X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/b9e4eb5b7288c5cdf35f26d74786a3aacf56e137..6656c9b52a306b394fb6529f735924db0f08c1a2:/data/variant.hh?ds=sidebyside diff --git a/data/variant.hh b/data/variant.hh index 1534b903..41286c5b 100644 --- a/data/variant.hh +++ b/data/variant.hh @@ -1,7 +1,6 @@ # C++ skeleton for Bison -# Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008 -# Free Software Foundation, Inc. +# Copyright (C) 2002-2012 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 @@ -52,13 +51,6 @@ m4_define([_b4_char_sizeof_dummy], 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: @@ -70,40 +62,55 @@ m4_define([b4_char_sizeof_], m4_define([b4_char_sizeof], [b4_symbol_if([$1], [has_type], [ -m4_map([b4_char_sizeof_], [$@])dnl +m4_map([ b4_symbol_tag_comment], [$@])dnl char _b4_char_sizeof_dummy@{sizeof([b4_symbol([$1], [type])])@}; ])]) -# b4_variant_definition -# --------------------- +# b4_variant_includes +# ------------------- +# The needed includes for variants support. +m4_define([b4_variant_includes], +[b4_parse_assert_if([[#include ]])[ +#include // abort +#ifndef YYASSERT +# include +# define YYASSERT assert +#endif +]]) + +# b4_variant_define +# ----------------- # Define "variant". -m4_define([b4_variant_definition], -[[ - /// A char[S] buffer to store and retrieve objects. +m4_define([b4_variant_define], +[[ /// 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 - {]b4_assert_if([ - /// Whether something is contained. - bool built; -])[ + { + /// Type of *this. + typedef variant self_type; + /// Empty construction. inline - variant ()]b4_assert_if([ - : built (false)])[ + variant ()]b4_parse_assert_if([ + : built (false) + , tname (YY_NULL)])[ {} /// Instantiate a \a T in here. template inline T& build () - {]b4_assert_if([ - assert (!built); - built = true;])[ + {]b4_parse_assert_if([ + //YYASSERT (!built); + //YYASSERT (!tname); + YYASSERT (sizeof (T) <= S); + built = true; + tname = typeid (T).name ();])[ return *new (buffer.raw) T; } @@ -111,44 +118,62 @@ m4_define([b4_variant_definition], template inline T& build (const T& t) - {]b4_assert_if([ - assert(!built); - built = true;])[ - return *new (buffer.raw) T(t); + {]b4_parse_assert_if([ + //YYASSERT (!built); + //YYASSERT (!tname); + YYASSERT (sizeof (T) <= S); + built = true; + tname = typeid (T).name ();])[ + return *new (buffer.raw) T (t); } /// Construct and fill. template inline - variant (const T& t)]b4_assert_if([ - : built (true)])[ + variant (const T& t)]b4_parse_assert_if([ + : built (true) + , tname (typeid (T).name ())])[ { - new (buffer.raw) T(t); + YYASSERT (sizeof (T) <= S); + new (buffer.raw) T (t); } /// Accessor to a built \a T. template inline T& as () - {]b4_assert_if([ - assert (built);])[ - return reinterpret_cast(buffer.raw); + {]b4_parse_assert_if([ + YYASSERT (built); + YYASSERT (tname == typeid (T).name ()); + YYASSERT (sizeof (T) <= S);])[ + return reinterpret_cast (buffer.raw); } /// Const accessor to a built \a T (for %printer). template inline const T& as () const - {]b4_assert_if([ - assert(built);])[ - return reinterpret_cast(buffer.raw); + {]b4_parse_assert_if([ + YYASSERT (built); + YYASSERT (tname == typeid (T).name ()); + YYASSERT (sizeof (T) <= S);])[ + return reinterpret_cast (buffer.raw); } - /// Swap the content with \a other. + /// Swap the content with \a other, of same type. + /// Both variants must be built beforehand, because swapping the actual + /// data requires reading it (with as()), and this is not possible on + /// unconstructed variants: it would require some dynamic testing, which + /// should not be the variant's responsability. + /// Swapping between built and ((possibly) non-built is done with + /// variant::move (). template inline void swap (variant& other) - { + {]b4_parse_assert_if([ + YYASSERT (built); + YYASSERT (other.built); + YYASSERT (tname == other.tname);])[ std::swap (as(), other.as()); } @@ -156,22 +181,46 @@ m4_define([b4_variant_definition], /// Destroys \a other. template inline void - build (variant& other) - { + move (variant& other) + {]b4_parse_assert_if([ + YYASSERT (! built);])[ build(); swap(other); other.destroy(); } + /// Copy the content of \a other to this. + /// Destroys \a other. + template + inline void + copy (const variant& other) + { + build (other.as ()); + } + /// Destroy the stored \a T. template inline void destroy () { - as().~T();]b4_assert_if([ - built = false;])[ + as ().~T ();]b4_parse_assert_if([ + built = false; + tname = YY_NULL;])[ } + /// Prohibit blind copies. + private: + self_type& operator=(const self_type&) + { + abort (); + } + + variant (const self_type&) + { + abort (); + } + + private: /// A buffer large enough to store any of the semantic values. /// Long double is chosen as it has the strongest alignment /// constraints. @@ -179,7 +228,11 @@ m4_define([b4_variant_definition], { long double align_me; char raw[S]; - } buffer; + } buffer;]b4_parse_assert_if([ + /// Whether something is contained. + bool built; + /// If defined, the name of the stored type. + const char* tname;])[ }; ]]) @@ -198,7 +251,8 @@ m4_define([b4_semantic_type_declare], {]b4_type_foreach([b4_char_sizeof])[}; /// Symbol semantic values. - typedef variant semantic_type;]) + typedef variant semantic_type;dnl +]) # How the semantic value is extracted when using variants. @@ -217,3 +271,62 @@ m4_define([b4_symbol_value_template], [m4_ifval([$2], [$1.template as< $2 >()], [$1])]) + + + +## ------------- ## +## make_SYMBOL. ## +## ------------- ## + + +# b4_symbol_constructor_declare_(SYMBOL-NUMBER) +# --------------------------------------------- +# Declare the overloaded version of make_symbol for the (common) type of +# these SYMBOL-NUMBERS. Use at class-level. +m4_define([b4_symbol_constructor_declare_], +[b4_symbol_if([$1], [is_token], [b4_symbol_if([$1], [has_id], +[ static inline + symbol_type + make_[]b4_symbol_([$1], [id]) (dnl +b4_join(b4_symbol_if([$1], [has_type], + [const b4_symbol([$1], [type])& v]), + b4_locations_if([const location_type& l]))); + +])])]) + + +# b4_symbol_constructor_declare +# ----------------------------- +# Declare symbol constructors for all the value types. +# Use at class-level. +m4_define([b4_symbol_constructor_declare], +[ // Symbol constructors declarations. +b4_symbol_foreach([b4_symbol_constructor_declare_])]) + + + +# b4_symbol_constructor_define_(SYMBOL-NUMBER) +# -------------------------------------------- +# Define symbol constructor for this SYMBOL-NUMBER. +m4_define([b4_symbol_constructor_define_], +[b4_symbol_if([$1], [is_token], [b4_symbol_if([$1], [has_id], +[ b4_parser_class_name::symbol_type + b4_parser_class_name::make_[]b4_symbol_([$1], [id]) (dnl +b4_join(b4_symbol_if([$1], [has_type], + [const b4_symbol([$1], [type])& v]), + b4_locations_if([const location_type& l]))) + { + return symbol_type (b4_join([token::b4_symbol([$1], [id])], + b4_symbol_if([$1], [has_type], [v]), + b4_locations_if([l]))); + } + +])])]) + + +# b4_symbol_constructor_define +# ---------------------------- +# Define the overloaded versions of make_symbol for all the value types. +m4_define([b4_symbol_constructor_define], +[ // Implementation of make_symbol for each symbol type. +b4_symbol_foreach([b4_symbol_constructor_define_])])