mirror of
https://git.savannah.gnu.org/git/bison.git
synced 2026-03-09 12:23:04 +00:00
todo: update
* TODO: Schedule some features for 3.6. Remove obsolete stuff.
This commit is contained in:
Akim Demaille
141
TODO
141
TODO
@@ -1,4 +1,4 @@
|
||||
* Bison 3.5
|
||||
* Bison 3.6
|
||||
** doc
|
||||
I feel its ugly to use the GNU style to declare functions in the doc. It
|
||||
generates tons of white space in the page, and may contribute to bad page
|
||||
@@ -50,12 +50,72 @@ syntax error, unexpected $end, expecting ↦ or 🎅🐃 or '\n'
|
||||
While at it, we should stop using "$end" by default, in favor of "end of
|
||||
file", or "end of input", whatever. See how lalr1.java does that.
|
||||
|
||||
** consistency
|
||||
token vs terminal, variable vs non terminal.
|
||||
|
||||
** Stop indentation in diagnostics
|
||||
Before Bison 2.7, we printed "flatly" the dependencies in long diagnostics:
|
||||
|
||||
input.y:2.7-12: %type redeclaration for exp
|
||||
input.y:1.7-12: previous declaration
|
||||
|
||||
In Bison 2.7, we indented them
|
||||
|
||||
input.y:2.7-12: error: %type redeclaration for exp
|
||||
input.y:1.7-12: previous declaration
|
||||
|
||||
Later we quoted the source in the diagnostics, and today we have:
|
||||
|
||||
/tmp/foo.y:1.12-14: warning: symbol FOO redeclared [-Wother]
|
||||
1 | %token FOO FOO
|
||||
| ^~~
|
||||
/tmp/foo.y:1.8-10: previous declaration
|
||||
1 | %token FOO FOO
|
||||
| ^~~
|
||||
|
||||
The indentation is no longer helping. We should probably get rid of it, or
|
||||
maybe keep it only when -fno-caret. GCC displays this as a "note":
|
||||
|
||||
$ g++-mp-9 -Wall /tmp/foo.c -c
|
||||
/tmp/foo.c:1:10: error: redefinition of 'int foo'
|
||||
1 | int foo, foo;
|
||||
| ^~~
|
||||
/tmp/foo.c:1:5: note: 'int foo' previously declared here
|
||||
1 | int foo, foo;
|
||||
| ^~~
|
||||
|
||||
Likewise for Clang, contrary to what I believed (because "note:" is written
|
||||
in black, so it doesn't show in my terminal :-)
|
||||
|
||||
$ clang++-mp-8.0 -Wall /tmp/foo.c -c
|
||||
clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Wdeprecated]
|
||||
/tmp/foo.c:1:10: error: redefinition of 'foo'
|
||||
int foo, foo;
|
||||
^
|
||||
/tmp/foo.c:1:5: note: previous definition is here
|
||||
int foo, foo;
|
||||
^
|
||||
1 error generated.
|
||||
|
||||
See also the item "Complaint submessage indentation" below.
|
||||
|
||||
** api.token.raw
|
||||
Maybe we should exhibit the YYUNDEFTOK token. It could also be assigned a
|
||||
semantic value so that yyerror could be used to report invalid lexemes.
|
||||
See also the item "$undefined" below.
|
||||
|
||||
* Bison 3.6
|
||||
** C++
|
||||
Move to int everywhere instead of unsigned? stack_size, etc. The parser
|
||||
itself uses int (for yylen for instance), yet stack is based on size_t.
|
||||
|
||||
Maybe locations should also move to ints.
|
||||
|
||||
Paul Eggert already covered most of this. But before publishing these
|
||||
changes, we need to ask our C++ users if they agree with that change, or if
|
||||
we need some migration path. Could be a %define variable, or simply
|
||||
%require "3.5".
|
||||
|
||||
* Bison 3.7
|
||||
** Unit rules / Injection rules (Akim Demaille)
|
||||
Maybe we could expand unit rules (or "injections", see
|
||||
https://homepages.cwi.nl/~daybuild/daily-books/syntax/2-sdf/sdf.html), i.e.,
|
||||
@@ -137,52 +197,6 @@ $ ./tests/testsuite -l | grep errors | sed q
|
||||
** Get rid of YYPRINT and b4_toknum
|
||||
Besides yytoknum is wrong when api.token.raw is defined.
|
||||
|
||||
** Stop indentation in diagnostics
|
||||
Before Bison 2.7, we printed "flatly" the dependencies in long diagnostics:
|
||||
|
||||
input.y:2.7-12: %type redeclaration for exp
|
||||
input.y:1.7-12: previous declaration
|
||||
|
||||
In Bison 2.7, we indented them
|
||||
|
||||
input.y:2.7-12: error: %type redeclaration for exp
|
||||
input.y:1.7-12: previous declaration
|
||||
|
||||
Later we quoted the source in the diagnostics, and today we have:
|
||||
|
||||
/tmp/foo.y:1.12-14: warning: symbol FOO redeclared [-Wother]
|
||||
1 | %token FOO FOO
|
||||
| ^~~
|
||||
/tmp/foo.y:1.8-10: previous declaration
|
||||
1 | %token FOO FOO
|
||||
| ^~~
|
||||
|
||||
The indentation is no longer helping. We should probably get rid of it, or
|
||||
maybe keep it only when -fno-caret. GCC displays this as a "note":
|
||||
|
||||
$ g++-mp-9 -Wall /tmp/foo.c -c
|
||||
/tmp/foo.c:1:10: error: redefinition of 'int foo'
|
||||
1 | int foo, foo;
|
||||
| ^~~
|
||||
/tmp/foo.c:1:5: note: 'int foo' previously declared here
|
||||
1 | int foo, foo;
|
||||
| ^~~
|
||||
|
||||
Likewise for Clang, contrary to what I believed (because "note:" is written
|
||||
in black, so it doesn't show in my terminal :-)
|
||||
|
||||
$ clang++-mp-8.0 -Wall /tmp/foo.c -c
|
||||
clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Wdeprecated]
|
||||
/tmp/foo.c:1:10: error: redefinition of 'foo'
|
||||
int foo, foo;
|
||||
^
|
||||
/tmp/foo.c:1:5: note: previous definition is here
|
||||
int foo, foo;
|
||||
^
|
||||
1 error generated.
|
||||
|
||||
See also the item "Complaint submessage indentation" below.
|
||||
|
||||
** Better design for diagnostics
|
||||
The current implementation of diagnostics is adhoc, it grew organically. It
|
||||
works as a series of calls to several functions, with dependency of the
|
||||
@@ -217,20 +231,6 @@ page:
|
||||
|
||||
https://gcc.gnu.org/onlinedocs/gcc/Diagnostic-Message-Formatting-Options.html
|
||||
|
||||
** consistency
|
||||
token vs terminal, variable vs non terminal.
|
||||
|
||||
** C++
|
||||
Move to int everywhere instead of unsigned? stack_size, etc. The parser
|
||||
itself uses int (for yylen for instance), yet stack is based on size_t.
|
||||
|
||||
Maybe locations should also move to ints.
|
||||
|
||||
Paul Eggert already covered most of this. But before publishing these
|
||||
changes, we need to ask our C++ users if they agree with that change, or if
|
||||
we need some migration path. Could be a %define variable, or simply
|
||||
%require "3.5".
|
||||
|
||||
** 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
|
||||
@@ -603,23 +603,6 @@ to bison. If you're interested, I'll work on a patch.
|
||||
* Better graphics
|
||||
Equip the parser with a means to create the (visual) parse tree.
|
||||
|
||||
* Complaint submessage indentation.
|
||||
We already have an implementation that works fairly well for named
|
||||
reference messages, but it would be nice to use it consistently for all
|
||||
submessages from Bison. For example, the "previous definition"
|
||||
submessage or the list of correct values for a %define variable might
|
||||
look better with indentation.
|
||||
|
||||
However, the current implementation makes the assumption that the
|
||||
location printed on the first line is not usually much shorter than the
|
||||
locations printed on the submessage lines that follow. That assumption
|
||||
may not hold true as often for some kinds of submessages especially if
|
||||
we ever support multiple grammar files.
|
||||
|
||||
Here's a proposal for how a new implementation might look:
|
||||
|
||||
http://lists.gnu.org/archive/html/bison-patches/2009-09/msg00086.html
|
||||
|
||||
|
||||
Local Variables:
|
||||
mode: outline
|
||||
|
||||
Reference in New Issue
Block a user