[PATCH 17/17] MIPS support

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

Support for the MIPS target.  This is probably going to cause some
discussion/bikeshed.

MIPS already has a definition of its signals inside mips-linux-tdep.h
(see enum mips_signals).  I could have used them, but I chose to
follow the standard and implement an enum containing only differences
between MIPS and x86 signals.  In the battle between code duplication
and code standardization, the latter won (in my head, at least).  But I
am totally open to suggestions, and I even believe I know what I will
hear: "Please, use mips_signals".

Anyway, I thought it was worth raising this point here.

As a side note, if "use mips_signals" wins, I intend to rename the
elements in the enum to MIPS_LINUX_SIG*, instead of just using
MIPS_SIG*.  I guess that won't hurt.

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

	* mips-linux-tdep.c: Define enum with differences between
	* signals in MIPS and x86.
	(mips_gdb_signal_to_target): New function.
	(mips_linux_init_abi): Set gdbarch_gdb_signal_to_target to
	mips_gdb_signal_to_target.
---
 gdb/mips-linux-tdep.c | 132 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 132 insertions(+)

diff --git a/gdb/mips-linux-tdep.c b/gdb/mips-linux-tdep.c
index 484b39f..3aa6971 100644
--- a/gdb/mips-linux-tdep.c
+++ b/gdb/mips-linux-tdep.c
@@ -45,6 +45,42 @@
 
 static struct target_so_ops mips_svr4_so_ops;
 
+/* This enum represents the signals' numbers on the MIPS
+   architecture.  It just contains the signal definitions which are
+   different from x86.
+
+   It is derived from the file <arch/mips/include/uapi/asm/signal.h>,
+   from the Linux kernel tree.  */
+
+enum
+  {
+    MIPS_LINUX_SIGEMT = 7,
+    MIPS_LINUX_SIGBUS = 10,
+    MIPS_LINUX_SIGSYS = 12,
+    MIPS_LINUX_SIGUSR1 = 16,
+    MIPS_LINUX_SIGUSR2 = 17,
+    MIPS_LINUX_SIGCHLD = 18,
+    MIPS_LINUX_SIGCLD = MIPS_LINUX_SIGCHLD,
+    MIPS_LINUX_SIGPWR = 19,
+    MIPS_LINUX_SIGWINCH = 20,
+    MIPS_LINUX_SIGURG = 21,
+    MIPS_LINUX_SIGIO = 22,
+    MIPS_LINUX_SIGPOLL = MIPS_LINUX_SIGIO,
+    MIPS_LINUX_SIGSTOP = 23,
+    MIPS_LINUX_SIGTSTP = 24,
+    MIPS_LINUX_SIGCONT = 25,
+    MIPS_LINUX_SIGTTIN = 26,
+    MIPS_LINUX_SIGTTOU = 27,
+    MIPS_LINUX_SIGVTALRM = 28,
+    MIPS_LINUX_SIGPROF = 29,
+    MIPS_LINUX_SIGXCPU = 30,
+    MIPS_LINUX_SIGXFSZ = 31,
+
+    MIPS_LINUX_SIGRTMIN = 32,
+    MIPS_LINUX_SIGRT64 = 64,
+    MIPS_LINUX_SIGRTMAX = 127,
+  };
+
 /* Figure out where the longjmp will land.
    We expect the first arg to be a pointer to the jmp_buf structure
    from which we extract the pc (MIPS_LINUX_JB_PC) that we will land
@@ -1339,6 +1375,99 @@ mips_linux_get_syscall_number (struct gdbarch *gdbarch,
   return ret;
 }
 
+/* Implementation of `gdbarch_gdb_signal_to_target', as defined in
+   gdbarch.h.  */
+
+static int
+mips_gdb_signal_to_target (struct gdbarch *gdbarch,
+			   enum gdb_signal signal)
+{
+  switch (signal)
+    {
+    case GDB_SIGNAL_EMT:
+      return MIPS_LINUX_SIGEMT;
+
+    case GDB_SIGNAL_BUS:
+      return MIPS_LINUX_SIGBUS;
+
+    case GDB_SIGNAL_SYS:
+      return MIPS_LINUX_SIGSYS;
+
+    case GDB_SIGNAL_USR1:
+      return MIPS_LINUX_SIGUSR1;
+
+    case GDB_SIGNAL_USR2:
+      return MIPS_LINUX_SIGUSR2;
+
+    case GDB_SIGNAL_CHLD:
+      return MIPS_LINUX_SIGCHLD;
+
+    case GDB_SIGNAL_PWR:
+      return MIPS_LINUX_SIGPWR;
+
+    case GDB_SIGNAL_WINCH:
+      return MIPS_LINUX_SIGWINCH;
+
+    case GDB_SIGNAL_URG:
+      return MIPS_LINUX_SIGURG;
+
+    case GDB_SIGNAL_IO:
+      return MIPS_LINUX_SIGIO;
+
+    case GDB_SIGNAL_POLL:
+      return MIPS_LINUX_SIGPOLL;
+
+    case GDB_SIGNAL_STOP:
+      return MIPS_LINUX_SIGSTOP;
+
+    case GDB_SIGNAL_TSTP:
+      return MIPS_LINUX_SIGTSTP;
+
+    case GDB_SIGNAL_CONT:
+      return MIPS_LINUX_SIGCONT;
+
+    case GDB_SIGNAL_TTIN:
+      return MIPS_LINUX_SIGTTIN;
+
+    case GDB_SIGNAL_TTOU:
+      return MIPS_LINUX_SIGTTOU;
+
+    case GDB_SIGNAL_VTALRM:
+      return MIPS_LINUX_SIGVTALRM;
+
+    case GDB_SIGNAL_PROF:
+      return MIPS_LINUX_SIGPROF;
+
+    case GDB_SIGNAL_XCPU:
+      return MIPS_LINUX_SIGXCPU;
+
+    case GDB_SIGNAL_XFSZ:
+      return MIPS_LINUX_SIGXFSZ;
+
+    /* GDB_SIGNAL_REALTIME_32 is not continuous in <gdb/signals.def>,
+       therefore we have to handle it here.  */
+    case GDB_SIGNAL_REALTIME_32:
+      return MIPS_LINUX_SIGRTMIN;
+    }
+
+  if (signal >= GDB_SIGNAL_REALTIME_33
+      && signal <= GDB_SIGNAL_REALTIME_63)
+    {
+      int offset = signal - GDB_SIGNAL_REALTIME_33;
+
+      return MIPS_LINUX_SIGRTMIN + 1 + offset;
+    }
+  else if (signal >= GDB_SIGNAL_REALTIME_64
+	   && signal <= GDB_SIGNAL_REALTIME_127)
+    {
+      int offset = signal - GDB_SIGNAL_REALTIME_64;
+
+      return MIPS_LINUX_SIGRT64 + offset;
+    }
+
+  return linux_gdb_signal_to_target (gdbarch, signal);
+}
+
 /* Translate signals based on MIPS signal values.
    Adapted from gdb/common/signals.c.  */
 
@@ -1516,6 +1645,9 @@ mips_linux_init_abi (struct gdbarch_info info,
   set_gdbarch_gdb_signal_from_target (gdbarch,
 				      mips_gdb_signal_from_target);
 
+  set_gdbarch_gdb_signal_to_target (gdbarch,
+				    mips_gdb_signal_to_target);
+
   tdep->syscall_next_pc = mips_linux_syscall_next_pc;
 
   if (tdesc_data)
-- 
1.7.11.7