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, 16 insertions, 8 deletions

diff --git a/gdb/symfile.h b/gdb/symfile.h
index 5ada6c3..2dfa655 100644
--- a/gdb/symfile.h
+++ b/gdb/symfile.h
@@ -80,26 +80,35 @@ typedef std::vector<other_sections> section_addr_info;
    each BFD section belongs to.  */
 struct symfile_segment_data
 {
+  ~symfile_segment_data ()
+  {
+    xfree (this->segment_bases);
+    xfree (this->segment_sizes);
+    xfree (this->segment_info);
+  }
+
   /* How many segments are present in this file.  If there are
      two, the text segment is the first one and the data segment
      is the second one.  */
-  int num_segments;
+  int num_segments = 0;
 
   /* If NUM_SEGMENTS is greater than zero, the original base address
      of each segment.  */
-  CORE_ADDR *segment_bases;
+  CORE_ADDR *segment_bases = nullptr;
 
   /* If NUM_SEGMENTS is greater than zero, the memory size of each
      segment.  */
-  CORE_ADDR *segment_sizes;
+  CORE_ADDR *segment_sizes = nullptr;
 
   /* If NUM_SEGMENTS is greater than zero, this is an array of entries
      recording which segment contains each BFD section.
      SEGMENT_INFO[I] is S+1 if the I'th BFD section belongs to segment
      S, or zero if it is not in any segment.  */
-  int *segment_info;
+  int *segment_info = nullptr;
 };
 
+using symfile_segment_data_up = std::unique_ptr<symfile_segment_data>;
+
 /* Callback for quick_symbol_functions->map_symbol_filenames.  */
 
 typedef void (symbol_filename_ftype) (const char *filename,
@@ -360,7 +369,7 @@ struct sym_fns
      the segments of ABFD.  Each segment is a unit of the file
      which may be relocated independently.  */
 
-  struct symfile_segment_data *(*sym_segments) (bfd *abfd);
+  symfile_segment_data_up (*sym_segments) (bfd *abfd);
 
   /* This function should read the linetable from the objfile when
      the line table cannot be read while processing the debugging
@@ -401,7 +410,7 @@ extern void default_symfile_offsets (struct objfile *objfile,
 /* The default version of sym_fns.sym_segments for readers that don't
    do anything special.  */
 
-extern struct symfile_segment_data *default_symfile_segments (bfd *abfd);
+extern symfile_segment_data_up default_symfile_segments (bfd *abfd);
 
 /* The default version of sym_fns.sym_relocate for readers that don't
    do anything special.  */
@@ -530,8 +539,7 @@ extern int symfile_map_offsets_to_segments (bfd *,
 					    const struct symfile_segment_data *,
 					    section_offsets &,
 					    int, const CORE_ADDR *);
-struct symfile_segment_data *get_symfile_segment_data (bfd *abfd);
-void free_symfile_segment_data (struct symfile_segment_data *data);
+symfile_segment_data_up get_symfile_segment_data (bfd *abfd);
 
 extern scoped_restore_tmpl<int> increment_reading_symtab (void);