[PATCH] Create avr-linux-tdep.c (add reintroduce gdbarch_gdb_signal_{to,from}_target for that target)

[Sergio Durigan Junior <sergiodj at redhat dot com>]

Hi,

Given the discussion on:

<http://sourceware.org/ml/gdb-patches/2013-08/msg00290.html>
<http://sourceware.org/ml/gdb-patches/2013-08/msg00296.html>

Here is the patch to add avr-linux-tdep.c.  This patch also reimplements
gdbarch_gdb_signal_{to,from}_target for AVR targets running on Linux.

Joern, could you please give it a try (I don't have access to AVR
targets here), and tell me what you think?

Thanks,

-- 
Sergio

2013-08-12  Sergio Durigan Junior  <sergiodj@redhat.com>

	* Makefile.in (ALL_TARGET_OBS): Add avr-linux-tdep.o.
	(ALLDEPFILES): Add avr-linux-tdep.c.
	* avr-linux-tdep.c: New file.
	* configure.tgt: Add match for avr-*-*linux*.

diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 9171940..0be4198 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -548,7 +548,7 @@ ALL_TARGET_OBS = \
 	armbsd-tdep.o arm-linux-tdep.o arm-symbian-tdep.o \
 	armnbsd-tdep.o armobsd-tdep.o \
 	arm-tdep.o arm-wince-tdep.o \
-	avr-tdep.o \
+	avr-linux-tdep.o avr-tdep.o \
 	bfin-linux-tdep.o bfin-tdep.o \
 	cris-tdep.o \
 	dicos-tdep.o \
@@ -1473,7 +1473,7 @@ ALLDEPFILES = \
 	amd64-sol2-tdep.c \
 	arm-linux-nat.c arm-linux-tdep.c arm-symbian-tdep.c arm-tdep.c \
 	armnbsd-nat.c armbsd-tdep.c armnbsd-tdep.c armobsd-tdep.c \
-	avr-tdep.c \
+	avr-linux-tdep.c avr-tdep.c \
 	bfin-linux-tdep.c bfin-tdep.c \
 	bsd-uthread.c bsd-kvm.c \
 	core-regset.c \
diff --git a/gdb/avr-linux-tdep.c b/gdb/avr-linux-tdep.c
new file mode 100644
index 0000000..e45ddb7
--- /dev/null
+++ b/gdb/avr-linux-tdep.c
@@ -0,0 +1,115 @@
+/* Target-dependent code for Atmel AVR, for GDB.
+
+   Copyright (C) 2013 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/>.  */
+
+#include "defs.h"
+#include "gdbarch.h"
+#include "osabi.h"
+#include "linux-tdep.h"
+
+/* This enum represents the signals' numbers on the AVR
+   architecture.  It just contains the signal definitions which are
+   different from the generic implementation.
+
+   It is derived from the file <arch/avr32/include/uapi/asm/signal.h>,
+   from the Linux kernel tree.  */
+
+enum
+  {
+    AVR_LINUX_SIGRTMIN = 32,
+    AVR_LINUX_SIGRTMAX = 63,
+  };
+
+/* Implementation of `gdbarch_gdb_signal_from_target', as defined in
+   gdbarch.h.  */
+
+static enum gdb_signal
+avr_linux_gdb_signal_from_target (struct gdbarch *gdbarch, int signal)
+{
+  if (signal >= AVR_LINUX_SIGRTMIN && signal <= AVR_LINUX_SIGRTMAX)
+    {
+      int offset = signal - AVR_LINUX_SIGRTMIN;
+
+      if (offset == 0)
+	return GDB_SIGNAL_REALTIME_32;
+      else
+	return (enum gdb_signal) (offset - 1
+				  + (int) GDB_SIGNAL_REALTIME_33);
+    }
+  else if (signal > AVR_LINUX_SIGRTMAX)
+    return GDB_SIGNAL_UNKNOWN;
+
+  return linux_gdb_signal_from_target (gdbarch, signal);
+}
+
+/* Implementation of `gdbarch_gdb_signal_to_target', as defined in
+   gdbarch.h.  */
+
+static int
+avr_linux_gdb_signal_to_target (struct gdbarch *gdbarch,
+				enum gdb_signal signal)
+{
+  switch (signal)
+    {
+    /* GDB_SIGNAL_REALTIME_32 is not continuous in <gdb/signals.def>,
+       therefore we have to handle it here.  */
+    case GDB_SIGNAL_REALTIME_32:
+      return AVR_LINUX_SIGRTMIN;
+
+    /* GDB_SIGNAL_REALTIME_64 is not valid on AVR.  */
+    case GDB_SIGNAL_REALTIME_64:
+      return -1;
+    }
+
+  /* GDB_SIGNAL_REALTIME_33 to _63 are continuous.
+     AVR does not have _64.  */
+  if (signal >= GDB_SIGNAL_REALTIME_33
+      && signal <= GDB_SIGNAL_REALTIME_63)
+    {
+      int offset = signal - GDB_SIGNAL_REALTIME_33;
+
+      return AVR_LINUX_SIGRTMIN + 1 + offset;
+    }
+
+  return linux_gdb_signal_to_target (gdbarch, signal);
+}
+
+
+
+/* Initialize ABI for AVR.  */
+
+static void
+avr_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
+{
+  linux_init_abi (info, gdbarch);
+
+  set_gdbarch_gdb_signal_from_target (gdbarch,
+				      avr_linux_gdb_signal_from_target);
+  set_gdbarch_gdb_signal_to_target (gdbarch,
+				    avr_linux_gdb_signal_to_target);
+}
+
+/* Silence -Wmissing-prototypes.  */
+extern initialize_file_ftype _initialize_avr_linux_tdep;
+
+void
+_initialize_avr_linux_tdep (void)
+{
+  gdbarch_register_osabi (bfd_arch_avr, 0, GDB_OSABI_LINUX,
+                          avr_linux_init_abi);
+}
diff --git a/gdb/configure.tgt b/gdb/configure.tgt
index 653ba2b..500c596 100644
--- a/gdb/configure.tgt
+++ b/gdb/configure.tgt
@@ -111,6 +111,12 @@ arm*-*-*)
 	gdb_sim=../sim/arm/libsim.a
 	;;
 
+avr-*-*linux*)
+	# Target: AVR Linux
+	gdb_target_obs="avr-tdep.o avr-linux-tdep.o linux-tdep.o"
+	gdb_sim=../sim/avr/libsim.a
+	;;
+
 avr-*-*)
 	# Target: AVR
 	gdb_target_obs="avr-tdep.o"