[PATCH 16/17] Xtensa support

[Sergio Durigan Junior <sergiodj@redhat.com>]

Xtensa target support.  It uses a different value for SIGRTMAX,
therefore we have to handle it here.

2013-07-01  Sergio Durigan Junior  <sergiodj@redhat.com>

	* xtensa-linux-tdep.c: Define enum with differences between
	Xtensa and x86.
	(xtensa_linux_gdb_signal_to_target): New function.
	(xtensa_linux_init_abi): Set gdbarch_gdb_signal_to_target to
	xtensa_linux_gdb_signal_to_target.
---
 gdb/xtensa-linux-tdep.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/gdb/xtensa-linux-tdep.c b/gdb/xtensa-linux-tdep.c
index b7f11b9..3d1c356 100644
--- a/gdb/xtensa-linux-tdep.c
+++ b/gdb/xtensa-linux-tdep.c
@@ -23,6 +23,52 @@
 #include "solib-svr4.h"
 #include "symtab.h"
 
+/* This enum represents the signals' numbers on the Xtensa
+   architecture.  It just contains the signal definitions which are
+   different from x86.
+
+   It is derived from the file <arch/xtensa/include/uapi/asm/signal.h>,
+   from the Linux kernel tree.  */
+
+enum
+  {
+    XTENSA_LINUX_SIGRTMIN = 32,
+    XTENSA_LINUX_SIGRTMAX = 63,
+  };
+
+/* Implementation of `gdbarch_gdb_signal_to_target', as defined in
+   gdbarch.h.  */
+
+static int
+xtensa_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 XTENSA_LINUX_SIGRTMIN;
+
+    /* GDB_SIGNAL_REALTIME_64 is not valid on Xtensa.  */
+    case GDB_SIGNAL_REALTIME_64:
+      return -1;
+    }
+
+  /* GDB_SIGNAL_REALTIME_33 to _63 are continuous.
+
+     Xtensa does not have _64.  */
+  if (signal >= GDB_SIGNAL_REALTIME_33
+      && signal <= GDB_SIGNAL_REALTIME_63)
+    {
+      int offset = signal - GDB_SIGNAL_REALTIME_33;
+
+      return XTENSA_LINUX_SIGRTMIN + 1 + offset;
+    }
+
+  return linux_gdb_signal_to_target (gdbarch, signal);
+}
+
 /* OS specific initialization of gdbarch.  */
 
 static void
@@ -32,6 +78,9 @@ xtensa_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 
   set_solib_svr4_fetch_link_map_offsets
     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+
+  set_gdbarch_gdb_signal_to_target (gdbarch,
+				    xtensa_linux_gdb_signal_to_target);
 }
 
 /* Provide a prototype to silence -Wmissing-prototypes.  */
-- 
1.7.11.7