This patch implements the new gdbarch method gdbarch_gdb_signal_to_target.

It will be used when one wants to convert between the internal GDB signal
representation (enum gdb_signal) and the target's representation.

The idea of this patch came from a chat between Pedro and I on IRC, plus
the discussion of my patches to add the new $_exitsignal convenience
variable:

	<http://sourceware.org/ml/gdb-patches/2013-06/msg00452.html>
	<http://sourceware.org/ml/gdb-patches/2013-06/msg00352.html>

What I did was to investigate, on the Linux kernel, which targets shared
the signal numbers definition with the generic definition, present at
<include/uapi/asm-generic/signal.h>.  For the record, I used linux-3.10-rc7
as the main source of information, always looking at
<arch/<ARCH_NAME>/include/uapi/asm/signal.h>.  For SIGRTMAX (which defaults
to _NSIG in most cases), I had to look at different signal-related
files, but most of them (except MIPS) were defined to 64 anyway.

Then, with all the differences in hand, I implemented the bits on each
target.

2013-08-09  Sergio Durigan Junior  <sergiodj@redhat.com>

	* linux-tdep.c: Define enum with generic signal numbers.
	(linux_gdb_signal_from_target): New function.
	(linux_gdb_signal_to_target): Likewise.
	(linux_init_abi): Set gdbarch_gdb_signal_{to,from}_target
	methods to the functions above.
	* linux-tdep.h (linux_gdb_signal_from_target): New prototype.
	(linux_gdb_signal_to_target): Likewise.
	* alpha-linux-tdep.c: Define new enum with signals different
	from generic Linux kernel.
	(alpha_linux_gdb_signal_from_target): New function.
	(alpha_linux_gdb_signal_to_target): Likewise.
	(alpha_linux_init_abi): Set gdbarch_gdb_signal_{to,from}_target
	with the functions mentioned above.
	* 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.
	* sparc-linux-tdep.c: Define enum with differences between SPARC
	and generic Linux kernel signal numbers.
	(sparc32_linux_gdb_signal_from_target): New function.
	(sparc32_linux_gdb_signal_to_target): Likewise.
	(sparc32_linux_init_abi): Set gdbarch_gdb_signal_{to,from}_target
	to the functions defined above.
	* 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.
	* mips-linux-tdep.c: Define enum with differences between
	signals in MIPS and Linux kernel generic ones.
	(mips_gdb_signal_to_target): New function.
	(mips_gdb_signal_from_target): Redefine to use new enum, handle
	only different signals from the Linux kernel generic.
	(mips_linux_init_abi): Set gdbarch_gdb_signal_{to,from}_target
	the functions defined above.
	* mips-linux-tdep.h (enum mips_signals): Remove.

1 files changed, 320 insertions, 0 deletions

diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c
index bfb6404..fbdca46 100644
--- a/gdb/linux-tdep.c
+++ b/gdb/linux-tdep.c
@@ -36,6 +36,71 @@
 
 #include <ctype.h>
 
+/* This enum represents the signals' numbers on a generic architecture
+   running the Linux kernel.  The definition of "generic" comes from
+   the file <include/uapi/asm-generic/signal.h>, from the Linux kernel
+   tree, which is the "de facto" implementation of signal numbers to
+   be used by new architecture ports.
+
+   For those architectures which have differences between the generic
+   standard (e.g., Alpha), we define the different signals (and *only*
+   those) in the specific target-dependent file (e.g.,
+   alpha-linux-tdep.c, for Alpha).  Please refer to the architecture's
+   tdep file for more information.
+
+   ARM deserves a special mention here.  On the file
+   <arch/arm/include/uapi/asm/signal.h>, it defines only one different
+   (and ARM-only) signal, which is SIGSWI, with the same number as
+   SIGRTMIN.  This signal is used only for a very specific target,
+   called ArthurOS (from RISCOS).  Therefore, we do not handle it on
+   the ARM-tdep file, and we can safely use the generic signal handler
+   here for ARM targets.
+
+   As stated above, this enum is derived from
+   <include/uapi/asm-generic/signal.h>, from the Linux kernel
+   tree.  */
+
+enum
+  {
+    LINUX_SIGHUP = 1,
+    LINUX_SIGINT = 2,
+    LINUX_SIGQUIT = 3,
+    LINUX_SIGILL = 4,
+    LINUX_SIGTRAP = 5,
+    LINUX_SIGABRT = 6,
+    LINUX_SIGIOT = 6,
+    LINUX_SIGBUS = 7,
+    LINUX_SIGFPE = 8,
+    LINUX_SIGKILL = 9,
+    LINUX_SIGUSR1 = 10,
+    LINUX_SIGSEGV = 11,
+    LINUX_SIGUSR2 = 12,
+    LINUX_SIGPIPE = 13,
+    LINUX_SIGALRM = 14,
+    LINUX_SIGTERM = 15,
+    LINUX_SIGSTKFLT = 16,
+    LINUX_SIGCHLD = 17,
+    LINUX_SIGCONT = 18,
+    LINUX_SIGSTOP = 19,
+    LINUX_SIGTSTP = 20,
+    LINUX_SIGTTIN = 21,
+    LINUX_SIGTTOU = 22,
+    LINUX_SIGURG = 23,
+    LINUX_SIGXCPU = 24,
+    LINUX_SIGXFSZ = 25,
+    LINUX_SIGVTALRM = 26,
+    LINUX_SIGPROF = 27,
+    LINUX_SIGWINCH = 28,
+    LINUX_SIGIO = 29,
+    LINUX_SIGPOLL = LINUX_SIGIO,
+    LINUX_SIGPWR = 30,
+    LINUX_SIGSYS = 31,
+    LINUX_SIGUNUSED = 31,
+
+    LINUX_SIGRTMIN = 32,
+    LINUX_SIGRTMAX = 64,
+  };
+
 static struct gdbarch_data *linux_gdbarch_data_handle;
 
 struct linux_gdbarch_data
@@ -1447,6 +1512,257 @@ linux_make_corefile_notes_1 (struct gdbarch *gdbarch, bfd *obfd, int *note_size)
 				      linux_collect_thread_registers);
 }
 
+/* Implementation of `gdbarch_gdb_signal_from_target', as defined in
+   gdbarch.h.  This function is not static because it is exported to
+   other -tdep files.  */
+
+enum gdb_signal
+linux_gdb_signal_from_target (struct gdbarch *gdbarch, int signal)
+{
+  switch (signal)
+    {
+    case 0:
+      return GDB_SIGNAL_0;
+
+    case LINUX_SIGHUP:
+      return GDB_SIGNAL_HUP;
+
+    case LINUX_SIGINT:
+      return GDB_SIGNAL_INT;
+
+    case LINUX_SIGQUIT:
+      return GDB_SIGNAL_QUIT;
+
+    case LINUX_SIGILL:
+      return GDB_SIGNAL_ILL;
+
+    case LINUX_SIGTRAP:
+      return GDB_SIGNAL_TRAP;
+
+    case LINUX_SIGABRT:
+      return GDB_SIGNAL_ABRT;
+
+    case LINUX_SIGBUS:
+      return GDB_SIGNAL_BUS;
+
+    case LINUX_SIGFPE:
+      return GDB_SIGNAL_FPE;
+
+    case LINUX_SIGKILL:
+      return GDB_SIGNAL_KILL;
+
+    case LINUX_SIGUSR1:
+      return GDB_SIGNAL_USR1;
+
+    case LINUX_SIGSEGV:
+      return GDB_SIGNAL_SEGV;
+
+    case LINUX_SIGUSR2:
+      return GDB_SIGNAL_USR2;
+
+    case LINUX_SIGPIPE:
+      return GDB_SIGNAL_PIPE;
+
+    case LINUX_SIGALRM:
+      return GDB_SIGNAL_ALRM;
+
+    case LINUX_SIGTERM:
+      return GDB_SIGNAL_TERM;
+
+    case LINUX_SIGCHLD:
+      return GDB_SIGNAL_CHLD;
+
+    case LINUX_SIGCONT:
+      return GDB_SIGNAL_CONT;
+
+    case LINUX_SIGSTOP:
+      return GDB_SIGNAL_STOP;
+
+    case LINUX_SIGTSTP:
+      return GDB_SIGNAL_TSTP;
+
+    case LINUX_SIGTTIN:
+      return GDB_SIGNAL_TTIN;
+
+    case LINUX_SIGTTOU:
+      return GDB_SIGNAL_TTOU;
+
+    case LINUX_SIGURG:
+      return GDB_SIGNAL_URG;
+
+    case LINUX_SIGXCPU:
+      return GDB_SIGNAL_XCPU;
+
+    case LINUX_SIGXFSZ:
+      return GDB_SIGNAL_XFSZ;
+
+    case LINUX_SIGVTALRM:
+      return GDB_SIGNAL_VTALRM;
+
+    case LINUX_SIGPROF:
+      return GDB_SIGNAL_PROF;
+
+    case LINUX_SIGWINCH:
+      return GDB_SIGNAL_WINCH;
+
+    /* No way to differentiate between SIGIO and SIGPOLL.
+       Therefore, we just handle the first one.  */
+    case LINUX_SIGIO:
+      return GDB_SIGNAL_IO;
+
+    case LINUX_SIGPWR:
+      return GDB_SIGNAL_PWR;
+
+    case LINUX_SIGSYS:
+      return GDB_SIGNAL_SYS;
+
+    /* SIGRTMIN and SIGRTMAX are not continuous in <gdb/signals.def>,
+       therefore we have to handle them here.  */
+    case LINUX_SIGRTMIN:
+      return GDB_SIGNAL_REALTIME_32;
+
+    case LINUX_SIGRTMAX:
+      return GDB_SIGNAL_REALTIME_64;
+    }
+
+  if (signal >= LINUX_SIGRTMIN + 1 && signal <= LINUX_SIGRTMAX - 1)
+    {
+      int offset = signal - LINUX_SIGRTMIN + 1;
+
+      return (enum gdb_signal) ((int) GDB_SIGNAL_REALTIME_33 + offset);
+    }
+
+  return GDB_SIGNAL_UNKNOWN;
+}
+
+/* Implementation of `gdbarch_gdb_signal_to_target', as defined in
+   gdbarch.h.  This function is not static because it is exported to
+   other -tdep files.  */
+
+int
+linux_gdb_signal_to_target (struct gdbarch *gdbarch,
+			    enum gdb_signal signal)
+{
+  switch (signal)
+    {
+    case GDB_SIGNAL_0:
+      return 0;
+
+    case GDB_SIGNAL_HUP:
+      return LINUX_SIGHUP;
+
+    case GDB_SIGNAL_INT:
+      return LINUX_SIGINT;
+
+    case GDB_SIGNAL_QUIT:
+      return LINUX_SIGQUIT;
+
+    case GDB_SIGNAL_ILL:
+      return LINUX_SIGILL;
+
+    case GDB_SIGNAL_TRAP:
+      return LINUX_SIGTRAP;
+
+    case GDB_SIGNAL_ABRT:
+      return LINUX_SIGABRT;
+
+    case GDB_SIGNAL_FPE:
+      return LINUX_SIGFPE;
+
+    case GDB_SIGNAL_KILL:
+      return LINUX_SIGKILL;
+
+    case GDB_SIGNAL_BUS:
+      return LINUX_SIGBUS;
+
+    case GDB_SIGNAL_SEGV:
+      return LINUX_SIGSEGV;
+
+    case GDB_SIGNAL_SYS:
+      return LINUX_SIGSYS;
+
+    case GDB_SIGNAL_PIPE:
+      return LINUX_SIGPIPE;
+
+    case GDB_SIGNAL_ALRM:
+      return LINUX_SIGALRM;
+
+    case GDB_SIGNAL_TERM:
+      return LINUX_SIGTERM;
+
+    case GDB_SIGNAL_URG:
+      return LINUX_SIGURG;
+
+    case GDB_SIGNAL_STOP:
+      return LINUX_SIGSTOP;
+
+    case GDB_SIGNAL_TSTP:
+      return LINUX_SIGTSTP;
+
+    case GDB_SIGNAL_CONT:
+      return LINUX_SIGCONT;
+
+    case GDB_SIGNAL_CHLD:
+      return LINUX_SIGCHLD;
+
+    case GDB_SIGNAL_TTIN:
+      return LINUX_SIGTTIN;
+
+    case GDB_SIGNAL_TTOU:
+      return LINUX_SIGTTOU;
+
+    case GDB_SIGNAL_IO:
+      return LINUX_SIGIO;
+
+    case GDB_SIGNAL_XCPU:
+      return LINUX_SIGXCPU;
+
+    case GDB_SIGNAL_XFSZ:
+      return LINUX_SIGXFSZ;
+
+    case GDB_SIGNAL_VTALRM:
+      return LINUX_SIGVTALRM;
+
+    case GDB_SIGNAL_PROF:
+      return LINUX_SIGPROF;
+
+    case GDB_SIGNAL_WINCH:
+      return LINUX_SIGWINCH;
+
+    case GDB_SIGNAL_USR1:
+      return LINUX_SIGUSR1;
+
+    case GDB_SIGNAL_USR2:
+      return LINUX_SIGUSR2;
+
+    case GDB_SIGNAL_PWR:
+      return LINUX_SIGPWR;
+
+    case GDB_SIGNAL_POLL:
+      return LINUX_SIGPOLL;
+
+    /* GDB_SIGNAL_REALTIME_32 is not continuous in <gdb/signals.def>,
+       therefore we have to handle it here.  */
+    case GDB_SIGNAL_REALTIME_32:
+      return LINUX_SIGRTMIN;
+
+    /* Same comment applies to _64.  */
+    case GDB_SIGNAL_REALTIME_64:
+      return LINUX_SIGRTMAX;
+    }
+
+  /* GDB_SIGNAL_REALTIME_33 to _64 are continuous.  */
+  if (signal >= GDB_SIGNAL_REALTIME_33
+      && signal <= GDB_SIGNAL_REALTIME_63)
+    {
+      int offset = signal - GDB_SIGNAL_REALTIME_33;
+
+      return LINUX_SIGRTMIN + 1 + offset;
+    }
+
+  return -1;
+}
+
 /* To be called from the various GDB_OSABI_LINUX handlers for the
    various GNU/Linux architectures and machine types.  */
 
@@ -1460,6 +1776,10 @@ linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   set_gdbarch_make_corefile_notes (gdbarch, linux_make_corefile_notes_1);
   set_gdbarch_has_shared_address_space (gdbarch,
 					linux_has_shared_address_space);
+  set_gdbarch_gdb_signal_from_target (gdbarch,
+				      linux_gdb_signal_from_target);
+  set_gdbarch_gdb_signal_to_target (gdbarch,
+				    linux_gdb_signal_to_target);
 }
 
 /* Provide a prototype to silence -Wmissing-prototypes.  */