[Committing the `catch syscall' patch for ARM, from Samuel Bronson.]

This time, it passes all the tests and comes with a nearly complete
XML file (plus a script that can nearly regenerate the XML file).

(I elected to leave out __ARM_NR_cmpxchg, since it has dire warnings
to the effect that the only pieces of code that should be aware of it
are the implementation and the __kuser_cmpxchg code in entry-armv.S.)

gdb/
2013-08-14  Samuel Bronson  <naesten@gmail.com>

	ARM Linux support for `catch syscall'.
	* syscalls/arm-linux.py: New file.
	* syscalls/arm-linux.xml: Likewise.
	* arm-linux-tdep.c (arm_linux_get_syscall_number): New function.
	(arm_linux_init_abi): Register the new function and syscall xml file.
	* data-directory/Makefile.in: Install the new syscall xml file.
	* NEWS: Brag about this.

gdb/testsuite/
2013-08-14  Samuel Bronson  <naesten@gmail.com>

	ARM Linux support for `catch syscall'.
	* gdb.base/catch-syscall.exp: Test this on ARM now.
	(fill_all_syscalls_numbers): ARM has close/chroot on 6/61, too.

1 files changed, 58 insertions, 0 deletions

diff --git a/gdb/arm-linux-tdep.c b/gdb/arm-linux-tdep.c
index 1502bdc..6ac61cc 100644
--- a/gdb/arm-linux-tdep.c
+++ b/gdb/arm-linux-tdep.c
@@ -33,6 +33,7 @@
 #include "tramp-frame.h"
 #include "breakpoint.h"
 #include "auxv.h"
+#include "xml-syscall.h"
 
 #include "arm-tdep.h"
 #include "arm-linux-tdep.h"
@@ -794,6 +795,59 @@ arm_linux_sigreturn_return_addr (struct frame_info *frame,
   return 0;
 }
 
+/* At a ptrace syscall-stop, return the syscall number.  This either
+   comes from the SWI instruction (OABI) or from r7 (EABI).
+
+   When the function fails, it should return -1.  */
+
+static LONGEST
+arm_linux_get_syscall_number (struct gdbarch *gdbarch,
+			      ptid_t ptid)
+{
+  struct regcache *regs = get_thread_regcache (ptid);
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+  ULONGEST pc;
+  ULONGEST cpsr;
+  ULONGEST t_bit = arm_psr_thumb_bit (gdbarch);
+  int is_thumb;
+  ULONGEST svc_number = -1;
+
+  regcache_cooked_read_unsigned (regs, ARM_PC_REGNUM, &pc);
+  regcache_cooked_read_unsigned (regs, ARM_PS_REGNUM, &cpsr);
+  is_thumb = (cpsr & t_bit) != 0;
+
+  if (is_thumb)
+    {
+      regcache_cooked_read_unsigned (regs, 7, &svc_number);
+    }
+  else
+    {
+      enum bfd_endian byte_order_for_code = 
+	gdbarch_byte_order_for_code (gdbarch);
+
+      /* PC gets incremented before the syscall-stop, so read the
+	 previous instruction.  */
+      unsigned long this_instr = 
+	read_memory_unsigned_integer (pc - 4, 4, byte_order_for_code);
+
+      unsigned long svc_operand = (0x00ffffff & this_instr);
+
+      if (svc_operand)
+	{
+          /* OABI */
+	  svc_number = svc_operand - 0x900000;
+	}
+      else
+	{
+          /* EABI */
+	  regcache_cooked_read_unsigned (regs, 7, &svc_number);
+	}
+    }
+
+  return svc_number;
+}
+
 /* When FRAME is at a syscall instruction, return the PC of the next
    instruction to be executed.  */
 
@@ -1294,6 +1348,10 @@ arm_linux_init_abi (struct gdbarch_info info,
 
   tdep->syscall_next_pc = arm_linux_syscall_next_pc;
 
+  /* `catch syscall' */
+  set_xml_syscall_file_name ("syscalls/arm-linux.xml");
+  set_gdbarch_get_syscall_number (gdbarch, arm_linux_get_syscall_number);
+
   /* Syscall record.  */
   tdep->arm_swi_record = NULL;
 }