Add support for SHA256 source file checksums in debug info

[arlosi]

Summary

LLVM currently supports CSK_MD5 and CSK_SHA1 source file checksums in debug info. This change adds support for CSK_SHA256 checksums.

The SHA256 checksums are supported by the CodeView debug format.

[aprantl]

Sounds reasonable. One inline question about the test.

llvm/test/Bitcode/upgrade-dbg-checksum.ll

13 ↗

(On Diff #248857)

I would expect a round-trip (as | dis | as |dis) test rather than an upgrade test when adding an extra enumerator. What am I missing?

[arlosi]

Change the test from editing an upgrade test to a new round trip test.

[aprantl]

llvm/test/Assembler/dbg-checksum.ll

1

Please move this to the /Assembler directory, rename it to dbg-checksum.ll, and make the RUN line:
RUN: llvm-as < %s | llvm-dis | llvm-as | llvm-dis FileCheck %s

[arlosi]

Renamed test to appropriate location; modified test to test to disassemble and reassemble again.

[arlosi]

I do not have commit access. Could someone land this for me?

[arlosi]

The previous update contained only the requested changes commit, losing the rest of the change.
Hopefully I've correctly used arc to create the diff this time.

[arlosi]

Fix clang-tidy errors.

[rnk]

In D75785#1913551, @arlosi wrote:

I do not have commit access. Could someone land this for me?

Sure, thanks for the patch!

llvm/test/Assembler/dbg-checksum.ll

 ; Test that DIFile(checksumkind, checksum) can round-trip through bitcode.
 ;
-; RUN: llvm-as < %s | llvm-dis | FileCheck %s
+; RUN: llvm-as < %s | llvm-dis | llvm-as | llvm-dis | FileCheck %s
 
 !llvm.dbg.cu = !{!1, !2, !3, !4}
 !llvm.module.flags = !{!9}
 
 !1 = distinct !DICompileUnit(language: DW_LANG_C99, file: !5, isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 !2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !6, isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 !3 = distinct !DICompileUnit(language: DW_LANG_C99, file: !7, isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 !4 = distinct !DICompileUnit(language: DW_LANG_C99, file: !8, isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)