Improve the warning messages for deprecated attributes

diesel_compile_tests/tests/fail/derive_deprecated/deprecated_belongs_to.stderr

@@ -1,116 +1,80 @@
-warning: #[belongs_to] attribute form is deprecated
-  = help: use `#[diesel(belongs_to(User, foreign_key = mykey))]` format instead
-
 error: unexpected end of input, expected parentheses
   --> $DIR/deprecated_belongs_to.rs:29:3
    |
 29 | #[belongs_to]
    |   ^^^^^^^^^^
 
-warning: #[belongs_to] attribute form is deprecated
-  = help: use `#[diesel(belongs_to(User, foreign_key = mykey))]` format instead
-
 error: expected parentheses
   --> $DIR/deprecated_belongs_to.rs:36:14
    |
 36 | #[belongs_to = Bar]
    |              ^
 
-warning: #[belongs_to] attribute form is deprecated
-  = help: use `#[diesel(belongs_to(User, foreign_key = mykey))]` format instead
-
 error: unexpected end of input, expected identifier
   --> $DIR/deprecated_belongs_to.rs:43:13
    |
 43 | #[belongs_to()]
    |             ^^
 
-warning: #[belongs_to] attribute form is deprecated
-  = help: use `#[diesel(belongs_to(User, foreign_key = mykey))]` format instead
-
 error: expected identifier
   --> $DIR/deprecated_belongs_to.rs:50:14
    |
 50 | #[belongs_to("what")]
    |              ^^^^^^
 
-warning: #[belongs_to] attribute form is deprecated
-  = help: use `#[diesel(belongs_to(User, foreign_key = mykey))]` format instead
-
 error: unexpected end of input, expected `=`
   --> $DIR/deprecated_belongs_to.rs:57:14
    |
 57 | #[belongs_to(parent)]
    |              ^^^^^^
 
-warning: #[belongs_to] attribute form is deprecated
-  = help: use `#[diesel(belongs_to(User, foreign_key = mykey))]` format instead
-
 error: expected `=`
   --> $DIR/deprecated_belongs_to.rs:64:20
    |
 64 | #[belongs_to(parent())]
    |                    ^^
 
-warning: #[belongs_to] attribute form is deprecated
-  = help: use `#[diesel(belongs_to(User, foreign_key = mykey))]` format instead
-
 error: expected string literal
   --> $DIR/deprecated_belongs_to.rs:71:23
    |
 71 | #[belongs_to(parent = 1)]
    |                       ^
 
-warning: #[belongs_to] attribute form is deprecated
-  = help: use `#[diesel(belongs_to(User, foreign_key = mykey))]` format instead
-
 error: expected identifier
   --> $DIR/deprecated_belongs_to.rs:78:23
    |
 78 | #[belongs_to(parent = "1")]
    |                       ^^^
 
 warning: #[belongs_to] attribute form is deprecated
-  = help: use `#[diesel(belongs_to(User, foreign_key = mykey))]` format instead
-
-warning: #[belongs_to] attribute form is deprecated
-  = help: use `#[diesel(belongs_to(User, foreign_key = mykey))]` format instead
+  = help: use `#[diesel(belongs_to(Bar))]` instead
 
 error: expected `foreign_key`
   --> $DIR/deprecated_belongs_to.rs:92:19
    |
 92 | #[belongs_to(Bar, what)]
    |                   ^^^^
 
-warning: #[belongs_to] attribute form is deprecated
-  = help: use `#[diesel(belongs_to(User, foreign_key = mykey))]` format instead
-
 error: unexpected end of input, expected `=`
   --> $DIR/deprecated_belongs_to.rs:99:19
    |
 99 | #[belongs_to(Bar, foreign_key)]
    |                   ^^^^^^^^^^^
 
-warning: #[belongs_to] attribute form is deprecated
-  = help: use `#[diesel(belongs_to(User, foreign_key = mykey))]` format instead
-
 error: expected string literal
    --> $DIR/deprecated_belongs_to.rs:106:33
     |
 106 | #[belongs_to(Bar, foreign_key = 1)]
     |                                 ^
 
-warning: #[belongs_to] attribute form is deprecated
-  = help: use `#[diesel(belongs_to(User, foreign_key = mykey))]` format instead
-
 error: expected identifier
    --> $DIR/deprecated_belongs_to.rs:113:33
     |
 113 | #[belongs_to(Bar, foreign_key = "1")]
     |                                 ^^^
 
 warning: #[belongs_to] attribute form is deprecated
-  = help: use `#[diesel(belongs_to(User, foreign_key = mykey))]` format instead
+  = help: use `#[diesel(belongs_to(Baz, foreign_key = bar_id))]` instead
 
 error: unexpected token: `Bar`
   --> $DIR/deprecated_belongs_to.rs:36:16

diesel_compile_tests/tests/fail/derive_deprecated/deprecated_changeset_options.stderr

@@ -1,45 +1,30 @@
 warning: #[changeset_options] attribute form is deprecated
-  = help: use `#[diesel(treat_none_as_null = true)]` format instead
-
-warning: #[changeset_options] attribute form is deprecated
-  = help: use `#[diesel(treat_none_as_null = true)]` format instead
+  = help: use `#[diesel(treat_none_as_null = true)]` instead
 
 error: unexpected end of input, expected parentheses
   --> $DIR/deprecated_changeset_options.rs:21:3
    |
 21 | #[changeset_options]
    |   ^^^^^^^^^^^^^^^^^
 
-warning: #[changeset_options] attribute form is deprecated
-  = help: use `#[diesel(treat_none_as_null = true)]` format instead
-
 error: unexpected end of input, expected identifier
   --> $DIR/deprecated_changeset_options.rs:29:20
    |
 29 | #[changeset_options()]
    |                    ^^
 
-warning: #[changeset_options] attribute form is deprecated
-  = help: use `#[diesel(treat_none_as_null = true)]` format instead
-
 error: expected `treat_none_as_null`
   --> $DIR/deprecated_changeset_options.rs:37:21
    |
 37 | #[changeset_options(what)]
    |                     ^^^^
 
-warning: #[changeset_options] attribute form is deprecated
-  = help: use `#[diesel(treat_none_as_null = true)]` format instead
-
 error: unexpected end of input, expected `=`
   --> $DIR/deprecated_changeset_options.rs:45:21
    |
 45 | #[changeset_options(treat_none_as_null)]
    |                     ^^^^^^^^^^^^^^^^^^
 
-warning: #[changeset_options] attribute form is deprecated
-  = help: use `#[diesel(treat_none_as_null = true)]` format instead
-
 error: expected boolean literal
   --> $DIR/deprecated_changeset_options.rs:53:42
    |

diesel_compile_tests/tests/fail/derive_deprecated/deprecated_column_name.stderr

@@ -1,40 +1,31 @@
 warning: #[column_name] attribute form is deprecated
-  = help: use `#[diesel(column_name = name)]` format instead
+  = help: use `#[diesel(column_name = name)]` instead
 
 warning: #[column_name] attribute form is deprecated
-  = help: use `#[diesel(column_name = name)]` format instead
-
-warning: #[column_name] attribute form is deprecated
-  = help: use `#[diesel(column_name = name)]` format instead
+  = help: use `#[diesel(column_name = name)]` instead
 
 error: unexpected end of input, expected `=`
   --> $DIR/deprecated_column_name.rs:24:7
    |
 24 |     #[column_name]
    |       ^^^^^^^^^^^
 
-warning: #[column_name] attribute form is deprecated
-  = help: use `#[diesel(column_name = name)]` format instead
-
 error: expected `=`
   --> $DIR/deprecated_column_name.rs:31:18
    |
 31 |     #[column_name()]
    |                  ^^
 
-warning: #[column_name] attribute form is deprecated
-  = help: use `#[diesel(column_name = name)]` format instead
-
 error: expected string literal
   --> $DIR/deprecated_column_name.rs:38:21
    |
 38 |     #[column_name = 1]
    |                     ^
 
 warning: #[column_name] attribute form is deprecated
-  = help: use `#[diesel(column_name = name)]` format instead
+  = help: use `#[diesel(column_name = 1)]` instead
 
-error: expected identifier
+error: expected string literal
   --> $DIR/deprecated_column_name.rs:45:21
    |
 45 |     #[column_name = "1"]

diesel_compile_tests/tests/fail/derive_deprecated/deprecated_mysql_type.stderr

@@ -1,32 +1,23 @@
-warning: #[mysql_type] attribute form is deprecated
-  = help: use `#[diesel(mysql_type(name = "TypeName"))]` format instead
-
 error: unexpected end of input, expected `=`
  --> $DIR/deprecated_mysql_type.rs:6:3
   |
 6 | #[mysql_type]
   |   ^^^^^^^^^^
 
-warning: #[mysql_type] attribute form is deprecated
-  = help: use `#[diesel(mysql_type(name = "TypeName"))]` format instead
-
 error: expected `=`
   --> $DIR/deprecated_mysql_type.rs:10:13
    |
 10 | #[mysql_type()]
    |             ^^
 
-warning: #[mysql_type] attribute form is deprecated
-  = help: use `#[diesel(mysql_type(name = "TypeName"))]` format instead
-
 error: expected string literal
   --> $DIR/deprecated_mysql_type.rs:14:16
    |
 14 | #[mysql_type = 1]
    |                ^
 
 warning: #[mysql_type] attribute form is deprecated
-  = help: use `#[diesel(mysql_type(name = "TypeName"))]` format instead
+  = help: use `#[diesel(mysql_type(name = "foo"))]` instead
 
 error[E0599]: no variant or associated item named `foo` found for enum `MysqlType` in the current scope
   --> $DIR/deprecated_mysql_type.rs:17:10

diesel_compile_tests/tests/fail/derive_deprecated/deprecated_postgres_type.stderr

@@ -1,107 +1,71 @@
-warning: #[postgres] attribute form is deprecated
-  = help: use `#[diesel(postgres_type(name = "TypeName", schema = "public"))]` format instead
-
 error: unexpected end of input, expected parentheses
  --> $DIR/deprecated_postgres_type.rs:6:3
   |
 6 | #[postgres]
   |   ^^^^^^^^
 
-warning: #[postgres] attribute form is deprecated
-  = help: use `#[diesel(postgres_type(name = "TypeName", schema = "public"))]` format instead
-
 error: expected `oid` and `array_oid` attribute or `name` attribute
   --> $DIR/deprecated_postgres_type.rs:10:11
    |
 10 | #[postgres()]
    |           ^^
 
-warning: #[postgres] attribute form is deprecated
-  = help: use `#[diesel(postgres_type(name = "TypeName", schema = "public"))]` format instead
-
 error: expected parentheses
   --> $DIR/deprecated_postgres_type.rs:14:12
    |
 14 | #[postgres = "foo"]
    |            ^
 
-warning: #[postgres] attribute form is deprecated
-  = help: use `#[diesel(postgres_type(name = "TypeName", schema = "public"))]` format instead
-
 error: unexpected end of input, expected `=`
   --> $DIR/deprecated_postgres_type.rs:18:12
    |
 18 | #[postgres(type_name)]
    |            ^^^^^^^^^
 
-warning: #[postgres] attribute form is deprecated
-  = help: use `#[diesel(postgres_type(name = "TypeName", schema = "public"))]` format instead
-
 error: expected `=`
   --> $DIR/deprecated_postgres_type.rs:22:21
    |
 22 | #[postgres(type_name())]
    |                     ^^
 
-warning: #[postgres] attribute form is deprecated
-  = help: use `#[diesel(postgres_type(name = "TypeName", schema = "public"))]` format instead
-
 error: expected string literal
   --> $DIR/deprecated_postgres_type.rs:26:24
    |
 26 | #[postgres(type_name = 1)]
    |                        ^
 
-warning: #[postgres] attribute form is deprecated
-  = help: use `#[diesel(postgres_type(name = "TypeName", schema = "public"))]` format instead
-
 error: unexpected `oid` when `name` is present
   --> $DIR/deprecated_postgres_type.rs:30:37
    |
 30 | #[postgres(type_name = "foo", oid = "2", array_oid = "3")]
    |                                     ^^^
 
-warning: #[postgres] attribute form is deprecated
-  = help: use `#[diesel(postgres_type(name = "TypeName", schema = "public"))]` format instead
-
 error: unexpected `array_oid` when `name` is present
   --> $DIR/deprecated_postgres_type.rs:34:43
    |
 34 | #[postgres(type_name = "foo", array_oid = "3")]
    |                                           ^^^
 
-warning: #[postgres] attribute form is deprecated
-  = help: use `#[diesel(postgres_type(name = "TypeName", schema = "public"))]` format instead
-
 error: expected `oid` and `array_oid` attribute or `name` attribute
   --> $DIR/deprecated_postgres_type.rs:38:11
    |
 38 | #[postgres(oid = "2")]
    |           ^^^^^^^^^^^
 
-warning: #[postgres] attribute form is deprecated
-  = help: use `#[diesel(postgres_type(name = "TypeName", schema = "public"))]` format instead
-
 error: expected string literal
   --> $DIR/deprecated_postgres_type.rs:42:18
    |
 42 | #[postgres(oid = 1, array_oid = "1")]
    |                  ^
 
-warning: #[postgres] attribute form is deprecated
-  = help: use `#[diesel(postgres_type(name = "TypeName", schema = "public"))]` format instead
-
 error: expected string literal
   --> $DIR/deprecated_postgres_type.rs:46:35
    |
 46 | #[postgres(oid = "1", array_oid = 1)]
    |                                   ^
 
 warning: #[postgres] attribute form is deprecated
-  = help: use `#[diesel(postgres_type(name = "TypeName", schema = "public"))]` format instead
-
-warning: #[postgres] attribute form is deprecated
-  = help: use `#[diesel(postgres_type(name = "TypeName", schema = "public"))]` format instead
+  = help: use `#[diesel(postgres_type(oid = 1, array_oid = 1))]` instead
 
 error: unknown attribute
   --> $DIR/deprecated_postgres_type.rs:54:12

diesel_compile_tests/tests/fail/derive_deprecated/deprecated_primary_key.stderr

@@ -1,41 +1,29 @@
-warning: #[primary_key] attribute form is deprecated
-  = help: use `#[diesel(primary_key(id1, id2))]` format instead
-
 error: expected `,`
   --> $DIR/deprecated_primary_key.rs:12:23
    |
 12 | #[primary_key(id, bar = "baz")]
    |                       ^
 
-warning: #[primary_key] attribute form is deprecated
-  = help: use `#[diesel(primary_key(id1, id2))]` format instead
-
 error: expected `,`
   --> $DIR/deprecated_primary_key.rs:19:22
    |
 19 | #[primary_key(id, qux(id))]
    |                      ^^^^
 
-warning: #[primary_key] attribute form is deprecated
-  = help: use `#[diesel(primary_key(id1, id2))]` format instead
-
 error: unexpected end of input, expected parentheses
   --> $DIR/deprecated_primary_key.rs:26:3
    |
 26 | #[primary_key]
    |   ^^^^^^^^^^^
 
-warning: #[primary_key] attribute form is deprecated
-  = help: use `#[diesel(primary_key(id1, id2))]` format instead
-
 error: expected parentheses
   --> $DIR/deprecated_primary_key.rs:33:15
    |
 33 | #[primary_key = id]
    |               ^
 
 warning: #[primary_key] attribute form is deprecated
-  = help: use `#[diesel(primary_key(id1, id2))]` format instead
+  = help: use `#[diesel(primary_key(id, name))]` instead
 
 error: Deriving `AsChangeset` on a structure that only contains primary keys isn't supported.