* Noteworthy changes in release ?.? (????-??-??) [?]
- ** Future changes:
+** Warnings about useless semantic types
+
+ Bison now warns about useless (uninhabited) semantic types. Since
+ semantic types are not declared to Bison (they are defined in the opaque
+ %union structure), it is %printer/%destructor directives about useless
+ types that trigger the warning:
+
+ %token <type1> term
+ %type <type2> nterm
+ %printer {} <type1> <type3>
+ %destructor {} <type2> <type4>
+ %%
+ nterm: term { $$ = $1; };
+
+ 3.28-34: warning: type <type3> is used, but is not associated to any symbol
+ 4.28-34: warning: type <type4> is used, but is not associated to any symbol
+
+** Warnings about undeclared symbols
+
+ Bison used to raise an error for %printer and %destructor directives for
+ undefined symbols.
+
+ %printer {} symbol1
+ %destructor {} symbol2
+ %%
+ exp: "a";
+
+ This is now only a warning.
+
+** Warnings about useless destructors or printers
+
+ Bison now warns about useless destructors or printers. In the following
+ example, the printer for <type1>, and the destructor for <type2> are
+ useless: all symbols of <type1> (token1) already have a printer, and all
+ symbols of type <type2> (token2) already have a destructor.
+
+ %token <type1> token1
+ <type2> token2
+ <type3> token3
+ <type4> token4
+ %printer {} token1 <type1> <type3>
+ %destructor {} token2 <type2> <type4>
+
+** Additional yylex/yyparse arguments
+
+ The new directive %param declares additional arguments to both yylex and
+ yyparse. The %lex-param, %parse-param, and %param directives support one
+ or more arguments. Instead of
+
+ %lex-param {arg1_type *arg1}
+ %lex-param {arg2_type *arg2}
+ %parse-param {arg1_type *arg1}
+ %parse-param {arg2_type *arg2}
+
+ one may now declare
+
+ %param {arg1_type *arg1} {arg2_type *arg2}
+
+** Java skeleton improvements
+
+ The constants for token names were moved to the Lexer interface.
+ Also, it is possible to add code to the parser's constructors using
+ "%code init" and "%define init_throws".
+
+** C++ skeleton improvements
+
+ The C++ parser features a syntax_error exception, which can be
+ thrown from the scanner or from user rules to raise syntax errors.
+ This facilitates reporting errors caught in sub-functions (e.g.,
+ rejecting too large integral literals from a conversion function
+ used by the scanner, or rejecting invalid combinations from a
+ factory invoked by the user actions).
+
+** Variable api.tokens.prefix
+
+ The variable api.tokens.prefix changes the way tokens are identified in
+ the generated files. This is especially useful to avoid collisions
+ with identifiers in the target language. For instance
+
+ %token FILE for ERROR
+ %define api.tokens.prefix "TOK_"
+ %%
+ start: FILE for ERROR;
+
+ will generate the definition of the symbols TOK_FILE, TOK_for, and
+ TOK_ERROR in the generated sources. In particular, the scanner must
+ use these prefixed token names, although the grammar itself still
+ uses the short names (as in the sample rule given above).
+
+** Variable api.namespace
+
+ The "namespace" variable is renamed "api.namespace". Backward
+ compatibility is ensured, but upgrading is recommended.
+
+** Variable parse.error
+
+ The variable error controls the verbosity of error messages. The
+ use of the %error-verbose directive is deprecated in favor of
+ %define parse.error "verbose".
+
+** Semantic predicates
+
+ The new, experimental, semantic-predicate feature allows actions of
+ the form %?{ BOOLEAN-EXPRESSION }, which cause syntax errors (as for
+ YYERROR) if the expression evaluates to 0, and are evaluated immediately
+ in GLR parsers, rather than being deferred. The result is that they
+ allow the programmer to prune possible parses based on the values of
+ runtime expressions.
+
+* Noteworthy changes in release ?.? (????-??-??) [?]
+
+ ** Future changes
+
+ The next major release of Bison will drop support for the following
+ deprecated features. Please report disagreements to bug-bison@gnu.org.
+
+ *** K&C parsers
+
+ Support for generating parsers in K&R C will be removed. Parsers
+ generated for C supprt ISO C90, and are tested with ISO C99 and ISO C11
+ compilers.
+
+ *** Deprecated features
- The next major release will drop support for generating parsers in K&R C,
- and remove the definitions of yystype and yyltype (removal announced since
- Bison 1.875). YYPARSE_PARAM and YYLEX_PARAM, which were deprecated in
- favor of %parse-param and %lex-param (introduced in Bison 1.875 too), will
- no longer be supported.
+ The definitions of yystype and yyltype will be removed, as announced since
+ Bison 1.875. Use YYSTYPE and YYLTYPE only.
- ** The generated header is included (yacc.c)
+ YYPARSE_PARAM and YYLEX_PARAM, which were deprecated in favor of
+ %parse-param and %lex-param (introduced in Bison 1.875), will no longer be
+ supported.
+
+ *** The generated header will be included (yacc.c)
Instead of duplicating the content of the generated header (definition of
- YYSTYPE, yyltype etc.), the generated parser now includes it, as was
- already the case for GLR or C++ parsers.
+ YYSTYPE, yyparse declaration etc.), the generated parser will include it,
+ as is already the case for GLR or C++ parsers. This change is deferred
+ because existing versions of ylwrap (e.g., Automake 1.12.1) do not support
+ it.
** Headers (yacc.c, glr.c, glr.cc)
return YYID (yyresult);
}
-
-]b4_epilogue
+]b4_epilogue[]dnl
b4_defines_if(
[@output(b4_spec_defines_file@)@
-b4_copyright([Bison interface for Yacc-like parsers in C],
- [1984, 1989-1990, 2000-2012])[
+b4_copyright([Bison interface for Yacc-like parsers in C])[
- ]b4_cpp_guard_open([b4_spec_defines_file])[
]b4_shared_declarations[
- ]b4_cpp_guard_close([b4_spec_defines_file])[
]])dnl b4_defines_if
m4_divert_pop(0)
+m4_popdef([b4_copyright_years])
}
void
-default_tagless_printer_set (code_props const *printer)
+default_tagless_code_props_set (code_props_type kind, code_props const *code)
{
- if (default_tagless_printer.code)
+ if (default_tagless_code_props[kind].code)
{
- complain_at (printer->location,
- _("redeclaration for default tagless %%printer"));
- complain_at (default_tagless_printer.location,
- _("previous declaration"));
+ complain_at (code->location,
+ _("redeclaration for default tagless %s"),
+ code_props_type_string (kind));
+ complain_at (default_tagless_code_props[kind].location,
+ _("previous declaration"));
}
- default_tagless_printer = *printer;
+ default_tagless_code_props[kind] = *code;
}
-
/* Nothing. */
{
$$ = 0;
- printf ("input (%d@%d-%d): /* Nothing */\n", $$, RANGE (@$));
+ V(input, $$, @$, ": /* Nothing */\n");
}
| line input /* Right recursive to load the stack so that popping at
- END can be exercised. */
+ END can be exercised. */
{
$$ = 2;
- printf ("input (%d@%d-%d): line (%d@%d-%d) input (%d@%d-%d)\n",
- $$, RANGE (@$), $1, RANGE (@1), $2, RANGE (@2));
+ V(input, $$, @$, ": ");
+ V(line, $1, @1, " ");
+ V(input, $2, @2, "\n");
}
;
[m4_bmatch([$3], [\(%define api\.prefix\|%name-prefix\) ".*"],
[m4_bregexp([$3], [\(%define api\.prefix\|%name-prefix\) "\([^""]*\)"], [\2])],
[yy])])
+m4_pushdef([AT_TOKEN_PREFIX],
+[m4_bmatch([$3], [%define api.tokens.prefix ".*"],
+ [m4_bregexp([$3], [%define api.tokens.prefix "\(.*\)"], [\1])])])
+ m4_pushdef([AT_API_prefix],
+ [m4_bmatch([$3], [%define api\.prefix ".*"],
+ [m4_bregexp([$3], [%define api\.prefix "\([^""]*\)"], [\1])],
+ [yy])])
# yyerror receives the location if %location & %pure & (%glr or %parse-param).
m4_pushdef([AT_YYERROR_ARG_LOC_IF],
[AT_GLR_OR_PARAM_IF([AT_PURE_AND_LOC_IF([$1], [$2])],
# are using the C++ parsers.
m4_pushdef([AT_PURE_LEX_IF],
[AT_PURE_IF([$1],
- [AT_SKEL_CC_IF([$1], [$2])])])
+ [AT_SKEL_CC_IF([$1], [$2])])])
+ m4_pushdef([AT_YYSTYPE],
+ [AT_SKEL_CC_IF([AT_NAME_PREFIX[::parser::semantic_type]],
+ [[YYSTYPE]])])
+ m4_pushdef([AT_YYLTYPE],
+ [AT_SKEL_CC_IF([AT_NAME_PREFIX[::parser::location_type]],
+ [[YYLTYPE]])])
+
+
AT_PURE_LEX_IF(
[m4_pushdef([AT_LOC], [(*llocp)])
m4_pushdef([AT_VAL], [(*lvalp)])
m4_pushdef([AT_YYLEX_FORMALS],
- [YYSTYPE *lvalp[]AT_LOCATION_IF([, YYLTYPE *llocp])])
- [AT_YYSTYPE *lvalp[]AT_LOCATION_IF([, AT_YYLTYPE *llocp])])
++ [AT_YYSTYPE *lvalp[]AT_LOCATION_IF([, AT_YYLTYPE *llocp])])
m4_pushdef([AT_YYLEX_ARGS],
- [lvalp[]AT_LOCATION_IF([, llocp])])
+ [lvalp[]AT_LOCATION_IF([, llocp])])
m4_pushdef([AT_USE_LEX_ARGS],
- [(void) lvalp;AT_LOCATION_IF([(void) llocp])])
+ [(void) lvalp;AT_LOCATION_IF([(void) llocp])])
m4_pushdef([AT_YYLEX_PRE_FORMALS],
-- [AT_YYLEX_FORMALS, ])
++ [AT_YYLEX_FORMALS, ])
m4_pushdef([AT_YYLEX_PRE_ARGS],
-- [AT_YYLEX_ARGS, ])
++ [AT_YYLEX_ARGS, ])
],
[m4_pushdef([AT_LOC], [[(]AT_NAME_PREFIX[lloc)]])
m4_pushdef([AT_VAL], [[(]AT_NAME_PREFIX[lval)]])
# AT_COMPILE(OUTPUT, [SOURCES = OUTPUT.c])
# ----------------------------------------
- # Compile SOURCES into OUTPUT. If OUTPUT does not contain '.',
- # assume that we are linking too; this is a hack.
+ # Compile SOURCES into OUTPUT.
+ #
+ # If OUTPUT does not contain '.', assume that we are linking too,
+ # otherwise pass "-c"; this is a hack. The default SOURCES is OUTPUT
+ # with trailing .o removed, and ".c" appended.
m4_define([AT_COMPILE],
- [AT_CHECK([$CC $CFLAGS $CPPFLAGS m4_bmatch([$1], [[.]], [], [$LDFLAGS ])-o $1 m4_default([$2], [$1.c])[]m4_bmatch([$1], [[.]], [], [ $LIBS])],
+ [AT_CHECK(m4_join([ ],
+ [$CC $CFLAGS $CPPFLAGS],
+ [m4_bmatch([$1], [[.]], [-c], [$LDFLAGS])],
+ [-o $1],
+ [m4_default([$2], [m4_bpatsubst([$1], [\.o$]).c])],
+ [m4_bmatch([$1], [[.]], [], [$LIBS])]),
- 0, [ignore], [ignore])])
+ 0, [ignore], [ignore])])
# AT_COMPILE_CXX(OUTPUT, [SOURCES = OUTPUT.cc])
- # --------------------------------------------
- # Compile SOURCES into OUTPUT. If OUTPUT does not contain '.',
- # assume that we are linking too; this is a hack.
- # If the C++ compiler does not work, ignore the test.
+ # ---------------------------------------------
+ # Compile SOURCES into OUTPUT. If the C++ compiler does not work,
+ # ignore the test.
+ #
+ # If OUTPUT does not contain '.', assume that we are linking too,
+ # otherwise pass "-c"; this is a hack. The default SOURCES is OUTPUT
+ # with trailing .o removed, and ".cc" appended.
m4_define([AT_COMPILE_CXX],
[AT_KEYWORDS(c++)
AT_CHECK([$BISON_CXX_WORKS], 0, ignore, ignore)
- AT_CHECK([$CXX $CXXFLAGS $CPPFLAGS m4_bmatch([$1], [[.]], [], [$LDFLAGS ])-o $1 m4_default([$2], [$1.cc])[]m4_bmatch([$1], [[.]], [], [ $LIBS])],
+ AT_CHECK(m4_join([ ],
+ [$CXX $CXXFLAGS $CPPFLAGS],
+ [m4_bmatch([$1], [[.]], [-c], [$LDFLAGS])],
+ [-o $1],
+ [m4_default([$2], [m4_bpatsubst([$1], [\.o$]).cc])],
+ [m4_bmatch([$1], [[.]], [], [$LIBS])]),
- 0, [ignore], [ignore])])
+ 0, [ignore], [ignore])])
# AT_JAVA_COMPILE(SOURCES)
# ------------------------
projects / bison.git / commitdiff
