How can I cross-compile for Solaris with cgo? - c

Question

I am trying to compile some cgo code for Solaris. I get these errors when I try to build:
$ CGO_LDFLAGS="-L$(pwd)/solaris-11.4-amd64-libs" CGO_CFLAGS='-I/home/shane/src/ioctl-experimentation/solaris-11.4-headers -Wno-unknown-pragmas' CGO_ENABLED=1 GOOS=solaris GOARCH=amd64 go build
# runtime/cgo
/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/9/../../../x86_64-linux-gnu/Scrt1.o: in function `_start':
(.text+0x16): undefined reference to `__libc_csu_fini'
/usr/bin/ld: (.text+0x1d): undefined reference to `__libc_csu_init'
/usr/bin/ld: (.text+0x2a): undefined reference to `__libc_start_main'
/usr/bin/ld: $WORK/b003/_x003.o: in function `_cgo_release_context':
gcc_context.c:(.text+0x5c): undefined reference to `__stack_chk_fail'
/usr/bin/ld: $WORK/b003/_x004.o: in function `x_cgo_sys_thread_create':
gcc_libinit.c:(.text+0x87): undefined reference to `__stack_chk_fail'
/usr/bin/ld: $WORK/b003/_x004.o: in function `_cgo_wait_runtime_init_done':
gcc_libinit.c:(.text+0x121): undefined reference to `__stack_chk_fail'
/usr/bin/ld: $WORK/b003/_x004.o: in function `_cgo_try_pthread_create':
gcc_libinit.c:(.text+0x291): undefined reference to `__stack_chk_fail'
/usr/bin/ld: $WORK/b003/_x006.o: in function `x_cgo_init':
gcc_solaris_amd64.c:(.text+0xb6): undefined reference to `__stack_chk_fail'
/usr/bin/ld: $WORK/b003/_x006.o:gcc_solaris_amd64.c:(.text+0x214): more undefined references to `__stack_chk_fail' follow
collect2: error: ld returned 1 exit status
I am cross-compiling on Linux. Here is my Go version:
$ go version
go version go1.18.3 linux/amd64
The solaris-11.4-amd64-libs directory contains a copy of all files under /lib/amd64 from a Solaris 11.4 AMD64 machine. The solaris-11.4-headers directory contains a copy of all files under /usr/include from a Solaris 11.4 AMD64 machine.
Here is my Go code in main.go:
//go:build solaris
// +build solaris
package main
import "C"
func main() {
}
I know cgo is fully supported for Solaris as of Go 1.5, and I am using Go 1.18.
I'm looking for help understanding why these linker errors are happening, even when I copied across all libs from the /lib/amd64 directory. Is it possible there are more libs I also need to copy over from somewhere else?
Edit
At the suggestion of Liam Kelly, I looked at this question about how to link against a different libc. I tried passing -Xlinker -rpath=$(pwd)/solaris-11.4-amd64-libs as part of CGO_LDFLAGS, but I got the same errors as before. I tried using -nodefaultlibs and -nostdlib both separately and together along with -Xlinker -rpath=$(pwd)/solaris-11.4-amd64-libs, but using either of these two flags either separately or together just increased the number of linker errors.

Answer 1

I am going to assume that libxnet is needed for Solaris and that is why is is being automatically added.
First confirm that the libxnet library is where is should be with sudo find /lib libxnet*. I expect you will see one line of the output show:
lib/64/libxnet.so
Assuming you see the above output, I believe you just need to tell the linker to look in that location with CGO_LDFLAGS="-L/lib/64" CGO_ENABLED=1 GOOS=solaris GOARCH=amd64 go build. If that works then you should be able to embedded that LDFlag in your main.go file with:
// #cgo LDFLAGS: -L/lib/64
import "C"
Once embedded you will not need to explicitly set CGO_LDFLAGS