Use yield_expr feature for iter_macro tests

Author: eholk

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -468,11 +468,12 @@ pub fn check_crate(krate: &ast::Crate, sess: &Session, features: &Features) {
         for span in spans {
             if (!visitor.features.coroutines() && !span.allows_unstable(sym::coroutines))
                 && (!visitor.features.gen_blocks() && !span.allows_unstable(sym::gen_blocks))
+                && (!visitor.features.yield_expr() && !span.allows_unstable(sym::yield_expr))
             {
                 #[allow(rustc::untranslatable_diagnostic)]
-                // Don't know which of the two features to include in the
-                // error message, so I am arbitrarily picking one.
-                feature_err(&visitor.sess, sym::coroutines, *span, "yield syntax is experimental")
+                // Emit yield_expr as the error, since that will be sufficient. You can think of it
+                // as coroutines and gen_blocks imply yield_expr.
+                feature_err(&visitor.sess, sym::yield_expr, *span, "yield syntax is experimental")
                     .emit();
             }
         }

tests/ui/iterators/generator.rs

@@ -1,8 +1,6 @@
 //@ run-pass
 
-#![feature(iter_macro)]
-// FIXME(iter_macro): make `yield` within it legal
-#![feature(coroutines)]
+#![feature(iter_macro, yield_expr)]
 
 use std::iter::iter;
 

tests/ui/iterators/generator_args.rs

@@ -1,8 +1,6 @@
 //@ run-pass
 
-#![feature(iter_macro)]
-// FIXME(iter_macro): make `yield` within it legal
-#![feature(coroutines)]
+#![feature(iter_macro, yield_expr)]
 
 use std::iter::iter;
 

tests/ui/iterators/generator_capture.rs

@@ -1,8 +1,6 @@
 //@ run-pass
 
-#![feature(iter_macro)]
-// FIXME(iter_macro): make `yield` within it legal
-#![feature(coroutines)]
+#![feature(iter_macro, yield_expr)]
 
 use std::iter::iter;
 

tests/ui/iterators/generator_capture_.rs

@@ -1,8 +1,6 @@
 //@ run-pass
 
-#![feature(iter_macro)]
-// FIXME(iter_macro): make `yield` within it legal
-#![feature(coroutines)]
+#![feature(iter_macro, yield_expr)]
 
 use std::iter::iter;
 

tests/ui/iterators/generator_capture_fail.rs

@@ -1,6 +1,4 @@
-#![feature(iter_macro)]
-// FIXME(iter_macro): make `yield` within it legal
-#![feature(coroutines)]
+#![feature(iter_macro, yield_expr)]
 
 use std::iter::iter;
 

tests/ui/iterators/generator_capture_fail.stderr

@@ -1,5 +1,5 @@
 error[E0597]: `s` does not live long enough
-  --> $DIR/generator_capture_fail.rs:11:13
+  --> $DIR/generator_capture_fail.rs:9:13
    |
 LL |       let i = {
    |           - borrow later stored here

tests/ui/iterators/generator_returned_from_fn.rs

@@ -1,6 +1,4 @@
-#![feature(iter_macro, impl_trait_in_fn_trait_return)]
-// FIXME(iter_macro): make `yield` within it legal
-#![feature(coroutines)]
+#![feature(iter_macro, impl_trait_in_fn_trait_return, yield_expr)]
 
 use std::iter::iter;
 

tests/ui/iterators/generator_returned_from_fn.stderr

@@ -1,5 +1,5 @@
 error[E0515]: cannot return reference to function parameter `a`
-  --> $DIR/generator_returned_from_fn.rs:26:13
+  --> $DIR/generator_returned_from_fn.rs:24:13
    |
 LL |       iter! { || {
    |  _____________^
@@ -11,7 +11,7 @@ LL | |     } }
    | |_____^ returns a reference to data owned by the current function
 
 error: `gen` closure does not implement `Fn` because it captures state from its environment
-  --> $DIR/generator_returned_from_fn.rs:35:13
+  --> $DIR/generator_returned_from_fn.rs:33:13
    |
 LL |       iter! { move || {
    |  _____________-^^^^^^
@@ -20,15 +20,15 @@ LL | |         for x in 5..10 {
 LL | |             yield x * 2;
 LL | |         }
 LL | |     } }
-   | |_____- return type was inferred to be `{gen closure@$DIR/generator_returned_from_fn.rs:35:13: 35:20}` here
+   | |_____- return type was inferred to be `{gen closure@$DIR/generator_returned_from_fn.rs:33:13: 33:20}` here
 
 error[E0700]: hidden type for `impl FnOnce() -> impl Iterator<Item = u32>` captures lifetime that does not appear in bounds
-  --> $DIR/generator_returned_from_fn.rs:44:13
+  --> $DIR/generator_returned_from_fn.rs:42:13
    |
 LL |   fn capture_move_once(a: &u32) -> impl FnOnce() -> impl Iterator<Item = u32> {
    |                           ----     ------------------------------------------ opaque type defined here
    |                           |
-   |                           hidden type `{gen closure@$DIR/generator_returned_from_fn.rs:44:13: 44:20}` captures the anonymous lifetime defined here
+   |                           hidden type `{gen closure@$DIR/generator_returned_from_fn.rs:42:13: 42:20}` captures the anonymous lifetime defined here
 LL |       iter! { move || {
    |  _____________^
 LL | |
@@ -44,12 +44,12 @@ LL | fn capture_move_once(a: &u32) -> impl FnOnce() -> impl Iterator<Item = u32>
    |                                                                             +++++++++
 
 error[E0700]: hidden type for `impl Iterator<Item = u32>` captures lifetime that does not appear in bounds
-  --> $DIR/generator_returned_from_fn.rs:44:13
+  --> $DIR/generator_returned_from_fn.rs:42:13
    |
 LL |   fn capture_move_once(a: &u32) -> impl FnOnce() -> impl Iterator<Item = u32> {
    |                           ----                      ------------------------- opaque type defined here
    |                           |
-   |                           hidden type `{gen closure body@$DIR/generator_returned_from_fn.rs:44:21: 51:6}` captures the anonymous lifetime defined here
+   |                           hidden type `{gen closure body@$DIR/generator_returned_from_fn.rs:42:21: 49:6}` captures the anonymous lifetime defined here
 LL |       iter! { move || {
    |  _____________^
 LL | |