Release Notes: Several deprecated features were removed, such as support for YYFAIL, yystype, yyltype, YYLEX_PARAM, and YYPARSE_PARAM. The user epilogue is no longer affected by internal #defines. The recently-introduced dependency on stdio.h when locations are enabled was removed. Caret errors, as introduced in 2.7, are now activated by default. The "-Werror" option was enhanced, and categorization of warnings and errors was modified. Many other changes and various bugfixes were made.
Release Notes: Compiler attribute portability was fixed. Compiler warnings were eliminated.
Release Notes: %language is no longer an experimental feature. Experimental exception safety was introduced. Compiler warnings from Bison-generated parsers are now fully avoided. The formats of error messages and reports was slightly modified. Various minor bugs were fixed.
Release Notes: Generated headers are now guarded against multiple inclusion. A new variable "api.prefix" has been introduced to replace "%name-prefix". Warnings for stray "@" or "$" in actions have been expanded. Creation of spurious whitespace and empty lines is now avoided. Various further minor fixes and improvements have been made.
Release Notes: Support was added for dashes in grammar symbol names, for named references in semantic actions such as "$sym" instead of "$1", and for LAC (Lookahead Correction) for syntax error handling. Bison can now generate IELR(1) and canonical LR(1) parser tables in place of its traditional LALR(1) parser tables. Fixes were made for %error-verbose syntax error messages. Many other improvements and bugfixes were made.
Release Notes: Some portability problems as well as some failures in the test suite were resolved. Detection of GNU M4 1.4.6 or newer during configure was improved. %code is now a permanent feature. YYFAIL is deprecated and pending removal. Bison now obeys "-Werror" and "--warnings=error" for warnings about grammar rules that are useless in the parser due to conflicts. Several other minor changes were made and bugs were fixed.
Release Notes: Many major changes were made since 2.1, which was released 4 years ago.
Release Notes: Several new directives were added. GLR grammars now support locations. %token numbers can now be hexadecimal integers. A POSIX conformant yacc command and -ly library installation can now be disabled at build. Numbers are no longer arbitrarily limited to 16-bit counts. Semicolons are now allowed before "|" in grammar rules, as POSIX requires. Bison-generated parsers no longer default to using the alloca function to extend the parser stack. Furthermore, there have been incompatible changes to error token location, semicolon handling, and NUL byte and newline handling.
Release Notes: Minor bugfixes and a wrapper script to emulate yacc.