Add debuginfo_transparent attribute for structs #144223
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rustbot has assigned @petrochenkov. Use |
rustbot
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A-attributes
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Some changes occurred in compiler/rustc_passes/src/check_attr.rs Some changes occurred in compiler/rustc_attr_data_structures Some changes occurred in compiler/rustc_attr_parsing |
| @@ -1070,6 +1071,16 @@ fn build_struct_type_di_node<'ll, 'tcx>( | |||
| None | |||
| }; | |||
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| if find_attr!(cx.tcx.get_all_attrs(adt_def.did()), AttributeKind::DebuginfoTransparent(..)) { | |||
| let ty = struct_type_and_layout.non_1zst_field(cx).unwrap().1.ty; | |||
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Is there a way to ensure that #[debuginfo_transparent] can only be used when #[repr(transparent)] is also used? And how should I handle the case where all fields are 1zst's?
| @@ -7,7 +7,7 @@ | |||
| // gdb-command:run | |||
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| // gdb-command:print plain_string | |||
| // gdb-check:$1 = alloc::string::String {vec: alloc::vec::Vec<u8, alloc::alloc::Global> {buf: alloc::raw_vec::RawVec<u8, alloc::alloc::Global> {inner: alloc::raw_vec::RawVecInner<alloc::alloc::Global> {ptr: core::ptr::unique::Unique<u8> {pointer: core::ptr::non_null::NonNull<u8> {pointer: 0x[...]}, _marker: core::marker::PhantomData<u8>}, cap: core::num::niche_types::UsizeNoHighBit (5), alloc: alloc::alloc::Global}, _marker: core::marker::PhantomData<u8>}, len: 5}} | |||
| // gdb-check:$1 = alloc::string::String {vec: alloc::vec::Vec<u8, alloc::alloc::Global> {buf: alloc::raw_vec::RawVec<u8, alloc::alloc::Global> {inner: alloc::raw_vec::RawVecInner<alloc::alloc::Global> {ptr: 0x[...], cap: 5, alloc: alloc::alloc::Global}, _marker: core::marker::PhantomData<u8>}, len: 5}} | |||
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This is the improvement this PR causes. Further improvements could be made using future #[debuginfo_flatten] and #[debuginfo_hidden] attributes on RawVec/RawVecInner and the _marker field, which would result in
alloc::string::String {vec: alloc::vec::Vec<u8, alloc::alloc::Global> {ptr: 0x[...], cap: 5, alloc: alloc::alloc::Global, len: 5}}
src/etc/gdb_providers.py
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Similar changes would need to be made for LLDB, but LLDB is broken on the dev-desktop.
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bjorn3
added
the
A-debuginfo
This attribute causes the struct to be unwrapped at the debuginfo level the same way that repr(transparent) unwraps it at the ABI level. This is useful for preventing types like NonNull and Unique from making the debuginfo harder to read when pretty printers aren't used.
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There are changes to the cc @jieyouxu |
rustbot
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A-tidy
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The job Click to see the possible cause of the failure (guessed by this bot) |
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I don't have a strong opinion on whether this attribute should be added or not. I'll delegate this to the lang team, because it approves new attributes anyway. Also, for the implementation maybe find some other reviewer more interested in debuginfo? |
petrochenkov
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S-waiting-on-team
This attribute causes the struct to be unwrapped at the debuginfo level the same way that repr(transparent) unwraps it at the ABI level. This is useful for preventing types like NonNull and Unique from making the debuginfo harder to read when pretty printers aren't used.