Tidying up UI tests [6/N]

src/tools/tidy/src/issues.txt

@@ -1014,7 +1014,6 @@ ui/for-loop-while/issue-1257.rs
 ui/for-loop-while/issue-2216.rs
 ui/for-loop-while/issue-51345.rs
 ui/for-loop-while/issue-69841.rs
-ui/for/issue-20605.rs
 ui/foreign/issue-74120-lowering-of-ffi-block-bodies.rs
 ui/foreign/issue-91370-foreign-fn-block-impl.rs
 ui/foreign/issue-99276-same-type-lifetimes.rs

tests/ui/README.md

@@ -585,12 +585,6 @@ Exercises the `format!` macro.
 
 A broad category of tests on functions.
 
-## `tests/ui/for/`: `for` keyword
-
-Tests on the `for` keyword and some of its associated errors, such as attempting to write the faulty pattern `for _ in 0..1 {} else {}`.
-
-**FIXME**: Should be merged with `ui/for-loop-while`.
-
 ## `tests/ui/force-inlining/`: `#[rustc_force_inline]`
 
 Tests for `#[rustc_force_inline]`, which will force a function to always be labelled as inline by the compiler (it will be inserted at the point of its call instead of being used as a normal function call.) If the compiler is unable to inline the function, an error will be reported. See <https://github.com/rust-lang/rust/pull/134082>.
@@ -1545,10 +1539,6 @@ Tests on `enum` variants.
 
 **FIXME**: Contains a single test described as "Check that rustc accepts various version info flags.", should be rehomed.
 
-## `tests/ui/warnings/`
-
-**FIXME**: Contains a single test on non-explicit paths (`::one()`). Should be rehomed probably to `tests/ui/resolve/`.
-
 ## `tests/ui/wasm/`
 
 These tests target the `wasm32` architecture specifically. They are usually regression tests for WASM-specific bugs which were observed in the past.

tests/ui/for/for-c-in-str.rs → tests/ui/for-loop-while/for-c-in-str.rs

@@ -1,4 +1,5 @@
-// E0277 should point exclusively at line 6, not the entire for loop span
+//! Tests that the E0277 error span, generated by the `for` loop desugaring,
+//! points exclusively to the loop header expression and not the full loop block.
 
 fn main() {
     for c in "asdf" {

tests/ui/for/for-c-in-str.stderr → tests/ui/for-loop-while/for-c-in-str.stderr

@@ -1,5 +1,5 @@
 error[E0277]: `&str` is not an iterator
-  --> $DIR/for-c-in-str.rs:4:14
+  --> $DIR/for-c-in-str.rs:5:14
    |
 LL |     for c in "asdf" {
    |              ^^^^^^ `&str` is not an iterator; try calling `.chars()` or `.bytes()`

tests/ui/for-loop-while/for-loop-bogosity.rs

@@ -0,0 +1,21 @@
+//! Tests that a struct with a `next` method but without the `Iterator` trait
+//! implementation yields an error in a `for` loop.
+
+struct MyStruct {
+    x: isize,
+    y: isize,
+}
+
+impl MyStruct {
+    fn next(&mut self) -> Option<isize> {
+        Some(self.x)
+    }
+}
+
+pub fn main() {
+    let mut bogus = MyStruct { x: 1, y: 2 };
+    for x in bogus {
+        //~^ ERROR `MyStruct` is not an iterator
+        drop(x);
+    }
+}

tests/ui/for/for-loop-bogosity.stderr → tests/ui/for-loop-while/for-loop-bogosity.stderr

@@ -5,7 +5,7 @@ LL |     for x in bogus {
    |              ^^^^^ `MyStruct` is not an iterator
    |
 help: the trait `Iterator` is not implemented for `MyStruct`
-  --> $DIR/for-loop-bogosity.rs:1:1
+  --> $DIR/for-loop-bogosity.rs:4:1
    |
 LL | struct MyStruct {
    | ^^^^^^^^^^^^^^^

tests/ui/for/for-expn.stderr → tests/ui/for-loop-while/for-loop-diagnostic-span.stderr

@@ -1,5 +1,5 @@
 error[E0425]: cannot find value `foo` in this scope
-  --> $DIR/for-expn.rs:6:7
+  --> $DIR/for-loop-diagnostic-span.rs:6:7
    |
 LL |       foo
    |       ^^^ not found in this scope

tests/ui/for/for-loop-type-error.rs → tests/ui/for-loop-while/for-loop-type-error.rs

@@ -1,3 +1,5 @@
+//! regression test for issue <https://github.com/rust-lang/rust/issues/16042>
+
 pub fn main() {
     let x = () + (); //~ ERROR cannot add `()` to `()`
 

tests/ui/for/for-loop-type-error.stderr → tests/ui/for-loop-while/for-loop-type-error.stderr

@@ -1,5 +1,5 @@
 error[E0369]: cannot add `()` to `()`
-  --> $DIR/for-loop-type-error.rs:2:16
+  --> $DIR/for-loop-type-error.rs:4:16
    |
 LL |     let x = () + ();
    |             -- ^ -- ()

tests/ui/for/for-loop-unconstrained-element-type.rs → tests/ui/for-loop-while/for-loop-unconstrained-element-type.rs

@@ -3,7 +3,8 @@
 // Subtle changes in the desugaring can cause the
 // type of elements in the vector to (incorrectly)
 // fallback to `!` or `()`.
+// regression test for issue <https://github.com/rust-lang/rust/issues/42618>
 
 fn main() {
-    for i in Vec::new() { } //~ ERROR type annotations needed
+    for i in Vec::new() {} //~ ERROR type annotations needed
 }

tests/ui/for/for-loop-unconstrained-element-type.stderr → tests/ui/for-loop-while/for-loop-unconstrained-element-type.stderr

@@ -1,12 +1,12 @@
 error[E0282]: type annotations needed
-  --> $DIR/for-loop-unconstrained-element-type.rs:8:14
+  --> $DIR/for-loop-unconstrained-element-type.rs:9:14
    |
-LL |     for i in Vec::new() { }
+LL |     for i in Vec::new() {}
    |              ^^^^^^^^ cannot infer type of the type parameter `T` declared on the struct `Vec`
    |
 help: consider specifying the generic argument
    |
-LL |     for i in Vec::<T>::new() { }
+LL |     for i in Vec::<T>::new() {}
    |                 +++++
 
 error: aborting due to 1 previous error

tests/ui/warnings/no-explicit-path-issue-122509.rs → tests/ui/resolve/no-explicit-path.rs

@@ -1,3 +1,4 @@
+//! regression test for issue <https://github.com/rust-lang/rust/issues/122509>
 //@ build-pass
 //@ compile-flags: -C codegen-units=2 --emit asm
 

tests/ui/for/issue-20605.current.stderr → tests/ui/traits/dyn-iterator-deref-in-for-loop.current.stderr

@@ -1,14 +1,14 @@
 error[E0277]: `dyn Iterator<Item = &'a mut u8>` is not an iterator
-  --> $DIR/issue-20605.rs:6:17
+  --> $DIR/dyn-iterator-deref-in-for-loop.rs:9:17
    |
-LL |     for item in *things { *item = 0 }
+LL |     for item in *things {
    |                 ^^^^^^^ the trait `IntoIterator` is not implemented for `dyn Iterator<Item = &'a mut u8>`
    |
    = note: the trait bound `dyn Iterator<Item = &'a mut u8>: IntoIterator` is not satisfied
    = note: required for `dyn Iterator<Item = &'a mut u8>` to implement `IntoIterator`
 help: consider mutably borrowing here
    |
-LL |     for item in &mut *things { *item = 0 }
+LL |     for item in &mut *things {
    |                 ++++
 
 error: aborting due to 1 previous error

tests/ui/for/issue-20605.next.stderr → tests/ui/traits/dyn-iterator-deref-in-for-loop.next.stderr

@@ -1,14 +1,14 @@
 error[E0277]: `dyn Iterator<Item = &'a mut u8>` is not an iterator
-  --> $DIR/issue-20605.rs:6:17
+  --> $DIR/dyn-iterator-deref-in-for-loop.rs:9:17
    |
-LL |     for item in *things { *item = 0 }
+LL |     for item in *things {
    |                 ^^^^^^^ the trait `IntoIterator` is not implemented for `dyn Iterator<Item = &'a mut u8>`
    |
    = note: the trait bound `dyn Iterator<Item = &'a mut u8>: IntoIterator` is not satisfied
    = note: required for `dyn Iterator<Item = &'a mut u8>` to implement `IntoIterator`
 help: consider mutably borrowing here
    |
-LL |     for item in &mut *things { *item = 0 }
+LL |     for item in &mut *things {
    |                 ++++
 
 error: aborting due to 1 previous error

tests/ui/traits/dyn-iterator-deref-in-for-loop.rs

@@ -0,0 +1,15 @@
+//! Tests that dereferencing a Box<dyn Iterator> in a for loop correctly yields an error,
+//! as the unsized trait object does not implement IntoIterator.
+//! regression test for <https://github.com/rust-lang/rust/issues/20605>
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
+
+fn changer<'a>(mut things: Box<dyn Iterator<Item = &'a mut u8>>) {
+    for item in *things {
+        //~^ ERROR `dyn Iterator<Item = &'a mut u8>` is not an iterator
+        *item = 0
+    }
+}
+
+fn main() {}