Rollup merge of #54862 - Havvy:cfg_attr_multi, r=petrochenkov

Fixes #47311.
r? @nrc

src/test/ui/cfg-attr-trailing-comma.rs

@@ -1,13 +0,0 @@
-// compile-flags: --cfg TRUE
-
-#[cfg_attr(TRUE, inline,)] // OK
-fn f() {}
-
-#[cfg_attr(FALSE, inline,)] // OK
-fn g() {}
-
-#[cfg_attr(TRUE, inline,,)] //~ ERROR expected `)`, found `,`
-fn h() {}
-
-#[cfg_attr(FALSE, inline,,)] //~ ERROR expected `)`, found `,`
-fn i() {}

src/test/ui/cfg-attr-trailing-comma.stderr

@@ -1,14 +0,0 @@
-error: expected `)`, found `,`
-  --> $DIR/cfg-attr-trailing-comma.rs:9:25
-   |
-LL | #[cfg_attr(TRUE, inline,,)] //~ ERROR expected `)`, found `,`
-   |                         ^ expected `)`
-
-error: expected `)`, found `,`
-  --> $DIR/cfg-attr-trailing-comma.rs:12:26
-   |
-LL | #[cfg_attr(FALSE, inline,,)] //~ ERROR expected `)`, found `,`
-   |                          ^ expected `)`
-
-error: aborting due to 2 previous errors
-

src/test/ui/conditional-compilation/cfg-attr-crate-2.stderr

@@ -2,7 +2,7 @@ error[E0658]: no_core is experimental (see issue #29639)
   --> $DIR/cfg-attr-crate-2.rs:15:21
    |
 LL | #![cfg_attr(broken, no_core)] //~ ERROR no_core is experimental
-   |                     ^^^^^^^^
+   |                     ^^^^^^^
    |
    = help: add #![feature(no_core)] to the crate attributes to enable
 

src/test/ui/conditional-compilation/cfg-attr-multi-false.rs

@@ -0,0 +1,20 @@
+// Test that cfg_attr doesn't emit any attributes when the
+// configuation variable is false. This mirrors `cfg-attr-multi-true.rs`
+
+// compile-pass
+
+#![warn(unused_must_use)]
+#![feature(cfg_attr_multi)]
+
+#[cfg_attr(any(), deprecated, must_use)]
+struct Struct {}
+
+impl Struct {
+    fn new() -> Struct {
+        Struct {}
+    }
+}
+
+fn main() {
+    Struct::new();
+}

src/test/ui/conditional-compilation/cfg-attr-multi-invalid-1.rs

@@ -0,0 +1,16 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+//
+// compile-flags: --cfg broken
+
+#![feature(cfg_attr_multi)]
+#![cfg_attr(broken, no_core, no_std)] //~ ERROR no_core is experimental
+
+fn main() { }

src/test/ui/conditional-compilation/cfg-attr-multi-invalid-1.stderr

@@ -0,0 +1,11 @@
+error[E0658]: no_core is experimental (see issue #29639)
+  --> $DIR/cfg-attr-multi-invalid-1.rs:14:21
+   |
+LL | #![cfg_attr(broken, no_core, no_std)] //~ ERROR no_core is experimental
+   |                     ^^^^^^^
+   |
+   = help: add #![feature(no_core)] to the crate attributes to enable
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0658`.

src/test/ui/conditional-compilation/cfg-attr-multi-invalid-2.rs

@@ -0,0 +1,16 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+//
+// compile-flags: --cfg broken
+
+#![feature(cfg_attr_multi)]
+#![cfg_attr(broken, no_std, no_core)] //~ ERROR no_core is experimental
+
+fn main() { }

src/test/ui/conditional-compilation/cfg-attr-multi-invalid-2.stderr

@@ -0,0 +1,11 @@
+error[E0658]: no_core is experimental (see issue #29639)
+  --> $DIR/cfg-attr-multi-invalid-2.rs:14:29
+   |
+LL | #![cfg_attr(broken, no_std, no_core)] //~ ERROR no_core is experimental
+   |                             ^^^^^^^
+   |
+   = help: add #![feature(no_core)] to the crate attributes to enable
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0658`.

src/test/ui/conditional-compilation/cfg-attr-multi-true.rs

@@ -0,0 +1,22 @@
+// Test that cfg_attr with multiple attributes actually emits both attributes.
+// This is done by emitting two attributes that cause new warnings, and then
+// triggering those warnings.
+
+// compile-pass
+
+#![warn(unused_must_use)]
+#![feature(cfg_attr_multi)]
+
+#[cfg_attr(all(), deprecated, must_use)]
+struct MustUseDeprecated {}
+
+impl MustUseDeprecated { //~ warning: use of deprecated item
+    fn new() -> MustUseDeprecated { //~ warning: use of deprecated item
+        MustUseDeprecated {} //~ warning: use of deprecated item
+    }
+}
+
+fn main() {
+    MustUseDeprecated::new(); //~ warning: use of deprecated item
+    //| warning: unused `MustUseDeprecated` which must be used
+}

src/test/ui/conditional-compilation/cfg-attr-multi-true.stderr

@@ -0,0 +1,38 @@
+warning: use of deprecated item 'MustUseDeprecated'
+  --> $DIR/cfg-attr-multi-true.rs:13:6
+   |
+LL | impl MustUseDeprecated { //~ warning: use of deprecated item
+   |      ^^^^^^^^^^^^^^^^^
+   |
+   = note: #[warn(deprecated)] on by default
+
+warning: use of deprecated item 'MustUseDeprecated'
+  --> $DIR/cfg-attr-multi-true.rs:20:5
+   |
+LL |     MustUseDeprecated::new(); //~ warning: use of deprecated item
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+
+warning: use of deprecated item 'MustUseDeprecated'
+  --> $DIR/cfg-attr-multi-true.rs:14:17
+   |
+LL |     fn new() -> MustUseDeprecated { //~ warning: use of deprecated item
+   |                 ^^^^^^^^^^^^^^^^^
+
+warning: use of deprecated item 'MustUseDeprecated'
+  --> $DIR/cfg-attr-multi-true.rs:15:9
+   |
+LL |         MustUseDeprecated {} //~ warning: use of deprecated item
+   |         ^^^^^^^^^^^^^^^^^
+
+warning: unused `MustUseDeprecated` which must be used
+  --> $DIR/cfg-attr-multi-true.rs:20:5
+   |
+LL |     MustUseDeprecated::new(); //~ warning: use of deprecated item
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: lint level defined here
+  --> $DIR/cfg-attr-multi-true.rs:7:9
+   |
+LL | #![warn(unused_must_use)]
+   |         ^^^^^^^^^^^^^^^
+

src/test/ui/conditional-compilation/cfg-attr-parse.rs

@@ -0,0 +1,45 @@
+// Parse `cfg_attr` with varying numbers of attributes and trailing commas
+
+#![feature(cfg_attr_multi)]
+
+// Completely empty `cfg_attr` input
+#[cfg_attr()] //~ error: expected identifier, found `)`
+struct NoConfigurationPredicate;
+
+// Zero attributes, zero trailing comma (comma manatory here)
+#[cfg_attr(all())] //~ error: expected `,`, found `)`
+struct A0C0;
+
+// Zero attributes, one trailing comma
+#[cfg_attr(all(),)] // Ok
+struct A0C1;
+
+// Zero attributes, two trailing commas
+#[cfg_attr(all(),,)] //~ ERROR expected identifier
+struct A0C2;
+
+// One attribute, no trailing comma
+#[cfg_attr(all(), must_use)] // Ok
+struct A1C0;
+
+// One attribute, one trailing comma
+#[cfg_attr(all(), must_use,)] // Ok
+struct A1C1;
+
+// One attribute, two trailing commas
+#[cfg_attr(all(), must_use,,)] //~ ERROR expected identifier
+struct A1C2;
+
+// Two attributes, no trailing comma
+#[cfg_attr(all(), must_use, deprecated)] // Ok
+struct A2C0;
+
+// Two attributes, one trailing comma
+#[cfg_attr(all(), must_use, deprecated,)] // Ok
+struct A2C1;
+
+// Two attributes, two trailing commas
+#[cfg_attr(all(), must_use, deprecated,,)] //~ ERROR expected identifier
+struct A2C2;
+
+fn main() {}

src/test/ui/conditional-compilation/cfg-attr-parse.stderr

@@ -0,0 +1,32 @@
+error: expected identifier, found `)`
+  --> $DIR/cfg-attr-parse.rs:6:12
+   |
+LL | #[cfg_attr()] //~ error: expected identifier, found `)`
+   |            ^ expected identifier
+
+error: expected `,`, found `)`
+  --> $DIR/cfg-attr-parse.rs:10:17
+   |
+LL | #[cfg_attr(all())] //~ error: expected `,`, found `)`
+   |                 ^ expected `,`
+
+error: expected identifier, found `,`
+  --> $DIR/cfg-attr-parse.rs:18:18
+   |
+LL | #[cfg_attr(all(),,)] //~ ERROR expected identifier
+   |                  ^ expected identifier
+
+error: expected identifier, found `,`
+  --> $DIR/cfg-attr-parse.rs:30:28
+   |
+LL | #[cfg_attr(all(), must_use,,)] //~ ERROR expected identifier
+   |                            ^ expected identifier
+
+error: expected identifier, found `,`
+  --> $DIR/cfg-attr-parse.rs:42:40
+   |
+LL | #[cfg_attr(all(), must_use, deprecated,,)] //~ ERROR expected identifier
+   |                                        ^ expected identifier
+
+error: aborting due to 5 previous errors
+

src/test/ui/feature-gates/feature-gate-cfg-attr-multi-1.rs

@@ -0,0 +1,5 @@
+// gate-test-cfg_attr_multi
+
+#![cfg_attr(all(), warn(nonstandard_style), allow(unused_attributes))]
+//~^ ERROR cfg_attr with zero or more than one attributes is experimental
+fn main() {}

src/test/ui/feature-gates/feature-gate-cfg-attr-multi-1.stderr

@@ -0,0 +1,11 @@
+error[E0658]: cfg_attr with zero or more than one attributes is experimental (see issue #54881)
+  --> $DIR/feature-gate-cfg-attr-multi-1.rs:3:1
+   |
+LL | #![cfg_attr(all(), warn(nonstandard_style), allow(unused_attributes))]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: add #![feature(cfg_attr_multi)] to the crate attributes to enable
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0658`.

src/test/ui/feature-gates/feature-gate-cfg-attr-multi-2.rs

@@ -0,0 +1,3 @@
+#![cfg_attr(all(),)]
+//~^ ERROR cfg_attr with zero or more than one attributes is experimental
+fn main() {}

src/test/ui/feature-gates/feature-gate-cfg-attr-multi-2.stderr

@@ -0,0 +1,11 @@
+error[E0658]: cfg_attr with zero or more than one attributes is experimental (see issue #54881)
+  --> $DIR/feature-gate-cfg-attr-multi-2.rs:1:1
+   |
+LL | #![cfg_attr(all(),)]
+   | ^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: add #![feature(cfg_attr_multi)] to the crate attributes to enable
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0658`.

src/test/ui/feature-gates/feature-gate-cfg-attr-multi-bootstrap-1.rs

@@ -0,0 +1,7 @@
+// Test that settingt the featute gate while using its functionality doesn't error.
+
+// compile-pass
+
+#![cfg_attr(all(), feature(cfg_attr_multi), crate_type="bin")]
+
+fn main() {}

src/test/ui/feature-gates/feature-gate-cfg-attr-multi-bootstrap-2.rs

@@ -0,0 +1,9 @@
+// Test that settingt the featute gate while using its functionality doesn't error.
+// Specifically, if there's a cfg-attr *before* the feature gate.
+
+// compile-pass
+
+#![cfg_attr(all(),)]
+#![cfg_attr(all(), feature(cfg_attr_multi), crate_type="bin")]
+
+fn main() {}