From 8bda13367e4987937ddc2ba9bbe01b5f7a4cce3e Mon Sep 17 00:00:00 2001 From: Gary Guo Date: Wed, 5 Oct 2022 02:29:56 +0100 Subject: [PATCH] Interpret EH actions properly The EH actions stored in the LSDA follows the format of GCC except table (even for LLVM-generated code). An missing action in the table is the encoding for `Terminate`, see [1]. The currently code interprets it as `None`, as a workaround for #35011, an issue that seems to occur in LLVM 3.7 and not after 3.9. These are very old versions of LLVM and we don't support them anymore, so remove this workaround and interpret them properly. Note that LLVM currently does not emit any `Terminate` actions, but GCC does. Although GCC backend currently doesn't do unwinding, removing it preemptively would prevent future developers from wasting time to figure out what's wrong. [1]: https://github.com/gcc-mirror/gcc/blob/master/libstdc%2B%2B-v3/libsupc%2B%2B/eh_personality.cc#L522-L526 --- library/std/src/personality/dwarf/eh.rs | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/library/std/src/personality/dwarf/eh.rs b/library/std/src/personality/dwarf/eh.rs index 8799137b78f98..27b50c13b77ca 100644 --- a/library/std/src/personality/dwarf/eh.rs +++ b/library/std/src/personality/dwarf/eh.rs @@ -98,9 +98,8 @@ pub unsafe fn find_eh_action(lsda: *const u8, context: &EHContext<'_>) -> Result } } } - // Ip is not present in the table. This should not happen... but it does: issue #35011. - // So rather than returning EHAction::Terminate, we do this. - Ok(EHAction::None) + // Ip is not present in the table. This indicates a nounwind call. + Ok(EHAction::Terminate) } else { // SjLj version: // The "IP" is an index into the call-site table, with two exceptions: