Add tests for #[doc(keyword = "...")] and update other doc attributes tests

Author: GuillaumeGomez

Diff for: src/test/rustdoc-ui/check-doc-alias-attr.stderr

@@ -1,16 +1,16 @@
-error: doc alias attribute expects a string: #[doc(alias = "0")]
+error: doc alias attribute expects a string: #[doc(alias = "a")]
   --> $DIR/check-doc-alias-attr.rs:6:7
    |
 LL | #[doc(alias)]
    |       ^^^^^
 
-error: doc alias attribute expects a string: #[doc(alias = "0")]
+error: doc alias attribute expects a string: #[doc(alias = "a")]
   --> $DIR/check-doc-alias-attr.rs:7:7
    |
 LL | #[doc(alias = 0)]
    |       ^^^^^^^^^
 
-error: doc alias attribute expects a string: #[doc(alias = "0")]
+error: doc alias attribute expects a string: #[doc(alias = "a")]
   --> $DIR/check-doc-alias-attr.rs:8:7
    |
 LL | #[doc(alias("bar"))]

Diff for: src/test/ui/check-doc-alias-attr.stderr

@@ -1,16 +1,16 @@
-error: doc alias attribute expects a string: #[doc(alias = "0")]
+error: doc alias attribute expects a string: #[doc(alias = "a")]
   --> $DIR/check-doc-alias-attr.rs:7:7
    |
 LL | #[doc(alias)]
    |       ^^^^^
 
-error: doc alias attribute expects a string: #[doc(alias = "0")]
+error: doc alias attribute expects a string: #[doc(alias = "a")]
   --> $DIR/check-doc-alias-attr.rs:8:7
    |
 LL | #[doc(alias = 0)]
    |       ^^^^^^^^^
 
-error: doc alias attribute expects a string: #[doc(alias = "0")]
+error: doc alias attribute expects a string: #[doc(alias = "a")]
   --> $DIR/check-doc-alias-attr.rs:9:7
    |
 LL | #[doc(alias("bar"))]

Diff for: src/test/ui/doc-alias-crate-level.rs

@@ -4,4 +4,7 @@
 
 #![crate_type = "lib"]
 
-#![doc(alias = "shouldn't work!")] //~ ERROR
+#![doc(alias = "not working!")] //~ ERROR
+
+#[doc(alias = "shouldn't work!")] //~ ERROR
+pub struct Foo;

Diff for: src/test/ui/doc-alias-crate-level.stderr

@@ -1,8 +1,14 @@
 error: '\'' character isn't allowed in `#[doc(alias = "...")]`
-  --> $DIR/doc-alias-crate-level.rs:7:16
+  --> $DIR/doc-alias-crate-level.rs:9:15
    |
-LL | #![doc(alias = "shouldn't work!")]
-   |                ^^^^^^^^^^^^^^^^^
+LL | #[doc(alias = "shouldn't work!")]
+   |               ^^^^^^^^^^^^^^^^^
 
-error: aborting due to previous error
+error: `#![doc(alias = "...")]` isn't allowed as a crate level attribute
+  --> $DIR/doc-alias-crate-level.rs:7:8
+   |
+LL | #![doc(alias = "not working!")]
+   |        ^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
 

Diff for: src/test/ui/doc_keyword.rs

@@ -0,0 +1,12 @@
+#![crate_type = "lib"]
+#![feature(doc_keyword)]
+
+#![doc(keyword = "hello")] //~ ERROR
+
+#[doc(keyword = "hell")] //~ ERROR
+mod foo {
+    fn hell() {}
+}
+
+#[doc(keyword = "hall")] //~ ERROR
+fn foo() {}

Diff for: src/test/ui/doc_keyword.stderr

@@ -0,0 +1,20 @@
+error: `#[doc(keyword = "...")]` can only be used on empty modules
+  --> $DIR/doc_keyword.rs:6:7
+   |
+LL | #[doc(keyword = "hell")]
+   |       ^^^^^^^^^^^^^^^^
+
+error: `#[doc(keyword = "...")]` can only be used on modules
+  --> $DIR/doc_keyword.rs:11:7
+   |
+LL | #[doc(keyword = "hall")]
+   |       ^^^^^^^^^^^^^^^^
+
+error: `#![doc(keyword = "...")]` isn't allowed as a crate level attribute
+  --> $DIR/doc_keyword.rs:4:8
+   |
+LL | #![doc(keyword = "hello")]
+   |        ^^^^^^^^^^^^^^^^^
+
+error: aborting due to 3 previous errors
+