[patch 3/7] [gold] Add set_abbrev_shndx for use when there are no relocations and the .debug_abbrev section is known.

[Cary Coutant <ccoutant at google dot com>]

This patch modifies the dwarf reader to allow a known abbrev section
index to be provided.  This is necessary because the .dwo files we're
reading don't have any relocations, and may have multiple abbrev
sections.

gold/
	* dwarf_reader.cc (Dwarf_info_reader::do_parse): Use stored
	abbrev_shndx.
	* dwarf_reader.h (Dwarf_info_reader::Dwarf_info_reader): Initialize
	abbrev_shndx_.
	(Dwarf_info_reader::set_abbrev_shndx): New method.
	(Dwarf_info_reader::abbrev_shndx_): New data member.
---
 gold/dwarf_reader.cc |    2 +-
 gold/dwarf_reader.h  |   21 +++++++++++++++------
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/gold/dwarf_reader.cc b/gold/dwarf_reader.cc
index d0f059d..14222c5 100644
--- a/gold/dwarf_reader.cc
+++ b/gold/dwarf_reader.cc
@@ -1195,7 +1195,7 @@ Dwarf_info_reader::do_parse()
   this->reloc_mapper_->initialize(this->reloc_shndx_, this->reloc_type_);
 
   // Loop over compilation units (or type units).
-  unsigned int abbrev_shndx = 0;
+  unsigned int abbrev_shndx = this->abbrev_shndx_;
   off_t abbrev_offset = 0;
   const unsigned char* pinfo = this->buffer_;
   while (pinfo < this->buffer_end_)
diff --git a/gold/dwarf_reader.h b/gold/dwarf_reader.h
index de5722b..aea63ab 100644
--- a/gold/dwarf_reader.h
+++ b/gold/dwarf_reader.h
@@ -662,12 +662,12 @@ class Dwarf_info_reader
 		    unsigned int reloc_type)
     : is_type_unit_(is_type_unit), object_(object), symtab_(symtab),
       symtab_size_(symtab_size), shndx_(shndx), reloc_shndx_(reloc_shndx),
-      reloc_type_(reloc_type), string_shndx_(0), buffer_(NULL),
-      buffer_end_(NULL), cu_offset_(0), cu_length_(0), offset_size_(0),
-      address_size_(0), cu_version_(0), type_signature_(0), type_offset_(0),
-      abbrev_table_(), reloc_mapper_(NULL), string_buffer_(NULL),
-      string_buffer_end_(NULL), owns_string_buffer_(false),
-      string_output_section_offset_(0)
+      reloc_type_(reloc_type), abbrev_shndx_(0), string_shndx_(0),
+      buffer_(NULL), buffer_end_(NULL), cu_offset_(0), cu_length_(0),
+      offset_size_(0), address_size_(0), cu_version_(0), type_signature_(0),
+      type_offset_(0), abbrev_table_(), reloc_mapper_(NULL),
+      string_buffer_(NULL), string_buffer_end_(NULL),
+      owns_string_buffer_(false), string_output_section_offset_(0)
   { }
 
   virtual
@@ -719,6 +719,13 @@ class Dwarf_info_reader
   address_size() const
   { return this->address_size_; }
 
+  // Set the section index of the .debug_abbrev section.
+  // We use this if there are no relocations for the .debug_info section.
+  // If not set, the code parse() routine will search for the section by name.
+  void
+  set_abbrev_shndx(unsigned int abbrev_shndx)
+  { this->abbrev_shndx_ = abbrev_shndx; }
+
  protected:
   // Begin parsing the debug info.  This calls visit_compilation_unit()
   // or visit_type_unit() for each compilation or type unit found in the
@@ -811,6 +818,8 @@ class Dwarf_info_reader
   unsigned int reloc_shndx_;
   // Type of the relocation section (SHT_REL or SHT_RELA).
   unsigned int reloc_type_;
+  // Index of the .debug_abbrev section (0 if not known).
+  unsigned int abbrev_shndx_;
   // Index of the .debug_str section.
   unsigned int string_shndx_;
   // The buffer for the debug info.
-- 
1.7.9.6 (Apple Git-31.1)