typhoon_handler_macro/
lib.rs

1use {
2    proc_macro::TokenStream,
3    quote::{quote, ToTokens},
4    syn::{parse::Parse, parse_macro_input, punctuated::Punctuated, Path, Token},
5};
6
7#[proc_macro]
8pub fn handlers(item: TokenStream) -> TokenStream {
9    parse_macro_input!(item as Handlers)
10        .to_token_stream()
11        .into()
12}
13
14struct Handlers {
15    instructions: Punctuated<Path, Token![,]>,
16}
17
18impl Parse for Handlers {
19    fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
20        let instructions = Punctuated::<Path, Token![,]>::parse_terminated(input)?;
21
22        Ok(Handlers { instructions })
23    }
24}
25
26impl ToTokens for Handlers {
27    fn to_tokens(&self, tokens: &mut proc_macro2::TokenStream) {
28        let instructions = self.instructions.iter().enumerate().map(|(i, val)| {
29            let i = i as u8;
30            quote! {
31                #i => handle(accounts, data, #val),
32            }
33        });
34
35        let expanded = quote! {
36            program_entrypoint!(process_instruction);
37
38            pub fn process_instruction(
39                program_id: &Pubkey,
40                accounts: &[AccountInfo],
41                instruction_data: &[u8],
42            ) -> Result<(), ProgramError> {
43                if program_id != &crate::ID {
44                    return Err(ProgramError::IncorrectProgramId);
45                }
46
47                let (discriminator, data) = instruction_data.split_first().ok_or(ProgramError::InvalidInstructionData)?;
48                let result = match discriminator {
49                    #(#instructions)*
50                    _ => Err(ProgramError::InvalidInstructionData.into()),
51                };
52
53                #[cfg(feature = "logging")]
54                result.inspect_err(log_error)?;
55
56                #[cfg(not(feature = "logging"))]
57                result?;
58
59                Ok(())
60            }
61        };
62
63        expanded.to_tokens(tokens);
64    }
65}
typhoon_handler_macro/lib.rs

typhoon_handler_macro/
lib.rs
