IA-64 ABI Exception Handling.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@40924 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 232 insertions, 0 deletions

diff --git a/gcc/unwind.inc b/gcc/unwind.inc
new file mode 100644
index 00000000000..ba315361309
--- /dev/null
+++ b/gcc/unwind.inc
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+/* Exception handling and frame unwind runtime interface routines.
+   Copyright (C) 2001 Free Software Foundation, Inc.
+
+   This file is part of GNU CC.
+
+   GNU CC 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 2, or (at your option)
+   any later version.
+
+   GNU CC 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.
+
+   You should have received a copy of the GNU General Public License
+   along with GNU CC; see the file COPYING.  If not, write to
+   the Free Software Foundation, 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+/* This is derived from the C++ ABI for IA-64.  Where we diverge
+   for cross-architecture compatibility are noted with "@@@".  
+   This file is included from unwind-dw2.c or unwind-ia64.c.  */
+
+/* Subroutine of _Unwind_RaiseException also invoked from _Unwind_Resume. 
+
+   Unwind the stack calling the personality routine to find both the
+   exception handler and intermediary cleanup code.  We'll only locate
+   the first such frame here.  Cleanup code will call back into
+   _Unwind_Resume and we'll continue Phase 2 there.  */
+
+static _Unwind_Reason_Code
+_Unwind_RaiseException_Phase2(struct _Unwind_Exception *exc,
+			      struct _Unwind_Context *context)
+{
+  _Unwind_Reason_Code code;
+
+  while (1)
+    {
+      _Unwind_FrameState fs;
+      int match_handler;
+
+      code = uw_frame_state_for (context, &fs);
+
+      /* Identify when we've reached the designated handler context.  */
+      match_handler = (uw_identify_context (context) == exc->private_2
+		       ? _UA_HANDLER_FRAME : 0);
+
+      if (code != _URC_NO_REASON)
+	/* Some error encountered.  Ususally the unwinder doesn't
+	   diagnose these and merely crashes.  */
+	return _URC_FATAL_PHASE2_ERROR;
+
+      /* Unwind successful.  Run the personality routine, if any.  */
+      if (fs.personality)
+	{
+	  code = (*fs.personality) (1, _UA_CLEANUP_PHASE | match_handler,
+				    exc->exception_class, exc, context);
+	  if (code == _URC_INSTALL_CONTEXT)
+	    break;
+	  if (code != _URC_CONTINUE_UNWIND) 
+	    return _URC_FATAL_PHASE2_ERROR;
+	}
+
+      /* Don't let us unwind past the handler context.  */
+      if (match_handler)
+	abort ();
+
+      uw_update_context (context, &fs);
+    }
+
+  return code;
+}
+
+
+/* Raise an exception, passing along the given exception object.  */
+
+_Unwind_Reason_Code
+_Unwind_RaiseException(struct _Unwind_Exception *exc)
+{
+  struct _Unwind_Context this_context, cur_context;
+  _Unwind_Reason_Code code;
+
+  uw_init_context (&this_context);
+  cur_context = this_context;
+
+  /* Phase 1: Search.  Unwind the stack, calling the personality routine
+     with the _UA_SEARCH_PHASE flag set.  Do not modify the stack yet.  */
+  while (1)
+    {
+      _Unwind_FrameState fs;
+
+      code = uw_frame_state_for (&cur_context, &fs);
+
+      if (code == _URC_END_OF_STACK)
+	/* Hit end of stack with no handler found.  */
+	return _URC_END_OF_STACK;
+
+      if (code != _URC_NO_REASON)
+	/* Some error encountered.  Ususally the unwinder doesn't
+	   diagnose these and merely crashes.  */
+	return _URC_FATAL_PHASE1_ERROR;
+
+      /* Unwind successful.  Run the personality routine, if any.  */
+      if (fs.personality)
+	{
+	  code = (*fs.personality) (1, _UA_SEARCH_PHASE, exc->exception_class,
+				    exc, &cur_context);
+	  if (code == _URC_HANDLER_FOUND)
+	    break;
+	  else if (code != _URC_CONTINUE_UNWIND)
+	    return _URC_FATAL_PHASE1_ERROR;
+	}
+
+      uw_update_context (&cur_context, &fs);
+    }
+
+  /* Indicate to _Unwind_Resume and associated subroutines that this
+     is not a forced unwind.  Further, note where we found a handler.  */
+  exc->private_1 = 0;
+  exc->private_2 = uw_identify_context (&cur_context);
+
+  cur_context = this_context;
+  code = _Unwind_RaiseException_Phase2 (exc, &cur_context);
+  if (code != _URC_INSTALL_CONTEXT)
+    return code;
+
+  uw_install_context (&this_context, &cur_context);
+}
+
+
+/* Subroutine of _Unwind_ForcedUnwind also invoked from _Unwind_Resume.  */
+
+static _Unwind_Reason_Code
+_Unwind_ForcedUnwind_Phase2(struct _Unwind_Exception *exc,
+			    struct _Unwind_Context *context)
+{
+  _Unwind_Stop_Fn stop = (_Unwind_Stop_Fn) exc->private_1;
+  void *stop_argument = (void *) exc->private_2;
+  _Unwind_Reason_Code code, stop_code;
+
+  while (1)
+    {
+      _Unwind_FrameState fs;
+
+      code = uw_frame_state_for (context, &fs);
+      if (code != _URC_NO_REASON && code != _URC_END_OF_STACK)
+	return _URC_FATAL_PHASE2_ERROR;
+
+      /* Unwind successful.  */
+      stop_code = (*stop) (1, _UA_FORCE_UNWIND | _UA_CLEANUP_PHASE,
+			   exc->exception_class, exc, context, stop_argument);
+      if (stop_code != _URC_NO_REASON)
+	return _URC_FATAL_PHASE2_ERROR;
+
+      /* Stop didn't want to do anything.  Invoke the personality
+	 handler, if applicable, to run cleanups.  */
+      if (code == _URC_END_OF_STACK)
+	break;
+	
+      if (fs.personality)
+	{
+	  code = (*fs.personality) (1, _UA_FORCE_UNWIND | _UA_CLEANUP_PHASE,
+				    exc->exception_class, exc, context);
+	  if (code == _URC_INSTALL_CONTEXT)
+	    break;
+	  if (code != _URC_CONTINUE_UNWIND) 
+	    return _URC_FATAL_PHASE2_ERROR;
+	}
+
+      uw_update_context (context, &fs);
+    }
+
+  return code;
+}
+
+
+/* Raise an exception for forced unwinding.  */
+
+_Unwind_Reason_Code
+_Unwind_ForcedUnwind (struct _Unwind_Exception *exc,
+		      _Unwind_Stop_Fn stop, void * stop_argument)
+{
+  struct _Unwind_Context this_context, cur_context;
+  _Unwind_Reason_Code code;
+
+  uw_init_context (&this_context);
+  cur_context = this_context;
+
+  exc->private_1 = (_Unwind_Ptr) stop;
+  exc->private_2 = (_Unwind_Ptr) stop_argument;
+
+  code = _Unwind_ForcedUnwind_Phase2 (exc, &cur_context);
+  if (code != _URC_INSTALL_CONTEXT)
+    return code;
+
+  uw_install_context (&this_context, &cur_context);
+}
+
+
+/* Resume propagation of an existing exception.  This is used after
+   e.g. executing cleanup code, and not to implement rethrowing.  */
+
+void
+_Unwind_Resume (struct _Unwind_Exception *exc)
+{
+  struct _Unwind_Context this_context, cur_context;
+  _Unwind_Reason_Code code;
+
+  uw_init_context (&this_context);
+  cur_context = this_context;
+
+  /* Choose between continuing to process _Unwind_RaiseException
+     or _Unwind_ForcedUnwind.  */
+  if (exc->private_1 == 0)
+    code = _Unwind_RaiseException_Phase2 (exc, &cur_context);
+  else
+    code = _Unwind_ForcedUnwind_Phase2 (exc, &cur_context);
+
+  if (code != _URC_INSTALL_CONTEXT)
+    abort ();
+
+  uw_install_context (&this_context, &cur_context);
+}
+
+/* A convenience function that calls the exception_cleanup field.  */
+
+void
+_Unwind_DeleteException (struct _Unwind_Exception *exc)
+{
+  (*exc->exception_cleanup) (_URC_FOREIGN_EXCEPTION_CAUGHT, exc);
+}