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import { task } from 'hardhat/config'
import layoutLock from '../layout-lock.json'
/**
* Parses out variable info from the variable structure in standard compiler json output.
*
* @param variable Variable structure from standard compiler json output.
* @returns Parsed variable info.
*/
const parseVariableInfo = (
variable: any
): {
name: string
slot: number
offset: number
length: number
} => {
// Figure out the length of the variable.
let variableLength: number
if (variable.type.startsWith('t_mapping')) {
variableLength = 32
} else if (variable.type.startsWith('t_uint')) {
variableLength = variable.type.match(/uint([0-9]+)/)?.[1] / 8
} else if (variable.type.startsWith('t_bytes_')) {
variableLength = 32
} else if (variable.type.startsWith('t_bytes')) {
variableLength = variable.type.match(/uint([0-9]+)/)?.[1]
} else if (variable.type.startsWith('t_address')) {
variableLength = 20
} else {
throw new Error('unsupported type, add it to the script')
}
return {
name: variable.label,
slot: parseInt(variable.slot, 10),
offset: variable.offset,
length: variableLength,
}
}
task(
'validate-spacers',
'validates that spacer variables are in the correct positions'
).setAction(async (args, hre) => {
const accounted: string[] = []
const names = await hre.artifacts.getAllFullyQualifiedNames()
for (const name of names) {
// Script is remarkably slow because of getBuildInfo, so better to skip test files since they
// don't matter for this check.
if (name.includes('.t.sol')) {
continue
}
// Some files may not have buildInfo (certain libraries). We can safely skip these because we
// make sure that everything is accounted for anyway.
const buildInfo = await hre.artifacts.getBuildInfo(name)
if (buildInfo === undefined) {
console.log(`Skipping ${name} because it has no buildInfo`)
continue
}
for (const source of Object.values(buildInfo.output.contracts)) {
for (const [contractName, contract] of Object.entries(source)) {
const storageLayout = (contract as any).storageLayout
// Check that the layout lock is respected.
if (layoutLock[contractName]) {
const removed = Object.entries(layoutLock[contractName]).filter(
([key, val]: any) => {
const storage = storageLayout?.storage || []
return !storage.some((item: any) => {
// Skip anything that doesn't clearly match the key because otherwise we'll get an
// error while parsing the variable info for unsupported variable types.
if (!item.label.includes(key)) {
return false
}
// Make sure the variable matches **exactly**.
const variableInfo = parseVariableInfo(item)
return (
variableInfo.name === key &&
variableInfo.offset === val.offset &&
variableInfo.slot === val.slot &&
variableInfo.length === val.length
)
})
}
)
if (removed.length > 0) {
throw new Error(
`variable(s) removed from ${contractName}: ${removed.join(', ')}`
)
}
accounted.push(contractName)
}
// Check that the positions have not changed.
for (const variable of storageLayout?.storage || []) {
if (variable.label.startsWith('spacer_')) {
const [, slot, offset, length] = variable.label.split('_')
const variableInfo = parseVariableInfo(variable)
// Check that the slot is correct.
if (parseInt(slot, 10) !== variableInfo.slot) {
throw new Error(
`${contractName} ${variable.label} is in slot ${variable.slot} but should be in ${slot}`
)
}
// Check that the offset is correct.
if (parseInt(offset, 10) !== variableInfo.offset) {
throw new Error(
`${contractName} ${variable.label} is at offset ${variable.offset} but should be at ${offset}`
)
}
// Check that the length is correct.
if (parseInt(length, 10) !== variableInfo.length) {
throw new Error(
`${contractName} ${variable.label} is ${variableInfo.length} bytes long but should be ${length}`
)
}
}
}
}
}
}
for (const name of Object.keys(layoutLock)) {
if (!accounted.includes(name)) {
throw new Error(`contract ${name} is not accounted for`)
}
}
})