gcc/cp/cp-lang.c

   1 /* Language-dependent hooks for C++.
   2    Copyright (C) 2001-2018 Free Software Foundation, Inc.
   3    Contributed by Alexandre Oliva  <aoliva@redhat.com>
   4
   5 This file is part of GCC.
   6
   7 GCC 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, or (at your option)
  10 any later version.
  11
  12 GCC 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 GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #include "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "cp-tree.h"
  25 #include "stor-layout.h"
  26 #include "langhooks.h"
  27 #include "langhooks-def.h"
  28 #include "cp-objcp-common.h"
  29
  30 enum c_language_kind c_language = clk_cxx;
  31 static void cp_init_ts (void);
  32 static const char * cxx_dwarf_name (tree t, int verbosity);
  33 static enum classify_record cp_classify_record (tree type);
  34 static tree cp_eh_personality (void);
  35 static tree get_template_innermost_arguments_folded (const_tree);
  36 static tree get_template_argument_pack_elems_folded (const_tree);
  37 static tree cxx_enum_underlying_base_type (const_tree);
  38
  39 /* Lang hooks common to C++ and ObjC++ are declared in cp/cp-objcp-common.h;
  40    consequently, there should be very few hooks below.  */
  41
  42 #undef LANG_HOOKS_NAME
  43 #define LANG_HOOKS_NAME "GNU C++"
  44 #undef LANG_HOOKS_INIT
  45 #define LANG_HOOKS_INIT cxx_init
  46 #undef LANG_HOOKS_CLASSIFY_RECORD
  47 #define LANG_HOOKS_CLASSIFY_RECORD cp_classify_record
  48 #undef LANG_HOOKS_GENERIC_TYPE_P
  49 #define LANG_HOOKS_GENERIC_TYPE_P class_tmpl_impl_spec_p
  50
  51 #undef LANG_HOOKS_GET_INNERMOST_GENERIC_PARMS
  52 #define LANG_HOOKS_GET_INNERMOST_GENERIC_PARMS \
  53         get_primary_template_innermost_parameters
  54 #undef LANG_HOOKS_GET_INNERMOST_GENERIC_ARGS
  55 #define LANG_HOOKS_GET_INNERMOST_GENERIC_ARGS \
  56         get_template_innermost_arguments_folded
  57 #undef LANG_HOOKS_FUNCTION_PARAMETER_PACK_P
  58 #define LANG_HOOKS_FUNCTION_PARAMETER_PACK_P \
  59         function_parameter_pack_p
  60 #undef LANG_HOOKS_GET_ARGUMENT_PACK_ELEMS
  61 #define LANG_HOOKS_GET_ARGUMENT_PACK_ELEMS \
  62         get_template_argument_pack_elems_folded
  63 #undef LANG_HOOKS_GENERIC_GENERIC_PARAMETER_DECL_P
  64 #define LANG_HOOKS_GENERIC_GENERIC_PARAMETER_DECL_P \
  65         template_template_parameter_p
  66 #undef LANG_HOOKS_FUNCTION_PARM_EXPANDED_FROM_PACK_P
  67 #define LANG_HOOKS_FUNCTION_PARM_EXPANDED_FROM_PACK_P \
  68         function_parameter_expanded_from_pack_p
  69 #undef LANG_HOOKS_GET_GENERIC_FUNCTION_DECL
  70 #define LANG_HOOKS_GET_GENERIC_FUNCTION_DECL get_function_template_decl
  71 #undef LANG_HOOKS_DWARF_NAME
  72 #define LANG_HOOKS_DWARF_NAME cxx_dwarf_name
  73 #undef LANG_HOOKS_INIT_TS
  74 #define LANG_HOOKS_INIT_TS cp_init_ts
  75 #undef LANG_HOOKS_EH_PERSONALITY
  76 #define LANG_HOOKS_EH_PERSONALITY cp_eh_personality
  77 #undef LANG_HOOKS_EH_RUNTIME_TYPE
  78 #define LANG_HOOKS_EH_RUNTIME_TYPE build_eh_type_type
  79 #undef LANG_HOOKS_ENUM_UNDERLYING_BASE_TYPE
  80 #define LANG_HOOKS_ENUM_UNDERLYING_BASE_TYPE cxx_enum_underlying_base_type
  81
  82 #if CHECKING_P
  83 #undef LANG_HOOKS_RUN_LANG_SELFTESTS
  84 #define LANG_HOOKS_RUN_LANG_SELFTESTS selftest::run_cp_tests
  85 #endif /* #if CHECKING_P */
  86
  87 /* Each front end provides its own lang hook initializer.  */
  88 struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
  89
  90 /* Lang hook routines common to C++ and ObjC++ appear in cp/cp-objcp-common.c;
  91    there should be very few routines below.  */
  92
  93 /* The following function does something real, but only in Objective-C++.  */
  94
  95 tree
  96 objcp_tsubst_copy_and_build (tree /*t*/,
  97                              tree /*args*/,
  98                              tsubst_flags_t /*complain*/,
  99                              tree /*in_decl*/,
 100                              bool /*function_p*/)
 101 {
 102   return NULL_TREE;
 103 }
 104
 105 static void
 106 cp_init_ts (void)
 107 {
 108   cp_common_init_ts ();
 109
 110   init_shadowed_var_for_decl ();
 111 }
 112
 113 static const char *
 114 cxx_dwarf_name (tree t, int verbosity)
 115 {
 116   gcc_assert (DECL_P (t));
 117
 118   if (DECL_NAME (t)
 119       && (anon_aggrname_p (DECL_NAME (t)) || LAMBDA_TYPE_P (t)))
 120     return NULL;
 121   if (verbosity >= 2)
 122     return decl_as_dwarf_string (t,
 123                                  TFF_DECL_SPECIFIERS | TFF_UNQUALIFIED_NAME
 124                                  | TFF_NO_OMIT_DEFAULT_TEMPLATE_ARGUMENTS);
 125
 126   return lang_decl_dwarf_name (t, verbosity, false);
 127 }
 128
 129 static enum classify_record
 130 cp_classify_record (tree type)
 131 {
 132   if (TYPE_LANG_SPECIFIC (type)
 133       && CLASSTYPE_DECLARED_CLASS (type))
 134     return RECORD_IS_CLASS;
 135
 136   return RECORD_IS_STRUCT;
 137 }
 138
 139 static GTY(()) tree cp_eh_personality_decl;
 140
 141 static tree
 142 cp_eh_personality (void)
 143 {
 144   if (!cp_eh_personality_decl)
 145     cp_eh_personality_decl = build_personality_function ("gxx");
 146
 147   return cp_eh_personality_decl;
 148 }
 149
 150 /* This is a subroutine of fold_cplus_constants.  It returns TRUE if T
 151    is a C++ specific constant that needs to be folded further before
 152    being passed to the debug info emitter.  */
 153
 154 static bool
 155 template_arg_needs_folding (const_tree t)
 156 {
 157   /* For now only PTRMEM_CST nodes are to be folded further.  */
 158   if (TREE_CODE (t) == PTRMEM_CST)
 159     return true;
 160   return false;
 161 }
 162
 163 /* Fold the elements of the TREE_VEC C which are C++ specific nodes
 164    that would need folding so that they can be processed by the debug
 165    info emitter. This is a subroutine of
 166    get_template_innermost_arguments_folded and
 167    get_template_argument_pack_elems_folded.  */
 168
 169 static tree
 170 fold_cplus_constants (const_tree c)
 171 {
 172   tree folded_elems, elems = CONST_CAST_TREE (c);
 173   int vec_len, i;
 174
 175   if (elems == NULL_TREE || elems == error_mark_node)
 176     return elems;
 177
 178   vec_len = TREE_VEC_LENGTH (elems);
 179
 180   /* First check if there is at least one element that needs
 181      folding. If there is none, we just return ELEMS. Otherwise create
 182      and return a new tree vector that contains the folded versions of
 183      ELEMS. This is to avoid allocating memory if we don't need
 184      to.  */
 185   for (i = 0; i < vec_len; ++i)
 186     {
 187       if (template_arg_needs_folding (TREE_VEC_ELT (elems, i)))
 188         break;
 189     }
 190   if (i == vec_len)
 191     return elems;
 192
 193   folded_elems = make_tree_vec (vec_len);
 194   for (i = 0; i < vec_len; ++i)
 195     {
 196       tree elem = TREE_VEC_ELT (elems, i);
 197       TREE_VEC_ELT (folded_elems, i) =
 198         (elem && !TYPE_P (elem)) ? cplus_expand_constant (elem) : elem;
 199
 200     }
 201   return folded_elems;
 202 }
 203
 204 /* The C++ implementation of the LANG_HOOKS_GET_INNERMOST_GENERIC_ARGS
 205    hook. It returns the innermost template arguments of type T, and
 206    makes sure those arguments are folded enough for the debug info
 207    emitter.  */
 208
 209 static tree
 210 get_template_innermost_arguments_folded (const_tree t)
 211 {
 212   return fold_cplus_constants (get_template_innermost_arguments (t));
 213 }
 214
 215 static tree
 216 get_template_argument_pack_elems_folded (const_tree t)
 217 {
 218   return fold_cplus_constants (get_template_argument_pack_elems (t));
 219 }
 220
 221 /* The C++ version of the enum_underlying_base_type langhook.
 222    See also cp/semantics.c (finish_underlying_type).  */
 223
 224 static
 225 tree cxx_enum_underlying_base_type (const_tree type)
 226 {
 227   tree underlying_type = ENUM_UNDERLYING_TYPE (type);
 228
 229   if (! ENUM_FIXED_UNDERLYING_TYPE_P (type))
 230     underlying_type
 231       = c_common_type_for_mode (TYPE_MODE (underlying_type),
 232                                 TYPE_UNSIGNED (underlying_type));
 233
 234   return underlying_type;
 235 }
 236
 237 #if CHECKING_P
 238
 239 namespace selftest {
 240
 241 /* Implementation of LANG_HOOKS_RUN_LANG_SELFTESTS for the C++ frontend.  */
 242
 243 void
 244 run_cp_tests (void)
 245 {
 246   /* Run selftests shared within the C family.  */
 247   c_family_tests ();
 248
 249   /* Additional C++-specific tests.  */
 250   cp_pt_c_tests ();
 251   cp_tree_c_tests ();
 252 }
 253
 254 } // namespace selftest
 255
 256 #endif /* #if CHECKING_P */
 257
 258
 259 #include "gt-cp-cp-lang.h"
 260 #include "gtype-cp.h"