gcc/cp/cp-lang.c

   1 /* Language-dependent hooks for C++.
   2    Copyright (C) 2001-2020 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 const char * cxx_dwarf_name (tree t, int verbosity);
  32 static enum classify_record cp_classify_record (tree type);
  33 static tree cp_eh_personality (void);
  34 static tree get_template_innermost_arguments_folded (const_tree);
  35 static tree get_template_argument_pack_elems_folded (const_tree);
  36 static tree cxx_enum_underlying_base_type (const_tree);
  37
  38 /* Lang hooks common to C++ and ObjC++ are declared in cp/cp-objcp-common.h;
  39    consequently, there should be very few hooks below.  */
  40
  41 #undef LANG_HOOKS_NAME
  42 #define LANG_HOOKS_NAME "GNU C++"
  43 #undef LANG_HOOKS_INIT
  44 #define LANG_HOOKS_INIT cxx_init
  45 #undef LANG_HOOKS_CLASSIFY_RECORD
  46 #define LANG_HOOKS_CLASSIFY_RECORD cp_classify_record
  47 #undef LANG_HOOKS_GENERIC_TYPE_P
  48 #define LANG_HOOKS_GENERIC_TYPE_P class_tmpl_impl_spec_p
  49
  50 #undef LANG_HOOKS_GET_INNERMOST_GENERIC_PARMS
  51 #define LANG_HOOKS_GET_INNERMOST_GENERIC_PARMS \
  52         get_primary_template_innermost_parameters
  53 #undef LANG_HOOKS_GET_INNERMOST_GENERIC_ARGS
  54 #define LANG_HOOKS_GET_INNERMOST_GENERIC_ARGS \
  55         get_template_innermost_arguments_folded
  56 #undef LANG_HOOKS_FUNCTION_PARAMETER_PACK_P
  57 #define LANG_HOOKS_FUNCTION_PARAMETER_PACK_P \
  58         function_parameter_pack_p
  59 #undef LANG_HOOKS_GET_ARGUMENT_PACK_ELEMS
  60 #define LANG_HOOKS_GET_ARGUMENT_PACK_ELEMS \
  61         get_template_argument_pack_elems_folded
  62 #undef LANG_HOOKS_GENERIC_GENERIC_PARAMETER_DECL_P
  63 #define LANG_HOOKS_GENERIC_GENERIC_PARAMETER_DECL_P \
  64         template_template_parameter_p
  65 #undef LANG_HOOKS_FUNCTION_PARM_EXPANDED_FROM_PACK_P
  66 #define LANG_HOOKS_FUNCTION_PARM_EXPANDED_FROM_PACK_P \
  67         function_parameter_expanded_from_pack_p
  68 #undef LANG_HOOKS_GET_GENERIC_FUNCTION_DECL
  69 #define LANG_HOOKS_GET_GENERIC_FUNCTION_DECL get_function_template_decl
  70 #undef LANG_HOOKS_DWARF_NAME
  71 #define LANG_HOOKS_DWARF_NAME cxx_dwarf_name
  72 #undef LANG_HOOKS_INIT_TS
  73 #define LANG_HOOKS_INIT_TS cp_common_init_ts
  74 #undef LANG_HOOKS_EH_PERSONALITY
  75 #define LANG_HOOKS_EH_PERSONALITY cp_eh_personality
  76 #undef LANG_HOOKS_EH_RUNTIME_TYPE
  77 #define LANG_HOOKS_EH_RUNTIME_TYPE build_eh_type_type
  78 #undef LANG_HOOKS_ENUM_UNDERLYING_BASE_TYPE
  79 #define LANG_HOOKS_ENUM_UNDERLYING_BASE_TYPE cxx_enum_underlying_base_type
  80
  81 #if CHECKING_P
  82 #undef LANG_HOOKS_RUN_LANG_SELFTESTS
  83 #define LANG_HOOKS_RUN_LANG_SELFTESTS selftest::run_cp_tests
  84 #endif /* #if CHECKING_P */
  85
  86 #undef LANG_HOOKS_GET_SUBSTRING_LOCATION
  87 #define LANG_HOOKS_GET_SUBSTRING_LOCATION c_get_substring_location
  88
  89 /* Each front end provides its own lang hook initializer.  */
  90 struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
  91
  92 /* Lang hook routines common to C++ and ObjC++ appear in cp/cp-objcp-common.c;
  93    there should be very few routines below.  */
  94
  95 /* The following function does something real, but only in Objective-C++.  */
  96
  97 tree
  98 objcp_tsubst_copy_and_build (tree /*t*/,
  99                              tree /*args*/,
 100                              tsubst_flags_t /*complain*/,
 101                              tree /*in_decl*/,
 102                              bool /*function_p*/)
 103 {
 104   return NULL_TREE;
 105 }
 106
 107 static const char *
 108 cxx_dwarf_name (tree t, int verbosity)
 109 {
 110   gcc_assert (DECL_P (t));
 111
 112   if (DECL_NAME (t) && IDENTIFIER_ANON_P (DECL_NAME (t)))
 113     return NULL;
 114   if (verbosity >= 2)
 115     return decl_as_dwarf_string (t,
 116                                  TFF_DECL_SPECIFIERS | TFF_UNQUALIFIED_NAME
 117                                  | TFF_NO_OMIT_DEFAULT_TEMPLATE_ARGUMENTS);
 118
 119   return lang_decl_dwarf_name (t, verbosity, false);
 120 }
 121
 122 static enum classify_record
 123 cp_classify_record (tree type)
 124 {
 125   if (TYPE_LANG_SPECIFIC (type)
 126       && CLASSTYPE_DECLARED_CLASS (type))
 127     return RECORD_IS_CLASS;
 128
 129   return RECORD_IS_STRUCT;
 130 }
 131
 132 static GTY(()) tree cp_eh_personality_decl;
 133
 134 static tree
 135 cp_eh_personality (void)
 136 {
 137   if (!cp_eh_personality_decl)
 138     cp_eh_personality_decl = build_personality_function ("gxx");
 139
 140   return cp_eh_personality_decl;
 141 }
 142
 143 /* This is a subroutine of fold_cplus_constants.  It returns TRUE if T
 144    is a C++ specific constant that needs to be folded further before
 145    being passed to the debug info emitter.  */
 146
 147 static bool
 148 template_arg_needs_folding (const_tree t)
 149 {
 150   /* For now only PTRMEM_CST nodes are to be folded further.  */
 151   if (TREE_CODE (t) == PTRMEM_CST)
 152     return true;
 153   return false;
 154 }
 155
 156 /* Fold the elements of the TREE_VEC C which are C++ specific nodes
 157    that would need folding so that they can be processed by the debug
 158    info emitter. This is a subroutine of
 159    get_template_innermost_arguments_folded and
 160    get_template_argument_pack_elems_folded.  */
 161
 162 static tree
 163 fold_cplus_constants (const_tree c)
 164 {
 165   tree folded_elems, elems = CONST_CAST_TREE (c);
 166   int vec_len, i;
 167
 168   if (elems == NULL_TREE || elems == error_mark_node)
 169     return elems;
 170
 171   vec_len = TREE_VEC_LENGTH (elems);
 172
 173   /* First check if there is at least one element that needs
 174      folding. If there is none, we just return ELEMS. Otherwise create
 175      and return a new tree vector that contains the folded versions of
 176      ELEMS. This is to avoid allocating memory if we don't need
 177      to.  */
 178   for (i = 0; i < vec_len; ++i)
 179     {
 180       if (template_arg_needs_folding (TREE_VEC_ELT (elems, i)))
 181         break;
 182     }
 183   if (i == vec_len)
 184     return elems;
 185
 186   folded_elems = make_tree_vec (vec_len);
 187   for (i = 0; i < vec_len; ++i)
 188     {
 189       tree elem = TREE_VEC_ELT (elems, i);
 190       TREE_VEC_ELT (folded_elems, i) =
 191         (elem && !TYPE_P (elem)) ? cplus_expand_constant (elem) : elem;
 192
 193     }
 194   return folded_elems;
 195 }
 196
 197 /* The C++ implementation of the LANG_HOOKS_GET_INNERMOST_GENERIC_ARGS
 198    hook. It returns the innermost template arguments of type T, and
 199    makes sure those arguments are folded enough for the debug info
 200    emitter.  */
 201
 202 static tree
 203 get_template_innermost_arguments_folded (const_tree t)
 204 {
 205   return fold_cplus_constants (get_template_innermost_arguments (t));
 206 }
 207
 208 static tree
 209 get_template_argument_pack_elems_folded (const_tree t)
 210 {
 211   return fold_cplus_constants (get_template_argument_pack_elems (t));
 212 }
 213
 214 /* The C++ version of the enum_underlying_base_type langhook.
 215    See also cp/semantics.c (finish_underlying_type).  */
 216
 217 static
 218 tree cxx_enum_underlying_base_type (const_tree type)
 219 {
 220   tree underlying_type = ENUM_UNDERLYING_TYPE (type);
 221
 222   if (! ENUM_FIXED_UNDERLYING_TYPE_P (type))
 223     underlying_type
 224       = c_common_type_for_mode (TYPE_MODE (underlying_type),
 225                                 TYPE_UNSIGNED (underlying_type));
 226
 227   return underlying_type;
 228 }
 229
 230 #if CHECKING_P
 231
 232 namespace selftest {
 233
 234 /* Implementation of LANG_HOOKS_RUN_LANG_SELFTESTS for the C++ frontend.  */
 235
 236 void
 237 run_cp_tests (void)
 238 {
 239   /* Run selftests shared within the C family.  */
 240   c_family_tests ();
 241
 242   /* Additional C++-specific tests.  */
 243   cp_pt_c_tests ();
 244   cp_tree_c_tests ();
 245 }
 246
 247 } // namespace selftest
 248
 249 #endif /* #if CHECKING_P */
 250
 251
 252 #include "gt-cp-cp-lang.h"
 253 #include "gtype-cp.h"