bdf9ed497a
Fix codegen test suite for bare-metal-like targets
For Ferrocene I needed to run the test suite for custom target with no unwinding and static relocation. Running the tests uncovered ~20 failures due to the test suite not accounting for these options. This PR fixes them by:
* Fixing `CHECK`s to account for functions having extra LLVM IR attributes (in this case `nounwind`).
* Fixing `CHECK`s to account for the `dso_local` LLVM IR modifier, which is [added to every item when relocation is static](f3d597b31c/compiler/rustc_codegen_llvm/src/mono_item.rs (L139-L142)).
* Fixing `CHECK`s to account for missing `uwtables` attributes.
* Added the `needs-unwind` attributes for tests that are designed to check unwinding.
There is no part of Rust CI that checks this unfortunately, and testing whether the PR works locally is kinda hard because you need a target with std enabled but no unwinding and static relocations. Still, this works in my local testing, and if future PRs accidentally break this Ferrocene will take care of sending followup PRs.
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:
// 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:
// 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