gdb/arch/riscv.c

   1 /* Copyright (C) 2018-2019 Free Software Foundation, Inc.
   2
   3    This file is part of GDB.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 #include "gdbsupport/common-defs.h"
  19 #include "riscv.h"
  20 #include <stdlib.h>
  21 #include <unordered_map>
  22
  23 #include "../features/riscv/32bit-cpu.c"
  24 #include "../features/riscv/64bit-cpu.c"
  25 #include "../features/riscv/32bit-fpu.c"
  26 #include "../features/riscv/64bit-fpu.c"
  27
  28 /* Wrapper used by std::unordered_map to generate hash for feature set.  */
  29 struct riscv_gdbarch_features_hasher
  30 {
  31   std::size_t
  32   operator() (const riscv_gdbarch_features &features) const noexcept
  33   {
  34     return features.hash ();
  35   }
  36 };
  37
  38 /* Cache of previously seen target descriptions, indexed by the feature set
  39    that created them.  */
  40 static std::unordered_map<riscv_gdbarch_features,
  41                           target_desc *,
  42                           riscv_gdbarch_features_hasher> riscv_tdesc_cache;
  43
  44 /* See arch/riscv.h.  */
  45
  46 const target_desc *
  47 riscv_create_target_description (struct riscv_gdbarch_features features)
  48 {
  49   /* Have we seen this feature set before?  If we have return the same
  50      target description.  GDB expects that if two target descriptions are
  51      the same (in content terms) then they will actually be the same
  52      instance.  This is important when trying to lookup gdbarch objects as
  53      GDBARCH_LIST_LOOKUP_BY_INFO performs a pointer comparison on target
  54      descriptions to find candidate gdbarch objects.  */
  55   const auto it = riscv_tdesc_cache.find (features);
  56   if (it != riscv_tdesc_cache.end ())
  57     return it->second;
  58
  59   /* Now we should create a new target description.  */
  60   target_desc *tdesc = allocate_target_description ();
  61
  62 #ifndef IN_PROCESS_AGENT
  63   std::string arch_name = "riscv";
  64
  65   if (features.xlen == 4)
  66     arch_name.append (":rv32i");
  67   else if (features.xlen == 8)
  68     arch_name.append (":rv64i");
  69   else if (features.xlen == 16)
  70     arch_name.append (":rv128i");
  71
  72   if (features.flen == 4)
  73     arch_name.append ("f");
  74   else if (features.flen == 8)
  75     arch_name.append ("d");
  76   else if (features.flen == 16)
  77     arch_name.append ("q");
  78
  79   set_tdesc_architecture (tdesc, arch_name.c_str ());
  80 #endif
  81
  82   long regnum = 0;
  83
  84   /* For now we only support creating 32-bit or 64-bit x-registers.  */
  85   if (features.xlen == 4)
  86     regnum = create_feature_riscv_32bit_cpu (tdesc, regnum);
  87   else if (features.xlen == 8)
  88     regnum = create_feature_riscv_64bit_cpu (tdesc, regnum);
  89
  90   /* For now we only support creating 32-bit or 64-bit f-registers.  */
  91   if (features.flen == 4)
  92     regnum = create_feature_riscv_32bit_fpu (tdesc, regnum);
  93   else if (features.flen == 8)
  94     regnum = create_feature_riscv_64bit_fpu (tdesc, regnum);
  95
  96   /* Add to the cache.  */
  97   riscv_tdesc_cache.emplace (features, tdesc);
  98
  99   return tdesc;
 100 }