Future proof us against upcoming changes to derives

CHANGELOG.md

@@ -17,6 +17,11 @@ for Rust libraries in [RFC #1105](https://github.com/rust-lang/rfcs/blob/master/
 
 [write-tuple-1-4-0]: docs.diesel.rs/diesel/serialize/trait.WriteTuple.html
 
+### Changed
+
+* Diesel's derives now require that `extern crate diesel;` be at your crate root
+  (e.g. `src/lib.rs` or `src/main.rs`)
+
 ## [1.3.2] - 2018-06-13
 
 ### Fixed

diesel/src/lib.rs

@@ -354,3 +354,7 @@ pub use query_builder::debug_query;
 pub use query_builder::functions::{delete, insert_into, insert_or_ignore_into, replace_into,
                                    select, sql_query, update};
 pub use result::Error::NotFound;
+
+pub(crate) mod diesel {
+    pub use super::*;
+}

diesel/src/macros/mod.rs

@@ -1042,15 +1042,6 @@ macro_rules! allow_tables_to_appear_in_same_query {
     () => {};
 }
 
-#[macro_export]
-#[doc(hidden)]
-/// Used by `diesel_derives`, which can't access `$crate`
-macro_rules! __diesel_use_everything {
-    () => {
-        pub use $crate::*;
-    };
-}
-
 /// Gets the value out of an option, or returns an error.
 ///
 /// This is used by `FromSql` implementations.

diesel_derives/src/as_changeset.rs

@@ -61,8 +61,8 @@ pub fn derive(item: syn::DeriveInput) -> Result<quote::Tokens, Diagnostic> {
     Ok(wrap_in_dummy_mod(
         model.dummy_mod_name("as_changeset"),
         quote!(
-            use self::diesel::query_builder::AsChangeset;
-            use self::diesel::prelude::*;
+            use diesel::query_builder::AsChangeset;
+            use diesel::prelude::*;
 
             impl #impl_generics AsChangeset for &'update #struct_name #ty_generics
             #where_clause

diesel_derives/src/as_expression.rs

@@ -108,10 +108,10 @@ pub fn derive(item: syn::DeriveInput) -> Result<quote::Tokens, Diagnostic> {
         Ok(wrap_in_dummy_mod(
             dummy_mod.into(),
             quote! {
-                use self::diesel::expression::AsExpression;
-                use self::diesel::expression::bound::Bound;
-                use self::diesel::sql_types::Nullable;
-                use self::diesel::serialize::{self, ToSql, Output};
+                use diesel::expression::AsExpression;
+                use diesel::expression::bound::Bound;
+                use diesel::sql_types::Nullable;
+                use diesel::serialize::{self, ToSql, Output};
 
                 #(#tokens)*
             },

diesel_derives/src/diesel_numeric_ops.rs

@@ -23,10 +23,10 @@ pub fn derive(mut item: syn::DeriveInput) -> Result<quote::Tokens, Diagnostic> {
     Ok(wrap_in_dummy_mod(
         dummy_name.to_lowercase().into(),
         quote! {
-            use self::diesel::expression::{ops, Expression, AsExpression};
-            use self::diesel::sql_types::ops::{Add, Sub, Mul, Div};
+            use diesel::expression::{ops, Expression, AsExpression};
+            use diesel::sql_types::ops::{Add, Sub, Mul, Div};
 
-            impl #impl_generics self::std::ops::Add<__Rhs> for #struct_name #ty_generics
+            impl #impl_generics ::std::ops::Add<__Rhs> for #struct_name #ty_generics
             #where_clause
                 <Self as Expression>::SqlType: Add,
                 __Rhs: AsExpression<<<Self as Expression>::SqlType as Add>::Rhs>,
@@ -38,7 +38,7 @@ pub fn derive(mut item: syn::DeriveInput) -> Result<quote::Tokens, Diagnostic> {
                 }
             }
 
-            impl #impl_generics self::std::ops::Sub<__Rhs> for #struct_name #ty_generics
+            impl #impl_generics ::std::ops::Sub<__Rhs> for #struct_name #ty_generics
             #where_clause
                 <Self as Expression>::SqlType: Sub,
                 __Rhs: AsExpression<<<Self as Expression>::SqlType as Sub>::Rhs>,
@@ -50,7 +50,7 @@ pub fn derive(mut item: syn::DeriveInput) -> Result<quote::Tokens, Diagnostic> {
                 }
             }
 
-            impl #impl_generics self::std::ops::Mul<__Rhs> for #struct_name #ty_generics
+            impl #impl_generics ::std::ops::Mul<__Rhs> for #struct_name #ty_generics
             #where_clause
                 <Self as Expression>::SqlType: Mul,
                 __Rhs: AsExpression<<<Self as Expression>::SqlType as Mul>::Rhs>,
@@ -62,7 +62,7 @@ pub fn derive(mut item: syn::DeriveInput) -> Result<quote::Tokens, Diagnostic> {
                 }
             }
 
-            impl #impl_generics self::std::ops::Div<__Rhs> for #struct_name #ty_generics
+            impl #impl_generics ::std::ops::Div<__Rhs> for #struct_name #ty_generics
             #where_clause
                 <Self as Expression>::SqlType: Div,
                 __Rhs: AsExpression<<<Self as Expression>::SqlType as Div>::Rhs>,

diesel_derives/src/from_sql_row.rs

@@ -31,7 +31,7 @@ pub fn derive(mut item: syn::DeriveInput) -> Result<Tokens, Diagnostic> {
     Ok(wrap_in_dummy_mod(
         dummy_mod,
         quote! {
-            use self::diesel::deserialize::{self, FromSql, FromSqlRow, Queryable};
+            use diesel::deserialize::{self, FromSql, FromSqlRow, Queryable};
 
             impl #impl_generics FromSqlRow<__ST, __DB> for #struct_ty
             #where_clause

diesel_derives/src/identifiable.rs

@@ -24,7 +24,7 @@ pub fn derive(item: syn::DeriveInput) -> Result<quote::Tokens, Diagnostic> {
     Ok(wrap_in_dummy_mod(
         model.dummy_mod_name("identifiable"),
         quote! {
-            use self::diesel::associations::{HasTable, Identifiable};
+            use diesel::associations::{HasTable, Identifiable};
 
             impl #impl_generics HasTable for #struct_name #ty_generics
             #where_clause

diesel_derives/src/insertable.rs

@@ -51,9 +51,9 @@ pub fn derive(item: syn::DeriveInput) -> Result<quote::Tokens, Diagnostic> {
     Ok(wrap_in_dummy_mod(
         model.dummy_mod_name("insertable"),
         quote! {
-            use self::diesel::insertable::Insertable;
-            use self::diesel::query_builder::UndecoratedInsertRecord;
-            use self::diesel::prelude::*;
+            use diesel::insertable::Insertable;
+            use diesel::query_builder::UndecoratedInsertRecord;
+            use diesel::prelude::*;
 
             impl #impl_generics Insertable<#table_name::table> for #struct_name #ty_generics
                 #where_clause

diesel_derives/src/query_id.rs

@@ -24,7 +24,7 @@ pub fn derive(mut item: syn::DeriveInput) -> Result<quote::Tokens, Diagnostic> {
     Ok(wrap_in_dummy_mod(
         dummy_mod.into(),
         quote! {
-            use self::diesel::query_builder::QueryId;
+            use diesel::query_builder::QueryId;
 
             #[allow(non_camel_case_types)]
             impl #impl_generics QueryId for #struct_name #ty_generics

diesel_derives/src/queryable.rs

@@ -32,7 +32,7 @@ pub fn derive(item: syn::DeriveInput) -> Result<quote::Tokens, Diagnostic> {
     Ok(wrap_in_dummy_mod(
         model.dummy_mod_name("queryable"),
         quote! {
-            use self::diesel::Queryable;
+            use diesel::Queryable;
 
             impl #impl_generics Queryable<__ST, __DB> for #struct_name #ty_generics
             #where_clause

diesel_derives/src/queryable_by_name.rs

@@ -37,8 +37,8 @@ pub fn derive(item: syn::DeriveInput) -> Result<quote::Tokens, Diagnostic> {
     Ok(wrap_in_dummy_mod(
         model.dummy_mod_name("queryable_by_name"),
         quote! {
-            use self::diesel::deserialize::{self, QueryableByName};
-            use self::diesel::row::NamedRow;
+            use diesel::deserialize::{self, QueryableByName};
+            use diesel::row::NamedRow;
 
             impl #impl_generics QueryableByName<__DB>
                 for #struct_name #ty_generics

diesel_derives/src/sql_type.rs

@@ -121,7 +121,7 @@ fn pg_tokens(item: &syn::DeriveInput) -> Option<quote::Tokens> {
             };
 
             Some(quote! {
-                use self::diesel::pg::{PgMetadataLookup, PgTypeMetadata};
+                use diesel::pg::{PgMetadataLookup, PgTypeMetadata};
 
                 impl #impl_generics diesel::sql_types::HasSqlType<#struct_name #ty_generics>
                     for diesel::pg::Pg

diesel_derives/src/util.rs

@@ -6,17 +6,13 @@ pub use diagnostic_shim::*;
 use meta::*;
 
 pub fn wrap_in_dummy_mod(const_name: Ident, item: Tokens) -> Tokens {
-    let call_site = root_span(Span::call_site());
-    let use_everything = quote_spanned!(call_site=> __diesel_use_everything!());
     quote! {
-        #[allow(non_snake_case, unused_extern_crates)]
+        #[allow(non_snake_case, unused_extern_crates, unused_imports)]
         mod #const_name {
             // https://github.com/rust-lang/rust/issues/47314
             extern crate std;
+            use diesel;
 
-            mod diesel {
-                #use_everything;
-            }
             #item
         }
     }
@@ -78,16 +74,3 @@ pub fn fix_span(maybe_bad_span: Span, fallback: Span) -> Span {
         maybe_bad_span
     }
 }
-
-#[cfg(not(feature = "nightly"))]
-fn root_span(span: Span) -> Span {
-    span
-}
-
-#[cfg(feature = "nightly")]
-/// There's an issue with the resolution of `__diesel_use_everything` if the
-/// derive itself was generated from within a macro. This is a shitty workaround
-/// until we figure out the expected behavior.
-fn root_span(span: Span) -> Span {
-    span.unstable().source().into()
-}