2009-05-08 Tobias Burnus <burnus@net-b.de>

[pf3gnuchains/gcc-fork.git] / gcc / unwind-dw2.c

diff --git a/gcc/unwind-dw2.c b/gcc/unwind-dw2.c
index 3845467..dd3dd54 100644 (file)
--- a/gcc/unwind-dw2.c
+++ b/gcc/unwind-dw2.c
@@ -1,32 +1,27 @@
 /* DWARF2 exception handling and frame unwind runtime interface routines.
    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
-   2008  Free Software Foundation, Inc.
+   2008, 2009  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 2, or (at your option)
+   the Free Software Foundation; either version 3, or (at your option)
    any later version.
 
-   In addition to the permissions in the GNU General Public License, the
-   Free Software Foundation gives you unlimited permission to link the
-   compiled version of this file into combinations with other programs,
-   and to distribute those combinations without any restriction coming
-   from the use of this file.  (The General Public License restrictions
-   do apply in other respects; for example, they cover modification of
-   the file, and distribution when not linked into a combined
-   executable.)
-
    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.
 
-   You should have received a copy of the GNU General Public License
-   along with GCC; see the file COPYING.  If not, write to the Free
-   Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
-   02110-1301, USA.  */
+   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 "tconfig.h"
 #include "tsystem.h"
@@ -943,12 +938,16 @@ execute_cfa_program (const unsigned char *insn_ptr,
          fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN(reg)].how = REG_UNSAVED;
          break;
 
-       case DW_CFA_undefined:
        case DW_CFA_same_value:
          insn_ptr = read_uleb128 (insn_ptr, &reg);
          fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN(reg)].how = REG_UNSAVED;
          break;
 
+       case DW_CFA_undefined:
+         insn_ptr = read_uleb128 (insn_ptr, &reg);
+         fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN(reg)].how = REG_UNDEFINED;
+         break;
+
        case DW_CFA_nop:
          break;
 
@@ -1319,6 +1318,7 @@ uw_update_context_1 (struct _Unwind_Context *context, _Unwind_FrameState *fs)
     switch (fs->regs.reg[i].how)
       {
       case REG_UNSAVED:
+      case REG_UNDEFINED:
        break;
 
       case REG_SAVED_OFFSET:
@@ -1387,10 +1387,22 @@ uw_update_context (struct _Unwind_Context *context, _Unwind_FrameState *fs)
 {
   uw_update_context_1 (context, fs);
 
-  /* Compute the return address now, since the return address column
-     can change from frame to frame.  */
-  context->ra = __builtin_extract_return_addr
-    (_Unwind_GetPtr (context, fs->retaddr_column));
+  /* In general this unwinder doesn't make any distinction between
+     undefined and same_value rule.  Call-saved registers are assumed
+     to have same_value rule by default and explicit undefined
+     rule is handled like same_value.  The only exception is
+     DW_CFA_undefined on retaddr_column which is supposed to
+     mark outermost frame in DWARF 3.  */
+  if (fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (fs->retaddr_column)].how
+      == REG_UNDEFINED)
+    /* uw_frame_state_for uses context->ra == 0 check to find outermost
+       stack frame.  */
+    context->ra = 0;
+  else
+    /* Compute the return address now, since the return address column
+       can change from frame to frame.  */
+    context->ra = __builtin_extract_return_addr
+      (_Unwind_GetPtr (context, fs->retaddr_column));
 }
 
 static void