Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Query generator kind for error reporting #65277

Merged
merged 1 commit into from
Oct 12, 2019
Merged

Query generator kind for error reporting #65277

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 4 additions & 0 deletions src/librustc/hir/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1366,6 +1366,10 @@ impl Body {
hir_id: self.value.hir_id,
}
}

pub fn generator_kind(&self) -> Option<GeneratorKind> {
self.generator_kind
}
}

/// The type of source expression that caused this generator to be created.
Expand Down
30 changes: 22 additions & 8 deletions src/librustc_mir/borrow_check/conflict_errors.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,6 @@
use rustc::hir;
use rustc::hir::def_id::DefId;
use rustc::hir::{AsyncGeneratorKind, GeneratorKind};
use rustc::mir::{
self, AggregateKind, BindingForm, BorrowKind, ClearCrossCrate, ConstraintCategory, Local,
LocalDecl, LocalKind, Location, Operand, Place, PlaceBase, PlaceRef, ProjectionElem, Rvalue,
Expand Down Expand Up @@ -788,7 +789,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
..
},
) if borrow_spans.for_closure() => self.report_escaping_closure_capture(
borrow_spans.args_or_use(),
borrow_spans,
borrow_span,
region_name,
category,
Expand All @@ -806,7 +807,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
},

) if borrow_spans.for_generator() => self.report_escaping_closure_capture(
borrow_spans.args_or_use(),
borrow_spans,
borrow_span,
region_name,
category,
Expand Down Expand Up @@ -1195,15 +1196,15 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {

fn report_escaping_closure_capture(
&mut self,
args_span: Span,
use_span: UseSpans,
var_span: Span,
fr_name: &RegionName,
category: ConstraintCategory,
constraint_span: Span,
captured_var: &str,
) -> DiagnosticBuilder<'cx> {
let tcx = self.infcx.tcx;

let args_span = use_span.args_or_use();
let mut err = self.cannot_capture_in_long_lived_closure(
args_span,
captured_var,
Expand All @@ -1223,12 +1224,25 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
},
Err(_) => "move |<args>| <body>".to_string()
};

let kind = match use_span.generator_kind() {
Some(generator_kind) => match generator_kind {
GeneratorKind::Async(async_kind) => match async_kind {
AsyncGeneratorKind::Block => "async block",
AsyncGeneratorKind::Closure => "async closure",
_ => bug!("async block/closure expected, but async funtion found."),
},
GeneratorKind::Gen => "generator",
}
None => "closure",
};
err.span_suggestion(
args_span,
&format!("to force the closure to take ownership of {} (and any \
other referenced variables), use the `move` keyword",
captured_var),
&format!(
"to force the {} to take ownership of {} (and any \
other referenced variables), use the `move` keyword",
kind,
captured_var
),
suggestion,
Applicability::MachineApplicable,
);
Expand Down
45 changes: 28 additions & 17 deletions src/librustc_mir/borrow_check/error_reporting.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
use rustc::hir;
use rustc::hir::def::Namespace;
use rustc::hir::def_id::DefId;
use rustc::hir::GeneratorKind;
use rustc::mir::{
AggregateKind, Constant, Field, Local, LocalKind, Location, Operand,
Place, PlaceBase, PlaceRef, ProjectionElem, Rvalue, Statement, StatementKind,
Expand All @@ -14,7 +15,7 @@ use syntax_pos::Span;
use syntax::symbol::sym;

use super::borrow_set::BorrowData;
use super::{MirBorrowckCtxt};
use super::MirBorrowckCtxt;
use crate::dataflow::move_paths::{InitLocation, LookupResult};

pub(super) struct IncludingDowncast(pub(super) bool);
Expand Down Expand Up @@ -604,7 +605,7 @@ pub(super) enum UseSpans {
// The access is caused by capturing a variable for a closure.
ClosureUse {
// This is true if the captured variable was from a generator.
is_generator: bool,
generator_kind: Option<GeneratorKind>,
// The span of the args of the closure, including the `move` keyword if
// it's present.
args_span: Span,
Expand All @@ -631,6 +632,13 @@ impl UseSpans {
}
}

pub(super) fn generator_kind(self) -> Option<GeneratorKind> {
match self {
UseSpans::ClosureUse { generator_kind, .. } => generator_kind,
_ => None,
}
}

// Add a span label to the arguments of the closure, if it exists.
pub(super) fn args_span_label(
self,
Expand All @@ -656,23 +664,23 @@ impl UseSpans {
/// Returns `false` if this place is not used in a closure.
pub(super) fn for_closure(&self) -> bool {
match *self {
UseSpans::ClosureUse { is_generator, .. } => !is_generator,
UseSpans::ClosureUse { generator_kind, .. } => generator_kind.is_none(),
_ => false,
}
}

/// Returns `false` if this place is not used in a generator.
pub(super) fn for_generator(&self) -> bool {
match *self {
UseSpans::ClosureUse { is_generator, .. } => is_generator,
UseSpans::ClosureUse { generator_kind, .. } => generator_kind.is_some(),
_ => false,
}
}

/// Describe the span associated with a use of a place.
pub(super) fn describe(&self) -> String {
match *self {
UseSpans::ClosureUse { is_generator, .. } => if is_generator {
UseSpans::ClosureUse { generator_kind, .. } => if generator_kind.is_some() {
" in generator".to_string()
} else {
" in closure".to_string()
Expand Down Expand Up @@ -794,19 +802,20 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
if let StatementKind::Assign(
box(_, Rvalue::Aggregate(ref kind, ref places))
) = stmt.kind {
let (def_id, is_generator) = match kind {
box AggregateKind::Closure(def_id, _) => (def_id, false),
box AggregateKind::Generator(def_id, _, _) => (def_id, true),
let def_id = match kind {
box AggregateKind::Closure(def_id, _)
| box AggregateKind::Generator(def_id, _, _) => def_id,
_ => return OtherUse(stmt.source_info.span),
};

debug!(
"move_spans: def_id={:?} is_generator={:?} places={:?}",
def_id, is_generator, places
"move_spans: def_id={:?} places={:?}",
def_id, places
);
if let Some((args_span, var_span)) = self.closure_span(*def_id, moved_place, places) {
if let Some((args_span, generator_kind, var_span))
= self.closure_span(*def_id, moved_place, places) {
return ClosureUse {
is_generator,
generator_kind,
args_span,
var_span,
};
Expand Down Expand Up @@ -857,11 +866,11 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
"borrow_spans: def_id={:?} is_generator={:?} places={:?}",
def_id, is_generator, places
);
if let Some((args_span, var_span)) = self.closure_span(
if let Some((args_span, generator_kind, var_span)) = self.closure_span(
*def_id, Place::from(target).as_ref(), places
) {
return ClosureUse {
is_generator,
generator_kind,
args_span,
var_span,
};
Expand All @@ -884,7 +893,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
def_id: DefId,
target_place: PlaceRef<'cx, 'tcx>,
places: &Vec<Operand<'tcx>>,
) -> Option<(Span, Span)> {
) -> Option<(Span, Option<GeneratorKind>, Span)> {
debug!(
"closure_span: def_id={:?} target_place={:?} places={:?}",
def_id, target_place, places
Expand All @@ -893,14 +902,16 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
let expr = &self.infcx.tcx.hir().expect_expr(hir_id).kind;
debug!("closure_span: hir_id={:?} expr={:?}", hir_id, expr);
if let hir::ExprKind::Closure(
.., args_span, _
.., body_id, args_span, _
) = expr {
for (upvar, place) in self.infcx.tcx.upvars(def_id)?.values().zip(places) {
match place {
Operand::Copy(place) |
Operand::Move(place) if target_place == place.as_ref() => {
debug!("closure_span: found captured local {:?}", place);
return Some((*args_span, upvar.span));
let body = self.infcx.tcx.hir().body(*body_id);
let generator_kind = body.generator_kind();
return Some((*args_span, generator_kind, upvar.span));
},
_ => {}
}
Expand Down
2 changes: 1 addition & 1 deletion src/test/ui/async-await/async-borrowck-escaping-block-error.stderr
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -12,7 +12,7 @@ note: generator is returned here
|
LL | fn foo() -> Box<impl std::future::Future<Output = u32>> {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: to force the closure to take ownership of `x` (and any other referenced variables), use the `move` keyword
help: to force the async block to take ownership of `x` (and any other referenced variables), use the `move` keyword
|
LL | Box::new(async move { x } )
| ^^^^^^^^^^
Expand Down