Now superseded by 3.6.91. > Le 4 juil. 2020 à 14:57, Akim Demaille <[email protected]> a écrit : > > > Hi all, > > I am super excited to announce the forthcoming release of Bison 3.7, whose > main novelty, contributed by Vincent Imbimbo, is the generation of > counterexamples for conflicts. For instance on a grammar featuring the > infamous "dangling else" problem, "bison -Wcounterexamples" now gives: > > dangling.y: warning: 1 shift/reduce conflict [-Wconflicts-sr] > Shift/reduce conflict on token "else": > Example "if" exp "if" exp exp • "else" exp > First derivation exp ::=[ "if" exp exp ::=[ "if" exp exp • ] "else" exp ] > Second derivation exp ::=[ "if" exp exp ::=[ "if" exp exp • "else" exp ] ] > > which proves that the grammar is ambiguous by exhibiting a test sample with > two derivations (corresponding to two parse trees). > > When Bison is installed with text styling enabled, the example is actually > shown twice, with colors demonstrating the ambiguity (see > https://www.lrde.epita.fr/~akim/private/bison/dangling-else.png). > > Joshua Watt contributed the option `--file-prefix-map OLD=NEW`, to make > reproducible builds. > > See the NEWS below for more details. > > We *need* feedback on this beta. Not just on counterexamples, there were > other changes affecting all the skeletons. > > *Please* *,* *pretty* *please* *,* *test* *it* *!* > > Feedback on the format of the counterexamples would also be most useful.
Here are the compressed sources: https://alpha.gnu.org/gnu/bison/bison-3.6.91.tar.gz (5.1MB) https://alpha.gnu.org/gnu/bison/bison-3.6.91.tar.lz (3.1MB) https://alpha.gnu.org/gnu/bison/bison-3.6.91.tar.xz (3.1MB) Here are the GPG detached signatures[*]: https://alpha.gnu.org/gnu/bison/bison-3.6.91.tar.gz.sig https://alpha.gnu.org/gnu/bison/bison-3.6.91.tar.lz.sig https://alpha.gnu.org/gnu/bison/bison-3.6.91.tar.xz.sig Cheers!
