Remove uninit drops after building MIR

[cjgillot]

r? @ghost

[cjgillot]

@bors try @rust-timer queue

[rust-bors]

☀️ Try build successful (CI)
Build commit: 71397a5 (71397a59747fe3fec51e3238c9bc2dca5f03997e)
Base parent: 7c329d6 (7c329d6c76e11ca40c5673818ab0439c1be8962c)

[rust-timer]

Finished benchmarking commit (71397a5): comparison URL.

Overall result: ❌✅ regressions and improvements - please read:

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing compiler perf.

Next, please: If you can, justify the regressions found in this try perf run in writing along with @rustbot label: +perf-regression-triaged. If not, fix the regressions and do another perf run. Neutral or positive results will clear the label automatically.

@bors rollup=never rustc-perf
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	1.2%	[0.1%, 4.2%]	82
Regressions ❌ (secondary)	1.1%	[0.2%, 4.2%]	96
Improvements ✅ (primary)	-0.7%	[-1.4%, -0.2%]	20
Improvements ✅ (secondary)	-0.8%	[-2.3%, -0.1%]	18
All ❌✅ (primary)	0.9%	[-1.4%, 4.2%]	102

Max RSS (memory usage)

Results (primary -0.7%, secondary 0.9%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	1.0%	[0.5%, 1.6%]	8
Regressions ❌ (secondary)	2.1%	[0.5%, 6.6%]	8
Improvements ✅ (primary)	-2.1%	[-4.7%, -0.8%]	10
Improvements ✅ (secondary)	-1.0%	[-1.5%, -0.4%]	5
All ❌✅ (primary)	-0.7%	[-4.7%, 1.6%]	18

Cycles

Results (primary 2.6%, secondary 1.5%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	2.9%	[0.5%, 4.8%]	34
Regressions ❌ (secondary)	2.4%	[0.4%, 5.5%]	23
Improvements ✅ (primary)	-1.4%	[-2.6%, -0.5%]	3
Improvements ✅ (secondary)	-0.8%	[-2.7%, -0.4%]	10
All ❌✅ (primary)	2.6%	[-2.6%, 4.8%]	37

Binary size

Results (primary -0.5%, secondary -0.4%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	0.1%	[0.0%, 0.5%]	6
Regressions ❌ (secondary)	0.5%	[0.5%, 0.5%]	3
Improvements ✅ (primary)	-0.5%	[-2.7%, -0.0%]	106
Improvements ✅ (secondary)	-0.5%	[-2.7%, -0.0%]	53
All ❌✅ (primary)	-0.5%	[-2.7%, 0.5%]	112

Bootstrap: 491.018s -> 509.55s (3.77%)
Artifact size: 390.29 MiB -> 390.17 MiB (-0.03%)

[cjgillot]

@bors try @rust-timer queue

[rust-log-analyzer]

The job x86_64-gnu-next-trait-solver-polonius failed! Check out the build log: (web) (plain enhanced) (plain)

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

failures:

---- [ui (polonius)] tests/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1.rs stdout ----
Saved the actual stderr to `/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1.polonius/unboxed-closures-failed-recursive-fn-1.polonius.stderr`
diff of stderr:

- error[E0597]: `factorial` does not live long enough
-   --> $DIR/unboxed-closures-failed-recursive-fn-1.rs:15:17
-    |
- LL |     let mut factorial: Option<Box<dyn Fn(u32) -> u32>> = None;
-    |         ------------- binding `factorial` declared here
- 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 | }
-    | -
-    | |
-    | `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>>`
- 
18 error[E0506]: cannot assign to `factorial` because it is borrowed
19   --> $DIR/unboxed-closures-failed-recursive-fn-1.rs:20:5
20    |

29    |     `factorial` is assigned to here but it was already borrowed
30    |     borrow later used here
31 
- error[E0597]: `factorial` does not live long enough
-   --> $DIR/unboxed-closures-failed-recursive-fn-1.rs:28:17
-    |
- LL |     let mut factorial: Option<Box<dyn Fn(u32) -> u32 + 'static>> = None;
-    |         -------------  ----------------------------------------- type annotation requires that `factorial` is borrowed for `'static`
-    |         |
-    |         binding `factorial` declared here
- 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 | }
-    | - `factorial` dropped here while still borrowed
- 
48 error[E0506]: cannot assign to `factorial` because it is borrowed
49   --> $DIR/unboxed-closures-failed-recursive-fn-1.rs:33:5
50    |

---
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
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage1/bin/rustc" "/checkout/tests/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1.rs" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage1" "--target=x86_64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=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.polonius" "-Zpolonius=next" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers"
stdout: none
--- stderr -------------------------------
error[E0506]: cannot assign to `factorial` because it is borrowed
##[error]  --> /checkout/tests/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1.rs:20:5
   |
LL |     let f = |x: u32| -> u32 {
   |             --------------- `factorial` is borrowed here
LL |         let g = factorial.as_ref().unwrap();
   |                 --------- borrow occurs due to use in closure
...
LL |     factorial = Some(Box::new(f));
   |     ^^^^^^^^^
   |     |
   |     `factorial` is assigned to here but it was already borrowed
   |     borrow later used here

error[E0506]: cannot assign to `factorial` because it is borrowed
##[error]  --> /checkout/tests/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1.rs:33:5
   |
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 {
   |             --------------- `factorial` is borrowed here
LL |         let g = factorial.as_ref().unwrap();
   |                 --------- borrow occurs due to use in closure
...
LL |     factorial = Some(Box::new(f));
   |     ^^^^^^^^^ `factorial` is assigned to here but it was already borrowed

error: aborting due to 2 previous errors

Important

For more information how to resolve CI failures of this job, visit this link.

[rust-bors]

☀️ Try build successful (CI)
Build commit: ea35837 (ea358370493e8c9cdc1e5bf91eb9fddb8afbd72e)
Base parent: 5048696 (504869653f510b279c542e65ccd1ea9710c119ba)

[rust-timer]

Finished benchmarking commit (ea35837): comparison URL.

Overall result: ❌ regressions - please read:

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing compiler perf.

Next, please: If you can, justify the regressions found in this try perf run in writing along with @rustbot label: +perf-regression-triaged. If not, fix the regressions and do another perf run. Neutral or positive results will clear the label automatically.

@bors rollup=never rustc-perf
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	0.9%	[0.2%, 2.6%]	88
Regressions ❌ (secondary)	0.9%	[0.2%, 2.5%]	86
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.9%	[0.2%, 2.6%]	88

Max RSS (memory usage)

Results (primary 0.5%, secondary 2.0%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	1.6%	[0.5%, 5.4%]	11
Regressions ❌ (secondary)	2.0%	[0.4%, 6.6%]	12
Improvements ✅ (primary)	-1.4%	[-2.5%, -0.8%]	6
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.5%	[-2.5%, 5.4%]	17

Cycles

Results (primary 1.7%, secondary 5.9%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	2.0%	[0.4%, 3.8%]	15
Regressions ❌ (secondary)	9.2%	[0.5%, 25.0%]	11
Improvements ✅ (primary)	-0.8%	[-1.2%, -0.5%]	2
Improvements ✅ (secondary)	-1.4%	[-4.1%, -0.4%]	5
All ❌✅ (primary)	1.7%	[-1.2%, 3.8%]	17

Binary size

Results (primary -0.0%, secondary -0.4%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	0.2%	[0.1%, 0.8%]	10
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.1%	[-0.3%, -0.0%]	32
Improvements ✅ (secondary)	-0.4%	[-1.1%, -0.0%]	21
All ❌✅ (primary)	-0.0%	[-0.3%, 0.8%]	42

Bootstrap: 491.182s -> 491.564s (0.08%)
Artifact size: 390.23 MiB -> 390.12 MiB (-0.03%)