data/c++.m4

   1                                                             -*- Autoconf -*-
   2
   3 # C++ skeleton for Bison
   4
   5 # Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free
   6 # Software Foundation, Inc.
   7
   8 # This program is free software: you can redistribute it and/or modify
   9 # it under the terms of the GNU General Public License as published by
  10 # the Free Software Foundation, either version 3 of the License, or
  11 # (at your option) any later version.
  12 #
  13 # This program is distributed in the hope that it will be useful,
  14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 # GNU General Public License for more details.
  17 #
  18 # You should have received a copy of the GNU General Public License
  19 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20
  21 m4_include(b4_pkgdatadir/[c.m4])
  22
  23 ## ---------------- ##
  24 ## Default values.  ##
  25 ## ---------------- ##
  26
  27 # Default parser class name.
  28 b4_percent_define_default([[parser_class_name]], [[parser]])
  29 b4_percent_define_default([[location_type]], [[location]])
  30 b4_percent_define_default([[filename_type]], [[std::string]])
  31 b4_percent_define_default([[namespace]], m4_defn([b4_prefix]))
  32 b4_percent_define_default([[global_tokens_and_yystype]], [[false]])
  33 b4_percent_define_default([[define_location_comparison]],
  34                           [m4_if(b4_percent_define_get([[filename_type]]),
  35                                  [std::string], [[true]], [[false]])])
  36
  37
  38 ## ----------- ##
  39 ## Namespace.  ##
  40 ## ----------- ##
  41
  42 m4_define([b4_namespace_ref], [b4_percent_define_get([[namespace]])])
  43
  44 # Don't permit an empty b4_namespace_ref.  Any `::parser::foo' appended to it
  45 # would compile as an absolute reference with `parser' in the global namespace.
  46 # b4_namespace_open would open an anonymous namespace and thus establish
  47 # internal linkage.  This would compile.  However, it's cryptic, and internal
  48 # linkage for the parser would be specified in all translation units that
  49 # include the header, which is always generated.  If we ever need to permit
  50 # internal linkage somehow, surely we can find a cleaner approach.
  51 m4_if(m4_bregexp(b4_namespace_ref, [^[   ]*$]), [-1], [],
  52 [b4_complain_at(b4_percent_define_get_loc([[namespace]]),
  53                 [[namespace reference is empty]])])
  54
  55 # Instead of assuming the C++ compiler will do it, Bison should reject any
  56 # invalid b4_namepsace_ref that would be converted to a valid
  57 # b4_namespace_open.  The problem is that Bison doesn't always output
  58 # b4_namespace_ref to uncommented code but should reserve the ability to do so
  59 # in future releases without risking breaking any existing user grammars.
  60 # Specifically, don't allow empty names as b4_namespace_open would just convert
  61 # those into anonymous namespaces, and that might tempt some users.
  62 m4_if(m4_bregexp(b4_namespace_ref, [::[  ]*::]), [-1], [],
  63 [b4_complain_at(b4_percent_define_get_loc([[namespace]]),
  64                 [[namespace reference has consecutive "::"]])])
  65 m4_if(m4_bregexp(b4_namespace_ref, [::[  ]*$]), [-1], [],
  66 [b4_complain_at(b4_percent_define_get_loc([[namespace]]),
  67                 [[namespace reference has a trailing "::"]])])
  68
  69 m4_define([b4_namespace_open],
  70 [b4_user_code([b4_percent_define_get_syncline([[namespace]])
  71 [namespace ]m4_bpatsubst(m4_dquote(m4_bpatsubst(m4_dquote(b4_namespace_ref),
  72                                                 [^\(.\)[         ]*::], [\1])),
  73                          [::], [ { namespace ])[ {]])])
  74
  75 m4_define([b4_namespace_close],
  76 [b4_user_code([b4_percent_define_get_syncline([[namespace]])
  77 m4_bpatsubst(m4_dquote(m4_bpatsubst(m4_dquote(b4_namespace_ref[ ]),
  78                                     [^\(.\)[     ]*\(::\)?\([^][:]\|:[^:]\)*],
  79                                     [\1])),
  80              [::\([^][:]\|:[^:]\)*], [} ])[} // ]b4_namespace_ref])])
  81
  82
  83 # b4_token_enums(LIST-OF-PAIRS-TOKEN-NAME-TOKEN-NUMBER)
  84 # -----------------------------------------------------
  85 # Output the definition of the tokens as enums.
  86 m4_define([b4_token_enums],
  87 [/* Tokens.  */
  88    enum yytokentype {
  89 m4_map_sep([     b4_token_enum], [,
  90 ],
  91            [$@])
  92    };
  93 ])
  94
  95
  96 ## ----------------- ##
  97 ## Semantic Values.  ##
  98 ## ----------------- ##
  99
 100
 101 # b4_lhs_value([TYPE])
 102 # --------------------
 103 # Expansion of $<TYPE>$.
 104 m4_define([b4_lhs_value],
 105 [(yyval[]m4_ifval([$1], [.$1]))])
 106
 107
 108 # b4_rhs_value(RULE-LENGTH, NUM, [TYPE])
 109 # --------------------------------------
 110 # Expansion of $<TYPE>NUM, where the current rule has RULE-LENGTH
 111 # symbols on RHS.
 112 m4_define([b4_rhs_value],
 113 [(yysemantic_stack_@{($1) - ($2)@}m4_ifval([$3], [.$3]))])
 114
 115 # b4_lhs_location()
 116 # -----------------
 117 # Expansion of @$.
 118 m4_define([b4_lhs_location],
 119 [(yyloc)])
 120
 121
 122 # b4_rhs_location(RULE-LENGTH, NUM)
 123 # ---------------------------------
 124 # Expansion of @NUM, where the current rule has RULE-LENGTH symbols
 125 # on RHS.
 126 m4_define([b4_rhs_location],
 127 [(yylocation_stack_@{($1) - ($2)@})])
 128
 129
 130 # b4_parse_param_decl
 131 # -------------------
 132 # Extra formal arguments of the constructor.
 133 # Change the parameter names from "foo" into "foo_yyarg", so that
 134 # there is no collision bw the user chosen attribute name, and the
 135 # argument name in the constructor.
 136 m4_define([b4_parse_param_decl],
 137 [m4_ifset([b4_parse_param],
 138           [m4_map_sep([b4_parse_param_decl_1], [, ], [b4_parse_param])])])
 139
 140 m4_define([b4_parse_param_decl_1],
 141 [$1_yyarg])
 142
 143
 144
 145 # b4_parse_param_cons
 146 # -------------------
 147 # Extra initialisations of the constructor.
 148 m4_define([b4_parse_param_cons],
 149           [m4_ifset([b4_parse_param],
 150                     [
 151       b4_cc_constructor_calls(b4_parse_param)])])
 152 m4_define([b4_cc_constructor_calls],
 153           [m4_map_sep([b4_cc_constructor_call], [,
 154       ], [$@])])
 155 m4_define([b4_cc_constructor_call],
 156           [$2 ($2_yyarg)])
 157
 158 # b4_parse_param_vars
 159 # -------------------
 160 # Extra instance variables.
 161 m4_define([b4_parse_param_vars],
 162           [m4_ifset([b4_parse_param],
 163                     [
 164     /* User arguments.  */
 165 b4_cc_var_decls(b4_parse_param)])])
 166 m4_define([b4_cc_var_decls],
 167           [m4_map_sep([b4_cc_var_decl], [
 168 ], [$@])])
 169 m4_define([b4_cc_var_decl],
 170           [    $1;])