gcore, target: allow target to prepare/cleanup for/after core file generation

Add new target functions to_prepare_to_generate_core and
to_done_generating_core that are called before and after generating a core
file, respectively.

This allows targets to prepare for core file generation and to clean up
afterwards.

gdb/
	* target.h (target_ops) <to_prepare_to_generate_core>
	<to_done_generating_core>: New.
	(target_prepare_to_generate_core, target_done_generating_core): New.
	* target.c (target_prepare_to_generate_core)
	(target_done_generating_core): New.
	* target-delegates.c: Regenerate.
	* gcore.c: (write_gcore_file): Rename to ...
	(write_gcore_file_1): ...this.
	(write_gcore_file): Call target_prepare_to_generate_core
	and target_done_generating_core.

gdb/ChangeLog

@@ -1,3 +1,16 @@
+2014-06-25  Markus Metzger  <markus.t.metzger@intel.com>
+
+	* target.h (target_ops) <to_prepare_to_generate_core>
+	<to_done_generating_core>: New.
+	(target_prepare_to_generate_core, target_done_generating_core): New.
+	* target.c (target_prepare_to_generate_core)
+	(target_done_generating_core): New.
+	* target-delegates.c: Regenerate.
+	* gcore.c: (write_gcore_file): Rename to ...
+	(write_gcore_file_1): ...this.
+	(write_gcore_file): Call target_prepare_to_generate_core
+	and target_done_generating_core.
+
 2014-06-25  Markus Metzger  <markus.t.metzger@intel.com>
 
 	* fbsd-nat.c (fbsd_make_corefile_notes): Remove make_cleanup call.

gdb/gcore.c

@@ -61,12 +61,10 @@ create_gcore_bfd (const char *filename)
   return obfd;
 }
 
-/* write_gcore_file -- helper for gcore_command (exported).
+/* write_gcore_file_1 -- do the actual work of write_gcore_file.  */
-   Compose and write the corefile data to the core file.  */
 
-
+static void
-void
+write_gcore_file_1 (bfd *obfd)
-write_gcore_file (bfd *obfd)
 {
   struct cleanup *cleanup;
   void *note_data = NULL;
@@ -111,6 +109,25 @@ write_gcore_file (bfd *obfd)
   do_cleanups (cleanup);
 }
 
+/* write_gcore_file -- helper for gcore_command (exported).
+   Compose and write the corefile data to the core file.  */
+
+void
+write_gcore_file (bfd *obfd)
+{
+  volatile struct gdb_exception except;
+
+  target_prepare_to_generate_core ();
+
+  TRY_CATCH (except, RETURN_MASK_ALL)
+    write_gcore_file_1 (obfd);
+
+  target_done_generating_core ();
+
+  if (except.reason < 0)
+    throw_exception (except);
+}
+
 static void
 do_bfd_delete_cleanup (void *arg)
 {

gdb/target-delegates.c

@@ -1624,6 +1624,30 @@ delegate_decr_pc_after_break (struct target_ops *self, struct gdbarch *arg1)
   return self->to_decr_pc_after_break (self, arg1);
 }
 
+static void
+delegate_prepare_to_generate_core (struct target_ops *self)
+{
+  self = self->beneath;
+  self->to_prepare_to_generate_core (self);
+}
+
+static void
+tdefault_prepare_to_generate_core (struct target_ops *self)
+{
+}
+
+static void
+delegate_done_generating_core (struct target_ops *self)
+{
+  self = self->beneath;
+  self->to_done_generating_core (self);
+}
+
+static void
+tdefault_done_generating_core (struct target_ops *self)
+{
+}
+
 static void
 install_delegators (struct target_ops *ops)
 {
@@ -1897,6 +1921,10 @@ install_delegators (struct target_ops *ops)
     ops->to_get_tailcall_unwinder = delegate_get_tailcall_unwinder;
   if (ops->to_decr_pc_after_break == NULL)
     ops->to_decr_pc_after_break = delegate_decr_pc_after_break;
+  if (ops->to_prepare_to_generate_core == NULL)
+    ops->to_prepare_to_generate_core = delegate_prepare_to_generate_core;
+  if (ops->to_done_generating_core == NULL)
+    ops->to_done_generating_core = delegate_done_generating_core;
 }
 
 static void
@@ -2037,4 +2065,6 @@ install_dummy_methods (struct target_ops *ops)
   ops->to_get_unwinder = tdefault_get_unwinder;
   ops->to_get_tailcall_unwinder = tdefault_get_tailcall_unwinder;
   ops->to_decr_pc_after_break = default_target_decr_pc_after_break;
+  ops->to_prepare_to_generate_core = tdefault_prepare_to_generate_core;
+  ops->to_done_generating_core = tdefault_done_generating_core;
 }

gdb/target.c

@@ -3606,6 +3606,22 @@ target_decr_pc_after_break (struct gdbarch *gdbarch)
   return current_target.to_decr_pc_after_break (&current_target, gdbarch);
 }
 
+/* See target.h.  */
+
+void
+target_prepare_to_generate_core (void)
+{
+  current_target.to_prepare_to_generate_core (&current_target);
+}
+
+/* See target.h.  */
+
+void
+target_done_generating_core (void)
+{
+  current_target.to_done_generating_core (&current_target);
+}
+
 static void
 debug_to_files_info (struct target_ops *target)
 {

gdb/target.h

@@ -1109,6 +1109,14 @@ struct target_ops
 					 struct gdbarch *gdbarch)
       TARGET_DEFAULT_FUNC (default_target_decr_pc_after_break);
 
+    /* Prepare to generate a core file.  */
+    void (*to_prepare_to_generate_core) (struct target_ops *)
+      TARGET_DEFAULT_IGNORE ();
+
+    /* Cleanup after generating a core file.  */
+    void (*to_done_generating_core) (struct target_ops *)
+      TARGET_DEFAULT_IGNORE ();
+
     int to_magic;
     /* Need sub-structure for target machine related rather than comm related?
      */
@@ -2261,4 +2269,10 @@ extern CORE_ADDR forward_target_decr_pc_after_break (struct target_ops *ops,
 /* See to_decr_pc_after_break.  */
 extern CORE_ADDR target_decr_pc_after_break (struct gdbarch *gdbarch);
 
+/* See to_prepare_to_generate_core.  */
+extern void target_prepare_to_generate_core (void);
+
+/* See to_done_generating_core.  */
+extern void target_done_generating_core (void);
+
 #endif /* !defined (TARGET_H) */