[binutils-gdb] Eliminate the 'the_core_target' global

[Pedro Alves <palves at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=451953fa440aa0ade02b652159155fae689483a3

commit 451953fa440aa0ade02b652159155fae689483a3
Author: Pedro Alves <palves@redhat.com>
Date:   Fri May 11 19:10:14 2018 +0100

    Eliminate the 'the_core_target' global
    
    (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:
    2018-05-11  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.

Diff:
---
 gdb/ChangeLog  | 12 ++++++++++++
 gdb/corefile.c | 18 ------------------
 gdb/corelow.c  | 42 +++++++++++++++++++++++++++++++-----------
 gdb/gdbcore.h  |  4 ----
 4 files changed, 43 insertions(+), 33 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 97ee0f9..2641884 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,15 @@
+2018-05-11  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.
+
 2018-05-11  Tom Tromey  <tromey@redhat.com>
 	    Pedro Alves  <tromey@redhat.com>
 
diff --git a/gdb/corefile.c b/gdb/corefile.c
index e0c7540..06b2686 100644
--- a/gdb/corefile.c
+++ b/gdb/corefile.c
@@ -51,24 +51,6 @@ static int exec_file_hook_count = 0;		/* Size of array.  */
 
 
 
-/* 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);
-}
-
-
 /* 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 97a957c..3b71a1b 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 d06ccc3..04a4b47 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;