Return `ExitCode` from `rustc_driver::main` instead of calling `process::exit` #150379

ChrisDenton · 2025-12-25T17:11:27Z

This makes rustc simply return an exit code from main rather than calling std::process::exit with an exit code. This means that drops run normally and the process exits cleanly. This is similar to what happens when an ICE occurs (due to being a panic that's caught by std's lang_start).

Also instead of hard coding success and failure codes this uses ExitCode::SUCCESS and ExitCode::FAILURE, which in turn effectively uses libc::EXIT_SUCCESS and libc::EXIT_FAILURE (via std). These are 0 and 1 respectively for all currently supported host platforms so it doesn't actually change the exit code.

rustbot · 2025-12-25T17:11:31Z

r? @SparrowLii

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rustbot · 2025-12-25T17:28:03Z

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

rustbot · 2025-12-25T17:33:06Z

The Miri subtree was changed

cc @rust-lang/miri

This makes rustc simply return an exit code from main rather than calling `std::process::exit` with an exit code. This means that drops run normally and the process exits cleanly. Also instead of hard coding success and failure codes this uses `ExitCode::SUCCESS` and `ExitCode::FAILURE`, which in turn effectively uses `libc::EXIT_SUCCESS` and `libc::EXIT_FAILURE` (via std). These are `0` and `1` respectively for all currently supported host platforms so it doesn't actually change the exit code.

Kobzol · 2025-12-25T20:28:51Z

@bors try @rust-timer queue

Return `ExitCode` from `rustc_driver::main` instead of calling `process::exit`

rust-bors · 2025-12-25T22:40:15Z

☀️ Try build successful (CI)
Build commit: ffd099f (ffd099ff891368a934635eba38de913f96f6ab17, parent: 1bf12c32a08384862297674921d1137ad94892dc)

rust-timer · 2025-12-25T23:21:33Z

Finished benchmarking commit (ffd099f): comparison URL.

Overall result: ❌✅ regressions and improvements - no action needed

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

@bors rollup=never
@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)	0.2%	[0.2%, 0.2%]	1
Regressions ❌ (secondary)	0.2%	[0.2%, 0.2%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.0%	[-0.1%, -0.0%]	3
All ❌✅ (primary)	0.2%	[0.2%, 0.2%]	1

Max RSS (memory usage)

Results (secondary -1.4%)

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

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	2.2%	[1.6%, 2.4%]	4
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-4.2%	[-5.1%, -3.7%]	5
All ❌✅ (primary)	-	-	0

Cycles

Results (secondary 2.8%)

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

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	4.3%	[2.5%, 6.6%]	7
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.4%	[-2.6%, -2.2%]	2
All ❌✅ (primary)	-	-	0

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 482.343s -> 483.621s (0.26%)
Artifact size: 392.46 MiB -> 390.44 MiB (-0.51%)

src/tools/miri/src/bin/miri.rs

ChrisDenton · 2025-12-26T18:46:55Z

src/tools/miri/src/bin/miri.rs

+    exit(if exit_code == ExitCode::SUCCESS {
+        rustc_driver::EXIT_SUCCESS
+    } else {
+        rustc_driver::EXIT_FAILURE
+    })


Annoyingly ExitCode does not have a method to convert it to the i32 that process::exit requires. I think this is a libs issue that should be addressed.

Yeah that is unfortunate.

Either way, 👍 for the Miri changes.

rustbot assigned SparrowLii Dec 25, 2025

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. T-rustdoc Relevant to the rustdoc team, which will review and decide on the PR/issue. labels Dec 25, 2025