NEWS

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