On Wed, Apr 29, 2020 at 8:58 PM Vincent Blanchon <blanchon.vinc...@gmail.com> wrote: > > Thank you again for your reply! > I thought Go would compile all the C files in one .go, that makes sense. > > By the way, how Go would deal with those files if cgo is not enabled - > meaning the internal linker will do the job? > How the internal linker can deal with that?
If you are using the internal linker, then you aren't using cgo, so the linker won't see all those C files. Ian > Le jeudi 30 avril 2020 07:52:03 UTC+4, Ian Lance Taylor a écrit : >> >> On Tue, Apr 28, 2020 at 10:49 PM Vincent Blanchon >> <blancho...@gmail.com> wrote: >> > >> > I'm building a simple program that has a dependency to >> > github.com/DataDog/zstd, a wrapper of a C code. >> > So by default, Go will use the external linker. When debugging with, I can >> > see >> > >> > host link: "clang" "-m64" "-Wl,-headerpad,1144" "-Wl,-no_pie" >> > "-Wl,-pagezero_size,4000000" "-o" >> > "/var/folders/bb/w1lgkjdx47qd7695hb5r400h0000gn/T/go-build122622791/b001/exe/a.out" >> > "-Qunused-arguments" >> > "/var/folders/bb/w1lgkjdx47qd7695hb5r400h0000gn/T/go-link-023224426/go.o" >> > "/var/folders/bb/w1lgkjdx47qd7695hb5r400h0000gn/T/go-link-023224426/000000.o" >> > [...] >> > "/var/folders/bb/w1lgkjdx47qd7695hb5r400h0000gn/T/go-link-023224426/000053.o" >> > >> > "/var/folders/bb/w1lgkjdx47qd7695hb5r400h0000gn/T/go-link-023224426/000054.o" >> > >> > "/var/folders/bb/w1lgkjdx47qd7695hb5r400h0000gn/T/go-link-023224426/000055.o" >> > "-g" "-O2" "-g" "-O2" "-g" "-O2" "-lpthread" "-g" "-O2" "-framework" >> > "CoreFoundation" "-framework" "Security" "-no-pie" >> > >> > It links 55 files, from 000000.o to 000055.oIf I had more custom debug, I >> > can see than those files are mostly duplication: >> > >> > 000004.o is >> > /path/to/go-build/67/678a3a394ba4feae32a2ddb829ea65c1cf24be64248dcbcc3dae709b8e3b826d-d >> > github.com/DataDog/zstd >> > /path/to/go-build/67/678a3a394ba4feae32a2ddb829ea65c1cf24be64248dcbcc3dae709b8e3b826d-d(_x005.o) >> > 000005.o is >> > /path/to/go-build/67/678a3a394ba4feae32a2ddb829ea65c1cf24be64248dcbcc3dae709b8e3b826d-d >> > github.com/DataDog/zstd >> > /path/to/go-build/67/678a3a394ba4feae32a2ddb829ea65c1cf24be64248dcbcc3dae709b8e3b826d-d(_x006.o) >> > >> > I can see 40 times this zstd package among the 55 files. Is it expected? >> > What is the difference between them? >> > >> > Also, what would happen to the non known cgo packages (not net, os/user or >> > runtime/cgo) if cgo is not enabled? How the internal linker will manage >> > this cgo package? >> >> I may be missing something, but that doesn't look like duplication to >> me. It looks like different files from an archive. The first one is >> _x005.o and the second one is _x006.o. >> >> You will get files like these for each .c file in a package that uses cgo. >> >> Ian > > -- > 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/38760d5d-b8e3-4a42-b087-8b81ab4ebd87%40googlegroups.com. -- 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/CAOyqgcUG8JOUNUovpJSnHzYaX9-x%3DRHqx4Dm5amW6AW61%3Dc7ZQ%40mail.gmail.com.
