--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/config/s390/tpf-unwind.h	Fri Jul 17 14:47:48 2009 +0900
@@ -0,0 +1,252 @@
+/* DWARF2 EH unwinding support for TPF OS.
+   Copyright (C) 2004, 2005, 2009 Free Software Foundation, Inc.
+   Contributed by P.J. Darcy (darcypj@us.ibm.com).
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+#include <dlfcn.h>
+
+/* Function Name: __isPATrange
+   Parameters passed into it:  address to check
+   Return Value: A 1 if address is in pat code "range", 0 if not
+   Description: This function simply checks to see if the address
+   passed to it is in the CP pat code range.  */
+
+#define MIN_PATRANGE 0x10000
+#define MAX_PATRANGE 0x800000
+
+static inline unsigned int
+__isPATrange (void *addr)
+{
+  if (addr > (void *)MIN_PATRANGE && addr < (void *)MAX_PATRANGE)
+    return 1;
+  else
+    return 0;
+}
+
+/* TPF return address offset from start of stack frame.  */
+#define TPFRA_OFFSET 168
+
+/* Exceptions macro defined for TPF so that functions without 
+   dwarf frame information can be used with exceptions.  */
+#define MD_FALLBACK_FRAME_STATE_FOR s390_fallback_frame_state
+
+static _Unwind_Reason_Code
+s390_fallback_frame_state (struct _Unwind_Context *context,
+			   _Unwind_FrameState *fs)
+{
+  unsigned long int regs;
+  unsigned long int new_cfa;
+  int i;
+
+  regs = *((unsigned long int *)
+        (((unsigned long int) context->cfa) - STACK_POINTER_OFFSET));
+
+  /* Are we going through special linkage code?  */
+  if (__isPATrange (context->ra))
+    {
+
+      /* Our return register isn't zero for end of stack, so
+         check backward stackpointer to see if it is zero.  */
+      if (regs == NULL)
+         return _URC_END_OF_STACK;
+
+      /* No stack frame.  */
+      fs->regs.cfa_how = CFA_REG_OFFSET;
+      fs->regs.cfa_reg = 15;
+      fs->regs.cfa_offset = STACK_POINTER_OFFSET;
+
+      /* All registers remain unchanged ...  */
+      for (i = 0; i < 32; i++)
+	{
+	  fs->regs.reg[i].how = REG_SAVED_REG;
+	  fs->regs.reg[i].loc.reg = i;
+	}
+
+      /* ... except for %r14, which is stored at CFA-112
+	 and used as return address.  */
+      fs->regs.reg[14].how = REG_SAVED_OFFSET;
+      fs->regs.reg[14].loc.offset = TPFRA_OFFSET - STACK_POINTER_OFFSET;
+      fs->retaddr_column = 14;
+
+      return _URC_NO_REASON;
+    }
+
+  regs = *((unsigned long int *)
+        (((unsigned long int) context->cfa) - STACK_POINTER_OFFSET));
+  new_cfa = regs + STACK_POINTER_OFFSET;
+
+  fs->regs.cfa_how = CFA_REG_OFFSET;
+  fs->regs.cfa_reg = 15;
+  fs->regs.cfa_offset = new_cfa -
+        (unsigned long int) context->cfa + STACK_POINTER_OFFSET;
+
+  for (i = 0; i < 16; i++)
+    {
+      fs->regs.reg[i].how = REG_SAVED_OFFSET;
+      fs->regs.reg[i].loc.offset = regs + i*8 - new_cfa;
+    }
+
+  for (i = 0; i < 4; i++)
+    {
+      fs->regs.reg[16 + i].how = REG_SAVED_OFFSET;
+      fs->regs.reg[16 + i].loc.offset = regs + 16*8 + i*8 - new_cfa;
+    }
+
+  fs->retaddr_column = 14;
+
+  return _URC_NO_REASON;
+}
+
+/* Function Name: __tpf_eh_return
+   Parameters passed into it: Destination address to jump to.
+   Return Value: Converted Destination address if a Pat Stub exists.
+   Description: This function swaps the unwinding return address
+      with the cp stub code.  The original target return address is
+      then stored into the tpf return address field.  The cp stub
+      code is searched for by climbing back up the stack and
+      comparing the tpf stored return address object address to
+      that of the targets object address.  */
+
+#define CURRENT_STACK_PTR() \
+  ({ register unsigned long int *stack_ptr asm ("%r15"); stack_ptr; })
+
+#define PREVIOUS_STACK_PTR() \
+  ((unsigned long int *)(*(CURRENT_STACK_PTR())))
+
+#define RA_OFFSET 112
+#define R15_OFFSET 120
+#define TPFAREA_OFFSET 160
+#define TPFAREA_SIZE STACK_POINTER_OFFSET-TPFAREA_OFFSET
+#define INVALID_RETURN 0
+
+void * __tpf_eh_return (void *target);
+
+void *
+__tpf_eh_return (void *target)
+{
+  Dl_info targetcodeInfo, currentcodeInfo;
+  int retval;
+  void *current, *stackptr, *destination_frame;
+  unsigned long int shifter, is_a_stub;
+
+  is_a_stub = 0;
+
+  /* Get code info for target return's address.  */
+  retval = dladdr (target, &targetcodeInfo);
+
+  /* Ensure the code info is valid (for target).  */
+  if (retval != INVALID_RETURN)
+    {
+
+      /* Get the stack pointer of the stack frame to be modified by
+         the exception unwinder.  So that we can begin our climb
+         there.  */
+      stackptr = (void *) *((unsigned long int *) (*(PREVIOUS_STACK_PTR())));
+
+      /* Begin looping through stack frames.  Stop if invalid
+         code information is retrieved or if a match between the
+         current stack frame iteration shared object's address 
+         matches that of the target, calculated above.  */
+      do
+        {
+          /* Get return address based on our stackptr iterator.  */
+          current = (void *) *((unsigned long int *) 
+                      (stackptr+RA_OFFSET));
+
+          /* Is it a Pat Stub?  */
+          if (__isPATrange (current)) 
+            {
+              /* Yes it was, get real return address 
+                 in TPF stack area.  */
+              current = (void *) *((unsigned long int *) 
+                          (stackptr+TPFRA_OFFSET));
+              is_a_stub = 1;
+            }
+
+          /* Get codeinfo on RA so that we can figure out
+             the module address.  */
+          retval = dladdr (current, &currentcodeInfo);
+
+          /* Check that codeinfo for current stack frame is valid.
+             Then compare the module address of current stack frame
+             to target stack frame to determine if we have the pat
+             stub address we want.  Also ensure we are dealing
+             with a module crossing, stub return address. */
+          if (is_a_stub && retval != INVALID_RETURN
+             && targetcodeInfo.dli_fbase == currentcodeInfo.dli_fbase)
+             {
+               /* Yes! They are in the same module.
+                  Force copy of TPF private stack area to
+                  destination stack frame TPF private area. */
+               destination_frame = (void *) *((unsigned long int *) 
+                   (*PREVIOUS_STACK_PTR() + R15_OFFSET));
+
+               /* Copy TPF linkage area from current frame to
+                  destination frame.  */
+               memcpy((void *) (destination_frame + TPFAREA_OFFSET),
+                 (void *) (stackptr + TPFAREA_OFFSET), TPFAREA_SIZE);
+
+               /* Now overlay the
+                  real target address into the TPF stack area of
+                  the target frame we are jumping to.  */
+               *((unsigned long int *) (destination_frame + 
+                   TPFRA_OFFSET)) = (unsigned long int) target;
+
+               /* Before returning the desired pat stub address to
+                  the exception handling unwinder so that it can 
+                  actually do the "leap" shift out the low order 
+                  bit designated to determine if we are in 64BIT mode.
+                  This is necessary for CTOA stubs.
+                  Otherwise we leap one byte past where we want to 
+                  go to in the TPF pat stub linkage code.  */
+               shifter = *((unsigned long int *) 
+                     (stackptr + RA_OFFSET));
+
+               shifter &= ~1ul;
+
+               /* Store Pat Stub Address in destination Stack Frame.  */
+               *((unsigned long int *) (destination_frame +
+                   RA_OFFSET)) = shifter;               
+
+               /* Re-adjust pat stub address to go to correct place
+                  in linkage.  */
+               shifter = shifter - 4;
+
+               return (void *) shifter;
+             }
+
+          /* Desired module pat stub not found ...
+             Bump stack frame iterator.  */
+          stackptr = (void *) *(unsigned long int *) stackptr;
+
+          is_a_stub = 0;
+
+        }  while (stackptr && retval != INVALID_RETURN
+                && targetcodeInfo.dli_fbase != currentcodeInfo.dli_fbase);
+    }
+
+  /* No pat stub found, could be a problem?  Simply return unmodified
+     target address.  */
+  return target;
+}
+