gcc/cp/cp-lang.c

   1 /* Language-dependent hooks for C++.
   2    Copyright (C) 2001-2021 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 static tree *cxx_omp_get_decl_init (tree);
  38 static void cxx_omp_finish_decl_inits (void);
  39
  40 /* Lang hooks common to C++ and ObjC++ are declared in cp/cp-objcp-common.h;
  41    consequently, there should be very few hooks below.  */
  42
  43 #undef LANG_HOOKS_NAME
  44 #define LANG_HOOKS_NAME "GNU C++"
  45 #undef LANG_HOOKS_INIT
  46 #define LANG_HOOKS_INIT cxx_init
  47 #undef LANG_HOOKS_CLASSIFY_RECORD
  48 #define LANG_HOOKS_CLASSIFY_RECORD cp_classify_record
  49 #undef LANG_HOOKS_GENERIC_TYPE_P
  50 #define LANG_HOOKS_GENERIC_TYPE_P class_tmpl_impl_spec_p
  51
  52 #undef LANG_HOOKS_GET_INNERMOST_GENERIC_PARMS
  53 #define LANG_HOOKS_GET_INNERMOST_GENERIC_PARMS \
  54         get_primary_template_innermost_parameters
  55 #undef LANG_HOOKS_GET_INNERMOST_GENERIC_ARGS
  56 #define LANG_HOOKS_GET_INNERMOST_GENERIC_ARGS \
  57         get_template_innermost_arguments_folded
  58 #undef LANG_HOOKS_FUNCTION_PARAMETER_PACK_P
  59 #define LANG_HOOKS_FUNCTION_PARAMETER_PACK_P \
  60         function_parameter_pack_p
  61 #undef LANG_HOOKS_GET_ARGUMENT_PACK_ELEMS
  62 #define LANG_HOOKS_GET_ARGUMENT_PACK_ELEMS \
  63         get_template_argument_pack_elems_folded
  64 #undef LANG_HOOKS_GENERIC_GENERIC_PARAMETER_DECL_P
  65 #define LANG_HOOKS_GENERIC_GENERIC_PARAMETER_DECL_P \
  66         template_template_parameter_p
  67 #undef LANG_HOOKS_FUNCTION_PARM_EXPANDED_FROM_PACK_P
  68 #define LANG_HOOKS_FUNCTION_PARM_EXPANDED_FROM_PACK_P \
  69         function_parameter_expanded_from_pack_p
  70 #undef LANG_HOOKS_GET_GENERIC_FUNCTION_DECL
  71 #define LANG_HOOKS_GET_GENERIC_FUNCTION_DECL get_function_template_decl
  72 #undef LANG_HOOKS_DWARF_NAME
  73 #define LANG_HOOKS_DWARF_NAME cxx_dwarf_name
  74 #undef LANG_HOOKS_INIT_TS
  75 #define LANG_HOOKS_INIT_TS cp_common_init_ts
  76 #undef LANG_HOOKS_EH_PERSONALITY
  77 #define LANG_HOOKS_EH_PERSONALITY cp_eh_personality
  78 #undef LANG_HOOKS_EH_RUNTIME_TYPE
  79 #define LANG_HOOKS_EH_RUNTIME_TYPE build_eh_type_type
  80 #undef LANG_HOOKS_ENUM_UNDERLYING_BASE_TYPE
  81 #define LANG_HOOKS_ENUM_UNDERLYING_BASE_TYPE cxx_enum_underlying_base_type
  82 #undef LANG_HOOKS_PREPROCESS_MAIN_FILE
  83 #define LANG_HOOKS_PREPROCESS_MAIN_FILE module_begin_main_file
  84 #undef LANG_HOOKS_PREPROCESS_OPTIONS
  85 #define LANG_HOOKS_PREPROCESS_OPTIONS module_preprocess_options
  86 #undef LANG_HOOKS_PREPROCESS_TOKEN
  87 #define LANG_HOOKS_PREPROCESS_TOKEN module_token_pre
  88
  89 #if CHECKING_P
  90 #undef LANG_HOOKS_RUN_LANG_SELFTESTS
  91 #define LANG_HOOKS_RUN_LANG_SELFTESTS selftest::run_cp_tests
  92 #endif /* #if CHECKING_P */
  93
  94 #undef LANG_HOOKS_GET_SUBSTRING_LOCATION
  95 #define LANG_HOOKS_GET_SUBSTRING_LOCATION c_get_substring_location
  96
  97 #undef LANG_HOOKS_OMP_GET_DECL_INIT
  98 #define LANG_HOOKS_OMP_GET_DECL_INIT cxx_omp_get_decl_init
  99
 100 #undef LANG_HOOKS_OMP_FINISH_DECL_INITS
 101 #define LANG_HOOKS_OMP_FINISH_DECL_INITS cxx_omp_finish_decl_inits
 102
 103 /* Each front end provides its own lang hook initializer.  */
 104 struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
 105
 106 /* Lang hook routines common to C++ and ObjC++ appear in cp/cp-objcp-common.c;
 107    there should be very few routines below.  */
 108
 109 /* The following function does something real, but only in Objective-C++.  */
 110
 111 tree
 112 objcp_tsubst_copy_and_build (tree /*t*/,
 113                              tree /*args*/,
 114                              tsubst_flags_t /*complain*/,
 115                              tree /*in_decl*/,
 116                              bool /*function_p*/)
 117 {
 118   return NULL_TREE;
 119 }
 120
 121 static const char *
 122 cxx_dwarf_name (tree t, int verbosity)
 123 {
 124   gcc_assert (DECL_P (t));
 125
 126   if (DECL_NAME (t) && IDENTIFIER_ANON_P (DECL_NAME (t)))
 127     return NULL;
 128   if (verbosity >= 2)
 129     return decl_as_dwarf_string (t,
 130                                  TFF_DECL_SPECIFIERS | TFF_UNQUALIFIED_NAME
 131                                  | TFF_NO_OMIT_DEFAULT_TEMPLATE_ARGUMENTS);
 132
 133   return lang_decl_dwarf_name (t, verbosity, false);
 134 }
 135
 136 static enum classify_record
 137 cp_classify_record (tree type)
 138 {
 139   if (TYPE_LANG_SPECIFIC (type)
 140       && CLASSTYPE_DECLARED_CLASS (type))
 141     return RECORD_IS_CLASS;
 142
 143   return RECORD_IS_STRUCT;
 144 }
 145
 146 static GTY(()) tree cp_eh_personality_decl;
 147
 148 static tree
 149 cp_eh_personality (void)
 150 {
 151   if (!cp_eh_personality_decl)
 152     cp_eh_personality_decl = build_personality_function ("gxx");
 153
 154   return cp_eh_personality_decl;
 155 }
 156
 157 /* This is a subroutine of fold_cplus_constants.  It returns TRUE if T
 158    is a C++ specific constant that needs to be folded further before
 159    being passed to the debug info emitter.  */
 160
 161 static bool
 162 template_arg_needs_folding (const_tree t)
 163 {
 164   /* For now only PTRMEM_CST nodes are to be folded further.  */
 165   if (TREE_CODE (t) == PTRMEM_CST)
 166     return true;
 167   return false;
 168 }
 169
 170 /* Fold the elements of the TREE_VEC C which are C++ specific nodes
 171    that would need folding so that they can be processed by the debug
 172    info emitter. This is a subroutine of
 173    get_template_innermost_arguments_folded and
 174    get_template_argument_pack_elems_folded.  */
 175
 176 static tree
 177 fold_cplus_constants (const_tree c)
 178 {
 179   tree folded_elems, elems = CONST_CAST_TREE (c);
 180   int vec_len, i;
 181
 182   if (elems == NULL_TREE || elems == error_mark_node)
 183     return elems;
 184
 185   vec_len = TREE_VEC_LENGTH (elems);
 186
 187   /* First check if there is at least one element that needs
 188      folding. If there is none, we just return ELEMS. Otherwise create
 189      and return a new tree vector that contains the folded versions of
 190      ELEMS. This is to avoid allocating memory if we don't need
 191      to.  */
 192   for (i = 0; i < vec_len; ++i)
 193     {
 194       if (template_arg_needs_folding (TREE_VEC_ELT (elems, i)))
 195         break;
 196     }
 197   if (i == vec_len)
 198     return elems;
 199
 200   folded_elems = make_tree_vec (vec_len);
 201   for (i = 0; i < vec_len; ++i)
 202     {
 203       tree elem = TREE_VEC_ELT (elems, i);
 204       TREE_VEC_ELT (folded_elems, i) =
 205         (elem && !TYPE_P (elem)) ? cplus_expand_constant (elem) : elem;
 206
 207     }
 208   return folded_elems;
 209 }
 210
 211 /* The C++ implementation of the LANG_HOOKS_GET_INNERMOST_GENERIC_ARGS
 212    hook. It returns the innermost template arguments of type T, and
 213    makes sure those arguments are folded enough for the debug info
 214    emitter.  */
 215
 216 static tree
 217 get_template_innermost_arguments_folded (const_tree t)
 218 {
 219   return fold_cplus_constants (get_template_innermost_arguments (t));
 220 }
 221
 222 static tree
 223 get_template_argument_pack_elems_folded (const_tree t)
 224 {
 225   return fold_cplus_constants (get_template_argument_pack_elems (t));
 226 }
 227
 228 /* The C++ version of the enum_underlying_base_type langhook.
 229    See also cp/semantics.c (finish_underlying_type).  */
 230
 231 static
 232 tree cxx_enum_underlying_base_type (const_tree type)
 233 {
 234   tree underlying_type = ENUM_UNDERLYING_TYPE (type);
 235
 236   if (! ENUM_FIXED_UNDERLYING_TYPE_P (type))
 237     underlying_type
 238       = c_common_type_for_mode (TYPE_MODE (underlying_type),
 239                                 TYPE_UNSIGNED (underlying_type));
 240
 241   return underlying_type;
 242 }
 243
 244 /* The C++ version of the omp_get_decl_init langhook returns the static
 245    initializer for a variable declaration if present, otherwise it
 246    tries to find and return the dynamic initializer.  If not present,
 247    it returns NULL.  */
 248
 249 static tree *
 250 cxx_omp_get_decl_init (tree decl)
 251 {
 252   if (DECL_INITIAL (decl))
 253     return &DECL_INITIAL (decl);
 254
 255   return hash_map_safe_get (dynamic_initializers, decl);
 256 }
 257
 258 /* The C++ version of the omp_finish_decl_inits langhook allows GC to
 259    reclaim the memory used by the hash-map used to hold dynamic initializer
 260    information.  */
 261
 262 static void
 263 cxx_omp_finish_decl_inits (void)
 264 {
 265   dynamic_initializers = NULL;
 266 }
 267
 268 #if CHECKING_P
 269
 270 namespace selftest {
 271
 272 /* Implementation of LANG_HOOKS_RUN_LANG_SELFTESTS for the C++ frontend.  */
 273
 274 void
 275 run_cp_tests (void)
 276 {
 277   /* Run selftests shared within the C family.  */
 278   c_family_tests ();
 279
 280   /* Additional C++-specific tests.  */
 281   cp_pt_c_tests ();
 282   cp_tree_c_tests ();
 283 }
 284
 285 } // namespace selftest
 286
 287 #endif /* #if CHECKING_P */
 288
 289
 290 #include "gt-cp-cp-lang.h"
 291 #include "gtype-cp.h"