X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/0f0e1ace602fd8ded2457b1ea4f73c8fb2bfc6cc..5ab8c47bcf5088cf420db6e03cd44bfa68e92ca0:/data/lalr1.cc diff --git a/data/lalr1.cc b/data/lalr1.cc index 927466a2..de2c1def 100644 --- a/data/lalr1.cc +++ b/data/lalr1.cc @@ -1,7 +1,7 @@ # C++ skeleton for Bison -# Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, -# Inc. +# 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 @@ -18,6 +18,75 @@ 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_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 +# $3 is doubly-quoted, do not quote it again.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]])]) @@ -35,7 +104,7 @@ m4_divert_push(0)dnl b4_defines_if( [@output(b4_spec_defines_file@) b4_copyright([Skeleton interface for Bison LALR(1) parsers in C++], - [2002, 2003, 2004, 2005, 2006]) + [2002, 2003, 2004, 2005, 2006, 2007, 2008]) dnl FIXME: This is wrong, we want computed header guards. [ /* C++ LALR(1) parser skeleton written by Akim Demaille. */ @@ -52,6 +121,51 @@ dnl FIXME: This is wrong, we want computed header guards. ]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 + struct variant + { + /// Instantiate a \a T in here. + template + inline void + build() + { + new (buffer) T; + } + + /// Destroy the stored \a T. + template + inline void + destroy() + { + reinterpret_cast(buffer).~T(); + } + + /// Accessor to a built \a T. + template + inline T& + as() + { + return reinterpret_cast(buffer); + } + + /// Const accessor to a built \a T (for %printer). + template + inline const T& + as() const + { + return reinterpret_cast(buffer); + } + + /// A buffer large enough to store any of the semantic values. + char buffer[S]; + }; +]])[ ]b4_namespace_close[ #include "location.hh" @@ -99,16 +213,23 @@ do { \ 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 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 @@ -130,6 +251,7 @@ b4_user_stype /// \returns 0 iff parsing succeeded. virtual int parse (); +#if YYDEBUG /// The current debugging stream. std::ostream& debug_stream () const; /// Set the current debugging stream. @@ -141,6 +263,7 @@ b4_user_stype debug_level_type debug_level () const; /// Set the current debugging level. void set_debug_level (debug_level_type l); +#endif private: /// Report a syntax error. @@ -298,7 +421,7 @@ b4_percent_code_get([[provides]])[]dnl ])dnl @output(b4_parser_file_name@) b4_copyright([Skeleton implementation for Bison LALR(1) parsers in C++], - [2002, 2003, 2004, 2005, 2006]) + [2002, 2003, 2004, 2005, 2006, 2007, 2008]) b4_percent_code_get([[top]])[]dnl m4_if(b4_prefix, [yy], [], [ @@ -629,7 +752,6 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[; /* Discard the token being shifted. */ yychar = yyempty_; - yysemantic_stack_.push (yylval); yylocation_stack_.push (yylloc); @@ -654,7 +776,11 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[; | 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. @@ -662,9 +788,9 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[; 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 slice (yylocation_stack_, yylen); @@ -674,14 +800,14 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[; switch (yyn) { ]b4_user_actions[ - default: break; + default: + break; } YY_SYMBOL_PRINT ("-> $$ =", yyr1_[yyn], &yyval, &yyloc); yypop_ (yylen); yylen = 0; YY_STACK_PRINT (); - yysemantic_stack_.push (yyval); yylocation_stack_.push (yyloc); @@ -792,7 +918,7 @@ b4_error_verbose_if([, yytoken])[)); /* Shift the error token. */ YY_SYMBOL_PRINT ("Shifting", yystos_[yyn], - &yysemantic_stack_[0], &yylocation_stack_[0]); + &yysemantic_stack_[0], &yylocation_stack_[0]); yystate = yyn; goto yynewstate; @@ -1054,7 +1180,7 @@ b4_error_verbose_if([, int tok])[) dnl @output(b4_dir_prefix[]stack.hh@) b4_copyright([Stack handling for Bison parsers in C++], - [2002, 2003, 2004, 2005, 2006])[ + [2002, 2003, 2004, 2005, 2006, 2007, 2008])[ #ifndef BISON_STACK_HH # define BISON_STACK_HH @@ -1149,5 +1275,6 @@ b4_copyright([Stack handling for Bison parsers in C++], }; ]b4_namespace_close[ -#endif // not BISON_STACK_HH] +#endif // not BISON_STACK_HH[]dnl +] m4_divert_pop(0)