Handle properly when there is no crate attrs

[chenyukang]

Fixes #107822

r? @oli-obk

[oli-obk]

I think we should stop compilation and report an error instead of silently continueing. The user asked for something to get printed and we just don't print anything, that seems suboptimal.

You can add a test for this in tests/run-make. The valid-print-requests test looks very similar to this, so you can copy it to a new test and adjust it to test this situation.

[chenyukang]

The current fix return Compilation::Continue actually will stop compilation and report an an error, because of this line:

rust/compiler/rustc_driver_impl/src/lib.rs

Line 263 in 8996ea9

early_error(sopts.error_format, "no input filename given")

the output is:

gh-chenyukang@dev-desktop-us-2:~/rust$ rustc +dev --print crate-name
error: no input filename given

The naming and code path seems easy to misinterpret, I will have a cleanup and add test.

[chenyukang]

For command line:

rustc +dev -o /tmp/out

error: no input filename given

it's returned by this line, seems not relevant code logic but just works by expection 😂

rust/compiler/rustc_driver_impl/src/lib.rs

Line 599 in 8996ea9

return Compilation::Continue;

then

rust/compiler/rustc_driver_impl/src/lib.rs

Line 263 in 8996ea9

early_error(sopts.error_format, "no input filename given")

[oli-obk]

@bors r+ rollup

Yea, that error is sufficient imo, thanks

[bors]

📌 Commit 2573898 has been approved by oli-obk

It is now in the queue for this repository.