Currently each time we meet %merge we record this location as the
defining location (and symbol). Instead, record the first definition.
In the generated code we go from
yy0->A = merge (*yy0, *yy1);
to
yy0->S = merge (*yy0, *yy1);
where S was indeed the first symbol, and in the diagnostics we go from
glr-regr18.y:30.18-24: error: result type clash on merge function 'merge': <type2> != <type1>
30 | sym2: sym3 %merge<merge> { $$ = $1; } ;
| ^~~~~~~
glr-regr18.y:29.18-24: note: previous declaration
29 | sym1: sym2 %merge<merge> { $$ = $1; } ;
| ^~~~~~~
glr-regr18.y:31.13-19: error: result type clash on merge function 'merge': <type3> != <type2>
31 | sym3: %merge<merge> { $$ = 0; } ;
| ^~~~~~~
glr-regr18.y:30.18-24: note: previous declaration
30 | sym2: sym3 %merge<merge> { $$ = $1; } ;
| ^~~~~~~
to
glr-regr18.y:30.18-24: error: result type clash on merge function 'merge': <type2> != <type1>
30 | sym2: sym3 %merge<merge> { $$ = $1; } ;
| ^~~~~~~
glr-regr18.y:29.18-24: note: previous declaration
29 | sym1: sym2 %merge<merge> { $$ = $1; } ;
| ^~~~~~~
glr-regr18.y:31.13-19: error: result type clash on merge function 'merge': <type3> != <type1>
31 | sym3: %merge<merge> { $$ = 0; } ;
| ^~~~~~~
glr-regr18.y:29.18-24: note: previous declaration
29 | sym1: sym2 %merge<merge> { $$ = $1; } ;
| ^~~~~~~
where both duplicates are reported against definition 1, rather than
using definition 1 as a reference when diagnosing about definition 2,
and then 2 as a reference for 3.
* src/reader.c (record_merge_function_type): Keep the first definition.
* tests/glr-regression.at: Adjust.
Reported by Jot Dot.
https://lists.gnu.org/r/help-bison/2020-12/msg00014.html
* data/skeletons/glr.c, data/skeletons/glr2.cc (b4_call_merger): Use
the symbol's slot, not its type.
* examples/c/glr/c++-types.y: Use explicit per-symbol typing together
with api.value.type=union.
(yylex): Use yytoken_kind_t.
Don't generate C code from bison, leave that to the skeletons.
* src/output.c (merger_output): Emit invocations to b4_call_merger.
* data/skeletons/glr.c (b4_call_merger): New.
Symbols are richer than types, and in M4 it is my simpler (and more
common) to deal with symbols rather than types. So let's associate
mergers to a symbol rather than a type name.
* src/reader.h (merger_list): Replace the 'type' member by a symbol
member.
* src/reader.c (record_merge_function_type): Take a symbol as
argument, rather than a type name.
* src/output.c (merger_output): Adjust.
This macro is not exposed to users, make start it with 'YY_'.
* data/skeletons/bison.m4, data/skeletons/c.m4, data/skeletons/glr.c,
* data/skeletons/glr.cc, data/skeletons/lalr1.cc,
* src/parse-gram.c, tests/actions.at, tests/c++.at, tests/headers.at,
* tests/local.at (YYUSE): Rename as...
(YY_USE): this.
When comparing traces from different machines, the mixture of
stdout/stderr in the output are making things uselessly difficult.
* src/lssi.c, src/state-item.c: Output debug traces on stderr.
When using glr.cc, the C function yyparse is an internal detail that
should not be exposed. Users might call it by accident (I did).
* data/skeletons/glr.c (yyparse): When used for glr.cc, rename as yy_parse_impl.
* data/skeletons/glr.cc: Adjust.
The yydefgoto table uses -1 as an invalid for an impossible case (we
never use yydefgoto[0], since it corresponds to the reduction to
$accept, which never happens). Since yydefgoto is a table of state
numbers, this -1 forces a signed type uselessly, which (1) might
trigger compiler warnings when storing a value from yydefgoto into a
state number (nonnegative), and (2) wastes bits which might result in
using a int16 where a uint8 suffices.
Reported by Jot Dot <jotdot@shaw.ca>.
https://lists.gnu.org/r/bug-bison/2020-11/msg00027.html
* src/tables.c (default_goto): Use 0 rather than -1 as invalid value.
* tests/regression.at: Adjust.
* data/skeletons/lalr1.d (YYLocation.step): New.
* examples/d/calc/calc.y (Lexer): Reduce scopes to avoid uninitialized
varibles.
Factor the handling of locations.
We don't need lenChars.
Suggested by Joe Nelson <joe@begriffs.com>.
https://lists.gnu.org/r/help-bison/2020-12/msg00020.html
* data/skeletons/glr.c, data/skeletons/yacc.c (YYNOMEM): New.
Use it.
(yyexhaustedlab): Rename as...
(yynomemlab): this.
* tests/calc.at: Check it.
* doc/bison.texi: Document it.
Fix incorrect statements about non-existing constants for YYERROR etc.
There are some tests that cover them, but nothing for all the
skeletons. Let's do that in the calculator tests.
* tests/calc.at: Check YYACCEPT and YYABORT.
I am not aware of people subclassing the parser class, and I fail to
see how this could be useful. Rather than leaving a badly baked
feature (as in glr.cc currently), let's not support it at all, until
someone comes and explains why and how it would be useful.
* data/skeletons/glr2.cc (parser): We need no virtual function members.
It's on purpose that I keep the `this->` now. We'll see later if we
want to remove them.
* data/skeletons/glr2.cc (yygetToken): Move into...
(glr_stack::yyget_token): this.
(b4_lex): Adjust.
Currently we have two classes that actually should be fused together:
parser and glr_stack. Both carry part of the parsing: (i) parser
contains `parse`, which is the top-level of the parsing process, it
uses yygetToken, etc., and (ii) glr_stack takes care of all the
details (dealing with the stack), and also calls yygetToken.
However if we fuse them together, we would get a large parser class,
in the header file. So it is probably better to split this large
class using the pimpl idiom. But then it appears that glr_stack is
very close from being the impl of parser.
Let's improve this.
For a start...
* data/skeletons/glr2.cc (parser::parse): Move to...
(glr_stack::parse): here.
(parser::parse): Use it.
When comparing traces from different machines, the mixture of
stdout/stderr in the output are making things uselessly difficult.
* src/lssi.c, src/state-item.c: Output debug traces on stderr.
* data/skeletons/glr2.cc: We no longer play dirty tricks with
parse-params, remove the now useless dance around them.
We now have genuine objects for locations, leave the initial action
alone.
