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, 2 insertions, 3 deletions

diff --git a/gdb/elfread.c b/gdb/elfread.c
index 2f2fef9..4804d62 100644
--- a/gdb/elfread.c
+++ b/gdb/elfread.c
@@ -85,14 +85,13 @@ static const struct bfd_key<elfread_data> probe_key;
 
 /* Locate the segments in ABFD.  */
 
-static struct symfile_segment_data *
+static symfile_segment_data_up
 elf_symfile_segments (bfd *abfd)
 {
   Elf_Internal_Phdr *phdrs, **segments;
   long phdrs_size;
   int num_phdrs, num_segments, num_sections, i;
   asection *sect;
-  struct symfile_segment_data *data;
 
   phdrs_size = bfd_get_elf_phdr_upper_bound (abfd);
   if (phdrs_size == -1)
@@ -112,7 +111,7 @@ elf_symfile_segments (bfd *abfd)
   if (num_segments == 0)
     return NULL;
 
-  data = XCNEW (struct symfile_segment_data);
+  symfile_segment_data_up data (new symfile_segment_data);
   data->num_segments = num_segments;
   data->segment_bases = XCNEWVEC (CORE_ADDR, num_segments);
   data->segment_sizes = XCNEWVEC (CORE_ADDR, num_segments);