Behavior of memory to storage copies #218
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…/Documentation into shelly/gapsfromvoodoodoc
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Going over the stale open doc PRs. @shellygr is this still relevant? If so, I'll review it |
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Should be still true |
urikirsh
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Sep 4, 2024
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urikirsh
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urikirsh
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Small fixes and a question
| put into an array in storage. | ||
| This is done by the compiler using a 'copy-loop'. | ||
| The selector component `this.testPush.selector` requires one iteration. | ||
| the string `aa` requires three iterations: according to the [ABI specification](https://docs.soliditylang.org/en/v0.8.24/abi-spec.html), |
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| the string `aa` requires three iterations: according to the [ABI specification](https://docs.soliditylang.org/en/v0.8.24/abi-spec.html), | |
| The string `aa` requires three iterations: according to the [ABI specification](https://docs.soliditylang.org/en/v0.8.24/abi-spec.html), |
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| Yes - when we copy `data` from memory to storage, the Solidity compiler | ||
| also generates code that nullifies the previous data. | ||
| As we do not know (and probably not wishing to constrain) the size of the previous data, |
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| As we do not know (and probably not wishing to constrain) the size of the previous data, | |
| As we do not know (and probably do not wish to constrain) the size of the previous data, |
| } | ||
| ``` | ||
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| The only difference in this new functionality is that we assume that the previous data has size of 225 bytes. |
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| The only difference in this new functionality is that we assume that the previous data has size of 225 bytes. | |
| The only difference in this new functionality is that we assume that the previous data has a size of 225 bytes. |
| The push to `myArray` generates the two aforementioned loops. | ||
| If we wish to analyze this code with the Prover, there are two questions to be answered: | ||
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| 1. Do we need to set a value for `--loop_iter` which is bigger than 1? |
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Isn't the prover smart enough to unroll the loop enough times for this case? The string is static
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