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Auto merge of #93154 - michaelwoerister:fix-generic-closure-and-generator-debuginfo, r=wesleywiser

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debuginfo: Make sure that type names for closure and generator environments are unique in debuginfo.

Before this change, closure/generator environments coming from different instantiations of the same generic function were all assigned the same name even though they were distinct types with potentially different data layout. Now we append the generic arguments of the originating function to the type name.

This commit also emits `{closure_env#0}` as the name of these types in order to disambiguate them from the accompanying closure function (which keeps being called `{closure#0}`). Previously both were assigned the same name.

NOTE: Changing debuginfo names like this can break pretty printers and other debugger plugins. I think it's OK in this particular case because the names we are changing were ambiguous anyway. In general though it would be great to have a process for doing changes like these.
This commit is contained in:
bors 2022-02-02 12:37:28 +00:00
commit dca1e7aa5a
14 changed files with 287 additions and 121 deletions
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110
compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs
View file

@ -13,9 +13,9 @@
use rustc_data_structures::fx::FxHashSet;
use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
use rustc_hir as hir;
use rustc_hir::def_id::DefId;
use rustc_hir::definitions::{DefPathData, DefPathDataName, DisambiguatedDefPathData};
use rustc_hir::{AsyncGeneratorKind, GeneratorKind, Mutability};
use rustc_middle::ty::layout::IntegerExt;
use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
use rustc_middle::ty::{self, AdtDef, ExistentialProjection, Ty, TyCtxt};
@ -102,14 +102,14 @@ fn push_debuginfo_type_name<'tcx>(
ty::RawPtr(ty::TypeAndMut { ty: inner_type, mutbl }) => {
if cpp_like_debuginfo {
match mutbl {
hir::Mutability::Not => output.push_str("ptr_const$<"),
hir::Mutability::Mut => output.push_str("ptr_mut$<"),
Mutability::Not => output.push_str("ptr_const$<"),
Mutability::Mut => output.push_str("ptr_mut$<"),
}
} else {
output.push('*');
match mutbl {
hir::Mutability::Not => output.push_str("const "),
hir::Mutability::Mut => output.push_str("mut "),
Mutability::Not => output.push_str("const "),
Mutability::Mut => output.push_str("mut "),
}
}
@ -131,8 +131,8 @@ fn push_debuginfo_type_name<'tcx>(
output.push_str(mutbl.prefix_str());
} else if !is_slice_or_str {
match mutbl {
hir::Mutability::Not => output.push_str("ref$<"),
hir::Mutability::Mut => output.push_str("ref_mut$<"),
Mutability::Not => output.push_str("ref$<"),
Mutability::Mut => output.push_str("ref_mut$<"),
}
}
@ -345,14 +345,39 @@ fn push_debuginfo_type_name<'tcx>(
// processing
visited.remove(t);
}
ty::Closure(def_id, ..) | ty::Generator(def_id, ..) => {
let key = tcx.def_key(def_id);
ty::Closure(def_id, substs) | ty::Generator(def_id, substs, ..) => {
// Name will be "{closure_env#0}<T1, T2, ...>", "{generator_env#0}<T1, T2, ...>", or
// "{async_fn_env#0}<T1, T2, ...>", etc.
let def_key = tcx.def_key(def_id);
if qualified {
let parent_def_id = DefId { index: key.parent.unwrap(), ..def_id };
let parent_def_id = DefId { index: def_key.parent.unwrap(), ..def_id };
push_item_name(tcx, parent_def_id, true, output);
output.push_str("::");
}
push_unqualified_item_name(tcx, def_id, key.disambiguated_data, output);
let mut label = String::with_capacity(20);
write!(&mut label, "{}_env", generator_kind_label(tcx.generator_kind(def_id))).unwrap();
push_disambiguated_special_name(
&label,
def_key.disambiguated_data.disambiguator,
cpp_like_debuginfo,
output,
);
// We also need to add the generic arguments of the async fn/generator or
// the enclosing function (for closures or async blocks), so that we end
// up with a unique name for every instantiation.
// Find the generics of the enclosing function, as defined in the source code.
let enclosing_fn_def_id = tcx.typeck_root_def_id(def_id);
let generics = tcx.generics_of(enclosing_fn_def_id);
// Truncate the substs to the length of the above generics. This will cut off
// anything closure- or generator-specific.
let substs = substs.truncate_to(tcx, generics);
push_generic_params_internal(tcx, substs, output, visited);
}
// Type parameters from polymorphized functions.
ty::Param(_) => {
@ -509,6 +534,29 @@ pub fn push_item_name(tcx: TyCtxt<'_>, def_id: DefId, qualified: bool, output: &
push_unqualified_item_name(tcx, def_id, def_key.disambiguated_data, output);
}
fn generator_kind_label(generator_kind: Option<GeneratorKind>) -> &'static str {
match generator_kind {
Some(GeneratorKind::Async(AsyncGeneratorKind::Block)) => "async_block",
Some(GeneratorKind::Async(AsyncGeneratorKind::Closure)) => "async_closure",
Some(GeneratorKind::Async(AsyncGeneratorKind::Fn)) => "async_fn",
Some(GeneratorKind::Gen) => "generator",
None => "closure",
}
}
fn push_disambiguated_special_name(
label: &str,
disambiguator: u32,
cpp_like_debuginfo: bool,
output: &mut String,
) {
if cpp_like_debuginfo {
write!(output, "{}${}", label, disambiguator).unwrap();
} else {
write!(output, "{{{}#{}}}", label, disambiguator).unwrap();
}
}
fn push_unqualified_item_name(
tcx: TyCtxt<'_>,
def_id: DefId,
@ -519,42 +567,32 @@ fn push_unqualified_item_name(
DefPathData::CrateRoot => {
output.push_str(tcx.crate_name(def_id.krate).as_str());
}
DefPathData::ClosureExpr if tcx.generator_kind(def_id).is_some() => {
let key = match tcx.generator_kind(def_id).unwrap() {
hir::GeneratorKind::Async(hir::AsyncGeneratorKind::Block) => "async_block",
hir::GeneratorKind::Async(hir::AsyncGeneratorKind::Closure) => "async_closure",
hir::GeneratorKind::Async(hir::AsyncGeneratorKind::Fn) => "async_fn",
hir::GeneratorKind::Gen => "generator",
};
// Generators look like closures, but we want to treat them differently
// in the debug info.
if cpp_like_debuginfo(tcx) {
write!(output, "{}${}", key, disambiguated_data.disambiguator).unwrap();
} else {
write!(output, "{{{}#{}}}", key, disambiguated_data.disambiguator).unwrap();
}
DefPathData::ClosureExpr => {
let label = generator_kind_label(tcx.generator_kind(def_id));
push_disambiguated_special_name(
label,
disambiguated_data.disambiguator,
cpp_like_debuginfo(tcx),
output,
);
}
_ => match disambiguated_data.data.name() {
DefPathDataName::Named(name) => {
output.push_str(name.as_str());
}
DefPathDataName::Anon { namespace } => {
if cpp_like_debuginfo(tcx) {
write!(output, "{}${}", namespace, disambiguated_data.disambiguator).unwrap();
} else {
write!(output, "{{{}#{}}}", namespace, disambiguated_data.disambiguator)
.unwrap();
}
push_disambiguated_special_name(
namespace.as_str(),
disambiguated_data.disambiguator,
cpp_like_debuginfo(tcx),
output,
);
}
},
};
}
// Pushes the generic parameters in the given `InternalSubsts` to the output string.
// This ignores region parameters, since they can't reliably be
// reconstructed for items from non-local crates. For local crates, this
// would be possible but with inlining and LTO we have to use the least
// common denominator - otherwise we would run into conflicts.
fn push_generic_params_internal<'tcx>(
tcx: TyCtxt<'tcx>,
substs: SubstsRef<'tcx>,