diff options
author | Andrew Knight <andrew.knight@intopalo.com> | 2015-08-02 10:03:20 +0300 |
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committer | Jani Heikkinen <jani.heikkinen@theqtcompany.com> | 2015-08-13 04:45:21 +0000 |
commit | 3d7fe3b822615cf1d11eeff1b97d8a5927a6d5b3 (patch) | |
tree | 25de4c4c6de38e8634eead8494a22d1d42c3b45a /gnuwin32/contrib/bison/2.4.1/bison-2.4.1-src/NEWS | |
parent | d60882b0bc98875361477cb5aaf7d12c2693f900 (diff) |
gnuwin32: Remove old versions of bison/flex from the distribution
The win_flex/win_bison tools are already in the repository and working
with all projects, so the GnuWin32 versions can be removed and the
winflexbison versions can take their place.
Task-number: QTBUG-46852
Change-Id: I41bc541adab834ff83912d7a4f076a87fc174601
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>
Diffstat (limited to 'gnuwin32/contrib/bison/2.4.1/bison-2.4.1-src/NEWS')
-rw-r--r-- | gnuwin32/contrib/bison/2.4.1/bison-2.4.1-src/NEWS | 1067 |
1 files changed, 0 insertions, 1067 deletions
diff --git a/gnuwin32/contrib/bison/2.4.1/bison-2.4.1-src/NEWS b/gnuwin32/contrib/bison/2.4.1/bison-2.4.1-src/NEWS deleted file mode 100644 index 7d1a444d..00000000 --- a/gnuwin32/contrib/bison/2.4.1/bison-2.4.1-src/NEWS +++ /dev/null @@ -1,1067 +0,0 @@ -Bison News ----------- - -* Changes in version 2.4.1 (2008-12-11): - -** In the GLR defines file, unexpanded M4 macros in the yylval and yylloc - declarations have been fixed. - -** Temporary hack for adding a semicolon to the user action. - - Bison used to prepend a trailing semicolon at the end of the user - action for reductions. This allowed actions such as - - exp: exp "+" exp { $$ = $1 + $3 }; - - instead of - - exp: exp "+" exp { $$ = $1 + $3; }; - - Some grammars still depend on this `feature'. Bison 2.4.1 restores - the previous behavior in the case of C output (specifically, when - neither %language or %skeleton or equivalent command-line options - are used) to leave more time for grammars depending on the old - behavior to be adjusted. Future releases of Bison will disable this - feature. - -** A few minor improvements to the Bison manual. - -* Changes in version 2.4 (2008-11-02): - -** %language is an experimental feature. - - We first introduced this feature in test release 2.3b as a cleaner - alternative to %skeleton. Since then, we have discussed the possibility of - modifying its effect on Bison's output file names. Thus, in this release, - we consider %language to be an experimental feature that will likely evolve - in future releases. - -** Forward compatibility with GNU M4 has been improved. - -** Several bugs in the C++ skeleton and the experimental Java skeleton have been - fixed. - -* Changes in version 2.3b (2008-05-27): - -** The quotes around NAME that used to be required in the following directive - are now deprecated: - - %define NAME "VALUE" - -** The directive `%pure-parser' is now deprecated in favor of: - - %define api.pure - - which has the same effect except that Bison is more careful to warn about - unreasonable usage in the latter case. - -** Push Parsing - - Bison can now generate an LALR(1) parser in C with a push interface. That - is, instead of invoking `yyparse', which pulls tokens from `yylex', you can - push one token at a time to the parser using `yypush_parse', which will - return to the caller after processing each token. By default, the push - interface is disabled. Either of the following directives will enable it: - - %define api.push_pull "push" // Just push; does not require yylex. - %define api.push_pull "both" // Push and pull; requires yylex. - - See the new section `A Push Parser' in the Bison manual for details. - - The current push parsing interface is experimental and may evolve. More user - feedback will help to stabilize it. - -** The -g and --graph options now output graphs in Graphviz DOT format, - not VCG format. Like --graph, -g now also takes an optional FILE argument - and thus cannot be bundled with other short options. - -** Java - - Bison can now generate an LALR(1) parser in Java. The skeleton is - `data/lalr1.java'. Consider using the new %language directive instead of - %skeleton to select it. - - See the new section `Java Parsers' in the Bison manual for details. - - The current Java interface is experimental and may evolve. More user - feedback will help to stabilize it. - -** %language - - This new directive specifies the programming language of the generated - parser, which can be C (the default), C++, or Java. Besides the skeleton - that Bison uses, the directive affects the names of the generated files if - the grammar file's name ends in ".y". - -** XML Automaton Report - - Bison can now generate an XML report of the LALR(1) automaton using the new - `--xml' option. The current XML schema is experimental and may evolve. More - user feedback will help to stabilize it. - -** The grammar file may now specify the name of the parser header file using - %defines. For example: - - %defines "parser.h" - -** When reporting useless rules, useless nonterminals, and unused terminals, - Bison now employs the terms "useless in grammar" instead of "useless", - "useless in parser" instead of "never reduced", and "unused in grammar" - instead of "unused". - -** Unreachable State Removal - - Previously, Bison sometimes generated parser tables containing unreachable - states. A state can become unreachable during conflict resolution if Bison - disables a shift action leading to it from a predecessor state. Bison now: - - 1. Removes unreachable states. - - 2. Does not report any conflicts that appeared in unreachable states. - WARNING: As a result, you may need to update %expect and %expect-rr - directives in existing grammar files. - - 3. For any rule used only in such states, Bison now reports the rule as - "useless in parser due to conflicts". - - This feature can be disabled with the following directive: - - %define lr.keep_unreachable_states - - See the %define entry in the `Bison Declaration Summary' in the Bison manual - for further discussion. - -** Lookahead Set Correction in the `.output' Report - - When instructed to generate a `.output' file including lookahead sets - (using `--report=lookahead', for example), Bison now prints each reduction's - lookahead set only next to the associated state's one item that (1) is - associated with the same rule as the reduction and (2) has its dot at the end - of its RHS. Previously, Bison also erroneously printed the lookahead set - next to all of the state's other items associated with the same rule. This - bug affected only the `.output' file and not the generated parser source - code. - -** --report-file=FILE is a new option to override the default `.output' file - name. - -** The `=' that used to be required in the following directives is now - deprecated: - - %file-prefix "parser" - %name-prefix "c_" - %output "parser.c" - -** An Alternative to `%{...%}' -- `%code QUALIFIER {CODE}' - - Bison 2.3a provided a new set of directives as a more flexible alternative to - the traditional Yacc prologue blocks. Those have now been consolidated into - a single %code directive with an optional qualifier field, which identifies - the purpose of the code and thus the location(s) where Bison should generate - it: - - 1. `%code {CODE}' replaces `%after-header {CODE}' - 2. `%code requires {CODE}' replaces `%start-header {CODE}' - 3. `%code provides {CODE}' replaces `%end-header {CODE}' - 4. `%code top {CODE}' replaces `%before-header {CODE}' - - See the %code entries in section `Bison Declaration Summary' in the Bison - manual for a summary of the new functionality. See the new section `Prologue - Alternatives' for a detailed discussion including the advantages of %code - over the traditional Yacc prologues. - - The prologue alternatives are experimental. More user feedback will help to - determine whether they should become permanent features. - -** Revised warning: unset or unused mid-rule values - - Since Bison 2.2, Bison has warned about mid-rule values that are set but not - used within any of the actions of the parent rule. For example, Bison warns - about unused $2 in: - - exp: '1' { $$ = 1; } '+' exp { $$ = $1 + $4; }; - - Now, Bison also warns about mid-rule values that are used but not set. For - example, Bison warns about unset $$ in the mid-rule action in: - - exp: '1' { $1 = 1; } '+' exp { $$ = $2 + $4; }; - - However, Bison now disables both of these warnings by default since they - sometimes prove to be false alarms in existing grammars employing the Yacc - constructs $0 or $-N (where N is some positive integer). - - To enable these warnings, specify the option `--warnings=midrule-values' or - `-W', which is a synonym for `--warnings=all'. - -** Default %destructor or %printer with `<*>' or `<>' - - Bison now recognizes two separate kinds of default %destructor's and - %printer's: - - 1. Place `<*>' in a %destructor/%printer symbol list to define a default - %destructor/%printer for all grammar symbols for which you have formally - declared semantic type tags. - - 2. Place `<>' in a %destructor/%printer symbol list to define a default - %destructor/%printer for all grammar symbols without declared semantic - type tags. - - Bison no longer supports the `%symbol-default' notation from Bison 2.3a. - `<*>' and `<>' combined achieve the same effect with one exception: Bison no - longer applies any %destructor to a mid-rule value if that mid-rule value is - not actually ever referenced using either $$ or $n in a semantic action. - - The default %destructor's and %printer's are experimental. More user - feedback will help to determine whether they should become permanent - features. - - See the section `Freeing Discarded Symbols' in the Bison manual for further - details. - -** %left, %right, and %nonassoc can now declare token numbers. This is required - by POSIX. However, see the end of section `Operator Precedence' in the Bison - manual for a caveat concerning the treatment of literal strings. - -** The nonfunctional --no-parser, -n, and %no-parser options have been - completely removed from Bison. - -* Changes in version 2.3a, 2006-09-13: - -** Instead of %union, you can define and use your own union type - YYSTYPE if your grammar contains at least one <type> tag. - Your YYSTYPE need not be a macro; it can be a typedef. - This change is for compatibility with other Yacc implementations, - and is required by POSIX. - -** Locations columns and lines start at 1. - In accordance with the GNU Coding Standards and Emacs. - -** You may now declare per-type and default %destructor's and %printer's: - - For example: - - %union { char *string; } - %token <string> STRING1 - %token <string> STRING2 - %type <string> string1 - %type <string> string2 - %union { char character; } - %token <character> CHR - %type <character> chr - %destructor { free ($$); } %symbol-default - %destructor { free ($$); printf ("%d", @$.first_line); } STRING1 string1 - %destructor { } <character> - - guarantees that, when the parser discards any user-defined symbol that has a - semantic type tag other than `<character>', it passes its semantic value to - `free'. However, when the parser discards a `STRING1' or a `string1', it - also prints its line number to `stdout'. It performs only the second - `%destructor' in this case, so it invokes `free' only once. - - [Although we failed to mention this here in the 2.3a release, the default - %destructor's and %printer's were experimental, and they were rewritten in - future versions.] - -** Except for LALR(1) parsers in C with POSIX Yacc emulation enabled (with `-y', - `--yacc', or `%yacc'), Bison no longer generates #define statements for - associating token numbers with token names. Removing the #define statements - helps to sanitize the global namespace during preprocessing, but POSIX Yacc - requires them. Bison still generates an enum for token names in all cases. - -** Handling of traditional Yacc prologue blocks is now more consistent but - potentially incompatible with previous releases of Bison. - - As before, you declare prologue blocks in your grammar file with the - `%{ ... %}' syntax. To generate the pre-prologue, Bison concatenates all - prologue blocks that you've declared before the first %union. To generate - the post-prologue, Bison concatenates all prologue blocks that you've - declared after the first %union. - - Previous releases of Bison inserted the pre-prologue into both the header - file and the code file in all cases except for LALR(1) parsers in C. In the - latter case, Bison inserted it only into the code file. For parsers in C++, - the point of insertion was before any token definitions (which associate - token numbers with names). For parsers in C, the point of insertion was - after the token definitions. - - Now, Bison never inserts the pre-prologue into the header file. In the code - file, it always inserts it before the token definitions. - -** Bison now provides a more flexible alternative to the traditional Yacc - prologue blocks: %before-header, %start-header, %end-header, and - %after-header. - - For example, the following declaration order in the grammar file reflects the - order in which Bison will output these code blocks. However, you are free to - declare these code blocks in your grammar file in whatever order is most - convenient for you: - - %before-header { - /* Bison treats this block like a pre-prologue block: it inserts it into - * the code file before the contents of the header file. It does *not* - * insert it into the header file. This is a good place to put - * #include's that you want at the top of your code file. A common - * example is `#include "system.h"'. */ - } - %start-header { - /* Bison inserts this block into both the header file and the code file. - * In both files, the point of insertion is before any Bison-generated - * token, semantic type, location type, and class definitions. This is a - * good place to define %union dependencies, for example. */ - } - %union { - /* Unlike the traditional Yacc prologue blocks, the output order for the - * new %*-header blocks is not affected by their declaration position - * relative to any %union in the grammar file. */ - } - %end-header { - /* Bison inserts this block into both the header file and the code file. - * In both files, the point of insertion is after the Bison-generated - * definitions. This is a good place to declare or define public - * functions or data structures that depend on the Bison-generated - * definitions. */ - } - %after-header { - /* Bison treats this block like a post-prologue block: it inserts it into - * the code file after the contents of the header file. It does *not* - * insert it into the header file. This is a good place to declare or - * define internal functions or data structures that depend on the - * Bison-generated definitions. */ - } - - If you have multiple occurrences of any one of the above declarations, Bison - will concatenate the contents in declaration order. - - [Although we failed to mention this here in the 2.3a release, the prologue - alternatives were experimental, and they were rewritten in future versions.] - -** The option `--report=look-ahead' has been changed to `--report=lookahead'. - The old spelling still works, but is not documented and may be removed - in a future release. - -* Changes in version 2.3, 2006-06-05: - -** GLR grammars should now use `YYRECOVERING ()' instead of `YYRECOVERING', - for compatibility with LALR(1) grammars. - -** It is now documented that any definition of YYSTYPE or YYLTYPE should - be to a type name that does not contain parentheses or brackets. - -* Changes in version 2.2, 2006-05-19: - -** The distribution terms for all Bison-generated parsers now permit - using the parsers in nonfree programs. Previously, this permission - was granted only for Bison-generated LALR(1) parsers in C. - -** %name-prefix changes the namespace name in C++ outputs. - -** The C++ parsers export their token_type. - -** Bison now allows multiple %union declarations, and concatenates - their contents together. - -** New warning: unused values - Right-hand side symbols whose values are not used are reported, - if the symbols have destructors. For instance: - - exp: exp "?" exp ":" exp { $1 ? $1 : $3; } - | exp "+" exp - ; - - will trigger a warning about $$ and $5 in the first rule, and $3 in - the second ($1 is copied to $$ by the default rule). This example - most likely contains three errors, and could be rewritten as: - - exp: exp "?" exp ":" exp - { $$ = $1 ? $3 : $5; free ($1 ? $5 : $3); free ($1); } - | exp "+" exp - { $$ = $1 ? $1 : $3; if ($1) free ($3); } - ; - - However, if the original actions were really intended, memory leaks - and all, the warnings can be suppressed by letting Bison believe the - values are used, e.g.: - - exp: exp "?" exp ":" exp { $1 ? $1 : $3; (void) ($$, $5); } - | exp "+" exp { $$ = $1; (void) $3; } - ; - - If there are mid-rule actions, the warning is issued if no action - uses it. The following triggers no warning: $1 and $3 are used. - - exp: exp { push ($1); } '+' exp { push ($3); sum (); }; - - The warning is intended to help catching lost values and memory leaks. - If a value is ignored, its associated memory typically is not reclaimed. - -** %destructor vs. YYABORT, YYACCEPT, and YYERROR. - Destructors are now called when user code invokes YYABORT, YYACCEPT, - and YYERROR, for all objects on the stack, other than objects - corresponding to the right-hand side of the current rule. - -** %expect, %expect-rr - Incorrect numbers of expected conflicts are now actual errors, - instead of warnings. - -** GLR, YACC parsers. - The %parse-params are available in the destructors (and the - experimental printers) as per the documentation. - -** Bison now warns if it finds a stray `$' or `@' in an action. - -** %require "VERSION" - This specifies that the grammar file depends on features implemented - in Bison version VERSION or higher. - -** lalr1.cc: The token and value types are now class members. - The tokens were defined as free form enums and cpp macros. YYSTYPE - was defined as a free form union. They are now class members: - tokens are enumerations of the `yy::parser::token' struct, and the - semantic values have the `yy::parser::semantic_type' type. - - If you do not want or can update to this scheme, the directive - `%define "global_tokens_and_yystype" "1"' triggers the global - definition of tokens and YYSTYPE. This change is suitable both - for previous releases of Bison, and this one. - - If you wish to update, then make sure older version of Bison will - fail using `%require "2.2"'. - -** DJGPP support added. - -* Changes in version 2.1, 2005-09-16: - -** The C++ lalr1.cc skeleton supports %lex-param. - -** Bison-generated parsers now support the translation of diagnostics like - "syntax error" into languages other than English. The default - language is still English. For details, please see the new - Internationalization section of the Bison manual. Software - distributors should also see the new PACKAGING file. Thanks to - Bruno Haible for this new feature. - -** Wording in the Bison-generated parsers has been changed slightly to - simplify translation. In particular, the message "memory exhausted" - has replaced "parser stack overflow", as the old message was not - always accurate for modern Bison-generated parsers. - -** Destructors are now called when the parser aborts, for all symbols left - behind on the stack. Also, the start symbol is now destroyed after a - successful parse. In both cases, the behavior was formerly inconsistent. - -** When generating verbose diagnostics, Bison-generated parsers no longer - quote the literal strings associated with tokens. For example, for - a syntax error associated with '%token NUM "number"' they might - print 'syntax error, unexpected number' instead of 'syntax error, - unexpected "number"'. - -* Changes in version 2.0, 2004-12-25: - -** Possibly-incompatible changes - - - 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. - - - 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. - - - Semicolon changes: - . Stray semicolons are no longer allowed at the start of a grammar. - . Semicolons are now required after in-grammar declarations. - - - 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. - - - NUL bytes are no longer allowed in Bison string literals, unfortunately. - -** New features - - - 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. - - - 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'. - [However, this was changed back after 2.3.] - - - Experimental %destructor support has been added to lalr1.cc. - - - New configure option --disable-yacc, to disable installation of the - yacc command and -ly library introduced in 1.875 for POSIX conformance. - -** Bug fixes - - - 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: - -** The documentation license has been upgraded to version 1.2 - of the GNU Free Documentation License. - -** syntax error processing - - - In Yacc-style parsers YYLLOC_DEFAULT is now used to compute error - locations too. This fixes bugs in error-location computation. - - - %destructor - It is now possible to reclaim the memory associated to symbols - discarded during error recovery. This feature is still experimental. - - - %error-verbose - This new directive is preferred over YYERROR_VERBOSE. - - - #defining yyerror to steal internal variables is discouraged. - It is not guaranteed to work forever. - -** POSIX conformance - - - Semicolons are once again optional at the end of grammar rules. - This reverts to the behavior of Bison 1.33 and earlier, and improves - compatibility with Yacc. - - - `parse error' -> `syntax error' - Bison now uniformly uses the term `syntax error'; formerly, the code - and manual sometimes used the term `parse error' instead. POSIX - requires `syntax error' in diagnostics, and it was thought better to - be consistent. - - - The documentation now emphasizes that yylex and yyerror must be - declared before use. C99 requires this. - - - Bison now parses C99 lexical constructs like UCNs and - backslash-newline within C escape sequences, as POSIX 1003.1-2001 requires. - - - File names are properly escaped in C output. E.g., foo\bar.y is - output as "foo\\bar.y". - - - Yacc command and library now available - The Bison distribution now installs a `yacc' command, as POSIX requires. - Also, Bison now installs a small library liby.a containing - implementations of Yacc-compatible yyerror and main functions. - This library is normally not useful, but POSIX requires it. - - - Type clashes now generate warnings, not errors. - - - If the user does not define YYSTYPE as a macro, Bison now declares it - using typedef instead of defining it as a macro. - For consistency, YYLTYPE is also declared instead of defined. - -** Other compatibility issues - - - %union directives can now have a tag before the `{', e.g., the - directive `%union foo {...}' now generates the C code - `typedef union foo { ... } YYSTYPE;'; this is for Yacc compatibility. - The default union tag is `YYSTYPE', for compatibility with Solaris 9 Yacc. - For consistency, YYLTYPE's struct tag is now `YYLTYPE' not `yyltype'. - This is for compatibility with both Yacc and Bison 1.35. - - - `;' is output before the terminating `}' of an action, for - compatibility with Bison 1.35. - - - Bison now uses a Yacc-style format for conflict reports, e.g., - `conflicts: 2 shift/reduce, 1 reduce/reduce'. - - - `yystype' and `yyltype' are now obsolescent macros instead of being - typedefs or tags; they are no longer documented and are planned to be - withdrawn in a future release. - -** GLR parser notes - - - GLR and inline - Users of Bison have to decide how they handle the portability of the - C keyword `inline'. - - - `parsing stack overflow...' -> `parser stack overflow' - GLR parsers now report `parser stack overflow' as per the Bison manual. - -** Bison now warns if it detects conflicting outputs to the same file, - e.g., it generates a warning for `bison -d -o foo.h foo.y' since - that command outputs both code and header to foo.h. - -** #line in output files - - --no-line works properly. - -** Bison can no longer be built by a K&R C compiler; it requires C89 or - later to be built. This change originally took place a few versions - ago, but nobody noticed until we recently asked someone to try - building Bison with a K&R C compiler. - -* Changes in version 1.75, 2002-10-14: - -** Bison should now work on 64-bit hosts. - -** Indonesian translation thanks to Tedi Heriyanto. - -** GLR parsers - Fix spurious parse errors. - -** Pure parsers - Some people redefine yyerror to steal yyparse' private variables. - Reenable this trick until an official feature replaces it. - -** Type Clashes - In agreement with POSIX and with other Yaccs, leaving a default - action is valid when $$ is untyped, and $1 typed: - - untyped: ... typed; - - but the converse remains an error: - - typed: ... untyped; - -** Values of mid-rule actions - The following code: - - foo: { ... } { $$ = $1; } ... - - was incorrectly rejected: $1 is defined in the second mid-rule - action, and is equal to the $$ of the first mid-rule action. - -* Changes in version 1.50, 2002-10-04: - -** GLR parsing - The declaration - %glr-parser - causes Bison to produce a Generalized LR (GLR) parser, capable of handling - almost any context-free grammar, ambiguous or not. The new declarations - %dprec and %merge on grammar rules allow parse-time resolution of - ambiguities. Contributed by Paul Hilfinger. - - Unfortunately Bison 1.50 does not work properly on 64-bit hosts - like the Alpha, so please stick to 32-bit hosts for now. - -** Output Directory - When not in Yacc compatibility mode, when the output file was not - specified, running `bison foo/bar.y' created `foo/bar.c'. It - now creates `bar.c'. - -** Undefined token - The undefined token was systematically mapped to 2 which prevented - the use of 2 by the user. This is no longer the case. - -** Unknown token numbers - If yylex returned an out of range value, yyparse could die. This is - no longer the case. - -** Error token - According to POSIX, the error token must be 256. - Bison extends this requirement by making it a preference: *if* the - user specified that one of her tokens is numbered 256, then error - will be mapped onto another number. - -** Verbose error messages - They no longer report `..., expecting error or...' for states where - error recovery is possible. - -** End token - Defaults to `$end' instead of `$'. - -** Error recovery now conforms to documentation and to POSIX - When a Bison-generated parser encounters a syntax error, it now pops - the stack until it finds a state that allows shifting the error - token. Formerly, it popped the stack until it found a state that - 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) - <http://lists.gnu.org/archive/html/bug-bison/2002-05/msg00038.html>. - -** Traces - Popped tokens and nonterminals are now reported. - -** Larger grammars - Larger grammars are now supported (larger token numbers, larger grammar - size (= sum of the LHS and RHS lengths), larger LALR tables). - Formerly, many of these numbers ran afoul of 16-bit limits; - now these limits are 32 bits on most hosts. - -** Explicit initial rule - Bison used to play hacks with the initial rule, which the user does - not write. It is now explicit, and visible in the reports and - graphs as rule 0. - -** Useless rules - Before, Bison reported the useless rules, but, although not used, - included them in the parsers. They are now actually removed. - -** Useless rules, useless nonterminals - They are now reported, as a warning, with their locations. - -** Rules never reduced - Rules that can never be reduced because of conflicts are now - reported. - -** Incorrect `Token not used' - On a grammar such as - - %token useless useful - %% - exp: '0' %prec useful; - - where a token was used to set the precedence of the last rule, - bison reported both `useful' and `useless' as useless tokens. - -** Revert the C++ namespace changes introduced in 1.31 - as they caused too many portability hassles. - -** Default locations - By an accident of design, the default computation of @$ was - performed after another default computation was performed: @$ = @1. - The latter is now removed: YYLLOC_DEFAULT is fully responsible of - the computation of @$. - -** Token end-of-file - The token end of file may be specified by the user, in which case, - the user symbol is used in the reports, the graphs, and the verbose - error messages instead of `$end', which remains being the default. - For instance - %token MYEOF 0 - or - %token MYEOF 0 "end of file" - -** Semantic parser - This old option, which has been broken for ages, is removed. - -** New translations - Brazilian Portuguese, thanks to Alexandre Folle de Menezes. - Croatian, thanks to Denis Lackovic. - -** Incorrect token definitions - When given `%token 'a' "A"', Bison used to output `#define 'a' 65'. - -** Token definitions as enums - Tokens are output both as the traditional #define's, and, provided - the compiler supports ANSI C or is a C++ compiler, as enums. - This lets debuggers display names instead of integers. - -** Reports - In addition to --verbose, bison supports --report=THINGS, which - produces additional information: - - itemset - complete the core item sets with their closure - - lookahead [changed to `look-ahead' in 1.875e through 2.3, but changed back] - explicitly associate lookahead tokens to items - - solved - describe shift/reduce conflicts solving. - Bison used to systematically output this information on top of - the report. Solved conflicts are now attached to their states. - -** Type clashes - Previous versions don't complain when there is a type clash on - the default action if the rule has a mid-rule action, such as in: - - %type <foo> bar - %% - bar: '0' {} '0'; - - This is fixed. - -** GNU M4 is now required when using Bison. - -* Changes in version 1.35, 2002-03-25: - -** C Skeleton - Some projects use Bison's C parser with C++ compilers, and define - YYSTYPE as a class. The recent adjustment of C parsers for data - alignment and 64 bit architectures made this impossible. - - Because for the time being no real solution for C++ parser - generation exists, kludges were implemented in the parser to - maintain this use. In the future, when Bison has C++ parsers, this - kludge will be disabled. - - This kludge also addresses some C++ problems when the stack was - extended. - -* Changes in version 1.34, 2002-03-12: - -** File name clashes are detected - $ bison foo.y -d -o foo.x - fatal error: header and parser would both be named `foo.x' - -** A missing `;' at the end of a rule triggers a warning - In accordance with POSIX, and in agreement with other - Yacc implementations, Bison will mandate this semicolon in the near - future. This eases the implementation of a Bison parser of Bison - grammars by making this grammar LALR(1) instead of LR(2). To - facilitate the transition, this release introduces a warning. - -** Revert the C++ namespace changes introduced in 1.31, as they caused too - many portability hassles. - -** DJGPP support added. - -** Fix test suite portability problems. - -* Changes in version 1.33, 2002-02-07: - -** Fix C++ issues - Groff could not be compiled for the definition of size_t was lacking - under some conditions. - -** Catch invalid @n - As is done with $n. - -* Changes in version 1.32, 2002-01-23: - -** Fix Yacc output file names - -** Portability fixes - -** Italian, Dutch translations - -* Changes in version 1.31, 2002-01-14: - -** Many Bug Fixes - -** GNU Gettext and %expect - GNU Gettext asserts 10 s/r conflicts, but there are 7. Now that - Bison dies on incorrect %expectations, we fear there will be - too many bug reports for Gettext, so _for the time being_, %expect - does not trigger an error when the input file is named `plural.y'. - -** Use of alloca in parsers - If YYSTACK_USE_ALLOCA is defined to 0, then the parsers will use - malloc exclusively. Since 1.29, but was not NEWS'ed. - - alloca is used only when compiled with GCC, to avoid portability - problems as on AIX. - -** yyparse now returns 2 if memory is exhausted; formerly it dumped core. - -** When the generated parser lacks debugging code, YYDEBUG is now 0 - (as POSIX requires) instead of being undefined. - -** User Actions - Bison has always permitted actions such as { $$ = $1 }: it adds the - ending semicolon. Now if in Yacc compatibility mode, the semicolon - is no longer output: one has to write { $$ = $1; }. - -** Better C++ compliance - The output parsers try to respect C++ namespaces. - [This turned out to be a failed experiment, and it was reverted later.] - -** Reduced Grammars - Fixed bugs when reporting useless nonterminals. - -** 64 bit hosts - The parsers work properly on 64 bit hosts. - -** Error messages - Some calls to strerror resulted in scrambled or missing error messages. - -** %expect - When the number of shift/reduce conflicts is correct, don't issue - any warning. - -** The verbose report includes the rule line numbers. - -** Rule line numbers are fixed in traces. - -** Swedish translation - -** Parse errors - Verbose parse error messages from the parsers are better looking. - Before: parse error: unexpected `'/'', expecting `"number"' or `'-'' or `'('' - Now: parse error: unexpected '/', expecting "number" or '-' or '(' - -** Fixed parser memory leaks. - When the generated parser was using malloc to extend its stacks, the - previous allocations were not freed. - -** Fixed verbose output file. - Some newlines were missing. - Some conflicts in state descriptions were missing. - -** Fixed conflict report. - Option -v was needed to get the result. - -** %expect - Was not used. - Mismatches are errors, not warnings. - -** Fixed incorrect processing of some invalid input. - -** Fixed CPP guards: 9foo.h uses BISON_9FOO_H instead of 9FOO_H. - -** Fixed some typos in the documentation. - -** %token MY_EOF 0 is supported. - Before, MY_EOF was silently renumbered as 257. - -** doc/refcard.tex is updated. - -** %output, %file-prefix, %name-prefix. - New. - -** --output - New, aliasing `--output-file'. - -* Changes in version 1.30, 2001-10-26: - -** `--defines' and `--graph' have now an optional argument which is the - output file name. `-d' and `-g' do not change; they do not take any - argument. - -** `%source_extension' and `%header_extension' are removed, failed - experiment. - -** Portability fixes. - -* Changes in version 1.29, 2001-09-07: - -** The output file does not define const, as this caused problems when used - with common autoconfiguration schemes. If you still use ancient compilers - that lack const, compile with the equivalent of the C compiler option - `-Dconst='. autoconf's AC_C_CONST macro provides one way to do this. - -** Added `-g' and `--graph'. - -** The Bison manual is now distributed under the terms of the GNU FDL. - -** The input and the output files has automatically a similar extension. - -** Russian translation added. - -** NLS support updated; should hopefully be less troublesome. - -** Added the old Bison reference card. - -** Added `--locations' and `%locations'. - -** Added `-S' and `--skeleton'. - -** `%raw', `-r', `--raw' is disabled. - -** Special characters are escaped when output. This solves the problems - of the #line lines with path names including backslashes. - -** New directives. - `%yacc', `%fixed_output_files', `%defines', `%no_parser', `%verbose', - `%debug', `%source_extension' and `%header_extension'. - -** @$ - Automatic location tracking. - -* Changes in version 1.28, 1999-07-06: - -** Should compile better now with K&R compilers. - -** Added NLS. - -** Fixed a problem with escaping the double quote character. - -** There is now a FAQ. - -* Changes in version 1.27: - -** The make rule which prevented bison.simple from being created on - some systems has been fixed. - -* Changes in version 1.26: - -** Bison now uses automake. - -** New mailing lists: <bug-bison@gnu.org> and <help-bison@gnu.org>. - -** Token numbers now start at 257 as previously documented, not 258. - -** Bison honors the TMPDIR environment variable. - -** A couple of buffer overruns have been fixed. - -** Problems when closing files should now be reported. - -** Generated parsers should now work even on operating systems which do - not provide alloca(). - -* Changes in version 1.25, 1995-10-16: - -** Errors in the input grammar are not fatal; Bison keeps reading -the grammar file, and reports all the errors found in it. - -** Tokens can now be specified as multiple-character strings: for -example, you could use "<=" for a token which looks like <=, instead -of chosing a name like LESSEQ. - -** The %token_table declaration says to write a table of tokens (names -and numbers) into the parser file. The yylex function can use this -table to recognize multiple-character string tokens, or for other -purposes. - -** The %no_lines declaration says not to generate any #line preprocessor -directives in the parser file. - -** The %raw declaration says to use internal Bison token numbers, not -Yacc-compatible token numbers, when token names are defined as macros. - -** The --no-parser option produces the parser tables without including -the parser engine; a project can now use its own parser engine. -The actions go into a separate file called NAME.act, in the form of -a switch statement body. - -* Changes in version 1.23: - -The user can define YYPARSE_PARAM as the name of an argument to be -passed into yyparse. The argument should have type void *. It should -actually point to an object. Grammar actions can access the variable -by casting it to the proper pointer type. - -Line numbers in output file corrected. - -* Changes in version 1.22: - ---help option added. - -* Changes in version 1.20: - -Output file does not redefine const for C++. - -Local Variables: -mode: outline -End: - ------ - -Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, -2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc. - -This file is part of Bison, the GNU Compiler Compiler. - -This program is free software: you can redistribute it and/or modify -it under the terms of the GNU General Public License as published by -the Free Software Foundation, either version 3 of the License, or -(at your option) any later version. - -This program is distributed in the hope that it will be useful, -but WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -GNU General Public License for more details. - -You should have received a copy of the GNU General Public License -along with this program. If not, see <http://www.gnu.org/licenses/>. |