From 08a60ac6ed68628c4ccdb3fcbb6d780cadd7565a Mon Sep 17 00:00:00 2001
From: Matthew Jasper <mjjasper1@gmail.com>
Date: Sat, 21 Sep 2019 16:32:24 +0100
Subject: [PATCH 1/2] Calculate liveness for the same locals with and without
-Zpolonius
This fixes some test differences and also avoids overflow in
issue-38591.rs.
---
.../nll/type_check/liveness/local_use_map.rs | 4 +
.../nll/type_check/liveness/mod.rs | 52 +++---
.../nll/type_check/liveness/polonius.rs | 11 +-
.../nll/type_check/liveness/trace.rs | 37 ++++-
...wck-escaping-closure-error.polonius.stderr | 16 --
...k-escaping-closure-error-2.polonius.stderr | 16 --
...ref-mut-in-let-issue-46557.polonius.stderr | 59 -------
...al-binding-from-desugaring.polonius.stderr | 16 --
...phase-surprise-no-conflict.polonius.stderr | 148 ------------------
.../consts/promote_const_let.polonius.stderr | 29 ----
...dropck_trait_cycle_checked.polonius.stderr | 78 ---------
...escapes-but-not-over-yield.polonius.stderr | 20 ---
src/test/ui/nll/get_default.polonius.stderr | 5 +-
.../loan_ends_mid_block_pair.polonius.stderr | 15 --
.../nll/polonius/polonius-smoke-test.stderr | 4 +-
...return-ref-mut-issue-46557.polonius.stderr | 15 --
...ures-failed-recursive-fn-1.polonius.stderr | 60 -------
17 files changed, 84 insertions(+), 501 deletions(-)
delete mode 100644 src/test/ui/async-await/async-borrowck-escaping-closure-error.polonius.stderr
delete mode 100644 src/test/ui/borrowck/borrowck-escaping-closure-error-2.polonius.stderr
delete mode 100644 src/test/ui/borrowck/promote-ref-mut-in-let-issue-46557.polonius.stderr
delete mode 100644 src/test/ui/borrowck/return-local-binding-from-desugaring.polonius.stderr
delete mode 100644 src/test/ui/borrowck/two-phase-surprise-no-conflict.polonius.stderr
delete mode 100644 src/test/ui/consts/promote_const_let.polonius.stderr
delete mode 100644 src/test/ui/dropck/dropck_trait_cycle_checked.polonius.stderr
delete mode 100644 src/test/ui/generator/ref-escapes-but-not-over-yield.polonius.stderr
delete mode 100644 src/test/ui/nll/loan_ends_mid_block_pair.polonius.stderr
delete mode 100644 src/test/ui/nll/return-ref-mut-issue-46557.polonius.stderr
delete mode 100644 src/test/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1.polonius.stderr
diff --git a/src/librustc_mir/borrow_check/nll/type_check/liveness/local_use_map.rs b/src/librustc_mir/borrow_check/nll/type_check/liveness/local_use_map.rs
index 7689ece7066..7dee00b3eca 100644
--- a/src/librustc_mir/borrow_check/nll/type_check/liveness/local_use_map.rs
+++ b/src/librustc_mir/borrow_check/nll/type_check/liveness/local_use_map.rs
@@ -70,6 +70,10 @@ impl LocalUseMap {
appearances: IndexVec::new(),
};
+ if live_locals.is_empty() {
+ return local_use_map;
+ }
+
let mut locals_with_use_data: IndexVec<Local, bool> =
IndexVec::from_elem_n(false, body.local_decls.len());
live_locals.iter().for_each(|&local| locals_with_use_data[local] = true);
diff --git a/src/librustc_mir/borrow_check/nll/type_check/liveness/mod.rs b/src/librustc_mir/borrow_check/nll/type_check/liveness/mod.rs
index 3f2ec1ba970..a01b528833b 100644
--- a/src/librustc_mir/borrow_check/nll/type_check/liveness/mod.rs
+++ b/src/librustc_mir/borrow_check/nll/type_check/liveness/mod.rs
@@ -36,31 +36,39 @@ pub(super) fn generate<'tcx>(
) {
debug!("liveness::generate");
- let live_locals: Vec<Local> = if AllFacts::enabled(typeck.tcx()) {
- // If "dump facts from NLL analysis" was requested perform
- // the liveness analysis for all `Local`s. This case opens
- // the possibility of the variables being analyzed in `trace`
- // to be *any* `Local`, not just the "live" ones, so we can't
- // make any assumptions past this point as to the characteristics
- // of the `live_locals`.
- // FIXME: Review "live" terminology past this point, we should
- // not be naming the `Local`s as live.
- body.local_decls.indices().collect()
+ let free_regions = regions_that_outlive_free_regions(
+ typeck.infcx.num_region_vars(),
+ &typeck.borrowck_context.universal_regions,
+ &typeck.borrowck_context.constraints.outlives_constraints,
+ );
+ let live_locals = compute_live_locals(typeck.tcx(), &free_regions, body);
+ let facts_enabled = AllFacts::enabled(typeck.tcx());
+
+
+ let polonius_drop_used = if facts_enabled {
+ let mut drop_used = Vec::new();
+ polonius::populate_access_facts(
+ typeck,
+ body,
+ location_table,
+ move_data,
+ &mut drop_used,
+ );
+ Some(drop_used)
} else {
- let free_regions = {
- regions_that_outlive_free_regions(
- typeck.infcx.num_region_vars(),
- &typeck.borrowck_context.universal_regions,
- &typeck.borrowck_context.constraints.outlives_constraints,
- )
- };
- compute_live_locals(typeck.tcx(), &free_regions, body)
+ None
};
- if !live_locals.is_empty() {
- trace::trace(typeck, body, elements, flow_inits, move_data, live_locals);
-
- polonius::populate_access_facts(typeck, body, location_table, move_data);
+ if !live_locals.is_empty() || facts_enabled {
+ trace::trace(
+ typeck,
+ body,
+ elements,
+ flow_inits,
+ move_data,
+ live_locals,
+ polonius_drop_used,
+ );
}
}
diff --git a/src/librustc_mir/borrow_check/nll/type_check/liveness/polonius.rs b/src/librustc_mir/borrow_check/nll/type_check/liveness/polonius.rs
index e37ddbda4be..526ad7fb905 100644
--- a/src/librustc_mir/borrow_check/nll/type_check/liveness/polonius.rs
+++ b/src/librustc_mir/borrow_check/nll/type_check/liveness/polonius.rs
@@ -16,7 +16,7 @@ struct UseFactsExtractor<'me> {
var_defined: &'me mut VarPointRelations,
var_used: &'me mut VarPointRelations,
location_table: &'me LocationTable,
- var_drop_used: &'me mut VarPointRelations,
+ var_drop_used: &'me mut Vec<(Local, Location)>,
move_data: &'me MoveData<'me>,
path_accessed_at: &'me mut MovePathPointRelations,
}
@@ -39,7 +39,7 @@ impl UseFactsExtractor<'_> {
fn insert_drop_use(&mut self, local: Local, location: Location) {
debug!("LivenessFactsExtractor::insert_drop_use()");
- self.var_drop_used.push((local, self.location_to_index(location)));
+ self.var_drop_used.push((local, location));
}
fn insert_path_access(&mut self, path: MovePathIndex, location: Location) {
@@ -100,6 +100,7 @@ pub(super) fn populate_access_facts(
body: &Body<'tcx>,
location_table: &LocationTable,
move_data: &MoveData<'_>,
+ drop_used: &mut Vec<(Local, Location)>,
) {
debug!("populate_var_liveness_facts()");
@@ -107,12 +108,16 @@ pub(super) fn populate_access_facts(
UseFactsExtractor {
var_defined: &mut facts.var_defined,
var_used: &mut facts.var_used,
- var_drop_used: &mut facts.var_drop_used,
+ var_drop_used: drop_used,
path_accessed_at: &mut facts.path_accessed_at,
location_table,
move_data,
}
.visit_body(body);
+
+ facts.var_drop_used.extend(drop_used.iter().map(|&(local, location)| {
+ (local, location_table.mid_index(location))
+ }));
}
for (local, local_decl) in body.local_decls.iter_enumerated() {
diff --git a/src/librustc_mir/borrow_check/nll/type_check/liveness/trace.rs b/src/librustc_mir/borrow_check/nll/type_check/liveness/trace.rs
index 36482a7b135..eacc4d084db 100644
--- a/src/librustc_mir/borrow_check/nll/type_check/liveness/trace.rs
+++ b/src/librustc_mir/borrow_check/nll/type_check/liveness/trace.rs
@@ -13,7 +13,7 @@ use rustc::traits::query::type_op::outlives::DropckOutlives;
use rustc::traits::query::type_op::TypeOp;
use rustc::ty::{Ty, TypeFoldable};
use rustc_index::bit_set::HybridBitSet;
-use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use std::rc::Rc;
/// This is the heart of the liveness computation. For each variable X
@@ -37,6 +37,7 @@ pub(super) fn trace(
flow_inits: &mut FlowAtLocation<'tcx, MaybeInitializedPlaces<'_, 'tcx>>,
move_data: &MoveData<'tcx>,
live_locals: Vec<Local>,
+ polonius_drop_used: Option<Vec<(Local, Location)>>,
) {
debug!("trace()");
@@ -52,7 +53,13 @@ pub(super) fn trace(
drop_data: FxHashMap::default(),
};
- LivenessResults::new(cx).compute_for_all_locals(live_locals);
+ let mut results = LivenessResults::new(cx);
+
+ if let Some(drop_used) = polonius_drop_used {
+ results.add_extra_drop_facts(drop_used, live_locals.iter().copied().collect())
+ }
+
+ results.compute_for_all_locals(live_locals);
}
/// Contextual state for the type-liveness generator.
@@ -145,6 +152,32 @@ impl LivenessResults<'me, 'typeck, 'flow, 'tcx> {
}
}
+ /// Add extra drop facts needed for Polonius.
+ ///
+ /// Add facts for all locals with free regions, since regions may outlive
+ /// the function body only at certain nodes in the CFG.
+ fn add_extra_drop_facts(
+ &mut self,
+ drop_used: Vec<(Local, Location)>,
+ live_locals: FxHashSet<Local>,
+ ) {
+ let locations = HybridBitSet::new_empty(self.cx.elements.num_points());
+
+ for (local, location) in drop_used {
+ if !live_locals.contains(&local) {
+ let local_ty = self.cx.body.local_decls[local].ty;
+ if local_ty.has_free_regions() {
+ self.cx.add_drop_live_facts_for(
+ local,
+ local_ty,
+ &[location],
+ &locations,
+ );
+ }
+ }
+ }
+ }
+
/// Clear the value of fields that are "per local variable".
fn reset_local_state(&mut self) {
self.defs.clear();
diff --git a/src/test/ui/async-await/async-borrowck-escaping-closure-error.polonius.stderr b/src/test/ui/async-await/async-borrowck-escaping-closure-error.polonius.stderr
deleted file mode 100644
index 5f20367b6ab..00000000000
--- a/src/test/ui/async-await/async-borrowck-escaping-closure-error.polonius.stderr
+++ /dev/null
@@ -1,16 +0,0 @@
-error[E0597]: `x` does not live long enough
- --> $DIR/async-borrowck-escaping-closure-error.rs:5:24
- |
-LL | Box::new((async || x)())
- | -------------------^----
- | | | |
- | | | borrowed value does not live long enough
- | | value captured here
- | borrow later used here
-LL |
-LL | }
- | - `x` dropped here while still borrowed
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0597`.
diff --git a/src/test/ui/borrowck/borrowck-escaping-closure-error-2.polonius.stderr b/src/test/ui/borrowck/borrowck-escaping-closure-error-2.polonius.stderr
deleted file mode 100644
index 89af8764557..00000000000
--- a/src/test/ui/borrowck/borrowck-escaping-closure-error-2.polonius.stderr
+++ /dev/null
@@ -1,16 +0,0 @@
-error[E0597]: `books` does not live long enough
- --> $DIR/borrowck-escaping-closure-error-2.rs:11:17
- |
-LL | Box::new(|| books.push(4))
- | ------------^^^^^---------
- | | | |
- | | | borrowed value does not live long enough
- | | value captured here
- | borrow later used here
-LL |
-LL | }
- | - `books` dropped here while still borrowed
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0597`.
diff --git a/src/test/ui/borrowck/promote-ref-mut-in-let-issue-46557.polonius.stderr b/src/test/ui/borrowck/promote-ref-mut-in-let-issue-46557.polonius.stderr
deleted file mode 100644
index a5b2e876274..00000000000
--- a/src/test/ui/borrowck/promote-ref-mut-in-let-issue-46557.polonius.stderr
+++ /dev/null
@@ -1,59 +0,0 @@
-error[E0716]: temporary value dropped while borrowed
- --> $DIR/promote-ref-mut-in-let-issue-46557.rs:5:21
- |
-LL | let ref mut x = 1234543;
- | ^^^^^^^ creates a temporary which is freed while still in use
-LL | x
- | - borrow later used here
-LL | }
- | - temporary value is freed at the end of this statement
- |
- = note: consider using a `let` binding to create a longer lived value
-
-error[E0716]: temporary value dropped while borrowed
- --> $DIR/promote-ref-mut-in-let-issue-46557.rs:10:25
- |
-LL | let (ref mut x, ) = (1234543, );
- | ^^^^^^^^^^^ creates a temporary which is freed while still in use
-LL | x
- | - borrow later used here
-LL | }
- | - temporary value is freed at the end of this statement
- |
- = note: consider using a `let` binding to create a longer lived value
-
-error[E0515]: cannot return value referencing temporary value
- --> $DIR/promote-ref-mut-in-let-issue-46557.rs:15:5
- |
-LL | match 1234543 {
- | ^ ------- temporary value created here
- | _____|
- | |
-LL | | ref mut x => x
-LL | | }
- | |_____^ returns a value referencing data owned by the current function
-
-error[E0515]: cannot return value referencing temporary value
- --> $DIR/promote-ref-mut-in-let-issue-46557.rs:21:5
- |
-LL | match (123443,) {
- | ^ --------- temporary value created here
- | _____|
- | |
-LL | | (ref mut x,) => x,
-LL | | }
- | |_____^ returns a value referencing data owned by the current function
-
-error[E0515]: cannot return reference to temporary value
- --> $DIR/promote-ref-mut-in-let-issue-46557.rs:27:5
- |
-LL | &mut 1234543
- | ^^^^^-------
- | | |
- | | temporary value created here
- | returns a reference to data owned by the current function
-
-error: aborting due to 5 previous errors
-
-Some errors have detailed explanations: E0515, E0716.
-For more information about an error, try `rustc --explain E0515`.
diff --git a/src/test/ui/borrowck/return-local-binding-from-desugaring.polonius.stderr b/src/test/ui/borrowck/return-local-binding-from-desugaring.polonius.stderr
deleted file mode 100644
index c818379762c..00000000000
--- a/src/test/ui/borrowck/return-local-binding-from-desugaring.polonius.stderr
+++ /dev/null
@@ -1,16 +0,0 @@
-error[E0716]: temporary value dropped while borrowed
- --> $DIR/return-local-binding-from-desugaring.rs:26:18
- |
-LL | for ref x in xs {
- | ^^ creates a temporary which is freed while still in use
-...
-LL | }
- | - temporary value is freed at the end of this statement
-LL | result
- | ------ borrow later used here
- |
- = note: consider using a `let` binding to create a longer lived value
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0716`.
diff --git a/src/test/ui/borrowck/two-phase-surprise-no-conflict.polonius.stderr b/src/test/ui/borrowck/two-phase-surprise-no-conflict.polonius.stderr
deleted file mode 100644
index 7b246426a23..00000000000
--- a/src/test/ui/borrowck/two-phase-surprise-no-conflict.polonius.stderr
+++ /dev/null
@@ -1,148 +0,0 @@
-error[E0503]: cannot use `self.cx` because it was mutably borrowed
- --> $DIR/two-phase-surprise-no-conflict.rs:21:23
- |
-LL | let _mut_borrow = &mut *self;
- | ---------- borrow of `*self` occurs here
-LL | let _access = self.cx;
- | ^^^^^^^ use of borrowed `*self`
-LL |
-LL | _mut_borrow;
- | ----------- borrow later used here
-
-error[E0502]: cannot borrow `*self` as mutable because it is also borrowed as immutable
- --> $DIR/two-phase-surprise-no-conflict.rs:57:17
- |
-LL | self.hash_expr(&self.cx_mut.body(eid).value);
- | ^^^^^---------^^-----------^^^^^^^^^^^^^^^^^
- | | | |
- | | | immutable borrow occurs here
- | | immutable borrow later used by call
- | mutable borrow occurs here
-
-error[E0499]: cannot borrow `reg.sess_mut` as mutable more than once at a time
- --> $DIR/two-phase-surprise-no-conflict.rs:119:51
- |
-LL | reg.register_static(Box::new(TrivialPass::new(&mut reg.sess_mut)));
- | --- --------------- ^^^^^^^^^^^^^^^^^ second mutable borrow occurs here
- | | |
- | | first borrow later used by call
- | first mutable borrow occurs here
-
-error[E0499]: cannot borrow `reg.sess_mut` as mutable more than once at a time
- --> $DIR/two-phase-surprise-no-conflict.rs:122:54
- |
-LL | reg.register_bound(Box::new(TrivialPass::new_mut(&mut reg.sess_mut)));
- | --- -------------- ^^^^^^^^^^^^^^^^^ second mutable borrow occurs here
- | | |
- | | first borrow later used by call
- | first mutable borrow occurs here
-
-error[E0499]: cannot borrow `reg.sess_mut` as mutable more than once at a time
- --> $DIR/two-phase-surprise-no-conflict.rs:125:53
- |
-LL | reg.register_univ(Box::new(TrivialPass::new_mut(&mut reg.sess_mut)));
- | --- ------------- ^^^^^^^^^^^^^^^^^ second mutable borrow occurs here
- | | |
- | | first borrow later used by call
- | first mutable borrow occurs here
-
-error[E0499]: cannot borrow `reg.sess_mut` as mutable more than once at a time
- --> $DIR/two-phase-surprise-no-conflict.rs:128:44
- |
-LL | reg.register_ref(&TrivialPass::new_mut(&mut reg.sess_mut));
- | --- ------------ ^^^^^^^^^^^^^^^^^ second mutable borrow occurs here
- | | |
- | | first borrow later used by call
- | first mutable borrow occurs here
-
-error[E0502]: cannot borrow `*reg` as mutable because it is also borrowed as immutable
- --> $DIR/two-phase-surprise-no-conflict.rs:138:5
- |
-LL | reg.register_bound(Box::new(CapturePass::new(®.sess_mut)));
- | ^^^^--------------^^^^^^^^^^^^^^^^^^^^^^^^^^^-------------^^^
- | | | |
- | | | immutable borrow occurs here
- | | immutable borrow later used by call
- | mutable borrow occurs here
-
-error[E0502]: cannot borrow `*reg` as mutable because it is also borrowed as immutable
- --> $DIR/two-phase-surprise-no-conflict.rs:141:5
- |
-LL | reg.register_univ(Box::new(CapturePass::new(®.sess_mut)));
- | ^^^^-------------^^^^^^^^^^^^^^^^^^^^^^^^^^^-------------^^^
- | | | |
- | | | immutable borrow occurs here
- | | immutable borrow later used by call
- | mutable borrow occurs here
-
-error[E0502]: cannot borrow `*reg` as mutable because it is also borrowed as immutable
- --> $DIR/two-phase-surprise-no-conflict.rs:144:5
- |
-LL | reg.register_ref(&CapturePass::new(®.sess_mut));
- | ^^^^------------^^^^^^^^^^^^^^^^^^^-------------^^
- | | | |
- | | | immutable borrow occurs here
- | | immutable borrow later used by call
- | mutable borrow occurs here
-
-error[E0499]: cannot borrow `*reg` as mutable more than once at a time
- --> $DIR/two-phase-surprise-no-conflict.rs:154:5
- |
-LL | reg.register_bound(Box::new(CapturePass::new_mut(&mut reg.sess_mut)));
- | ^^^^--------------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^-----------------^^^
- | | | |
- | | | first mutable borrow occurs here
- | | first borrow later used by call
- | second mutable borrow occurs here
-
-error[E0499]: cannot borrow `reg.sess_mut` as mutable more than once at a time
- --> $DIR/two-phase-surprise-no-conflict.rs:154:54
- |
-LL | reg.register_bound(Box::new(CapturePass::new_mut(&mut reg.sess_mut)));
- | --- -------------- ^^^^^^^^^^^^^^^^^ second mutable borrow occurs here
- | | |
- | | first borrow later used by call
- | first mutable borrow occurs here
-
-error[E0499]: cannot borrow `*reg` as mutable more than once at a time
- --> $DIR/two-phase-surprise-no-conflict.rs:158:5
- |
-LL | reg.register_univ(Box::new(CapturePass::new_mut(&mut reg.sess_mut)));
- | ^^^^-------------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^-----------------^^^
- | | | |
- | | | first mutable borrow occurs here
- | | first borrow later used by call
- | second mutable borrow occurs here
-
-error[E0499]: cannot borrow `reg.sess_mut` as mutable more than once at a time
- --> $DIR/two-phase-surprise-no-conflict.rs:158:53
- |
-LL | reg.register_univ(Box::new(CapturePass::new_mut(&mut reg.sess_mut)));
- | --- ------------- ^^^^^^^^^^^^^^^^^ second mutable borrow occurs here
- | | |
- | | first borrow later used by call
- | first mutable borrow occurs here
-
-error[E0499]: cannot borrow `*reg` as mutable more than once at a time
- --> $DIR/two-phase-surprise-no-conflict.rs:162:5
- |
-LL | reg.register_ref(&CapturePass::new_mut(&mut reg.sess_mut));
- | ^^^^------------^^^^^^^^^^^^^^^^^^^^^^^-----------------^^
- | | | |
- | | | first mutable borrow occurs here
- | | first borrow later used by call
- | second mutable borrow occurs here
-
-error[E0499]: cannot borrow `reg.sess_mut` as mutable more than once at a time
- --> $DIR/two-phase-surprise-no-conflict.rs:162:44
- |
-LL | reg.register_ref(&CapturePass::new_mut(&mut reg.sess_mut));
- | --- ------------ ^^^^^^^^^^^^^^^^^ second mutable borrow occurs here
- | | |
- | | first borrow later used by call
- | first mutable borrow occurs here
-
-error: aborting due to 15 previous errors
-
-Some errors have detailed explanations: E0499, E0502, E0503.
-For more information about an error, try `rustc --explain E0499`.
diff --git a/src/test/ui/consts/promote_const_let.polonius.stderr b/src/test/ui/consts/promote_const_let.polonius.stderr
deleted file mode 100644
index cf41bd7bdb1..00000000000
--- a/src/test/ui/consts/promote_const_let.polonius.stderr
+++ /dev/null
@@ -1,29 +0,0 @@
-error[E0597]: `y` does not live long enough
- --> $DIR/promote_const_let.rs:4:9
- |
-LL | let x: &'static u32 = {
- | - borrow later stored here
-LL | let y = 42;
-LL | &y
- | ^^ borrowed value does not live long enough
-LL | };
- | - `y` dropped here while still borrowed
-
-error[E0716]: temporary value dropped while borrowed
- --> $DIR/promote_const_let.rs:6:28
- |
-LL | let x: &'static u32 = &{
- | ____________------------____^
- | | |
- | | type annotation requires that borrow lasts for `'static`
-LL | | let y = 42;
-LL | | y
-LL | | };
- | |_____^ creates a temporary which is freed while still in use
-LL | }
- | - temporary value is freed at the end of this statement
-
-error: aborting due to 2 previous errors
-
-Some errors have detailed explanations: E0597, E0716.
-For more information about an error, try `rustc --explain E0597`.
diff --git a/src/test/ui/dropck/dropck_trait_cycle_checked.polonius.stderr b/src/test/ui/dropck/dropck_trait_cycle_checked.polonius.stderr
deleted file mode 100644
index 5e93a023425..00000000000
--- a/src/test/ui/dropck/dropck_trait_cycle_checked.polonius.stderr
+++ /dev/null
@@ -1,78 +0,0 @@
-error[E0597]: `o2` does not live long enough
- --> $DIR/dropck_trait_cycle_checked.rs:111:13
- |
-LL | o1.set0(&o2);
- | ^^^ borrowed value does not live long enough
-...
-LL | }
- | -
- | |
- | `o2` dropped here while still borrowed
- | borrow might be used here, when `o1` is dropped and runs the destructor for type `std::boxed::Box<dyn Obj<'_>>`
- |
- = note: values in a scope are dropped in the opposite order they are defined
-
-error[E0597]: `o3` does not live long enough
- --> $DIR/dropck_trait_cycle_checked.rs:112:13
- |
-LL | o1.set1(&o3);
- | ^^^ borrowed value does not live long enough
-...
-LL | }
- | -
- | |
- | `o3` dropped here while still borrowed
- | borrow might be used here, when `o1` is dropped and runs the destructor for type `std::boxed::Box<dyn Obj<'_>>`
- |
- = note: values in a scope are dropped in the opposite order they are defined
-
-error[E0597]: `o2` does not live long enough
- --> $DIR/dropck_trait_cycle_checked.rs:113:13
- |
-LL | let (o1, o2, o3): (Box<dyn Obj>, Box<dyn Obj>, Box<dyn Obj>) = (O::new(), O::new(), O::new());
- | -------- cast requires that `o2` is borrowed for `'static`
-...
-LL | o2.set0(&o2);
- | ^^^ borrowed value does not live long enough
-...
-LL | }
- | - `o2` dropped here while still borrowed
-
-error[E0597]: `o3` does not live long enough
- --> $DIR/dropck_trait_cycle_checked.rs:114:13
- |
-LL | let (o1, o2, o3): (Box<dyn Obj>, Box<dyn Obj>, Box<dyn Obj>) = (O::new(), O::new(), O::new());
- | -------- cast requires that `o3` is borrowed for `'static`
-...
-LL | o2.set1(&o3);
- | ^^^ borrowed value does not live long enough
-...
-LL | }
- | - `o3` dropped here while still borrowed
-
-error[E0597]: `o1` does not live long enough
- --> $DIR/dropck_trait_cycle_checked.rs:115:13
- |
-LL | o3.set0(&o1);
- | ^^^ borrowed value does not live long enough
-LL | o3.set1(&o2);
-LL | }
- | -
- | |
- | `o1` dropped here while still borrowed
- | borrow might be used here, when `o1` is dropped and runs the destructor for type `std::boxed::Box<dyn Obj<'_>>`
-
-error[E0597]: `o2` does not live long enough
- --> $DIR/dropck_trait_cycle_checked.rs:116:13
- |
-LL | let (o1, o2, o3): (Box<dyn Obj>, Box<dyn Obj>, Box<dyn Obj>) = (O::new(), O::new(), O::new());
- | -------- cast requires that `o2` is borrowed for `'static`
-...
-LL | o3.set1(&o2);
- | ^^^ borrowed value does not live long enough
-LL | }
- | - `o2` dropped here while still borrowed
-
-error: aborting due to 6 previous errors
-
-For more information about this error, try `rustc --explain E0597`.
diff --git a/src/test/ui/generator/ref-escapes-but-not-over-yield.polonius.stderr b/src/test/ui/generator/ref-escapes-but-not-over-yield.polonius.stderr
deleted file mode 100644
index 530bf368f67..00000000000
--- a/src/test/ui/generator/ref-escapes-but-not-over-yield.polonius.stderr
+++ /dev/null
@@ -1,20 +0,0 @@
-error[E0597]: `b` does not live long enough
- --> $DIR/ref-escapes-but-not-over-yield.rs:11:13
- |
-LL | let mut b = move || {
- | _________________-
-LL | | yield();
-LL | | let b = 5;
-LL | | a = &b;
- | | ^^ borrowed value does not live long enough
-LL | |
-LL | | };
- | | -
- | | |
- | | `b` dropped here while still borrowed
- | |_____... and the borrow might be used here, when that temporary is dropped and runs the destructor for generator
- | a temporary with access to the borrow is created here ...
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0597`.
diff --git a/src/test/ui/nll/get_default.polonius.stderr b/src/test/ui/nll/get_default.polonius.stderr
index 2df6d5d61fc..476d86cfba9 100644
--- a/src/test/ui/nll/get_default.polonius.stderr
+++ b/src/test/ui/nll/get_default.polonius.stderr
@@ -1,6 +1,9 @@
error[E0502]: cannot borrow `*map` as mutable because it is also borrowed as immutable
--> $DIR/get_default.rs:32:17
|
+LL | fn err(map: &mut Map) -> &String {
+ | - let's call the lifetime of this reference `'1`
+LL | loop {
LL | match map.get() {
| --- immutable borrow occurs here
LL | Some(v) => {
@@ -8,7 +11,7 @@ LL | map.set(String::new()); // Both AST and MIR error here
| ^^^ mutable borrow occurs here
LL |
LL | return v;
- | - immutable borrow later used here
+ | - returning this value requires that `*map` is borrowed for `'1`
error: aborting due to previous error
diff --git a/src/test/ui/nll/loan_ends_mid_block_pair.polonius.stderr b/src/test/ui/nll/loan_ends_mid_block_pair.polonius.stderr
deleted file mode 100644
index eb8442b31d7..00000000000
--- a/src/test/ui/nll/loan_ends_mid_block_pair.polonius.stderr
+++ /dev/null
@@ -1,15 +0,0 @@
-error[E0506]: cannot assign to `data.0` because it is borrowed
- --> $DIR/loan_ends_mid_block_pair.rs:12:5
- |
-LL | let c = &mut data.0;
- | ----------- borrow of `data.0` occurs here
-LL | capitalize(c);
-LL | data.0 = 'e';
- | ^^^^^^^^^^^^ assignment to borrowed `data.0` occurs here
-...
-LL | capitalize(c);
- | - borrow later used here
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0506`.
diff --git a/src/test/ui/nll/polonius/polonius-smoke-test.stderr b/src/test/ui/nll/polonius/polonius-smoke-test.stderr
index dbc5b7a019a..1faf8e2212a 100644
--- a/src/test/ui/nll/polonius/polonius-smoke-test.stderr
+++ b/src/test/ui/nll/polonius/polonius-smoke-test.stderr
@@ -17,12 +17,14 @@ LL | let w = y;
error[E0505]: cannot move out of `x` because it is borrowed
--> $DIR/polonius-smoke-test.rs:19:13
|
+LL | pub fn use_while_mut_fr(x: &mut i32) -> &mut i32 {
+ | - let's call the lifetime of this reference `'1`
LL | let y = &mut *x;
| ------- borrow of `*x` occurs here
LL | let z = x;
| ^ move out of `x` occurs here
LL | y
- | - borrow later used here
+ | - returning this value requires that `*x` is borrowed for `'1`
error[E0505]: cannot move out of `s` because it is borrowed
--> $DIR/polonius-smoke-test.rs:43:5
diff --git a/src/test/ui/nll/return-ref-mut-issue-46557.polonius.stderr b/src/test/ui/nll/return-ref-mut-issue-46557.polonius.stderr
deleted file mode 100644
index 8e3cf59cffb..00000000000
--- a/src/test/ui/nll/return-ref-mut-issue-46557.polonius.stderr
+++ /dev/null
@@ -1,15 +0,0 @@
-error[E0716]: temporary value dropped while borrowed
- --> $DIR/return-ref-mut-issue-46557.rs:4:21
- |
-LL | let ref mut x = 1234543;
- | ^^^^^^^ creates a temporary which is freed while still in use
-LL | x
- | - borrow later used here
-LL | }
- | - temporary value is freed at the end of this statement
- |
- = note: consider using a `let` binding to create a longer lived value
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0716`.
diff --git a/src/test/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1.polonius.stderr b/src/test/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1.polonius.stderr
deleted file mode 100644
index 4b906f75149..00000000000
--- a/src/test/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1.polonius.stderr
+++ /dev/null
@@ -1,60 +0,0 @@
-error[E0597]: `factorial` does not live long enough
- --> $DIR/unboxed-closures-failed-recursive-fn-1.rs:15:17
- |
-LL | let f = |x: u32| -> u32 {
- | --------------- value captured here
-LL | let g = factorial.as_ref().unwrap();
- | ^^^^^^^^^ borrowed value does not live long enough
-...
-LL | }
- | -
- | |
- | `factorial` dropped here while still borrowed
- | borrow might be used here, when `factorial` is dropped and runs the destructor for type `std::option::Option<std::boxed::Box<dyn std::ops::Fn(u32) -> u32>>`
-
-error[E0506]: cannot assign to `factorial` because it is borrowed
- --> $DIR/unboxed-closures-failed-recursive-fn-1.rs:20:5
- |
-LL | let f = |x: u32| -> u32 {
- | --------------- borrow of `factorial` occurs here
-LL | let g = factorial.as_ref().unwrap();
- | --------- borrow occurs due to use in closure
-...
-LL | factorial = Some(Box::new(f));
- | ^^^^^^^^^
- | |
- | assignment to borrowed `factorial` occurs here
- | borrow later used here
-
-error[E0597]: `factorial` does not live long enough
- --> $DIR/unboxed-closures-failed-recursive-fn-1.rs:28:17
- |
-LL | let f = |x: u32| -> u32 {
- | --------------- value captured here
-LL | let g = factorial.as_ref().unwrap();
- | ^^^^^^^^^ borrowed value does not live long enough
-...
-LL | }
- | -
- | |
- | `factorial` dropped here while still borrowed
- | borrow might be used here, when `factorial` is dropped and runs the destructor for type `std::option::Option<std::boxed::Box<dyn std::ops::Fn(u32) -> u32>>`
-
-error[E0506]: cannot assign to `factorial` because it is borrowed
- --> $DIR/unboxed-closures-failed-recursive-fn-1.rs:33:5
- |
-LL | let f = |x: u32| -> u32 {
- | --------------- borrow of `factorial` occurs here
-LL | let g = factorial.as_ref().unwrap();
- | --------- borrow occurs due to use in closure
-...
-LL | factorial = Some(Box::new(f));
- | ^^^^^^^^^
- | |
- | assignment to borrowed `factorial` occurs here
- | borrow later used here
-
-error: aborting due to 4 previous errors
-
-Some errors have detailed explanations: E0506, E0597.
-For more information about an error, try `rustc --explain E0506`.
From 2180c243214ebce29c45c37020e929924a8520d8 Mon Sep 17 00:00:00 2001
From: Matthew Jasper <mjjasper1@gmail.com>
Date: Tue, 24 Sep 2019 21:55:49 +0100
Subject: [PATCH 2/2] Make lifetimes in constants live at the point of use
---
.../borrow_check/nll/type_check/mod.rs | 64 ++++++++++++-------
.../ui/hrtb/due-to-where-clause.nll.stderr | 8 +++
src/test/ui/hrtb/due-to-where-clause.rs | 3 -
src/test/ui/hrtb/due-to-where-clause.stderr | 2 +-
src/test/ui/nll/promoted-liveness.rs | 8 +++
5 files changed, 58 insertions(+), 27 deletions(-)
create mode 100644 src/test/ui/hrtb/due-to-where-clause.nll.stderr
create mode 100644 src/test/ui/nll/promoted-liveness.rs
diff --git a/src/librustc_mir/borrow_check/nll/type_check/mod.rs b/src/librustc_mir/borrow_check/nll/type_check/mod.rs
index b24ba596d7e..adc3381a1e7 100644
--- a/src/librustc_mir/borrow_check/nll/type_check/mod.rs
+++ b/src/librustc_mir/borrow_check/nll/type_check/mod.rs
@@ -276,7 +276,17 @@ impl<'a, 'b, 'tcx> Visitor<'tcx> for TypeVerifier<'a, 'b, 'tcx> {
fn visit_constant(&mut self, constant: &Constant<'tcx>, location: Location) {
self.super_constant(constant, location);
- self.sanitize_type(constant, constant.literal.ty);
+ let ty = self.sanitize_type(constant, constant.literal.ty);
+
+ self.cx.infcx.tcx.for_each_free_region(&ty, |live_region| {
+ let live_region_vid =
+ self.cx.borrowck_context.universal_regions.to_region_vid(live_region);
+ self.cx
+ .borrowck_context
+ .constraints
+ .liveness_constraints
+ .add_element(live_region_vid, location);
+ });
if let Some(annotation_index) = constant.user_ty {
if let Err(terr) = self.cx.relate_type_and_user_type(
@@ -528,25 +538,37 @@ impl<'a, 'b, 'tcx> TypeVerifier<'a, 'b, 'tcx> {
let parent_body = mem::replace(&mut self.body, promoted_body);
+ // Use new sets of constraints and closure bounds so that we can
+ // modify their locations.
let all_facts = &mut None;
let mut constraints = Default::default();
let mut closure_bounds = Default::default();
+ let mut liveness_constraints = LivenessValues::new(
+ Rc::new(RegionValueElements::new(promoted_body)),
+ );
// Don't try to add borrow_region facts for the promoted MIR
- mem::swap(self.cx.borrowck_context.all_facts, all_facts);
- // Use a new sets of constraints and closure bounds so that we can
- // modify their locations.
- mem::swap(
- &mut self.cx.borrowck_context.constraints.outlives_constraints,
- &mut constraints
- );
- mem::swap(
- &mut self.cx.borrowck_context.constraints.closure_bounds_mapping,
- &mut closure_bounds
- );
+ let mut swap_constraints = |this: &mut Self| {
+ mem::swap(this.cx.borrowck_context.all_facts, all_facts);
+ mem::swap(
+ &mut this.cx.borrowck_context.constraints.outlives_constraints,
+ &mut constraints
+ );
+ mem::swap(
+ &mut this.cx.borrowck_context.constraints.closure_bounds_mapping,
+ &mut closure_bounds
+ );
+ mem::swap(
+ &mut this.cx.borrowck_context.constraints.liveness_constraints,
+ &mut liveness_constraints
+ );
+ };
+
+ swap_constraints(self);
self.visit_body(promoted_body);
+
if !self.errors_reported {
// if verifier failed, don't do further checks to avoid ICEs
self.cx.typeck_mir(promoted_body);
@@ -554,23 +576,15 @@ impl<'a, 'b, 'tcx> TypeVerifier<'a, 'b, 'tcx> {
self.body = parent_body;
// Merge the outlives constraints back in, at the given location.
- mem::swap(self.cx.borrowck_context.all_facts, all_facts);
- mem::swap(
- &mut self.cx.borrowck_context.constraints.outlives_constraints,
- &mut constraints
- );
- mem::swap(
- &mut self.cx.borrowck_context.constraints.closure_bounds_mapping,
- &mut closure_bounds
- );
+ swap_constraints(self);
let locations = location.to_locations();
for constraint in constraints.outlives().iter() {
let mut constraint = *constraint;
constraint.locations = locations;
if let ConstraintCategory::Return
- | ConstraintCategory::UseAsConst
- | ConstraintCategory::UseAsStatic = constraint.category
+ | ConstraintCategory::UseAsConst
+ | ConstraintCategory::UseAsStatic = constraint.category
{
// "Returning" from a promoted is an assigment to a
// temporary from the user's point of view.
@@ -578,6 +592,10 @@ impl<'a, 'b, 'tcx> TypeVerifier<'a, 'b, 'tcx> {
}
self.cx.borrowck_context.constraints.outlives_constraints.push(constraint)
}
+ for live_region in liveness_constraints.rows() {
+ self.cx.borrowck_context.constraints.liveness_constraints
+ .add_element(live_region, location);
+ }
if !closure_bounds.is_empty() {
let combined_bounds_mapping = closure_bounds
diff --git a/src/test/ui/hrtb/due-to-where-clause.nll.stderr b/src/test/ui/hrtb/due-to-where-clause.nll.stderr
new file mode 100644
index 00000000000..e476047a7a6
--- /dev/null
+++ b/src/test/ui/hrtb/due-to-where-clause.nll.stderr
@@ -0,0 +1,8 @@
+error: higher-ranked subtype error
+ --> $DIR/due-to-where-clause.rs:2:5
+ |
+LL | test::<FooS>(&mut 42);
+ | ^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/hrtb/due-to-where-clause.rs b/src/test/ui/hrtb/due-to-where-clause.rs
index 04e2ddd4a60..1afd15613b5 100644
--- a/src/test/ui/hrtb/due-to-where-clause.rs
+++ b/src/test/ui/hrtb/due-to-where-clause.rs
@@ -1,6 +1,3 @@
-// ignore-compare-mode-nll
-// ^ This code works in nll mode.
-
fn main() {
test::<FooS>(&mut 42); //~ ERROR implementation of `Foo` is not general enough
}
diff --git a/src/test/ui/hrtb/due-to-where-clause.stderr b/src/test/ui/hrtb/due-to-where-clause.stderr
index 9fef1e33543..e4096ec059a 100644
--- a/src/test/ui/hrtb/due-to-where-clause.stderr
+++ b/src/test/ui/hrtb/due-to-where-clause.stderr
@@ -1,5 +1,5 @@
error: implementation of `Foo` is not general enough
- --> $DIR/due-to-where-clause.rs:5:5
+ --> $DIR/due-to-where-clause.rs:2:5
|
LL | test::<FooS>(&mut 42);
| ^^^^^^^^^^^^ implementation of `Foo` is not general enough
diff --git a/src/test/ui/nll/promoted-liveness.rs b/src/test/ui/nll/promoted-liveness.rs
new file mode 100644
index 00000000000..e5a8e1e5c2f
--- /dev/null
+++ b/src/test/ui/nll/promoted-liveness.rs
@@ -0,0 +1,8 @@
+// Test that promoted that have larger mir bodies than their containing function
+// don't cause an ICE.
+
+// check-pass
+
+fn main() {
+ &["0", "1", "2", "3", "4", "5", "6", "7"];
+}