rustc_mir_build/thir/cx/
mod.rs1use rustc_data_structures::steal::Steal;
6use rustc_errors::ErrorGuaranteed;
7use rustc_hir as hir;
8use rustc_hir::HirId;
9use rustc_hir::def::DefKind;
10use rustc_hir::def_id::{DefId, LocalDefId};
11use rustc_hir::lang_items::LangItem;
12use rustc_middle::bug;
13use rustc_middle::middle::region;
14use rustc_middle::thir::*;
15use rustc_middle::ty::{self, RvalueScopes, TyCtxt};
16use tracing::instrument;
17
18use crate::thir::pattern::pat_from_hir;
19
20pub(crate) fn thir_body(
22 tcx: TyCtxt<'_>,
23 owner_def: LocalDefId,
24) -> Result<(&Steal<Thir<'_>>, ExprId), ErrorGuaranteed> {
25 let body = tcx.hir_body_owned_by(owner_def);
26 let mut cx = ThirBuildCx::new(tcx, owner_def);
27 if let Some(reported) = cx.typeck_results.tainted_by_errors {
28 return Err(reported);
29 }
30
31 let owner_id = tcx.local_def_id_to_hir_id(owner_def);
33 if let Some(fn_decl) = tcx.hir_fn_decl_by_hir_id(owner_id) {
34 let closure_env_param = cx.closure_env_param(owner_def, owner_id);
35 let explicit_params = cx.explicit_params(owner_id, fn_decl, &body);
36 cx.thir.params = closure_env_param.into_iter().chain(explicit_params).collect();
37
38 if tcx.is_coroutine(owner_def.to_def_id()) && body.params.is_empty() {
41 cx.thir.params.push(Param {
42 ty: tcx.types.unit,
43 pat: None,
44 ty_span: None,
45 self_kind: None,
46 hir_id: None,
47 });
48 }
49 }
50
51 let expr = cx.mirror_expr(body.value);
52 Ok((tcx.alloc_steal_thir(cx.thir), expr))
53}
54
55struct ThirBuildCx<'tcx> {
57 tcx: TyCtxt<'tcx>,
58 thir: Thir<'tcx>,
60
61 typing_env: ty::TypingEnv<'tcx>,
62
63 region_scope_tree: &'tcx region::ScopeTree,
64 typeck_results: &'tcx ty::TypeckResults<'tcx>,
65 rvalue_scopes: &'tcx RvalueScopes,
66
67 apply_adjustments: bool,
69
70 body_owner: DefId,
72}
73
74impl<'tcx> ThirBuildCx<'tcx> {
75 fn new(tcx: TyCtxt<'tcx>, def: LocalDefId) -> Self {
76 let typeck_results = tcx.typeck(def);
77 let hir_id = tcx.local_def_id_to_hir_id(def);
78
79 let body_type = match tcx.hir_body_owner_kind(def) {
80 rustc_hir::BodyOwnerKind::Fn | rustc_hir::BodyOwnerKind::Closure => {
81 BodyTy::Fn(typeck_results.liberated_fn_sigs()[hir_id])
84 }
85 rustc_hir::BodyOwnerKind::Const { .. } | rustc_hir::BodyOwnerKind::Static(_) => {
86 BodyTy::Const(typeck_results.node_type(hir_id))
98 }
99 rustc_hir::BodyOwnerKind::GlobalAsm => {
100 BodyTy::GlobalAsm(typeck_results.node_type(hir_id))
101 }
102 };
103
104 Self {
105 tcx,
106 thir: Thir::new(body_type),
107 typing_env: ty::TypingEnv::non_body_analysis(tcx, def),
110 region_scope_tree: tcx.region_scope_tree(def),
111 typeck_results,
112 rvalue_scopes: &typeck_results.rvalue_scopes,
113 body_owner: def.to_def_id(),
114 apply_adjustments: tcx
115 .hir_attrs(hir_id)
116 .iter()
117 .all(|attr| !attr.has_name(rustc_span::sym::custom_mir)),
118 }
119 }
120
121 #[instrument(level = "debug", skip(self))]
122 fn pattern_from_hir(&mut self, p: &'tcx hir::Pat<'tcx>) -> Box<Pat<'tcx>> {
123 pat_from_hir(self.tcx, self.typing_env, self.typeck_results, p)
124 }
125
126 fn closure_env_param(&self, owner_def: LocalDefId, expr_id: HirId) -> Option<Param<'tcx>> {
127 if self.tcx.def_kind(owner_def) != DefKind::Closure {
128 return None;
129 }
130
131 let closure_ty = self.typeck_results.node_type(expr_id);
132 Some(match *closure_ty.kind() {
133 ty::Coroutine(..) => {
134 Param { ty: closure_ty, pat: None, ty_span: None, self_kind: None, hir_id: None }
135 }
136 ty::Closure(_, args) => {
137 let closure_env_ty = self.tcx.closure_env_ty(
138 closure_ty,
139 args.as_closure().kind(),
140 self.tcx.lifetimes.re_erased,
141 );
142 Param {
143 ty: closure_env_ty,
144 pat: None,
145 ty_span: None,
146 self_kind: None,
147 hir_id: None,
148 }
149 }
150 ty::CoroutineClosure(_, args) => {
151 let closure_env_ty = self.tcx.closure_env_ty(
152 closure_ty,
153 args.as_coroutine_closure().kind(),
154 self.tcx.lifetimes.re_erased,
155 );
156 Param {
157 ty: closure_env_ty,
158 pat: None,
159 ty_span: None,
160 self_kind: None,
161 hir_id: None,
162 }
163 }
164 _ => bug!("unexpected closure type: {closure_ty}"),
165 })
166 }
167
168 fn explicit_params(
169 &mut self,
170 owner_id: HirId,
171 fn_decl: &'tcx hir::FnDecl<'tcx>,
172 body: &'tcx hir::Body<'tcx>,
173 ) -> impl Iterator<Item = Param<'tcx>> {
174 let fn_sig = self.typeck_results.liberated_fn_sigs()[owner_id];
175
176 body.params.iter().enumerate().map(move |(index, param)| {
177 let ty_span = fn_decl
178 .inputs
179 .get(index)
180 .and_then(|ty| if param.pat.span != ty.span { Some(ty.span) } else { None });
182
183 let self_kind = if index == 0 && fn_decl.implicit_self.has_implicit_self() {
184 Some(fn_decl.implicit_self)
185 } else {
186 None
187 };
188
189 let ty = if fn_decl.c_variadic && index == fn_decl.inputs.len() {
192 let va_list_did = self.tcx.require_lang_item(LangItem::VaList, Some(param.span));
193
194 self.tcx
195 .type_of(va_list_did)
196 .instantiate(self.tcx, &[self.tcx.lifetimes.re_erased.into()])
197 } else {
198 fn_sig.inputs()[index]
199 };
200
201 let pat = self.pattern_from_hir(param.pat);
202 Param { pat: Some(pat), ty, ty_span, self_kind, hir_id: Some(param.hir_id) }
203 })
204 }
205
206 fn user_args_applied_to_ty_of_hir_id(
207 &self,
208 hir_id: HirId,
209 ) -> Option<ty::CanonicalUserType<'tcx>> {
210 crate::thir::util::user_args_applied_to_ty_of_hir_id(self.tcx, self.typeck_results, hir_id)
211 }
212}
213
214mod block;
215mod expr;