Since you have the perfect working (clang v20) vs non-working (clang v21) situation, you could try using
go build -x -work to see what .o files are being produced and then llvm-objdump -f your_object_file.o on all of the .o files to see if the types changed? ...and then try to contrast the two: see exactly which file has a "changed" format, if any -- if you found one that changed, you could go deeper into exactly what changed; the semantic equivalent of a binary "diff" but based on llvm-objdump https://llvm.org/docs/CommandGuide/llvm-objdump.html On Monday, September 1, 2025 at 1:26:12 AM UTC+1 Alex wrote: > Well I have been using bleeding edge clang for a couple of years now, this > is the first stable release version to break. > llvm-mingw is even the compiler the builders use so it's the opposite > actually, it would be surprising for clang to not work. > See linked issue for reasons why the move to clang: > https://github.com/golang/go/issues/35006#issuecomment-1122405895 > > On Monday, 1 September 2025 at 2:25:51 am UTC+8 Jason E. Aten wrote: > >> ah, I see you said "using clang20 works as expected", so I guess clang is >> working fine >> on that version... >> >> On Sunday, August 31, 2025 at 7:23:47 PM UTC+1 Jason E. Aten wrote: >> >>> Hi Alex, >>> >>> I haven't worked with Go on Windows in a year, so my knowledge >>> might be out of date... That said, I found CGO very sensitive to >>> the exact C compiler used, and even within GCC, the exact version. >>> Here is the version that I had working at one point in the last couple >>> of years: >>> >>> mingw-w64/x86_64-8.1.0-posix-seh-rt_v6-rev0 (somewhere on sourceforge I >>> think). >>> >>> Mind you, I'm not saying you cannot get Clang to work. I'm just >>> suggesting >>> that if you start with a positive control (that does let you build), >>> then you >>> can confidently try other compilers knowing that everything else is held >>> the same. >>> >>> Or you might have gotten what you need with the mingw-w64 gcc, and that's >>> good enough. >>> >>> Let me know if you are able to make Clang work--it would be an >>> interesting data point. >>> >>> Best, >>> Jason >>> >>> On Sunday, August 31, 2025 at 12:56:13 PM UTC+1 Alex wrote: >>> >>>> I am using the go compiler, this is about using cgo together with the >>>> go compiler. >>>> And this was with the 1.24 and 1.25 toolchains >>>> >>>> On Sunday, 31 August 2025 at 7:51:08 pm UTC+8 Michael Oguidan wrote: >>>> >>>>> Hi Alex, which version of Go are you using, and why don't use the >>>>> actual Go compiler which is written in Go. >>>>> >>>>> On Sunday, August 31, 2025 at 8:15:39 AM UTC Alex wrote: >>>>> >>>>>> Been trying to use go with clang21 on windows but compiling any cgo >>>>>> app results in "cannot parse *.o as ELF, Mach-O, PE or XCOFF" >>>>>> >>>>>> Tried with go1.24.* and 1.25, using clang20 works as expected. >>>>> >>>>> -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/golang-nuts/bbb76917-57a7-4b96-aed0-6e234e3181a3n%40googlegroups.com.
