Support compressed debug sections in dynamic object files.

This patch adds support for reading compressed debug info in
shared objects. It actually simplifies things, by moving the
support for compressed sections all the way up to the top-level
Object class, eliminating the need for several virtual methods.

gold/
	* dwp.cc (Sized_relobj_dwo::do_section_contents): Delete.
	(Sized_relobj_dwo::setup): Build compressed section map.
	(Sized_relobj_dwo::do_decompressed_section_contents): Delete.
	* dynobj.cc (Sized_dynobj::base_read_symbols): Build compressed
	section map.
	* object.cc (Sized_relobj_file::Sized_relobj_file): Remove
	compressed_sections_ field.
	(build_compressed_section_map): Take Object instead of
	Sized_relobj_file parameter; add decompress_if_needed parameter.
	(Sized_relobj_file::do_find_special_sections): Store compressed
	section map in parent Object.
	(Sized_relobj_file::do_decompressed_section_contents): Move
	implementation to Object::decompressed_section_contents.
	(Sized_relobj_file::do_discard_decompressed_sections): Move
	implementation to Object::discard_decompressed_sections.
	* object.h (build_compressed_section_map): Declare.
	(Object::Object): Add compressed_sections_ field.
	(Object::section_is_compressed): Move implementation here.
	(Object::decompressed_section_contents): De-virtualize.
	(Object::discard_decompressed_sections): De-virtualize.
	(Object::do_section_is_compressed): Delete.
	(Object::do_decompressed_section_contents): Delete.
	(Object::set_compressed_sections): New method.
	(Object::compressed_sections): New method.
	(Object::compressed_sections_): New data member.
	(Compressed_section_info, Compressed_section_map): Move to top of file.
	(Sized_relobj_file::do_section_is_compressed): Delete.
	(Sized_relobj_file::do_decompressed_section_contents): Delete.
	(Sized_relobj_file::do_discard_decompressed_sections): Delete.
	(Sized_relobj_file::compressed_sections_): Move to Object class.

1 files changed, 14 insertions, 11 deletions

diff --git a/gold/object.cc b/gold/object.cc
index 84e4568..f983b66 100644
--- a/gold/object.cc
+++ b/gold/object.cc
@@ -477,8 +477,7 @@ Sized_relobj_file<size, big_endian>::Sized_relobj_file(
     discarded_eh_frame_shndx_(-1U),
     is_deferred_layout_(false),
     deferred_layout_(),
-    deferred_layout_relocs_(),
-    compressed_sections_()
+    deferred_layout_relocs_()
 {
   this->e_type_ = ehdr.get_e_type();
 }
@@ -720,7 +719,8 @@ build_compressed_section_map(
     unsigned int shnum,
     const char* names,
     section_size_type names_size,
-    Sized_relobj_file<size, big_endian>* obj)
+    Object* obj,
+    bool decompress_if_needed)
 {
   Compressed_section_map* uncompressed_map = new Compressed_section_map();
   const unsigned int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
@@ -752,7 +752,7 @@ build_compressed_section_map(
 	      if (uncompressed_size != -1ULL)
 		{
 		  unsigned char* uncompressed_data = NULL;
-		  if (need_decompressed_section(name))
+		  if (decompress_if_needed && need_decompressed_section(name))
 		    {
 		      uncompressed_data = new unsigned char[uncompressed_size];
 		      if (decompress_input_section(contents, len,
@@ -786,9 +786,14 @@ Sized_relobj_file<size, big_endian>::do_find_special_sections(
     this->has_eh_frame_ = true;
 
   if (memmem(names, sd->section_names_size, ".zdebug_", 8) != NULL)
-    this->compressed_sections_
-      = build_compressed_section_map(pshdrs, this->shnum(), names,
-				     sd->section_names_size, this);
+    {
+      Compressed_section_map* compressed_sections =
+	  build_compressed_section_map<size, big_endian>(
+	      pshdrs, this->shnum(), names, sd->section_names_size, this, true);
+      if (compressed_sections != NULL)
+        this->set_compressed_sections(compressed_sections);
+    }
+
   return (this->has_eh_frame_
 	  || (!parameters->options().relocatable()
 	      && parameters->options().gdb_index()
@@ -2849,9 +2854,8 @@ Sized_relobj_file<size, big_endian>::do_get_global_symbol_counts(
 // to the size.  Set *IS_NEW to true if the contents need to be freed
 // by the caller.
 
-template<int size, bool big_endian>
 const unsigned char*
-Sized_relobj_file<size, big_endian>::do_decompressed_section_contents(
+Object::decompressed_section_contents(
     unsigned int shndx,
     section_size_type* plen,
     bool* is_new)
@@ -2905,9 +2909,8 @@ Sized_relobj_file<size, big_endian>::do_decompressed_section_contents(
 // Discard any buffers of uncompressed sections.  This is done
 // at the end of the Add_symbols task.
 
-template<int size, bool big_endian>
 void
-Sized_relobj_file<size, big_endian>::do_discard_decompressed_sections()
+Object::discard_decompressed_sections()
 {
   if (this->compressed_sections_ == NULL)
     return;