The command forc build
compiles your Sway code and generates the bytecode: the binary code that the Fuel Virtual Machine will interpret. For instance, the smart contract below:
contract;
abi MyContract {
fn test_function() -> bool;
}
impl MyContract for Contract {
fn test_function() -> bool {
true
}
}
After forc build
, will have a binary file that contains:
$ cat out/release/my-test.bin
G4]�]D`I]C�As@
6]C�$@!QK%
This seems very unreadable! But, forc
has a nice interpreter for this bytecode: forc parse-bytecode
, which will interpret that binary data and output the equivalent FuelVM assembly:
$ forc parse-bytecode out/release/my-test.bin
half-word byte op raw notes
0 0 JI(4) 90 00 00 04 jump to byte 16
1 4 NOOP 47 00 00 00
2 8 Undefined 00 00 00 00 data section offset lo (0)
3 12 Undefined 00 00 00 34 data section offset hi (52)
4 16 LW(63, 12, 1) 5d fc c0 01
5 20 ADD(63, 63, 12) 10 ff f3 00
6 24 LW(17, 6, 73) 5d 44 60 49
7 28 LW(16, 63, 1) 5d 43 f0 01
8 32 EQ(16, 17, 16) 13 41 14 00
9 36 JNZI(16, 11) 73 40 00 0b conditionally jump to byte 44
10 40 RVRT(0) 36 00 00 00
11 44 LW(16, 63, 0) 5d 43 f0 00
12 48 RET(16) 24 40 00 00
13 52 Undefined 00 00 00 00
14 56 Undefined 00 00 00 01
15 60 Undefined 00 00 00 00
16 64 XOR(20, 27, 53) 21 51 bd 4b
If you want to deploy your smart contract using the SDK, this binary file is important; it's what we'll be sending to the FuelVM in a transaction.