Two-level namespace #34
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I've cleaned this up, hopefully this can get a reviewer or two. @grp do you have any thoughts on this, either in general or on the code? |
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I don't know much about the implementation of two-level namespacing. :( It looked cool reading through it, though. |
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I'll review this in a ~week, hopefully that will give me somewhat fresh eyes to catch bugs, issues, readability problems, etc. I'd like to write a few more tests too (though I probably won't check the tests in). |
Allow backward compatibility symbol search (all dylibs) by specifying a NULL dylib in the `rebinding`.
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This change adds support for rebinding that leverages mach-o's two-level namespace.
The tl;dr of two-level namespaces is that symbols imported from other libraries will reference which library they came from. When rebinding a symbol by name alone, it's possible to unintentionally rebind symbols that happen to have the same name, which can cause unexpected results. Using the two-level namespace prevents the mysterious bugs and crashes that can happen when rebinding by just symbol name alone.
In addition to correctness, this change opens a new performance optimization, see 7cc0515.
This change is a breaking change: callers of
rebind_symbolsnow need to fill in adylibfield on therebindingstruct. This field can beNULLto opt-out of two-level namespaces, and enable the previous global search.Resolves #32