Hitherto, the kernel has required constant values for the xor and mask
attributes of boolean bitwise expressions. This has meant that the
righthand argument of a boolean binop must be constant. Now the kernel
supports passing mask and xor via registers, we can relax this
restriction.
Signed-off-by: Jeremy Sowden <jeremy@xxxxxxxxxx>
---
src/evaluate.c | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)
diff --git a/src/evaluate.c b/src/evaluate.c
index 4a23b231c74d..1db175007c2d 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -1135,7 +1135,7 @@ static int expr_evaluate_bitwise(struct eval_ctx *ctx, struct expr **expr)
op->byteorder = left->byteorder;
op->len = left->len;
- if (expr_is_constant(left))
+ if (expr_is_constant(left) && expr_is_constant(op->right))
return constant_binop_simplify(ctx, expr);
return 0;
}
@@ -1179,23 +1179,22 @@ static int expr_evaluate_binop(struct eval_ctx *ctx, struct expr **expr)
"for %s expressions",
sym, expr_name(left));
- if (!expr_is_constant(right))
- return expr_binary_error(ctx->msgs, right, op,
- "Right hand side of binary operation "
- "(%s) must be constant", sym);
-
- if (!expr_is_singleton(right))
- return expr_binary_error(ctx->msgs, left, op,
- "Binary operation (%s) is undefined "
- "for %s expressions",
- sym, expr_name(right));
-
/* The grammar guarantees this */
assert(expr_basetype(left) == expr_basetype(right));
switch (op->op) {
case OP_LSHIFT:
case OP_RSHIFT:
+ if (!expr_is_constant(right))
+ return expr_binary_error(ctx->msgs, right, op,
+ "Right hand side of binary operation "
+ "(%s) must be constant", sym);
+
+ if (!expr_is_singleton(right))
+ return expr_binary_error(ctx->msgs, left, op,
+ "Binary operation (%s) is undefined "
+ "for %s expressions",
+ sym, expr_name(right));
return expr_evaluate_shift(ctx, expr);
case OP_AND:
case OP_XOR:
--
2.25.1
