From 0471e2780fe528dae8b67ea3448e8ab641e8510e Mon Sep 17 00:00:00 2001 From: Yiming Lei Date: Tue, 9 Aug 2022 11:27:04 -0700 Subject: when there are 3 or more return statements in the loop emit the first 3 errors and duplicated diagnostic information using take of iterator for the first third return modified: compiler/rustc_typeck/src/check/coercion.rs new file: src/test/ui/typeck/issue-100285.rs new file: src/test/ui/typeck/issue-100285.stderr --- src/test/ui/typeck/issue-100285.rs | 22 ++++++++++++++++++++++ src/test/ui/typeck/issue-100285.stderr | 34 ++++++++++++++++++++++++++++++++++ 2 files changed, 56 insertions(+) create mode 100644 src/test/ui/typeck/issue-100285.rs create mode 100644 src/test/ui/typeck/issue-100285.stderr (limited to 'src') diff --git a/src/test/ui/typeck/issue-100285.rs b/src/test/ui/typeck/issue-100285.rs new file mode 100644 index 00000000000..e206469b85f --- /dev/null +++ b/src/test/ui/typeck/issue-100285.rs @@ -0,0 +1,22 @@ +fn foo(n: i32) -> i32 { + for i in 0..0 { + //~^ ERROR: mismatched types [E0308] + if n < 0 { + return i; + } else if n < 10 { + return 1; + } else if n < 20 { + return 2; + } else if n < 30 { + return 3; + } else if n < 40 { + return 4; + } else { + return 5; + } + + } + //~| help: return a value for the case when the loop has zero elements to iterate on, or consider changing the return type to account for that possibility +} + +fn main() {} diff --git a/src/test/ui/typeck/issue-100285.stderr b/src/test/ui/typeck/issue-100285.stderr new file mode 100644 index 00000000000..42c64b03918 --- /dev/null +++ b/src/test/ui/typeck/issue-100285.stderr @@ -0,0 +1,34 @@ +error[E0308]: mismatched types + --> $DIR/issue-100285.rs:2:5 + | +LL | fn foo(n: i32) -> i32 { + | --- expected `i32` because of return type +LL | / for i in 0..0 { +LL | | +LL | | if n < 0 { +LL | | return i; +... | +LL | | +LL | | } + | |_____^ expected `i32`, found `()` + | +note: the function expects a value to always be returned, but loops might run zero times + --> $DIR/issue-100285.rs:2:5 + | +LL | for i in 0..0 { + | ^^^^^^^^^^^^^ this might have zero elements to iterate on +... +LL | return i; + | -------- if the loop doesn't execute, this value would never get returned +LL | } else if n < 10 { +LL | return 1; + | -------- if the loop doesn't execute, this value would never get returned +LL | } else if n < 20 { +LL | return 2; + | -------- if the loop doesn't execute, this value would never get returned + = note: if the loop doesn't execute, 3 other values would never get returned + = help: return a value for the case when the loop has zero elements to iterate on, or consider changing the return type to account for that possibility + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0308`. -- cgit 1.4.1-3-g733a5