X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/4febdd9667393ee2f1345540c30185bba337d52c..95f22ad2a777be59535616142910f8914dac6f26:/NEWS diff --git a/NEWS b/NEWS index a2c7e5a1..a3130f93 100644 --- a/NEWS +++ b/NEWS @@ -1,47 +1,69 @@ Bison News ---------- -Changes in version 1.875d: +Changes in version 2.0, 2004-12-25: -* Unescaped newlines are no longer allowed in character constants or - string literals. They were never portable, and GCC 3.4.0 has - dropped support for them. Better diagnostics are now generated if - forget a closing quote. +* Possibly-incompatible changes -* NUL bytes are no longer allowed in Bison string literals, unfortunately. + - Bison-generated parsers no longer default to using the alloca function + (when available) to extend the parser stack, due to widespread + problems in unchecked stack-overflow detection. You can "#define + YYSTACK_USE_ALLOCA 1" to require the use of alloca, but please read + the manual to determine safe values for YYMAXDEPTH in that case. -* %token numbers can now be hexadecimal integers, e.g., `%token FOO 0x12d'. - This is a GNU extension. + - Error token location. + During error recovery, the location of the syntax error is updated + to cover the whole sequence covered by the error token: it includes + the shifted symbols thrown away during the first part of the error + recovery, and the lookahead rejected during the second part. -* A new directive "%expect-rr N" specifies the expected number of - reduce/reduce conflicts in GLR parsers. + - Semicolon changes: + . Stray semicolons are no longer allowed at the start of a grammar. + . Semicolons are now required after in-grammar declarations. -* Experimental %destructor support has been added to lalr1.cc. + - Unescaped newlines are no longer allowed in character constants or + string literals. They were never portable, and GCC 3.4.0 has + dropped support for them. Better diagnostics are now generated if + forget a closing quote. -Changes in version 1.875c, 2003-08-25: + - NUL bytes are no longer allowed in Bison string literals, unfortunately. - (Just bug fixes.) +* New features -Changes in version 1.875b, 2003-06-17: + - GLR grammars now support locations. -* GLR grammars now support locations. + - New directive: %initial-action. + This directive allows the user to run arbitrary code (including + initializing @$) from yyparse before parsing starts. -* Semicolon changes: - - Semicolons are now allowed before "|" in grammar rules, as POSIX requires. - - Stray semicolons are no longer allowed at the start of a grammar. - - Semicolons are now required after in-grammar declarations. + - A new directive "%expect-rr N" specifies the expected number of + reduce/reduce conflicts in GLR parsers. + + - %token numbers can now be hexadecimal integers, e.g., `%token FOO 0x12d'. + This is a GNU extension. + + - The option `--report=lookahead' was changed to `--report=look-ahead'. + The old spelling still works, but is not documented and will be + removed. + + - Experimental %destructor support has been added to lalr1.cc. -Changes in version 1.875a, 2003-02-01: + - New configure option --disable-yacc, to disable installation of the + yacc command and -ly library introduced in 1.875 for POSIX conformance. -* For now, %expect-count violations are now just warnings, not errors. - This is for compatibility with Bison 1.75 and earlier (when there are - reduce/reduce conflicts) and with Bison 1.30 and earlier (when there - are too many or too few shift/reduce conflicts). However, in future - versions of Bison we plan to improve the %expect machinery so that - these violations will become errors again. +* Bug fixes -* New configure option --disable-yacc, to disable installation of the - yacc command and -ly library introduced in 1.875 for POSIX conformance. + - For now, %expect-count violations are now just warnings, not errors. + This is for compatibility with Bison 1.75 and earlier (when there are + reduce/reduce conflicts) and with Bison 1.30 and earlier (when there + are too many or too few shift/reduce conflicts). However, in future + versions of Bison we plan to improve the %expect machinery so that + these violations will become errors again. + + - Within Bison itself, numbers (e.g., goto numbers) are no longer + arbitrarily limited to 16-bit counts. + + - Semicolons are now allowed before "|" in grammar rules, as POSIX requires. Changes in version 1.875, 2003-01-01: @@ -213,7 +235,8 @@ Changes in version 1.50, 2002-10-04: allowed some non-error action other than a default reduction on the error token. The new behavior has long been the documented behavior, and has long been required by POSIX. For more details, please see - . + Paul Eggert, "Reductions during Bison error handling" (2002-05-20) + . * Traces Popped tokens and nonterminals are now reported. @@ -288,8 +311,8 @@ Changes in version 1.50, 2002-10-04: produces additional information: - itemset complete the core item sets with their closure - - lookahead - explicitly associate lookaheads to items + - lookahead [changed to `look-ahead' in 1.875e and later] + explicitly associate look-ahead tokens to items - solved describe shift/reduce conflicts solving. Bison used to systematically output this information on top of