NEWS

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