Remove from repo.

[bison.git] / TODO

diff --git a/TODO b/TODO
index e5c3cc153d0ffb43be4cd2cfc657edd323977df8..cfbca2a0cb59113df7ae457835a6dcb8c9131f53 100644 (file)
--- a/TODO
+++ b/TODO
@@ -1,5 +1,38 @@
 -*- outline -*-
 
+* Coding system independence
+Paul notes: 
+
+       Currently Bison assumes 8-bit bytes (i.e. that UCHAR_MAX is
+       255).  It also assumes that the 8-bit character encoding is
+       the same for the invocation of 'bison' as it is for the
+       invocation of 'cc', but this is not necessarily true when
+       people run bison on an ASCII host and then use cc on an EBCDIC
+       host.  I don't think these topics are worth our time
+       addressing (unless we find a gung-ho volunteer for EBCDIC or
+       PDP-10 ports :-) but they should probably be documented
+       somewhere.
+
+* Using enums instead of int for tokens.
+Paul suggests:
+
+   #ifndef YYTOKENTYPE
+   # if defined (__STDC__) || defined (__cplusplus)
+      /* Put the tokens into the symbol table, so that GDB and other debuggers
+         know about them.  */
+      enum yytokentype {
+        FOO = 256,
+        BAR,
+        ...
+      };
+      /* POSIX requires `int' for tokens in interfaces.  */
+   #  define YYTOKENTYPE int
+   # endif
+   #endif
+   #define FOO 256
+   #define BAR 257
+   ...
+
 * Unit rules
 Maybe we could expand unit rules, i.e., transform
 
@@ -14,16 +47,44 @@ into
 when there are no actions.  This can significantly speed up some
 grammars.
 
-* Huge Grammars
-Currently, not only is Bison unable to handle huge grammars because of
-internal limitations, but the test `big triangle' also demonstrates
-that it can produce SEGVing executables!  Push the limit beyond 124,
-and have a core dump.  Be my guest: fix this!
+* Stupid error messages
+An example shows it easily:
+
+src/bison/tests % ./testsuite -k calc,location,error-verbose -l
+GNU Bison 1.49a test suite test groups:
+
+ NUM: FILENAME:LINE      TEST-GROUP-NAME
+      KEYWORDS
+
+  51: calc.at:440        Calculator --locations --yyerror-verbose
+  52: calc.at:442        Calculator --defines --locations --name-prefix=calc --verbose --yacc --yyerror-verbose
+  54: calc.at:445        Calculator --debug --defines --locations --name-prefix=calc --verbose --yacc --yyerror-verbose
+src/bison/tests % ./testsuite 51 -d
+## --------------------------- ##
+## GNU Bison 1.49a test suite. ##
+## --------------------------- ##
+ 51: calc.at:440       ok
+## ---------------------------- ##
+## All 1 tests were successful. ##
+## ---------------------------- ##
+src/bison/tests % cd ./testsuite.dir/51
+tests/testsuite.dir/51 % echo "()" | ./calc
+1.2-1.3: parse error, unexpected ')', expecting error or "number" or '-' or '('
 
 * read_pipe.c
 This is not portable to DOS for instance.  Implement a more portable
 scheme.  Sources of inspiration include GNU diff, and Free Recode.
 
+* Memory leaks in the generator
+A round of memory leak clean ups would be most welcome.  Dmalloc,
+Checker GCC, Electric Fence, or Valgrind: you chose your tool.
+
+* Memory leaks in the parser
+The same applies to the generated parsers.  In particular, this is
+critical for user data: when aborting a parsing, when handling the
+error token etc., we often throw away yylval without giving a chance
+of cleaning it up to the user.
+
 * NEWS
 Sort from 1.31 NEWS.
 
@@ -147,3 +208,22 @@ You like?
 * input synclines
 Some users create their foo.y files, and equip them with #line.  Bison
 should recognize these, and preserve them.
+
+* BTYacc
+See if we can integrate backtracking in Bison.  Contact the BTYacc
+maintainers.
+
+* Automaton report
+Display more clearly the lookaheads for each item.
+
+* RR conflicts
+See if we can use precedence between rules to solve RR conflicts.  See
+what POSIX says.
+
+* Precedence
+It is unfortunate that there is a total order for precedence.  It
+makes it impossible to have modular precedence information.  We should
+move to partial orders.
+
+* Parsing grammars
+Rewrite the reader in Bison.