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.

1 files changed, 15 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;