[CIR][CIRGen][NFC] Handle PragmaComment in emitTopLevelDecl

[el-ev]

• Part of Support for Decl::PragmaComment #70

This is not very useful now, as both branches of interest are NYI. I will try to implement the real features in subsequent patches.

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[el-ev]

@bcardosolopes I've done some work on ELFDependentLibraries (el-ev@a989cc2). I added an attribute for CIR, but I'm not seeing a corresponding attribute for LLVM-dialect MLIR. Is this the case where some upstream changes are required first?

[bcardosolopes]

Thanks for working on this, awesome!

Is this the case where some upstream changes are required first?

I see, https://llvm.org/docs/LangRef.html#dependent-libs-named-metadata is indeed not available yet.

So you'll need to add support in LLVM dialect to lower it. I'm fine if you add without LLVM support for now and file an issue to tackle lowering later (because we don't yet have the feature available). I've been making lots of similar changes to LLVM dialect upstream, you can look to them as examples if you'd like to send a PR to upstream MLIR (I can help review too).

[bcardosolopes]

You either need to add a testcase or convey that this PR is a NFC change. The testcase would need to exercise PCK_Compiler, PCK_ExeStr and PCK_User because they are not asserting right now, so classify as a introduced feature.

[bcardosolopes]

We don't change files outside CIR dir without a good reason, formatting is specially bad for rebasing, so you need to remove the changes to this file.

[el-ev]

Pragma comments other than PCK_Lib are dropped in the parser, so this is indeed an NFC change.

https://github.com/llvm/clangir/blob/0fd1437f1c7e901273fb19f1db27ae32c952a0b8/clang/lib/Parse/ParsePragma.cpp#L3231C1-L3235C4