Matthias Krüger df3712ce21
Rollup merge of #121193 - compiler-errors:coherence-fulfillment, r=lcnr
Use fulfillment in next trait solver coherence

Use fulfillment in the new trait solver's `impl_intersection_has_impossible_obligation` routine. This means that inference that falls out of processing other obligations can influence whether we can determine if an obligation is impossible to satisfy. See the committed test.

This should be completely sound, since evaluation and fulfillment both respect intercrate mode equally.

We run the risk of breaking coherence later if we were to change the rules of fulfillment and/or inference during coherence, but this is a problem which affects evaluation, as nested obligations from a trait goal are processed together and can influence each other in the same way.

r? lcnr
cc #114862

Also changed obligationctxt -> fulfillmentctxt because it feels kind of redundant to use an ocx here. I don't really care enough and can change it back if it really matters much.
2024-02-17 18:47:42 +01:00
..
2024-02-17 10:44:46 +05:30

UI Tests

This folder contains rustc's UI tests.

Test Directives (Headers)

Typically, a UI test will have some test directives / headers which are special comments that tell compiletest how to build and intepret a test.

As part of an on-going effort to rewrite compiletest (see https://github.com/rust-lang/compiler-team/issues/536), a major change proposal to change legacy compiletest-style headers // <directive> to ui_test-style headers //@ <directive> was accepted (see https://github.com/rust-lang/compiler-team/issues/512.

An example directive is ignore-test. In legacy compiletest style, the header would be written as

// ignore-test

but in ui_test style, the header would be written as

//@ ignore-test

compiletest is changed to accept only //@ directives for UI tests (currently), and will reject and report an error if it encounters any comments // <content> that may be parsed as an legacy compiletest-style test header. To fix this, you should migrate to the ui_test-style header //@ <content>.