properly handle #[cfg] (conditional compilation) on resources

This commit is contained in:
Jorge Aparicio 2018-12-16 18:37:36 +01:00
parent 9757c33b00
commit 4345c10596
8 changed files with 362 additions and 77 deletions

View file

@ -14,12 +14,12 @@ version = "0.4.0-beta.3"
proc-macro = true
[dependencies]
quote = "0.6.8"
proc-macro2 = "0.4.20"
quote = "0.6.10"
proc-macro2 = "0.4.24"
[dependencies.syn]
features = ["extra-traits", "full"]
version = "0.15.6"
version = "0.15.23"
[dependencies.rand]
default-features = false

View file

@ -10,7 +10,7 @@ use std::{
use proc_macro2::Span;
use quote::quote;
use rand::{Rng, SeedableRng};
use syn::{ArgCaptured, Ident, IntSuffix, LitInt};
use syn::{parse_quote, ArgCaptured, Attribute, Ident, IntSuffix, LitInt};
use analyze::{Analysis, Ownership};
use syntax::{App, Idents, Static};
@ -86,8 +86,6 @@ struct Resources {
pub fn app(app: &App, analysis: &Analysis) -> TokenStream {
let mut ctxt = Context::default();
let device = &app.args.device;
let resources = resources(&mut ctxt, &app, analysis);
let tasks = tasks(&mut ctxt, &app, analysis);
@ -146,6 +144,7 @@ pub fn app(app: &App, analysis: &Analysis) -> TokenStream {
let assertions = assertions(app, analysis);
let main = mk_ident(None);
let init = &ctxt.init;
quote!(
#resources
@ -162,11 +161,7 @@ pub fn app(app: &App, analysis: &Analysis) -> TokenStream {
#root_interrupts
// We put these items into a pseudo-module to avoid a collision between the `interrupt`
// import and user code
const APP: () = {
use #device::interrupt;
#scoped_interrupts
#(#dispatchers)*
@ -178,10 +173,10 @@ pub fn app(app: &App, analysis: &Analysis) -> TokenStream {
#idle_fn
#[export_name = "main"]
#[allow(unsafe_code)]
#[rtfm::export::entry]
#[doc(hidden)]
unsafe fn main() -> ! {
unsafe fn #main() -> ! {
#assertions
rtfm::export::interrupt::disable();
@ -204,6 +199,7 @@ fn resources(ctxt: &mut Context, app: &App, analysis: &Analysis) -> proc_macro2:
let mut items = vec![];
let mut module = vec![];
for (name, res) in &app.resources {
let cfgs = &res.cfgs;
let attrs = &res.attrs;
let mut_ = &res.mutability;
let ty = &res.ty;
@ -219,6 +215,7 @@ fn resources(ctxt: &mut Context, app: &App, analysis: &Analysis) -> proc_macro2:
if let Some(Ownership::Shared { ceiling }) = analysis.ownerships.get(name) {
items.push(mk_resource(
ctxt,
cfgs,
name,
quote!(#name),
*ceiling,
@ -238,6 +235,7 @@ fn resources(ctxt: &mut Context, app: &App, analysis: &Analysis) -> proc_macro2:
.map(|expr| {
quote!(
#(#attrs)*
#(#cfgs)*
#[doc = #symbol]
static mut #alias: #ty = #expr;
)
@ -245,6 +243,7 @@ fn resources(ctxt: &mut Context, app: &App, analysis: &Analysis) -> proc_macro2:
.unwrap_or_else(|| {
quote!(
#(#attrs)*
#(#cfgs)*
#[doc = #symbol]
static mut #alias: rtfm::export::MaybeUninit<#ty> =
rtfm::export::MaybeUninit::uninitialized();
@ -262,6 +261,7 @@ fn resources(ctxt: &mut Context, app: &App, analysis: &Analysis) -> proc_macro2:
items.push(mk_resource(
ctxt,
cfgs,
name,
quote!(#ty),
*ceiling,
@ -297,6 +297,7 @@ fn init(ctxt: &mut Context, app: &App, analysis: &Analysis) -> proc_macro2::Toke
.assigns
.iter()
.map(|assign| {
let attrs = &assign.attrs;
if app
.resources
.get(&assign.left)
@ -305,11 +306,17 @@ fn init(ctxt: &mut Context, app: &App, analysis: &Analysis) -> proc_macro2::Toke
{
let alias = &ctxt.statics[&assign.left];
let expr = &assign.right;
quote!(unsafe { #alias.set(#expr); })
quote!(
#(#attrs)*
unsafe { #alias.set(#expr); }
)
} else {
let left = &assign.left;
let right = &assign.right;
quote!(#left = #right;)
quote!(
#(#attrs)*
#left = #right;
)
}
})
.collect::<Vec<_>>();
@ -607,12 +614,14 @@ fn prelude(
// NOTE This field is just to avoid unused type parameter errors around `'a`
defs.push(quote!(#[allow(dead_code)] #priority: &'a core::cell::Cell<u8>));
exprs.push(quote!(#priority));
exprs.push(parse_quote!(#priority));
let mut may_call_lock = false;
let mut needs_unsafe = false;
for name in resources {
let res = &app.resources[name];
let cfgs = &res.cfgs;
let initialized = res.expr.is_some();
let singleton = res.singleton;
let mut_ = res.mutability;
@ -624,23 +633,40 @@ fn prelude(
// owned by Init
if singleton {
needs_unsafe = true;
defs.push(quote!(pub #name: #name));
exprs.push(quote!(#name: <#name as owned_singleton::Singleton>::new()));
defs.push(quote!(
#(#cfgs)*
pub #name: #name
));
exprs.push(quote!(
#(#cfgs)*
#name: <#name as owned_singleton::Singleton>::new()
));
continue;
} else {
defs.push(quote!(pub #name: &'static #mut_ #ty));
defs.push(quote!(
#(#cfgs)*
pub #name: &'static #mut_ #ty
));
}
} else {
// owned by someone else
if singleton {
needs_unsafe = true;
defs.push(quote!(pub #name: &'a mut #name));
exprs
.push(quote!(#name: &mut <#name as owned_singleton::Singleton>::new()));
defs.push(quote!(
#(#cfgs)*
pub #name: &'a mut #name
));
exprs.push(quote!(
#(#cfgs)*
#name: &mut <#name as owned_singleton::Singleton>::new()
));
continue;
} else {
force_mut = true;
defs.push(quote!(pub #name: &'a mut #ty));
defs.push(quote!(
#(#cfgs)*
pub #name: &'a mut #ty
));
}
}
@ -648,9 +674,15 @@ fn prelude(
// Resources assigned to init are always const initialized
needs_unsafe = true;
if force_mut {
exprs.push(quote!(#name: &mut #alias));
exprs.push(quote!(
#(#cfgs)*
#name: &mut #alias
));
} else {
exprs.push(quote!(#name: &#mut_ #alias));
exprs.push(quote!(
#(#cfgs)*
#name: &#mut_ #alias
));
}
} else {
let ownership = &analysis.ownerships[name];
@ -661,23 +693,43 @@ fn prelude(
if singleton {
if mut_.is_none() {
needs_unsafe = true;
defs.push(quote!(pub #name: &'a #name));
exprs
.push(quote!(#name: &<#name as owned_singleton::Singleton>::new()));
defs.push(quote!(
#(#cfgs)*
pub #name: &'a #name
));
exprs.push(quote!(
#(#cfgs)*
#name: &<#name as owned_singleton::Singleton>::new()
));
continue;
} else {
// Generate a resource proxy
defs.push(quote!(pub #name: resources::#name<'a>));
exprs.push(quote!(#name: resources::#name { #priority }));
defs.push(quote!(
#(#cfgs)*
pub #name: resources::#name<'a>
));
exprs.push(quote!(
#(#cfgs)*
#name: resources::#name { #priority }
));
continue;
}
} else {
if mut_.is_none() {
defs.push(quote!(pub #name: &'a #ty));
defs.push(quote!(
#(#cfgs)*
pub #name: &'a #ty
));
} else {
// Generate a resource proxy
defs.push(quote!(pub #name: resources::#name<'a>));
exprs.push(quote!(#name: resources::#name { #priority }));
defs.push(quote!(
#(#cfgs)*
pub #name: resources::#name<'a>
));
exprs.push(quote!(
#(#cfgs)*
#name: resources::#name { #priority }
));
continue;
}
}
@ -685,29 +737,47 @@ fn prelude(
if singleton {
if kind.runs_once() {
needs_unsafe = true;
defs.push(quote!(pub #name: #name));
exprs.push(quote!(#name: <#name as owned_singleton::Singleton>::new()));
defs.push(quote!(
#(#cfgs)*
pub #name: #name
));
exprs.push(quote!(
#(#cfgs)*
#name: <#name as owned_singleton::Singleton>::new()
));
} else {
needs_unsafe = true;
if ownership.is_owned() || mut_.is_none() {
defs.push(quote!(pub #name: &'a #mut_ #name));
let alias = mk_ident(None);
items.push(quote!(
let #mut_ #alias = unsafe {
<#name as owned_singleton::Singleton>::new()
};
defs.push(quote!(
#(#cfgs)*
pub #name: &'a #mut_ #name
));
exprs.push(quote!(#name: &#mut_ #alias));
} else {
may_call_lock = true;
defs.push(quote!(pub #name: rtfm::Exclusive<'a, #name>));
let alias = mk_ident(None);
items.push(quote!(
#(#cfgs)*
let #mut_ #alias = unsafe {
<#name as owned_singleton::Singleton>::new()
};
));
exprs.push(quote!(
#(#cfgs)*
#name: &#mut_ #alias
));
} else {
may_call_lock = true;
defs.push(quote!(
#(#cfgs)*
pub #name: rtfm::Exclusive<'a, #name>
));
let alias = mk_ident(None);
items.push(quote!(
#(#cfgs)*
let #mut_ #alias = unsafe {
<#name as owned_singleton::Singleton>::new()
};
));
exprs.push(quote!(
#(#cfgs)*
#name: rtfm::Exclusive(&mut #alias)
));
}
@ -715,11 +785,17 @@ fn prelude(
continue;
} else {
if ownership.is_owned() || mut_.is_none() {
defs.push(quote!(pub #name: &#lt #mut_ #ty));
defs.push(quote!(
#(#cfgs)*
pub #name: &#lt #mut_ #ty
));
} else {
exclusive = true;
may_call_lock = true;
defs.push(quote!(pub #name: rtfm::Exclusive<#lt, #ty>));
defs.push(quote!(
#(#cfgs)*
pub #name: rtfm::Exclusive<#lt, #ty>
));
}
}
}
@ -728,9 +804,15 @@ fn prelude(
needs_unsafe = true;
if initialized {
if exclusive {
exprs.push(quote!(#name: rtfm::Exclusive(&mut #alias)));
exprs.push(quote!(
#(#cfgs)*
#name: rtfm::Exclusive(&mut #alias)
));
} else {
exprs.push(quote!(#name: &#mut_ #alias));
exprs.push(quote!(
#(#cfgs)*
#name: &#mut_ #alias
));
}
} else {
let method = if mut_.is_some() {
@ -740,9 +822,15 @@ fn prelude(
};
if exclusive {
exprs.push(quote!(#name: rtfm::Exclusive(#alias.#method()) ));
exprs.push(quote!(
#(#cfgs)*
#name: rtfm::Exclusive(#alias.#method())
));
} else {
exprs.push(quote!(#name: #alias.#method() ));
exprs.push(quote!(
#(#cfgs)*
#name: #alias.#method()
));
}
}
}
@ -755,6 +843,7 @@ fn prelude(
None
};
let defs = &defs;
let doc = format!("`{}::Resources`", kind.ident().to_string());
let decl = quote!(
#[doc = #doc]
@ -893,7 +982,6 @@ fn exceptions(ctxt: &mut Context, app: &App, analysis: &Analysis) -> Vec<proc_ma
.iter()
.map(|(ident, exception)| {
let attrs = &exception.attrs;
let statics = &exception.statics;
let stmts = &exception.stmts;
let prelude = prelude(
@ -934,15 +1022,18 @@ fn exceptions(ctxt: &mut Context, app: &App, analysis: &Analysis) -> Vec<proc_ma
() => quote!(),
};
let locals = mk_locals(&exception.statics, false);
let symbol = ident.to_string();
let alias = mk_ident(None);
let unsafety = &exception.unsafety;
quote!(
#module
#[rtfm::export::exception]
#[doc(hidden)]
#[export_name = #symbol]
#(#attrs)*
#unsafety fn #ident() {
#(#statics)*
#unsafety fn #alias() {
#(#locals)*
#baseline_let
@ -967,9 +1058,9 @@ fn interrupts(
let mut root = vec![];
let mut scoped = vec![];
let device = &app.args.device;
for (ident, interrupt) in &app.interrupts {
let attrs = &interrupt.attrs;
let statics = &interrupt.statics;
let stmts = &interrupt.stmts;
let prelude = prelude(
@ -1010,12 +1101,18 @@ fn interrupts(
() => quote!(),
};
let locals = mk_locals(&interrupt.statics, false);
let alias = mk_ident(None);
let symbol = ident.to_string();
let unsafety = &interrupt.unsafety;
scoped.push(quote!(
#[interrupt]
#(#attrs)*
#unsafety fn #ident() {
#(#statics)*
#[export_name = #symbol]
#unsafety fn #alias() {
// check that this interrupt exists
let _ = #device::interrupt::#ident;
#(#locals)*
#baseline_let
@ -1053,6 +1150,7 @@ fn tasks(ctxt: &mut Context, app: &App, analysis: &Analysis) -> proc_macro2::Tok
let resource = mk_resource(
ctxt,
&[],
&free_alias,
quote!(rtfm::export::FreeQueue<#capacity_ty>),
*analysis.free_queues.get(name).unwrap_or(&0),
@ -1182,6 +1280,7 @@ fn dispatchers(
let mut data = vec![];
let mut dispatchers = vec![];
let device = &app.args.device;
for (level, dispatcher) in &analysis.dispatchers {
let ready_alias = mk_ident(None);
let enum_alias = mk_ident(None);
@ -1194,6 +1293,7 @@ fn dispatchers(
let ceiling = *analysis.ready_queues.get(&level).unwrap_or(&0);
let resource = mk_resource(
ctxt,
&[],
&ready_alias,
ty.clone(),
ceiling,
@ -1212,8 +1312,6 @@ fn dispatchers(
#resource
));
let interrupt = &dispatcher.interrupt;
let arms = dispatcher
.tasks
.iter()
@ -1254,12 +1352,18 @@ fn dispatchers(
.collect::<Vec<_>>();
let attrs = &dispatcher.attrs;
let interrupt = &dispatcher.interrupt;
let symbol = interrupt.to_string();
let alias = mk_ident(None);
dispatchers.push(quote!(
#(#attrs)*
#[interrupt]
unsafe fn #interrupt() {
#[export_name = #symbol]
unsafe fn #alias() {
use core::ptr;
// check that this interrupt exists
let _ = #device::interrupt::#interrupt;
rtfm::export::run(|| {
while let Some((task, index)) = #ready_alias.get_mut().split().1.dequeue() {
match task {
@ -1519,6 +1623,7 @@ fn timer_queue(ctxt: &Context, app: &App, analysis: &Analysis) -> proc_macro2::T
items.push(mk_resource(
ctxt,
&[],
tq,
quote!(rtfm::export::TimerQueue<#enum_, #cap>),
analysis.timer_queue.ceiling,
@ -1551,10 +1656,11 @@ fn timer_queue(ctxt: &Context, app: &App, analysis: &Analysis) -> proc_macro2::T
.collect::<Vec<_>>();
let logical_prio = analysis.timer_queue.priority;
let alias = mk_ident(None);
items.push(quote!(
#[rtfm::export::exception]
#[export_name = "SysTick"]
#[doc(hidden)]
unsafe fn SysTick() {
unsafe fn #alias() {
use rtfm::Mutex;
let ref #priority = core::cell::Cell::new(#logical_prio);
@ -1680,6 +1786,7 @@ fn assertions(app: &App, analysis: &Analysis) -> proc_macro2::TokenStream {
fn mk_resource(
ctxt: &Context,
cfgs: &[Attribute],
struct_: &Ident,
ty: proc_macro2::TokenStream,
ceiling: u8,
@ -1696,6 +1803,7 @@ fn mk_resource(
let doc = format!("`{}`", ty);
module.push(quote!(
#[doc = #doc]
#(#cfgs)*
pub struct #struct_<'a> {
#[doc(hidden)]
pub #priority: &'a core::cell::Cell<u8>,
@ -1705,6 +1813,7 @@ fn mk_resource(
quote!(resources::#struct_)
} else {
items.push(quote!(
#(#cfgs)*
struct #struct_<'a> {
#priority: &'a core::cell::Cell<u8>,
}
@ -1714,6 +1823,7 @@ fn mk_resource(
};
items.push(quote!(
#(#cfgs)*
impl<'a> rtfm::Mutex for #path<'a> {
type T = #ty;
@ -1852,7 +1962,7 @@ fn tuple_ty(inputs: &[ArgCaptured]) -> proc_macro2::TokenStream {
}
}
#[derive(Clone, Eq, Hash, PartialEq)]
#[derive(Clone, Debug, Eq, Hash, PartialEq)]
enum Kind {
Exception(Ident),
Idle,

View file

@ -1,4 +1,4 @@
// #![deny(warnings)]
#![deny(warnings)]
#![recursion_limit = "128"]
extern crate proc_macro;
@ -308,5 +308,5 @@ pub fn app(args: TokenStream, input: TokenStream) -> TokenStream {
let analysis = analyze::app(&app);
// Code generation
codegen::app(&app, &analysis)
codegen::app(&app, &analysis).into()
}

View file

@ -47,7 +47,7 @@ impl Parse for AppArgs {
return Err(parse::Error::new(
ident.span(),
"expected `device`; other keys are not accepted",
))
));
}
}
@ -228,7 +228,7 @@ impl App {
return Err(parse::Error::new(
item.span(),
"this item must live outside the `#[app]` module",
))
));
}
}
}
@ -526,7 +526,7 @@ impl Parse for InitArgs {
return Err(parse::Error::new(
ident.span(),
"expected one of: resources, schedule or spawn",
))
));
}
}
@ -597,6 +597,7 @@ impl Parse for InitArgs {
}
pub struct Assign {
pub attrs: Vec<Attribute>,
pub left: Ident,
pub right: Box<Expr>,
}
@ -649,7 +650,7 @@ pub struct Exception {
pub args: ExceptionArgs,
pub attrs: Vec<Attribute>,
pub unsafety: Option<Token![unsafe]>,
pub statics: Statics,
pub statics: HashMap<Ident, Static>,
pub stmts: Vec<Stmt>,
}
@ -727,7 +728,7 @@ impl Exception {
args,
attrs: item.attrs,
unsafety: item.unsafety,
statics,
statics: Static::parse(statics)?,
stmts,
})
}
@ -737,7 +738,7 @@ pub struct Interrupt {
pub args: InterruptArgs,
pub attrs: Vec<Attribute>,
pub unsafety: Option<Token![unsafe]>,
pub statics: Statics,
pub statics: HashMap<Ident, Static>,
pub stmts: Vec<Stmt>,
}
@ -780,7 +781,7 @@ impl Interrupt {
args,
attrs: item.attrs,
unsafety: item.unsafety,
statics,
statics: Static::parse(statics)?,
stmts,
})
}
@ -788,6 +789,7 @@ impl Interrupt {
pub struct Resource {
pub singleton: bool,
pub cfgs: Vec<Attribute>,
pub attrs: Vec<Attribute>,
pub mutability: Option<Token![mut]>,
pub ty: Box<Type>,
@ -817,9 +819,12 @@ impl Resource {
);
}
let (cfgs, attrs) = extract_cfgs(item.attrs);
Ok(Resource {
singleton: pos.is_some(),
attrs: item.attrs,
cfgs,
attrs,
mutability: item.mutability,
ty: item.ty,
expr: if uninitialized { None } else { Some(item.expr) },
@ -981,7 +986,7 @@ fn parse_args(input: ParseStream, accept_capacity: bool) -> parse::Result<TaskAr
return Err(parse::Error::new(
ident.span(),
"expected one of: priority, resources, schedule or spawn",
))
));
}
}
@ -1210,6 +1215,7 @@ fn extract_assignments(stmts: Vec<Stmt>) -> (Vec<Stmt>, Vec<Assign>) {
if let Expr::Path(ref expr) = *assign.left {
if expr.path.segments.len() == 1 {
assigns.push(Assign {
attrs: assign.attrs,
left: expr.path.segments[0].ident.clone(),
right: assign.right,
});

View file

@ -10,7 +10,6 @@ pub use cortex_m::{
asm::wfi, interrupt, peripheral::scb::SystemHandler, peripheral::syst::SystClkSource,
peripheral::Peripherals,
};
pub use cortex_m_rt::{entry, exception};
pub use heapless::consts;
use heapless::spsc::{Queue, SingleCore};

View file

@ -0,0 +1,64 @@
#![no_main]
#![no_std]
extern crate lm3s6965;
extern crate panic_halt;
extern crate rtfm;
use rtfm::app;
#[app(device = lm3s6965)]
const APP: () = {
#[cfg(never)]
static mut O1: u32 = 0; // init
#[cfg(never)]
static mut O2: u32 = 0; // idle
#[cfg(never)]
static mut O3: u32 = 0; // EXTI0
#[cfg(never)]
static O4: u32 = 0; // idle
#[cfg(never)]
static O5: u32 = 0; // EXTI1
#[cfg(never)]
static O6: u32 = 0; // init
#[cfg(never)]
static mut S1: u32 = 0; // idle & EXTI0
#[cfg(never)]
static mut S2: u32 = 0; // EXTI0 & EXTI1
#[cfg(never)]
static S3: u32 = 0;
#[init(resources = [O1, O4, O5, O6, S3])]
fn init() {
resources.O1; //~ ERROR no field `O1`
resources.O4; //~ ERROR no field `O4`
resources.O5; //~ ERROR no field `O5`
resources.O6; //~ ERROR no field `O6`
resources.S3; //~ ERROR no field `S3`
}
#[idle(resources = [O2, O4, S1, S3])]
fn idle() -> ! {
resources.O2; //~ ERROR no field `O2`
resources.O4; //~ ERROR no field `O4`
resources.S1; //~ ERROR no field `S1`
resources.S3; //~ ERROR no field `S3`
loop {}
}
#[interrupt(resources = [O3, S1, S2, S3])]
fn UART0() {
resources.O3; //~ ERROR no field `O3`
resources.S1; //~ ERROR no field `S1`
resources.S2; //~ ERROR no field `S2`
resources.S3; //~ ERROR no field `S3`
}
#[interrupt(resources = [S2, O5])]
fn UART1() {
resources.S2; //~ ERROR no field `S2`
resources.O5; //~ ERROR no field `O5`
}
};

57
tests/cfail/cfg-static.rs Normal file
View file

@ -0,0 +1,57 @@
#![no_main]
#![no_std]
extern crate lm3s6965;
extern crate panic_halt;
extern crate rtfm;
use rtfm::app;
#[app(device = lm3s6965)]
const APP: () = {
#[init]
fn init() {
#[cfg(never)]
static mut FOO: u32 = 0;
FOO; //~ ERROR cannot find value `FOO` in this scope
}
#[idle]
fn idle() -> ! {
#[cfg(never)]
static mut FOO: u32 = 0;
FOO; //~ ERROR cannot find value `FOO` in this scope
loop {}
}
#[exception]
fn SVCall() {
#[cfg(never)]
static mut FOO: u32 = 0;
FOO; //~ ERROR cannot find value `FOO` in this scope
}
#[interrupt]
fn UART0() {
#[cfg(never)]
static mut FOO: u32 = 0;
FOO; //~ ERROR cannot find value `FOO` in this scope
}
#[task]
fn foo() {
#[cfg(never)]
static mut FOO: u32 = 0;
FOO; //~ ERROR cannot find value `FOO` in this scope
}
extern "C" {
fn UART1();
}
};

49
tests/cpass/cfg.rs Normal file
View file

@ -0,0 +1,49 @@
//! Compile-pass test that checks that `#[cfg]` attributes are respected
#![deny(unsafe_code)]
#![deny(warnings)]
#![no_main]
#![no_std]
extern crate lm3s6965;
extern crate panic_semihosting;
extern crate rtfm;
use rtfm::app;
#[app(device = lm3s6965)]
const APP: () = {
#[cfg(never)]
static mut FOO: u32 = 0;
#[init]
fn init() {
#[cfg(never)]
static mut BAR: u32 = 0;
}
#[idle]
fn idle() -> ! {
#[cfg(never)]
static mut BAR: u32 = 0;
loop {}
}
#[task(resources = [FOO])]
fn foo() {
#[cfg(never)]
static mut BAR: u32 = 0;
}
#[task(priority = 3, resources = [FOO])]
fn bar() {
#[cfg(never)]
static mut BAR: u32 = 0;
}
extern "C" {
fn UART0();
fn UART1();
}
};