diff libgcc/unwind.inc @ 111:04ced10e8804

gcc 7
author kono
date Fri, 27 Oct 2017 22:46:09 +0900
parents
children 84e7813d76e9
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libgcc/unwind.inc	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,307 @@
+/* Exception handling and frame unwind runtime interface routines. -*- C -*-
+   Copyright (C) 2001-2017 Free Software Foundation, Inc.
+
+   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/>.  */
+
+/* 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, unwind-sjlj.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.  Usually 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.  */
+      gcc_assert (!match_handler);
+
+      uw_update_context (context, &fs);
+    }
+
+  return code;
+}
+
+/* Raise an exception, passing along the given exception object.  */
+
+_Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE
+_Unwind_RaiseException(struct _Unwind_Exception *exc)
+{
+  struct _Unwind_Context this_context, cur_context;
+  _Unwind_Reason_Code code;
+
+  /* Set up this_context to describe the current stack frame.  */
+  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;
+
+      /* Set up fs to describe the FDE for the caller of cur_context.  The
+	 first time through the loop, that means __cxa_throw.  */
+      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.  Usually 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;
+	}
+
+      /* Update cur_context to describe the same frame as fs.  */
+      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) (_Unwind_Ptr) exc->private_1;
+  void *stop_argument = (void *) (_Unwind_Ptr) exc->private_2;
+  _Unwind_Reason_Code code, stop_code;
+
+  while (1)
+    {
+      _Unwind_FrameState fs;
+      int action;
+
+      /* Set up fs to describe the FDE for the caller of cur_context.  */
+      code = uw_frame_state_for (context, &fs);
+      if (code != _URC_NO_REASON && code != _URC_END_OF_STACK)
+	return _URC_FATAL_PHASE2_ERROR;
+
+      /* Unwind successful.  */
+      action = _UA_FORCE_UNWIND | _UA_CLEANUP_PHASE;
+      if (code == _URC_END_OF_STACK)
+	action |= _UA_END_OF_STACK;
+      stop_code = (*stop) (1, action, 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;
+	}
+
+      /* Update cur_context to describe the same frame as fs, and discard
+	 the previous context if necessary.  */
+      uw_advance_context (context, &fs);
+    }
+
+  return code;
+}
+
+
+/* Raise an exception for forced unwinding.  */
+
+_Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE
+_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 LIBGCC2_UNWIND_ATTRIBUTE
+_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);
+
+  gcc_assert (code == _URC_INSTALL_CONTEXT);
+
+  uw_install_context (&this_context, &cur_context);
+}
+
+
+/* Resume propagation of an FORCE_UNWIND exception, or to rethrow
+   a normal exception that was handled.  */
+
+_Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE
+_Unwind_Resume_or_Rethrow (struct _Unwind_Exception *exc)
+{
+  struct _Unwind_Context this_context, cur_context;
+  _Unwind_Reason_Code code;
+
+  /* Choose between continuing to process _Unwind_RaiseException
+     or _Unwind_ForcedUnwind.  */
+  if (exc->private_1 == 0)
+    return _Unwind_RaiseException (exc);
+
+  uw_init_context (&this_context);
+  cur_context = this_context;
+
+  code = _Unwind_ForcedUnwind_Phase2 (exc, &cur_context);
+
+  gcc_assert (code == _URC_INSTALL_CONTEXT);
+
+  uw_install_context (&this_context, &cur_context);
+}
+
+
+/* A convenience function that calls the exception_cleanup field.  */
+
+void
+_Unwind_DeleteException (struct _Unwind_Exception *exc)
+{
+  if (exc->exception_cleanup)
+    (*exc->exception_cleanup) (_URC_FOREIGN_EXCEPTION_CAUGHT, exc);
+}
+
+
+/* Perform stack backtrace through unwind data.  */
+
+_Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE
+_Unwind_Backtrace(_Unwind_Trace_Fn trace, void * trace_argument)
+{
+  struct _Unwind_Context context;
+  _Unwind_Reason_Code code;
+
+  uw_init_context (&context);
+
+  while (1)
+    {
+      _Unwind_FrameState fs;
+
+      /* Set up fs to describe the FDE for the caller of context.  */
+      code = uw_frame_state_for (&context, &fs);
+      if (code != _URC_NO_REASON && code != _URC_END_OF_STACK)
+	return _URC_FATAL_PHASE1_ERROR;
+
+      /* Call trace function.  */
+      if ((*trace) (&context, trace_argument) != _URC_NO_REASON)
+	return _URC_FATAL_PHASE1_ERROR;
+
+      /* We're done at end of stack.  */	
+      if (code == _URC_END_OF_STACK)
+	break;
+
+      /* Update context to describe the same frame as fs.  */
+      uw_update_context (&context, &fs);
+    }
+
+  return code;
+}