When using lookahead correction, the method YYParser.Context.getExpectedTokens
is not annotated with const, because the method calls yylacCheck, which is not
const. Also, because of yylacStack and yylacEstablished, yylacCheck needs to
be called from the context of the parser class, which is sent as parameter to
the Context's constructor.
* data/skeletons/lalr1.d (yylacCheck, yylacEstablish, yylacDiscard,
yylacStack, yylacEstablished): New.
(Context): Use it.
* doc/bison.texi: Document it.
* tests/calc.at: Check it.
Changed from syntax_error to reportSyntaxError to be similar to the Java parser.
* data/skeletons/lalr1.d: Change the function name.
* doc/bison.texi: Document it.
* tests/local.at: Adjust.
* maint:
c++: shorten the assertions that check whether tokens are correct
c++: don't glue functions together
lalr1.cc: YY_ASSERT should use api.prefix
c++: don't use YY_ASSERT at all if parse.assert is disabled
c++: style: follow the Bison m4 quoting pattern
yacc.c: provide the Bison version as an integral macro
regen
style: make conversion of version string to int public
%require: accept version numbers with three parts ("3.7.4")
yacc.c: fix #definition of YYEMPTY
gnulib: update
doc: fix incorrect section title
doc: minor grammar fixes in counterexamples section
Parser.Context class returns a const YYLocation, so Lexer's method
yyerror() needs to receive the location as a const parameter.
Internal error reporting flow is changed to be similar to that of
the other skeletons. Before, case YYERRLAB was calling yyerror()
with the result of yysyntax_error() as the string parameter. As the
custom error message lets the user decide if they want to use
yyerror() or not, this flow needed to be changed. Now, case YYERRLAB
calls yyreportSyntaxError(), that builds the error message using
yysyntaxErrorArguments(). Then yyreportSyntaxError() passes the
error message to the user defined syntax_error() in case of a custom
message, or to yyerror() otherwise.
In the tests in tests/calc.at, the order of the tokens needs to be
changed in order of precedence, so that the D program outputs the
expected tokens in the same order as the other parsers.
* data/skeletons/lalr1.d: Add the custom error message feature.
* doc/bison.texi: Document it.
* examples/d/calc/calc.y: Adjust.
* tests/calc.at, tests/local.at: Test it.
This will provide the user an interface for creating custom error messages.
* data/skeletons/lalr1.d: Add the Context class.
* doc/bison.texi: Document it.
This is consistent with --defines being deprecated in favor of
--header. The directive %defines is also too similar to %define.
And %header matches nicely with api.header.name.
* src/scan-gram.l (%defines): Deprecate to %header.
(%header): Scan it.
* src/parse-gram.y (PERCENT_DEFINES): Replace with...
(PERCENT_HEADER): this.
* data/skeletons/lalr1.java
* doc/bison.texi
* tests/actions.at, tests/c++.at, tests/calc.at, tests/conflicts.at,
* tests/input.at, tests/java.at, tests/local.at, tests/output.at,
* tests/synclines.at, tests/types.at:
Convert most tests to check %header instead of %defines.
The name "defines" is incorrect, the generated file contains far more
than just #defines.
* src/getargs.h, src/getargs.c (-H, --header): New option.
With optional argument, just like --defines, --xml, etc.
(defines_flag): Rename as...
(header_flag): this.
Adjust dependencies.
* data/skeletons/bison.m4, data/skeletons/c.m4, data/skeletons/glr.c,
* data/skeletons/glr.cc, data/skeletons/glr2.cc, data/skeletons/lalr1.cc,
* data/skeletons/yacc.c:
Adjust.
* examples, doc/bison.texi: Adjust.
* tests/headers.at, tests/local.at, tests/output.at: Convert most
tests from using --defines to using --header.
Commit af000bab11 ("doc: work around
Texinfo 6.7 bug"), published in 3.4.91, added a dependency on the
"all" target.
This is a super bad idea, since "make all" will run this
target *before* "all", which builds bison. It turns out that this new
dependency actually needed bison to be built. So all the regular
process (i) build $(BUILT_SOURCES) and then (ii) build bison, was
wrecked since some of the $(BUILT_SOURCES) depended on bison...
It was "easy" to see in the logs of "make V=1" because we were
building bison files (such as src/files.o) *before* displaying the
banner for "all-recursive". With this fix, we finally get again the
proper sequence:
rm -f examples/c/reccalc/scan.stamp examples/c/reccalc/scan.stamp.tmp
/opt/local/libexec/gnubin/mkdir -p examples/c/reccalc
touch examples/c/reccalc/scan.stamp.tmp
flex -oexamples/c/reccalc/scan.c --header=examples/c/reccalc/scan.h ./examples/c/reccalc/scan.l
mv examples/c/reccalc/scan.stamp.tmp examples/c/reccalc/scan.stamp
rm -f lib/fcntl.h-t lib/fcntl.h && \
{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
...
} > lib/fcntl.h-t && \
mv lib/fcntl.h-t lib/fcntl.h
...
mv -f lib/alloca.h-t lib/alloca.h
make all-recursive
Reported by Mingli Yu <mingli.yu@windriver.com>.
https://github.com/akimd/bison/issues/31https://lists.gnu.org/r/bison-patches/2020-05/msg00055.html
Reported by Claudio Calvelli <bugb@w42.org>.
https://lists.gnu.org/r/bug-bison/2020-09/msg00001.htmlhttps://bugs.gentoo.org/716516
* doc/local.mk (all): Rename as...
(all-local): this.
So that we don't compete with BUILT_SOURCES.
On a case such as
%%
exp
: empty "a"
| "a" empty
empty
: %empty
we used to display
warning: shift/reduce conflict on token "a" [-Wcounterexamples]
Example: • "a"
Shift derivation
exp
↳ 2: • "a" empty
↳ 2: ε
Example: • "a"
Reduce derivation
exp
↳ 1: empty "a"
↳ 3: •
where the shift derivation shows an item "2: empty → ε", with an
explicit "ε", but the reduce derivation shows "3: empty → •", without
"ε".
For consistency, let's always show ε/%empty in rules with an empty
rhs:
Reduce derivation
exp
↳ 1: empty "a"
↳ 3: ε •
* src/derivation.c (derivation_width, derivation_print_tree_impl):
Always show ε/%empty in counterexamples.
* tests/diagnostics.at: Check that case.
* tests/conflicts.at, tests/counterexample.at: Adjust.
The original Texinfo macros introducing colors were made for
diagnostics, which are printed in bold. So by copy-paste accident the
styles we introduced for counterexamples were also in bold. They
should not.
* doc/bison.texi: Separate the styling of diagnostics from the styling
for counterexamples.
Don't use bold in the latter case.
Unfortunately I found no way to use the ↳ glyph in Texinfo, so I used
@arrow{} instead, which has a different width, so we have to have all
the examples doubled, once for TeX, another for the rest of the world.
* doc/bison.texi: Use the current display in the examples.
* doc/calc.y, doc/ids.y, doc/if-then-else.y, doc/sequence.y: New.
Unfortunately Texinfo somewhat mangles anchors such as `-Werror` into
`g_t_002dWerror`, so let's not include the dash.
* doc/bison.texi (Diagnostics): here.
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.
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.
* 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.
