gdb: allocate symfile_segment_data with new

- Allocate this structure with new instead of XNEW, use a unique pointer
  to manage its lifetime.
- Change a few functions to return a unique   pointer instead of a
  plain pointer.
- Change free_symfile_segment_data to be symfile_segment_data's
  destructor.

gdb/ChangeLog:

	* symfile.h (struct symfile_segment_data): Initialize fields.
	<~symfile_segment_data>: Add.
	(symfile_segment_data_up): New.
	(struct sym_fns) <sym_segments>: Return a
	symfile_segment_data_up.
	(default_symfile_segments): Return a symfile_segment_data_up.
	(free_symfile_segment_data): Remove.
	(get_symfile_segment_data): Return a symfile_segment_data_up.
	* symfile.c (default_symfile_segments): Likewise.
	(get_symfile_segment_data): Likewise.
	(free_symfile_segment_data): Remove.
	(symfile_find_segment_sections): Update.
	* elfread.c (elf_symfile_segments): Return a
	symfile_segment_data_up.
	* remote.c (remote_target::get_offsets): Update.
	* solib-target.c (solib_target_relocate_section_addresses):
	Update.
	* symfile-debug.c (debug_sym_segments): Return a
	symfile_segment_data_up.

1 files changed, 3 insertions, 5 deletions

diff --git a/gdb/solib-target.c b/gdb/solib-target.c
index 93d95fd..35e50a3 100644
--- a/gdb/solib-target.c
+++ b/gdb/solib-target.c
@@ -364,9 +364,9 @@ Could not relocate shared library \"%s\": wrong number of ALLOC sections"),
 	}
       else if (!li->segment_bases.empty ())
 	{
-	  struct symfile_segment_data *data;
+	  symfile_segment_data_up data
+	    = get_symfile_segment_data (so->abfd);
 
-	  data = get_symfile_segment_data (so->abfd);
 	  if (data == NULL)
 	    warning (_("\
 Could not relocate shared library \"%s\": no segments"), so->so_name);
@@ -375,7 +375,7 @@ Could not relocate shared library \"%s\": no segments"), so->so_name);
 	      ULONGEST orig_delta;
 	      int i;
 
-	      if (!symfile_map_offsets_to_segments (so->abfd, data,
+	      if (!symfile_map_offsets_to_segments (so->abfd, data.get (),
 						    li->offsets,
 						    li->segment_bases.size (),
 						    li->segment_bases.data ()))
@@ -407,8 +407,6 @@ Could not relocate shared library \"%s\": bad offsets"), so->so_name);
 			       + data->segment_sizes[i - 1]
 			       + orig_delta);
 	      gdb_assert (so->addr_low <= so->addr_high);
-
-	      free_symfile_segment_data (data);
 	    }
 	}
     }