Bison 3.4 is about to be released. A particular focus was put on the diagnostics, which are now colored by default. Please, test/torture this beta as much as possible on your pet projects. I am especially interested in feedback on the default colors for the diagnostics: be sure to install libtextstyle before installing Bison, and please tell me if the default colors work badly with your terminal.
See below for more NEWS. Here are the compressed sources: https://alpha.gnu.org/gnu/bison/bison-3.3.91.tar.gz (4.1MB) https://alpha.gnu.org/gnu/bison/bison-3.3.91.tar.xz (3.1MB) Here are the GPG detached signatures[*]: https://alpha.gnu.org/gnu/bison/bison-3.3.91.tar.gz.sig https://alpha.gnu.org/gnu/bison/bison-3.3.91.tar.xz.sig Use a mirror for higher download bandwidth: https://www.gnu.org/order/ftp.html [*] Use a .sig file to verify that the corresponding file (without the .sig suffix) is intact. First, be sure to download both the .sig file and the corresponding tarball. Then, run a command like this: gpg --verify bison-3.3.91.tar.gz.sig If that command fails because you don't have the required public key, then run this command to import it: gpg --keyserver keys.gnupg.net --recv-keys 0DDCAA3278D5264E and rerun the 'gpg --verify' command. This release was bootstrapped with the following tools: Autoconf 2.69 Automake 1.16.1 Flex 2.6.4 Gettext 0.19.8.1 Gnulib v0.1-2564-g03752516b NEWS * Noteworthy changes in release 3.3.91 (2019-05-12) [beta] ** Bug fixes Portability issues were fixed. * Noteworthy changes in release 3.3.90 (2019-04-28) [beta] ** New features *** Colored diagnostics As an experimental feature, Bison now generates colored diagnostics, controlled by the new options --color and --style. Install the libtextstyle library before configuring Bison to use them. It is available from https://alpha.gnu.org/gnu/gettext/ for instance https://alpha.gnu.org/gnu/gettext/libtextstyle-0.8.tar.gz The option --color supports the following arguments: - always, yes: Enable colors. - never, no: Disable colors. - auto, tty (default): Enable colors if the output device is a tty. To customize the styles, create a CSS file similar to /* black-and-white.css */ .warning { } .error { font-weight: 800; text-decoration: underline; } .note { } then invoke bison with --style=black-and-white.css. *** Disabling output When given -fsyntax-only, the diagnostics are reported, but no output is generated. The name of this option is somewhat misleading as bison does more than just checking the syntax: every stage is run (including checking for conflicts for instance), except the generation of the output files. *** Include the generated header (yacc.c) Before, when --defines is used, bison generated a header, and pasted an exact copy of it into the generated parser implementation file. If the header name is not "y.tab.h", it is now #included instead of being duplicated. To use an '#include' even if the header name is "y.tab.h" (which is what happens with --yacc, or when using the Autotools' ylwrap), define api.header.include to the exact argument to pass to #include. For instance: %define api.header.include {"parse.h"} or %define api.header.include {<parser/parse.h>} *** api.location.type is now supported in C (yacc.c, glr.c) The %define variable api.location.type defines the name of the type to use for locations. When defined, Bison no longer defines YYLTYPE. This can be used in programs with several parsers to factor their definition of locations: let one of them generate them, and the others just use them. ** Changes *** Graphviz output In conformance with the recommendations of the Graphviz team, if %require "3.4" (or better) is specified, the option --graph generates a *.gv file by default, instead of *.dot. *** Diagnostics overhaul Column numbers were wrong with multibyte characters, which would also result in skewed diagnostics with carets. Beside, because we were indenting the quoted source with a single space, lines with tab characters were incorrectly underlined. To address these issues, and to be clearer, Bison now issues diagnostics as GCC9 does. For instance it used to display (there's a tab before the opening brace): foo.y:3.37-38: error: $2 of ‘expr’ has no declared type expr: expr '+' "number" { $$ = $1 + $2; } ^~ It now reports foo.y:3.37-38: error: $2 of ‘expr’ has no declared type 3 | expr: expr '+' "number" { $$ = $1 + $2; } | ^~ Other constructs now also have better locations, resulting in more precise diagnostics. *** Fix-it hints for %empty Running Bison with -Wempty-rules and --update will remove incorrect %empty annotations, and add the missing ones. *** Generated reports The format of the reports (parse.output) was improved for readability. *** Better support for --no-line. When --no-line is used, the generated files are now cleaner: no lines are generated instead of empty lines. Together with using api.header.include, that should help people saving the generated files into version control systems get smaller diffs. ** Documentation A new example in C shows an simple infix calculator with a hand-written scanner (examples/c/calc). A new example in C shows a reentrant parser (capable of recursive calls) built with Flex and Bison (examples/c/reccalc). There is a new section about the history of Yaccs and Bison. ** Bug fixes A few obscure bugs were fixed, including the second oldest (known) bug in Bison: it was there when Bison was entered in the RCS version control system, in December 1987. See the NEWS of Bison 3.3 for the previous oldest bug. _______________________________________________ help-bison@gnu.org https://lists.gnu.org/mailman/listinfo/help-bison
