[PATCHv2] gdb: change new_objfile observer to take an objfile reference

diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index eb4cd6d2f60..17a42568036 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -14059,9 +14059,9 @@  static struct cmd_list_element *show_ada_list;
 /* This module's 'new_objfile' observer.  */
 
 static void
-ada_new_objfile_observer (struct objfile *objfile)
+ada_new_objfile_observer (struct objfile &objfile)
 {
-  ada_clear_symbol_cache (objfile->pspace ());
+  ada_clear_symbol_cache (objfile.pspace ());
 }
 
 /* This module's 'free_objfile' observer.  */
diff --git a/gdb/ada-tasks.c b/gdb/ada-tasks.c
index 0e124e1a2a2..2a4d056caaf 100644
--- a/gdb/ada-tasks.c
+++ b/gdb/ada-tasks.c
@@ -1466,9 +1466,9 @@  ada_tasks_clear_pspace_data (program_space *pspace)
 /* Called when a new objfile was added.  */
 
 static void
-ada_tasks_new_objfile_observer (objfile *objfile)
+ada_tasks_new_objfile_observer (objfile &objfile)
 {
-  ada_tasks_clear_pspace_data (objfile->pspace ());
+  ada_tasks_clear_pspace_data (objfile.pspace ());
 }
 
 /* The qcs command line flags for the "task apply" commands.  Keep
diff --git a/gdb/agent.c b/gdb/agent.c
index beeaf62b552..4c8c237b3ae 100644
--- a/gdb/agent.c
+++ b/gdb/agent.c
@@ -62,7 +62,7 @@  set_can_use_agent (const char *args, int from_tty, struct cmd_list_element *c)
 }
 
 static void
-agent_new_objfile (struct objfile *objfile)
+agent_new_objfile (struct objfile &objfile)
 {
   if (agent_loaded_p ())
     return;
@@ -70,7 +70,7 @@  agent_new_objfile (struct objfile *objfile)
   if (can_use_agent == can_use_agent_off)
     return;
 
-  agent_look_up_symbols (objfile);
+  agent_look_up_symbols (&objfile);
 }
 
 INIT_GDB_FILE (agent)
diff --git a/gdb/aix-thread.c b/gdb/aix-thread.c
index 823fb13cb29..c2e6b6d2bd6 100644
--- a/gdb/aix-thread.c
+++ b/gdb/aix-thread.c
@@ -1011,7 +1011,7 @@  pd_disable (inferior *inf)
    for thread debugging.  */
 
 static void
-new_objfile (struct objfile *objfile)
+new_objfile (struct objfile &objfile)
 {
   pd_enable (current_inferior ());
 }
diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
index d7a9b469ef8..e887f6c1faf 100644
--- a/gdb/arm-tdep.c
+++ b/gdb/arm-tdep.c
@@ -2530,7 +2530,7 @@  arm_obj_section_from_vma (struct objfile *objfile, bfd_vma vma)
    retrieval by the arm_find_exidx_entry routine.  */
 
 static void
-arm_exidx_new_objfile (struct objfile *objfile)
+arm_exidx_new_objfile (struct objfile &objfile)
 {
   struct arm_exidx_data *data;
   asection *exidx, *extab;
@@ -2538,11 +2538,11 @@  arm_exidx_new_objfile (struct objfile *objfile)
   LONGEST i;
 
   /* If we've already touched this file, do nothing.  */
-  if (arm_exidx_data_key.get (objfile->obfd.get ()) != nullptr)
+  if (arm_exidx_data_key.get (objfile.obfd.get ()) != nullptr)
     return;
 
   /* Read contents of exception table and index.  */
-  exidx = bfd_get_section_by_name (objfile->obfd.get (),
+  exidx = bfd_get_section_by_name (objfile.obfd.get (),
 				   ELF_STRING_ARM_unwind);
   gdb::byte_vector exidx_data;
   if (exidx)
@@ -2550,35 +2550,35 @@  arm_exidx_new_objfile (struct objfile *objfile)
       exidx_vma = bfd_section_vma (exidx);
       exidx_data.resize (bfd_section_size (exidx));
 
-      if (!bfd_get_section_contents (objfile->obfd.get (), exidx,
+      if (!bfd_get_section_contents (objfile.obfd.get (), exidx,
 				     exidx_data.data (), 0,
 				     exidx_data.size ()))
 	return;
     }
 
-  extab = bfd_get_section_by_name (objfile->obfd.get (), ".ARM.extab");
+  extab = bfd_get_section_by_name (objfile.obfd.get (), ".ARM.extab");
   gdb::byte_vector extab_data;
   if (extab)
     {
       extab_vma = bfd_section_vma (extab);
       extab_data.resize (bfd_section_size (extab));
 
-      if (!bfd_get_section_contents (objfile->obfd.get (), extab,
+      if (!bfd_get_section_contents (objfile.obfd.get (), extab,
 				     extab_data.data (), 0,
 				     extab_data.size ()))
 	return;
     }
 
   /* Allocate exception table data structure.  */
-  data = &arm_exidx_data_key.emplace (objfile->obfd.get ());
-  data->section_maps.resize (objfile->obfd->section_count);
+  data = &arm_exidx_data_key.emplace (objfile.obfd.get ());
+  data->section_maps.resize (objfile.obfd->section_count);
 
   /* Fill in exception table.  */
   for (i = 0; i < exidx_data.size () / 8; i++)
     {
       struct arm_exidx_entry new_exidx_entry;
-      bfd_vma idx = bfd_h_get_32 (objfile->obfd, exidx_data.data () + i * 8);
-      bfd_vma val = bfd_h_get_32 (objfile->obfd,
+      bfd_vma idx = bfd_h_get_32 (objfile.obfd, exidx_data.data () + i * 8);
+      bfd_vma val = bfd_h_get_32 (objfile.obfd,
 				  exidx_data.data () + i * 8 + 4);
       bfd_vma addr = 0, word = 0;
       int n_bytes = 0, n_words = 0;
@@ -2590,7 +2590,7 @@  arm_exidx_new_objfile (struct objfile *objfile)
       idx += exidx_vma + i * 8;
 
       /* Find section containing function and compute section offset.  */
-      sec = arm_obj_section_from_vma (objfile, idx);
+      sec = arm_obj_section_from_vma (&objfile, idx);
       if (sec == NULL)
 	continue;
       idx -= bfd_section_vma (sec->the_bfd_section);
@@ -2615,7 +2615,7 @@  arm_exidx_new_objfile (struct objfile *objfile)
 
 	  if (addr >= extab_vma && addr + 4 <= extab_vma + extab_data.size ())
 	    {
-	      word = bfd_h_get_32 (objfile->obfd,
+	      word = bfd_h_get_32 (objfile.obfd,
 				   extab_data.data () + addr - extab_vma);
 	      addr += 4;
 
@@ -2643,7 +2643,7 @@  arm_exidx_new_objfile (struct objfile *objfile)
 
 		  /* Check whether we've got one of the variants of the
 		     GNU personality routines.  */
-		  pers_sec = arm_obj_section_from_vma (objfile, pers);
+		  pers_sec = arm_obj_section_from_vma (&objfile, pers);
 		  if (pers_sec)
 		    {
 		      static const char *personality[] =
@@ -2660,7 +2660,7 @@  arm_exidx_new_objfile (struct objfile *objfile)
 
 		      for (k = 0; personality[k]; k++)
 			if (lookup_minimal_symbol_by_pc_name
-			      (pc, personality[k], objfile))
+			      (pc, personality[k], &objfile))
 			  {
 			    gnu_personality = 1;
 			    break;
@@ -2673,7 +2673,7 @@  arm_exidx_new_objfile (struct objfile *objfile)
 		  if (gnu_personality
 		      && addr + 4 <= extab_vma + extab_data.size ())
 		    {
-		      word = bfd_h_get_32 (objfile->obfd,
+		      word = bfd_h_get_32 (objfile.obfd,
 					   (extab_data.data ()
 					    + addr - extab_vma));
 		      addr += 4;
@@ -2696,7 +2696,7 @@  arm_exidx_new_objfile (struct objfile *objfile)
       if (n_bytes || n_words)
 	{
 	  gdb_byte *p = entry
-	    = (gdb_byte *) obstack_alloc (&objfile->per_bfd->storage_obstack,
+	    = (gdb_byte *) obstack_alloc (&objfile.per_bfd->storage_obstack,
 					  n_bytes + n_words * 4 + 1);
 
 	  while (n_bytes--)
@@ -2704,7 +2704,7 @@  arm_exidx_new_objfile (struct objfile *objfile)
 
 	  while (n_words--)
 	    {
-	      word = bfd_h_get_32 (objfile->obfd,
+	      word = bfd_h_get_32 (objfile.obfd,
 				   extab_data.data () + addr - extab_vma);
 	      addr += 4;
 
diff --git a/gdb/auto-load.c b/gdb/auto-load.c
index b5fec13743c..9e1aac95c05 100644
--- a/gdb/auto-load.c
+++ b/gdb/auto-load.c
@@ -1199,23 +1199,23 @@  auto_load_section_scripts (struct objfile *objfile, const char *section_name)
    2) from .debug_gdb_scripts section  */
 
 void
-load_auto_scripts_for_objfile (struct objfile *objfile)
+load_auto_scripts_for_objfile (struct objfile &objfile)
 {
   /* Return immediately if auto-loading has been globally disabled.
      This is to handle sequencing of operations during gdb startup.
      Also return immediately if OBJFILE was not created from a file
      on the local filesystem.  */
   if (!global_auto_load
-      || (objfile->flags & OBJF_NOT_FILENAME) != 0
-      || is_target_filename (objfile->original_name))
+      || (objfile.flags & OBJF_NOT_FILENAME) != 0
+      || is_target_filename (objfile.original_name))
     return;
 
   /* Load any extension language scripts for this objfile.
      E.g., foo-gdb.gdb, foo-gdb.py.  */
-  auto_load_ext_lang_scripts_for_objfile (objfile);
+  auto_load_ext_lang_scripts_for_objfile (&objfile);
 
   /* Load any scripts mentioned in AUTO_SECTION_NAME (.debug_gdb_scripts).  */
-  auto_load_section_scripts (objfile, AUTO_SECTION_NAME);
+  auto_load_section_scripts (&objfile, AUTO_SECTION_NAME);
 }
 
 /* Collect scripts to be printed in a vec.  */
diff --git a/gdb/auto-load.h b/gdb/auto-load.h
index 35c7b31f0fd..d03c8493df0 100644
--- a/gdb/auto-load.h
+++ b/gdb/auto-load.h
@@ -54,7 +54,7 @@  extern struct auto_load_pspace_info *
   get_auto_load_pspace_data_for_loading (struct program_space *pspace);
 extern void auto_load_objfile_script (struct objfile *objfile,
 				      const struct extension_language_defn *);
-extern void load_auto_scripts_for_objfile (struct objfile *objfile);
+extern void load_auto_scripts_for_objfile (struct objfile &objfile);
 extern char auto_load_info_scripts_pattern_nl[];
 extern void auto_load_info_scripts (program_space *pspace, const char *pattern,
 				    int from_tty,
diff --git a/gdb/linux-thread-db.c b/gdb/linux-thread-db.c
index bd45a2f2978..3107fd44355 100644
--- a/gdb/linux-thread-db.c
+++ b/gdb/linux-thread-db.c
@@ -1269,7 +1269,7 @@  check_for_thread_db (void)
 /* This function is called via the new_objfile observer.  */
 
 static void
-thread_db_new_objfile (struct objfile *objfile)
+thread_db_new_objfile (struct objfile &objfile)
 {
   /* This observer must always be called with inferior_ptid set
      correctly.  */
@@ -1279,7 +1279,7 @@  thread_db_new_objfile (struct objfile *objfile)
 	 the time gdb::observers::new_objfile.notify is called for the library itself.
 	 Static executables have their separate debug info loaded already
 	 before the inferior has started.  */
-      objfile->separate_debug_objfile_backlink == NULL
+      objfile.separate_debug_objfile_backlink == NULL
       /* Only check for thread_db if we loaded libpthread,
 	 or if this is the main symbol file.
 	 We need to check OBJF_MAINLINE to handle the case of debugging
@@ -1288,8 +1288,8 @@  thread_db_new_objfile (struct objfile *objfile)
 	 For dynamically linked executables, libpthread can be near the end
 	 of the list of shared libraries to load, and in an app of several
 	 thousand shared libraries, this can otherwise be painful.  */
-      && ((objfile->flags & OBJF_MAINLINE) != 0
-	  || libpthread_objfile_p (objfile)))
+      && ((objfile.flags & OBJF_MAINLINE) != 0
+	  || libpthread_objfile_p (&objfile)))
     check_for_thread_db ();
 }
 
diff --git a/gdb/main.c b/gdb/main.c
index a4e6cddef70..e7379693997 100644
--- a/gdb/main.c
+++ b/gdb/main.c
@@ -1336,7 +1336,7 @@  captured_main_1 (struct captured_main_args *context)
      path in local_gdbinit.  */
   global_auto_load = save_auto_load;
   for (objfile &objfile : current_program_space->objfiles ())
-    load_auto_scripts_for_objfile (&objfile);
+    load_auto_scripts_for_objfile (objfile);
 
   /* Process '-x' and '-ex' options.  */
   execute_cmdargs (&cmdarg_vec, CMDARG_FILE, CMDARG_COMMAND, &ret);
diff --git a/gdb/observable.h b/gdb/observable.h
index 89877950a3c..9f1c33ba710 100644
--- a/gdb/observable.h
+++ b/gdb/observable.h
@@ -112,7 +112,7 @@  extern observable<program_space *, const solib &/* solib */,
 		  bool /* still_in_use */, bool /* silent */> solib_unloaded;
 
 /* The symbol file specified by OBJFILE has been loaded.  */
-extern observable<struct objfile */* objfile */> new_objfile;
+extern observable<struct objfile &/* objfile */> new_objfile;
 
 /*  All objfiles from PSPACE were removed.  */
 extern observable<program_space */* pspace */> all_objfiles_removed;
diff --git a/gdb/python/py-inferior.c b/gdb/python/py-inferior.c
index 76e3da9f620..ca1da5536b0 100644
--- a/gdb/python/py-inferior.c
+++ b/gdb/python/py-inferior.c
@@ -163,19 +163,18 @@  python_inferior_exit (struct inferior *inf)
     gdbpy_print_stack ();
 }
 
-/* Callback used to notify Python listeners about new objfiles loaded in the
-   inferior.  OBJFILE may be NULL which means that the objfile list has been
-   cleared (emptied).  */
+/* Callback used to notify Python listeners that OBJFILE has been loaded in
+   to the current inferior.  */
 
 static void
-python_new_objfile (struct objfile *objfile)
+python_new_objfile (struct objfile &objfile)
 {
   if (!gdb_python_initialized)
     return;
 
-  gdbpy_enter enter_py (objfile->arch ());
+  gdbpy_enter enter_py (objfile.arch ());
 
-  if (emit_new_objfile_event (objfile) < 0)
+  if (emit_new_objfile_event (&objfile) < 0)
     gdbpy_print_stack ();
 }
 
diff --git a/gdb/remote.c b/gdb/remote.c
index 88b06e688bc..6f87b928bd0 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -16226,9 +16226,9 @@  remote_objfile_changed_check_symbols (program_space *pspace)
 /* Function to be called whenever a new objfile (shlib) is detected.  */
 
 static void
-remote_new_objfile (struct objfile *objfile)
+remote_new_objfile (struct objfile &objfile)
 {
-  remote_objfile_changed_check_symbols (objfile->pspace ());
+  remote_objfile_changed_check_symbols (objfile.pspace ());
 }
 
 /* Pull all the tracepoints defined on the target and create local
diff --git a/gdb/sol-thread.c b/gdb/sol-thread.c
index 066aa41c152..ec480186b59 100644
--- a/gdb/sol-thread.c
+++ b/gdb/sol-thread.c
@@ -666,7 +666,7 @@  check_for_thread_db (void)
    the library gets mapped and the symbol table is read in.  */
 
 static void
-sol_thread_new_objfile (struct objfile *objfile)
+sol_thread_new_objfile (struct objfile &objfile)
 {
   check_for_thread_db ();
 }
diff --git a/gdb/symfile.c b/gdb/symfile.c
index 44a9480d9d9..5e9054759c1 100644
--- a/gdb/symfile.c
+++ b/gdb/symfile.c
@@ -1102,7 +1102,7 @@  symbol_file_add_with_addrs (const gdb_bfd_ref_ptr &abfd, const char *name,
   if (objfile->sf != nullptr)
     finish_new_objfile (objfile, add_flags);
 
-  gdb::observers::new_objfile.notify (objfile);
+  gdb::observers::new_objfile.notify (*objfile);
 
   return objfile;
 }
@@ -2662,11 +2662,11 @@  reread_symbols (int from_tty)
     {
       clear_symtab_users (0);
 
-      /* The registry for each objfile was cleared and
-	 gdb::observers::new_objfile.notify (NULL) has been called by
+      /* The registry for each objfile was cleared and the
+	 all_objfiles_removed observer was notified by the call to
 	 clear_symtab_users above.  Notify the new files now.  */
       for (auto iter : new_objfiles)
-	gdb::observers::new_objfile.notify (iter);
+	gdb::observers::new_objfile.notify (*iter);
     }
 }
 
diff --git a/gdb/symtab.c b/gdb/symtab.c
index cd3bf876551..e71e5d78e7c 100644
--- a/gdb/symtab.c
+++ b/gdb/symtab.c
@@ -1698,9 +1698,9 @@  maintenance_print_symbol_cache_statistics (const char *args, int from_tty)
 /* This module's 'new_objfile' observer.  */
 
 static void
-symtab_new_objfile_observer (struct objfile *objfile)
+symtab_new_objfile_observer (struct objfile &objfile)
 {
-  symbol_cache_flush (objfile->pspace ());
+  symbol_cache_flush (objfile.pspace ());
 }
 
 /* This module's 'all_objfiles_removed' observer.  */
diff --git a/gdb/tui/tui-hooks.c b/gdb/tui/tui-hooks.c
index dff0eeca118..17ae8e7a590 100644
--- a/gdb/tui/tui-hooks.c
+++ b/gdb/tui/tui-hooks.c
@@ -38,7 +38,7 @@ 
 #include "tui/tui-wingeneral.h"
 
 static void
-tui_new_objfile_hook (struct objfile* objfile)
+tui_new_objfile_hook (struct objfile &objfile)
 {
   if (tui_active)
     tui_display_main ();