Why all the conversions? Why not just pass the C pointer from one package to another? Or an unsafe.Pointer? You can use a placeholder type, even. Make procAddr a *byte, for example.
The pointer conversion rules are intended to ensure safety when playing with Go pointers (by that, I mean pointers to objects in the Go heap or stack). They're definitely overkill for pointers that you know point into the C heap. Unfortunately, the vet rules don't know where the pointers came from. On Thursday, February 13, 2020 at 9:37:47 AM UTC-8 Alex wrote: > I have to use a massive third party API so it's not really a choice to use > cgo. > > Do you have any safer options to pass C pointers between packages? > The C pointers are all C allocated and package B needs to call C functions > directly and pass those pointers. > > On Friday, 14 February 2020 01:02:24 UTC+8, Jake Montgomery wrote: >> >> You need to read https://golang.org/pkg/unsafe/#Pointer *very, very, >> very* carefully before using unsafe.Pointer in any way. It spells out 6 >> conversions that are considered "valid". It says: "Code not using these >> patterns is likely to be invalid today or to become invalid in the future." >> AFAICT, your code does not fit any of those 6 allowable patterns. >> >> Go is simple and easy, CGO is tricky, difficult and full of dragons. >> >> >> On Thursday, February 13, 2020 at 11:42:30 AM UTC-5, Alex wrote: >>> >>> I have to pass C pointers between packages so I used uintptr like how >>> syscall does things. >>> However go vet gives the message "possible misuse of unsafe.Pointer". >>> >>> Is there something I could do to avoid vet complaining? >>> >>> Package A: >>> type Foo struct { >>> procAddr uintptr >>> } >>> >>> func (f Foo) ProcAddr() uintptr { >>> return f.procAddr >>> } >>> >>> func Bar() Foo { >>> return Foo{C.SomeFunc()} >>> } >>> >>> Package B: >>> p := C.ASDF(unsafe.Pointer(A.Bar().ProcAddr())) // possible misuse of >>> unsafe.Pointer >>> >>> -- 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 on the web visit https://groups.google.com/d/msgid/golang-nuts/497901a6-3aad-45a0-a261-890b1abe230c%40googlegroups.com.
