2019-06-08 18:16:07 -07:00

273 lines
11 KiB
Rust

#![recursion_limit="128"]
extern crate proc_macro;
use proc_macro::TokenStream;
use syn::{parse_macro_input, ItemStruct};
use quote::quote;
#[proc_macro_attribute]
pub fn pso_packet(attr: TokenStream, item: TokenStream) -> TokenStream {
let arg = parse_macro_input!(attr as syn::LitInt);
let pkt_cmd = arg.value() as u16;
let parsed = parse_macro_input!(item as ItemStruct);
let mut has_flag: bool = false;
let mut from_bytes = Vec::new();
let mut as_bytes = Vec::new();
let mut dbg_write_vars = Vec::new();
let mut partialeq = Vec::new();
for (i, f) in parsed.fields.iter().enumerate() {
if let Some(ident) = &f.ident {
let ident_str = ident.to_string();
match &f.ty {
syn::Type::Array(arr) => {
let array_length = if let syn::Expr::Lit(lit) = &arr.len {
if let syn::Lit::Int(int) = &lit.lit {
int.value() as usize
}
else {
return syn::Error::new(arr.bracket_token.span, "unknown array size").to_compile_error().into();
}
} else {
return syn::Error::new(arr.bracket_token.span, "unknown array size").to_compile_error().into();
};
match *arr.elem {
syn::Type::Path(ref path) => {
let ty = path.path.segments[0].ident.to_string();
if ty.as_str() == "u8_str" {
dbg_write_vars.push(quote! {
match std::str::from_utf8(&self.#ident) {
Ok(v) => write!(f, " {}: {:?}\n", #ident_str, v).unwrap(),
Err(_) => write!(f, " {}: {:?}\n", #ident_str, self.#ident.iter()).unwrap()
}
});
}
else {
dbg_write_vars.push(quote! {
write!(f, " {}: {:?}\n", #ident_str, self.#ident.iter()).unwrap();
});
}
//dbg_write_vars.push(quote! {
//write!(f, " {}: {:?}\n", #ident_str, self.#ident.iter()).unwrap();
/*match std::str::from_utf8(&self.#ident) {
Ok(v) => write!(f, " {}: {:?}\n", #ident_str, v).unwrap(),
Err(_) => write!(f, " {}: {:?}\n", #ident_str, self.#ident.iter()).unwrap()
}*/
//write!(f, " {}: {:?}\n", #ident_str, var_as_str).unwrap();
//});
as_bytes.push(quote! {
for f in self.#ident.iter() {
buf.extend_from_slice(&f.to_le_bytes())
}
});
match ty.as_str() {
"u8" | "u8_str" => {
from_bytes.push(quote! {
#ident: {
let mut b: [u8; #array_length] = [0; #array_length];
if let Ok(len) = cur.read(&mut b) {
if len != #array_length {
return Err(PacketParseError::NotEnoughBytes);
}
}
else {
return Err(PacketParseError::NotEnoughBytes);
};
b
},
});
},
_ => {
return syn::Error::new(path.path.segments[0].ident.span(), "type not supported")
.to_compile_error().into();
}
}
partialeq.push(quote! {
if self.#ident[..] != other.#ident[..] {
return false;
}
});
}
_ => {
panic!("why");
}
}
},
syn::Type::Path(path) => {
dbg_write_vars.push(quote! {
write!(f, " {}: {:?}\n", #ident_str, self.#ident).unwrap();
});
as_bytes.push(quote! {
buf.extend_from_slice(&self.#ident.to_le_bytes());
});
let ty = path.path.segments[0].ident.to_string();
match ty.as_str() {
"u8" | "u8_str" => {
from_bytes.push(quote! {
#ident: {
let mut b: [u8; 1] = [0; 1];
if let Ok(len) = cur.read(&mut b) {
if len != 1 {
return Err(PacketParseError::NotEnoughBytes);
}
}
else {
return Err(PacketParseError::NotEnoughBytes);
};
b[0]
},
});
},
"u16" => {
from_bytes.push(quote! {
#ident: {
let mut b: [u8; 2] = [0; 2];
if let Ok(len) = cur.read(&mut b) {
if len != 2 {
return Err(PacketParseError::NotEnoughBytes);
}
}
else {
return Err(PacketParseError::NotEnoughBytes);
};
u16::from_le_bytes(b)
},
});
},
"u32" => {
if ident_str == "flag" {
if i != 0 {
return syn::Error::new(ident.span(), "flag must be first member of struct").to_compile_error().into();
}
has_flag = true;
continue;
}
from_bytes.push(quote! {
#ident: {
let mut b: [u8; 4] = [0; 4];
if let Ok(len) = cur.read(&mut b) {
if len != 4 {
return Err(PacketParseError::NotEnoughBytes);
}
}
else {
return Err(PacketParseError::NotEnoughBytes);
};
u32::from_le_bytes(b)
},
});
},
_ => {
return syn::Error::new(path.path.segments[0].ident.span(), "type not supported")
.to_compile_error().into();
}
}
partialeq.push(quote! {
if self.#ident != other.#ident {
return false;
}
});
}
_ => {
}
}
}
}
let this_struct = parsed.ident.clone();
let this_struct_str = this_struct.to_string();
let flag_write = if has_flag {
quote! {
buf.extend_from_slice(&u32::to_le_bytes(self.flag));
}
}
else {
quote! {
buf.extend_from_slice(&u32::to_le_bytes(0));
}
};
let psopacket = quote! {
impl PSOPacket for #this_struct {
fn from_bytes(data: &Vec<u8>) -> Result<#this_struct, PacketParseError> {
let mut cur = std::io::Cursor::new(data);
cur.seek(SeekFrom::Start(2)).unwrap();
let mut b: [u8; 2] = [0; 2];
cur.read(&mut b).unwrap();
let cmd = u16::from_le_bytes(b);
if cmd != #pkt_cmd {
return Err(PacketParseError::WrongPacketCommand);
}
if #has_flag {
cur.seek(SeekFrom::Start(4)).unwrap();
}
else {
cur.seek(SeekFrom::Start(8)).unwrap();
}
Ok(#this_struct {
#(#from_bytes)*
})
}
fn as_bytes(&self) -> Vec<u8> {
let mut buf: Vec<u8> = Vec::new();
#flag_write
#(#as_bytes)*
let pkt_len = buf.len() as u16;
let mut prebuf: Vec<u8> = Vec::new();
prebuf.extend_from_slice(&u16::to_le_bytes(pkt_len));
prebuf.extend_from_slice(&u16::to_le_bytes(#pkt_cmd));
prebuf.append(&mut buf);
prebuf
}
}
};
let psopacket_debug = quote! {
impl std::fmt::Debug for #this_struct {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
write!(f, "packet {} {{\n", #this_struct_str).unwrap();
#(#dbg_write_vars)*
write!(f, "}}")
}
}
};
let psopacket_partialeq = quote! {
impl std::cmp::PartialEq for #this_struct {
fn eq(&self, other: &Self) -> bool {
#(#partialeq)*
true
}
}
};
let q = quote! {
#parsed
#psopacket
#psopacket_debug
#psopacket_partialeq
};
//println!("[[[{}]]]", q.to_string());
q.into()
}
#[proc_macro_attribute]
pub fn game_command(attr: TokenStream, item: TokenStream) -> TokenStream {
item
}