From f29f8af3edf5b678f812e36ea4416983467e9189 Mon Sep 17 00:00:00 2001 From: Theophile Ranquet Date: Thu, 31 Jan 2013 12:18:37 +0100 Subject: [PATCH 1/1] todo: update Reformulate and give more details on my thoughts concerning the graphical visualization, and add an entry about a bug in the options processing for warnings as errors. * TODO: Here. --- TODO | 54 ++++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 44 insertions(+), 10 deletions(-) diff --git a/TODO b/TODO index 18c89995..d2e457c9 100644 --- a/TODO +++ b/TODO @@ -1,16 +1,50 @@ * Short term +** Laxism in Bison invocation arguments: +The flag_argmatch functions were meant to be generic. The introduction of +-Werror= in generic code is a bit troublesome, and generates weird +behaviour. Because seeing "error=" causes Bison to match the subsequent +categories with a generic procedure, but on a very specific variable, the +following commands are legal, and equivalent: + +$ bison -Werror=yacc # OK +$ bison --warnings=error=yacc # err, looks very weird? +$ bison -rerror=itemsets # this value of 'report' enum has a value + # of '1 << 1', just like Wyacc +$ bison --report=error=itemsets # (same) +$ bison -ferror=caret # (same) +$ bison --feature=error=caret # (same) + +Basically, writing -rerror={THINGS} or -ferror={FEATURE} is not prohibited, +and results in UB. + +I don't think there is any reason for the user to expect anything out of +these options (this implementation-driven behavior is not documented of +course, as it isn't exactly a feature), so this bug isn't critical but +should be addressed some day nonetheless. + ** Graphviz display code thoughts The code for the --graph option is over two files: print_graph, and -graphviz. I believe 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. - -Little effort factoring seems to have been given to factoring in these files, -and their print-xml and print counterpart. We would very much like to re-use -the pretty format of states from .output in the .dot - -Also, the underscore in print_graph.[ch] isn't very fitting considering -the dashes in the other filenames. +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 -- 2.47.2