Add missing events generation (#36)

* Add missing events generation

* Add event discriminator

* Add event discriminator

* Fix hash bug

* Fix hash bug

---------

Co-authored-by: Sergey Perfilev <[email protected]>
Co-authored-by: Ian Macalinao <[email protected]>

Author: 3 people

Cargo.lock

@@ -17,6 +17,7 @@ darling = "0.14"
 heck = "0.4.1"
 proc-macro2 = "1"
 quote = "1"
+sha2 = "0.9.2"
 serde_json = "1.0.108"
 syn = { version = "1", features = ["full"] }
 

crates/anchor-idl/Cargo.toml

@@ -0,0 +1,59 @@
+use std::collections::BTreeMap;
+
+use anchor_syn::idl::{IdlEvent, IdlField, IdlTypeDefinition};
+use proc_macro2::TokenStream;
+use quote::{format_ident, quote};
+use sha2::{Digest, Sha256};
+
+use crate::{generate_struct, StructOpts};
+
+/// Generates event structs.
+pub fn generate_events(
+    events: Option<&[IdlEvent]>,
+    typedefs: &[IdlTypeDefinition],
+    struct_opts: &BTreeMap<String, StructOpts>,
+) -> TokenStream {
+    match events {
+        Some(events) => {
+            let defined = events.iter().map(|def| {
+                let struct_name = format_ident!("{}", def.name);
+                let opts = struct_opts.get(&def.name).copied().unwrap_or_default();
+
+                let discriminator: proc_macro2::TokenStream = {
+                    let discriminator_preimage = format!("event:{}", struct_name);
+                    let mut discriminator = [0u8; 8];
+                    let mut hash = Sha256::default();
+                    hash.update(discriminator_preimage.as_bytes());
+                    discriminator.copy_from_slice(&hash.finalize()[..8]);
+                    format!("{:?}", discriminator).parse().unwrap()
+                };
+
+                let fields = def
+                    .fields
+                    .iter()
+                    .map(|f| IdlField {
+                        name: f.name.clone(),
+                        ty: f.ty.clone(),
+                    })
+                    .collect::<Vec<_>>();
+
+                let struct_ts = generate_struct(&typedefs, &struct_name, &fields, opts);
+
+                quote! {
+                    #struct_ts
+
+                    impl anchor_lang::Discriminator for #struct_name {
+                        const DISCRIMINATOR: [u8; 8] = #discriminator;
+                        fn discriminator() -> [u8; 8] {
+                            #discriminator
+                        }
+                    }
+                }
+            });
+            quote! {
+                #(#defined)*
+            }
+        }
+        None => quote!(),
+    }
+}

crates/anchor-idl/src/event.rs

@@ -3,13 +3,15 @@
 pub use anchor_lang_idl_spec::*;
 
 mod account;
+mod event;
 mod fields;
 mod instruction;
 mod program;
 mod state;
 mod typedef;
 
 pub use account::*;
+pub use event::*;
 pub use instruction::*;
 pub use program::*;
 pub use state::*;

crates/anchor-idl/src/lib.rs

@@ -9,7 +9,8 @@ use proc_macro2::{Ident, TokenStream};
 use quote::{format_ident, quote};
 
 use crate::{
-    generate_accounts, generate_ix_handlers, generate_ix_structs, generate_typedefs, GEN_VERSION,
+    generate_accounts, generate_events, generate_ix_handlers, generate_ix_structs,
+    generate_typedefs, GEN_VERSION,
 };
 
 #[derive(Default, FromMeta)]
@@ -85,6 +86,11 @@ impl Generator {
         let program_name: Ident = format_ident!("{}", idl.metadata.name);
 
         let accounts = generate_accounts(&idl.types, &idl.accounts, &self.struct_opts);
+        let events = generate_events(
+            idl.events.as_ref().map(|x| &x[..]),
+            &idl.types,
+            &self.struct_opts,
+        );
         let typedefs = generate_typedefs(&idl.types, &self.struct_opts);
         let ix_handlers = generate_ix_handlers(&idl.instructions);
         let ix_structs = generate_ix_structs(&idl.instructions);
@@ -115,6 +121,12 @@ impl Generator {
                 #accounts
             }
 
+            pub mod events {
+                //! Structs of events generated by program.
+                use super::*;
+                #events
+            }
+
             pub mod ix_accounts {
                 //! Accounts used in instructions.
                 use super::*;