Merge commit '6eba9cd92c295c5389944f6adda1f1e83b2cb008' as 'subprojects/thiserror'

subprojects/thiserror/impl/src/ast.rs

@@ -0,0 +1,185 @@
+use crate::attr::{self, Attrs};
+use crate::generics::ParamsInScope;
+use crate::unraw::{IdentUnraw, MemberUnraw};
+use proc_macro2::Span;
+use std::fmt::{self, Display};
+use syn::{
+    Data, DataEnum, DataStruct, DeriveInput, Error, Fields, Generics, Ident, Index, Result, Type,
+};
+
+pub enum Input<'a> {
+    Struct(Struct<'a>),
+    Enum(Enum<'a>),
+}
+
+pub struct Struct<'a> {
+    pub attrs: Attrs<'a>,
+    pub ident: Ident,
+    pub generics: &'a Generics,
+    pub fields: Vec<Field<'a>>,
+}
+
+pub struct Enum<'a> {
+    pub attrs: Attrs<'a>,
+    pub ident: Ident,
+    pub generics: &'a Generics,
+    pub variants: Vec<Variant<'a>>,
+}
+
+pub struct Variant<'a> {
+    pub original: &'a syn::Variant,
+    pub attrs: Attrs<'a>,
+    pub ident: Ident,
+    pub fields: Vec<Field<'a>>,
+}
+
+pub struct Field<'a> {
+    pub original: &'a syn::Field,
+    pub attrs: Attrs<'a>,
+    pub member: MemberUnraw,
+    pub ty: &'a Type,
+    pub contains_generic: bool,
+}
+
+#[derive(Copy, Clone)]
+pub enum ContainerKind {
+    Struct,
+    TupleStruct,
+    UnitStruct,
+    StructVariant,
+    TupleVariant,
+    UnitVariant,
+}
+
+impl<'a> Input<'a> {
+    pub fn from_syn(node: &'a DeriveInput) -> Result<Self> {
+        match &node.data {
+            Data::Struct(data) => Struct::from_syn(node, data).map(Input::Struct),
+            Data::Enum(data) => Enum::from_syn(node, data).map(Input::Enum),
+            Data::Union(_) => Err(Error::new_spanned(
+                node,
+                "union as errors are not supported",
+            )),
+        }
+    }
+}
+
+impl<'a> Struct<'a> {
+    fn from_syn(node: &'a DeriveInput, data: &'a DataStruct) -> Result<Self> {
+        let mut attrs = attr::get(&node.attrs)?;
+        let scope = ParamsInScope::new(&node.generics);
+        let fields = Field::multiple_from_syn(&data.fields, &scope)?;
+        if let Some(display) = &mut attrs.display {
+            let container = ContainerKind::from_struct(data);
+            display.expand_shorthand(&fields, container)?;
+        }
+        Ok(Struct {
+            attrs,
+            ident: node.ident.clone(),
+            generics: &node.generics,
+            fields,
+        })
+    }
+}
+
+impl<'a> Enum<'a> {
+    fn from_syn(node: &'a DeriveInput, data: &'a DataEnum) -> Result<Self> {
+        let attrs = attr::get(&node.attrs)?;
+        let scope = ParamsInScope::new(&node.generics);
+        let variants = data
+            .variants
+            .iter()
+            .map(|node| {
+                let mut variant = Variant::from_syn(node, &scope)?;
+                if variant.attrs.display.is_none()
+                    && variant.attrs.transparent.is_none()
+                    && variant.attrs.fmt.is_none()
+                {
+                    variant.attrs.display.clone_from(&attrs.display);
+                    variant.attrs.transparent = attrs.transparent;
+                    variant.attrs.fmt.clone_from(&attrs.fmt);
+                }
+                if let Some(display) = &mut variant.attrs.display {
+                    let container = ContainerKind::from_variant(node);
+                    display.expand_shorthand(&variant.fields, container)?;
+                }
+                Ok(variant)
+            })
+            .collect::<Result<_>>()?;
+        Ok(Enum {
+            attrs,
+            ident: node.ident.clone(),
+            generics: &node.generics,
+            variants,
+        })
+    }
+}
+
+impl<'a> Variant<'a> {
+    fn from_syn(node: &'a syn::Variant, scope: &ParamsInScope<'a>) -> Result<Self> {
+        let attrs = attr::get(&node.attrs)?;
+        Ok(Variant {
+            original: node,
+            attrs,
+            ident: node.ident.clone(),
+            fields: Field::multiple_from_syn(&node.fields, scope)?,
+        })
+    }
+}
+
+impl<'a> Field<'a> {
+    fn multiple_from_syn(fields: &'a Fields, scope: &ParamsInScope<'a>) -> Result<Vec<Self>> {
+        fields
+            .iter()
+            .enumerate()
+            .map(|(i, field)| Field::from_syn(i, field, scope))
+            .collect()
+    }
+
+    fn from_syn(i: usize, node: &'a syn::Field, scope: &ParamsInScope<'a>) -> Result<Self> {
+        Ok(Field {
+            original: node,
+            attrs: attr::get(&node.attrs)?,
+            member: match &node.ident {
+                Some(name) => MemberUnraw::Named(IdentUnraw::new(name.clone())),
+                None => MemberUnraw::Unnamed(Index {
+                    index: i as u32,
+                    span: Span::call_site(),
+                }),
+            },
+            ty: &node.ty,
+            contains_generic: scope.intersects(&node.ty),
+        })
+    }
+}
+
+impl ContainerKind {
+    fn from_struct(node: &DataStruct) -> Self {
+        match node.fields {
+            Fields::Named(_) => ContainerKind::Struct,
+            Fields::Unnamed(_) => ContainerKind::TupleStruct,
+            Fields::Unit => ContainerKind::UnitStruct,
+        }
+    }
+
+    fn from_variant(node: &syn::Variant) -> Self {
+        match node.fields {
+            Fields::Named(_) => ContainerKind::StructVariant,
+            Fields::Unnamed(_) => ContainerKind::TupleVariant,
+            Fields::Unit => ContainerKind::UnitVariant,
+        }
+    }
+}
+
+impl Display for ContainerKind {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str(match self {
+            ContainerKind::Struct => "struct",
+            ContainerKind::TupleStruct => "tuple struct",
+            ContainerKind::UnitStruct => "unit struct",
+            ContainerKind::StructVariant => "struct variant",
+            ContainerKind::TupleVariant => "tuple variant",
+            ContainerKind::UnitVariant => "unit variant",
+        })
+    }
+}