adding new __replaceFunctionImplementation_unsafe built-in #2533
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Release notes: providing __replaceFunctionBody built-in This new built-in allows replacing the method body of functions with source code. As a result, all method calls executed by the Prepack interpreter will be redirected, and the replacement will carry over to the prepacked code.
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This seems simple enough, but I am lost trying to figure out why you need it. I'm also not quite sure it is correct. I don't have any particular reason to believe it is incorrect, but it is not OBVIOUSLY correct either. |
src/intrinsics/prepack/global.js
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| // Helper function that replaces the body of a source function with another source function body. | |||
| // Note that this function affects un-tracked state, so care must be taken | |||
| // that this helper function is executed at the right time. | |||
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What is the right time? What is the wrong time?
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That depends on what one wants. In my scenario, I'll do this replacement before the function in question will be invoked for the first time. (Ideally, I'd just replace the function object itself and be done with it without the need for __replaceFunctionBody; but unfortunately, the function is stored in a way that I can't update the reference to it.)
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| // relevant properties for functionValue |
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Is it safe in general to just update all of these properties?
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I am not entirely sure, but it's fine for my purposes...
src/intrinsics/prepack/global.js
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| // Helper function that replaces the body of a source function with another source function body. | |||
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You are not just replacing the body but the parameters too and much else beside.
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The body and everything that the body may depend on. Do you have a better name in mind?
Renaming function.
NTillmann
changed the title
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Release notes: providing __replaceFunctionImplementation_unsafe built-in
This new built-in allows replacing the method implementation (capture environment, body, ...) of source functions.
As a result, all method calls executed by the Prepack interpreter will be redirected,
and the replacement will carry over to the prepacked code.