macros: add more documentation comments

Documentation comments are always good.

Signed-off-by: David Wood <david.wood@huawei.com>
This commit is contained in:
David Wood 2022-04-27 05:24:31 +01:00
parent 2647a4812c
commit e8ee0d7a20
3 changed files with 13 additions and 1 deletions

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@ -14,7 +14,7 @@ use std::collections::HashMap;
use syn::{spanned::Spanned, Attribute, Meta, MetaList, MetaNameValue, Type};
use synstructure::Structure;
/// The central struct for constructing the `as_error` method from an annotated struct.
/// The central struct for constructing the `into_diagnostic` method from an annotated struct.
pub(crate) struct SessionDiagnosticDerive<'a> {
structure: Structure<'a>,
builder: SessionDiagnosticDeriveBuilder,

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@ -16,6 +16,8 @@ use std::str::FromStr;
use syn::{spanned::Spanned, Meta, MetaList, MetaNameValue};
use synstructure::{BindingInfo, Structure, VariantInfo};
/// `Applicability` of a suggestion - mirrors `rustc_errors::Applicability` - and used to represent
/// the user's selection of applicability if specified in an attribute.
enum Applicability {
MachineApplicable,
MaybeIncorrect,
@ -56,6 +58,7 @@ impl quote::ToTokens for Applicability {
}
}
/// Which kind of suggestion is being created?
#[derive(Clone, Copy)]
enum SubdiagnosticSuggestionKind {
/// `#[suggestion]`
@ -68,6 +71,7 @@ enum SubdiagnosticSuggestionKind {
Verbose,
}
/// Which kind of subdiagnostic is being created from a variant?
#[derive(Clone, Copy)]
enum SubdiagnosticKind {
/// `#[label(...)]`
@ -129,6 +133,7 @@ impl quote::IdentFragment for SubdiagnosticKind {
}
}
/// The central struct for constructing the `add_to_diagnostic` method from an annotated struct.
pub(crate) struct SessionSubdiagnosticDerive<'a> {
structure: Structure<'a>,
diag: syn::Ident,
@ -210,6 +215,10 @@ impl<'a> SessionSubdiagnosticDerive<'a> {
}
}
/// Tracks persistent information required for building up the call to add to the diagnostic
/// for the final generated method. This is a separate struct to `SessionSubdiagnosticDerive`
/// only to be able to destructure and split `self.builder` and the `self.structure` up to avoid a
/// double mut borrow later on.
struct SessionSubdiagnosticDeriveBuilder<'a> {
/// The identifier to use for the generated `DiagnosticBuilder` instance.
diag: &'a syn::Ident,

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@ -102,6 +102,8 @@ pub(crate) struct FieldInfo<'a> {
pub(crate) span: &'a proc_macro2::Span,
}
/// Small helper trait for abstracting over `Option` fields that contain a value and a `Span`
/// for error reporting if they are set more than once.
pub(crate) trait SetOnce<T> {
fn set_once(&mut self, value: T);
}
@ -122,6 +124,7 @@ impl<T> SetOnce<(T, Span)> for Option<(T, Span)> {
}
pub(crate) trait HasFieldMap {
/// Returns the binding for the field with the given name, if it exists on the type.
fn get_field_binding(&self, field: &String) -> Option<&TokenStream>;
/// In the strings in the attributes supplied to this macro, we want callers to be able to