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: %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: 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.