdr* hdr)
+  { this->eh_frame_hdr_ = hdr; }
+
+  // Add the input section SHNDX in OBJECT.  SYMBOLS is the contents
+  // of the symbol table section (size SYMBOLS_SIZE), SYMBOL_NAMES is
+  // the symbol names section (size SYMBOL_NAMES_SIZE).  RELOC_SHNDX
+  // is the relocation section if any (0 for none, -1U for multiple).
+  // RELOC_TYPE is the type of the relocation section if any.  This
+  // returns whether the section was incorporated into the .eh_frame
+  // data.
+  template<int size, bool big_endian>
+  bool
+  add_ehframe_input_section(Sized_relobj<size, big_endian>* object,
+			    const unsigned char* symbols,
+			    off_t symbols_size,
+			    const unsigned char* symbol_names,
+			    off_t symbol_names_size,
+			    unsigned int shndx, unsigned int reloc_shndx,
+			    unsigned int reloc_type);
+
+  // Return the number of FDEs.
+  unsigned int
+  fde_count() const;
+
+  // Set the final data size.
+  void
+  do_set_address(uint64_t, off_t);
+
+  // Return the output address for an input address.
+  bool
+  do_output_offset(const Relobj*, unsigned int shndx, off_t offset,
+		   off_t* poutput) const;
+
+  // Write the data to the file.
+  void
+  do_write(Output_file*);
+
+ private:
+  // The comparison routine for the CIE map.
+  struct Cie_less
+  {
+    bool
+    operator()(const Cie* cie1, const Cie* cie2) const
+    { 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 list of unmergeable CIEs with their offsets.
+  typedef std::vector<std::pair<Cie*, uint64_t> > Unmergeable_cie_offsets;
+
+  // A mapping from offsets to CIEs.  This is used while reading an
+  // input section.
+  typedef std::map<uint64_t, Cie*> Offsets_to_cie;
+
+  // A list of CIEs, and a bool indicating whether the CIE is
+  // mergeable.
+  typedef std::vector<std::pair<Cie*, bool> > New_cies;
+
+  // Skip an LEB128.
+  static bool
+  skip_leb128(const unsigned char**, const unsigned char*);
+
+  // 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,
+			       const unsigned char* symbols,
+			       off_t symbols_size,
+			       const unsigned char* symbol_names,
+			       off_t symbol_names_size,
+			       unsigned int shndx,
+			       unsigned int reloc_shndx,
+			       unsigned int reloc_type,
+			       const unsigned char* pcontents,
+			       off_t contents_len,
+			       New_cies*);
+
+  // Read a CIE.
+  template<int size, bool big_endian>
+  bool
+  read_cie(Sized_relobj<size, big_endian>* object,
+	   unsigned int shndx,
+	   const unsigned char* symbols,
+	   off_t symbols_size,
+	   const unsigned char* symbol_names,
+	   off_t symbol_names_size,
+	   const unsigned char* pcontents,
+	   const unsigned char* pcie,
+	   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,
+	   unsigned int shndx,
+	   const unsigned char* symbols,
+	   off_t symbols_size,
+	   const unsigned char* pcontents,
+	   unsigned int offset,
+	   const unsigned char* pfde,
+	   const unsigned char *pfdeend,
+	   Track_relocs<size, big_endian>* relocs,
+	   Offsets_to_cie* cies);
+
+  // Template version of write function.
+  template<int size, bool big_endian>
+  void
+  do_sized_write(unsigned char* oview);
+
+  // The exception frame header, if any.
+  Eh_frame_hdr* eh_frame_hdr_;
+  // A mapping from all unique CIEs to their offset in the output
+  // file.
+  Cie_offsets cie_offsets_;
+  // A mapping from unmergeable CIEs to their offset in the output
+  // file.
+  Unmergeable_cie_offsets unmergeable_cie_offsets_;
+  // A mapping from input sections to the output section.
+  Merge_map merge_map_;
 };
 
 } // End namespace gold.