[RFA] Make dwarf2_free_objfile static

[Tom Tromey <tom at tromey dot com>]

I noticed that dwarf2_free_objfile can be made static, by changing it
to be a registry cleanup function.  This simplifies the code, as well,
because now symbol readers don't have to explicitly call it.

Tested by the buildbot.

gdb/ChangeLog
2018-06-05  Tom Tromey  <tom@tromey.com>

	* coffread.c (coff_symfile_finish): Update.
	* xcoffread.c (xcoff_symfile_finish): Update.
	* elfread.c (elf_symfile_finish): Update.
	* symfile.h (dwarf2_free_objfile): Don't declare.
	* dwarf2read.c (_initialize_dwarf2_read): Use
	register_objfile_data_with_cleanup.
	(dwarf2_free_objfile): Now static.  Change signature.
---
 gdb/ChangeLog    | 10 ++++++++++
 gdb/coffread.c   |  2 --
 gdb/dwarf2read.c | 12 ++++++------
 gdb/elfread.c    |  1 -
 gdb/symfile.h    |  2 --
 gdb/xcoffread.c  |  2 --
 6 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/gdb/coffread.c b/gdb/coffread.c
index bc266fb60e3..30583e1dda4 100644
--- a/gdb/coffread.c
+++ b/gdb/coffread.c
@@ -766,8 +766,6 @@ coff_symfile_finish (struct objfile *objfile)
 {
   /* Let stabs reader clean up.  */
   stabsread_clear_cache ();
-
-  dwarf2_free_objfile (objfile);
 }
 
 
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index 1cabfbb0d45..55377dc1004 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -25003,13 +25003,13 @@ free_one_cached_comp_unit (struct dwarf2_per_cu_data *target_per_cu)
     }
 }
 
-/* Release all extra memory associated with OBJFILE.  */
+/* Cleanup function for the dwarf2_per_objfile data.  */
 
-void
-dwarf2_free_objfile (struct objfile *objfile)
+static void
+dwarf2_free_objfile (struct objfile *objfile, void *datum)
 {
   struct dwarf2_per_objfile *dwarf2_per_objfile
-    = get_dwarf2_per_objfile (objfile);
+    = (struct dwarf2_per_objfile *) datum;
 
   delete dwarf2_per_objfile;
 }
@@ -25331,8 +25331,8 @@ show_check_physname (struct ui_file *file, int from_tty,
 void
 _initialize_dwarf2_read (void)
 {
-
-  dwarf2_objfile_data_key = register_objfile_data ();
+  dwarf2_objfile_data_key
+    = register_objfile_data_with_cleanup (nullptr, dwarf2_free_objfile);
 
   add_prefix_cmd ("dwarf", class_maintenance, set_dwarf_cmd, _("\
 Set DWARF specific variables.\n\
diff --git a/gdb/elfread.c b/gdb/elfread.c
index 0fe2adbd4d2..358ec77b35b 100644
--- a/gdb/elfread.c
+++ b/gdb/elfread.c
@@ -1333,7 +1333,6 @@ elf_new_init (struct objfile *ignore)
 static void
 elf_symfile_finish (struct objfile *objfile)
 {
-  dwarf2_free_objfile (objfile);
 }
 
 /* ELF specific initialization routine for reading symbols.  */
diff --git a/gdb/symfile.h b/gdb/symfile.h
index d9185092eec..62072b104cc 100644
--- a/gdb/symfile.h
+++ b/gdb/symfile.h
@@ -614,8 +614,6 @@ extern bool dwarf2_initialize_objfile (struct objfile *objfile,
 extern void dwarf2_build_psymtabs (struct objfile *);
 extern void dwarf2_build_frame_info (struct objfile *);
 
-void dwarf2_free_objfile (struct objfile *);
-
 /* From mdebugread.c */
 
 extern void mdebug_build_psymtabs (minimal_symbol_reader &,
diff --git a/gdb/xcoffread.c b/gdb/xcoffread.c
index 7b9694bcff9..79b1df70fd0 100644
--- a/gdb/xcoffread.c
+++ b/gdb/xcoffread.c
@@ -1959,8 +1959,6 @@ xcoff_symfile_finish (struct objfile *objfile)
       inclTable = NULL;
     }
   inclIndx = inclLength = inclDepth = 0;
-
-  dwarf2_free_objfile (objfile);
 }
 
 
-- 
2.13.6