gdb/arch/loongarch.h

   1 /* Common target-dependent functionality for LoongArch
   2
   3    Copyright (C) 2022 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   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, see <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef ARCH_LOONGARCH_H
  21 #define ARCH_LOONGARCH_H
  22
  23 #include "gdbsupport/tdesc.h"
  24
  25 /* The set of LoongArch architectural features that we track that impact how
  26    we configure the actual gdbarch instance.  We hold one of these in the
  27    gdbarch_tdep structure, and use it to distinguish between different
  28    LoongArch gdbarch instances.
  29
  30    The information in here ideally comes from the target description,
  31    however, if the target doesn't provide a target description then we will
  32    create a default target description by first populating one of these
  33    based on what we know about the binary being executed, and using that to
  34    drive default target description creation.  */
  35
  36 struct loongarch_gdbarch_features
  37 {
  38   /* The size of the x-registers in bytes.  This is either 4 (loongarch32)
  39      or 8 (loongarch64).  No other value is valid.  Initialise to the invalid
  40      0 value so we can spot if one of these is used uninitialised.  */
  41   int xlen = 0;
  42
  43   /* Equality operator.  */
  44   bool operator== (const struct loongarch_gdbarch_features &rhs) const
  45   {
  46     return (xlen == rhs.xlen);
  47   }
  48
  49   /* Inequality operator.  */
  50   bool operator!= (const struct loongarch_gdbarch_features &rhs) const
  51   {
  52     return !((*this) == rhs);
  53   }
  54
  55   /* Used by std::unordered_map to hash feature sets.  */
  56   std::size_t hash () const noexcept
  57   {
  58     std::size_t val = (xlen & 0x1f) << 5;
  59     return val;
  60   }
  61 };
  62
  63 /* Lookup an already existing target description matching FEATURES, or
  64    create a new target description if this is the first time we have seen
  65    FEATURES.  For the same FEATURES the same target_desc is always
  66    returned.  This is important when trying to lookup gdbarch objects as
  67    GDBARCH_LIST_LOOKUP_BY_INFO performs a pointer comparison on target
  68    descriptions to find candidate gdbarch objects.  */
  69
  70 const target_desc *loongarch_lookup_target_description
  71         (const struct loongarch_gdbarch_features features);
  72
  73 #endif /* ARCH_LOONGARCH_H  */