[PATCH 4/7] AVR support

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

Support for the AVR architecture.  More of the same.  Defining an enum
containing the differences between Linux kernel generic and AVR signals,
and treat them on avr_linux_gdb_signal_{to,from}_target.  In this case,
the only difference is the SIGRTMAX.

2013-07-26  Sergio Durigan Junior  <sergiodj@redhat.com>

	* avr-tdep.c: Define enum with differences between Linux kernel
	and AVR signals.
	(avr_linux_gdb_signal_from_target): New function.
	(avr_linux_gdb_signal_to_target): Likewise.
	(avr_gdbarch_init): Set gdbarch_gdb_signal_{to,from}_target to
	the functions mentioned above.
---
 gdb/avr-tdep.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)

diff --git a/gdb/avr-tdep.c b/gdb/avr-tdep.c
index 0bc08a8..f3bf0c9 100644
--- a/gdb/avr-tdep.c
+++ b/gdb/avr-tdep.c
@@ -36,6 +36,7 @@
 #include "regcache.h"
 #include "gdb_string.h"
 #include "dis-asm.h"
+#include "linux-tdep.h"
 
 /* AVR Background:
 
@@ -193,6 +194,19 @@ struct gdbarch_tdep
   struct type *pc_type;
 };
 
+/* This enum represents the signals' numbers on the AVR
+   architecture.  It just contains the signal definitions which are
+   different from x86.
+
+   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,
+  };
+
 /* Lookup the name of a register given it's number.  */
 
 static const char *
@@ -1344,6 +1358,61 @@ avr_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg)
   return -1;
 }
 
+/* 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 the gdbarch structure for the AVR's.  */
 
 static struct gdbarch *
@@ -1447,6 +1516,11 @@ avr_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   set_gdbarch_unwind_pc (gdbarch, avr_unwind_pc);
   set_gdbarch_unwind_sp (gdbarch, avr_unwind_sp);
 
+  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);
+
   return gdbarch;
 }
 
-- 
1.7.11.7