Reject extra fields in MGCA struct const arguments#157886
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HIR ty lowering was modified cc @fmease |
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| for init in inits { | ||
| if !variant_def.fields.iter().any(|field_def| field_def.name == init.field.name) { | ||
| let err = tcx.dcx().struct_span_err( | ||
| init.field.span, | ||
| format!("struct expression has no field named `{}`", init.field), | ||
| ); | ||
| return ty::Const::new_error(tcx, err.emit()); | ||
| } | ||
| } | ||
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Currently, lower_const_arg_struct handled missing and duplicate initializers, but it did not check for extra fields. This checkd for fields that do not exist on the target variant.
| if !variant_def.fields.iter().any(|field_def| field_def.name == init.field.name) { | ||
| let err = tcx.dcx().struct_span_err( | ||
| init.field.span, | ||
| format!("struct expression has no field named `{}`", init.field), |
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This message seems a little off... the expression does have the field; it's the struct definition that does not. We should match the wording for the normal (non-MGCA) message: "struct S has no field named x".
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hmm.. Now I think of it, should have not written expressions. I will update it, Thanks.
| let err = tcx.dcx().struct_span_err( | ||
| init.field.span, | ||
| format!("struct expression has no field named `{}`", init.field), | ||
| format!("struct {} has no field named `{}`", variant_def.name, init.field), |
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This should use backticks around the struct name, like the non-MGCA error message I showed before.
Also, please add a test with an enum struct variant (like enum E { S {} }) so we can make sure that message looks good too. You will probably have to change the message for enums, so we that can match the non-MGCA error message for that too: https://play.rust-lang.org/?version=stable&mode=debug&edition=2024&gist=ce981a7c73a8b0d5322b9bd9f9bd628d
Otherwise, this looks good!
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Ah, my bad, I didn't see the backticks.
I don't think we need the enum case, since it doesn't ICE and already provides a clear error message for enum. Apparently, this ICE's only for struct variants.
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closes: #154538
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