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Rollup merge of #59823 - davidtwco:issue-54716, r=cramertj

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[wg-async-await] Drop `async fn` arguments in async block

Fixes #54716.

This PR modifies the HIR lowering (and some other places to make this work) so that unused arguments to a async function are always dropped inside the async move block and not at the end of the function body.

```
async fn foo(<pattern>: <type>) {
  async move {
  }
} // <-- dropped as you "exit" the fn

// ...becomes...
fn foo(__arg0: <ty>) {
  async move {
    let <pattern>: <ty> = __arg0;
  } // <-- dropped as you "exit" the async block
}
```

However, the exact ordering of drops is not the same as a regular function, [as visible in this playground example](https://play.rust-lang.org/?version=stable&mode=debug&edition=2015&gist=be39af1a58e5d430be1eb3c722cb1ec3) - I believe this to be an unrelated issue. There is a [Zulip topic](https://rust-lang.zulipchat.com/#narrow/stream/187312-t-compiler.2Fwg-async-await/topic/.2354716.20drop.20order) for this.

r? @cramertj
cc @nikomatsakis
This commit is contained in:
Mazdak Farrokhzad 2019-04-23 21:50:52 +02:00 • committed by GitHub
commit 62d1574876
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
27 changed files with 685 additions and 130 deletions
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16
src/librustc/hir/intravisit.rs
View file

@ -58,10 +58,10 @@ impl<'a> FnKind<'a> {
}
}
pub fn header(&self) -> Option<FnHeader> {
pub fn header(&self) -> Option<&FnHeader> {
match *self {
FnKind::ItemFn(_, _, header, _, _) => Some(header),
FnKind::Method(_, sig, _, _) => Some(sig.header),
FnKind::ItemFn(_, _, ref header, _, _) => Some(header),
FnKind::Method(_, ref sig, _, _) => Some(&sig.header),
FnKind::Closure(_) => None,
}
}
@ -262,6 +262,9 @@ pub trait Visitor<'v> : Sized {
fn visit_pat(&mut self, p: &'v Pat) {
walk_pat(self, p)
}
fn visit_argument_source(&mut self, s: &'v ArgSource) {
walk_argument_source(self, s)
}
fn visit_anon_const(&mut self, c: &'v AnonConst) {
walk_anon_const(self, c)
}
@ -399,10 +402,17 @@ pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &'v Body) {
for argument in &body.arguments {
visitor.visit_id(argument.hir_id);
visitor.visit_pat(&argument.pat);
visitor.visit_argument_source(&argument.source);
}
visitor.visit_expr(&body.value);
}
pub fn walk_argument_source<'v, V: Visitor<'v>>(visitor: &mut V, source: &'v ArgSource) {
if let ArgSource::AsyncFn(pat) = source {
visitor.visit_pat(pat);
}
}
pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local) {
// Intentionally visiting the expr first - the initialization expr
// dominates the local's definition.

184
src/librustc/hir/lowering.rs
View file

@ -448,10 +448,9 @@ impl<'a> LoweringContext<'a> {
impl<'lcx, 'interner> Visitor<'lcx> for MiscCollector<'lcx, 'interner> {
fn visit_pat(&mut self, p: &'lcx Pat) {
match p.node {
// Doesn't generate a Hir node
// Doesn't generate a HIR node
PatKind::Paren(..) => {},
_ => {
if let Some(owner) = self.hir_id_owner {
self.lctx.lower_node_id_with_owner(p.id, owner);
}
@ -461,6 +460,32 @@ impl<'a> LoweringContext<'a> {
visit::walk_pat(self, p)
}
fn visit_fn(&mut self, fk: visit::FnKind<'lcx>, fd: &'lcx FnDecl, s: Span, _: NodeId) {
if fk.header().map(|h| h.asyncness.node.is_async()).unwrap_or(false) {
// Don't visit the original pattern for async functions as it will be
// replaced.
for arg in &fd.inputs {
if let ArgSource::AsyncFn(pat) = &arg.source { self.visit_pat(pat); }
self.visit_ty(&arg.ty)
}
self.visit_fn_ret_ty(&fd.output);
match fk {
visit::FnKind::ItemFn(_, decl, _, body) => {
self.visit_fn_header(decl);
self.visit_block(body)
},
visit::FnKind::Method(_, sig, _, body) => {
self.visit_fn_header(&sig.header);
self.visit_block(body)
},
visit::FnKind::Closure(body) => self.visit_expr(body),
}
} else {
visit::walk_fn(self, fk, fd, s)
}
}
fn visit_item(&mut self, item: &'lcx Item) {
let hir_id = self.lctx.allocate_hir_id_counter(item.id).hir_id;
@ -784,12 +809,10 @@ impl<'a> LoweringContext<'a> {
})
}
fn record_body(&mut self, value: hir::Expr, decl: Option<&FnDecl>) -> hir::BodyId {
fn record_body(&mut self, value: hir::Expr, arguments: HirVec<hir::Arg>) -> hir::BodyId {
let body = hir::Body {
arguments: decl.map_or(hir_vec![], |decl| {
decl.inputs.iter().map(|x| self.lower_arg(x)).collect()
}),
is_generator: self.is_generator,
arguments,
value,
};
let id = body.id();
@ -1112,11 +1135,10 @@ impl<'a> LoweringContext<'a> {
capture_clause: CaptureBy,
closure_node_id: NodeId,
ret_ty: Option<&Ty>,
span: Span,
body: impl FnOnce(&mut LoweringContext<'_>) -> hir::Expr,
) -> hir::ExprKind {
let prev_is_generator = mem::replace(&mut self.is_generator, true);
let body_expr = body(self);
let span = body_expr.span;
let output = match ret_ty {
Some(ty) => FunctionRetTy::Ty(P(ty.clone())),
None => FunctionRetTy::Default(span),
@ -1126,7 +1148,11 @@ impl<'a> LoweringContext<'a> {
output,
c_variadic: false
};
let body_id = self.record_body(body_expr, Some(&decl));
// Lower the arguments before the body otherwise the body will call `lower_def` expecting
// the argument to have been assigned an id already.
let arguments = self.lower_args(Some(&decl));
let body_expr = body(self);
let body_id = self.record_body(body_expr, arguments);
self.is_generator = prev_is_generator;
let capture_clause = self.lower_capture_clause(capture_clause);
@ -1157,8 +1183,9 @@ impl<'a> LoweringContext<'a> {
F: FnOnce(&mut LoweringContext<'_>) -> hir::Expr,
{
let prev = mem::replace(&mut self.is_generator, false);
let arguments = self.lower_args(decl);
let result = f(self);
let r = self.record_body(result, decl);
let r = self.record_body(result, arguments);
self.is_generator = prev;
return r;
}
@ -2224,10 +2251,17 @@ impl<'a> LoweringContext<'a> {
init: l.init.as_ref().map(|e| P(self.lower_expr(e))),
span: l.span,
attrs: l.attrs.clone(),
source: hir::LocalSource::Normal,
source: self.lower_local_source(l.source),
}, ids)
}
fn lower_local_source(&mut self, ls: LocalSource) -> hir::LocalSource {
match ls {
LocalSource::Normal => hir::LocalSource::Normal,
LocalSource::AsyncFn => hir::LocalSource::AsyncFn,
}
}
fn lower_mutability(&mut self, m: Mutability) -> hir::Mutability {
match m {
Mutability::Mutable => hir::MutMutable,
@ -2235,11 +2269,23 @@ impl<'a> LoweringContext<'a> {
}
}
fn lower_args(&mut self, decl: Option<&FnDecl>) -> HirVec<hir::Arg> {
decl.map_or(hir_vec![], |decl| decl.inputs.iter().map(|x| self.lower_arg(x)).collect())
}
fn lower_arg(&mut self, arg: &Arg) -> hir::Arg {
let LoweredNodeId { node_id: _, hir_id } = self.lower_node_id(arg.id);
hir::Arg {
hir_id,
pat: self.lower_pat(&arg.pat),
source: self.lower_arg_source(&arg.source),
}
}
fn lower_arg_source(&mut self, source: &ArgSource) -> hir::ArgSource {
match source {
ArgSource::Normal => hir::ArgSource::Normal,
ArgSource::AsyncFn(pat) => hir::ArgSource::AsyncFn(self.lower_pat(pat)),
}
}
@ -2993,15 +3039,21 @@ impl<'a> LoweringContext<'a> {
fn lower_async_body(
&mut self,
decl: &FnDecl,
asyncness: IsAsync,
asyncness: &IsAsync,
body: &Block,
) -> hir::BodyId {
self.lower_body(Some(decl), |this| {
if let IsAsync::Async { closure_id, .. } = asyncness {
self.lower_body(Some(&decl), |this| {
if let IsAsync::Async { closure_id, ref arguments, .. } = asyncness {
let mut body = body.clone();
for a in arguments.iter().rev() {
body.stmts.insert(0, a.stmt.clone());
}
let async_expr = this.make_async_expr(
CaptureBy::Value, closure_id, None,
CaptureBy::Value, *closure_id, None, body.span,
|this| {
let body = this.lower_block(body, false);
let body = this.lower_block(&body, false);
this.expr_block(body, ThinVec::new())
});
this.expr(body.span, async_expr, ThinVec::new())
@ -3060,26 +3112,42 @@ impl<'a> LoweringContext<'a> {
value
)
}
ItemKind::Fn(ref decl, header, ref generics, ref body) => {
ItemKind::Fn(ref decl, ref header, ref generics, ref body) => {
let fn_def_id = self.resolver.definitions().local_def_id(id);
self.with_new_scopes(|this| {
// Note: we don't need to change the return type from `T` to
// `impl Future<Output = T>` here because lower_body
// only cares about the input argument patterns in the function
// declaration (decl), not the return types.
let body_id = this.lower_async_body(decl, header.asyncness.node, body);
let mut lower_fn = |decl: &FnDecl| {
// Note: we don't need to change the return type from `T` to
// `impl Future<Output = T>` here because lower_body
// only cares about the input argument patterns in the function
// declaration (decl), not the return types.
let body_id = this.lower_async_body(&decl, &header.asyncness.node, body);
let (generics, fn_decl) = this.add_in_band_defs(
generics,
fn_def_id,
AnonymousLifetimeMode::PassThrough,
|this, idty| this.lower_fn_decl(
decl,
Some((fn_def_id, idty)),
true,
header.asyncness.node.opt_return_id()
),
);
let (generics, fn_decl) = this.add_in_band_defs(
generics,
fn_def_id,
AnonymousLifetimeMode::PassThrough,
|this, idty| this.lower_fn_decl(
&decl,
Some((fn_def_id, idty)),
true,
header.asyncness.node.opt_return_id()
),
);
(body_id, generics, fn_decl)
};
let (body_id, generics, fn_decl) = if let IsAsync::Async {
arguments, ..
} = &header.asyncness.node {
let mut decl = decl.clone();
// Replace the arguments of this async function with the generated
// arguments that will be moved into the closure.
decl.inputs = arguments.clone().drain(..).map(|a| a.arg).collect();
lower_fn(&decl)
} else {
lower_fn(decl)
};
hir::ItemKind::Fn(
fn_decl,
@ -3558,15 +3626,33 @@ impl<'a> LoweringContext<'a> {
)
}
ImplItemKind::Method(ref sig, ref body) => {
let body_id = self.lower_async_body(&sig.decl, sig.header.asyncness.node, body);
let impl_trait_return_allow = !self.is_in_trait_impl;
let (generics, sig) = self.lower_method_sig(
&i.generics,
sig,
impl_item_def_id,
impl_trait_return_allow,
sig.header.asyncness.node.opt_return_id(),
);
let mut lower_method = |sig: &MethodSig| {
let body_id = self.lower_async_body(
&sig.decl, &sig.header.asyncness.node, body
);
let impl_trait_return_allow = !self.is_in_trait_impl;
let (generics, sig) = self.lower_method_sig(
&i.generics,
sig,
impl_item_def_id,
impl_trait_return_allow,
sig.header.asyncness.node.opt_return_id(),
);
(body_id, generics, sig)
};
let (body_id, generics, sig) = if let IsAsync::Async {
ref arguments, ..
} = sig.header.asyncness.node {
let mut sig = sig.clone();
// Replace the arguments of this async function with the generated
// arguments that will be moved into the closure.
sig.decl.inputs = arguments.clone().drain(..).map(|a| a.arg).collect();
lower_method(&sig)
} else {
lower_method(sig)
};
(generics, hir::ImplItemKind::Method(sig, body_id))
}
ImplItemKind::Type(ref ty) => (
@ -3760,7 +3846,7 @@ impl<'a> LoweringContext<'a> {
impl_trait_return_allow: bool,
is_async: Option<NodeId>,
) -> (hir::Generics, hir::MethodSig) {
let header = self.lower_fn_header(sig.header);
let header = self.lower_fn_header(&sig.header);
let (generics, decl) = self.add_in_band_defs(
generics,
fn_def_id,
@ -3782,10 +3868,10 @@ impl<'a> LoweringContext<'a> {
}
}
fn lower_fn_header(&mut self, h: FnHeader) -> hir::FnHeader {
fn lower_fn_header(&mut self, h: &FnHeader) -> hir::FnHeader {
hir::FnHeader {
unsafety: self.lower_unsafety(h.unsafety),
asyncness: self.lower_asyncness(h.asyncness.node),
asyncness: self.lower_asyncness(&h.asyncness.node),
constness: self.lower_constness(h.constness),
abi: h.abi,
}
@ -3805,7 +3891,7 @@ impl<'a> LoweringContext<'a> {
}
}
fn lower_asyncness(&mut self, a: IsAsync) -> hir::IsAsync {
fn lower_asyncness(&mut self, a: &IsAsync) -> hir::IsAsync {
match a {
IsAsync::Async { .. } => hir::IsAsync::Async,
IsAsync::NotAsync => hir::IsAsync::NotAsync,
@ -4110,7 +4196,7 @@ impl<'a> LoweringContext<'a> {
hir::MatchSource::Normal,
),
ExprKind::Async(capture_clause, closure_node_id, ref block) => {
self.make_async_expr(capture_clause, closure_node_id, None, |this| {
self.make_async_expr(capture_clause, closure_node_id, None, block.span, |this| {
this.with_new_scopes(|this| {
let block = this.lower_block(block, false);
this.expr_block(block, ThinVec::new())
@ -4118,7 +4204,7 @@ impl<'a> LoweringContext<'a> {
})
}
ExprKind::Closure(
capture_clause, asyncness, movability, ref decl, ref body, fn_decl_span
capture_clause, ref asyncness, movability, ref decl, ref body, fn_decl_span
) => {
if let IsAsync::Async { closure_id, .. } = asyncness {
let outer_decl = FnDecl {
@ -4156,7 +4242,7 @@ impl<'a> LoweringContext<'a> {
Some(&**ty)
} else { None };
let async_body = this.make_async_expr(
capture_clause, closure_id, async_ret_ty,
capture_clause, *closure_id, async_ret_ty, body.span,
|this| {
this.with_new_scopes(|this| this.lower_expr(body))
});

39
src/librustc/hir/map/def_collector.rs
View file

@ -68,16 +68,17 @@ impl<'a> DefCollector<'a> {
id: NodeId,
name: Name,
span: Span,
header: &FnHeader,
header: &'a FnHeader,
generics: &'a Generics,
decl: &'a FnDecl,
body: &'a Block,
) {
let (closure_id, return_impl_trait_id) = match header.asyncness.node {
let (closure_id, return_impl_trait_id, arguments) = match &header.asyncness.node {
IsAsync::Async {
closure_id,
return_impl_trait_id,
} => (closure_id, return_impl_trait_id),
arguments,
} => (closure_id, return_impl_trait_id, arguments),
_ => unreachable!(),
};
@ -86,17 +87,31 @@ impl<'a> DefCollector<'a> {
let fn_def_data = DefPathData::ValueNs(name.as_interned_str());
let fn_def = self.create_def(id, fn_def_data, ITEM_LIKE_SPACE, span);
return self.with_parent(fn_def, |this| {
this.create_def(return_impl_trait_id, DefPathData::ImplTrait, REGULAR_SPACE, span);
this.create_def(*return_impl_trait_id, DefPathData::ImplTrait, REGULAR_SPACE, span);
visit::walk_generics(this, generics);
visit::walk_fn_decl(this, decl);
let closure_def = this.create_def(closure_id,
DefPathData::ClosureExpr,
REGULAR_SPACE,
span);
// Walk the generated arguments for the `async fn`.
for a in arguments {
use visit::Visitor;
this.visit_ty(&a.arg.ty);
}
// We do not invoke `walk_fn_decl` as this will walk the arguments that are being
// replaced.
visit::walk_fn_ret_ty(this, &decl.output);
let closure_def = this.create_def(
*closure_id, DefPathData::ClosureExpr, REGULAR_SPACE, span,
);
this.with_parent(closure_def, |this| {
visit::walk_block(this, body);
for a in arguments {
use visit::Visitor;
// Walk each of the generated statements before the regular block body.
this.visit_stmt(&a.stmt);
}
visit::walk_block(this, &body);
})
})
}
@ -290,7 +305,7 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
match expr.node {
ExprKind::Mac(..) => return self.visit_macro_invoc(expr.id),
ExprKind::Closure(_, asyncness, ..) => {
ExprKind::Closure(_, ref asyncness, ..) => {
let closure_def = self.create_def(expr.id,
DefPathData::ClosureExpr,
REGULAR_SPACE,
@ -300,7 +315,7 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
// Async closures desugar to closures inside of closures, so
// we must create two defs.
if let IsAsync::Async { closure_id, .. } = asyncness {
let async_def = self.create_def(closure_id,
let async_def = self.create_def(*closure_id,
DefPathData::ClosureExpr,
REGULAR_SPACE,
expr.span);

31
src/librustc/hir/mod.rs
View file

@ -1583,6 +1583,17 @@ pub enum LocalSource {
Normal,
/// A desugared `for _ in _ { .. }` loop.
ForLoopDesugar,
/// When lowering async functions, we create locals within the `async move` so that
/// all arguments are dropped after the future is polled.
///
/// ```ignore (pseudo-Rust)
/// async fn foo(<pattern> @ x: Type) {
/// async move {
/// let <pattern> = x;
/// }
/// }
/// ```
AsyncFn,
}
/// Hints at the original code for a `match _ { .. }`.
@ -1883,6 +1894,26 @@ pub struct InlineAsm {
pub struct Arg {
pub pat: P<Pat>,
pub hir_id: HirId,
pub source: ArgSource,
}
impl Arg {
/// Returns the pattern representing the original binding for this argument.
pub fn original_pat(&self) -> &P<Pat> {
match &self.source {
ArgSource::Normal => &self.pat,
ArgSource::AsyncFn(pat) => &pat,
}
}
}
/// Represents the source of an argument in a function header.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
pub enum ArgSource {
/// Argument as specified by the user.
Normal,
/// Generated argument from `async fn` lowering, contains the original binding pattern.
AsyncFn(P<Pat>),
}
/// Represents the header (not the body) of a function declaration.

15
src/librustc/infer/error_reporting/nice_region_error/different_lifetimes.rs
View file

@ -86,19 +86,16 @@ impl<'a, 'gcx, 'tcx> NiceRegionError<'a, 'gcx, 'tcx> {
let sub_is_ret_type =
self.is_return_type_anon(scope_def_id_sub, bregion_sub, ty_fndecl_sub);
let span_label_var1 = if let Some(simple_ident) = anon_arg_sup.pat.simple_ident() {
format!(" from `{}`", simple_ident)
} else {
String::new()
let span_label_var1 = match anon_arg_sup.original_pat().simple_ident() {
Some(simple_ident) => format!(" from `{}`", simple_ident),
None => String::new(),
};
let span_label_var2 = if let Some(simple_ident) = anon_arg_sub.pat.simple_ident() {
format!(" into `{}`", simple_ident)
} else {
String::new()
let span_label_var2 = match anon_arg_sub.original_pat().simple_ident() {
Some(simple_ident) => format!(" into `{}`", simple_ident),
None => String::new(),
};
let (span_1, span_2, main_label, span_label) = match (sup_is_ret_type, sub_is_ret_type) {
(None, None) => {
let (main_label_1, span_label_1) = if ty_sup.hir_id == ty_sub.hir_id {

9
src/librustc/infer/error_reporting/nice_region_error/named_anon_conflict.rs
View file

@ -95,13 +95,12 @@ impl<'a, 'gcx, 'tcx> NiceRegionError<'a, 'gcx, 'tcx> {
}
}
let (error_var, span_label_var) = if let Some(simple_ident) = arg.pat.simple_ident() {
(
let (error_var, span_label_var) = match arg.original_pat().simple_ident() {
Some(simple_ident) => (
format!("the type of `{}`", simple_ident),
format!("the type of `{}`", simple_ident),
)
} else {
("parameter type".to_owned(), "type".to_owned())
),
None => ("parameter type".to_owned(), "type".to_owned()),
};
let mut diag = struct_span_err!(

19
src/librustc/lint/context.rs
View file

@ -1326,6 +1326,25 @@ impl<'a, T: EarlyLintPass> ast_visit::Visitor<'a> for EarlyContextAndPass<'a, T>
run_early_pass!(self, check_mac, mac);
}
fn visit_fn_header(&mut self, header: &'a ast::FnHeader) {
// Unlike in HIR lowering and name resolution, the `AsyncArgument` statements are not added
// to the function body and the arguments do not replace those in the declaration. They are
// still visited manually here so that buffered lints can be emitted.
if let ast::IsAsync::Async { ref arguments, .. } = header.asyncness.node {
for a in arguments {
// Visit the argument..
self.visit_pat(&a.arg.pat);
if let ast::ArgSource::AsyncFn(pat) = &a.arg.source {
self.visit_pat(pat);
}
self.visit_ty(&a.arg.ty);
// ..and the statement.
self.visit_stmt(&a.stmt);
}
}
}
}
struct LateLintPassObjects<'a> {

2
src/librustc/middle/resolve_lifetime.rs
View file

@ -2421,7 +2421,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
let help_name = if let Some(body) = parent {
let arg = &self.tcx.hir().body(body).arguments[index];
format!("`{}`", self.tcx.hir().hir_to_pretty_string(arg.pat.hir_id))
format!("`{}`", self.tcx.hir().hir_to_pretty_string(arg.original_pat().hir_id))
} else {
format!("argument {}", index + 1)
};

1
src/librustc_mir/hair/pattern/check_match.rs
View file

@ -76,6 +76,7 @@ impl<'a, 'tcx> Visitor<'tcx> for MatchVisitor<'a, 'tcx> {
self.check_irrefutable(&loc.pat, match loc.source {
hir::LocalSource::Normal => "local binding",
hir::LocalSource::ForLoopDesugar => "`for` loop binding",
hir::LocalSource::AsyncFn => "async fn binding",
});
// Check legality of move bindings and `@` patterns.

6
src/librustc_passes/ast_validation.rs
View file

@ -222,7 +222,7 @@ impl<'a> AstValidator<'a> {
}
}
fn check_trait_fn_not_async(&self, span: Span, asyncness: IsAsync) {
fn check_trait_fn_not_async(&self, span: Span, asyncness: &IsAsync) {
if asyncness.is_async() {
struct_span_err!(self.session, span, E0706,
"trait fns cannot be declared `async`").emit()
@ -570,7 +570,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
self.invalid_visibility(&impl_item.vis, None);
if let ImplItemKind::Method(ref sig, _) = impl_item.node {
self.check_trait_fn_not_const(sig.header.constness);
self.check_trait_fn_not_async(impl_item.span, sig.header.asyncness.node);
self.check_trait_fn_not_async(impl_item.span, &sig.header.asyncness.node);
}
}
}
@ -642,7 +642,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
self.no_questions_in_bounds(bounds, "supertraits", true);
for trait_item in trait_items {
if let TraitItemKind::Method(ref sig, ref block) = trait_item.node {
self.check_trait_fn_not_async(trait_item.span, sig.header.asyncness.node);
self.check_trait_fn_not_async(trait_item.span, &sig.header.asyncness.node);
self.check_trait_fn_not_const(sig.header.constness);
if block.is_none() {
self.check_decl_no_pat(&sig.decl, |span, mut_ident| {

20
src/librustc_privacy/lib.rs
View file

@ -948,6 +948,16 @@ impl<'a, 'tcx> Visitor<'tcx> for NamePrivacyVisitor<'a, 'tcx> {
intravisit::walk_pat(self, pat);
}
fn visit_argument_source(&mut self, s: &'tcx hir::ArgSource) {
match s {
// Don't visit the pattern in `ArgSource::AsyncFn`, it contains a pattern which has
// a `NodeId` w/out a type, as it is only used for getting the name of the original
// pattern for diagnostics where only an `hir::Arg` is present.
hir::ArgSource::AsyncFn(..) => {},
_ => intravisit::walk_argument_source(self, s),
}
}
}
////////////////////////////////////////////////////////////////////////////////////////////
@ -1133,6 +1143,16 @@ impl<'a, 'tcx> Visitor<'tcx> for TypePrivacyVisitor<'a, 'tcx> {
intravisit::walk_pat(self, pattern);
}
fn visit_argument_source(&mut self, s: &'tcx hir::ArgSource) {
match s {
// Don't visit the pattern in `ArgSource::AsyncFn`, it contains a pattern which has
// a `NodeId` w/out a type, as it is only used for getting the name of the original
// pattern for diagnostics where only an `hir::Arg` is present.
hir::ArgSource::AsyncFn(..) => {},
_ => intravisit::walk_argument_source(self, s),
}
}
fn visit_local(&mut self, local: &'tcx hir::Local) {
if let Some(ref init) = local.init {
if self.check_expr_pat_type(init.hir_id, init.span) {

36
src/librustc_resolve/lib.rs
View file

@ -817,13 +817,13 @@ impl<'a, 'tcx> Visitor<'tcx> for Resolver<'a> {
debug!("(resolving function) entering function");
let (rib_kind, asyncness) = match function_kind {
FnKind::ItemFn(_, ref header, ..) =>
(FnItemRibKind, header.asyncness.node),
(FnItemRibKind, &header.asyncness.node),
FnKind::Method(_, ref sig, _, _) =>
(TraitOrImplItemRibKind, sig.header.asyncness.node),
(TraitOrImplItemRibKind, &sig.header.asyncness.node),
FnKind::Closure(_) =>
// Async closures aren't resolved through `visit_fn`-- they're
// processed separately
(ClosureRibKind(node_id), IsAsync::NotAsync),
(ClosureRibKind(node_id), &IsAsync::NotAsync),
};
// Create a value rib for the function.
@ -834,26 +834,42 @@ impl<'a, 'tcx> Visitor<'tcx> for Resolver<'a> {
// Add each argument to the rib.
let mut bindings_list = FxHashMap::default();
for argument in &declaration.inputs {
let mut add_argument = |argument: &ast::Arg| {
self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list);
self.visit_ty(&argument.ty);
debug!("(resolving function) recorded argument");
};
// Walk the generated async arguments if this is an `async fn`, otherwise walk the
// normal arguments.
if let IsAsync::Async { ref arguments, .. } = asyncness {
for a in arguments { add_argument(&a.arg); }
} else {
for a in &declaration.inputs { add_argument(a); }
}
visit::walk_fn_ret_ty(self, &declaration.output);
// Resolve the function body, potentially inside the body of an async closure
if let IsAsync::Async { closure_id, .. } = asyncness {
let rib_kind = ClosureRibKind(closure_id);
let rib_kind = ClosureRibKind(*closure_id);
self.ribs[ValueNS].push(Rib::new(rib_kind));
self.label_ribs.push(Rib::new(rib_kind));
}
match function_kind {
FnKind::ItemFn(.., body) |
FnKind::Method(.., body) => {
self.visit_block(body);
FnKind::ItemFn(.., body) | FnKind::Method(.., body) => {
if let IsAsync::Async { ref arguments, .. } = asyncness {
let mut body = body.clone();
// Insert the generated statements into the body before attempting to
// resolve names.
for a in arguments {
body.stmts.insert(0, a.stmt.clone());
}
self.visit_block(&body);
} else {
self.visit_block(body);
}
}
FnKind::Closure(body) => {
self.visit_expr(body);

2
src/librustc_save_analysis/sig.rs
View file

@ -374,7 +374,7 @@ impl Sig for ast::Item {
Ok(extend_sig(ty, text, defs, vec![]))
}
ast::ItemKind::Fn(ref decl, header, ref generics, _) => {
ast::ItemKind::Fn(ref decl, ref header, ref generics, _) => {
let mut text = String::new();
if header.constness.node == ast::Constness::Const {
text.push_str("const ");

10
src/librustc_typeck/check/mod.rs
View file

@ -1005,6 +1005,16 @@ impl<'a, 'gcx, 'tcx> Visitor<'gcx> for GatherLocalsVisitor<'a, 'gcx, 'tcx> {
// Don't descend into the bodies of nested closures
fn visit_fn(&mut self, _: intravisit::FnKind<'gcx>, _: &'gcx hir::FnDecl,
_: hir::BodyId, _: Span, _: hir::HirId) { }
fn visit_argument_source(&mut self, s: &'gcx hir::ArgSource) {
match s {
// Don't visit the pattern in `ArgSource::AsyncFn`, it contains a pattern which has
// a `NodeId` w/out a type, as it is only used for getting the name of the original
// pattern for diagnostics where only an `hir::Arg` is present.
hir::ArgSource::AsyncFn(..) => {},
_ => intravisit::walk_argument_source(self, s),
}
}
}
/// When `check_fn` is invoked on a generator (i.e., a body that

10
src/librustc_typeck/check/writeback.rs
View file

@ -297,6 +297,16 @@ impl<'cx, 'gcx, 'tcx> Visitor<'gcx> for WritebackCx<'cx, 'gcx, 'tcx> {
let ty = self.resolve(&ty, &hir_ty.span);
self.write_ty_to_tables(hir_ty.hir_id, ty);
}
fn visit_argument_source(&mut self, s: &'gcx hir::ArgSource) {
match s {
// Don't visit the pattern in `ArgSource::AsyncFn`, it contains a pattern which has
// a `NodeId` w/out a type, as it is only used for getting the name of the original
// pattern for diagnostics where only an `hir::Arg` is present.
hir::ArgSource::AsyncFn(..) => {},
_ => intravisit::walk_argument_source(self, s),
}
}
}
impl<'cx, 'gcx, 'tcx> WritebackCx<'cx, 'gcx, 'tcx> {

2
src/librustdoc/clean/mod.rs
View file

@ -2017,7 +2017,7 @@ impl<'a> Clean<Arguments> for (&'a [hir::Ty], hir::BodyId) {
Arguments {
values: self.0.iter().enumerate().map(|(i, ty)| {
Argument {
name: name_from_pat(&body.arguments[i].pat),
name: name_from_pat(&body.arguments[i].original_pat()),
type_: ty.clean(cx),
}
}).collect()

51
src/libsyntax/ast.rs
View file

@ -888,6 +888,17 @@ pub struct Local {
pub id: NodeId,
pub span: Span,
pub attrs: ThinVec<Attribute>,
/// Origin of this local variable.
pub source: LocalSource,
}
#[derive(Clone, Copy, RustcEncodable, RustcDecodable, Debug)]
pub enum LocalSource {
/// Local was parsed from source.
Normal,
/// Within `ast::IsAsync::Async`, a local is generated that will contain the moved arguments
/// of an `async fn`.
AsyncFn,
}
/// An arm of a 'match'.
@ -1725,6 +1736,16 @@ pub struct Arg {
pub ty: P<Ty>,
pub pat: P<Pat>,
pub id: NodeId,
pub source: ArgSource,
}
/// The source of an argument in a function header.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum ArgSource {
/// Argument as written by the user.
Normal,
/// Argument from `async fn` lowering, contains the original binding pattern.
AsyncFn(P<Pat>),
}
/// Alternative representation for `Arg`s describing `self` parameter of methods.
@ -1784,6 +1805,7 @@ impl Arg {
}),
ty,
id: DUMMY_NODE_ID,
source: ArgSource::Normal,
};
match eself.node {
SelfKind::Explicit(ty, mutbl) => arg(mutbl, ty),
@ -1838,18 +1860,35 @@ pub enum Unsafety {
Normal,
}
#[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug)]
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct AsyncArgument {
/// `__arg0`
pub ident: Ident,
/// `__arg0: <ty>` argument to replace existing function argument `<pat>: <ty>`.
pub arg: Arg,
/// `let <pat>: <ty> = __arg0;` statement to be inserted at the start of the block.
pub stmt: Stmt,
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum IsAsync {
Async {
closure_id: NodeId,
return_impl_trait_id: NodeId,
/// This field stores the arguments and statements that are used in HIR lowering to
/// ensure that `async fn` arguments are dropped at the correct time.
///
/// The argument and statements here are generated at parse time as they are required in
/// both the hir lowering, def collection and name resolution and this stops them needing
/// to be created in each place.
arguments: Vec<AsyncArgument>,
},
NotAsync,
}
impl IsAsync {
pub fn is_async(self) -> bool {
if let IsAsync::Async { .. } = self {
pub fn is_async(&self) -> bool {
if let IsAsync::Async { .. } = *self {
true
} else {
false
@ -1857,12 +1896,12 @@ impl IsAsync {
}
/// In ths case this is an `async` return, the `NodeId` for the generated `impl Trait` item.
pub fn opt_return_id(self) -> Option<NodeId> {
pub fn opt_return_id(&self) -> Option<NodeId> {
match self {
IsAsync::Async {
return_impl_trait_id,
..
} => Some(return_impl_trait_id),
} => Some(*return_impl_trait_id),
IsAsync::NotAsync => None,
}
}
@ -2202,7 +2241,7 @@ impl Item {
///
/// All the information between the visibility and the name of the function is
/// included in this struct (e.g., `async unsafe fn` or `const extern "C" fn`).
#[derive(Clone, Copy, RustcEncodable, RustcDecodable, Debug)]
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct FnHeader {
pub unsafety: Unsafety,
pub asyncness: Spanned<IsAsync>,

6
src/libsyntax/ext/build.rs
View file

@ -526,6 +526,7 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
id: ast::DUMMY_NODE_ID,
span: sp,
attrs: ThinVec::new(),
source: ast::LocalSource::Normal,
});
ast::Stmt {
id: ast::DUMMY_NODE_ID,
@ -554,6 +555,7 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
id: ast::DUMMY_NODE_ID,
span: sp,
attrs: ThinVec::new(),
source: ast::LocalSource::Normal,
});
ast::Stmt {
id: ast::DUMMY_NODE_ID,
@ -571,6 +573,7 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
id: ast::DUMMY_NODE_ID,
span,
attrs: ThinVec::new(),
source: ast::LocalSource::Normal,
});
ast::Stmt {
id: ast::DUMMY_NODE_ID,
@ -976,7 +979,8 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
ast::Arg {
ty,
pat: arg_pat,
id: ast::DUMMY_NODE_ID
id: ast::DUMMY_NODE_ID,
source: ast::ArgSource::Normal,
}
}

20
src/libsyntax/ext/placeholders.rs
View file

@ -102,6 +102,13 @@ impl<'a, 'b> PlaceholderExpander<'a, 'b> {
fn remove(&mut self, id: ast::NodeId) -> AstFragment {
self.expanded_fragments.remove(&id).unwrap()
}
fn next_id(&mut self, id: &mut ast::NodeId) {
if self.monotonic {
assert_eq!(*id, ast::DUMMY_NODE_ID);
*id = self.cx.resolver.next_node_id()
}
}
}
impl<'a, 'b> MutVisitor for PlaceholderExpander<'a, 'b> {
@ -183,9 +190,16 @@ impl<'a, 'b> MutVisitor for PlaceholderExpander<'a, 'b> {
noop_visit_block(block, self);
for stmt in block.stmts.iter_mut() {
if self.monotonic {
assert_eq!(stmt.id, ast::DUMMY_NODE_ID);
stmt.id = self.cx.resolver.next_node_id();
self.next_id(&mut stmt.id);
}
}
fn visit_asyncness(&mut self, a: &mut ast::IsAsync) {
noop_visit_asyncness(a, self);
if let ast::IsAsync::Async { ref mut arguments, .. } = a {
for argument in arguments.iter_mut() {
self.next_id(&mut argument.stmt.id);
}
}
}

34
src/libsyntax/mut_visit.rs
View file

@ -208,6 +208,10 @@ pub trait MutVisitor: Sized {
noop_visit_local(l, self);
}
fn visit_local_source(&mut self, l: &mut LocalSource) {
noop_visit_local_source(l, self);
}
fn visit_mac(&mut self, _mac: &mut Mac) {
panic!("visit_mac disabled by default");
// N.B., see note about macros above. If you really want a visitor that
@ -231,6 +235,10 @@ pub trait MutVisitor: Sized {
noop_visit_arg(a, self);
}
fn visit_arg_source(&mut self, a: &mut ArgSource) {
noop_visit_arg_source(a, self);
}
fn visit_generics(&mut self, generics: &mut Generics) {
noop_visit_generics(generics, self);
}
@ -511,13 +519,17 @@ pub fn noop_visit_parenthesized_parameter_data<T: MutVisitor>(args: &mut Parenth
}
pub fn noop_visit_local<T: MutVisitor>(local: &mut P<Local>, vis: &mut T) {
let Local { id, pat, ty, init, span, attrs } = local.deref_mut();
let Local { id, pat, ty, init, span, attrs, source } = local.deref_mut();
vis.visit_id(id);
vis.visit_pat(pat);
visit_opt(ty, |ty| vis.visit_ty(ty));
visit_opt(init, |init| vis.visit_expr(init));
vis.visit_span(span);
visit_thin_attrs(attrs, vis);
vis.visit_local_source(source);
}
pub fn noop_visit_local_source<T: MutVisitor>(_local_source: &mut LocalSource, _vis: &mut T) {
}
pub fn noop_visit_attribute<T: MutVisitor>(attr: &mut Attribute, vis: &mut T) {
@ -556,10 +568,18 @@ pub fn noop_visit_meta_item<T: MutVisitor>(mi: &mut MetaItem, vis: &mut T) {
vis.visit_span(span);
}
pub fn noop_visit_arg<T: MutVisitor>(Arg { id, pat, ty }: &mut Arg, vis: &mut T) {
pub fn noop_visit_arg<T: MutVisitor>(Arg { id, pat, ty, source }: &mut Arg, vis: &mut T) {
vis.visit_id(id);
vis.visit_pat(pat);
vis.visit_ty(ty);
vis.visit_arg_source(source);
}
pub fn noop_visit_arg_source<T: MutVisitor>(source: &mut ArgSource, vis: &mut T) {
match source {
ArgSource::Normal => {},
ArgSource::AsyncFn(pat) => vis.visit_pat(pat),
}
}
pub fn noop_visit_tt<T: MutVisitor>(tt: &mut TokenTree, vis: &mut T) {
@ -671,9 +691,17 @@ pub fn noop_visit_interpolated<T: MutVisitor>(nt: &mut token::Nonterminal, vis:
pub fn noop_visit_asyncness<T: MutVisitor>(asyncness: &mut IsAsync, vis: &mut T) {
match asyncness {
IsAsync::Async { closure_id, return_impl_trait_id } => {
IsAsync::Async { closure_id, return_impl_trait_id, ref mut arguments } => {
vis.visit_id(closure_id);
vis.visit_id(return_impl_trait_id);
for AsyncArgument { ident, arg, stmt } in arguments.iter_mut() {
vis.visit_ident(ident);
vis.visit_arg(arg);
visit_clobber(stmt, |stmt| {
vis.flat_map_stmt(stmt)
.expect_one("expected visitor to produce exactly one item")
});
}
}
IsAsync::NotAsync => {}
}

87
src/libsyntax/parse/parser.rs
View file

@ -1,7 +1,7 @@
use crate::ast::{AngleBracketedArgs, ParenthesizedArgs, AttrStyle, BareFnTy};
use crate::ast::{AngleBracketedArgs, AsyncArgument, ParenthesizedArgs, AttrStyle, BareFnTy};
use crate::ast::{GenericBound, TraitBoundModifier};
use crate::ast::Unsafety;
use crate::ast::{Mod, AnonConst, Arg, Arm, Guard, Attribute, BindingMode, TraitItemKind};
use crate::ast::{Mod, AnonConst, Arg, ArgSource, Arm, Guard, Attribute, BindingMode, TraitItemKind};
use crate::ast::Block;
use crate::ast::{BlockCheckMode, CaptureBy, Movability};
use crate::ast::{Constness, Crate};
@ -14,7 +14,7 @@ use crate::ast::{GenericParam, GenericParamKind};
use crate::ast::GenericArg;
use crate::ast::{Ident, ImplItem, IsAsync, IsAuto, Item, ItemKind};
use crate::ast::{Label, Lifetime, Lit, LitKind};
use crate::ast::Local;
use crate::ast::{Local, LocalSource};
use crate::ast::MacStmtStyle;
use crate::ast::{Mac, Mac_, MacDelimiter};
use crate::ast::{MutTy, Mutability};
@ -550,7 +550,7 @@ fn dummy_arg(span: Span) -> Arg {
span,
id: ast::DUMMY_NODE_ID
};
Arg { ty: P(ty), pat: pat, id: ast::DUMMY_NODE_ID }
Arg { ty: P(ty), pat: pat, id: ast::DUMMY_NODE_ID, source: ast::ArgSource::Normal }
}
#[derive(Copy, Clone, Debug)]
@ -1517,6 +1517,7 @@ impl<'a> Parser<'a> {
IsAsync::Async {
closure_id: ast::DUMMY_NODE_ID,
return_impl_trait_id: ast::DUMMY_NODE_ID,
arguments: Vec::new(),
}
} else {
IsAsync::NotAsync
@ -1575,7 +1576,7 @@ impl<'a> Parser<'a> {
// trait item macro.
(keywords::Invalid.ident(), ast::TraitItemKind::Macro(mac), ast::Generics::default())
} else {
let (constness, unsafety, asyncness, abi) = self.parse_fn_front_matter()?;
let (constness, unsafety, mut asyncness, abi) = self.parse_fn_front_matter()?;
let ident = self.parse_ident()?;
let mut generics = self.parse_generics()?;
@ -1589,6 +1590,7 @@ impl<'a> Parser<'a> {
p.parse_arg_general(p.span.rust_2018(), true, false)
})?;
generics.where_clause = self.parse_where_clause()?;
self.construct_async_arguments(&mut asyncness, &d);
let sig = ast::MethodSig {
header: FnHeader {
@ -2124,7 +2126,7 @@ impl<'a> Parser<'a> {
}
};
Ok(Arg { ty, pat, id: ast::DUMMY_NODE_ID })
Ok(Arg { ty, pat, id: ast::DUMMY_NODE_ID, source: ast::ArgSource::Normal })
}
/// Parses a single function argument.
@ -2147,7 +2149,8 @@ impl<'a> Parser<'a> {
Ok(Arg {
ty: t,
pat,
id: ast::DUMMY_NODE_ID
id: ast::DUMMY_NODE_ID,
source: ast::ArgSource::Normal,
})
}
@ -5029,6 +5032,7 @@ impl<'a> Parser<'a> {
id: ast::DUMMY_NODE_ID,
span: lo.to(hi),
attrs,
source: LocalSource::Normal,
}))
}
@ -6566,7 +6570,7 @@ impl<'a> Parser<'a> {
/// Parses an item-position function declaration.
fn parse_item_fn(&mut self,
unsafety: Unsafety,
asyncness: Spanned<IsAsync>,
mut asyncness: Spanned<IsAsync>,
constness: Spanned<Constness>,
abi: Abi)
-> PResult<'a, ItemInfo> {
@ -6575,6 +6579,7 @@ impl<'a> Parser<'a> {
let decl = self.parse_fn_decl(allow_c_variadic)?;
generics.where_clause = self.parse_where_clause()?;
let (inner_attrs, body) = self.parse_inner_attrs_and_block()?;
self.construct_async_arguments(&mut asyncness, &decl);
let header = FnHeader { unsafety, asyncness, constness, abi };
Ok((ident, ItemKind::Fn(decl, header, generics, body), Some(inner_attrs)))
}
@ -6755,11 +6760,12 @@ impl<'a> Parser<'a> {
Ok((keywords::Invalid.ident(), vec![], ast::Generics::default(),
ast::ImplItemKind::Macro(mac)))
} else {
let (constness, unsafety, asyncness, abi) = self.parse_fn_front_matter()?;
let (constness, unsafety, mut asyncness, abi) = self.parse_fn_front_matter()?;
let ident = self.parse_ident()?;
let mut generics = self.parse_generics()?;
let decl = self.parse_fn_decl_with_self(|p| p.parse_arg())?;
generics.where_clause = self.parse_where_clause()?;
self.construct_async_arguments(&mut asyncness, &decl);
*at_end = true;
let (inner_attrs, body) = self.parse_inner_attrs_and_block()?;
let header = ast::FnHeader { abi, unsafety, constness, asyncness };
@ -8181,6 +8187,7 @@ impl<'a> Parser<'a> {
respan(async_span, IsAsync::Async {
closure_id: ast::DUMMY_NODE_ID,
return_impl_trait_id: ast::DUMMY_NODE_ID,
arguments: Vec::new(),
}),
respan(fn_span, Constness::NotConst),
Abi::Rust)?;
@ -8826,6 +8833,68 @@ impl<'a> Parser<'a> {
}
}
}
/// When lowering a `async fn` to the HIR, we need to move all of the arguments of the function
/// into the generated closure so that they are dropped when the future is polled and not when
/// it is created.
///
/// The arguments of the function are replaced in HIR lowering with the arguments created by
/// this function and the statements created here are inserted at the top of the closure body.
fn construct_async_arguments(&mut self, asyncness: &mut Spanned<IsAsync>, decl: &FnDecl) {
if let IsAsync::Async { ref mut arguments, .. } = asyncness.node {
for (index, input) in decl.inputs.iter().enumerate() {
let id = ast::DUMMY_NODE_ID;
let span = input.pat.span;
// Construct a name for our temporary argument.
let name = format!("__arg{}", index);
let ident = Ident::from_str(&name);
// Construct an argument representing `__argN: <ty>` to replace the argument of the
// async function.
let arg = Arg {
ty: input.ty.clone(),
id,
pat: P(Pat {
id,
node: PatKind::Ident(
BindingMode::ByValue(Mutability::Immutable), ident, None,
),
span,
}),
source: ArgSource::AsyncFn(input.pat.clone()),
};
// Construct a `let <pat> = __argN;` statement to insert at the top of the
// async closure.
let local = P(Local {
pat: input.pat.clone(),
// We explicitly do not specify the type for this statement. When the user's
// argument type is `impl Trait` then this would require the
// `impl_trait_in_bindings` feature to also be present for that same type to
// be valid in this binding. At the time of writing (13 Mar 19),
// `impl_trait_in_bindings` is not stable.
ty: None,
init: Some(P(Expr {
id,
node: ExprKind::Path(None, ast::Path {
span,
segments: vec![PathSegment { ident, id, args: None }],
}),
span,
attrs: ThinVec::new(),
})),
id,
span,
attrs: ThinVec::new(),
source: LocalSource::AsyncFn,
});
let stmt = Stmt { id, node: StmtKind::Local(local), span, };
arguments.push(AsyncArgument { ident, arg, stmt });
}
}
}
}
pub fn emit_unclosed_delims(unclosed_delims: &mut Vec<UnmatchedBrace>, handler: &errors::Handler) {

23
src/libsyntax/print/pprust.rs
View file

@ -372,7 +372,7 @@ pub fn vis_to_string(v: &ast::Visibility) -> String {
}
pub fn fun_to_string(decl: &ast::FnDecl,
header: ast::FnHeader,
header: &ast::FnHeader,
name: ast::Ident,
generics: &ast::Generics)
-> String {
@ -1133,7 +1133,7 @@ impl<'a> State<'a> {
match item.node {
ast::ForeignItemKind::Fn(ref decl, ref generics) => {
self.head("")?;
self.print_fn(decl, ast::FnHeader::default(),
self.print_fn(decl, &ast::FnHeader::default(),
Some(item.ident),
generics, &item.vis)?;
self.end()?; // end head-ibox
@ -1263,7 +1263,7 @@ impl<'a> State<'a> {
self.s.word(";")?;
self.end()?; // end the outer cbox
}
ast::ItemKind::Fn(ref decl, header, ref param_names, ref body) => {
ast::ItemKind::Fn(ref decl, ref header, ref param_names, ref body) => {
self.head("")?;
self.print_fn(
decl,
@ -1615,7 +1615,7 @@ impl<'a> State<'a> {
vis: &ast::Visibility)
-> io::Result<()> {
self.print_fn(&m.decl,
m.header,
&m.header,
Some(ident),
&generics,
vis)
@ -2213,7 +2213,7 @@ impl<'a> State<'a> {
self.bclose_(expr.span, INDENT_UNIT)?;
}
ast::ExprKind::Closure(
capture_clause, asyncness, movability, ref decl, ref body, _) => {
capture_clause, ref asyncness, movability, ref decl, ref body, _) => {
self.print_movability(movability)?;
self.print_asyncness(asyncness)?;
self.print_capture_clause(capture_clause)?;
@ -2798,7 +2798,7 @@ impl<'a> State<'a> {
pub fn print_fn(&mut self,
decl: &ast::FnDecl,
header: ast::FnHeader,
header: &ast::FnHeader,
name: Option<ast::Ident>,
generics: &ast::Generics,
vis: &ast::Visibility) -> io::Result<()> {
@ -2853,8 +2853,7 @@ impl<'a> State<'a> {
}
}
pub fn print_asyncness(&mut self, asyncness: ast::IsAsync)
-> io::Result<()> {
pub fn print_asyncness(&mut self, asyncness: &ast::IsAsync) -> io::Result<()> {
if asyncness.is_async() {
self.word_nbsp("async")?;
}
@ -3126,7 +3125,7 @@ impl<'a> State<'a> {
span: syntax_pos::DUMMY_SP,
};
self.print_fn(decl,
ast::FnHeader { unsafety, abi, ..ast::FnHeader::default() },
&ast::FnHeader { unsafety, abi, ..ast::FnHeader::default() },
name,
&generics,
&source_map::dummy_spanned(ast::VisibilityKind::Inherited))?;
@ -3189,7 +3188,7 @@ impl<'a> State<'a> {
}
pub fn print_fn_header_info(&mut self,
header: ast::FnHeader,
header: &ast::FnHeader,
vis: &ast::Visibility) -> io::Result<()> {
self.s.word(visibility_qualified(vis, ""))?;
@ -3198,7 +3197,7 @@ impl<'a> State<'a> {
ast::Constness::Const => self.word_nbsp("const")?
}
self.print_asyncness(header.asyncness.node)?;
self.print_asyncness(&header.asyncness.node)?;
self.print_unsafety(header.unsafety)?;
if header.abi != Abi::Rust {
@ -3247,7 +3246,7 @@ mod tests {
assert_eq!(
fun_to_string(
&decl,
ast::FnHeader {
&ast::FnHeader {
unsafety: ast::Unsafety::Normal,
constness: source_map::dummy_spanned(ast::Constness::NotConst),
asyncness: source_map::dummy_spanned(ast::IsAsync::NotAsync),

3
src/libsyntax/visit.rs
View file

@ -544,6 +544,9 @@ pub fn walk_fn_ret_ty<'a, V: Visitor<'a>>(visitor: &mut V, ret_ty: &'a FunctionR
pub fn walk_fn_decl<'a, V: Visitor<'a>>(visitor: &mut V, function_declaration: &'a FnDecl) {
for argument in &function_declaration.inputs {
visitor.visit_pat(&argument.pat);
if let ArgSource::AsyncFn(pat) = &argument.source {
visitor.visit_pat(pat);
}
visitor.visit_ty(&argument.ty)
}
visitor.visit_fn_ret_ty(&function_declaration.output)

1
src/libsyntax_ext/deriving/debug.rs
View file

@ -128,6 +128,7 @@ fn stmt_let_undescore(cx: &mut ExtCtxt<'_>, sp: Span, expr: P<ast::Expr>) -> ast
id: ast::DUMMY_NODE_ID,
span: sp,
attrs: ThinVec::new(),
source: ast::LocalSource::Normal,
});
ast::Stmt {
id: ast::DUMMY_NODE_ID,

2
src/test/mir-opt/inline-closure-borrows-arg.rs
View file

@ -20,7 +20,7 @@ fn foo<T: Copy>(_t: T, q: &i32) -> i32 {
// ...
// bb0: {
// ...
// _3 = [closure@HirId { owner: DefIndex(0:4), local_id: 29 }];
// _3 = [closure@HirId { owner: DefIndex(0:4), local_id: 31 }];
// ...
// _4 = &_3;
// ...

2
src/test/mir-opt/inline-closure.rs
View file

@ -16,7 +16,7 @@ fn foo<T: Copy>(_t: T, q: i32) -> i32 {
// ...
// bb0: {
// ...
// _3 = [closure@HirId { owner: DefIndex(0:4), local_id: 13 }];
// _3 = [closure@HirId { owner: DefIndex(0:4), local_id: 15 }];
// ...
// _4 = &_3;
// ...

184
src/test/run-pass/issue-54716.rs Normal file
View file

@ -0,0 +1,184 @@
// aux-build:arc_wake.rs
// edition:2018
// run-pass
#![allow(unused_variables)]
#![feature(async_await, await_macro, futures_api)]
extern crate arc_wake;
use arc_wake::ArcWake;
use std::cell::RefCell;
use std::future::Future;
use std::marker::PhantomData;
use std::sync::Arc;
use std::rc::Rc;
use std::task::Context;
struct EmptyWaker;
impl ArcWake for EmptyWaker {
fn wake(self: Arc<Self>) {}
}
#[derive(Debug, Eq, PartialEq)]
enum DropOrder {
Function,
Val(&'static str),
}
type DropOrderListPtr = Rc<RefCell<Vec<DropOrder>>>;
struct D(&'static str, DropOrderListPtr);
impl Drop for D {
fn drop(&mut self) {
self.1.borrow_mut().push(DropOrder::Val(self.0));
}
}
/// Check that unused bindings are dropped after the function is polled.
async fn foo(x: D, _y: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
/// Check that underscore patterns are dropped after the function is polled.
async fn bar(x: D, _: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
/// Check that underscore patterns within more complex patterns are dropped after the function
/// is polled.
async fn baz((x, _): (D, D)) {
x.1.borrow_mut().push(DropOrder::Function);
}
/// Check that underscore and unused bindings within and outwith more complex patterns are dropped
/// after the function is polled.
async fn foobar(x: D, (a, _, _c): (D, D, D), _: D, _y: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
struct Foo;
impl Foo {
/// Check that unused bindings are dropped after the method is polled.
async fn foo(x: D, _y: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
/// Check that underscore patterns are dropped after the method is polled.
async fn bar(x: D, _: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
/// Check that underscore patterns within more complex patterns are dropped after the method
/// is polled.
async fn baz((x, _): (D, D)) {
x.1.borrow_mut().push(DropOrder::Function);
}
/// Check that underscore and unused bindings within and outwith more complex patterns are
/// dropped after the method is polled.
async fn foobar(x: D, (a, _, _c): (D, D, D), _: D, _y: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
}
struct Bar<'a>(PhantomData<&'a ()>);
impl<'a> Bar<'a> {
/// Check that unused bindings are dropped after the method with self is polled.
async fn foo(&'a self, x: D, _y: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
/// Check that underscore patterns are dropped after the method with self is polled.
async fn bar(&'a self, x: D, _: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
/// Check that underscore patterns within more complex patterns are dropped after the method
/// with self is polled.
async fn baz(&'a self, (x, _): (D, D)) {
x.1.borrow_mut().push(DropOrder::Function);
}
/// Check that underscore and unused bindings within and outwith more complex patterns are
/// dropped after the method with self is polled.
async fn foobar(&'a self, x: D, (a, _, _c): (D, D, D), _: D, _y: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
}
fn assert_drop_order_after_poll<Fut: Future<Output = ()>>(
f: impl FnOnce(DropOrderListPtr) -> Fut,
expected_order: &[DropOrder],
) {
let empty = Arc::new(EmptyWaker);
let waker = ArcWake::into_waker(empty);
let mut cx = Context::from_waker(&waker);
let actual_order = Rc::new(RefCell::new(Vec::new()));
let mut fut = Box::pin(f(actual_order.clone()));
let _ = fut.as_mut().poll(&mut cx);
assert_eq!(*actual_order.borrow(), expected_order);
}
fn main() {
use DropOrder::*;
// At time of writing (23/04/19), the `bar` and `foobar` tests do not output the same order as
// the equivalent non-async functions. This is because the drop order of captured variables
// doesn't match the drop order of arguments in a function.
// Free functions (see doc comment on function for what it tests).
assert_drop_order_after_poll(|l| foo(D("x", l.clone()), D("_y", l.clone())),
&[Function, Val("_y"), Val("x")]);
assert_drop_order_after_poll(|l| bar(D("x", l.clone()), D("_", l.clone())),
&[Function, Val("x"), Val("_")]);
assert_drop_order_after_poll(|l| baz((D("x", l.clone()), D("_", l.clone()))),
&[Function, Val("x"), Val("_")]);
assert_drop_order_after_poll(|l| {
foobar(
D("x", l.clone()),
(D("a", l.clone()), D("_", l.clone()), D("_c", l.clone())),
D("_", l.clone()),
D("_y", l.clone()),
)
}, &[Function, Val("_y"), Val("_c"), Val("a"), Val("x"), Val("_"), Val("_")]);
// Methods w/out self (see doc comment on function for what it tests).
assert_drop_order_after_poll(|l| Foo::foo(D("x", l.clone()), D("_y", l.clone())),
&[Function, Val("_y"), Val("x")]);
assert_drop_order_after_poll(|l| Foo::bar(D("x", l.clone()), D("_", l.clone())),
&[Function, Val("x"), Val("_")]);
assert_drop_order_after_poll(|l| Foo::baz((D("x", l.clone()), D("_", l.clone()))),
&[Function, Val("x"), Val("_")]);
assert_drop_order_after_poll(|l| {
Foo::foobar(
D("x", l.clone()),
(D("a", l.clone()), D("_", l.clone()), D("_c", l.clone())),
D("_", l.clone()),
D("_y", l.clone()),
)
}, &[Function, Val("_y"), Val("_c"), Val("a"), Val("x"), Val("_"), Val("_")]);
// Methods (see doc comment on function for what it tests).
let b = Bar(Default::default());
assert_drop_order_after_poll(|l| b.foo(D("x", l.clone()), D("_y", l.clone())),
&[Function, Val("_y"), Val("x")]);
assert_drop_order_after_poll(|l| b.bar(D("x", l.clone()), D("_", l.clone())),
&[Function, Val("x"), Val("_")]);
assert_drop_order_after_poll(|l| b.baz((D("x", l.clone()), D("_", l.clone()))),
&[Function, Val("x"), Val("_")]);
assert_drop_order_after_poll(|l| {
b.foobar(
D("x", l.clone()),
(D("a", l.clone()), D("_", l.clone()), D("_c", l.clone())),
D("_", l.clone()),
D("_y", l.clone()),
)
}, &[Function, Val("_y"), Val("_c"), Val("a"), Val("x"), Val("_"), Val("_")]);
}