There are many macros that are defined and used just
once (b4_public_if, b4_abstract_if, etc.). That's overkill. Rather,
let's define a macro to build the "public class YYParser" line.
It appears that the same syntax with "extends", "abstract", etc. is
implemented in the D parser, which looks very fishy...
* data/skeletons/d.m4, data/skeletons/java.m4 (b4_public_if)
(b4_abstract_if, b4_final_if, b4_strictfp_if): Replace with
(b4_parser_class_declaration): this.
* data/skeletons/lalr1.d, data/skeletons/lalr1.java: Adjust.
Commit 90a8537e62 was right, but issued
two error messages. Commit 80ef7e7639
tried to address that by mapping yychar and yytoken to empty, but that
completely breaks the invariants of glr.c. In particular, yygetToken
can be called repeatedly and is expected to return the latest result,
unless yytoken is YYEMPTY. Since the previous attempt was "recording"
that the token was coming from an exception by setting it to YYEMPTY,
instead of getting again the faulty token, we fetched another one.
Rather, revert to the first approach: map yytoken to "invalid token",
but record in yychar the fact that we come from an exception thrown in
the scanner.
* data/skeletons/glr.c (YYFAULTYTOK): New.
(yygetToken): Use it to record syntax errors from the scanner.
* tests/c++.at (Syntax error as exception): In addition to checking
syntax_error with error recovery, make sure it also behaves as
expected without.
The previous name was historical and inconsistent.
* src/muscle-tab.c (define_directive): Use the proper value passing
syntax, based on the muscle kind.
(muscle_percent_variable_update): Use the right value passing syntax.
Migrate from parser_class_name to api.parser.class.
* data/skeletons: Migrate from parser_class_name to api.parser.class.
* doc/bison.texi (%define Summary): Document both parser_class_name
and api.parser.class.
Promote the latter over the former.
This is very debatable. This function is not pure at all, so it could
stick to returning void: that's a common coding style to tell the
difference between "real" (pure) functions and side-effecting
subroutines. However, we already have this style elsewhere (e.g.,
yylex), and I feel the callers are somewhat nice to read this way.
* data/skeletons/glr.c (yygetLRActions): Return the action rather than
passing by pointer.
While at it, fix type of yytoken.
Adjust callers.
Reported by Askar Safin.
https://lists.gnu.org/archive/html/bison-patches/2019-01/msg00000.html
* data/skeletons/glr.c (yygetToken): Return YYEMPTY when an exception
is thrown.
* data/skeletons/lalr1.cc: Log when an exception is caught.
* tests/c++.at (Syntax error as exception): Be sure to recover from
error before triggering another error.
This way, it is easier to make sure its implementation is available in
glr.cc too, which is not the case currently.
* data/skeletons/c++.m4 (b4_public_types_define): Move the
implementation of syntax_error...
(b4_public_types_declare): here.
We used to create a short definition of yy::parser with all the
implementations of its member functions outside. But yy::parser is no
longer short and simple to read. Maintaining each function twice is
painful: a lot of redundancy but different indentation levels, output
which depends on whether we are in a header or not (see
d132c2d545), etc.
Let's simplify this and put the implementations into the class
definition itself.
Discussed in this monologue:
https://lists.gnu.org/archive/html/bison-patches/2018-12/msg00058.html.
* data/skeletons/c++.m4, data/skeletons/lalr1.cc,
* data/skeletons/variant.hh (b4_basic_symbol_constructor_define)
(_b4_token_constructor_declare, b4_token_constructor_declare)
Merge into...
(b4_basic_symbol_constructor_define, _b4_token_constructor_define)
(b4_token_constructor_define): these.
We used to define such auxiliary structures outside the class, mainly
as a matter of style to keep the definition of yy::parser short and
simple. However, now there's a lot more code generated inside the
class definition (e.g., all the token constructors), so the
readability no longer applies.
However, if we move stack (and slice) inside yy::parser, then it
should no longer be needed to change the namespace to have multiple
parsers: changing the class name should suffice.
One common argument against inner classes is that they code bloat. It
hardly applies here, since typically different parsers will have
different semantic value types, hence different actual stack types.
* data/skeletons/lalr1.cc: Invoke b4_stack_define inside yy::parser.
