66 lines
2.4 KiB
Rust
66 lines
2.4 KiB
Rust
//! Unwinding for *emscripten* target.
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//!
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//! Whereas Rust's usual unwinding implementation for Unix platforms
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//! calls into the libunwind APIs directly, on Emscripten we instead
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//! call into the C++ unwinding APIs. This is just an expedience since
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//! Emscripten's runtime always implements those APIs and does not
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//! implement libunwind.
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#![allow(private_no_mangle_fns)]
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use core::any::Any;
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use core::ptr;
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use core::mem;
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use alloc::boxed::Box;
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use libc::{self, c_int};
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use unwind as uw;
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pub fn payload() -> *mut u8 {
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ptr::null_mut()
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}
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pub unsafe fn cleanup(ptr: *mut u8) -> Box<dyn Any + Send> {
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assert!(!ptr.is_null());
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let ex = ptr::read(ptr as *mut _);
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__cxa_free_exception(ptr as *mut _);
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ex
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}
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pub unsafe fn panic(data: Box<dyn Any + Send>) -> u32 {
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let sz = mem::size_of_val(&data);
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let exception = __cxa_allocate_exception(sz);
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if exception == ptr::null_mut() {
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return uw::_URC_FATAL_PHASE1_ERROR as u32;
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}
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let exception = exception as *mut Box<dyn Any + Send>;
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ptr::write(exception, data);
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__cxa_throw(exception as *mut _, ptr::null_mut(), ptr::null_mut());
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unreachable!()
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}
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#[lang = "eh_personality"]
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#[no_mangle]
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unsafe extern "C" fn rust_eh_personality(version: c_int,
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actions: uw::_Unwind_Action,
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exception_class: uw::_Unwind_Exception_Class,
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exception_object: *mut uw::_Unwind_Exception,
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context: *mut uw::_Unwind_Context)
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-> uw::_Unwind_Reason_Code {
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__gxx_personality_v0(version, actions, exception_class, exception_object, context)
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}
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extern "C" {
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fn __cxa_allocate_exception(thrown_size: libc::size_t) -> *mut libc::c_void;
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fn __cxa_free_exception(thrown_exception: *mut libc::c_void);
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fn __cxa_throw(thrown_exception: *mut libc::c_void,
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tinfo: *mut libc::c_void,
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dest: *mut libc::c_void);
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fn __gxx_personality_v0(version: c_int,
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actions: uw::_Unwind_Action,
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exception_class: uw::_Unwind_Exception_Class,
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exception_object: *mut uw::_Unwind_Exception,
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context: *mut uw::_Unwind_Context)
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-> uw::_Unwind_Reason_Code;
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}
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