fixup no_{core,std} handling code

6 files changed, 200 insertions, 80 deletions

diff --git a/tests/ui/attributes/malformed-no-std.rs b/tests/ui/attributes/malformed-no-std.rs
new file mode 100644
index 00000000000..528ecb549b0
--- /dev/null
+++ b/tests/ui/attributes/malformed-no-std.rs
@@ -0,0 +1,25 @@
+#![feature(no_core)]
+// these all still apply no_std and then later error
+#![no_std = "foo"]
+//~^ ERROR malformed `no_std` attribute input
+#![no_std("bar")]
+//~^ ERROR malformed `no_std` attribute input
+#![no_std(foo = "bar")]
+//~^ ERROR malformed `no_std` attribute input
+#![no_core = "foo"]
+//~^ ERROR malformed `no_core` attribute input
+#![no_core("bar")]
+//~^ ERROR malformed `no_core` attribute input
+#![no_core(foo = "bar")]
+//~^ ERROR malformed `no_core` attribute input
+
+#[deny(unused_attributes)]
+#[no_std]
+//~^ ERROR crate-level attribute should be an inner attribute: add an exclamation mark:
+#[no_core]
+//~^ ERROR crate-level attribute should be an inner attribute: add an exclamation mark:
+// to fix compilation
+extern crate core;
+extern crate std;
+
+fn main() {}
diff --git a/tests/ui/attributes/malformed-no-std.stderr b/tests/ui/attributes/malformed-no-std.stderr
new file mode 100644
index 00000000000..322d5f03e41
--- /dev/null
+++ b/tests/ui/attributes/malformed-no-std.stderr
@@ -0,0 +1,86 @@
+error[E0565]: malformed `no_std` attribute input
+  --> $DIR/malformed-no-std.rs:3:1
+   |
+LL | #![no_std = "foo"]
+   | ^^^^^^^^^^-------^
+   | |         |
+   | |         didn't expect any arguments here
+   | help: must be of the form: `#![no_std]`
+
+error[E0565]: malformed `no_std` attribute input
+  --> $DIR/malformed-no-std.rs:5:1
+   |
+LL | #![no_std("bar")]
+   | ^^^^^^^^^-------^
+   | |        |
+   | |        didn't expect any arguments here
+   | help: must be of the form: `#![no_std]`
+
+error[E0565]: malformed `no_std` attribute input
+  --> $DIR/malformed-no-std.rs:7:1
+   |
+LL | #![no_std(foo = "bar")]
+   | ^^^^^^^^^-------------^
+   | |        |
+   | |        didn't expect any arguments here
+   | help: must be of the form: `#![no_std]`
+
+error[E0565]: malformed `no_core` attribute input
+  --> $DIR/malformed-no-std.rs:9:1
+   |
+LL | #![no_core = "foo"]
+   | ^^^^^^^^^^^-------^
+   | |          |
+   | |          didn't expect any arguments here
+   | help: must be of the form: `#![no_core]`
+
+error[E0565]: malformed `no_core` attribute input
+  --> $DIR/malformed-no-std.rs:11:1
+   |
+LL | #![no_core("bar")]
+   | ^^^^^^^^^^-------^
+   | |         |
+   | |         didn't expect any arguments here
+   | help: must be of the form: `#![no_core]`
+
+error[E0565]: malformed `no_core` attribute input
+  --> $DIR/malformed-no-std.rs:13:1
+   |
+LL | #![no_core(foo = "bar")]
+   | ^^^^^^^^^^-------------^
+   | |         |
+   | |         didn't expect any arguments here
+   | help: must be of the form: `#![no_core]`
+
+error: crate-level attribute should be an inner attribute: add an exclamation mark: `#![no_std]`
+  --> $DIR/malformed-no-std.rs:17:1
+   |
+LL | #[no_std]
+   | ^^^^^^^^^
+   |
+note: This attribute does not have an `!`, which means it is applied to this extern crate
+  --> $DIR/malformed-no-std.rs:22:1
+   |
+LL | extern crate core;
+   | ^^^^^^^^^^^^^^^^^^
+note: the lint level is defined here
+  --> $DIR/malformed-no-std.rs:16:8
+   |
+LL | #[deny(unused_attributes)]
+   |        ^^^^^^^^^^^^^^^^^
+
+error: crate-level attribute should be an inner attribute: add an exclamation mark: `#![no_core]`
+  --> $DIR/malformed-no-std.rs:19:1
+   |
+LL | #[no_core]
+   | ^^^^^^^^^^
+   |
+note: This attribute does not have an `!`, which means it is applied to this extern crate
+  --> $DIR/malformed-no-std.rs:22:1
+   |
+LL | extern crate core;
+   | ^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 8 previous errors
+
+For more information about this error, try `rustc --explain E0565`.
diff --git a/tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs.rs b/tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs.rs
index c2653dd82a9..546aa4052d3 100644
--- a/tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs.rs
+++ b/tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs.rs
@@ -539,26 +539,26 @@ mod macro_escape {
 
 #[no_std]
 //~^ WARN crate-level attribute should be an inner attribute
-//~| HELP add a `!`
 mod no_std {
+    //~^ NOTE This attribute does not have an `!`, which means it is applied to this module
     mod inner { #![no_std] }
-//~^ WARN crate-level attribute should be in the root module
+//~^ WARN the `#![no_std]` attribute can only be used at the crate root
 
     #[no_std] fn f() { }
     //~^ WARN crate-level attribute should be an inner attribute
-    //~| HELP add a `!`
+    //~| NOTE This attribute does not have an `!`, which means it is applied to this function
 
     #[no_std] struct S;
     //~^ WARN crate-level attribute should be an inner attribute
-    //~| HELP add a `!`
+    //~| NOTE This attribute does not have an `!`, which means it is applied to this struct
 
     #[no_std] type T = S;
     //~^ WARN crate-level attribute should be an inner attribute
-    //~| HELP add a `!`
+    //~| NOTE This attribute does not have an `!`, which means it is applied to this type alias
 
     #[no_std] impl S { }
     //~^ WARN crate-level attribute should be an inner attribute
-    //~| HELP add a `!`
+    //~| NOTE This attribute does not have an `!`, which means it is applied to this implementation block
 }
 
 // At time of authorship, #[proc_macro_derive = "2500"] signals error
diff --git a/tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs.stderr b/tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs.stderr
index 4a3520972bf..3c835be5cff 100644
--- a/tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs.stderr
+++ b/tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs.stderr
@@ -209,17 +209,6 @@ help: add a `!`
 LL | #![reexport_test_harness_main = "2900"]
    |  +
 
-warning: crate-level attribute should be an inner attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:540:1
-   |
-LL | #[no_std]
-   | ^^^^^^^^^
-   |
-help: add a `!`
-   |
-LL | #![no_std]
-   |  +
-
 warning: attribute should be applied to an `extern` block with non-Rust ABI
   --> $DIR/issue-43106-gating-of-builtin-attrs.rs:695:1
    |
@@ -387,56 +376,6 @@ help: add a `!`
 LL |     #![reexport_test_harness_main = "2900"] impl S { }
    |      +
 
-warning: crate-level attribute should be in the root module
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:544:17
-   |
-LL |     mod inner { #![no_std] }
-   |                 ^^^^^^^^^^
-
-warning: crate-level attribute should be an inner attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:547:5
-   |
-LL |     #[no_std] fn f() { }
-   |     ^^^^^^^^^
-   |
-help: add a `!`
-   |
-LL |     #![no_std] fn f() { }
-   |      +
-
-warning: crate-level attribute should be an inner attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:551:5
-   |
-LL |     #[no_std] struct S;
-   |     ^^^^^^^^^
-   |
-help: add a `!`
-   |
-LL |     #![no_std] struct S;
-   |      +
-
-warning: crate-level attribute should be an inner attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:555:5
-   |
-LL |     #[no_std] type T = S;
-   |     ^^^^^^^^^
-   |
-help: add a `!`
-   |
-LL |     #![no_std] type T = S;
-   |      +
-
-warning: crate-level attribute should be an inner attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:559:5
-   |
-LL |     #[no_std] impl S { }
-   |     ^^^^^^^^^
-   |
-help: add a `!`
-   |
-LL |     #![no_std] impl S { }
-   |      +
-
 warning: attribute should be applied to an `extern` block with non-Rust ABI
   --> $DIR/issue-43106-gating-of-builtin-attrs.rs:701:17
    |
@@ -1095,6 +1034,76 @@ LL |     #[macro_escape] impl S { }
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = help: `#[macro_escape]` can be applied to modules, extern crates, and crates
 
+warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![no_std]`
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:540:1
+   |
+LL | #[no_std]
+   | ^^^^^^^^^
+   |
+note: This attribute does not have an `!`, which means it is applied to this module
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:542:1
+   |
+LL | / mod no_std {
+LL | |
+LL | |     mod inner { #![no_std] }
+...  |
+LL | | }
+   | |_^
+
+warning: the `#![no_std]` attribute can only be used at the crate root
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:544:17
+   |
+LL |     mod inner { #![no_std] }
+   |                 ^^^^^^^^^^
+
+warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![no_std]`
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:547:5
+   |
+LL |     #[no_std] fn f() { }
+   |     ^^^^^^^^^
+   |
+note: This attribute does not have an `!`, which means it is applied to this function
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:547:15
+   |
+LL |     #[no_std] fn f() { }
+   |               ^^^^^^^^^^
+
+warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![no_std]`
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:551:5
+   |
+LL |     #[no_std] struct S;
+   |     ^^^^^^^^^
+   |
+note: This attribute does not have an `!`, which means it is applied to this struct
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:551:15
+   |
+LL |     #[no_std] struct S;
+   |               ^^^^^^^^^
+
+warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![no_std]`
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:555:5
+   |
+LL |     #[no_std] type T = S;
+   |     ^^^^^^^^^
+   |
+note: This attribute does not have an `!`, which means it is applied to this type alias
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:555:15
+   |
+LL |     #[no_std] type T = S;
+   |               ^^^^^^^^^^^
+
+warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![no_std]`
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:559:5
+   |
+LL |     #[no_std] impl S { }
+   |     ^^^^^^^^^
+   |
+note: This attribute does not have an `!`, which means it is applied to this implementation block
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:559:15
+   |
+LL |     #[no_std] impl S { }
+   |               ^^^^^^^^^^
+
 warning: `#[cold]` attribute cannot be used on modules
   --> $DIR/issue-43106-gating-of-builtin-attrs.rs:581:1
    |
diff --git a/tests/ui/lint/unused/unused-attr-duplicate.stderr b/tests/ui/lint/unused/unused-attr-duplicate.stderr
index 076a08ac6f2..3a3b450f3c5 100644
--- a/tests/ui/lint/unused/unused-attr-duplicate.stderr
+++ b/tests/ui/lint/unused/unused-attr-duplicate.stderr
@@ -29,18 +29,6 @@ LL | #[no_link]
    | ^^^^^^^^^^
 
 error: unused attribute
-  --> $DIR/unused-attr-duplicate.rs:27:1
-   |
-LL | #![no_std]
-   | ^^^^^^^^^^ help: remove this attribute
-   |
-note: attribute also specified here
-  --> $DIR/unused-attr-duplicate.rs:26:1
-   |
-LL | #![no_std]
-   | ^^^^^^^^^^
-
-error: unused attribute
   --> $DIR/unused-attr-duplicate.rs:31:1
    |
 LL | #![windows_subsystem = "windows"]
@@ -305,6 +293,18 @@ LL | #![type_length_limit = "1048576"]
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 error: unused attribute
+  --> $DIR/unused-attr-duplicate.rs:27:1
+   |
+LL | #![no_std]
+   | ^^^^^^^^^^ help: remove this attribute
+   |
+note: attribute also specified here
+  --> $DIR/unused-attr-duplicate.rs:26:1
+   |
+LL | #![no_std]
+   | ^^^^^^^^^^
+
+error: unused attribute
   --> $DIR/unused-attr-duplicate.rs:29:1
    |
 LL | #![no_implicit_prelude]
diff --git a/tests/ui/unpretty/exhaustive.hir.stdout b/tests/ui/unpretty/exhaustive.hir.stdout
index 924fb98ae18..96d85d1e7c1 100644
--- a/tests/ui/unpretty/exhaustive.hir.stdout
+++ b/tests/ui/unpretty/exhaustive.hir.stdout
@@ -55,7 +55,7 @@ use self::prelude::*;
      */
 #[doc = "inner doc attribute"]
 #[allow(dead_code, unused_variables)]
-#[no_std]
+#[attr = NoStd]
 mod attributes {
 
     /// outer single-line doc comment