Missing array index OOB check

[g-r-a-n-t]

What is wrong?

See the following code:

fe/crates/tests/fixtures/files/arrays.fe

Lines 68 to 102 in 7054185

	// The following tests does not pass due absent runtime check.
	// Obviously this couild also be a compile-time check.
	//
	// contract ArrayIndexOobStatic {
	// pub unsafe fn __call__() {
	// let mut my_array: Array<u256, 4> = [0, 1, 2, 3]
	// evm::sstore(offset: 0, value: my_array[26])
	// }
	// }
	// #test
	// unsafe fn test_array_oob_static() {
	// let mut ctx: Context = Context()
	// let array_index_oob: ArrayIndexOobStatic = ArrayIndexOobStatic.create(ctx, value: 0)
	// let expected_revert_data: Array<u8, 36> = [78, 72, 123, 113, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 50]
	// // verify that the call reverts
	// assert evm::call(
	// gas: CALL_GAS,
	// addr: address(array_index_oob),
	// value: 0,
	// input_offset: 0,
	// input_len: 0,
	// output_offset: FREE_MEM_PTR,
	// output_len: 36
	// ) == 0
	// // check the revert data
	// let mut offset: u256 = FREE_MEM_PTR
	// for expected_byte in expected_revert_data {
	// assert evm::shr(248, evm::mload(offset)) == expected_byte
	// offset += 1
	// }
	// }

How can it be fixed

Add a compile-time check for array indices.