Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

1 files changed, 562 insertions, 0 deletions

diff --git a/vendor/thiserror-impl/src/expand.rs b/vendor/thiserror-impl/src/expand.rs
new file mode 100644
index 0000000..1b44513
--- /dev/null
+++ b/vendor/thiserror-impl/src/expand.rs
@@ -0,0 +1,562 @@
+use crate::ast::{Enum, Field, Input, Struct};
+use crate::attr::Trait;
+use crate::generics::InferredBounds;
+use crate::span::MemberSpan;
+use proc_macro2::TokenStream;
+use quote::{format_ident, quote, quote_spanned, ToTokens};
+use std::collections::BTreeSet as Set;
+use syn::{DeriveInput, GenericArgument, Member, 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 knock-on errors in other code that uses
+        // this type as an Error.
+        Err(error) => fallback(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 fallback(input: &DeriveInput, error: syn::Error) -> TokenStream {
+    let ty = &input.ident;
+    let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
+
+    let error = error.to_compile_error();
+
+    quote! {
+        #error
+
+        #[allow(unused_qualifications)]
+        impl #impl_generics std::error::Error for #ty #ty_generics #where_clause
+        where
+            // Work around trivial bounds being unstable.
+            // https://github.com/rust-lang/rust/issues/48214
+            for<'workaround> #ty #ty_generics: ::core::fmt::Debug,
+        {}
+
+        #[allow(unused_qualifications)]
+        impl #impl_generics ::core::fmt::Display for #ty #ty_generics #where_clause {
+            fn fmt(&self, __formatter: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
+                ::core::unreachable!()
+            }
+        }
+    }
+}
+
+fn impl_struct(input: Struct) -> TokenStream {
+    let ty = &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!(std::error::Error));
+        }
+        let member = &only_field.member;
+        Some(quote_spanned! {transparent_attr.span=>
+            std::error::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!(std::error::Error + 'static));
+        }
+        let asref = if type_is_option(source_field.ty) {
+            Some(quote_spanned!(source.member_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 std::error::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.member_span()=>
+                    if let ::core::option::Option::Some(source) = &self.#source {
+                        source.thiserror_provide(#request);
+                    }
+                }
+            } else {
+                quote_spanned! {source.member_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::<std::backtrace::Backtrace>(backtrace);
+                    }
+                })
+            } else {
+                Some(quote! {
+                    #request.provide_ref::<std::backtrace::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::<std::backtrace::Backtrace>(backtrace);
+                }
+            }
+        } else {
+            quote! {
+                #request.provide_ref::<std::backtrace::Backtrace>(&self.#backtrace);
+            }
+        };
+        quote! {
+            fn provide<'_request>(&'_request self, #request: &mut std::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 = display.implied_bounds.clone();
+        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)]
+            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 backtrace_field = input.distinct_backtrace_field();
+        let from = unoptional_type(from_field.ty);
+        let body = from_initializer(from_field, backtrace_field);
+        quote! {
+            #[allow(unused_qualifications)]
+            impl #impl_generics ::core::convert::From<#from> for #ty #ty_generics #where_clause {
+                #[allow(deprecated)]
+                fn from(source: #from) -> Self {
+                    #ty #body
+                }
+            }
+        }
+    });
+
+    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)]
+        impl #impl_generics std::error::Error for #ty #ty_generics #error_where_clause {
+            #source_method
+            #provide_method
+        }
+        #display_impl
+        #from_impl
+    }
+}
+
+fn impl_enum(input: Enum) -> TokenStream {
+    let ty = &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!(std::error::Error));
+                }
+                let member = &only_field.member;
+                let source = quote_spanned! {transparent_attr.span=>
+                    std::error::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!(std::error::Error + 'static));
+                }
+                let asref = if type_is_option(source_field.ty) {
+                    Some(quote_spanned!(source.member_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 std::error::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.member_span()=>
+                            if let ::core::option::Option::Some(source) = #varsource {
+                                source.thiserror_provide(#request);
+                            }
+                        }
+                    } else {
+                        quote_spanned! {source.member_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::<std::backtrace::Backtrace>(backtrace);
+                            }
+                        }
+                    } else {
+                        quote! {
+                            #request.provide_ref::<std::backtrace::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.member_span()=>
+                            if let ::core::option::Option::Some(source) = #varsource {
+                                source.thiserror_provide(#request);
+                            }
+                        }
+                    } else {
+                        quote_spanned! {backtrace.member_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::<std::backtrace::Backtrace>(backtrace);
+                            }
+                        }
+                    } else {
+                        quote! {
+                            #request.provide_ref::<std::backtrace::Backtrace>(backtrace);
+                        }
+                    };
+                    quote! {
+                        #ty::#ident {#backtrace: backtrace, ..} => {
+                            #body
+                        }
+                    }
+                }
+                (None, _) => quote! {
+                    #ty::#ident {..} => {}
+                },
+            }
+        });
+        Some(quote! {
+            fn provide<'_request>(&'_request self, #request: &mut std::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 = match &variant.attrs.display {
+                Some(display) => {
+                    display_implied_bounds = display.implied_bounds.clone();
+                    display.to_token_stream()
+                }
+                None => {
+                    let only_field = match &variant.fields[0].member {
+                        Member::Named(ident) => ident.clone(),
+                        Member::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)]
+            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 backtrace_field = variant.distinct_backtrace_field();
+        let variant = &variant.ident;
+        let from = unoptional_type(from_field.ty);
+        let body = from_initializer(from_field, backtrace_field);
+        Some(quote! {
+            #[allow(unused_qualifications)]
+            impl #impl_generics ::core::convert::From<#from> for #ty #ty_generics #where_clause {
+                #[allow(deprecated)]
+                fn from(source: #from) -> Self {
+                    #ty::#variant #body
+                }
+            }
+        })
+    });
+
+    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)]
+        impl #impl_generics std::error::Error for #ty #ty_generics #error_where_clause {
+            #source_method
+            #provide_method
+        }
+        #display_impl
+        #(#from_impls)*
+    }
+}
+
+fn fields_pat(fields: &[Field]) -> TokenStream {
+    let mut members = fields.iter().map(|field| &field.member).peekable();
+    match members.peek() {
+        Some(Member::Named(_)) => quote!({ #(#members),* }),
+        Some(Member::Unnamed(_)) => {
+            let vars = members.map(|member| match member {
+                Member::Unnamed(member) => format_ident!("_{}", member),
+                Member::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>) -> TokenStream {
+    let from_member = &from_field.member;
+    let some_source = if type_is_option(from_field.ty) {
+        quote!(::core::option::Option::Some(source))
+    } else {
+        quote!(source)
+    };
+    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(std::backtrace::Backtrace::capture()),
+            }
+        } else {
+            quote! {
+                #backtrace_member: ::core::convert::From::from(std::backtrace::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,
+    }
+}