gdb/arch/arc.c

   1 /* Copyright (C) 2017-2021 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
  19 #include "gdbsupport/common-defs.h"
  20 #include "arc.h"
  21 #include <stdlib.h>
  22 #include <unordered_map>
  23 #include <string>
  24
  25 /* Target description features.  */
  26 #include "features/arc/v1-core.c"
  27 #include "features/arc/v1-aux.c"
  28 #include "features/arc/v2-core.c"
  29 #include "features/arc/v2-aux.c"
  30
  31 #ifndef GDBSERVER
  32 #define STATIC_IN_GDB static
  33 #else
  34 #define STATIC_IN_GDB
  35 #endif
  36
  37 STATIC_IN_GDB target_desc_up
  38 arc_create_target_description (const struct arc_arch_features &features)
  39 {
  40   /* Create a new target description.  */
  41   target_desc_up tdesc = allocate_target_description ();
  42
  43 #ifndef IN_PROCESS_AGENT
  44   std::string arch_name;
  45
  46   /* Architecture names here must match the ones in
  47      ARCH_INFO_STRUCT in bfd/cpu-arc.c.  */
  48   if (features.isa == ARC_ISA_ARCV1 && features.reg_size == 4)
  49       arch_name = "arc:ARC700";
  50   else if (features.isa == ARC_ISA_ARCV2 && features.reg_size == 4)
  51       arch_name = "arc:ARCv2";
  52   else
  53     {
  54       std::string msg = string_printf
  55         ("Cannot determine architecture: ISA=%d; bitness=%d",
  56          features.isa, 8 * features.reg_size);
  57       gdb_assert_not_reached (msg.c_str ());
  58     }
  59
  60   set_tdesc_architecture (tdesc.get (), arch_name.c_str ());
  61 #endif
  62
  63   long regnum = 0;
  64
  65   switch (features.isa)
  66     {
  67     case ARC_ISA_ARCV1:
  68       regnum = create_feature_arc_v1_core (tdesc.get (), regnum);
  69       regnum = create_feature_arc_v1_aux (tdesc.get (), regnum);
  70       break;
  71     case ARC_ISA_ARCV2:
  72       regnum = create_feature_arc_v2_core (tdesc.get (), regnum);
  73       regnum = create_feature_arc_v2_aux (tdesc.get (), regnum);
  74       break;
  75     default:
  76       std::string msg = string_printf
  77         ("Cannot choose target description XML: %d", features.isa);
  78       gdb_assert_not_reached (msg.c_str ());
  79     }
  80
  81   return tdesc;
  82 }
  83
  84 #ifndef GDBSERVER
  85
  86 /* Wrapper used by std::unordered_map to generate hash for features set.  */
  87 struct arc_arch_features_hasher
  88 {
  89   std::size_t
  90   operator() (const arc_arch_features &features) const noexcept
  91   {
  92     return features.hash ();
  93   }
  94 };
  95
  96 /* Cache of previously created target descriptions, indexed by the hash
  97    of the features set used to create them.  */
  98 static std::unordered_map<arc_arch_features,
  99                           const target_desc_up,
 100                           arc_arch_features_hasher> arc_tdesc_cache;
 101
 102 /* See arch/arc.h.  */
 103
 104 const target_desc *
 105 arc_lookup_target_description (const struct arc_arch_features &features)
 106 {
 107   /* Lookup in the cache first.  If found, return the pointer from the
 108      "target_desc_up" type which is a "unique_ptr".  This should be fine
 109      as the "arc_tdesc_cache" will persist until GDB terminates.  */
 110   const auto it = arc_tdesc_cache.find (features);
 111   if (it != arc_tdesc_cache.end ())
 112     return it->second.get ();
 113
 114   target_desc_up tdesc = arc_create_target_description (features);
 115
 116
 117   /* Add to the cache, and return a pointer borrowed from the
 118      target_desc_up.  This is safe as the cache (and the pointers
 119      contained within it) are not deleted until GDB exits.  */
 120   target_desc *ptr = tdesc.get ();
 121   arc_tdesc_cache.emplace (features, std::move (tdesc));
 122   return ptr;
 123 }
 124
 125 #endif /* !GDBSERVER */