The implementation of yy::parser::symbol_name is emitted even before
the implementation of yy::parser::parser. This makes little sense.
* data/skeletons/lalr1.cc (symbol_name): Move its implementation in
the same place as in the class definition: after "error" and before
"context".
Reported by Martin Blais <blais@furius.ca>.
https://lists.gnu.org/r/help-bison/2020-05/msg00005.html
* data/skeletons/lalr1.cc (symbol_name): Make it public.
Add a private hidden hook to enable testing of private parts.
* tests/local.at (AT_DATA_GRAMMAR_PROLOGUE): Help Emacs find the right
language mode.
* tests/c++.at (C++ Variant-based Symbols Unit Tests): Check that we
can read symbol_name.
The user gives yyexpected_tokens a limit: the max number of tokens she
wants to hear about. That's because an error message that reports a
bazillion of possible tokens is useless.
In that case yyexpected_tokens returned 0, so the user would not know
if there are too many expected tokens or none (yes, that's possible).
There are several ways to tell the user in which situation she's in:
- return some E2MANY, a negative value. Then it makes the pattern
int argsize = yypcontext_expected_tokens (ctx, arg, ARGS_MAX);
if (argsize < 0)
return argsize;
no longer valid, as for E2MANY (i) the user must generate the error
message anyway, and (ii) she should not return E2MANY
- return ARGS_MAX + 1. Then it makes it dangerous for the user, as
she has to iterate update `min (ARGS_MAX, argsize)`.
Returning 0 is definitely simpler and safer for the user, as it tells
her "this is not an error, just generate your message without a list
of expecting tokens". So let's still return 0, but set arg[0] to the
empty token when the list is really empty.
* data/skeletons/glr.c, data/skeletons/lalr1.cc, data/skeletons/lalr1.java
* data/skeletons/yacc.c (yyexpected_tokens): Put the empty symbol
first if there are no possible tokens at all.
* examples/c/bistromathic/parse.y: Demonstrate how to use that.
For instance test 386, "glr.cc api.value.type={double}":
types.at:366: $CXX $CXXFLAGS $CPPFLAGS $LDFLAGS -o test test.cc $LIBS
stderr:
test.cc: In function 'ptrdiff_t yysplitStack(yyGLRStack*, ptrdiff_t)':
test.cc:490:4: error: 'PTRDIFF_MAX' was not declared in this scope
(PTRDIFF_MAX < SIZE_MAX ? PTRDIFF_MAX : YY_CAST (ptrdiff_t, SIZE_MAX))
^
test.cc:1805:37: note: in expansion of macro 'YYSIZEMAX'
ptrdiff_t half_max_capacity = YYSIZEMAX / 2 / state_size;
^~~~~~~~~
test.cc:490:4: note: suggested alternative: '__PTRDIFF_MAX__'
(PTRDIFF_MAX < SIZE_MAX ? PTRDIFF_MAX : YY_CAST (ptrdiff_t, SIZE_MAX))
^
test.cc:1805:37: note: in expansion of macro 'YYSIZEMAX'
ptrdiff_t half_max_capacity = YYSIZEMAX / 2 / state_size;
^~~~~~~~~
The failing tests are using glr.cc only, which I don't understand, the
problem is rather in glr.c, so I would expect glr.c tests to also fail.
Reported by Bruno Haible.
https://lists.gnu.org/archive/html/bug-bison/2020-05/msg00053.html
* data/skeletons/yacc.c: Move the block that defines
YYPTRDIFF_T/YYPTRDIFF_MAXIMUM, YYSIZE_T/YYSIZE_MAXIMUM, and
YYSIZEOF to...
* data/skeletons/c.m4 (b4_sizes_types_define): Here.
(b4_c99_int_type): Also take care of the #undefinition of short.
* data/skeletons/yacc.c, data/skeletons/glr.c: Use
b4_sizes_types_define.
* data/skeletons/glr.c: Adjust to use YYPTRDIFF_T/YYPTRDIFF_MAXIMUM,
YYSIZE_T/YYSIZE_MAXIMUM.
* data/skeletons/lalr1.java (Location): Make it a static class.
(Lexer.yylex, Lexer.getLVal, Lexer.getStartPos, Lexer.getEndPos):
These are not needed in push parsers.
* examples/java/calc/Calc.y: Demonstrate push parsers in the Java.
* doc/bison.texi: Push parsers have been supported for a long time,
remove incorrect statements stating the opposite.
To write unit tests for their scanners, some users depended on
symbol_type::token():
Lexer lex("12345");
symbol_type t = lex.nextToken();
assert(t.token() == token::INTLIT);
assert(t.value.as<int>() == 12345);
But symbol_type::token() was removed in Bison 3.5 because it relied on
a conversion table. So users had to find other patterns, such as
assert(t.type_get() == by_type(token::INTLIT).type_get());
which relies on several private implementation details.
As part of transitioning from "token type" to "token kind", and making
this a public and documented interface, "by_type" was renamed
"by_kind" and "type_get()" was renamed as "kind()". The latter had
backward compatibility mechanisms, not the former.
In Bison 3.6 none of this should be used, but rather
assert(t.kind() == symbol_kind::S_INTLIT);
Reported by Pramod Kumbhar.
https://lists.gnu.org/r/bug-bison/2020-05/msg00012.html
* data/skeletons/c++.m4 (by_type): Make it an alias to by_kind.
I don't plan to fix everything in one go. But this was in the way of
the next commit.
* data/skeletons/lalr1.java: Avoid space before parens.
* tests/java.at: Adjust.
Some people have been using that symbol. Some even have #defined it
themselves.
https://lists.gnu.org/r/bison-patches/2020-04/msg00138.html
Let's provide backward compatibility, having it point to YYUNDEF, so
that an error message is generated.
* data/skeletons/yacc.c (YYERRCODE): New, at the exact same location
it was defined before.
These are internal details. `type_get ()` is still there to ensure
backward compatibility, `kind ()` being the modern way.
* data/skeletons/c++.m4 (by_type, by_type::type): Rename as...
(by_kind, by_kind::kind_): this.
Adjust dependencies.
From
public interface Lexer {
/* Token kinds. */
/** Token number, to be returned by the scanner. */
static final int YYEOF = 0;
/** Token number, to be returned by the scanner. */
static final int YYERRCODE = 256;
/** Token number, to be returned by the scanner. */
static final int YYUNDEF = 257;
/** Token number, to be returned by the scanner. */
static final int BANG = 258;
...
/** Deprecated, use b4_symbol(0, id) instead. */
public static final int EOF = YYEOF;
to
public interface Lexer {
/* Token kinds. */
/** Token "end of file", to be returned by the scanner. */
static final int YYEOF = 0;
/** Token error, to be returned by the scanner. */
static final int YYerror = 256;
/** Token "invalid token", to be returned by the scanner. */
static final int YYUNDEF = 257;
/** Token "!", to be returned by the scanner. */
static final int BANG = 258;
...
/** Deprecated, use YYEOF instead. */
public static final int EOF = YYEOF;
* data/skeletons/java.m4 (b4_token_enum): Display the symbol's tag in
comment.
* data/skeletons/lalr1.java: Address overquotation issue.
* examples/java/calc/Calc.y, examples/java/simple/Calc.y: Use YYEOF,
not EOF.
I'm quite pleased to see that the tricky case of glr.c was already
prepared by the changes to support syntax_error exceptions. Better
yet, it is actually syntax_error that becomes a special case of the
general pattern: make yytoken be YYERRCODE.
* data/skeletons/glr.c (YYFAULTYTOK): Remove the now useless (Basil)
Faulty token.
Instead, use the error token.
* data/skeletons/lalr1.d, data/skeletons/lalr1.java: When computing
the action, first check the case of the error token.
* tests/calc.at: Check cases for the error token symbols before and
after it.
* data/skeletons/yacc.c (yyparse): When the scanner returns YYERRCODE,
go directly to error recovery (yyerrlab1).
However, don't keep the error token as lookahead, that token is too
special.
* data/skeletons/lalr1.cc: Likewise.
* examples/c/bistromathic/parse.y (yylex): Use that feature to report
nicely invalid characters.
* examples/c/bistromathic/bistromathic.test: Check that.
* examples/test: Neutralize gratuitous differences such as rule
position.
* tests/calc.at: Check that case in C only.
The other case seem to be working, but that's an illusion that the
next commit will address (in fact, they can enter endless loops, and
report the error several times anyway).
We will not keep YYERRCODE anyway, it causes backward compatibility
issues. So as a first step, let all the skeletons use that name,
until we have a better one.
* data/skeletons/bison.m4, data/skeletons/glr.c,
* data/skeletons/glr.cc, data/skeletons/lalr1.cc,
* data/skeletons/lalr1.d, data/skeletons/lalr1.java,
* data/skeletons/yacc.c, doc/bison.texi, tests/headers.at,
* tests/input.at:
here.
We could try to avoid the weird "#if 1", but then the indentation of
the inner #if would be wrong. Let' keep it this way.
* data/skeletons/yacc.c: here.
Also, avoid sticking the comment to the directive.
In C/C++, N_ is a no-op. Define it if the user didn't.
Suggested by Frank Heckenbach.
https://lists.gnu.org/r/bug-bison/2020-04/msg00010.html
* src/output.c (prepare_symbol_names): Rename has_translations as
has_translations_flag.
* data/skeletons/bison.m4 (b4_has_translations_if): New.
* data/skeletons/java.m4 (b4_trans): Use it.
* data/skeletons/glr.c, data/skeletons/lalr1.cc, data/skeletons/yacc.c
(N_): Provide a default definition.
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.htmlhttps://lists.gnu.org/r/bug-bison/2020-03/msg00020.htmlhttps://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.
* data/skeletons/c++.m4: Define the old names in terms on the new
ones, instead of the converse.
* doc/bison.texi (C++ Parser Interface): Be more extensive about
token_kind_type.
Not all the symbols have a fixed symbol code. UNDEF's one is fixed:
-2.
* data/skeletons/glr.c, data/skeletons/lalr1.cc, data/skeletons/lalr1.d,
* data/skeletons/yacc.c: here.
Why didn't I think about this before??? symbolName should be a method
of SymbolKind.
* data/skeletons/lalr1.java (YYParser::yysymbolName): Move as...
* data/skeletons/java.m4 (SymbolKind::getName): this.
Make the table a static final table, not a local variable.
Adjust dependencies.
* doc/bison.texi (Java Parser Interface): Document i18n.
(Java Parser Context Interface): Document SymbolKind.
* examples/java/calc/Calc.y, tests/local.at: Adjust.
* doc/bison.texi (C++ Parser Context): New.
* data/skeletons/lalr1.cc (parser::yysymbol_name): Rename as...
(parser::symbol_name): this.
(A Complete C++ Example): Promote LAC, now that we have it.
Promote parse.error detailed over verbose.
* examples/c++/calc++/calc++.test, tests/local.at: Adjust.
I have been hesitating a lot before doing it ---after all the user
must not use this kind, so what's the point of showing it in
yytoken_kind_t. And eventually I chose to play it safe with the
typing system and make it possible to use yytoken_kind_t for all the
tokens, even the "empty token".
* data/skeletons/c.m4: Give an id and a tag to YYEMPTY.
(b4_token_enums): Define YYEMPTY.
* data/skeletons/c++.m4 (b4_token_enums): Define YYEMPTY.
* data/skeletons/glr.c, data/skeletons/glr.cc, data/skeletons/yacc.c:
(YYEMPTY): Remove.
Use b4_symbol(-2, id) instead.
The user should think of yypcontext fields as accessible only via
yypcontext_* functions. So let's rename yyexpected_tokens to reflect
that.
Let's _not_ rename yyreport_syntax_error, as the user may define this
function, and is not allowed to access directly the fields of
yypcontext_t: she *must* use the "accessors". This is comparable to
the case of C++/Java where the user defines
parser::report_syntax_error, not parser::context::report_syntax_error.
* data/skeletons/glr.c, data/skeletons/yacc.c (yyexpected_tokens):
Rename as...
(yypcontext_expected_tokens): this.
Adjust dependencies.
