-Wempty-rule: diagnose empty rules without %empty

[bison.git] / TODO

diff --git a/TODO b/TODO
index 2907d992e9707d524ff313775bb3e9aee7ee1f85..bba43c29b28e1c244bbf49ac8def40f66e0329ff 100644 (file)
--- a/TODO
+++ b/TODO
@@ -1,4 +1,28 @@
 * Short term
+** Graphviz display code thoughts
+The code for the --graph option is over two files: print_graph, and
+graphviz. This is because Bison used to also produce VCG graphs, but since
+this is no longer true, maybe we could consider these files for fusion.
+
+An other consideration worth noting is that print_graph.c (correct me if I
+am wrong) should contain generic functions, whereas graphviz.c and other
+potential files should contain just the specific code for that output
+format. It will probably prove difficult to tell if the implementation is
+actually generic whilst only having support for a single format, but it
+would be nice to keep stuff a bit tidier: right now, the construction of the
+bitset used to show reductions is in the graphviz-specific code, and on the
+opposite side we have some use of \l, which is graphviz-specific, in what
+should be generic code.
+
+Little effort seems to have been given to factoring these files and their
+rint{,-xml} counterpart. We would very much like to re-use the pretty format
+of states from .output for the graphs, etc.
+
+Also, the underscore in print_graph.[ch] isn't very fitting considering the
+dashes in the other filenames.
+
+Since graphviz dies on medium-to-big grammars, maybe consider an other tool?
+
 ** push-parser
 Check it too when checking the different kinds of parsers.  And be
 sure to check that the initial-action is performed once per parsing.
@@ -7,21 +31,34 @@ sure to check that the initial-action is performed once per parsing.
 b4_shared_declarations is no longer what it is.  Make it
 b4_parser_declaration for instance.
 
-** glr.cc: %defines
-it should not be mandatory.
+** yychar in lalr1.cc
+There is a large difference bw maint and master on the handling of
+yychar (which was removed in lalr1.cc).  See what needs to be
+back-ported.
+
+
+    /* User semantic actions sometimes alter yychar, and that requires
+       that yytoken be updated with the new translation.  We take the
+       approach of translating immediately before every use of yytoken.
+       One alternative is translating here after every semantic action,
+       but that translation would be missed if the semantic action
+       invokes YYABORT, YYACCEPT, or YYERROR immediately after altering
+       yychar.  In the case of YYABORT or YYACCEPT, an incorrect
+       destructor might then be invoked immediately.  In the case of
+       YYERROR, subsequent parser actions might lead to an incorrect
+       destructor call or verbose syntax error message before the
+       lookahead is translated.  */
+
+    /* Make sure we have latest lookahead translation.  See comments at
+       user semantic actions for why this is necessary.  */
+    yytoken = yytranslate_ (yychar);
 
-** $ and others in epilogue
-A stray $ is a warning in the actions, but an error in the epilogue.
-IMHO, it should not even be a warning in the epilogue.
 
 ** stack.hh
 Get rid of it.  The original idea is nice, but actually it makes
 the code harder to follow, and uselessly different from the other
 skeletons.
 
-** Variable names.
-What should we name `variant' and `lex_symbol'?
-
 ** Get rid of fake #lines [Bison: ...]
 Possibly as simple as checking whether the column number is nonnegative.
 
@@ -48,9 +85,6 @@ since it is no longer bound to a particular parser, it's just a
 ** Rename LR0.cc
 as lr0.cc, why upper case?
 
-** bench several bisons.
-Enhance bench.pl with %b to run different bisons.
-
 * Various
 ** YYERRCODE
 Defined to 256, but not used, not documented.  Probably the token
@@ -114,12 +148,6 @@ really possible?  The test suite does not exercise this case.
 This shows that it would be interesting to manage to install skeleton
 coverage analysis to the test suite.
 
-** Table definitions
-It should be very easy to factor the definition of the various tables,
-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
@@ -245,9 +273,6 @@ Paul notes:
         tokens, either via escapes (e.g., "x\0y") or via a NUL byte in
         the source code.  This should get fixed.
 
-* --graph
-Show reductions.
-
 * Broken options ?
 ** %token-table
 ** Skeleton strategy
@@ -344,7 +369,7 @@ End:
 
 -----
 
-Copyright (C) 2001-2004, 2006, 2008-2012 Free Software Foundation, Inc.
+Copyright (C) 2001-2004, 2006, 2008-2013 Free Software Foundation, Inc.
 
 This file is part of Bison, the GNU Compiler Compiler.