Merge pull request #13 from ramate-io/l-monninger/proc-macro

Adds proc macro to Fuste standard API for cleanliness.

Author: l-monninger

Cargo.lock

@@ -16,6 +16,7 @@ members = [
   "fuste/env/alloc",
   "fuste/env/galloc",
   "fuste/env/fuste",
+  "fuste/env/fuste-proc-macro",
 
   # specific systems
   "fuste/systems/tick/handler",
@@ -78,6 +79,7 @@ fuste-write = { path = "fuste/env/write" }
 fuste-channel = { path = "fuste/env/channel" }
 fuste-alloc = { path = "fuste/env/alloc" }
 fuste = { path = "fuste/env/fuste" }
+fuste-proc-macro = { path = "fuste/env/fuste-proc-macro" }
 
 # specific systems
 fuste-interrupt-handler = { path = "fuste/systems/interrupt/handler" }

Cargo.toml

@@ -0,0 +1,24 @@
+[package]
+name = "fuste-proc-macro"
+version = { workspace = true }
+edition = "2021"
+license = { workspace = true }
+authors = { workspace = true }
+repository = { workspace = true }
+homepage = { workspace = true }
+publish = { workspace = true }
+rust-version = { workspace = true }
+
+[lib]
+proc-macro = true
+
+[dependencies]
+syn = { workspace = true, features = ["full"] }
+quote = { workspace = true }
+proc-macro2 = { workspace = true }
+
+[package.metadata.cargo-machete]
+ignored = ["proc-macro2"]
+
+[lints]
+workspace = true

fuste/env/fuste-proc-macro/Cargo.toml

@@ -0,0 +1,57 @@
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{parse_macro_input, ItemFn};
+
+/// Attribute macro: #[entry]
+#[proc_macro_attribute]
+pub fn main(_attr: TokenStream, item: TokenStream) -> TokenStream {
+	// Parse the function the user wrote
+	let input_fn = parse_macro_input!(item as ItemFn);
+
+	let fn_name = &input_fn.sig.ident;
+	let fn_vis = &input_fn.vis;
+	let fn_attrs = &input_fn.attrs;
+	let fn_block = &input_fn.block;
+	let fn_ret = &input_fn.sig.output;
+
+	// Generate expanded code
+	let expanded = quote! {
+
+		// Startup entry point
+		#[no_mangle]
+		fn _start() -> ! {
+			unsafe {
+				::core::arch::asm!(
+					"la sp, {stack}",
+					stack = sym _stack_end
+				);
+			}
+			_main();
+		}
+
+		extern "C" {
+			static _stack_end: u32;
+		}
+
+		// Main trampoline
+		#[no_mangle]
+		#[inline(never)]
+		pub extern "C" fn _main() -> ! {
+			let _ = #fn_name();
+			fuste::exit(fuste::ExitStatus::Success);
+		}
+
+		// Panic handler
+		#[panic_handler]
+		fn panic(_info: &::core::panic::PanicInfo) -> ! {
+			fuste::exit(fuste::ExitStatus::Error);
+		}
+
+		// Preserve original user function
+		#(#fn_attrs)*
+		#fn_vis fn #fn_name() #fn_ret
+		#fn_block
+	};
+
+	TokenStream::from(expanded)
+}

fuste/env/fuste-proc-macro/src/lib.rs

@@ -10,6 +10,7 @@ publish = { workspace = true }
 rust-version = { workspace = true }
 
 [dependencies]
+fuste-proc-macro = { workspace = true }
 fuste-ecall = { workspace = true }
 fuste-exit = { workspace = true }
 fuste-write = { workspace = true }

fuste/env/fuste/Cargo.toml

@@ -12,3 +12,4 @@ pub use fuste_write::{
 pub mod io;
 pub use io::{print, println};
 pub mod prelude;
+pub use fuste_proc_macro::main;

fuste/env/fuste/src/lib.rs

@@ -34,6 +34,10 @@ publish = false
 rust-version = "1.85.0"
 
 [workspace.dependencies]
+syn = { version = "2.0", features = ["full"] }
+quote = "1.0.23"
+proc-macro2 = "1.0.32"
+fuste-proc-macro = { path = "env/fuste-proc-macro" }
 fuste-ecall = { path = "env/ecall" }
 fuste-exit = { path = "env/exit" }
 fuste-write = { path = "env/write" }

fuste/tests/toolchain/Cargo.lock

@@ -2,20 +2,20 @@
 #![no_main]
 use fuste::{signer_at_index, Bytes, SignerStoreSystem};
 
-fuste::entry! {
-	fn main() -> Result<(), ()> {
+#[fuste::main]
+fn main() -> Result<(), ()> {
+	let signer_store = SignerStoreSystem::canonical();
+	let signer = signer_at_index(0).map_err(|_| ())?;
 
-		let signer_store = SignerStoreSystem::canonical();
-		let signer = signer_at_index(0).map_err(|_| ())?;
+	// signer stores are index by multiple signers
+	// for a single signer use an array of length 1
+	signer_store.store([signer.clone()], Bytes(*b"Hello, world!")).map_err(|_| ())?;
 
-		// signer stores are index by multiple signers
-		// for a single signer use an array of length 1
-		signer_store.store([signer.clone()], Bytes(*b"Hello, world!")).map_err(|_| ())?;
+	// to represent state that requires multiple signers, use a tuple
+	let second_signer = signer_at_index(1).map_err(|_| ())?;
+	signer_store
+		.store([signer, second_signer], Bytes(*b"Hello, world!\n\t- From two signers"))
+		.map_err(|_| ())?;
 
-		// to represent state that requires multiple signers, use a tuple
-		let second_signer = signer_at_index(1).map_err(|_| ())?;
-		signer_store.store([signer, second_signer], Bytes(*b"Hello, world!\n\t- From two signers")).map_err(|_| ())?;
-
-		Ok(())
-	}
+	Ok(())
 }

fuste/tests/toolchain/Cargo.toml

@@ -12,19 +12,18 @@ pub fn add(a: u32, b: u32) -> u32 {
 	a + b
 }
 
-fuste::entry! {
-	fn main() -> Result<(), ()> {
-		let mut j = 0;
-		for i in 0..10 {
-			assert_eq!(i, i);
-			j += i;
-			j = add(j, i);
-			println!("Hello, world!");
-			let s = "Hello, world!".to_string();
-			println!("s: {}", s);
-			println!("i: {}, j: {}", i, j);
-		}
-
-		Ok(())
+#[fuste::main]
+fn main() -> Result<(), ()> {
+	let mut j = 0;
+	for i in 0..10 {
+		assert_eq!(i, i);
+		j += i;
+		j = add(j, i);
+		println!("Hello, world!");
+		let s = "Hello, world!".to_string();
+		println!("s: {}", s);
+		println!("i: {}, j: {}", i, j);
 	}
+
+	Ok(())
 }