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| author | Matthias Krüger <matthias.krueger@famsik.de> | 2023-01-28 05:20:19 +0100 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2023-01-28 05:20:19 +0100 |
| commit | c89bb159f6d1e9049f9c42a3eb8d0f355524f029 (patch) | |
| tree | 1e9ed15684db09f0ecf9f80562834014378a4c4c /compiler/rustc_codegen_llvm/src | |
| parent | ab769a0bac7e20549caa451742331674c940eed5 (diff) | |
| parent | e5995e61687673dca684914b774d1456160f1891 (diff) | |
| download | rust-c89bb159f6d1e9049f9c42a3eb8d0f355524f029.tar.gz rust-c89bb159f6d1e9049f9c42a3eb8d0f355524f029.zip | |
Rollup merge of #107373 - michaelwoerister:dont-merge-vtables-when-debuginfo, r=WaffleLapkin
Don't merge vtables when full debuginfo is enabled. This PR makes the compiler not emit the `unnamed_addr` attribute for vtables when full debuginfo is enabled, so that they don't get merged even if they have the same contents. This allows debuggers to more reliably map from a dyn pointer to the self-type of a trait object by looking at the vtable's debuginfo. The PR only changes the behavior of the LLVM backend as other backends don't emit vtable debuginfo (as far as I can tell). The performance impact of this change should be small as [measured](https://github.com/rust-lang/rust/pull/103514#issuecomment-1290833854) in a previous PR.
Diffstat (limited to 'compiler/rustc_codegen_llvm/src')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs index b6eb5ee183f..f73bbf3d22b 100644 --- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs +++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs @@ -1499,6 +1499,11 @@ pub fn create_vtable_di_node<'ll, 'tcx>( return; } + // When full debuginfo is enabled, we want to try and prevent vtables from being + // merged. Otherwise debuggers will have a hard time mapping from dyn pointer + // to concrete type. + llvm::SetUnnamedAddress(vtable, llvm::UnnamedAddr::No); + let vtable_name = compute_debuginfo_vtable_name(cx.tcx, ty, poly_trait_ref, VTableNameKind::GlobalVariable); let vtable_type_di_node = build_vtable_type_di_node(cx, ty, poly_trait_ref); |