From 378ec2841bf344c05fe6119c0013edeabcf33a35 Mon Sep 17 00:00:00 2001
From: Lukas Wirth <lukastw97@gmail.com>
Date: Sat, 12 Dec 2020 00:03:36 +0100
Subject: Infer labeled blocks
---
crates/hir_ty/src/infer/expr.rs | 22 ++++++++++++---
crates/hir_ty/src/tests/simple.rs | 56 +++++++++++++++++++++++++++++++++++++++
2 files changed, 74 insertions(+), 4 deletions(-)
diff --git a/crates/hir_ty/src/infer/expr.rs b/crates/hir_ty/src/infer/expr.rs
index 605951b10..d7ad198b3 100644
--- a/crates/hir_ty/src/infer/expr.rs
+++ b/crates/hir_ty/src/infer/expr.rs
@@ -137,10 +137,24 @@ impl<'a> InferenceContext<'a> {
self.coerce_merge_branch(&then_ty, &else_ty)
}
- Expr::Block { statements, tail, .. } => {
- // FIXME: Breakable block inference
- self.infer_block(statements, *tail, expected)
- }
+ Expr::Block { statements, tail, label } => match label {
+ Some(_) => {
+ let break_ty = self.table.new_type_var();
+ self.breakables.push(BreakableContext {
+ may_break: false,
+ break_ty: break_ty.clone(),
+ label: label.clone(),
+ });
+ let ty = self.infer_block(statements, *tail, &Expectation::has_type(break_ty));
+ let ctxt = self.breakables.pop().expect("breakable stack broken");
+ if ctxt.may_break {
+ ctxt.break_ty
+ } else {
+ ty
+ }
+ }
+ None => self.infer_block(statements, *tail, expected),
+ },
Expr::Unsafe { body } => self.infer_expr(*body, expected),
Expr::TryBlock { body } => {
let _inner = self.infer_expr(*body, expected);
diff --git a/crates/hir_ty/src/tests/simple.rs b/crates/hir_ty/src/tests/simple.rs
index 4f72582b6..a569223b4 100644
--- a/crates/hir_ty/src/tests/simple.rs
+++ b/crates/hir_ty/src/tests/simple.rs
@@ -2074,6 +2074,62 @@ fn infer_labelled_break_with_val() {
);
}
+#[test]
+fn infer_labelled_block_break_with_val() {
+ check_infer(
+ r#"
+ fn default<T>() -> T { loop {} }
+ fn foo() {
+ let _x = 'outer: {
+ let inner = 'inner: {
+ let i = default();
+ if (break 'outer i) {
+ break 'inner 5i8;
+ } else if true {
+ break 'inner 6;
+ }
+ break 'inner 'innermost: { 0 };
+ 42
+ };
+ break 'outer inner < 8;
+ };
+ }
+ "#,
+ expect![[r#"
+ 21..32 '{ loop {} }': T
+ 23..30 'loop {}': !
+ 28..30 '{}': ()
+ 42..381 '{ ... }; }': ()
+ 52..54 '_x': bool
+ 65..378 '{ ... }': bool
+ 79..84 'inner': i8
+ 95..339 '{ ... }': i8
+ 113..114 'i': bool
+ 117..124 'default': fn default<bool>() -> bool
+ 117..126 'default()': bool
+ 140..270 'if (br... }': ()
+ 144..158 'break 'outer i': !
+ 157..158 'i': bool
+ 160..209 '{ ... }': ()
+ 178..194 'break ...er 5i8': !
+ 191..194 '5i8': i8
+ 215..270 'if tru... }': ()
+ 218..222 'true': bool
+ 223..270 '{ ... }': ()
+ 241..255 'break 'inner 6': !
+ 254..255 '6': i8
+ 283..313 'break ... { 0 }': !
+ 308..313 '{ 0 }': i8
+ 310..311 '0': i8
+ 327..329 '42': i8
+ 349..371 'break ...er < 8': !
+ 362..367 'inner': i8
+ 362..371 'inner < 8': bool
+ 370..371 '8': i8
+ "#]],
+ );
+}
+
#[test]
fn generic_default() {
check_infer(
--
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