On Wed, Oct 5, 2022 at 10:52 AM Mark Rutland mark.rutland@arm.com wrote:
When KUNIT_EXPECT_EQ() or KUNIT_ASSERT_EQ() log a failure, they log the two values being compared, with numerical values logged in decimal.
In some cases, decimal output is painful to consume, and hexadecimal output would be more helpful. For example, this is the case for tests I'm currently developing for the arm64 insn encoding/decoding code, where comparing two 32-bit instruction opcodes results in output such as:
| # test_insn_add_shifted_reg: EXPECTATION FAILED at arch/arm64/lib/test_insn.c:2791 | Expected obj_insn == gen_insn, but | obj_insn == 2332164128 | gen_insn == 1258422304
To make this easier to consume, this patch logs the values in both decimal and hexadecimal:
| # test_insn_add_shifted_reg: EXPECTATION FAILED at arch/arm64/lib/test_insn.c:2791 | Expected obj_insn == gen_insn, but | obj_insn == 2332164128 (0x8b020020) | gen_insn == 1258422304 (0x4b020020)
As can be seen from the example, having hexadecimal makes it significantly easier for a human to spot which specific bits are incorrect.
Signed-off-by: Mark Rutland mark.rutland@arm.com Cc: Brendan Higgins brendan.higgins@linux.dev Cc: David Gow davidgow@google.com Cc: linux-kselftest@vger.kernel.org Cc: kunit-dev@googlegroups.com
Acked-by: Daniel Latypov dlatypov@google.com
This is definitely something that has irked me as well.
I vaguely feel like this can clutter up the output for things that are just ints, e.g. Expected len == 0, but len == 2 (0x2)
But I can't think of any suggestions that are actually worth doing [1]. And since this feels like a common enough case, I don't think the existing workarounds [2] are sufficiently ergonomic.
So I think always showing the hex makes sense.
[1] E.g. only emitting hex when the number in question is >16, but that feels too magic (also needs more if's). E.g. adding in a macro argument/separate set of macros that always format in hex
[2] can use these to coerce hex output KUNIT_EXPECT_EQ_MSG(test, obj_insn, gen_insn, "obj=0x%llx, gen=0x%llx", obj_insn, gen_insn); KUNIT_EXPECT_PTR_EQ(test, obj_insn, gen_insn);