pkgsrc/devel/bison/PLIST

87 lines
3.1 KiB
Text
Raw Normal View History

@comment $NetBSD: PLIST,v 1.22 2011/08/06 17:15:43 wiz Exp $
1998-03-20 23:45:15 +01:00
bin/bison
info/bison.info
lib/liby.a
man/man1/bison.1
share/aclocal/bison-i18n.m4
share/bison/README
Update to 2.4: 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.
2008-11-07 13:32:32 +01:00
share/bison/bison.m4
share/bison/c++-skel.m4
share/bison/c++.m4
Update to 2.4: 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.
2008-11-07 13:32:32 +01:00
share/bison/c-skel.m4
share/bison/c.m4
share/bison/glr.c
Update to 2.2: * 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.
2006-05-30 21:25:23 +02:00
share/bison/glr.cc
Update to 2.4: 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.
2008-11-07 13:32:32 +01:00
share/bison/java-skel.m4
share/bison/java.m4
share/bison/lalr1.cc
Update to 2.4: 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.
2008-11-07 13:32:32 +01:00
share/bison/lalr1.java
Update to 2.2: * 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.
2006-05-30 21:25:23 +02:00
share/bison/location.cc
Update to 2.4: 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.
2008-11-07 13:32:32 +01:00
share/bison/m4sugar/foreach.m4
share/bison/m4sugar/m4sugar.m4
Update to 2.4: 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.
2008-11-07 13:32:32 +01:00
share/bison/xslt/bison.xsl
share/bison/xslt/xml2dot.xsl
share/bison/xslt/xml2text.xsl
share/bison/xslt/xml2xhtml.xsl
share/bison/yacc.c
Update to 2.4.2: * Changes in version 2.4.2 (2010-03-20): ** Some portability problems that resulted in failures and livelocks in the test suite on some versions of at least Solaris, AIX, HP-UX, RHEL4, and Tru64 have been addressed. As a result, fatal Bison errors should no longer cause M4 to report a broken pipe on the affected platforms. ** `%prec IDENTIFIER' requires IDENTIFIER to be defined separately. POSIX specifies that an error be reported for any identifier that does not appear on the LHS of a grammar rule and that is not defined by %token, %left, %right, or %nonassoc. Bison 2.3b and later lost this error report for the case when an identifier appears only after a %prec directive. It is now restored. However, for backward compatibility with recent Bison releases, it is only a warning for now. In Bison 2.5 and later, it will return to being an error. ** Detection of GNU M4 1.4.6 or newer during configure is improved. ** Warnings from gcc's -Wundef option about undefined YYENABLE_NLS, YYLTYPE_IS_TRIVIAL, and __STRICT_ANSI__ in C/C++ parsers are now avoided. ** %code is now a permanent feature. A traditional Yacc prologue directive is written in the form: %{CODE%} To provide a more flexible alternative, Bison 2.3b introduced the %code directive with the following forms for C/C++: %code {CODE} %code requires {CODE} %code provides {CODE} %code top {CODE} These forms are now considered permanent features of Bison. See the %code entries in the section "Bison Declaration Summary" in the Bison manual for a summary of their functionality. See the section "Prologue Alternatives" for a detailed discussion including the advantages of %code over the traditional Yacc prologue directive. Bison's Java feature as a whole including its current usage of %code is still considered experimental. ** YYFAIL is deprecated and will eventually be removed. YYFAIL has existed for many years as an undocumented feature of deterministic parsers in C generated by Bison. Previously, it was documented for Bison's experimental Java parsers. YYFAIL is no longer documented for Java parsers and is formally deprecated in both cases. Users are strongly encouraged to migrate to YYERROR, which is specified by POSIX. Like YYERROR, you can invoke YYFAIL from a semantic action in order to induce a syntax error. The most obvious difference from YYERROR is that YYFAIL will automatically invoke yyerror to report the syntax error so that you don't have to. However, there are several other subtle differences between YYERROR and YYFAIL, and YYFAIL suffers from inherent flaws when %error-verbose or `#define YYERROR_VERBOSE' is used. For a more detailed discussion, see: http://lists.gnu.org/archive/html/bison-patches/2009-12/msg00024.html The upcoming Bison 2.5 will remove YYFAIL from Java parsers, but deterministic parsers in C will continue to implement it. However, because YYFAIL is already flawed, it seems futile to try to make new Bison features compatible with it. Thus, during parser generation, Bison 2.5 will produce a warning whenever it discovers YYFAIL in a rule action. In a later release, YYFAIL will be disabled for %error-verbose and `#define YYERROR_VERBOSE'. Eventually, YYFAIL will be removed altogether. There exists at least one case where Bison 2.5's YYFAIL warning will be a false positive. Some projects add phony uses of YYFAIL and other Bison-defined macros for the sole purpose of suppressing C preprocessor warnings (from GCC cpp's -Wunused-macros, for example). To avoid Bison's future warning, such YYFAIL uses can be moved to the epilogue (that is, after the second `%%') in the Bison input file. In this release (2.4.2), Bison already generates its own code to suppress C preprocessor warnings for YYFAIL, so projects can remove their own phony uses of YYFAIL if compatibility with Bison releases prior to 2.4.2 is not necessary. ** Internationalization. Fix a regression introduced in Bison 2.4: Under some circumstances, message translations were not installed although supported by the host system.
2010-05-02 12:41:52 +02:00
share/locale/ast/LC_MESSAGES/bison-runtime.mo
share/locale/da/LC_MESSAGES/bison-runtime.mo
share/locale/da/LC_MESSAGES/bison.mo
share/locale/de/LC_MESSAGES/bison-runtime.mo
share/locale/de/LC_MESSAGES/bison.mo
share/locale/el/LC_MESSAGES/bison-runtime.mo
share/locale/el/LC_MESSAGES/bison.mo
Update to 2.5: * Changes in version 2.5 (2011-05-14): ** Grammar symbol names can now contain non-initial dashes: Consistently with directives (such as %error-verbose) and with %define variables (e.g. push-pull), grammar symbol names may contain dashes in any position except the beginning. This is a GNU extension over POSIX Yacc. Thus, use of this extension is reported by -Wyacc and rejected in Yacc mode (--yacc). ** Named references: Historically, Yacc and Bison have supported positional references ($n, $$) to allow access to symbol values from inside of semantic actions code. Starting from this version, Bison can also accept named references. When no ambiguity is possible, original symbol names may be used as named references: if_stmt : "if" cond_expr "then" then_stmt ';' { $if_stmt = mk_if_stmt($cond_expr, $then_stmt); } In the more common case, explicit names may be declared: stmt[res] : "if" expr[cond] "then" stmt[then] "else" stmt[else] ';' { $res = mk_if_stmt($cond, $then, $else); } Location information is also accessible using @name syntax. When accessing symbol names containing dots or dashes, explicit bracketing ($[sym.1]) must be used. These features are experimental in this version. More user feedback will help to stabilize them. ** IELR(1) and canonical LR(1): IELR(1) is a minimal LR(1) parser table generation algorithm. That is, given any context-free grammar, IELR(1) generates parser tables with the full language-recognition power of canonical LR(1) but with nearly the same number of parser states as LALR(1). This reduction in parser states is often an order of magnitude. More importantly, because canonical LR(1)'s extra parser states may contain duplicate conflicts in the case of non-LR(1) grammars, the number of conflicts for IELR(1) is often an order of magnitude less as well. This can significantly reduce the complexity of developing of a grammar. Bison can now generate IELR(1) and canonical LR(1) parser tables in place of its traditional LALR(1) parser tables, which remain the default. You can specify the type of parser tables in the grammar file with these directives: %define lr.type lalr %define lr.type ielr %define lr.type canonical-lr The default-reduction optimization in the parser tables can also be adjusted using `%define lr.default-reductions'. For details on both of these features, see the new section `Tuning LR' in the Bison manual. These features are experimental. More user feedback will help to stabilize them. ** LAC (Lookahead Correction) for syntax error handling: Canonical LR, IELR, and LALR can suffer from a couple of problems upon encountering a syntax error. First, the parser might perform additional parser stack reductions before discovering the syntax error. Such reductions can perform user semantic actions that are unexpected because they are based on an invalid token, and they cause error recovery to begin in a different syntactic context than the one in which the invalid token was encountered. Second, when verbose error messages are enabled (with %error-verbose or the obsolete `#define YYERROR_VERBOSE'), the expected token list in the syntax error message can both contain invalid tokens and omit valid tokens. The culprits for the above problems are %nonassoc, default reductions in inconsistent states, and parser state merging. Thus, IELR and LALR suffer the most. Canonical LR can suffer only if %nonassoc is used or if default reductions are enabled for inconsistent states. LAC is a new mechanism within the parsing algorithm that solves these problems for canonical LR, IELR, and LALR without sacrificing %nonassoc, default reductions, or state merging. When LAC is in use, canonical LR and IELR behave almost exactly the same for both syntactically acceptable and syntactically unacceptable input. While LALR still does not support the full language-recognition power of canonical LR and IELR, LAC at least enables LALR's syntax error handling to correctly reflect LALR's language-recognition power. Currently, LAC is only supported for deterministic parsers in C. You can enable LAC with the following directive: %define parse.lac full See the new section `LAC' in the Bison manual for additional details including a few caveats. LAC is an experimental feature. More user feedback will help to stabilize it. ** %define improvements: *** Can now be invoked via the command line: Each of these command-line options -D NAME[=VALUE] --define=NAME[=VALUE] -F NAME[=VALUE] --force-define=NAME[=VALUE] is equivalent to this grammar file declaration %define NAME ["VALUE"] except that the manner in which Bison processes multiple definitions for the same NAME differs. Most importantly, -F and --force-define quietly override %define, but -D and --define do not. For further details, see the section `Bison Options' in the Bison manual. *** Variables renamed: The following %define variables api.push_pull lr.keep_unreachable_states have been renamed to api.push-pull lr.keep-unreachable-states The old names are now deprecated but will be maintained indefinitely for backward compatibility. *** Values no longer need to be quoted in the grammar file: If a %define value is an identifier, it no longer needs to be placed within quotations marks. For example, %define api.push-pull "push" can be rewritten as %define api.push-pull push *** Unrecognized variables are now errors not warnings. *** Multiple invocations for any variable is now an error not a warning. ** Unrecognized %code qualifiers are now errors not warnings. ** Character literals not of length one: Previously, Bison quietly converted all character literals to length one. For example, without warning, Bison interpreted the operators in the following grammar to be the same token: exp: exp '++' | exp '+' exp ; Bison now warns when a character literal is not of length one. In some future release, Bison will start reporting an error instead. ** Destructor calls fixed for lookaheads altered in semantic actions: Previously for deterministic parsers in C, if a user semantic action altered yychar, the parser in some cases used the old yychar value to determine which destructor to call for the lookahead upon a syntax error or upon parser return. This bug has been fixed. ** C++ parsers use YYRHSLOC: Similarly to the C parsers, the C++ parsers now define the YYRHSLOC macro and use it in the default YYLLOC_DEFAULT. You are encouraged to use it. If, for instance, your location structure has `first' and `last' members, instead of # define YYLLOC_DEFAULT(Current, Rhs, N) \ do \ if (N) \ { \ (Current).first = (Rhs)[1].location.first; \ (Current).last = (Rhs)[N].location.last; \ } \ else \ { \ (Current).first = (Current).last = (Rhs)[0].location.last; \ } \ while (false) use: # define YYLLOC_DEFAULT(Current, Rhs, N) \ do \ if (N) \ { \ (Current).first = YYRHSLOC (Rhs, 1).first; \ (Current).last = YYRHSLOC (Rhs, N).last; \ } \ else \ { \ (Current).first = (Current).last = YYRHSLOC (Rhs, 0).last; \ } \ while (false) ** YYLLOC_DEFAULT in C++: The default implementation of YYLLOC_DEFAULT used to be issued in the header file. It is now output in the implementation file, after the user %code sections so that its #ifndef guard does not try to override the user's YYLLOC_DEFAULT if provided. ** YYFAIL now produces warnings and Java parsers no longer implement it: YYFAIL has existed for many years as an undocumented feature of deterministic parsers in C generated by Bison. More recently, it was a documented feature of Bison's experimental Java parsers. As promised in Bison 2.4.2's NEWS entry, any appearance of YYFAIL in a semantic action now produces a deprecation warning, and Java parsers no longer implement YYFAIL at all. For further details, including a discussion of how to suppress C preprocessor warnings about YYFAIL being unused, see the Bison 2.4.2 NEWS entry. ** Temporary hack for adding a semicolon to the user action: Previously, Bison appended a semicolon to every user action for reductions when the output language defaulted to C (specifically, when neither %yacc, %language, %skeleton, or equivalent command-line options were specified). This allowed actions such as exp: exp "+" exp { $$ = $1 + $3 }; instead of exp: exp "+" exp { $$ = $1 + $3; }; As a first step in removing this misfeature, Bison now issues a warning when it appends a semicolon. Moreover, in cases where Bison cannot easily determine whether a semicolon is needed (for example, an action ending with a cpp directive or a braced compound initializer), it no longer appends one. Thus, the C compiler might now complain about a missing semicolon where it did not before. Future releases of Bison will cease to append semicolons entirely. ** Verbose syntax error message fixes: When %error-verbose or the obsolete `#define YYERROR_VERBOSE' is specified, syntax error messages produced by the generated parser include the unexpected token as well as a list of expected tokens. The effect of %nonassoc on these verbose messages has been corrected in two ways, but a more complete fix requires LAC, described above: *** When %nonassoc is used, there can exist parser states that accept no tokens, and so the parser does not always require a lookahead token in order to detect a syntax error. Because no unexpected token or expected tokens can then be reported, the verbose syntax error message described above is suppressed, and the parser instead reports the simpler message, `syntax error'. Previously, this suppression was sometimes erroneously triggered by %nonassoc when a lookahead was actually required. Now verbose messages are suppressed only when all previous lookaheads have already been shifted or discarded. *** Previously, the list of expected tokens erroneously included tokens that would actually induce a syntax error because conflicts for them were resolved with %nonassoc in the current parser state. Such tokens are now properly omitted from the list. *** Expected token lists are still often wrong due to state merging (from LALR or IELR) and default reductions, which can both add invalid tokens and subtract valid tokens. Canonical LR almost completely fixes this problem by eliminating state merging and default reductions. However, there is one minor problem left even when using canonical LR and even after the fixes above. That is, if the resolution of a conflict with %nonassoc appears in a later parser state than the one at which some syntax error is discovered, the conflicted token is still erroneously included in the expected token list. Bison's new LAC implementation, described above, eliminates this problem and the need for canonical LR. However, LAC is still experimental and is disabled by default. ** Java skeleton fixes: *** A location handling bug has been fixed. *** The top element of each of the value stack and location stack is now cleared when popped so that it can be garbage collected. *** Parser traces now print the top element of the stack. ** -W/--warnings fixes: *** Bison now properly recognizes the `no-' versions of categories: For example, given the following command line, Bison now enables all warnings except warnings for incompatibilities with POSIX Yacc: bison -Wall,no-yacc gram.y *** Bison now treats S/R and R/R conflicts like other warnings: Previously, conflict reports were independent of Bison's normal warning system. Now, Bison recognizes the warning categories `conflicts-sr' and `conflicts-rr'. This change has important consequences for the -W and --warnings command-line options. For example: bison -Wno-conflicts-sr gram.y # S/R conflicts not reported bison -Wno-conflicts-rr gram.y # R/R conflicts not reported bison -Wnone gram.y # no conflicts are reported bison -Werror gram.y # any conflict is an error However, as before, if the %expect or %expect-rr directive is specified, an unexpected number of conflicts is an error, and an expected number of conflicts is not reported, so -W and --warning then have no effect on the conflict report. *** The `none' category no longer disables a preceding `error': For example, for the following command line, Bison now reports errors instead of warnings for incompatibilities with POSIX Yacc: bison -Werror,none,yacc gram.y *** The `none' category now disables all Bison warnings: Previously, the `none' category disabled only Bison warnings for which there existed a specific -W/--warning category. However, given the following command line, Bison is now guaranteed to suppress all warnings: bison -Wnone gram.y ** Precedence directives can now assign token number 0: Since Bison 2.3b, which restored the ability of precedence directives to assign token numbers, doing so for token number 0 has produced an assertion failure. For example: %left END 0 This bug has been fixed.
2011-07-12 16:12:13 +02:00
share/locale/eo/LC_MESSAGES/bison-runtime.mo
share/locale/es/LC_MESSAGES/bison-runtime.mo
share/locale/es/LC_MESSAGES/bison.mo
share/locale/et/LC_MESSAGES/bison-runtime.mo
share/locale/et/LC_MESSAGES/bison.mo
share/locale/fi/LC_MESSAGES/bison-runtime.mo
Update to 2.4.2: * Changes in version 2.4.2 (2010-03-20): ** Some portability problems that resulted in failures and livelocks in the test suite on some versions of at least Solaris, AIX, HP-UX, RHEL4, and Tru64 have been addressed. As a result, fatal Bison errors should no longer cause M4 to report a broken pipe on the affected platforms. ** `%prec IDENTIFIER' requires IDENTIFIER to be defined separately. POSIX specifies that an error be reported for any identifier that does not appear on the LHS of a grammar rule and that is not defined by %token, %left, %right, or %nonassoc. Bison 2.3b and later lost this error report for the case when an identifier appears only after a %prec directive. It is now restored. However, for backward compatibility with recent Bison releases, it is only a warning for now. In Bison 2.5 and later, it will return to being an error. ** Detection of GNU M4 1.4.6 or newer during configure is improved. ** Warnings from gcc's -Wundef option about undefined YYENABLE_NLS, YYLTYPE_IS_TRIVIAL, and __STRICT_ANSI__ in C/C++ parsers are now avoided. ** %code is now a permanent feature. A traditional Yacc prologue directive is written in the form: %{CODE%} To provide a more flexible alternative, Bison 2.3b introduced the %code directive with the following forms for C/C++: %code {CODE} %code requires {CODE} %code provides {CODE} %code top {CODE} These forms are now considered permanent features of Bison. See the %code entries in the section "Bison Declaration Summary" in the Bison manual for a summary of their functionality. See the section "Prologue Alternatives" for a detailed discussion including the advantages of %code over the traditional Yacc prologue directive. Bison's Java feature as a whole including its current usage of %code is still considered experimental. ** YYFAIL is deprecated and will eventually be removed. YYFAIL has existed for many years as an undocumented feature of deterministic parsers in C generated by Bison. Previously, it was documented for Bison's experimental Java parsers. YYFAIL is no longer documented for Java parsers and is formally deprecated in both cases. Users are strongly encouraged to migrate to YYERROR, which is specified by POSIX. Like YYERROR, you can invoke YYFAIL from a semantic action in order to induce a syntax error. The most obvious difference from YYERROR is that YYFAIL will automatically invoke yyerror to report the syntax error so that you don't have to. However, there are several other subtle differences between YYERROR and YYFAIL, and YYFAIL suffers from inherent flaws when %error-verbose or `#define YYERROR_VERBOSE' is used. For a more detailed discussion, see: http://lists.gnu.org/archive/html/bison-patches/2009-12/msg00024.html The upcoming Bison 2.5 will remove YYFAIL from Java parsers, but deterministic parsers in C will continue to implement it. However, because YYFAIL is already flawed, it seems futile to try to make new Bison features compatible with it. Thus, during parser generation, Bison 2.5 will produce a warning whenever it discovers YYFAIL in a rule action. In a later release, YYFAIL will be disabled for %error-verbose and `#define YYERROR_VERBOSE'. Eventually, YYFAIL will be removed altogether. There exists at least one case where Bison 2.5's YYFAIL warning will be a false positive. Some projects add phony uses of YYFAIL and other Bison-defined macros for the sole purpose of suppressing C preprocessor warnings (from GCC cpp's -Wunused-macros, for example). To avoid Bison's future warning, such YYFAIL uses can be moved to the epilogue (that is, after the second `%%') in the Bison input file. In this release (2.4.2), Bison already generates its own code to suppress C preprocessor warnings for YYFAIL, so projects can remove their own phony uses of YYFAIL if compatibility with Bison releases prior to 2.4.2 is not necessary. ** Internationalization. Fix a regression introduced in Bison 2.4: Under some circumstances, message translations were not installed although supported by the host system.
2010-05-02 12:41:52 +02:00
share/locale/fi/LC_MESSAGES/bison.mo
share/locale/fr/LC_MESSAGES/bison-runtime.mo
share/locale/fr/LC_MESSAGES/bison.mo
share/locale/ga/LC_MESSAGES/bison-runtime.mo
share/locale/ga/LC_MESSAGES/bison.mo
Update to 2.5: * Changes in version 2.5 (2011-05-14): ** Grammar symbol names can now contain non-initial dashes: Consistently with directives (such as %error-verbose) and with %define variables (e.g. push-pull), grammar symbol names may contain dashes in any position except the beginning. This is a GNU extension over POSIX Yacc. Thus, use of this extension is reported by -Wyacc and rejected in Yacc mode (--yacc). ** Named references: Historically, Yacc and Bison have supported positional references ($n, $$) to allow access to symbol values from inside of semantic actions code. Starting from this version, Bison can also accept named references. When no ambiguity is possible, original symbol names may be used as named references: if_stmt : "if" cond_expr "then" then_stmt ';' { $if_stmt = mk_if_stmt($cond_expr, $then_stmt); } In the more common case, explicit names may be declared: stmt[res] : "if" expr[cond] "then" stmt[then] "else" stmt[else] ';' { $res = mk_if_stmt($cond, $then, $else); } Location information is also accessible using @name syntax. When accessing symbol names containing dots or dashes, explicit bracketing ($[sym.1]) must be used. These features are experimental in this version. More user feedback will help to stabilize them. ** IELR(1) and canonical LR(1): IELR(1) is a minimal LR(1) parser table generation algorithm. That is, given any context-free grammar, IELR(1) generates parser tables with the full language-recognition power of canonical LR(1) but with nearly the same number of parser states as LALR(1). This reduction in parser states is often an order of magnitude. More importantly, because canonical LR(1)'s extra parser states may contain duplicate conflicts in the case of non-LR(1) grammars, the number of conflicts for IELR(1) is often an order of magnitude less as well. This can significantly reduce the complexity of developing of a grammar. Bison can now generate IELR(1) and canonical LR(1) parser tables in place of its traditional LALR(1) parser tables, which remain the default. You can specify the type of parser tables in the grammar file with these directives: %define lr.type lalr %define lr.type ielr %define lr.type canonical-lr The default-reduction optimization in the parser tables can also be adjusted using `%define lr.default-reductions'. For details on both of these features, see the new section `Tuning LR' in the Bison manual. These features are experimental. More user feedback will help to stabilize them. ** LAC (Lookahead Correction) for syntax error handling: Canonical LR, IELR, and LALR can suffer from a couple of problems upon encountering a syntax error. First, the parser might perform additional parser stack reductions before discovering the syntax error. Such reductions can perform user semantic actions that are unexpected because they are based on an invalid token, and they cause error recovery to begin in a different syntactic context than the one in which the invalid token was encountered. Second, when verbose error messages are enabled (with %error-verbose or the obsolete `#define YYERROR_VERBOSE'), the expected token list in the syntax error message can both contain invalid tokens and omit valid tokens. The culprits for the above problems are %nonassoc, default reductions in inconsistent states, and parser state merging. Thus, IELR and LALR suffer the most. Canonical LR can suffer only if %nonassoc is used or if default reductions are enabled for inconsistent states. LAC is a new mechanism within the parsing algorithm that solves these problems for canonical LR, IELR, and LALR without sacrificing %nonassoc, default reductions, or state merging. When LAC is in use, canonical LR and IELR behave almost exactly the same for both syntactically acceptable and syntactically unacceptable input. While LALR still does not support the full language-recognition power of canonical LR and IELR, LAC at least enables LALR's syntax error handling to correctly reflect LALR's language-recognition power. Currently, LAC is only supported for deterministic parsers in C. You can enable LAC with the following directive: %define parse.lac full See the new section `LAC' in the Bison manual for additional details including a few caveats. LAC is an experimental feature. More user feedback will help to stabilize it. ** %define improvements: *** Can now be invoked via the command line: Each of these command-line options -D NAME[=VALUE] --define=NAME[=VALUE] -F NAME[=VALUE] --force-define=NAME[=VALUE] is equivalent to this grammar file declaration %define NAME ["VALUE"] except that the manner in which Bison processes multiple definitions for the same NAME differs. Most importantly, -F and --force-define quietly override %define, but -D and --define do not. For further details, see the section `Bison Options' in the Bison manual. *** Variables renamed: The following %define variables api.push_pull lr.keep_unreachable_states have been renamed to api.push-pull lr.keep-unreachable-states The old names are now deprecated but will be maintained indefinitely for backward compatibility. *** Values no longer need to be quoted in the grammar file: If a %define value is an identifier, it no longer needs to be placed within quotations marks. For example, %define api.push-pull "push" can be rewritten as %define api.push-pull push *** Unrecognized variables are now errors not warnings. *** Multiple invocations for any variable is now an error not a warning. ** Unrecognized %code qualifiers are now errors not warnings. ** Character literals not of length one: Previously, Bison quietly converted all character literals to length one. For example, without warning, Bison interpreted the operators in the following grammar to be the same token: exp: exp '++' | exp '+' exp ; Bison now warns when a character literal is not of length one. In some future release, Bison will start reporting an error instead. ** Destructor calls fixed for lookaheads altered in semantic actions: Previously for deterministic parsers in C, if a user semantic action altered yychar, the parser in some cases used the old yychar value to determine which destructor to call for the lookahead upon a syntax error or upon parser return. This bug has been fixed. ** C++ parsers use YYRHSLOC: Similarly to the C parsers, the C++ parsers now define the YYRHSLOC macro and use it in the default YYLLOC_DEFAULT. You are encouraged to use it. If, for instance, your location structure has `first' and `last' members, instead of # define YYLLOC_DEFAULT(Current, Rhs, N) \ do \ if (N) \ { \ (Current).first = (Rhs)[1].location.first; \ (Current).last = (Rhs)[N].location.last; \ } \ else \ { \ (Current).first = (Current).last = (Rhs)[0].location.last; \ } \ while (false) use: # define YYLLOC_DEFAULT(Current, Rhs, N) \ do \ if (N) \ { \ (Current).first = YYRHSLOC (Rhs, 1).first; \ (Current).last = YYRHSLOC (Rhs, N).last; \ } \ else \ { \ (Current).first = (Current).last = YYRHSLOC (Rhs, 0).last; \ } \ while (false) ** YYLLOC_DEFAULT in C++: The default implementation of YYLLOC_DEFAULT used to be issued in the header file. It is now output in the implementation file, after the user %code sections so that its #ifndef guard does not try to override the user's YYLLOC_DEFAULT if provided. ** YYFAIL now produces warnings and Java parsers no longer implement it: YYFAIL has existed for many years as an undocumented feature of deterministic parsers in C generated by Bison. More recently, it was a documented feature of Bison's experimental Java parsers. As promised in Bison 2.4.2's NEWS entry, any appearance of YYFAIL in a semantic action now produces a deprecation warning, and Java parsers no longer implement YYFAIL at all. For further details, including a discussion of how to suppress C preprocessor warnings about YYFAIL being unused, see the Bison 2.4.2 NEWS entry. ** Temporary hack for adding a semicolon to the user action: Previously, Bison appended a semicolon to every user action for reductions when the output language defaulted to C (specifically, when neither %yacc, %language, %skeleton, or equivalent command-line options were specified). This allowed actions such as exp: exp "+" exp { $$ = $1 + $3 }; instead of exp: exp "+" exp { $$ = $1 + $3; }; As a first step in removing this misfeature, Bison now issues a warning when it appends a semicolon. Moreover, in cases where Bison cannot easily determine whether a semicolon is needed (for example, an action ending with a cpp directive or a braced compound initializer), it no longer appends one. Thus, the C compiler might now complain about a missing semicolon where it did not before. Future releases of Bison will cease to append semicolons entirely. ** Verbose syntax error message fixes: When %error-verbose or the obsolete `#define YYERROR_VERBOSE' is specified, syntax error messages produced by the generated parser include the unexpected token as well as a list of expected tokens. The effect of %nonassoc on these verbose messages has been corrected in two ways, but a more complete fix requires LAC, described above: *** When %nonassoc is used, there can exist parser states that accept no tokens, and so the parser does not always require a lookahead token in order to detect a syntax error. Because no unexpected token or expected tokens can then be reported, the verbose syntax error message described above is suppressed, and the parser instead reports the simpler message, `syntax error'. Previously, this suppression was sometimes erroneously triggered by %nonassoc when a lookahead was actually required. Now verbose messages are suppressed only when all previous lookaheads have already been shifted or discarded. *** Previously, the list of expected tokens erroneously included tokens that would actually induce a syntax error because conflicts for them were resolved with %nonassoc in the current parser state. Such tokens are now properly omitted from the list. *** Expected token lists are still often wrong due to state merging (from LALR or IELR) and default reductions, which can both add invalid tokens and subtract valid tokens. Canonical LR almost completely fixes this problem by eliminating state merging and default reductions. However, there is one minor problem left even when using canonical LR and even after the fixes above. That is, if the resolution of a conflict with %nonassoc appears in a later parser state than the one at which some syntax error is discovered, the conflicted token is still erroneously included in the expected token list. Bison's new LAC implementation, described above, eliminates this problem and the need for canonical LR. However, LAC is still experimental and is disabled by default. ** Java skeleton fixes: *** A location handling bug has been fixed. *** The top element of each of the value stack and location stack is now cleared when popped so that it can be garbage collected. *** Parser traces now print the top element of the stack. ** -W/--warnings fixes: *** Bison now properly recognizes the `no-' versions of categories: For example, given the following command line, Bison now enables all warnings except warnings for incompatibilities with POSIX Yacc: bison -Wall,no-yacc gram.y *** Bison now treats S/R and R/R conflicts like other warnings: Previously, conflict reports were independent of Bison's normal warning system. Now, Bison recognizes the warning categories `conflicts-sr' and `conflicts-rr'. This change has important consequences for the -W and --warnings command-line options. For example: bison -Wno-conflicts-sr gram.y # S/R conflicts not reported bison -Wno-conflicts-rr gram.y # R/R conflicts not reported bison -Wnone gram.y # no conflicts are reported bison -Werror gram.y # any conflict is an error However, as before, if the %expect or %expect-rr directive is specified, an unexpected number of conflicts is an error, and an expected number of conflicts is not reported, so -W and --warning then have no effect on the conflict report. *** The `none' category no longer disables a preceding `error': For example, for the following command line, Bison now reports errors instead of warnings for incompatibilities with POSIX Yacc: bison -Werror,none,yacc gram.y *** The `none' category now disables all Bison warnings: Previously, the `none' category disabled only Bison warnings for which there existed a specific -W/--warning category. However, given the following command line, Bison is now guaranteed to suppress all warnings: bison -Wnone gram.y ** Precedence directives can now assign token number 0: Since Bison 2.3b, which restored the ability of precedence directives to assign token numbers, doing so for token number 0 has produced an assertion failure. For example: %left END 0 This bug has been fixed.
2011-07-12 16:12:13 +02:00
share/locale/gl/LC_MESSAGES/bison-runtime.mo
share/locale/hr/LC_MESSAGES/bison-runtime.mo
share/locale/hr/LC_MESSAGES/bison.mo
Update to 2.5: * Changes in version 2.5 (2011-05-14): ** Grammar symbol names can now contain non-initial dashes: Consistently with directives (such as %error-verbose) and with %define variables (e.g. push-pull), grammar symbol names may contain dashes in any position except the beginning. This is a GNU extension over POSIX Yacc. Thus, use of this extension is reported by -Wyacc and rejected in Yacc mode (--yacc). ** Named references: Historically, Yacc and Bison have supported positional references ($n, $$) to allow access to symbol values from inside of semantic actions code. Starting from this version, Bison can also accept named references. When no ambiguity is possible, original symbol names may be used as named references: if_stmt : "if" cond_expr "then" then_stmt ';' { $if_stmt = mk_if_stmt($cond_expr, $then_stmt); } In the more common case, explicit names may be declared: stmt[res] : "if" expr[cond] "then" stmt[then] "else" stmt[else] ';' { $res = mk_if_stmt($cond, $then, $else); } Location information is also accessible using @name syntax. When accessing symbol names containing dots or dashes, explicit bracketing ($[sym.1]) must be used. These features are experimental in this version. More user feedback will help to stabilize them. ** IELR(1) and canonical LR(1): IELR(1) is a minimal LR(1) parser table generation algorithm. That is, given any context-free grammar, IELR(1) generates parser tables with the full language-recognition power of canonical LR(1) but with nearly the same number of parser states as LALR(1). This reduction in parser states is often an order of magnitude. More importantly, because canonical LR(1)'s extra parser states may contain duplicate conflicts in the case of non-LR(1) grammars, the number of conflicts for IELR(1) is often an order of magnitude less as well. This can significantly reduce the complexity of developing of a grammar. Bison can now generate IELR(1) and canonical LR(1) parser tables in place of its traditional LALR(1) parser tables, which remain the default. You can specify the type of parser tables in the grammar file with these directives: %define lr.type lalr %define lr.type ielr %define lr.type canonical-lr The default-reduction optimization in the parser tables can also be adjusted using `%define lr.default-reductions'. For details on both of these features, see the new section `Tuning LR' in the Bison manual. These features are experimental. More user feedback will help to stabilize them. ** LAC (Lookahead Correction) for syntax error handling: Canonical LR, IELR, and LALR can suffer from a couple of problems upon encountering a syntax error. First, the parser might perform additional parser stack reductions before discovering the syntax error. Such reductions can perform user semantic actions that are unexpected because they are based on an invalid token, and they cause error recovery to begin in a different syntactic context than the one in which the invalid token was encountered. Second, when verbose error messages are enabled (with %error-verbose or the obsolete `#define YYERROR_VERBOSE'), the expected token list in the syntax error message can both contain invalid tokens and omit valid tokens. The culprits for the above problems are %nonassoc, default reductions in inconsistent states, and parser state merging. Thus, IELR and LALR suffer the most. Canonical LR can suffer only if %nonassoc is used or if default reductions are enabled for inconsistent states. LAC is a new mechanism within the parsing algorithm that solves these problems for canonical LR, IELR, and LALR without sacrificing %nonassoc, default reductions, or state merging. When LAC is in use, canonical LR and IELR behave almost exactly the same for both syntactically acceptable and syntactically unacceptable input. While LALR still does not support the full language-recognition power of canonical LR and IELR, LAC at least enables LALR's syntax error handling to correctly reflect LALR's language-recognition power. Currently, LAC is only supported for deterministic parsers in C. You can enable LAC with the following directive: %define parse.lac full See the new section `LAC' in the Bison manual for additional details including a few caveats. LAC is an experimental feature. More user feedback will help to stabilize it. ** %define improvements: *** Can now be invoked via the command line: Each of these command-line options -D NAME[=VALUE] --define=NAME[=VALUE] -F NAME[=VALUE] --force-define=NAME[=VALUE] is equivalent to this grammar file declaration %define NAME ["VALUE"] except that the manner in which Bison processes multiple definitions for the same NAME differs. Most importantly, -F and --force-define quietly override %define, but -D and --define do not. For further details, see the section `Bison Options' in the Bison manual. *** Variables renamed: The following %define variables api.push_pull lr.keep_unreachable_states have been renamed to api.push-pull lr.keep-unreachable-states The old names are now deprecated but will be maintained indefinitely for backward compatibility. *** Values no longer need to be quoted in the grammar file: If a %define value is an identifier, it no longer needs to be placed within quotations marks. For example, %define api.push-pull "push" can be rewritten as %define api.push-pull push *** Unrecognized variables are now errors not warnings. *** Multiple invocations for any variable is now an error not a warning. ** Unrecognized %code qualifiers are now errors not warnings. ** Character literals not of length one: Previously, Bison quietly converted all character literals to length one. For example, without warning, Bison interpreted the operators in the following grammar to be the same token: exp: exp '++' | exp '+' exp ; Bison now warns when a character literal is not of length one. In some future release, Bison will start reporting an error instead. ** Destructor calls fixed for lookaheads altered in semantic actions: Previously for deterministic parsers in C, if a user semantic action altered yychar, the parser in some cases used the old yychar value to determine which destructor to call for the lookahead upon a syntax error or upon parser return. This bug has been fixed. ** C++ parsers use YYRHSLOC: Similarly to the C parsers, the C++ parsers now define the YYRHSLOC macro and use it in the default YYLLOC_DEFAULT. You are encouraged to use it. If, for instance, your location structure has `first' and `last' members, instead of # define YYLLOC_DEFAULT(Current, Rhs, N) \ do \ if (N) \ { \ (Current).first = (Rhs)[1].location.first; \ (Current).last = (Rhs)[N].location.last; \ } \ else \ { \ (Current).first = (Current).last = (Rhs)[0].location.last; \ } \ while (false) use: # define YYLLOC_DEFAULT(Current, Rhs, N) \ do \ if (N) \ { \ (Current).first = YYRHSLOC (Rhs, 1).first; \ (Current).last = YYRHSLOC (Rhs, N).last; \ } \ else \ { \ (Current).first = (Current).last = YYRHSLOC (Rhs, 0).last; \ } \ while (false) ** YYLLOC_DEFAULT in C++: The default implementation of YYLLOC_DEFAULT used to be issued in the header file. It is now output in the implementation file, after the user %code sections so that its #ifndef guard does not try to override the user's YYLLOC_DEFAULT if provided. ** YYFAIL now produces warnings and Java parsers no longer implement it: YYFAIL has existed for many years as an undocumented feature of deterministic parsers in C generated by Bison. More recently, it was a documented feature of Bison's experimental Java parsers. As promised in Bison 2.4.2's NEWS entry, any appearance of YYFAIL in a semantic action now produces a deprecation warning, and Java parsers no longer implement YYFAIL at all. For further details, including a discussion of how to suppress C preprocessor warnings about YYFAIL being unused, see the Bison 2.4.2 NEWS entry. ** Temporary hack for adding a semicolon to the user action: Previously, Bison appended a semicolon to every user action for reductions when the output language defaulted to C (specifically, when neither %yacc, %language, %skeleton, or equivalent command-line options were specified). This allowed actions such as exp: exp "+" exp { $$ = $1 + $3 }; instead of exp: exp "+" exp { $$ = $1 + $3; }; As a first step in removing this misfeature, Bison now issues a warning when it appends a semicolon. Moreover, in cases where Bison cannot easily determine whether a semicolon is needed (for example, an action ending with a cpp directive or a braced compound initializer), it no longer appends one. Thus, the C compiler might now complain about a missing semicolon where it did not before. Future releases of Bison will cease to append semicolons entirely. ** Verbose syntax error message fixes: When %error-verbose or the obsolete `#define YYERROR_VERBOSE' is specified, syntax error messages produced by the generated parser include the unexpected token as well as a list of expected tokens. The effect of %nonassoc on these verbose messages has been corrected in two ways, but a more complete fix requires LAC, described above: *** When %nonassoc is used, there can exist parser states that accept no tokens, and so the parser does not always require a lookahead token in order to detect a syntax error. Because no unexpected token or expected tokens can then be reported, the verbose syntax error message described above is suppressed, and the parser instead reports the simpler message, `syntax error'. Previously, this suppression was sometimes erroneously triggered by %nonassoc when a lookahead was actually required. Now verbose messages are suppressed only when all previous lookaheads have already been shifted or discarded. *** Previously, the list of expected tokens erroneously included tokens that would actually induce a syntax error because conflicts for them were resolved with %nonassoc in the current parser state. Such tokens are now properly omitted from the list. *** Expected token lists are still often wrong due to state merging (from LALR or IELR) and default reductions, which can both add invalid tokens and subtract valid tokens. Canonical LR almost completely fixes this problem by eliminating state merging and default reductions. However, there is one minor problem left even when using canonical LR and even after the fixes above. That is, if the resolution of a conflict with %nonassoc appears in a later parser state than the one at which some syntax error is discovered, the conflicted token is still erroneously included in the expected token list. Bison's new LAC implementation, described above, eliminates this problem and the need for canonical LR. However, LAC is still experimental and is disabled by default. ** Java skeleton fixes: *** A location handling bug has been fixed. *** The top element of each of the value stack and location stack is now cleared when popped so that it can be garbage collected. *** Parser traces now print the top element of the stack. ** -W/--warnings fixes: *** Bison now properly recognizes the `no-' versions of categories: For example, given the following command line, Bison now enables all warnings except warnings for incompatibilities with POSIX Yacc: bison -Wall,no-yacc gram.y *** Bison now treats S/R and R/R conflicts like other warnings: Previously, conflict reports were independent of Bison's normal warning system. Now, Bison recognizes the warning categories `conflicts-sr' and `conflicts-rr'. This change has important consequences for the -W and --warnings command-line options. For example: bison -Wno-conflicts-sr gram.y # S/R conflicts not reported bison -Wno-conflicts-rr gram.y # R/R conflicts not reported bison -Wnone gram.y # no conflicts are reported bison -Werror gram.y # any conflict is an error However, as before, if the %expect or %expect-rr directive is specified, an unexpected number of conflicts is an error, and an expected number of conflicts is not reported, so -W and --warning then have no effect on the conflict report. *** The `none' category no longer disables a preceding `error': For example, for the following command line, Bison now reports errors instead of warnings for incompatibilities with POSIX Yacc: bison -Werror,none,yacc gram.y *** The `none' category now disables all Bison warnings: Previously, the `none' category disabled only Bison warnings for which there existed a specific -W/--warning category. However, given the following command line, Bison is now guaranteed to suppress all warnings: bison -Wnone gram.y ** Precedence directives can now assign token number 0: Since Bison 2.3b, which restored the ability of precedence directives to assign token numbers, doing so for token number 0 has produced an assertion failure. For example: %left END 0 This bug has been fixed.
2011-07-12 16:12:13 +02:00
share/locale/hu/LC_MESSAGES/bison-runtime.mo
share/locale/id/LC_MESSAGES/bison-runtime.mo
share/locale/id/LC_MESSAGES/bison.mo
share/locale/it/LC_MESSAGES/bison-runtime.mo
share/locale/it/LC_MESSAGES/bison.mo
share/locale/ja/LC_MESSAGES/bison-runtime.mo
share/locale/ja/LC_MESSAGES/bison.mo
share/locale/ky/LC_MESSAGES/bison-runtime.mo
share/locale/lt/LC_MESSAGES/bison-runtime.mo
Update to 2.4.2: * Changes in version 2.4.2 (2010-03-20): ** Some portability problems that resulted in failures and livelocks in the test suite on some versions of at least Solaris, AIX, HP-UX, RHEL4, and Tru64 have been addressed. As a result, fatal Bison errors should no longer cause M4 to report a broken pipe on the affected platforms. ** `%prec IDENTIFIER' requires IDENTIFIER to be defined separately. POSIX specifies that an error be reported for any identifier that does not appear on the LHS of a grammar rule and that is not defined by %token, %left, %right, or %nonassoc. Bison 2.3b and later lost this error report for the case when an identifier appears only after a %prec directive. It is now restored. However, for backward compatibility with recent Bison releases, it is only a warning for now. In Bison 2.5 and later, it will return to being an error. ** Detection of GNU M4 1.4.6 or newer during configure is improved. ** Warnings from gcc's -Wundef option about undefined YYENABLE_NLS, YYLTYPE_IS_TRIVIAL, and __STRICT_ANSI__ in C/C++ parsers are now avoided. ** %code is now a permanent feature. A traditional Yacc prologue directive is written in the form: %{CODE%} To provide a more flexible alternative, Bison 2.3b introduced the %code directive with the following forms for C/C++: %code {CODE} %code requires {CODE} %code provides {CODE} %code top {CODE} These forms are now considered permanent features of Bison. See the %code entries in the section "Bison Declaration Summary" in the Bison manual for a summary of their functionality. See the section "Prologue Alternatives" for a detailed discussion including the advantages of %code over the traditional Yacc prologue directive. Bison's Java feature as a whole including its current usage of %code is still considered experimental. ** YYFAIL is deprecated and will eventually be removed. YYFAIL has existed for many years as an undocumented feature of deterministic parsers in C generated by Bison. Previously, it was documented for Bison's experimental Java parsers. YYFAIL is no longer documented for Java parsers and is formally deprecated in both cases. Users are strongly encouraged to migrate to YYERROR, which is specified by POSIX. Like YYERROR, you can invoke YYFAIL from a semantic action in order to induce a syntax error. The most obvious difference from YYERROR is that YYFAIL will automatically invoke yyerror to report the syntax error so that you don't have to. However, there are several other subtle differences between YYERROR and YYFAIL, and YYFAIL suffers from inherent flaws when %error-verbose or `#define YYERROR_VERBOSE' is used. For a more detailed discussion, see: http://lists.gnu.org/archive/html/bison-patches/2009-12/msg00024.html The upcoming Bison 2.5 will remove YYFAIL from Java parsers, but deterministic parsers in C will continue to implement it. However, because YYFAIL is already flawed, it seems futile to try to make new Bison features compatible with it. Thus, during parser generation, Bison 2.5 will produce a warning whenever it discovers YYFAIL in a rule action. In a later release, YYFAIL will be disabled for %error-verbose and `#define YYERROR_VERBOSE'. Eventually, YYFAIL will be removed altogether. There exists at least one case where Bison 2.5's YYFAIL warning will be a false positive. Some projects add phony uses of YYFAIL and other Bison-defined macros for the sole purpose of suppressing C preprocessor warnings (from GCC cpp's -Wunused-macros, for example). To avoid Bison's future warning, such YYFAIL uses can be moved to the epilogue (that is, after the second `%%') in the Bison input file. In this release (2.4.2), Bison already generates its own code to suppress C preprocessor warnings for YYFAIL, so projects can remove their own phony uses of YYFAIL if compatibility with Bison releases prior to 2.4.2 is not necessary. ** Internationalization. Fix a regression introduced in Bison 2.4: Under some circumstances, message translations were not installed although supported by the host system.
2010-05-02 12:41:52 +02:00
share/locale/lv/LC_MESSAGES/bison-runtime.mo
share/locale/ms/LC_MESSAGES/bison-runtime.mo
share/locale/ms/LC_MESSAGES/bison.mo
share/locale/nb/LC_MESSAGES/bison-runtime.mo
share/locale/nb/LC_MESSAGES/bison.mo
share/locale/nl/LC_MESSAGES/bison-runtime.mo
share/locale/nl/LC_MESSAGES/bison.mo
share/locale/pl/LC_MESSAGES/bison-runtime.mo
share/locale/pl/LC_MESSAGES/bison.mo
Update to 2.4.2: * Changes in version 2.4.2 (2010-03-20): ** Some portability problems that resulted in failures and livelocks in the test suite on some versions of at least Solaris, AIX, HP-UX, RHEL4, and Tru64 have been addressed. As a result, fatal Bison errors should no longer cause M4 to report a broken pipe on the affected platforms. ** `%prec IDENTIFIER' requires IDENTIFIER to be defined separately. POSIX specifies that an error be reported for any identifier that does not appear on the LHS of a grammar rule and that is not defined by %token, %left, %right, or %nonassoc. Bison 2.3b and later lost this error report for the case when an identifier appears only after a %prec directive. It is now restored. However, for backward compatibility with recent Bison releases, it is only a warning for now. In Bison 2.5 and later, it will return to being an error. ** Detection of GNU M4 1.4.6 or newer during configure is improved. ** Warnings from gcc's -Wundef option about undefined YYENABLE_NLS, YYLTYPE_IS_TRIVIAL, and __STRICT_ANSI__ in C/C++ parsers are now avoided. ** %code is now a permanent feature. A traditional Yacc prologue directive is written in the form: %{CODE%} To provide a more flexible alternative, Bison 2.3b introduced the %code directive with the following forms for C/C++: %code {CODE} %code requires {CODE} %code provides {CODE} %code top {CODE} These forms are now considered permanent features of Bison. See the %code entries in the section "Bison Declaration Summary" in the Bison manual for a summary of their functionality. See the section "Prologue Alternatives" for a detailed discussion including the advantages of %code over the traditional Yacc prologue directive. Bison's Java feature as a whole including its current usage of %code is still considered experimental. ** YYFAIL is deprecated and will eventually be removed. YYFAIL has existed for many years as an undocumented feature of deterministic parsers in C generated by Bison. Previously, it was documented for Bison's experimental Java parsers. YYFAIL is no longer documented for Java parsers and is formally deprecated in both cases. Users are strongly encouraged to migrate to YYERROR, which is specified by POSIX. Like YYERROR, you can invoke YYFAIL from a semantic action in order to induce a syntax error. The most obvious difference from YYERROR is that YYFAIL will automatically invoke yyerror to report the syntax error so that you don't have to. However, there are several other subtle differences between YYERROR and YYFAIL, and YYFAIL suffers from inherent flaws when %error-verbose or `#define YYERROR_VERBOSE' is used. For a more detailed discussion, see: http://lists.gnu.org/archive/html/bison-patches/2009-12/msg00024.html The upcoming Bison 2.5 will remove YYFAIL from Java parsers, but deterministic parsers in C will continue to implement it. However, because YYFAIL is already flawed, it seems futile to try to make new Bison features compatible with it. Thus, during parser generation, Bison 2.5 will produce a warning whenever it discovers YYFAIL in a rule action. In a later release, YYFAIL will be disabled for %error-verbose and `#define YYERROR_VERBOSE'. Eventually, YYFAIL will be removed altogether. There exists at least one case where Bison 2.5's YYFAIL warning will be a false positive. Some projects add phony uses of YYFAIL and other Bison-defined macros for the sole purpose of suppressing C preprocessor warnings (from GCC cpp's -Wunused-macros, for example). To avoid Bison's future warning, such YYFAIL uses can be moved to the epilogue (that is, after the second `%%') in the Bison input file. In this release (2.4.2), Bison already generates its own code to suppress C preprocessor warnings for YYFAIL, so projects can remove their own phony uses of YYFAIL if compatibility with Bison releases prior to 2.4.2 is not necessary. ** Internationalization. Fix a regression introduced in Bison 2.4: Under some circumstances, message translations were not installed although supported by the host system.
2010-05-02 12:41:52 +02:00
share/locale/pt/LC_MESSAGES/bison-runtime.mo
share/locale/pt/LC_MESSAGES/bison.mo
share/locale/pt_BR/LC_MESSAGES/bison-runtime.mo
share/locale/pt_BR/LC_MESSAGES/bison.mo
share/locale/ro/LC_MESSAGES/bison-runtime.mo
share/locale/ro/LC_MESSAGES/bison.mo
share/locale/ru/LC_MESSAGES/bison-runtime.mo
share/locale/ru/LC_MESSAGES/bison.mo
share/locale/sl/LC_MESSAGES/bison-runtime.mo
share/locale/sv/LC_MESSAGES/bison-runtime.mo
share/locale/sv/LC_MESSAGES/bison.mo
share/locale/th/LC_MESSAGES/bison-runtime.mo
share/locale/tr/LC_MESSAGES/bison-runtime.mo
share/locale/tr/LC_MESSAGES/bison.mo
share/locale/uk/LC_MESSAGES/bison-runtime.mo
share/locale/uk/LC_MESSAGES/bison.mo
share/locale/vi/LC_MESSAGES/bison-runtime.mo
share/locale/vi/LC_MESSAGES/bison.mo
share/locale/zh_CN/LC_MESSAGES/bison-runtime.mo
share/locale/zh_TW/LC_MESSAGES/bison-runtime.mo
share/locale/zh_TW/LC_MESSAGES/bison.mo