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       1                 :            : /* Function return value location for Linux/SH ABI.
       2                 :            :    Copyright (C) 2010, 2014 Red Hat, Inc.
       3                 :            :    This file is part of elfutils.
       4                 :            :    Contributed by Matt Fleming <matt@console-pimps.org>.
       5                 :            : 
       6                 :            :    This file is free software; you can redistribute it and/or modify
       7                 :            :    it under the terms of either
       8                 :            : 
       9                 :            :      * the GNU Lesser General Public License as published by the Free
      10                 :            :        Software Foundation; either version 3 of the License, or (at
      11                 :            :        your option) any later version
      12                 :            : 
      13                 :            :    or
      14                 :            : 
      15                 :            :      * the GNU General Public License as published by the Free
      16                 :            :        Software Foundation; either version 2 of the License, or (at
      17                 :            :        your option) any later version
      18                 :            : 
      19                 :            :    or both in parallel, as here.
      20                 :            : 
      21                 :            :    elfutils is distributed in the hope that it will be useful, but
      22                 :            :    WITHOUT ANY WARRANTY; without even the implied warranty of
      23                 :            :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      24                 :            :    General Public License for more details.
      25                 :            : 
      26                 :            :    You should have received copies of the GNU General Public License and
      27                 :            :    the GNU Lesser General Public License along with this program.  If
      28                 :            :    not, see <http://www.gnu.org/licenses/>.  */
      29                 :            : 
      30                 :            : #ifdef HAVE_CONFIG_H
      31                 :            : # include <config.h>
      32                 :            : #endif
      33                 :            : 
      34                 :            : #include <assert.h>
      35                 :            : #include <dwarf.h>
      36                 :            : 
      37                 :            : #define BACKEND sh_
      38                 :            : #include "libebl_CPU.h"
      39                 :            : 
      40                 :            : 
      41                 :            : /* This is the SVR4 ELF ABI convention, but AIX and Linux do not use it.  */
      42                 :            : #define SVR4_STRUCT_RETURN 0
      43                 :            : 
      44                 :            : 
      45                 :            : /* r0, or pair r0, r1.  */
      46                 :            : static const Dwarf_Op loc_intreg[] =
      47                 :            :   {
      48                 :            :     { .atom = DW_OP_reg0 }, { .atom = DW_OP_piece, .number = 4 },
      49                 :            :     { .atom = DW_OP_reg1 }, { .atom = DW_OP_piece, .number = 4 },
      50                 :            :   };
      51                 :            : #define nloc_intreg     1
      52                 :            : #define nloc_intregpair 4
      53                 :            : 
      54                 :            : /* fr0 or fr1.  */
      55                 :            : static const Dwarf_Op loc_fpreg[] =
      56                 :            :   {
      57                 :            :     { .atom = DW_OP_reg25 }, { .atom = DW_OP_piece, .number = 4 },
      58                 :            :     { .atom = DW_OP_reg26 }, { .atom = DW_OP_piece, .number = 4 },
      59                 :            :   };
      60                 :            : #define nloc_fpreg      1
      61                 :            : #define nloc_fpregpair  2
      62                 :            : 
      63                 :            : int
      64                 :          0 : sh_return_value_location (Dwarf_Die *functypedie, const Dwarf_Op **locp)
      65                 :            : {
      66                 :            :   /* Start with the function's type, and get the DW_AT_type attribute,
      67                 :            :      which is the type of the return value.  */
      68                 :          0 :   Dwarf_Die die_mem, *typedie = &die_mem;
      69                 :          0 :   int tag = dwarf_peeled_die_type (functypedie, typedie);
      70         [ #  # ]:          0 :   if (tag <= 0)
      71                 :            :     return tag;
      72                 :            : 
      73                 :          0 :   Dwarf_Word size;
      74      [ #  #  # ]:          0 :   switch (tag)
      75                 :            :     {
      76                 :            :     case -1:
      77                 :            :       return -1;
      78                 :            : 
      79                 :          0 :     case DW_TAG_subrange_type:
      80         [ #  # ]:          0 :       if (! dwarf_hasattr_integrate (typedie, DW_AT_byte_size))
      81                 :            :         {
      82                 :          0 :           Dwarf_Attribute attr_mem, *attr;
      83                 :          0 :           attr = dwarf_attr_integrate (typedie, DW_AT_type, &attr_mem);
      84                 :          0 :           typedie = dwarf_formref_die (attr, &die_mem);
      85         [ #  # ]:          0 :           tag = DWARF_TAG_OR_RETURN (typedie);
      86                 :            :         }
      87                 :          0 :       FALLTHROUGH;
      88                 :            : 
      89                 :            :     case DW_TAG_base_type:
      90                 :            :     case DW_TAG_enumeration_type:
      91                 :            :     CASE_POINTER:
      92                 :            :       {
      93                 :          0 :         Dwarf_Attribute attr_mem;
      94         [ #  # ]:          0 :         if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_byte_size,
      95                 :            :                                                    &attr_mem), &size) != 0)
      96                 :            :           {
      97         [ #  # ]:          0 :             if (dwarf_is_pointer (tag))
      98                 :          0 :               size = 4;
      99                 :            :             else
     100                 :          0 :               return -1;
     101                 :            :           }
     102                 :            :       }
     103                 :            : 
     104         [ #  # ]:          0 :       if (size <= 8)
     105                 :            :         {
     106         [ #  # ]:          0 :           if (tag == DW_TAG_base_type)
     107                 :            :             {
     108                 :          0 :               Dwarf_Attribute attr_mem;
     109                 :          0 :               Dwarf_Word encoding;
     110         [ #  # ]:          0 :               if (dwarf_formudata (dwarf_attr_integrate (typedie,
     111                 :            :                                                          DW_AT_encoding,
     112                 :            :                                                          &attr_mem),
     113                 :            :                                    &encoding) != 0)
     114                 :          0 :                 return -1;
     115         [ #  # ]:          0 :               if (encoding == DW_ATE_float)
     116                 :            :                 {
     117                 :          0 :                   *locp = loc_fpreg;
     118         [ #  # ]:          0 :                   return size <= 4 ? nloc_fpreg : nloc_fpregpair;
     119                 :            :                 }
     120                 :            :             }
     121                 :          0 :           *locp = loc_intreg;
     122         [ #  # ]:          0 :           return size <= 4 ? nloc_intreg : nloc_intregpair;
     123                 :            :         }
     124                 :            :     }
     125                 :            : 
     126                 :            :   /* XXX We don't have a good way to return specific errors from ebl calls.
     127                 :            :      This value means we do not understand the type, but it is well-formed
     128                 :            :      DWARF and might be valid.  */
     129                 :            :   return -2;
     130                 :            : }