1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142

use super::{
    ExecutableTransaction,
    InitialBalances,
    Interpreter,
    RuntimeBalances,
};
use crate::{
    checked_transaction::{
        IntoChecked,
        Ready,
    },
    consts::*,
    context::Context,
    error::InterpreterError,
    prelude::RuntimeError,
    storage::InterpreterStorage,
};
use fuel_asm::RegId;
use fuel_tx::field::ScriptGasLimit;
use fuel_types::Word;

use crate::interpreter::CheckedMetadata;

impl<S, Tx, Ecal> Interpreter<S, Tx, Ecal>
where
    Tx: ExecutableTransaction,
    S: InterpreterStorage,
{
    /// Initialize the VM with a given transaction
    fn init_inner(
        &mut self,
        mut tx: Tx,
        initial_balances: InitialBalances,
        runtime_balances: RuntimeBalances,
        gas_limit: Word,
    ) -> Result<(), RuntimeError<S::DataError>> {
        tx.prepare_init_execute();
        self.tx = tx;

        self.initial_balances = initial_balances.clone();

        self.frames.clear();
        self.receipts.clear();

        // Optimized for memset
        self.registers.iter_mut().for_each(|r| *r = 0);

        self.registers[RegId::ONE] = 1;
        self.registers[RegId::SSP] = 0;

        // Set heap area
        self.registers[RegId::HP] = VM_MAX_RAM;

        // Initialize stack
        macro_rules! push_stack {
            ($v:expr) => {{
                let data = $v;
                let old_ssp = self.registers[RegId::SSP];
                let new_ssp = old_ssp
                    .checked_add(data.len() as Word)
                    .expect("VM initialization data must fit into the stack");
                self.memory.grow_stack(new_ssp)?;
                self.registers[RegId::SSP] = new_ssp;
                self.memory
                    .write_noownerchecks(old_ssp, data.len())
                    .expect("VM initialization data must fit into the stack")
                    .copy_from_slice(data);
            }};
        }

        push_stack!(&*self.transaction().id(&self.chain_id()));

        let base_asset_id = self.interpreter_params.base_asset_id;
        push_stack!(&*base_asset_id);

        runtime_balances.to_vm(self);

        let tx_size = self.transaction().size() as Word;
        self.set_gas(gas_limit);

        push_stack!(&tx_size.to_be_bytes());

        let tx_bytes = self.tx.to_bytes();
        push_stack!(tx_bytes.as_slice());

        self.registers[RegId::SP] = self.registers[RegId::SSP];

        Ok(())
    }
}

impl<S, Tx, Ecal> Interpreter<S, Tx, Ecal>
where
    Tx: ExecutableTransaction,
    S: InterpreterStorage,
{
    /// Initialize the VM for a predicate context
    pub fn init_predicate(
        &mut self,
        context: Context,
        tx: Tx,
        gas_limit: Word,
    ) -> Result<(), InterpreterError<S::DataError>> {
        self.context = context;
        let initial_balances: InitialBalances = Default::default();
        let runtime_balances = initial_balances.clone().try_into()?;
        Ok(self.init_inner(tx, initial_balances, runtime_balances, gas_limit)?)
    }
}

impl<S, Tx, Ecal> Interpreter<S, Tx, Ecal>
where
    S: InterpreterStorage,
    <S as InterpreterStorage>::DataError: From<S::DataError>,
    Tx: ExecutableTransaction,
    <Tx as IntoChecked>::Metadata: CheckedMetadata,
{
    /// Initialize the VM with a given transaction, backed by a storage provider that
    /// allows execution of contract opcodes.
    ///
    /// For predicate estimation and verification, check [`Self::init_predicate`]
    pub fn init_script(
        &mut self,
        ready_tx: Ready<Tx>,
    ) -> Result<(), InterpreterError<S::DataError>> {
        let block_height = self.storage.block_height().map_err(RuntimeError::Storage)?;

        self.context = Context::Script { block_height };

        let (_, checked) = ready_tx.decompose();
        let (tx, metadata): (Tx, Tx::Metadata) = checked.into();

        let gas_limit = tx
            .as_script()
            .map(|script| *script.script_gas_limit())
            .unwrap_or_default();

        let initial_balances = metadata.balances();
        let runtime_balances = initial_balances.try_into()?;
        Ok(self.init_inner(tx, metadata.balances(), runtime_balances, gas_limit)?)
    }
}