Home | History | Annotate | Download | only in libdw
      1 /* Get CFA expression for frame.
      2    Copyright (C) 2009-2010 Red Hat, Inc.
      3    This file is part of elfutils.
      4 
      5    This file is free software; you can redistribute it and/or modify
      6    it under the terms of either
      7 
      8      * the GNU Lesser General Public License as published by the Free
      9        Software Foundation; either version 3 of the License, or (at
     10        your option) any later version
     11 
     12    or
     13 
     14      * the GNU General Public License as published by the Free
     15        Software Foundation; either version 2 of the License, or (at
     16        your option) any later version
     17 
     18    or both in parallel, as here.
     19 
     20    elfutils is distributed in the hope that it will be useful, but
     21    WITHOUT ANY WARRANTY; without even the implied warranty of
     22    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     23    General Public License for more details.
     24 
     25    You should have received copies of the GNU General Public License and
     26    the GNU Lesser General Public License along with this program.  If
     27    not, see <http://www.gnu.org/licenses/>.  */
     28 
     29 #ifdef HAVE_CONFIG_H
     30 # include <config.h>
     31 #endif
     32 
     33 #include "cfi.h"
     34 #include <dwarf.h>
     35 #include <stdlib.h>
     36 
     37 int
     38 dwarf_frame_cfa (Dwarf_Frame *fs, Dwarf_Op **ops, size_t *nops)
     39 {
     40   /* Maybe there was a previous error.  */
     41   if (fs == NULL)
     42     return -1;
     43 
     44   int result = 0;
     45   switch (fs->cfa_rule)
     46     {
     47     case cfa_undefined:
     48       *ops = NULL;
     49       *nops = 0;
     50       break;
     51 
     52     case cfa_offset:
     53       /* The Dwarf_Op was already fully initialized by execute_cfi.  */
     54       *ops = &fs->cfa_data.offset;
     55       *nops = 1;
     56       break;
     57 
     58     case cfa_expr:
     59       /* Parse the expression into internal form.  */
     60       result = __libdw_intern_expression
     61 	(NULL, fs->cache->other_byte_order,
     62 	 fs->cache->e_ident[EI_CLASS] == ELFCLASS32 ? 4 : 8, 4,
     63 	 &fs->cache->expr_tree, &fs->cfa_data.expr, false, false,
     64 	 ops, nops, IDX_debug_frame);
     65       break;
     66 
     67     case cfa_invalid:
     68       __libdw_seterrno (DWARF_E_INVALID_CFI);
     69       result = -1;
     70       break;
     71 
     72     default:
     73       abort ();
     74     }
     75 
     76   return result;
     77 }
     78