Updated bison to 2.4.3, this required adding in the recent gnulib patch to binary-io.h from Eric Blake.

sys-devel/bison/bison-2.4.3.bep

@@ -0,0 +1,25 @@
+DESCRIPTION="bison - A yacc-compatible parser generator" 
+HOMEPAGE="http://www.gnu.org/software/bison/bison.html" 
+SRC_URI="http://ftp.gnu.org/gnu/bison/bison-2.4.3.tar.gz"
+CHECKSUM_MD5="ea45c778b36bdc7a720096819e292a73"
+REVISION="2"
+STATUS_HAIKU="stable"
+DEPEND=""
+BUILD {
+	cd bison-2.4.3
+	./configure --prefix=/boot/common --disable-nls
+	make
+}
+
+INSTALL {
+	cd bison-2.4.3
+	make install
+}
+
+TEST {
+	cd bison-2.4.3
+	make check
+}
+
+LICENSE="GNU GPL v3"
+COPYRIGHT="1992-2010 Free Software Foundation, Inc."

sys-devel/bison/patches/bison-2.4.3.patch

@@ -0,0 +1,67 @@
+diff -urN bison-2.4.3/lib/binary-io.h bison-2.4.3-haiku/lib/binary-io.h
+--- bison-2.4.3/lib/binary-io.h	2010-02-06 21:15:26.051118080 +0000
++++ bison-2.4.3-haiku/lib/binary-io.h	2011-01-26 11:15:38.000000000 +0000
+@@ -19,24 +19,13 @@
+ #define _BINARY_H
+ 
+ /* For systems that distinguish between text and binary I/O.
+-   O_BINARY is usually declared in <fcntl.h>. */
++   O_BINARY is guaranteed by the gnulib <fcntl.h>. */
+ #include <fcntl.h>
+ 
+ /* The MSVC7 <stdio.h> doesn't like to be included after '#define fileno ...',
+    so we include it here first.  */
+ #include <stdio.h>
+ 
+-#if !defined O_BINARY && defined _O_BINARY
+-  /* For MSC-compatible compilers.  */
+-# define O_BINARY _O_BINARY
+-# define O_TEXT _O_TEXT
+-#endif
+-#if defined __BEOS__ || defined __HAIKU__
+-  /* BeOS 5 and Haiku have O_BINARY and O_TEXT, but they have no effect.  */
+-# undef O_BINARY
+-# undef O_TEXT
+-#endif
+-
+ /* SET_BINARY (fd);
+    changes the file descriptor fd to perform binary I/O.  */
+ #if O_BINARY
+@@ -58,8 +47,6 @@
+ # endif
+ #else
+   /* On reasonable systems, binary I/O is the default.  */
+-# undef O_BINARY
+-# define O_BINARY 0
+ # define SET_BINARY(fd) /* do nothing */ ((void) 0)
+ #endif
+ 
+diff -urN bison-2.4.3/src/location.c bison-2.4.3-haiku/src/location.c
+--- bison-2.4.3/src/location.c	2010-08-06 00:37:58.001572864 +0000
++++ bison-2.4.3-haiku/src/location.c	2011-01-26 10:23:20.032505856 +0000
+@@ -141,11 +141,11 @@
+   /* Must search in reverse since the file name field may
+    * contain `.' or `:'.  */
+   char *delim = strrchr (loc_str, '.');
+-  aver (delim);
++  aver (delim != NULL);
+   *delim = '\0';
+   bound->column = atoi (delim+1);
+   delim = strrchr (loc_str, ':');
+-  aver (delim);
++  aver (delim != NULL);
+   *delim = '\0';
+   bound->line = atoi (delim+1);
+   bound->file = uniqstr_new (loc_str);
+diff -urN bison-2.4.3/src/muscle_tab.c bison-2.4.3-haiku/src/muscle_tab.c
+--- bison-2.4.3/src/muscle_tab.c	2010-08-06 00:37:58.065011712 +0000
++++ bison-2.4.3-haiku/src/muscle_tab.c	2011-01-26 10:23:20.033030144 +0000
+@@ -338,7 +338,7 @@
+ {
+   location loc;
+   char const *value = muscle_find_const (key);
+-  aver (value);
++  aver (value != NULL);
+   aver (*value == '[');
+   aver (*++value == '[');
+   while (*++value)