bjoernager/rust
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Add UnwindAction::Unreachable

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This also makes eval machine's `StackPopUnwind`
redundant so that is replaced.
This commit is contained in:
Gary Guo 2022-10-10 19:50:49 +01:00
parent daeb844e0c
commit 5e6ed132fa
23 changed files with 160 additions and 149 deletions
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55
compiler/rustc_codegen_ssa/src/mir/block.rs
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@ -156,7 +156,7 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
fn_ptr: Bx::Value,
llargs: &[Bx::Value],
destination: Option<(ReturnDest<'tcx, Bx::Value>, mir::BasicBlock)>,
unwind: mir::UnwindAction,
mut unwind: mir::UnwindAction,
copied_constant_arguments: &[PlaceRef<'tcx, <Bx as BackendTypes>::Value>],
mergeable_succ: bool,
) -> MergingSucc {
@ -164,27 +164,28 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
// do an invoke, otherwise do a call.
let fn_ty = bx.fn_decl_backend_type(&fn_abi);
let cleanup = match unwind {
mir::UnwindAction::Cleanup(cleanup) => Some(cleanup),
if !fn_abi.can_unwind {
unwind = mir::UnwindAction::Unreachable;
}
let unwind_block = match unwind {
mir::UnwindAction::Cleanup(cleanup) => Some(self.llbb_with_cleanup(fx, cleanup)),
_ if fx.mir[self.bb].is_cleanup
&& fn_abi.can_unwind
&& !base::wants_msvc_seh(fx.cx.tcx().sess) =>
{
// Exception must not propagate out of the execution of a cleanup (doing so
// can cause undefined behaviour). We insert a double unwind guard for
// functions that can potentially unwind to protect against this.
//
// This is not necessary for SEH which does not use successive unwinding
// like Itanium EH. EH frames in SEH are different from normal function
// frames and SEH will abort automatically if an exception tries to
// propagate out from cleanup.
Some(fx.double_unwind_guard())
}
mir::UnwindAction::Continue => None,
};
let unwind_block = if let Some(cleanup) = cleanup.filter(|_| fn_abi.can_unwind) {
Some(self.llbb_with_cleanup(fx, cleanup))
} else if fx.mir[self.bb].is_cleanup
&& fn_abi.can_unwind
&& !base::wants_msvc_seh(fx.cx.tcx().sess)
{
// Exception must not propagate out of the execution of a cleanup (doing so
// can cause undefined behaviour). We insert a double unwind guard for
// functions that can potentially unwind to protect against this.
//
// This is not necessary for SEH which does not use successive unwinding
// like Itanium EH. EH frames in SEH are different from normal function
// frames and SEH will abort automatically if an exception tries to
// propagate out from cleanup.
Some(fx.double_unwind_guard())
} else {
None
mir::UnwindAction::Unreachable => None,
};
if let Some(unwind_block) = unwind_block {
@ -640,7 +641,17 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
let (fn_abi, llfn) = common::build_langcall(bx, Some(span), LangItem::PanicCannotUnwind);
// Codegen the actual panic invoke/call.
let merging_succ = helper.do_call(self, bx, fn_abi, llfn, &[], None, mir::UnwindAction::Continue, &[], false);
let merging_succ = helper.do_call(
self,
bx,
fn_abi,
llfn,
&[],
None,
mir::UnwindAction::Unreachable,
&[],
false,
);
assert_eq!(merging_succ, MergingSucc::False);
}