Whereas I thought that the inability of llvm-gcc to chew pine was due to bug 6,
apparently fixing it was not enough. Here's a test case reduced from addrbook.c
in pine-4.58:

struct pine {
    unsigned read_predicted:1;
    char cur_folder[4000];
    int dlevel;
};

extern struct pine *ps_global;
void dump_some_debugging(char *message) {
   ps_global->dlevel = 1;
}

I thought I already filed this as a bug, but I can't find it. If you do, feel
free to mark this as duplicate.

I'm not terribly suprised.  The bitfield handling code is quite fragile and due
for a rewrite.  However, doing this will be a destabilizing change which I do
not want to do at this point.  This bug should be fixable though.  :)

-Chris

Another testcase:

struct face_cachel {
  unsigned int reverse :1;
  unsigned char font_specified[1];
};

void
ensure_face_cachel_contains_charset (struct face_cachel *cachel) {
  cachel->font_specified[0] = 0;
}

The second testcase below is fixed by this patch:

$ diff -u llvm-expand.c~ llvm-expand.c
--- llvm-expand.c~      2003-11-19 18:25:37.000000000 -0600
+++ llvm-expand.c       2003-11-20 12:59:12.000000000 -0600
@@ -4588,8 +4588,7 @@
     llvm_type *Op0Ty = llvm_type_get_from_tree(TREE_TYPE(TREE_OPERAND(exp, 0)));
 
     if (llvm_type_is_composite(Op0Ty)) {
-      llvm_value *Op0 = llvm_expand_lvalue_expr(Fn, TREE_OPERAND(exp, 0),
-                                                BitStart, BitSize);
+      llvm_value *Op0 = llvm_expand_lvalue_expr(Fn, TREE_OPERAND(exp, 0), 0, 0);
       llvm_value *Op1 = llvm_expand_expr(Fn, TREE_OPERAND(exp, 1), 0);
       Op1 = cast_if_type_not_equal(Fn, Op1, LongTy);
       Result = append_inst(Fn, create_gep3(Op0, llvm_constant_long_0, Op1));
@@ -4655,7 +4654,7 @@
       /* If this is accessing a union element, we can go ahead and cast the
        *  pointer to the desired type now.
        */
-      if (ActualOffset == Offset && Size > ActualSize) {
+      if (ActualOffset == Offset && ResultElTy != FieldDeclTy) {
         assert((ActualSize & 7) == 0 && (Size & 7) == 0 &&
                "Illegal union field reference!");
         Result = cast_if_type_not_equal(Fn, Op0,

... and is tested by CFrontend/2003-11-20-Bitfields.c

The first testcase in this patch is HELPED by this patch, but not fixed
completely.  The rest of the fix falls under the guise of Bug 82.

-Chris