Windows gdb+gdbserver: Share $_siginfo reading code

Both GDB and GDBserver have similar code to read the $_siginfo data.
This patch moves the bulk of it to gdb/nat/windows-nat.c so it can be
shared.

Change-Id: I47fc0d3323be5b6f6fcfe912b768051a41910666

1 files changed, 4 insertions, 38 deletions

diff --git a/gdbserver/win32-low.cc b/gdbserver/win32-low.cc
index 985c6a0..4707acc 100644
--- a/gdbserver/win32-low.cc
+++ b/gdbserver/win32-low.cc
@@ -1308,45 +1308,11 @@ win32_process_target::qxfer_siginfo (const char *annex,
   windows_thread_info *th
     = windows_process.find_thread (current_thread_ptid ());
 
-  if (th->last_event.dwDebugEventCode != EXCEPTION_DEBUG_EVENT)
-    return -1;
-
-  if (readbuf == nullptr)
-    return -1;
-
-  EXCEPTION_RECORD &er = th->last_event.u.Exception.ExceptionRecord;
-
-  char *buf = (char *) &er;
-  size_t bufsize = sizeof (er);
-
-#ifdef __x86_64__
-  EXCEPTION_RECORD32 er32;
-  if (windows_process.wow64_process)
-    {
-      buf = (char *) &er32;
-      bufsize = sizeof (er32);
-
-      er32.ExceptionCode = er.ExceptionCode;
-      er32.ExceptionFlags = er.ExceptionFlags;
-      er32.ExceptionRecord
-	= (uintptr_t) er.ExceptionRecord;
-      er32.ExceptionAddress
-	= (uintptr_t) er.ExceptionAddress;
-      er32.NumberParameters = er.NumberParameters;
-      for (int i = 0; i < EXCEPTION_MAXIMUM_PARAMETERS; i++)
-	er32.ExceptionInformation[i] = er.ExceptionInformation[i];
-    }
-#endif
-
-  if (offset > bufsize)
+  ULONGEST xfered_len;
+  if (th->xfer_siginfo (readbuf, offset, len, &xfered_len))
+    return xfered_len;
+  else
     return -1;
-
-  if (offset + len > bufsize)
-    len = bufsize - offset;
-
-  memcpy (readbuf, buf + offset, len);
-
-  return len;
 }
 
 bool