[PATCH 2/3] Eliminate the 'the_core_target' global

Pedro Alves
2018-05-03T16:22:40Z

(previously called 'core_target', but since renamed because
'core_target' is the name of the target_ops class now.)

This eliminates the "the_core_target" global, as preparation for being
able to have more than one core loaded. When we get there, we will
instantiate one core_target object per core instead.

Essentially, this replaces the reference to the_core_target in
core_file_command by a reference to core_bfd, which is per
program_space.

Currently, core_file_command calls 'the_core_target->detach()' even if
the core target is not open and pushed on the target stack. If it is
indeed not open, then the practical effect is that
core_target::detach() prints "No core file now.". That is preserved
by printing that directly from within core_file_command if not
debugging a core.

gdb/ChangeLog:
yyyy-mm-dd Pedro Alves <palves@redhat.com>

* corefile.c (core_file_command): Move to corelow.c.
* corelow.c (the_core_target): Delete.
(core_file_command): Moved from corefile.c. Check exec_bfd
instead of the_core_target. Use target_detach instead of calling
into the_core_target directly.
(maybe_say_no_core_file_now): New.
(core_target::detach): Use it.
(_initialize_corelow): Remove references to the_core_target.
* gdbcore.h (the_core_target): Delete.
---
gdb/corefile.c | 18 ------------------
gdb/corelow.c | 42 +++++++++++++++++++++++++++++++-----------
gdb/gdbcore.h | 4 ----
3 files changed, 31 insertions(+), 33 deletions(-)

diff --git a/gdb/corefile.c b/gdb/corefile.c
index e0c7540140..06b26863f3 100644
--- a/gdb/corefile.c
+++ b/gdb/corefile.c
@@ -51,24 +51,6 @@ static int exec_file_hook_count = 0; /* Size of array. */

\f

-/* Backward compatability with old way of specifying core files. */
-
-void
-core_file_command (const char *filename, int from_tty)
-{
- dont_repeat (); /* Either way, seems bogus. */
-
- if (!filename)
- {
- gdb_assert (the_core_target != NULL);
-
- the_core_target->detach (current_inferior (), from_tty);
- }
- else
- core_target_open (filename, from_tty);
-}
-\f
-
/* If there are two or more functions that wish to hook into
exec_file_command, this function will call all of the hook
functions. */
diff --git a/gdb/corelow.c b/gdb/corelow.c
index 97a957c8fc..3b71a1b856 100644
--- a/gdb/corelow.c
+++ b/gdb/corelow.c
@@ -92,9 +92,6 @@ public:
bool info_proc (const char *, enum info_proc_what) override;
};

-/* See gdbcore.h. */
-struct target_ops *the_core_target;
-
/* List of all available core_fns. On gdb startup, each core file
register reader calls deprecated_add_core_fns() to register
information on each core format it is prepared to read. */
@@ -309,6 +306,36 @@ add_to_thread_list (bfd *abfd, asection *asect, void *reg_sect_arg)
inferior_ptid = ptid; /* Yes, make it current. */
}

+/* Issue a message saying we have no core to debug, if FROM_TTY. */
+
+static void
+maybe_say_no_core_file_now (int from_tty)
+{
+ if (from_tty)
+ printf_filtered (_("No core file now.\n"));
+}
+
+/* Backward compatability with old way of specifying core files. */
+
+void
+core_file_command (const char *filename, int from_tty)
+{
+ dont_repeat (); /* Either way, seems bogus. */
+
+ if (filename == NULL)
+ {
+ if (core_bfd != NULL)
+ {
+ target_detach (current_inferior (), from_tty);
+ gdb_assert (core_bfd == NULL);
+ }
+ else
+ maybe_say_no_core_file_now (from_tty);
+ }
+ else
+ core_target_open (filename, from_tty);
+}
+
/* See gdbcore.h. */

void
@@ -513,8 +540,7 @@ core_target::detach (inferior *inf, int from_tty)
{
unpush_target (this);
reinit_frame_cache ();
- if (from_tty)
- printf_filtered (_("No core file now.\n"));
+ maybe_say_no_core_file_now (from_tty);
}

/* Try to retrieve registers from a section in core_bfd, and supply
@@ -1021,11 +1047,5 @@ core_target::info_proc (const char *args, enum info_proc_what request)
void
_initialize_corelow (void)
{
- if (the_core_target != NULL)
- internal_error (__FILE__, __LINE__,
- _("core target already exists (\"%s\")."),
- the_core_target->longname ());
- the_core_target = &core_ops;
-
add_target (core_target_info, core_target_open, filename_completer);
}
diff --git a/gdb/gdbcore.h b/gdb/gdbcore.h
index d06ccc3507..04a4b4767a 100644
--- a/gdb/gdbcore.h
+++ b/gdb/gdbcore.h
@@ -135,10 +135,6 @@ extern void specify_exec_file_hook (void (*hook) (const char *filename));

#define core_bfd (current_program_space->cbfd)

-/* corelow.c target. It is never NULL after GDB initialization. */
-
-extern struct target_ops *the_core_target;
-
/* Whether to open exec and core files read-only or read-write. */

extern int write_files;
--
2.14.3