Use class to manage BFD reference counts

This introduces a new specialization of gdb::ref_ptr that can be used
to manage BFD reference counts.  Then it changes most places in gdb to
use this new class, rather than explicit reference-counting or
cleanups.  This patch removes make_cleanup_bfd_unref.

If you look you will see a couple of spots using "release" where a use
of gdb_bfd_ref_ptr would be cleaner.  These will be fixed in the next
patch.

I think this patch fixes some latent bugs.  For example, it seems to
me that previously objfpy_add_separate_debug_file leaked a BFD.

I'm not 100% certain that the macho_symfile_read_all_oso change is
correct.  The existing code here is hard for me to follow.  One goal
of this sort of automated reference counting, though, is to make it
more difficult to make logic errors; so hopefully the code is clear
now.

2017-01-10  Tom Tromey  <tom@tromey.com>

	* windows-tdep.c (windows_xfer_shared_library): Update.
	* windows-nat.c (windows_make_so): Update.
	* utils.h (make_cleanup_bfd_unref): Remove.
	* utils.c (do_bfd_close_cleanup, make_cleanup_bfd_unref): Remove.
	* symfile.h (symfile_bfd_open)
	(find_separate_debug_file_in_section): Return gdb_bfd_ref_ptr.
	* symfile.c (read_symbols, symbol_file_add)
	(separate_debug_file_exists): Update.
	(symfile_bfd_open): Return gdb_bfd_ref_ptr.
	(generic_load, reread_symbols): Update.
	* symfile-mem.c (symbol_file_add_from_memory): Update.
	* spu-linux-nat.c (spu_bfd_open): Return gdb_bfd_ref_ptr.
	(spu_symbol_file_add_from_memory): Update.
	* solist.h (struct target_so_ops) <bfd_open>: Return
	gdb_bfd_ref_ptr.
	(solib_bfd_fopen, solib_bfd_open): Return gdb_bfd_ref_ptr.
	* solib.c (solib_bfd_fopen, solib_bfd_open): Return
	gdb_bfd_ref_ptr.
	(solib_map_sections, reload_shared_libraries_1): Update.
	* solib-svr4.c (enable_break): Update.
	* solib-spu.c (spu_bfd_fopen): Return gdb_bfd_ref_ptr.
	* solib-frv.c (enable_break2): Update.
	* solib-dsbt.c (enable_break): Update.
	* solib-darwin.c (gdb_bfd_mach_o_fat_extract): Return
	gdb_bfd_ref_ptr.
	(darwin_solib_get_all_image_info_addr_at_init): Update.
	(darwin_bfd_open): Return gdb_bfd_ref_ptr.
	* solib-aix.c (solib_aix_bfd_open): Return gdb_bfd_ref_ptr.
	* record-full.c (record_full_save): Update.
	* python/py-objfile.c (objfpy_add_separate_debug_file): Update.
	* procfs.c (insert_dbx_link_bpt_in_file): Update.
	* minidebug.c (find_separate_debug_file_in_section): Return
	gdb_bfd_ref_ptr.
	* machoread.c (macho_add_oso_symfile): Change abfd to
	gdb_bfd_ref_ptr.
	(macho_symfile_read_all_oso): Update.
	(macho_check_dsym): Return gdb_bfd_ref_ptr.
	(macho_symfile_read): Update.
	* jit.c (bfd_open_from_target_memory): Return gdb_bfd_ref_ptr.
	(jit_bfd_try_read_symtab): Update.
	* gdb_bfd.h (gdb_bfd_open, gdb_bfd_fopen, gdb_bfd_openr)
	(gdb_bfd_openw, gdb_bfd_openr_iovec)
	(gdb_bfd_openr_next_archived_file, gdb_bfd_fdopenr): Return
	gdb_bfd_ref_ptr.
	(gdb_bfd_ref_policy): New struct.
	(gdb_bfd_ref_ptr): New typedef.
	* gdb_bfd.c (gdb_bfd_open, gdb_bfd_fopen, gdb_bfd_openr)
	(gdb_bfd_openw, gdb_bfd_openr_iovec)
	(gdb_bfd_openr_next_archived_file, gdb_bfd_fdopenr): Return
	gdb_bfd_ref_ptr.
	* gcore.h (create_gcore_bfd): Return gdb_bfd_ref_ptr.
	* gcore.c (create_gcore_bfd): Return gdb_bfd_ref_ptr.
	(gcore_command): Update.
	* exec.c (exec_file_attach): Update.
	* elfread.c (elf_symfile_read): Update.
	* dwarf2read.c (dwarf2_get_dwz_file): Update.
	(try_open_dwop_file, open_dwo_file): Return gdb_bfd_ref_ptr.
	(open_and_init_dwo_file): Update.
	(open_dwp_file): Return gdb_bfd_ref_ptr.
	(open_and_init_dwp_file): Update.
	* corelow.c (core_open): Update.
	* compile/compile-object-load.c (compile_object_load): Update.
	* common/gdb_ref_ptr.h (ref_ptr::operator->): New operator.
	* coffread.c (coff_symfile_read): Update.
	* cli/cli-dump.c (bfd_openr_or_error, bfd_openw_or_error): Return
	gdb_bfd_ref_ptr.  Rename.
	(dump_bfd_file, restore_command): Update.
	* build-id.h (build_id_to_debug_bfd): Return gdb_bfd_ref_ptr.
	* build-id.c (build_id_to_debug_bfd): Return gdb_bfd_ref_ptr.
	(find_separate_debug_file_by_buildid): Update.

1 files changed, 15 insertions, 15 deletions

diff --git a/gdb/gdb_bfd.c b/gdb/gdb_bfd.c
index 58f4012..37cf6e2 100644
--- a/gdb/gdb_bfd.c
+++ b/gdb/gdb_bfd.c
@@ -356,7 +356,7 @@ gdb_bfd_iovec_fileio_fstat (struct bfd *abfd, void *stream,
 
 /* See gdb_bfd.h.  */
 
-struct bfd *
+gdb_bfd_ref_ptr
 gdb_bfd_open (const char *name, const char *target, int fd)
 {
   hashval_t hash;
@@ -428,7 +428,7 @@ gdb_bfd_open (const char *name, const char *target, int fd)
 			    bfd_get_filename (abfd));
       close (fd);
       gdb_bfd_ref (abfd);
-      return abfd;
+      return gdb_bfd_ref_ptr (abfd);
     }
 
   abfd = bfd_fopen (name, target, FOPEN_RB, fd);
@@ -449,7 +449,7 @@ gdb_bfd_open (const char *name, const char *target, int fd)
     }
 
   gdb_bfd_ref (abfd);
-  return abfd;
+  return gdb_bfd_ref_ptr (abfd);
 }
 
 /* A helper function that releases any section data attached to the
@@ -772,7 +772,7 @@ gdb_bfd_crc (struct bfd *abfd, unsigned long *crc_out)
 
 /* See gdb_bfd.h.  */
 
-bfd *
+gdb_bfd_ref_ptr
 gdb_bfd_fopen (const char *filename, const char *target, const char *mode,
 	       int fd)
 {
@@ -781,12 +781,12 @@ gdb_bfd_fopen (const char *filename, const char *target, const char *mode,
   if (result)
     gdb_bfd_ref (result);
 
-  return result;
+  return gdb_bfd_ref_ptr (result);
 }
 
 /* See gdb_bfd.h.  */
 
-bfd *
+gdb_bfd_ref_ptr
 gdb_bfd_openr (const char *filename, const char *target)
 {
   bfd *result = bfd_openr (filename, target);
@@ -794,12 +794,12 @@ gdb_bfd_openr (const char *filename, const char *target)
   if (result)
     gdb_bfd_ref (result);
 
-  return result;
+  return gdb_bfd_ref_ptr (result);
 }
 
 /* See gdb_bfd.h.  */
 
-bfd *
+gdb_bfd_ref_ptr
 gdb_bfd_openw (const char *filename, const char *target)
 {
   bfd *result = bfd_openw (filename, target);
@@ -807,12 +807,12 @@ gdb_bfd_openw (const char *filename, const char *target)
   if (result)
     gdb_bfd_ref (result);
 
-  return result;
+  return gdb_bfd_ref_ptr (result);
 }
 
 /* See gdb_bfd.h.  */
 
-bfd *
+gdb_bfd_ref_ptr
 gdb_bfd_openr_iovec (const char *filename, const char *target,
 		     void *(*open_func) (struct bfd *nbfd,
 					 void *open_closure),
@@ -835,7 +835,7 @@ gdb_bfd_openr_iovec (const char *filename, const char *target,
   if (result)
     gdb_bfd_ref (result);
 
-  return result;
+  return gdb_bfd_ref_ptr (result);
 }
 
 /* See gdb_bfd.h.  */
@@ -861,7 +861,7 @@ gdb_bfd_mark_parent (bfd *child, bfd *parent)
 
 /* See gdb_bfd.h.  */
 
-bfd *
+gdb_bfd_ref_ptr
 gdb_bfd_openr_next_archived_file (bfd *archive, bfd *previous)
 {
   bfd *result = bfd_openr_next_archived_file (archive, previous);
@@ -869,7 +869,7 @@ gdb_bfd_openr_next_archived_file (bfd *archive, bfd *previous)
   if (result)
     gdb_bfd_mark_parent (result, archive);
 
-  return result;
+  return gdb_bfd_ref_ptr (result);
 }
 
 /* See gdb_bfd.h.  */
@@ -886,7 +886,7 @@ gdb_bfd_record_inclusion (bfd *includer, bfd *includee)
 
 /* See gdb_bfd.h.  */
 
-bfd *
+gdb_bfd_ref_ptr
 gdb_bfd_fdopenr (const char *filename, const char *target, int fd)
 {
   bfd *result = bfd_fdopenr (filename, target, fd);
@@ -894,7 +894,7 @@ gdb_bfd_fdopenr (const char *filename, const char *target, int fd)
   if (result)
     gdb_bfd_ref (result);
 
-  return result;
+  return gdb_bfd_ref_ptr (result);
 }