use syn::spanned::Spanned;
use quote::ToTokens;
mod keyword {
syn::custom_keyword!(I);
syn::custom_keyword!(compact);
syn::custom_keyword!(GenesisBuild);
syn::custom_keyword!(Config);
syn::custom_keyword!(T);
syn::custom_keyword!(Pallet);
syn::custom_keyword!(origin);
}
#[derive(Clone)]
pub struct InstanceUsage {
pub has_instance: bool,
pub span: proc_macro2::Span,
}
pub trait MutItemAttrs {
fn mut_item_attrs(&mut self) -> Option<&mut Vec<syn::Attribute>>;
}
pub fn take_first_item_attr<Attr>(item: &mut impl MutItemAttrs) -> syn::Result<Option<Attr>> where
Attr: syn::parse::Parse,
{
let attrs = if let Some(attrs) = item.mut_item_attrs() {
attrs
} else {
return Ok(None)
};
if let Some(index) = attrs.iter()
.position(|attr|
attr.path.segments.first().map_or(false, |segment| segment.ident == "pallet")
)
{
let pallet_attr = attrs.remove(index);
Ok(Some(syn::parse2(pallet_attr.into_token_stream())?))
} else {
Ok(None)
}
}
pub fn take_item_attrs<Attr>(item: &mut impl MutItemAttrs) -> syn::Result<Vec<Attr>> where
Attr: syn::parse::Parse,
{
let mut pallet_attrs = Vec::new();
while let Some(attr) = take_first_item_attr(item)? {
pallet_attrs.push(attr)
}
Ok(pallet_attrs)
}
impl MutItemAttrs for syn::Item {
fn mut_item_attrs(&mut self) -> Option<&mut Vec<syn::Attribute>> {
match self {
Self::Const(item) => Some(item.attrs.as_mut()),
Self::Enum(item) => Some(item.attrs.as_mut()),
Self::ExternCrate(item) => Some(item.attrs.as_mut()),
Self::Fn(item) => Some(item.attrs.as_mut()),
Self::ForeignMod(item) => Some(item.attrs.as_mut()),
Self::Impl(item) => Some(item.attrs.as_mut()),
Self::Macro(item) => Some(item.attrs.as_mut()),
Self::Macro2(item) => Some(item.attrs.as_mut()),
Self::Mod(item) => Some(item.attrs.as_mut()),
Self::Static(item) => Some(item.attrs.as_mut()),
Self::Struct(item) => Some(item.attrs.as_mut()),
Self::Trait(item) => Some(item.attrs.as_mut()),
Self::TraitAlias(item) => Some(item.attrs.as_mut()),
Self::Type(item) => Some(item.attrs.as_mut()),
Self::Union(item) => Some(item.attrs.as_mut()),
Self::Use(item) => Some(item.attrs.as_mut()),
_ => None,
}
}
}
impl MutItemAttrs for syn::TraitItem {
fn mut_item_attrs(&mut self) -> Option<&mut Vec<syn::Attribute>> {
match self {
Self::Const(item) => Some(item.attrs.as_mut()),
Self::Method(item) => Some(item.attrs.as_mut()),
Self::Type(item) => Some(item.attrs.as_mut()),
Self::Macro(item) => Some(item.attrs.as_mut()),
_ => None,
}
}
}
impl MutItemAttrs for Vec<syn::Attribute> {
fn mut_item_attrs(&mut self) -> Option<&mut Vec<syn::Attribute>> {
Some(self)
}
}
impl MutItemAttrs for syn::ItemMod {
fn mut_item_attrs(&mut self) -> Option<&mut Vec<syn::Attribute>> {
Some(&mut self.attrs)
}
}
pub fn get_doc_literals(attrs: &Vec<syn::Attribute>) -> Vec<syn::Lit> {
attrs.iter()
.filter_map(|attr| {
if let Ok(syn::Meta::NameValue(meta)) = attr.parse_meta() {
if meta.path.get_ident().map_or(false, |ident| ident == "doc") {
Some(meta.lit)
} else {
None
}
} else {
None
}
})
.collect()
}
struct Unit;
impl syn::parse::Parse for Unit {
fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
let content;
syn::parenthesized!(content in input);
if !content.is_empty() {
let msg = "unexpected tokens, expected nothing inside parenthesis as `()`";
return Err(syn::Error::new(content.span(), msg));
}
Ok(Self)
}
}
struct StaticLifetime;
impl syn::parse::Parse for StaticLifetime {
fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
let lifetime = input.parse::<syn::Lifetime>()?;
if lifetime.ident != "static" {
let msg = "unexpected tokens, expected `static`";
return Err(syn::Error::new(lifetime.ident.span(), msg));
}
Ok(Self)
}
}
pub fn check_config_def_gen(
gen: &syn::Generics,
span: proc_macro2::Span,
) -> syn::Result<()> {
let expected = "expected `I: 'static = ()`";
pub struct CheckTraitDefGenerics;
impl syn::parse::Parse for CheckTraitDefGenerics {
fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
input.parse::<keyword::I>()?;
input.parse::<syn::Token![:]>()?;
input.parse::<StaticLifetime>()?;
input.parse::<syn::Token![=]>()?;
input.parse::<Unit>()?;
Ok(Self)
}
}
syn::parse2::<CheckTraitDefGenerics>(gen.params.to_token_stream())
.map_err(|e| {
let msg = format!("Invalid generics: {}", expected);
let mut err = syn::Error::new(span, msg);
err.combine(e);
err
})?;
Ok(())
}
pub fn check_type_def_gen_no_bounds(
gen: &syn::Generics,
span: proc_macro2::Span,
) -> syn::Result<InstanceUsage> {
let expected = "expected `T` or `T, I = ()`";
pub struct Checker(InstanceUsage);
impl syn::parse::Parse for Checker {
fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
let mut instance_usage = InstanceUsage {
has_instance: false,
span: input.span(),
};
input.parse::<keyword::T>()?;
if input.peek(syn::Token![,]) {
instance_usage.has_instance = true;
input.parse::<syn::Token![,]>()?;
input.parse::<keyword::I>()?;
input.parse::<syn::Token![=]>()?;
input.parse::<Unit>()?;
}
Ok(Self(instance_usage))
}
}
let i = syn::parse2::<Checker>(gen.params.to_token_stream())
.map_err(|e| {
let msg = format!("Invalid type def generics: {}", expected);
let mut err = syn::Error::new(span, msg);
err.combine(e);
err
})?.0;
Ok(i)
}
pub fn check_type_def_optional_gen(
gen: &syn::Generics,
span: proc_macro2::Span,
) -> syn::Result<Option<InstanceUsage>> {
let expected = "expected `` or `T` or `T: Config` or `T, I = ()` or \
`T: Config<I>, I: 'static = ()`";
pub struct Checker(Option<InstanceUsage>);
impl syn::parse::Parse for Checker {
fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
if input.is_empty() {
return Ok(Self(None))
}
let mut instance_usage = InstanceUsage {
span: input.span(),
has_instance: false,
};
input.parse::<keyword::T>()?;
if input.is_empty() {
return Ok(Self(Some(instance_usage)))
}
let lookahead = input.lookahead1();
if lookahead.peek(syn::Token![,]) {
instance_usage.has_instance = true;
input.parse::<syn::Token![,]>()?;
input.parse::<keyword::I>()?;
input.parse::<syn::Token![=]>()?;
input.parse::<Unit>()?;
Ok(Self(Some(instance_usage)))
} else if lookahead.peek(syn::Token![:]) {
input.parse::<syn::Token![:]>()?;
input.parse::<keyword::Config>()?;
if input.is_empty() {
return Ok(Self(Some(instance_usage)))
}
instance_usage.has_instance = true;
input.parse::<syn::Token![<]>()?;
input.parse::<keyword::I>()?;
input.parse::<syn::Token![>]>()?;
input.parse::<syn::Token![,]>()?;
input.parse::<keyword::I>()?;
input.parse::<syn::Token![:]>()?;
input.parse::<StaticLifetime>()?;
input.parse::<syn::Token![=]>()?;
input.parse::<Unit>()?;
Ok(Self(Some(instance_usage)))
} else {
Err(lookahead.error())
}
}
}
let i = syn::parse2::<Checker>(gen.params.to_token_stream())
.map_err(|e| {
let msg = format!("Invalid type def generics: {}", expected);
let mut err = syn::Error::new(span, msg);
err.combine(e);
err
})?.0
.map(|mut i| { i.span = span; i });
Ok(i)
}
pub fn check_pallet_struct_usage(type_: &Box<syn::Type>) -> syn::Result<InstanceUsage> {
let expected = "expected `Pallet<T>` or `Pallet<T, I>`";
pub struct Checker(InstanceUsage);
impl syn::parse::Parse for Checker {
fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
let mut instance_usage = InstanceUsage {
span: input.span(),
has_instance: false,
};
input.parse::<keyword::Pallet>()?;
input.parse::<syn::Token![<]>()?;
input.parse::<keyword::T>()?;
if input.peek(syn::Token![,]) {
instance_usage.has_instance = true;
input.parse::<syn::Token![,]>()?;
input.parse::<keyword::I>()?;
}
input.parse::<syn::Token![>]>()?;
Ok(Self(instance_usage))
}
}
let i = syn::parse2::<Checker>(type_.to_token_stream())
.map_err(|e| {
let msg = format!("Invalid pallet struct: {}", expected);
let mut err = syn::Error::new(type_.span(), msg);
err.combine(e);
err
})?.0;
Ok(i)
}
pub fn check_impl_gen(
gen: &syn::Generics,
span: proc_macro2::Span
) -> syn::Result<InstanceUsage> {
let expected = "expected `impl<T: Config>` or `impl<T: Config<I>, I: 'static>`";
pub struct Checker(InstanceUsage);
impl syn::parse::Parse for Checker {
fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
let mut instance_usage = InstanceUsage {
span: input.span(),
has_instance: false,
};
input.parse::<keyword::T>()?;
input.parse::<syn::Token![:]>()?;
input.parse::<keyword::Config>()?;
if input.peek(syn::Token![<]) {
instance_usage.has_instance = true;
input.parse::<syn::Token![<]>()?;
input.parse::<keyword::I>()?;
input.parse::<syn::Token![>]>()?;
input.parse::<syn::Token![,]>()?;
input.parse::<keyword::I>()?;
input.parse::<syn::Token![:]>()?;
input.parse::<StaticLifetime>()?;
}
Ok(Self(instance_usage))
}
}
let i = syn::parse2::<Checker>(gen.params.to_token_stream())
.map_err(|e| {
let mut err = syn::Error::new(span, format!("Invalid generics: {}", expected));
err.combine(e);
err
})?.0;
Ok(i)
}
pub fn check_type_def_gen(
gen: &syn::Generics,
span: proc_macro2::Span,
) -> syn::Result<InstanceUsage> {
let expected = "expected `T` or `T: Config` or `T, I = ()` or \
`T: Config<I>, I: 'static = ()`";
pub struct Checker(InstanceUsage);
impl syn::parse::Parse for Checker {
fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
let mut instance_usage = InstanceUsage {
span: input.span(),
has_instance: false,
};
input.parse::<keyword::T>()?;
if input.is_empty() {
return Ok(Self(instance_usage))
}
let lookahead = input.lookahead1();
if lookahead.peek(syn::Token![,]) {
instance_usage.has_instance = true;
input.parse::<syn::Token![,]>()?;
input.parse::<keyword::I>()?;
input.parse::<syn::Token![=]>()?;
input.parse::<Unit>()?;
Ok(Self(instance_usage))
} else if lookahead.peek(syn::Token![:]) {
input.parse::<syn::Token![:]>()?;
input.parse::<keyword::Config>()?;
if input.is_empty() {
return Ok(Self(instance_usage))
}
instance_usage.has_instance = true;
input.parse::<syn::Token![<]>()?;
input.parse::<keyword::I>()?;
input.parse::<syn::Token![>]>()?;
input.parse::<syn::Token![,]>()?;
input.parse::<keyword::I>()?;
input.parse::<syn::Token![:]>()?;
input.parse::<StaticLifetime>()?;
input.parse::<syn::Token![=]>()?;
input.parse::<Unit>()?;
Ok(Self(instance_usage))
} else {
Err(lookahead.error())
}
}
}
let mut i = syn::parse2::<Checker>(gen.params.to_token_stream())
.map_err(|e| {
let msg = format!("Invalid type def generics: {}", expected);
let mut err = syn::Error::new(span, msg);
err.combine(e);
err
})?.0;
i.span = span;
Ok(i)
}
pub fn check_genesis_builder_usage(type_: &syn::Path) -> syn::Result<InstanceUsage> {
let expected = "expected `GenesisBuild<T>` or `GenesisBuild<T, I>`";
pub struct Checker(InstanceUsage);
impl syn::parse::Parse for Checker {
fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
let mut instance_usage = InstanceUsage {
span: input.span(),
has_instance: false,
};
input.parse::<keyword::GenesisBuild>()?;
input.parse::<syn::Token![<]>()?;
input.parse::<keyword::T>()?;
if input.peek(syn::Token![,]) {
instance_usage.has_instance = true;
input.parse::<syn::Token![,]>()?;
input.parse::<keyword::I>()?;
}
input.parse::<syn::Token![>]>()?;
Ok(Self(instance_usage))
}
}
let i = syn::parse2::<Checker>(type_.to_token_stream())
.map_err(|e| {
let msg = format!("Invalid genesis builder: {}", expected);
let mut err = syn::Error::new(type_.span(), msg);
err.combine(e);
err
})?.0;
Ok(i)
}
pub fn check_type_value_gen(
gen: &syn::Generics,
span: proc_macro2::Span,
) -> syn::Result<Option<InstanceUsage>> {
let expected = "expected `` or `T: Config` or `T: Config<I>, I: 'static`";
pub struct Checker(Option<InstanceUsage>);
impl syn::parse::Parse for Checker {
fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
if input.is_empty() {
return Ok(Self(None))
}
input.parse::<keyword::T>()?;
input.parse::<syn::Token![:]>()?;
input.parse::<keyword::Config>()?;
let mut instance_usage = InstanceUsage {
span: input.span(),
has_instance: false,
};
if input.is_empty() {
return Ok(Self(Some(instance_usage)))
}
instance_usage.has_instance = true;
input.parse::<syn::Token![<]>()?;
input.parse::<keyword::I>()?;
input.parse::<syn::Token![>]>()?;
input.parse::<syn::Token![,]>()?;
input.parse::<keyword::I>()?;
input.parse::<syn::Token![:]>()?;
input.parse::<StaticLifetime>()?;
Ok(Self(Some(instance_usage)))
}
}
let i = syn::parse2::<Checker>(gen.params.to_token_stream())
.map_err(|e| {
let msg = format!("Invalid type def generics: {}", expected);
let mut err = syn::Error::new(span, msg);
err.combine(e);
err
})?.0
.map(|mut i| { i.span = span; i });
Ok(i)
}