# 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)
# b4_rhs_state(RULE-LENGTH, NUM)
-# -----------------------------
+# ------------------------------
# The state corresponding to the symbol #NUM, where the current
# rule has RULE-LENGTH symbols on RHS.
m4_define([b4_rhs_state],
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.
# ----------------------------------
# Define the overloaded versions of make_symbol for all the value types.
m4_define([b4_symbol_constructor_definitions],
-[[ // symbol_base_type.
- template <typename Exact>
- ]b4_parser_class_name[::symbol_base_type<Exact>::symbol_base_type ()
- : value()]b4_locations_if([
- , location()])[
- {
- }]b4_locations_if([[
-
- template <typename Exact>
- ]b4_parser_class_name[::symbol_base_type<Exact>::symbol_base_type (const location_type& l)
- : value()
- , location(l)
- {
- }]])[
-
- template <typename Exact>
- ]b4_parser_class_name[::symbol_base_type<Exact>::symbol_base_type (]b4_args(
- [const semantic_type& v],
- b4_locations_if([const location_type& l]))[)
- : value(v)]b4_locations_if([
- , location(l)])[
- {
- }
-
- template <typename Exact>
- const Exact&
- ]b4_parser_class_name[::symbol_base_type<Exact>::self () const
- {
- return static_cast<const Exact&>(*this);
- }
-
- template <typename Exact>
- Exact&
- ]b4_parser_class_name[::symbol_base_type<Exact>::self ()
- {
- return static_cast<Exact&>(*this);
- }
-
- template <typename Exact>
- int
- ]b4_parser_class_name[::symbol_base_type<Exact>::type_get () const
- {
- return self ().type_get_ ();
- }
-
- // symbol_type.
- ]b4_parser_class_name[::symbol_type::symbol_type ()
- : super_type ()
- , type ()
- {
- }
-
- ]b4_parser_class_name[::symbol_type::symbol_type (]b4_args(
- [int t],
- b4_locations_if([const location_type& l]))[)
- : super_type (]b4_locations_if([l])[)
- , type (t)
- {
- }
-
- ]b4_parser_class_name[::symbol_type::symbol_type (]b4_args(
- [int t],
- [const semantic_type& v],
- b4_locations_if([const location_type& l]))[)
- : super_type (v]b4_locations_if([, l])[)
- , type (t)
- {
- }
-
- int
- ]b4_parser_class_name[::symbol_type::type_get_ () const
- {
- return type;
- }
-]b4_lex_symbol_if([[
- ]b4_parser_class_name[::token_type
- ]b4_parser_class_name[::symbol_type::token () const
- {
- // YYTOKNUM[NUM] -- (External) token number corresponding to the
- // (internal) symbol number NUM (which must be that of a token). */
- static
- const ]b4_int_type_for([b4_toknum])[
- yytoken_number_[] =
- {
- ]b4_toknum[
- };
- return static_cast<token_type> (yytoken_number_[type]);
- }
-]])[
-
-]b4_variant_if(
-[ // Implementation of make_symbol for each symbol type.
+[b4_variant_if([
+ // Implementation of make_symbol for each symbol type.
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,
[# Backward compatibility.
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) 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) T(t);
- }
-
- /// Construct and fill.
- template <typename T>
- inline
- variant (const T& t)]b4_assert_if([
- : built(true)])[
- {
- new (buffer) T(t);
- }
-
- /// Accessor to a built \a T.
- template <typename T>
- inline T&
- as()
- {]b4_assert_if([
- assert(built);])[
- return reinterpret_cast<T&>(buffer);
- }
-
- /// 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);
- }
-
- /// 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.
- char buffer[S];
- };
-]])[
+]b4_variant_if([b4_variant_definition])[
]b4_namespace_close[
]b4_locations_if([#include "location.hh"])[
class ]b4_parser_class_name[
{
public:
-#ifndef YYSTYPE
-]b4_variant_if(
-[ /// An auxiliary type to compute the largest semantic type.
- union union_type
- {]b4_type_foreach([b4_char_sizeof])[};
-
- /// Symbol semantic values.
- typedef variant<sizeof(union_type)> semantic_type;],
-[ /// Symbol semantic values.
-m4_ifdef([b4_stype],
-[ union semantic_type
- {b4_user_stype
- };],
-[m4_if(b4_tag_seen_flag, 0,
-[[ typedef int semantic_type;]],
-[[ typedef YYSTYPE semantic_type;]])])])[
-#else
- typedef YYSTYPE semantic_type;
-#endif]b4_locations_if([
- /// Symbol locations.
- typedef b4_percent_define_get([[location_type]]) location_type;])[
- /// Tokens.
- struct token
- {
- ]b4_token_enums(b4_tokens)[
- };
- /// Token type.
- typedef token::yytokentype token_type;
-
+]b4_public_types_declare[
+]b4_symbol_constructor_declarations[
/// Build a parser object.
]b4_parser_class_name[ (]b4_parse_param_decl[);
virtual ~]b4_parser_class_name[ ();
void set_debug_level (debug_level_type l);
#endif
- private:
/// Report a syntax error.]b4_locations_if([
/// \param loc where the syntax error is found.])[
/// \param msg a description of the syntax error.
virtual void error (]b4_locations_if([const location_type& loc, ])[const std::string& msg);
+ private:
/// Generate an error message.
/// \param state the state where the error occurred.
/// \param tok the lookahead token.
/// Convert a scanner token number \a t to a symbol number.
static inline token_number_type yytranslate_ (]b4_lex_symbol_if([token_type], [int])[ t);
- /// A complete symbol, with its type.
- template <typename Exact>
- struct symbol_base_type
- {
- /// Default constructor.
- inline symbol_base_type ();
-
- /// Constructor.]b4_locations_if([
- inline symbol_base_type (const location_type& l)])[;
- inline symbol_base_type (]b4_args(
- [const semantic_type& v],
- b4_locations_if([const location_type& l]))[);
-
- /// Return this with its exact type.
- const Exact& self () const;
- Exact& self ();
-
- /// Return the type of this symbol.
- int type_get () const;
-
- /// The semantic value.
- semantic_type value;]b4_locations_if([
-
- /// The location.
- location_type location;])[
- };
-
#if YYDEBUG
/// \brief Display a symbol type, value and location.
/// \param yyo The output stream.
inline void yy_destroy_ (const char* yymsg,
symbol_base_type<Exact>& yysym) const;
- public:
- /// Element of the stack: a state and its attributes.
- struct symbol_type : symbol_base_type<symbol_type>
- {
- /// The parent class.
- typedef symbol_base_type<symbol_type> super_type;
-
- /// Default constructor.
- inline symbol_type ();
-
- /// Constructor.
- inline symbol_type (]b4_args([int t],
- [const semantic_type& v],
- b4_locations_if([const location_type& l]))[);
-
- inline symbol_type (]b4_args([int t],
- b4_locations_if([const location_type& l]))[);
-
- /// The symbol type.
- int type;
-
- /// Return the type corresponding to this state.
- inline int type_get_ () const;
-
- /// Its token.
- inline token_type token () const;
- };
-
-]b4_symbol_constructor_declarations[
-
private:
/// Element of the stack: a state and its attributes.
struct stack_symbol_type : symbol_base_type<stack_symbol_type>
]b4_parse_param_vars[
};
-]b4_lex_symbol_if([b4_yytranslate_definition])[
-]b4_lex_symbol_if([b4_symbol_constructor_definitions])[
+]b4_lex_symbol_if([b4_yytranslate_definition
+b4_public_types_define
+b4_symbol_constructor_definitions])[
]b4_namespace_close[
]b4_percent_define_flag_if([[global_tokens_and_yystype]],
| Symbol types. |
`---------------*/
-]b4_lex_symbol_if([], [b4_symbol_constructor_definitions])[
+]b4_lex_symbol_if([], [b4_public_types_define
+b4_symbol_constructor_definitions])[
// stack_symbol_type.
]b4_parser_class_name[::stack_symbol_type::stack_symbol_type ()
yyreduce:
yylen = yyr2_[yyn];]b4_variant_if([
/* Variants are always initialized to an empty instance of the
- correct type. The default $$=$1 rule is NOT applied when using
- variants */
- ]b4_symbol_variant([[yyr1_@{yyn@}]], [yylhs.value], [build])[],[
+ correct type. The default $$=$1 action is NOT applied when using
+ variants. */
+ ]b4_symbol_variant([[yyr1_@{yyn@}]], [yylhs.value], [build]),[
/* If YYLEN is nonzero, implement the default value of the action:
`$$ = $1'. Otherwise, use the top of the stack.
yylhs.state = yystate;
YY_SYMBOL_PRINT ("-> $$ =", yylhs);
]b4_variant_if([[
- // Destroy the lhs symbols.
+ // Destroy the rhs symbols.
for (int i = 0; i < yylen; ++i)
- // Destroy a variant which value may have be swapped with
- // yylhs.value. The value of yylhs.value (hence maybe one of
- // these lhs symbols) depends on what does the default
- // contruction for this type. In the case of pointers for
- // instance, nothing is done, so the value is junk. Therefore
- // do not try to report the content in the debug trace, it's
- // junk. Hence yymsg = 0. Besides, that keeps exactly the same
- // traces as with the other Bison skeletons.
+ // Destroy a variant which value may have been swapped with
+ // yylhs.value (for instance if the action was "std::swap($$,
+ // $1)"). The value of yylhs.value (hence possibly one of these
+ // rhs symbols) depends on the default contruction for this
+ // type. In the case of pointers for instance, no
+ // initialization is done, so the value is junk. Therefore do
+ // not try to report the value of symbols about to be destroyed
+ // in the debug trace, it's possibly junk. Hence yymsg = 0.
+ // Besides, that keeps exactly the same traces as with the other
+ // Bison skeletons.
yy_destroy_ (0, yystack_[i]);]])[
yypop_ (yylen);
yypush_ (0, yylhs);
goto yynewstate;
- /*------------------------------------.
- | yyerrlab -- here on detecting error |
- `------------------------------------*/
+ /*--------------------------------------.
+ | yyerrlab -- here on detecting error. |
+ `--------------------------------------*/
yyerrlab:
/* If not already recovering from an error, report this error. */
if (!yyerrstatus_)
]b4_lex_symbol_if([], [b4_yytranslate_definition])[
]b4_namespace_close[
-
]b4_epilogue[]dnl
-@output(b4_dir_prefix[]stack.hh@)@
-b4_copyright([Stack handling for Bison parsers in C++])[
-
-#ifndef BISON_STACK_HH
-# define BISON_STACK_HH
-
-#include <deque>
-
-]b4_namespace_open[
- template <class T, class S = std::deque<T> >
- class stack
- {
- public:
-
- // Hide our reversed order.
- typedef typename S::reverse_iterator iterator;
- typedef typename S::const_reverse_iterator const_iterator;
-
- stack () : seq_ ()
- {
- }
-
- stack (unsigned int n) : seq_ (n)
- {
- }
-
- inline
- T&
- operator [] (unsigned int i)
- {
- return seq_[i];
- }
-
- inline
- const T&
- operator [] (unsigned int i) const
- {
- return seq_[i];
- }
-
- inline
- void
- push (const T& t)
- {
- seq_.push_front (t);
- }
-
- inline
- void
- pop (unsigned int n = 1)
- {
- for (; n; --n)
- seq_.pop_front ();
- }
-
- inline
- typename S::size_type
- size () const
- {
- return seq_.size ();
- }
-
- inline const_iterator begin () const { return seq_.rbegin (); }
- inline const_iterator end () const { return seq_.rend (); }
-
- private:
- /// The wrapped container.
- S seq_;
- };
-
- /// Present a slice of the top of a stack.
- template <class T, class S = stack<T> >
- class slice
- {
- public:
-
- slice (const S& stack,
- unsigned int range) : stack_ (stack),
- range_ (range)
- {
- }
-
- inline
- const T&
- operator [] (unsigned int i) const
- {
- return stack_[range_ - i];
- }
-
- private:
-
- const S& stack_;
- unsigned int range_;
- };
-]b4_namespace_close[
-
-#endif // not BISON_STACK_HH[]dnl
-]
m4_divert_pop(0)
m4_popdef([b4_copyright_years])dnl
projects / bison.git / blobdiff