diff options
Diffstat (limited to 'vendor/thiserror-impl/src/expand.rs')
| -rw-r--r-- | vendor/thiserror-impl/src/expand.rs | 583 |
1 files changed, 0 insertions, 583 deletions
diff --git a/vendor/thiserror-impl/src/expand.rs b/vendor/thiserror-impl/src/expand.rs deleted file mode 100644 index c6939214..00000000 --- a/vendor/thiserror-impl/src/expand.rs +++ /dev/null @@ -1,583 +0,0 @@ -use crate::ast::{Enum, Field, Input, Struct}; -use crate::attr::Trait; -use crate::fallback; -use crate::generics::InferredBounds; -use crate::unraw::MemberUnraw; -use proc_macro2::{Ident, Span, TokenStream}; -use quote::{format_ident, quote, quote_spanned, ToTokens}; -use std::collections::BTreeSet as Set; -use syn::{DeriveInput, GenericArgument, PathArguments, Result, Token, Type}; - -pub fn derive(input: &DeriveInput) -> TokenStream { - match try_expand(input) { - Ok(expanded) => expanded, - // If there are invalid attributes in the input, expand to an Error impl - // anyway to minimize spurious secondary errors in other code that uses - // this type as an Error. - Err(error) => fallback::expand(input, error), - } -} - -fn try_expand(input: &DeriveInput) -> Result<TokenStream> { - let input = Input::from_syn(input)?; - input.validate()?; - Ok(match input { - Input::Struct(input) => impl_struct(input), - Input::Enum(input) => impl_enum(input), - }) -} - -fn impl_struct(input: Struct) -> TokenStream { - let ty = call_site_ident(&input.ident); - let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl(); - let mut error_inferred_bounds = InferredBounds::new(); - - let source_body = if let Some(transparent_attr) = &input.attrs.transparent { - let only_field = &input.fields[0]; - if only_field.contains_generic { - error_inferred_bounds.insert(only_field.ty, quote!(::thiserror::__private::Error)); - } - let member = &only_field.member; - Some(quote_spanned! {transparent_attr.span=> - ::thiserror::__private::Error::source(self.#member.as_dyn_error()) - }) - } else if let Some(source_field) = input.source_field() { - let source = &source_field.member; - if source_field.contains_generic { - let ty = unoptional_type(source_field.ty); - error_inferred_bounds.insert(ty, quote!(::thiserror::__private::Error + 'static)); - } - let asref = if type_is_option(source_field.ty) { - Some(quote_spanned!(source.span()=> .as_ref()?)) - } else { - None - }; - let dyn_error = quote_spanned! {source_field.source_span()=> - self.#source #asref.as_dyn_error() - }; - Some(quote! { - ::core::option::Option::Some(#dyn_error) - }) - } else { - None - }; - let source_method = source_body.map(|body| { - quote! { - fn source(&self) -> ::core::option::Option<&(dyn ::thiserror::__private::Error + 'static)> { - use ::thiserror::__private::AsDynError as _; - #body - } - } - }); - - let provide_method = input.backtrace_field().map(|backtrace_field| { - let request = quote!(request); - let backtrace = &backtrace_field.member; - let body = if let Some(source_field) = input.source_field() { - let source = &source_field.member; - let source_provide = if type_is_option(source_field.ty) { - quote_spanned! {source.span()=> - if let ::core::option::Option::Some(source) = &self.#source { - source.thiserror_provide(#request); - } - } - } else { - quote_spanned! {source.span()=> - self.#source.thiserror_provide(#request); - } - }; - let self_provide = if source == backtrace { - None - } else if type_is_option(backtrace_field.ty) { - Some(quote! { - if let ::core::option::Option::Some(backtrace) = &self.#backtrace { - #request.provide_ref::<::thiserror::__private::Backtrace>(backtrace); - } - }) - } else { - Some(quote! { - #request.provide_ref::<::thiserror::__private::Backtrace>(&self.#backtrace); - }) - }; - quote! { - use ::thiserror::__private::ThiserrorProvide as _; - #source_provide - #self_provide - } - } else if type_is_option(backtrace_field.ty) { - quote! { - if let ::core::option::Option::Some(backtrace) = &self.#backtrace { - #request.provide_ref::<::thiserror::__private::Backtrace>(backtrace); - } - } - } else { - quote! { - #request.provide_ref::<::thiserror::__private::Backtrace>(&self.#backtrace); - } - }; - quote! { - fn provide<'_request>(&'_request self, #request: &mut ::core::error::Request<'_request>) { - #body - } - } - }); - - let mut display_implied_bounds = Set::new(); - let display_body = if input.attrs.transparent.is_some() { - let only_field = &input.fields[0].member; - display_implied_bounds.insert((0, Trait::Display)); - Some(quote! { - ::core::fmt::Display::fmt(&self.#only_field, __formatter) - }) - } else if let Some(display) = &input.attrs.display { - display_implied_bounds.clone_from(&display.implied_bounds); - let use_as_display = use_as_display(display.has_bonus_display); - let pat = fields_pat(&input.fields); - Some(quote! { - #use_as_display - #[allow(unused_variables, deprecated)] - let Self #pat = self; - #display - }) - } else { - None - }; - let display_impl = display_body.map(|body| { - let mut display_inferred_bounds = InferredBounds::new(); - for (field, bound) in display_implied_bounds { - let field = &input.fields[field]; - if field.contains_generic { - display_inferred_bounds.insert(field.ty, bound); - } - } - let display_where_clause = display_inferred_bounds.augment_where_clause(input.generics); - quote! { - #[allow(unused_qualifications)] - #[automatically_derived] - impl #impl_generics ::core::fmt::Display for #ty #ty_generics #display_where_clause { - #[allow(clippy::used_underscore_binding)] - fn fmt(&self, __formatter: &mut ::core::fmt::Formatter) -> ::core::fmt::Result { - #body - } - } - } - }); - - let from_impl = input.from_field().map(|from_field| { - let span = from_field.attrs.from.unwrap().span; - let backtrace_field = input.distinct_backtrace_field(); - let from = unoptional_type(from_field.ty); - let source_var = Ident::new("source", span); - let body = from_initializer(from_field, backtrace_field, &source_var); - let from_function = quote! { - fn from(#source_var: #from) -> Self { - #ty #body - } - }; - let from_impl = quote_spanned! {span=> - #[automatically_derived] - impl #impl_generics ::core::convert::From<#from> for #ty #ty_generics #where_clause { - #from_function - } - }; - Some(quote! { - #[allow( - deprecated, - unused_qualifications, - clippy::elidable_lifetime_names, - clippy::needless_lifetimes, - )] - #from_impl - }) - }); - - if input.generics.type_params().next().is_some() { - let self_token = <Token![Self]>::default(); - error_inferred_bounds.insert(self_token, Trait::Debug); - error_inferred_bounds.insert(self_token, Trait::Display); - } - let error_where_clause = error_inferred_bounds.augment_where_clause(input.generics); - - quote! { - #[allow(unused_qualifications)] - #[automatically_derived] - impl #impl_generics ::thiserror::__private::Error for #ty #ty_generics #error_where_clause { - #source_method - #provide_method - } - #display_impl - #from_impl - } -} - -fn impl_enum(input: Enum) -> TokenStream { - let ty = call_site_ident(&input.ident); - let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl(); - let mut error_inferred_bounds = InferredBounds::new(); - - let source_method = if input.has_source() { - let arms = input.variants.iter().map(|variant| { - let ident = &variant.ident; - if let Some(transparent_attr) = &variant.attrs.transparent { - let only_field = &variant.fields[0]; - if only_field.contains_generic { - error_inferred_bounds.insert(only_field.ty, quote!(::thiserror::__private::Error)); - } - let member = &only_field.member; - let source = quote_spanned! {transparent_attr.span=> - ::thiserror::__private::Error::source(transparent.as_dyn_error()) - }; - quote! { - #ty::#ident {#member: transparent} => #source, - } - } else if let Some(source_field) = variant.source_field() { - let source = &source_field.member; - if source_field.contains_generic { - let ty = unoptional_type(source_field.ty); - error_inferred_bounds.insert(ty, quote!(::thiserror::__private::Error + 'static)); - } - let asref = if type_is_option(source_field.ty) { - Some(quote_spanned!(source.span()=> .as_ref()?)) - } else { - None - }; - let varsource = quote!(source); - let dyn_error = quote_spanned! {source_field.source_span()=> - #varsource #asref.as_dyn_error() - }; - quote! { - #ty::#ident {#source: #varsource, ..} => ::core::option::Option::Some(#dyn_error), - } - } else { - quote! { - #ty::#ident {..} => ::core::option::Option::None, - } - } - }); - Some(quote! { - fn source(&self) -> ::core::option::Option<&(dyn ::thiserror::__private::Error + 'static)> { - use ::thiserror::__private::AsDynError as _; - #[allow(deprecated)] - match self { - #(#arms)* - } - } - }) - } else { - None - }; - - let provide_method = if input.has_backtrace() { - let request = quote!(request); - let arms = input.variants.iter().map(|variant| { - let ident = &variant.ident; - match (variant.backtrace_field(), variant.source_field()) { - (Some(backtrace_field), Some(source_field)) - if backtrace_field.attrs.backtrace.is_none() => - { - let backtrace = &backtrace_field.member; - let source = &source_field.member; - let varsource = quote!(source); - let source_provide = if type_is_option(source_field.ty) { - quote_spanned! {source.span()=> - if let ::core::option::Option::Some(source) = #varsource { - source.thiserror_provide(#request); - } - } - } else { - quote_spanned! {source.span()=> - #varsource.thiserror_provide(#request); - } - }; - let self_provide = if type_is_option(backtrace_field.ty) { - quote! { - if let ::core::option::Option::Some(backtrace) = backtrace { - #request.provide_ref::<::thiserror::__private::Backtrace>(backtrace); - } - } - } else { - quote! { - #request.provide_ref::<::thiserror::__private::Backtrace>(backtrace); - } - }; - quote! { - #ty::#ident { - #backtrace: backtrace, - #source: #varsource, - .. - } => { - use ::thiserror::__private::ThiserrorProvide as _; - #source_provide - #self_provide - } - } - } - (Some(backtrace_field), Some(source_field)) - if backtrace_field.member == source_field.member => - { - let backtrace = &backtrace_field.member; - let varsource = quote!(source); - let source_provide = if type_is_option(source_field.ty) { - quote_spanned! {backtrace.span()=> - if let ::core::option::Option::Some(source) = #varsource { - source.thiserror_provide(#request); - } - } - } else { - quote_spanned! {backtrace.span()=> - #varsource.thiserror_provide(#request); - } - }; - quote! { - #ty::#ident {#backtrace: #varsource, ..} => { - use ::thiserror::__private::ThiserrorProvide as _; - #source_provide - } - } - } - (Some(backtrace_field), _) => { - let backtrace = &backtrace_field.member; - let body = if type_is_option(backtrace_field.ty) { - quote! { - if let ::core::option::Option::Some(backtrace) = backtrace { - #request.provide_ref::<::thiserror::__private::Backtrace>(backtrace); - } - } - } else { - quote! { - #request.provide_ref::<::thiserror::__private::Backtrace>(backtrace); - } - }; - quote! { - #ty::#ident {#backtrace: backtrace, ..} => { - #body - } - } - } - (None, _) => quote! { - #ty::#ident {..} => {} - }, - } - }); - Some(quote! { - fn provide<'_request>(&'_request self, #request: &mut ::core::error::Request<'_request>) { - #[allow(deprecated)] - match self { - #(#arms)* - } - } - }) - } else { - None - }; - - let display_impl = if input.has_display() { - let mut display_inferred_bounds = InferredBounds::new(); - let has_bonus_display = input.variants.iter().any(|v| { - v.attrs - .display - .as_ref() - .map_or(false, |display| display.has_bonus_display) - }); - let use_as_display = use_as_display(has_bonus_display); - let void_deref = if input.variants.is_empty() { - Some(quote!(*)) - } else { - None - }; - let arms = input.variants.iter().map(|variant| { - let mut display_implied_bounds = Set::new(); - let display = if let Some(display) = &variant.attrs.display { - display_implied_bounds.clone_from(&display.implied_bounds); - display.to_token_stream() - } else if let Some(fmt) = &variant.attrs.fmt { - let fmt_path = &fmt.path; - let vars = variant.fields.iter().map(|field| match &field.member { - MemberUnraw::Named(ident) => ident.to_local(), - MemberUnraw::Unnamed(index) => format_ident!("_{}", index), - }); - quote!(#fmt_path(#(#vars,)* __formatter)) - } else { - let only_field = match &variant.fields[0].member { - MemberUnraw::Named(ident) => ident.to_local(), - MemberUnraw::Unnamed(index) => format_ident!("_{}", index), - }; - display_implied_bounds.insert((0, Trait::Display)); - quote!(::core::fmt::Display::fmt(#only_field, __formatter)) - }; - for (field, bound) in display_implied_bounds { - let field = &variant.fields[field]; - if field.contains_generic { - display_inferred_bounds.insert(field.ty, bound); - } - } - let ident = &variant.ident; - let pat = fields_pat(&variant.fields); - quote! { - #ty::#ident #pat => #display - } - }); - let arms = arms.collect::<Vec<_>>(); - let display_where_clause = display_inferred_bounds.augment_where_clause(input.generics); - Some(quote! { - #[allow(unused_qualifications)] - #[automatically_derived] - impl #impl_generics ::core::fmt::Display for #ty #ty_generics #display_where_clause { - fn fmt(&self, __formatter: &mut ::core::fmt::Formatter) -> ::core::fmt::Result { - #use_as_display - #[allow(unused_variables, deprecated, clippy::used_underscore_binding)] - match #void_deref self { - #(#arms,)* - } - } - } - }) - } else { - None - }; - - let from_impls = input.variants.iter().filter_map(|variant| { - let from_field = variant.from_field()?; - let span = from_field.attrs.from.unwrap().span; - let backtrace_field = variant.distinct_backtrace_field(); - let variant = &variant.ident; - let from = unoptional_type(from_field.ty); - let source_var = Ident::new("source", span); - let body = from_initializer(from_field, backtrace_field, &source_var); - let from_function = quote! { - fn from(#source_var: #from) -> Self { - #ty::#variant #body - } - }; - let from_impl = quote_spanned! {span=> - #[automatically_derived] - impl #impl_generics ::core::convert::From<#from> for #ty #ty_generics #where_clause { - #from_function - } - }; - Some(quote! { - #[allow( - deprecated, - unused_qualifications, - clippy::elidable_lifetime_names, - clippy::needless_lifetimes, - )] - #from_impl - }) - }); - - if input.generics.type_params().next().is_some() { - let self_token = <Token![Self]>::default(); - error_inferred_bounds.insert(self_token, Trait::Debug); - error_inferred_bounds.insert(self_token, Trait::Display); - } - let error_where_clause = error_inferred_bounds.augment_where_clause(input.generics); - - quote! { - #[allow(unused_qualifications)] - #[automatically_derived] - impl #impl_generics ::thiserror::__private::Error for #ty #ty_generics #error_where_clause { - #source_method - #provide_method - } - #display_impl - #(#from_impls)* - } -} - -// Create an ident with which we can expand `impl Trait for #ident {}` on a -// deprecated type without triggering deprecation warning on the generated impl. -pub(crate) fn call_site_ident(ident: &Ident) -> Ident { - let mut ident = ident.clone(); - ident.set_span(ident.span().resolved_at(Span::call_site())); - ident -} - -fn fields_pat(fields: &[Field]) -> TokenStream { - let mut members = fields.iter().map(|field| &field.member).peekable(); - match members.peek() { - Some(MemberUnraw::Named(_)) => quote!({ #(#members),* }), - Some(MemberUnraw::Unnamed(_)) => { - let vars = members.map(|member| match member { - MemberUnraw::Unnamed(index) => format_ident!("_{}", index), - MemberUnraw::Named(_) => unreachable!(), - }); - quote!((#(#vars),*)) - } - None => quote!({}), - } -} - -fn use_as_display(needs_as_display: bool) -> Option<TokenStream> { - if needs_as_display { - Some(quote! { - use ::thiserror::__private::AsDisplay as _; - }) - } else { - None - } -} - -fn from_initializer( - from_field: &Field, - backtrace_field: Option<&Field>, - source_var: &Ident, -) -> TokenStream { - let from_member = &from_field.member; - let some_source = if type_is_option(from_field.ty) { - quote!(::core::option::Option::Some(#source_var)) - } else { - quote!(#source_var) - }; - let backtrace = backtrace_field.map(|backtrace_field| { - let backtrace_member = &backtrace_field.member; - if type_is_option(backtrace_field.ty) { - quote! { - #backtrace_member: ::core::option::Option::Some(::thiserror::__private::Backtrace::capture()), - } - } else { - quote! { - #backtrace_member: ::core::convert::From::from(::thiserror::__private::Backtrace::capture()), - } - } - }); - quote!({ - #from_member: #some_source, - #backtrace - }) -} - -fn type_is_option(ty: &Type) -> bool { - type_parameter_of_option(ty).is_some() -} - -fn unoptional_type(ty: &Type) -> TokenStream { - let unoptional = type_parameter_of_option(ty).unwrap_or(ty); - quote!(#unoptional) -} - -fn type_parameter_of_option(ty: &Type) -> Option<&Type> { - let path = match ty { - Type::Path(ty) => &ty.path, - _ => return None, - }; - - let last = path.segments.last().unwrap(); - if last.ident != "Option" { - return None; - } - - let bracketed = match &last.arguments { - PathArguments::AngleBracketed(bracketed) => bracketed, - _ => return None, - }; - - if bracketed.args.len() != 1 { - return None; - } - - match &bracketed.args[0] { - GenericArgument::Type(arg) => Some(arg), - _ => None, - } -} |