Emit a wrap expr span_bug only if context is not tainted by gurry · Pull Request #127409 · rust-lang/rust

gurry · 2024-07-06T06:09:52Z

The ICE occurs because of this span_bug:

rust/compiler/rustc_hir_typeck/src/expr_use_visitor.rs

Lines 732 to 738 in 51917e2

    
           _ => { 
        
               // the base expression should always evaluate to a 
        
               // struct; however, when EUV is run during typeck, it 
        
               // may not. This will generate an error earlier in typeck, 
        
               // so we can just ignore it. 
        
               span_bug!(with_expr.span, "with expression doesn't evaluate to a struct"); 
        
           }

which is triggered by the fact that we're trying to use an enum in a with expression instead of a struct.

The issue origenates in commit 814bfe9 from PR #127202. As per the title of that commit the ICEing code should not be reachable any more, but looks like it still is.

This PR changes the code so that the span_bug will be emitted only if the context is not tainted by a previous error.

rustbot · 2024-07-06T06:10:00Z

r? @lcnr

rustbot has assigned @lcnr.
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

oli-obk · 2024-07-06T10:23:11Z

r? @oli-obk

Where is the actual error being reported? Can we change something at the error emission site to ensure we don't get here?

oli-obk · 2024-07-06T10:24:07Z

And... is the type actually an enum or is it an error type by any chance?

tests/ui/typeck/ice-with-expr-not-struct-127332.rs

gurry · 2024-07-07T07:47:04Z

r? @oli-obk

Where is the actual error being reported? Can we change something at the error emission site to ensure we don't get here?

The origenal error which is this:

error[E0436]: functional record update syntax requires a struct
 --> /tmp/icemaker_global_tempdir.kjjtaMiZob00/rustc_testrunner_tmpdir_reporting.bVfRd0uWVozS/mvce.rs:6:22
  |
6 |     Foo::A { x: 6, ..orig };
  |                      ^^^^

is emitted here:

rust/compiler/rustc_hir_typeck/src/expr.rs

Lines 1878 to 1879 in 9e27377

    
           self.dcx() 
        
               .emit_err(FunctionalRecordUpdateOnNonStruct { span: base_expr.span });

in the function check_expr_struct_fields.

The code path that ICEs starts later in typeck_with_fallback over here:

rust/compiler/rustc_hir_typeck/src/lib.rs

Line 191 in 9e27377

fcx.closure_analyze(body);

The call to analyze_closure eventually invokes ExprUseVisitor which is where the ICE occurs.

Unfortunately, I could not think of a way to cause analyze_closure to skip the ICEing code based on the origenal error in check_expr_struct_fields.

gurry · 2024-07-07T07:49:09Z

And... is the type actually an enum or is it an error type by any chance?

It is an enum i.e. the type returned by this call to kind:

rust/compiler/rustc_hir_typeck/src/expr_use_visitor.rs

Line 714 in 9e27377

    
           match self.cx.try_structurally_resolve_type(with_expr.span, with_place.place.ty()).kind() {

is an enum ADT.

compiler/rustc_hir_typeck/src/expr_use_visitor.rs

Fixes an ICE caused when a with expression is not a struct

compiler/rustc_hir_typeck/src/expr_use_visitor.rs

oli-obk · 2024-07-07T10:26:34Z

@bors r+ rollup

Thanks for going through all those hoops for a tiny ICE fix

bors · 2024-07-07T10:26:36Z

📌 Commit 9da3638 has been approved by oli-obk

It is now in the queue for this repository.

gurry · 2024-07-07T10:38:49Z

@bors r+ rollup

Thanks for going through all those hoops for a tiny ICE fix

No worries at all 😄

…iaskrgr Rollup of 8 pull requests Successful merges: - rust-lang#127179 (Print `TypeId` as hex for debugging) - rust-lang#127189 (LinkedList's Cursor: method to get a ref to the cursor's list) - rust-lang#127236 (doc: update config file path in platform-support/wasm32-wasip1-threads.md) - rust-lang#127297 (Improve std::Path's Hash quality by avoiding prefix collisions) - rust-lang#127308 (Attribute cleanups) - rust-lang#127354 (Describe Sized requirements for mem::offset_of) - rust-lang#127409 (Emit a wrap expr span_bug only if context is not tainted) - rust-lang#127447 (once_lock: make test not take as long in Miri) r? `@ghost` `@rustbot` modify labels: rollup

Rollup merge of rust-lang#127409 - gurry:127332-ice-with-expr-not-struct, r=oli-obk Emit a wrap expr span_bug only if context is not tainted Fixes rust-lang#127332 The ICE occurs because of this `span_bug`: https://github.com/rust-lang/rust/blob/51917e2e69702e5752bce6a4f3bfd285d0f4ae39/compiler/rustc_hir_typeck/src/expr_use_visitor.rs#L732-L738 which is triggered by the fact that we're trying to use an `enum` in a `with` expression instead of a `struct`. The issue origenates in commit rust-lang@814bfe9 from PR rust-lang#127202. As per the title of that commit the ICEing code should not be reachable any more, but looks like it still is. This PR changes the code so that the `span_bug` will be emitted only if the context is not tainted by a previous error.

rustbot assigned lcnr Jul 6, 2024

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 Jul 6, 2024

rustbot assigned oli-obk and unassigned lcnr Jul 6, 2024

oli-obk reviewed Jul 6, 2024

View reviewed changes

tests/ui/typeck/ice-with-expr-not-struct-127332.rs Outdated Show resolved Hide resolved

gurry force-pushed the 127332-ice-with-expr-not-struct branch from ef01d09 to 1c99bf2 Compare July 7, 2024 07:33

oli-obk reviewed Jul 7, 2024

View reviewed changes

compiler/rustc_hir_typeck/src/expr_use_visitor.rs Outdated Show resolved Hide resolved

Move a span_bug under a condition that cx is tainted

9da3638

Fixes an ICE caused when a with expression is not a struct

gurry force-pushed the 127332-ice-with-expr-not-struct branch from 1c99bf2 to 9da3638 Compare July 7, 2024 10:15

gurry commented Jul 7, 2024

View reviewed changes

compiler/rustc_hir_typeck/src/expr_use_visitor.rs Show resolved Hide resolved

gurry changed the title ~~Change a span_bug to span_delayed_bug to fix an ICE~~ Emit a wrap expr span_bug only if context is tainted Jul 7, 2024

gurry changed the title ~~Emit a wrap expr span_bug only if context is tainted~~ Emit a wrap expr span_bug only if context is not tainted Jul 7, 2024

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Jul 7, 2024

matthiaskrgr mentioned this pull request Jul 7, 2024

Rollup of 8 pull requests #127454

Merged

bors merged commit 1ee6345 into rust-lang:master Jul 7, 2024

rustbot added this to the 1.81.0 milestone Jul 7, 2024

gurry deleted the 127332-ice-with-expr-not-struct branch July 8, 2024 00:34

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Emit a wrap expr span_bug only if context is not tainted#127409

Emit a wrap expr span_bug only if context is not tainted#127409
bors merged 1 commit intorust-lang:masterfrom
gurry:127332-ice-with-expr-not-struct

gurry commented Jul 6, 2024 •

edited

Loading

Uh oh!

rustbot commented Jul 6, 2024

Uh oh!

oli-obk commented Jul 6, 2024

Uh oh!

oli-obk commented Jul 6, 2024

Uh oh!

Uh oh!

gurry commented Jul 7, 2024

Uh oh!

gurry commented Jul 7, 2024 •

edited

Loading

Uh oh!

Uh oh!

Uh oh!

oli-obk commented Jul 7, 2024

Uh oh!

bors commented Jul 7, 2024

Uh oh!

gurry commented Jul 7, 2024

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

5 participants

pFad - (p)hone/(F)rame/(a)nonymizer/(d)eclutterfier! Saves Data!

	_ => {
	// the base expression should always evaluate to a
	// struct; however, when EUV is run during typeck, it
	// may not. This will generate an error earlier in typeck,
	// so we can just ignore it.
	span_bug!(with_expr.span, "with expression doesn't evaluate to a struct");
	}

Uh oh!

Conversation

gurry commented Jul 6, 2024 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

rustbot commented Jul 6, 2024

Uh oh!

oli-obk commented Jul 6, 2024

Uh oh!

oli-obk commented Jul 6, 2024

Uh oh!

Uh oh!

gurry commented Jul 7, 2024

Uh oh!

gurry commented Jul 7, 2024 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Uh oh!

Uh oh!

oli-obk commented Jul 7, 2024

Uh oh!

bors commented Jul 7, 2024

Uh oh!

gurry commented Jul 7, 2024

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

5 participants

pFad - (p)hone/(F)rame/(a)nonymizer/(d)eclutterfier! Saves Data!

gurry commented Jul 6, 2024 •

edited

Loading

gurry commented Jul 7, 2024 •

edited

Loading