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c++: give public access to the symbol kind

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symbol_type::token () was removed: it returned the token kind of a
symbol.  To do that, one needs to convert from the symbol kind to the
token kind, which requires a table.

This broke some users' unit tests for scanners, see
https://lists.gnu.org/r/bug-bison/2020-01/msg00001.html
https://lists.gnu.org/r/bug-bison/2020-03/msg00020.html
https://lists.gnu.org/r/help-bison/2020-04/msg00005.html

Instead of making this possible again, let's check the symbol's kind
instead.  So give proper access to a symbol's kind.

That feature existed, undocumented, as 'type_get()'.  Let's rename
this as 'kind()'.

* data/skeletons/c++.m4, data/skeletons/glr.cc,
* data/skeletons/lalr1.cc (type_get): Rename as...
(kind): This.
(type_get): Install a backward compatibility alias.
* doc/bison.texi (Complete Symbols): Document symbol_type and
symbol_type::kind.
This commit is contained in:
Akim Demaille
2020-04-17 08:51:18 +02:00
parent e86b14069d
commit d6ae95fb50
6 changed files with 67 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
NEWS
View File

@@ -73,8 +73,8 @@ GNU Bison NEWS
**** Token aliases internationalization
When the %define variable parse.error is set to `custom` or `detailed`,
one may use the _() annotation to specify which token aliases are to be
translated. For instance
one may specify which token aliases are to be translated using _(). For
instance
%token
PLUS "+"
@@ -163,6 +163,18 @@ GNU Bison NEWS
Contributed by Victor Morales Cayuela.
*** C++
The token and symbol kinds are yy::parser::token_kind_type and
yy::parser::symbol_kind_type.
The symbol_type::kind() member function allows to get the kind of a
symbol. This can be used to write unit tests for scanners, e.g.,
yy::parser::symbol_type t = make_NUMBER ("123");
assert (t.kind () == yy::parser::symbol_kind::S_NUMBER);
assert (t.value.as<int> () == 123);
** Documentation
*** User Manual

1
TODO
View File

@@ -16,7 +16,6 @@
** Documentation
- YYERRCODE, YYUNDEF, YYEOF
- symbol.type_get should be kind_get, and it's not documented.
- YYERRCODE and translation
** Java

36
data/skeletons/c++.m4
View File

@@ -290,8 +290,8 @@ m4_define([b4_public_types_declare],
m4_define([b4_symbol_type_define],
[[ /// A complete symbol.
///
/// Expects its Base type to provide access to the symbol type
/// via type_get ().
/// Expects its Base type to provide access to the symbol kind
/// via kind ().
///
/// Provide access to semantic value]b4_locations_if([ and location])[.
template <typename Base>
@@ -313,7 +313,7 @@ m4_define([b4_symbol_type_define],
, value (]b4_variant_if([], [std::move (that.value)]))b4_locations_if([
, location (std::move (that.location))])[
{]b4_variant_if([
b4_symbol_variant([this->type_get ()], [value], [move],
b4_symbol_variant([this->kind ()], [value], [move],
[std::move (that.value)])
])[}
#endif
@@ -342,7 +342,7 @@ m4_define([b4_symbol_type_define],
void clear ()
{]b4_variant_if([[
// User destructor.
symbol_kind_type yykind = this->type_get ();
symbol_kind_type yykind = this->kind ();
basic_symbol<Base>& yysym = *this;
(void) yysym;
switch (yykind)
@@ -357,6 +357,9 @@ m4_define([b4_symbol_type_define],
Base::clear ();
}
/// Backward compatibility.
symbol_kind_type type_get () const YY_NOEXCEPT;
/// Whether empty.
bool empty () const YY_NOEXCEPT;
@@ -390,7 +393,7 @@ m4_define([b4_symbol_type_define],
/// Copy constructor.
by_type (const by_type& that);
/// The symbol type as needed by the constructor.
/// The symbol kind as needed by the constructor.
typedef token_kind_type kind_type;
/// Constructor from (external) token numbers.
@@ -399,14 +402,14 @@ m4_define([b4_symbol_type_define],
/// Record that this symbol is empty.
void clear ();
/// Steal the symbol type from \a that.
/// Steal the symbol kind from \a that.
void move (by_type& that);
/// The (internal) type number (corresponding to \a type).
/// \a empty when empty.
symbol_kind_type type_get () const YY_NOEXCEPT;
symbol_kind_type kind () const YY_NOEXCEPT;
/// The symbol type.
/// The symbol kind.
/// \a ]b4_symbol_prefix[YYEMPTY when empty.
symbol_kind_type type;
};
@@ -437,7 +440,7 @@ m4_define([b4_public_types_define],
, value (]b4_variant_if([], [that.value]))b4_locations_if([
, location (that.location)])[
{]b4_variant_if([
b4_symbol_variant([this->type_get ()], [value], [copy],
b4_symbol_variant([this->kind ()], [value], [copy],
[YY_MOVE (that.value)])
])[}
@@ -462,13 +465,20 @@ m4_define([b4_public_types_define],
, location (YY_MOVE (l))])[
{]b4_variant_if([[
(void) v;
]b4_symbol_variant([this->type_get ()], [value], [YY_MOVE_OR_COPY], [YY_MOVE (v)])])[}]])[
]b4_symbol_variant([this->kind ()], [value], [YY_MOVE_OR_COPY], [YY_MOVE (v)])])[}]])[
template <typename Base>
]b4_parser_class[::symbol_kind_type
]b4_parser_class[::basic_symbol<Base>::type_get () const YY_NOEXCEPT
{
return this->kind ();
}
template <typename Base>
bool
]b4_parser_class[::basic_symbol<Base>::empty () const YY_NOEXCEPT
{
return Base::type_get () == symbol_kind::]b4_symbol_prefix[YYEMPTY;
return this->kind () == symbol_kind::]b4_symbol_prefix[YYEMPTY;
}
template <typename Base>
@@ -476,7 +486,7 @@ m4_define([b4_public_types_define],
]b4_parser_class[::basic_symbol<Base>::move (basic_symbol& s)
{
super_type::move (s);
]b4_variant_if([b4_symbol_variant([this->type_get ()], [value], [move],
]b4_variant_if([b4_symbol_variant([this->kind ()], [value], [move],
[YY_MOVE (s.value)])],
[value = YY_MOVE (s.value);])[]b4_locations_if([
location = YY_MOVE (s.location);])[
@@ -517,7 +527,7 @@ m4_define([b4_public_types_define],
}
]b4_inline([$1])[]b4_parser_class[::symbol_kind_type
]b4_parser_class[::by_type::type_get () const YY_NOEXCEPT
]b4_parser_class[::by_type::kind () const YY_NOEXCEPT
{
return type;
}

2
data/skeletons/glr.cc
View File

@@ -107,7 +107,7 @@ yyerror (]b4_locations_if([[const ]b4_namespace_ref::b4_parser_class[::location_
]b4_percent_define_flag_if([[global_tokens_and_yystype]], [],
[m4_define([b4_pre_epilogue],
[[/* The user is using the C++ token type, not the C one. */
[[/* The user is using the C++ token kind, not the C one. */
#undef ]b4_symbol(0, [id])
])])[

36
data/skeletons/lalr1.cc
View File

@@ -241,7 +241,7 @@ m4_define([b4_shared_declarations],
public:
context (const ]b4_parser_class[& yyparser, const symbol_type& yyla);
const symbol_type& lookahead () const { return yyla_; }
symbol_kind_type token () const { return yyla_.type_get (); }]b4_locations_if([[
symbol_kind_type token () const { return yyla_.kind (); }]b4_locations_if([[
const location_type& location () const { return yyla_.location; }
]])[
/// Put in YYARG at most YYARGN of the expected tokens, and return the
@@ -340,7 +340,7 @@ m4_define([b4_shared_declarations],
/// Debug stream.
std::ostream* yycdebug_;
/// \brief Display a symbol type, value and location.
/// \brief Display a symbol kind, value and location.
/// \param yyo The output stream.
/// \param yysym The symbol.
template <typename Base>
@@ -373,12 +373,12 @@ m4_define([b4_shared_declarations],
/// Record that this symbol is empty.
void clear () YY_NOEXCEPT;
/// Steal the symbol type from \a that.
/// Steal the symbol kind from \a that.
void move (by_state& that);
/// The symbol kind (corresponding to \a state).
/// \a ]b4_symbol(-2, kind)[ when empty.
symbol_kind_type type_get () const YY_NOEXCEPT;
symbol_kind_type kind () const YY_NOEXCEPT;
/// The state number used to denote an empty symbol.
/// We use the initial state, as it does not have a value.
@@ -665,7 +665,7 @@ b4_parse_error_case([verbose], [[
{}
/*---------------.
| Symbol types. |
| symbol kinds. |
`---------------*/
]b4_token_ctor_if([], [b4_public_types_define([cc])])[
@@ -697,7 +697,7 @@ b4_parse_error_case([verbose], [[
{}
]b4_parser_class[::symbol_kind_type
]b4_parser_class[::by_state::type_get () const YY_NOEXCEPT
]b4_parser_class[::by_state::kind () const YY_NOEXCEPT
{
if (state == empty_state)
return symbol_kind::]b4_symbol(-2, kind)[;
@@ -711,7 +711,7 @@ b4_parse_error_case([verbose], [[
]b4_parser_class[::stack_symbol_type::stack_symbol_type (YY_RVREF (stack_symbol_type) that)
: super_type (YY_MOVE (that.state)]b4_variant_if([], [, YY_MOVE (that.value)])b4_locations_if([, YY_MOVE (that.location)])[)
{]b4_variant_if([
b4_symbol_variant([that.type_get ()],
b4_symbol_variant([that.kind ()],
[value], [YY_MOVE_OR_COPY], [YY_MOVE (that.value)])])[
#if 201103L <= YY_CPLUSPLUS
// that is emptied.
@@ -722,7 +722,7 @@ b4_parse_error_case([verbose], [[
]b4_parser_class[::stack_symbol_type::stack_symbol_type (state_type s, YY_MOVE_REF (symbol_type) that)
: super_type (s]b4_variant_if([], [, YY_MOVE (that.value)])[]b4_locations_if([, YY_MOVE (that.location)])[)
{]b4_variant_if([
b4_symbol_variant([that.type_get ()],
b4_symbol_variant([that.kind ()],
[value], [move], [YY_MOVE (that.value)])])[
// that is emptied.
that.type = symbol_kind::]b4_symbol(-2, kind)[;
@@ -733,7 +733,7 @@ b4_parse_error_case([verbose], [[
]b4_parser_class[::stack_symbol_type::operator= (const stack_symbol_type& that)
{
state = that.state;
]b4_variant_if([b4_symbol_variant([that.type_get ()],
]b4_variant_if([b4_symbol_variant([that.kind ()],
[value], [copy], [that.value])],
[[value = that.value;]])[]b4_locations_if([
location = that.location;])[
@@ -744,7 +744,7 @@ b4_parse_error_case([verbose], [[
]b4_parser_class[::stack_symbol_type::operator= (stack_symbol_type& that)
{
state = that.state;
]b4_variant_if([b4_symbol_variant([that.type_get ()],
]b4_variant_if([b4_symbol_variant([that.kind ()],
[value], [move], [that.value])],
[[value = that.value;]])[]b4_locations_if([
location = that.location;])[
@@ -762,7 +762,7 @@ b4_parse_error_case([verbose], [[
YY_SYMBOL_PRINT (yymsg, yysym);]b4_variant_if([], [
// User destructor.
b4_symbol_actions([destructor], [yysym.type_get ()])])[
b4_symbol_actions([destructor], [yysym.kind ()])])[
}
#if ]b4_api_PREFIX[DEBUG
@@ -773,7 +773,7 @@ b4_parse_error_case([verbose], [[
{
std::ostream& yyoutput = yyo;
YYUSE (yyoutput);
symbol_kind_type yykind = yysym.type_get ();
symbol_kind_type yykind = yysym.kind ();
#if defined __GNUC__ && ! defined __clang__ && ! defined __ICC && __GNUC__ * 100 + __GNUC_MINOR__ <= 408
// Avoid a (spurious) G++ 4.8 warning about "array subscript is
// below array bounds".
@@ -958,10 +958,10 @@ b4_dollar_popdef])[]dnl
/* If the proper action on seeing token YYLA.TYPE is to reduce or
to detect an error, take that action. */
yyn += yyla.type_get ();
if (yyn < 0 || yylast_ < yyn || yycheck_[yyn] != yyla.type_get ())
yyn += yyla.kind ();
if (yyn < 0 || yylast_ < yyn || yycheck_[yyn] != yyla.kind ())
{]b4_lac_if([[
if (!yy_lac_establish_ (yyla.type_get ()))
if (!yy_lac_establish_ (yyla.kind ()))
goto yyerrlab;]])[
goto yydefault;
}
@@ -972,7 +972,7 @@ b4_dollar_popdef])[]dnl
{
if (yy_table_value_is_error_ (yyn))
goto yyerrlab;]b4_lac_if([[
if (!yy_lac_establish_ (yyla.type_get ()))
if (!yy_lac_establish_ (yyla.kind ()))
goto yyerrlab;
]])[
yyn = -yyn;
@@ -1089,7 +1089,7 @@ b4_dollar_popdef])[]dnl
error, discard it. */
// Return failure if at end of input.
if (yyla.type_get () == symbol_kind::]b4_symbol_prefix[YYEOF)
if (yyla.kind () == symbol_kind::]b4_symbol_prefix[YYEOF)
YYABORT;
else if (!yyla.empty ())
{
@@ -1240,7 +1240,7 @@ b4_dollar_popdef])[]dnl
// Execute LAC once. We don't care if it is successful, we
// only do it for the sake of debugging output.
if (!yyparser_.yy_lac_established_)
yyparser_.yy_lac_check_ (yyla_.type_get ());
yyparser_.yy_lac_check_ (yyla_.kind ());
#endif
for (int yyx = 0; yyx < YYNTOKENS; ++yyx)

11
doc/bison.texi
View File

@@ -12193,6 +12193,17 @@ location. Invocations of @samp{%lex-param @{@var{type1} @var{arg1}@}} yield
additional arguments.
@end deftypefun
@defcv {Type} {parser} {symbol_type}
A ``complete symbol'', that binds together its kind, value and (when
applicable) location.
@end defcv
@deftypemethod {symbol_type} {symbol_kind_type} kind () @code{const}
The kind of this symbol.
@end deftypemethod
@sp 1
For each token kind, Bison generates named constructors as follows.
@deftypeop {Constructor} {parser::symbol_type} {} {symbol_type} (@code{int} @var{token}, @code{const @var{value_type}&} @var{value}, @code{const location_type&} @var{location})