Use call site hygiene in FromForm derive.

This commit changes the `FromForm` derive codegen so that it
consistently emits tokens with call site hygiene. This allows `FromForm`
derives to be emitted my macros more reliably.

Author: SergioBenitez

core/codegen/src/derive/form_field.rs

@@ -9,6 +9,14 @@ use quote::{ToTokens, TokenStreamExt};
 use crate::syn_ext::IdentExt;
 use crate::name::Name;
 
+macro_rules! quote_spanned {
+    ($span:expr => $($token:tt)*) => (
+        quote::quote_spanned!(
+            proc_macro2::Span::call_site().located_at($span) => $($token)*
+        )
+    )
+}
+
 #[derive(Debug)]
 pub enum FieldName {
     Cased(Name),

core/codegen/src/derive/from_form.rs

@@ -4,11 +4,20 @@ use syn::parse::Parser;
 use devise::*;
 
 use crate::exports::*;
-use crate::derive::form_field::{*, FieldName::*};
+use crate::derive::form_field::FieldName::*;
+use crate::derive::form_field::{FieldExt, default, first_duplicate, validators};
 use crate::syn_ext::{GenericsExt as _, TypeExt as _};
 
 type WherePredicates = syn::punctuated::Punctuated<syn::WherePredicate, syn::Token![,]>;
 
+macro_rules! quote_spanned {
+    ($span:expr => $($token:tt)*) => (
+        quote::quote_spanned!(
+            proc_macro2::Span::call_site().located_at($span) => $($token)*
+        )
+    )
+}
+
 // F: fn(field_ty: Ty, field_context: Expr)
 fn fields_map<F>(fields: Fields<'_>, map_f: F) -> Result<TokenStream>
     where F: Fn(&syn::Type, &syn::Expr) -> TokenStream
@@ -32,8 +41,8 @@ fn fields_map<F>(fields: Fields<'_>, map_f: F) -> Result<TokenStream>
         }
 
         matchers.extend(field.field_names()?.into_iter().map(|f| match f {
-            Cased(name) => quote!(#name => { #push }),
-            Uncased(name) => quote!(__n if __n.as_uncased() == #name => { #push }),
+            Cased(f) => quote_spanned!(ty.span() => #f => { #push }),
+            Uncased(f) => quote_spanned!(ty.span() => __n if __n.as_uncased() == #f => { #push }),
         }));
     }
 
@@ -192,7 +201,7 @@ pub fn derive_from_form(input: proc_macro::TokenStream) -> TokenStream {
                 let (ctxt_ty, gen) = context_type(input)?;
                 let (_, ty_gen, _) = gen.split_for_impl();
                 let output = mapper::input_default(mapper, input)?;
-                Ok(quote! {
+                Ok(quote_spanned! { ctxt_ty.span() =>
                     async fn push_data(
                         __c: &mut #ctxt_ty #ty_gen,
                         __f: #_form::DataField<'r, '_>
@@ -234,7 +243,7 @@ pub fn derive_from_form(input: proc_macro::TokenStream) -> TokenStream {
                 let ident = fields.iter().map(|f| f.context_ident());
                 let builder = fields.builder(|f| {
                     let ident = f.context_ident();
-                    quote!(#ident.unwrap())
+                    quote_spanned!(ident.span() => #ident.unwrap())
                 });
 
                 Ok(quote_spanned!(fields.span() =>

core/codegen/tests/from_form.rs

@@ -991,3 +991,50 @@ struct Q<T>(T);
 // This is here to ensure we don't warn, which we can't test with trybuild.
 #[derive(FromForm)]
 pub struct JsonTokenBad<T>(Q<T>);
+
+#[test]
+fn range() {
+    use std::ops::{Range, RangeFrom, RangeTo, RangeToInclusive};
+
+    let range: Range<usize> = strict("start=1&end=2").unwrap();
+    assert_eq!(range, Range { start: 1, end: 2 });
+
+    let range: Range<isize> = strict_encoded("start=-1&end=2").unwrap();
+    assert_eq!(range, Range { start: -1, end: 2 });
+
+    let range: Range<isize> = strict("start=-1&end=-95").unwrap();
+    assert_eq!(range, Range { start: -1, end: -95 });
+
+    let range: Range<isize> = strict_encoded("start=-1&end=-95").unwrap();
+    assert_eq!(range, Range { start: -1, end: -95 });
+
+    let range: RangeFrom<char> = strict("start=a").unwrap();
+    assert_eq!(range, RangeFrom { start: 'a' });
+
+    let range: RangeTo<char> = strict("end=z").unwrap();
+    assert_eq!(range, RangeTo { end: 'z' });
+
+    let range: RangeToInclusive<u8> = strict("end=255").unwrap();
+    assert_eq!(range, RangeToInclusive { end: 255 });
+
+    // now with compound, non-Step values
+    let form_string = &["start.start=0", "start.end=1", "end.start=1", "end.end=2"].join("&");
+    let range: Range<Range<usize>> = strict(&form_string).unwrap();
+    assert_eq!(range, Range {
+        start: Range { start: 0, end : 1},
+        end: Range { start: 1, end : 2 }
+    });
+
+    let form_string = &[
+        "start.description=some%20task",
+        "start.completed=false",
+        "end.description=yet%20more%20work",
+        "end.completed=true",
+    ].join("&");
+
+    let range: Range<TodoTask> = strict_encoded(form_string).unwrap();
+    assert_eq!(range, Range {
+        start: TodoTask { description: "some task".into(), completed: false, },
+        end: TodoTask { description: "yet more work".into(), completed: true, },
+    });
+}

core/codegen/tests/ui-fail-nightly/from_form.stderr

@@ -379,6 +379,9 @@ note: error occurred while deriving `FromForm`
 error: duplicate default field expression
    --> tests/ui-fail-nightly/from_form.rs:184:23
     |
+181 | #[derive(FromForm)]
+    |          -------- in this derive macro expansion
+...
 184 |     #[field(default = 2)]
     |                       ^
     |
@@ -393,6 +396,9 @@ note: error occurred while deriving `FromForm`
 error: duplicate default expressions
    --> tests/ui-fail-nightly/from_form.rs:190:23
     |
+188 | #[derive(FromForm)]
+    |          -------- in this derive macro expansion
+189 | struct Default3 {
 190 |     #[field(default = 1, default_with = None)]
     |                       ^
     |
@@ -412,6 +418,9 @@ note: error occurred while deriving `FromForm`
 error: duplicate default expressions
    --> tests/ui-fail-nightly/from_form.rs:197:23
     |
+194 | #[derive(FromForm)]
+    |          -------- in this derive macro expansion
+...
 197 |     #[field(default = 1)]
     |                       ^
     |
@@ -487,13 +496,17 @@ error[E0308]: mismatched types
 help: the type constructed contains `{integer}` due to the type of the argument passed
    --> tests/ui-fail-nightly/from_form.rs:171:23
     |
+169 | #[derive(FromForm)]
+    |          -------- in this derive macro expansion
+170 | struct Default0 {
 171 |     #[field(default = 123)]
     |                       ^^^ this argument influences the type of `Some`
 note: tuple variant defined here
    --> $RUST/core/src/option.rs
     |
     |     Some(#[stable(feature = "rust1", since = "1.0.0")] T),
     |     ^^^^
+    = note: this error originates in the derive macro `FromForm` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0308]: mismatched types
    --> tests/ui-fail-nightly/from_form.rs:203:33
@@ -520,8 +533,14 @@ note: tuple variant defined here
 error[E0277]: the trait bound `bool: From<&str>` is not satisfied
    --> tests/ui-fail-nightly/from_form.rs:209:23
     |
+207 | #[derive(FromForm)]
+    |          -------- in this derive macro expansion
+208 | struct Default6 {
 209 |     #[field(default = "no conversion")]
-    |                       ^^^^^^^^^^^^^^^ the trait `From<&str>` is not implemented for `bool`, which is required by `&str: Into<_>`
+    |                       ^^^^^^^^^^^^^^^
+    |                       |
+    |                       the trait `From<&str>` is not implemented for `bool`, which is required by `&str: Into<_>`
+    |                       this tail expression is of type `&str`
     |
     = help: the following other types implement trait `From<T>`:
               <bool as From<format_description::parse::format_item::HourBase>>
@@ -533,3 +552,4 @@ error[E0277]: the trait bound `bool: From<&str>` is not satisfied
               <bool as From<format_description::parse::format_item::WeekdayOneIndexed>>
               <bool as From<format_description::parse::format_item::YearBase>>
     = note: required for `&str` to implement `Into<bool>`
+    = note: this error originates in the derive macro `FromForm` (in Nightly builds, run with -Z macro-backtrace for more info)

core/codegen/tests/ui-fail-nightly/from_form_type_errors.stderr

@@ -19,8 +19,13 @@ error[E0277]: the trait bound `Unknown: FromFormField<'_>` is not satisfied
 error[E0277]: the trait bound `Unknown: FromFormField<'_>` is not satisfied
  --> tests/ui-fail-nightly/from_form_type_errors.rs:5:10
   |
-5 | #[derive(FromForm)]
-  |          ^^^^^^^^ the trait `FromFormField<'_>` is not implemented for `Unknown`, which is required by `_::FromFormGeneratedContext<'r>: std::marker::Send`
+5 |   #[derive(FromForm)]
+  |            ^-------
+  |            |
+  |  __________in this derive macro expansion
+  | |
+6 | | struct BadType3 {
+  | |_______________^ the trait `FromFormField<'_>` is not implemented for `Unknown`, which is required by `_::FromFormGeneratedContext<'r>: std::marker::Send`
   |
   = help: the following other types implement trait `FromFormField<'v>`:
             &'v [u8]
@@ -36,6 +41,8 @@ error[E0277]: the trait bound `Unknown: FromFormField<'_>` is not satisfied
 note: required because it appears within the type `_::FromFormGeneratedContext<'r>`
  --> tests/ui-fail-nightly/from_form_type_errors.rs:6:8
   |
+5 | #[derive(FromForm)]
+  |          -------- in this derive macro expansion
 6 | struct BadType3 {
   |        ^^^^^^^^
 note: required by a bound in `rocket::form::FromForm::Context`
@@ -66,8 +73,13 @@ error[E0277]: the trait bound `Foo<usize>: FromFormField<'_>` is not satisfied
 error[E0277]: the trait bound `Foo<usize>: FromFormField<'_>` is not satisfied
   --> tests/ui-fail-nightly/from_form_type_errors.rs:12:10
    |
-12 | #[derive(FromForm)]
-   |          ^^^^^^^^ the trait `FromFormField<'_>` is not implemented for `Foo<usize>`, which is required by `_::FromFormGeneratedContext<'r>: std::marker::Send`
+12 |   #[derive(FromForm)]
+   |            ^-------
+   |            |
+   |  __________in this derive macro expansion
+   | |
+13 | | struct Other {
+   | |____________^ the trait `FromFormField<'_>` is not implemented for `Foo<usize>`, which is required by `_::FromFormGeneratedContext<'r>: std::marker::Send`
    |
    = help: the following other types implement trait `FromFormField<'v>`:
              &'v [u8]
@@ -83,6 +95,8 @@ error[E0277]: the trait bound `Foo<usize>: FromFormField<'_>` is not satisfied
 note: required because it appears within the type `_::FromFormGeneratedContext<'r>`
   --> tests/ui-fail-nightly/from_form_type_errors.rs:13:8
    |
+12 | #[derive(FromForm)]
+   |          -------- in this derive macro expansion
 13 | struct Other {
    |        ^^^^^
 note: required by a bound in `rocket::form::FromForm::Context`
@@ -111,29 +125,32 @@ error[E0277]: the trait bound `Unknown: FromFormField<'_>` is not satisfied
   = note: required for `Unknown` to implement `FromForm<'r>`
   = note: this error originates in the derive macro `FromForm` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error[E0277]: the trait bound `Unknown: FromFormField<'_>` is not satisfied
- --> tests/ui-fail-nightly/from_form_type_errors.rs:7:5
+error[E0277]: the trait bound `Unknown: FromForm<'r>` is not satisfied
+ --> tests/ui-fail-nightly/from_form_type_errors.rs:7:12
   |
 7 |     field: Unknown,
-  |     ^^^^^^^^^^^^^^ the trait `FromFormField<'_>` is not implemented for `Unknown`, which is required by `Unknown: FromForm<'r>`
+  |            ^^^^^^^ the trait `FromFormField<'_>` is not implemented for `Unknown`, which is required by `Unknown: FromForm<'r>`
   |
-  = help: the following other types implement trait `FromFormField<'v>`:
-            &'v [u8]
-            &'v str
-            Capped<&'v [u8]>
-            Capped<&'v str>
-            Capped<Cow<'v, str>>
-            Capped<TempFile<'v>>
-            Capped<std::string::String>
-            Cow<'v, str>
+  = help: the following other types implement trait `FromForm<'r>`:
+            <(A, B) as FromForm<'v>>
+            <Arc<T> as FromForm<'v>>
+            <BTreeMap<K, V> as FromForm<'v>>
+            <BadType3 as FromForm<'r>>
+            <Contextual<'v, T> as FromForm<'v>>
+            <HashMap<K, V> as FromForm<'v>>
+            <Lenient<T> as FromForm<'v>>
+            <Other as FromForm<'r>>
           and $N others
   = note: required for `Unknown` to implement `FromForm<'r>`
 
-error[E0277]: the trait bound `Unknown: FromFormField<'r>` is not satisfied
+error[E0277]: the trait bound `Unknown: FromFormField<'_>` is not satisfied
  --> tests/ui-fail-nightly/from_form_type_errors.rs:7:12
   |
+5 | #[derive(FromForm)]
+  |          -------- in this derive macro expansion
+6 | struct BadType3 {
 7 |     field: Unknown,
-  |            ^^^^^^^ the trait `FromFormField<'r>` is not implemented for `Unknown`
+  |            ^^^^^^^ the trait `FromFormField<'_>` is not implemented for `Unknown`, which is required by `Unknown: FromForm<'r>`
   |
   = help: the following other types implement trait `FromFormField<'v>`:
             &'v [u8]
@@ -145,11 +162,8 @@ error[E0277]: the trait bound `Unknown: FromFormField<'r>` is not satisfied
             Capped<std::string::String>
             Cow<'v, str>
           and $N others
-note: required by a bound in `FromFieldContext`
- --> $WORKSPACE/core/lib/src/form/from_form_field.rs
-  |
-  | pub struct FromFieldContext<'v, T: FromFormField<'v>> {
-  |                                    ^^^^^^^^^^^^^^^^^ required by this bound in `FromFieldContext`
+  = note: required for `Unknown` to implement `FromForm<'r>`
+  = note: this error originates in the derive macro `FromForm` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the trait bound `Foo<usize>: FromFormField<'_>` is not satisfied
   --> tests/ui-fail-nightly/from_form_type_errors.rs:12:10
@@ -170,29 +184,32 @@ error[E0277]: the trait bound `Foo<usize>: FromFormField<'_>` is not satisfied
    = note: required for `Foo<usize>` to implement `FromForm<'r>`
    = note: this error originates in the derive macro `FromForm` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error[E0277]: the trait bound `Foo<usize>: FromFormField<'_>` is not satisfied
-  --> tests/ui-fail-nightly/from_form_type_errors.rs:14:5
+error[E0277]: the trait bound `Foo<usize>: FromForm<'r>` is not satisfied
+  --> tests/ui-fail-nightly/from_form_type_errors.rs:14:12
    |
 14 |     field: Foo<usize>,
-   |     ^^^^^^^^^^^^^^^^^ the trait `FromFormField<'_>` is not implemented for `Foo<usize>`, which is required by `Foo<usize>: FromForm<'r>`
+   |            ^^^^^^^^^^ the trait `FromFormField<'_>` is not implemented for `Foo<usize>`, which is required by `Foo<usize>: FromForm<'r>`
    |
-   = help: the following other types implement trait `FromFormField<'v>`:
-             &'v [u8]
-             &'v str
-             Capped<&'v [u8]>
-             Capped<&'v str>
-             Capped<Cow<'v, str>>
-             Capped<TempFile<'v>>
-             Capped<std::string::String>
-             Cow<'v, str>
+   = help: the following other types implement trait `FromForm<'r>`:
+             <(A, B) as FromForm<'v>>
+             <Arc<T> as FromForm<'v>>
+             <BTreeMap<K, V> as FromForm<'v>>
+             <BadType3 as FromForm<'r>>
+             <Contextual<'v, T> as FromForm<'v>>
+             <HashMap<K, V> as FromForm<'v>>
+             <Lenient<T> as FromForm<'v>>
+             <Other as FromForm<'r>>
            and $N others
    = note: required for `Foo<usize>` to implement `FromForm<'r>`
 
-error[E0277]: the trait bound `Foo<usize>: FromFormField<'r>` is not satisfied
+error[E0277]: the trait bound `Foo<usize>: FromFormField<'_>` is not satisfied
   --> tests/ui-fail-nightly/from_form_type_errors.rs:14:12
    |
+12 | #[derive(FromForm)]
+   |          -------- in this derive macro expansion
+13 | struct Other {
 14 |     field: Foo<usize>,
-   |            ^^^^^^^^^^ the trait `FromFormField<'r>` is not implemented for `Foo<usize>`
+   |            ^^^^^^^^^^ the trait `FromFormField<'_>` is not implemented for `Foo<usize>`, which is required by `Foo<usize>: FromForm<'r>`
    |
    = help: the following other types implement trait `FromFormField<'v>`:
              &'v [u8]
@@ -204,8 +221,5 @@ error[E0277]: the trait bound `Foo<usize>: FromFormField<'r>` is not satisfied
              Capped<std::string::String>
              Cow<'v, str>
            and $N others
-note: required by a bound in `FromFieldContext`
-  --> $WORKSPACE/core/lib/src/form/from_form_field.rs
-   |
-   | pub struct FromFieldContext<'v, T: FromFormField<'v>> {
-   |                                    ^^^^^^^^^^^^^^^^^ required by this bound in `FromFieldContext`
+   = note: required for `Foo<usize>` to implement `FromForm<'r>`
+   = note: this error originates in the derive macro `FromForm` (in Nightly builds, run with -Z macro-backtrace for more info)