binutils-gdb/bfd/cpu-arc.c

/* BFD support for the ARC processor
   Copyright (C) 1994-2023 Free Software Foundation, Inc.
   Contributed by Doug Evans (dje@cygnus.com).

   This file is part of BFD, the Binary File Descriptor library.

   This program 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 of the License, or
   (at your option) any later version.

   This program 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 this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
   MA 02110-1301, USA.  */

#include "sysdep.h"
#include "bfd.h"
#include "libbfd.h"

static const bfd_arch_info_type *
arc_compatible (const bfd_arch_info_type *a, const bfd_arch_info_type *b);

#define ARC(BITS_WORD, BITS_ADDR, MACH, PRINT_NAME, DEFAULT_P, NEXT)	\
{									\
    BITS_WORD,	/* 32 bits in a word.  */				\
    BITS_ADDR,	/* 32 bits in an address.  */				\
    8,	/* 8 bits in a byte.  */				\
    bfd_arch_arc,							\
    MACH,								\
    "arc",								\
    PRINT_NAME,								\
    4, /* section alignment power.  */					\
    DEFAULT_P,								\
    arc_compatible,							\
    bfd_default_scan,							\
    bfd_arch_default_fill,						\
    NEXT,								\
    0 /* Maximum offset of a reloc from the start of an insn.  */	\
}

static const bfd_arch_info_type arch_info_struct[] =
{
  ARC (32, 32, bfd_mach_arc_arc600, "A6"    , false, &arch_info_struct[1]),
  ARC (32, 32, bfd_mach_arc_arc601, "ARC601", false, &arch_info_struct[2]),
  ARC (32, 32, bfd_mach_arc_arc700, "ARC700", false, &arch_info_struct[3]),
  ARC (32, 32, bfd_mach_arc_arc700, "A7",     false, &arch_info_struct[4]),
  ARC (32, 32, bfd_mach_arc_arcv2,  "ARCv2",  false, &arch_info_struct[5]),
  ARC (32, 32, bfd_mach_arc_arcv2,  "EM",     false, &arch_info_struct[6]),
  ARC (32, 32, bfd_mach_arc_arcv2,  "HS",     false, NULL),
};

const bfd_arch_info_type bfd_arc_arch =
  ARC (32, 32, bfd_mach_arc_arc600, "ARC600", true, &arch_info_struct[0]);

/* ARC-specific "compatible" function.  The general rule is that if A
   and B are compatible, then this function should return architecture
   that is more "feature-rich", that is, can run both A and B.  ARCv2,
   EM and HS all has same mach number, so bfd_default_compatible
   assumes they are the same, and returns an A.  That causes issues
   with GDB, because GDB assumes that if machines are compatible, then
   "compatible ()" always returns same machine regardless of argument
   order.  As a result GDB gets confused because, for example,
   compatible (ARCv2, EM) returns ARCv2, but compatible (EM, ARCv2)
   returns EM, hence GDB is not sure if they are compatible and prints
   a warning.  */

static const bfd_arch_info_type *
arc_compatible (const bfd_arch_info_type *a ATTRIBUTE_UNUSED,
		const bfd_arch_info_type *b ATTRIBUTE_UNUSED)
{
  const bfd_arch_info_type * const em = &arch_info_struct[5];
  const bfd_arch_info_type * const hs = &arch_info_struct[6];

  /* Trivial case where a and b is the same instance.  Some callers already
     check this condition but some do not and get an invalid result.  */
  if (a == b)
    return a;

  /* If a & b are for different architecture we can do nothing.  */
  if (a->arch != b->arch)
    return NULL;

  /* ARCv2|EM and EM.  */
  if ((a->mach == bfd_mach_arc_arcv2 && b == em)
      || (b->mach == bfd_mach_arc_arcv2 && a == em))
    return em;

  /* ARCv2|HS and HS.  */
  if ((a->mach == bfd_mach_arc_arcv2 && b == hs)
      || (b->mach == bfd_mach_arc_arcv2 && a == hs))
    return hs;

  return bfd_default_compatible (a, b);
}