1/* Language-dependent hooks for C++.
2   Copyright (C) 2001-2022 Free Software Foundation, Inc.
3   Contributed by Alexandre Oliva  <aoliva@redhat.com>
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify
8it under the terms of the GNU General Public License as published by
9the Free Software Foundation; either version 3, or (at your option)
10any later version.
11
12GCC is distributed in the hope that it will be useful,
13but WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15GNU General Public License for more details.
16
17You should have received a copy of the GNU General Public License
18along 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
30enum c_language_kind c_language = clk_cxx;
31static const char * cxx_dwarf_name (tree t, int verbosity);
32static enum classify_record cp_classify_record (tree type);
33static tree cp_eh_personality (void);
34static tree get_template_innermost_arguments_folded (const_tree);
35static tree get_template_argument_pack_elems_folded (const_tree);
36static tree cxx_enum_underlying_base_type (const_tree);
37static tree *cxx_omp_get_decl_init (tree);
38static 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.  */
104struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
105
106/* Lang hook routines common to C++ and ObjC++ appear in cp/cp-objcp-common.cc;
107   there should be very few routines below.  */
108
109/* The following function does something real, but only in Objective-C++.  */
110
111tree
112objcp_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
121static const char *
122cxx_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
136static enum classify_record
137cp_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
146static GTY(()) tree cp_eh_personality_decl;
147
148static tree
149cp_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
161static bool
162template_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
176static tree
177fold_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
216static tree
217get_template_innermost_arguments_folded (const_tree t)
218{
219  return fold_cplus_constants (get_template_innermost_arguments (t));
220}
221
222static tree
223get_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.cc (finish_underlying_type).  */
230
231static
232tree 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
249static tree *
250cxx_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
262static void
263cxx_omp_finish_decl_inits (void)
264{
265  dynamic_initializers = NULL;
266}
267
268#if CHECKING_P
269
270namespace selftest {
271
272/* Implementation of LANG_HOOKS_RUN_LANG_SELFTESTS for the C++ frontend.  */
273
274void
275run_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_cc_tests ();
282  cp_tree_cc_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"
292