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thread through an implicit region body of the fn body

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This commit is contained in:
Niko Matsakis 2017-12-04 05:40:43 -05:00
parent 154cd94197
commit c7cfa2367b
20 changed files with 135 additions and 45 deletions
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2
src/librustc_mir/borrow_check/nll/mod.rs
View file

@ -78,11 +78,13 @@ pub(in borrow_check) fn compute_regions<'cx, 'gcx, 'tcx>(
// Run the MIR type-checker.
let mir_node_id = infcx.tcx.hir.as_local_node_id(def_id).unwrap();
let liveness = &LivenessResults::compute(mir);
let fr_fn_body = infcx.tcx.mk_region(ty::ReVar(universal_regions.fr_fn_body));
let constraint_sets = &type_check::type_check(
infcx,
mir_node_id,
param_env,
mir,
fr_fn_body,
&liveness,
flow_inits,
move_data,

4
src/librustc_mir/borrow_check/nll/region_infer/mod.rs
View file

@ -439,6 +439,8 @@ impl<'tcx> RegionInferenceContext<'tcx> {
/// have no evidence that `'b` outlives `'a`, so we want to report
/// an error.
fn check_type_tests(&self, infcx: &InferCtxt<'_, '_, 'tcx>, mir: &Mir<'tcx>) {
let tcx = infcx.tcx;
for type_test in &self.type_tests {
debug!("check_type_test: {:?}", type_test);
@ -452,7 +454,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
}
// Oh the humanity. Obviously we will do better than this error eventually.
infcx.tcx.sess.span_err(
tcx.sess.span_err(
type_test.span,
&format!("failed type test: {:?}", type_test),
);

28
src/librustc_mir/borrow_check/nll/type_check/mod.rs
View file

@ -51,13 +51,19 @@ pub(crate) fn type_check<'gcx, 'tcx>(
body_id: ast::NodeId,
param_env: ty::ParamEnv<'gcx>,
mir: &Mir<'tcx>,
implicit_region_bound: ty::Region<'tcx>,
liveness: &LivenessResults,
flow_inits: &mut FlowAtLocation<MaybeInitializedLvals<'_, 'gcx, 'tcx>>,
move_data: &MoveData<'tcx>,
) -> MirTypeckRegionConstraints<'tcx> {
type_check_internal(infcx, body_id, param_env, mir, &mut |cx| {
liveness::generate(cx, mir, liveness, flow_inits, move_data)
})
type_check_internal(
infcx,
body_id,
param_env,
mir,
Some(implicit_region_bound),
&mut |cx| liveness::generate(cx, mir, liveness, flow_inits, move_data),
)
}
fn type_check_internal<'gcx, 'tcx>(
@ -65,9 +71,10 @@ fn type_check_internal<'gcx, 'tcx>(
body_id: ast::NodeId,
param_env: ty::ParamEnv<'gcx>,
mir: &Mir<'tcx>,
implicit_region_bound: Option<ty::Region<'tcx>>,
extra: &mut FnMut(&mut TypeChecker<'_, 'gcx, 'tcx>),
) -> MirTypeckRegionConstraints<'tcx> {
let mut checker = TypeChecker::new(infcx, body_id, param_env);
let mut checker = TypeChecker::new(infcx, body_id, param_env, implicit_region_bound);
let errors_reported = {
let mut verifier = TypeVerifier::new(&mut checker, mir);
verifier.visit_mir(mir);
@ -535,6 +542,7 @@ struct TypeChecker<'a, 'gcx: 'a + 'tcx, 'tcx: 'a> {
param_env: ty::ParamEnv<'gcx>,
last_span: Span,
body_id: ast::NodeId,
implicit_region_bound: Option<ty::Region<'tcx>>,
reported_errors: FxHashSet<(Ty<'tcx>, Span)>,
constraints: MirTypeckRegionConstraints<'tcx>,
}
@ -588,12 +596,14 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> {
infcx: &'a InferCtxt<'a, 'gcx, 'tcx>,
body_id: ast::NodeId,
param_env: ty::ParamEnv<'gcx>,
implicit_region_bound: Option<ty::Region<'tcx>>,
) -> Self {
TypeChecker {
infcx,
last_span: DUMMY_SP,
body_id,
param_env,
implicit_region_bound,
reported_errors: FxHashSet(),
constraints: MirTypeckRegionConstraints::default(),
}
@ -618,8 +628,12 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> {
span_mirbug!(self, "", "errors selecting obligation: {:?}", e);
}
self.infcx
.process_registered_region_obligations(&[], None, self.param_env, self.body_id);
self.infcx.process_registered_region_obligations(
&[],
self.implicit_region_bound,
self.param_env,
self.body_id,
);
let data = self.infcx.take_and_reset_region_constraints();
if !data.is_empty() {
@ -1501,7 +1515,7 @@ impl MirPass for TypeckMir {
}
let param_env = tcx.param_env(def_id);
tcx.infer_ctxt().enter(|infcx| {
let _ = type_check_internal(&infcx, id, param_env, mir, &mut |_| ());
let _ = type_check_internal(&infcx, id, param_env, mir, None, &mut |_| ());
// For verification purposes, we just ignore the resulting
// region constraint sets. Not our problem. =)

15
src/librustc_mir/borrow_check/nll/universal_regions.rs
View file

@ -45,6 +45,11 @@ pub struct UniversalRegions<'tcx> {
/// The vid assigned to `'static`
pub fr_static: RegionVid,
/// A special region vid created to represent the current MIR fn
/// body. It will outlive the entire CFG but it will not outlive
/// any other universal regions.
pub fr_fn_body: RegionVid,
/// We create region variables such that they are ordered by their
/// `RegionClassification`. The first block are globals, then
/// externals, then locals. So things from:
@ -408,6 +413,7 @@ impl<'cx, 'gcx, 'tcx> UniversalRegionsBuilder<'cx, 'gcx, 'tcx> {
let first_local_index = self.infcx.num_region_vars();
let inputs_and_output = self.infcx
.replace_bound_regions_with_nll_infer_vars(FR, &bound_inputs_and_output);
let fr_fn_body = self.infcx.next_nll_region_var(FR).to_region_vid();
let num_universals = self.infcx.num_region_vars();
// Insert the facts we know from the predicates. Why? Why not.
@ -419,12 +425,16 @@ impl<'cx, 'gcx, 'tcx> UniversalRegionsBuilder<'cx, 'gcx, 'tcx> {
self.add_implied_bounds(&indices, ty);
}
// Finally, outlives is reflexive, and static outlives every
// other free region.
// Finally:
// - outlives is reflexive, so `'r: 'r` for every region `'r`
// - `'static: 'r` for every region `'r`
// - `'r: 'fn_body` for every (other) universally quantified
// region `'r`, all of which are provided by our caller
for fr in (FIRST_GLOBAL_INDEX..num_universals).map(RegionVid::new) {
debug!("build: relating free region {:?} to itself and to 'static", fr);
self.relations.relate_universal_regions(fr, fr);
self.relations.relate_universal_regions(fr_static, fr);
self.relations.relate_universal_regions(fr, fr_fn_body);
}
let (output_ty, input_tys) = inputs_and_output.split_last().unwrap();
@ -445,6 +455,7 @@ impl<'cx, 'gcx, 'tcx> UniversalRegionsBuilder<'cx, 'gcx, 'tcx> {
UniversalRegions {
indices,
fr_static,
fr_fn_body,
first_extern_index,
first_local_index,
num_universals,

10
src/test/mir-opt/nll/named-lifetimes-basic.rs
View file

@ -27,16 +27,18 @@ fn main() {
// END RUST SOURCE
// START rustc.use_x.nll.0.mir
// | Free Region Mapping
// | '_#0r | Global | ['_#2r, '_#1r, '_#0r, '_#3r]
// | '_#1r | External | ['_#1r]
// | '_#2r | External | ['_#2r, '_#1r]
// | '_#3r | Local | ['_#3r]
// | '_#0r | Global | ['_#2r, '_#1r, '_#0r, '_#4r, '_#3r]
// | '_#1r | External | ['_#1r, '_#4r]
// | '_#2r | External | ['_#2r, '_#1r, '_#4r]
// | '_#3r | Local | ['_#4r, '_#3r]
// | '_#4r | Local | ['_#4r]
// |
// | Inferred Region Values
// | '_#0r | {'_#0r, bb0[0], bb0[1]}
// | '_#1r | {'_#1r, bb0[0], bb0[1]}
// | '_#2r | {'_#2r, bb0[0], bb0[1]}
// | '_#3r | {'_#3r, bb0[0], bb0[1]}
// | '_#4r | {'_#4r, bb0[0], bb0[1]}
// |
// ...
// fn use_x(_1: &'_#1r mut i32, _2: &'_#2r u32, _3: &'_#1r u32, _4: &'_#3r u32) -> bool {

8
src/test/mir-opt/nll/reborrow-basic.rs
View file

@ -28,11 +28,11 @@ fn main() {
// END RUST SOURCE
// START rustc.main.nll.0.mir
// | '_#6r | {bb0[6], bb0[7], bb0[8], bb0[9], bb0[10], bb0[11], bb0[12], bb0[13], bb0[14]}
// | '_#7r | {bb0[6], bb0[7], bb0[8], bb0[9], bb0[10], bb0[11], bb0[12], bb0[13], bb0[14]}
// ...
// | '_#8r | {bb0[11], bb0[12], bb0[13], bb0[14]}
// | '_#9r | {bb0[11], bb0[12], bb0[13], bb0[14]}
// ...
// let _2: &'_#6r mut i32;
// let _2: &'_#7r mut i32;
// ...
// let _4: &'_#8r mut i32;
// let _4: &'_#9r mut i32;
// END rustc.main.nll.0.mir

8
src/test/mir-opt/nll/region-liveness-basic.rs
View file

@ -31,15 +31,15 @@ fn main() {
// END RUST SOURCE
// START rustc.main.nll.0.mir
// | '_#1r | {bb2[0], bb2[1], bb3[0], bb3[1]}
// | '_#2r | {bb2[1], bb3[0], bb3[1]}
// | '_#2r | {bb2[0], bb2[1], bb3[0], bb3[1]}
// | '_#3r | {bb2[1], bb3[0], bb3[1]}
// ...
// let _2: &'_#2r usize;
// let _2: &'_#3r usize;
// END rustc.main.nll.0.mir
// START rustc.main.nll.0.mir
// bb2: {
// | Live variables on entry to bb2[0]: [_1, _3]
// _2 = &'_#1r _1[_3];
// _2 = &'_#2r _1[_3];
// | Live variables on entry to bb2[1]: [_2]
// switchInt(const true) -> [0u8: bb4, otherwise: bb3];
// }

4
src/test/mir-opt/nll/region-liveness-drop-may-dangle.rs
View file

@ -44,5 +44,7 @@ unsafe impl<#[may_dangle] T> Drop for Wrap<T> {
// END RUST SOURCE
// START rustc.main.nll.0.mir
// | '_#5r | {bb2[3], bb2[4], bb2[5], bb3[0], bb3[1]}
// | '_#6r | {bb2[3], bb2[4], bb2[5], bb3[0], bb3[1]}
// ...
// let _2: Wrap<&'_#6r usize>;
// END rustc.main.nll.0.mir

4
src/test/mir-opt/nll/region-liveness-drop-no-may-dangle.rs
View file

@ -46,5 +46,7 @@ impl<T> Drop for Wrap<T> {
// END RUST SOURCE
// START rustc.main.nll.0.mir
// | '_#5r | {bb2[3], bb2[4], bb2[5], bb3[0], bb3[1], bb3[2], bb4[0], bb5[0], bb5[1], bb5[2], bb6[0], bb7[0], bb7[1], bb8[0]}
// | '_#6r | {bb2[3], bb2[4], bb2[5], bb3[0], bb3[1], bb3[2], bb4[0], bb5[0], bb5[1], bb5[2], bb6[0], bb7[0], bb7[1], bb8[0]}
// ...
// let _2: Wrap<&'_#6r usize>;
// END rustc.main.nll.0.mir

12
src/test/mir-opt/nll/region-liveness-two-disjoint-uses.rs
View file

@ -36,14 +36,14 @@ fn main() {
// END RUST SOURCE
// START rustc.main.nll.0.mir
// | '_#1r | {bb2[0], bb2[1], bb3[0], bb3[1]}
// | '_#2r | {bb2[0], bb2[1], bb3[0], bb3[1]}
// ...
// | '_#3r | {bb8[1], bb8[2], bb8[3], bb8[4]}
// | '_#4r | {bb2[1], bb3[0], bb3[1], bb8[2], bb8[3], bb8[4]}
// | '_#4r | {bb8[1], bb8[2], bb8[3], bb8[4]}
// | '_#5r | {bb2[1], bb3[0], bb3[1], bb8[2], bb8[3], bb8[4]}
// ...
// let mut _2: &'_#4r usize;
// let mut _2: &'_#5r usize;
// ...
// _2 = &'_#1r _1[_3];
// _2 = &'_#2r _1[_3];
// ...
// _2 = &'_#3r (*_10);
// _2 = &'_#4r (*_10);
// END rustc.main.nll.0.mir

12
src/test/mir-opt/nll/region-subtyping-basic.rs
View file

@ -32,16 +32,16 @@ fn main() {
// END RUST SOURCE
// START rustc.main.nll.0.mir
// | '_#1r | {bb2[0], bb2[1], bb2[2], bb2[3], bb2[4], bb2[5], bb2[6], bb3[0], bb3[1]}
// | '_#2r | {bb2[1], bb2[2], bb2[3], bb2[4], bb2[5], bb2[6], bb3[0], bb3[1]}
// | '_#3r | {bb2[5], bb2[6], bb3[0], bb3[1]}
// | '_#2r | {bb2[0], bb2[1], bb2[2], bb2[3], bb2[4], bb2[5], bb2[6], bb3[0], bb3[1]}
// | '_#3r | {bb2[1], bb2[2], bb2[3], bb2[4], bb2[5], bb2[6], bb3[0], bb3[1]}
// | '_#4r | {bb2[5], bb2[6], bb3[0], bb3[1]}
// END rustc.main.nll.0.mir
// START rustc.main.nll.0.mir
// let _2: &'_#2r usize;
// let _2: &'_#3r usize;
// ...
// let _6: &'_#3r usize;
// let _6: &'_#4r usize;
// ...
// _2 = &'_#1r _1[_3];
// _2 = &'_#2r _1[_3];
// ...
// _7 = _2;
// ...

2
src/test/ui/nll/capture-ref-in-struct.stderr
View file

@ -7,7 +7,7 @@ error[E0597]: `y` does not live long enough
37 | }
| - borrowed value only lives until here
|
= note: borrowed value must be valid for lifetime '_#4r...
= note: borrowed value must be valid for lifetime '_#5r...
error: aborting due to previous error

2
src/test/ui/nll/closure-requirements/escape-argument.stderr
View file

@ -32,7 +32,7 @@ error[E0597]: `y` does not live long enough
39 | }
| - borrowed value only lives until here
|
= note: borrowed value must be valid for lifetime '_#5r...
= note: borrowed value must be valid for lifetime '_#6r...
error: aborting due to previous error

2
src/test/ui/nll/closure-requirements/escape-upvar-nested.stderr
View file

@ -59,7 +59,7 @@ error[E0597]: `y` does not live long enough
36 | }
| - borrowed value only lives until here
|
= note: borrowed value must be valid for lifetime '_#3r...
= note: borrowed value must be valid for lifetime '_#4r...
error: aborting due to previous error

2
src/test/ui/nll/closure-requirements/escape-upvar-ref.stderr
View file

@ -36,7 +36,7 @@ error[E0597]: `y` does not live long enough
36 | }
| - borrowed value only lives until here
|
= note: borrowed value must be valid for lifetime '_#3r...
= note: borrowed value must be valid for lifetime '_#4r...
error: aborting due to previous error

2
src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-comparing-against-free.stderr
View file

@ -79,7 +79,7 @@ error[E0597]: `a` does not live long enough
49 | }
| - borrowed value only lives until here
|
= note: borrowed value must be valid for lifetime '_#1r...
= note: borrowed value must be valid for lifetime '_#2r...
error: aborting due to 2 previous errors

4
src/test/ui/nll/ty-outlives/projection-fn.stderr
View file

@ -10,13 +10,13 @@ warning: not reporting region error due to -Znll
40 | Box::new(x.next())
| ^^^^^^^^^^^^^^^^^^
error: failed type test: TypeTest { generic_kind: ProjectionTy { substs: Slice([T]), item_def_id: DefId(2/0:1695 ~ core[2633]::iter[0]::iterator[0]::Iterator[0]::Item[0]) }, lower_bound: '_#3r, point: bb5[0], span: $DIR/projection-fn.rs:24:5: 24:23, test: IsOutlivedByAnyRegionIn([]) }
error: failed type test: TypeTest { generic_kind: ProjectionTy { substs: Slice([T]), item_def_id: DefId(2/0:1695 ~ core[2633]::iter[0]::iterator[0]::Iterator[0]::Item[0]) }, lower_bound: '_#4r, point: bb5[0], span: $DIR/projection-fn.rs:24:5: 24:23, test: IsOutlivedByAnyRegionIn(['_#2r]) }
--> $DIR/projection-fn.rs:24:5
|
24 | Box::new(x.next())
| ^^^^^^^^^^^^^^^^^^
error: failed type test: TypeTest { generic_kind: ProjectionTy { substs: Slice([T]), item_def_id: DefId(2/0:1695 ~ core[2633]::iter[0]::iterator[0]::Iterator[0]::Item[0]) }, lower_bound: '_#4r, point: bb5[0], span: $DIR/projection-fn.rs:40:5: 40:23, test: IsOutlivedByAnyRegionIn(['_#2r]) }
error: failed type test: TypeTest { generic_kind: ProjectionTy { substs: Slice([T]), item_def_id: DefId(2/0:1695 ~ core[2633]::iter[0]::iterator[0]::Iterator[0]::Item[0]) }, lower_bound: '_#5r, point: bb5[0], span: $DIR/projection-fn.rs:40:5: 40:23, test: IsOutlivedByAnyRegionIn(['_#2r, '_#3r]) }
--> $DIR/projection-fn.rs:40:5
|
40 | Box::new(x.next())

41
src/test/ui/nll/ty-outlives/ty-param-fn-body.rs Normal file
View file

@ -0,0 +1,41 @@
// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
// compile-flags:-Znll -Zborrowck=mir
// Test that we assume that universal types like `T` outlive the
// function body.
#![allow(warnings)]
#![feature(dyn_trait)]
use std::cell::Cell;
// No errors here, because `'a` is local to the body.
fn region_within_body<T>(t: T) {
let some_int = 22;
let cell = Cell::new(&some_int);
outlives(cell, t)
}
// Error here, because T: 'a is not satisfied.
fn region_static<'a, T>(cell: Cell<&'a usize>, t: T) {
outlives(cell, t)
//~^ WARNING not reporting region error due to -Znll
//~| ERROR failed type test
}
fn outlives<'a, T>(x: Cell<&'a usize>, y: T)
where
T: 'a,
{
}
fn main() {}

14
src/test/ui/nll/ty-outlives/ty-param-fn-body.stderr Normal file
View file

@ -0,0 +1,14 @@
warning: not reporting region error due to -Znll
--> $DIR/ty-param-fn-body.rs:30:5
|
30 | outlives(cell, t)
| ^^^^^^^^
error: failed type test: TypeTest { generic_kind: T/#0, lower_bound: '_#4r, point: bb0[4], span: $DIR/ty-param-fn-body.rs:30:5: 30:22, test: IsOutlivedByAnyRegionIn(['_#2r]) }
--> $DIR/ty-param-fn-body.rs:30:5
|
30 | outlives(cell, t)
| ^^^^^^^^^^^^^^^^^
error: aborting due to previous error

4
src/test/ui/nll/ty-outlives/ty-param-fn.stderr
View file

@ -10,13 +10,13 @@ warning: not reporting region error due to -Znll
38 | x
| ^
error: failed type test: TypeTest { generic_kind: T/#1, lower_bound: '_#2r, point: bb0[3], span: $DIR/ty-param-fn.rs:22:5: 22:6, test: IsOutlivedByAnyRegionIn([]) }
error: failed type test: TypeTest { generic_kind: T/#1, lower_bound: '_#3r, point: bb0[3], span: $DIR/ty-param-fn.rs:22:5: 22:6, test: IsOutlivedByAnyRegionIn(['_#2r]) }
--> $DIR/ty-param-fn.rs:22:5
|
22 | x
| ^
error: failed type test: TypeTest { generic_kind: T/#2, lower_bound: '_#3r, point: bb0[3], span: $DIR/ty-param-fn.rs:38:5: 38:6, test: IsOutlivedByAnyRegionIn(['_#2r]) }
error: failed type test: TypeTest { generic_kind: T/#2, lower_bound: '_#4r, point: bb0[3], span: $DIR/ty-param-fn.rs:38:5: 38:6, test: IsOutlivedByAnyRegionIn(['_#2r, '_#3r]) }
--> $DIR/ty-param-fn.rs:38:5
|
38 | x