xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/cp/cp-lang.c (revision 7330f729ccf0bd976a06f95fad452fe774fc7fd1)
1 /* Language-dependent hooks for C++.
2    Copyright (C) 2001-2017 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 void cp_init_ts (void);
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 
39 /* Lang hooks common to C++ and ObjC++ are declared in cp/cp-objcp-common.h;
40    consequently, there should be very few hooks below.  */
41 
42 #undef LANG_HOOKS_NAME
43 #define LANG_HOOKS_NAME "GNU C++"
44 #undef LANG_HOOKS_INIT
45 #define LANG_HOOKS_INIT cxx_init
46 #undef LANG_HOOKS_CLASSIFY_RECORD
47 #define LANG_HOOKS_CLASSIFY_RECORD cp_classify_record
48 #undef LANG_HOOKS_GENERIC_TYPE_P
49 #define LANG_HOOKS_GENERIC_TYPE_P class_tmpl_impl_spec_p
50 
51 #undef LANG_HOOKS_GET_INNERMOST_GENERIC_PARMS
52 #define LANG_HOOKS_GET_INNERMOST_GENERIC_PARMS \
53 	get_primary_template_innermost_parameters
54 #undef LANG_HOOKS_GET_INNERMOST_GENERIC_ARGS
55 #define LANG_HOOKS_GET_INNERMOST_GENERIC_ARGS \
56 	get_template_innermost_arguments_folded
57 #undef LANG_HOOKS_FUNCTION_PARAMETER_PACK_P
58 #define LANG_HOOKS_FUNCTION_PARAMETER_PACK_P \
59 	function_parameter_pack_p
60 #undef LANG_HOOKS_GET_ARGUMENT_PACK_ELEMS
61 #define LANG_HOOKS_GET_ARGUMENT_PACK_ELEMS \
62 	get_template_argument_pack_elems_folded
63 #undef LANG_HOOKS_GENERIC_GENERIC_PARAMETER_DECL_P
64 #define LANG_HOOKS_GENERIC_GENERIC_PARAMETER_DECL_P \
65 	template_template_parameter_p
66 #undef LANG_HOOKS_FUNCTION_PARM_EXPANDED_FROM_PACK_P
67 #define LANG_HOOKS_FUNCTION_PARM_EXPANDED_FROM_PACK_P \
68 	function_parameter_expanded_from_pack_p
69 #undef LANG_HOOKS_GET_GENERIC_FUNCTION_DECL
70 #define LANG_HOOKS_GET_GENERIC_FUNCTION_DECL get_function_template_decl
71 #undef LANG_HOOKS_DWARF_NAME
72 #define LANG_HOOKS_DWARF_NAME cxx_dwarf_name
73 #undef LANG_HOOKS_INIT_TS
74 #define LANG_HOOKS_INIT_TS cp_init_ts
75 #undef LANG_HOOKS_EH_PERSONALITY
76 #define LANG_HOOKS_EH_PERSONALITY cp_eh_personality
77 #undef LANG_HOOKS_EH_RUNTIME_TYPE
78 #define LANG_HOOKS_EH_RUNTIME_TYPE build_eh_type_type
79 #undef LANG_HOOKS_ENUM_UNDERLYING_BASE_TYPE
80 #define LANG_HOOKS_ENUM_UNDERLYING_BASE_TYPE cxx_enum_underlying_base_type
81 
82 /* Each front end provides its own lang hook initializer.  */
83 struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
84 
85 /* Lang hook routines common to C++ and ObjC++ appear in cp/cp-objcp-common.c;
86    there should be very few routines below.  */
87 
88 /* The following function does something real, but only in Objective-C++.  */
89 
90 tree
91 objcp_tsubst_copy_and_build (tree /*t*/,
92 			     tree /*args*/,
93 			     tsubst_flags_t /*complain*/,
94 			     tree /*in_decl*/,
95 			     bool /*function_p*/)
96 {
97   return NULL_TREE;
98 }
99 
100 static void
101 cp_init_ts (void)
102 {
103   cp_common_init_ts ();
104 
105   init_shadowed_var_for_decl ();
106 }
107 
108 static const char *
109 cxx_dwarf_name (tree t, int verbosity)
110 {
111   gcc_assert (DECL_P (t));
112 
113   if (DECL_NAME (t)
114       && (anon_aggrname_p (DECL_NAME (t)) || LAMBDA_TYPE_P (t)))
115     return NULL;
116   if (verbosity >= 2)
117     return decl_as_dwarf_string (t,
118                                  TFF_DECL_SPECIFIERS | TFF_UNQUALIFIED_NAME
119                                  | TFF_NO_OMIT_DEFAULT_TEMPLATE_ARGUMENTS);
120 
121   return lang_decl_dwarf_name (t, verbosity, false);
122 }
123 
124 static enum classify_record
125 cp_classify_record (tree type)
126 {
127   if (TYPE_LANG_SPECIFIC (type)
128       && CLASSTYPE_DECLARED_CLASS (type))
129     return RECORD_IS_CLASS;
130 
131   return RECORD_IS_STRUCT;
132 }
133 
134 static GTY(()) tree cp_eh_personality_decl;
135 
136 static tree
137 cp_eh_personality (void)
138 {
139   if (!cp_eh_personality_decl)
140     cp_eh_personality_decl = build_personality_function ("gxx");
141 
142   return cp_eh_personality_decl;
143 }
144 
145 /* This is a subroutine of fold_cplus_constants.  It returns TRUE if T
146    is a C++ specific constant that needs to be folded further before
147    being passed to the debug info emitter.  */
148 
149 static bool
150 template_arg_needs_folding (const_tree t)
151 {
152   /* For now only PTRMEM_CST nodes are to be folded further.  */
153   if (TREE_CODE (t) == PTRMEM_CST)
154     return true;
155   return false;
156 }
157 
158 /* Fold the elements of the TREE_VEC C which are C++ specific nodes
159    that would need folding so that they can be processed by the debug
160    info emitter. This is a subroutine of
161    get_template_innermost_arguments_folded and
162    get_template_argument_pack_elems_folded.  */
163 
164 static tree
165 fold_cplus_constants (const_tree c)
166 {
167   tree folded_elems, elems = CONST_CAST_TREE (c);
168   int vec_len, i;
169 
170   if (elems == NULL_TREE || elems == error_mark_node)
171     return elems;
172 
173   vec_len = TREE_VEC_LENGTH (elems);
174 
175   /* First check if there is at least one element that needs
176      folding. If there is none, we just return ELEMS. Otherwise create
177      and return a new tree vector that contains the folded versions of
178      ELEMS. This is to avoid allocating memory if we don't need
179      to.  */
180   for (i = 0; i < vec_len; ++i)
181     {
182       if (template_arg_needs_folding (TREE_VEC_ELT (elems, i)))
183 	break;
184     }
185   if (i == vec_len)
186     return elems;
187 
188   folded_elems = make_tree_vec (vec_len);
189   for (i = 0; i < vec_len; ++i)
190     {
191       tree elem = TREE_VEC_ELT (elems, i);
192       TREE_VEC_ELT (folded_elems, i) =
193 	(elem && !TYPE_P (elem)) ? cplus_expand_constant (elem) : elem;
194 
195     }
196   return folded_elems;
197 }
198 
199 /* The C++ implementation of the LANG_HOOKS_GET_INNERMOST_GENERIC_ARGS
200    hook. It returns the innermost template arguments of type T, and
201    makes sure those arguments are folded enough for the debug info
202    emitter.  */
203 
204 static tree
205 get_template_innermost_arguments_folded (const_tree t)
206 {
207   return fold_cplus_constants (get_template_innermost_arguments (t));
208 }
209 
210 static tree
211 get_template_argument_pack_elems_folded (const_tree t)
212 {
213   return fold_cplus_constants (get_template_argument_pack_elems (t));
214 }
215 
216 /* The C++ version of the enum_underlying_base_type langhook.
217    See also cp/semantics.c (finish_underlying_type).  */
218 
219 static
220 tree cxx_enum_underlying_base_type (const_tree type)
221 {
222   tree underlying_type = ENUM_UNDERLYING_TYPE (type);
223 
224   if (! ENUM_FIXED_UNDERLYING_TYPE_P (type))
225     underlying_type
226       = c_common_type_for_mode (TYPE_MODE (underlying_type),
227                                 TYPE_UNSIGNED (underlying_type));
228 
229   return underlying_type;
230 }
231 
232 #include "gt-cp-cp-lang.h"
233 #include "gtype-cp.h"
234