bjoernager/rust
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Create more accurate debuginfo for vtables.

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Before this commit all vtables would have the same name "vtable" in
debuginfo. Now they get a name that identifies the implementing type
and the trait that is being implemented.
This commit is contained in:
Michael Woerister 2021-10-06 14:26:50 +02:00
parent a4797664ba
commit 61c5a6d644
8 changed files with 163 additions and 62 deletions
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56
compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs
View file

@ -446,6 +446,62 @@ fn push_debuginfo_type_name<'tcx>(
}
}
/// Computes a name for the global variable storing a vtable.
///
/// The name is of the form:
///
/// `<path::to::SomeType as path::to::SomeTrait>::{vtable}`
///
/// or, when generating C++-like names:
///
/// `impl$<path::to::SomeType, path::to::SomeTrait>::vtable$`
pub fn compute_debuginfo_vtable_name<'tcx>(
tcx: TyCtxt<'tcx>,
t: Ty<'tcx>,
trait_ref: Option<ty::PolyExistentialTraitRef<'tcx>>,
) -> String {
let cpp_like_names = cpp_like_names(tcx);
let mut vtable_name = String::with_capacity(64);
if cpp_like_names {
vtable_name.push_str("impl$<");
} else {
vtable_name.push('<');
}
let mut visited = FxHashSet::default();
push_debuginfo_type_name(tcx, t, true, &mut vtable_name, &mut visited);
if cpp_like_names {
vtable_name.push_str(", ");
} else {
vtable_name.push_str(" as ");
}
if let Some(trait_ref) = trait_ref {
push_item_name(tcx, trait_ref.skip_binder().def_id, true, &mut vtable_name);
visited.clear();
push_generic_params_internal(
tcx,
trait_ref.skip_binder().substs,
&mut vtable_name,
&mut visited,
);
} else {
vtable_name.push_str("_");
}
push_close_angle_bracket(cpp_like_names, &mut vtable_name);
let suffix = if cpp_like_names { "::vtable$" } else { "::{vtable}" };
vtable_name.reserve_exact(suffix.len());
vtable_name.push_str(suffix);
vtable_name
}
pub fn push_item_name(tcx: TyCtxt<'tcx>, def_id: DefId, qualified: bool, output: &mut String) {
let def_key = tcx.def_key(def_id);
if qualified {