[PATCH 6/7] 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.

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

	* xtensa-linux-tdep.c: Define enum with differences between
	Xtensa and Linux kernel generic signals.
	(xtensa_linux_gdb_signal_from_target): New function.
	(xtensa_linux_gdb_signal_to_target): Likewise.
	(xtensa_linux_init_abi): Set gdbarch_gdb_signal_to_target
	to the functions defined above.
---
 gdb/xtensa-linux-tdep.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)

diff --git a/gdb/xtensa-linux-tdep.c b/gdb/xtensa-linux-tdep.c
index b7f11b9..fb32826 100644
--- a/gdb/xtensa-linux-tdep.c
+++ b/gdb/xtensa-linux-tdep.c
@@ -23,6 +23,75 @@
 #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_from_target', as defined in
+   gdbarch.h.  */
+
+static enum gdb_signal
+xtensa_linux_gdb_signal_from_target (struct gdbarch *gdbarch,
+				   int signal)
+{
+  if (signal >= XTENSA_LINUX_SIGRTMIN && signal <= XTENSA_LINUX_SIGRTMAX)
+    {
+      int offset = signal - XTENSA_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 > XTENSA_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
+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 +101,11 @@ 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_from_target (gdbarch,
+				      xtensa_linux_gdb_signal_from_target);
+  set_gdbarch_gdb_signal_to_target (gdbarch,
+				    xtensa_linux_gdb_signal_to_target);
 }
 
 /* Provide a prototype to silence -Wmissing-prototypes.  */
-- 
1.7.11.7