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use super::*;
impl ExecutionContext {
/// Task #50: mask a BigInt bitwise result to 256 bits and encode as a
/// fixed-width (up to 32-byte) little-endian ByteArray. Returns narrow
/// Integer for values that fit in i64 to preserve existing narrow
/// comparison paths; wider values return a signed-LE payload so that
/// subsequent decode via `coerce_item_to_bigint` (which uses
/// `BigInt::from_signed_bytes_le`) round-trips correctly. Without the
/// sign-padding byte, a positive magnitude whose MSB byte has its high
/// bit set (e.g. `0x80 * 2^240` has magnitude-MSB `0x80`) would decode
/// as a negative value — the Task #118 fuzz harness
/// `batch51_aa4_bytes_to_bytes32_bitwise_shl_or_assembly` hits this case
/// when the input byte is `>= 0x80` and the shift places it at bit
/// position ≡ 7 (mod 8).
fn u256_bigint_to_stack_item(value: num_bigint::BigInt) -> StackItem {
Self::u256_twos_complement_item(value)
}
/// Encode a 256-bit value as the conformant NeoVM **32-byte two's-complement**
/// Integer (the value mod 2^256, mapped into `[-2^255, 2^255-1]`; bit 255 set
/// => negative). This matches what a real Neo node computes for bitwise/shift
/// results and lets the software uint256 routines (`cli/bytecode/uint256_ops.rs`)
/// execute correctly here as on-chain.
pub(crate) fn u256_twos_complement_item(value: num_bigint::BigInt) -> StackItem {
use num_bigint::BigInt;
let one: BigInt = BigInt::from(1);
let two256: BigInt = &one << 256u32;
let mask: BigInt = &two256 - &one;
let masked: BigInt = value & &mask; // value mod 2^256, in [0, 2^256)
let sign_min: BigInt = &one << 255u32; // 2^255
let signed: BigInt = if masked >= sign_min {
&masked - &two256
} else {
masked
};
// Negative (high bit set) => emit a fixed 32-byte two's-complement
// ByteArray so the value stays a distinguishable 256-bit word (see
// `bigint_to_stack_item`); non-negative small values collapse to a narrow
// Integer.
let bytes = signed.to_signed_bytes_le();
if signed.sign() == num_bigint::Sign::Minus {
let mut buf = vec![0xFFu8; 32];
buf[..bytes.len()].copy_from_slice(&bytes);
return StackItem::byte_array(buf);
}
if let Ok(n) = i64::try_from(signed.clone()) {
return StackItem::Integer(n);
}
StackItem::byte_array(bytes)
}
pub(crate) fn bitwise_not(&self, value: StackItem) -> Result<StackItem, RuntimeError> {
// Task #50: narrow scalars preserve existing i64/u64 semantics; wide
// ByteArray operands route through BigInt and mask to 256 bits so
// `~uint256(x)` returns `u256::MAX - x` instead of `!(x as u64)`.
match value {
StackItem::Integer(v) => Ok(StackItem::Integer(!v)),
StackItem::UnsignedInteger(v) => Ok(StackItem::UnsignedInteger(!v)),
StackItem::ByteArray(_) => {
let x = self.coerce_item_to_bigint(&value).ok_or_else(|| {
RuntimeError::ExecutionError {
message: "Invalid operand for bitwise NOT".to_string(),
}
})?;
Ok(Self::u256_bigint_to_stack_item(!x))
}
_ => Err(RuntimeError::ExecutionError {
message: "Invalid operand for bitwise NOT".to_string(),
}),
}
}
pub(crate) fn bitwise_and(
&self,
a: StackItem,
b: StackItem,
) -> Result<StackItem, RuntimeError> {
// Task #50: wide ByteArray pair routes through BigInt; other cases
// keep their pre-existing narrow semantics for compat with the 137
// passing fuzz tests.
if self.cmp_needs_bigint_path(&a, &b) {
let x = self
.coerce_item_to_bigint(&a)
.ok_or_else(|| RuntimeError::ExecutionError {
message: "Invalid operands for bitwise AND".to_string(),
})?;
let y = self
.coerce_item_to_bigint(&b)
.ok_or_else(|| RuntimeError::ExecutionError {
message: "Invalid operands for bitwise AND".to_string(),
})?;
return Ok(Self::u256_bigint_to_stack_item(x & y));
}
match (a, b) {
(StackItem::Integer(x), StackItem::Integer(y)) => Ok(StackItem::Integer(x & y)),
(StackItem::UnsignedInteger(x), StackItem::UnsignedInteger(y)) => {
Ok(StackItem::UnsignedInteger(x & y))
}
// Task #170: mixed signed/unsigned narrow-integer arms. This case
// arises when a `uint32(block.number)` cast (emits `value & 0xFFFFFFFF`)
// runs against a runtime-sourced `UnsignedInteger` (block.number)
// with a compiler-pushed `Integer` mask — without these arms the
// packed-struct push (mapping → dynamic-array of struct) faults
// with "Invalid operands for bitwise AND" mid-push. `i64 as u64`
// preserves the bit pattern (two's complement view), which is the
// correct semantics for a bitwise operation.
(StackItem::UnsignedInteger(x), StackItem::Integer(y)) => {
Ok(StackItem::UnsignedInteger(x & (y as u64)))
}
(StackItem::Integer(x), StackItem::UnsignedInteger(y)) => {
Ok(StackItem::UnsignedInteger((x as u64) & y))
}
// Handle Boolean types - convert to integers for bitwise operations
(StackItem::Boolean(x), StackItem::Boolean(y)) => Ok(StackItem::Boolean(x && y)),
(StackItem::Boolean(x), StackItem::Integer(y)) => {
let x_int = if x { 1i64 } else { 0i64 };
Ok(StackItem::Integer(x_int & y))
}
(StackItem::Integer(x), StackItem::Boolean(y)) => {
let y_int = if y { 1i64 } else { 0i64 };
Ok(StackItem::Integer(x & y_int))
}
(StackItem::Boolean(x), StackItem::UnsignedInteger(y)) => {
let x_int = if x { 1u64 } else { 0u64 };
Ok(StackItem::UnsignedInteger(x_int & y))
}
(StackItem::UnsignedInteger(x), StackItem::Boolean(y)) => {
let y_int = if y { 1u64 } else { 0u64 };
Ok(StackItem::UnsignedInteger(x & y_int))
}
// Handle Null as zero/false
(StackItem::Null, StackItem::Integer(_)) => Ok(StackItem::Integer(0)),
(StackItem::Integer(_), StackItem::Null) => Ok(StackItem::Integer(0)),
(StackItem::Null, StackItem::UnsignedInteger(_)) => Ok(StackItem::UnsignedInteger(0)),
(StackItem::UnsignedInteger(_), StackItem::Null) => Ok(StackItem::UnsignedInteger(0)),
(StackItem::Null, StackItem::Boolean(_)) => Ok(StackItem::Boolean(false)),
(StackItem::Boolean(_), StackItem::Null) => Ok(StackItem::Boolean(false)),
(StackItem::Null, StackItem::Null) => Ok(StackItem::Integer(0)),
// Handle ByteArray - convert to integer (little-endian)
(StackItem::ByteArray(ref x), StackItem::Integer(y)) => {
let x_bytes = x.borrow();
let x_int = Self::bytes_to_i64_le(&x_bytes);
Ok(StackItem::Integer(x_int & y))
}
(StackItem::Integer(x), StackItem::ByteArray(ref y)) => {
let y_bytes = y.borrow();
let y_int = Self::bytes_to_i64_le(&y_bytes);
Ok(StackItem::Integer(x & y_int))
}
// Task #170: narrow-ByteArray × UnsignedInteger symmetric arms.
// Mirrors the (ByteArray, Integer) / (Integer, ByteArray) pair
// above — required when a mask is staged as a UnsignedInteger
// (e.g. when it matches a PUSHINT that landed in the unsigned
// narrow path) alongside a narrow serialized-slot read.
(StackItem::ByteArray(ref x), StackItem::UnsignedInteger(y)) => {
let x_bytes = x.borrow();
let x_u = Self::bytes_to_i64_le(&x_bytes) as u64;
Ok(StackItem::UnsignedInteger(x_u & y))
}
(StackItem::UnsignedInteger(x), StackItem::ByteArray(ref y)) => {
let y_bytes = y.borrow();
let y_u = Self::bytes_to_i64_le(&y_bytes) as u64;
Ok(StackItem::UnsignedInteger(x & y_u))
}
(StackItem::ByteArray(ref x), StackItem::ByteArray(ref y)) => {
let x_bytes = x.borrow();
let y_bytes = y.borrow();
let x_int = Self::bytes_to_i64_le(&x_bytes);
let y_int = Self::bytes_to_i64_le(&y_bytes);
Ok(StackItem::Integer(x_int & y_int))
}
_ => Err(RuntimeError::ExecutionError {
message: "Invalid operands for bitwise AND".to_string(),
}),
}
}
pub(crate) fn bitwise_or(&self, a: StackItem, b: StackItem) -> Result<StackItem, RuntimeError> {
// Task #50: accept ByteArray operands by routing through BigInt with a
// 256-bit mask, so `uint256(2^63) | uint256(1)` no longer panics.
if matches!(a, StackItem::ByteArray(_)) || matches!(b, StackItem::ByteArray(_)) {
let x = self
.coerce_item_to_bigint(&a)
.ok_or_else(|| RuntimeError::ExecutionError {
message: "Invalid operands for bitwise OR".to_string(),
})?;
let y = self
.coerce_item_to_bigint(&b)
.ok_or_else(|| RuntimeError::ExecutionError {
message: "Invalid operands for bitwise OR".to_string(),
})?;
return Ok(Self::u256_bigint_to_stack_item(x | y));
}
match (a, b) {
(StackItem::Integer(x), StackItem::Integer(y)) => Ok(StackItem::Integer(x | y)),
(StackItem::UnsignedInteger(x), StackItem::UnsignedInteger(y)) => {
Ok(StackItem::UnsignedInteger(x | y))
}
_ => Err(RuntimeError::ExecutionError {
message: "Invalid operands for bitwise OR".to_string(),
}),
}
}
pub(crate) fn bitwise_xor(
&self,
a: StackItem,
b: StackItem,
) -> Result<StackItem, RuntimeError> {
// Task #50: accept ByteArray operands via the BigInt path with a
// 256-bit mask, matching the new OR/NOT semantics.
if matches!(a, StackItem::ByteArray(_)) || matches!(b, StackItem::ByteArray(_)) {
let x = self
.coerce_item_to_bigint(&a)
.ok_or_else(|| RuntimeError::ExecutionError {
message: "Invalid operands for bitwise XOR".to_string(),
})?;
let y = self
.coerce_item_to_bigint(&b)
.ok_or_else(|| RuntimeError::ExecutionError {
message: "Invalid operands for bitwise XOR".to_string(),
})?;
return Ok(Self::u256_bigint_to_stack_item(x ^ y));
}
match (a, b) {
(StackItem::Integer(x), StackItem::Integer(y)) => Ok(StackItem::Integer(x ^ y)),
(StackItem::UnsignedInteger(x), StackItem::UnsignedInteger(y)) => {
Ok(StackItem::UnsignedInteger(x ^ y))
}
_ => Err(RuntimeError::ExecutionError {
message: "Invalid operands for bitwise XOR".to_string(),
}),
}
}
/// True when the LHS is a wide ByteArray (>8 bytes) that would otherwise
/// be truncated by the narrow i64/u64 shift path. Task #H4.
fn shift_lhs_is_wide(item: &StackItem) -> bool {
matches!(item, StackItem::ByteArray(bytes) if bytes.borrow().len() > 8)
}
pub(crate) fn shift_left(
&self,
value: StackItem,
shift: StackItem,
) -> Result<StackItem, RuntimeError> {
let amount = self.extract_shift_amount(shift)?;
// Task #H4: route through BigInt when either (a) LHS is a wide
// ByteArray (would truncate to low 8 bytes), or (b) amount >= 64
// (result needs more than 64 bits even for narrow 1-bit LHS like
// `uint256(1) << 128`). Reuses the Task #50 BigInt infrastructure
// so results wider than i64 round-trip as ByteArray (u256 LE) and
// `decode_uint_le` on return reads back the full value.
if amount >= 256 {
// EIP-145: shift >= operand width silently produces 0.
return Ok(Self::u256_bigint_to_stack_item(num_bigint::BigInt::from(0)));
}
if Self::shift_lhs_is_wide(&value) || amount >= 64 {
let x =
self.coerce_item_to_bigint(&value)
.ok_or_else(|| RuntimeError::ExecutionError {
message: "Invalid operands for shift left".to_string(),
})?;
return Ok(Self::u256_bigint_to_stack_item(x << amount));
}
match value {
StackItem::Integer(v) => Ok(StackItem::Integer(v.wrapping_shl(amount))),
StackItem::UnsignedInteger(v) => Ok(StackItem::UnsignedInteger(v.wrapping_shl(amount))),
_ => Err(RuntimeError::ExecutionError {
message: "Invalid operands for shift left".to_string(),
}),
}
}
pub(crate) fn shift_right(
&self,
value: StackItem,
shift: StackItem,
) -> Result<StackItem, RuntimeError> {
let amount = self.extract_shift_amount(shift)?;
// Task #H4: route through BigInt when LHS is a wide ByteArray so
// `uint256 x = (1 << 65) - 1; x >> 64` produces 1 instead of
// faulting. Narrow scalars with `amount >= 64` already correctly
// produce 0 for i64 (all bits shifted out), so keep the fast path.
if amount >= 256 {
return Ok(Self::u256_bigint_to_stack_item(num_bigint::BigInt::from(0)));
}
if Self::shift_lhs_is_wide(&value) {
let x =
self.coerce_item_to_bigint(&value)
.ok_or_else(|| RuntimeError::ExecutionError {
message: "Invalid operands for shift right".to_string(),
})?;
return Ok(Self::u256_bigint_to_stack_item(x >> amount));
}
if amount >= 64 {
return match value {
// Arithmetic shift: a NEGATIVE narrow integer sign-extends to all
// ones (-1), not 0. The software uint256 routines rely on this
// (`(a >> 128)` must reproduce the high limb of a two's-complement
// value even when `a` fits in i64, e.g. `-2`).
StackItem::Integer(v) => Ok(StackItem::Integer(if v < 0 { -1 } else { 0 })),
StackItem::UnsignedInteger(_) => Ok(StackItem::UnsignedInteger(0)),
_ => Err(RuntimeError::ExecutionError {
message: "Invalid operands for shift right".to_string(),
}),
};
}
match value {
StackItem::Integer(v) => Ok(StackItem::Integer(v.wrapping_shr(amount))),
StackItem::UnsignedInteger(v) => Ok(StackItem::UnsignedInteger(v.wrapping_shr(amount))),
_ => Err(RuntimeError::ExecutionError {
message: "Invalid operands for shift right".to_string(),
}),
}
}
fn extract_shift_amount(&self, item: StackItem) -> Result<u32, RuntimeError> {
// Per EIP-145 (adopted by Solidity 0.8.x), a shift amount >= the
// operand's bit-width silently produces 0 rather than faulting.
// Neo DevPack for Solidity's widest scalar is uint256, so we clamp any
// out-of-range non-negative shift amount to 256. Callers
// (`shift_left`/`shift_right`) already short-circuit to 0 once the
// amount exceeds their operand width, so the sentinel flows through
// unchanged. Task #33.
match item {
StackItem::Integer(v) => {
if v < 0 {
Err(RuntimeError::ExecutionError {
message: "Shift amount must be non-negative".to_string(),
})
} else if v > 255 {
Ok(256)
} else {
Ok(v as u32)
}
}
StackItem::UnsignedInteger(v) => {
if v > 255 {
Ok(256)
} else {
Ok(v as u32)
}
}
_ => Err(RuntimeError::ExecutionError {
message: "Invalid shift amount".to_string(),
}),
}
}
/// Convert a byte array to i64 using little-endian encoding
/// Empty arrays return 0, arrays longer than 8 bytes are truncated
fn bytes_to_i64_le(bytes: &[u8]) -> i64 {
if bytes.is_empty() {
return 0;
}
let mut result: i64 = 0;
for (i, &byte) in bytes.iter().take(8).enumerate() {
result |= (byte as i64) << (i * 8);
}
// Sign extend if the original value was negative (high bit set in last byte)
if bytes.len() <= 8 && !bytes.is_empty() {
let last_byte = bytes[bytes.len().min(8) - 1];
if last_byte & 0x80 != 0 && bytes.len() < 8 {
// Sign extend
for i in bytes.len()..8 {
result |= 0xFFi64 << (i * 8);
}
}
}
result
}
}