idl: Move IDL types from the anchor-syn crate to the new IDL crate

CHANGELOG.md

@@ -87,6 +87,7 @@ The minor version will be incremented upon a breaking change and the patch versi
 - ts: `Program` instances use camelCase for everything ([#2824](https://github.com/coral-xyz/anchor/pull/2824)).
 - ts: Remove discriminator functions ([#2824](https://github.com/coral-xyz/anchor/pull/2824)).
 - ts: Remove `programId` parameter of the `Program` constructor ([#2864](https://github.com/coral-xyz/anchor/pull/2864)).
+- idl, syn: Move IDL types from the `anchor-syn` crate to the new IDL crate ([#2882](https://github.com/coral-xyz/anchor/pull/2882)).
 
 ## [0.29.0] - 2023-10-16
 

idl/Cargo.toml

@@ -13,18 +13,13 @@ all-features = true
 rustdoc-args = ["--cfg", "docsrs"]
 
 [features]
-build = [
-    "anyhow",
-    "regex",
-    "serde",
-    "serde_json",
-]
+build = ["anchor-syn", "regex"]
 
 [dependencies]
-anchor-syn = { path = "../lang/syn", version = "0.29.0", features = ["idl-types"] }
+anyhow = "1"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
 
 # `build` feature only
-anyhow = { version = "1", optional = true }
+anchor-syn = { path = "../lang/syn", version = "0.29.0", optional = true }
 regex = { version = "1", optional = true }
-serde = { version = "1", features = ["derive"], optional = true }
-serde_json = { version = "1", optional = true }

idl/src/build.rs

@@ -12,6 +12,38 @@ use serde::Deserialize;
 
 use crate::types::{Idl, IdlEvent, IdlTypeDef};
 
+/// A trait that types must implement in order to include the type in the IDL definition.
+///
+/// This trait is automatically implemented for Anchor all types that use the `AnchorSerialize`
+/// proc macro. Note that manually implementing the `AnchorSerialize` trait does **NOT** have the
+/// same effect.
+///
+/// Types that don't implement this trait will cause a compile error during the IDL generation.
+///
+/// The default implementation of the trait allows the program to compile but the type does **NOT**
+/// get included in the IDL.
+pub trait IdlBuild {
+    /// Create an IDL type definition for the type.
+    ///
+    /// The type is only included in the IDL if this method returns `Some`.
+    fn create_type() -> Option<IdlTypeDef> {
+        None
+    }
+
+    /// Insert all types that are included in the current type definition to the given map.
+    fn insert_types(_types: &mut BTreeMap<String, IdlTypeDef>) {}
+
+    /// Get the full module path of the type.
+    ///
+    /// The full path will be used in the case of a conflicting type definition, e.g. when there
+    /// are multiple structs with the same name.
+    ///
+    /// The default implementation covers most cases.
+    fn get_full_path() -> String {
+        std::any::type_name::<Self>().into()
+    }
+}
+
 /// Generate IDL via compilation.
 pub fn build_idl(
     program_path: impl AsRef<Path>,

idl/src/lib.rs

@@ -4,3 +4,6 @@ pub mod types;
 
 #[cfg(feature = "build")]
 pub mod build;
+
+#[cfg(feature = "build")]
+pub use serde_json;