1 //! Implementation of Chalk debug helper functions using TLS.
2 use std::fmt::{self, Debug};
5 use itertools::Itertools;
8 chalk_db, db::HirDatabase, from_assoc_type_id, from_chalk_trait_id, mapping::from_chalk,
9 CallableDefId, Interner,
11 use hir_def::{AdtId, AssocContainerId, Lookup, TypeAliasId};
13 pub(crate) use unsafe_tls::{set_current_program, with_current_program};
15 pub(crate) struct DebugContext<'a>(&'a dyn HirDatabase);
17 impl DebugContext<'_> {
18 pub(crate) fn debug_struct_id(
21 f: &mut fmt::Formatter<'_>,
22 ) -> Result<(), fmt::Error> {
23 let name = match id.0 {
24 AdtId::StructId(it) => self.0.struct_data(it).name.clone(),
25 AdtId::UnionId(it) => self.0.union_data(it).name.clone(),
26 AdtId::EnumId(it) => self.0.enum_data(it).name.clone(),
31 pub(crate) fn debug_trait_id(
33 id: chalk_db::TraitId,
34 fmt: &mut fmt::Formatter<'_>,
35 ) -> Result<(), fmt::Error> {
36 let trait_: hir_def::TraitId = from_chalk_trait_id(id);
37 let trait_data = self.0.trait_data(trait_);
38 write!(fmt, "{}", trait_data.name)
41 pub(crate) fn debug_assoc_type_id(
43 id: chalk_db::AssocTypeId,
44 fmt: &mut fmt::Formatter<'_>,
45 ) -> Result<(), fmt::Error> {
46 let type_alias: TypeAliasId = from_assoc_type_id(id);
47 let type_alias_data = self.0.type_alias_data(type_alias);
48 let trait_ = match type_alias.lookup(self.0.upcast()).container {
49 AssocContainerId::TraitId(t) => t,
50 _ => panic!("associated type not in trait"),
52 let trait_data = self.0.trait_data(trait_);
53 write!(fmt, "{}::{}", trait_data.name, type_alias_data.name)
56 pub(crate) fn debug_alias(
58 alias_ty: &AliasTy<Interner>,
59 fmt: &mut fmt::Formatter<'_>,
60 ) -> Result<(), fmt::Error> {
62 AliasTy::Projection(projection_ty) => self.debug_projection_ty(projection_ty, fmt),
63 AliasTy::Opaque(opaque_ty) => opaque_ty.fmt(fmt),
67 pub(crate) fn debug_projection_ty(
69 projection_ty: &chalk_ir::ProjectionTy<Interner>,
70 fmt: &mut fmt::Formatter<'_>,
71 ) -> Result<(), fmt::Error> {
72 let type_alias = from_assoc_type_id(projection_ty.associated_ty_id);
73 let type_alias_data = self.0.type_alias_data(type_alias);
74 let trait_ = match type_alias.lookup(self.0.upcast()).container {
75 AssocContainerId::TraitId(t) => t,
76 _ => panic!("associated type not in trait"),
78 let trait_data = self.0.trait_data(trait_);
79 let params = projection_ty.substitution.as_slice(&Interner);
80 write!(fmt, "<{:?} as {}", ¶ms[0], trait_data.name,)?;
85 ¶ms[1..].iter().format_with(", ", |x, f| f(&format_args!("{:?}", x))),
88 write!(fmt, ">::{}", type_alias_data.name)
91 pub(crate) fn debug_fn_def_id(
93 fn_def_id: chalk_ir::FnDefId<Interner>,
94 fmt: &mut fmt::Formatter<'_>,
95 ) -> Result<(), fmt::Error> {
96 let def: CallableDefId = from_chalk(self.0, fn_def_id);
97 let name = match def {
98 CallableDefId::FunctionId(ff) => self.0.function_data(ff).name.clone(),
99 CallableDefId::StructId(s) => self.0.struct_data(s).name.clone(),
100 CallableDefId::EnumVariantId(e) => {
101 let enum_data = self.0.enum_data(e.parent);
102 enum_data.variants[e.local_id].name.clone()
106 CallableDefId::FunctionId(_) => write!(fmt, "{{fn {}}}", name),
107 CallableDefId::StructId(_) | CallableDefId::EnumVariantId(_) => {
108 write!(fmt, "{{ctor {}}}", name)
115 use super::DebugContext;
116 use crate::db::HirDatabase;
117 use scoped_tls::scoped_thread_local;
119 scoped_thread_local!(static PROGRAM: DebugContext);
121 pub(crate) fn with_current_program<R>(
122 op: impl for<'a> FnOnce(Option<&'a DebugContext<'a>>) -> R,
124 if PROGRAM.is_set() {
125 PROGRAM.with(|prog| op(Some(prog)))
131 pub(crate) fn set_current_program<OP, R>(p: &dyn HirDatabase, op: OP) -> R
135 let ctx = DebugContext(p);
136 // we're transmuting the lifetime in the DebugContext to static. This is
137 // fine because we only keep the reference for the lifetime of this
138 // function, *and* the only way to access the context is through
139 // `with_current_program`, which hides the lifetime through the `for`
141 let static_p: &DebugContext<'static> =
142 unsafe { std::mem::transmute::<&DebugContext, &DebugContext<'static>>(&ctx) };
143 PROGRAM.set(static_p, || op())