Fix span in proc macro

diesel_compile_tests/tests/fail/derive/bad_insertable.stderr

@@ -79,6 +79,9 @@ error[E0277]: the trait bound `i32: diesel::Expression` is not satisfied
 error[E0277]: the trait bound `std::string::String: diesel::Expression` is not satisfied
   --> tests/fail/derive/bad_insertable.rs:12:5
    |
+10 | #[derive(Insertable)]
+   |          ---------- in this derive macro expansion
+11 | struct User {
 12 |     id: String,
    |     ^^ the trait `diesel::Expression` is not implemented for `std::string::String`, which is required by `std::string::String: AsExpression<diesel::sql_types::Integer>`
    |
@@ -93,10 +96,14 @@ error[E0277]: the trait bound `std::string::String: diesel::Expression` is not s
              (T0, T1, T2, T3, T4, T5, T6, T7)
            and $N others
    = note: required for `std::string::String` to implement `AsExpression<diesel::sql_types::Integer>`
+   = note: this error originates in the derive macro `Insertable` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the trait bound `i32: diesel::Expression` is not satisfied
   --> tests/fail/derive/bad_insertable.rs:13:5
    |
+10 | #[derive(Insertable)]
+   |          ---------- in this derive macro expansion
+...
 13 |     name: i32,
    |     ^^^^ the trait `diesel::Expression` is not implemented for `i32`, which is required by `i32: AsExpression<diesel::sql_types::Text>`
    |
@@ -111,10 +118,14 @@ error[E0277]: the trait bound `i32: diesel::Expression` is not satisfied
              (T0, T1, T2, T3, T4, T5, T6, T7)
            and $N others
    = note: required for `i32` to implement `AsExpression<diesel::sql_types::Text>`
+   = note: this error originates in the derive macro `Insertable` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the trait bound `std::string::String: diesel::Expression` is not satisfied
   --> tests/fail/derive/bad_insertable.rs:12:5
    |
+10 | #[derive(Insertable)]
+   |          ---------- in this derive macro expansion
+11 | struct User {
 12 |     id: String,
    |     ^^ the trait `diesel::Expression` is not implemented for `std::string::String`, which is required by `&'insert std::string::String: AsExpression<diesel::sql_types::Integer>`
    |
@@ -130,10 +141,14 @@ error[E0277]: the trait bound `std::string::String: diesel::Expression` is not s
            and $N others
    = note: required for `&'insert std::string::String` to implement `diesel::Expression`
    = note: required for `&'insert std::string::String` to implement `AsExpression<diesel::sql_types::Integer>`
+   = note: this error originates in the derive macro `Insertable` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the trait bound `i32: diesel::Expression` is not satisfied
   --> tests/fail/derive/bad_insertable.rs:13:5
    |
+10 | #[derive(Insertable)]
+   |          ---------- in this derive macro expansion
+...
 13 |     name: i32,
    |     ^^^^ the trait `diesel::Expression` is not implemented for `i32`, which is required by `&'insert i32: AsExpression<diesel::sql_types::Text>`
    |
@@ -149,3 +164,4 @@ error[E0277]: the trait bound `i32: diesel::Expression` is not satisfied
            and $N others
    = note: required for `&'insert i32` to implement `diesel::Expression`
    = note: required for `&'insert i32` to implement `AsExpression<diesel::sql_types::Text>`
+   = note: this error originates in the derive macro `Insertable` (in Nightly builds, run with -Z macro-backtrace for more info)

diesel_derives/src/as_changeset.rs

@@ -1,4 +1,4 @@
-use proc_macro2::TokenStream;
+use proc_macro2::{Span, TokenStream};
 use quote::{quote, quote_spanned};
 use syn::spanned::Spanned as _;
 use syn::{parse_quote, DeriveInput, Expr, Path, Result, Type};
@@ -27,7 +27,7 @@ pub fn derive(item: DeriveInput) -> Result<TokenStream> {
 
     if fields_for_update.is_empty() {
         return Err(syn::Error::new(
-            proc_macro2::Span::call_site(),
+            proc_macro2::Span::mixed_site(),
             "Deriving `AsChangeset` on a structure that only contains primary keys isn't supported.\n\
              help: If you want to change the primary key of a row, you should do so with `.set(table::id.eq(new_id))`.\n\
              note: `#[derive(AsChangeset)]` never changes the primary key of a row."
@@ -172,7 +172,7 @@ pub fn derive(item: DeriveInput) -> Result<TokenStream> {
 
 fn field_changeset_ty_embed(field: &Field, lifetime: Option<TokenStream>) -> TokenStream {
     let field_ty = &field.ty;
-    let span = field.span;
+    let span = Span::mixed_site().located_at(field.span);
     quote_spanned!(span=> #lifetime #field_ty)
 }
 

diesel_derives/src/as_expression.rs

@@ -12,7 +12,7 @@ pub fn derive(item: DeriveInput) -> Result<TokenStream> {
 
     if model.sql_types.is_empty() {
         return Err(syn::Error::new(
-            proc_macro2::Span::call_site(),
+            proc_macro2::Span::mixed_site(),
             "At least one `sql_type` is needed for deriving `AsExpression` on a structure.",
         ));
     }

diesel_derives/src/associations.rs

@@ -13,7 +13,7 @@ pub fn derive(item: DeriveInput) -> Result<TokenStream> {
 
     if model.belongs_to.is_empty() {
         return Err(syn::Error::new(
-            proc_macro2::Span::call_site(),
+            proc_macro2::Span::mixed_site(),
             "At least one `belongs_to` is needed for deriving `Associations` on a structure.",
         ));
     }

diesel_derives/src/field.rs

@@ -119,10 +119,10 @@ impl Field {
             None => FieldName::Unnamed(index.into()),
         };
 
-        let span = match name {
+        let span = Span::mixed_site().located_at(match name {
             FieldName::Named(ref ident) => ident.span(),
             FieldName::Unnamed(_) => ty.span(),
-        };
+        });
 
         Ok(Self {
             ty: ty.clone(),

diesel_derives/src/insertable.rs

@@ -2,7 +2,7 @@ use crate::attrs::AttributeSpanWrapper;
 use crate::field::Field;
 use crate::model::Model;
 use crate::util::{inner_of_option_ty, is_option_ty, wrap_in_dummy_mod};
-use proc_macro2::TokenStream;
+use proc_macro2::{Span, TokenStream};
 use quote::quote;
 use quote::quote_spanned;
 use syn::parse_quote;
@@ -177,7 +177,7 @@ fn derive_into_single_table(
 
 fn field_ty_embed(field: &Field, lifetime: Option<TokenStream>) -> TokenStream {
     let field_ty = &field.ty;
-    let span = field.span;
+    let span = Span::mixed_site().located_at(field.span);
     quote_spanned!(span=> #lifetime #field_ty)
 }
 
@@ -193,7 +193,7 @@ fn field_ty_serialize_as(
     treat_none_as_default_value: bool,
 ) -> Result<TokenStream> {
     let column_name = field.column_name()?.to_ident()?;
-    let span = field.span;
+    let span = Span::mixed_site().located_at(field.span);
     if treat_none_as_default_value {
         let inner_ty = inner_of_option_ty(ty);
 
@@ -242,7 +242,7 @@ fn field_ty(
     treat_none_as_default_value: bool,
 ) -> Result<TokenStream> {
     let column_name = field.column_name()?.to_ident()?;
-    let span = field.span;
+    let span = Span::mixed_site().located_at(field.span);
     if treat_none_as_default_value {
         let inner_ty = inner_of_option_ty(&field.ty);
 

diesel_derives/src/model.rs

@@ -52,15 +52,15 @@ impl Model {
             }) => Some(unnamed),
             _ if !allow_unit_structs => {
                 return Err(syn::Error::new(
-                    proc_macro2::Span::call_site(),
+                    proc_macro2::Span::mixed_site(),
                     "This derive can only be used on non-unit structs",
                 ));
             }
             _ => None,
         };
 
         let mut table_names = vec![];
-        let mut primary_key_names = vec![Ident::new("id", Span::call_site())];
+        let mut primary_key_names = vec![Ident::new("id", Span::mixed_site())];
         let mut treat_none_as_default_value = None;
         let mut treat_none_as_null = None;
         let mut belongs_to = vec![];

diesel_derives/src/queryable.rs

@@ -22,7 +22,7 @@ pub fn derive(item: DeriveInput) -> Result<TokenStream> {
     });
     let sql_type = &(0..model.fields().len())
         .map(|i| {
-            let i = Ident::new(&format!("__ST{i}"), Span::call_site());
+            let i = Ident::new(&format!("__ST{i}"), Span::mixed_site());
             quote!(#i)
         })
         .collect::<Vec<_>>();
@@ -33,7 +33,7 @@ pub fn derive(item: DeriveInput) -> Result<TokenStream> {
         .params
         .push(parse_quote!(__DB: diesel::backend::Backend));
     for id in 0..model.fields().len() {
-        let ident = Ident::new(&format!("__ST{id}"), Span::call_site());
+        let ident = Ident::new(&format!("__ST{id}"), Span::mixed_site());
         generics.params.push(parse_quote!(#ident));
     }
     {

diesel_derives/src/queryable_by_name.rs

@@ -1,4 +1,4 @@
-use proc_macro2::TokenStream;
+use proc_macro2::{Span, TokenStream};
 use quote::quote;
 use syn::{parse_quote, parse_quote_spanned, DeriveInput, Ident, LitStr, Result, Type};
 
@@ -45,7 +45,7 @@ pub fn derive(item: DeriveInput) -> Result<TokenStream> {
 
     for field in model.fields() {
         let where_clause = generics.where_clause.get_or_insert(parse_quote!(where));
-        let span = field.span;
+        let span = Span::mixed_site().located_at(field.span);
         let field_ty = field.ty_for_deserialize();
         if field.embed() {
             where_clause
@@ -63,7 +63,7 @@ pub fn derive(item: DeriveInput) -> Result<TokenStream> {
         let field_check_bound = model.fields().iter().filter(|f| !f.embed()).flat_map(|f| {
             backends.iter().map(move |b| {
                 let field_ty = f.ty_for_deserialize();
-                let span = f.span;
+                let span = Span::mixed_site().located_at(f.span);
                 let ty = sql_type(f, model).unwrap();
                 quote::quote_spanned! {span =>
                     #field_ty: diesel::deserialize::FromSqlRow<#ty, #b>

diesel_derives/src/selectable.rs

@@ -1,4 +1,4 @@
-use proc_macro2::TokenStream;
+use proc_macro2::{Span, TokenStream};
 use quote::quote;
 use syn::spanned::Spanned;
 use syn::DeriveInput;
@@ -51,7 +51,7 @@ pub fn derive(item: DeriveInput) -> Result<TokenStream> {
             .filter(|(f, _)| !f.embed())
             .flat_map(|(f, ty)| {
                 backends.iter().map(move |b| {
-                    let span = f.ty.span();
+                    let span = Span::mixed_site().located_at(f.ty.span());
                     let field_ty = to_field_ty_bound(f.ty_for_deserialize())?;
                     Ok(syn::parse_quote_spanned! {span =>
                         #field_ty: diesel::deserialize::FromSqlRow<diesel::dsl::SqlTypeOf<#ty>, #b>

diesel_derives/src/sql_type.rs

@@ -41,7 +41,7 @@ fn sqlite_tokens(item: &DeriveInput, model: &Model) -> Option<TokenStream> {
     model
         .sqlite_type
         .as_ref()
-        .map(|sqlite_type| Ident::new(&sqlite_type.name.value(), Span::call_site()))
+        .map(|sqlite_type| Ident::new(&sqlite_type.name.value(), Span::mixed_site()))
         .and_then(|ty| {
             if cfg!(not(feature = "sqlite")) {
                 return None;
@@ -67,7 +67,7 @@ fn mysql_tokens(item: &DeriveInput, model: &Model) -> Option<TokenStream> {
     model
         .mysql_type
         .as_ref()
-        .map(|mysql_type| Ident::new(&mysql_type.name.value(), Span::call_site()))
+        .map(|mysql_type| Ident::new(&mysql_type.name.value(), Span::mixed_site()))
         .and_then(|ty| {
             if cfg!(not(feature = "mysql")) {
                 return None;

diesel_derives/src/table.rs

@@ -1,5 +1,5 @@
 use diesel_table_macro_syntax::{ColumnDef, TableDecl};
-use proc_macro2::TokenStream;
+use proc_macro2::{Span, TokenStream};
 use syn::parse_quote;
 use syn::Ident;
 
@@ -46,10 +46,10 @@ pub(crate) fn expand(input: TableDecl) -> TokenStream {
     let primary_key: TokenStream = match input.primary_keys.as_ref() {
         None if column_names.contains(&&syn::Ident::new(
             DEFAULT_PRIMARY_KEY_NAME,
-            proc_macro2::Span::call_site(),
+            proc_macro2::Span::mixed_site(),
         )) =>
         {
-            let id = syn::Ident::new(DEFAULT_PRIMARY_KEY_NAME, proc_macro2::Span::call_site());
+            let id = syn::Ident::new(DEFAULT_PRIMARY_KEY_NAME, proc_macro2::Span::mixed_site());
             parse_quote! {
                 #id
             }
@@ -76,7 +76,7 @@ pub(crate) fn expand(input: TableDecl) -> TokenStream {
             }
             message += "\t}\n}";
 
-            let span = input.table_name.span();
+            let span = Span::mixed_site().located_at(input.table_name.span());
             return quote::quote_spanned! {span=>
                 compile_error!(#message);
             };
@@ -129,7 +129,7 @@ pub(crate) fn expand(input: TableDecl) -> TokenStream {
     let reexport_column_from_dsl = input.column_defs.iter().map(|c| {
         let column_name = &c.column_name;
         if c.column_name == *table_name {
-            let span = c.column_name.span();
+            let span = Span::mixed_site().located_at(c.column_name.span());
             let message = format!(
                 "Column `{column_name}` cannot be named the same as it's table.\n\
                  You may use `#[sql_name = \"{column_name}\"]` to reference the table's \
@@ -527,15 +527,15 @@ fn generate_valid_grouping_for_table_columns(table: &TableDecl) -> Vec<TokenStre
     for (id, right_col) in table.column_defs.iter().enumerate() {
         for left_col in table.column_defs.iter().skip(id) {
             let right_to_left = if Some(left_col.column_name.to_string()) == primary_key {
-                Ident::new("Yes", proc_macro2::Span::call_site())
+                Ident::new("Yes", proc_macro2::Span::mixed_site())
             } else {
-                Ident::new("No", proc_macro2::Span::call_site())
+                Ident::new("No", proc_macro2::Span::mixed_site())
             };
 
             let left_to_right = if Some(right_col.column_name.to_string()) == primary_key {
-                Ident::new("Yes", proc_macro2::Span::call_site())
+                Ident::new("Yes", proc_macro2::Span::mixed_site())
             } else {
-                Ident::new("No", proc_macro2::Span::call_site())
+                Ident::new("No", proc_macro2::Span::mixed_site())
             };
 
             let left_col = &left_col.column_name;
@@ -684,7 +684,7 @@ fn generate_op_impl(op: &str, tpe: &syn::Ident) -> TokenStream {
 fn expand_column_def(column_def: &ColumnDef) -> TokenStream {
     // TODO get a better span here as soon as that's
     // possible using stable rust
-    let span = column_def.column_name.span();
+    let span = Span::mixed_site().located_at(column_def.column_name.span());
     let meta = &column_def.meta;
     let column_name = &column_def.column_name;
     let sql_name = &column_def.sql_name;

diesel_derives/src/util.rs

@@ -93,7 +93,8 @@ where
 }
 
 pub fn wrap_in_dummy_mod(item: TokenStream) -> TokenStream {
-    // #[allow(unused_qualifications)] can be removed if https://github.com/rust-lang/rust/issues/130277 gets done
+    // allow(unused_qualifications) is here as it hard to unsure the span is correctly set. Should stay until it is
+    // checked by CI. See https://github.com/rust-lang/rust/issues/130277 for more details.
     quote! {
         #[allow(unused_imports)]
         #[allow(unused_qualifications)]
@@ -154,12 +155,12 @@ pub fn ty_for_foreign_derive(item: &DeriveInput, model: &Model) -> Result<Type>
             Data::Struct(ref body) => match body.fields.iter().next() {
                 Some(field) => Ok(field.ty.clone()),
                 None => Err(syn::Error::new(
-                    proc_macro2::Span::call_site(),
+                    proc_macro2::Span::mixed_site(),
                     "foreign_derive requires at least one field",
                 )),
             },
             _ => Err(syn::Error::new(
-                proc_macro2::Span::call_site(),
+                proc_macro2::Span::mixed_site(),
                 "foreign_derive can only be used with structs",
             )),
         }

dsl_auto_type/src/auto_type/mod.rs

@@ -66,7 +66,7 @@ pub(crate) fn auto_type_impl(
         (false, true, _) => false,
         (true, true, _) => {
             return Err(syn::Error::new(
-                Span::call_site(),
+                Span::mixed_site(),
                 "type_alias and no_type_alias are mutually exclusive",
             )
             .into())