Add span label to E0384 for MIR borrowck #44806

KiChjang · 2017-09-24T11:02:46Z

Corresponds to report_illegal_reassignment.

Part of #44596.

rust-highfive · 2017-09-24T11:02:57Z

r? @nikomatsakis

(rust_highfive has picked a reviewer for you, use r? to override)

KiChjang · 2017-09-25T16:19:11Z

r? @pnkfelix

pnkfelix · 2017-09-25T20:06:55Z

@KiChjang can you look into porting the test, in the same manner as discussed at #44811 (comment)

pnkfelix · 2017-09-25T20:10:48Z

src/librustc_mir/borrow_check.rs

+                            continue;
+                        }
+                        Lvalue::Local(local) => {
+                            let assigned_span = self.mir.local_decls[local].source_info.span;


Does the source info for the declaration always correspond to the assigned span when reported by AST borrowck?

In particular, I'm thinking of cases like:

let declare_without_init: i32; match result { Ok(_) => declare_without_init = 1, Err(_) => declare_without_init = 2, } ... declare_without_init = 3;

where the AST-borrowck today, for better or worse, tags the assignment in the first match arm as the "first assignment"

I don't actually know, I've only looked around the source code and used my own deduction skills to do what makes sense in order to retrieve a span. Perhaps @nikomatsakis may know more about this?

I just compiled the example you gave with my patch -- it actually does the wrongest thing, which is displaying the span of let declare_without_init: i32;. It would seem like mir.local_decls would not provide the location in which a variable is assigned.

KiChjang · 2017-09-26T10:14:38Z

I believe this can be re-reviewed. r? @pnkfelix

arielb1 · 2017-09-26T18:02:44Z

I think your revision tags are not working:


[00:51:10] ---- [compile-fail] compile-fail/borrowck/borrowck-match-binding-is-assignment.rs stdout ----
[00:51:10] 	
[00:51:10] error in revision `mir`: /checkout/src/test/compile-fail/borrowck/borrowck-match-binding-is-assignment.rs:29: unexpected "error": '29:13: 29:19: re-assignment of immutable variable `x` [E0384]'
[00:51:10] 
[00:51:10] error in revision `mir`: /checkout/src/test/compile-fail/borrowck/borrowck-match-binding-is-assignment.rs:37: unexpected "error": '37:13: 37:19: re-assignment of immutable variable `x` [E0384]'
[00:51:10] 
[00:51:10] error in revision `mir`: /checkout/src/test/compile-fail/borrowck/borrowck-match-binding-is-assignment.rs:45: unexpected "error": '45:13: 45:19: re-assignment of immutable variable `x` [E0384]'
[00:51:10] 
[00:51:10] error in revision `mir`: /checkout/src/test/compile-fail/borrowck/borrowck-match-binding-is-assignment.rs:53: unexpected "error": '53:13: 53:19: re-assignment of immutable variable `x` [E0384]'
[00:51:10] 
[00:51:10] error in revision `mir`: /checkout/src/test/compile-fail/borrowck/borrowck-match-binding-is-assignment.rs:61: unexpected "error": '61:13: 61:19: re-assignment of immutable variable `x` [E0384]'
[00:51:10] 
[00:51:10] error in revision `mir`: /checkout/src/test/compile-fail/borrowck/borrowck-match-binding-is-assignment.rs:29: expected error not found: re-assignment of immutable variable `x` (Mir)
[00:51:10] 
[00:51:10] error in revision `mir`: /checkout/src/test/compile-fail/borrowck/borrowck-match-binding-is-assignment.rs:29: expected error not found: re-assignment of immutable variable `x` (Ast)
[00:51:10] 
[00:51:10] error in revision `mir`: /checkout/src/test/compile-fail/borrowck/borrowck-match-binding-is-assignment.rs:37: expected error not found: re-assignment of immutable variable `x` (Mir)
[00:51:10] 
[00:51:10] error in revision `mir`: /checkout/src/test/compile-fail/borrowck/borrowck-match-binding-is-assignment.rs:37: expected error not found: re-assignment of immutable variable `x` (Ast)
[00:51:10] 
[00:51:10] error in revision `mir`: /checkout/src/test/compile-fail/borrowck/borrowck-match-binding-is-assignment.rs:45: expected error not found: re-assignment of immutable variable `x` (Mir)
[00:51:10] 
[00:51:10] error in revision `mir`: /checkout/src/test/compile-fail/borrowck/borrowck-match-binding-is-assignment.rs:45: expected error not found: re-assignment of immutable variable `x` (Ast)
[00:51:10] 
[00:51:10] error in revision `mir`: /checkout/src/test/compile-fail/borrowck/borrowck-match-binding-is-assignment.rs:53: expected error not found: re-assignment of immutable variable `x` (Mir)
[00:51:10] 
[00:51:10] error in revision `mir`: /checkout/src/test/compile-fail/borrowck/borrowck-match-binding-is-assignment.rs:53: expected error not found: re-assignment of immutable variable `x` (Ast)
[00:51:10] 
[00:51:10] error in revision `mir`: /checkout/src/test/compile-fail/borrowck/borrowck-match-binding-is-assignment.rs:61: expected error not found: re-assignment of immutable variable `x` (Mir)
[00:51:10] 
[00:51:10] error in revision `mir`: /checkout/src/test/compile-fail/borrowck/borrowck-match-binding-is-assignment.rs:61: expected error not found: re-assignment of immutable variable `x` (Ast)
[00:51:10]

arielb1 · 2017-09-26T18:04:19Z

src/test/compile-fail/borrowck/borrowck-match-binding-is-assignment.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.

+// revisions: ast mir
+//[mir]compfile-flags: -Zemit-end-regions -Zborrowck-mir


I think you want to use [mir]compile-flags (not compfile) here. I think that's why you're getting the travis error.

Ack, this is so embarrassing!

arielb1 · 2017-09-26T20:37:33Z

[00:14:00] error[E0308]: mismatched types
[00:14:00]    --> /checkout/src/librustc_mir/borrow_check.rs:594:75
[00:14:00]     |
[00:14:00] 594 |                 self.report_illegal_reassignment(context, (lvalue, span), assignment_span);
[00:14:00]     |                                                                           ^^^^^^^^^^^^^^^ expected struct `syntax_pos::Span`, found reference
[00:14:00]     |
[00:14:00]     = note: expected type `syntax_pos::Span`
[00:14:00]                found type `&rustc::mir::Statement<'_>`

pnkfelix · 2017-09-27T13:28:47Z

@bors r+

bors · 2017-09-27T13:28:48Z

📌 Commit 6d4989b has been approved by pnkfelix

bors · 2017-09-28T12:40:18Z

⌛ Testing commit 6d4989b with merge d887369...

Add span label to E0384 for MIR borrowck Corresponds to `report_illegal_reassignment`. Part of #44596.

bors · 2017-09-28T16:19:52Z

☀️ Test successful - status-appveyor, status-travis
Approved by: pnkfelix
Pushing d887369 to master...

rust-highfive assigned nikomatsakis Sep 24, 2017

carols10cents added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Sep 25, 2017

rust-highfive assigned pnkfelix and unassigned nikomatsakis Sep 25, 2017

pnkfelix reviewed Sep 25, 2017

View reviewed changes

KiChjang force-pushed the mir-err-notes-2 branch 4 times, most recently from 58c5692 to 3bfe4c0 Compare September 26, 2017 09:55

arielb1 reviewed Sep 26, 2017

View reviewed changes

KiChjang force-pushed the mir-err-notes-2 branch 2 times, most recently from 9fcfad9 to afa52ca Compare September 26, 2017 18:34

KiChjang force-pushed the mir-err-notes-2 branch 2 times, most recently from 6354d75 to c8ae9f4 Compare September 26, 2017 21:27

Add span label to E0384 for MIR borrowck

6d4989b

KiChjang force-pushed the mir-err-notes-2 branch from c8ae9f4 to 6d4989b Compare September 27, 2017 05:21

bors added a commit that referenced this pull request Sep 28, 2017

Auto merge of #44806 - KiChjang:mir-err-notes-2, r=pnkfelix

d887369

Add span label to E0384 for MIR borrowck Corresponds to `report_illegal_reassignment`. Part of #44596.

bors merged commit 6d4989b into rust-lang:master Sep 28, 2017

KiChjang deleted the mir-err-notes-2 branch September 28, 2017 18:14

pnkfelix mentioned this pull request Oct 11, 2017

MIR-borrowck: ICE during diagnostic search for assignment (unwrap of None) #45199

Closed

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Add span label to E0384 for MIR borrowck #44806

Add span label to E0384 for MIR borrowck #44806

KiChjang commented Sep 24, 2017

rust-highfive commented Sep 24, 2017

KiChjang commented Sep 25, 2017

pnkfelix commented Sep 25, 2017

pnkfelix Sep 25, 2017

KiChjang Sep 25, 2017 •

edited

Loading

KiChjang Sep 26, 2017 •

edited

Loading

KiChjang commented Sep 26, 2017

arielb1 commented Sep 26, 2017

arielb1 Sep 26, 2017 •

edited

Loading

KiChjang Sep 26, 2017

arielb1 commented Sep 26, 2017

pnkfelix commented Sep 27, 2017

bors commented Sep 27, 2017

bors commented Sep 28, 2017

bors commented Sep 28, 2017

Add span label to E0384 for MIR borrowck #44806

Add span label to E0384 for MIR borrowck #44806

Conversation

KiChjang commented Sep 24, 2017

rust-highfive commented Sep 24, 2017

KiChjang commented Sep 25, 2017

pnkfelix commented Sep 25, 2017

pnkfelix Sep 25, 2017

Choose a reason for hiding this comment

KiChjang Sep 25, 2017 • edited Loading

Choose a reason for hiding this comment

KiChjang Sep 26, 2017 • edited Loading

Choose a reason for hiding this comment

KiChjang commented Sep 26, 2017

arielb1 commented Sep 26, 2017

arielb1 Sep 26, 2017 • edited Loading

Choose a reason for hiding this comment

KiChjang Sep 26, 2017

Choose a reason for hiding this comment

arielb1 commented Sep 26, 2017

pnkfelix commented Sep 27, 2017

bors commented Sep 27, 2017

bors commented Sep 28, 2017

bors commented Sep 28, 2017

KiChjang Sep 25, 2017 •

edited

Loading

KiChjang Sep 26, 2017 •

edited

Loading

arielb1 Sep 26, 2017 •

edited

Loading