| The files here use the LLVM FileCheck framework, documented at |
| <https://llvm.org/docs/CommandGuide/FileCheck.html>. |
| |
| One extension worth noting is the use of revisions as custom prefixes for |
| FileCheck. If your codegen test has different behavior based on the chosen |
| target or different compiler flags that you want to exercise, you can use a |
| revisions annotation, like so: |
| |
| ```rust |
| // revisions: aaa bbb |
| // [bbb] compile-flags: --flags-for-bbb |
| ``` |
| |
| After specifying those variations, you can write different expected, or |
| explicitly *unexpected* output by using `<prefix>-SAME:` and `<prefix>-NOT:`, |
| like so: |
| |
| ```rust |
| // CHECK: expected code |
| // aaa-SAME: emitted-only-for-aaa |
| // aaa-NOT: emitted-only-for-bbb |
| // bbb-NOT: emitted-only-for-aaa |
| // bbb-SAME: emitted-only-for-bbb |
| ``` |
