Update missing-doc test to explicitly check errors

This way we can be sure the correct error is displayed for the
respective code type.

src/test/compile-fail/lint-missing-doc.rs

@@ -17,15 +17,15 @@
 #![doc="More garbage"]
 
 type Typedef = String;
-pub type PubTypedef = String; //~ ERROR: missing documentation
+pub type PubTypedef = String; //~ ERROR: missing documentation for a type alias
 
 struct Foo {
     a: isize,
     b: isize,
 }
 
-pub struct PubFoo { //~ ERROR: missing documentation
-    pub a: isize,      //~ ERROR: missing documentation
+pub struct PubFoo { //~ ERROR: missing documentation for a struct
+    pub a: isize,      //~ ERROR: missing documentation for a struct field
     b: isize,
 }
 
@@ -36,11 +36,11 @@ pub struct PubFoo2 {
 }
 
 mod module_no_dox {}
-pub mod pub_module_no_dox {} //~ ERROR: missing documentation
+pub mod pub_module_no_dox {} //~ ERROR: missing documentation for a module
 
 /// dox
 pub fn foo() {}
-pub fn foo2() {} //~ ERROR: missing documentation
+pub fn foo2() {} //~ ERROR: missing documentation for a function
 fn foo3() {}
 #[allow(missing_docs)] pub fn foo4() {}
 
@@ -58,9 +58,9 @@ trait B {
     fn foo_with_impl(&self) {}
 }
 
-pub trait C { //~ ERROR: missing documentation
-    fn foo(&self); //~ ERROR: missing documentation
-    fn foo_with_impl(&self) {} //~ ERROR: missing documentation
+pub trait C { //~ ERROR: missing documentation for a trait
+    fn foo(&self); //~ ERROR: missing documentation for a type method
+    fn foo_with_impl(&self) {} //~ ERROR: missing documentation for a method
 }
 
 #[allow(missing_docs)]
@@ -70,8 +70,8 @@ pub trait D {
 
 /// dox
 pub trait E {
-    type AssociatedType; //~ ERROR: missing documentation
-    type AssociatedTypeDef = Self; //~ ERROR: missing documentation
+    type AssociatedType; //~ ERROR: missing documentation for an associated type
+    type AssociatedTypeDef = Self; //~ ERROR: missing documentation for an associated type
 
     /// dox
     type DocumentedType;
@@ -87,7 +87,7 @@ impl Foo {
 }
 
 impl PubFoo {
-    pub fn foo() {} //~ ERROR: missing documentation
+    pub fn foo() {} //~ ERROR: missing documentation for a method
     /// dox
     pub fn foo1() {}
     fn foo2() {}
@@ -124,9 +124,9 @@ enum Baz {
     BarB
 }
 
-pub enum PubBaz { //~ ERROR: missing documentation
-    PubBazA { //~ ERROR: missing documentation
-        a: isize, //~ ERROR: missing documentation
+pub enum PubBaz { //~ ERROR: missing documentation for an enum
+    PubBazA { //~ ERROR: missing documentation for a variant
+        a: isize, //~ ERROR: missing documentation for a struct field
     },
 }
 
@@ -152,14 +152,14 @@ pub fn baz() {}
 mod internal_impl {
     /// dox
     pub fn documented() {}
-    pub fn undocumented1() {} //~ ERROR: missing documentation
-    pub fn undocumented2() {} //~ ERROR: missing documentation
+    pub fn undocumented1() {} //~ ERROR: missing documentation for a function
+    pub fn undocumented2() {} //~ ERROR: missing documentation for a function
     fn undocumented3() {}
     /// dox
     pub mod globbed {
         /// dox
         pub fn also_documented() {}
-        pub fn also_undocumented1() {} //~ ERROR: missing documentation
+        pub fn also_undocumented1() {} //~ ERROR: missing documentation for a function
         fn also_undocumented2() {}
     }
 }