Add error code to inner doc comment attribute error

2 files changed, 32 insertions, 0 deletions

diff --git a/src/librustc_error_codes/error_codes.rs b/src/librustc_error_codes/error_codes.rs
index bc04809eaa1..9f4b5fd85fd 100644
--- a/src/librustc_error_codes/error_codes.rs
+++ b/src/librustc_error_codes/error_codes.rs
@@ -432,6 +432,7 @@ E0749: include_str!("./error_codes/E0749.md"),
 E0750: include_str!("./error_codes/E0750.md"),
 E0751: include_str!("./error_codes/E0751.md"),
 E0752: include_str!("./error_codes/E0752.md"),
+E0753: include_str!("./error_codes/E0753.md"),
 ;
 //  E0006, // merged with E0005
 //  E0008, // cannot bind by-move into a pattern guard
diff --git a/src/librustc_error_codes/error_codes/E0753.md b/src/librustc_error_codes/error_codes/E0753.md
new file mode 100644
index 00000000000..a69da964aee
--- /dev/null
+++ b/src/librustc_error_codes/error_codes/E0753.md
@@ -0,0 +1,31 @@
+An inner doc comment was used in an invalid context.
+
+Erroneous code example:
+
+```compile_fail,E0753
+fn foo() {}
+//! foo
+// ^ error!
+fn main() {}
+```
+
+Inner document can only be used before items. For example:
+
+```
+//! A working comment applied to the module!
+fn foo() {
+    //! Another working comment!
+}
+fn main() {}
+```
+
+In case you want to document the item following the doc comment, you might want
+to use outer doc comment:
+
+```
+/// I am an outer doc comment
+#[doc = "I am also an outer doc comment!"]
+fn foo() {
+    // ...
+}
+```