bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir-ty/src/infer/expr.rs')
-rw-r--r--crates/hir-ty/src/infer/expr.rs187
1 files changed, 104 insertions, 83 deletions
diff --git a/crates/hir-ty/src/infer/expr.rs b/crates/hir-ty/src/infer/expr.rs
index 2a13106390..2d04a864a2 100644
--- a/crates/hir-ty/src/infer/expr.rs
+++ b/crates/hir-ty/src/infer/expr.rs
@@ -10,7 +10,7 @@ use chalk_ir::{
cast::Cast, fold::Shift, DebruijnIndex, GenericArgData, Mutability, TyVariableKind,
};
use hir_def::{
- expr::{ArithOp, Array, BinaryOp, CmpOp, Expr, ExprId, Literal, Statement, UnaryOp},
+ expr::{ArithOp, Array, BinaryOp, CmpOp, Expr, ExprId, LabelId, Literal, Statement, UnaryOp},
generics::TypeOrConstParamData,
path::{GenericArg, GenericArgs},
resolver::resolver_for_expr,
@@ -23,7 +23,7 @@ use syntax::ast::RangeOp;
use crate::{
autoderef::{self, Autoderef},
consteval,
- infer::coerce::CoerceMany,
+ infer::{coerce::CoerceMany, find_continuable, BreakableKind},
lower::{
const_or_path_to_chalk, generic_arg_to_chalk, lower_to_chalk_mutability, ParamLoweringMode,
},
@@ -120,32 +120,37 @@ impl<'a> InferenceContext<'a> {
let ty = match label {
Some(_) => {
let break_ty = self.table.new_type_var();
- self.breakables.push(BreakableContext {
- may_break: false,
- coerce: CoerceMany::new(break_ty.clone()),
- label: label.map(|label| self.body[label].name.clone()),
- });
- let ty = self.infer_block(
- tgt_expr,
- statements,
- *tail,
- &Expectation::has_type(break_ty),
+ let (breaks, ty) = self.with_breakable_ctx(
+ BreakableKind::Block,
+ break_ty.clone(),
+ *label,
+ |this| {
+ this.infer_block(
+ tgt_expr,
+ statements,
+ *tail,
+ &Expectation::has_type(break_ty),
+ )
+ },
);
- let ctxt = self.breakables.pop().expect("breakable stack broken");
- if ctxt.may_break {
- ctxt.coerce.complete()
- } else {
- ty
- }
+ breaks.unwrap_or(ty)
}
None => self.infer_block(tgt_expr, statements, *tail, expected),
};
self.resolver = old_resolver;
ty
}
- Expr::Unsafe { body } | Expr::Const { body } => self.infer_expr(*body, expected),
+ Expr::Unsafe { body } => self.infer_expr(*body, expected),
+ Expr::Const { body } => {
+ self.with_breakable_ctx(BreakableKind::Border, self.err_ty(), None, |this| {
+ this.infer_expr(*body, expected)
+ })
+ .1
+ }
Expr::TryBlock { body } => {
- let _inner = self.infer_expr(*body, expected);
+ self.with_breakable_ctx(BreakableKind::Border, self.err_ty(), None, |this| {
+ let _inner = this.infer_expr(*body, expected);
+ });
// FIXME should be std::result::Result<{inner}, _>
self.err_ty()
}
@@ -154,7 +159,10 @@ impl<'a> InferenceContext<'a> {
let prev_diverges = mem::replace(&mut self.diverges, Diverges::Maybe);
let prev_ret_ty = mem::replace(&mut self.return_ty, ret_ty.clone());
- let inner_ty = self.infer_expr_coerce(*body, &Expectation::has_type(ret_ty));
+ let (_, inner_ty) =
+ self.with_breakable_ctx(BreakableKind::Border, self.err_ty(), None, |this| {
+ this.infer_expr_coerce(*body, &Expectation::has_type(ret_ty))
+ });
self.diverges = prev_diverges;
self.return_ty = prev_ret_ty;
@@ -166,54 +174,44 @@ impl<'a> InferenceContext<'a> {
TyKind::OpaqueType(opaque_ty_id, Substitution::from1(Interner, inner_ty))
.intern(Interner)
}
- Expr::Loop { body, label } => {
- self.breakables.push(BreakableContext {
- may_break: false,
- coerce: CoerceMany::new(self.table.new_type_var()),
- label: label.map(|label| self.body[label].name.clone()),
- });
- self.infer_expr(*body, &Expectation::has_type(TyBuilder::unit()));
-
- let ctxt = self.breakables.pop().expect("breakable stack broken");
+ &Expr::Loop { body, label } => {
+ let ty = self.table.new_type_var();
+ let (breaks, ()) =
+ self.with_breakable_ctx(BreakableKind::Loop, ty, label, |this| {
+ this.infer_expr(body, &Expectation::has_type(TyBuilder::unit()));
+ });
- if ctxt.may_break {
- self.diverges = Diverges::Maybe;
- ctxt.coerce.complete()
- } else {
- TyKind::Never.intern(Interner)
+ match breaks {
+ Some(breaks) => {
+ self.diverges = Diverges::Maybe;
+ breaks
+ }
+ None => TyKind::Never.intern(Interner),
}
}
- Expr::While { condition, body, label } => {
- self.breakables.push(BreakableContext {
- may_break: false,
- coerce: CoerceMany::new(self.err_ty()),
- label: label.map(|label| self.body[label].name.clone()),
+ &Expr::While { condition, body, label } => {
+ self.with_breakable_ctx(BreakableKind::Loop, self.err_ty(), label, |this| {
+ this.infer_expr(
+ condition,
+ &Expectation::has_type(TyKind::Scalar(Scalar::Bool).intern(Interner)),
+ );
+ this.infer_expr(body, &Expectation::has_type(TyBuilder::unit()));
});
- self.infer_expr(
- *condition,
- &Expectation::has_type(TyKind::Scalar(Scalar::Bool).intern(Interner)),
- );
- self.infer_expr(*body, &Expectation::has_type(TyBuilder::unit()));
- let _ctxt = self.breakables.pop().expect("breakable stack broken");
+
// the body may not run, so it diverging doesn't mean we diverge
self.diverges = Diverges::Maybe;
TyBuilder::unit()
}
- Expr::For { iterable, body, pat, label } => {
- let iterable_ty = self.infer_expr(*iterable, &Expectation::none());
-
- self.breakables.push(BreakableContext {
- may_break: false,
- coerce: CoerceMany::new(self.err_ty()),
- label: label.map(|label| self.body[label].name.clone()),
- });
+ &Expr::For { iterable, body, pat, label } => {
+ let iterable_ty = self.infer_expr(iterable, &Expectation::none());
let pat_ty =
self.resolve_associated_type(iterable_ty, self.resolve_into_iter_item());
- self.infer_pat(*pat, &pat_ty, BindingMode::default());
+ self.infer_pat(pat, &pat_ty, BindingMode::default());
+ self.with_breakable_ctx(BreakableKind::Loop, self.err_ty(), label, |this| {
+ this.infer_expr(body, &Expectation::has_type(TyBuilder::unit()));
+ });
- self.infer_expr(*body, &Expectation::has_type(TyBuilder::unit()));
- let _ctxt = self.breakables.pop().expect("breakable stack broken");
// the body may not run, so it diverging doesn't mean we diverge
self.diverges = Diverges::Maybe;
TyBuilder::unit()
@@ -269,7 +267,9 @@ impl<'a> InferenceContext<'a> {
let prev_diverges = mem::replace(&mut self.diverges, Diverges::Maybe);
let prev_ret_ty = mem::replace(&mut self.return_ty, ret_ty.clone());
- self.infer_expr_coerce(*body, &Expectation::has_type(ret_ty));
+ self.with_breakable_ctx(BreakableKind::Border, self.err_ty(), None, |this| {
+ this.infer_expr_coerce(*body, &Expectation::has_type(ret_ty));
+ });
self.diverges = prev_diverges;
self.return_ty = prev_ret_ty;
@@ -372,37 +372,45 @@ impl<'a> InferenceContext<'a> {
let resolver = resolver_for_expr(self.db.upcast(), self.owner, tgt_expr);
self.infer_path(&resolver, p, tgt_expr.into()).unwrap_or_else(|| self.err_ty())
}
- Expr::Continue { .. } => TyKind::Never.intern(Interner),
- Expr::Break { expr, label } => {
- let mut coerce = match find_breakable(&mut self.breakables, label.as_ref()) {
- Some(ctxt) => {
- // avoiding the borrowck
- mem::replace(
- &mut ctxt.coerce,
- CoerceMany::new(self.result.standard_types.unknown.clone()),
- )
- }
- None => CoerceMany::new(self.result.standard_types.unknown.clone()),
+ Expr::Continue { label } => {
+ if let None = find_continuable(&mut self.breakables, label.as_ref()) {
+ self.push_diagnostic(InferenceDiagnostic::BreakOutsideOfLoop {
+ expr: tgt_expr,
+ is_break: false,
+ });
};
-
+ TyKind::Never.intern(Interner)
+ }
+ Expr::Break { expr, label } => {
let val_ty = if let Some(expr) = *expr {
self.infer_expr(expr, &Expectation::none())
} else {
TyBuilder::unit()
};
- // FIXME: create a synthetic `()` during lowering so we have something to refer to here?
- coerce.coerce(self, *expr, &val_ty);
+ match find_breakable(&mut self.breakables, label.as_ref()) {
+ Some(ctxt) => {
+ // avoiding the borrowck
+ let mut coerce = mem::replace(
+ &mut ctxt.coerce,
+ CoerceMany::new(self.result.standard_types.unknown.clone()),
+ );
- if let Some(ctxt) = find_breakable(&mut self.breakables, label.as_ref()) {
- ctxt.coerce = coerce;
- ctxt.may_break = true;
- } else {
- self.push_diagnostic(InferenceDiagnostic::BreakOutsideOfLoop {
- expr: tgt_expr,
- });
- };
+ // FIXME: create a synthetic `()` during lowering so we have something to refer to here?
+ coerce.coerce(self, *expr, &val_ty);
+ let ctxt = find_breakable(&mut self.breakables, label.as_ref())
+ .expect("breakable stack changed during coercion");
+ ctxt.coerce = coerce;
+ ctxt.may_break = true;
+ }
+ None => {
+ self.push_diagnostic(InferenceDiagnostic::BreakOutsideOfLoop {
+ expr: tgt_expr,
+ is_break: true,
+ });
+ }
+ }
TyKind::Never.intern(Interner)
}
Expr::Return { expr } => {
@@ -794,9 +802,6 @@ impl<'a> InferenceContext<'a> {
None => self.table.new_float_var(),
},
},
- Expr::MacroStmts { tail, statements } => {
- self.infer_block(tgt_expr, statements, *tail, expected)
- }
Expr::Underscore => {
// Underscore expressions may only appear in assignee expressions,
// which are handled by `infer_assignee_expr()`, so any underscore
@@ -1475,4 +1480,20 @@ impl<'a> InferenceContext<'a> {
},
})
}
+
+ fn with_breakable_ctx<T>(
+ &mut self,
+ kind: BreakableKind,
+ ty: Ty,
+ label: Option<LabelId>,
+ cb: impl FnOnce(&mut Self) -> T,
+ ) -> (Option<Ty>, T) {
+ self.breakables.push({
+ let label = label.map(|label| self.body[label].name.clone());
+ BreakableContext { kind, may_break: false, coerce: CoerceMany::new(ty), label }
+ });
+ let res = cb(self);
+ let ctx = self.breakables.pop().expect("breakable stack broken");
+ (ctx.may_break.then(|| ctx.coerce.complete()), res)
+ }
}