gcc/cp/cp-lang.cc

   1 /* Language-dependent hooks for C++.
   2    Copyright (C) 2001-2023 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 static const char *cp_get_sarif_source_language (const char *);
  40
  41 /* Lang hooks common to C++ and ObjC++ are declared in cp/cp-objcp-common.h;
  42    consequently, there should be very few hooks below.  */
  43
  44 #undef LANG_HOOKS_NAME
  45 #define LANG_HOOKS_NAME "GNU C++"
  46 #undef LANG_HOOKS_INIT
  47 #define LANG_HOOKS_INIT cxx_init
  48 #undef LANG_HOOKS_CLASSIFY_RECORD
  49 #define LANG_HOOKS_CLASSIFY_RECORD cp_classify_record
  50 #undef LANG_HOOKS_GENERIC_TYPE_P
  51 #define LANG_HOOKS_GENERIC_TYPE_P class_tmpl_impl_spec_p
  52
  53 #undef LANG_HOOKS_GET_INNERMOST_GENERIC_PARMS
  54 #define LANG_HOOKS_GET_INNERMOST_GENERIC_PARMS \
  55         get_primary_template_innermost_parameters
  56 #undef LANG_HOOKS_GET_INNERMOST_GENERIC_ARGS
  57 #define LANG_HOOKS_GET_INNERMOST_GENERIC_ARGS \
  58         get_template_innermost_arguments_folded
  59 #undef LANG_HOOKS_FUNCTION_PARAMETER_PACK_P
  60 #define LANG_HOOKS_FUNCTION_PARAMETER_PACK_P \
  61         function_parameter_pack_p
  62 #undef LANG_HOOKS_GET_ARGUMENT_PACK_ELEMS
  63 #define LANG_HOOKS_GET_ARGUMENT_PACK_ELEMS \
  64         get_template_argument_pack_elems_folded
  65 #undef LANG_HOOKS_GENERIC_GENERIC_PARAMETER_DECL_P
  66 #define LANG_HOOKS_GENERIC_GENERIC_PARAMETER_DECL_P \
  67         template_template_parameter_p
  68 #undef LANG_HOOKS_FUNCTION_PARM_EXPANDED_FROM_PACK_P
  69 #define LANG_HOOKS_FUNCTION_PARM_EXPANDED_FROM_PACK_P \
  70         function_parameter_expanded_from_pack_p
  71 #undef LANG_HOOKS_GET_GENERIC_FUNCTION_DECL
  72 #define LANG_HOOKS_GET_GENERIC_FUNCTION_DECL get_function_template_decl
  73 #undef LANG_HOOKS_DWARF_NAME
  74 #define LANG_HOOKS_DWARF_NAME cxx_dwarf_name
  75 #undef LANG_HOOKS_INIT_TS
  76 #define LANG_HOOKS_INIT_TS cp_common_init_ts
  77 #undef LANG_HOOKS_EH_PERSONALITY
  78 #define LANG_HOOKS_EH_PERSONALITY cp_eh_personality
  79 #undef LANG_HOOKS_EH_RUNTIME_TYPE
  80 #define LANG_HOOKS_EH_RUNTIME_TYPE build_eh_type_type
  81 #undef LANG_HOOKS_ENUM_UNDERLYING_BASE_TYPE
  82 #define LANG_HOOKS_ENUM_UNDERLYING_BASE_TYPE cxx_enum_underlying_base_type
  83 #undef LANG_HOOKS_PREPROCESS_MAIN_FILE
  84 #define LANG_HOOKS_PREPROCESS_MAIN_FILE module_begin_main_file
  85 #undef LANG_HOOKS_PREPROCESS_OPTIONS
  86 #define LANG_HOOKS_PREPROCESS_OPTIONS module_preprocess_options
  87 #undef LANG_HOOKS_PREPROCESS_TOKEN
  88 #define LANG_HOOKS_PREPROCESS_TOKEN module_token_pre
  89
  90 #if CHECKING_P
  91 #undef LANG_HOOKS_RUN_LANG_SELFTESTS
  92 #define LANG_HOOKS_RUN_LANG_SELFTESTS selftest::run_cp_tests
  93 #endif /* #if CHECKING_P */
  94
  95 #undef LANG_HOOKS_GET_SUBSTRING_LOCATION
  96 #define LANG_HOOKS_GET_SUBSTRING_LOCATION c_get_substring_location
  97
  98 #undef LANG_HOOKS_OMP_GET_DECL_INIT
  99 #define LANG_HOOKS_OMP_GET_DECL_INIT cxx_omp_get_decl_init
 100
 101 #undef LANG_HOOKS_OMP_FINISH_DECL_INITS
 102 #define LANG_HOOKS_OMP_FINISH_DECL_INITS cxx_omp_finish_decl_inits
 103
 104 #undef LANG_HOOKS_GET_SARIF_SOURCE_LANGUAGE
 105 #define LANG_HOOKS_GET_SARIF_SOURCE_LANGUAGE cp_get_sarif_source_language
 106
 107 /* Each front end provides its own lang hook initializer.  */
 108 struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
 109
 110 /* Lang hook routines common to C++ and ObjC++ appear in cp/cp-objcp-common.cc;
 111    there should be very few routines below.  */
 112
 113 /* The following function does something real, but only in Objective-C++.  */
 114
 115 tree
 116 objcp_tsubst_copy_and_build (tree /*t*/,
 117                              tree /*args*/,
 118                              tsubst_flags_t /*complain*/,
 119                              tree /*in_decl*/)
 120 {
 121   return NULL_TREE;
 122 }
 123
 124 static const char *
 125 cxx_dwarf_name (tree t, int verbosity)
 126 {
 127   gcc_assert (DECL_P (t));
 128
 129   if (DECL_NAME (t) && IDENTIFIER_ANON_P (DECL_NAME (t)))
 130     return NULL;
 131   if (verbosity >= 2)
 132     return decl_as_dwarf_string (t,
 133                                  TFF_DECL_SPECIFIERS | TFF_UNQUALIFIED_NAME
 134                                  | TFF_NO_OMIT_DEFAULT_TEMPLATE_ARGUMENTS);
 135
 136   return lang_decl_dwarf_name (t, verbosity, false);
 137 }
 138
 139 static enum classify_record
 140 cp_classify_record (tree type)
 141 {
 142   if (TYPE_LANG_SPECIFIC (type)
 143       && CLASSTYPE_DECLARED_CLASS (type))
 144     return RECORD_IS_CLASS;
 145
 146   return RECORD_IS_STRUCT;
 147 }
 148
 149 static GTY(()) tree cp_eh_personality_decl;
 150
 151 static tree
 152 cp_eh_personality (void)
 153 {
 154   if (!cp_eh_personality_decl)
 155     cp_eh_personality_decl = build_personality_function ("gxx");
 156
 157   return cp_eh_personality_decl;
 158 }
 159
 160 /* This is a subroutine of fold_cplus_constants.  It returns TRUE if T
 161    is a C++ specific constant that needs to be folded further before
 162    being passed to the debug info emitter.  */
 163
 164 static bool
 165 template_arg_needs_folding (const_tree t)
 166 {
 167   /* For now only PTRMEM_CST nodes are to be folded further.  */
 168   if (TREE_CODE (t) == PTRMEM_CST)
 169     return true;
 170   return false;
 171 }
 172
 173 /* Fold the elements of the TREE_VEC C which are C++ specific nodes
 174    that would need folding so that they can be processed by the debug
 175    info emitter. This is a subroutine of
 176    get_template_innermost_arguments_folded and
 177    get_template_argument_pack_elems_folded.  */
 178
 179 static tree
 180 fold_cplus_constants (const_tree c)
 181 {
 182   tree folded_elems, elems = CONST_CAST_TREE (c);
 183   int vec_len, i;
 184
 185   if (elems == NULL_TREE || elems == error_mark_node)
 186     return elems;
 187
 188   vec_len = TREE_VEC_LENGTH (elems);
 189
 190   /* First check if there is at least one element that needs
 191      folding. If there is none, we just return ELEMS. Otherwise create
 192      and return a new tree vector that contains the folded versions of
 193      ELEMS. This is to avoid allocating memory if we don't need
 194      to.  */
 195   for (i = 0; i < vec_len; ++i)
 196     {
 197       if (template_arg_needs_folding (TREE_VEC_ELT (elems, i)))
 198         break;
 199     }
 200   if (i == vec_len)
 201     return elems;
 202
 203   folded_elems = make_tree_vec (vec_len);
 204   for (i = 0; i < vec_len; ++i)
 205     {
 206       tree elem = TREE_VEC_ELT (elems, i);
 207       TREE_VEC_ELT (folded_elems, i) =
 208         (elem && !TYPE_P (elem)) ? cplus_expand_constant (elem) : elem;
 209
 210     }
 211   return folded_elems;
 212 }
 213
 214 /* The C++ implementation of the LANG_HOOKS_GET_INNERMOST_GENERIC_ARGS
 215    hook. It returns the innermost template arguments of type T, and
 216    makes sure those arguments are folded enough for the debug info
 217    emitter.  */
 218
 219 static tree
 220 get_template_innermost_arguments_folded (const_tree t)
 221 {
 222   return fold_cplus_constants (get_template_innermost_arguments (t));
 223 }
 224
 225 static tree
 226 get_template_argument_pack_elems_folded (const_tree t)
 227 {
 228   return fold_cplus_constants (get_template_argument_pack_elems (t));
 229 }
 230
 231 /* The C++ version of the enum_underlying_base_type langhook.
 232    See also cp/semantics.cc (finish_underlying_type).  */
 233
 234 static
 235 tree cxx_enum_underlying_base_type (const_tree type)
 236 {
 237   tree underlying_type = ENUM_UNDERLYING_TYPE (type);
 238
 239   if (! ENUM_FIXED_UNDERLYING_TYPE_P (type))
 240     underlying_type
 241       = c_common_type_for_mode (TYPE_MODE (underlying_type),
 242                                 TYPE_UNSIGNED (underlying_type));
 243
 244   return underlying_type;
 245 }
 246
 247 /* The C++ version of the omp_get_decl_init langhook returns the static
 248    initializer for a variable declaration if present, otherwise it
 249    tries to find and return the dynamic initializer.  If not present,
 250    it returns NULL.  */
 251
 252 static tree *
 253 cxx_omp_get_decl_init (tree decl)
 254 {
 255   if (DECL_INITIAL (decl))
 256     return &DECL_INITIAL (decl);
 257
 258   return hash_map_safe_get (dynamic_initializers, decl);
 259 }
 260
 261 /* The C++ version of the omp_finish_decl_inits langhook allows GC to
 262    reclaim the memory used by the hash-map used to hold dynamic initializer
 263    information.  */
 264
 265 static void
 266 cxx_omp_finish_decl_inits (void)
 267 {
 268   dynamic_initializers = NULL;
 269 }
 270
 271 /* Get a value for the SARIF v2.1.0 "artifact.sourceLanguage" property,
 272    based on the list in SARIF v2.1.0 Appendix J.  */
 273
 274 static const char *
 275 cp_get_sarif_source_language (const char *)
 276 {
 277   return "cplusplus";
 278 }
 279
 280 #if CHECKING_P
 281
 282 namespace selftest {
 283
 284 /* Implementation of LANG_HOOKS_RUN_LANG_SELFTESTS for the C++ frontend.  */
 285
 286 void
 287 run_cp_tests (void)
 288 {
 289   /* Run selftests shared within the C family.  */
 290   c_family_tests ();
 291
 292   /* Additional C++-specific tests.  */
 293   cp_pt_cc_tests ();
 294   cp_tree_cc_tests ();
 295 }
 296
 297 } // namespace selftest
 298
 299 #endif /* #if CHECKING_P */
 300
 301
 302 #include "gt-cp-cp-lang.h"
 303 #include "gtype-cp.h"