From 98c9a3e1e9c4f0862864690b9c12e225a19cbe8b Mon Sep 17 00:00:00 2001 From: "Felix S. Klock II" Date: Tue, 30 Oct 2018 00:16:28 +0100 Subject: [PATCH 1/3] borrowck=migrate mode needs to check parent(s) when its given a closure. --- src/librustc_mir/borrow_check/mod.rs | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/src/librustc_mir/borrow_check/mod.rs b/src/librustc_mir/borrow_check/mod.rs index 6ef8b15545872..920040d1451bb 100644 --- a/src/librustc_mir/borrow_check/mod.rs +++ b/src/librustc_mir/borrow_check/mod.rs @@ -346,7 +346,33 @@ fn do_mir_borrowck<'a, 'gcx, 'tcx>( mbcx.errors_buffer.sort_by_key(|diag| diag.span.primary_span()); if tcx.migrate_borrowck() { - match tcx.borrowck(def_id).signalled_any_error { + // When borrowck=migrate, check if AST-borrowck would + // error on the given code. + + // rust-lang/rust#55492: loop over parents to ensure that + // errors that AST-borrowck only detects in some parent of + // a closure still allows NLL to signal an error. + let mut curr_def_id = def_id; + let signalled_any_error = loop { + match tcx.borrowck(curr_def_id).signalled_any_error { + SignalledError::NoErrorsSeen => { + // keep traversing (and borrow-checking) parents + } + SignalledError::SawSomeError => { + // stop search here + break SignalledError::SawSomeError; + } + } + + if tcx.is_closure(curr_def_id) { + curr_def_id = tcx.parent_def_id(curr_def_id) + .expect("a closure must have a parent_def_id"); + } else { + break SignalledError::NoErrorsSeen; + } + }; + + match signalled_any_error { SignalledError::NoErrorsSeen => { // if AST-borrowck signalled no errors, then // downgrade all the buffered MIR-borrowck errors From d5798c9554670728412abbc688ab6123bf7895d4 Mon Sep 17 00:00:00 2001 From: "Felix S. Klock II" Date: Tue, 30 Oct 2018 00:25:09 +0100 Subject: [PATCH 2/3] Regression test for issue 55492. --- ...-borrowck-migrate-scans-parents.ast.stderr | 55 +++++++++++++++++ ...rowck-migrate-scans-parents.migrate.stderr | 54 ++++++++++++++++ ...-borrowck-migrate-scans-parents.nll.stderr | 54 ++++++++++++++++ ...ue-55492-borrowck-migrate-scans-parents.rs | 61 +++++++++++++++++++ 4 files changed, 224 insertions(+) create mode 100644 src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.ast.stderr create mode 100644 src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.migrate.stderr create mode 100644 src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.nll.stderr create mode 100644 src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.rs diff --git a/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.ast.stderr b/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.ast.stderr new file mode 100644 index 0000000000000..3180823f64327 --- /dev/null +++ b/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.ast.stderr @@ -0,0 +1,55 @@ +error[E0595]: closure cannot assign to immutable argument `x` + --> $DIR/issue-55492-borrowck-migrate-scans-parents.rs:21:22 + | +LL | let mut c1 = |y: &'static mut isize| x = y; + | ^^^^^^^^^^^^^^^^^^^^^^^ cannot borrow mutably +help: consider removing the `&mut`, as it is an immutable binding to a mutable reference + | +LL | x + | + +error[E0595]: closure cannot assign to immutable argument `x` + --> $DIR/issue-55492-borrowck-migrate-scans-parents.rs:29:22 + | +LL | let mut c1 = |z: &'static mut isize| { + | ^^^^^^^^^^^^^^^^^^^^^^^ cannot borrow mutably +help: consider removing the `&mut`, as it is an immutable binding to a mutable reference + | +LL | x + | + +error[E0595]: closure cannot assign to immutable argument `x` + --> $DIR/issue-55492-borrowck-migrate-scans-parents.rs:40:9 + | +LL | pub fn capture_assign_whole(x: (i32,)) { + | - help: make this binding mutable: `mut x` +LL | || { x = (1,); }; + | ^^ cannot borrow mutably + +error[E0595]: closure cannot assign to immutable argument `x` + --> $DIR/issue-55492-borrowck-migrate-scans-parents.rs:43:9 + | +LL | pub fn capture_assign_part(x: (i32,)) { + | - help: make this binding mutable: `mut x` +LL | || { x.0 = 1; }; + | ^^ cannot borrow mutably + +error[E0595]: closure cannot assign to immutable argument `x` + --> $DIR/issue-55492-borrowck-migrate-scans-parents.rs:46:9 + | +LL | pub fn capture_reborrow_whole(x: (i32,)) { + | - help: make this binding mutable: `mut x` +LL | || { &mut x; }; + | ^^ cannot borrow mutably + +error[E0595]: closure cannot assign to immutable argument `x` + --> $DIR/issue-55492-borrowck-migrate-scans-parents.rs:49:9 + | +LL | pub fn capture_reborrow_part(x: (i32,)) { + | - help: make this binding mutable: `mut x` +LL | || { &mut x.0; }; + | ^^ cannot borrow mutably + +error: aborting due to 6 previous errors + +For more information about this error, try `rustc --explain E0595`. diff --git a/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.migrate.stderr b/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.migrate.stderr new file mode 100644 index 0000000000000..0ccddf0a67d6f --- /dev/null +++ b/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.migrate.stderr @@ -0,0 +1,54 @@ +error[E0594]: cannot assign to `x`, as it is not declared as mutable + --> $DIR/issue-55492-borrowck-migrate-scans-parents.rs:21:46 + | +LL | pub fn e(x: &'static mut isize) { + | - help: consider changing this to be mutable: `mut x` +LL | static mut Y: isize = 3; +LL | let mut c1 = |y: &'static mut isize| x = y; + | ^^^^^ cannot assign + +error[E0594]: cannot assign to `x`, as it is not declared as mutable + --> $DIR/issue-55492-borrowck-migrate-scans-parents.rs:30:50 + | +LL | pub fn ee(x: &'static mut isize) { + | - help: consider changing this to be mutable: `mut x` +... +LL | let mut c2 = |y: &'static mut isize| x = y; + | ^^^^^ cannot assign + +error[E0594]: cannot assign to `x`, as it is not declared as mutable + --> $DIR/issue-55492-borrowck-migrate-scans-parents.rs:40:14 + | +LL | pub fn capture_assign_whole(x: (i32,)) { + | - help: consider changing this to be mutable: `mut x` +LL | || { x = (1,); }; + | ^^^^^^^^ cannot assign + +error[E0594]: cannot assign to `x.0`, as `x` is not declared as mutable + --> $DIR/issue-55492-borrowck-migrate-scans-parents.rs:43:14 + | +LL | pub fn capture_assign_part(x: (i32,)) { + | - help: consider changing this to be mutable: `mut x` +LL | || { x.0 = 1; }; + | ^^^^^^^ cannot assign + +error[E0596]: cannot borrow `x` as mutable, as it is not declared as mutable + --> $DIR/issue-55492-borrowck-migrate-scans-parents.rs:46:14 + | +LL | pub fn capture_reborrow_whole(x: (i32,)) { + | - help: consider changing this to be mutable: `mut x` +LL | || { &mut x; }; + | ^^^^^^ cannot borrow as mutable + +error[E0596]: cannot borrow `x.0` as mutable, as `x` is not declared as mutable + --> $DIR/issue-55492-borrowck-migrate-scans-parents.rs:49:14 + | +LL | pub fn capture_reborrow_part(x: (i32,)) { + | - help: consider changing this to be mutable: `mut x` +LL | || { &mut x.0; }; + | ^^^^^^^^ cannot borrow as mutable + +error: aborting due to 6 previous errors + +Some errors occurred: E0594, E0596. +For more information about an error, try `rustc --explain E0594`. diff --git a/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.nll.stderr b/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.nll.stderr new file mode 100644 index 0000000000000..0ccddf0a67d6f --- /dev/null +++ b/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.nll.stderr @@ -0,0 +1,54 @@ +error[E0594]: cannot assign to `x`, as it is not declared as mutable + --> $DIR/issue-55492-borrowck-migrate-scans-parents.rs:21:46 + | +LL | pub fn e(x: &'static mut isize) { + | - help: consider changing this to be mutable: `mut x` +LL | static mut Y: isize = 3; +LL | let mut c1 = |y: &'static mut isize| x = y; + | ^^^^^ cannot assign + +error[E0594]: cannot assign to `x`, as it is not declared as mutable + --> $DIR/issue-55492-borrowck-migrate-scans-parents.rs:30:50 + | +LL | pub fn ee(x: &'static mut isize) { + | - help: consider changing this to be mutable: `mut x` +... +LL | let mut c2 = |y: &'static mut isize| x = y; + | ^^^^^ cannot assign + +error[E0594]: cannot assign to `x`, as it is not declared as mutable + --> $DIR/issue-55492-borrowck-migrate-scans-parents.rs:40:14 + | +LL | pub fn capture_assign_whole(x: (i32,)) { + | - help: consider changing this to be mutable: `mut x` +LL | || { x = (1,); }; + | ^^^^^^^^ cannot assign + +error[E0594]: cannot assign to `x.0`, as `x` is not declared as mutable + --> $DIR/issue-55492-borrowck-migrate-scans-parents.rs:43:14 + | +LL | pub fn capture_assign_part(x: (i32,)) { + | - help: consider changing this to be mutable: `mut x` +LL | || { x.0 = 1; }; + | ^^^^^^^ cannot assign + +error[E0596]: cannot borrow `x` as mutable, as it is not declared as mutable + --> $DIR/issue-55492-borrowck-migrate-scans-parents.rs:46:14 + | +LL | pub fn capture_reborrow_whole(x: (i32,)) { + | - help: consider changing this to be mutable: `mut x` +LL | || { &mut x; }; + | ^^^^^^ cannot borrow as mutable + +error[E0596]: cannot borrow `x.0` as mutable, as `x` is not declared as mutable + --> $DIR/issue-55492-borrowck-migrate-scans-parents.rs:49:14 + | +LL | pub fn capture_reborrow_part(x: (i32,)) { + | - help: consider changing this to be mutable: `mut x` +LL | || { &mut x.0; }; + | ^^^^^^^^ cannot borrow as mutable + +error: aborting due to 6 previous errors + +Some errors occurred: E0594, E0596. +For more information about an error, try `rustc --explain E0594`. diff --git a/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.rs b/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.rs new file mode 100644 index 0000000000000..25ad66a5d9b4a --- /dev/null +++ b/src/test/ui/borrowck/issue-55492-borrowck-migrate-scans-parents.rs @@ -0,0 +1,61 @@ +// rust-lang/rust#55492: errors detected during MIR-borrowck's +// analysis of a closure body may only be caught when AST-borrowck +// looks at some parent. + +// revisions: ast migrate nll + +// Since we are testing nll (and migration) explicitly as a separate +// revisions, don't worry about the --compare-mode=nll on this test. + +// ignore-compare-mode-nll + +//[ast]compile-flags: -Z borrowck=ast +//[migrate]compile-flags: -Z borrowck=migrate -Z two-phase-borrows +//[nll]compile-flags: -Z borrowck=mir -Z two-phase-borrows + + +// transcribed from borrowck-closures-unique.rs +mod borrowck_closures_unique { + pub fn e(x: &'static mut isize) { + static mut Y: isize = 3; + let mut c1 = |y: &'static mut isize| x = y; + unsafe { c1(&mut Y); } + } +} + +mod borrowck_closures_unique_grandparent { + pub fn ee(x: &'static mut isize) { + static mut Z: isize = 3; + let mut c1 = |z: &'static mut isize| { + let mut c2 = |y: &'static mut isize| x = y; + c2(z); + }; + unsafe { c1(&mut Z); } + } +} + +// adapted from mutability_errors.rs +mod mutability_errors { + pub fn capture_assign_whole(x: (i32,)) { + || { x = (1,); }; + } + pub fn capture_assign_part(x: (i32,)) { + || { x.0 = 1; }; + } + pub fn capture_reborrow_whole(x: (i32,)) { + || { &mut x; }; + } + pub fn capture_reborrow_part(x: (i32,)) { + || { &mut x.0; }; + } +} + +fn main() { + static mut X: isize = 2; + unsafe { borrowck_closures_unique::e(&mut X); } + + mutability_errors::capture_assign_whole((1000,)); + mutability_errors::capture_assign_part((2000,)); + mutability_errors::capture_reborrow_whole((3000,)); + mutability_errors::capture_reborrow_part((4000,)); +} From 87ce5ec6e955849189887e56dfafc45e1293f63f Mon Sep 17 00:00:00 2001 From: "Felix S. Klock II" Date: Tue, 30 Oct 2018 00:37:38 +0100 Subject: [PATCH 3/3] Update compare-mode=nll stderr files to reflect the fix to #55492. --- .../borrowck-closures-unique.nll.stderr | 8 ++---- .../borrowck-describe-lvalue.ast.nll.stderr | 7 ++--- .../ui/borrowck/mutability-errors.nll.stderr | 26 ++++--------------- ...boxed-closure-immutable-capture.nll.stderr | 26 ++++--------------- ...nfer-fnmut-calling-fnmut-no-mut.nll.stderr | 8 ++---- .../unboxed-closures-mutate-upvar.nll.stderr | 8 ++---- 6 files changed, 18 insertions(+), 65 deletions(-) diff --git a/src/test/ui/borrowck/borrowck-closures-unique.nll.stderr b/src/test/ui/borrowck/borrowck-closures-unique.nll.stderr index 771ef88a662b1..231ae53fe82bf 100644 --- a/src/test/ui/borrowck/borrowck-closures-unique.nll.stderr +++ b/src/test/ui/borrowck/borrowck-closures-unique.nll.stderr @@ -40,19 +40,15 @@ LL | let c2 = || set(x); //~ ERROR two closures require unique access to `x` LL | c1; | -- first borrow later used here -warning[E0594]: cannot assign to `x`, as it is not declared as mutable +error[E0594]: cannot assign to `x`, as it is not declared as mutable --> $DIR/borrowck-closures-unique.rs:57:38 | LL | fn e(x: &'static mut isize) { | - help: consider changing this to be mutable: `mut x` LL | let c1 = |y: &'static mut isize| x = y; //~ ERROR closure cannot assign to immutable argument | ^^^^^ cannot assign - | - = warning: This error has been downgraded to a warning for backwards compatibility with previous releases. - It represents potential unsoundness in your code. - This warning will become a hard error in the future. -error: aborting due to 3 previous errors +error: aborting due to 4 previous errors Some errors occurred: E0500, E0524, E0594. For more information about an error, try `rustc --explain E0500`. diff --git a/src/test/ui/borrowck/borrowck-describe-lvalue.ast.nll.stderr b/src/test/ui/borrowck/borrowck-describe-lvalue.ast.nll.stderr index 88ae73b6368e7..c3aba793f190e 100644 --- a/src/test/ui/borrowck/borrowck-describe-lvalue.ast.nll.stderr +++ b/src/test/ui/borrowck/borrowck-describe-lvalue.ast.nll.stderr @@ -20,7 +20,7 @@ LL | //[mir]~^ ERROR cannot borrow `x` as mutable more than o LL | *y = 1; | ------ first borrow later used here -warning: captured variable cannot escape `FnMut` closure body +error: captured variable cannot escape `FnMut` closure body --> $DIR/borrowck-describe-lvalue.rs:305:16 | LL | || { @@ -36,9 +36,6 @@ LL | | } | = note: `FnMut` closures only have access to their captured variables while they are executing... = note: ...therefore, they cannot allow references to captured variables to escape - = warning: This error has been downgraded to a warning for backwards compatibility with previous releases. - It represents potential unsoundness in your code. - This warning will become a hard error in the future. error[E0503]: cannot use `f.x` because it was mutably borrowed --> $DIR/borrowck-describe-lvalue.rs:53:9 @@ -382,7 +379,7 @@ LL | drop(x); //[ast]~ ERROR use of moved value: `x` | = note: move occurs because `x` has type `std::vec::Vec`, which does not implement the `Copy` trait -error: aborting due to 29 previous errors +error: aborting due to 30 previous errors Some errors occurred: E0382, E0499, E0502, E0503. For more information about an error, try `rustc --explain E0382`. diff --git a/src/test/ui/borrowck/mutability-errors.nll.stderr b/src/test/ui/borrowck/mutability-errors.nll.stderr index bb45fe2da8117..14c41bb81b2c6 100644 --- a/src/test/ui/borrowck/mutability-errors.nll.stderr +++ b/src/test/ui/borrowck/mutability-errors.nll.stderr @@ -277,7 +277,7 @@ LL | &mut x; //~ ERROR LL | &mut x.0; //~ ERROR | ^^^^^^^^ cannot borrow as mutable -warning[E0594]: cannot assign to `x`, as it is not declared as mutable +error[E0594]: cannot assign to `x`, as it is not declared as mutable --> $DIR/mutability-errors.rs:70:9 | LL | fn imm_capture(x: (i32,)) { @@ -285,12 +285,8 @@ LL | fn imm_capture(x: (i32,)) { LL | || { //~ ERROR LL | x = (1,); | ^^^^^^^^ cannot assign - | - = warning: This error has been downgraded to a warning for backwards compatibility with previous releases. - It represents potential unsoundness in your code. - This warning will become a hard error in the future. -warning[E0594]: cannot assign to `x.0`, as `x` is not declared as mutable +error[E0594]: cannot assign to `x.0`, as `x` is not declared as mutable --> $DIR/mutability-errors.rs:71:9 | LL | fn imm_capture(x: (i32,)) { @@ -298,12 +294,8 @@ LL | fn imm_capture(x: (i32,)) { ... LL | x.0 = 1; | ^^^^^^^ cannot assign - | - = warning: This error has been downgraded to a warning for backwards compatibility with previous releases. - It represents potential unsoundness in your code. - This warning will become a hard error in the future. -warning[E0596]: cannot borrow `x` as mutable, as it is not declared as mutable +error[E0596]: cannot borrow `x` as mutable, as it is not declared as mutable --> $DIR/mutability-errors.rs:72:9 | LL | fn imm_capture(x: (i32,)) { @@ -311,12 +303,8 @@ LL | fn imm_capture(x: (i32,)) { ... LL | &mut x; | ^^^^^^ cannot borrow as mutable - | - = warning: This error has been downgraded to a warning for backwards compatibility with previous releases. - It represents potential unsoundness in your code. - This warning will become a hard error in the future. -warning[E0596]: cannot borrow `x.0` as mutable, as `x` is not declared as mutable +error[E0596]: cannot borrow `x.0` as mutable, as `x` is not declared as mutable --> $DIR/mutability-errors.rs:73:9 | LL | fn imm_capture(x: (i32,)) { @@ -324,10 +312,6 @@ LL | fn imm_capture(x: (i32,)) { ... LL | &mut x.0; | ^^^^^^^^ cannot borrow as mutable - | - = warning: This error has been downgraded to a warning for backwards compatibility with previous releases. - It represents potential unsoundness in your code. - This warning will become a hard error in the future. error[E0594]: cannot assign to `x`, as it is not declared as mutable --> $DIR/mutability-errors.rs:76:9 @@ -389,7 +373,7 @@ error[E0596]: cannot borrow `X.0` as mutable, as `X` is an immutable static item LL | &mut X.0; //~ ERROR | ^^^^^^^^ cannot borrow as mutable -error: aborting due to 34 previous errors +error: aborting due to 38 previous errors Some errors occurred: E0594, E0596. For more information about an error, try `rustc --explain E0594`. diff --git a/src/test/ui/unboxed-closures/unboxed-closure-immutable-capture.nll.stderr b/src/test/ui/unboxed-closures/unboxed-closure-immutable-capture.nll.stderr index ee91ea3b66f30..084d7ff3bcd61 100644 --- a/src/test/ui/unboxed-closures/unboxed-closure-immutable-capture.nll.stderr +++ b/src/test/ui/unboxed-closures/unboxed-closure-immutable-capture.nll.stderr @@ -33,7 +33,7 @@ LL | let x = 0; LL | move || set(&mut x); //~ ERROR cannot borrow | ^^^^^^ cannot borrow as mutable -warning[E0594]: cannot assign to `x`, as it is not declared as mutable +error[E0594]: cannot assign to `x`, as it is not declared as mutable --> $DIR/unboxed-closure-immutable-capture.rs:23:8 | LL | let x = 0; @@ -41,12 +41,8 @@ LL | let x = 0; ... LL | || x = 1; //~ ERROR cannot assign | ^^^^^ cannot assign - | - = warning: This error has been downgraded to a warning for backwards compatibility with previous releases. - It represents potential unsoundness in your code. - This warning will become a hard error in the future. -warning[E0596]: cannot borrow `x` as mutable, as it is not declared as mutable +error[E0596]: cannot borrow `x` as mutable, as it is not declared as mutable --> $DIR/unboxed-closure-immutable-capture.rs:25:12 | LL | let x = 0; @@ -54,12 +50,8 @@ LL | let x = 0; ... LL | || set(&mut x); //~ ERROR cannot assign | ^^^^^^ cannot borrow as mutable - | - = warning: This error has been downgraded to a warning for backwards compatibility with previous releases. - It represents potential unsoundness in your code. - This warning will become a hard error in the future. -warning[E0594]: cannot assign to `x`, as it is not declared as mutable +error[E0594]: cannot assign to `x`, as it is not declared as mutable --> $DIR/unboxed-closure-immutable-capture.rs:26:8 | LL | let x = 0; @@ -67,12 +59,8 @@ LL | let x = 0; ... LL | || x = 1; //~ ERROR cannot assign | ^^^^^ cannot assign - | - = warning: This error has been downgraded to a warning for backwards compatibility with previous releases. - It represents potential unsoundness in your code. - This warning will become a hard error in the future. -warning[E0596]: cannot borrow `x` as mutable, as it is not declared as mutable +error[E0596]: cannot borrow `x` as mutable, as it is not declared as mutable --> $DIR/unboxed-closure-immutable-capture.rs:28:12 | LL | let x = 0; @@ -80,12 +68,8 @@ LL | let x = 0; ... LL | || set(&mut x); //~ ERROR cannot assign | ^^^^^^ cannot borrow as mutable - | - = warning: This error has been downgraded to a warning for backwards compatibility with previous releases. - It represents potential unsoundness in your code. - This warning will become a hard error in the future. -error: aborting due to 4 previous errors +error: aborting due to 8 previous errors Some errors occurred: E0594, E0596. For more information about an error, try `rustc --explain E0594`. diff --git a/src/test/ui/unboxed-closures/unboxed-closures-infer-fnmut-calling-fnmut-no-mut.nll.stderr b/src/test/ui/unboxed-closures/unboxed-closures-infer-fnmut-calling-fnmut-no-mut.nll.stderr index fa0aba96e18be..718c3a19938c4 100644 --- a/src/test/ui/unboxed-closures/unboxed-closures-infer-fnmut-calling-fnmut-no-mut.nll.stderr +++ b/src/test/ui/unboxed-closures/unboxed-closures-infer-fnmut-calling-fnmut-no-mut.nll.stderr @@ -1,4 +1,4 @@ -warning[E0596]: cannot borrow `tick1` as mutable, as it is not declared as mutable +error[E0596]: cannot borrow `tick1` as mutable, as it is not declared as mutable --> $DIR/unboxed-closures-infer-fnmut-calling-fnmut-no-mut.rs:27:9 | LL | let tick1 = || { @@ -6,10 +6,6 @@ LL | let tick1 = || { ... LL | tick1(); | ^^^^^ cannot borrow as mutable - | - = warning: This error has been downgraded to a warning for backwards compatibility with previous releases. - It represents potential unsoundness in your code. - This warning will become a hard error in the future. error[E0596]: cannot borrow `tick2` as mutable, as it is not declared as mutable --> $DIR/unboxed-closures-infer-fnmut-calling-fnmut-no-mut.rs:30:5 @@ -20,6 +16,6 @@ LL | let tick2 = || { //~ ERROR closure cannot assign to immutable local var LL | tick2(); //~ ERROR cannot borrow | ^^^^^ cannot borrow as mutable -error: aborting due to previous error +error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0596`. diff --git a/src/test/ui/unboxed-closures/unboxed-closures-mutate-upvar.nll.stderr b/src/test/ui/unboxed-closures/unboxed-closures-mutate-upvar.nll.stderr index 9858b8db2112d..f765f207303d2 100644 --- a/src/test/ui/unboxed-closures/unboxed-closures-mutate-upvar.nll.stderr +++ b/src/test/ui/unboxed-closures/unboxed-closures-mutate-upvar.nll.stderr @@ -1,4 +1,4 @@ -warning[E0594]: cannot assign to `n`, as it is not declared as mutable +error[E0594]: cannot assign to `n`, as it is not declared as mutable --> $DIR/unboxed-closures-mutate-upvar.rs:25:9 | LL | let n = 0; @@ -6,10 +6,6 @@ LL | let n = 0; LL | let mut f = to_fn_mut(|| { //~ ERROR closure cannot assign LL | n += 1; | ^^^^^^ cannot assign - | - = warning: This error has been downgraded to a warning for backwards compatibility with previous releases. - It represents potential unsoundness in your code. - This warning will become a hard error in the future. error[E0594]: cannot assign to `n`, as it is not declared as mutable --> $DIR/unboxed-closures-mutate-upvar.rs:42:9 @@ -44,6 +40,6 @@ LL | | n += 1; //~ ERROR cannot assign LL | | }); | |_____^ -error: aborting due to 3 previous errors +error: aborting due to 4 previous errors For more information about this error, try `rustc --explain E0594`.