Introduce common-debug.h

This introduces common-debug.h.  This holds the functions debug_printf
and debug_vprintf, two functions that the common code can use to print
debugging messages.  Clients of the common code are expected to
implement debug_vprintf; a debug_vprintf function is written from
scratch for GDB, and gdbserver's existing debug_printf is repurposed
as debug_vprintf.

common/agent.c is changed to use debug_vprintf rather than
defining the macro DEBUG_AGENT depending on GDBSERVER.

nat/i386-dregs.c is changed to use the externally-implemented
debug_printf, rather than defining it itself.

gdb/ChangeLog:

	* common/common-debug.h: New file.
	* common/common-debug.c: Likewise.
	* debug.c: Likewise.
	* Makefile.in (SFILES): Add common/common-debug.c.
	(HFILES_NO_SRCDIR): Add common/common-debug.h.
	(COMMON_OBS): Add common-debug.o and debug.o.
	(common-debug.o): New rule.
	* common/common-defs.h: Include common-debug.h.
	* common/agent.c (debug_agent_printf): New function.
	(DEBUG_AGENT): Redefine.
	* nat/i386-dregs.c (debug_printf): Undefine.

gdb/gdbserver/ChangeLog:

	* Makefile.in (SFILES): Add common/common-debug.c.
	(OBS): Add common-debug.o.
	(common-debug.o): New rule.
	* debug.h (debug_printf): Don't declare.
	* debug.c (debug_printf): Renamed and rewritten as...
	(debug_vprintf): New function.

4 files changed, 89 insertions, 9 deletions

diff --git a/gdb/common/agent.c b/gdb/common/agent.c
index 3f868ba..2963917 100644
--- a/gdb/common/agent.c
+++ b/gdb/common/agent.c
@@ -31,15 +31,21 @@
 
 int debug_agent = 0;
 
-#ifdef GDBSERVER
-#define DEBUG_AGENT(fmt, args...)	\
-  if (debug_agent)			\
-    fprintf (stderr, fmt, ##args);
-#else
-#define DEBUG_AGENT(fmt, args...)	\
-  if (debug_agent)			\
-    fprintf_unfiltered (gdb_stdlog, fmt, ##args);
-#endif
+/* A stdarg wrapper for debug_vprintf.  */
+
+static void ATTRIBUTE_PRINTF (1, 2)
+debug_agent_printf (const char *fmt, ...)
+{
+  va_list ap;
+
+  if (!debug_agent)
+    return;
+  va_start (ap, fmt);
+  debug_vprintf (fmt, ap);
+  va_end (ap);
+}
+
+#define DEBUG_AGENT debug_agent_printf
 
 /* Global flag to determine using agent or not.  */
 int use_agent = 0;
diff --git a/gdb/common/common-debug.c b/gdb/common/common-debug.c
new file mode 100644
index 0000000..660fc70
--- /dev/null
+++ b/gdb/common/common-debug.c
@@ -0,0 +1,37 @@
+/* Debug printing functions.
+
+   Copyright (C) 2014 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef GDBSERVER
+#include "server.h"
+#else
+#include "defs.h"
+#endif
+#include "common-debug.h"
+
+/* See common/common-debug.h.  */
+
+void
+debug_printf (const char *fmt, ...)
+{
+  va_list ap;
+
+  va_start (ap, fmt);
+  debug_vprintf (fmt, ap);
+  va_end (ap);
+}
diff --git a/gdb/common/common-debug.h b/gdb/common/common-debug.h
new file mode 100644
index 0000000..c2bb192
--- /dev/null
+++ b/gdb/common/common-debug.h
@@ -0,0 +1,36 @@
+/* Declarations for debug printing functions.
+
+   Copyright (C) 2014 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef COMMON_DEBUG_H
+#define COMMON_DEBUG_H
+
+/* Print a formatted message to the appropriate channel for
+   debugging output for the client.  */
+
+extern void debug_printf (const char *format, ...)
+     ATTRIBUTE_PRINTF (1, 2);
+
+/* Print a formatted message to the appropriate channel for
+   debugging output for the client.  This function must be
+   provided by the client.  */
+
+extern void debug_vprintf (const char *format, va_list ap)
+     ATTRIBUTE_PRINTF (1, 0);
+
+#endif /* COMMON_DEBUG_H */
diff --git a/gdb/common/common-defs.h b/gdb/common/common-defs.h
index 66c0d21..2d3444b 100644
--- a/gdb/common/common-defs.h
+++ b/gdb/common/common-defs.h
@@ -44,5 +44,6 @@
 #include "errors.h"
 #include "common-types.h"
 #include "print-utils.h"
+#include "common-debug.h"
 
 #endif /* COMMON_DEFS_H */