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macros: support MultiSpan in diag derives

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Add support for `MultiSpan` with any of the attributes that work on a
`Span` - requires that diagnostic logic generated for these attributes
are emitted in the by-move block rather than the by-ref block that they
would normally have been generated in.

Signed-off-by: David Wood <david.wood@huawei.com>
This commit is contained in:
David Wood 2022-07-11 17:15:31 +01:00
parent c3fdf74885
commit 88c11c5bff
6 changed files with 104 additions and 68 deletions
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139
compiler/rustc_macros/src/diagnostics/diagnostic_builder.rs
View File

@ -13,7 +13,8 @@
use std::collections::HashMap;
use std::str::FromStr;
use syn::{
parse_quote, spanned::Spanned, Attribute, Meta, MetaList, MetaNameValue, NestedMeta, Path, Type,
parse_quote, spanned::Spanned, Attribute, Field, Meta, MetaList, MetaNameValue, NestedMeta,
Path, Type,
};
use synstructure::{BindingInfo, Structure};
@ -80,8 +81,8 @@ pub fn preamble<'s>(&mut self, structure: &Structure<'s>) -> TokenStream {
}
pub fn body<'s>(&mut self, structure: &mut Structure<'s>) -> (TokenStream, TokenStream) {
// Keep track of which fields are subdiagnostics or have no attributes.
let mut subdiagnostics_or_empty = std::collections::HashSet::new();
// Keep track of which fields need to be handled with a by-move binding.
let mut needs_moved = std::collections::HashSet::new();
// Generates calls to `span_label` and similar functions based on the attributes
// on fields. Code for suggestions uses formatting machinery and the value of
@ -92,16 +93,11 @@ pub fn body<'s>(&mut self, structure: &mut Structure<'s>) -> (TokenStream, Token
let attrs = structure
.clone()
.filter(|field_binding| {
let attrs = &field_binding.ast().attrs;
(!attrs.is_empty()
&& attrs.iter().all(|attr| {
"subdiagnostic" != attr.path.segments.last().unwrap().ident.to_string()
}))
|| {
subdiagnostics_or_empty.insert(field_binding.binding.clone());
false
}
let ast = &field_binding.ast();
!self.needs_move(ast) || {
needs_moved.insert(field_binding.binding.clone());
false
}
})
.each(|field_binding| self.generate_field_attrs_code(field_binding));
@ -111,12 +107,41 @@ pub fn body<'s>(&mut self, structure: &mut Structure<'s>) -> (TokenStream, Token
// attributes or a `#[subdiagnostic]` attribute then it must be passed as an
// argument to the diagnostic so that it can be referred to by Fluent messages.
let args = structure
.filter(|field_binding| subdiagnostics_or_empty.contains(&field_binding.binding))
.filter(|field_binding| needs_moved.contains(&field_binding.binding))
.each(|field_binding| self.generate_field_attrs_code(field_binding));
(attrs, args)
}
/// Returns `true` if `field` should generate a `set_arg` call rather than any other diagnostic
/// call (like `span_label`).
fn should_generate_set_arg(&self, field: &Field) -> bool {
field.attrs.is_empty()
}
/// Returns `true` if `field` needs to have code generated in the by-move branch of the
/// generated derive rather than the by-ref branch.
fn needs_move(&self, field: &Field) -> bool {
let generates_set_arg = self.should_generate_set_arg(field);
let is_multispan = type_matches_path(&field.ty, &["rustc_errors", "MultiSpan"]);
// FIXME(davidtwco): better support for one field needing to be in the by-move and
// by-ref branches.
let is_subdiagnostic = field
.attrs
.iter()
.map(|attr| attr.path.segments.last().unwrap().ident.to_string())
.any(|attr| attr == "subdiagnostic");
// `set_arg` calls take their argument by-move..
generates_set_arg
// If this is a `MultiSpan` field then it needs to be moved to be used by any
// attribute..
|| is_multispan
// If this a `#[subdiagnostic]` then it needs to be moved as the other diagnostic is
// unlikely to be `Copy`..
|| is_subdiagnostic
}
/// Establishes state in the `DiagnosticDeriveBuilder` resulting from the struct
/// attributes like `#[error(..)`, such as the diagnostic kind and slug. Generates
/// diagnostic builder calls for setting error code and creating note/help messages.
@ -227,57 +252,55 @@ fn generate_field_attrs_code(&mut self, binding_info: &BindingInfo<'_>) -> Token
let field = binding_info.ast();
let field_binding = &binding_info.binding;
let inner_ty = FieldInnerTy::from_type(&field.ty);
// When generating `set_arg` or `add_subdiagnostic` calls, move data rather than
// borrow it to avoid requiring clones - this must therefore be the last use of
// each field (for example, any formatting machinery that might refer to a field
// should be generated already).
if field.attrs.is_empty() {
if self.should_generate_set_arg(&field) {
let diag = &self.diag;
let ident = field.ident.as_ref().unwrap();
quote! {
return quote! {
#diag.set_arg(
stringify!(#ident),
#field_binding
);
}
} else {
field
.attrs
.iter()
.map(move |attr| {
let name = attr.path.segments.last().unwrap().ident.to_string();
let (binding, needs_destructure) = match (name.as_str(), &inner_ty) {
// `primary_span` can accept a `Vec<Span>` so don't destructure that.
("primary_span", FieldInnerTy::Vec(_)) => {
(quote! { #field_binding.clone() }, false)
}
// `subdiagnostics` are not derefed because they are bound by value.
("subdiagnostic", _) => (quote! { #field_binding }, true),
_ => (quote! { *#field_binding }, true),
};
let generated_code = self
.generate_inner_field_code(
attr,
FieldInfo {
binding: binding_info,
ty: inner_ty.inner_type().unwrap_or(&field.ty),
span: &field.span(),
},
binding,
)
.unwrap_or_else(|v| v.to_compile_error());
if needs_destructure {
inner_ty.with(field_binding, generated_code)
} else {
generated_code
}
})
.collect()
};
}
let needs_move = self.needs_move(&field);
let inner_ty = FieldInnerTy::from_type(&field.ty);
field
.attrs
.iter()
.map(move |attr| {
let name = attr.path.segments.last().unwrap().ident.to_string();
let needs_clone =
name == "primary_span" && matches!(inner_ty, FieldInnerTy::Vec(_));
let (binding, needs_destructure) = if needs_clone {
// `primary_span` can accept a `Vec<Span>` so don't destructure that.
(quote! { #field_binding.clone() }, false)
} else if needs_move {
(quote! { #field_binding }, true)
} else {
(quote! { *#field_binding }, true)
};
let generated_code = self
.generate_inner_field_code(
attr,
FieldInfo {
binding: binding_info,
ty: inner_ty.inner_type().unwrap_or(&field.ty),
span: &field.span(),
},
binding,
)
.unwrap_or_else(|v| v.to_compile_error());
if needs_destructure {
inner_ty.with(field_binding, generated_code)
} else {
generated_code
}
})
.collect()
}
fn generate_inner_field_code(

8
compiler/rustc_macros/src/diagnostics/utils.rs
View File

@ -85,7 +85,13 @@ pub(crate) fn report_error_if_not_applied_to_span(
attr: &Attribute,
info: &FieldInfo<'_>,
) -> Result<(), DiagnosticDeriveError> {
report_error_if_not_applied_to_ty(attr, info, &["rustc_span", "Span"], "`Span`")
if !type_matches_path(&info.ty, &["rustc_span", "Span"])
&& !type_matches_path(&info.ty, &["rustc_errors", "MultiSpan"])
{
report_type_error(attr, "`Span` or `MultiSpan`")?;
}
Ok(())
}
/// Inner type of a field and type of wrapper.

15
src/test/ui-fulldeps/session-diagnostic/diagnostic-derive.rs
View File

@ -23,7 +23,7 @@
use rustc_middle::ty::Ty;
extern crate rustc_errors;
use rustc_errors::Applicability;
use rustc_errors::{Applicability, MultiSpan};
extern crate rustc_session;
@ -140,7 +140,7 @@ struct CodeNotProvided {}
#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
struct MessageWrongType {
#[primary_span]
//~^ ERROR `#[primary_span]` attribute can only be applied to fields of type `Span`
//~^ ERROR `#[primary_span]` attribute can only be applied to fields of type `Span` or `MultiSpan`
foo: String,
}
@ -165,7 +165,7 @@ struct ErrorWithField {
#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
struct ErrorWithMessageAppliedToField {
#[label(typeck::label)]
//~^ ERROR the `#[label(...)]` attribute can only be applied to fields of type `Span`
//~^ ERROR the `#[label(...)]` attribute can only be applied to fields of type `Span` or `MultiSpan`
name: String,
}
@ -208,7 +208,7 @@ struct LabelOnSpan {
#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
struct LabelOnNonSpan {
#[label(typeck::label)]
//~^ ERROR the `#[label(...)]` attribute can only be applied to fields of type `Span`
//~^ ERROR the `#[label(...)]` attribute can only be applied to fields of type `Span` or `MultiSpan`
id: u32,
}
@ -552,3 +552,10 @@ struct LintsGood {
//~^ ERROR only `#[lint(..)]` is supported
struct ErrorsBad {
}
#[derive(SessionDiagnostic)]
#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
struct ErrorWithMultiSpan {
#[primary_span]
span: MultiSpan,
}

6
src/test/ui-fulldeps/session-diagnostic/diagnostic-derive.stderr
View File

@ -233,7 +233,7 @@ LL | | struct SlugNotProvided {}
|
= help: specify the slug as the first argument to the attribute, such as `#[error(typeck::example_error)]`
error: the `#[primary_span]` attribute can only be applied to fields of type `Span`
error: the `#[primary_span]` attribute can only be applied to fields of type `Span` or `MultiSpan`
--> $DIR/diagnostic-derive.rs:142:5
|
LL | #[primary_span]
@ -247,7 +247,7 @@ LL | #[nonsense]
|
= help: only `skip_arg`, `primary_span`, `label`, `note`, `help` and `subdiagnostic` are valid field attributes
error: the `#[label(...)]` attribute can only be applied to fields of type `Span`
error: the `#[label(...)]` attribute can only be applied to fields of type `Span` or `MultiSpan`
--> $DIR/diagnostic-derive.rs:167:5
|
LL | #[label(typeck::label)]
@ -279,7 +279,7 @@ LL | #[derive(SessionDiagnostic)]
= note: if you intended to print `}`, you can escape it using `}}`
= note: this error originates in the derive macro `SessionDiagnostic` (in Nightly builds, run with -Z macro-backtrace for more info)
error: the `#[label(...)]` attribute can only be applied to fields of type `Span`
error: the `#[label(...)]` attribute can only be applied to fields of type `Span` or `MultiSpan`
--> $DIR/diagnostic-derive.rs:210:5
|
LL | #[label(typeck::label)]

2
src/test/ui-fulldeps/session-diagnostic/subdiagnostic-derive.rs
View File

@ -244,7 +244,7 @@ enum V {
//~^ ERROR label without `#[primary_span]` field
struct W {
#[primary_span]
//~^ ERROR the `#[primary_span]` attribute can only be applied to fields of type `Span`
//~^ ERROR the `#[primary_span]` attribute can only be applied to fields of type `Span` or `MultiSpan`
span: String,
}

2
src/test/ui-fulldeps/session-diagnostic/subdiagnostic-derive.stderr
View File

@ -120,7 +120,7 @@ error: subdiagnostic kind not specified
LL | B {
| ^
error: the `#[primary_span]` attribute can only be applied to fields of type `Span`
error: the `#[primary_span]` attribute can only be applied to fields of type `Span` or `MultiSpan`
--> $DIR/subdiagnostic-derive.rs:246:5
|
LL | #[primary_span]