The code was written on top of buffers of `char[26]`, and then was
changed to use `char *`, yet was still using `sizeof buf`, which
became `sizeof (char *)` instead of `sizeof (char[26])`.
Reported by Dagobert Michelsen.
https://lists.gnu.org/r/bug-bison/2020-07/msg00023.html
* src/glyphs.h, src/glyphs.c: Get rid of uses of `char *`, use only
glyph_buffer_t.
Sometimes, understanding the derivations is difficult, because they
are serialized to fit in one line. For instance, the example taken
from the NEWS file:
%token ID
%%
s: a ID
a: expr
expr: expr ID ',' | "expr"
gave
First example expr • ID ',' ID $end
Shift derivation $accept → [ s → [ a → [ expr → [ expr • ID ',' ] ] ID ] $end ]
Second example expr • ID $end
Reduce derivation $accept → [ s → [ a → [ expr • ] ID ] $end ]
Printing as trees, it gives:
First example expr • ID ',' ID $end
Shift derivation
$accept
↳ s $end
↳ a ID
↳ expr
↳ expr • ID ','
Second example expr • ID $end
Reduce derivation
$accept
↳ s $end
↳ a ID
↳ expr •
* src/glyphs.h, src/glyphs.c (down_arrow, empty, derivation_separator):
New.
* src/derivation.c (derivation_print, derivation_print_impl): Rename
as...
(derivation_print_flat, derivation_print_flat_impl): These.
(fputs_if, derivation_depth, derivation_width, derivation_print_tree)
(derivation_print_tree_impl, derivation_print): New.
* src/counterexample.c (print_counterexample): Adjust.
* tests/conflicts.at, tests/counterexample.at, tests/diagnostics.at,
* tests/report.at: Adjust.
When reporting counterexamples for s/r conflicts, put the shift first.
This is more natural, and displays the default resolution first, which
is also what happens for r/r conflicts where the smallest rule number
is displayed first, and "wins".
* src/counterexample.c (counterexample): Add a shift_reduce member.
(new_counterexample): Adjust.
Swap the derivations when this is a s/r conflict.
(print_counterexample): For s/r conflicts, prefer "Shift derivation"
and "Reduce derivation" rather than "First/Second derivation".
* tests/conflicts.at, tests/counterexample.at, tests/report.at: Adjust.
* NEWS, doc/bison.texi: Ditto.
Currently we use both names. Let's stick to the short one.
* src/AnnotationList.c, src/conflicts.c, src/counterexample.c,
* src/getargs.c, src/getargs.h, src/graphviz.c, src/ielr.c,
* src/lalr.c, src/print-graph.c, src/print-xml.c, src/print.c,
* src/state-item.c, src/state.c, src/state.h, src/tables.c:
s/lookahead_token/lookahead/gi.
* src/counterexample.c, src/parse-simulation.c: It is more usual in
Bison to use sizeof on expressions than on types, especially for
allocation.
Let the compiler do it's job instead of calling memcpy ourselves.
There are too many gl_list_t in there, it's hard to understand what is
going on. Introduce and use more precise types. I sure can be wrong
in some places, it's hard to tell without proper tool support.
* src/counterexample.c, src/lssi.c, src/lssi.h, src/parse-simulation.c,
* src/parse-simulation.h, src/state-item.c, src/state-item.h
(si_bfs_node_list, search_state_list, ssb_list, lssi_list)
(state_item_list): New.
It does not make a lot of sense to use ::= in our counterexamples,
that's not something that belongs to the Bison "vocabulary". Using
the colon makes sense, but it's too discreet. Let's use the arrow,
which we already use in some reports (HTML and Dot).
* src/gram.h (print_dot_fallback): Generalize into...
(print_fallback): this.
(print_arrow): New.
* src/derivation.c: Use it.
* NEWS, tests/conflicts.at, tests/counterexample.at,
* tests/diagnostics.at, tests/report.at: Adjust.
* doc/bison.texi: Ditto.
Unfortunately the literal `→` is output as `↦`. So we need to use
@arrow.
Prefer `&foos[i]` to `foos + i` when `foos` is an array. IMHO, it
makes the semantics clearer.
* src/counterexample.c, src/lssi.c, src/parse-simulation.c,
* src/state-item.c: With arrays, prefer the array notation rather than
the pointer one.
* examples/c/bistromathic/parse.y (user_context): We need the current
line.
(yyreport_syntax_error): Quote the guilty line, with squiggles.
* examples/c/bistromathic/bistromathic.test: Adjust.
Currently autocompletion on a line with errors leaks the error
messages. It can be useful to let the user know, but GNU Readline
does not provide us with an nice way to display the error. So we
actually break into the current line of the user.
So instead, do not show these errors.
* examples/c/bistromathic/parse.y (user_context): New.
Use %param to pass it to the parser and scanner.
Keep quiet when in computing autocompletion.
That quite defeats the whole point of locations... But anyway, we
should not see these messages at all.
* examples/c/bistromathic/parse.y (expected_tokens): Fix (useless)
location tracking.
Currently when we output useless rules, they appear before the
grammar, but using the same invocation. As a result, the anchor is
defined twice, and the wrong one, being first, is honored.
* data/xslt/xml2xhtml.xsl (rule): Take a new 'anchor' parameter to
decide whether being an anchor, or a target.
Let it be true when output the grammar.
* tests/report.at: Adjust.
The text and Dot reports are expected to be identical when generated
directly (--report, --graph) or indirectly (via XML). The xml
testsuite had not be run for ages, let it catch up a bit.
* src/print-xml.c: Pass the type of the symbols.
* data/xslt/xml2text.xsl
Catch up with the new layout.
Display the symbol types.
Use '•', not '.'
* tests/local.at: Smash '•' to '.' when matching against the direct
text report.
* tests/report.at: Adjust XML expectations.
* data/skeletons/c++.m4, data/skeletons/glr.c, data/skeletons/lalr1.d,
* data/skeletons/lalr1.java, data/skeletons/yacc.c:
Be more accurate about yychar and yytoken.
Don't name local variables as if they were members.
* examples/c/bistromathic/parse.y, examples/c/lexcalc/parse.y,
* examples/c/reccalc/parse.y: here.
Add some comments.
* src/parse-gram.y (api_version): Pull out of handle_require.
Bump to 3.7.
* data/bison-default.css: Cobalt does not seem to be supported.
* doc/bison.texi (Counterexamples): A new section.
(Understanding): Show the counterexamples as it shows in the report:
with its items.
(Bison Options): Document -Wcex and -rcex.
In commit c80cdf2db2 ("doc: simplify
uses of @ref", Jan 27 2020, released in Bison 3.6), I broke the
references to the Bibliography. For instance:
For a more detailed exposition of the mysterious behavior in LALR parsers
-and the benefits of IELR, @pxref{Bibliography,,Denny 2008 March}, and
-@ref{Bibliography,,Denny 2010 November}.
+and the benefits of IELR, @pxref{Bibliography}, and
+@ref{Bibliography}.
which results in "see Bibliography" twice, instead of the more precise
reference.
* doc/bison.texi (@pcite, @tcite): New.
Use them instead of @ref to Bibliography.
Cite only the first author (that's what we did for the other entries).
Currently when a push parser finishes its parsing (i.e., it did not
return YYPUSH_MORE), it also clears its state. It is therefore
impossible to see if it had parse errors.
In the context of autocompletion, because error recovery might have
fired, the parser is actually already in a different state. For
instance on `(1 + + <TAB>` in the bistromathic, because there's a
`exp: "(" error ")"` recovery rule, `1 + +` tokens have already been
popped, replaced by `error`, and autocompletions think we are ready
for the closing ")". So here, we would like to see if there was a
syntax error, yet `yynerrs` was cleared.
In the case of a successful parse, we still have a problem: if error
recovery succeeded, we won't know it, since, again, `yynerrs` is
clearer.
It seems much more natural to leave the parser state available for
analysis when there is a failure.
To reuse the parser, we should either:
1. provide an explicit means to reinitialize a parser state for future
parses.
2. automatically reset the parser state when it is used in a new
parse.
Option 2 requires to check whether we need to reinitialize the parser
each time we call `yypush_parse`, i.e., each time we give a new token.
This seems expensive compared to Option 1, but benchmarks revealed no
difference. Option 1 is incompatible with the documentation
("After `yypush_parse` returns a status other than `YYPUSH_MORE`, the
parser instance `yyps` may be reused for a new parse.").
So Option 2 wins, reusing the private `yynew` member to record that a
parse was finished, and therefore that the state must reset in the
next call to `yypull_parse`.
While at it, this implementation now reuses the previously enlarged
stacks from one parse to another.
* data/skeletons/yacc.c (yypstate_new): Set up the stacks in their
initial configurations (setting their bottom to the stack array), and
use yypstate_clear to reset them (moving their top to their bottom).
(yypstate_delete): Adjust.
(yypush_parse): At the beginning, clear yypstate if needed, and at the
end, record when yypstate needs to be clearer.
* examples/c/bistromathic/parse.y (expected_tokens): Do not propose
autocompletion when there are parse errors.
* examples/c/bistromathic/bistromathic.test: Check that case.
Currently, completion when there is a syntax error shows broken
locations.
* examples/c/bistromathic/parse.y (expected_tokens): Initialize the
location.
* examples/c/bistromathic/bistromathic.test: Check that.
The previous commit ("yacc.c: declare and initialize and the same
time") made b4_initialize_parser_state_variables useless.
* data/skeletons/yacc.c (b4_initialize_parser_state_variables): Inline
into...
(yypstate_clear): here.
In order to factor the code of push and pull parsers, the declaration
of the parser's state variable was common (being local variable in
pull parsers, and struct members in push parsers). This result in
rather poor style in pull parser, with first variable declarations,
and then their initializations.
The initialization is about to differ between push and pull parsers,
so it is no longer worth keeping both cases together.
* data/skeletons/yacc.c (b4_declare_parser_state_variables): Accept an
argument, and when it is set, initialize the variables.
Adjust dependencies.
Currently yypull_parse takes a yypstate* as argument, and accepts it
to be NULL. This does not seem to make a lot of sense: rather it is
its callers that should do that.
I believe this is historical: yypull_parse was introduced
first (c3d503425f), with yyparse being a
macro. So yyparse could hardly deal with memory allocation properly.
In 7172e23e8f that yyparse was turned
into a genuine function. At that point, it should have allocated its
own yypstate*, which would have left yypull_parse deal with only one
single non-null ypstate* argument.
Fortunately, it is nowhere documented that it is valid to pass NULL to
yypull_parse. It is now forbidden.
* data/skeletons/yacc.c (yypull_parse): Don't allocate a yypstate.
Needs a location to issue the error message.
(yyparse): Allocate the yypstate.
* README-hacking.md (Working from the Repository): Make it first to
make it easier to find the instructions to build from the repo.
(Implementation Notes): New.
* README: Provide more links.
Reported by Martin Blais and Yuriy Solodkyy.
https://lists.gnu.org/r/help-bison/2020-05/msg00011.htmlhttps://lists.gnu.org/r/bug-bison/2020-06/msg00038.html
While at it, modernize filename_type as api.filename.type and document
it properly.
* data/skeletons/c++.m4 (filename_type): Rename as...
(api.filename.type): this.
Default to const std::string.
* data/skeletons/location.cc (position, location): Expose the
filename_type type.
Use api.filename.type.
* doc/bison.texi (%define Summary): Document api.filename.type.
(C++ Location Values): Document position::filename_type.
* src/muscle-tab.c (muscle_percent_variable_update): Ensure backward
compatibility.
* tests/c++.at: Check that using const file names is ok.
tests/input.at: Check backward compat.
Reported by Dwight Guth.
https://lists.gnu.org/r/bug-bison/2020-06/msg00037.html
* src/AnnotationList.c (AnnotationList__computePredecessorAnnotations):
Beware that SBITSET__FOR_EACH nests _two_ for-loops, so "break" does
not actually break out of it.
That was the only occurrence in the code.
* src/Sbitset.h (SBITSET__FOR_EACH): Warn passersby.
* src/AnnotationList.c, src/ielr.c: Fix include order.
Prefer `res` to `result`.
Reduce scopes.
Be free of the oldish 76 cols limitation when it clutters too much the
code.
Denest when possible (we're starving for horizontal width).
AFAICT, "dotted rule" is a more frequent synonym of "item" than
"pointed rule". So let's migrate to using "dot" only.
* doc/bison.texi: Use dot/'•' rather than point/'.'.
* src/print-xml.c (print_core): Use dot rather than point. This is
not backward compatible, but AFAICT, we don't have actual user of the
XML output (but ourselves). So...
* data/xslt/xml2dot.xsl, data/xslt/xml2text.xsl,
* data/xslt/xml2xhtml.xsl, tests/report.at: ... adjust.
It makes no sense, and is actually confusing, to display twice the
same example with no visible difference.
* src/complain.h, src/complain.c (is_styled): New.
* src/counterexample.c (print_counterexample): Display the unified
example a second time only if it makes a difference.
* tests/conflicts.at, tests/counterexample.at, tests/report.at: Adjust.
* tests/diagnostics.at: Make sure we do display the unifying examples
twice when colors are enabled. And check those colors.
This was a hack to make it easier for people to migrate from yacc.c to
lalr1.cc and from glr.c to glr.cc: when set, YYSTYPE and YYLTYPE were
`#defined`. It was never documented (just mentioned in NEWS for Bison
2.2, 2006-05-19), but was used to simplify the test suite. Stop that:
adjust the test suite to the skeletons, not the converse.
In C++ use yy::parser::semantic_type, yy::parser::location_type, and
yy::parser::token::MY_TOKEN, instead of YYSTYPE, YYLTYPE and MY_TOKEN.
* data/skeletons/glr.cc, data/skeletons/lalr1.cc: Remove its support.
* tests/actions.at, tests/c++.at, tests/calc.at: Adjust.
Use of print_unicode_char suggested by Bruno Haible.
https://lists.gnu.org/r/bug-gettext/2020-06/msg00012.html
* src/gram.h (print_dot_fallback, print_dot): New.
* src/gram.c, src/derivation.c: Use it.
* tests/counterexample.at, tests/report.at: Adjust the test suite.
* .travis.yml, README-hacking.md: Adjust.
And let --report=all include the counterexamples.
* src/getargs.h, src/getargs.c (report_cex): New.
* src/main.c: Compute counterexamples when -rcex is specified.
* src/print.c: Include the counterexamples when -rcex is specified.
* tests/conflicts.at, tests/existing.at, tests/local.at: Adjust.
Instead of
Shift/reduce conflict on token D:
Example A a • D
First derivation s ::=[ A a a ::=[ b ::=[ c ::=[ • ] ] ] d ::=[ D ] ]
Example A a • D
Second derivation s ::=[ A a d ::=[ • D ] ]
display
Shift/reduce conflict on token D:
Example A a • D
First derivation s ::=[ A a a ::=[ b ::=[ c ::=[ • ] ] ] d ::=[ D ] ]
Example A a • D
Second derivation s ::=[ A a d ::=[ • D ] ]
* src/counterexample.c (print_counterexample): Indent.
* tests/counterexample.at: Adjust.
Showing the items (with the state numbers) is really something we
should restrict to the report.
* src/counterexample.c (counterexample_report_shift_reduce)
(counterexample_report_reduce_reduce): Don't show the pointed rules,
we will do that in the report.
* tests/counterexample.at: Adjust.
Akim Demaille