gcc/cp/cp-lang.c

   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
 233 #include "gt-cp-cp-lang.h"
 234 #include "gtype-cp.h"