kc3-lang/libffi

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+libffi-ios provides an experimental port of libffi to Apple's iOS.
+
+The libffi closure mechanism has previously required the use of executable data pages, however, iOS sandbox restrictions prevent their use.
+The OS does, however, permit remapping of executable pages, allowing one to remap a single page to multiple locations. libffi-ios modifies
+ffi_closure_alloc/ffi_closure_free APIs to make use of this functionality to implement dynamically allocated and configured closure
+trampoline's without requiring the use of executable data.
+
+The implementation works by allocating a single writable config page, and then remapping a page of pre-compiled trampolines directly
+after the config page. The trampolines use PC-relative addressing to load their context from the config page, and so it is possible
+to allocate as many of these trampolines tables as you have memory space.
+
+Note that this implementation is *experimental* and has seen very limited testing.
+
+A build-ios.sh script is provided to configure and build an iOS library; you may need to edit the SDK settings in the script.