Clean up error messages

Author: sfackler

postgres-derive-codegen/src/enums.rs

@@ -12,7 +12,7 @@ pub fn get_variants(ctx: &mut ExtCtxt, trait_: &str, def: &EnumDef) -> Vec<(Iden
             VariantData::Unit(_) => {}
             _ => {
                 ctx.span_err(variant.span,
-                             &format!("#[derive({})] can only be applied to C-like enums", trait_));
+                             &format!("#[derive({})] does not support non-C-like enums", trait_));
                 continue;
             }
         }

postgres-derive-codegen/src/fromsql.rs

@@ -17,8 +17,8 @@ pub fn expand(ctx: &mut ExtCtxt,
     let item = match *annotatable {
         Annotatable::Item(ref item) => item,
         _ => {
-            ctx.span_err(span,
-                         "#[derive(FromSql)] can only be applied to tuple structs and enums");
+            ctx.span_err(span, "#[derive(FromSql)] can only be applied to structs, single field \
+                                tuple structs, and enums");
             return;
         }
     };
@@ -34,8 +34,8 @@ pub fn expand(ctx: &mut ExtCtxt,
         }
         ItemKind::Struct(VariantData::Tuple(ref fields, _), _) => {
             if fields.len() != 1 {
-                ctx.span_err(span,
-                             "#[derive(FromSql)] can only be applied to one field tuple structs");
+                ctx.span_err(span, "#[derive(FromSql)] can only be applied to structs, single \
+                                    field tuple structs, and enums");
                 return;
             }
             let inner = &fields[0].ty;
@@ -56,8 +56,8 @@ pub fn expand(ctx: &mut ExtCtxt,
              composite_from_sql_body(ctx, span, item.ident, &*fields))
         }
         _ => {
-            ctx.span_err(span,
-                         "#[derive(FromSql)] can only be applied to tuple structs and enums");
+            ctx.span_err(span, "#[derive(FromSql)] can only be applied to structs, single field \
+                                tuple structs, and enums");
             return;
         }
     };

postgres-derive-codegen/src/tosql.rs

@@ -17,8 +17,8 @@ pub fn expand(ctx: &mut ExtCtxt,
     let item = match *annotatable {
         Annotatable::Item(ref item) => item,
         _ => {
-            ctx.span_err(span,
-                         "#[derive(ToSql)] can only be applied to tuple structs and enums");
+            ctx.span_err(span, "#[derive(ToSql)] can only be applied to structs, single field \
+                                tuple structs, and enums");
             return;
         }
     };
@@ -34,8 +34,8 @@ pub fn expand(ctx: &mut ExtCtxt,
         }
         ItemKind::Struct(VariantData::Tuple(ref fields, _), _) => {
             if fields.len() != 1 {
-                ctx.span_err(span,
-                             "#[derive(ToSql)] can only be applied to one field tuple structs");
+                ctx.span_err(span, "#[derive(ToSql)] can only be applied to structs, single field \
+                                    tuple structs, and enums");
                 return;
             }
             let inner = &fields[0].ty;
@@ -56,8 +56,8 @@ pub fn expand(ctx: &mut ExtCtxt,
              composite_to_sql_body(ctx, span, &*fields))
         }
         _ => {
-            ctx.span_err(span,
-                         "#[derive(ToSql)] can only be applied to tuple structs and enums");
+            ctx.span_err(span, "#[derive(ToSql)] can only be applied to structs, single field \
+                                tuple structs, and enums");
             return;
         }
     };

postgres-derive-macros/tests/compile-fail/big-tuple-struct.rs

@@ -5,10 +5,10 @@ macro_rules! to_sql_checked {
     () => ()
 }
 
-#[derive(ToSql)] //~ ERROR #[derive(ToSql)] can only be applied to one field tuple structs
+#[derive(ToSql)] //~ ERROR #[derive(ToSql)] can only be applied to structs, single field tuple structs, and enums
 struct Foo(i32, i32);
 
-#[derive(FromSql)] //~ ERROR #[derive(FromSql)] can only be applied to one field tuple structs
+#[derive(FromSql)] //~ ERROR #[derive(FromSql)] can only be applied to structs, single field tuple structs, and enums
 struct Bar(i32, i32);
 
 fn main() {}

postgres-derive-macros/tests/compile-fail/complex-enum.rs

@@ -7,14 +7,14 @@ macro_rules! to_sql_checked {
 
 #[derive(ToSql)]
 enum Foo {
-    Bar(i32), //~ ERROR #[derive(ToSql)] can only be applied to C-like enums
-    Baz { b: i32 }, //~ ERROR #[derive(ToSql)] can only be applied to C-like enums
+    Bar(i32), //~ ERROR #[derive(ToSql)] does not support non-C-like enums
+    Baz { b: i32 }, //~ ERROR #[derive(ToSql)] does not support non-C-like enums
 }
 
 #[derive(FromSql)]
 enum Foo {
-    Bar(i32), //~ ERROR #[derive(FromSql)] can only be applied to C-like enums
-    Baz { b: i32 }, //~ ERROR #[derive(FromSql)] can only be applied to C-like enums
+    Bar(i32), //~ ERROR #[derive(FromSql)] does not support non-C-like enums
+    Baz { b: i32 }, //~ ERROR #[derive(FromSql)] does not support non-C-like enums
 }
 
 fn main() {}