gcc/cp/cp-lang.cc

   1 /* Language-dependent hooks for C++.
   2    Copyright (C) 2001-2024 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 #define INCLUDE_MEMORY
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "cp-tree.h"
  26 #include "stor-layout.h"
  27 #include "langhooks.h"
  28 #include "langhooks-def.h"
  29 #include "cp-objcp-common.h"
  30
  31 enum c_language_kind c_language = clk_cxx;
  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 static tree *cxx_omp_get_decl_init (tree);
  39 static void cxx_omp_finish_decl_inits (void);
  40 static const char *cp_get_sarif_source_language (const char *);
  41
  42 /* Lang hooks common to C++ and ObjC++ are declared in cp/cp-objcp-common.h;
  43    consequently, there should be very few hooks below.  */
  44
  45 #undef LANG_HOOKS_NAME
  46 #define LANG_HOOKS_NAME "GNU C++"
  47 #undef LANG_HOOKS_INIT
  48 #define LANG_HOOKS_INIT cxx_init
  49 #undef LANG_HOOKS_CLASSIFY_RECORD
  50 #define LANG_HOOKS_CLASSIFY_RECORD cp_classify_record
  51 #undef LANG_HOOKS_GENERIC_TYPE_P
  52 #define LANG_HOOKS_GENERIC_TYPE_P class_tmpl_impl_spec_p
  53
  54 #undef LANG_HOOKS_GET_INNERMOST_GENERIC_PARMS
  55 #define LANG_HOOKS_GET_INNERMOST_GENERIC_PARMS \
  56         get_primary_template_innermost_parameters
  57 #undef LANG_HOOKS_GET_INNERMOST_GENERIC_ARGS
  58 #define LANG_HOOKS_GET_INNERMOST_GENERIC_ARGS \
  59         get_template_innermost_arguments_folded
  60 #undef LANG_HOOKS_FUNCTION_PARAMETER_PACK_P
  61 #define LANG_HOOKS_FUNCTION_PARAMETER_PACK_P \
  62         function_parameter_pack_p
  63 #undef LANG_HOOKS_GET_ARGUMENT_PACK_ELEMS
  64 #define LANG_HOOKS_GET_ARGUMENT_PACK_ELEMS \
  65         get_template_argument_pack_elems_folded
  66 #undef LANG_HOOKS_GENERIC_GENERIC_PARAMETER_DECL_P
  67 #define LANG_HOOKS_GENERIC_GENERIC_PARAMETER_DECL_P \
  68         template_template_parameter_p
  69 #undef LANG_HOOKS_FUNCTION_PARM_EXPANDED_FROM_PACK_P
  70 #define LANG_HOOKS_FUNCTION_PARM_EXPANDED_FROM_PACK_P \
  71         function_parameter_expanded_from_pack_p
  72 #undef LANG_HOOKS_GET_GENERIC_FUNCTION_DECL
  73 #define LANG_HOOKS_GET_GENERIC_FUNCTION_DECL get_function_template_decl
  74 #undef LANG_HOOKS_DWARF_NAME
  75 #define LANG_HOOKS_DWARF_NAME cxx_dwarf_name
  76 #undef LANG_HOOKS_INIT_TS
  77 #define LANG_HOOKS_INIT_TS cp_common_init_ts
  78 #undef LANG_HOOKS_EH_PERSONALITY
  79 #define LANG_HOOKS_EH_PERSONALITY cp_eh_personality
  80 #undef LANG_HOOKS_EH_RUNTIME_TYPE
  81 #define LANG_HOOKS_EH_RUNTIME_TYPE build_eh_type_type
  82 #undef LANG_HOOKS_ENUM_UNDERLYING_BASE_TYPE
  83 #define LANG_HOOKS_ENUM_UNDERLYING_BASE_TYPE cxx_enum_underlying_base_type
  84 #undef LANG_HOOKS_PREPROCESS_MAIN_FILE
  85 #define LANG_HOOKS_PREPROCESS_MAIN_FILE module_begin_main_file
  86 #undef LANG_HOOKS_PREPROCESS_OPTIONS
  87 #define LANG_HOOKS_PREPROCESS_OPTIONS module_preprocess_options
  88 #undef LANG_HOOKS_PREPROCESS_TOKEN
  89 #define LANG_HOOKS_PREPROCESS_TOKEN module_token_pre
  90
  91 #if CHECKING_P
  92 #undef LANG_HOOKS_RUN_LANG_SELFTESTS
  93 #define LANG_HOOKS_RUN_LANG_SELFTESTS selftest::run_cp_tests
  94 #endif /* #if CHECKING_P */
  95
  96 #undef LANG_HOOKS_GET_SUBSTRING_LOCATION
  97 #define LANG_HOOKS_GET_SUBSTRING_LOCATION c_get_substring_location
  98
  99 #undef LANG_HOOKS_OMP_GET_DECL_INIT
 100 #define LANG_HOOKS_OMP_GET_DECL_INIT cxx_omp_get_decl_init
 101
 102 #undef LANG_HOOKS_OMP_FINISH_DECL_INITS
 103 #define LANG_HOOKS_OMP_FINISH_DECL_INITS cxx_omp_finish_decl_inits
 104
 105 #undef LANG_HOOKS_GET_SARIF_SOURCE_LANGUAGE
 106 #define LANG_HOOKS_GET_SARIF_SOURCE_LANGUAGE cp_get_sarif_source_language
 107
 108 /* Each front end provides its own lang hook initializer.  */
 109 struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
 110
 111 /* Lang hook routines common to C++ and ObjC++ appear in cp/cp-objcp-common.cc;
 112    there should be very few routines below.  */
 113
 114 /* The following function does something real, but only in Objective-C++.  */
 115
 116 tree
 117 objcp_tsubst_expr (tree /*t*/, tree /*args*/, tsubst_flags_t /*complain*/,
 118                    tree /*in_decl*/)
 119 {
 120   return NULL_TREE;
 121 }
 122
 123 /* Implement c-family hook to add language-specific features
 124    for __has_{feature,extension}.  */
 125
 126 void
 127 c_family_register_lang_features ()
 128 {
 129   cp_register_features ();
 130 }
 131
 132 static const char *
 133 cxx_dwarf_name (tree t, int verbosity)
 134 {
 135   gcc_assert (DECL_P (t));
 136
 137   if (DECL_NAME (t) && IDENTIFIER_ANON_P (DECL_NAME (t)))
 138     return NULL;
 139   if (verbosity >= 2)
 140     return decl_as_dwarf_string (t,
 141                                  TFF_DECL_SPECIFIERS | TFF_UNQUALIFIED_NAME
 142                                  | TFF_NO_OMIT_DEFAULT_TEMPLATE_ARGUMENTS);
 143
 144   return lang_decl_dwarf_name (t, verbosity, false);
 145 }
 146
 147 static enum classify_record
 148 cp_classify_record (tree type)
 149 {
 150   if (TYPE_LANG_SPECIFIC (type)
 151       && CLASSTYPE_DECLARED_CLASS (type))
 152     return RECORD_IS_CLASS;
 153
 154   return RECORD_IS_STRUCT;
 155 }
 156
 157 static GTY(()) tree cp_eh_personality_decl;
 158
 159 static tree
 160 cp_eh_personality (void)
 161 {
 162   if (!cp_eh_personality_decl)
 163     cp_eh_personality_decl = build_personality_function ("gxx");
 164
 165   return cp_eh_personality_decl;
 166 }
 167
 168 /* This is a subroutine of fold_cplus_constants.  It returns TRUE if T
 169    is a C++ specific constant that needs to be folded further before
 170    being passed to the debug info emitter.  */
 171
 172 static bool
 173 template_arg_needs_folding (const_tree t)
 174 {
 175   /* For now only PTRMEM_CST nodes are to be folded further.  */
 176   if (TREE_CODE (t) == PTRMEM_CST)
 177     return true;
 178   return false;
 179 }
 180
 181 /* Fold the elements of the TREE_VEC C which are C++ specific nodes
 182    that would need folding so that they can be processed by the debug
 183    info emitter. This is a subroutine of
 184    get_template_innermost_arguments_folded and
 185    get_template_argument_pack_elems_folded.  */
 186
 187 static tree
 188 fold_cplus_constants (const_tree c)
 189 {
 190   tree folded_elems, elems = CONST_CAST_TREE (c);
 191   int vec_len, i;
 192
 193   if (elems == NULL_TREE || elems == error_mark_node)
 194     return elems;
 195
 196   vec_len = TREE_VEC_LENGTH (elems);
 197
 198   /* First check if there is at least one element that needs
 199      folding. If there is none, we just return ELEMS. Otherwise create
 200      and return a new tree vector that contains the folded versions of
 201      ELEMS. This is to avoid allocating memory if we don't need
 202      to.  */
 203   for (i = 0; i < vec_len; ++i)
 204     {
 205       if (template_arg_needs_folding (TREE_VEC_ELT (elems, i)))
 206         break;
 207     }
 208   if (i == vec_len)
 209     return elems;
 210
 211   folded_elems = make_tree_vec (vec_len);
 212   for (i = 0; i < vec_len; ++i)
 213     {
 214       tree elem = TREE_VEC_ELT (elems, i);
 215       TREE_VEC_ELT (folded_elems, i) =
 216         (elem && !TYPE_P (elem)) ? cplus_expand_constant (elem) : elem;
 217
 218     }
 219   return folded_elems;
 220 }
 221
 222 /* The C++ implementation of the LANG_HOOKS_GET_INNERMOST_GENERIC_ARGS
 223    hook. It returns the innermost template arguments of type T, and
 224    makes sure those arguments are folded enough for the debug info
 225    emitter.  */
 226
 227 static tree
 228 get_template_innermost_arguments_folded (const_tree t)
 229 {
 230   return fold_cplus_constants (get_template_innermost_arguments (t));
 231 }
 232
 233 static tree
 234 get_template_argument_pack_elems_folded (const_tree t)
 235 {
 236   return fold_cplus_constants (get_template_argument_pack_elems (t));
 237 }
 238
 239 /* The C++ version of the enum_underlying_base_type langhook.
 240    See also cp/semantics.cc (finish_underlying_type).  */
 241
 242 static
 243 tree cxx_enum_underlying_base_type (const_tree type)
 244 {
 245   tree underlying_type = ENUM_UNDERLYING_TYPE (type);
 246
 247   if (! ENUM_FIXED_UNDERLYING_TYPE_P (type))
 248     underlying_type
 249       = c_common_type_for_mode (TYPE_MODE (underlying_type),
 250                                 TYPE_UNSIGNED (underlying_type));
 251
 252   return underlying_type;
 253 }
 254
 255 /* The C++ version of the omp_get_decl_init langhook returns the static
 256    initializer for a variable declaration if present, otherwise it
 257    tries to find and return the dynamic initializer.  If not present,
 258    it returns NULL.  */
 259
 260 static tree *
 261 cxx_omp_get_decl_init (tree decl)
 262 {
 263   if (DECL_INITIAL (decl))
 264     return &DECL_INITIAL (decl);
 265
 266   return hash_map_safe_get (dynamic_initializers, decl);
 267 }
 268
 269 /* The C++ version of the omp_finish_decl_inits langhook allows GC to
 270    reclaim the memory used by the hash-map used to hold dynamic initializer
 271    information.  */
 272
 273 static void
 274 cxx_omp_finish_decl_inits (void)
 275 {
 276   dynamic_initializers = NULL;
 277 }
 278
 279 /* Get a value for the SARIF v2.1.0 "artifact.sourceLanguage" property,
 280    based on the list in SARIF v2.1.0 Appendix J.  */
 281
 282 static const char *
 283 cp_get_sarif_source_language (const char *)
 284 {
 285   return "cplusplus";
 286 }
 287
 288 #if CHECKING_P
 289
 290 namespace selftest {
 291
 292 /* Implementation of LANG_HOOKS_RUN_LANG_SELFTESTS for the C++ frontend.  */
 293
 294 void
 295 run_cp_tests (void)
 296 {
 297   /* Run selftests shared within the C family.  */
 298   c_family_tests ();
 299
 300   /* Additional C++-specific tests.  */
 301   cp_pt_cc_tests ();
 302   cp_tree_cc_tests ();
 303 }
 304
 305 } // namespace selftest
 306
 307 #endif /* #if CHECKING_P */
 308
 309
 310 #include "gt-cp-cp-lang.h"
 311 #include "gtype-cp.h"