cpu-arc.c revision 1.6 
1/* BFD support for the ARC processor
2   Copyright (C) 1994-2018 Free Software Foundation, Inc.
3   Contributed by Doug Evans (dje@cygnus.com).
4
5   This file is part of BFD, the Binary File Descriptor library.
6
7   This program is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 3 of the License, or
10   (at your option) any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program; if not, write to the Free Software
19   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
20   MA 02110-1301, USA.  */
21
22#include "sysdep.h"
23#include "bfd.h"
24#include "libbfd.h"
25
26static const bfd_arch_info_type *
27arc_compatible (const bfd_arch_info_type *a, const bfd_arch_info_type *b);
28
29#define ARC(mach, print_name, default_p, next) \
30{					\
31    32,	/* 32 bits in a word  */	\
32    32,	/* 32 bits in an address  */	\
33    8,	/* 8 bits in a byte  */		\
34    bfd_arch_arc,			\
35    mach,				\
36    "arc",				\
37    print_name,				\
38    4, /* section alignment power  */	\
39    default_p,				\
40    arc_compatible,			\
41    bfd_default_scan,			\
42    bfd_arch_default_fill,		\
43    next,				\
44  }
45
46static const bfd_arch_info_type arch_info_struct[] =
47{
48  ARC (bfd_mach_arc_arc600, "A6"    , FALSE, &arch_info_struct[1]),
49  ARC (bfd_mach_arc_arc601, "ARC601", FALSE, &arch_info_struct[2]),
50  ARC (bfd_mach_arc_arc700, "ARC700", FALSE, &arch_info_struct[3]),
51  ARC (bfd_mach_arc_arc700, "A7",     FALSE, &arch_info_struct[4]),
52  ARC (bfd_mach_arc_arcv2,  "ARCv2",  FALSE, &arch_info_struct[5]),
53  ARC (bfd_mach_arc_arcv2,  "EM",     FALSE, &arch_info_struct[6]),
54  ARC (bfd_mach_arc_arcv2,  "HS",     FALSE, NULL),
55};
56
57const bfd_arch_info_type bfd_arc_arch =
58  ARC (bfd_mach_arc_arc600, "ARC600", TRUE, &arch_info_struct[0]);
59
60/* ARC-specific "compatible" function.  The general rule is that if A and B are
61   compatible, then this function should return architecture that is more
62   "feature-rich", that is, can run both A and B.  ARCv2, EM and HS all has
63   same mach number, so bfd_default_compatible assumes they are the same, and
64   returns an A.  That causes issues with GDB, because GDB assumes that if
65   machines are compatible, then "compatible ()" always returns same machine
66   regardless of argument order.  As a result GDB gets confused because, for
67   example, compatible (ARCv2, EM) returns ARCv2, but compatible (EM, ARCv2)
68   returns EM, hence GDB is not sure if they are compatible and prints a
69   warning.  */
70
71static const bfd_arch_info_type *
72arc_compatible (const bfd_arch_info_type *a, const bfd_arch_info_type *b)
73{
74  const bfd_arch_info_type * const em = &arch_info_struct[5];
75  const bfd_arch_info_type * const hs = &arch_info_struct[6];
76
77  /* Trivial case where a and b is the same instance.  Some callers already
78     check this condition but some do not and get an invalid result.  */
79  if (a == b)
80    return a;
81
82  /* If a & b are for different architecture we can do nothing.  */
83  if (a->arch != b->arch)
84    return NULL;
85
86  if (a->bits_per_word != b->bits_per_word)
87    return NULL;
88
89  /* ARCv2|EM and EM.  */
90  if ((a->mach == bfd_mach_arc_arcv2 && b == em)
91      || (b->mach == bfd_mach_arc_arcv2 && a == em))
92    return em;
93
94  /* ARCv2|HS and HS.  */
95  if ((a->mach == bfd_mach_arc_arcv2 && b == hs)
96      || (b->mach == bfd_mach_arc_arcv2 && a == hs))
97    return hs;
98
99  return bfd_default_compatible (a, b);
100}
101