Fix linker error by resolving regions for main return type obligations#151377

xonx4l · 2026-01-19T18:02:13Z

This PR fix linker error by resolving regions for main return type obligations as discussed in #148421

Added a final check . Now the compiler double-checks the lifetimes for main right away. If they don't work it stops and gives the user a clean compiler error instead of a linker crash.

Fixes #148421.

rustbot · 2026-01-19T18:02:18Z

r? @fee1-dead

rustbot has assigned @fee1-dead.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

xonx4l · 2026-01-19T18:10:53Z

compiler/rustc_hir_analysis/src/check/entry.rs

+        }
+
+        let region_errors =
+            infcx.resolve_regions(main_diagnostics_def_id, param_env, tcx.mk_type_list(&[]));


One thing I'm slightly unsure about is the diagnostic span main_diagnostics_def_id as this points to the function as a whole.

This DefId is the context in which we're emitting the errors, so it should be the DefId of the whole body. This is correct. Please use ty::List::empty() instead of mk_type_list

Also, can you change this function to return Result<(), ErrorGuaranteed> and instead of using error = true just return Err(guar).

We shouldn't emit region errors if there are fulfillment errors

@lcnr sorry I was a bit busy . I have made the the changes you asked for . Thanks!

compiler/rustc_hir_analysis/src/check/entry.rs

rustbot · 2026-01-22T17:32:10Z

Reminder, once the PR becomes ready for a review, use @rustbot ready.

xonx4l · 2026-02-07T17:14:21Z

@rustbot ready

fee1-dead · 2026-02-17T00:52:24Z

Overall looks correct, but for signoff:

r? lcnr

xonx4l · 2026-02-23T14:51:49Z

@rustbot ready

lcnr · 2026-03-02T09:21:57Z

compiler/rustc_hir_analysis/src/check/entry.rs


    if error {
-        return;
+        return Ok(());


?

we should return Err(ErrorGuaranteed) here

I am sorry I got a bit busy and it just slipped out of my focus . Updated to enforce Err(ErrorGuaranteed). Thanks !

lcnr · 2026-03-02T09:22:10Z

compiler/rustc_hir_analysis/src/check/entry.rs

    .is_err()
    {
-        return;
+        return Ok(());


rustbot · 2026-03-24T04:57:56Z

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

lcnr · 2026-03-24T10:30:48Z

compiler/rustc_hir_analysis/src/check/wfcheck.rs

            .and(items.par_opaques(|item| tcx.ensure_result().check_well_formed(item)));
-    super::entry::check_for_entry_fn(tcx);
+
+    super::entry::check_for_entry_fn(tcx)?;


why not part of the and 🤔

I kept it separate to make sure error is propagated.

lcnr · 2026-03-24T10:31:16Z

tests/ui/typeck/main-termination-lifetime-issue-148421.rs

@@ -0,0 +1,15 @@
+// check-fail


check-fail isn't necessary.

Can you add a comment for what this is testing (and link to the issue in the file (and not necessarily in the test name))

Okay will add.

lcnr · 2026-04-08T07:06:16Z

@bors r+ rollup

rust-bors · 2026-04-08T07:06:21Z

📌 Commit a39e746 has been approved by lcnr

It is now in the queue for this repository.

lcnr · 2026-04-08T07:07:17Z

@bors squash="Fix linker error by resolving regions for main return type obligations"

rust-bors · 2026-04-08T07:07:22Z

Unknown command "squash". Run @bors help to see available commands.

lcnr · 2026-04-08T07:07:28Z

@bors help

rust-bors · 2026-04-08T07:07:39Z

You can use the following commands:

PR management

r+ [p=<priority>] [rollup=<never|iffy|maybe|always>]: Approve this PR on your behalf
- Optionally, you can specify the <priority> of the PR and if it is eligible for rollups (<rollup>).
r=<user> [p=<priority>] [rollup=<never|iffy|maybe|always>]: Approve this PR on behalf of <user>
- Optionally, you can specify the <priority> of the PR and if it is eligible for rollups (<rollup>).
- You can pass a comma-separated list of GitHub usernames.
r-: Unapprove this PR
p=<priority> or priority=<priority>: Set the priority of this PR
rollup=<never|iffy|maybe|always>: Set the rollup status of the PR
rollup: Short for rollup=always
rollup-: Short for rollup=maybe
delegate=<try|review>: Delegate permissions for running try builds or approving to the PR author
- try allows the PR author to start try builds.
- review allows the PR author to both start try builds and approve the PR.
delegate | delegate+: Delegate approval permissions to the PR author
- Shortcut for delegate=review
delegate-: Remove any previously granted permission delegation
try [parent=<parent>] [job|jobs=<jobs>]: Start a try build.
- Optionally, you can specify a <parent> SHA with which will the PR be merged. You can specify parent=last to use the same parent SHA as the previous try build.
- Optionally, you can select a comma-separated list of CI <jobs> to run in the try build.
try cancel: Cancel a running try build on the current PR.
retry: Clear a failed auto build status from an approved PR. This will cause the merge queue to eventually attempt to merge the PR again.
cancel | yield: Cancel a running auto build on the current PR.
squash [msg|message=<commit-message>]: Squash the commits of a PR into a single commit.
- Optionally, you can specify a <commit-message> for the created commit. If not specified, the commit messages of all squashed commits will be combined.
info: Get information about the current PR

Repository management

treeclosed=<priority>: Close the tree for PRs with priority less than <priority>
treeclosed- or treeopen: Open the repository tree for merging

Meta commands

ping: Check if the bot is alive
help: Print this help message

lcnr · 2026-04-08T07:08:14Z

@bors squash

rust-bors · 2026-04-08T07:08:27Z

🚧 Squashing... this can take a few minutes.

rust-bors · 2026-04-08T07:09:28Z

❗ Failed to push the squashed commit to xonx4l/rust:main_termination: Push timeouted

lcnr · 2026-04-08T07:11:46Z

@bors r-

@bors delegate+

rust-bors · 2026-04-08T07:11:51Z

✌️ @xonx4l, you can now approve this pull request!

If @lcnr told you to "r=me" after making some further change, then please make that change and post @bors r=lcnr.

lcnr · 2026-04-08T07:11:56Z

can you please squash your commits, then r=me

xonx4l · 2026-04-09T14:41:21Z

@bors r=lcnr

rust-bors · 2026-04-09T14:41:25Z

📌 Commit dbc08cf has been approved by lcnr

It is now in the queue for this repository.

Fix linker error by resolving regions for main return type obligations This PR fix linker error by resolving regions for main return type obligations as discussed in rust-lang#148421 Added a final check . Now the compiler double-checks the lifetimes for main right away. If they don't work it stops and gives the user a clean compiler error instead of a linker crash. Fixes rust-lang#148421.

rustbot assigned fee1-dead Jan 19, 2026

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. labels Jan 19, 2026

xonx4l commented Jan 19, 2026

View reviewed changes