X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/a2e3fa776815138196cb0fec9d164f7e23b93119..6130b75585cad5f4bb2ee78875a0bfe109b2a3e3:/TODO?ds=inline diff --git a/TODO b/TODO index 634082ab..a9ec3083 100644 --- a/TODO +++ b/TODO @@ -1,12 +1,84 @@ -*- outline -*- +* Short term +** Use b4_symbol in all the skeleton +Then remove the older system, including the tables generated by +output.c + +** Update the documentation on gnu.org + +** Get rid of fake #lines [Bison: ...] +Possibly as simple as checking whether the column number is nonnegative. + +I have seen messages like the following from GCC. + +:0: fatal error: opening dependency file .deps/libltdl/argz.Tpo: No such file or directory + + +** Document %define assert + +** Discuss about %printer/%destroy in the case of C++. +It would be very nice to provide the symbol classes with an operator<< +and a destructor. Unfortunately the syntax we have chosen for +%destroy and %printer make them hard to reuse. For instance, the user +is invited to write something like + + %printer { debug_stream() << $$; } ; + +which is hard to reuse elsewhere since it wants to use +"debug_stream()" to find the stream to use. The same applies to +%destroy: we told the user she could use the members of the Parser +class in the printers/destructors, which is not good for an operator<< +since it is no longer bound to a particular parser, it's just a +(standalone symbol). + +** Rename LR0.cc +as lr0.cc, why upper case? + +** bench several bisons. +Enhance bench.pl with %b to run different bisons. + +** Use b4_symbol everywhere. +Move its definition in the more standard places and deploy it in other +skeletons. + * Various +** YYPRINT +glr.c inherits its symbol_print function from c.m4, which supports +YYPRINT. But to use YYPRINT yytoknum is needed, which not defined by +glr.c. + +Anyway, IMHO YYPRINT is obsolete and should be restricted to yacc.c. + ** YYERRCODE Defined to 256, but not used, not documented. Probably the token number for the error token, which POSIX wants to be 256, but which Bison might renumber if the user used number 256. Keep fix and doc? Throw away? +We could (should?) also treat the case of the undef_token, which is +numbered 257 for yylex, and 2 internal. Both appear for instance in +toknum: + + const unsigned short int + parser::yytoken_number_[] = + { + 0, 256, 257, 258, 259, 260, 261, 262, 263, 264, + +while here + + enum yytokentype { + TOK_EOF = 0, + TOK_EQ = 258, + +so both 256 and 257 are "mysterious". + + const char* + const parser::yytname_[] = + { + "\"end of command\"", "error", "$undefined", "\"=\"", "\"break\"", + + ** YYFAIL It is seems to be *really* obsolete now, shall we remove it? @@ -77,6 +149,21 @@ including the separation bw declaration and definition. See for instance b4_table_define in lalr1.cc. This way, we could even factor C vs. C++ definitions. +* From lalr1.cc to yacc.c +** Single stack +Merging the three stacks in lalr1.cc simplified the code, prompted for +other improvements and also made it faster (probably because memory +management is performed once instead of three times). I suggest that +we do the same in yacc.c. + +** yysyntax_error +In lalr1.cc we invoke it with the translated lookahead (yytoken), and +yacc.c uses yychar. I don't see why. + +** yysyntax_error +The use of switch to select yyfmt in lalr1.cc seems simpler than +what's done in yacc.c. + * Header guards From Franc,ois: should we keep the directory part in the CPP guard? @@ -95,10 +182,6 @@ find something clean (not like YYLSP_NEEDED...). Before releasing, make sure the documentation ("Understanding your parser") refers to the current `output' format. -* lalr1.cc -** I18n -Catch up with yacc.c. - * Report ** GLR