193: remove unused check r=japaric a=japaric

that was added in #140 but it's no longer required

this PR also adds some cfail tests to test the updated code

Co-authored-by: Jorge Aparicio <jorge@japaric.io>
This commit is contained in:
bors[bot] 2019-05-21 19:05:11 +00:00
commit 16614919c0
3 changed files with 49 additions and 260 deletions

View file

@ -1,7 +1,7 @@
use std::{collections::HashSet, iter}; use std::{collections::HashSet, iter};
use proc_macro2::Span; use proc_macro2::Span;
use syn::{parse, spanned::Spanned, Block, Expr, Stmt}; use syn::parse;
use crate::syntax::App; use crate::syntax::App;
@ -35,12 +35,22 @@ pub fn app(app: &App) -> parse::Result<()> {
} }
} }
// Check that `init` returns `LateResources` if there's any declared late resource if app.resources.iter().any(|(_, res)| res.expr.is_none()) {
if !app.init.returns_late_resources && app.resources.iter().any(|(_, res)| res.expr.is_none()) { // Check that `init` returns `LateResources` if there's any declared late resource
return Err(parse::Error::new( if !app.init.returns_late_resources {
app.init.span, return Err(parse::Error::new(
"late resources have been specified so `init` must return `init::LateResources`", app.init.span,
)); "late resources have been specified so `init` must return `init::LateResources`",
));
}
} else if app.init.returns_late_resources {
// If there are no late resources the signature should be `fn(init::Context)`
if app.init.returns_late_resources {
return Err(parse::Error::new(
app.init.span,
"`init` signature must be `fn(init::Context)` if there are no late resources",
));
}
} }
// Check that all referenced tasks have been declared // Check that all referenced tasks have been declared
@ -108,258 +118,5 @@ pub fn app(app: &App) -> parse::Result<()> {
} }
} }
// Check that `init` contains no early returns *if* late resources exist and `init` signature is
// `fn()`
if app.resources.values().any(|res| res.expr.is_none()) {
if !app.init.returns_late_resources {
for stmt in &app.init.stmts {
noreturn_stmt(stmt)?;
}
}
} else if app.init.returns_late_resources {
return Err(parse::Error::new(
Span::call_site(),
"`init` signature must be `fn(init::Context)` if there are no late resources",
));
}
Ok(())
}
// checks that the given block contains no instance of `return`
fn noreturn_block(block: &Block) -> Result<(), parse::Error> {
for stmt in &block.stmts {
noreturn_stmt(stmt)?;
}
Ok(())
}
// checks that the given statement contains no instance of `return`
fn noreturn_stmt(stmt: &Stmt) -> Result<(), parse::Error> {
match stmt {
// `let x = ..` -- this may contain a return in the RHS
Stmt::Local(local) => {
if let Some(ref init) = local.init {
noreturn_expr(&init.1)?
}
}
// items have no effect on control flow
Stmt::Item(..) => {}
Stmt::Expr(expr) => noreturn_expr(expr)?,
Stmt::Semi(expr, ..) => noreturn_expr(expr)?,
}
Ok(())
}
// checks that the given expression contains no `return`
fn noreturn_expr(expr: &Expr) -> Result<(), parse::Error> {
match expr {
Expr::Box(b) => noreturn_expr(&b.expr)?,
Expr::InPlace(ip) => {
noreturn_expr(&ip.place)?;
noreturn_expr(&ip.value)?;
}
Expr::Array(a) => {
for elem in &a.elems {
noreturn_expr(elem)?;
}
}
Expr::Call(c) => {
noreturn_expr(&c.func)?;
for arg in &c.args {
noreturn_expr(arg)?;
}
}
Expr::MethodCall(mc) => {
noreturn_expr(&mc.receiver)?;
for arg in &mc.args {
noreturn_expr(arg)?;
}
}
Expr::Tuple(t) => {
for elem in &t.elems {
noreturn_expr(elem)?;
}
}
Expr::Binary(b) => {
noreturn_expr(&b.left)?;
noreturn_expr(&b.right)?;
}
Expr::Unary(u) => {
noreturn_expr(&u.expr)?;
}
Expr::Lit(..) => {}
Expr::Cast(c) => {
noreturn_expr(&c.expr)?;
}
Expr::Type(t) => {
noreturn_expr(&t.expr)?;
}
Expr::Let(l) => {
noreturn_expr(&l.expr)?;
}
Expr::If(i) => {
noreturn_expr(&i.cond)?;
noreturn_block(&i.then_branch)?;
if let Some(ref e) = i.else_branch {
noreturn_expr(&e.1)?;
}
}
Expr::While(w) => {
noreturn_expr(&w.cond)?;
noreturn_block(&w.body)?;
}
Expr::ForLoop(fl) => {
noreturn_expr(&fl.expr)?;
noreturn_block(&fl.body)?;
}
Expr::Loop(l) => {
noreturn_block(&l.body)?;
}
Expr::Match(m) => {
noreturn_expr(&m.expr)?;
for arm in &m.arms {
if let Some(g) = &arm.guard {
noreturn_expr(&g.1)?;
}
noreturn_expr(&arm.body)?;
}
}
// we don't care about `return`s inside closures
Expr::Closure(..) => {}
Expr::Unsafe(u) => {
noreturn_block(&u.block)?;
}
Expr::Block(b) => {
noreturn_block(&b.block)?;
}
Expr::Assign(a) => {
noreturn_expr(&a.left)?;
noreturn_expr(&a.right)?;
}
Expr::AssignOp(ao) => {
noreturn_expr(&ao.left)?;
noreturn_expr(&ao.right)?;
}
Expr::Field(f) => {
noreturn_expr(&f.base)?;
}
Expr::Index(i) => {
noreturn_expr(&i.expr)?;
noreturn_expr(&i.index)?;
}
Expr::Range(r) => {
if let Some(ref f) = r.from {
noreturn_expr(f)?;
}
if let Some(ref t) = r.to {
noreturn_expr(t)?;
}
}
Expr::Path(..) => {}
Expr::Reference(r) => {
noreturn_expr(&r.expr)?;
}
Expr::Break(b) => {
if let Some(ref e) = b.expr {
noreturn_expr(e)?;
}
}
Expr::Continue(..) => {}
Expr::Return(r) => {
return Err(parse::Error::new(
r.span(),
"`init` is *not* allowed to early return",
));
}
// we can not analyze this
Expr::Macro(..) => {}
Expr::Struct(s) => {
for field in &s.fields {
noreturn_expr(&field.expr)?;
}
if let Some(ref rest) = s.rest {
noreturn_expr(rest)?;
}
}
Expr::Repeat(r) => {
noreturn_expr(&r.expr)?;
noreturn_expr(&r.len)?;
}
Expr::Paren(p) => {
noreturn_expr(&p.expr)?;
}
Expr::Group(g) => {
noreturn_expr(&g.expr)?;
}
Expr::Try(t) => {
noreturn_expr(&t.expr)?;
}
// we don't care about `return`s inside async blocks
Expr::Async(..) => {}
Expr::TryBlock(tb) => {
noreturn_block(&tb.block)?;
}
Expr::Yield(y) => {
if let Some(expr) = &y.expr {
noreturn_expr(expr)?;
}
}
// we can not analyze this
Expr::Verbatim(..) => {}
}
Ok(()) Ok(())
} }

View file

@ -0,0 +1,15 @@
#![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(_: init::Context) -> init::LateResources {}
//~^ error: `init` signature must be `fn(init::Context)` if there are no late resources
};

View file

@ -0,0 +1,17 @@
#![no_main]
#![no_std]
extern crate lm3s6965;
extern crate panic_halt;
extern crate rtfm;
use rtfm::app;
#[app(device = lm3s6965)]
const APP: () = {
static mut X: i32 = ();
#[init]
fn init(_: init::Context) {}
//~^ error: late resources have been specified so `init` must return `init::LateResources`
};