Currently pstate_new does not set up its variables, this task is left
to yypush_parse. This was probably to share more code with usual pull
parsers, where these (local) variables are indeed initialized by
yyparse.
But as a consequence yyexpected_tokens crashes at the very beginning
of the parse, since, for instance, the stacks are not even set up.
See https://lists.gnu.org/r/bison-patches/2020-03/msg00001.html.
The fix could have very simple, but the documentation actually makes
it very clear that we can reuse a pstate for several parses:
After yypush_parse returns a status other than YYPUSH_MORE, the
parser instance yyps may be reused for a new parse.
so we need to restore the parser to its pristine state so that (i) it
is ready to run the next parse, (ii) it properly supports
yyexpected_tokens for the next run.
* data/skeletons/yacc.c (b4_initialize_parser_state_variables): New,
extracted from the top of yyparse/yypush_parse.
(yypstate_clear): New.
(yypstate_new): Use it when push parsers are enabled.
Define after the yyps macros so that we can use the same code as the
regular pull parsers.
(yyparse): Use it when push parsers are _not_ enabled.
* examples/c/bistromathic/bistromathic.test: Check the completion on
the beginning of the line.
These macros have been extremely useful when we had to support K&R C,
which we dropped long ago. Now, they merely make the code uselessly
hard to read.
* data/skeletons/c.m4, data/skeletons/glr.c, data/skeletons/glr.cc,
* data/skeletons/yacc.c:
Stop using b4_function_define.
Since Bison 2.7, output was indented four spaces for explanatory
statements. For example:
input.y:2.7-13: error: %type redeclaration for exp
input.y:1.7-11: previous declaration
Since the introduction of caret-diagnostics, it became less clear.
Remove the indentation and display submessages as in GCC:
input.y:2.7-13: error: %type redeclaration for exp
2 | %type <float> exp
| ^~~~~~~
input.y:1.7-11: note: previous declaration
1 | %type <int> exp
| ^~~~~
* src/complain.h (SUB_INDENT): Remove.
(warnings): Add "note" to the enum.
* src/complain.h, src/complain.c (complain_indent): Replace by...
(subcomplain): this.
Adjust all dependencies.
* tests/actions.at, tests/diagnostics.at, tests/glr-regression.at,
* tests/input.at, tests/named-refs.at, tests/regression.at:
Adjust expectations.
This revealed a number of things I had not realized:
- the Java location tracking was aliasing the same pair of positions
for all the symbols (see previous commit).
- in impure parsers, it's quite easy to use incorrect locations for
diagnostics, since yyerror uses yylloc, which is the location of the
lookahead, not that of the current lhs. So we need something like
{
YYLTYPE old_yylloc = yylloc;
yylloc = @$;
yyerror (]AT_PARAM_IF([result, count, nerrs, ])[buf);
yylloc = old_yylloc;
}
Maybe we should do that little yylloc dance in the skeleton instead
of leaving it to the user? It might be costly... But that's only
for users of the impure parsers, which are asking for trouble
anyway.
- in glr.cc invoking yyerror is somewhat cumbersome: the C++ interface
is not available as we are in yyparse (which in C), and yyerror is
used by glr.cc itself to bind it to the user's parser::error. If we
call yyerror, we need:
yyerror (]AT_LOCATION_IF([[&@$, ]])[yyparser, ]AT_PARAM_IF([result, count, nerrs, ])[msg);
However calling yy::parser::error is easier, once we know that the
current parser object is available as 'yyparser'. Which also saves
us from having to pass the parse-params ourselves:
yyparser.error (]AT_LOCATION_IF([[@$, ]])[msg);
* tests/calc.at: Invoke yyerror by hand, instead of using fprintf etc.
Adjust expectations.
* data/skeletons/lalr1.java (yyexpectedTokens)
(yysyntaxErrorArguments): Make them methods of Context.
(Context.yysymbolName): New.
* tests/local.at: Adjust.
Unfortunately in the Java skeleton the user cannot override the way
locations are displayed, and locations don't know the structure of the
positions. So they cannot implement the tricks used in the C/C++
skeletons to display "1.1" instead of "1.1-1.2".
* tests/local.at (Java): Add support for column tracking in the
locations, as we did in examples/java/calc.
* tests/calc.at: Use AT_CALC_YYLEX.
* data/skeletons/glr.c (YYASSERT): Rename as...
(YY_ASSERT): this, for consistency with yacc.c, and also to emphasize
the fact that this is not for the end user (YY_ prefix).
* tests/glr-regression.at: Define parse.assert.
It is not used. And its implementation was wrong when api.token.raw
was defined, as it was still mapping to the external token numbers,
instead of the internal ones. Besides it was provided only when
api.token.constructor is defined, yet always declared.
* data/skeletons/c++.m4 (by_type::token): Remove, useless.
* data/skeletons/lalr1.d, data/skeletons/lalr1.java (yytoken_number_):
Remove, useless.
Was used in ancient C skeletons to support YYPRINT, long obsoleted by
%printer.
* data/skeletons/location.cc: Remove the u (for unsigned) suffix from
the initial line and column.
* NEWS: AFAICT, only C++ backends have their location types changed.
* data/skeletons/yacc.c (YYPTRDIFF_T, YYPTRDIFF_MAXIMUM):
Default to long, not int.
(yy_lac_stack_realloc, yy_lac, yytnamerr, yyparse):
Avoid casts to YYPTRDIFF_T that were masking the problem.
I no longer agree with that item, there are indeed two things to
report: lack of definition, and being useless. We could have either
one without the other, they are not directly related.
input.c: In function 'int yyparse()':
input.c: error: conversion to 'long int' from 'long unsigned int'
may change the sign of the result [-Werror=sign-conversion]
yyes_capacity = sizeof yyesa / sizeof *yyes;
^
cc1plus: all warnings being treated as errors
* data/skeletons/yacc.c: here.
This is an experiment. Maybe more styles will be used (in which case
a short-hand function will be useful), maybe it will be just reverted.
* data/bison-default.css (.traces0): New.
* src/lalr.c (lalr): Use it.
* cfg.mk: Disable checks where needed (e.g., we do want to check the
behavior with tabs).
(sc_at_parser_check): Remove. Unfortunately since
a11c144609 we no longer use the './'
prefix to run programs in the current directory. That was so that we
could run Java programs like the other, although they are no run with
the `./` prefix (see 967a59d2c0).
As a consequence this sc check no longer makes sense.
However, since now AT_PARSER_CHECK passes the `./` prefix itself, this
sc-check was superfluous.
* examples/c/reccalc/scan.l: Use memcpy, not strncpy.
* src/ielr.c, src/reader.c: Obfuscate "lr(0)" so that the sc-check for
"space before paren" does not fire.
* tests/diagnostics.at: Avoid space-tab, use tab-tab.
We were using the gnulib's gettext module with tricks in
bootstrap.conf to avoid useless files. Instead, use gnulib's
gettext-h module.
* .travis.yml: Force Gettext 0.18.3 on Trusty.
* bootstrap.conf: Use gettext-h instead of gettext.
(excluded_files): Remove.
* configure.ac (AM_GNU_GETTEXT_VERSION): Bump to 0.19.
Currently we have no simple example: rpcalc in reverse Polish, mfcalc
has functions, and lexcalc is using lex.
* examples/c/calc/Makefile, examples/c/calc/calc.y,
* examples/c/calc/calc.test, examples/c/calc/local.mk: New.
I personally prefer 'non terminal', or 'non-terminal', but
'nonterminal' is the common spelling.
* data/glr.c, src/parse-gram.y, src/symtab.c, src/symtab.h,
* tests/input.at, doc/refcard.tex: here.
Currently our error messages include both "symbol redeclared" and
"symbol redefined", and they mean something different. This is
obscure, let's make this clearer.
I think the idea between 'definition' vs. 'declaration' is that in the
case of the nonterminals, the actual definition is its set of rules,
so %nterm would be about declaration. The case of %token is less
clear.
* src/symtab.c (complain_class_redefined): New.
(symbol_class_set): Use it.
Simplify the logic of this function to clearly skip its body when the
preconditions are not met.
* tests/input.at (Symbol class redefinition): New.
Reported by Derek Clegg.
http://lists.gnu.org/archive/html/bug-bison/2018-10/msg00018.html
Rather than adding casts, we should be more careful with types. For
instance yystate should be a yytype_int16. But currently we can't: it
is also used sometimes for storing other things that state numbers.
* data/yacc.c (yyparse): Add missing casts.
