First attempt at removing DropAndReplace

[zeegomo]

First attempt at removing the DropAndReplace terminator which complicates things a bit in some cases.
Based on zulip/drop-to-drop-if

Eventually, I re-introduced a flag in the Drop terminator to indicate whether this drop is from a drop and replace operation. This is used mainly for better diagnostic and to check some invariants.

Failing UI Tests

• Diagnostic underline whole assignment instead of just the left value

ex:

71	LL | *ap0 = ap1; - | ^^^^ assignment requires that `'2` must outlive `'1` + | ^^^^^^^^^^ assignment requires that `'2` must outlive `'1` 73 |

[ui] src/test/ui/borrowck/borrowck-field-sensitivity.rs
[ui] src/test/ui/borrowck/borrowck-issue-48962.rs
[ui] src/test/ui/borrowck/borrowck-loan-of-static-data-issue-27616.rs
[ui] src/test/ui/borrowck/borrowck-partial-reinit-1.rs
[ui] src/test/ui/borrowck/borrowck-partial-reinit-2.rs
[ui] src/test/ui/borrowck/borrowck-partial-reinit-4.rs
[ui] src/test/ui/borrowck/borrowck-vec-pattern-nesting.rs
[ui] src/test/ui/borrowck/index-mut-help.rs
[ui] src/test/ui/borrowck/issue-45199.rs
[ui] src/test/ui/c-variadic/variadic-ffi-4.rs
[ui] src/test/ui/closures/2229_closure_analysis/diagnostics/box.rs
[ui] src/test/ui/liveness/liveness-assign/liveness-assign-imm-local-with-drop.rs
[ui] src/test/ui/nll/issue-27868.rs
[ui] src/test/ui/object-lifetime/object-lifetime-default-from-box-error.rs
[ui] src/test/ui/regions/regions-infer-paramd-indirect.rs
[ui] src/test/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1.rs

• Replace kills loans on previous value

12	LL | println!("thread result: {:?}", res); 13 | --- borrow later used here 14 -	error[E0505]: cannot move out of `greeting` because it is borrowed - --> $DIR/issue-58776-borrowck-scans-children.rs:7:10 - | -	LL | let res = (|| (|| &greeting)())(); - | -- -------- borrow occurs due to use in closure - | | - | borrow of `greeting` occurs here -	... -	LL | drop(greeting); - | ^^^^^^^^ move out of `greeting` occurs here -	... -	LL | println!("thread result: {:?}", res); - | --- borrow later used here +	error: aborting due to previous error 28 -	error: aborting due to 2 previous errors - -	Some errors have detailed explanations: E0505, E0506. -	For more information about an error, try `rustc --explain E0505`. +	For more information about this error, try `rustc --explain E0506`. 33

destructured assignment from drop and replace now kills loans. I don't think it's too big of an issue as the assignment should already trigger the borrowck, but the compiler now reports fewer errors in some cases
[ui] src/test/ui/borrowck/issue-58776-borrowck-scans-children.rs

Also fixes #70919 but I didn't add any regression tests for it, might borrow them from #102078 in a separate PR once this lands

[rustbot]

r? @compiler-errors

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[compiler-errors]

r? @nikomatsakis since I think he wrote the MCP.

[bors]

☔ The latest upstream changes (presumably #103138) made this pull request unmergeable. Please resolve the merge conflicts.

[zeegomo]

Figured out what the problem with the future size was.
The desugaring of a = b; in drop(a); assign(a, b) at MIR creation might create dead MIR blocks on the unwind path, because the drop is a no-op (e.g. the variable is certainly dead at this stage) or can't unwind.
During drop elaboration, we run some dataflow analyses to track the initialization state of the variables to drop and here's the problem.
For some reason (would love some insight), we push all MIR blocks in the dataflow work queue and process them, even thought they might not be reachable from the start (just talking about forward analyses).
In this case, this cause processing of dead blocks which propagate incorrect values for liveness analysis.
My solution was to change the fixpoint alg to only consider blocks reachable from the start.
For backwards compatibility this can be tweaked with a flag, might be useful for other analyses as well.

[nikomatsakis]

Initial round of comments

[nikomatsakis]

I don't follow this logic

[zeegomo]

It's this case here

rust/compiler/rustc_mir_transform/src/elaborate_drops.rs

Line 477 in 270c94e

// drop and replace behind a pointer/array/whatever. The location

, will add a better comment

[rustbot]

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

This PR changes MIR

cc @oli-obk, @RalfJung, @JakobDegen, @davidtwco, @celinval, @vakaras

Some changes occurred to the CTFE / Miri engine

cc @rust-lang/miri

Some changes occurred in compiler/rustc_codegen_cranelift

cc @bjorn3

[zeegomo]

Some of the changes here like 114c696 could be moved to a separate independent PR.
Not sure of what's your preference on this, didn't want to split the discussion in too many places

some changes merged separately in #106451

[bors]

☔ The latest upstream changes (presumably #106472) made this pull request unmergeable. Please resolve the merge conflicts.

[zeegomo]

@oli-obk suggestion to use https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/struct.Span.html#method.mark_with_reason seems to be very promising.
I was able to remove is_replace entirely and retain all the checks in the borrowck.
There are now a few additional changes in ui tests but are still regarding the assignment span, which I believe should be ok.

[rust-log-analyzer]

The job x86_64-gnu-llvm-13 failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

............................................................i........................... 880/14144 ........................................................................i............... 968/14144 ........................................................................................ 1056/14144 ........................................................................................ 1144/14144 ..................................F..................F........F..F...................... 1232/14144 ..............F..........F...F...F...............................................F...... 1320/14144 ......F.................F..................F..................................i......... 1408/14144 .......................................................................................F 1496/14144 .....................................................................F.................. 1672/14144 ........................................................................................ 1760/14144 ........................................................................................ 1848/14144 .i...................i...........ii..................................................... 1936/14144 --- ---- [ui] checkout/tests/ui/borrowck/borrowck-field-sensitivity.rs stdout ---- diff of stderr: 134 LL | let mut x: A; 135 | ----- binding declared here but left uninitialized 136 LL | x.b = Box::new(1); - | ^^^ `x` partially assigned here but it isn't fully initialized + | ^^^^^^^^^^^^^^^^^ `x` partially assigned here but it isn't fully initialized 138 | 139 = help: partial initialization isn't supported, fully initialize the binding with a default value and mutate it, or use `std::mem::MaybeUninit` The actual stderr differed from the expected stderr. Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-field-sensitivity/borrowck-field-sensitivity.stderr Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-field-sensitivity/borrowck-field-sensitivity.stderr To update references, rerun the tests and pass the `--bless` flag To only update this specific test, also pass `--test-args borrowck/borrowck-field-sensitivity.rs` error: 1 errors occurred comparing output. status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/borrowck/borrowck-field-sensitivity.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-field-sensitivity" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-field-sensitivity/auxiliary" stdout: none --- stderr ------------------------------- error[E0382]: use of moved value: `x.b` | LL | drop(x.b); | --- value moved here | --- value moved here LL | drop(*x.b); //~ ERROR use of moved value: `x.b` | ^^^^ value used here after move | = note: move occurs because `x.b` has type `Box<isize>`, which does not implement the `Copy` trait error[E0382]: use of moved value: `x.b` --> /checkout/tests/ui/borrowck/borrowck-field-sensitivity.rs:14:10 | | LL | let y = A { a: 3, .. x }; | ---------------- value moved here LL | drop(*x.b); //~ ERROR use of moved value: `x.b` | ^^^^ value used here after move | = note: move occurs because `x.b` has type `Box<isize>`, which does not implement the `Copy` trait error[E0382]: borrow of moved value: `x.b` --> /checkout/tests/ui/borrowck/borrowck-field-sensitivity.rs:20:13 | LL | drop(x.b); LL | drop(x.b); | --- value moved here LL | let p = &x.b; //~ ERROR borrow of moved value: `x.b` | | = note: move occurs because `x.b` has type `Box<isize>`, which does not implement the `Copy` trait error[E0382]: borrow of moved value: `x.b` --> /checkout/tests/ui/borrowck/borrowck-field-sensitivity.rs:27:13 | | LL | let _y = A { a: 3, .. x }; | ---------------- value moved here LL | let p = &x.b; //~ ERROR borrow of moved value: `x.b` | | = note: move occurs because `x.b` has type `Box<isize>`, which does not implement the `Copy` trait error[E0505]: cannot move out of `x.b` because it is borrowed | | LL | let p = &x.b; | ---- borrow of `x.b` occurs here LL | drop(x.b); //~ ERROR cannot move out of `x.b` because it is borrowed | ^^^ move out of `x.b` occurs here LL | drop(**p); error[E0505]: cannot move out of `x.b` because it is borrowed | | LL | let p = &x.b; | ---- borrow of `x.b` occurs here LL | let _y = A { a: 3, .. x }; //~ ERROR cannot move out of `x.b` because it is borrowed | ^^^^^^^^^^^^^^^^ move out of `x.b` occurs here LL | drop(**p); error[E0499]: cannot borrow `x.a` as mutable more than once at a time | LL | let p = &mut x.a; | -------- first mutable borrow occurs here | -------- first mutable borrow occurs here LL | let q = &mut x.a; //~ ERROR cannot borrow `x.a` as mutable more than once at a time | ^^^^^^^^ second mutable borrow occurs here LL | drop(*p); error[E0382]: use of moved value: `x.b` --> /checkout/tests/ui/borrowck/borrowck-field-sensitivity.rs:56:10 | | LL | drop(x.b); | --- value moved here LL | drop(x.b); //~ ERROR use of moved value: `x.b` | ^^^ value used here after move | = note: move occurs because `x.b` has type `Box<isize>`, which does not implement the `Copy` trait error[E0382]: use of moved value: `x.b` --> /checkout/tests/ui/borrowck/borrowck-field-sensitivity.rs:62:10 | | LL | let _y = A { a: 3, .. x }; | ---------------- value moved here LL | drop(x.b); //~ ERROR use of moved value: `x.b` | ^^^ value used here after move | = note: move occurs because `x.b` has type `Box<isize>`, which does not implement the `Copy` trait error[E0382]: use of moved value: `x.b` --> /checkout/tests/ui/borrowck/borrowck-field-sensitivity.rs:68:14 | LL | drop(x.b); LL | drop(x.b); | --- value moved here LL | let _z = A { a: 3, .. x }; //~ ERROR use of moved value: `x.b` | ^^^^^^^^^^^^^^^^ value used here after move | = note: move occurs because `x.b` has type `Box<isize>`, which does not implement the `Copy` trait error[E0382]: use of moved value: `x.b` --> /checkout/tests/ui/borrowck/borrowck-field-sensitivity.rs:74:14 | | LL | let _y = A { a: 3, .. x }; | ---------------- value moved here LL | let _z = A { a: 4, .. x }; //~ ERROR use of moved value: `x.b` | ^^^^^^^^^^^^^^^^ value used here after move | = note: move occurs because `x.b` has type `Box<isize>`, which does not implement the `Copy` trait error[E0381]: partially assigned binding `x` isn't fully initialized | LL | let mut x: A; LL | let mut x: A; | ----- binding declared here but left uninitialized LL | x.a = 1; //~ ERROR E0381 | ^^^^^^^ `x` partially assigned here but it isn't fully initialized | = help: partial initialization isn't supported, fully initialize the binding with a default value and mutate it, or use `std::mem::MaybeUninit` error[E0381]: partially assigned binding `x` isn't fully initialized | LL | let mut x: A; LL | let mut x: A; | ----- binding declared here but left uninitialized LL | x.a = 1; //~ ERROR E0381 | ^^^^^^^ `x` partially assigned here but it isn't fully initialized | = help: partial initialization isn't supported, fully initialize the binding with a default value and mutate it, or use `std::mem::MaybeUninit` error[E0381]: partially assigned binding `x` isn't fully initialized | LL | let mut x: A; LL | let mut x: A; | ----- binding declared here but left uninitialized LL | x.b = Box::new(1); //~ ERROR E0381 | ^^^^^^^^^^^^^^^^^ `x` partially assigned here but it isn't fully initialized | = help: partial initialization isn't supported, fully initialize the binding with a default value and mutate it, or use `std::mem::MaybeUninit` error: aborting due to 14 previous errors Some errors have detailed explanations: E0381, E0382, E0499, E0505. For more information about an error, try `rustc --explain E0381`. --- To only update this specific test, also pass `--test-args borrowck/borrowck-issue-48962.rs` error: 1 errors occurred comparing output. status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/borrowck/borrowck-issue-48962.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-issue-48962" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-issue-48962/auxiliary" stdout: none --- stderr ------------------------------- error[E0382]: use of moved value: `src` | LL | let mut src = &mut node; LL | let mut src = &mut node; | ------- move occurs because `src` has type `&mut Node`, which does not implement the `Copy` trait LL | {src}; | --- value moved here LL | src.next = None; //~ ERROR use of moved value: `src` [E0382] | ^^^^^^^^^^^^^^^ value used here after move error[E0382]: use of moved value: `src` --> /checkout/tests/ui/borrowck/borrowck-issue-48962.rs:20:5 | | LL | let mut src = &mut (22, 44); | ------- move occurs because `src` has type `&mut (i32, i32)`, which does not implement the `Copy` trait LL | {src}; | --- value moved here LL | src.0 = 66; //~ ERROR use of moved value: `src` [E0382] | ^^^^^^^^^^ value used here after move error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0382`. ------------------------------------------ ------------------------------------------ ---- [ui] checkout/tests/ui/borrowck/borrowck-lend-flow-loop.rs stdout ---- diff of stderr: 8 | ^^^ immutable borrow occurs here 9 LL | } 10 LL | *x = Box::new(5); - | -- mutable borrow later used here + | ---------------- mutable borrow later used here Some tests failed in compiletest suite=ui mode=ui host=x86_64-unknown-linux-gnu target=x86_64-unknown-linux-gnu Some tests failed in compiletest suite=ui mode=ui host=x86_64-unknown-linux-gnu target=x86_64-unknown-linux-gnu 13 error[E0502]: cannot borrow `*v` as immutable because it is also borrowed as mutable The actual stderr differed from the expected stderr. Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-lend-flow-loop/borrowck-lend-flow-loop.stderr Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-lend-flow-loop/borrowck-lend-flow-loop.stderr To update references, rerun the tests and pass the `--bless` flag To only update this specific test, also pass `--test-args borrowck/borrowck-lend-flow-loop.rs` error: 1 errors occurred comparing output. status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/borrowck/borrowck-lend-flow-loop.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-lend-flow-loop" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-lend-flow-loop/auxiliary" stdout: none --- stderr ------------------------------- error[E0502]: cannot borrow `*v` as immutable because it is also borrowed as mutable | LL | let mut x = &mut v; LL | let mut x = &mut v; | ------ mutable borrow occurs here LL | for _ in 0..3 { LL | borrow(&*v); //~ ERROR cannot borrow | ^^^ immutable borrow occurs here LL | } LL | *x = Box::new(5); | ---------------- mutable borrow later used here error[E0502]: cannot borrow `*v` as immutable because it is also borrowed as mutable | | LL | **x += 1; | -------- mutable borrow later used here LL | borrow(&*v); //~ ERROR cannot borrow | ^^^ immutable borrow occurs here LL | if cond2 { LL | x = &mut v; // OK | ------ mutable borrow occurs here error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0502`. ------------------------------------------ ------------------------------------------ ---- [ui] checkout/tests/ui/borrowck/borrowck-loan-of-static-data-issue-27616.rs stdout ---- diff of stderr: 7 | type annotation requires that `*s` is borrowed for `'static` 9 LL | *s = String::new(); 9 LL | *s = String::new(); - | ^^ assignment to borrowed `*s` occurs here + | ^^^^^^^^^^^^^^^^^^ assignment to borrowed `*s` occurs here 12 error: aborting due to previous error 13 The actual stderr differed from the expected stderr. Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-loan-of-static-data-issue-27616/borrowck-loan-of-static-data-issue-27616.stderr To update references, rerun the tests and pass the `--bless` flag To only update this specific test, also pass `--test-args borrowck/borrowck-loan-of-static-data-issue-27616.rs` error: 1 errors occurred comparing output. status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/borrowck/borrowck-loan-of-static-data-issue-27616.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-loan-of-static-data-issue-27616" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-loan-of-static-data-issue-27616/auxiliary" stdout: none --- stderr ------------------------------- error[E0506]: cannot assign to `*s` because it is borrowed | LL | let alias: &'static mut String = s; LL | let alias: &'static mut String = s; | ------------------- - borrow of `*s` occurs here | | | type annotation requires that `*s` is borrowed for `'static` ... LL | *s = String::new(); //~ ERROR cannot assign | ^^^^^^^^^^^^^^^^^^ assignment to borrowed `*s` occurs here error: aborting due to previous error For more information about this error, try `rustc --explain E0506`. ------------------------------------------ ------------------------------------------ ---- [ui] checkout/tests/ui/borrowck/borrowck-no-cycle-in-exchange-heap.rs stdout ---- diff of stderr: 4 LL | Cycle::Node(ref mut y) => { 5 | --------- borrow of `x.0` occurs here 6 LL | y.a = x; - | --- ^ move out of `x` occurs here + | ------^ + | | | + | | | + | | move out of `x` occurs here 10 11 error: aborting due to previous error The actual stderr differed from the expected stderr. Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-no-cycle-in-exchange-heap/borrowck-no-cycle-in-exchange-heap.stderr To update references, rerun the tests and pass the `--bless` flag To only update this specific test, also pass `--test-args borrowck/borrowck-no-cycle-in-exchange-heap.rs` error: 1 errors occurred comparing output. status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/borrowck/borrowck-no-cycle-in-exchange-heap.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-no-cycle-in-exchange-heap" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-no-cycle-in-exchange-heap/auxiliary" stdout: none --- stderr ------------------------------- error[E0505]: cannot move out of `x` because it is borrowed | | LL | Cycle::Node(ref mut y) => { | --------- borrow of `x.0` occurs here LL | y.a = x; //~ ERROR cannot move out of | | | | | | | | move out of `x` occurs here error: aborting due to previous error For more information about this error, try `rustc --explain E0505`. --- diff of stderr: 7 LL | drop(t); 8 | - value moved here 9 LL | t.b = Some(u); + | ^^^^^^^^^^^^^ value assigned here after move 11 12 error[E0382]: assign of moved value: `t` 13 --> $DIR/borrowck-partial-reinit-1.rs:33:5 13 --> $DIR/borrowck-partial-reinit-1.rs:33:5 18 LL | drop(t); 19 | - value moved here 20 LL | t.0 = Some(u); + | ^^^^^^^^^^^^^ value assigned here after move 22 23 error: aborting due to 2 previous errors 24 24 The actual stderr differed from the expected stderr. Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-partial-reinit-1/borrowck-partial-reinit-1.stderr To only update this specific test, also pass `--test-args borrowck/borrowck-partial-reinit-1.rs` error: 1 errors occurred comparing output. status: exit status: 1 status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/borrowck/borrowck-partial-reinit-1.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-partial-reinit-1" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-partial-reinit-1/auxiliary" stdout: none --- stderr ------------------------------- error[E0382]: assign of moved value: `t` | | LL | let mut t = Test2 { b: None }; | ----- move occurs because `t` has type `Test2`, which does not implement the `Copy` trait LL | let u = Test; LL | drop(t); | - value moved here LL | t.b = Some(u); error[E0382]: assign of moved value: `t` --> /checkout/tests/ui/borrowck/borrowck-partial-reinit-1.rs:33:5 | | LL | let mut t = Test3(None); | ----- move occurs because `t` has type `Test3`, which does not implement the `Copy` trait LL | let u = Test; LL | drop(t); | - value moved here LL | t.0 = Some(u); error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0382`. For more information about this error, try `rustc --explain E0382`. ------------------------------------------ ---- [ui] checkout/tests/ui/borrowck/borrowck-partial-reinit-4.rs stdout ---- diff of stderr: 4 LL | let mut x : (Test2, Test2); 5 | ----- binding declared here but left uninitialized 6 LL | (x.0).0 = Some(Test); - | ^^^^^^^ `x.0` assigned here but it isn't fully initialized + | ^^^^^^^^^^^^^^^^^^^^ `x.0` assigned here but it isn't fully initialized 8 | 9 = help: partial initialization isn't supported, fully initialize the binding with a default value and mutate it, or use `std::mem::MaybeUninit` The actual stderr differed from the expected stderr. The actual stderr differed from the expected stderr. Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-partial-reinit-4/borrowck-partial-reinit-4.stderr To only update this specific test, also pass `--test-args borrowck/borrowck-partial-reinit-4.rs` error: 1 errors occurred comparing output. status: exit status: 1 status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/borrowck/borrowck-partial-reinit-4.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-partial-reinit-4" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-partial-reinit-4/auxiliary" stdout: none --- stderr ------------------------------- error[E0381]: assigned binding `x.0` isn't fully initialized | | LL | let mut x : (Test2, Test2); | ----- binding declared here but left uninitialized LL | (x.0).0 = Some(Test); //~ ERROR E0381 | ^^^^^^^^^^^^^^^^^^^^ `x.0` assigned here but it isn't fully initialized | = help: partial initialization isn't supported, fully initialize the binding with a default value and mutate it, or use `std::mem::MaybeUninit` error: aborting due to previous error For more information about this error, try `rustc --explain E0381`. ------------------------------------------ ------------------------------------------ ---- [ui] checkout/tests/ui/borrowck/borrowck-partial-reinit-2.rs stdout ---- diff of stderr: 6 LL | let mut u = Test { a: 2, b: Some(Box::new(t))}; 7 | - value moved here 8 LL | t.b = Some(Box::new(u)); + | ^^^^^^^^^^^^^^^^^^^^^^^ value assigned here after move 10 11 error: aborting due to previous error 12 12 The actual stderr differed from the expected stderr. Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-partial-reinit-2/borrowck-partial-reinit-2.stderr To only update this specific test, also pass `--test-args borrowck/borrowck-partial-reinit-2.rs` error: 1 errors occurred comparing output. status: exit status: 1 status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/borrowck/borrowck-partial-reinit-2.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-partial-reinit-2" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-partial-reinit-2/auxiliary" stdout: none --- stderr ------------------------------- error[E0382]: assign of moved value: `t` | | LL | let mut t = Test { a: 1, b: None}; | ----- move occurs because `t` has type `Test`, which does not implement the `Copy` trait LL | let mut u = Test { a: 2, b: Some(Box::new(t))}; | - value moved here LL | t.b = Some(Box::new(u)); error: aborting due to previous error For more information about this error, try `rustc --explain E0382`. For more information about this error, try `rustc --explain E0382`. ------------------------------------------ ---- [ui] checkout/tests/ui/borrowck/borrowck-vec-pattern-nesting.rs stdout ---- diff of stderr: 5 | ------ borrow of `vec[_]` occurs here 6 LL | 7 LL | vec[0] = Box::new(4); - | ^^^^^^ assignment to borrowed `vec[_]` occurs here + | ^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `vec[_]` occurs here 9 LL | 10 LL | _a.use_ref(); 17 | ------ borrow of `vec[_]` occurs here 18 LL | 19 LL | vec[0] = Box::new(4); - | ^^^^^^ assignment to borrowed `vec[_]` occurs here + | ^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `vec[_]` occurs here 21 LL | 22 LL | _b.use_ref(); The actual stderr differed from the expected stderr. Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-vec-pattern-nesting/borrowck-vec-pattern-nesting.stderr Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-vec-pattern-nesting/borrowck-vec-pattern-nesting.stderr To update references, rerun the tests and pass the `--bless` flag To only update this specific test, also pass `--test-args borrowck/borrowck-vec-pattern-nesting.rs` error: 1 errors occurred comparing output. status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/borrowck/borrowck-vec-pattern-nesting.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-vec-pattern-nesting" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/borrowck-vec-pattern-nesting/auxiliary" stdout: none --- stderr ------------------------------- error[E0506]: cannot assign to `vec[_]` because it is borrowed | | LL | [box ref _a, _, _] => { | ------ borrow of `vec[_]` occurs here LL | //~^ NOTE borrow of `vec[_]` occurs here LL | vec[0] = Box::new(4); //~ ERROR cannot assign | ^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `vec[_]` occurs here LL | //~^ NOTE assignment to borrowed `vec[_]` occurs here LL | _a.use_ref(); error[E0506]: cannot assign to `vec[_]` because it is borrowed | | LL | &mut [ref _b @ ..] => { | ------ borrow of `vec[_]` occurs here LL | //~^ borrow of `vec[_]` occurs here LL | vec[0] = Box::new(4); //~ ERROR cannot assign | ^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `vec[_]` occurs here LL | //~^ NOTE assignment to borrowed `vec[_]` occurs here LL | _b.use_ref(); error[E0508]: cannot move out of type `[Box<isize>]`, a non-copy slice | LL | match vec { | ^^^ cannot move out of here ... ... LL | &mut [_a, | -- | | | data moved here | move occurs because `_a` has type `Box<isize>`, which does not implement the `Copy` trait help: consider removing the mutable borrow | LL - &mut [_a, LL + [_a, LL + [_a, | error[E0508]: cannot move out of type `[Box<isize>]`, a non-copy slice | | LL | let a = vec[0]; //~ ERROR cannot move out | | | cannot move out of here | cannot move out of here | move occurs because `vec[_]` has type `Box<isize>`, which does not implement the `Copy` trait help: consider borrowing here | | LL | let a = &vec[0]; //~ ERROR cannot move out error[E0508]: cannot move out of type `[Box<isize>]`, a non-copy slice | LL | match vec { | ^^^ cannot move out of here ... ... LL | _b] => {} | | | data moved here | data moved here | move occurs because `_b` has type `Box<isize>`, which does not implement the `Copy` trait help: consider removing the mutable borrow | LL - &mut [ LL + [ LL + [ | error[E0508]: cannot move out of type `[Box<isize>]`, a non-copy slice | | LL | let a = vec[0]; //~ ERROR cannot move out | | | cannot move out of here | cannot move out of here | move occurs because `vec[_]` has type `Box<isize>`, which does not implement the `Copy` trait help: consider borrowing here | | LL | let a = &vec[0]; //~ ERROR cannot move out error[E0508]: cannot move out of type `[Box<isize>]`, a non-copy slice | LL | match vec { | ^^^ cannot move out of here ... ... LL | &mut [_a, _b, _c] => {} | -- -- -- ...and here | | | | | ...and here | data moved here = note: move occurs because these variables have types that don't implement the `Copy` trait help: consider removing the mutable borrow | | LL - &mut [_a, _b, _c] => {} LL + [_a, _b, _c] => {} error[E0508]: cannot move out of type `[Box<isize>]`, a non-copy slice | | LL | let a = vec[0]; //~ ERROR cannot move out | | | cannot move out of here | cannot move out of here | move occurs because `vec[_]` has type `Box<isize>`, which does not implement the `Copy` trait help: consider borrowing here | | LL | let a = &vec[0]; //~ ERROR cannot move out error: aborting due to 8 previous errors Some errors have detailed explanations: E0506, E0508. --- diff of stderr: 14 --> $DIR/index-mut-help.rs:11:5 15 | 16 LL | map["peter"] = "0".to_string(); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot assign 18 | 18 | 19 = help: trait `IndexMut` is required to modify indexed content, but it is not implemented for `HashMap<&str, String>` 20 help: to modify a `HashMap<&str, String>`, use `.get_mut()`, `.insert()` or the entry API The actual stderr differed from the expected stderr. Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/index-mut-help/index-mut-help.stderr To update references, rerun the tests and pass the `--bless` flag To update references, rerun the tests and pass the `--bless` flag To only update this specific test, also pass `--test-args borrowck/index-mut-help.rs` error: 1 errors occurred comparing output. status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/borrowck/index-mut-help.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/index-mut-help" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/index-mut-help/auxiliary" stdout: none --- stderr ------------------------------- error[E0596]: cannot borrow data in an index of `HashMap<&str, String>` as mutable | | LL | map["peter"].clear(); //~ ERROR | ^^^^^^^^^^^^^^^^^^^^ cannot borrow as mutable | = help: trait `IndexMut` is required to modify indexed content, but it is not implemented for `HashMap<&str, String>` help: to modify a `HashMap<&str, String>` use `.get_mut()` | LL | map.get_mut("peter").map(|val| val.clear()); //~ ERROR error[E0594]: cannot assign to data in an index of `HashMap<&str, String>` | | LL | map["peter"] = "0".to_string(); //~ ERROR | | = help: trait `IndexMut` is required to modify indexed content, but it is not implemented for `HashMap<&str, String>` help: to modify a `HashMap<&str, String>`, use `.get_mut()`, `.insert()` or the entry API | LL | map.insert("peter", "0".to_string()); //~ ERROR | ~~~~~~~~ ~ + LL | map.get_mut("peter").map(|val| { *val = "0".to_string(); }); //~ ERROR | ~~~~~~~~~ ~~~~~~~~~~~~~~~~~~ ++++ LL | let val = map.entry("peter").or_insert("0".to_string()); //~ ERROR error[E0596]: cannot borrow data in an index of `HashMap<&str, String>` as mutable | | LL | let _ = &mut map["peter"]; //~ ERROR | ^^^^^^^^^^^^^^^^^ cannot borrow as mutable | = help: trait `IndexMut` is required to modify indexed content, but it is not implemented for `HashMap<&str, String>` = help: to modify a `HashMap<&str, String>`, use `.get_mut()`, `.insert()` or the entry API error: aborting due to 3 previous errors Some errors have detailed explanations: E0594, E0596. For more information about an error, try `rustc --explain E0594`. --- diff of stderr: 5 | - help: consider making this binding mutable: `mut b` 6 ... 7 LL | b = Box::new(1); - | - first assignment to `b` + | --------------- first assignment to `b` 9 LL | b = Box::new(2); - | ^ cannot assign twice to immutable variable + | ^^^^^^^^^^^^^^^ cannot assign twice to immutable variable 12 error[E0384]: cannot assign twice to immutable variable `b` 13 --> $DIR/issue-45199.rs:14:5 19 | help: consider making this binding mutable: `mut b` 19 | help: consider making this binding mutable: `mut b` 20 ... 21 LL | b = Box::new(2); - | ^ cannot assign twice to immutable variable + | ^^^^^^^^^^^^^^^ cannot assign twice to immutable variable 24 error[E0384]: cannot assign to immutable argument `b` 25 --> $DIR/issue-45199.rs:20:5 28 | - help: consider making this binding mutable: `mut b` 28 | - help: consider making this binding mutable: `mut b` 29 LL | 30 LL | b = Box::new(2); - | ^ cannot assign to immutable argument + | ^^^^^^^^^^^^^^^ cannot assign to immutable argument 33 error: aborting due to 3 previous errors 34 The actual stderr differed from the expected stderr. Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/issue-45199/issue-45199.stderr To update references, rerun the tests and pass the `--bless` flag To only update this specific test, also pass `--test-args borrowck/issue-45199.rs` error: 1 errors occurred comparing output. status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/borrowck/issue-45199.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/issue-45199" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/issue-45199/auxiliary" stdout: none --- stderr ------------------------------- error[E0384]: cannot assign twice to immutable variable `b` | | LL | let b: Box<isize>; | - help: consider making this binding mutable: `mut b` ... LL | b = Box::new(1); //~ NOTE first assignment | --------------- first assignment to `b` LL | b = Box::new(2); //~ ERROR cannot assign twice to immutable variable `b` | ^^^^^^^^^^^^^^^ cannot assign twice to immutable variable error[E0384]: cannot assign twice to immutable variable `b` --> /checkout/tests/ui/borrowck/issue-45199.rs:14:5 | | LL | let b = Box::new(1); //~ NOTE first assignment | | | first assignment to `b` | help: consider making this binding mutable: `mut b` ... ... LL | b = Box::new(2); //~ ERROR cannot assign twice to immutable variable `b` | ^^^^^^^^^^^^^^^ cannot assign twice to immutable variable error[E0384]: cannot assign to immutable argument `b` --> /checkout/tests/ui/borrowck/issue-45199.rs:20:5 | | LL | fn test_args(b: Box<i32>) { //~ HELP consider making this binding mutable | - help: consider making this binding mutable: `mut b` LL | //~| SUGGESTION mut b LL | b = Box::new(2); //~ ERROR cannot assign to immutable argument `b` | ^^^^^^^^^^^^^^^ cannot assign to immutable argument error: aborting due to 3 previous errors For more information about this error, try `rustc --explain E0384`. ------------------------------------------ ------------------------------------------ ---- [ui] checkout/tests/ui/borrowck/issue-58776-borrowck-scans-children.rs stdout ---- diff of stderr: 7 | borrow of `greeting` occurs here 8 LL | 9 LL | greeting = "DEALLOCATED".to_string(); - | ^^^^^^^^ assignment to borrowed `greeting` occurs here + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `greeting` occurs here 11 ... 12 LL | println!("thread result: {:?}", res); 14 14 - error[E0505]: cannot move out of `greeting` because it is borrowed - --> $DIR/issue-58776-borrowck-scans-children.rs:7:10 - | - LL | let res = (|| (|| &greeting)())(); - | -- -------- borrow occurs due to use in closure - | | - | borrow of `greeting` occurs here - ... - LL | drop(greeting); - | ^^^^^^^^ move out of `greeting` occurs here - ... - LL | println!("thread result: {:?}", res); + error: aborting due to previous error 28 - error: aborting due to 2 previous errors - --- To only update this specific test, also pass `--test-args borrowck/issue-58776-borrowck-scans-children.rs` error: 1 errors occurred comparing output. status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/borrowck/issue-58776-borrowck-scans-children.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/issue-58776-borrowck-scans-children" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/borrowck/issue-58776-borrowck-scans-children/auxiliary" stdout: none --- stderr ------------------------------- error[E0506]: cannot assign to `greeting` because it is borrowed | | LL | let res = (|| (|| &greeting)())(); | -- -------- borrow occurs due to use in closure | | | borrow of `greeting` occurs here LL | LL | greeting = "DEALLOCATED".to_string(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `greeting` occurs here ... LL | println!("thread result: {:?}", res); error: aborting due to previous error For more information about this error, try `rustc --explain E0506`. For more information about this error, try `rustc --explain E0506`. ------------------------------------------ ---- [ui] checkout/tests/ui/c-variadic/variadic-ffi-4.rs stdout ---- diff of stderr: 55 | | 56 | has type `&mut VaListImpl<'1>` 57 LL | *ap0 = ap1; - | ^^^^ assignment requires that `'1` must outlive `'2` + | ^^^^^^^^^^ assignment requires that `'1` must outlive `'2` 59 | 60 = note: requirement occurs because of the type `VaListImpl<'_>`, which makes the generic argument `'_` invariant 61 = note: the struct `VaListImpl<'f>` is invariant over the parameter `'f` 69 | | 70 | has type `&mut VaListImpl<'1>` 71 LL | *ap0 = ap1; 71 LL | *ap0 = ap1; - | ^^^^ assignment requires that `'2` must outlive `'1` + | ^^^^^^^^^^ assignment requires that `'2` must outlive `'1` 73 | 74 = note: requirement occurs because of the type `VaListImpl<'_>`, which makes the generic argument `'_` invariant 75 = note: the struct `VaListImpl<'f>` is invariant over the parameter `'f` The actual stderr differed from the expected stderr. The actual stderr differed from the expected stderr. Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/c-variadic/variadic-ffi-4/variadic-ffi-4.stderr To only update this specific test, also pass `--test-args c-variadic/variadic-ffi-4.rs` error: 1 errors occurred comparing output. status: exit status: 1 status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/c-variadic/variadic-ffi-4.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/c-variadic/variadic-ffi-4" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/c-variadic/variadic-ffi-4/auxiliary" stdout: none --- stderr ------------------------------- error: lifetime may not live long enough | | LL | pub unsafe extern "C" fn no_escape0<'f>(_: usize, ap: ...) -> VaListImpl<'f> { | -- -- has type `VaListImpl<'1>` | | | lifetime `'f` defined here LL | ap | ^^ function was supposed to return data with lifetime `'1` but it is returning data with lifetime `'f` | = note: requirement occurs because of the type `VaListImpl<'_>`, which makes the generic argument `'_` invariant = note: the struct `VaListImpl<'f>` is invariant over the parameter `'f` = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance error: lifetime may not live long enough --> /checkout/tests/ui/c-variadic/variadic-ffi-4.rs:8:5 | | LL | pub unsafe extern "C" fn no_escape0<'f>(_: usize, ap: ...) -> VaListImpl<'f> { | -- -- has type `VaListImpl<'1>` | | | lifetime `'f` defined here LL | ap | ^^ function was supposed to return data with lifetime `'f` but it is returning data with lifetime `'1` | = note: requirement occurs because of the type `VaListImpl<'_>`, which makes the generic argument `'_` invariant = note: the struct `VaListImpl<'f>` is invariant over the parameter `'f` = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance error: lifetime may not live long enough --> /checkout/tests/ui/c-variadic/variadic-ffi-4.rs:14:5 | | LL | pub unsafe extern "C" fn no_escape1(_: usize, ap: ...) -> VaListImpl<'static> { | -- has type `VaListImpl<'1>` LL | ap //~ ERROR: lifetime may not live long enough | ^^ returning this value requires that `'1` must outlive `'static` | = note: requirement occurs because of the type `VaListImpl<'_>`, which makes the generic argument `'_` invariant = note: the struct `VaListImpl<'f>` is invariant over the parameter `'f` = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance error: lifetime may not live long enough --> /checkout/tests/ui/c-variadic/variadic-ffi-4.rs:18:31 | | LL | let _ = ap.with_copy(|ap| ap); //~ ERROR: lifetime may not live long enough | --- ^^ returning this value requires that `'1` must outlive `'2` | | | | | return type of closure is VaList<'2, '_> | has type `VaList<'1, '_>` error: lifetime may not live long enough --> /checkout/tests/ui/c-variadic/variadic-ffi-4.rs:22:5 | | LL | pub unsafe extern "C" fn no_escape3(_: usize, mut ap0: &mut VaListImpl, mut ap1: ...) { | ------- ------- has type `VaListImpl<'2>` | has type `&mut VaListImpl<'1>` LL | *ap0 = ap1; LL | *ap0 = ap1; | ^^^^^^^^^^ assignment requires that `'1` must outlive `'2` | = note: requirement occurs because of the type `VaListImpl<'_>`, which makes the generic argument `'_` invariant = note: the struct `VaListImpl<'f>` is invariant over the parameter `'f` = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance error: lifetime may not live long enough --> /checkout/tests/ui/c-variadic/variadic-ffi-4.rs:22:5 | | LL | pub unsafe extern "C" fn no_escape3(_: usize, mut ap0: &mut VaListImpl, mut ap1: ...) { | ------- ------- has type `VaListImpl<'2>` | has type `&mut VaListImpl<'1>` LL | *ap0 = ap1; LL | *ap0 = ap1; | ^^^^^^^^^^ assignment requires that `'2` must outlive `'1` | = note: requirement occurs because of the type `VaListImpl<'_>`, which makes the generic argument `'_` invariant = note: the struct `VaListImpl<'f>` is invariant over the parameter `'f` = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance error: lifetime may not live long enough --> /checkout/tests/ui/c-variadic/variadic-ffi-4.rs:28:5 | | LL | pub unsafe extern "C" fn no_escape4(_: usize, mut ap0: &mut VaListImpl, mut ap1: ...) { | ------- ------- has type `VaListImpl<'2>` | has type `&mut VaListImpl<'1>` | has type `&mut VaListImpl<'1>` LL | ap0 = &mut ap1; | ^^^^^^^^^^^^^^ assignment requires that `'1` must outlive `'2` | = note: requirement occurs because of a mutable reference to `VaListImpl<'_>` = note: mutable references are invariant over their type parameter = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance error: lifetime may not live long enough --> /checkout/tests/ui/c-variadic/variadic-ffi-4.rs:28:5 | | LL | pub unsafe extern "C" fn no_escape4(_: usize, mut ap0: &mut VaListImpl, mut ap1: ...) { | ------- ------- has type `VaListImpl<'2>` | has type `&mut VaListImpl<'1>` | has type `&mut VaListImpl<'1>` LL | ap0 = &mut ap1; | ^^^^^^^^^^^^^^ assignment requires that `'2` must outlive `'1` | = note: requirement occurs because of a mutable reference to `VaListImpl<'_>` = note: mutable references are invariant over their type parameter = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance error[E0597]: `ap1` does not live long enough | | LL | pub unsafe extern "C" fn no_escape4(_: usize, mut ap0: &mut VaListImpl, mut ap1: ...) { | - let's call the lifetime of this reference `'3` LL | ap0 = &mut ap1; | | | | | borrowed value does not live long enough | | borrowed value does not live long enough | assignment requires that `ap1` is borrowed for `'3` LL | } LL | } | - `ap1` dropped here while still borrowed error: lifetime may not live long enough --> /checkout/tests/ui/c-variadic/variadic-ffi-4.rs:35:12 | | LL | pub unsafe extern "C" fn no_escape5(_: usize, mut ap0: &mut VaListImpl, mut ap1: ...) { | ------- ------- has type `VaListImpl<'2>` | has type `&mut VaListImpl<'1>` | has type `&mut VaListImpl<'1>` LL | *ap0 = ap1.clone(); | ^^^^^^^^^^^ argument requires that `'1` must outlive `'2` | = note: requirement occurs because of the type `VaListImpl<'_>`, which makes the generic argument `'_` invariant = note: the struct `VaListImpl<'f>` is invariant over the parameter `'f` = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance error: lifetime may not live long enough --> /checkout/tests/ui/c-variadic/variadic-ffi-4.rs:35:12 | | LL | pub unsafe extern "C" fn no_escape5(_: usize, mut ap0: &mut VaListImpl, mut ap1: ...) { | ------- ------- has type `VaListImpl<'2>` | has type `&mut VaListImpl<'1>` | has type `&mut VaListImpl<'1>` LL | *ap0 = ap1.clone(); | ^^^^^^^^^^^ argument requires that `'2` must outlive `'1` | = note: requirement occurs because of the type `VaListImpl<'_>`, which makes the generic argument `'_` invariant = note: the struct `VaListImpl<'f>` is invariant over the parameter `'f` = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance error: aborting due to 11 previous errors For more information about this error, try `rustc --explain E0597`. ------------------------------------------ ------------------------------------------ ---- [ui] checkout/tests/ui/closures/2229_closure_analysis/diagnostics/box.rs stdout ---- diff of stderr: 7 | --------- borrow occurs due to use in closure 8 ... 9 LL | e.0.0.m.x = format!("not-x"); - | ^^^^^^^^^ assignment to borrowed `e.0.0.m.x` occurs here + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `e.0.0.m.x` occurs here 12 LL | c(); 13 | - borrow later used here 37 | --------- borrow occurs due to use in closure 37 | --------- borrow occurs due to use in closure 38 ... 39 LL | e.0.0.m.x = format!("not-x"); - | ^^^^^^^^^ assignment to borrowed `e.0.0.m.x` occurs here + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `e.0.0.m.x` occurs here 42 LL | c(); 43 | - borrow later used here The actual stderr differed from the expected stderr. Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/closures/2229_closure_analysis/diagnostics/box/box.stderr To update references, rerun the tests and pass the `--bless` flag To only update this specific test, also pass `--test-args closures/2229_closure_analysis/diagnostics/box.rs` error: 1 errors occurred comparing output. status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/closures/2229_closure_analysis/diagnostics/box.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/closures/2229_closure_analysis/diagnostics/box" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/closures/2229_closure_analysis/diagnostics/box/auxiliary" "--edition=2021" stdout: none --- stderr ------------------------------- error[E0506]: cannot assign to `e.0.0.m.x` because it is borrowed | LL | let mut c = || { LL | let mut c = || { | -- borrow of `e.0.0.m.x` occurs here LL | e.0.0.m.x = format!("not-x"); | --------- borrow occurs due to use in closure ... LL | e.0.0.m.x = format!("not-x"); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `e.0.0.m.x` occurs here LL | //~^ ERROR: cannot assign to `e.0.0.m.x` because it is borrowed LL | c(); error[E0502]: cannot borrow `e.0.0.m.x` as immutable because it is also borrowed as mutable | LL | let mut c = || { LL | let mut c = || { | -- mutable borrow occurs here LL | e.0.0.m.x = format!("not-x"); | --------- first borrow occurs due to use of `e.0.0.m.x` in closure ... LL | println!("{}", e.0.0.m.x); | ^^^^^^^^^ immutable borrow occurs here LL | //~^ ERROR: cannot borrow `e.0.0.m.x` as immutable because it is also borrowed as mutable LL | c(); | = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info) error[E0506]: cannot assign to `e.0.0.m.x` because it is borrowed | LL | let c = || { LL | let c = || { | -- borrow of `e.0.0.m.x` occurs here LL | println!("{}", e.0.0.m.x); | --------- borrow occurs due to use in closure ... LL | e.0.0.m.x = format!("not-x"); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `e.0.0.m.x` occurs here LL | //~^ ERROR: cannot assign to `e.0.0.m.x` because it is borrowed LL | c(); error: aborting due to 3 previous errors Some errors have detailed explanations: E0502, E0506. --- diff of stderr: 2 --> $DIR/const_let.rs:16:32 3 | 4 LL | const Y: FakeNeedsDrop = { let mut x = FakeNeedsDrop; x = FakeNeedsDrop; x }; - | ^^^^^ - value is dropped here + | ^^^^^ ----------------- value is dropped here 7 | the destructor for this type cannot be evaluated in constants 8 10 --> $DIR/const_let.rs:20:33 10 --> $DIR/const_let.rs:20:33 11 | 12 LL | const Y2: FakeNeedsDrop = { let mut x; x = FakeNeedsDrop; x = FakeNeedsDrop; x }; - | ^^^^^ - value is dropped here + | ^^^^^ ----------------- value is dropped here 15 | the destructor for this type cannot be evaluated in constants 16 The actual stderr differed from the expected stderr. Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/consts/const-eval/const_let/const_let.stderr To update references, rerun the tests and pass the `--bless` flag To only update this specific test, also pass `--test-args consts/const-eval/const_let.rs` error: 1 errors occurred comparing output. status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/consts/const-eval/const_let.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/consts/const-eval/const_let" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/consts/const-eval/const_let/auxiliary" stdout: none --- stderr ------------------------------- error[E0493]: destructor of `FakeNeedsDrop` cannot be evaluated at compile-time | | LL | const Y: FakeNeedsDrop = { let mut x = FakeNeedsDrop; x = FakeNeedsDrop; x }; | ^^^^^ ----------------- value is dropped here | the destructor for this type cannot be evaluated in constants error[E0493]: destructor of `FakeNeedsDrop` cannot be evaluated at compile-time | | LL | const Y2: FakeNeedsDrop = { let mut x; x = FakeNeedsDrop; x = FakeNeedsDrop; x }; | ^^^^^ ----------------- value is dropped here | the destructor for this type cannot be evaluated in constants error[E0493]: destructor of `Option<FakeNeedsDrop>` cannot be evaluated at compile-time | | LL | const Z: () = { let mut x = None; x = Some(FakeNeedsDrop); }; | ^^^^^ - value is dropped here | the destructor for this type cannot be evaluated in constants error[E0493]: destructor of `Option<FakeNeedsDrop>` cannot be evaluated at compile-time | | LL | const Z2: () = { let mut x; x = None; x = Some(FakeNeedsDrop); }; | ^^^^^ - value is dropped here | the destructor for this type cannot be evaluated in constants error: aborting due to 4 previous errors --- diff of stderr: 5 | ^^^^^^^^^^^^^^^^^^^ the destructor for this type cannot be evaluated in constants 6 ... 7 LL | always_returned = never_returned; - | --------------- value is dropped here + | -------------------------------- value is dropped here 10 error: aborting due to previous error 11 The actual stderr differed from the expected stderr. Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/consts/const-eval/livedrop/livedrop.stderr To update references, rerun the tests and pass the `--bless` flag To only update this specific test, also pass `--test-args consts/const-eval/livedrop.rs` error: 1 errors occurred comparing output. status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/consts/const-eval/livedrop.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/consts/const-eval/livedrop" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/consts/const-eval/livedrop/auxiliary" stdout: none --- stderr ------------------------------- error[E0493]: destructor of `Option<Vec<i32>>` cannot be evaluated at compile-time | | LL | let mut always_returned = None; //~ ERROR destructor of | ^^^^^^^^^^^^^^^^^^^ the destructor for this type cannot be evaluated in constants LL | always_returned = never_returned; LL | always_returned = never_returned; | -------------------------------- value is dropped here error: aborting due to previous error For more information about this error, try `rustc --explain E0493`. ------------------------------------------ ------------------------------------------ ---- [ui] checkout/tests/ui/liveness/liveness-assign/liveness-assign-imm-local-with-drop.rs stdout ---- diff of stderr: 8 | help: consider making this binding mutable: `mut b` 9 ... 10 LL | b = Box::new(2); - | ^ cannot assign twice to immutable variable + | ^^^^^^^^^^^^^^^ cannot assign twice to immutable variable 13 error: aborting due to previous error 14 The actual stderr differed from the expected stderr. Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/liveness/liveness-assign/liveness-assign-imm-local-with-drop/liveness-assign-imm-local-with-drop.stderr To update references, rerun the tests and pass the `--bless` flag To only update this specific test, also pass `--test-args liveness/liveness-assign/liveness-assign-imm-local-with-drop.rs` error: 1 errors occurred comparing output. status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/liveness/liveness-assign/liveness-assign-imm-local-with-drop.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/liveness/liveness-assign/liveness-assign-imm-local-with-drop" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/liveness/liveness-assign/liveness-assign-imm-local-with-drop/auxiliary" stdout: none --- stderr ------------------------------- error[E0384]: cannot assign twice to immutable variable `b` | | LL | let b = Box::new(1); //~ NOTE first assignment | | | first assignment to `b` | help: consider making this binding mutable: `mut b` ... ... LL | b = Box::new(2); //~ ERROR cannot assign twice to immutable variable `b` | ^^^^^^^^^^^^^^^ cannot assign twice to immutable variable error: aborting due to previous error For more information about this error, try `rustc --explain E0384`. ------------------------------------------ ------------------------------------------ ---- [ui] checkout/tests/ui/mir/drop-elaboration-after-borrowck-error.rs stdout ---- diff of stderr: 2 --> $DIR/drop-elaboration-after-borrowck-error.rs:7:5 3 | 4 LL | a[0] = String::new(); + | ^^^^^^^^^^^^^^^^^^^^ 6 | | 7 | the destructor for this type cannot be evaluated in statics 8 | value is dropped here 8 | value is dropped here 34 --> $DIR/drop-elaboration-after-borrowck-error.rs:18:9 35 | 36 LL | self.0[0] = other; + | ^^^^^^^^^^^^^^^^^ 38 | | 39 | the destructor for this type cannot be evaluated in constant functions 40 | value is dropped here --- To only update this specific test, also pass `--test-args mir/drop-elaboration-after-borrowck-error.rs` error: 1 errors occurred comparing output. status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/mir/drop-elaboration-after-borrowck-error.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/mir/drop-elaboration-after-borrowck-error" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/mir/drop-elaboration-after-borrowck-error/auxiliary" stdout: none --- stderr ------------------------------- error[E0493]: destructor of `String` cannot be evaluated at compile-time | | LL | a[0] = String::new(); | | | the destructor for this type cannot be evaluated in statics | value is dropped here error[E0493]: destructor of `[String; 1]` cannot be evaluated at compile-time | | LL | let a: [String; 1]; | ^ the destructor for this type cannot be evaluated in statics LL | }; LL | }; | - value is dropped here error[E0381]: used binding `a` isn't initialized --> /checkout/tests/ui/mir/drop-elaboration-after-borrowck-error.rs:7:5 | | LL | let a: [String; 1]; | - binding declared here but left uninitialized LL | //~^ ERROR destructor of LL | a[0] = String::new(); | ^^^^ `a` used here but it isn't initialized help: consider assigning a value | | LL | let a: [String; 1] = todo!(); error[E0493]: destructor of `T` cannot be evaluated at compile-time | | LL | self.0[0] = other; | | | the destructor for this type cannot be evaluated in constant functions | value is dropped here error[E0493]: destructor of `B<T>` cannot be evaluated at compile-time | LL | let _this = self; | ^^^^^ the destructor for this type cannot be evaluated in constant functions ... ... LL | } | - value is dropped here error[E0382]: use of moved value: `self.0` --> /checkout/tests/ui/mir/drop-elaboration-after-borrowck-error.rs:18:9 | LL | pub const fn f(mut self, other: T) -> Self { | -------- move occurs because `self` has type `B<T>`, which does not implement the `Copy` trait LL | let _this = self; | ---- value moved here LL | //~^ ERROR destructor of LL | self.0[0] = other; | ^^^^^^^^^ value used here after move error: aborting due to 6 previous errors Some errors have detailed explanations: E0381, E0382, E0493. For more information about an error, try `rustc --explain E0381`. For more information about an error, try `rustc --explain E0381`. ------------------------------------------ ---- [ui] checkout/tests/ui/nll/issue-27868.rs stdout ---- diff of stderr: 7 | _____borrow of `vecvec` occurs here 8 | | 9 LL | | vecvec = vec![]; - | | ^^^^^^ assignment to borrowed `vecvec` occurs here + | | ^^^^^^^^^^^^^^^ assignment to borrowed `vecvec` occurs here 11 LL | | 12 LL | | 0 13 LL | | }; The actual stderr differed from the expected stderr. Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/nll/issue-27868/issue-27868.stderr To update references, rerun the tests and pass the `--bless` flag To update references, rerun the tests and pass the `--bless` flag To only update this specific test, also pass `--test-args nll/issue-27868.rs` error: 1 errors occurred comparing output. status: exit status: 1 status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/nll/issue-27868.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/nll/issue-27868" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/nll/issue-27868/auxiliary" stdout: none --- stderr ------------------------------- error[E0506]: cannot assign to `vecvec` because it is borrowed | | LL | vecvec[0] += { | | | | | _____borrow of `vecvec` occurs here | | LL | | vecvec = vec![]; | | ^^^^^^^^^^^^^^^ assignment to borrowed `vecvec` occurs here LL | | //~^ ERROR cannot assign to `vecvec` because it is borrowed [E0506] LL | | 0 LL | | }; | |_____- borrow later used here error: aborting due to previous error For more information about this error, try `rustc --explain E0506`. ------------------------------------------ ------------------------------------------ ---- [ui] checkout/tests/ui/object-lifetime/object-lifetime-default-from-box-error.rs stdout ---- diff of stderr: 25 | --------------- help: add explicit lifetime `'b` to the type of `ss`: `&mut SomeStruct<'b>` 26 ... 27 LL | ss.r = b; - | ^^^^ lifetime `'b` required + | ^^^^^^^^ lifetime `'b` required 30 error: aborting due to 3 previous errors 31 The actual stderr differed from the expected stderr. Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/object-lifetime/object-lifetime-default-from-box-error/object-lifetime-default-from-box-error.stderr To update references, rerun the tests and pass the `--bless` flag To only update this specific test, also pass `--test-args object-lifetime/object-lifetime-default-from-box-error.rs` error: 1 errors occurred comparing output. status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/object-lifetime/object-lifetime-default-from-box-error.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/object-lifetime/object-lifetime-default-from-box-error" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/object-lifetime/object-lifetime-default-from-box-error/auxiliary" stdout: none --- stderr ------------------------------- error: lifetime may not live long enough | | LL | fn load(ss: &mut SomeStruct) -> Box<dyn SomeTrait> { | -- has type `&mut SomeStruct<'1>` LL | ss.r LL | ss.r | ^^^^ returning this value requires that `'1` must outlive `'static` | help: to declare that the trait object captures data from argument `ss`, you can add an explicit `'_` lifetime bound | LL | fn load(ss: &mut SomeStruct) -> Box<dyn SomeTrait + '_> { error[E0507]: cannot move out of `ss.r` which is behind a mutable reference | LL | ss.r LL | ss.r | ^^^^ move occurs because `ss.r` has type `Box<dyn SomeTrait>`, which does not implement the `Copy` trait error[E0621]: explicit lifetime required in the type of `ss` | | LL | fn store1<'b>(ss: &mut SomeStruct, b: Box<dyn SomeTrait+'b>) { | --------------- help: add explicit lifetime `'b` to the type of `ss`: `&mut SomeStruct<'b>` ... LL | ss.r = b; //~ ERROR explicit lifetime required in the type of `ss` [E0621] | ^^^^^^^^ lifetime `'b` required error: aborting due to 3 previous errors Some errors have detailed explanations: E0507, E0621. For more information about an error, try `rustc --explain E0507`. For more information about an error, try `rustc --explain E0507`. ------------------------------------------ ---- [ui] checkout/tests/ui/regions/regions-infer-paramd-indirect.rs stdout ---- diff of stderr: 7 LL | fn set_f_bad(&mut self, b: Box<B>) { 8 | - has type `Box<Box<&'1 isize>>` 9 LL | self.f = b; - | ^^^^^^ assignment requires that `'1` must outlive `'a` + | ^^^^^^^^^^ assignment requires that `'1` must outlive `'a` 12 error: aborting due to previous error 13 The actual stderr differed from the expected stderr. Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/regions/regions-infer-paramd-indirect/regions-infer-paramd-indirect.stderr To update references, rerun the tests and pass the `--bless` flag To only update this specific test, also pass `--test-args regions/regions-infer-paramd-indirect.rs` error: 1 errors occurred comparing output. status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/regions/regions-infer-paramd-indirect.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/regions/regions-infer-paramd-indirect" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/regions/regions-infer-paramd-indirect/auxiliary" stdout: none --- stderr ------------------------------- error: lifetime may not live long enough | | LL | impl<'a> SetF<'a> for C<'a> { | -- lifetime `'a` defined here ... LL | fn set_f_bad(&mut self, b: Box<B>) { | - has type `Box<Box<&'1 isize>>` LL | self.f = b; | ^^^^^^^^^^ assignment requires that `'1` must outlive `'a` error: aborting due to previous error ------------------------------------------ --- 23 LL | factorial = Some(Box::new(f)); - | ^^^^^^^^^ + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 25 | | 26 | assignment to borrowed `factorial` occurs here 52 | --------- borrow occurs due to use in closure 53 ... 54 LL | factorial = Some(Box::new(f)); 54 LL | factorial = Some(Box::new(f)); - | ^^^^^^^^^ assignment to borrowed `factorial` occurs here + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `factorial` occurs here 57 error: aborting due to 4 previous errors 58 The actual stderr differed from the expected stderr. Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1/unboxed-closures-failed-recursive-fn-1.stderr To only update this specific test, also pass `--test-args unboxed-closures/unboxed-closures-failed-recursive-fn-1.rs` error: 1 errors occurred comparing output. status: exit status: 1 status: exit status: 1 command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Zdeduplicate-diagnostics=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1" "-A" "unused" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1/auxiliary" stdout: none --- stderr ------------------------------- error[E0597]: `factorial` does not live long enough | | 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 `Option<Box<dyn Fn(u32) -> u32>>` error[E0506]: cannot assign to `factorial` because it is borrowed | | 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 error[E0597]: `factorial` does not live long enough | | LL | let mut factorial: Option<Box<dyn Fn(u32) -> u32 + 'static>> = None; | ----------------------------------------- type annotation requires that `factorial` is borrowed for `'static` LL | LL | let f = |x: u32| -> u32 { | --------------- value captured here LL | let g = factorial.as_ref().unwrap(); | ^^^^^^^^^ borrowed value does not live long enough LL | } LL | } | - `factorial` dropped here while still borrowed error[E0506]: cannot assign to `factorial` because it is borrowed | | LL | let mut factorial: Option<Box<dyn Fn(u32) -> u32 + 'static>> = None; | ----------------------------------------- type annotation requires that `factorial` is borrowed for `'static` LL | 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)); LL | factorial = Some(Box::new(f)); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `factorial` occurs 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`. 

[arielb1]

why this change?

[zeegomo]

The variable shouldn't be considered initialized anymore but it's not handled by drop_flag_effects as it's not a move.
I think we can't rely on StorageDead because a drop could panic before reaching that location.

I discovered this problem in

rust/tests/ui/drop/repeat-drop.rs

Line 102 in c8e6a9e

let _v = (DropChecker(1), [panic; 0]);

.
The compiler moves panic into a temp variable, but since the array it's zero sized, that variable never gets moved anywere and it's immediately dropped.

_8 = move _3; // scope 2 at tests/ui/drop/repeat-drop.rs:105:36: 105:41 drop(_8) -> [return: bb1, unwind: bb9]; bb9 (cleanup): { drop(_8) -> bb10; // scope 2 at tests/ui/drop/repeat-drop.rs:105:44: 105:45 } 

When this unwinds _8 is still considered initialized and drop elab does not remove the drop in bb9, which results in a double drop.

Now, not sure that this mir building is ideal (a panic in dropping a local shouldn't unwind to a block that drops the same local), but I think that what I said above about considering a variable uninitialized the moment it gets dropped still holds.

[arielb1]

why this change?

[arielb1]

any reason you changed build_drop_and_replace to only include the sad path replace?

[zeegomo]

Initially I removed all assigns and added the sad path one later. In the happy path you need the assign anyway at call site because you may not emit a replace if the type does not need a drop, so you can just add the assign regardless of whether you created a new block for a drop and replace or not.

Anyway, not a strong opinion, I'll revert to the original behavior

[apiraino]

Switching to waiting on author until all comments are ticked ✔️ . Feel free to request a review with @rustbot ready, thanks!

@rustbot author

[bors]

☔ The latest upstream changes (presumably #107727) made this pull request unmergeable. Please resolve the merge conflicts.

[zeegomo]

Going to close this for now and split into smaller chunks like #107271