lang: Add declare_program! macro (#2857)

CHANGELOG.md

@@ -38,6 +38,7 @@ The minor version will be incremented upon a breaking change and the patch versi
 - cli: Add `--no-idl` flag to the `build` command ([#2847](https://github.com/coral-xyz/anchor/pull/2847)).
 - cli: Add priority fees to idl commands ([#2845](https://github.com/coral-xyz/anchor/pull/2845)).
 - ts: Add `prepend` option to MethodBuilder `preInstructions` method ([#2863](https://github.com/coral-xyz/anchor/pull/2863)).
+- lang: Add `declare_program!` macro ([#2857](https://github.com/coral-xyz/anchor/pull/2857)).
 
 ### Fixes
 

lang/attribute/program/Cargo.toml

@@ -17,6 +17,11 @@ idl-build = ["anchor-syn/idl-build"]
 interface-instructions = ["anchor-syn/interface-instructions"]
 
 [dependencies]
-anchor-syn = { path = "../../syn", version = "0.29.0" }
+anchor-syn = { path = "../../syn", version = "0.29.0", features = ["idl-types"] }
+anyhow = "1"
+bs58 = "0.5"
+heck = "0.3"
+proc-macro2 = "1"
 quote = "1"
+serde_json = "1"
 syn = { version = "1", features = ["full"] }

lang/attribute/program/src/declare_program/common.rs

@@ -0,0 +1,360 @@
+use anchor_syn::idl::types::{
+    Idl, IdlArrayLen, IdlDefinedFields, IdlField, IdlGenericArg, IdlRepr, IdlSerialization,
+    IdlType, IdlTypeDef, IdlTypeDefGeneric, IdlTypeDefTy,
+};
+use quote::{format_ident, quote};
+
+/// This function should ideally return the absolute path to the declared program's id but because
+/// `proc_macro2::Span::call_site().source_file().path()` is behind an unstable feature flag, we
+/// are not able to reliably decide where the definition is.
+pub fn get_canonical_program_id() -> proc_macro2::TokenStream {
+    quote! { super::__ID }
+}
+
+pub fn gen_docs(docs: &[String]) -> proc_macro2::TokenStream {
+    let docs = docs
+        .iter()
+        .map(|doc| format!("{}{doc}", if doc.is_empty() { "" } else { " " }))
+        .map(|doc| quote! { #[doc = #doc] });
+    quote! { #(#docs)* }
+}
+
+pub fn gen_discriminator(disc: &[u8]) -> proc_macro2::TokenStream {
+    quote! { [#(#disc), *] }
+}
+
+pub fn gen_accounts_common(idl: &Idl, prefix: &str) -> proc_macro2::TokenStream {
+    let re_exports = idl
+        .instructions
+        .iter()
+        .map(|ix| format_ident!("__{}_accounts_{}", prefix, ix.name))
+        .map(|ident| quote! { pub use super::internal::#ident::*; });
+
+    quote! {
+        pub mod accounts {
+            #(#re_exports)*
+        }
+    }
+}
+
+pub fn convert_idl_type_to_syn_type(ty: &IdlType) -> syn::Type {
+    syn::parse_str(&convert_idl_type_to_str(ty)).unwrap()
+}
+
+// TODO: Impl `ToString` for `IdlType`
+pub fn convert_idl_type_to_str(ty: &IdlType) -> String {
+    match ty {
+        IdlType::Bool => "bool".into(),
+        IdlType::U8 => "u8".into(),
+        IdlType::I8 => "i8".into(),
+        IdlType::U16 => "u16".into(),
+        IdlType::I16 => "i16".into(),
+        IdlType::U32 => "u32".into(),
+        IdlType::I32 => "i32".into(),
+        IdlType::F32 => "f32".into(),
+        IdlType::U64 => "u64".into(),
+        IdlType::I64 => "i64".into(),
+        IdlType::F64 => "f64".into(),
+        IdlType::U128 => "u128".into(),
+        IdlType::I128 => "i128".into(),
+        IdlType::U256 => "u256".into(),
+        IdlType::I256 => "i256".into(),
+        IdlType::Bytes => "bytes".into(),
+        IdlType::String => "String".into(),
+        IdlType::Pubkey => "Pubkey".into(),
+        IdlType::Option(ty) => format!("Option<{}>", convert_idl_type_to_str(ty)),
+        IdlType::Vec(ty) => format!("Vec<{}>", convert_idl_type_to_str(ty)),
+        IdlType::Array(ty, len) => format!(
+            "[{}; {}]",
+            convert_idl_type_to_str(ty),
+            match len {
+                IdlArrayLen::Generic(len) => len.into(),
+                IdlArrayLen::Value(len) => len.to_string(),
+            }
+        ),
+        IdlType::Defined { name, generics } => generics
+            .iter()
+            .map(|generic| match generic {
+                IdlGenericArg::Type { ty } => convert_idl_type_to_str(ty),
+                IdlGenericArg::Const { value } => value.into(),
+            })
+            .reduce(|mut acc, cur| {
+                if !acc.is_empty() {
+                    acc.push(',');
+                }
+                acc.push_str(&cur);
+                acc
+            })
+            .map(|generics| format!("{name}<{generics}>"))
+            .unwrap_or(name.into()),
+        IdlType::Generic(ty) => ty.into(),
+    }
+}
+
+pub fn convert_idl_type_def_to_ts(
+    ty_def: &IdlTypeDef,
+    ty_defs: &[IdlTypeDef],
+) -> proc_macro2::TokenStream {
+    let name = format_ident!("{}", ty_def.name);
+    let docs = gen_docs(&ty_def.docs);
+
+    let generics = {
+        let generics = ty_def
+            .generics
+            .iter()
+            .map(|generic| match generic {
+                IdlTypeDefGeneric::Type { name } => format_ident!("{name}"),
+                IdlTypeDefGeneric::Const { name, ty } => format_ident!("{name}: {ty}"),
+            })
+            .collect::<Vec<_>>();
+        if generics.is_empty() {
+            quote!()
+        } else {
+            quote!(<#(#generics,)*>)
+        }
+    };
+
+    let attrs = {
+        let debug_attr = quote!(#[derive(Debug)]);
+
+        let default_attr = can_derive_default(ty_def, ty_defs)
+            .then(|| quote!(#[derive(Default)]))
+            .unwrap_or_default();
+
+        let ser_attr = match &ty_def.serialization {
+            IdlSerialization::Borsh => quote!(#[derive(AnchorSerialize, AnchorDeserialize)]),
+            IdlSerialization::Bytemuck => quote!(#[zero_copy]),
+            IdlSerialization::BytemuckUnsafe => quote!(#[zero_copy(unsafe)]),
+            _ => unimplemented!("{:?}", ty_def.serialization),
+        };
+
+        let clone_attr = matches!(ty_def.serialization, IdlSerialization::Borsh)
+            .then(|| quote!(#[derive(Clone)]))
+            .unwrap_or_default();
+
+        let copy_attr = matches!(ty_def.serialization, IdlSerialization::Borsh)
+            .then(|| can_derive_copy(ty_def, ty_defs).then(|| quote!(#[derive(Copy)])))
+            .flatten()
+            .unwrap_or_default();
+
+        quote! {
+            #debug_attr
+            #default_attr
+            #ser_attr
+            #clone_attr
+            #copy_attr
+        }
+    };
+
+    let repr = if let Some(repr) = &ty_def.repr {
+        let kind = match repr {
+            IdlRepr::Rust(_) => "Rust",
+            IdlRepr::C(_) => "C",
+            IdlRepr::Transparent => "transparent",
+        };
+        let kind = format_ident!("{kind}");
+
+        let modifier = match repr {
+            IdlRepr::Rust(modifier) | IdlRepr::C(modifier) => {
+                let packed = modifier.packed.then(|| quote!(packed)).unwrap_or_default();
+                let align = modifier
+                    .align
+                    .map(|align| quote!(align(#align)))
+                    .unwrap_or_default();
+
+                if packed.is_empty() {
+                    align
+                } else if align.is_empty() {
+                    packed
+                } else {
+                    quote! { #packed, #align }
+                }
+            }
+            _ => quote!(),
+        };
+        let modifier = if modifier.is_empty() {
+            modifier
+        } else {
+            quote! { , #modifier }
+        };
+
+        quote! { #[repr(#kind #modifier)] }
+    } else {
+        quote!()
+    };
+
+    let ty = match &ty_def.ty {
+        IdlTypeDefTy::Struct { fields } => {
+            let declare_struct = quote! { pub struct #name #generics };
+            handle_defined_fields(
+                fields.as_ref(),
+                || quote! { #declare_struct; },
+                |fields| {
+                    let fields = fields.iter().map(|field| {
+                        let name = format_ident!("{}", field.name);
+                        let ty = convert_idl_type_to_syn_type(&field.ty);
+                        quote! { pub #name : #ty }
+                    });
+                    quote! {
+                        #declare_struct {
+                            #(#fields,)*
+                        }
+                    }
+                },
+                |tys| {
+                    let tys = tys.iter().map(convert_idl_type_to_syn_type);
+                    quote! {
+                        #declare_struct (#(#tys,)*);
+                    }
+                },
+            )
+        }
+        IdlTypeDefTy::Enum { variants } => {
+            let variants = variants.iter().map(|variant| {
+                let variant_name = format_ident!("{}", variant.name);
+                handle_defined_fields(
+                    variant.fields.as_ref(),
+                    || quote! { #variant_name },
+                    |fields| {
+                        let fields = fields.iter().map(|field| {
+                            let name = format_ident!("{}", field.name);
+                            let ty = convert_idl_type_to_syn_type(&field.ty);
+                            quote! { #name : #ty }
+                        });
+                        quote! {
+                            #variant_name {
+                                #(#fields,)*
+                            }
+                        }
+                    },
+                    |tys| {
+                        let tys = tys.iter().map(convert_idl_type_to_syn_type);
+                        quote! {
+                            #variant_name (#(#tys,)*)
+                        }
+                    },
+                )
+            });
+
+            quote! {
+                pub enum #name #generics {
+                    #(#variants,)*
+                }
+            }
+        }
+        IdlTypeDefTy::Type { alias } => {
+            let alias = convert_idl_type_to_syn_type(alias);
+            quote! { pub type #name = #alias; }
+        }
+    };
+
+    quote! {
+        #docs
+        #attrs
+        #repr
+        #ty
+    }
+}
+
+fn can_derive_copy(ty_def: &IdlTypeDef, ty_defs: &[IdlTypeDef]) -> bool {
+    match &ty_def.ty {
+        IdlTypeDefTy::Struct { fields } => {
+            can_derive_common(fields.as_ref(), ty_defs, can_derive_copy_ty)
+        }
+        IdlTypeDefTy::Enum { variants } => variants
+            .iter()
+            .all(|variant| can_derive_common(variant.fields.as_ref(), ty_defs, can_derive_copy_ty)),
+        IdlTypeDefTy::Type { alias } => can_derive_copy_ty(alias, ty_defs),
+    }
+}
+
+fn can_derive_default(ty_def: &IdlTypeDef, ty_defs: &[IdlTypeDef]) -> bool {
+    match &ty_def.ty {
+        IdlTypeDefTy::Struct { fields } => {
+            can_derive_common(fields.as_ref(), ty_defs, can_derive_default_ty)
+        }
+        // TODO: Consider storing the default enum variant in IDL
+        IdlTypeDefTy::Enum { .. } => false,
+        IdlTypeDefTy::Type { alias } => can_derive_default_ty(alias, ty_defs),
+    }
+}
+
+fn can_derive_copy_ty(ty: &IdlType, ty_defs: &[IdlTypeDef]) -> bool {
+    match ty {
+        IdlType::Option(inner) => can_derive_copy_ty(inner, ty_defs),
+        IdlType::Array(inner, len) => {
+            if !can_derive_copy_ty(inner, ty_defs) {
+                return false;
+            }
+
+            match len {
+                IdlArrayLen::Value(_) => true,
+                IdlArrayLen::Generic(_) => false,
+            }
+        }
+        IdlType::Defined { name, .. } => ty_defs
+            .iter()
+            .find(|ty_def| &ty_def.name == name)
+            .map(|ty_def| can_derive_copy(ty_def, ty_defs))
+            .expect("Type def must exist"),
+        IdlType::Bytes | IdlType::String | IdlType::Vec(_) | IdlType::Generic(_) => false,
+        _ => true,
+    }
+}
+
+fn can_derive_default_ty(ty: &IdlType, ty_defs: &[IdlTypeDef]) -> bool {
+    match ty {
+        IdlType::Option(inner) => can_derive_default_ty(inner, ty_defs),
+        IdlType::Vec(inner) => can_derive_default_ty(inner, ty_defs),
+        IdlType::Array(inner, len) => {
+            if !can_derive_default_ty(inner, ty_defs) {
+                return false;
+            }
+
+            match len {
+                IdlArrayLen::Value(len) => *len <= 32,
+                IdlArrayLen::Generic(_) => false,
+            }
+        }
+        IdlType::Defined { name, .. } => ty_defs
+            .iter()
+            .find(|ty_def| &ty_def.name == name)
+            .map(|ty_def| can_derive_default(ty_def, ty_defs))
+            .expect("Type def must exist"),
+        IdlType::Generic(_) => false,
+        _ => true,
+    }
+}
+
+fn can_derive_common(
+    fields: Option<&IdlDefinedFields>,
+    ty_defs: &[IdlTypeDef],
+    can_derive_ty: fn(&IdlType, &[IdlTypeDef]) -> bool,
+) -> bool {
+    handle_defined_fields(
+        fields,
+        || true,
+        |fields| {
+            fields
+                .iter()
+                .map(|field| &field.ty)
+                .all(|ty| can_derive_ty(ty, ty_defs))
+        },
+        |tys| tys.iter().all(|ty| can_derive_ty(ty, ty_defs)),
+    )
+}
+
+fn handle_defined_fields<R>(
+    fields: Option<&IdlDefinedFields>,
+    unit_cb: impl Fn() -> R,
+    named_cb: impl Fn(&[IdlField]) -> R,
+    tuple_cb: impl Fn(&[IdlType]) -> R,
+) -> R {
+    match fields {
+        Some(fields) => match fields {
+            IdlDefinedFields::Named(fields) => named_cb(fields),
+            IdlDefinedFields::Tuple(tys) => tuple_cb(tys),
+        },
+        _ => unit_cb(),
+    }
+}