m4_include(b4_pkgdatadir/[c++.m4])
+# 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_variant_if
+
+
+# b4_symbol_actions(FILENAME, LINENO,
+# SYMBOL-TAG, SYMBOL-NUM,
+# SYMBOL-ACTION, SYMBOL-TYPENAME)
+# -------------------------------------------------
+# Same as in C, but using references instead of pointers.
+m4_define([b4_symbol_actions],
+[m4_pushdef([b4_dollar_dollar],
+ [b4_symbol_value([yyvalue], [$6])])dnl
+m4_pushdef([b4_at_dollar], [yylocation])dnl
+ case $4: // $3
+b4_syncline([$2], [$1])
+ $5;
+b4_syncline([@oline@], [@ofile@])
+ break;
+m4_popdef([b4_at_dollar])dnl
+m4_popdef([b4_dollar_dollar])dnl
+])
+
+
+# b4_symbol_action_(SYMBOL-TAG, SYMBOL-NUM, SYMBOL-TYPENAME)
+# ----------------------------------------------------------
+# Invoke b4_dollar_dollar(SYMBOL_TYPENAME) for each symbol.
+m4_define([b4_symbol_action_],
+[m4_ifval($3,
+[ case $2: // $1
+ b4_dollar_dollar($@);
+ break;
+])])
+
+
+# b4_symbol_variant(YYTYPE, YYVAL, ACTION)
+# ----------------------------------------
+# 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>()])dnl
+ switch ($1)
+ {
+m4_map([b4_symbol_action_], m4_defn([b4_type_names]))
+ 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-TAG, SYMBOL-NUM, SYMBOL-TYPENAME)
+# -------------------------------------------------------
+# 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.
+# $3 is doubly-quoted, do not quote it again.
+m4_define([b4_char_sizeof],
+[m4_ifval($3,
+[
+ char _b4_char_sizeof_dummy@{sizeof($3)@}; // $1])dnl
+])
+
+
m4_define([b4_parser_class_name],
[b4_percent_define_get([[parser_class_name]])])
]b4_namespace_open[
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
+ {
+ /// Instantiate a \a T in here.
+ template <typename T>
+ inline void
+ build()
+ {
+ new (buffer) T;
+ }
+
+ /// Destroy the stored \a T.
+ template <typename T>
+ inline void
+ destroy()
+ {
+ reinterpret_cast<T&>(buffer).~T();
+ }
+
+ /// Accessor to a built \a T.
+ template <typename T>
+ inline T&
+ as()
+ {
+ return reinterpret_cast<T&>(buffer);
+ }
+
+ /// Const accessor to a built \a T (for %printer).
+ template <typename T>
+ inline const T&
+ as() const
+ {
+ return reinterpret_cast<const T&>(buffer);
+ }
+
+ /// A buffer large enough to store any of the semantic values.
+ char buffer[S];
+ };
+]])[
]b4_namespace_close[
#include "location.hh"
class ]b4_parser_class_name[
{
public:
- /// Symbol semantic values.
#ifndef YYSTYPE
-]m4_ifdef([b4_stype],
+]b4_variant_if(
+[ /// An auxiliary type to compute the largest semantic type.
+ union union_type
+ {]m4_map([b4_char_sizeof], m4_defn([b4_type_names]))[
+ };
+
+ /// Symbol semantic values.
+ typedef variant<sizeof(union_type)> semantic_type;],
+[ /// Symbol semantic values.
+m4_ifdef([b4_stype],
[ union semantic_type
- {
-b4_user_stype
+ {b4_user_stype
};],
[m4_if(b4_tag_seen_flag, 0,
[[ typedef int semantic_type;]],
-[[ typedef YYSTYPE semantic_type;]])])[
+[[ typedef YYSTYPE semantic_type;]])])])[
#else
typedef YYSTYPE semantic_type;
#endif
#if YYDEBUG
/// \brief Report a symbol value on the debug stream.
/// \param yytype The token type.
- /// \param yyvaluep Its semantic value.
- /// \param yylocationp Its location.
+ /// \param yyvalue Its semantic value.
+ /// \param yylocation Its location.
virtual void yy_symbol_value_print_ (int yytype,
- const semantic_type* yyvaluep,
- const location_type* yylocationp);
+ const semantic_type& yyvalue,
+ const location_type& yylocation);
/// \brief Report a symbol on the debug stream.
/// \param yytype The token type.
- /// \param yyvaluep Its semantic value.
- /// \param yylocationp Its location.
+ /// \param yyvalue Its semantic value.
+ /// \param yylocation Its location.
virtual void yy_symbol_print_ (int yytype,
- const semantic_type* yyvaluep,
- const location_type* yylocationp);
+ const semantic_type& yyvalue,
+ const location_type& yylocation);
#endif
/// \brief Reclaim the memory associated to a symbol.
/// \param yymsg Why this token is reclaimed.
/// \param yytype The symbol type.
- /// \param yyvaluep Its semantic value.
- /// \param yylocationp Its location.
+ /// \param yyvalue Its semantic value.
+ /// \param yylocation Its location.
inline void yydestruct_ (const char* yymsg,
int yytype,
- semantic_type* yyvaluep,
- location_type* yylocationp);
+ semantic_type& yyvalue,
+ location_type& yylocation);
+
+ /// Push a new state on the stack.
+ /// \warning the contents of \a v is stolen.
+ inline void yypush_ (state_type s,
+ semantic_type& v, const location_type& l);
/// Pop \a n symbols the three stacks.
inline void yypop_ (unsigned int n = 1);
inline void
]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
- const semantic_type* yyvaluep, const location_type* yylocationp)
+ const semantic_type& yyvalue, const location_type& yylocation)
{
- YYUSE (yylocationp);
- YYUSE (yyvaluep);
+ YYUSE (yylocation);
+ YYUSE (yyvalue);
switch (yytype)
{
]m4_map([b4_symbol_actions], m4_defn([b4_symbol_printers]))dnl
void
]b4_parser_class_name[::yy_symbol_print_ (int yytype,
- const semantic_type* yyvaluep, const location_type* yylocationp)
+ const semantic_type& yyvalue, const location_type& yylocation)
{
*yycdebug_ << (yytype < yyntokens_ ? "token" : "nterm")
<< ' ' << yytname_[yytype] << " ("
- << *yylocationp << ": ";
- yy_symbol_value_print_ (yytype, yyvaluep, yylocationp);
+ << yylocation << ": ";
+ yy_symbol_value_print_ (yytype, yyvalue, yylocation);
*yycdebug_ << ')';
}
#endif
void
]b4_parser_class_name[::yydestruct_ (const char* yymsg,
- int yytype, semantic_type* yyvaluep, location_type* yylocationp)
+ int yytype, semantic_type& yyvalue, location_type& yylocation)
{
- YYUSE (yylocationp);
YYUSE (yymsg);
- YYUSE (yyvaluep);
+ YYUSE (yyvalue);
+ YYUSE (yylocation);
- YY_SYMBOL_PRINT (yymsg, yytype, yyvaluep, yylocationp);
+ YY_SYMBOL_PRINT (yymsg, yytype, yyvalue, yylocation);
switch (yytype)
{
}
}
+ void
+ ]b4_parser_class_name[::yypush_ (state_type s,
+ semantic_type& v, const location_type& l)
+ {
+ yystate_stack_.push (s);
+ yysemantic_stack_.push (v);
+ yylocation_stack_.push (l);
+ }
+
void
]b4_parser_class_name[::yypop_ (unsigned int n)
{
yystate_stack_ = state_stack_type (0);
yysemantic_stack_ = semantic_stack_type (0);
yylocation_stack_ = location_stack_type (0);
- yysemantic_stack_.push (yylval);
- yylocation_stack_.push (yylloc);
+ yypush_ (yystate, yylval, yylloc);
- /* New state. */
+ // A new state was pushed on the stack.
+ // Invariant: yystate == yystack_[0].state, i.e.,
+ // yystate was just pushed onto the state stack.
yynewstate:
- yystate_stack_.push (yystate);
YYCDEBUG << "Entering state " << yystate << std::endl;
/* Accept? */
else
{
yytoken = yytranslate_ (yychar);
- YY_SYMBOL_PRINT ("Next token is", yytoken, &yylval, &yylloc);
+ YY_SYMBOL_PRINT ("Next token is", yytoken, yylval, yylloc);
}
/* If the proper action on seeing token YYTOKEN is to reduce or to
}
/* Shift the lookahead token. */
- YY_SYMBOL_PRINT ("Shifting", yytoken, &yylval, &yylloc);
+ YY_SYMBOL_PRINT ("Shifting", yytoken, yylval, yylloc);
/* Discard the token being shifted. */
yychar = yyempty_;
- yysemantic_stack_.push (yylval);
- yylocation_stack_.push (yylloc);
-
/* Count tokens shifted since error; after three, turn off error
status. */
if (yyerrstatus_)
--yyerrstatus_;
yystate = yyn;
+ yypush_ (yystate, yylval, yylloc);
goto yynewstate;
/*-----------------------------------------------------------.
| yyreduce -- Do a reduction. |
`-----------------------------*/
yyreduce:
- yylen = yyr2_[yyn];
+ yylen = yyr2_[yyn];]b4_variant_if([
+ /* Variants are always initialized to an empty instance of the
+ correct type. The default $$=$1 rule is NOT applied when using
+ variants */
+ ]b4_symbol_variant([[yyr1_@{yyn@}]], [yyval], [build])[],[
/* If YYLEN is nonzero, implement the default value of the action:
`$$ = $1'. Otherwise, use the top of the stack.
This behavior is undocumented and Bison
users should not rely upon it. */
if (yylen)
- yyval = yysemantic_stack_[yylen - 1];
+ yyval = yysemantic_stack_@{yylen - 1@};
else
- yyval = yysemantic_stack_[0];
+ yyval = yysemantic_stack_@{0@};])[
{
slice<location_type, location_stack_type> slice (yylocation_stack_, yylen);
default:
break;
}
- YY_SYMBOL_PRINT ("-> $$ =", yyr1_[yyn], &yyval, &yyloc);
+ YY_SYMBOL_PRINT ("-> $$ =", yyr1_[yyn], yyval, yyloc);
yypop_ (yylen);
yylen = 0;
YY_STACK_PRINT ();
- yysemantic_stack_.push (yyval);
- yylocation_stack_.push (yyloc);
-
/* Shift the result of the reduction. */
yyn = yyr1_[yyn];
yystate = yypgoto_[yyn - yyntokens_] + yystate_stack_[0];
yystate = yytable_[yystate];
else
yystate = yydefgoto_[yyn - yyntokens_];
+ yypush_ (yystate, yyval, yyloc);
goto yynewstate;
/*------------------------------------.
}
else
{
- yydestruct_ ("Error: discarding", yytoken, &yylval, &yylloc);
+ yydestruct_ ("Error: discarding", yytoken, yylval, yylloc);
yychar = yyempty_;
}
}
}
/* Pop the current state because it cannot handle the error token. */
- if (yystate_stack_.height () == 1)
+ if (yystate_stack_.size () == 1)
YYABORT;
yyerror_range[0] = yylocation_stack_[0];
yydestruct_ ("Error: popping",
yystos_[yystate],
- &yysemantic_stack_[0], &yylocation_stack_[0]);
+ yysemantic_stack_[0], yylocation_stack_[0]);
yypop_ ();
yystate = yystate_stack_[0];
YY_STACK_PRINT ();
// Using YYLLOC is tempting, but would change the location of
// the lookahead. YYLOC is available though.
YYLLOC_DEFAULT (yyloc, (yyerror_range - 1), 2);
- yysemantic_stack_.push (yylval);
- yylocation_stack_.push (yyloc);
/* Shift the error token. */
YY_SYMBOL_PRINT ("Shifting", yystos_[yyn],
- &yysemantic_stack_[0], &yylocation_stack_[0]);
+ yysemantic_stack_[0], yylocation_stack_[0]);
yystate = yyn;
+ yypush_ (yystate, yylval, yyloc);
goto yynewstate;
/* Accept. */
yyreturn:
if (yychar != yyempty_)
- yydestruct_ ("Cleanup: discarding lookahead", yytoken, &yylval, &yylloc);
+ yydestruct_ ("Cleanup: discarding lookahead", yytoken, yylval, yylloc);
/* Do not reclaim the symbols of the rule which action triggered
this YYABORT or YYACCEPT. */
yypop_ (yylen);
- while (yystate_stack_.height () != 1)
+ while (yystate_stack_.size () != 1)
{
yydestruct_ ("Cleanup: popping",
- yystos_[yystate_stack_[0]],
- &yysemantic_stack_[0],
- &yylocation_stack_[0]);
+ yystos_[yystate_stack_[0]],
+ yysemantic_stack_[0],
+ yylocation_stack_[0]);
yypop_ ();
}
for (int yyi = 0; yyi < yynrhs; yyi++)
YY_SYMBOL_PRINT (" $" << yyi + 1 << " =",
yyrhs_[yyprhs_[yyrule] + yyi],
- &]b4_rhs_value(yynrhs, yyi + 1)[,
- &]b4_rhs_location(yynrhs, yyi + 1)[);
+ ]b4_rhs_value(yynrhs, yyi + 1)[,
+ ]b4_rhs_location(yynrhs, yyi + 1)[);
}
#endif // YYDEBUG
}
inline
- unsigned int
- height () const
+ 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 (); }
+ inline const_iterator end () const { return seq_.rend (); }
private:
-
+ /// The wrapped container.
S seq_;
};
projects / bison.git / blobdiff