From Craig Silverstein: Templatize the Dwarf reader.

gold/dwarf_reader.cc

@@ -118,7 +118,8 @@ ResetLineStateMachine(struct LineStateMachine* lsm, bool default_is_stmt)
 
 template<int size, bool big_endian>
 const unsigned char*
-Dwarf_line_info::read_header_prolog(const unsigned char* lineptr)
+Dwarf_line_info<size, big_endian>::read_header_prolog(
+    const unsigned char* lineptr)
 {
   uint32_t initial_length = elfcpp::Swap<32, big_endian>::readval(lineptr);
   lineptr += 4;
@@ -176,8 +177,10 @@ Dwarf_line_info::read_header_prolog(const unsigned char* lineptr)
 // The header for a debug_line section is mildly complicated, because
 // the line info is very tightly encoded.
 
+template<int size, bool big_endian>
 const unsigned char*
-Dwarf_line_info::read_header_tables(const unsigned char* lineptr)
+Dwarf_line_info<size, big_endian>::read_header_tables(
+    const unsigned char* lineptr)
 {
   // It is legal for the directory entry table to be empty.
   if (*lineptr)
@@ -231,11 +234,10 @@ Dwarf_line_info::read_header_tables(const unsigned char* lineptr)
 // simpler) code, but would bloat the binary.  Speed isn't important
 // here.
 
+template<int size, bool big_endian>
 bool
-Dwarf_line_info::process_one_opcode(int size, bool big_endian,
+Dwarf_line_info<size, big_endian>::process_one_opcode(
-                                    const unsigned char* start,
+    const unsigned char* start, struct LineStateMachine* lsm, size_t* len)
-                                    struct LineStateMachine* lsm,
-                                    size_t* len)
 {
   size_t oplen = 0;
   size_t templen;
@@ -312,10 +314,7 @@ Dwarf_line_info::process_one_opcode(int size, bool big_endian,
     case elfcpp::DW_LNS_fixed_advance_pc:
       {
         int advance_address;
-        if (big_endian)
+        advance_address = elfcpp::Swap<16, big_endian>::readval(start);
-          advance_address = elfcpp::Swap<16, true>::readval(start);
-        else
-          advance_address = elfcpp::Swap<16, false>::readval(start);
         oplen += 2;
         lsm->address += advance_address;
       }
@@ -349,16 +348,7 @@ Dwarf_line_info::process_one_opcode(int size, bool big_endian,
 
           case elfcpp::DW_LNE_set_address:
             // FIXME: modify the address based on the reloc
-            if (size == 32 && big_endian == false)
+            lsm->address = elfcpp::Swap<size, big_endian>::readval(start);
-              lsm->address = elfcpp::Swap<32, false>::readval(start);
-            else if (size == 32 && big_endian == true)
-              lsm->address = elfcpp::Swap<32, true>::readval(start);
-            else if (size == 64 && big_endian == false)
-              lsm->address = elfcpp::Swap<64, false>::readval(start);
-            else if (size == 64 && big_endian == true)
-              lsm->address = elfcpp::Swap<64, true>::readval(start);
-            else
-              gold_assert(false);  // We need to implement more cases, then.
             // FIXME: set lsm->shndx from the reloc
             lsm->shndx = 1;
             break;
@@ -408,9 +398,9 @@ Dwarf_line_info::process_one_opcode(int size, bool big_endian,
 // Read the debug information at LINEPTR and store it in the line
 // number map.
 
+template<int size, bool big_endian>
 unsigned const char*
-Dwarf_line_info::read_lines(int size, bool big_endian,
+Dwarf_line_info<size, big_endian>::read_lines(unsigned const char* lineptr)
-                            unsigned const char* lineptr)
 {
   struct LineStateMachine lsm;
 
@@ -431,8 +421,7 @@ Dwarf_line_info::read_lines(int size, bool big_endian,
       while (!lsm.end_sequence)
         {
           size_t oplength;
-          bool add_line = this->process_one_opcode(size, big_endian,
+          bool add_line = this->process_one_opcode(lineptr, &lsm, &oplength);
-                                                   lineptr, &lsm, &oplength);
           if (add_line)
             {
               Offset_to_lineno_entry entry
@@ -446,12 +435,21 @@ Dwarf_line_info::read_lines(int size, bool big_endian,
   return lengthstart + header_.total_length;
 }
 
-// Called after all line numbers have been read.
+template<int size, bool big_endian>
-
 void
-Dwarf_line_info::finalize_line_number_map()
+Dwarf_line_info<size, big_endian>::read_line_mappings()
 {
-  for (Lineno_map::iterator it = line_number_map_.begin();
+  while (buffer_ < buffer_end_)
+    {
+      const unsigned char* lineptr = buffer_;
+      lineptr = this->read_header_prolog(lineptr);
+      lineptr = this->read_header_tables(lineptr);
+      lineptr = this->read_lines(lineptr);
+      buffer_ = lineptr;
+    }
+
+  // Sort the lines numbers, so addr2line can use binary search.
+  for (typename Lineno_map::iterator it = line_number_map_.begin();
        it != line_number_map_.end();
        ++it)
     // Each vector needs to be sorted by offset.
@@ -460,12 +458,13 @@ Dwarf_line_info::finalize_line_number_map()
 
 // Return a string for a file name and line number.
 
+template<int size, bool big_endian>
 std::string
-Dwarf_line_info::addr2line(unsigned int shndx, off_t offset)
+Dwarf_line_info<size, big_endian>::addr2line(unsigned int shndx, off_t offset)
 {
   const Offset_to_lineno_entry lookup_key = { offset, 0, 0 };
   std::vector<Offset_to_lineno_entry>& offsets = line_number_map_[shndx];
-  std::vector<Offset_to_lineno_entry>::const_iterator it
+  typename std::vector<Offset_to_lineno_entry>::const_iterator it
       = std::lower_bound(offsets.begin(), offsets.end(), lookup_key);
 
   // If we found an exact match, great, otherwise find the last entry
@@ -504,26 +503,22 @@ Dwarf_line_info::addr2line(unsigned int shndx, off_t offset)
 
 #ifdef HAVE_TARGET_32_LITTLE
 template
-const unsigned char*
+class Dwarf_line_info<32, false>;
-Dwarf_line_info::read_header_prolog<32, false>(const unsigned char* lineptr);
 #endif
 
 #ifdef HAVE_TARGET_32_BIG
 template
-const unsigned char*
+class Dwarf_line_info<32, true>;
-Dwarf_line_info::read_header_prolog<32, true>(const unsigned char* lineptr);
 #endif
 
 #ifdef HAVE_TARGET_64_LITTLE
 template
-const unsigned char*
+class Dwarf_line_info<64, false>;
-Dwarf_line_info::read_header_prolog<64, false>(const unsigned char* lineptr);
 #endif
 
 #ifdef HAVE_TARGET_64_BIG
 template
-const unsigned char*
+class Dwarf_line_info<64, true>;
-Dwarf_line_info::read_header_prolog<64, true>(const unsigned char* lineptr);
 #endif
 
 } // End namespace gold.

gold/dwarf_reader.h

@@ -36,6 +36,7 @@ struct LineStateMachine;
 // This class is used to read the line information from the debugging
 // section of an object file.
 
+template<int size, bool big_endian>
 class Dwarf_line_info
 {
  public:
@@ -49,20 +50,8 @@ class Dwarf_line_info
   { }
 
   // Start processing line info, and populates the offset_map_.
-  template<int size, bool big_endian>
   void
-  read_line_mappings()
+  read_line_mappings();
-  {
-    while (buffer_ < buffer_end_)
-      {
-        const unsigned char* lineptr = buffer_;
-        lineptr = this->read_header_prolog<size, big_endian>(lineptr);
-        lineptr = this->read_header_tables(lineptr);
-        lineptr = this->read_lines(size, big_endian, lineptr);
-        buffer_ = lineptr;
-      }
-    finalize_line_number_map();
-  }
 
   // Given a section number and an offset, returns the associated
   // file and line-number, as a string: "file:lineno".  If unable
@@ -74,7 +63,6 @@ class Dwarf_line_info
  private:
   // Reads the DWARF2/3 header for this line info.  Each takes as input
   // a starting buffer position, and returns the ending position.
-  template<int size, bool big_endian>
   const unsigned char*
   read_header_prolog(const unsigned char* lineptr);
 
@@ -83,22 +71,16 @@ class Dwarf_line_info
 
   // Reads the DWARF2/3 line information.
   const unsigned char*
-  read_lines(int size, bool big_endian, const unsigned char* lineptr);
+  read_lines(const unsigned char* lineptr);
 
   // Process a single line info opcode at START using the state
   // machine at LSM.  Return true if we should define a line using the
   // current state of the line state machine.  Place the length of the
   // opcode in LEN.
   bool
-  process_one_opcode(int size, bool big_endian,
+  process_one_opcode(const unsigned char* start,
-                     const unsigned char* start,
                      struct LineStateMachine* lsm, size_t* len);
 
-  // Called after all line number have been read, to ready
-  // line_number_map_ for calls to addr2line().
-  void
-  finalize_line_number_map();
-
   // A DWARF2/3 line info header.  This is not the same size as in the
   // actual file, as the one in the file may have a 32 bit or 64 bit
   // lengths.

gold/object.cc

@@ -919,8 +919,9 @@ Relocate_info<size, big_endian>::location(size_t, off_t offset) const
             shndx, &debuglines_size, false);
         if (debuglines)
           {
-            Dwarf_line_info line_info(debuglines, debuglines_size);
+            Dwarf_line_info<size, big_endian> line_info(debuglines,
-            line_info.read_line_mappings<size, big_endian>();
+							debuglines_size);
+            line_info.read_line_mappings();
             file_and_lineno = line_info.addr2line(this->data_shndx, offset);
           }
         break;