Building and linking dynamically from a go binary

Question

My problem is the following:

1. I have a go binary on a machine
2. From that binary I need to compile an external .go file
3. Once compiled, I need to

Answer 1

This is very possible, you can even compile it as a native shared library

go build -buildmode=c-shared goc.go 

# file goc
goc: ELF 32-bit LSB  shared object, ARM, EABI5 version 1 (SYSV),
dynamically linked, 
BuildID[sha1]=f841e63ee8e916d7848ac8ee50d9980642b3ad86, 
not stripped

nm -D --defined-only ./goc | grep "T"

0004ebe8 T _cgoexp_f88ec80374ab_PrintInt
000a6178 T _cgo_panic
0004e954 T _cgo_sys_thread_start
000a48c8 T _cgo_topofstack
0004e88c T _cgo_wait_runtime_init_done
000a61a4 T crosscall2
0004ebc8 T crosscall_arm1
0004e7b0 T fatalf
00102648 T _fini
0004e544 T _init
0004e76c T PrintInt
0004ebe4 T __stack_chk_fail_local
0004eb5c T x_cgo_free
0004ea60 T x_cgo_init
0004eb24 T x_cgo_malloc
0004e8e0 T x_cgo_notify_runtime_init_done
0004eb14 T x_cgo_setenv
0004e820 T x_cgo_sys_thread_create
0004eb64 T x_cgo_thread_start
0004eb20 T x_cgo_unsetenv

like so (tested on go 1.5.1 linux/arm)

goc.go:

package main

import (
    "C"
    "fmt"
)

//export PrintInt
func PrintInt(x int) {
    fmt.Println(x)
}

// http://stackoverflow.com/questions/32215509/using-go-code-in-an-existing-c-project
// go build -buildmode=c-archive goc.go
// go build -buildmode=c-shared goc.go 

// https://groups.google.com/forum/#!topic/golang-nuts/1oELh6joLQg
// Trying it on windows/amd64, looks like it isn't supported yet.  Is this planned for the 1.5 release? 
// It will not be in the 1.5 release.
// It would be nice if somebody worked on it for 1.6.
// https://golang.org/s/execmodes

// http://stackoverflow.com/questions/19431296/building-and-linking-dynamically-from-a-go-binary
// go build -linkshared hello.g
// go install -buildmode=shared std



func main() {
    fmt.Println("Hello world")
}