X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/01ed3db59ba1c0219a75da68788e792f274d4a4e..cd6a695eb90ec4b9597c0aa843aa54558df43e0c:/TODO

diff --git a/TODO b/TODO
index 931df7ae..a437ab07 100644
--- a/TODO
+++ b/TODO
@@ -1,24 +1,125 @@
 -*- outline -*-
 
-* src/reader.c
-** Complete parse_skel_decl () with parse_dquoted_param ().
-** Check and cleanup for CPP-out code.
+* NEWS
+Sort from 1.31 NEWS.
 
-* src/output.c
-** Output sub-skeleton files.
-** Cleanup dirty CPP-out code.
-** s/definitions/prologue/  s/user_code/epilogue/ [ok].
-** s/macro/muscle/
+* Prologue
+The %union is declared after the user C declarations. It can be
+a problem if YYSTYPE is declared after the user part.	[]
 
-* src/getargs.c src/lex.c
-** Synchronize percent and command line options.
+Actually, the real problem seems that the %union ought to be output
+where it was defined.  For instance, in gettext/intl/plural.y, we
+have:
 
-* src/macrotab.[ch]
-** Removing warnings when compiling. (gcc-warnings) [ok].
-** s/macro/muscle/
+	%{
+	...
+	#include "gettextP.h"
+	...
+	%}
+
+	%union {
+	  unsigned long int num;
+	  enum operator op;
+	  struct expression *exp;
+	}
+
+	%{
+	...
+	static int yylex PARAMS ((YYSTYPE *lval, const char **pexp));
+	...
+	%}
+
+Where the first part defines struct expression, the second uses it to
+define YYSTYPE, and the last uses YYSTYPE.  Only this order is valid.
+
+* --graph
+Show reductions.	[]
+
+* Broken options ?
+** %no-lines		[ok]
+** %no-parser		[]
+** %pure-parser		[]
+** %semantic-parser	[]
+** %token-table		[]
+** Options which could use parse_dquoted_param ().
+Maybe transfered in lex.c.
+*** %skeleton		[ok]
+*** %output		[]
+*** %file-prefix	[]
+*** %name-prefix	[]
+
+** Skeleton strategy.	[]
+Must we keep %no-parser?
+	     %token-table?
+*** New skeletons.	[]
 
 * src/print_graph.c
-** Find the best graph parameters.
+Find the best graph parameters.	[]
 
 * doc/bison.texinfo
-** Echo modifications of prologue and epilogue.
\ No newline at end of file
+** Update
+informations about ERROR_VERBOSE.	[]
+** Add explainations about
+skeleton muscles.	[]
+%skeleton.		[]
+
+* testsuite
+** tests/pure-parser.at	[]
+New tests.
+
+* Debugging parsers
+
+From Greg McGary:
+
+akim demaille <akim.demaille@epita.fr> writes:
+
+> With great pleasure!  Nonetheless, things which are debatable
+> (or not, but just `big') should be discuss in `public': something
+> like help- or bug-bison@gnu.org is just fine.  Jesse and I are there,
+> but there is also Jim and some other people.
+
+I have no idea whether it qualifies as big or controversial, so I'll
+just summarize for you.  I proposed this change years ago and was
+surprised that it was met with utter indifference!
+
+This debug feature is for the programs/grammars one develops with
+bison, not for debugging bison itself.  I find that the YYDEBUG
+output comes in a very inconvenient format for my purposes.
+When debugging gcc, for instance, what I want is to see a trace of
+the sequence of reductions and the line#s for the semantic actions
+so I can follow what's happening.  Single-step in gdb doesn't cut it
+because to move from one semantic action to the next takes you through
+lots of internal machinery of the parser, which is uninteresting.
+
+The change I made was to the format of the debug output, so that it
+comes out in the format of C error messages, digestible by emacs
+compile mode, like so:
+
+grammar.y:1234: foo: bar(0x123456) baz(0x345678)
+
+where "foo: bar baz" is the reduction rule, whose semantic action
+appears on line 1234 of the bison grammar file grammar.y.  The hex
+numbers on the rhs tokens are the parse-stack values associated with
+those tokens.  Of course, yytype might be something totally
+incompatible with that representation, but for the most part, yytype
+values are single words (scalars or pointers).  In the case of gcc,
+they're most often pointers to tree nodes.  Come to think of it, the
+right thing to do is to make the printing of stack values be
+user-definable.  It would also be useful to include the filename &
+line# of the file being parsed, but the main filename & line# should
+continue to be that of grammar.y
+
+Anyway, this feature has saved my life on numerous occasions.  The way
+I customarily use it is to first run bison with the traces on, isolate
+the sequence of reductions that interests me, put those traces in a
+buffer and force it into compile-mode, then visit each of those lines
+in the grammar and set breakpoints with C-x SPACE.  Then, I can run
+again under the control of gdb and stop at each semantic action.
+With the hex addresses of tree nodes, I can inspect the values
+associated with any rhs token.
+
+You like?
+
+* input synclines
+Some users create their foo.y files, and equip them with #line.  Bison
+should recognize these, and preserve them.