Use free regions when determining self type in compare_impl_method

[sapphire-arches]

The ExplicitSelf::determine function expects to be able to compare regions. However, when the compare_self_type error reporting code runs we haven't resolved bound regions yet. Thus we replace them with free regions first. Fixes #48276

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @nikomatsakis (or someone else) soon.

If any changes to this PR are deemed necessary, please add them as extra commits. This ensures that the reviewer can see what has changed since they last reviewed the code. Due to the way GitHub handles out-of-date commits, this should also make it reasonably obvious what issues have or haven't been addressed. Large or tricky changes may require several passes of review and changes.

Please see the contribution instructions for more information.

[pietroalbini]

Thanks for the PR @bobtwinkles, the release team will periodically make sure this PR gets reviewed.

@nikomatsakis, this PR needs your review!

[nikomatsakis]

@bors r+

[bors]

📌 Commit 9882050 has been approved by nikomatsakis

[Manishearth]

I get a failure on this in the rollup

[01:00:19] failures:
[01:00:19] 
[01:00:19] ---- [ui] ui/issue-48276.rs stdout ----
[01:00:19] 	diff of stderr:
[01:00:19] 
[01:00:19] 1	error[E0185]: method `from` has a `&self` declaration in the impl, but not in the trait
[01:00:19] 2	  --> $DIR/issue-48276.rs:21:5
[01:00:19] 3	   |
[01:00:19] -	15 |     fn from(a: A) -> Self;
[01:00:19] +	LL |     fn from(a: A) -> Self;
[01:00:19] 5	   |     ---------------------- trait method declared without `&self`
[01:00:19] 6	...
[01:00:19] -	21 |     fn from(self: &'a Self) -> &'b str {
[01:00:19] +	LL |     fn from(self: &'a Self) -> &'b str {
[01:00:19] 8	   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `&self` used in impl
[01:00:19] 9	
[01:00:19] 10	error[E0185]: method `from` has a `&self` declaration in the impl, but not in the trait
[01:00:19] 
[01:00:19] 11	  --> $DIR/issue-48276.rs:30:5
[01:00:19] 12	   |
[01:00:19] -	30 |     fn from(&self) -> B {
[01:00:19] +	LL |     fn from(&self) -> B {
[01:00:19] 14	   |     ^^^^^^^^^^^^^^^^^^^ `&self` used in impl
[01:00:19] 15	   |
[01:00:19] 16	   = note: `from` from trait: `fn(T) -> Self`
[01:00:19] 
[01:00:19] 18	error[E0185]: method `from` has a `&self` declaration in the impl, but not in the trait
[01:00:19] 19	  --> $DIR/issue-48276.rs:37:5
[01:00:19] 20	   |
[01:00:19] -	37 |     fn from(&self) -> &'static str {
[01:00:19] +	LL |     fn from(&self) -> &'static str {
[01:00:19] 22	   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `&self` used in impl
[01:00:19] 23	   |
[01:00:19] 24	   = note: `from` from trait: `fn(T) -> Self`
[01:00:19] 
[01:00:19] 25	
[01:00:19] 26	error: aborting due to 3 previous errors
[01:00:19] 27	
[01:00:19] +	If you want more information on this error, try using "rustc --explain E0185"
[01:00:19] 28	
[01:00:19] 
[01:00:19] 
[01:00:19] The actual stderr differed from the expected stderr.
[01:00:19] Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/issue-48276.stderr
[01:00:19] To update references, run this command from build directory:
[01:00:19] /checkout/src/test/ui/update-references.sh '/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui' 'issue-48276.rs'
[01:00:19] 
[01:00:19] error: 1 errors occurred comparing output.
[01:00:19] status: exit code: 101
[01:00:19] stdout:
[01:00:19] ------------------------------------------
[01:00:19] 
[01:00:19] ------------------------------------------
[01:00:19] stderr:
[01:00:19] ------------------------------------------
[01:00:19] error[E0185]: method `from` has a `&self` declaration in the impl, but not in the trait
[01:00:19]   --> /checkout/src/test/ui/issue-48276.rs:21:5
[01:00:19]    |
[01:00:19] LL |     fn from(a: A) -> Self;
[01:00:19]    |     ---------------------- trait method declared without `&self`
[01:00:19] ...
[01:00:19] LL |     fn from(self: &'a Self) -> &'b str {
[01:00:19]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `&self` used in impl
[01:00:19] 
[01:00:19] error[E0185]: method `from` has a `&self` declaration in the impl, but not in the trait
[01:00:19]   --> /checkout/src/test/ui/issue-48276.rs:30:5
[01:00:19]    |
[01:00:19] LL |     fn from(&self) -> B {
[01:00:19]    |     ^^^^^^^^^^^^^^^^^^^ `&self` used in impl
[01:00:19]    |
[01:00:19]    = note: `from` from trait: `fn(T) -> Self`
[01:00:19] 
[01:00:19] error[E0185]: method `from` has a `&self` declaration in the impl, but not in the trait
[01:00:19]   --> /checkout/src/test/ui/issue-48276.rs:37:5
[01:00:19]    |
[01:00:19] LL |     fn from(&self) -> &'static str {
[01:00:19]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `&self` used in impl
[01:00:19]    |
[01:00:19]    = note: `from` from trait: `fn(T) -> Self`
[01:00:19] 
[01:00:19] error: aborting due to 3 previous errors
[01:00:19] 
[01:00:19] If you want more information on this error, try using "rustc --explain E0185"
[01:00:19] 
[01:00:19] ------------------------------------------
[01:00:19] 
[01:00:19] thread '[ui] ui/issue-48276.rs' panicked at 'explicit panic', tools/compiletest/src/runtest.rs:2893:9
[01:00:19] note: Run with `RUST_BACKTRACE=1` for a backtrace.
[01:00:19] 
[01:00:19] 
[01:00:19] failures:
[01:00:19]     [ui] ui/issue-48276.rs
[01:00:19] 
[01:00:19] test result: FAILED. 1243 passed; 1 failed; 4 ignored; 0 measured; 0 filtered out
[01:00:19] 
[01:00:19] thread 'main' panicked at 'Some tests failed', tools/compiletest/src/main.rs:476:22
[01:00:19] 

[pietroalbini]

That failure is caused by #48449, which replaces line numbers with LL.

[Manishearth]

@bors r-

re-r+ when this is fixed

[nikomatsakis]

easiest way to fix is to rebase and re-run the UI tests locally

[sapphire-arches]

Yep. I'll try and get to this tonight, and will certainly have it by later tomorrow. I've gotten unexpectedly busy this week.

…

On Thu, Mar 1, 2018, 13:28 Niko Matsakis ***@***.***> wrote: easiest way to fix is to rebase and re-run the UI tests locally — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#48419 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABcc_EDw7wFqKFFaNpf8Y5ys7qog7IZdks5taD3TgaJpZM4SOsQM> .

[sapphire-arches]

Rebased and updated to new stderr format. Should be an easy review =)

[nikomatsakis]

@bors r+

[bors]

📌 Commit c0d41fb has been approved by nikomatsakis

[bors]

⌛ Testing commit c0d41fb with merge 9a46d8adb83f73c72a2e876764993c4746957199...

[bors]

💔 Test failed - status-appveyor

[pietroalbini]

Appveyor timeout on dist x86_64.

@bors retry

[kennytm]

Note: Timeout is due to being stuck when cloning rust-by-examples. This happened 1 month before in #47761 (comment).

[bors]

⌛ Testing commit c0d41fb with merge 0bae326...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: nikomatsakis
Pushing 0bae326 to master...