# b4_symbol_value_template(VAL, [TYPE])
# -------------------------------------
-# Same as b4_symbol_value, but used in a template method.
+# Same as b4_symbol_value, but used in a template method. It makes
+# a difference when using variants.
m4_copy([b4_symbol_value], [b4_symbol_value_template])
-# How the semantic value is extracted when using variants.
-b4_variant_if([
- # b4_symbol_value(VAL, [TYPE])
- # ----------------------------
- m4_define([b4_symbol_value],
- [m4_ifval([$2],
- [$1.as< $2 >()],
- [$1])])
-
- # b4_symbol_value_template(VAL, [TYPE])
- # -------------------------------------
- # Same as b4_symbol_value, but used in a template method.
- m4_define([b4_symbol_value_template],
- [m4_ifval([$2],
- [$1.template as< $2 >()],
- [$1])])
-]) # b4_variant_if
-
# b4_lex_symbol_if([IF-YYLEX-RETURNS-A-COMPLETE-SYMBOL], [IF-NOT])
# ----------------------------------------------------------------
# --------------------
# Expansion of $<TYPE>$.
m4_define([b4_lhs_value],
-[b4_symbol_value([yylhs.value], [$1])])
+ [b4_symbol_value([yylhs.value], [$1])])
# b4_lhs_location()
# -----------------
# Expansion of @$.
m4_define([b4_lhs_location],
-[yylhs.location])
+ [yylhs.location])
# b4_rhs_data(RULE-LENGTH, NUM)
m4_define([b4_rhs_location],
[b4_rhs_data([$1], [$2]).location])
+
# b4_symbol_action(SYMBOL-NUM, KIND)
# ----------------------------------
# Run the action KIND (destructor or printer) for SYMBOL-NUM.
b4_symbol_foreach([b4_symbol_constructor_definition_])])])
-# b4_symbol_variant(YYTYPE, YYVAL, ACTION, [ARGS])
-# ------------------------------------------------
-# Run some ACTION ("build", or "destroy") on YYVAL of symbol type
-# YYTYPE.
-m4_define([b4_symbol_variant],
-[m4_pushdef([b4_dollar_dollar],
- [$2.$3< $][3 >(m4_shift3($@))])dnl
- switch ($1)
- {
-b4_type_foreach([b4_type_action_])[]dnl
- default:
- break;
- }
-m4_popdef([b4_dollar_dollar])dnl
-])
-
-
-# _b4_char_sizeof_counter
-# -----------------------
-# A counter used by _b4_char_sizeof_dummy to create fresh symbols.
-m4_define([_b4_char_sizeof_counter],
-[0])
-
-# _b4_char_sizeof_dummy
-# ---------------------
-# At each call return a new C++ identifier.
-m4_define([_b4_char_sizeof_dummy],
-[m4_define([_b4_char_sizeof_counter], m4_incr(_b4_char_sizeof_counter))dnl
-dummy[]_b4_char_sizeof_counter])
-
-
-# b4_char_sizeof_(SYMBOL-NUM)
-# ---------------------------
-# A comment describing this symbol.
-m4_define([b4_char_sizeof_],
-[ // b4_symbol([$1], [tag])
-])
-
-# b4_char_sizeof(SYMBOL-NUMS)
-# --------------------------
-# To be mapped on the list of type names to produce:
-#
-# char dummy1[sizeof(type_name_1)];
-# char dummy2[sizeof(type_name_2)];
-#
-# for defined type names.
-m4_define([b4_char_sizeof],
-[b4_symbol_if([$1], [has_type],
-[
-m4_map([b4_char_sizeof_], [$@])dnl
- char _b4_char_sizeof_dummy@{sizeof([b4_symbol([$1], [type])])@};
-])])
-
-
# b4_yytranslate_definition
# -------------------------
# Define yytranslate_. Sometimes we want it in the header file,
m4_define([b4_location_constructors])
m4_include(b4_pkgdatadir/[location.cc])])
m4_include(b4_pkgdatadir/[stack.hh])
+b4_variant_if([m4_include(b4_pkgdatadir/[variant.hh])])
# We do want M4 expansion after # for CPP macros.
m4_changecom()
]b4_namespace_open[
]b4_locations_if([ class position;
class location;])[
-]b4_variant_if(
-[[
- /// A char[S] buffer to store and retrieve objects.
- ///
- /// Sort of a variant, but does not keep track of the nature
- /// of the stored data, since that knowledge is available
- /// via the current state.
- template <size_t S>
- struct variant
- {]b4_assert_if([
- /// Whether something is contained.
- bool built;
-])[
- /// Empty construction.
- inline
- variant ()]b4_assert_if([
- : built(false)])[
- {}
-
- /// Instantiate a \a T in here.
- template <typename T>
- inline T&
- build()
- {]b4_assert_if([
- assert(!built);
- built = true;])[
- return *new (buffer.raw) T;
- }
-
- /// Instantiate a \a T in here from \a t.
- template <typename T>
- inline T&
- build(const T& t)
- {]b4_assert_if([
- assert(!built);
- built = true;])[
- return *new (buffer.raw) T(t);
- }
-
- /// Construct and fill.
- template <typename T>
- inline
- variant (const T& t)]b4_assert_if([
- : built(true)])[
- {
- new (buffer.raw) T(t);
- }
-
- /// Accessor to a built \a T.
- template <typename T>
- inline T&
- as()
- {]b4_assert_if([
- assert(built);])[
- return reinterpret_cast<T&>(buffer.raw);
- }
-
- /// Const accessor to a built \a T (for %printer).
- template <typename T>
- inline const T&
- as() const
- {]b4_assert_if([
- assert(built);])[
- return reinterpret_cast<const T&>(buffer.raw);
- }
-
- /// Swap the content with \a other.
- template <typename T>
- inline void
- swap(variant<S>& other)
- {
- std::swap(as<T>(), other.as<T>());
- }
-
- /// Assign the content of \a other to this.
- /// Destroys \a other.
- template <typename T>
- inline void
- build(variant<S>& other)
- {
- build<T>();
- swap<T>(other);
- other.destroy<T>();
- }
-
- /// Destroy the stored \a T.
- template <typename T>
- inline void
- destroy()
- {
- as<T>().~T();]b4_assert_if([
- built = false;])[
- }
-
- /// A buffer large enough to store any of the semantic values.
- /// Long double is chosen as it has the strongest alignment
- /// constraints.
- union {
- long double align_me;
- char raw[S];
- } buffer;
- };
-]])[
+]b4_variant_if([b4_variant_definition])[
]b4_namespace_close[
]b4_locations_if([#include "location.hh"])[
/* Variants are always initialized to an empty instance of the
correct type. The default $$=$1 rule is NOT applied when using
variants */
- ]b4_symbol_variant([[yyr1_@{yyn@}]], [yylhs.value], [build])[],[
+ ]b4_symbol_variant([[yyr1_@{yyn@}]], [yylhs.value], [build]),[
/* If YYLEN is nonzero, implement the default value of the action:
`$$ = $1'. Otherwise, use the top of the stack.
--- /dev/null
+# C++ skeleton for Bison
+
+# Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008
+# Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+
+## --------- ##
+## variant. ##
+## --------- ##
+
+# b4_symbol_variant(YYTYPE, YYVAL, ACTION, [ARGS])
+# ------------------------------------------------
+# Run some ACTION ("build", or "destroy") on YYVAL of symbol type
+# YYTYPE.
+m4_define([b4_symbol_variant],
+[m4_pushdef([b4_dollar_dollar],
+ [$2.$3< $][3 >(m4_shift3($@))])dnl
+ switch ($1)
+ {
+b4_type_foreach([b4_type_action_])[]dnl
+ default:
+ break;
+ }
+m4_popdef([b4_dollar_dollar])dnl
+])
+
+
+# _b4_char_sizeof_counter
+# -----------------------
+# A counter used by _b4_char_sizeof_dummy to create fresh symbols.
+m4_define([_b4_char_sizeof_counter],
+[0])
+
+# _b4_char_sizeof_dummy
+# ---------------------
+# At each call return a new C++ identifier.
+m4_define([_b4_char_sizeof_dummy],
+[m4_define([_b4_char_sizeof_counter], m4_incr(_b4_char_sizeof_counter))dnl
+dummy[]_b4_char_sizeof_counter])
+
+
+# b4_char_sizeof_(SYMBOL-NUM)
+# ---------------------------
+# A comment describing this symbol.
+m4_define([b4_char_sizeof_],
+[ // b4_symbol([$1], [tag])
+])
+
+# b4_char_sizeof(SYMBOL-NUMS)
+# ---------------------------
+# To be mapped on the list of type names to produce:
+#
+# char dummy1[sizeof(type_name_1)];
+# char dummy2[sizeof(type_name_2)];
+#
+# for defined type names.
+m4_define([b4_char_sizeof],
+[b4_symbol_if([$1], [has_type],
+[
+m4_map([b4_char_sizeof_], [$@])dnl
+ char _b4_char_sizeof_dummy@{sizeof([b4_symbol([$1], [type])])@};
+])])
+
+
+# b4_variant_definition
+# ---------------------
+# Define "variant".
+m4_define([b4_variant_definition],
+[[
+ /// A char[S] buffer to store and retrieve objects.
+ ///
+ /// Sort of a variant, but does not keep track of the nature
+ /// of the stored data, since that knowledge is available
+ /// via the current state.
+ template <size_t S>
+ struct variant
+ {]b4_assert_if([
+ /// Whether something is contained.
+ bool built;
+])[
+ /// Empty construction.
+ inline
+ variant ()]b4_assert_if([
+ : built (false)])[
+ {}
+
+ /// Instantiate a \a T in here.
+ template <typename T>
+ inline T&
+ build ()
+ {]b4_assert_if([
+ assert (!built);
+ built = true;])[
+ return *new (buffer.raw) T;
+ }
+
+ /// Instantiate a \a T in here from \a t.
+ template <typename T>
+ inline T&
+ build (const T& t)
+ {]b4_assert_if([
+ assert(!built);
+ built = true;])[
+ return *new (buffer.raw) T(t);
+ }
+
+ /// Construct and fill.
+ template <typename T>
+ inline
+ variant (const T& t)]b4_assert_if([
+ : built (true)])[
+ {
+ new (buffer.raw) T(t);
+ }
+
+ /// Accessor to a built \a T.
+ template <typename T>
+ inline T&
+ as ()
+ {]b4_assert_if([
+ assert (built);])[
+ return reinterpret_cast<T&>(buffer.raw);
+ }
+
+ /// Const accessor to a built \a T (for %printer).
+ template <typename T>
+ inline const T&
+ as () const
+ {]b4_assert_if([
+ assert(built);])[
+ return reinterpret_cast<const T&>(buffer.raw);
+ }
+
+ /// Swap the content with \a other.
+ template <typename T>
+ inline void
+ swap (variant<S>& other)
+ {
+ std::swap (as<T>(), other.as<T>());
+ }
+
+ /// Assign the content of \a other to this.
+ /// Destroys \a other.
+ template <typename T>
+ inline void
+ build (variant<S>& other)
+ {
+ build<T>();
+ swap<T>(other);
+ other.destroy<T>();
+ }
+
+ /// Destroy the stored \a T.
+ template <typename T>
+ inline void
+ destroy ()
+ {
+ as<T>().~T();]b4_assert_if([
+ built = false;])[
+ }
+
+ /// A buffer large enough to store any of the semantic values.
+ /// Long double is chosen as it has the strongest alignment
+ /// constraints.
+ union
+ {
+ long double align_me;
+ char raw[S];
+ } buffer;
+ };
+]])
+
+
+## -------------------------- ##
+## Adjustments for variants. ##
+## -------------------------- ##
+
+
+# How the semantic value is extracted when using variants.
+
+# b4_symbol_value(VAL, [TYPE])
+# ----------------------------
+m4_define([b4_symbol_value],
+[m4_ifval([$2],
+ [$1.as< $2 >()],
+ [$1])])
+
+# b4_symbol_value_template(VAL, [TYPE])
+# -------------------------------------
+# Same as b4_symbol_value, but used in a template method.
+m4_define([b4_symbol_value_template],
+[m4_ifval([$2],
+ [$1.template as< $2 >()],
+ [$1])])
projects / bison.git / commitdiff
