31 lines
1.3 KiB
Markdown
31 lines
1.3 KiB
Markdown
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### What is this
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In many cases, we have a need to create somewhat nontrivial bytecode, for testing various
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quirks related to state transition or evm execution.
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For example, we want to have a `CREATE2`- op create a contract, which is then invoked, and when invoked does a selfdestruct-to-self.
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It is overkill to go full solidity, but it is also a bit tricky do assemble this by concatenating bytes.
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This utility takes an approach from [goevmlab](https://github.com/holiman/goevmlab/) where it has been used for several years,
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a go-lang utility to assemble evm bytecode.
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Using this utility, the case above can be expressed as:
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```golang
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// Some runtime code
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runtime := program.New().Ops(vm.ADDRESS, vm.SELFDESTRUCT).Bytecode()
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// A constructor returning the runtime code
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initcode := program.New().ReturnData(runtime).Bytecode()
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// A factory invoking the constructor
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outer := program.New().Create2AndCall(initcode, nil).Bytecode()
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```
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### Warning
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This package is a utility for testing, _not_ for production. As such:
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- There are not package guarantees. We might iterate heavily on this package, and do backwards-incompatible changes without warning
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- There are no quality-guarantees. These utilities may produce evm-code that is non-functional. YMMV.
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- There are no stability-guarantees. The utility will `panic` if the inputs do not align / make sense.
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