NEWS

   1 Bison News
   2 ----------
   3
   4 Changes in version 1.49a:
   5
   6 * Large grammars
   7   Are now supported (large token numbers, large grammar size (= sum of
   8   the LHS and RHS lengths).
   9
  10 * The initial rule is explicit.
  11   Bison used to play hacks with the initial rule, which the user does
  12   not write.  It is now explicit, and visible in the reports and
  13   graphs as rule 0.
  14
  15 * Useless rules are actually removed.
  16   Before, Bison reported the useless rules, but, although not used,
  17   included them in the parsers.
  18
  19 * False `Token not used' report fixed.
  20   On a grammar such as
  21
  22            %token useless useful
  23            %%
  24            exp: '0' %prec useful;
  25
  26   where a token was used to set the precedence of the last rule,
  27   bison reported both `useful' and `useless' as useless tokens.
  28
  29 * Revert the C++ namespace changes introduced in 1.31, as they caused too
  30   many portability hassles.
  31
  32 * Items overflow
  33   Bison no longer dumps core when there are too many items, it just
  34   dies.
  35
  36 * Token end-of-file
  37   The token end of file may be specified by the user, in which case,
  38   the user symbol is used in the reports, the graphs, and the verbose
  39   error messages instead of `$', which remains being the defaults.
  40   For instance
  41      %token YYEOF 0
  42   or
  43      %token YYEOF 0 "end of file"
  44 \f
  45 Changes in version 1.31, 2002-01-14:
  46
  47 * Many Bug Fixes
  48
  49 * GNU Gettext and %expect
  50   GNU Gettext asserts 10 s/r conflicts, but there are 7.  Now that
  51   Bison dies on incorrect %expectations, we fear there will be
  52   too many bug reports for Gettext, so _for the time being_, %expect
  53   does not trigger an error when the input file is named `plural.y'.
  54
  55 * Use of alloca in parsers
  56   If YYSTACK_USE_ALLOCA is defined to 0, then the parsers will use
  57   malloc exclusively.  Since 1.29, but was not NEWS'ed.
  58
  59   alloca is used only when compiled with GCC, to avoid portability
  60   problems as on AIX.
  61
  62 * When the generated parser lacks debugging code, YYDEBUG is now 0
  63   (as POSIX requires) instead of being undefined.
  64
  65 * User Actions
  66   Bison has always permitted actions such as { $$ = $1 }: it adds the
  67   ending semicolon.  Now if in Yacc compatibility mode, the semicolon
  68   is no longer output: one has to write { $$ = $1; }.
  69
  70 * Better C++ compliance
  71   The output parsers try to respect C++ namespaces.
  72
  73 * Reduced Grammars
  74   Fixed bugs when reporting useless nonterminals.
  75
  76 * 64 bit hosts
  77   The parsers work properly on 64 bit hosts.
  78
  79 * Error messages
  80   Some calls to strerror resulted in scrambled or missing error messages.
  81
  82 * %expect
  83   When the number of shift/reduce conflicts is correct, don't issue
  84   any warning.
  85
  86 * The verbose report includes the rule line numbers.
  87
  88 * Rule line numbers are fixed in traces.
  89
  90 * Swedish translation
  91
  92 * Parse errors
  93   Verbose parse error messages from the parsers are better looking.
  94   Before: parse error: unexpected `'/'', expecting `"number"' or `'-'' or `'(''
  95      Now: parse error: unexpected '/', expecting "number" or '-' or '('
  96
  97 * Fixed parser memory leaks.
  98   When the generated parser was using malloc to extend its stacks, the
  99   previous allocations were not freed.
 100
 101 * Fixed verbose output file.
 102   Some newlines were missing.
 103   Some conflicts in state descriptions were missing.
 104
 105 * Fixed conflict report.
 106   Option -v was needed to get the result.
 107
 108 * %expect
 109   Was not used.
 110   Mismatches are errors, not warnings.
 111
 112 * Fixed incorrect processing of some invalid input.
 113
 114 * Fixed CPP guards: 9foo.h uses BISON_9FOO_H instead of 9FOO_H.
 115
 116 * Fixed some typos in the documentation.
 117
 118 * %token MY_EOF 0 is supported.
 119   Before, MY_EOF was silently renumbered as 257.
 120
 121 * doc/refcard.tex is updated.
 122
 123 * %output, %file-prefix, %name-prefix.
 124   New.
 125
 126 * --output
 127   New, aliasing `--output-file'.
 128 \f
 129 Changes in version 1.30:
 130
 131 * `--defines' and `--graph' have now an optionnal argument which is the
 132   output file name. `-d' and `-g' do not change, they do not take any
 133   argument.
 134
 135 * `%source_extension' and `%header_extension' are removed, failed
 136   experiment.
 137
 138 * Portability fixes.
 139 \f
 140 Changes in version 1.29, 2001-09-07:
 141
 142 * The output file does not define const, as this caused problems when used
 143   with common autoconfiguration schemes.  If you still use ancient compilers
 144   that lack const, compile with the equivalent of the C compiler option
 145   `-Dconst='.  autoconf's AC_C_CONST macro provides one way to do this.
 146
 147 * Added `-g' and `--graph'.
 148
 149 * The Bison manual is now distributed under the terms of the GNU FDL.
 150
 151 * The input and the output files has automatically a similar extension.
 152
 153 * Russian translation added.
 154
 155 * NLS support updated; should hopefully be less troublesome.
 156
 157 * Added the old Bison reference card.
 158
 159 * Added `--locations' and `%locations'.
 160
 161 * Added `-S' and `--skeleton'.
 162
 163 * `%raw', `-r', `--raw' is disabled.
 164
 165 * Special characters are escaped when output.  This solves the problems
 166   of the #line lines with path names including backslashes.
 167
 168 * New directives.
 169   `%yacc', `%fixed_output_files', `%defines', `%no_parser', `%verbose',
 170   `%debug', `%source_extension' and `%header_extension'.
 171
 172 * @$
 173   Automatic location tracking.
 174 \f
 175 Changes in version 1.28, 1999-07-06:
 176
 177 * Should compile better now with K&R compilers.
 178
 179 * Added NLS.
 180
 181 * Fixed a problem with escaping the double quote character.
 182
 183 * There is now a FAQ.
 184 \f
 185 Changes in version 1.27:
 186
 187 * The make rule which prevented bison.simple from being created on
 188   some systems has been fixed.
 189 \f
 190 Changes in version 1.26:
 191
 192 * Bison now uses automake.
 193
 194 * New mailing lists: <bug-bison@gnu.org> and <help-bison@gnu.org>.
 195
 196 * Token numbers now start at 257 as previously documented, not 258.
 197
 198 * Bison honors the TMPDIR environment variable.
 199
 200 * A couple of buffer overruns have been fixed.
 201
 202 * Problems when closing files should now be reported.
 203
 204 * Generated parsers should now work even on operating systems which do
 205   not provide alloca().
 206 \f
 207 Changes in version 1.25, 1995-10-16:
 208
 209 * Errors in the input grammar are not fatal; Bison keeps reading
 210 the grammar file, and reports all the errors found in it.
 211
 212 * Tokens can now be specified as multiple-character strings: for
 213 example, you could use "<=" for a token which looks like <=, instead
 214 of chosing a name like LESSEQ.
 215
 216 * The %token_table declaration says to write a table of tokens (names
 217 and numbers) into the parser file.  The yylex function can use this
 218 table to recognize multiple-character string tokens, or for other
 219 purposes.
 220
 221 * The %no_lines declaration says not to generate any #line preprocessor
 222 directives in the parser file.
 223
 224 * The %raw declaration says to use internal Bison token numbers, not
 225 Yacc-compatible token numbers, when token names are defined as macros.
 226
 227 * The --no-parser option produces the parser tables without including
 228 the parser engine; a project can now use its own parser engine.
 229 The actions go into a separate file called NAME.act, in the form of
 230 a switch statement body.
 231 \f
 232 Changes in version 1.23:
 233
 234 The user can define YYPARSE_PARAM as the name of an argument to be
 235 passed into yyparse.  The argument should have type void *.  It should
 236 actually point to an object.  Grammar actions can access the variable
 237 by casting it to the proper pointer type.
 238
 239 Line numbers in output file corrected.
 240 \f
 241 Changes in version 1.22:
 242
 243 --help option added.
 244 \f
 245 Changes in version 1.20:
 246
 247 Output file does not redefine const for C++.
 248
 249 Local Variables:
 250 mode: outline
 251 End: