X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/d4bdb9167769a7247ac7c93c03fbe9ff7c238d34..f124d4233fcdb7c5e5cb966cbe24f060e737190f:/ChangeLog diff --git a/ChangeLog b/ChangeLog index c78d9446..e151d0bc 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,27 +1,408 @@ -2007-01-18 Joel E. Denny - - Implement @gettext<...@> directive to call gettext from skeletons. It - can be used anywhere including inside arguments of directives of the - form @foo(...@). Eventually, it should be possible to write an - xgettext-like utility to extract @gettext<...@> text from skeletons. - * data/bison.m4 (b4_check_user_names): Use @gettext<...@> when invoking - b4_warn_at since b4_warn_at doesn't invoke gettext anymore. - * data/glr.cc, data/lalr1.cc: Likewise but for b4_fatal and - b4_complain reporting a push-parsing request or a missing %defines. - * src/scan-skel.l (INITIAL): Recognize `@gettext<' to start... - (SC_AT_GETTEXT_ARG): ... this new start condition where gettext is - invoked. - (SC_AT_DIRECTIVE_ARG): Rename to... - (SC_AT_DIRECTIVE_ARGS): ... this, and recognize `@gettext<' to start - SC_AT_GETTEXT_ARG. - (at_directive_perform): Don't invoke gettext for @warn(...@), - @warn_at(...@), etc. Instead, let the skeletons decide what should be - passed to @gettext<...@>. - * tests/skeletons.at (@gettext<...@>): New test case. +2007-05-20 Joel E. Denny + + Extend the front-end API for %define variables to more completely + mirror the back-end. This will be useful in the future. + * data/bison.m4 (b4_percent_define_get, b4_percent_define_ifdef): + Update comments to mention the new front-end counterparts of these + macros. + * src/muscle_tab.c (MUSCLE_COMMON_DECODE): New macro with common code + for muscle_string_decode and muscle_location_decode. + (muscle_string_decode): New static function. + (muscle_location_decode): Use MUSCLE_COMMON_DECODE. + (muscle_percent_define_get, muscle_percent_define_ifdef): New + functions. + (muscle_percent_define_flag_if): Use muscle_percent_define_ifdef and + muscle_percent_define_get to mimic the b4_percent_define_flag_if + implementation more closely. + (muscle_percent_define_invalid_value): New function. + * src/muscle_tab.h (muscle_percent_define_get, + muscle_percent_define_ifdef, muscle_percent_define_invalid_value): + Prototype. + +2007-05-07 Joel E. Denny + + * NEWS (2.3a+): Mention yesterday's state-removal change. + (2.3a): Remove the %language entry, which was added after 2.3a. + * src/LR0.c, src/closure.c, src/closure.h, src/conflicts.c, + src/conflicts.h, src/lalr.c, src/lalr.h, src/print.c, + src/print_graph.c, src/state.c, src/state.h, tests/conflicts.at, + tests/existing.at: Update copyright date. + +2007-05-06 Joel E. Denny + + If conflict resolution makes states unreachable, remove those states, + report rules that are then unused, and don't report conflicts in those + states. + * src/conflicts.c, src/conflicts.h (conflicts_update_state_numbers): + New global function. + * src/lalr.c, src/lalr.h (lalr_update_state_numbers): New global + function. + * src/main.c (main): After conflict resolution, remove the unreachable + states and update all data structures that reference states by number. + * src/state.c (state_new): Initialize each state's reachable member to + false. + (state_mark_reachable_states): New static function. + (state_remove_unreachable_states): New global function. + * src/state.h (struct state): Add member bool reachable. + (state_remove_unreachable_states): Prototype. + * tests/conflicts.at (Unreachable States After Conflict Resolution): + New test case. + * tests/existing.at (GNU pic Grammar): Update test case output now that + an unused rule is discovered. + +2007-05-06 Joel E. Denny + + Minor code cleanup in parser table construction. + * src/LR0.c (new_itemsets): Use item_number_is_symbol_number. + (new_itemsets, save_reductions): Update for rename to nitemset. + * src/closure.c (nritemset): Rename to... + (nitemset): ... this since the "r" appears to meaningless and isn't + used in the comments. + (closure): Update for rename. + * src/closure.h (nritemset): Update extern to... + (nitemset): ... this. + * src/lalr.c (LA): Fix a typo in comments. + * src/print.c (print_core): Update for rename to nitemset. + * src/print_graph.c (print_graph): Likewise. + * src/state.h: Fix some typos in header comments. + +2007-04-04 Paul Eggert + + * THANKS: Use ASCII for Sebastien Fricker's name. Bison source + still sticks to ASCII. Sorry! + + * README-hacking: New file, taken mostly from coreutils, with changes + for Bison. Contains much of the contents of: + * README-cvs: Remove. + * bootstrap: Sync from gnulib. + * build-aux/.cvsignore: Remove *.t, mkinstalldirs. + * lib/.cvsignore: Add wchar.h, wctype.h. Remove exit.h. + +2007-03-10 Joel E. Denny + + * doc/bison.texinfo (Destructor Decl): Fix typo reported by Sebastian + Setzer. + (Java Differences): Fix some typos. + * THANKS: Add Sebastian Setzer. + +2007-03-07 Paolo Bonzini + + * data/java.m4 (b4_single_class_if): Remove. + (b4_abstract_if): Look at "%define abstract". + (b4_lexer_if): New. + (b4_union_name): Rename... + (b4_yystype): ... to this. Map to "%define stype". + (b4_rhs_value, b4_parse_param_decl, b4_lex_param_decl, + b4_maybe_throws): Fix quoting. + (b4_lex_param_call): Move below to keep b4_*_param_decl close. + * data/lalr1.java (Lexer interface): Always define. + (Lexer interface within parser class): Remove. + (YYLexer class): New, used when "%code lexer" is present. + (constructor): When "%code lexer" is used, pass %lex-param + to the lexer constructor. + (yylex, yyparse): Remove %lex-param from method invocations + (YYStack, yyaction, yyparse): Rename b4_union_name to b4_yystype. + + * doc/bison.texinfo (Java Bison Interface): Mention "%define + abstract". Rename "%define union_name" to "%define stype". + Rename method names according to previous patch. + (Java Scanner Interface): Describe "%code lexer" instead of + "%pure-parser" and "%define single_class". + (Java Differences): Mention "%code lexer". + + * tests/java.at (_AT_DATA_JAVA_CALC_Y): Remove final argument. + Include scanner here, using macros from tests/local.at. + (AT_DATA_CALC_Y): Remove final argument. + (_AT_CHECK_JAVA_CALC): Likewise. + (AT_CHECK_JAVA_CALC): Likewise. Test all four combinations + of %locations and %error-verbose. + (main): Test with and without %lex-param. + * tests/local.at (_AT_BISON_OPTION_PUSHDEFS): Push AT_LEXPARAM_IF. + (AT_BISON_OPTION_POPDEFS): Pop it. + +2007-03-07 Juan Manuel Guerrero + + DJGPP spefic issue. Inhibit the use of disallowed characters for + file name genertion on Win98, WinXP, etc. These are |<>":?*\ + and concern testsuite case 46. + * Makefile.am: djgpp/testsuite.sed added to EXTRA_DIST + * djgpp/testsuite.sed: Inhibit the use of disallowed characters. + * djgpp/config.bat: Inhibit the use of disallowed characters. + +2007-03-02 Joel E. Denny + + Miscellaneous %define and %code cleanup. + * data/bison.m4 (b4_percent_define_flag_if): Correct comments on how + values are interpreted. + * doc/bison.texinfo (Decl Summary): Clean up and extend %define + documentation a little more. + * src/muscle_tab.c (MUSCLE_USER_NAME_CONVERT, + muscle_percent_define_insert, muscle_percent_code_grow): New + functions/macros. + * src/muscle_tab.h (muscle_percent_define_insert, + muscle_percent_code_grow): Prototype. + * src/parse-gram.y (prologue_declaration): Use + muscle_percent_define_insert and muscle_percent_code_grow when parsing + %define and %code directives. + + Make it easy to share %define boolean variables between the front-end + and back-end. Though not used yet, this will be useful in the future. + * data/bison.m4 (b4_check_user_names): Rewrite comments to talk about + Bison uses of names rather than just skeleton uses of names. + (b4_percent_define_get, b4_percent_define_ifdef): Rename + b4_percent_define_skeleton_variables(VARIABLE) to + b4_percent_define_bison_variables(VARIABLE). + (b4_percent_code_get, b4_percent_code_ifdef): Rename + b4_percent_code_skeleton_qualifiers(QUALIFIER) to + b4_percent_code_bison_qualifiers(QUALIFIER). + (b4_check_user_names_wrap): Update for renames. + * src/muscle_tab.c, src/muscle_tab.h (muscle_percent_define_flag_if, + muscle_percent_define_default): New functions mimicking + b4_percent_define_flag_if and b4_percent_define_default. + + For %define variables, report locations for invalid values and + redefinitions. + * data/bison.m4 (b4_percent_define_flag_if): Read + b4_percent_define_loc(VARIABLE) to report the location of an invalid + value for VARIABLE. + (b4_percent_define_default): Save a special location in + b4_percent_define_loc(VARIABLE) in case the default value for VARIABLE + must later be reported as invalid. + * src/muscle_tab.c (muscle_location_grow, muscle_location_decode): New + functions. + (muscle_percent_define_insert): Record the location of VARIABLE in + muscle percent_define_loc(VARIABLE), and use it to report the previous + location for a redefinition. + (muscle_percent_define_flag_if): Update like b4_percent_define_flag_if. + (muscle_percent_define_default): Update like b4_percent_define_default. + (muscle_grow_user_name_list): Rename to... + (muscle_user_name_list_grow): ... this for consistency and use + muscle_location_grow. + * src/muscle_tab.h (muscle_location_grow): Prototype. + * tests/input.at (%define errors): Update expected output. + * tests/skeletons.at (%define boolean variables: invalid skeleton + defaults): New test case. + +2007-02-28 Joel E. Denny + + * src/print.c (lookahead_set, state_default_rule): Remove. + (print_reductions): Replace state_default_rule invocation with + equivalent use of yydefact, which was computed in token_actions in + tables.c. + (print_results): Don't allocate lookahead_set. + +2007-02-27 Paolo Bonzini + + * data/lalr1.java: Prefix all private members with yy. + +2007-02-24 Joel E. Denny + + Use YYFPRINTF instead of fprintf where appropriate. Reported by + Sebastien Fricker at + . + * THANKS: Add Sebastien Fricker. + * data/glr.c, data/push.c, data/yacc.c (yy_reduce_print): Implement. + * doc/bison.texinfo (Tracing): Make it clearer that YYFPRINTF must + accept a variable number of arguments. + +2007-02-19 Joel E. Denny + + * bootstrap: Remove occurrences of .#bootmp from lib/Makefile. + +2007-02-13 Juan Manuel Guerrero + + * djgpp/config.bat: Adjustments concerning the use of autoconf 2.61. + * djgpp/config.sed: Adjustments concerning the use of autoconf 2.61. + * djgpp/config.site: Adjustments concerning the use of autoconf 2.61. + +2007-02-11 Paul Eggert + + Undo my 2007-02-07 change, switching back to the c-strcase module + introduced in the 2007-02-03 change. Bruno Haible reported that + the 2007-02-07 change would be dangerous in Turkish if we add a + language whose name contains "i", since "i" is not lowercase "I" + in Turkish. + * bootstrap.conf (gnulib_modules): Add c-strcase. Remove strcase. + * lib/.cvsignore: Add c-ctype.c, c-ctype.h, c-strcase.h, + c-strcasecomp.c, c-strncasecmp.c. Remove strcasecmp.c, strncasecmp.c. + * m4/.cvsignore: Remove strcase.m4. + * src/getargs.c: Revert 2007-02-07 change, as follows. + Include c-strcase.h. + (language_argmatch): Use c_strcasecmp rather than strcasecmp. + +2007-02-11 Bruno Haible + + Enable the Java related testsuite tests when the only Java compiler + found is a gcj < 4.3. Discussed at + . + * configure.ac (gt_JAVACOMP): Don't specify a target_version. + +2007-02-11 Joel E. Denny + + * data/Makefile.am: Update copyright date. + * data/push.c (yypull_parse): Report memory exhaustion and return 2 if + yypstate_new returns NULL. + (yypstate_new): Return NULL if malloc does. + * src/reader.c (packgram): Move translation of rule actions from the + beginning of packgram to... + (check_and_convert_grammar): ... here right before packgram is invoked + so it's easier to write more complete comments, and remove redundant + code. +2007-02-10 Joel E. Denny + + As in semantic actions, make @$ in %initial-action, %destructor, and + %printer imply %locations. + * src/scan-code.l (SC_SYMBOL_ACTION): Set locations_flag = true when + scanning @$. + * tests/actions.at (AT_CHECK_ACTION_LOCATIONS): New macro supporting... + (@$ in %initial-action implies %locations, + @$ in %destructor implies %locations, + @$ in %printer implies %locations): ... these new test cases. + +2007-02-07 Paul Eggert + + Undo most of the 2007-02-03 change, switching to the strcase module + now that gnulib strcase has been fixed. + * bootstrap.conf (gnulib_modules): Remove c-strcase. Add strcase. + * lib/.cvsignore: Remove c-ctype.c, c-ctype.h, c-strcase.h, + c-strcasecomp.c, c-strncasecmp.c. Add strcasecmp.c, strncasecmp.c + * m4/.cvsignore: Add strcase.m4. + * src/getargs.c: Revert 2007-02-03 change, as follows. + Don't include c-strcase.h. + (language_argmatch): Use strcasecmp rather than c_strcasecmp. + strcasecmp has "unspecified behavior" outside the POSIX locale, + but it works fine in practice if at least one argument is ASCII, + as is the case in Bison. + +2007-02-07 Paolo Bonzini + + * tests/java.at: Skip tests if only one of javac/java is present. + Reported by Joel E. Denny. + * tests/atlocal.in: Adjust copyright years. + +2007-02-05 Paolo Bonzini + + * data/lalr1.java (Stack): Work around old verifiers that disallow + access to the private fields of an inner class, from the outer class. + We can make Stack's fields public because user code doesn't have access + to the instance of Stack used by parse(). Reported by Paul Eggert. + +2007-02-03 Paul Eggert + + * .cvsignore: Add javacomp.sh, javaexec.sh. Is this really + the right spot for these files? + * bootstrap.conf (gnulib_modules): Add c-strcase. + * lib/.cvsignore: Add c-ctype.c c-ctype.h, c-strcasecomp.c, + c-strncasecmp.c. + * src/getargs.c: Include c-strcase.h. + (language_argmatch): Use c_strcasecmp rather than strcasecmp, + to avoid unspecified behavior. + +2007-02-01 Joel E. Denny + + * doc/bison.texinfo (Decl Summary): Correct typo. + +2007-01-30 Paolo Bonzini + + * data/bison.m4 (b4_percent_define_flag_if): Don't treat 0 as false. + Complain if the value does not match empty, "true" or "false". + * data/c++.m4: Adjust default definitions of %define variables. + * data/java.m4: Adjust default definitions of %define variables. + * doc/bison.texinfo (Decl Summary): Adjust the %define entry according + to above behavior. + * tests/input.at (Boolean %define variables): Test new behavior. + +2007-01-29 Paolo Bonzini + + * NEWS: Mention java. + * TODO: Remove things that are done. + * bootstrap.conf: Add javacomp-script and javaexec-script. + * configure.ac: Invoke gt_JAVACOMP and gt_JAVAEXEC. + + * data/Makefile.am: Add new files. + * data/java-skel.m4: New. + * data/java.m4: New. + * data/lalr1.java: New. + + * doc/bison.texinfo: Put "A Complete C++ Example" under + C++ Parsers. Add Java Parsers. Put C++ Parsers and Java Parsers + under Other Languages. + + * src/getargs.c (valid_languages): Add Java. + * src/getargs.h (struct bison_language): Update size of string fields. + + * tests/Makefile.am: Add java.at. + * tests/atlocal.in: Add CONF_JAVA and CONF_JAVAC. + * tests/java.at: New. + * tests/testsuite.at: Include it. + +2007-01-28 Joel E. Denny + + Clean up. + * src/scan-skel.l (at_directive_perform): Add at_directive_argc and + at_directive_argv arguments so these no longer have to be global + variables. Also, update the implementation for the following changes. + (fail_for_at_directive_too_many_args, + fail_for_at_directive_too_few_args): Add at_directive_name argument. + (at_directive_name): Remove as at_directive_argv[0] will be used for + this now. + (AT_DIRECTIVE_ARGC_MAX): Increment to make space in at_directive_argv + for the directive name. + (at_directive_argc, at_directive_argv): Make these local within + skel_lex instead of global. + (INITIAL): Update directive start action for above changes. + (SC_AT_DIRECTIVE_ARG): Rename to... + (SC_AT_DIRECTIVE_ARGS): ... this, and update for above changes. + (SC_AT_DIRECTIVE_SKIP_WS): Update. + (scan_skel): Move yylex_destroy to... + (skel_scanner_free): ... here. * tests/skeletons.at (installed skeleton file name): Rename to... (installed skeleton file names): ... this. +2007-01-27 Joel E. Denny + + * ChangeLog: For changes in doc/bison.texinfo, consistently reference + node names: say "Table of Symbols" not "Bison Symbols", and say "Decl + Summary" not "Directives". + * doc/bison.texinfo (Decl Summary, Calc++ Parser): Cross-reference the + %code entry in "Decl Summary" rather than the one in "Table of Symbols" + since the former is now the more complete one. + (Prologue Alternatives): Likewise and do the same for %defines. + (Table of Symbols): Add summary of %code, add summary of %define, and + move full %code documentation to... + (Decl Summary): ... here for consistency with other entries in these + sections. + Move %define entry in order to keep this list alphabetized. + Reword %define entry a little to put less emphasis on the skeleton + concept, which most users shouldn't have to think about. + +2007-01-26 Paul Eggert + + Adjust to recent gnulib changes. + * lib/.cvsignore: Remove stpcpy.h, strndup.h, strnlen.h. + Add string.h, string_.h, unistd_.h, wchar_.h. + * m4/.cvsignore: Add gnulib-common.m4, string_h.m4, wchar.m4. + * src/system.h: Don't include ; this is now done by + . + +2007-01-23 Paolo Bonzini + + Simplify implementation of unqualified %code, implement macros for + uniform treatment of boolean %define flags. Document %define. + * data/bison.m4 (b4_percent_define_ifdef, b4_percent_define_flag_if, + b4_percent_code_ifdef): New. + (b4_percent_code_get): Map unqualified %code to b4_percent_code(). + * data/c++.m4: Define default value for global_tokens_and_yystype. + * data/glr.cc: Likewise. + * data/location.cc: Use b4_percent_define_flag_if. + + * doc/bison.texinfo (Decl Summary): Document %define. + + * src/parse-gram.y (Unqualified %code): Change muscle name to + b4_percent_code(). + (content.opt): Default to empty. + 2007-01-17 Joel E. Denny Implement support for relative and absolute skeleton file names. @@ -198,7 +579,7 @@ (C++ Location Values): Update %define uses. (Calc++ Parser Interface): Likewise. (Calc++ Parser): Likewise, and update `%code requires' uses. - (Bison Symbols): Update %code documentation. + (Table of Symbols): Update %code documentation. * src/parse-gram.y (prologue_declaration): For %define variables, use `variable' instead of `STRING'. (grammar_declaration): For %code qualifiers, use `ID' instead of @@ -416,7 +797,7 @@ * doc/bison.texinfo (Prologue Alternatives): Update. (Decl Summary): Update to %code "requires" and %code "provides". (Calc++ Parser): Update to %code "requires". - (Bison Symbols): Remove entries for %requires, %provides, and + (Table of Symbols): Remove entries for %requires, %provides, and %code-top. Rewrite %code entry, and add a %code "QUALIFIER" entry. * data/bison.m4 (b4_user_provides, b4_user_requires): Remove as these are replaced by b4_percent_code_provides and b4_percent_code_requires, @@ -829,7 +1210,7 @@ documentation instead. (Calc++ Parser): Use `%require "@value{VERSION}"' rather than `%require "2.3b"' so that the example is always up-to-date. - (Bison Symbols): Add entries for %language and %skeleton. + (Table of Symbols): Add entries for %language and %skeleton. * examples/extexi (normalize): Instead of replacing every %require argument with the current Bison version, just substitute for `@value{VERSION}'. This guarantees that we're testing what actually @@ -864,7 +1245,7 @@ * doc/bison.texinfo (C++ Parser Interface): Prefer %language over %skeleton. - (Directives): Document %language and %skeleton. + (Decl Summary): Document %language and %skeleton. (Command line): Document -L. * examples/extexi: Rewrite %require directive. @@ -1065,7 +1446,7 @@ (2.3a): Annotate this entry to say the old forms of these features were also experimental. * doc/bison.texinfo (Prologue Alternatives, Freeing Discarded Symbols, - Bison Symbols): Say they're experimental. Comment out any mention + Table of Symbols): Say they're experimental. Comment out any mention of Java (we'll want this back eventually). 2006-12-01 Joel E. Denny @@ -1074,7 +1455,7 @@ %file-prefix, %name-prefix, and %output. Discussed at . * NEWS (2.3a+): Mention. - * doc/bison.texinfo (Decl Summary, Bison Symbols): Add entry for new + * doc/bison.texinfo (Decl Summary, Table of Symbols): Add entry for new form of %defines, and remove `=' from entries for %file-prefix, %name-prefix, and %output. * src/parse-gram.y (prologue_declaration): Implement. @@ -1104,7 +1485,7 @@ Rename to <>. Discussed starting at . * NEWS (2.3a+): Update. - * doc/bison.texinfo (Freeing Discarded Symbols, Bison Symbols): + * doc/bison.texinfo (Freeing Discarded Symbols, Table of Symbols): Update. * src/parse-gram.y (TYPE_TAG_NONE, generic_symlist_item): Implement. * src/scan-gram.l (INITIAL): Implement. @@ -1280,7 +1661,7 @@ * NEWS (2.3a+): Mention. * doc/bison.texinfo (Freeing Discarded Symbols): Document this and the previous change today related to mid-rules. - (Bison Symbols): Remove %symbol-default and add <*> and . + (Table of Symbols): Remove %symbol-default and add <*> and . * src/parse-gram.y (PERCENT_SYMBOL_DEFAULT): Remove. (TYPE_TAG_ANY): Add as <*>. (TYPE_TAG_NONE): Add as . @@ -1373,8 +1754,8 @@ alternatives to... (Prologue Alternatives): ... this new section, and extend it to discuss all 4 directives in detail. - (Bison Symbols): Clean up discussion of prologue alternatives and add - %code-top. + (Table of Symbols): Clean up discussion of prologue alternatives and + add %code-top. 2006-10-16 Juan Manuel Guerrero @@ -1830,7 +2211,7 @@ . * NEWS (2.3+): Add %symbol-default to example. * bison.texinfo (Freeing Discarded Symbols): Likewise. - (Bison Symbols): Add entry for %symbol-default. + (Table of Symbols): Add entry for %symbol-default. * src/parse-gram.y (PERCENT_SYMBOL_DEFAULT): New token. (generic_symlist, generic_symlist_item): New nonterminals for creating a list in which each item is a symbol, semantic type, or @@ -2472,7 +2853,7 @@ prologue blocks with %*-header declarations. (Calc++ Parser): Likewise. (Bison Declaration Summary): Update names. - (Bison Symbols): Update description. + (Table of Symbols): Update description. * src/parse-gram.y (PERCENT_AFTER_DEFINITIONS): Update to... (PERCENT_END_HEADER): ... this. (PERCENT_BEFORE_DEFINITIONS): Update to... @@ -2553,7 +2934,7 @@ file. (Calc++ Parser): Forward declare driver in a %before-definitions rather than in the pre-prologue so that make check succeeds. - (Bison Symbols): Add entries for %before-definitions and + (Table of Symbols): Add entries for %before-definitions and %after-definitions. * src/parse-gram.y (PERCENT_BEFORE_DEFINITIONS): New token for %before-definitions. @@ -3643,7 +4024,7 @@ in the yychar entry. In the yychar entry, remove mention of the local yychar case (pure parser) since this is irrelevant information when writing semantic - actions and since it's already discussed in `Bison Symbols' where + actions and since it's already discussed in `Table of Symbols' where yychar is otherwise described as an external variable. In the yychar entry, don't call it the `current' look-ahead since it isn't when semantic actions are deferred. @@ -3654,7 +4035,7 @@ `current' look-ahead, and do mention yylval and yylloc. (Error Recovery): Cross-reference `Action Features' when mentioning yyclearin. - (Bison Symbols): In the yychar entry, don't call it the `current' + (Table of Symbols): In the yychar entry, don't call it the `current' look-ahead. In the yylloc and yylval entries, mention look-ahead usage.