feat: initialize Kurdistan SDK - independent fork of Polkadot SDK

pezkuwi/xcm/procedural/src/builder_pattern.rs

@@ -0,0 +1,456 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Pezkuwi is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Derive macro for creating XCMs with a builder pattern
+
+use inflector::Inflector;
+use proc_macro2::TokenStream as TokenStream2;
+use quote::{format_ident, quote};
+use syn::{
+	Data, DataEnum, DeriveInput, Error, Expr, ExprLit, Field, Fields, GenericArgument, Ident, Lit,
+	Meta, MetaNameValue, PathArguments, Result, Type, TypePath, Variant,
+};
+
+pub fn derive(input: DeriveInput) -> Result<TokenStream2> {
+	let data_enum = match &input.data {
+		Data::Enum(data_enum) => data_enum,
+		_ => return Err(Error::new_spanned(&input, "Expected the `Instruction` enum")),
+	};
+	let builder_raw_impl = generate_builder_raw_impl(&input.ident, data_enum)?;
+	let builder_impl = generate_builder_impl(&input.ident, data_enum)?;
+	let builder_unpaid_impl = generate_builder_unpaid_impl(&input.ident, data_enum)?;
+	let output = quote! {
+		/// A trait for types that track state inside the XcmBuilder
+		pub trait XcmBuilderState {}
+
+		/// Access to all the instructions
+		pub enum AnythingGoes {}
+		/// You need to pay for execution
+		pub enum PaymentRequired {}
+		/// The holding register was loaded, now to buy execution
+		pub enum LoadedHolding {}
+		/// Need to explicitly state it won't pay for fees
+		pub enum ExplicitUnpaidRequired {}
+
+		impl XcmBuilderState for AnythingGoes {}
+		impl XcmBuilderState for PaymentRequired {}
+		impl XcmBuilderState for LoadedHolding {}
+		impl XcmBuilderState for ExplicitUnpaidRequired {}
+
+		/// Type used to build XCM programs
+		pub struct XcmBuilder<Call, S: XcmBuilderState> {
+			pub(crate) instructions: Vec<Instruction<Call>>,
+			pub state: core::marker::PhantomData<S>,
+		}
+
+		impl<Call> Xcm<Call> {
+			pub fn builder() -> XcmBuilder<Call, PaymentRequired> {
+				XcmBuilder::<Call, PaymentRequired> {
+					instructions: Vec::new(),
+					state: core::marker::PhantomData,
+				}
+			}
+			pub fn builder_unpaid() -> XcmBuilder<Call, ExplicitUnpaidRequired> {
+				XcmBuilder::<Call, ExplicitUnpaidRequired> {
+					instructions: Vec::new(),
+					state: core::marker::PhantomData,
+				}
+			}
+			pub fn builder_unsafe() -> XcmBuilder<Call, AnythingGoes> {
+				XcmBuilder::<Call, AnythingGoes> {
+					instructions: Vec::new(),
+					state: core::marker::PhantomData,
+				}
+			}
+		}
+		#builder_impl
+		#builder_unpaid_impl
+		#builder_raw_impl
+	};
+	Ok(output)
+}
+
+fn generate_builder_raw_impl(name: &Ident, data_enum: &DataEnum) -> Result<TokenStream2> {
+	let methods = data_enum
+		.variants
+		.iter()
+		.map(|variant| convert_variant_to_method(name, variant, None))
+		.collect::<Result<Vec<_>>>()?;
+	let output = quote! {
+		impl<Call> XcmBuilder<Call, AnythingGoes> {
+			#(#methods)*
+
+			pub fn build(self) -> Xcm<Call> {
+				Xcm(self.instructions)
+			}
+		}
+	};
+	Ok(output)
+}
+
+fn generate_builder_impl(name: &Ident, data_enum: &DataEnum) -> Result<TokenStream2> {
+	// We first require an instruction that load the holding register
+	let load_holding_variants = data_enum
+		.variants
+		.iter()
+		.map(|variant| {
+			let maybe_builder_attr = variant.attrs.iter().find(|attr| match attr.meta {
+				Meta::List(ref list) => list.path.is_ident("builder"),
+				_ => false,
+			});
+			let builder_attr = match maybe_builder_attr {
+				Some(builder) => builder.clone(),
+				None => return Ok(None), /* It's not going to be an instruction that loads the
+				                          * holding register */
+			};
+			let Meta::List(ref list) = builder_attr.meta else { unreachable!("We checked before") };
+			let inner_ident: Ident = syn::parse2(list.tokens.clone()).map_err(|_| {
+				Error::new_spanned(
+					&builder_attr,
+					"Expected `builder(loads_holding)` or `builder(pays_fees)`",
+				)
+			})?;
+			let loads_holding_ident: Ident = syn::parse_quote!(loads_holding);
+			let pays_fees_ident: Ident = syn::parse_quote!(pays_fees);
+			if inner_ident == loads_holding_ident {
+				Ok(Some(variant))
+			} else if inner_ident == pays_fees_ident {
+				Ok(None)
+			} else {
+				Err(Error::new_spanned(
+					&builder_attr,
+					"Expected `builder(loads_holding)` or `builder(pays_fees)`",
+				))
+			}
+		})
+		.collect::<Result<Vec<_>>>()?;
+
+	let load_holding_methods = load_holding_variants
+		.into_iter()
+		.flatten()
+		.map(|variant| {
+			let method = convert_variant_to_method(
+				name,
+				variant,
+				Some(quote! { XcmBuilder<Call, LoadedHolding> }),
+			)?;
+			Ok(method)
+		})
+		.collect::<Result<Vec<_>>>()?;
+
+	let first_impl = quote! {
+		impl<Call> XcmBuilder<Call, PaymentRequired> {
+			#(#load_holding_methods)*
+		}
+	};
+
+	// Some operations are allowed after the holding register is loaded
+	let allowed_after_load_holding_methods: Vec<TokenStream2> = data_enum
+		.variants
+		.iter()
+		.filter(|variant| variant.ident == "ClearOrigin" || variant.ident == "SetHints")
+		.map(|variant| {
+			let method = convert_variant_to_method(name, variant, None)?;
+			Ok(method)
+		})
+		.collect::<Result<Vec<_>>>()?;
+
+	// Then we require fees to be paid
+	let pay_fees_variants = data_enum
+		.variants
+		.iter()
+		.map(|variant| {
+			let maybe_builder_attr = variant.attrs.iter().find(|attr| match attr.meta {
+				Meta::List(ref list) => list.path.is_ident("builder"),
+				_ => false,
+			});
+			let builder_attr = match maybe_builder_attr {
+				Some(builder) => builder.clone(),
+				None => return Ok(None), /* It's not going to be an instruction that pays fees */
+			};
+			let Meta::List(ref list) = builder_attr.meta else { unreachable!("We checked before") };
+			let inner_ident: Ident = syn::parse2(list.tokens.clone()).map_err(|_| {
+				Error::new_spanned(
+					&builder_attr,
+					"Expected `builder(loads_holding)` or `builder(pays_fees)`",
+				)
+			})?;
+			let ident_to_match: Ident = syn::parse_quote!(pays_fees);
+			if inner_ident == ident_to_match {
+				Ok(Some(variant))
+			} else {
+				Ok(None) // Must have been `loads_holding` instead.
+			}
+		})
+		.collect::<Result<Vec<_>>>()?;
+
+	let pay_fees_methods = pay_fees_variants
+		.into_iter()
+		.flatten()
+		.map(|variant| {
+			let method = convert_variant_to_method(
+				name,
+				variant,
+				Some(quote! { XcmBuilder<Call, AnythingGoes> }),
+			)?;
+			Ok(method)
+		})
+		.collect::<Result<Vec<_>>>()?;
+
+	let second_impl = quote! {
+		impl<Call> XcmBuilder<Call, LoadedHolding> {
+			#(#allowed_after_load_holding_methods)*
+			#(#pay_fees_methods)*
+		}
+	};
+
+	let output = quote! {
+		#first_impl
+		#second_impl
+	};
+
+	Ok(output)
+}
+
+fn generate_builder_unpaid_impl(name: &Ident, data_enum: &DataEnum) -> Result<TokenStream2> {
+	let unpaid_execution_variant = data_enum
+		.variants
+		.iter()
+		.find(|variant| variant.ident == "UnpaidExecution")
+		.ok_or(Error::new_spanned(&data_enum.variants, "No UnpaidExecution instruction"))?;
+	let method = convert_variant_to_method(
+		name,
+		&unpaid_execution_variant,
+		Some(quote! { XcmBuilder<Call, AnythingGoes> }),
+	)?;
+	Ok(quote! {
+		impl<Call> XcmBuilder<Call, ExplicitUnpaidRequired> {
+			#method
+		}
+	})
+}
+
+// Small helper enum to differentiate between fields that use a `BoundedVec`
+// and the rest.
+enum BoundedOrNormal {
+	Normal(Field),
+	Bounded(Field),
+}
+
+// Have to call with `XcmBuilder<Call, LoadedHolding>` in allowed_after_load_holding_methods.
+fn convert_variant_to_method(
+	name: &Ident,
+	variant: &Variant,
+	maybe_return_type: Option<TokenStream2>,
+) -> Result<TokenStream2> {
+	let variant_name = &variant.ident;
+	let method_name_string = &variant_name.to_string().to_snake_case();
+	let method_name = syn::Ident::new(method_name_string, variant_name.span());
+	let docs = get_doc_comments(variant);
+	let method = match &variant.fields {
+		Fields::Unit =>
+			if let Some(return_type) = maybe_return_type {
+				quote! {
+					pub fn #method_name(self) -> #return_type {
+						let mut new_instructions = self.instructions;
+						new_instructions.push(#name::<Call>::#variant_name);
+						XcmBuilder {
+							instructions: new_instructions,
+							state: core::marker::PhantomData,
+						}
+					}
+				}
+			} else {
+				quote! {
+					pub fn #method_name(mut self) -> Self {
+						self.instructions.push(#name::<Call>::#variant_name);
+						self
+					}
+				}
+			},
+		Fields::Unnamed(fields) => {
+			let arg_names: Vec<_> = fields
+				.unnamed
+				.iter()
+				.enumerate()
+				.map(|(index, _)| format_ident!("arg{}", index))
+				.collect();
+			let arg_types: Vec<_> = fields.unnamed.iter().map(|field| &field.ty).collect();
+			if let Some(return_type) = maybe_return_type {
+				quote! {
+					pub fn #method_name(self, #(#arg_names: impl Into<#arg_types>),*) -> #return_type {
+						let mut new_instructions = self.instructions;
+						#(let #arg_names = #arg_names.into();)*
+						new_instructions.push(#name::<Call>::#variant_name(#(#arg_names),*));
+						XcmBuilder {
+							instructions: new_instructions,
+							state: core::marker::PhantomData,
+						}
+					}
+				}
+			} else {
+				quote! {
+					pub fn #method_name(mut self, #(#arg_names: impl Into<#arg_types>),*) -> Self {
+						#(let #arg_names = #arg_names.into();)*
+						self.instructions.push(#name::<Call>::#variant_name(#(#arg_names),*));
+						self
+					}
+				}
+			}
+		},
+		Fields::Named(fields) => {
+			let fields: Vec<_> = fields
+				.named
+				.iter()
+				.map(|field| {
+					if let Type::Path(TypePath { path, .. }) = &field.ty {
+						for segment in &path.segments {
+							if segment.ident == format_ident!("BoundedVec") {
+								return BoundedOrNormal::Bounded(field.clone());
+							}
+						}
+						BoundedOrNormal::Normal(field.clone())
+					} else {
+						BoundedOrNormal::Normal(field.clone())
+					}
+				})
+				.collect();
+			let arg_names: Vec<_> = fields
+				.iter()
+				.map(|field| match field {
+					BoundedOrNormal::Bounded(field) => &field.ident,
+					BoundedOrNormal::Normal(field) => &field.ident,
+				})
+				.collect();
+			let arg_types: Vec<_> = fields
+				.iter()
+				.map(|field| match field {
+					BoundedOrNormal::Bounded(field) => {
+						let inner_type =
+							extract_generic_argument(&field.ty, 0, "BoundedVec's inner type")?;
+						Ok(quote! {
+							Vec<#inner_type>
+						})
+					},
+					BoundedOrNormal::Normal(field) => {
+						let inner_type = &field.ty;
+						Ok(quote! {
+							impl Into<#inner_type>
+						})
+					},
+				})
+				.collect::<Result<Vec<_>>>()?;
+			let bounded_names: Vec<_> = fields
+				.iter()
+				.filter_map(|field| match field {
+					BoundedOrNormal::Bounded(field) => Some(&field.ident),
+					BoundedOrNormal::Normal(_) => None,
+				})
+				.collect();
+			let normal_names: Vec<_> = fields
+				.iter()
+				.filter_map(|field| match field {
+					BoundedOrNormal::Normal(field) => Some(&field.ident),
+					BoundedOrNormal::Bounded(_) => None,
+				})
+				.collect();
+			let comma_in_the_middle = if normal_names.is_empty() {
+				quote! {}
+			} else {
+				quote! {,}
+			};
+			if let Some(return_type) = maybe_return_type {
+				quote! {
+					pub fn #method_name(self, #(#arg_names: #arg_types),*) -> #return_type {
+						let mut new_instructions = self.instructions;
+						#(let #normal_names = #normal_names.into();)*
+						#(let #bounded_names = BoundedVec::truncate_from(#bounded_names);)*
+						new_instructions.push(#name::<Call>::#variant_name { #(#normal_names),* #comma_in_the_middle #(#bounded_names),* });
+						XcmBuilder {
+							instructions: new_instructions,
+							state: core::marker::PhantomData,
+						}
+					}
+				}
+			} else {
+				quote! {
+					pub fn #method_name(mut self, #(#arg_names: #arg_types),*) -> Self {
+						#(let #normal_names = #normal_names.into();)*
+						#(let #bounded_names = BoundedVec::truncate_from(#bounded_names);)*
+						self.instructions.push(#name::<Call>::#variant_name { #(#normal_names),* #comma_in_the_middle #(#bounded_names),* });
+						self
+					}
+				}
+			}
+		},
+	};
+	Ok(quote! {
+		#(#docs)*
+		#method
+	})
+}
+
+fn get_doc_comments(variant: &Variant) -> Vec<TokenStream2> {
+	variant
+		.attrs
+		.iter()
+		.filter_map(|attr| match &attr.meta {
+			Meta::NameValue(MetaNameValue {
+				value: Expr::Lit(ExprLit { lit: Lit::Str(literal), .. }),
+				..
+			}) if attr.path().is_ident("doc") => Some(literal.value()),
+			_ => None,
+		})
+		.map(|doc| syn::parse_str::<TokenStream2>(&format!("/// {}", doc)).unwrap())
+		.collect()
+}
+
+fn extract_generic_argument<'a>(
+	field_ty: &'a Type,
+	index: usize,
+	expected_msg: &str,
+) -> Result<&'a Ident> {
+	if let Type::Path(type_path) = field_ty {
+		if let Some(segment) = type_path.path.segments.last() {
+			if let PathArguments::AngleBracketed(angle_brackets) = &segment.arguments {
+				let args: Vec<_> = angle_brackets.args.iter().collect();
+				if let Some(GenericArgument::Type(Type::Path(TypePath { path, .. }))) =
+					args.get(index)
+				{
+					return path.get_ident().ok_or_else(|| {
+						Error::new_spanned(
+							path,
+							format!("Expected an identifier for {}", expected_msg),
+						)
+					});
+				}
+				return Err(Error::new_spanned(
+					angle_brackets,
+					format!("Expected a generic argument at index {} for {}", index, expected_msg),
+				));
+			}
+			return Err(Error::new_spanned(
+				&segment.arguments,
+				format!("Expected angle-bracketed arguments for {}", expected_msg),
+			));
+		}
+		return Err(Error::new_spanned(
+			&type_path.path,
+			format!("Expected at least one path segment for {}", expected_msg),
+		));
+	}
+	Err(Error::new_spanned(field_ty, format!("Expected a path type for {}", expected_msg)))
+}

pezkuwi/xcm/procedural/src/enum_variants.rs

@@ -0,0 +1,38 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Pezkuwi is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Simple derive macro for getting the number of variants in an enum.
+
+use proc_macro2::TokenStream as TokenStream2;
+use quote::{format_ident, quote};
+use syn::{Data, DeriveInput, Error, Result};
+
+pub fn derive(input: DeriveInput) -> Result<TokenStream2> {
+	let data_enum = match &input.data {
+		Data::Enum(data_enum) => data_enum,
+		_ => return Err(Error::new_spanned(&input, "Expected an enum.")),
+	};
+	let ident = format_ident!("{}NumVariants", input.ident);
+	let number_of_variants: usize = data_enum.variants.iter().count();
+	Ok(quote! {
+		pub struct #ident;
+		impl ::frame_support::traits::Get<u32> for #ident {
+			fn get() -> u32 {
+				#number_of_variants as u32
+			}
+		}
+	})
+}

pezkuwi/xcm/procedural/src/lib.rs

@@ -0,0 +1,97 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Pezkuwi is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Procedural macros used in XCM.
+
+use proc_macro::TokenStream;
+use syn::{parse_macro_input, DeriveInput};
+
+mod builder_pattern;
+mod enum_variants;
+mod v3;
+mod v4;
+mod v5;
+mod weight_info;
+
+#[proc_macro_derive(XcmWeightInfoTrait)]
+pub fn derive_xcm_weight_info(item: TokenStream) -> TokenStream {
+	weight_info::derive(item)
+}
+
+#[proc_macro]
+pub fn impl_conversion_functions_for_multilocation_v3(input: TokenStream) -> TokenStream {
+	v3::multilocation::generate_conversion_functions(input)
+		.unwrap_or_else(syn::Error::into_compile_error)
+		.into()
+}
+
+#[proc_macro]
+pub fn impl_conversion_functions_for_junctions_v3(input: TokenStream) -> TokenStream {
+	v3::junctions::generate_conversion_functions(input)
+		.unwrap_or_else(syn::Error::into_compile_error)
+		.into()
+}
+
+#[proc_macro]
+pub fn impl_conversion_functions_for_location_v4(input: TokenStream) -> TokenStream {
+	v4::location::generate_conversion_functions(input)
+		.unwrap_or_else(syn::Error::into_compile_error)
+		.into()
+}
+
+#[proc_macro]
+pub fn impl_conversion_functions_for_junctions_v4(input: TokenStream) -> TokenStream {
+	v4::junctions::generate_conversion_functions(input)
+		.unwrap_or_else(syn::Error::into_compile_error)
+		.into()
+}
+
+#[proc_macro]
+pub fn impl_conversion_functions_for_junctions_v5(input: TokenStream) -> TokenStream {
+	v5::junctions::generate_conversion_functions(input)
+		.unwrap_or_else(syn::Error::into_compile_error)
+		.into()
+}
+
+#[proc_macro]
+pub fn impl_conversion_functions_for_location_v5(input: TokenStream) -> TokenStream {
+	v5::location::generate_conversion_functions(input)
+		.unwrap_or_else(syn::Error::into_compile_error)
+		.into()
+}
+
+/// This is called on the `Instruction` enum, not on the `Xcm` struct,
+/// and allows for the following syntax for building XCMs:
+/// let message = Xcm::builder()
+/// 	.withdraw_asset(assets)
+/// 	.buy_execution(fees, weight_limit)
+/// 	.deposit_asset(assets, beneficiary)
+/// 	.build();
+#[proc_macro_derive(Builder, attributes(builder))]
+pub fn derive_builder(input: TokenStream) -> TokenStream {
+	let input = parse_macro_input!(input as DeriveInput);
+	builder_pattern::derive(input)
+		.unwrap_or_else(syn::Error::into_compile_error)
+		.into()
+}
+
+#[proc_macro_derive(NumVariants)]
+pub fn derive_num_variants(input: TokenStream) -> TokenStream {
+	let input = parse_macro_input!(input as DeriveInput);
+	enum_variants::derive(input)
+		.unwrap_or_else(syn::Error::into_compile_error)
+		.into()
+}

pezkuwi/xcm/procedural/src/v3.rs

@@ -0,0 +1,195 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Pezkuwi is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+use proc_macro2::{Span, TokenStream};
+use quote::{format_ident, quote};
+use syn::{Result, Token};
+
+const MAX_JUNCTIONS: usize = 8;
+
+pub mod multilocation {
+	use super::*;
+
+	pub fn generate_conversion_functions(input: proc_macro::TokenStream) -> Result<TokenStream> {
+		if !input.is_empty() {
+			return Err(syn::Error::new(Span::call_site(), "No arguments expected"));
+		}
+
+		let from_tuples = generate_conversion_from_tuples(8, 8);
+
+		Ok(quote! {
+			#from_tuples
+		})
+	}
+
+	fn generate_conversion_from_tuples(max_junctions: usize, max_parents: usize) -> TokenStream {
+		let mut from_tuples = (0..=max_junctions)
+			.map(|num_junctions| {
+				let types = (0..num_junctions).map(|i| format_ident!("J{}", i)).collect::<Vec<_>>();
+				let idents =
+					(0..num_junctions).map(|i| format_ident!("j{}", i)).collect::<Vec<_>>();
+				let array_size = num_junctions;
+				let interior = if num_junctions == 0 {
+					quote!(Junctions::Here)
+				} else {
+					quote! {
+						[#(#idents .into()),*].into()
+					}
+				};
+
+				let mut from_tuple = quote! {
+					impl< #(#types : Into<Junction>,)* > From<( Ancestor, #( #types ),* )> for MultiLocation {
+						fn from( ( Ancestor(parents), #(#idents),* ): ( Ancestor, #( #types ),* ) ) -> Self {
+							MultiLocation { parents, interior: #interior }
+						}
+					}
+
+					impl From<[Junction; #array_size]> for MultiLocation {
+						fn from(j: [Junction; #array_size]) -> Self {
+							let [#(#idents),*] = j;
+							MultiLocation { parents: 0, interior: #interior }
+						}
+					}
+				};
+
+				let from_parent_tuples = (0..=max_parents).map(|cur_parents| {
+					let parents =
+						(0..cur_parents).map(|_| format_ident!("Parent")).collect::<Vec<_>>();
+					let underscores =
+						(0..cur_parents).map(|_| Token![_](Span::call_site())).collect::<Vec<_>>();
+
+					quote! {
+							impl< #(#types : Into<Junction>,)* > From<( #( #parents , )* #( #types , )* )> for MultiLocation {
+								fn from( ( #(#underscores,)* #(#idents,)* ): ( #(#parents,)* #(#types,)* ) ) -> Self {
+									Self { parents: #cur_parents as u8, interior: #interior }
+								}
+							}
+					}
+				});
+
+				from_tuple.extend(from_parent_tuples);
+				from_tuple
+			})
+			.collect::<TokenStream>();
+
+		let from_parent_junctions_tuples = (0..=max_parents).map(|cur_parents| {
+			let parents = (0..cur_parents).map(|_| format_ident!("Parent")).collect::<Vec<_>>();
+			let underscores =
+				(0..cur_parents).map(|_| Token![_](Span::call_site())).collect::<Vec<_>>();
+
+			quote! {
+				impl From<( #(#parents,)* Junctions )> for MultiLocation {
+					fn from( (#(#underscores,)* junctions): ( #(#parents,)* Junctions ) ) -> Self {
+						MultiLocation { parents: #cur_parents as u8, interior: junctions }
+					}
+				}
+			}
+		});
+		from_tuples.extend(from_parent_junctions_tuples);
+
+		quote! {
+			impl From<(Ancestor, Junctions)> for MultiLocation {
+				fn from((Ancestor(parents), interior): (Ancestor, Junctions)) -> Self {
+					MultiLocation { parents, interior }
+				}
+			}
+
+			impl From<Junction> for MultiLocation {
+				fn from(x: Junction) -> Self {
+					MultiLocation { parents: 0, interior: [x].into() }
+				}
+			}
+
+			#from_tuples
+		}
+	}
+}
+
+pub mod junctions {
+	use super::*;
+
+	pub fn generate_conversion_functions(input: proc_macro::TokenStream) -> Result<TokenStream> {
+		if !input.is_empty() {
+			return Err(syn::Error::new(Span::call_site(), "No arguments expected"));
+		}
+
+		// Support up to 8 Parents in a tuple, assuming that most use cases don't go past 8 parents.
+		let from_v4 = generate_conversion_from_v4();
+		let from_tuples = generate_conversion_from_tuples(MAX_JUNCTIONS);
+
+		Ok(quote! {
+			#from_v4
+			#from_tuples
+		})
+	}
+
+	fn generate_conversion_from_tuples(max_junctions: usize) -> TokenStream {
+		(1..=max_junctions)
+			.map(|num_junctions| {
+				let idents =
+					(0..num_junctions).map(|i| format_ident!("j{}", i)).collect::<Vec<_>>();
+				let types = (0..num_junctions).map(|i| format_ident!("J{}", i)).collect::<Vec<_>>();
+
+				quote! {
+					impl<#(#types : Into<Junction>,)*> From<( #(#types,)* )> for Junctions {
+						fn from( ( #(#idents,)* ): ( #(#types,)* ) ) -> Self {
+							[#(#idents .into()),*].into()
+						}
+					}
+				}
+			})
+			.collect()
+	}
+
+	fn generate_conversion_from_v4() -> TokenStream {
+		let match_variants = (0..8u8)
+			.map(|current_number| {
+				let number_ancestors = current_number + 1;
+				let variant = format_ident!("X{}", number_ancestors);
+				let idents =
+					(0..=current_number).map(|i| format_ident!("j{}", i)).collect::<Vec<_>>();
+				let convert = idents
+					.iter()
+					.map(|ident| {
+						quote! { let #ident = core::convert::TryInto::try_into(#ident.clone())?; }
+					})
+					.collect::<Vec<_>>();
+
+				quote! {
+					crate::v4::Junctions::#variant( junctions ) => {
+						let [#(#idents),*] = &*junctions;
+						#(#convert);*
+						[#(#idents),*].into()
+					},
+				}
+			})
+			.collect::<TokenStream>();
+
+		quote! {
+			impl core::convert::TryFrom<crate::v4::Junctions> for Junctions {
+				type Error = ();
+
+				fn try_from(mut new: crate::v4::Junctions) -> core::result::Result<Self, Self::Error> {
+					use Junctions::*;
+					Ok(match new {
+						crate::v4::Junctions::Here => Here,
+						#match_variants
+					})
+				}
+			}
+		}
+	}
+}

pezkuwi/xcm/procedural/src/v4.rs

@@ -0,0 +1,237 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Pezkuwi is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+use proc_macro2::{Span, TokenStream};
+use quote::{format_ident, quote};
+use syn::{Result, Token};
+
+const MAX_JUNCTIONS: usize = 8;
+
+pub mod location {
+	use super::*;
+
+	/// Generates conversion functions from other types to the `Location` type:
+	/// - [PalletInstance(50), GeneralIndex(1984)].into()
+	/// - (Parent, Teyrchain(1000), AccountId32 { .. }).into()
+	pub fn generate_conversion_functions(input: proc_macro::TokenStream) -> Result<TokenStream> {
+		if !input.is_empty() {
+			return Err(syn::Error::new(Span::call_site(), "No arguments expected"));
+		}
+
+		let from_tuples = generate_conversion_from_tuples(8, 8);
+
+		Ok(quote! {
+			#from_tuples
+		})
+	}
+
+	fn generate_conversion_from_tuples(max_junctions: usize, max_parents: usize) -> TokenStream {
+		let mut from_tuples = (0..=max_junctions)
+			.map(|num_junctions| {
+				let types = (0..num_junctions).map(|i| format_ident!("J{}", i)).collect::<Vec<_>>();
+				let idents =
+					(0..num_junctions).map(|i| format_ident!("j{}", i)).collect::<Vec<_>>();
+				let array_size = num_junctions;
+				let interior = if num_junctions == 0 {
+					quote!(Junctions::Here)
+				} else {
+					let variant = format_ident!("X{}", num_junctions);
+					quote! {
+						Junctions::#variant( alloc::sync::Arc::new( [#(#idents .into()),*] ) )
+					}
+				};
+
+				let mut from_tuple = quote! {
+					impl< #(#types : Into<Junction>,)* > From<( Ancestor, #( #types ),* )> for Location {
+						fn from( ( Ancestor(parents), #(#idents),* ): ( Ancestor, #( #types ),* ) ) -> Self {
+							Location { parents, interior: #interior }
+						}
+					}
+
+					impl From<[Junction; #array_size]> for Location {
+						fn from(j: [Junction; #array_size]) -> Self {
+							let [#(#idents),*] = j;
+							Location { parents: 0, interior: #interior }
+						}
+					}
+				};
+
+				let from_parent_tuples = (0..=max_parents).map(|cur_parents| {
+					let parents =
+						(0..cur_parents).map(|_| format_ident!("Parent")).collect::<Vec<_>>();
+					let underscores =
+						(0..cur_parents).map(|_| Token![_](Span::call_site())).collect::<Vec<_>>();
+
+					quote! {
+						impl< #(#types : Into<Junction>,)* > From<( #( #parents , )* #( #types , )* )> for Location {
+							fn from( ( #(#underscores,)* #(#idents,)* ): ( #(#parents,)* #(#types,)* ) ) -> Self {
+								Self { parents: #cur_parents as u8, interior: #interior }
+							}
+						}
+					}
+				});
+
+				from_tuple.extend(from_parent_tuples);
+				from_tuple
+			})
+			.collect::<TokenStream>();
+
+		let from_parent_junctions_tuples = (0..=max_parents).map(|cur_parents| {
+			let parents = (0..cur_parents).map(|_| format_ident!("Parent")).collect::<Vec<_>>();
+			let underscores =
+				(0..cur_parents).map(|_| Token![_](Span::call_site())).collect::<Vec<_>>();
+
+			quote! {
+				impl From<( #(#parents,)* Junctions )> for Location {
+					fn from( (#(#underscores,)* junctions): ( #(#parents,)* Junctions ) ) -> Self {
+						Location { parents: #cur_parents as u8, interior: junctions }
+					}
+				}
+			}
+		});
+		from_tuples.extend(from_parent_junctions_tuples);
+
+		quote! {
+			impl From<(Ancestor, Junctions)> for Location {
+				fn from((Ancestor(parents), interior): (Ancestor, Junctions)) -> Self {
+					Location { parents, interior }
+				}
+			}
+
+			impl From<Junction> for Location {
+				fn from(x: Junction) -> Self {
+					Location { parents: 0, interior: [x].into() }
+				}
+			}
+
+			#from_tuples
+		}
+	}
+}
+
+pub mod junctions {
+	use super::*;
+
+	pub fn generate_conversion_functions(input: proc_macro::TokenStream) -> Result<TokenStream> {
+		if !input.is_empty() {
+			return Err(syn::Error::new(Span::call_site(), "No arguments expected"));
+		}
+
+		// Support up to 8 Parents in a tuple, assuming that most use cases don't go past 8 parents.
+		let from_v3 = generate_conversion_from_v3(MAX_JUNCTIONS);
+		let from_v5 = generate_conversion_from_v5(MAX_JUNCTIONS);
+		let from_tuples = generate_conversion_from_tuples(MAX_JUNCTIONS);
+
+		Ok(quote! {
+			#from_v3
+			#from_v5
+			#from_tuples
+		})
+	}
+
+	fn generate_conversion_from_tuples(max_junctions: usize) -> TokenStream {
+		(1..=max_junctions)
+			.map(|num_junctions| {
+				let idents =
+					(0..num_junctions).map(|i| format_ident!("j{}", i)).collect::<Vec<_>>();
+				let types = (0..num_junctions).map(|i| format_ident!("J{}", i)).collect::<Vec<_>>();
+
+				quote! {
+					impl<#(#types : Into<Junction>,)*> From<( #(#types,)* )> for Junctions {
+						fn from( ( #(#idents,)* ): ( #(#types,)* ) ) -> Self {
+							[#(#idents .into()),*].into()
+						}
+					}
+				}
+			})
+			.collect()
+	}
+
+	fn generate_conversion_from_v3(max_junctions: usize) -> TokenStream {
+		let match_variants = (0..max_junctions)
+			.map(|cur_num| {
+				let num_ancestors = cur_num + 1;
+				let variant = format_ident!("X{}", num_ancestors);
+				let idents = (0..=cur_num).map(|i| format_ident!("j{}", i)).collect::<Vec<_>>();
+				let convert = idents
+					.iter()
+					.map(|ident| {
+						quote! { let #ident = core::convert::TryInto::try_into(#ident.clone())?; }
+					})
+					.collect::<Vec<_>>();
+
+				quote! {
+					crate::v3::Junctions::#variant( #(#idents),* ) => {
+						#(#convert);*;
+						let junctions: Junctions = [#(#idents),*].into();
+						junctions
+					},
+				}
+			})
+			.collect::<TokenStream>();
+
+		quote! {
+			impl core::convert::TryFrom<crate::v3::Junctions> for Junctions {
+				type Error = ();
+				fn try_from(mut old: crate::v3::Junctions) -> core::result::Result<Self, ()> {
+					Ok(match old {
+					 crate::v3::Junctions::Here => Junctions::Here,
+					 #match_variants
+					})
+				}
+			}
+		}
+	}
+
+	fn generate_conversion_from_v5(max_junctions: usize) -> TokenStream {
+		let match_variants = (0..max_junctions)
+			.map(|current_number| {
+				let number_ancestors = current_number + 1;
+				let variant = format_ident!("X{}", number_ancestors);
+				let idents =
+					(0..=current_number).map(|i| format_ident!("j{}", i)).collect::<Vec<_>>();
+				let convert = idents
+					.iter()
+					.map(|ident| {
+						quote! { let #ident = core::convert::TryInto::try_into(#ident.clone())?; }
+					})
+					.collect::<Vec<_>>();
+
+				quote! {
+					crate::v5::Junctions::#variant( junctions ) => {
+						let [#(#idents),*] = &*junctions;
+						#(#convert);*
+						[#(#idents),*].into()
+					},
+				}
+			})
+			.collect::<TokenStream>();
+
+		quote! {
+			impl core::convert::TryFrom<crate::v5::Junctions> for Junctions {
+				type Error = ();
+
+				fn try_from(mut new: crate::v5::Junctions) -> core::result::Result<Self, Self::Error> {
+					use Junctions::*;
+					Ok(match new {
+						crate::v5::Junctions::Here => Here,
+						#match_variants
+					})
+				}
+			}
+		}
+	}
+}

pezkuwi/xcm/procedural/src/v5.rs

@@ -0,0 +1,198 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Pezkuwi is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+use proc_macro2::{Span, TokenStream};
+use quote::{format_ident, quote};
+use syn::{Result, Token};
+
+const MAX_JUNCTIONS: usize = 8;
+
+pub mod location {
+	use super::*;
+
+	/// Generates conversion functions from other types to the `Location` type:
+	/// - [PalletInstance(50), GeneralIndex(1984)].into()
+	/// - (Parent, Teyrchain(1000), AccountId32 { .. }).into()
+	pub fn generate_conversion_functions(input: proc_macro::TokenStream) -> Result<TokenStream> {
+		if !input.is_empty() {
+			return Err(syn::Error::new(Span::call_site(), "No arguments expected"));
+		}
+
+		let from_tuples = generate_conversion_from_tuples(8, 8);
+
+		Ok(quote! {
+			#from_tuples
+		})
+	}
+
+	fn generate_conversion_from_tuples(max_junctions: usize, max_parents: usize) -> TokenStream {
+		let mut from_tuples = (0..=max_junctions)
+			.map(|num_junctions| {
+				let types = (0..num_junctions).map(|i| format_ident!("J{}", i)).collect::<Vec<_>>();
+				let idents =
+					(0..num_junctions).map(|i| format_ident!("j{}", i)).collect::<Vec<_>>();
+				let array_size = num_junctions;
+				let interior = if num_junctions == 0 {
+					quote!(Junctions::Here)
+				} else {
+					let variant = format_ident!("X{}", num_junctions);
+					quote! {
+						Junctions::#variant( alloc::sync::Arc::new( [#(#idents .into()),*] ) )
+					}
+				};
+
+				let mut from_tuple = quote! {
+					impl< #(#types : Into<Junction>,)* > From<( Ancestor, #( #types ),* )> for Location {
+						fn from( ( Ancestor(parents), #(#idents),* ): ( Ancestor, #( #types ),* ) ) -> Self {
+							Location { parents, interior: #interior }
+						}
+					}
+
+					impl From<[Junction; #array_size]> for Location {
+						fn from(j: [Junction; #array_size]) -> Self {
+							let [#(#idents),*] = j;
+							Location { parents: 0, interior: #interior }
+						}
+					}
+				};
+
+				let from_parent_tuples = (0..=max_parents).map(|cur_parents| {
+					let parents =
+						(0..cur_parents).map(|_| format_ident!("Parent")).collect::<Vec<_>>();
+					let underscores =
+						(0..cur_parents).map(|_| Token![_](Span::call_site())).collect::<Vec<_>>();
+
+					quote! {
+						impl< #(#types : Into<Junction>,)* > From<( #( #parents , )* #( #types , )* )> for Location {
+							fn from( ( #(#underscores,)* #(#idents,)* ): ( #(#parents,)* #(#types,)* ) ) -> Self {
+								Self { parents: #cur_parents as u8, interior: #interior }
+							}
+						}
+					}
+				});
+
+				from_tuple.extend(from_parent_tuples);
+				from_tuple
+			})
+			.collect::<TokenStream>();
+
+		let from_parent_junctions_tuples = (0..=max_parents).map(|cur_parents| {
+			let parents = (0..cur_parents).map(|_| format_ident!("Parent")).collect::<Vec<_>>();
+			let underscores =
+				(0..cur_parents).map(|_| Token![_](Span::call_site())).collect::<Vec<_>>();
+
+			quote! {
+				impl From<( #(#parents,)* Junctions )> for Location {
+					fn from( (#(#underscores,)* junctions): ( #(#parents,)* Junctions ) ) -> Self {
+						Location { parents: #cur_parents as u8, interior: junctions }
+					}
+				}
+			}
+		});
+		from_tuples.extend(from_parent_junctions_tuples);
+
+		quote! {
+			impl From<(Ancestor, Junctions)> for Location {
+				fn from((Ancestor(parents), interior): (Ancestor, Junctions)) -> Self {
+					Location { parents, interior }
+				}
+			}
+
+			impl From<Junction> for Location {
+				fn from(x: Junction) -> Self {
+					Location { parents: 0, interior: [x].into() }
+				}
+			}
+
+			#from_tuples
+		}
+	}
+}
+
+pub mod junctions {
+	use super::*;
+
+	pub fn generate_conversion_functions(input: proc_macro::TokenStream) -> Result<TokenStream> {
+		if !input.is_empty() {
+			return Err(syn::Error::new(Span::call_site(), "No arguments expected"));
+		}
+
+		// Support up to 8 Parents in a tuple, assuming that most use cases don't go past 8 parents.
+		let from_v4 = generate_conversion_from_v4(MAX_JUNCTIONS);
+		let from_tuples = generate_conversion_from_tuples(MAX_JUNCTIONS);
+
+		Ok(quote! {
+			#from_v4
+			#from_tuples
+		})
+	}
+
+	fn generate_conversion_from_tuples(max_junctions: usize) -> TokenStream {
+		(1..=max_junctions)
+			.map(|num_junctions| {
+				let idents =
+					(0..num_junctions).map(|i| format_ident!("j{}", i)).collect::<Vec<_>>();
+				let types = (0..num_junctions).map(|i| format_ident!("J{}", i)).collect::<Vec<_>>();
+
+				quote! {
+					impl<#(#types : Into<Junction>,)*> From<( #(#types,)* )> for Junctions {
+						fn from( ( #(#idents,)* ): ( #(#types,)* ) ) -> Self {
+							[#(#idents .into()),*].into()
+						}
+					}
+				}
+			})
+			.collect()
+	}
+
+	fn generate_conversion_from_v4(max_junctions: usize) -> TokenStream {
+		let match_variants = (0..max_junctions)
+			.map(|cur_num| {
+				let num_ancestors = cur_num + 1;
+				let variant = format_ident!("X{}", num_ancestors);
+				let idents = (0..=cur_num).map(|i| format_ident!("j{}", i)).collect::<Vec<_>>();
+				let convert = idents
+					.iter()
+					.enumerate()
+					.map(|(index, ident)| {
+						quote! { let #ident = core::convert::TryInto::try_into(slice[#index].clone())?; }
+					})
+					.collect::<Vec<_>>();
+
+				quote! {
+					crate::v4::Junctions::#variant( arc ) => {
+						let slice = &arc[..];
+						#(#convert);*;
+						let junctions: Junctions = [#(#idents),*].into();
+						junctions
+					},
+				}
+			})
+			.collect::<TokenStream>();
+
+		quote! {
+			impl core::convert::TryFrom<crate::v4::Junctions> for Junctions {
+				type Error = ();
+				fn try_from(mut old: crate::v4::Junctions) -> core::result::Result<Self, ()> {
+					Ok(match old {
+					 crate::v4::Junctions::Here => Junctions::Here,
+					 #match_variants
+					})
+				}
+			}
+		}
+	}
+}

pezkuwi/xcm/procedural/src/weight_info.rs

@@ -0,0 +1,67 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Pezkuwi is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+use inflector::Inflector;
+use quote::format_ident;
+
+pub fn derive(item: proc_macro::TokenStream) -> proc_macro::TokenStream {
+	let input: syn::DeriveInput = match syn::parse(item) {
+		Ok(input) => input,
+		Err(e) => return e.into_compile_error().into(),
+	};
+
+	let syn::DeriveInput { generics, data, .. } = input;
+
+	match data {
+		syn::Data::Enum(syn::DataEnum { variants, .. }) => {
+			let methods = variants.into_iter().map(|syn::Variant { ident, fields, .. }| {
+				let snake_cased_ident = format_ident!("{}", ident.to_string().to_snake_case());
+				let ref_fields =
+					fields.into_iter().enumerate().map(|(idx, syn::Field { ident, ty, .. })| {
+						let field_name = ident.unwrap_or_else(|| format_ident!("_{}", idx));
+						let field_ty = match ty {
+							syn::Type::Reference(r) => {
+								// If the type is already a reference, do nothing
+								quote::quote!(#r)
+							},
+							t => {
+								// Otherwise, make it a reference
+								quote::quote!(&#t)
+							},
+						};
+
+						quote::quote!(#field_name: #field_ty,)
+					});
+				quote::quote!(fn #snake_cased_ident( #(#ref_fields)* ) -> Weight;)
+			});
+
+			let res = quote::quote! {
+				pub trait XcmWeightInfo #generics {
+					#(#methods)*
+				}
+			};
+			res.into()
+		},
+		syn::Data::Struct(syn::DataStruct { struct_token, .. }) => {
+			let msg = "structs are not supported by 'derive(XcmWeightInfo)'";
+			syn::Error::new(struct_token.span, msg).into_compile_error().into()
+		},
+		syn::Data::Union(syn::DataUnion { union_token, .. }) => {
+			let msg = "unions are not supported by 'derive(XcmWeightInfo)'";
+			syn::Error::new(union_token.span, msg).into_compile_error().into()
+		},
+	}
+}