When a pstate is used for multiple successive parses, some state may
leak from one run into the following one. That was introduced in
330552ea49 "yacc.c: push: don't clear
the parser state when accepting/rejecting".
Reported by Ryan <[email protected]>
https://lists.gnu.org/r/bug-bison/2021-03/msg00000.html
* data/skeletons/yacc.c (yypush_parse): We reusing a pstate from a
previous run, do behave as if it were the first run.
* tests/push.at (Pstate reuse): Check this.
The right-shift added in c22902e360
("tables: fix handling for useless tokens") is incorrect. In
particular, we need to reset the "new" bits.
Reported by Balázs Scheidler.
https://github.com/akimd/bison/issues/74
* src/tables.c (pos_set_set): Fix the right-shift.
In some rare conditions, the generated parser can be wrong when there
are useless tokens.
Reported by Balázs Scheidler.
https://github.com/akimd/bison/issues/72
Balázs managed to prove that the bug was introduced in
commit af1c6f973a
Author: Theophile Ranquet <[email protected]>
Date: Tue Nov 13 10:38:49 2012 +0000
tables: use bitsets for a performance boost
Suggested by Yuri at
<http://lists.gnu.org/archive/html/bison-patches/2012-01/msg00000.html>.
The improvement is marginal for most grammars, but notable for large
grammars (e.g., PosgreSQL's postgre.y), and very large for the
sample.y grammar submitted by Yuri in
http://lists.gnu.org/archive/html/bison-patches/2012-01/msg00012.html.
Measured with --trace=time -fsyntax-only.
parser action tables postgre.y sample.y
Before 0,129 (44%) 37,095 (99%)
After 0,117 (42%) 5,046 (93%)
* src/tables.c (pos): Replace this set of integer coded as an unsorted
array of integers with...
(pos_set): this bitset.
which was implemented long ago, but that I installed only recently
(March 2019), first published in v3.3.90.
That patch introduces a bitset to represent a set of integers. It
managed negative integers by using a (fixed) base (the smallest
integer to represent). It avoided negative accesses into the bitset
by ignoring integers smaller than the base, under the asumption that
these cases correspond to useless tokens that are ignored anyway.
While it turns out to be true for all the test cases in the test suite
(!), Balázs' use case demonstrates that it is not always the case.
So we need to be able to accept negative integers that are smaller
than the current base.
"Amusingly" enough, the aforementioned patch was visibly unsure about
itself:
/* Store PLACE into POS_SET. PLACE might not belong to the set
of possible values for instance with useless tokens. It
would be more satisfying to eliminate the need for this
'if'. */
This commit needs several improvements in the future:
- support from bitset for bit assignment and shifts
- amortized resizing of pos_set
- test cases
* src/tables.c (pos_set_base, pos_set_dump, pos_set_set, pos_set_test):
New.
Use them instead of using bitset_set and bitset_test directly.
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 <[email protected]>.
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.
Before:
YY_ASSERT (tok == token::YYEOF || tok == token::YYerror || tok == token::YYUNDEF || tok == 120 || tok == 49 || tok == 50 || tok == 51 || tok == 52 || tok == 53 || tok == 54 || tok == 55 || tok == 56 || tok == 57 || tok == 97 || tok == 98);
After:
YY_ASSERT (tok == token::YYEOF
|| (token::YYerror <= tok && tok <= token::YYUNDEF)
|| tok == 120
|| (49 <= tok && tok <= 57)
|| (97 <= tok && tok <= 98));
Clauses are now also wrapped on several lines. This is nicer to read
and diff, but also avoids pushing Visual C++ to its arbitrary
limits (640K and lines of 16380 bytes ought to be enough for anybody,
otherwise make an C2026 error).
The useless parens are there for the dummy warnings about
precedence (in the future, will we also have to put parens in
`1+2*3`?).
* data/skeletons/variant.hh (_b4_filter_tokens, b4_tok_in, b4_tok_in):
New.
(_b4_token_constructor_define): Use them.
Working on the previous commit I realized that YY_ASSERT was used in
the generated headers, so must follow api.prefix to avoid clashes when
multiple C++ parser with variants are used.
Actually many more macros should obey api.prefix (YY_CPLUSPLUS,
YY_COPY, etc.). There was no complaint so far, so it's not urgent
enough for 3.7.4, but it should be addressed in 3.8.
* data/skeletons/variant.hh (b4_assert): New.
Use it.
* tests/local.at (AT_YYLEX_RETURN): Fix.
* tests/headers.at: Make sure variant-based C++ parsers are checked
too.
This test did find that YY_ASSERT escaped renaming (before the fix in
this commit).
In some extreme situations (about 800 tokens), we generate a
single-line assertion long enough for Visual C++ to discard the end of
the line, thus falling into parse ends for the missing `);`. On a
shorter example:
YY_ASSERT (tok == token::TOK_YYEOF || tok == token::TOK_YYerror || tok == token::TOK_YYUNDEF || tok == token::TOK_ASSIGN || tok == token::TOK_MINUS || tok == token::TOK_PLUS || tok == token::TOK_STAR || tok == token::TOK_SLASH || tok == token::TOK_LPAREN || tok == token::TOK_RPAREN);
Whether NDEBUG is used or not is irrelevant, the parser dies anyway.
Reported by Jot Dot <[email protected]>.
https://lists.gnu.org/r/bug-bison/2020-11/msg00002.html
We should avoid emitting lines so long.
We probably should also use a range-based assertion (with extraneous
parens to pacify fascist compilers):
YY_ASSERT ((token::TOK_YYEOF <= tok && tok <= token::TOK_YYUNDEF)
|| (token::TOK_ASSIGN <= tok && ...)
But anyway, we should simply not emit this assertion at all when not
asked for.
* data/skeletons/variant.hh: Do not define, nor use, YY_ASSERT when it
is not enabled.
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 <[email protected]>.
https://github.com/akimd/bison/issues/31https://lists.gnu.org/r/bison-patches/2020-05/msg00055.html
Reported by Claudio Calvelli <[email protected]>.
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.
Reported by Dennis Clarke.
https://lists.gnu.org/r/bug-bison/2020-08/msg00013.html
* examples/d/local.mk, examples/java/calc/local.mk,
* examples/java/simple/local.mk: Pass bison's options before its
argument, in case we're in POSIX mode.
An assertion failed when the last character is a '\' and we're in a
character or a string.
Reported by Agency for Defense Development.
https://lists.gnu.org/r/bug-bison/2020-08/msg00009.html
* src/scan-gram.l: Catch unterminated escapes.
* tests/input.at (Unexpected end of file): New.
Reported by Agency for Defense Development.
https://lists.gnu.org/r/bug-bison/2020-08/msg00008.html
On an empty such as
%token FOO
BAR
FOO 0
%%
input: %empty
we crash because when we find FOO 0, we decrement ntokens (since FOO
was discovered to be EOF, which is already known to be a token, so we
increment ntokens for it, and need to cancel this). This "works well"
when EOF is properly defined in one go, but here it is first defined
and later only assign token code 0. In the meanwhile BAR was given
the token number that we just decremented.
To fix this, assign symbol numbers after parsing, not during parsing,
so that we also saw all the explicit token codes. To maintain the
current numbers (I'd like to keep no difference in the output, not
just equivalence), we need to make sure the symbols are numbered in
the same order: that of appearance in the source file. So we need the
locations to be correct, which was almost the case, except for nterms
that appeared several times as LHS (i.e., several times as "foo:
..."). Fixing the use of location_of_lhs sufficed (it appears it was
intended for this use, but its implementation was unfinished: it was
always set to "false" only).
* src/symtab.c (symbol_location_as_lhs_set): Update location_of_lhs.
(symbol_code_set): Remove broken hack that decremented ntokens.
(symbol_class_set, dummy_symbol_get): Don't set number, ntokens and
nnterms.
(symbol_check_defined): Do it.
(symbols): Don't count nsyms here.
Actually, don't count nsyms at all: let it be done in...
* src/reader.c (check_and_convert_grammar): here. Define nsyms from
ntokens and nnterms after parsing.
* tests/input.at (EOF redeclared): New.
* examples/c/bistromathic/bistromathic.test: Adjust the traces: in
"%nterm <double> exp %% input: ...", exp used to be numbered before
input.
* cfg.mk (_space_before_paren_exempt): Be less laxist.
* src/output.c, src/reader.c: Fix space before paren issues.
Pacify the warnings where applicable.
Older versions of GCC (4.1.2 here) don't like repeated typedefs.
CC src/bison-parse-simulation.o
src/parse-simulation.c:61: error: redefinition of typedef 'parse_state'
src/parse-simulation.h:74: error: previous declaration of 'parse_state' was here
make: *** [Makefile:7876: src/bison-parse-simulation.o] Error 1
Reported by Nelson H. F. Beebe.
* src/parse-simulation.c (parse_state): Don't typedef,
parse-simulation.h did it already.
This reverts commit d0bec3175f (which
should have read "We have a clash...", not "With have a clash...").
Now that `max()` was renamed `max_int()`, we can use `max` again, as
elsewhere in the code.
* src/counterexample.c (visited_hasher): Alpha reconversion.
Reported by Maarten De Braekeleer.
https://lists.gnu.org/r/bison-patches/2020-07/msg00080.html
We don't want to use gnulib's min and max macros, since we use
function calls in min/max arguments.
* src/location.c (max_int, min_int): Move to...
* src/system.h: here.
* src/counterexample.c, src/derivation.c: Use max_int instead of max.
From
foo.y:1.7-11: error: %type redeclaration for bar
1 | %type <foo> bar bar
| ^~~~~
foo.y:1.7-11: note: previous declaration
1 | %type <foo> bar bar
| ^~~~~
to
foo.y:1.17-19: error: %type redeclaration for bar
1 | %type <foo> bar bar
| ^~~
foo.y:1.13-15: note: previous declaration
1 | %type <foo> bar bar
| ^~~
* src/symlist.h, src/symlist.c (symbol_list_type_set): There's no need
for the tag's location, use that of the symbol.
* src/parse-gram.y: Adjust.
* tests/input.at: Adjust.
We crash if the input contains a string containing a NUL byte.
Reported by Suhwan Song.
https://lists.gnu.org/r/bug-bison/2020-07/msg00051.html
* src/flex-scanner.h (STRING_FREE): Avoid accidental use of
last_string.
* src/scan-gram.l: Don't call STRING_FREE without calling
STRING_FINISH first.
* tests/input.at (Invalid inputs): Check that case.
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.
With have a clash with the "max" function.
src/counterexample.c: In function 'visited_hasher':
src/counterexample.c:720:48: error: declaration of 'max' shadows a global declaration [-Werror=shadow]
src/counterexample.c:116:12: error: shadowed declaration is here [-Werror=shadow]
* src/counterexample.c (visited_hasher): Alpha conversion.
Fix 6b78e50cef, "cex: make "rerun with
'-Wcex'" a note instead of a warning"
* tests/conflicts.at (-W versus %expect and %expect-rr): Fix
expectations.
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.
Currently the suggestion to rerun is a -Wother warning:
warning: 2 shift/reduce conflicts [-Wconflicts-sr]
warning: rerun with option '-Wcounterexamples' to generate conflict counterexamples [-Wother]
Instead, let's attach it as a subnote of the diagnostic (in the
current case, -Wconflicts-sr):
warning: 2 shift/reduce conflicts [-Wconflicts-sr]
note: rerun with option '-Wcounterexamples' to generate conflict counterexamples
* src/conflicts.c (conflicts_print): Do that.
Adjust the test suite.
From
input.y: warning: reduce/reduce conflict on token $end [-Wcounterexamples]
Example: A b .
First derivation
a
`-> A b .
Second derivation
a
`-> A b
`-> b .
to
input.y: warning: reduce/reduce conflict on token $end [-Wcounterexamples]
Example: A b .
First reduce derivation
a
`-> A b .
Second reduce derivation
a
`-> A b
`-> b .
* src/counterexample.c (print_counterexample): here.
Compute the width of the labels to properly align the values.
* tests/conflicts.at, tests/counterexample.at, tests/diagnostics.at,
* tests/report.at: Adjust.
Now that the derivation is no longer printed on one line, aligning the
example and the derivation is no longer useful. It can actually be
harmful, as it makes the overall structure less clear.
* src/derivation.h, src/derivation.c (derivation_print_leaves): Remove
the `prefix` argument.
* src/counterexample.c (print_counterexample): Put the example next to
its label.
* tests/conflicts.at, tests/counterexample.at, tests/diagnostics.at,
* tests/report.at: Adjust.
Akim Demaille