Don't call bfd_link_hash_table_free

Freeing the linker hash table is a royal pain.  It can't be freed
before the _bfd_write_contents call in bfd_close, because some target
bfd_write_contents functions access the hash table.  It can't be freed
after bfd_close either, since bfd_alloc memory holding side data
structures disappears (PR17047).  Clearly the only place it can be freed
is actually in bfd_close.  This patch doesn't do that, but kills off
the existing means of freeing the hash table via a bfd target xvec call.

bfd/
	PR 17047
	* targets.c (BFD_JUMP_TABLE): Delete NAME##_bfd_link_hash_table_free.
	(struct bfd_target <_bfd_link_hash_table_free>): Delete.
	* bfd.c (bfd_link_hash_table_free): Don't define.
	* aout-adobe.c, * aout-target.h, * aout-tic30.c, * binary.c, * bout.c,
	* coff64-rs6000.c, * coffcode.h, * elf-m10300.c, * elf32-arm.c,
	* elf32-avr.c, * elf32-hppa.c, * elf32-i386.c, * elf32-m68hc11.c,
	* elf32-m68hc12.c, * elf32-m68k.c, * elf32-metag.c, * elf32-nios2.c,
	* elf32-sparc.c, * elf32-xgate.c, * elf64-ia64-vms.c, * elf64-ppc.c,
	* elf64-sparc.c, * elf64-x86-64.c, * elfnn-aarch64.c, * elfnn-ia64.c,
	* elfxx-target.h, * i386msdos.c, * i386os9k.c, * ieee.c, * ihex.c,
	* libbfd-in.h, * libecoff.h, * mach-o-target.c, * mmo.c,
	* nlm-target.h, * oasys.c, * pef.c, * plugin.c, * ppcboot.c, * som.c,
	* srec.c, * tekhex.c, * verilog.c, * versados.c, * vms-alpha.c,
	* xsym.c: Don't define various link_hash_table_free defines, and
	remove from bfd_target vars.  Temporarily reference some of the
	target link_hash_table_free functions to avoid warnings.
	* bfd-in2.h: Regenerate.
	* libbfd.h: Regenerate.
ld/
	PR 17047
	* ldlang.c (output_bfd_hash_table_free_fn): Delete.
	(open_output): Don't set it..
	* ldmain.c (ld_cleanup): ..or call it.

3 files changed, 7 insertions, 19 deletions

diff --git a/ld/ChangeLog b/ld/ChangeLog
index e1abf43..783c4bd 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,5 +1,12 @@
 2014-06-13  Alan Modra  <amodra@gmail.com>
 
+	PR 17047
+	* ldlang.c (output_bfd_hash_table_free_fn): Delete.
+	(open_output): Don't set it..
+	* ldmain.c (ld_cleanup): ..or call it.
+
+2014-06-13  Alan Modra  <amodra@gmail.com>
+
 	* emultempl/cr16elf.em, * emultempl/elf32.em, * emultempl/genelf.em,
 	* emultempl/m68kcoff.em, * emultempl/m68kelf.em,
 	* emultempl/nds32elf.em, * emultempl/pe.em, * emultempl/pep.em,
diff --git a/ld/ldlang.c b/ld/ldlang.c
index add86da..e7c9669 100644
--- a/ld/ldlang.c
+++ b/ld/ldlang.c
@@ -3072,9 +3072,6 @@ lang_get_output_target (void)
   return default_target;
 }
 
-/* Stashed function to free link_info.hash; see open_output.  */
-void (*output_bfd_hash_table_free_fn) (struct bfd_link_hash_table *);
-
 /* Open the output file.  */
 
 static void
@@ -3154,18 +3151,6 @@ open_output (const char *name)
   if (link_info.hash == NULL)
     einfo (_("%P%F: can not create hash table: %E\n"));
 
-  /* We want to please memory leak checkers by deleting link_info.hash.
-     We can't do it in lang_finish, as a bfd target may hold references to
-     symbols in this table and use them when their _bfd_write_contents
-     function is invoked, as part of bfd_close on the output_bfd.  But,
-     output_bfd is deallocated at bfd_close, so we can't refer to
-     output_bfd after that time, and dereferencing it is needed to call
-     "bfd_link_hash_table_free".  Smash this dependency deadlock and grab
-     the function pointer; arrange to call it on link_info.hash in
-     ld_cleanup.  */
-  output_bfd_hash_table_free_fn
-    = link_info.output_bfd->xvec->_bfd_link_hash_table_free;
-
   bfd_set_gp_size (link_info.output_bfd, g_switch_value);
 }
 
diff --git a/ld/ldmain.c b/ld/ldmain.c
index d4be6f0..ea25afe 100644
--- a/ld/ldmain.c
+++ b/ld/ldmain.c
@@ -171,10 +171,6 @@ ld_cleanup (void)
 #endif
   if (output_filename && delete_output_file_on_failure)
     unlink_if_ordinary (output_filename);
-
-  /* See open_output in ldlang.c.  */
-  if (output_bfd_hash_table_free_fn != NULL)
-    (*output_bfd_hash_table_free_fn) (link_info.hash);
 }
 
 /* If there's a BFD assertion, we'll notice and exit with an error