Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Don't merge vtables when full debuginfo is enabled. #107373

Merged
merged 1 commit into from
Jan 28, 2023
Merged

Don't merge vtables when full debuginfo is enabled. #107373

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 5 additions & 0 deletions compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down
8 changes: 8 additions & 0 deletions tests/codegen/debug-vtable.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,14 @@
// compile-flags: -Cdebuginfo=2 -Copt-level=0 -Csymbol-mangling-version=v0
// ignore-tidy-linelength

// Make sure that vtables don't have the unnamed_addr attribute when debuginfo is enabled.
// This helps debuggers more reliably map from dyn pointer to concrete type.
// CHECK: @vtable.0 = private constant <{
// CHECK: @vtable.1 = private constant <{
// CHECK: @vtable.2 = private constant <{
// CHECK: @vtable.3 = private constant <{
// CHECK: @vtable.4 = private constant <{

// NONMSVC: ![[USIZE:[0-9]+]] = !DIBasicType(name: "usize"
// MSVC: ![[USIZE:[0-9]+]] = !DIDerivedType(tag: DW_TAG_typedef, name: "usize"
// NONMSVC: ![[PTR:[0-9]+]] = !DIDerivedType(tag: DW_TAG_pointer_type, name: "*const ()"
Expand Down